git

1
/*
2
 * GIT - The information manager from hell
3
 *
4
 * Copyright (C) Linus Torvalds, 2005
5
 */
6

7
#include "git-compat-util.h"
8
#include "date.h"
9
#include "gettext.h"
10
#include "pager.h"
11
#include "strbuf.h"
12

13
/*
14
 * This is like mktime, but without normalization of tm_wday and tm_yday.
15
 */
16
time_t tm_to_time_t(const struct tm *tm)
17
{
18
	static const int mdays[] = {
19
	    0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
20
	};
21
	int year = tm->tm_year - 70;
22
	int month = tm->tm_mon;
23
	int day = tm->tm_mday;
24

25
	if (year < 0 || year > 129) /* algo only works for 1970-2099 */
26
		return -1;
27
	if (month < 0 || month > 11) /* array bounds */
28
		return -1;
29
	if (month < 2 || (year + 2) % 4)
30
		day--;
31
	if (tm->tm_hour < 0 || tm->tm_min < 0 || tm->tm_sec < 0)
32
		return -1;
33
	return (year * 365 + (year + 1) / 4 + mdays[month] + day) * 24*60*60UL +
34
		tm->tm_hour * 60*60 + tm->tm_min * 60 + tm->tm_sec;
35
}
36

37
static const char *month_names[] = {
38
	"January", "February", "March", "April", "May", "June",
39
	"July", "August", "September", "October", "November", "December"
40
};
41

42
static const char *weekday_names[] = {
43
	"Sundays", "Mondays", "Tuesdays", "Wednesdays", "Thursdays", "Fridays", "Saturdays"
44
};
45

46
static time_t gm_time_t(timestamp_t time, int tz)
47
{
48
	int minutes;
49

50
	minutes = tz < 0 ? -tz : tz;
51
	minutes = (minutes / 100)*60 + (minutes % 100);
52
	minutes = tz < 0 ? -minutes : minutes;
53

54
	if (minutes > 0) {
55
		if (unsigned_add_overflows(time, minutes * 60))
56
			die("Timestamp+tz too large: %"PRItime" +%04d",
57
			    time, tz);
58
	} else if (time < -minutes * 60)
59
		die("Timestamp before Unix epoch: %"PRItime" %04d", time, tz);
60
	time += minutes * 60;
61
	if (date_overflows(time))
62
		die("Timestamp too large for this system: %"PRItime, time);
63
	return (time_t)time;
64
}
65

66
/*
67
 * The "tz" thing is passed in as this strange "decimal parse of tz"
68
 * thing, which means that tz -0100 is passed in as the integer -100,
69
 * even though it means "sixty minutes off"
70
 */
71
static struct tm *time_to_tm(timestamp_t time, int tz, struct tm *tm)
72
{
73
	time_t t = gm_time_t(time, tz);
74
	return gmtime_r(&t, tm);
75
}
76

77
static struct tm *time_to_tm_local(timestamp_t time, struct tm *tm)
78
{
79
	time_t t = time;
80
	return localtime_r(&t, tm);
81
}
82

83
/*
84
 * Fill in the localtime 'struct tm' for the supplied time,
85
 * and return the local tz.
86
 */
87
static int local_time_tzoffset(time_t t, struct tm *tm)
88
{
89
	time_t t_local;
90
	int offset, eastwest;
91

92
	localtime_r(&t, tm);
93
	t_local = tm_to_time_t(tm);
94
	if (t_local == -1)
95
		return 0; /* error; just use +0000 */
96
	if (t_local < t) {
97
		eastwest = -1;
98
		offset = t - t_local;
99
	} else {
100
		eastwest = 1;
101
		offset = t_local - t;
102
	}
103
	offset /= 60; /* in minutes */
104
	offset = (offset % 60) + ((offset / 60) * 100);
105
	return offset * eastwest;
106
}
107

108
/*
109
 * What value of "tz" was in effect back then at "time" in the
110
 * local timezone?
111
 */
112
static int local_tzoffset(timestamp_t time)
113
{
114
	struct tm tm;
115

116
	if (date_overflows(time))
117
		die("Timestamp too large for this system: %"PRItime, time);
118

119
	return local_time_tzoffset((time_t)time, &tm);
120
}
121

122
static void get_time(struct timeval *now)
123
{
124
	const char *x;
125

126
	x = getenv("GIT_TEST_DATE_NOW");
127
	if (x) {
128
		now->tv_sec = atoi(x);
129
		now->tv_usec = 0;
130
	}
131
	else
132
		gettimeofday(now, NULL);
133
}
134

135
void show_date_relative(timestamp_t time, struct strbuf *timebuf)
136
{
137
	struct timeval now;
138
	timestamp_t diff;
139

140
	get_time(&now);
141
	if (now.tv_sec < time) {
142
		strbuf_addstr(timebuf, _("in the future"));
143
		return;
144
	}
145
	diff = now.tv_sec - time;
146
	if (diff < 90) {
147
		strbuf_addf(timebuf,
148
			 Q_("%"PRItime" second ago", "%"PRItime" seconds ago", diff), diff);
149
		return;
150
	}
151
	/* Turn it into minutes */
152
	diff = (diff + 30) / 60;
153
	if (diff < 90) {
154
		strbuf_addf(timebuf,
155
			 Q_("%"PRItime" minute ago", "%"PRItime" minutes ago", diff), diff);
156
		return;
157
	}
158
	/* Turn it into hours */
159
	diff = (diff + 30) / 60;
160
	if (diff < 36) {
161
		strbuf_addf(timebuf,
162
			 Q_("%"PRItime" hour ago", "%"PRItime" hours ago", diff), diff);
163
		return;
164
	}
165
	/* We deal with number of days from here on */
166
	diff = (diff + 12) / 24;
167
	if (diff < 14) {
168
		strbuf_addf(timebuf,
169
			 Q_("%"PRItime" day ago", "%"PRItime" days ago", diff), diff);
170
		return;
171
	}
172
	/* Say weeks for the past 10 weeks or so */
173
	if (diff < 70) {
174
		strbuf_addf(timebuf,
175
			 Q_("%"PRItime" week ago", "%"PRItime" weeks ago", (diff + 3) / 7),
176
			 (diff + 3) / 7);
177
		return;
178
	}
179
	/* Say months for the past 12 months or so */
180
	if (diff < 365) {
181
		strbuf_addf(timebuf,
182
			 Q_("%"PRItime" month ago", "%"PRItime" months ago", (diff + 15) / 30),
183
			 (diff + 15) / 30);
184
		return;
185
	}
186
	/* Give years and months for 5 years or so */
187
	if (diff < 1825) {
188
		timestamp_t totalmonths = (diff * 12 * 2 + 365) / (365 * 2);
189
		timestamp_t years = totalmonths / 12;
190
		timestamp_t months = totalmonths % 12;
191
		if (months) {
192
			struct strbuf sb = STRBUF_INIT;
193
			strbuf_addf(&sb, Q_("%"PRItime" year", "%"PRItime" years", years), years);
194
			strbuf_addf(timebuf,
195
				 /* TRANSLATORS: "%s" is "<n> years" */
196
				 Q_("%s, %"PRItime" month ago", "%s, %"PRItime" months ago", months),
197
				 sb.buf, months);
198
			strbuf_release(&sb);
199
		} else
200
			strbuf_addf(timebuf,
201
				 Q_("%"PRItime" year ago", "%"PRItime" years ago", years), years);
202
		return;
203
	}
204
	/* Otherwise, just years. Centuries is probably overkill. */
205
	strbuf_addf(timebuf,
206
		 Q_("%"PRItime" year ago", "%"PRItime" years ago", (diff + 183) / 365),
207
		 (diff + 183) / 365);
208
}
209

210
struct date_mode date_mode_from_type(enum date_mode_type type)
211
{
212
	struct date_mode mode = DATE_MODE_INIT;
213
	if (type == DATE_STRFTIME)
214
		BUG("cannot create anonymous strftime date_mode struct");
215
	mode.type = type;
216
	return mode;
217
}
218

219
static void show_date_normal(struct strbuf *buf, timestamp_t time, struct tm *tm, int tz, struct tm *human_tm, int human_tz, int local)
220
{
221
	struct {
222
		unsigned int	year:1,
223
				date:1,
224
				wday:1,
225
				time:1,
226
				seconds:1,
227
				tz:1;
228
	} hide = { 0 };
229

230
	hide.tz = local || tz == human_tz;
231
	hide.year = tm->tm_year == human_tm->tm_year;
232
	if (hide.year) {
233
		if (tm->tm_mon == human_tm->tm_mon) {
234
			if (tm->tm_mday > human_tm->tm_mday) {
235
				/* Future date: think timezones */
236
			} else if (tm->tm_mday == human_tm->tm_mday) {
237
				hide.date = hide.wday = 1;
238
			} else if (tm->tm_mday + 5 > human_tm->tm_mday) {
239
				/* Leave just weekday if it was a few days ago */
240
				hide.date = 1;
241
			}
242
		}
243
	}
244

245
	/* Show "today" times as just relative times */
246
	if (hide.wday) {
247
		show_date_relative(time, buf);
248
		return;
249
	}
250

251
	/*
252
	 * Always hide seconds for human-readable.
253
	 * Hide timezone if showing date.
254
	 * Hide weekday and time if showing year.
255
	 *
256
	 * The logic here is two-fold:
257
	 *  (a) only show details when recent enough to matter
258
	 *  (b) keep the maximum length "similar", and in check
259
	 */
260
	if (human_tm->tm_year) {
261
		hide.seconds = 1;
262
		hide.tz |= !hide.date;
263
		hide.wday = hide.time = !hide.year;
264
	}
265

266
	if (!hide.wday)
267
		strbuf_addf(buf, "%.3s ", weekday_names[tm->tm_wday]);
268
	if (!hide.date)
269
		strbuf_addf(buf, "%.3s %d ", month_names[tm->tm_mon], tm->tm_mday);
270

271
	/* Do we want AM/PM depending on locale? */
272
	if (!hide.time) {
273
		strbuf_addf(buf, "%02d:%02d", tm->tm_hour, tm->tm_min);
274
		if (!hide.seconds)
275
			strbuf_addf(buf, ":%02d", tm->tm_sec);
276
	} else
277
		strbuf_rtrim(buf);
278

279
	if (!hide.year)
280
		strbuf_addf(buf, " %d", tm->tm_year + 1900);
281

282
	if (!hide.tz)
283
		strbuf_addf(buf, " %+05d", tz);
284
}
285

286
const char *show_date(timestamp_t time, int tz, struct date_mode mode)
287
{
288
	struct tm *tm;
289
	struct tm tmbuf = { 0 };
290
	struct tm human_tm = { 0 };
291
	int human_tz = -1;
292
	static struct strbuf timebuf = STRBUF_INIT;
293

294
	if (mode.type == DATE_UNIX) {
295
		strbuf_reset(&timebuf);
296
		strbuf_addf(&timebuf, "%"PRItime, time);
297
		return timebuf.buf;
298
	}
299

300
	if (mode.type == DATE_HUMAN) {
301
		struct timeval now;
302

303
		get_time(&now);
304

305
		/* Fill in the data for "current time" in human_tz and human_tm */
306
		human_tz = local_time_tzoffset(now.tv_sec, &human_tm);
307
	}
308

309
	if (mode.local)
310
		tz = local_tzoffset(time);
311

312
	if (mode.type == DATE_RAW) {
313
		strbuf_reset(&timebuf);
314
		strbuf_addf(&timebuf, "%"PRItime" %+05d", time, tz);
315
		return timebuf.buf;
316
	}
317

318
	if (mode.type == DATE_RELATIVE) {
319
		strbuf_reset(&timebuf);
320
		show_date_relative(time, &timebuf);
321
		return timebuf.buf;
322
	}
323

324
	if (mode.local)
325
		tm = time_to_tm_local(time, &tmbuf);
326
	else
327
		tm = time_to_tm(time, tz, &tmbuf);
328
	if (!tm) {
329
		tm = time_to_tm(0, 0, &tmbuf);
330
		tz = 0;
331
	}
332

333
	strbuf_reset(&timebuf);
334
	if (mode.type == DATE_SHORT)
335
		strbuf_addf(&timebuf, "%04d-%02d-%02d", tm->tm_year + 1900,
336
				tm->tm_mon + 1, tm->tm_mday);
337
	else if (mode.type == DATE_ISO8601)
338
		strbuf_addf(&timebuf, "%04d-%02d-%02d %02d:%02d:%02d %+05d",
339
				tm->tm_year + 1900,
340
				tm->tm_mon + 1,
341
				tm->tm_mday,
342
				tm->tm_hour, tm->tm_min, tm->tm_sec,
343
				tz);
344
	else if (mode.type == DATE_ISO8601_STRICT) {
345
		strbuf_addf(&timebuf, "%04d-%02d-%02dT%02d:%02d:%02d",
346
				tm->tm_year + 1900,
347
				tm->tm_mon + 1,
348
				tm->tm_mday,
349
				tm->tm_hour, tm->tm_min, tm->tm_sec);
350
		if (tz == 0) {
351
			strbuf_addch(&timebuf, 'Z');
352
		} else {
353
			strbuf_addch(&timebuf, tz >= 0 ? '+' : '-');
354
			tz = abs(tz);
355
			strbuf_addf(&timebuf, "%02d:%02d", tz / 100, tz % 100);
356
		}
357
	} else if (mode.type == DATE_RFC2822)
358
		strbuf_addf(&timebuf, "%.3s, %d %.3s %d %02d:%02d:%02d %+05d",
359
			weekday_names[tm->tm_wday], tm->tm_mday,
360
			month_names[tm->tm_mon], tm->tm_year + 1900,
361
			tm->tm_hour, tm->tm_min, tm->tm_sec, tz);
362
	else if (mode.type == DATE_STRFTIME)
363
		strbuf_addftime(&timebuf, mode.strftime_fmt, tm, tz,
364
				!mode.local);
365
	else
366
		show_date_normal(&timebuf, time, tm, tz, &human_tm, human_tz, mode.local);
367
	return timebuf.buf;
368
}
369

370
/*
371
 * Check these. And note how it doesn't do the summer-time conversion.
372
 *
373
 * In my world, it's always summer, and things are probably a bit off
374
 * in other ways too.
375
 */
376
static const struct {
377
	const char *name;
378
	int offset;
379
	int dst;
380
} timezone_names[] = {
381
	{ "IDLW", -12, 0, },	/* International Date Line West */
382
	{ "NT",   -11, 0, },	/* Nome */
383
	{ "CAT",  -10, 0, },	/* Central Alaska */
384
	{ "HST",  -10, 0, },	/* Hawaii Standard */
385
	{ "HDT",  -10, 1, },	/* Hawaii Daylight */
386
	{ "YST",   -9, 0, },	/* Yukon Standard */
387
	{ "YDT",   -9, 1, },	/* Yukon Daylight */
388
	{ "PST",   -8, 0, },	/* Pacific Standard */
389
	{ "PDT",   -8, 1, },	/* Pacific Daylight */
390
	{ "MST",   -7, 0, },	/* Mountain Standard */
391
	{ "MDT",   -7, 1, },	/* Mountain Daylight */
392
	{ "CST",   -6, 0, },	/* Central Standard */
393
	{ "CDT",   -6, 1, },	/* Central Daylight */
394
	{ "EST",   -5, 0, },	/* Eastern Standard */
395
	{ "EDT",   -5, 1, },	/* Eastern Daylight */
396
	{ "AST",   -3, 0, },	/* Atlantic Standard */
397
	{ "ADT",   -3, 1, },	/* Atlantic Daylight */
398
	{ "WAT",   -1, 0, },	/* West Africa */
399

400
	{ "GMT",    0, 0, },	/* Greenwich Mean */
401
	{ "UTC",    0, 0, },	/* Universal (Coordinated) */
402
	{ "Z",      0, 0, },    /* Zulu, alias for UTC */
403

404
	{ "WET",    0, 0, },	/* Western European */
405
	{ "BST",    0, 1, },	/* British Summer */
406
	{ "CET",   +1, 0, },	/* Central European */
407
	{ "MET",   +1, 0, },	/* Middle European */
408
	{ "MEWT",  +1, 0, },	/* Middle European Winter */
409
	{ "MEST",  +1, 1, },	/* Middle European Summer */
410
	{ "CEST",  +1, 1, },	/* Central European Summer */
411
	{ "MESZ",  +1, 1, },	/* Middle European Summer */
412
	{ "FWT",   +1, 0, },	/* French Winter */
413
	{ "FST",   +1, 1, },	/* French Summer */
414
	{ "EET",   +2, 0, },	/* Eastern Europe, USSR Zone 1 */
415
	{ "EEST",  +2, 1, },	/* Eastern European Daylight */
416
	{ "WAST",  +7, 0, },	/* West Australian Standard */
417
	{ "WADT",  +7, 1, },	/* West Australian Daylight */
418
	{ "CCT",   +8, 0, },	/* China Coast, USSR Zone 7 */
419
	{ "JST",   +9, 0, },	/* Japan Standard, USSR Zone 8 */
420
	{ "EAST", +10, 0, },	/* Eastern Australian Standard */
421
	{ "EADT", +10, 1, },	/* Eastern Australian Daylight */
422
	{ "GST",  +10, 0, },	/* Guam Standard, USSR Zone 9 */
423
	{ "NZT",  +12, 0, },	/* New Zealand */
424
	{ "NZST", +12, 0, },	/* New Zealand Standard */
425
	{ "NZDT", +12, 1, },	/* New Zealand Daylight */
426
	{ "IDLE", +12, 0, },	/* International Date Line East */
427
};
428

429
static int match_string(const char *date, const char *str)
430
{
431
	int i = 0;
432

433
	for (i = 0; *date; date++, str++, i++) {
434
		if (*date == *str)
435
			continue;
436
		if (toupper(*date) == toupper(*str))
437
			continue;
438
		if (!isalnum(*date))
439
			break;
440
		return 0;
441
	}
442
	return i;
443
}
444

445
static int skip_alpha(const char *date)
446
{
447
	int i = 0;
448
	do {
449
		i++;
450
	} while (isalpha(date[i]));
451
	return i;
452
}
453

454
/*
455
* Parse month, weekday, or timezone name
456
*/
457
static int match_alpha(const char *date, struct tm *tm, int *offset)
458
{
459
	int i;
460

461
	for (i = 0; i < 12; i++) {
462
		int match = match_string(date, month_names[i]);
463
		if (match >= 3) {
464
			tm->tm_mon = i;
465
			return match;
466
		}
467
	}
468

469
	for (i = 0; i < 7; i++) {
470
		int match = match_string(date, weekday_names[i]);
471
		if (match >= 3) {
472
			tm->tm_wday = i;
473
			return match;
474
		}
475
	}
476

477
	for (i = 0; i < ARRAY_SIZE(timezone_names); i++) {
478
		int match = match_string(date, timezone_names[i].name);
479
		if (match >= 3 || match == strlen(timezone_names[i].name)) {
480
			int off = timezone_names[i].offset;
481

482
			/* This is bogus, but we like summer */
483
			off += timezone_names[i].dst;
484

485
			/* Only use the tz name offset if we don't have anything better */
486
			if (*offset == -1)
487
				*offset = 60*off;
488

489
			return match;
490
		}
491
	}
492

493
	if (match_string(date, "PM") == 2) {
494
		tm->tm_hour = (tm->tm_hour % 12) + 12;
495
		return 2;
496
	}
497

498
	if (match_string(date, "AM") == 2) {
499
		tm->tm_hour = (tm->tm_hour % 12) + 0;
500
		return 2;
501
	}
502

503
	/* ISO-8601 allows yyyymmDD'T'HHMMSS, with less precision */
504
	if (*date == 'T' && isdigit(date[1]) && tm->tm_hour == -1) {
505
		tm->tm_min = tm->tm_sec = 0;
506
		return 1;
507
	}
508

509
	/* BAD CRAP */
510
	return skip_alpha(date);
511
}
512

513
static int set_date(int year, int month, int day, struct tm *now_tm, time_t now, struct tm *tm)
514
{
515
	if (month > 0 && month < 13 && day > 0 && day < 32) {
516
		struct tm check = *tm;
517
		struct tm *r = (now_tm ? &check : tm);
518
		time_t specified;
519

520
		r->tm_mon = month - 1;
521
		r->tm_mday = day;
522
		if (year == -1) {
523
			if (!now_tm)
524
				return 1;
525
			r->tm_year = now_tm->tm_year;
526
		}
527
		else if (year >= 1970 && year < 2100)
528
			r->tm_year = year - 1900;
529
		else if (year > 70 && year < 100)
530
			r->tm_year = year;
531
		else if (year < 38)
532
			r->tm_year = year + 100;
533
		else
534
			return -1;
535
		if (!now_tm)
536
			return 0;
537

538
		specified = tm_to_time_t(r);
539

540
		/* Be it commit time or author time, it does not make
541
		 * sense to specify timestamp way into the future.  Make
542
		 * sure it is not later than ten days from now...
543
		 */
544
		if ((specified != -1) && (now + 10*24*3600 < specified))
545
			return -1;
546
		tm->tm_mon = r->tm_mon;
547
		tm->tm_mday = r->tm_mday;
548
		if (year != -1)
549
			tm->tm_year = r->tm_year;
550
		return 0;
551
	}
552
	return -1;
553
}
554

555
static int set_time(long hour, long minute, long second, struct tm *tm)
556
{
557
	/* We accept 61st second because of leap second */
558
	if (0 <= hour && hour <= 24 &&
559
	    0 <= minute && minute < 60 &&
560
	    0 <= second && second <= 60) {
561
		tm->tm_hour = hour;
562
		tm->tm_min = minute;
563
		tm->tm_sec = second;
564
		return 0;
565
	}
566
	return -1;
567
}
568

569
static int is_date_known(struct tm *tm)
570
{
571
	return tm->tm_year != -1 && tm->tm_mon != -1 && tm->tm_mday != -1;
572
}
573

574
static int match_multi_number(timestamp_t num, char c, const char *date,
575
			      char *end, struct tm *tm, time_t now)
576
{
577
	struct tm now_tm;
578
	struct tm *refuse_future;
579
	long num2, num3;
580

581
	num2 = strtol(end+1, &end, 10);
582
	num3 = -1;
583
	if (*end == c && isdigit(end[1]))
584
		num3 = strtol(end+1, &end, 10);
585

586
	/* Time? Date? */
587
	switch (c) {
588
	case ':':
589
		if (num3 < 0)
590
			num3 = 0;
591
		if (set_time(num, num2, num3, tm) == 0) {
592
			/*
593
			 * If %H:%M:%S was just parsed followed by: .<num4>
594
			 * Consider (& discard) it as fractional second
595
			 * if %Y%m%d is parsed before.
596
			 */
597
			if (*end == '.' && isdigit(end[1]) && is_date_known(tm))
598
				strtol(end + 1, &end, 10);
599
			break;
600
		}
601
		return 0;
602

603
	case '-':
604
	case '/':
605
	case '.':
606
		if (!now)
607
			now = time(NULL);
608
		refuse_future = NULL;
609
		if (gmtime_r(&now, &now_tm))
610
			refuse_future = &now_tm;
611

612
		if (num > 70) {
613
			/* yyyy-mm-dd? */
614
			if (set_date(num, num2, num3, NULL, now, tm) == 0)
615
				break;
616
			/* yyyy-dd-mm? */
617
			if (set_date(num, num3, num2, NULL, now, tm) == 0)
618
				break;
619
		}
620
		/* Our eastern European friends say dd.mm.yy[yy]
621
		 * is the norm there, so giving precedence to
622
		 * mm/dd/yy[yy] form only when separator is not '.'
623
		 */
624
		if (c != '.' &&
625
		    set_date(num3, num, num2, refuse_future, now, tm) == 0)
626
			break;
627
		/* European dd.mm.yy[yy] or funny US dd/mm/yy[yy] */
628
		if (set_date(num3, num2, num, refuse_future, now, tm) == 0)
629
			break;
630
		/* Funny European mm.dd.yy */
631
		if (c == '.' &&
632
		    set_date(num3, num, num2, refuse_future, now, tm) == 0)
633
			break;
634
		return 0;
635
	}
636
	return end - date;
637
}
638

639
/*
640
 * Have we filled in any part of the time/date yet?
641
 * We just do a binary 'and' to see if the sign bit
642
 * is set in all the values.
643
 */
644
static inline int nodate(struct tm *tm)
645
{
646
	return (tm->tm_year &
647
		tm->tm_mon &
648
		tm->tm_mday &
649
		tm->tm_hour &
650
		tm->tm_min &
651
		tm->tm_sec) < 0;
652
}
653

654
/*
655
 * Have we seen an ISO-8601-alike date, i.e. 20220101T0,
656
 * In which, hour is still unset,
657
 * and minutes and second has been set to 0.
658
 */
659
static inline int maybeiso8601(struct tm *tm)
660
{
661
	return tm->tm_hour == -1 &&
662
		tm->tm_min == 0 &&
663
		tm->tm_sec == 0;
664
}
665

666
/*
667
 * We've seen a digit. Time? Year? Date?
668
 */
669
static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt)
670
{
671
	int n;
672
	char *end;
673
	timestamp_t num;
674

675
	num = parse_timestamp(date, &end, 10);
676

677
	/*
678
	 * Seconds since 1970? We trigger on that for any numbers with
679
	 * more than 8 digits. This is because we don't want to rule out
680
	 * numbers like 20070606 as a YYYYMMDD date.
681
	 */
682
	if (num >= 100000000 && nodate(tm)) {
683
		time_t time = num;
684
		if (gmtime_r(&time, tm)) {
685
			*tm_gmt = 1;
686
			return end - date;
687
		}
688
	}
689

690
	/*
691
	 * Check for special formats: num[-.:/]num[same]num
692
	 */
693
	switch (*end) {
694
	case ':':
695
	case '.':
696
	case '/':
697
	case '-':
698
		if (isdigit(end[1])) {
699
			int match = match_multi_number(num, *end, date, end, tm, 0);
700
			if (match)
701
				return match;
702
		}
703
	}
704

705
	/*
706
	 * None of the special formats? Try to guess what
707
	 * the number meant. We use the number of digits
708
	 * to make a more educated guess..
709
	 */
710
	n = 0;
711
	do {
712
		n++;
713
	} while (isdigit(date[n]));
714

715
	/* 8 digits, compact style of ISO-8601's date: YYYYmmDD */
716
	/* 6 digits, compact style of ISO-8601's time: HHMMSS */
717
	if (n == 8 || n == 6) {
718
		unsigned int num1 = num / 10000;
719
		unsigned int num2 = (num % 10000) / 100;
720
		unsigned int num3 = num % 100;
721
		if (n == 8)
722
			set_date(num1, num2, num3, NULL, time(NULL), tm);
723
		else if (n == 6 && set_time(num1, num2, num3, tm) == 0 &&
724
			 *end == '.' && isdigit(end[1]))
725
			strtoul(end + 1, &end, 10);
726
		return end - date;
727
	}
728

729
	/* reduced precision of ISO-8601's time: HHMM or HH */
730
	if (maybeiso8601(tm)) {
731
		unsigned int num1 = num;
732
		unsigned int num2 = 0;
733
		if (n == 4) {
734
			num1 = num / 100;
735
			num2 = num % 100;
736
		}
737
		if ((n == 4 || n == 2) && !nodate(tm) &&
738
		    set_time(num1, num2, 0, tm) == 0)
739
			return n;
740
		/*
741
		 * We thought this is an ISO-8601 time string,
742
		 * we set minutes and seconds to 0,
743
		 * turn out it isn't, rollback the change.
744
		 */
745
		tm->tm_min = tm->tm_sec = -1;
746
	}
747

748
	/* Four-digit year or a timezone? */
749
	if (n == 4) {
750
		if (num <= 1400 && *offset == -1) {
751
			unsigned int minutes = num % 100;
752
			unsigned int hours = num / 100;
753
			*offset = hours*60 + minutes;
754
		} else if (num > 1900 && num < 2100)
755
			tm->tm_year = num - 1900;
756
		return n;
757
	}
758

759
	/*
760
	 * Ignore lots of numerals. We took care of 4-digit years above.
761
	 * Days or months must be one or two digits.
762
	 */
763
	if (n > 2)
764
		return n;
765

766
	/*
767
	 * NOTE! We will give precedence to day-of-month over month or
768
	 * year numbers in the 1-12 range. So 05 is always "mday 5",
769
	 * unless we already have a mday..
770
	 *
771
	 * IOW, 01 Apr 05 parses as "April 1st, 2005".
772
	 */
773
	if (num > 0 && num < 32 && tm->tm_mday < 0) {
774
		tm->tm_mday = num;
775
		return n;
776
	}
777

778
	/* Two-digit year? */
779
	if (n == 2 && tm->tm_year < 0) {
780
		if (num < 10 && tm->tm_mday >= 0) {
781
			tm->tm_year = num + 100;
782
			return n;
783
		}
784
		if (num >= 70) {
785
			tm->tm_year = num;
786
			return n;
787
		}
788
	}
789

790
	if (num > 0 && num < 13 && tm->tm_mon < 0)
791
		tm->tm_mon = num-1;
792

793
	return n;
794
}
795

796
static int match_tz(const char *date, int *offp)
797
{
798
	char *end;
799
	int hour = strtoul(date + 1, &end, 10);
800
	int n = end - (date + 1);
801
	int min = 0;
802

803
	if (n == 4) {
804
		/* hhmm */
805
		min = hour % 100;
806
		hour = hour / 100;
807
	} else if (n != 2) {
808
		min = 99; /* random crap */
809
	} else if (*end == ':') {
810
		/* hh:mm? */
811
		min = strtoul(end + 1, &end, 10);
812
		if (end - (date + 1) != 5)
813
			min = 99; /* random crap */
814
	} /* otherwise we parsed "hh" */
815

816
	/*
817
	 * Don't accept any random crap. Even though some places have
818
	 * offset larger than 12 hours (e.g. Pacific/Kiritimati is at
819
	 * UTC+14), there is something wrong if hour part is much
820
	 * larger than that. We might also want to check that the
821
	 * minutes are divisible by 15 or something too. (Offset of
822
	 * Kathmandu, Nepal is UTC+5:45)
823
	 */
824
	if (min < 60 && hour < 24) {
825
		int offset = hour * 60 + min;
826
		if (*date == '-')
827
			offset = -offset;
828
		*offp = offset;
829
	}
830
	return end - date;
831
}
832

833
static void date_string(timestamp_t date, int offset, struct strbuf *buf)
834
{
835
	int sign = '+';
836

837
	if (offset < 0) {
838
		offset = -offset;
839
		sign = '-';
840
	}
841
	strbuf_addf(buf, "%"PRItime" %c%02d%02d", date, sign, offset / 60, offset % 60);
842
}
843

844
/*
845
 * Parse a string like "0 +0000" as ancient timestamp near epoch, but
846
 * only when it appears not as part of any other string.
847
 */
848
static int match_object_header_date(const char *date, timestamp_t *timestamp, int *offset)
849
{
850
	char *end;
851
	timestamp_t stamp;
852
	int ofs;
853

854
	if (*date < '0' || '9' < *date)
855
		return -1;
856
	stamp = parse_timestamp(date, &end, 10);
857
	if (*end != ' ' || stamp == TIME_MAX || (end[1] != '+' && end[1] != '-'))
858
		return -1;
859
	date = end + 2;
860
	ofs = strtol(date, &end, 10);
861
	if ((*end != '\0' && (*end != '\n')) || end != date + 4)
862
		return -1;
863
	ofs = (ofs / 100) * 60 + (ofs % 100);
864
	if (date[-1] == '-')
865
		ofs = -ofs;
866
	*timestamp = stamp;
867
	*offset = ofs;
868
	return 0;
869
}
870

871

872
/* timestamp of 2099-12-31T23:59:59Z, including 32 leap days */
873
static const timestamp_t timestamp_max = (((timestamp_t)2100 - 1970) * 365 + 32) * 24 * 60 * 60 - 1;
874

875
/* Gr. strptime is crap for this; it doesn't have a way to require RFC2822
876
   (i.e. English) day/month names, and it doesn't work correctly with %z. */
877
int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset)
878
{
879
	struct tm tm;
880
	int tm_gmt;
881
	timestamp_t dummy_timestamp;
882
	int dummy_offset;
883

884
	if (!timestamp)
885
		timestamp = &dummy_timestamp;
886
	if (!offset)
887
		offset = &dummy_offset;
888

889
	memset(&tm, 0, sizeof(tm));
890
	tm.tm_year = -1;
891
	tm.tm_mon = -1;
892
	tm.tm_mday = -1;
893
	tm.tm_isdst = -1;
894
	tm.tm_hour = -1;
895
	tm.tm_min = -1;
896
	tm.tm_sec = -1;
897
	*offset = -1;
898
	tm_gmt = 0;
899

900
	if (*date == '@' &&
901
	    !match_object_header_date(date + 1, timestamp, offset))
902
		return 0; /* success */
903
	for (;;) {
904
		int match = 0;
905
		unsigned char c = *date;
906

907
		/* Stop at end of string or newline */
908
		if (!c || c == '\n')
909
			break;
910

911
		if (isalpha(c))
912
			match = match_alpha(date, &tm, offset);
913
		else if (isdigit(c))
914
			match = match_digit(date, &tm, offset, &tm_gmt);
915
		else if ((c == '-' || c == '+') && isdigit(date[1]))
916
			match = match_tz(date, offset);
917

918
		if (!match) {
919
			/* BAD CRAP */
920
			match = 1;
921
		}
922

923
		date += match;
924
	}
925

926
	/* do not use mktime(), which uses local timezone, here */
927
	*timestamp = tm_to_time_t(&tm);
928
	if (*timestamp == -1)
929
		return -1;
930

931
	if (*offset == -1) {
932
		time_t temp_time;
933

934
		/* gmtime_r() in match_digit() may have clobbered it */
935
		tm.tm_isdst = -1;
936
		temp_time = mktime(&tm);
937
		if ((time_t)*timestamp > temp_time) {
938
			*offset = ((time_t)*timestamp - temp_time) / 60;
939
		} else {
940
			*offset = -(int)((temp_time - (time_t)*timestamp) / 60);
941
		}
942
	}
943

944
	if (!tm_gmt) {
945
		if (*offset > 0 && *offset * 60 > *timestamp)
946
			return -1;
947
		if (*offset < 0 && -*offset * 60 > timestamp_max - *timestamp)
948
			return -1;
949
		*timestamp -= *offset * 60;
950
	}
951

952
	return 0; /* success */
953
}
954

955
int parse_expiry_date(const char *date, timestamp_t *timestamp)
956
{
957
	int errors = 0;
958

959
	if (!strcmp(date, "never") || !strcmp(date, "false"))
960
		*timestamp = 0;
961
	else if (!strcmp(date, "all") || !strcmp(date, "now"))
962
		/*
963
		 * We take over "now" here, which usually translates
964
		 * to the current timestamp.  This is because the user
965
		 * really means to expire everything that was done in
966
		 * the past, and by definition reflogs are the record
967
		 * of the past, and there is nothing from the future
968
		 * to be kept.
969
		 */
970
		*timestamp = TIME_MAX;
971
	else
972
		*timestamp = approxidate_careful(date, &errors);
973

974
	return errors;
975
}
976

977
int parse_date(const char *date, struct strbuf *result)
978
{
979
	timestamp_t timestamp;
980
	int offset;
981
	if (parse_date_basic(date, &timestamp, &offset))
982
		return -1;
983
	date_string(timestamp, offset, result);
984
	return 0;
985
}
986

987
static enum date_mode_type parse_date_type(const char *format, const char **end)
988
{
989
	if (skip_prefix(format, "relative", end))
990
		return DATE_RELATIVE;
991
	if (skip_prefix(format, "iso8601-strict", end) ||
992
	    skip_prefix(format, "iso-strict", end))
993
		return DATE_ISO8601_STRICT;
994
	if (skip_prefix(format, "iso8601", end) ||
995
	    skip_prefix(format, "iso", end))
996
		return DATE_ISO8601;
997
	if (skip_prefix(format, "rfc2822", end) ||
998
	    skip_prefix(format, "rfc", end))
999
		return DATE_RFC2822;
1000
	if (skip_prefix(format, "short", end))
1001
		return DATE_SHORT;
1002
	if (skip_prefix(format, "default", end))
1003
		return DATE_NORMAL;
1004
	if (skip_prefix(format, "human", end))
1005
		return DATE_HUMAN;
1006
	if (skip_prefix(format, "raw", end))
1007
		return DATE_RAW;
1008
	if (skip_prefix(format, "unix", end))
1009
		return DATE_UNIX;
1010
	if (skip_prefix(format, "format", end))
1011
		return DATE_STRFTIME;
1012
	/*
1013
	 * Please update $__git_log_date_formats in
1014
	 * git-completion.bash when you add new formats.
1015
	 */
1016

1017
	die("unknown date format %s", format);
1018
}
1019

1020
void parse_date_format(const char *format, struct date_mode *mode)
1021
{
1022
	const char *p;
1023

1024
	/* "auto:foo" is "if tty/pager, then foo, otherwise normal" */
1025
	if (skip_prefix(format, "auto:", &p)) {
1026
		if (isatty(1) || pager_in_use())
1027
			format = p;
1028
		else
1029
			format = "default";
1030
	}
1031

1032
	/* historical alias */
1033
	if (!strcmp(format, "local"))
1034
		format = "default-local";
1035

1036
	mode->type = parse_date_type(format, &p);
1037
	mode->local = 0;
1038

1039
	if (skip_prefix(p, "-local", &p))
1040
		mode->local = 1;
1041

1042
	if (mode->type == DATE_STRFTIME) {
1043
		if (!skip_prefix(p, ":", &p))
1044
			die("date format missing colon separator: %s", format);
1045
		mode->strftime_fmt = xstrdup(p);
1046
	} else if (*p)
1047
		die("unknown date format %s", format);
1048
}
1049

1050
void date_mode_release(struct date_mode *mode)
1051
{
1052
	free((char *)mode->strftime_fmt);
1053
}
1054

1055
void datestamp(struct strbuf *out)
1056
{
1057
	time_t now;
1058
	int offset;
1059
	struct tm tm = { 0 };
1060

1061
	time(&now);
1062

1063
	offset = tm_to_time_t(localtime_r(&now, &tm)) - now;
1064
	offset /= 60;
1065

1066
	date_string(now, offset, out);
1067
}
1068

1069
/*
1070
 * Relative time update (eg "2 days ago").  If we haven't set the time
1071
 * yet, we need to set it from current time.
1072
 */
1073
static time_t update_tm(struct tm *tm, struct tm *now, time_t sec)
1074
{
1075
	time_t n;
1076

1077
	if (tm->tm_mday < 0)
1078
		tm->tm_mday = now->tm_mday;
1079
	if (tm->tm_mon < 0)
1080
		tm->tm_mon = now->tm_mon;
1081
	if (tm->tm_year < 0) {
1082
		tm->tm_year = now->tm_year;
1083
		if (tm->tm_mon > now->tm_mon)
1084
			tm->tm_year--;
1085
	}
1086

1087
	n = mktime(tm) - sec;
1088
	localtime_r(&n, tm);
1089
	return n;
1090
}
1091

1092
/*
1093
 * Do we have a pending number at the end, or when
1094
 * we see a new one? Let's assume it's a month day,
1095
 * as in "Dec 6, 1992"
1096
 */
1097
static void pending_number(struct tm *tm, int *num)
1098
{
1099
	int number = *num;
1100

1101
	if (number) {
1102
		*num = 0;
1103
		if (tm->tm_mday < 0 && number < 32)
1104
			tm->tm_mday = number;
1105
		else if (tm->tm_mon < 0 && number < 13)
1106
			tm->tm_mon = number-1;
1107
		else if (tm->tm_year < 0) {
1108
			if (number > 1969 && number < 2100)
1109
				tm->tm_year = number - 1900;
1110
			else if (number > 69 && number < 100)
1111
				tm->tm_year = number;
1112
			else if (number < 38)
1113
				tm->tm_year = 100 + number;
1114
			/* We screw up for number = 00 ? */
1115
		}
1116
	}
1117
}
1118

1119
static void date_now(struct tm *tm, struct tm *now, int *num)
1120
{
1121
	*num = 0;
1122
	update_tm(tm, now, 0);
1123
}
1124

1125
static void date_yesterday(struct tm *tm, struct tm *now, int *num)
1126
{
1127
	*num = 0;
1128
	update_tm(tm, now, 24*60*60);
1129
}
1130

1131
static void date_time(struct tm *tm, struct tm *now, int hour)
1132
{
1133
	if (tm->tm_hour < hour)
1134
		update_tm(tm, now, 24*60*60);
1135
	tm->tm_hour = hour;
1136
	tm->tm_min = 0;
1137
	tm->tm_sec = 0;
1138
}
1139

1140
static void date_midnight(struct tm *tm, struct tm *now, int *num)
1141
{
1142
	pending_number(tm, num);
1143
	date_time(tm, now, 0);
1144
}
1145

1146
static void date_noon(struct tm *tm, struct tm *now, int *num)
1147
{
1148
	pending_number(tm, num);
1149
	date_time(tm, now, 12);
1150
}
1151

1152
static void date_tea(struct tm *tm, struct tm *now, int *num)
1153
{
1154
	pending_number(tm, num);
1155
	date_time(tm, now, 17);
1156
}
1157

1158
static void date_pm(struct tm *tm, struct tm *now UNUSED, int *num)
1159
{
1160
	int hour, n = *num;
1161
	*num = 0;
1162

1163
	hour = tm->tm_hour;
1164
	if (n) {
1165
		hour = n;
1166
		tm->tm_min = 0;
1167
		tm->tm_sec = 0;
1168
	}
1169
	tm->tm_hour = (hour % 12) + 12;
1170
}
1171

1172
static void date_am(struct tm *tm, struct tm *now UNUSED, int *num)
1173
{
1174
	int hour, n = *num;
1175
	*num = 0;
1176

1177
	hour = tm->tm_hour;
1178
	if (n) {
1179
		hour = n;
1180
		tm->tm_min = 0;
1181
		tm->tm_sec = 0;
1182
	}
1183
	tm->tm_hour = (hour % 12);
1184
}
1185

1186
static void date_never(struct tm *tm, struct tm *now UNUSED, int *num)
1187
{
1188
	time_t n = 0;
1189
	localtime_r(&n, tm);
1190
	*num = 0;
1191
}
1192

1193
static const struct special {
1194
	const char *name;
1195
	void (*fn)(struct tm *, struct tm *, int *);
1196
} special[] = {
1197
	{ "yesterday", date_yesterday },
1198
	{ "noon", date_noon },
1199
	{ "midnight", date_midnight },
1200
	{ "tea", date_tea },
1201
	{ "PM", date_pm },
1202
	{ "AM", date_am },
1203
	{ "never", date_never },
1204
	{ "now", date_now },
1205
	{ NULL }
1206
};
1207

1208
static const char *number_name[] = {
1209
	"zero", "one", "two", "three", "four",
1210
	"five", "six", "seven", "eight", "nine", "ten",
1211
};
1212

1213
static const struct typelen {
1214
	const char *type;
1215
	int length;
1216
} typelen[] = {
1217
	{ "seconds", 1 },
1218
	{ "minutes", 60 },
1219
	{ "hours", 60*60 },
1220
	{ "days", 24*60*60 },
1221
	{ "weeks", 7*24*60*60 },
1222
	{ NULL }
1223
};
1224

1225
static const char *approxidate_alpha(const char *date, struct tm *tm, struct tm *now, int *num, int *touched)
1226
{
1227
	const struct typelen *tl;
1228
	const struct special *s;
1229
	const char *end = date;
1230
	int i;
1231

1232
	while (isalpha(*++end))
1233
		;
1234

1235
	for (i = 0; i < 12; i++) {
1236
		int match = match_string(date, month_names[i]);
1237
		if (match >= 3) {
1238
			tm->tm_mon = i;
1239
			*touched = 1;
1240
			return end;
1241
		}
1242
	}
1243

1244
	for (s = special; s->name; s++) {
1245
		int len = strlen(s->name);
1246
		if (match_string(date, s->name) == len) {
1247
			s->fn(tm, now, num);
1248
			*touched = 1;
1249
			return end;
1250
		}
1251
	}
1252

1253
	if (!*num) {
1254
		for (i = 1; i < 11; i++) {
1255
			int len = strlen(number_name[i]);
1256
			if (match_string(date, number_name[i]) == len) {
1257
				*num = i;
1258
				*touched = 1;
1259
				return end;
1260
			}
1261
		}
1262
		if (match_string(date, "last") == 4) {
1263
			*num = 1;
1264
			*touched = 1;
1265
		}
1266
		return end;
1267
	}
1268

1269
	tl = typelen;
1270
	while (tl->type) {
1271
		int len = strlen(tl->type);
1272
		if (match_string(date, tl->type) >= len-1) {
1273
			update_tm(tm, now, tl->length * *num);
1274
			*num = 0;
1275
			*touched = 1;
1276
			return end;
1277
		}
1278
		tl++;
1279
	}
1280

1281
	for (i = 0; i < 7; i++) {
1282
		int match = match_string(date, weekday_names[i]);
1283
		if (match >= 3) {
1284
			int diff, n = *num -1;
1285
			*num = 0;
1286

1287
			diff = tm->tm_wday - i;
1288
			if (diff <= 0)
1289
				n++;
1290
			diff += 7*n;
1291

1292
			update_tm(tm, now, diff * 24 * 60 * 60);
1293
			*touched = 1;
1294
			return end;
1295
		}
1296
	}
1297

1298
	if (match_string(date, "months") >= 5) {
1299
		int n;
1300
		update_tm(tm, now, 0); /* fill in date fields if needed */
1301
		n = tm->tm_mon - *num;
1302
		*num = 0;
1303
		while (n < 0) {
1304
			n += 12;
1305
			tm->tm_year--;
1306
		}
1307
		tm->tm_mon = n;
1308
		*touched = 1;
1309
		return end;
1310
	}
1311

1312
	if (match_string(date, "years") >= 4) {
1313
		update_tm(tm, now, 0); /* fill in date fields if needed */
1314
		tm->tm_year -= *num;
1315
		*num = 0;
1316
		*touched = 1;
1317
		return end;
1318
	}
1319

1320
	return end;
1321
}
1322

1323
static const char *approxidate_digit(const char *date, struct tm *tm, int *num,
1324
				     time_t now)
1325
{
1326
	char *end;
1327
	timestamp_t number = parse_timestamp(date, &end, 10);
1328

1329
	switch (*end) {
1330
	case ':':
1331
	case '.':
1332
	case '/':
1333
	case '-':
1334
		if (isdigit(end[1])) {
1335
			int match = match_multi_number(number, *end, date, end,
1336
						       tm, now);
1337
			if (match)
1338
				return date + match;
1339
		}
1340
	}
1341

1342
	/* Accept zero-padding only for small numbers ("Dec 02", never "Dec 0002") */
1343
	if (date[0] != '0' || end - date <= 2)
1344
		*num = number;
1345
	return end;
1346
}
1347

1348
static timestamp_t approxidate_str(const char *date,
1349
				   const struct timeval *tv,
1350
				   int *error_ret)
1351
{
1352
	int number = 0;
1353
	int touched = 0;
1354
	struct tm tm, now;
1355
	time_t time_sec;
1356

1357
	time_sec = tv->tv_sec;
1358
	localtime_r(&time_sec, &tm);
1359
	now = tm;
1360

1361
	tm.tm_year = -1;
1362
	tm.tm_mon = -1;
1363
	tm.tm_mday = -1;
1364

1365
	for (;;) {
1366
		unsigned char c = *date;
1367
		if (!c)
1368
			break;
1369
		date++;
1370
		if (isdigit(c)) {
1371
			pending_number(&tm, &number);
1372
			date = approxidate_digit(date-1, &tm, &number, time_sec);
1373
			touched = 1;
1374
			continue;
1375
		}
1376
		if (isalpha(c))
1377
			date = approxidate_alpha(date-1, &tm, &now, &number, &touched);
1378
	}
1379
	pending_number(&tm, &number);
1380
	if (!touched)
1381
		*error_ret = 1;
1382
	return (timestamp_t)update_tm(&tm, &now, 0);
1383
}
1384

1385
timestamp_t approxidate_careful(const char *date, int *error_ret)
1386
{
1387
	struct timeval tv;
1388
	timestamp_t timestamp;
1389
	int offset;
1390
	int dummy = 0;
1391
	if (!error_ret)
1392
		error_ret = &dummy;
1393

1394
	if (!parse_date_basic(date, &timestamp, &offset)) {
1395
		*error_ret = 0;
1396
		return timestamp;
1397
	}
1398

1399
	get_time(&tv);
1400
	return approxidate_str(date, &tv, error_ret);
1401
}
1402

1403
int date_overflows(timestamp_t t)
1404
{
1405
	time_t sys;
1406

1407
	/* If we overflowed our timestamp data type, that's bad... */
1408
	if ((uintmax_t)t >= TIME_MAX)
1409
		return 1;
1410

1411
	/*
1412
	 * ...but we also are going to feed the result to system
1413
	 * functions that expect time_t, which is often "signed long".
1414
	 * Make sure that we fit into time_t, as well.
1415
	 */
1416
	sys = t;
1417
	return t != sys || (t < 1) != (sys < 1);
1418
}
1419