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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "src/string/memrchr.h" 10 #include "src/__support/common.h" 11 #include "src/__support/macros/config.h" 12 #include <stddef.h> 13 14 namespace LIBC_NAMESPACE_DECL { 15 16 LLVM_LIBC_FUNCTION(void *, memrchr, (const void *src, int c, size_t n)) { 17 const unsigned char *str = reinterpret_cast<const unsigned char *>(src); 18 const unsigned char ch = static_cast<unsigned char>(c); 19 for (; n != 0; --n) { 20 const unsigned char *s = str + n - 1; 21 if (*s == ch) 22 return const_cast<unsigned char *>(s); 23 } 24 return nullptr; 25 } 26 27 } // namespace LIBC_NAMESPACE_DECL 28