kolibrios/programs/develop/open watcom/trunk/clib/string/stncat_s.c

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/****************************************************************************
*
* Open Watcom Project
*
* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
* ========================================================================
*
* This file contains Original Code and/or Modifications of Original
* Code as defined in and that are subject to the Sybase Open Watcom
* Public License version 1.0 (the 'License'). You may not use this file
* except in compliance with the License. BY USING THIS FILE YOU AGREE TO
* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
* provided with the Original Code and Modifications, and is also
* available at www.sybase.com/developer/opensource.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
* NON-INFRINGEMENT. Please see the License for the specific language
* governing rights and limitations under the License.
*
* ========================================================================
*
* Description: Implementation of strncat_s() - bounds-checking strncat().
*
****************************************************************************/
#include "variety.h"
#include "saferlib.h"
#include "widechar.h"
#include <string.h>
#include <wchar.h>
_WCRTLINK errno_t __F_NAME(strncat_s,wcsncat_s)( CHAR_TYPE * __restrict s1,
rsize_t s1max, const CHAR_TYPE * __restrict s2,
rsize_t n )
/*************************************************************************/
{
errno_t rc = -1;
const char *msg;
// strnlen_s is safe to use as it has no rt constraints
rsize_t m = s1max - __F_NAME(strnlen_s,wcsnlen_s)( s1, s1max );
// Verify runtime-constraints
// s1 not NULL
// s2 not NULL
// s1max <= RSIZE_MAX
// n <= RSIZE_MAX
// s1max != 0
// m = s1max - strnlen_s( s1, s1max ) != 0
// if n >= m then m > strnlen_s( s2, m )
// s1 and s2 no overlap
if( __check_constraint_nullptr_msg( msg, s1 ) &&
__check_constraint_nullptr_msg( msg, s2 ) &&
__check_constraint_maxsize_msg( msg, s1max ) &&
__check_constraint_maxsize_msg( msg, m ) &&
__check_constraint_zero_msg( msg, s1max ) &&
__check_constraint_zero_msg( msg, m ) &&
((n < m) || __check_constraint_a_gt_b_msg( msg, __F_NAME(strnlen_s,wcsnlen_s)( s2, m ), m - 1 )) &&
__check_constraint_overlap_msg( msg, s1, s1max, s2, __F_NAME(strnlen_s,wcsnlen_s)( s2, s1max ))) {
while( *s1 != NULLCHAR ) ++s1; //find end of field
while( n != 0 ) {
*s1 = *s2;
if( *s2 == NULLCHAR ) break;
++s1;
++s2;
--n;
}
*s1 = NULLCHAR;
rc = 0;
} else {
// Runtime-constraints found, store zero in receiving field
if( (s1 != NULL) && (s1max > 0) && __lte_rsizmax( s1max ) ) {
s1[0] = NULLCHAR;
}
// Now call the handler
__rtct_fail( __func__, msg, NULL );
}
return( rc );
}