gcc/libstdc++-v3/libsupc++/typeinfo

// RTTI support for -*- C++ -*-
// Copyright (C) 1994, 1995, 1996, 1997, 1998, 2000 Free Software Foundation

// This file is part of GNU CC.
//
// GNU CC 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.
// 
// GNU CC 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 GNU CC; see the file COPYING.  If not, write to
// the Free Software Foundation, 59 Temple Place - Suite 330,
// Boston, MA 02111-1307, 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.

// __GXX_ABI_VERSION distinguishes the ABI that is being used. Values <100
// indicate the `old' abi, which grew as C++ was defined. Values >=100
// indicate the `new' abi, which is a cross vendor C++ abi, documented at
// `http://reality.sgi.com/dehnert_engr/cxx/'.

#ifndef __TYPEINFO__
#define __TYPEINFO__

#pragma interface "typeinfo"

#include <exception>

extern "C++" {

#if defined(__GXX_ABI_VERSION) && __GXX_ABI_VERSION >= 100
namespace __cxxabiv1
{
  class __class_type_info;
} // namespace __cxxabiv1
#endif

namespace std 
{
  class type_info 
  {
  public:
    // Destructor. Being the first non-inline virtual function, this
    // controls in which translation unit the vtable is emitted. The
    // compiler makes use of that information to know where to emit
    // the runtime-mandated type_info structures in the new-abi.
    virtual ~type_info();

  private:
    // Assigning type_info is not supported.  made private.
    type_info& operator=(const type_info&);
    type_info(const type_info&);
    
  protected:
    const char *__name;
    
  protected:
    explicit type_info(const char *__n): __name(__n) { }
    
  public:
    // the public interface
#if !defined(__GXX_ABI_VERSION) || __GXX_ABI_VERSION < 100
    // In old abi, there can be multiple instances of a type_info
    // object for one type. Uniqueness must use the _name value, not
    // object address.
    bool before(const type_info& arg) const;
    const char* name() const
    { return __name; }
    bool operator==(const type_info& __arg) const;
    bool operator!=(const type_info& __arg) const
    { return !operator==(__arg); }

#else
    // In new abi we can rely on type_info's NTBS being unique,
    // and therefore address comparisons are sufficient.
    bool before(const type_info& __arg) const
    { return __name < __arg.__name; }
    const char* name() const
    { return __name; }
    bool operator==(const type_info& __arg) const
    { return __name == __arg.__name; }
    bool operator!=(const type_info& __arg) const
    { return !operator==(__arg); }
#endif
    
    // the internal interface
#if defined(__GXX_ABI_VERSION) && __GXX_ABI_VERSION >= 100
  public:
    // return true if this is a pointer type of some kind
    virtual bool __is_pointer_p() const;
    // return true if this is a function type
    virtual bool __is_function_p() const;

    // Try and catch a thrown type. Store an adjusted pointer to the
    // caught type in THR_OBJ. If THR_TYPE is not a pointer type, then
    // THR_OBJ points to the thrown object. If THR_TYPE is a pointer
    // type, then THR_OBJ is the pointer itself. OUTER indicates the
    // number of outer pointers, and whether they were const
    // qualified.
    virtual bool __do_catch(const type_info *__thr_type, void **__thr_obj,
			    unsigned __outer) const;

    // internally used during catch matching
    virtual bool __do_upcast(const __cxxabiv1::__class_type_info *__target,
			     void **__obj_ptr) const;
#endif
  };

  class bad_cast : public exception 
  {
  public:
    bad_cast() throw() { }
    virtual ~bad_cast() throw() { }
  };
  
  class bad_typeid : public exception 
  {
  public:
    bad_typeid () throw() { }
    virtual ~bad_typeid () throw() { }
  };
} // namespace std

} // extern "C++"
#endif