1// <memory> -*- C++ -*- 2 3// Copyright (C) 2001-2019 Free Software Foundation, Inc. 4// 5// This file is part of the GNU ISO C++ Library. This library is free 6// software; you can redistribute it and/or modify it under the 7// terms of the GNU General Public License as published by the 8// Free Software Foundation; either version 3, or (at your option) 9// any later version. 10 11// This library is distributed in the hope that it will be useful, 12// but WITHOUT ANY WARRANTY; without even the implied warranty of 13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14// GNU General Public License for more details. 15 16// Under Section 7 of GPL version 3, you are granted additional 17// permissions described in the GCC Runtime Library Exception, version 18// 3.1, as published by the Free Software Foundation. 19 20// You should have received a copy of the GNU General Public License and 21// a copy of the GCC Runtime Library Exception along with this program; 22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23// <http://www.gnu.org/licenses/>. 24 25/* 26 * Copyright (c) 1997-1999 27 * Silicon Graphics Computer Systems, Inc. 28 * 29 * Permission to use, copy, modify, distribute and sell this software 30 * and its documentation for any purpose is hereby granted without fee, 31 * provided that the above copyright notice appear in all copies and 32 * that both that copyright notice and this permission notice appear 33 * in supporting documentation. Silicon Graphics makes no 34 * representations about the suitability of this software for any 35 * purpose. It is provided "as is" without express or implied warranty. 36 * 37 */ 38 39/** @file include/memory 40 * This is a Standard C++ Library header. 41 */ 42 43#ifndef _GLIBCXX_MEMORY 44#define _GLIBCXX_MEMORY 1 45 46#pragma GCC system_header 47 48/** 49 * @defgroup memory Memory 50 * @ingroup utilities 51 * 52 * Components for memory allocation, deallocation, and management. 53 */ 54 55/** 56 * @defgroup pointer_abstractions Pointer Abstractions 57 * @ingroup memory 58 * 59 * Smart pointers, etc. 60 */ 61 62#include <bits/stl_algobase.h> 63#include <bits/allocator.h> 64#include <bits/stl_construct.h> 65#include <bits/stl_uninitialized.h> 66#include <bits/stl_tempbuf.h> 67#include <bits/stl_raw_storage_iter.h> 68 69#if __cplusplus >= 201103L 70# include <exception> // std::exception 71# include <typeinfo> // std::type_info in get_deleter 72# include <iosfwd> // std::basic_ostream 73# include <ext/atomicity.h> 74# include <ext/concurrence.h> 75# include <bits/functexcept.h> 76# include <bits/stl_function.h> // std::less 77# include <bits/uses_allocator.h> 78# include <type_traits> 79# include <debug/debug.h> 80# include <bits/unique_ptr.h> 81# include <bits/shared_ptr.h> 82# include <bits/shared_ptr_atomic.h> 83# if _GLIBCXX_USE_DEPRECATED 84# include <backward/auto_ptr.h> 85# endif 86#else 87# include <backward/auto_ptr.h> 88#endif 89 90#if __cplusplus >= 201103L 91#include <cstdint> 92#if __cplusplus > 201703L 93# include <bit> // for ispow2 94# include <new> // for placement operator new 95# include <tuple> // for tuple, make_tuple, make_from_tuple 96#endif 97namespace std _GLIBCXX_VISIBILITY(default) 98{ 99_GLIBCXX_BEGIN_NAMESPACE_VERSION 100 101/** 102 * @brief Fit aligned storage in buffer. 103 * 104 * [ptr.align] 105 * 106 * This function tries to fit @a __size bytes of storage with alignment 107 * @a __align into the buffer @a __ptr of size @a __space bytes. If such 108 * a buffer fits then @a __ptr is changed to point to the first byte of the 109 * aligned storage and @a __space is reduced by the bytes used for alignment. 110 * 111 * @param __align A fundamental or extended alignment value. 112 * @param __size Size of the aligned storage required. 113 * @param __ptr Pointer to a buffer of @a __space bytes. 114 * @param __space Size of the buffer pointed to by @a __ptr. 115 * @return the updated pointer if the aligned storage fits, otherwise nullptr. 116 */ 117inline void* 118align(size_t __align, size_t __size, void*& __ptr, size_t& __space) noexcept 119{ 120#ifdef _GLIBCXX_USE_C99_STDINT_TR1 121 const auto __intptr = reinterpret_cast<uintptr_t>(__ptr); 122#else 123 // Cannot use std::uintptr_t so assume that std::size_t can be used instead. 124 static_assert(sizeof(size_t) >= sizeof(void*), 125 "std::size_t must be a suitable substitute for std::uintptr_t"); 126 const auto __intptr = reinterpret_cast<unsigned long long>(__ptr); 127#endif 128 const auto __aligned = (__intptr - 1u + __align) & -__align; 129 const auto __diff = __aligned - __intptr; 130 if ((__size + __diff) > __space) 131 return nullptr; 132 else 133 { 134 __space -= __diff; 135 return __ptr = reinterpret_cast<void*>(__aligned); 136 } 137} 138 139// 20.7.4 [util.dynamic.safety], pointer safety 140 141enum class pointer_safety { relaxed, preferred, strict }; 142 143inline void 144declare_reachable(void*) { } 145 146template <typename _Tp> 147 inline _Tp* 148 undeclare_reachable(_Tp* __p) { return __p; } 149 150inline void 151declare_no_pointers(char*, size_t) { } 152 153inline void 154undeclare_no_pointers(char*, size_t) { } 155 156inline pointer_safety 157get_pointer_safety() noexcept { return pointer_safety::relaxed; } 158 159#if __cplusplus > 201703L 160#define __cpp_lib_assume_aligned 201811L 161 /** @brief Inform the compiler that a pointer is aligned. 162 * 163 * @tparam _Align An alignment value (i.e. a power of two) 164 * @tparam _Tp An object type 165 * @param __ptr A pointer that is aligned to _Align 166 * 167 * C++20 20.10.6 [ptr.align] 168 * 169 * @ingroup memory 170 */ 171 template<size_t _Align, class _Tp> 172 [[nodiscard,__gnu__::__always_inline__]] 173 constexpr _Tp* 174 assume_aligned(_Tp* __ptr) noexcept 175 { 176 static_assert(std::ispow2(_Align)); 177 if (std::is_constant_evaluated()) 178 return __ptr; 179 else 180 { 181 // This function is expected to be used in hot code, where 182 // __glibcxx_assert would add unwanted overhead. 183 _GLIBCXX_DEBUG_ASSERT((std::uintptr_t)__ptr % _Align == 0); 184 return static_cast<_Tp*>(__builtin_assume_aligned(__ptr, _Align)); 185 } 186 } 187#endif // C++2a 188 189#if __cplusplus > 201703L 190 template<typename _Tp> 191 struct __is_pair : false_type { }; 192 template<typename _Tp, typename _Up> 193 struct __is_pair<pair<_Tp, _Up>> : true_type { }; 194 template<typename _Tp, typename _Up> 195 struct __is_pair<const pair<_Tp, _Up>> : true_type { }; 196 197 template<typename _Tp, typename __ = _Require<__not_<__is_pair<_Tp>>>, 198 typename _Alloc, typename... _Args> 199 constexpr auto 200 __uses_alloc_args(const _Alloc& __a, _Args&&... __args) noexcept 201 { 202 if constexpr (uses_allocator_v<remove_cv_t<_Tp>, _Alloc>) 203 { 204 if constexpr (is_constructible_v<_Tp, allocator_arg_t, 205 const _Alloc&, _Args...>) 206 { 207 return tuple<allocator_arg_t, const _Alloc&, _Args&&...>( 208 allocator_arg, __a, std::forward<_Args>(__args)...); 209 } 210 else 211 { 212 static_assert(is_constructible_v<_Tp, _Args..., const _Alloc&>, 213 "construction with an allocator must be possible" 214 " if uses_allocator is true"); 215 216 return tuple<_Args&&..., const _Alloc&>( 217 std::forward<_Args>(__args)..., __a); 218 } 219 } 220 else 221 { 222 static_assert(is_constructible_v<_Tp, _Args...>); 223 224 return tuple<_Args&&...>(std::forward<_Args>(__args)...); 225 } 226 } 227 228#if __cpp_concepts 229 template<typename _Tp> 230 concept _Std_pair = __is_pair<_Tp>::value; 231#endif 232 233// This is a temporary workaround until -fconcepts is implied by -std=gnu++2a 234#if __cpp_concepts 235# define _GLIBCXX_STD_PAIR_CONSTRAINT(T) _Std_pair T 236# define _GLIBCXX_STD_PAIR_CONSTRAINT_(T) _Std_pair T 237#else 238# define _GLIBCXX_STD_PAIR_CONSTRAINT(T) \ 239 typename T, typename __ = _Require<__is_pair<T>> 240# define _GLIBCXX_STD_PAIR_CONSTRAINT_(T) typename T, typename 241#endif 242 243 template<typename _Tp, 244#if ! __cpp_concepts 245 typename __ = _Require<__not_<__is_pair<_Tp>>>, 246#endif 247 typename _Alloc, typename... _Args> 248 constexpr auto 249 uses_allocator_construction_args(const _Alloc& __a, 250 _Args&&... __args) noexcept 251#if __cpp_concepts 252 requires (! _Std_pair<_Tp>) 253#endif 254 { 255 return std::__uses_alloc_args<_Tp>(__a, std::forward<_Args>(__args)...); 256 } 257 258 template<_GLIBCXX_STD_PAIR_CONSTRAINT(_Tp), typename _Alloc, 259 typename _Tuple1, typename _Tuple2> 260 constexpr auto 261 uses_allocator_construction_args(const _Alloc& __a, piecewise_construct_t, 262 _Tuple1&& __x, _Tuple2&& __y) noexcept; 263 264 template<_GLIBCXX_STD_PAIR_CONSTRAINT(_Tp), typename _Alloc> 265 constexpr auto 266 uses_allocator_construction_args(const _Alloc&) noexcept; 267 268 template<_GLIBCXX_STD_PAIR_CONSTRAINT(_Tp), typename _Alloc, 269 typename _Up, typename _Vp> 270 constexpr auto 271 uses_allocator_construction_args(const _Alloc&, _Up&&, _Vp&&) noexcept; 272 273 template<_GLIBCXX_STD_PAIR_CONSTRAINT(_Tp), typename _Alloc, 274 typename _Up, typename _Vp> 275 constexpr auto 276 uses_allocator_construction_args(const _Alloc&, 277 const pair<_Up, _Vp>&) noexcept; 278 279 template<_GLIBCXX_STD_PAIR_CONSTRAINT(_Tp), typename _Alloc, 280 typename _Up, typename _Vp> 281 constexpr auto 282 uses_allocator_construction_args(const _Alloc&, pair<_Up, _Vp>&&) noexcept; 283 284 template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc, 285 typename _Tuple1, typename _Tuple2> 286 constexpr auto 287 uses_allocator_construction_args(const _Alloc& __a, piecewise_construct_t, 288 _Tuple1&& __x, _Tuple2&& __y) noexcept 289 { 290 using _Tp1 = typename _Tp::first_type; 291 using _Tp2 = typename _Tp::second_type; 292 293 return std::make_tuple(piecewise_construct, 294 std::apply([&__a](auto&&... __args1) { 295 return std::uses_allocator_construction_args<_Tp1>( 296 __a, std::forward<decltype(__args1)>(__args1)...); 297 }, std::forward<_Tuple1>(__x)), 298 std::apply([&__a](auto&&... __args2) { 299 return std::uses_allocator_construction_args<_Tp2>( 300 __a, std::forward<decltype(__args2)>(__args2)...); 301 }, std::forward<_Tuple2>(__y))); 302 } 303 304 template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc> 305 constexpr auto 306 uses_allocator_construction_args(const _Alloc& __a) noexcept 307 { 308 using _Tp1 = typename _Tp::first_type; 309 using _Tp2 = typename _Tp::second_type; 310 311 return std::make_tuple(piecewise_construct, 312 std::uses_allocator_construction_args<_Tp1>(__a), 313 std::uses_allocator_construction_args<_Tp2>(__a)); 314 } 315 316 template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc, 317 typename _Up, typename _Vp> 318 constexpr auto 319 uses_allocator_construction_args(const _Alloc& __a, _Up&& __u, _Vp&& __v) 320 noexcept 321 { 322 using _Tp1 = typename _Tp::first_type; 323 using _Tp2 = typename _Tp::second_type; 324 325 return std::make_tuple(piecewise_construct, 326 std::uses_allocator_construction_args<_Tp1>(__a, 327 std::forward<_Up>(__u)), 328 std::uses_allocator_construction_args<_Tp2>(__a, 329 std::forward<_Vp>(__v))); 330 } 331 332 template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc, 333 typename _Up, typename _Vp> 334 constexpr auto 335 uses_allocator_construction_args(const _Alloc& __a, 336 const pair<_Up, _Vp>& __pr) noexcept 337 { 338 using _Tp1 = typename _Tp::first_type; 339 using _Tp2 = typename _Tp::second_type; 340 341 return std::make_tuple(piecewise_construct, 342 std::uses_allocator_construction_args<_Tp1>(__a, __pr.first), 343 std::uses_allocator_construction_args<_Tp2>(__a, __pr.second)); 344 } 345 346 template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc, 347 typename _Up, typename _Vp> 348 constexpr auto 349 uses_allocator_construction_args(const _Alloc& __a, 350 pair<_Up, _Vp>&& __pr) noexcept 351 { 352 using _Tp1 = typename _Tp::first_type; 353 using _Tp2 = typename _Tp::second_type; 354 355 return std::make_tuple(piecewise_construct, 356 std::uses_allocator_construction_args<_Tp1>(__a, 357 std::move(__pr).first), 358 std::uses_allocator_construction_args<_Tp2>(__a, 359 std::move(__pr).second)); 360 } 361 362 template<typename _Tp, typename _Alloc, typename... _Args> 363 inline _Tp 364 make_obj_using_allocator(const _Alloc& __a, _Args&&... __args) 365 { 366 return std::make_from_tuple<_Tp>( 367 std::uses_allocator_construction_args<_Tp>(__a, 368 std::forward<_Args>(__args)...)); 369 } 370 371 template<typename _Tp, typename _Alloc, typename... _Args> 372 inline _Tp* 373 uninitialized_construct_using_allocator(_Tp* __p, const _Alloc& __a, 374 _Args&&... __args) 375 { 376 void* __vp = const_cast<void*>(static_cast<const volatile void*>(__p)); 377 return ::new(__vp) _Tp(std::make_obj_using_allocator<_Tp>(__a, 378 std::forward<_Args>(__args)...)); 379 } 380 381#endif // C++2a 382 383_GLIBCXX_END_NAMESPACE_VERSION 384} // namespace 385#endif // C++11 386 387#if __cplusplus > 201402L 388// Parallel STL algorithms 389# if __PSTL_EXECUTION_POLICIES_DEFINED 390// If <execution> has already been included, pull in implementations 391# include <pstl/glue_memory_impl.h> 392# else 393// Otherwise just pull in forward declarations 394# include <pstl/glue_memory_defs.h> 395# endif 396 397// Feature test macro for parallel algorithms 398# define __cpp_lib_parallel_algorithm 201603L 399#endif // C++17 400 401#endif /* _GLIBCXX_MEMORY */ 402