tmfix.c revision 34f9b3eef6fdadbda0a846aa4d68691ac40eace5
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2009 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* Glenn Fowler
* AT&T Research
*
* time conversion support
*/
#include <ast.h>
#include <tmx.h>
#define DAYS(p) (tm_data.days[(p)->tm_mon]+((p)->tm_mon==1&&LEAP(p)))
#define LEAP(p) (tmisleapyear((p)->tm_year))
/*
* correct out of bounds fields in tm
*
* tm_isdst is not changed -- call tmxtm() to get that
*
* tm is the return value
*/
Tm_t*
tmfix(register Tm_t* tm)
{
register int n;
register int w;
Tm_t* p;
time_t t;
/*
* check for special case that adjusts tm_wday at the end
* this happens during
* nl_langinfo() => strftime() => tmfmt()
*/
if (w = !tm->tm_sec && !tm->tm_min && !tm->tm_mday && !tm->tm_year && !tm->tm_yday && !tm->tm_isdst)
{
tm->tm_year = 99;
tm->tm_mday = 2;
}
/*
* adjust from shortest to longest units
*/
if ((n = tm->tm_nsec) < 0)
{
tm->tm_sec -= (TMX_RESOLUTION - n) / TMX_RESOLUTION;
tm->tm_nsec = TMX_RESOLUTION - (-n) % TMX_RESOLUTION;
}
else if (n >= TMX_RESOLUTION)
{
tm->tm_sec += n / TMX_RESOLUTION;
tm->tm_nsec %= TMX_RESOLUTION;
}
if ((n = tm->tm_sec) < 0)
{
tm->tm_min -= (60 - n) / 60;
tm->tm_sec = 60 - (-n) % 60;
}
else if (n > (59 + TM_MAXLEAP))
{
tm->tm_min += n / 60;
tm->tm_sec %= 60;
}
if ((n = tm->tm_min) < 0)
{
tm->tm_hour -= (60 - n) / 60;
n = tm->tm_min = 60 - (-n) % 60;
}
if (n > 59)
{
tm->tm_hour += n / 60;
tm->tm_min %= 60;
}
if ((n = tm->tm_hour) < 0)
{
tm->tm_mday -= (23 - n) / 24;
tm->tm_hour = 24 - (-n) % 24;
}
else if (n >= 24)
{
tm->tm_mday += n / 24;
tm->tm_hour %= 24;
}
if (tm->tm_mon >= 12)
{
tm->tm_year += tm->tm_mon / 12;
tm->tm_mon %= 12;
}
else if (tm->tm_mon < 0)
{
tm->tm_year--;
if ((tm->tm_mon += 12) < 0)
{
tm->tm_year += tm->tm_mon / 12;
tm->tm_mon = (-tm->tm_mon) % 12;
}
}
while (tm->tm_mday < -365)
{
tm->tm_year--;
tm->tm_mday += 365 + LEAP(tm);
}
while (tm->tm_mday > 365)
{
tm->tm_mday -= 365 + LEAP(tm);
tm->tm_year++;
}
while (tm->tm_mday < 1)
{
if (--tm->tm_mon < 0)
{
tm->tm_mon = 11;
tm->tm_year--;
}
tm->tm_mday += DAYS(tm);
}
while (tm->tm_mday > (n = DAYS(tm)))
{
tm->tm_mday -= n;
if (++tm->tm_mon > 11)
{
tm->tm_mon = 0;
tm->tm_year++;
}
}
if (w)
{
w = tm->tm_wday;
t = tmtime(tm, TM_LOCALZONE);
p = tmmake(&t);
if (w = (w - p->tm_wday))
{
if (w < 0)
w += 7;
tm->tm_wday += w;
if ((tm->tm_mday += w) > DAYS(tm))
tm->tm_mday -= 7;
}
}
tm->tm_yday = tm_data.sum[tm->tm_mon] + (tm->tm_mon > 1 && LEAP(tm)) + tm->tm_mday - 1;
n = tm->tm_year + 1900 - 1;
tm->tm_wday = (n + n / 4 - n / 100 + n / 400 + tm->tm_yday + 1) % 7;
/*
* tm_isdst is adjusted by tmtime()
*/
return tm;
}