114 lines
2.8 KiB
C
114 lines
2.8 KiB
C
/* Checking strncat.
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Copyright (C) 1991-2020 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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version.
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In addition to the permissions in the GNU General Public License, the
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Free Software Foundation gives you unlimited permission to link the
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compiled version of this file into combinations with other programs,
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and to distribute those combinations without any restriction coming
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from the use of this file. (The General Public License restrictions
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do apply in other respects; for example, they cover modification of
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the file, and distribution when not linked into a combine
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executable.)
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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Under Section 7 of GPL version 3, you are granted additional
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permissions described in the GCC Runtime Library Exception, version
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3.1, as published by the Free Software Foundation.
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You should have received a copy of the GNU General Public License and
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a copy of the GCC Runtime Library Exception along with this program;
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see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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<http://www.gnu.org/licenses/>. */
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#include "config.h"
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#include <ssp/ssp.h>
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#ifdef HAVE_STRING_H
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# include <string.h>
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#endif
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extern void __chk_fail (void) __attribute__((__noreturn__));
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char *
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__strncat_chk (char *__restrict__ dest, const char *__restrict__ src,
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size_t n, size_t slen)
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{
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char c;
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char *s = dest;
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do
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{
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if (slen-- == 0)
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__chk_fail ();
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c = *dest++;
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}
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while (c != '\0');
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++slen;
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dest -= 2;
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if (n >= 4)
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{
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size_t n4 = n >> 2;
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do
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{
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if (slen-- == 0)
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__chk_fail ();
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c = *src++;
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*++dest = c;
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if (c == '\0')
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return s;
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if (slen-- == 0)
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__chk_fail ();
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c = *src++;
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*++dest = c;
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if (c == '\0')
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return s;
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if (slen-- == 0)
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__chk_fail ();
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c = *src++;
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*++dest = c;
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if (c == '\0')
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return s;
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if (slen-- == 0)
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__chk_fail ();
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c = *src++;
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*++dest = c;
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if (c == '\0')
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return s;
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} while (--n4 > 0);
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n &= 3;
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}
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while (n > 0)
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{
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if (slen-- == 0)
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__chk_fail ();
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c = *src++;
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*++dest = c;
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if (c == '\0')
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return s;
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n--;
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}
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if (c != '\0')
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{
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if (slen-- == 0)
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__chk_fail ();
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*++dest = '\0';
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}
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return s;
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}
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