1// The -*- C++ -*- dynamic memory management header.
2
3// Copyright (C) 1994-2018 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
44extern "C++" {
45
46namespace 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*/
120void* operator new(std::size_t) _GLIBCXX_THROW (std::bad_alloc)
121  __attribute__((__externally_visible__));
122void* operator new[](std::size_t) _GLIBCXX_THROW (std::bad_alloc)
123  __attribute__((__externally_visible__));
124void operator delete(void*) _GLIBCXX_USE_NOEXCEPT
125  __attribute__((__externally_visible__));
126void operator delete[](void*) _GLIBCXX_USE_NOEXCEPT
127  __attribute__((__externally_visible__));
128#if __cpp_sized_deallocation
129void operator delete(void*, std::size_t) _GLIBCXX_USE_NOEXCEPT
130  __attribute__((__externally_visible__));
131void operator delete[](void*, std::size_t) _GLIBCXX_USE_NOEXCEPT
132  __attribute__((__externally_visible__));
133#endif
134void* operator new(std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
135  __attribute__((__externally_visible__));
136void* operator new[](std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
137  __attribute__((__externally_visible__));
138void operator delete(void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
139  __attribute__((__externally_visible__));
140void operator delete[](void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
141  __attribute__((__externally_visible__));
142#if __cpp_aligned_new
143void* operator new(std::size_t, std::align_val_t)
144  __attribute__((__externally_visible__));
145void* operator new(std::size_t, std::align_val_t, const std::nothrow_t&)
146  _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
147void operator delete(void*, std::align_val_t)
148  _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
149void operator delete(void*, std::align_val_t, const std::nothrow_t&)
150  _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
151void* operator new[](std::size_t, std::align_val_t)
152  __attribute__((__externally_visible__));
153void* operator new[](std::size_t, std::align_val_t, const std::nothrow_t&)
154  _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
155void operator delete[](void*, std::align_val_t)
156  _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
157void operator delete[](void*, std::align_val_t, const std::nothrow_t&)
158  _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
159#if __cpp_sized_deallocation
160void operator delete(void*, std::size_t, std::align_val_t)
161  _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
162void 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.
168inline void* operator new(std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT
169{ return __p; }
170inline void* operator new[](std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT
171{ return __p; }
172
173// Default placement versions of operator delete.
174inline void operator delete  (void*, void*) _GLIBCXX_USE_NOEXCEPT { }
175inline void operator delete[](void*, void*) _GLIBCXX_USE_NOEXCEPT { }
176//@}
177} // extern "C++"
178
179#if __cplusplus >= 201703L
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
190namespace std
191{
192#define __cpp_lib_launder 201606
193  /// Pointer optimization barrier [ptr.launder]
194  template<typename _Tp>
195    [[nodiscard]] 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
219