33 lines · cpp
1//===-- Implementation of memrchr -----------------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8 9#include "src/string/memrchr.h"10#include "src/__support/common.h"11#include "src/__support/macros/config.h"12#include "src/__support/macros/null_check.h"13#include <stddef.h>14 15namespace LIBC_NAMESPACE_DECL {16 17LLVM_LIBC_FUNCTION(void *, memrchr, (const void *src, int c, size_t n)) {18 19 if (n)20 LIBC_CRASH_ON_NULLPTR(src);21 22 const unsigned char *str = reinterpret_cast<const unsigned char *>(src);23 const unsigned char ch = static_cast<unsigned char>(c);24 for (; n != 0; --n) {25 const unsigned char *s = str + n - 1;26 if (*s == ch)27 return const_cast<unsigned char *>(s);28 }29 return nullptr;30}31 32} // namespace LIBC_NAMESPACE_DECL33