libstdc++
new
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00001 // The -*- C++ -*- dynamic memory management header.
00002 
00003 // Copyright (C) 1994-2017 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 > 201402L
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     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