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