1 //===-- Safe nullptr check --------------------------------------*- C++ -*-===// 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 #ifndef LLVM_LIBC_SRC___SUPPORT_MACROS_NULL_CHECK_H 10 #define LLVM_LIBC_SRC___SUPPORT_MACROS_NULL_CHECK_H 11 12 #include "src/__support/macros/config.h" 13 #include "src/__support/macros/optimization.h" 14 #include "src/__support/macros/sanitizer.h" 15 16 #if defined(LIBC_ADD_NULL_CHECKS) && !defined(LIBC_HAS_SANITIZER) 17 // Use volatile to prevent undefined behavior of dereferencing nullptr. 18 // Intentionally crashing with SIGSEGV. 19 #define LIBC_CRASH_ON_NULLPTR(PTR) \ 20 do { \ 21 if (LIBC_UNLIKELY(PTR == nullptr)) { \ 22 volatile auto *crashing = PTR; \ 23 [[maybe_unused]] volatile auto crash = *crashing; \ 24 __builtin_trap(); \ 25 } \ 26 } while (0) 27 #else 28 #define LIBC_CRASH_ON_NULLPTR(ptr) \ 29 do { \ 30 } while (0) 31 #endif 32 33 #endif // LLVM_LIBC_SRC___SUPPORT_MACROS_NULL_CHECK_H 34