Imported Upstream version 1.4.16+git20130902
This commit is contained in:
parent
e76be63abf
commit
e70fb8c051
517 changed files with 44015 additions and 43295 deletions
542
gl/mktime.c
542
gl/mktime.c
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@ -1,21 +1,21 @@
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/* Convert a `struct tm' to a time_t value.
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Copyright (C) 1993-1999, 2002-2007, 2009-2010 Free Software Foundation, Inc.
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/* Convert a 'struct tm' to a time_t value.
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Copyright (C) 1993-2013 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Paul Eggert <eggert@twinsun.com>.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public
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License as published by the Free Software Foundation; either
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version 3 of the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License along
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with this program; if not, write to the Free Software Foundation,
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Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
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You should have received a copy of the GNU General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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/* Define this to have a standalone program to test this implementation of
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mktime. */
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@ -26,7 +26,7 @@
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#endif
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/* Assume that leap seconds are possible, unless told otherwise.
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If the host has a `zic' command with a `-L leapsecondfilename' option,
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If the host has a 'zic' command with a '-L leapsecondfilename' option,
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then it supports leap seconds; otherwise it probably doesn't. */
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#ifndef LEAP_SECONDS_POSSIBLE
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# define LEAP_SECONDS_POSSIBLE 1
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@ -36,15 +36,49 @@
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#include <limits.h>
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#include <string.h> /* For the real memcpy prototype. */
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#include <string.h> /* For the real memcpy prototype. */
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#if DEBUG
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# include <stdio.h>
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# include <stdlib.h>
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/* Make it work even if the system's libc has its own mktime routine. */
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# undef mktime
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# define mktime my_mktime
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#endif /* DEBUG */
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/* Some of the code in this file assumes that signed integer overflow
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silently wraps around. This assumption can't easily be programmed
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around, nor can it be checked for portably at compile-time or
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easily eliminated at run-time.
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Define WRAPV to 1 if the assumption is valid and if
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#pragma GCC optimize ("wrapv")
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does not trigger GCC bug 51793
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<http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51793>.
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Otherwise, define it to 0; this forces the use of slower code that,
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while not guaranteed by the C Standard, works on all production
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platforms that we know about. */
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#ifndef WRAPV
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# if (((__GNUC__ == 4 && 4 <= __GNUC_MINOR__) || 4 < __GNUC__) \
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&& defined __GLIBC__)
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# pragma GCC optimize ("wrapv")
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# define WRAPV 1
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# else
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# define WRAPV 0
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# endif
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#endif
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/* Verify a requirement at compile-time (unlike assert, which is runtime). */
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#define verify(name, assertion) struct name { char a[(assertion) ? 1 : -1]; }
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/* A signed type that is at least one bit wider than int. */
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#if INT_MAX <= LONG_MAX / 2
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typedef long int long_int;
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#else
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typedef long long int long_int;
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#endif
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verify (long_int_is_wide_enough, INT_MAX == INT_MAX * (long_int) 2 / 2);
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/* Shift A right by B bits portably, by dividing A by 2**B and
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truncating towards minus infinity. A and B should be free of side
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effects, and B should be in the range 0 <= B <= INT_BITS - 2, where
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implementations (e.g., UNICOS 9.0 on a Cray Y-MP EL) don't shift
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right in the usual way when A < 0, so SHR falls back on division if
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ordinary A >> B doesn't seem to be the usual signed shift. */
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#define SHR(a, b) \
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(-1 >> 1 == -1 \
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? (a) >> (b) \
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#define SHR(a, b) \
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((-1 >> 1 == -1 \
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&& (long_int) -1 >> 1 == -1 \
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&& ((time_t) -1 >> 1 == -1 || ! TYPE_SIGNED (time_t))) \
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? (a) >> (b) \
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: (a) / (1 << (b)) - ((a) % (1 << (b)) < 0))
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/* The extra casts in the following macros work around compiler bugs,
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#define TYPE_IS_INTEGER(t) ((t) 1.5 == 1)
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/* True if negative values of the signed integer type T use two's
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complement, ones' complement, or signed magnitude representation,
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respectively. Much GNU code assumes two's complement, but some
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people like to be portable to all possible C hosts. */
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complement, or if T is an unsigned integer type. */
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#define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1)
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#define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0)
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#define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1)
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/* True if the arithmetic type T is signed. */
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#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
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@ -84,14 +116,12 @@
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your host. */
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#define TYPE_MINIMUM(t) \
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((t) (! TYPE_SIGNED (t) \
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? (t) 0 \
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: TYPE_SIGNED_MAGNITUDE (t) \
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? ~ (t) 0 \
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: ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1)))
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? (t) 0 \
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: ~ TYPE_MAXIMUM (t)))
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#define TYPE_MAXIMUM(t) \
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((t) (! TYPE_SIGNED (t) \
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? (t) -1 \
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: ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))))
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? (t) -1 \
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: ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1)))
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#ifndef TIME_T_MIN
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# define TIME_T_MIN TYPE_MINIMUM (time_t)
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@ -101,29 +131,26 @@
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#endif
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#define TIME_T_MIDPOINT (SHR (TIME_T_MIN + TIME_T_MAX, 1) + 1)
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/* Verify a requirement at compile-time (unlike assert, which is runtime). */
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#define verify(name, assertion) struct name { char a[(assertion) ? 1 : -1]; }
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verify (time_t_is_integer, TYPE_IS_INTEGER (time_t));
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verify (twos_complement_arithmetic, TYPE_TWOS_COMPLEMENT (int));
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/* The code also assumes that signed integer overflow silently wraps
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around, but this assumption can't be stated without causing a
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diagnostic on some hosts. */
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verify (twos_complement_arithmetic,
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(TYPE_TWOS_COMPLEMENT (int)
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&& TYPE_TWOS_COMPLEMENT (long_int)
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&& TYPE_TWOS_COMPLEMENT (time_t)));
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#define EPOCH_YEAR 1970
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#define TM_YEAR_BASE 1900
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verify (base_year_is_a_multiple_of_100, TM_YEAR_BASE % 100 == 0);
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/* Return 1 if YEAR + TM_YEAR_BASE is a leap year. */
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static inline int
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leapyear (long int year)
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static int
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leapyear (long_int year)
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{
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/* Don't add YEAR to TM_YEAR_BASE, as that might overflow.
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Also, work even if YEAR is negative. */
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return
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((year & 3) == 0
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&& (year % 100 != 0
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|| ((year / 100) & 3) == (- (TM_YEAR_BASE / 100) & 3)));
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|| ((year / 100) & 3) == (- (TM_YEAR_BASE / 100) & 3)));
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}
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/* How many days come before each month (0-12). */
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@ -150,6 +177,14 @@ const unsigned short int __mon_yday[2][13] =
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# include "mktime-internal.h"
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#endif
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/* Return 1 if the values A and B differ according to the rules for
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tm_isdst: A and B differ if one is zero and the other positive. */
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static int
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isdst_differ (int a, int b)
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{
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return (!a != !b) && (0 <= a) && (0 <= b);
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}
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/* Return an integer value measuring (YEAR1-YDAY1 HOUR1:MIN1:SEC1) -
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(YEAR0-YDAY0 HOUR0:MIN0:SEC0) in seconds, assuming that the clocks
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were not adjusted between the time stamps.
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The result may overflow. It is the caller's responsibility to
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detect overflow. */
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static inline time_t
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ydhms_diff (long int year1, long int yday1, int hour1, int min1, int sec1,
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int year0, int yday0, int hour0, int min0, int sec0)
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static time_t
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ydhms_diff (long_int year1, long_int yday1, int hour1, int min1, int sec1,
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int year0, int yday0, int hour0, int min0, int sec0)
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{
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verify (C99_integer_division, -1 / 2 == 0);
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#if 0 /* This assertion fails on 32-bit systems with 64-bit time_t, such as
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NetBSD 5 on i386. */
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verify (long_int_year_and_yday_are_wide_enough,
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INT_MAX <= LONG_MAX / 2 || TIME_T_MAX <= UINT_MAX);
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#endif
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/* Compute intervening leap days correctly even if year is negative.
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Take care to avoid integer overflow here. */
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return seconds;
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}
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/* Return the average of A and B, even if A + B would overflow. */
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static time_t
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time_t_avg (time_t a, time_t b)
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{
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return SHR (a, 1) + SHR (b, 1) + (a & b & 1);
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}
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/* Return 1 if A + B does not overflow. If time_t is unsigned and if
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B's top bit is set, assume that the sum represents A - -B, and
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return 1 if the subtraction does not wrap around. */
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static int
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time_t_add_ok (time_t a, time_t b)
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{
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if (! TYPE_SIGNED (time_t))
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{
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time_t sum = a + b;
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return (sum < a) == (TIME_T_MIDPOINT <= b);
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}
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else if (WRAPV)
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{
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time_t sum = a + b;
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return (sum < a) == (b < 0);
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}
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else
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{
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time_t avg = time_t_avg (a, b);
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return TIME_T_MIN / 2 <= avg && avg <= TIME_T_MAX / 2;
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}
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}
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/* Return 1 if A + B does not overflow. */
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static int
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time_t_int_add_ok (time_t a, int b)
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{
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verify (int_no_wider_than_time_t, INT_MAX <= TIME_T_MAX);
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if (WRAPV)
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{
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time_t sum = a + b;
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return (sum < a) == (b < 0);
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}
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else
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{
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int a_odd = a & 1;
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time_t avg = SHR (a, 1) + (SHR (b, 1) + (a_odd & b));
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return TIME_T_MIN / 2 <= avg && avg <= TIME_T_MAX / 2;
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}
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}
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/* Return a time_t value corresponding to (YEAR-YDAY HOUR:MIN:SEC),
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assuming that *T corresponds to *TP and that no clock adjustments
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If overflow occurs, yield the minimal or maximal value, except do not
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yield a value equal to *T. */
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static time_t
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guess_time_tm (long int year, long int yday, int hour, int min, int sec,
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const time_t *t, const struct tm *tp)
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guess_time_tm (long_int year, long_int yday, int hour, int min, int sec,
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const time_t *t, const struct tm *tp)
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{
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if (tp)
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{
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time_t d = ydhms_diff (year, yday, hour, min, sec,
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tp->tm_year, tp->tm_yday,
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tp->tm_hour, tp->tm_min, tp->tm_sec);
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time_t t1 = *t + d;
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if ((t1 < *t) == (TYPE_SIGNED (time_t) ? d < 0 : TIME_T_MAX / 2 < d))
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return t1;
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tp->tm_year, tp->tm_yday,
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tp->tm_hour, tp->tm_min, tp->tm_sec);
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if (time_t_add_ok (*t, d))
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return *t + d;
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}
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/* Overflow occurred one way or another. Return the nearest result
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match; and don't oscillate between two values, as that would
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confuse the spring-forward gap detector. */
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return (*t < TIME_T_MIDPOINT
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? (*t <= TIME_T_MIN + 1 ? *t + 1 : TIME_T_MIN)
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: (TIME_T_MAX - 1 <= *t ? *t - 1 : TIME_T_MAX));
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? (*t <= TIME_T_MIN + 1 ? *t + 1 : TIME_T_MIN)
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: (TIME_T_MAX - 1 <= *t ? *t - 1 : TIME_T_MAX));
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}
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/* Use CONVERT to convert *T to a broken down time in *TP.
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@ -229,7 +305,7 @@ guess_time_tm (long int year, long int yday, int hour, int min, int sec,
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it is the nearest in-range value and then convert that. */
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static struct tm *
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ranged_convert (struct tm *(*convert) (const time_t *, struct tm *),
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time_t *t, struct tm *tp)
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time_t *t, struct tm *tp)
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{
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struct tm *r = convert (t, tp);
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@ -239,27 +315,25 @@ ranged_convert (struct tm *(*convert) (const time_t *, struct tm *),
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time_t ok = 0;
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/* BAD is a known unconvertible time_t, and OK is a known good one.
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Use binary search to narrow the range between BAD and OK until
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they differ by 1. */
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Use binary search to narrow the range between BAD and OK until
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they differ by 1. */
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while (bad != ok + (bad < 0 ? -1 : 1))
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{
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time_t mid = *t = (bad < 0
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? bad + ((ok - bad) >> 1)
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: ok + ((bad - ok) >> 1));
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r = convert (t, tp);
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if (r)
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ok = mid;
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else
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bad = mid;
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}
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{
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time_t mid = *t = time_t_avg (ok, bad);
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r = convert (t, tp);
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if (r)
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ok = mid;
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else
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bad = mid;
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}
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if (!r && ok)
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{
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/* The last conversion attempt failed;
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revert to the most recent successful attempt. */
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*t = ok;
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r = convert (t, tp);
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}
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{
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/* The last conversion attempt failed;
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revert to the most recent successful attempt. */
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*t = ok;
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r = convert (t, tp);
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}
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}
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return r;
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@ -274,8 +348,8 @@ ranged_convert (struct tm *(*convert) (const time_t *, struct tm *),
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This function is external because it is used also by timegm.c. */
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time_t
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__mktime_internal (struct tm *tp,
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struct tm *(*convert) (const time_t *, struct tm *),
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time_t *offset)
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struct tm *(*convert) (const time_t *, struct tm *),
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time_t *offset)
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{
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time_t t, gt, t0, t1, t2;
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struct tm tm;
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@ -294,9 +368,7 @@ __mktime_internal (struct tm *tp,
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int mday = tp->tm_mday;
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int mon = tp->tm_mon;
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int year_requested = tp->tm_year;
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/* Normalize the value. */
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int isdst = ((tp->tm_isdst >> (8 * sizeof (tp->tm_isdst) - 1))
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| (tp->tm_isdst != 0));
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int isdst = tp->tm_isdst;
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/* 1 if the previous probe was DST. */
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int dst2;
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@ -305,8 +377,8 @@ __mktime_internal (struct tm *tp,
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int mon_remainder = mon % 12;
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int negative_mon_remainder = mon_remainder < 0;
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int mon_years = mon / 12 - negative_mon_remainder;
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long int lyear_requested = year_requested;
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long int year = lyear_requested + mon_years;
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long_int lyear_requested = year_requested;
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long_int year = lyear_requested + mon_years;
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/* The other values need not be in range:
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the remaining code handles minor overflows correctly,
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@ -316,10 +388,10 @@ __mktime_internal (struct tm *tp,
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/* Calculate day of year from year, month, and day of month.
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The result need not be in range. */
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int mon_yday = ((__mon_yday[leapyear (year)]
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[mon_remainder + 12 * negative_mon_remainder])
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- 1);
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long int lmday = mday;
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long int yday = mon_yday + lmday;
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[mon_remainder + 12 * negative_mon_remainder])
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- 1);
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long_int lmday = mday;
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long_int yday = mon_yday + lmday;
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time_t guessed_offset = *offset;
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@ -328,33 +400,33 @@ __mktime_internal (struct tm *tp,
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if (LEAP_SECONDS_POSSIBLE)
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{
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/* Handle out-of-range seconds specially,
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since ydhms_tm_diff assumes every minute has 60 seconds. */
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since ydhms_tm_diff assumes every minute has 60 seconds. */
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if (sec < 0)
|
||||
sec = 0;
|
||||
sec = 0;
|
||||
if (59 < sec)
|
||||
sec = 59;
|
||||
sec = 59;
|
||||
}
|
||||
|
||||
/* Invert CONVERT by probing. First assume the same offset as last
|
||||
time. */
|
||||
|
||||
t0 = ydhms_diff (year, yday, hour, min, sec,
|
||||
EPOCH_YEAR - TM_YEAR_BASE, 0, 0, 0, - guessed_offset);
|
||||
EPOCH_YEAR - TM_YEAR_BASE, 0, 0, 0, - guessed_offset);
|
||||
|
||||
if (TIME_T_MAX / INT_MAX / 366 / 24 / 60 / 60 < 3)
|
||||
{
|
||||
/* time_t isn't large enough to rule out overflows, so check
|
||||
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. */
|
||||
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. */
|
||||
|
||||
/* Approximate log base 2 of the number of time units per
|
||||
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. */
|
||||
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. */
|
||||
int ALOG2_SECONDS_PER_BIENNIUM = 26;
|
||||
int ALOG2_MINUTES_PER_BIENNIUM = 20;
|
||||
int ALOG2_HOURS_PER_BIENNIUM = 14;
|
||||
|
@ -362,119 +434,117 @@ __mktime_internal (struct tm *tp,
|
|||
int LOG2_YEARS_PER_BIENNIUM = 1;
|
||||
|
||||
int approx_requested_biennia =
|
||||
(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)));
|
||||
(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)));
|
||||
|
||||
int approx_biennia = SHR (t0, ALOG2_SECONDS_PER_BIENNIUM);
|
||||
int diff = approx_biennia - approx_requested_biennia;
|
||||
int abs_diff = diff < 0 ? - diff : diff;
|
||||
int approx_abs_diff = diff < 0 ? -1 - diff : diff;
|
||||
|
||||
/* IRIX 4.0.5 cc miscaculates TIME_T_MIN / 3: it erroneously
|
||||
gives a positive value of 715827882. Setting a variable
|
||||
first then doing math on it seems to work.
|
||||
(ghazi@caip.rutgers.edu) */
|
||||
/* IRIX 4.0.5 cc miscalculates TIME_T_MIN / 3: it erroneously
|
||||
gives a positive value of 715827882. Setting a variable
|
||||
first then doing math on it seems to work.
|
||||
(ghazi@caip.rutgers.edu) */
|
||||
time_t time_t_max = TIME_T_MAX;
|
||||
time_t time_t_min = TIME_T_MIN;
|
||||
time_t overflow_threshold =
|
||||
(time_t_max / 3 - time_t_min / 3) >> ALOG2_SECONDS_PER_BIENNIUM;
|
||||
(time_t_max / 3 - time_t_min / 3) >> ALOG2_SECONDS_PER_BIENNIUM;
|
||||
|
||||
if (overflow_threshold < abs_diff)
|
||||
{
|
||||
/* 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;
|
||||
}
|
||||
if (overflow_threshold < approx_abs_diff)
|
||||
{
|
||||
/* 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;
|
||||
approx_abs_diff = diff < 0 ? -1 - diff : diff;
|
||||
if (overflow_threshold < approx_abs_diff)
|
||||
return -1;
|
||||
guessed_offset += repaired_t0 - t0;
|
||||
t0 = repaired_t0;
|
||||
}
|
||||
}
|
||||
|
||||
/* 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,
|
||||
ranged_convert (convert, &t, &tm)),
|
||||
t != gt);
|
||||
ranged_convert (convert, &t, &tm)),
|
||||
t != gt);
|
||||
t1 = t2, t2 = t, t = gt, dst2 = tm.tm_isdst != 0)
|
||||
if (t == t1 && t != t2
|
||||
&& (tm.tm_isdst < 0
|
||||
|| (isdst < 0
|
||||
? dst2 <= (tm.tm_isdst != 0)
|
||||
: (isdst != 0) != (tm.tm_isdst != 0))))
|
||||
&& (tm.tm_isdst < 0
|
||||
|| (isdst < 0
|
||||
? dst2 <= (tm.tm_isdst != 0)
|
||||
: (isdst != 0) != (tm.tm_isdst != 0))))
|
||||
/* We can't possibly find a match, as we are oscillating
|
||||
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. */
|
||||
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. */
|
||||
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)
|
||||
if (isdst_differ (isdst, tm.tm_isdst))
|
||||
{
|
||||
/* tm.tm_isdst has the wrong value. Look for a neighboring
|
||||
time with the right value, and use its UTC offset.
|
||||
time with the right value, and use its UTC offset.
|
||||
|
||||
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. */
|
||||
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. */
|
||||
|
||||
/* Distance between probes when looking for a DST boundary. In
|
||||
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. */
|
||||
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. */
|
||||
int stride = 601200;
|
||||
|
||||
/* The longest period of DST in tzdata2003a is 536454000 seconds
|
||||
(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. */
|
||||
(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. */
|
||||
int duration_max = 536454000;
|
||||
|
||||
/* Search in both directions, so the maximum distance is half
|
||||
the duration; add the stride to avoid off-by-1 problems. */
|
||||
the duration; add the stride to avoid off-by-1 problems. */
|
||||
int delta_bound = duration_max / 2 + stride;
|
||||
|
||||
int delta, direction;
|
||||
|
||||
for (delta = stride; delta < delta_bound; delta += stride)
|
||||
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;
|
||||
}
|
||||
}
|
||||
}
|
||||
for (direction = -1; direction <= 1; direction += 2)
|
||||
if (time_t_int_add_ok (t, delta * direction))
|
||||
{
|
||||
time_t ot = t + delta * direction;
|
||||
struct tm otm;
|
||||
ranged_convert (convert, &ot, &otm);
|
||||
if (! isdst_differ (isdst, otm.tm_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;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
offset_found:
|
||||
|
@ -483,14 +553,16 @@ __mktime_internal (struct tm *tp,
|
|||
if (LEAP_SECONDS_POSSIBLE && sec_requested != tm.tm_sec)
|
||||
{
|
||||
/* Adjust time to reflect the tm_sec requested, not the normalized value.
|
||||
Also, repair any damage from a false match due to a leap second. */
|
||||
Also, repair any damage from a false match due to a leap second. */
|
||||
int sec_adjustment = (sec == 0 && tm.tm_sec == 60) - sec;
|
||||
if (! time_t_int_add_ok (t, sec_requested))
|
||||
return -1;
|
||||
t1 = t + sec_requested;
|
||||
if (! time_t_int_add_ok (t1, sec_adjustment))
|
||||
return -1;
|
||||
t2 = t1 + sec_adjustment;
|
||||
if (((t1 < t) != (sec_requested < 0))
|
||||
| ((t2 < t1) != (sec_adjustment < 0))
|
||||
| ! convert (&t2, &tm))
|
||||
return -1;
|
||||
if (! convert (&t2, &tm))
|
||||
return -1;
|
||||
t = t2;
|
||||
}
|
||||
|
||||
|
@ -511,7 +583,7 @@ 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
|
||||
time zone names contained in the external variable 'tzname' shall
|
||||
be set as if the tzset() function had been called. */
|
||||
__tzset ();
|
||||
#endif
|
||||
|
@ -534,13 +606,13 @@ static int
|
|||
not_equal_tm (const struct tm *a, const struct tm *b)
|
||||
{
|
||||
return ((a->tm_sec ^ b->tm_sec)
|
||||
| (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));
|
||||
| (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)
|
||||
| isdst_differ (a->tm_isdst, b->tm_isdst));
|
||||
}
|
||||
|
||||
static void
|
||||
|
@ -548,9 +620,9 @@ print_tm (const struct tm *tp)
|
|||
{
|
||||
if (tp)
|
||||
printf ("%04d-%02d-%02d %02d:%02d:%02d yday %03d wday %d isdst %d",
|
||||
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);
|
||||
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);
|
||||
else
|
||||
printf ("0");
|
||||
}
|
||||
|
@ -582,11 +654,11 @@ main (int argc, char **argv)
|
|||
|
||||
if ((argc == 3 || argc == 4)
|
||||
&& (sscanf (argv[1], "%d-%d-%d%c",
|
||||
&tm.tm_year, &tm.tm_mon, &tm.tm_mday, &trailer)
|
||||
== 3)
|
||||
&tm.tm_year, &tm.tm_mon, &tm.tm_mday, &trailer)
|
||||
== 3)
|
||||
&& (sscanf (argv[2], "%d:%d:%d%c",
|
||||
&tm.tm_hour, &tm.tm_min, &tm.tm_sec, &trailer)
|
||||
== 3))
|
||||
&tm.tm_hour, &tm.tm_min, &tm.tm_sec, &trailer)
|
||||
== 3))
|
||||
{
|
||||
tm.tm_year -= TM_YEAR_BASE;
|
||||
tm.tm_mon--;
|
||||
|
@ -595,10 +667,10 @@ main (int argc, char **argv)
|
|||
tl = mktime (&tmk);
|
||||
lt = localtime (&tl);
|
||||
if (lt)
|
||||
{
|
||||
tml = *lt;
|
||||
lt = &tml;
|
||||
}
|
||||
{
|
||||
tml = *lt;
|
||||
lt = &tml;
|
||||
}
|
||||
printf ("mktime returns %ld == ", (long int) tl);
|
||||
print_tm (&tmk);
|
||||
printf ("\n");
|
||||
|
@ -611,51 +683,51 @@ main (int argc, char **argv)
|
|||
time_t to = atol (argv[3]);
|
||||
|
||||
if (argc == 4)
|
||||
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;
|
||||
}
|
||||
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;
|
||||
}
|
||||
else
|
||||
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;
|
||||
}
|
||||
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;
|
||||
}
|
||||
}
|
||||
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",
|
||||
argv[0], argv[0], argv[0]);
|
||||
argv[0], argv[0], argv[0]);
|
||||
|
||||
return status;
|
||||
}
|
||||
|
@ -664,6 +736,6 @@ main (int argc, char **argv)
|
|||
|
||||
/*
|
||||
Local Variables:
|
||||
compile-command: "gcc -DDEBUG -Wall -W -O -g mktime.c -o mktime"
|
||||
compile-command: "gcc -DDEBUG -I. -Wall -W -O2 -g mktime.c -o mktime"
|
||||
End:
|
||||
*/
|
||||
|
|
Loading…
Add table
Add a link
Reference in a new issue