96 lines
2.0 KiB
C
96 lines
2.0 KiB
C
/* Copyright (C) 1991-2022 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <string.h>
|
|
|
|
#include <memcopy.h>
|
|
|
|
|
|
char *
|
|
__strncat_chk (char *s1, const char *s2, size_t n, size_t s1len)
|
|
{
|
|
char c;
|
|
char *s = s1;
|
|
|
|
/* Find the end of S1. */
|
|
do
|
|
{
|
|
if (__glibc_unlikely (s1len-- == 0))
|
|
__chk_fail ();
|
|
c = *s1++;
|
|
}
|
|
while (c != '\0');
|
|
|
|
/* Make S1 point before next character, so we can increment
|
|
it while memory is read (wins on pipelined cpus). */
|
|
++s1len;
|
|
s1 -= 2;
|
|
|
|
if (n >= 4)
|
|
{
|
|
size_t n4 = n >> 2;
|
|
do
|
|
{
|
|
if (__glibc_unlikely (s1len-- == 0))
|
|
__chk_fail ();
|
|
c = *s2++;
|
|
*++s1 = c;
|
|
if (c == '\0')
|
|
return s;
|
|
if (__glibc_unlikely (s1len-- == 0))
|
|
__chk_fail ();
|
|
c = *s2++;
|
|
*++s1 = c;
|
|
if (c == '\0')
|
|
return s;
|
|
if (__glibc_unlikely (s1len-- == 0))
|
|
__chk_fail ();
|
|
c = *s2++;
|
|
*++s1 = c;
|
|
if (c == '\0')
|
|
return s;
|
|
if (__glibc_unlikely (s1len-- == 0))
|
|
__chk_fail ();
|
|
c = *s2++;
|
|
*++s1 = c;
|
|
if (c == '\0')
|
|
return s;
|
|
} while (--n4 > 0);
|
|
n &= 3;
|
|
}
|
|
|
|
while (n > 0)
|
|
{
|
|
if (__glibc_unlikely (s1len-- == 0))
|
|
__chk_fail ();
|
|
c = *s2++;
|
|
*++s1 = c;
|
|
if (c == '\0')
|
|
return s;
|
|
n--;
|
|
}
|
|
|
|
if (c != '\0')
|
|
{
|
|
if (__glibc_unlikely (s1len-- == 0))
|
|
__chk_fail ();
|
|
*++s1 = '\0';
|
|
}
|
|
|
|
return s;
|
|
}
|