1 //===-- Implementation of memccpy ----------------------------------------===// 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/memccpy.h" 10 11 #include "src/__support/common.h" 12 #include "src/__support/macros/config.h" 13 #include <stddef.h> // For size_t. 14 15 namespace LIBC_NAMESPACE_DECL { 16 17 LLVM_LIBC_FUNCTION(void *, memccpy, 18 (void *__restrict dest, const void *__restrict src, int c, 19 size_t count)) { 20 unsigned char end = static_cast<unsigned char>(c); 21 const unsigned char *uc_src = static_cast<const unsigned char *>(src); 22 unsigned char *uc_dest = static_cast<unsigned char *>(dest); 23 size_t i = 0; 24 // Copy up until end is found. 25 for (; i < count && uc_src[i] != end; ++i) 26 uc_dest[i] = uc_src[i]; 27 // if i < count, then end must have been found, so copy end into dest and 28 // return the byte after. 29 if (i < count) { 30 uc_dest[i] = uc_src[i]; 31 return uc_dest + i + 1; 32 } 33 return nullptr; 34 } 35 36 } // namespace LIBC_NAMESPACE_DECL 37