1 | // The -*- C++ -*- dynamic memory management header. |
2 | |
3 | // Copyright (C) 1994-2024 Free Software Foundation, Inc. |
4 | |
5 | // This file is part of GCC. |
6 | // |
7 | // GCC is free software; you can redistribute it and/or modify |
8 | // it under the terms of the GNU General Public License as published by |
9 | // the Free Software Foundation; either version 3, or (at your option) |
10 | // any later version. |
11 | // |
12 | // GCC is distributed in the hope that it will be useful, |
13 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
14 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
15 | // GNU General Public License for more details. |
16 | // |
17 | // Under Section 7 of GPL version 3, you are granted additional |
18 | // permissions described in the GCC Runtime Library Exception, version |
19 | // 3.1, as published by the Free Software Foundation. |
20 | |
21 | // You should have received a copy of the GNU General Public License and |
22 | // a copy of the GCC Runtime Library Exception along with this program; |
23 | // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
24 | // <http://www.gnu.org/licenses/>. |
25 | |
26 | /** @file new |
27 | * This is a Standard C++ Library header. |
28 | * |
29 | * The header @c new defines several functions to manage dynamic memory and |
30 | * handling memory allocation errors; see |
31 | * https://gcc.gnu.org/onlinedocs/libstdc++/manual/dynamic_memory.html |
32 | * for more. |
33 | */ |
34 | |
35 | #ifndef _NEW |
36 | #define _NEW |
37 | |
38 | #pragma GCC system_header |
39 | |
40 | #include <bits/c++config.h> |
41 | #include <bits/exception.h> |
42 | |
43 | #define __glibcxx_want_launder |
44 | #define __glibcxx_want_hardware_interference_size |
45 | #define __glibcxx_want_destroying_delete |
46 | #include <bits/version.h> |
47 | |
48 | #pragma GCC visibility push(default) |
49 | |
50 | extern "C++" { |
51 | |
52 | namespace std |
53 | { |
54 | /** |
55 | * @brief Exception possibly thrown by @c new. |
56 | * @ingroup exceptions |
57 | * |
58 | * @c bad_alloc (or classes derived from it) is used to report allocation |
59 | * errors from the throwing forms of @c new. */ |
60 | class bad_alloc : public exception |
61 | { |
62 | public: |
63 | bad_alloc() throw() { } |
64 | |
65 | #if __cplusplus >= 201103L |
66 | bad_alloc(const bad_alloc&) = default; |
67 | bad_alloc& operator=(const bad_alloc&) = default; |
68 | #endif |
69 | |
70 | // This declaration is not useless: |
71 | // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118 |
72 | virtual ~bad_alloc() throw(); |
73 | |
74 | // See comment in eh_exception.cc. |
75 | virtual const char* what() const throw(); |
76 | }; |
77 | |
78 | #if __cplusplus >= 201103L |
79 | class bad_array_new_length : public bad_alloc |
80 | { |
81 | public: |
82 | bad_array_new_length() throw() { } |
83 | |
84 | // This declaration is not useless: |
85 | // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118 |
86 | virtual ~bad_array_new_length() throw(); |
87 | |
88 | // See comment in eh_exception.cc. |
89 | virtual const char* what() const throw(); |
90 | }; |
91 | #endif |
92 | |
93 | #if __cpp_aligned_new |
94 | enum class align_val_t: size_t {}; |
95 | #endif |
96 | |
97 | struct nothrow_t |
98 | { |
99 | #if __cplusplus >= 201103L |
100 | explicit nothrow_t() = default; |
101 | #endif |
102 | }; |
103 | |
104 | extern const nothrow_t nothrow; |
105 | |
106 | /** If you write your own error handler to be called by @c new, it must |
107 | * be of this type. */ |
108 | typedef void (*new_handler)(); |
109 | |
110 | /// Takes a replacement handler as the argument, returns the |
111 | /// previous handler. |
112 | new_handler set_new_handler(new_handler) throw(); |
113 | |
114 | #if __cplusplus >= 201103L |
115 | /// Return the current new handler. |
116 | new_handler get_new_handler() noexcept; |
117 | #endif |
118 | } // namespace std |
119 | |
120 | //@{ |
121 | /** These are replaceable signatures: |
122 | * - normal single new and delete (no arguments, throw @c bad_alloc on error) |
123 | * - normal array new and delete (same) |
124 | * - @c nothrow single new and delete (take a @c nothrow argument, return |
125 | * @c NULL on error) |
126 | * - @c nothrow array new and delete (same) |
127 | * |
128 | * Placement new and delete signatures (take a memory address argument, |
129 | * does nothing) may not be replaced by a user's program. |
130 | */ |
131 | _GLIBCXX_NODISCARD void* operator new(std::size_t) _GLIBCXX_THROW (std::bad_alloc) |
132 | __attribute__((__externally_visible__)); |
133 | _GLIBCXX_NODISCARD void* operator new[](std::size_t) _GLIBCXX_THROW (std::bad_alloc) |
134 | __attribute__((__externally_visible__)); |
135 | void operator delete(void*) _GLIBCXX_USE_NOEXCEPT |
136 | __attribute__((__externally_visible__)); |
137 | void operator delete[](void*) _GLIBCXX_USE_NOEXCEPT |
138 | __attribute__((__externally_visible__)); |
139 | #if __cpp_sized_deallocation |
140 | void operator delete(void*, std::size_t) _GLIBCXX_USE_NOEXCEPT |
141 | __attribute__((__externally_visible__)); |
142 | void operator delete[](void*, std::size_t) _GLIBCXX_USE_NOEXCEPT |
143 | __attribute__((__externally_visible__)); |
144 | #endif |
145 | _GLIBCXX_NODISCARD void* operator new(std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT |
146 | __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); |
147 | _GLIBCXX_NODISCARD void* operator new[](std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT |
148 | __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); |
149 | void operator delete(void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT |
150 | __attribute__((__externally_visible__)); |
151 | void operator delete[](void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT |
152 | __attribute__((__externally_visible__)); |
153 | #if __cpp_aligned_new |
154 | _GLIBCXX_NODISCARD void* operator new(std::size_t, std::align_val_t) |
155 | __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); |
156 | _GLIBCXX_NODISCARD void* operator new(std::size_t, std::align_val_t, const std::nothrow_t&) |
157 | _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); |
158 | void operator delete(void*, std::align_val_t) |
159 | _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); |
160 | void operator delete(void*, std::align_val_t, const std::nothrow_t&) |
161 | _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); |
162 | _GLIBCXX_NODISCARD void* operator new[](std::size_t, std::align_val_t) |
163 | __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); |
164 | _GLIBCXX_NODISCARD void* operator new[](std::size_t, std::align_val_t, const std::nothrow_t&) |
165 | _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); |
166 | void operator delete[](void*, std::align_val_t) |
167 | _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); |
168 | void operator delete[](void*, std::align_val_t, const std::nothrow_t&) |
169 | _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); |
170 | #if __cpp_sized_deallocation |
171 | void operator delete(void*, std::size_t, std::align_val_t) |
172 | _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); |
173 | void operator delete[](void*, std::size_t, std::align_val_t) |
174 | _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); |
175 | #endif // __cpp_sized_deallocation |
176 | #endif // __cpp_aligned_new |
177 | |
178 | // Default placement versions of operator new. |
179 | _GLIBCXX_NODISCARD inline void* operator new(std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT |
180 | { return __p; } |
181 | _GLIBCXX_NODISCARD inline void* operator new[](std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT |
182 | { return __p; } |
183 | |
184 | // Default placement versions of operator delete. |
185 | inline void operator delete (void*, void*) _GLIBCXX_USE_NOEXCEPT { } |
186 | inline void operator delete[](void*, void*) _GLIBCXX_USE_NOEXCEPT { } |
187 | //@} |
188 | } // extern "C++" |
189 | |
190 | #if __cplusplus >= 201703L |
191 | namespace std |
192 | { |
193 | #ifdef __cpp_lib_launder // C++ >= 17 && HAVE_BUILTIN_LAUNDER |
194 | /// Pointer optimization barrier [ptr.launder] |
195 | template<typename _Tp> |
196 | [[nodiscard]] constexpr _Tp* |
197 | launder(_Tp* __p) noexcept |
198 | { return __builtin_launder(__p); } |
199 | |
200 | // The program is ill-formed if T is a function type or |
201 | // (possibly cv-qualified) void. |
202 | |
203 | template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM> |
204 | void launder(_Ret (*)(_Args...) _GLIBCXX_NOEXCEPT_QUAL) = delete; |
205 | template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM> |
206 | void launder(_Ret (*)(_Args......) _GLIBCXX_NOEXCEPT_QUAL) = delete; |
207 | |
208 | void launder(void*) = delete; |
209 | void launder(const void*) = delete; |
210 | void launder(volatile void*) = delete; |
211 | void launder(const volatile void*) = delete; |
212 | #endif // __cpp_lib_launder |
213 | |
214 | #ifdef __cpp_lib_hardware_interference_size // C++ >= 17 && defined(gcc_dest_sz) |
215 | inline constexpr size_t hardware_destructive_interference_size = __GCC_DESTRUCTIVE_SIZE; |
216 | inline constexpr size_t hardware_constructive_interference_size = __GCC_CONSTRUCTIVE_SIZE; |
217 | #endif // __cpp_lib_hardware_interference_size |
218 | } |
219 | #endif // C++17 |
220 | |
221 | // Emitted despite the FTM potentially being undefined. |
222 | #if __cplusplus > 201703L |
223 | namespace std |
224 | { |
225 | /// Tag type used to declare a class-specific operator delete that can |
226 | /// invoke the destructor before deallocating the memory. |
227 | struct destroying_delete_t |
228 | { |
229 | explicit destroying_delete_t() = default; |
230 | }; |
231 | /// Tag variable of type destroying_delete_t. |
232 | inline constexpr destroying_delete_t destroying_delete{}; |
233 | } |
234 | #endif // C++20 |
235 | |
236 | #pragma GCC visibility pop |
237 | |
238 | #endif |
239 | |