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
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