libc/src/string/strncat.cpp

   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