1// <memory> -*- C++ -*- 2 3// Copyright (C) 2001-2020 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 * @ingroup memory 42 */ 43 44#ifndef _GLIBCXX_MEMORY 45#define _GLIBCXX_MEMORY 1 46 47#pragma GCC system_header 48 49/** 50 * @defgroup memory Memory 51 * @ingroup utilities 52 * 53 * Components for memory allocation, deallocation, and management. 54 */ 55 56/** 57 * @defgroup pointer_abstractions Pointer Abstractions 58 * @ingroup memory 59 * 60 * Smart pointers, etc. 61 */ 62 63#include <bits/stl_algobase.h> 64#include <bits/allocator.h> 65#include <bits/stl_construct.h> 66#include <bits/stl_uninitialized.h> 67#include <bits/stl_tempbuf.h> 68#include <bits/stl_raw_storage_iter.h> 69#include <bits/ranges_uninitialized.h> 70 71#if __cplusplus >= 201103L 72# include <exception> // std::exception 73# include <typeinfo> // std::type_info in get_deleter 74# include <iosfwd> // std::basic_ostream 75# include <ext/atomicity.h> 76# include <ext/concurrence.h> 77# include <bits/functexcept.h> 78# include <bits/stl_function.h> // std::less 79# include <bits/uses_allocator.h> 80# include <bits/alloc_traits.h> 81# include <type_traits> 82# include <debug/debug.h> 83# include <bits/unique_ptr.h> 84# include <bits/shared_ptr.h> 85# include <bits/shared_ptr_atomic.h> 86# if _GLIBCXX_USE_DEPRECATED 87# include <backward/auto_ptr.h> 88# endif 89#else 90# include <backward/auto_ptr.h> 91#endif 92 93#if __cplusplus >= 201103L 94#include <cstdint> 95#if __cplusplus > 201703L 96# include <bit> // for has_single_bit 97# include <new> // for placement operator new 98# include <tuple> // for tuple, make_tuple, make_from_tuple 99#endif 100namespace std _GLIBCXX_VISIBILITY(default) 101{ 102_GLIBCXX_BEGIN_NAMESPACE_VERSION 103 104/** 105 * @brief Fit aligned storage in buffer. 106 * @ingroup memory 107 * 108 * This function tries to fit @a __size bytes of storage with alignment 109 * @a __align into the buffer @a __ptr of size @a __space bytes. If such 110 * a buffer fits then @a __ptr is changed to point to the first byte of the 111 * aligned storage and @a __space is reduced by the bytes used for alignment. 112 * 113 * C++11 20.6.5 [ptr.align] 114 * 115 * @param __align A fundamental or extended alignment value. 116 * @param __size Size of the aligned storage required. 117 * @param __ptr Pointer to a buffer of @a __space bytes. 118 * @param __space Size of the buffer pointed to by @a __ptr. 119 * @return the updated pointer if the aligned storage fits, otherwise nullptr. 120 * 121 */ 122inline void* 123align(size_t __align, size_t __size, void*& __ptr, size_t& __space) noexcept 124{ 125#ifdef _GLIBCXX_USE_C99_STDINT_TR1 126 const auto __intptr = reinterpret_cast<uintptr_t>(__ptr); 127#else 128 // Cannot use std::uintptr_t so assume that std::size_t can be used instead. 129 static_assert(sizeof(size_t) >= sizeof(void*), 130 "std::size_t must be a suitable substitute for std::uintptr_t"); 131 const auto __intptr = reinterpret_cast<unsigned long long>(__ptr); 132#endif 133 const auto __aligned = (__intptr - 1u + __align) & -__align; 134 const auto __diff = __aligned - __intptr; 135 if ((__size + __diff) > __space) 136 return nullptr; 137 else 138 { 139 __space -= __diff; 140 return __ptr = reinterpret_cast<void*>(__aligned); 141 } 142} 143 144/** @defgroup ptr_safety Pointer Safety and Garbage Collection 145 * @ingroup memory 146 * 147 * Utilities to assist with garbage collection in an implementation 148 * that supports <em>strict pointer safety</em>. 149 * This implementation only supports <em>relaxed pointer safety</em> 150 * and so these functions have no effect. 151 * 152 * C++11 20.6.4 [util.dynamic.safety], Pointer safety 153 * 154 * @{ 155 */ 156 157/// Constants representing the different types of pointer safety. 158enum class pointer_safety { relaxed, preferred, strict }; 159 160/// Inform a garbage collector that an object is still in use. 161inline void 162declare_reachable(void*) { } 163 164/// Unregister an object previously registered with declare_reachable. 165template <typename _Tp> 166 inline _Tp* 167 undeclare_reachable(_Tp* __p) { return __p; } 168 169/// Inform a garbage collector that a region of memory need not be traced. 170inline void 171declare_no_pointers(char*, size_t) { } 172 173/// Unregister a range previously registered with declare_no_pointers. 174inline void 175undeclare_no_pointers(char*, size_t) { } 176 177/// The type of pointer safety supported by the implementation. 178inline pointer_safety 179get_pointer_safety() noexcept { return pointer_safety::relaxed; } 180/// @} 181 182#if __cplusplus > 201703L 183#define __cpp_lib_assume_aligned 201811L 184 /** @brief Inform the compiler that a pointer is aligned. 185 * 186 * @tparam _Align An alignment value (i.e. a power of two) 187 * @tparam _Tp An object type 188 * @param __ptr A pointer that is aligned to _Align 189 * 190 * C++20 20.10.6 [ptr.align] 191 * 192 * @ingroup memory 193 */ 194 template<size_t _Align, class _Tp> 195 [[nodiscard,__gnu__::__always_inline__]] 196 constexpr _Tp* 197 assume_aligned(_Tp* __ptr) noexcept 198 { 199 static_assert(std::has_single_bit(_Align)); 200 if (std::is_constant_evaluated()) 201 return __ptr; 202 else 203 { 204 // This function is expected to be used in hot code, where 205 // __glibcxx_assert would add unwanted overhead. 206 _GLIBCXX_DEBUG_ASSERT((std::uintptr_t)__ptr % _Align == 0); 207 return static_cast<_Tp*>(__builtin_assume_aligned(__ptr, _Align)); 208 } 209 } 210#endif // C++2a 211 212#if __cplusplus > 201703L 213 template<typename _Tp> 214 struct __is_pair : false_type { }; 215 template<typename _Tp, typename _Up> 216 struct __is_pair<pair<_Tp, _Up>> : true_type { }; 217 template<typename _Tp, typename _Up> 218 struct __is_pair<const pair<_Tp, _Up>> : true_type { }; 219 220/** @addtogroup allocators 221 * @{ 222 */ 223 template<typename _Tp, typename __ = _Require<__not_<__is_pair<_Tp>>>, 224 typename _Alloc, typename... _Args> 225 constexpr auto 226 __uses_alloc_args(const _Alloc& __a, _Args&&... __args) noexcept 227 { 228 if constexpr (uses_allocator_v<remove_cv_t<_Tp>, _Alloc>) 229 { 230 if constexpr (is_constructible_v<_Tp, allocator_arg_t, 231 const _Alloc&, _Args...>) 232 { 233 return tuple<allocator_arg_t, const _Alloc&, _Args&&...>( 234 allocator_arg, __a, std::forward<_Args>(__args)...); 235 } 236 else 237 { 238 static_assert(is_constructible_v<_Tp, _Args..., const _Alloc&>, 239 "construction with an allocator must be possible" 240 " if uses_allocator is true"); 241 242 return tuple<_Args&&..., const _Alloc&>( 243 std::forward<_Args>(__args)..., __a); 244 } 245 } 246 else 247 { 248 static_assert(is_constructible_v<_Tp, _Args...>); 249 250 return tuple<_Args&&...>(std::forward<_Args>(__args)...); 251 } 252 } 253 254#if __cpp_concepts 255 template<typename _Tp> 256 concept _Std_pair = __is_pair<_Tp>::value; 257#endif 258 259// This is a temporary workaround until -fconcepts is implied by -std=gnu++2a 260#if __cpp_concepts 261# define _GLIBCXX_STD_PAIR_CONSTRAINT(T) _Std_pair T 262# define _GLIBCXX_STD_PAIR_CONSTRAINT_(T) _Std_pair T 263#else 264# define _GLIBCXX_STD_PAIR_CONSTRAINT(T) \ 265 typename T, typename __ = _Require<__is_pair<T>> 266# define _GLIBCXX_STD_PAIR_CONSTRAINT_(T) typename T, typename 267#endif 268 269 template<typename _Tp, 270#if ! __cpp_concepts 271 typename __ = _Require<__not_<__is_pair<_Tp>>>, 272#endif 273 typename _Alloc, typename... _Args> 274 constexpr auto 275 uses_allocator_construction_args(const _Alloc& __a, 276 _Args&&... __args) noexcept 277#if __cpp_concepts 278 requires (! _Std_pair<_Tp>) 279#endif 280 { 281 return std::__uses_alloc_args<_Tp>(__a, std::forward<_Args>(__args)...); 282 } 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 template<_GLIBCXX_STD_PAIR_CONSTRAINT(_Tp), typename _Alloc> 291 constexpr auto 292 uses_allocator_construction_args(const _Alloc&) noexcept; 293 294 template<_GLIBCXX_STD_PAIR_CONSTRAINT(_Tp), typename _Alloc, 295 typename _Up, typename _Vp> 296 constexpr auto 297 uses_allocator_construction_args(const _Alloc&, _Up&&, _Vp&&) noexcept; 298 299 template<_GLIBCXX_STD_PAIR_CONSTRAINT(_Tp), typename _Alloc, 300 typename _Up, typename _Vp> 301 constexpr auto 302 uses_allocator_construction_args(const _Alloc&, 303 const pair<_Up, _Vp>&) noexcept; 304 305 template<_GLIBCXX_STD_PAIR_CONSTRAINT(_Tp), typename _Alloc, 306 typename _Up, typename _Vp> 307 constexpr auto 308 uses_allocator_construction_args(const _Alloc&, pair<_Up, _Vp>&&) noexcept; 309 310 template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc, 311 typename _Tuple1, typename _Tuple2> 312 constexpr auto 313 uses_allocator_construction_args(const _Alloc& __a, piecewise_construct_t, 314 _Tuple1&& __x, _Tuple2&& __y) noexcept 315 { 316 using _Tp1 = typename _Tp::first_type; 317 using _Tp2 = typename _Tp::second_type; 318 319 return std::make_tuple(piecewise_construct, 320 std::apply([&__a](auto&&... __args1) { 321 return std::uses_allocator_construction_args<_Tp1>( 322 __a, std::forward<decltype(__args1)>(__args1)...); 323 }, std::forward<_Tuple1>(__x)), 324 std::apply([&__a](auto&&... __args2) { 325 return std::uses_allocator_construction_args<_Tp2>( 326 __a, std::forward<decltype(__args2)>(__args2)...); 327 }, std::forward<_Tuple2>(__y))); 328 } 329 330 template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc> 331 constexpr auto 332 uses_allocator_construction_args(const _Alloc& __a) noexcept 333 { 334 using _Tp1 = typename _Tp::first_type; 335 using _Tp2 = typename _Tp::second_type; 336 337 return std::make_tuple(piecewise_construct, 338 std::uses_allocator_construction_args<_Tp1>(__a), 339 std::uses_allocator_construction_args<_Tp2>(__a)); 340 } 341 342 template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc, 343 typename _Up, typename _Vp> 344 constexpr auto 345 uses_allocator_construction_args(const _Alloc& __a, _Up&& __u, _Vp&& __v) 346 noexcept 347 { 348 using _Tp1 = typename _Tp::first_type; 349 using _Tp2 = typename _Tp::second_type; 350 351 return std::make_tuple(piecewise_construct, 352 std::uses_allocator_construction_args<_Tp1>(__a, 353 std::forward<_Up>(__u)), 354 std::uses_allocator_construction_args<_Tp2>(__a, 355 std::forward<_Vp>(__v))); 356 } 357 358 template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc, 359 typename _Up, typename _Vp> 360 constexpr auto 361 uses_allocator_construction_args(const _Alloc& __a, 362 const pair<_Up, _Vp>& __pr) noexcept 363 { 364 using _Tp1 = typename _Tp::first_type; 365 using _Tp2 = typename _Tp::second_type; 366 367 return std::make_tuple(piecewise_construct, 368 std::uses_allocator_construction_args<_Tp1>(__a, __pr.first), 369 std::uses_allocator_construction_args<_Tp2>(__a, __pr.second)); 370 } 371 372 template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc, 373 typename _Up, typename _Vp> 374 constexpr auto 375 uses_allocator_construction_args(const _Alloc& __a, 376 pair<_Up, _Vp>&& __pr) noexcept 377 { 378 using _Tp1 = typename _Tp::first_type; 379 using _Tp2 = typename _Tp::second_type; 380 381 return std::make_tuple(piecewise_construct, 382 std::uses_allocator_construction_args<_Tp1>(__a, 383 std::move(__pr).first), 384 std::uses_allocator_construction_args<_Tp2>(__a, 385 std::move(__pr).second)); 386 } 387 388 template<typename _Tp, typename _Alloc, typename... _Args> 389 inline _Tp 390 make_obj_using_allocator(const _Alloc& __a, _Args&&... __args) 391 { 392 return std::make_from_tuple<_Tp>( 393 std::uses_allocator_construction_args<_Tp>(__a, 394 std::forward<_Args>(__args)...)); 395 } 396 397 template<typename _Tp, typename _Alloc, typename... _Args> 398 inline _Tp* 399 uninitialized_construct_using_allocator(_Tp* __p, const _Alloc& __a, 400 _Args&&... __args) 401 { 402 return std::apply([&](auto&&... __xs) { 403 return std::construct_at(__p, std::forward<decltype(__xs)>(__xs)...); 404 }, std::uses_allocator_construction_args<_Tp>(__a, 405 std::forward<_Args>(__args)...)); 406 } 407// @} 408 409#endif // C++2a 410 411_GLIBCXX_END_NAMESPACE_VERSION 412} // namespace 413#endif // C++11 414 415#if __cplusplus > 201402L 416// Parallel STL algorithms 417# if _PSTL_EXECUTION_POLICIES_DEFINED 418// If <execution> has already been included, pull in implementations 419# include <pstl/glue_memory_impl.h> 420# else 421// Otherwise just pull in forward declarations 422# include <pstl/glue_memory_defs.h> 423# endif 424 425// Feature test macro for parallel algorithms 426# define __cpp_lib_parallel_algorithm 201603L 427#endif // C++17 428 429#endif /* _GLIBCXX_MEMORY */ 430