debug_allocator.h
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// Allocators -*- C++ -*-
// Copyright (C) 2001-2021 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library 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 3, or (at your option)
// any later version.
// This library 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.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/*
* Copyright (c) 1996-1997
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/** @file ext/debug_allocator.h
* This file is a GNU extension to the Standard C++ Library.
*/
#ifndef _DEBUG_ALLOCATOR_H
#define _DEBUG_ALLOCATOR_H 1
#include <stdexcept>
#include <bits/functexcept.h>
#include <ext/alloc_traits.h>
namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @brief A meta-allocator with debugging bits.
* @ingroup allocators
*
* This is precisely the allocator defined in the C++03 Standard.
*/
template<typename _Alloc>
class debug_allocator
{
template<typename> friend class debug_allocator;
typedef __alloc_traits<_Alloc> _Traits;
public:
typedef typename _Traits::size_type size_type;
typedef typename _Traits::difference_type difference_type;
typedef typename _Traits::pointer pointer;
typedef typename _Traits::const_pointer const_pointer;
typedef typename _Traits::reference reference;
typedef typename _Traits::const_reference const_reference;
typedef typename _Traits::value_type value_type;
template<typename _Up>
class rebind
{
typedef typename _Traits::template rebind<_Up>::other __other;
public:
typedef debug_allocator<__other> other;
};
private:
// _M_extra is the number of objects that correspond to the
// extra space where debug information is stored.
size_type _M_extra;
_Alloc _M_allocator;
template<typename _Alloc2,
typename = typename __alloc_traits<_Alloc2>::template
rebind<value_type>::other>
struct __convertible
{ };
template<typename _Alloc2>
struct __convertible<_Alloc2, _Alloc>
{
typedef void* __type;
};
size_type _S_extra()
{
const std::size_t __obj_size = sizeof(value_type);
return (sizeof(size_type) + __obj_size - 1) / __obj_size;
}
public:
debug_allocator() : _M_extra(_S_extra()) { }
template<typename _Alloc2>
debug_allocator(const debug_allocator<_Alloc2>& __a2,
typename __convertible<_Alloc2>::__type = 0)
: _M_extra(_S_extra()), _M_allocator(__a2._M_allocator) { }
debug_allocator(const _Alloc& __a)
: _M_extra(_S_extra()), _M_allocator(__a) { }
_GLIBCXX_NODISCARD pointer
allocate(size_type __n)
{
pointer __res = _M_allocator.allocate(__n + _M_extra);
size_type* __ps = reinterpret_cast<size_type*>(__res);
*__ps = __n;
return __res + _M_extra;
}
_GLIBCXX_NODISCARD pointer
allocate(size_type __n, const void* __hint)
{
pointer __res = _M_allocator.allocate(__n + _M_extra, __hint);
size_type* __ps = reinterpret_cast<size_type*>(__res);
*__ps = __n;
return __res + _M_extra;
}
void
deallocate(pointer __p, size_type __n)
{
using std::__throw_runtime_error;
if (__p)
{
pointer __real_p = __p - _M_extra;
if (*reinterpret_cast<size_type*>(__real_p) != __n)
__throw_runtime_error("debug_allocator::deallocate wrong size");
_M_allocator.deallocate(__real_p, __n + _M_extra);
}
else
__throw_runtime_error("debug_allocator::deallocate null pointer");
}
void
construct(pointer __p, const value_type& __val)
{ _Traits::construct(_M_allocator, __p, __val); }
#if __cplusplus >= 201103L
template<typename _Tp, typename... _Args>
void
construct(_Tp* __p, _Args&&... __args)
{
_Traits::construct(_M_allocator, __p,
std::forward<_Args>(__args)...);
}
#endif
template<typename _Tp>
void
destroy(_Tp* __p)
{ _Traits::destroy(_M_allocator, __p); }
size_type
max_size() const throw()
{ return _Traits::max_size(_M_allocator) - _M_extra; }
template<typename _Alloc2>
friend bool
operator==(const debug_allocator& __lhs,
const debug_allocator<_Alloc2>& __rhs) _GLIBCXX_NOTHROW
{ return __lhs._M_allocator == debug_allocator(__rhs)._M_allocator; }
#if __cpp_impl_three_way_comparison < 201907L
template<typename _Alloc2>
friend bool
operator!=(const debug_allocator& __lhs,
const debug_allocator<_Alloc2>& __rhs) _GLIBCXX_NOTHROW
{ return !(__lhs == __rhs); }
#endif
};
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif
stdexcept
functexcept.h
__gnu_cxx
GNU extensions for public use.
__gnu_cxx::__alloc_traits
Uniform interface to C++98 and C++11 allocators.
Definition: ext/alloc_traits.h:52
__gnu_cxx::__alloc_traits::max_size
static constexpr size_type max_size(const _Alloc &__a) noexcept
The maximum supported allocation size.
Definition: bits/alloc_traits.h:389
__gnu_cxx::debug_allocator
A meta-allocator with debugging bits.
Definition: debug_allocator.h:61
alloc_traits.h