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1 : // The -*- C++ -*- dynamic memory management header.
2 :
3 : // Copyright (C) 1994-2022 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 : * https://gcc.gnu.org/onlinedocs/libstdc++/manual/dynamic_memory.html
32 : * for more.
33 : */
34 :
35 : #ifndef _NEW
36 : #define _NEW
37 :
38 : #pragma GCC system_header
39 :
40 : #include <bits/c++config.h>
41 : #include <bits/exception.h>
42 :
43 : #pragma GCC visibility push(default)
44 :
45 : extern "C++" {
46 :
47 : namespace std
48 : {
49 : /**
50 : * @brief Exception possibly thrown by @c new.
51 : * @ingroup exceptions
52 : *
53 : * @c bad_alloc (or classes derived from it) is used to report allocation
54 : * errors from the throwing forms of @c new. */
55 : class bad_alloc : public exception
56 : {
57 : public:
58 : bad_alloc() throw() { }
59 :
60 : #if __cplusplus >= 201103L
61 : bad_alloc(const bad_alloc&) = default;
62 : bad_alloc& operator=(const bad_alloc&) = default;
63 : #endif
64 :
65 : // This declaration is not useless:
66 : // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
67 : virtual ~bad_alloc() throw();
68 :
69 : // See comment in eh_exception.cc.
70 : virtual const char* what() const throw();
71 : };
72 :
73 : #if __cplusplus >= 201103L
74 : class bad_array_new_length : public bad_alloc
75 : {
76 : public:
77 : bad_array_new_length() throw() { }
78 :
79 : // This declaration is not useless:
80 : // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
81 : virtual ~bad_array_new_length() throw();
82 :
83 : // See comment in eh_exception.cc.
84 : virtual const char* what() const throw();
85 : };
86 : #endif
87 :
88 : #if __cpp_aligned_new
89 : enum class align_val_t: size_t {};
90 : #endif
91 :
92 : struct nothrow_t
93 : {
94 : #if __cplusplus >= 201103L
95 : explicit nothrow_t() = default;
96 : #endif
97 : };
98 :
99 : extern const nothrow_t nothrow;
100 :
101 : /** If you write your own error handler to be called by @c new, it must
102 : * be of this type. */
103 : typedef void (*new_handler)();
104 :
105 : /// Takes a replacement handler as the argument, returns the
106 : /// previous handler.
107 : new_handler set_new_handler(new_handler) throw();
108 :
109 : #if __cplusplus >= 201103L
110 : /// Return the current new handler.
111 : new_handler get_new_handler() noexcept;
112 : #endif
113 : } // namespace std
114 :
115 : //@{
116 : /** These are replaceable signatures:
117 : * - normal single new and delete (no arguments, throw @c bad_alloc on error)
118 : * - normal array new and delete (same)
119 : * - @c nothrow single new and delete (take a @c nothrow argument, return
120 : * @c NULL on error)
121 : * - @c nothrow array new and delete (same)
122 : *
123 : * Placement new and delete signatures (take a memory address argument,
124 : * does nothing) may not be replaced by a user's program.
125 : */
126 : _GLIBCXX_NODISCARD void* operator new(std::size_t) _GLIBCXX_THROW (std::bad_alloc)
127 : __attribute__((__externally_visible__));
128 : _GLIBCXX_NODISCARD void* operator new[](std::size_t) _GLIBCXX_THROW (std::bad_alloc)
129 : __attribute__((__externally_visible__));
130 : void operator delete(void*) _GLIBCXX_USE_NOEXCEPT
131 : __attribute__((__externally_visible__));
132 : void operator delete[](void*) _GLIBCXX_USE_NOEXCEPT
133 : __attribute__((__externally_visible__));
134 : #if __cpp_sized_deallocation
135 : void operator delete(void*, std::size_t) _GLIBCXX_USE_NOEXCEPT
136 : __attribute__((__externally_visible__));
137 : void operator delete[](void*, std::size_t) _GLIBCXX_USE_NOEXCEPT
138 : __attribute__((__externally_visible__));
139 : #endif
140 : _GLIBCXX_NODISCARD void* operator new(std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
141 : __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));
142 : _GLIBCXX_NODISCARD void* operator new[](std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
143 : __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));
144 : void operator delete(void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
145 : __attribute__((__externally_visible__));
146 : void operator delete[](void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
147 : __attribute__((__externally_visible__));
148 : #if __cpp_aligned_new
149 : _GLIBCXX_NODISCARD void* operator new(std::size_t, std::align_val_t)
150 : __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));
151 : _GLIBCXX_NODISCARD void* operator new(std::size_t, std::align_val_t, const std::nothrow_t&)
152 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));
153 : void operator delete(void*, std::align_val_t)
154 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
155 : void operator delete(void*, std::align_val_t, const std::nothrow_t&)
156 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
157 : _GLIBCXX_NODISCARD void* operator new[](std::size_t, std::align_val_t)
158 : __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));
159 : _GLIBCXX_NODISCARD void* operator new[](std::size_t, std::align_val_t, const std::nothrow_t&)
160 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));
161 : void operator delete[](void*, std::align_val_t)
162 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
163 : void operator delete[](void*, std::align_val_t, const std::nothrow_t&)
164 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
165 : #if __cpp_sized_deallocation
166 : void operator delete(void*, std::size_t, std::align_val_t)
167 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
168 : void operator delete[](void*, std::size_t, std::align_val_t)
169 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
170 : #endif // __cpp_sized_deallocation
171 : #endif // __cpp_aligned_new
172 :
173 : // Default placement versions of operator new.
174 8795931 : _GLIBCXX_NODISCARD inline void* operator new(std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT
175 8795931 : { return __p; }
176 : _GLIBCXX_NODISCARD inline void* operator new[](std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT
177 : { return __p; }
178 :
179 : // Default placement versions of operator delete.
180 : inline void operator delete (void*, void*) _GLIBCXX_USE_NOEXCEPT { }
181 : inline void operator delete[](void*, void*) _GLIBCXX_USE_NOEXCEPT { }
182 : //@}
183 : } // extern "C++"
184 :
185 : #if __cplusplus >= 201703L
186 : namespace std
187 : {
188 : #ifdef _GLIBCXX_HAVE_BUILTIN_LAUNDER
189 : #define __cpp_lib_launder 201606L
190 : /// Pointer optimization barrier [ptr.launder]
191 : template<typename _Tp>
192 : [[nodiscard]] constexpr _Tp*
193 : launder(_Tp* __p) noexcept
194 : { return __builtin_launder(__p); }
195 :
196 : // The program is ill-formed if T is a function type or
197 : // (possibly cv-qualified) void.
198 :
199 : template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM>
200 : void launder(_Ret (*)(_Args...) _GLIBCXX_NOEXCEPT_QUAL) = delete;
201 : template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM>
202 : void launder(_Ret (*)(_Args......) _GLIBCXX_NOEXCEPT_QUAL) = delete;
203 :
204 : void launder(void*) = delete;
205 : void launder(const void*) = delete;
206 : void launder(volatile void*) = delete;
207 : void launder(const volatile void*) = delete;
208 : #endif // _GLIBCXX_HAVE_BUILTIN_LAUNDER
209 :
210 : #ifdef __GCC_DESTRUCTIVE_SIZE
211 : # define __cpp_lib_hardware_interference_size 201703L
212 : inline constexpr size_t hardware_destructive_interference_size = __GCC_DESTRUCTIVE_SIZE;
213 : inline constexpr size_t hardware_constructive_interference_size = __GCC_CONSTRUCTIVE_SIZE;
214 : #endif // __GCC_DESTRUCTIVE_SIZE
215 : }
216 : #endif // C++17
217 :
218 : #if __cplusplus > 201703L
219 : namespace std
220 : {
221 : /// Tag type used to declare a class-specific operator delete that can
222 : /// invoke the destructor before deallocating the memory.
223 : struct destroying_delete_t
224 : {
225 : explicit destroying_delete_t() = default;
226 : };
227 : /// Tag variable of type destroying_delete_t.
228 : inline constexpr destroying_delete_t destroying_delete{};
229 : }
230 : // Only define the feature test macro if the compiler supports the feature:
231 : #if __cpp_impl_destroying_delete
232 : # define __cpp_lib_destroying_delete 201806L
233 : #endif
234 : #endif // C++20
235 :
236 : #pragma GCC visibility pop
237 :
238 : #endif
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