libstdc++-v3/libsupc++/new

   1 // The -*- C++ -*- dynamic memory management header.
   2
   3 // Copyright (C) 1994-2016 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  *  http://gcc.gnu.org/onlinedocs/libstdc++/18_support/howto.html#4 for more.
  32  */
  33
  34 #ifndef _NEW
  35 #define _NEW
  36
  37 #pragma GCC system_header
  38
  39 #include <bits/c++config.h>
  40 #include <exception>
  41
  42 #pragma GCC visibility push(default)
  43
  44 extern "C++" {
  45
  46 namespace std
  47 {
  48   /**
  49    *  @brief  Exception possibly thrown by @c new.
  50    *  @ingroup exceptions
  51    *
  52    *  @c bad_alloc (or classes derived from it) is used to report allocation
  53    *  errors from the throwing forms of @c new.  */
  54   class bad_alloc : public exception
  55   {
  56   public:
  57     bad_alloc() throw() { }
  58
  59     // This declaration is not useless:
  60     // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
  61     virtual ~bad_alloc() throw();
  62
  63     // See comment in eh_exception.cc.
  64     virtual const char* what() const throw();
  65   };
  66
  67 #if __cplusplus >= 201103L
  68   class bad_array_new_length : public bad_alloc
  69   {
  70   public:
  71     bad_array_new_length() throw() { };
  72
  73     // This declaration is not useless:
  74     // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
  75     virtual ~bad_array_new_length() throw();
  76
  77     // See comment in eh_exception.cc.
  78     virtual const char* what() const throw();
  79   };
  80 #endif
  81
  82 #if __cpp_aligned_new
  83   enum class align_val_t: size_t {};
  84 #endif
  85
  86   struct nothrow_t
  87   {
  88 #if __cplusplus >= 201103L
  89     explicit nothrow_t() = default;
  90 #endif
  91   };
  92
  93   extern const nothrow_t nothrow;
  94
  95   /** If you write your own error handler to be called by @c new, it must
  96    *  be of this type.  */
  97   typedef void (*new_handler)();
  98
  99   /// Takes a replacement handler as the argument, returns the
 100   /// previous handler.
 101   new_handler set_new_handler(new_handler) throw();
 102
 103 #if __cplusplus >= 201103L
 104   /// Return the current new handler.
 105   new_handler get_new_handler() noexcept;
 106 #endif
 107 } // namespace std
 108
 109 //@{
 110 /** These are replaceable signatures:
 111  *  - normal single new and delete (no arguments, throw @c bad_alloc on error)
 112  *  - normal array new and delete (same)
 113  *  - @c nothrow single new and delete (take a @c nothrow argument, return
 114  *    @c NULL on error)
 115  *  - @c nothrow array new and delete (same)
 116  *
 117  *  Placement new and delete signatures (take a memory address argument,
 118  *  does nothing) may not be replaced by a user's program.
 119 */
 120 void* operator new(std::size_t) _GLIBCXX_THROW (std::bad_alloc)
 121   __attribute__((__externally_visible__));
 122 void* operator new[](std::size_t) _GLIBCXX_THROW (std::bad_alloc)
 123   __attribute__((__externally_visible__));
 124 void operator delete(void*) _GLIBCXX_USE_NOEXCEPT
 125   __attribute__((__externally_visible__));
 126 void operator delete[](void*) _GLIBCXX_USE_NOEXCEPT
 127   __attribute__((__externally_visible__));
 128 #if __cpp_sized_deallocation
 129 void operator delete(void*, std::size_t) _GLIBCXX_USE_NOEXCEPT
 130   __attribute__((__externally_visible__));
 131 void operator delete[](void*, std::size_t) _GLIBCXX_USE_NOEXCEPT
 132   __attribute__((__externally_visible__));
 133 #endif
 134 void* operator new(std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
 135   __attribute__((__externally_visible__));
 136 void* operator new[](std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
 137   __attribute__((__externally_visible__));
 138 void operator delete(void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
 139   __attribute__((__externally_visible__));
 140 void operator delete[](void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
 141   __attribute__((__externally_visible__));
 142 #if __cpp_aligned_new
 143 void* operator new(std::size_t, std::align_val_t)
 144   __attribute__((__externally_visible__));
 145 void* operator new(std::size_t, std::align_val_t, const std::nothrow_t&)
 146   _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
 147 void operator delete(void*, std::align_val_t)
 148   _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
 149 void operator delete(void*, std::align_val_t, const std::nothrow_t&)
 150   _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
 151 void* operator new[](std::size_t, std::align_val_t)
 152   __attribute__((__externally_visible__));
 153 void* operator new[](std::size_t, std::align_val_t, const std::nothrow_t&)
 154   _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
 155 void operator delete[](void*, std::align_val_t)
 156   _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
 157 void operator delete[](void*, std::align_val_t, const std::nothrow_t&)
 158   _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
 159 #if __cpp_sized_deallocation
 160 void operator delete(void*, std::size_t, std::align_val_t)
 161   _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
 162 void operator delete[](void*, std::size_t, std::align_val_t)
 163   _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
 164 #endif // __cpp_sized_deallocation
 165 #endif // __cpp_aligned_new
 166
 167 // Default placement versions of operator new.
 168 inline void* operator new(std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT
 169 { return __p; }
 170 inline void* operator new[](std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT
 171 { return __p; }
 172
 173 // Default placement versions of operator delete.
 174 inline void operator delete  (void*, void*) _GLIBCXX_USE_NOEXCEPT { }
 175 inline void operator delete[](void*, void*) _GLIBCXX_USE_NOEXCEPT { }
 176 //@}
 177 } // extern "C++"
 178
 179 #pragma GCC visibility pop
 180
 181 #endif