1 /* Copyright (C) 1995-2022 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, see
16    <https://www.gnu.org/licenses/>.  */
17 
18 #include <wchar.h>
19 
20 
21 /* Append SRC on the end of DEST.  Check for overflows.  */
22 wchar_t *
__wcscat_chk(wchar_t * dest,const wchar_t * src,size_t destlen)23 __wcscat_chk (wchar_t *dest, const wchar_t *src, size_t destlen)
24 {
25   wchar_t *s1 = dest;
26   const wchar_t *s2 = src;
27   wchar_t c;
28 
29   /* Find the end of the string.  */
30   do
31     {
32       if (__glibc_unlikely (destlen-- == 0))
33 	__chk_fail ();
34       c = *s1++;
35     }
36   while (c != L'\0');
37 
38   /* Make S1 point before the next character, so we can increment
39      it while memory is read (wins on pipelined cpus).	*/
40   s1 -= 2;
41   ++destlen;
42 
43   do
44     {
45       if (__glibc_unlikely (destlen-- == 0))
46 	__chk_fail ();
47       c = *s2++;
48       *++s1 = c;
49     }
50   while (c != L'\0');
51 
52   return dest;
53 }
54