freebsd-src/lib/libc/string/memccpy.c
Robert Clausecker e0d4f419ac lib/libc/string: document restrict qualification of memccpy() arguments
POSIX.1-2004 and the upcoming C23 agree that memccpy()'s arguments
are restrict qualified and must not overlap.  In 2002, restrict
qualifiers were added to <string.h>'s declaration of the function.
Make things official and document that the arguments must not
overlap.

See also:	61b60edfd3
Approved by:	kib
MFC after:	1 month
MFC to:		stable/14
2023-12-25 14:59:50 +01:00

49 lines
1.9 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <string.h>
void *
memccpy(void * restrict t, const void * restrict f, int c, size_t n)
{
if (n) {
unsigned char *tp = t;
const unsigned char *fp = f;
unsigned char uc = c;
do {
if ((*tp++ = *fp++) == uc)
return (tp);
} while (--n != 0);
}
return (0);
}