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[Emacs-diffs] master 7382f64: Update from glibc and Gnulib
|
From: |
Paul Eggert |
|
Subject: |
[Emacs-diffs] master 7382f64: Update from glibc and Gnulib |
|
Date: |
Fri, 16 Nov 2018 11:25:33 -0500 (EST) |
branch: master
commit 7382f64bd074de59b30c88dd4056186645085a2e
Author: Paul Eggert <address@hidden>
Commit: Paul Eggert <address@hidden>
Update from glibc and Gnulib
This incorporates:
2018-11-15 mktime: DEBUG_MKTIME cleanup
2018-11-15 mktime: fix non-EOVERFLOW errno handling
2018-11-15 mktime: fix bug with Y2038 DST transition
2018-11-15 mktime: make more room for overflow
2018-11-15 mktime: simplify offset guess
2018-11-15 mktime: new test for mktime failure
2018-11-15 mktime: fix EOVERFLOW bug
2018-11-13 longlong: fix comment typo
* lib/gnulib.mk.in: Regenerate.
* lib/mktime.c, m4/longlong.m4: Copy from Gnulib.
---
lib/gnulib.mk.in | 1 -
lib/mktime.c | 391 ++++++++++++++++++-------------------------------------
m4/longlong.m4 | 2 +-
3 files changed, 126 insertions(+), 268 deletions(-)
diff --git a/lib/gnulib.mk.in b/lib/gnulib.mk.in
index c87a15e..eca073d 100644
--- a/lib/gnulib.mk.in
+++ b/lib/gnulib.mk.in
@@ -1051,7 +1051,6 @@ gl_GNULIB_ENABLED_a9786850e999ae65a836a6041e8e5ed1 =
@gl_GNULIB_ENABLED_a9786850
gl_GNULIB_ENABLED_be453cec5eecf5731a274f2de7f2db36 =
@gl_GNULIB_ENABLED_be453cec5eecf5731a274f2de7f2db36@
gl_GNULIB_ENABLED_cloexec = @gl_GNULIB_ENABLED_cloexec@
gl_GNULIB_ENABLED_dirfd = @gl_GNULIB_ENABLED_dirfd@
-gl_GNULIB_ENABLED_dosname = @gl_GNULIB_ENABLED_dosname@
gl_GNULIB_ENABLED_euidaccess = @gl_GNULIB_ENABLED_euidaccess@
gl_GNULIB_ENABLED_getdtablesize = @gl_GNULIB_ENABLED_getdtablesize@
gl_GNULIB_ENABLED_getgroups = @gl_GNULIB_ENABLED_getgroups@
diff --git a/lib/mktime.c b/lib/mktime.c
index 557712f..9c3fb20 100644
--- a/lib/mktime.c
+++ b/lib/mktime.c
@@ -17,12 +17,6 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
-/* Define this to 1 to have a standalone program to test this implementation of
- mktime. */
-#ifndef DEBUG_MKTIME
-# define DEBUG_MKTIME 0
-#endif
-
/* The following macros influence what gets defined when this file is compiled:
Macro/expression Which gnulib module This compilation unit
@@ -34,12 +28,10 @@
|| 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>
+#ifndef _LIBC
+# include <libc-config.h>
#endif
/* Assume that leap seconds are possible, unless told otherwise.
@@ -51,6 +43,7 @@
#include <time.h>
+#include <errno.h>
#include <limits.h>
#include <stdbool.h>
#include <stdlib.h>
@@ -59,13 +52,6 @@
#include <intprops.h>
#include <verify.h>
-#if DEBUG_MKTIME
-# include <stdio.h>
-/* Make it work even if the system's libc has its own mktime routine. */
-# undef mktime
-# define mktime my_mktime
-#endif /* DEBUG_MKTIME */
-
#ifndef NEED_MKTIME_INTERNAL
# define NEED_MKTIME_INTERNAL 0
#endif
@@ -73,7 +59,7 @@
# define NEED_MKTIME_WINDOWS 0
#endif
#ifndef NEED_MKTIME_WORKING
-# define NEED_MKTIME_WORKING DEBUG_MKTIME
+# define NEED_MKTIME_WORKING 0
#endif
#include "mktime-internal.h"
@@ -119,11 +105,12 @@ my_tzset (void)
#if defined _LIBC || NEED_MKTIME_WORKING || NEED_MKTIME_INTERNAL
/* A signed type that can represent an integer number of years
- multiplied by three times the number of seconds in a year. It is
+ multiplied by four 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
+ in a year. The factor of four comes because these products need
to be subtracted from each other, and sometimes with an offset
- added to them, without worrying about overflow.
+ added to them, and then with another timestamp added, 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
@@ -131,12 +118,12 @@ my_tzset (void)
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
+#if INT_MAX <= LONG_MAX / 4 / 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);
+verify (INT_MAX <= TYPE_MAXIMUM (long_int) / 4 / 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
@@ -210,9 +197,10 @@ isdst_differ (int a, int b)
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. */
+ need not be in the usual range. However, YEAR1 - YEAR0 must not
+ overflow even when multiplied by three times the number of seconds
+ in a year, and likewise for YDAY1 - YDAY0 and three times the
+ number of seconds in a day. */
static long_int
ydhms_diff (long_int year1, long_int yday1, int hour1, int min1, int sec1,
@@ -247,43 +235,25 @@ 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.
+/* Return a long_int value corresponding to (YEAR-YDAY HOUR:MIN:SEC)
+ minus *TP seconds, assuming no clock adjustments occurred between
+ the two timestamps.
+
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. */
+ *TP should be in the usual range. */
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)
+tm_diff (long_int year, long_int yday, int hour, int min, int sec,
+ struct tm const *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;
- }
-
- /* 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));
+ return ydhms_diff (year, yday, hour, min, sec,
+ tp->tm_year, tp->tm_yday,
+ tp->tm_hour, tp->tm_min, tp->tm_sec);
}
/* 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. */
+ range for time_t. Return TM if successful, NULL (setting errno) on
+ failure. */
static struct tm *
convert_time (struct tm *(*convert) (const time_t *, struct tm *),
long_int t, struct tm *tm)
@@ -295,47 +265,48 @@ convert_time (struct tm *(*convert) (const time_t *,
struct 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. */
+ A value is in range if it fits in both time_t and long_int.
+ Return TP on success, NULL (setting errno) on failure. */
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 t1 = (*t < mktime_min ? mktime_min
+ : *t <= mktime_max ? *t : mktime_max);
+ struct tm *r = convert_time (convert, t1, tp);
+ if (r)
{
- long_int bad = *t;
- long_int ok = 0;
+ *t = t1;
+ return r;
+ }
+ if (errno != EOVERFLOW)
+ return NULL;
- /* 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;
- }
+ long_int bad = t1;
+ long_int ok = 0;
+ struct tm oktm; oktm.tm_sec = -1;
- if (!r && ok)
- {
- /* The last conversion attempt failed;
- revert to the most recent successful attempt. */
- r = convert_time (convert, ok, tp);
- }
+ /* BAD is a known out-of-range value, and OK is a known in-range 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;
+ if (convert_time (convert, mid, tp))
+ ok = mid, oktm = *tp;
+ else if (errno != EOVERFLOW)
+ return NULL;
+ else
+ bad = mid;
}
- return r;
+ if (oktm.tm_sec < 0)
+ return NULL;
+ *t = ok;
+ *tp = oktm;
+ return tp;
}
@@ -344,13 +315,14 @@ ranged_convert (struct tm *(*convert) (const time_t *,
struct tm *),
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 successful, set *TP to the canonicalized struct tm;
+ otherwise leave *TP alone, return ((time_t) -1) and set errno.
This function is external because it is used also by timegm.c. */
time_t
__mktime_internal (struct tm *tp,
struct tm *(*convert) (const time_t *, struct tm *),
mktime_offset_t *offset)
{
- long_int t, gt, t0, t1, t2, dt;
struct tm tm;
/* The maximum number of probes (calls to CONVERT) should be enough
@@ -370,7 +342,7 @@ __mktime_internal (struct tm *tp,
int isdst = tp->tm_isdst;
/* 1 if the previous probe was DST. */
- int dst2;
+ int dst2 = 0;
/* Ensure that mon is in range, and set year accordingly. */
int mon_remainder = mon % 12;
@@ -398,7 +370,7 @@ __mktime_internal (struct tm *tp,
if (LEAP_SECONDS_POSSIBLE)
{
/* Handle out-of-range seconds specially,
- since ydhms_tm_diff assumes every minute has 60 seconds. */
+ since ydhms_diff assumes every minute has 60 seconds. */
if (sec < 0)
sec = 0;
if (59 < sec)
@@ -409,33 +381,46 @@ __mktime_internal (struct tm *tp,
time. */
INT_SUBTRACT_WRAPV (0, off, &negative_offset_guess);
- t0 = ydhms_diff (year, yday, hour, min, sec,
- EPOCH_YEAR - TM_YEAR_BASE, 0, 0, 0, negative_offset_guess);
+ long_int t0 = ydhms_diff (year, yday, hour, min, sec,
+ EPOCH_YEAR - TM_YEAR_BASE, 0, 0, 0,
+ negative_offset_guess);
+ long_int t = t0, t1 = t0, t2 = 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);
- 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;
+ while (true)
+ {
+ if (! ranged_convert (convert, &t, &tm))
+ return -1;
+ long_int dt = tm_diff (year, yday, hour, min, sec, &tm);
+ if (dt == 0)
+ break;
+
+ 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 DT. Follow the common
+ practice in this case, which is to return a time that is DT
+ 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;
+
+ remaining_probes--;
+ if (remaining_probes == 0)
+ {
+ __set_errno (EOVERFLOW);
+ return -1;
+ }
+
+ t1 = t2, t2 = t, t += dt, dst2 = tm.tm_isdst != 0;
+ }
/* We have a match. Check whether tm.tm_isdst has the requested
value, if any. */
@@ -477,25 +462,38 @@ __mktime_internal (struct tm *tp,
if (! INT_ADD_WRAPV (t, delta * direction, &ot))
{
struct tm otm;
- ranged_convert (convert, &ot, &otm);
+ if (! ranged_convert (convert, &ot, &otm))
+ return -1;
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;
+ long_int gt = ot + tm_diff (year, yday, hour, min, sec,
+ &otm);
+ if (mktime_min <= gt && gt <= mktime_max)
+ {
+ if (convert_time (convert, gt, &tm))
+ {
+ t = gt;
+ goto offset_found;
+ }
+ if (errno != EOVERFLOW)
+ return -1;
+ }
}
}
}
+
+ __set_errno (EOVERFLOW);
+ return -1;
}
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);
+ INT_SUBTRACT_WRAPV (t, t0, offset);
+ INT_SUBTRACT_WRAPV (*offset, negative_offset_guess, offset);
if (LEAP_SECONDS_POSSIBLE && sec_requested != tm.tm_sec)
{
@@ -505,8 +503,12 @@ __mktime_internal (struct tm *tp,
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))
+ || ! (mktime_min <= t && t <= mktime_max))
+ {
+ __set_errno (EOVERFLOW);
+ return -1;
+ }
+ if (! convert_time (convert, t, &tm))
return -1;
}
@@ -545,146 +547,3 @@ weak_alias (mktime, timelocal)
libc_hidden_def (mktime)
libc_hidden_weak (timelocal)
#endif
-
-#if DEBUG_MKTIME
-
-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)
- | isdst_differ (a->tm_isdst, b->tm_isdst));
-}
-
-static void
-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);
- else
- printf ("0");
-}
-
-static int
-check_result (time_t tk, struct tm tmk, time_t tl, const struct tm *lt)
-{
- if (tk != tl || !lt || not_equal_tm (&tmk, lt))
- {
- printf ("mktime (");
- print_tm (lt);
- printf (")\nyields (");
- print_tm (&tmk);
- printf (") == %ld, should be %ld\n", (long int) tk, (long int) tl);
- return 1;
- }
-
- return 0;
-}
-
-int
-main (int argc, char **argv)
-{
- int status = 0;
- struct tm tm, tmk, tml;
- struct tm *lt;
- time_t tk, tl, tl1;
- char trailer;
-
- /* 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)
- == 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);
- lt = localtime_r (&tl, &tml);
- printf ("mktime returns %ld == ", (long int) tl);
- print_tm (&tmk);
- printf ("\n");
- status = check_result (tl, tmk, tl, lt);
- }
- else if (argc == 4 || (argc == 5 && strcmp (argv[4], "-") == 0))
- {
- time_t from = atol (argv[1]);
- time_t by = atol (argv[2]);
- time_t to = atol (argv[3]);
-
- if (argc == 4)
- for (tl = from; by < 0 ? to <= tl : tl <= to; tl = tl1)
- {
- 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; by < 0 ? to <= tl : tl <= to; tl = tl1)
- {
- /* Null benchmark. */
- 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
- 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_MKTIME */
-
-/*
-Local Variables:
-compile-command: "gcc -DDEBUG_MKTIME -I. -Wall -W -O2 -g mktime.c -o mktime"
-End:
-*/
diff --git a/m4/longlong.m4 b/m4/longlong.m4
index 322d79b..582af53 100644
--- a/m4/longlong.m4
+++ b/m4/longlong.m4
@@ -57,7 +57,7 @@ AC_DEFUN([AC_TYPE_LONG_LONG_INT],
])
# Define HAVE_UNSIGNED_LONG_LONG_INT if 'unsigned long long int' works.
-# This fixes can be faster than what's in Autoconf 2.62 through 2.68.
+# This can be faster than what's in Autoconf 2.62 through 2.68.
# Note: If the type 'unsigned long long int' exists but is only 32 bits
# large (as on some very old compilers), AC_TYPE_UNSIGNED_LONG_LONG_INT
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Paul Eggert <=