rtti.h

Go to the documentation of this file.

// Copyright (C) 2000, 2002, 2003, 2004, 2006 Free Software Foundation, Inc.
//
// This file is part of GCC.
//
// GCC is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2, or (at your option)
// any later version.
// GCC is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with GCC; see the file COPYING.  If not, write to
// the Free Software Foundation, 51 Franklin Street, Fifth Floor,
// Boston, MA 02110-1301, USA.
//
// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
//
// Written by Nathan Sidwell, Codesourcery LLC, <nathan@codesourcery.com>
#ifndef __RTTI_H
#define __RTTI_H

#include <typeinfo>

namespace __cxxabiv1
{
  // Type information for int, float etc.
  class __fundamental_type_info : public std::type_info
  {
  public:
    explicit
    __fundamental_type_info(const char* __n) : std::type_info(__n) { }

    virtual
    ~__fundamental_type_info();
  };

  // Type information for array objects.
  class __array_type_info : public std::type_info
  {
  public:
    explicit
    __array_type_info(const char* __n) : std::type_info(__n) { }

    virtual
    ~__array_type_info();
  };

  // Type information for functions (both member and non-member).
  class __function_type_info : public std::type_info
  {
  public:
    explicit
    __function_type_info(const char* __n) : std::type_info(__n) { }

    virtual
    ~__function_type_info();

  protected:
    // Implementation defined member function.
    virtual bool
    __is_function_p() const;
  };

  // Type information for enumerations.
  class __enum_type_info : public std::type_info
  {
  public:
    explicit
    __enum_type_info(const char* __n) : std::type_info(__n) { }

    virtual
    ~__enum_type_info();
  };

  // Common type information for simple pointers and pointers to member.
  class __pbase_type_info : public std::type_info
  {
  public:
    unsigned int        __flags; // Qualification of the target object.
    const std::type_info*   __pointee; // Type of pointed to object.

    explicit
    __pbase_type_info(const char* __n, int __quals,
              const std::type_info* __type)
    : std::type_info(__n), __flags(__quals), __pointee(__type)
    { }

    virtual
    ~__pbase_type_info();

    // Implementation defined type.
    enum __masks
      {
    __const_mask = 0x1,
    __volatile_mask = 0x2,
    __restrict_mask = 0x4,
    __incomplete_mask = 0x8,
    __incomplete_class_mask = 0x10
      };

  protected:
    __pbase_type_info(const __pbase_type_info&);

    __pbase_type_info&
    operator=(const __pbase_type_info&);

    // Implementation defined member functions.
    virtual bool
    __do_catch(const std::type_info* __thr_type, void** __thr_obj,
           unsigned int __outer) const;

    inline virtual bool
    __pointer_catch(const __pbase_type_info* __thr_type, void** __thr_obj,
            unsigned __outer) const;
  };

  // Type information for simple pointers.
  class __pointer_type_info : public __pbase_type_info
  {
  public:
    explicit
    __pointer_type_info(const char* __n, int __quals,
            const std::type_info* __type)
    : __pbase_type_info (__n, __quals, __type) { }


    virtual
    ~__pointer_type_info();

  protected:
    // Implementation defined member functions.
    virtual bool
    __is_pointer_p() const;

    virtual bool
    __pointer_catch(const __pbase_type_info* __thr_type, void** __thr_obj,
            unsigned __outer) const;
  };

  class __class_type_info;

  // Type information for a pointer to member variable.
  class __pointer_to_member_type_info : public __pbase_type_info
  {
  public:
    __class_type_info* __context;   // Class of the member.

    explicit
    __pointer_to_member_type_info(const char* __n, int __quals,
                  const std::type_info* __type,
                  __class_type_info* __klass)
    : __pbase_type_info(__n, __quals, __type), __context(__klass) { }

    virtual
    ~__pointer_to_member_type_info();

  protected:
    __pointer_to_member_type_info(const __pointer_to_member_type_info&);

    __pointer_to_member_type_info&
    operator=(const __pointer_to_member_type_info&);

    // Implementation defined member function.
    virtual bool
    __pointer_catch(const __pbase_type_info* __thr_type, void** __thr_obj,
            unsigned __outer) const;
  };

  // Helper class for __vmi_class_type.
  class __base_class_type_info
  {
  public:
    const __class_type_info*    __base_type;  // Base class type.
    long            __offset_flags;  // Offset and info.

    enum __offset_flags_masks
      {
    __virtual_mask = 0x1,
    __public_mask = 0x2,
    __hwm_bit = 2,
    __offset_shift = 8          // Bits to shift offset.
      };

    // Implementation defined member functions.
    bool
    __is_virtual_p() const
    { return __offset_flags & __virtual_mask; }

    bool
    __is_public_p() const
    { return __offset_flags & __public_mask; }

    ptrdiff_t
    __offset() const
    {
      // This shift, being of a signed type, is implementation
      // defined. GCC implements such shifts as arithmetic, which is
      // what we want.
      return static_cast<ptrdiff_t>(__offset_flags) >> __offset_shift;
    }
  };

  // Type information for a class.
  class __class_type_info : public std::type_info
  {
  public:
    explicit
    __class_type_info (const char *__n) : type_info(__n) { }

    virtual
    ~__class_type_info ();

    // Implementation defined types.
    // The type sub_kind tells us about how a base object is contained
    // within a derived object. We often do this lazily, hence the
    // UNKNOWN value. At other times we may use NOT_CONTAINED to mean
    // not publicly contained.
    enum __sub_kind
      {
    // We have no idea.
    __unknown = 0,

    // Not contained within us (in some circumstances this might
    // mean not contained publicly)
    __not_contained,

    // Contained ambiguously.
    __contained_ambig,

    // Via a virtual path.
    __contained_virtual_mask = __base_class_type_info::__virtual_mask,

    // Via a public path.
    __contained_public_mask = __base_class_type_info::__public_mask,

    // Contained within us.
    __contained_mask = 1 << __base_class_type_info::__hwm_bit,

    __contained_private = __contained_mask,
    __contained_public = __contained_mask | __contained_public_mask
      };

    struct __upcast_result;
    struct __dyncast_result;

  protected:
    // Implementation defined member functions.
    virtual bool
    __do_upcast(const __class_type_info* __dst_type, void**__obj_ptr) const;

    virtual bool
    __do_catch(const type_info* __thr_type, void** __thr_obj,
           unsigned __outer) const;

  public:
    // Helper for upcast. See if DST is us, or one of our bases.
    // Return false if not found, true if found.
    virtual bool
    __do_upcast(const __class_type_info* __dst, const void* __obj,
        __upcast_result& __restrict __result) const;

    // Indicate whether SRC_PTR of type SRC_TYPE is contained publicly
    // within OBJ_PTR. OBJ_PTR points to a base object of our type,
    // which is the destination type. SRC2DST indicates how SRC
    // objects might be contained within this type.  If SRC_PTR is one
    // of our SRC_TYPE bases, indicate the virtuality. Returns
    // not_contained for non containment or private containment.
    inline __sub_kind
    __find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr,
              const __class_type_info* __src_type,
              const void* __src_ptr) const;

    // Helper for dynamic cast. ACCESS_PATH gives the access from the
    // most derived object to this base. DST_TYPE indicates the
    // desired type we want. OBJ_PTR points to a base of our type
    // within the complete object. SRC_TYPE indicates the static type
    // started from and SRC_PTR points to that base within the most
    // derived object. Fill in RESULT with what we find. Return true
    // if we have located an ambiguous match.
    virtual bool
    __do_dyncast(ptrdiff_t __src2dst, __sub_kind __access_path,
         const __class_type_info* __dst_type, const void* __obj_ptr,
         const __class_type_info* __src_type, const void* __src_ptr,
         __dyncast_result& __result) const;

    // Helper for find_public_subobj. SRC2DST indicates how SRC_TYPE
    // bases are inherited by the type started from -- which is not
    // necessarily the current type. The current type will be a base
    // of the destination type.  OBJ_PTR points to the current base.
    virtual __sub_kind
    __do_find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr,
             const __class_type_info* __src_type,
             const void* __src_ptr) const;
  };

  // Type information for a class with a single non-virtual base.
  class __si_class_type_info : public __class_type_info
  {
  public:
    const __class_type_info* __base_type;

    explicit
    __si_class_type_info(const char *__n, const __class_type_info *__base)
    : __class_type_info(__n), __base_type(__base) { }

    virtual
    ~__si_class_type_info();

  protected:
    __si_class_type_info(const __si_class_type_info&);

    __si_class_type_info&
    operator=(const __si_class_type_info&);

    // Implementation defined member functions.
    virtual bool
    __do_dyncast(ptrdiff_t __src2dst, __sub_kind __access_path,
         const __class_type_info* __dst_type, const void* __obj_ptr,
         const __class_type_info* __src_type, const void* __src_ptr,
         __dyncast_result& __result) const;

    virtual __sub_kind
    __do_find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr,
             const __class_type_info* __src_type,
             const void* __sub_ptr) const;

    virtual bool
    __do_upcast(const __class_type_info*__dst, const void*__obj,
        __upcast_result& __restrict __result) const;
  };

  // Type information for a class with multiple and/or virtual bases.
  class __vmi_class_type_info : public __class_type_info
  {
  public:
    unsigned int        __flags;  // Details about the class hierarchy.
    unsigned int        __base_count;  // Number of direct bases.

    // The array of bases uses the trailing array struct hack so this
    // class is not constructable with a normal constructor. It is
    // internally generated by the compiler.
    __base_class_type_info  __base_info[1];  // Array of bases.

    explicit
    __vmi_class_type_info(const char* __n, int ___flags)
    : __class_type_info(__n), __flags(___flags), __base_count(0) { }

    virtual
    ~__vmi_class_type_info();

    // Implementation defined types.
    enum __flags_masks
      {
    __non_diamond_repeat_mask = 0x1, // Distinct instance of repeated base.
    __diamond_shaped_mask = 0x2, // Diamond shaped multiple inheritance.
    __flags_unknown_mask = 0x10
      };

  protected:
    // Implementation defined member functions.
    virtual bool
    __do_dyncast(ptrdiff_t __src2dst, __sub_kind __access_path,
         const __class_type_info* __dst_type, const void* __obj_ptr,
         const __class_type_info* __src_type, const void* __src_ptr,
         __dyncast_result& __result) const;

    virtual __sub_kind
    __do_find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr,
             const __class_type_info* __src_type,
             const void* __src_ptr) const;

    virtual bool
    __do_upcast(const __class_type_info* __dst, const void* __obj,
        __upcast_result& __restrict __result) const;
  };

  // Dynamic cast runtime.
  // src2dst has the following possible values
  //  >-1: src_type is a unique public non-virtual base of dst_type
  //       dst_ptr + src2dst == src_ptr
  //   -1: unspecified relationship
  //   -2: src_type is not a public base of dst_type
  //   -3: src_type is a multiple public non-virtual base of dst_type
  extern "C" void*
  __dynamic_cast(const void* __src_ptr, // Starting object.
         const __class_type_info* __src_type, // Static type of object.
         const __class_type_info* __dst_type, // Desired target type.
         ptrdiff_t __src2dst); // How src and dst are related.


  // Returns the type_info for the currently handled exception [15.3/8], or
  // null if there is none.
  extern "C" std::type_info*
  __cxa_current_exception_type();
} // namespace __cxxabiv1

// User programs should use the alias `abi'.
namespace abi = __cxxabiv1;


#endif // __RTTI_H