abg-ir.h

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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// -*- Mode: C++ -*-
//
// Copyright (C) 2013-2023 Red Hat, Inc.
//
// Author: Dodji Seketeli
 
/// @file
///
/// Types of the main internal representation of libabigail.
///
/// This internal representation abstracts the artifacts that make up
/// an application binary interface.
 
#ifndef __ABG_IR_H__
#define __ABG_IR_H__
 
#include <assert.h>
#include <stdint.h>
#include <cstdlib>
#include <functional>
#include <set>
#include <unordered_map>
#include "abg-cxx-compat.h"
#include "abg-fwd.h"
#include "abg-hash.h"
#include "abg-traverse.h"
#include "abg-config.h"
 
/// @file
///
/// This file contains the declarations of the Internal Representation
/// of libabigail.
 
/// @defgroup Memory Memory management
/// @{
///
/// How objects' lifetime is handled in libabigail.
///
/// For memory management and garbage collection of libabigail's IR
/// artifacts, we use std::shared_ptr and std::weak_ptr.
///
/// When manipulating these IR artifacts, there are a few rules to keep in
/// mind.
///
/// <b>The declaration for a type is owned by only one scope </b>
///
/// This means that for each instance of abigail::type_base (a type) there
/// is an instance of abigail::scope_decl that owns a @ref
/// abigail::decl_base_sptr (a shared pointer to an abigail::decl_base)
/// that points to the declaration of that type.  The
/// abigail::type_base_sptr is added to the scope using the function
/// abigail::add_decl_to_scope().
///
/// There is a kind of type that is usually not syntactically owned by
/// a scope: it's function type.  In libabigail, function types are
/// represented by abigail::function_type and abigail::method_type.
/// These types must be owned by the translation unit they originate
/// from.  Adding them to the translation unit must be done by a call
/// to the method function
/// abigail::translation::bind_function_type_life_time().
///
/// <b> A declaration that has a type does NOT own the type </b>
///
/// This means that, for instance, in an abigail::var_decl (a variable
/// declaration), the type of the declaration is not owned by the
/// declaration.  In other (concrete) words, the variable declaration
/// doesn't have a shared pointer to the type.  Rather, it has a *weak*
/// pointer to its type.  That means that it has a data member of type
/// abigail::type_base_wptr that contains the type of the declaration.
///
/// But then abigail::var_decl::get_type() returns a shared pointer that
/// is constructed from the internal weak pointer to the type.  That way,
/// users of the type of the var can own a temporary reference on it and
/// be assured that the type's life time is long enough for their need.
///
/// Likewise, data members, function and template parameters similarly
/// have weak pointers on their type.
///
/// If, for a reason, you really need to keep a type alive for the
/// entire lifetime of the type system, then you can bind the life
/// time of that type to the life time of the @ref environment that is
/// supposed to outlive the type system.  You do that by passing the
/// type to the function environment::keep_type_alive().
///
/// @}
 
namespace abigail
{
 
/// The namespace of the internal representation of ABI artifacts like
/// types and decls.
namespace ir
{
 
// Inject some std types in here.
using std::unordered_map;
 
/// A convenience typedef for an unordered set of pointer values
typedef unordered_set<uintptr_t> pointer_set;
 
/// Functor to hash a canonical type by using its pointer value.
struct canonical_type_hash
{
  size_t operator()(const type_base_sptr& l) const;
  size_t operator()(const type_base *l) const;
}; //end struct canonical_type_hash
 
/// Helper typedef for an unordered set of type_base_sptr which uses
/// pointer value to tell its members appart, because the members are
/// canonical types.
typedef unordered_set<type_base_sptr,
              canonical_type_hash> canonical_type_sptr_set_type;
 
/// Helper typedef for a vector of pointer to type_base.
typedef vector<type_base*> type_base_ptrs_type;
 
/// Helper typedef for a vector of shared pointer to a type_base.
typedef vector<type_base_sptr> type_base_sptrs_type;
 
void
sort_types(const canonical_type_sptr_set_type& types,
       vector<type_base_sptr>& result);
 
/// This is an abstraction of the set of resources necessary to manage
/// several aspects of the internal representations of the Abigail
/// library.
///
/// An environment can be seen as the boundaries in which all related
/// Abigail artifacts live.  So before doing anything using this
/// library, the first thing to create is, well, you know it now, an
/// environment.
///
/// Note that the lifetime of environment objects must be longer than
/// the lifetime of any other type in the Abigail system.  So a given
/// instance of @ref environment must stay around as long as you are
/// using libabigail.  It's only when you are done using the library
/// that you can de-allocate the environment instance.
class environment
{
public:
  struct priv;
  std::unique_ptr<priv> priv_;
 
  /// A convenience typedef for a map of canonical types.  The key is
  /// the pretty representation string of a particular type and the
  /// value is the vector of canonical types that have the same pretty
  /// representation string.
  typedef std::unordered_map<string, std::vector<type_base_sptr> >
      canonical_types_map_type;
 
  environment();
 
  virtual ~environment();
 
  canonical_types_map_type&
  get_canonical_types_map();
 
  const canonical_types_map_type&
  get_canonical_types_map() const;
 
  const type_base_sptr&
  get_void_type() const;
 
  const type_base_sptr&
  get_variadic_parameter_type() const;
 
  static string&
  get_variadic_parameter_type_name();
 
  bool
  canonicalization_is_done() const;
 
  void
  canonicalization_is_done(bool);
 
  bool
  do_on_the_fly_canonicalization() const;
 
  void
  do_on_the_fly_canonicalization(bool f);
 
  bool
  decl_only_class_equals_definition() const;
 
  void
  decl_only_class_equals_definition(bool f) const;
 
  bool
  is_void_type(const type_base_sptr&) const;
 
  bool
  is_void_type(const type_base*) const;
 
  bool
  is_variadic_parameter_type(const type_base*) const;
 
  bool
  is_variadic_parameter_type(const type_base_sptr&) const;
 
  interned_string
  intern(const string&) const;
 
  const config&
  get_config() const;
 
  bool
  user_set_analyze_exported_interfaces_only() const;
 
  void
  analyze_exported_interfaces_only(bool f);
 
  bool
  analyze_exported_interfaces_only() const;
 
#ifdef WITH_DEBUG_SELF_COMPARISON
  void
  set_self_comparison_debug_input(const corpus_sptr& corpus);
 
  void
  get_self_comparison_debug_inputs(corpus_sptr& first_corpus,
                   corpus_sptr& second_corpus);
 
  void
  self_comparison_debug_is_on(bool);
 
  bool
  self_comparison_debug_is_on() const;
#endif
 
#ifdef WITH_DEBUG_TYPE_CANONICALIZATION
  void
  debug_type_canonicalization_is_on(bool flag);
 
  bool
  debug_type_canonicalization_is_on() const;
 
  void
  debug_die_canonicalization_is_on(bool flag);
 
  bool
  debug_die_canonicalization_is_on() const;
#endif
 
  vector<type_base_sptr>* get_canonical_types(const char* name);
 
  type_base* get_canonical_type(const char* name, unsigned index);
 
#ifdef WITH_DEBUG_SELF_COMPARISON
  const unordered_map<string, uintptr_t>&
  get_type_id_canonical_type_map() const;
 
  unordered_map<string, uintptr_t>&
  get_type_id_canonical_type_map();
 
  const unordered_map<uintptr_t, string>&
  get_pointer_type_id_map() const;
 
  unordered_map<uintptr_t, string>&
  get_pointer_type_id_map();
 
  string
  get_type_id_from_pointer(uintptr_t ptr) const;
 
  string
  get_type_id_from_type(const type_base *ptr) const;
 
  uintptr_t
  get_canonical_type_from_type_id(const char*) const;
#endif
 
  friend class class_or_union;
  friend class class_decl;
  friend class function_type;
 
  friend void keep_type_alive(type_base_sptr);
}; // end class environment
 
class location_manager;
/// @brief The source location of a token.
///
/// This represents the location of a token coming from a given
/// translation unit.  This location is actually an abstraction of
/// cursor in the table of all the locations of all the tokens of the
/// translation unit.  That table is managed by the @ref location_manager
/// type.  To get the file path, line and column numbers associated to
/// a given instance of @ref location, you need to use the
/// location_manager::expand_location method.
class location
{
  unsigned      value_;
  // The location manager to use to decode the value above.  There is
  // one location manager per translation unit, and the location
  // manager's life time is managed by its translation unit.
  location_manager* loc_manager_;
  // Whether the location is artificial.  Being artificial means that
  // the location wasn't generated by the original emitter of the
  // metadata (i.e, the compiler if the metadata is debug info).  For
  // instance, implicit location derived from the position of XML
  // elements in the abixml file is represented as artificial
  // locations.
  bool          is_artificial_;
 
  location(unsigned v, location_manager* m)
    : value_(v), loc_manager_(m), is_artificial_(false)
  {}
 
  /// Get the location manager to use to decode the value of this
  /// location.
  ///
  /// @return the location manager for the current location value.
  location_manager*
  get_location_manager() const
  {return loc_manager_;}
 
public:
 
  /// Test if the location is artificial.
  ///
  /// Being artificial means that the location wasn't generated by the
  /// original emitter of the metadata (i.e, the compiler if the
  /// metadata is debug info).  For instance, the implicit location
  /// derived from the position of a given XML element in the abixml
  /// file is represented as artificial locations.  The same XML
  /// element might carry a non-artificial (natural?) location that was
  /// originally emitted by the compiler that generated the original
  /// debug info the abixml file is derived from.
  ///
  /// @return true iff the location is artificial.
  bool
  get_is_artificial() const
  {return is_artificial_;}
 
  /// Set the artificial-ness of the location.
  ///
  /// Being artificial means that the location wasn't generated by the
  /// original emitter of the metadata (i.e, the compiler if the
  /// metadata is debug info).  For instance, the implicit location
  /// derived from the position of a given XML element in the abixml
  /// file is represented as artificial locations.  The same XML
  /// element might carry a non-artificial (natural?) location that
  /// was originally emitted by the compiler that generated the
  /// original debug info the abixml file is derived from.
  ///
  /// @param f the new artificial-ness state.
  void
  set_is_artificial(bool f)
  {is_artificial_ = f;}
 
  /// Copy constructor of the location.
  ///
  /// @param l the location to copy from.
  location(const location& l)
    : value_(l.value_),
      loc_manager_(l.loc_manager_),
      is_artificial_(l.is_artificial_)
  {}
 
  /// Assignment operator of the location.
  ///
  /// @param l the location to assign to the current one.
  location&
  operator=(const location& l)
  {
    value_ = l.value_;
    loc_manager_ = l.loc_manager_;
    is_artificial_ = l.is_artificial_;
    return *this;
  }
 
  /// Default constructor for the @ref location type.
  location()
    : value_(), loc_manager_(), is_artificial_()
  {}
 
  /// Get the value of the location.
  unsigned
  get_value() const
  {return value_;}
 
  /// Convert the location into a boolean.
  ///
  /// @return true iff the value of the location is different from
  /// zero.
  operator bool() const
  {return !!value_;}
 
  /// Equality operator of the @ref location type.
  ///
  /// @param other the other location to compare against.
  ///
  /// @return true iff both locations are equal.
  bool
  operator==(const location &other) const
  {return value_ == other.value_;}
 
  /// "Less than" operator of the @ref location type.
  ///
  /// @parm other the other location type to compare against.
  ///
  /// @return true iff the current instance is less than the @p other
  /// one.
  bool
  operator<(const location &other) const
  {return value_ < other.value_;}
 
  /// Expand the current location into a tripplet file path, line and
  /// column number.
  ///
  /// @param path the output parameter this function sets the expanded
  /// path to.
  ///
  /// @param line the output parameter this function sets the expanded
  /// line number to.
  ///
  /// @param column the output parameter this function sets the
  /// expanded column number to.
  void
  expand(std::string& path, unsigned& line, unsigned& column) const;
 
  string
  expand(void) const;
 
  friend class location_manager;
}; // end class location
 
/// @brief The entry point to manage locations.
///
/// This type keeps a table of all the locations for tokens of a
/// given translation unit.
class location_manager
{
  struct priv;
  std::unique_ptr<priv> priv_;
 
public:
 
  location_manager();
 
  ~location_manager();
 
  location
  create_new_location(const std::string& fle, size_t lne, size_t col);
 
  void
  expand_location(const location& location, std::string& path,
          unsigned& line, unsigned& column) const;
};
 
/// The base of an entity of the intermediate representation that is
/// to be traversed.
struct ir_traversable_base : public traversable_base
{
  /// Traverse a given IR node and its children, calling an visitor on
  /// each node.
  ///
  /// @param v the visitor to call on each traversed node.
  ///
  /// @return true if the all the IR node tree was traversed.
  virtual bool
  traverse(ir_node_visitor& v);
}; // end class ir_traversable_base
 
/// The hashing functor for using instances of @ref type_or_decl_base
/// as values in a hash map or set.
struct type_or_decl_hash
{
 
  /// Function-call Operator to hash the string representation of an
  /// ABI artifact.
  ///
  /// @param artifact the ABI artifact to hash.
  ///
  /// @return the hash value of the string representation of @p
  /// artifact.
  size_t
  operator()(const type_or_decl_base *artifact) const
  {
    string repr =  get_pretty_representation(artifact);
    std::hash<string> do_hash;
    return do_hash(repr);
  }
 
  /// Function-call Operator to hash the string representation of an
  /// ABI artifact.
  ///
  /// @param artifact the ABI artifact to hash.
  ///
  /// @return the hash value of the string representation of @p
  /// artifact.
  size_t
  operator()(const type_or_decl_base_sptr& artifact) const
  {return operator()(artifact.get());}
}; // end struct type_or_decl_hash
 
/// The comparison functor for using instances of @ref
/// type_or_decl_base as values in a hash map or set.
struct type_or_decl_equal
{
 
  /// The function-call operator to compare the string representations
  /// of two ABI artifacts.
  ///
  /// @param l the left hand side ABI artifact operand of the
  /// comparison.
  ///
  /// @param r the right hand side ABI artifact operand of the
  /// comparison.
  ///
  /// @return true iff the string representation of @p l equals the one
  /// of @p r.
  bool
  operator()(const type_or_decl_base *l, const type_or_decl_base *r) const
  {
    string repr1 = get_pretty_representation(l);
    string repr2 = get_pretty_representation(r);
 
    return repr1 == repr2;
  }
 
  /// The function-call operator to compare the string representations
  /// of two ABI artifacts.
  ///
  /// @param l the left hand side ABI artifact operand of the
  /// comparison.
  ///
  /// @param r the right hand side ABI artifact operand of the
  /// comparison.
  ///
  /// @return true iff the string representation of @p l equals the one
  /// of @p r.
  bool
  operator()(const type_or_decl_base_sptr &l,
         const type_or_decl_base_sptr &r) const
  {return operator()(l.get(), r.get());}
}; // end type_or_decl_equal
 
/// A convenience typedef for a hash set of type_or_decl_base_sptr
typedef unordered_set<type_or_decl_base_sptr,
              type_or_decl_hash,
              type_or_decl_equal> artifact_sptr_set_type;
 
/// A convenience typedef for a hash set of const type_or_decl_base*
typedef unordered_set<const type_or_decl_base*,
              type_or_decl_hash,
              type_or_decl_equal> artifact_ptr_set_type;
 
/// A convenience typedef for a map which key is a string and which
/// value is a @ref type_base_wptr.
typedef unordered_map<string, type_base_wptr> string_type_base_wptr_map_type;
 
/// A convenience typedef for a map which key is a string and which
/// value is a @ref type_base_sptr.
typedef unordered_map<string, type_base_sptr> string_type_base_sptr_map_type;
 
/// A convenience typedef for a map which key is an @ref
/// interned_string and which value is a @ref type_base_wptr.
typedef unordered_map<interned_string, type_base_wptr, hash_interned_string>
istring_type_base_wptr_map_type;
 
/// A convenience typedef for a map which key is an @ref
/// interned_string and which value is a @ref type_base_wptr.
typedef unordered_map<interned_string,
              type_or_decl_base_sptr,
              hash_interned_string>
istring_type_or_decl_base_sptr_map_type;
 
/// This is a type that aggregates maps of all the kinds of types that
/// are supported by libabigail.
///
/// For instance, the type_maps contains a map of string to basic
/// type, a map of string to class type, a map of string to union
/// types, etc.  The key of a map entry is the pretty representation
/// of the type, and the value of the map entry is the type.
class type_maps
{
  struct priv;
  std::unique_ptr<priv> priv_;
 
public:
 
  type_maps();
 
  ~type_maps();
 
  bool
  empty() const;
 
  const istring_type_base_wptrs_map_type&
  basic_types() const;
 
  istring_type_base_wptrs_map_type&
  basic_types();
 
  const istring_type_base_wptrs_map_type&
  class_types() const;
 
  istring_type_base_wptrs_map_type&
  class_types();
 
  istring_type_base_wptrs_map_type&
  union_types();
 
  const istring_type_base_wptrs_map_type&
  union_types() const;
 
  istring_type_base_wptrs_map_type&
  enum_types();
 
  const istring_type_base_wptrs_map_type&
  enum_types() const;
 
  istring_type_base_wptrs_map_type&
  typedef_types();
 
  const istring_type_base_wptrs_map_type&
  typedef_types() const;
 
  istring_type_base_wptrs_map_type&
  qualified_types();
 
  const istring_type_base_wptrs_map_type&
  qualified_types() const;
 
  istring_type_base_wptrs_map_type&
  pointer_types();
 
  const istring_type_base_wptrs_map_type&
  pointer_types() const;
 
  istring_type_base_wptrs_map_type&
  reference_types();
 
  const istring_type_base_wptrs_map_type&
  reference_types() const;
 
  istring_type_base_wptrs_map_type&
  array_types();
 
  const istring_type_base_wptrs_map_type&
  array_types() const;
 
  const istring_type_base_wptrs_map_type&
  subrange_types() const;
 
  istring_type_base_wptrs_map_type&
  subrange_types();
 
  istring_type_base_wptrs_map_type&
  function_types();
 
  const istring_type_base_wptrs_map_type&
  function_types() const;
 
  const vector<type_base_wptr>&
  get_types_sorted_by_name() const;
}; // end class type_maps;
 
/// This is the abstraction of the set of relevant artefacts (types,
/// variable declarations, functions, templates, etc) bundled together
/// into a translation unit.
class translation_unit : public traversable_base
{
  struct priv;
  std::unique_ptr<priv> priv_;
 
  // Forbidden
  translation_unit() = delete;
 
public:
  /// Convenience typedef for a shared pointer on a @ref global_scope.
  typedef shared_ptr<scope_decl> global_scope_sptr;
 
  /// The language of the translation unit.
  enum language
  {
    LANG_UNKNOWN = 0,
    LANG_Cobol74,
    LANG_Cobol85,
    LANG_C89,
    LANG_C99,
    LANG_C11,
    LANG_C,
    LANG_C_plus_plus_03,
    LANG_C_plus_plus_11,
    LANG_C_plus_plus_14,
    LANG_C_plus_plus,
    LANG_ObjC,
    LANG_ObjC_plus_plus,
    LANG_Fortran77,
    LANG_Fortran90,
    LANG_Fortran95,
    LANG_Ada83,
    LANG_Ada95,
    LANG_Pascal83,
    LANG_Modula2,
    LANG_Java,
    LANG_PLI,
    LANG_UPC,
    LANG_D,
    LANG_Python,
    LANG_Go,
    LANG_Rust,
    LANG_Mips_Assembler
  };
 
public:
  translation_unit(const ir::environment&   env,
           const std::string&       path,
           char         address_size = 0);
 
  virtual ~translation_unit();
 
  const environment&
  get_environment() const;
 
  language
  get_language() const;
 
  void
  set_language(language l);
 
  const std::string&
  get_path() const;
 
  void
  set_path(const string&);
 
  const std::string&
  get_compilation_dir_path() const;
 
  void
  set_compilation_dir_path(const std::string&);
 
  const std::string&
  get_absolute_path() const;
 
  void
  set_corpus(corpus*);
 
  const corpus*
  get_corpus() const;
 
  corpus*
  get_corpus();
 
  const scope_decl_sptr&
  get_global_scope() const;
 
  scope_decl_sptr&
  get_global_scope();
 
  const type_maps&
  get_types() const;
 
  type_maps&
  get_types();
 
  const vector<function_type_sptr>&
  get_live_fn_types() const;
 
  location_manager&
  get_loc_mgr();
 
  const location_manager&
  get_loc_mgr() const;
 
  bool
  is_empty() const;
 
  char
  get_address_size() const;
 
  void
  set_address_size(char);
 
  bool
  is_constructed() const;
 
  void
  set_is_constructed(bool);
 
  bool
  operator==(const translation_unit&) const;
 
  bool
  operator!=(const translation_unit&) const;
 
  void
  bind_function_type_life_time(function_type_sptr) const;
 
  virtual bool
  traverse(ir_node_visitor& v);
 
  friend function_type_sptr
  lookup_function_type_in_translation_unit(const function_type& t,
                       const translation_unit& tu);
 
  friend function_type_sptr
  synthesize_function_type_from_translation_unit(const function_type& fn_type,
                         translation_unit& tu);
 
  friend type_base_sptr
  synthesize_type_from_translation_unit(const type_base_sptr& type,
                    translation_unit& tu);
};//end class translation_unit
 
/// A comparison functor to compare translation units based on their
/// absolute paths.
struct shared_translation_unit_comp
{
  /// Compare two translations units based on their absolute paths.
  ///
  /// @param lhs the first translation unit to consider for the
  /// comparison.
  ///
  /// @param rhs the second translatin unit to consider for the
  /// comparison.
  bool
  operator()(const translation_unit_sptr& lhs,
         const translation_unit_sptr& rhs) const
  {return lhs->get_absolute_path() < rhs->get_absolute_path();}
}; // end struct shared_translation_unit_comp
 
/// Convenience typedef for an ordered set of @ref
/// translation_unit_sptr.
typedef std::set<translation_unit_sptr,
         shared_translation_unit_comp> translation_units;
 
string
translation_unit_language_to_string(translation_unit::language);
 
translation_unit::language
string_to_translation_unit_language(const string&);
 
bool
is_c_language(translation_unit::language l);
 
bool
is_cplus_plus_language(translation_unit::language l);
 
bool
is_java_language(translation_unit::language l);
 
bool
is_ada_language(translation_unit::language l);
 
bool
operator==(const translation_unit_sptr&, const translation_unit_sptr&);
 
bool
operator!=(const translation_unit_sptr&, const translation_unit_sptr&);
 
/// Access specifier for class members.
enum access_specifier
{
  no_access,
  public_access,
  protected_access,
  private_access,
};
 
class elf_symbol;
/// A convenience typedef for a shared pointer to elf_symbol.
typedef shared_ptr<elf_symbol> elf_symbol_sptr;
 
/// A convenience typedef for a weak pointer to elf_symbol.
typedef weak_ptr<elf_symbol> elf_symbol_wptr;
 
/// Convenience typedef for a map which key is a string and which
/// value if the elf symbol of the same name.
typedef std::unordered_map<string, elf_symbol_sptr>
string_elf_symbol_sptr_map_type;
 
/// Convenience typedef for a shared pointer to an
/// string_elf_symbol_sptr_map_type.
typedef shared_ptr<string_elf_symbol_sptr_map_type>
string_elf_symbol_sptr_map_sptr;
 
/// Convenience typedef for a vector of elf_symbol
typedef std::vector<elf_symbol_sptr> elf_symbols;
 
/// Convenience typedef for a map which key is a string and which
/// value is a vector of elf_symbol.
typedef std::unordered_map<string, elf_symbols>
string_elf_symbols_map_type;
 
/// Convenience typedef for a shared pointer to
/// string_elf_symbols_map_type.
typedef shared_ptr<string_elf_symbols_map_type> string_elf_symbols_map_sptr;
 
/// Abstraction of an elf symbol.
///
/// This is useful when a given corpus has been read from an ELF file.
/// In that case, a given decl might be associated to its underlying
/// ELF symbol, if that decl is publicly exported in the ELF file.  In
/// that case, comparing decls might involve comparing their
/// underlying symbols as well.
class elf_symbol
{
public:
  /// The type of a symbol.
  enum type
  {
    NOTYPE_TYPE = 0,
    OBJECT_TYPE,
    FUNC_TYPE,
    SECTION_TYPE,
    FILE_TYPE,
    COMMON_TYPE,
    TLS_TYPE,
    GNU_IFUNC_TYPE
  };
 
  /// The binding of a symbol.
  enum binding
  {
    LOCAL_BINDING = 0,
    GLOBAL_BINDING,
    WEAK_BINDING,
    GNU_UNIQUE_BINDING
  };
 
  /// The visibility of the symbol.
  enum visibility
  {
    DEFAULT_VISIBILITY,
    PROTECTED_VISIBILITY,
    HIDDEN_VISIBILITY,
    INTERNAL_VISIBILITY,
  };
 
  /// Inject the elf_symbol::version here.
  class version;
 
private:
  struct priv;
  std::unique_ptr<priv> priv_;
 
  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 = false,
         const abg_compat::optional<uint32_t>&  crc = {},
         const abg_compat::optional<std::string>&   ns = {},
         bool       is_suppressed = false);
 
  elf_symbol(const elf_symbol&);
 
  elf_symbol&
  operator=(const elf_symbol& s);
 
public:
 
  static elf_symbol_sptr
  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 = false,
     const abg_compat::optional<uint32_t>&      crc = {},
     const abg_compat::optional<std::string>&   ns = {},
     bool                       is_suppressed = false);
 
  const environment&
  get_environment() const;
 
  size_t
  get_index() const;
 
  void
  set_index(size_t);
 
  const string&
  get_name() const;
 
  void
  set_name(const string& n);
 
  type
  get_type() const;
 
  void
  set_type(type t);
 
  size_t
  get_size() const;
 
  void
  set_size(size_t);
 
  binding
  get_binding() const;
 
  void
  set_binding(binding b);
 
  version&
  get_version() const;
 
  void
  set_version(const version& v);
 
  void
  set_visibility(visibility v);
 
  visibility
  get_visibility() const;
 
  bool
  is_defined() const;
 
  void
  is_defined(bool d);
 
  bool
  is_public() const;
 
  bool
  is_function() const;
 
  bool
  is_variable() const;
 
  bool
  is_in_ksymtab() const;
 
  void
  set_is_in_ksymtab(bool is_in_ksymtab);
 
  const abg_compat::optional<uint32_t>&
  get_crc() const;
 
  void
  set_crc(const abg_compat::optional<uint32_t>& crc);
 
  const abg_compat::optional<std::string>&
  get_namespace() const;
 
  void
  set_namespace(const abg_compat::optional<std::string>& ns);
 
  bool
  is_suppressed() const;
 
  void
  set_is_suppressed(bool is_suppressed);
 
  const elf_symbol_sptr
  get_main_symbol() const;
 
  elf_symbol_sptr
  get_main_symbol();
 
  bool
  is_main_symbol() const;
 
  elf_symbol_sptr
  update_main_symbol(const std::string&);
 
  elf_symbol_sptr
  get_next_alias() const;
 
  bool
  has_aliases() const;
 
  int
  get_number_of_aliases() const;
 
  void
  add_alias(const elf_symbol_sptr&);
 
  bool
  is_common_symbol() const;
 
  bool
  has_other_common_instances() const;
 
  elf_symbol_sptr
  get_next_common_instance() const;
 
  void
  add_common_instance(const elf_symbol_sptr&);
 
  const string&
  get_id_string() const;
 
  elf_symbol_sptr
  get_alias_from_name(const string& name) const;
 
  elf_symbol_sptr
  get_alias_which_equals(const elf_symbol& other) const;
 
  elf_symbol_sptr
  get_alias_with_default_symbol_version() const;
 
  string
  get_aliases_id_string(const string_elf_symbols_map_type& symtab,
            bool include_symbol_itself = true) const;
 
  string
  get_aliases_id_string(bool include_symbol_itself = true) const;
 
  static bool
  get_name_and_version_from_id(const string& id,
                   string& name,
                   string& ver);
 
  bool
  operator==(const elf_symbol&) const;
 
  bool
  does_alias(const elf_symbol&) const;
}; // end class elf_symbol.
 
std::ostream&
operator<<(std::ostream& o, elf_symbol::type t);
 
std::ostream&
operator<<(std::ostream& o, elf_symbol::binding t);
 
std::ostream&
operator<<(std::ostream& o, elf_symbol::visibility t);
 
bool
string_to_elf_symbol_type(const string&, elf_symbol::type&);
 
bool
string_to_elf_symbol_binding(const string&, elf_symbol::binding&);
 
bool
string_to_elf_symbol_visibility(const string&, elf_symbol::visibility&);
 
bool
elf_symbol_is_function(elf_symbol::type);
 
bool
elf_symbol_is_variable(elf_symbol::type);
 
bool
operator==(const elf_symbol_sptr& lhs, const elf_symbol_sptr& rhs);
 
bool
operator!=(const elf_symbol_sptr& lhs, const elf_symbol_sptr& rhs);
 
bool
elf_symbols_alias(const elf_symbol& s1, const elf_symbol& s2);
 
void
compute_aliases_for_elf_symbol(const elf_symbol& symbol,
                   const string_elf_symbols_map_type& symtab,
                   vector<elf_symbol_sptr>& alias_set);
 
/// The abstraction of the version of an ELF symbol.
class elf_symbol::version
{
  struct priv;
  std::unique_ptr<priv> priv_;
 
public:
  version();
 
  version(const string& v,
      bool is_default);
 
  version(const version& v);
 
  ~version();
 
  operator const string&() const;
 
  const string&
  str() const;
 
  void
  str(const string& s);
 
  bool
  is_default() const;
 
  void
  is_default(bool f);
 
  bool
  is_empty() const;
 
  bool
  operator==(const version& o) const;
 
  bool
  operator!=(const version& o) const;
 
  version&
  operator=(const version& o);
};// end class elf_symbol::version
 
class context_rel;
/// A convenience typedef for shared pointers to @ref context_rel
typedef shared_ptr<context_rel> context_rel_sptr;
 
/// The abstraction of the relationship between an entity and its
/// containing scope (its context).  That relationship can carry
/// properties like access rights (if the parent is a class_decl),
/// etc.
///
/// But importantly, this relationship carries a pointer to the
/// actualy parent.
class context_rel
{
protected:
  scope_decl*       scope_;
  enum access_specifier access_;
  bool          is_static_;
 
public:
  context_rel()
    : scope_(0),
      access_(no_access),
      is_static_(false)
  {}
 
  context_rel(scope_decl* s)
    : scope_(s),
      access_(no_access),
      is_static_(false)
  {}
 
  context_rel(scope_decl* s,
          access_specifier a,
          bool f)
    : scope_(s),
      access_(a),
      is_static_(f)
  {}
 
  scope_decl*
  get_scope() const
  {return scope_;}
 
  access_specifier
  get_access_specifier() const
  {return access_;}
 
  void
  set_access_specifier(access_specifier a)
  {access_ = a;}
 
  bool
  get_is_static() const
  {return is_static_;}
 
  void
  set_is_static(bool s)
  {is_static_ = s;}
 
  void
  set_scope(scope_decl* s)
  {scope_ = s;}
 
  bool
  operator==(const context_rel& o)const
  {
    return (access_ == o.access_
        && is_static_ == o.is_static_);
  }
 
  /// Inequality operator.
  ///
  /// @param o the other instance of @ref context_rel to compare the
  /// current instance against.
  ///
  /// @return true iff the current instance of @ref context_rel is
  /// different from @p o.
  bool
  operator!=(const context_rel& o) const
  {return !operator==(o);}
 
  virtual ~context_rel();
};// end class context_rel
 
/// A bitfield that gives callers of abigail::ir::equals() some
/// insight about how different two internal representation artifacts
/// are.
enum change_kind
{
  NO_CHANGE_KIND = 0,
 
  /// This means that a given IR artifact has a local type change.
  LOCAL_TYPE_CHANGE_KIND = 1 << 0,
 
  /// This means that a given IR artifact has a local non-type change.
  /// That is a change that is carried by the artifact itself, not by
  /// its type.
  LOCAL_NON_TYPE_CHANGE_KIND = 1 << 1,
 
  /// Testing (anding) against this mask means that a given IR artifact has
  /// local differences, with respect to the other artifact it was compared
  /// against. A local change is a change that is carried by the artifact
  /// itself (or its type), rather than by one off its sub-types.
  ALL_LOCAL_CHANGES_MASK = LOCAL_TYPE_CHANGE_KIND | LOCAL_NON_TYPE_CHANGE_KIND,
 
  /// This means that a given IR artifact has changes in some of its
  /// sub-types, with respect to the other artifact it was compared
  /// against.
  SUBTYPE_CHANGE_KIND = 1 << 2,
};// end enum change_kind
 
change_kind
operator|(change_kind, change_kind);
 
change_kind
operator&(change_kind, change_kind);
 
change_kind&
operator|=(change_kind&, change_kind);
 
change_kind&
operator&=(change_kind&, change_kind);
 
bool
maybe_compare_as_member_decls(const decl_base& l,
                  const decl_base& r,
                  change_kind* k);
 
bool
equals(const decl_base&, const decl_base&, change_kind*);
 
/// The base class of both types and declarations.
class type_or_decl_base : public ir_traversable_base
{
  struct priv;
  mutable std::unique_ptr<priv> priv_;
 
  type_or_decl_base();
  type_or_decl_base(const type_or_decl_base&);
 
protected:
 
  /// This is a bitmap type which instance is meant to contain the
  /// runtime type of a given ABI artifact.  Bits of the identifiers
  /// of the type of a given artifact as well as the types it inherits
  /// from are to be set to 1.
  enum type_or_decl_kind
  {
    ABSTRACT_TYPE_OR_DECL,
    ABSTRACT_DECL_BASE = 1,
    ABSTRACT_SCOPE_DECL = 1 << 1,
    GLOBAL_SCOPE_DECL = 1 << 2,
    NAMESPACE_DECL = 1 << 3,
    VAR_DECL = 1 << 4,
    FUNCTION_DECL = 1 << 5,
    FUNCTION_PARAMETER_DECL = 1 << 6,
    METHOD_DECL = 1 << 7,
    TEMPLATE_DECL = 1 << 8,
    ABSTRACT_TYPE_BASE = 1 << 9,
    ABSTRACT_SCOPE_TYPE_DECL = 1 << 10,
    BASIC_TYPE = 1 << 11,
    QUALIFIED_TYPE = 1 << 12,
    POINTER_TYPE = 1 << 13,
    REFERENCE_TYPE = 1 << 14,
    ARRAY_TYPE = 1 << 15,
    ENUM_TYPE = 1 << 16,
    TYPEDEF_TYPE = 1 << 17,
    CLASS_TYPE = 1 << 18,
    UNION_TYPE = 1 << 19,
    FUNCTION_TYPE = 1 << 20,
    METHOD_TYPE = 1 << 21,
  }; // end enum type_or_decl_kind
 
  enum type_or_decl_kind
  kind() const;
 
  void
  kind(enum type_or_decl_kind);
 
  const void*
  runtime_type_instance() const;
 
  void*
  runtime_type_instance();
 
  void
  runtime_type_instance(void*);
 
  const void*
  type_or_decl_base_pointer() const;
 
  void*
  type_or_decl_base_pointer();
 
  bool hashing_started() const;
 
  void hashing_started(bool) const;
 
  type_or_decl_base&
  operator=(const type_or_decl_base&);
 
public:
 
  type_or_decl_base(const environment&,
            enum type_or_decl_kind k = ABSTRACT_TYPE_OR_DECL);
 
  virtual ~type_or_decl_base();
 
  bool
  get_is_artificial() const;
 
  void
  set_is_artificial(bool);
 
  const environment&
  get_environment() const;
 
  void
  set_artificial_location(const location &);
 
  location&
  get_artificial_location() const;
 
  bool
  has_artificial_location() const;
 
  const corpus*
  get_corpus() const;
 
  corpus*
  get_corpus();
 
  void
  set_translation_unit(translation_unit*);
 
  const translation_unit*
  get_translation_unit() const;
 
  translation_unit*
  get_translation_unit();
 
  virtual bool
  traverse(ir_node_visitor&);
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const = 0;
 
  friend type_or_decl_base::type_or_decl_kind
  operator|(type_or_decl_base::type_or_decl_kind,
        type_or_decl_base::type_or_decl_kind);
 
  friend type_or_decl_base::type_or_decl_kind&
  operator|=(type_or_decl_base::type_or_decl_kind&,
         type_or_decl_base::type_or_decl_kind);
 
  friend type_or_decl_base::type_or_decl_kind
  operator&(type_or_decl_base::type_or_decl_kind,
        type_or_decl_base::type_or_decl_kind);
 
  friend type_or_decl_base::type_or_decl_kind&
  operator&=(type_or_decl_base::type_or_decl_kind&,
         type_or_decl_base::type_or_decl_kind);
 
  friend class_decl*
  is_class_type(const type_or_decl_base*);
 
  friend pointer_type_def*
  is_pointer_type(type_or_decl_base*);
 
  friend type_base*
  is_type(const type_or_decl_base*);
 
  friend decl_base*
  is_decl(const type_or_decl_base* d);
}; // end class type_or_decl_base
 
type_or_decl_base::type_or_decl_kind
operator|(type_or_decl_base::type_or_decl_kind,
      type_or_decl_base::type_or_decl_kind);
 
type_or_decl_base::type_or_decl_kind&
operator|=(type_or_decl_base::type_or_decl_kind&,
       type_or_decl_base::type_or_decl_kind);
 
type_or_decl_base::type_or_decl_kind
operator&(type_or_decl_base::type_or_decl_kind,
      type_or_decl_base::type_or_decl_kind);
 
type_or_decl_base::type_or_decl_kind&
operator&=(type_or_decl_base::type_or_decl_kind&,
       type_or_decl_base::type_or_decl_kind);
 
bool
operator==(const type_or_decl_base&, const type_or_decl_base&);
 
bool
operator==(const type_or_decl_base_sptr&, const type_or_decl_base_sptr&);
 
bool
operator!=(const type_or_decl_base_sptr&, const type_or_decl_base_sptr&);
 
/// The base type of all declarations.
class decl_base : public virtual type_or_decl_base
{
  // Forbidden
  decl_base();
 
  struct priv;
 
protected:
 
  const interned_string&
  peek_qualified_name() const;
 
  void
  clear_qualified_name();
 
  void
  set_qualified_name(const interned_string&) const;
 
  const interned_string&
  peek_temporary_qualified_name() const;
 
  void
  set_temporary_qualified_name(const interned_string&) const;
 
public:
  // This is public because some internals of the library need to
  // update it.  But it's opaque to client code anyway, so no big
  // deal.  Also, it's not handled by a shared_ptr because accessing
  // the data members of the priv struct for this decl_base shows up
  // on performance profiles when dealing with big binaries with a lot
  // of types; dereferencing the shared_ptr involves locking of some
  // sort and that is slower than just dereferencing a pointer likere
  // here.  There are other types for which the priv pointer is
  // managed using shared_ptr just fine, because those didn't show up
  // during our performance profiling.
  priv* priv_;
 
  /// Facility to hash instances of decl_base.
  struct hash;
 
  /// ELF visibility
  enum visibility
  {
    VISIBILITY_NONE,
    VISIBILITY_DEFAULT,
    VISIBILITY_PROTECTED,
    VISIBILITY_HIDDEN,
    VISIBILITY_INTERNAL
  };
 
  /// ELF binding
  enum binding
  {
    BINDING_NONE,
    BINDING_LOCAL,
    BINDING_GLOBAL,
    BINDING_WEAK
  };
 
  virtual void
  set_scope(scope_decl*);
 
protected:
  const context_rel*
  get_context_rel() const;
 
  context_rel*
  get_context_rel();
 
  void
  set_context_rel(context_rel *c);
  decl_base(const decl_base&);
 
public:
  decl_base(const environment& e,
        const string& name,
        const location& locus,
        const string& mangled_name = "",
        visibility vis = VISIBILITY_DEFAULT);
 
  decl_base(const environment& e,
        const interned_string& name,
        const location& locus,
        const interned_string& mangled_name = interned_string(),
        visibility vis = VISIBILITY_DEFAULT);
 
  decl_base(const environment&, const location&);
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator!=(const decl_base&) const;
 
  virtual bool
  traverse(ir_node_visitor& v);
 
  virtual ~decl_base();
 
  virtual size_t
  get_hash() const;
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const;
 
  virtual void
  get_qualified_name(interned_string& qualified_name,
             bool internal = false) const;
 
  virtual const interned_string&
  get_qualified_name(bool internal = false) const;
 
  virtual const interned_string&
  get_scoped_name() const;
 
  bool
  get_is_in_public_symbol_table() const;
 
  void
  set_is_in_public_symbol_table(bool);
 
  const location&
  get_location() const;
 
  void
  set_location(const location& l);
 
  const interned_string&
  get_name() const;
 
  const interned_string&
  get_qualified_parent_name() const;
 
  void
  set_name(const string& n);
 
  bool
  get_is_anonymous() const;
 
  void
  set_is_anonymous(bool);
 
  bool
  get_has_anonymous_parent() const;
 
  bool
  get_is_anonymous_or_has_anonymous_parent() const;
 
  typedef_decl_sptr
  get_naming_typedef() const;
 
  void
  set_naming_typedef(const typedef_decl_sptr&);
 
  const interned_string&
  get_linkage_name() const;
 
  virtual void
  set_linkage_name(const string& m);
 
  scope_decl*
  get_scope() const;
 
  visibility
  get_visibility() const;
 
  void
  set_visibility(visibility v);
 
  const decl_base_sptr
  get_earlier_declaration() const;
 
  void
  set_earlier_declaration(const decl_base_sptr&);
 
  const decl_base_sptr
  get_definition_of_declaration() const;
 
  void
  set_definition_of_declaration(const decl_base_sptr&);
 
  const decl_base*
  get_naked_definition_of_declaration() const;
 
  bool
  get_is_declaration_only() const;
 
  void
  set_is_declaration_only(bool f);
 
  friend bool
  equals(const decl_base&, const decl_base&, change_kind*);
 
  friend bool
  equals(const var_decl&, const var_decl&, change_kind*);
 
  friend bool
  var_equals_modulo_types(const var_decl&, const var_decl&, change_kind*);
 
  friend bool
  maybe_compare_as_member_decls(const decl_base& l,
                const decl_base& r,
                change_kind* k);
 
  friend decl_base_sptr
  add_decl_to_scope(decl_base_sptr decl, scope_decl* scpe);
 
  friend void
  remove_decl_from_scope(decl_base_sptr);
 
  friend decl_base_sptr
  insert_decl_into_scope(decl_base_sptr,
             vector<shared_ptr<decl_base> >::iterator,
             scope_decl*);
 
  friend enum access_specifier
  get_member_access_specifier(const decl_base& d);
 
  friend enum access_specifier
  get_member_access_specifier(const decl_base_sptr& d);
 
  friend void
  set_member_access_specifier(decl_base& d,
                  access_specifier a);
 
  friend bool
  get_member_is_static(const decl_base& d);
 
  friend bool
  get_member_is_static(const decl_base_sptr& d);
 
  friend void
  set_member_is_static(const decl_base_sptr& d, bool s);
 
  friend void
  set_member_is_static(decl_base& d, bool s);
 
  friend bool
  get_member_function_is_virtual(const function_decl& f);
 
  friend void
  set_member_function_is_virtual(function_decl&, bool);
 
  friend class class_or_union;
  friend class class_decl;
  friend class scope_decl;
};// end class decl_base
 
bool
operator==(const decl_base_sptr&, const decl_base_sptr&);
 
bool
operator!=(const decl_base_sptr&, const decl_base_sptr&);
 
bool
operator==(const type_base_sptr&, const type_base_sptr&);
 
bool
operator!=(const type_base_sptr&, const type_base_sptr&);
 
std::ostream&
operator<<(std::ostream&, decl_base::visibility);
 
std::ostream&
operator<<(std::ostream&, decl_base::binding);
 
bool
equals(const scope_decl&, const scope_decl&, change_kind*);
 
/// A declaration that introduces a scope.
class scope_decl : public virtual decl_base
{
  struct priv;
  std::unique_ptr<priv> priv_;
 
public:
 
  /// Convenience typedef for a vector of @ref decl_base_sptr.
  typedef std::vector<decl_base_sptr >  declarations;
  /// Convenience typedef for a vector of @ref function_type_sptr.
  typedef std::vector<function_type_sptr >  function_types;
  /// Convenience typedef for a vector of @ref scope_decl_sptr.
  typedef std::vector<scope_decl_sptr>  scopes;
 
  scope_decl();
 
protected:
  virtual decl_base_sptr
  add_member_decl(const decl_base_sptr& member);
 
  decl_base_sptr
  insert_member_decl(decl_base_sptr member, declarations::iterator before);
 
  virtual void
  remove_member_decl(decl_base_sptr member);
 
public:
  struct hash;
 
  scope_decl(const environment& env,
         const string& name, const location& locus,
         visibility vis = VISIBILITY_DEFAULT);
 
  scope_decl(const environment& env, location& l);
 
  virtual size_t
  get_hash() const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  const canonical_type_sptr_set_type&
  get_canonical_types() const;
 
  canonical_type_sptr_set_type&
  get_canonical_types();
 
  const type_base_sptrs_type&
  get_sorted_canonical_types() const;
 
  const declarations&
  get_member_decls() const;
 
  declarations&
  get_member_decls();
 
  const declarations&
  get_sorted_member_decls() const;
 
  virtual size_t
  get_num_anonymous_member_classes() const;
 
  virtual size_t
  get_num_anonymous_member_unions() const;
 
  virtual size_t
  get_num_anonymous_member_enums() const;
 
  scopes&
  get_member_scopes();
 
  const scopes&
  get_member_scopes() const;
 
  bool
  is_empty() const;
 
  bool
  find_iterator_for_member(const decl_base*, declarations::iterator&);
 
  bool
  find_iterator_for_member(const decl_base_sptr, declarations::iterator&);
 
  void
  insert_member_type(type_base_sptr t,
             declarations::iterator before);
 
  void
  add_member_type(type_base_sptr t);
 
  type_base_sptr
  add_member_type(type_base_sptr t, access_specifier a);
 
  void
  remove_member_type(type_base_sptr t);
 
  const type_base_sptrs_type&
  get_member_types() const;
 
  const type_base_sptrs_type&
  get_sorted_member_types() const;
 
  type_base_sptr
  find_member_type(const string& name) const;
 
  virtual bool
  traverse(ir_node_visitor&);
 
  virtual ~scope_decl();
 
  friend decl_base_sptr
  add_decl_to_scope(decl_base_sptr decl, scope_decl* scope);
 
  friend decl_base_sptr
  insert_decl_into_scope(decl_base_sptr decl,
             scope_decl::declarations::iterator before,
             scope_decl* scope);
 
  friend void
  remove_decl_from_scope(decl_base_sptr decl);
};//end class scope_decl
 
bool
operator==(const scope_decl_sptr&, const scope_decl_sptr&);
 
bool
operator!=(const scope_decl_sptr&, const scope_decl_sptr&);
 
/// Hasher for the @ref scope_decl type.
struct scope_decl::hash
{
  size_t
  operator()(const scope_decl& d) const;
 
  size_t
  operator()(const scope_decl* d) const;
};
 
/// This abstracts the global scope of a given translation unit.
///
/// Only one instance of this class must be present in a given
/// translation_unit.  That instance is implicitely created the first
/// time translatin_unit::get_global_scope is invoked.
class global_scope : public scope_decl
{
  translation_unit* translation_unit_;
 
  global_scope(translation_unit *tu);
 
public:
 
  friend class translation_unit;
 
  translation_unit*
  get_translation_unit() const
  {return translation_unit_;}
 
  virtual ~global_scope();
};
 
bool
equals(const type_base&, const type_base&, change_kind*);
 
/// An abstraction helper for type declarations
class type_base : public virtual type_or_decl_base
{
  struct priv;
 
public:
  // This priv pointer is not handled by a shared_ptr because
  // accessing the data members of the priv struct for this type_base
  // shows up on performance profiles when dealing with big binaries
  // with a lot of types; dereferencing the shared_ptr involves
  // locking of some sort and that is slower than just dereferencing a
  // pointer likere here.  There are other types for which the priv
  // pointer is managed using shared_ptr just fine, because those
  // didn't show up during our performance profiling.
  priv* priv_;
 
private:
  // Forbid this.
  type_base();
 
  static type_base_sptr
  get_canonical_type_for(type_base_sptr);
 
protected:
  virtual void
  on_canonical_type_set();
 
public:
 
  /// A hasher for type_base types.
  struct hash;
 
  /// A hasher for types.  It gets the dynamic type of the current
  /// instance of type and hashes it accordingly.  Note that the hashing
  /// function of this hasher must be updated each time a new kind of
  /// type is added to the IR.
  struct dynamic_hash;
 
  /// A hasher for shared_ptr<type_base> that will hash it based on the
  /// runtime type of the type pointed to.
  struct shared_ptr_hash;
 
  type_base(const environment& e, size_t s, size_t a);
 
  friend type_base_sptr canonicalize(type_base_sptr);
 
  type_base_sptr
  get_canonical_type() const;
 
  type_base*
  get_naked_canonical_type() const;
 
  const interned_string&
  get_cached_pretty_representation(bool internal = false) const;
 
  virtual bool
  operator==(const type_base&) const;
 
  virtual bool
  operator!=(const type_base&) const;
 
  virtual bool
  traverse(ir_node_visitor&);
 
  virtual ~type_base();
 
  virtual void
  set_size_in_bits(size_t);
 
  virtual size_t
  get_size_in_bits() const;
 
  virtual void
  set_alignment_in_bits(size_t);
 
  virtual size_t
  get_alignment_in_bits() const;
};//end class type_base
 
/// Hash functor for instances of @ref type_base.
struct type_base::hash
{
  size_t
  operator()(const type_base& t) const;
 
  size_t
  operator()(const type_base* t) const;
 
  size_t
  operator()(const type_base_sptr t) const;
}; // end struct type_base::hash
 
/// A predicate for deep equality of instances of
/// type_base*
struct type_ptr_equal
{
  bool
  operator()(const type_base* l, const type_base* r) const
  {
    if (!!l != !!r)
      return false;
 
    if (l == r)
      return true;
 
    if (l)
      return *l == *r;
 
    return true;
  }
};
 
/// A predicate for deep equality of instances of
/// shared_ptr<type_base>
struct type_shared_ptr_equal
{
  bool
  operator()(const type_base_sptr l, const type_base_sptr r) const
  {
    if (!!l != !!r)
      return false;
 
    if (l.get() == r.get())
      return true;
 
    if (l)
      return *l == *r;
 
    return true;
  }
};
 
bool
equals(const type_decl&, const type_decl&, change_kind*);
 
/// A basic type declaration that introduces no scope.
class type_decl : public virtual decl_base, public virtual type_base
{
  // Forbidden.
  type_decl();
 
public:
 
  /// Facility to hash instance of type_decl
  struct hash;
 
  type_decl(const environment&  env,
        const string&   name,
        size_t      size_in_bits,
        size_t      alignment_in_bits,
        const location& locus,
        const string&   mangled_name = "",
        visibility      vis = VISIBILITY_DEFAULT);
 
  virtual bool
  operator==(const type_base&) const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const type_decl&) const;
 
  virtual bool
  operator!=(const type_base&)const;
 
  virtual bool
  operator!=(const decl_base&)const;
 
  virtual bool
  operator!=(const type_decl&)const;
 
  virtual void
  get_qualified_name(interned_string& qualified_name,
             bool internal = false) const;
 
  virtual const interned_string&
  get_qualified_name(bool internal = false) const;
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const;
 
  virtual bool
  traverse(ir_node_visitor&);
 
  virtual ~type_decl();
};// end class type_decl.
 
bool
equals(const scope_type_decl&, const scope_type_decl&, change_kind*);
 
bool
operator==(const type_decl_sptr&, const type_decl_sptr&);
 
bool
operator!=(const type_decl_sptr&, const type_decl_sptr&);
 
/// A type that introduces a scope.
class scope_type_decl : public scope_decl, public virtual type_base
{
  scope_type_decl();
 
public:
 
  /// Hasher for instances of scope_type_decl
  struct hash;
 
  scope_type_decl(const environment& env, const string& name,
          size_t size_in_bits, size_t alignment_in_bits,
          const location& locus, visibility vis = VISIBILITY_DEFAULT);
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const type_base&) const;
 
  virtual bool
  traverse(ir_node_visitor&);
 
  virtual ~scope_type_decl();
};
 
/// The abstraction of a namespace declaration
class namespace_decl : public scope_decl
{
public:
 
  namespace_decl(const environment& env, const string& name,
         const location& locus, visibility vis = VISIBILITY_DEFAULT);
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  traverse(ir_node_visitor&);
 
  virtual ~namespace_decl();
 
  bool is_empty_or_has_empty_sub_namespaces() const;
};// end class namespace_decl
 
/// A convenience typedef for vectors of @ref namespace_decl_sptr
typedef vector<namespace_decl_sptr> namespaces_type;
 
bool
equals(const qualified_type_def&, const qualified_type_def&, change_kind*);
 
/// The abstraction of a qualified type.
class qualified_type_def : public virtual type_base, public virtual decl_base
{
  class priv;
  std::unique_ptr<priv> priv_;
 
  // Forbidden.
  qualified_type_def();
 
protected:
  string build_name(bool, bool internal = false) const;
  virtual void on_canonical_type_set();
 
public:
 
  /// A Hasher for instances of qualified_type_def
  struct hash;
 
  /// Bit field values representing the cv qualifiers of the
  /// underlying type.
  enum CV
  {
    CV_NONE = 0,
    CV_CONST = 1,
    CV_VOLATILE = 1 << 1,
    CV_RESTRICT = 1 << 2
  };
 
  qualified_type_def(type_base_sptr type, CV quals, const location& locus);
 
  qualified_type_def(const environment& env, CV quals, const location& locus);
 
  virtual size_t
  get_size_in_bits() const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const type_base&) const;
 
  virtual bool
  operator==(const qualified_type_def&) const;
 
  CV
  get_cv_quals() const;
 
  void
  set_cv_quals(CV cv_quals);
 
  string
  get_cv_quals_string_prefix() const;
 
  type_base_sptr
  get_underlying_type() const;
 
  void
  set_underlying_type(const type_base_sptr&);
 
  virtual void
  get_qualified_name(interned_string& qualified_name,
             bool internal = false) const;
 
  virtual const interned_string&
  get_qualified_name(bool internal = false) const;
 
  virtual bool
  traverse(ir_node_visitor& v);
 
  virtual ~qualified_type_def();
}; // end class qualified_type_def.
 
bool
operator==(const qualified_type_def_sptr&, const qualified_type_def_sptr&);
 
bool
operator!=(const qualified_type_def_sptr&, const qualified_type_def_sptr&);
 
qualified_type_def::CV
operator|(qualified_type_def::CV, qualified_type_def::CV);
 
qualified_type_def::CV&
operator|=(qualified_type_def::CV&, qualified_type_def::CV);
 
qualified_type_def::CV&
operator&=(qualified_type_def::CV&, qualified_type_def::CV);
 
qualified_type_def::CV
operator&(qualified_type_def::CV, qualified_type_def::CV);
 
qualified_type_def::CV
operator~(qualified_type_def::CV);
 
std::ostream&
operator<<(std::ostream&, qualified_type_def::CV);
 
string
get_string_representation_of_cv_quals(const qualified_type_def::CV);
 
interned_string
get_name_of_qualified_type(const type_base_sptr& underlying_type,
               qualified_type_def::CV quals,
               bool qualified = true, bool internal = false);
 
qualified_type_def_sptr
lookup_qualified_type(const type_base_sptr&,
              qualified_type_def::CV,
              const translation_unit&);
bool
equals(const pointer_type_def&, const pointer_type_def&, change_kind*);
 
/// The abstraction of a pointer type.
class pointer_type_def : public virtual type_base, public virtual decl_base
{
  struct priv;
  std::unique_ptr<priv> priv_;
 
  // Forbidden.
  pointer_type_def();
 
protected:
  virtual void on_canonical_type_set();
 
public:
 
  /// A hasher for instances of pointer_type_def
  struct hash;
 
  pointer_type_def(const type_base_sptr& pointed_to_type, size_t size_in_bits,
           size_t alignment_in_bits, const location& locus);
 
  pointer_type_def(const environment& env, size_t size_in_bits,
           size_t alignment_in_bits, const location& locus);
 
  void
  set_pointed_to_type(const type_base_sptr&);
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const type_base&) const;
 
  bool
  operator==(const pointer_type_def&) const;
 
  const type_base_sptr
  get_pointed_to_type() const;
 
  type_base*
  get_naked_pointed_to_type() const;
 
  virtual void
  get_qualified_name(interned_string&, bool internal = false) const;
 
  virtual const interned_string&
  get_qualified_name(bool internal = false) const;
 
  virtual bool
  traverse(ir_node_visitor& v);
 
  virtual ~pointer_type_def();
}; // end class pointer_type_def
 
bool
operator==(const pointer_type_def_sptr&, const pointer_type_def_sptr&);
 
bool
operator!=(const pointer_type_def_sptr&, const pointer_type_def_sptr&);
 
bool
equals(const reference_type_def&, const reference_type_def&, change_kind*);
 
 
/// Abstracts a reference type.
class reference_type_def : public virtual type_base, public virtual decl_base
{
  type_base_wptr    pointed_to_type_;
  bool          is_lvalue_;
 
  // Forbidden.
  reference_type_def();
 
protected:
  virtual void on_canonical_type_set();
 
public:
 
  /// Hasher for intances of reference_type_def.
  struct hash;
 
  reference_type_def(const type_base_sptr pointed_to_type,
             bool lvalue, size_t size_in_bits,
             size_t alignment_in_bits, const location& locus);
 
  reference_type_def(const environment& env, bool lvalue, size_t size_in_bits,
             size_t alignment_in_bits, const location& locus);
 
  void
  set_pointed_to_type(type_base_sptr& pointed_to_type);
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const type_base&) const;
 
  bool
  operator==(const reference_type_def&) const;
 
  type_base_sptr
  get_pointed_to_type() const;
 
  bool
  is_lvalue() const;
 
  virtual void
  get_qualified_name(interned_string& qualified_name,
             bool internal = false) const;
 
  virtual const interned_string&
  get_qualified_name(bool internal = false) const;
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const;
 
  virtual bool
  traverse(ir_node_visitor& v);
 
  virtual ~reference_type_def();
}; // end class reference_type_def
 
bool
operator==(const reference_type_def_sptr&, const reference_type_def_sptr&);
 
bool
operator!=(const reference_type_def_sptr&, const reference_type_def_sptr&);
 
bool
equals(const array_type_def&, const array_type_def&, change_kind*);
 
/// The abstraction of an array type.
class array_type_def : public virtual type_base, public virtual decl_base
{
  struct priv;
  std::unique_ptr<priv> priv_;
 
  // Forbidden.
  array_type_def();
 
  void update_size();
 
public:
 
  /// Hasher for intances of array_type_def.
  struct hash;
 
  class subrange_type;
 
  /// Convenience typedef for a shared pointer on a @ref
  /// function_decl::subrange
  typedef shared_ptr<subrange_type> subrange_sptr;
 
  /// Convenience typedef for a vector of @ref subrange_sptr
  typedef std::vector<subrange_sptr> subranges_type;
 
  /// Abstraction for an array range type, like in Ada, or just for an
  /// array dimension like in C or C++.
  class subrange_type : public virtual type_base,  public virtual decl_base
  {
    struct priv;
    std::unique_ptr<priv> priv_;
 
    // Forbidden.
    subrange_type();
  public:
 
    virtual ~subrange_type();
    /// This class is to hold the value of the bound of a subrange.
    /// The value can be either signed or unsigned, at least when it
    /// comes from DWARF.  The class keeps the sign information, but
    /// allows users to access the value as signed or unsigned as they
    /// see fit.
    class bound_value
    {
    public:
      enum signedness
      {
    UNSIGNED_SIGNEDNESS,
    SIGNED_SIGNEDNESS
      };
 
    private:
      signedness s_;
 
    public:
      union
      {
    uint64_t unsigned_;
    int64_t signed_;
      } v_;
      bound_value();
      bound_value(uint64_t);
      bound_value(int64_t);
      enum signedness get_signedness() const;
      void set_signedness(enum signedness s);
      int64_t get_signed_value() const;
      uint64_t get_unsigned_value();
      void set_unsigned(uint64_t v);
      void set_signed(int64_t v);
      bool operator==(const bound_value&) const;
    }; //end class bound_value
 
    /// Hasher for an instance of array::subrange
    struct hash;
 
    subrange_type(const environment&    env,
          const string& name,
          bound_value       lower_bound,
          bound_value       upper_bound,
          const type_base_sptr& underlying_type,
          const location&   loc,
          translation_unit::language l = translation_unit::LANG_C11);
 
    subrange_type(const environment& env,
          const string& name,
          bound_value lower_bound,
          bound_value upper_bound,
          const location& loc,
          translation_unit::language l = translation_unit::LANG_C11);
 
    subrange_type(const environment& env,
          const string& name,
          bound_value upper_bound,
          const location& loc,
          translation_unit::language l = translation_unit::LANG_C11);
 
    type_base_sptr
    get_underlying_type() const;
 
    void
    set_underlying_type(const type_base_sptr &);
 
    int64_t
    get_upper_bound() const;
 
    int64_t
    get_lower_bound() const;
 
    void
    set_upper_bound(int64_t ub);
 
    void
    set_lower_bound(int64_t lb);
 
    uint64_t
    get_length() const;
 
    bool
    is_infinite() const;
 
    void
    is_infinite(bool);
 
    translation_unit::language
    get_language() const;
 
    virtual bool
    operator==(const decl_base&) const;
 
    virtual bool
    operator==(const type_base&) const;
 
    bool
    operator==(const subrange_type& o) const;
 
    bool
    operator!=(const decl_base& o) const;
 
    bool
    operator!=(const type_base& o) const;
 
    bool
    operator!=(const subrange_type& o) const;
 
    string
    as_string() const;
 
    static string
    vector_as_string(const vector<subrange_sptr>&);
 
    virtual string
    get_pretty_representation(bool internal = false,
                  bool qualified_name = true) const;
 
    virtual bool
    traverse(ir_node_visitor&);
  }; // end class subrange_type
 
  array_type_def(const type_base_sptr type,
         const std::vector<subrange_sptr>& subs,
         const location& locus);
 
  array_type_def(const environment& env,
         const std::vector<subrange_sptr>& subs,
         const location& locus);
 
  translation_unit::language
  get_language() const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const type_base&) const;
 
  virtual void
  get_qualified_name(interned_string& qualified_name,
             bool internal = false) const;
 
  virtual const interned_string&
  get_qualified_name(bool internal = false) const;
 
  const type_base_sptr
  get_element_type() const;
 
  void
  set_element_type(const type_base_sptr& element_type);
 
  virtual void
  append_subranges(const std::vector<subrange_sptr>& subs);
 
  virtual int
  get_dimension_count() const;
 
  virtual bool
  is_infinite() const;
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const;
 
  virtual string
  get_subrange_representation() const;
 
  virtual bool
  traverse(ir_node_visitor& v);
 
  const location&
  get_location() const;
 
  const std::vector<subrange_sptr>&
  get_subranges() const;
 
  virtual ~array_type_def();
 
}; // end class array_type_def
 
array_type_def::subrange_type*
is_subrange_type(const type_or_decl_base *type);
 
array_type_def::subrange_sptr
is_subrange_type(const type_or_decl_base_sptr &type);
 
bool
equals(const array_type_def::subrange_type&,
       const array_type_def::subrange_type&,
       change_kind*);
 
bool
equals(const enum_type_decl&, const enum_type_decl&, change_kind*);
 
/// Abstracts a declaration for an enum type.
class enum_type_decl : public virtual type_base, public virtual decl_base
{
  class priv;
  std::unique_ptr<priv> priv_;
 
  // Forbidden
  enum_type_decl();
 
public:
 
  /// A hasher for an enum_type_decl.
  struct hash;
 
  /// Enumerator Datum.
  class enumerator;
 
  /// Convenience typedef for a list of @ref enumerator.
  typedef std::vector<enumerator> enumerators;
 
  /// Constructor of an enum type declaration.
  ///
  /// @param name the name of the enum
  ///
  /// @param locus the locus at which the enum appears in the source
  /// code.
  ///
  /// @param underlying_type the underlying type of the enum
  ///
  /// @param enms a list of enumerators for this enum.
  ///
  /// @param mangled_name the mangled name of the enum type.
  ///
  /// @param vis the visibility of instances of this type.
  enum_type_decl(const string&      name,
         const location&    locus,
         type_base_sptr underlying_type,
         enumerators&       enms,
         const string&      mangled_name = "",
         visibility     vis = VISIBILITY_DEFAULT);
 
  type_base_sptr
  get_underlying_type() const;
 
  const enumerators&
  get_enumerators() const;
 
  enumerators&
  get_enumerators();
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const type_base&) const;
 
  virtual bool
  traverse(ir_node_visitor& v);
 
  virtual ~enum_type_decl();
 
  friend bool
  enum_has_non_name_change(const enum_type_decl& l,
               const enum_type_decl& r,
               change_kind* k);
}; // end class enum_type_decl
 
bool
operator==(const enum_type_decl_sptr& l, const enum_type_decl_sptr& r);
 
bool
operator!=(const enum_type_decl_sptr& l, const enum_type_decl_sptr& r);
 
bool
enum_has_non_name_change(const enum_type_decl& l,
             const enum_type_decl& r,
             change_kind* k);
 
/// The abstraction of an enumerator
class enum_type_decl::enumerator
{
  class priv;
  std::unique_ptr<priv> priv_;
 
public:
 
  enumerator();
 
  ~enumerator();
 
  enumerator(const string& name, int64_t value);
 
  enumerator(const enumerator&);
 
  enumerator&
  operator=(const enumerator&);
 
  bool
  operator==(const enumerator& other) const;
 
  bool
  operator!=(const enumerator& other) const;
 
  const string&
  get_name() const;
 
  const string&
  get_qualified_name(bool internal = false) const;
 
  void
  set_name(const string& n);
 
  int64_t
  get_value() const;
 
  void
  set_value(int64_t v);
 
  enum_type_decl*
  get_enum_type() const;
 
  void
  set_enum_type(enum_type_decl*);
}; // end class enum_type_def::enumerator
 
bool
equals(const typedef_decl&, const typedef_decl&, change_kind*);
 
/// The abstraction of a typedef declaration.
class typedef_decl : public virtual type_base, public virtual decl_base
{
  struct priv;
  std::unique_ptr<priv> priv_;
 
  // Forbidden
  typedef_decl();
 
public:
 
  /// Hasher for the typedef_decl type.
  struct hash;
 
  typedef_decl(const string& name,
           const type_base_sptr underlying_type,
           const location& locus,
           const string& mangled_name = "",
           visibility vis = VISIBILITY_DEFAULT);
 
  typedef_decl(const string& name,
           const environment& env,
           const location& locus,
           const string& mangled_name = "",
           visibility vis = VISIBILITY_DEFAULT);
 
  virtual size_t
  get_size_in_bits() const;
 
  virtual size_t
  get_alignment_in_bits() const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const type_base&) const;
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const;
 
  type_base_sptr
  get_underlying_type() const;
 
  void
  set_underlying_type(const type_base_sptr&);
 
  virtual bool
  traverse(ir_node_visitor&);
 
  virtual ~typedef_decl();
};// end class typedef_decl
 
/// The abstraction for a data member context relationship.  This
/// relates a data member to its parent class.
///
/// The relationship carries properties like the offset of the data
/// member, if applicable.
class dm_context_rel : public context_rel
{
protected:
  struct priv;
  std::unique_ptr<priv> priv_;
 
public:
  dm_context_rel();
 
  dm_context_rel(scope_decl* s,
         bool is_laid_out,
         size_t offset_in_bits,
         access_specifier a,
         bool is_static);
 
  dm_context_rel(scope_decl* s);
 
  bool
  get_is_laid_out() const;
 
  void
  set_is_laid_out(bool f);
 
  size_t
  get_offset_in_bits() const;
 
  void
  set_offset_in_bits(size_t o);
 
  const var_decl*
  get_anonymous_data_member() const;
 
  void
  set_anonymous_data_member(var_decl *);
 
  bool
  operator==(const dm_context_rel& o) const;
 
  bool
  operator!=(const dm_context_rel& o) const;
 
  virtual ~dm_context_rel();
};// end class class_decl::dm_context_rel
 
bool
equals(const var_decl&, const var_decl&, change_kind*);
 
bool
var_equals_modulo_types(const var_decl&, const var_decl&, change_kind*);
 
bool
equals_modulo_cv_qualifier(const array_type_def*, const array_type_def*);
 
/// Abstracts a variable declaration.
class var_decl : public virtual decl_base
{
  struct priv;
  std::unique_ptr<priv> priv_;
 
  // Forbidden
  var_decl();
 
  virtual void
  set_scope(scope_decl*);
 
public:
 
  /// Hasher for a var_decl type.
  struct hash;
 
  /// Equality functor to compare pointers to variable_decl.
  struct ptr_equal;
 
  var_decl(const string&    name,
       type_base_sptr   type,
       const location&  locus,
       const string&    mangled_name,
       visibility       vis = VISIBILITY_DEFAULT,
       binding      bind = BINDING_NONE);
 
  virtual bool
  operator==(const decl_base&) const;
 
  const type_base_sptr
  get_type() const;
 
  void
  set_type(type_base_sptr&);
 
  const type_base*
  get_naked_type() const;
 
  binding
  get_binding() const;
 
  void
  set_binding(binding b);
 
  void
  set_symbol(const elf_symbol_sptr& sym);
 
  const elf_symbol_sptr&
  get_symbol() const;
 
  var_decl_sptr
  clone() const;
 
  interned_string
  get_id() const;
 
  virtual const interned_string&
  get_qualified_name(bool internal = false) const;
 
  virtual size_t
  get_hash() const;
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const;
 
  string
  get_anon_dm_reliable_name(bool qualified = true) const;
 
  virtual bool
  traverse(ir_node_visitor& v);
 
  virtual ~var_decl();
 
  friend void
  set_data_member_offset(var_decl_sptr m, uint64_t o);
 
  friend uint64_t
  get_data_member_offset(const var_decl_sptr m);
 
  friend uint64_t
  get_data_member_offset(const var_decl& m);
 
  friend uint64_t
  get_absolute_data_member_offset(const var_decl& m);
 
  friend uint64_t
  get_absolute_data_member_offset(const var_decl_sptr& m);
 
  friend void
  set_data_member_is_laid_out(var_decl_sptr m, bool l);
 
  friend bool
  get_data_member_is_laid_out(const var_decl& m);
 
  friend bool
  get_data_member_is_laid_out(const var_decl_sptr m);
}; // end class var_decl
 
bool
equals(const function_decl&, const function_decl&, change_kind*);
 
/// Abstraction for a function declaration.
class function_decl : public virtual decl_base
{
  struct priv;
  // This priv pointer is not handled by a shared_ptr because
  // accessing the data members of the priv struct for this
  // function_decl shows up on performance profiles when dealing with
  // big binaries with a lot of types; dereferencing the shared_ptr
  // involves locking of some sort and that is slower than just
  // dereferencing a pointer likere here.  There are other types for
  // which the priv pointer is managed using shared_ptr just fine,
  // because those didn't show up during our performance profiling.
  priv* priv_;
 
public:
  /// Hasher for function_decl
  struct hash;
 
  /// Equality functor to compare pointers to function_decl
  struct ptr_equal;
 
  /// Abstraction for the parameter of a function.
  class parameter;
 
  /// Convenience typedef for a shared pointer on a @ref
  /// function_decl::parameter
  typedef shared_ptr<parameter> parameter_sptr;
 
  /// Convenience typedef for a vector of @ref parameter_sptr
  typedef std::vector<parameter_sptr> parameters;
 
  function_decl(const string& name,
        function_type_sptr function_type,
        bool declared_inline,
        const location& locus,
        const string& mangled_name,
        visibility vis,
        binding bind);
 
  function_decl(const string& name,
        type_base_sptr fn_type,
        bool declared_inline,
        const location& locus,
        const string& mangled_name = "",
        visibility vis = VISIBILITY_DEFAULT,
        binding bind = BINDING_GLOBAL);
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const;
 
  string
  get_pretty_representation_of_declarator (bool internal = false) const;
 
  const std::vector<parameter_sptr >&
  get_parameters() const;
 
  void
  append_parameter(parameter_sptr parm);
 
  void
  append_parameters(std::vector<parameter_sptr >& parms);
 
  parameters::const_iterator
  get_first_non_implicit_parm() const;
 
  const function_type_sptr
  get_type() const;
 
  const function_type*
  get_naked_type() const;
 
  const type_base_sptr
  get_return_type() const;
 
  void
  set_type(const function_type_sptr& fn_type);
 
  void
  set_symbol(const elf_symbol_sptr& sym);
 
  const elf_symbol_sptr&
  get_symbol() const;
 
  bool
  is_declared_inline() const;
 
  binding
  get_binding() const;
 
  function_decl_sptr
  clone() const;
 
  virtual bool
  operator==(const decl_base& o) const;
 
  /// Return true iff the function takes a variable number of
  /// parameters.
  ///
  /// @return true if the function taks a variable number
  /// of parameters.
  bool
  is_variadic() const;
 
  virtual size_t
  get_hash() const;
 
  interned_string
  get_id() const;
 
  virtual bool
  traverse(ir_node_visitor&);
 
  virtual ~function_decl();
}; // end class function_decl
 
bool
operator==(const function_decl_sptr& l, const function_decl_sptr& r);
 
bool
operator!=(const function_decl_sptr& l, const function_decl_sptr& r);
 
bool
function_decls_alias(const function_decl& f1, const function_decl& f2);
 
bool
equals(const function_decl::parameter&,
       const function_decl::parameter&,
       change_kind*);
 
/// A comparison functor to compare pointer to instances of @ref
/// type_or_decl_base.
struct type_or_decl_base_comp
{
  /// Comparison operator for ABI artifacts.
  ///
  /// @param f the first ABI artifact to consider for the comparison.
  ///
  /// @param s the second  ABI artifact to consider for the comparison.
  ///
  /// @return true iff @p f is lexicographically less than than @p s.
  bool
  operator()(const type_or_decl_base *f,
         const type_or_decl_base *s)
  {
    function_decl *f_fn = is_function_decl(f), *s_fn = is_function_decl(s);
    if (f_fn && s_fn)
      return function_decl_is_less_than(*f_fn, *s_fn);
 
    var_decl *f_var = is_var_decl(f), *s_var = is_var_decl(s);
    if (f_var && s_var)
      return get_name(f_var) < get_name(s_var);
 
    string l_repr = get_pretty_representation(f),
      r_repr = get_pretty_representation(s);
 
    return l_repr < r_repr;
  }
 
  /// Comparison operator for ABI artifacts.
  ///
  /// @param f the first ABI artifact to consider for the comparison.
  ///
  /// @param s the second  ABI artifact to consider for the comparison.
  ///
  /// @return true iff @p f is lexicographically less than than @p s.
  bool
  operator()(const type_or_decl_base_sptr& f,
         const type_or_decl_base_sptr& s)
  {return operator()(f.get(), s.get());}
}; // end struct type_or_decl_base_comp
 
/// Abstraction of a function parameter.
class function_decl::parameter : public decl_base
{
  struct priv;
  std::unique_ptr<priv> priv_;
 
public:
 
  /// Hasher for an instance of function::parameter
  struct hash;
 
  parameter(const type_base_sptr    type,
        unsigned            index,
        const string&       name,
        const location&     loc,
        bool            variadic_marker = false);
 
  parameter(const type_base_sptr    type,
        unsigned            index,
        const string&       name,
        const location&     loc,
        bool            variadic_marker,
        bool            is_artificial);
 
  parameter(const type_base_sptr    type,
        const string&       name,
        const location&     loc,
        bool            variadic_marker = false,
        bool            is_artificial   = false);
 
  parameter(const type_base_sptr    type,
        unsigned            index = 0,
        bool            variadic_marker = false);
 
  virtual ~parameter();
 
  const type_base_sptr
  get_type()const;
 
  interned_string
  get_type_name() const;
 
  const string
  get_type_pretty_representation() const;
 
  interned_string
  get_name_id() const;
 
  unsigned
  get_index() const;
 
  void
  set_index(unsigned i);
 
  bool
  get_variadic_marker() const;
 
  bool
  operator==(const parameter& o) const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  traverse(ir_node_visitor& v);
 
  virtual size_t
  get_hash() const;
 
  virtual void
  get_qualified_name(interned_string& qualified_name,
             bool internal = false) const;
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const;
}; // end class function_decl::parameter
 
bool
operator==(const function_decl::parameter_sptr&,
       const function_decl::parameter_sptr&);
 
/// A hashing functor for a function_decl::parameter.
struct function_decl::parameter::hash
{
  size_t
  operator()(const function_decl::parameter&) const;
 
  size_t
  operator()(const function_decl::parameter*) const;
 
  size_t
  operator()(const function_decl::parameter_sptr) const;
}; // end struct function_decl::parameter::hash
 
function_decl::parameter*
is_function_parameter(const type_or_decl_base*);
 
function_decl::parameter_sptr
is_function_parameter(const type_or_decl_base_sptr tod);
 
bool
equals(const function_type&, const function_type&, change_kind*);
 
/// Abstraction of a function type.
class function_type : public virtual type_base
{
protected:
  virtual void on_canonical_type_set();
 
public:
  /// Hasher for an instance of function_type
  struct hash;
 
  /// Convenience typedef for a shared pointer on a @ref
  /// function_decl::parameter
  typedef shared_ptr<function_decl::parameter>  parameter_sptr;
  /// Convenience typedef for a vector of @ref parameter_sptr
  typedef std::vector<parameter_sptr>       parameters;
 
  struct priv;
  std::unique_ptr<priv> priv_;
 
private:
  function_type();
 
public:
 
  function_type(type_base_sptr      return_type,
        const parameters&   parms,
        size_t          size_in_bits,
        size_t          alignment_in_bits);
 
  function_type(type_base_sptr  return_type,
        size_t      size_in_bits,
        size_t      alignment_in_bits);
 
  function_type(const environment&  env,
        size_t      size_in_bits,
        size_t      alignment_in_bits);
 
  type_base_sptr
  get_return_type() const;
 
  void
  set_return_type(type_base_sptr t);
 
  const parameters&
  get_parameters() const;
 
  const parameter_sptr
  get_parm_at_index_from_first_non_implicit_parm(size_t) const;
 
  void
  set_parameters(const parameters &p);
 
  void
  append_parameter(parameter_sptr parm);
 
  bool
  is_variadic() const;
 
  parameters::const_iterator
  get_first_non_implicit_parm() const;
 
  parameters::const_iterator
  get_first_parm() const;
 
  const interned_string&
  get_cached_name(bool internal = false) const;
 
  virtual bool
  operator==(const type_base&) const;
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const;
 
  virtual bool
  traverse(ir_node_visitor&);
 
  virtual ~function_type();
 
  friend bool
  equals(const function_type&, const function_type&, change_kind*);
};//end class function_type
 
/// The hashing functor for @ref function_type.
struct function_type::hash
{
  size_t
  operator()(const function_type& t) const;
 
  size_t
  operator()(const function_type* t) const;
 
  size_t
  operator()(const function_type_sptr t) const;
};// end struct function_type::hash
 
/// Abstracts the type of a class member function.
class method_type : public function_type
{
  struct priv;
  std::unique_ptr<priv> priv_;
 
  method_type();
 
public:
 
  /// Hasher for intances of method_type
  struct hash;
 
  method_type(type_base_sptr return_type,
          class_or_union_sptr class_type,
          const std::vector<function_decl::parameter_sptr>& parms,
          bool is_const,
          size_t size_in_bits,
          size_t alignment_in_bits);
 
  method_type(type_base_sptr return_type,
          type_base_sptr class_type,
          const std::vector<function_decl::parameter_sptr>& parms,
          bool is_const,
          size_t size_in_bits,
          size_t alignment_in_bits);
 
  method_type(class_or_union_sptr class_type,
          bool is_const,
          size_t size_in_bits,
          size_t alignment_in_bits);
 
  method_type(const environment& env,
          size_t size_in_bits,
          size_t alignment_in_bits);
 
  class_or_union_sptr
  get_class_type() const;
 
  void
  set_class_type(const class_or_union_sptr& t);
 
  void set_is_const(bool);
 
  bool get_is_const() const;
 
  virtual ~method_type();
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const;
 
  friend interned_string
  get_method_type_name(const method_type& fn_type, bool internal);
};// end class method_type.
 
/// The base class of templates.
class template_decl : public virtual decl_base
{
  class priv;
  std::unique_ptr<priv> priv_;
 
  template_decl();
 
public:
 
  /// Hasher.
  struct hash;
 
  template_decl(const environment&  env,
        const string&       name,
        const location& locus,
        visibility      vis = VISIBILITY_DEFAULT);
 
  void
  add_template_parameter(const template_parameter_sptr p);
 
  const std::list<template_parameter_sptr>&
  get_template_parameters() const;
 
  virtual bool
  operator==(const decl_base& o) const;
 
  virtual bool
  operator==(const template_decl& o) const;
 
  virtual ~template_decl();
};//end class template_decl
 
/// Base class for a template parameter.  Client code should use the
/// more specialized type_template_parameter,
/// non_type_template_parameter and template_template_parameter below.
class template_parameter
{
  class priv;
  std::unique_ptr<priv> priv_;
 
  // Forbidden
  template_parameter();
 
 public:
 
  /// Hashers.
  struct hash;
  struct dynamic_hash;
  struct shared_ptr_hash;
 
  template_parameter(unsigned           index,
             template_decl_sptr enclosing_tdecl);
 
  virtual bool
  operator==(const template_parameter&) const;
 
  bool
  operator!=(const template_parameter&) const;
 
  unsigned
  get_index() const;
 
  const template_decl_sptr
  get_enclosing_template_decl() const;
 
  bool
  get_hashing_has_started() const;
 
  void
  set_hashing_has_started(bool f) const;
 
  virtual ~template_parameter();
};//end class template_parameter
 
struct template_decl::hash
{
    size_t
    operator()(const template_decl& t) const;
};// end struct template_decl::hash
 
/// Abstracts a type template parameter.
class type_tparameter : public template_parameter, public virtual type_decl
{
  class priv;
  std::unique_ptr<priv> priv_;
 
  // Forbidden
  type_tparameter();
 
public:
 
  /// Hasher.
  struct hash;
 
  type_tparameter(unsigned      index,
          template_decl_sptr    enclosing_tdecl,
          const string& name,
          const location&   locus);
 
  virtual bool
  operator==(const type_base&) const;
 
  virtual bool
  operator==(const type_decl&) const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const template_parameter&) const;
 
  virtual bool
  operator==(const type_tparameter&) const;
 
  virtual ~type_tparameter();
};// end class type_tparameter.
 
/// Abstracts non type template parameters.
class non_type_tparameter : public template_parameter, public virtual decl_base
{
  class priv;
  std::unique_ptr<priv> priv_;
 
  type_base_wptr type_;
 
  // Forbidden
  non_type_tparameter();
 
public:
  /// Hasher.
  struct hash;
 
  non_type_tparameter(unsigned          index,
              template_decl_sptr    enclosing_tdecl,
              const string&     name,
              type_base_sptr        type,
              const location&       locus);
  virtual size_t
  get_hash() const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const template_parameter&) const;
 
  const type_base_sptr
  get_type() const;
 
  virtual ~non_type_tparameter();
};// end class non_type_tparameter
 
/// Hasher for the @ref non_type_tparameter type.
struct non_type_tparameter::hash
{
  size_t
  operator()(const non_type_tparameter& t) const;
 
  size_t
  operator()(const non_type_tparameter* t) const;
};
 
class template_tparameter;
 
/// Abstracts a template template parameter.
class template_tparameter : public type_tparameter, public template_decl
{
  class priv;
  std::unique_ptr<priv> priv_;
 
  // Forbidden
  template_tparameter();
 
public:
 
  /// A hasher for instances of template_tparameter
  struct hash;
 
  template_tparameter(unsigned          index,
              template_decl_sptr    enclosing_tdecl,
              const string&     name,
              const location&       locus);
 
  virtual bool
  operator==(const type_base&) const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const template_parameter&) const;
 
  virtual bool
  operator==(const template_decl&) const;
 
  virtual ~template_tparameter();
};
 
/// This abstracts a composition of types based on template type
/// parameters.  The result of the composition is a type that can be
/// referred to by a template non-type parameter.  Instances of this
/// type can appear at the same level as template parameters, in the
/// scope of a template_decl.
class type_composition : public template_parameter, public virtual decl_base
{
  class priv;
  std::unique_ptr<priv> priv_;
 
  type_composition();
 
public:
  struct hash;
 
  type_composition(unsigned     index,
           template_decl_sptr   tdecl,
           type_base_sptr   composed_type);
 
  const type_base_sptr
  get_composed_type() const;
 
  void
  set_composed_type(type_base_sptr t);
 
  virtual size_t
  get_hash() const;
 
  virtual ~type_composition();
};
 
/// Hasher for the @ref type_composition type.
struct type_composition::hash
{
  size_t
  operator()(const type_composition& t) const;
 
  size_t
  operator()(const type_composition* t) const;
 
}; //struct type_composition::hash
 
/// Abstract a function template declaration.
class function_tdecl : public template_decl, public scope_decl
{
  class priv;
  std::unique_ptr<priv> priv_;
 
  // Forbidden
  function_tdecl();
 
public:
 
  /// Hash functor for function templates.
  struct hash;
  struct shared_ptr_hash;
 
  function_tdecl(const environment& env,
         const location&    locus,
         visibility     vis = VISIBILITY_DEFAULT,
         binding        bind = BINDING_NONE);
 
  function_tdecl(function_decl_sptr pattern,
         const location&    locus,
         visibility     vis = VISIBILITY_DEFAULT,
         binding        bind = BINDING_NONE);
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const template_decl&) const;
 
  virtual bool
  operator==(const function_tdecl&) const;
 
  void
  set_pattern(shared_ptr<function_decl> p);
 
  shared_ptr<function_decl>
  get_pattern() const;
 
  binding
  get_binding() const;
 
  virtual bool
  traverse(ir_node_visitor& v);
 
  virtual ~function_tdecl();
}; // end class function_tdecl.
 
/// Abstract a class template.
class class_tdecl : public template_decl, public scope_decl
{
  class priv;
  std::unique_ptr<priv> priv_;
 
  // Forbidden
  class_tdecl();
 
public:
 
  /// Hashers.
  struct hash;
  struct shared_ptr_hash;
 
  class_tdecl(const environment& env, const location& locus,
          visibility vis = VISIBILITY_DEFAULT);
 
  class_tdecl(class_decl_sptr   pattern,
          const location&   locus,
          visibility    vis = VISIBILITY_DEFAULT);
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const template_decl&) const;
 
  virtual bool
  operator==(const class_tdecl&) const;
 
  void
  set_pattern(class_decl_sptr p);
 
  shared_ptr<class_decl>
  get_pattern() const;
 
  virtual bool
  traverse(ir_node_visitor& v);
 
  virtual ~class_tdecl();
};// end class class_tdecl
 
/// The base class for member types, data members and member
/// functions.  Its purpose is mainly to carry the access specifier
/// (and possibly other properties that might be shared by all class
/// members) for the member.
class member_base
{
protected:
  enum access_specifier access_;
  bool          is_static_;
 
private:
  // Forbidden
  member_base();
 
public:
  /// Hasher.
  struct hash;
 
  member_base(access_specifier a, bool is_static = false)
    : access_(a), is_static_(is_static)
  {}
 
  /// Getter for the access specifier of this member.
  ///
  /// @return the access specifier for this member.
  access_specifier
  get_access_specifier() const
  {return access_;}
 
  /// Setter for the access specifier of this member.
  ///
  /// @param a the new access specifier.
  void
  set_access_specifier(access_specifier a)
  {access_ = a;}
 
  /// @return true if the member is static, false otherwise.
  bool
  get_is_static() const
  {return is_static_;}
 
  /// Set a flag saying if the parameter is static or not.
  ///
  /// @param f set to true if the member is static, false otherwise.
  void
  set_is_static(bool f)
  {is_static_ = f;}
 
  virtual bool
  operator==(const member_base& o) const;
};// end class member_base
 
/// Abstraction of the declaration of a method.
class method_decl : public function_decl
{
  method_decl();
 
  virtual void
  set_scope(scope_decl*);
 
public:
 
  method_decl(const string& name, method_type_sptr type,
          bool declared_inline, const location& locus,
          const string& mangled_name = "",
          visibility vis = VISIBILITY_DEFAULT,
          binding   bind = BINDING_GLOBAL);
 
  method_decl(const string& name,
          function_type_sptr type,
          bool declared_inline,
          const location& locus,
          const string& mangled_name = "",
          visibility vis  = VISIBILITY_DEFAULT,
          binding   bind = BINDING_GLOBAL);
 
  method_decl(const string& name, type_base_sptr type,
          bool declared_inline, const location& locus,
          const string& mangled_name = "",
          visibility vis = VISIBILITY_DEFAULT,
          binding bind = BINDING_GLOBAL);
 
  virtual void
  set_linkage_name(const string&);
 
  /// @return the type of the current instance of the
  /// method_decl.
  const method_type_sptr
  get_type() const;
 
  void
  set_type(const method_type_sptr fn_type)
  {function_decl::set_type(fn_type);}
 
  friend bool
  get_member_function_is_ctor(const function_decl&);
 
  friend void
  set_member_function_is_ctor(function_decl&, bool);
 
  friend void
  set_member_function_is_ctor(const function_decl_sptr&, bool);
 
  friend bool
  get_member_function_is_dtor(const function_decl&);
 
  friend void
  set_member_function_is_dtor(function_decl&, bool);
 
  friend void
  set_member_function_is_dtor(const function_decl_sptr&, bool);
 
  friend bool
  get_member_function_is_static(const function_decl&);
 
  friend void
  set_member_function_is_static(const function_decl&, bool);
 
  friend bool
  get_member_function_is_const(const function_decl&);
 
  friend void
  set_member_function_is_const(function_decl&, bool);
 
  friend void
  set_member_function_is_const(const function_decl_sptr&, bool);
 
  friend bool
  member_function_has_vtable_offset(const function_decl&);
 
  friend ssize_t
  get_member_function_vtable_offset(const function_decl&);
 
  friend void
  set_member_function_vtable_offset(function_decl&, ssize_t);
 
  friend void
  set_member_function_vtable_offset(const function_decl_sptr&, ssize_t);
 
  friend bool
  get_member_function_is_virtual(const function_decl&);
 
  friend void
  set_member_function_is_virtual(function_decl&, bool);
 
  virtual ~method_decl();
};// end class method_decl
 
bool
operator==(const method_decl_sptr& l, const method_decl_sptr& r);
 
bool
operator!=(const method_decl_sptr& l, const method_decl_sptr& r);
 
/// The base type of @ref class_decl and @ref union_decl
class class_or_union : public scope_type_decl
{
public:
  struct priv;
  priv *priv_;
 
private:
  // Forbidden
  class_or_union();
 
protected:
 
  virtual decl_base_sptr
  add_member_decl(const decl_base_sptr&);
 
  decl_base_sptr
  insert_member_decl(decl_base_sptr member);
 
  virtual void
  remove_member_decl(decl_base_sptr);
 
  void
  maybe_fixup_members_of_anon_data_member(var_decl_sptr& anon_dm);
 
public:
  /// Hasher.
  struct hash;
 
  /// Convenience typedef
  /// @{
  typedef vector<type_base_sptr>        member_types;
  typedef vector<var_decl_sptr>     data_members;
  typedef vector<method_decl_sptr>      member_functions;
  typedef unordered_map<ssize_t, member_functions> virtual_mem_fn_map_type;
  typedef unordered_map<string, method_decl*> string_mem_fn_ptr_map_type;
  typedef unordered_map<string, method_decl_sptr> string_mem_fn_sptr_map_type;
  /// @}
 
  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& mbrs, data_members& data_mbrs,
         member_functions& member_fns);
 
  class_or_union(const environment& env, const string& name,
         size_t size_in_bits, size_t align_in_bits,
         const location& locus, visibility vis);
 
  class_or_union(const environment& env, const string& name,
         bool is_declaration_only = true);
 
  virtual void
  set_size_in_bits(size_t);
 
  virtual size_t
  get_size_in_bits() const;
 
  virtual size_t
  get_alignment_in_bits() const;
 
  virtual void
  set_alignment_in_bits(size_t);
 
  virtual size_t
  get_num_anonymous_member_classes() const;
 
  virtual size_t
  get_num_anonymous_member_unions() const;
 
  virtual size_t
  get_num_anonymous_member_enums() const;
 
  void
  add_data_member(var_decl_sptr v, access_specifier a,
          bool is_laid_out, bool is_static,
          size_t offset_in_bits);
 
  const data_members&
  get_data_members() const;
 
  const var_decl_sptr
  find_data_member(const string&) const;
 
  const var_decl_sptr
  find_data_member(const var_decl_sptr&) const;
 
  const var_decl_sptr
  find_anonymous_data_member(const var_decl_sptr&) const;
 
  const data_members&
  get_non_static_data_members() const;
 
  void
  add_member_function(method_decl_sptr f,
              access_specifier a,
              bool is_static, bool is_ctor,
              bool is_dtor, bool is_const);
 
  void
  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);
 
  const member_functions&
  get_member_functions() const;
 
  const method_decl*
  find_member_function(const string& mangled_name) const;
 
  method_decl*
  find_member_function(const string& mangled_name);
 
  method_decl_sptr
  find_member_function_sptr(const string& mangled_name);
 
  const method_decl*
  find_member_function_from_signature(const string& s) const;
 
  method_decl*
  find_member_function_from_signature(const string& s);
 
  void
  add_member_function_template(member_function_template_sptr);
 
  const member_function_templates&
  get_member_function_templates() const;
 
  void
  add_member_class_template(member_class_template_sptr m);
 
  const member_class_templates&
  get_member_class_templates() const;
 
  bool
  has_no_member() const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const type_base&) const;
 
  virtual bool
  operator==(const class_or_union&) const;
 
  virtual bool
  traverse(ir_node_visitor& v);
 
  virtual ~class_or_union();
 
  friend method_decl_sptr
  copy_member_function(class_or_union_sptr& t,
               const method_decl*m);
 
  friend method_decl_sptr
  copy_member_function(class_or_union_sptr& t,
               const method_decl_sptr& m);
 
  friend void
  fixup_virtual_member_function(method_decl_sptr method);
 
  friend void
  set_member_is_static(decl_base& d, bool s);
 
  friend bool
  equals(const class_or_union&, const class_or_union&, change_kind*);
 
  friend bool
  equals(const class_decl&, const class_decl&, change_kind*);
 
  friend class method_decl;
  friend class class_decl;
}; // end class class_or_union
 
method_decl_sptr
copy_member_function(const class_or_union_sptr& clazz,
             const method_decl_sptr& f);
 
method_decl_sptr
copy_member_function(const class_or_union_sptr& clazz,
             const method_decl* f);
 
bool
operator==(const class_or_union_sptr& l, const class_or_union_sptr& r);
 
bool
operator!=(const class_or_union_sptr& l, const class_or_union_sptr& r);
 
/// Hasher for the @ref class_or_union type
struct class_or_union::hash
{
  size_t
  operator()(const class_or_union& t) const;
 
  size_t
  operator()(const class_or_union* t) const;
}; // end struct class_decl::hash
 
/// Abstracts a class declaration.
class class_decl : public class_or_union
{
  // Forbidden
  class_decl();
 
protected:
 
  decl_base_sptr
  insert_member_decl(decl_base_sptr member);
 
public:
  /// Hasher.
  struct hash;
 
  /// Forward declarations.
  class base_spec;
 
  /// Convenience typedef
  /// @{
  typedef shared_ptr<base_spec>         base_spec_sptr;
  typedef vector<base_spec_sptr>            base_specs;
 
  /// @}
 
protected:
  virtual void
  on_canonical_type_set();
 
private:
  struct priv;
  // This priv it's not handled by a shared_ptr because accessing the
  // data members of the priv struct for this class_decl shows up on
  // performance profiles when dealing with big binaries with a lot of
  // types; dereferencing the shared_ptr involves locking of some sort
  // and that is slower than just dereferencing a pointer likere here.
  // There are other types for which the priv pointer is managed using
  // shared_ptr just fine, because those didn't show up during our
  // performance profiling.
  priv * priv_;
 
public:
 
  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& mbrs, data_members& data_mbrs,
         member_functions& member_fns);
 
  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& mbrs, data_members& data_mbrs,
         member_functions& member_fns, bool is_anonymous);
 
  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);
 
  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);
 
  class_decl(const environment& env, const string& name, bool is_struct,
         bool is_declaration_only = true);
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const;
 
  void
  is_struct(bool f);
 
  bool
  is_struct() const;
 
  void
  add_base_specifier(shared_ptr<base_spec> b);
 
  const base_specs&
  get_base_specifiers() const;
 
  class_decl_sptr
  find_base_class(const string&) const;
 
  const member_functions&
  get_virtual_mem_fns() const;
 
  const virtual_mem_fn_map_type&
  get_virtual_mem_fns_map() const;
 
  void
  sort_virtual_mem_fns();
 
  bool
  has_no_base_nor_member() const;
 
  bool
  has_virtual_member_functions() const;
 
  bool
  has_virtual_bases() const;
 
  bool
  has_vtable() const;
 
  ssize_t
  get_biggest_vtable_offset() const;
 
  virtual size_t
  get_hash() const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const type_base&) const;
 
  virtual bool
  operator==(const class_or_union&) const;
 
  virtual bool
  operator==(const class_decl&) const;
 
  virtual bool
  traverse(ir_node_visitor& v);
 
  virtual ~class_decl();
 
  friend void
  fixup_virtual_member_function(method_decl_sptr method);
 
  friend void
  set_member_is_static(decl_base& d, bool s);
 
  friend bool
  equals(const class_decl&, const class_decl&, change_kind*);
 
  friend class method_decl;
  friend class class_or_union;
};// end class class_decl
 
bool
equals(const class_decl&, const class_decl&, change_kind*);
 
method_decl_sptr
copy_member_function(const class_decl_sptr& clazz,
             const method_decl_sptr& f);
 
method_decl_sptr
copy_member_function(const class_decl_sptr& clazz,
             const method_decl* f);
void
fixup_virtual_member_function(method_decl_sptr method);
 
/// Hasher for the @ref class_decl type
struct class_decl::hash
{
  size_t
  operator()(const class_decl& t) const;
 
  size_t
  operator()(const class_decl* t) const;
}; // end struct class_decl::hash
 
enum access_specifier
get_member_access_specifier(const decl_base&);
 
enum access_specifier
get_member_access_specifier(const decl_base_sptr&);
 
void
set_member_access_specifier(decl_base&,
                access_specifier);
 
void
set_member_access_specifier(const decl_base_sptr&,
                access_specifier);
 
std::ostream&
operator<<(std::ostream&, access_specifier);
 
bool
operator==(const class_decl_sptr& l, const class_decl_sptr& r);
 
bool
operator!=(const class_decl_sptr& l, const class_decl_sptr& r);
 
bool
equals(const class_decl::base_spec&,
       const class_decl::base_spec&,
       change_kind*);
 
/// Abstraction of a base specifier in a class declaration.
class class_decl::base_spec : public member_base,
                  public virtual decl_base
{
  struct priv;
  std::unique_ptr<priv> priv_;
 
  // Forbidden
  base_spec();
 
public:
 
  /// Hasher.
  struct hash;
 
  base_spec(const class_decl_sptr& base, access_specifier a,
        long offset_in_bits = -1, bool is_virtual = false);
 
  base_spec(const type_base_sptr& base, access_specifier a,
        long offset_in_bits = -1, bool is_virtual = false);
 
  virtual ~base_spec();
 
  class_decl_sptr
  get_base_class() const;
 
  bool
  get_is_virtual() const;
 
  long
  get_offset_in_bits() const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const member_base&) const;
 
  virtual size_t
  get_hash() const;
 
  virtual bool
  traverse(ir_node_visitor&);
};// end class class_decl::base_spec
 
bool
operator==(const class_decl::base_spec_sptr& l,
       const class_decl::base_spec_sptr& r);
 
bool
operator!=(const class_decl::base_spec_sptr& l,
       const class_decl::base_spec_sptr& r);
 
class_decl::base_spec*
is_class_base_spec(type_or_decl_base*);
 
class_decl::base_spec_sptr
is_class_base_spec(type_or_decl_base_sptr);
 
/// Abstracts a union type declaration.
class union_decl : public class_or_union
{
  // Forbid
  union_decl();
 
public:
 
  union_decl(const environment& env, const string& name,
         size_t size_in_bits, const location& locus,
         visibility vis, member_types& mbrs,
         data_members& data_mbrs, member_functions& member_fns);
 
  union_decl(const environment& env, const string& name,
         size_t size_in_bits, const location& locus,
         visibility vis, member_types& mbrs,
         data_members& data_mbrs, member_functions& member_fns,
         bool is_anonymous);
 
  union_decl(const environment& env, const string& name,
         size_t size_in_bits, const location& locus,
         visibility vis);
 
  union_decl(const environment& env, const string& name,
         size_t size_in_bits, const location& locus,
         visibility vis, bool is_anonymous);
 
  union_decl(const environment& env, const string& name,
         bool is_declaration_only = true);
 
  virtual string
  get_pretty_representation(bool internal = false,
                bool qualified_name = true) const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const type_base&) const;
 
  virtual bool
  operator==(const class_or_union&) const;
 
  virtual bool
  operator==(const union_decl&) const;
 
  virtual bool
  traverse(ir_node_visitor& v);
 
  virtual ~union_decl();
}; // union_decl
 
bool
equals(const union_decl&, const union_decl&, change_kind*);
 
method_decl_sptr
copy_member_function(const union_decl_sptr& union_type,
             const method_decl_sptr& f);
 
method_decl_sptr
copy_member_function(const union_decl_sptr& union_type,
             const method_decl* f);
 
bool
operator==(const union_decl_sptr& l, const union_decl_sptr& r);
 
bool
operator!=(const union_decl_sptr& l, const union_decl_sptr& r);
 
/// Abstraction of a member function context relationship.  This
/// relates a member function to its parent class.
class mem_fn_context_rel : public context_rel
{
protected:
  bool      is_virtual_;
  ssize_t   vtable_offset_in_bits_;
  bool      is_constructor_;
  bool      is_destructor_;
  bool      is_const_;
 
public:
  mem_fn_context_rel()
    : context_rel(),
      is_virtual_(false),
      vtable_offset_in_bits_(-1),
      is_constructor_(false),
      is_destructor_(false),
      is_const_(false)
  {}
 
  mem_fn_context_rel(scope_decl* s)
    : context_rel(s),
      is_virtual_(false),
      vtable_offset_in_bits_(-1),
      is_constructor_(false),
      is_destructor_(false),
      is_const_(false)
  {}
 
  mem_fn_context_rel(scope_decl* s,
             bool is_constructor,
             bool is_destructor,
             bool is_const,
             bool is_virtual,
             size_t vtable_offset_in_bits,
             access_specifier access,
             bool is_static)
    : context_rel(s, access, is_static),
      is_virtual_(is_virtual),
      vtable_offset_in_bits_(vtable_offset_in_bits),
      is_constructor_(is_constructor),
      is_destructor_(is_destructor),
      is_const_(is_const)
  {}
 
  bool
  is_virtual() const
  {return is_virtual_;}
 
  void
  is_virtual(bool is_virtual)
  {is_virtual_ = is_virtual;}
 
  /// Getter for the vtable offset property.
  ///
  /// This is the vtable offset of the member function of this
  /// relation.
  ///
  /// @return the vtable offset property of the relation.
  size_t
  vtable_offset() const
  {return vtable_offset_in_bits_;}
 
  /// Setter for the vtable offset property.
  ///
  /// This is the vtable offset of the member function of this
  /// relation.
  ///
  /// @partam s the new vtable offset.
  void
  vtable_offset(size_t s)
  {vtable_offset_in_bits_ = s;}
 
  /// Getter for the 'is-constructor' property.
  ///
  /// This tells if the member function of this relation is a
  /// constructor.
  ///
  /// @return the is-constructor property of the relation.
  bool
  is_constructor() const
  {return is_constructor_;}
 
  /// Setter for the 'is-constructor' property.
  ///
  /// @param f the new value of the the property.  Is true if this is
  /// for a constructor, false otherwise.
  void
  is_constructor(bool f)
  {is_constructor_ = f;}
 
  /// Getter for the 'is-destructor' property.
  ///
  /// Tells if the member function of this relation is a destructor.
  ///
  /// @return the is-destructor property of the relation;
  bool
  is_destructor() const
  {return is_destructor_;}
 
  /// Setter for the 'is-destructor' property.
  ///
  /// @param f the new value of the property.  Is true if this is for
  /// a destructor, false otherwise.
  void
  is_destructor(bool f)
  {is_destructor_ = f;}
 
  /// Getter for the 'is-const' property.
  ///
  /// Tells if the member function of this relation is a const member
  /// function.
  ///
  /// @return the 'is-const' property of the relation.
  bool
  is_const() const
  {return is_const_;}
 
  /// Setter for the 'is-const' property.
  ///
  /// @param f the new value of the property.  Is true if this is for
  /// a const entity, false otherwise.
  void
  is_const(bool f)
  {is_const_ = f;}
 
  virtual ~mem_fn_context_rel();
}; // end class mem_fn_context_rel
 
method_decl*
is_method_decl(const type_or_decl_base*);
 
method_decl*
is_method_decl(const type_or_decl_base&);
 
method_decl_sptr
is_method_decl(const type_or_decl_base_sptr&);
 
const var_decl*
lookup_data_member(const type_base* type,
           const char* dm_name);
 
const function_decl::parameter*
get_function_parameter(const decl_base* fun,
               unsigned parm_num);
 
/// Abstract a member function template.
class member_function_template : public member_base, public virtual decl_base
{
  bool is_constructor_;
  bool is_const_;
  shared_ptr<function_tdecl> fn_tmpl_;
 
  // Forbiden
  member_function_template();
 
public:
  /// Hasher.
  struct hash;
 
  member_function_template(function_tdecl_sptr f,
               access_specifier access, bool is_static,
               bool is_constructor, bool is_const)
    : type_or_decl_base(f->get_environment()),
      decl_base(f->get_environment(), f->get_name(), location()),
      member_base(access, is_static), is_constructor_(is_constructor),
      is_const_(is_const), fn_tmpl_(f)
  {}
 
  bool
  is_constructor() const
  {return is_constructor_;}
 
  bool
  is_const() const
  {return is_const_;}
 
  operator const function_tdecl& () const
  {return *fn_tmpl_;}
 
  function_tdecl_sptr
  as_function_tdecl() const
  {return fn_tmpl_;}
 
  virtual bool
  operator==(const member_base& o) const;
 
  virtual bool
  traverse(ir_node_visitor&);
};// end class member_function_template
 
bool
operator==(const member_function_template_sptr& l,
       const member_function_template_sptr& r);
 
bool
operator!=(const member_function_template_sptr& l,
       const member_function_template_sptr& r);
 
/// Abstracts a member class template template
class member_class_template
  : public member_base,
    public virtual decl_base
{
  shared_ptr<class_tdecl> class_tmpl_;
 
  // Forbidden
  member_class_template();
 
public:
 
  /// Hasher.
  struct hash;
 
  member_class_template(class_tdecl_sptr c,
            access_specifier access, bool is_static)
    : type_or_decl_base(c->get_environment()),
      decl_base(c->get_environment(), c->get_name(), location()),
      member_base(access, is_static),
      class_tmpl_(c)
  {}
 
  operator const class_tdecl& () const
  { return *class_tmpl_; }
 
  class_tdecl_sptr
  as_class_tdecl() const
  {return class_tmpl_;}
 
  virtual bool
  operator==(const member_base& o) const;
 
  virtual bool
  operator==(const decl_base&) const;
 
  virtual bool
  operator==(const member_class_template&) const;
 
  virtual bool
  traverse(ir_node_visitor& v);
};// end class member_class_template
 
bool
operator==(const member_class_template_sptr& l,
       const member_class_template_sptr& r);
 
bool
operator!=(const member_class_template_sptr& l,
       const member_class_template_sptr& r);
 
// Forward declarations for select nested hashers.
struct type_base::shared_ptr_hash
{
  size_t
  operator()(const shared_ptr<type_base> t) const;
};
 
struct type_base::dynamic_hash
{
  size_t
  operator()(const type_base* t) const;
};
 
/// A hashing functor for instances and pointers of @ref var_decl.
struct var_decl::hash
{
  size_t
  operator()(const var_decl& t) const;
 
  size_t
  operator()(const var_decl* t) const;
}; //end struct var_decl::hash
 
/// A comparison functor for pointers to @ref var_decl.
struct var_decl::ptr_equal
{
  /// Return true if the two instances of @ref var_decl are equal.
  ///
  /// @param l the first variable to compare.
  ///
  /// @param r the second variable to compare.
  ///
  /// @return true if @p l equals @p r.
  bool
  operator()(const var_decl* l, const var_decl* r) const
  {
    if (l == r)
      return true;
    if (!!l != !!r)
      return false;
    return (*l == *r);
  }
};// end struct var_decl::ptr_equal
 
/// A hashing functor fo instances and pointers of @ref function_decl.
struct function_decl::hash
{
  size_t
  operator()(const function_decl& t) const;
 
  size_t
  operator()(const function_decl* t) const;
};//end struct function_decl::hash
 
/// Equality functor for instances of @ref function_decl
struct function_decl::ptr_equal
{
  /// Tests if two pointers to @ref function_decl are equal.
  ///
  /// @param l the first pointer to @ref function_decl to consider in
  /// the comparison.
  ///
  /// @param r the second pointer to @ref function_decl to consider in
  /// the comparison.
  ///
  /// @return true if the two functions @p l and @p r are equal, false
  /// otherwise.
  bool
  operator()(const function_decl* l, const function_decl* r) const
  {
    if (l == r)
      return true;
    if (!!l != !!r)
      return false;
    return (*l == *r);
  }
};// function_decl::ptr_equal
 
/// The hashing functor for class_decl::base_spec.
struct class_decl::base_spec::hash
{
  size_t
  operator()(const base_spec& t) const;
};
 
/// The hashing functor for member_base.
struct member_base::hash
{
  size_t
  operator()(const member_base& m) const;
};
 
/// The hashing functor for member_function_template.
struct member_function_template::hash
{
  size_t
  operator()(const member_function_template& t) const;
};
 
/// The hashing functor for member_class_template
struct member_class_template::hash
{
  size_t
  operator()(const member_class_template& t) const;
};
 
struct function_tdecl::hash
{
  size_t
  operator()(const function_tdecl& t) const;
};
 
struct function_tdecl::shared_ptr_hash
{
  size_t
  operator()(const shared_ptr<function_tdecl> f) const;
};
 
struct class_tdecl::hash
{
  size_t
  operator()(const class_tdecl& t) const;
};
 
struct class_tdecl::shared_ptr_hash
{
  size_t
  operator()(const shared_ptr<class_tdecl> t) const;
};
 
/// The base class for the visitor type hierarchy used for traversing
/// a translation unit.
///
/// Client code willing to get notified for a certain kind of node
/// during the IR traversal might want to define a visitor class that
/// inherit ir_node_visitor, overload the ir_node_visitor::visit_begin()
/// or ir_node_visitor::visit_end() method of its choice, and provide
/// and implementation for it.  If either
/// ir_node_visitor::visit_begin() or ir_node_visitor::visit_end()
/// return false, it means the traversal has to stop immediately after
/// the methods' return.  If the methods return true, it means the
/// traversal keeps going.
///
/// That new visitor class would then be passed to e.g,
/// translation_unit::traverse or to the traverse method of any type
/// where the traversal is supposed to start from.
class ir_node_visitor : public node_visitor_base
{
  struct priv;
  std::unique_ptr<priv> priv_;
 
public:
 
  ir_node_visitor();
 
  virtual ~ir_node_visitor();
 
  void allow_visiting_already_visited_type_node(bool);
  bool allow_visiting_already_visited_type_node() const;
  void mark_type_node_as_visited(type_base *);
  void forget_visited_type_nodes();
  bool type_node_has_been_visited(type_base*) const;
 
  virtual bool visit_begin(decl_base*);
  virtual bool visit_end(decl_base*);
 
  virtual bool visit_begin(scope_decl*);
  virtual bool visit_end(scope_decl*);
 
  virtual bool visit_begin(type_base*);
  virtual bool visit_end(type_base*);
 
  virtual bool visit_begin(scope_type_decl*);
  virtual bool visit_end(scope_type_decl*);
 
  virtual bool visit_begin(type_decl*);
  virtual bool visit_end(type_decl*);
 
  virtual bool visit_begin(namespace_decl*);
  virtual bool visit_end(namespace_decl*);
 
  virtual bool visit_begin(qualified_type_def*);
  virtual bool visit_end(qualified_type_def*);
 
  virtual bool visit_begin(pointer_type_def*);
  virtual bool visit_end(pointer_type_def*);
 
  virtual bool visit_begin(reference_type_def*);
  virtual bool visit_end(reference_type_def*);
 
  virtual bool visit_begin(array_type_def*);
  virtual bool visit_end(array_type_def*);
 
  virtual bool visit_begin(array_type_def::subrange_type*);
  virtual bool visit_end(array_type_def::subrange_type*);
 
  virtual bool visit_begin(enum_type_decl*);
  virtual bool visit_end(enum_type_decl*);
 
  virtual bool visit_begin(typedef_decl*);
  virtual bool visit_end(typedef_decl*);
 
  virtual bool visit_begin(function_type*);
  virtual bool visit_end(function_type*);
 
  virtual bool visit_begin(var_decl*);
  virtual bool visit_end(var_decl*);
 
  virtual bool visit_begin(function_decl*);
  virtual bool visit_end(function_decl*);
 
  virtual bool visit_begin(function_decl::parameter*);
  virtual bool visit_end(function_decl::parameter*);
 
  virtual bool visit_begin(function_tdecl*);
  virtual bool visit_end(function_tdecl*);
 
  virtual bool visit_begin(class_tdecl*);
  virtual bool visit_end(class_tdecl*);
 
  virtual bool visit_begin(class_or_union *);
  virtual bool visit_end(class_or_union *);
 
  virtual bool visit_begin(class_decl*);
  virtual bool visit_end(class_decl*);
 
  virtual bool visit_begin(union_decl*);
  virtual bool visit_end(union_decl*);
 
  virtual bool visit_begin(class_decl::base_spec*);
  virtual bool visit_end(class_decl::base_spec*);
 
  virtual bool visit_begin(member_function_template*);
  virtual bool visit_end(member_function_template*);
 
  virtual bool visit_begin(member_class_template*);
  virtual bool visit_end(member_class_template*);
}; // end struct ir_node_visitor
 
// Debugging facility
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);
 
}// end namespace ir
} // end namespace abigail
#endif // __ABG_IR_H__