diff options
Diffstat (limited to 'missing_d/mktime.c')
| -rw-r--r-- | missing_d/mktime.c | 722 |
1 files changed, 498 insertions, 224 deletions
diff --git a/missing_d/mktime.c b/missing_d/mktime.c index d394ef17..17538a39 100644 --- a/missing_d/mktime.c +++ b/missing_d/mktime.c @@ -1,41 +1,50 @@ -/* Copyright (C) 1993, 1994, 1995, 1996, 1997 Free Software Foundation, Inc. +/* Convert a 'struct tm' to a time_t value. + Copyright (C) 1993-2018 Free Software Foundation, Inc. This file is part of the GNU C Library. - Contributed by Paul Eggert (eggert@twinsun.com). + Contributed by Paul Eggert <eggert@twinsun.com>. The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Library General Public License as - published by the Free Software Foundation; either version 3 of the - License, or (at your option) any later version. + 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 - Library General Public License for more details. + Lesser General Public License for more details. - You should have received a copy of the GNU Library General Public - License along with the GNU C Library; see the file COPYING.LIB. If not, - write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, - Boston, MA 02110-1301, USA. */ + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ -/* Define this to have a standalone program to test this implementation of +/* Define this to 1 to have a standalone program to test this implementation of mktime. */ -/* #define DEBUG 1 */ - -#ifdef HAVE_CONFIG_H -#include <config.h> +#ifndef DEBUG_MKTIME +# define DEBUG_MKTIME 0 #endif -#ifdef _LIBC -# define HAVE_LIMITS_H 1 -# define HAVE_LOCALTIME_R 1 -# define STDC_HEADERS 1 +/* The following macros influence what gets defined when this file is compiled: + + Macro/expression Which gnulib module This compilation unit + should define + + NEED_MKTIME_WORKING mktime rpl_mktime + || NEED_MKTIME_WINDOWS + + NEED_MKTIME_INTERNAL mktime-internal mktime_internal + + DEBUG_MKTIME (defined manually) my_mktime, main + */ + +#if !defined _LIBC && !DEBUG_MKTIME +# 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, + 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 +# define LEAP_SECONDS_POSSIBLE 1 #endif #ifndef VMS @@ -48,54 +57,99 @@ #if HAVE_LIMITS_H #include <limits.h> #endif - -#if DEBUG -#include <stdio.h> -#if STDC_HEADERS -#include <stdlib.h> +#if HAVE_STDBOOL_H +#include <stdbool.h> #endif -/* Make it work even if the system's libc has its own mktime routine. */ -#define mktime my_mktime -#endif /* DEBUG */ -#ifndef __P -#if defined (__GNUC__) || (defined (__STDC__) && __STDC__) -#define __P(args) args -#else -#define __P(args) () -#endif /* GCC. */ -#endif /* Not __P. */ +#include <intprops.h> +#include <verify.h> -#ifndef CHAR_BIT -#define CHAR_BIT 8 +#if DEBUG_MKTIME +# include <stdio.h> +# include <stdlib.h> +# include <string.h> +/* Make it work even if the system's libc has its own mktime routine. */ +# undef mktime +# define mktime my_mktime #endif -#ifndef INT_MIN -#define INT_MIN (~0 << (sizeof (int) * CHAR_BIT - 1)) -#endif -#ifndef INT_MAX -#define INT_MAX (~0 - INT_MIN) +#if NEED_MKTIME_WINDOWS /* on native Windows */ +# include <stdlib.h> +# include <string.h> #endif -#ifndef TIME_T_MIN -#define TIME_T_MIN (0 < (time_t) -1 ? (time_t) 0 \ - : ~ (time_t) 0 << (sizeof (time_t) * CHAR_BIT - 1)) -#endif -#ifndef TIME_T_MAX -#define TIME_T_MAX (~ (time_t) 0 - TIME_T_MIN) +#if NEED_MKTIME_WORKING || NEED_MKTIME_INTERNAL || DEBUG_MKTIME + +/* A signed type that can represent an integer number of years + multiplied by three times the number of seconds in a year. It is + needed when converting a tm_year value times the number of seconds + in a year. The factor of three comes because these products need + to be subtracted from each other, and sometimes with an offset + added to them, without worrying about overflow. + + Much of the code uses long_int to represent time_t values, to + lessen the hassle of dealing with platforms where time_t is + unsigned, and because long_int should suffice to represent all + time_t values that mktime can generate even on platforms where + time_t is excessively wide. */ + +#if INT_MAX <= LONG_MAX / 3 / 366 / 24 / 60 / 60 +typedef long int long_int; +#else +typedef long long int long_int; #endif +verify (INT_MAX <= TYPE_MAXIMUM (long_int) / 3 / 366 / 24 / 60 / 60); + +/* Shift A right by B bits portably, by dividing A by 2**B and + truncating towards minus infinity. B should be in the range 0 <= B + <= LONG_INT_BITS - 2, where LONG_INT_BITS is the number of useful + bits in a long_int. LONG_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. */ + +static long_int +shr (long_int a, int b) +{ + long_int one = 1; + return (-one >> 1 == -1 + ? a >> b + : a / (one << b) - (a % (one << b) < 0)); +} + +/* Bounds for the intersection of time_t and long_int. */ + +static long_int const mktime_min + = ((TYPE_SIGNED (time_t) && TYPE_MINIMUM (time_t) < TYPE_MINIMUM (long_int)) + ? TYPE_MINIMUM (long_int) : TYPE_MINIMUM (time_t)); +static long_int const mktime_max + = (TYPE_MAXIMUM (long_int) < TYPE_MAXIMUM (time_t) + ? TYPE_MAXIMUM (long_int) : TYPE_MAXIMUM (time_t)); + +verify (TYPE_IS_INTEGER (time_t)); -#define TM_YEAR_BASE 1900 #define EPOCH_YEAR 1970 +#define TM_YEAR_BASE 1900 +verify (TM_YEAR_BASE % 100 == 0); -#ifndef __isleap -/* Nonzero if YEAR is a leap year (every 4 years, - except every 100th isn't, and every 400th is). */ -#define __isleap(year) \ - ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0)) -#endif +/* Is YEAR + TM_YEAR_BASE a leap year? */ +static bool +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 + || ((year / 100) & 3) == (- (TM_YEAR_BASE / 100) & 3))); +} /* How many days come before each month (0-12). */ +#ifndef _LIBC +static +#endif const unsigned short int __mon_yday[2][13] = { /* Normal years. */ @@ -104,93 +158,180 @@ const unsigned short int __mon_yday[2][13] = { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 } }; -static time_t ydhms_tm_diff __P ((int, int, int, int, int, const struct tm *)); -time_t __mktime_internal __P ((struct tm *, - struct tm *(*) (const time_t *, struct tm *), - time_t *)); +#ifdef _LIBC +typedef time_t mktime_offset_t; +#else +/* 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 +# include "mktime-internal.h" +#endif -static struct tm *my_localtime_r __P ((const time_t *, struct tm *)); -static struct tm * -my_localtime_r (t, tp) - const time_t *t; - struct tm *tp; +/* Do the values A and B differ according to the rules for tm_isdst? + A and B differ if one is zero and the other positive. */ +static bool +isdst_differ (int a, int b) { - struct tm *l = localtime (t); - if (! l) - return 0; - *tp = *l; - return tp; + return (!a != !b) && (0 <= a) && (0 <= b); } +/* 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 timestamps. + + The YEAR values uses the same numbering as TP->tm_year. Values + need not be in the usual range. However, YEAR1 must not overflow + when multiplied by three times the number of seconds in a year, and + likewise for YDAY1 and three times the number of seconds in a day. */ -/* Yield the difference between (YEAR-YDAY HOUR:MIN:SEC) and (*TP), - measured in seconds, ignoring leap seconds. - YEAR uses the same numbering as TM->tm_year. - All values are in range, except possibly YEAR. - If overflow occurs, yield the low order bits of the correct answer. */ -static time_t -ydhms_tm_diff (year, yday, hour, min, sec, tp) - int year, yday, hour, min, sec; - const struct tm *tp; +static long_int +ydhms_diff (long_int year1, long_int yday1, int hour1, int min1, int sec1, + int year0, int yday0, int hour0, int min0, int sec0) { + verify (-1 / 2 == 0); + /* Compute intervening leap days correctly even if year is negative. - Take care to avoid int overflow. time_t overflow is OK, since - only the low order bits of the correct time_t answer are needed. - Don't convert to time_t until after all divisions are done, since - time_t might be unsigned. */ - int a4 = (year >> 2) + (TM_YEAR_BASE >> 2) - ! (year & 3); - int b4 = (tp->tm_year >> 2) + (TM_YEAR_BASE >> 2) - ! (tp->tm_year & 3); + 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 = a100 >> 2; - int b400 = b100 >> 2; + int a400 = shr (a100, 2); + int b400 = shr (b100, 2); int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400); - time_t years = year - (time_t) tp->tm_year; - time_t days = (365 * years + intervening_leap_days - + (yday - tp->tm_yday)); - return (60 * (60 * (24 * days + (hour - tp->tm_hour)) - + (min - tp->tm_min)) - + (sec - tp->tm_sec)); + + /* Compute the desired time without overflowing. */ + long_int years = year1 - year0; + long_int days = 365 * years + yday1 - yday0 + intervening_leap_days; + long_int hours = 24 * days + hour1 - hour0; + long_int minutes = 60 * hours + min1 - min0; + long_int seconds = 60 * minutes + sec1 - sec0; + return seconds; +} + +/* Return the average of A and B, even if A + B would overflow. + Round toward positive infinity. */ +static long_int +long_int_avg (long_int a, long_int b) +{ + return shr (a, 1) + shr (b, 1) + ((a | b) & 1); } +/* 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. + Although T and the returned value are of type long_int, + they represent time_t values and must be in time_t range. + If TP is null, return a value not equal to T; this avoids false matches. + YEAR and YDAY must not be so large that multiplying them by three times the + number of seconds in a year (or day, respectively) would overflow long_int. + If the returned value would be out of range, yield the minimal or + maximal in-range value, except do not yield a value equal to T. */ +static long_int +guess_time_tm (long_int year, long_int yday, int hour, int min, int sec, + long_int t, const struct tm *tp) +{ + if (tp) + { + long_int result; + long_int d = ydhms_diff (year, yday, hour, min, sec, + tp->tm_year, tp->tm_yday, + tp->tm_hour, tp->tm_min, tp->tm_sec); + if (! INT_ADD_WRAPV (t, d, &result)) + return result; + } -static time_t localtime_offset; + /* 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 < long_int_avg (mktime_min, mktime_max) + ? (t <= mktime_min + 1 ? t + 1 : mktime_min) + : (mktime_max - 1 <= t ? t - 1 : mktime_max)); +} -/* Convert *TP to a time_t value. */ -time_t -mktime (tp) - struct tm *tp; +/* Use CONVERT to convert T to a struct tm value in *TM. T must be in + range for time_t. Return TM if successful, NULL if T is out of + range for CONVERT. */ +static struct tm * +convert_time (struct tm *(*convert) (const time_t *, struct tm *), + long_int t, struct tm *tm) { -#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 + time_t x = t; + return convert (&x, tm); +} + +/* 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. + A value is in range if it fits in both time_t and long_int. */ +static struct tm * +ranged_convert (struct tm *(*convert) (const time_t *, struct tm *), + long_int *t, struct tm *tp) +{ + struct tm *r; + if (*t < mktime_min) + *t = mktime_min; + else if (mktime_max < *t) + *t = mktime_max; + r = convert_time (convert, *t, tp); + + if (!r && *t) + { + long_int bad = *t; + long_int ok = 0; + + /* BAD is a known unconvertible value, and OK is a known good one. + Use binary search to narrow the range between BAD and OK until + they differ by 1. */ + while (true) + { + long_int mid = long_int_avg (ok, bad); + if (mid != ok && mid != bad) + break; + r = convert_time (convert, mid, tp); + if (r) + ok = mid; + else + bad = mid; + } + + if (!r && ok) + { + /* The last conversion attempt failed; + revert to the most recent successful attempt. */ + r = convert_time (convert, ok, tp); + } + } - return __mktime_internal (tp, my_localtime_r, &localtime_offset); + 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. */ + 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 (tp, convert, offset) - struct tm *tp; - struct tm *(*convert) __P ((const time_t *, struct tm *)); - time_t *offset; +__mktime_internal (struct tm *tp, + struct tm *(*convert) (const time_t *, struct tm *), + mktime_offset_t *offset) { - time_t t, dt, t0; + long_int t, gt, t0, t1, t2, dt; 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, - and leap seconds. Posix.1 prohibits leap seconds, but some hosts - have them anyway. */ - int remaining_probes = 4; + 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. */ @@ -202,98 +343,143 @@ __mktime_internal (tp, convert, offset) int year_requested = tp->tm_year; int isdst = tp->tm_isdst; + /* 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; - int year = year_requested + mon_years; + 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. */ + the remaining code handles overflows correctly. */ /* Calculate day of year from year, month, and day of month. The result need not be in range. */ - int yday = ((__mon_yday[__isleap (year + TM_YEAR_BASE)] - [mon_remainder + 12 * negative_mon_remainder]) - + mday - 1); + int mon_yday = ((__mon_yday[leapyear (year)] + [mon_remainder + 12 * negative_mon_remainder]) + - 1); + long_int lmday = mday; + long_int yday = mon_yday + lmday; -#if LEAP_SECONDS_POSSIBLE - /* Handle out-of-range seconds specially, - since ydhms_tm_diff assumes every minute has 60 seconds. */ - int sec_requested = sec; - if (sec < 0) - sec = 0; - if (59 < sec) - sec = 59; -#endif + int negative_offset_guess; - /* Invert CONVERT by probing. First assume the same offset as last time. - Then repeatedly use the error to improve the guess. */ + int sec_requested = sec; - tm.tm_year = EPOCH_YEAR - TM_YEAR_BASE; - tm.tm_yday = tm.tm_hour = tm.tm_min = tm.tm_sec = 0; - t0 = ydhms_tm_diff (year, yday, hour, min, sec, &tm); + if (LEAP_SECONDS_POSSIBLE) + { + /* Handle out-of-range seconds specially, + since ydhms_tm_diff assumes every minute has 60 seconds. */ + if (sec < 0) + sec = 0; + if (59 < sec) + sec = 59; + } - for (t = t0 + *offset; - (dt = ydhms_tm_diff (year, yday, hour, min, sec, (*convert) (&t, &tm))); - t += dt) - if (--remaining_probes == 0) + /* Invert CONVERT by probing. First assume the same offset as last + time. */ + + INT_SUBTRACT_WRAPV (0, *offset, &negative_offset_guess); + t0 = ydhms_diff (year, yday, hour, min, sec, + EPOCH_YEAR - TM_YEAR_BASE, 0, 0, 0, negative_offset_guess); + + /* 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); + 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)))) + /* 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. */ + goto offset_found; + else if (--remaining_probes == 0) return -1; - /* Check whether tm.tm_isdst has the requested value, if any. */ - if (0 <= isdst && 0 <= tm.tm_isdst) + /* We have a match. Check whether tm.tm_isdst has the requested + value, if any. */ + if (isdst_differ (isdst, tm.tm_isdst)) { - int dst_diff = (isdst != 0) - (tm.tm_isdst != 0); - if (dst_diff) - { - /* Move two hours in the direction indicated by the disagreement, - probe some more, and switch to a new time if found. - The largest known fallback due to daylight savings is two hours: - once, in Newfoundland, 1988-10-30 02:00 -> 00:00. */ - time_t ot = t - 2 * 60 * 60 * dst_diff; - while (--remaining_probes != 0) - { - struct tm otm; - if (! (dt = ydhms_tm_diff (year, yday, hour, min, sec, - (*convert) (&ot, &otm)))) - { - t = ot; - tm = otm; - break; - } - if ((ot += dt) == t) - break; /* Avoid a redundant probe. */ - } - } + /* tm.tm_isdst has the wrong value. Look for a neighboring + 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. */ + + /* 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. */ + 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. */ + 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. */ + 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) + { + long_int ot; + if (! INT_ADD_WRAPV (t, delta * direction, &ot)) + { + 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 = t - t0; + offset_found: + /* Set *OFFSET to the low-order bits of T - T0 - NEGATIVE_OFFSET_GUESS. + This is just a heuristic to speed up the next mktime call, and + correctness is unaffected if integer overflow occurs here. */ + INT_SUBTRACT_WRAPV (t, t0, &dt); + INT_SUBTRACT_WRAPV (dt, negative_offset_guess, offset); -#if LEAP_SECONDS_POSSIBLE - if (sec_requested != tm.tm_sec) + 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. */ - t += sec_requested - sec + (sec == 0 && tm.tm_sec == 60); - (*convert) (&t, &tm); - } -#endif - - if (TIME_T_MAX / INT_MAX / 366 / 24 / 60 / 60 < 3) - { - /* time_t isn't large enough to rule out overflows in ydhms_tm_diff, - so check for major overflows. A gross check suffices, - since if t 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. */ - - double dyear = (double) year_requested + mon_years - tm.tm_year; - double dday = 366 * dyear + mday; - double dsec = 60 * (60 * (24 * dday + hour) + min) + sec_requested; - - if (TIME_T_MAX / 3 - TIME_T_MIN / 3 < (dsec < 0 ? - dsec : dsec)) + long_int sec_adjustment = sec == 0 && tm.tm_sec == 60; + sec_adjustment -= sec; + sec_adjustment += sec_requested; + if (INT_ADD_WRAPV (t, sec_adjustment, &t) + || ! (mktime_min <= t && t <= mktime_max) + || ! convert_time (convert, t, &tm)) return -1; } @@ -301,16 +487,78 @@ __mktime_internal (tp, convert, offset) return t; } +#endif /* NEED_MKTIME_WORKING || NEED_MKTIME_INTERNAL || DEBUG_MKTIME */ + +#if NEED_MKTIME_WORKING || NEED_MKTIME_WINDOWS || DEBUG_MKTIME + +# if NEED_MKTIME_WORKING || DEBUG_MKTIME +static mktime_offset_t localtime_offset; +# endif + +/* Convert *TP to a time_t value. */ +time_t +mktime (struct tm *tp) +{ +# if NEED_MKTIME_WINDOWS + /* Rectify the value of the environment variable TZ. + There are four possible kinds of such values: + - Traditional US time zone names, e.g. "PST8PDT". Syntax: see + <https://msdn.microsoft.com/en-us/library/90s5c885.aspx> + - Time zone names based on geography, that contain one or more + slashes, e.g. "Europe/Moscow". + - Time zone names based on geography, without slashes, e.g. + "Singapore". + - Time zone names that contain explicit DST rules. Syntax: see + <http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#tag_08_03> + The Microsoft CRT understands only the first kind. It produces incorrect + results if the value of TZ is of the other kinds. + But in a Cygwin environment, /etc/profile.d/tzset.sh sets TZ to a value + of the second kind for most geographies, or of the first kind in a few + other geographies. If it is of the second kind, neutralize it. For the + Microsoft CRT, an absent or empty TZ means the time zone that the user + has set in the Windows Control Panel. + If the value of TZ is of the third or fourth kind -- Cygwin programs + understand these syntaxes as well --, it does not matter whether we + neutralize it or not, since these values occur only when a Cygwin user + has set TZ explicitly; this case is 1. rare and 2. under the user's + responsibility. */ + const char *tz = getenv ("TZ"); + if (tz != NULL && strchr (tz, '/') != NULL) + _putenv ("TZ="); +# endif + +# if NEED_MKTIME_WORKING || DEBUG_MKTIME +# 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 (); +# elif HAVE_TZSET + tzset (); +# endif + + return __mktime_internal (tp, __localtime_r, &localtime_offset); +# else +# undef mktime + return mktime (tp); +# endif +} + +#endif /* NEED_MKTIME_WORKING || NEED_MKTIME_WINDOWS || DEBUG_MKTIME */ + #ifdef weak_alias weak_alias (mktime, timelocal) #endif + +#ifdef _LIBC +libc_hidden_def (mktime) +libc_hidden_weak (timelocal) +#endif -#if DEBUG +#if DEBUG_MKTIME static int -not_equal_tm (a, b) - struct tm *a; - struct tm *b; +not_equal_tm (const struct tm *a, const struct tm *b) { return ((a->tm_sec ^ b->tm_sec) | (a->tm_min ^ b->tm_min) @@ -318,35 +566,32 @@ not_equal_tm (a, b) | (a->tm_mday ^ b->tm_mday) | (a->tm_mon ^ b->tm_mon) | (a->tm_year ^ b->tm_year) - | (a->tm_mday ^ b->tm_mday) | (a->tm_yday ^ b->tm_yday) - | (a->tm_isdst ^ b->tm_isdst)); + | isdst_differ (a->tm_isdst, b->tm_isdst)); } static void -print_tm (tp) - struct tm *tp; +print_tm (const struct tm *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); + 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); + else + printf ("0"); } static int -check_result (tk, tmk, tl, tml) - time_t tk; - struct tm tmk; - time_t tl; - struct tm tml; +check_result (time_t tk, struct tm tmk, time_t tl, const struct tm *lt) { - if (tk != tl || not_equal_tm (&tmk, &tml)) + if (tk != tl || !lt || not_equal_tm (&tmk, lt)) { printf ("mktime ("); - print_tm (&tmk); + print_tm (lt); printf (")\nyields ("); - print_tm (&tml); - printf (") == %ld, should be %ld\n", (long) tl, (long) tk); + print_tm (&tmk); + printf (") == %ld, should be %ld\n", (long int) tk, (long int) tl); return 1; } @@ -354,15 +599,22 @@ check_result (tk, tmk, tl, tml) } int -main (argc, argv) - int argc; - char **argv; +main (int argc, char **argv) { int status = 0; struct tm tm, tmk, tml; - time_t tk, tl; + struct tm *lt; + time_t tk, tl, tl1; char trailer; + /* Sanity check, plus call tzset. */ + tl = 0; + if (! localtime (&tl)) + { + printf ("localtime (0) fails\n"); + status = 1; + } + if ((argc == 3 || argc == 4) && (sscanf (argv[1], "%d-%d-%d%c", &tm.tm_year, &tm.tm_mon, &tm.tm_mday, &trailer) @@ -376,11 +628,11 @@ main (argc, argv) tm.tm_isdst = argc == 3 ? -1 : atoi (argv[3]); tmk = tm; tl = mktime (&tmk); - tml = *localtime (&tl); - printf ("mktime returns %ld == ", (long) tl); + lt = localtime_r (&tl, &tml); + printf ("mktime returns %ld == ", (long int) tl); print_tm (&tmk); printf ("\n"); - status = check_result (tl, tmk, tl, tml); + status = check_result (tl, tmk, tl, lt); } else if (argc == 4 || (argc == 5 && strcmp (argv[4], "-") == 0)) { @@ -389,21 +641,43 @@ main (argc, argv) time_t to = atol (argv[3]); if (argc == 4) - for (tl = from; tl <= to; tl += by) + for (tl = from; by < 0 ? to <= tl : tl <= to; tl = tl1) { - tml = *localtime (&tl); - tmk = tml; - tk = mktime (&tmk); - status |= check_result (tk, tmk, tl, tml); + lt = localtime_r (&tl, &tml); + if (lt) + { + tmk = tml; + tk = mktime (&tmk); + status |= check_result (tk, tmk, tl, &tml); + } + else + { + printf ("localtime_r (%ld) yields 0\n", (long int) tl); + status = 1; + } + tl1 = tl + by; + if ((tl1 < tl) != (by < 0)) + break; } else - for (tl = from; tl <= to; tl += by) + for (tl = from; by < 0 ? to <= tl : tl <= to; tl = tl1) { /* Null benchmark. */ - tml = *localtime (&tl); - tmk = tml; - tk = tl; - status |= check_result (tk, tmk, tl, tml); + lt = localtime_r (&tl, &tml); + if (lt) + { + tmk = tml; + tk = tl; + status |= check_result (tk, tmk, tl, &tml); + } + else + { + printf ("localtime_r (%ld) yields 0\n", (long int) tl); + status = 1; + } + tl1 = tl + by; + if ((tl1 < tl) != (by < 0)) + break; } } else @@ -416,10 +690,10 @@ main (argc, argv) return status; } -#endif /* DEBUG */ +#endif /* DEBUG_MKTIME */ /* Local Variables: -compile-command: "gcc -DDEBUG=1 -Wall -O -g mktime.c -o mktime" +compile-command: "gcc -DDEBUG_MKTIME -I. -Wall -W -O2 -g mktime.c -o mktime" End: */ |