// Allocators -*- C++ -*- // Copyright (C) 2001-2020 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_allocator(__a2._M_allocator), _M_extra(_S_extra()) { } debug_allocator(const _Alloc& __a) : _M_allocator(__a), _M_extra(_S_extra()) { } _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