libstdc++
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00001 // The -*- C++ -*- dynamic memory management header. 00002 00003 // Copyright (C) 1994-2019 Free Software Foundation, Inc. 00004 00005 // This file is part of GCC. 00006 // 00007 // GCC is free software; you can redistribute it and/or modify 00008 // it under the terms of the GNU General Public License as published by 00009 // the Free Software Foundation; either version 3, or (at your option) 00010 // any later version. 00011 // 00012 // GCC is distributed in the hope that it will be useful, 00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00015 // GNU General Public License for more details. 00016 // 00017 // Under Section 7 of GPL version 3, you are granted additional 00018 // permissions described in the GCC Runtime Library Exception, version 00019 // 3.1, as published by the Free Software Foundation. 00020 00021 // You should have received a copy of the GNU General Public License and 00022 // a copy of the GCC Runtime Library Exception along with this program; 00023 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00024 // <http://www.gnu.org/licenses/>. 00025 00026 /** @file new 00027 * This is a Standard C++ Library header. 00028 * 00029 * The header @c new defines several functions to manage dynamic memory and 00030 * handling memory allocation errors; see 00031 * http://gcc.gnu.org/onlinedocs/libstdc++/18_support/howto.html#4 for more. 00032 */ 00033 00034 #ifndef _NEW 00035 #define _NEW 00036 00037 #pragma GCC system_header 00038 00039 #include <bits/c++config.h> 00040 #include <exception> 00041 00042 #pragma GCC visibility push(default) 00043 00044 extern "C++" { 00045 00046 namespace std 00047 { 00048 /** 00049 * @brief Exception possibly thrown by @c new. 00050 * @ingroup exceptions 00051 * 00052 * @c bad_alloc (or classes derived from it) is used to report allocation 00053 * errors from the throwing forms of @c new. */ 00054 class bad_alloc : public exception 00055 { 00056 public: 00057 bad_alloc() throw() { } 00058 00059 #if __cplusplus >= 201103L 00060 bad_alloc(const bad_alloc&) = default; 00061 bad_alloc& operator=(const bad_alloc&) = default; 00062 #endif 00063 00064 // This declaration is not useless: 00065 // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118 00066 virtual ~bad_alloc() throw(); 00067 00068 // See comment in eh_exception.cc. 00069 virtual const char* what() const throw(); 00070 }; 00071 00072 #if __cplusplus >= 201103L 00073 class bad_array_new_length : public bad_alloc 00074 { 00075 public: 00076 bad_array_new_length() throw() { } 00077 00078 // This declaration is not useless: 00079 // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118 00080 virtual ~bad_array_new_length() throw(); 00081 00082 // See comment in eh_exception.cc. 00083 virtual const char* what() const throw(); 00084 }; 00085 #endif 00086 00087 #if __cpp_aligned_new 00088 enum class align_val_t: size_t {}; 00089 #endif 00090 00091 struct nothrow_t 00092 { 00093 #if __cplusplus >= 201103L 00094 explicit nothrow_t() = default; 00095 #endif 00096 }; 00097 00098 extern const nothrow_t nothrow; 00099 00100 /** If you write your own error handler to be called by @c new, it must 00101 * be of this type. */ 00102 typedef void (*new_handler)(); 00103 00104 /// Takes a replacement handler as the argument, returns the 00105 /// previous handler. 00106 new_handler set_new_handler(new_handler) throw(); 00107 00108 #if __cplusplus >= 201103L 00109 /// Return the current new handler. 00110 new_handler get_new_handler() noexcept; 00111 #endif 00112 } // namespace std 00113 00114 //@{ 00115 /** These are replaceable signatures: 00116 * - normal single new and delete (no arguments, throw @c bad_alloc on error) 00117 * - normal array new and delete (same) 00118 * - @c nothrow single new and delete (take a @c nothrow argument, return 00119 * @c NULL on error) 00120 * - @c nothrow array new and delete (same) 00121 * 00122 * Placement new and delete signatures (take a memory address argument, 00123 * does nothing) may not be replaced by a user's program. 00124 */ 00125 _GLIBCXX_NODISCARD void* operator new(std::size_t) _GLIBCXX_THROW (std::bad_alloc) 00126 __attribute__((__externally_visible__)); 00127 _GLIBCXX_NODISCARD void* operator new[](std::size_t) _GLIBCXX_THROW (std::bad_alloc) 00128 __attribute__((__externally_visible__)); 00129 void operator delete(void*) _GLIBCXX_USE_NOEXCEPT 00130 __attribute__((__externally_visible__)); 00131 void operator delete[](void*) _GLIBCXX_USE_NOEXCEPT 00132 __attribute__((__externally_visible__)); 00133 #if __cpp_sized_deallocation 00134 void operator delete(void*, std::size_t) _GLIBCXX_USE_NOEXCEPT 00135 __attribute__((__externally_visible__)); 00136 void operator delete[](void*, std::size_t) _GLIBCXX_USE_NOEXCEPT 00137 __attribute__((__externally_visible__)); 00138 #endif 00139 _GLIBCXX_NODISCARD void* operator new(std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT 00140 __attribute__((__externally_visible__, __malloc__)); 00141 _GLIBCXX_NODISCARD void* operator new[](std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT 00142 __attribute__((__externally_visible__, __malloc__)); 00143 void operator delete(void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT 00144 __attribute__((__externally_visible__)); 00145 void operator delete[](void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT 00146 __attribute__((__externally_visible__)); 00147 #if __cpp_aligned_new 00148 _GLIBCXX_NODISCARD void* operator new(std::size_t, std::align_val_t) 00149 __attribute__((__externally_visible__)); 00150 _GLIBCXX_NODISCARD void* operator new(std::size_t, std::align_val_t, const std::nothrow_t&) 00151 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __malloc__)); 00152 void operator delete(void*, std::align_val_t) 00153 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 00154 void operator delete(void*, std::align_val_t, const std::nothrow_t&) 00155 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 00156 _GLIBCXX_NODISCARD void* operator new[](std::size_t, std::align_val_t) 00157 __attribute__((__externally_visible__)); 00158 _GLIBCXX_NODISCARD void* operator new[](std::size_t, std::align_val_t, const std::nothrow_t&) 00159 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __malloc__)); 00160 void operator delete[](void*, std::align_val_t) 00161 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 00162 void operator delete[](void*, std::align_val_t, const std::nothrow_t&) 00163 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 00164 #if __cpp_sized_deallocation 00165 void operator delete(void*, std::size_t, std::align_val_t) 00166 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 00167 void operator delete[](void*, std::size_t, std::align_val_t) 00168 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 00169 #endif // __cpp_sized_deallocation 00170 #endif // __cpp_aligned_new 00171 00172 // Default placement versions of operator new. 00173 _GLIBCXX_NODISCARD inline void* operator new(std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT 00174 { return __p; } 00175 _GLIBCXX_NODISCARD inline void* operator new[](std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT 00176 { return __p; } 00177 00178 // Default placement versions of operator delete. 00179 inline void operator delete (void*, void*) _GLIBCXX_USE_NOEXCEPT { } 00180 inline void operator delete[](void*, void*) _GLIBCXX_USE_NOEXCEPT { } 00181 //@} 00182 } // extern "C++" 00183 00184 #if __cplusplus >= 201703L 00185 #ifdef _GLIBCXX_HAVE_BUILTIN_LAUNDER 00186 namespace std 00187 { 00188 #define __cpp_lib_launder 201606 00189 /// Pointer optimization barrier [ptr.launder] 00190 template<typename _Tp> 00191 [[nodiscard]] constexpr _Tp* 00192 launder(_Tp* __p) noexcept 00193 { return __builtin_launder(__p); } 00194 00195 // The program is ill-formed if T is a function type or 00196 // (possibly cv-qualified) void. 00197 00198 template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM> 00199 void launder(_Ret (*)(_Args...) _GLIBCXX_NOEXCEPT_QUAL) = delete; 00200 template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM> 00201 void launder(_Ret (*)(_Args......) _GLIBCXX_NOEXCEPT_QUAL) = delete; 00202 00203 void launder(void*) = delete; 00204 void launder(const void*) = delete; 00205 void launder(volatile void*) = delete; 00206 void launder(const volatile void*) = delete; 00207 } 00208 #endif // _GLIBCXX_HAVE_BUILTIN_LAUNDER 00209 #endif // C++17 00210 00211 #if __cplusplus > 201703L 00212 namespace std 00213 { 00214 struct destroying_delete_t 00215 { 00216 explicit destroying_delete_t() = default; 00217 }; 00218 inline constexpr destroying_delete_t destroying_delete{}; 00219 } 00220 // Only define the feature test macro if the compiler supports the feature: 00221 #if __cpp_impl_destroying_delete 00222 # define __cpp_lib_destroying_delete 201806L 00223 #endif 00224 #endif // C++20 00225 00226 #pragma GCC visibility pop 00227 00228 #endif