builtin/describe.c: describe a blob
[git/git.git] / builtin / describe.c
1 #include "cache.h"
2 #include "config.h"
3 #include "lockfile.h"
4 #include "commit.h"
5 #include "tag.h"
6 #include "blob.h"
7 #include "refs.h"
8 #include "builtin.h"
9 #include "exec_cmd.h"
10 #include "parse-options.h"
11 #include "diff.h"
12 #include "hashmap.h"
13 #include "argv-array.h"
14 #include "run-command.h"
15 #include "revision.h"
16 #include "list-objects.h"
17
18 #define MAX_TAGS (FLAG_BITS - 1)
19
20 static const char * const describe_usage[] = {
21 N_("git describe [<options>] [<commit-ish>...]"),
22 N_("git describe [<options>] --dirty"),
23 NULL
24 };
25
26 static int debug; /* Display lots of verbose info */
27 static int all; /* Any valid ref can be used */
28 static int tags; /* Allow lightweight tags */
29 static int longformat;
30 static int first_parent;
31 static int abbrev = -1; /* unspecified */
32 static int max_candidates = 10;
33 static struct hashmap names;
34 static int have_util;
35 static struct string_list patterns = STRING_LIST_INIT_NODUP;
36 static struct string_list exclude_patterns = STRING_LIST_INIT_NODUP;
37 static int always;
38 static const char *suffix, *dirty, *broken;
39
40 /* diff-index command arguments to check if working tree is dirty. */
41 static const char *diff_index_args[] = {
42 "diff-index", "--quiet", "HEAD", "--", NULL
43 };
44
45 struct commit_name {
46 struct hashmap_entry entry;
47 struct object_id peeled;
48 struct tag *tag;
49 unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
50 unsigned name_checked:1;
51 struct object_id oid;
52 char *path;
53 };
54
55 static const char *prio_names[] = {
56 N_("head"), N_("lightweight"), N_("annotated"),
57 };
58
59 static int commit_name_cmp(const void *unused_cmp_data,
60 const void *entry,
61 const void *entry_or_key,
62 const void *peeled)
63 {
64 const struct commit_name *cn1 = entry;
65 const struct commit_name *cn2 = entry_or_key;
66
67 return oidcmp(&cn1->peeled, peeled ? peeled : &cn2->peeled);
68 }
69
70 static inline struct commit_name *find_commit_name(const struct object_id *peeled)
71 {
72 return hashmap_get_from_hash(&names, sha1hash(peeled->hash), peeled->hash);
73 }
74
75 static int replace_name(struct commit_name *e,
76 int prio,
77 const struct object_id *oid,
78 struct tag **tag)
79 {
80 if (!e || e->prio < prio)
81 return 1;
82
83 if (e->prio == 2 && prio == 2) {
84 /* Multiple annotated tags point to the same commit.
85 * Select one to keep based upon their tagger date.
86 */
87 struct tag *t;
88
89 if (!e->tag) {
90 t = lookup_tag(&e->oid);
91 if (!t || parse_tag(t))
92 return 1;
93 e->tag = t;
94 }
95
96 t = lookup_tag(oid);
97 if (!t || parse_tag(t))
98 return 0;
99 *tag = t;
100
101 if (e->tag->date < t->date)
102 return 1;
103 }
104
105 return 0;
106 }
107
108 static void add_to_known_names(const char *path,
109 const struct object_id *peeled,
110 int prio,
111 const struct object_id *oid)
112 {
113 struct commit_name *e = find_commit_name(peeled);
114 struct tag *tag = NULL;
115 if (replace_name(e, prio, oid, &tag)) {
116 if (!e) {
117 e = xmalloc(sizeof(struct commit_name));
118 oidcpy(&e->peeled, peeled);
119 hashmap_entry_init(e, sha1hash(peeled->hash));
120 hashmap_add(&names, e);
121 e->path = NULL;
122 }
123 e->tag = tag;
124 e->prio = prio;
125 e->name_checked = 0;
126 oidcpy(&e->oid, oid);
127 free(e->path);
128 e->path = xstrdup(path);
129 }
130 }
131
132 static int get_name(const char *path, const struct object_id *oid, int flag, void *cb_data)
133 {
134 int is_tag = 0;
135 struct object_id peeled;
136 int is_annotated, prio;
137 const char *path_to_match = NULL;
138
139 if (skip_prefix(path, "refs/tags/", &path_to_match)) {
140 is_tag = 1;
141 } else if (all) {
142 if ((exclude_patterns.nr || patterns.nr) &&
143 !skip_prefix(path, "refs/heads/", &path_to_match) &&
144 !skip_prefix(path, "refs/remotes/", &path_to_match)) {
145 /* Only accept reference of known type if there are match/exclude patterns */
146 return 0;
147 }
148 } else {
149 /* Reject anything outside refs/tags/ unless --all */
150 return 0;
151 }
152
153 /*
154 * If we're given exclude patterns, first exclude any tag which match
155 * any of the exclude pattern.
156 */
157 if (exclude_patterns.nr) {
158 struct string_list_item *item;
159
160 for_each_string_list_item(item, &exclude_patterns) {
161 if (!wildmatch(item->string, path_to_match, 0))
162 return 0;
163 }
164 }
165
166 /*
167 * If we're given patterns, accept only tags which match at least one
168 * pattern.
169 */
170 if (patterns.nr) {
171 int found = 0;
172 struct string_list_item *item;
173
174 for_each_string_list_item(item, &patterns) {
175 if (!wildmatch(item->string, path_to_match, 0)) {
176 found = 1;
177 break;
178 }
179 }
180
181 if (!found)
182 return 0;
183 }
184
185 /* Is it annotated? */
186 if (!peel_ref(path, peeled.hash)) {
187 is_annotated = !!oidcmp(oid, &peeled);
188 } else {
189 oidcpy(&peeled, oid);
190 is_annotated = 0;
191 }
192
193 /*
194 * By default, we only use annotated tags, but with --tags
195 * we fall back to lightweight ones (even without --tags,
196 * we still remember lightweight ones, only to give hints
197 * in an error message). --all allows any refs to be used.
198 */
199 if (is_annotated)
200 prio = 2;
201 else if (is_tag)
202 prio = 1;
203 else
204 prio = 0;
205
206 add_to_known_names(all ? path + 5 : path + 10, &peeled, prio, oid);
207 return 0;
208 }
209
210 struct possible_tag {
211 struct commit_name *name;
212 int depth;
213 int found_order;
214 unsigned flag_within;
215 };
216
217 static int compare_pt(const void *a_, const void *b_)
218 {
219 struct possible_tag *a = (struct possible_tag *)a_;
220 struct possible_tag *b = (struct possible_tag *)b_;
221 if (a->depth != b->depth)
222 return a->depth - b->depth;
223 if (a->found_order != b->found_order)
224 return a->found_order - b->found_order;
225 return 0;
226 }
227
228 static unsigned long finish_depth_computation(
229 struct commit_list **list,
230 struct possible_tag *best)
231 {
232 unsigned long seen_commits = 0;
233 while (*list) {
234 struct commit *c = pop_commit(list);
235 struct commit_list *parents = c->parents;
236 seen_commits++;
237 if (c->object.flags & best->flag_within) {
238 struct commit_list *a = *list;
239 while (a) {
240 struct commit *i = a->item;
241 if (!(i->object.flags & best->flag_within))
242 break;
243 a = a->next;
244 }
245 if (!a)
246 break;
247 } else
248 best->depth++;
249 while (parents) {
250 struct commit *p = parents->item;
251 parse_commit(p);
252 if (!(p->object.flags & SEEN))
253 commit_list_insert_by_date(p, list);
254 p->object.flags |= c->object.flags;
255 parents = parents->next;
256 }
257 }
258 return seen_commits;
259 }
260
261 static void append_name(struct commit_name *n, struct strbuf *dst)
262 {
263 if (n->prio == 2 && !n->tag) {
264 n->tag = lookup_tag(&n->oid);
265 if (!n->tag || parse_tag(n->tag))
266 die(_("annotated tag %s not available"), n->path);
267 }
268 if (n->tag && !n->name_checked) {
269 if (!n->tag->tag)
270 die(_("annotated tag %s has no embedded name"), n->path);
271 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
272 warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
273 n->name_checked = 1;
274 }
275
276 if (n->tag)
277 strbuf_addstr(dst, n->tag->tag);
278 else
279 strbuf_addstr(dst, n->path);
280 }
281
282 static void append_suffix(int depth, const struct object_id *oid, struct strbuf *dst)
283 {
284 strbuf_addf(dst, "-%d-g%s", depth, find_unique_abbrev(oid->hash, abbrev));
285 }
286
287 static void describe_commit(struct object_id *oid, struct strbuf *dst)
288 {
289 struct commit *cmit, *gave_up_on = NULL;
290 struct commit_list *list;
291 struct commit_name *n;
292 struct possible_tag all_matches[MAX_TAGS];
293 unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
294 unsigned long seen_commits = 0;
295 unsigned int unannotated_cnt = 0;
296
297 cmit = lookup_commit_reference(oid);
298
299 n = find_commit_name(&cmit->object.oid);
300 if (n && (tags || all || n->prio == 2)) {
301 /*
302 * Exact match to an existing ref.
303 */
304 append_name(n, dst);
305 if (longformat)
306 append_suffix(0, n->tag ? &n->tag->tagged->oid : oid, dst);
307 if (suffix)
308 strbuf_addstr(dst, suffix);
309 return;
310 }
311
312 if (!max_candidates)
313 die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));
314 if (debug)
315 fprintf(stderr, _("No exact match on refs or tags, searching to describe\n"));
316
317 if (!have_util) {
318 struct hashmap_iter iter;
319 struct commit *c;
320 struct commit_name *n = hashmap_iter_first(&names, &iter);
321 for (; n; n = hashmap_iter_next(&iter)) {
322 c = lookup_commit_reference_gently(&n->peeled, 1);
323 if (c)
324 c->util = n;
325 }
326 have_util = 1;
327 }
328
329 list = NULL;
330 cmit->object.flags = SEEN;
331 commit_list_insert(cmit, &list);
332 while (list) {
333 struct commit *c = pop_commit(&list);
334 struct commit_list *parents = c->parents;
335 seen_commits++;
336 n = c->util;
337 if (n) {
338 if (!tags && !all && n->prio < 2) {
339 unannotated_cnt++;
340 } else if (match_cnt < max_candidates) {
341 struct possible_tag *t = &all_matches[match_cnt++];
342 t->name = n;
343 t->depth = seen_commits - 1;
344 t->flag_within = 1u << match_cnt;
345 t->found_order = match_cnt;
346 c->object.flags |= t->flag_within;
347 if (n->prio == 2)
348 annotated_cnt++;
349 }
350 else {
351 gave_up_on = c;
352 break;
353 }
354 }
355 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
356 struct possible_tag *t = &all_matches[cur_match];
357 if (!(c->object.flags & t->flag_within))
358 t->depth++;
359 }
360 if (annotated_cnt && !list) {
361 if (debug)
362 fprintf(stderr, _("finished search at %s\n"),
363 oid_to_hex(&c->object.oid));
364 break;
365 }
366 while (parents) {
367 struct commit *p = parents->item;
368 parse_commit(p);
369 if (!(p->object.flags & SEEN))
370 commit_list_insert_by_date(p, &list);
371 p->object.flags |= c->object.flags;
372 parents = parents->next;
373
374 if (first_parent)
375 break;
376 }
377 }
378
379 if (!match_cnt) {
380 struct object_id *cmit_oid = &cmit->object.oid;
381 if (always) {
382 strbuf_addstr(dst, find_unique_abbrev(cmit_oid->hash, abbrev));
383 if (suffix)
384 strbuf_addstr(dst, suffix);
385 return;
386 }
387 if (unannotated_cnt)
388 die(_("No annotated tags can describe '%s'.\n"
389 "However, there were unannotated tags: try --tags."),
390 oid_to_hex(cmit_oid));
391 else
392 die(_("No tags can describe '%s'.\n"
393 "Try --always, or create some tags."),
394 oid_to_hex(cmit_oid));
395 }
396
397 QSORT(all_matches, match_cnt, compare_pt);
398
399 if (gave_up_on) {
400 commit_list_insert_by_date(gave_up_on, &list);
401 seen_commits--;
402 }
403 seen_commits += finish_depth_computation(&list, &all_matches[0]);
404 free_commit_list(list);
405
406 if (debug) {
407 static int label_width = -1;
408 if (label_width < 0) {
409 int i, w;
410 for (i = 0; i < ARRAY_SIZE(prio_names); i++) {
411 w = strlen(_(prio_names[i]));
412 if (label_width < w)
413 label_width = w;
414 }
415 }
416 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
417 struct possible_tag *t = &all_matches[cur_match];
418 fprintf(stderr, " %-*s %8d %s\n",
419 label_width, _(prio_names[t->name->prio]),
420 t->depth, t->name->path);
421 }
422 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
423 if (gave_up_on) {
424 fprintf(stderr,
425 _("more than %i tags found; listed %i most recent\n"
426 "gave up search at %s\n"),
427 max_candidates, max_candidates,
428 oid_to_hex(&gave_up_on->object.oid));
429 }
430 }
431
432 append_name(all_matches[0].name, dst);
433 if (abbrev)
434 append_suffix(all_matches[0].depth, &cmit->object.oid, dst);
435 if (suffix)
436 strbuf_addstr(dst, suffix);
437 }
438
439 struct process_commit_data {
440 struct object_id current_commit;
441 struct object_id looking_for;
442 struct strbuf *dst;
443 struct rev_info *revs;
444 };
445
446 static void process_commit(struct commit *commit, void *data)
447 {
448 struct process_commit_data *pcd = data;
449 pcd->current_commit = commit->object.oid;
450 }
451
452 static void process_object(struct object *obj, const char *path, void *data)
453 {
454 struct process_commit_data *pcd = data;
455
456 if (!oidcmp(&pcd->looking_for, &obj->oid) && !pcd->dst->len) {
457 reset_revision_walk();
458 describe_commit(&pcd->current_commit, pcd->dst);
459 strbuf_addf(pcd->dst, ":%s", path);
460 free_commit_list(pcd->revs->commits);
461 pcd->revs->commits = NULL;
462 }
463 }
464
465 static void describe_blob(struct object_id oid, struct strbuf *dst)
466 {
467 struct rev_info revs;
468 struct argv_array args = ARGV_ARRAY_INIT;
469 struct process_commit_data pcd = { null_oid, oid, dst, &revs};
470
471 argv_array_pushl(&args, "internal: The first arg is not parsed",
472 "--objects", "--in-commit-order", "--reverse", "HEAD",
473 NULL);
474
475 init_revisions(&revs, NULL);
476 if (setup_revisions(args.argc, args.argv, &revs, NULL) > 1)
477 BUG("setup_revisions could not handle all args?");
478
479 if (prepare_revision_walk(&revs))
480 die("revision walk setup failed");
481
482 traverse_commit_list(&revs, process_commit, process_object, &pcd);
483 reset_revision_walk();
484 }
485
486 static void describe(const char *arg, int last_one)
487 {
488 struct object_id oid;
489 struct commit *cmit;
490 struct strbuf sb = STRBUF_INIT;
491
492 if (debug)
493 fprintf(stderr, _("describe %s\n"), arg);
494
495 if (get_oid(arg, &oid))
496 die(_("Not a valid object name %s"), arg);
497 cmit = lookup_commit_reference_gently(&oid, 1);
498
499 if (cmit)
500 describe_commit(&oid, &sb);
501 else if (lookup_blob(&oid))
502 describe_blob(oid, &sb);
503 else
504 die(_("%s is neither a commit nor blob"), arg);
505
506 puts(sb.buf);
507
508 if (!last_one)
509 clear_commit_marks(cmit, -1);
510
511 strbuf_release(&sb);
512 }
513
514 int cmd_describe(int argc, const char **argv, const char *prefix)
515 {
516 int contains = 0;
517 struct option options[] = {
518 OPT_BOOL(0, "contains", &contains, N_("find the tag that comes after the commit")),
519 OPT_BOOL(0, "debug", &debug, N_("debug search strategy on stderr")),
520 OPT_BOOL(0, "all", &all, N_("use any ref")),
521 OPT_BOOL(0, "tags", &tags, N_("use any tag, even unannotated")),
522 OPT_BOOL(0, "long", &longformat, N_("always use long format")),
523 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
524 OPT__ABBREV(&abbrev),
525 OPT_SET_INT(0, "exact-match", &max_candidates,
526 N_("only output exact matches"), 0),
527 OPT_INTEGER(0, "candidates", &max_candidates,
528 N_("consider <n> most recent tags (default: 10)")),
529 OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),
530 N_("only consider tags matching <pattern>")),
531 OPT_STRING_LIST(0, "exclude", &exclude_patterns, N_("pattern"),
532 N_("do not consider tags matching <pattern>")),
533 OPT_BOOL(0, "always", &always,
534 N_("show abbreviated commit object as fallback")),
535 {OPTION_STRING, 0, "dirty", &dirty, N_("mark"),
536 N_("append <mark> on dirty working tree (default: \"-dirty\")"),
537 PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
538 {OPTION_STRING, 0, "broken", &broken, N_("mark"),
539 N_("append <mark> on broken working tree (default: \"-broken\")"),
540 PARSE_OPT_OPTARG, NULL, (intptr_t) "-broken"},
541 OPT_END(),
542 };
543
544 git_config(git_default_config, NULL);
545 argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
546 if (abbrev < 0)
547 abbrev = DEFAULT_ABBREV;
548
549 if (max_candidates < 0)
550 max_candidates = 0;
551 else if (max_candidates > MAX_TAGS)
552 max_candidates = MAX_TAGS;
553
554 save_commit_buffer = 0;
555
556 if (longformat && abbrev == 0)
557 die(_("--long is incompatible with --abbrev=0"));
558
559 if (contains) {
560 struct string_list_item *item;
561 struct argv_array args;
562
563 argv_array_init(&args);
564 argv_array_pushl(&args, "name-rev",
565 "--peel-tag", "--name-only", "--no-undefined",
566 NULL);
567 if (always)
568 argv_array_push(&args, "--always");
569 if (!all) {
570 argv_array_push(&args, "--tags");
571 for_each_string_list_item(item, &patterns)
572 argv_array_pushf(&args, "--refs=refs/tags/%s", item->string);
573 for_each_string_list_item(item, &exclude_patterns)
574 argv_array_pushf(&args, "--exclude=refs/tags/%s", item->string);
575 }
576 if (argc)
577 argv_array_pushv(&args, argv);
578 else
579 argv_array_push(&args, "HEAD");
580 return cmd_name_rev(args.argc, args.argv, prefix);
581 }
582
583 hashmap_init(&names, commit_name_cmp, NULL, 0);
584 for_each_rawref(get_name, NULL);
585 if (!hashmap_get_size(&names) && !always)
586 die(_("No names found, cannot describe anything."));
587
588 if (argc == 0) {
589 if (broken) {
590 struct child_process cp = CHILD_PROCESS_INIT;
591 argv_array_pushv(&cp.args, diff_index_args);
592 cp.git_cmd = 1;
593 cp.no_stdin = 1;
594 cp.no_stdout = 1;
595
596 if (!dirty)
597 dirty = "-dirty";
598
599 switch (run_command(&cp)) {
600 case 0:
601 suffix = NULL;
602 break;
603 case 1:
604 suffix = dirty;
605 break;
606 default:
607 /* diff-index aborted abnormally */
608 suffix = broken;
609 }
610 } else if (dirty) {
611 static struct lock_file index_lock;
612 int fd;
613
614 read_cache_preload(NULL);
615 refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
616 NULL, NULL, NULL);
617 fd = hold_locked_index(&index_lock, 0);
618 if (0 <= fd)
619 update_index_if_able(&the_index, &index_lock);
620
621 if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
622 diff_index_args, prefix))
623 suffix = NULL;
624 else
625 suffix = dirty;
626 }
627 describe("HEAD", 1);
628 } else if (dirty) {
629 die(_("--dirty is incompatible with commit-ishes"));
630 } else if (broken) {
631 die(_("--broken is incompatible with commit-ishes"));
632 } else {
633 while (argc-- > 0)
634 describe(*argv++, argc == 0);
635 }
636 return 0;
637 }