glibc/time/offtime.c
Albert ARIBAUD (3ADEV) 72b8692d7e Y2038: make __tz_convert compatible with 64-bit-time
Now that __time64_t exists, we can switch internal function
__tz_convert from 32-bit to 64-bit time. This involves switching
some other internal functions as well, namely __tz_compute and
__offtime.

Tested with 'make check' on x86_64-linux-gnu and i686-linux.gnu.

	* include/time.h
	(__tz_compute): Replace time_t with __time64_t.
	(__tz_convert): Replace time_t* with __time64_t.
	(__offtime): Replace time_t* with __time64_t.
	* time/gmtime.c
	(__gmtime_r): Adjust call to __tz_convert.
	(gmtime): Likewise.
	* time/localtime.c
	(__localtime_r): Likewise.
	(localtime): Likewise.
	* time/offtime.c: Replace time_t with __time64_t.
	* time/tzset.c: Likewise.
2018-12-05 21:01:22 +01:00

87 lines
2.5 KiB
C

/* Copyright (C) 1991-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <time.h>
#define SECS_PER_HOUR (60 * 60)
#define SECS_PER_DAY (SECS_PER_HOUR * 24)
/* Compute the `struct tm' representation of T,
offset OFFSET seconds east of UTC,
and store year, yday, mon, mday, wday, hour, min, sec into *TP.
Return nonzero if successful. */
int
__offtime (__time64_t t, long int offset, struct tm *tp)
{
__time64_t days, rem, y;
const unsigned short int *ip;
days = t / SECS_PER_DAY;
rem = t % SECS_PER_DAY;
rem += offset;
while (rem < 0)
{
rem += SECS_PER_DAY;
--days;
}
while (rem >= SECS_PER_DAY)
{
rem -= SECS_PER_DAY;
++days;
}
tp->tm_hour = rem / SECS_PER_HOUR;
rem %= SECS_PER_HOUR;
tp->tm_min = rem / 60;
tp->tm_sec = rem % 60;
/* January 1, 1970 was a Thursday. */
tp->tm_wday = (4 + days) % 7;
if (tp->tm_wday < 0)
tp->tm_wday += 7;
y = 1970;
#define DIV(a, b) ((a) / (b) - ((a) % (b) < 0))
#define LEAPS_THRU_END_OF(y) (DIV (y, 4) - DIV (y, 100) + DIV (y, 400))
while (days < 0 || days >= (__isleap (y) ? 366 : 365))
{
/* Guess a corrected year, assuming 365 days per year. */
__time64_t yg = y + days / 365 - (days % 365 < 0);
/* Adjust DAYS and Y to match the guessed year. */
days -= ((yg - y) * 365
+ LEAPS_THRU_END_OF (yg - 1)
- LEAPS_THRU_END_OF (y - 1));
y = yg;
}
tp->tm_year = y - 1900;
if (tp->tm_year != y - 1900)
{
/* The year cannot be represented due to overflow. */
__set_errno (EOVERFLOW);
return 0;
}
tp->tm_yday = days;
ip = __mon_yday[__isleap(y)];
for (y = 11; days < (long int) ip[y]; --y)
continue;
days -= ip[y];
tp->tm_mon = y;
tp->tm_mday = days + 1;
return 1;
}