kolibrios-gitea/programs/develop/open watcom/trunk/clib/time/mktime.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: Platform independent mktime() implementation.
*
****************************************************************************/
#include "variety.h"
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <limits.h>
#include "rtdata.h"
#include "timedata.h"
_WCRTLINK time_t mktime( struct tm *t )
{
long days;
long seconds;
long day_seconds;
seconds = __local_mktime( t, &days, &day_seconds );
__brktime( (unsigned long) days, (time_t) day_seconds, 0L, t );
tzset();
seconds += _RWD_timezone; /* add in seconds from GMT */
#ifdef __LINUX__
if( t->tm_isdst < 0 )
__check_tzfile( seconds, t );
#endif
/* if we are in d.s.t. then subtract __dst_adjust from seconds */
if( __isindst( t ) ) /* - determine if we are in d.s.t. */
seconds -= _RWD_dst_adjust;
#ifdef __UNIX__ /* time_t is signed */
if( seconds < 0 )
return( ( time_t ) -1 );
#else /* time_t is unsigned, special day check needed for 31 dec 1969 */
/* check for overflow; days == 75277 && seconds == 23296 returns 0, but
adjusted for dst may still be fine */
if( days >= 75279 ||
( seconds >= 0 && days >= 75276 ) ||
( seconds < 0 && days <= DAYS_FROM_1900_TO_1970 ) )
return( (time_t) -1 );
/* 0 is year = 206, mon = 1, mday = 7, hour = 6, min = 28, sec = 16 */
#endif
return( ( time_t ) seconds );
}