~drizzle-trunk/drizzle/development

815.1.1 by Monty Taylor
Add timegm which is missing on Solaris.
1
/* Convert a `struct tm' to a time_t value.
2
   Copyright (C) 1993-1999, 2002-2005, 2006, 2007 Free Software Foundation, Inc.
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   This file is part of the GNU C Library.
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   Contributed by Paul Eggert <eggert@twinsun.com>.
5
6
   This program is free software; you can redistribute it and/or modify
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   it under the terms of the GNU Lesser General Public License as published by
8
   the Free Software Foundation; either version 2, or (at your option)
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   any later version.
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11
   This program is distributed in the hope that it will be useful,
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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   GNU Lesser General Public License for more details.
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16
   You should have received a copy of the GNU Lesser General Public License along
17
   with this program; if not, write to the Free Software Foundation,
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   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
19
20
/* Define this to have a standalone program to test this implementation of
21
   mktime.  */
22
/* #define DEBUG 1 */
23
24
#ifndef _LIBC
25
# include <config.h>
26
#endif
27
28
/* Assume that leap seconds are possible, unless told otherwise.
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   If the host has a `zic' command with a `-L leapsecondfilename' option,
30
   then it supports leap seconds; otherwise it probably doesn't.  */
31
#ifndef LEAP_SECONDS_POSSIBLE
32
# define LEAP_SECONDS_POSSIBLE 1
33
#endif
34
35
#include <time.h>
36
37
#include <limits.h>
38
39
#include <string.h>		/* For the real memcpy prototype.  */
40
994.2.8 by Monty Taylor
Updated gnulib files.
41
#if DEBUG
815.1.1 by Monty Taylor
Add timegm which is missing on Solaris.
42
# include <stdio.h>
43
# include <stdlib.h>
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/* Make it work even if the system's libc has its own mktime routine.  */
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# define mktime my_mktime
46
#endif /* DEBUG */
47
48
/* Shift A right by B bits portably, by dividing A by 2**B and
49
   truncating towards minus infinity.  A and B should be free of side
50
   effects, and B should be in the range 0 <= B <= INT_BITS - 2, where
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   INT_BITS is the number of useful bits in an int.  GNU code can
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   assume that INT_BITS is at least 32.
53
54
   ISO C99 says that A >> B is implementation-defined if A < 0.  Some
55
   implementations (e.g., UNICOS 9.0 on a Cray Y-MP EL) don't shift
56
   right in the usual way when A < 0, so SHR falls back on division if
57
   ordinary A >> B doesn't seem to be the usual signed shift.  */
58
#define SHR(a, b)	\
59
  (-1 >> 1 == -1	\
60
   ? (a) >> (b)		\
61
   : (a) / (1 << (b)) - ((a) % (1 << (b)) < 0))
62
63
/* The extra casts in the following macros work around compiler bugs,
64
   e.g., in Cray C 5.0.3.0.  */
65
66
/* True if the arithmetic type T is an integer type.  bool counts as
67
   an integer.  */
68
#define TYPE_IS_INTEGER(t) ((t) 1.5 == 1)
69
70
/* True if negative values of the signed integer type T use two's
71
   complement, ones' complement, or signed magnitude representation,
72
   respectively.  Much GNU code assumes two's complement, but some
73
   people like to be portable to all possible C hosts.  */
74
#define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1)
75
#define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0)
76
#define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1)
77
78
/* True if the arithmetic type T is signed.  */
79
#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
80
81
/* The maximum and minimum values for the integer type T.  These
82
   macros have undefined behavior if T is signed and has padding bits.
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   If this is a problem for you, please let us know how to fix it for
84
   your host.  */
85
#define TYPE_MINIMUM(t) \
86
  ((t) (! TYPE_SIGNED (t) \
87
	? (t) 0 \
88
	: TYPE_SIGNED_MAGNITUDE (t) \
89
	? ~ (t) 0 \
90
	: ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1)))
91
#define TYPE_MAXIMUM(t) \
92
  ((t) (! TYPE_SIGNED (t) \
93
	? (t) -1 \
94
	: ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))))
95
96
#ifndef TIME_T_MIN
97
# define TIME_T_MIN TYPE_MINIMUM (time_t)
98
#endif
99
#ifndef TIME_T_MAX
100
# define TIME_T_MAX TYPE_MAXIMUM (time_t)
101
#endif
102
#define TIME_T_MIDPOINT (SHR (TIME_T_MIN + TIME_T_MAX, 1) + 1)
103
104
/* Verify a requirement at compile-time (unlike assert, which is runtime).  */
105
#define verify(name, assertion) struct name { char a[(assertion) ? 1 : -1]; }
106
107
verify (time_t_is_integer, TYPE_IS_INTEGER (time_t));
108
verify (twos_complement_arithmetic, TYPE_TWOS_COMPLEMENT (int));
109
/* The code also assumes that signed integer overflow silently wraps
110
   around, but this assumption can't be stated without causing a
111
   diagnostic on some hosts.  */
112
113
#define EPOCH_YEAR 1970
114
#define TM_YEAR_BASE 1900
115
verify (base_year_is_a_multiple_of_100, TM_YEAR_BASE % 100 == 0);
116
117
/* Return 1 if YEAR + TM_YEAR_BASE is a leap year.  */
118
static inline int
119
leapyear (long int year)
120
{
121
  /* Don't add YEAR to TM_YEAR_BASE, as that might overflow.
122
     Also, work even if YEAR is negative.  */
123
  return
124
    ((year & 3) == 0
125
     && (year % 100 != 0
126
	 || ((year / 100) & 3) == (- (TM_YEAR_BASE / 100) & 3)));
127
}
128
129
/* How many days come before each month (0-12).  */
130
#ifndef _LIBC
131
static
132
#endif
133
const unsigned short int __mon_yday[2][13] =
134
  {
135
    /* Normal years.  */
136
    { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
137
    /* Leap years.  */
138
    { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
139
  };
140
141
142
#ifndef _LIBC
143
/* Portable standalone applications should supply a <time.h> that
144
   declares a POSIX-compliant localtime_r, for the benefit of older
145
   implementations that lack localtime_r or have a nonstandard one.
146
   See the gnulib time_r module for one way to implement this.  */
147
# undef __localtime_r
148
# define __localtime_r localtime_r
149
# define __mktime_internal mktime_internal
150
#endif
151
152
/* Return an integer value measuring (YEAR1-YDAY1 HOUR1:MIN1:SEC1) -
153
   (YEAR0-YDAY0 HOUR0:MIN0:SEC0) in seconds, assuming that the clocks
154
   were not adjusted between the time stamps.
155
156
   The YEAR values uses the same numbering as TP->tm_year.  Values
157
   need not be in the usual range.  However, YEAR1 must not be less
158
   than 2 * INT_MIN or greater than 2 * INT_MAX.
159
160
   The result may overflow.  It is the caller's responsibility to
161
   detect overflow.  */
162
163
static inline time_t
164
ydhms_diff (long int year1, long int yday1, int hour1, int min1, int sec1,
165
	    int year0, int yday0, int hour0, int min0, int sec0)
166
{
167
  verify (C99_integer_division, -1 / 2 == 0);
168
  verify (long_int_year_and_yday_are_wide_enough,
169
	  INT_MAX <= LONG_MAX / 2 || TIME_T_MAX <= UINT_MAX);
170
171
  /* Compute intervening leap days correctly even if year is negative.
172
     Take care to avoid integer overflow here.  */
173
  int a4 = SHR (year1, 2) + SHR (TM_YEAR_BASE, 2) - ! (year1 & 3);
174
  int b4 = SHR (year0, 2) + SHR (TM_YEAR_BASE, 2) - ! (year0 & 3);
175
  int a100 = a4 / 25 - (a4 % 25 < 0);
176
  int b100 = b4 / 25 - (b4 % 25 < 0);
177
  int a400 = SHR (a100, 2);
178
  int b400 = SHR (b100, 2);
179
  int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400);
180
181
  /* Compute the desired time in time_t precision.  Overflow might
182
     occur here.  */
183
  time_t tyear1 = year1;
184
  time_t years = tyear1 - year0;
185
  time_t days = 365 * years + yday1 - yday0 + intervening_leap_days;
186
  time_t hours = 24 * days + hour1 - hour0;
187
  time_t minutes = 60 * hours + min1 - min0;
188
  time_t seconds = 60 * minutes + sec1 - sec0;
189
  return seconds;
190
}
191
192
193
/* Return a time_t value corresponding to (YEAR-YDAY HOUR:MIN:SEC),
194
   assuming that *T corresponds to *TP and that no clock adjustments
195
   occurred between *TP and the desired time.
196
   If TP is null, return a value not equal to *T; this avoids false matches.
197
   If overflow occurs, yield the minimal or maximal value, except do not
198
   yield a value equal to *T.  */
199
static time_t
200
guess_time_tm (long int year, long int yday, int hour, int min, int sec,
201
	       const time_t *t, const struct tm *tp)
202
{
203
  if (tp)
204
    {
205
      time_t d = ydhms_diff (year, yday, hour, min, sec,
206
			     tp->tm_year, tp->tm_yday,
207
			     tp->tm_hour, tp->tm_min, tp->tm_sec);
208
      time_t t1 = *t + d;
209
      if ((t1 < *t) == (TYPE_SIGNED (time_t) ? d < 0 : TIME_T_MAX / 2 < d))
210
	return t1;
211
    }
212
213
  /* Overflow occurred one way or another.  Return the nearest result
214
     that is actually in range, except don't report a zero difference
215
     if the actual difference is nonzero, as that would cause a false
216
     match; and don't oscillate between two values, as that would
217
     confuse the spring-forward gap detector.  */
218
  return (*t < TIME_T_MIDPOINT
219
	  ? (*t <= TIME_T_MIN + 1 ? *t + 1 : TIME_T_MIN)
220
	  : (TIME_T_MAX - 1 <= *t ? *t - 1 : TIME_T_MAX));
221
}
222
223
/* Use CONVERT to convert *T to a broken down time in *TP.
224
   If *T is out of range for conversion, adjust it so that
225
   it is the nearest in-range value and then convert that.  */
226
static struct tm *
227
ranged_convert (struct tm *(*convert) (const time_t *, struct tm *),
228
		time_t *t, struct tm *tp)
229
{
230
  struct tm *r = convert (t, tp);
231
232
  if (!r && *t)
233
    {
234
      time_t bad = *t;
235
      time_t ok = 0;
236
237
      /* BAD is a known unconvertible time_t, and OK is a known good one.
238
	 Use binary search to narrow the range between BAD and OK until
239
	 they differ by 1.  */
240
      while (bad != ok + (bad < 0 ? -1 : 1))
241
	{
242
	  time_t mid = *t = (bad < 0
243
			     ? bad + ((ok - bad) >> 1)
244
			     : ok + ((bad - ok) >> 1));
245
	  r = convert (t, tp);
246
	  if (r)
247
	    ok = mid;
248
	  else
249
	    bad = mid;
250
	}
251
252
      if (!r && ok)
253
	{
254
	  /* The last conversion attempt failed;
255
	     revert to the most recent successful attempt.  */
256
	  *t = ok;
257
	  r = convert (t, tp);
258
	}
259
    }
260
261
  return r;
262
}
263
264
265
/* Convert *TP to a time_t value, inverting
266
   the monotonic and mostly-unit-linear conversion function CONVERT.
267
   Use *OFFSET to keep track of a guess at the offset of the result,
268
   compared to what the result would be for UTC without leap seconds.
269
   If *OFFSET's guess is correct, only one CONVERT call is needed.
270
   This function is external because it is used also by timegm.c.  */
271
time_t
272
__mktime_internal (struct tm *tp,
273
		   struct tm *(*convert) (const time_t *, struct tm *),
274
		   time_t *offset)
275
{
276
  time_t t, gt, t0, t1, t2;
277
  struct tm tm;
278
279
  /* The maximum number of probes (calls to CONVERT) should be enough
280
     to handle any combinations of time zone rule changes, solar time,
281
     leap seconds, and oscillations around a spring-forward gap.
282
     POSIX.1 prohibits leap seconds, but some hosts have them anyway.  */
283
  int remaining_probes = 6;
284
285
  /* Time requested.  Copy it in case CONVERT modifies *TP; this can
286
     occur if TP is localtime's returned value and CONVERT is localtime.  */
287
  int sec = tp->tm_sec;
288
  int min = tp->tm_min;
289
  int hour = tp->tm_hour;
290
  int mday = tp->tm_mday;
291
  int mon = tp->tm_mon;
292
  int year_requested = tp->tm_year;
994.2.8 by Monty Taylor
Updated gnulib files.
293
  /* Normalize the value.  */
294
  int isdst = ((tp->tm_isdst >> (8 * sizeof (tp->tm_isdst) - 1))
295
	       | (tp->tm_isdst != 0));
815.1.1 by Monty Taylor
Add timegm which is missing on Solaris.
296
297
  /* 1 if the previous probe was DST.  */
298
  int dst2;
299
300
  /* Ensure that mon is in range, and set year accordingly.  */
301
  int mon_remainder = mon % 12;
302
  int negative_mon_remainder = mon_remainder < 0;
303
  int mon_years = mon / 12 - negative_mon_remainder;
304
  long int lyear_requested = year_requested;
305
  long int year = lyear_requested + mon_years;
306
307
  /* The other values need not be in range:
308
     the remaining code handles minor overflows correctly,
309
     assuming int and time_t arithmetic wraps around.
310
     Major overflows are caught at the end.  */
311
312
  /* Calculate day of year from year, month, and day of month.
313
     The result need not be in range.  */
314
  int mon_yday = ((__mon_yday[leapyear (year)]
315
		   [mon_remainder + 12 * negative_mon_remainder])
316
		  - 1);
317
  long int lmday = mday;
318
  long int yday = mon_yday + lmday;
319
320
  time_t guessed_offset = *offset;
321
322
  int sec_requested = sec;
323
324
  if (LEAP_SECONDS_POSSIBLE)
325
    {
326
      /* Handle out-of-range seconds specially,
327
	 since ydhms_tm_diff assumes every minute has 60 seconds.  */
328
      if (sec < 0)
329
	sec = 0;
330
      if (59 < sec)
331
	sec = 59;
332
    }
333
334
  /* Invert CONVERT by probing.  First assume the same offset as last
335
     time.  */
336
337
  t0 = ydhms_diff (year, yday, hour, min, sec,
338
		   EPOCH_YEAR - TM_YEAR_BASE, 0, 0, 0, - guessed_offset);
339
340
  if (TIME_T_MAX / INT_MAX / 366 / 24 / 60 / 60 < 3)
341
    {
342
      /* time_t isn't large enough to rule out overflows, so check
343
	 for major overflows.  A gross check suffices, since if t0
344
	 has overflowed, it is off by a multiple of TIME_T_MAX -
345
	 TIME_T_MIN + 1.  So ignore any component of the difference
346
	 that is bounded by a small value.  */
347
348
      /* Approximate log base 2 of the number of time units per
349
	 biennium.  A biennium is 2 years; use this unit instead of
350
	 years to avoid integer overflow.  For example, 2 average
351
	 Gregorian years are 2 * 365.2425 * 24 * 60 * 60 seconds,
352
	 which is 63113904 seconds, and rint (log2 (63113904)) is
353
	 26.  */
354
      int ALOG2_SECONDS_PER_BIENNIUM = 26;
355
      int ALOG2_MINUTES_PER_BIENNIUM = 20;
356
      int ALOG2_HOURS_PER_BIENNIUM = 14;
357
      int ALOG2_DAYS_PER_BIENNIUM = 10;
358
      int LOG2_YEARS_PER_BIENNIUM = 1;
359
360
      int approx_requested_biennia =
361
	(SHR (year_requested, LOG2_YEARS_PER_BIENNIUM)
362
	 - SHR (EPOCH_YEAR - TM_YEAR_BASE, LOG2_YEARS_PER_BIENNIUM)
363
	 + SHR (mday, ALOG2_DAYS_PER_BIENNIUM)
364
	 + SHR (hour, ALOG2_HOURS_PER_BIENNIUM)
365
	 + SHR (min, ALOG2_MINUTES_PER_BIENNIUM)
366
	 + (LEAP_SECONDS_POSSIBLE
367
	    ? 0
368
	    : SHR (sec, ALOG2_SECONDS_PER_BIENNIUM)));
369
370
      int approx_biennia = SHR (t0, ALOG2_SECONDS_PER_BIENNIUM);
371
      int diff = approx_biennia - approx_requested_biennia;
372
      int abs_diff = diff < 0 ? - diff : diff;
373
374
      /* IRIX 4.0.5 cc miscaculates TIME_T_MIN / 3: it erroneously
375
	 gives a positive value of 715827882.  Setting a variable
376
	 first then doing math on it seems to work.
377
	 (ghazi@caip.rutgers.edu) */
378
      time_t time_t_max = TIME_T_MAX;
379
      time_t time_t_min = TIME_T_MIN;
380
      time_t overflow_threshold =
381
	(time_t_max / 3 - time_t_min / 3) >> ALOG2_SECONDS_PER_BIENNIUM;
382
383
      if (overflow_threshold < abs_diff)
384
	{
385
	  /* Overflow occurred.  Try repairing it; this might work if
386
	     the time zone offset is enough to undo the overflow.  */
387
	  time_t repaired_t0 = -1 - t0;
388
	  approx_biennia = SHR (repaired_t0, ALOG2_SECONDS_PER_BIENNIUM);
389
	  diff = approx_biennia - approx_requested_biennia;
390
	  abs_diff = diff < 0 ? - diff : diff;
391
	  if (overflow_threshold < abs_diff)
392
	    return -1;
393
	  guessed_offset += repaired_t0 - t0;
394
	  t0 = repaired_t0;
395
	}
396
    }
397
398
  /* Repeatedly use the error to improve the guess.  */
399
400
  for (t = t1 = t2 = t0, dst2 = 0;
401
       (gt = guess_time_tm (year, yday, hour, min, sec, &t,
402
			    ranged_convert (convert, &t, &tm)),
403
	t != gt);
404
       t1 = t2, t2 = t, t = gt, dst2 = tm.tm_isdst != 0)
405
    if (t == t1 && t != t2
406
	&& (tm.tm_isdst < 0
407
	    || (isdst < 0
408
		? dst2 <= (tm.tm_isdst != 0)
409
		: (isdst != 0) != (tm.tm_isdst != 0))))
410
      /* We can't possibly find a match, as we are oscillating
411
	 between two values.  The requested time probably falls
412
	 within a spring-forward gap of size GT - T.  Follow the common
413
	 practice in this case, which is to return a time that is GT - T
414
	 away from the requested time, preferring a time whose
415
	 tm_isdst differs from the requested value.  (If no tm_isdst
416
	 was requested and only one of the two values has a nonzero
417
	 tm_isdst, prefer that value.)  In practice, this is more
418
	 useful than returning -1.  */
419
      goto offset_found;
420
    else if (--remaining_probes == 0)
421
      return -1;
422
423
  /* We have a match.  Check whether tm.tm_isdst has the requested
424
     value, if any.  */
425
  if (isdst != tm.tm_isdst && 0 <= isdst && 0 <= tm.tm_isdst)
426
    {
427
      /* tm.tm_isdst has the wrong value.  Look for a neighboring
428
	 time with the right value, and use its UTC offset.
429
430
	 Heuristic: probe the adjacent timestamps in both directions,
431
	 looking for the desired isdst.  This should work for all real
432
	 time zone histories in the tz database.  */
433
434
      /* Distance between probes when looking for a DST boundary.  In
435
	 tzdata2003a, the shortest period of DST is 601200 seconds
436
	 (e.g., America/Recife starting 2000-10-08 01:00), and the
437
	 shortest period of non-DST surrounded by DST is 694800
438
	 seconds (Africa/Tunis starting 1943-04-17 01:00).  Use the
439
	 minimum of these two values, so we don't miss these short
440
	 periods when probing.  */
441
      int stride = 601200;
442
443
      /* The longest period of DST in tzdata2003a is 536454000 seconds
444
	 (e.g., America/Jujuy starting 1946-10-01 01:00).  The longest
445
	 period of non-DST is much longer, but it makes no real sense
446
	 to search for more than a year of non-DST, so use the DST
447
	 max.  */
448
      int duration_max = 536454000;
449
450
      /* Search in both directions, so the maximum distance is half
451
	 the duration; add the stride to avoid off-by-1 problems.  */
452
      int delta_bound = duration_max / 2 + stride;
453
454
      int delta, direction;
455
456
      for (delta = stride; delta < delta_bound; delta += stride)
457
	for (direction = -1; direction <= 1; direction += 2)
458
	  {
459
	    time_t ot = t + delta * direction;
460
	    if ((ot < t) == (direction < 0))
461
	      {
462
		struct tm otm;
463
		ranged_convert (convert, &ot, &otm);
464
		if (otm.tm_isdst == isdst)
465
		  {
466
		    /* We found the desired tm_isdst.
467
		       Extrapolate back to the desired time.  */
468
		    t = guess_time_tm (year, yday, hour, min, sec, &ot, &otm);
469
		    ranged_convert (convert, &t, &tm);
470
		    goto offset_found;
471
		  }
472
	      }
473
	  }
474
    }
475
476
 offset_found:
477
  *offset = guessed_offset + t - t0;
478
479
  if (LEAP_SECONDS_POSSIBLE && sec_requested != tm.tm_sec)
480
    {
481
      /* Adjust time to reflect the tm_sec requested, not the normalized value.
482
	 Also, repair any damage from a false match due to a leap second.  */
483
      int sec_adjustment = (sec == 0 && tm.tm_sec == 60) - sec;
484
      t1 = t + sec_requested;
485
      t2 = t1 + sec_adjustment;
486
      if (((t1 < t) != (sec_requested < 0))
487
	  | ((t2 < t1) != (sec_adjustment < 0))
488
	  | ! convert (&t2, &tm))
489
	return -1;
490
      t = t2;
491
    }
492
493
  *tp = tm;
494
  return t;
495
}
496
497
498
/* FIXME: This should use a signed type wide enough to hold any UTC
499
   offset in seconds.  'int' should be good enough for GNU code.  We
500
   can't fix this unilaterally though, as other modules invoke
501
   __mktime_internal.  */
502
static time_t localtime_offset;
503
504
/* Convert *TP to a time_t value.  */
505
time_t
506
mktime (struct tm *tp)
507
{
508
#ifdef _LIBC
509
  /* POSIX.1 8.1.1 requires that whenever mktime() is called, the
510
     time zone names contained in the external variable `tzname' shall
511
     be set as if the tzset() function had been called.  */
512
  __tzset ();
513
#endif
514
515
  return __mktime_internal (tp, __localtime_r, &localtime_offset);
516
}
517
518
#ifdef weak_alias
519
weak_alias (mktime, timelocal)
520
#endif
521
522
#ifdef _LIBC
523
libc_hidden_def (mktime)
524
libc_hidden_weak (timelocal)
525
#endif
526

994.2.8 by Monty Taylor
Updated gnulib files.
527
#if DEBUG
815.1.1 by Monty Taylor
Add timegm which is missing on Solaris.
528
529
static int
530
not_equal_tm (const struct tm *a, const struct tm *b)
531
{
532
  return ((a->tm_sec ^ b->tm_sec)
533
	  | (a->tm_min ^ b->tm_min)
534
	  | (a->tm_hour ^ b->tm_hour)
535
	  | (a->tm_mday ^ b->tm_mday)
536
	  | (a->tm_mon ^ b->tm_mon)
537
	  | (a->tm_year ^ b->tm_year)
538
	  | (a->tm_yday ^ b->tm_yday)
539
	  | (a->tm_isdst ^ b->tm_isdst));
540
}
541
542
static void
543
print_tm (const struct tm *tp)
544
{
545
  if (tp)
546
    printf ("%04d-%02d-%02d %02d:%02d:%02d yday %03d wday %d isdst %d",
547
	    tp->tm_year + TM_YEAR_BASE, tp->tm_mon + 1, tp->tm_mday,
548
	    tp->tm_hour, tp->tm_min, tp->tm_sec,
549
	    tp->tm_yday, tp->tm_wday, tp->tm_isdst);
550
  else
551
    printf ("0");
552
}
553
554
static int
555
check_result (time_t tk, struct tm tmk, time_t tl, const struct tm *lt)
556
{
557
  if (tk != tl || !lt || not_equal_tm (&tmk, lt))
558
    {
559
      printf ("mktime (");
560
      print_tm (lt);
561
      printf (")\nyields (");
562
      print_tm (&tmk);
563
      printf (") == %ld, should be %ld\n", (long int) tk, (long int) tl);
564
      return 1;
565
    }
566
567
  return 0;
568
}
569
570
int
571
main (int argc, char **argv)
572
{
573
  int status = 0;
574
  struct tm tm, tmk, tml;
575
  struct tm *lt;
576
  time_t tk, tl, tl1;
577
  char trailer;
578
579
  if ((argc == 3 || argc == 4)
580
      && (sscanf (argv[1], "%d-%d-%d%c",
581
		  &tm.tm_year, &tm.tm_mon, &tm.tm_mday, &trailer)
582
	  == 3)
583
      && (sscanf (argv[2], "%d:%d:%d%c",
584
		  &tm.tm_hour, &tm.tm_min, &tm.tm_sec, &trailer)
585
	  == 3))
586
    {
587
      tm.tm_year -= TM_YEAR_BASE;
588
      tm.tm_mon--;
589
      tm.tm_isdst = argc == 3 ? -1 : atoi (argv[3]);
590
      tmk = tm;
591
      tl = mktime (&tmk);
592
      lt = localtime (&tl);
593
      if (lt)
594
	{
595
	  tml = *lt;
596
	  lt = &tml;
597
	}
598
      printf ("mktime returns %ld == ", (long int) tl);
599
      print_tm (&tmk);
600
      printf ("\n");
601
      status = check_result (tl, tmk, tl, lt);
602
    }
603
  else if (argc == 4 || (argc == 5 && strcmp (argv[4], "-") == 0))
604
    {
605
      time_t from = atol (argv[1]);
606
      time_t by = atol (argv[2]);
607
      time_t to = atol (argv[3]);
608
609
      if (argc == 4)
610
	for (tl = from; by < 0 ? to <= tl : tl <= to; tl = tl1)
611
	  {
612
	    lt = localtime (&tl);
613
	    if (lt)
614
	      {
615
		tmk = tml = *lt;
616
		tk = mktime (&tmk);
617
		status |= check_result (tk, tmk, tl, &tml);
618
	      }
619
	    else
620
	      {
621
		printf ("localtime (%ld) yields 0\n", (long int) tl);
622
		status = 1;
623
	      }
624
	    tl1 = tl + by;
625
	    if ((tl1 < tl) != (by < 0))
626
	      break;
627
	  }
628
      else
629
	for (tl = from; by < 0 ? to <= tl : tl <= to; tl = tl1)
630
	  {
631
	    /* Null benchmark.  */
632
	    lt = localtime (&tl);
633
	    if (lt)
634
	      {
635
		tmk = tml = *lt;
636
		tk = tl;
637
		status |= check_result (tk, tmk, tl, &tml);
638
	      }
639
	    else
640
	      {
641
		printf ("localtime (%ld) yields 0\n", (long int) tl);
642
		status = 1;
643
	      }
644
	    tl1 = tl + by;
645
	    if ((tl1 < tl) != (by < 0))
646
	      break;
647
	  }
648
    }
649
  else
650
    printf ("Usage:\
651
\t%s YYYY-MM-DD HH:MM:SS [ISDST] # Test given time.\n\
652
\t%s FROM BY TO # Test values FROM, FROM+BY, ..., TO.\n\
653
\t%s FROM BY TO - # Do not test those values (for benchmark).\n",
654
	    argv[0], argv[0], argv[0]);
655
656
  return status;
657
}
658
659
#endif /* DEBUG */
660

661
/*
662
Local Variables:
663
compile-command: "gcc -DDEBUG -Wall -W -O -g mktime.c -o mktime"
664
End:
665
*/