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