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mirror of git://sourceware.org/git/newlib-cygwin.git synced 2025-01-15 19:09:58 +08:00
Jeff Johnston 10d0021609 2002-04-17 Jeff Johnston <jjohnstn@redhat.com>
*  libc/include/time.h (tzset, _tzset_r): Added prototypes.
        (strptime): Moved prototype to be within !__STRICT_ANSI__.
        (_tzname, _daylight, _timezone): No long __CYGWIN__ only.
        (tzname): Defined for all platforms.
        (daylight, timezone): Defined only for CYGWIN.
        *  libc/sys/linux/machine/i386/crt0.c: Add call to tzset() after
        environment set up.
        * libc/stdlib/setenv_r.c (_setenv_r): Call tzset() if the TZ
        environment variable is set.
        *  libc/time/Makefile.am: Add support for tzset.c, tzlock.c, and
        tzset_r.c.
        *  libc/time/Makefile.in: Regenerated.
        *  libc/time/gmtime.c (gmtime): Changed to call gmtime_r.
        *  libc/time/gmtime_r.c (gmtime_r): Changed to call _mktm_r.
        *  libc/time/lcltime_r.c (lcltime_r): Ditto.
        *  libc/time/local.h: New local header file.
        *  libc/time/mktime.c (mktime): Add timezone support.
        *  libc/time/mktm_r.c: New file which is the common engine
        for gmtime_r and lcltime_r.  This code has timezone support.
        *  libc/time/strftime.c (strftime): Add %Z timezone support.
        *  libc/time/tzlock.c: New file containing timezone lock stubs.
        *  libc/time/tzset.c: New file containing tzset() routine.
        *  libc/time/tzset_r.c: New file containing _tzset_r and
        internal routine for calculating timezone changes for specified year.
2002-04-17 21:23:31 +00:00

251 lines
6.2 KiB
C

/*
* mktime.c
* Original Author: G. Haley
*
* Converts the broken-down time, expressed as local time, in the structure
* pointed to by tim_p into a calendar time value. The original values of the
* tm_wday and tm_yday fields of the structure are ignored, and the original
* values of the other fields have no restrictions. On successful completion
* the fields of the structure are set to represent the specified calendar
* time. Returns the specified calendar time. If the calendar time can not be
* represented, returns the value (time_t) -1.
*/
/*
FUNCTION
<<mktime>>---convert time to arithmetic representation
INDEX
mktime
ANSI_SYNOPSIS
#include <time.h>
time_t mktime(struct tm *<[timp]>);
TRAD_SYNOPSIS
#include <time.h>
time_t mktime(<[timp]>)
struct tm *<[timp]>;
DESCRIPTION
<<mktime>> assumes the time at <[timp]> is a local time, and converts
its representation from the traditional representation defined by
<<struct tm>> into a representation suitable for arithmetic.
<<localtime>> is the inverse of <<mktime>>.
RETURNS
If the contents of the structure at <[timp]> do not form a valid
calendar time representation, the result is <<-1>>. Otherwise, the
result is the time, converted to a <<time_t>> value.
PORTABILITY
ANSI C requires <<mktime>>.
<<mktime>> requires no supporting OS subroutines.
*/
#include <stdlib.h>
#include <time.h>
#include "local.h"
#define _SEC_IN_MINUTE 60L
#define _SEC_IN_HOUR 3600L
#define _SEC_IN_DAY 86400L
static _CONST int DAYS_IN_MONTH[12] =
{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
#define _DAYS_IN_MONTH(x) ((x == 1) ? days_in_feb : DAYS_IN_MONTH[x])
static _CONST int _DAYS_BEFORE_MONTH[12] =
{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334};
#define _ISLEAP(y) (((y) % 4) == 0 && (((y) % 100) != 0 || (((y)+1900) % 400) == 0))
#define _DAYS_IN_YEAR(year) (_ISLEAP(year) ? 366 : 365)
static void
validate_structure (tim_p)
struct tm *tim_p;
{
div_t res;
int days_in_feb = 28;
/* calculate time & date to account for out of range values */
if (tim_p->tm_sec < 0 || tim_p->tm_sec > 59)
{
res = div (tim_p->tm_sec, 60);
tim_p->tm_min += res.quot;
if ((tim_p->tm_sec = res.rem) < 0)
{
tim_p->tm_sec += 60;
--tim_p->tm_min;
}
}
if (tim_p->tm_min < 0 || tim_p->tm_min > 59)
{
res = div (tim_p->tm_min, 60);
tim_p->tm_hour += res.quot;
if ((tim_p->tm_min = res.rem) < 0)
{
tim_p->tm_min += 60;
--tim_p->tm_hour;
}
}
if (tim_p->tm_hour < 0 || tim_p->tm_hour > 23)
{
res = div (tim_p->tm_hour, 24);
tim_p->tm_mday += res.quot;
if ((tim_p->tm_hour = res.rem) < 0)
{
tim_p->tm_hour += 24;
--tim_p->tm_mday;
}
}
if (tim_p->tm_mon > 11)
{
res = div (tim_p->tm_mon, 12);
tim_p->tm_year += res.quot;
if ((tim_p->tm_mon = res.rem) < 0)
{
tim_p->tm_mon += 12;
--tim_p->tm_year;
}
}
if (_DAYS_IN_YEAR (tim_p->tm_year) == 366)
days_in_feb = 29;
if (tim_p->tm_mday <= 0)
{
while (tim_p->tm_mday <= 0)
{
if (--tim_p->tm_mon == -1)
{
tim_p->tm_year--;
tim_p->tm_mon = 11;
days_in_feb =
((_DAYS_IN_YEAR (tim_p->tm_year) == 366) ?
29 : 28);
}
tim_p->tm_mday += _DAYS_IN_MONTH (tim_p->tm_mon);
}
}
else
{
while (tim_p->tm_mday > _DAYS_IN_MONTH (tim_p->tm_mon))
{
tim_p->tm_mday -= _DAYS_IN_MONTH (tim_p->tm_mon);
if (++tim_p->tm_mon == 12)
{
tim_p->tm_year++;
tim_p->tm_mon = 0;
days_in_feb =
((_DAYS_IN_YEAR (tim_p->tm_year) == 366) ?
29 : 28);
}
}
}
}
time_t
mktime (tim_p)
struct tm *tim_p;
{
time_t tim = 0;
long days = 0;
int year, isdst;
/* validate structure */
validate_structure (tim_p);
/* compute hours, minutes, seconds */
tim += tim_p->tm_sec + (tim_p->tm_min * _SEC_IN_MINUTE) +
(tim_p->tm_hour * _SEC_IN_HOUR);
/* compute days in year */
days += tim_p->tm_mday - 1;
days += _DAYS_BEFORE_MONTH[tim_p->tm_mon];
if (tim_p->tm_mon > 1 && _DAYS_IN_YEAR (tim_p->tm_year) == 366)
days++;
/* compute day of the year */
tim_p->tm_yday = days;
if (tim_p->tm_year > 10000
|| tim_p->tm_year < -10000)
{
return (time_t) -1;
}
/* compute days in other years */
if (tim_p->tm_year > 70)
{
for (year = 70; year < tim_p->tm_year; year++)
days += _DAYS_IN_YEAR (year);
}
else if (tim_p->tm_year < 70)
{
for (year = 69; year > tim_p->tm_year; year--)
days -= _DAYS_IN_YEAR (year);
days -= _DAYS_IN_YEAR (year);
}
/* compute day of the week */
if ((tim_p->tm_wday = (days + 4) % 7) < 0)
tim_p->tm_wday += 7;
/* compute total seconds */
tim += (days * _SEC_IN_DAY);
isdst = tim_p->tm_isdst;
if (_daylight)
{
int y = tim_p->tm_year + YEAR_BASE;
if (y == __tzyear || __tzcalc_limits (y))
{
/* calculate start of dst in dst local time and
start of std in both std local time and dst local time */
time_t startdst_dst = __tzrule[0].change - __tzrule[1].offset;
time_t startstd_dst = __tzrule[1].change - __tzrule[1].offset;
time_t startstd_std = __tzrule[1].change - __tzrule[0].offset;
/* if the time is in the overlap between dst and std local times */
if (tim >= startstd_std && tim < startstd_dst)
; /* we let user decide or leave as -1 */
else
{
isdst = (__tznorth
? (tim >= startdst_dst && tim < startstd_std)
: (tim >= startdst_dst || tim < startstd_std));
/* if user committed and was wrong, perform correction */
if ((isdst ^ tim_p->tm_isdst) == 1)
{
/* we either subtract or add the difference between
time zone offsets, depending on which way the user got it wrong */
int diff = __tzrule[0].offset - __tzrule[1].offset;
if (!isdst)
diff = -diff;
tim_p->tm_sec += diff;
validate_structure (tim_p);
tim += diff; /* we also need to correct our current time calculation */
}
}
}
}
/* add appropriate offset to put time in gmt format */
if (isdst == 1)
tim += __tzrule[1].offset;
else /* otherwise assume std time */
tim += __tzrule[0].offset;
/* reset isdst flag to what we have calculated */
tim_p->tm_isdst = isdst;
return tim;
}