libstdc++
|
00001 // The -*- C++ -*- dynamic memory management header. 00002 00003 // Copyright (C) 1994-2018 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 // This declaration is not useless: 00060 // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118 00061 virtual ~bad_alloc() throw(); 00062 00063 // See comment in eh_exception.cc. 00064 virtual const char* what() const throw(); 00065 }; 00066 00067 #if __cplusplus >= 201103L 00068 class bad_array_new_length : public bad_alloc 00069 { 00070 public: 00071 bad_array_new_length() throw() { } 00072 00073 // This declaration is not useless: 00074 // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118 00075 virtual ~bad_array_new_length() throw(); 00076 00077 // See comment in eh_exception.cc. 00078 virtual const char* what() const throw(); 00079 }; 00080 #endif 00081 00082 #if __cpp_aligned_new 00083 enum class align_val_t: size_t {}; 00084 #endif 00085 00086 struct nothrow_t 00087 { 00088 #if __cplusplus >= 201103L 00089 explicit nothrow_t() = default; 00090 #endif 00091 }; 00092 00093 extern const nothrow_t nothrow; 00094 00095 /** If you write your own error handler to be called by @c new, it must 00096 * be of this type. */ 00097 typedef void (*new_handler)(); 00098 00099 /// Takes a replacement handler as the argument, returns the 00100 /// previous handler. 00101 new_handler set_new_handler(new_handler) throw(); 00102 00103 #if __cplusplus >= 201103L 00104 /// Return the current new handler. 00105 new_handler get_new_handler() noexcept; 00106 #endif 00107 } // namespace std 00108 00109 //@{ 00110 /** These are replaceable signatures: 00111 * - normal single new and delete (no arguments, throw @c bad_alloc on error) 00112 * - normal array new and delete (same) 00113 * - @c nothrow single new and delete (take a @c nothrow argument, return 00114 * @c NULL on error) 00115 * - @c nothrow array new and delete (same) 00116 * 00117 * Placement new and delete signatures (take a memory address argument, 00118 * does nothing) may not be replaced by a user's program. 00119 */ 00120 void* operator new(std::size_t) _GLIBCXX_THROW (std::bad_alloc) 00121 __attribute__((__externally_visible__)); 00122 void* operator new[](std::size_t) _GLIBCXX_THROW (std::bad_alloc) 00123 __attribute__((__externally_visible__)); 00124 void operator delete(void*) _GLIBCXX_USE_NOEXCEPT 00125 __attribute__((__externally_visible__)); 00126 void operator delete[](void*) _GLIBCXX_USE_NOEXCEPT 00127 __attribute__((__externally_visible__)); 00128 #if __cpp_sized_deallocation 00129 void operator delete(void*, std::size_t) _GLIBCXX_USE_NOEXCEPT 00130 __attribute__((__externally_visible__)); 00131 void operator delete[](void*, std::size_t) _GLIBCXX_USE_NOEXCEPT 00132 __attribute__((__externally_visible__)); 00133 #endif 00134 void* operator new(std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT 00135 __attribute__((__externally_visible__)); 00136 void* operator new[](std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT 00137 __attribute__((__externally_visible__)); 00138 void operator delete(void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT 00139 __attribute__((__externally_visible__)); 00140 void operator delete[](void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT 00141 __attribute__((__externally_visible__)); 00142 #if __cpp_aligned_new 00143 void* operator new(std::size_t, std::align_val_t) 00144 __attribute__((__externally_visible__)); 00145 void* operator new(std::size_t, std::align_val_t, const std::nothrow_t&) 00146 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 00147 void operator delete(void*, std::align_val_t) 00148 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 00149 void operator delete(void*, std::align_val_t, const std::nothrow_t&) 00150 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 00151 void* operator new[](std::size_t, std::align_val_t) 00152 __attribute__((__externally_visible__)); 00153 void* operator new[](std::size_t, std::align_val_t, const std::nothrow_t&) 00154 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 00155 void operator delete[](void*, std::align_val_t) 00156 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 00157 void operator delete[](void*, std::align_val_t, const std::nothrow_t&) 00158 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 00159 #if __cpp_sized_deallocation 00160 void operator delete(void*, std::size_t, std::align_val_t) 00161 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 00162 void operator delete[](void*, std::size_t, std::align_val_t) 00163 _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); 00164 #endif // __cpp_sized_deallocation 00165 #endif // __cpp_aligned_new 00166 00167 // Default placement versions of operator new. 00168 inline void* operator new(std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT 00169 { return __p; } 00170 inline void* operator new[](std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT 00171 { return __p; } 00172 00173 // Default placement versions of operator delete. 00174 inline void operator delete (void*, void*) _GLIBCXX_USE_NOEXCEPT { } 00175 inline void operator delete[](void*, void*) _GLIBCXX_USE_NOEXCEPT { } 00176 //@} 00177 } // extern "C++" 00178 00179 #if __cplusplus >= 201703L 00180 #if __GNUC__ >= 7 00181 # define _GLIBCXX_HAVE_BUILTIN_LAUNDER 1 00182 #elif defined __has_builtin 00183 // For non-GNU compilers: 00184 # if __has_builtin(__builtin_launder) 00185 # define _GLIBCXX_HAVE_BUILTIN_LAUNDER 1 00186 # endif 00187 #endif 00188 00189 #ifdef _GLIBCXX_HAVE_BUILTIN_LAUNDER 00190 namespace std 00191 { 00192 #define __cpp_lib_launder 201606 00193 /// Pointer optimization barrier [ptr.launder] 00194 template<typename _Tp> 00195 [[nodiscard]] constexpr _Tp* 00196 launder(_Tp* __p) noexcept 00197 { return __builtin_launder(__p); } 00198 00199 // The program is ill-formed if T is a function type or 00200 // (possibly cv-qualified) void. 00201 00202 template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM> 00203 void launder(_Ret (*)(_Args...) _GLIBCXX_NOEXCEPT_QUAL) = delete; 00204 template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM> 00205 void launder(_Ret (*)(_Args......) _GLIBCXX_NOEXCEPT_QUAL) = delete; 00206 00207 void launder(void*) = delete; 00208 void launder(const void*) = delete; 00209 void launder(volatile void*) = delete; 00210 void launder(const volatile void*) = delete; 00211 } 00212 #endif // _GLIBCXX_HAVE_BUILTIN_LAUNDER 00213 #undef _GLIBCXX_HAVE_BUILTIN_LAUNDER 00214 #endif // C++17 00215 00216 #pragma GCC visibility pop 00217 00218 #endif