Merge branch 'bp/test-drop-caches-for-windows'
[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 "revision.h"
12 #include "diff.h"
13 #include "hashmap.h"
14 #include "argv-array.h"
15 #include "run-command.h"
16 #include "object-store.h"
17 #include "revision.h"
18 #include "list-objects.h"
19 #include "commit-slab.h"
20
21 #define MAX_TAGS        (FLAG_BITS - 1)
22
23 define_commit_slab(commit_names, struct commit_name *);
24
25 static const char * const describe_usage[] = {
26         N_("git describe [<options>] [<commit-ish>...]"),
27         N_("git describe [<options>] --dirty"),
28         NULL
29 };
30
31 static int debug;       /* Display lots of verbose info */
32 static int all; /* Any valid ref can be used */
33 static int tags;        /* Allow lightweight tags */
34 static int longformat;
35 static int first_parent;
36 static int abbrev = -1; /* unspecified */
37 static int max_candidates = 10;
38 static struct hashmap names;
39 static int have_util;
40 static struct string_list patterns = STRING_LIST_INIT_NODUP;
41 static struct string_list exclude_patterns = STRING_LIST_INIT_NODUP;
42 static int always;
43 static const char *suffix, *dirty, *broken;
44 static struct commit_names commit_names;
45
46 /* diff-index command arguments to check if working tree is dirty. */
47 static const char *diff_index_args[] = {
48         "diff-index", "--quiet", "HEAD", "--", NULL
49 };
50
51 struct commit_name {
52         struct hashmap_entry entry;
53         struct object_id peeled;
54         struct tag *tag;
55         unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
56         unsigned name_checked:1;
57         struct object_id oid;
58         char *path;
59 };
60
61 static const char *prio_names[] = {
62         N_("head"), N_("lightweight"), N_("annotated"),
63 };
64
65 static int commit_name_cmp(const void *unused_cmp_data,
66                            const void *entry,
67                            const void *entry_or_key,
68                            const void *peeled)
69 {
70         const struct commit_name *cn1 = entry;
71         const struct commit_name *cn2 = entry_or_key;
72
73         return oidcmp(&cn1->peeled, peeled ? peeled : &cn2->peeled);
74 }
75
76 static inline struct commit_name *find_commit_name(const struct object_id *peeled)
77 {
78         return hashmap_get_from_hash(&names, sha1hash(peeled->hash), peeled->hash);
79 }
80
81 static int replace_name(struct commit_name *e,
82                                int prio,
83                                const struct object_id *oid,
84                                struct tag **tag)
85 {
86         if (!e || e->prio < prio)
87                 return 1;
88
89         if (e->prio == 2 && prio == 2) {
90                 /* Multiple annotated tags point to the same commit.
91                  * Select one to keep based upon their tagger date.
92                  */
93                 struct tag *t;
94
95                 if (!e->tag) {
96                         t = lookup_tag(&e->oid);
97                         if (!t || parse_tag(t))
98                                 return 1;
99                         e->tag = t;
100                 }
101
102                 t = lookup_tag(oid);
103                 if (!t || parse_tag(t))
104                         return 0;
105                 *tag = t;
106
107                 if (e->tag->date < t->date)
108                         return 1;
109         }
110
111         return 0;
112 }
113
114 static void add_to_known_names(const char *path,
115                                const struct object_id *peeled,
116                                int prio,
117                                const struct object_id *oid)
118 {
119         struct commit_name *e = find_commit_name(peeled);
120         struct tag *tag = NULL;
121         if (replace_name(e, prio, oid, &tag)) {
122                 if (!e) {
123                         e = xmalloc(sizeof(struct commit_name));
124                         oidcpy(&e->peeled, peeled);
125                         hashmap_entry_init(e, sha1hash(peeled->hash));
126                         hashmap_add(&names, e);
127                         e->path = NULL;
128                 }
129                 e->tag = tag;
130                 e->prio = prio;
131                 e->name_checked = 0;
132                 oidcpy(&e->oid, oid);
133                 free(e->path);
134                 e->path = xstrdup(path);
135         }
136 }
137
138 static int get_name(const char *path, const struct object_id *oid, int flag, void *cb_data)
139 {
140         int is_tag = 0;
141         struct object_id peeled;
142         int is_annotated, prio;
143         const char *path_to_match = NULL;
144
145         if (skip_prefix(path, "refs/tags/", &path_to_match)) {
146                 is_tag = 1;
147         } else if (all) {
148                 if ((exclude_patterns.nr || patterns.nr) &&
149                     !skip_prefix(path, "refs/heads/", &path_to_match) &&
150                     !skip_prefix(path, "refs/remotes/", &path_to_match)) {
151                         /* Only accept reference of known type if there are match/exclude patterns */
152                         return 0;
153                 }
154         } else {
155                 /* Reject anything outside refs/tags/ unless --all */
156                 return 0;
157         }
158
159         /*
160          * If we're given exclude patterns, first exclude any tag which match
161          * any of the exclude pattern.
162          */
163         if (exclude_patterns.nr) {
164                 struct string_list_item *item;
165
166                 for_each_string_list_item(item, &exclude_patterns) {
167                         if (!wildmatch(item->string, path_to_match, 0))
168                                 return 0;
169                 }
170         }
171
172         /*
173          * If we're given patterns, accept only tags which match at least one
174          * pattern.
175          */
176         if (patterns.nr) {
177                 int found = 0;
178                 struct string_list_item *item;
179
180                 for_each_string_list_item(item, &patterns) {
181                         if (!wildmatch(item->string, path_to_match, 0)) {
182                                 found = 1;
183                                 break;
184                         }
185                 }
186
187                 if (!found)
188                         return 0;
189         }
190
191         /* Is it annotated? */
192         if (!peel_ref(path, &peeled)) {
193                 is_annotated = !!oidcmp(oid, &peeled);
194         } else {
195                 oidcpy(&peeled, oid);
196                 is_annotated = 0;
197         }
198
199         /*
200          * By default, we only use annotated tags, but with --tags
201          * we fall back to lightweight ones (even without --tags,
202          * we still remember lightweight ones, only to give hints
203          * in an error message).  --all allows any refs to be used.
204          */
205         if (is_annotated)
206                 prio = 2;
207         else if (is_tag)
208                 prio = 1;
209         else
210                 prio = 0;
211
212         add_to_known_names(all ? path + 5 : path + 10, &peeled, prio, oid);
213         return 0;
214 }
215
216 struct possible_tag {
217         struct commit_name *name;
218         int depth;
219         int found_order;
220         unsigned flag_within;
221 };
222
223 static int compare_pt(const void *a_, const void *b_)
224 {
225         struct possible_tag *a = (struct possible_tag *)a_;
226         struct possible_tag *b = (struct possible_tag *)b_;
227         if (a->depth != b->depth)
228                 return a->depth - b->depth;
229         if (a->found_order != b->found_order)
230                 return a->found_order - b->found_order;
231         return 0;
232 }
233
234 static unsigned long finish_depth_computation(
235         struct commit_list **list,
236         struct possible_tag *best)
237 {
238         unsigned long seen_commits = 0;
239         while (*list) {
240                 struct commit *c = pop_commit(list);
241                 struct commit_list *parents = c->parents;
242                 seen_commits++;
243                 if (c->object.flags & best->flag_within) {
244                         struct commit_list *a = *list;
245                         while (a) {
246                                 struct commit *i = a->item;
247                                 if (!(i->object.flags & best->flag_within))
248                                         break;
249                                 a = a->next;
250                         }
251                         if (!a)
252                                 break;
253                 } else
254                         best->depth++;
255                 while (parents) {
256                         struct commit *p = parents->item;
257                         parse_commit(p);
258                         if (!(p->object.flags & SEEN))
259                                 commit_list_insert_by_date(p, list);
260                         p->object.flags |= c->object.flags;
261                         parents = parents->next;
262                 }
263         }
264         return seen_commits;
265 }
266
267 static void append_name(struct commit_name *n, struct strbuf *dst)
268 {
269         if (n->prio == 2 && !n->tag) {
270                 n->tag = lookup_tag(&n->oid);
271                 if (!n->tag || parse_tag(n->tag))
272                         die(_("annotated tag %s not available"), n->path);
273         }
274         if (n->tag && !n->name_checked) {
275                 if (!n->tag->tag)
276                         die(_("annotated tag %s has no embedded name"), n->path);
277                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
278                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
279                 n->name_checked = 1;
280         }
281
282         if (n->tag) {
283                 if (all)
284                         strbuf_addstr(dst, "tags/");
285                 strbuf_addstr(dst, n->tag->tag);
286         } else {
287                 strbuf_addstr(dst, n->path);
288         }
289 }
290
291 static void append_suffix(int depth, const struct object_id *oid, struct strbuf *dst)
292 {
293         strbuf_addf(dst, "-%d-g%s", depth, find_unique_abbrev(oid, abbrev));
294 }
295
296 static void describe_commit(struct object_id *oid, struct strbuf *dst)
297 {
298         struct commit *cmit, *gave_up_on = NULL;
299         struct commit_list *list;
300         struct commit_name *n;
301         struct possible_tag all_matches[MAX_TAGS];
302         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
303         unsigned long seen_commits = 0;
304         unsigned int unannotated_cnt = 0;
305
306         cmit = lookup_commit_reference(oid);
307
308         n = find_commit_name(&cmit->object.oid);
309         if (n && (tags || all || n->prio == 2)) {
310                 /*
311                  * Exact match to an existing ref.
312                  */
313                 append_name(n, dst);
314                 if (longformat)
315                         append_suffix(0, n->tag ? &n->tag->tagged->oid : oid, dst);
316                 if (suffix)
317                         strbuf_addstr(dst, suffix);
318                 return;
319         }
320
321         if (!max_candidates)
322                 die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));
323         if (debug)
324                 fprintf(stderr, _("No exact match on refs or tags, searching to describe\n"));
325
326         if (!have_util) {
327                 struct hashmap_iter iter;
328                 struct commit *c;
329                 struct commit_name *n;
330
331                 init_commit_names(&commit_names);
332                 n = hashmap_iter_first(&names, &iter);
333                 for (; n; n = hashmap_iter_next(&iter)) {
334                         c = lookup_commit_reference_gently(&n->peeled, 1);
335                         if (c)
336                                 *commit_names_at(&commit_names, c) = n;
337                 }
338                 have_util = 1;
339         }
340
341         list = NULL;
342         cmit->object.flags = SEEN;
343         commit_list_insert(cmit, &list);
344         while (list) {
345                 struct commit *c = pop_commit(&list);
346                 struct commit_list *parents = c->parents;
347                 struct commit_name **slot;
348
349                 seen_commits++;
350                 slot = commit_names_peek(&commit_names, c);
351                 n = slot ? *slot : NULL;
352                 if (n) {
353                         if (!tags && !all && n->prio < 2) {
354                                 unannotated_cnt++;
355                         } else if (match_cnt < max_candidates) {
356                                 struct possible_tag *t = &all_matches[match_cnt++];
357                                 t->name = n;
358                                 t->depth = seen_commits - 1;
359                                 t->flag_within = 1u << match_cnt;
360                                 t->found_order = match_cnt;
361                                 c->object.flags |= t->flag_within;
362                                 if (n->prio == 2)
363                                         annotated_cnt++;
364                         }
365                         else {
366                                 gave_up_on = c;
367                                 break;
368                         }
369                 }
370                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
371                         struct possible_tag *t = &all_matches[cur_match];
372                         if (!(c->object.flags & t->flag_within))
373                                 t->depth++;
374                 }
375                 if (annotated_cnt && !list) {
376                         if (debug)
377                                 fprintf(stderr, _("finished search at %s\n"),
378                                         oid_to_hex(&c->object.oid));
379                         break;
380                 }
381                 while (parents) {
382                         struct commit *p = parents->item;
383                         parse_commit(p);
384                         if (!(p->object.flags & SEEN))
385                                 commit_list_insert_by_date(p, &list);
386                         p->object.flags |= c->object.flags;
387                         parents = parents->next;
388
389                         if (first_parent)
390                                 break;
391                 }
392         }
393
394         if (!match_cnt) {
395                 struct object_id *cmit_oid = &cmit->object.oid;
396                 if (always) {
397                         strbuf_add_unique_abbrev(dst, cmit_oid, abbrev);
398                         if (suffix)
399                                 strbuf_addstr(dst, suffix);
400                         return;
401                 }
402                 if (unannotated_cnt)
403                         die(_("No annotated tags can describe '%s'.\n"
404                             "However, there were unannotated tags: try --tags."),
405                             oid_to_hex(cmit_oid));
406                 else
407                         die(_("No tags can describe '%s'.\n"
408                             "Try --always, or create some tags."),
409                             oid_to_hex(cmit_oid));
410         }
411
412         QSORT(all_matches, match_cnt, compare_pt);
413
414         if (gave_up_on) {
415                 commit_list_insert_by_date(gave_up_on, &list);
416                 seen_commits--;
417         }
418         seen_commits += finish_depth_computation(&list, &all_matches[0]);
419         free_commit_list(list);
420
421         if (debug) {
422                 static int label_width = -1;
423                 if (label_width < 0) {
424                         int i, w;
425                         for (i = 0; i < ARRAY_SIZE(prio_names); i++) {
426                                 w = strlen(_(prio_names[i]));
427                                 if (label_width < w)
428                                         label_width = w;
429                         }
430                 }
431                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
432                         struct possible_tag *t = &all_matches[cur_match];
433                         fprintf(stderr, " %-*s %8d %s\n",
434                                 label_width, _(prio_names[t->name->prio]),
435                                 t->depth, t->name->path);
436                 }
437                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
438                 if (gave_up_on) {
439                         fprintf(stderr,
440                                 _("more than %i tags found; listed %i most recent\n"
441                                 "gave up search at %s\n"),
442                                 max_candidates, max_candidates,
443                                 oid_to_hex(&gave_up_on->object.oid));
444                 }
445         }
446
447         append_name(all_matches[0].name, dst);
448         if (abbrev)
449                 append_suffix(all_matches[0].depth, &cmit->object.oid, dst);
450         if (suffix)
451                 strbuf_addstr(dst, suffix);
452 }
453
454 struct process_commit_data {
455         struct object_id current_commit;
456         struct object_id looking_for;
457         struct strbuf *dst;
458         struct rev_info *revs;
459 };
460
461 static void process_commit(struct commit *commit, void *data)
462 {
463         struct process_commit_data *pcd = data;
464         pcd->current_commit = commit->object.oid;
465 }
466
467 static void process_object(struct object *obj, const char *path, void *data)
468 {
469         struct process_commit_data *pcd = data;
470
471         if (!oidcmp(&pcd->looking_for, &obj->oid) && !pcd->dst->len) {
472                 reset_revision_walk();
473                 describe_commit(&pcd->current_commit, pcd->dst);
474                 strbuf_addf(pcd->dst, ":%s", path);
475                 free_commit_list(pcd->revs->commits);
476                 pcd->revs->commits = NULL;
477         }
478 }
479
480 static void describe_blob(struct object_id oid, struct strbuf *dst)
481 {
482         struct rev_info revs;
483         struct argv_array args = ARGV_ARRAY_INIT;
484         struct process_commit_data pcd = { null_oid, oid, dst, &revs};
485
486         argv_array_pushl(&args, "internal: The first arg is not parsed",
487                 "--objects", "--in-commit-order", "--reverse", "HEAD",
488                 NULL);
489
490         init_revisions(&revs, NULL);
491         if (setup_revisions(args.argc, args.argv, &revs, NULL) > 1)
492                 BUG("setup_revisions could not handle all args?");
493
494         if (prepare_revision_walk(&revs))
495                 die("revision walk setup failed");
496
497         traverse_commit_list(&revs, process_commit, process_object, &pcd);
498         reset_revision_walk();
499 }
500
501 static void describe(const char *arg, int last_one)
502 {
503         struct object_id oid;
504         struct commit *cmit;
505         struct strbuf sb = STRBUF_INIT;
506
507         if (debug)
508                 fprintf(stderr, _("describe %s\n"), arg);
509
510         if (get_oid(arg, &oid))
511                 die(_("Not a valid object name %s"), arg);
512         cmit = lookup_commit_reference_gently(&oid, 1);
513
514         if (cmit)
515                 describe_commit(&oid, &sb);
516         else if (oid_object_info(the_repository, &oid, NULL) == OBJ_BLOB)
517                 describe_blob(oid, &sb);
518         else
519                 die(_("%s is neither a commit nor blob"), arg);
520
521         puts(sb.buf);
522
523         if (!last_one)
524                 clear_commit_marks(cmit, -1);
525
526         strbuf_release(&sb);
527 }
528
529 int cmd_describe(int argc, const char **argv, const char *prefix)
530 {
531         int contains = 0;
532         struct option options[] = {
533                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
534                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
535                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
536                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
537                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
538                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
539                 OPT__ABBREV(&abbrev),
540                 OPT_SET_INT(0, "exact-match", &max_candidates,
541                             N_("only output exact matches"), 0),
542                 OPT_INTEGER(0, "candidates", &max_candidates,
543                             N_("consider <n> most recent tags (default: 10)")),
544                 OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),
545                            N_("only consider tags matching <pattern>")),
546                 OPT_STRING_LIST(0, "exclude", &exclude_patterns, N_("pattern"),
547                            N_("do not consider tags matching <pattern>")),
548                 OPT_BOOL(0, "always",        &always,
549                         N_("show abbreviated commit object as fallback")),
550                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
551                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
552                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
553                 {OPTION_STRING, 0, "broken",  &broken, N_("mark"),
554                         N_("append <mark> on broken working tree (default: \"-broken\")"),
555                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-broken"},
556                 OPT_END(),
557         };
558
559         git_config(git_default_config, NULL);
560         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
561         if (abbrev < 0)
562                 abbrev = DEFAULT_ABBREV;
563
564         if (max_candidates < 0)
565                 max_candidates = 0;
566         else if (max_candidates > MAX_TAGS)
567                 max_candidates = MAX_TAGS;
568
569         save_commit_buffer = 0;
570
571         if (longformat && abbrev == 0)
572                 die(_("--long is incompatible with --abbrev=0"));
573
574         if (contains) {
575                 struct string_list_item *item;
576                 struct argv_array args;
577
578                 argv_array_init(&args);
579                 argv_array_pushl(&args, "name-rev",
580                                  "--peel-tag", "--name-only", "--no-undefined",
581                                  NULL);
582                 if (always)
583                         argv_array_push(&args, "--always");
584                 if (!all) {
585                         argv_array_push(&args, "--tags");
586                         for_each_string_list_item(item, &patterns)
587                                 argv_array_pushf(&args, "--refs=refs/tags/%s", item->string);
588                         for_each_string_list_item(item, &exclude_patterns)
589                                 argv_array_pushf(&args, "--exclude=refs/tags/%s", item->string);
590                 }
591                 if (argc)
592                         argv_array_pushv(&args, argv);
593                 else
594                         argv_array_push(&args, "HEAD");
595                 return cmd_name_rev(args.argc, args.argv, prefix);
596         }
597
598         hashmap_init(&names, commit_name_cmp, NULL, 0);
599         for_each_rawref(get_name, NULL);
600         if (!hashmap_get_size(&names) && !always)
601                 die(_("No names found, cannot describe anything."));
602
603         if (argc == 0) {
604                 if (broken) {
605                         struct child_process cp = CHILD_PROCESS_INIT;
606                         argv_array_pushv(&cp.args, diff_index_args);
607                         cp.git_cmd = 1;
608                         cp.no_stdin = 1;
609                         cp.no_stdout = 1;
610
611                         if (!dirty)
612                                 dirty = "-dirty";
613
614                         switch (run_command(&cp)) {
615                         case 0:
616                                 suffix = NULL;
617                                 break;
618                         case 1:
619                                 suffix = dirty;
620                                 break;
621                         default:
622                                 /* diff-index aborted abnormally */
623                                 suffix = broken;
624                         }
625                 } else if (dirty) {
626                         struct lock_file index_lock = LOCK_INIT;
627                         struct rev_info revs;
628                         struct argv_array args = ARGV_ARRAY_INIT;
629                         int fd, result;
630
631                         read_cache_preload(NULL);
632                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
633                                       NULL, NULL, NULL);
634                         fd = hold_locked_index(&index_lock, 0);
635                         if (0 <= fd)
636                                 update_index_if_able(&the_index, &index_lock);
637
638                         init_revisions(&revs, prefix);
639                         argv_array_pushv(&args, diff_index_args);
640                         if (setup_revisions(args.argc, args.argv, &revs, NULL) != 1)
641                                 BUG("malformed internal diff-index command line");
642                         result = run_diff_index(&revs, 0);
643
644                         if (!diff_result_code(&revs.diffopt, result))
645                                 suffix = NULL;
646                         else
647                                 suffix = dirty;
648                 }
649                 describe("HEAD", 1);
650         } else if (dirty) {
651                 die(_("--dirty is incompatible with commit-ishes"));
652         } else if (broken) {
653                 die(_("--broken is incompatible with commit-ishes"));
654         } else {
655                 while (argc-- > 0)
656                         describe(*argv++, argc == 0);
657         }
658         return 0;
659 }