rtti

Nathan Sidwell nathan at codesourcery.com
Mon Jun 12 21:27:56 UTC 2000


Hi,
Here's G++'s cxxabi.h and related files for comments, and my findings
about action item 37. For those unfamiliar with gcc's runtime layout
here's what the files contain

typeinfo	class type_info declaration
cxxabi.h	the abi's support type_info classes and prototypes
vec.cc		the abi's vector new and delete helpers
tinfo.h		runtime header for tinfo.cc & tinfo2.cc
tinfo.cc	dynamic cast and catch matching routines
tinfo2.cc	abi's non-class type_info definitions

the latter 3 files contain a big #if for gcc's old and new abis. for the
new abi __GXX_ABI_VERSION will be 100. Also, gcc doesn't provide <cstddef>
(but it's part of the library), so std::size_t, std::ptrdiff_t aren't
available in the header files, hence the use of __SIZE_TYPE__ and
__PTRDIFF_TYPE__ in header files.

1) The class definitions in cxxabi.h have inconsistent names for the data
members. In some cases each field is prefixed with the shortened class
name (for instance __vmi_class_type_info::vmi_offset_flags), in other
cases the abi doc doesn't specify a name, and there is no prefix (eg
__pbase_type_info:::quals). My preference is for non-prefixed names,
as that is a more usual in C++ (after all, we've had structure scope
for a long time). We should use a consistent naming scheme, and I'd
prefer it to be the non-prefixed form.

2) As to the usefulness of __vmi_class_type_info::non_public_base_mask
and __vmi_class_type_info::public_base_mask. It transpired that neither
were useful. there were two places where public_base_mask might be used,
but I suspect that to be premature optimization. non_public_base_mask
turned out to not be useful. In all cases of considering a non-public
base, one already knew the base was non-public, and the
non_diamond_repeat_mask and diamond_shaped_mask were useful. Therefore,
in resolution of item 37 I propose removing both non_public_base_mask
and public_base_mask from the vmi_flags.

nathan

-- 
Dr Nathan Sidwell   ::   http://www.codesourcery.com   ::   CodeSourcery LLC
         'But that's a lie.' - 'Yes it is. What's your point?'
nathan at codesourcery.com : http://www.cs.bris.ac.uk/~nathan/ : nathan at acm.org
-------------- next part --------------
/* new abi support -*- C++ -*-
   Copyright (C) 2000
   Free Software Foundation, Inc.
   Written by Nathan Sidwell, Codesourcery LLC, <nathan at codesourcery.com>  */

// 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.

/* This file declares the new abi entry points into the runtime. It is not
   normally necessary for user programs to include this header, or use the
   entry points directly. However, this header is available should that be
   needed.
   
   Some of the entry points are intended for both C and C++, thus this header
   is includable from both C and C++. Though the C++ specific parts are not
   available in C, naturally enough.  */

#ifndef __CXXABI_H
#define __CXXABI_H 1

#if defined(__cplusplus) && (!defined(__GXX_ABI_VERSION) || __GXX_ABI_VERSION < 100)
/* These structures only make sense when targeting the new abi, catch a
   bonehead error early rather than let the user get very confused.  */
#error "Not targetting the new abi, supply -fnew-abi"
#endif

#ifdef __cplusplus

// We use the compiler builtins __SIZE_TYPE__ and __PTRDIFF_TYPE__ instead of
// std::size_t and std::ptrdiff_t respectively. This makes us independant of
// the conformance level of <cstddef> and whether -fhonor-std was supplied.
// <cstddef> is not currently available during compiler building anyway.
// Including <stddef.h> would be wrong, as that would rudely place size_t in
// the global namespace.

#include <typeinfo>

namespace __cxxabiv1
{

/* type information for int, float etc */
class __fundamental_type_info
  : public std::type_info
{
public:
  virtual ~__fundamental_type_info ();
public:
  explicit __fundamental_type_info (const char *__n)
    : std::type_info (__n)
    { }
};

/* type information for array objects */
class __array_type_info
  : public std::type_info
{
/* abi defined member functions */
protected:
  virtual ~__array_type_info ();
public:
  explicit __array_type_info (const char *__n)
    : std::type_info (__n)
    { }
};

/* type information for functions (both member and non-member) */
class __function_type_info
  : public std::type_info
{
/* abi defined member functions */
public:
  virtual ~__function_type_info ();
public:
  explicit __function_type_info (const char *__n)
    : std::type_info (__n)
    { }
  
/* implementation defined member functions */
protected:
  virtual bool __is_function_p () const;
};

/* type information for enumerations */
class __enum_type_info
  : public std::type_info
{
/* abi defined member functions */
public:
  virtual ~__enum_type_info ();
public:
  explicit __enum_type_info (const char *__n)
    : std::type_info (__n)
    { }
};

/* common type information for simple pointers and pointers to member */
class __pbase_type_info
  : public std::type_info
{
/* abi defined member variables */
public:
  int quals;                    /* qualification of the target object */
  const std::type_info *type;   /* type of pointed to object */

/* abi defined member functions */
public:
  virtual ~__pbase_type_info ();
public:
  explicit __pbase_type_info (const char *__n,
                                int __quals,
                                const std::type_info *__type)
    : std::type_info (__n), quals (__quals), type (__type)
    { }

/* implementation defined types */
public:
  enum quals_masks {
    const_mask = 0x1,
    volatile_mask = 0x2,
    restrict_mask = 0x4,
    incomplete_mask = 0x8,
    incomplete_class_mask = 0x10
  };

/* implementation defined member functions */
protected:
  virtual bool __do_catch (const std::type_info *__thr_type,
                           void **__thr_obj,
                           unsigned __outer) const;
protected:
  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
{
/* abi defined member functions */
public:
  virtual ~__pointer_type_info ();
public:
  explicit __pointer_type_info (const char *__n,
                                int __quals,
                                const std::type_info *__type)
    : __pbase_type_info (__n, __quals, __type)
    { }

/* implementation defined member functions */
protected:
  virtual bool __is_pointer_p () const;

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

/* type information for a pointer to member variable */
class __pointer_to_member_type_info
  : public __pbase_type_info
{
/* abi defined member variables */
public:
  const __class_type_info *klass;   /* class of the member */

/* abi defined member functions */
public:
  virtual ~__pointer_to_member_type_info ();
public:
  explicit __pointer_to_member_type_info (const char *__n,
                                          int __quals,
                                          const std::type_info *__type,
                                          const __class_type_info *__klass)
    : __pbase_type_info (__n, __quals, __type), klass (__klass)
    { }

/* implementation defined member functions */
protected:
  virtual bool __pointer_catch (const __pbase_type_info *__thr_type,
                                void **__thr_obj,
                                unsigned __outer) const;
};

class __class_type_info;

/* helper class for __vmi_class_type */
class __base_class_info
{
/* abi defined member variables */
public:
  const __class_type_info *base;    /* base class type */
  long vmi_offset_flags;            /* offset and info */

/* implementation defined types */
public:
  enum vmi_masks {
    virtual_mask = 0x1,
    public_mask = 0x2,
    hwm_bit = 2,
    offset_shift = 8          /* bits to shift offset by */
  };
  
/* implementation defined member functions */
public:
  bool __is_virtual_p () const
    { return vmi_offset_flags & virtual_mask; }
  bool __is_public_p () const
    { return vmi_offset_flags & public_mask; }
  __PTRDIFF_TYPE__ __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_TYPE__> (vmi_offset_flags) >> offset_shift;
    }
};

/* type information for a class */
class __class_type_info
  : public std::type_info
{
/* abi defined member functions */
public:
  virtual ~__class_type_info ();
public:
  explicit __class_type_info (const char *__n)
    : type_info (__n)
    { }

/* implementation defined types */
public:
  /* 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
  {
    __unknown = 0,              /* we have no idea */
    __not_contained,            /* not contained within us (in some */
                                /* circumstances this might mean not contained */
                                /* publicly) */
    __contained_ambig,          /* contained ambiguously */
    
    __contained_virtual_mask = __base_class_info::virtual_mask, /* via a virtual path */
    __contained_public_mask = __base_class_info::public_mask,   /* via a public path */
    __contained_mask = 1 << __base_class_info::hwm_bit,         /* contained within us */
    
    __contained_private = __contained_mask,
    __contained_public = __contained_mask | __contained_public_mask
  };

public:  
  struct __upcast_result;
  struct __dyncast_result;

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

protected:
  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;

public:
  /* 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_TYPE__ __src2dst,
                                       const void *__obj_ptr,
                                       const __class_type_info *__src_type,
                                       const void *__src_ptr) const;

public:
  /* dynamic cast helper. 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_TYPE__ __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;
public:
  /* 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_TYPE__ __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
{
/* abi defined member variables */
protected:
  const __class_type_info *base;    /* base type */

/* abi defined member functions */
public:
  virtual ~__si_class_type_info ();
public:
  explicit __si_class_type_info (const char *__n,
                                 const __class_type_info *__base)
    : __class_type_info (__n), base (__base)
    { }

/* implementation defined member functions */
protected:
  virtual bool __do_dyncast (__PTRDIFF_TYPE__ __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_TYPE__ __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 {
/* abi defined member variables */
public:
  int vmi_flags;                  /* details about the class heirarchy */
  int vmi_base_count;             /* number of direct bases */
  __base_class_info vmi_bases[1]; /* array of 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. */

/* abi defined member functions */
public:
  virtual ~__vmi_class_type_info ();
public:
  explicit __vmi_class_type_info (const char *__n,
                                  int __flags)
    : __class_type_info (__n), vmi_flags (__flags), vmi_base_count (0)
    { }

/* implementation defined types */
public:
  enum vmi_flags_masks {
    non_diamond_repeat_mask = 0x1,   /* distinct instance of repeated base */
    diamond_shaped_mask = 0x2,       /* diamond shaped multiple inheritance */
    non_public_base_mask = 0x4,      /* has non-public direct or indirect base */
    public_base_mask = 0x8,          /* has public base (direct) */
    
    __flags_unknown_mask = 0x10
  };

/* implementation defined member functions */
protected:
  virtual bool __do_dyncast (__PTRDIFF_TYPE__ __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_TYPE__ __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 */
extern "C++"
void *__dynamic_cast (const void *__src_ptr,    /* object started from */
                      const __class_type_info *__src_type, /* static type of object */
                      const __class_type_info *__dst_type, /* desired target type */
                      __PTRDIFF_TYPE__ __src2dst); /* how src and dst are related */

    /* src2dst has the following possible values
       >= 0: 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 */

/* array ctor/dtor routines */

/* allocate and construct array */
extern "C++"
void *__cxa_vec_new (__SIZE_TYPE__ __element_count,
                     __SIZE_TYPE__ __element_size,
                     __SIZE_TYPE__ __padding_size,
                     void (*__constructor) (void *),
                     void (*__destructor) (void *));

/* construct array */
extern "C++"
void __cxa_vec_ctor (void *__array_address,
                     __SIZE_TYPE__ __element_count,
                     __SIZE_TYPE__ __element_size,
                     void (*__constructor) (void *),
                     void (*__destructor) (void *));

/* destruct array */
extern "C++"
void __cxa_vec_dtor (void *__array_address,
                     __SIZE_TYPE__ __element_count,
                     __SIZE_TYPE__ __element_size,
                     void (*__destructor) (void *));

/* destruct and release array */
extern "C++"
void __cxa_vec_delete (void *__array_address,
                       __SIZE_TYPE__ __element_size,
                       __SIZE_TYPE__ __padding_size,
                       void (*__destructor) (void *));

} /* namespace __cxxabiv1 */

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

#else
#endif /* __cplusplus */


#endif /* __CXXABI_H */
-------------- next part --------------
// new abi support -*- C++ -*-
// Copyright (C) 2000
// Free Software Foundation, Inc.
// Written by Nathan Sidwell, Codesourcery LLC, <nathan at codesourcery.com>
// 
// 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.

#if defined(__GXX_ABI_VERSION) && __GXX_ABI_VERSION >= 100
#include <cxxabi.h>
#include <new>
#include <exception>

// Exception handling hook, to mark current exception as not caught --
// generally because we're about to rethrow it after some cleanup.
extern "C" void __uncatch_exception (void);

namespace __cxxabiv1
{

/* allocate and construct array */
extern "C++" void *
__cxa_vec_new (size_t element_count,
               size_t element_size,
               size_t padding_size,
               void (*constructor) (void *),
               void (*destructor) (void *))
{
  size_t size = element_count * element_size + padding_size;
  char *base = static_cast <char *> (operator new[] (size));
  
  if (padding_size)
    {
      base += padding_size;
      reinterpret_cast <size_t *> (base)[-1] = element_count;
    }
  try
    {
      __cxa_vec_ctor (base, element_count, element_size,
                      constructor, destructor);
    }
  catch (...)
    {
      // operator delete [] cannot throw, so no need to protect it
      operator delete[] (base - padding_size);
      throw;
    }
  return base;
}

/* construct array */
extern "C++" void
__cxa_vec_ctor (void *array_address,
                size_t element_count,
                size_t element_size,
                void (*constructor) (void *),
                void (*destructor) (void *))
{
  size_t ix = 0;
  char *ptr = static_cast <char *> (array_address);
  
  try
    {
      if (constructor)
        for (; ix != element_count; ix++, ptr += element_size)
          constructor (ptr);
    }
  catch (...)
    {
      __uncatch_exception ();
      __cxa_vec_dtor (array_address, ix, element_size, destructor);
      throw;
    }
}

/* destruct array */
extern "C++" void
__cxa_vec_dtor (void *array_address,
                size_t element_count,
                size_t element_size,
                void (*destructor) (void *))
{
  if (destructor)
    {
      char *ptr = static_cast <char *> (array_address);
      size_t ix = element_count;
      bool unwinding = std::uncaught_exception ();
      
      ptr += element_count * element_size;
      
      try
        {
          while (ix--)
            {
              ptr -= element_size;
              destructor (ptr);
            }
        }
      catch (...)
        {
          if (unwinding)
            // [except.ctor]/3 If a destructor called during stack unwinding
            // exists with an exception, terminate is called.
            std::terminate ();
          __uncatch_exception ();
          __cxa_vec_dtor (array_address, ix, element_size, destructor);
          throw;
        }
    }
}

/* destruct and release array */
extern "C++" void
__cxa_vec_delete (void *array_address,
                  size_t element_size,
                  size_t padding_size,
                  void (*destructor) (void *))
{
  char *base = static_cast <char *> (array_address);
  
  if (padding_size)
    {
      size_t element_count = reinterpret_cast <size_t *> (base)[-1];
      base -= padding_size;
      try
        {
          __cxa_vec_dtor (array_address, element_count, element_size,
                          destructor);
        }
      catch (...)
        {
          // operator delete [] cannot throw, so no need to protect it
          operator delete[] (base);
          throw;
        }
    }
  operator delete[] (base);
}

} // namespace __cxxabiv1

#endif // defined(__GXX_ABI_VERSION) && __GXX_ABI_VERSION >= 100
-------------- next part --------------
// Methods for type_info for -*- C++ -*- Run Time Type Identification.
// Copyright (C) 1994, 1996, 1998, 1999, 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.

#pragma implementation "typeinfo"

#include <stddef.h>
#include "tinfo.h"
#include "new"			// for placement new

// This file contains the minimal working set necessary to link with code
// that uses virtual functions and -frtti but does not actually use RTTI
// functionality.

std::type_info::
~type_info ()
{ }

#if !defined(__GXX_ABI_VERSION) || __GXX_ABI_VERSION < 100
// original (old) abi

namespace
{
// ADDR is a pointer to an object.  Convert it to a pointer to a base,
// using OFFSET.
inline void*
convert_to_base (void *addr, bool is_virtual, myint32 offset)
{
  if (!addr)
    return NULL;

  if (!is_virtual)
    return (char *) addr + offset;

  // Under the old ABI, the offset gives us the address of a pointer
  // to the virtual base.
  return *((void **) ((char *) addr + offset));
}

}

// We can't rely on common symbols being shared between shared objects.
bool std::type_info::
operator== (const std::type_info& arg) const
{
  return (&arg == this) || (__builtin_strcmp (name (), arg.name ()) == 0);
}

extern "C" void
__rtti_class (void *addr, const char *name,
	      const __class_type_info::base_info *bl, size_t bn)
{ new (addr) __class_type_info (name, bl, bn); }

extern "C" void
__rtti_si (void *addr, const char *n, const std::type_info *ti)
{
  new (addr) __si_type_info
    (n, static_cast <const __user_type_info &> (*ti));
}

extern "C" void
__rtti_user (void *addr, const char *name)
{ new (addr) __user_type_info (name); }

// Upcast for catch checking. OBJPTR points to the thrown object and might be
// NULL. Return 0 on failure, non-zero on success. Set *ADJPTR to adjusted
// object pointer.
int __user_type_info::
upcast (const type_info &target, void *objptr,
        void **adjptr) const
{
  upcast_result result;
  
  if (do_upcast (contained_public, target, objptr, result))
    return 0;
  *adjptr = result.target_obj;
  return contained_public_p (result.whole2target);
}

// Down or cross cast for dynamic_cast. OBJPTR points to the most derrived
// object, SUBPTR points to the static base object. Both must not be NULL.
// TARGET specifies the desired target type, SUBTYPE specifies the static
// type. Both must be defined. Returns adjusted object pointer on success,
// NULL on failure. [expr.dynamic.cast]/8 says 'unambiguous public base'. This
// itself is an ambiguous statement. We choose it to mean the base must be
// separately unambiguous and public, rather than unambiguous considering only
// public bases.
void *__user_type_info::
dyncast (int boff,
         const type_info &target, void *objptr,
         const type_info &subtype, void *subptr) const
{
  dyncast_result result;
  
  do_dyncast (boff, contained_public,
              target, objptr, subtype, subptr, result);
  if (!result.target_obj)
    return NULL;
  if (contained_public_p (result.target2sub))
    return result.target_obj;
  if (contained_public_p (sub_kind (result.whole2sub & result.whole2target)))
    // Found a valid cross cast
    return result.target_obj;
  if (contained_nonvirtual_p (result.whole2sub))
    // Found an invalid cross cast, which cannot also be a down cast
    return NULL;
  if (result.target2sub == unknown)
    result.target2sub = static_cast <const __user_type_info &> (target)
                        .find_public_subobj (boff, subtype,
                                             result.target_obj, subptr);
  if (contained_public_p (result.target2sub))
    // Found a valid down cast
    return result.target_obj;
  // Must be an invalid down cast, or the cross cast wasn't bettered
  return NULL;
}

// Catch cast helper. ACCESS_PATH is the access from the complete thrown
// object to this base. TARGET is the desired type we want to catch. OBJPTR
// points to this base within the throw object, it might be NULL. Fill in
// RESULT with what we find. Return true, should we determine catch must fail.
bool __user_type_info::
do_upcast (sub_kind access_path,
           const type_info &target, void *objptr,
           upcast_result &__restrict result) const
{
  if (*this == target)
    {
      result.target_obj = objptr;
      result.base_type = nonvirtual_base_type;
      result.whole2target = access_path;
      return contained_nonpublic_p (access_path);
    }
  return false;
}

// dynamic cast helper. ACCESS_PATH gives the access from the most derived
// object to this base. TARGET indicates the desired type we want. OBJPTR
// points to this base within the object. SUBTYPE indicates the static type
// started from and SUBPTR 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.
bool __user_type_info::
do_dyncast (int, sub_kind access_path,
            const type_info &target, void *objptr,
            const type_info &subtype, void *subptr,
            dyncast_result &__restrict result) const
{
  if (objptr == subptr && *this == subtype)
    {
      // The subobject we started from. Indicate how we are accessible from
      // the most derived object.
      result.whole2sub = access_path;
      return false;
    }
  if (*this == target)
    {
      result.target_obj = objptr;
      result.whole2target = access_path;
      result.target2sub = not_contained;
      return false;
    }
  return false;
}

// find_public_subobj helper. Return contained_public if we are the desired
// subtype. OBJPTR points to this base type, SUBPTR points to the desired base
// object.
__user_type_info::sub_kind __user_type_info::
do_find_public_subobj (int, const type_info &, void *objptr, void *subptr) const
{
  if (subptr == objptr)
    // Must be our type, as the pointers match.
    return contained_public;
  return not_contained;
}

// catch helper for single public inheritance types. See
// __user_type_info::do_upcast for semantics.
bool __si_type_info::
do_upcast (sub_kind access_path,
           const type_info &target, void *objptr,
           upcast_result &__restrict result) const
{
  if (*this == target)
    {
      result.target_obj = objptr;
      result.base_type = nonvirtual_base_type;
      result.whole2target = access_path;
      return contained_nonpublic_p (access_path);
    }
  return base.do_upcast (access_path, target, objptr, result);
}

// dynamic cast helper for single public inheritance types. See
// __user_type_info::do_dyncast for semantics. BOFF indicates how SUBTYPE
// types are inherited by TARGET types.
bool __si_type_info::
do_dyncast (int boff, sub_kind access_path,
            const type_info &target, void *objptr,
            const type_info &subtype, void *subptr,
            dyncast_result &__restrict result) const
{
  if (objptr == subptr && *this == subtype)
    {
      // The subobject we started from. Indicate how we are accessible from
      // the most derived object.
      result.whole2sub = access_path;
      return false;
    }
  if (*this == target)
    {
      result.target_obj = objptr;
      result.whole2target = access_path;
      if (boff >= 0)
        result.target2sub = ((char *)subptr - (char *)objptr) == boff
              ? contained_public : not_contained;
      else if (boff == -2)
        result.target2sub = not_contained;
      return false;
    }
  return base.do_dyncast (boff, access_path,
                          target, objptr, subtype, subptr, result);
}

// find_public_subobj helper. See __user_type_info::do_find_public_subobj or
// semantics. BOFF indicates how SUBTYPE types are inherited by the original
// target object.
__user_type_info::sub_kind __si_type_info::
do_find_public_subobj (int boff, const type_info &subtype, void *objptr, void *subptr) const
{
  if (subptr == objptr && subtype == *this)
    return contained_public;
  return base.do_find_public_subobj (boff, subtype, objptr, subptr);
}

// catch helper for multiple or non-public inheritance types. See
// __user_type_info::do_upcast for semantics.
bool __class_type_info::
do_upcast (sub_kind access_path,
           const type_info &target, void *objptr,
           upcast_result &__restrict result) const
{
  if (*this == target)
    {
      result.target_obj = objptr;
      result.base_type = nonvirtual_base_type;
      result.whole2target = access_path;
      return contained_nonpublic_p (access_path);
    }
  
  for (size_t i = n_bases; i--;)
    {
      upcast_result result2;
      void *p = objptr;
      sub_kind sub_access = access_path;
      p = convert_to_base (p, 
			   base_list[i].is_virtual,
			   base_list[i].offset);
      if (base_list[i].is_virtual)
	sub_access = sub_kind (sub_access | contained_virtual_mask);
      if (base_list[i].access != PUBLIC)
        sub_access = sub_kind (sub_access & ~contained_public_mask);
      if (base_list[i].base->do_upcast (sub_access, target, p, result2)
          && !contained_virtual_p (result2.whole2target))
        return true; // must fail
      if (result2.base_type)
        {
          if (result2.base_type == nonvirtual_base_type
              && base_list[i].is_virtual)
            result2.base_type = base_list[i].base;
          if (!result.base_type)
            result = result2;
          else if (result.target_obj != result2.target_obj)
            {
              // Found an ambiguity.
	      result.target_obj = NULL;
	      result.whole2target = contained_ambig;
	      return true;
            }
          else if (result.target_obj)
            {
              // Ok, found real object via a virtual path.
              result.whole2target
                  = sub_kind (result.whole2target | result2.whole2target);
            }
          else
            {
              // Dealing with a null pointer, need to check vbase
              // containing each of the two choices.
              if (result2.base_type == nonvirtual_base_type
                  || result.base_type == nonvirtual_base_type
                  || !(*result2.base_type == *result.base_type))
                {
                  // Already ambiguous, not virtual or via different virtuals.
                  // Cannot match.
                  result.whole2target = contained_ambig;
                  return true;
                }
              result.whole2target
                  = sub_kind (result.whole2target | result2.whole2target);
            }
        }
    }
  return false;
}

// dynamic cast helper for non-public or multiple inheritance types. See
// __user_type_info::do_dyncast for overall semantics.
// This is a big hairy function. Although the run-time behaviour of
// dynamic_cast is simple to describe, it gives rise to some non-obvious
// behaviour. We also desire to determine as early as possible any definite
// answer we can get. Because it is unknown what the run-time ratio of
// succeeding to failing dynamic casts is, we do not know in which direction
// to bias any optimizations. To that end we make no particular effort towards
// early fail answers or early success answers. Instead we try to minimize
// work by filling in things lazily (when we know we need the information),
// and opportunisticly take early success or failure results.
bool __class_type_info::
do_dyncast (int boff, sub_kind access_path,
            const type_info &target, void *objptr,
            const type_info &subtype, void *subptr,
            dyncast_result &__restrict result) const
{
  if (objptr == subptr && *this == subtype)
    {
      // The subobject we started from. Indicate how we are accessible from
      // the most derived object.
      result.whole2sub = access_path;
      return false;
    }
  if (*this == target)
    {
      result.target_obj = objptr;
      result.whole2target = access_path;
      if (boff >= 0)
        result.target2sub = ((char *)subptr - (char *)objptr) == boff
              ? contained_public : not_contained;
      else if (boff == -2)
        result.target2sub = not_contained;
      return false;
    }
  bool result_ambig = false;
  for (size_t i = n_bases; i--;)
    {
      dyncast_result result2;
      void *p;
      sub_kind sub_access = access_path;
      p = convert_to_base (objptr, 
			   base_list[i].is_virtual,
			   base_list[i].offset);
      if (base_list[i].is_virtual)
	sub_access = sub_kind (sub_access | contained_virtual_mask);
      if (base_list[i].access != PUBLIC)
        sub_access = sub_kind (sub_access & ~contained_public_mask);
      
      bool result2_ambig
          = base_list[i].base->do_dyncast (boff, sub_access,
                                           target, p, subtype, subptr, result2);
      result.whole2sub = sub_kind (result.whole2sub | result2.whole2sub);
      if (result2.target2sub == contained_public
          || result2.target2sub == contained_ambig)
        {
          result.target_obj = result2.target_obj;
          result.whole2target = result2.whole2target;
          result.target2sub = result2.target2sub;
          // Found a downcast which can't be bettered or an ambiguous downcast
          // which can't be disambiguated
          return result2_ambig;
        }
      
      if (!result_ambig && !result.target_obj)
        {
          // Not found anything yet.
          result.target_obj = result2.target_obj;
          result.whole2target = result2.whole2target;
          result_ambig = result2_ambig;
        }
      else if (result.target_obj && result.target_obj == result2.target_obj)
        {
          // Found at same address, must be via virtual.  Pick the most
          // accessible path.
          result.whole2target =
              sub_kind (result.whole2target | result2.whole2target);
        }
      else if ((result.target_obj && result2.target_obj)
               || (result_ambig && result2.target_obj)
               || (result2_ambig && result.target_obj))
        {
          // Found two different TARGET bases, or a valid one and a set of
          // ambiguous ones, must disambiguate. See whether SUBOBJ is
          // contained publicly within one of the non-ambiguous choices.
          // If it is in only one, then that's the choice. If it is in
          // both, then we're ambiguous and fail. If it is in neither,
          // we're ambiguous, but don't yet fail as we might later find a
          // third base which does contain SUBPTR.
        
          sub_kind new_sub_kind = result2.target2sub;
          sub_kind old_sub_kind = result.target2sub;
          
          if (contained_nonvirtual_p (result.whole2sub))
            {
              // We already found SUBOBJ as a non-virtual base of most
              // derived. Therefore if it is in either choice, it can only be
              // in one of them, and we will already know.
              if (old_sub_kind == unknown)
                old_sub_kind = not_contained;
              if (new_sub_kind == unknown)
                new_sub_kind = not_contained;
            }
          else
            {
              const __user_type_info &t =
                  static_cast <const __user_type_info &> (target);
              
              if (old_sub_kind >= not_contained)
                ;// already calculated
              else if (contained_nonvirtual_p (new_sub_kind))
                // Already found non-virtually inside the other choice,
                // cannot be in this.
                old_sub_kind = not_contained;
              else
                old_sub_kind = t.find_public_subobj (boff, subtype,
                                                     result.target_obj, subptr);
          
              if (new_sub_kind >= not_contained)
                ;// already calculated
              else if (contained_nonvirtual_p (old_sub_kind))
                // Already found non-virtually inside the other choice,
                // cannot be in this.
                new_sub_kind = not_contained;
              else
                new_sub_kind = t.find_public_subobj (boff, subtype,
                                                     result2.target_obj, subptr);
            }
          
          // Neither sub_kind can be contained_ambig -- we bail out early
          // when we find those.
          if (contained_p (sub_kind (new_sub_kind ^ old_sub_kind)))
            {
              // Only on one choice, not ambiguous.
              if (contained_p (new_sub_kind))
                {
                  // Only in new.
                  result.target_obj = result2.target_obj;
                  result.whole2target = result2.whole2target;
                  result_ambig = false;
                  old_sub_kind = new_sub_kind;
                }
              result.target2sub = old_sub_kind;
              if (result.target2sub == contained_public)
                return false; // Can't be an ambiguating downcast for later discovery.
            }
          else if (contained_p (sub_kind (new_sub_kind & old_sub_kind)))
            {
              // In both.
              result.target_obj = NULL;
              result.target2sub = contained_ambig;
              return true;  // Fail.
            }
          else
            {
              // In neither publicly, ambiguous for the moment, but keep
              // looking. It is possible that it was private in one or
              // both and therefore we should fail, but that's just tough.
              result.target_obj = NULL;
              result.target2sub = not_contained;
              result_ambig = true;
            }
        }
      
      if (result.whole2sub == contained_private)
        // We found SUBOBJ as a private non-virtual base, therefore all
        // cross casts will fail. We have already found a down cast, if
        // there is one.
        return result_ambig;
    }

  return result_ambig;
}

// find_public_subobj helper for non-public or multiple inheritance types. See
// __user_type_info::do_find_public_subobj for semantics. We make use of BOFF
// to prune the base class walk.
__user_type_info::sub_kind __class_type_info::
do_find_public_subobj (int boff, const type_info &subtype, void *objptr, void *subptr) const
{
  if (objptr == subptr && subtype == *this)
    return contained_public;
  
  for (size_t i = n_bases; i--;)
    {
      if (base_list[i].access != PUBLIC)
        continue; // Not public, can't be here.
      void *p;

      if (base_list[i].is_virtual && boff == -3)
	// Not a virtual base, so can't be here.
	continue;
      
      p = convert_to_base (objptr, 
			   base_list[i].is_virtual,
			   base_list[i].offset);

      sub_kind base_kind = base_list[i].base->do_find_public_subobj
                              (boff, subtype, p, subptr);
      if (contained_p (base_kind))
        {
          if (base_list[i].is_virtual)
            base_kind = sub_kind (base_kind | contained_virtual_mask);
          return base_kind;
        }
    }
  
  return not_contained;
}
#else
// new abi

namespace std {

// return true if this is a type_info for a pointer type
bool type_info::
__is_pointer_p () const
{
  return false;
}

// return true if this is a type_info for a function type
bool type_info::
__is_function_p () const
{
  return false;
}

// try and catch a thrown object.
bool type_info::
__do_catch (const type_info *thr_type, void **, unsigned) const
{
  return *this == *thr_type;
}

// upcast from this type to the target. __class_type_info will override
bool type_info::
__do_upcast (const abi::__class_type_info *, void **) const
{
  return false;
}

};

namespace {

using namespace std;
using namespace abi;

// initial part of a vtable, this structure is used with offsetof, so we don't
// have to keep alignments consistent manually.
struct vtable_prefix {
  ptrdiff_t whole_object;           // offset to most derived object
  const __class_type_info *whole_type;  // pointer to most derived type_info
  const void *origin;               // what a class's vptr points to
};

template <typename T>
inline const T *
adjust_pointer (const void *base, ptrdiff_t offset)
{
  return reinterpret_cast <const T *>
    (reinterpret_cast <const char *> (base) + offset);
}

// ADDR is a pointer to an object.  Convert it to a pointer to a base,
// using OFFSET. IS_VIRTUAL is true, if we are getting a virtual base.
inline void const *
convert_to_base (void const *addr, bool is_virtual, ptrdiff_t offset)
{
  if (is_virtual)
    {
      const void *vtable = *static_cast <const void *const *> (addr);
      
      offset = *adjust_pointer<ptrdiff_t> (vtable, offset);
    }

  return adjust_pointer<void> (addr, offset);
}

// some predicate functions for __class_type_info::__sub_kind
inline bool contained_p (__class_type_info::__sub_kind access_path)
{
  return access_path >= __class_type_info::__contained_mask;
}
inline bool public_p (__class_type_info::__sub_kind access_path)
{
  return access_path & __class_type_info::__contained_public_mask;
}
inline bool virtual_p (__class_type_info::__sub_kind access_path)
{
  return (access_path & __class_type_info::__contained_virtual_mask);
}
inline bool contained_public_p (__class_type_info::__sub_kind access_path)
{
  return ((access_path & __class_type_info::__contained_public)
          == __class_type_info::__contained_public);
}
inline bool contained_nonpublic_p (__class_type_info::__sub_kind access_path)
{
  return ((access_path & __class_type_info::__contained_public)
          == __class_type_info::__contained_mask);
}
inline bool contained_nonvirtual_p (__class_type_info::__sub_kind access_path)
{
  return ((access_path & (__class_type_info::__contained_mask
                          | __class_type_info::__contained_virtual_mask))
          == __class_type_info::__contained_mask);
}

static const __class_type_info *const nonvirtual_base_type =
    static_cast <const __class_type_info *> (0) + 1;

}; // namespace

namespace __cxxabiv1
{

__class_type_info::
~__class_type_info ()
{}

__si_class_type_info::
~__si_class_type_info ()
{}

__vmi_class_type_info::
~__vmi_class_type_info ()
{}

// __upcast_result is used to hold information during traversal of a class
// heirarchy when catch matching.
struct __class_type_info::__upcast_result
{
  const void *dst_ptr;        // pointer to caught object
  __sub_kind part2dst;        // path from current base to target
  int src_details;            // hints about the source type heirarchy
  const __class_type_info *base_type; // where we found the target,
                              // if in vbase the __class_type_info of vbase
                              // if a non-virtual base then 1
                              // else NULL
  public:
  __upcast_result (int d)
    :dst_ptr (NULL), part2dst (__unknown), src_details (d), base_type (NULL)
    {}
};

// __dyncast_result is used to hold information during traversal of a class
// heirarchy when dynamic casting.
struct __class_type_info::__dyncast_result
{
  const void *dst_ptr;        // pointer to target object or NULL
  __sub_kind whole2dst;       // path from most derived object to target
  __sub_kind whole2src;       // path from most derived object to sub object
  __sub_kind dst2src;         // path from target to sub object
  int whole_details;          // details of the whole class heirarchy
  
  public:
  __dyncast_result (int details_ = __vmi_class_type_info::__flags_unknown_mask)
    :dst_ptr (NULL), whole2dst (__unknown),
     whole2src (__unknown), dst2src (__unknown),
     whole_details (details_)
    {}
};

bool __class_type_info::
__do_catch (const type_info *thr_type,
            void **thr_obj,
            unsigned outer) const
{
  if (*this == *thr_type)
    return true;
  if (outer >= 4)
    // Neither `A' nor `A *'.
    return false;
  return thr_type->__do_upcast (this, thr_obj);
}

bool __class_type_info::
__do_upcast (const __class_type_info *dst_type,
             void **obj_ptr) const
{
  __upcast_result result (__vmi_class_type_info::__flags_unknown_mask);
  
  __do_upcast (dst_type, *obj_ptr, result);
  if (!contained_public_p (result.part2dst))
    return false;
  *obj_ptr = const_cast <void *> (result.dst_ptr);
  return true;
}

inline __class_type_info::__sub_kind __class_type_info::
__find_public_src (ptrdiff_t src2dst,
                   const void *obj_ptr,
                   const __class_type_info *src_type,
                   const void *src_ptr) const
{
  if (src2dst >= 0)
    return adjust_pointer <void> (obj_ptr, src2dst) == src_ptr
            ? __contained_public : __not_contained;
  if (src2dst == -2)
    return __not_contained;
  return __do_find_public_src (src2dst, obj_ptr, src_type, src_ptr);
}

__class_type_info::__sub_kind __class_type_info::
__do_find_public_src (ptrdiff_t,
                      const void *obj_ptr,
                      const __class_type_info *,
                      const void *src_ptr) const
{
  if (src_ptr == obj_ptr)
    // Must be our type, as the pointers match.
    return __contained_public;
  return __not_contained;
}

__class_type_info::__sub_kind __si_class_type_info::
__do_find_public_src (ptrdiff_t src2dst,
                      const void *obj_ptr,
                      const __class_type_info *src_type,
                      const void *src_ptr) const
{
  if (src_ptr == obj_ptr && *this == *src_type)
    return __contained_public;
  return base->__do_find_public_src (src2dst, obj_ptr, src_type, src_ptr);
}

__class_type_info::__sub_kind __vmi_class_type_info::
__do_find_public_src (ptrdiff_t src2dst,
                      const void *obj_ptr,
                      const __class_type_info *src_type,
                      const void *src_ptr) const
{
  if (obj_ptr == src_ptr && *this == *src_type)
    return __contained_public;
  
  for (size_t i = vmi_base_count; i--;)
    {
      if (!vmi_bases[i].__is_public_p ())
        continue; // Not public, can't be here.
      
      const void *base = obj_ptr;
      ptrdiff_t offset = vmi_bases[i].__offset ();
      bool is_virtual = vmi_bases[i].__is_virtual_p ();
      
      if (is_virtual)
        {
          if (src2dst == -3)
            continue; // Not a virtual base, so can't be here.
        }
      base = convert_to_base (base, is_virtual, offset);
      
      __sub_kind base_kind = vmi_bases[i].base->__do_find_public_src
                              (src2dst, base, src_type, src_ptr);
      if (contained_p (base_kind))
        {
          if (is_virtual)
            base_kind = __sub_kind (base_kind | __contained_virtual_mask);
          return base_kind;
        }
    }
  
  return __not_contained;
}

bool __class_type_info::
__do_dyncast (ptrdiff_t,
              __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 &__restrict result) const
{
  if (obj_ptr == src_ptr && *this == *src_type)
    {
      // The src object we started from. Indicate how we are accessible from
      // the most derived object.
      result.whole2src = access_path;
      return false;
    }
  if (*this == *dst_type)
    {
      result.dst_ptr = obj_ptr;
      result.whole2dst = access_path;
      result.dst2src = __not_contained;
      return false;
    }
  return false;
}

bool __si_class_type_info::
__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 &__restrict result) const
{
  if (*this == *dst_type)
    {
      result.dst_ptr = obj_ptr;
      result.whole2dst = access_path;
      if (src2dst >= 0)
        result.dst2src = adjust_pointer <void> (obj_ptr, src2dst) == src_ptr
              ? __contained_public : __not_contained;
      else if (src2dst == -2)
        result.dst2src = __not_contained;
      return false;
    }
  if (obj_ptr == src_ptr && *this == *src_type)
    {
      // The src object we started from. Indicate how we are accessible from
      // the most derived object.
      result.whole2src = access_path;
      return false;
    }
  return base->__do_dyncast (src2dst, access_path, dst_type, obj_ptr,
                             src_type, src_ptr, result);
}

// This is a big hairy function. Although the run-time behaviour of
// dynamic_cast is simple to describe, it gives rise to some non-obvious
// behaviour. We also desire to determine as early as possible any definite
// answer we can get. Because it is unknown what the run-time ratio of
// succeeding to failing dynamic casts is, we do not know in which direction
// to bias any optimizations. To that end we make no particular effort towards
// early fail answers or early success answers. Instead we try to minimize
// work by filling in things lazily (when we know we need the information),
// and opportunisticly take early success or failure results.
bool __vmi_class_type_info::
__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 &__restrict result) const
{
  if (result.whole_details & __flags_unknown_mask)
    result.whole_details = vmi_flags;
  
  if (obj_ptr == src_ptr && *this == *src_type)
    {
      // The src object we started from. Indicate how we are accessible from
      // the most derived object.
      result.whole2src = access_path;
      return false;
    }
  if (*this == *dst_type)
    {
      result.dst_ptr = obj_ptr;
      result.whole2dst = access_path;
      if (src2dst >= 0)
        result.dst2src = adjust_pointer <void> (obj_ptr, src2dst) == src_ptr
              ? __contained_public : __not_contained;
      else if (src2dst == -2)
        result.dst2src = __not_contained;
      return false;
    }

  bool result_ambig = false;
  for (size_t i = vmi_base_count; i--;)
    {
      __dyncast_result result2 (result.whole_details);
      void const *base = obj_ptr;
      __sub_kind base_access = access_path;
      ptrdiff_t offset = vmi_bases[i].__offset ();
      bool is_virtual = vmi_bases[i].__is_virtual_p ();
      
      if (is_virtual)
        base_access = __sub_kind (base_access | __contained_virtual_mask);
      base = convert_to_base (base, is_virtual, offset);

      if (!vmi_bases[i].__is_public_p ())
        {
          if (src2dst == -2 &&
              !(result.whole_details
                & (non_diamond_repeat_mask | diamond_shaped_mask)))
            // The hierarchy has no duplicate bases (which might ambiguate
            // things) and where we started is not a public base of what we
            // want (so it cannot be a downcast). There is nothing of interest
            // hiding in a non-public base.
            continue;
          base_access = __sub_kind (base_access & ~__contained_public_mask);
        }
      
      bool result2_ambig
          = vmi_bases[i].base->__do_dyncast (src2dst, base_access,
                                             dst_type, base,
                                             src_type, src_ptr, result2);
      result.whole2src = __sub_kind (result.whole2src | result2.whole2src);
      if (result2.dst2src == __contained_public
          || result2.dst2src == __contained_ambig)
        {
          result.dst_ptr = result2.dst_ptr;
          result.whole2dst = result2.whole2dst;
          result.dst2src = result2.dst2src;
          // Found a downcast which can't be bettered or an ambiguous downcast
          // which can't be disambiguated
          return result2_ambig;
        }
      
      if (!result_ambig && !result.dst_ptr)
        {
          // Not found anything yet.
          result.dst_ptr = result2.dst_ptr;
          result.whole2dst = result2.whole2dst;
          result_ambig = result2_ambig;
          if (result.dst_ptr && result.whole2src != __unknown
              && !(vmi_flags & non_diamond_repeat_mask))
            // Found dst and src and we don't have repeated bases.
            return result_ambig;
        }
      else if (result.dst_ptr && result.dst_ptr == result2.dst_ptr)
        {
          // Found at same address, must be via virtual.  Pick the most
          // accessible path.
          result.whole2dst =
              __sub_kind (result.whole2dst | result2.whole2dst);
        }
      else if ((result.dst_ptr != 0 | result_ambig)
               && (result2.dst_ptr != 0 | result2_ambig))
        {
          // Found two different DST_TYPE bases, or a valid one and a set of
          // ambiguous ones, must disambiguate. See whether SRC_PTR is
          // contained publicly within one of the non-ambiguous choices. If it
          // is in only one, then that's the choice. If it is in both, then
          // we're ambiguous and fail. If it is in neither, we're ambiguous,
          // but don't yet fail as we might later find a third base which does
          // contain SRC_PTR.
        
          __sub_kind new_sub_kind = result2.dst2src;
          __sub_kind old_sub_kind = result.dst2src;
          
          if (contained_p (result.whole2src)
              && (!virtual_p (result.whole2src)
                  || !(result.whole_details & diamond_shaped_mask)))
            {
              // We already found SRC_PTR as a base of most derived, and
              // either it was non-virtual, or the whole heirarchy is
              // not-diamond shaped. Therefore if it is in either choice, it
              // can only be in one of them, and we will already know.
              if (old_sub_kind == __unknown)
                old_sub_kind = __not_contained;
              if (new_sub_kind == __unknown)
                new_sub_kind = __not_contained;
            }
          else
            {
              if (old_sub_kind >= __not_contained)
                ;// already calculated
              else if (contained_p (new_sub_kind)
                       && (!virtual_p (new_sub_kind)
                           || !(vmi_flags & diamond_shaped_mask)))
                // Already found inside the other choice, and it was
                // non-virtual or we are not diamond shaped.
                old_sub_kind = __not_contained;
              else
                old_sub_kind = dst_type->__find_public_src
                                (src2dst, result.dst_ptr, src_type, src_ptr);
          
              if (new_sub_kind >= __not_contained)
                ;// already calculated
              else if (contained_p (old_sub_kind)
                       && (!virtual_p (old_sub_kind)
                           || !(vmi_flags & diamond_shaped_mask)))
                // Already found inside the other choice, and it was
                // non-virtual or we are not diamond shaped.
                new_sub_kind = __not_contained;
              else
                new_sub_kind = dst_type->__find_public_src
                                (src2dst, result2.dst_ptr, src_type, src_ptr);
            }
          
          // Neither sub_kind can be contained_ambig -- we bail out early
          // when we find those.
          if (contained_p (__sub_kind (new_sub_kind ^ old_sub_kind)))
            {
              // Only on one choice, not ambiguous.
              if (contained_p (new_sub_kind))
                {
                  // Only in new.
                  result.dst_ptr = result2.dst_ptr;
                  result.whole2dst = result2.whole2dst;
                  result_ambig = false;
                  old_sub_kind = new_sub_kind;
                }
              result.dst2src = old_sub_kind;
              if (public_p (result.dst2src))
                return false; // Can't be an ambiguating downcast for later discovery.
              if (!virtual_p (result.dst2src))
                return false; // Found non-virtually can't be bettered
            }
          else if (contained_p (__sub_kind (new_sub_kind & old_sub_kind)))
            {
              // In both.
              result.dst_ptr = NULL;
              result.dst2src = __contained_ambig;
              return true;  // Fail.
            }
          else
            {
              // In neither publicly, ambiguous for the moment, but keep
              // looking. It is possible that it was private in one or
              // both and therefore we should fail, but that's just tough.
              result.dst_ptr = NULL;
              result.dst2src = __not_contained;
              result_ambig = true;
            }
        }
      
      if (result.whole2src == __contained_private)
        // We found SRC_PTR as a private non-virtual base, therefore all
        // cross casts will fail. We have already found a down cast, if
        // there is one.
        return result_ambig;
    }

  return result_ambig;
}

bool __class_type_info::
__do_upcast (const __class_type_info *dst, const void *obj,
             __upcast_result &__restrict result) const
{
  if (*this == *dst)
    {
      result.dst_ptr = obj;
      result.base_type = nonvirtual_base_type;
      result.part2dst = __contained_public;
      return true;
    }
  return false;
}

bool __si_class_type_info::
__do_upcast (const __class_type_info *dst, const void *obj_ptr,
             __upcast_result &__restrict result) const
{
  if (__class_type_info::__do_upcast (dst, obj_ptr, result))
    return true;
  
  return base->__do_upcast (dst, obj_ptr, result);
}

bool __vmi_class_type_info::
__do_upcast (const __class_type_info *dst, const void *obj_ptr,
             __upcast_result &__restrict result) const
{
  if (__class_type_info::__do_upcast (dst, obj_ptr, result))
    return true;
  
  int src_details = result.src_details;
  if (src_details & __flags_unknown_mask)
    src_details = vmi_flags;
  
  for (size_t i = vmi_base_count; i--;)
    {
      __upcast_result result2 (src_details);
      const void *base = obj_ptr;
      ptrdiff_t offset = vmi_bases[i].__offset ();
      bool is_virtual = vmi_bases[i].__is_virtual_p ();
      bool is_public = vmi_bases[i].__is_public_p ();
      
      if (!is_public && !(src_details & non_diamond_repeat_mask))
        // original cannot have an ambiguous base, so skip private bases
        continue;

      if (base)
        base = convert_to_base (base, is_virtual, offset);
      
      if (vmi_bases[i].base->__do_upcast (dst, base, result2))
        {
          if (result2.base_type == nonvirtual_base_type && is_virtual)
            result2.base_type = vmi_bases[i].base;
          if (contained_p (result2.part2dst) && !is_public)
            result2.part2dst = __sub_kind (result2.part2dst & ~__contained_public_mask);
          
          if (!result.base_type)
            {
              result = result2;
              if (!contained_p (result.part2dst))
                return true; // found ambiguously
              
              if (result.part2dst & __contained_public_mask)
                {
                  if (!(vmi_flags & non_diamond_repeat_mask))
                    return true;  // cannot have an ambiguous other base
                }
              else
                {
                  if (!virtual_p (result.part2dst))
                    return true; // cannot have another path
                  if (!(vmi_flags & diamond_shaped_mask))
                    return true; // cannot have a more accessible path
                }
            }
          else if (result.dst_ptr != result2.dst_ptr)
            {
              // Found an ambiguity.
	      result.dst_ptr = NULL;
	      result.part2dst = __contained_ambig;
	      return true;
            }
          else if (result.dst_ptr)
            {
              // Ok, found real object via a virtual path.
              result.part2dst
                  = __sub_kind (result.part2dst | result2.part2dst);
            }
          else
            {
              // Dealing with a null pointer, need to check vbase
              // containing each of the two choices.
              if (result2.base_type == nonvirtual_base_type
                  || result.base_type == nonvirtual_base_type
                  || !(*result2.base_type == *result.base_type))
                {
                  // Already ambiguous, not virtual or via different virtuals.
                  // Cannot match.
                  result.part2dst = __contained_ambig;
                  return true;
                }
              result.part2dst
                  = __sub_kind (result.part2dst | result2.part2dst);
            }
        }
    }
  return result.part2dst != __unknown;
}

// this is the external interface to the dynamic cast machinery
extern "C++" void *
__dynamic_cast (const void *src_ptr,    // object started from
                const __class_type_info *src_type, // type of the starting object
                const __class_type_info *dst_type, // desired target type
                ptrdiff_t src2dst) // how src and dst are related
{
  const void *vtable = *static_cast <const void *const *> (src_ptr);
  const vtable_prefix *prefix =
      adjust_pointer <vtable_prefix> (vtable, 
				      -offsetof (vtable_prefix, origin));
  const void *whole_ptr =
      adjust_pointer <void> (src_ptr, prefix->whole_object);
  const __class_type_info *whole_type = prefix->whole_type;
  __class_type_info::__dyncast_result result;
  
  whole_type->__do_dyncast (src2dst, __class_type_info::__contained_public,
                            dst_type, whole_ptr, src_type, src_ptr, result);
  if (!result.dst_ptr)
    return NULL;
  if (contained_public_p (result.dst2src))
    // Src is known to be a public base of dst.
    return const_cast <void *> (result.dst_ptr);
  if (contained_public_p (__class_type_info::__sub_kind (result.whole2src & result.whole2dst)))
    // Both src and dst are known to be public bases of whole. Found a valid
    // cross cast.
    return const_cast <void *> (result.dst_ptr);
  if (contained_nonvirtual_p (result.whole2src))
    // Src is known to be a non-public nonvirtual base of whole, and not a
    // base of dst. Found an invalid cross cast, which cannot also be a down
    // cast
    return NULL;
  if (result.dst2src == __class_type_info::__unknown)
    result.dst2src = dst_type->__find_public_src (src2dst, result.dst_ptr,
                                                  src_type, src_ptr);
  if (contained_public_p (result.dst2src))
    // Found a valid down cast
    return const_cast <void *> (result.dst_ptr);
  // Must be an invalid down cast, or the cross cast wasn't bettered
  return NULL;
}

}; // namespace __cxxabiv1
#endif
-------------- next part --------------
// RTTI support internals for -*- C++ -*-
// Copyright (C) 1994, 1995, 1996, 1998, 1999, 2000 Free Software Foundation

#include "typeinfo"

// Class declarations shared between the typeinfo implementation files.

#if !defined(__GXX_ABI_VERSION) || __GXX_ABI_VERSION < 100
// original (old) abi

// type_info for a class with no base classes (or an enum).

struct __user_type_info : public std::type_info {
  __user_type_info (const char *n) : type_info (n) {}

  // If our type can be upcast to a public and unambiguous base, then return
  // non-zero and set RES to point to the base object. OBJ points to the throw
  // object and can be NULL, if there is no object to adjust.
  int upcast (const type_info &target, void *obj, void **res) const;
  
  // If our type can be dynamicly cast to the target type, then return
  // pointer to the target object. OBJ is the pointer to the most derived
  // type and cannot be NULL. SUBTYPE and SUBOBJ indicate the static type
  // base object from whence we came, it cannot be NULL. SUBTYPE cannot be
  // the same as TARGET. TARGET cannot be a base of SUBTYPE.
  // BOFF indicates how SUBTYPE is related to TARGET.
  // BOFF >= 0, there is only one public non-virtual SUBTYPE base at offset
  //    BOFF, and there are no public virtual SUBTYPE bases.
  //    Therefore check if SUBOBJ is at offset BOFF when we find a target
  // BOFF == -1, SUBTYPE occurs as multiple public virtual or non-virtual bases.
  //    Lazily search all the bases of TARGET.
  // BOFF == -2, SUBTYPE is not a public base.
  // BOFF == -3, SUBTYPE occurs as multiple public non-virtual bases.
  //    Lazily search the non-virtual bases of TARGET.
  // For backwards compatibility set BOFF to -1, that is the safe "unknown"
  // value. We do not care about SUBTYPES as private bases of TARGET, as they
  // can never succeed as downcasts, only as crosscasts -- and then only if
  // they are virtual. This is more complicated that it might seem.
  void *dyncast (int boff,
                 const type_info &target, void *obj,
                 const type_info &subtype, void *subobj) const;
  
  // non_virtual_base_type is used to indicate that a base class is via a
  // non-virtual access path.
  static const type_info *const nonvirtual_base_type
      = static_cast <const type_info *> (0) + 1;
  
  // 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
  {
    unknown = 0,              // we have no idea
    not_contained,            // not contained within us (in some
                              // circumstances this might mean not contained
                              // publicly)
    contained_ambig,          // contained ambiguously
    contained_mask = 4,       // contained within us
    contained_virtual_mask = 1, // via a virtual path
    contained_public_mask = 2,  // via a public path
    contained_private = contained_mask,
    contained_public = contained_mask | contained_public_mask
  };
  // some predicate functions for sub_kind
  static inline bool contained_p (sub_kind access_path)
  {
    return access_path >= contained_mask;
  }
  static inline bool contained_public_p (sub_kind access_path)
  {
    return access_path >= contained_public;
  }
  static inline bool contained_nonpublic_p (sub_kind access_path)
  {
    return (access_path & contained_public) == contained_mask;
  }
  static inline bool contained_nonvirtual_p (sub_kind access_path)
  {
    return (access_path & (contained_mask | contained_virtual_mask))
           == contained_mask;
  }
  static inline bool contained_virtual_p (sub_kind access_path)
  {
    return (access_path & (contained_mask | contained_virtual_mask))
           == (contained_mask | contained_virtual_mask);
  }
  
  struct upcast_result
  {
    void *target_obj;   // pointer to target object or NULL (init NULL)
    sub_kind whole2target;      // path from most derived object to target
    const type_info *base_type; // where we found the target, (init NULL)
                                // if in vbase the __user_type_info of vbase)
                                // if a non-virtual base then 1
                                // else NULL
    public:
    upcast_result ()
      :target_obj (NULL), whole2target (unknown), base_type (NULL)
      {}
  };
  struct dyncast_result
  {
    void *target_obj;   // pointer to target object or NULL (init NULL)
    sub_kind whole2target;      // path from most derived object to target
    sub_kind whole2sub;         // path from most derived object to sub object
    sub_kind target2sub;        // path from target to sub object
    
    public:
    dyncast_result ()
      :target_obj (NULL), whole2target (unknown),
       whole2sub (unknown), target2sub (unknown)
      {}
  };
  
  public:
  // Helper for upcast. See if TARGET is us, or one of our bases. ACCESS_PATH
  // gives the access from the start object. Return TRUE if we know the catch
  // fails.
  virtual bool do_upcast (sub_kind access_path,
                          const type_info &target, void *obj,
                          upcast_result &__restrict result) const;
  // Helper for dyncast. BOFF indicates how the SUBTYPE is related to TARGET.
  // ACCESS_PATH indicates the access from the most derived object.  It is
  // used to prune the DAG walk. All information about what we find is put
  // into RESULT. Return true, if the match we have found is ambiguous.
  virtual bool do_dyncast (int boff, sub_kind access_path,
                           const type_info &target, void *obj,
                           const type_info &subtype, void *subptr,
                           dyncast_result &__restrict result) const;
  public:
  // Indicate whether SUBPTR of type SUBTYPE is contained publicly within
  // OBJPTR. OBJPTR points to this base object. BOFF indicates how SUBTYPE
  // objects might be contained within this type.  If SUBPTR is one of our
  // SUBTYPE bases, indicate virtuality. Returns not_contained for non
  // containment or private containment.
  sub_kind find_public_subobj (int boff, const type_info &subtype,
                               void *objptr, void *subptr) const
  {
    if (boff >= 0)
      return ((char *)subptr - (char *)objptr) == boff
              ? contained_public : not_contained;
    if (boff == -2)
      return not_contained;
    return do_find_public_subobj (boff, subtype, objptr, subptr);
  }
  
  public:
  // Helper for find_subobj. BOFF indicates how SUBTYPE bases are inherited by
  // the type started from -- which is not necessarily the current type.
  // OBJPTR points to the current base.
  virtual sub_kind do_find_public_subobj (int boff, const type_info &subtype,
                                          void *objptr, void *subptr) const;
};

// type_info for a class with one public, nonvirtual base class.

class __si_type_info : public __user_type_info {
  const __user_type_info &base;

public:
  __si_type_info (const char *n, const __user_type_info &b)
    : __user_type_info (n), base (b) { }

  private:
  virtual bool do_upcast (sub_kind access_path,
                          const type_info &target, void *obj,
                          upcast_result &__restrict result) const;
  virtual bool do_dyncast (int boff, sub_kind access_path,
                           const type_info &target, void *obj,
                           const type_info &subtype, void *subptr,
                           dyncast_result &__restrict result) const;
  virtual sub_kind do_find_public_subobj (int boff, const type_info &subtype,
                                          void *objptr, void *subptr) const;
};

// type_info for a general class.

// Kludge, kludge, kludge.
#include "tconfig.h"

#if BITS_PER_UNIT == 8
typedef int myint32 __attribute__ ((mode (SI)));
#elif BITS_PER_UNIT == 16
typedef int myint32 __attribute__ ((mode (HI)));
#elif BITS_PER_UNIT == 32
typedef int myint32 __attribute__ ((mode (QI)));
#endif

struct __class_type_info : public __user_type_info {
  enum access { PUBLIC = 1, PROTECTED = 2, PRIVATE = 3 };

  struct base_info {
    const __user_type_info *base;
    myint32 offset: 29;
    bool is_virtual: 1;
    enum access access: 2;
  };

  const base_info *base_list;
  size_t n_bases;

  __class_type_info (const char *name, const base_info *bl, size_t bn)
    : __user_type_info (name), base_list (bl), n_bases (bn) {}

  public:
  virtual bool do_upcast (sub_kind access_path,
                          const type_info &target, void *obj,
                          upcast_result &__restrict result) const;
  virtual bool do_dyncast (int boff, sub_kind access_path,
                           const type_info &target, void *obj,
                           const type_info &subtype, void *subptr,
                           dyncast_result &__restrict result) const;
  virtual sub_kind do_find_public_subobj (int boff, const type_info &subtype,
                                          void *objptr, void *subptr) const;
};
#else
// new abi
#include <cxxabi.h>

#endif
-------------- next part --------------
// Methods for type_info for -*- C++ -*- Run Time Type Identification.
// Copyright (C) 1994, 1996, 1997, 1998, 1999, 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.

#include <stddef.h>
#include "tinfo.h"
#include "new"			// for placement new

// We can't rely on having stdlib.h if we're freestanding.
extern "C" void abort ();

using std::type_info;

#if !defined(__GXX_ABI_VERSION) || __GXX_ABI_VERSION < 100
bool
type_info::before (const type_info &arg) const
{
  return __builtin_strcmp (name (), arg.name ()) < 0;
}

// type info for pointer type.

struct __pointer_type_info : public type_info {
  const type_info& type;

  __pointer_type_info (const char *n, const type_info& ti)
    : type_info (n), type (ti) {}
};

// type info for attributes

struct __attr_type_info : public type_info {
  enum cv { NONE = 0, CONST = 1, VOLATILE = 2, CONSTVOL = 1 | 2 };

  const type_info& type;
  cv attr;

  __attr_type_info (const char *n, cv a, const type_info& t)
    : type_info (n), type (t), attr (a) {}
};

// type_info for builtin type

struct __builtin_type_info : public type_info {
  __builtin_type_info (const char *n): type_info (n) {}
};

// type info for function.

struct __func_type_info : public type_info {
  __func_type_info (const char *n) : type_info (n) {}
};

// type info for pointer to member function.

struct __ptmf_type_info : public type_info {
  __ptmf_type_info (const char *n) : type_info (n) {}
};

// type info for pointer to data member.

struct __ptmd_type_info : public type_info {
  __ptmd_type_info (const char *n): type_info (n) {}
};

// type info for array.

struct __array_type_info : public type_info {
  __array_type_info (const char *n): type_info (n) {}
};

#else

#include <cxxabi.h>
#endif

#if defined(__GXX_ABI_VERSION) && __GXX_ABI_VERSION >= 100
namespace __cxxabiv1 {

using namespace std;

// This has special meaning to the compiler, and will cause it
// to emit the type_info structures for the fundamental types which are
// mandated to exist in the runtime.
__fundamental_type_info::
~__fundamental_type_info ()
{}

__array_type_info::
~__array_type_info ()
{}

__function_type_info::
~__function_type_info ()
{}

__enum_type_info::
~__enum_type_info ()
{}

__pbase_type_info::
~__pbase_type_info ()
{}

__pointer_type_info::
~__pointer_type_info ()
{}

__pointer_to_member_type_info::
~__pointer_to_member_type_info ()
{}

bool __pointer_type_info::
__is_pointer_p () const
{
  return true;
}

bool __function_type_info::
__is_function_p () const
{
  return true;
}

bool __pbase_type_info::
__do_catch (const type_info *thr_type,
            void **thr_obj,
            unsigned outer) const
{
  if (*this == *thr_type)
    return true;      // same type
  if (typeid (*this) != typeid (*thr_type))
    return false;     // not both same kind of pointers
  
  if (!(outer & 1))
    // We're not the same and our outer pointers are not all const qualified
    // Therefore there must at least be a qualification conversion involved
    // But for that to be valid, our outer pointers must be const qualified.
    return false;
  
  const __pbase_type_info *thrown_type =
    static_cast <const __pbase_type_info *> (thr_type);
  
  if (thrown_type->quals & ~quals)
    // We're less qualified.
    return false;
  
  if (!(quals & const_mask))
    outer &= ~1;
  
  return __pointer_catch (thrown_type, thr_obj, outer);
}

inline bool __pbase_type_info::
__pointer_catch (const __pbase_type_info *thrown_type,
                 void **thr_obj,
                 unsigned outer) const
{
  return type->__do_catch (thrown_type->type, thr_obj, outer + 2);
}

bool __pointer_type_info::
__pointer_catch (const __pbase_type_info *thrown_type,
                 void **thr_obj,
                 unsigned outer) const
{
  if (outer < 2 && *type == typeid (void))
    {
      // conversion to void
      return !thrown_type->type->__is_function_p ();
    }
  
  return __pbase_type_info::__pointer_catch (thrown_type, thr_obj, outer);
}

bool __pointer_to_member_type_info::
__pointer_catch (const __pbase_type_info *thr_type,
                 void **thr_obj,
                 unsigned outer) const
{
  // This static cast is always valid, as our caller will have determined that
  // thr_type is really a __pointer_to_member_type_info.
  const __pointer_to_member_type_info *thrown_type =
    static_cast <const __pointer_to_member_type_info *> (thr_type);
  
  if (*klass != *thrown_type->klass)
    return false;     // not pointers to member of same class
  
  return __pbase_type_info::__pointer_catch (thrown_type, thr_obj, outer);
}

} // namespace std
#endif

// Entry points for the compiler.

/* Low level match routine used by compiler to match types of catch
   variables and thrown objects.  */

extern "C" int
__throw_type_match_rtti_2 (const void *catch_type_r, const void *throw_type_r,
			 void *objptr, void **valp)
{
  const type_info &catch_type = *(const type_info *)catch_type_r;
  const type_info &throw_type = *(const type_info *)throw_type_r;

  *valp = objptr;

#if !defined(__GXX_ABI_VERSION) || __GXX_ABI_VERSION < 100
// old abi
  if (catch_type == throw_type)
    return 1;
  
  if (const __user_type_info *p
      = dynamic_cast <const __user_type_info *> (&throw_type))
    {
      return p->upcast (catch_type, objptr, valp);
    }
  else if (const __pointer_type_info *fr =
	   dynamic_cast <const __pointer_type_info *> (&throw_type))
    {
      const __pointer_type_info *to =
	   dynamic_cast <const __pointer_type_info *> (&catch_type);

      if (! to)
	return 0;

      const type_info *subfr = &fr->type, *subto = &to->type;
      __attr_type_info::cv cvfrom, cvto;

      if (const __attr_type_info *at
	  = dynamic_cast <const __attr_type_info *> (subfr))
	{
	  cvfrom = at->attr;
	  subfr = &at->type;
	}
      else
	cvfrom = __attr_type_info::NONE;
      
      if (const __attr_type_info *at
	  = dynamic_cast <const __attr_type_info *> (subto))
	{
	  cvto = at->attr;
	  subto = &at->type;
	}
      else
	cvto = __attr_type_info::NONE;

      if (((cvfrom & __attr_type_info::CONST)
	   > (cvto & __attr_type_info::CONST))
	  || ((cvfrom & __attr_type_info::VOLATILE)
	      > (cvto & __attr_type_info::VOLATILE)))
	return 0;

      if (*subto == *subfr)
	return 1;
      else if (*subto == typeid (void)
	       && dynamic_cast <const __func_type_info *> (subfr) == 0)
	return 1;
      else if (const __user_type_info *p
	       = dynamic_cast <const __user_type_info *> (subfr))
	return p->upcast (*subto, objptr, valp);
      else if (const __pointer_type_info *pfr
	       = dynamic_cast <const __pointer_type_info *> (subfr))
	{
	  // Multi-level pointer conversion.

	  const __pointer_type_info *pto
	    = dynamic_cast <const __pointer_type_info *> (subto);

	  if (! pto)
	    return 0;
	    
	  bool constp = (cvto & __attr_type_info::CONST);
	  for (subto = &pto->type, subfr = &pfr->type; ;
	       subto = &pto->type, subfr = &pfr->type)
	    {
	      if (const __attr_type_info *at
		  = dynamic_cast <const __attr_type_info *> (subfr))
		{
		  cvfrom = at->attr;
		  subfr = &at->type;
		}
	      else
		cvfrom = __attr_type_info::NONE;
      
	      if (const __attr_type_info *at
		  = dynamic_cast <const __attr_type_info *> (subto))
		{
		  cvto = at->attr;
		  subto = &at->type;
		}
	      else
		cvto = __attr_type_info::NONE;

	      if (((cvfrom & __attr_type_info::CONST)
		   > (cvto & __attr_type_info::CONST))
		  || ((cvfrom & __attr_type_info::VOLATILE)
		      > (cvto & __attr_type_info::VOLATILE)))
		return 0;

	      if (! constp
		  && (((cvfrom & __attr_type_info::CONST)
		       < (cvto & __attr_type_info::CONST))
		      || ((cvfrom & __attr_type_info::VOLATILE)
			  < (cvto & __attr_type_info::VOLATILE))))
		return 0;

	      if (*subto == *subfr)
		return 1;

	      pto = dynamic_cast <const __pointer_type_info *> (subto);
	      pfr = dynamic_cast <const __pointer_type_info *> (subfr);
	      if (! pto || ! pfr)
		return 0;		

	      if (! (cvto & __attr_type_info::CONST))
		constp = false;
	    }
	}
    }
#else
// new abi
  
  return catch_type.__do_catch (&throw_type, valp, 1);
#endif
  return 0;
}

#if !defined(__GXX_ABI_VERSION) || __GXX_ABI_VERSION < 100
/* Backward compatibility wrapper.  */

extern "C" void*
__throw_type_match_rtti (const void *catch_type_r, const void *throw_type_r,
			 void *objptr)
{
  void *ret;
  if (__throw_type_match_rtti_2 (catch_type_r, throw_type_r, objptr, &ret))
    return ret;
  return NULL;
}
#endif

/* Called from __cp_pop_exception.  Is P the type_info node for a pointer
   of some kind?  */

bool
__is_pointer (void *p)
{
  const type_info *t = reinterpret_cast <const type_info *>(p);
#if !defined(__GXX_ABI_VERSION) || __GXX_ABI_VERSION < 100
// old abi
  const __pointer_type_info *pt =
    dynamic_cast <const __pointer_type_info *> (t);
  return pt != 0;
#else
// new abi
  return t->__is_pointer_p ();
#endif
}

#if !defined(__GXX_ABI_VERSION) || __GXX_ABI_VERSION < 100
// old abi

extern "C" void
__rtti_ptr (void *addr, const char *n, const type_info *ti)
{ new (addr) __pointer_type_info (n, *ti); }

extern "C" void
__rtti_attr (void *addr, const char *n, int attrval, const type_info *ti)
{
  new (addr) __attr_type_info
    (n, static_cast <__attr_type_info::cv> (attrval), *ti);
}

extern "C" void
__rtti_func (void *addr, const char *name)
{ new (addr) __func_type_info (name); }

extern "C" void
__rtti_ptmf (void *addr, const char *name)
{ new (addr) __ptmf_type_info (name); }

extern "C" void
__rtti_ptmd (void *addr, const char *name)
{ new (addr) __ptmd_type_info (name); }

extern "C" void
__rtti_array (void *addr, const char *name)
{ new (addr) __array_type_info (name); }

extern "C" void *
__dynamic_cast (const type_info& (*from)(void), const type_info& (*to)(void),
		int require_public, void *address, const type_info & (*sub)(void), void *subptr)
{
  if (!require_public) abort();
  return static_cast <__user_type_info const &> (from ()).dyncast
      (/*boff=*/-1, to (), address, sub (), subptr);
}

extern "C" void *
__dynamic_cast_2 (const type_info& (*from)(void), const type_info& (*to)(void),
                  int boff,
		  void *address, const type_info & (*sub)(void), void *subptr)
{
  return static_cast <__user_type_info const &> (from ()).dyncast
      (boff, to (), address, sub (), subptr);
}

// type_info nodes and functions for the builtin types.  The mangling here
// must match the mangling in gcc/cp/rtti.c.

#define BUILTIN(mangled)					\
unsigned char __ti##mangled [sizeof (__builtin_type_info)]	\
  __attribute__ ((aligned (__alignof__ (void *))));		\
extern "C" const type_info &__tf##mangled (void) {		\
  if ((*(void **) __ti##mangled) == 0)				\
    new (__ti##mangled) __builtin_type_info (#mangled);		\
  return *(type_info *)__ti##mangled;				\
}

BUILTIN (v); BUILTIN (x); BUILTIN (l); BUILTIN (i); BUILTIN (s); BUILTIN (b);
BUILTIN (c); BUILTIN (w); BUILTIN (r); BUILTIN (d); BUILTIN (f);
BUILTIN (Ui); BUILTIN (Ul); BUILTIN (Ux); BUILTIN (Us); BUILTIN (Uc);
BUILTIN (Sc);

#endif
-------------- next part --------------
// 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() { }
  virtual ~bad_cast() { }
};

class bad_typeid : public exception {
 public:
  bad_typeid () { }
  virtual ~bad_typeid () { }
};

} // namespace std

} // extern "C++"
#endif


More information about the cxx-abi-dev mailing list