newlib-cygwin/newlib/libc/time/lcltime_r.c

127 lines
2.9 KiB
C

/*
* localtime_r.c
* Original Author: Adapted from tzcode maintained by Arthur David Olson.
* Modifications:
* - Changed to mktm_r and added __tzcalc_limits - 04/10/02, Jeff Johnston
* - Fixed bug in mday computations - 08/12/04, Alex Mogilnikov <alx@intellectronika.ru>
* - Fixed bug in __tzcalc_limits - 08/12/04, Alex Mogilnikov <alx@intellectronika.ru>
* - Implement localtime_r() with gmtime_r() and the conditional code moved
* from _mktm_r() - 05/09/14, Freddie Chopin <freddie_chopin@op.pl>
*
* Converts the calendar time pointed to by tim_p into a broken-down time
* expressed as local time. Returns a pointer to a structure containing the
* broken-down time.
*/
#include "local.h"
struct tm *
localtime_r (const time_t *__restrict tim_p,
struct tm *__restrict res)
{
long offset;
int hours, mins, secs;
int year;
__tzinfo_type *const tz = __gettzinfo ();
const int *ip;
res = gmtime_r (tim_p, res);
year = res->tm_year + YEAR_BASE;
ip = __month_lengths[isleap(year)];
TZ_LOCK;
_tzset_unlocked ();
if (_daylight)
{
if (year == tz->__tzyear || __tzcalc_limits (year))
res->tm_isdst = (tz->__tznorth
? (*tim_p >= tz->__tzrule[0].change
&& *tim_p < tz->__tzrule[1].change)
: (*tim_p >= tz->__tzrule[0].change
|| *tim_p < tz->__tzrule[1].change));
else
res->tm_isdst = -1;
}
else
res->tm_isdst = 0;
offset = (res->tm_isdst == 1
? tz->__tzrule[1].offset
: tz->__tzrule[0].offset);
hours = (int) (offset / SECSPERHOUR);
offset = offset % SECSPERHOUR;
mins = (int) (offset / SECSPERMIN);
secs = (int) (offset % SECSPERMIN);
res->tm_sec -= secs;
res->tm_min -= mins;
res->tm_hour -= hours;
if (res->tm_sec >= SECSPERMIN)
{
res->tm_min += 1;
res->tm_sec -= SECSPERMIN;
}
else if (res->tm_sec < 0)
{
res->tm_min -= 1;
res->tm_sec += SECSPERMIN;
}
if (res->tm_min >= MINSPERHOUR)
{
res->tm_hour += 1;
res->tm_min -= MINSPERHOUR;
}
else if (res->tm_min < 0)
{
res->tm_hour -= 1;
res->tm_min += MINSPERHOUR;
}
if (res->tm_hour >= HOURSPERDAY)
{
++res->tm_yday;
++res->tm_wday;
if (res->tm_wday > 6)
res->tm_wday = 0;
++res->tm_mday;
res->tm_hour -= HOURSPERDAY;
if (res->tm_mday > ip[res->tm_mon])
{
res->tm_mday -= ip[res->tm_mon];
res->tm_mon += 1;
if (res->tm_mon == 12)
{
res->tm_mon = 0;
res->tm_year += 1;
res->tm_yday = 0;
}
}
}
else if (res->tm_hour < 0)
{
res->tm_yday -= 1;
res->tm_wday -= 1;
if (res->tm_wday < 0)
res->tm_wday = 6;
res->tm_mday -= 1;
res->tm_hour += 24;
if (res->tm_mday == 0)
{
res->tm_mon -= 1;
if (res->tm_mon < 0)
{
res->tm_mon = 11;
res->tm_year -= 1;
res->tm_yday = 364 + isleap(res->tm_year + YEAR_BASE);
}
res->tm_mday = ip[res->tm_mon];
}
}
TZ_UNLOCK;
return (res);
}