xref: /aosp_15_r20/external/llvm-libc/src/string/strncat.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===-- Implementation of strncat -----------------------------------------===//
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/strncat.h"
10 #include "src/__support/macros/config.h"
11 #include "src/string/string_utils.h"
12 #include "src/string/strncpy.h"
13 
14 #include "src/__support/common.h"
15 
16 namespace LIBC_NAMESPACE_DECL {
17 
18 LLVM_LIBC_FUNCTION(char *, strncat,
19                    (char *__restrict dest, const char *__restrict src,
20                     size_t count)) {
21   size_t src_length = internal::string_length(src);
22   size_t copy_amount = src_length > count ? count : src_length;
23   size_t dest_length = internal::string_length(dest);
24   LIBC_NAMESPACE::strncpy(dest + dest_length, src, copy_amount);
25   dest[dest_length + copy_amount] = '\0';
26   return dest;
27 }
28 
29 } // namespace LIBC_NAMESPACE_DECL
30