diff options
| -rw-r--r-- | ChangeLog | 37 | ||||
| -rw-r--r-- | manual/maint.texi | 2 | ||||
| -rw-r--r-- | sysdeps/unix/bsd/readv.S (renamed from sysdeps/unix/common/readv.S) | 0 | ||||
| -rw-r--r-- | sysdeps/unix/bsd/writev.S (renamed from sysdeps/unix/common/writev.S) | 0 | ||||
| -rw-r--r-- | sysdeps/unix/configure.in | 16 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/readv.c | 1 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/writev.c | 1 | ||||
| -rw-r--r-- | time/mktime.c | 741 | ||||
| -rw-r--r-- | time/offtime.c | 10 | ||||
| -rw-r--r-- | time/time.h | 5 | ||||
| -rw-r--r-- | time/timegm.c | 3 | ||||
| -rw-r--r-- | time/tzset.c | 9 |
12 files changed, 373 insertions, 452 deletions
diff --git a/ChangeLog b/ChangeLog index 3909695617..d600df2beb 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,40 @@ +Fri Sep 29 03:43:51 1995 Paul Eggert <eggert@twinsun.com> + + Rewrite mktime from scratch for performance, and for correctness + in the presence of leap seconds. + + * time/mktime.c (ydhms_tm_diff, not_equal_tm, print_tm, check_result): + New functions. + (LEAP_SECONDS_POSSIBLE, CHAR_BIT, INT_MIN, INT_MAX, + TIME_T_MIN, TIME_T_MAX, TM_YEAR_BASE, EPOCH_YEAR): New macros. + <limits.h>, <stdlib.h>: New #includes. + (main): Support tests with given broken-down value; support benchmarks. + (__mon_lengths, debugging_enabled, printtm, dist_tm, doit, + do_normalization, normalize, BAD_STRUCT_TM, SKIP_VALUE, + <ctype.h>): Remove. + + * time/time.h, time/mktime.c (__mktime_internal): New offset arg. + * time/mktime.c (mktime), time/timegm.c (timegm): Use it. + + * time/mktime.c (__mon_yday): New variable; replaces `__mon_lengths'. + time/offtime.c (__offtime), time/tzset.c (compute_change): Use it. + + * time/offtime.c (__offtime): Remove useless assignment + `tp->tm_isdst = -1'. + + * manual/maint.texi: Update credits. + +Fri Oct 6 00:28:53 1995 Roland McGrath <roland@churchy.gnu.ai.mit.edu> + + * sysdeps/unix/common/readv.S: Moved to sysdeps/unix/bsd. + * sysdeps/unix/common/writev.S: Moved to sysdeps/unix/bsd. + * sysdeps/unix/sysv/linux/readv.c: File removed. + * sysdeps/unix/sysv/linux/writev.c: File removed. + * sysdeps/unix/configure.in: Check for readv and writev syscalls. + + * sysdeps/unix/configure.in: If eval doesn't set $unix_srcname, + set it to $unix_syscall instead of $unix_function. + Thu Oct 5 00:59:58 1995 Roland McGrath <roland@churchy.gnu.ai.mit.edu> * elf/rtld.c (dl_main): Grok --list flag. diff --git a/manual/maint.texi b/manual/maint.texi index 49fb6b4a04..c3e3ee24d7 100644 --- a/manual/maint.texi +++ b/manual/maint.texi @@ -774,7 +774,7 @@ The startup code to support SunOS shared libraries was contributed by Tom Quinn. @item -The @code{mktime} function was contributed by Noel Cragg. +The @code{mktime} function was contributed by Paul Eggert. @item The port to the Sequent Symmetry running Dynix version 3 diff --git a/sysdeps/unix/common/readv.S b/sysdeps/unix/bsd/readv.S index 1d643ac6d3..1d643ac6d3 100644 --- a/sysdeps/unix/common/readv.S +++ b/sysdeps/unix/bsd/readv.S diff --git a/sysdeps/unix/common/writev.S b/sysdeps/unix/bsd/writev.S index 3d1692c8fe..3d1692c8fe 100644 --- a/sysdeps/unix/common/writev.S +++ b/sysdeps/unix/bsd/writev.S diff --git a/sysdeps/unix/configure.in b/sysdeps/unix/configure.in index 6d8a1fd006..74456fe18c 100644 --- a/sysdeps/unix/configure.in +++ b/sysdeps/unix/configure.in @@ -72,7 +72,7 @@ for unix_function in \ getitimer setitimer \ getdomainname/getdomain=bsd/bsd4.4 \ setdomainname/setdomain=bsd/bsd4.4 \ - profil=bsd \ + profil=bsd readv=bsd writev=bsd \ getpriority setpriority \ getrlimit setrlimit do @@ -85,7 +85,7 @@ do eval "unix_syscall=`echo $unix_function | \ sed -e 's@=\(.*\)$@ unix_srcdir=\1@' \ -e 's@/\(.*\)$@ unix_srcname=\1@'`" - test -z "$unix_srcname" && unix_srcname=$unix_function + test -z "$unix_srcname" && unix_srcname=$unix_syscall unix_implementor=none for unix_dir in $sysnames; do @@ -97,11 +97,13 @@ do fi done - # mkdir and rmdir have implementations in unix/sysv, but - # the simple syscall versions are preferable if available. - test $unix_syscall = mkdir -o $unix_syscall = rmdir && \ - test $unix_implementor = unix/sysv && \ - unix_implementor=generic + case $unix_syscall in + mkdir|rmdir) + # mkdir and rmdir have implementations in unix/sysv, but + # the simple syscall versions are preferable if available. + test $unix_implementor = unix/sysv && unix_implementor=generic + ;; + esac case $unix_implementor in none|stub|generic|posix) diff --git a/sysdeps/unix/sysv/linux/readv.c b/sysdeps/unix/sysv/linux/readv.c deleted file mode 100644 index baa976da6d..0000000000 --- a/sysdeps/unix/sysv/linux/readv.c +++ /dev/null @@ -1 +0,0 @@ -#include <sysdeps/posix/readv.c> diff --git a/sysdeps/unix/sysv/linux/writev.c b/sysdeps/unix/sysv/linux/writev.c deleted file mode 100644 index 0dc6a76014..0000000000 --- a/sysdeps/unix/sysv/linux/writev.c +++ /dev/null @@ -1 +0,0 @@ -#include <sysdeps/posix/writev.c> diff --git a/time/mktime.c b/time/mktime.c index 1adb138e0a..852d4058b9 100644 --- a/time/mktime.c +++ b/time/mktime.c @@ -1,7 +1,5 @@ /* Copyright (C) 1993, 1994, 1995 Free Software Foundation, Inc. - Contributed by Noel Cragg (noel@cs.oberlin.edu), with fixes by - Michael E. Calwas (calwas@ttd.teradyne.com) and - Wade Hampton (tasi029@tmn.com). + Contributed by Paul Eggert (eggert@twinsun.com). This file is part of the GNU C Library. @@ -22,22 +20,34 @@ Cambridge, MA 02139, USA. */ /* Define this to have a standalone program to test this implementation of mktime. */ -/* #define DEBUG */ +/* #define DEBUG 1 */ #ifdef HAVE_CONFIG_H #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 <sys/types.h> /* Some systems define `time_t' here. */ #include <time.h> +#if __STDC__ || __GNU_LIBRARY__ || STDC_HEADERS +#include <limits.h> +#endif -#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)) +#if DEBUG +#include <stdio.h> +#if __STDC__ || __GNU_LIBRARY__ || STDC_HEADERS +#include <stdlib.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__) @@ -47,370 +57,62 @@ Cambridge, MA 02139, USA. */ #endif /* GCC. */ #endif /* Not __P. */ -/* How many days are in each month. */ -const unsigned short int __mon_lengths[2][12] = - { - /* Normal years. */ - { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, - /* Leap years. */ - { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } - }; - - -static int times_through_search; /* This library routine should never - hang -- make sure we always return - when we're searching for a value */ - - -#ifdef DEBUG - -#include <stdio.h> -#include <ctype.h> - -int debugging_enabled = 0; - -/* Print the values in a `struct tm'. */ -static void -printtm (it) - struct tm *it; -{ - printf ("%02d/%02d/%04d %02d:%02d:%02d (%s) yday:%03d dst:%d gmtoffset:%ld", - it->tm_mon + 1, - it->tm_mday, - it->tm_year + 1900, - it->tm_hour, - it->tm_min, - it->tm_sec, - it->tm_zone, - it->tm_yday, - it->tm_isdst, - it->tm_gmtoff); -} +#ifndef CHAR_BIT +#define CHAR_BIT 8 #endif - -static time_t -dist_tm (t1, t2) - struct tm *t1; - struct tm *t2; -{ - time_t distance = 0; - unsigned long int v1, v2; - int diff_flag = 0; - - v1 = v2 = 0; - -#define doit(x, secs) \ - v1 += t1->x * secs; \ - v2 += t2->x * secs; \ - if (!diff_flag) \ - { \ - if (t1->x < t2->x) \ - diff_flag = -1; \ - else if (t1->x > t2->x) \ - diff_flag = 1; \ - } - - doit (tm_year, 31536000); /* Okay, not all years have 365 days. */ - doit (tm_mon, 2592000); /* Okay, not all months have 30 days. */ - doit (tm_mday, 86400); - doit (tm_hour, 3600); - doit (tm_min, 60); - doit (tm_sec, 1); - -#undef doit - - /* We should also make sure that the sign of DISTANCE is correct -- if - DIFF_FLAG is positive, the distance should be positive and vice versa. */ - - distance = (v1 > v2) ? (v1 - v2) : (v2 - v1); - if (diff_flag < 0) - distance = -distance; - - if (times_through_search > 20) /* Arbitrary # of calls, but makes sure we - never hang if there's a problem with - this algorithm. */ - { - distance = diff_flag; - } - - /* We need this DIFF_FLAG business because it is forseeable that the - distance may be zero when, in actuality, the two structures are - different. This is usually the case when the dates are 366 days apart - and one of the years is a leap year. */ - - if (distance == 0 && diff_flag) - distance = 86400 * diff_flag; - - return distance; -} - - -/* MKTIME converts the values in a struct tm to a time_t. The values - in tm_wday and tm_yday are ignored; other values can be put outside - of legal ranges since they will be normalized. This routine takes - care of that normalization. */ - -void -do_normalization (tmptr) - struct tm *tmptr; -{ - -#define normalize(foo,x,y,bar); \ - while (tmptr->foo < x) \ - { \ - tmptr->bar--; \ - tmptr->foo = (y - (x - tmptr->foo) + 1); \ - } \ - while (tmptr->foo > y) \ - { \ - tmptr->foo = (x + (tmptr->foo - y) - 1); \ - tmptr->bar++; \ - } - - normalize (tm_sec, 0, 59, tm_min); - normalize (tm_min, 0, 59, tm_hour); - normalize (tm_hour, 0, 23, tm_mday); - - /* Do the month first, so day range can be found. */ - normalize (tm_mon, 0, 11, tm_year); - - /* Since the day range modifies the month, we should be careful how - we reference the array of month lengths -- it is possible that - the month will go negative, hence the modulo... - - Also, tm_year is the year - 1900, so we have to 1900 to have it - work correctly. */ - - normalize (tm_mday, 1, - __mon_lengths[__isleap (tmptr->tm_year + 1900)] - [((tmptr->tm_mon < 0) - ? (12 + (tmptr->tm_mon % 12)) - : (tmptr->tm_mon % 12)) ], - tm_mon); - - /* Do the month again, because the day may have pushed it out of range. */ - normalize (tm_mon, 0, 11, tm_year); - - /* Do the day again, because the month may have changed the range. */ - normalize (tm_mday, 1, - __mon_lengths[__isleap (tmptr->tm_year + 1900)] - [((tmptr->tm_mon < 0) - ? (12 + (tmptr->tm_mon % 12)) - : (tmptr->tm_mon % 12)) ], - tm_mon); - -#ifdef DEBUG - if (debugging_enabled) - { - printf (" After normalizing:\n "); - printtm (tmptr); - putchar ('\n'); - } +#ifndef INT_MIN +#define INT_MIN (~0 << (sizeof (int) * CHAR_BIT - 1)) #endif - -} - - -/* Here's where the work gets done. */ - -#define BAD_STRUCT_TM ((time_t) -1) - -time_t -__mktime_internal (timeptr, producer) - struct tm *timeptr; - struct tm *(*producer) __P ((const time_t *, struct tm *)); -{ - struct tm our_tm; /* our working space */ - struct tm *me = &our_tm; /* a pointer to the above */ - time_t result; /* the value we return */ - - *me = *timeptr; /* copy the struct tm that was passed - in by the caller */ - - - /***************************/ - /* Normalize the structure */ - /***************************/ - - /* This routine assumes that the value of TM_ISDST is -1, 0, or 1. - If the user didn't pass it in that way, fix it. */ - - if (me->tm_isdst > 0) - me->tm_isdst = 1; - else if (me->tm_isdst < 0) - me->tm_isdst = -1; - - do_normalization (me); - - /* Get out of here if it's not possible to represent this struct. - If any of the values in the normalized struct tm are negative, - our algorithms won't work. Luckily, we only need to check the - year at this point; normalization guarantees that all values will - be in correct ranges EXCEPT the year. */ - - if (me->tm_year < 0) - return BAD_STRUCT_TM; - - /*************************************************/ - /* Find the appropriate time_t for the structure */ - /*************************************************/ - - /* Modified b-search -- make intelligent guesses as to where the - time might lie along the timeline, assuming that our target time - lies a linear distance (w/o considering time jumps of a - particular region). - - Assume that time does not fluctuate at all along the timeline -- - e.g., assume that a day will always take 86400 seconds, etc. -- - and come up with a hypothetical value for the time_t - representation of the struct tm TARGET, in relation to the guess - variable -- it should be pretty close! - - After testing this, the maximum number of iterations that I had - on any number that I tried was 3! Not bad. - - The reason this is not a subroutine is that we will modify some - fields in the struct tm (yday and mday). I've never felt good - about side-effects when writing structured code... */ - - { - struct tm *guess_tm; - struct tm guess_struct; - time_t guess = 0; - time_t distance = 0; - time_t last_distance = 0; - - times_through_search = 0; - - do - { - guess += distance; - - times_through_search++; - - guess_tm = (*producer) (&guess, &guess_struct); - -#ifdef DEBUG - if (debugging_enabled) - { - printf (" Guessing time_t == %d\n ", (int) guess); - printtm (guess_tm); - putchar ('\n'); - } -#endif - - /* How far is our guess from the desired struct tm? */ - distance = dist_tm (me, guess_tm); - - /* Handle periods of time where a period of time is skipped. - For example, 2:15 3 April 1994 does not exist, because DST - is in effect. The distance function will alternately - return values of 3600 and -3600, because it doesn't know - that the requested time doesn't exist. In these situations - (even if the skip is not exactly an hour) the distances - returned will be the same, but alternating in sign. We - want the later time, so check to see that the distance is - oscillating and we've chosen the correct of the two - possibilities. - - Useful: 3 Apr 94 765356300, 30 Oct 94 783496000 */ - - if ((distance == -last_distance) && (distance < last_distance)) - { - /* If the caller specified that the DST flag was off, it's - not possible to represent this time. */ - if (me->tm_isdst == 0) - { -#ifdef DEBUG - printf (" Distance is oscillating -- dst flag nixes struct!\n"); +#ifndef INT_MAX +#define INT_MAX (~0 - INT_MIN) #endif - return BAD_STRUCT_TM; - } -#ifdef DEBUG - printf (" Distance is oscillating -- chose the later time.\n"); +#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 - distance = 0; - } - - if ((distance == 0) && (me->tm_isdst != -1) - && (me->tm_isdst != guess_tm->tm_isdst)) - { - /* If we're in this code, we've got the right time but the - wrong daylight savings flag. We need to move away from - the time that we have and approach the other time from - the other direction. That is, if I've requested the - non-DST version of a time and I get the DST version - instead, I want to put us forward in time and search - backwards to get the other time. I checked all of the - configuration files for the tz package -- no entry - saves more than two hours, so I think we'll be safe by - moving 24 hours in one direction. IF THE AMOUNT OF - TIME SAVED IN THE CONFIGURATION FILES CHANGES, THIS - VALUE MAY NEED TO BE ADJUSTED. Luckily, we can never - have more than one level of overlaps, or this would - never work. */ - -#define SKIP_VALUE 86400 - - if (guess_tm->tm_isdst == 0) - /* we got the later one, but want the earlier one */ - distance = -SKIP_VALUE; - else - distance = SKIP_VALUE; - -#ifdef DEBUG - printf (" Got the right time, wrong DST value -- adjusting\n"); +#ifndef TIME_T_MAX +#define TIME_T_MAX (~ (time_t) 0 - TIME_T_MIN) #endif - } - - last_distance = distance; - - } while (distance != 0); - /* Check to see that the dst flag matches */ +#define TM_YEAR_BASE 1900 +#define EPOCH_YEAR 1970 - if (me->tm_isdst != -1) - { - if (me->tm_isdst != guess_tm->tm_isdst) - { -#ifdef DEBUG - printf (" DST flag doesn't match! FIXME?\n"); +#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 - return BAD_STRUCT_TM; - } - } - - result = guess; /* Success! */ - - /* On successful completion, the values of tm_wday and tm_yday - have to be set appropriately. */ - - /* me->tm_yday = guess_tm->tm_yday; - me->tm_mday = guess_tm->tm_mday; */ - - *me = *guess_tm; - } - /* Update the caller's version of the structure */ +/* How many days come before each month (0-12). */ +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 } + }; - *timeptr = *me; +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 *)); - return result; -} #if ! HAVE_LOCALTIME_R && ! defined (localtime_r) #ifdef _LIBC #define localtime_r __localtime_r #else /* Approximate localtime_r as best we can in its absence. */ -#define localtime_r my_localtime_r /* Avoid clash with system localtime_r. */ +#define localtime_r my_localtime_r +static struct tm *localtime_r __P ((const time_t *, struct tm *)); static struct tm * localtime_r (t, tp) const time_t *t; struct tm *tp; -{ +{ struct tm *l = localtime (t); if (! l) return 0; @@ -420,108 +122,287 @@ localtime_r (t, tp) #endif /* ! _LIBC */ #endif /* ! HAVE_LOCALTIME_R && ! defined (localtime_r) */ + +/* 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; +{ + time_t ay = year + (time_t) (TM_YEAR_BASE - 1); + time_t by = tp->tm_year + (time_t) (TM_YEAR_BASE - 1); + time_t intervening_leap_days = + (ay/4 - by/4) - (ay/100 - by/100) + (ay/400 - by/400); + time_t years = ay - by; + 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)); +} + + +/* Convert *TP to a time_t value. */ time_t -#ifdef DEBUG /* make it work even if the system's - libc has it's own mktime routine */ -my_mktime (timeptr) -#else -mktime (timeptr) -#endif - struct tm *timeptr; +mktime (tp) + struct tm *tp; { - return __mktime_internal (timeptr, localtime_r); + static time_t localtime_offset; + return __mktime_internal (tp, localtime_r, &localtime_offset); } -#ifdef weak_alias -weak_alias (mktime, timelocal) -#endif - -#ifdef DEBUG -void -main (argc, argv) - int argc; - char *argv[]; +/* 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. */ +time_t +__mktime_internal (tp, convert, offset) + struct tm *tp; + struct tm *(*convert) __P ((const time_t *, struct tm *)); + time_t *offset; { - int time; - int result_time; - struct tm *tmptr; - - if (argc == 1) - { - long q; - - printf ("starting long test...\n"); + time_t t, dt, t0; + 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; + + /* 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; + int isdst = tp->tm_isdst; + + /* 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; + + /* 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 yday = ((__mon_yday[__isleap (year + TM_YEAR_BASE)] + [mon_remainder + 12 * negative_mon_remainder]) + + mday - 1); + +#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 + + /* Invert CONVERT by probing. First assume the same offset as last time. + Then repeatedly use the error to improve the guess. */ + + 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); - for (q = 10000000; q < 1000000000; q += 599) + for (t = t0 + *offset; + (dt = ydhms_tm_diff (year, yday, hour, min, sec, (*convert) (&t, &tm))); + t += dt) + if (--remaining_probes == 0) + return -1; + + /* Check whether tm.tm_isdst has the requested value, if any. */ + if (0 <= isdst && 0 <= tm.tm_isdst) + { + int dst_diff = (isdst != 0) - (tm.tm_isdst != 0); + if (dst_diff) { - struct tm *tm = localtime ((time_t *) &q); - if ((q % 10000) == 0) { printf ("%ld\n", q); fflush (stdout); } - if (q != my_mktime (tm)) - { printf ("failed for %ld\n", q); fflush (stdout); } + /* 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. */ + } } - - printf ("test finished\n"); + } - exit (0); + *offset = t - t0; + +#if LEAP_SECONDS_POSSIBLE + if (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); } - - if (argc != 2) +#endif + + if (TIME_T_MAX / INT_MAX / 366 / 24 / 60 / 60 < 3) { - printf ("wrong # of args\n"); - exit (0); + /* 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)) + return -1; } - - debugging_enabled = 1; /* We want to see the info */ - - ++argv; - time = atoi (*argv); - - tmptr = localtime ((time_t *) &time); - printf ("Localtime tells us that a time_t of %d represents\n ", time); - printtm (tmptr); - putchar ('\n'); - - printf (" Given localtime's return val, mktime returns %d which is\n ", - (int) my_mktime (tmptr)); - printtm (tmptr); - putchar ('\n'); - -#if 0 - tmptr->tm_sec -= 20; - tmptr->tm_min -= 20; - tmptr->tm_hour -= 20; - tmptr->tm_mday -= 20; - tmptr->tm_mon -= 20; - tmptr->tm_year -= 20; - tmptr->tm_gmtoff -= 20000; /* This has no effect! */ - tmptr->tm_zone = NULL; /* Nor does this! */ - tmptr->tm_isdst = -1; + + *tp = tm; + return t; +} + +#ifdef weak_alias +weak_alias (mktime, timelocal) #endif - - tmptr->tm_hour += 1; - tmptr->tm_isdst = -1; + +#if DEBUG - printf ("\n\nchanged ranges: "); - printtm (tmptr); - putchar ('\n'); +static int +not_equal_tm (a, b) + struct tm *a; + 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_mday ^ b->tm_mday) + | (a->tm_yday ^ b->tm_yday) + | (a->tm_isdst ^ b->tm_isdst)); +} - result_time = my_mktime (tmptr); - printf ("\nmktime: %d\n", result_time); +static void +print_tm (tp) + 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); +} - tmptr->tm_isdst = 0; +static int +check_result (tk, tmk, tl, tml) + time_t tk; + struct tm tmk; + time_t tl; + struct tm tml; +{ + if (tk != tl || not_equal_tm (&tmk, &tml)) + { + printf ("mktime ("); + print_tm (&tmk); + printf (")\nyields ("); + print_tm (&tml); + printf (") == %ld, should be %ld\n", (long) tl, (long) tk); + return 1; + } + + return 0; +} - printf ("\n\nchanged ranges: "); - printtm (tmptr); - putchar ('\n'); +int +main (argc, argv) + int argc; + char **argv; +{ + int status = 0; + struct tm tm, tmk, tml; + time_t tk, tl; + char trailer; + + if ((argc == 3 || argc == 4) + && (sscanf (argv[1], "%d-%d-%d%c", + &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_year -= TM_YEAR_BASE; + tm.tm_mon--; + tm.tm_isdst = argc == 3 ? -1 : atoi (argv[3]); + tmk = tm; + tl = mktime (&tmk); + tml = *localtime (&tl); + printf ("mktime returns %ld == ", (long) tl); + print_tm (&tmk); + printf ("\n"); + status = check_result (tl, tmk, tl, tml); + } + 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]); - result_time = my_mktime (tmptr); - printf ("\nmktime: %d\n", result_time); + if (argc == 4) + for (tl = from; tl <= to; tl += by) + { + tml = *localtime (&tl); + tmk = tml; + tk = mktime (&tmk); + status |= check_result (tk, tmk, tl, tml); + } + else + for (tl = from; tl <= to; tl += by) + { + /* Null benchmark. */ + tml = *localtime (&tl); + tmk = tml; + tk = tl; + status |= check_result (tk, tmk, tl, tml); + } + } + 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]); + + return status; } -#endif /* DEBUG */ +#endif /* DEBUG */ /* Local Variables: -compile-command: "gcc -g mktime.c -o mktime -DDEBUG" +compile-command: "gcc -DDEBUG=1 -Wall -O -g mktime.c -o mktime" End: */ diff --git a/time/offtime.c b/time/offtime.c index e588c4c66b..4b8ddb170b 100644 --- a/time/offtime.c +++ b/time/offtime.c @@ -21,7 +21,7 @@ Cambridge, MA 02139, USA. */ /* Defined in mktime.c. */ -extern CONST unsigned short int __mon_lengths[2][12]; +extern CONST unsigned short int __mon_yday[2][13]; #define SECS_PER_HOUR (60 * 60) #define SECS_PER_DAY (SECS_PER_HOUR * 24) @@ -71,10 +71,10 @@ DEFUN(__offtime, (t, offset, tp), } tp->tm_year = y - 1900; tp->tm_yday = days; - ip = __mon_lengths[__isleap(y)]; - for (y = 0; days >= ip[y]; ++y) - days -= ip[y]; + ip = __mon_yday[__isleap(y)]; + for (y = 11; days < ip[y]; --y) + continue; + days -= ip[y]; tp->tm_mon = y; tp->tm_mday = days + 1; - tp->tm_isdst = -1; } diff --git a/time/time.h b/time/time.h index 6d52e943eb..7d90b7a617 100644 --- a/time/time.h +++ b/time/time.h @@ -110,10 +110,11 @@ extern time_t mktime __P ((struct tm *__tp)); /* Subroutine of `mktime'. Return the `time_t' representation of TP and normalize TP, given that a `struct tm *' maps to a `time_t' as performed - by FUNC. */ + by FUNC. Keep track of next guess for time_t offset in *OFFSET. */ extern time_t __mktime_internal __P ((struct tm *__tp, struct tm *(*__func) (const time_t *, - struct tm *))); + struct tm *), + time_t *__offset)); /* Format TP into S according to FORMAT. diff --git a/time/timegm.c b/time/timegm.c index f63aac94ca..4dd87f46d2 100644 --- a/time/timegm.c +++ b/time/timegm.c @@ -22,6 +22,7 @@ time_t timegm (tmp) struct tm *const tmp; { + static time_t gmtime_offset; tmp->tm_isdst = 0; - return __mktime_internal (tmp, __gmtime_r); + return __mktime_internal (tmp, __gmtime_r, &gmtime_offset); } diff --git a/time/tzset.c b/time/tzset.c index ccaffd9c4a..813609c230 100644 --- a/time/tzset.c +++ b/time/tzset.c @@ -25,7 +25,7 @@ Cambridge, MA 02139, USA. */ #include <time.h> /* Defined in mktime.c. */ -extern CONST unsigned short int __mon_lengths[2][12]; +extern CONST unsigned short int __mon_yday[2][13]; #define NOID #include "tzfile.h" @@ -403,10 +403,11 @@ DEFUN(compute_change, (rule, year), tz_rule *rule AND int year) /* Mm.n.d - Nth "Dth day" of month M. */ { register int i, d, m1, yy0, yy1, yy2, dow; + register CONST unsigned short int *myday = + &__mon_yday[__isleap (year)][rule->m]; /* First add SECSPERDAY for each day in months before M. */ - for (i = 0; i < rule->m - 1; ++i) - t += __mon_lengths[__isleap (year)][i] * SECSPERDAY; + t += myday[-1] * SECSPERDAY; /* Use Zeller's Congruence to get day-of-week of first day of month. */ m1 = (rule->m + 9) % 12 + 1; @@ -424,7 +425,7 @@ DEFUN(compute_change, (rule, year), tz_rule *rule AND int year) d += 7; for (i = 1; i < rule->n; ++i) { - if (d + 7 >= __mon_lengths[__isleap (year)][rule->m - 1]) + if (d + 7 >= myday[0] - myday[-1]) break; d += 7; } |