1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "include/overridable_function.h"
10#include <__assert>
11#include <__memory/aligned_alloc.h>
12#include <cstddef>
13#include <cstdlib>
14#include <new>
15
16#if !defined(__GLIBCXX__) && !defined(_LIBCPP_ABI_VCRUNTIME)
17
18// The code below is copied as-is into libc++abi's libcxxabi/src/stdlib_new_delete.cpp
19// file. The version in this file is the canonical one.
20
21inline void __throw_bad_alloc_shim() { std::__throw_bad_alloc(); }
22
23# define _LIBCPP_ASSERT_SHIM(expr, str) _LIBCPP_ASSERT(expr, str)
24
25// ------------------ BEGIN COPY ------------------
26// Implement all new and delete operators as weak definitions
27// in this shared library, so that they can be overridden by programs
28// that define non-weak copies of the functions.
29
30static void* operator_new_impl(std::size_t size) {
31 if (size == 0)
32 size = 1;
33 void* p;
34 while ((p = std::malloc(size)) == nullptr) {
35 // If malloc fails and there is a new_handler,
36 // call it to try free up memory.
37 std::new_handler nh = std::get_new_handler();
38 if (nh)
39 nh();
40 else
41 break;
42 }
43 return p;
44}
45
46_LIBCPP_OVERRIDABLE_FUNCTION(void*, operator new, (std::size_t size)) _THROW_BAD_ALLOC {
47 void* p = operator_new_impl(size);
48 if (p == nullptr)
49 __throw_bad_alloc_shim();
50 return p;
51}
52
53_LIBCPP_WEAK void* operator new(size_t size, const std::nothrow_t&) noexcept {
54# if !_LIBCPP_HAS_EXCEPTIONS
55# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
56 _LIBCPP_ASSERT_SHIM(
57 (!std::__is_function_overridden < void*(std::size_t), &operator new>()),
58 "libc++ was configured with exceptions disabled and `operator new(size_t)` has been overridden, "
59 "but `operator new(size_t, nothrow_t)` has not been overridden. This is problematic because "
60 "`operator new(size_t, nothrow_t)` must call `operator new(size_t)`, which will terminate in case "
61 "it fails to allocate, making it impossible for `operator new(size_t, nothrow_t)` to fulfill its "
62 "contract (since it should return nullptr upon failure). Please make sure you override "
63 "`operator new(size_t, nothrow_t)` as well.");
64# endif
65
66 return operator_new_impl(size);
67# else
68 void* p = nullptr;
69 try {
70 p = ::operator new(size);
71 } catch (...) {
72 }
73 return p;
74# endif
75}
76
77_LIBCPP_OVERRIDABLE_FUNCTION(void*, operator new[], (size_t size)) _THROW_BAD_ALLOC { return ::operator new(size); }
78
79_LIBCPP_WEAK void* operator new[](size_t size, const std::nothrow_t&) noexcept {
80# if !_LIBCPP_HAS_EXCEPTIONS
81# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
82 _LIBCPP_ASSERT_SHIM(
83 (!std::__is_function_overridden < void*(std::size_t), &operator new[]>()),
84 "libc++ was configured with exceptions disabled and `operator new[](size_t)` has been overridden, "
85 "but `operator new[](size_t, nothrow_t)` has not been overridden. This is problematic because "
86 "`operator new[](size_t, nothrow_t)` must call `operator new[](size_t)`, which will terminate in case "
87 "it fails to allocate, making it impossible for `operator new[](size_t, nothrow_t)` to fulfill its "
88 "contract (since it should return nullptr upon failure). Please make sure you override "
89 "`operator new[](size_t, nothrow_t)` as well.");
90# endif
91
92 return operator_new_impl(size);
93# else
94 void* p = nullptr;
95 try {
96 p = ::operator new[](size);
97 } catch (...) {
98 }
99 return p;
100# endif
101}
102
103_LIBCPP_WEAK void operator delete(void* ptr) noexcept { std::free(ptr); }
104
105_LIBCPP_WEAK void operator delete(void* ptr, const std::nothrow_t&) noexcept { ::operator delete(ptr); }
106
107_LIBCPP_WEAK void operator delete(void* ptr, size_t) noexcept { ::operator delete(ptr); }
108
109_LIBCPP_WEAK void operator delete[](void* ptr) noexcept { ::operator delete(ptr); }
110
111_LIBCPP_WEAK void operator delete[](void* ptr, const std::nothrow_t&) noexcept { ::operator delete[](ptr); }
112
113_LIBCPP_WEAK void operator delete[](void* ptr, size_t) noexcept { ::operator delete[](ptr); }
114
115# if _LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION
116
117static void* operator_new_aligned_impl(std::size_t size, std::align_val_t alignment) {
118 if (size == 0)
119 size = 1;
120 if (static_cast<size_t>(alignment) < sizeof(void*))
121 alignment = std::align_val_t(sizeof(void*));
122
123 // Try allocating memory. If allocation fails and there is a new_handler,
124 // call it to try free up memory, and try again until it succeeds, or until
125 // the new_handler decides to terminate.
126 void* p;
127 while ((p = std::__libcpp_aligned_alloc(static_cast<std::size_t>(alignment), size)) == nullptr) {
128 std::new_handler nh = std::get_new_handler();
129 if (nh)
130 nh();
131 else
132 break;
133 }
134 return p;
135}
136
137_LIBCPP_OVERRIDABLE_FUNCTION(void*, operator new, (std::size_t size, std::align_val_t alignment)) _THROW_BAD_ALLOC {
138 void* p = operator_new_aligned_impl(size, alignment);
139 if (p == nullptr)
140 __throw_bad_alloc_shim();
141 return p;
142}
143
144_LIBCPP_WEAK void* operator new(size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept {
145# if !_LIBCPP_HAS_EXCEPTIONS
146# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
147 _LIBCPP_ASSERT_SHIM(
148 (!std::__is_function_overridden < void*(std::size_t, std::align_val_t), &operator new>()),
149 "libc++ was configured with exceptions disabled and `operator new(size_t, align_val_t)` has been overridden, "
150 "but `operator new(size_t, align_val_t, nothrow_t)` has not been overridden. This is problematic because "
151 "`operator new(size_t, align_val_t, nothrow_t)` must call `operator new(size_t, align_val_t)`, which will "
152 "terminate in case it fails to allocate, making it impossible for `operator new(size_t, align_val_t, nothrow_t)` "
153 "to fulfill its contract (since it should return nullptr upon failure). Please make sure you override "
154 "`operator new(size_t, align_val_t, nothrow_t)` as well.");
155# endif
156
157 return operator_new_aligned_impl(size, alignment);
158# else
159 void* p = nullptr;
160 try {
161 p = ::operator new(size, alignment);
162 } catch (...) {
163 }
164 return p;
165# endif
166}
167
168_LIBCPP_OVERRIDABLE_FUNCTION(void*, operator new[], (size_t size, std::align_val_t alignment)) _THROW_BAD_ALLOC {
169 return ::operator new(size, alignment);
170}
171
172_LIBCPP_WEAK void* operator new[](size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept {
173# if !_LIBCPP_HAS_EXCEPTIONS
174# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
175 _LIBCPP_ASSERT_SHIM(
176 (!std::__is_function_overridden < void*(std::size_t, std::align_val_t), &operator new[]>()),
177 "libc++ was configured with exceptions disabled and `operator new[](size_t, align_val_t)` has been overridden, "
178 "but `operator new[](size_t, align_val_t, nothrow_t)` has not been overridden. This is problematic because "
179 "`operator new[](size_t, align_val_t, nothrow_t)` must call `operator new[](size_t, align_val_t)`, which will "
180 "terminate in case it fails to allocate, making it impossible for `operator new[](size_t, align_val_t, "
181 "nothrow_t)` to fulfill its contract (since it should return nullptr upon failure). Please make sure you "
182 "override `operator new[](size_t, align_val_t, nothrow_t)` as well.");
183# endif
184
185 return operator_new_aligned_impl(size, alignment);
186# else
187 void* p = nullptr;
188 try {
189 p = ::operator new[](size, alignment);
190 } catch (...) {
191 }
192 return p;
193# endif
194}
195
196_LIBCPP_WEAK void operator delete(void* ptr, std::align_val_t) noexcept { std::__libcpp_aligned_free(ptr); }
197
198_LIBCPP_WEAK void operator delete(void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept {
199 ::operator delete(ptr, alignment);
200}
201
202_LIBCPP_WEAK void operator delete(void* ptr, size_t, std::align_val_t alignment) noexcept {
203 ::operator delete(ptr, alignment);
204}
205
206_LIBCPP_WEAK void operator delete[](void* ptr, std::align_val_t alignment) noexcept {
207 ::operator delete(ptr, alignment);
208}
209
210_LIBCPP_WEAK void operator delete[](void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept {
211 ::operator delete[](ptr, alignment);
212}
213
214_LIBCPP_WEAK void operator delete[](void* ptr, size_t, std::align_val_t alignment) noexcept {
215 ::operator delete[](ptr, alignment);
216}
217
218# endif // _LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION
219// ------------------ END COPY ------------------
220
221#endif // !__GLIBCXX__ && !_LIBCPP_ABI_VCRUNTIME
222

source code of libcxx/src/new.cpp