libstdc++
new
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1 // The -*- C++ -*- dynamic memory management header.
2 
3 // Copyright (C) 1994-2017 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.
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 #if __cplusplus > 201402L
180 #if __GNUC__ >= 7
181 # define _GLIBCXX_HAVE_BUILTIN_LAUNDER 1
182 #elif defined __has_builtin
183 // For non-GNU compilers:
184 # if __has_builtin(__builtin_launder)
185 # define _GLIBCXX_HAVE_BUILTIN_LAUNDER 1
186 # endif
187 #endif
188 
189 #ifdef _GLIBCXX_HAVE_BUILTIN_LAUNDER
190 namespace std
191 {
192 #define __cpp_lib_launder 201606
193  /// Pointer optimization barrier [ptr.launder]
194  template<typename _Tp>
195  constexpr _Tp*
196  launder(_Tp* __p) noexcept
197  { return __builtin_launder(__p); }
198 
199  // The program is ill-formed if T is a function type or
200  // (possibly cv-qualified) void.
201 
202  template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM>
203  void launder(_Ret (*)(_Args...) _GLIBCXX_NOEXCEPT_QUAL) = delete;
204  template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM>
205  void launder(_Ret (*)(_Args......) _GLIBCXX_NOEXCEPT_QUAL) = delete;
206 
207  void launder(void*) = delete;
208  void launder(const void*) = delete;
209  void launder(volatile void*) = delete;
210  void launder(const volatile void*) = delete;
211 }
212 #endif // _GLIBCXX_HAVE_BUILTIN_LAUNDER
213 #undef _GLIBCXX_HAVE_BUILTIN_LAUNDER
214 #endif // C++17
215 
216 #pragma GCC visibility pop
217 
218 #endif
Exception possibly thrown by new.bad_alloc (or classes derived from it) is used to report allocation ...
Definition: new:54
new_handler get_new_handler() noexcept
Return the current new handler.
ISO C++ entities toplevel namespace is std.
new_handler set_new_handler(new_handler)
Takes a replacement handler as the argument, returns the previous handler.
Base class for all library exceptions.
Definition: exception.h:60
void(* new_handler)()
Definition: new:97
virtual const char * what() const