describe --contains: default to HEAD when no commit-ish is given
[git/git.git] / builtin / describe.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "tag.h"
4 #include "refs.h"
5 #include "builtin.h"
6 #include "exec_cmd.h"
7 #include "parse-options.h"
8 #include "diff.h"
9 #include "hashmap.h"
10 #include "argv-array.h"
11
12 #define SEEN (1u << 0)
13 #define MAX_TAGS (FLAG_BITS - 1)
14
15 static const char * const describe_usage[] = {
16 N_("git describe [options] <commit-ish>*"),
17 N_("git describe [options] --dirty"),
18 NULL
19 };
20
21 static int debug; /* Display lots of verbose info */
22 static int all; /* Any valid ref can be used */
23 static int tags; /* Allow lightweight tags */
24 static int longformat;
25 static int first_parent;
26 static int abbrev = -1; /* unspecified */
27 static int max_candidates = 10;
28 static struct hashmap names;
29 static int have_util;
30 static const char *pattern;
31 static int always;
32 static const char *dirty;
33
34 /* diff-index command arguments to check if working tree is dirty. */
35 static const char *diff_index_args[] = {
36 "diff-index", "--quiet", "HEAD", "--", NULL
37 };
38
39 struct commit_name {
40 struct hashmap_entry entry;
41 unsigned char peeled[20];
42 struct tag *tag;
43 unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
44 unsigned name_checked:1;
45 unsigned char sha1[20];
46 char *path;
47 };
48
49 static const char *prio_names[] = {
50 "head", "lightweight", "annotated",
51 };
52
53 static int commit_name_cmp(const struct commit_name *cn1,
54 const struct commit_name *cn2, const void *peeled)
55 {
56 return hashcmp(cn1->peeled, peeled ? peeled : cn2->peeled);
57 }
58
59 static inline unsigned int hash_sha1(const unsigned char *sha1)
60 {
61 unsigned int hash;
62 memcpy(&hash, sha1, sizeof(hash));
63 return hash;
64 }
65
66 static inline struct commit_name *find_commit_name(const unsigned char *peeled)
67 {
68 struct commit_name key;
69 hashmap_entry_init(&key, hash_sha1(peeled));
70 return hashmap_get(&names, &key, peeled);
71 }
72
73 static int replace_name(struct commit_name *e,
74 int prio,
75 const unsigned char *sha1,
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->sha1);
89 if (!t || parse_tag(t))
90 return 1;
91 e->tag = t;
92 }
93
94 t = lookup_tag(sha1);
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 unsigned char *peeled,
108 int prio,
109 const unsigned char *sha1)
110 {
111 struct commit_name *e = find_commit_name(peeled);
112 struct tag *tag = NULL;
113 if (replace_name(e, prio, sha1, &tag)) {
114 if (!e) {
115 e = xmalloc(sizeof(struct commit_name));
116 hashcpy(e->peeled, peeled);
117 hashmap_entry_init(e, hash_sha1(peeled));
118 hashmap_add(&names, e);
119 e->path = NULL;
120 }
121 e->tag = tag;
122 e->prio = prio;
123 e->name_checked = 0;
124 hashcpy(e->sha1, sha1);
125 free(e->path);
126 e->path = xstrdup(path);
127 }
128 }
129
130 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
131 {
132 int is_tag = starts_with(path, "refs/tags/");
133 unsigned char peeled[20];
134 int is_annotated, prio;
135
136 /* Reject anything outside refs/tags/ unless --all */
137 if (!all && !is_tag)
138 return 0;
139
140 /* Accept only tags that match the pattern, if given */
141 if (pattern && (!is_tag || wildmatch(pattern, path + 10, 0, NULL)))
142 return 0;
143
144 /* Is it annotated? */
145 if (!peel_ref(path, peeled)) {
146 is_annotated = !!hashcmp(sha1, peeled);
147 } else {
148 hashcpy(peeled, sha1);
149 is_annotated = 0;
150 }
151
152 /*
153 * By default, we only use annotated tags, but with --tags
154 * we fall back to lightweight ones (even without --tags,
155 * we still remember lightweight ones, only to give hints
156 * in an error message). --all allows any refs to be used.
157 */
158 if (is_annotated)
159 prio = 2;
160 else if (is_tag)
161 prio = 1;
162 else
163 prio = 0;
164
165 add_to_known_names(all ? path + 5 : path + 10, peeled, prio, sha1);
166 return 0;
167 }
168
169 struct possible_tag {
170 struct commit_name *name;
171 int depth;
172 int found_order;
173 unsigned flag_within;
174 };
175
176 static int compare_pt(const void *a_, const void *b_)
177 {
178 struct possible_tag *a = (struct possible_tag *)a_;
179 struct possible_tag *b = (struct possible_tag *)b_;
180 if (a->depth != b->depth)
181 return a->depth - b->depth;
182 if (a->found_order != b->found_order)
183 return a->found_order - b->found_order;
184 return 0;
185 }
186
187 static unsigned long finish_depth_computation(
188 struct commit_list **list,
189 struct possible_tag *best)
190 {
191 unsigned long seen_commits = 0;
192 while (*list) {
193 struct commit *c = pop_commit(list);
194 struct commit_list *parents = c->parents;
195 seen_commits++;
196 if (c->object.flags & best->flag_within) {
197 struct commit_list *a = *list;
198 while (a) {
199 struct commit *i = a->item;
200 if (!(i->object.flags & best->flag_within))
201 break;
202 a = a->next;
203 }
204 if (!a)
205 break;
206 } else
207 best->depth++;
208 while (parents) {
209 struct commit *p = parents->item;
210 parse_commit(p);
211 if (!(p->object.flags & SEEN))
212 commit_list_insert_by_date(p, list);
213 p->object.flags |= c->object.flags;
214 parents = parents->next;
215 }
216 }
217 return seen_commits;
218 }
219
220 static void display_name(struct commit_name *n)
221 {
222 if (n->prio == 2 && !n->tag) {
223 n->tag = lookup_tag(n->sha1);
224 if (!n->tag || parse_tag(n->tag))
225 die(_("annotated tag %s not available"), n->path);
226 }
227 if (n->tag && !n->name_checked) {
228 if (!n->tag->tag)
229 die(_("annotated tag %s has no embedded name"), n->path);
230 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
231 warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
232 n->name_checked = 1;
233 }
234
235 if (n->tag)
236 printf("%s", n->tag->tag);
237 else
238 printf("%s", n->path);
239 }
240
241 static void show_suffix(int depth, const unsigned char *sha1)
242 {
243 printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
244 }
245
246 static void describe(const char *arg, int last_one)
247 {
248 unsigned char sha1[20];
249 struct commit *cmit, *gave_up_on = NULL;
250 struct commit_list *list;
251 struct commit_name *n;
252 struct possible_tag all_matches[MAX_TAGS];
253 unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
254 unsigned long seen_commits = 0;
255 unsigned int unannotated_cnt = 0;
256
257 if (get_sha1(arg, sha1))
258 die(_("Not a valid object name %s"), arg);
259 cmit = lookup_commit_reference(sha1);
260 if (!cmit)
261 die(_("%s is not a valid '%s' object"), arg, commit_type);
262
263 n = find_commit_name(cmit->object.sha1);
264 if (n && (tags || all || n->prio == 2)) {
265 /*
266 * Exact match to an existing ref.
267 */
268 display_name(n);
269 if (longformat)
270 show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
271 if (dirty)
272 printf("%s", dirty);
273 printf("\n");
274 return;
275 }
276
277 if (!max_candidates)
278 die(_("no tag exactly matches '%s'"), sha1_to_hex(cmit->object.sha1));
279 if (debug)
280 fprintf(stderr, _("searching to describe %s\n"), arg);
281
282 if (!have_util) {
283 struct hashmap_iter iter;
284 struct commit *c;
285 struct commit_name *n = hashmap_iter_first(&names, &iter);
286 for (; n; n = hashmap_iter_next(&iter)) {
287 c = lookup_commit_reference_gently(n->peeled, 1);
288 if (c)
289 c->util = n;
290 }
291 have_util = 1;
292 }
293
294 list = NULL;
295 cmit->object.flags = SEEN;
296 commit_list_insert(cmit, &list);
297 while (list) {
298 struct commit *c = pop_commit(&list);
299 struct commit_list *parents = c->parents;
300 seen_commits++;
301 n = c->util;
302 if (n) {
303 if (!tags && !all && n->prio < 2) {
304 unannotated_cnt++;
305 } else if (match_cnt < max_candidates) {
306 struct possible_tag *t = &all_matches[match_cnt++];
307 t->name = n;
308 t->depth = seen_commits - 1;
309 t->flag_within = 1u << match_cnt;
310 t->found_order = match_cnt;
311 c->object.flags |= t->flag_within;
312 if (n->prio == 2)
313 annotated_cnt++;
314 }
315 else {
316 gave_up_on = c;
317 break;
318 }
319 }
320 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
321 struct possible_tag *t = &all_matches[cur_match];
322 if (!(c->object.flags & t->flag_within))
323 t->depth++;
324 }
325 if (annotated_cnt && !list) {
326 if (debug)
327 fprintf(stderr, _("finished search at %s\n"),
328 sha1_to_hex(c->object.sha1));
329 break;
330 }
331 while (parents) {
332 struct commit *p = parents->item;
333 parse_commit(p);
334 if (!(p->object.flags & SEEN))
335 commit_list_insert_by_date(p, &list);
336 p->object.flags |= c->object.flags;
337 parents = parents->next;
338
339 if (first_parent)
340 break;
341 }
342 }
343
344 if (!match_cnt) {
345 const unsigned char *sha1 = cmit->object.sha1;
346 if (always) {
347 printf("%s", find_unique_abbrev(sha1, abbrev));
348 if (dirty)
349 printf("%s", dirty);
350 printf("\n");
351 return;
352 }
353 if (unannotated_cnt)
354 die(_("No annotated tags can describe '%s'.\n"
355 "However, there were unannotated tags: try --tags."),
356 sha1_to_hex(sha1));
357 else
358 die(_("No tags can describe '%s'.\n"
359 "Try --always, or create some tags."),
360 sha1_to_hex(sha1));
361 }
362
363 qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
364
365 if (gave_up_on) {
366 commit_list_insert_by_date(gave_up_on, &list);
367 seen_commits--;
368 }
369 seen_commits += finish_depth_computation(&list, &all_matches[0]);
370 free_commit_list(list);
371
372 if (debug) {
373 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
374 struct possible_tag *t = &all_matches[cur_match];
375 fprintf(stderr, " %-11s %8d %s\n",
376 prio_names[t->name->prio],
377 t->depth, t->name->path);
378 }
379 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
380 if (gave_up_on) {
381 fprintf(stderr,
382 _("more than %i tags found; listed %i most recent\n"
383 "gave up search at %s\n"),
384 max_candidates, max_candidates,
385 sha1_to_hex(gave_up_on->object.sha1));
386 }
387 }
388
389 display_name(all_matches[0].name);
390 if (abbrev)
391 show_suffix(all_matches[0].depth, cmit->object.sha1);
392 if (dirty)
393 printf("%s", dirty);
394 printf("\n");
395
396 if (!last_one)
397 clear_commit_marks(cmit, -1);
398 }
399
400 int cmd_describe(int argc, const char **argv, const char *prefix)
401 {
402 int contains = 0;
403 struct option options[] = {
404 OPT_BOOL(0, "contains", &contains, N_("find the tag that comes after the commit")),
405 OPT_BOOL(0, "debug", &debug, N_("debug search strategy on stderr")),
406 OPT_BOOL(0, "all", &all, N_("use any ref")),
407 OPT_BOOL(0, "tags", &tags, N_("use any tag, even unannotated")),
408 OPT_BOOL(0, "long", &longformat, N_("always use long format")),
409 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
410 OPT__ABBREV(&abbrev),
411 OPT_SET_INT(0, "exact-match", &max_candidates,
412 N_("only output exact matches"), 0),
413 OPT_INTEGER(0, "candidates", &max_candidates,
414 N_("consider <n> most recent tags (default: 10)")),
415 OPT_STRING(0, "match", &pattern, N_("pattern"),
416 N_("only consider tags matching <pattern>")),
417 OPT_BOOL(0, "always", &always,
418 N_("show abbreviated commit object as fallback")),
419 {OPTION_STRING, 0, "dirty", &dirty, N_("mark"),
420 N_("append <mark> on dirty working tree (default: \"-dirty\")"),
421 PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
422 OPT_END(),
423 };
424
425 git_config(git_default_config, NULL);
426 argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
427 if (abbrev < 0)
428 abbrev = DEFAULT_ABBREV;
429
430 if (max_candidates < 0)
431 max_candidates = 0;
432 else if (max_candidates > MAX_TAGS)
433 max_candidates = MAX_TAGS;
434
435 save_commit_buffer = 0;
436
437 if (longformat && abbrev == 0)
438 die(_("--long is incompatible with --abbrev=0"));
439
440 if (contains) {
441 struct argv_array args;
442
443 argv_array_init(&args);
444 argv_array_pushl(&args, "name-rev",
445 "--peel-tag", "--name-only", "--no-undefined",
446 NULL);
447 if (always)
448 argv_array_push(&args, "--always");
449 if (!all) {
450 argv_array_push(&args, "--tags");
451 if (pattern)
452 argv_array_pushf(&args, "--refs=refs/tags/%s", pattern);
453 }
454 if (argc)
455 argv_array_pushv(&args, argv);
456 else
457 argv_array_push(&args, "HEAD");
458 return cmd_name_rev(args.argc, args.argv, prefix);
459 }
460
461 hashmap_init(&names, (hashmap_cmp_fn) commit_name_cmp, 0);
462 for_each_rawref(get_name, NULL);
463 if (!names.size && !always)
464 die(_("No names found, cannot describe anything."));
465
466 if (argc == 0) {
467 if (dirty) {
468 static struct lock_file index_lock;
469 int fd;
470
471 read_cache_preload(NULL);
472 refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
473 NULL, NULL, NULL);
474 fd = hold_locked_index(&index_lock, 0);
475 if (0 <= fd)
476 update_index_if_able(&the_index, &index_lock);
477
478 if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
479 diff_index_args, prefix))
480 dirty = NULL;
481 }
482 describe("HEAD", 1);
483 } else if (dirty) {
484 die(_("--dirty is incompatible with commit-ishes"));
485 } else {
486 while (argc-- > 0)
487 describe(*argv++, argc == 0);
488 }
489 return 0;
490 }