1 /* Replace operator new/new[], for GDB, the GNU debugger. 2 3 Copyright (C) 2016-2023 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program 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 of the License, or 10 (at your option) any later version. 11 12 This program 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 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 /* GCC does not understand __has_feature. */ 21 #if !defined(__has_feature) 22 # define __has_feature(x) 0 23 #endif 24 25 #if !__has_feature(address_sanitizer) && !defined(__SANITIZE_ADDRESS__) 26 #include "common-defs.h" 27 #include "host-defs.h" 28 #include <new> 29 30 /* These are declared in <new> starting C++14. Add these here to enable 31 compilation using C++11. */ 32 extern void operator delete (void *p, std::size_t) noexcept; 33 extern void operator delete[] (void *p, std::size_t) noexcept; 34 35 /* Override operator new / operator new[], in order to internal_error 36 on allocation failure and thus query the user for abort/core 37 dump/continue, just like xmalloc does. We don't do this from a 38 new-handler function instead (std::set_new_handler) because we want 39 to catch allocation errors from within global constructors too. 40 41 Skip overriding if building with -fsanitize=address though. 42 Address sanitizer wants to override operator new/delete too in 43 order to detect malloc+delete and new+free mismatches. Our 44 versions would mask out ASan's, with the result of losing that 45 useful mismatch detection. 46 47 Note that C++ implementations could either have their throw 48 versions call the nothrow versions (libstdc++), or the other way 49 around (clang/libc++). For that reason, we replace both throw and 50 nothrow variants and call malloc directly. */ 51 52 void * 53 operator new (std::size_t sz) 54 { 55 /* malloc (0) is unpredictable; avoid it. */ 56 if (sz == 0) 57 sz = 1; 58 59 void *p = malloc (sz); /* ARI: malloc */ 60 if (p == NULL) 61 { 62 /* If the user decides to continue debugging, throw a 63 gdb_quit_bad_alloc exception instead of a regular QUIT 64 gdb_exception. The former extends both std::bad_alloc and a 65 QUIT gdb_exception. This is necessary because operator new 66 can only ever throw std::bad_alloc, or something that extends 67 it. */ 68 try 69 { 70 malloc_failure (sz); 71 } 72 catch (gdb_exception &ex) 73 { 74 throw gdb_quit_bad_alloc (std::move (ex)); 75 } 76 } 77 return p; 78 } 79 80 void * 81 operator new (std::size_t sz, const std::nothrow_t&) noexcept 82 { 83 /* malloc (0) is unpredictable; avoid it. */ 84 if (sz == 0) 85 sz = 1; 86 return malloc (sz); /* ARI: malloc */ 87 } 88 89 void * 90 operator new[] (std::size_t sz) 91 { 92 return ::operator new (sz); 93 } 94 95 void* 96 operator new[] (std::size_t sz, const std::nothrow_t&) noexcept 97 { 98 return ::operator new (sz, std::nothrow); 99 } 100 101 /* Define also operators delete as one can LD_PRELOAD=libasan.so.* 102 without recompiling the program with -fsanitize=address and then one would 103 get false positive alloc-dealloc-mismatch (malloc vs operator delete []) 104 errors from AddressSanitizers. */ 105 106 void 107 operator delete (void *p) noexcept 108 { 109 free (p); 110 } 111 112 void 113 operator delete (void *p, const std::nothrow_t&) noexcept 114 { 115 return ::operator delete (p); 116 } 117 118 void 119 operator delete (void *p, std::size_t) noexcept 120 { 121 return ::operator delete (p, std::nothrow); 122 } 123 124 void 125 operator delete[] (void *p) noexcept 126 { 127 return ::operator delete (p); 128 } 129 130 void 131 operator delete[] (void *p, const std::nothrow_t&) noexcept 132 { 133 return ::operator delete (p, std::nothrow); 134 } 135 136 void 137 operator delete[] (void *p, std::size_t) noexcept 138 { 139 return ::operator delete[] (p, std::nothrow); 140 } 141 142 #endif 143