abg-ir.cc

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// C++ -*-
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// -*- Mode: C++ -*-

// Copyright (C) 2013-2025 Red Hat, Inc.
//
//Author: Dodji Seketeli

/// @file
///
/// Definitions for the Internal Representation artifacts of libabigail.

#include <cxxabi.h>
#include <cstdint>
#include <functional>
#include <iterator>
#include <memory>
#include <sstream>
#include <typeinfo>
#include <unordered_map>
#include <utility>
#include <vector>

#include "abg-internal.h"
// <headers defining libabigail's API go under here>
ABG_BEGIN_EXPORT_DECLARATIONS

#include "abg-interned-str.h"
#include "abg-ir.h"
#include "abg-corpus.h"
#include "abg-regex.h"

ABG_END_EXPORT_DECLARATIONS
// </headers defining libabigail's API>

#include "abg-corpus-priv.h"
#include "abg-comp-filter.h"
#include "abg-ir-priv.h"

namespace
{
/// This internal type is a tree walking that is used to set the
/// qualified name of a tree of decls and types.  It used by the
/// function update_qualified_name().
class qualified_name_setter : public abigail::ir::ir_node_visitor
{

public:
  bool
  do_update(abigail::ir::decl_base* d);

  bool
  visit_begin(abigail::ir::decl_base* d);

  bool
  visit_begin(abigail::ir::type_base* d);
}; // end class qualified_name_setter

}// end anon namespace

namespace abigail
{

// Inject.
using std::string;
using std::list;
using std::vector;
using std::unordered_map;
using std::dynamic_pointer_cast;
using std::static_pointer_cast;

/// Convenience typedef for a map of string -> string*.
typedef unordered_map<string, string*> pool_map_type;

/// The type of the private data structure of type @ref
/// intered_string_pool.
struct interned_string_pool::priv
{
  pool_map_type map;
}; //end struc struct interned_string_pool::priv

/// Default constructor.
interned_string_pool::interned_string_pool()
  : priv_(new priv)
{
  priv_->map[""] = 0;
}

/// Test if the interned string pool already contains a string with a
/// given value.
///
/// @param s the string to test for.
///
/// @return true if the pool contains a string with the value @p s.
bool
interned_string_pool::has_string(const char* s) const
{return priv_->map.find(s) != priv_->map.end();}

/// Get a pointer to the interned string which has a given value.
///
/// @param s the value of the interned string to look for.
///
/// @return a pointer to the raw string of characters which has the
/// value of @p s.  Or null if no string with value @p s was interned.
const char*
interned_string_pool::get_string(const char* s) const
{
  unordered_map<string, string*>::const_iterator i =
    priv_->map.find(s);
  if (i == priv_->map.end())
    return 0;
  if (i->second)
    return i->second->c_str();
  return "";
}

/// Create an interned string with a given value.
///
/// @param str_value the value of the interned string to create.
///
/// @return the new created instance of @ref interned_string created.
interned_string
interned_string_pool::create_string(const std::string& str_value)
{
  string*& result = priv_->map[str_value];
  if (!result && !str_value.empty())
    result = new string(str_value);
  return interned_string(result);
}

/// Destructor.
interned_string_pool::~interned_string_pool()
{
  for (pool_map_type::iterator i = priv_->map.begin();
       i != priv_->map.end();
       ++i)
    if (i->second)
      delete i->second;
}

/// Equality operator.
///
/// @param l the instance of std::string on the left-hand-side of the
/// equality operator.
///
/// @param r the instance of @ref interned_string on the
/// right-hand-side of the equality operator.
///
/// @return true iff the two string are equal.
bool
operator==(const std::string& l, const interned_string& r)
{return r.operator==(l);}

bool
operator!=(const std::string& l, const interned_string& r)
{return !(l == r);}

/// Streaming operator.
///
/// Streams an instance of @ref interned_string to an output stream.
///
/// @param o the destination output stream.
///
/// @param s the instance of @ref interned_string to stream out.
///
/// @return the output stream this function just streamed to.
std::ostream&
operator<<(std::ostream& o, const interned_string& s)
{
  o << static_cast<std::string>(s);
  return o;
}

/// Concatenation operator.
///
/// Concatenate two instances of @ref interned_string, builds an
/// instance of std::string with the resulting string and return it.
///
/// @param s1 the first string to consider.
///
/// @param s2 the second string to consider.
///
/// @return the resuting concatenated string.
std::string
operator+(const interned_string& s1,const std::string& s2)
{return static_cast<std::string>(s1) + s2;}

/// Concatenation operator.
///
/// Concatenate two instances of @ref interned_string, builds an
/// instance of std::string with the resulting string and return it.
///
/// @param s1 the first string to consider.
///
/// @param s2 the second string to consider.
///
/// @return the resuting concatenated string.
std::string
operator+(const std::string& s1, const interned_string& s2)
{return s1 + static_cast<std::string>(s2);}

namespace ir
{

static size_t
hash_as_canonical_type_or_constant(const type_base *t);

static bool
has_generic_anonymous_internal_type_name(const decl_base *d);

static interned_string
get_generic_anonymous_internal_type_name(const decl_base *d);

static string
get_internal_real_type_name(const type_base*);

static void
update_qualified_name(decl_base * d);

static void
update_qualified_name(decl_base_sptr d);

static interned_string
pointer_declaration_name(const type_base* ptr,
             const string& variable_name,
             bool qualified, bool internal);

static interned_string
pointer_declaration_name(const type_base_sptr& ptr,
             const string& variable_name,
             bool qualified, bool internal);

static interned_string
ptr_to_mbr_declaration_name(const ptr_to_mbr_type* ptr,
                const string& variable_name,
                bool qualified, bool internal);

static interned_string
ptr_to_mbr_declaration_name(const ptr_to_mbr_type_sptr& ptr,
                const string& variable_name,
                bool qualified, bool internal);

static interned_string
array_declaration_name(const array_type_def* array,
               const string& variable_name,
               bool qualified, bool internal);

static interned_string
array_declaration_name(const array_type_def_sptr& array,
               const string& variable_name,
               bool qualified, bool internal);

static void
stream_pretty_representation_of_fn_parms(const function_type& fn_type,
                     ostream& o, bool qualified,
                     bool internal);
static string
add_outer_pointer_to_fn_type_expr(const type_base* pointer_to_fn,
                  const string& input, bool qualified,
                  bool internal);

static string
add_outer_pointer_to_fn_type_expr(const type_base_sptr& pointer_to_fn,
                  const string& input, bool qualified,
                  bool internal);

static string
add_outer_pointer_to_array_type_expr(const type_base* pointer_to_ar,
                     const string& input, bool qualified,
                     bool internal);

static string
add_outer_pointer_to_array_type_expr(const type_base_sptr& pointer_to_ar,
                     const string& input, bool qualified,
                     bool internal);

static string
add_outer_ptr_to_mbr_type_expr(const ptr_to_mbr_type* p,
                   const  string& input, bool qualified,
                   bool internal);

static string
add_outer_ptr_to_mbr_type_expr(const ptr_to_mbr_type_sptr& p,
                   const  string& input, bool qualified,
                   bool internal);

static string
add_outer_pointer_to_ptr_to_mbr_type_expr(const type_base* p,
                      const  string& input,
                      bool qualified, bool internal);

void
push_composite_type_comparison_operands(const type_base& left,
                    const type_base& right);

void
pop_composite_type_comparison_operands(const type_base& left,
                       const type_base& right);


/// Push a pair of operands on the stack of operands of the current
/// type comparison, during type canonicalization.
///
/// For more information on this, please look at the description of
/// the environment::priv::right_type_comp_operands_ data member.
///
/// @param left the left-hand-side comparison operand to push.
///
/// @param right the right-hand-side comparison operand to push.
void
push_composite_type_comparison_operands(const type_base& left,
                    const type_base& right)
{
  const environment& env = left.get_environment();
  env.priv_->push_composite_type_comparison_operands(&left, &right);
}

/// Pop a pair of operands from the stack of operands to the current
/// type comparison.
///
/// For more information on this, please look at the description of
/// the environment::privright_type_comp_operands_ data member.
///
/// @param left the left-hand-side comparison operand we expect to
/// pop from the top of the stack.  If this doesn't match the
/// operand found on the top of the stack, the function aborts.
///
/// @param right the right-hand-side comparison operand we expect to
/// pop from the bottom of the stack. If this doesn't match the
/// operand found on the top of the stack, the function aborts.
void
pop_composite_type_comparison_operands(const type_base& left,
                       const type_base& right)
{
  const environment& env = left.get_environment();
  env.priv_->pop_composite_type_comparison_operands(&left, &right);
}

/// Getter of the canonical type index of a given type.
///
/// @param t the type to consider.
///
/// @return the CTI of the type.
size_t
get_canonical_type_index(const type_base& t)
{return t.priv_->canonical_type_index;}

/// Getter of the canonical type index of a given type.
///
/// @param t the type to consider.
///
/// @return the CTI of the type.
size_t
get_canonical_type_index(const type_base* t)
{return get_canonical_type_index(*t);}

/// Getter of the canonical type index of a given type.
///
/// @param t the type to consider.
///
/// @return the CTI of the type.
size_t
get_canonical_type_index(const type_base_sptr& t)
{return get_canonical_type_index(t.get());}

/// Test if a type originates from a corpus.
///
/// Note that this function supports testing if a type originates from
/// a corpus group.
///
/// @param t the type to consider.
///
/// @param c the corpus or corpus group to consider.
///
/// @return true iff the type @p t originates from the corpus (or
/// group) @p c.
bool
type_originates_from_corpus(type_base_sptr t, corpus_sptr& c)
{
  bool result = false;
  if (c && t->get_corpus())
    {
      corpus_group_sptr g = is_corpus_group(c);
      if (g)
    {
      if (t->get_corpus()->get_group() == g.get())
        result = true;
    }
      else
    {
      if (t->get_corpus() == c.get())
        result = true;
    }
    }
  return result;
}
/// @brief the location of a token represented in its simplest form.
/// Instances of this type are to be stored in a sorted vector, so the
/// type must have proper relational operators.
class expanded_location
{
  string    path_;
  unsigned  line_;
  unsigned  column_;

  expanded_location();

public:

  friend class location_manager;

  expanded_location(const string& path, unsigned line, unsigned column)
  : path_(path), line_(line), column_(column)
  {}

  bool
  operator==(const expanded_location& l) const
  {
    return (path_ == l.path_
        && line_ == l.line_
        && column_ && l.column_);
  }

  bool
  operator<(const expanded_location& l) const
  {
    if (path_ < l.path_)
      return true;
    else if (path_ > l.path_)
      return false;

    if (line_ < l.line_)
      return true;
    else if (line_ > l.line_)
      return false;

    return column_ < l.column_;
  }
};

/// Expand the location into a tripplet path, line and column number.
///
/// @param path the output parameter where this function sets the
/// expanded path.
///
/// @param line the output parameter where this function sets the
/// expanded line.
///
/// @param column the ouptut parameter where this function sets the
/// expanded column.
void
location::expand(std::string& path, unsigned& line, unsigned& column) const
{
  if (!get_location_manager())
    {
      // We don't have a location manager maybe because this location
      // was just freshly instanciated.  We still want to be able to
      // expand to default values.
      path = "";
      line = 0;
      column = 0;
      return;
    }
  get_location_manager()->expand_location(*this, path, line, column);
}


/// Expand the location into a string.
///
/// @return the string representing the location.
string
location::expand(void) const
{
  string path, result;
  unsigned line = 0, column = 0;
  expand(path, line, column);

  std::ostringstream o;
  o << path << ":" << line << ":" << column;
  return o.str();
}

struct location_manager::priv
{
  /// This sorted vector contains the expanded locations of the tokens
  /// coming from a given ABI Corpus.  The index of a given expanded
  /// location in the table gives us an integer that is used to build
  /// instance of location types.
  std::vector<expanded_location> locs;
};

location_manager::location_manager()
  : priv_(new location_manager::priv)
{}

location_manager::~location_manager() = default;

/// Insert the triplet representing a source locus into our internal
/// vector of location triplet.  Return an instance of location type,
/// built from an real type that represents the index of the
/// source locus triplet into our source locus table.
///
/// @param file_path the file path of the source locus
/// @param line the line number of the source location
/// @param col the column number of the source location
location
location_manager::create_new_location(const std::string&    file_path,
                      size_t            line,
                      size_t            col)
{
  expanded_location l(file_path, line, col);

  // Just append the new expanded location to the end of the vector
  // and return its index.  Note that indexes start at 1.
  priv_->locs.push_back(l);
  return location(priv_->locs.size(), this);
}

/// Given an instance of location type, return the triplet
/// {path,line,column} that represents the source locus.  Note that
/// the location must have been previously created from the function
/// location_manager::create_new_location, otherwise this function yields
/// unexpected results, including possibly a crash.
///
/// @param location the instance of location type to expand
/// @param path the resulting path of the source locus
/// @param line the resulting line of the source locus
/// @param column the resulting colum of the source locus
void
location_manager::expand_location(const location&   location,
                  std::string&      path,
                  unsigned&     line,
                  unsigned&     column) const
{
  if (location.value_ == 0)
    return;
  expanded_location &l = priv_->locs[location.value_ - 1];
  path = l.path_;
  line = l.line_;
  column = l.column_;
}

typedef unordered_map<function_type_sptr,
              bool,
              function_type::hash,
              type_shared_ptr_equal> fn_type_ptr_map;

// <type_maps stuff>

struct type_maps::priv
{
  mutable istring_type_base_wptrs_map_type  basic_types_;
  mutable istring_type_base_wptrs_map_type  class_types_;
  mutable istring_type_base_wptrs_map_type  union_types_;
  mutable istring_type_base_wptrs_map_type  enum_types_;
  mutable istring_type_base_wptrs_map_type  typedef_types_;
  mutable istring_type_base_wptrs_map_type  qualified_types_;
  mutable istring_type_base_wptrs_map_type  pointer_types_;
  mutable istring_type_base_wptrs_map_type  ptr_to_mbr_types_;
  mutable istring_type_base_wptrs_map_type  reference_types_;
  mutable istring_type_base_wptrs_map_type  array_types_;
  mutable istring_type_base_wptrs_map_type  subrange_types_;
  mutable istring_type_base_wptrs_map_type  function_types_;
  mutable vector<type_base_wptr>        sorted_types_;
}; // end struct type_maps::priv

type_maps::type_maps()
  : priv_(new priv)
{}

type_maps::~type_maps() = default;

/// Test if the type_maps is empty.
///
/// @return true iff the type_maps is empty.
bool
type_maps::empty() const
{
  return (basic_types().empty()
      && class_types().empty()
      && union_types().empty()
      && enum_types().empty()
      && typedef_types().empty()
      && qualified_types().empty()
      && pointer_types().empty()
      && reference_types().empty()
      && array_types().empty()
      && subrange_types().empty()
      && function_types().empty());
}

/// Getter for the map that associates the name of a basic type to the
/// vector instances of type_decl_sptr that represents that type.
const istring_type_base_wptrs_map_type&
type_maps::basic_types() const
{return priv_->basic_types_;}

/// Getter for the map that associates the name of a basic type to the
/// vector of instances of @ref type_decl_sptr that represents that
/// type.
istring_type_base_wptrs_map_type&
type_maps::basic_types()
{return priv_->basic_types_;}

/// Getter for the map that associates the name of a class type to the
/// vector of instances of @ref class_decl_sptr that represents that
/// type.
const istring_type_base_wptrs_map_type&
type_maps::class_types() const
{return priv_->class_types_;}

/// Getter for the map that associates the name of a class type to the
/// vector of instances of @ref class_decl_sptr that represents that
/// type.
istring_type_base_wptrs_map_type&
type_maps::class_types()
{return priv_->class_types_;}

/// Getter for the map that associates the name of a union type to the
/// vector of instances of @ref union_decl_sptr that represents that
/// type.
istring_type_base_wptrs_map_type&
type_maps::union_types()
{return priv_->union_types_;}

/// Getter for the map that associates the name of a union type to the
/// vector of instances of @ref union_decl_sptr that represents that
/// type.
const istring_type_base_wptrs_map_type&
type_maps::union_types() const
{return priv_->union_types_;}

/// Getter for the map that associates the name of an enum type to the
/// vector of instances of @ref enum_type_decl_sptr that represents
/// that type.
istring_type_base_wptrs_map_type&
type_maps::enum_types()
{return priv_->enum_types_;}

/// Getter for the map that associates the name of an enum type to the
/// vector of instances of @ref enum_type_decl_sptr that represents
/// that type.
const istring_type_base_wptrs_map_type&
type_maps::enum_types() const
{return priv_->enum_types_;}

/// Getter for the map that associates the name of a typedef to the
/// vector of instances of @ref typedef_decl_sptr that represents tha
/// type.
istring_type_base_wptrs_map_type&
type_maps::typedef_types()
{return priv_->typedef_types_;}

/// Getter for the map that associates the name of a typedef to the
/// vector of instances of @ref typedef_decl_sptr that represents tha
/// type.
const istring_type_base_wptrs_map_type&
type_maps::typedef_types() const
{return priv_->typedef_types_;}

/// Getter for the map that associates the name of a qualified type to
/// the vector of instances of @ref qualified_type_def_sptr.
istring_type_base_wptrs_map_type&
type_maps::qualified_types()
{return priv_->qualified_types_;}

/// Getter for the map that associates the name of a qualified type to
/// the vector of instances of @ref qualified_type_def_sptr.
const istring_type_base_wptrs_map_type&
type_maps::qualified_types() const
{return priv_->qualified_types_;}

/// Getter for the map that associates the name of a pointer type to
/// the vector of instances of @ref pointer_type_def_sptr that
/// represents that type.
istring_type_base_wptrs_map_type&
type_maps::pointer_types()
{return priv_->pointer_types_;}

/// Getter for the map that associates the name of a pointer-to-member
/// type to the vector of instances of @ref ptr_to_mbr_type_sptr that
/// represents that type.
istring_type_base_wptrs_map_type&
type_maps::ptr_to_mbr_types()
{return priv_->ptr_to_mbr_types_;}

/// Getter for the map that associates the name of a pointer-to-member
/// type to the vector of instances of @ref ptr_to_mbr_type_sptr that
/// represents that type.
const istring_type_base_wptrs_map_type&
type_maps::ptr_to_mbr_types() const
{return priv_->ptr_to_mbr_types_;}

/// Getter for the map that associates the name of a pointer type to
/// the vector of instances of @ref pointer_type_def_sptr that
/// represents that type.
const istring_type_base_wptrs_map_type&
type_maps::pointer_types() const
{return priv_->pointer_types_;}

/// Getter for the map that associates the name of a reference type to
/// the vector of instances of @ref reference_type_def_sptr that
/// represents that type.
istring_type_base_wptrs_map_type&
type_maps::reference_types()
{return priv_->reference_types_;}

/// Getter for the map that associates the name of a reference type to
/// the vector of instances of @ref reference_type_def_sptr that
/// represents that type.
const istring_type_base_wptrs_map_type&
type_maps::reference_types() const
{return priv_->reference_types_;}

/// Getter for the map that associates the name of an array type to
/// the vector of instances of @ref array_type_def_sptr that
/// represents that type.
istring_type_base_wptrs_map_type&
type_maps::array_types()
{return priv_->array_types_;}

/// Getter for the map that associates the name of an array type to
/// the vector of instances of @ref array_type_def_sptr that
/// represents that type.
const istring_type_base_wptrs_map_type&
type_maps::array_types() const
{return priv_->array_types_;}

/// Getter for the map that associates the name of a subrange type to
/// the vector of instances of @ref array_type_def::subrange_sptr that
/// represents that type.
istring_type_base_wptrs_map_type&
type_maps::subrange_types()
{return priv_->subrange_types_;}

/// Getter for the map that associates the name of a subrange type to
/// the vector of instances of @ref array_type_def::subrange_sptr that
/// represents that type.
const istring_type_base_wptrs_map_type&
type_maps::subrange_types() const
{return priv_->subrange_types_;}

/// Getter for the map that associates the name of a function type to
/// the vector of instances of @ref function_type_sptr that represents
/// that type.
const istring_type_base_wptrs_map_type&
type_maps::function_types() const
{return priv_->function_types_;}

/// Getter for the map that associates the name of a function type to
/// the vector of instances of @ref function_type_sptr that represents
/// that type.
istring_type_base_wptrs_map_type&
type_maps::function_types()
{return priv_->function_types_;}

/// A comparison functor to compare/sort types based on their pretty
/// representations.
struct type_name_comp
{
  /// Comparison operator for two instances of @ref type_base.
  ///
  /// This compares the two types by lexicographically comparing their
  /// pretty representation.
  ///
  /// @param l the left-most type to compare.
  ///
  /// @param r the right-most type to compare.
  ///
  /// @return true iff @p l < @p r.
  bool
  operator()(type_base *l, type_base *r) const
  {
    if (l == 0 && r == 0)
      return false;

    string l_repr = get_pretty_representation(l);
    string r_repr = get_pretty_representation(r);
    return l_repr < r_repr;
  }

  /// Comparison operator for two instances of @ref type_base.
  ///
  /// This compares the two types by lexicographically comparing their
  /// pretty representation.
  ///
  /// @param l the left-most type to compare.
  ///
  /// @param r the right-most type to compare.
  ///
  /// @return true iff @p l < @p r.
  bool
  operator()(const type_base_sptr &l, const type_base_sptr &r) const
  {return operator()(l.get(), r.get());}

  /// Comparison operator for two instances of @ref type_base.
  ///
  /// This compares the two types by lexicographically comparing their
  /// pretty representation.
  ///
  /// @param l the left-most type to compare.
  ///
  /// @param r the right-most type to compare.
  ///
  /// @return true iff @p l < @p r.
  bool
  operator()(const type_base_wptr &l, const type_base_wptr &r) const
  {return operator()(type_base_sptr(l), type_base_sptr(r));}
}; // end struct type_name_comp

#ifdef WITH_DEBUG_SELF_COMPARISON

/// This is a function called when the ABG_RETURN* macros defined
/// below return false.
///
/// The purpose of this function is to ease debugging.  To know where
/// the equality functions first compare non-equal, we can just set a
/// breakpoint on this notify_equality_failed function and run the
/// equality functions.  Because all the equality functions use the
/// ABG_RETURN* macros to return their values, this function is always
/// called when any of those equality function return false.
///
/// @param l the first operand of the equality.
///
/// @param r the second operand of the equality.
static void
notify_equality_failed(const type_or_decl_base &l __attribute__((unused)),
               const type_or_decl_base &r __attribute__((unused)))
{}

/// This is a function called when the ABG_RETURN* macros defined
/// below return false.
///
/// The purpose of this function is to ease debugging.  To know where
/// the equality functions first compare non-equal, we can just set a
/// breakpoint on this notify_equality_failed function and run the
/// equality functions.  Because all the equality functions use the
/// ABG_RETURN* macros to return their values, this function is always
/// called when any of those equality function return false.
///
/// @param l the first operand of the equality.
///
/// @param r the second operand of the equality.
static void
notify_equality_failed(const type_or_decl_base *l __attribute__((unused)),
               const type_or_decl_base *r __attribute__((unused)))
{}

#define ABG_RETURN_EQUAL(l, r)          \
  do                        \
    {                       \
      if (l != r)               \
        notify_equality_failed(l, r);       \
      return (l == r);              \
    }                       \
  while(false)


#define ABG_RETURN_FALSE        \
  do                    \
    {                   \
      notify_equality_failed(l, r); \
      return false;         \
    } while(false)

#define ABG_RETURN(value)           \
  do                        \
    {                       \
      if (value == false)           \
    notify_equality_failed(l, r);       \
      return value;             \
    } while (false)

#else // WITH_DEBUG_SELF_COMPARISON

#define ABG_RETURN_FALSE return false
#define ABG_RETURN(value) return (value)
#define ABG_RETURN_EQUAL(l, r) return ((l) == (r));
#endif

/// Get the canonical type of a given type T* as a T*.
///
/// Note that normally, canonical types are returned as @ref
/// type_base* (un-typed form, kind of).  This function returns the
/// canonical type as a T*, just like the T* it is looking at.
///
///
/// @param t the type to consider.
///
/// @return either the canonical type of @p t or @p t itself if it
/// doesn't have any canonical type.
template<typename T>
T*
maybe_get_canonical_type(T* t)
{
  if (!t)
    return nullptr;
  if (type_base* type = t->get_naked_canonical_type())
    return dynamic_cast<T*>(type);
  return t;
}

/// Compare two types by comparing their canonical types if present.
///
/// If the canonical types are not present (because the types have not
/// yet been canonicalized, for instance) then the types are compared
/// structurally.
///
/// @param l the first type to take into account in the comparison.
///
/// @param r the second type to take into account in the comparison.
template<typename T>
bool
try_canonical_compare(const T *l, const T *r)
{
#if WITH_DEBUG_TYPE_CANONICALIZATION
  // We are debugging the canonicalization of a type down the stack.
  // 'l' is a subtype of a canonical type and 'r' is a subtype of the
  // type being canonicalized.  We are at a point where we can compare
  // 'l' and 'r' either using canonical comparison (if 'l' and 'r'
  // have canonical types) or structural comparison.
  //
  // Because we are debugging the process of type canonicalization, we
  // want to compare 'l' and 'r' canonically *AND* structurally.  Both
  // kinds of comparison should yield the same result, otherwise type
  // canonicalization just failed for the subtype 'r' of the type
  // being canonicalized.
  //
  // In concrete terms, this function is going to be called twice with
  // the same pair {'l', 'r'} to compare: The first time with
  // environment::priv_->use_canonical_type_comparison_ set to true,
  // instructing us to compare them canonically, and the second time
  // with that boolean set to false, instructing us to compare them
  // structurally.
  const environment&env = l->get_environment();
  if (env.priv_->use_canonical_type_comparison_)
    {
      if (const type_base *lc = l->get_naked_canonical_type())
    if (const type_base *rc = r->get_naked_canonical_type())
      ABG_RETURN_EQUAL(lc, rc);
    }

  // If the two types have a non-empty hash value, then consider those
  // hash values.  If the hashes are different then the two types are
  // different.  If the hashes are equal then we'll compare then
  // structurally.
  if (hash_t l_hash = peek_hash_value(*l))
    if (hash_t r_hash = peek_hash_value(*r))
      if (l_hash != r_hash)
    ABG_RETURN_FALSE;

  // If a type has a canonical type, use its canonical type, always.
  l = maybe_get_canonical_type(l);
  r = maybe_get_canonical_type(r);

  return equals(*l, *r, 0);
#else
  if (const type_base *lc = l->get_naked_canonical_type())
    if (const type_base *rc = r->get_naked_canonical_type())
      ABG_RETURN_EQUAL(lc, rc);

  // If the two types have a non-empty hash value, then consider those
  // hash values.  If the hashes are different then the two types are
  // different.  If the hashes are equal then we'll compare then
  // structurally.
  if (hash_t l_hash = peek_hash_value(*l))
    if (hash_t r_hash = peek_hash_value(*r))
      if (l_hash != r_hash)
    ABG_RETURN_FALSE;

  // If a type has a canonical type, use its canonical type, always.
  l = maybe_get_canonical_type(l);
  r = maybe_get_canonical_type(r);

  return equals(*l, *r, 0);
#endif
}

/// Detect if a recursive comparison cycle is detected while
/// structurally comparing two types (a.k.a member-wise comparison).
///
/// @param l the left-hand-side operand of the current comparison.
///
/// @param r the right-hand-side operand of the current comparison.
///
/// @return true iff a comparison cycle is detected.
template<typename T>
bool
is_comparison_cycle_detected(T& l, T& r)
{
  bool result = l.priv_->comparison_started(l, r);
  return result ;
}

/// Detect if a recursive comparison cycle is detected while
/// structurally comparing two @ref class_decl types.
///
/// @param l the left-hand-side operand of the current comparison.
///
/// @param r the right-hand-side operand of the current comparison.
///
/// @return true iff a comparison cycle is detected.
template<>
bool
is_comparison_cycle_detected(const class_decl& l, const class_decl& r)
{
  return is_comparison_cycle_detected(static_cast<const class_or_union&>(l),
                      static_cast<const class_or_union&>(r));
}

/// This macro is to be used while comparing composite types that
/// might recursively refer to themselves.  Comparing two such types
/// might get us into a cyle.
///
/// Practically, if we detect that we are already into comparing 'l'
/// and 'r'; then, this is a cycle.
//
/// To break the cycle, we assume the result of the comparison is true
/// for now.  Comparing the other sub-types of l & r will tell us later
/// if l & r are actually different or not.
///
/// In the mean time, returning true from this macro should not be
/// used to propagate the canonical type of 'l' onto 'r' as we don't
/// know yet if l equals r.  All the types that depend on l and r
/// can't (and that are in the comparison stack currently) can't have
/// their canonical type propagated either.  So this macro disallows
/// canonical type propagation for those types that depend on a
/// recursively defined sub-type for now.
///
/// @param l the left-hand-side operand of the comparison.
#define RETURN_TRUE_IF_COMPARISON_CYCLE_DETECTED(l, r)          \
  do                                    \
    {                                   \
      if (is_comparison_cycle_detected(l, r))               \
    return true;                            \
    }                                   \
  while(false)


/// Mark a pair of types as being compared.
///
/// This is helpful to later detect recursive cycles in the comparison
/// stack.
///
/// @param l the left-hand-side operand of the comparison.
///
/// @parm r the right-hand-side operand of the comparison.
template<typename T>
void
mark_types_as_being_compared(T& l, T&r)
{
  l.priv_->mark_as_being_compared(l, r);
  push_composite_type_comparison_operands(l, r);
}

/// Mark a pair of @ref class_decl types as being compared.
///
/// This is helpful to later detect recursive cycles in the comparison
/// stack.
///
/// @param l the left-hand-side operand of the comparison.
///
/// @parm r the right-hand-side operand of the comparison.
template<>
void
mark_types_as_being_compared(const class_decl& l, const class_decl &r)
{
  return mark_types_as_being_compared(static_cast<const class_or_union&>(l),
                      static_cast<const class_or_union&>(r));
}

/// Mark a pair of types as being not compared anymore.
///
/// This is helpful to later detect recursive cycles in the comparison
/// stack.
///
/// Note that the types must have been passed to
/// mark_types_as_being_compared prior to calling this function.
///
/// @param l the left-hand-side operand of the comparison.
///
/// @parm r the right-hand-side operand of the comparison.
template<typename T>
void
unmark_types_as_being_compared(T& l, T&r)
{
  l.priv_->unmark_as_being_compared(l, r);
  pop_composite_type_comparison_operands(l, r);
}

/// Mark a pair of @ref class_decl types as being not compared
/// anymore.
///
/// This is helpful to later detect recursive cycles in the comparison
/// stack.
///
/// Note that the types must have been passed to
/// mark_types_as_being_compared prior to calling this function.
///
/// @param l the left-hand-side operand of the comparison.
///
/// @parm r the right-hand-side operand of the comparison.
template<>
void
unmark_types_as_being_compared(const class_decl& l, const class_decl &r)
{
  return unmark_types_as_being_compared(static_cast<const class_or_union&>(l),
                    static_cast<const class_or_union&>(r));
}

/// Return the result of the comparison of two (sub) types.
///
/// The function does the necessary book keeping before returning the
/// result of the comparison of two (sub) types.
///
/// The book-keeping done is essentially about type comparison cycle detection.
///
///   @param l the left-hand-side operand of the type comparison
///
///   @param r the right-hand-side operand of the type comparison
///
///   @param value the result of the comparison of @p l and @p r.
///
///   @return the value @p value.
template<typename T>
bool
return_comparison_result(T& l, T& r, bool value)
{
  unmark_types_as_being_compared(l, r);
  ABG_RETURN(value);
}

#define CACHE_AND_RETURN_COMPARISON_RESULT(value)           \
  do                                    \
    {                                   \
      bool res = return_comparison_result(l, r, value);     \
      l.get_environment().priv_->cache_type_comparison_result(l, r, res); \
      return res;                           \
    } while (false)

/// Cache the result of a comparison between too artifacts (l & r) and
/// return immediately.
///
/// @param value the value to cache.
#define CACHE_COMPARISON_RESULT_AND_RETURN(value)           \
  do                                    \
    {                                   \
      l.get_environment().priv_->cache_type_comparison_result(l, r, value); \
      return value;                         \
    } while (false)

/// Getter of all types types sorted by their pretty representation.
///
/// @return a sorted vector of all types sorted by their pretty
/// representation.
const vector<type_base_wptr>&
type_maps::get_types_sorted_by_name() const
{
  if (priv_->sorted_types_.empty())
    {
      istring_type_base_wptrs_map_type::const_iterator i;
      vector<type_base_wptr>::const_iterator j;

      for (i = basic_types().begin(); i != basic_types().end(); ++i)
    for (j = i->second.begin(); j != i->second.end(); ++j)
      priv_->sorted_types_.push_back(*j);

      for (i = class_types().begin(); i != class_types().end(); ++i)
    for (j = i->second.begin(); j != i->second.end(); ++j)
      priv_->sorted_types_.push_back(*j);

      for (i = union_types().begin(); i != union_types().end(); ++i)
    for (j = i->second.begin(); j != i->second.end(); ++j)
      priv_->sorted_types_.push_back(*j);

      for (i = enum_types().begin(); i != enum_types().end(); ++i)
    for (j = i->second.begin(); j != i->second.end(); ++j)
      priv_->sorted_types_.push_back(*j);

      for (i = typedef_types().begin(); i != typedef_types().end(); ++i)
    for (j = i->second.begin(); j != i->second.end(); ++j)
      priv_->sorted_types_.push_back(*j);

      type_name_comp comp;
      sort(priv_->sorted_types_.begin(), priv_->sorted_types_.end(), comp);
    }

  return priv_->sorted_types_;
}

// </type_maps stuff>

// <translation_unit stuff>

/// Constructor of translation_unit.
///
/// @param env the environment of this translation unit.  Please note
/// that the life time of the environment must be greater than the
/// life time of the translation unit because the translation uses
/// resources that are allocated in the environment.
///
/// @param path the location of the translation unit.
///
/// @param address_size the size of addresses in the translation unit,
/// in bits.
translation_unit::translation_unit(const environment&   env,
                   const std::string&   path,
                   char     address_size)
  : priv_(new priv(env))
{
  priv_->path_ = path;
  priv_->address_size_ = address_size;
}

/// Getter of the the global scope of the translation unit.
///
/// @return the global scope of the current translation unit.  If
/// there is not global scope allocated yet, this function creates one
/// and returns it.
const scope_decl_sptr&
translation_unit::get_global_scope() const
{
  return const_cast<translation_unit*>(this)->get_global_scope();
}

/// Getter of the global scope of the translation unit.
///
/// @return the global scope of the current translation unit.  If
/// there is not allocated yet, this function creates one and returns
/// it.
scope_decl_sptr&
translation_unit::get_global_scope()
{
  if (!priv_->global_scope_)
    {
      priv_->global_scope_.reset
    (new global_scope(const_cast<translation_unit*>(this)));
      priv_->global_scope_->set_translation_unit
    (const_cast<translation_unit*>(this));
    }
  return priv_->global_scope_;
}

/// Getter of the types of the current @ref translation_unit.
///
/// @return the maps of the types of the translation unit.
const type_maps&
translation_unit::get_types() const
{return priv_->types_;}

/// Getter of the types of the current @ref translation_unit.
///
/// @return the maps of the types of the translation unit.
type_maps&
translation_unit::get_types()
{return priv_->types_;}

/// Get the vector of function types that are used in the current
/// translation unit.
///
/// @return the vector of function types that are used in the current
/// translation unit.
const vector<function_type_sptr>&
translation_unit::get_live_fn_types() const
{return priv_->live_fn_types_;}

/// Getter of the environment of the current @ref translation_unit.
///
/// @return the translation unit of the current translation unit.
const environment&
translation_unit::get_environment() const
{return priv_->env_;}

/// Getter of the language of the source code of the translation unit.
///
/// @return the language of the source code.
translation_unit::language
translation_unit::get_language() const
{return priv_->language_;}

/// Setter of the language of the source code of the translation unit.
///
/// @param l the new language.
void
translation_unit::set_language(language l)
{priv_->language_ = l;}


/// Get the path of the current translation unit.
///
/// This path is relative to the build directory of the translation
/// unit as returned by translation_unit::get_compilation_dir_path.
///
/// @return the relative path of the compilation unit associated to
/// the current instance of translation_unit.
//
const std::string&
translation_unit::get_path() const
{return priv_->path_;}

/// Set the path associated to the current instance of
/// translation_unit.
///
/// This path is relative to the build directory of the translation
/// unit as returned by translation_unit::get_compilation_dir_path.
///
/// @param a_path the new relative path to set.
void
translation_unit::set_path(const string& a_path)
{priv_->path_ = a_path;}


/// Get the path of the directory that was 'current' when the
/// translation unit was compiled.
///
/// Note that the path returned by translation_unit::get_path is
/// relative to the path returned by this function.
///
/// @return the compilation directory for the current translation
/// unit.
const std::string&
translation_unit::get_compilation_dir_path() const
{return priv_->comp_dir_path_;}

/// Set the path of the directory that was 'current' when the
/// translation unit was compiled.
///
/// Note that the path returned by translation_unit::get_path is
/// relative to the path returned by this function.
///
/// @param the compilation directory for the current translation unit.
void
translation_unit::set_compilation_dir_path(const std::string& d)
{priv_->comp_dir_path_ = d;}

/// Get the concatenation of the build directory and the relative path
/// of the translation unit.
///
/// @return the absolute path of the translation unit.
const std::string&
translation_unit::get_absolute_path() const
{
  if (priv_->abs_path_.empty())
    {
      string path;
      if (!priv_->path_.empty())
    {
      if (!priv_->comp_dir_path_.empty())
        {
          path = priv_->comp_dir_path_;
          path += "/";
        }
      path += priv_->path_;
    }
      priv_->abs_path_ = path;
    }

  return priv_->abs_path_;
}

/// Set the corpus this translation unit is a member of.
///
/// Note that adding a translation unit to a @ref corpus automatically
/// triggers a call to this member function.
///
/// @param corpus the corpus.
void
translation_unit::set_corpus(corpus* c)
{priv_->corp = c;}

/// Get the corpus this translation unit is a member of.
///
/// @return the parent corpus, or nil if this doesn't belong to any
/// corpus yet.
corpus*
translation_unit::get_corpus()
{return priv_->corp;}

/// Get the corpus this translation unit is a member of.
///
/// @return the parent corpus, or nil if this doesn't belong to any
/// corpus yet.
const corpus*
translation_unit::get_corpus() const
{return const_cast<translation_unit*>(this)->get_corpus();}

/// Getter of the location manager for the current translation unit.
///
/// @return a reference to the location manager for the current
/// translation unit.
location_manager&
translation_unit::get_loc_mgr()
{return priv_->loc_mgr_;}

/// const Getter of the location manager.
///
/// @return a const reference to the location manager for the current
/// translation unit.
const location_manager&
translation_unit::get_loc_mgr() const
{return priv_->loc_mgr_;}

/// Tests whether if the current translation unit contains ABI
/// artifacts or not.
///
/// @return true iff the current translation unit is empty.
bool
translation_unit::is_empty() const
{
  if (!priv_->global_scope_)
    return true;
  return get_global_scope()->is_empty();
}

/// Getter of the address size in this translation unit.
///
/// @return the address size, in bits.
char
translation_unit::get_address_size() const
{return priv_->address_size_;}

/// Setter of the address size in this translation unit.
///
/// @param a the new address size in bits.
void
translation_unit::set_address_size(char a)
{priv_->address_size_= a;}

/// Getter of the 'is_constructed" flag.  It says if the translation
/// unit is fully constructed or not.
///
/// This flag is important for cases when comparison might depend on
/// if the translation unit is fully built or not.  For instance, when
/// reading types from DWARF, the virtual methods of a class are not
/// necessarily fully constructed until we have reached the end of the
/// translation unit.  In that case, before we've reached the end of
/// the translation unit, we might not take virtual functions into
/// account when comparing classes.
///
/// @return true if the translation unit is constructed.
bool
translation_unit::is_constructed() const
{return priv_->is_constructed_;}

/// Setter of the 'is_constructed" flag.  It says if the translation
/// unit is fully constructed or not.
///
/// This flag is important for cases when comparison might depend on
/// if the translation unit is fully built or not.  For instance, when
/// reading types from DWARF, the virtual methods of a class are not
/// necessarily fully constructed until we have reached the end of the
/// translation unit.  In that case, before we've reached the end of
/// the translation unit, we might not take virtual functions into
/// account when comparing classes.
///
/// @param f true if the translation unit is constructed.
void
translation_unit::set_is_constructed(bool f)
{priv_->is_constructed_ = f;}

/// Compare the current translation unit against another one.
///
/// @param other the other tu to compare against.
///
/// @return true if the two translation units are equal, false
/// otherwise.
bool
translation_unit::operator==(const translation_unit& other)const
{
  if (get_address_size() != other.get_address_size())
    return false;

  return *get_global_scope() == *other.get_global_scope();
}

/// Inequality operator.
///
/// @param o the instance of @ref translation_unit to compare the
/// current instance against.
///
/// @return true iff the current instance is different from @p o.
bool
translation_unit::operator!=(const translation_unit& o) const
{return ! operator==(o);}

/// Ensure that the life time of a function type is bound to the life
/// time of the current translation unit.
///
/// @param ftype the function time which life time to bind to the life
/// time of the current instance of @ref translation_unit.  That is,
/// it's onlyh when the translation unit is destroyed that the
/// function type can be destroyed to.
void
translation_unit::bind_function_type_life_time(function_type_sptr ftype) const
{
  const environment& env = get_environment();

  const_cast<translation_unit*>(this)->priv_->live_fn_types_.push_back(ftype);

  interned_string repr = get_type_name(ftype);
  const_cast<translation_unit*>(this)->get_types().function_types()[repr].
    push_back(ftype);

  // The function type must be out of the same environment as its
  // translation unit.
  {
    const environment& e = ftype->get_environment();
    ABG_ASSERT(&env == &e);
  }

  if (const translation_unit* existing_tu = ftype->get_translation_unit())
    ABG_ASSERT(existing_tu == this);
  else
    ftype->set_translation_unit(const_cast<translation_unit*>(this));

  maybe_update_types_lookup_map(ftype);
}

/// This implements the ir_traversable_base::traverse virtual
/// function.
///
/// @param v the visitor used on the member nodes of the translation
/// unit during the traversal.
///
/// @return true if the entire type IR tree got traversed, false
/// otherwise.
bool
translation_unit::traverse(ir_node_visitor& v)
{return get_global_scope()->traverse(v);}

translation_unit::~translation_unit()
{}

/// Converts a translation_unit::language enumerator into a string.
///
/// @param l the language enumerator to translate.
///
/// @return the resulting string.
string
translation_unit_language_to_string(translation_unit::language l)
{
  switch (l)
    {
    case translation_unit::LANG_UNKNOWN:
      return "LANG_UNKNOWN";
    case translation_unit::LANG_Cobol74:
      return "LANG_Cobol74";
    case translation_unit::LANG_Cobol85:
      return "LANG_Cobol85";
    case translation_unit::LANG_C89:
      return "LANG_C89";
    case translation_unit::LANG_C99:
      return "LANG_C99";
    case translation_unit::LANG_C11:
      return "LANG_C11";
    case translation_unit::LANG_C17:
      return "LANG_C17";
    case translation_unit::LANG_C23:
      return "LANG_C23";
    case translation_unit::LANG_C:
      return "LANG_C";
    case translation_unit::LANG_C_plus_plus_03:
      return "LANG_C_plus_plus_03";
    case translation_unit::LANG_C_plus_plus_11:
      return "LANG_C_plus_plus_11";
    case translation_unit::LANG_C_plus_plus_14:
      return "LANG_C_plus_plus_14";
    case translation_unit::LANG_C_plus_plus_17:
      return "LANG_C_plus_plus_17";
    case translation_unit::LANG_C_plus_plus_20:
      return "LANG_C_plus_plus_20";
    case translation_unit::LANG_C_plus_plus_23:
      return "LANG_C_plus_plus_23";
    case translation_unit::LANG_C_plus_plus:
      return "LANG_C_plus_plus";
    case translation_unit::LANG_OCaml:
      return "LANG_OCaml";
    case translation_unit::LANG_Zig:
      return "LANG_Zig";
    case translation_unit::LANG_ObjC:
      return "LANG_ObjC";
    case translation_unit::LANG_ObjC_plus_plus:
      return "LANG_ObjC_plus_plus";
    case translation_unit::LANG_D:
      return "LANG_D";
    case translation_unit::LANG_Go:
      return "LANG_Go";
    case translation_unit::LANG_Rust:
      return "LANG_Rust";
    case translation_unit::LANG_Fortran77:
      return "LANG_Fortran77";
    case translation_unit::LANG_Fortran90:
      return "LANG_Fortran90";
    case translation_unit::LANG_Fortran95:
      return "LANG_Fortran95";
    case translation_unit::LANG_Fortran18:
      return "LANG_Fortran18";
    case translation_unit::LANG_Fortran23:
      return "LANG_Fortran23";
    case translation_unit::LANG_Ada83:
      return "LANG_Ada83";
    case translation_unit::LANG_Ada95:
      return "LANG_Ada95";
    case translation_unit::LANG_Ada2005:
      return "LANG_Ada2005";
    case translation_unit::LANG_Ada2012:
      return "LANG_Ada2012";
    case translation_unit::LANG_Pascal83:
      return "LANG_Pascal83";
    case translation_unit::LANG_Modula2:
      return "LANG_Modula2";
    case translation_unit::LANG_Java:
      return "LANG_Java";
    case translation_unit::LANG_Kotlin:
      return "LANG_Kotlin";
    case translation_unit::LANG_C_sharp:
      return "LANG_C_sharp";
    case translation_unit::LANG_Python:
      return "LANG_Python";
    case translation_unit::LANG_Ruby:
      return "LANG_Ruby";
    case translation_unit::LANG_PLI:
      return "LANG_PLI";
    case translation_unit::LANG_UPC:
      return "LANG_UPC";
    case translation_unit::LANG_Mips_Assembler:
      return "LANG_Mips_Assembler";
    case translation_unit::LANG_Assembly:
      return "LANG_Assembly";
    case translation_unit::LANG_Crystal:
      return "LANG_Crystal";
    case translation_unit::LANG_HIP:
      return "LANG_HIP";
    case translation_unit::LANG_Mojo:
      return "LANG_Mojo";
    case translation_unit::LANG_GLSL:
      return "LANG_GLSL";
    case translation_unit::LANG_GLSL_ES:
      return "LANG_GLSL_ES";
    case translation_unit::LANG_HLSL:
      return "LANG_HLSL";
    case translation_unit::LANG_OpenCL_CPP:
      return "LANG_OpenCL_CPP";
    case translation_unit::LANG_CPP_for_OpenCL:
      return "LANG_CPP_for_OpenCL";
    case translation_unit::LANG_SYCL:
      return "LANG_SYCL";
    case translation_unit::LANG_Odin:
      return "LANG_Odin";
    case translation_unit::LANG_P4:
      return "LANG_P4";
    case translation_unit::LANG_Metal:
      return "LANG_Metal";
    case translation_unit::LANG_Move:
      return "LANG_Move";
    case translation_unit::LANG_Hylo:
      return "LANG_Hylo";
    }

  return "LANG_UNKNOWN";
}

/// Parse a string representing a language into a
/// translation_unit::language enumerator into a string.
///
/// @param l the string representing the language.
///
/// @return the resulting translation_unit::language enumerator.
translation_unit::language
string_to_translation_unit_language(const string& l)
{
  if (l == "LANG_Cobol74")
    return translation_unit::LANG_Cobol74;
  else if (l == "LANG_Cobol85")
    return translation_unit::LANG_Cobol85;
  else if (l == "LANG_C89")
    return translation_unit::LANG_C89;
  else if (l == "LANG_C99")
    return translation_unit::LANG_C99;
  else if (l == "LANG_C11")
    return translation_unit::LANG_C11;
  else if (l == "LANG_C17")
    return translation_unit::LANG_C17;
  else if (l == "LANG_C23")
    return translation_unit::LANG_C23;
  else if (l == "LANG_C")
    return translation_unit::LANG_C;
  else if (l == "LANG_C_plus_plus_03")
    return translation_unit::LANG_C_plus_plus_03;
  else if (l == "LANG_C_plus_plus_11")
    return translation_unit::LANG_C_plus_plus_11;
  else if (l == "LANG_C_plus_plus_14")
    return translation_unit::LANG_C_plus_plus_14;
  else if (l == "LANG_C_plus_plus_17")
    return translation_unit::LANG_C_plus_plus_17;
  else if (l == "LANG_C_plus_plus_20")
    return translation_unit::LANG_C_plus_plus_20;
  else if (l == "LANG_C_plus_plus_23")
    return translation_unit::LANG_C_plus_plus_23;
  else if (l == "LANG_C_plus_plus")
    return translation_unit::LANG_C_plus_plus;
  else if (l == "LANG_OCaml")
    return translation_unit::LANG_OCaml;
  else if (l == "LANG_ObjC")
    return translation_unit::LANG_ObjC;
  else if (l == "LANG_ObjC_plus_plus")
    return translation_unit::LANG_ObjC_plus_plus;
  else if (l == "LANG_Zig")
    return translation_unit::LANG_Zig;
  else if (l == "LANG_Metal")
    return translation_unit::LANG_Metal;
  else if (l == "LANG_Fortran77")
    return translation_unit::LANG_Fortran77;
  else if (l == "LANG_Fortran90")
    return translation_unit::LANG_Fortran90;
  else if (l == "LANG_Fortran95")
    return translation_unit::LANG_Fortran95;
  else if (l == "LANG_Fortran18")
    return translation_unit::LANG_Fortran23;
  else if (l == "LANG_Ada83")
    return translation_unit::LANG_Ada83;
  else if (l == "LANG_Ada95")
    return translation_unit::LANG_Ada95;
  else if (l == "LANG_Ada2005")
    return translation_unit::LANG_Ada2005;
  else if (l == "LANG_Ada2012")
    return translation_unit::LANG_Ada2012;
  else if (l == "LANG_Pascal83")
    return translation_unit::LANG_Pascal83;
  else if (l == "LANG_Modula2")
    return translation_unit::LANG_Modula2;
  else if (l == "LANG_Java")
    return translation_unit::LANG_Java;
  else if (l == "LANG_Kotlin")
    return translation_unit::LANG_Kotlin;
  else if (l == "LANG_PLI")
    return translation_unit::LANG_PLI;
  else if (l == "LANG_UPC")
    return translation_unit::LANG_UPC;
  else if (l == "LANG_D")
    return translation_unit::LANG_D;
  else if (l == "LANG_Go")
    return translation_unit::LANG_Go;
  else if (l == "LANG_Rust")
    return translation_unit::LANG_Rust;
  else if (l == "LANG_Python")
    return translation_unit::LANG_Python;
  else if (l == "LANG_Ruby")
    return translation_unit::LANG_Ruby;
  else if (l == "LANG_Mips_Assembler")
    return translation_unit::LANG_Mips_Assembler;
  else if (l == "LANG_Assembly")
    return translation_unit::LANG_Assembly;
  else if (l == "LANG_Crystal")
    return translation_unit::LANG_Crystal;
  else if (l == "LANG_HIP")
    return translation_unit::LANG_HIP;
  else if (l == "LANG_C_sharp")
    return translation_unit::LANG_C_sharp;
  else if (l == "LANG_Mojo")
    return translation_unit::LANG_Mojo;
  else if (l == "LANG_GLSL")
    return translation_unit::LANG_GLSL;
  else if (l == "LANG_GLSL_ES")
    return translation_unit::LANG_GLSL_ES;
  else if (l == "LANG_HLSL")
    return translation_unit::LANG_HLSL;
  else if (l == "LANG_OpenCL_CPP")
    return translation_unit::LANG_OpenCL_CPP;
  else if (l == "LANG_CPP_for_OpenCL")
    return translation_unit::LANG_CPP_for_OpenCL;
  else if (l == "LANG_SYCL")
    return translation_unit::LANG_SYCL;
  else if (l == "LANG_Odin")
    return translation_unit::LANG_Odin;
  else if (l == "LANG_P4")
    return translation_unit::LANG_P4;
  else if (l == "LANG_Move")
    return translation_unit::LANG_Move;
  else if (l == "LANG_Hylo")
    return translation_unit::LANG_Hylo;

  return translation_unit::LANG_UNKNOWN;
}

/// Test if a language enumerator designates the C language.
///
/// @param l the language enumerator to consider.
///
/// @return true iff @p l designates the C language.
bool
is_c_language(translation_unit::language l)
{
  return (l == translation_unit::LANG_C89
      || l == translation_unit::LANG_C99
      || l == translation_unit::LANG_C11
      || l == translation_unit::LANG_C17
      || l == translation_unit::LANG_C23
      || l == translation_unit::LANG_C);
}

/// Test if a language enumerator designates the C++ language.
///
/// @param l the language enumerator to consider.
///
/// @return true iff @p l designates the C++ language.
bool
is_cplus_plus_language(translation_unit::language l)
{
  return (l == translation_unit::LANG_C_plus_plus_03
      || l == translation_unit::LANG_C_plus_plus_11
      || l == translation_unit::LANG_C_plus_plus_14
      || l == translation_unit::LANG_C_plus_plus_20
      || l == translation_unit::LANG_C_plus_plus_23
      || l == translation_unit::LANG_C_plus_plus);
}

/// Test if a language enumerator designates the Java language.
///
/// @param l the language enumerator to consider.
///
/// @return true iff @p l designates the Java language.
bool
is_java_language(translation_unit::language l)
{return l == translation_unit::LANG_Java;}

/// Test if a language enumerator designates the Ada language.
///
/// @param l the language enumerator to consider.
///
/// @return true iff @p l designates the Ada language.
bool
is_ada_language(translation_unit::language l)
{
  return (l == translation_unit::LANG_Ada83
      || l == translation_unit::LANG_Ada95
      || l == translation_unit::LANG_Ada2005
      || l == translation_unit::LANG_Ada2012);
}

/// A deep comparison operator for pointers to translation units.
///
/// @param l the first translation unit to consider for the comparison.
///
/// @param r the second translation unit to consider for the comparison.
///
/// @return true if the two translation units are equal, false otherwise.
bool
operator==(const translation_unit_sptr& l, const translation_unit_sptr& r)
{
  if (l.get() == r.get())
    return true;

  if (!!l != !!r)
    return false;

  return *l == *r;
}

/// A deep inequality operator for pointers to translation units.
///
/// @param l the first translation unit to consider for the comparison.
///
/// @param r the second translation unit to consider for the comparison.
///
/// @return true iff the two translation units are different.
bool
operator!=(const translation_unit_sptr& l, const translation_unit_sptr& r)
{return !operator==(l, r);}

// </translation_unit stuff>

// <elf_symbol stuff>
struct elf_symbol::priv
{
  const environment&    env_;
  size_t        index_;
  size_t        size_;
  string        name_;
  elf_symbol::type  type_;
  elf_symbol::binding   binding_;
  elf_symbol::version   version_;
  elf_symbol::visibility visibility_;
  bool          is_defined_;
  // This flag below says if the symbol is a common elf symbol.  In
  // relocatable files, a common symbol is a symbol defined in a
  // section of kind SHN_COMMON.
  //
  // Note that a symbol of kind STT_COMMON is also considered a common
  // symbol.  Here is what the gABI says about STT_COMMON and
  // SHN_COMMON:
  //
  //     Symbols with type STT_COMMON label uninitialized common
  //     blocks. In relocatable objects, these symbols are not
  //     allocated and must have the special section index SHN_COMMON
  //     (see below). In shared objects and executables these symbols
  //     must be allocated to some section in the defining object.
  //
  //     In relocatable objects, symbols with type STT_COMMON are
  //     treated just as other symbols with index SHN_COMMON. If the
  //     link-editor allocates space for the SHN_COMMON symbol in an
  //     output section of the object it is producing, it must
  //     preserve the type of the output symbol as STT_COMMON.
  //
  //     When the dynamic linker encounters a reference to a symbol
  //     that resolves to a definition of type STT_COMMON, it may (but
  //     is not required to) change its symbol resolution rules as
  //     follows: instead of binding the reference to the first symbol
  //     found with the given name, the dynamic linker searches for
  //     the first symbol with that name with type other than
  //     STT_COMMON. If no such symbol is found, it looks for the
  //     STT_COMMON definition of that name that has the largest size.
  bool          is_common_;
  bool          is_in_ksymtab_;
  abg_compat::optional<uint32_t>    crc_;
  abg_compat::optional<std::string> namespace_;
  bool          is_suppressed_;
  elf_symbol_wptr   main_symbol_;
  elf_symbol_wptr   next_alias_;
  elf_symbol_wptr   next_common_instance_;
  string        id_string_;

  priv(const environment& e)
    : env_(e),
      index_(),
      size_(),
      type_(elf_symbol::NOTYPE_TYPE),
      binding_(elf_symbol::GLOBAL_BINDING),
      visibility_(elf_symbol::DEFAULT_VISIBILITY),
      is_defined_(false),
      is_common_(false),
      is_in_ksymtab_(false),
      crc_(),
      namespace_(),
      is_suppressed_(false)
  {}

  priv(const environment&     e,
       size_t             i,
       size_t             s,
       const string&          n,
       elf_symbol::type       t,
       elf_symbol::binding    b,
       bool           d,
       bool           c,
       const elf_symbol::version& ve,
       elf_symbol::visibility     vi,
       bool           is_in_ksymtab,
       const abg_compat::optional<uint32_t>&    crc,
       const abg_compat::optional<std::string>& ns,
       bool           is_suppressed)
    : env_(e),
      index_(i),
      size_(s),
      name_(n),
      type_(t),
      binding_(b),
      version_(ve),
      visibility_(vi),
      is_defined_(d),
      is_common_(c),
      is_in_ksymtab_(is_in_ksymtab),
      crc_(crc),
      namespace_(ns),
      is_suppressed_(is_suppressed)
  {
    if (!is_common_)
      is_common_ = type_ == COMMON_TYPE;
  }
}; // end struct elf_symbol::priv

/// Constructor of the @ref elf_symbol type.
///
/// Note that this constructor is private, so client code cannot use
/// it to create instances of @ref elf_symbol.  Rather, client code
/// should use the @ref elf_symbol::create() function to create
/// instances of @ref elf_symbol instead.
///
/// @param e the environment we are operating from.
///
/// @param i the index of the symbol in the (ELF) symbol table.
///
/// @param s the size of the symbol.
///
/// @param n the name of the symbol.
///
/// @param t the type of the symbol.
///
/// @param b the binding of the symbol.
///
/// @param d true if the symbol is defined, false otherwise.
///
/// @param c true if the symbol is a common symbol, false otherwise.
///
/// @param ve the version of the symbol.
///
/// @param vi the visibility of the symbol.
///
/// @param crc the CRC (modversions) value of Linux Kernel symbols
///
/// @param ns the namespace of Linux Kernel symbols, if any
elf_symbol::elf_symbol(const environment& e,
               size_t         i,
               size_t         s,
               const string&      n,
               type       t,
               binding        b,
               bool       d,
               bool       c,
               const version&     ve,
               visibility     vi,
               bool       is_in_ksymtab,
               const abg_compat::optional<uint32_t>&    crc,
               const abg_compat::optional<std::string>& ns,
               bool       is_suppressed)
  : priv_(new priv(e,
           i,
           s,
           n,
           t,
           b,
           d,
           c,
           ve,
           vi,
           is_in_ksymtab,
           crc,
           ns,
           is_suppressed))
{}

/// Factory of instances of @ref elf_symbol.
///
/// This is the function to use to create instances of @ref elf_symbol.
///
/// @param e the environment we are operating from.
///
/// @param i the index of the symbol in the (ELF) symbol table.
///
/// @param s the size of the symbol.
///
/// @param n the name of the symbol.
///
/// @param t the type of the symbol.
///
/// @param b the binding of the symbol.
///
/// @param d true if the symbol is defined, false otherwise.
///
/// @param c true if the symbol is a common symbol.
///
/// @param ve the version of the symbol.
///
/// @param vi the visibility of the symbol.
///
/// @param crc the CRC (modversions) value of Linux Kernel symbols
///
/// @param ns the namespace of Linux Kernel symbols, if any
///
/// @return a (smart) pointer to a newly created instance of @ref
/// elf_symbol.
elf_symbol_sptr
elf_symbol::create(const environment& e,
           size_t         i,
           size_t         s,
           const string&      n,
           type           t,
           binding        b,
           bool           d,
           bool           c,
           const version&     ve,
           visibility         vi,
           bool           is_in_ksymtab,
           const abg_compat::optional<uint32_t>&    crc,
           const abg_compat::optional<std::string>& ns,
           bool           is_suppressed)
{
  elf_symbol_sptr sym(new elf_symbol(e, i, s, n, t, b, d, c, ve, vi,
                     is_in_ksymtab, crc, ns, is_suppressed));
  sym->priv_->main_symbol_ = sym;
  return sym;
}

/// Test textual equality between two symbols.
///
/// Textual equality means that the aliases of the compared symbols
/// are not taken into account.  Only the name, type, and version of
/// the symbols are compared.
///
/// @parm l the first ELF symbol to take into consideration in the
/// comparison.
///
/// @param r the second ELF symbol to take into consideration in the
/// comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff it's non-null and if the function returns false.
///
/// @return true iff the two symbols are textually equal.
static bool
textually_equals(const elf_symbol&l, const elf_symbol&r,
         change_kind* k = nullptr)
{
  bool equals = (l.get_name() == r.get_name()
         && l.get_type() == r.get_type()
         && l.is_public() == r.is_public()
         && l.is_defined() == r.is_defined()
         && l.is_common_symbol() == r.is_common_symbol()
         && l.get_version() == r.get_version()
         && l.get_crc() == r.get_crc()
         && l.get_namespace() == r.get_namespace());

  if (!equals)
    if (k)
      *k |= LOCAL_NON_TYPE_CHANGE_KIND;

  if (equals && l.is_variable())
    // These are variable symbols.  Let's compare their symbol size.
    // The symbol size in this case is the size taken by the storage
    // of the variable.  If that size changes, then it's an ABI
    // change.
    if (l.get_size() != r.get_size())
      {
    equals = false;
    if (k)
      *k| LOCAL_TYPE_CHANGE_KIND;
      }

  return equals;
}

/// Getter of the environment used by the current instance of @ref
/// elf_symbol.
///
/// @return the enviroment used by the current instance of @ref elf_symbol.
const environment&
elf_symbol::get_environment() const
{return priv_->env_;}

/// Getter for the index
///
/// @return the index of the symbol.
size_t
elf_symbol::get_index() const
{return priv_->index_;}

/// Setter for the index.
///
/// @param s the new index.
void
elf_symbol::set_index(size_t s)
{priv_->index_ = s;}

/// Getter for the name of the @ref elf_symbol.
///
/// @return a reference to the name of the @ref symbol.
const string&
elf_symbol::get_name() const
{return priv_->name_;}

/// Setter for the name of the current intance of @ref elf_symbol.
///
/// @param n the new name.
void
elf_symbol::set_name(const string& n)
{
  priv_->name_ = n;
  priv_->id_string_.clear();
}

/// Getter for the type of the current instance of @ref elf_symbol.
///
/// @return the type of the elf symbol.
elf_symbol::type
elf_symbol::get_type() const
{return priv_->type_;}

/// Setter for the type of the current instance of @ref elf_symbol.
///
/// @param t the new symbol type.
void
elf_symbol::set_type(type t)
{priv_->type_ = t;}

/// Getter of the size of the symbol.
///
/// @return the size of the symbol, in bytes.
size_t
elf_symbol::get_size() const
{return priv_->size_;}

/// Setter of the size of the symbol.
///
/// @param size the new size of the symbol, in bytes.
void
elf_symbol::set_size(size_t size)
{priv_->size_ = size;}

/// Getter for the binding of the current instance of @ref elf_symbol.
///
/// @return the binding of the symbol.
elf_symbol::binding
elf_symbol::get_binding() const
{return priv_->binding_;}

/// Setter for the binding of the current instance of @ref elf_symbol.
///
/// @param b the new binding.
void
elf_symbol::set_binding(binding b)
{priv_->binding_ = b;}

/// Getter for the version of the current instanc of @ref elf_symbol.
///
/// @return the version of the elf symbol.
elf_symbol::version&
elf_symbol::get_version() const
{return priv_->version_;}

/// Setter for the version of the current instance of @ref elf_symbol.
///
/// @param v the new version of the elf symbol.
void
elf_symbol::set_version(const version& v)
{
  priv_->version_ = v;
  priv_->id_string_.clear();
}

/// Setter of the visibility of the current instance of @ref
/// elf_symbol.
///
/// @param v the new visibility of the elf symbol.
void
elf_symbol::set_visibility(visibility v)
{priv_->visibility_ = v;}

/// Getter of the visibility of the current instance of @ref
/// elf_symbol.
///
/// @return the visibility of the elf symbol.
elf_symbol::visibility
elf_symbol::get_visibility() const
{return priv_->visibility_;}

/// Test if the current instance of @ref elf_symbol is defined or not.
///
/// @return true if the current instance of @ref elf_symbol is
/// defined, false otherwise.
bool
elf_symbol::is_defined() const
{return priv_->is_defined_;}

/// Sets a flag saying if the current instance of @ref elf_symbol is
/// defined
///
/// @param b the new value of the flag.
void
elf_symbol::is_defined(bool d)
{priv_->is_defined_ = d;}

/// Test if the current instance of @ref elf_symbol is public or not.
///
/// This tests if the symbol is defined, has default or protected
///visibility, and either:
///     - has global binding
///     - has weak binding
///     - or has a GNU_UNIQUE binding.
///
/// return true if the current instance of @ref elf_symbol is public,
/// false otherwise.
bool
elf_symbol::is_public() const
{
  return (is_defined()
      && (get_binding() == GLOBAL_BINDING
          || get_binding() == WEAK_BINDING
          || get_binding() == GNU_UNIQUE_BINDING)
      && (get_visibility() == DEFAULT_VISIBILITY
          || get_visibility() == PROTECTED_VISIBILITY));
}

/// Test if the current instance of @ref elf_symbol is a function
/// symbol or not.
///
/// @return true if the current instance of @ref elf_symbol is a
/// function symbol, false otherwise.
bool
elf_symbol::is_function() const
{return get_type() == FUNC_TYPE || get_type() == GNU_IFUNC_TYPE;}

/// Test if the current instance of @ref elf_symbol is a variable
/// symbol or not.
///
/// @return true if the current instance of @ref elf_symbol is a
/// variable symbol, false otherwise.
bool
elf_symbol::is_variable() const
{
    return (get_type() == OBJECT_TYPE
        || get_type() == TLS_TYPE
        // It appears that undefined variables have NOTYPE type.
        || (get_type() == NOTYPE_TYPE
        && !is_defined()));
}

/// Getter of the 'is-in-ksymtab' property.
///
/// @return true iff the current symbol is in the Linux Kernel
/// specific 'ksymtab' symbol table.
bool
elf_symbol::is_in_ksymtab() const
{return priv_->is_in_ksymtab_;}

/// Setter of the 'is-in-ksymtab' property.
///
/// @param is_in_ksymtab this is true iff the current symbol is in the
/// Linux Kernel specific 'ksymtab' symbol table.
void
elf_symbol::set_is_in_ksymtab(bool is_in_ksymtab)
{priv_->is_in_ksymtab_ = is_in_ksymtab;}

/// Getter of the 'crc' property.
///
/// @return the CRC (modversions) value for Linux Kernel symbols, if any
const abg_compat::optional<uint32_t>&
elf_symbol::get_crc() const
{return priv_->crc_;}

/// Setter of the 'crc' property.
///
/// @param crc the new CRC (modversions) value for Linux Kernel symbols
void
elf_symbol::set_crc(const abg_compat::optional<uint32_t>& crc)
{priv_->crc_ = crc;}

/// Getter of the 'namespace' property.
///
/// @return the namespace for Linux Kernel symbols, if any
const abg_compat::optional<std::string>&
elf_symbol::get_namespace() const
{return priv_->namespace_;}

/// Setter of the 'namespace' property.
///
/// @param ns the new namespace for Linux Kernel symbols, if any
void
elf_symbol::set_namespace(const abg_compat::optional<std::string>& ns)
{priv_->namespace_ = ns;}

/// Getter for the 'is-suppressed' property.
///
/// @return true iff the current symbol has been suppressed by a
/// suppression specification that was provided in the context that
/// led to the creation of the corpus this ELF symbol belongs to.
bool
elf_symbol::is_suppressed() const
{return priv_->is_suppressed_;}

/// Setter for the 'is-suppressed' property.
///
/// @param true iff the current symbol has been suppressed by a
/// suppression specification that was provided in the context that
/// led to the creation of the corpus this ELF symbol belongs to.
void
elf_symbol::set_is_suppressed(bool is_suppressed)
{priv_->is_suppressed_ = is_suppressed;}

/// @name Elf symbol aliases
///
/// An alias A for an elf symbol S is a symbol that is defined at the
/// same address as S.  S is chained to A through the
/// elf_symbol::get_next_alias() method.
///
/// When there are several aliases to a symbol, the main symbol is the
/// the first symbol found in the symbol table for a given address.
///
/// The alias chain is circular.  That means if S is the main symbol
/// and A is the alias, S is chained to A and A
/// is chained back to the main symbol S.  The last alias in an alias
///chain is always chained to the main symbol.
///
/// Thus, when looping over the aliases of an elf_symbol A, detecting
/// an alias that is equal to the main symbol should logically be a
/// loop exit condition.
///
/// Accessing and adding aliases for instances of elf_symbol is done
/// through the member functions below.

/// @{

/// Get the main symbol of an alias chain.
///
///@return the main symbol.
const elf_symbol_sptr
elf_symbol::get_main_symbol() const
{return priv_->main_symbol_.lock();}

/// Get the main symbol of an alias chain.
///
///@return the main symbol.
elf_symbol_sptr
elf_symbol::get_main_symbol()
{return priv_->main_symbol_.lock();}

/// Tests whether this symbol is the main symbol.
///
/// @return true iff this symbol is the main symbol.
bool
elf_symbol::is_main_symbol() const
{return get_main_symbol().get() == this;}

/// Get the next alias of the current symbol.
///
///@return the alias, or NULL if there is no alias.
elf_symbol_sptr
elf_symbol::get_next_alias() const
{return priv_->next_alias_.lock();}


/// Check if the current elf_symbol has an alias.
///
///@return true iff the current elf_symbol has an alias.
bool
elf_symbol::has_aliases() const
{return bool(get_next_alias());}

/// Get the number of aliases to this elf symbol
///
/// @return the number of aliases to this elf symbol.
int
elf_symbol::get_number_of_aliases() const
{
  int result = 0;

  for (elf_symbol_sptr a = get_next_alias();
       a && a.get() != get_main_symbol().get();
       a = a->get_next_alias())
    ++result;

  return result;
}

/// Add an alias to the current elf symbol.
///
/// @param alias the new alias.  Note that this elf_symbol should *NOT*
/// have aliases prior to the invocation of this function.
void
elf_symbol::add_alias(const elf_symbol_sptr& alias)
{
  if (!alias)
    return;

  ABG_ASSERT(!alias->has_aliases());
  ABG_ASSERT(is_main_symbol());

  if (has_aliases())
    {
      elf_symbol_sptr last_alias;
      for (elf_symbol_sptr a = get_next_alias();
       a && !a->is_main_symbol();
       a = a->get_next_alias())
    {
      if (a->get_next_alias()->is_main_symbol())
        {
          ABG_ASSERT(last_alias == 0);
          last_alias = a;
        }
    }
      ABG_ASSERT(last_alias);

      last_alias->priv_->next_alias_ = alias;
    }
  else
    priv_->next_alias_ = alias;

  alias->priv_->next_alias_ = get_main_symbol();
  alias->priv_->main_symbol_ = get_main_symbol();
}

/// Update the main symbol for a group of aliased symbols
///
/// If after the construction of the symbols (in order of discovery), the
/// actual main symbol can be identified (e.g. as the symbol that actually is
/// defined in the code), this method offers a way of updating the main symbol
/// through one of the aliased symbols.
///
/// For that, locate the new main symbol by name and update all references to
/// the main symbol among the group of aliased symbols.
///
/// @param name the name of the main symbol
///
/// @return the new main elf_symbol
elf_symbol_sptr
elf_symbol::update_main_symbol(const std::string& name)
{
  ABG_ASSERT(is_main_symbol());
  if (!has_aliases() || get_name() == name)
    return get_main_symbol();

  // find the new main symbol
  elf_symbol_sptr new_main;
  // we've already checked this; check the rest of the aliases
  for (elf_symbol_sptr a = get_next_alias(); a.get() != this;
       a = a->get_next_alias())
    if (a->get_name() == name)
      {
    new_main = a;
    break;
      }

  if (!new_main)
    return get_main_symbol();

  // now update all main symbol references
  priv_->main_symbol_ = new_main;
  for (elf_symbol_sptr a = get_next_alias(); a.get() != this;
       a = a->get_next_alias())
    a->priv_->main_symbol_ = new_main;

  return new_main;
}

/// Return true if the symbol is a common one.
///
/// @return true iff the symbol is common.
bool
elf_symbol::is_common_symbol() const
{return priv_->is_common_;}

/// Return true if this common common symbol has other common instances.
///
/// A common instance of a given common symbol is another common
/// symbol with the same name.  Those exist in relocatable files.  The
/// linker normally allocates all the instances into a common block in
/// the final output file.
///
/// Note that the current object must be a common symbol, otherwise,
/// this function aborts.
///
/// @return true iff the current common symbol has other common
/// instances.
bool
elf_symbol::has_other_common_instances() const
{
  ABG_ASSERT(is_common_symbol());
  return bool(get_next_common_instance());
}

/// Get the next common instance of the current common symbol.
///
/// A common instance of a given common symbol is another common
/// symbol with the same name.  Those exist in relocatable files.  The
/// linker normally allocates all the instances into a common block in
/// the final output file.
///
/// @return the next common instance, or nil if there is not any.
elf_symbol_sptr
elf_symbol::get_next_common_instance() const
{return priv_->next_common_instance_.lock();}

/// Add a common instance to the current common elf symbol.
///
/// Note that this symbol must be the main symbol.  Being the main
/// symbol means being the first common symbol to appear in the symbol
/// table.
///
/// @param common the other common instance to add.
void
elf_symbol::add_common_instance(const elf_symbol_sptr& common)
{
  if (!common)
    return;

  ABG_ASSERT(!common->has_other_common_instances());
  ABG_ASSERT(is_common_symbol());
  ABG_ASSERT(is_main_symbol());

  if (has_other_common_instances())
    {
      elf_symbol_sptr last_common_instance;
      for (elf_symbol_sptr c = get_next_common_instance();
       c && (c.get() != get_main_symbol().get());
       c = c->get_next_common_instance())
    {
      if (c->get_next_common_instance().get() == get_main_symbol().get())
        {
          ABG_ASSERT(last_common_instance == 0);
          last_common_instance = c;
        }
    }
      ABG_ASSERT(last_common_instance);

      last_common_instance->priv_->next_common_instance_ = common;
    }
  else
    priv_->next_common_instance_ = common;

  common->priv_->next_common_instance_ = get_main_symbol();
  common->priv_->main_symbol_ = get_main_symbol();
}

/// Get a string that is representative of a given elf_symbol.
///
/// If the symbol has a version, then the ID string is the
/// concatenation of the name of the symbol, the '@' character, and
/// the version of the symbol.  If the version is the default version
/// of the symbol then the '@' character is replaced by a "@@" string.
///
/// Otherwise, if the symbol does not have any version, this function
/// returns the name of the symbol.
///
/// @return a the ID string.
const string&
elf_symbol::get_id_string() const
{
  if (priv_->id_string_.empty())
    {
      string s = get_name ();

      if (!get_version().is_empty())
    {
      if (get_version().is_default())
        s += "@@";
      else
        s += "@";
      s += get_version().str();
    }
      priv_->id_string_ = s;
    }

  return priv_->id_string_;
}

/// From the aliases of the current symbol, lookup one with a given name.
///
/// @param name the name of symbol alias we are looking for.
///
/// @return the symbol alias that has the name @p name, or nil if none
/// has been found.
elf_symbol_sptr
elf_symbol::get_alias_from_name(const string& name) const
{
  if (name == get_name())
    return elf_symbol_sptr(priv_->main_symbol_);

   for (elf_symbol_sptr a = get_next_alias();
    a && a.get() != get_main_symbol().get();
    a = a->get_next_alias())
     if (a->get_name() == name)
       return a;

   return elf_symbol_sptr();
}

/// In the list of aliases of a given elf symbol, get the alias that
/// equals this current symbol.
///
/// @param other the elf symbol to get the potential aliases from.
///
/// @return the alias of @p other that texually equals the current
/// symbol, or nil if no alias textually equals the current symbol.
elf_symbol_sptr
elf_symbol::get_alias_which_equals(const elf_symbol& other) const
{
  for (elf_symbol_sptr a = other.get_next_alias();
       a && a.get() != a->get_main_symbol().get();
       a = a->get_next_alias())
    if (textually_equals(*this, *a))
      return a;
  return elf_symbol_sptr();
}

/// Return a comma separated list of the id of the current symbol as
/// well as the id string of its aliases.
///
/// @param syms a map of all the symbols of the corpus the current
/// symbol belongs to.
///
/// @param include_symbol_itself if set to true, then the name of the
/// current symbol is included in the list of alias names that is emitted.
///
/// @return the string.
string
elf_symbol::get_aliases_id_string(const string_elf_symbols_map_type& syms,
                  bool include_symbol_itself) const
{
  string result;

  if (include_symbol_itself)
      result = get_id_string();

  vector<elf_symbol_sptr> aliases;
  compute_aliases_for_elf_symbol(*this, syms, aliases);
  if (!aliases.empty() && include_symbol_itself)
    result += ", ";

  for (vector<elf_symbol_sptr>::const_iterator i = aliases.begin();
       i != aliases.end();
       ++i)
    {
      if (i != aliases.begin())
    result += ", ";
      result += (*i)->get_id_string();
    }
  return result;
}

/// Return a comma separated list of the id of the current symbol as
/// well as the id string of its aliases.
///
/// @param include_symbol_itself if set to true, then the name of the
/// current symbol is included in the list of alias names that is emitted.
///
/// @return the string.
string
elf_symbol::get_aliases_id_string(bool include_symbol_itself) const
{
  vector<elf_symbol_sptr> aliases;
  if (include_symbol_itself)
    aliases.push_back(get_main_symbol());

  for (elf_symbol_sptr a = get_next_alias();
       a && a.get() != get_main_symbol().get();
       a = a->get_next_alias())
    aliases.push_back(a);

  string result;
  for (vector<elf_symbol_sptr>::const_iterator i = aliases.begin();
       i != aliases.end();
       ++i)
    {
      if (i != aliases.begin())
    result += ", ";
      result += (*i)->get_id_string();
    }

  return result;
}

/// Given the ID of a symbol, get the name and the version of said
/// symbol.
///
/// @param id the symbol ID to consider.
///
/// @param name the symbol name extracted from the ID.  This is set
/// only if the function returned true.
///
/// @param ver the symbol version extracted from the ID.
bool
elf_symbol::get_name_and_version_from_id(const string&  id,
                     string&    name,
                     string&    ver)
{
  name.clear(), ver.clear();

  string::size_type i = id.find('@');
  if (i == string::npos)
    {
      name = id;
      return true;
    }

  name = id.substr(0, i);
  ++i;

  if (i >= id.size())
    return true;

  string::size_type j = id.find('@', i);
  if (j == string::npos)
    j = i;
  else
    ++j;

  if (j >= id.size())
    {
      ver = "";
      return true;
    }

  ver = id.substr(j);
  return true;
}

///@}

/// Test if two main symbols are textually equal, or, if they have
/// aliases that are textually equal.
///
/// @param other the symbol to compare against.
///
/// @return true iff the current instance of elf symbol equals the @p
/// other.
bool
elf_symbol::operator==(const elf_symbol& other) const
{
  bool are_equal = textually_equals(*this, other);
  if (!are_equal)
    are_equal = bool(get_alias_which_equals(other));
  return are_equal;
}

/// Test if the current symbol aliases another one.
///
/// @param o the other symbol to test against.
///
/// @return true iff the current symbol aliases @p o.
bool
elf_symbol::does_alias(const elf_symbol& o) const
{
  if (*this == o)
    return true;

  if (get_main_symbol() == o.get_main_symbol())
    return true;

  for (elf_symbol_sptr a = get_next_alias();
       a && !a->is_main_symbol();
       a = a->get_next_alias())
    {
      if (o == *a)
    return true;
    }
  return false;
}

/// Equality operator for smart pointers to elf_symbol.
///
/// @param lhs the first elf symbol to consider.
///
/// @param rhs the second elf symbol to consider.
///
/// @return true iff @p lhs equals @p rhs.
bool
operator==(const elf_symbol_sptr& lhs, const elf_symbol_sptr& rhs)
{
  if (!!lhs != !!rhs)
    return false;

  if (!lhs)
    return true;

  return *lhs == *rhs;
}

/// Inequality operator for smart pointers to elf_symbol.
///
/// @param lhs the first elf symbol to consider.
///
/// @param rhs the second elf symbol to consider.
///
/// @return true iff @p lhs is different from @p rhs.
bool
operator!=(const elf_symbol_sptr& lhs, const elf_symbol_sptr& rhs)
{return !operator==(lhs, rhs);}

/// Test if two symbols alias.
///
/// @param s1 the first symbol to consider.
///
/// @param s2 the second symbol to consider.
///
/// @return true if @p s1 aliases @p s2.
bool
elf_symbols_alias(const elf_symbol& s1, const elf_symbol& s2)
{return s1.does_alias(s2) || s2.does_alias(s1);}

void
compute_aliases_for_elf_symbol(const elf_symbol& sym,
                   const string_elf_symbols_map_type& symtab,
                   vector<elf_symbol_sptr>& aliases)
{

  if (elf_symbol_sptr a = sym.get_next_alias())
    for (; a && !a->is_main_symbol(); a = a->get_next_alias())
      aliases.push_back(a);
  else
    {
      // No pre-linked alias chain (e.g. symbols loaded from abixml).
      // Look up by name in the symtab (O(1) hash lookup) instead of
      // scanning the entire table (which was O(N) per call).
      string_elf_symbols_map_type::const_iterator i =
    symtab.find(sym.get_name());
      if (i == symtab.end())
    return;

      for (elf_symbols::const_iterator j = i->second.begin();
       j != i->second.end();
       ++j)
    {
      if (**j == sym)
        for (elf_symbol_sptr s = (*j)->get_next_alias();
         s && !s->is_main_symbol();
         s = s->get_next_alias())
          aliases.push_back(s);
      else
        for (elf_symbol_sptr s = (*j)->get_next_alias();
         s && !s->is_main_symbol();
         s = s->get_next_alias())
          if (*s == sym)
        aliases.push_back(*j);
    }
    }
}

/// Test if two symbols alias.
///
/// @param s1 the first symbol to consider.
///
/// @param s2 the second symbol to consider.
///
/// @return true if @p s1 aliases @p s2.
bool
elf_symbols_alias(const elf_symbol* s1, const elf_symbol* s2)
{
  if (!!s1 != !!s2)
    return false;
  if (s1 == s2)
    return true;
  return elf_symbols_alias(*s1, *s2);
}

/// Test if two symbols alias.
///
/// @param s1 the first symbol to consider.
///
/// @param s2 the second symbol to consider.
///
/// @return true if @p s1 aliases @p s2.
bool
elf_symbols_alias(const elf_symbol_sptr s1, const elf_symbol_sptr s2)
{return elf_symbols_alias(s1.get(), s2.get());}

/// Serialize an instance of @ref symbol_type and stream it to a given
/// output stream.
///
/// @param o the output stream to serialize the symbole type to.
///
/// @param t the symbol type to serialize.
std::ostream&
operator<<(std::ostream& o, elf_symbol::type t)
{
  string repr;

  switch (t)
    {
    case elf_symbol::NOTYPE_TYPE:
      repr = "unspecified symbol type";
      break;
    case elf_symbol::OBJECT_TYPE:
      repr = "variable symbol type";
      break;
    case elf_symbol::FUNC_TYPE:
      repr = "function symbol type";
      break;
    case elf_symbol::SECTION_TYPE:
      repr = "section symbol type";
      break;
    case elf_symbol::FILE_TYPE:
      repr = "file symbol type";
      break;
    case elf_symbol::COMMON_TYPE:
      repr = "common data object symbol type";
      break;
    case elf_symbol::TLS_TYPE:
      repr = "thread local data object symbol type";
      break;
    case elf_symbol::GNU_IFUNC_TYPE:
      repr = "indirect function symbol type";
      break;
    default:
      {
    std::ostringstream s;
    s << "unknown symbol type (" << (char)t << ')';
    repr = s.str();
      }
      break;
    }

  o << repr;
  return o;
}

/// Serialize an instance of @ref symbol_binding and stream it to a
/// given output stream.
///
/// @param o the output stream to serialize the symbole type to.
///
/// @param b the symbol binding to serialize.
std::ostream&
operator<<(std::ostream& o, elf_symbol::binding b)
{
  string repr;

  switch (b)
    {
    case elf_symbol::LOCAL_BINDING:
      repr = "local binding";
      break;
    case elf_symbol::GLOBAL_BINDING:
      repr = "global binding";
      break;
    case elf_symbol::WEAK_BINDING:
      repr = "weak binding";
      break;
    case elf_symbol::GNU_UNIQUE_BINDING:
      repr = "GNU unique binding";
      break;
    default:
      {
    std::ostringstream s;
    s << "unknown binding (" << (unsigned char) b << ")";
    repr = s.str();
      }
      break;
    }

  o << repr;
  return o;
}

/// Serialize an instance of @ref elf_symbol::visibility and stream it
/// to a given output stream.
///
/// @param o the output stream to serialize the symbole type to.
///
/// @param v the symbol visibility to serialize.
std::ostream&
operator<<(std::ostream& o, elf_symbol::visibility v)
{
  string repr;

  switch (v)
    {
    case elf_symbol::DEFAULT_VISIBILITY:
      repr = "default visibility";
      break;
    case elf_symbol::PROTECTED_VISIBILITY:
      repr = "protected visibility";
      break;
    case elf_symbol::HIDDEN_VISIBILITY:
      repr = "hidden visibility";
      break;
    case elf_symbol::INTERNAL_VISIBILITY:
      repr = "internal visibility";
      break;
    default:
      {
    std::ostringstream s;
    s << "unknown visibility (" << (unsigned char) v << ")";
    repr = s.str();
      }
      break;
    }

  o << repr;
  return o;
}

/// Convert a string representing a symbol type into an
/// elf_symbol::type.
///
///@param s the string to convert.
///
///@param t the resulting elf_symbol::type.
///
/// @return true iff the conversion completed successfully.
bool
string_to_elf_symbol_type(const string& s, elf_symbol::type& t)
{
  if (s == "no-type")
    t = elf_symbol::NOTYPE_TYPE;
  else if (s == "object-type")
    t = elf_symbol::OBJECT_TYPE;
  else if (s == "func-type")
    t = elf_symbol::FUNC_TYPE;
  else if (s == "section-type")
    t = elf_symbol::SECTION_TYPE;
  else if (s == "file-type")
    t = elf_symbol::FILE_TYPE;
  else if (s == "common-type")
    t = elf_symbol::COMMON_TYPE;
  else if (s == "tls-type")
    t = elf_symbol::TLS_TYPE;
  else if (s == "gnu-ifunc-type")
    t = elf_symbol::GNU_IFUNC_TYPE;
  else
    return false;

  return true;
}

/// Convert a string representing a an elf symbol binding into an
/// elf_symbol::binding.
///
/// @param s the string to convert.
///
/// @param b the resulting elf_symbol::binding.
///
/// @return true iff the conversion completed successfully.
bool
string_to_elf_symbol_binding(const string& s, elf_symbol::binding& b)
{
    if (s == "local-binding")
      b = elf_symbol::LOCAL_BINDING;
    else if (s == "global-binding")
      b = elf_symbol::GLOBAL_BINDING;
    else if (s == "weak-binding")
      b = elf_symbol::WEAK_BINDING;
    else if (s == "gnu-unique-binding")
      b = elf_symbol::GNU_UNIQUE_BINDING;
    else
      return false;

    return true;
}

/// Convert a string representing a an elf symbol visibility into an
/// elf_symbol::visibility.
///
/// @param s the string to convert.
///
/// @param b the resulting elf_symbol::visibility.
///
/// @return true iff the conversion completed successfully.
bool
string_to_elf_symbol_visibility(const string& s, elf_symbol::visibility& v)
{
  if (s == "default-visibility")
    v = elf_symbol::DEFAULT_VISIBILITY;
  else if (s == "protected-visibility")
    v = elf_symbol::PROTECTED_VISIBILITY;
  else if (s == "hidden-visibility")
    v = elf_symbol::HIDDEN_VISIBILITY;
  else if (s == "internal-visibility")
    v = elf_symbol::INTERNAL_VISIBILITY;
  else
    return false;

  return true;
}

/// Test if the type of an ELF symbol denotes a function symbol.
///
/// @param t the type of the ELF symbol.
///
/// @return true iff elf symbol type @p t denotes a function symbol
/// type.
bool
elf_symbol_is_function(elf_symbol::type t)
{return t == elf_symbol::FUNC_TYPE;}

/// Test if the type of an ELF symbol denotes a function symbol.
///
/// @param t the type of the ELF symbol.
///
/// @return true iff elf symbol type @p t denotes a function symbol
/// type.
bool
elf_symbol_is_variable(elf_symbol::type t)
{return t == elf_symbol::OBJECT_TYPE;}

// <elf_symbol::version stuff>

struct elf_symbol::version::priv
{
  string    version_;
  bool      is_default_;

  priv()
    : is_default_(false)
  {}

  priv(const string& v,
       bool d)
    : version_(v),
      is_default_(d)
  {}
}; // end struct elf_symbol::version::priv

elf_symbol::version::version()
  : priv_(new priv)
{}

/// @param v the name of the version.
///
/// @param is_default true if this is a default version.
elf_symbol::version::version(const string& v,
                 bool is_default)
  : priv_(new priv(v, is_default))
{}

elf_symbol::version::version(const elf_symbol::version& v)
  : priv_(new priv(v.str(), v.is_default()))
{
}

elf_symbol::version::~version() = default;

/// Cast the version_type into a string that is its name.
///
/// @return the name of the version.
elf_symbol::version::operator const string&() const
{return priv_->version_;}

/// Getter for the version name.
///
/// @return the version name.
const string&
elf_symbol::version::str() const
{return priv_->version_;}

/// Setter for the version name.
///
/// @param s the version name.
void
elf_symbol::version::str(const string& s)
{priv_->version_ = s;}

/// Getter for the 'is_default' property of the version.
///
/// @return true iff this is a default version.
bool
elf_symbol::version::is_default() const
{return priv_->is_default_;}

/// Setter for the 'is_default' property of the version.
///
/// @param f true if this is the default version.
void
elf_symbol::version::is_default(bool f)
{priv_->is_default_ = f;}

bool
elf_symbol::version::is_empty() const
{return str().empty();}

/// Compares the current version against another one.
///
/// @param o the other version to compare the current one to.
///
/// @return true iff the current version equals @p o.
bool
elf_symbol::version::operator==(const elf_symbol::version& o) const
{return str() == o.str();}

/// Inequality operator.
///
/// @param o the version to compare against the current one.
///
/// @return true iff both versions are different.
bool
elf_symbol::version::operator!=(const version& o) const
{return !operator==(o);}

/// Assign a version to the current one.
///
/// @param o the other version to assign to this one.
///
/// @return a reference to the assigned version.
elf_symbol::version&
elf_symbol::version::operator=(const elf_symbol::version& o)
{
  str(o.str());
  is_default(o.is_default());
  return *this;
}

// </elf_symbol::version stuff>

// </elf_symbol stuff>

// <class dm_context_rel stuff>
struct dm_context_rel::priv
{
  bool is_laid_out_;
  size_t offset_in_bits_;
  var_decl* anonymous_data_member_;

  priv(bool is_static = false)
    : is_laid_out_(!is_static),
      offset_in_bits_(0),
      anonymous_data_member_()
  {}

  priv(bool is_laid_out, size_t offset_in_bits)
    : is_laid_out_(is_laid_out),
      offset_in_bits_(offset_in_bits),
      anonymous_data_member_()
  {}
}; //end struct dm_context_rel::priv

dm_context_rel::dm_context_rel()
  : context_rel(),
    priv_(new priv)
{}

dm_context_rel::dm_context_rel(scope_decl* s,
                   bool is_laid_out,
                   size_t offset_in_bits,
                   access_specifier a,
                   bool is_static)
  : context_rel(s, a, is_static),
    priv_(new priv(is_laid_out, offset_in_bits))
{}

dm_context_rel::dm_context_rel(scope_decl* s)
  : context_rel(s),
    priv_(new priv())
{}

bool
dm_context_rel::get_is_laid_out() const
{return priv_->is_laid_out_;}

void
dm_context_rel::set_is_laid_out(bool f)
{priv_->is_laid_out_ = f;}

size_t
dm_context_rel::get_offset_in_bits() const
{return priv_->offset_in_bits_;}

void
dm_context_rel::set_offset_in_bits(size_t o)
{priv_->offset_in_bits_ = o;}

bool
dm_context_rel::operator==(const dm_context_rel& o) const
{
  if (!context_rel::operator==(o))
    return false;

  return (priv_->is_laid_out_ == o.priv_->is_laid_out_
        && priv_->offset_in_bits_ == o.priv_->offset_in_bits_);
}

bool
dm_context_rel::operator!=(const dm_context_rel& o) const
{return !operator==(o);}

/// Return a non-nil value if this data member context relationship
/// has an anonymous data member.  That means, if the data member this
/// relation belongs to is part of an anonymous data member.
///
/// @return the containing anonymous data member of this data member
/// relationship.  Nil if there is none.
const var_decl*
dm_context_rel::get_anonymous_data_member() const
{return priv_->anonymous_data_member_;}

/// Set the containing anonymous data member of this data member
/// context relationship. That means that the data member this
/// relation belongs to is part of an anonymous data member.
///
/// @param anon_dm the containing anonymous data member of this data
/// member relationship.  Nil if there is none.
void
dm_context_rel::set_anonymous_data_member(var_decl* anon_dm)
{priv_->anonymous_data_member_ = anon_dm;}

dm_context_rel::~dm_context_rel()
{}
// </class dm_context_rel stuff>

// <environment stuff>

/// Convenience typedef for a map of interned_string -> bool.
typedef unordered_map<interned_string,
              bool, hash_interned_string> interned_string_bool_map_type;


/// Default constructor of the @ref environment type.
environment::environment()
  :priv_(new priv)
{}

/// Destructor for the @ref environment type.
environment::~environment()
{}

/// Getter the map of canonical types.
///
/// @return the map of canonical types.  The key of the map is the
/// hash of the canonical type and its value if the canonical type.
environment::canonical_types_map_type&
environment::get_canonical_types_map()
{return priv_->canonical_types_;}

/// Getter the map of canonical types.
///
/// @return the map of canonical types.  The key of the map is the
/// hash of the canonical type and its value if the canonical type.
const environment::canonical_types_map_type&
environment::get_canonical_types_map() const
{return const_cast<environment*>(this)->get_canonical_types_map();}

/// Helper to detect if a type is either a reference, a pointer, or a
/// qualified type.
bool
is_ptr_ref_or_qual_type(const type_base *t)
{
  if (is_pointer_type(t)
      || is_reference_type(t)
      || is_qualified_type(t))
    return true;
  return false;
}

/// Compare decls using their locations.
///
/// @param f the first decl to compare.
///
/// @param s the second decl to compare.
///
/// @return true if @p f compares less than @p s.
bool
compare_using_locations(const decl_base *f,
            const decl_base *s)
{
  // If a decl has artificial location, then use that one over the
  // natural one.
  location fl = get_artificial_or_natural_location(f);
  location sl = get_artificial_or_natural_location(s);

  ABG_ASSERT(fl.get_value() && sl.get_value());
  if (fl.get_is_artificial() == sl.get_is_artificial())
    {
      // The locations of the two artfifacts have the same
      // artificial-ness so they can be compared.
      string p1, p2;
      unsigned l1 = 0, l2 = 0, c1 = 0, c2 = 0;
      fl.expand(p1, l1, c1);
      sl.expand(p2, l2, c2);
      if (p1 != p2)
    return p1 < p2;
      if (l1 != l2)
    return l1 < l2;
      if (c1 != c2)
    return c1 < c2;
    }

  return (get_pretty_representation(f, /*internal=*/false)
      < get_pretty_representation(s, /*internal=*/false));
}

/// Sort types in a hopefully stable manner.
///
/// @param types a set of types with canonical types to sort.
///
/// @param result the resulting sorted vector.
void
sort_types(const canonical_type_sptr_set_type& types,
       vector<type_base_sptr>& result)
{
  for (auto t: types)
    result.push_back(t);

  type_topo_comp comp;
  std::stable_sort(result.begin(), result.end(), comp);
}

/// Get the unique @ref type_decl that represents a "void" type for
/// the current environment.  This node must be the only one
/// representing a void type in the system.
///
/// Note that upon first use of this IR node (by the relevant
/// front-end, for instance) it must be added to a scope using e.g,
/// the @ref add_decl_to_scope() function.
///
/// @return the @ref type_decl that represents a "void" type.
const type_base_sptr&
environment::get_void_type() const
{
  if (!priv_->void_type_)
    priv_->void_type_.reset(new type_decl(*this,
                      intern("void"),
                      0, 0, location()));
  return priv_->void_type_;
}

/// Getter of the "pointer-to-void" IR node that is shared across the
/// ABI corpus.  This node must be the only one representing a void
/// pointer type in the system.
///
/// Note that upon first use of this IR node (by the relevant
/// front-end, for instance) it must be added to a scope using e.g,
/// the @ref add_decl_to_scope() function.
///
/// @return the "pointer-to-void" IR node.
const type_base_sptr&
environment::get_void_pointer_type() const
{
  if (!priv_->void_pointer_type_)
    priv_->void_pointer_type_.reset(new pointer_type_def(get_void_type(),
                             0, 0, location()));
  return priv_->void_pointer_type_;
}

/// Get a @ref type_decl instance that represents a the type of a
/// variadic function parameter. This node must be the only one
/// representing a variadic parameter type in the system.
///
/// Note that upon first use of this IR node (by the relevant
/// front-end, for instance) it must be added to a scope using e.g,
/// the @ref add_decl_to_scope() function.
///
/// @return the Get a @ref type_decl instance that represents a the
/// type of a variadic function parameter.
const type_base_sptr&
environment::get_variadic_parameter_type() const
{
  if (!priv_->variadic_marker_type_)
    priv_->variadic_marker_type_.
      reset(new type_decl(*this, intern(get_variadic_parameter_type_name()),
              0, 0, location()));
  return priv_->variadic_marker_type_;
}

/// Getter of the name of the variadic parameter type.
///
/// @return the name of the variadic parameter type.
string&
environment::get_variadic_parameter_type_name()
{
  static string variadic_parameter_type_name = "variadic parameter type";
  return variadic_parameter_type_name;
}

/// Test if the canonicalization of types created out of the current
/// environment is done.
///
/// @return true iff the canonicalization of types created out of the current
/// environment is done.
bool
environment::canonicalization_is_done() const
{return priv_->canonicalization_is_done_;}

/// Set a flag saying if the canonicalization of types created out of
/// the current environment is done or not.
///
/// Note that this function must only be called by internal code of
/// the library that creates ABI artifacts (e.g, read an abi corpus
/// from elf or from our own xml format and creates representations of
/// types out of it) and thus needs to canonicalize types to speed-up
/// further type comparison.
///
/// @param f the new value of the flag.
void
environment::canonicalization_is_done(bool f)
{
  priv_->canonicalization_is_done_ = f;
  if (priv_->canonicalization_is_done_)
    canonicalization_started(false);
}

/// Getter of a flag saying if the canonicalization process has
/// started or not.
///
/// @return the flag saying if the canonicalization process has
/// started or not.
bool
environment::canonicalization_started() const
{return priv_->canonicalization_started_;}

/// Setter of a flag saying if the canonicalization process has
/// started or not.
///
/// @param f the new value of the flag saying if the canonicalization
/// process has started or not.
void
environment::canonicalization_started(bool f)
{priv_->canonicalization_started_ = f;}

/// Getter of the "decl-only-class-equals-definition" flag.
///
/// Usually, a declaration-only class named 'struct foo' compares
/// equal to any class definition named "struct foo'.  This is at
/// least true for C++.
///
/// In C, though, because there can be multiple definitions of 'struct
/// foo' in the binary, a declaration-only "struct foo" might be
/// considered to *NOT* resolve to any of the struct foo defined.  In
/// that case, the declaration-only "struct foo" is considered
/// different from the definitions.
///
/// This flag controls the behaviour of the comparison of an
/// unresolved decl-only class against a definition of the same name.
///
/// If set to false, the the declaration equals the definition.  If
/// set to false, then the decalration is considered different from
/// the declaration.
///
/// @return the value of the "decl-only-class-equals-definition" flag.
bool
environment::decl_only_class_equals_definition() const
{return priv_->decl_only_class_equals_definition_;}

/// Setter of the "decl-only-class-equals-definition" flag.
///
/// Usually, a declaration-only class named 'struct foo' compares
/// equal to any class definition named "struct foo'.  This is at
/// least true for C++.
///
/// In C, though, because there can be multiple definitions of 'struct
/// foo' in the binary, a declaration-only "struct foo" might be
/// considered to *NOT* resolve to any of the struct foo defined.  In
/// that case, the declaration-only "struct foo" is considered
/// different from the definitions.
///
/// This flag controls the behaviour of the comparison of an
/// unresolved decl-only class against a definition of the same name.
///
/// If set to false, the the declaration equals the definition.  If
/// set to false, then the decalration is considered different from
/// the declaration.
///
/// @param the new value of the "decl-only-class-equals-definition"
/// flag.
void
environment::decl_only_class_equals_definition(bool f) const
{priv_->decl_only_class_equals_definition_ = f;}

/// Test if a given type is a void type as defined in the current
/// environment.
///
/// @param t the type to consider.
///
/// @return true iff @p t is a void type as defined in the current
/// environment.
bool
environment::is_void_type(const type_base_sptr& t) const
{
  if (!t)
    return false;
  return is_void_type(t.get());
}

/// Test if a given type is a void type as defined in the current
/// environment.
///
/// @param t the type to consider.
///
/// @return true iff @p t is a void type as defined in the current
/// environment.
bool
environment::is_void_type(const type_base* t) const
{
  if (!t)
    return false;
  return (t == get_void_type().get()
      || (is_type_decl(t) && is_type_decl(t)->get_name() == "void"));
}

/// Test if a given type is the same as the void pointer type of the
/// environment.
///
/// @param t the IR type to test.
///
/// @return true iff @p t is the void pointer returned by
/// environment::get_void_pointer_type().
bool
environment::is_void_pointer_type(const type_base_sptr& t) const
{
  if (!t)
    return false;

  return t.get() == get_void_pointer_type().get();
}

/// Test if a given type is the same as the void pointer type of the
/// environment.
///
/// @param t the IR type to test.
///
/// @return true iff @p t is the void pointer returned by
/// environment::get_void_pointer_type().
bool
environment::is_void_pointer_type(const type_base* t) const
{
  if (!t)
    return false;

  return t == get_void_pointer_type().get();
}

/// Test if a type is a variadic parameter type as defined in the
/// current environment.
///
/// @param t the type to consider.
///
/// @return true iff @p t is a variadic parameter type as defined in
/// the current environment.
bool
environment::is_variadic_parameter_type(const type_base* t) const
{
  if (!t)
    return false;
  return t == get_variadic_parameter_type().get();
}

/// Test if a type is a variadic parameter type as defined in the
/// current environment.
///
/// @param t the type to consider.
///
/// @return true iff @p t is a variadic parameter type as defined in
/// the current environment.
bool
environment::is_variadic_parameter_type(const type_base_sptr& t) const
{return is_variadic_parameter_type(t.get());}

/// Do intern a string.
///
/// If a value of this string already exists in the interned string
/// pool of the current environment, then this function returns a new
/// interned_string pointing to that already existing string.
/// Otherwise, a new string is created, stored in the interned string
/// pool and a new interned_string instance is created to point to
/// that new intrerned string, and it's return.
///
/// @param s the value of the string to intern.
///
/// @return the interned string.
interned_string
environment::intern(const string& s) const
{return const_cast<environment*>(this)->priv_->string_pool_.create_string(s);}

/// Getter of the general configuration object.
///
/// @return the configuration object.
const config&
environment::get_config() const
{return priv_->config_;}

/// Getter for a property that says if the user actually did set the
/// analyze_exported_interfaces_only() property.  If not, it means
/// the default behaviour prevails.
///
/// @return tru iff the user did set the
/// analyze_exported_interfaces_only() property.
bool
environment::user_set_analyze_exported_interfaces_only() const
{return priv_->analyze_exported_interfaces_only_.has_value();}

/// Setter for the property that controls if we are to restrict the
/// analysis to the types that are only reachable from the exported
/// interfaces only, or if the set of types should be more broad than
/// that.  Typically, we'd restrict the analysis to types reachable
/// from exported interfaces only (stricto sensu, that would really be
/// only the types that are part of the ABI of well designed
/// libraries) for performance reasons.
///
/// @param f the value of the flag.
void
environment::analyze_exported_interfaces_only(bool f)
{priv_->analyze_exported_interfaces_only_ = f;}

/// Getter for the property that controls if we are to restrict the
/// analysis to the types that are only reachable from the exported
/// interfaces only, or if the set of types should be more broad than
/// that.  Typically, we'd restrict the analysis to types reachable
/// from exported interfaces only (stricto sensu, that would really be
/// only the types that are part of the ABI of well designed
/// libraries) for performance reasons.
///
/// @param f the value of the flag.
bool
environment::analyze_exported_interfaces_only() const
{return priv_->analyze_exported_interfaces_only_.value_or(false);}

#ifdef WITH_DEBUG_SELF_COMPARISON
/// Setter of the corpus of the input corpus of the self comparison
/// that takes place when doing "abidw --debug-abidiff <binary>".
///
/// The first invocation of this function sets the first corpus of the
/// self comparison.  The second invocation of this very same function
/// sets the second corpus of the self comparison.  That second corpus
/// is supposed to come from the abixml serialization of the first
/// corpus.
///
/// @param c the corpus of the input binary or the corpus of the
/// abixml serialization of the initial binary input.
void
environment::set_self_comparison_debug_input(const corpus_sptr& c)
{
  self_comparison_debug_is_on(true);
  if (priv_->first_self_comparison_corpus_.expired())
    priv_->first_self_comparison_corpus_ = c;
  else if (priv_->second_self_comparison_corpus_.expired()
       && c.get() != corpus_sptr(priv_->first_self_comparison_corpus_).get())
    priv_->second_self_comparison_corpus_ = c;
}

/// Getter for the corpora of the input binary and the intermediate
/// abixml of the self comparison that takes place when doing
///   'abidw --debug-abidiff <binary>'.
///
/// @param first_corpus output parameter that is set to the corpus of
/// the input corpus.
///
/// @param second_corpus output parameter that is set to the corpus of
/// the second corpus.
void
environment::get_self_comparison_debug_inputs(corpus_sptr& first_corpus,
                          corpus_sptr& second_corpus)
{
    first_corpus = priv_->first_self_comparison_corpus_.lock();
    second_corpus = priv_->second_self_comparison_corpus_.lock();
}

/// Turn on/off the self comparison debug mode.
///
/// @param f true iff the self comparison debug mode is turned on.
void
environment::self_comparison_debug_is_on(bool f)
{priv_->self_comparison_debug_on_ = f;}

/// Test if we are in the process of the 'self-comparison
/// debugging' as triggered by 'abidw --debug-abidiff' command.
///
/// @return true if self comparison debug is on.
bool
environment::self_comparison_debug_is_on() const
{return priv_->self_comparison_debug_on_;}
#endif

#ifdef WITH_DEBUG_TYPE_CANONICALIZATION
/// Set the "type canonicalization debugging" mode, triggered by using
/// the command: "abidw --debug-tc".
///
/// @param flag if true then the type canonicalization debugging mode
/// is enabled.
void
environment::debug_type_canonicalization_is_on(bool flag)
{priv_->debug_type_canonicalization_ = flag;}

/// Getter of the "type canonicalization debugging" mode, triggered by
/// using the command: "abidw --debug-tc".
///
/// @return true iff the type canonicalization debugging mode is
/// enabled.
bool
environment::debug_type_canonicalization_is_on() const
{return priv_->debug_type_canonicalization_;}

/// Setter of the "DIE canonicalization debugging" mode, triggered by
/// using the command: "abidw --debug-dc".
///
/// @param flag true iff the DIE canonicalization debugging mode is
/// enabled.
void
environment::debug_die_canonicalization_is_on(bool flag)
{priv_->debug_die_canonicalization_ = flag;}

/// Getter of the "DIE canonicalization debugging" mode, triggered by
/// using the command: "abidw --debug-dc".
///
/// @return true iff the DIE canonicalization debugging mode is
/// enabled.
bool
environment::debug_die_canonicalization_is_on() const
{return priv_->debug_die_canonicalization_;}
#endif // WITH_DEBUG_TYPE_CANONICALIZATION

/// Get the vector of canonical types which have a given "string
/// representation".
///
/// @param 'name', the textual representation of the type as returned
/// by type_or_decl_base::get_pretty_representation(/*internal=*/true,
///                                                 /*qualified=*/true)
///
/// This is useful to for debugging purposes as it's handy to use from
/// inside a debugger like GDB.
///
/// @return a pointer to the vector of canonical types having the
/// representation @p name, or nullptr if no type with that
/// representation exists.
const vector<type_base_sptr>*
environment::get_canonical_types(const char* name) const
{
  auto ti = get_canonical_types_map().find(name);
  if (ti == get_canonical_types_map().end())
    return nullptr;
  return &ti->second;
}

/// Get a given canonical type which has a given "string
/// representation".
///
/// @param 'name', the textual representation of the type as returned
/// by type_or_decl_base::get_pretty_representation(/*internal=*/true,
///                                                 /*qualified=*/true).
///
/// @param index, the index of the type in the vector of types that
/// all have the same textual representation @p 'name'.  That vector
/// is returned by the function environment::get_canonical_types().
///
/// @return the canonical type which has the representation @p name,
/// and which is at index @p index in the vector of canonical types
/// having that same textual representation.
type_base*
environment::get_canonical_type(const char* name, unsigned index)
{
  const vector<type_base_sptr> *types = get_canonical_types(name);
  if (!types ||index >= types->size())
    return nullptr;
  return (*types)[index].get();
}

#ifdef WITH_DEBUG_SELF_COMPARISON
/// Get the set of abixml type-id and the pointer value of the
/// (canonical) type it's associated to.
///
/// This is useful for debugging purposes, especially in the context
/// of the use of the command:
///   'abidw --debug-abidiff <binary>'.
///
/// @return the set of abixml type-id and the pointer value of the
/// (canonical) type it's associated to.
const unordered_map<string, uintptr_t>&
environment::get_type_id_canonical_type_map() const
{return priv_->get_type_id_canonical_type_map();}

/// Get the set of abixml type-id and the pointer value of the
/// (canonical) type it's associated to.
///
/// This is useful for debugging purposes, especially in the context
/// of the use of the command:
///   'abidw --debug-abidiff <binary>'.
///
/// @return the set of abixml type-id and the pointer value of the
/// (canonical) type it's associated to.
unordered_map<string, uintptr_t>&
environment::get_type_id_canonical_type_map()
{return priv_->get_type_id_canonical_type_map();}

/// Getter of the map that associates the values of type pointers to
/// their type-id strings.
///
/// Note that this map is populated at abixml reading time, (by
/// build_type()) when a given XML element representing a type is
/// read into a corresponding abigail::ir::type_base.
///
/// This is used only for the purpose of debugging the
/// self-comparison process.  That is, when invoking "abidw
/// --debug-abidiff".
///
/// @return the map that associates the values of type pointers to
/// their type-id strings.
const unordered_map<uintptr_t, string>&
environment::get_pointer_type_id_map() const
{return priv_->get_pointer_type_id_map();}

/// Getter of the map that associates the values of type pointers to
/// their type-id strings.
///
/// Note that this map is populated at abixml reading time, (by
/// build_type()) when a given XML element representing a type is
/// read into a corresponding abigail::ir::type_base.
///
/// This is used only for the purpose of debugging the
/// self-comparison process.  That is, when invoking "abidw
/// --debug-abidiff".
///
/// @return the map that associates the values of type pointers to
/// their type-id strings.
unordered_map<uintptr_t, string>&
environment::get_pointer_type_id_map()
{return priv_->get_pointer_type_id_map();}

/// Getter of the type-id that corresponds to the value of a pointer
/// to abigail::ir::type_base that was created from the abixml reader.
///
/// That value is retrieved from the map returned from
/// environment::get_pointer_type_id_map().
///
/// That map is populated at abixml reading time, (by build_type())
/// when a given XML element representing a type is read into a
/// corresponding abigail::ir::type_base.
///
/// This is used only for the purpose of debugging the
/// self-comparison process.  That is, when invoking "abidw
/// --debug-abidiff".
///
/// @return the type-id strings that corresponds
string
environment::get_type_id_from_pointer(uintptr_t ptr) const
{return priv_->get_type_id_from_pointer(ptr);}

/// Getter of the type-id that corresponds to the value of an
/// abigail::ir::type_base that was created from the abixml reader.
///
/// That value is retrieved from the map returned from
/// environment::get_pointer_type_id_map().
///
/// That map is populated at abixml reading time, (by build_type())
/// when a given XML element representing a type is read into a
/// corresponding abigail::ir::type_base.
///
/// This is used only for the purpose of debugging the
/// self-comparison process.  That is, when invoking "abidw
/// --debug-abidiff".
///
/// @return the type-id strings that corresponds
string
environment::get_type_id_from_type(const type_base *t) const
{return priv_->get_type_id_from_type(t);}

/// Getter of the canonical type of the artifact designated by a
/// type-id.
///
/// That type-id was generated by the abixml writer at the emitting
/// time of the abixml file.  The corresponding canonical type was
/// stored in the map returned by
/// environment::get_type_id_canonical_type_map().
///
/// This is useful for debugging purposes, especially in the context
/// of the use of the command:
///   'abidw --debug-abidiff <binary>'.
///
/// @return the set of abixml type-id and the pointer value of the
/// (canonical) type it's associated to.
uintptr_t
environment::get_canonical_type_from_type_id(const char* type_id) const
{return priv_->get_canonical_type_from_type_id(type_id);}
#endif

// </environment stuff>

// <type_or_decl_base stuff>

/// bitwise "OR" operator for the type_or_decl_base::type_or_decl_kind
/// bitmap type.
type_or_decl_base::type_or_decl_kind
operator|(type_or_decl_base::type_or_decl_kind l,
      type_or_decl_base::type_or_decl_kind r)
{
  return static_cast<type_or_decl_base::type_or_decl_kind>
    (static_cast<unsigned>(l) | static_cast<unsigned>(r));
}

/// bitwise "|=" operator for the type_or_decl_base::type_or_decl_kind
/// bitmap type.
type_or_decl_base::type_or_decl_kind&
operator|=(type_or_decl_base::type_or_decl_kind& l,
       type_or_decl_base::type_or_decl_kind r)
{
  l = l | r;
  return l;
}

/// bitwise "AND" operator for the
/// type_or_decl_base::type_or_decl_kind bitmap type.
type_or_decl_base::type_or_decl_kind
operator&(type_or_decl_base::type_or_decl_kind l,
      type_or_decl_base::type_or_decl_kind r)
{
  return static_cast<type_or_decl_base::type_or_decl_kind>
    (static_cast<unsigned>(l) & static_cast<unsigned>(r));
}

/// bitwise "A&=" operator for the
/// type_or_decl_base::type_or_decl_kind bitmap type.
type_or_decl_base::type_or_decl_kind&
operator&=(type_or_decl_base::type_or_decl_kind& l,
      type_or_decl_base::type_or_decl_kind r)
{
  l = l & r;
  return l;
}

/// Constructor of @ref type_or_decl_base.
///
/// @param the environment the current ABI artifact is constructed
/// from.
///
/// @param k the runtime identifier bitmap of the type being built.
type_or_decl_base::type_or_decl_base(const environment& e,
                     enum type_or_decl_kind k)
  :priv_(new priv(e, k))
{}

/// The destructor of the @ref type_or_decl_base type.
type_or_decl_base::~type_or_decl_base()
{}

/// Getter of the flag that says if the artefact is artificial.
///
/// Being artificial means it was not explicitely mentionned in the
/// source code, but was rather artificially created by the compiler
/// or libabigail.
///
/// @return true iff the declaration is artificial.
bool
type_or_decl_base::get_is_artificial() const
{return priv_->is_artificial_;}

/// Setter of the flag that says if the artefact is artificial.
///
/// Being artificial means the artefact was not explicitely
/// mentionned in the source code, but was rather artificially created
/// by the compiler or by libabigail.
///
/// @param f the new value of the flag that says if the artefact is
/// artificial.
void
type_or_decl_base::set_is_artificial(bool f)
{priv_->is_artificial_ = f;}

/// Getter for the "kind" property of @ref type_or_decl_base type.
///
/// This property holds the identifier bitmap of the runtime type of
/// an ABI artifact.
///
/// @return the runtime type identifier bitmap of the current ABI
/// artifact.
enum type_or_decl_base::type_or_decl_kind
type_or_decl_base::kind() const
{return priv_->kind();}

/// Setter for the "kind" property of @ref type_or_decl_base type.
///
/// This property holds the identifier bitmap of the runtime type of
/// an ABI artifact.
///
/// @param the runtime type identifier bitmap of the current ABI
/// artifact.
void
type_or_decl_base::kind(enum type_or_decl_kind k)
{priv_->kind(k);}

/// Getter of the pointer to the runtime type sub-object of the
/// current instance.
///
/// @return the pointer to the runtime type sub-object of the current
/// instance.
const void*
type_or_decl_base::runtime_type_instance() const
{return priv_->rtti_;}

/// Getter of the pointer to the runtime type sub-object of the
/// current instance.
///
/// @return the pointer to the runtime type sub-object of the current
/// instance.
void*
type_or_decl_base::runtime_type_instance()
{return priv_->rtti_;}

/// Setter of the pointer to the runtime type sub-object of the
/// current instance.
///
/// @param i the new pointer to the runtime type sub-object of the
/// current instance.
void
type_or_decl_base::runtime_type_instance(void* i)
{
  priv_->rtti_ = i;
  if (type_base* t = dynamic_cast<type_base*>(this))
    priv_->type_or_decl_ptr_ = t;
  else if (decl_base *d = dynamic_cast<decl_base*>(this))
    priv_->type_or_decl_ptr_ = d;
}

/// Getter of the pointer to either the type_base sub-object of the
/// current instance if it's a type, or to the decl_base sub-object of
/// the current instance if it's a decl.
///
/// @return the pointer to either the type_base sub-object of the
/// current instance if it's a type, or to the decl_base sub-object of
/// the current instance if it's a decl.
const void*
type_or_decl_base::type_or_decl_base_pointer() const
{return const_cast<type_or_decl_base*>(this)->type_or_decl_base_pointer();}

/// Getter of the pointer to either the type_base sub-object of the
/// current instance if it's a type, or to the decl_base sub-object of
/// the current instance if it's a decl.
///
/// @return the pointer to either the type_base sub-object of the
/// current instance if it's a type, or to the decl_base sub-object of
/// the current instance if it's a decl.
void*
type_or_decl_base::type_or_decl_base_pointer()
{return priv_->type_or_decl_ptr_;}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
type_or_decl_base::hash_value() const
{return priv_->hash_value_;}

void
type_or_decl_base::set_hash_value(hash_t h) const
{priv_->set_hash_value(h);}

/// Getter of the environment of the current ABI artifact.
///
/// @return the environment of the artifact.
const environment&
type_or_decl_base::get_environment() const
{return priv_->env_;}

/// Setter of the artificial location of the artificat.
///
/// The artificial location is a location that was artificially
/// generated by libabigail, not generated by the original emitter of
/// the ABI meta-data.  For instance, when reading an XML element from
/// an abixml file, the artificial location is the source location of
/// the XML element within the file, not the value of the
/// 'location'property that might be carried by the element.
///
/// Artificial locations might be useful to ensure that abixml emitted
/// by the abixml writer are sorted the same way as the input abixml
/// read by the reader.
///
/// @param l the new artificial location.
void
type_or_decl_base::set_artificial_location(const location &l)
{priv_->artificial_location_ = l;}

/// Getter of the artificial location of the artifact.
///
/// The artificial location is a location that was artificially
/// generated by libabigail, not generated by the original emitter of
/// the ABI meta-data.  For instance, when reading an XML element from
/// an abixml file, the artificial location is the source location of
/// the XML element within the file, not the value of the
/// 'location'property that might be carried by the element.
///
/// Artificial locations might be useful to ensure that the abixml
/// emitted by the abixml writer is sorted the same way as the input
/// abixml read by the reader.
///
/// @return the new artificial location.
location&
type_or_decl_base::get_artificial_location() const
{return priv_->artificial_location_;}

/// Test if the current ABI artifact carries an artificial location.
///
/// @return true iff the current ABI artifact carries an artificial location.
bool
type_or_decl_base::has_artificial_location() const
{
  return (priv_->artificial_location_
      && priv_->artificial_location_.get_is_artificial());
}

/// Get the @ref corpus this ABI artifact belongs to.
///
/// @return the corpus this ABI artifact belongs to, or nil if it
/// belongs to none for now.
corpus*
type_or_decl_base::get_corpus()
{
  translation_unit* tu = abigail::ir::get_translation_unit(this);
  if (!tu)
    return 0;
  return tu->get_corpus();
}


/// Get the @ref corpus this ABI artifact belongs to.
///
/// @return the corpus this ABI artifact belongs to, or nil if it
/// belongs to none for now.
const corpus*
type_or_decl_base::get_corpus() const
{return const_cast<type_or_decl_base*>(this)->get_corpus();}

/// Set the @ref translation_unit this ABI artifact belongs to.
///
/// Note that adding an ABI artifact to a containining on should
/// invoke this member function.
void
type_or_decl_base::set_translation_unit(translation_unit* tu)
{priv_->translation_unit_ = tu;}


/// Get the @ref translation_unit this ABI artifact belongs to.
///
/// @return the translation unit this ABI artifact belongs to, or nil
/// if belongs to none for now.
translation_unit*
type_or_decl_base::get_translation_unit()
{return priv_->translation_unit_;}

/// Get the @ref translation_unit this ABI artifact belongs to.
///
/// @return the translation unit this ABI artifact belongs to, or nil
/// if belongs to none for now.
const translation_unit*
type_or_decl_base::get_translation_unit() const
{return const_cast<type_or_decl_base*>(this)->get_translation_unit();}

/// Traverse the the ABI artifact.
///
/// @param v the visitor used to traverse the sub-tree nodes of the
/// artifact.
bool
type_or_decl_base::traverse(ir_node_visitor&)
{return true;}

/// Non-member equality operator for the @type_or_decl_base type.
///
/// @param lr the left-hand operand of the equality.
///
/// @param rr the right-hand operatnr of the equality.
///
/// @return true iff @p lr equals @p rr.
bool
operator==(const type_or_decl_base& lr, const type_or_decl_base& rr)
{
  const type_or_decl_base* l = &lr;
  const type_or_decl_base* r = &rr;

  const decl_base* dl = dynamic_cast<const decl_base*>(l),
    *dr = dynamic_cast<const decl_base*>(r);

  if (!!dl != !!dr)
    return false;

  if (dl && dr)
    return *dl == *dr;

  const type_base* tl = dynamic_cast<const type_base*>(l),
    *tr = dynamic_cast<const type_base*>(r);

  if (!!tl != !!tr)
    return false;

  if (tl && tr)
    return *tl == *tr;

  return false;
}

/// Non-member equality operator for the @type_or_decl_base type.
///
/// @param l the left-hand operand of the equality.
///
/// @param r the right-hand operatnr of the equality.
///
/// @return true iff @p l equals @p r.
bool
operator==(const type_or_decl_base_sptr& l, const type_or_decl_base_sptr& r)
{
  if (!! l != !!r)
    return false;

  if (!l)
    return true;

  return *r == *l;
}

/// Non-member inequality operator for the @type_or_decl_base type.
///
/// @param l the left-hand operand of the equality.
///
/// @param r the right-hand operator of the equality.
///
/// @return true iff @p l is different from @p r.
bool
operator!=(const type_or_decl_base_sptr& l, const type_or_decl_base_sptr& r)
{return !operator==(l, r);}

// </type_or_decl_base stuff>

// <Decl definition>

struct decl_base::priv
{
  bool          in_pub_sym_tab_;
  bool          is_anonymous_;
  location      location_;
  context_rel       *context_;
  interned_string   name_;
  interned_string   qualified_parent_name_;
  // This temporary qualified name is the cache used for the qualified
  // name before the type associated to this decl (if applicable) is
  // canonicalized.  Once the type is canonicalized, the cached use is
  // the data member qualified_parent_name_ above.
  interned_string   temporary_qualified_name_;
  // This is the fully qualified name of the decl.  It contains the
  // name of the decl and the qualified name of its scope.  So if in
  // the parent scopes of the decl, there is one anonymous struct,
  // somewhere in the name, there is going to by an
  // __anonymous_struct__ string, even if the anonymous struct is not
  // the direct containing scope of this decl.
  interned_string   qualified_name_;
  interned_string   temporary_internal_qualified_name_;
  interned_string   internal_qualified_name_;
  interned_string   internal_cached_repr_;
  interned_string   cached_repr_;
  // Unline qualified_name_, scoped_name_ contains the name of the
  // decl and the name of its scope; not the qualified name of the
  // scope.
  interned_string   scoped_name_;
  interned_string   linkage_name_;
  visibility        visibility_;
  decl_base_sptr    declaration_;
  decl_base_wptr    definition_of_declaration_;
  decl_base*        naked_definition_of_declaration_;
  bool          is_declaration_only_;
  typedef_decl_sptr naming_typedef_;

  priv()
    : in_pub_sym_tab_(false),
      is_anonymous_(true),
      context_(),
      visibility_(VISIBILITY_DEFAULT),
      naked_definition_of_declaration_(),
      is_declaration_only_(false)
  {}

  priv(interned_string name, interned_string linkage_name, visibility vis)
    : in_pub_sym_tab_(false),
      context_(),
      name_(name),
      qualified_name_(name),
      linkage_name_(linkage_name),
      visibility_(vis),
      naked_definition_of_declaration_(),
      is_declaration_only_(false)
  {
    is_anonymous_ = name_.empty();
  }

  ~priv()
  {
    delete context_;
  }
};// end struct decl_base::priv

/// Constructor for the @ref decl_base type.
///
/// @param e the environment the current @ref decl_base is being
/// created in.
///
/// @param name the name of the declaration.
///
/// @param locus the location where to find the declaration in the
/// source code.
///
/// @param linkage_name the linkage name of the declaration.
///
/// @param vis the visibility of the declaration.
decl_base::decl_base(const environment& e,
             const string&  name,
             const location&    locus,
             const string&  linkage_name,
             visibility vis)
  : type_or_decl_base(e, ABSTRACT_DECL_BASE),
    priv_(new priv(e.intern(name), e.intern(linkage_name), vis))
{
  set_location(locus);
}

/// Constructor.
///
/// @param e the environment this instance of @ref decl_base is
/// created in.
///
/// @param name the name of the declaration being constructed.
///
/// @param locus the source location of the declaration being constructed.
///
/// @param linkage_name the linkage name of the declaration being
/// constructed.
///
/// @param vis the visibility of the declaration being constructed.
decl_base::decl_base(const environment& e,
             const interned_string& name,
             const location& locus,
             const interned_string& linkage_name,
             visibility vis)
  : type_or_decl_base(e, ABSTRACT_DECL_BASE),
    priv_(new priv(name, linkage_name, vis))
{
  set_location(locus);
}

/// Constructor for the @ref decl_base type.
///
///@param environment the environment this instance of @ref decl_base
/// is being constructed in.
///
/// @param l the location where to find the declaration in the source
/// code.
decl_base::decl_base(const environment& e, const location& l)
  : type_or_decl_base(e, ABSTRACT_DECL_BASE),
    priv_(new priv())
{
  set_location(l);
}

/// Getter for the qualified name.
///
/// Unlike decl_base::get_qualified_name() this doesn't try to update
/// the qualified name.
///
/// @return the qualified name.
const interned_string&
decl_base::peek_qualified_name() const
{return priv_->qualified_name_;}

/// Clear the qualified name of this decl.
///
/// This is useful to ensure that the cache for the qualified name of
/// the decl is refreshed right after type canonicalization, for
/// instance.
void
decl_base::clear_qualified_name()
{priv_->qualified_name_.clear();}

/// Setter for the qualified name.
///
/// @param n the new qualified name.
void
decl_base::set_qualified_name(const interned_string& n) const
{priv_->qualified_name_ = n;}

/// Getter of the temporary qualified name of the current declaration.
///
/// This temporary qualified name is used as a qualified name cache by
/// the type for which this is the declaration (when applicable)
/// before the type is canonicalized.  Once the type is canonicalized,
/// it's the result of decl_base::peek_qualified_name() that becomes
/// the qualified name cached.
///
/// @return the temporary qualified name.
const interned_string&
decl_base::peek_temporary_qualified_name() const
{return priv_->temporary_qualified_name_;}

/// Setter for the temporary qualified name of the current
/// declaration.
///
///@param n the new temporary qualified name.
///
/// This temporary qualified name is used as a qualified name cache by
/// the type for which this is the declaration (when applicable)
/// before the type is canonicalized.  Once the type is canonicalized,
/// it's the result of decl_base::peek_qualified_name() that becomes
/// the qualified name cached.
void
decl_base::set_temporary_qualified_name(const interned_string& n) const
{priv_->temporary_qualified_name_ = n;}

///Getter for the context relationship.
///
///@return the context relationship for the current decl_base.
const context_rel*
decl_base::get_context_rel() const
{return priv_->context_;}

///Getter for the context relationship.
///
///@return the context relationship for the current decl_base.
context_rel*
decl_base::get_context_rel()
{return priv_->context_;}

void
decl_base::set_context_rel(context_rel *c)
{priv_->context_ = c;}

/// Test if the decl is defined in a ELF symbol table as a public
/// symbol.
///
/// @return true iff the decl is defined in a ELF symbol table as a
/// public symbol.
bool
decl_base::get_is_in_public_symbol_table() const
{return priv_->in_pub_sym_tab_;}

/// Set the flag saying if this decl is from a symbol that is in
/// a public symbols table, defined as public (global or weak).
///
/// @param f the new flag value.
void
decl_base::set_is_in_public_symbol_table(bool f)
{priv_->in_pub_sym_tab_ = f;}

/// Get the location of a given declaration.
///
/// The location is an abstraction for the tripplet {file path,
/// line, column} that defines where the declaration appeared in the
/// source code.
///
/// To get the value of the tripplet {file path, line, column} from
/// the @ref location, you need to use the
/// location_manager::expand_location() method.
///
/// The instance of @ref location_manager that you want is
/// accessible from the instance of @ref translation_unit that the
/// current instance of @ref decl_base belongs to, via a call to
/// translation_unit::get_loc_mgr().
///
/// @return the location of the current instance of @ref decl_base.
const location&
decl_base::get_location() const
{return priv_->location_;}

/// Set the location for a given declaration.
///
/// The location is an abstraction for the tripplet {file path,
/// line, column} that defines where the declaration appeared in the
/// source code.
///
/// To create a location from a tripplet {file path, line, column},
/// you need to use the method @ref
/// location_manager::create_new_location().
///
/// Note that there can be two kinds of location.  An artificial
/// location and a non-artificial one.  The non-artificial location is
/// the one emitted by the original emitter of the ABI artifact, for
/// instance, if the ABI artifact comes from debug info, then the
/// source location that is present in the debug info represent a
/// non-artificial location.  When looking at an abixml file on the
/// other hand, the value of the 'location' attribute of an XML
/// element describing an artifact is the non-artificial location.
/// The artificial location is the location (line number from the
/// beginning of the file) of the XML element within the abixml file.
///
/// So, if the location that is being set is artificial, note that the
/// type_or_decl_base::has_artificial_location() method of this decl will
/// subsequently return true and that artificial location will have to
/// be retrieved using type_or_decl_base::get_artificial_location().
/// If the location is non-artificial however,
/// type_or_decl_base::has_artificial_location() will subsequently
/// return false and the non-artificial location will have to be
/// retrieved using decl_base::get_location().
///
/// The instance of @ref location_manager that you want is
/// accessible from the instance of @ref translation_unit that the
/// current instance of @ref decl_base belongs to, via a call to
/// translation_unit::get_loc_mgr().
void
decl_base::set_location(const location& l)
{
  if (l.get_is_artificial())
    set_artificial_location(l);
  else
    priv_->location_ = l;
}

/// Setter for the name of the decl.
///
/// @param n the new name to set.
void
decl_base::set_name(const string& n)
{
  priv_->name_ = get_environment().intern(n);
  priv_->is_anonymous_ = n.empty();
}

/// Test if the current declaration is anonymous.
///
/// Being anonymous means that the declaration was created without a
/// name.  This can usually happen for enum or struct types.
///
/// @return true iff the type is anonymous.
bool
decl_base::get_is_anonymous() const
{return priv_->is_anonymous_;}

/// Set the "is_anonymous" flag of the current declaration.
///
/// Being anonymous means that the declaration was created without a
/// name.  This can usually happen for enum or struct types.
///
/// @param f the new value of the flag.
void
decl_base::set_is_anonymous(bool f)
{priv_->is_anonymous_ = f;}


/// Get the "has_anonymous_parent" flag of the current declaration.
///
/// Having an anoymous parent means having a anonymous parent scope
/// (containing type or namespace) which is either direct or indirect.
///
/// @return true iff the current decl has a direct or indirect scope
/// which is anonymous.
bool
decl_base::get_has_anonymous_parent() const
{
  scope_decl *scope = get_scope();
  if (!scope)
    return false;
  return scope->get_is_anonymous();
}

/// @return the logical "OR" of decl_base::get_is_anonymous() and
/// decl_base::get_has_anonymous_parent().
bool
decl_base::get_is_anonymous_or_has_anonymous_parent() const
{return get_is_anonymous() || get_has_anonymous_parent();}

/// Getter for the naming typedef of the current decl.
///
/// Consider the C idiom:
///
///    typedef struct {int member;} foo_type;
///
/// In that idiom, foo_type is the naming typedef of the anonymous
/// struct that is declared.
///
/// @return the naming typedef, if any.  Otherwise, returns nil.
typedef_decl_sptr
decl_base::get_naming_typedef() const
{return priv_->naming_typedef_;}

/// Set the naming typedef of the current instance of @ref decl_base.
///
/// Consider the C idiom:
///
///    typedef struct {int member;} foo_type;
///
/// In that idiom, foo_type is the naming typedef of the anonymous
/// struct that is declared.
///
/// After completion of this function, the decl will not be considered
/// anonymous anymore.  It's name is going to be the name of the
/// naming typedef.
///
/// @param typedef_type the new naming typedef.
void
decl_base::set_naming_typedef(const typedef_decl_sptr& t)
{
  // A naming typedef is usually for an anonymous type.
  ABG_ASSERT(get_is_anonymous()
         // Whe the typedef-named decl is saved into abixml, it's
         // not anonymous anymore.  Its name is the typedef name.
         // So when we read it back, we must still be able to
         // apply the naming typedef to the decl.
         || t->get_name() == get_name());
  // Only non canonicalized types can be edited this way.
  ABG_ASSERT(is_type(this)
         && is_type(this)->get_naked_canonical_type() == nullptr);

  priv_->naming_typedef_ = t;
  set_name(t->get_name());
  string qualified_name = build_qualified_name(get_scope(), t->get_name());
  set_qualified_name(get_environment().intern(qualified_name));
  set_is_anonymous(false);
  // Now that the qualified type of the decl has changed, let's update
  // the qualified names of the member types of this decls.
  update_qualified_name(this);
}

/// Getter for the mangled name.
///
/// @return the new mangled name.
const interned_string&
decl_base::get_linkage_name() const
{return priv_->linkage_name_;}

/// Setter for the linkage name.
///
/// @param m the new linkage name.
void
decl_base::set_linkage_name(const string& m)
{
  const environment& env = get_environment();
  priv_->linkage_name_ = env.intern(m);
}

/// Getter for the visibility of the decl.
///
/// @return the new visibility.
decl_base::visibility
decl_base::get_visibility() const
{return priv_->visibility_;}

/// Setter for the visibility of the decl.
///
/// @param v the new visibility.
void
decl_base::set_visibility(visibility v)
{priv_->visibility_ = v;}

/// Return the type containing the current decl, if any.
///
/// @return the type that contains the current decl, or NULL if there
/// is none.
scope_decl*
decl_base::get_scope() const
{
  if (priv_->context_)
    return priv_->context_->get_scope();
  return 0;
}

/// Return a copy of the qualified name of the parent of the current
/// decl.
///
/// @return the newly-built qualified name of the of the current decl.
const interned_string&
decl_base::get_qualified_parent_name() const
{return priv_->qualified_parent_name_;}

/// Getter for the name of the current decl.
///
/// @return the name of the current decl.
const interned_string&
decl_base::get_name() const
{return priv_->name_;}

/// Compute the qualified name of the decl.
///
/// @param qn the resulting qualified name.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
void
decl_base::get_qualified_name(interned_string& qn, bool internal) const
{qn = get_qualified_name(internal);}

/// Get the pretty representatin of the current declaration.
///
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
///
/// @param qualified_name if true, names emitted in the pretty
/// representation are fully qualified.
///
/// @return the default pretty representation for a decl.  This is
/// basically the fully qualified name of the decl optionally prefixed
/// with a meaningful string to add context for the user.
string
decl_base::get_pretty_representation(bool internal,
                     bool qualified_name) const
{
  if (internal
      && get_is_anonymous()
      && has_generic_anonymous_internal_type_name(this))
    {
      // We are looking at an anonymous enum, union or class and we
      // want an *internal* pretty representation for it.  All
      // anonymous types of this kind in the same namespace must have
      // the same internal representation for type canonicalization to
      // work properly.
      //
      // OK, in practise, we are certainly looking at an enum because
      // classes and unions should have their own overloaded virtual
      // member function for this.
      string name = get_generic_anonymous_internal_type_name(this);
      if (qualified_name && !get_qualified_parent_name().empty())
    name = get_qualified_parent_name() + "::" + name;
      return name;
    }

  if (qualified_name)
    return get_qualified_name(internal);
  return get_name();
}

/// Get the pretty representation of the current decl.
///
/// The pretty representation is retrieved from a cache.  If the cache
/// is empty, this function computes the pretty representation, put it
/// in the cache and returns it.
///
/// Please note that if this function is called too early in the life
/// cycle of the decl (before it is fully constructed), then the
/// pretty representation that is cached is going to represent a
/// non-complete (and thus wrong) representation of the decl.  Thus
/// this function must be called only once the decl is fully
/// constructed.
///
/// @param internal if true, then the pretty representation is to be
/// used for purpuses that are internal to the libabigail library
/// itself.  If you don't know what this means, then you probably
/// should set this parameter to "false".
///
/// @return a reference to a cached @ref interned_string holding the
/// pretty representation of the current decl.
const interned_string&
decl_base::get_cached_pretty_representation(bool internal) const
{
    if (internal)
    {
      if (priv_->internal_cached_repr_.empty())
    {
      string r = ir::get_pretty_representation(this, internal);
      priv_->internal_cached_repr_ = get_environment().intern(r);
    }
      return priv_->internal_cached_repr_;
    }

  if (priv_->cached_repr_.empty())
    {
      string r = ir::get_pretty_representation(this, internal);
      priv_->cached_repr_ = get_environment().intern(r);
    }

  return priv_->cached_repr_;
}

/// Return the qualified name of the decl.
///
/// This is the fully qualified name of the decl.  It's made of the
/// concatenation of the name of the decl with the qualified name of
/// its scope.
///
/// Note that the value returned by this function is computed by @ref
/// update_qualified_name when the decl is added to its scope.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the resulting qualified name.
const interned_string&
decl_base::get_qualified_name(bool /*internal*/) const
{return priv_->qualified_name_;}

/// Return the scoped name of the decl.
///
/// This is made of the concatenation of the name of the decl with the
/// name of its scope.  It doesn't contain the qualified name of its
/// scope, unlike what is returned by decl_base::get_qualified_name.
///
/// Note that the value returned by this function is computed by @ref
/// update_qualified_name when the decl is added to its scope.
///
/// @return the scoped name of the decl.
const interned_string&
decl_base::get_scoped_name() const
{return priv_->scoped_name_;}

/// If this @ref decl_base is a definition, get its earlier
/// declaration.
///
/// @return the earlier declaration of the class, if any.
const decl_base_sptr
decl_base::get_earlier_declaration() const
{return priv_->declaration_;}

/// set the earlier declaration of this @ref decl_base definition.
///
/// @param d the earlier declaration to set.  Note that it's set only
/// if it's a pure declaration.
void
decl_base::set_earlier_declaration(const decl_base_sptr& d)
{
  if (d && d->get_is_declaration_only())
    priv_->declaration_ = d;
}


/// If this @ref decl_base is declaration-only, get its definition, if
/// any.
///
/// @return the definition of this decl-only @ref decl_base.
const decl_base_sptr
decl_base::get_definition_of_declaration() const
{return priv_->definition_of_declaration_.lock();}

///  If this @ref decl_base is declaration-only, get its definition,
///  if any.
///
/// Note that this function doesn't return a smart pointer, but rather
/// the underlying pointer managed by the smart pointer.  So it's as
/// fast as possible.  This getter is to be used in code paths that
/// are proven to be performance hot spots; especially, when comparing
/// sensitive types like enums, classes or unions.  Those are compared
/// extremely frequently and thus, their access to the definition of
/// declaration must be fast.
///
/// @return the definition of the declaration.
const decl_base*
decl_base::get_naked_definition_of_declaration() const
{return priv_->naked_definition_of_declaration_;}

/// Test if a @ref decl_base is a declaration-only decl.
///
/// @return true iff the current @ref decl_base is declaration-only.
bool
decl_base::get_is_declaration_only() const
{return priv_->is_declaration_only_;}

/// Set a flag saying if the @ref enum_type_decl is a declaration-only
/// @ref enum_type_decl.
///
/// @param f true if the @ref enum_type_decl is a declaration-only
/// @ref enum_type_decl.
void
decl_base::set_is_declaration_only(bool f)
{
  bool update_types_lookup_map = !f && priv_->is_declaration_only_;

  priv_->is_declaration_only_ = f;

  if (update_types_lookup_map)
    if (scope_decl* s = get_scope())
      {
    scope_decl::declarations::iterator i;
    if (s->find_iterator_for_member(this, i))
      maybe_update_types_lookup_map(*i);
    else
      ABG_ASSERT_NOT_REACHED;
      }
}

change_kind
operator|(change_kind l, change_kind r)
{
  return static_cast<change_kind>(static_cast<unsigned>(l)
                  | static_cast<unsigned>(r));
}

change_kind
operator&(change_kind l, change_kind r)
{
  return static_cast<change_kind>(static_cast<unsigned>(l)
                  & static_cast<unsigned>(r));
}

change_kind&
operator|=(change_kind& l, change_kind r)
{
  l = l | r;
  return l;
}

change_kind&
operator&=(change_kind& l, change_kind r)
{
  l = l & r;
  return l;
}

/// Compare the properties that belong to the "is-a-member-relation"
/// of a decl.
///
/// For instance, access specifiers are part of the
/// "is-a-member-relation" of a decl.
///
/// This comparison however doesn't take decl names into account.  So
/// typedefs for instance are decls that we want to compare with this
/// function.
///
/// This function is a sub-routine of the more general 'equals'
/// overload for instances of decl_base.
///
/// @param l the left-hand side operand of the comparison.
///
/// @param r the right-hand side operand of the comparison.
///
/// @return true iff @p l compare equals, as a member decl, to @p r.
bool
maybe_compare_as_member_decls(const decl_base& l,
                  const decl_base& r,
                  change_kind* k)
{
  bool result = true;
  if (is_member_decl(l) && is_member_decl(r))
    {
      context_rel* r1 = const_cast<context_rel*>(l.get_context_rel());
      context_rel *r2 = const_cast<context_rel*>(r.get_context_rel());

      access_specifier la = no_access, ra = no_access;
      bool member_types_or_functions =
    ((is_type(l) && is_type(r))
     || (is_function_decl(l) && is_function_decl(r)));

      if (member_types_or_functions)
    {
      // Access specifiers on member types in DWARF is not
      // reliable; in the same DSO, the same struct can be either
      // a class or a struct, and the access specifiers of its
      // member types are not necessarily given, so they
      // effectively can be considered differently, again, in the
      // same DSO.  So, here, let's avoid considering those!
      // during comparison.
      la = r1->get_access_specifier();
      ra = r2->get_access_specifier();
      r1->set_access_specifier(no_access);
      r2->set_access_specifier(no_access);
    }

      bool rels_are_different = *r1 != *r2;

      if (member_types_or_functions)
    {
      // restore the access specifiers.
      r1->set_access_specifier(la);
      r2->set_access_specifier(ra);
    }

      if (rels_are_different)
    {
      result = false;
      if (k)
        *k |= LOCAL_NON_TYPE_CHANGE_KIND;
    }
    }
  ABG_RETURN(result);
}

/// Compares two instances of @ref decl_base.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff it's non-null and if the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const decl_base& l, const decl_base& r, change_kind* k)
{
  bool result = true;
  const interned_string &l_linkage_name = l.get_linkage_name();
  const interned_string &r_linkage_name = r.get_linkage_name();
  if (!l_linkage_name.empty() && !r_linkage_name.empty())
    {
      if (l_linkage_name != r_linkage_name)
    {
      // Linkage names are different.  That usually means the two
      // decls are different, unless we are looking at two
      // function declarations which have two different symbols
      // that are aliases of each other.
      const function_decl *f1 = is_function_decl(&l),
        *f2 = is_function_decl(&r);
      if (f1 && f2 && function_decls_alias(*f1, *f2))
        ;// The two functions are aliases, so they are not
         // different.
      else
        {
          result = false;
          if (k)
        *k |= LOCAL_NON_TYPE_CHANGE_KIND;
          else
        ABG_RETURN_FALSE;
        }
    }
    }

    if (r.get_is_anonymous() && l.get_is_anonymous())
      // We are looking at too anonymous types (or two members of
      // anonymous types) with one not yet been added to the IR.  That
      // means we want to compare just the object part of the
      // anonymous type and not their qualified names.  This is used
      // when looking up an anonymous type inside a class type.
      ABG_RETURN(result);

    // This is the name of the decls that we want to compare.
    interned_string ln = l.get_name(), rn = r.get_name();

    /// If both of the current decls have an anonymous scope then let's
    /// compare their name component by component by properly handling
    /// anonymous scopes. That's the slow path.
    ///
    /// Otherwise, let's just compare their name, the obvious way.
    /// That's the fast path because in that case the names are
    /// interned_string and comparing them is much faster.
    bool decls_are_same = (ln == rn);

  if (!decls_are_same)
    {
      result = false;
      if (k)
    *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }

  result &= maybe_compare_as_member_decls(l, r, k);

  ABG_RETURN(result);
}

/// Return true iff the two decls have the same name.
///
/// This function doesn't test if the scopes of the the two decls are
/// equal.
///
/// Note that this virtual function is to be implemented by classes
/// that extend the \p decl_base class.
bool
decl_base::operator==(const decl_base& other) const
{return equals(*this, other, 0);}

/// Inequality operator.
///
/// @param other to other instance of @ref decl_base to compare the
/// current instance to.
///
/// @return true iff the current instance of @ref decl_base is
/// different from @p other.
bool
decl_base::operator!=(const decl_base& other) const
{return !operator==(other);}

/// Destructor of the @ref decl_base type.
decl_base::~decl_base()
{delete priv_;}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the member nodes of the translation
/// unit during the traversal.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
decl_base::traverse(ir_node_visitor&)
{
  // Do nothing in the base class.
  return true;
}

/// Setter of the scope of the current decl.
///
/// Note that the decl won't hold a reference on the scope.  It's
/// rather the scope that holds a reference on its members.
void
decl_base::set_scope(scope_decl* scope)
{
  if (!priv_->context_)
    priv_->context_ = new context_rel(scope);
  else
    priv_->context_->set_scope(scope);
}

// </decl_base definition>

/// Streaming operator for the decl_base::visibility.
///
/// @param o the output stream to serialize the visibility to.
///
/// @param v the visibility to serialize.
///
/// @return the output stream.
std::ostream&
operator<<(std::ostream& o, decl_base::visibility v)
{
  string r;
  switch (v)
    {
    case decl_base::VISIBILITY_NONE:
      r = "none";
      break;
    case decl_base::VISIBILITY_DEFAULT:
      r = "default";
      break;
    case decl_base::VISIBILITY_PROTECTED:
      r = "protected";
      break;
    case decl_base::VISIBILITY_HIDDEN:
      r = "hidden";
      break;
    case decl_base::VISIBILITY_INTERNAL:
      r = "internal";
      break;
    }
  return o;
}

/// Streaming operator for decl_base::binding.
///
/// @param o the output stream to serialize the visibility to.
///
/// @param b the binding to serialize.
///
/// @return the output stream.
std::ostream&
operator<<(std::ostream& o, decl_base::binding b)
{
  string r;
  switch (b)
    {
    case decl_base::BINDING_NONE:
      r = "none";
      break;
    case decl_base::BINDING_LOCAL:
      r = "local";
      break;
    case decl_base::BINDING_GLOBAL:
      r = "global";
      break;
    case decl_base::BINDING_WEAK:
      r = "weak";
      break;
    }
  o << r;
  return o;
}

/// Turn equality of shared_ptr of decl_base into a deep equality;
/// that is, make it compare the pointed to objects, not just the
/// pointers.
///
/// @param l the shared_ptr of decl_base on left-hand-side of the
/// equality.
///
/// @param r the shared_ptr of decl_base on right-hand-side of the
/// equality.
///
/// @return true if the decl_base pointed to by the shared_ptrs are
/// equal, false otherwise.
bool
operator==(const decl_base_sptr& l, const decl_base_sptr& r)
{
  if (l.get() == r.get())
    return true;
  if (!!l != !!r)
    return false;

  return *l == *r;
}

/// Inequality operator of shared_ptr of @ref decl_base.
///
/// This is a deep equality operator, that is, it compares the
/// pointed-to objects, rather than just the pointers.
///
/// @param l the left-hand-side operand.
///
/// @param r the right-hand-side operand.
///
/// @return true iff @p l is different from @p r.
bool
operator!=(const decl_base_sptr& l, const decl_base_sptr& r)
{return !operator==(l, r);}

/// Turn equality of shared_ptr of type_base into a deep equality;
/// that is, make it compare the pointed to objects too.
///
/// @param l the shared_ptr of type_base on left-hand-side of the
/// equality.
///
/// @param r the shared_ptr of type_base on right-hand-side of the
/// equality.
///
/// @return true if the type_base pointed to by the shared_ptrs are
/// equal, false otherwise.
bool
operator==(const type_base_sptr& l, const type_base_sptr& r)
{
    if (l.get() == r.get())
    return true;
  if (!!l != !!r)
    return false;

  return *l == *r;
}

/// Turn inequality of shared_ptr of type_base into a deep equality;
/// that is, make it compare the pointed to objects..
///
/// @param l the shared_ptr of type_base on left-hand-side of the
/// equality.
///
/// @param r the shared_ptr of type_base on right-hand-side of the
/// equality.
///
/// @return true iff the type_base pointed to by the shared_ptrs are
/// different.
bool
operator!=(const type_base_sptr& l, const type_base_sptr& r)
{return !operator==(l, r);}

/// Tests if a declaration has got a scope.
///
/// @param d the declaration to consider.
///
/// @return true if the declaration has got a scope, false otherwise.
bool
has_scope(const decl_base& d)
{return (d.get_scope());}

/// Tests if a declaration has got a scope.
///
/// @param d the declaration to consider.
///
/// @return true if the declaration has got a scope, false otherwise.
bool
has_scope(const decl_base_sptr d)
{return has_scope(*d.get());}

/// Tests if a declaration is a class member.
///
/// @param d the declaration to consider.
///
/// @return true if @p d is a class member, false otherwise.
bool
is_member_decl(const decl_base_sptr d)
{return is_at_class_scope(d) || is_method_decl(d);}

/// Tests if a declaration is a class member.
///
/// @param d the declaration to consider.
///
/// @return true if @p d is a class member, false otherwise.
bool
is_member_decl(const decl_base* d)
{return is_at_class_scope(d) || is_method_decl(d);}

/// Tests if a declaration is a class member.
///
/// @param d the declaration to consider.
///
/// @return true if @p d is a class member, false otherwise.
bool
is_member_decl(const decl_base& d)
{return is_at_class_scope(d) || is_method_decl(d);}

/// Test if a declaration is a @ref scope_decl.
///
/// @param d the declaration to take in account.
///
/// @return the a pointer to the @ref scope_decl sub-object of @p d,
/// if d is a @ref scope_decl.
const scope_decl*
is_scope_decl(const decl_base* d)
{return dynamic_cast<const scope_decl*>(d);}

/// Test if a declaration is a @ref scope_decl.
///
/// @param d the declaration to take in account.
///
/// @return the a pointer to the @ref scope_decl sub-object of @p d,
/// if d is a @ref scope_decl.
scope_decl_sptr
is_scope_decl(const decl_base_sptr& d)
{return dynamic_pointer_cast<scope_decl>(d);}

/// Tests if a type is a class member.
///
/// @param t the type to consider.
///
/// @return true if @p t is a class member type, false otherwise.
bool
is_member_type(const type_base_sptr& t)
{
  decl_base_sptr d = get_type_declaration(t);
  return is_member_decl(d);
}

/// Test if a type is user-defined.
///
/// A type is considered user-defined if it's a
/// struct/class/union/enum that is *NOT* artificial.
///
/// @param t the type to consider.
///
/// @return true iff the type @p t is user-defined.
bool
is_user_defined_type(const type_base* t)
{
  if (t == 0)
    return false;

  t = peel_qualified_or_typedef_type(t);
  decl_base *d = is_decl(t);

  if ((is_class_or_union_type(t) || is_enum_type(t))
      && d && !d->get_is_artificial())
    return true;

  return false;
}

/// Test if a type is user-defined.
///
/// A type is considered user-defined if it's a
/// struct/class/union/enum.
///
///
/// @param t the type to consider.
///
/// @return true iff the type @p t is user-defined.
bool
is_user_defined_type(const type_base_sptr& t)
{return is_user_defined_type(t.get());}

/// Gets the access specifier for a class member.
///
/// @param d the declaration of the class member to consider.  Note
/// that this must be a class member otherwise the function aborts the
/// current process.
///
/// @return the access specifier for the class member @p d.
access_specifier
get_member_access_specifier(const decl_base& d)
{
  ABG_ASSERT(is_member_decl(d));

  const context_rel* c = d.get_context_rel();
  ABG_ASSERT(c);

  return c->get_access_specifier();
}

/// Gets the access specifier for a class member.
///
/// @param d the declaration of the class member to consider.  Note
/// that this must be a class member otherwise the function aborts the
/// current process.
///
/// @return the access specifier for the class member @p d.
access_specifier
get_member_access_specifier(const decl_base_sptr& d)
{return get_member_access_specifier(*d);}

/// Sets the access specifier for a class member.
///
/// @param d the class member to set the access specifier for.  Note
/// that this must be a class member otherwise the function aborts the
/// current process.
///
/// @param a the new access specifier to set the class member to.
void
set_member_access_specifier(decl_base& d,
                access_specifier a)
{
  ABG_ASSERT(is_member_decl(d));

  context_rel* c = d.get_context_rel();
  ABG_ASSERT(c);

  c->set_access_specifier(a);
}

/// Sets the access specifier for a class member.
///
/// @param d the class member to set the access specifier for.  Note
/// that this must be a class member otherwise the function aborts the
/// current process.
///
/// @param a the new access specifier to set the class member to.
void
set_member_access_specifier(const decl_base_sptr& d,
                access_specifier a)
{set_member_access_specifier(*d, a);}

/// Gets a flag saying if a class member is static or not.
///
/// @param d the declaration for the class member to consider. Note
/// that this must be a class member otherwise the function aborts the
/// current process.
///
/// @return true if the class member @p d is static, false otherwise.
bool
get_member_is_static(const decl_base&d)
{
  ABG_ASSERT(is_member_decl(d));

  const context_rel* c = d.get_context_rel();
  ABG_ASSERT(c);

  return c->get_is_static();
}

/// Gets a flag saying if a class member is static or not.
///
/// @param d the declaration for the class member to consider. Note
/// that this must be a class member otherwise the function aborts the
/// current process.
///
/// @return true if the class member @p d is static, false otherwise.
bool
get_member_is_static(const decl_base* d)
{return get_member_is_static(*d);}

/// Gets a flag saying if a class member is static or not.
///
/// @param d the declaration for the class member to consider.  Note
/// that this must be a class member otherwise the function aborts the
/// current process.
///
/// @return true if the class member @p d is static, false otherwise.
bool
get_member_is_static(const decl_base_sptr& d)
{return get_member_is_static(*d);}

/// Test if a var_decl is a data member.
///
/// @param v the var_decl to consider.
///
/// @return true if @p v is data member, false otherwise.
bool
is_data_member(const var_decl& v)
{return is_at_class_scope(v);}

/// Test if a var_decl is a data member.
///
/// @param v the var_decl to consider.
///
/// @return true if @p v is data member, false otherwise.
bool
is_data_member(const var_decl* v)
{return is_data_member(*v);}

/// Test if a var_decl is a data member.
///
/// @param v the var_decl to consider.
///
/// @return true if @p v is data member, false otherwise.
bool
is_data_member(const var_decl_sptr d)
{return is_at_class_scope(d);}

/// Test if a decl is a data member.
///
/// @param d the decl to consider.
///
/// @return a pointer to the data member iff @p d is a data member, or
/// a null pointer.
var_decl_sptr
is_data_member(const decl_base_sptr& d)
{
  if (var_decl_sptr v = is_var_decl(d))
    {
      if (is_data_member(v))
    return v;
    }
  return var_decl_sptr();
}

/// Test if a decl is a data member.
///
/// @param d the decl to consider.
///
/// @return a pointer to the data member iff @p d is a data member, or
/// a null pointer.
var_decl_sptr
is_data_member(const type_or_decl_base_sptr& d)
{
  if (var_decl_sptr v = is_var_decl(d))
    {
      if (is_data_member(v))
    return v;
    }
  return var_decl_sptr();
}

/// Test if a decl is a data member.
///
/// @param d the decl to consider.
///
/// @return a pointer to the data member iff @p d is a data member, or
/// a null pointer.
var_decl*
is_data_member(const type_or_decl_base* d)
{
 if (var_decl *v = is_var_decl(d))
    if (is_data_member(v))
      return v;
  return 0;
}

/// Test if a decl is a data member.
///
/// @param d the decl to consider.
///
/// @return a pointer to the data member iff @p d is a data member, or
/// a null pointer.
var_decl*
is_data_member(const decl_base *d)
{
  if (var_decl *v = is_var_decl(d))
    if (is_data_member(v))
      return v;
  return 0;
}

/// Get the first non-anonymous data member of a given anonymous data
/// member.
///
/// E.g:
///
///   struct S
///   {
///     union // <-- for this anonymous data member, the function
///           // returns a.
///     {
///       int a;
///       charb;
///     };
///   };
///
/// @return anon_dm the anonymous data member to consider.
///
/// @return the first non-anonymous data member of @p anon_dm.  If no
/// data member was found then this function returns @p anon_dm.
const var_decl_sptr
get_first_non_anonymous_data_member(const var_decl_sptr anon_dm)
{
  if (!anon_dm || !is_anonymous_data_member(anon_dm))
    return anon_dm;

  class_or_union_sptr klass = anonymous_data_member_to_class_or_union(anon_dm);
 var_decl_sptr first = *klass->get_non_static_data_members().begin();

 if (is_anonymous_data_member(first))
   return get_first_non_anonymous_data_member(first);

 return first;
}

/// In the context of a given class or union, this function returns
/// the data member that is located after a given data member.
///
/// @param klass the class or union to consider.
///
/// @param the data member to consider.
///
/// @return the data member that is located right after @p
/// data_member.
const var_decl_sptr
get_next_data_member(const class_or_union *klass,
             const var_decl_sptr &data_member)
{
  if (!klass ||!data_member)
    return var_decl_sptr();

  for (class_or_union::data_members::const_iterator it =
     klass->get_non_static_data_members().begin();
       it != klass->get_non_static_data_members().end();
       ++it)
    if (**it == *data_member)
      {
    ++it;
    if (it != klass->get_non_static_data_members().end())
      return get_first_non_anonymous_data_member(*it);
    break;
      }

  return var_decl_sptr();
}

/// In the context of a given class or union, this function returns
/// the data member that is located after a given data member.
///
/// @param klass the class or union to consider.
///
/// @param the data member to consider.
///
/// @return the data member that is located right after @p
/// data_member.
const var_decl_sptr
get_next_data_member(const class_or_union_sptr& klass,
             const var_decl_sptr &data_member)
{return get_next_data_member(klass.get(), data_member);}

/// Get the last data member of a class type.
///
/// @param klass the class type to consider.
var_decl_sptr
get_last_data_member(const class_or_union& klass)
{return klass.get_non_static_data_members().back();}

/// Get the last data member of a class type.
///
/// @param klass the class type to consider.
var_decl_sptr
get_last_data_member(const class_or_union* klass)
{return get_last_data_member(*klass);}

/// Get the last data member of a class type.
///
/// @param klass the class type to consider.
var_decl_sptr
get_last_data_member(const class_or_union_sptr &klass)
{return get_last_data_member(klass.get());}

/// Collect all the non-anonymous data members of a class or union type.
///
/// If the class contains any anonymous data member, this function
/// looks through it to collect the non-anonymous data members that it
/// contains.  The function also looks through the base classes of the
/// current type.
///
/// @param cou the class or union type to consider.
///
/// @param dms output parameter.  This is populated by the function
/// with a map containing the non-anonymous data members that were
/// collected.  The key of the map is the name of the data member.
/// This is set iff the function returns true.
///
/// @return true iff at least one non-anonymous data member was
/// collected.
bool
collect_non_anonymous_data_members(const class_or_union* cou,
                   string_decl_base_sptr_map& dms)
{
  if (!cou)
    return false;

  bool result = false;
  class_decl* klass = is_class_type(cou);
  if (klass)
    // First look into base classes for data members.
    for (class_decl::base_spec_sptr base : klass->get_base_specifiers())
      result |= collect_non_anonymous_data_members(base->get_base_class().get(), dms);

  // Then look into our data members
  for (var_decl_sptr member : cou->get_non_static_data_members())
    {
      if (is_anonymous_data_member(member))
    {
      class_or_union_sptr cl = anonymous_data_member_to_class_or_union(member);
      ABG_ASSERT(cl);
      result |= collect_non_anonymous_data_members(cl.get(), dms);
    }
      else
    {
      dms[member->get_name()] = member;
      result = true;
    }
    }
  return result;
}

/// Collect all the non-anonymous data members of a class or union type.
///
/// If the class contains any anonymous data member, this function
/// looks through it to collect the non-anonymous data members that it
/// contains.  The function also also looks through the base classes
/// of the current type.
///
/// @param cou the class or union type to consider.
///
/// @param dms output parameter.  This is populated by the function
/// with a map containing the non-anonymous data members that were
/// collected.  The key of the map is the name of the data member.
/// This is set iff the function returns true.
///
/// @return true iff at least one non-anonymous data member was
/// collected.
bool
collect_non_anonymous_data_members(const class_or_union_sptr &cou, string_decl_base_sptr_map& dms)
{return collect_non_anonymous_data_members(cou.get(), dms);}

/// Test if a decl is an anonymous data member.
///
/// @param d the decl to consider.
///
/// @return true iff @p d is an anonymous data member.
bool
is_anonymous_data_member(const decl_base& d)
{return is_anonymous_data_member(&d);}

/// Test if a decl is an anonymous data member.
///
/// @param d the decl to consider.
///
/// @return the var_decl representing the data member iff @p d is an
/// anonymous data member.
const var_decl*
is_anonymous_data_member(const type_or_decl_base* d)
{
  if (const var_decl* v = is_data_member(d))
    {
      if (is_anonymous_data_member(v))
    return v;
    }
  return 0;
}

/// Test if a decl is an anonymous data member.
///
/// @param d the decl to consider.
///
/// @return a non-nil pointer to the @ref var_decl denoted by @p d if
/// it's an anonymous data member.  Otherwise returns a nil pointer.
const var_decl*
is_anonymous_data_member(const decl_base* d)
{
  if (const var_decl* v = is_data_member(d))
    {
      if (is_anonymous_data_member(v))
    return v;
    }
  return 0;
}

/// Test if a decl is an anonymous data member.
///
/// @param d the decl to consider.
///
/// @return a non-nil pointer to the @ref var_decl denoted by @p d if
/// it's an anonymous data member.  Otherwise returns a nil pointer.
var_decl_sptr
is_anonymous_data_member(const type_or_decl_base_sptr& d)
{
  if (var_decl_sptr v = is_data_member(d))
    {
      if (is_anonymous_data_member(v))
    return v;
    }
  return var_decl_sptr();
}

/// Test if a decl is an anonymous data member.
///
/// @param d the decl to consider.
///
/// @return a non-nil pointer to the @ref var_decl denoted by @p d if
/// it's an anonymous data member.  Otherwise returns a nil pointer.
var_decl_sptr
is_anonymous_data_member(const decl_base_sptr& d)
{
  if (var_decl_sptr v = is_data_member(d))
    return is_anonymous_data_member(v);
  return var_decl_sptr();
}

/// Test if a @ref var_decl is an anonymous data member.
///
/// @param d the @ref var_decl to consider.
///
/// @return a non-nil pointer to the @ref var_decl denoted by @p d if
/// it's an anonymous data member.  Otherwise returns a nil pointer.
var_decl_sptr
is_anonymous_data_member(const var_decl_sptr& d)
{
  if (is_anonymous_data_member(d.get()))
    return d;
  return var_decl_sptr();
}

/// Test if a @ref var_decl is an anonymous data member.
///
/// @param d the @ref var_decl to consider.
///
/// @return a non-nil pointer to the @ref var_decl denoted by @p d if
/// it's an anonymous data member.  Otherwise returns a nil pointer.
const var_decl*
is_anonymous_data_member(const var_decl* d)
{
  if (d && is_anonymous_data_member(*d))
    return d;
  return 0;
}

/// Test if a @ref var_decl is an anonymous data member.
///
/// @param d the @ref var_decl to consider.
///
/// @return true iff @p d is an anonymous data member.
bool
is_anonymous_data_member(const var_decl& d)
{
  return (is_data_member(d)
      && d.get_is_anonymous()
      && d.get_name().empty()
      && is_class_or_union_type(d.get_type()));
}

/// Test if a @ref var_decl is a data member belonging to an anonymous
/// type.
///
/// @param d the @ref var_decl to consider.
///
/// @return true iff @p d is a data member belonging to an anonymous
/// type.
bool
is_data_member_of_anonymous_class_or_union(const var_decl& d)
{
  if (is_data_member(d))
    {
      scope_decl* scope = d.get_scope();
      if (scope && scope->get_is_anonymous())
    return true;
    }
  return false;
}

/// Test if a @ref var_decl is a data member belonging to an anonymous
/// type.
///
/// @param d the @ref var_decl to consider.
///
/// @return true iff @p d is a data member belonging to an anonymous
/// type.
bool
is_data_member_of_anonymous_class_or_union(const var_decl* d)
{return is_data_member_of_anonymous_class_or_union(*d);}

/// Test if a @ref var_decl is a data member belonging to an anonymous
/// type.
///
/// @param d the @ref var_decl to consider.
///
/// @return true iff @p d is a data member belonging to an anonymous
/// type.
bool
is_data_member_of_anonymous_class_or_union(const var_decl_sptr& d)
{return is_data_member_of_anonymous_class_or_union(d.get());}

/// Get the @ref class_or_union type of a given anonymous data member.
///
/// @param d the anonymous data member to consider.
///
/// @return the @ref class_or_union type of the anonymous data member
/// @p d.
class_or_union*
anonymous_data_member_to_class_or_union(const var_decl* d)
{
  if ((d = is_anonymous_data_member(d)))
    return is_class_or_union_type(d->get_type().get());
  return 0;
}

/// Get the @ref class_or_union type of a given anonymous data member.
///
/// @param d the anonymous data member to consider.
///
/// @return the @ref class_or_union type of the anonymous data member
/// @p d.
class_or_union_sptr
anonymous_data_member_to_class_or_union(const var_decl& d)
{
  if (is_anonymous_data_member(d))
    return is_class_or_union_type(d.get_type());
  return class_or_union_sptr();
}

/// Test if a data member has annonymous type or not.
///
/// @param d the data member to consider.
///
/// @return the anonymous class or union type iff @p turns out to have
/// an anonymous type.  Otherwise, returns nil.
const class_or_union_sptr
data_member_has_anonymous_type(const var_decl& d)
{
  if (is_data_member(d))
    if (const class_or_union_sptr cou = is_class_or_union_type(d.get_type()))
      if (cou->get_is_anonymous())
    return cou;

  return class_or_union_sptr();
}

/// Test if a data member has annonymous type or not.
///
/// @param d the data member to consider.
///
/// @return the anonymous class or union type iff @p turns out to have
/// an anonymous type.  Otherwise, returns nil.
const class_or_union_sptr
data_member_has_anonymous_type(const var_decl* d)
{
  if (d)
    return data_member_has_anonymous_type(*d);
  return class_or_union_sptr();
}

/// Test if a data member has annonymous type or not.
///
/// @param d the data member to consider.
///
/// @return the anonymous class or union type iff @p turns out to have
/// an anonymous type.  Otherwise, returns nil.
const class_or_union_sptr
data_member_has_anonymous_type(const var_decl_sptr& d)
{return data_member_has_anonymous_type(d.get());}

/// Get the @ref class_or_union type of a given anonymous data member.
///
/// @param d the anonymous data member to consider.
///
/// @return the @ref class_or_union type of the anonymous data member
/// @p d.
class_or_union_sptr
anonymous_data_member_to_class_or_union(const var_decl_sptr &d)
{
  if (var_decl_sptr v = is_anonymous_data_member(d))
    return is_class_or_union_type(v->get_type());
  return class_or_union_sptr();
}

/// Test if a given anonymous data member exists in a class or union.
///
/// @param anon_dm the anonymous data member to consider.
///
/// @param clazz the class to consider.
///
/// @return true iff @p anon_dm exists in the @clazz.
bool
anonymous_data_member_exists_in_class(const var_decl& anon_dm,
                      const class_or_union& clazz)
{
  if (!anon_dm.get_is_anonymous()
      || !is_class_or_union_type(anon_dm.get_type()))
    return false;

  class_or_union_sptr cl = is_class_or_union_type(anon_dm.get_type());
  ABG_ASSERT(cl);

  // Look for the presence of each data member of anon_dm in clazz.
  //
  // If one data member of anon_dm is not present in clazz, then the
  // data member anon_dm is considered to not exist in clazz.
  for (auto anon_dm_m : cl->get_non_static_data_members())
    {
      // If the data member anon_dm_m is not an anonymous data member,
      // it's easy to look for it.
      if (!is_anonymous_data_member(anon_dm_m))
    {
      if (!clazz.find_data_member(anon_dm_m->get_name()))
        return false;
    }
      // If anon_dm_m is itself an anonymous data member then recurse
      else
    {
      if (!anonymous_data_member_exists_in_class(*anon_dm_m, clazz))
        return false;
    }
    }

  return true;
}

/// Test if a given decl is anonymous or has a naming typedef.
///
/// @param d the decl to consider.
///
/// @return true iff @p d is anonymous or has a naming typedef.
bool
is_anonymous_or_typedef_named(const decl_base& d)
{
  if (d.get_is_anonymous() || d.get_naming_typedef())
    return true;
  return false;
}

/// Set the offset of a data member into its containing class.
///
/// @param m the data member to consider.
///
/// @param o the offset, in bits.
void
set_data_member_offset(var_decl_sptr m, uint64_t o)
{
  ABG_ASSERT(is_data_member(m));

  dm_context_rel* ctxt_rel =
    dynamic_cast<dm_context_rel*>(m->get_context_rel());
  ABG_ASSERT(ctxt_rel);

  ctxt_rel->set_offset_in_bits(o);
}

/// Get the offset of a data member.
///
/// @param m the data member to consider.
///
/// @return the offset (in bits) of @p m in its containing class.
uint64_t
get_data_member_offset(const var_decl& m)
{
  ABG_ASSERT(is_data_member(m));
  const dm_context_rel* ctxt_rel =
    dynamic_cast<const dm_context_rel*>(m.get_context_rel());
  ABG_ASSERT(ctxt_rel);
  return ctxt_rel->get_offset_in_bits();
}

/// Get the offset of a data member.
///
/// @param m the data member to consider.
///
/// @return the offset (in bits) of @p m in its containing class.
uint64_t
get_data_member_offset(const var_decl_sptr m)
{return get_data_member_offset(*m);}

/// Get the offset of a data member.
///
/// @param m the data member to consider.
///
/// @return the offset (in bits) of @p m in its containing class.
uint64_t
get_data_member_offset(const decl_base_sptr d)
{return get_data_member_offset(dynamic_pointer_cast<var_decl>(d));}

/// Get the offset of the non-static data member that comes after a
/// given one.
///
/// If there is no data member after after the one given to this
/// function (maybe because the given one is the last data member of
/// the class type) then the function return false.
///
/// @param klass the class to consider.
///
/// @param dm the data member before the one we want to retrieve.
///
/// @param offset out parameter.  This parameter is set by the
/// function to the offset of the data member that comes right after
/// the data member @p dm, iff the function returns true.
///
/// @return true iff the data member coming right after @p dm was
/// found.
bool
get_next_data_member_offset(const class_or_union* klass,
                const var_decl_sptr& dm,
                uint64_t& offset)
{
  var_decl_sptr next_dm = get_next_data_member(klass, dm);
  if (!next_dm)
    return false;
  offset = get_data_member_offset(next_dm);
  return true;
}

/// Get the offset of the non-static data member that comes after a
/// given one.
///
/// If there is no data member after after the one given to this
/// function (maybe because the given one is the last data member of
/// the class type) then the function return false.
///
/// @param klass the class to consider.
///
/// @param dm the data member before the one we want to retrieve.
///
/// @param offset out parameter.  This parameter is set by the
/// function to the offset of the data member that comes right after
/// the data member @p dm, iff the function returns true.
///
/// @return true iff the data member coming right after @p dm was
/// found.
bool
get_next_data_member_offset(const class_or_union_sptr& klass,
                const var_decl_sptr& dm,
                uint64_t& offset)
{return get_next_data_member_offset(klass.get(), dm, offset);}

/// Get the absolute offset of a data member.
///
/// If the data member is part of an anonymous data member then this
/// returns the absolute offset -- relative to the beginning of the
/// containing class of the anonymous data member.
///
/// @param m the data member to consider.
///
/// @return the aboslute offset of the data member @p m.
uint64_t
get_absolute_data_member_offset(const var_decl& m)
{
  ABG_ASSERT(is_data_member(m));
  const dm_context_rel* ctxt_rel =
    dynamic_cast<const dm_context_rel*>(m.get_context_rel());
  ABG_ASSERT(ctxt_rel);

  const var_decl *containing_anonymous_data_member =
    ctxt_rel->get_anonymous_data_member();

  uint64_t containing_anonymous_data_member_offset = 0;
  if (containing_anonymous_data_member)
    containing_anonymous_data_member_offset =
      get_absolute_data_member_offset(*containing_anonymous_data_member);

  return (ctxt_rel->get_offset_in_bits()
      +
      containing_anonymous_data_member_offset);
}

/// Get the absolute offset of a data member.
///
/// If the data member is part of an anonymous data member then this
/// returns the absolute offset -- relative to the beginning of the
/// containing class of the anonymous data member.
///
/// @param m the data member to consider.
///
/// @return the aboslute offset of the data member @p m.
uint64_t
get_absolute_data_member_offset(const var_decl_sptr& m)
{
  if (!m)
    return 0;
  return get_absolute_data_member_offset(*m);
}

/// Get the size of a given variable.
///
/// @param v the variable to consider.
///
/// @return the size of variable @p v.
uint64_t
get_var_size_in_bits(const var_decl_sptr& v)
{
  type_base_sptr t = v->get_type();
  ABG_ASSERT(t);

  return t->get_size_in_bits();
}

/// Set a flag saying if a data member is laid out.
///
/// @param m the data member to consider.
///
/// @param l true if @p m is to be considered as laid out.
void
set_data_member_is_laid_out(var_decl_sptr m, bool l)
{
  ABG_ASSERT(is_data_member(m));
  dm_context_rel* ctxt_rel =
    dynamic_cast<dm_context_rel*>(m->get_context_rel());
  ctxt_rel->set_is_laid_out(l);
}

/// Test whether a data member is laid out.
///
/// @param m the data member to consider.
///
/// @return true if @p m is laid out, false otherwise.
bool
get_data_member_is_laid_out(const var_decl& m)
{
  ABG_ASSERT(is_data_member(m));
  const dm_context_rel* ctxt_rel =
    dynamic_cast<const dm_context_rel*>(m.get_context_rel());

  return ctxt_rel->get_is_laid_out();
}

/// Test whether a data member is laid out.
///
/// @param m the data member to consider.
///
/// @return true if @p m is laid out, false otherwise.
bool
get_data_member_is_laid_out(const var_decl_sptr m)
{return get_data_member_is_laid_out(*m);}

/// Test whether a function_decl is a member function.
///
/// @param f the function_decl to test.
///
/// @return true if @p f is a member function, false otherwise.
bool
is_member_function(const function_decl& f)
{return is_member_decl(f);}

/// Test whether a function_decl is a member function.
///
/// @param f the function_decl to test.
///
/// @return true if @p f is a member function, false otherwise.
bool
is_member_function(const function_decl* f)
{return is_member_decl(*f);}

/// Test whether a function_decl is a member function.
///
/// @param f the function_decl to test.
///
/// @return true if @p f is a member function, false otherwise.
bool
is_member_function(const function_decl_sptr& f)
{return is_member_decl(*f);}

/// Test whether a member function is a constructor.
///
/// @param f the member function to test.
///
/// @return true if @p f is a constructor, false otherwise.
bool
get_member_function_is_ctor(const function_decl& f)
{
  ABG_ASSERT(is_member_function(f));

  const method_decl* m = is_method_decl(&f);
  ABG_ASSERT(m);

  const mem_fn_context_rel* ctxt =
    dynamic_cast<const mem_fn_context_rel*>(m->get_context_rel());

  return ctxt->is_constructor();
}

/// Test whether a member function is a constructor.
///
/// @param f the member function to test.
///
/// @return true if @p f is a constructor, false otherwise.
bool
get_member_function_is_ctor(const function_decl_sptr& f)
{return get_member_function_is_ctor(*f);}


/// Setter for the is_ctor property of the member function.
///
/// @param f the member function to set.
///
/// @param f the new boolean value of the is_ctor property.  Is true
/// if @p f is a constructor, false otherwise.
void
set_member_function_is_ctor(function_decl& f, bool c)
{
  ABG_ASSERT(is_member_function(f));

  method_decl* m = is_method_decl(&f);
  ABG_ASSERT(m);

  mem_fn_context_rel* ctxt =
    dynamic_cast<mem_fn_context_rel*>(m->get_context_rel());

  ctxt->is_constructor(c);
}

/// Setter for the is_ctor property of the member function.
///
/// @param f the member function to set.
///
/// @param f the new boolean value of the is_ctor property.  Is true
/// if @p f is a constructor, false otherwise.
void
set_member_function_is_ctor(const function_decl_sptr& f, bool c)
{set_member_function_is_ctor(*f, c);}

/// Test whether a member function is a destructor.
///
/// @param f the function to test.
///
/// @return true if @p f is a destructor, false otherwise.
bool
get_member_function_is_dtor(const function_decl& f)
{
  ABG_ASSERT(is_member_function(f));

  const method_decl* m = is_method_decl(&f);
  ABG_ASSERT(m);

  const mem_fn_context_rel* ctxt =
    dynamic_cast<const mem_fn_context_rel*>(m->get_context_rel());

  return ctxt->is_destructor();
}

/// Test whether a member function is a destructor.
///
/// @param f the function to test.
///
/// @return true if @p f is a destructor, false otherwise.
bool
get_member_function_is_dtor(const function_decl_sptr& f)
{return get_member_function_is_dtor(*f);}

/// Set the destructor-ness property of a member function.
///
/// @param f the function to set.
///
/// @param d true if @p f is a destructor, false otherwise.
void
set_member_function_is_dtor(function_decl& f, bool d)
{
    ABG_ASSERT(is_member_function(f));

    method_decl* m = is_method_decl(&f);
  ABG_ASSERT(m);

  mem_fn_context_rel* ctxt =
    dynamic_cast<mem_fn_context_rel*>(m->get_context_rel());

  ctxt->is_destructor(d);
}

/// Set the destructor-ness property of a member function.
///
/// @param f the function to set.
///
/// @param d true if @p f is a destructor, false otherwise.
void
set_member_function_is_dtor(const function_decl_sptr& f, bool d)
{set_member_function_is_dtor(*f, d);}

/// Test whether a member function is const.
///
/// @param f the function to test.
///
/// @return true if @p f is const, false otherwise.
bool
get_member_function_is_const(const function_decl& f)
{
  ABG_ASSERT(is_member_function(f));

  const method_decl* m = is_method_decl(&f);
  ABG_ASSERT(m);

  const mem_fn_context_rel* ctxt =
    dynamic_cast<const mem_fn_context_rel*>(m->get_context_rel());

  return ctxt->is_const();
}

/// Test whether a member function is const.
///
/// @param f the function to test.
///
/// @return true if @p f is const, false otherwise.
bool
get_member_function_is_const(const function_decl_sptr& f)
{return get_member_function_is_const(*f);}

/// set the const-ness property of a member function.
///
/// @param f the function to set.
///
/// @param is_const the new value of the const-ness property of @p f
void
set_member_function_is_const(function_decl& f, bool is_const)
{
  ABG_ASSERT(is_member_function(f));

  method_decl* m = is_method_decl(&f);
  ABG_ASSERT(m);

  mem_fn_context_rel* ctxt =
    dynamic_cast<mem_fn_context_rel*>(m->get_context_rel());

  ctxt->is_const(is_const);
}

/// set the const-ness property of a member function.
///
/// @param f the function to set.
///
/// @param is_const the new value of the const-ness property of @p f
void
set_member_function_is_const(const function_decl_sptr& f, bool is_const)
{set_member_function_is_const(*f, is_const);}

/// Test if a virtual member function has a vtable offset set.
///
/// @param f the virtual member function to consider.
///
/// @return true iff the virtual member function has its vtable offset
/// set, i.e, if the vtable offset of @p is different from -1.
bool
member_function_has_vtable_offset(const function_decl& f)
{return get_member_function_vtable_offset(f) != -1;}

/// Get the vtable offset of a member function.
///
/// @param f the member function to consider.
///
/// @return the vtable offset of @p f.  Note that a vtable offset of
/// value -1 means that the member function does *NOT* yet have a
/// vtable offset associated to it.
ssize_t
get_member_function_vtable_offset(const function_decl& f)
{
  ABG_ASSERT(is_member_function(f));

  const method_decl* m =
    dynamic_cast<const method_decl*>(&f);
  ABG_ASSERT(m);

  const mem_fn_context_rel* ctxt =
    dynamic_cast<const mem_fn_context_rel*>(m->get_context_rel());

  return ctxt->vtable_offset();
}

/// Get the vtable offset of a member function.
///
/// @param f the member function to consider.
///
/// @return the vtable offset of @p f.  Note that a vtable offset of
/// value -1 means that the member function does *NOT* yet have a
/// vtable offset associated to it.
ssize_t
get_member_function_vtable_offset(const function_decl_sptr& f)
{return get_member_function_vtable_offset(*f);}

/// Set the vtable offset of a member function.
///
/// @param f the member function to consider.
///
/// @param s the new vtable offset.  Please note that a vtable offset
/// of value -1 means that the virtual member function does not (yet)
/// have any vtable offset associated to it.
static void
set_member_function_vtable_offset(function_decl& f, ssize_t s)
{
  ABG_ASSERT(is_member_function(f));

  method_decl* m = is_method_decl(&f);
  ABG_ASSERT(m);

  mem_fn_context_rel* ctxt =
    dynamic_cast<mem_fn_context_rel*>(m->get_context_rel());

  ctxt->vtable_offset(s);
}

/// Get the vtable offset of a member function.
///
/// @param f the member function to consider.
///
/// @param s the new vtable offset.  Please note that a vtable offset
/// of value -1 means that the virtual member function does not (yet)
/// have any vtable offset associated to it.
static void
set_member_function_vtable_offset(const function_decl_sptr& f, ssize_t s)
{return set_member_function_vtable_offset(*f, s);}

/// Test if a given member function is virtual.
///
/// @param mem_fn the member function to consider.
///
/// @return true iff a @p mem_fn is virtual.
bool
get_member_function_is_virtual(const function_decl& f)
{
  ABG_ASSERT(is_member_function(f));

  const method_decl* m =
    dynamic_cast<const method_decl*>(&f);
  ABG_ASSERT(m);

  const mem_fn_context_rel* ctxt =
    dynamic_cast<const mem_fn_context_rel*>(m->get_context_rel());

  return ctxt->is_virtual();
}

/// Test if a given member function is virtual.
///
/// @param mem_fn the member function to consider.
///
/// @return true iff a @p mem_fn is virtual.
bool
get_member_function_is_virtual(const function_decl_sptr& mem_fn)
{return mem_fn ? get_member_function_is_virtual(*mem_fn) : false;}

/// Test if a given member function is virtual.
///
/// @param mem_fn the member function to consider.
///
/// @return true iff a @p mem_fn is virtual.
bool
get_member_function_is_virtual(const function_decl* mem_fn)
{return mem_fn ? get_member_function_is_virtual(*mem_fn) : false;}

/// Set the virtual-ness of a member function.
///
/// @param f the member function to consider.
///
/// @param is_virtual set to true if the function is virtual.
static void
set_member_function_is_virtual(function_decl& f, bool is_virtual)
{
  ABG_ASSERT(is_member_function(f));

  method_decl* m = is_method_decl(&f);
  ABG_ASSERT(m);

  mem_fn_context_rel* ctxt =
    dynamic_cast<mem_fn_context_rel*>(m->get_context_rel());

  ctxt->is_virtual(is_virtual);
}

/// Set the virtual-ness of a member function.
///
/// @param f the member function to consider.
///
/// @param is_virtual set to true if the function is virtual.
static void
set_member_function_is_virtual(const function_decl_sptr& fn, bool is_virtual)
{
  if (fn)
    {
      set_member_function_is_virtual(*fn, is_virtual);
      fixup_virtual_member_function(is_method_decl(fn));
    }
}

/// Set the virtual-ness of a member fcuntion
///
/// @param fn the member function to consider.
///
/// @param is_virtual whether the function is virtual.
///
/// @param voffset the virtual offset of the virtual function.
void
set_member_function_virtuality(function_decl&   fn,
                   bool     is_virtual,
                   ssize_t      voffset)
{
  // Setting the offset must come first because the second function
  // does assume the voffset is set, in case of virtuality
  set_member_function_vtable_offset(fn, voffset);
  set_member_function_is_virtual(fn, is_virtual);
}

/// Set the virtual-ness of a member fcuntion
///
/// @param fn the member function to consider.
///
/// @param is_virtual whether the function is virtual.
///
/// @param voffset the virtual offset of the virtual function.
void
set_member_function_virtuality(function_decl*   fn,
                   bool     is_virtual,
                   ssize_t      voffset)
{
  if (fn)
    set_member_function_virtuality(*fn, is_virtual, voffset);
}

/// Set the virtual-ness of a member fcuntion
///
/// @param fn the member function to consider.
///
/// @param is_virtual whether the function is virtual.
///
/// @param voffset the virtual offset of the virtual function.
void
set_member_function_virtuality(const function_decl_sptr&    fn,
                   bool             is_virtual,
                   ssize_t              voffset)
{
  set_member_function_vtable_offset(fn, voffset);
  set_member_function_is_virtual(fn, is_virtual);
}

/// Recursively returns the the underlying type of a typedef.  The
/// return type should not be a typedef of anything anymore.
///
///
/// Also recursively strip typedefs from the sub-types of the type
/// given in arguments.
///
/// Note that this function builds types in which typedefs are
/// stripped off.  Usually, types are held by their scope, so their
/// life time is bound to the life time of their scope.  But as this
/// function cannot really insert the built type into it's scope, it
/// must ensure that the newly built type stays live long enough.
///
/// So, if the newly built type has a canonical type, this function
/// returns the canonical type.  Otherwise, this function ensure that
/// the newly built type has a life time that is the same as the life
/// time of the entire libabigail library.
///
/// @param type the type to strip the typedefs from.
///
/// @return the resulting type stripped from its typedefs, or just
/// return @p type if it has no typedef in any of its sub-types.
type_base_sptr
strip_typedef(const type_base_sptr type)
{
  if (!type)
    return type;

  // If type is a class type then do not try to strip typedefs from it.
  // And if it has no canonical type (which can mean that it's a
  // declaration-only class), then, make sure its live for ever and
  // return it.
  if (class_decl_sptr cl = is_class_type(type))
    {
      if (!cl->get_canonical_type())
    keep_type_alive(type);
      return type;
    }

  const environment& env = type->get_environment();
  type_base_sptr t = type;

  if (const typedef_decl_sptr ty = is_typedef(t))
    t = strip_typedef(type_or_void(ty->get_underlying_type(), env));
  else if (const reference_type_def_sptr ty = is_reference_type(t))
    {
      type_base_sptr p = strip_typedef(type_or_void(ty->get_pointed_to_type(),
                            env));
      ABG_ASSERT(p);
      t.reset(new reference_type_def(p,
                     ty->is_lvalue(),
                     ty->get_size_in_bits(),
                     ty->get_alignment_in_bits(),
                     ty->get_location()));
    }
  else if (const pointer_type_def_sptr ty = is_pointer_type(t))
    {
      type_base_sptr p = strip_typedef(type_or_void(ty->get_pointed_to_type(),
                            env));
      ABG_ASSERT(p);
      t.reset(new pointer_type_def(p,
                   ty->get_size_in_bits(),
                   ty->get_alignment_in_bits(),
                   ty->get_location()));
    }
  else if (const qualified_type_def_sptr ty = is_qualified_type(t))
    {
      type_base_sptr p = strip_typedef(type_or_void(ty->get_underlying_type(),
                            env));
      ABG_ASSERT(p);
      t.reset(new qualified_type_def(p,
                     ty->get_cv_quals(),
                     ty->get_location()));
    }
  else if (const array_type_def_sptr ty = is_array_type(t))
    {
      type_base_sptr p = strip_typedef(ty->get_element_type());
      ABG_ASSERT(p);
      t.reset(new array_type_def(p, ty->get_subranges(), ty->get_location()));
    }
  else if (const method_type_sptr ty = is_method_type(t))
    {
      function_decl::parameters parm;
      for (function_decl::parameters::const_iterator i =
         ty->get_parameters().begin();
       i != ty->get_parameters().end();
       ++i)
    {
      function_decl::parameter_sptr p = *i;
      type_base_sptr typ = strip_typedef(p->get_type());
      ABG_ASSERT(typ);
      function_decl::parameter_sptr stripped
        (new function_decl::parameter(typ,
                      p->get_index(),
                      p->get_name(),
                      p->get_location(),
                      p->get_variadic_marker(),
                      p->get_is_artificial()));
      parm.push_back(stripped);
    }
      type_base_sptr p = strip_typedef(ty->get_return_type());
      ABG_ASSERT(!!p == !!ty->get_return_type());
      t.reset(new method_type(p, ty->get_class_type(),
                  parm, ty->get_is_const(),
                  ty->get_size_in_bits(),
                  ty->get_alignment_in_bits()));
    }
  else if (const function_type_sptr ty = is_function_type(t))
    {
      function_decl::parameters parm;
      for (function_decl::parameters::const_iterator i =
         ty->get_parameters().begin();
       i != ty->get_parameters().end();
       ++i)
    {
      function_decl::parameter_sptr p = *i;
      type_base_sptr typ = strip_typedef(p->get_type());
      ABG_ASSERT(typ);
      function_decl::parameter_sptr stripped
        (new function_decl::parameter(typ,
                      p->get_index(),
                      p->get_name(),
                      p->get_location(),
                      p->get_variadic_marker(),
                      p->get_is_artificial()));
      parm.push_back(stripped);
    }
      type_base_sptr p = strip_typedef(ty->get_return_type());
      ABG_ASSERT(!!p == !!ty->get_return_type());
      t.reset(new function_type(p, parm,
                ty->get_size_in_bits(),
                ty->get_alignment_in_bits()));
    }

  if (!t->get_translation_unit())
    t->set_translation_unit(type->get_translation_unit());

  if (!(type->get_canonical_type() && canonicalize(t)))
    keep_type_alive(t);

  return t->get_canonical_type() ? t->get_canonical_type() : t;
}

/// Strip qualification from a qualified type, when it makes sense.
///
/// DWARF constructs "const reference".  This is redundant because a
/// reference is always const.  It also constructs the useless "const
/// void" type.  The issue is these redundant types then leak into the
/// IR and make for bad diagnostics.
///
/// This function thus strips the const qualifier from the type in
/// that case.  It might contain code to strip other cases like this
/// in the future.
///
/// @param t the type to strip const qualification from.
///
/// @return the stripped type or just return @p t.
decl_base_sptr
strip_useless_const_qualification(const qualified_type_def_sptr t)
{
  if (!t)
    return t;

  decl_base_sptr result = t;
  type_base_sptr u = t->get_underlying_type();
  const environment& env = t->get_environment();

  if ((t->get_cv_quals() & qualified_type_def::CV_CONST
       && (is_reference_type(u)))
      || (t->get_cv_quals() & qualified_type_def::CV_CONST
      && env.is_void_type(u))
      || t->get_cv_quals() == qualified_type_def::CV_NONE)
    // Let's strip the const qualifier because a reference is always
    // 'const' and a const void doesn't make sense.  They will just
    // lead to spurious changes later down the pipeline, that we'll
    // have to deal with by doing painful and error-prone editing of
    // the diff IR.  Dropping that useless and inconsistent artefact
    // right here seems to be a good way to go.
    result = is_decl(u);

  return result;
}

/// Merge redundant qualifiers from a tree of qualified types.
///
/// Suppose a tree of qualified types leads to:
///
///     const virtual const restrict const int;
///
/// Suppose the IR tree of qualified types ressembles (with C meaning
/// const, V meaning virtual and R meaning restrict):
///
///     [C|V]-->[C|R] -->[C] --> [int].
///
/// This function walks the IR and remove the redundant CV qualifiers
/// so the IR becomes:
///
///     [C|V] --> [R] --> []  -->[int].
///
/// Note that the empty qualified type (noted []) represents a
/// qualified type with no qualifier.  It's rare, but it can exist.
/// I've put it here just for the sake of example.
///
/// The resulting IR thus represents the (merged) type:
///
///    const virtual restrict int.
///
/// This function is a sub-routine of the overload @ref
/// strip_useless_const_qualification which doesn't return any value.
///
/// @param t the qualified type to consider.
///
/// @param redundant_quals the (redundant) qualifiers to be removed
/// from the qualifiers of the underlying types of @p t.
///
/// @return the underlying type of @p t which might have had its
/// redundant qualifiers removed.
static qualified_type_def_sptr
strip_redundant_quals_from_underyling_types(const qualified_type_def_sptr& t,
                        qualified_type_def::CV redundant_quals)
{
  if (!t)
    return t;

  // We must NOT edit canonicalized types.
  ABG_ASSERT(!t->get_canonical_type());

  qualified_type_def_sptr underlying_qualified_type =
    is_qualified_type(t->get_underlying_type());

  // Let's build 'currated qualifiers' that are the qualifiers of the
  // current type from which redundant qualifiers are removed.
  qualified_type_def::CV currated_quals = t->get_cv_quals();

  // Remove the redundant qualifiers from these currated qualifiers
  currated_quals &= ~redundant_quals;
  t->set_cv_quals(currated_quals);

  // The redundant qualifiers, moving forward, is now the union of the
  // previous set of redundant qualifiers and the currated qualifiers.
  redundant_quals |= currated_quals;

  qualified_type_def_sptr result = t;
  if (underlying_qualified_type)
    // Now remove the redundant qualifiers from the qualified types
    // potentially carried by the underlying type.
    result =
      strip_redundant_quals_from_underyling_types(underlying_qualified_type,
                          redundant_quals);

  return result;
}

/// Merge redundant qualifiers from a tree of qualified types.
///
/// Suppose a tree of qualified types leads to:
///
///     const virtual const restrict const int;
///
/// Suppose the IR tree of qualified types ressembles (with C meaning
/// const, V meaning virtual and R meaning restrict):
///
///     [C|V]-->[C|R] -->[C] --> [int].
///
/// This function walks the IR and remove the redundant CV qualifiers
/// so the IR becomes:
///
///     [C|V] --> [R] --> []  -->[int].
///
/// Note that the empty qualified type (noted []) represents a
/// qualified type with no qualifier.  It's rare, but it can exist.
/// I've put it here just for the sake of example.
///
/// The resulting IR thus represents the (merged) type:
///
///    const virtual restrict int.
///
/// @param t the qualified type to consider.  The IR below the
/// argument to this parameter will be edited to remove redundant
/// qualifiers where applicable.
void
strip_redundant_quals_from_underyling_types(const qualified_type_def_sptr& t)
{
  if (!t)
    return;

  qualified_type_def::CV redundant_quals = qualified_type_def::CV_NONE;
  strip_redundant_quals_from_underyling_types(t, redundant_quals);
}

/// Return the leaf underlying type node of a @ref typedef_decl node.
///
/// If the underlying type of a @ref typedef_decl node is itself a
/// @ref typedef_decl node, then recursively look at the underlying
/// type nodes to get the first one that is not a a @ref typedef_decl
/// node.  This is what a leaf underlying type node means.
///
/// Otherwise, if the underlying type node of @ref typedef_decl is
/// *NOT* a @ref typedef_decl node, then just return the underlying
/// type node.
///
/// And if the type node considered is not a @ref typedef_decl node,
/// then just return it.
///
/// @return the leaf underlying type node of a @p type.
type_base_sptr
peel_typedef_type(const type_base_sptr& type)
{
  typedef_decl_sptr t = is_typedef(type);
  if (!t)
    return type;

  if (is_typedef(t->get_underlying_type()))
    return peel_typedef_type(t->get_underlying_type());
  return t->get_underlying_type();
}

/// Return the leaf underlying type node of a @ref typedef_decl node.
///
/// If the underlying type of a @ref typedef_decl node is itself a
/// @ref typedef_decl node, then recursively look at the underlying
/// type nodes to get the first one that is not a a @ref typedef_decl
/// node.  This is what a leaf underlying type node means.
///
/// Otherwise, if the underlying type node of @ref typedef_decl is
/// *NOT* a @ref typedef_decl node, then just return the underlying
/// type node.
///
/// And if the type node considered is not a @ref typedef_decl node,
/// then just return it.
///
/// @return the leaf underlying type node of a @p type.
const type_base*
peel_typedef_type(const type_base* type)
{
  const typedef_decl* t = is_typedef(type);
  if (!t)
    return type;

  return peel_typedef_type(t->get_underlying_type()).get();
}

/// Return the leaf pointed-to type node of a @ref pointer_type_def
/// node.
///
/// If the pointed-to type of a @ref pointer_type_def node is itself a
/// @ref pointer_type_def node, then recursively look at the
/// pointed-to type nodes to get the first one that is not a a @ref
/// pointer_type_def node.  This is what a leaf pointed-to type node
/// means.
///
/// Otherwise, if the pointed-to type node of @ref pointer_type_def is
/// *NOT* a @ref pointer_type_def node, then just return the
/// pointed-to type node.
///
/// And if the type node considered is not a @ref pointer_type_def
/// node, then just return it.
///
/// @return the leaf pointed-to type node of a @p type.
type_base_sptr
peel_pointer_type(const type_base_sptr& type)
{
  pointer_type_def_sptr t = is_pointer_type(type);
  if (!t)
    return type;

  if (is_pointer_type(t->get_pointed_to_type()))
    return peel_pointer_type(t->get_pointed_to_type());
  return t->get_pointed_to_type();
}

/// Return the leaf pointed-to type node of a @ref pointer_type_def
/// node.
///
/// If the pointed-to type of a @ref pointer_type_def node is itself a
/// @ref pointer_type_def node, then recursively look at the
/// pointed-to type nodes to get the first one that is not a a @ref
/// pointer_type_def node.  This is what a leaf pointed-to type node
/// means.
///
/// Otherwise, if the pointed-to type node of @ref pointer_type_def is
/// *NOT* a @ref pointer_type_def node, then just return the
/// pointed-to type node.
///
/// And if the type node considered is not a @ref pointer_type_def
/// node, then just return it.
///
/// @return the leaf pointed-to type node of a @p type.
const type_base*
peel_pointer_type(const type_base* type)
{
  const pointer_type_def* t = is_pointer_type(type);
  if (!t)
    return type;

  return peel_pointer_type(t->get_pointed_to_type()).get();
}

/// Return the leaf pointed-to type node of a @ref reference_type_def
/// node.
///
/// If the pointed-to type of a @ref reference_type_def node is itself
/// a @ref reference_type_def node, then recursively look at the
/// pointed-to type nodes to get the first one that is not a a @ref
/// reference_type_def node.  This is what a leaf pointed-to type node
/// means.
///
/// Otherwise, if the pointed-to type node of @ref reference_type_def
/// is *NOT* a @ref reference_type_def node, then just return the
/// pointed-to type node.
///
/// And if the type node considered is not a @ref reference_type_def
/// node, then just return it.
///
/// @return the leaf pointed-to type node of a @p type.
type_base_sptr
peel_reference_type(const type_base_sptr& type)
{
  reference_type_def_sptr t = is_reference_type(type);
  if (!t)
    return type;

  if (is_reference_type(t->get_pointed_to_type()))
    return peel_reference_type(t->get_pointed_to_type());
  return t->get_pointed_to_type();
}

/// Return the leaf pointed-to type node of a @ref reference_type_def
/// node.
///
/// If the pointed-to type of a @ref reference_type_def node is itself
/// a @ref reference_type_def node, then recursively look at the
/// pointed-to type nodes to get the first one that is not a a @ref
/// reference_type_def node.  This is what a leaf pointed-to type node
/// means.
///
/// Otherwise, if the pointed-to type node of @ref reference_type_def
/// is *NOT* a @ref reference_type_def node, then just return the
/// pointed-to type node.
///
/// And if the type node considered is not a @ref reference_type_def
/// node, then just return it.
///
/// @return the leaf pointed-to type node of a @p type.
const type_base*
peel_reference_type(const type_base* type)
{
  const reference_type_def* t = is_reference_type(type);
  if (!t)
    return type;

  return peel_reference_type(t->get_pointed_to_type()).get();
}

/// Return the leaf element type of an array.
///
/// If the element type is itself an array, then recursively return
/// the element type of that array itself.
///
/// @param type the array type to consider.  If this is not an array
/// type, this type is returned by the function.
///
/// @return the leaf element type of the array @p type, or, if it's
/// not an array type, then just return @p.
const type_base_sptr
peel_array_type(const type_base_sptr& type)
{
  const array_type_def_sptr t = is_array_type(type);
  if (!t)
    return type;

  return peel_array_type(t->get_element_type());
}

/// Return the leaf element type of an array.
///
/// If the element type is itself an array, then recursively return
/// the element type of that array itself.
///
/// @param type the array type to consider.  If this is not an array
/// type, this type is returned by the function.
///
/// @return the leaf element type of the array @p type, or, if it's
/// not an array type, then just return @p.
const type_base*
peel_array_type(const type_base* type)
{
  const array_type_def* t = is_array_type(type);
  if (!t)
    return type;

  return peel_array_type(t->get_element_type()).get();
}

/// Return the leaf underlying type of a qualified type.
///
/// If the underlying type is itself a qualified type, then
/// recursively return the first underlying type of that qualified
/// type to return the first underlying type that is not a qualified type.
///
/// If the underlying type is NOT a qualified type, then just return
/// that underlying type.
///
/// @param type the qualified type to consider.
///
/// @return the leaf underlying type.
const type_base*
peel_qualified_type(const type_base* type)
{
  const qualified_type_def* t = is_qualified_type(type);
  if (!t)
    return type;

  return peel_qualified_type(t->get_underlying_type().get());
}

/// Return the leaf underlying type of a qualified type.
///
/// If the underlying type is itself a qualified type, then
/// recursively return the first underlying type of that qualified
/// type to return the first underlying type that is not a qualified type.
///
/// If the underlying type is NOT a qualified type, then just return
/// that underlying type.
///
/// @param type the qualified type to consider.
///
/// @return the leaf underlying type.
const type_base_sptr
peel_qualified_type(const type_base_sptr& type)
{
  const qualified_type_def_sptr t = is_qualified_type(type);
  if (!t)
    return type;

  return peel_qualified_type(t->get_underlying_type());
}

/// Test if a given qualified type is const.
///
/// @pram t the qualified type to consider.
///
/// @return true iff @p t is a const qualified type.
bool
is_const_qualified_type(const qualified_type_def_sptr& t)
{
  if (!t)
    return false;

  if (t->get_cv_quals() == qualified_type_def::CV_CONST)
    return true;

  return false;
}

/// Test if a given type is const-qualified.
///
/// @pram t the type to consider.
///
/// @return true iff @p t is a const qualified type.
bool
is_const_qualified_type(const type_base_sptr& t)
{
  qualified_type_def_sptr q = is_qualified_type(t);
  if (!q)
    return false;
  return is_const_qualified_type(q);
}

/// If a qualified type is const, then return its underlying type.
///
/// @param q the qualified type to consider.
///
/// @return the underlying type of @p q if it's a const-qualified
/// type, otherwise, return @p q itself.
type_base_sptr
peel_const_qualified_type(const qualified_type_def_sptr& q)
{
  if (!q)
    return q;

  if (is_const_qualified_type(q))
    return q->get_underlying_type();

  return q;
}

/// Return the leaf underlying type of a qualified or typedef type.
///
/// If the underlying type is itself a qualified or typedef type, then
/// recursively return the first underlying type of that qualified or
/// typedef type to return the first underlying type that is not a
/// qualified or typedef type.
///
/// If the underlying type is NOT a qualified nor a typedef type, then
/// just return that underlying type.
///
/// @param type the qualified or typedef type to consider.
///
/// @return the leaf underlying type.
type_base*
peel_qualified_or_typedef_type(const type_base* type)
{
  while (is_typedef(type) || is_qualified_type(type))
    {
      if (const typedef_decl* t = is_typedef(type))
    type = peel_typedef_type(t);

      if (const qualified_type_def* t = is_qualified_type(type))
    type = peel_qualified_type(t);
    }

  return const_cast<type_base*>(type);
}

/// Return the leaf underlying type of a qualified or typedef type.
///
/// If the underlying type is itself a qualified or typedef type, then
/// recursively return the first underlying type of that qualified or
/// typedef type to return the first underlying type that is not a
/// qualified or typedef type.
///
/// If the underlying type is NOT a qualified nor a typedef type, then
/// just return that underlying type.
///
/// @param type the qualified or typedef type to consider.
///
/// @return the leaf underlying type.
type_base_sptr
peel_qualified_or_typedef_type(const type_base_sptr &t)
{
  type_base_sptr type = t;
  while (is_typedef(type) || is_qualified_type(type))
    {
      if (typedef_decl_sptr t = is_typedef(type))
    type = peel_typedef_type(t);

      if (qualified_type_def_sptr t = is_qualified_type(type))
    type = peel_qualified_type(t);
    }

  return type;
}

/// Return the leaf underlying or pointed-to type node of a @ref
/// typedef_decl, @ref pointer_type_def, @ref reference_type_def,
/// or @ref array_type_def node.
///
/// @param type the type to peel.
///
/// @return the leaf underlying or pointed-to type node of @p type.
type_base_sptr
peel_typedef_pointer_or_reference_type(const type_base_sptr type)
{
  type_base_sptr typ = type;
  while (is_typedef(typ)
     || is_pointer_type(typ)
     || is_reference_type(typ)
     || is_array_type(typ))
    {
      if (typedef_decl_sptr t = is_typedef(typ))
    typ = peel_typedef_type(t);

      if (pointer_type_def_sptr t = is_pointer_type(typ))
    typ = peel_pointer_type(t);

      if (reference_type_def_sptr t = is_reference_type(typ))
    typ = peel_reference_type(t);

      if (const array_type_def_sptr t = is_array_type(typ))
    typ = peel_array_type(t);
    }

  return typ;
}

/// Return the leaf underlying or pointed-to type node of a @ref
/// typedef_decl, @ref pointer_type_def or @ref reference_type_def
/// node.
///
/// @param type the type to peel.
///
/// @return the leaf underlying or pointed-to type node of @p type.
type_base*
peel_typedef_pointer_or_reference_type(const type_base* type)
{
  while (is_typedef(type)
     || is_pointer_type(type)
     || is_reference_type(type)
     || is_array_type(type))
    {
      if (const typedef_decl* t = is_typedef(type))
    type = peel_typedef_type(t);

      if (const pointer_type_def* t = is_pointer_type(type))
    type = peel_pointer_type(t);

      if (const reference_type_def* t = is_reference_type(type))
    type = peel_reference_type(t);

      if (const array_type_def* t = is_array_type(type))
    type = peel_array_type(t);
    }

  return const_cast<type_base*>(type);
}

/// Return the leaf underlying or pointed-to type node of a @ref
/// typedef_decl, @ref pointer_type_def or @ref reference_type_def
/// node.
///
/// @param type the type to peel.
///
/// @return the leaf underlying or pointed-to type node of @p type.
type_base*
peel_typedef_pointer_or_reference_type(const type_base* type,
                       bool peel_qual_type)
{
  while (is_typedef(type)
     || is_pointer_type(type)
     || is_reference_type(type)
     || is_array_type(type)
     || (peel_qual_type && is_qualified_type(type)))
    {
      if (const typedef_decl* t = is_typedef(type))
    type = peel_typedef_type(t);

      if (const pointer_type_def* t = is_pointer_type(type))
    type = peel_pointer_type(t);

      if (const reference_type_def* t = is_reference_type(type))
    type = peel_reference_type(t);

      if (const array_type_def* t = is_array_type(type))
    type = peel_array_type(t);

      if (peel_qual_type)
    if (const qualified_type_def* t = is_qualified_type(type))
      type = peel_qualified_type(t);
    }

  return const_cast<type_base*>(type);
}

/// Return the leaf underlying or pointed-to type node of a, @ref
/// pointer_type_def, @ref reference_type_def or @ref
/// qualified_type_def type node.
///
/// @param type the type to peel.
///
/// @param peel_qualified_type if true, also peel qualified types.
///
/// @return the leaf underlying or pointed-to type node of @p type.
type_base*
peel_pointer_or_reference_type(const type_base *type,
                   bool peel_qual_type)
{
  while (is_pointer_type(type)
     || is_reference_type(type)
     || is_array_type(type)
     || (peel_qual_type && is_qualified_type(type)))
    {
      if (const pointer_type_def* t = is_pointer_type(type))
    type = peel_pointer_type(t);

      if (const reference_type_def* t = is_reference_type(type))
    type = peel_reference_type(t);

      if (const array_type_def* t = is_array_type(type))
    type = peel_array_type(t);

      if (peel_qual_type)
    if (const qualified_type_def* t = is_qualified_type(type))
      type = peel_qualified_type(t);
    }

  return const_cast<type_base*>(type);
}

/// Clone an array type.
///
/// Note that the element type of the new array is shared witht the
/// old one.
///
/// @param array the array type to clone.
///
/// @return a newly built array type.  Note that it needs to be added
/// to a scope (e.g, using add_decl_to_scope) for its lifetime to be
/// bound to the one of that scope.  Otherwise, its lifetime is bound
/// to the lifetime of its containing shared pointer.
array_type_def_sptr
clone_array(const array_type_def_sptr& array)
{
  vector<array_type_def::subrange_sptr> subranges;

  for (vector<array_type_def::subrange_sptr>::const_iterator i =
     array->get_subranges().begin();
       i != array->get_subranges().end();
       ++i)
    {
      array_type_def::subrange_sptr subrange
    (new array_type_def::subrange_type(array->get_environment(),
                       (*i)->get_name(),
                       (*i)->get_lower_bound(),
                       (*i)->get_upper_bound(),
                       (*i)->get_underlying_type(),
                       (*i)->get_location(),
                       (*i)->get_language()));
      subrange->is_non_finite((*i)->is_non_finite());
      if (scope_decl *scope = (*i)->get_scope())
    add_decl_to_scope(subrange, scope);
      subranges.push_back(subrange);
    }

  array_type_def_sptr result
    (new array_type_def(array->get_element_type(),
            subranges, array->get_location()));

  return result;
}

/// Clone a typedef type.
///
/// Note that the underlying type of the newly constructed typedef is
/// shared with the old one.
///
/// @param t the typedef to clone.
///
/// @return the newly constructed typedef.  Note that it needs to be
/// added to a scope (e.g, using add_decl_to_scope) for its lifetime
/// to be bound to the one of that scope.  Otherwise, its lifetime is
/// bound to the lifetime of its containing shared pointer.
typedef_decl_sptr
clone_typedef(const typedef_decl_sptr& t)
{
  if (!t)
    return t;

  typedef_decl_sptr result
    (new typedef_decl(t->get_name(), t->get_underlying_type(),
              t->get_location(), t->get_linkage_name(),
              t->get_visibility()));
  return result;
}

/// Clone a qualifiend type.
///
/// Note that underlying type of the newly constructed qualified type
/// is shared with the old one.
///
/// @param t the qualified type to clone.
///
/// @return the newly constructed qualified type.  Note that it needs
/// to be added to a scope (e.g, using add_decl_to_scope) for its
/// lifetime to be bound to the one of that scope.  Otherwise, its
/// lifetime is bound to the lifetime of its containing shared
/// pointer.
qualified_type_def_sptr
clone_qualified_type(const qualified_type_def_sptr& t)
{
  if (!t)
    return t;

  qualified_type_def_sptr result
    (new qualified_type_def(t->get_underlying_type(),
                t->get_cv_quals(), t->get_location()));

  return result;
}

/// Clone a typedef, an array or a qualified tree.
///
/// @param type the typedef, array or qualified tree to clone.  any
/// order.
///
/// @return the cloned type, or NULL if @type was neither a typedef,
/// array nor a qualified type.
static type_base_sptr
clone_typedef_array_qualified_type(type_base_sptr type)
{
  if (!type)
    return type;

  scope_decl* scope = is_decl(type) ? is_decl(type)->get_scope() : 0;
  type_base_sptr result;

  if (typedef_decl_sptr t = is_typedef(type))
    result = clone_typedef(is_typedef(t));
  else if (qualified_type_def_sptr t = is_qualified_type(type))
    result = clone_qualified_type(t);
  else if (array_type_def_sptr t = is_array_type(type))
    result = clone_array(t);
  else
    return type_base_sptr();

  if (scope)
    add_decl_to_scope(is_decl(result), scope);

  return result;
}

/// Clone a type tree made of an array or a typedef of array.
///
/// Note that this can be a tree which root node is a typedef an which
/// sub-tree can be any arbitrary combination of typedef, qualified
/// type and arrays.
///
/// @param t the array or typedef of qualified array to consider.
///
/// @return a clone of @p t.
type_base_sptr
clone_array_tree(const type_base_sptr t)
{
  ABG_ASSERT(is_typedef_of_array(t) || is_array_type(t));

  scope_decl* scope = is_decl(t)->get_scope();
  type_base_sptr result = clone_typedef_array_qualified_type(t);
  ABG_ASSERT(is_typedef_of_array(result) || is_array_type(result));

  type_base_sptr subtree;
  if (typedef_decl_sptr type = is_typedef(result))
    {
      type_base_sptr s =
    clone_typedef_array_qualified_type(type->get_underlying_type());
      if (s)
    {
      subtree = s;
      type->set_underlying_type(subtree);
    }
    }
  else if (array_type_def_sptr type = is_array_type(result))
    {
      type_base_sptr s =
    clone_typedef_array_qualified_type(type->get_element_type());
      if (s)
    {
      subtree = s;
      type->set_element_type(subtree);
    }
    }
  add_decl_to_scope(is_decl(subtree), scope);

  for (;;)
    {
      if (typedef_decl_sptr t = is_typedef(subtree))
    {
      type_base_sptr s =
        clone_typedef_array_qualified_type(t->get_underlying_type());
      if (s)
        {
          scope_decl* scope =
        is_decl(t->get_underlying_type())->get_scope();
          ABG_ASSERT(scope);
          add_decl_to_scope(is_decl(s), scope);
          t->set_underlying_type (s);
          subtree = s;
        }
      else
        break;
    }
      else if (qualified_type_def_sptr t = is_qualified_type(subtree))
    {
      type_base_sptr s =
        clone_typedef_array_qualified_type(t->get_underlying_type());
      if (s)
        {
          scope_decl* scope =
        is_decl(t->get_underlying_type())->get_scope();
          ABG_ASSERT(scope);
          add_decl_to_scope(is_decl(s), scope);
          t->set_underlying_type(s);
          subtree = s;
        }
      else
        break;
    }
      else if (array_type_def_sptr t = is_array_type(subtree))
    {
      type_base_sptr e = t->get_element_type();
      if (is_typedef(e) || is_qualified_type(e))
        {
          type_base_sptr s =
        clone_typedef_array_qualified_type(e);
          if (s)
        {
          scope_decl* scope = is_decl(e)->get_scope();
          ABG_ASSERT(scope);
          add_decl_to_scope(is_decl(s), scope);
          t->set_element_type(s);
        }
          else
        break;
        }
      break;
    }
      else
    break;
    }
  return result;
}

/// Update the qualified name of a given sub-tree.
///
/// @param d the sub-tree for which to update the qualified name.
static void
update_qualified_name(decl_base * d)
{
  ::qualified_name_setter setter;
  d->traverse(setter);
}

/// Update the qualified name of a given sub-tree.
///
/// @param d the sub-tree for which to update the qualified name.
static void
update_qualified_name(decl_base_sptr d)
{return update_qualified_name(d.get());}

// <scope_decl stuff>

/// Hash a type by returning the pointer value of its canonical type.
///
/// @param l the type to hash.
///
/// @return the the pointer value of the canonical type of @p l.
size_t
canonical_type_hash::operator()(const type_base_sptr& l) const
{return operator()(l.get());}

/// Hash a (canonical) type by returning its pointer value
///
/// @param l the canonical type to hash.
///
/// @return the pointer value of the canonical type of @p l.
size_t
canonical_type_hash::operator()(const type_base *l) const
{return reinterpret_cast<size_t>(l);}

struct scope_decl::priv
{
  declarations members_;
  declarations sorted_members_;
  type_base_sptrs_type member_types_;
  type_base_sptrs_type sorted_member_types_;
  scopes member_scopes_;
  canonical_type_sptr_set_type canonical_types_;
  type_base_sptrs_type sorted_canonical_types_;
  bool clear_sorted_member_types_cache_ = false;
}; // end struct scope_decl::priv

/// Constructor of the @ref scope_decl type.
///
/// @param the environment to use for the new instance.
///
/// @param the name of the scope decl.
///
/// @param locus the source location where the scope_decl is defined.
///
/// @param vis the visibility of the declaration.
scope_decl::scope_decl(const environment& env,
               const string& name,
               const location& locus,
               visibility vis)
  : type_or_decl_base(env, ABSTRACT_SCOPE_DECL|ABSTRACT_DECL_BASE),
    decl_base(env, name, locus, /*mangled_name=*/name, vis),
    priv_(new priv)
{}

/// Constructor of the @ref scope_decl type.
///
/// @param the environment to use for the new instance.
///
/// @param l the source location where the scope_decl is defined.
///
/// @param vis the visibility of the declaration.
scope_decl::scope_decl(const environment& env, location& l)
  : type_or_decl_base(env, ABSTRACT_SCOPE_DECL|ABSTRACT_DECL_BASE),
    decl_base(env, "", l),
    priv_(new priv)
{}

/// @eturn the set of canonical types of the the current scope.
canonical_type_sptr_set_type&
scope_decl::get_canonical_types()
{return priv_->canonical_types_;}

/// @eturn the set of canonical types of the the current scope.
const canonical_type_sptr_set_type&
scope_decl::get_canonical_types() const
{return const_cast<scope_decl*>(this)->get_canonical_types();}

/// Return a vector of sorted canonical types of the current scope.
///
/// The types are sorted "almost topologically". That means, they are
/// sorted using the lexicographic order of the string representing
/// the location their definition point.  If a type doesn't have a
/// location, then its pretty representation is used.
///
/// @return a vector of sorted canonical types of the current scope.
const type_base_sptrs_type&
scope_decl::get_sorted_canonical_types() const
{
  if (priv_->sorted_canonical_types_.empty())
    {
      for (canonical_type_sptr_set_type::const_iterator e =
         get_canonical_types().begin();
       e != get_canonical_types().end();
       ++e)
    priv_->sorted_canonical_types_.push_back(*e);

      type_topo_comp comp;
      std::stable_sort(priv_->sorted_canonical_types_.begin(),
               priv_->sorted_canonical_types_.end(),
               comp);
    }
  return priv_->sorted_canonical_types_;
}

/// Getter for the member declarations carried by the current @ref
/// scope_decl.
///
/// @return the member declarations carried by the current @ref
/// scope_decl.
const scope_decl::declarations&
scope_decl::get_member_decls() const
{return priv_->members_;}

/// Getter for the member declarations carried by the current @ref
/// scope_decl.
///
/// @return the member declarations carried by the current @ref
/// scope_decl.
scope_decl::declarations&
scope_decl::get_member_decls()
{return priv_->members_;}

/// Getter for the sorted member declarations carried by the current
/// @ref scope_decl.
///
/// @return the sorted member declarations carried by the current @ref
/// scope_decl.  The declarations are sorted topologically.
const scope_decl::declarations&
scope_decl::get_sorted_member_decls() const
{
  decl_topo_comp comp;
  if (priv_->sorted_members_.empty())
    {
      for (declarations::const_iterator i = get_member_decls().begin();
       i != get_member_decls().end();
       ++i)
    priv_->sorted_members_.push_back(*i);

      std::stable_sort(priv_->sorted_members_.begin(),
               priv_->sorted_members_.end(),
               comp);
    }
  return priv_->sorted_members_;
}

/// Getter for the number of anonymous classes contained in this
/// scope.
///
/// @return the number of anonymous classes contained in this scope.
size_t
scope_decl::get_num_anonymous_member_classes() const
{
  int result = 0;
  for (declarations::const_iterator it = get_member_decls().begin();
       it != get_member_decls().end();
       ++it)
    if (class_decl_sptr t = is_class_type(*it))
      if (t->get_is_anonymous())
    ++result;

  return result;
}

/// Getter for the number of anonymous unions contained in this
/// scope.
///
/// @return the number of anonymous unions contained in this scope.
size_t
scope_decl::get_num_anonymous_member_unions() const
{
  int result = 0;
  for (declarations::const_iterator it = get_member_decls().begin();
       it != get_member_decls().end();
       ++it)
    if (union_decl_sptr t = is_union_type(*it))
      if (t->get_is_anonymous())
    ++result;

  return result;
}

/// Getter for the number of anonymous enums contained in this
/// scope.
///
/// @return the number of anonymous enums contained in this scope.
size_t
scope_decl::get_num_anonymous_member_enums() const
{
  int result = 0;
  for (declarations::const_iterator it = get_member_decls().begin();
       it != get_member_decls().end();
       ++it)
    if (enum_type_decl_sptr t = is_enum_type(*it))
      if (t->get_is_anonymous())
    ++result;

  return result;
}

/// Getter for the scopes carried by the current scope.
///
/// @return the scopes carried by the current scope.
scope_decl::scopes&
scope_decl::get_member_scopes()
{return priv_->member_scopes_;}

/// Getter for the scopes carried by the current scope.
///
/// @return the scopes carried by the current scope.
const scope_decl::scopes&
scope_decl::get_member_scopes() const
{return priv_->member_scopes_;}

/// Test if the current scope is empty.
///
/// @return true iff the current scope is empty.
bool
scope_decl::is_empty() const
{
  return (get_member_decls().empty()
      && get_canonical_types().empty());
}

/// Set the translation unit of a decl
///
/// It also perform some IR integrity checks.
///
/// This is a sub-routine of scope_decl::{insert,add}_member_decl.
///
/// @param decl the decl to set the translation unit for.
///
/// @param tu the translation unit to set.
static void
maybe_set_translation_unit(const decl_base_sptr& decl,
               translation_unit*     tu)
{
  ABG_ASSERT(tu);

  if (translation_unit* existing_tu = decl->get_translation_unit())
    // The decl already belongs to a translation unit.
    // Either:
    //
    //   1/ it's a unique type, in which case we should not add it to
    // any translation unique since unique types are "logically"
    // supposed to belong to no translation unit in particular, as
    // they are unique.
    //
    // 2/ or the decl was already added to this translation unit.
    ABG_ASSERT(tu == existing_tu || is_unique_type(is_type(decl)));
  else
    decl->set_translation_unit(tu);
}

/// Add a member decl to this scope.  Note that user code should not
/// use this, but rather use add_decl_to_scope.
///
/// Note that this function updates the qualified name of the member
/// decl that is added.  It also sets the scope of the member.  Thus,
/// it ABG_ASSERTs that member should not have its scope set, prior to
/// calling this function.
///
/// @param member the new member decl to add to this scope.
decl_base_sptr
scope_decl::add_member_decl(const decl_base_sptr& member)
{
  ABG_ASSERT(!has_scope(member));

  member->set_scope(this);
  priv_->members_.push_back(member);
  if (is_type(member))
    {
      priv_->member_types_.push_back(is_type(member));
      priv_->clear_sorted_member_types_cache_ = true;
    }

  if (scope_decl_sptr m = dynamic_pointer_cast<scope_decl>(member))
    priv_->member_scopes_.push_back(m);

  update_qualified_name(member);

  if (translation_unit* tu = get_translation_unit())
    maybe_set_translation_unit(member, tu);

  maybe_update_types_lookup_map(member);

  return member;
}

/// Get the member types of this @ref scope_decl.
///
/// @return a vector of the member types of this ref class_or_union.
const type_base_sptrs_type&
scope_decl::get_member_types() const
{return priv_->member_types_;}

/// Find a member type of a given name, inside the current @ref
/// scope_decl.
///
/// @param name the name of the member type to look for.
///
/// @return a pointer to the @ref type_base that represents the member
/// type of name @p name, for the current scope.
type_base_sptr
scope_decl::find_member_type(const string& name) const
{
  for (auto t : get_member_types())
    if (get_type_name(t, /*qualified*/false) == name)
      return t;
  return type_base_sptr();
}

/// Insert a member type.
///
/// @param t the type to insert in the @ref scope_decl type.
///
/// @param an iterator right before which @p t has to be inserted.
void
scope_decl::insert_member_type(type_base_sptr t,
                   declarations::iterator before)
{
  decl_base_sptr d = get_type_declaration(t);
  ABG_ASSERT(d);
  ABG_ASSERT(!has_scope(d));

  priv_->member_types_.push_back(t);
  priv_->clear_sorted_member_types_cache_= true;
  insert_member_decl(d, before);
}

/// Add a member type to the current instance of class_or_union.
///
/// @param t the member type to add.  It must not have been added to a
/// scope, otherwise this will violate an ABG_ASSERTion.
void
scope_decl::add_member_type(type_base_sptr t)
{insert_member_type(t, get_member_decls().end());}

/// Add a member type to the current instance of class_or_union.
///
/// @param t the type to be added as a member type to the current
/// instance of class_or_union.  An instance of class_or_union::member_type
/// will be created out of @p t and and added to the the class.
///
/// @param a the access specifier for the member type to be created.
type_base_sptr
scope_decl::add_member_type(type_base_sptr t, access_specifier a)
{
  decl_base_sptr d = get_type_declaration(t);
  ABG_ASSERT(d);
  ABG_ASSERT(!is_member_decl(d));
  add_member_type(t);
  set_member_access_specifier(d, a);
  return t;
}

/// Remove a member type from the current @ref class_or_union scope.
///
/// @param t the type to remove.
void
scope_decl::remove_member_type(type_base_sptr t)
{
  for (auto i = priv_->member_types_.begin();
       i != priv_->member_types_.end();
       ++i)
    {
      if (*((*i)) == *t)
    {
      priv_->member_types_.erase(i);
      return;
    }
    }
}

/// Get the sorted member types of this @ref scope_decl
///
/// @return a vector of the sorted member types of this ref
/// class_or_union.
const type_base_sptrs_type&
scope_decl::get_sorted_member_types() const
{
  if (priv_->clear_sorted_member_types_cache_)
    {
      priv_->sorted_member_types_.clear();
      priv_->clear_sorted_member_types_cache_ = false;
    }

  if (priv_->sorted_member_types_.empty())
    {
      unordered_set<type_base_sptr> canonical_pointer_types;
      for (auto t : get_member_types())
    {
      if (is_non_canonicalized_type(t))
        priv_->sorted_member_types_.push_back(t);
      else if (auto c = t->get_canonical_type())
        canonical_pointer_types.insert(c);
      else
        canonical_pointer_types.insert(t);
    }

      for (auto t : canonical_pointer_types)
    priv_->sorted_member_types_.push_back(t);

      type_topo_comp comp;
      std::stable_sort(priv_->sorted_member_types_.begin(),
               priv_->sorted_member_types_.end(),
               comp);
    }

  const ir::environment& env = get_environment();
  if (!env.canonicalization_started() && !env.canonicalization_is_done())
    priv_->clear_sorted_member_types_cache_ = true;

  return priv_->sorted_member_types_;
}

/// Insert a member decl to this scope, right before an element
/// pointed to by a given iterator.  Note that user code should not
/// use this, but rather use insert_decl_into_scope.
///
/// Note that this function updates the qualified name of the inserted
/// member.
///
/// @param member the new member decl to add to this scope.
///
/// @param before an interator pointing to the element before which
/// the new member should be inserted.
decl_base_sptr
scope_decl::insert_member_decl(decl_base_sptr member,
                   declarations::iterator before)
{
  ABG_ASSERT(!member->get_scope());

  member->set_scope(this);
  priv_->members_.insert(before, member);

  if (scope_decl_sptr m = dynamic_pointer_cast<scope_decl>(member))
   priv_-> member_scopes_.push_back(m);

  update_qualified_name(member);

  if (translation_unit* tu = get_translation_unit())
    maybe_set_translation_unit(member, tu);

  maybe_update_types_lookup_map(member);

  return member;
}

/// Remove a declaration from the current scope.
///
/// @param member the declaration to remove from the scope.
void
scope_decl::remove_member_decl(decl_base_sptr member)
{
  for (declarations::iterator i = priv_->members_.begin();
       i != priv_->members_.end();
       ++i)
    {
      if (**i == *member)
    {
      priv_->members_.erase(i);
      // Do not access i after this point as it's invalided by the
      // erase call.
      break;
    }
    }

  scope_decl_sptr scope = dynamic_pointer_cast<scope_decl>(member);
  if (scope)
    {
      for (scopes::iterator i = priv_->member_scopes_.begin();
       i != priv_->member_scopes_.end();
       ++i)
    {
      if (**i == *member)
        {
          priv_->member_scopes_.erase(i);
          break;
        }
    }
    }

  member->set_scope(nullptr);
  member->set_translation_unit(nullptr);
}

/// Compares two instances of @ref scope_decl.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const scope_decl& l, const scope_decl& r, change_kind* k)
{
  bool result = true;

  if (!l.decl_base::operator==(r))
    {
      result = false;
      if (k)
    *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }

  scope_decl::declarations::const_iterator i, j;
  for (i = l.get_member_decls().begin(), j = r.get_member_decls().begin();
       i != l.get_member_decls().end() && j != r.get_member_decls().end();
       ++i, ++j)
    {
      if (**i != **j)
    {
      result = false;
      if (k)
        {
          *k |= SUBTYPE_CHANGE_KIND;
          break;
        }
      else
        ABG_RETURN_FALSE;
    }
    }

  if (i != l.get_member_decls().end() || j != r.get_member_decls().end())
    {
      result = false;
      if (k)
    *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }

  ABG_RETURN(result);
}

/// Return true iff both scopes have the same names and have the same
/// member decls.
///
/// This function doesn't check for equality of the scopes of its
/// arguments.
bool
scope_decl::operator==(const decl_base& o) const
{
  const scope_decl* other = dynamic_cast<const scope_decl*>(&o);
  if (!other)
    return false;

  return equals(*this, *other, 0);
}

/// Equality operator for @ref scope_decl_sptr.
///
/// @param l the left hand side operand of the equality operator.
///
/// @pram r the right hand side operand of the equalify operator.
///
/// @return true iff @p l equals @p r.
bool
operator==(const scope_decl_sptr& l, const scope_decl_sptr& r)
{
  if (!!l != !!r)
    return false;
  if (l.get() == r.get())
    return true;
  return *l == *r;
}

/// Inequality operator for @ref scope_decl_sptr.
///
/// @param l the left hand side operand of the equality operator.
///
/// @pram r the right hand side operand of the equalify operator.
///
/// @return true iff @p l equals @p r.
bool
operator!=(const scope_decl_sptr& l, const scope_decl_sptr& r)
{return !operator==(l, r);}

/// Find a member of the current scope and return an iterator on it.
///
/// @param decl the scope member to find.
///
/// @param i the iterator to set to the member @p decl.  This is set
/// iff the function returns true.
///
/// @return true if the member decl was found, false otherwise.
bool
scope_decl::find_iterator_for_member(const decl_base* decl,
                     declarations::iterator& i)
{
  if (!decl)
    return false;

  if (get_member_decls().empty())
    {
      i = get_member_decls().end();
      return false;
    }

  for (declarations::iterator it = get_member_decls().begin();
       it != get_member_decls().end();
       ++it)
    {
      if ((*it).get() == decl)
    {
      i = it;
      return true;
    }
    }

  return false;
}

/// Find a member of the current scope and return an iterator on it.
///
/// @param decl the scope member to find.
///
/// @param i the iterator to set to the member @p decl.  This is set
/// iff the function returns true.
///
/// @return true if the member decl was found, false otherwise.
bool
scope_decl::find_iterator_for_member(const decl_base_sptr decl,
                     declarations::iterator& i)
{return find_iterator_for_member(decl.get(), i);}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance of scope_decl
/// and on its member nodes.
///
/// @return true if the traversal of the tree should continue, false
/// otherwise.
bool
scope_decl::traverse(ir_node_visitor &v)
{
  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      for (scope_decl::declarations::const_iterator i =
         get_member_decls().begin();
       i != get_member_decls ().end();
       ++i)
    if (!(*i)->traverse(v))
      break;
      visiting(false);
    }
  return v.visit_end(this);
}

scope_decl::~scope_decl()
{}

/// Appends a declaration to a given scope, if the declaration
/// doesn't already belong to one and if the declaration is not for a
/// type that is supposed to be unique.
///
/// @param decl the declaration to add to the scope
///
/// @param scope the scope to append the declaration to
decl_base_sptr
add_decl_to_scope(decl_base_sptr decl, scope_decl* scope)
{
  if (!scope)
    return decl;

  if (scope && decl && !decl->get_scope())
    decl = scope->add_member_decl(decl);

  return decl;
}

/// Appends a declaration to a given scope, if the declaration doesn't
/// already belong to a scope.
///
/// @param decl the declaration to add append to the scope
///
/// @param scope the scope to append the decl to
decl_base_sptr
add_decl_to_scope(decl_base_sptr decl, const scope_decl_sptr& scope)
{return add_decl_to_scope(decl, scope.get());}

/// Remove a given decl from its scope
///
/// @param decl the decl to remove from its scope.
void
remove_decl_from_scope(decl_base_sptr decl)
{
  if (!decl)
    return;

  scope_decl* scope = decl->get_scope();
  scope->remove_member_decl(decl);
}

/// Inserts a declaration into a given scope, before a given IR child
/// node of the scope.
///
/// @param decl the declaration to insert into the scope.
///
/// @param before an iterator pointing to the child IR node before
/// which to insert the declaration.
///
/// @param scope the scope into which to insert the declaration.
decl_base_sptr
insert_decl_into_scope(decl_base_sptr decl,
               scope_decl::declarations::iterator before,
               scope_decl* scope)
{
  if (scope && decl && !decl->get_scope())
    {
      decl_base_sptr d = scope->insert_member_decl(decl, before);
      decl = d;
    }
  return decl;
}

/// Inserts a declaration into a given scope, before a given IR child
/// node of the scope.
///
/// @param decl the declaration to insert into the scope.
///
/// @param before an iterator pointing to the child IR node before
/// which to insert the declaration.
///
/// @param scope the scope into which to insert the declaration.
decl_base_sptr
insert_decl_into_scope(decl_base_sptr decl,
               scope_decl::declarations::iterator before,
               scope_decl_sptr scope)
{return insert_decl_into_scope(decl, before, scope.get());}

/// Constructor of the @ref global_scope type.
///
/// @param tu the translation unit the scope belongs to.
global_scope::global_scope(translation_unit *tu)
  : type_or_decl_base(tu->get_environment(),
              GLOBAL_SCOPE_DECL
              | ABSTRACT_DECL_BASE
              | ABSTRACT_SCOPE_DECL),
    decl_base(tu->get_environment(), "", location()),
    scope_decl(tu->get_environment(), "", location()),
    translation_unit_(tu)
{
  runtime_type_instance(this);
}

/// return the global scope as seen by a given declaration.
///
/// @param decl the declaration to consider.
///
/// @return the global scope of the decl, or a null pointer if the
/// decl is not yet added to a translation_unit.
const global_scope*
get_global_scope(const decl_base& decl)
{
  if (const global_scope* s = dynamic_cast<const global_scope*>(&decl))
    return s;

  scope_decl* scope = decl.get_scope();
  while (scope && !dynamic_cast<global_scope*>(scope))
    scope = scope->get_scope();

  return scope ? dynamic_cast<global_scope*> (scope) : 0;
}

/// return the global scope as seen by a given declaration.
///
/// @param decl the declaration to consider.
///
/// @return the global scope of the decl, or a null pointer if the
/// decl is not yet added to a translation_unit.
const global_scope*
get_global_scope(const decl_base* decl)
{return get_global_scope(*decl);}

/// Return the global scope as seen by a given declaration.
///
/// @param decl the declaration to consider.
///
/// @return the global scope of the decl, or a null pointer if the
/// decl is not yet added to a translation_unit.
const global_scope*
get_global_scope(const shared_ptr<decl_base> decl)
{return get_global_scope(decl.get());}

/// Return the a scope S containing a given declaration and that is
/// right under a given scope P.
///
/// Note that @p scope must come before @p decl in topological
/// order.
///
/// @param decl the decl for which to find a scope.
///
/// @param scope the scope under which the resulting scope must be.
///
/// @return the resulting scope.
const scope_decl*
get_top_most_scope_under(const decl_base* decl,
             const scope_decl* scope)
{
  if (!decl)
    return 0;

  if (scope == 0)
    return get_global_scope(decl);

  // Handle the case where decl is a scope itself.
  const scope_decl* s = dynamic_cast<const scope_decl*>(decl);
  if (!s)
    s = decl->get_scope();

  if (is_global_scope(s))
    return scope;

  // Here, decl is in the scope 'scope', or decl and 'scope' are the
  // same.  The caller needs to be prepared to deal with this case.
  if (s == scope)
    return s;

  while (s && !is_global_scope(s) && s->get_scope() != scope)
    s = s->get_scope();

  if (!s || is_global_scope(s))
    // SCOPE must come before decl in topological order, but I don't
    // know how to ensure that ...
    return scope;
  ABG_ASSERT(s);

  return s;
}

/// Return the a scope S containing a given declaration and that is
/// right under a given scope P.
///
/// @param decl the decl for which to find a scope.
///
/// @param scope the scope under which the resulting scope must be.
///
/// @return the resulting scope.
const scope_decl*
get_top_most_scope_under(const decl_base_sptr decl,
             const scope_decl* scope)
{return get_top_most_scope_under(decl.get(), scope);}

/// Return the a scope S containing a given declaration and that is
/// right under a given scope P.
///
/// @param decl the decl for which to find a scope.
///
/// @param scope the scope under which the resulting scope must be.
///
/// @return the resulting scope.
const scope_decl*
get_top_most_scope_under(const decl_base_sptr decl,
             const scope_decl_sptr scope)
{return get_top_most_scope_under(decl, scope.get());}

// </scope_decl stuff>


/// Get the string representation of a CV qualifier bitmap.
///
/// @param cv_quals the bitmap of CV qualifiers to consider.
///
/// @return the string representation.
string
get_string_representation_of_cv_quals(const qualified_type_def::CV cv_quals)
{
  string repr;
  if (cv_quals & qualified_type_def::CV_RESTRICT)
    repr = "restrict";
  if (cv_quals & qualified_type_def::CV_CONST)
    {
      if (!repr.empty())
    repr += ' ';
      repr += "const";
    }
  if (cv_quals & qualified_type_def::CV_VOLATILE)
    {
      if (!repr.empty())
    repr += ' ';
      repr += "volatile";
    }
  return repr;
}

/// Build and return a copy of the name of an ABI artifact that is
/// either a type or a decl.
///
/// @param tod the ABI artifact to get the name for.
///
/// @param qualified if yes, return the qualified name of @p tod;
/// otherwise, return the non-qualified name;
///
/// @return the name of @p tod.
string
get_name(const type_or_decl_base *tod, bool qualified)
{
  string result;

  type_or_decl_base* a = const_cast<type_or_decl_base*>(tod);

  if (type_base* t = dynamic_cast<type_base*>(a))
    result = get_type_name(t, qualified);
  else if (decl_base *d = dynamic_cast<decl_base*>(a))
    {
      if (qualified)
    result = d->get_qualified_name();
      else
    result = d->get_name();
    }
  else
    // We should never reach this point.
    abort();

  return result;
}

/// Build and return a copy of the name of an ABI artifact that is
/// either a type of a decl.
///
/// @param tod the ABI artifact to get the name for.
///
/// @param qualified if yes, return the qualified name of @p tod;
/// otherwise, return the non-qualified name;
///
/// @return the name of @p tod.
string
get_name(const type_or_decl_base_sptr& tod, bool qualified)
{return get_name(tod.get(), qualified);}

/// Build and return a qualified name from a name and its scope.
///
/// The name is supposed to be for an entity that is part of the
/// scope.
///
/// @param the scope to consider.
///
/// @param name of the name to consider.
///
/// @return a copy of the string that represents the qualified name.
string
build_qualified_name(const scope_decl* scope, const string& name)
{
  if (name.empty())
    return "";

  string qualified_name;
  if (scope)
    qualified_name = scope->get_qualified_name();

  if (qualified_name.empty())
    qualified_name = name;
  else
    qualified_name = qualified_name + "::" + name;

  return qualified_name;
}

/// Build and return the qualified name of a type in its scope.
///
/// @param scope the scope of the type to consider.
///
/// @param type the type to consider.
string
build_qualified_name(const scope_decl* scope, const type_base_sptr& type)
{return build_qualified_name(scope, get_name((type)));}

// </scope_decl stuff>

/// Get the location of the declaration of a given type.
///
/// @param type the type to consider.
///
/// @return the location of the declaration of type @p type.
location
get_location(const type_base_sptr& type)
{
  if (decl_base_sptr decl = get_type_declaration(type))
    return get_location(decl);
  return location();
}

/// Get the location of a given declaration.
///
/// @param decl the declaration to consider.
///
/// @return the location of the declaration @p decl.
location
get_location(const decl_base_sptr& decl)
{
  location loc = decl->get_location();
  if (!loc)
    {
      if (class_or_union_sptr c = is_class_or_union_type(decl))
    if (c->get_is_declaration_only() && c->get_definition_of_declaration())
      {
        c = is_class_or_union_type(c->get_definition_of_declaration());
        loc = c->get_location();
      }
    }
  return loc;
}

/// Get the scope of a given type.
///
/// @param t the type to consider.
///
/// @return the scope of type @p t or 0 if the type has no scope yet.
scope_decl*
get_type_scope(type_base* t)
{
  if (!t)
    return 0;

  decl_base* d = get_type_declaration(t);
  if (d)
    return d->get_scope();
  return 0;
}

/// Get the scope of a given type.
///
/// @param t the type to consider.
///
/// @return the scope of type @p t or 0 if the type has no scope yet.
scope_decl*
get_type_scope(const type_base_sptr& t)
{return get_type_scope(t.get());}

/// Get the name of a given type and return a copy of it.
///
/// @param t the type to consider.
///
/// @param qualified if true then return the qualified name of the
/// type.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return a copy of the type name if the type has a name, or the
/// empty string if it does not.
interned_string
get_type_name(const type_base_sptr& t, bool qualified, bool internal)
{return get_type_name(t.get(), qualified, internal);}

/// Return true iff a decl is for a type type that has a generic
/// anonymous internal type name.
///
/// @param d the decl to considier.
///
/// @return true iff @p d is for a type type that has a generic
/// anonymous internal type name.
static bool
has_generic_anonymous_internal_type_name(const decl_base *d)
{
  return (is_class_or_union_type(d)
      || is_enum_type(d)
      || is_subrange_type(d));
}

/// Return the generic internal name of an anonymous type.
///
/// For internal purposes, we want to define a generic name for all
/// anonymous types of a certain kind.  For instance, all anonymous
/// structs will be have a generic name of "__anonymous_struct__", all
/// anonymous unions will have a generic name of
/// "__anonymous_union__", etc.
///
/// That generic name can be used as a hash to put all anonymous types
/// of a certain kind in the same hash table bucket, for instance.
static interned_string
get_generic_anonymous_internal_type_name(const decl_base *d)
{
  ABG_ASSERT(has_generic_anonymous_internal_type_name(d));

  const environment&env = d->get_environment();

  interned_string result;
  if (is_class_type(d))
    result =
      env.intern(tools_utils::get_anonymous_struct_internal_name_prefix());
  else if (is_union_type(d))
    result =
      env.intern(tools_utils::get_anonymous_union_internal_name_prefix());
  else if (is_enum_type(d))
    result =
      env.intern(tools_utils::get_anonymous_enum_internal_name_prefix());
  else if (is_subrange_type(d))
    result =
      env.intern(tools_utils::get_anonymous_subrange_internal_name_prefix());
  else
    ABG_ASSERT_NOT_REACHED;

  return result;
}

/// Get the internal name for a given real type.
///
/// All real types that have the modifiers 'short, long or long
/// long' have the same internal name.  This is so that they can all
/// have the same canonical type if they are of the same size.
/// Otherwise, 'long int' and 'long long int' would have different
/// canonical types even though they are equivalent from an ABI point
/// of view.
///
/// @param t the real type to consider
///
/// @return the internal name for @p t if it's an integral type, or
/// the empty string if @p t is not a real type.
static string
get_internal_real_type_name(const type_base* t)
{
  string name;
  type_decl *type = is_real_type(t);

  if (!type)
    return name;

  real_type int_type;
  if (parse_real_type(type->get_name(), int_type))
    name = int_type.to_string(/*internal=*/true);

  return name;
}

/// Get the name of a given type and return a copy of it.
///
/// @param t the type to consider.
///
/// @param qualified if true then return the qualified name of the
/// type.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return a copy of the type name if the type has a name, or the
/// empty string if it does not.
interned_string
get_type_name(const type_base* t, bool qualified, bool internal)
{
  interned_string empty_string;

  if (!t)
    return empty_string;

  const decl_base* d = dynamic_cast<const decl_base*>(t);
  if (!d)
    {
      const function_type* fn_type = is_function_type(t);
      if (!fn_type)
    return empty_string;
      return fn_type->get_cached_name(internal);
    }

  const environment&env = d->get_environment();

  // All anonymous types of a given kind get to have the same internal
  // name for internal purpose.  This to allow them to be compared
  // among themselves during type canonicalization.
  if (internal)
    {
      if (d->get_is_anonymous() && !is_type_decl(t))
    {
      // Note that anonymous type_decl that are used for
      // enumerators are not handled here because they don't have
      // generic internal type names.
      string r;
      r += get_generic_anonymous_internal_type_name(d);
      return t->get_environment().intern(r);
    }

      if (is_typedef(t))
    return d->get_name();

      if (qualified)
    return d->get_qualified_name(internal);

      return env.intern(get_internal_real_type_name(t));
    }

  if (d->get_is_anonymous())
    {
      if (is_class_or_union_type(t) || is_enum_type(t))
    return env.intern
      (get_class_or_enum_flat_representation (*t, "",
                          /*one_line=*/true,
                          internal, qualified));
    }

  if (qualified)
    return d->get_qualified_name(internal);
  return d->get_name();
}

/// Get the name of a given type and return a copy of it.
///
/// @param t the type to consider.
///
/// @param qualified if true then return the qualified name of the
/// type.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return a copy of the type name if the type has a name, or the
/// empty string if it does not.
interned_string
get_type_name(const type_base& t, bool qualified, bool internal)
{return get_type_name(&t, qualified, internal);}

/// Get the name of the pointer to a given type.
///
/// @param pointed_to_type the pointed-to-type to consider.
///
/// @param qualified this is true if the resulting name should be of a
/// pointer to a *fully-qualified* pointed-to-type.
///
/// @param internal true if the name is for libabigail-internal
/// purposes.
///
/// @return the name (string representation) of the pointer.
interned_string
get_name_of_pointer_to_type(const type_base& pointed_to_type,
                bool qualified, bool internal)
{
  const environment& env = pointed_to_type.get_environment();
  string tn = get_type_name(pointed_to_type, qualified, internal);
  tn =  tn + "*";

  return env.intern(tn);
}

/// Get the name of the reference to a given type.
///
/// @param pointed_to_type the pointed-to-type to consider.
///
/// @param qualified this is true if the resulting name should be of a
/// reference to a *fully-qualified* pointed-to-type.
///
/// @param internal true if the name is for libabigail-internal
/// purposes.
///
/// @return the name (string representation) of the reference.
interned_string
get_name_of_reference_to_type(const type_base& pointed_to_type,
                  bool lvalue_reference,
                  bool qualified, bool internal)
{
  const environment& env = pointed_to_type.get_environment();

  string name = get_type_name(pointed_to_type, qualified, internal);
  if (lvalue_reference)
    name = name + "&";
  else
    name = name + "&&";

  return env.intern(name);
}

/// Get the name of a qualified type, given the underlying type and
/// its qualifiers.
///
/// @param underlying_type the underlying type to consider.
///
/// @param quals the CV qualifiers of the name.
///
/// @param qualified true if we should consider the fully qualified
/// name of @p underlying_type.
///
/// @param internal true if the result is to be used for
/// libabigail-internal purposes.
///
/// @return the name (string representation) of the qualified type.
interned_string
get_name_of_qualified_type(const type_base_sptr& underlying_type,
               qualified_type_def::CV quals,
               bool qualified, bool internal)
{
  const environment& env = underlying_type->get_environment();

  string quals_repr = get_string_representation_of_cv_quals(quals);
  string name = get_type_name(underlying_type, qualified, internal);

  if (quals_repr.empty() && internal)
    // We are asked to return the internal name, that might be used
    // for type canonicalization.  For that canonicalization, we need
    // to make a difference between a no-op qualified type which
    // underlying type is foo (the qualified type is named "none
    // foo"), and the name of foo, which is just "foo".
    //
    // Please remember that this has to be kept in sync with what is
    // done in die_qualified_name, in abg-dwarf-reader.cc.  So if you
    // change this code here, please change that code there too.
    quals_repr = "";

  if (!quals_repr.empty())
    {
      if (is_pointer_type(peel_qualified_type(underlying_type))
      || is_reference_type(peel_qualified_type(underlying_type)))
    {
      name += " ";
      name += quals_repr;
    }
      else
    name = quals_repr + " " + name;
    }

  return env.intern(name);
}

/// Get the name of a given function type and return a copy of it.
///
/// @param fn_type the function type to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return a copy of the function type name
interned_string
get_function_type_name(const function_type_sptr& fn_type,
               bool internal)
{return get_function_type_name(fn_type.get(), internal);}

/// Get the name of a given function type and return a copy of it.
///
/// @param fn_type the function type to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return a copy of the function type name
interned_string
get_function_type_name(const function_type* fn_type,
               bool internal)
{
  ABG_ASSERT(fn_type);

  if (const method_type* method = is_method_type(fn_type))
    return get_method_type_name(method, internal);

  return get_function_type_name(*fn_type, internal);
}

/// Get the name of a given function type and return a copy of it.
///
/// @param fn_type the function type to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return a copy of the function type name
interned_string
get_function_type_name(const function_type& fn_type,
               bool internal)
{
  std::ostringstream o;
  // When the function name is used for internal purposes (e.g, for
  // canonicalization), we want its representation to stay the same,
  // regardless of typedefs.  So let's strip typedefs from the return
  // type.
  type_base_sptr return_type = fn_type.get_return_type();
  const environment& env = fn_type.get_environment();

  o <<  get_type_name(return_type, /*qualified=*/true, internal) << " ";
  stream_pretty_representation_of_fn_parms(fn_type, o,
                       /*qualified=*/true,
                       internal);
  return env.intern(o.str());
}

/// Get the ID of a function, or, if the ID can designate several
/// different functions, get its pretty representation.
///
/// @param fn the function to consider
///
/// @return the function ID of pretty representation of @p fn.
interned_string
get_function_id_or_pretty_representation(const function_decl *fn)
{
  ABG_ASSERT(fn);

  interned_string result = fn->get_environment().intern(fn->get_id());

  if (const corpus *c = fn->get_corpus())
    {
      corpus::exported_decls_builder_sptr b =
    c->get_exported_decls_builder();
      if (b->fn_id_maps_to_several_fns(fn))
    result = fn->get_environment().intern(fn->get_pretty_representation());
    }

  return result;
}

/// Get the name of a given method type and return a copy of it.
///
/// @param fn_type the function type to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return a copy of the function type name
interned_string
get_method_type_name(const method_type_sptr fn_type,
             bool internal)
{return get_method_type_name(fn_type.get(), internal);}

/// Get the name of a given method type and return a copy of it.
///
/// @param fn_type the function type to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return a copy of the function type name
interned_string
get_method_type_name(const method_type* fn_type,
             bool internal)
{
  if (fn_type)
    return get_method_type_name(*fn_type, internal);

  return interned_string();
}

/// Get the name of a given method type and return a copy of it.
///
/// @param fn_type the function type to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return a copy of the function type name
interned_string
get_method_type_name(const method_type& fn_type,
             bool internal)
{
  std::ostringstream o;
  // When the function name is used for internal purposes (e.g, for
  // canonicalization), we want its representation to stay the same,
  // regardless of typedefs.  So let's strip typedefs from the return
  // type.
  type_base_sptr return_type = fn_type.get_return_type();

  const environment& env = fn_type.get_environment();

  if (return_type)
    o << get_type_name(return_type, /*qualified=*/true, internal);
  else
    // There are still some abixml files out there in which "void"
    // can be expressed as an empty type.
    o << "void";

  class_or_union_sptr class_type = fn_type.get_class_type();
  ABG_ASSERT(class_type);

  o << " (" << class_type->get_qualified_name(internal) << "::*) ";
  stream_pretty_representation_of_fn_parms(fn_type, o,
                       /*qualified=*/true,
                       internal);

  return env.intern(o.str());
}

/// Build and return a copy of the pretty representation of an ABI
/// artifact that could be either a type of a decl.
///
/// param tod the ABI artifact to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return a copy of the pretty representation of an ABI artifact
/// that could be either a type of a decl.
string
get_pretty_representation(const type_or_decl_base* tod, bool internal)
{
  string result;

  if (type_base* t = is_type(const_cast<type_or_decl_base*>(tod)))
    result = get_pretty_representation(t, internal);
  else if (decl_base* d = is_decl(const_cast<type_or_decl_base*>(tod)))
    result =  get_pretty_representation(d, internal);
  else
    // We should never reach this point
    abort();

  return result;
}

/// Build and return a copy of the pretty representation of an ABI
/// artifact that could be either a type of a decl.
///
/// param tod the ABI artifact to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return a copy of the pretty representation of an ABI artifact
/// that could be either a type of a decl.
string
get_pretty_representation(const type_or_decl_base_sptr& tod, bool internal)
{return get_pretty_representation(tod.get(), internal);}

/// Get a copy of the pretty representation of a decl.
///
/// @param d the decl to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the pretty representation of the decl.
string
get_pretty_representation(const decl_base* d, bool internal)
{
  if (!d)
    return "";
  return d->get_pretty_representation(internal);
}

/// Get a copy of the pretty representation of a type.
///
/// @param d the type to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the pretty representation of the type.
string
get_pretty_representation(const type_base* t, bool internal)
{
  if (!t)
    return "void";
  if (const function_type* fn_type = is_function_type(t))
    return get_pretty_representation(fn_type, internal);

  const decl_base* d = get_type_declaration(t);
  ABG_ASSERT(d);
  return get_pretty_representation(d, internal);
}

/// Get a copy of the pretty representation of a decl.
///
/// @param d the decl to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the pretty representation of the decl.
string
get_pretty_representation(const decl_base_sptr& d, bool internal)
{return get_pretty_representation(d.get(), internal);}

/// Get a copy of the pretty representation of a type.
///
/// @param d the type to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the pretty representation of the type.
string
get_pretty_representation(const type_base_sptr& t, bool internal)
{return get_pretty_representation(t.get(), internal);}

/// Get the pretty representation of a function type.
///
/// @param fn_type the function type to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the string represenation of the function type.
string
get_pretty_representation(const function_type_sptr& fn_type,
              bool internal)
{return get_pretty_representation(fn_type.get(), internal);}

/// Get the pretty representation of a function type.
///
/// @param fn_type the function type to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the string represenation of the function type.
string
get_pretty_representation(const function_type* fn_type, bool internal)
{
  if (!fn_type)
    return "void";

  if (const method_type* method = is_method_type(fn_type))
    return get_pretty_representation(method, internal);

  return get_pretty_representation(*fn_type, internal);
}

/// Get the pretty representation of a function type.
///
/// @param fn_type the function type to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the string represenation of the function type.
string
get_pretty_representation(const function_type& fn_type, bool internal)
{
  std::ostringstream o;
  o << "function type " << get_function_type_name(fn_type, internal);
  return o.str();
}

/// Get the pretty representation of a method type.
///
/// @param method the method type to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the string represenation of the method type.
string
get_pretty_representation(const method_type& method, bool internal)
{
  std::ostringstream o;
  o << "method type " << get_method_type_name(method, internal);
  return o.str();
}

/// Get the pretty representation of a method type.
///
/// @param method the method type to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the string represenation of the method type.
string
get_pretty_representation(const method_type* method, bool internal)
{
  if (!method)
    return "void";
  return get_pretty_representation(*method, internal);
}

/// Get the pretty representation of a method type.
///
/// @param method the method type to consider.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the string represenation of the method type.
string
get_pretty_representation(const method_type_sptr method, bool internal)
{return get_pretty_representation(method.get(), internal);}

/// Get the flat representation of an instance of @ref class_or_union
/// type.
///
/// The flat representation of a given @ref class_or_union type is the
/// actual definition of the type, for instance:
///
///   struct foo {int a; char b;}
///
///@param cou the instance of @ref class_or_union to consider.
///
///@param indent the identation spaces to use in the representation.
///
///@param one_line if true, then the flat representation stands on one
///line.  Otherwise, it stands on multiple lines.
///
///@return the resulting flat representation.
string
get_class_or_union_flat_representation(const class_or_union& cou,
                       const string& indent,
                       bool one_line,
                       bool internal,
                       bool qualified_names)
{
  string repr;
  string local_indent = "  ";

  if (class_decl* clazz = is_class_type(&cou))
    {
      repr = indent;
      if (!internal && clazz->is_struct())
    repr += "struct";
      else
    repr += "class";
    }
  else if (is_union_type(cou))
    repr = indent + "union";
  else
    return "";

  repr += " ";

  string name = cou.get_qualified_name();

  if (!cou.get_is_anonymous())
    repr += name;

  if (cou.priv_->is_printing_flat_representation())
    {
      // We have just detected a cycle while walking the sub-tree
      // of this class or union type for the purpose of printing
      // its flat representation.  We need to get out of here
      // pronto or else we'll be spinning endlessly.
      repr += "{}";
      return repr;
    }

  // Let's mark this class or union type to signify that we started
  // walking its sub-tree.  This is to detect potential cycles and
  // avoid looping endlessly.
  cou.priv_->set_printing_flat_representation();

  repr += "{";

  if (!one_line)
    repr += "\n";

  string real_indent;
  const class_or_union::data_members &dmems = cou.get_data_members();
  for (class_or_union::data_members::const_iterator dm = dmems.begin();
       dm != dmems.end();
       ++dm)
    {
      if (dm != dmems.begin())
    {
      if (one_line)
        real_indent = " ";
      else
        real_indent = "\n" + indent + local_indent;
    }

      if (var_decl_sptr v = is_anonymous_data_member(*dm))
    repr +=
      get_class_or_union_flat_representation
      (anonymous_data_member_to_class_or_union(*dm),
       real_indent, one_line, internal, qualified_names);
      else
    {
      if (one_line)
        {
          if (dm != dmems.begin())
        repr += real_indent;
          repr += (*dm)->get_pretty_representation(internal,
                               qualified_names);
        }
      else
        repr +=
          real_indent+ (*dm)->get_pretty_representation(internal,
                                qualified_names);
    }
      repr += ";";
    }

  if (one_line)
    repr += "}";
  else
    repr += indent + "}";

  // Let's unmark this class or union type to signify that we are done
  // walking its sub-tree.  This was to detect potential cycles and
  // avoid looping endlessly.
  cou.priv_->unset_printing_flat_representation();

  return repr;
}

/// Get the flat representation of an instance of @ref class_or_union
/// type.
///
/// The flat representation of a given @ref class_or_union type is the
/// actual definition of the type, for instance:
///
///   struct foo {int a; char b;}
///
///@param cou the instance of @ref class_or_union to consider.
///
///@param indent the identation spaces to use in the representation.
///
///@param one_line if true, then the flat representation stands on one
///line.  Otherwise, it stands on multiple lines.
///
///@return the resulting flat representation.
string
get_class_or_union_flat_representation(const class_or_union* cou,
                       const string& indent,
                       bool one_line,
                       bool internal,
                       bool qualified_names)
{
  if (cou)
    return get_class_or_union_flat_representation(*cou, indent, one_line,
                          internal, qualified_names);
  return "";
}

/// Get the flat representation of an instance of @ref class_or_union
/// type.
///
/// The flat representation of a given @ref class_or_union type is the
/// actual definition of the type, for instance:
///
///   struct foo {int a; char b;}
///
///@param cou the instance of @ref class_or_union to consider.
///
///@param indent the identation spaces to use in the representation.
///
///@param one_line if true, then the flat representation stands on one
///line.  Otherwise, it stands on multiple lines.
///
///@return the resulting flat representation.
string
get_class_or_union_flat_representation(const class_or_union_sptr& cou,
                       const string& indent,
                       bool one_line,
                       bool internal,
                       bool qualified_names)
{return get_class_or_union_flat_representation(cou.get(),
                           indent,
                           one_line,
                           internal,
                           qualified_names);}

/// Get the flat representation of an instance of @ref enum_type_decl
/// type.
///
/// The flat representation of a given @ref enum_type_decl type is the
/// actual definition of the type, for instance:
///
///   enum {E_0 =0, E_1 = 1}
///
///@param enum_type the enum type to consider.
///
///@param indent the identation spaces to use in the representation.
///
///@param one_line if true, then the flat representation stands on one
///line.  Otherwise, it stands on multiple lines.
///
///@param qualified_names use qualified names when applicable.
///Typically, if this is true, the name of the enum is going to be
///qualified.
///
///@return the resulting flat representation.
string
get_enum_flat_representation(const enum_type_decl& enum_type,
                 const string& indent, bool one_line,
                 bool qualified_names)
{
  string repr;
  std::ostringstream o;
  string local_indent = "  ";

  repr = indent + "enum ";

  if (!enum_type.get_is_anonymous())
    o << (qualified_names
      ? enum_type.get_qualified_name()
      : enum_type.get_name()) + " ";

  o << "{";

  if (!one_line)
    o << "\n";

  for (const auto &enumerator : enum_type.get_sorted_enumerators())
    {
      if (!one_line)
    o << "\n" + indent;

      o << enumerator.get_name() + "="  << enumerator.get_value() << ", ";
    }

  if (!one_line)
    o << "\n" + indent << "}";
  else
    o << "}";

  repr =o.str();

  return repr;
}

/// Get the flat representation of an instance of @ref enum_type_decl
/// type.
///
/// The flat representation of a given @ref enum_type_decl type is the
/// actual definition of the type, for instance:
///
///   enum {E_0 =0, E_1 = 1}
///
///@param enum_type the enum type to consider.
///
///@param indent the identation spaces to use in the representation.
///
///@param one_line if true, then the flat representation stands on one
///line.  Otherwise, it stands on multiple lines.
///
///@param qualified_names use qualified names when applicable.
///Typically, if this is true, the name of the enum is going to be
///qualified.
///
///@return the resulting flat representation.
string
get_enum_flat_representation(const enum_type_decl* enum_type,
                 const string& indent, bool one_line,
                 bool qualified_names)
{
  if (!enum_type)
    return "";

  return get_enum_flat_representation(*enum_type, indent,
                      one_line, qualified_names);
}

/// Get the flat representation of an instance of @ref enum_type_decl
/// type.
///
/// The flat representation of a given @ref enum_type_decl type is the
/// actual definition of the type, for instance:
///
///   enum {E_0 =0, E_1 = 1}
///
///@param enum_type the enum type to consider.
///
///@param indent the identation spaces to use in the representation.
///
///@param one_line if true, then the flat representation stands on one
///line.  Otherwise, it stands on multiple lines.
///
///@param qualified_names use qualified names when applicable.
///Typically, if this is true, the name of the enum is going to be
///qualified.
///
///@return the resulting flat representation.
string
get_enum_flat_representation(const enum_type_decl_sptr& enum_type,
                 const string& indent, bool one_line,
                 bool qualified_names)
{
  return get_enum_flat_representation(enum_type.get(),
                      indent, one_line,
                      qualified_names);
}

/// Get the flat representation of an instance of @ref enum_type_decl
/// type.
///
/// The flat representation of a given @ref enum_type_decl type is the
/// actual definition of the type, for instance:
///
///   enum {E_0 =0, E_1 = 1}
///
///@param enum_type the enum type to consider.
///
///@param indent the identation spaces to use in the representation.
///
///@param one_line if true, then the flat representation stands on one
///line.  Otherwise, it stands on multiple lines.
///
///@param qualified_names use qualified names when applicable.
///Typically, if this is true, the name of the enum is going to be
///qualified.
///
///@return the resulting flat representation.
string
get_class_or_enum_flat_representation(const type_base& coe,
                      const string& indent,
                      bool one_line,
                      bool internal,
                      bool qualified_name)

{
  string repr;
  if (const class_or_union* cou = is_class_or_union_type(&coe))
    repr = get_class_or_union_flat_representation(cou, indent, one_line,
                          internal, qualified_name);
  else if (const enum_type_decl* enom = is_enum_type(&coe))
    repr = get_enum_flat_representation(*enom, indent, one_line, qualified_name);

  return repr;
}

/// Get the textual representation of a type for debugging purposes.
///
/// If the type is a class/union, this shows the data members, virtual
/// member functions, size, pointer value of its canonical type, etc.
/// Otherwise, this just shows the name of the artifact as returned by
/// type_or_decl_base:get_pretty_representation().
///
/// @param artifact the artifact to show a debugging representation of.
///
/// @return a debugging string representation of @p artifact.
string
get_debug_representation(const type_or_decl_base* artifact)
{
  string nil_str;
  if (!artifact)
    return nil_str;

  class_or_union * c = is_class_or_union_type(artifact);
  if (c)
    {
      class_decl *clazz = is_class_type(c);
      string name = c->get_qualified_name();
      std::ostringstream o;
      if (clazz)
    {
      if (clazz->is_struct())
        o << "struct ";
      else
        o << "class ";
    }
      else if (is_union_type(c))
    o << "union ";
      o << name;

      if (clazz)
    {
      if (!clazz->get_base_specifiers().empty())
        o << " :" << std::endl;
      for (auto &b : clazz->get_base_specifiers())
        {
          o << "  ";
          if (b->get_is_virtual())
        o << "virtual ";
          o << b->get_base_class()->get_qualified_name()
        << "   // hash: ";
          hash_t h = peek_hash_value(*b->get_base_class());
          if (h)
        o << std::hex << *h << std::dec;
          else
        o << "none";
          o << std::endl;
        }
    }
      o << std::endl
    << "{"
    << "   // size in bits: " << c->get_size_in_bits() << "\n"
    << "   // is-declaration-only: " << c->get_is_declaration_only() << "\n"
    << "   // definition point: " << get_natural_or_artificial_location(c).expand() << "\n"
    << "   // translation unit: "
    << (c->get_translation_unit()
        ? c->get_translation_unit()->get_absolute_path()
        : nil_str)
    << std::endl
    << "   // @: " << std::hex << is_type(c)
    << ", @canonical: " << c->get_canonical_type().get() << std::dec << "\n"
    << "   // hash: " ;

      hash_t h = peek_hash_value(*c);
      if (h)
    o << std::hex << *h << std::dec;
      else
    o << "none";
      o << "\n" <<  "   // cti: " << std::dec << get_canonical_type_index(*c);
      o << "\n\n";


      for (auto member_type : c->get_sorted_member_types())
    {
      o << "  "
        << member_type->get_pretty_representation(/*internal=*/false,
                              /*qualified=*/false)
        << ";";
      if (member_type->get_canonical_type())
        {
          o << " // uses canonical type: '@"
        << std::hex << member_type->get_canonical_type().get() << "'";
          o << " / h:";
          hash_t h = peek_hash_value(*member_type);
          o << std::hex << *h << std::dec;
          if (get_canonical_type_index(*member_type))
        o << "#" << get_canonical_type_index(*member_type);
        }
      o << "\n";
    }

      if (!c->get_sorted_member_types().empty())
    o << std::endl;

      for (auto m : c->get_data_members())
    {
      type_base_sptr t = m->get_type();
      t = peel_typedef_pointer_or_reference_type(t);

      o << "  "
        << m->get_pretty_representation(/*internal=*/false,
                        /*qualified=*/false)
        << ";";

      if (t && t->get_canonical_type())
        o << " // uses canonical type '@"
          << std::hex << t->get_canonical_type().get() << "'";

      o << "/ h:";
      hash_t h = peek_hash_value(*m->get_type());
      if (h)
        o << std::hex << *h << std::dec;
      else
        o << "none";
      o << std::endl;
    }

      if (!c->get_data_members().empty())
    o << std::endl;

      if (clazz && clazz->has_vtable())
    {
      o << "  // virtual member functions\n\n";
      for (auto f : clazz->get_virtual_mem_fns())
        {
          o << "  " << f->get_pretty_representation(/*internal=*/false,
                            /*qualified=*/false)
        << "   // voffset: " << get_member_function_vtable_offset(f)
        << ", h: ";
          hash_t h = peek_hash_value(*f->get_type());
          if (h)
        o << std::hex << *h << std::dec;
          else
        o << "none";
          o << ";" << std::endl;
        }
    }

      o << "};" << std::endl;

      return o.str();
    }
  else if (const enum_type_decl* e = is_enum_type(artifact))
    {
      string name = e->get_qualified_name();
      std::ostringstream o;
      o << "enum " << name
    << " : "
    << e->get_underlying_type()->get_pretty_representation(/*internal=*/false,
                                   true)
    << "\n"
    << "{\n"
    << "  // size in bits: " << e->get_size_in_bits() << "\n"
    << "  // is-declaration-only: " << e->get_is_declaration_only() << "\n"
    << " // definition point: " << get_natural_or_artificial_location(e).expand() << "\n"
    << "  // translation unit: "
    << e->get_translation_unit()->get_absolute_path() << "\n"
    << "  // @: " << std::hex << is_type(e)
    << ", @canonical: " << e->get_canonical_type().get() << std::dec << "\n"
    << "  // hash: ";

      hash_t h = peek_hash_value(*e);
      if (h)
    o << std::hex << *h << std::dec;
      else
    o << "none";
      o << "\n" << "  // cti: " << std::dec << get_canonical_type_index(*e);
      o << "\n\n";

      for (const auto &enom : e->get_enumerators())
    o << "  " << enom.get_name() << " = " << enom.get_value() << ",\n";

      o << "};\n";

      return o.str();
    }
  else if (type_base *t = is_type(artifact))
    {
      std::ostringstream o;
      o << t->get_pretty_representation(/*internal=*/true,
                    /*qualified=*/true)
    << " // cti: " << get_canonical_type_index(*t)
    << "\n";
      return o.str();
    }

  return artifact->get_pretty_representation(/*internal=*/true,
                         /*qualified=*/true);
}

/// Get a given data member, referred to by its name, of a class type.
///
/// @param clazz the class to consider.
///
/// @param member_name name of the data member to get.
///
/// @return the resulting data member or nullptr if none was found.
var_decl_sptr
get_data_member(class_or_union *clazz, const char* member_name)
{
  if (!clazz)
    return var_decl_sptr();
  return clazz->find_data_member(member_name);
}

/// Get a given data member, referred to by its name, of a class type.
///
/// @param clazz the class to consider.
///
/// @param member_name name of the data member to get.
///
/// @return the resulting data member or nullptr if none was found.
var_decl_sptr
get_data_member(type_base *clazz, const char* member_name)
{return get_data_member(is_class_or_union_type(clazz), member_name);}

/// Get the non-artificial (natural) location of a decl.
///
/// If the decl doesn't have a natural location then return its
/// artificial one.
///
/// @param decl the decl to consider.
///
/// @return the natural location @p decl if it has one; otherwise,
/// return its artificial one.
const location&
get_natural_or_artificial_location(const decl_base* decl)
{
  ABG_ASSERT(decl);

  if (decl->get_location())
    return decl->get_location();
  return decl->get_artificial_location();
}

/// Get the artificial location of a decl.
///
/// If the decl doesn't have an artificial location then return its
/// natural one.
///
/// @param decl the decl to consider.
///
/// @return the artificial location @p decl if it has one; otherwise,
/// return its natural one.
const location&
get_artificial_or_natural_location(const decl_base* decl)
{
  ABG_ASSERT(decl);

  if (decl->has_artificial_location())
    return decl->get_artificial_location();
  return decl->get_location();
}

/// Emit a textual representation of an artifact to std error stream
/// for debugging purposes.
///
/// This is useful to invoke from within a command line debugger like
/// GDB to help make sense of a given ABI artifact.
///
/// @param artifact the ABI artifact to emit the debugging
/// representation for.
///
/// @return the artifact @p artifact.
type_or_decl_base*
debug(const type_or_decl_base* artifact)
{
  std::cerr << get_debug_representation(artifact) << std::endl;
  return const_cast<type_or_decl_base*>(artifact);
}

/// Emit a textual representation of an artifact to std error stream
/// for debugging purposes.
///
/// This is useful to invoke from within a command line debugger like
/// GDB to help make sense of a given ABI artifact.
///
/// @param artifact the ABI artifact to emit the debugging
/// representation for.
///
/// @return the artifact @p artifact.
type_base*
debug(const type_base* artifact)
{
  debug(static_cast<const type_or_decl_base*>(artifact));
  return const_cast<type_base*>(artifact);
}

/// Emit a textual representation of an artifact to std error stream
/// for debugging purposes.
///
/// This is useful to invoke from within a command line debugger like
/// GDB to help make sense of a given ABI artifact.
///
/// @param artifact the ABI artifact to emit the debugging
/// representation for.
///
/// @return the artifact @p artifact.
decl_base*
debug(const decl_base* artifact)
{
  debug(static_cast<const type_or_decl_base*>(artifact));
  return const_cast<decl_base*>(artifact);
}

/// Test if two ABI artifacts are equal.
///
/// This can be useful when used from the command line of a debugger
/// like GDB.
///
/// @param l the first ABI artifact to consider in the comparison.
///
/// @param r the second ABI artifact to consider in the comparison.
///
/// @return true iff @p l equals @p r.
bool
debug_equals(const type_or_decl_base *l, const type_or_decl_base *r)
{
  if (!!l != !!r)
    return false;
  if (!l && !r)
    return true;

  return (*l == *r);
}

/// Emit a trace of a comparison operand stack.
///
/// @param vect the operand stack to emit the trace for.
///
/// @param o the output stream to emit the trace to.
static void
debug_comp_vec(const vector<const type_base*>& vect, std::ostringstream& o)
{
  for (auto t : vect)
    {
      o << "|" << t->get_pretty_representation()
    << "@" << std::hex << t << std::dec;
    }
  if (!vect.empty())
    o << "|";
}

/// Construct a trace of the two comparison operand stacks.
///
/// @param the environment in which the comparison operand stacks are.
///
/// @return a string representing the trace.
static string
print_comp_stack(const environment& env)
{
  std::ostringstream o;
  o << "left-operands: ";
  debug_comp_vec(env.priv_->left_type_comp_operands_, o);
  o << "\n" << "right-operands: ";
  debug_comp_vec(env.priv_->right_type_comp_operands_, o);
  o << "\n";
  return o.str();
}

/// Emit a trace of the two comparison operands stack on the standard
/// error stream.
///
/// @param env the environment the comparison operands stack belong
/// to.
void
debug_comp_stack(const environment& env)
{
  std::cerr << print_comp_stack(env);
  std::cerr << std::endl;
}

/// By looking at the language of the TU a given ABI artifact belongs
/// to, test if the ONE Definition Rule should apply.
///
/// To date, it applies to c++, java and ada.
///
/// @param artifact the ABI artifact to consider.
///
/// @return true iff the One Definition Rule should apply.
bool
odr_is_relevant(const type_or_decl_base& artifact)
{
  if (!artifact.get_translation_unit())
    return false;

  translation_unit::language l =
    artifact.get_translation_unit()->get_language();

  if (is_cplus_plus_language(l)
      || is_java_language(l)
      || is_ada_language(l))
    return true;

  return false;
}

/// Get the declaration for a given type.
///
/// @param t the type to consider.
///
/// @return the declaration for the type to return.
const decl_base*
get_type_declaration(const type_base* t)
{return dynamic_cast<const decl_base*>(t);}

/// Get the declaration for a given type.
///
/// @param t the type to consider.
///
/// @return the declaration for the type to return.
decl_base*
get_type_declaration(type_base* t)
{return dynamic_cast<decl_base*>(t);}

/// Get the declaration for a given type.
///
/// @param t the type to consider.
///
/// @return the declaration for the type to return.
decl_base_sptr
get_type_declaration(const type_base_sptr t)
{return dynamic_pointer_cast<decl_base>(t);}

/// Test if two classes have the same layout.
///
/// Test if all the types and offsets of the members are equal,
/// regardless of their access modifiers.
///
/// @param f the first class to take into account.
///
/// @param s the second class to take into account.
///
/// @return true iff @p s and @p f are class types with the same
/// layout.
bool
classes_have_same_layout(const type_base_sptr& f, const type_base_sptr& s)
{
#ifdef RETURN_FROM_CLASSES_HAVE_SAME_LAYOUT
#undef RETURN_FROM_CLASSES_HAVE_SAME_LAYOUT
#endif

#ifdef ENSURE_NO_ENDLESS_LOOP
#undef ENSURE_NO_ENDLESS_LOOP
#endif

#define RETURN_FROM_CLASSES_HAVE_SAME_LAYOUT(VALUE)     \
  do                                \
    {                               \
      auto t1 = is_class_or_union_type(f);          \
      auto t2 = is_class_or_union_type(s);          \
      t1->priv_->comparing_class_layouts_.erase(t2.get());  \
      t2->priv_->comparing_class_layouts_.erase(t1.get());  \
      return VALUE;                     \
    } while (false)

#define ENSURE_NO_ENDLESS_LOOP                      \
  do                                    \
    {                                   \
      auto t1 = is_class_or_union_type(f);              \
      auto t2 = is_class_or_union_type(s);              \
      const auto& END = t1->priv_->comparing_class_layouts_.end();  \
      if (t1->priv_->comparing_class_layouts_.find(t2.get()) != END \
      || t2->priv_->comparing_class_layouts_.find(t1.get()) != END) \
    return true;                            \
      t1->priv_->comparing_class_layouts_.insert(t2.get());     \
      t2->priv_->comparing_class_layouts_.insert(t1.get());     \
    } while (false)

  class_decl_sptr fc = is_class_type(peel_qualified_or_typedef_type(f)),
    sc = is_class_type(peel_qualified_or_typedef_type(s));

  if (!fc
      || !sc
      || (fc->get_qualified_name() != sc->get_qualified_name())
      || (fc->get_size_in_bits() != sc->get_size_in_bits())
      || (fc->get_data_members().size() != sc->get_data_members().size()))
    return false;

  if (*fc == *sc)
    RETURN_FROM_CLASSES_HAVE_SAME_LAYOUT(true);

  // Compare the types and offsets of data members one by one.
  for (auto f_decl_it = fc->get_data_members().begin(),
     s_decl_it = sc->get_data_members().begin();
       (f_decl_it != fc->get_data_members().end()
    && s_decl_it != sc->get_data_members().end());
       ++f_decl_it, ++s_decl_it)
    {
      var_decl_sptr dm1 = *f_decl_it, dm2 = *s_decl_it;
      type_base_sptr dm1_type = dm1->get_type(), dm2_type = dm2->get_type();

      if (*dm1_type != *dm2_type
      || get_data_member_offset(dm1) != get_data_member_offset(dm2))
    RETURN_FROM_CLASSES_HAVE_SAME_LAYOUT(false);
    }

  // Compare the layout of base types
  for (auto f_bs_it = fc->get_base_specifiers().begin(),
     s_bs_it = sc->get_base_specifiers().end();
       (f_bs_it != fc->get_base_specifiers().end()
    && s_bs_it != sc->get_base_specifiers().end());
       ++f_bs_it, ++s_bs_it)
    {
      class_decl::base_spec_sptr f_bs = *f_bs_it, s_bs = *s_bs_it;
      if ((f_bs->get_is_virtual() != s_bs->get_is_virtual())
      || (f_bs->get_offset_in_bits() != s_bs->get_offset_in_bits()))
    RETURN_FROM_CLASSES_HAVE_SAME_LAYOUT(false);

      class_decl_sptr fb = f_bs->get_base_class(), sb = s_bs->get_base_class();
      if (!classes_have_same_layout(fb, sb))
    RETURN_FROM_CLASSES_HAVE_SAME_LAYOUT(false);
    }

  if (fc->has_vtable() != sc->has_vtable())
    RETURN_FROM_CLASSES_HAVE_SAME_LAYOUT(false);

  // Compare virtual function types
  ENSURE_NO_ENDLESS_LOOP;
  if (fc->has_vtable())
    {
      if (fc->get_virtual_mem_fns().size() > sc->get_virtual_mem_fns().size())
    // Some virtual member function got removed.  Bad.
    RETURN_FROM_CLASSES_HAVE_SAME_LAYOUT(false);

      for (auto it1 = fc->get_virtual_mem_fns().begin(),
         it2 = sc->get_virtual_mem_fns().begin();
       (it1 != fc->get_virtual_mem_fns().end()
        && it2 != sc->get_virtual_mem_fns().end());
       ++it1, ++it2)
    {
      method_decl_sptr method1 = *it1;
      method_decl_sptr method2 = *it2;

      if ((get_member_function_vtable_offset(method1)
           != get_member_function_vtable_offset(method2))
          || !types_are_compatible(method1->get_type(),
                       method2->get_type()))
        RETURN_FROM_CLASSES_HAVE_SAME_LAYOUT(false);
    }
    }

  RETURN_FROM_CLASSES_HAVE_SAME_LAYOUT(true);

#ifdef RETURN_FROM_CLASSES_HAVE_SAME_LAYOUT
#undef RETURN_FROM_CLASSES_HAVE_SAME_LAYOUT
#endif

#ifdef ENSURE_NO_ENDLESS_LOOP
#undef ENSURE_NO_ENDLESS_LOOP
#endif
}

/// Test if two types are equal modulo a typedef or CV qualifiers.
///
/// Type A and B are compatible if
///
/// - A and B are equal
/// - or A and B are integral types with harmless name change
/// - or if one type is a typedef of the other one.
/// - or if one type is the CV qualified version of the other
/// - or if A and B are classes with the same layout.
/// - or if A and B are pointers, references or arrays of
///   compatible types
///
/// @param type1 the first type to consider.
///
/// @param type2 the second type to consider.
///
/// @return true iff @p type1 and @p type2 are compatible.
bool
types_are_compatible(const type_base_sptr type1, const type_base_sptr type2)
{
  if (!type1 || !type2)
    return false;

  if (type1 == type2 || *type1 == *type2)
    return true;

  type_base_sptr t1 = peel_qualified_or_typedef_type(type1);
  type_base_sptr t2 = peel_qualified_or_typedef_type(type2);

  if (t1 && t2 && *t1 == *t2)
    return true;

  if (integral_type_has_harmless_name_change(t1, t2))
    return true;

  if (is_pointer_type(t1) && is_pointer_type(t2))
    {
      t1 = is_pointer_type(t1)->get_pointed_to_type();
      t2 = is_pointer_type(t2)->get_pointed_to_type();
      return types_are_compatible(t1, t2);
    }

  if (is_reference_type(t1) && is_reference_type(t2))
    {
      t1 = is_reference_type(t1)->get_pointed_to_type();
      t2 = is_reference_type(t2)->get_pointed_to_type();
      return types_are_compatible(t1, t2);
    }

  if (is_array_type(t1) && is_array_type(t2))
    {
      array_type_def_sptr a1 = is_array_type(t1);
      array_type_def_sptr a2 =is_array_type(t2);
      type_base_sptr e1 = a1->get_element_type();
      type_base_sptr e2 = a2->get_element_type();
      e1 = peel_qualified_or_typedef_type(e1);
      e2 = peel_qualified_or_typedef_type(e2);

      if ((a1->get_size_in_bits() != a2->get_size_in_bits())
      || (a1->get_dimension_count() != a2->get_dimension_count())
      || !types_are_compatible(e1, e2))
    return false;

      return true;
    }

  if (function_type_sptr fn_type1 = is_function_type(t1))
    if (function_type_sptr fn_type2 = is_function_type(t2))
      {
    // Compare return types
    if (!types_are_compatible(fn_type1->get_return_type(),
                  fn_type2->get_return_type()))
      return false;

    // Compare parameter types, omitting the implicit parameter to
    // avoid infinite recursion when we are being called from
    // classes_have_same_layout on classes with virtual member
    // functions.
    if (fn_type1->get_parameters().size()
        != fn_type2->get_parameters().size())
      return false;

    for (auto p1 = fn_type1->get_first_non_implicit_parm(),
         p2 = fn_type2->get_first_non_implicit_parm();
         (p1 != fn_type1->get_parameters().end()
          && p2 != fn_type2->get_parameters().end());
         ++p1, ++p2)
      if (!types_are_compatible((*p1)->get_type(),
                    (*p2)->get_type()))
        return false;

    return true;
      }

  if (classes_have_same_layout(t1, t2))
    return true;

  return false;
}

/// Test if two types are equal modulo a typedef.
///
/// Type A and B are compatible if
///
/// - A and B are equal
/// - or if one type is a typedef of the other one.
///
/// @param type1 the declaration of the first type to consider.
///
/// @param type2 the declaration of the second type to consider.
///
/// @return true iff @p type1 and @p type2 are compatible.
bool
types_are_compatible(const decl_base_sptr d1,
             const decl_base_sptr d2)
{return types_are_compatible(is_type(d1), is_type(d2));}

/// Return the translation unit a declaration belongs to.
///
/// @param decl the declaration to consider.
///
/// @return the resulting translation unit, or null if the decl is not
/// yet added to a translation unit.
translation_unit*
get_translation_unit(const type_or_decl_base& t)
{
  translation_unit* result =
    const_cast<translation_unit*>(t.get_translation_unit());

  if (result)
    return result;

  if (decl_base* decl = is_decl(&t))
    {
      scope_decl* scope = decl->get_scope();
      while (scope)
    {
      result = scope->get_translation_unit();
      if (result)
        break;
      scope = scope->get_scope();
    }
    }

  return result;
}

/// Return the translation unit a declaration belongs to.
///
/// @param decl the declaration to consider.
///
/// @return the resulting translation unit, or null if the decl is not
/// yet added to a translation unit.
translation_unit*
get_translation_unit(const type_or_decl_base* decl)
{return decl ? get_translation_unit(*decl) : nullptr;}

/// Return the translation unit a declaration belongs to.
///
/// @param decl the declaration to consider.
///
/// @return the resulting translation unit, or null if the decl is not
/// yet added to a translation unit.
translation_unit*
get_translation_unit(const type_or_decl_base_sptr& decl)
{return get_translation_unit(decl.get());}

/// Tests whether if a given scope is the global scope.
///
/// @param scope the scope to consider.
///
/// @return true iff the current scope is the global one.
bool
is_global_scope(const scope_decl& scope)
{return !!dynamic_cast<const global_scope*>(&scope);}

/// Tests whether if a given scope is the global scope.
///
/// @param scope the scope to consider.
///
/// @return the @ref global_scope* representing the scope @p scope or
/// 0 if @p scope is not a global scope.
const global_scope*
is_global_scope(const scope_decl* scope)
{return dynamic_cast<const global_scope*>(scope);}

/// Tests whether if a given scope is the global scope.
///
/// @param scope the scope to consider.
///
/// @return true iff the current scope is the global one.
bool
is_global_scope(const shared_ptr<scope_decl>scope)
{return is_global_scope(scope.get());}

/// Tests whether a given declaration is at global scope.
///
/// @param decl the decl to consider.
///
/// @return true iff decl is at global scope.
bool
is_at_global_scope(const decl_base& decl)
{return (is_global_scope(decl.get_scope()));}

/// Tests whether a given declaration is at global scope.
///
/// @param decl the decl to consider.
///
/// @return true iff decl is at global scope.
bool
is_at_global_scope(const decl_base_sptr decl)
{return (decl && is_global_scope(decl->get_scope()));}

/// Tests whether a given declaration is at global scope.
///
/// @param decl the decl to consider.
///
/// @return true iff decl is at global scope.
bool
is_at_global_scope(const decl_base* decl)
{return is_at_global_scope(*decl);}

/// Tests whether a given decl is at class scope.
///
/// @param decl the decl to consider.
///
/// @return true iff decl is at class scope.
class_or_union*
is_at_class_scope(const decl_base_sptr decl)
{return is_at_class_scope(decl.get());}

/// Tests whether a given decl is at class scope.
///
/// @param decl the decl to consider.
///
/// @return true iff decl is at class scope.
class_or_union*
is_at_class_scope(const decl_base* decl)
{
  if (!decl)
    return 0;

  return is_at_class_scope(*decl);
}

/// Tests whether a given decl is at class scope.
///
/// @param decl the decl to consider.
///
/// @return true iff decl is at class scope.
class_or_union*
is_at_class_scope(const decl_base& decl)
{
  scope_decl* scope = decl.get_scope();
  if (class_or_union* cl = is_class_type(scope))
    return cl;
  if (class_or_union* cl = is_union_type(scope))
    return cl;
  return 0;
}

/// Find a data member inside an anonymous data member.
///
/// An anonymous data member has a type which is a class or union.
/// This function looks for a data member inside the type of that
/// anonymous data member.
///
/// @param anon_dm the anonymous data member to consider.
///
/// @param name the name of the data member to look for.
var_decl_sptr
find_data_member_from_anonymous_data_member(const var_decl_sptr& anon_dm,
                        const string& name)
{
  const class_or_union* containing_class_or_union =
    anonymous_data_member_to_class_or_union(anon_dm.get());

  if (!containing_class_or_union)
    return var_decl_sptr();

  var_decl_sptr result = containing_class_or_union->find_data_member(name);
  return result;
}

/// Tests whether a given decl is at template scope.
///
/// Note that only template parameters , types that are compositions,
/// and template patterns (function or class) can be at template scope.
///
/// @param decl the decl to consider.
///
/// @return true iff the decl is at template scope.
bool
is_at_template_scope(const shared_ptr<decl_base> decl)
{return (decl && dynamic_cast<template_decl*>(decl->get_scope()));}

/// Tests whether a decl is a template parameter.
///
/// @param decl the decl to consider.
///
/// @return true iff decl is a template parameter.
bool
is_template_parameter(const shared_ptr<decl_base> decl)
{
  return (decl && (dynamic_pointer_cast<type_tparameter>(decl)
           || dynamic_pointer_cast<non_type_tparameter>(decl)
           || dynamic_pointer_cast<template_tparameter>(decl)));
}

/// Test whether a declaration is a @ref function_decl.
///
/// @param d the declaration to test for.
///
/// @return a shared pointer to @ref function_decl if @p d is a @ref
/// function_decl.  Otherwise, a nil shared pointer.
function_decl*
is_function_decl(const type_or_decl_base* d)
{return dynamic_cast<function_decl*>(const_cast<type_or_decl_base*>(d));}

/// Test whether a declaration is a @ref function_decl.
///
/// @param d the declaration to test for.
///
/// @return true if @p d is a function_decl.
bool
is_function_decl(const type_or_decl_base& d)
{return is_function_decl(&d);}

/// Test whether a declaration is a @ref function_decl.
///
/// @param d the declaration to test for.
///
/// @return a shared pointer to @ref function_decl if @p d is a @ref
/// function_decl.  Otherwise, a nil shared pointer.
function_decl_sptr
is_function_decl(const type_or_decl_base_sptr& d)
{return dynamic_pointer_cast<function_decl>(d);}

/// Test whether a declaration is a @ref function_decl.
///
/// @param d the declaration to test for.
///
/// @return a pointer to @ref function_decl if @p d is a @ref
/// function_decl.  Otherwise, a nil shared pointer.
function_decl::parameter*
is_function_parameter(const type_or_decl_base* tod)
{
  return dynamic_cast<function_decl::parameter*>
    (const_cast<type_or_decl_base*>(tod));
}

/// Test whether an ABI artifact is a @ref function_decl.
///
/// @param tod the declaration to test for.
///
/// @return a pointer to @ref function_decl if @p d is a @ref
/// function_decl.  Otherwise, a nil shared pointer.
function_decl::parameter_sptr
is_function_parameter(const type_or_decl_base_sptr tod)
{return dynamic_pointer_cast<function_decl::parameter>(tod);}

/// Test if an ABI artifact is a declaration.
///
/// @param d the artifact to consider.
///
/// @param return the declaration sub-object of @p d if it's a
/// declaration, or NULL if it is not.
decl_base*
is_decl(const type_or_decl_base* d)
{
  if (d && (d->kind() & type_or_decl_base::ABSTRACT_DECL_BASE))
    {
      if (!(d->kind() & type_or_decl_base::ABSTRACT_TYPE_BASE))
    // The artifact is a decl-only (like a function or a
    // variable).  That is, it's not a type that also has a
    // declaration.  In this case, we are in the fast path and we
    // have a pointer to the decl sub-object handy.  Just return
    // it ...
    return reinterpret_cast<decl_base*>
      (const_cast<type_or_decl_base*>(d)->type_or_decl_base_pointer());

      // ... Otherwise, we are in the slow path, which is that the
      // artifact is a type which has a declaration.  In that case,
      // let's use the slow dynamic_cast because we don't have the
      // pointer to the decl sub-object handily present.
      return dynamic_cast<decl_base*>(const_cast<type_or_decl_base*>(d));
    }
  return 0;
}

/// Test if an ABI artifact is a declaration.
///
/// @param d the artifact to consider.
///
/// @param return the declaration sub-object of @p d if it's a
/// declaration, or NULL if it is not.
decl_base_sptr
is_decl(const type_or_decl_base_sptr& d)
{return dynamic_pointer_cast<decl_base>(d);}

/// Test if an ABI artifact is a declaration.
///
/// This is done using a slow path that uses dynamic_cast.
///
/// @param d the artifact to consider.
///
/// @param return the declaration sub-object of @p d if it's a
decl_base*
is_decl_slow(const type_or_decl_base* t)
{return dynamic_cast<decl_base*>(const_cast<type_or_decl_base*>(t));}

/// Test if an ABI artifact is a declaration.
///
/// This is done using a slow path that uses dynamic_cast.
///
/// @param d the artifact to consider.
///
/// @param return the declaration sub-object of @p d if it's a
decl_base_sptr
is_decl_slow(const type_or_decl_base_sptr& t)
{return dynamic_pointer_cast<decl_base>(t);}

/// Test whether a declaration is a type.
///
/// @param d the IR artefact to test for.
///
/// @return true if the artifact is a type, false otherwise.
bool
is_type(const type_or_decl_base& tod)
{
  if (dynamic_cast<const type_base*>(&tod))
    return true;
  return false;
}

/// Test whether a declaration is a type.
///
/// @param d the IR artefact to test for.
///
/// @return true if the artifact is a type, false otherwise.
type_base*
is_type(const type_or_decl_base* t)
{
  if (t && (t->kind() & type_or_decl_base::ABSTRACT_TYPE_BASE))
    return reinterpret_cast<type_base*>
      (const_cast<type_or_decl_base*>(t)->type_or_decl_base_pointer());

  return 0;
}

/// Test whether a declaration is a type.
///
/// @param d the IR artefact to test for.
///
/// @return true if the artifact is a type, false otherwise.
type_base_sptr
is_type(const type_or_decl_base_sptr& tod)
{return dynamic_pointer_cast<type_base>(tod);}

/// Test whether a declaration is a type.
///
/// @param d the declaration to test for.
///
/// @return true if the declaration is a type, false otherwise.

/// Test if a given type is anonymous.
///
/// Note that this function considers that an anonymous class that is
/// named by a typedef is not anonymous anymore.  This is the C idiom:
///
///       typedef struct {int member;} s_type;
///
/// The typedef s_type becomes the name of the originally anonymous
/// struct.
///
/// @param t the type to consider.
///
/// @return true iff @p t is anonymous.
bool
is_anonymous_type(const type_base* t)
{
  const decl_base* d = get_type_declaration(t);
  if (d)
    if (d->get_is_anonymous())
      {
    if (class_or_union *cou = is_class_or_union_type(t))
      {
        // An anonymous class that is named by a typedef is not
        // considered anonymous anymore.
        if (!cou->get_naming_typedef())
          return true;
      }
    else
      return true;
      }
  return false;
}

/// Test if a given type is anonymous.
///
/// @param t the type to consider.
///
/// @return true iff @p t is anonymous.
bool
is_anonymous_type(const type_base_sptr& t)
{return is_anonymous_type(t.get());}

/// Test if a type is a neither a pointer, an array nor a function
/// type.
///
/// @param t the type to consider.
///
/// @return true if the @p t is NOT a pointer, an array nor a
/// function.
bool
is_npaf_type(const type_base_sptr& t)
{
  if (!(is_pointer_type(t)
    || is_array_type(t)
    || is_function_type(t)
    || is_ptr_to_mbr_type(t)))
    return true;
  return false;
}

/// Test whether a type is a type_decl (a builtin type).
///
/// @return the type_decl* for @t if it's type_decl, otherwise, return
/// nil.
const type_decl*
is_type_decl(const type_or_decl_base* t)
{return dynamic_cast<const type_decl*>(t);}

/// Test whether a type is a type_decl (a builtin type).
///
/// @return the type_decl_sptr for @t if it's type_decl, otherwise,
/// return nil.
type_decl_sptr
is_type_decl(const type_or_decl_base_sptr& t)
{return dynamic_pointer_cast<type_decl>(t);}

/// Test if a type is a real type.
///
/// @param t the type to test.
///
/// @return the real type @p t can be converted to, or nil if @p
/// is not a real type.
type_decl*
is_real_type(const type_or_decl_base* t)
{
  type_decl *type = const_cast<type_decl*>(is_type_decl(t));
  if (!type)
    return nullptr;

  real_type int_type;
  if (!parse_real_type(type->get_name(), int_type))
    return nullptr;

  return type;
}

/// Test if a type is a real type.
///
/// @param t the type to test.
///
/// @return the real type @p t can be converted to, or nil if @p is
/// not a real type.
type_decl_sptr
is_real_type(const type_or_decl_base_sptr& t)
{
  const type_decl_sptr type = is_type_decl(t);
  if (!type)
    return type_decl_sptr();

  real_type int_type;
  if (!parse_real_type(type->get_name(), int_type))
    return type_decl_sptr();

  return type;
}

/// Test if a type is an integral type.
///
/// @param t the type to test.
///
/// @return the integral type @p t can be converted to, or nil if @p
/// is not an integral type.
type_decl*
is_integral_type(const type_or_decl_base* t)
{
  type_decl* type = is_real_type(t);
  if (!type)
    return nullptr;

  real_type rt;
  ABG_ASSERT(parse_real_type(type->get_name(), rt));
  if (rt.get_base_type () == real_type::FLOAT_BASE_TYPE
      || rt.get_base_type() == real_type::DOUBLE_BASE_TYPE)
    return nullptr;

  return type;
}

/// Test if a type is an integral type.
///
/// @param t the type to test.
///
/// @return the integral type @p t can be converted to, or nil if @p
/// is not an integral type.
type_decl_sptr
is_integral_type(const type_or_decl_base_sptr& t)
{
  type_decl_sptr type = is_real_type(t);
  if (!type)
    return type;

  real_type rt;
  ABG_ASSERT(parse_real_type(type->get_name(), rt));
  if (rt.get_base_type () == real_type::FLOAT_BASE_TYPE
      || rt.get_base_type() == real_type::DOUBLE_BASE_TYPE)
    return type_decl_sptr();

  return type;
}

/// Test whether a type is a typedef.
///
/// @param t the type to test for.
///
/// @return the typedef declaration of the @p t, or NULL if it's not a
/// typedef.
typedef_decl_sptr
is_typedef(const type_or_decl_base_sptr t)
{return dynamic_pointer_cast<typedef_decl>(t);}

/// Test whether a type is a typedef.
///
/// @param t the declaration of the type to test for.
///
/// @return the typedef declaration of the @p t, or NULL if it's not a
/// typedef.
const typedef_decl*
is_typedef(const type_base* t)
{return dynamic_cast<const typedef_decl*>(t);}

/// Test whether a type is a typedef.
///
/// @param t the declaration of the type to test for.
///
/// @return the typedef declaration of the @p t, or NULL if it's not a
/// typedef.
typedef_decl*
is_typedef(type_base* t)
{return dynamic_cast<typedef_decl*>(t);}

/// Test whether a type is a typedef.
///
/// @param t the declaration of the type to test for.
///
/// @return the typedef declaration of the @p t, or NULL if it's not a
/// typedef.
const typedef_decl*
is_typedef(const type_or_decl_base* t)
{return dynamic_cast<const typedef_decl*>(t);}

/// Test if a type is an enum. This function looks through typedefs.
///
/// @parm t the type to consider.
///
/// @return the enum_decl if @p t is an @ref enum_decl or null
/// otherwise.
const enum_type_decl*
is_compatible_with_enum_type(const type_base* t)
{
  if (!t)
    return nullptr;

  type_base* ty = const_cast<type_base*>(peel_typedef_type(t));
  return is_enum_type(ty);
}

/// Test if a type is an enum. This function looks through typedefs.
///
/// @parm t the type to consider.
///
/// @return the enum_decl if @p t is an @ref enum_decl or null
/// otherwise.
enum_type_decl_sptr
is_compatible_with_enum_type(const type_base_sptr& t)
{
  if (!t)
    return enum_type_decl_sptr();

  // Normally we should strip typedefs entirely, but this is
  // potentially costly, especially on binaries with huge changesets
  // like the Linux Kernel.  So we just get the leaf types for now.
  //
  // Maybe there should be an option by which users accepts to pay the
  // CPU usage toll in exchange for finer filtering?

  // type_base_sptr ty = strip_typedef(t);
  type_base_sptr ty = peel_typedef_type(t);;
  return is_enum_type(ty);
}

/// Test if a type is an enum. This function looks through typedefs.
///
/// @parm t the type to consider.
///
/// @return the enum_decl if @p t is an @ref enum_decl or null
/// otherwise.
enum_type_decl_sptr
is_compatible_with_enum_type(const decl_base_sptr& t)
{return is_compatible_with_enum_type(is_type(t));}

/// Test if a decl is an enum_type_decl
///
/// @param d the decl to test for.
///
/// @return the enum_type_decl* if @p d is an enum, nil otherwise.
const enum_type_decl*
is_enum_type(const type_or_decl_base* d)
{return dynamic_cast<const enum_type_decl*>(d);}

/// Test if a decl is an enum_type_decl
///
/// @param d the decl to test for.
///
/// @return the enum_type_decl_sptr if @p d is an enum, nil otherwise.
enum_type_decl_sptr
is_enum_type(const type_or_decl_base_sptr& d)
{return dynamic_pointer_cast<enum_type_decl>(d);}

/// Test if a type is a class. This function looks through typedefs.
///
/// @parm t the type to consider.
///
/// @return the class_decl if @p t is a class_decl or null otherwise.
const class_decl*
is_compatible_with_class_type(const type_base* t)
{
  if(!t)
    return nullptr;

  const type_base* ty = peel_typedef_type(t);
  return is_class_type(ty);
}

/// Test if a type is a class. This function looks through typedefs.
///
/// @parm t the type to consider.
///
/// @return the class_decl if @p t is a class_decl or null otherwise.
class_decl_sptr
is_compatible_with_class_type(const type_base_sptr& t)
{
  if (!t)
    return class_decl_sptr();

  // Normally we should strip typedefs entirely, but this is
  // potentially costly, especially on binaries with huge changesets
  // like the Linux Kernel.  So we just get the leaf types for now.
  //
  // Maybe there should be an option by which users accepts to pay the
  // CPU usage toll in exchange for finer filtering?

  // type_base_sptr ty = strip_typedef(t);
  type_base_sptr ty = peel_typedef_type(t);
  return is_class_type(ty);
}

/// Test if a type is a class. This function looks through typedefs.
///
/// @parm t the type to consider.
///
/// @return the class_decl if @p t is a class_decl or null otherwise.
class_decl_sptr
is_compatible_with_class_type(const decl_base_sptr& t)
{return is_compatible_with_class_type(is_type(t));}

/// Test whether a type is a class.
///
/// @parm t the type to consider.
///
/// @return true iff @p t is a class_decl.
bool
is_class_type(const type_or_decl_base& t)
{return is_class_type(&t);}

/// Test whether a type is a class.
///
/// @parm t the type to consider.
///
/// @return the class_decl if @p t is a class_decl or null otherwise.
class_decl*
is_class_type(const type_or_decl_base* t)
{
  if (!t)
    return 0;

  if (t->kind() & type_or_decl_base::CLASS_TYPE)
    return reinterpret_cast<class_decl*>
      (const_cast<type_or_decl_base*>(t)->runtime_type_instance());

  return 0;
}

/// Test whether a type is a class.
///
/// @parm t the type to consider.
///
/// @return the class_decl if @p t is a class_decl or null otherwise.
class_decl_sptr
is_class_type(const type_or_decl_base_sptr& d)
{return dynamic_pointer_cast<class_decl>(d);}

/// Test if the last data member of a class is an array with
/// non-finite data member.
///
/// The flexible data member idiom is a well known C idiom:
/// https://en.wikipedia.org/wiki/Flexible_array_member.
///
/// @param klass the class to consider.
///
/// @return the data member which type is a flexible array, if any, or
/// nil.
var_decl_sptr
has_flexible_array_data_member(const class_decl& klass)
{
  var_decl_sptr nil;
  const class_or_union::data_members& dms = klass.get_data_members();
  if (dms.empty())
    return nil;

  if (array_type_def_sptr array = is_array_type(dms.back()->get_type()))
    {// The type of the last data member is an array.
      if (array->is_non_finite())
    // The array has a non-finite size.  We are thus looking at a
    // flexible array data member.  Let's return it.
    return dms.back();
    }

  return nil;
}

/// Test if the last data member of a class is an array with
/// non-finite data member.
///
/// The flexible data member idiom is a well known C idiom:
/// https://en.wikipedia.org/wiki/Flexible_array_member.
///
/// @param klass the class to consider.
///
/// @return the data member which type is a flexible array, if any, or
/// nil.
var_decl_sptr
has_flexible_array_data_member(const class_decl* klass)
{
  if (!klass)
    return var_decl_sptr();

  return has_flexible_array_data_member(*klass);
}

/// Test if the last data member of a class is an array with
/// non-finite data member.
///
/// The flexible data member idiom is a well known C idiom:
/// https://en.wikipedia.org/wiki/Flexible_array_member.
///
/// @param klass the class to consider.
///
/// @return the data member which type is a flexible array, if any, or
/// nil.
var_decl_sptr
has_flexible_array_data_member(const class_decl_sptr& klass)
{return has_flexible_array_data_member(klass.get());}

/// Test if the last data member of a class is an array with
/// one element.
///
/// An array with one element is a way to mimic the flexible data
/// member idiom that was later standardized in C99.
///
/// To learn more about the flexible data member idiom, please
/// consider reading :
/// https://en.wikipedia.org/wiki/Flexible_array_member.
///
/// The various ways of representing that idiom pre-standardization
/// are presented in this article:
/// https://developers.redhat.com/articles/2022/09/29/benefits-limitations-flexible-array-members#
///
/// @param klass the class to consider.
///
/// @return the data member which type is a fake flexible array, if
/// any, or nil.
var_decl_sptr
has_fake_flexible_array_data_member(const class_decl& klass)
{
  var_decl_sptr nil;
  const class_or_union::data_members& dms = klass.get_data_members();
  if (dms.empty())
    return nil;

  if (array_type_def_sptr array = is_array_type(dms.back()->get_type()))
    {// The type of the last data member is an array.
      if (array->get_subranges().size() == 1
      && array->get_subranges()[0]->get_length() == 1)
    // The array has a size of one. We are thus looking at a
    // "fake" flexible array data member.  Let's return it.
    return dms.back();
    }

  return nil;
}

/// Test if the last data member of a class is an array with
/// one element.
///
/// An array with one element is a way to mimic the flexible data
/// member idiom that was later standardized in C99.
///
/// To learn more about the flexible data member idiom, please
/// consider reading :
/// https://en.wikipedia.org/wiki/Flexible_array_member.
///
/// The various ways of representing that idiom pre-standardization
/// are presented in this article:
/// https://developers.redhat.com/articles/2022/09/29/benefits-limitations-flexible-array-members#
///
/// @param klass the class to consider.
///
/// @return the data member which type is a fake flexible array, if
/// any, or nil.
var_decl_sptr
has_fake_flexible_array_data_member(const class_decl* klass)
{return has_fake_flexible_array_data_member(*klass);}

/// Test if the last data member of a class is an array with
/// one element.
///
/// An array with one element is a way to mimic the flexible data
/// member idiom that was later standardized in C99.
///
/// To learn more about the flexible data member idiom, please
/// consider reading :
/// https://en.wikipedia.org/wiki/Flexible_array_member.
///
/// The various ways of representing that idiom pre-standardization
/// are presented in this article:
/// https://developers.redhat.com/articles/2022/09/29/benefits-limitations-flexible-array-members#
///
/// @param klass the class to consider.
///
/// @return the data member which type is a fake flexible array, if
/// any, or nil.
var_decl_sptr
has_fake_flexible_array_data_member(const class_decl_sptr& klass)
{return has_fake_flexible_array_data_member(klass.get());}

/// Test wheter a type is a declaration-only class.
///
/// @param t the type to considier.
///
/// @param look_through_decl_only if true, then look through the
/// decl-only class to see if it actually has a class definition in
/// the same ABI corpus.
///
/// @return true iff @p t is a declaration-only class.
bool
is_declaration_only_class_or_union_type(const type_base *t,
                    bool look_through_decl_only)
{
  if (class_or_union *klass = is_class_or_union_type(t))
    {
      if (look_through_decl_only)
    klass = look_through_decl_only_class(klass);
      return klass->get_is_declaration_only();
    }
  return false;
}

/// Test wheter a type is a declaration-only class.
///
/// @param t the type to considier.
///
/// @param look_through_decl_only if true, then look through the
/// decl-only class to see if it actually has a class definition in
/// the same ABI corpus.
///
/// @return true iff @p t is a declaration-only class.
bool
is_declaration_only_class_or_union_type(const type_base_sptr& t,
                    bool look_through_decl_only)
{return is_declaration_only_class_or_union_type(t.get(), look_through_decl_only);}

/// Test wheter a type is a declaration-only class.
///
/// @param t the type to considier.
///
/// @param look_through_decl_only if true, then look through the
/// decl-only class to see if it actually has a class definition in
/// the same ABI corpus.
///
/// @return true iff @p t is a declaration-only class.
bool
is_declaration_only_class_type(const type_base_sptr& t,
                   bool look_through_decl_only)
{return is_declaration_only_class_or_union_type(t.get(), look_through_decl_only);}

/// Test if a type is a @ref class_or_union.
///
/// @param t the type to consider.
///
/// @return the @ref class_or_union is @p is a @ref class_or_union, or
/// nil otherwise.
class_or_union*
is_class_or_union_type(const type_or_decl_base* t)
{return dynamic_cast<class_or_union*>(const_cast<type_or_decl_base*>(t));}

/// Test if a type is a @ref class_or_union.
///
/// @param t the type to consider.
///
/// @return the @ref class_or_union is @p is a @ref class_or_union, or
/// nil otherwise.
shared_ptr<class_or_union>
is_class_or_union_type(const shared_ptr<type_or_decl_base>& t)
{return dynamic_pointer_cast<class_or_union>(t);}

/// Test if two class or union types are of the same kind.
///
/// @param first the first type to consider.
///
/// @param second the second type to consider.
///
/// @return true iff @p first is of the same kind as @p second.
bool
class_or_union_types_of_same_kind(const class_or_union* first,
                  const class_or_union* second)
{
  if ((is_class_type(first) && is_class_type(second))
      || (is_union_type(first) && is_union_type(second)))
    return true;

  return false;
}

/// Test if two class or union types are of the same kind.
///
/// @param first the first type to consider.
///
/// @param second the second type to consider.
///
/// @return true iff @p first is of the same kind as @p second.
bool
class_or_union_types_of_same_kind(const class_or_union_sptr& first,
                  const class_or_union_sptr& second)
{return class_or_union_types_of_same_kind(first.get(), second.get());}

/// Test if a type is a @ref union_decl.
///
/// @param t the type to consider.
///
/// @return true iff @p t is a union_decl.
bool
is_union_type(const type_or_decl_base& t)
{return is_union_type(&t);}

/// Test if a type is a @ref union_decl.
///
/// @param t the type to consider.
///
/// @return the @ref union_decl is @p is a @ref union_decl, or nil
/// otherwise.
union_decl*
is_union_type(const type_or_decl_base* t)
{return dynamic_cast<union_decl*>(const_cast<type_or_decl_base*>(t));}

/// Test if a type is a @ref union_decl.
///
/// @param t the type to consider.
///
/// @return the @ref union_decl is @p is a @ref union_decl, or nil
/// otherwise.
union_decl_sptr
is_union_type(const shared_ptr<type_or_decl_base>& t)
{return dynamic_pointer_cast<union_decl>(t);}

/// Test whether a type is a pointer_type_def.
///
/// @param t the type to test.
///
/// @param look_through_decl_only if this is true, then look through
/// qualified types to see if the underlying type is a
/// pointer_type_def.
///
/// @return the @ref pointer_type_def_sptr if @p t is a
/// pointer_type_def, null otherwise.
const pointer_type_def*
is_pointer_type(const type_or_decl_base* t,
        bool look_through_qualifiers)
{
  if (!t)
    return 0;

  const type_base* type = is_type(t);
  if (look_through_qualifiers)
    type = peel_qualified_type(is_type(t));

  return dynamic_cast<pointer_type_def*>(const_cast<type_base*>(type));
}

/// Test whether a type is a pointer_type_def.
///
/// @param t the type to test.
///
/// @param look_through_decl_only if this is true, then look through
/// qualified types to see if the underlying type is a
/// pointer_type_def.
///
/// @return the @ref pointer_type_def_sptr if @p t is a
/// pointer_type_def, null otherwise.
pointer_type_def_sptr
is_pointer_type(const type_or_decl_base_sptr &t,
        bool look_through_qualifiers)
{
  type_base_sptr type = is_type(t);
  if (look_through_qualifiers)
    type = peel_qualified_type(type);
  return dynamic_pointer_cast<pointer_type_def>(type);
}

/// Test if a type is a pointer to function type.
///
/// @param t the type to consider.
///
/// @return the @ref pointer_type_def_sptr iff @p t is a pointer to
/// function type.
pointer_type_def_sptr
is_pointer_to_function_type(const type_base_sptr& t)
{
  if (pointer_type_def_sptr p = is_pointer_type(t))
    {
      if (is_function_type(p->get_pointed_to_type()))
    return p;
    }
  return pointer_type_def_sptr();
}

/// Test if a type is a pointer to array type.
///
/// @param t the type to consider.
///
/// @return the pointer_type_def_sptr iff @p t is a pointer to array
/// type.
pointer_type_def_sptr
is_pointer_to_array_type(const type_base_sptr& t)
{
  if (pointer_type_def_sptr p = is_pointer_type(t))
    {
      if (is_array_type(p->get_pointed_to_type()))
    return p;
    }
  return pointer_type_def_sptr();
}

/// Test if we are looking at a pointer to a
/// neither-a-pointer-to-an-array-nor-a-function type.
///
/// @param t the type to consider.
///
/// @return the @ref pointer_type_def_sptr type iff @p t is a
/// neither-a-pointer-an-array-nor-a-function type.
pointer_type_def_sptr
is_pointer_to_npaf_type(const type_base_sptr& t)
{
  if (pointer_type_def_sptr p = is_pointer_type(t))
    {
      if (is_npaf_type(p->get_pointed_to_type()))
    return p;
    }
  return pointer_type_def_sptr();
}

/// Test if we are looking at a pointer to pointer to member type.
///
/// @param t the type to consider.
///
/// @return the @ref pointer_type_def_sptr type iff @p t is a pointer
/// to pointer to member type.
pointer_type_def_sptr
is_pointer_to_ptr_to_mbr_type(const type_base_sptr& t)
{
  if (pointer_type_def_sptr p = is_pointer_type(t))
    {
      if (is_ptr_to_mbr_type(p->get_pointed_to_type()))
    return p;
    }
  return pointer_type_def_sptr();
}

/// Test if a type is a typedef, pointer or reference to a decl-only
/// class/union.
///
/// This looks into qualified types too.
///
/// @param t the type to consider.
///
/// @return true iff @p t is a type is a typedef, pointer or reference
/// to a decl-only class/union.
bool
is_typedef_ptr_or_ref_to_decl_only_class_or_union_type(const type_base* t)
{
  const type_base * type =
    peel_typedef_pointer_or_reference_type(t, /*peel_qual_type=*/true);

  if (is_declaration_only_class_or_union_type(type,
                          /*look_through_decl_only=*/true))
    return true;

  return false;
}

/// Test if a type is a typedef of a class or union type, or a typedef
/// of a qualified class or union type.
///
/// Note that if the type is directly a class or union type, the
/// function returns true as well.
///
/// @param t the type to consider.
///
/// @return true iff @p t is a typedef of a class or union type, or a
/// typedef of a qualified class or union type.
bool
is_typedef_of_maybe_qualified_class_or_union_type(const type_base* t)
{
  if (!t)
    return false;

  t = peel_qualified_or_typedef_type(t);
  if (is_class_or_union_type(t))
    return true;

return false;
}

/// Test if a type is a typedef of a class or union type, or a typedef
/// of a qualified class or union type.
///
/// Note that if the type is directly a class or union type, the
/// function returns true as well.
///
/// @param t the type to consider.
///
/// @return true iff @p t is a typedef of a class or union type, or a
/// typedef of a qualified class or union type.
bool
is_typedef_of_maybe_qualified_class_or_union_type(const type_base_sptr& t)
{return is_typedef_of_maybe_qualified_class_or_union_type(t.get());}

/// Test whether a type is a reference_type_def.
///
/// @param t the type to test.
///
/// @param look_through_decl_only if this is true, then look through
/// qualified types to see if the underlying type is a
/// reference_type_def.
///
/// @return the @ref reference_type_def_sptr if @p t is a
/// reference_type_def, null otherwise.
reference_type_def*
is_reference_type(type_or_decl_base* t,
          bool look_through_qualifiers)
{
  const type_base* type = is_type(t);
  if (!type)
    return nullptr;

  if (look_through_qualifiers)
    type = peel_qualified_type(type);
  return dynamic_cast<reference_type_def*>(const_cast<type_base*>(type));
}

/// Test whether a type is a reference_type_def.
///
/// @param t the type to test.
///
/// @param look_through_decl_only if this is true, then look through
/// qualified types to see if the underlying type is a
/// reference_type_def.
///
/// @return the @ref reference_type_def_sptr if @p t is a
/// reference_type_def, null otherwise.
const reference_type_def*
is_reference_type(const type_or_decl_base* t,
          bool look_through_qualifiers)
{
  const type_base* type = is_type(t);

  if (look_through_qualifiers)
    type = peel_qualified_type(type);
  return dynamic_cast<const reference_type_def*>(type);
}

/// Test whether a type is a reference_type_def.
///
/// @param t the type to test.
///
/// @param look_through_decl_only if this is true, then look through
/// qualified types to see if the underlying type is a
/// reference_type_def.
///
/// @return the @ref reference_type_def_sptr if @p t is a
/// reference_type_def, null otherwise.
reference_type_def_sptr
is_reference_type(const type_or_decl_base_sptr& t,
          bool look_through_qualifiers)
{
  type_base_sptr type = is_type(t);
  if (look_through_qualifiers)
    type = peel_qualified_type(type);
  return dynamic_pointer_cast<reference_type_def>(type);
}

/// Test whether a type is a @ref ptr_to_mbr_type.
///
/// @param t the type to test.
///
/// @return the @ref ptr_to_mbr_type* if @p t is a @ref
/// ptr_to_mbr_type type, null otherwise.
const ptr_to_mbr_type*
is_ptr_to_mbr_type(const type_or_decl_base* t,
           bool look_through_qualifiers)
{
  const type_base* type = is_type(t);
  if (look_through_qualifiers)
    type = peel_qualified_type(type);
  return dynamic_cast<const ptr_to_mbr_type*>(type);
}

/// Test whether a type is a @ref ptr_to_mbr_type_sptr.
///
/// @param t the type to test.
///
/// @param look_through_decl_only if this is true, then look through
/// qualified types to see if the underlying type is a
/// ptr_to_mbr_type..
///
/// @return the @ref ptr_to_mbr_type_sptr if @p t is a @ref
/// ptr_to_mbr_type type, null otherwise.
ptr_to_mbr_type_sptr
is_ptr_to_mbr_type(const type_or_decl_base_sptr& t,
           bool look_through_qualifiers)
{
  type_base_sptr type = is_type(t);
  if (look_through_qualifiers)
    type = peel_qualified_type(type);
  return dynamic_pointer_cast<ptr_to_mbr_type>(type);
}

/// Test if a type is equivalent to a pointer to void type.
///
/// Note that this looks trough typedefs or CV qualifiers to look for
/// the void pointer.
///
/// @param type the type to consider.
///
/// @return the actual void pointer if @p is eqivalent to a void
/// pointer or NULL if it's not.
const type_base*
is_void_pointer_type_equivalent(const type_base* type)
{
  type = peel_qualified_or_typedef_type(type);

  const pointer_type_def * t = is_pointer_type(type);
  if (!t)
    return 0;

  // Look through typedefs in the pointed-to type as well.
  type_base * ty = t->get_pointed_to_type().get();
  ty = peel_qualified_or_typedef_type(ty);
  if (ty && ty->get_environment().is_void_type(ty))
    return ty;

  return 0;
}

/// Test if a type is equivalent to a pointer to void type.
///
/// Note that this looks trough typedefs or CV qualifiers to look for
/// the void pointer.
///
/// @param type the type to consider.
///
/// @return the actual void pointer if @p is eqivalent to a void
/// pointer or NULL if it's not.
const type_base*
is_void_pointer_type_equivalent(const type_base& type)
{return is_void_pointer_type_equivalent(&type);}

/// Test if a type is a pointer to void type.
///
/// @param type the type to consider.
///
/// @return the actual void pointer if @p is a void pointer or NULL if
/// it's not.
const type_base*
is_void_pointer_type(const type_base* t)
{
  if (!t)
    return nullptr;

  if (t->get_environment().get_void_pointer_type().get() == t)
    return t;

  const pointer_type_def* ptr = is_pointer_type(t);
  if (!ptr)
    return nullptr;

  if (t->get_environment().is_void_type(ptr->get_pointed_to_type()))
    return t;

  return nullptr;
}

/// Test if a type is a pointer to void type.
///
/// @param type the type to consider.
///
/// @return the actual void pointer if @p is a void pointer or NULL if
/// it's not.
const type_base_sptr
is_void_pointer_type(const type_base_sptr& t)
{
  type_base_sptr nil;
  if (!t)
    return nil;

  if (t->get_environment().get_void_pointer_type().get() == t.get())
    return t;

  const pointer_type_def* ptr = is_pointer_type(t.get());
  if (!ptr)
    return nil;

  if (t->get_environment().is_void_type(ptr->get_pointed_to_type()))
    return t;

  return nil;
}

/// Test whether a type is a reference_type_def.
///
/// @param t the type to test.
///
/// @return the @ref reference_type_def_sptr if @p t is a
/// reference_type_def, null otherwise.
qualified_type_def*
is_qualified_type(const type_or_decl_base* t)
{return dynamic_cast<qualified_type_def*>(const_cast<type_or_decl_base*>(t));}

/// Test whether a type is a qualified_type_def.
///
/// @param t the type to test.
///
/// @return the @ref qualified_type_def_sptr if @p t is a
/// qualified_type_def, null otherwise.
qualified_type_def_sptr
is_qualified_type(const type_or_decl_base_sptr& t)
{return dynamic_pointer_cast<qualified_type_def>(t);}

/// Test whether a type is a function_type.
///
/// @param t the type to test.
///
/// @return the @ref function_type_sptr if @p t is a
/// function_type, null otherwise.
function_type_sptr
is_function_type(const type_or_decl_base_sptr& t)
{return dynamic_pointer_cast<function_type>(t);}

/// Test whether a type is a function_type.
///
/// @param t the type to test.
///
/// @return the @ref function_type_sptr if @p t is a
/// function_type, null otherwise.
function_type*
is_function_type(type_or_decl_base* t)
{return dynamic_cast<function_type*>(t);}

/// Test whether a type is a function_type.
///
/// @param t the type to test.
///
/// @return the @ref function_type_sptr if @p t is a
/// function_type, null otherwise.
const function_type*
is_function_type(const type_or_decl_base* t)
{return dynamic_cast<const function_type*>(t);}

/// Test whether a type is a method_type.
///
/// @param t the type to test.
///
/// @return the @ref method_type_sptr if @p t is a
/// method_type, null otherwise.
method_type_sptr
is_method_type(const type_or_decl_base_sptr& t)
{return dynamic_pointer_cast<method_type>(t);}

/// Test whether a type is a method_type.
///
/// @param t the type to test.
///
/// @return the @ref method_type_sptr if @p t is a
/// method_type, null otherwise.
const method_type*
is_method_type(const type_or_decl_base* t)
{return dynamic_cast<const method_type*>(t);}

/// Test whether a type is a method_type.
///
/// @param t the type to test.
///
/// @return the @ref method_type_sptr if @p t is a
/// method_type, null otherwise.
method_type*
is_method_type(type_or_decl_base* t)
{return dynamic_cast<method_type*>(t);}

/// If a class (or union) is a decl-only class, get its definition.
/// Otherwise, just return the initial class.
///
/// @param the_class the class (or union) to consider.
///
/// @return either the definition of the class, or the class itself.
class_or_union*
look_through_decl_only_class(class_or_union* the_class)
{return is_class_or_union_type(look_through_decl_only(the_class));}

/// If a class (or union) is a decl-only class, get its definition.
/// Otherwise, just return the initial class.
///
/// @param the_class the class (or union) to consider.
///
/// @return either the definition of the class, or the class itself.
class_or_union_sptr
look_through_decl_only_class(const class_or_union& the_class)
{return is_class_or_union_type(look_through_decl_only(the_class));}

/// If a class (or union) is a decl-only class, get its definition.
/// Otherwise, just return the initial class.
///
/// @param klass the class (or union) to consider.
///
/// @return either the definition of the class, or the class itself.
class_or_union_sptr
look_through_decl_only_class(class_or_union_sptr klass)
{return is_class_or_union_type(look_through_decl_only(klass));}

/// If an enum is a decl-only enum, get its definition.
/// Otherwise, just return the initial enum.
///
/// @param the_enum the enum to consider.
///
/// @return either the definition of the enum, or the enum itself.
enum_type_decl_sptr
look_through_decl_only_enum(const enum_type_decl& the_enum)
{return is_enum_type(look_through_decl_only(the_enum));}

/// If an enum is a decl-only enum, get its definition.
/// Otherwise, just return the initial enum.
///
/// @param enom the enum to consider.
///
/// @return either the definition of the enum, or the enum itself.
enum_type_decl_sptr
look_through_decl_only_enum(enum_type_decl_sptr enom)
{return is_enum_type(look_through_decl_only(enom));}

/// If a decl is decl-only get its definition.  Otherwise, just return nil.
///
/// @param d the decl to consider.
///
/// @return either the definition of the decl, or nil.
decl_base_sptr
look_through_decl_only(const decl_base& d)
{
  decl_base_sptr decl;
  if (d.get_is_declaration_only())
    decl = d.get_definition_of_declaration();

  if (!decl)
    return decl;

  while (decl->get_is_declaration_only()
     && decl->get_definition_of_declaration())
    decl = decl->get_definition_of_declaration();

  return decl;
}

/// If a decl is decl-only enum, get its definition.  Otherwise, just
/// return the initial decl.
///
/// @param d the decl to consider.
///
/// @return either the definition of the enum, or the decl itself.
decl_base*
look_through_decl_only(decl_base* d)
{
  if (!d)
    return d;

  decl_base* result = look_through_decl_only(*d).get();
  if (!result)
    result = d;

  return result;
}

/// If a decl is decl-only get its definition.  Otherwise, just return nil.
///
/// @param d the decl to consider.
///
/// @return either the definition of the decl, or nil.
decl_base_sptr
look_through_decl_only(const decl_base_sptr& d)
{
  if (!d)
    return d;

  decl_base_sptr result = look_through_decl_only(*d);
  if (!result)
    result = d;

  return result;
}

/// If a type is is decl-only, then get its definition.  Otherwise,
/// just return the initial type.
///
/// @param d the decl to consider.
///
/// @return either the definition of the decl, or the initial type.
type_base*
look_through_decl_only_type(type_base* t)
{
  decl_base* d = is_decl(t);
  if (!d)
    return t;
  d = look_through_decl_only(d);
  return is_type(d);
}

/// If a type is is decl-only, then get its definition.  Otherwise,
/// just return the initial type.
///
/// @param d the decl to consider.
///
/// @return either the definition of the decl, or the initial type.
type_base_sptr
look_through_decl_only_type(const type_base_sptr& t)
{
  decl_base_sptr d = is_decl(t);
  if (!d)
    return t;
  d = look_through_decl_only(d);
  return is_type(d);
}

/// Tests if a declaration is a variable declaration.
///
/// @param decl the decl to test.
///
/// @return the var_decl_sptr iff decl is a variable declaration; nil
/// otherwise.
var_decl*
is_var_decl(const type_or_decl_base* tod)
{return dynamic_cast<var_decl*>(const_cast<type_or_decl_base*>(tod));}

/// Tests if a declaration is a variable declaration.
///
/// @param decl the decl to test.
///
/// @return the var_decl_sptr iff decl is a variable declaration; nil
/// otherwise.
var_decl_sptr
is_var_decl(const type_or_decl_base_sptr& decl)
{return dynamic_pointer_cast<var_decl>(decl);}

/// Tests if a declaration is a namespace declaration.
///
/// @param d the decalration to consider.
///
/// @return the namespace declaration if @p d is a namespace.
namespace_decl_sptr
is_namespace(const decl_base_sptr& d)
{return dynamic_pointer_cast<namespace_decl>(d);}

/// Tests if a declaration is a namespace declaration.
///
/// @param d the decalration to consider.
///
/// @return the namespace declaration if @p d is a namespace.
namespace_decl*
is_namespace(const decl_base* d)
{return dynamic_cast<namespace_decl*>(const_cast<decl_base*>(d));}

/// Tests whether a decl is a template parameter composition type.
///
/// @param decl the declaration to consider.
///
/// @return true iff decl is a template parameter composition type.
bool
is_template_parm_composition_type(const shared_ptr<decl_base> decl)
{
  return (decl
      && is_at_template_scope(decl)
      && is_type(decl)
      && !is_template_parameter(decl));
}

/// Test whether a decl is the pattern of a function template.
///
/// @param decl the decl to consider.
///
/// @return true iff decl is the pattern of a function template.
bool
is_function_template_pattern(const shared_ptr<decl_base> decl)
{
  return (decl
      && dynamic_pointer_cast<function_decl>(decl)
      && dynamic_cast<template_decl*>(decl->get_scope()));
}

/// Test if a type is an array_type_def.
///
/// @param type the type to consider.
///
/// @return true iff @p type is an array_type_def.
array_type_def*
is_array_type(const type_or_decl_base* type,
          bool look_through_qualifiers)
{
  const type_base* t = is_type(type);

  if (look_through_qualifiers)
    t = peel_qualified_type(t);
  return dynamic_cast<array_type_def*>(const_cast<type_base*>(t));
}

/// Test if a type is an array_type_def.
///
/// @param type the type to consider.
///
/// @return true iff @p type is an array_type_def.
array_type_def_sptr
is_array_type(const type_or_decl_base_sptr& type,
          bool look_through_qualifiers)
{
  type_base_sptr t = is_type(type);

  if (look_through_qualifiers)
    t = peel_qualified_type(t);
  return dynamic_pointer_cast<array_type_def>(t);
}

/// Tests if the element of a given array is a qualified type.
///
/// @param array the array type to consider.
///
/// @return the qualified element of the array iff it's a qualified
/// type.  Otherwise, return a nil object.
qualified_type_def_sptr
is_array_of_qualified_element(const array_type_def_sptr& array)
{
  if (!array)
    return qualified_type_def_sptr();

  return is_qualified_type(array->get_element_type());
}

/// Test if an array type is an array to a qualified element type.
///
/// @param type the array type to consider.
///
/// @return true the array @p type iff it's an array to a qualified
/// element type.
array_type_def_sptr
is_array_of_qualified_element(const type_base_sptr& type)
{
  if (array_type_def_sptr array = is_array_type(type))
    if (is_array_of_qualified_element(array))
      return array;

  return array_type_def_sptr();
}

/// Test if a type is a typedef of an array.
///
/// Note that the function looks through qualified and typedefs types
/// of the underlying type of the current typedef.  In other words, if
/// we are looking at a typedef of a CV-qualified array, or at a
/// typedef of a CV-qualified typedef of an array, this function will
/// still return TRUE.
///
/// @param t the type to consider.
///
/// @return true if t is a typedef which underlying type is an array.
/// That array might be either cv-qualified array or a typedef'ed
/// array, or a combination of both.
array_type_def_sptr
is_typedef_of_array(const type_base_sptr& t)
{
  array_type_def_sptr result;

  if (typedef_decl_sptr typdef = is_typedef(t))
    {
      type_base_sptr u =
    peel_qualified_or_typedef_type(typdef->get_underlying_type());
      result = is_array_type(u);
    }

  return result;
}

/// Test if a type is an array_type_def::subrange_type.
///
/// @param type the type to consider.
///
/// @return the array_type_def::subrange_type which @p type is a type
/// of, or nil if it's not of that type.
array_type_def::subrange_type*
is_subrange_type(const type_or_decl_base *type)
{
  return dynamic_cast<array_type_def::subrange_type*>
    (const_cast<type_or_decl_base*>(type));
}

/// Test if a type is an array_type_def::subrange_type.
///
/// @param type the type to consider.
///
/// @return the array_type_def::subrange_type which @p type is a type
/// of, or nil if it's not of that type.
array_type_def::subrange_sptr
is_subrange_type(const type_or_decl_base_sptr &type)
{return dynamic_pointer_cast<array_type_def::subrange_type>(type);}

/// Tests whether a decl is a template.
///
/// @param decl the decl to consider.
///
/// @return true iff decl is a function template, class template, or
/// template template parameter.
bool
is_template_decl(const decl_base_sptr& decl)
{return decl && dynamic_pointer_cast<template_decl>(decl);}

/// This enum describe the kind of entity to lookup, while using the
/// lookup API.
enum lookup_entity_kind
{
  LOOKUP_ENTITY_TYPE,
  LOOKUP_ENTITY_VAR,
};

/// Find the first relevant delimiter (the "::" string) in a fully
/// qualified C++ type name, starting from a given position.  The
/// delimiter returned separates a type name from the name of its
/// context.
///
/// This is supposed to work correctly on names in cases like this:
///
///    foo<ns1::name1, ns2::name2>
///
/// In that case when called with with parameter @p begin set to 0, no
/// delimiter is returned, because the type name in this case is:
/// 'foo<ns1::name1, ns2::name2>'.
///
/// But in this case:
///
///   foo<p1, bar::name>::some_type
///
/// The "::" returned is the one right before 'some_type'.
///
/// @param fqn the fully qualified name of the type to consider.
///
/// @param begin the position from which to look for the delimiter.
///
/// @param delim_pos out parameter. Is set to the position of the
/// delimiter iff the function returned true.
///
/// @return true iff the function found and returned the delimiter.
static bool
find_next_delim_in_cplus_type(const string& fqn,
                  size_t        begin,
                  size_t&       delim_pos)
{
  int angle_count = 0;
  bool found = false;
  size_t i = begin;
  for (; i < fqn.size(); ++i)
    {
      if (fqn[i] == '<')
    ++angle_count;
      else if (fqn[i] == '>')
    --angle_count;
      else if (i + 1 < fqn.size()
           && !angle_count
           && fqn[i] == ':'
           && fqn[i+1] == ':')
    {
      delim_pos = i;
      found = true;
      break;
    }
    }
  return found;
}

/// Decompose a fully qualified name into the list of its components.
///
/// @param fqn the fully qualified name to decompose.
///
/// @param comps the resulting list of component to fill.
void
fqn_to_components(const string& fqn,
          list<string>& comps)
{
  string::size_type fqn_size = fqn.size(), comp_begin = 0, comp_end = fqn_size;
  do
    {
      if (!find_next_delim_in_cplus_type(fqn, comp_begin, comp_end))
    comp_end = fqn_size;

      string comp = fqn.substr(comp_begin, comp_end - comp_begin);
      comps.push_back(comp);

      comp_begin = comp_end + 2;
      if (comp_begin >= fqn_size)
    break;
    } while (true);
}

/// Turn a set of qualified name components (that name a type) into a
/// qualified name string.
///
/// @param comps the name components
///
/// @return the resulting string, which would be the qualified name of
/// a type.
string
components_to_type_name(const list<string>& comps)
{
  string result;
  for (list<string>::const_iterator c = comps.begin();
       c != comps.end();
       ++c)
    if (c == comps.begin())
      result = *c;
    else
      result += "::" + *c;
  return result;
}

/// This predicate returns true if a given container iterator points
/// to the last element of the container, false otherwise.
///
/// @tparam T the type of the container of the iterator.
///
/// @param container the container the iterator points into.
///
/// @param i the iterator to consider.
///
/// @return true iff the iterator points to the last element of @p
/// container.
template<typename T>
static bool
iterator_is_last(T& container,
         typename T::const_iterator i)
{
  typename T::const_iterator next = i;
  ++next;
  return (next == container.end());
}

//--------------------------------
// <type and decls lookup stuff>
// ------------------------------

/// Lookup all the type*s* that have a given fully qualified name.
///
/// @param type_name the fully qualified name of the type to
/// lookup.
///
/// @param type_map the map to look into.
///
/// @return the vector containing the types named @p type_name.  If
/// the lookup didn't yield any type, then this function returns nil.
static const type_base_wptrs_type*
lookup_types_in_map(const interned_string& type_name,
            const istring_type_base_wptrs_map_type& type_map)
{
  istring_type_base_wptrs_map_type::const_iterator i = type_map.find(type_name);
  if (i != type_map.end())
    return &i->second;
  return 0;
}

/// Lookup a type (with a given name) in a map that associates a type
/// name to a type.  If there are several types with a given name,
/// then try to return the first one that is not decl-only.
/// Otherwise, return the last of such types, that is, the last one
/// that got registered.
///
/// @tparam TypeKind the type of the type this function is supposed to
/// return.
///
/// @param type_name the name of the type to lookup.
///
/// @param type_map the map in which to look.
///
/// @return a shared_ptr to the type found.  If no type was found or
/// if the type found was not of type @p TypeKind then the function
/// returns nil.
template <class TypeKind>
static shared_ptr<TypeKind>
lookup_type_in_map(const interned_string& type_name,
           const istring_type_base_wptrs_map_type& type_map)
{
  istring_type_base_wptrs_map_type::const_iterator i = type_map.find(type_name);
  if (i != type_map.end())
    {
      // Walk the types that have the name "type_name" and return the
      // first one that is not declaration-only ...
      for (auto j : i->second)
    {
      type_base_sptr t(j);
      decl_base_sptr d = is_decl(t);
      if (d && !d->get_is_declaration_only())
        return dynamic_pointer_cast<TypeKind>(type_base_sptr(j));
    }
      // ... or return the last type with the name "type_name" that
      // was recorded.  It's likely to be declaration-only if we
      // reached this point.
      return dynamic_pointer_cast<TypeKind>(type_base_sptr(i->second.back()));
    }
  return shared_ptr<TypeKind>();
}

/// Lookup a basic type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param type_name the name of the basic type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the basic type found or nil if no basic type was found.
type_decl_sptr
lookup_basic_type(const interned_string& type_name, const translation_unit& tu)
{
  return lookup_type_in_map<type_decl>(type_name,
                       tu.get_types().basic_types());
}

/// Lookup a basic type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param type_name the name of the basic type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the basic type found or nil if no basic type was found.
type_decl_sptr
lookup_basic_type(const string& type_name, const translation_unit& tu)
{
  const environment& env = tu.get_environment();

  interned_string s = env.intern(type_name);
  return lookup_basic_type(s, tu);
}

/// Lookup a class type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param fqn the fully qualified name of the class type node to look
/// up.
///
/// @param tu the translation unit to perform lookup from.
///
/// @return the declaration of the class type IR node found, NULL
/// otherwise.
class_decl_sptr
lookup_class_type(const string& fqn, const translation_unit& tu)
{
  const environment& env = tu.get_environment();
  interned_string s = env.intern(fqn);
  return lookup_class_type(s, tu);
}

/// Lookup a class type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param type_name the name of the class type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the class type found or nil if no class type was found.
class_decl_sptr
lookup_class_type(const interned_string& type_name, const translation_unit& tu)
{
  return lookup_type_in_map<class_decl>(type_name,
                    tu.get_types().class_types());
}

/// Lookup a union type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param type_name the name of the union type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the union type found or nil if no union type was found.
union_decl_sptr
lookup_union_type(const interned_string& type_name, const translation_unit& tu)
{
  return lookup_type_in_map<union_decl>(type_name,
                    tu.get_types().union_types());
}

/// Lookup a union type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param fqn the fully qualified name of the type to lookup.
///
/// @param tu the translation unit to look into.
///
/// @return the union type found or nil if no union type was found.
union_decl_sptr
lookup_union_type(const string& fqn, const translation_unit& tu)
{
  const environment& env = tu.get_environment();
  interned_string s = env.intern(fqn);
  return lookup_union_type(s, tu);
}

/// Lookup a union type in a given corpus, from its location.
///
/// @param loc the location of the union type to look for.
///
/// @param corp the corpus to look it from.
///
/// @return the resulting union_decl.
union_decl_sptr
lookup_union_type_per_location(const interned_string &loc, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m =
    corp.get_type_per_loc_map().union_types();
  union_decl_sptr result = lookup_type_in_map<union_decl>(loc, m);

  return result;
}

/// Lookup a union type in a given corpus, from its location.
///
/// @param loc the location of the union type to look for.
///
/// @param corp the corpus to look it from.
///
/// @return the resulting union_decl.
union_decl_sptr
lookup_union_type_per_location(const string& loc, const corpus& corp)
{
  const environment& env = corp.get_environment();
  return lookup_union_type_per_location(env.intern(loc), corp);
}

/// Lookup an enum type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param type_name the name of the enum type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the enum type found or nil if no enum type was found.
enum_type_decl_sptr
lookup_enum_type(const interned_string& type_name, const translation_unit& tu)
{
  return lookup_type_in_map<enum_type_decl>(type_name,
                        tu.get_types().enum_types());
}

/// Lookup an enum type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param type_name the name of the enum type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the enum type found or nil if no enum type was found.
enum_type_decl_sptr
lookup_enum_type(const string& type_name, const translation_unit& tu)
{
  const environment& env = tu.get_environment();
  interned_string s = env.intern(type_name);
  return lookup_enum_type(s, tu);
}

/// Lookup a typedef type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param type_name the name of the typedef type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the typedef type found or nil if no typedef type was
/// found.
typedef_decl_sptr
lookup_typedef_type(const interned_string& type_name,
            const translation_unit& tu)
{
  return lookup_type_in_map<typedef_decl>(type_name,
                      tu.get_types().typedef_types());
}

/// Lookup a typedef type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param type_name the name of the typedef type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the typedef type found or nil if no typedef type was
/// found.
typedef_decl_sptr
lookup_typedef_type(const string& type_name, const translation_unit& tu)
{
  const environment& env = tu.get_environment();
  interned_string s = env.intern(type_name);
  return lookup_typedef_type(s, tu);
}

/// Lookup a qualified type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param type_name the name of the qualified type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the qualified type found or nil if no qualified type was
/// found.
qualified_type_def_sptr
lookup_qualified_type(const interned_string& type_name,
              const translation_unit& tu)
{
  const type_maps& m = tu.get_types();
  return lookup_type_in_map<qualified_type_def>(type_name,
                        m.qualified_types());
}

/// Lookup a qualified type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param underlying_type the underying type of the qualified type to
/// look up.
///
/// @param quals the CV-qualifiers of the qualified type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the qualified type found or nil if no qualified type was
/// found.
qualified_type_def_sptr
lookup_qualified_type(const type_base_sptr& underlying_type,
              qualified_type_def::CV quals,
              const translation_unit& tu)
{
  interned_string type_name = get_name_of_qualified_type(underlying_type,
                             quals);
  return lookup_qualified_type(type_name, tu);
}

/// Lookup a pointer type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param type_name the name of the pointer type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the pointer type found or nil if no pointer type was
/// found.
pointer_type_def_sptr
lookup_pointer_type(const interned_string& type_name,
            const translation_unit& tu)
{
  const type_maps& m = tu.get_types();
  return lookup_type_in_map<pointer_type_def>(type_name,
                          m.pointer_types());
}

/// Lookup a pointer type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param type_name the name of the pointer type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the pointer type found or nil if no pointer type was
/// found.
pointer_type_def_sptr
lookup_pointer_type(const string& type_name, const translation_unit& tu)
{
  const environment& env = tu.get_environment();
  interned_string s = env.intern(type_name);
  return lookup_pointer_type(s, tu);
}

/// Lookup a pointer type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param pointed_to_type the pointed-to-type of the pointer to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the pointer type found or nil if no pointer type was
/// found.
pointer_type_def_sptr
lookup_pointer_type(const type_base_sptr& pointed_to_type,
            const translation_unit& tu)
{
  type_base_sptr t = look_through_decl_only_type(pointed_to_type);
  interned_string type_name = get_name_of_pointer_to_type(*t);
  return lookup_pointer_type(type_name, tu);
}

/// Lookup a reference type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param type_name the name of the reference type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the reference type found or nil if no reference type was
/// found.
reference_type_def_sptr
lookup_reference_type(const interned_string& type_name,
              const translation_unit& tu)
{
  const type_maps& m = tu.get_types();
  return lookup_type_in_map<reference_type_def>(type_name,
                        m.reference_types());
}

/// Lookup a reference type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param pointed_to_type the pointed-to-type of the reference to
/// look up.
///
/// @param tu the translation unit to look into.
///
/// @return the reference type found or nil if no reference type was
/// found.
const reference_type_def_sptr
lookup_reference_type(const type_base_sptr& pointed_to_type,
              bool lvalue_reference,
              const translation_unit& tu)
{
  interned_string type_name =
    get_name_of_reference_to_type(*look_through_decl_only_type(pointed_to_type),
                  lvalue_reference);
  return lookup_reference_type(type_name, tu);
}

/// Lookup an array type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param type_name the name of the array type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the array type found or nil if no array type was found.
array_type_def_sptr
lookup_array_type(const interned_string& type_name,
          const translation_unit& tu)
{
  const type_maps& m = tu.get_types();
  return lookup_type_in_map<array_type_def>(type_name,
                        m.array_types());
}

/// Lookup a function type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param type_name the name of the type to lookup.
///
/// @param tu the translation unit to look into.
///
/// @return the function type found, or NULL of none was found.
function_type_sptr
lookup_function_type(const interned_string& type_name,
             const translation_unit& tu)
{
  const type_maps& m = tu.get_types();
  return lookup_type_in_map<function_type>(type_name,
                       m.function_types());
}

/// Lookup a function type from a translation unit.
///
/// This walks all the function types held by the translation unit and
/// compare their sub-type *names*.  If the names match then return
/// the function type found in the translation unit.
///
/// @param t the function type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the function type found, or NULL of none was found.
function_type_sptr
lookup_function_type(const function_type& t,
             const translation_unit& tu)
{
  interned_string type_name = get_type_name(t);
  return lookup_function_type(type_name, tu);
}

/// Lookup a function type from a translation unit.
///
/// This is done by looking the type up in the type map that is
/// maintained in the translation unit.  So this is as fast as
/// possible.
///
/// @param t the function type to look for.
///
/// @param tu the translation unit to look into.
///
/// @return the function type found, or NULL of none was found.
function_type_sptr
lookup_function_type(const function_type_sptr& t,
             const translation_unit& tu)
{return lookup_function_type(*t, tu);}

/// Lookup a type in a translation unit.
///
/// @param fqn the fully qualified name of the type to lookup.
///
/// @param tu the translation unit to consider.
///
/// @return the declaration of the type if found, NULL otherwise.
const type_base_sptr
lookup_type(const interned_string& fqn,
        const translation_unit& tu)
{
  type_base_sptr result;
  ((result = lookup_typedef_type(fqn, tu))
   || (result = lookup_class_type(fqn, tu))
   || (result = lookup_union_type(fqn, tu))
   || (result = lookup_enum_type(fqn, tu))
   || (result = lookup_qualified_type(fqn, tu))
   || (result = lookup_pointer_type(fqn, tu))
   || (result = lookup_reference_type(fqn, tu))
   || (result = lookup_array_type(fqn, tu))
   || (result = lookup_function_type(fqn, tu))
   || (result = lookup_basic_type(fqn, tu)));

  return result;
}

/// Lookup a type in a translation unit, starting from the global
/// namespace.
///
/// @param fqn the fully qualified name of the type to lookup.
///
/// @param tu the translation unit to consider.
///
/// @return the declaration of the type if found, NULL otherwise.
type_base_sptr
lookup_type(const string& fqn, const translation_unit& tu)
{
  const environment&env = tu.get_environment();
  interned_string ifqn = env.intern(fqn);
  return lookup_type(ifqn, tu);
}

/// Lookup a type from a translation unit.
///
/// @param fqn the components of the fully qualified name of the node
/// to look up.
///
/// @param tu the translation unit to perform lookup from.
///
/// @return the declaration of the IR node found, NULL otherwise.
const type_base_sptr
lookup_type(const type_base_sptr type,
        const translation_unit& tu)
{
  interned_string type_name = get_type_name(type);
  return lookup_type(type_name, tu);
}

/// Lookup a type in a scope.
///
/// This is really slow as it walks the member types of the scope in
/// sequence to find the type with a given name.
///
/// If possible, users should prefer looking up types from the
/// enclosing translation unit or even ABI corpus because both the
/// translation unit and the corpus have a map of type, indexed by
/// their name.  Looking up a type from those maps is thus much
/// faster.
///
/// @param fqn the fully qualified name of the type to lookup.
///
/// @param skope the scope to look into.
///
/// @return the declaration of the type if found, NULL otherwise.
const type_base_sptr
lookup_type_in_scope(const string& fqn,
             const scope_decl_sptr& skope)
{
  list<string> comps;
  fqn_to_components(fqn, comps);
  return lookup_type_in_scope(comps, skope);
}

/// Lookup a @ref var_decl in a scope.
///
/// @param fqn the fuly qualified name of the @var_decl to lookup.
///
/// @param skope the scope to look into.
///
/// @return the declaration of the @ref var_decl if found, NULL
/// otherwise.
const decl_base_sptr
lookup_var_decl_in_scope(const string& fqn,
             const scope_decl_sptr& skope)
{
  list<string> comps;
  fqn_to_components(fqn, comps);
  return lookup_var_decl_in_scope(comps, skope);
}

/// A generic function (template) to get the name of a node, whatever
/// node it is.  This has to be specialized for the kind of node we
/// want.
///
/// Note that a node is a member of a scope.
///
/// @tparam NodeKind the kind of node to consider.
///
/// @param node the node to get the name from.
///
/// @return the name of the node.
template<typename NodeKind>
static const interned_string&
get_node_name(shared_ptr<NodeKind> node);

/// Gets the name of a class_decl node.
///
/// @param node the decl_base node to get the name from.
///
/// @return the name of the node.
template<>
const interned_string&
get_node_name(class_decl_sptr node)
{return node->get_name();}

/// Gets the name of a type_base node.
///
/// @param node the type_base node to get the name from.
///
/// @return the name of the node.
template<>
const interned_string&
get_node_name(type_base_sptr node)
{return get_type_declaration(node)->get_name();}

/// Gets the name of a var_decl node.
///
/// @param node the var_decl node to get the name from.
///
/// @return the name of the node.
template<>
const interned_string&
get_node_name(var_decl_sptr node)
{return node->get_name();}

/// Generic function to get the declaration of a given node, whatever
/// it is.  There has to be specializations for the kind of the nodes
/// we want to support.
///
/// @tparam NodeKind the type of the node we are looking at.
///
/// @return the declaration.
template<typename NodeKind>
static decl_base_sptr
convert_node_to_decl(shared_ptr<NodeKind> node);

/// Lookup a node in a given scope.
///
/// @tparam the type of the node to lookup.
///
/// @param fqn the components of the fully qualified name of the node
/// to lookup.
///
/// @param skope the scope to look into.
///
/// @return the declaration of the looked up node, or NULL if it
/// wasn't found.
template<typename NodeKind>
static const type_or_decl_base_sptr
lookup_node_in_scope(const list<string>& fqn,
             const scope_decl_sptr& skope)
{
  type_or_decl_base_sptr resulting_decl;
  shared_ptr<NodeKind> node;
  bool it_is_last = false;
  scope_decl_sptr cur_scope = skope, new_scope, scope;

  for (list<string>::const_iterator c = fqn.begin(); c != fqn.end(); ++c)
    {
      new_scope.reset();
      it_is_last = iterator_is_last(fqn, c);
      for (scope_decl::declarations::const_iterator m =
         cur_scope->get_member_decls().begin();
       m != cur_scope->get_member_decls().end();
       ++m)
    {
      if (!it_is_last)
        {
          // looking for a scope
          scope = dynamic_pointer_cast<scope_decl>(*m);
          if (scope && scope->get_name() == *c)
        {
          new_scope = scope;
          break;
        }
        }
      else
        {
          //looking for a final type.
          node = dynamic_pointer_cast<NodeKind>(*m);
          if (node && get_node_name(node) == *c)
        {
          if (class_decl_sptr cl =
              dynamic_pointer_cast<class_decl>(node))
            if (cl->get_is_declaration_only()
            && !cl->get_definition_of_declaration())
              continue;
          resulting_decl = node;
          break;
        }
        }
    }
      if (!new_scope && !resulting_decl)
    return decl_base_sptr();
      cur_scope = new_scope;
    }
  ABG_ASSERT(resulting_decl);
  return resulting_decl;
}

/// lookup a type in a scope.
///
///
/// This is really slow as it walks the member types of the scope in
/// sequence to find the type with a given name.
///
/// If possible, users should prefer looking up types from the
/// enclosing translation unit or even ABI corpus because both the
/// translation unit and the corpus have a map of type, indexed by
/// their name.  Looking up a type from those maps is thus much
/// faster.
///
/// @param comps the components of the fully qualified name of the
/// type to lookup.
///
/// @param skope the scope to look into.
///
/// @return the declaration of the type found.
const type_base_sptr
lookup_type_in_scope(const list<string>& comps,
             const scope_decl_sptr& scope)
{return is_type(lookup_node_in_scope<type_base>(comps, scope));}

/// lookup a type in a scope.
///
/// This is really slow as it walks the member types of the scope in
/// sequence to find the type with a given name.
///
/// If possible, users should prefer looking up types from the
/// enclosing translation unit or even ABI corpus because both the
/// translation unit and the corpus have a map of type, indexed by
/// their name.  Looking up a type from those maps is thus much
/// faster.
///
/// @param type the type to look for.
///
/// @param access_path a vector of scopes the path of scopes to follow
/// before reaching the scope into which to look for @p type.  Note
/// that the deepest scope (the one immediately containing @p type) is
/// at index 0 of this vector, and the top-most scope is the last
/// element of the vector.
///
/// @param scope the top-most scope into which to look for @p type.
///
/// @return the scope found in @p scope, or NULL if it wasn't found.
static const type_base_sptr
lookup_type_in_scope(const type_base& type,
             const vector<scope_decl*>& access_path,
             const scope_decl* scope)
{
  vector<scope_decl*> a = access_path;
  type_base_sptr result;

  scope_decl* first_scope = 0;
  if (!a.empty())
    {
      first_scope = a.back();
      ABG_ASSERT(first_scope->get_name() == scope->get_name());
      a.pop_back();
    }

  if (a.empty())
    {
      interned_string n = get_type_name(type, false);
      for (scope_decl::declarations::const_iterator i =
         scope->get_member_decls().begin();
       i != scope->get_member_decls().end();
       ++i)
    if (is_type(*i) && (*i)->get_name() == n)
      {
        result = is_type(*i);
        break;
      }
    }
  else
    {
      first_scope = a.back();
      interned_string scope_name, cur_scope_name = first_scope->get_name();
      for (scope_decl::scopes::const_iterator i =
         scope->get_member_scopes().begin();
       i != scope->get_member_scopes().end();
       ++i)
    {
      scope_name = (*i)->get_name();
      if (scope_name == cur_scope_name)
        {
          result = lookup_type_in_scope(type, a, (*i).get());
          break;
        }
    }
    }
  return result;
}

/// lookup a type in a scope.
///
/// This is really slow as it walks the member types of the scope in
/// sequence to find the type with a given name.
///
/// If possible, users should prefer looking up types from the
/// enclosing translation unit or even ABI corpus because both the
/// translation unit and the corpus have a map of type, indexed by
/// their name.  Looking up a type from those maps is thus much
/// faster.
///
/// @param type the type to look for.
///
/// @param scope the top-most scope into which to look for @p type.
///
/// @return the scope found in @p scope, or NULL if it wasn't found.
static const type_base_sptr
lookup_type_in_scope(const type_base_sptr type,
             const scope_decl* scope)
{
  if (!type || is_function_type(type))
    return type_base_sptr();

  decl_base_sptr type_decl = get_type_declaration(type);
  ABG_ASSERT(type_decl);
  vector<scope_decl*> access_path;
  for (scope_decl* s = type_decl->get_scope(); s != 0; s = s->get_scope())
    {
      access_path.push_back(s);
      if (is_global_scope(s))
    break;
    }
  return lookup_type_in_scope(*type, access_path, scope);
}

/// Lookup a type from a translation unit by walking the scopes of the
/// translation unit in sequence and looking into them.
///
/// This is really slow as it walks the member types of the scopes in
/// sequence to find the type with a given name.
///
/// If possible, users should prefer looking up types from the
/// translation unit or even ABI corpus in a more direct way, by using
/// the lookup_type() functins.
///
///
/// This is because both the translation unit and the corpus have a
/// map of types, indexed by their name.  Looking up a type from those
/// maps is thus much faster.  @param fqn the components of the fully
/// qualified name of the node to look up.
///
/// @param tu the translation unit to perform lookup from.
///
/// @return the declaration of the IR node found, NULL otherwise.
const type_base_sptr
lookup_type_through_scopes(const type_base_sptr type,
               const translation_unit& tu)
{
  if (function_type_sptr fn_type = is_function_type(type))
    return lookup_function_type(fn_type, tu);
  return lookup_type_in_scope(type, tu.get_global_scope().get());
}

/// lookup a var_decl in a scope.
///
/// @param comps the components of the fully qualified name of the
/// var_decl to lookup.
///
/// @param skope the scope to look into.
const decl_base_sptr
lookup_var_decl_in_scope(const std::list<string>& comps,
             const scope_decl_sptr& skope)
{return is_var_decl(lookup_node_in_scope<var_decl>(comps, skope));}

/// Lookup an IR node from a translation unit.
///
/// @tparam NodeKind the type of the IR node to lookup from the
/// translation unit.
///
/// @param fqn the components of the fully qualified name of the node
/// to look up.
///
/// @param tu the translation unit to perform lookup from.
///
/// @return the declaration of the IR node found, NULL otherwise.
template<typename NodeKind>
static const type_or_decl_base_sptr
lookup_node_in_translation_unit(const list<string>& fqn,
                const translation_unit& tu)
{return lookup_node_in_scope<NodeKind>(fqn, tu.get_global_scope());}

/// Lookup a type from a translation unit by walking its scopes in
/// sequence and by looking into them.
///
/// This is much slower than using the lookup_type() function.
///
/// @param fqn the components of the fully qualified name of the node
/// to look up.
///
/// @param tu the translation unit to perform lookup from.
///
/// @return the declaration of the IR node found, NULL otherwise.
type_base_sptr
lookup_type_through_scopes(const list<string>& fqn,
               const translation_unit& tu)
{return is_type(lookup_node_in_translation_unit<type_base>(fqn, tu));}


/// Lookup a class type from a translation unit by walking its scopes
/// in sequence and by looking into them.
///
/// This is much slower than using the lookup_class_type() function
/// because it walks all the scopes of the translation unit in
/// sequence and lookup the types to find one that has a given name.
///
/// @param fqn the components of the fully qualified name of the class
/// type node to look up.
///
/// @param tu the translation unit to perform lookup from.
///
/// @return the declaration of the class type IR node found, NULL
/// otherwise.
class_decl_sptr
lookup_class_type_through_scopes(const list<string>& fqn,
                 const translation_unit& tu)
{return is_class_type(lookup_node_in_translation_unit<class_decl>(fqn, tu));}

/// Lookup a basic type from all the translation units of a given
/// corpus.
///
/// @param fqn the components of the fully qualified name of the basic
/// type node to look up.
///
/// @param tu the translation unit to perform lookup from.
///
/// @return the declaration of the basic type IR node found, NULL
/// otherwise.
static type_decl_sptr
lookup_basic_type_through_translation_units(const interned_string& type_name,
                        const corpus& abi_corpus)
{
  type_decl_sptr result;

  for (translation_units::const_iterator tu =
     abi_corpus.get_translation_units().begin();
       tu != abi_corpus.get_translation_units().end();
       ++tu)
    if ((result = lookup_basic_type(type_name, **tu)))
      break;

  return result;
}

/// Lookup a union type from all the translation units of a given
/// corpus.
///
/// @param fqn the components of the fully qualified name of the union
/// type node to look up.
///
/// @param tu the translation unit to perform lookup from.
///
/// @return the declaration of the union type IR node found, NULL
/// otherwise.
static union_decl_sptr
lookup_union_type_through_translation_units(const interned_string& type_name,
                        const corpus & abi_corpus)
{
 union_decl_sptr result;

  for (translation_units::const_iterator tu =
     abi_corpus.get_translation_units().begin();
       tu != abi_corpus.get_translation_units().end();
       ++tu)
    if ((result = lookup_union_type(type_name, **tu)))
      break;

  return result;
}

/// Lookup an enum type from all the translation units of a given
/// corpus.
///
/// @param fqn the components of the fully qualified name of the enum
/// type node to look up.
///
/// @param tu the translation unit to perform lookup from.
///
/// @return the declaration of the enum type IR node found, NULL
/// otherwise.
static enum_type_decl_sptr
lookup_enum_type_through_translation_units(const interned_string& type_name,
                       const corpus & abi_corpus)
{
  enum_type_decl_sptr result;

  for (translation_units::const_iterator tu =
     abi_corpus.get_translation_units().begin();
       tu != abi_corpus.get_translation_units().end();
       ++tu)
    if ((result = lookup_enum_type(type_name, **tu)))
      break;

  return result;
}

/// Lookup a typedef type definition in all the translation units of a
/// given ABI corpus.
///
/// @param @param qn the fully qualified name of the typedef type to lookup.
///
/// @param abi_corpus the ABI corpus which to look the type up in.
///
/// @return the type definition if any was found, or a NULL pointer.
static typedef_decl_sptr
lookup_typedef_type_through_translation_units(const interned_string& type_name,
                          const corpus & abi_corpus)
{
  typedef_decl_sptr result;

  for (translation_units::const_iterator tu =
     abi_corpus.get_translation_units().begin();
       tu != abi_corpus.get_translation_units().end();
       ++tu)
    if ((result = lookup_typedef_type(type_name, **tu)))
      break;

  return result;
}

/// Lookup a qualified type definition in all the translation units of a
/// given ABI corpus.
///
/// @param @param qn the fully qualified name of the qualified type to
/// lookup.
///
/// @param abi_corpus the ABI corpus which to look the type up in.
///
/// @return the type definition if any was found, or a NULL pointer.
static qualified_type_def_sptr
lookup_qualified_type_through_translation_units(const interned_string& t_name,
                        const corpus & abi_corpus)
{
  qualified_type_def_sptr result;

  for (translation_units::const_iterator tu =
     abi_corpus.get_translation_units().begin();
       tu != abi_corpus.get_translation_units().end();
       ++tu)
    if ((result = lookup_qualified_type(t_name, **tu)))
      break;

  return result;
}

/// Lookup a pointer type definition in all the translation units of a
/// given ABI corpus.
///
/// @param @param qn the fully qualified name of the pointer type to
/// lookup.
///
/// @param abi_corpus the ABI corpus which to look the type up in.
///
/// @return the type definition if any was found, or a NULL pointer.
static pointer_type_def_sptr
lookup_pointer_type_through_translation_units(const interned_string& type_name,
                          const corpus & abi_corpus)
{
  pointer_type_def_sptr result;

  for (translation_units::const_iterator tu =
     abi_corpus.get_translation_units().begin();
       tu != abi_corpus.get_translation_units().end();
       ++tu)
    if ((result = lookup_pointer_type(type_name, **tu)))
      break;

  return result;
}

/// Lookup a reference type definition in all the translation units of a
/// given ABI corpus.
///
/// @param @param qn the fully qualified name of the reference type to
/// lookup.
///
/// @param abi_corpus the ABI corpus which to look the type up in.
///
/// @return the type definition if any was found, or a NULL pointer.
static reference_type_def_sptr
lookup_reference_type_through_translation_units(const interned_string& t_name,
                        const corpus & abi_corpus)
{
  reference_type_def_sptr result;

  for (translation_units::const_iterator tu =
     abi_corpus.get_translation_units().begin();
       tu != abi_corpus.get_translation_units().end();
       ++tu)
    if ((result = lookup_reference_type(t_name, **tu)))
      break;

  return result;
}

/// Lookup a array type definition in all the translation units of a
/// given ABI corpus.
///
/// @param @param qn the fully qualified name of the array type to
/// lookup.
///
/// @param abi_corpus the ABI corpus which to look the type up in.
///
/// @return the type definition if any was found, or a NULL pointer.
static array_type_def_sptr
lookup_array_type_through_translation_units(const interned_string& type_name,
                        const corpus & abi_corpus)
{
  array_type_def_sptr result;

  for (translation_units::const_iterator tu =
     abi_corpus.get_translation_units().begin();
       tu != abi_corpus.get_translation_units().end();
       ++tu)
    if ((result = lookup_array_type(type_name, **tu)))
      break;

  return result;
}

/// Lookup a function type definition in all the translation units of
/// a given ABI corpus.
///
/// @param @param qn the fully qualified name of the function type to
/// lookup.
///
/// @param abi_corpus the ABI corpus which to look the type up in.
///
/// @return the type definition if any was found, or a NULL pointer.
static function_type_sptr
lookup_function_type_through_translation_units(const interned_string& type_name,
                           const corpus & abi_corpus)
{
  function_type_sptr result;

  for (translation_units::const_iterator tu =
     abi_corpus.get_translation_units().begin();
       tu != abi_corpus.get_translation_units().end();
       ++tu)
    if ((result = lookup_function_type(type_name, **tu)))
      break;

  return result;
}

/// Lookup a type definition in all the translation units of a given
/// ABI corpus.
///
/// @param @param qn the fully qualified name of the type to lookup.
///
/// @param abi_corpus the ABI corpus which to look the type up in.
///
/// @return the type definition if any was found, or a NULL pointer.
type_base_sptr
lookup_type_through_translation_units(const string& qn,
                      const corpus& abi_corpus)
{
  type_base_sptr result;

  for (translation_units::const_iterator tu =
     abi_corpus.get_translation_units().begin();
       tu != abi_corpus.get_translation_units().end();
       ++tu)
    if ((result = lookup_type(qn, **tu)))
      break;

  return result;
}

/// Lookup a type from a given translation unit present in a give corpus.
///
/// @param type_name the name of the type to look for.
///
/// @parm tu_path the path of the translation unit to consider.
///
/// @param corp the corpus to consider.
///
/// @return the resulting type, if any.
type_base_sptr
lookup_type_from_translation_unit(const string& type_name,
                  const string& tu_path,
                  const corpus& corp)
{
  string_tu_map_type::const_iterator i =  corp.priv_->path_tu_map.find(tu_path);
  if (i == corp.priv_->path_tu_map.end())
    return type_base_sptr();

  translation_unit_sptr tu = i->second;
  ABG_ASSERT(tu);

  type_base_sptr t = lookup_type(type_name, *tu);
  return t;
}

/// Look into an ABI corpus for a function type.
///
/// @param fn_type the function type to be looked for in the ABI
/// corpus.
///
/// @param corpus the ABI corpus into which to look for the function
/// type.
///
/// @return the function type found in the corpus.
function_type_sptr
lookup_or_synthesize_fn_type(const function_type_sptr& fn_t,
                 const corpus& corpus)
{
  ABG_ASSERT(fn_t);

  function_type_sptr result;

  if ((result = lookup_function_type(fn_t, corpus)))
    return result;

  for (translation_units::const_iterator i =
     corpus.get_translation_units().begin();
       i != corpus.get_translation_units().end();
       ++i)
    if ((result = synthesize_function_type_from_translation_unit(*fn_t,
                                 **i)))
      return result;

  return result;
}

/// Look into a given corpus to find a type which has the same
/// qualified name as a giventype.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param t the type which has the same qualified name as the type we
/// are looking for.
///
/// @param corp the ABI corpus to look into for the type.
type_decl_sptr
lookup_basic_type(const type_decl& t, const corpus& corp)
{return lookup_basic_type(t.get_name(), corp);}

/// Look into a given corpus to find a basic type which has a given
/// qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the basic type to look
/// for.
///
/// @param corp the corpus to look into.
type_decl_sptr
lookup_basic_type(const interned_string &qualified_name, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m = corp.get_types().basic_types();
  type_decl_sptr result;

  if (!m.empty())
    result = lookup_type_in_map<type_decl>(qualified_name, m);
  else
    result = lookup_basic_type_through_translation_units(qualified_name, corp);

  return result;
}

/// Lookup a @ref type_decl type from a given corpus, by its location.
///
/// @param loc the location to consider.
///
/// @param corp the corpus to consider.
///
/// @return the resulting basic type, if any.
type_decl_sptr
lookup_basic_type_per_location(const interned_string &loc,
                   const corpus &corp)
{
  const istring_type_base_wptrs_map_type& m =
    corp.get_type_per_loc_map().basic_types();
  type_decl_sptr result;

  result = lookup_type_in_map<type_decl>(loc, m);

  return result;
}

/// Lookup a @ref type_decl type from a given corpus, by its location.
///
/// @param loc the location to consider.
///
/// @param corp the corpus to consider.
///
/// @return the resulting basic type, if any.
type_decl_sptr
lookup_basic_type_per_location(const string &loc, const corpus &corp)
{
  const environment& env = corp.get_environment();
  return lookup_basic_type_per_location(env.intern(loc), corp);
}

/// Look into a given corpus to find a basic type which has a given
/// qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the basic type to look
/// for.
///
/// @param corp the corpus to look into.
type_decl_sptr
lookup_basic_type(const string& qualified_name, const corpus& corp)
{
  return lookup_basic_type(corp.get_environment().intern(qualified_name),
               corp);
}

/// Look into a given corpus to find a class type which has the same
/// qualified name as a given type.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param t the class decl type which has the same qualified name as
/// the type we are looking for.
///
/// @param corp the corpus to look into.
class_decl_sptr
lookup_class_type(const class_decl& t, const corpus& corp)
{
  interned_string s = get_type_name(t);
  return lookup_class_type(s, corp);
}

/// Look into a given corpus to find a class type which has a given
/// qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the type to look for.
///
/// @param corp the corpus to look into.
class_decl_sptr
lookup_class_type(const string& qualified_name, const corpus& corp)
{
  interned_string s = corp.get_environment().intern(qualified_name);
  return lookup_class_type(s, corp);
}

/// Look into a given corpus to find a class type which has a given
/// qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the type to look for.
///
/// @param corp the corpus to look into.
class_decl_sptr
lookup_class_type(const interned_string& qualified_name, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m = corp.get_types().class_types();

  class_decl_sptr result = lookup_type_in_map<class_decl>(qualified_name, m);

  return result;
}

/// Look into a given corpus to find the class type*s* that have a
/// given qualified name.
///
/// @param qualified_name the qualified name of the type to look for.
///
/// @param corp the corpus to look into.
///
/// @return the vector of class types named @p qualified_name.
const type_base_wptrs_type *
lookup_class_types(const interned_string& qualified_name, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m = corp.get_types().class_types();

  return lookup_types_in_map(qualified_name, m);
}

/// Look into a given corpus to find the class type*s* that have a
/// given qualified name and that are declaration-only.
///
/// @param qualified_name the qualified name of the type to look for.
///
/// @param corp the corpus to look into.
///
/// @param result the vector of decl-only class types named @p
/// qualified_name.  This is populated iff the function returns true.
///
/// @return true iff @p result was populated with the decl-only
/// classes named @p qualified_name.
bool
lookup_decl_only_class_types(const interned_string& qualified_name,
                 const corpus& corp,
                 type_base_wptrs_type& result)
{
  const istring_type_base_wptrs_map_type& m = corp.get_types().class_types();

  const type_base_wptrs_type *v = lookup_types_in_map(qualified_name, m);
  if (!v)
    return false;

  for (auto type : *v)
    {
      type_base_sptr t(type);
      class_decl_sptr c = is_class_type(t);
      if (c->get_is_declaration_only()
      && !c->get_definition_of_declaration())
    result.push_back(type);
    }

  return !result.empty();
}

/// Look into a given corpus to find the union type*s* that have a
/// given qualified name.
///
/// @param qualified_name the qualified name of the type to look for.
///
/// @param corp the corpus to look into.
///
/// @return the vector of union types named @p qualified_name.
const type_base_wptrs_type *
lookup_union_types(const interned_string& qualified_name, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m = corp.get_types().union_types();

  return lookup_types_in_map(qualified_name, m);
}

/// Look into a given corpus to find the class type*s* that have a
/// given qualified name.
///
/// @param qualified_name the qualified name of the type to look for.
///
/// @param corp the corpus to look into.
///
/// @return the vector of class types which name is @p qualified_name.
const type_base_wptrs_type*
lookup_class_types(const string& qualified_name, const corpus& corp)
{
  interned_string s = corp.get_environment().intern(qualified_name);
  return lookup_class_types(s, corp);
}

/// Look into a given corpus to find the union types that have a given
/// qualified name.
///
/// @param qualified_name the qualified name of the type to look for.
///
/// @param corp the corpus to look into.
///
/// @return the vector of union types which name is @p qualified_name.
const type_base_wptrs_type *
lookup_union_types(const string& qualified_name, const corpus& corp)
{
  interned_string s = corp.get_environment().intern(qualified_name);
  return lookup_union_types(s, corp);
}

/// Look up a @ref class_decl from a given corpus by its location.
///
/// @param loc the location to consider.
///
/// @param corp the corpus to consider.
///
/// @return the resulting class decl, if any.
class_decl_sptr
lookup_class_type_per_location(const interned_string& loc,
                   const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m =
    corp.get_type_per_loc_map().class_types();
  class_decl_sptr result = lookup_type_in_map<class_decl>(loc, m);

  return result;
}

/// Look up a @ref class_decl from a given corpus by its location.
///
/// @param loc the location to consider.
///
/// @param corp the corpus to consider.
///
/// @return the resulting class decl, if any.
class_decl_sptr
lookup_class_type_per_location(const string &loc, const corpus &corp)
{
  const environment& env = corp.get_environment();
  return lookup_class_type_per_location(env.intern(loc), corp);
}

/// Look into a given corpus to find a union type which has a given
/// qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the type to look for.
///
/// @param corp the corpus to look into.
union_decl_sptr
lookup_union_type(const interned_string& type_name, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m = corp.get_types().union_types();

  union_decl_sptr result = lookup_type_in_map<union_decl>(type_name, m);
  if (!result)
    result = lookup_union_type_through_translation_units(type_name, corp);

  return result;
}

/// Look into a given corpus to find a union type which has a given
/// qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the type to look for.
///
/// @param corp the corpus to look into.
union_decl_sptr
lookup_union_type(const string& type_name, const corpus& corp)
{
  interned_string s = corp.get_environment().intern(type_name);
  return lookup_union_type(s, corp);
}

/// Look into a given corpus to find an enum type which has the same
/// qualified name as a given enum type.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param t the enum type which has the same qualified name as the
/// type we are looking for.
///
/// @param corp the corpus to look into.
enum_type_decl_sptr
lookup_enum_type(const enum_type_decl& t, const corpus& corp)
{
  interned_string s = get_type_name(t);
  return lookup_enum_type(s, corp);
}

/// Look into a given corpus to find an enum type which has a given
/// qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the enum type to look
/// for.
///
/// @param corp the corpus to look into.
enum_type_decl_sptr
lookup_enum_type(const string& qualified_name, const corpus& corp)
{
  interned_string s = corp.get_environment().intern(qualified_name);
  return lookup_enum_type(s, corp);
}

/// Look into a given corpus to find an enum type which has a given
/// qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the enum type to look
/// for.
///
/// @param corp the corpus to look into.
enum_type_decl_sptr
lookup_enum_type(const interned_string& qualified_name, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m = corp.get_types().enum_types();

  enum_type_decl_sptr result =
    lookup_type_in_map<enum_type_decl>(qualified_name, m);
  if (!result)
    result = lookup_enum_type_through_translation_units(qualified_name, corp);

  return result;
}

/// Look into a given corpus to find the enum type*s* that have a
/// given qualified name.
///
/// @param qualified_name the qualified name of the type to look for.
///
/// @param corp the corpus to look into.
///
/// @return the vector of enum types that which name is @p qualified_name.
const type_base_wptrs_type *
lookup_enum_types(const interned_string& qualified_name, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m = corp.get_types().enum_types();

  return lookup_types_in_map(qualified_name, m);
}

/// Look into a given corpus to find the enum type*s* that have a
/// given qualified name.
///
/// @param qualified_name the qualified name of the type to look for.
///
/// @param corp the corpus to look into.
///
/// @return the vector of enum types that which name is @p qualified_name.
const type_base_wptrs_type*
lookup_enum_types(const string& qualified_name, const corpus& corp)
{
  interned_string s = corp.get_environment().intern(qualified_name);
  return lookup_enum_types(s, corp);
}

/// Look up an @ref enum_type_decl from a given corpus, by its location.
///
/// @param loc the location to consider.
///
/// @param corp the corpus to look the type from.
///
/// @return the resulting enum type, if any.
enum_type_decl_sptr
lookup_enum_type_per_location(const interned_string &loc, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m =
    corp.get_type_per_loc_map().enum_types();
  enum_type_decl_sptr result = lookup_type_in_map<enum_type_decl>(loc, m);

  return result;
}

/// Look up an @ref enum_type_decl from a given corpus, by its location.
///
/// @param loc the location to consider.
///
/// @param corp the corpus to look the type from.
///
/// @return the resulting enum type, if any.
enum_type_decl_sptr
lookup_enum_type_per_location(const string &loc, const corpus &corp)
{
  const environment& env = corp.get_environment();
  return lookup_enum_type_per_location(env.intern(loc), corp);
}

/// Look into a given corpus to find a typedef type which has the
/// same qualified name as a given typedef type.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param t the typedef type which has the same qualified name as the
/// typedef type we are looking for.
///
/// @param corp the corpus to look into.
typedef_decl_sptr
lookup_typedef_type(const typedef_decl& t, const corpus& corp)
{
  interned_string s = get_type_name(t);
  return lookup_typedef_type(s, corp);
}

/// Look into a given corpus to find a typedef type which has the
/// same qualified name as a given typedef type.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param t the typedef type which has the same qualified name as the
/// typedef type we are looking for.
///
/// @param corp the corpus to look into.
typedef_decl_sptr
lookup_typedef_type(const string& qualified_name, const corpus& corp)
{
  interned_string s = corp.get_environment().intern(qualified_name);
  return lookup_typedef_type(s, corp);
}

/// Look into a given corpus to find a typedef type which has a
/// given qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the typedef type to
/// look for.
///
/// @param corp the corpus to look into.
typedef_decl_sptr
lookup_typedef_type(const interned_string& qualified_name, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m = corp.get_types().typedef_types();

  typedef_decl_sptr result =
    lookup_type_in_map<typedef_decl>(qualified_name, m);
  if (!result)
    result = lookup_typedef_type_through_translation_units(qualified_name,
                               corp);

  return result;
}

/// Lookup a @ref typedef_decl from a corpus, by its location.
///
/// @param loc the location to consider.
///
/// @param corp the corpus to consider.
///
/// @return the typedef_decl found, if any.
typedef_decl_sptr
lookup_typedef_type_per_location(const interned_string &loc, const corpus &corp)
{
  const istring_type_base_wptrs_map_type& m =
    corp.get_type_per_loc_map().typedef_types();
  typedef_decl_sptr result = lookup_type_in_map<typedef_decl>(loc, m);

  return result;
}

/// Lookup a @ref typedef_decl from a corpus, by its location.
///
/// @param loc the location to consider.
///
/// @param corp the corpus to consider.
///
/// @return the typedef_decl found, if any.
typedef_decl_sptr
lookup_typedef_type_per_location(const string &loc, const corpus &corp)
{
  const environment& env = corp.get_environment();
  return lookup_typedef_type_per_location(env.intern(loc), corp);
}

/// Look into a corpus to find a class, union or typedef type which
/// has a given qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the name of the type to find.
///
/// @param corp the corpus to look into.
///
/// @return the typedef or class type found.
type_base_sptr
lookup_class_or_typedef_type(const string& qualified_name, const corpus& corp)
{
  type_base_sptr result = lookup_class_type(qualified_name, corp);
  if (!result)
    result = lookup_union_type(qualified_name, corp);

  if (!result)
    result = lookup_typedef_type(qualified_name, corp);
  return result;
}

/// Look into a corpus to find a class, typedef or enum type which has
/// a given qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the type to look for.
///
/// @param corp the corpus to look into.
///
/// @return the typedef, class or enum type found.
type_base_sptr
lookup_class_typedef_or_enum_type(const string& qualified_name,
                  const corpus& corp)
{
  type_base_sptr result = lookup_class_or_typedef_type(qualified_name, corp);
  if (!result)
    result = lookup_enum_type(qualified_name, corp);

  return result;
}

/// Look into a given corpus to find a qualified type which has the
/// same qualified name as a given type.
///
/// @param t the type which has the same qualified name as the
/// qualified type we are looking for.
///
/// @param corp the corpus to look into.
///
/// @return the qualified type found.
qualified_type_def_sptr
lookup_qualified_type(const qualified_type_def& t, const corpus& corp)
{
  interned_string s = get_type_name(t);
  return lookup_qualified_type(s, corp);
}

/// Look into a given corpus to find a qualified type which has a
/// given qualified name.
///
/// @param qualified_name the qualified name of the type to look for.
///
/// @param corp the corpus to look into.
///
/// @return the type found.
qualified_type_def_sptr
lookup_qualified_type(const interned_string& qualified_name, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m =
    corp.get_types().qualified_types();

  qualified_type_def_sptr result =
    lookup_type_in_map<qualified_type_def>(qualified_name, m);

  if (!result)
    result = lookup_qualified_type_through_translation_units(qualified_name,
                                 corp);

  return result;
}

/// Look into a given corpus to find a pointer type which has the same
/// qualified name as a given pointer type.
///
/// @param t the pointer type which has the same qualified name as the
/// type we are looking for.
///
/// @param corp the corpus to look into.
///
/// @return the pointer type found.
pointer_type_def_sptr
lookup_pointer_type(const pointer_type_def& t, const corpus& corp)
{
  interned_string s = get_type_name(t);
  return lookup_pointer_type(s, corp);
}

/// Look into a given corpus to find a pointer type which has a given
/// qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the pointer type to
/// look for.
///
/// @param corp the corpus to look into.
///
/// @return the pointer type found.
pointer_type_def_sptr
lookup_pointer_type(const interned_string& qualified_name, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m = corp.get_types().pointer_types();

  pointer_type_def_sptr result =
    lookup_type_in_map<pointer_type_def>(qualified_name, m);
  if (!result)
    result = lookup_pointer_type_through_translation_units(qualified_name,
                               corp);

  return result;
}

/// Look into a given corpus to find a reference type which has the
/// same qualified name as a given reference type.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param t the reference type which has the same qualified name as
/// the reference type we are looking for.
///
/// @param corp the corpus to look into.
///
/// @return the reference type found.
reference_type_def_sptr
lookup_reference_type(const reference_type_def& t, const corpus& corp)
{
  interned_string s = get_type_name(t);
  return lookup_reference_type(s, corp);
}

/// Look into a given corpus to find a reference type which has a
/// given qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the reference type to
/// look for.
///
/// @param corp the corpus to look into.
///
/// @return the reference type found.
reference_type_def_sptr
lookup_reference_type(const interned_string& qualified_name, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m =
    corp.get_types().reference_types();

  reference_type_def_sptr result =
    lookup_type_in_map<reference_type_def>(qualified_name, m);
  if (!result)
    result = lookup_reference_type_through_translation_units(qualified_name,
                                 corp);

  return result;
}

/// Look into a given corpus to find an array type which has a given
/// qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the array type to look
/// for.
///
/// @param corp the corpus to look into.
///
/// @return the array type found.
array_type_def_sptr
lookup_array_type(const array_type_def& t, const corpus& corp)
{
  interned_string s = get_type_name(t);
  return lookup_array_type(s, corp);
}

/// Look into a given corpus to find an array type which has the same
/// qualified name as a given array type.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param t the type which has the same qualified name as the type we
/// are looking for.
///
/// @param corp the corpus to look into.
///
/// @return the type found.
array_type_def_sptr
lookup_array_type(const interned_string& qualified_name, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m = corp.get_types().array_types();

  array_type_def_sptr result =
    lookup_type_in_map<array_type_def>(qualified_name, m);
  if (!result)
    result = lookup_array_type_through_translation_units(qualified_name, corp);

  return result;
}

/// Look into a given corpus to find a function type which has the same
/// qualified name as a given function type.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param t the function type which has the same qualified name as
/// the function type we are looking for.
///
/// @param corp the corpus to look into.
///
/// @return the function type found.
function_type_sptr
lookup_function_type(const function_type&t, const corpus& corp)
{
  interned_string type_name = get_type_name(t);
  return lookup_function_type(type_name, corp);
}

/// Look into a given corpus to find a function type which has the same
/// qualified name as a given function type.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param t the function type which has the same qualified name as
/// the function type we are looking for.
///
/// @param corp the corpus to look into.
///
/// @return the function type found.
function_type_sptr
lookup_function_type(const function_type_sptr& fn_t,
             const corpus& corpus)
{
  if (fn_t)
    return lookup_function_type(*fn_t, corpus);
  return function_type_sptr();
}

/// Look into a given corpus to find a function type which has a given
/// qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the function type to
/// look for.
///
/// @param corp the corpus to look into.
///
/// @return the function type found.
function_type_sptr
lookup_function_type(const interned_string& qualified_name, const corpus& corp)
{
  const istring_type_base_wptrs_map_type& m = corp.get_types().function_types();

  function_type_sptr result =
    lookup_type_in_map<function_type>(qualified_name, m);
  if (!result)
    result = lookup_function_type_through_translation_units(qualified_name,
                                corp);

  return result;
}

/// Look into a given corpus to find a type which has a given
/// qualified name.
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the function type to
/// look for.
///
/// @param corp the corpus to look into.
///
/// @return the function type found.
type_base_sptr
lookup_type(const interned_string& n, const corpus& corp)
{
  type_base_sptr result;

  ((result = lookup_basic_type(n, corp))
   || (result = lookup_class_type(n, corp))
   || (result = lookup_union_type(n, corp))
   || (result = lookup_enum_type(n, corp))
   || (result = lookup_typedef_type(n, corp))
   || (result = lookup_qualified_type(n, corp))
   || (result = lookup_pointer_type(n, corp))
   || (result = lookup_reference_type(n, corp))
   || (result = lookup_array_type(n, corp))
   || (result= lookup_function_type(n, corp)));

  return result;
}

/// Lookup a type from a corpus, by its location.
///
/// @param loc the location to consider.
///
/// @param corp the corpus to look the type from.
///
/// @return the resulting type, if any found.
type_base_sptr
lookup_type_per_location(const interned_string& loc, const corpus& corp)
{
  // TODO: finish this.

  //TODO: when we fully support types indexed by their location, this
  //function should return a vector of types because at each location,
  //there can be several types that are defined (yay, C and C++,
  //*sigh*).

  type_base_sptr result;
  ((result = lookup_basic_type_per_location(loc, corp))
   || (result = lookup_class_type_per_location(loc, corp))
   || (result = lookup_union_type_per_location(loc, corp))
   || (result = lookup_enum_type_per_location(loc, corp))
   || (result = lookup_typedef_type_per_location(loc, corp)));

  return result;
}

/// Look into a given corpus to find a type
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the function type to
/// look for.
///
/// @param corp the corpus to look into.
///
/// @return the function type found.
type_base_sptr
lookup_type(const type_base&t, const corpus& corp)
{
  interned_string n = get_type_name(t);
  return lookup_type(n, corp);
}

/// Look into a given corpus to find a type
///
/// If the per-corpus type map is non-empty (because the corpus allows
/// the One Definition Rule) then the type islooked up in that
/// per-corpus type map.  Otherwise, the type is looked-up in each
/// translation unit.
///
/// @param qualified_name the qualified name of the function type to
/// look for.
///
/// @param corp the corpus to look into.
///
/// @return the function type found.
type_base_sptr
lookup_type(const type_base_sptr&t, const corpus& corp)
{
  if (t)
    return lookup_type(*t, corp);
  return type_base_sptr();
}

/// Update the map that associates a fully qualified name of a given
/// type to that type.
///
///
/// @param type the type we are considering.
///
/// @param types_map the map to update.  It's a map that assciates a
/// fully qualified name of a type to the type itself.
///
/// @param use_type_name_as_key if true, use the name of the type as
/// the key to look it up later.  If false, then use the location of
/// the type as a key to look it up later.
///
/// @return true iff the type was added to the map.
template<typename TypeKind>
bool
maybe_update_types_lookup_map(const shared_ptr<TypeKind>& type,
                  istring_type_base_wptrs_map_type& types_map,
                  bool use_type_name_as_key = true)
{
  interned_string s;

  if (use_type_name_as_key)
    s = get_type_name(type);
  else if (location l = type->get_location())
    {
      string str = l.expand();
      s = type->get_environment().intern(str);
    }

  istring_type_base_wptrs_map_type::iterator i = types_map.find(s);
  bool result = false;

  if (i == types_map.end())
    {
      types_map[s].push_back(type);
      result = true;
    }
  else
    i->second.push_back(type);

  return result;
}

/// This is the specialization for type @ref class_decl of the
/// function template:
///
///    maybe_update_types_lookup_map<T>(scope_decl*,
///                 const shared_ptr<T>&,
///                 istring_type_base_wptrs_map_type&)
///
/// @param class_type the type to consider.
///
/// @param types_map the type map to update.
///
/// @return true iff the type was added to the map.
template<>
bool
maybe_update_types_lookup_map<class_decl>(const class_decl_sptr& class_type,
                      istring_type_base_wptrs_map_type& map,
                      bool use_type_name_as_key)
{
  class_decl_sptr type = class_type;

  bool update_qname_map = true;
  if (type->get_is_declaration_only())
    {
      // Let's try to look through decl-only classes to get their
      // definition.  But if the class doesn't have a definition then
      // we'll keep it.
      if (class_decl_sptr def =
      is_class_type(class_type->get_definition_of_declaration()))
    type = def;
    }

  if (!update_qname_map)
    return false;

  interned_string s;
  if (use_type_name_as_key)
    {
      string qname = type->get_qualified_name();
      s = type->get_environment().intern(qname);
    }
  else if (location l = type->get_location())
    {
      string str = l.expand();
      s = type->get_environment().intern(str);
    }

  bool result = false;
  istring_type_base_wptrs_map_type::iterator i = map.find(s);
  if (i == map.end())
    {
      map[s].push_back(type);
      result = true;
    }
  else
    i->second.push_back(type);

  return result;
}

/// This is the specialization for type @ref function_type of the
/// function template:
///
///    maybe_update_types_lookup_map<T>(scope_decl*,
///                 const shared_ptr<T>&,
///                 istring_type_base_wptrs_map_type&)
///
/// @param scope the scope of the type to consider.
///
/// @param class_type the type to consider.
///
/// @param types_map the type map to update.
///
/// @return true iff the type was added to the map.
template<>
bool
maybe_update_types_lookup_map<function_type>
(const function_type_sptr& type,
 istring_type_base_wptrs_map_type& types_map,
 bool /*use_type_name_as_key*/)
{
  bool result = false;
  interned_string s = get_type_name(type);
  istring_type_base_wptrs_map_type::iterator i = types_map.find(s);
  if (i == types_map.end())
    {
      types_map[s].push_back(type);
      result = true;
    }
  else
    i->second.push_back(type);

  return result;
}

/// Update the map that associates the fully qualified name of a basic
/// type with the type itself.
///
/// The per-translation unit type map is updated if no type with this
/// name was already existing in that map.
///
/// If no type with this name did already exist in the per-corpus type
/// map, then that per-corpus type map is updated. Otherwise, that
/// type is erased from that per-corpus map.
///
/// @param basic_type the basic type to consider.
void
maybe_update_types_lookup_map(const type_decl_sptr& basic_type)
{
  if (translation_unit *tu = basic_type->get_translation_unit())
    maybe_update_types_lookup_map<type_decl>
      (basic_type, tu->get_types().basic_types());

  if (corpus *type_corpus = basic_type->get_corpus())
    {
      maybe_update_types_lookup_map<type_decl>
    (basic_type,
     type_corpus->priv_->get_types().basic_types());

      maybe_update_types_lookup_map<type_decl>
    (basic_type,
     type_corpus->get_type_per_loc_map().basic_types(),
     /*use_type_name_as_key*/false);

      if (corpus *group = type_corpus->get_group())
    {
      maybe_update_types_lookup_map<type_decl>
        (basic_type,
         group->priv_->get_types().basic_types());

      maybe_update_types_lookup_map<type_decl>
        (basic_type,
         group->get_type_per_loc_map().basic_types(),
         /*use_type_name_as_key*/false);
    }
    }

}

/// Update the map that associates the fully qualified name of a class
/// type with the type itself.
///
/// The per-translation unit type map is updated if no type with this
/// name was already existing in that map.
///
/// If no type with this name did already exist in the per-corpus type
/// map, then that per-corpus type map is updated. Otherwise, that
/// type is erased from that per-corpus map.
///
/// @param class_type the class type to consider.
void
maybe_update_types_lookup_map(const class_decl_sptr& class_type)
{
  if (translation_unit *tu = class_type->get_translation_unit())
    maybe_update_types_lookup_map<class_decl>
      (class_type, tu->get_types().class_types());

  if (corpus *type_corpus = class_type->get_corpus())
    {
      maybe_update_types_lookup_map<class_decl>
    (class_type,
     type_corpus->priv_->get_types().class_types());

      maybe_update_types_lookup_map<class_decl>
    (class_type,
     type_corpus->get_type_per_loc_map().class_types(),
     /*use_type_name_as_key*/false);

      if (corpus *group = type_corpus->get_group())
    {
      maybe_update_types_lookup_map<class_decl>
        (class_type,
         group->priv_->get_types().class_types());

      maybe_update_types_lookup_map<class_decl>
        (class_type,
         group->get_type_per_loc_map().class_types(),
         /*use_type_name_as_key*/false);
    }
    }
}

/// Update the map that associates the fully qualified name of a union
/// type with the type itself.
///
/// The per-translation unit type map is updated if no type with this
/// name was already existing in that map.
///
/// If no type with this name did already exist in the per-corpus type
/// map, then that per-corpus type map is updated. Otherwise, that
/// type is erased from that per-corpus map.
///
/// @param union_type the union type to consider.
void
maybe_update_types_lookup_map(const union_decl_sptr& union_type)
{
  if (translation_unit *tu = union_type->get_translation_unit())
    maybe_update_types_lookup_map<union_decl>
      (union_type, tu->get_types().union_types());

  if (corpus *type_corpus = union_type->get_corpus())
    {
      maybe_update_types_lookup_map<union_decl>
    (union_type,
     type_corpus->priv_->get_types().union_types());

      maybe_update_types_lookup_map<union_decl>
    (union_type,
     type_corpus->get_type_per_loc_map().union_types(),
     /*use_type_name_as_key*/false);

      if (corpus *group = type_corpus->get_group())
    {
      maybe_update_types_lookup_map<union_decl>
        (union_type,
         group->priv_->get_types().union_types());

      maybe_update_types_lookup_map<union_decl>
        (union_type,
         group->get_type_per_loc_map().union_types(),
         /*use_type_name_as_key*/false);
    }
    }
}

/// Update the map that associates the fully qualified name of an enum
/// type with the type itself.
///
/// The per-translation unit type map is updated if no type with this
/// name was already existing in that map.
///
/// If no type with this name did already exist in the per-corpus type
/// map, then that per-corpus type map is updated. Otherwise, that
/// type is erased from that per-corpus map.
///
/// @param enum_type the type to consider.
void
maybe_update_types_lookup_map(const enum_type_decl_sptr& enum_type)
{
  if (translation_unit *tu = enum_type->get_translation_unit())
    maybe_update_types_lookup_map<enum_type_decl>
      (enum_type, tu->get_types().enum_types());

  if (corpus *type_corpus = enum_type->get_corpus())
    {
      maybe_update_types_lookup_map<enum_type_decl>
    (enum_type,
     type_corpus->priv_->get_types().enum_types());

      maybe_update_types_lookup_map<enum_type_decl>
    (enum_type,
     type_corpus->get_type_per_loc_map().enum_types(),
     /*use_type_name_as_key*/false);

      if (corpus *group = type_corpus->get_group())
    {
      maybe_update_types_lookup_map<enum_type_decl>
        (enum_type,
         group->priv_->get_types().enum_types());

      maybe_update_types_lookup_map<enum_type_decl>
        (enum_type,
         group->get_type_per_loc_map().enum_types(),
         /*use_type_name_as_key*/false);
    }
    }

}

/// Update the map that associates the fully qualified name of a
/// typedef type with the type itself.
///
/// The per-translation unit type map is updated if no type with this
/// name was already existing in that map.
///
/// If no type with this name did already exist in the per-corpus type
/// map, then that per-corpus type map is updated. Otherwise, that
/// type is erased from that per-corpus map.
///
/// @param typedef_type the type to consider.
void
maybe_update_types_lookup_map(const typedef_decl_sptr& typedef_type)
{
  if (translation_unit *tu = typedef_type->get_translation_unit())
    maybe_update_types_lookup_map<typedef_decl>
      (typedef_type, tu->get_types().typedef_types());

  if (corpus *type_corpus = typedef_type->get_corpus())
    {
      maybe_update_types_lookup_map<typedef_decl>
    (typedef_type,
     type_corpus->priv_->get_types().typedef_types());

      maybe_update_types_lookup_map<typedef_decl>
    (typedef_type,
     type_corpus->get_type_per_loc_map().typedef_types(),
     /*use_type_name_as_key*/false);

      if (corpus *group = type_corpus->get_group())
    {
      maybe_update_types_lookup_map<typedef_decl>
        (typedef_type,
         group->priv_->get_types().typedef_types());

      maybe_update_types_lookup_map<typedef_decl>
        (typedef_type,
         group->get_type_per_loc_map().typedef_types(),
         /*use_type_name_as_key*/false);
    }
    }
}

/// Update the map that associates the fully qualified name of a
/// qualified type with the type itself.
///
/// The per-translation unit type map is updated if no type with this
/// name was already existing in that map.
///
/// If no type with this name did already exist in the per-corpus type
/// map, then that per-corpus type map is updated. Otherwise, that
/// type is erased from that per-corpus map.
///
/// @param qualified_type the type to consider.
void
maybe_update_types_lookup_map(const qualified_type_def_sptr& qualified_type)
{
  if (translation_unit *tu = qualified_type->get_translation_unit())
    maybe_update_types_lookup_map<qualified_type_def>
      (qualified_type, tu->get_types().qualified_types());

  if (corpus *type_corpus = qualified_type->get_corpus())
    {
      maybe_update_types_lookup_map<qualified_type_def>
    (qualified_type,
     type_corpus->priv_->get_types().qualified_types());

      if (corpus *group = type_corpus->get_group())
    {
      maybe_update_types_lookup_map<qualified_type_def>
        (qualified_type,
         group->priv_->get_types().qualified_types());
    }
    }
}

/// Update the map that associates the fully qualified name of a
/// pointer type with the type itself.
///
/// The per-translation unit type map is updated if no type with this
/// name was already existing in that map.
///
/// If no type with this name did already exist in the per-corpus type
/// map, then that per-corpus type map is updated. Otherwise, that
/// type is erased from that per-corpus map.
///
/// @param pointer_type the type to consider.
void
maybe_update_types_lookup_map(const pointer_type_def_sptr& pointer_type)
{
  if (translation_unit *tu = pointer_type->get_translation_unit())
    maybe_update_types_lookup_map<pointer_type_def>
      (pointer_type, tu->get_types().pointer_types());

  if (corpus *type_corpus = pointer_type->get_corpus())
    {
      maybe_update_types_lookup_map<pointer_type_def>
    (pointer_type,
     type_corpus->priv_->get_types().pointer_types());

      if (corpus *group = type_corpus->get_group())
    {
      maybe_update_types_lookup_map<pointer_type_def>
        (pointer_type,
         group->priv_->get_types().pointer_types());
    }
    }
}

/// Update the map that associates the fully qualified name of a
/// pointer-to-member type with the type itself.
///
/// The per-translation unit type map is updated if no type with this
/// name was already existing in that map.
///
/// If no type with this name did already exist in the per-corpus type
/// map, then that per-corpus type map is updated. Otherwise, that
/// type is erased from that per-corpus map.
///
/// @param ptr_to_mbr_type the type to consider.
void
maybe_update_types_lookup_map(const ptr_to_mbr_type_sptr& ptr_to_member)
{
  if (translation_unit *tu = ptr_to_member->get_translation_unit())
    maybe_update_types_lookup_map<ptr_to_mbr_type>
      (ptr_to_member, tu->get_types().ptr_to_mbr_types());

  if (corpus *type_corpus = ptr_to_member->get_corpus())
    {
      maybe_update_types_lookup_map<ptr_to_mbr_type>
    (ptr_to_member,
     type_corpus->priv_->get_types().ptr_to_mbr_types());

      if (corpus *group = type_corpus->get_group())
    {
      maybe_update_types_lookup_map<ptr_to_mbr_type>
        (ptr_to_member,
         group->priv_->get_types().ptr_to_mbr_types());
    }
    }
}

/// Update the map that associates the fully qualified name of a
/// reference type with the type itself.
///
/// The per-translation unit type map is updated if no type with this
/// name was already existing in that map.
///
/// If no type with this name did already exist in the per-corpus type
/// map, then that per-corpus type map is updated. Otherwise, that
/// type is erased from that per-corpus map.
///
/// @param reference_type the type to consider.
void
maybe_update_types_lookup_map(const reference_type_def_sptr& reference_type)
{
  if (translation_unit *tu = reference_type->get_translation_unit())
    maybe_update_types_lookup_map<reference_type_def>
      (reference_type, tu->get_types().reference_types());

  if (corpus *type_corpus = reference_type->get_corpus())
    {
      maybe_update_types_lookup_map<reference_type_def>
    (reference_type,
     type_corpus->priv_->get_types().reference_types());

      if (corpus *group = type_corpus->get_group())
    {
      maybe_update_types_lookup_map<reference_type_def>
        (reference_type,
         group->priv_->get_types().reference_types());
    }
    }
}

/// Update the map that associates the fully qualified name of a type
/// with the type itself.
///
/// The per-translation unit type map is updated if no type with this
/// name was already existing in that map.
///
/// If no type with this name did already exist in the per-corpus type
/// map, then that per-corpus type map is updated. Otherwise, that
/// type is erased from that per-corpus map.
///
/// @param array_type the type to consider.
void
maybe_update_types_lookup_map(const array_type_def_sptr& array_type)
{
  if (translation_unit *tu = array_type->get_translation_unit())
    maybe_update_types_lookup_map<array_type_def>
      (array_type, tu->get_types().array_types());

  if (corpus *type_corpus = array_type->get_corpus())
    {
      maybe_update_types_lookup_map<array_type_def>
    (array_type,
     type_corpus->priv_->get_types().array_types());

      maybe_update_types_lookup_map<array_type_def>
    (array_type,
     type_corpus->get_type_per_loc_map().array_types(),
     /*use_type_name_as_key*/false);

      if (corpus *group = type_corpus->get_group())
    {
      maybe_update_types_lookup_map<array_type_def>
        (array_type,
         group->priv_->get_types().array_types());

      maybe_update_types_lookup_map<array_type_def>
        (array_type,
         group->get_type_per_loc_map().array_types(),
         /*use_type_name_as_key*/false);
    }
    }
}

/// Update the map that associates the fully qualified name of a type
/// with the type itself.
///
/// The per-translation unit type map is updated if no type with this
/// name was already existing in that map.
///
/// If no type with this name did already exist in the per-corpus type
/// map, then that per-corpus type map is updated. Otherwise, that
/// type is erased from that per-corpus map.
///
/// @param subrange_type the type to consider.
void
maybe_update_types_lookup_map
(const array_type_def::subrange_sptr& subrange_type)
{
  if (translation_unit *tu = subrange_type->get_translation_unit())
    maybe_update_types_lookup_map<array_type_def::subrange_type>
      (subrange_type, tu->get_types().subrange_types());

  if (corpus *type_corpus = subrange_type->get_corpus())
    {
      maybe_update_types_lookup_map<array_type_def::subrange_type>
    (subrange_type,
     type_corpus->priv_->get_types().subrange_types());

      maybe_update_types_lookup_map<array_type_def::subrange_type>
    (subrange_type,
     type_corpus->get_type_per_loc_map().subrange_types(),
     /*use_type_name_as_key*/false);

      if (corpus *group = subrange_type->get_corpus())
    {
      maybe_update_types_lookup_map<array_type_def::subrange_type>
        (subrange_type,
         group->priv_->get_types().subrange_types());

      maybe_update_types_lookup_map<array_type_def::subrange_type>
        (subrange_type,
         group->get_type_per_loc_map().subrange_types(),
         /*use_type_name_as_key*/false);
    }
    }
}

/// Update the map that associates the fully qualified name of a
/// function type with the type itself.
///
/// The per-translation unit type map is updated if no type with this
/// name was already existing in that map.
///
/// If no type with this name did already exist in the per-corpus type
/// map, then that per-corpus type map is updated. Otherwise, that
/// type is erased from that per-corpus map.
///
/// @param scope the scope of the function type.
/// @param fn_type the type to consider.
void
maybe_update_types_lookup_map(const function_type_sptr& fn_type)
{
  if (translation_unit *tu = fn_type->get_translation_unit())
    maybe_update_types_lookup_map<function_type>
      (fn_type, tu->get_types().function_types());

  if (corpus *type_corpus = fn_type->get_corpus())
    {
      maybe_update_types_lookup_map<function_type>
    (fn_type,
     type_corpus->priv_->get_types().function_types());

      if (corpus *group = fn_type->get_corpus())
    {
      maybe_update_types_lookup_map<function_type>
        (fn_type,
         group->priv_->get_types().function_types());
    }
    }
}

/// Update the map that associates the fully qualified name of a type
/// declaration with the type itself.
///
/// The per-translation unit type map is updated if no type with this
/// name was already existing in that map.
///
/// If no type with this name did already exist in the per-corpus type
/// map, then that per-corpus type map is updated. Otherwise, that
/// type is erased from that per-corpus map.
///
/// @param decl the declaration of the type to consider.
void
maybe_update_types_lookup_map(const decl_base_sptr& decl)
{
  if (!is_type(decl))
    return;

  if (type_decl_sptr basic_type = is_type_decl(decl))
    maybe_update_types_lookup_map(basic_type);
  else if (class_decl_sptr class_type = is_class_type(decl))
    maybe_update_types_lookup_map(class_type);
  else if (union_decl_sptr union_type = is_union_type(decl))
    maybe_update_types_lookup_map(union_type);
  else if (enum_type_decl_sptr enum_type = is_enum_type(decl))
    maybe_update_types_lookup_map(enum_type);
  else if (typedef_decl_sptr typedef_type = is_typedef(decl))
    maybe_update_types_lookup_map(typedef_type);
  else if (qualified_type_def_sptr qualified_type = is_qualified_type(decl))
    maybe_update_types_lookup_map(qualified_type);
  else if (pointer_type_def_sptr pointer_type = is_pointer_type(decl))
    maybe_update_types_lookup_map(pointer_type);
  else if (ptr_to_mbr_type_sptr ptr_to_member = is_ptr_to_mbr_type(decl))
    maybe_update_types_lookup_map(ptr_to_member);
  else if (reference_type_def_sptr reference_type = is_reference_type(decl))
    maybe_update_types_lookup_map(reference_type);
  else if (array_type_def_sptr array_type = is_array_type(decl))
    maybe_update_types_lookup_map(array_type);
  else if (array_type_def::subrange_sptr subrange_type = is_subrange_type(decl))
    maybe_update_types_lookup_map(subrange_type);
  else if (function_type_sptr fn_type = is_function_type(decl))
    maybe_update_types_lookup_map(fn_type);
  else
    ABG_ASSERT_NOT_REACHED;
}

/// Update the map that associates the fully qualified name of a type
/// with the type itself.
///
/// The per-translation unit type map is updated if no type with this
/// name was already existing in that map.
///
/// If no type with this name did already exist in the per-corpus type
/// map, then that per-corpus type map is updated. Otherwise, that
/// type is erased from that per-corpus map.
///
/// @param type the type to consider.
void
maybe_update_types_lookup_map(const type_base_sptr& type)
{
  if (decl_base_sptr decl = get_type_declaration(type))
    maybe_update_types_lookup_map(decl);
  else if (function_type_sptr fn_type = is_function_type(type))
    maybe_update_types_lookup_map(fn_type);
  else
    ABG_ASSERT_NOT_REACHED;
}

//--------------------------------
// </type and decls lookup stuff>
// ------------------------------

/// In a translation unit, lookup a given type or synthesize it if
/// it's a qualified type.
///
/// So this function first looks the type up in the translation unit.
/// If it's found, then OK, it's returned.  Otherwise, if it's a
/// qualified, reference or pointer or function type (a composite
/// type), lookup the underlying type, synthesize the type we want
/// from it and return it.
///
/// If the underlying types is not not found, then give up and return
/// nil.
///
/// @return the type that was found or the synthesized type.
type_base_sptr
synthesize_type_from_translation_unit(const type_base_sptr& type,
                      translation_unit& tu)
{
  type_base_sptr result;

   result = lookup_type(type, tu);

  if (!result)
    {
      if (qualified_type_def_sptr qual = is_qualified_type(type))
    {
      type_base_sptr underlying_type =
        synthesize_type_from_translation_unit(qual->get_underlying_type(),
                          tu);
      if (underlying_type)
        {
          result.reset(new qualified_type_def(underlying_type,
                          qual->get_cv_quals(),
                          qual->get_location()));
        }
    }
      else if (pointer_type_def_sptr p = is_pointer_type(type))
    {
      type_base_sptr pointed_to_type =
        synthesize_type_from_translation_unit(p->get_pointed_to_type(),
                          tu);
      if (pointed_to_type)
        {
          result.reset(new pointer_type_def(pointed_to_type,
                        p->get_size_in_bits(),
                        p->get_alignment_in_bits(),
                        p->get_location()));
        }
    }
      else if (reference_type_def_sptr r = is_reference_type(type))
    {
      type_base_sptr pointed_to_type =
        synthesize_type_from_translation_unit(r->get_pointed_to_type(), tu);
      if (pointed_to_type)
        {
          result.reset(new reference_type_def(pointed_to_type,
                          r->is_lvalue(),
                          r->get_size_in_bits(),
                          r->get_alignment_in_bits(),
                          r->get_location()));
        }
    }
      else if (function_type_sptr f = is_function_type(type))
    result = synthesize_function_type_from_translation_unit(*f, tu);

      if (result)
    {
      add_decl_to_scope(is_decl(result), tu.get_global_scope());
      canonicalize(result);
    }
    }

  if (result)
    tu.priv_->synthesized_types_.push_back(result);

  return result;
}

/// In a translation unit, lookup the sub-types that make up a given
/// function type and if the sub-types are all found, synthesize and
/// return a function_type with them.
///
/// This function is like lookup_function_type_in_translation_unit()
/// execept that it constructs the function type from the sub-types
/// found in the translation, rather than just looking for the
/// function types held by the translation unit.  This can be useful
/// if the translation unit doesnt hold the function type we are
/// looking for (i.e, lookup_function_type_in_translation_unit()
/// returned NULL) but we still want to see if the sub-types of the
/// function types are present in the translation unit.
///
/// @param fn_type the function type to consider.
///
/// @param tu the translation unit to look into.
///
/// @return the resulting synthesized function type if all its
/// sub-types have been found, NULL otherwise.
function_type_sptr
synthesize_function_type_from_translation_unit(const function_type& fn_type,
                           translation_unit& tu)
{
  function_type_sptr nil = function_type_sptr();

  const environment& env = tu.get_environment();

  type_base_sptr return_type = fn_type.get_return_type();
  type_base_sptr result_return_type;
  if (!return_type || env.is_void_type(return_type))
    result_return_type = env.get_void_type();
  else
    result_return_type = synthesize_type_from_translation_unit(return_type, tu);
  if (!result_return_type)
    return nil;

  function_type::parameters parms;
  type_base_sptr parm_type;
  function_decl::parameter_sptr parm;
  for (function_type::parameters::const_iterator i =
     fn_type.get_parameters().begin();
       i != fn_type.get_parameters().end();
       ++i)
    {
      type_base_sptr t = (*i)->get_type();
      parm_type = synthesize_type_from_translation_unit(t, tu);
      if (!parm_type)
    return nil;
      parm.reset(new function_decl::parameter(parm_type,
                          (*i)->get_index(),
                          (*i)->get_name(),
                          (*i)->get_location(),
                          (*i)->get_variadic_marker(),
                          (*i)->get_is_artificial()));
      parms.push_back(parm);
    }

  class_or_union_sptr class_type;
  const method_type* method = is_method_type(&fn_type);
  if (method)
    {
      class_type = is_class_or_union_type
    (synthesize_type_from_translation_unit(method->get_class_type(), tu));
      ABG_ASSERT(class_type);
    }

  function_type_sptr result_fn_type;

  if (class_type)
    result_fn_type.reset(new method_type(result_return_type,
                     class_type,
                     parms,
                     method->get_is_const(),
                     fn_type.get_size_in_bits(),
                     fn_type.get_alignment_in_bits()));
  else
    result_fn_type.reset(new function_type(result_return_type,
                       parms,
                       fn_type.get_size_in_bits(),
                       fn_type.get_alignment_in_bits()));

  tu.priv_->synthesized_types_.push_back(result_fn_type);
  tu.bind_function_type_life_time(result_fn_type);

  canonicalize(result_fn_type);
  return result_fn_type;
}

/// Demangle a C++ mangled name and return the resulting string
///
/// @param mangled_name the C++ mangled name to demangle.
///
/// @return the resulting mangled name.
string
demangle_cplus_mangled_name(const string& mangled_name)
{
  if (mangled_name.empty())
    return "";

  size_t l = 0;
  int status = 0;
  char * str = abi::__cxa_demangle(mangled_name.c_str(),
                   NULL, &l, &status);
  string demangled_name = mangled_name;
  if (str)
    {
      ABG_ASSERT(status == 0);
      demangled_name = str;
      free(str);
      str = 0;
    }
  return demangled_name;
}

/// Return either the type given in parameter if it's non-null, or the
/// void type.
///
/// @param t the type to consider.
///
/// @param env the environment to use.  If NULL, just abort the
/// process.
///
/// @return either @p t if it is non-null, or the void type.
type_base_sptr
type_or_void(const type_base_sptr t, const environment& env)
{
  type_base_sptr r;

  if (t)
    r = t;
  else
    r = type_base_sptr(env.get_void_type());

  return r;
}

global_scope::~global_scope()
{
}

/// Test if two types are eligible to the "Linux Kernel Fast Type
/// Comparison Optimization", a.k.a LKFTCO.
///
/// Two types T1 and T2 (who are presumably of the same name and kind)
/// are eligible to the LKFTCO if they fulfill the following criteria/
///
/// 1/ T1 and T2 come from the same Linux Kernel Corpus and they are
/// either class, union or enums.
///
/// 2/ They are defined in the same translation unit.
///
/// @param t1 the first type to consider.
///
/// @param t2 the second type to consider.
///
/// @return true iff t1 and t2 are eligible to the LKFTCO.
static bool
types_defined_same_linux_kernel_corpus_public(const type_base& t1,
                          const type_base& t2)
{
  const corpus *t1_corpus = t1.get_corpus(), *t2_corpus = t2.get_corpus();
  string t1_file_path, t2_file_path;

  /// If the t1 (and t2) are classes/unions/enums from the same linux
  /// kernel corpus, let's move on.  Otherwise bail out.
  if (!(t1_corpus && t2_corpus
    && t1_corpus == t2_corpus
    && (t1_corpus->get_origin() & corpus::LINUX_KERNEL_BINARY_ORIGIN)
    && (is_class_or_union_type(&t1)
        || is_enum_type(&t1))))
    return false;

  class_or_union *c1 = 0, *c2 = 0;
  c1 = is_class_or_union_type(&t1);
  c2 = is_class_or_union_type(&t2);

  // Two anonymous class types with no naming typedefs cannot be
  // eligible to this optimization.
  if ((c1 && c1->get_is_anonymous() && !c1->get_naming_typedef())
      || (c2 && c2->get_is_anonymous() && !c2->get_naming_typedef()))
    return false;

  // Two anonymous classes with naming typedefs should have the same
  // typedef name.
  if (c1
      && c2
      && c1->get_is_anonymous() && c1->get_naming_typedef()
      && c2->get_is_anonymous() && c2->get_naming_typedef())
    if (c1->get_naming_typedef()->get_name()
    != c2->get_naming_typedef()->get_name())
      return false;

  // Two anonymous enum types cannot be eligible to this optimization.
  if (const enum_type_decl *e1 = is_enum_type(&t1))
    if (const enum_type_decl *e2 = is_enum_type(&t2))
      if (e1->get_is_anonymous() || e2->get_is_anonymous())
    return false;

  // Look through declaration-only types.  That is, get the associated
  // definition type.
  c1 = look_through_decl_only_class(c1);
  c2 = look_through_decl_only_class(c2);

  if (c1 && c2)
    {
      if (c1->get_is_declaration_only() != c2->get_is_declaration_only())
    {
      if (c1->get_environment().decl_only_class_equals_definition())
        // At least one of classes/union is declaration-only.
        // Because we are in a context in which a declaration-only
        // class/union is equal to all definitions of that
        // class/union, we can assume that the two types are
        // equal.
        return true;
    }
    }

  if (t1.get_size_in_bits() != t2.get_size_in_bits())
    return false;

  // Look at the file names of the locations of t1 and t2.  If they
  // are equal, then t1 and t2 are defined in the same file.
  {
    location l;

    if (c1)
      l = c1->get_location();
    else
      l = dynamic_cast<const decl_base&>(t1).get_location();

    unsigned line = 0, col = 0;
    if (l)
      l.expand(t1_file_path, line, col);
    if (c2)
      l = c2->get_location();
    else
      l = dynamic_cast<const decl_base&>(t2).get_location();
    if (l)
      l.expand(t2_file_path, line, col);
  }

  if (t1_file_path.empty() || t2_file_path.empty())
    return false;

  if (t1_file_path == t2_file_path)
    return true;

  return false;
}


/// Compare a type T against a canonical type.
///
/// This function is called during the canonicalization process of the
/// type T.  T is called the "candidate type" because it's in the
/// process of being canonicalized.  Meaning, it's going to be
/// compared to a canonical type C.  If T equals C, then the canonical
/// type of T is C.
///
/// The purpose of this function is to allow the debugging of the
/// canonicalization of T, if that debugging is activated by
/// configuring the libabigail package with
/// --enable-debug-type-canonicalization and by running "abidw
/// --debug-tc".  In that case, T is going to be compared to C twice:
/// once with canonical equality and once with structural equality.
/// The two comparisons must be equal.  Otherwise, the
/// canonicalization process is said to be faulty and this function
/// aborts.
///
/// This is a sub-routine of type_base::get_canonical_type_for.
///
/// @param canonical_type the canonical type to compare the candidate
/// type against.
///
/// @param candidate_type the candidate type to compare against the
/// canonical type.
///
/// @return true iff @p canonical_type equals @p candidate_type.
///
static bool
compare_types_during_canonicalization(const type_base& canonical_type,
                      const type_base& candidate_type)
{
#ifdef WITH_DEBUG_TYPE_CANONICALIZATION
  const environment& env = canonical_type.get_environment();
  if (env.debug_type_canonicalization_is_on())
    {
      bool canonical_equality = false, structural_equality = false;
      env.priv_->allow_type_comparison_results_caching(false);
      env.priv_->use_canonical_type_comparison_ = false;
      structural_equality = canonical_type == candidate_type;
      env.priv_->use_canonical_type_comparison_ = true;
      canonical_equality = canonical_type == candidate_type;
      env.priv_->allow_type_comparison_results_caching(true);
      if (canonical_equality != structural_equality)
    {
      std::cerr << "structural & canonical equality different for type: "
            << canonical_type.get_pretty_representation(true, true)
            << std::endl;
      ABG_ASSERT_NOT_REACHED;
    }
      return structural_equality;
    }
#endif //end WITH_DEBUG_TYPE_CANONICALIZATION
  return canonical_type == candidate_type;
}

/// Compare a canonical type against a candidate canonical type.
///
/// This is ultimately a sub-routine of the
/// type_base::get_canonical_type_for().
///
/// The goal of this function is to ease debugging because it can be
/// called from within type_base::get_canonical_type_for() from the
/// prompt of the debugger (with some breakpoint appropriately set) to
/// debug the comparison that happens during type canonicalization,
/// between a candidate type being canonicalized, and an existing
/// canonical type that is registered in the system, in as returned by
/// environment::get_canonical_types()
///
/// @param canonical_type the canonical type to consider.
///
/// @param candidate_type the candidate type that is being
/// canonicalized, and thus compared to @p canonical_type.
///
/// @return true iff @p canonical_type compares equal to @p
/// candidate_type.
static bool
compare_canonical_type_against_candidate(const type_base& canonical_type,
                     const type_base& candidate_type)
{
  environment& env = const_cast<environment&>(canonical_type.get_environment());

  // Before the "*it == it" comparison below is done, let's
  // perform on-the-fly-canonicalization.  For C types, let's
  // consider that an unresolved struct declaration 'struct S'
  // is different from a definition 'struct S'.  This is
  // because normally, at this point all the declarations of
  // struct S that are compatible with the definition of
  // struct S have already been resolved to that definition,
  // during the DWARF parsing.  The remaining unresolved
  // declaration are thus considered different.  With this
  // setup we can properly handle cases of two *different*
  // struct S being defined in the same binary (in different
  // translation units), and a third struct S being only
  // declared as an opaque type in a third translation unit of
  // its own, with no definition in there.  In that case, the
  // declaration-only struct S should be left alone and not
  // resolved to any of the two definitions of struct S.
  bool saved_decl_only_class_equals_definition =
    env.decl_only_class_equals_definition();

  // Compare types by considering that decl-only classes don't
  // equal their definition.
  env.decl_only_class_equals_definition(false);
  env.priv_->allow_type_comparison_results_caching(true);
  bool equal = (types_defined_same_linux_kernel_corpus_public(canonical_type,
                                  candidate_type)
        || compare_types_during_canonicalization(canonical_type,
                             candidate_type));
  // Restore the state of the on-the-fly-canonicalization and
  // the decl-only-class-being-equal-to-a-matching-definition
  // flags.
  env.priv_->clear_type_comparison_results_cache();
  env.priv_->allow_type_comparison_results_caching(false);
  env.decl_only_class_equals_definition
    (saved_decl_only_class_equals_definition);
  return equal;
}

/// Compare a canonical type against a candidate canonical type.
///
/// This is ultimately a sub-routine of the
/// type_base::get_canonical_type_for().
///
/// The goal of this function is to ease debugging because it can be
/// called from within type_base::get_canonical_type_for() from the
/// prompt of the debugger (with some breakpoint appropriately set) to
/// debug the comparison that happens during type canonicalization,
/// between a candidate type being canonicalized, and an existing
/// canonical type that is registered in the system, in as returned by
/// environment::get_canonical_types()
///
/// @param canonical_type the canonical type to consider.
///
/// @param candidate_type the candidate type that is being
/// canonicalized, and thus compared to @p canonical_type.
///
/// @return true iff @p canonical_type compares equal to @p
/// candidate_type.
static bool
compare_canonical_type_against_candidate(const type_base* canonical_type,
                     const type_base* candidate_type)
{
  return compare_canonical_type_against_candidate(*canonical_type,
                          *candidate_type);
}

/// Compare a canonical type against a candidate canonical type.
///
/// This is ultimately a sub-routine of the
/// type_base::get_canonical_type_for().
///
/// The goal of this function is to ease debugging because it can be
/// called from within type_base::get_canonical_type_for() from the
/// prompt of the debugger (with some breakpoint appropriately set) to
/// debug the comparison that happens during type canonicalization,
/// between a candidate type being canonicalized, and an existing
/// canonical type that is registered in the system, in as returned by
/// environment::get_canonical_types()
///
/// @param canonical_type the canonical type to consider.
///
/// @param candidate_type the candidate type that is being
/// canonicalized, and thus compared to @p canonical_type.
///
/// @return true iff @p canonical_type compares equal to @p
/// candidate_type.
static bool
compare_canonical_type_against_candidate(const type_base_sptr& canonical_type,
                     const type_base_sptr& candidate_type)
{
  return compare_canonical_type_against_candidate(canonical_type.get(),
                          candidate_type.get());
}

/// Test if a candidate for type canonicalization coming from ABIXML
/// matches a canonical type by first looking at their hash values.
///
/// If the two hash values are equal then the candidate is
/// structurally compared to the canonical type.  If the two hashes
/// are different then the two types are considered different and the
/// function returns nullptr.
///
/// If the candidate doesn't come from ABIXML then the function
/// returns nullptr.
///
/// @param cncls the vector of canonical types to consider.
///
/// @param type the candidate to consider for canonicalization.
///
/// @return the canonical type from @p cncls that matches the
/// candidate @p type.
static type_base_sptr
candidate_matches_a_canonical_type_hash(const vector<type_base_sptr>&   cncls,
                    type_base&          type)
{
  if (type.get_corpus()
      && type.get_corpus()->get_origin() == corpus::NATIVE_XML_ORIGIN
      && peek_hash_value(type))
    {
      // The candidate type comes from ABIXML and does have a stashed
      // hash value coming from the ABIXML.

      // Let's see if we find a potential canonical type whose hash
      // matches the stashed hash and whose canonical type index
      // matches it too.
      for (const auto& c : cncls)
    if (peek_hash_value(type) == peek_hash_value(*c))
      if (get_canonical_type_index(type) == get_canonical_type_index(*c))
        // We found a potential canonical type which hash matches the
        // stashed hash of the candidate type.  Let's compare them to
        // see if they match.
        if (compare_canonical_type_against_candidate(*c, type))
          return c;

      // Let's do the same things, but just consideing hash values.
      for (const auto& c : cncls)
    if (peek_hash_value(type) == peek_hash_value(*c))
      // We found a potential canonical type which hash matches the
      // stashed hash of the candidate type.  Let's compare them to
      // see if they match.
      if (compare_canonical_type_against_candidate(*c, type))
        return c;
    }

  return nullptr;
}

/// Test if we should attempt to compute a hash value for a given
/// type.
///
/// For now this function returns true only for types originating from
/// ELF.  For types originating from ABIXML, for instance, the
/// function return false, meaning that types originating from ABIXML
/// should NOT be hashed.
///
/// @param t the type to consider.
///
/// @return true iff @p type should be considered for hashing.
bool
type_is_suitable_for_hash_computing(const type_base& t)
{
  if (t.get_corpus()
      && (t.get_corpus()->get_origin() & corpus::ELF_ORIGIN))
    return true;
  return false;
}

/// Compute the canonical type for a given instance of @ref type_base.
///
/// Consider two types T and T'.  The canonical type of T, denoted
/// C(T) is a type such as T == T' if and only if C(T) == C(T').  Said
/// otherwise, to compare two types, one just needs to compare their
/// canonical types using pointer equality.  That makes type
/// comparison faster than the structural comparison performed by the
/// abigail::ir::equals() overloads.
///
/// If there is not yet any canonical type for @p t, then @p t is its
/// own canonical type.  Otherwise, this function returns the
/// canonical type of @p t which is the canonical type that has the
/// same hash value as @p t and that structurally equals @p t.  Note
/// that after invoking this function, the life time of the returned
/// canonical time is then equals to the life time of the current
/// process.
///
/// @param t a smart pointer to instance of @ref type_base we want to
/// compute a canonical type for.
///
/// @return the canonical type for the current instance of @ref
/// type_base.
type_base_sptr
type_base::get_canonical_type_for(type_base_sptr t)
{
  if (!t)
    return t;

  environment& env = const_cast<environment&>(t->get_environment());

  if (is_non_canonicalized_type(t))
    // This type should not be canonicalized!
    return type_base_sptr();

  if (is_decl(t))
    t = is_type(look_through_decl_only(is_decl(t)));

  // Look through decl-only types (classes, unions and enums)
  bool decl_only_class_equals_definition =
    (odr_is_relevant(*t) || env.decl_only_class_equals_definition());

  class_or_union_sptr class_or_union = is_class_or_union_type(t);

  // In the context of types from C++ or languages where we assume the
  // "One Definition Rule", we assume that a declaration-only
  // non-anonymous class equals all fully defined classes of the same
  // name.
  //
  // Otherwise, all classes, including declaration-only classes are
  // canonicalized and only canonical comparison is going to be used
  // in the system.
  if (decl_only_class_equals_definition)
    if (class_or_union)
      if (class_or_union->get_is_declaration_only())
    return type_base_sptr();

  class_decl_sptr is_class = is_class_type(t);
  if (t->get_canonical_type())
    return t->get_canonical_type();

  // For classes and union, ensure that an anonymous class doesn't
  // have a linkage name.  If it does in the future, then me must be
  // mindful that the linkage name respects the type identity
  // constraints which states that "if two linkage names are different
  // then the two types are different".
  ABG_ASSERT(!class_or_union
         || !class_or_union->get_is_anonymous()
         || class_or_union->get_linkage_name().empty());

  // We want the pretty representation of the type, but for an
  // internal use, not for a user-facing purpose.
  //
  // If two classe types Foo are declared, one as a class and the
  // other as a struct, but are otherwise equivalent, we want their
  // pretty representation to be the same.  Hence the 'internal'
  // argument of ir::get_pretty_representation() is set to true here.
  // So in this case, the pretty representation of Foo is going to be
  // "class Foo", regardless of its struct-ness. This also applies to
  // composite types which would have "class Foo" as a sub-type.
  string repr = t->get_cached_pretty_representation(/*internal=*/true);

  // If 't' already has a canonical type 'inside' its corpus
  // (t_corpus), then this variable is going to contain that canonical
  // type.
  type_base_sptr canonical_type_present_in_corpus;
  environment::canonical_types_map_type& types =
    env.get_canonical_types_map();

  type_base_sptr result;
  environment::canonical_types_map_type::iterator i = types.find(repr);

  if (i == types.end())
    {
      vector<type_base_sptr> v;
      v.push_back(t);
      types[repr] = v;
      result = t;
    }
  else
    {
      vector<type_base_sptr> &v = i->second;
      // Look at the canonical types and if the current candidate type
      // coming from abixml has the same hash as one of the canonical
      // types, then compare the current candidate with the one with a
      // matching hash.
      result = candidate_matches_a_canonical_type_hash(v, *t);

      // Let's compare 't' structurally (i.e, compare its sub-types
      // recursively) against the canonical types of the system. If it
      // equals a given canonical type C, then it means C is the
      // canonical type of 't'.  Otherwise, if 't' is different from
      // all the canonical types of the system, then it means 't' is a
      // canonical type itself.
      for (vector<type_base_sptr>::const_reverse_iterator it = v.rbegin();
       !result && it != v.rend();
       ++it)
    {
      bool equal = compare_canonical_type_against_candidate(*it, t);
      if (equal)
        {
          result = *it;
          break;
        }
    }
#ifdef WITH_DEBUG_SELF_COMPARISON
      if (env.self_comparison_debug_is_on())
    {
      // So we are debugging the canonicalization process,
      // possibly via the use of 'abidw --debug-abidiff <binary>'.
      corpus_sptr corp1, corp2;
      env.get_self_comparison_debug_inputs(corp1, corp2);
      if (corp1 && corp2 && type_originates_from_corpus(t, corp2)
          && corp1->get_origin() != corp2->get_origin()
          && corp2->get_origin() & corpus::NATIVE_XML_ORIGIN)
        {
          // If 't' comes from the second corpus, then it *must*
          // be equal to its matching canonical type coming from
          // the first corpus because the second corpus is the
          // abixml representation of the first corpus.  In other
          // words, all types coming from the second corpus must
          // have canonical types coming from the first corpus.
          if (result)
        {
          if (!env.priv_->
              check_canonical_type_from_abixml_during_self_comp(t,
                                    result))
            {
              // The canonical type of the type re-read from abixml
              // type doesn't match the canonical type that was
              // initially serialized down.
              uintptr_t should_have_canonical_type = 0;
              string type_id = env.get_type_id_from_type(t.get());
              if (type_id.empty())
            type_id = "type-id-<not-found>";
              else
            should_have_canonical_type =
              env.get_canonical_type_from_type_id(type_id.c_str());
              std::cerr << "error: wrong canonical type for '"
                << repr
                << "' / type: @"
                << std::hex
                << t.get()
                << "/ canon: @"
                << result.get()
                << ", type-id: '"
                << type_id
                << "'.  Should have had canonical type: "
                << std::hex
                << should_have_canonical_type
                << std::dec
                << std::endl;
            }
        }
          else //!result
        {
          uintptr_t ptr_val = reinterpret_cast<uintptr_t>(t.get());
          string type_id = env.get_type_id_from_pointer(ptr_val);
          if (type_id.empty())
            type_id = "type-id-<not-found>";
          // We are in the case where 't' is different from all
          // the canonical types of the same name that come from
          // the first corpus.
          //
          // If 't' indeed comes from the second corpus then this
          // clearly is a canonicalization failure.
          //
          // There was a problem either during the serialization
          // of 't' into abixml, or during the de-serialization
          // from abixml into abigail::ir.  Further debugging is
          // needed to determine what that root cause problem is.
          //
          // Note that the first canonicalization problem of this
          // kind must be fixed before looking at the subsequent
          // ones, because the later might well just be
          // consequences of the former.
          std::cerr << "error: wrong induced canonical type for '"
                << repr
                << "' from second corpus"
                << ", ptr: " << std::hex << t.get()
                << " type-id: " << type_id
                << " /hash="
                << *t->hash_value()
                << std::dec
                << std::endl;
        }
        }
      if (result)
        {
          if (!is_type_decl(t))
          if (hash_t t_hash = peek_hash_value(*t))
            if (hash_t result_hash = peek_hash_value(*result))
              if (t_hash != result_hash)
            {
              std::cerr << "error: type hash mismatch"
                    << " between type: '"
                    << repr
                    << "' @ "
                    << std::hex
                    << t.get()
                    << "/hash="
                    << *t->hash_value()
                    << " and its computed canonical type @"
                    << std::hex
                    << result.get()
                    << "/hash="
                    << std::hex
                    << *result->hash_value()
                    << std::dec
                    << std::endl;
            }
        }
    }
#endif //WITH_DEBUG_SELF_COMPARISON

      if (!result)
    {
      v.push_back(t);
      result = t;
      // we need to generate a canonical type index to sort these
      // types that have the same representation and potentially
      // same hash value but are canonically different.
      t->priv_->canonical_type_index = v.size();
    }
    }

  return result;
}

/// This method is invoked automatically right after the current
/// instance of @ref class_decl has been canonicalized.
void
type_base::on_canonical_type_set()
{}

/// This is a subroutine of the canonicalize() function.
///
/// When the canonical type C of type T has just been computed, there
/// can be cases where T has member functions that C doesn't have.
///
/// This is possible because non virtual member functions are not
/// taken in account when comparing two types.
///
/// In that case, this function updates C so that it contains the
/// member functions.
///
/// There can also be cases where C has a method M which is not linked
/// to any underlying symbol, whereas in T, M is to link to an
/// underlying symbol.  In that case, this function updates M in C so
/// that it's linked to the same underlying symbol as for M in T.
static void
maybe_adjust_canonical_type(const type_base_sptr& canonical,
                const type_base_sptr& type)
{
  if (type->get_naked_canonical_type())
    return;

  class_decl_sptr canonical_class = is_class_type(canonical);

  if (class_decl_sptr cl = is_class_type(type))
    {
      cl = is_class_type(look_through_decl_only_class(cl));
      if (canonical_class
      && canonical_class.get() != cl.get())
    {
      // Set symbols of member functions that might be missing
      // theirs.
      for (class_decl::member_functions::const_iterator i =
         cl->get_member_functions().begin();
           i != cl->get_member_functions().end();
           ++i)
        if ((*i)->get_symbol())
          {
        if (method_decl *m = canonical_class->
            find_member_function((*i)->get_linkage_name()))
          {
            elf_symbol_sptr s1 = (*i)->get_symbol();
            if (s1 && !m->get_symbol())
              // Method 'm' in the canonical type is not
              // linked to the underlying symbol of '*i'.
              // Let's link it now.  have th
              m->set_symbol(s1);
          }
        else
          if (!is_anonymous_type(cl)
              && canonical_class->get_corpus()
              && cl->get_corpus()
              && (cl->get_corpus() == canonical_class->get_corpus()))
            // There is a member function defined and publicly
            // exported in the other class and the canonical
            // class doesn't have that member function.  This
            // should not have happened!  For instance, the
            // DWARF reader does merge the member functions of
            // classes having the same name so that all of them
            // end-up having the same member functions.  What's
            // going on here?
            ABG_ASSERT_NOT_REACHED;
          }

      // Set symbols of static data members that might be missing
      // theirs.
      for (const auto& data_member : cl->get_data_members())
        {
          if (!get_member_is_static(data_member))
        continue;
          elf_symbol_sptr sym = data_member->get_symbol();
          if (!sym)
        continue;
          const auto& canonical_data_member =
        canonical_class->find_data_member(data_member->get_name());
          if (!canonical_data_member)
        {
          // Two classes my be equivalent (same name, non-static
          // sub-objects) and yet not have the same number of
          // static data members, if they are coming from
          // different corpora.  If they are in the same corpus,
          // however then that means there is a problem!
          if (!is_anonymous_type(cl)
              && canonical_class->get_corpus()
              && cl->get_corpus()
              && canonical_class->get_corpus() == cl->get_corpus())
            ABG_ASSERT_NOT_REACHED;

          continue;
        }

          if (!canonical_data_member->get_symbol())
        canonical_data_member->set_symbol(sym);
        }
    }
    }

  // Make sure the virtual member functions with exported symbols are
  // all added to the set of exported functions of the corpus.

  // If we are looking at a non-canonicalized class (for instance, a
  // decl-only class that has virtual member functions), let's pretend
  // it does have a canonical class so that we can perform the
  // necessary virtual  member function adjustments
  if (class_decl_sptr cl = is_class_type(type))
    if (is_non_canonicalized_type(cl))
      {
    ABG_ASSERT(!canonical_class);
    canonical_class = cl;
      }

  if (canonical_class)
    {
      if (auto abi_corpus = canonical_class->get_corpus())
    {
      for (auto& fn : canonical_class->get_member_functions())
        {
          if (elf_symbol_sptr sym = fn->get_symbol())
        {
          if (sym->is_defined() && sym->is_public())
            {
              fn->set_is_in_public_symbol_table(true);
              auto b = abi_corpus->get_exported_decls_builder();
              b->maybe_add_fn_to_exported_fns(fn.get());
            }
          else if (!sym->is_defined())
            abi_corpus->get_undefined_functions().insert(fn.get());
        }
        }
    }
    }

  // If an artificial function type equals a non-artfificial one in
  // the system, then the canonical type of both should be deemed
  // non-artificial.  This is important because only non-artificial
  // canonical function types are emitted out into abixml, so if don't
  // do this we risk missing to emit some function types.
  if (is_function_type(type))
    if (type->get_is_artificial() != canonical->get_is_artificial())
      canonical->set_is_artificial(false);
}

/// Compute the canonical type of a given type.
///
/// It means that after invoking this function, comparing the intance
/// instance @ref type_base and another one (on which
/// type_base::enable_canonical_equality() would have been invoked as
/// well) is performed by just comparing the pointer values of the
/// canonical types of both types.  That equality comparison is
/// supposedly faster than structural comparison of the types.
///
/// @param t a smart pointer to the instance of @ref type_base for
/// which to compute the canonical type.  After this call,
/// t->get_canonical_type() will return the newly computed canonical
/// type.
///
/// @param do_log if true then logs are emitted about canonicalization
/// progress.
///
/// @param show_stats if true and if @p do_log is true as well, then
/// more detailed logs are emitted about canonicalization.
///
/// @return the canonical type computed for @p t.
type_base_sptr
canonicalize(type_base_sptr t, bool do_log, bool show_stats)
{
  if (!t)
    return t;

  if (t->get_canonical_type())
    return t->get_canonical_type();

  if (do_log && show_stats)
    std::cerr << "Canonicalization of type '"
          << t->get_pretty_representation(true, true)
          << "/@#" << std::hex << t.get() << ": ";

  tools_utils::timer tmr;

  if (do_log && show_stats)
    tmr.start();
  type_base_sptr canonical = type_base::get_canonical_type_for(t);

  if (do_log && show_stats)
    tmr.stop();

  if (do_log && show_stats)
    std::cerr << tmr << "\n";

  maybe_adjust_canonical_type(canonical, t);

  t->priv_->canonical_type = canonical;
  t->priv_->naked_canonical_type = canonical.get();

  if (canonical)
    if (!t->priv_->canonical_type_index)
      t->priv_->canonical_type_index = canonical->priv_->canonical_type_index;

  if (class_decl_sptr cl = is_class_type(t))
    if (type_base_sptr d = is_type(cl->get_earlier_declaration()))
      if ((canonical = d->get_canonical_type()))
    {
      d->priv_->canonical_type = canonical;
      d->priv_->naked_canonical_type = canonical.get();
    }

  if (canonical)
    {
      if (decl_base_sptr d = is_decl_slow(canonical))
    {
      scope_decl *scope = d->get_scope();
      // Add the canonical type to the set of canonical types
      // belonging to its scope.
      if (scope)
        {
          if (is_type(scope))
        // The scope in question is itself a type (e.g, a class
        // or union).  Let's call that type ST.  We want to add
        // 'canonical' to the set of canonical types belonging
        // to ST.
        if (type_base_sptr c = is_type(scope)->get_canonical_type())
          // We want to add 'canonical' to the set of
          // canonical types belonging to the canonical type
          // of ST.  That way, just looking at the canonical
          // type of ST is enough to get the types that belong
          // to the scope of the class of equivalence of ST.
          scope = is_scope_decl(is_decl(c)).get();
          scope->get_canonical_types().insert(canonical);
        }
      // else, if the type doesn't have a scope, it's not meant to be
      // emitted.  This can be the case for the result of the
      // function strip_typedef, for instance.
    }
    }

  t->on_canonical_type_set();
  return canonical;
}

/// Set the definition of this declaration-only @ref decl_base.
///
/// @param d the new definition to set.
void
decl_base::set_definition_of_declaration(const decl_base_sptr& d)
{
  ABG_ASSERT(get_is_declaration_only());
  priv_->definition_of_declaration_ = d;
  if (type_base *t = is_type(this))
    if (type_base_sptr canonical_type = is_type(d)->get_canonical_type())
      t->priv_->canonical_type = canonical_type;

  priv_->naked_definition_of_declaration_ = const_cast<decl_base*>(d.get());
}

/// The constructor of @ref type_base.
///
/// @param s the size of the type, in bits.
///
/// @param a the alignment of the type, in bits.
type_base::type_base(const environment& e, size_t s, size_t a)
  : type_or_decl_base(e, ABSTRACT_TYPE_BASE|ABSTRACT_TYPE_BASE),
    priv_(new priv(s, a))
{}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
type_base::hash_value() const
{
  type_base::hash do_hash;
  return do_hash(this);
}

/// Getter of the canonical type of the current instance of @ref
/// type_base.
///
/// @return a smart pointer to the canonical type of the current
/// intance of @ref type_base, or an empty smart pointer if the
/// current instance of @ref type_base doesn't have any canonical
/// type.
type_base_sptr
type_base::get_canonical_type() const
{return priv_->canonical_type.lock();}

/// Getter of the canonical type pointer.
///
/// Note that this function doesn't return a smart pointer, but rather
/// the underlying pointer managed by the smart pointer.  So it's as
/// fast as possible.  This getter is to be used in code paths that
/// are proven to be performance hot spots; especially, when comparing
/// sensitive types like class, function, pointers and reference
/// types.  Those are compared extremely frequently and thus, their
/// accessing the canonical type must be fast.
///
/// @return the canonical type pointer, not managed by a smart
/// pointer.
type_base*
type_base::get_naked_canonical_type() const
{return priv_->naked_canonical_type;}

/// Get the pretty representation of the current type.
///
/// The pretty representation is retrieved from a cache.  If the cache
/// is empty, this function computes the pretty representation, put it
/// in the cache and returns it.
///
/// Please note that if this function is called too early in the life
/// cycle of the type (before the type is fully constructed), then the
/// pretty representation that is cached is going to represent a
/// non-complete (and thus wrong) representation of the type.  Thus
/// this function must be called only once the type is fully
/// constructed.
///
/// @param internal if true, then the pretty representation is to be
/// used for purpuses that are internal to the libabigail library
/// itself.  If you don't know what this means, then you probably
/// should set this parameter to "false".
///
/// @return a reference to a cached @ref interned_string holding the
/// pretty representation of the current type.
const interned_string&
type_base::get_cached_pretty_representation(bool internal) const
{
  if (internal)
    {
      if (priv_->internal_cached_repr_.empty())
    {
      string r = ir::get_pretty_representation(this, internal);
      priv_->internal_cached_repr_ = get_environment().intern(r);
    }
      return priv_->internal_cached_repr_;
    }

  if (priv_->cached_repr_.empty())
    {
      string r = ir::get_pretty_representation(this, internal);
      priv_->cached_repr_ = get_environment().intern(r);
    }

  return priv_->cached_repr_;
}

/// Compares two instances of @ref type_base.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p is non-null and if the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const type_base& l, const type_base& r, change_kind* k)
{
  bool result = (l.get_size_in_bits() == r.get_size_in_bits()
         && l.get_alignment_in_bits() == r.get_alignment_in_bits());
  if (!result)
    if (k)
      *k |= LOCAL_TYPE_CHANGE_KIND;
  ABG_RETURN(result);
}

/// Return true iff both type declarations are equal.
///
/// Note that this doesn't test if the scopes of both types are equal.
bool
type_base::operator==(const type_base& other) const
{return equals(*this, other, 0);}

/// Inequality operator.
///
///@param other the instance of @ref type_base to compare the current
/// instance against.
///
/// @return true iff the current instance is different from @p other.
bool
type_base::operator!=(const type_base& other) const
{return !operator==(other);}

/// Setter for the size of the type.
///
/// @param s the new size -- in bits.
void
type_base::set_size_in_bits(size_t s)
{priv_->size_in_bits = s;}

/// Getter for the size of the type.
///
/// @return the size in bits of the type.
size_t
type_base::get_size_in_bits() const
{return priv_->size_in_bits;}

/// Setter for the alignment of the type.
///
/// @param a the new alignment -- in bits.
void
type_base::set_alignment_in_bits(size_t a)
{priv_->alignment_in_bits = a;}

/// Getter for the alignment of the type.
///
/// @return the alignment of the type in bits.
size_t
type_base::get_alignment_in_bits() const
{return priv_->alignment_in_bits;}

/// Default implementation of traversal for types.  This function does
/// nothing.  It must be implemented by every single new type that is
/// written.
///
/// Please look at e.g, class_decl::traverse() for an example of how
/// to implement this.
///
/// @param v the visitor used to visit the type.
bool
type_base::traverse(ir_node_visitor& v)
{
  if (v.type_node_has_been_visited(this))
    return true;

  v.visit_begin(this);
  bool result = v.visit_end(this);
  v.mark_type_node_as_visited(this);

  return result;
}

type_base::~type_base()
{delete priv_;}

// </type_base definitions>

// <real_type definitions>

/// Bitwise OR operator for real_type::modifiers_type.
///
/// @param l the left-hand side operand.
///
/// @param r the right-hand side operand.
///
/// @return the result of the bitwise OR.
real_type::modifiers_type
operator|(real_type::modifiers_type l, real_type::modifiers_type r)
{
  return static_cast<real_type::modifiers_type>(static_cast<unsigned>(l)
                            |
                            static_cast<unsigned>(r));
}

/// Bitwise AND operator for real_type::modifiers_type.
///
/// @param l the left-hand side operand.
///
/// @param r the right-hand side operand.
///
/// @return the result of the bitwise AND.
real_type::modifiers_type
operator&(real_type::modifiers_type l, real_type::modifiers_type r)
{
  return static_cast<real_type::modifiers_type>(static_cast<unsigned>(l)
                            &
                            static_cast<unsigned>(r));
}

/// Bitwise one's complement operator for real_type::modifiers_type.
///
/// @param l the left-hand side operand.
///
/// @param r the right-hand side operand.
///
/// @return the result of the bitwise one's complement operator.
real_type::modifiers_type
operator~(real_type::modifiers_type l)
{
  return static_cast<real_type::modifiers_type>(~static_cast<unsigned>(l));
}

/// Bitwise |= operator for real_type::modifiers_type.
///
/// @param l the left-hand side operand.
///
/// @param r the right-hand side operand.
///
/// @return the result of the bitwise |=.
real_type::modifiers_type&
operator|=(real_type::modifiers_type& l, real_type::modifiers_type r)
{
  l = l | r;
  return l;
}

/// Bitwise &= operator for real_type::modifiers_type.
///
/// @param l the left-hand side operand.
///
/// @param r the right-hand side operand.
///
/// @return the result of the bitwise &=.
real_type::modifiers_type&
operator&=(real_type::modifiers_type& l, real_type::modifiers_type r)
{
  l = l & r;
  return l;
}

/// Parse a word containing one real type modifier.
///
/// A word is considered to be a string of characters that doesn't
/// contain any white space.
///
/// @param word the word to parse.  It is considered to be a string of
/// characters that doesn't contain any white space.
///
/// @param modifiers out parameter.  It's set by this function to the
/// parsed modifier iff the function returned true.
///
/// @return true iff @word was successfully parsed.
static bool
parse_real_type_modifier(const string& word,
                 real_type::modifiers_type &modifiers)
{
    if (word == "signed")
      modifiers |= real_type::SIGNED_MODIFIER;
    else if (word == "unsigned")
      modifiers |= real_type::UNSIGNED_MODIFIER;
    else if (word == "short")
      modifiers |= real_type::SHORT_MODIFIER;
    else if (word == "long")
      modifiers |= real_type::LONG_MODIFIER;
    else if (word == "long long")
      modifiers |= real_type::LONG_LONG_MODIFIER;
    else
      return false;

    return true;
}

/// Parse a base type of a real type from a string.
///
/// @param type_name the type name to parse.
///
/// @param base out parameter.  This is set to the resulting base type
/// parsed, iff the function returned true.
///
/// @return true iff the function could successfully parse the base
/// type.
static bool
parse_base_real_type(const string& type_name,
             real_type::base_type& base)
{
  if (type_name == "int")
    base = real_type::INT_BASE_TYPE;
  else if (type_name == "char")
    base = real_type::CHAR_BASE_TYPE;
  else if (type_name == "bool" || type_name == "_Bool")
    base = real_type::BOOL_BASE_TYPE;
  else if (type_name == "double")
    base = real_type::DOUBLE_BASE_TYPE;
  else if (type_name =="float")
    base = real_type::FLOAT_BASE_TYPE;
  else if (type_name == "char16_t")
    base = real_type::CHAR16_T_BASE_TYPE;
  else if (type_name == "char32_t")
    base = real_type::CHAR32_T_BASE_TYPE;
  else if (type_name == "wchar_t")
    base = real_type::WCHAR_T_BASE_TYPE;
  else if (type_name == "__ARRAY_SIZE_TYPE__")
    base = real_type::ARRAY_SIZE_BASE_TYPE;
  else if (type_name == "sizetype")
    base = real_type::SIZE_BASE_TYPE;
  else if (type_name == "ssizetype")
    base = real_type::SSIZE_BASE_TYPE;
  else if (type_name == "bitsizetype")
    base = real_type::BIT_SIZE_BASE_TYPE;
  else if (type_name == "sbitsizetype")
    base = real_type::SBIT_SIZE_BASE_TYPE;
  else
    return false;

  return true;
}

/// Parse a real type from a string.
///
/// @param type_name the string containing the real type to parse.
///
/// @param base out parameter.  Is set by this function to the base
/// type of the real type, iff the function returned true.
///
/// @param modifiers out parameter  If set by this function to the
/// modifier of the real type, iff the function returned true.
///
/// @return true iff the function could parse a real type from @p
/// type_name.
static bool
parse_real_type(const string&           type_name,
            real_type::base_type&       base,
            real_type::modifiers_type&  modifiers)
{
  string input = type_name;
  string::size_type len = input.length();
  string::size_type cur_pos = 0, prev_pos = 0;
  string cur_word, prev_word;
  bool ok = false;

  while (cur_pos < len)
    {
      if (cur_pos < len && isspace(input[cur_pos]))
    do
      ++cur_pos;
    while (cur_pos < len && isspace(input[cur_pos]));

      prev_pos = cur_pos;
      cur_pos = input.find(' ', prev_pos);
      prev_word = cur_word;
      cur_word = input.substr(prev_pos, cur_pos - prev_pos);

      if (cur_pos < len
      && cur_word == "long"
      && prev_word != "long")
    {
      if (cur_pos < len && isspace(input[cur_pos]))
        do
          ++cur_pos;
        while (cur_pos < len && isspace(input[cur_pos]));
      prev_pos = cur_pos;

      cur_pos = input.find(' ', prev_pos);
      string saved_prev_word = prev_word;
      prev_word = cur_word;
      cur_word = input.substr(prev_pos, cur_pos - prev_pos);
      if (cur_word == "long")
        cur_word = "long long";
      else
        {
          cur_pos = prev_pos;
          cur_word = prev_word;
          prev_word = saved_prev_word;
        }
    }

      if (!parse_real_type_modifier(cur_word, modifiers))
    {
      if (!parse_base_real_type(cur_word, base))
        return false;
      else
        ok = true;
    }
      else
    ok = true;
    }

  return ok;
}

/// Parse a real type from a string.
///
/// @param str the string containing the real type to parse.
///
///@param type the resulting @ref real_type.  Is set to the result
///of the parse, iff the function returns true.
///
/// @return true iff the function could parse a real type from @p
/// str.
bool
parse_real_type(const string& str, real_type& type)
{
  real_type::base_type base_type = real_type::INT_BASE_TYPE;
  real_type::modifiers_type modifiers = real_type::NO_MODIFIER;

  if (!parse_real_type(str, base_type, modifiers))
    return false;

  // So this is a real type.
  real_type int_type(base_type, modifiers);
  type = int_type;
  return true;
}

/// Default constructor of the @ref real_type.
real_type::real_type()
  : base_(INT_BASE_TYPE),
    modifiers_(NO_MODIFIER)
{}

/// Constructor of the @ref real_type.
///
/// @param b the base type of the real type.
///
/// @param m the modifiers of the real type.
real_type::real_type(base_type b, modifiers_type m)
  : base_(b), modifiers_(m)
{}

/// Constructor of the @ref real_type.
///
/// @param the name of the real type to parse to initialize the
/// current instance of @ref real_type.
real_type::real_type(const string& type_name)
  : base_(INT_BASE_TYPE),
    modifiers_(NO_MODIFIER)
{
  bool could_parse = parse_real_type(type_name, base_, modifiers_);
  ABG_ASSERT(could_parse);
}

/// Getter of the base type of the @ref real_type.
///
/// @return the base type of the @ref real_type.
real_type::base_type
real_type::get_base_type() const
{return base_;}

/// Getter of the modifiers bitmap of the @ref real_type.
///
/// @return the modifiers bitmap of the @ref real_type.
real_type::modifiers_type
real_type::get_modifiers() const
{return modifiers_;}

/// Setter of the modifiers bitmap of the @ref real_type.
///
/// @param m the new modifiers.
void
real_type::set_modifiers(modifiers_type m)
{modifiers_ = m;}

/// Equality operator for the @ref real_type.
///
/// @param other the other real type to compare against.
///
/// @return true iff @p other equals the current instance of @ref
/// real_type.
bool
real_type::operator==(const real_type&other) const
{return base_ == other.base_ && modifiers_ == other.modifiers_;}

/// Return the string representation of the current instance of @ref
/// real_type.
///
/// @param internal if true the string representation is to be used
/// for internal purposes.  In general, it means it's for type
/// canonicalization purposes.
///
/// @return the string representation of the current instance of @ref
/// real_type.
string
real_type::to_string(bool internal) const
{
  string result;

  // Look at modifiers ...
  if (modifiers_ & SIGNED_MODIFIER)
    result += "signed ";
  if (modifiers_ & UNSIGNED_MODIFIER)
    result += "unsigned ";
  if (!internal)
    {
      // For canonicalization purposes, we won't emit the "short, long, or
      // long long" modifiers.  This is because on some platforms, "long
      // int" and "long long int" might have the same size.  In those
      // cases, we want the two types to be equivalent if they have the
      // same size.  If they don't have the same internal string
      // representation, they'd automatically have different canonical
      // types and thus be canonically different.
      if (modifiers_ & SHORT_MODIFIER)
    result += "short ";
      if (modifiers_ & LONG_MODIFIER)
    result += "long ";
      if (modifiers_ & LONG_LONG_MODIFIER)
    result += "long long ";
    }

  // ... and look at base types.
  if (base_ == INT_BASE_TYPE)
    result += "int";
  else if (base_ == CHAR_BASE_TYPE)
    result += "char";
  else if (base_ == BOOL_BASE_TYPE)
    result += "bool";
  else if (base_ == DOUBLE_BASE_TYPE)
    result += "double";
  else if (base_ == FLOAT_BASE_TYPE)
    result += "float";
  else if (base_ == CHAR16_T_BASE_TYPE)
    result += "char16_t";
    else if (base_ == CHAR32_T_BASE_TYPE)
    result += "char32_t";
    else if (base_ == WCHAR_T_BASE_TYPE)
    result += "wchar_t";
    else if (base_ == ARRAY_SIZE_BASE_TYPE)
      result += "__ARRAY_SIZE_TYPE__";
    else if (base_ == SIZE_BASE_TYPE)
      result += "sizetype";
    else if (base_ == SSIZE_BASE_TYPE)
      result += "ssizetype";
    else if (base_ == BIT_SIZE_BASE_TYPE)
      result += "bitsizetype";
    else if (base_ == SBIT_SIZE_BASE_TYPE)
      result += "sbitsizetype";
  return result;
}

/// Convert the current instance of @ref real_type into its string
/// representation.
///
/// @return the string representation of the current instance of @ref
/// real_type.
real_type::operator string() const
{return to_string();}

// </real_type definitions>

//<type_decl definitions>

/// Constructor.
///
/// @param env the environment we are operating from.
///
/// @param name the name of the type declaration.
///
/// @param size_in_bits the size of the current type_decl, in bits.
///
/// @param alignment_in_bits the alignment of the current typ, in
/// bits.
///
/// @param locus the source location of the current type declaration.
///
/// @param linkage_name the linkage_name of the current type declaration.
///
/// @param vis the visibility of the type declaration.
type_decl::type_decl(const environment& env,
             const string&  name,
             size_t     size_in_bits,
             size_t     alignment_in_bits,
             const location&    locus,
             const string&  linkage_name,
             visibility vis)

  : type_or_decl_base(env,
              BASIC_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    decl_base(env, name, locus, linkage_name, vis),
    type_base(env, size_in_bits, alignment_in_bits)
{
  runtime_type_instance(this);

  real_type::base_type base_type = real_type::INT_BASE_TYPE;
  real_type::modifiers_type modifiers = real_type::NO_MODIFIER;
  real_type int_type(base_type, modifiers);
  if (parse_real_type(name, int_type))
    {
      // Convert the real_type into its canonical string
      // representation.
      string real_type_name = int_type;

      // Set the name of this type_decl to the canonical string
      // representation above
      set_name(real_type_name);
      set_qualified_name(get_name());

      if (!get_linkage_name().empty())
    set_linkage_name(real_type_name);
    }
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
type_decl::hash_value() const
{
  hash_t h = set_or_get_cached_hash_value(this);
  return h;
}

/// Compares two instances of @ref type_decl.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const type_decl& l, const type_decl& r, change_kind* k)
{
  bool result = false;

  // Consider the types as decls to compare their decls-related
  // properties.
  result = equals(static_cast<const decl_base&>(l),
          static_cast<const decl_base&>(r),
          k);
  if (!k && !result)
    ABG_RETURN_FALSE;

  // Now consider the types a "types' to compare their size-related
  // properties.
  result &= equals(static_cast<const type_base&>(l),
           static_cast<const type_base&>(r),
           k);
  ABG_RETURN(result);
}

/// Return true if both types equals.
///
/// This operator re-uses the overload that takes a decl_base.
///
/// Note that this does not check the scopes of any of the types.
///
/// @param o the other type_decl to check agains.
bool
type_decl::operator==(const type_base& o) const
{
  const decl_base* other = dynamic_cast<const decl_base*>(&o);
  if (!other)
    return false;
  return *this == *other;
}

/// Return true if both types equals.
///
/// Note that this does not check the scopes of any of the types.
///
/// @param o the other type_decl to check against.
bool
type_decl::operator==(const decl_base& o) const
{
  const type_decl* other = dynamic_cast<const type_decl*>(&o);
  if (!other)
    return false;
  return try_canonical_compare(this, other);
}

/// Return true if both types equals.
///
/// Note that this does not check the scopes of any of the types.
///
/// @param o the other type_decl to check against.
///
/// @return true iff the current isntance equals @p o
bool
type_decl::operator==(const type_decl& o) const
{
  const decl_base& other = o;
  return *this == other;
}

/// Return true if both types equals.
///
/// Note that this does not check the scopes of any of the types.
///
/// @param o the other type_decl to check against.
///
/// @return true iff the current isntance equals @p o
bool
type_decl::operator!=(const type_base&o)const
{return !operator==(o);}

/// Return true if both types equals.
///
/// Note that this does not check the scopes of any of the types.
///
/// @param o the other type_decl to check against.
///
/// @return true iff the current isntance equals @p o
bool
type_decl::operator!=(const decl_base&o)const
{return !operator==(o);}

/// Inequality operator.
///
/// @param o the other type to compare against.
///
/// @return true iff the current instance is different from @p o.
bool
type_decl::operator!=(const type_decl& o) const
{return !operator==(o);}

/// Equality operator for @ref type_decl_sptr.
///
/// @param l the first operand to compare.
///
/// @param r the second operand to compare.
///
/// @return true iff @p l equals @p r.
bool
operator==(const type_decl_sptr& l, const type_decl_sptr& r)
{
  if (!!l != !!r)
    return false;
  if (l.get() == r.get())
    return true;
  return *l == *r;
}

/// Inequality operator for @ref type_decl_sptr.
///
/// @param l the first operand to compare.
///
/// @param r the second operand to compare.
///
/// @return true iff @p l is different from @p r.
bool
operator!=(const type_decl_sptr& l, const type_decl_sptr& r)
{return !operator==(l, r);}

/// Implementation for the virtual qualified name builder for @ref
/// type_decl.
///
/// @param qualified_name the output parameter to hold the resulting
/// qualified name.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
void
type_decl::get_qualified_name(interned_string& qualified_name,
                  bool internal) const
{qualified_name = get_qualified_name(internal);}

/// Implementation for the virtual qualified name builder for @ref
/// type_decl.
///
/// @param qualified_name the output parameter to hold the resulting
/// qualified name.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
const interned_string&
type_decl::get_qualified_name(bool internal) const
{
  const environment& env = get_environment();


  if (internal)
    if (is_real_type(this))
      {
    if (get_naked_canonical_type())
      {
        if (decl_base::priv_->internal_qualified_name_.empty())
          decl_base::priv_->internal_qualified_name_ =
        env.intern(get_internal_real_type_name(this));
        return decl_base::priv_->internal_qualified_name_;
      }
    else
      {
        decl_base::priv_->temporary_internal_qualified_name_ =
          env.intern(get_internal_real_type_name(this));
        return decl_base::priv_->temporary_internal_qualified_name_;
      }
      }

  return decl_base::get_qualified_name(/*internal=*/false);
}

/// Get the pretty representation of the current instance of @ref
/// type_decl.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
///
/// @param qualified_name if true, names emitted in the pretty
/// representation are fully qualified.
///
/// @return the pretty representatin of the @ref type_decl.
string
type_decl::get_pretty_representation(bool internal,
                     bool qualified_name) const
{
  if (internal)
    if (is_real_type(this))
      return get_internal_real_type_name(this);

  if (qualified_name)
    return get_qualified_name(internal);
  return get_name();
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
type_decl::traverse(ir_node_visitor& v)
{
  if (v.type_node_has_been_visited(this))
    return true;

  v.visit_begin(this);
  bool result = v.visit_end(this);
  v.mark_type_node_as_visited(this);

  return result;
}

type_decl::~type_decl()
{}
//</type_decl definitions>

// <scope_type_decl definitions>

/// Constructor.
///
/// @param env the environment we are operating from.
///
/// @param name the name of the type.
///
/// @param size_in_bits the size of the type, in bits.
///
/// @param alignment_in_bits the alignment of the type, in bits.
///
/// @param locus the source location where the type is defined.
///
/// @param vis the visibility of the type.
scope_type_decl::scope_type_decl(const environment& env,
                 const string&      name,
                 size_t     size_in_bits,
                 size_t     alignment_in_bits,
                 const location&    locus,
                 visibility     vis)
  : type_or_decl_base(env,
              ABSTRACT_SCOPE_TYPE_DECL
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    decl_base(env, name, locus, "", vis),
    type_base(env, size_in_bits, alignment_in_bits),
    scope_decl(env, name, locus)
{}

/// Compares two instances of @ref scope_type_decl.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const scope_type_decl& l, const scope_type_decl& r, change_kind* k)
{
  bool result = equals(static_cast<const scope_decl&>(l),
          static_cast<const scope_decl&>(r),
          k);

  if (!k && !result)
    ABG_RETURN_FALSE;

  result &= equals(static_cast<const type_base&>(l),
           static_cast<const type_base&>(r),
           k);

  ABG_RETURN(result);
}

/// Equality operator between two scope_type_decl.
///
/// Note that this function does not consider the scope of the scope
/// types themselves.
///
/// @return true iff both scope types are equal.
bool
scope_type_decl::operator==(const decl_base& o) const
{
  const scope_type_decl* other = dynamic_cast<const scope_type_decl*>(&o);
  if (!other)
    return false;
  return try_canonical_compare(this, other);
}

/// Equality operator between two scope_type_decl.
///
/// This re-uses the equality operator that takes a decl_base.
///
/// @param o the other scope_type_decl to compare against.
///
/// @return true iff both scope types are equal.
bool
scope_type_decl::operator==(const type_base& o) const
{
  const decl_base* other = dynamic_cast<const decl_base*>(&o);
  if (!other)
    return false;

  return *this == *other;
}

/// Traverses an instance of @ref scope_type_decl, visiting all the
/// sub-types and decls that it might contain.
///
/// @param v the visitor that is used to visit every IR sub-node of
/// the current node.
///
/// @return true if either
///  - all the children nodes of the current IR node were traversed
///    and the calling code should keep going with the traversing.
///  - or the current IR node is already being traversed.
/// Otherwise, returning false means that the calling code should not
/// keep traversing the tree.
bool
scope_type_decl::traverse(ir_node_visitor& v)
{
  if (visiting())
    return true;

  if (v.type_node_has_been_visited(this))
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      for (scope_decl::declarations::const_iterator i =
         get_member_decls().begin();
       i != get_member_decls ().end();
       ++i)
    if (!(*i)->traverse(v))
      break;
      visiting(false);
    }

  bool result = v.visit_end(this);
  v.mark_type_node_as_visited(this);

  return result;
}

scope_type_decl::~scope_type_decl()
{}
// </scope_type_decl definitions>

// <namespace_decl>

/// Constructor.
///
/// @param the environment we are operatin from.
///
/// @param name the name of the namespace.
///
/// @param locus the source location where the namespace is defined.
///
/// @param vis the visibility of the namespace.
namespace_decl::namespace_decl(const environment&   env,
                   const string&        name,
                   const location&      locus,
                   visibility       vis)
    // We need to call the constructor of decl_base directly here
    // because it is virtually inherited by scope_decl.  Note that we
    // just implicitely call the default constructor for scope_decl
    // here, as what we really want is to initialize the decl_base
    // subobject.  Wow, virtual inheritance is      useful, but setting it
    // up is ugly.
  : type_or_decl_base(env,
              NAMESPACE_DECL
              | ABSTRACT_DECL_BASE
              | ABSTRACT_SCOPE_DECL),
    decl_base(env, name, locus, "", vis),
    scope_decl(env, name, locus)
{
  runtime_type_instance(this);
}

/// Build and return a copy of the pretty representation of the
/// namespace.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
///
/// @param qualified_name if true, names emitted in the pretty
/// representation are fully qualified.
///
/// @return a copy of the pretty representation of the namespace.
string
namespace_decl::get_pretty_representation(bool internal,
                      bool qualified_name) const
{
  string r =
    "namespace " + scope_decl::get_pretty_representation(internal,
                             qualified_name);
  return r;
}

/// Return true iff both namespaces and their members are equal.
///
/// Note that this function does not check if the scope of these
/// namespaces are equal.
bool
namespace_decl::operator==(const decl_base& o) const
{
  const namespace_decl* other = dynamic_cast<const namespace_decl*>(&o);
  if (!other)
    return false;
  return scope_decl::operator==(*other);
}

/// Test if the current namespace_decl is empty or contains empty
/// namespaces itself.
///
/// @return true iff the current namespace_decl is empty or contains
/// empty itself.
bool
namespace_decl::is_empty_or_has_empty_sub_namespaces() const
{
  if (is_empty())
    return true;

  for (declarations::const_iterator i = get_member_decls().begin();
       i != get_member_decls().end();
       ++i)
    {
      if (!is_namespace(*i))
    return false;

      namespace_decl_sptr ns = is_namespace(*i);
      ABG_ASSERT(ns);

      if (!ns->is_empty_or_has_empty_sub_namespaces())
    return false;
    }

  return true;
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance and on its
/// member nodes.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
namespace_decl::traverse(ir_node_visitor& v)
{
  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      scope_decl::declarations::const_iterator i;
      for (i = get_member_decls().begin();
       i != get_member_decls ().end();
       ++i)
    {
      ir_traversable_base_sptr t =
        dynamic_pointer_cast<ir_traversable_base>(*i);
      if (t)
        if (!t->traverse (v))
          break;
    }
      visiting(false);
    }
  return v.visit_end(this);
}

namespace_decl::~namespace_decl()
{
}

// </namespace_decl>

// <qualified_type_def>

/// Type of the private data of qualified_type_def.
class qualified_type_def::priv
{
  friend class qualified_type_def;

  qualified_type_def::CV    cv_quals_;
  // Before the type is canonicalized, this is used as a temporary
  // internal name.
  interned_string       temporary_internal_name_;
  // Once the type is canonicalized, this is used as the internal
  // name.
  interned_string       internal_name_;
  weak_ptr<type_base>       underlying_type_;

  priv()
    : cv_quals_(CV_NONE)
  {}

  priv(qualified_type_def::CV quals,
       type_base_sptr t)
    : cv_quals_(quals),
      underlying_type_(t)
  {}

    priv(qualified_type_def::CV quals)
    : cv_quals_(quals)
  {}
};// end class qualified_type_def::priv

/// Build the name of the current instance of qualified type.
///
/// @param fully_qualified if true, build a fully qualified name.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return a copy of the newly-built name.
string
qualified_type_def::build_name(bool fully_qualified, bool internal) const
{
  type_base_sptr t = get_underlying_type();
  if (!t)
    // The qualified type might temporarily have no underlying type,
    // especially during the construction of the type, while the
    // underlying type is not yet constructed.  In that case, let's do
    // like if the underlying type is the 'void' type.
    t = get_environment().get_void_type();

  return get_name_of_qualified_type(t, get_cv_quals(),
                    fully_qualified,
                    internal);
}

/// This function is automatically invoked whenever an instance of
/// this type is canonicalized.
///
/// It's an overload of the virtual type_base::on_canonical_type_set.
///
/// We put here what is thus meant to be executed only at the point of
/// type canonicalization.
void
qualified_type_def::on_canonical_type_set()
{clear_qualified_name();}

/// Constructor of the qualified_type_def
///
/// @param type the underlying type
///
/// @param quals a bitfield representing the const/volatile qualifiers
///
/// @param locus the location of the qualified type definition
qualified_type_def::qualified_type_def(type_base_sptr       type,
                       CV           quals,
                       const location&      locus)
  : type_or_decl_base(type->get_environment(),
              QUALIFIED_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    type_base(type->get_environment(), type->get_size_in_bits(),
          type->get_alignment_in_bits()),
    decl_base(type->get_environment(), "", locus, "",
          dynamic_pointer_cast<decl_base>(type)->get_visibility()),
    priv_(new priv(quals, type))
{
  runtime_type_instance(this);
  interned_string name = type->get_environment().intern(build_name(false));
  set_name(name);
}

/// Constructor of the qualified_type_def
///
/// @param env the environment of the type.
///
/// @param quals a bitfield representing the const/volatile qualifiers
///
/// @param locus the location of the qualified type definition
qualified_type_def::qualified_type_def(const environment& env,
                       CV quals,
                       const location& locus)
  : type_or_decl_base(env,
              QUALIFIED_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    type_base(env, /*size_in_bits=*/0,
          /*alignment_in_bits=*/0),
    decl_base(env, "", locus, ""),
    priv_(new priv(quals))
{
  runtime_type_instance(this);
  // We don't yet have an underlying type.  So for naming purpose,
  // let's temporarily pretend the underlying type is 'void'.
  interned_string name = env.intern("void");
  set_name(name);
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
qualified_type_def::hash_value() const
{
  hash_t h = set_or_get_cached_hash_value(this);
  return h;
}

/// Get the size of the qualified type def.
///
/// This is an overload for type_base::get_size_in_bits().
///
/// @return the size of the qualified type.
size_t
qualified_type_def::get_size_in_bits() const
{
  size_t s = 0;
  if (type_base_sptr ut = get_underlying_type())
    {
      // We do have the underlying type properly set, so let's make
      // the size of the qualified type match the size of its
      // underlying type.
      s = ut->get_size_in_bits();
      if (s != type_base::get_size_in_bits())
    const_cast<qualified_type_def*>(this)->set_size_in_bits(s);
    }
  return type_base::get_size_in_bits();
}

/// Compares two instances of @ref qualified_type_def.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const qualified_type_def& l, const qualified_type_def& r, change_kind* k)
{
  bool result = true;
  if (l.get_cv_quals() != r.get_cv_quals())
    {
      result = false;
      if (k)
    *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }

  if (l.get_underlying_type() != r.get_underlying_type())
    {
      result = false;
      if (k)
    {
      if (!types_have_similar_structure(l.get_underlying_type().get(),
                        r.get_underlying_type().get()))
        // Underlying type changes in which the structure of the
        // type changed are considered local changes to the
        // qualified type.
        *k |= LOCAL_TYPE_CHANGE_KIND;
      else
        *k |= SUBTYPE_CHANGE_KIND;
    }
      else
    // okay strictly speaking this is not necessary, but I am
    // putting it here to maintenance; that is, so that adding
    // subsequent clauses needed to compare two qualified types
    // later still works.
    ABG_RETURN_FALSE;
    }

  ABG_RETURN(result);
}

/// Equality operator for qualified types.
///
/// Note that this function does not check for equality of the scopes.
///
///@param o the other qualified type to compare against.
///
/// @return true iff both qualified types are equal.
bool
qualified_type_def::operator==(const decl_base& o) const
{
  const qualified_type_def* other =
    dynamic_cast<const qualified_type_def*>(&o);
  if (!other)
    return false;
  return try_canonical_compare(this, other);
}

/// Equality operator for qualified types.
///
/// Note that this function does not check for equality of the scopes.
/// Also, this re-uses the equality operator above that takes a
/// decl_base.
///
///@param o the other qualified type to compare against.
///
/// @return true iff both qualified types are equal.
bool
qualified_type_def::operator==(const type_base& o) const
{
  const decl_base* other = dynamic_cast<const decl_base*>(&o);
  if (!other)
    return false;
  return *this == *other;
}

/// Equality operator for qualified types.
///
/// Note that this function does not check for equality of the scopes.
/// Also, this re-uses the equality operator above that takes a
/// decl_base.
///
///@param o the other qualified type to compare against.
///
/// @return true iff both qualified types are equal.
bool
qualified_type_def::operator==(const qualified_type_def& o) const
{
  const decl_base* other = dynamic_cast<const decl_base*>(&o);
  if (!other)
    return false;
  return *this == *other;
}

/// Implementation for the virtual qualified name builder for @ref
/// qualified_type_def.
///
/// @param qualified_name the output parameter to hold the resulting
/// qualified name.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
void
qualified_type_def::get_qualified_name(interned_string& qualified_name,
                       bool internal) const
{qualified_name = get_qualified_name(internal);}

/// Implementation of the virtual qualified name builder/getter.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the resulting qualified name.
const interned_string&
qualified_type_def::get_qualified_name(bool internal) const
{
  const environment& env = get_environment();


  if (!get_canonical_type())
    {
      // The type hasn't been canonicalized yet. We want to return a
      // temporary name that is not cached because the structure of
      // this type (and so its name) can change until its
      // canonicalized.
      if (internal)
    {
      // We are asked to return a temporary *internal* name.
      // Lets compute it and return a reference to where it's
      // stored.
      if (priv_->temporary_internal_name_.empty())
        priv_->temporary_internal_name_ =
          env.intern(build_name(true, /*internal=*/true));
      return priv_->temporary_internal_name_;
    }
      else
    {
      // We are asked to return a temporary non-internal name.
        set_temporary_qualified_name
          (env.intern(build_name(true, /*internal=*/false)));
      return peek_temporary_qualified_name();
    }
    }
  else
    {
      // The type has already been canonicalized. We want to return
      // the definitive name and cache it.
      if (internal)
    {
      if (priv_->internal_name_.empty())
        priv_->internal_name_ =
          env.intern(build_name(/*qualified=*/true,
                     /*internal=*/true));
      return priv_->internal_name_;
    }
      else
    {
      if (peek_qualified_name().empty())
        set_qualified_name
          (env.intern(build_name(/*qualified=*/true,
                      /*internal=*/false)));
      return peek_qualified_name();
    }
    }
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
qualified_type_def::traverse(ir_node_visitor& v)
{
  if (v.type_node_has_been_visited(this))
    return true;

  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      if (type_base_sptr t = get_underlying_type())
    t->traverse(v);
      visiting(false);
    }
  bool result = v.visit_end(this);
  v.mark_type_node_as_visited(this);
  return result;
}

qualified_type_def::~qualified_type_def()
{
}

/// Getter of the const/volatile qualifier bit field
qualified_type_def::CV
qualified_type_def::get_cv_quals() const
{return priv_->cv_quals_;}

/// Setter of the const/value qualifiers bit field
void
qualified_type_def::set_cv_quals(CV cv_quals)
{priv_->cv_quals_ = cv_quals;}

/// Compute and return the string prefix or suffix representing the
/// qualifiers hold by the current instance of @ref
/// qualified_type_def.
///
/// @return the newly-built cv string.
string
qualified_type_def::get_cv_quals_string_prefix() const
{return get_string_representation_of_cv_quals(priv_->cv_quals_);}

/// Getter of the underlying type
type_base_sptr
qualified_type_def::get_underlying_type() const
{return priv_->underlying_type_.lock();}

/// Setter of the underlying type.
///
/// @param t the new underlying type.
void
qualified_type_def::set_underlying_type(const type_base_sptr& t)
{
  ABG_ASSERT(t);
  priv_->underlying_type_ = t;
  // Now we need to update other properties that depend on the new underlying type.
  set_size_in_bits(t->get_size_in_bits());
  set_alignment_in_bits(t->get_alignment_in_bits());
  interned_string name = get_environment().intern(build_name(false));
  set_name(name);
  if (scope_decl* s = get_scope())
      {
    // Now that the name has been updated, we need to update the
    // lookup maps accordingly.
    scope_decl::declarations::iterator i;
    if (s->find_iterator_for_member(this, i))
      maybe_update_types_lookup_map(*i);
    else
      ABG_ASSERT_NOT_REACHED;
      }
}

/// Non-member equality operator for @ref qualified_type_def
///
/// @param l the left-hand side of the equality operator
///
/// @param r the right-hand side of the equality operator
///
/// @return true iff @p l and @p r equals.
bool
operator==(const qualified_type_def_sptr& l, const qualified_type_def_sptr& r)
{
  if (l.get() == r.get())
    return true;
  if (!!l != !!r)
    return false;

  return *l == *r;
}

/// Non-member inequality operator for @ref qualified_type_def
///
/// @param l the left-hand side of the equality operator
///
/// @param r the right-hand side of the equality operator
///
/// @return true iff @p l and @p r equals.
bool
operator!=(const qualified_type_def_sptr& l, const qualified_type_def_sptr& r)
{return ! operator==(l, r);}

/// Overloaded bitwise OR operator for cv qualifiers.
qualified_type_def::CV
operator|(qualified_type_def::CV lhs, qualified_type_def::CV rhs)
{
  return static_cast<qualified_type_def::CV>
    (static_cast<unsigned>(lhs) | static_cast<unsigned>(rhs));
}

/// Overloaded bitwise |= operator for cv qualifiers.
qualified_type_def::CV&
operator|=(qualified_type_def::CV& l, qualified_type_def::CV r)
{
  l = l | r;
  return l;
}

/// Overloaded bitwise &= operator for cv qualifiers.
qualified_type_def::CV&
operator&=(qualified_type_def::CV& l, qualified_type_def::CV r)
{
  l = l & r;
  return l;
}

/// Overloaded bitwise AND operator for CV qualifiers.
qualified_type_def::CV
operator&(qualified_type_def::CV lhs, qualified_type_def::CV rhs)
{
    return static_cast<qualified_type_def::CV>
    (static_cast<unsigned>(lhs) & static_cast<unsigned>(rhs));
}

/// Overloaded bitwise inverting operator for CV qualifiers.
qualified_type_def::CV
operator~(qualified_type_def::CV q)
{return static_cast<qualified_type_def::CV>(~static_cast<unsigned>(q));}

/// Streaming operator for qualified_type_decl::CV
///
/// @param o the output stream to serialize the cv qualifier to.
///
/// @param cv the cv qualifier to serialize.
///
/// @return the output stream used.
std::ostream&
operator<<(std::ostream& o, qualified_type_def::CV cv)
{
  string str;

  switch (cv)
    {
    case qualified_type_def::CV_NONE:
      str = "none";
      break;
    case qualified_type_def::CV_CONST:
      str = "const";
      break;
    case qualified_type_def::CV_VOLATILE:
      str = "volatile";
      break;
    case qualified_type_def::CV_RESTRICT:
      str = "restrict";
      break;
    }

  o << str;
  return o;
}

// </qualified_type_def>

//<pointer_type_def definitions>

/// Private data structure of the @ref pointer_type_def.
struct pointer_type_def::priv
{
  type_base_wptr pointed_to_type_;
  type_base* naked_pointed_to_type_;
  interned_string internal_qualified_name_;
  interned_string temp_internal_qualified_name_;

  priv(const type_base_sptr& t)
    : pointed_to_type_(type_or_void(t, t->get_environment())),
      naked_pointed_to_type_(t.get())
  {}

  priv()
    : naked_pointed_to_type_()
  {}
}; //end struct pointer_type_def

/// This function is automatically invoked whenever an instance of
/// this type is canonicalized.
///
/// It's an overload of the virtual type_base::on_canonical_type_set.
///
/// We put here what is thus meant to be executed only at the point of
/// type canonicalization.
void
pointer_type_def::on_canonical_type_set()
{clear_qualified_name();}


///Constructor of @ref pointer_type_def.
///
/// @param pointed_to the pointed-to type.
///
/// @param size_in_bits the size of the type, in bits.
///
/// @param align_in_bits the alignment of the type, in bits.
///
/// @param locus the source location where the type was defined.
pointer_type_def::pointer_type_def(const type_base_sptr&    pointed_to,
                   size_t           size_in_bits,
                   size_t           align_in_bits,
                   const location&      locus)
  : type_or_decl_base(pointed_to->get_environment(),
              POINTER_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    type_base(pointed_to->get_environment(), size_in_bits, align_in_bits),
    decl_base(pointed_to->get_environment(), "", locus, ""),
    priv_(new priv(pointed_to))
{
  runtime_type_instance(this);
  try
    {
      ABG_ASSERT(pointed_to);
      const environment& env = pointed_to->get_environment();
      decl_base_sptr pto = dynamic_pointer_cast<decl_base>(pointed_to);
      string name = (pto ? pto->get_name() : string("void")) + "*";
      set_name(env.intern(name));
      if (pto)
    set_visibility(pto->get_visibility());
    }
  catch (...)
    {}
}

///Constructor of @ref pointer_type_def.
///
/// @param env the environment of the type.
///
/// @param size_in_bits the size of the type, in bits.
///
/// @param align_in_bits the alignment of the type, in bits.
///
/// @param locus the source location where the type was defined.
pointer_type_def::pointer_type_def(const environment& env, size_t size_in_bits,
                   size_t alignment_in_bits,
                   const location& locus)
  : type_or_decl_base(env,
              POINTER_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    type_base(env, size_in_bits, alignment_in_bits),
    decl_base(env, "", locus, ""),
    priv_(new priv())
{
  runtime_type_instance(this);
  string name = string("void") + "*";
  set_name(env.intern(name));
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
pointer_type_def::hash_value() const
{
  hash_t h = set_or_get_cached_hash_value(this);
  return h;
}

/// Set the pointed-to type of the pointer.
///
/// @param t the new pointed-to type.
void
pointer_type_def::set_pointed_to_type(const type_base_sptr& t)
{
  ABG_ASSERT(t);
  priv_->pointed_to_type_ = t;
  priv_->naked_pointed_to_type_ = t.get();

  try
    {
      const environment& env = t->get_environment();
      decl_base_sptr pto = dynamic_pointer_cast<decl_base>(t);
      string name = (pto ? pto->get_name() : string("void")) + "*";
      set_name(env.intern(name));
      if (pto)
    set_visibility(pto->get_visibility());
    }
  catch (...)
    {}
}

/// Compares two instances of @ref pointer_type_def.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const pointer_type_def& l, const pointer_type_def& r, change_kind* k)
{
  type_base_sptr p1 = l.get_pointed_to_type(), p2 = r.get_pointed_to_type();
  bool result = p1 == p2;
  if (!result)
    if (k)
      {
    if (!types_have_similar_structure(&l, &r))
      // pointed-to type changes in which the structure of the
      // type changed are considered local changes to the pointer
      // type.
      *k |= LOCAL_TYPE_CHANGE_KIND;
    *k |= SUBTYPE_CHANGE_KIND;
      }

  ABG_RETURN(result);
}

/// Return true iff both instances of pointer_type_def are equal.
///
/// Note that this function does not check for the scopes of the this
/// types.
bool
pointer_type_def::operator==(const decl_base& o) const
{
  const pointer_type_def* other = is_pointer_type(&o);
  if (!other)
    return false;
  return try_canonical_compare(this, other);
}

/// Return true iff both instances of pointer_type_def are equal.
///
/// Note that this function does not check for the scopes of the
/// types.
///
/// @param other the other type to compare against.
///
/// @return true iff @p other equals the current instance.
bool
pointer_type_def::operator==(const type_base& other) const
{
  const decl_base* o = is_decl(&other);
  if (!o)
    return false;
  return *this == *o;
}

/// Return true iff both instances of pointer_type_def are equal.
///
/// Note that this function does not check for the scopes of the
/// types.
///
/// @param other the other type to compare against.
///
/// @return true iff @p other equals the current instance.
bool
pointer_type_def::operator==(const pointer_type_def& other) const
{
  const decl_base& o = other;
  return *this == o;
}

/// Getter of the pointed-to type.
///
/// @return the pointed-to type.
const type_base_sptr
pointer_type_def::get_pointed_to_type() const
{return priv_->pointed_to_type_.lock();}

/// Getter of a naked pointer to the pointed-to type.
///
/// @return a naked pointed to the pointed-to type.
type_base*
pointer_type_def::get_naked_pointed_to_type() const
{return priv_->naked_pointed_to_type_;}

/// Build and return the qualified name of the current instance of
/// @ref pointer_type_def.
///
/// @param qn output parameter.  The resulting qualified name.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
void
pointer_type_def::get_qualified_name(interned_string& qn, bool internal) const
{qn = get_qualified_name(internal);}

/// Build, cache and return the qualified name of the current instance
/// of @ref pointer_type_def.  Subsequent invocations of this function
/// return the cached value.
///
/// Note that this function should work even if the underlying type is
/// momentarily empty.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the resulting qualified name.
const interned_string&
pointer_type_def::get_qualified_name(bool internal) const
{
  type_base* pointed_to_type = get_naked_pointed_to_type();
  pointed_to_type = look_through_decl_only_type(pointed_to_type);

  if (internal)
    {
      if (get_canonical_type())
    {
      if (priv_->internal_qualified_name_.empty())
        if (pointed_to_type)
          priv_->internal_qualified_name_ =
        pointer_declaration_name(this,
                     /*variable_name=*/"",
                     /*qualified_name=*/
                     is_typedef(pointed_to_type)
                     ? false
                     : true,
                     /*internal=*/true);
        return priv_->internal_qualified_name_;
    }
      else
    {
      // As the type hasn't yet been canonicalized, its structure
      // (and so its name) can change.  So let's invalidate the
      // cache where we store its name at each invocation of this
      // function.
      if (pointed_to_type)
        if (priv_->temp_internal_qualified_name_.empty())
          priv_->temp_internal_qualified_name_ =
        pointer_declaration_name(this,
                     /*variable_name=*/"",
                     /*qualified_name=*/
                     is_typedef(pointed_to_type)
                     ? false
                     : true,
                     /*internal=*/true);
      return priv_->temp_internal_qualified_name_;
    }
    }
  else
    {
      if (get_naked_canonical_type())
    {
      if (decl_base::peek_qualified_name().empty())
        set_qualified_name
          (pointer_declaration_name(this,
                    /*variable_name=*/"",
                    /*qualified_name=*/true,
                    /*internal=*/false));
      return decl_base::peek_qualified_name();
    }
      else
    {
      // As the type hasn't yet been canonicalized, its structure
      // (and so its name) can change.  So let's invalidate the
      // cache where we store its name at each invocation of this
      // function.
      if (pointed_to_type)
        set_qualified_name
          (pointer_declaration_name(this,
                    /*variable_name=*/"",
                    /*qualified_name=*/true,
                    /*internal=*/false));
      return decl_base::peek_qualified_name();
    }
    }
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
pointer_type_def::traverse(ir_node_visitor& v)
{
  if (v.type_node_has_been_visited(this))
    return true;

  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      if (type_base_sptr t = get_pointed_to_type())
    t->traverse(v);
      visiting(false);
    }

  bool result = v.visit_end(this);
  v.mark_type_node_as_visited(this);
  return result;
}

pointer_type_def::~pointer_type_def()
{}

/// Turn equality of shared_ptr of @ref pointer_type_def into a deep
/// equality; that is, make it compare the pointed to objects too.
///
/// @param l the shared_ptr of @ref pointer_type_def on left-hand-side
/// of the equality.
///
/// @param r the shared_ptr of @ref pointer_type_def on
/// right-hand-side of the equality.
///
/// @return true if the @ref pointer_type_def pointed to by the
/// shared_ptrs are equal, false otherwise.
bool
operator==(const pointer_type_def_sptr& l, const pointer_type_def_sptr& r)
{
  if (l.get() == r.get())
    return true;
  if (!!l != !!r)
    return false;

  return *l == *r;
}

/// Turn inequality of shared_ptr of @ref pointer_type_def into a deep
/// equality; that is, make it compare the pointed to objects too.
///
/// @param l the shared_ptr of @ref pointer_type_def on left-hand-side
/// of the equality.
///
/// @param r the shared_ptr of @ref pointer_type_def on
/// right-hand-side of the equality.
///
/// @return true iff the @ref pointer_type_def pointed to by the
/// shared_ptrs are different.
bool
operator!=(const pointer_type_def_sptr& l, const pointer_type_def_sptr& r)
{return !operator==(l, r);}

// </pointer_type_def definitions>

// <reference_type_def definitions>

/// Private data structure of the @ref reference_type_def type.
struct reference_type_def::priv
{

  type_base_wptr    pointed_to_type_;
  bool          is_lvalue_;
  interned_string   internal_qualified_name_;
  interned_string   temp_internal_qualified_name_;

  priv(const type_base_sptr& t, bool is_lvalue)
    : pointed_to_type_(type_or_void(t, t->get_environment())),
      is_lvalue_(is_lvalue)
  {}

  priv(bool is_lvalue)
    : is_lvalue_(is_lvalue)
  {}

  priv() = delete;
};

/// This function is automatically invoked whenever an instance of
/// this type is canonicalized.
///
/// It's an overload of the virtual type_base::on_canonical_type_set.
///
/// We put here what is thus meant to be executed only at the point of
/// type canonicalization.
void
reference_type_def::on_canonical_type_set()
{clear_qualified_name();}

/// Constructor of the reference_type_def type.
///
/// @param pointed_to the pointed to type.
///
/// @param lvalue wether the reference is an lvalue reference.  If
/// false, the reference is an rvalue one.
///
/// @param size_in_bits the size of the type, in bits.
///
/// @param align_in_bits the alignment of the type, in bits.
///
/// @param locus the source location of the type.
reference_type_def::reference_type_def(const type_base_sptr pointed_to,
                       bool         lvalue,
                       size_t           size_in_bits,
                       size_t           align_in_bits,
                       const location&      locus)
  : type_or_decl_base(pointed_to->get_environment(),
              REFERENCE_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    type_base(pointed_to->get_environment(), size_in_bits, align_in_bits),
    decl_base(pointed_to->get_environment(), "", locus, ""),
    priv_(new priv(pointed_to, lvalue))
{
  runtime_type_instance(this);

  try
    {
      decl_base_sptr pto = dynamic_pointer_cast<decl_base>(pointed_to);
      string name;
      if (pto)
    {
      set_visibility(pto->get_visibility());
      name = string(pto->get_name()) + "&";
    }
      else
    name = string(get_type_name(is_function_type(pointed_to),
                    /*qualified_name=*/true)) + "&";

      if (!is_lvalue())
    name += "&";
      const environment& env = pointed_to->get_environment();
      set_name(env.intern(name));
    }
  catch (...)
    {}
}

/// Constructor of the reference_type_def type.
///
/// This one creates a type that has no pointed-to type, temporarily.
/// This is useful for cases where the underlying type is not yet
/// available.  It can be set later using
/// reference_type_def::set_pointed_to_type().
///
/// @param env the environment of the type.
///
/// @param lvalue wether the reference is an lvalue reference.  If
/// false, the reference is an rvalue one.
///
/// @param size_in_bits the size of the type, in bits.
///
/// @param align_in_bits the alignment of the type, in bits.
///
/// @param locus the source location of the type.
reference_type_def::reference_type_def(const environment& env, bool lvalue,
                       size_t size_in_bits,
                       size_t alignment_in_bits,
                       const location& locus)
  : type_or_decl_base(env,
              REFERENCE_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    type_base(env, size_in_bits, alignment_in_bits),
    decl_base(env, "", locus, ""),
    priv_(new priv(lvalue))
{
  runtime_type_instance(this);
  string name = "void&";
  if (!is_lvalue())
    name += "&";

  set_name(env.intern(name));
  priv_->pointed_to_type_ = type_base_wptr(env.get_void_type());
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
reference_type_def::hash_value() const
{
  hash_t h = set_or_get_cached_hash_value(this);
  return h;
}

/// Setter of the pointed_to type of the current reference type.
///
/// @param pointed_to the new pointed to type.
void
reference_type_def::set_pointed_to_type(type_base_sptr& pointed_to_type)
{
  ABG_ASSERT(pointed_to_type);
  priv_->pointed_to_type_ = pointed_to_type;

  decl_base_sptr pto;
  try
    {pto = dynamic_pointer_cast<decl_base>(pointed_to_type);}
  catch (...)
    {}

  if (pto)
    {
      set_visibility(pto->get_visibility());
      string name = string(pto->get_name()) + "&";
      if (!is_lvalue())
    name += "&";
      const environment& env = pto->get_environment();
      set_name(env.intern(name));
    }
}

/// Compares two instances of @ref reference_type_def.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const reference_type_def& l, const reference_type_def& r, change_kind* k)
{
  if (l.is_lvalue() != r.is_lvalue())
    {
      if (k)
    *k |= LOCAL_TYPE_CHANGE_KIND;
      ABG_RETURN_FALSE;
    }
  type_base_sptr p1 = l.get_pointed_to_type(), p2 = r.get_pointed_to_type();
  bool result = p1 == p2;
  if (!result)
    if (k)
      {
    if (!types_have_similar_structure(&l, &r))
      *k |= LOCAL_TYPE_CHANGE_KIND;
    *k |= SUBTYPE_CHANGE_KIND;
      }
  ABG_RETURN(result);
}

/// Equality operator of the @ref reference_type_def type.
///
/// @param o the other instance of @ref reference_type_def to compare
/// against.
///
/// @return true iff the two instances are equal.
bool
reference_type_def::operator==(const decl_base& o) const
{
  const reference_type_def* other =
    dynamic_cast<const reference_type_def*>(&o);
  if (!other)
    return false;
  return try_canonical_compare(this, other);
}

/// Equality operator of the @ref reference_type_def type.
///
/// @param o the other instance of @ref reference_type_def to compare
/// against.
///
/// @return true iff the two instances are equal.
bool
reference_type_def::operator==(const type_base& o) const
{
  const decl_base* other = dynamic_cast<const decl_base*>(&o);
  if (!other)
    return false;
  return *this == *other;
}

/// Equality operator of the @ref reference_type_def type.
///
/// @param o the other instance of @ref reference_type_def to compare
/// against.
///
/// @return true iff the two instances are equal.
bool
reference_type_def::operator==(const reference_type_def& o) const
{
  const decl_base* other = dynamic_cast<const decl_base*>(&o);
  if (!other)
    return false;
  return *this == *other;
}

type_base_sptr
reference_type_def::get_pointed_to_type() const
{return priv_->pointed_to_type_.lock();}

bool
reference_type_def::is_lvalue() const
{return priv_->is_lvalue_;}

/// Build and return the qualified name of the current instance of the
/// @ref reference_type_def.
///
/// @param qn output parameter.  Is set to the newly-built qualified
/// name of the current instance of @ref reference_type_def.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
void
reference_type_def::get_qualified_name(interned_string& qn, bool internal) const
{qn = get_qualified_name(internal);}

/// Build, cache and return the qualified name of the current instance
/// of the @ref reference_type_def.  Subsequent invocations of this
/// function return the cached value.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the newly-built qualified name of the current instance of
/// @ref reference_type_def.
const interned_string&
reference_type_def::get_qualified_name(bool internal) const
{
  type_base_sptr pointed_to_type = get_pointed_to_type();
  pointed_to_type = look_through_decl_only_type(pointed_to_type);

  if (internal)
    {
      if (get_canonical_type())
    {
      if (priv_->internal_qualified_name_.empty())
        if (pointed_to_type)
          priv_->internal_qualified_name_ =
        get_name_of_reference_to_type(*pointed_to_type,
                          is_lvalue(),
                          /*qualified_name=*/
                          is_typedef(pointed_to_type)
                          ? false
                          : true,
                          /*internal=*/true);
      return priv_->internal_qualified_name_;
    }
      else
    {
      // As the type hasn't yet been canonicalized, its structure
      // (and so its name) can change.  So let's invalidate the
      // cache where we store its name at each invocation of this
      // function.
      if (pointed_to_type)
        if (priv_->temp_internal_qualified_name_.empty())
          priv_->temp_internal_qualified_name_ =
        get_name_of_reference_to_type(*pointed_to_type,
                          is_lvalue(),
                          /*qualified_name=*/
                          is_typedef(pointed_to_type)
                          ? false
                          : true,
                          /*internal=*/true);
      return priv_->temp_internal_qualified_name_;
    }
    }
  else
    {
      if (get_naked_canonical_type())
    {
      set_qualified_name
        (get_name_of_reference_to_type(*pointed_to_type,
                       is_lvalue(),
                       /*qualified_name=*/true,
                       /*internal=*/false));
      return decl_base::peek_qualified_name();
    }
      else
    {
      // As the type hasn't yet been canonicalized, its structure
      // (and so its name) can change.  So let's invalidate the
      // cache where we store its name at each invocation of this
      // function.
      if (pointed_to_type)
        set_qualified_name
          (get_name_of_reference_to_type(*pointed_to_type,
                         is_lvalue(),
                         /*qualified_name=*/true,
                         /*internal=*/false));
      return decl_base::peek_qualified_name();
    }
    }
}

/// Get the pretty representation of the current instance of @ref
/// reference_type_def.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
///
/// @param qualified_name if true, names emitted in the pretty
/// representation are fully qualified.
///
/// @return the pretty representatin of the @ref reference_type_def.
string
reference_type_def::get_pretty_representation(bool internal,
                          bool qualified_name) const
{
  string result =
    get_name_of_reference_to_type(*look_through_decl_only_type
                  (get_pointed_to_type()),
                  is_lvalue(),
                  qualified_name,
                  internal);

  return result;
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
reference_type_def::traverse(ir_node_visitor& v)
{
  if (v.type_node_has_been_visited(this))
    return true;

  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      if (type_base_sptr t = get_pointed_to_type())
    t->traverse(v);
      visiting(false);
    }

  bool result = v.visit_end(this);
  v.mark_type_node_as_visited(this);
  return result;
}

reference_type_def::~reference_type_def()
{}

/// Turn equality of shared_ptr of @ref reference_type_def into a deep
/// equality; that is, make it compare the pointed to objects too.
///
/// @param l the shared_ptr of @ref reference_type_def on left-hand-side
/// of the equality.
///
/// @param r the shared_ptr of @ref reference_type_def on
/// right-hand-side of the equality.
///
/// @return true if the @ref reference_type_def pointed to by the
/// shared_ptrs are equal, false otherwise.
bool
operator==(const reference_type_def_sptr& l, const reference_type_def_sptr& r)
{
  if (l.get() == r.get())
    return true;
  if (!!l != !!r)
    return false;

  return *l == *r;
}

/// Turn inequality of shared_ptr of @ref reference_type_def into a deep
/// equality; that is, make it compare the pointed to objects too.
///
/// @param l the shared_ptr of @ref reference_type_def on left-hand-side
/// of the equality.
///
/// @param r the shared_ptr of @ref reference_type_def on
/// right-hand-side of the equality.
///
/// @return true iff the @ref reference_type_def pointed to by the
/// shared_ptrs are different.
bool
operator!=(const reference_type_def_sptr& l, const reference_type_def_sptr& r)
{return !operator==(l, r);}

// </reference_type_def definitions>

// <ptr_to_mbr_type definitions>

/// The private data type of @ref ptr_to_mbr_type.
struct ptr_to_mbr_type::priv
{
  // The type of the data member this pointer-to-member-type
  // designates.
  type_base_sptr dm_type_;
  // The class (or typedef to potentially qualified class) containing
  // the data member this pointer-to-member-type designates.
  type_base_sptr containing_type_;
  interned_string internal_qualified_name_;
  interned_string temp_internal_qualified_name_;

  priv()
  {}

  priv(const type_base_sptr& dm_type, const type_base_sptr& containing_type)
    :  dm_type_(dm_type),
       containing_type_(containing_type)
  {}
};// end struct ptr_to_mbr_type::priv

/// A constructor for a @ref ptr_to_mbr_type type.
///
/// @param env the environment to construct the @ref ptr_to_mbr_type in.
///
/// @param member_type the member type of the of the @ref
/// ptr_to_mbr_type to construct.
///
/// @param containing_type the containing type of the @ref
/// ptr_to_mbr_type to construct.
///
/// @param size_in_bits the size (in bits) of the resulting type.
///
/// @param alignment_in_bits the alignment (in bits) of the resulting
/// type.
///
/// @param locus the source location of the definition of the
/// resulting type.
ptr_to_mbr_type::ptr_to_mbr_type(const environment&     env,
                 const type_base_sptr&      member_type,
                 const type_base_sptr&      containing_type,
                 size_t         size_in_bits,
                 size_t         alignment_in_bits,
                 const location&        locus)
  : type_or_decl_base(env,
              POINTER_TO_MEMBER_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    type_base(env, size_in_bits, alignment_in_bits),
    decl_base(env, "", locus, ""),
    priv_(new priv(member_type, containing_type))
{
  runtime_type_instance(this);
  ABG_ASSERT(member_type);
  ABG_ASSERT(containing_type);
  set_is_anonymous(false);
}

/// Getter of the name of the current ptr-to-mbr-type.
///
/// This just returns the qualified name.
///
/// @return the (qualified) name of the the type.
const interned_string&
ptr_to_mbr_type::get_name() const
{
  return get_qualified_name(/*internal=*/false);
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
ptr_to_mbr_type::hash_value() const
{
  hash_t h = set_or_get_cached_hash_value(this);
  return h;
}

/// Getter of the member type of the current @ref ptr_to_mbr_type.
///
/// @return the type of the member referred to by the current
/// @ptr_to_mbr_type.
const type_base_sptr&
ptr_to_mbr_type::get_member_type() const
{return priv_->dm_type_;}

/// Getter of the type containing the member pointed-to by the current
/// @ref ptr_to_mbr_type.
///
/// @return the type containing the member pointed-to by the current
/// @ref ptr_to_mbr_type.
const type_base_sptr&
ptr_to_mbr_type::get_containing_type() const
{return priv_->containing_type_;}

/// Equality operator for the current @ref ptr_to_mbr_type.
///
///@param o the other instance of @ref ptr_to_mbr_type to compare the
///current instance to.
///
/// @return true iff the current @ref ptr_to_mbr_type equals @p o.
bool
ptr_to_mbr_type::operator==(const decl_base& o) const
{
  const ptr_to_mbr_type* other =
    dynamic_cast<const ptr_to_mbr_type*>(&o);
  if (!other)
    return false;
  return try_canonical_compare(this, other);
}

/// Equality operator for the current @ref ptr_to_mbr_type.
///
///@param o the other instance of @ref ptr_to_mbr_type to compare the
///current instance to.
///
/// @return true iff the current @ref ptr_to_mbr_type equals @p o.
bool
ptr_to_mbr_type::operator==(const type_base& o) const
{
  const decl_base* other = dynamic_cast<const decl_base*>(&o);
  if (!other)
    return false;
  return *this == *other;
}

/// Equality operator for the current @ref ptr_to_mbr_type.
///
///@param o the other instance of @ref ptr_to_mbr_type to compare the
///current instance to.
///
/// @return true iff the current @ref ptr_to_mbr_type equals @p o.
bool
ptr_to_mbr_type::operator==(const ptr_to_mbr_type& o) const
{
  const decl_base* other = dynamic_cast<const decl_base*>(&o);
  if (!other)
    return false;
  return *this == *other;
}

/// Get the qualified name for the current @ref ptr_to_mbr_type.
///
/// @param qualified_name out parameter.  This is set to the name of
/// the current @ref ptr_to_mbr_type.
///
/// @param internal if this is true, then the qualified name is for
/// the purpose of type canoicalization.
void
ptr_to_mbr_type::get_qualified_name(interned_string& qualified_name,
                    bool internal) const
{qualified_name = get_qualified_name(internal);}

/// Get the qualified name for the current @ref ptr_to_mbr_type.
///
/// @param internal if this is true, then the qualified name is for
/// the purpose of type canoicalization.
///
/// @return the qualified name for the current @ref ptr_to_mbr_type.
const interned_string&
ptr_to_mbr_type::get_qualified_name(bool internal) const
{
  type_base_sptr member_type = get_member_type();
  type_base_sptr containing_type = get_containing_type();

  if (internal)
    {
      if (get_canonical_type())
    {
      if (priv_->internal_qualified_name_.empty())
        priv_->internal_qualified_name_ =
          ptr_to_mbr_declaration_name(this, "",
                      /*qualified=*/true,
                      internal);
      return  priv_->internal_qualified_name_;
    }
      else
    {
      priv_->temp_internal_qualified_name_ =
        ptr_to_mbr_declaration_name(this, "", /*qualified=*/true, internal);
      return priv_->temp_internal_qualified_name_;
    }
    }
  else
    {
      set_qualified_name
    (ptr_to_mbr_declaration_name(this, "", /*qualified=*/true,
                     /*internal=*/false));
      return decl_base::peek_qualified_name();
    }
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function for @ref ptr_to_mbr_type.
///
/// @param v the visitor used on the current instance.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
ptr_to_mbr_type::traverse(ir_node_visitor& v)
{
  if (v.type_node_has_been_visited(this))
    return true;

  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      if (type_base_sptr t = get_member_type())
    t->traverse(v);

      if (type_base_sptr t = get_containing_type())
    t->traverse(v);
      visiting(false);
    }

  bool result = v.visit_end(this);
  v.mark_type_node_as_visited(this);
  return result;
}

/// Desctructor for @ref ptr_to_mbr_type.
ptr_to_mbr_type::~ptr_to_mbr_type()
{}


/// Compares two instances of @ref ptr_to_mbr_type.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const ptr_to_mbr_type& l, const ptr_to_mbr_type& r, change_kind* k)
{
  bool result = true;

  if (!(l.decl_base::operator==(r)))
    {
      result = false;
      if (k)
    *k |= LOCAL_TYPE_CHANGE_KIND;
      else
    result = false;
    }

  if (l.get_member_type() != r.get_member_type())
    {
      if (k)
    {
      if (!types_have_similar_structure(&l, &r))
        *k |= LOCAL_TYPE_CHANGE_KIND;
      *k |= SUBTYPE_CHANGE_KIND;
    }
      result = false;
    }

  if (l.get_containing_type() != r.get_containing_type())
    {
      if (k)
    {
      if (!types_have_similar_structure(&l, &r))
        *k |= LOCAL_TYPE_CHANGE_KIND;
      *k |= SUBTYPE_CHANGE_KIND;
    }
      result = false;
    }

  ABG_RETURN(result);
}

// </ptr_to_mbr_type definitions>

// <array_type_def definitions>

// <array_type_def::subrange_type>
array_type_def::subrange_type::~subrange_type() = default;

// <array_type_def::subrante_type::bound_value>

/// Default constructor of the @ref
/// array_type_def::subrange_type::bound_value class.
///
/// Constructs an unsigned bound_value of value zero.
array_type_def::subrange_type::bound_value::bound_value()
  : s_(UNSIGNED_SIGNEDNESS)
{
  v_.unsigned_ = 0;
}

/// Initialize an unsigned bound_value with a given value.
///
/// @param v the initial bound value.
array_type_def::subrange_type::bound_value::bound_value(uint64_t v)
  : s_(UNSIGNED_SIGNEDNESS)
{
  v_.unsigned_ = v;
}

/// Initialize a signed bound_value with a given value.
///
/// @param v the initial bound value.
array_type_def::subrange_type::bound_value::bound_value(int64_t v)
  : s_(SIGNED_SIGNEDNESS)
{
  v_.signed_ = v;
}

/// Getter of the signedness (unsigned VS signed) of the bound value.
///
/// @return the signedness of the bound value.
enum array_type_def::subrange_type::bound_value::signedness
array_type_def::subrange_type::bound_value::get_signedness() const
{return s_;}

/// Setter of the signedness (unsigned VS signed) of the bound value.
///
/// @param s the new signedness of the bound value.
void
array_type_def::subrange_type::bound_value::set_signedness(enum signedness s)
{ s_ = s;}

/// Getter of the bound value as a signed value.
///
/// @return the bound value as signed.
int64_t
array_type_def::subrange_type::bound_value::get_signed_value() const
{return v_.signed_;
}

/// Getter of the bound value as an unsigned value.
///
/// @return the bound value as unsigned.
uint64_t
array_type_def::subrange_type::bound_value::get_unsigned_value()
{return v_.unsigned_;}

/// Setter of the bound value as unsigned.
///
/// @param v the new unsigned value.
void
array_type_def::subrange_type::bound_value::set_unsigned(uint64_t v)
{
    s_ = UNSIGNED_SIGNEDNESS;
  v_.unsigned_ = v;
}

/// Setter of the bound value as signed.
///
/// @param v the new signed value.
void
array_type_def::subrange_type::bound_value::set_signed(int64_t v)
{
  s_ = SIGNED_SIGNEDNESS;
  v_.signed_ = v;
}

/// Equality operator of the bound value.
///
/// @param v the other bound value to compare with.
///
/// @return true iff the current bound value equals @p v.
bool
array_type_def::subrange_type::bound_value::operator==(const bound_value& v) const
{
  return s_ == v.s_ && v_.unsigned_ == v.v_.unsigned_;
}

// </array_type_def::subrante_type::bound_value>

struct array_type_def::subrange_type::priv
{
  bound_value       lower_bound_;
  bound_value       upper_bound_;
  type_base_wptr    underlying_type_;
  translation_unit::language language_;
  bool          infinite_;

  priv(bound_value ub,
       translation_unit::language l = translation_unit::LANG_C11)
    : upper_bound_(ub), language_(l), infinite_(false)
  {}

  priv(bound_value lb, bound_value ub,
       translation_unit::language l = translation_unit::LANG_C11)
    : lower_bound_(lb), upper_bound_(ub),
      language_(l), infinite_(false)
  {}

  priv(bound_value lb, bound_value ub, const type_base_sptr &u,
       translation_unit::language l = translation_unit::LANG_C11)
    : lower_bound_(lb), upper_bound_(ub), underlying_type_(u),
      language_(l), infinite_(false)
  {}
};

/// Constructor of an array_type_def::subrange_type type.
///
/// @param env the environment this type was created from.
///
/// @param name the name of the subrange type.
///
/// @param lower_bound the lower bound of the array.  This is
/// generally zero (at least for C and C++).
///
/// @param upper_bound the upper bound of the array.
///
/// @param underlying_type the underlying type of the subrange type.
///
/// @param loc the source location where the type is defined.
array_type_def::subrange_type::subrange_type(const environment& env,
                         const string&  name,
                         bound_value    lower_bound,
                         bound_value    upper_bound,
                         const type_base_sptr& utype,
                         const location&    loc,
                         translation_unit::language l)
  : type_or_decl_base(env, SUBRANGE_TYPE | ABSTRACT_TYPE_BASE | ABSTRACT_DECL_BASE),
    type_base(env,
          utype
          ? utype->get_size_in_bits()
          : 0,
          0),
    decl_base(env, name, loc, ""),
    priv_(new priv(lower_bound, upper_bound, utype, l))
{
  runtime_type_instance(this);
}

/// Constructor of the array_type_def::subrange_type type.
///
/// @param env the environment this type is being created in.
///
/// @param name the name of the subrange type.
///
/// @param lower_bound the lower bound of the array.  This is
/// generally zero (at least for C and C++).
///
/// @param upper_bound the upper bound of the array.
///
/// @param loc the source location where the type is defined.
///
/// @param l the language that generated this subrange.
array_type_def::subrange_type::subrange_type(const environment& env,
                         const string&  name,
                         bound_value    lower_bound,
                         bound_value    upper_bound,
                         const location&    loc,
                         translation_unit::language l)
  : type_or_decl_base(env, SUBRANGE_TYPE | ABSTRACT_TYPE_BASE | ABSTRACT_DECL_BASE),
    type_base(env, /*size-in-bits=*/0, /*alignment=*/0),
    decl_base(env, name, loc, ""),
    priv_(new priv(lower_bound, upper_bound, l))
{
  runtime_type_instance(this);
}

/// Constructor of the array_type_def::subrange_type type.
///
/// @param env the environment this type is being created from.
///
/// @param name of the name of type.
///
/// @param upper_bound the upper bound of the array.  The lower bound
/// is considered to be zero.
///
/// @param loc the source location of the type.
///
/// @param the language that generated this type.
array_type_def::subrange_type::subrange_type(const environment& env,
                         const string&  name,
                         bound_value    upper_bound,
                         const location&    loc,
                         translation_unit::language l)
  : type_or_decl_base(env, SUBRANGE_TYPE | ABSTRACT_TYPE_BASE | ABSTRACT_DECL_BASE),
    type_base(env, upper_bound.get_unsigned_value(), 0),
    decl_base(env, name, loc, ""),
    priv_(new priv(upper_bound, l))
{
  runtime_type_instance(this);
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
array_type_def::subrange_type::hash_value() const
{
  hash_t h = set_or_get_cached_hash_value(this);
  return h;
}

/// Getter of the underlying type of the subrange, that is, the type
/// that defines the range.
///
/// @return the underlying type.
type_base_sptr
array_type_def::subrange_type::get_underlying_type() const
{return priv_->underlying_type_.lock();}

/// Setter of the underlying type of the subrange, that is, the type
/// that defines the range.
///
/// @param u the new underlying type.
void
array_type_def::subrange_type::set_underlying_type(const type_base_sptr &u)
{
  ABG_ASSERT(priv_->underlying_type_.expired());
  priv_->underlying_type_ = u;
  if (u)
    set_size_in_bits(u->get_size_in_bits());
}

/// Getter of the upper bound of the subrange type.
///
/// @return the upper bound of the subrange type.
int64_t
array_type_def::subrange_type::get_upper_bound() const
{return priv_->upper_bound_.get_signed_value();}

/// Getter of the lower bound of the subrange type.
///
/// @return the lower bound of the subrange type.
int64_t
array_type_def::subrange_type::get_lower_bound() const
{return priv_->lower_bound_.get_signed_value();}

/// Setter of the upper bound of the subrange type.
///
/// @param ub the new value of the upper bound.
void
array_type_def::subrange_type::set_upper_bound(int64_t ub)
{priv_->upper_bound_ = ub;}

/// Setter of the lower bound.
///
/// @param lb the new value of the lower bound.
void
array_type_def::subrange_type::set_lower_bound(int64_t lb)
{priv_->lower_bound_ = lb;}

/// Getter of the length of the subrange type.
///
/// Note that a length of zero means the array has an infinite (or
/// rather a non-known) size.
///
/// @return the length of the subrange type.
uint64_t
array_type_def::subrange_type::get_length() const
{
  if (is_non_finite())
    return 0;

  // A subrange can have an upper bound that is lower than its lower
  // bound.  This is possible in Ada for instance.  In that case, the
  // length of the subrange is considered to be zero.
  if (get_upper_bound() >= get_lower_bound())
    return get_upper_bound() - get_lower_bound() + 1;
  return 0;
}

/// Test if the length of the subrange type is infinite.
///
/// @return true iff the length of the subrange type is infinite.
bool
array_type_def::subrange_type::is_non_finite() const
{return priv_->infinite_;}

/// Set the infinite-ness status of the subrange type.
///
/// @param f true iff the length of the subrange type should be set to
/// being infinite.
void
array_type_def::subrange_type::is_non_finite(bool f)
{priv_->infinite_ = f;}

/// Getter of the language that generated this type.
///
/// @return the language of this type.
translation_unit::language
array_type_def::subrange_type::get_language() const
{return priv_->language_;}

/// Return a string representation of the sub range.
///
/// @return the string representation of the sub range.
string
array_type_def::subrange_type::as_string() const
{
  std::ostringstream o;

  if (is_ada_language(get_language()))
    {
      type_base_sptr underlying_type = get_underlying_type();
      if (underlying_type)
    o << ir::get_pretty_representation(underlying_type, false) << " ";
      o << "range "<< get_lower_bound() << " .. " << get_upper_bound();
    }
  else if (is_non_finite())
    o << "[]";
  else
    o << "["  << get_length() << "]";

  return o.str();
}

/// Return a string representation of a vector of subranges
///
/// @return the string representation of a vector of sub ranges.
string
array_type_def::subrange_type::vector_as_string(const vector<subrange_sptr>& v)
{
  if (v.empty())
    return "[]";

  string r;
  for (vector<subrange_sptr>::const_iterator i = v.begin();
       i != v.end();
       ++i)
    r += (*i)->as_string();

  return r;
}

/// Compares two isntances of @ref array_type_def::subrange_type.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const array_type_def::subrange_type& l,
       const array_type_def::subrange_type& r,
       change_kind* k)
{
  bool result = true;

  if (l.get_lower_bound() != r.get_lower_bound()
      || l.get_upper_bound() != r.get_upper_bound()
      || l.get_name() != r.get_name())
    {
      result = false;
      if (k)
    *k |= LOCAL_TYPE_CHANGE_KIND;
      else
    ABG_RETURN(result);
    }

  if (l.get_underlying_type()
      && r.get_underlying_type()
      && (*l.get_underlying_type() != *r.get_underlying_type()))
    {
      result = false;
      if (k)
    *k |= SUBTYPE_CHANGE_KIND;
      else
    ABG_RETURN(result);
    }

  ABG_RETURN(result);
}

/// Equality operator.
///
/// @param o the other subrange to test against.
///
/// @return true iff @p o equals the current instance of
/// array_type_def::subrange_type.
bool
array_type_def::subrange_type::operator==(const decl_base& o) const
{
  const subrange_type* other =
    dynamic_cast<const subrange_type*>(&o);
  if (!other)
    return false;
  return try_canonical_compare(this, other);
}

/// Equality operator.
///
/// @param o the other subrange to test against.
///
/// @return true iff @p o equals the current instance of
/// array_type_def::subrange_type.
bool
array_type_def::subrange_type::operator==(const type_base& o) const
{
  const decl_base* other = dynamic_cast<const decl_base*>(&o);
  if (!other)
    return false;
  return *this == *other;
}

/// Equality operator.
///
/// @param o the other subrange to test against.
///
/// @return true iff @p o equals the current instance of
/// array_type_def::subrange_type.
bool
array_type_def::subrange_type::operator==(const subrange_type& o) const
{
  const type_base &t = o;
  return operator==(t);
}

/// Equality operator.
///
/// @param o the other subrange to test against.
///
/// @return true iff @p o equals the current instance of
/// array_type_def::subrange_type.
bool
array_type_def::subrange_type::operator!=(const decl_base& o) const
{return !operator==(o);}

/// Equality operator.
///
/// @param o the other subrange to test against.
///
/// @return true iff @p o equals the current instance of
/// array_type_def::subrange_type.
bool
array_type_def::subrange_type::operator!=(const type_base& o) const
{return !operator==(o);}

/// Inequality operator.
///
/// @param o the other subrange to test against.
///
/// @return true iff @p o is different from the current instance of
/// array_type_def::subrange_type.
bool
array_type_def::subrange_type::operator!=(const subrange_type& o) const
{return !operator==(o);}

/// Build a pretty representation for an
/// array_type_def::subrange_type.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
///
/// @return a copy of the pretty representation of the current
/// instance of typedef_decl.
string
array_type_def::subrange_type::get_pretty_representation(bool, bool) const
{
  string name = get_name();
  string repr;

  if (name.empty())
    repr += "<anonymous range>";
  else
    repr += "<range " + get_name() + ">";
  repr += as_string();

  return repr;
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
array_type_def::subrange_type::traverse(ir_node_visitor& v)
{
  if (v.type_node_has_been_visited(this))
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      if (type_base_sptr u = get_underlying_type())
    u->traverse(v);
      visiting(false);
    }

  bool result = v.visit_end(this);
  v.mark_type_node_as_visited(this);
  return result;
}

// </array_type_def::subrange_type>

struct array_type_def::priv
{
  type_base_wptr    element_type_;
  subranges_type    subranges_;
  interned_string   temp_internal_qualified_name_;
  interned_string   internal_qualified_name_;

  priv(type_base_sptr t)
    : element_type_(t)
  {}

  priv(type_base_sptr t, subranges_type subs)
    : element_type_(t), subranges_(subs)
  {}

  priv()
  {}
};

/// Constructor for the type array_type_def
///
/// Note how the constructor expects a vector of subrange
/// objects. Parsing of the array information always entails
/// parsing the subrange info as well, thus the class subrange_type
/// is defined inside class array_type_def and also parsed
/// simultaneously.
///
/// @param e_type the type of the elements contained in the array
///
/// @param subs a vector of the array's subranges(dimensions)
///
/// @param locus the source location of the array type definition.
array_type_def::array_type_def(const type_base_sptr         e_type,
                   const std::vector<subrange_sptr>&    subs,
                   const location&              locus)
  : type_or_decl_base(e_type->get_environment(),
              ARRAY_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    type_base(e_type->get_environment(), 0, e_type->get_alignment_in_bits()),
    decl_base(e_type->get_environment(), locus),
    priv_(new priv(e_type))
{
  runtime_type_instance(this);
  append_subranges(subs);
}

/// Constructor for the type array_type_def
///
/// This constructor builds a temporary array that has no element type
/// associated.  Later when the element type is available, it be set
/// with the array_type_def::set_element_type() member function.
///
/// Note how the constructor expects a vector of subrange
/// objects. Parsing of the array information always entails
/// parsing the subrange info as well, thus the class subrange_type
/// is defined inside class array_type_def and also parsed
/// simultaneously.
///
/// @param env the environment of the array type.
///
/// @param subs a vector of the array's subranges(dimensions)
///
/// @param locus the source location of the array type definition.
array_type_def::array_type_def(const environment&               env,
                   const std::vector<subrange_sptr>&    subs,
                   const location&              locus)
  : type_or_decl_base(env,
              ARRAY_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    type_base(env, 0, 0),
    decl_base(env, locus),
    priv_(new priv)
{
  runtime_type_instance(this);
  append_subranges(subs);
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
array_type_def::hash_value() const
{
  hash_t h = set_or_get_cached_hash_value(this);
  return h;
}

/// Update the size of the array.
///
/// This function computes the size of the array and sets it using
/// type_base::set_size_in_bits().
void
array_type_def::update_size()
{
  type_base_sptr e = priv_->element_type_.lock();
  if (e)
    {
      size_t s = e->get_size_in_bits();
      if (s)
    {
      for (const auto &sub : get_subranges())
        s *= sub->get_length();
      set_size_in_bits(s);
    }
      set_alignment_in_bits(e->get_alignment_in_bits());
    }
}

string
array_type_def::get_subrange_representation() const
{
  string r = subrange_type::vector_as_string(get_subranges());
  return r;
}

/// Get the pretty representation of the current instance of @ref
/// array_type_def.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the pretty representation of the ABI artifact.
string
array_type_def::get_pretty_representation(bool internal,
                      bool qualified_name) const
{
  return array_declaration_name(this, /*variable_name=*/"",
                qualified_name, internal);
}

/// Compares two instances of @ref array_type_def.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const array_type_def& l, const array_type_def& r, change_kind* k)
{
  std::vector<array_type_def::subrange_sptr > this_subs = l.get_subranges();
  std::vector<array_type_def::subrange_sptr > other_subs = r.get_subranges();

  bool result = true;
  if (this_subs.size() != other_subs.size())
    {
      result = false;
      if (k)
    *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }

  std::vector<array_type_def::subrange_sptr >::const_iterator i,j;
  for (i = this_subs.begin(), j = other_subs.begin();
       i != this_subs.end() && j != other_subs.end();
       ++i, ++j)
    if (**i != **j)
      {
    result = false;
    if (k)
      {
        *k |= LOCAL_NON_TYPE_CHANGE_KIND;
        break;
      }
    else
      ABG_RETURN_FALSE;
      }

  // Compare the element types modulo the typedefs they might have
  if (l.get_element_type() != r.get_element_type())
    {
      result = false;
      if (k)
    *k |= SUBTYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }

  ABG_RETURN(result);
}

/// Test if two array types are equals modulo CV qualifiers.
///
/// @param l the first array of the comparison.
///
/// @param r the second array of the comparison.
///
/// @return true iff @p l equals @p r or, if they are different, the
/// difference between the too is just a matter of CV qualifiers.
bool
equals_modulo_cv_qualifier(const array_type_def* l, const array_type_def* r)
{
  if (l == r)
    return true;

  if (!l || !r)
    ABG_RETURN_FALSE;

  l = is_array_type(peel_qualified_or_typedef_type(l));
  r = is_array_type(peel_qualified_or_typedef_type(r));

  std::vector<array_type_def::subrange_sptr > this_subs = l->get_subranges();
  std::vector<array_type_def::subrange_sptr > other_subs = r->get_subranges();

  if (this_subs.size() != other_subs.size())
    ABG_RETURN_FALSE;

  std::vector<array_type_def::subrange_sptr >::const_iterator i,j;
  for (i = this_subs.begin(), j = other_subs.begin();
       i != this_subs.end() && j != other_subs.end();
       ++i, ++j)
    if (**i != **j)
      ABG_RETURN_FALSE;

  type_base *first_element_type =
    peel_qualified_or_typedef_type(l->get_element_type().get());
  type_base *second_element_type =
    peel_qualified_or_typedef_type(r->get_element_type().get());

  if (*first_element_type != *second_element_type)
    ABG_RETURN_FALSE;

  return true;
}

/// Test if two array types are equals modulo CV qualifiers.
///
/// @param l the first array of the comparison.
///
/// @param r the second array of the comparison.
///
/// @return true iff @p l equals @p r or, if they are different, the
/// difference between the too is just a matter of CV qualifiers.
bool
equals_modulo_cv_qualifier(const array_type_def_sptr& l,
               const array_type_def_sptr& r)
{return equals_modulo_cv_qualifier(l.get(), r.get());}

/// Test if two pointer types are equals modulo CV qualifiers.
///
/// @param l the first pointer of the comparison.
///
/// @param r the second pointer of the comparison.
///
/// @return true iff @p l equals @p r or, if they are different, the
/// difference between the too is just a matter of CV qualifiers.
bool
equals_modulo_cv_qualifier(const pointer_type_def* l, const pointer_type_def* r)
{
  if (l == r)
    return true;

  if (!l || !r)
    ABG_RETURN_FALSE;

  type_base_sptr l_ptt = l->get_pointed_to_type(),
    r_ptt = r->get_pointed_to_type();

  do
    {
      l_ptt = peel_qualified_or_typedef_type(l_ptt);
      r_ptt = peel_qualified_or_typedef_type(r_ptt);

      l_ptt = is_pointer_type(l_ptt)
    ? is_pointer_type(l_ptt)->get_pointed_to_type()
    : l_ptt;

      r_ptt = is_pointer_type(r_ptt)
    ? is_pointer_type(r_ptt)->get_pointed_to_type()
    : r_ptt;
    } while (is_pointer_type(l_ptt) && is_pointer_type(r_ptt));

  l_ptt = peel_qualified_or_typedef_type(l_ptt);
  r_ptt = peel_qualified_or_typedef_type(r_ptt);

  return *l_ptt == *r_ptt;
}

/// Test if two pointer types are equals modulo CV qualifiers.
///
/// @param l the first pointer of the comparison.
///
/// @param r the second pointer of the comparison.
///
/// @return true iff @p l equals @p r or, if they are different, the
/// difference between the too is just a matter of CV qualifiers.
bool
equals_modulo_cv_qualifier(const pointer_type_def_sptr& l,
               const pointer_type_def_sptr& r)
{return equals_modulo_cv_qualifier(l.get(), r.get());}

/// Get the language of the array.
///
/// @return the language of the array.
translation_unit::language
array_type_def::get_language() const
{
  const std::vector<subrange_sptr>& subranges =
    get_subranges();

  if (subranges.empty())
    return translation_unit::LANG_C11;
  return subranges.front()->get_language();
}

bool
array_type_def::operator==(const decl_base& o) const
{
  const array_type_def* other =
    dynamic_cast<const array_type_def*>(&o);
  if (!other)
    return false;
  return try_canonical_compare(this, other);
}

bool
array_type_def::operator==(const type_base& o) const
{
  const decl_base* other = dynamic_cast<const decl_base*>(&o);
  if (!other)
    return false;
  return *this == *other;
}

/// Getter of the type of an array element.
///
/// @return the type of an array element.
const type_base_sptr
array_type_def::get_element_type() const
{return priv_->element_type_.lock();}

/// Setter of the type of array element.
///
/// Beware that after using this function, one might want to
/// re-compute the canonical type of the array, if one has already
/// been computed.
///
/// The intended use of this method is to permit in-place adjustment
/// of the element type's qualifiers. In particular, the size of the
/// element type should not be changed.
///
/// @param element_type the new element type to set.
void
array_type_def::set_element_type(const type_base_sptr& element_type)
{
  priv_->element_type_ = element_type;
  update_size();
  set_name(get_environment().intern(get_pretty_representation()));
}

/// Append subranges from the vector @param subs to the current
/// vector of subranges.
void
array_type_def::append_subranges(const std::vector<subrange_sptr>& subs)
{

  for (const auto &sub : subs)
    priv_->subranges_.push_back(sub);

  update_size();
  set_name(get_environment().intern(get_pretty_representation()));
}

/// @return true if one of the sub-ranges of the array is infinite, or
/// if the array has no sub-range at all, also meaning that the size
/// of the array is infinite.
bool
array_type_def::is_non_finite() const
{
  if (priv_->subranges_.empty())
    return true;

  for (std::vector<shared_ptr<subrange_type> >::const_iterator i =
     priv_->subranges_.begin();
       i != priv_->subranges_.end();
       ++i)
    if ((*i)->is_non_finite())
      return true;

  return false;
}

int
array_type_def::get_dimension_count() const
{return priv_->subranges_.size();}

/// Build and return the qualified name of the current instance of the
/// @ref array_type_def.
///
/// @param qn output parameter.  Is set to the newly-built qualified
/// name of the current instance of @ref array_type_def.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
void
array_type_def::get_qualified_name(interned_string& qn, bool internal) const
{qn = get_qualified_name(internal);}

/// Compute the qualified name of the array.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the resulting qualified name.
const interned_string&
array_type_def::get_qualified_name(bool internal) const
{
  if (internal)
    {
      if (get_canonical_type())
    {
      if (priv_->internal_qualified_name_.empty())
        priv_->internal_qualified_name_ =
          array_declaration_name(this, /*variable_name=*/"",
                     /*qualified=*/false,
                     /*internal=*/true);
      return priv_->internal_qualified_name_;
    }
      else
    {
      priv_->temp_internal_qualified_name_ =
        array_declaration_name(this, /*variable_name=*/"",
                   /*qualified*/false, /*internal*/true);
      return priv_->temp_internal_qualified_name_;
    }
    }
  else
    {
      if (get_canonical_type())
    {
      if (decl_base::peek_qualified_name().empty())
        set_qualified_name(array_declaration_name(this,
                              /*variable_name=*/"",
                              /*qualified=*/false,
                              /*internal=*/false));
      return decl_base::peek_qualified_name();
    }
      else
    {
      set_temporary_qualified_name
        (array_declaration_name(this, /*variable_name=*/"",
                    /*qualified=*/false,
                    /*internal=*/false));
      return decl_base::peek_temporary_qualified_name();
    }
    }
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
array_type_def::traverse(ir_node_visitor& v)
{
  if (v.type_node_has_been_visited(this))
    return true;

  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      if (type_base_sptr t = get_element_type())
    t->traverse(v);
      visiting(false);
    }

  bool result = v.visit_end(this);
  v.mark_type_node_as_visited(this);
  return result;
}

const location&
array_type_def::get_location() const
{return decl_base::get_location();}

/// Get the array's subranges
const std::vector<array_type_def::subrange_sptr>&
array_type_def::get_subranges() const
{return priv_->subranges_;}

array_type_def::~array_type_def()
{}

// </array_type_def definitions>

// <enum_type_decl definitions>

class enum_type_decl::priv
{
  type_base_sptr    underlying_type_;
  enumerators       enumerators_;
  mutable enumerators   sorted_enumerators_;

  friend class enum_type_decl;

  priv();

public:
  priv(type_base_sptr underlying_type,
       enumerators& enumerators)
    : underlying_type_(underlying_type),
      enumerators_(enumerators)
  {}
}; // end class enum_type_decl::priv

/// Constructor.
///
/// @param name the name of the type declaration.
///
/// @param locus the source location where the type was defined.
///
/// @param underlying_type the underlying type of the enum.
///
/// @param enums the enumerators of this enum type.
///
/// @param linkage_name the linkage name of the enum.
///
/// @param vis the visibility of the enum type.
enum_type_decl::enum_type_decl(const string&    name,
                   const location&  locus,
                   type_base_sptr   underlying_type,
                   enumerators& enums,
                   const string&    linkage_name,
                   visibility   vis)
  : type_or_decl_base(underlying_type->get_environment(),
              ENUM_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    type_base(underlying_type->get_environment(),
          underlying_type->get_size_in_bits(),
          underlying_type->get_alignment_in_bits()),
    decl_base(underlying_type->get_environment(),
          name, locus, linkage_name, vis),
    priv_(new priv(underlying_type, enums))
{
  runtime_type_instance(this);
  for (enumerators::iterator e = get_enumerators().begin();
       e != get_enumerators().end();
       ++e)
    e->set_enum_type(this);
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
enum_type_decl::hash_value() const
{
  hash_t h = set_or_get_cached_hash_value(this);
  return h;
}

/// Return the underlying type of the enum.
type_base_sptr
enum_type_decl::get_underlying_type() const
{return priv_->underlying_type_;}

/// @return the list of enumerators of the enum.
const enum_type_decl::enumerators&
enum_type_decl::get_enumerators() const
{return priv_->enumerators_;}

/// @return the list of enumerators of the enum.
enum_type_decl::enumerators&
enum_type_decl::get_enumerators()
{return priv_->enumerators_;}

/// Get the lexicographically sorted vector of enumerators.
///
/// @return the lexicographically sorted vector of enumerators.
const enum_type_decl::enumerators&
enum_type_decl::get_sorted_enumerators() const
{
  if (priv_->sorted_enumerators_.empty())
    {
      for (auto e = get_enumerators().rbegin();
       e != get_enumerators().rend();
       ++e)
    priv_->sorted_enumerators_.push_back(*e);

      std::sort(priv_->sorted_enumerators_.begin(),
        priv_->sorted_enumerators_.end(),
        [](const enum_type_decl::enumerator& l,
           const enum_type_decl::enumerator& r)
        {
          if (l.get_name() == r.get_name())
            return l.get_value() < r.get_value();
          return (l.get_name() < r.get_name());
        });
    }

  return priv_->sorted_enumerators_;
}

/// Find an enumerator by its value.
///
/// @param value the enumerator value to look for.
///
/// @param result output parameter.  This is set to the enumerator
/// which value is @p value, if found.  This is set iff the function
/// returns true.
///
/// @return true iff an enumerator with value @p value was found and
/// returned by argument via @p result.
bool
enum_type_decl::find_enumerator_by_value(int64_t value,
                     enum_type_decl:: enumerator& result)
{
  for (auto& e : get_enumerators())
    if (e.get_value() == value)
      {
    result = e;
    return true;
      }

  return false;
}

/// Find an enumerator by its name
///
/// @param name the enumerator name to look for.
///
/// @param result output parameter.  This is set to the enumerator
/// which name is @p name, if found.  This is set iff the function
/// returns true.
///
/// @return true iff an enumerator with name @p name was found and
/// returned by argument via @p result.
bool
enum_type_decl::find_enumerator_by_name(const string& name,
                    enum_type_decl::enumerator& result)
{
  for (auto& e : get_enumerators())
    if (e.get_name() == name)
      {
    result = e;
    return true;
      }

  return false;
}

/// Get the pretty representation of the current instance of @ref
/// enum_type_decl.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
///
/// @param qualified_name if true, names emitted in the pretty
/// representation are fully qualified.
///
/// @return the pretty representation of the enum type.
string
enum_type_decl::get_pretty_representation(bool internal,
                      bool qualified_name) const
{
  string r = "enum ";

  if (internal && get_is_anonymous())
    r += get_type_name(this, qualified_name, /*internal=*/true);
  else if (get_is_anonymous())
    r += get_enum_flat_representation(*this, "",
                      /*one_line=*/true,
                      qualified_name);
  else
    r += decl_base::get_pretty_representation(internal,
                          qualified_name);
  return r;
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
enum_type_decl::traverse(ir_node_visitor &v)
{
  if (v.type_node_has_been_visited(this))
    return true;

  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      if (type_base_sptr t = get_underlying_type())
    t->traverse(v);
      visiting(false);
    }

  bool result = v.visit_end(this);
  v.mark_type_node_as_visited(this);
  return result;
}

/// Destructor for the enum type declaration.
enum_type_decl::~enum_type_decl()
{}

/// Test if two enums differ, but not by a name change.
///
/// @param l the first enum to consider.
///
/// @param r the second enum to consider.
///
/// @return true iff @p l differs from @p r by anything but a name
/// change.
bool
enum_has_non_name_change(const enum_type_decl& l,
             const enum_type_decl& r,
             change_kind* k)
{
  bool result = false;
  if (*l.get_underlying_type() != *r.get_underlying_type())
    {
      result = true;
      if (k)
    *k |= SUBTYPE_CHANGE_KIND;
      else
    return true;
    }

  enum_type_decl::enumerators::const_iterator i, j;
  for (i = l.get_enumerators().begin(), j = r.get_enumerators().begin();
       i != l.get_enumerators().end() && j != r.get_enumerators().end();
       ++i, ++j)
    if (*i != *j)
      {
    result = true;
    if (k)
      {
        *k |= LOCAL_TYPE_CHANGE_KIND;
        break;
      }
    else
      return true;
      }

  if (i != l.get_enumerators().end() || j != r.get_enumerators().end())
    {
      result = true;
      if (k)
    *k |= LOCAL_TYPE_CHANGE_KIND;
      else
    return true;
    }

  enum_type_decl &local_r = const_cast<enum_type_decl&>(r);
  interned_string qn_r = l.get_environment().intern(r.get_qualified_name());
  interned_string qn_l = l.get_environment().intern(l.get_qualified_name());
  string n_l = l.get_name();
  string n_r = r.get_name();
  local_r.set_qualified_name(qn_l);
  local_r.set_name(n_l);

  if (!(l.decl_base::operator==(r) && l.type_base::operator==(r)))
    {
      result = true;
      if (k)
    {
      if (!l.decl_base::operator==(r))
        *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      if (!l.type_base::operator==(r))
        *k |= LOCAL_TYPE_CHANGE_KIND;
    }
      else
    {
      local_r.set_name(n_r);
      local_r.set_qualified_name(qn_r);
      return true;
    }
    }
  local_r.set_qualified_name(qn_r);
  local_r.set_name(n_r);

  return result;
}

/// Test if a given enumerator is found present in an enum.
///
/// This is a subroutine of the equals function for enums.
///
/// @param enr the enumerator to consider.
///
/// @param enom the enum to consider.
///
/// @return true iff the enumerator @p enr is present in the enum @p
/// enom.
bool
is_enumerator_present_in_enum(const enum_type_decl::enumerator &enr,
                  const enum_type_decl &enom)
{
  for (const auto &e : enom.get_enumerators())
    if (e == enr)
      return true;
  return false;
}

/// Check if two enumerators values are equal.
///
/// This function doesn't check if the names of the enumerators are
/// equal or not.
///
/// @param enr the first enumerator to consider.
///
/// @param enl the second enumerator to consider.
///
/// @return true iff @p enr has the same value as @p enl.
static bool
enumerators_values_are_equal(const enum_type_decl::enumerator &enr,
                 const enum_type_decl::enumerator &enl)
{return enr.get_value() == enl.get_value();}

/// Detect if a given enumerator value is present in an enum.
///
/// This function looks inside the enumerators of a given enum and
/// detect if the enum contains at least one enumerator or a given
/// value.  The function also detects if the enumerator value we are
/// looking at is present in the enum with a different name.  An
/// enumerator with the same value but with a different name is named
/// a "redundant enumerator".  The function returns the set of
/// enumerators that are redundant with the value we are looking at.
///
/// @param enr the enumerator to consider.
///
/// @param enom the enum to consider.
///
/// @param redundant_enrs if the function returns true, then this
/// vector is filled with enumerators that are redundant with the
/// value of @p enr.
///
/// @return true iff the function detects that @p enom contains
/// enumerators with the same value as @p enr.
static bool
is_enumerator_value_present_in_enum(const enum_type_decl::enumerator &enr,
                    const enum_type_decl &enom,
                    vector<enum_type_decl::enumerator>& redundant_enrs)
{
  bool found = false;
  for (const auto &e : enom.get_enumerators())
    if (enumerators_values_are_equal(e, enr))
      {
    found = true;
    if (e != enr)
      redundant_enrs.push_back(e);
      }

  return found;
}

/// Check if an enumerator value is redundant in a given enum.
///
/// Given an enumerator value, this function detects if an enum
/// contains at least one enumerator with the the same value but with
/// a different name.
///
/// @param enr the enumerator to consider.
///
/// @param enom the enum to consider.
///
/// @return true iff @p enr is a redundant enumerator in enom.
static bool
is_enumerator_value_redundant(const enum_type_decl::enumerator &enr,
                  const enum_type_decl &enom)
{
  vector<enum_type_decl::enumerator> redundant_enrs;
  if (is_enumerator_value_present_in_enum(enr, enom, redundant_enrs))
    {
      if (!redundant_enrs.empty())
    return true;
    }
    return false;
}

/// Compares two instances of @ref enum_type_decl.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const enum_type_decl& l, const enum_type_decl& r, change_kind* k)
{
  bool result = true;

  //
  // Look through decl-only-enum.
  //

  const enum_type_decl *def1 =
    l.get_is_declaration_only()
    ? is_enum_type(l.get_naked_definition_of_declaration())
    : &l;

  const enum_type_decl *def2 =
    r.get_is_declaration_only()
    ? is_enum_type(r.get_naked_definition_of_declaration())
    : &r;

  if (!!def1 != !!def2)
    {
      // One enum is decl-only while the other is not.
      // So the two enums are different.
      result = false;
      if (k)
    *k |= SUBTYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }

  //
  // At this point, both enums have the same state of decl-only-ness.
  // So we can compare oranges to oranges.
  //

  if (!def1)
    def1 = &l;
  if (!def2)
    def2 = &r;

  if (def1->get_underlying_type() != def2->get_underlying_type())
    {
      result = false;
      if (k)
    *k |= SUBTYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }

  if (!(def1->decl_base::operator==(*def2)
    && def1->type_base::operator==(*def2)))
    {
      result = false;
      if (k)
    {
      if (!def1->decl_base::operator==(*def2))
        *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      if (!def1->type_base::operator==(*def2))
        *k |= LOCAL_TYPE_CHANGE_KIND;
    }
      else
    ABG_RETURN_FALSE;
    }

  // Now compare the enumerators.

  // First in a naive (but potentially fast) way in case both enums
  // are equal in a naive manner.

  if (def1->get_enumerators().size() == def2->get_enumerators().size())
    {
      bool equals = true;
      for (auto e1 = def1->get_enumerators().begin(),
         e2 = def2->get_enumerators().begin();
       (e1 != def1->get_enumerators().end()
        &&  e2 != def2->get_enumerators().end());
       ++e1, ++e2)
    {
      if (*e1 != *e2)
        {
          equals = false;
          break;
        }
    }
      if (equals)
    ABG_RETURN(result);
    }

  // If the two enums where not naively equals, let's try a more
  // clever (and slow) way.

  // Note that the order of declaration
  // of enumerators should not matter in the comparison.
  //
  // Also if an enumerator value is redundant, that shouldn't impact
  // the comparison.
  //
  // In that case, note that the two enums below are considered equal:
  //
  // enum foo
  //     {
  //       e0 = 0;
  //       e1 = 1;
  //       e2 = 2;
  //     };
  //
  //     enum foo
  //     {
  //       e0 = 0;
  //       e1 = 1;
  //       e2 = 2;
  //       e_added = 1; // <-- this value is redundant with the value
  //                    //     of the enumerator e1.
  //     };
  //
  //     Note however that in the case below, the enums are different.
  //
  // enum foo
  // {
  //   e0 = 0;
  //   e1 = 1;
  // };
  //
  // enum foo
  // {
  //   e0 = 0;
  //   e2 = 1;  // <-- this enum value is present in the first version
  //            // of foo, but is not redundant with any enumerator
  //            // in the second version of of enum foo.
  // };
  //
  // These two enums are considered equal.

  for(const auto &e : def1->get_enumerators())
    if (!is_enumerator_present_in_enum(e, *def2)
    && (!is_enumerator_value_redundant(e, *def2)
        || !is_enumerator_value_redundant(e, *def1)))
      {
    result = false;
    if (k)
      {
        *k |= LOCAL_TYPE_CHANGE_KIND;
        break;
      }
    else
      ABG_RETURN_FALSE;
      }

  for(const auto &e : def2->get_enumerators())
    if (!is_enumerator_present_in_enum(e, *def1)
    && (!is_enumerator_value_redundant(e, *def1)
        || !is_enumerator_value_redundant(e, *def2)))
      {
    result = false;
    if (k)
      {
        *k |= LOCAL_TYPE_CHANGE_KIND;
        break;
      }
    else
      ABG_RETURN_FALSE;
      }

  ABG_RETURN(result);
}

/// Equality operator.
///
/// @param o the other enum to test against.
///
/// @return true iff @p o equals the current instance of enum type
/// decl.
bool
enum_type_decl::operator==(const decl_base& o) const
{
  const enum_type_decl* op = dynamic_cast<const enum_type_decl*>(&o);
  if (!op)
    return false;
  return try_canonical_compare(this, op);
}

/// Equality operator.
///
/// @param o the other enum to test against.
///
/// @return true iff @p o is equals the current instance of enum type
/// decl.
bool
enum_type_decl::operator==(const type_base& o) const
{
  const decl_base* other = dynamic_cast<const decl_base*>(&o);
  if (!other)
    return false;
  return *this == *other;
}

/// Equality operator for @ref enum_type_decl_sptr.
///
/// @param l the first operand to compare.
///
/// @param r the second operand to compare.
///
/// @return true iff @p l equals @p r.
bool
operator==(const enum_type_decl_sptr& l, const enum_type_decl_sptr& r)
{
  if (!!l != !!r)
    return false;
  if (l.get() == r.get())
    return true;
  decl_base_sptr o = r;
  return *l == *o;
}

/// Inequality operator for @ref enum_type_decl_sptr.
///
/// @param l the first operand to compare.
///
/// @param r the second operand to compare.
///
/// @return true iff @p l equals @p r.
bool
operator!=(const enum_type_decl_sptr& l, const enum_type_decl_sptr& r)
{return !operator==(l, r);}

/// The type of the private data of an @ref
/// enum_type_decl::enumerator.
class enum_type_decl::enumerator::priv
{
  string        name_;
  int64_t       value_;
  string        qualified_name_;
  enum_type_decl*   enum_type_;

  friend class  enum_type_decl::enumerator;

public:

  priv()
    : enum_type_()
  {}

  priv(const string& name,
       int64_t value,
       enum_type_decl* e = 0)
    : name_(name),
      value_(value),
      enum_type_(e)
  {}
}; // end class enum_type_def::enumerator::priv

/// Default constructor of the @ref enum_type_decl::enumerator type.
enum_type_decl::enumerator::enumerator()
  : priv_(new priv)
{}

enum_type_decl::enumerator::~enumerator() = default;

/// Constructor of the @ref enum_type_decl::enumerator type.
///
/// @param env the environment we are operating from.
///
/// @param name the name of the enumerator.
///
/// @param value the value of the enumerator.
enum_type_decl::enumerator::enumerator(const string& name,
                       int64_t value)
  : priv_(new priv(name, value))
{}

/// Copy constructor of the @ref enum_type_decl::enumerator type.
///
/// @param other enumerator to copy.
enum_type_decl::enumerator::enumerator(const enumerator& other)
  : priv_(new priv(other.get_name(),
           other.get_value(),
           other.get_enum_type()))
{}

/// Assignment operator of the @ref enum_type_decl::enumerator type.
///
/// @param o
enum_type_decl::enumerator&
enum_type_decl::enumerator::operator=(const enumerator& o)
{
  priv_->name_ = o.get_name();
  priv_->value_ = o.get_value();
  priv_->enum_type_ = o.get_enum_type();
  return *this;
}

/// Equality operator
///
/// @param other the enumerator to compare to the current
/// instance of enum_type_decl::enumerator.
///
/// @return true if @p other equals the current instance of
/// enum_type_decl::enumerator.
bool
enum_type_decl::enumerator::operator==(const enumerator& other) const
{
  bool names_equal = true;
  names_equal = (get_name() == other.get_name());
  return names_equal && (get_value() == other.get_value());
}

/// Inequality operator.
///
/// @param other the other instance to compare against.
///
/// @return true iff @p other is different from the current instance.
bool
enum_type_decl::enumerator::operator!=(const enumerator& other) const
{return !operator==(other);}

/// Getter for the name of the current instance of
/// enum_type_decl::enumerator.
///
/// @return a reference to the name of the current instance of
/// enum_type_decl::enumerator.
const string&
enum_type_decl::enumerator::get_name() const
{return priv_->name_;}

/// Getter for the qualified name of the current instance of
/// enum_type_decl::enumerator.  The first invocation of the method
/// builds the qualified name, caches it and return a reference to the
/// cached qualified name.  Subsequent invocations just return the
/// cached value.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @return the qualified name of the current instance of
/// enum_type_decl::enumerator.
const string&
enum_type_decl::enumerator::get_qualified_name(bool internal) const
{
  if (priv_->qualified_name_.empty())
    {
      priv_->qualified_name_ =
    get_enum_type()->get_qualified_name(internal)
    + "::"
    + get_name();
    }
  return priv_->qualified_name_;
}

/// Setter for the name of @ref enum_type_decl::enumerator.
///
/// @param n the new name.
void
enum_type_decl::enumerator::set_name(const string& n)
{priv_->name_ = n;}

/// Getter for the value of @ref enum_type_decl::enumerator.
///
/// @return the value of the current instance of
/// enum_type_decl::enumerator.
int64_t
enum_type_decl::enumerator::get_value() const
{return priv_->value_;}

/// Setter for the value of @ref enum_type_decl::enumerator.
///
/// @param v the new value of the enum_type_decl::enumerator.
void
enum_type_decl::enumerator::set_value(int64_t v)
{priv_->value_= v;}

/// Getter for the enum type that this enumerator is for.
///
/// @return the enum type that this enumerator is for.
enum_type_decl*
enum_type_decl::enumerator::get_enum_type() const
{return priv_->enum_type_;}

/// Setter for the enum type that this enumerator is for.
///
/// @param e the new enum type.
void
enum_type_decl::enumerator::set_enum_type(enum_type_decl* e)
{priv_->enum_type_ = e;}
// </enum_type_decl definitions>

// <typedef_decl definitions>

/// Private data structure of the @ref typedef_decl.
struct typedef_decl::priv
{
  type_base_wptr    underlying_type_;

  priv(const type_base_sptr& t)
    : underlying_type_(t)
  {}
}; // end struct typedef_decl::priv

/// Constructor of the typedef_decl type.
///
/// @param name the name of the typedef.
///
/// @param underlying_type the underlying type of the typedef.
///
/// @param locus the source location of the typedef declaration.
///
/// @param linkage_name the mangled name of the typedef.
///
/// @param vis the visibility of the typedef type.
typedef_decl::typedef_decl(const string&        name,
               const type_base_sptr underlying_type,
               const location&      locus,
               const string&        linkage_name,
               visibility vis)
  : type_or_decl_base(underlying_type->get_environment(),
              TYPEDEF_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    type_base(underlying_type->get_environment(),
          underlying_type->get_size_in_bits(),
          underlying_type->get_alignment_in_bits()),
    decl_base(underlying_type->get_environment(),
          name, locus, linkage_name, vis),
    priv_(new priv(underlying_type))
{
  runtime_type_instance(this);
}

/// Constructor of the typedef_decl type.
///
/// @param name the name of the typedef.
///
/// @param env the environment of the current typedef.
///
/// @param locus the source location of the typedef declaration.
///
/// @param mangled_name the mangled name of the typedef.
///
/// @param vis the visibility of the typedef type.
typedef_decl::typedef_decl(const string& name,
               const environment& env,
               const location& locus,
               const string& mangled_name,
               visibility vis)
  : type_or_decl_base(env,
              TYPEDEF_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    type_base(env, /*size_in_bits=*/0,
          /*alignment_in_bits=*/0),
    decl_base(env, name, locus, mangled_name, vis),
    priv_(new priv(nullptr))
{
  runtime_type_instance(this);
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
typedef_decl::hash_value() const
{
  hash_t h = set_or_get_cached_hash_value(this);
  return h;
}

/// Return the size of the typedef.
///
/// This function looks at the size of the underlying type and ensures
/// that it's the same as the size of the typedef.
///
/// @return the size of the typedef.
size_t
typedef_decl::get_size_in_bits() const
{
  if (!get_underlying_type())
    return 0;
  size_t s = get_underlying_type()->get_size_in_bits();
  if (s != type_base::get_size_in_bits())
    const_cast<typedef_decl*>(this)->set_size_in_bits(s);
  return type_base::get_size_in_bits();
}

/// Return the alignment of the typedef.
///
/// This function looks at the alignment of the underlying type and
/// ensures that it's the same as the alignment of the typedef.
///
/// @return the size of the typedef.
size_t
typedef_decl::get_alignment_in_bits() const
{
  if (!get_underlying_type())
    return 0;
  size_t s = get_underlying_type()->get_alignment_in_bits();
  if (s != type_base::get_alignment_in_bits())
    const_cast<typedef_decl*>(this)->set_alignment_in_bits(s);
  return type_base::get_alignment_in_bits();
}

/// Compares two instances of @ref typedef_decl.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const typedef_decl& l, const typedef_decl& r, change_kind* k)
{
  bool result = true;

  // No need to go further if the types have different names or
  // different size / alignment.
  if (!(l.decl_base::operator==(r)))
    {
      result = false;
      if (k)
    *k |= LOCAL_TYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }

  if (*l.get_underlying_type() != *r.get_underlying_type())
    {
      // Changes to the underlying type of a typedef are considered
      // local, a bit like for pointers.
      result = false;
      if (k)
    *k |= LOCAL_TYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }

  ABG_RETURN(result);
}

/// Equality operator
///
/// @param o the other typedef_decl to test against.
bool
typedef_decl::operator==(const decl_base& o) const
{
  const typedef_decl* other = dynamic_cast<const typedef_decl*>(&o);
  if (!other)
    return false;
  return try_canonical_compare(this, other);
}

/// Equality operator
///
/// @param o the other typedef_decl to test against.
///
/// @return true if the current instance of @ref typedef_decl equals
/// @p o.
bool
typedef_decl::operator==(const type_base& o) const
{
  const decl_base* other = dynamic_cast<const decl_base*>(&o);
  if (!other)
    return false;
  return *this == *other;
}

/// Build a pretty representation for a typedef_decl.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.

/// @param qualified_name if true, names emitted in the pretty
/// representation are fully qualified.
///
/// @return a copy of the pretty representation of the current
/// instance of typedef_decl.
string
typedef_decl::get_pretty_representation(bool internal,
                    bool qualified_name) const
{

  string result = "typedef ";
  if (qualified_name)
    result += get_qualified_name(internal);
  else
    result += get_name();

  return result;
}

/// Getter of the underlying type of the typedef.
///
/// @return the underlying_type.
type_base_sptr
typedef_decl::get_underlying_type() const
{return priv_->underlying_type_.lock();}

/// Setter ofthe underlying type of the typedef.
///
/// @param t the new underlying type of the typedef.
void
typedef_decl::set_underlying_type(const type_base_sptr& t)
{
  priv_->underlying_type_ = t;
  set_size_in_bits(t->get_size_in_bits());
  set_alignment_in_bits(t->get_alignment_in_bits());
}

/// Implementation of the virtual "get_qualified_name" method.
///
/// @param qualified_name the resuling qualified name of the typedef type.
///
/// @param internal if true, then it means the qualified name is for
/// "internal" purposes, meaning mainly for type canonicalization
/// purposes.
void
typedef_decl::get_qualified_name(interned_string& qualified_name,
                 bool internal) const
{qualified_name = get_qualified_name(internal);}

/// Implementation of the virtual "get_qualified_name" method.
///
/// @param internal if true, then it means the qualified name is for
/// "internal" purposes, meaning mainly for type canonicalization
/// purposes.
///
/// @return the qualified name.
const interned_string&
typedef_decl::get_qualified_name(bool internal) const
{
  // Note that the qualified name has been already set by
  // qualified_name_setter::do_update, which is invoked by
  // update_qualified_name.  The latter is itself invoked whenever the
  // typedef is added to its scope, in scope_decl::add_member_decl.
  if (internal)
    return decl_base::priv_->internal_qualified_name_;
  else
    return decl_base::priv_->qualified_name_;
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
typedef_decl::traverse(ir_node_visitor& v)
{
  if (v.type_node_has_been_visited(this))
    return true;

  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      if (type_base_sptr t = get_underlying_type())
    t->traverse(v);
      visiting(false);
    }

  bool result = v.visit_end(this);
  v.mark_type_node_as_visited(this);
  return result;
}

typedef_decl::~typedef_decl()
{}
// </typedef_decl definitions>

// <var_decl definitions>

struct var_decl::priv
{
  type_base_wptr    type_;
  type_base*        naked_type_;
  decl_base::binding    binding_;
  elf_symbol_sptr   symbol_;
  interned_string   id_;

  priv()
    : naked_type_(),
    binding_(decl_base::BINDING_GLOBAL)
  {}

  priv(type_base_sptr t,
       decl_base::binding b)
    : type_(t),
      naked_type_(t.get()),
      binding_(b)
  {}

  /// Setter of the type of the variable.
  ///
  /// @param t the new variable type.
  void
  set_type(type_base_sptr t)
  {
    type_ = t;
    naked_type_ = t.get();
  }
}; // end struct var_decl::priv

/// Constructor of the @ref var_decl type.
///
/// @param name the name of the variable declaration
///
/// @param type the type of the variable declaration
///
/// @param locus the source location where the variable was defined.
///
/// @param linkage_name the linkage name of the variable.
///
/// @param vis the visibility of of the variable.
///
/// @param bind the binding kind of the variable.
var_decl::var_decl(const string&    name,
           type_base_sptr   type,
           const location&  locus,
           const string&    linkage_name,
           visibility       vis,
           binding      bind)
  : type_or_decl_base(type->get_environment(),
              VAR_DECL | ABSTRACT_DECL_BASE),
    decl_base(type->get_environment(), name, locus, linkage_name, vis),
    priv_(new priv(type, bind))
{
  runtime_type_instance(this);
}

/// Getter of the type of the variable.
///
/// @return the type of the variable.
const type_base_sptr
var_decl::get_type() const
{return priv_->type_.lock();}

/// Setter of the type of the variable.
///
/// @param the new type of the variable.
void
var_decl::set_type(type_base_sptr& t)
{priv_->set_type(t);}

/// Getter of the type of the variable.
///
/// This getter returns a bare pointer, as opposed to a smart pointer.
/// It's to be used on performance sensitive code paths identified by
/// careful profiling.
///
/// @return the type of the variable, as a bare pointer.
const type_base*
var_decl::get_naked_type() const
{return priv_->naked_type_;}

/// Getter of the binding of the variable.
///
/// @return the biding of the variable.
decl_base::binding
var_decl::get_binding() const
{return priv_->binding_;}

/// Setter of the binding of the variable.
///
/// @param b the new binding value.
void
var_decl::set_binding(decl_base::binding b)
{priv_->binding_ = b;}

/// Sets the underlying ELF symbol for the current variable.
///
/// And underlyin$g ELF symbol for the current variable might exist
/// only if the corpus that this variable originates from was
/// constructed from an ELF binary file.
///
/// Note that comparing two variables that have underlying ELF symbols
/// involves comparing their underlying elf symbols.  The decl name
/// for the variable thus becomes irrelevant in the comparison.
///
/// @param sym the new ELF symbol for this variable decl.
void
var_decl::set_symbol(const elf_symbol_sptr& sym)
{
  priv_->symbol_ = sym;
  // The variable id cache that depends on the symbol must be
  // invalidated because the symbol changed.
  priv_->id_ = get_environment().intern("");
}

/// Gets the the underlying ELF symbol for the current variable,
/// that was set using var_decl::set_symbol().  Please read the
/// documentation for that member function for more information about
/// "underlying ELF symbols".
///
/// @return sym the underlying ELF symbol for this variable decl, if
/// one exists.
const elf_symbol_sptr&
var_decl::get_symbol() const
{return priv_->symbol_;}

/// Create a new var_decl that is a clone of the current one.
///
/// @return the cloned var_decl.
var_decl_sptr
var_decl::clone() const
{
  var_decl_sptr v(new var_decl(get_name(),
                   get_type(),
                   get_location(),
                   get_linkage_name(),
                   get_visibility(),
                   get_binding()));

  v->set_symbol(get_symbol());

  if (is_member_decl(*this))
    {
      class_or_union* scope = is_class_or_union_type(get_scope());
      scope->add_data_member(v, get_member_access_specifier(*this),
                 get_data_member_is_laid_out(*this),
                 get_member_is_static(*this),
                 get_data_member_offset(*this));
    }
  else
    add_decl_to_scope(v, get_scope());

  return v;
}
/// Setter of the scope of the current var_decl.
///
/// Note that the decl won't hold a reference on the scope.  It's
/// rather the scope that holds a reference on its members.
///
/// @param scope the new scope.
void
var_decl::set_scope(scope_decl* scope)
{
  if (!get_context_rel())
    set_context_rel(new dm_context_rel(scope));
  else
    get_context_rel()->set_scope(scope);
}

/// Compares two instances of @ref var_decl without taking their type
/// into account.
///
/// If the two intances are different modulo their type, set a
/// bitfield to give some insight about the kind of differences there
/// are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
var_equals_modulo_types(const var_decl& l, const var_decl& r, change_kind* k)
{
  bool result = true;

  // If there are underlying elf symbols for these variables,
  // compare them.  And then compare the other parts.
  const elf_symbol_sptr &s0 = l.get_symbol(), &s1 = r.get_symbol();
  if (!!s0 != !!s1)
    {
      result = false;
      if (k)
    *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }
  else if (s0 && !textually_equals(*s0, *s1, k))
    {
      result = false;
      if (!k)
    ABG_RETURN_FALSE;
    }
  bool symbols_are_equal = (s0 && s1 && result);

  if (symbols_are_equal)
    {
      // The variables have underlying elf symbols that are equal, so
      // now, let's compare the decl_base part of the variables w/o
      // considering their decl names.
      const environment& env = l.get_environment();
      const interned_string n1 = l.get_qualified_name(), n2 = r.get_qualified_name();
      const_cast<var_decl&>(l).set_qualified_name(env.intern(""));
      const_cast<var_decl&>(r).set_qualified_name(env.intern(""));
      bool decl_bases_different = !l.decl_base::operator==(r);
      const_cast<var_decl&>(l).set_qualified_name(n1);
      const_cast<var_decl&>(r).set_qualified_name(n2);

      if (decl_bases_different)
    {
      result = false;
      if (k)
        *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
        ABG_RETURN_FALSE;
    }
    }
  else
    if (!l.decl_base::operator==(r))
      {
    result = false;
    if (k)
      *k |= LOCAL_NON_TYPE_CHANGE_KIND;
    else
      ABG_RETURN_FALSE;
      }

  const dm_context_rel* c0 =
    dynamic_cast<const dm_context_rel*>(l.get_context_rel());
  const dm_context_rel* c1 =
    dynamic_cast<const dm_context_rel*>(r.get_context_rel());
  ABG_ASSERT(c0 && c1);

  if (*c0 != *c1)
    {
      result = false;
      if (k)
    *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }

  ABG_RETURN(result);
}

/// Compares two instances of @ref var_decl.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const var_decl& l, const var_decl& r, change_kind* k)
{
  bool result = true;

  // First test types of variables.  This should be fast because in
  // the general case, most types should be canonicalized.
  if (*l.get_naked_type() != *r.get_naked_type())
    {
      result = false;
      if (k)
    {
      if (!types_have_similar_structure(l.get_naked_type(),
                        r.get_naked_type()))
        *k |= (LOCAL_TYPE_CHANGE_KIND);
      else
        *k |= SUBTYPE_CHANGE_KIND;
    }
      else
    ABG_RETURN_FALSE;
    }

  result &= var_equals_modulo_types(l, r, k);

  ABG_RETURN(result);
}

/// Comparison operator of @ref var_decl.
///
/// @param o the instance of @ref var_decl to compare against.
///
/// @return true iff the current instance of @ref var_decl equals @p o.
bool
var_decl::operator==(const decl_base& o) const
{
  const var_decl* other = dynamic_cast<const var_decl*>(&o);
  if (!other)
    return false;

  return equals(*this, *other, 0);
}

/// Return an ID that tries to uniquely identify the variable inside a
/// program or a library.
///
/// So if the variable has an underlying elf symbol, the ID is the
/// concatenation of the symbol name and its version.  Otherwise, the
/// ID is the linkage name if its non-null.  Otherwise, it's the
/// pretty representation of the variable.
///
/// @return the ID.
interned_string
var_decl::get_id() const
{
  if (priv_->id_.empty())
    {
      string repr = get_name();
      string sym_str;
      if (elf_symbol_sptr s = get_symbol())
    sym_str = s->get_id_string();
      else if (!get_linkage_name().empty())
    sym_str = get_linkage_name();

      const environment& env = get_type()->get_environment();
      priv_->id_ = env.intern(repr);
      if (!sym_str.empty())
    priv_->id_ = env.intern(priv_->id_ + "{" + sym_str + "}");
    }
  return priv_->id_;
}

/// Get the qualified name of a given variable or data member.
///
///
/// Note that if the current instance of @ref var_decl is an anonymous
/// data member, then the qualified name is actually the flat
/// representation (the definition) of the type of the anonymous data
/// member.  We chose the flat representation because otherwise, the
/// name of an *anonymous* data member is empty, by construction, e.g:
///
///   struct foo {
///     int a;
///     union {
///       char b;
///       char c;
///     }; // <---- this data member is anonymous.
///     int d;
///   }
///
///   The string returned for the anonymous member here is going to be:
///
///     "union {char b; char c}"
///
/// @param internal if true then this is for a purpose to the library,
/// otherwise, it's for being displayed to users.
///
/// @return the resulting qualified name.
const interned_string&
var_decl::get_qualified_name(bool internal) const
{
  if (is_anonymous_data_member(this)
      && decl_base::get_qualified_name().empty())
    {
      // Display the anonymous data member in a way that makes sense.
      string r = get_pretty_representation(internal);
      set_qualified_name(get_environment().intern(r));
    }

  return decl_base::get_qualified_name(internal);
}

/// Build and return the pretty representation of this variable.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
///
/// @param qualified_name if true, names emitted in the pretty
/// representation are fully qualified.
///
/// @return a copy of the pretty representation of this variable.
string
var_decl::get_pretty_representation(bool internal, bool qualified_name) const
{
  string result;

  if (is_member_decl(this) && get_member_is_static(this))
    result = "static ";

  // Detect if the current instance of var_decl is a member of
  // an anonymous class or union.
  bool member_of_anonymous_class = false;
  if (class_or_union* scope = is_at_class_scope(this))
    if (scope->get_is_anonymous())
      member_of_anonymous_class = true;

  type_base_sptr type = get_type();
  if (is_array_type(type, /*look_through_qualifiers=*/true)
      || is_pointer_type(type, /*look_through_qualifiers=*/true)
      || is_reference_type(type, /*look_through_qualifiers=*/true)
      || is_ptr_to_mbr_type(type, /*look_through_qualifiers=*/true))
    {
      string name;
      if (member_of_anonymous_class || !qualified_name)
    name = get_name();
      else
    name = get_qualified_name(internal);

      if (qualified_type_def_sptr q = is_qualified_type(type))
    {
      string quals_repr =
        get_string_representation_of_cv_quals(q->get_cv_quals());
      if (!quals_repr.empty())
        name = quals_repr + " " + name;
      type = peel_qualified_type(type);
    }

      name = string(" ") + name;
      if (array_type_def_sptr t = is_array_type(type))
    result += array_declaration_name(t, name, qualified_name, internal);
      else if (pointer_type_def_sptr t = is_pointer_type(type))
    result += pointer_declaration_name(t, name, qualified_name, internal);
      else if (reference_type_def_sptr t = is_reference_type(type))
    result += pointer_declaration_name(t, name, qualified_name, internal);
      else if (ptr_to_mbr_type_sptr t = is_ptr_to_mbr_type(type))
    result += ptr_to_mbr_declaration_name(t, name,
                          qualified_name,
                          internal);
    }
  else
    {
      if (/*The current var_decl is to be used as an anonymous data
        member.  */
      get_name().empty())
    {
      // Display the anonymous data member in a way that
      // makes sense.
      result +=
        get_class_or_union_flat_representation
        (is_class_or_union_type(get_type()),
         "", /*one_line=*/true, internal);
    }
      else if (data_member_has_anonymous_type(this))
    {
      result += get_class_or_union_flat_representation
        (is_class_or_union_type(get_type()),
         "", /*one_line=*/true, internal);
      result += " ";
      if (!internal
          && (member_of_anonymous_class || !qualified_name))
        // It doesn't make sense to name the member of an
        // anonymous class or union like:
        // "__anonymous__::data_member_name".  So let's just use
        // its non-qualified name.
        result += get_name();
      else
        result += get_qualified_name(internal);
    }
      else
    {
      result +=
        get_type_declaration(get_type())->get_qualified_name(internal)
        + " ";

      if (!internal
          && (member_of_anonymous_class || !qualified_name))
        // It doesn't make sense to name the member of an
        // anonymous class or union like:
        // "__anonymous__::data_member_name".  So let's just use
        // its non-qualified name.
        result += get_name();
      else
        result += get_qualified_name(internal);
    }
    }
  return result;
}

/// Get a name that is valid even for an anonymous data member.
///
/// If the current @ref var_decl is an anonymous data member, then
/// return its pretty representation. As of now, that pretty
/// representation is actually its flat representation as returned by
/// get_class_or_union_flat_representation().
///
/// Otherwise, just return the name of the current @ref var_decl.
///
/// @param qualified if true, return the qualified name.  This doesn't
/// have an effet if the current @ref var_decl represents an anonymous
/// data member.
string
var_decl::get_anon_dm_reliable_name(bool qualified) const
{
  string name;
  if (is_anonymous_data_member(this))
    // This function is used in the comparison engine to determine
    // which anonymous data member was deleted.  So it's not involved
    // in type comparison or canonicalization.  We don't want to use
    // the 'internal' version of the pretty presentation.
    name = get_pretty_representation(/*internal=*/false, qualified);
  else
    name = get_name();

  return name;
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
var_decl::traverse(ir_node_visitor& v)
{
  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      if (type_base_sptr t = get_type())
    t->traverse(v);
      visiting(false);
    }
  return v.visit_end(this);
}

var_decl::~var_decl()
{}

// </var_decl definitions>

/// This function is automatically invoked whenever an instance of
/// this type is canonicalized.
///
/// It's an overload of the virtual type_base::on_canonical_type_set.
///
/// We put here what is thus meant to be executed only at the point of
/// type canonicalization.
void
function_type::on_canonical_type_set()
{
  priv_->cached_name_.clear();
  priv_->internal_cached_name_.clear();
}

/// The most straightforward constructor for the function_type class.
///
/// @param return_type the return type of the function type.
///
/// @param parms the list of parameters of the function type.
/// Stricto sensu, we just need a list of types; we are using a list
/// of parameters (where each parameter also carries the name of the
/// parameter and its source location) to try and provide better
/// diagnostics whenever it makes sense.  If it appears that this
/// wasts too many resources, we can fall back to taking just a
/// vector of types here.
///
/// @param size_in_bits the size of this type, in bits.
///
/// @param alignment_in_bits the alignment of this type, in bits.
///
/// @param size_in_bits the size of this type.
function_type::function_type(type_base_sptr return_type,
                 const parameters&  parms,
                 size_t     size_in_bits,
                 size_t     alignment_in_bits)
  : type_or_decl_base(return_type->get_environment(),
              FUNCTION_TYPE | ABSTRACT_TYPE_BASE),
    type_base(return_type->get_environment(), size_in_bits, alignment_in_bits),
    priv_(new priv(parms, return_type))
{
  runtime_type_instance(this);

  for (parameters::size_type i = 0, j = 1;
       i < priv_->parms_.size();
       ++i, ++j)
    {
      if (i == 0 && priv_->parms_[i]->get_is_artificial())
    // If the first parameter is artificial, then it certainly
    // means that this is a member function, and the first
    // parameter is the implicit this pointer.  In that case, set
    // the index of that implicit parameter to zero.  Otherwise,
    // the index of the first parameter starts at one.
    j = 0;
      priv_->parms_[i]->set_index(j);
    }
}

/// A constructor for a function_type that takes no parameters.
///
/// @param return_type the return type of this function_type.
///
/// @param size_in_bits the size of this type, in bits.
///
/// @param alignment_in_bits the alignment of this type, in bits.
function_type::function_type(type_base_sptr return_type,
                 size_t size_in_bits, size_t alignment_in_bits)
  : type_or_decl_base(return_type->get_environment(),
              FUNCTION_TYPE | ABSTRACT_TYPE_BASE),
    type_base(return_type->get_environment(), size_in_bits, alignment_in_bits),
    priv_(new priv(return_type))
{
  runtime_type_instance(this);
}

/// A constructor for a function_type that takes no parameter and
/// that has no return_type yet.  These missing parts can (and must)
/// be added later.
///
/// @param env the environment we are operating from.
///
/// @param size_in_bits the size of this type, in bits.
///
/// @param alignment_in_bits the alignment of this type, in bits.
function_type::function_type(const environment& env,
                 size_t     size_in_bits,
                 size_t     alignment_in_bits)
  : type_or_decl_base(env, FUNCTION_TYPE | ABSTRACT_TYPE_BASE),
    type_base(env, size_in_bits, alignment_in_bits),
    priv_(new priv)
{
  runtime_type_instance(this);
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
function_type::hash_value() const
{
  hash_t h = set_or_get_cached_hash_value(this);
  return h;
}

/// Getter for the return type of the current instance of @ref
/// function_type.
///
/// @return the return type.
type_base_sptr
function_type::get_return_type() const
{return priv_->return_type_.lock();}

/// Setter of the return type of the current instance of @ref
/// function_type.
///
/// @param t the new return type to set.
void
function_type::set_return_type(type_base_sptr t)
{priv_->return_type_ = t;}

/// Getter for the set of parameters of the current intance of @ref
/// function_type.
///
/// @return the parameters of the current instance of @ref
/// function_type.
const function_decl::parameters&
function_type::get_parameters() const
{return priv_->parms_;}

/// Get the Ith parameter of the vector of parameters of the current
/// instance of @ref function_type.
///
/// Note that the first parameter is at index 0.  That parameter is
/// the first parameter that comes after the possible implicit "this"
/// parameter, when the current instance @ref function_type is for a
/// member function.  Otherwise, if the current instance of @ref
/// function_type is for a non-member function, the parameter at index
/// 0 is the first parameter of the function.
///
///
/// @param i the index of the parameter to return.  If i is greater
/// than the index of the last parameter, then this function returns
/// an empty parameter (smart) pointer.
///
/// @return the @p i th parameter that is not implicit.
const function_decl::parameter_sptr
function_type::get_parm_at_index_from_first_non_implicit_parm(size_t i) const
{
  parameter_sptr result;
  if (dynamic_cast<const method_type*>(this))
    {
      if (i + 1 < get_parameters().size())
    result = get_parameters()[i + 1];
    }
  else
    {
      if (i < get_parameters().size())
    result = get_parameters()[i];
    }
  return result;
}

/// Setter for the parameters of the current instance of @ref
/// function_type.
///
/// @param p the new vector of parameters to set.
void
function_type::set_parameters(const parameters &p)
{
  priv_->parms_ = p;
  for (parameters::size_type i = 0, j = 1;
       i < priv_->parms_.size();
       ++i, ++j)
    {
      if (i == 0 && priv_->parms_[i]->get_is_artificial())
    // If the first parameter is artificial, then it certainly
    // means that this is a member function, and the first
    // parameter is the implicit this pointer.  In that case, set
    // the index of that implicit parameter to zero.  Otherwise,
    // the index of the first parameter starts at one.
    j = 0;
      priv_->parms_[i]->set_index(j);
    }
}

/// Append a new parameter to the vector of parameters of the current
/// instance of @ref function_type.
///
/// @param parm the parameter to append.
void
function_type::append_parameter(parameter_sptr parm)
{
  parm->set_index(priv_->parms_.size());
  priv_->parms_.push_back(parm);
}

/// Test if the current instance of @ref function_type is for a
/// variadic function.
///
/// A variadic function is a function that takes a variable number of
/// arguments.
///
/// @return true iff the current instance of @ref function_type is for
/// a variadic function.
bool
function_type::is_variadic() const
{
  return (!priv_->parms_.empty()
     && priv_->parms_.back()->get_variadic_marker());
}

/// Compare two function types.
///
/// In case these function types are actually method types, this
/// function avoids comparing two parameters (of the function types)
/// if the types of the parameters are actually the types of the
/// classes of the method types.  This prevents infinite recursion
/// during the comparison of two classes that are structurally
/// identical.
///
/// This is a subroutine of the equality operator of function_type.
///
/// @param lhs the first function type to consider
///
/// @param rhs the second function type to consider
///
/// @param k a pointer to a bitfield set by the function to give
/// information about the kind of changes carried by @p lhs and @p
/// rhs.  It is set iff @p k is non-null and the function returns
/// false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
///@return true if lhs == rhs, false otherwise.
bool
equals(const function_type& l, const function_type& r, change_kind* k)
{
#define RETURN(value) CACHE_AND_RETURN_COMPARISON_RESULT(value)

  RETURN_TRUE_IF_COMPARISON_CYCLE_DETECTED(l, r);

  {
    // First of all, let's see if these two function types haven't
    // already been compared.  If so, and if the result of the
    // comparison has been cached, let's just re-use it, rather than
    // comparing them all over again.
    bool cached_result = false;
    if (l.get_environment().priv_->is_type_comparison_cached(l, r,
                                 cached_result))
      ABG_RETURN(cached_result);
  }

  mark_types_as_being_compared(l, r);

  bool result = true;

  if (!l.type_base::operator==(r))
    {
      result = false;
      if (k)
    *k |= LOCAL_TYPE_CHANGE_KIND;
      else
    RETURN(result);
    }

  class_or_union* l_class = 0, *r_class = 0;
  if (const method_type* m = dynamic_cast<const method_type*>(&l))
    l_class = m->get_class_type().get();

  if (const method_type* m = dynamic_cast<const method_type*>(&r))
    r_class = m->get_class_type().get();

  // Compare the names of the class of the method

  if (!!l_class != !!r_class)
    {
      result = false;
      if (k)
    *k |= LOCAL_TYPE_CHANGE_KIND;
      else
    RETURN(result);
    }
  else if (l_class
       && (l_class->get_qualified_name()
           != r_class->get_qualified_name()))
    {
      result = false;
      if (k)
    *k |= LOCAL_TYPE_CHANGE_KIND;
      else
    RETURN(result);
    }

  // Then compare the return type; Beware if it's t's a class type
  // that is the same as the method class name; we can recurse for
  // ever in that case.

  decl_base* l_return_type_decl =
    get_type_declaration(l.get_return_type()).get();
  decl_base* r_return_type_decl =
    get_type_declaration(r.get_return_type()).get();
  bool compare_result_types = true;
  string l_rt_name = l_return_type_decl
    ? l_return_type_decl->get_qualified_name()
    : string();
  string r_rt_name = r_return_type_decl
    ? r_return_type_decl->get_qualified_name()
    : string();

  if ((l_class && (l_class->get_qualified_name() == l_rt_name))
      ||
      (r_class && (r_class->get_qualified_name() == r_rt_name)))
    compare_result_types = false;

  if (compare_result_types)
    {
      // Let's not consider typedefs when comparing return types to
      // avoid spurious changes.
      //
      // TODO: We should also do this for parameter types, or rather,
      // we should teach the equality operators in the IR, at some
      // point, to peel typedefs off.
      if (l.get_return_type() != r.get_return_type())
    {
      result = false;
      if (k)
        {
          if (!types_have_similar_structure(l.get_return_type(),
                        r.get_return_type()))
        *k |= LOCAL_TYPE_CHANGE_KIND;
          else
        *k |= SUBTYPE_CHANGE_KIND;
        }
      else
        RETURN(result);
    }
    }
  else
    if (l_rt_name != r_rt_name)
      {
    result = false;
    if (k)
      *k |= SUBTYPE_CHANGE_KIND;
    else
      RETURN(result);
      }

  vector<shared_ptr<function_decl::parameter> >::const_iterator i,j;
  for (i = l.get_first_parm(), j = r.get_first_parm();
       i != l.get_parameters().end() && j != r.get_parameters().end();
       ++i, ++j)
    {
      if (**i != **j)
    {
      result = false;
      if (k)
        {
          if (!types_have_similar_structure((*i)->get_type(),
                        (*j)->get_type()))
        *k |= LOCAL_TYPE_CHANGE_KIND;
          else
        *k |= SUBTYPE_CHANGE_KIND;
        }
      else
        RETURN(result);
    }
    }

  if ((i != l.get_parameters().end()
       || j != r.get_parameters().end()))
    {
      result = false;
      if (k)
    *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
    RETURN(result);
    }

  RETURN(result);
#undef RETURN
}

/// Get the first parameter of the function.
///
/// If the function is a non-static member function, the parameter
/// returned is the first one following the implicit 'this' parameter.
///
/// @return the first non implicit parameter of the function.
function_type::parameters::const_iterator
function_type::get_first_non_implicit_parm() const
{
  if (get_parameters().empty())
    return get_parameters().end();

  bool is_method = dynamic_cast<const method_type*>(this);

  parameters::const_iterator i = get_parameters().begin();

  if (is_method && (*i)->get_is_artificial())
    ++i;

  return i;
}

/// Get the first parameter of the function.
///
/// Note that if the function is a non-static member function, the
/// parameter returned is the implicit 'this' parameter.
///
/// @return the first parameter of the function.
function_type::parameters::const_iterator
function_type::get_first_parm() const
{return get_parameters().begin();}

/// Get the name of the current @ref function_type.
///
/// The name is retrieved from a cache.  If the cache is empty, this
/// function computes the name of the type, stores it in the cache and
/// returns it.  Subsequent invocation of the function are going to
/// just hit the cache.
///
/// Note that if the type is *NOT* canonicalized then function type
/// name is never cached.
///
/// @param internal if true then it means the function type name is
/// going to be used for purposes that are internal to libabigail
/// itself.  If you don't know what this is then you probably should
/// set this parameter to 'false'.
///
/// @return the name of the function type.
const interned_string&
function_type::get_cached_name(bool internal) const
{
  if (internal)
    {
      if (get_naked_canonical_type())
    {
      if (priv_->internal_cached_name_.empty())
        priv_->internal_cached_name_ =
          get_function_type_name(this, /*internal=*/true);
      return priv_->internal_cached_name_;
    }
      else
    {
      priv_->temp_internal_cached_name_ =
        get_function_type_name(this, /*internal=*/true);
      return priv_->temp_internal_cached_name_;
    }
    }
  else
    {
      if (get_naked_canonical_type())
    {
      if (priv_->cached_name_.empty())
        priv_->cached_name_ =
          get_function_type_name(this, /*internal=*/false);
      return priv_->cached_name_;
    }
      else
    {
      priv_->cached_name_ =
        get_function_type_name(this, /*internal=*/false);
      return priv_->cached_name_;
    }
    }
}

/// Equality operator for function_type.
///
/// @param o the other function_type to compare against.
///
/// @return true iff the two function_type are equal.
bool
function_type::operator==(const type_base& other) const
{
  const function_type* o = dynamic_cast<const function_type*>(&other);
  if (!o)
    return false;
  return try_canonical_compare(this, o);
}

/// Return a copy of the pretty representation of the current @ref
/// function_type.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
///
/// @return a copy of the pretty representation of the current @ref
/// function_type.
string
function_type::get_pretty_representation(bool internal,
                     bool /*qualified_name*/) const
{return ir::get_pretty_representation(this, internal);}

/// Traverses an instance of @ref function_type, visiting all the
/// sub-types and decls that it might contain.
///
/// @param v the visitor that is used to visit every IR sub-node of
/// the current node.
///
/// @return true if either
///  - all the children nodes of the current IR node were traversed
///    and the calling code should keep going with the traversing.
///  - or the current IR node is already being traversed.
/// Otherwise, returning false means that the calling code should not
/// keep traversing the tree.
bool
function_type::traverse(ir_node_visitor& v)
{
  // TODO: should we allow the walker to avoid visiting function type
  // twice?  I think that if we do, then ir_node_visitor needs an
  // option to specifically disallow this feature for function types.

  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      bool keep_going = true;

      if (type_base_sptr t = get_return_type())
    {
      if (!t->traverse(v))
        keep_going = false;
    }

      if (keep_going)
    for (parameters::const_iterator i = get_parameters().begin();
         i != get_parameters().end();
         ++i)
      if (type_base_sptr parm_type = (*i)->get_type())
        if (!parm_type->traverse(v))
          break;

      visiting(false);
    }
  return v.visit_end(this);
}

function_type::~function_type()
{}
// </function_type>

// <method_type>

struct method_type::priv
{
  class_or_union_wptr class_type_;
  bool is_const;

  priv()
    : is_const()
  {}
}; // end struct method_type::priv

/// Constructor for instances of method_type.
///
/// Instances of method_decl must be of type method_type.
///
/// @param return_type the type of the return value of the method.
///
/// @param class_type the base type of the method type.  That is, the
/// type of the class the method belongs to.
///
/// @param p the vector of the parameters of the method.
///
/// @param is_const whether this method type is for a const method.
/// Note that const-ness is a property of the method *type* and of the
/// relationship between a method *declaration* and its scope.
///
/// @param size_in_bits the size of an instance of method_type,
/// expressed in bits.
///
/// @param alignment_in_bits the alignment of an instance of
/// method_type, expressed in bits.
method_type::method_type (type_base_sptr return_type,
              class_or_union_sptr class_type,
              const std::vector<function_decl::parameter_sptr>& p,
              bool is_const,
              size_t size_in_bits,
              size_t alignment_in_bits)
  : type_or_decl_base(class_type->get_environment(),
              METHOD_TYPE | ABSTRACT_TYPE_BASE | FUNCTION_TYPE),
    type_base(class_type->get_environment(), size_in_bits, alignment_in_bits),
    function_type(return_type, p, size_in_bits, alignment_in_bits),
    priv_(new priv)
{
  runtime_type_instance(this);
  set_class_type(class_type);
  set_is_const(is_const);
}

/// Constructor of instances of method_type.
///
///Instances of method_decl must be of type method_type.
///
/// @param return_type the type of the return value of the method.
///
/// @param class_type the type of the class the method belongs to.
/// The actual (dynamic) type of class_type must be a pointer
/// class_type.  We are setting it to pointer to type_base here to
/// help client code that is compiled without rtti and thus cannot
/// perform dynamic casts.
///
/// @param p the vector of the parameters of the method type.
///
/// @param is_const whether this method type is for a const method.
/// Note that const-ness is a property of the method *type* and of the
/// relationship between a method *declaration* and its scope.
///
/// @param size_in_bits the size of an instance of method_type,
/// expressed in bits.
///
/// @param alignment_in_bits the alignment of an instance of
/// method_type, expressed in bits.
method_type::method_type(type_base_sptr return_type,
             type_base_sptr class_type,
             const std::vector<function_decl::parameter_sptr>& p,
             bool is_const,
             size_t size_in_bits,
             size_t alignment_in_bits)
  : type_or_decl_base(class_type->get_environment(),
              METHOD_TYPE | ABSTRACT_TYPE_BASE | FUNCTION_TYPE),
    type_base(class_type->get_environment(), size_in_bits, alignment_in_bits),
    function_type(return_type, p, size_in_bits, alignment_in_bits),
    priv_(new priv)
{
  runtime_type_instance(this);
  set_class_type(is_class_type(class_type));
  set_is_const(is_const);
}

/// Constructor of the qualified_type_def
///
/// @param env the environment we are operating from.
///
/// @param size_in_bits the size of the type, expressed in bits.
///
/// @param alignment_in_bits the alignment of the type, expressed in bits
method_type::method_type(const environment& env,
             size_t     size_in_bits,
             size_t     alignment_in_bits)
  : type_or_decl_base(env, METHOD_TYPE | ABSTRACT_TYPE_BASE | FUNCTION_TYPE),
    type_base(env, size_in_bits, alignment_in_bits),
    function_type(env, size_in_bits, alignment_in_bits),
    priv_(new priv)
{
  runtime_type_instance(this);
}

/// Constructor of instances of method_type.
///
/// When constructed with this constructor, and instane of method_type
/// must set a return type using method_type::set_return_type
///
/// @param class_typ the base type of the method type.  That is, the
/// type of the class (or union) the method belongs to.
///
/// @param size_in_bits the size of an instance of method_type,
/// expressed in bits.
///
/// @param alignment_in_bits the alignment of an instance of
/// method_type, expressed in bits.
method_type::method_type(class_or_union_sptr class_type,
             bool is_const,
             size_t size_in_bits,
             size_t alignment_in_bits)
  : type_or_decl_base(class_type->get_environment(),
              METHOD_TYPE | ABSTRACT_TYPE_BASE | FUNCTION_TYPE),
    type_base(class_type->get_environment(), size_in_bits, alignment_in_bits),
    function_type(class_type->get_environment(),
          size_in_bits,
          alignment_in_bits),
    priv_(new priv)
{
  runtime_type_instance(this);
  set_class_type(class_type);
  set_is_const(is_const);
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
method_type::hash_value() const
{
  hash_t h = set_or_get_cached_hash_value(this);
  return h;
}

/// Get the class type this method belongs to.
///
/// @return the class type.
class_or_union_sptr
method_type::get_class_type() const
{return class_or_union_sptr(priv_->class_type_);}

/// Sets the class type of the current instance of method_type.
///
/// The class type is the type of the class the method belongs to.
///
/// @param t the new class type to set.
void
method_type::set_class_type(const class_or_union_sptr& t)
{
  if (!t)
    return;

  priv_->class_type_ = t;
}

/// Return a copy of the pretty representation of the current @ref
/// method_type.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
///
/// @return a copy of the pretty representation of the current @ref
/// method_type.
string
method_type::get_pretty_representation(bool internal,
                       bool /*qualified_name*/) const
{return ir::get_pretty_representation(*this, internal);}

/// Setter of the "is-const" property of @ref method_type.
///
/// @param the new value of the "is-const" property.
void
method_type::set_is_const(bool f)
{priv_->is_const = f;}

/// Getter of the "is-const" property of @ref method_type.
///
/// @return true iff the "is-const" property was set.
bool
method_type::get_is_const() const
{return priv_->is_const;}

/// Test if the current method type is for a static method or not.
///
/// @return true iff the current method_type denotes a the type of a
/// static method.
bool
method_type::get_is_for_static_method() const
{
  // Let's see if the first parameter is artificial and is a pointer
  // to an instance of the same class type as the current class.
  function_decl::parameter_sptr first_parm;
  if (!get_parameters().empty())
    first_parm = get_parameters()[0];
  if (!first_parm)
    return true;
  if (!first_parm->get_is_artificial())
    return true;

  type_base_sptr this_ptr_type = first_parm->get_type();
  // Sometimes, the type of the "this" pointer is "const class_type*
  // const".  Meaning that the "this pointer" itself is const
  // qualified.  So let's get the underlying non-qualified pointer.
  this_ptr_type = peel_qualified_type(this_ptr_type);
  if (!is_pointer_type(this_ptr_type))
    return true;

  type_base_sptr candidate_class_type =
    is_pointer_type(this_ptr_type)->get_pointed_to_type();
  candidate_class_type = peel_qualified_type(candidate_class_type);
  if (is_class_type(candidate_class_type)
      && get_type_name(candidate_class_type) == get_type_name(get_class_type()))
    // At this point, we are sure we are looking at a *non-static*
    // method.
    return false;

  return true;
}

/// The destructor of method_type
method_type::~method_type()
{}

// </method_type>

// <function_decl definitions>

struct function_decl::priv
{
  bool          declared_inline_;
  decl_base::binding    binding_;
  function_type_wptr    type_;
  function_type*    naked_type_;
  elf_symbol_sptr   symbol_;
  interned_string id_;

  priv()
    : declared_inline_(false),
      binding_(decl_base::BINDING_GLOBAL),
      naked_type_()
  {}

  priv(function_type_sptr t,
       bool declared_inline,
       decl_base::binding binding)
    : declared_inline_(declared_inline),
      binding_(binding),
      type_(t),
      naked_type_(t.get())
  {}

  priv(function_type_sptr t,
       bool declared_inline,
       decl_base::binding binding,
       elf_symbol_sptr s)
    : declared_inline_(declared_inline),
      binding_(binding),
      type_(t),
      naked_type_(t.get()),
      symbol_(s)
  {}
}; // end sruct function_decl::priv

/// Constructor of the @ref function_decl.
///
/// @param name the name of the function.
///
/// @param function_type the type of the function.
///
/// @param declared_inline wether the function is declared inline.
///
/// @param locus the source location of the function.
///
/// @param mangled_name the linkage name of the function.
///
/// @param vis the visibility of the function.
///
/// @param bind the binding of the function.
function_decl::function_decl(const string& name,
                 function_type_sptr function_type,
                 bool declared_inline,
                 const location& locus,
                 const string& mangled_name,
                 visibility vis,
                 binding bind)
  : type_or_decl_base(function_type->get_environment(),
              FUNCTION_DECL | ABSTRACT_DECL_BASE),
    decl_base(function_type->get_environment(), name, locus, mangled_name, vis),
    priv_(new priv(function_type, declared_inline, bind))
{
  runtime_type_instance(this);
}

/// Constructor of the function_decl type.
///
/// This flavour of constructor is for when the pointer to the
/// instance of function_type that the client code has is presented as
/// a pointer to type_base.  In that case, this constructor saves the
/// client code from doing a dynamic_cast to get the function_type
/// pointer.
///
/// @param name the name of the function declaration.
///
/// @param fn_type the type of the function declaration.  The dynamic
/// type of this parameter should be 'pointer to function_type'
///
/// @param declared_inline whether this function was declared inline
///
/// @param locus the source location of the function declaration.
///
/// @param linkage_name the mangled name of the function declaration.
///
/// @param vis the visibility of the function declaration.
///
/// @param bind  the kind of the binding of the function
/// declaration.
function_decl::function_decl(const string&  name,
                 type_base_sptr fn_type,
                 bool       declared_inline,
                 const location&    locus,
                 const string&  linkage_name,
                 visibility vis,
                 binding        bind)
  : type_or_decl_base(fn_type->get_environment(),
              FUNCTION_DECL | ABSTRACT_DECL_BASE),
    decl_base(fn_type->get_environment(), name, locus, linkage_name, vis),
    priv_(new priv(dynamic_pointer_cast<function_type>(fn_type),
           declared_inline,
           bind))
{
  runtime_type_instance(this);
}

/// Get the pretty representation of the current instance of @ref function_decl.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
///
/// @return the pretty representation for a function.
string
function_decl::get_pretty_representation(bool internal,
                     bool qualified_name) const
{
  const method_decl* mem_fn =
    dynamic_cast<const method_decl*>(this);

  string fn_prefix = mem_fn ? "method ": "function ";
  string result;

  if (mem_fn
      && is_member_function(mem_fn)
      && get_member_function_is_virtual(mem_fn))
    fn_prefix += "virtual ";

  decl_base_sptr return_type;
  if ((mem_fn
       && is_member_function(mem_fn)
       && (get_member_function_is_dtor(*mem_fn)
       || get_member_function_is_ctor(*mem_fn))))
    /*cdtors do not have return types.  */;
  else
    return_type = mem_fn
      ? get_type_declaration(mem_fn->get_type()->get_return_type())
      : get_type_declaration(get_type()->get_return_type());

  result = get_pretty_representation_of_declarator(internal);
  if (return_type)
    {
      if (is_npaf_type(is_type(return_type))
      || !(is_pointer_to_function_type(is_type(return_type))
           || is_pointer_to_array_type(is_type(return_type))))
    result = get_type_name(is_type(return_type).get(), qualified_name,
                   internal) + " " + result;
      else if (pointer_type_def_sptr p =
           is_pointer_to_function_type(is_type(return_type)))
    result = add_outer_pointer_to_fn_type_expr(p, result,
                           /*qualified=*/true,
                           internal);
      else if(pointer_type_def_sptr p =
          is_pointer_to_array_type(is_type(return_type)))
    result = add_outer_pointer_to_array_type_expr(p, result,
                              qualified_name,
                              internal);
      else
    ABG_ASSERT_NOT_REACHED;
    }

  return fn_prefix + result;
}

/// Compute and return the pretty representation for the part of the
/// function declaration that starts at the declarator.  That is, the
/// return type and the other specifiers of the beginning of the
/// function's declaration ar omitted.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
///
/// @return the pretty representation for the part of the function
/// declaration that starts at the declarator.
string
function_decl::get_pretty_representation_of_declarator (bool internal) const
{
  const method_decl* mem_fn =
    dynamic_cast<const method_decl*>(this);

  string result;

  if (mem_fn)
    {
      result += mem_fn->get_type()->get_class_type()->get_qualified_name()
    + "::" + mem_fn->get_name();
    }
  else
    result += get_qualified_name();

  std::ostringstream fn_parms;
  stream_pretty_representation_of_fn_parms(*get_type(),
                       fn_parms,
                       /*qualified=*/true,
                       internal);
  result += fn_parms.str();

  if (mem_fn
      &&((is_member_function(mem_fn) && get_member_function_is_const(*mem_fn))
     || is_method_type(mem_fn->get_type())->get_is_const()))
    result += " const";

  return result;
}

/// Getter for the first non-implicit parameter of a function decl.
///
/// If the function is a non-static member function, the parameter
/// returned is the first one following the implicit 'this' parameter.
///
/// @return the first non implicit parm.
function_decl::parameters::const_iterator
function_decl::get_first_non_implicit_parm() const
{
  if (get_parameters().empty())
    return get_parameters().end();

  bool is_method = dynamic_cast<const method_decl*>(this);

  parameters::const_iterator i = get_parameters().begin();
  if (is_method)
    ++i;

  return i;
}

/// Return the type of the current instance of @ref function_decl.
///
/// It's either a function_type or method_type.
/// @return the type of the current instance of @ref function_decl.
const shared_ptr<function_type>
function_decl::get_type() const
{return priv_->type_.lock();}

/// Fast getter of the type of the current instance of @ref function_decl.
///
/// Note that this function returns the underlying pointer managed by
/// the smart pointer returned by function_decl::get_type().  It's
/// faster than function_decl::get_type().  This getter is to be used
/// in code paths that are proven to be performance hot spots;
/// especially (for instance) when comparing function types.  Those
/// are compared extremely frequently when libabigail is used to
/// handle huge binaries with a lot of functions.
///
/// @return the type of the current instance of @ref function_decl.
const function_type*
function_decl::get_naked_type() const
{return priv_->naked_type_;}

void
function_decl::set_type(const function_type_sptr& fn_type)
{
  priv_->type_ = fn_type;
  priv_->naked_type_ = fn_type.get();
}

/// This sets the underlying ELF symbol for the current function decl.
///
/// And underlyin$g ELF symbol for the current function decl might
/// exist only if the corpus that this function decl originates from
/// was constructed from an ELF binary file.
///
/// Note that comparing two function decls that have underlying ELF
/// symbols involves comparing their underlying elf symbols.  The decl
/// name for the function thus becomes irrelevant in the comparison.
///
/// @param sym the new ELF symbol for this function decl.
void
function_decl::set_symbol(const elf_symbol_sptr& sym)
{
  priv_->symbol_ = sym;
  // The function id cache that depends on the symbol must be
  // invalidated because the symbol changed.
  priv_->id_ = get_environment().intern("");
}

/// Gets the the underlying ELF symbol for the current variable,
/// that was set using function_decl::set_symbol().  Please read the
/// documentation for that member function for more information about
/// "underlying ELF symbols".
///
/// @return sym the underlying ELF symbol for this function decl, if
/// one exists.
const elf_symbol_sptr&
function_decl::get_symbol() const
{return priv_->symbol_;}

/// Test if the function was declared inline.
///
/// @return true iff the function was declared inline.
bool
function_decl::is_declared_inline() const
{return priv_->declared_inline_;}

/// Set the property of the function being declared inline.
///
/// @param value true iff the function was declared inline.
void
function_decl::is_declared_inline(bool value)
{priv_->declared_inline_ = value;}

decl_base::binding
function_decl::get_binding() const
{return priv_->binding_;}

/// @return the return type of the current instance of function_decl.
const shared_ptr<type_base>
function_decl::get_return_type() const
{return get_type()->get_return_type();}

/// @return the parameters of the function.
const std::vector<shared_ptr<function_decl::parameter> >&
function_decl::get_parameters() const
{return get_type()->get_parameters();}

/// Append a parameter to the type of this function.
///
/// @param parm the parameter to append.
void
function_decl::append_parameter(shared_ptr<parameter> parm)
{get_type()->append_parameter(parm);}

/// Append a vector of parameters to the type of this function.
///
/// @param parms the vector of parameters to append.
void
function_decl::append_parameters(std::vector<shared_ptr<parameter> >& parms)
{
  for (std::vector<shared_ptr<parameter> >::const_iterator i = parms.begin();
       i != parms.end();
       ++i)
    get_type()->append_parameter(*i);
}

/// Create a new instance of function_decl that is a clone of the
/// current one.
///
/// @return the new clone.
function_decl_sptr
function_decl::clone() const
{
  function_decl_sptr f;
  if (is_member_function(*this))
    {
      method_decl_sptr
    m(new method_decl(get_name(),
              get_type(),
              is_declared_inline(),
              get_location(),
              get_linkage_name(),
              get_visibility(),
              get_binding()));
      class_or_union* scope = is_class_or_union_type(get_scope());
      ABG_ASSERT(scope);
      scope->add_member_function(m, get_member_access_specifier(*this),
                 get_member_function_is_virtual(*this),
                 get_member_function_vtable_offset(*this),
                 get_member_is_static(*this),
                 get_member_function_is_ctor(*this),
                 get_member_function_is_dtor(*this),
                 get_member_function_is_const(*this));
      f = m;
    }
  else
    {
      f.reset(new function_decl(get_name(),
                get_type(),
                is_declared_inline(),
                get_location(),
                get_linkage_name(),
                get_visibility(),
                get_binding()));
      add_decl_to_scope(f, get_scope());
    }
  f->set_symbol(get_symbol());

  return f;
}

/// Compares two instances of @ref function_decl.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const function_decl& l, const function_decl& r, change_kind* k)
{
  bool result = true;

  // Compare function types
  const type_base* t0 = l.get_naked_type(), *t1 = r.get_naked_type();
  if (t0 == t1 || *t0 == *t1)
    ; // the types are equal, let's move on to compare the other
      // properties of the functions.
  else
    {
      result = false;
      if (k)
    {
      if (!types_have_similar_structure(t0, t1))
        *k |= LOCAL_TYPE_CHANGE_KIND;
      else
        *k |= SUBTYPE_CHANGE_KIND;
    }
      else
    ABG_RETURN_FALSE;
    }

  const elf_symbol_sptr &s0 = l.get_symbol(), &s1 = r.get_symbol();
  if (!!s0 != !!s1)
    {
      result = false;
      if (k)
    *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }
  else if (s0 && s0 != s1)
    {
      if (!elf_symbols_alias(s0, s1))
    {
      result = false;
      if (k)
        *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
        ABG_RETURN_FALSE;
    }
    }
  bool symbols_are_equal = (s0 && s1 && result);

  if (symbols_are_equal)
    {
      // The functions have underlying elf symbols that are equal,
      // so now, let's compare the decl_base part of the functions
      // w/o considering their decl names.
      interned_string n1 = l.get_name(), n2 = r.get_name();
      interned_string ln1 = l.get_linkage_name(), ln2 = r.get_linkage_name();
      const_cast<function_decl&>(l).set_name("");
      const_cast<function_decl&>(l).set_linkage_name("");
      const_cast<function_decl&>(r).set_name("");
      const_cast<function_decl&>(r).set_linkage_name("");

      bool decl_bases_different = !l.decl_base::operator==(r);

      const_cast<function_decl&>(l).set_name(n1);
      const_cast<function_decl&>(l).set_linkage_name(ln1);
      const_cast<function_decl&>(r).set_name(n2);
      const_cast<function_decl&>(r).set_linkage_name(ln2);

      if (decl_bases_different)
    {
      result = false;
      if (k)
        *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
        ABG_RETURN_FALSE;
    }
    }
  else
    if (!l.decl_base::operator==(r))
      {
    result = false;
    if (k)
      *k |= LOCAL_NON_TYPE_CHANGE_KIND;
    else
      ABG_RETURN_FALSE;
      }

  // Compare the remaining properties.  Note that we don't take into
  // account the fact that the function was declared inline or not as
  // that doesn't have any impact on the final ABI.
  if (l.get_binding() != r.get_binding())
    {
      result = false;
      if (k)
    *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }

  if (is_member_function(l) != is_member_function(r))
    {
      result = false;
      if (k)
      *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
    ABG_RETURN_FALSE;
    }

  if (is_member_function(l) && is_member_function(r))
    {
      if (!((get_member_function_is_ctor(l)
         == get_member_function_is_ctor(r))
        && (get_member_function_is_dtor(l)
        == get_member_function_is_dtor(r))
        && (get_member_is_static(l)
        == get_member_is_static(r))
        && (get_member_function_is_const(l)
        == get_member_function_is_const(r))
        && (get_member_function_is_virtual(l)
        == get_member_function_is_virtual(r))
        && (get_member_function_vtable_offset(l)
        == get_member_function_vtable_offset(r))))
    {
      result = false;
      if (k)
        *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
        ABG_RETURN_FALSE;
    }
    }

  ABG_RETURN(result);
}

/// Comparison operator for @ref function_decl.
///
/// @param other the other instance of @ref function_decl to compare
/// against.
///
/// @return true iff the current instance of @ref function_decl equals
/// @p other.
bool
function_decl::operator==(const decl_base& other) const
{
  const function_decl* o = dynamic_cast<const function_decl*>(&other);
  if (!o)
    return false;
  return equals(*this, *o, 0);
}

/// Return true iff the function takes a variable number of
/// parameters.
///
/// @return true if the function taks a variable number
/// of parameters.
bool
function_decl::is_variadic() const
{
  return (!get_parameters().empty()
      && get_parameters().back()->get_variadic_marker());
}

/// Return an ID that tries to uniquely identify the function inside a
/// program or a library.
///
/// So if the function has an underlying elf symbol, the ID is the
/// concatenation of the symbol name and its version.  Otherwise, the
/// ID is the linkage name if its non-null.  Otherwise, it's the
/// pretty representation of the function.
///
/// @return the ID.
interned_string
function_decl::get_id() const
{
  if (priv_->id_.empty())
    {
      const environment& env = get_type()->get_environment();
      if (elf_symbol_sptr s = get_symbol())
    {
      string virtual_member_suffix;
      if (is_member_function(this))
          {
        method_decl* m = is_method_decl(this);
        ABG_ASSERT(m);
        if (get_member_function_is_virtual(m))
          {
            if (is_declaration_only_class_or_union_type
            (m->get_type()->get_class_type(),
             /*look_through_decl_only=*/true))
              virtual_member_suffix += "/o";
          }
          }
      if (s->has_aliases())
        // The symbol has several aliases, so let's use a scheme
        // that allows all aliased functions to have different
        // IDs.
        priv_->id_ = env.intern(get_name() + "/" + s->get_id_string());
      else
        // Let's use the full symbol name with its version as ID.
        priv_->id_ = env.intern(s->get_id_string());

      if (!virtual_member_suffix.empty())
        priv_->id_ = env.intern(priv_->id_ + virtual_member_suffix);
    }
      else if (!get_linkage_name().empty())
    priv_->id_= env.intern(get_linkage_name());
      else
    priv_->id_ = env.intern(get_pretty_representation());
    }
  return priv_->id_;
}

/// Test if two function declarations are aliases.
///
/// Two functions declarations are aliases if their symbols are
/// aliases, in the ELF sense.
///
/// @param f1 the first function to consider.
///
/// @param f2 the second function to consider.
///
/// @return true iff @p f1 is an alias of @p f2
bool
function_decls_alias(const function_decl& f1, const function_decl& f2)
{
  elf_symbol_sptr s1 = f1.get_symbol(), s2 = f2.get_symbol();

  if (!s1 || !s2)
    return false;

  return elf_symbols_alias(s1, s2);
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
function_decl::traverse(ir_node_visitor& v)
{
  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      if (type_base_sptr t = get_type())
    t->traverse(v);
      visiting(false);
    }
  return v.visit_end(this);
}

/// Destructor of the @ref function_decl type.
function_decl::~function_decl()
{delete priv_;}

/// A deep comparison operator for a shared pointer to @ref function_decl
///
/// This function compares to shared pointers to @ref function_decl by
/// looking at the pointed-to instances of @ref function_dec
/// comparing them too.  If the two pointed-to objects are equal then
/// this function returns true.
///
/// @param l the left-hand side argument of the equality operator.
///
/// @param r the right-hand side argument of the equality operator.
///
/// @return true iff @p l equals @p r.
bool
operator==(const function_decl_sptr& l, const function_decl_sptr& r)
{
  if (l.get() == r.get())
    return true;
  if (!!l != !!r)
    return false;

  return *l == *r;
}

/// A deep inequality operator for smart pointers to functions.
///
/// @param l the left-hand side argument of the inequality operator.
///
/// @pram r the right-hand side argument of the inequality operator.
///
/// @return true iff @p is not equal to @p r.
bool
operator!=(const function_decl_sptr& l, const function_decl_sptr& r)
{return !operator==(l, r);}

// <function_decl definitions>

// <function_decl::parameter definitions>

struct function_decl::parameter::priv
{
  type_base_wptr    type_;
  unsigned      index_;
  bool          variadic_marker_;

  priv()
    : index_(),
      variadic_marker_()
  {}

  priv(type_base_sptr type,
       unsigned index,
       bool variadic_marker)
    : type_(type),
      index_(index),
      variadic_marker_(variadic_marker)
  {}
};// end struct function_decl::parameter::priv

function_decl::parameter::parameter(const type_base_sptr    type,
                    unsigned            index,
                    const string&       name,
                    const location&     loc,
                    bool            is_variadic)
  : type_or_decl_base(type->get_environment(),
              FUNCTION_PARAMETER_DECL | ABSTRACT_DECL_BASE),
    decl_base(type->get_environment(), name, loc),
    priv_(new priv(type, index, is_variadic))
{
  runtime_type_instance(this);
}

function_decl::parameter::parameter(const type_base_sptr    type,
                    unsigned            index,
                    const string&       name,
                    const location&     loc,
                    bool            is_variadic,
                    bool            is_artificial)
  : type_or_decl_base(type->get_environment(),
              FUNCTION_PARAMETER_DECL | ABSTRACT_DECL_BASE),
    decl_base(type->get_environment(), name, loc),
    priv_(new priv(type, index, is_variadic))
{
  runtime_type_instance(this);
  set_is_artificial(is_artificial);
}

function_decl::parameter::parameter(const type_base_sptr    type,
                    const string&       name,
                    const location&     loc,
                    bool            is_variadic,
                    bool            is_artificial)
  : type_or_decl_base(type->get_environment(),
              FUNCTION_PARAMETER_DECL | ABSTRACT_DECL_BASE),
    decl_base(type->get_environment(), name, loc),
    priv_(new priv(type, 0, is_variadic))
{
  runtime_type_instance(this);
  set_is_artificial(is_artificial);
}

function_decl::parameter::parameter(const type_base_sptr    type,
                    unsigned            index,
                    bool            variad)
  : type_or_decl_base(type->get_environment(),
              FUNCTION_PARAMETER_DECL | ABSTRACT_DECL_BASE),
    decl_base(type->get_environment(), "", location()),
    priv_(new priv(type, index, variad))
{
  runtime_type_instance(this);
}

function_decl::parameter::~parameter() = default;

const type_base_sptr
function_decl::parameter::get_type()const
{return priv_->type_.lock();}

/// @return a copy of the type name of the parameter.
interned_string
function_decl::parameter::get_type_name() const
{
  const environment& env = get_environment();

  type_base_sptr t = get_type();
  string str;
  if (get_variadic_marker() || env.is_variadic_parameter_type(t))
    str = "...";
  else
    {
    ABG_ASSERT(t);
    str = abigail::ir::get_type_name(t);
    }
  return env.intern(str);
}

/// @return a copy of the pretty representation of the type of the
/// parameter.
const string
function_decl::parameter::get_type_pretty_representation() const
{
  type_base_sptr t = get_type();
  string str;
  if (get_variadic_marker()
      || get_environment().is_variadic_parameter_type(t))
    str = "...";
  else
    {
    ABG_ASSERT(t);
    str += get_type_declaration(t)->get_pretty_representation();
    }
  return str;
}

/// Get a name uniquely identifying the parameter in the function.
///
///@return the unique parm name id.
interned_string
function_decl::parameter::get_name_id() const
{
  const environment& env = get_environment();


  std::ostringstream o;
  o << "parameter-" << get_index();

  return env.intern(o.str());
}

unsigned
function_decl::parameter::get_index() const
{return priv_->index_;}

void
function_decl::parameter::set_index(unsigned i)
{priv_->index_ = i;}


bool
function_decl::parameter::get_variadic_marker() const
{return priv_->variadic_marker_;}

/// Compares two instances of @ref function_decl::parameter.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const function_decl::parameter& l,
       const function_decl::parameter& r,
       change_kind* k)
{
  bool result = true;

  if ((l.get_variadic_marker() != r.get_variadic_marker())
      || (l.get_index() != r.get_index())
      || (!!l.get_type() != !!r.get_type()))
    {
      result = false;
      if (k)
    {
      if (l.get_index() != r.get_index())
        *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      if (l.get_variadic_marker() != r.get_variadic_marker()
          || !!l.get_type() != !!r.get_type())
        *k |= LOCAL_TYPE_CHANGE_KIND;
    }
      else
    ABG_RETURN_FALSE;
    }

  type_base_sptr l_type = l.get_type();
  type_base_sptr r_type = r.get_type();

  if (l_type != r_type)
    {
      result = false;
      if (k)
    {
      if (!types_have_similar_structure(l_type, r_type))
        *k |= LOCAL_TYPE_CHANGE_KIND;
      else
        *k |= SUBTYPE_CHANGE_KIND;
    }
      else
    ABG_RETURN_FALSE;
    }

  ABG_RETURN(result);
}

bool
function_decl::parameter::operator==(const parameter& o) const
{return equals(*this, o, 0);}

bool
function_decl::parameter::operator==(const decl_base& o) const
{
  const function_decl::parameter* p =
    dynamic_cast<const function_decl::parameter*>(&o);
  if (!p)
    return false;
  return function_decl::parameter::operator==(*p);
}

/// Non-member equality operator for @ref function_decl::parameter.
///
/// @param l the left-hand side of the equality operator
///
/// @param r the right-hand side of the equality operator
///
/// @return true iff @p l and @p r equals.
bool
operator==(const function_decl::parameter_sptr& l,
       const function_decl::parameter_sptr& r)
{
  if (!!l != !!r)
    return false;
  if (!l)
    return true;
  return *l == *r;
}

/// Non-member inequality operator for @ref function_decl::parameter.
///
/// @param l the left-hand side of the equality operator
///
/// @param r the right-hand side of the equality operator
///
/// @return true iff @p l and @p r different.
bool
operator!=(const function_decl::parameter_sptr& l,
       const function_decl::parameter_sptr& r)
{return !operator==(l, r);}

/// Traverse the diff sub-tree under the current instance
/// function_decl.
///
/// @param v the visitor to invoke on each diff node of the sub-tree.
///
/// @return true if the traversing has to keep going on, false
/// otherwise.
bool
function_decl::parameter::traverse(ir_node_visitor& v)
{
  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      if (type_base_sptr t = get_type())
    t->traverse(v);
      visiting(false);
    }
  return v.visit_end(this);
}

/// Compute the qualified name of the parameter.
///
/// @param internal set to true if the call is intended for an
/// internal use (for technical use inside the library itself), false
/// otherwise.  If you don't know what this is for, then set it to
/// false.
///
/// @param qn the resulting qualified name.
void
function_decl::parameter::get_qualified_name(interned_string& qualified_name,
                         bool /*internal*/) const
{qualified_name = get_name();}

/// Compute and return a copy of the pretty representation of the
/// current function parameter.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
///
/// @return a copy of the textual representation of the current
/// function parameter.
string
function_decl::parameter::get_pretty_representation(bool internal,
                            bool qualified_name) const
{
  const environment& env = get_environment();

  string type_repr;
  type_base_sptr t = get_type();
  if (!t)
    type_repr = "void";
  else if (env.is_variadic_parameter_type(t))
    type_repr = "...";
  else
    type_repr = ir::get_type_name(t, qualified_name, internal);

  string result = type_repr;
  string parm_name = get_name_id();

  if (!parm_name.empty())
    result += " " + parm_name;

  return result;
}

// </function_decl::parameter definitions>

// <class_or_union definitions>

/// A Constructor for instances of @ref class_or_union
///
/// @param env the environment we are operating from.
///
/// @param name the identifier of the class.
///
/// @param size_in_bits the size of an instance of @ref
/// class_or_union, expressed in bits
///
/// @param align_in_bits the alignment of an instance of @ref class_or_union,
/// expressed in bits.
///
/// @param locus the source location of declaration point this class.
///
/// @param vis the visibility of instances of @ref class_or_union.
///
/// @param mem_types the vector of member types of this instance of
/// @ref class_or_union.
///
/// @param data_members the vector of data members of this instance of
/// @ref class_or_union.
///
/// @param member_fns the vector of member functions of this instance
/// of @ref class_or_union.
class_or_union::class_or_union(const environment& env, const string& name,
                   size_t size_in_bits, size_t align_in_bits,
                   const location& locus, visibility vis,
                   member_types& mem_types,
                   data_members& data_members,
                   member_functions& member_fns)
  : type_or_decl_base(env,
              ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE
              | ABSTRACT_SCOPE_TYPE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(env, name, locus, name, vis),
    type_base(env, size_in_bits, align_in_bits),
    scope_type_decl(env, name, size_in_bits, align_in_bits, locus, vis),
    priv_(new priv(data_members, member_fns))
{
  for (member_types::iterator i = mem_types.begin();
       i != mem_types.end();
       ++i)
    if (!has_scope(get_type_declaration(*i)))
      add_decl_to_scope(get_type_declaration(*i), this);

  for (data_members::iterator i = data_members.begin();
       i != data_members.end();
       ++i)
    if (!has_scope(*i))
      add_decl_to_scope(*i, this);

  for (member_functions::iterator i = member_fns.begin();
       i != member_fns.end();
       ++i)
    if (!has_scope(static_pointer_cast<decl_base>(*i)))
      add_decl_to_scope(*i, this);
}

/// A constructor for instances of @ref class_or_union.
///
/// @param env the environment we are operating from.
///
/// @param name the name of the class.
///
/// @param size_in_bits the size of an instance of @ref
/// class_or_union, expressed in bits
///
/// @param align_in_bits the alignment of an instance of @ref class_or_union,
/// expressed in bits.
///
/// @param locus the source location of declaration point this class.
///
/// @param vis the visibility of instances of @ref class_or_union.
class_or_union::class_or_union(const environment& env, const string& name,
                   size_t size_in_bits, size_t align_in_bits,
                   const location& locus, visibility vis)
  : type_or_decl_base(env,
              ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE
              | ABSTRACT_SCOPE_TYPE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(env, name, locus, name, vis),
    type_base(env, size_in_bits, align_in_bits),
    scope_type_decl(env, name, size_in_bits, align_in_bits, locus, vis),
    priv_(new priv)
{}

/// Constructor of the @ref class_or_union type.
///
/// @param env the @ref environment we are operating from.
///
/// @param name the name of the @ref class_or_union.
///
/// @param is_declaration_only a boolean saying whether the instance
/// represents a declaration only, or not.
class_or_union::class_or_union(const environment& env, const string& name,
                   bool is_declaration_only)
  : type_or_decl_base(env,
              ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE
              | ABSTRACT_SCOPE_TYPE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(env, name, location(), name),
    type_base(env, 0, 0),
    scope_type_decl(env, name, 0, 0, location()),
    priv_(new priv)
{
  set_is_declaration_only(is_declaration_only);
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
class_or_union::hash_value() const
{
  class_or_union::hash do_hash;
  hash_t h = do_hash(this);
  return h;
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the member nodes of the translation
/// unit during the traversal.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
class_or_union::traverse(ir_node_visitor& v)
{
  if (v.type_node_has_been_visited(this))
    return true;

  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      bool stop = false;

      if (!stop)
    for (data_members::const_iterator i = get_data_members().begin();
         i != get_data_members().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }

      if (!stop)
    for (member_functions::const_iterator i= get_member_functions().begin();
         i != get_member_functions().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }

      if (!stop)
    for (member_types::const_iterator i = get_member_types().begin();
         i != get_member_types().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }

      if (!stop)
    for (member_function_templates::const_iterator i =
           get_member_function_templates().begin();
         i != get_member_function_templates().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }

      if (!stop)
    for (member_class_templates::const_iterator i =
           get_member_class_templates().begin();
         i != get_member_class_templates().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }
      visiting(false);
    }

  bool result = v.visit_end(this);
  v.mark_type_node_as_visited(this);
  return result;
}

/// Destrcutor of the @ref class_or_union type.
class_or_union::~class_or_union()
{delete priv_;}

/// Add a member declaration to the current instance of class_or_union.
/// The member declaration can be either a member type, data member,
/// member function, or member template.
///
/// @param d the member declaration to add.
decl_base_sptr
class_or_union::add_member_decl(const decl_base_sptr& d)
{return insert_member_decl(d);}

/// Remove a given decl from the current @ref class_or_union scope.
///
/// Note that only type declarations are supported by this method for
/// now.  Support for the other kinds of declaration is left as an
/// exercise for the interested reader of the code.
///
/// @param decl the declaration to remove from this @ref
/// class_or_union scope.
void
class_or_union::remove_member_decl(decl_base_sptr decl)
{
  type_base_sptr t = is_type(decl);

  // For now we want to support just removing types from classes.  For
  // other kinds of IR node, we need more work.
  ABG_ASSERT(t);

  remove_member_type(t);
}

/// Fixup the members of the type of an anonymous data member.
///
/// Walk all data members of (the type of) a given anonymous data
/// member and set a particular property of the relationship between
/// each data member and its containing type.
///
/// That property records the fact that the data member belongs to the
/// anonymous data member we consider.
///
/// In the future, if there are other properties of this relationship
/// to set in this manner, they ought to be added here.
///
/// @param anon_dm the anonymous data member to consider.
void
class_or_union::maybe_fixup_members_of_anon_data_member(var_decl_sptr& anon_dm)
{
  class_or_union * anon_dm_type =
    anonymous_data_member_to_class_or_union(anon_dm.get());
  if (!anon_dm_type)
    return;

  for (class_or_union::data_members::const_iterator it =
     anon_dm_type->get_non_static_data_members().begin();
       it != anon_dm_type->get_non_static_data_members().end();
       ++it)
    {
      dm_context_rel *rel =
    dynamic_cast<dm_context_rel*>((*it)->get_context_rel());
      ABG_ASSERT(rel);
      rel->set_anonymous_data_member(anon_dm.get());
    }
}

/// Getter of the alignment of the @ref class_or_union type.
///
/// If this @ref class_or_union is a declaration of a definition that
/// is elsewhere, then the size of the definition is returned.
///
/// @return the alignment of the @ref class_or_union type.
size_t
class_or_union::get_alignment_in_bits() const
{
  if (get_is_declaration_only() && get_definition_of_declaration())
    return is_class_or_union_type
      (get_definition_of_declaration())->get_alignment_in_bits();

   return type_base::get_alignment_in_bits();
}

/// Setter of the alignment of the class type.
///
/// If this class is a declaration of a definition that is elsewhere,
/// then the new alignment is set to the definition.
///
/// @param s the new alignment.
void
class_or_union::set_alignment_in_bits(size_t a)
{
  if (get_is_declaration_only() && get_definition_of_declaration())
    is_class_or_union_type
      (get_definition_of_declaration()) ->set_alignment_in_bits(a);
  else
    type_base::set_alignment_in_bits(a);
}

/// Setter of the size of the @ref class_or_union type.
///
/// If this @ref class_or_union is a declaration of a definition that
/// is elsewhere, then the new size is set to the definition.
///
/// @param s the new size.
void
class_or_union::set_size_in_bits(size_t s)
{
  if (get_is_declaration_only() && get_definition_of_declaration())
    is_class_or_union_type
      (get_definition_of_declaration())->set_size_in_bits(s);
  else
    type_base::set_size_in_bits(s);
}

/// Getter of the size of the @ref class_or_union type.
///
/// If this @ref class_or_union is a declaration of a definition that
/// is elsewhere, then the size of the definition is returned.
///
/// @return the size of the @ref class_or_union type.
size_t
class_or_union::get_size_in_bits() const
{
  if (get_is_declaration_only() && get_definition_of_declaration())
    return is_class_or_union_type
      (get_definition_of_declaration())->get_size_in_bits();

  return type_base::get_size_in_bits();
}

/// Get the number of anonymous member classes contained in this
/// class.
///
/// @return the number of anonymous member classes contained in this
/// class.
size_t
class_or_union::get_num_anonymous_member_classes() const
{
  int result = 0;
  for (member_types::const_iterator it = get_member_types().begin();
       it != get_member_types().end();
       ++it)
    if (class_decl_sptr t = is_class_type(*it))
      if (t->get_is_anonymous())
    ++result;

  return result;
}

/// Get the number of anonymous member unions contained in this class.
///
/// @return the number of anonymous member unions contained in this
/// class.
size_t
class_or_union::get_num_anonymous_member_unions() const
{
  int result = 0;
  for (member_types::const_iterator it = get_member_types().begin();
       it != get_member_types().end();
       ++it)
    if (union_decl_sptr t = is_union_type(*it))
      if (t->get_is_anonymous())
    ++result;

  return result;
}

/// Get the number of anonymous member enums contained in this class.
///
/// @return the number of anonymous member enums contained in this
/// class.
size_t
class_or_union::get_num_anonymous_member_enums() const
{
  int result = 0;
  for (member_types::const_iterator it = get_member_types().begin();
       it != get_member_types().end();
       ++it)
    if (enum_type_decl_sptr t = is_enum_type(*it))
      if (t->get_is_anonymous())
    ++result;

  return result;
}

/// Add a data member to the current instance of class_or_union.
///
/// @param v a var_decl to add as a data member.  A proper
/// class_or_union::data_member is created from @p v and added to the
/// class_or_union.  This var_decl should not have been already added
/// to a scope.
///
/// @param access the access specifier for the data member.
///
/// @param is_laid_out whether the data member was laid out.  That is,
/// if its offset has been computed.  In the pattern of a class
/// template for instance, this would be set to false.
///
/// @param is_static whether the data memer is static.
///
/// @param offset_in_bits if @p is_laid_out is true, this is the
/// offset of the data member, expressed (oh, surprise) in bits.
void
class_or_union::add_data_member(var_decl_sptr v, access_specifier access,
                bool is_laid_out, bool is_static,
                size_t offset_in_bits)
{
  ABG_ASSERT(!has_scope(v));

  priv_->data_members_.push_back(v);
  scope_decl::add_member_decl(v);
  set_data_member_is_laid_out(v, is_laid_out);
  set_data_member_offset(v, offset_in_bits);
  set_member_access_specifier(v, access);
  set_member_is_static(v, is_static);

  // Add the variable to the set of static or non-static data members,
  // if it's not already in there.
  bool is_already_in = false;
  if (is_static)
    {
      for (const auto& s_dm: priv_->static_data_members_)
    {
      if (s_dm == v)
        {
          is_already_in = true;
          break;
        }
    }
      if (!is_already_in)
    priv_->static_data_members_.push_back(v);
    }
  else
    {
      // If this is a non-static variable, add it to the set of
      // non-static variables, if it's not already in there.
      for (data_members::const_iterator i =
         priv_->non_static_data_members_.begin();
       i != priv_->non_static_data_members_.end();
       ++i)
    if (*i == v)
      {
        is_already_in = true;
        break;
      }
      if (!is_already_in)
    priv_->non_static_data_members_.push_back(v);
    }

  // If v is an anonymous data member, then fixup its data members.
  // For now, the only thing the fixup does is to make the data
  // members of the anonymous data member be aware of their containing
  // anonymous data member.  That is helpful to compute the absolute
  // bit offset of each of the members of the anonymous data member.
  maybe_fixup_members_of_anon_data_member(v);
}

/// Get the data members of this @ref class_or_union.
///
/// @return a vector of the data members of this @ref class_or_union.
const class_or_union::data_members&
class_or_union::get_data_members() const
{return priv_->data_members_;}

/// Find a data member of a given name in the current @ref class_or_union.
///
/// @param name the name of the data member to find in the current
/// @ref class_or_union.
///
/// @return a pointer to the @ref var_decl that represents the data
/// member to find inside the current @ref class_or_union.
const var_decl_sptr
class_or_union::find_data_member(const string& name) const
{
  for (data_members::const_iterator i = get_data_members().begin();
       i != get_data_members().end();
       ++i)
    if ((*i)->get_name() == name)
      return *i;

  // We haven't found a data member with the name 'name'.  Let's look
  // closer again, this time in our anonymous data members.
  for (data_members::const_iterator i = get_data_members().begin();
       i != get_data_members().end();
       ++i)
    if (is_anonymous_data_member(*i))
      {
    class_or_union_sptr type = is_class_or_union_type((*i)->get_type());
    ABG_ASSERT(type);
    if (var_decl_sptr data_member = type->find_data_member(name))
      return data_member;
      }

  return var_decl_sptr();
}

/// Find an anonymous data member in the class.
///
/// @param v the anonymous data member to find.
///
/// @return the anonymous data member found, or nil if none was found.
const var_decl_sptr
class_or_union::find_anonymous_data_member(const var_decl_sptr& v) const
{
  if (!v->get_name().empty())
    return var_decl_sptr();

  for (data_members::const_iterator it = get_non_static_data_members().begin();
       it != get_non_static_data_members().end();
       ++it)
    {
      if (is_anonymous_data_member(*it))
    if ((*it)->get_pretty_representation(/*internal=*/false, true)
        == v->get_pretty_representation(/*internal=*/false, true))
      return *it;
    }

  return var_decl_sptr();
}

/// Find a given data member.
///
/// This function takes a @ref var_decl as an argument.  If it has a
/// non-empty name, then it tries to find a data member which has the
/// same name as the argument.
///
/// If it has an empty name, then the @ref var_decl is considered as
/// an anonymous data member.  In that case, this function tries to
/// find an anonymous data member which type equals that of the @ref
/// var_decl argument.
///
/// @param v this carries either the name of the data member we need
/// to look for, or the type of the anonymous data member we are
/// looking for.
const var_decl_sptr
class_or_union::find_data_member(const var_decl_sptr& v) const
{
  if (!v)
    return var_decl_sptr();

  if (v->get_name().empty())
    return find_anonymous_data_member(v);

  return find_data_member(v->get_name());
}


/// Get the non-static data members of this @ref class_or_union.
///
/// @return a vector of the non-static data members of this @ref
/// class_or_union.
const class_or_union::data_members&
class_or_union::get_non_static_data_members() const
{return priv_->non_static_data_members_;}

/// Get the static data memebers of this @ref class_or_union.
///
/// @return a vector of the static data members of this @ref
/// class_or_union.
const class_or_union::data_members&
class_or_union::get_static_data_members() const
{return priv_->static_data_members_;}

/// Add a member function.
///
/// @param f the new member function to add.
///
/// @param a the access specifier to use for the new member function.
///
/// @param is_static whether the new member function is static.
///
/// @param is_ctor whether the new member function is a constructor.
///
/// @param is_dtor whether the new member function is a destructor.
///
/// @param is_const whether the new member function is const.
void
class_or_union::add_member_function(method_decl_sptr f,
                    access_specifier a,
                    bool is_static, bool is_ctor,
                    bool is_dtor, bool is_const)
{
  ABG_ASSERT(!has_scope(f));

  scope_decl::add_member_decl(f);

  set_member_function_is_ctor(f, is_ctor);
  set_member_function_is_dtor(f, is_dtor);
  set_member_access_specifier(f, a);
  set_member_is_static(f, is_static);
  set_member_function_is_const(f, is_const);

  priv_->member_functions_.push_back(f);

  // Update the map of linkage name -> member functions.  It's useful,
  // so that class_or_union::find_member_function() can function.
  if (!f->get_linkage_name().empty())
    priv_->mem_fns_map_[f->get_linkage_name()] = f;
}

/// Get the member functions of this @ref class_or_union.
///
/// @return a vector of the member functions of this @ref
/// class_or_union.
const class_or_union::member_functions&
class_or_union::get_member_functions() const
{return priv_->member_functions_;}

/// Find a method, using its linkage name as a key.
///
/// @param linkage_name the linkage name of the method to find.
///
/// @return the method found, or nil if none was found.
const method_decl*
class_or_union::find_member_function(const string& linkage_name) const
{
  return const_cast<class_or_union*>(this)->find_member_function(linkage_name);
}

/// Find a method, using its linkage name as a key.
///
/// @param linkage_name the linkage name of the method to find.
///
/// @return the method found, or nil if none was found.
method_decl*
class_or_union::find_member_function(const string& linkage_name)
{
  string_mem_fn_sptr_map_type::const_iterator i =
    priv_->mem_fns_map_.find(linkage_name);
  if (i == priv_->mem_fns_map_.end())
    return 0;
  return i->second.get();
}

/// Find a method, using its linkage name as a key.
///
/// @param linkage_name the linkage name of the method to find.
///
/// @return the method found, or nil if none was found.
method_decl_sptr
class_or_union::find_member_function_sptr(const string& linkage_name)
{
  string_mem_fn_sptr_map_type::const_iterator i =
    priv_->mem_fns_map_.find(linkage_name);
  if (i == priv_->mem_fns_map_.end())
    return 0;
  return i->second;
}

/// Find a method (member function) using its signature (pretty
/// representation) as a key.
///
/// @param s the signature of the method.
///
/// @return the method found, or nil if none was found.
const method_decl*
class_or_union::find_member_function_from_signature(const string& s) const
{
  return const_cast<class_or_union*>(this)->find_member_function_from_signature(s);
}

/// Find a method (member function) using its signature (pretty
/// representation) as a key.
///
/// @param s the signature of the method.
///
/// @return the method found, or nil if none was found.
method_decl*
class_or_union::find_member_function_from_signature(const string& s)
{
  string_mem_fn_ptr_map_type::const_iterator i =
    priv_->signature_2_mem_fn_map_.find(s);
  if (i == priv_->signature_2_mem_fn_map_.end())
    return 0;
  return i->second;
}

/// Get the member function templates of this class.
///
/// @return a vector of the member function templates of this class.
const member_function_templates&
class_or_union::get_member_function_templates() const
{return priv_->member_function_templates_;}

/// Get the member class templates of this class.
///
/// @return a vector of the member class templates of this class.
const member_class_templates&
class_or_union::get_member_class_templates() const
{return priv_->member_class_templates_;}

/// Append a member function template to the @ref class_or_union.
///
/// @param m the member function template to append.
void
class_or_union::add_member_function_template(member_function_template_sptr m)
{
  decl_base* c = m->as_function_tdecl()->get_scope();
  /// TODO: use our own ABG_ASSERTion facility that adds a meaningful
  /// error message or something like a structured error.
  priv_->member_function_templates_.push_back(m);
  if (!c)
    scope_decl::add_member_decl(m->as_function_tdecl());
}

/// Append a member class template to the @ref class_or_union.
///
/// @param m the member function template to append.
void
class_or_union::add_member_class_template(member_class_template_sptr m)
{
  decl_base* c = m->as_class_tdecl()->get_scope();
  /// TODO: use our own ABG_ASSERTion facility that adds a meaningful
  /// error message or something like a structured error.
  m->set_scope(this);
  priv_->member_class_templates_.push_back(m);
  if (!c)
    scope_decl::add_member_decl(m->as_class_tdecl());
}

///@return true iff the current instance has no member.
bool
class_or_union::has_no_member() const
{
  return (get_member_types().empty()
      && priv_->data_members_.empty()
      && priv_->member_functions_.empty()
      && priv_->member_function_templates_.empty()
      && priv_->member_class_templates_.empty());
}

/// Insert a data member to this @ref class_or_union type.
///
/// @param d the data member to insert.
///
/// @return the decl @p that got inserted.
decl_base_sptr
class_or_union::insert_member_decl(decl_base_sptr d)
{
  if (var_decl_sptr v = dynamic_pointer_cast<var_decl>(d))
    {
      add_data_member(v, public_access,
              /*is_laid_out=*/false,
              /*is_static=*/true,
              /*offset_in_bits=*/0);
      d = v;
    }
  else if (method_decl_sptr f = dynamic_pointer_cast<method_decl>(d))
    add_member_function(f, public_access,
            /*is_static=*/false,
            /*is_ctor=*/false,
            /*is_dtor=*/false,
            /*is_const=*/false);
  else if (member_function_template_sptr f =
       dynamic_pointer_cast<member_function_template>(d))
    add_member_function_template(f);
  else if (member_class_template_sptr c =
       dynamic_pointer_cast<member_class_template>(d))
    add_member_class_template(c);
  else
    scope_decl::add_member_decl(d);

  return d;
}

/// Equality operator.
///
/// @param other the other @ref class_or_union to compare against.
///
/// @return true iff @p other equals the current @ref class_or_union.
bool
class_or_union::operator==(const decl_base& other) const
{
  const class_or_union* op = dynamic_cast<const class_or_union*>(&other);
  if (!op)
    return false;

  // If this is a decl-only type (and thus with no canonical type),
  // use the canonical type of the definition, if any.
  const class_or_union *l = 0;
  if (get_is_declaration_only())
    l = dynamic_cast<const class_or_union*>(get_naked_definition_of_declaration());
  if (l == 0)
    l = this;

  // Likewise for the other class.
  const class_or_union *r = 0;
  if (op->get_is_declaration_only())
    r = dynamic_cast<const class_or_union*>(op->get_naked_definition_of_declaration());
  if (r == 0)
    r = op;

  return try_canonical_compare(l, r);
}

/// Equality operator.
///
/// @param other the other @ref class_or_union to compare against.
///
/// @return true iff @p other equals the current @ref class_or_union.
bool
class_or_union::operator==(const type_base& other) const
{
  const decl_base* o = dynamic_cast<const decl_base*>(&other);
  if (!o)
    return false;
  return *this == *o;
}

/// Equality operator.
///
/// @param other the other @ref class_or_union to compare against.
///
/// @return true iff @p other equals the current @ref class_or_union.
bool
class_or_union::operator==(const class_or_union& other) const
{
  const decl_base& o = other;
  return class_or_union::operator==(o);
}

/// Compares two instances of @ref class_or_union.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff it's non-null and if the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const class_or_union& l, const class_or_union& r, change_kind* k)
{
  // if one of the classes is declaration-only, look through it to
  // get its definition.
  bool l_is_decl_only = l.get_is_declaration_only();
  bool r_is_decl_only = r.get_is_declaration_only();
  if (l_is_decl_only || r_is_decl_only)
    {
      const class_or_union* def1 = l_is_decl_only
    ? is_class_or_union_type(l.get_naked_definition_of_declaration())
    : &l;

      const class_or_union* def2 = r_is_decl_only
    ? is_class_or_union_type(r.get_naked_definition_of_declaration())
    : &r;

      if (!def1 || !def2)
    {
      if (!l.get_is_anonymous()
          && !r.get_is_anonymous()
          && l_is_decl_only && r_is_decl_only
          && comparison::filtering::is_decl_only_class_with_size_change(l, r))
        // The two decl-only classes differ from their size.  A
        // true decl-only class should not have a size property to
        // begin with.  This comes from a DWARF oddity and can
        // results in a false positive, so let's not consider that
        // change.
        return true;

      if (l.get_environment().decl_only_class_equals_definition()
          && !is_anonymous_or_typedef_named(l)
          && !is_anonymous_or_typedef_named(r))
        {
          const interned_string& q1 = l.get_scoped_name();
          const interned_string& q2 = r.get_scoped_name();
          if (q1 == q2)
        // Not using RETURN(true) here, because that causes
        // performance issues.  We don't need to do
        // l.priv_->unmark_as_being_compared({l,r}) here because
        // we haven't marked l or r as being compared yet, and
        // doing so has a peformance cost that shows up on
        // performance profiles for *big* libraries.
        return true;
          else
        {
          if (k)
            *k |= LOCAL_TYPE_CHANGE_KIND;
          // Not using RETURN(true) here, because that causes
          // performance issues.  We don't need to do
          // l.priv_->unmark_as_being_compared({l,r}) here because
          // we haven't marked l or r as being compared yet, and
          // doing so has a peformance cost that shows up on
          // performance profiles for *big* libraries.
          ABG_RETURN_FALSE;
        }
        }
      else // A decl-only class is considered different from a
           // class definition of the same name.
        {
          if (!!def1 != !!def2)
        {
          if (k)
            *k |= LOCAL_TYPE_CHANGE_KIND;
          ABG_RETURN_FALSE;
        }

          // both definitions are empty
          if (!(l.decl_base::operator==(r)
               && l.type_base::operator==(r)))
        {
          if (k)
            *k |= LOCAL_TYPE_CHANGE_KIND;
          ABG_RETURN_FALSE;
        }

          return true;
        }
    }

      bool val = *def1 == *def2;
      if (!val)
    if (k)
      *k |= LOCAL_TYPE_CHANGE_KIND;
      ABG_RETURN(val);
    }

  // No need to go further if the classes have different names or
  // different size / alignment.
  if (!(l.decl_base::operator==(r) && l.type_base::operator==(r)))
    {
      if (k)
    *k |= LOCAL_TYPE_CHANGE_KIND;
      ABG_RETURN_FALSE;
    }

  if (types_defined_same_linux_kernel_corpus_public(l, r))
    return true;

  //TODO: Maybe remove this (cycle detection and canonical type
  //propagation handling) from here and have it only in the equal
  //overload for class_decl and union_decl because this one ( the
  //equal overload for class_or_union) is just a sub-routine of these
  //two above.
#define RETURN(value)               \
  return return_comparison_result(l, r, value);

  RETURN_TRUE_IF_COMPARISON_CYCLE_DETECTED(l, r);

  mark_types_as_being_compared(l, r);

  bool result = true;

  //compare data_members
  {
    if (l.get_non_static_data_members().size()
    != r.get_non_static_data_members().size())
      {
    result = false;
    if (k)
      *k |= LOCAL_TYPE_CHANGE_KIND;
    else
      RETURN(result);
      }

    for (class_or_union::data_members::const_iterator
       d0 = l.get_non_static_data_members().begin(),
       d1 = r.get_non_static_data_members().begin();
     (d0 != l.get_non_static_data_members().end()
      && d1 != r.get_non_static_data_members().end());
     ++d0, ++d1)
      if (**d0 != **d1)
    {
      result = false;
      if (k)
        {
          // Report any representation change as being local.
          if (!types_have_similar_structure((*d0)->get_type(),
                        (*d1)->get_type())
          || (*d0)->get_type() == (*d1)->get_type())
        *k |= LOCAL_TYPE_CHANGE_KIND;
          else
        *k |= SUBTYPE_CHANGE_KIND;
        }
      else
        RETURN(result);
    }
  }

  // Do not compare member functions.  DWARF does not necessarily
  // all the member functions, be they virtual or not, in all
  // translation units.  So we cannot have a clear view of them, per
  // class

  // compare member function templates
  {
    if (l.get_member_function_templates().size()
    != r.get_member_function_templates().size())
      {
    result = false;
    if (k)
      *k |= LOCAL_NON_TYPE_CHANGE_KIND;
    else
      RETURN(result);
      }

    for (member_function_templates::const_iterator
       fn_tmpl_it0 = l.get_member_function_templates().begin(),
       fn_tmpl_it1 = r.get_member_function_templates().begin();
     fn_tmpl_it0 != l.get_member_function_templates().end()
       &&  fn_tmpl_it1 != r.get_member_function_templates().end();
     ++fn_tmpl_it0, ++fn_tmpl_it1)
      if (**fn_tmpl_it0 != **fn_tmpl_it1)
    {
      result = false;
      if (k)
        {
          *k |= LOCAL_NON_TYPE_CHANGE_KIND;
          break;
        }
      else
        RETURN(result);
    }
  }

  // compare member class templates
  {
    if (l.get_member_class_templates().size()
    != r.get_member_class_templates().size())
      {
    result = false;
    if (k)
      *k |= LOCAL_NON_TYPE_CHANGE_KIND;
    else
      RETURN(result);
      }

    for (member_class_templates::const_iterator
       cl_tmpl_it0 = l.get_member_class_templates().begin(),
       cl_tmpl_it1 = r.get_member_class_templates().begin();
     cl_tmpl_it0 != l.get_member_class_templates().end()
       &&  cl_tmpl_it1 != r.get_member_class_templates().end();
     ++cl_tmpl_it0, ++cl_tmpl_it1)
      if (**cl_tmpl_it0 != **cl_tmpl_it1)
    {
      result = false;
      if (k)
        {
          *k |= LOCAL_NON_TYPE_CHANGE_KIND;
          break;
        }
      else
        RETURN(result);
    }
  }

  RETURN(result);
#undef RETURN
}


/// Copy a method of a @ref class_or_union into a new @ref
/// class_or_union.
///
/// @param t the @ref class_or_union into which the method is to be copied.
///
/// @param method the method to copy into @p t.
///
/// @return the resulting newly copied method.
method_decl_sptr
copy_member_function(class_or_union_sptr t,
             const method_decl_sptr& method)
{return copy_member_function(t, method.get());}


/// Copy a method of a @ref class_or_union into a new @ref
/// class_or_union.
///
/// @param t the @ref class_or_union into which the method is to be copied.
///
/// @param method the method to copy into @p t.
///
/// @return the resulting newly copied method.
method_decl_sptr
copy_member_function(class_or_union_sptr t, const method_decl* method)
{
  ABG_ASSERT(t);
  ABG_ASSERT(method);

  method_type_sptr old_type = method->get_type();
  ABG_ASSERT(old_type);
  method_type_sptr new_type(new method_type(old_type->get_return_type(),
                        t,
                        old_type->get_parameters(),
                        old_type->get_is_const(),
                        old_type->get_size_in_bits(),
                        old_type->get_alignment_in_bits()));
  t->get_translation_unit()->bind_function_type_life_time(new_type);

  method_decl_sptr
    new_method(new method_decl(method->get_name(),
                   new_type,
                   method->is_declared_inline(),
                   method->get_location(),
                   method->get_linkage_name(),
                   method->get_visibility(),
                   method->get_binding()));
  new_method->set_symbol(method->get_symbol());

  if (class_decl_sptr class_type = is_class_type(t))
    class_type->add_member_function(new_method,
                    get_member_access_specifier(*method),
                    get_member_function_is_virtual(*method),
                    get_member_function_vtable_offset(*method),
                    get_member_is_static(*method),
                    get_member_function_is_ctor(*method),
                    get_member_function_is_dtor(*method),
                    get_member_function_is_const(*method));
  else
    t->add_member_function(new_method,
               get_member_access_specifier(*method),
               get_member_is_static(*method),
               get_member_function_is_ctor(*method),
               get_member_function_is_dtor(*method),
               get_member_function_is_const(*method));
  return new_method;
}

/// Copy a data member of a @ref class_or_union into a new @ref
/// class_or_union.
///
/// @param t the @ref class_or_union into which the data member is to
/// be copied.
///
/// @param variable the data member to copy into @p t.
///
/// @return the resulting newly copied method.
var_decl_sptr
copy_member_variable(class_or_union_sptr t, const var_decl* variable)
{
  ABG_ASSERT(variable);
  ABG_ASSERT(is_data_member(variable));
  ABG_ASSERT(t);
  ABG_ASSERT(!t->find_data_member(variable->get_name()));

  type_base_sptr old_type = variable->get_type();

  var_decl_sptr new_variable(new var_decl(variable->get_name(),
                      old_type,
                      variable->get_location(),
                      variable->get_linkage_name(),
                      variable->get_visibility(),
                      variable->get_binding()));

  size_t offset_in_bits = 0;
  if (get_data_member_is_laid_out(*variable))
    offset_in_bits = get_data_member_offset(*variable);

  t->add_data_member(new_variable,
             get_member_access_specifier(*variable),
             get_data_member_is_laid_out(*variable),
             get_member_is_static(*variable),
             offset_in_bits);

  return new_variable;
}

/// Copy a data member of a @ref class_or_union into a new @ref
/// class_or_union.
///
/// @param t the @ref class_or_union into which the data member is to
/// be copied.
///
/// @param variable the data member to copy into @p t.
///
/// @return the resulting newly copied method.
var_decl_sptr
copy_member_variable(class_or_union_sptr t, const var_decl_sptr& variable)
{return copy_member_variable(t, variable.get());}

/// Copy a data member of a @ref class_or_union into a new @ref
/// class_or_union.
///
/// @param t the @ref class_or_union into which the data member is to
/// be copied.
///
/// @param variable the data member to copy into @p t.
///
/// @return the resulting newly copied method.
var_decl_sptr
copy_member_variable(class_decl_sptr t, const var_decl_sptr& variable)
{return copy_member_variable(static_pointer_cast<class_or_union>(t), variable);}
// </class_or_union definitions>

// <class_decl definitions>

static void
sort_virtual_member_functions(class_decl::member_functions& mem_fns);

/// The private data for the class_decl type.
struct class_decl::priv
{
  base_specs                    bases_;
  unordered_map<string, base_spec_sptr> bases_map_;
  member_functions              virtual_mem_fns_;
  virtual_mem_fn_map_type           virtual_mem_fns_map_;
  bool                      is_struct_;

  priv()
    : is_struct_(false)
  {}

  priv(bool is_struct, class_decl::base_specs& bases)
    : bases_(bases),
      is_struct_(is_struct)
  {
  }

  priv(bool is_struct)
    : is_struct_(is_struct)
  {}
};// end struct class_decl::priv

/// A Constructor for instances of \ref class_decl
///
/// @param env the environment we are operating from.
///
/// @param name the identifier of the class.
///
/// @param size_in_bits the size of an instance of class_decl, expressed
/// in bits
///
/// @param align_in_bits the alignment of an instance of class_decl,
/// expressed in bits.
///
/// @param locus the source location of declaration point this class.
///
/// @param vis the visibility of instances of class_decl.
///
/// @param bases the vector of base classes for this instance of class_decl.
///
/// @param mbrs the vector of member types of this instance of
/// class_decl.
///
/// @param data_mbrs the vector of data members of this instance of
/// class_decl.
///
/// @param mbr_fns the vector of member functions of this instance of
/// class_decl.
class_decl::class_decl(const environment& env, const string& name,
               size_t size_in_bits, size_t align_in_bits,
               bool is_struct, const location& locus,
               visibility vis, base_specs& bases,
               member_types& mbr_types,
               data_members& data_mbrs,
               member_functions& mbr_fns)
  : type_or_decl_base(env,
              CLASS_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE
              | ABSTRACT_SCOPE_TYPE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(env, name, locus, name, vis),
    type_base(env, size_in_bits, align_in_bits),
    class_or_union(env, name, size_in_bits, align_in_bits,
           locus, vis, mbr_types, data_mbrs, mbr_fns),
    priv_(new priv(is_struct, bases))
{
  runtime_type_instance(this);
}

/// A Constructor for instances of @ref class_decl
///
/// @param env the environment we are operating from.
///
/// @param name the identifier of the class.
///
/// @param size_in_bits the size of an instance of class_decl, expressed
/// in bits
///
/// @param align_in_bits the alignment of an instance of class_decl,
/// expressed in bits.
///
/// @param locus the source location of declaration point this class.
///
/// @param vis the visibility of instances of class_decl.
///
/// @param bases the vector of base classes for this instance of class_decl.
///
/// @param mbrs the vector of member types of this instance of
/// class_decl.
///
/// @param data_mbrs the vector of data members of this instance of
/// class_decl.
///
/// @param mbr_fns the vector of member functions of this instance of
/// class_decl.
///
/// @param is_anonymous whether the newly created instance is
/// anonymous.
class_decl::class_decl(const environment& env, const string& name,
               size_t size_in_bits, size_t align_in_bits,
               bool is_struct, const location& locus,
               visibility vis, base_specs& bases,
               member_types& mbr_types, data_members& data_mbrs,
               member_functions& mbr_fns, bool is_anonymous)
  : type_or_decl_base(env,
              CLASS_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE
              | ABSTRACT_SCOPE_TYPE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(env, name, locus,
          // If the class is anonymous then by default it won't
          // have a linkage name.  Also, the anonymous class does
          // have an internal-only unique name that is generally
          // not taken into account when comparing classes; such a
          // unique internal-only name, when used as a linkage
          // name might introduce spurious comparison false
          // negatives.
          /*linkage_name=*/is_anonymous ? string() : name,
          vis),
    type_base(env, size_in_bits, align_in_bits),
    class_or_union(env, name, size_in_bits, align_in_bits,
           locus, vis, mbr_types, data_mbrs, mbr_fns),
    priv_(new priv(is_struct, bases))
{
  runtime_type_instance(this);
  set_is_anonymous(is_anonymous);
}

/// A constructor for instances of class_decl.
///
/// @param env the environment we are operating from.
///
/// @param name the name of the class.
///
/// @param size_in_bits the size of an instance of class_decl, expressed
/// in bits
///
/// @param align_in_bits the alignment of an instance of class_decl,
/// expressed in bits.
///
/// @param locus the source location of declaration point this class.
///
/// @param vis the visibility of instances of class_decl.
class_decl::class_decl(const environment& env, const string& name,
               size_t size_in_bits, size_t align_in_bits,
               bool is_struct, const location& locus,
               visibility vis)
  : type_or_decl_base(env,
              CLASS_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE
              | ABSTRACT_SCOPE_TYPE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(env, name, locus, name, vis),
    type_base(env, size_in_bits, align_in_bits),
    class_or_union(env, name, size_in_bits, align_in_bits,
           locus, vis),
    priv_(new priv(is_struct))
{
  runtime_type_instance(this);
}

/// A constructor for instances of @ref class_decl.
///
/// @param env the environment we are operating from.
///
/// @param name the name of the class.
///
/// @param size_in_bits the size of an instance of class_decl, expressed
/// in bits
///
/// @param align_in_bits the alignment of an instance of class_decl,
/// expressed in bits.
///
/// @param locus the source location of declaration point this class.
///
/// @param vis the visibility of instances of class_decl.
///
/// @param is_anonymous whether the newly created instance is
/// anonymous.
class_decl:: class_decl(const environment& env, const string& name,
            size_t size_in_bits, size_t align_in_bits,
            bool is_struct, const location& locus,
            visibility vis, bool is_anonymous)
  : type_or_decl_base(env,
              CLASS_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE
              | ABSTRACT_SCOPE_TYPE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(env, name, locus,
          // If the class is anonymous then by default it won't
          // have a linkage name.  Also, the anonymous class does
          // have an internal-only unique name that is generally
          // not taken into account when comparing classes; such a
          // unique internal-only name, when used as a linkage
          // name might introduce spurious comparison false
          // negatives.
          /*linkage_name=*/ is_anonymous ? string() : name,
          vis),
    type_base(env, size_in_bits, align_in_bits),
    class_or_union(env, name, size_in_bits, align_in_bits,
           locus, vis),
  priv_(new priv(is_struct))
{
  runtime_type_instance(this);
  set_is_anonymous(is_anonymous);
}

/// A constuctor for instances of class_decl that represent a
/// declaration without definition.
///
/// @param env the environment we are operating from.
///
/// @param name the name of the class.
///
/// @param is_declaration_only a boolean saying whether the instance
/// represents a declaration only, or not.
class_decl::class_decl(const environment& env, const string& name,
               bool is_struct, bool is_declaration_only)
  : type_or_decl_base(env,
              CLASS_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE
              | ABSTRACT_SCOPE_TYPE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(env, name, location(), name),
    type_base(env, 0, 0),
    class_or_union(env, name, is_declaration_only),
    priv_(new priv(is_struct))
{
  runtime_type_instance(this);
}

/// This method is invoked automatically right after the current
/// instance of @ref class_decl has been canonicalized.
///
/// Currently, the only thing it does is to sort the virtual member
/// functions vector.
void
class_decl::on_canonical_type_set()
{
  sort_virtual_mem_fns();

  for (class_decl::virtual_mem_fn_map_type::iterator i =
     priv_->virtual_mem_fns_map_.begin();
       i != priv_->virtual_mem_fns_map_.end();
       ++i)
    sort_virtual_member_functions(i->second);
}

/// Set the "is-struct" flag of the class.
///
/// @param f the new value of the flag.
void
class_decl::is_struct(bool f)
{priv_->is_struct_ = f;}

/// Test if the class is a struct.
///
/// @return true iff the class is a struct.
bool
class_decl::is_struct() const
{return priv_->is_struct_;}

/// Add a base specifier to this class.
///
/// @param b the new base specifier.
void
class_decl::add_base_specifier(base_spec_sptr b)
{
  priv_->bases_.push_back(b);
  priv_->bases_map_[b->get_base_class()->get_qualified_name()] = b;
}

/// Get the base specifiers for this class.
///
/// @return a vector of the base specifiers.
const class_decl::base_specs&
class_decl::get_base_specifiers() const
{return priv_->bases_;}

/// Find a base class of a given qualified name for the current class.
///
/// @param qualified_name the qualified name of the base class to look for.
///
/// @return a pointer to the @ref class_decl that represents the base
/// class of name @p qualified_name, if found.
class_decl_sptr
class_decl::find_base_class(const string& qualified_name) const
{
  unordered_map<string, base_spec_sptr>::iterator i =
    priv_->bases_map_.find(qualified_name);

  if (i != priv_->bases_map_.end())
    return i->second->get_base_class();

  return class_decl_sptr();
}

/// Get the virtual member functions of this class.
///
/// @param return a vector of the virtual member functions of this
/// class.
const class_decl::member_functions&
class_decl::get_virtual_mem_fns() const
{return priv_->virtual_mem_fns_;}

/// Get the map that associates a virtual table offset to the virtual
/// member functions with that virtual table offset.
///
/// Usually, there should be a 1:1 mapping between a given vtable
/// offset and virtual member functions of that vtable offset.  But
/// because of some implementation details, there can be several C++
/// destructor functions that are *generated* by compilers, for a
/// given destructor that is defined in the source code.  If the
/// destructor is virtual then those generated functions have some
/// DWARF attributes in common with the constructor that the user
/// actually defined in its source code.  Among those attributes are
/// the vtable offset of the destructor.
///
/// @return the map that associates a virtual table offset to the
/// virtual member functions with that virtual table offset.
const class_decl::virtual_mem_fn_map_type&
class_decl::get_virtual_mem_fns_map() const
{return priv_->virtual_mem_fns_map_;}

/// Sort the virtual member functions by their virtual index.
void
class_decl::sort_virtual_mem_fns()
{sort_virtual_member_functions(priv_->virtual_mem_fns_);}

/// Getter of the pretty representation of the current instance of
/// @ref class_decl.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
///
/// @param qualified_name if true, names emitted in the pretty
/// representation are fully qualified.
///
/// @return the pretty representaion for a class_decl.
string
class_decl::get_pretty_representation(bool internal,
                      bool qualified_name) const
{
  string cl = "class ";
  if (!internal && is_struct())
    cl = "struct ";

  // When computing the pretty representation for internal purposes,
  // if an anonymous class is named by a typedef, then consider that
  // it has a name, which is the typedef name.
  if (get_is_anonymous())
    {
      if (internal && !get_name().empty())
    return cl + get_type_name(this, qualified_name, /*internal=*/true);
      return get_class_or_union_flat_representation(this, "",
                            /*one_line=*/true,
                            internal);

    }

  string result = cl;
  if (qualified_name)
    result += get_qualified_name(internal);
  else
    result += get_name();

  return result;
}

decl_base_sptr
class_decl::insert_member_decl(decl_base_sptr d)
{
  if (method_decl_sptr f = dynamic_pointer_cast<method_decl>(d))
    add_member_function(f, public_access,
            /*is_virtual=*/false,
            /*vtable_offset=*/0,
            /*is_static=*/false,
            /*is_ctor=*/false,
            /*is_dtor=*/false,
            /*is_const=*/false);
  else
    d = class_or_union::insert_member_decl(d);

  return d;
}

/// The private data structure of class_decl::base_spec.
struct class_decl::base_spec::priv
{
  class_decl_wptr   base_class_;
  long          offset_in_bits_;
  bool          is_virtual_;

  priv(const class_decl_sptr& cl,
       long offset_in_bits,
       bool is_virtual)
    : base_class_(cl),
      offset_in_bits_(offset_in_bits),
      is_virtual_(is_virtual)
  {}
};

/// Constructor for base_spec instances.
///
/// @param base the base class to consider
///
/// @param a the access specifier of the base class.
///
/// @param offset_in_bits if positive or null, represents the offset
/// of the base in the layout of its containing type..  If negative,
/// means that the current base is not laid out in its containing type.
///
/// @param is_virtual if true, means that the current base class is
/// virtual in it's containing type.
class_decl::base_spec::base_spec(const class_decl_sptr& base,
                 access_specifier a,
                 long offset_in_bits,
                 bool is_virtual)
  : type_or_decl_base(base->get_environment(),
              ABSTRACT_DECL_BASE),
    decl_base(base->get_environment(), base->get_name(), base->get_location(),
          base->get_linkage_name(), base->get_visibility()),
    member_base(a),
    priv_(new priv(base, offset_in_bits, is_virtual))
{
  runtime_type_instance(this);
  set_qualified_name(base->get_qualified_name());
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
class_decl::base_spec::hash_value() const
{
  hash_t h = set_or_get_cached_hash_value(this);
  return h;
}

/// Get the base class referred to by the current base class
/// specifier.
///
/// @return the base class.
class_decl_sptr
class_decl::base_spec::get_base_class() const
{return priv_->base_class_.lock();}

/// Getter of the "is-virtual" proprerty of the base class specifier.
///
/// @return true iff this specifies a virtual base class.
bool
class_decl::base_spec::get_is_virtual() const
{return priv_->is_virtual_;}

/// Getter of the offset of the base.
///
/// @return the offset of the base.
long
class_decl::base_spec::get_offset_in_bits() const
{return priv_->offset_in_bits_;}

/// Traverses an instance of @ref class_decl::base_spec, visiting all
/// the sub-types and decls that it might contain.
///
/// @param v the visitor that is used to visit every IR sub-node of
/// the current node.
///
/// @return true if either
///  - all the children nodes of the current IR node were traversed
///    and the calling code should keep going with the traversing.
///  - or the current IR node is already being traversed.
/// Otherwise, returning false means that the calling code should not
/// keep traversing the tree.
bool
class_decl::base_spec::traverse(ir_node_visitor& v)
{
  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      get_base_class()->traverse(v);
      visiting(false);
    }

  return v.visit_end(this);
}

/// Constructor for base_spec instances.
///
/// Note that this constructor is for clients that don't support RTTI
/// and that have a base class of type_base, but of dynamic type
/// class_decl.
///
/// @param base the base class to consider.  Must be a pointer to an
/// instance of class_decl
///
/// @param a the access specifier of the base class.
///
/// @param offset_in_bits if positive or null, represents the offset
/// of the base in the layout of its containing type..  If negative,
/// means that the current base is not laid out in its containing type.
///
/// @param is_virtual if true, means that the current base class is
/// virtual in it's containing type.
class_decl::base_spec::base_spec(const type_base_sptr& base,
                 access_specifier a,
                 long offset_in_bits,
                 bool is_virtual)
  : type_or_decl_base(base->get_environment(),
              ABSTRACT_DECL_BASE),
    decl_base(base->get_environment(), get_type_declaration(base)->get_name(),
          get_type_declaration(base)->get_location(),
          get_type_declaration(base)->get_linkage_name(),
          get_type_declaration(base)->get_visibility()),
    member_base(a),
    priv_(new priv(dynamic_pointer_cast<class_decl>(base),
           offset_in_bits,
           is_virtual))
{
  runtime_type_instance(this);
}

class_decl::base_spec::~base_spec() = default;

/// Compares two instances of @ref class_decl::base_spec.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const class_decl::base_spec& l,
       const class_decl::base_spec& r,
       change_kind* k)
{
  if (!l.member_base::operator==(r))
    {
      if (k)
    *k |= LOCAL_TYPE_CHANGE_KIND;
      ABG_RETURN_FALSE;
    }

  ABG_RETURN((*l.get_base_class() == *r.get_base_class()));
}

/// Comparison operator for @ref class_decl::base_spec.
///
/// @param other the instance of @ref class_decl::base_spec to compare
/// against.
///
/// @return true if the current instance of @ref class_decl::base_spec
/// equals @p other.
bool
class_decl::base_spec::operator==(const decl_base& other) const
{
  const class_decl::base_spec* o =
    dynamic_cast<const class_decl::base_spec*>(&other);

  if (!o)
    return false;

  return equals(*this, *o, 0);
}

/// Comparison operator for @ref class_decl::base_spec.
///
/// @param other the instance of @ref class_decl::base_spec to compare
/// against.
///
/// @return true if the current instance of @ref class_decl::base_spec
/// equals @p other.
bool
class_decl::base_spec::operator==(const member_base& other) const
{
  const class_decl::base_spec* o =
    dynamic_cast<const class_decl::base_spec*>(&other);
  if (!o)
    return false;

  return operator==(static_cast<const decl_base&>(*o));
}

mem_fn_context_rel::~mem_fn_context_rel()
{
}

/// A constructor for instances of method_decl.
///
/// @param name the name of the method.
///
/// @param type the type of the method.
///
/// @param declared_inline whether the method was
/// declared inline or not.
///
/// @param locus the source location of the method.
///
/// @param linkage_name the mangled name of the method.
///
/// @param vis the visibility of the method.
///
/// @param bind the binding of the method.
method_decl::method_decl(const string&      name,
             method_type_sptr   type,
             bool           declared_inline,
             const location&    locus,
             const string&      linkage_name,
             visibility     vis,
             binding        bind)
  : type_or_decl_base(type->get_environment(),
              METHOD_DECL
              | ABSTRACT_DECL_BASE
              |FUNCTION_DECL),
    decl_base(type->get_environment(), name, locus, linkage_name, vis),
    function_decl(name, static_pointer_cast<function_type>(type),
          declared_inline, locus, linkage_name, vis, bind)
{
  runtime_type_instance(this);
  set_context_rel(new mem_fn_context_rel(0));
  set_member_function_is_const(*this, type->get_is_const());
}

/// A constructor for instances of method_decl.
///
/// @param name the name of the method.
///
/// @param type the type of the method.  Must be an instance of
/// method_type.
///
/// @param declared_inline whether the method was
/// declared inline or not.
///
/// @param locus the source location of the method.
///
/// @param linkage_name the mangled name of the method.
///
/// @param vis the visibility of the method.
///
/// @param bind the binding of the method.
method_decl::method_decl(const string&      name,
             function_type_sptr type,
             bool           declared_inline,
             const location&    locus,
             const string&      linkage_name,
             visibility     vis,
             binding        bind)
  : type_or_decl_base(type->get_environment(),
              METHOD_DECL
              | ABSTRACT_DECL_BASE
              | FUNCTION_DECL),
    decl_base(type->get_environment(), name, locus, linkage_name, vis),
    function_decl(name, static_pointer_cast<function_type>
          (dynamic_pointer_cast<method_type>(type)),
          declared_inline, locus, linkage_name, vis, bind)
{
  runtime_type_instance(this);
  set_context_rel(new mem_fn_context_rel(0));
}

/// A constructor for instances of method_decl.
///
/// @param name the name of the method.
///
/// @param type the type of the method.  Must be an instance of
/// method_type.
///
/// @param declared_inline whether the method was
/// declared inline or not.
///
/// @param locus the source location of the method.
///
/// @param linkage_name the mangled name of the method.
///
/// @param vis the visibility of the method.
///
/// @param bind the binding of the method.
method_decl::method_decl(const string&      name,
             type_base_sptr type,
             bool           declared_inline,
             const location&    locus,
             const string&      linkage_name,
             visibility     vis,
             binding        bind)
  : type_or_decl_base(type->get_environment(),
              METHOD_DECL
              | ABSTRACT_DECL_BASE
              | FUNCTION_DECL),
    decl_base(type->get_environment(), name, locus, linkage_name, vis),
    function_decl(name, static_pointer_cast<function_type>
          (dynamic_pointer_cast<method_type>(type)),
          declared_inline, locus, linkage_name, vis, bind)
{
  runtime_type_instance(this);
  set_context_rel(new mem_fn_context_rel(0));
}

/// Set the linkage name of the method.
///
/// @param l the new linkage name of the method.
void
method_decl::set_linkage_name(const string& l)
{
  string old_lname = get_linkage_name();
  decl_base::set_linkage_name(l);
  // Update the linkage_name -> member function map of the containing
  // class declaration.
  if (!l.empty())
    {
      method_type_sptr t = get_type();
      class_or_union_sptr cl = t->get_class_type();
      method_decl_sptr m(this, sptr_utils::noop_deleter());
      cl->priv_->mem_fns_map_[l] = m;
      if (!old_lname.empty() && l != old_lname)
    {
      if (method_decl_sptr m = cl->find_member_function_sptr(old_lname))
        {
          ABG_ASSERT(m.get() == this);
          cl->priv_->mem_fns_map_.erase(old_lname);
        }
    }
    }
}

method_decl::~method_decl()
{}

const method_type_sptr
method_decl::get_type() const
{
  method_type_sptr result;
  if (function_decl::get_type())
    result = dynamic_pointer_cast<method_type>(function_decl::get_type());
  return result;
}

/// Set the containing class of a method_decl.
///
/// @param scope the new containing class_decl.
void
method_decl::set_scope(scope_decl* scope)
{
  if (!get_context_rel())
    set_context_rel(new mem_fn_context_rel(scope));
  else
    get_context_rel()->set_scope(scope);
}

/// Equality operator for @ref method_decl_sptr.
///
/// This is a deep equality operator, as it compares the @ref
/// method_decl that is pointed-to by the smart pointer.
///
/// @param l the left-hand side argument of the equality operator.
///
/// @param r the righ-hand side argument of the equality operator.
///
/// @return true iff @p l equals @p r.
bool
operator==(const method_decl_sptr& l, const method_decl_sptr& r)
{
  if (l.get() == r.get())
    return true;
  if (!!l != !!r)
    return false;

  return *l == *r;
}

/// Inequality operator for @ref method_decl_sptr.
///
/// This is a deep equality operator, as it compares the @ref
/// method_decl that is pointed-to by the smart pointer.
///
/// @param l the left-hand side argument of the equality operator.
///
/// @param r the righ-hand side argument of the equality operator.
///
/// @return true iff @p l differs from @p r.
bool
operator!=(const method_decl_sptr& l, const method_decl_sptr& r)
{return !operator==(l, r);}

/// Test if a function_decl is actually a method_decl.
///
///@param d the @ref function_decl to consider.
///
/// @return the method_decl sub-object of @p d if inherits
/// a method_decl type.
method_decl*
is_method_decl(const type_or_decl_base *d)
{
  return dynamic_cast<method_decl*>
    (const_cast<type_or_decl_base*>(d));
}

/// Test if a function_decl is actually a method_decl.
///
///@param d the @ref function_decl to consider.
///
/// @return the method_decl sub-object of @p d if inherits
/// a method_decl type.
method_decl*
is_method_decl(const type_or_decl_base&d)
{return is_method_decl(&d);}

/// Test if a function_decl is actually a method_decl.
///
///@param d the @ref function_decl to consider.
///
/// @return the method_decl sub-object of @p d if inherits
/// a method_decl type.
method_decl_sptr
is_method_decl(const type_or_decl_base_sptr& d)
{return dynamic_pointer_cast<method_decl>(d);}

/// A "less than" functor to sort a vector of instances of
/// method_decl that are virtual.
struct virtual_member_function_less_than
{
  /// The less than operator.  First, it sorts the methods by their
  /// vtable index.  If they have the same vtable index, it sorts them
  /// by the name of their ELF symbol.  If they don't have elf
  /// symbols, it sorts them by considering their pretty
  /// representation.
  ///
  ///  Note that this method expects virtual methods.
  ///
  /// @param f the first method to consider.
  ///
  /// @param s the second method to consider.
  ///
  /// @return true if method @p is less than method @s.
  bool
  operator()(const method_decl& f,
         const method_decl& s)
  {
    ABG_ASSERT(get_member_function_is_virtual(f));
    ABG_ASSERT(get_member_function_is_virtual(s));

    ssize_t f_offset = get_member_function_vtable_offset(f);
    ssize_t s_offset = get_member_function_vtable_offset(s);
    if (f_offset != s_offset) return f_offset < s_offset;

    string fn, sn;
    // Try the linkage names (important for destructors).
    fn = f.get_linkage_name();
    sn = s.get_linkage_name();
    if (fn != sn) return fn < sn;

    // If the functions have symbols, then compare their symbol-id
    // string.
    elf_symbol_sptr f_sym = f.get_symbol();
    elf_symbol_sptr s_sym = s.get_symbol();
    if ((!f_sym) != (!s_sym)) return !f_sym;
    if (f_sym && s_sym)
      {
    fn = f_sym->get_id_string();
    sn = s_sym->get_id_string();
    if (fn != sn) return fn < sn;
      }

    // None of the functions have symbols or linkage names that
    // distinguish them, so compare their pretty representation.
    fn = f.get_pretty_representation();
    sn = s.get_pretty_representation();
    if (fn != sn) return fn < sn;

    /// If it's just the file paths that are different then sort them
    /// too.
    string fn_filepath, sn_filepath;
    unsigned line = 0, column = 0;
    location fn_loc = f.get_location(), sn_loc = s.get_location();
    if (fn_loc)
      fn_loc.expand(fn_filepath, line, column);
    if (sn_loc)
      sn_loc.expand(sn_filepath, line, column);
    return fn_filepath < sn_filepath;
  }

  /// The less than operator.  First, it sorts the methods by their
  /// vtable index.  If they have the same vtable index, it sorts them
  /// by the name of their ELF symbol.  If they don't have elf
  /// symbols, it sorts them by considering their pretty
  /// representation.
  ///
  ///  Note that this method expects to take virtual methods.
  ///
  /// @param f the first method to consider.
  ///
  /// @param s the second method to consider.
  bool
  operator()(const method_decl_sptr f,
         const method_decl_sptr s)
  {return operator()(*f, *s);}
}; // end struct virtual_member_function_less_than

/// Sort a vector of instances of virtual member functions.
///
/// @param mem_fns the vector of member functions to sort.
static void
sort_virtual_member_functions(class_decl::member_functions& mem_fns)
{
  virtual_member_function_less_than lt;
  std::stable_sort(mem_fns.begin(), mem_fns.end(), lt);
}

/// Add a member function to the current instance of @ref class_or_union.
///
/// @param f a method_decl to add to the current class.  This function
/// should not have been already added to a scope.
///
/// @param access the access specifier for the member function to add.
///
/// @param is_virtual if this is true then it means the function @p f
/// is a virtual function.  That also means that the current instance
/// of @ref class_or_union is actually an instance of @ref class_decl.
///
/// @param vtable_offset the offset of the member function in the
/// virtual table.  This parameter is taken into account only if @p
/// is_virtual is true.
///
/// @param is_static whether the member function is static.
///
/// @param is_ctor whether the member function is a constructor.
///
/// @param is_dtor whether the member function is a destructor.
///
/// @param is_const whether the member function is const.
void
class_or_union::add_member_function(method_decl_sptr f,
                    access_specifier a,
                    bool is_virtual,
                    size_t vtable_offset,
                    bool is_static, bool is_ctor,
                    bool is_dtor, bool is_const)
{
  add_member_function(f, a, is_static, is_ctor,
              is_dtor, is_const);

  if (class_decl* klass = is_class_type(this))
    {
      if (is_virtual)
    {
      set_member_function_virtuality(f, is_virtual, vtable_offset);
      sort_virtual_member_functions(klass->priv_->virtual_mem_fns_);
    }
    }
}

/// When a virtual member function has seen its virtualness set by
/// set_member_function_is_virtual(), this function ensures that the
/// member function is added to the specific vectors and maps of
/// virtual member function of its class.
///
/// @param method the method to fixup.
void
fixup_virtual_member_function(method_decl_sptr method)
{
  if (!method || !get_member_function_is_virtual(method))
    return;

  class_decl_sptr klass = is_class_type(method->get_type()->get_class_type());

  class_decl::member_functions::const_iterator m;
  for (m = klass->priv_->virtual_mem_fns_.begin();
       m != klass->priv_->virtual_mem_fns_.end();
       ++m)
    if (m->get() == method.get()
    || (*m)->get_linkage_name() == method->get_linkage_name())
      break;
  if (m == klass->priv_->virtual_mem_fns_.end())
    klass->priv_->virtual_mem_fns_.push_back(method);

  // Build or udpate the map that associates a vtable offset to the
  // number of virtual member functions that "point" to it.
  ssize_t voffset = get_member_function_vtable_offset(method);
  if (voffset == -1)
    return;

  class_decl::virtual_mem_fn_map_type::iterator i =
    klass->priv_->virtual_mem_fns_map_.find(voffset);
  if (i == klass->priv_->virtual_mem_fns_map_.end())
    {
      class_decl::member_functions virtual_mem_fns_at_voffset;
      virtual_mem_fns_at_voffset.push_back(method);
      klass->priv_->virtual_mem_fns_map_[voffset] = virtual_mem_fns_at_voffset;
    }
  else
    {
      for (m = i->second.begin() ; m != i->second.end(); ++m)
    if (m->get() == method.get()
        || (*m)->get_linkage_name() == method->get_linkage_name())
      break;
      if (m == i->second.end())
    i->second.push_back(method);
    }
}

/// Return true iff the class has no entity in its scope.
bool
class_decl::has_no_base_nor_member() const
{return priv_->bases_.empty() && has_no_member();}

/// Test if the current instance of @ref class_decl has virtual member
/// functions.
///
/// @return true iff the current instance of @ref class_decl has
/// virtual member functions.
bool
class_decl::has_virtual_member_functions() const
{return !get_virtual_mem_fns().empty();}

/// Test if the current instance of @ref class_decl has at least one
/// virtual base.
///
/// @return true iff the current instance of @ref class_decl has a
/// virtual member function.
bool
class_decl::has_virtual_bases() const
{
  for (base_specs::const_iterator b = get_base_specifiers().begin();
       b != get_base_specifiers().end();
       ++b)
    if ((*b)->get_is_virtual()
    || (*b)->get_base_class()->has_virtual_bases())
      return true;

  return false;
}

/// Test if the current instance has a vtable.
///
/// This is only valid for a C++ program.
///
/// Basically this function checks if the class has either virtual
/// functions, or virtual bases.
bool
class_decl::has_vtable() const
{
  if (has_virtual_member_functions()
      || has_virtual_bases())
    return true;
  return false;
}

/// Get the highest vtable offset of all the virtual methods of the
/// class.
///
/// @return the highest vtable offset of all the virtual methods of
/// the class.
ssize_t
class_decl::get_biggest_vtable_offset() const
{
  ssize_t offset = -1;
  for (class_decl::virtual_mem_fn_map_type::const_iterator e =
     get_virtual_mem_fns_map().begin();
       e != get_virtual_mem_fns_map().end();
       ++e)
    if (e->first > offset)
      offset = e->first;

  return offset;
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
class_decl::hash_value() const
{
  hash_t h = set_or_get_cached_hash_value(this);
  return h;
}

/// Test if two methods are equal without taking their symbol or
/// linkage name into account.
///
/// @param f the first method.
///
/// @param s the second method.
///
/// @return true iff @p f equals @p s without taking their linkage
/// name or symbol into account.
static bool
methods_equal_modulo_elf_symbol(const method_decl_sptr& f,
                const method_decl_sptr& s)
{
  method_decl_sptr first = f, second = s;
  elf_symbol_sptr saved_first_elf_symbol =
    first->get_symbol();
  elf_symbol_sptr saved_second_elf_symbol =
    second->get_symbol();
  interned_string saved_first_linkage_name =
    first->get_linkage_name();
  interned_string saved_second_linkage_name =
    second->get_linkage_name();

  first->set_symbol(elf_symbol_sptr());
  first->set_linkage_name("");
  second->set_symbol(elf_symbol_sptr());
  second->set_linkage_name("");

  bool equal = *first == *second;

  first->set_symbol(saved_first_elf_symbol);
  first->set_linkage_name(saved_first_linkage_name);
  second->set_symbol(saved_second_elf_symbol);
  second->set_linkage_name(saved_second_linkage_name);

  return equal;
}

/// Test if a given method is equivalent to at least of other method
/// that is in a vector of methods.
///
/// Note that "equivalent" here means being equal without taking the
/// linkage name or the symbol of the methods into account.
///
/// This is a sub-routine of the 'equals' function that compares @ref
/// class_decl.
///
/// @param method the method to compare.
///
/// @param fns the vector of functions to compare @p method against.
///
/// @return true iff @p is equivalent to at least one method in @p
/// fns.
static bool
method_matches_at_least_one_in_vector(const method_decl_sptr& method,
                      const class_decl::member_functions& fns)
{
  for (class_decl::member_functions::const_iterator i = fns.begin();
       i != fns.end();
       ++i)
    // Note that the comparison must be done in this order: method ==
    //  *i This is to keep the consistency of the comparison.  It's
    //  important especially when doing type canonicalization.  The
    //  already canonicalize type is the left operand, and the type
    //  being canonicalized is the right operand.  This comes from the
    // code in type_base::get_canonical_type_for().
    if (methods_equal_modulo_elf_symbol(method, *i))
      return true;

  return false;
}

/// Compares two instances of @ref class_decl.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const class_decl& l, const class_decl& r, change_kind* k)
{
  {
    // First of all, let's see if these two types haven't already been
    // compared.  If so, and if the result of the comparison has been
    // cached, let's just re-use it, rather than comparing them all
    // over again.
    bool result = false;
    if (l.get_environment().priv_->is_type_comparison_cached(l, r, result))
      ABG_RETURN(result);
  }

  // if one of the classes is declaration-only then we take a fast
  // path here.
  if (l.get_is_declaration_only() || r.get_is_declaration_only())
    ABG_RETURN(equals(static_cast<const class_or_union&>(l),
              static_cast<const class_or_union&>(r),
              k));

  bool result = true;
  if (!equals(static_cast<const class_or_union&>(l),
          static_cast<const class_or_union&>(r),
          k))
    {
      result = false;
      if (!k)
    ABG_RETURN(result);
    }

  RETURN_TRUE_IF_COMPARISON_CYCLE_DETECTED(l, r);

  mark_types_as_being_compared(l, r);

#define RETURN(value) CACHE_AND_RETURN_COMPARISON_RESULT(value)

  // Compare bases.
  if (l.get_base_specifiers().size() != r.get_base_specifiers().size())
    {
      result = false;
      if (k)
    *k |= LOCAL_TYPE_CHANGE_KIND;
      else
    RETURN(result);
    }

  for (class_decl::base_specs::const_iterator
     b0 = l.get_base_specifiers().begin(),
     b1 = r.get_base_specifiers().begin();
       (b0 != l.get_base_specifiers().end()
    && b1 != r.get_base_specifiers().end());
       ++b0, ++b1)
    if (*b0 != *b1)
      {
    result = false;
    if (k)
      {
        if (!types_have_similar_structure((*b0)->get_base_class().get(),
                          (*b1)->get_base_class().get()))
          *k |= LOCAL_TYPE_CHANGE_KIND;
        else
          *k |= SUBTYPE_CHANGE_KIND;
        break;
      }
    RETURN(result);
      }

  // Compare virtual member functions

  // We look at the map that associates a given vtable offset to a
  // vector of virtual member functions that point to that offset.
  //
  // This is because there are cases where several functions can
  // point to the same virtual table offset.
  //
  // This is usually the case for virtual destructors.  Even though
  // there can be only one virtual destructor declared in source
  // code, there are actually potentially up to three generated
  // functions for that destructor.  Some of these generated
  // functions can be clones of other functions that are among those
  // generated ones.  In any cases, they all have the same
  // properties, including the vtable offset property.

  // So, there should be the same number of different vtable
  // offsets, the size of two maps must be equals.
  if (l.get_virtual_mem_fns_map().size()
      != r.get_virtual_mem_fns_map().size())
    {
      result = false;
      if (k)
    *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      else
    RETURN(result);
    }

  // Then, each virtual member function of a given vtable offset in
  // the first class type, must match an equivalent virtual member
  // function of a the same vtable offset in the second class type.
  //
  // By "match", I mean that the two virtual member function should
  // be equal if we don't take into account their symbol name or
  // their linkage name.  This is because two destructor functions
  // clones (for instance) might have different linkage name, but
  // are still equivalent if their other properties are the same.
  for (class_decl::virtual_mem_fn_map_type::const_iterator first_v_fn_entry =
     l.get_virtual_mem_fns_map().begin();
       first_v_fn_entry != l.get_virtual_mem_fns_map().end();
       ++first_v_fn_entry)
    {
      unsigned voffset = first_v_fn_entry->first;
      const class_decl::member_functions& first_vfns =
    first_v_fn_entry->second;

      const class_decl::virtual_mem_fn_map_type::const_iterator
    second_v_fn_entry = r.get_virtual_mem_fns_map().find(voffset);

      if (second_v_fn_entry == r.get_virtual_mem_fns_map().end())
    {
      result = false;
      if (k)
        *k |= LOCAL_NON_TYPE_CHANGE_KIND;
      RETURN(result);
    }

      const class_decl::member_functions& second_vfns =
    second_v_fn_entry->second;

      bool matches = false;
      for (class_decl::member_functions::const_iterator i =
         first_vfns.begin();
       i != first_vfns.end();
       ++i)
    if (method_matches_at_least_one_in_vector(*i, second_vfns))
      {
        matches = true;
        break;
      }

      if (!matches)
    {
      result = false;
      if (k)
        *k |= SUBTYPE_CHANGE_KIND;
      else
        RETURN(result);
    }
    }

  RETURN(result);
#undef RETURN
}

/// Copy a method of a class into a new class.
///
/// @param klass the class into which the method is to be copied.
///
/// @param method the method to copy into @p klass.
///
/// @return the resulting newly copied method.
method_decl_sptr
copy_member_function(class_decl_sptr clazz, const method_decl_sptr& f)
{return copy_member_function(static_pointer_cast<class_or_union>(clazz), f);}

/// Copy a method of a class into a new class.
///
/// @param klass the class into which the method is to be copied.
///
/// @param method the method to copy into @p klass.
///
/// @return the resulting newly copied method.
method_decl_sptr
copy_member_function(class_decl_sptr clazz, const method_decl* f)
{return copy_member_function(static_pointer_cast<class_or_union>(clazz), f);}

/// Comparison operator for @ref class_decl.
///
/// @param other the instance of @ref class_decl to compare against.
///
/// @return true iff the current instance of @ref class_decl equals @p
/// other.
bool
class_decl::operator==(const decl_base& other) const
{
  const class_decl* op = is_class_type(&other);
  if (!op)
    {
      if (class_or_union* cou = is_class_or_union_type(&other))
    return class_or_union::operator==(*cou);
      return false;
    }

  // If this is a decl-only type (and thus with no canonical type),
  // use the canonical type of the definition, if any.
  const class_decl *l = 0;
  if (get_is_declaration_only())
    l = dynamic_cast<const class_decl*>(get_naked_definition_of_declaration());
  if (l == 0)
    l = this;

  ABG_ASSERT(l);

  // Likewise for the other type.
  const class_decl *r = 0;
  if (op->get_is_declaration_only())
    r = dynamic_cast<const class_decl*>(op->get_naked_definition_of_declaration());
  if (r == 0)
    r = op;

  ABG_ASSERT(r);

  return try_canonical_compare(l, r);
}

/// Equality operator for class_decl.
///
/// Re-uses the equality operator that takes a decl_base.
///
/// @param other the other class_decl to compare against.
///
/// @return true iff the current instance equals the other one.
bool
class_decl::operator==(const type_base& other) const
{
  const decl_base* o = is_decl(&other);
  if (!o)
    return false;
  return *this == *o;
}

/// Equality operator for class_decl.
///
/// Re-uses the equality operator that takes a decl_base.
///
/// @param other the other class_decl to compare against.
///
/// @return true iff the current instance equals the other one.
bool
class_decl::operator==(const class_or_union& other) const
{
  const decl_base& o = other;
  return *this == o;
}

/// Comparison operator for @ref class_decl.
///
/// @param other the instance of @ref class_decl to compare against.
///
/// @return true iff the current instance of @ref class_decl equals @p
/// other.
bool
class_decl::operator==(const class_decl& other) const
{
  const decl_base& o = other;
  return *this == o;
}

/// Turn equality of shared_ptr of class_decl into a deep equality;
/// that is, make it compare the pointed to objects too.
///
/// @param l the shared_ptr of class_decl on left-hand-side of the
/// equality.
///
/// @param r the shared_ptr of class_decl on right-hand-side of the
/// equality.
///
/// @return true if the class_decl pointed to by the shared_ptrs are
/// equal, false otherwise.
bool
operator==(const class_decl_sptr& l, const class_decl_sptr& r)
{
  if (l.get() == r.get())
    return true;
  if (!!l != !!r)
    return false;

  return *l == *r;
}

/// Turn inequality of shared_ptr of class_decl into a deep equality;
/// that is, make it compare the pointed to objects too.
///
/// @param l the shared_ptr of class_decl on left-hand-side of the
/// equality.
///
/// @param r the shared_ptr of class_decl on right-hand-side of the
/// equality.
///
/// @return true if the class_decl pointed to by the shared_ptrs are
/// different, false otherwise.
bool
operator!=(const class_decl_sptr& l, const class_decl_sptr& r)
{return !operator==(l, r);}

/// Turn equality of shared_ptr of class_or_union into a deep
/// equality; that is, make it compare the pointed to objects too.
///
/// @param l the left-hand-side operand of the operator
///
/// @param r the right-hand-side operand of the operator.
///
/// @return true iff @p l equals @p r.
bool
operator==(const class_or_union_sptr& l, const class_or_union_sptr& r)
{
  if (l.get() == r.get())
    return true;
  if (!!l != !!r)
    return false;

  return *l == *r;
}

/// Turn inequality of shared_ptr of class_or_union into a deep
/// equality; that is, make it compare the pointed to objects too.
///
/// @param l the left-hand-side operand of the operator
///
/// @param r the right-hand-side operand of the operator.
///
/// @return true iff @p l is different from @p r.
bool
operator!=(const class_or_union_sptr& l, const class_or_union_sptr& r)
{return !operator==(l, r);}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance and on its
/// members.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
class_decl::traverse(ir_node_visitor& v)
{
  if (v.type_node_has_been_visited(this))
    return true;

  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      bool stop = false;

      for (base_specs::const_iterator i = get_base_specifiers().begin();
       i != get_base_specifiers().end();
       ++i)
    {
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }
    }

      if (!stop)
    for (data_members::const_iterator i = get_data_members().begin();
         i != get_data_members().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }

      if (!stop)
    for (member_functions::const_iterator i= get_member_functions().begin();
         i != get_member_functions().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }

      if (!stop)
    for (member_types::const_iterator i = get_member_types().begin();
         i != get_member_types().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }

      if (!stop)
    for (member_function_templates::const_iterator i =
           get_member_function_templates().begin();
         i != get_member_function_templates().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }

      if (!stop)
    for (member_class_templates::const_iterator i =
           get_member_class_templates().begin();
         i != get_member_class_templates().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }
      visiting(false);
    }

  bool result = v.visit_end(this);
  v.mark_type_node_as_visited(this);
  return result;
}

/// Destructor of the @ref class_decl type.
class_decl::~class_decl()
{delete priv_;}

context_rel::~context_rel()
{}

bool
member_base::operator==(const member_base& o) const
{
  return (get_access_specifier() == o.get_access_specifier()
      && get_is_static() == o.get_is_static());
}

/// Equality operator for smart pointers to @ref
/// class_decl::base_specs.
///
/// This compares the pointed-to objects.
///
/// @param l the first instance to consider.
///
/// @param r the second instance to consider.
///
/// @return true iff @p l equals @p r.
bool
operator==(const class_decl::base_spec_sptr& l,
       const class_decl::base_spec_sptr& r)
{
  if (l.get() == r.get())
    return true;
  if (!!l != !!r)
    return false;

  return *l == static_cast<const decl_base&>(*r);
}

/// Inequality operator for smart pointers to @ref
/// class_decl::base_specs.
///
/// This compares the pointed-to objects.
///
/// @param l the first instance to consider.
///
/// @param r the second instance to consider.
///
/// @return true iff @p l is different from @p r.
bool
operator!=(const class_decl::base_spec_sptr& l,
       const class_decl::base_spec_sptr& r)
{return !operator==(l, r);}

/// Test if an ABI artifact is a class base specifier.
///
/// @param tod the ABI artifact to consider.
///
/// @return a pointer to the @ref class_decl::base_spec sub-object of
/// @p tod iff it's a class base specifier.
class_decl::base_spec*
is_class_base_spec(const type_or_decl_base* tod)
{
  return dynamic_cast<class_decl::base_spec*>
    (const_cast<type_or_decl_base*>(tod));
}

/// Test if an ABI artifact is a class base specifier.
///
/// @param tod the ABI artifact to consider.
///
/// @return a pointer to the @ref class_decl::base_spec sub-object of
/// @p tod iff it's a class base specifier.
class_decl::base_spec_sptr
is_class_base_spec(type_or_decl_base_sptr tod)
{return dynamic_pointer_cast<class_decl::base_spec>(tod);}

bool
member_function_template::operator==(const member_base& other) const
{
  try
    {
      const member_function_template& o =
    dynamic_cast<const member_function_template&>(other);

      if (!(is_constructor() == o.is_constructor()
        && is_const() == o.is_const()
        && member_base::operator==(o)))
    return false;

      if (function_tdecl_sptr ftdecl = as_function_tdecl())
    {
      function_tdecl_sptr other_ftdecl = o.as_function_tdecl();
      if (other_ftdecl)
        return ftdecl->function_tdecl::operator==(*other_ftdecl);
    }
    }
  catch(...)
    {}
  return false;
}

/// Equality operator for smart pointers to @ref
/// member_function_template.  This is compares the
/// pointed-to instances.
///
/// @param l the first instance to consider.
///
/// @param r the second instance to consider.
///
/// @return true iff @p l equals @p r.
bool
operator==(const member_function_template_sptr& l,
       const member_function_template_sptr& r)
{
  if (l.get() == r.get())
    return true;
  if (!!l != !!r)
    return false;

  return *l == *r;
}

/// Inequality operator for smart pointers to @ref
/// member_function_template.  This is compares the pointed-to
/// instances.
///
/// @param l the first instance to consider.
///
/// @param r the second instance to consider.
///
/// @return true iff @p l equals @p r.
bool
operator!=(const member_function_template_sptr& l,
       const member_function_template_sptr& r)
{return !operator==(l, r);}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance and on its
/// underlying function template.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
member_function_template::traverse(ir_node_visitor& v)
{
  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      if (function_tdecl_sptr f = as_function_tdecl())
    f->traverse(v);
      visiting(false);
    }
  return v.visit_end(this);
}

/// Equality operator of the the @ref member_class_template class.
///
/// @param other the other @ref member_class_template to compare against.
///
/// @return true iff the current instance equals @p other.
bool
member_class_template::operator==(const member_base& other) const
{
  try
    {
      const member_class_template& o =
    dynamic_cast<const member_class_template&>(other);

      if (!member_base::operator==(o))
    return false;

      return as_class_tdecl()->class_tdecl::operator==(o);
    }
  catch(...)
    {return false;}
}

/// Equality operator of the the @ref member_class_template class.
///
/// @param other the other @ref member_class_template to compare against.
///
/// @return true iff the current instance equals @p other.
bool
member_class_template::operator==(const decl_base& other) const
{
  if (!decl_base::operator==(other))
    return false;
  return as_class_tdecl()->class_tdecl::operator==(other);
}

/// Comparison operator for the @ref member_class_template
/// type.
///
/// @param other the other instance of @ref
/// member_class_template to compare against.
///
/// @return true iff the two instances are equal.
bool
member_class_template::operator==(const member_class_template& other) const
{
  const decl_base* o = dynamic_cast<const decl_base*>(&other);
  return *this == *o;
}

/// Comparison operator for the @ref member_class_template
/// type.
///
/// @param l the first argument of the operator.
///
/// @param r the second argument of the operator.
///
/// @return true iff the two instances are equal.
bool
operator==(const member_class_template_sptr& l,
       const member_class_template_sptr& r)
{
  if (l.get() == r.get())
    return true;
  if (!!l != !!r)
    return false;

  return *l == *r;
}

/// Inequality operator for the @ref member_class_template
/// type.
///
/// @param l the first argument of the operator.
///
/// @param r the second argument of the operator.
///
/// @return true iff the two instances are equal.
bool
operator!=(const member_class_template_sptr& l,
       const member_class_template_sptr& r)
{return !operator==(l, r);}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance and on the class
/// pattern of the template.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
member_class_template::traverse(ir_node_visitor& v)
{
  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      if (class_tdecl_sptr t = as_class_tdecl())
    t->traverse(v);
      visiting(false);
    }
  return v.visit_end(this);
}

/// Streaming operator for class_decl::access_specifier.
///
/// @param o the output stream to serialize the access specifier to.
///
/// @param a the access specifier to serialize.
///
/// @return the output stream.
std::ostream&
operator<<(std::ostream& o, access_specifier a)
{
  string r;

  switch (a)
  {
  case no_access:
    r = "none";
    break;
  case private_access:
    r = "private";
    break;
  case protected_access:
    r = "protected";
    break;
  case public_access:
    r= "public";
    break;
  };
  o << r;
  return o;
}

/// Sets the static-ness property of a class member.
///
/// @param d the class member to set the static-ness property for.
/// Note that this must be a class member otherwise the function
/// aborts the current process.
///
/// @param s this must be true if the member is to be static, false
/// otherwise.
void
set_member_is_static(decl_base& d, bool s)
{
  ABG_ASSERT(is_member_decl(d));

  context_rel* c = d.get_context_rel();
  ABG_ASSERT(c);

  c->set_is_static(s);

  scope_decl* scope = d.get_scope();

  if (class_or_union* cl = is_class_or_union_type(scope))
    {
      if (var_decl* v = is_var_decl(&d))
    {
      // First, find v in the set of data members.
      var_decl_sptr var;
      for (const auto& dm : cl->get_data_members())
        if (dm->get_name() == v->get_name())
          {
        var = dm;
        break;
          }
      if (!var)
        return;

      if (s)
        {
          // remove from the non-static data members
          for (class_decl::data_members::iterator i =
             cl->priv_->non_static_data_members_.begin();
           i != cl->priv_->non_static_data_members_.end();
           ++i)
        {
          if ((*i)->get_name() == v->get_name())
            {
              cl->priv_->non_static_data_members_.erase(i);
              break;
            }
        }

          // If it's not in the static data members, then add it
          // there.
          bool already_in_static_dms = false;
          for (const auto& s_dm : cl->priv_->static_data_members_)
        if (s_dm->get_name() == v->get_name())
          {
            already_in_static_dms = true;
            break;
          }
          if (!already_in_static_dms)
        cl->priv_->static_data_members_.push_back(var);
        }
      else // is non-static
        {
          // Remove from the static data members.
          for (class_or_union::data_members::iterator i =
             cl->priv_->static_data_members_.begin();
           i != cl->priv_->static_data_members_.end();
           ++i)
        if ((*i)->get_name() == v->get_name())
          {
            cl->priv_->static_data_members_.erase(i);
            break;
          }

          // If it's not already in the non-static data members
          // then add it there.
          bool is_already_in_non_static_data_members = false;
          for (const auto& ns_dm : cl->priv_->non_static_data_members_)
        if (ns_dm->get_name() == v->get_name())
          {
            is_already_in_non_static_data_members = true;
            break;
          }
          if (!is_already_in_non_static_data_members)
        cl->priv_->non_static_data_members_.push_back(var);
        }
    }
    }
}

/// Sets the static-ness property of a class member.
///
/// @param d the class member to set the static-ness property for.
/// Note that this must be a class member otherwise the function
/// aborts the current process.
///
/// @param s this must be true if the member is to be static, false
/// otherwise.
void
set_member_is_static(const decl_base_sptr& d, bool s)
{set_member_is_static(*d, s);}

// </class_decl>

// <union_decl>

/// Constructor for the @ref union_decl type.
///
/// @param env the @ref environment we are operating from.
///
/// @param name the name of the union type.
///
/// @param size_in_bits the size of the union, in bits.
///
/// @param locus the location of the type.
///
/// @param vis the visibility of instances of @ref union_decl.
///
/// @param mbr_types the member types of the union.
///
/// @param data_mbrs the data members of the union.
///
/// @param member_fns the member functions of the union.
union_decl::union_decl(const environment& env, const string& name,
               size_t size_in_bits, const location& locus,
               visibility vis, member_types& mbr_types,
               data_members& data_mbrs, member_functions& member_fns)
  : type_or_decl_base(env,
              UNION_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    decl_base(env, name, locus, name, vis),
    type_base(env, size_in_bits, 0),
    class_or_union(env, name, size_in_bits, 0,
           locus, vis, mbr_types, data_mbrs, member_fns)
{
  runtime_type_instance(this);
}

/// Constructor for the @ref union_decl type.
///
/// @param env the @ref environment we are operating from.
///
/// @param name the name of the union type.
///
/// @param size_in_bits the size of the union, in bits.
///
/// @param locus the location of the type.
///
/// @param vis the visibility of instances of @ref union_decl.
///
/// @param mbr_types the member types of the union.
///
/// @param data_mbrs the data members of the union.
///
/// @param member_fns the member functions of the union.
///
/// @param is_anonymous whether the newly created instance is
/// anonymous.
union_decl::union_decl(const environment& env, const string& name,
               size_t size_in_bits, const location& locus,
               visibility vis, member_types& mbr_types,
               data_members& data_mbrs, member_functions& member_fns,
               bool is_anonymous)
  : type_or_decl_base(env,
              UNION_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE),
    decl_base(env, name, locus,
          // If the class is anonymous then by default it won't
          // have a linkage name.  Also, the anonymous class does
          // have an internal-only unique name that is generally
          // not taken into account when comparing classes; such a
          // unique internal-only name, when used as a linkage
          // name might introduce spurious comparison false
          // negatives.
          /*linkage_name=*/is_anonymous ? string() : name,
          vis),
    type_base(env, size_in_bits, 0),
    class_or_union(env, name, size_in_bits, 0,
           locus, vis, mbr_types, data_mbrs, member_fns)
{
  runtime_type_instance(this);
  set_is_anonymous(is_anonymous);
}

/// Constructor for the @ref union_decl type.
///
/// @param env the @ref environment we are operating from.
///
/// @param name the name of the union type.
///
/// @param size_in_bits the size of the union, in bits.
///
/// @param locus the location of the type.
///
/// @param vis the visibility of instances of @ref union_decl.
union_decl::union_decl(const environment& env, const string& name,
               size_t size_in_bits, const location& locus,
               visibility vis)
  : type_or_decl_base(env,
              UNION_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE
              | ABSTRACT_SCOPE_TYPE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(env, name, locus, name, vis),
    type_base(env, size_in_bits, 0),
    class_or_union(env, name, size_in_bits,
           0, locus, vis)
{
  runtime_type_instance(this);
}

/// Constructor for the @ref union_decl type.
///
/// @param env the @ref environment we are operating from.
///
/// @param name the name of the union type.
///
/// @param size_in_bits the size of the union, in bits.
///
/// @param locus the location of the type.
///
/// @param vis the visibility of instances of @ref union_decl.
///
/// @param is_anonymous whether the newly created instance is
/// anonymous.
union_decl::union_decl(const environment& env, const string& name,
               size_t size_in_bits, const location& locus,
               visibility vis, bool is_anonymous)
  : type_or_decl_base(env,
              UNION_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE
              | ABSTRACT_SCOPE_TYPE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(env, name, locus,
          // If the class is anonymous then by default it won't
          // have a linkage name.  Also, the anonymous class does
          // have an internal-only unique name that is generally
          // not taken into account when comparing classes; such a
          // unique internal-only name, when used as a linkage
          // name might introduce spurious comparison false
          // negatives.
          /*linkage_name=*/is_anonymous ? string() : name,
          vis),
    type_base(env, size_in_bits, 0),
    class_or_union(env, name, size_in_bits,
           0, locus, vis)
{
  runtime_type_instance(this);
  set_is_anonymous(is_anonymous);
}

/// Constructor for the @ref union_decl type.
///
/// @param env the @ref environment we are operating from.
///
/// @param name the name of the union type.
///
/// @param is_declaration_only a boolean saying whether the instance
/// represents a declaration only, or not.
union_decl::union_decl(const environment& env,
               const string& name,
               bool is_declaration_only)
  : type_or_decl_base(env,
              UNION_TYPE
              | ABSTRACT_TYPE_BASE
              | ABSTRACT_DECL_BASE
              | ABSTRACT_SCOPE_TYPE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(env, name, location(), name),
    type_base(env, 0, 0),
    class_or_union(env, name, is_declaration_only)
{
  runtime_type_instance(this);
}

/// Return the hash value of the current IR node.
///
/// Note that upon the first invocation, this member functions
/// computes the hash value and returns it.  Subsequent invocations
/// just return the hash value that was previously calculated.
///
/// @return the hash value of the current IR node.
hash_t
union_decl::hash_value() const
{
  hash_t h = set_or_get_cached_hash_value(this);
  return h;
}

/// Getter of the pretty representation of the current instance of
/// @ref union_decl.
///
/// @param internal set to true if the call is intended to get a
/// representation of the decl (or type) for the purpose of canonical
/// type comparison.  This is mainly used in the function
/// type_base::get_canonical_type_for().
///
/// In other words if the argument for this parameter is true then the
/// call is meant for internal use (for technical use inside the
/// library itself), false otherwise.  If you don't know what this is
/// for, then set it to false.
///
/// @param qualified_name if true, names emitted in the pretty
/// representation are fully qualified.
///
/// @return the pretty representaion for a union_decl.
string
union_decl::get_pretty_representation(bool internal,
                      bool qualified_name) const
{
  string repr;
  if (get_is_anonymous())
    {
      if (internal && !get_name().empty())
    repr = string("union ") +
      get_type_name(this, qualified_name, /*internal=*/true);
      else
    repr = get_class_or_union_flat_representation(this, "",
                              /*one_line=*/true,
                              internal);
    }
  else
    {
      repr = "union ";
      if (qualified_name)
    repr += get_qualified_name(internal);
      else
    repr += get_name();
    }

  return repr;
}

/// Comparison operator for @ref union_decl.
///
/// @param other the instance of @ref union_decl to compare against.
///
/// @return true iff the current instance of @ref union_decl equals @p
/// other.
bool
union_decl::operator==(const decl_base& other) const
{
  const union_decl* op = dynamic_cast<const union_decl*>(&other);
  if (!op)
    return false;
  return try_canonical_compare(this, op);
}

/// Equality operator for union_decl.
///
/// Re-uses the equality operator that takes a decl_base.
///
/// @param other the other union_decl to compare against.
///
/// @return true iff the current instance equals the other one.
bool
union_decl::operator==(const type_base& other) const
{
  const decl_base *o = dynamic_cast<const decl_base*>(&other);
  if (!o)
    return false;
  return *this == *o;
}

/// Equality operator for union_decl.
///
/// Re-uses the equality operator that takes a decl_base.
///
/// @param other the other union_decl to compare against.
///
/// @return true iff the current instance equals the other one.
bool
union_decl::operator==(const class_or_union&other) const
{
  const decl_base *o = dynamic_cast<const decl_base*>(&other);
  return *this == *o;
}

/// Comparison operator for @ref union_decl.
///
/// @param other the instance of @ref union_decl to compare against.
///
/// @return true iff the current instance of @ref union_decl equals @p
/// other.
bool
union_decl::operator==(const union_decl& other) const
{
  const decl_base& o = other;
  return *this == o;
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance and on its
/// members.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
union_decl::traverse(ir_node_visitor& v)
{
  if (v.type_node_has_been_visited(this))
    return true;

  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      bool stop = false;

      if (!stop)
    for (data_members::const_iterator i = get_data_members().begin();
         i != get_data_members().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }

      if (!stop)
    for (member_functions::const_iterator i= get_member_functions().begin();
         i != get_member_functions().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }

      if (!stop)
    for (member_types::const_iterator i = get_member_types().begin();
         i != get_member_types().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }

      if (!stop)
    for (member_function_templates::const_iterator i =
           get_member_function_templates().begin();
         i != get_member_function_templates().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }

      if (!stop)
    for (member_class_templates::const_iterator i =
           get_member_class_templates().begin();
         i != get_member_class_templates().end();
         ++i)
      if (!(*i)->traverse(v))
        {
          stop = true;
          break;
        }
      visiting(false);
    }

  bool result = v.visit_end(this);
  v.mark_type_node_as_visited(this);
  return result;
}

/// Destructor of the @ref union_decl type.
union_decl::~union_decl()
{}

/// Compares two instances of @ref union_decl.
///
/// If the two intances are different, set a bitfield to give some
/// insight about the kind of differences there are.
///
/// @param l the first artifact of the comparison.
///
/// @param r the second artifact of the comparison.
///
/// @param k a pointer to a bitfield that gives information about the
/// kind of changes there are between @p l and @p r.  This one is set
/// iff @p k is non-null and the function returns false.
///
/// Please note that setting k to a non-null value does have a
/// negative performance impact because even if @p l and @p r are not
/// equal, the function keeps up the comparison in order to determine
/// the different kinds of ways in which they are different.
///
/// @return true if @p l equals @p r, false otherwise.
bool
equals(const union_decl& l, const union_decl& r, change_kind* k)
{

  RETURN_TRUE_IF_COMPARISON_CYCLE_DETECTED(l, r);

  {
    // First of all, let's see if these two types haven't already been
    // compared.  If so, and if the result of the comparison has been
    // cached, let's just re-use it, rather than comparing them all
    // over again.
    bool result = false;
    if (l.get_environment().priv_->is_type_comparison_cached(l, r, result))
      ABG_RETURN(result);
  }

  bool result = equals(static_cast<const class_or_union&>(l),
               static_cast<const class_or_union&>(r),
               k);

  CACHE_COMPARISON_RESULT_AND_RETURN(result);
}

/// Copy a method of a @ref union_decl into a new @ref
/// union_decl.
///
/// @param t the @ref union_decl into which the method is to be copied.
///
/// @param method the method to copy into @p t.
///
/// @return the resulting newly copied method.
method_decl_sptr
copy_member_function(union_decl_sptr union_type,
             const method_decl_sptr& f)
{return copy_member_function(union_type, f.get());}

/// Copy a method of a @ref union_decl into a new @ref
/// union_decl.
///
/// @param t the @ref union_decl into which the method is to be copied.
///
/// @param method the method to copy into @p t.
///
/// @return the resulting newly copied method.
method_decl_sptr
copy_member_function(union_decl_sptr union_type,
             const method_decl* f)
{
  const class_or_union_sptr t = union_type;
  return copy_member_function(t, f);
}

/// Turn equality of shared_ptr of union_decl into a deep equality;
/// that is, make it compare the pointed to objects too.
///
/// @param l the left-hand-side operand of the operator
///
/// @param r the right-hand-side operand of the operator.
///
/// @return true iff @p l equals @p r.
bool
operator==(const union_decl_sptr& l, const union_decl_sptr& r)
{
  if (l.get() == r.get())
    return true;
  if (!!l != !!r)
    return false;

  return *l == *r;
}

/// Turn inequality of shared_ptr of union_decl into a deep equality;
/// that is, make it compare the pointed to objects too.
///
/// @param l the left-hand-side operand of the operator
///
/// @param r the right-hand-side operand of the operator.
///
/// @return true iff @p l is different from @p r.
bool
operator!=(const union_decl_sptr& l, const union_decl_sptr& r)
{return !operator==(l, r);}
// </union_decl>

// <template_decl stuff>

/// Data type of the private data of the @template_decl type.
class template_decl::priv
{
  friend class template_decl;

  std::list<template_parameter_sptr> parms_;
public:

  priv()
  {}
}; // end class template_decl::priv

/// Add a new template parameter to the current instance of @ref
/// template_decl.
///
/// @param p the new template parameter to add.
void
template_decl::add_template_parameter(const template_parameter_sptr p)
{priv_->parms_.push_back(p);}

/// Get the list of template parameters of the current instance of
/// @ref template_decl.
///
/// @return the list of template parameters.
const std::list<template_parameter_sptr>&
template_decl::get_template_parameters() const
{return priv_->parms_;}

/// Constructor.
///
/// @param env the environment we are operating from.
///
/// @param name the name of the template decl.
///
/// @param locus the source location where the template declaration is
/// defined.
///
/// @param vis the visibility of the template declaration.
template_decl::template_decl(const environment& env,
                 const string& name,
                 const location& locus,
                 visibility vis)
  : type_or_decl_base(env, TEMPLATE_DECL | ABSTRACT_DECL_BASE),
    decl_base(env, name, locus, /*mangled_name=*/"", vis),
    priv_(new priv)
{
  runtime_type_instance(this);
}

/// Destructor.
template_decl::~template_decl()
{}

/// Equality operator.
///
/// @param o the other instance to compare against.
///
/// @return true iff @p equals the current instance.
bool
template_decl::operator==(const decl_base& o) const
{
  const template_decl* other = dynamic_cast<const template_decl*>(&o);
  if (!other)
    return false;
  return *this == *other;
}

/// Equality operator.
///
/// @param o the other instance to compare against.
///
/// @return true iff @p equals the current instance.
bool
template_decl::operator==(const template_decl& o) const
{
  try
    {
      list<shared_ptr<template_parameter> >::const_iterator t0, t1;
      for (t0 = get_template_parameters().begin(),
         t1 = o.get_template_parameters().begin();
       (t0 != get_template_parameters().end()
        && t1 != o.get_template_parameters().end());
       ++t0, ++t1)
    {
      if (**t0 != **t1)
        return false;
    }

      if (t0 != get_template_parameters().end()
      || t1 != o.get_template_parameters().end())
    return false;

      return true;
    }
  catch(...)
    {return false;}
}

// </template_decl stuff>

//<template_parameter>

/// The type of the private data of the @ref template_parameter type.
class template_parameter::priv
{
  friend class template_parameter;

  unsigned index_;
  template_decl_wptr template_decl_;
  mutable bool hashing_started_;
  mutable bool comparison_started_;

  priv();

public:

  priv(unsigned index, template_decl_sptr enclosing_template_decl)
    : index_(index),
      template_decl_(enclosing_template_decl),
      hashing_started_(),
      comparison_started_()
  {}
}; // end class template_parameter::priv

template_parameter::template_parameter(unsigned  index,
                       template_decl_sptr enclosing_template)
  : priv_(new priv(index, enclosing_template))
  {}

unsigned
template_parameter::get_index() const
{return priv_->index_;}

const template_decl_sptr
template_parameter::get_enclosing_template_decl() const
{return priv_->template_decl_.lock();}


bool
template_parameter::operator==(const template_parameter& o) const
{
  if (get_index() != o.get_index())
    return false;

  if (priv_->comparison_started_)
    return true;

  bool result = false;

  // Avoid inifite loops due to the fact that comparison the enclosing
  // template decl might lead to comparing this very same template
  // parameter with another one ...
  priv_->comparison_started_ = true;

  if (!!get_enclosing_template_decl() != !!o.get_enclosing_template_decl())
    ;
  else if (get_enclosing_template_decl()
       && (*get_enclosing_template_decl()
           != *o.get_enclosing_template_decl()))
    ;
  else
    result = true;

  priv_->comparison_started_ = false;

  return result;
}

/// Inequality operator.
///
/// @param other the other instance to compare against.
///
/// @return true iff the other instance is different from the current
/// one.
bool
template_parameter::operator!=(const template_parameter& other) const
{return !operator==(other);}

/// Destructor.
template_parameter::~template_parameter()
{}

/// The type of the private data of the @ref type_tparameter type.
class type_tparameter::priv
{
  friend class type_tparameter;
}; // end class type_tparameter::priv

/// Constructor of the @ref type_tparameter type.
///
/// @param index the index the type template parameter.
///
/// @param enclosing_tdecl the enclosing template declaration.
///
/// @param name the name of the template parameter.
///
/// @param locus the location of the declaration of this type template
/// parameter.
type_tparameter::type_tparameter(unsigned       index,
                 template_decl_sptr enclosing_tdecl,
                 const string&      name,
                 const location&    locus)
  : type_or_decl_base(enclosing_tdecl->get_environment(),
              ABSTRACT_DECL_BASE
              | ABSTRACT_TYPE_BASE
              | BASIC_TYPE),
    decl_base(enclosing_tdecl->get_environment(), name, locus),
    type_base(enclosing_tdecl->get_environment(), 0, 0),
    type_decl(enclosing_tdecl->get_environment(), name, 0, 0, locus),
    template_parameter(index, enclosing_tdecl),
    priv_(new priv)
{
  runtime_type_instance(this);
}

/// Equality operator.
///
/// @param other the other template type parameter to compare against.
///
/// @return true iff @p other equals the current instance.
bool
type_tparameter::operator==(const type_base& other) const
{
  if (!type_decl::operator==(other))
    return false;

  try
    {
      const type_tparameter& o = dynamic_cast<const type_tparameter&>(other);
      return template_parameter::operator==(o);
    }
  catch (...)
    {return false;}
}

/// Equality operator.
///
/// @param other the other template type parameter to compare against.
///
/// @return true iff @p other equals the current instance.
bool
type_tparameter::operator==(const type_decl& other) const
{
  if (!type_decl::operator==(other))
    return false;

  try
    {
      const type_tparameter& o = dynamic_cast<const type_tparameter&>(other);
      return template_parameter::operator==(o);
    }
  catch (...)
    {return false;}
}

/// Equality operator.
///
/// @param other the other template type parameter to compare against.
///
/// @return true iff @p other equals the current instance.
bool
type_tparameter::operator==(const decl_base& other) const
{
  if (!decl_base::operator==(other))
    return false;

  try
    {
      const type_tparameter& o = dynamic_cast<const type_tparameter&>(other);
      return template_parameter::operator==(o);
    }
  catch (...)
    {return false;}
}

/// Equality operator.
///
/// @param other the other template type parameter to compare against.
///
/// @return true iff @p other equals the current instance.
bool
type_tparameter::operator==(const template_parameter& other) const
{
  try
    {
      const type_base& o = dynamic_cast<const type_base&>(other);
      return *this == o;
    }
  catch(...)
    {return false;}
}

/// Equality operator.
///
/// @param other the other template type parameter to compare against.
///
/// @return true iff @p other equals the current instance.
bool
type_tparameter::operator==(const type_tparameter& other) const
{return *this == static_cast<const type_base&>(other);}

type_tparameter::~type_tparameter()
{}

/// The type of the private data of the @ref non_type_tparameter type.
class non_type_tparameter::priv
{
  friend class non_type_tparameter;

  type_base_wptr type_;

  priv();

public:

  priv(type_base_sptr type)
    : type_(type)
  {}
}; // end class non_type_tparameter::priv

/// The constructor for the @ref non_type_tparameter type.
///
/// @param index the index of the template parameter.
///
/// @param enclosing_tdecl the enclosing template declaration that
/// holds this parameter parameter.
///
/// @param name the name of the template parameter.
///
/// @param type the type of the template parameter.
///
/// @param locus the location of the declaration of this template
/// parameter.
non_type_tparameter::non_type_tparameter(unsigned       index,
                     template_decl_sptr enclosing_tdecl,
                     const string&      name,
                     type_base_sptr type,
                     const location&    locus)
  : type_or_decl_base(type->get_environment(), ABSTRACT_DECL_BASE),
    decl_base(type->get_environment(), name, locus, ""),
    template_parameter(index, enclosing_tdecl),
    priv_(new priv(type))
{
  runtime_type_instance(this);
}

/// Getter for the type of the template parameter.
///
/// @return the type of the template parameter.
const type_base_sptr
non_type_tparameter::get_type() const
{return priv_->type_.lock();}


bool
non_type_tparameter::operator==(const decl_base& other) const
{
  if (!decl_base::operator==(other))
    return false;

  try
    {
      const non_type_tparameter& o =
    dynamic_cast<const non_type_tparameter&>(other);
      return (template_parameter::operator==(o)
          && get_type() == o.get_type());
    }
  catch(...)
    {return false;}
}

bool
non_type_tparameter::operator==(const template_parameter& other) const
{
  try
    {
      const decl_base& o = dynamic_cast<const decl_base&>(other);
      return *this == o;
    }
  catch(...)
    {return false;}
}

non_type_tparameter::~non_type_tparameter()
{}

// <template_tparameter stuff>

/// Type of the private data of the @ref template_tparameter type.
class template_tparameter::priv
{
}; //end class template_tparameter::priv

/// Constructor for the @ref template_tparameter.
///
/// @param index the index of the template parameter.
///
/// @param enclosing_tdecl the enclosing template declaration.
///
/// @param name the name of the template parameter.
///
/// @param locus the location of the declaration of the template
/// parameter.
template_tparameter::template_tparameter(unsigned       index,
                     template_decl_sptr enclosing_tdecl,
                     const string&      name,
                     const location&    locus)
  : type_or_decl_base(enclosing_tdecl->get_environment(),
              ABSTRACT_DECL_BASE
              | ABSTRACT_TYPE_BASE
              | BASIC_TYPE),
    decl_base(enclosing_tdecl->get_environment(), name, locus),
    type_base(enclosing_tdecl->get_environment(), 0, 0),
    type_decl(enclosing_tdecl->get_environment(), name,
          0, 0, locus, name, VISIBILITY_DEFAULT),
    type_tparameter(index, enclosing_tdecl, name, locus),
    template_decl(enclosing_tdecl->get_environment(), name, locus),
    priv_(new priv)
{
  runtime_type_instance(this);
}

/// Equality operator.
///
/// @param other the other template parameter to compare against.
///
/// @return true iff @p other equals the current instance.
bool
template_tparameter::operator==(const type_base& other) const
{
  try
    {
      const template_tparameter& o =
    dynamic_cast<const template_tparameter&>(other);
      return (type_tparameter::operator==(o)
          && template_decl::operator==(o));
    }
  catch(...)
    {return false;}
}

/// Equality operator.
///
/// @param other the other template parameter to compare against.
///
/// @return true iff @p other equals the current instance.
bool
template_tparameter::operator==(const decl_base& other) const
{
  try
    {
      const template_tparameter& o =
    dynamic_cast<const template_tparameter&>(other);
      return (type_tparameter::operator==(o)
          && template_decl::operator==(o));
    }
  catch(...)
    {return false;}
}

bool
template_tparameter::operator==(const template_parameter& o) const
{
  try
    {
      const template_tparameter& other =
    dynamic_cast<const template_tparameter&>(o);
      return *this == static_cast<const type_base&>(other);
    }
  catch(...)
    {return false;}
}

bool
template_tparameter::operator==(const template_decl& o) const
{
  try
    {
      const template_tparameter& other =
    dynamic_cast<const template_tparameter&>(o);
      return type_base::operator==(other);
    }
  catch(...)
    {return false;}
}

template_tparameter::~template_tparameter()
{}

// </template_tparameter stuff>

// <type_composition stuff>

/// The type of the private data of the @ref type_composition type.
class type_composition::priv
{
  friend class type_composition;

  type_base_wptr type_;

  // Forbid this.
  priv();

public:

  priv(type_base_wptr type)
    : type_(type)
  {}
}; //end class type_composition::priv

/// Constructor for the @ref type_composition type.
///
/// @param index the index of the template type composition.
///
/// @param tdecl the enclosing template parameter that owns the
/// composition.
///
/// @param t the resulting type.
type_composition::type_composition(unsigned     index,
                   template_decl_sptr   tdecl,
                   type_base_sptr   t)
  : type_or_decl_base(tdecl->get_environment(),
              ABSTRACT_DECL_BASE),
    decl_base(tdecl->get_environment(), "", location()),
    template_parameter(index, tdecl),
    priv_(new priv(t))
{
  runtime_type_instance(this);
}

/// Getter for the resulting composed type.
///
/// @return the composed type.
const type_base_sptr
type_composition::get_composed_type() const
{return priv_->type_.lock();}

/// Setter for the resulting composed type.
///
/// @param t the composed type.
void
type_composition::set_composed_type(type_base_sptr t)
{priv_->type_ = t;}

type_composition::~type_composition()
{}

// </type_composition stuff>

//</template_parameter stuff>

// <function_template>

class function_tdecl::priv
{
  friend class function_tdecl;

  function_decl_sptr pattern_;
  binding binding_;

  priv();

public:

  priv(function_decl_sptr pattern, binding bind)
    : pattern_(pattern), binding_(bind)
  {}

  priv(binding bind)
    : binding_(bind)
  {}
}; // end class function_tdecl::priv

/// Constructor for a function template declaration.
///
/// @param env the environment we are operating from.
///
/// @param locus the location of the declaration.
///
/// @param vis the visibility of the declaration.  This is the
/// visibility the functions instantiated from this template are going
/// to have.
///
/// @param bind the binding of the declaration.  This is the binding
/// the functions instantiated from this template are going to have.
function_tdecl::function_tdecl(const environment&   env,
                   const location&      locus,
                   visibility       vis,
                   binding          bind)
  : type_or_decl_base(env,
              ABSTRACT_DECL_BASE
              | TEMPLATE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(env, "", locus, "", vis),
    template_decl(env, "", locus, vis),
    scope_decl(env, "", locus),
    priv_(new priv(bind))
{
  runtime_type_instance(this);
}

/// Constructor for a function template declaration.
///
/// @param pattern the pattern of the template.
///
/// @param locus the location of the declaration.
///
/// @param vis the visibility of the declaration.  This is the
/// visibility the functions instantiated from this template are going
/// to have.
///
/// @param bind the binding of the declaration.  This is the binding
/// the functions instantiated from this template are going to have.
function_tdecl::function_tdecl(function_decl_sptr   pattern,
                   const location&      locus,
                   visibility       vis,
                   binding          bind)
  : type_or_decl_base(pattern->get_environment(),
              ABSTRACT_DECL_BASE
              | TEMPLATE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(pattern->get_environment(), pattern->get_name(), locus,
          pattern->get_name(), vis),
    template_decl(pattern->get_environment(), pattern->get_name(), locus, vis),
    scope_decl(pattern->get_environment(), pattern->get_name(), locus),
    priv_(new priv(pattern, bind))
{
  runtime_type_instance(this);
}

/// Set a new pattern to the function template.
///
/// @param p the new pattern.
void
function_tdecl::set_pattern(function_decl_sptr p)
{
  priv_->pattern_ = p;
  add_decl_to_scope(p, this);
  set_name(p->get_name());
}

/// Get the pattern of the function template.
///
/// @return the pattern.
function_decl_sptr
function_tdecl::get_pattern() const
{return priv_->pattern_;}

/// Get the binding of the function template.
///
/// @return the binding
decl_base::binding
function_tdecl::get_binding() const
{return priv_->binding_;}

/// Comparison operator for the @ref function_tdecl type.
///
/// @param other the other instance of @ref function_tdecl to compare against.
///
/// @return true iff the two instance are equal.
bool
function_tdecl::operator==(const decl_base& other) const
{
  const function_tdecl* o = dynamic_cast<const function_tdecl*>(&other);
  if (o)
    return *this == *o;
  return false;
}

/// Comparison operator for the @ref function_tdecl type.
///
/// @param other the other instance of @ref function_tdecl to compare against.
///
/// @return true iff the two instance are equal.
bool
function_tdecl::operator==(const template_decl& other) const
{
  const function_tdecl* o = dynamic_cast<const function_tdecl*>(&other);
  if (o)
    return *this == *o;
  return false;
}

/// Comparison operator for the @ref function_tdecl type.
///
/// @param o the other instance of @ref function_tdecl to compare against.
///
/// @return true iff the two instance are equal.
bool
function_tdecl::operator==(const function_tdecl& o) const
{
  if (!(get_binding() == o.get_binding()
    && template_decl::operator==(o)
    && scope_decl::operator==(o)
    && !!get_pattern() == !!o.get_pattern()))
    return false;

  if (get_pattern())
    return (*get_pattern() == *o.get_pattern());

  return true;
}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance and on the
/// function pattern of the template.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
function_tdecl::traverse(ir_node_visitor&v)
{
  if (visiting())
    return true;

  if (!v.visit_begin(this))
    {
      visiting(true);
      if (get_pattern())
    get_pattern()->traverse(v);
      visiting(false);
    }
  return v.visit_end(this);
}

function_tdecl::~function_tdecl()
{}

// </function_template>

// <class template>

/// Type of the private data of the the @ref class_tdecl type.
class class_tdecl::priv
{
  friend class class_tdecl;
  class_decl_sptr pattern_;

public:

  priv()
  {}

  priv(class_decl_sptr pattern)
    : pattern_(pattern)
  {}
}; // end class class_tdecl::priv

/// Constructor for the @ref class_tdecl type.
///
/// @param env the environment we are operating from.
///
/// @param locus the location of the declaration of the class_tdecl
/// type.
///
/// @param vis the visibility of the instance of class instantiated
/// from this template.
class_tdecl::class_tdecl(const environment& env,
             const location&    locus,
             visibility     vis)
  : type_or_decl_base(env,
              ABSTRACT_DECL_BASE
              | TEMPLATE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(env, "", locus, "", vis),
    template_decl(env, "", locus, vis),
    scope_decl(env, "", locus),
    priv_(new priv)
{
  runtime_type_instance(this);
}

/// Constructor for the @ref class_tdecl type.
///
/// @param pattern The details of the class template. This must NOT be a
/// null pointer.  If you really this to be null, please use the
/// constructor above instead.
///
/// @param locus the source location of the declaration of the type.
///
/// @param vis the visibility of the instances of class instantiated
/// from this template.
class_tdecl::class_tdecl(class_decl_sptr    pattern,
             const location&    locus,
             visibility     vis)
  : type_or_decl_base(pattern->get_environment(),
              ABSTRACT_DECL_BASE
              | TEMPLATE_DECL
              | ABSTRACT_SCOPE_DECL),
    decl_base(pattern->get_environment(), pattern->get_name(),
          locus, pattern->get_name(), vis),
    template_decl(pattern->get_environment(), pattern->get_name(), locus, vis),
    scope_decl(pattern->get_environment(), pattern->get_name(), locus),
    priv_(new priv(pattern))
{
  runtime_type_instance(this);
}

/// Setter of the pattern of the template.
///
/// @param p the new template.
void
class_tdecl::set_pattern(class_decl_sptr p)
{
  priv_->pattern_ = p;
  add_decl_to_scope(p, this);
  set_name(p->get_name());
}

/// Getter of the pattern of the template.
///
/// @return p the new template.
class_decl_sptr
class_tdecl::get_pattern() const
{return priv_->pattern_;}

bool
class_tdecl::operator==(const decl_base& other) const
{
  try
    {
      const class_tdecl& o = dynamic_cast<const class_tdecl&>(other);

      if (!(template_decl::operator==(o)
        && scope_decl::operator==(o)
        && !!get_pattern() == !!o.get_pattern()))
    return false;

      if (!get_pattern() || !o.get_pattern())
    return true;

      return get_pattern()->decl_base::operator==(*o.get_pattern());
    }
  catch(...) {}
  return false;
}

bool
class_tdecl::operator==(const template_decl& other) const
{
  try
    {
      const class_tdecl& o = dynamic_cast<const class_tdecl&>(other);
      return *this == static_cast<const decl_base&>(o);
    }
  catch(...)
    {return false;}
}

bool
class_tdecl::operator==(const class_tdecl& o) const
{return *this == static_cast<const decl_base&>(o);}

/// This implements the ir_traversable_base::traverse pure virtual
/// function.
///
/// @param v the visitor used on the current instance and on the class
/// pattern of the template.
///
/// @return true if the entire IR node tree got traversed, false
/// otherwise.
bool
class_tdecl::traverse(ir_node_visitor&v)
{
  if (visiting())
    return true;

  if (v.visit_begin(this))
    {
      visiting(true);
      if (class_decl_sptr pattern = get_pattern())
    pattern->traverse(v);
      visiting(false);
    }
  return v.visit_end(this);
}

class_tdecl::~class_tdecl()
{}

/// This visitor checks if a given type as non-canonicalized sub
/// types.
class non_canonicalized_subtype_detector : public ir::ir_node_visitor
{
  type_base* type_;
  type_base* has_non_canonical_type_;

private:
  non_canonicalized_subtype_detector();

public:
  non_canonicalized_subtype_detector(type_base* type)
    : type_(type),
      has_non_canonical_type_()
  {}

  /// Return true if the visitor detected that there is a
  /// non-canonicalized sub-type.
  ///
  /// @return true if the visitor detected that there is a
  /// non-canonicalized sub-type.
  type_base*
  has_non_canonical_type() const
  {return has_non_canonical_type_;}

  /// The intent of this visitor handler is to avoid looking into
  /// sub-types of member functions of the type we are traversing.
  bool
  visit_begin(function_decl* f)
  {
    // Do not look at sub-types of non-virtual member functions.
    if (is_member_function(f)
    && get_member_function_is_virtual(*f))
      return false;
    return true;
  }

  /// When visiting a sub-type, if it's *NOT* been canonicalized, set
  /// the 'has_non_canonical_type' flag.  And in any case, when
  /// visiting a sub-type, do not visit its children nodes.  So this
  /// function only goes to the level below the level of the top-most
  /// type.
  ///
  /// @return true if we are at the same level as the top-most type,
  /// otherwise return false.
  bool
  visit_begin(type_base* t)
  {
    if (t != type_)
      {
    if (!t->get_canonical_type())
      // We are looking a sub-type of 'type_' which has no
      // canonical type.  So tada! we found one!  Get out right
      // now with the trophy.
      has_non_canonical_type_ = t;

    return false;
      }
    return true;
  }

  /// When we are done visiting a sub-type, if it's been flagged as
  /// been non-canonicalized, then stop the traversing.
  ///
  /// Otherwise, keep going.
  ///
  /// @return false iff the sub-type that has been visited is
  /// non-canonicalized.
  bool
  visit_end(type_base* )
  {
    if (has_non_canonical_type_)
      return false;
    return true;
  }
}; //end class non_canonicalized_subtype_detector

/// Test if a type has sub-types that are non-canonicalized.
///
/// @param t the type which sub-types to consider.
///
/// @return true if a type has sub-types that are non-canonicalized.
type_base*
type_has_non_canonicalized_subtype(type_base_sptr t)
{
  if (!t)
    return 0;

  non_canonicalized_subtype_detector v(t.get());
  t->traverse(v);
  return v.has_non_canonical_type();
}

/// Tests if the change of a given type effectively comes from just
/// its sub-types.  That is, if the type has changed but its type name
/// hasn't changed, then the change of the type mostly likely is a
/// sub-type change.
///
/// @param t_v1 the first version of the type.
///
/// @param t_v2 the second version of the type.
///
/// @return true iff the type changed and the change is about its
/// sub-types.
bool
type_has_sub_type_changes(const type_base_sptr t_v1,
              const type_base_sptr t_v2)
{
  type_base_sptr t1 = strip_typedef(t_v1);
  type_base_sptr t2 = strip_typedef(t_v2);

  string repr1 = get_pretty_representation(t1, /*internal=*/false),
    repr2 = get_pretty_representation(t2, /*internal=*/false);
  return (t1 != t2 && repr1 == repr2);
}

/// Make sure that the life time of a given (smart pointer to a) type
/// is the same as the life time of the libabigail library.
///
/// @param t the type to consider.
void
keep_type_alive(type_base_sptr t)
{
  const environment& env = t->get_environment();
  env.priv_->extra_live_types_.push_back(t);
}

/// Hash an ABI artifact that is either a type or a decl.
///
/// This function intends to provides the fastest possible hashing for
/// types and decls, while being completely correct.
///
/// Note that if the artifact is a type and if it has a canonical
/// type, the hash value is going to be the pointer value of the
/// canonical type.  Otherwise, this function computes a hash value
/// for the type by recursively walking the type members.  This last
/// code path is possibly *very* slow and should only be used when
/// only handful of types are going to be hashed.
///
/// If the artifact is a decl, then a combination of the hash of its
/// type and the hash of the other properties of the decl is computed.
///
/// @param tod the type or decl to hash.
///
/// @return the resulting hash value.
size_t
hash_type_or_decl(const type_or_decl_base *tod)
{
  hash_t result = 0;

  if (tod == 0)
    ;
  else if (const type_base* t = is_type(tod))
    result = hash_type(t);
  else if (const decl_base* d = is_decl(tod))
    {
      if (const scope_decl* s = is_scope_decl(d))
    {
      if (const global_scope* g = is_global_scope(s))
        result = reinterpret_cast<size_t>(g);
      else
        result = reinterpret_cast<size_t>(s);
    }
      else if (var_decl* v = is_var_decl(d))
    {
      ABG_ASSERT(v->get_type());
      hash_t h = hash_type_or_decl(v->get_type());
      string repr = v->get_pretty_representation(/*internal=*/true);
      std::hash<string> hash_string;
      h = hashing::combine_hashes(h, hash_string(repr));
      result = h;
    }
      else if (function_decl* f = is_function_decl(d))
    {
      ABG_ASSERT(f->get_type());
      hash_t h = hash_type_or_decl(f->get_type());
      string repr = f->get_pretty_representation(/*internal=*/true);
      std::hash<string> hash_string;
      h = hashing::combine_hashes(h, hash_string(repr));
      result = h;
    }
      else if (function_decl::parameter* p = is_function_parameter(d))
    {
      type_base_sptr parm_type = p->get_type();
      ABG_ASSERT(parm_type);
      std::hash<bool> hash_bool;
      std::hash<unsigned> hash_unsigned;
      hash_t h = hash_type_or_decl(parm_type);
      h = hashing::combine_hashes(h, hash_unsigned(p->get_index()));
      h = hashing::combine_hashes(h, hash_bool(p->get_variadic_marker()));
      result = h;
    }
      else if (class_decl::base_spec *bs = is_class_base_spec(d))
    {
      member_base::hash hash_member;
      std::hash<size_t> hash_size;
      std::hash<bool> hash_bool;
      type_base_sptr type = bs->get_base_class();
      hash_t h = hash_type_or_decl(type);
      h = hashing::combine_hashes(h, hash_member(*bs));
      h = hashing::combine_hashes(h, hash_size(bs->get_offset_in_bits()));
      h = hashing::combine_hashes(h, hash_bool(bs->get_is_virtual()));
      result = h;
    }
      else
    // This is a *really* *SLOW* path.  If it shows up in a
    // performance profile, I bet it'd be a good idea to try to
    // avoid it altogether.
    // TODO: recode this function or get rid of it altogethe.
    abort();
    }
  else
    // We should never get here.
    abort();
  return *result;
}

/// Hash an ABI artifact that is a type.
///
/// This function intends to provides the fastest possible hashing for
/// types while being completely correct.
///
/// Note that if the type artifact has a canonical type, the hash
/// value is going to be the pointer value of the canonical type.
/// Otherwise, this function computes a hash value for the type by
/// recursively walking the type members.  This last code path is
/// possibly *very* slow and should only be used when only handful of
/// types are going to be hashed.
///
/// @param t the type or decl to hash.
///
/// @return the resulting hash value.
size_t
hash_type(const type_base *t)
{return hash_as_canonical_type_or_constant(t);}

/// Hash an ABI artifact that is either a type of a decl.
///
/// @param tod the ABI artifact to hash.
///
/// @return the hash value of the ABI artifact.
size_t
hash_type_or_decl(const type_or_decl_base_sptr& tod)
{return hash_type_or_decl(tod.get());}

/// Get the hash value associated to an IR node.
///
/// Unlike type_or_decl_base::hash_value(), if the IR has no
/// associated hash value, an empty hash value is returned.
///
/// @param artefact the IR node to consider.
///
/// @return the hash value stored on the IR node or an empty hash if
/// no hash value is stored in the @p artefact.
hash_t
peek_hash_value(const type_or_decl_base& artefact)
{
  const type_or_decl_base* artefactp = &artefact;
  if (decl_base *d = is_decl(artefactp))
    {
      d = look_through_decl_only(d);
      if (d->type_or_decl_base::priv_->get_hashing_state()
      == hashing::HASHING_FINISHED_STATE)
    return d->type_or_decl_base::priv_->hash_value_;
    }
  else if (artefact.priv_->get_hashing_state() == hashing::HASHING_FINISHED_STATE)
    return artefact.priv_->hash_value_;

  return hash_t();
}

/// Test if a given type is allowed to be non canonicalized
///
/// This is a subroutine of hash_as_canonical_type_or_constant.
///
/// For now, the only types allowed to be non canonicalized in the
/// system are (typedefs & pointers to) decl-only class/union, the
/// void type and variadic parameter types.
///
/// @return true iff @p t is a one of the only types allowed to be
/// non-canonicalized in the system.
bool
is_non_canonicalized_type(const type_base *t)
{
  if (!t)
    return true;

  return (// The IR nodes for the types below are unique across the
      // entire ABI corpus.  Thus, no need to canonicalize them.
      // Maybe we could say otherwise and canonicalize them once
      // for all so that they can be removed from here.
      is_unique_type(t)

      // An IR node for the types below can be equal to several
      // other types (i.e, a decl-only type t equals a fully
      // defined type of the same name in ODR-supported
      // languages). Hence, they can't be given a canonical type.
      //
      // TODO: Maybe add a mode that would detect ODR violations
      // that would make a decl-only type co-exists with several
      // different definitions of the type in the ABI corpus.
      || is_void_pointer_type_equivalent(t)
      || is_declaration_only_class_or_union_type(t,
                             /*look_through_decl_only=*/true)
      || is_typedef_ptr_or_ref_to_decl_only_class_or_union_type(t));

}

/// Test if a type is unique in the entire environment.
///
/// Examples of unique types are void, void* and variadic parameter
/// types.
///
/// @param t the type to test for.
///
/// @return true iff the type @p t is unique in the entire
/// environment.
bool
is_unique_type(const type_base_sptr& t)
{return is_unique_type(t.get());}

/// Test if a type is unique in the entire environment.
///
/// Examples of unique types are void, void* and variadic parameter
/// types.
///
/// @param t the type to test for.
///
/// @return true iff the type @p t is unique in the entire
/// environment.
bool
is_unique_type(const type_base* t)
{
  if (!t)
    return false;

  const environment& env = t->get_environment();
  return (env.is_void_type(t)
      || env.is_void_pointer_type(t)
      || env.is_variadic_parameter_type(t));
}

/// For a given type, return its exemplar type.
///
/// For a given type, its exemplar type is either its canonical type
/// or the canonical type of the definition type of a given
/// declaration-only type.  If the neither of those two types exist,
/// then the exemplar type is the given type itself.
///
/// @param type the input to consider.
///
/// @return the exemplar type.
type_base*
get_exemplar_type(const type_base* type)
{
  if (decl_base * decl = is_decl(type))
    {
      // Make sure we get the real definition of a decl-only type.
      decl = look_through_decl_only(decl);
      type = is_type(decl);
      ABG_ASSERT(type);
    }
  type_base *exemplar = type->get_naked_canonical_type();
  if (!exemplar)
    {
      // The type has no canonical type.  Let's be sure that it's one
      // of those rare types that are allowed to be non canonicalized
      // in the system.
      exemplar = const_cast<type_base*>(type);
      ABG_ASSERT(is_non_canonicalized_type(exemplar));
    }
  return exemplar;
}

/// Test if a given type is allowed to be non canonicalized
///
/// This is a subroutine of hash_as_canonical_type_or_constant.
///
/// For now, the only types allowed to be non canonicalized in the
/// system are decl-only class/union and the void type.
///
/// @return true iff @p t is a one of the only types allowed to be
/// non-canonicalized in the system.
bool
is_non_canonicalized_type(const type_base_sptr& t)
{return is_non_canonicalized_type(t.get());}

/// Hash a type by either returning the pointer value of its canonical
/// type or by returning a constant if the type doesn't have a
/// canonical type.
///
/// This is a subroutine of hash_type.
///
/// @param t the type to consider.
///
/// @return the hash value.
static size_t
hash_as_canonical_type_or_constant(const type_base *t)
{
  type_base *canonical_type = 0;

  if (t)
    canonical_type = t->get_naked_canonical_type();

  if (!canonical_type)
    {
      // If the type doesn't have a canonical type, maybe it's because
      // it's a declaration-only type?  If that's the case, let's try
      // to get the canonical type of the definition of this
      // declaration.
      decl_base *decl = is_decl(t);
      if (decl
      && decl->get_is_declaration_only()
      && decl->get_naked_definition_of_declaration())
    {
      type_base *definition =
        is_type(decl->get_naked_definition_of_declaration());
      ABG_ASSERT(definition);
      canonical_type = definition->get_naked_canonical_type();
    }
    }

  if (canonical_type)
    return reinterpret_cast<size_t>(canonical_type);

  // If we reached this point, it means we are seeing a
  // non-canonicalized type.  It must be a decl-only class or a void
  // type, otherwise it means that for some weird reason, the type
  // hasn't been canonicalized.  It should be!
  ABG_ASSERT(is_non_canonicalized_type(t));

  return 0xDEADBABE;
}

/// Test if the pretty representation of a given @ref function_decl is
/// lexicographically less then the pretty representation of another
/// @ref function_decl.
///
/// @param f the first @ref function_decl to consider for comparison.
///
/// @param s the second @ref function_decl to consider for comparison.
///
/// @return true iff the pretty representation of @p f is
/// lexicographically less than the pretty representation of @p s.
bool
function_decl_is_less_than(const function_decl &f, const function_decl &s)
{
  string fr = f.get_pretty_representation_of_declarator(),
    sr = s.get_pretty_representation_of_declarator();

  if (fr != sr)
    return fr < sr;

  fr = f.get_pretty_representation(/*internal=*/true),
    sr = s.get_pretty_representation(/*internal=*/true);

  if (fr != sr)
    return fr < sr;

  if (f.get_symbol())
    fr = f.get_symbol()->get_id_string();
  else if (!f.get_linkage_name().empty())
    fr = f.get_linkage_name();

  if (s.get_symbol())
    sr = s.get_symbol()->get_id_string();
  else if (!s.get_linkage_name().empty())
    sr = s.get_linkage_name();

  return fr < sr;
}

/// Test if two types have similar structures, even though they are
/// (or can be) different.
///
/// const and volatile qualifiers are completely ignored.
///
/// typedef are resolved to their definitions; their names are ignored.
///
/// Two indirect types (pointers or references) have similar structure
/// if their underlying types are of the same kind and have the same
/// name.  In the indirect types case, the size of the underlying type
/// does not matter.
///
/// Two direct types (i.e, non indirect) have a similar structure if
/// they have the same kind, name and size.  Two class types have
/// similar structure if they have the same name, size, and if the
/// types of their data members have similar types.
///
/// @param first the first type to consider.
///
/// @param second the second type to consider.
///
/// @param indirect_type whether to do an indirect comparison
///
/// @return true iff @p first and @p second have similar structures.
bool
types_have_similar_structure(const type_base_sptr& first,
                 const type_base_sptr& second,
                 bool indirect_type)
{return types_have_similar_structure(first.get(), second.get(), indirect_type);}

/// Test if two types have similar structures, even though they are
/// (or can be) different.
///
/// const and volatile qualifiers are completely ignored.
///
/// typedef are resolved to their definitions; their names are ignored.
///
/// Two indirect types (pointers, references or arrays) have similar
/// structure if their underlying types are of the same kind and have
/// the same name.  In the indirect types case, the size of the
/// underlying type does not matter.
///
/// Two direct types (i.e, non indirect) have a similar structure if
/// they have the same kind, name and size.  Two class types have
/// similar structure if they have the same name, size, and if the
/// types of their data members have similar types.
///
/// @param first the first type to consider.
///
/// @param second the second type to consider.
///
/// @param indirect_type if true, then consider @p first and @p
/// second as being underlying types of indirect types.  Meaning that
/// their size does not matter.
///
/// @return true iff @p first and @p second have similar structures.
bool
types_have_similar_structure(const type_base* first,
                 const type_base* second,
                 bool indirect_type)
{
  if (!!first != !!second)
    return false;

  if (!first)
    return false;

  // Treat typedefs purely as type aliases and ignore CV-qualifiers.
  first = peel_qualified_or_typedef_type(first);
  second = peel_qualified_or_typedef_type(second);

  // Eliminate all but N of the N^2 comparison cases. This also guarantees the
  // various ty2 below cannot be null.
  if (typeid(*first) != typeid(*second))
    return false;

  // Peel off matching pointers.
  if (const pointer_type_def* ty1 = is_pointer_type(first))
    {
      const pointer_type_def* ty2 = is_pointer_type(second);
      return types_have_similar_structure(ty1->get_pointed_to_type(),
                      ty2->get_pointed_to_type(),
                      /*indirect_type=*/true);
    }

  // Peel off matching references.
  if (const reference_type_def* ty1 = is_reference_type(first))
    {
      const reference_type_def* ty2 = is_reference_type(second);
      if (ty1->is_lvalue() != ty2->is_lvalue())
    return false;
      return types_have_similar_structure(ty1->get_pointed_to_type(),
                      ty2->get_pointed_to_type(),
                      /*indirect_type=*/true);
    }

  // Peel off matching pointer-to-member types.
  if (const ptr_to_mbr_type* ty1 = is_ptr_to_mbr_type(first))
    {
      const ptr_to_mbr_type* ty2 = is_ptr_to_mbr_type(second);
      return (types_have_similar_structure(ty1->get_member_type(),
                       ty2->get_member_type(),
                       /*indirect_type=*/true)
          && types_have_similar_structure(ty1->get_containing_type(),
                          ty2->get_containing_type(),
                          /*indirect_type=*/true));
    }

  if (const type_decl* ty1 = is_type_decl(first))
    {
      const type_decl* ty2 = is_type_decl(second);
      if (!indirect_type)
    if (ty1->get_size_in_bits() != ty2->get_size_in_bits())
      return false;

      return ty1->get_name() == ty2->get_name();
    }

  if (const enum_type_decl* ty1 = is_enum_type(first))
    {
      const enum_type_decl* ty2 = is_enum_type(second);
      if (!indirect_type)
    if (ty1->get_size_in_bits() != ty2->get_size_in_bits())
      return false;

      return (get_name(ty1->get_underlying_type())
          == get_name(ty2->get_underlying_type()));
    }

  if (const class_decl* ty1 = is_class_type(first))
    {
      const class_decl* ty2 = is_class_type(second);
      if (!ty1->get_is_anonymous() && !ty2->get_is_anonymous()
      && ty1->get_name() != ty2->get_name())
    return false;

      if (!indirect_type)
    {
      if ((ty1->get_size_in_bits() != ty2->get_size_in_bits())
          || (ty1->get_non_static_data_members().size()
          != ty2->get_non_static_data_members().size()))
        return false;

      for (class_or_union::data_members::const_iterator
         i = ty1->get_non_static_data_members().begin(),
         j = ty2->get_non_static_data_members().begin();
           (i != ty1->get_non_static_data_members().end()
        && j != ty2->get_non_static_data_members().end());
           ++i, ++j)
        {
          var_decl_sptr dm1 = *i;
          var_decl_sptr dm2 = *j;
          if (!types_have_similar_structure(dm1->get_type().get(),
                        dm2->get_type().get(),
                        indirect_type))
        return false;
        }
    }

      return true;
    }

  if (const union_decl* ty1 = is_union_type(first))
    {
      const union_decl* ty2 = is_union_type(second);
      if (!ty1->get_is_anonymous() && !ty2->get_is_anonymous()
      && ty1->get_name() != ty2->get_name())
    return false;

      if (!indirect_type)
    return ty1->get_size_in_bits() == ty2->get_size_in_bits();

      return true;
    }

  if (const array_type_def* ty1 = is_array_type(first))
    {
      const array_type_def* ty2 = is_array_type(second);
      if (!indirect_type)
    {
      if (ty1->get_size_in_bits() != ty2->get_size_in_bits()
          || ty1->get_dimension_count() != ty2->get_dimension_count())
        return false;

      // Handle int[5][2] vs int[2][5] ...
      //
      // 6.2.5/20 of
      //  https://www.open-std.org/jtc1/sc22/WG14/www/docs/n1256.pdf
      //  says:
      //
      //  "Array types are characterized by their element
      //  type and by the number of elements in the array"
      //
      // and 6.5.2.1/3 says:
      //
      //  "arrays are stored in row-major order (last subscript
      //   varies fastest)."
      //
      // So, let's ensure that all dimensions (sub-ranges) have
      // the same length.

      for (auto r1 = ty1->get_subranges().begin(),
         r2 = ty1->get_subranges().begin();
           (r1 != ty1->get_subranges().end()
        && r2 != ty2->get_subranges().end());
           ++r1, ++r2)
        if ((*r1)->get_length() != (*r2)->get_length())
          return false;
    }

      // ... then compare the elements of the arrays.
      if (!types_have_similar_structure(ty1->get_element_type(),
                    ty2->get_element_type(),
                    /*indirect_type=*/true))
    return false;

      return true;
    }

  if (const array_type_def::subrange_type *ty1 = is_subrange_type(first))
    {
      const array_type_def::subrange_type *ty2 = is_subrange_type(second);
      if (ty1->get_upper_bound() != ty2->get_upper_bound()
      || ty1->get_lower_bound() != ty2->get_lower_bound()
      || ty1->get_language() != ty2->get_language()
      || !types_have_similar_structure(ty1->get_underlying_type(),
                       ty2->get_underlying_type(),
                       indirect_type))
    return false;

      return true;
    }

  if (const function_type* ty1 = is_function_type(first))
    {
      const function_type* ty2 = is_function_type(second);
      if (!types_have_similar_structure(ty1->get_return_type(),
                    ty2->get_return_type(),
                    indirect_type))
    return false;

      if (ty1->get_parameters().size() != ty2->get_parameters().size())
    return false;

      for (function_type::parameters::const_iterator
         i = ty1->get_parameters().begin(),
         j = ty2->get_parameters().begin();
       (i != ty1->get_parameters().end()
        && j != ty2->get_parameters().end());
       ++i, ++j)
    if (!types_have_similar_structure((*i)->get_type(),
                      (*j)->get_type(),
                      indirect_type))
      return false;

      return true;
    }

  // All kinds of type should have been handled at this point.
  ABG_ASSERT_NOT_REACHED;

  return false;
}

/// Look for a data member of a given class, struct or union type and
/// return it.
///
/// The data member is designated by its name.
///
/// @param type the class, struct or union type to consider.
///
/// @param dm_name the name of the data member to lookup.
///
/// @return the data member iff it was found in @type or NULL if no
/// data member with that name was found.
const var_decl*
lookup_data_member(const type_base* type,
           const char* dm_name)

{
  class_or_union *cou = is_class_or_union_type(type);
  if (!cou)
    return 0;

  return cou->find_data_member(dm_name).get();
}

/// Look for a data member of a given class, struct or union type and
/// return it.
///
/// The data member is designated by its name.
///
/// @param type the class, struct or union type to consider.
///
/// @param dm the data member to lookup.
///
/// @return the data member iff it was found in @type or NULL if no
/// data member with that name was found.
const var_decl_sptr
lookup_data_member(const type_base_sptr& type, const var_decl_sptr& dm)
{
  class_or_union_sptr cou = is_class_or_union_type(type);
  if (!cou)
    return var_decl_sptr();

  return cou->find_data_member(dm);
}

/// Get the function parameter designated by its index.
///
/// Note that the first function parameter has index 0.
///
/// @param fun the function to consider.
///
/// @param parm_index the index of the function parameter to get.
///
/// @return the function parameter designated by its index, of NULL if
/// no function parameter with that index was found.
const function_decl::parameter*
get_function_parameter(const decl_base* fun,
               unsigned parm_index)
{
  function_decl* fn = is_function_decl(fun);
  if (!fn)
    return 0;

  const function_decl::parameters &parms = fn->get_type()->get_parameters();
  if (parms.size() <= parm_index)
    return 0;

  return parms[parm_index].get();
}

/// Build the internal name of the underlying type of an enum.
///
/// @param base_name the (unqualified) name of the enum the underlying
/// type is destined to.
///
/// @param is_anonymous true if the underlying type of the enum is to
/// be anonymous.
string
build_internal_underlying_enum_type_name(const string &base_name,
                     bool is_anonymous,
                     uint64_t size)
{
  std::ostringstream o;

  if (is_anonymous)
    o << "unnamed-enum";
  else
    o << "enum-" << base_name;

  o << "-underlying-type-" << size;

  return o.str();
}

/// Find the first data member of a class or union which name matches
/// a regular expression.
///
/// @param t the class or union to consider.
///
/// @param r the regular expression to consider.
///
/// @return the data member matched by @p r or nil if none was found.
var_decl_sptr
find_first_data_member_matching_regexp(const class_or_union& t,
                       const regex::regex_t_sptr& r)
{
  for (auto data_member : t.get_data_members())
    {
      if (regex::match(r, data_member->get_name()))
    return data_member;
    }

  return var_decl_sptr();
}

/// Find the last data member of a class or union which name matches
/// a regular expression.
///
/// @param t the class or union to consider.
///
/// @param r the regular expression to consider.
///
/// @return the data member matched by @p r or nil if none was found.
var_decl_sptr
find_last_data_member_matching_regexp(const class_or_union& t,
                      const regex::regex_t_sptr& regex)
{
  auto d = t.get_data_members().rbegin();
  auto e = t.get_data_members().rend();
  for (; d != e; ++d)
    {
      if (regex::match(regex, (*d)->get_name()))
    return *d;
    }

  return var_decl_sptr();
}

/// Emit the pretty representation of the parameters of a function
/// type.
///
/// @param fn_type the function type to consider.
///
/// @param o the output stream to emit the pretty representation to.
///
/// @param qualified if true, emit fully qualified names.
///
/// @param internal if true, then the result is to be used for the
/// purpose of type canonicalization.
static void
stream_pretty_representation_of_fn_parms(const function_type& fn_type,
                     ostream& o, bool qualified,
                     bool internal)
{
  o << "(";
  if (fn_type.get_parameters().empty())
    o << "void";
  else
    {
      type_base_sptr type;
      auto end = fn_type.get_parameters().end();
      auto first_parm = fn_type.get_first_non_implicit_parm();
      function_decl::parameter_sptr parm;
      const environment& env = fn_type.get_environment();
      for (auto i = fn_type.get_first_non_implicit_parm(); i != end; ++i)
    {
      if (i != first_parm)
        o << ", ";
      parm = *i;
      type = parm->get_type();
      // If the type is a decl-only class, union or enum that has a
      // definition, use the definition instead.  That definition
      // is what is going to be serialized out in ABIXML anyway,
      // so use that for consistency.
      if (decl_base_sptr def = look_through_decl_only(is_decl(type)))
        type = is_type(def);
      if (env.is_variadic_parameter_type(type))
        o << "...";
      else
        o << get_type_name(type, qualified, internal);
    }
    }
  o << ")";
}

/// When constructing the name of a pointer to function type, add the
/// return type to the left of the existing type identifier, and the
/// parameters declarator to the right.
///
/// This function considers the name of the type as an expression.
///
/// The resulting type expr is going to be made of three parts:
/// left_expr inner_expr right_expr.
///
/// Suppose we want to build the type expression representing:
///
///   "an array of pointer to function taking a char parameter and
///    returning an int".
///
/// It's going to look like:
///
///   int(*a[])(char);
///
/// Suppose the caller of this function started to emit the inner
/// "a[]" part of the expression already.  It thus calls this
/// function with that input "a[]" part.  We consider that "a[]" as
/// the "type identifier".
///
/// So the inner_expr is going to be "(*a[])".
///
/// The left_expr part is "int".  The right_expr part is "(char)".
///
/// In other words, this function adds the left_expr and right_expr to
/// the inner_expr.  left_expr and right_expr are called "outer
/// pointer to function type expression".
///
/// This is a sub-routine of @ref pointer_declaration_name() and @ref
/// array_declaration_name()
///
/// @param p the pointer to function type to consider.
///
/// @param input the type-id to use as the inner expression of the
/// overall pointer-to-function type expression
///
/// @param qualified if true then use qualified names in the resulting
/// type name.
///
/// @param internal if true then the resulting type name is going to
/// be used for type canonicalization purposes.
///
/// @return the name of the pointer to function type.
static string
add_outer_pointer_to_fn_type_expr(const type_base* p,
                  const string& input,
                  bool qualified, bool internal)
{
  if (!p)
    return "";

  function_type_sptr pointed_to_fn;
  string star_or_ref;

  if (const pointer_type_def* ptr = is_pointer_type(p))
    {
      pointed_to_fn = is_function_type(ptr->get_pointed_to_type());
      star_or_ref= "*";
    }
  else if (const reference_type_def* ref = is_reference_type(p))
    {
      star_or_ref = "&";
      pointed_to_fn = is_function_type(ref->get_pointed_to_type());
    }

  if (!pointed_to_fn)
    return "";

  if (pointed_to_fn->priv_->is_pretty_printing())
    // We have just detected a cycle while walking the sub-tree of
    // this function type for the purpose of printing its
    // representation.  We need to get out of here pronto or else
    // we'll be spinning endlessly.
    return "";

  // Let's mark thie function type  to signify that we started walking
  // its subtree.  This is to detect potential cycles and avoid
  // looping endlessly.
  pointed_to_fn->priv_->set_is_pretty_printing();

  std::ostringstream left, right, inner;

  inner <<  "(" << star_or_ref  << input << ")";

  type_base_sptr type;
  stream_pretty_representation_of_fn_parms(*pointed_to_fn, right,
                       qualified, internal);

  type_base_sptr return_type = pointed_to_fn->get_return_type();
  string result;

  if (is_npaf_type(return_type)
      || !(is_pointer_to_function_type(return_type)
       || is_pointer_to_array_type(return_type)))
    {
      if (return_type)
    left << get_type_name(return_type, qualified, internal);
      result = left.str() + " " + inner.str() + right.str();
    }
  else if (pointer_type_def_sptr p = is_pointer_to_function_type(return_type))
    {
      string inner_string = inner.str() + right.str();
      result = add_outer_pointer_to_fn_type_expr(p, inner_string,
                         qualified, internal);
    }
  else if (pointer_type_def_sptr p = is_pointer_to_array_type(return_type))
    {
      string inner_string = inner.str() + right.str();
      result = add_outer_pointer_to_array_type_expr(p, inner_string,
                            qualified, internal);
    }
  else
    ABG_ASSERT_NOT_REACHED;

  // Lets unmark this function type to signify that we are done
  // walking its subtree.  This was to detect potential cycles and
  // avoid looping endlessly.
  pointed_to_fn->priv_->unset_is_pretty_printing();
  return result;
}

/// When constructing the name of a pointer to function type, add the
/// return type to the left of the existing type identifier, and the
/// parameters declarator to the right.
///
/// This function considers the name of the type as an expression.
///
/// The resulting type expr is going to be made of three parts:
/// left_expr inner_expr right_expr.
///
/// Suppose we want to build the type expression representing:
///
///   "an array of pointer to function taking a char parameter and
///    returning an int".
///
/// It's going to look like:
///
///   int(*a[])(char);
///
/// Suppose the caller of this function started to emit the inner
/// "a[]" part of the expression already.  It thus calls this
/// function with that input "a[]" part.  We consider that "a[]" as
/// the "type identifier".
///
/// So the inner_expr is going to be "(*a[])".
///
/// The left_expr part is "int".  The right_expr part is "(char)".
///
/// In other words, this function adds the left_expr and right_expr to
/// the inner_expr.  left_expr and right_expr are called "outer
/// pointer to function type expression".
///
/// This is a sub-routine of @ref pointer_declaration_name() and @ref
/// array_declaration_name()
///
/// @param p the pointer to function type to consider.
///
/// @param input the type-id to use as the inner expression of the
/// overall pointer-to-function type expression
///
/// @param qualified if true then use qualified names in the resulting
/// type name.
///
/// @param internal if true then the resulting type name is going to
/// be used for type canonicalization purposes.
///
/// @return the name of the pointer to function type.
static string
add_outer_pointer_to_fn_type_expr(const type_base_sptr& p,
                  const string& input,
                  bool qualified, bool internal)
{return add_outer_pointer_to_fn_type_expr(p.get(), input, qualified, internal);}

/// When constructing the name of a pointer to array type, add the
/// array element type type to the left of the existing type
/// identifier, and the array declarator part to the right.
///
/// This function considers the name of the type as an expression.
///
/// The resulting type expr is going to be made of three parts:
/// left_expr inner_expr right_expr.
///
/// Suppose we want to build the type expression representing:
///
///   "a pointer to an array of int".
///
/// It's going to look like:
///
///   int(*foo)[];
///
/// Suppose the caller of this function started to emit the inner
/// "foo" part of the expression already.  It thus calls this function
/// with that input "foo" part.  We consider that "foo" as the "type
/// identifier".
///
/// So we are passed an input string that is "foo" and it's going to
/// be turned into the inner_expr part, which is going to be "(*foo)".
///
/// The left_expr part is "int".  The right_expr part is "[]".
///
/// In other words, this function adds the left_expr and right_expr to
/// the inner_expr.  left_expr and right_expr are called "outer
/// pointer to array type expression".
///
/// The model of this function was taken from the article "Reading C
/// type declaration", from Steve Friedl at
/// http://unixwiz.net/techtips/reading-cdecl.html.
///
/// This is a sub-routine of @ref pointer_declaration_name() and @ref
/// array_declaration_name()
///
/// @param p the pointer to array type to consider.
///
/// @param input the type-id to start from as the inner part of the
/// final type name.
///
/// @param qualified if true then use qualified names in the resulting
/// type name.
///
/// @param internal if true then the resulting type name is going to
/// be used for type canonicalization purposes.
///
/// @return the name of the pointer to array type.
static string
add_outer_pointer_to_array_type_expr(const type_base* p,
                     const string& input, bool qualified,
                     bool internal)
{
  if (!p)
    return "";

  string star_or_ref;
  type_base_sptr pointed_to_type;

  if (const pointer_type_def *ptr = is_pointer_type(p))
    {
      pointed_to_type = ptr->get_pointed_to_type();
      star_or_ref = "*";
    }
  else if (const reference_type_def *ref = is_reference_type(p))
    {
      pointed_to_type = ref->get_pointed_to_type();
      star_or_ref = "&";
    }

  array_type_def_sptr array = is_array_type(pointed_to_type);
  if (!array)
    return "";

  std::ostringstream left, right, inner;
  inner <<  "(" << star_or_ref  << input << ")";
  right << array->get_subrange_representation();
  string result;

  type_base_sptr array_element_type = array->get_element_type();

  if (is_npaf_type(array_element_type)
      || !(is_pointer_to_function_type(array_element_type)
       || is_pointer_to_array_type(array_element_type)))
    {
      left << get_type_name(array_element_type, qualified, internal);
      result = left.str() + inner.str() + right.str();
    }
  else if (pointer_type_def_sptr p =
       is_pointer_to_function_type(array_element_type))
    {
      string r = inner.str() + right.str();
      result = add_outer_pointer_to_fn_type_expr(p, r, qualified, internal);
    }
  else if (pointer_type_def_sptr p =
       is_pointer_to_array_type(array_element_type))
    {
      string inner_string = inner.str() + right.str();
      result = add_outer_pointer_to_array_type_expr(p, inner_string,
                            qualified, internal);
    }
  else
    ABG_ASSERT_NOT_REACHED;

  return result;
}

/// When constructing the name of a pointer to array type, add the
/// array element type type to the left of the existing type
/// identifier, and the array declarator part to the right.
///
/// This function considers the name of the type as an expression.
///
/// The resulting type expr is going to be made of three parts:
/// left_expr inner_expr right_expr.
///
/// Suppose we want to build the type expression representing:
///
///   "a pointer to an array of int".
///
/// It's going to look like:
///
///   int(*foo)[];
///
/// Suppose the caller of this function started to emit the inner
/// "foo" part of the expression already.  It thus calls this function
/// with that input "foo" part.  We consider that "foo" as the "type
/// identifier".
///
/// So we are passed an input string that is "foo" and it's going to
/// be turned into the inner_expr part, which is going to be "(*foo)".
///
/// The left_expr part is "int".  The right_expr part is "[]".
///
/// In other words, this function adds the left_expr and right_expr to
/// the inner_expr.  left_expr and right_expr are called "outer
/// pointer to array type expression".
///
/// The model of this function was taken from the article "Reading C
/// type declaration", from Steve Friedl at
/// http://unixwiz.net/techtips/reading-cdecl.html.
///
/// This is a sub-routine of @ref pointer_declaration_name() and @ref
/// array_declaration_name()
///
/// @param p the pointer to array type to consider.
///
/// @param input the type-id to start from as the inner part of the
/// final type name.
///
/// @param qualified if true then use qualified names in the resulting
/// type name.
///
/// @param internal if true then the resulting type name is going to
/// be used for type canonicalization purposes.
///
/// @return the name of the pointer to array type.
static string
add_outer_pointer_to_array_type_expr(const type_base_sptr& pointer_to_ar,
                     const string& input, bool qualified,
                     bool internal)
{return add_outer_pointer_to_array_type_expr(pointer_to_ar.get(),
                         input, qualified, internal);}

/// When constructing the name of a pointer to mebmer type, add the
/// return type to the left of the existing type identifier, and the
/// parameters declarator to the right.
///
/// This function considers the name of the type as an expression.
///
/// The resulting type expr is going to be made of three parts:
/// left_expr inner_expr right_expr.
///
/// Suppose we want to build the type expression representing:
///
///   "an array of pointer to member function (of a containing struct
///    X) taking a char parameter and returning an int".
///
/// It's going to look like:
///
///   int (X::* a[])(char);
///
/// Suppose the caller of this function started to emit the inner
/// "a[]" part of the expression already.  It thus calls this
/// function with that input "a[]" part.  We consider that "a[]" as
/// the "type identifier".
///
/// So the inner_expr is going to be "(X::* a[])".
///
/// The left_expr part is "int".  The right_expr part is "(char)".
///
/// In other words, this function adds the left_expr and right_expr to
/// the inner_expr.  left_expr and right_expr are called "outer
/// pointer to member type expression".
///
/// This is a sub-routine of @ref ptr_to_mbr_declaration_name().
///
/// @param p the pointer to member type to consider.
///
/// @param input the type-id to use as the inner expression of the
/// overall pointer-to-member type expression
///
/// @param qualified if true then use qualified names in the resulting
/// type name.
///
/// @param internal if true then the resulting type name is going to
/// be used for type canonicalization purposes.
///
/// @return the name of the pointer to member type.
static string
add_outer_ptr_to_mbr_type_expr(const ptr_to_mbr_type* p,
                   const  string& input, bool qualified,
                   bool internal)
{
  if (!p)
    return "";

  std::ostringstream left, right, inner;
  type_base_sptr void_type = p->get_environment().get_void_type();
  string containing_type_name = get_type_name(p->get_containing_type(),
                          qualified, internal);
  type_base_sptr mbr_type = p->get_member_type();
  string result;
  if (function_type_sptr fn_type = is_function_type(mbr_type))
    {
      inner << "(" << containing_type_name << "::*" << input << ")";
      stream_pretty_representation_of_fn_parms(*fn_type, right,
                           qualified, internal);
      type_base_sptr return_type = fn_type->get_return_type();
      if (!return_type)
    return_type = void_type;
      if (is_npaf_type(return_type)
      || !(is_pointer_to_function_type(return_type)
           || is_pointer_to_array_type(return_type)
           || is_pointer_to_ptr_to_mbr_type(return_type)
           || is_ptr_to_mbr_type(return_type)))
    {
      left << get_type_name(return_type, qualified, internal) << " ";;
      result = left.str() + inner.str() + right.str();
    }
      else if (pointer_type_def_sptr p = is_pointer_type(return_type))
    {
      string inner_str = inner.str() + right.str();
      result = pointer_declaration_name(p, inner_str, qualified, internal);
    }
      else if (ptr_to_mbr_type_sptr p = is_ptr_to_mbr_type(return_type))
    {
      string inner_str = inner.str() + right.str();
      result = add_outer_ptr_to_mbr_type_expr(p, inner_str,
                          qualified, internal);
    }
      else
    ABG_ASSERT_NOT_REACHED;
    }
  else if (ptr_to_mbr_type_sptr ptr_mbr_type = is_ptr_to_mbr_type(mbr_type))
    {
      inner << "(" << containing_type_name << "::*" << input << ")";
      stream_pretty_representation_of_fn_parms(*fn_type, right,
                           qualified, internal);
      string inner_str = inner.str() + right.str();
      result = add_outer_ptr_to_mbr_type_expr(ptr_mbr_type, inner_str,
                          qualified, internal);
    }
  else
    {
      left << get_type_name(p->get_member_type(), qualified, internal) << " ";
      inner << containing_type_name << "::*" << input;
      result = left.str()+ inner.str();
    }

  return result;
}

/// Test if two decls have different names.
///
/// Note that this function takes into account decls whose names are
/// relevant from an ABI standpoint.  For instance, function parameter
/// names are not relevant in that context.
///
/// @param d1 the first declaration to consider.
///
/// @param d2 the second declaration to consider.
///
/// @return true if d1 and d2 have different names.
bool
decl_name_changed(const type_or_decl_base* a1, const type_or_decl_base *a2)
{
  string d1_name, d2_name;

  const decl_base *d1 = dynamic_cast<const decl_base*>(a1);
  if (d1 == 0)
    return false;

  const decl_base *d2 = dynamic_cast<const decl_base*>(a2);
  if (d2 == 0)
    return false;

  if (is_function_parameter(d1) || is_function_parameter(d2))
    // Name changes for fn parms are irrelevant.
    return false;

  d1_name = d1->get_qualified_name();
  d2_name = d2->get_qualified_name();

  return d1_name != d2_name;
}

/// Test if two decls have different names.
///
/// @param d1 the first declaration to consider.
///
/// @param d2 the second declaration to consider.
///
/// @return true if d1 and d2 have different names.
bool
decl_name_changed(const type_or_decl_base_sptr& d1,
          const type_or_decl_base_sptr& d2)
{return decl_name_changed(d1.get(), d2.get());}

/// Test if a diff node carries a change whereby two integral types
/// have different names in a harmless way.
///
/// Basically, if the integral type name change is accompanied by a
/// size change then the change is considered harmful.  If there are
/// modifiers change, the change is considered harmful.
bool
integral_type_has_harmless_name_change(const type_base_sptr& f,
                       const type_base_sptr& s)
{
  if (is_decl(f)
      && is_decl(s)
      && ((is_integral_type(f) && is_integral_type(s))
      || (is_decl(f)->get_name().empty()
          && is_type_decl(f)
          && is_integral_type(s))
      || (is_decl(s)->get_name().empty()
          && is_type_decl(s)
          && is_integral_type(f)))
      && decl_name_changed(is_decl(f), is_decl(s))
      && (f->get_size_in_bits() == s->get_size_in_bits())
      && (f->get_alignment_in_bits() == s->get_alignment_in_bits()))
      return true;

  return false;
}

/// Test if a diff node carries a change whereby two integral types
/// have different names in a harmless way.
///
/// Basically, if the integral type name change is accompanied by a
/// size change then the change is considered harmful.  If there are
/// modifiers change, the change is considered harmful.
bool
integral_type_has_harmless_name_change(const decl_base_sptr& f,
                       const decl_base_sptr& s)
{return integral_type_has_harmless_name_change(is_type(f), is_type(s));}


/// When constructing the name of a pointer to mebmer type, add the
/// return type to the left of the existing type identifier, and the
/// parameters declarator to the right.
///
/// This function considers the name of the type as an expression.
///
/// The resulting type expr is going to be made of three parts:
/// left_expr inner_expr right_expr.
///
/// Suppose we want to build the type expression representing:
///
///   "an array of pointer to member function (of a containing struct
///    X) taking a char parameter and returning an int".
///
/// It's going to look like:
///
///   int (X::* a[])(char);
///
/// Suppose the caller of this function started to emit the inner
/// "a[]" part of the expression already.  It thus calls this
/// function with that input "a[]" part.  We consider that "a[]" as
/// the "type identifier".
///
/// So the inner_expr is going to be "(X::* a[])".
///
/// The left_expr part is "int".  The right_expr part is "(char)".
///
/// In other words, this function adds the left_expr and right_expr to
/// the inner_expr.  left_expr and right_expr are called "outer
/// pointer to member type expression".
///
/// This is a sub-routine of @ref ptr_to_mbr_declaration_name().
///
/// @param p the pointer to member type to consider.
///
/// @param input the type-id to use as the inner expression of the
/// overall pointer-to-member type expression
///
/// @param qualified if true then use qualified names in the resulting
/// type name.
///
/// @param internal if true then the resulting type name is going to
/// be used for type canonicalization purposes.
///
/// @return the name of the pointer to member type.
static string
add_outer_ptr_to_mbr_type_expr(const ptr_to_mbr_type_sptr& p,
                   const string& input, bool qualified,
                   bool internal)
{return add_outer_ptr_to_mbr_type_expr(p.get(), input, qualified, internal);}

/// This adds the outer parts of a pointer to a pointer-to-member
/// expression.
///
/// Please read the comments of @ref add_outer_ptr_to_mbr_type_expr to
/// learn more about this function, which is similar.
///
/// This is a sub-routine of @ref pointer_declaration_name().
///
/// @param a pointer (or reference) to a pointer-to-member type.
///
/// @param input the inner type-id to add the outer parts to.
///
/// @param qualified if true then use qualified names in the resulting
/// type name.
///
/// @param internal if true then the resulting type name is going to
/// be used for type canonicalization purposes.
static string
add_outer_pointer_to_ptr_to_mbr_type_expr(const type_base* p,
                      const string& input, bool qualified,
                      bool internal)
{
  if (!p)
    return "";

  string star_or_ref;
  type_base_sptr pointed_to_type;

  if (const pointer_type_def* ptr = is_pointer_type(p))
    {
      pointed_to_type = ptr->get_pointed_to_type();
      star_or_ref = "*";
    }
  else if (const reference_type_def* ref = is_reference_type(p))
    {
      pointed_to_type= ref->get_pointed_to_type();
      star_or_ref = "&";
    }

  if (!pointed_to_type)
    return "";

  ptr_to_mbr_type_sptr pointed_to_ptr_to_mbr =
    is_ptr_to_mbr_type(pointed_to_type);
  if (!pointed_to_ptr_to_mbr)
    return "";

  std::ostringstream inner;
  inner << star_or_ref << input;
  string result = add_outer_ptr_to_mbr_type_expr(pointed_to_ptr_to_mbr,
                         inner.str(),
                         qualified, internal);
  return result;
}

/// Emit the name of a pointer declaration.
///
/// @param the pointer to consider.
///
/// @param idname the name of the variable that has @p as a type or
/// the id of the type.  If it's empty then the resulting name is
/// going to be the abstract name of the type.
///
/// @param qualified if true then the type name is going to be
/// fully qualified.
///
/// @param internal if true then the type name is going to be used for
/// type canonicalization purposes.
static interned_string
pointer_declaration_name(const type_base* ptr,
             const string& idname,
             bool qualified, bool internal)
{
  if (!ptr)
    return interned_string();

  type_base_sptr pointed_to_type;
  string star_or_ref;
  if (const pointer_type_def* p = is_pointer_type(ptr))
    {
      pointed_to_type = p->get_pointed_to_type();
      star_or_ref = "*";
    }
  else if (const reference_type_def* p = is_reference_type(ptr))
    {
      pointed_to_type = p->get_pointed_to_type();
      star_or_ref = "&";
    }

  if (!pointed_to_type)
    return interned_string();

  string result;
  if (is_npaf_type(pointed_to_type)
      || !(is_function_type(pointed_to_type)
       || is_array_type(pointed_to_type)
       || is_ptr_to_mbr_type(pointed_to_type)))
    {
      result = get_type_name(pointed_to_type,
                 qualified,
                 internal)
    + star_or_ref;

      if (!idname.empty())
    result += idname;
    }
  else
    {
      // derived type
      if (is_function_type(pointed_to_type))
    result = add_outer_pointer_to_fn_type_expr(ptr, idname,
                           qualified, internal);
      else if (is_array_type(pointed_to_type))
    result = add_outer_pointer_to_array_type_expr(ptr, idname,
                              qualified, internal);
      else if (is_ptr_to_mbr_type(pointed_to_type))
    result = add_outer_pointer_to_ptr_to_mbr_type_expr(ptr, idname,
                               qualified, internal);
      else
    ABG_ASSERT_NOT_REACHED;
    }
  return ptr->get_environment().intern(result);
}


/// Emit the name of a pointer declaration.
///
/// @param the pointer to consider.
///
/// @param the name of the variable that has @p as a type.  If it's
/// empty then the resulting name is going to be the abstract name of
/// the type.
///
/// @param qualified if true then the type name is going to be
/// fully qualified.
///
/// @param internal if true then the type name is going to be used for
/// type canonicalization purposes.
static interned_string
pointer_declaration_name(const type_base_sptr& ptr,
             const string& variable_name,
             bool qualified, bool internal)
{return pointer_declaration_name(ptr.get(), variable_name,
                 qualified, internal);}

/// Emit the name of a array declaration.
///
/// @param the array to consider.
///
/// @param the name of the variable that has @p as a type.  If it's
/// empty then the resulting name is going to be the abstract name of
/// the type.
///
/// @param qualified if true then the type name is going to be
/// fully qualified.
///
/// @param internal if true then the type name is going to be used for
/// type canonicalization purposes.
static interned_string
array_declaration_name(const array_type_def* array,
               const string& variable_name,
               bool qualified, bool internal)
{
  if (!array)
    return interned_string();

  type_base_sptr e_type = array->get_element_type();
  string e_type_repr =
    (e_type
     ? get_type_name(e_type, qualified, internal)
     : string("void"));

  string result;
  if (is_ada_language(array->get_language()))
    {
      std::ostringstream o;
      if (!variable_name.empty())
    o << variable_name << " is ";
      o << "array ("
    << array->get_subrange_representation()
    << ") of " << e_type_repr;
      result = o.str();
    }
  else
    {
      if (is_npaf_type(e_type)
      || !(is_pointer_to_function_type(e_type)
           || is_pointer_to_array_type(e_type)
           || is_pointer_to_ptr_to_mbr_type(e_type)
           || is_ptr_to_mbr_type(e_type)))
    {
      result = e_type_repr;
      if (!variable_name.empty())
        result += variable_name;
      result += array->get_subrange_representation();
    }
      else if (pointer_type_def_sptr p = is_pointer_type(e_type))
    {
      string s = variable_name + array->get_subrange_representation();
      result = pointer_declaration_name(p, s, qualified, internal);
    }
      else if (ptr_to_mbr_type_sptr p = is_ptr_to_mbr_type(e_type))
    {
      string s = variable_name + array->get_subrange_representation();
      result = ptr_to_mbr_declaration_name(p, s, qualified, internal);
    }
      else
    ABG_ASSERT_NOT_REACHED;
    }
  return array->get_environment().intern(result);
}

/// Emit the name of a array declaration.
///
/// @param the array to consider.
///
/// @param the name of the variable that has @p as a type.  If it's
/// empty then the resulting name is going to be the abstract name of
/// the type.
///
/// @param qualified if true then the type name is going to be
/// fully qualified.
///
/// @param internal if true then the type name is going to be used for
/// type canonicalization purposes.
static interned_string
array_declaration_name(const array_type_def_sptr& array,
               const string& variable_name,
               bool qualified, bool internal)
{return array_declaration_name(array.get(), variable_name,
                   qualified, internal);}

/// Emit the name of a pointer-to-member declaration.
///
/// @param ptr the pointer-to-member to consider.
///
/// @param variable_name the name of the variable that has @p as a
/// type.  If it's empty then the resulting name is going to be the
/// abstract name of the type.
///
/// @param qualified if true then the type name is going to be
/// fully qualified.
///
/// @param internal if true then the type name is going to be used for
/// type canonicalization purposes.
static interned_string
ptr_to_mbr_declaration_name(const ptr_to_mbr_type* ptr,
                const string& variable_name,
                bool qualified, bool internal)
{
  if (!ptr)
    return interned_string();

  string input = variable_name;
  string result = add_outer_ptr_to_mbr_type_expr(ptr, input,
                         qualified, internal);
  return ptr->get_environment().intern(result);
}

/// Emit the name of a pointer-to-member declaration.
///
/// @param ptr the pointer-to-member to consider.
///
/// @param variable_name the name of the variable that has @p as a
/// type.  If it's empty then the resulting name is going to be the
/// abstract name of the type.
///
/// @param qualified if true then the type name is going to be
/// fully qualified.
///
/// @param internal if true then the type name is going to be used for
/// type canonicalization purposes.
static interned_string
ptr_to_mbr_declaration_name(const ptr_to_mbr_type_sptr& ptr,
                const string& variable_name,
                bool qualified, bool internal)
{
  return ptr_to_mbr_declaration_name(ptr.get(), variable_name,
                     qualified, internal);
}

/// Sort types right before hashing and canonicalizing them.
///
/// @param types the vector of types to sort.
void
sort_types_for_hash_computing_and_c14n(vector<type_base_sptr>& types)
{
  sort_types_for_hash_computing_and_c14n(types.begin(), types.end());
}

bool
ir_traversable_base::traverse(ir_node_visitor&)
{return true;}

// <ir_node_visitor stuff>

/// The private data structure of the ir_node_visitor type.
struct ir_node_visitor::priv
{
  pointer_set visited_ir_nodes;
  bool allow_visiting_already_visited_type_node;

  priv()
    : allow_visiting_already_visited_type_node(true)
  {}
}; // end struct ir_node_visitory::priv

/// Default Constructor of the ir_node_visitor type.
ir_node_visitor::ir_node_visitor()
  : priv_(new priv)
{}

ir_node_visitor::~ir_node_visitor() = default;

/// Set if the walker using this visitor is allowed to re-visit a type
/// node that was previously visited or not.
///
/// @param f if true, then the walker using this visitor is allowed to
/// re-visit a type node that was previously visited.
void
ir_node_visitor::allow_visiting_already_visited_type_node(bool f)
{priv_->allow_visiting_already_visited_type_node = f;}

/// Get if the walker using this visitor is allowed to re-visit a type
/// node that was previously visited or not.
///
/// @return true iff the walker using this visitor is allowed to
/// re-visit a type node that was previously visited.
bool
ir_node_visitor::allow_visiting_already_visited_type_node() const
{return priv_->allow_visiting_already_visited_type_node;}

/// Mark a given type node as having been visited.
///
/// Note that for this function to work, the type node must have been
/// canonicalized.  Otherwise the process is aborted.
///
/// @param p the type to mark as having been visited.
void
ir_node_visitor::mark_type_node_as_visited(type_base *p)
{
  if (allow_visiting_already_visited_type_node())
    return;

  if (p == 0 || type_node_has_been_visited(p))
    return;

  type_base* canonical_type = p->get_naked_canonical_type();
  if (is_non_canonicalized_type(p))
    {
      ABG_ASSERT(!canonical_type);
      canonical_type = p;
    }
    ABG_ASSERT(canonical_type);

  size_t canonical_ptr_value = reinterpret_cast<size_t>(canonical_type);
  priv_->visited_ir_nodes.insert(canonical_ptr_value);
}

/// Un-mark all visited type nodes.
///
/// That is, no type node is going to be considered as having been
/// visited anymore.
///
/// In other words, after invoking this funciton,
/// ir_node_visitor::type_node_has_been_visited() is going to return
/// false on all type nodes.
void
ir_node_visitor::forget_visited_type_nodes()
{priv_->visited_ir_nodes.clear();}

/// Test if a given type node has been marked as visited.
///
/// @param p the type node to consider.
///
/// @return true iff the type node @p p has been marked as visited by
/// the function ir_node_visitor::mark_type_node_as_visited.
bool
ir_node_visitor::type_node_has_been_visited(type_base* p) const
{
  if (allow_visiting_already_visited_type_node())
    return false;

  if (p == 0)
    return false;

  type_base *canonical_type = p->get_naked_canonical_type();
  if (is_non_canonicalized_type(p))
    {
      ABG_ASSERT(!canonical_type);
      canonical_type = p;
    }
  ABG_ASSERT(canonical_type);

  size_t ptr_value = reinterpret_cast<size_t>(canonical_type);
  pointer_set::iterator it = priv_->visited_ir_nodes.find(ptr_value);
  if (it == priv_->visited_ir_nodes.end())
    return false;

  return true;
}

bool
ir_node_visitor::visit_begin(decl_base*)
{return true;}

bool
ir_node_visitor::visit_end(decl_base*)
{return true;}

bool
ir_node_visitor::visit_begin(scope_decl*)
{return true;}

bool
ir_node_visitor::visit_end(scope_decl*)
{return true;}

bool
ir_node_visitor::visit_begin(type_base*)
{return true;}

bool
ir_node_visitor::visit_end(type_base*)
{return true;}

bool
ir_node_visitor::visit_begin(scope_type_decl* t)
{return visit_begin(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_end(scope_type_decl* t)
{return visit_end(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_begin(type_decl* t)
{return visit_begin(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_end(type_decl* t)
{return visit_end(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_begin(namespace_decl* d)
{return visit_begin(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_end(namespace_decl* d)
{return visit_end(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_begin(qualified_type_def* t)
{return visit_begin(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_end(qualified_type_def* t)
{return visit_end(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_begin(pointer_type_def* t)
{return visit_begin(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_end(pointer_type_def* t)
{return visit_end(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_begin(reference_type_def* t)
{return visit_begin(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_end(reference_type_def* t)
{return visit_end(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_begin(ptr_to_mbr_type* t)
{return visit_begin(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_end(ptr_to_mbr_type* t)
{return visit_end(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_begin(array_type_def* t)
{return visit_begin(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_end(array_type_def* t)
{return visit_end(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_begin(array_type_def::subrange_type* t)
{return visit_begin(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_end(array_type_def::subrange_type* t)
{return visit_end(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_begin(enum_type_decl* t)
{return visit_begin(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_end(enum_type_decl* t)
{return visit_end(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_begin(typedef_decl* t)
{return visit_begin(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_end(typedef_decl* t)
{return visit_end(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_begin(function_type* t)
{return visit_begin(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_end(function_type* t)
{return visit_end(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_begin(var_decl* d)
{return visit_begin(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_end(var_decl* d)
{return visit_end(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_begin(function_decl* d)
{return visit_begin(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_end(function_decl* d)
{return visit_end(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_begin(function_decl::parameter* d)
{return visit_begin(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_end(function_decl::parameter* d)
{return visit_end(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_begin(function_tdecl* d)
{return visit_begin(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_end(function_tdecl* d)
{return visit_end(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_begin(class_tdecl* d)
{return visit_begin(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_end(class_tdecl* d)
{return visit_end(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_begin(class_or_union* t)
{return visit_begin(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_end(class_or_union* t)
{return visit_end(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_begin(class_decl* t)
{return visit_begin(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_end(class_decl* t)
{return visit_end(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_begin(union_decl* t)
{return visit_begin(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_end(union_decl* t)
{return visit_end(static_cast<type_base*>(t));}

bool
ir_node_visitor::visit_begin(class_decl::base_spec* d)
{return visit_begin(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_end(class_decl::base_spec* d)
{return visit_end(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_begin(member_function_template* d)
{return visit_begin(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_end(member_function_template* d)
{return visit_end(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_begin(member_class_template* d)
{return visit_begin(static_cast<decl_base*>(d));}

bool
ir_node_visitor::visit_end(member_class_template* d)
{return visit_end(static_cast<decl_base*>(d));}

// </ir_node_visitor stuff>

// <debugging facilities>

/// Generate a different string at each invocation.
///
/// @return the resulting string.
static string
get_next_string()
{
  static __thread size_t counter;
  ++counter;
  std::ostringstream o;
  o << counter;
  return o.str();
}

/// A hashing functor for a @ref function_decl
struct function_decl_hash
{
  size_t operator()(const function_decl* f) const
  {return reinterpret_cast<size_t>(f);}

  size_t operator()(const function_decl_sptr& f) const
  {return operator()(f.get());}
};

/// Convenience typedef for a hash map of pointer to function_decl and
/// string.
typedef unordered_map<const function_decl*, string,
              function_decl_hash,
              function_decl::ptr_equal> fns_to_str_map_type;

/// Return a string associated to a given function.  Two functions
/// that compare equal would yield the same string, as far as this
/// routine is concerned.  And two functions that are different would
/// yield different strings.
///
/// This is used to debug core diffing issues on functions.  The
/// sequence of strings can be given to the 'testdiff2' program that
/// is in the tests/ directory of the source tree, to reproduce core
/// diffing issues on string and thus ease the debugging.
///
/// @param fn the function to generate a string for.
///
/// @param m the function_decl* <-> string map to be used by this
/// function to generate strings associated to a function.
///
/// @return the resulting string.
static const string&
fn_to_str(const function_decl* fn,
      fns_to_str_map_type& m)
{
  fns_to_str_map_type::const_iterator i = m.find(fn);
  if (i != m.end())
    return i->second;
  string s = get_next_string();
  return m[fn]= s;
}

/// Generate a sequence of string that matches a given sequence of
/// function.  In the resulting sequence, each function is "uniquely
/// representated" by a string.  For instance, if the same function "foo"
/// appears at indexes 1 and 3, then the same string 'schmurf' (okay,
/// we don't care about the actual string) would appear at index 1 and 3.
///
/// @param begin the beginning of the sequence of functions to consider.
///
/// @param end the end of the sequence of functions.  This points to
/// one-passed-the-end of the actual sequence.
///
/// @param m the function_decl* <-> string map to be used by this
/// function to generate strings associated to a function.
///
/// @param o the output stream where to emit the generated list of
/// strings to.
static void
fns_to_str(vector<function_decl*>::const_iterator begin,
       vector<function_decl*>::const_iterator end,
       fns_to_str_map_type& m,
       std::ostream& o)
{
  vector<function_decl*>::const_iterator i;
  for (i = begin; i != end; ++i)
    o << "'" << fn_to_str(*i, m) << "' ";
}

/// For each sequence of functions given in argument, generate a
/// sequence of string that matches a given sequence of function.  In
/// the resulting sequence, each function is "uniquely representated"
/// by a string.  For instance, if the same function "foo" appears at
/// indexes 1 and 3, then the same string 'schmurf' (okay, we don't
/// care about the actual string) would appear at index 1 and 3.
///
/// @param a_begin the beginning of the sequence of functions to consider.
///
/// @param a_end the end of the sequence of functions.  This points to
/// one-passed-the-end of the actual sequence.
///
/// @param b_begin the beginning of the second sequence of functions
/// to consider.
///
/// @param b_end the end of the second sequence of functions.
///
/// @param m the function_decl* <-> string map to be used by this
/// function to generate strings associated to a function.
///
/// @param o the output stream where to emit the generated list of
/// strings to.
static void
fns_to_str(vector<function_decl*>::const_iterator a_begin,
       vector<function_decl*>::const_iterator a_end,
       vector<function_decl*>::const_iterator b_begin,
       vector<function_decl*>::const_iterator b_end,
       fns_to_str_map_type& m,
       std::ostream& o)
{
  fns_to_str(a_begin, a_end, m, o);
  o << "->|<- ";
  fns_to_str(b_begin, b_end, m, o);
  o << "\n";
}

/// For each sequence of functions given in argument, generate a
/// sequence of string that matches a given sequence of function.  In
/// the resulting sequence, each function is "uniquely representated"
/// by a string.  For instance, if the same function "foo" appears at
/// indexes 1 and 3, then the same string 'schmurf' (okay, we don't
/// care about the actual string) would appear at index 1 and 3.
///
/// @param a_begin the beginning of the sequence of functions to consider.
///
/// @param a_end the end of the sequence of functions.  This points to
/// one-passed-the-end of the actual sequence.
///
/// @param b_begin the beginning of the second sequence of functions
/// to consider.
///
/// @param b_end the end of the second sequence of functions.
///
/// @param o the output stream where to emit the generated list of
/// strings to.
void
fns_to_str(vector<function_decl*>::const_iterator a_begin,
       vector<function_decl*>::const_iterator a_end,
       vector<function_decl*>::const_iterator b_begin,
       vector<function_decl*>::const_iterator b_end,
       std::ostream& o)
{
  fns_to_str_map_type m;
  fns_to_str(a_begin, a_end, b_begin, b_end, m, o);
}

// </debugging facilities>

// </class template>

}// end namespace ir
}//end namespace abigail

namespace
{

/// Update the qualified parent name, qualified name and scoped name
/// of a tree decl node.
///
/// @return true if the tree walking should continue, false otherwise.
///
/// @param d the tree node to take in account.
bool
qualified_name_setter::do_update(abigail::ir::decl_base* d)
{
  std::string parent_qualified_name;
  abigail::ir::scope_decl* parent = d->get_scope();
  if (parent)
    d->priv_->qualified_parent_name_ = parent->get_qualified_name();
  else
    d->priv_->qualified_parent_name_ = abigail::interned_string();

  const abigail::ir::environment& env = d->get_environment();

  if (!d->priv_->qualified_parent_name_.empty())
    {
      if (d->get_name().empty())
    d->priv_->qualified_name_ = abigail::interned_string();
      else
    {
      d->priv_->qualified_name_ =
        env.intern(d->priv_->qualified_parent_name_ + "::" + d->get_name());
      d->priv_->internal_qualified_name_ = env.intern(d->get_name());
    }
    }
  // Make sure the internal qualified name (used for type
  // canonicalization puroses) is always the qualified name.  For
  // integral/real types however, only the non qualified type is used.
  if (!is_integral_type(d))
    d->priv_->internal_qualified_name_ = d->priv_->qualified_name_;

  if (d->priv_->scoped_name_.empty())
    {
      if (parent
      && !parent->get_is_anonymous()
      && !parent->get_name().empty())
    d->priv_->scoped_name_ =
      env.intern(parent->get_name() + "::" + d->get_name());
      else
    d->priv_->scoped_name_ =
      env.intern(d->get_name());
    }

  if (!is_scope_decl(d))
    return false;

  return true;
}

/// This is called when we start visiting a decl node, during the
/// udpate of the qualified name of a given sub-tree.
///
/// @param d the decl node we are visiting.
///
/// @return true iff the traversal should keep going.
bool
qualified_name_setter::visit_begin(abigail::ir::decl_base* d)
{return do_update(d);}

/// This is called when we start visiting a type node, during the
/// udpate of the qualified name of a given sub-tree.
///
/// @param d the decl node we are visiting.
///
/// @return true iff the traversal should keep going.
bool
qualified_name_setter::visit_begin(abigail::ir::type_base* t)
{
  if (abigail::ir::decl_base* d = get_type_declaration(t))
    return do_update(d);
  return false;
}
}// end anonymous namespace.