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1 : // The -*- C++ -*- dynamic memory management header.
2 :
3 : // Copyright (C) 1994-2024 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 : #define __glibcxx_want_launder
44 : #define __glibcxx_want_hardware_interference_size
45 : #define __glibcxx_want_destroying_delete
46 : #include <bits/version.h>
47 :
48 : #pragma GCC visibility push(default)
49 :
50 : extern "C++" {
51 :
52 : namespace std
53 : {
54 : /**
55 : * @brief Exception possibly thrown by @c new.
56 : * @ingroup exceptions
57 : *
58 : * @c bad_alloc (or classes derived from it) is used to report allocation
59 : * errors from the throwing forms of @c new. */
60 : class bad_alloc : public exception
61 : {
62 : public:
63 : bad_alloc() throw() { }
64 :
65 : #if __cplusplus >= 201103L
66 : bad_alloc(const bad_alloc&) = default;
67 : bad_alloc& operator=(const bad_alloc&) = default;
68 : #endif
69 :
70 : // This declaration is not useless:
71 : // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
72 : virtual ~bad_alloc() throw();
73 :
74 : // See comment in eh_exception.cc.
75 : virtual const char* what() const throw();
76 : };
77 :
78 : #if __cplusplus >= 201103L
79 : class bad_array_new_length : public bad_alloc
80 : {
81 : public:
82 : bad_array_new_length() throw() { }
83 :
84 : // This declaration is not useless:
85 : // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
86 : virtual ~bad_array_new_length() throw();
87 :
88 : // See comment in eh_exception.cc.
89 : virtual const char* what() const throw();
90 : };
91 : #endif
92 :
93 : #if __cpp_aligned_new
94 : enum class align_val_t: size_t {};
95 : #endif
96 :
97 : struct nothrow_t
98 : {
99 : #if __cplusplus >= 201103L
100 : explicit nothrow_t() = default;
101 : #endif
102 : };
103 :
104 : extern const nothrow_t nothrow;
105 :
106 : /** If you write your own error handler to be called by @c new, it must
107 : * be of this type. */
108 : typedef void (*new_handler)();
109 :
110 : /// Takes a replacement handler as the argument, returns the
111 : /// previous handler.
112 : new_handler set_new_handler(new_handler) throw();
113 :
114 : #if __cplusplus >= 201103L
115 : /// Return the current new handler.
116 : new_handler get_new_handler() noexcept;
117 : #endif
118 : } // namespace std
119 :
120 : //@{
121 : /** These are replaceable signatures:
122 : * - normal single new and delete (no arguments, throw @c bad_alloc on error)
123 : * - normal array new and delete (same)
124 : * - @c nothrow single new and delete (take a @c nothrow argument, return
125 : * @c NULL on error)
126 : * - @c nothrow array new and delete (same)
127 : *
128 : * Placement new and delete signatures (take a memory address argument,
129 : * does nothing) may not be replaced by a user's program.
130 : */
131 : _GLIBCXX_NODISCARD void* operator new(std::size_t) _GLIBCXX_THROW (std::bad_alloc)
132 : __attribute__((__externally_visible__));
133 : _GLIBCXX_NODISCARD void* operator new[](std::size_t) _GLIBCXX_THROW (std::bad_alloc)
134 : __attribute__((__externally_visible__));
135 : void operator delete(void*) _GLIBCXX_USE_NOEXCEPT
136 : __attribute__((__externally_visible__));
137 : void operator delete[](void*) _GLIBCXX_USE_NOEXCEPT
138 : __attribute__((__externally_visible__));
139 : #if __cpp_sized_deallocation
140 : void operator delete(void*, std::size_t) _GLIBCXX_USE_NOEXCEPT
141 : __attribute__((__externally_visible__));
142 : void operator delete[](void*, std::size_t) _GLIBCXX_USE_NOEXCEPT
143 : __attribute__((__externally_visible__));
144 : #endif
145 : _GLIBCXX_NODISCARD void* operator new(std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
146 : __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));
147 : _GLIBCXX_NODISCARD void* operator new[](std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
148 : __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));
149 : void operator delete(void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
150 : __attribute__((__externally_visible__));
151 : void operator delete[](void*, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
152 : __attribute__((__externally_visible__));
153 : #if __cpp_aligned_new
154 : _GLIBCXX_NODISCARD void* operator new(std::size_t, std::align_val_t)
155 : __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));
156 : _GLIBCXX_NODISCARD void* operator new(std::size_t, std::align_val_t, const std::nothrow_t&)
157 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));
158 : void operator delete(void*, std::align_val_t)
159 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
160 : void operator delete(void*, std::align_val_t, const std::nothrow_t&)
161 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
162 : _GLIBCXX_NODISCARD void* operator new[](std::size_t, std::align_val_t)
163 : __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));
164 : _GLIBCXX_NODISCARD void* operator new[](std::size_t, std::align_val_t, const std::nothrow_t&)
165 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));
166 : void operator delete[](void*, std::align_val_t)
167 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
168 : void operator delete[](void*, std::align_val_t, const std::nothrow_t&)
169 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
170 : #if __cpp_sized_deallocation
171 : void operator delete(void*, std::size_t, std::align_val_t)
172 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
173 : void operator delete[](void*, std::size_t, std::align_val_t)
174 : _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));
175 : #endif // __cpp_sized_deallocation
176 : #endif // __cpp_aligned_new
177 :
178 : // Default placement versions of operator new.
179 141458 : _GLIBCXX_NODISCARD inline void* operator new(std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT
180 141458 : { return __p; }
181 : _GLIBCXX_NODISCARD inline void* operator new[](std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT
182 : { return __p; }
183 :
184 : // Default placement versions of operator delete.
185 0 : inline void operator delete (void*, void*) _GLIBCXX_USE_NOEXCEPT { }
186 : inline void operator delete[](void*, void*) _GLIBCXX_USE_NOEXCEPT { }
187 : //@}
188 : } // extern "C++"
189 :
190 : #if __cplusplus >= 201703L
191 : namespace std
192 : {
193 : #ifdef __cpp_lib_launder // C++ >= 17 && HAVE_BUILTIN_LAUNDER
194 : /// Pointer optimization barrier [ptr.launder]
195 : template<typename _Tp>
196 : [[nodiscard]] constexpr _Tp*
197 : launder(_Tp* __p) noexcept
198 : { return __builtin_launder(__p); }
199 :
200 : // The program is ill-formed if T is a function type or
201 : // (possibly cv-qualified) void.
202 :
203 : template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM>
204 : void launder(_Ret (*)(_Args...) _GLIBCXX_NOEXCEPT_QUAL) = delete;
205 : template<typename _Ret, typename... _Args _GLIBCXX_NOEXCEPT_PARM>
206 : void launder(_Ret (*)(_Args......) _GLIBCXX_NOEXCEPT_QUAL) = delete;
207 :
208 : void launder(void*) = delete;
209 : void launder(const void*) = delete;
210 : void launder(volatile void*) = delete;
211 : void launder(const volatile void*) = delete;
212 : #endif // __cpp_lib_launder
213 :
214 : #ifdef __cpp_lib_hardware_interference_size // C++ >= 17 && defined(gcc_dest_sz)
215 : inline constexpr size_t hardware_destructive_interference_size = __GCC_DESTRUCTIVE_SIZE;
216 : inline constexpr size_t hardware_constructive_interference_size = __GCC_CONSTRUCTIVE_SIZE;
217 : #endif // __cpp_lib_hardware_interference_size
218 : }
219 : #endif // C++17
220 :
221 : // Emitted despite the FTM potentially being undefined.
222 : #if __cplusplus > 201703L
223 : namespace std
224 : {
225 : /// Tag type used to declare a class-specific operator delete that can
226 : /// invoke the destructor before deallocating the memory.
227 : struct destroying_delete_t
228 : {
229 : explicit destroying_delete_t() = default;
230 : };
231 : /// Tag variable of type destroying_delete_t.
232 : inline constexpr destroying_delete_t destroying_delete{};
233 : }
234 : #endif // C++20
235 :
236 : #pragma GCC visibility pop
237 :
238 : #endif
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