Adding upstream version 9.4.upstream/9.4upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 579 insertions, 0 deletions

diff --git a/lib/mktime.c b/lib/mktime.c
new file mode 100644
index 0000000..8e80bcd
--- /dev/null
+++ b/lib/mktime.c
@@ -0,0 +1,579 @@
+/* Convert a 'struct tm' to a time_t value.
+   Copyright (C) 1993-2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   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 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
+   Lesser General Public License for more details.
+
+   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/>.  */
+
+/* The following macros influence what gets defined when this file is compiled:
+
+   Macro/expression            Which gnulib module    This compilation unit
+                                                      should define
+
+   _LIBC                       (glibc proper)         mktime
+
+   NEED_MKTIME_WORKING         mktime                 rpl_mktime
+   || NEED_MKTIME_WINDOWS
+
+   NEED_MKTIME_INTERNAL        mktime-internal        mktime_internal
+ */
+
+#ifndef _LIBC
+# include <libc-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 <time.h>
+
+#include <errno.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdckdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <intprops.h>
+#include <verify.h>
+
+#ifndef NEED_MKTIME_INTERNAL
+# define NEED_MKTIME_INTERNAL 0
+#endif
+#ifndef NEED_MKTIME_WINDOWS
+# define NEED_MKTIME_WINDOWS 0
+#endif
+#ifndef NEED_MKTIME_WORKING
+# define NEED_MKTIME_WORKING 0
+#endif
+
+#include "mktime-internal.h"
+
+#if !defined _LIBC && (NEED_MKTIME_WORKING || NEED_MKTIME_WINDOWS)
+static void
+my_tzset (void)
+{
+# 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://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/tzset>
+       - 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
+         <https://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=");
+# else
+  tzset ();
+# endif
+}
+# undef __tzset
+# define __tzset() my_tzset ()
+#endif
+
+#if defined _LIBC || NEED_MKTIME_WORKING || NEED_MKTIME_INTERNAL
+
+/* A signed type that can represent an integer number of years
+   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 four comes because these products need
+   to be subtracted from each other, and sometimes with an offset
+   added to them, and then with another timestamp added, without
+   worrying about overflow.
+
+   Much of the code uses long_int to represent __time64_t values, to
+   lessen the hassle of dealing with platforms where __time64_t is
+   unsigned, and because long_int should suffice to represent all
+   __time64_t values that mktime can generate even on platforms where
+   __time64_t is wider than the int components of struct tm.  */
+
+#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) / 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
+   <= 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 + (a < 0)) / (one << b) - (a < 0));
+}
+
+/* Bounds for the intersection of __time64_t and long_int.  */
+
+static long_int const mktime_min
+  = ((TYPE_SIGNED (__time64_t)
+      && TYPE_MINIMUM (__time64_t) < TYPE_MINIMUM (long_int))
+     ? TYPE_MINIMUM (long_int) : TYPE_MINIMUM (__time64_t));
+static long_int const mktime_max
+  = (TYPE_MAXIMUM (long_int) < TYPE_MAXIMUM (__time64_t)
+     ? TYPE_MAXIMUM (long_int) : TYPE_MAXIMUM (__time64_t));
+
+#define EPOCH_YEAR 1970
+#define TM_YEAR_BASE 1900
+verify (TM_YEAR_BASE % 100 == 0);
+
+/* 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.  */
+    { 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 }
+  };
+
+
+/* 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)
+{
+  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 - 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,
+	    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 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 + (a4 < 0)) / 25 - (a4 < 0);
+  int b100 = (b4 + (b4 < 0)) / 25 - (b4 < 0);
+  int a400 = shr (a100, 2);
+  int b400 = shr (b100, 2);
+  int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400);
+
+  /* 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 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.
+   *TP should be in the usual range.  */
+static long_int
+tm_diff (long_int year, long_int yday, int hour, int min, int sec,
+	 struct tm const *tp)
+{
+  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 __time64_t.  Return TM if successful, NULL (setting errno) on
+   failure.  */
+static struct tm *
+convert_time (struct tm *(*convert) (const __time64_t *, struct tm *),
+	      long_int t, struct tm *tm)
+{
+  __time64_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 __time64_t and long_int.
+   Return TP on success, NULL (setting errno) on failure.  */
+static struct tm *
+ranged_convert (struct tm *(*convert) (const __time64_t *, struct tm *),
+		long_int *t, struct tm *tp)
+{
+  long_int t1 = (*t < mktime_min ? mktime_min
+		 : *t <= mktime_max ? *t : mktime_max);
+  struct tm *r = convert_time (convert, t1, tp);
+  if (r)
+    {
+      *t = t1;
+      return r;
+    }
+  if (errno != EOVERFLOW)
+    return NULL;
+
+  long_int bad = t1;
+  long_int ok = 0;
+  struct tm oktm; oktm.tm_sec = -1;
+
+  /* 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;
+    }
+
+  if (oktm.tm_sec < 0)
+    return NULL;
+  *t = ok;
+  *tp = oktm;
+  return tp;
+}
+
+
+/* Convert *TP to a __time64_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 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.  */
+__time64_t
+__mktime_internal (struct tm *tp,
+		   struct tm *(*convert) (const __time64_t *, struct tm *),
+		   mktime_offset_t *offset)
+{
+  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,
+     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.  */
+  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;
+
+  /* 1 if the previous probe was DST.  */
+  int dst2 = 0;
+
+  /* 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;
+  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 overflows correctly.  */
+
+  /* Calculate day of year from year, month, and day of month.
+     The result need not be in range.  */
+  int mon_yday = ((__mon_yday[leapyear (year)]
+		   [mon_remainder + 12 * negative_mon_remainder])
+		  - 1);
+  long_int lmday = mday;
+  long_int yday = mon_yday + lmday;
+
+  mktime_offset_t off = *offset;
+  int negative_offset_guess;
+
+  int sec_requested = sec;
+
+  if (LEAP_SECONDS_POSSIBLE)
+    {
+      /* Handle out-of-range seconds specially,
+	 since ydhms_diff assumes every minute has 60 seconds.  */
+      if (sec < 0)
+	sec = 0;
+      if (59 < sec)
+	sec = 59;
+    }
+
+  /* Invert CONVERT by probing.  First assume the same offset as last
+     time.  */
+
+  ckd_sub (&negative_offset_guess, 0, off);
+  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.  */
+
+  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.  */
+  if (isdst_differ (isdst, tm.tm_isdst))
+    {
+      /* tm.tm_isdst has the wrong value.  Look for a neighboring
+	 time with the right value, and use its UTC offset.
+
+	 Heuristic: probe the adjacent timestamps in both directions,
+	 looking for the desired isdst.  If none is found within a
+	 reasonable duration bound, assume a one-hour DST difference.
+	 This should work for all real time zone histories in the tz
+	 database.  */
+
+      /* +1 if we wanted standard time but got DST, -1 if the reverse.  */
+      int dst_difference = (isdst == 0) - (tm.tm_isdst == 0);
+
+      /* 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;
+
+      /* In TZDB 2021e, the longest period of DST (or of non-DST), in
+	 which the DST (or adjacent DST) difference is not one hour,
+	 is 457243209 seconds: e.g., America/Cambridge_Bay with leap
+	 seconds, starting 1965-10-31 00:00 in a switch from
+	 double-daylight time (-05) to standard time (-07), and
+	 continuing to 1980-04-27 02:00 in a switch from standard time
+	 (-07) to daylight time (-06).  */
+      int duration_max = 457243209;
+
+      /* 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 (! ckd_add (&ot, t, delta * direction))
+	      {
+		struct tm 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.  */
+		    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;
+		      }
+		  }
+	      }
+	  }
+
+      /* No unusual DST offset was found nearby.  Assume one-hour DST.  */
+      t += 60 * 60 * dst_difference;
+      if (mktime_min <= t && t <= mktime_max && convert_time (convert, t, &tm))
+	goto offset_found;
+
+      __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.  */
+  ckd_sub (offset, t, t0);
+  ckd_sub (offset, *offset, negative_offset_guess);
+
+  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.  */
+      long_int sec_adjustment = sec == 0 && tm.tm_sec == 60;
+      sec_adjustment -= sec;
+      sec_adjustment += sec_requested;
+      if (ckd_add (&t, t, sec_adjustment)
+	  || ! (mktime_min <= t && t <= mktime_max))
+	{
+	  __set_errno (EOVERFLOW);
+	  return -1;
+	}
+      if (! convert_time (convert, t, &tm))
+	return -1;
+    }
+
+  *tp = tm;
+  return t;
+}
+
+#endif /* _LIBC || NEED_MKTIME_WORKING || NEED_MKTIME_INTERNAL */
+
+#if defined _LIBC || NEED_MKTIME_WORKING || NEED_MKTIME_WINDOWS
+
+/* Convert *TP to a __time64_t value.  */
+__time64_t
+__mktime64 (struct tm *tp)
+{
+  /* 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 ();
+
+# if defined _LIBC || NEED_MKTIME_WORKING
+  static mktime_offset_t localtime_offset;
+  return __mktime_internal (tp, __localtime64_r, &localtime_offset);
+# else
+#  undef mktime
+  return mktime (tp);
+# endif
+}
+#endif /* _LIBC || NEED_MKTIME_WORKING || NEED_MKTIME_WINDOWS */
+
+#if defined _LIBC && __TIMESIZE != 64
+
+libc_hidden_def (__mktime64)
+
+time_t
+mktime (struct tm *tp)
+{
+  struct tm tm = *tp;
+  __time64_t t = __mktime64 (&tm);
+  if (in_time_t_range (t))
+    {
+      *tp = tm;
+      return t;
+    }
+  else
+    {
+      __set_errno (EOVERFLOW);
+      return -1;
+    }
+}
+
+#endif
+
+weak_alias (mktime, timelocal)
+libc_hidden_def (mktime)
+libc_hidden_weak (timelocal)