1*db8a88feSMichael Jones //===-- Implementation of memccpy ----------------------------------------===//
2*db8a88feSMichael Jones //
3*db8a88feSMichael Jones // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*db8a88feSMichael Jones // See https://llvm.org/LICENSE.txt for license information.
5*db8a88feSMichael Jones // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*db8a88feSMichael Jones //
7*db8a88feSMichael Jones //===----------------------------------------------------------------------===//
8*db8a88feSMichael Jones 
9*db8a88feSMichael Jones #include "src/string/memccpy.h"
10*db8a88feSMichael Jones 
11*db8a88feSMichael Jones #include "src/__support/common.h"
12*db8a88feSMichael Jones #include <stddef.h> // For size_t.
13*db8a88feSMichael Jones 
14*db8a88feSMichael Jones namespace __llvm_libc {
15*db8a88feSMichael Jones 
16*db8a88feSMichael Jones LLVM_LIBC_FUNCTION(void *, memccpy,
17*db8a88feSMichael Jones                    (void *__restrict dest, const void *__restrict src, int c,
18*db8a88feSMichael Jones                     size_t count)) {
19*db8a88feSMichael Jones   unsigned char end = static_cast<unsigned char>(c);
20*db8a88feSMichael Jones   const unsigned char *ucSrc = static_cast<const unsigned char *>(src);
21*db8a88feSMichael Jones   unsigned char *ucDest = static_cast<unsigned char *>(dest);
22*db8a88feSMichael Jones   size_t i = 0;
23*db8a88feSMichael Jones   // Copy up until end is found.
24*db8a88feSMichael Jones   for (; i < count && ucSrc[i] != end; ++i)
25*db8a88feSMichael Jones     ucDest[i] = ucSrc[i];
26*db8a88feSMichael Jones   // if i < count, then end must have been found, so copy end into dest and
27*db8a88feSMichael Jones   // return the byte after.
28*db8a88feSMichael Jones   if (i < count) {
29*db8a88feSMichael Jones     ucDest[i] = ucSrc[i];
30*db8a88feSMichael Jones     return ucDest + i + 1;
31*db8a88feSMichael Jones   }
32*db8a88feSMichael Jones   return nullptr;
33*db8a88feSMichael Jones }
34*db8a88feSMichael Jones 
35*db8a88feSMichael Jones } // namespace __llvm_libc
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