2013-11-26 22:56:50 +00:00
|
|
|
|
/* Convert a `struct tm' to a time_t value.
|
2013-11-26 22:57:29 +00:00
|
|
|
|
Copyright (C) 1993-1999, 2002-2007, 2009-2010 Free Software Foundation, Inc.
|
2013-11-26 22:56:50 +00:00
|
|
|
|
This file is part of the GNU C Library.
|
|
|
|
|
Contributed by Paul Eggert <eggert@twinsun.com>.
|
|
|
|
|
|
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
|
|
|
it under the terms of the GNU General Public License as published by
|
|
|
|
|
the Free Software Foundation; either version 3, or (at your option)
|
|
|
|
|
any later version.
|
|
|
|
|
|
|
|
|
|
This program 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 General Public License for more details.
|
|
|
|
|
|
|
|
|
|
You should have received a copy of the GNU General Public License along
|
|
|
|
|
with this program; if not, write to the Free Software Foundation,
|
|
|
|
|
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
|
|
|
|
|
|
|
|
|
|
/* Define this to have a standalone program to test this implementation of
|
|
|
|
|
mktime. */
|
|
|
|
|
/* #define DEBUG 1 */
|
|
|
|
|
|
|
|
|
|
#ifndef _LIBC
|
|
|
|
|
# include <config.h>
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
/* Assume that leap seconds are possible, unless told otherwise.
|
|
|
|
|
If the host has a `zic' command with a `-L leapsecondfilename' option,
|
|
|
|
|
then it supports leap seconds; otherwise it probably doesn't. */
|
|
|
|
|
#ifndef LEAP_SECONDS_POSSIBLE
|
|
|
|
|
# define LEAP_SECONDS_POSSIBLE 1
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
#include <time.h>
|
|
|
|
|
|
|
|
|
|
#include <limits.h>
|
|
|
|
|
|
2013-11-26 22:57:29 +00:00
|
|
|
|
#include <string.h> /* For the real memcpy prototype. */
|
2013-11-26 22:56:50 +00:00
|
|
|
|
|
|
|
|
|
#if DEBUG
|
|
|
|
|
# include <stdio.h>
|
|
|
|
|
# include <stdlib.h>
|
|
|
|
|
/* Make it work even if the system's libc has its own mktime routine. */
|
|
|
|
|
# define mktime my_mktime
|
|
|
|
|
#endif /* DEBUG */
|
|
|
|
|
|
|
|
|
|
/* Shift A right by B bits portably, by dividing A by 2**B and
|
|
|
|
|
truncating towards minus infinity. A and B should be free of side
|
|
|
|
|
effects, and B should be in the range 0 <= B <= INT_BITS - 2, where
|
|
|
|
|
INT_BITS is the number of useful bits in an int. GNU code can
|
|
|
|
|
assume that INT_BITS is at least 32.
|
|
|
|
|
|
|
|
|
|
ISO C99 says that A >> B is implementation-defined if A < 0. Some
|
|
|
|
|
implementations (e.g., UNICOS 9.0 on a Cray Y-MP EL) don't shift
|
|
|
|
|
right in the usual way when A < 0, so SHR falls back on division if
|
|
|
|
|
ordinary A >> B doesn't seem to be the usual signed shift. */
|
2013-11-26 22:57:29 +00:00
|
|
|
|
#define SHR(a, b) \
|
|
|
|
|
(-1 >> 1 == -1 \
|
|
|
|
|
? (a) >> (b) \
|
2013-11-26 22:56:50 +00:00
|
|
|
|
: (a) / (1 << (b)) - ((a) % (1 << (b)) < 0))
|
|
|
|
|
|
|
|
|
|
/* The extra casts in the following macros work around compiler bugs,
|
|
|
|
|
e.g., in Cray C 5.0.3.0. */
|
|
|
|
|
|
|
|
|
|
/* True if the arithmetic type T is an integer type. bool counts as
|
|
|
|
|
an integer. */
|
|
|
|
|
#define TYPE_IS_INTEGER(t) ((t) 1.5 == 1)
|
|
|
|
|
|
|
|
|
|
/* True if negative values of the signed integer type T use two's
|
|
|
|
|
complement, ones' complement, or signed magnitude representation,
|
|
|
|
|
respectively. Much GNU code assumes two's complement, but some
|
|
|
|
|
people like to be portable to all possible C hosts. */
|
|
|
|
|
#define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1)
|
|
|
|
|
#define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0)
|
|
|
|
|
#define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1)
|
|
|
|
|
|
|
|
|
|
/* True if the arithmetic type T is signed. */
|
|
|
|
|
#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
|
|
|
|
|
|
|
|
|
|
/* The maximum and minimum values for the integer type T. These
|
|
|
|
|
macros have undefined behavior if T is signed and has padding bits.
|
|
|
|
|
If this is a problem for you, please let us know how to fix it for
|
|
|
|
|
your host. */
|
|
|
|
|
#define TYPE_MINIMUM(t) \
|
|
|
|
|
((t) (! TYPE_SIGNED (t) \
|
2013-11-26 22:57:29 +00:00
|
|
|
|
? (t) 0 \
|
|
|
|
|
: TYPE_SIGNED_MAGNITUDE (t) \
|
|
|
|
|
? ~ (t) 0 \
|
|
|
|
|
: ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1)))
|
2013-11-26 22:56:50 +00:00
|
|
|
|
#define TYPE_MAXIMUM(t) \
|
|
|
|
|
((t) (! TYPE_SIGNED (t) \
|
2013-11-26 22:57:29 +00:00
|
|
|
|
? (t) -1 \
|
|
|
|
|
: ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))))
|
2013-11-26 22:56:50 +00:00
|
|
|
|
|
|
|
|
|
#ifndef TIME_T_MIN
|
|
|
|
|
# define TIME_T_MIN TYPE_MINIMUM (time_t)
|
|
|
|
|
#endif
|
|
|
|
|
#ifndef TIME_T_MAX
|
|
|
|
|
# define TIME_T_MAX TYPE_MAXIMUM (time_t)
|
|
|
|
|
#endif
|
|
|
|
|
#define TIME_T_MIDPOINT (SHR (TIME_T_MIN + TIME_T_MAX, 1) + 1)
|
|
|
|
|
|
|
|
|
|
/* Verify a requirement at compile-time (unlike assert, which is runtime). */
|
|
|
|
|
#define verify(name, assertion) struct name { char a[(assertion) ? 1 : -1]; }
|
|
|
|
|
|
|
|
|
|
verify (time_t_is_integer, TYPE_IS_INTEGER (time_t));
|
|
|
|
|
verify (twos_complement_arithmetic, TYPE_TWOS_COMPLEMENT (int));
|
|
|
|
|
/* The code also assumes that signed integer overflow silently wraps
|
|
|
|
|
around, but this assumption can't be stated without causing a
|
|
|
|
|
diagnostic on some hosts. */
|
|
|
|
|
|
|
|
|
|
#define EPOCH_YEAR 1970
|
|
|
|
|
#define TM_YEAR_BASE 1900
|
|
|
|
|
verify (base_year_is_a_multiple_of_100, TM_YEAR_BASE % 100 == 0);
|
|
|
|
|
|
|
|
|
|
/* Return 1 if YEAR + TM_YEAR_BASE is a leap year. */
|
|
|
|
|
static inline int
|
|
|
|
|
leapyear (long int year)
|
|
|
|
|
{
|
|
|
|
|
/* Don't add YEAR to TM_YEAR_BASE, as that might overflow.
|
|
|
|
|
Also, work even if YEAR is negative. */
|
|
|
|
|
return
|
|
|
|
|
((year & 3) == 0
|
|
|
|
|
&& (year % 100 != 0
|
2013-11-26 22:57:29 +00:00
|
|
|
|
|| ((year / 100) & 3) == (- (TM_YEAR_BASE / 100) & 3)));
|
2013-11-26 22:56:50 +00:00
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* How many days come before each month (0-12). */
|
|
|
|
|
#ifndef _LIBC
|
|
|
|
|
static
|
|
|
|
|
#endif
|
|
|
|
|
const unsigned short int __mon_yday[2][13] =
|
|
|
|
|
{
|
|
|
|
|
/* Normal years. */
|
|
|
|
|
{ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
|
|
|
|
|
/* Leap years. */
|
|
|
|
|
{ 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
#ifndef _LIBC
|
|
|
|
|
/* Portable standalone applications should supply a <time.h> that
|
|
|
|
|
declares a POSIX-compliant localtime_r, for the benefit of older
|
|
|
|
|
implementations that lack localtime_r or have a nonstandard one.
|
|
|
|
|
See the gnulib time_r module for one way to implement this. */
|
|
|
|
|
# undef __localtime_r
|
|
|
|
|
# define __localtime_r localtime_r
|
|
|
|
|
# define __mktime_internal mktime_internal
|
2013-11-26 22:57:29 +00:00
|
|
|
|
# include "mktime-internal.h"
|
2013-11-26 22:56:50 +00:00
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
/* Return an integer value measuring (YEAR1-YDAY1 HOUR1:MIN1:SEC1) -
|
|
|
|
|
(YEAR0-YDAY0 HOUR0:MIN0:SEC0) in seconds, assuming that the clocks
|
|
|
|
|
were not adjusted between the time stamps.
|
|
|
|
|
|
|
|
|
|
The YEAR values uses the same numbering as TP->tm_year. Values
|
|
|
|
|
need not be in the usual range. However, YEAR1 must not be less
|
|
|
|
|
than 2 * INT_MIN or greater than 2 * INT_MAX.
|
|
|
|
|
|
|
|
|
|
The result may overflow. It is the caller's responsibility to
|
|
|
|
|
detect overflow. */
|
|
|
|
|
|
|
|
|
|
static inline time_t
|
|
|
|
|
ydhms_diff (long int year1, long int yday1, int hour1, int min1, int sec1,
|
2013-11-26 22:57:29 +00:00
|
|
|
|
int year0, int yday0, int hour0, int min0, int sec0)
|
2013-11-26 22:56:50 +00:00
|
|
|
|
{
|
|
|
|
|
verify (C99_integer_division, -1 / 2 == 0);
|
2013-11-26 22:57:29 +00:00
|
|
|
|
#if 0 /* This assertion fails on 32-bit systems with 64-bit time_t, such as
|
|
|
|
|
NetBSD 5 on i386. */
|
2013-11-26 22:56:50 +00:00
|
|
|
|
verify (long_int_year_and_yday_are_wide_enough,
|
2013-11-26 22:57:29 +00:00
|
|
|
|
INT_MAX <= LONG_MAX / 2 || TIME_T_MAX <= UINT_MAX);
|
|
|
|
|
#endif
|
2013-11-26 22:56:50 +00:00
|
|
|
|
|
|
|
|
|
/* Compute intervening leap days correctly even if year is negative.
|
|
|
|
|
Take care to avoid integer overflow here. */
|
|
|
|
|
int a4 = SHR (year1, 2) + SHR (TM_YEAR_BASE, 2) - ! (year1 & 3);
|
|
|
|
|
int b4 = SHR (year0, 2) + SHR (TM_YEAR_BASE, 2) - ! (year0 & 3);
|
|
|
|
|
int a100 = a4 / 25 - (a4 % 25 < 0);
|
|
|
|
|
int b100 = b4 / 25 - (b4 % 25 < 0);
|
|
|
|
|
int a400 = SHR (a100, 2);
|
|
|
|
|
int b400 = SHR (b100, 2);
|
|
|
|
|
int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400);
|
|
|
|
|
|
|
|
|
|
/* Compute the desired time in time_t precision. Overflow might
|
|
|
|
|
occur here. */
|
|
|
|
|
time_t tyear1 = year1;
|
|
|
|
|
time_t years = tyear1 - year0;
|
|
|
|
|
time_t days = 365 * years + yday1 - yday0 + intervening_leap_days;
|
|
|
|
|
time_t hours = 24 * days + hour1 - hour0;
|
|
|
|
|
time_t minutes = 60 * hours + min1 - min0;
|
|
|
|
|
time_t seconds = 60 * minutes + sec1 - sec0;
|
|
|
|
|
return seconds;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/* Return a time_t value corresponding to (YEAR-YDAY HOUR:MIN:SEC),
|
|
|
|
|
assuming that *T corresponds to *TP and that no clock adjustments
|
|
|
|
|
occurred between *TP and the desired time.
|
|
|
|
|
If TP is null, return a value not equal to *T; this avoids false matches.
|
|
|
|
|
If overflow occurs, yield the minimal or maximal value, except do not
|
|
|
|
|
yield a value equal to *T. */
|
|
|
|
|
static time_t
|
|
|
|
|
guess_time_tm (long int year, long int yday, int hour, int min, int sec,
|
2013-11-26 22:57:29 +00:00
|
|
|
|
const time_t *t, const struct tm *tp)
|
2013-11-26 22:56:50 +00:00
|
|
|
|
{
|
|
|
|
|
if (tp)
|
|
|
|
|
{
|
|
|
|
|
time_t d = ydhms_diff (year, yday, hour, min, sec,
|
2013-11-26 22:57:29 +00:00
|
|
|
|
tp->tm_year, tp->tm_yday,
|
|
|
|
|
tp->tm_hour, tp->tm_min, tp->tm_sec);
|
2013-11-26 22:56:50 +00:00
|
|
|
|
time_t t1 = *t + d;
|
|
|
|
|
if ((t1 < *t) == (TYPE_SIGNED (time_t) ? d < 0 : TIME_T_MAX / 2 < d))
|
2013-11-26 22:57:29 +00:00
|
|
|
|
return t1;
|
2013-11-26 22:56:50 +00:00
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Overflow occurred one way or another. Return the nearest result
|
|
|
|
|
that is actually in range, except don't report a zero difference
|
|
|
|
|
if the actual difference is nonzero, as that would cause a false
|
|
|
|
|
match; and don't oscillate between two values, as that would
|
|
|
|
|
confuse the spring-forward gap detector. */
|
|
|
|
|
return (*t < TIME_T_MIDPOINT
|
2013-11-26 22:57:29 +00:00
|
|
|
|
? (*t <= TIME_T_MIN + 1 ? *t + 1 : TIME_T_MIN)
|
|
|
|
|
: (TIME_T_MAX - 1 <= *t ? *t - 1 : TIME_T_MAX));
|
2013-11-26 22:56:50 +00:00
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Use CONVERT to convert *T to a broken down time in *TP.
|
|
|
|
|
If *T is out of range for conversion, adjust it so that
|
|
|
|
|
it is the nearest in-range value and then convert that. */
|
|
|
|
|
static struct tm *
|
|
|
|
|
ranged_convert (struct tm *(*convert) (const time_t *, struct tm *),
|
2013-11-26 22:57:29 +00:00
|
|
|
|
time_t *t, struct tm *tp)
|
2013-11-26 22:56:50 +00:00
|
|
|
|
{
|
|
|
|
|
struct tm *r = convert (t, tp);
|
|
|
|
|
|
|
|
|
|
if (!r && *t)
|
|
|
|
|
{
|
|
|
|
|
time_t bad = *t;
|
|
|
|
|
time_t ok = 0;
|
|
|
|
|
|
|
|
|
|
/* BAD is a known unconvertible time_t, and OK is a known good one.
|
2013-11-26 22:57:29 +00:00
|
|
|
|
Use binary search to narrow the range between BAD and OK until
|
|
|
|
|
they differ by 1. */
|
2013-11-26 22:56:50 +00:00
|
|
|
|
while (bad != ok + (bad < 0 ? -1 : 1))
|
2013-11-26 22:57:29 +00:00
|
|
|
|
{
|
|
|
|
|
time_t mid = *t = (bad < 0
|
|
|
|
|
? bad + ((ok - bad) >> 1)
|
|
|
|
|
: ok + ((bad - ok) >> 1));
|
|
|
|
|
r = convert (t, tp);
|
|
|
|
|
if (r)
|
|
|
|
|
ok = mid;
|
|
|
|
|
else
|
|
|
|
|
bad = mid;
|
|
|
|
|
}
|
2013-11-26 22:56:50 +00:00
|
|
|
|
|
|
|
|
|
if (!r && ok)
|
2013-11-26 22:57:29 +00:00
|
|
|
|
{
|
|
|
|
|
/* The last conversion attempt failed;
|
|
|
|
|
revert to the most recent successful attempt. */
|
|
|
|
|
*t = ok;
|
|
|
|
|
r = convert (t, tp);
|
|
|
|
|
}
|
2013-11-26 22:56:50 +00:00
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return r;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/* Convert *TP to a time_t value, inverting
|
|
|
|
|
the monotonic and mostly-unit-linear conversion function CONVERT.
|
|
|
|
|
Use *OFFSET to keep track of a guess at the offset of the result,
|
|
|
|
|
compared to what the result would be for UTC without leap seconds.
|
|
|
|
|
If *OFFSET's guess is correct, only one CONVERT call is needed.
|
|
|
|
|
This function is external because it is used also by timegm.c. */
|
|
|
|
|
time_t
|
|
|
|
|
__mktime_internal (struct tm *tp,
|
2013-11-26 22:57:29 +00:00
|
|
|
|
struct tm *(*convert) (const time_t *, struct tm *),
|
|
|
|
|
time_t *offset)
|
2013-11-26 22:56:50 +00:00
|
|
|
|
{
|
|
|
|
|
time_t t, gt, t0, t1, t2;
|
|
|
|
|
struct tm tm;
|
|
|
|
|
|
|
|
|
|
/* The maximum number of probes (calls to CONVERT) should be enough
|
|
|
|
|
to handle any combinations of time zone rule changes, solar time,
|
|
|
|
|
leap seconds, and oscillations around a spring-forward gap.
|
|
|
|
|
POSIX.1 prohibits leap seconds, but some hosts have them anyway. */
|
|
|
|
|
int remaining_probes = 6;
|
|
|
|
|
|
|
|
|
|
/* Time requested. Copy it in case CONVERT modifies *TP; this can
|
|
|
|
|
occur if TP is localtime's returned value and CONVERT is localtime. */
|
|
|
|
|
int sec = tp->tm_sec;
|
|
|
|
|
int min = tp->tm_min;
|
|
|
|
|
int hour = tp->tm_hour;
|
|
|
|
|
int mday = tp->tm_mday;
|
|
|
|
|
int mon = tp->tm_mon;
|
|
|
|
|
int year_requested = tp->tm_year;
|
|
|
|
|
/* Normalize the value. */
|
|
|
|
|
int isdst = ((tp->tm_isdst >> (8 * sizeof (tp->tm_isdst) - 1))
|
2013-11-26 22:57:29 +00:00
|
|
|
|
| (tp->tm_isdst != 0));
|
2013-11-26 22:56:50 +00:00
|
|
|
|
|
|
|
|
|
/* 1 if the previous probe was DST. */
|
|
|
|
|
int dst2;
|
|
|
|
|
|
|
|
|
|
/* Ensure that mon is in range, and set year accordingly. */
|
|
|
|
|
int mon_remainder = mon % 12;
|
|
|
|
|
int negative_mon_remainder = mon_remainder < 0;
|
|
|
|
|
int mon_years = mon / 12 - negative_mon_remainder;
|
|
|
|
|
long int lyear_requested = year_requested;
|
|
|
|
|
long int year = lyear_requested + mon_years;
|
|
|
|
|
|
|
|
|
|
/* The other values need not be in range:
|
|
|
|
|
the remaining code handles minor overflows correctly,
|
|
|
|
|
assuming int and time_t arithmetic wraps around.
|
|
|
|
|
Major overflows are caught at the end. */
|
|
|
|
|
|
|
|
|
|
/* Calculate day of year from year, month, and day of month.
|
|
|
|
|
The result need not be in range. */
|
|
|
|
|
int mon_yday = ((__mon_yday[leapyear (year)]
|
2013-11-26 22:57:29 +00:00
|
|
|
|
[mon_remainder + 12 * negative_mon_remainder])
|
|
|
|
|
- 1);
|
2013-11-26 22:56:50 +00:00
|
|
|
|
long int lmday = mday;
|
|
|
|
|
long int yday = mon_yday + lmday;
|
|
|
|
|
|
|
|
|
|
time_t guessed_offset = *offset;
|
|
|
|
|
|
|
|
|
|
int sec_requested = sec;
|
|
|
|
|
|
|
|
|
|
if (LEAP_SECONDS_POSSIBLE)
|
|
|
|
|
{
|
|
|
|
|
/* Handle out-of-range seconds specially,
|
2013-11-26 22:57:29 +00:00
|
|
|
|
since ydhms_tm_diff assumes every minute has 60 seconds. */
|
2013-11-26 22:56:50 +00:00
|
|
|
|
if (sec < 0)
|
2013-11-26 22:57:29 +00:00
|
|
|
|
sec = 0;
|
2013-11-26 22:56:50 +00:00
|
|
|
|
if (59 < sec)
|
2013-11-26 22:57:29 +00:00
|
|
|
|
sec = 59;
|
2013-11-26 22:56:50 +00:00
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Invert CONVERT by probing. First assume the same offset as last
|
|
|
|
|
time. */
|
|
|
|
|
|
|
|
|
|
t0 = ydhms_diff (year, yday, hour, min, sec,
|
2013-11-26 22:57:29 +00:00
|
|
|
|
EPOCH_YEAR - TM_YEAR_BASE, 0, 0, 0, - guessed_offset);
|
2013-11-26 22:56:50 +00:00
|
|
|
|
|
|
|
|
|
if (TIME_T_MAX / INT_MAX / 366 / 24 / 60 / 60 < 3)
|
|
|
|
|
{
|
|
|
|
|
/* time_t isn't large enough to rule out overflows, so check
|
2013-11-26 22:57:29 +00:00
|
|
|
|
for major overflows. A gross check suffices, since if t0
|
|
|
|
|
has overflowed, it is off by a multiple of TIME_T_MAX -
|
|
|
|
|
TIME_T_MIN + 1. So ignore any component of the difference
|
|
|
|
|
that is bounded by a small value. */
|
2013-11-26 22:56:50 +00:00
|
|
|
|
|
|
|
|
|
/* Approximate log base 2 of the number of time units per
|
2013-11-26 22:57:29 +00:00
|
|
|
|
biennium. A biennium is 2 years; use this unit instead of
|
|
|
|
|
years to avoid integer overflow. For example, 2 average
|
|
|
|
|
Gregorian years are 2 * 365.2425 * 24 * 60 * 60 seconds,
|
|
|
|
|
which is 63113904 seconds, and rint (log2 (63113904)) is
|
|
|
|
|
26. */
|
2013-11-26 22:56:50 +00:00
|
|
|
|
int ALOG2_SECONDS_PER_BIENNIUM = 26;
|
|
|
|
|
int ALOG2_MINUTES_PER_BIENNIUM = 20;
|
|
|
|
|
int ALOG2_HOURS_PER_BIENNIUM = 14;
|
|
|
|
|
int ALOG2_DAYS_PER_BIENNIUM = 10;
|
|
|
|
|
int LOG2_YEARS_PER_BIENNIUM = 1;
|
|
|
|
|
|
|
|
|
|
int approx_requested_biennia =
|
2013-11-26 22:57:29 +00:00
|
|
|
|
(SHR (year_requested, LOG2_YEARS_PER_BIENNIUM)
|
|
|
|
|
- SHR (EPOCH_YEAR - TM_YEAR_BASE, LOG2_YEARS_PER_BIENNIUM)
|
|
|
|
|
+ SHR (mday, ALOG2_DAYS_PER_BIENNIUM)
|
|
|
|
|
+ SHR (hour, ALOG2_HOURS_PER_BIENNIUM)
|
|
|
|
|
+ SHR (min, ALOG2_MINUTES_PER_BIENNIUM)
|
|
|
|
|
+ (LEAP_SECONDS_POSSIBLE
|
|
|
|
|
? 0
|
|
|
|
|
: SHR (sec, ALOG2_SECONDS_PER_BIENNIUM)));
|
2013-11-26 22:56:50 +00:00
|
|
|
|
|
|
|
|
|
int approx_biennia = SHR (t0, ALOG2_SECONDS_PER_BIENNIUM);
|
|
|
|
|
int diff = approx_biennia - approx_requested_biennia;
|
|
|
|
|
int abs_diff = diff < 0 ? - diff : diff;
|
|
|
|
|
|
|
|
|
|
/* IRIX 4.0.5 cc miscaculates TIME_T_MIN / 3: it erroneously
|
2013-11-26 22:57:29 +00:00
|
|
|
|
gives a positive value of 715827882. Setting a variable
|
|
|
|
|
first then doing math on it seems to work.
|
|
|
|
|
(ghazi@caip.rutgers.edu) */
|
2013-11-26 22:56:50 +00:00
|
|
|
|
time_t time_t_max = TIME_T_MAX;
|
|
|
|
|
time_t time_t_min = TIME_T_MIN;
|
|
|
|
|
time_t overflow_threshold =
|
2013-11-26 22:57:29 +00:00
|
|
|
|
(time_t_max / 3 - time_t_min / 3) >> ALOG2_SECONDS_PER_BIENNIUM;
|
2013-11-26 22:56:50 +00:00
|
|
|
|
|
|
|
|
|
if (overflow_threshold < abs_diff)
|
2013-11-26 22:57:29 +00:00
|
|
|
|
{
|
|
|
|
|
/* Overflow occurred. Try repairing it; this might work if
|
|
|
|
|
the time zone offset is enough to undo the overflow. */
|
|
|
|
|
time_t repaired_t0 = -1 - t0;
|
|
|
|
|
approx_biennia = SHR (repaired_t0, ALOG2_SECONDS_PER_BIENNIUM);
|
|
|
|
|
diff = approx_biennia - approx_requested_biennia;
|
|
|
|
|
abs_diff = diff < 0 ? - diff : diff;
|
|
|
|
|
if (overflow_threshold < abs_diff)
|
|
|
|
|
return -1;
|
|
|
|
|
guessed_offset += repaired_t0 - t0;
|
|
|
|
|
t0 = repaired_t0;
|
|
|
|
|
}
|
2013-11-26 22:56:50 +00:00
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Repeatedly use the error to improve the guess. */
|
|
|
|
|
|
|
|
|
|
for (t = t1 = t2 = t0, dst2 = 0;
|
|
|
|
|
(gt = guess_time_tm (year, yday, hour, min, sec, &t,
|
2013-11-26 22:57:29 +00:00
|
|
|
|
ranged_convert (convert, &t, &tm)),
|
|
|
|
|
t != gt);
|
2013-11-26 22:56:50 +00:00
|
|
|
|
t1 = t2, t2 = t, t = gt, dst2 = tm.tm_isdst != 0)
|
|
|
|
|
if (t == t1 && t != t2
|
2013-11-26 22:57:29 +00:00
|
|
|
|
&& (tm.tm_isdst < 0
|
|
|
|
|
|| (isdst < 0
|
|
|
|
|
? dst2 <= (tm.tm_isdst != 0)
|
|
|
|
|
: (isdst != 0) != (tm.tm_isdst != 0))))
|
2013-11-26 22:56:50 +00:00
|
|
|
|
/* We can't possibly find a match, as we are oscillating
|
2013-11-26 22:57:29 +00:00
|
|
|
|
between two values. The requested time probably falls
|
|
|
|
|
within a spring-forward gap of size GT - T. Follow the common
|
|
|
|
|
practice in this case, which is to return a time that is GT - T
|
|
|
|
|
away from the requested time, preferring a time whose
|
|
|
|
|
tm_isdst differs from the requested value. (If no tm_isdst
|
|
|
|
|
was requested and only one of the two values has a nonzero
|
|
|
|
|
tm_isdst, prefer that value.) In practice, this is more
|
|
|
|
|
useful than returning -1. */
|
2013-11-26 22:56:50 +00:00
|
|
|
|
goto offset_found;
|
|
|
|
|
else if (--remaining_probes == 0)
|
|
|
|
|
return -1;
|
|
|
|
|
|
|
|
|
|
/* We have a match. Check whether tm.tm_isdst has the requested
|
|
|
|
|
value, if any. */
|
|
|
|
|
if (isdst != tm.tm_isdst && 0 <= isdst && 0 <= tm.tm_isdst)
|
|
|
|
|
{
|
|
|
|
|
/* tm.tm_isdst has the wrong value. Look for a neighboring
|
2013-11-26 22:57:29 +00:00
|
|
|
|
time with the right value, and use its UTC offset.
|
2013-11-26 22:56:50 +00:00
|
|
|
|
|
2013-11-26 22:57:29 +00:00
|
|
|
|
Heuristic: probe the adjacent timestamps in both directions,
|
|
|
|
|
looking for the desired isdst. This should work for all real
|
|
|
|
|
time zone histories in the tz database. */
|
2013-11-26 22:56:50 +00:00
|
|
|
|
|
|
|
|
|
/* Distance between probes when looking for a DST boundary. In
|
2013-11-26 22:57:29 +00:00
|
|
|
|
tzdata2003a, the shortest period of DST is 601200 seconds
|
|
|
|
|
(e.g., America/Recife starting 2000-10-08 01:00), and the
|
|
|
|
|
shortest period of non-DST surrounded by DST is 694800
|
|
|
|
|
seconds (Africa/Tunis starting 1943-04-17 01:00). Use the
|
|
|
|
|
minimum of these two values, so we don't miss these short
|
|
|
|
|
periods when probing. */
|
2013-11-26 22:56:50 +00:00
|
|
|
|
int stride = 601200;
|
|
|
|
|
|
|
|
|
|
/* The longest period of DST in tzdata2003a is 536454000 seconds
|
2013-11-26 22:57:29 +00:00
|
|
|
|
(e.g., America/Jujuy starting 1946-10-01 01:00). The longest
|
|
|
|
|
period of non-DST is much longer, but it makes no real sense
|
|
|
|
|
to search for more than a year of non-DST, so use the DST
|
|
|
|
|
max. */
|
2013-11-26 22:56:50 +00:00
|
|
|
|
int duration_max = 536454000;
|
|
|
|
|
|
|
|
|
|
/* Search in both directions, so the maximum distance is half
|
2013-11-26 22:57:29 +00:00
|
|
|
|
the duration; add the stride to avoid off-by-1 problems. */
|
2013-11-26 22:56:50 +00:00
|
|
|
|
int delta_bound = duration_max / 2 + stride;
|
|
|
|
|
|
|
|
|
|
int delta, direction;
|
|
|
|
|
|
|
|
|
|
for (delta = stride; delta < delta_bound; delta += stride)
|
2013-11-26 22:57:29 +00:00
|
|
|
|
for (direction = -1; direction <= 1; direction += 2)
|
|
|
|
|
{
|
|
|
|
|
time_t ot = t + delta * direction;
|
|
|
|
|
if ((ot < t) == (direction < 0))
|
|
|
|
|
{
|
|
|
|
|
struct tm otm;
|
|
|
|
|
ranged_convert (convert, &ot, &otm);
|
|
|
|
|
if (otm.tm_isdst == isdst)
|
|
|
|
|
{
|
|
|
|
|
/* We found the desired tm_isdst.
|
|
|
|
|
Extrapolate back to the desired time. */
|
|
|
|
|
t = guess_time_tm (year, yday, hour, min, sec, &ot, &otm);
|
|
|
|
|
ranged_convert (convert, &t, &tm);
|
|
|
|
|
goto offset_found;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
2013-11-26 22:56:50 +00:00
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
offset_found:
|
|
|
|
|
*offset = guessed_offset + t - t0;
|
|
|
|
|
|
|
|
|
|
if (LEAP_SECONDS_POSSIBLE && sec_requested != tm.tm_sec)
|
|
|
|
|
{
|
|
|
|
|
/* Adjust time to reflect the tm_sec requested, not the normalized value.
|
2013-11-26 22:57:29 +00:00
|
|
|
|
Also, repair any damage from a false match due to a leap second. */
|
2013-11-26 22:56:50 +00:00
|
|
|
|
int sec_adjustment = (sec == 0 && tm.tm_sec == 60) - sec;
|
|
|
|
|
t1 = t + sec_requested;
|
|
|
|
|
t2 = t1 + sec_adjustment;
|
|
|
|
|
if (((t1 < t) != (sec_requested < 0))
|
2013-11-26 22:57:29 +00:00
|
|
|
|
| ((t2 < t1) != (sec_adjustment < 0))
|
|
|
|
|
| ! convert (&t2, &tm))
|
|
|
|
|
return -1;
|
2013-11-26 22:56:50 +00:00
|
|
|
|
t = t2;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
*tp = tm;
|
|
|
|
|
return t;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/* FIXME: This should use a signed type wide enough to hold any UTC
|
|
|
|
|
offset in seconds. 'int' should be good enough for GNU code. We
|
|
|
|
|
can't fix this unilaterally though, as other modules invoke
|
|
|
|
|
__mktime_internal. */
|
|
|
|
|
static time_t localtime_offset;
|
|
|
|
|
|
|
|
|
|
/* Convert *TP to a time_t value. */
|
|
|
|
|
time_t
|
|
|
|
|
mktime (struct tm *tp)
|
|
|
|
|
{
|
|
|
|
|
#ifdef _LIBC
|
|
|
|
|
/* POSIX.1 8.1.1 requires that whenever mktime() is called, the
|
|
|
|
|
time zone names contained in the external variable `tzname' shall
|
|
|
|
|
be set as if the tzset() function had been called. */
|
|
|
|
|
__tzset ();
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
return __mktime_internal (tp, __localtime_r, &localtime_offset);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#ifdef weak_alias
|
|
|
|
|
weak_alias (mktime, timelocal)
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
#ifdef _LIBC
|
|
|
|
|
libc_hidden_def (mktime)
|
|
|
|
|
libc_hidden_weak (timelocal)
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
#if DEBUG
|
|
|
|
|
|
|
|
|
|
static int
|
|
|
|
|
not_equal_tm (const struct tm *a, const struct tm *b)
|
|
|
|
|
{
|
|
|
|
|
return ((a->tm_sec ^ b->tm_sec)
|
2013-11-26 22:57:29 +00:00
|
|
|
|
| (a->tm_min ^ b->tm_min)
|
|
|
|
|
| (a->tm_hour ^ b->tm_hour)
|
|
|
|
|
| (a->tm_mday ^ b->tm_mday)
|
|
|
|
|
| (a->tm_mon ^ b->tm_mon)
|
|
|
|
|
| (a->tm_year ^ b->tm_year)
|
|
|
|
|
| (a->tm_yday ^ b->tm_yday)
|
|
|
|
|
| (a->tm_isdst ^ b->tm_isdst));
|
2013-11-26 22:56:50 +00:00
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void
|
|
|
|
|
print_tm (const struct tm *tp)
|
|
|
|
|
{
|
|
|
|
|
if (tp)
|
|
|
|
|
printf ("%04d-%02d-%02d %02d:%02d:%02d yday %03d wday %d isdst %d",
|
2013-11-26 22:57:29 +00:00
|
|
|
|
tp->tm_year + TM_YEAR_BASE, tp->tm_mon + 1, tp->tm_mday,
|
|
|
|
|
tp->tm_hour, tp->tm_min, tp->tm_sec,
|
|
|
|
|
tp->tm_yday, tp->tm_wday, tp->tm_isdst);
|
2013-11-26 22:56:50 +00:00
|
|
|
|
else
|
|
|
|
|
printf ("0");
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int
|
|
|
|
|
check_result (time_t tk, struct tm tmk, time_t tl, const struct tm *lt)
|
|
|
|
|
{
|
|
|
|
|
if (tk != tl || !lt || not_equal_tm (&tmk, lt))
|
|
|
|
|
{
|
|
|
|
|
printf ("mktime (");
|
|
|
|
|
print_tm (lt);
|
|
|
|
|
printf (")\nyields (");
|
|
|
|
|
print_tm (&tmk);
|
|
|
|
|
printf (") == %ld, should be %ld\n", (long int) tk, (long int) tl);
|
|
|
|
|
return 1;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
int
|
|
|
|
|
main (int argc, char **argv)
|
|
|
|
|
{
|
|
|
|
|
int status = 0;
|
|
|
|
|
struct tm tm, tmk, tml;
|
|
|
|
|
struct tm *lt;
|
|
|
|
|
time_t tk, tl, tl1;
|
|
|
|
|
char trailer;
|
|
|
|
|
|
|
|
|
|
if ((argc == 3 || argc == 4)
|
|
|
|
|
&& (sscanf (argv[1], "%d-%d-%d%c",
|
2013-11-26 22:57:29 +00:00
|
|
|
|
&tm.tm_year, &tm.tm_mon, &tm.tm_mday, &trailer)
|
|
|
|
|
== 3)
|
2013-11-26 22:56:50 +00:00
|
|
|
|
&& (sscanf (argv[2], "%d:%d:%d%c",
|
2013-11-26 22:57:29 +00:00
|
|
|
|
&tm.tm_hour, &tm.tm_min, &tm.tm_sec, &trailer)
|
|
|
|
|
== 3))
|
2013-11-26 22:56:50 +00:00
|
|
|
|
{
|
|
|
|
|
tm.tm_year -= TM_YEAR_BASE;
|
|
|
|
|
tm.tm_mon--;
|
|
|
|
|
tm.tm_isdst = argc == 3 ? -1 : atoi (argv[3]);
|
|
|
|
|
tmk = tm;
|
|
|
|
|
tl = mktime (&tmk);
|
|
|
|
|
lt = localtime (&tl);
|
|
|
|
|
if (lt)
|
2013-11-26 22:57:29 +00:00
|
|
|
|
{
|
|
|
|
|
tml = *lt;
|
|
|
|
|
lt = &tml;
|
|
|
|
|
}
|
2013-11-26 22:56:50 +00:00
|
|
|
|
printf ("mktime returns %ld == ", (long int) tl);
|
|
|
|
|
print_tm (&tmk);
|
|
|
|
|
printf ("\n");
|
|
|
|
|
status = check_result (tl, tmk, tl, lt);
|
|
|
|
|
}
|
|
|
|
|
else if (argc == 4 || (argc == 5 && strcmp (argv[4], "-") == 0))
|
|
|
|
|
{
|
|
|
|
|
time_t from = atol (argv[1]);
|
|
|
|
|
time_t by = atol (argv[2]);
|
|
|
|
|
time_t to = atol (argv[3]);
|
|
|
|
|
|
|
|
|
|
if (argc == 4)
|
2013-11-26 22:57:29 +00:00
|
|
|
|
for (tl = from; by < 0 ? to <= tl : tl <= to; tl = tl1)
|
|
|
|
|
{
|
|
|
|
|
lt = localtime (&tl);
|
|
|
|
|
if (lt)
|
|
|
|
|
{
|
|
|
|
|
tmk = tml = *lt;
|
|
|
|
|
tk = mktime (&tmk);
|
|
|
|
|
status |= check_result (tk, tmk, tl, &tml);
|
|
|
|
|
}
|
|
|
|
|
else
|
|
|
|
|
{
|
|
|
|
|
printf ("localtime (%ld) yields 0\n", (long int) tl);
|
|
|
|
|
status = 1;
|
|
|
|
|
}
|
|
|
|
|
tl1 = tl + by;
|
|
|
|
|
if ((tl1 < tl) != (by < 0))
|
|
|
|
|
break;
|
|
|
|
|
}
|
2013-11-26 22:56:50 +00:00
|
|
|
|
else
|
2013-11-26 22:57:29 +00:00
|
|
|
|
for (tl = from; by < 0 ? to <= tl : tl <= to; tl = tl1)
|
|
|
|
|
{
|
|
|
|
|
/* Null benchmark. */
|
|
|
|
|
lt = localtime (&tl);
|
|
|
|
|
if (lt)
|
|
|
|
|
{
|
|
|
|
|
tmk = tml = *lt;
|
|
|
|
|
tk = tl;
|
|
|
|
|
status |= check_result (tk, tmk, tl, &tml);
|
|
|
|
|
}
|
|
|
|
|
else
|
|
|
|
|
{
|
|
|
|
|
printf ("localtime (%ld) yields 0\n", (long int) tl);
|
|
|
|
|
status = 1;
|
|
|
|
|
}
|
|
|
|
|
tl1 = tl + by;
|
|
|
|
|
if ((tl1 < tl) != (by < 0))
|
|
|
|
|
break;
|
|
|
|
|
}
|
2013-11-26 22:56:50 +00:00
|
|
|
|
}
|
|
|
|
|
else
|
|
|
|
|
printf ("Usage:\
|
|
|
|
|
\t%s YYYY-MM-DD HH:MM:SS [ISDST] # Test given time.\n\
|
|
|
|
|
\t%s FROM BY TO # Test values FROM, FROM+BY, ..., TO.\n\
|
|
|
|
|
\t%s FROM BY TO - # Do not test those values (for benchmark).\n",
|
2013-11-26 22:57:29 +00:00
|
|
|
|
argv[0], argv[0], argv[0]);
|
2013-11-26 22:56:50 +00:00
|
|
|
|
|
|
|
|
|
return status;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#endif /* DEBUG */
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
Local Variables:
|
|
|
|
|
compile-command: "gcc -DDEBUG -Wall -W -O -g mktime.c -o mktime"
|
|
|
|
|
End:
|
|
|
|
|
*/
|