aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--ChangeLog37
-rw-r--r--manual/maint.texi2
-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.in16
-rw-r--r--sysdeps/unix/sysv/linux/readv.c1
-rw-r--r--sysdeps/unix/sysv/linux/writev.c1
-rw-r--r--time/mktime.c741
-rw-r--r--time/offtime.c10
-rw-r--r--time/time.h5
-rw-r--r--time/timegm.c3
-rw-r--r--time/tzset.c9
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;
}