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