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 21 inline 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 30 static 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 116 117 static 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