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-rw-r--r--src/ChangeLog2
-rw-r--r--src/mktime.c544
2 files changed, 2 insertions, 544 deletions
diff --git a/src/ChangeLog b/src/ChangeLog
index 52eb207466c..badd1955c50 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,7 @@
12011-01-09 Paul Eggert <eggert@cs.ucla.edu> 12011-01-09 Paul Eggert <eggert@cs.ucla.edu>
2 2
3 * mktime.c: Remove; moving to ../lib.
4
3 Use gnulib's mktime module. 5 Use gnulib's mktime module.
4 * deps.mk (mktime.o): Remove rule. 6 * deps.mk (mktime.o): Remove rule.
5 7
diff --git a/src/mktime.c b/src/mktime.c
deleted file mode 100644
index ede151981f4..00000000000
--- a/src/mktime.c
+++ /dev/null
@@ -1,544 +0,0 @@
1/* Convert a `struct tm' to a time_t value.
2 Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2001, 2002, 2003,
3 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
4 Contributed by Paul Eggert (eggert@twinsun.com).
5
6 NOTE: The canonical source of this file is maintained with the GNU C Library.
7 Bugs can be reported to bug-glibc@gnu.org.
8
9 This program is free software; you can redistribute it and/or modify it
10 under the terms of the GNU General Public License as published by the
11 Free Software Foundation; either version 2, or (at your option) any
12 later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
22 USA. */
23
24/* Define this to have a standalone program to test this implementation of
25 mktime. */
26/* #define DEBUG 1 */
27
28#ifdef HAVE_CONFIG_H
29# include <config.h>
30#endif
31
32#ifdef _LIBC
33# define HAVE_LIMITS_H 1
34# define STDC_HEADERS 1
35#endif
36
37/* Assume that leap seconds are possible, unless told otherwise.
38 If the host has a `zic' command with a `-L leapsecondfilename' option,
39 then it supports leap seconds; otherwise it probably doesn't. */
40#ifndef LEAP_SECONDS_POSSIBLE
41# define LEAP_SECONDS_POSSIBLE 1
42#endif
43
44#include <sys/types.h> /* Some systems define `time_t' here. */
45#include <time.h>
46
47#if HAVE_LIMITS_H
48# include <limits.h>
49#endif
50
51#if DEBUG
52# include <stdio.h>
53# if STDC_HEADERS
54# include <stdlib.h>
55# endif
56/* Make it work even if the system's libc has its own mktime routine. */
57# define mktime my_mktime
58#endif /* DEBUG */
59
60#ifndef CHAR_BIT
61# define CHAR_BIT 8
62#endif
63
64/* The extra casts work around common compiler bugs. */
65#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
66/* The outer cast is needed to work around a bug in Cray C 5.0.3.0.
67 It is necessary at least when t == time_t. */
68#define TYPE_MINIMUM(t) ((t) (TYPE_SIGNED (t) \
69 ? ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1) : (t) 0))
70#define TYPE_MAXIMUM(t) ((t) (~ (t) 0 - TYPE_MINIMUM (t)))
71
72#ifndef INT_MIN
73# define INT_MIN TYPE_MINIMUM (int)
74#endif
75#ifndef INT_MAX
76# define INT_MAX TYPE_MAXIMUM (int)
77#endif
78
79#ifndef TIME_T_MIN
80# define TIME_T_MIN TYPE_MINIMUM (time_t)
81#endif
82#ifndef TIME_T_MAX
83# define TIME_T_MAX TYPE_MAXIMUM (time_t)
84#endif
85
86#define TM_YEAR_BASE 1900
87#define EPOCH_YEAR 1970
88
89#ifndef __isleap
90/* Nonzero if YEAR is a leap year (every 4 years,
91 except every 100th isn't, and every 400th is). */
92# define __isleap(year) \
93 ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
94#endif
95
96/* How many days come before each month (0-12). */
97const unsigned short int __mon_yday[2][13] =
98 {
99 /* Normal years. */
100 { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
101 /* Leap years. */
102 { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
103 };
104
105
106#ifdef _LIBC
107# define my_mktime_localtime_r __localtime_r
108#else
109/* If we're a mktime substitute in a GNU program, then prefer
110 localtime to localtime_r, since many localtime_r implementations
111 are buggy. */
112static struct tm *
113my_mktime_localtime_r (const time_t *t, struct tm *tp)
114{
115 struct tm *l = localtime (t);
116 if (! l)
117 return 0;
118 *tp = *l;
119 return tp;
120}
121#endif /* ! _LIBC */
122
123
124/* Yield the difference between (YEAR-YDAY HOUR:MIN:SEC) and (*TP),
125 measured in seconds, ignoring leap seconds.
126 YEAR uses the same numbering as TM->tm_year.
127 All values are in range, except possibly YEAR.
128 If TP is null, return a nonzero value.
129 If overflow occurs, yield the low order bits of the correct answer. */
130static time_t
131ydhms_tm_diff (int year, int yday, int hour, int min, int sec, const struct tm *tp)
132{
133 if (!tp)
134 return 1;
135 else
136 {
137 /* Compute intervening leap days correctly even if year is negative.
138 Take care to avoid int overflow. time_t overflow is OK, since
139 only the low order bits of the correct time_t answer are needed.
140 Don't convert to time_t until after all divisions are done, since
141 time_t might be unsigned. */
142 int a4 = (year >> 2) + (TM_YEAR_BASE >> 2) - ! (year & 3);
143 int b4 = (tp->tm_year >> 2) + (TM_YEAR_BASE >> 2) - ! (tp->tm_year & 3);
144 int a100 = a4 / 25 - (a4 % 25 < 0);
145 int b100 = b4 / 25 - (b4 % 25 < 0);
146 int a400 = a100 >> 2;
147 int b400 = b100 >> 2;
148 int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400);
149 time_t years = year - (time_t) tp->tm_year;
150 time_t days = (365 * years + intervening_leap_days
151 + (yday - tp->tm_yday));
152 return (60 * (60 * (24 * days + (hour - tp->tm_hour))
153 + (min - tp->tm_min))
154 + (sec - tp->tm_sec));
155 }
156}
157
158/* Use CONVERT to convert *T to a broken down time in *TP.
159 If *T is out of range for conversion, adjust it so that
160 it is the nearest in-range value and then convert that. */
161static struct tm *
162ranged_convert (struct tm *(*convert) (const time_t *, struct tm *),
163 time_t *t, struct tm *tp)
164{
165 struct tm *r;
166
167 if (! (r = (*convert) (t, tp)) && *t)
168 {
169 time_t bad = *t;
170 time_t ok = 0;
171 struct tm tm;
172
173 /* BAD is a known unconvertible time_t, and OK is a known good one.
174 Use binary search to narrow the range between BAD and OK until
175 they differ by 1. */
176 while (bad != ok + (bad < 0 ? -1 : 1))
177 {
178 time_t mid = *t = (bad < 0
179 ? bad + ((ok - bad) >> 1)
180 : ok + ((bad - ok) >> 1));
181 if ((r = (*convert) (t, tp)))
182 {
183 tm = *r;
184 ok = mid;
185 }
186 else
187 bad = mid;
188 }
189
190 if (!r && ok)
191 {
192 /* The last conversion attempt failed;
193 revert to the most recent successful attempt. */
194 *t = ok;
195 *tp = tm;
196 r = tp;
197 }
198 }
199
200 return r;
201}
202
203
204/* Convert *TP to a time_t value, inverting
205 the monotonic and mostly-unit-linear conversion function CONVERT.
206 Use *OFFSET to keep track of a guess at the offset of the result,
207 compared to what the result would be for UTC without leap seconds.
208 If *OFFSET's guess is correct, only one CONVERT call is needed. */
209time_t
210__mktime_internal (struct tm *tp, struct tm *(*convert) (const time_t *, struct tm *),
211 time_t *offset)
212{
213 time_t t, dt, t0, t1, t2;
214 struct tm tm;
215
216 /* The maximum number of probes (calls to CONVERT) should be enough
217 to handle any combinations of time zone rule changes, solar time,
218 leap seconds, and oscillations around a spring-forward gap.
219 POSIX.1 prohibits leap seconds, but some hosts have them anyway. */
220 int remaining_probes = 6;
221
222 /* Time requested. Copy it in case CONVERT modifies *TP; this can
223 occur if TP is localtime's returned value and CONVERT is localtime. */
224 int sec = tp->tm_sec;
225 int min = tp->tm_min;
226 int hour = tp->tm_hour;
227 int mday = tp->tm_mday;
228 int mon = tp->tm_mon;
229 int year_requested = tp->tm_year;
230 int isdst = tp->tm_isdst;
231
232 /* 1 if the previous probe was DST. */
233 int dst2;
234
235 /* Ensure that mon is in range, and set year accordingly. */
236 int mon_remainder = mon % 12;
237 int negative_mon_remainder = mon_remainder < 0;
238 int mon_years = mon / 12 - negative_mon_remainder;
239 int year = year_requested + mon_years;
240
241 /* The other values need not be in range:
242 the remaining code handles minor overflows correctly,
243 assuming int and time_t arithmetic wraps around.
244 Major overflows are caught at the end. */
245
246 /* Calculate day of year from year, month, and day of month.
247 The result need not be in range. */
248 int yday = ((__mon_yday[__isleap (year + TM_YEAR_BASE)]
249 [mon_remainder + 12 * negative_mon_remainder])
250 + mday - 1);
251
252 int sec_requested = sec;
253
254 /* Only years after 1970 are defined.
255 If year is 69, it might still be representable due to
256 timezone differences. */
257 if (year < 69)
258 return -1;
259
260#if LEAP_SECONDS_POSSIBLE
261 /* Handle out-of-range seconds specially,
262 since ydhms_tm_diff assumes every minute has 60 seconds. */
263 if (sec < 0)
264 sec = 0;
265 if (59 < sec)
266 sec = 59;
267#endif
268
269 /* Invert CONVERT by probing. First assume the same offset as last time.
270 Then repeatedly use the error to improve the guess. */
271
272 tm.tm_year = EPOCH_YEAR - TM_YEAR_BASE;
273 tm.tm_yday = tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
274 t0 = ydhms_tm_diff (year, yday, hour, min, sec, &tm);
275
276 for (t = t1 = t2 = t0 + *offset, dst2 = 0;
277 (dt = ydhms_tm_diff (year, yday, hour, min, sec,
278 ranged_convert (convert, &t, &tm)));
279 t1 = t2, t2 = t, t += dt, dst2 = tm.tm_isdst != 0)
280 if (t == t1 && t != t2
281 && (tm.tm_isdst < 0
282 || (isdst < 0
283 ? dst2 <= (tm.tm_isdst != 0)
284 : (isdst != 0) != (tm.tm_isdst != 0))))
285 /* We can't possibly find a match, as we are oscillating
286 between two values. The requested time probably falls
287 within a spring-forward gap of size DT. Follow the common
288 practice in this case, which is to return a time that is DT
289 away from the requested time, preferring a time whose
290 tm_isdst differs from the requested value. (If no tm_isdst
291 was requested and only one of the two values has a nonzero
292 tm_isdst, prefer that value.) In practice, this is more
293 useful than returning -1. */
294 break;
295 else if (--remaining_probes == 0)
296 return -1;
297
298 /* If we have a match, check whether tm.tm_isdst has the requested
299 value, if any. */
300 if (dt == 0 && isdst != tm.tm_isdst && 0 <= isdst && 0 <= tm.tm_isdst)
301 {
302 /* tm.tm_isdst has the wrong value. Look for a neighboring
303 time with the right value, and use its UTC offset.
304 Heuristic: probe the previous three calendar quarters (approximately),
305 looking for the desired isdst. This isn't perfect,
306 but it's good enough in practice. */
307 int quarter = 7889238; /* seconds per average 1/4 Gregorian year */
308 int i;
309
310 /* If we're too close to the time_t limit, look in future quarters. */
311 if (t < TIME_T_MIN + 3 * quarter)
312 quarter = -quarter;
313
314 for (i = 1; i <= 3; i++)
315 {
316 time_t ot = t - i * quarter;
317 struct tm otm;
318 ranged_convert (convert, &ot, &otm);
319 if (otm.tm_isdst == isdst)
320 {
321 /* We found the desired tm_isdst.
322 Extrapolate back to the desired time. */
323 t = ot + ydhms_tm_diff (year, yday, hour, min, sec, &otm);
324 ranged_convert (convert, &t, &tm);
325 break;
326 }
327 }
328 }
329
330 *offset = t - t0;
331
332#if LEAP_SECONDS_POSSIBLE
333 if (sec_requested != tm.tm_sec)
334 {
335 /* Adjust time to reflect the tm_sec requested, not the normalized value.
336 Also, repair any damage from a false match due to a leap second. */
337 t += sec_requested - sec + (sec == 0 && tm.tm_sec == 60);
338 if (! (*convert) (&t, &tm))
339 return -1;
340 }
341#endif
342
343 if (TIME_T_MAX / INT_MAX / 366 / 24 / 60 / 60 < 3)
344 {
345 /* time_t isn't large enough to rule out overflows in ydhms_tm_diff,
346 so check for major overflows. A gross check suffices,
347 since if t has overflowed, it is off by a multiple of
348 TIME_T_MAX - TIME_T_MIN + 1. So ignore any component of
349 the difference that is bounded by a small value. */
350
351 double dyear = (double) year_requested + mon_years - tm.tm_year;
352 double dday = 366 * dyear + mday;
353 double dsec = 60 * (60 * (24 * dday + hour) + min) + sec_requested;
354
355 /* On Irix4.0.5 cc, dividing TIME_T_MIN by 3 does not produce
356 correct results, ie., it erroneously gives a positive value
357 of 715827882. Setting a variable first then doing math on it
358 seems to work. (ghazi@caip.rutgers.edu) */
359
360 const time_t time_t_max = TIME_T_MAX;
361 const time_t time_t_min = TIME_T_MIN;
362
363 if (time_t_max / 3 - time_t_min / 3 < (dsec < 0 ? - dsec : dsec))
364 return -1;
365 }
366
367 if (year == 69)
368 {
369 /* If year was 69, need to check whether the time was representable
370 or not. */
371 if (t < 0 || t > 2 * 24 * 60 * 60)
372 return -1;
373 }
374
375 *tp = tm;
376 return t;
377}
378
379
380static time_t localtime_offset;
381
382/* Convert *TP to a time_t value. */
383time_t
384mktime (tp)
385 struct tm *tp;
386{
387#ifdef _LIBC
388 /* POSIX.1 8.1.1 requires that whenever mktime() is called, the
389 time zone names contained in the external variable `tzname' shall
390 be set as if the tzset() function had been called. */
391 __tzset ();
392#endif
393
394 return __mktime_internal (tp, my_mktime_localtime_r, &localtime_offset);
395}
396
397#ifdef weak_alias
398weak_alias (mktime, timelocal)
399#endif
400
401#if DEBUG
402
403static int
404not_equal_tm (a, b)
405 struct tm *a;
406 struct tm *b;
407{
408 return ((a->tm_sec ^ b->tm_sec)
409 | (a->tm_min ^ b->tm_min)
410 | (a->tm_hour ^ b->tm_hour)
411 | (a->tm_mday ^ b->tm_mday)
412 | (a->tm_mon ^ b->tm_mon)
413 | (a->tm_year ^ b->tm_year)
414 | (a->tm_mday ^ b->tm_mday)
415 | (a->tm_yday ^ b->tm_yday)
416 | (a->tm_isdst ^ b->tm_isdst));
417}
418
419static void
420print_tm (tp)
421 struct tm *tp;
422{
423 if (tp)
424 printf ("%04d-%02d-%02d %02d:%02d:%02d yday %03d wday %d isdst %d",
425 tp->tm_year + TM_YEAR_BASE, tp->tm_mon + 1, tp->tm_mday,
426 tp->tm_hour, tp->tm_min, tp->tm_sec,
427 tp->tm_yday, tp->tm_wday, tp->tm_isdst);
428 else
429 printf ("0");
430}
431
432static int
433check_result (tk, tmk, tl, lt)
434 time_t tk;
435 struct tm tmk;
436 time_t tl;
437 struct tm *lt;
438{
439 if (tk != tl || !lt || not_equal_tm (&tmk, lt))
440 {
441 printf ("mktime (");
442 print_tm (&tmk);
443 printf (")\nyields (");
444 print_tm (lt);
445 printf (") == %ld, should be %ld\n", (long) tl, (long) tk);
446 return 1;
447 }
448
449 return 0;
450}
451
452int
453main (argc, argv)
454 int argc;
455 char **argv;
456{
457 int status = 0;
458 struct tm tm, tmk, tml;
459 struct tm *lt;
460 time_t tk, tl;
461 char trailer;
462
463 if ((argc == 3 || argc == 4)
464 && (sscanf (argv[1], "%d-%d-%d%c",
465 &tm.tm_year, &tm.tm_mon, &tm.tm_mday, &trailer)
466 == 3)
467 && (sscanf (argv[2], "%d:%d:%d%c",
468 &tm.tm_hour, &tm.tm_min, &tm.tm_sec, &trailer)
469 == 3))
470 {
471 tm.tm_year -= TM_YEAR_BASE;
472 tm.tm_mon--;
473 tm.tm_isdst = argc == 3 ? -1 : atoi (argv[3]);
474 tmk = tm;
475 tl = mktime (&tmk);
476 lt = localtime (&tl);
477 if (lt)
478 {
479 tml = *lt;
480 lt = &tml;
481 }
482 printf ("mktime returns %ld == ", (long) tl);
483 print_tm (&tmk);
484 printf ("\n");
485 status = check_result (tl, tmk, tl, lt);
486 }
487 else if (argc == 4 || (argc == 5 && strcmp (argv[4], "-") == 0))
488 {
489 time_t from = atol (argv[1]);
490 time_t by = atol (argv[2]);
491 time_t to = atol (argv[3]);
492
493 if (argc == 4)
494 for (tl = from; tl <= to; tl += by)
495 {
496 lt = localtime (&tl);
497 if (lt)
498 {
499 tmk = tml = *lt;
500 tk = mktime (&tmk);
501 status |= check_result (tk, tmk, tl, tml);
502 }
503 else
504 {
505 printf ("localtime (%ld) yields 0\n", (long) tl);
506 status = 1;
507 }
508 }
509 else
510 for (tl = from; tl <= to; tl += by)
511 {
512 /* Null benchmark. */
513 lt = localtime (&tl);
514 if (lt)
515 {
516 tmk = tml = *lt;
517 tk = tl;
518 status |= check_result (tk, tmk, tl, tml);
519 }
520 else
521 {
522 printf ("localtime (%ld) yields 0\n", (long) tl);
523 status = 1;
524 }
525 }
526 }
527 else
528 printf ("Usage:\
529\t%s YYYY-MM-DD HH:MM:SS [ISDST] # Test given time.\n\
530\t%s FROM BY TO # Test values FROM, FROM+BY, ..., TO.\n\
531\t%s FROM BY TO - # Do not test those values (for benchmark).\n",
532 argv[0], argv[0], argv[0]);
533
534 return status;
535}
536
537#endif /* DEBUG */
538
539/*
540Local Variables:
541compile-command: "gcc -DDEBUG -DHAVE_LIMITS_H -DSTDC_HEADERS -Wall -W -O -g mktime.c -o mktime"
542End:
543*/
544
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