1 // The -*- C++ -*- dynamic memory management header. 2 3 // Copyright (C) 1994-2022 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 #pragma GCC visibility push(default) 44 45 extern "C++" { 46 47 namespace std 48 { 49 /** 50 * @brief Exception possibly thrown by @c new. 51 * @ingroup exceptions 52 * 53 * @c bad_alloc (or classes derived from it) is used to report allocation 54 * errors from the throwing forms of @c new. */ 55 class bad_alloc : public exception 56 { 57 public: 58 bad_alloc() throw() { } 59 60 #if __cplusplus >= 201103L 61 bad_alloc(const bad_alloc&) = default; 62 bad_alloc& operator=(const bad_alloc&) = default; 63 #endif 64 65 // This declaration is not useless: 66 // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118 67 virtual ~bad_alloc() throw(); 68 69 // See comment in eh_exception.cc. 70 virtual const char* what() const throw(); 71 }; 72 73 #if __cplusplus >= 201103L 74 class bad_array_new_length : public bad_alloc 75 { 76 public: 77 bad_array_new_length() throw() { } 78 79 // This declaration is not useless: 80 // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118 81 virtual ~bad_array_new_length() throw(); 82 83 // See comment in eh_exception.cc. 84 virtual const char* what() const throw(); 85 }; 86 #endif 87 88 #if __cpp_aligned_new 89 enum class align_val_t: size_t {}; 90 #endif 91 92 struct nothrow_t 93 { 94 #if __cplusplus >= 201103L 95 explicit nothrow_t() = default; 96 #endif 97 }; 98 99 extern const nothrow_t nothrow; 100 101 /** If you write your own error handler to be called by @c new, it must 102 * be of this type. */ 103 typedef void (*new_handler)(); 104 105 /// Takes a replacement handler as the argument, returns the 106 /// previous handler. 107 new_handler set_new_handler(new_handler) throw(); 108 109 #if __cplusplus >= 201103L 110 /// Return the current new handler. 111 new_handler get_new_handler() noexcept; 112 #endif 113 } // namespace std 114 115 //@{ 116 /** These are replaceable signatures: 117 * - normal single new and delete (no arguments, throw @c bad_alloc on error) 118 * - normal array new and delete (same) 119 * - @c nothrow single new and delete (take a @c nothrow argument, return 120 * @c NULL on error) 121 * - @c nothrow array new and delete (same) 122 * 123 * Placement new and delete signatures (take a memory address argument, 124 * does nothing) may not be replaced by a user's program. 125 */ 126 _GLIBCXX_NODISCARD void* operator new(std::size_t) _GLIBCXX_THROW (std::bad_alloc) 127 __attribute__((__externally_visible__)); 128 _GLIBCXX_NODISCARD void* operator new[](std::size_t) _GLIBCXX_THROW (std::bad_alloc) 129 __attribute__((__externally_visible__)); 130 void operator delete(void*) _GLIBCXX_USE_NOEXCEPT 131 __attribute__((__externally_visible__)); 132 void operator delete[](void*) _GLIBCXX_USE_NOEXCEPT 133 __attribute__((__externally_visible__)); 134 #if __cpp_sized_deallocation 135 void operator delete(void*, std::size_t) _GLIBCXX_USE_NOEXCEPT 136 __attribute__((__externally_visible__)); 137 void operator delete[](void*, std::size_t) _GLIBCXX_USE_NOEXCEPT 138 __attribute__((__externally_visible__)); 139 #endif 140 _GLIBCXX_NODISCARD void* operator new(std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT 141 __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); 142 _GLIBCXX_NODISCARD void* operator new[](std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT 143 __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); 144 void operator delete(void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT 145 __attribute__((__externally_visible__)); 146 void operator delete[](void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT 147 __attribute__((__externally_visible__)); 148 #if __cpp_aligned_new 149 _GLIBCXX_NODISCARD void* operator new(std::size_t, std::align_val_t) 150 __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); 151 _GLIBCXX_NODISCARD void* operator new(std::size_t, std::align_val_t, const std::nothrow_t&) 152 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); 153 void operator delete(void*, std::align_val_t) 154 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 155 void operator delete(void*, std::align_val_t, const std::nothrow_t&) 156 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 157 _GLIBCXX_NODISCARD void* operator new[](std::size_t, std::align_val_t) 158 __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); 159 _GLIBCXX_NODISCARD void* operator new[](std::size_t, std::align_val_t, const std::nothrow_t&) 160 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); 161 void operator delete[](void*, std::align_val_t) 162 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 163 void operator delete[](void*, std::align_val_t, const std::nothrow_t&) 164 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 165 #if __cpp_sized_deallocation 166 void operator delete(void*, std::size_t, std::align_val_t) 167 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 168 void operator delete[](void*, std::size_t, std::align_val_t) 169 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 170 #endif // __cpp_sized_deallocation 171 #endif // __cpp_aligned_new 172 173 // Default placement versions of operator new. 174 _GLIBCXX_NODISCARD inline void* operator new(std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT 175 { return __p; } 176 _GLIBCXX_NODISCARD inline void* operator new[](std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT 177 { return __p; } 178 179 // Default placement versions of operator delete. 180 inline void operator delete (void*, void*) _GLIBCXX_USE_NOEXCEPT { } 181 inline void operator delete[](void*, void*) _GLIBCXX_USE_NOEXCEPT { } 182 //@} 183 } // extern "C++" 184 185 #if __cplusplus >= 201703L 186 namespace std 187 { 188 #ifdef _GLIBCXX_HAVE_BUILTIN_LAUNDER 189 #define __cpp_lib_launder 201606L 190 /// Pointer optimization barrier [ptr.launder] 191 template<typename _Tp> 192 [[nodiscard]] constexpr _Tp* 193 launder(_Tp* __p) noexcept 194 { return __builtin_launder(__p); } 195 196 // The program is ill-formed if T is a function type or 197 // (possibly cv-qualified) void. 198 199 template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM> 200 void launder(_Ret (*)(_Args...) _GLIBCXX_NOEXCEPT_QUAL) = delete; 201 template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM> 202 void launder(_Ret (*)(_Args......) _GLIBCXX_NOEXCEPT_QUAL) = delete; 203 204 void launder(void*) = delete; 205 void launder(const void*) = delete; 206 void launder(volatile void*) = delete; 207 void launder(const volatile void*) = delete; 208 #endif // _GLIBCXX_HAVE_BUILTIN_LAUNDER 209 210 #ifdef __GCC_DESTRUCTIVE_SIZE 211 # define __cpp_lib_hardware_interference_size 201703L 212 inline constexpr size_t hardware_destructive_interference_size = __GCC_DESTRUCTIVE_SIZE; 213 inline constexpr size_t hardware_constructive_interference_size = __GCC_CONSTRUCTIVE_SIZE; 214 #endif // __GCC_DESTRUCTIVE_SIZE 215 } 216 #endif // C++17 217 218 #if __cplusplus > 201703L 219 namespace std 220 { 221 /// Tag type used to declare a class-specific operator delete that can 222 /// invoke the destructor before deallocating the memory. 223 struct destroying_delete_t 224 { 225 explicit destroying_delete_t() = default; 226 }; 227 /// Tag variable of type destroying_delete_t. 228 inline constexpr destroying_delete_t destroying_delete{}; 229 } 230 // Only define the feature test macro if the compiler supports the feature: 231 #if __cpp_impl_destroying_delete 232 # define __cpp_lib_destroying_delete 201806L 233 #endif 234 #endif // C++20 235 236 #pragma GCC visibility pop 237 238 #endif 239
Indexes created Sun Apr 19 00:22:55 UTC 2026