about summary refs log tree commit diff
path: root/third_party/git/builtin/describe.c
blob: 420f4c6401b6204bb422325ed0c08d713b2dfcda (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
#define USE_THE_INDEX_COMPATIBILITY_MACROS
#include "cache.h"
#include "config.h"
#include "lockfile.h"
#include "commit.h"
#include "tag.h"
#include "blob.h"
#include "refs.h"
#include "builtin.h"
#include "exec-cmd.h"
#include "parse-options.h"
#include "revision.h"
#include "diff.h"
#include "hashmap.h"
#include "argv-array.h"
#include "run-command.h"
#include "object-store.h"
#include "list-objects.h"
#include "commit-slab.h"

#define MAX_TAGS	(FLAG_BITS - 1)

define_commit_slab(commit_names, struct commit_name *);

static const char * const describe_usage[] = {
	N_("git describe [<options>] [<commit-ish>...]"),
	N_("git describe [<options>] --dirty"),
	NULL
};

static int debug;	/* Display lots of verbose info */
static int all;	/* Any valid ref can be used */
static int tags;	/* Allow lightweight tags */
static int longformat;
static int first_parent;
static int abbrev = -1; /* unspecified */
static int max_candidates = 10;
static struct hashmap names;
static int have_util;
static struct string_list patterns = STRING_LIST_INIT_NODUP;
static struct string_list exclude_patterns = STRING_LIST_INIT_NODUP;
static int always;
static const char *suffix, *dirty, *broken;
static struct commit_names commit_names;

/* diff-index command arguments to check if working tree is dirty. */
static const char *diff_index_args[] = {
	"diff-index", "--quiet", "HEAD", "--", NULL
};

struct commit_name {
	struct hashmap_entry entry;
	struct object_id peeled;
	struct tag *tag;
	unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
	unsigned name_checked:1;
	struct object_id oid;
	char *path;
};

static const char *prio_names[] = {
	N_("head"), N_("lightweight"), N_("annotated"),
};

static int commit_name_neq(const void *unused_cmp_data,
			   const struct hashmap_entry *eptr,
			   const struct hashmap_entry *entry_or_key,
			   const void *peeled)
{
	const struct commit_name *cn1, *cn2;

	cn1 = container_of(eptr, const struct commit_name, entry);
	cn2 = container_of(entry_or_key, const struct commit_name, entry);

	return !oideq(&cn1->peeled, peeled ? peeled : &cn2->peeled);
}

static inline struct commit_name *find_commit_name(const struct object_id *peeled)
{
	return hashmap_get_entry_from_hash(&names, oidhash(peeled), peeled,
						struct commit_name, entry);
}

static int replace_name(struct commit_name *e,
			       int prio,
			       const struct object_id *oid,
			       struct tag **tag)
{
	if (!e || e->prio < prio)
		return 1;

	if (e->prio == 2 && prio == 2) {
		/* Multiple annotated tags point to the same commit.
		 * Select one to keep based upon their tagger date.
		 */
		struct tag *t;

		if (!e->tag) {
			t = lookup_tag(the_repository, &e->oid);
			if (!t || parse_tag(t))
				return 1;
			e->tag = t;
		}

		t = lookup_tag(the_repository, oid);
		if (!t || parse_tag(t))
			return 0;
		*tag = t;

		if (e->tag->date < t->date)
			return 1;
	}

	return 0;
}

static void add_to_known_names(const char *path,
			       const struct object_id *peeled,
			       int prio,
			       const struct object_id *oid)
{
	struct commit_name *e = find_commit_name(peeled);
	struct tag *tag = NULL;
	if (replace_name(e, prio, oid, &tag)) {
		if (!e) {
			e = xmalloc(sizeof(struct commit_name));
			oidcpy(&e->peeled, peeled);
			hashmap_entry_init(&e->entry, oidhash(peeled));
			hashmap_add(&names, &e->entry);
			e->path = NULL;
		}
		e->tag = tag;
		e->prio = prio;
		e->name_checked = 0;
		oidcpy(&e->oid, oid);
		free(e->path);
		e->path = xstrdup(path);
	}
}

static int get_name(const char *path, const struct object_id *oid, int flag, void *cb_data)
{
	int is_tag = 0;
	struct object_id peeled;
	int is_annotated, prio;
	const char *path_to_match = NULL;

	if (skip_prefix(path, "refs/tags/", &path_to_match)) {
		is_tag = 1;
	} else if (all) {
		if ((exclude_patterns.nr || patterns.nr) &&
		    !skip_prefix(path, "refs/heads/", &path_to_match) &&
		    !skip_prefix(path, "refs/remotes/", &path_to_match)) {
			/* Only accept reference of known type if there are match/exclude patterns */
			return 0;
		}
	} else {
		/* Reject anything outside refs/tags/ unless --all */
		return 0;
	}

	/*
	 * If we're given exclude patterns, first exclude any tag which match
	 * any of the exclude pattern.
	 */
	if (exclude_patterns.nr) {
		struct string_list_item *item;

		for_each_string_list_item(item, &exclude_patterns) {
			if (!wildmatch(item->string, path_to_match, 0))
				return 0;
		}
	}

	/*
	 * If we're given patterns, accept only tags which match at least one
	 * pattern.
	 */
	if (patterns.nr) {
		int found = 0;
		struct string_list_item *item;

		for_each_string_list_item(item, &patterns) {
			if (!wildmatch(item->string, path_to_match, 0)) {
				found = 1;
				break;
			}
		}

		if (!found)
			return 0;
	}

	/* Is it annotated? */
	if (!peel_ref(path, &peeled)) {
		is_annotated = !oideq(oid, &peeled);
	} else {
		oidcpy(&peeled, oid);
		is_annotated = 0;
	}

	/*
	 * By default, we only use annotated tags, but with --tags
	 * we fall back to lightweight ones (even without --tags,
	 * we still remember lightweight ones, only to give hints
	 * in an error message).  --all allows any refs to be used.
	 */
	if (is_annotated)
		prio = 2;
	else if (is_tag)
		prio = 1;
	else
		prio = 0;

	add_to_known_names(all ? path + 5 : path + 10, &peeled, prio, oid);
	return 0;
}

struct possible_tag {
	struct commit_name *name;
	int depth;
	int found_order;
	unsigned flag_within;
};

static int compare_pt(const void *a_, const void *b_)
{
	struct possible_tag *a = (struct possible_tag *)a_;
	struct possible_tag *b = (struct possible_tag *)b_;
	if (a->depth != b->depth)
		return a->depth - b->depth;
	if (a->found_order != b->found_order)
		return a->found_order - b->found_order;
	return 0;
}

static unsigned long finish_depth_computation(
	struct commit_list **list,
	struct possible_tag *best)
{
	unsigned long seen_commits = 0;
	while (*list) {
		struct commit *c = pop_commit(list);
		struct commit_list *parents = c->parents;
		seen_commits++;
		if (c->object.flags & best->flag_within) {
			struct commit_list *a = *list;
			while (a) {
				struct commit *i = a->item;
				if (!(i->object.flags & best->flag_within))
					break;
				a = a->next;
			}
			if (!a)
				break;
		} else
			best->depth++;
		while (parents) {
			struct commit *p = parents->item;
			parse_commit(p);
			if (!(p->object.flags & SEEN))
				commit_list_insert_by_date(p, list);
			p->object.flags |= c->object.flags;
			parents = parents->next;
		}
	}
	return seen_commits;
}

static void append_name(struct commit_name *n, struct strbuf *dst)
{
	if (n->prio == 2 && !n->tag) {
		n->tag = lookup_tag(the_repository, &n->oid);
		if (!n->tag || parse_tag(n->tag))
			die(_("annotated tag %s not available"), n->path);
	}
	if (n->tag && !n->name_checked) {
		if (!n->tag->tag)
			die(_("annotated tag %s has no embedded name"), n->path);
		if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
			warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
		n->name_checked = 1;
	}

	if (n->tag) {
		if (all)
			strbuf_addstr(dst, "tags/");
		strbuf_addstr(dst, n->tag->tag);
	} else {
		strbuf_addstr(dst, n->path);
	}
}

static void append_suffix(int depth, const struct object_id *oid, struct strbuf *dst)
{
	strbuf_addf(dst, "-%d-g%s", depth, find_unique_abbrev(oid, abbrev));
}

static void describe_commit(struct object_id *oid, struct strbuf *dst)
{
	struct commit *cmit, *gave_up_on = NULL;
	struct commit_list *list;
	struct commit_name *n;
	struct possible_tag all_matches[MAX_TAGS];
	unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
	unsigned long seen_commits = 0;
	unsigned int unannotated_cnt = 0;

	cmit = lookup_commit_reference(the_repository, oid);

	n = find_commit_name(&cmit->object.oid);
	if (n && (tags || all || n->prio == 2)) {
		/*
		 * Exact match to an existing ref.
		 */
		append_name(n, dst);
		if (longformat)
			append_suffix(0, n->tag ? get_tagged_oid(n->tag) : oid, dst);
		if (suffix)
			strbuf_addstr(dst, suffix);
		return;
	}

	if (!max_candidates)
		die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));
	if (debug)
		fprintf(stderr, _("No exact match on refs or tags, searching to describe\n"));

	if (!have_util) {
		struct hashmap_iter iter;
		struct commit *c;
		struct commit_name *n;

		init_commit_names(&commit_names);
		hashmap_for_each_entry(&names, &iter, n,
					entry /* member name */) {
			c = lookup_commit_reference_gently(the_repository,
							   &n->peeled, 1);
			if (c)
				*commit_names_at(&commit_names, c) = n;
		}
		have_util = 1;
	}

	list = NULL;
	cmit->object.flags = SEEN;
	commit_list_insert(cmit, &list);
	while (list) {
		struct commit *c = pop_commit(&list);
		struct commit_list *parents = c->parents;
		struct commit_name **slot;

		seen_commits++;
		slot = commit_names_peek(&commit_names, c);
		n = slot ? *slot : NULL;
		if (n) {
			if (!tags && !all && n->prio < 2) {
				unannotated_cnt++;
			} else if (match_cnt < max_candidates) {
				struct possible_tag *t = &all_matches[match_cnt++];
				t->name = n;
				t->depth = seen_commits - 1;
				t->flag_within = 1u << match_cnt;
				t->found_order = match_cnt;
				c->object.flags |= t->flag_within;
				if (n->prio == 2)
					annotated_cnt++;
			}
			else {
				gave_up_on = c;
				break;
			}
		}
		for (cur_match = 0; cur_match < match_cnt; cur_match++) {
			struct possible_tag *t = &all_matches[cur_match];
			if (!(c->object.flags & t->flag_within))
				t->depth++;
		}
		/* Stop if last remaining path already covered by best candidate(s) */
		if (annotated_cnt && !list) {
			int best_depth = INT_MAX;
			unsigned best_within = 0;
			for (cur_match = 0; cur_match < match_cnt; cur_match++) {
				struct possible_tag *t = &all_matches[cur_match];
				if (t->depth < best_depth) {
					best_depth = t->depth;
					best_within = t->flag_within;
				} else if (t->depth == best_depth) {
					best_within |= t->flag_within;
				}
			}
			if ((c->object.flags & best_within) == best_within) {
				if (debug)
					fprintf(stderr, _("finished search at %s\n"),
						oid_to_hex(&c->object.oid));
				break;
			}
		}
		while (parents) {
			struct commit *p = parents->item;
			parse_commit(p);
			if (!(p->object.flags & SEEN))
				commit_list_insert_by_date(p, &list);
			p->object.flags |= c->object.flags;
			parents = parents->next;

			if (first_parent)
				break;
		}
	}

	if (!match_cnt) {
		struct object_id *cmit_oid = &cmit->object.oid;
		if (always) {
			strbuf_add_unique_abbrev(dst, cmit_oid, abbrev);
			if (suffix)
				strbuf_addstr(dst, suffix);
			return;
		}
		if (unannotated_cnt)
			die(_("No annotated tags can describe '%s'.\n"
			    "However, there were unannotated tags: try --tags."),
			    oid_to_hex(cmit_oid));
		else
			die(_("No tags can describe '%s'.\n"
			    "Try --always, or create some tags."),
			    oid_to_hex(cmit_oid));
	}

	QSORT(all_matches, match_cnt, compare_pt);

	if (gave_up_on) {
		commit_list_insert_by_date(gave_up_on, &list);
		seen_commits--;
	}
	seen_commits += finish_depth_computation(&list, &all_matches[0]);
	free_commit_list(list);

	if (debug) {
		static int label_width = -1;
		if (label_width < 0) {
			int i, w;
			for (i = 0; i < ARRAY_SIZE(prio_names); i++) {
				w = strlen(_(prio_names[i]));
				if (label_width < w)
					label_width = w;
			}
		}
		for (cur_match = 0; cur_match < match_cnt; cur_match++) {
			struct possible_tag *t = &all_matches[cur_match];
			fprintf(stderr, " %-*s %8d %s\n",
				label_width, _(prio_names[t->name->prio]),
				t->depth, t->name->path);
		}
		fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
		if (gave_up_on) {
			fprintf(stderr,
				_("more than %i tags found; listed %i most recent\n"
				"gave up search at %s\n"),
				max_candidates, max_candidates,
				oid_to_hex(&gave_up_on->object.oid));
		}
	}

	append_name(all_matches[0].name, dst);
	if (abbrev)
		append_suffix(all_matches[0].depth, &cmit->object.oid, dst);
	if (suffix)
		strbuf_addstr(dst, suffix);
}

struct process_commit_data {
	struct object_id current_commit;
	struct object_id looking_for;
	struct strbuf *dst;
	struct rev_info *revs;
};

static void process_commit(struct commit *commit, void *data)
{
	struct process_commit_data *pcd = data;
	pcd->current_commit = commit->object.oid;
}

static void process_object(struct object *obj, const char *path, void *data)
{
	struct process_commit_data *pcd = data;

	if (oideq(&pcd->looking_for, &obj->oid) && !pcd->dst->len) {
		reset_revision_walk();
		describe_commit(&pcd->current_commit, pcd->dst);
		strbuf_addf(pcd->dst, ":%s", path);
		free_commit_list(pcd->revs->commits);
		pcd->revs->commits = NULL;
	}
}

static void describe_blob(struct object_id oid, struct strbuf *dst)
{
	struct rev_info revs;
	struct argv_array args = ARGV_ARRAY_INIT;
	struct process_commit_data pcd = { null_oid, oid, dst, &revs};

	argv_array_pushl(&args, "internal: The first arg is not parsed",
		"--objects", "--in-commit-order", "--reverse", "HEAD",
		NULL);

	repo_init_revisions(the_repository, &revs, NULL);
	if (setup_revisions(args.argc, args.argv, &revs, NULL) > 1)
		BUG("setup_revisions could not handle all args?");

	if (prepare_revision_walk(&revs))
		die("revision walk setup failed");

	traverse_commit_list(&revs, process_commit, process_object, &pcd);
	reset_revision_walk();
}

static void describe(const char *arg, int last_one)
{
	struct object_id oid;
	struct commit *cmit;
	struct strbuf sb = STRBUF_INIT;

	if (debug)
		fprintf(stderr, _("describe %s\n"), arg);

	if (get_oid(arg, &oid))
		die(_("Not a valid object name %s"), arg);
	cmit = lookup_commit_reference_gently(the_repository, &oid, 1);

	if (cmit)
		describe_commit(&oid, &sb);
	else if (oid_object_info(the_repository, &oid, NULL) == OBJ_BLOB)
		describe_blob(oid, &sb);
	else
		die(_("%s is neither a commit nor blob"), arg);

	puts(sb.buf);

	if (!last_one)
		clear_commit_marks(cmit, -1);

	strbuf_release(&sb);
}

int cmd_describe(int argc, const char **argv, const char *prefix)
{
	int contains = 0;
	struct option options[] = {
		OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
		OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
		OPT_BOOL(0, "all",        &all, N_("use any ref")),
		OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
		OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
		OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
		OPT__ABBREV(&abbrev),
		OPT_SET_INT(0, "exact-match", &max_candidates,
			    N_("only output exact matches"), 0),
		OPT_INTEGER(0, "candidates", &max_candidates,
			    N_("consider <n> most recent tags (default: 10)")),
		OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),
			   N_("only consider tags matching <pattern>")),
		OPT_STRING_LIST(0, "exclude", &exclude_patterns, N_("pattern"),
			   N_("do not consider tags matching <pattern>")),
		OPT_BOOL(0, "always",        &always,
			N_("show abbreviated commit object as fallback")),
		{OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
			N_("append <mark> on dirty working tree (default: \"-dirty\")"),
			PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
		{OPTION_STRING, 0, "broken",  &broken, N_("mark"),
			N_("append <mark> on broken working tree (default: \"-broken\")"),
			PARSE_OPT_OPTARG, NULL, (intptr_t) "-broken"},
		OPT_END(),
	};

	git_config(git_default_config, NULL);
	argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
	if (abbrev < 0)
		abbrev = DEFAULT_ABBREV;

	if (max_candidates < 0)
		max_candidates = 0;
	else if (max_candidates > MAX_TAGS)
		max_candidates = MAX_TAGS;

	save_commit_buffer = 0;

	if (longformat && abbrev == 0)
		die(_("--long is incompatible with --abbrev=0"));

	if (contains) {
		struct string_list_item *item;
		struct argv_array args;

		argv_array_init(&args);
		argv_array_pushl(&args, "name-rev",
				 "--peel-tag", "--name-only", "--no-undefined",
				 NULL);
		if (always)
			argv_array_push(&args, "--always");
		if (!all) {
			argv_array_push(&args, "--tags");
			for_each_string_list_item(item, &patterns)
				argv_array_pushf(&args, "--refs=refs/tags/%s", item->string);
			for_each_string_list_item(item, &exclude_patterns)
				argv_array_pushf(&args, "--exclude=refs/tags/%s", item->string);
		}
		if (argc)
			argv_array_pushv(&args, argv);
		else
			argv_array_push(&args, "HEAD");
		return cmd_name_rev(args.argc, args.argv, prefix);
	}

	hashmap_init(&names, commit_name_neq, NULL, 0);
	for_each_rawref(get_name, NULL);
	if (!hashmap_get_size(&names) && !always)
		die(_("No names found, cannot describe anything."));

	if (argc == 0) {
		if (broken) {
			struct child_process cp = CHILD_PROCESS_INIT;
			argv_array_pushv(&cp.args, diff_index_args);
			cp.git_cmd = 1;
			cp.no_stdin = 1;
			cp.no_stdout = 1;

			if (!dirty)
				dirty = "-dirty";

			switch (run_command(&cp)) {
			case 0:
				suffix = NULL;
				break;
			case 1:
				suffix = dirty;
				break;
			default:
				/* diff-index aborted abnormally */
				suffix = broken;
			}
		} else if (dirty) {
			struct lock_file index_lock = LOCK_INIT;
			struct rev_info revs;
			struct argv_array args = ARGV_ARRAY_INIT;
			int fd, result;

			setup_work_tree();
			read_cache();
			refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
				      NULL, NULL, NULL);
			fd = hold_locked_index(&index_lock, 0);
			if (0 <= fd)
				repo_update_index_if_able(the_repository, &index_lock);

			repo_init_revisions(the_repository, &revs, prefix);
			argv_array_pushv(&args, diff_index_args);
			if (setup_revisions(args.argc, args.argv, &revs, NULL) != 1)
				BUG("malformed internal diff-index command line");
			result = run_diff_index(&revs, 0);

			if (!diff_result_code(&revs.diffopt, result))
				suffix = NULL;
			else
				suffix = dirty;
		}
		describe("HEAD", 1);
	} else if (dirty) {
		die(_("--dirty is incompatible with commit-ishes"));
	} else if (broken) {
		die(_("--broken is incompatible with commit-ishes"));
	} else {
		while (argc-- > 0)
			describe(*argv++, argc == 0);
	}
	return 0;
}