Merge branch 'ap/merge-stop-at-prepare-commit-msg-failure'
[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 "hash.h"
10
11 #define SEEN            (1u<<0)
12 #define MAX_TAGS        (FLAG_BITS - 1)
13
14 static const char * const describe_usage[] = {
15         N_("git describe [options] <committish>*"),
16         N_("git describe [options] --dirty"),
17         NULL
18 };
19
20 static int debug;       /* Display lots of verbose info */
21 static int all; /* Any valid ref can be used */
22 static int tags;        /* Allow lightweight tags */
23 static int longformat;
24 static int abbrev = -1; /* unspecified */
25 static int max_candidates = 10;
26 static struct hash_table names;
27 static int have_util;
28 static const char *pattern;
29 static int always;
30 static const char *dirty;
31
32 /* diff-index command arguments to check if working tree is dirty. */
33 static const char *diff_index_args[] = {
34         "diff-index", "--quiet", "HEAD", "--", NULL
35 };
36
37
38 struct commit_name {
39         struct commit_name *next;
40         unsigned char peeled[20];
41         struct tag *tag;
42         unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
43         unsigned name_checked:1;
44         unsigned char sha1[20];
45         const char *path;
46 };
47 static const char *prio_names[] = {
48         "head", "lightweight", "annotated",
49 };
50
51 static inline unsigned int hash_sha1(const unsigned char *sha1)
52 {
53         unsigned int hash;
54         memcpy(&hash, sha1, sizeof(hash));
55         return hash;
56 }
57
58 static inline struct commit_name *find_commit_name(const unsigned char *peeled)
59 {
60         struct commit_name *n = lookup_hash(hash_sha1(peeled), &names);
61         while (n && !!hashcmp(peeled, n->peeled))
62                 n = n->next;
63         return n;
64 }
65
66 static int set_util(void *chain, void *data)
67 {
68         struct commit_name *n;
69         for (n = chain; n; n = n->next) {
70                 struct commit *c = lookup_commit_reference_gently(n->peeled, 1);
71                 if (c)
72                         c->util = n;
73         }
74         return 0;
75 }
76
77 static int replace_name(struct commit_name *e,
78                                int prio,
79                                const unsigned char *sha1,
80                                struct tag **tag)
81 {
82         if (!e || e->prio < prio)
83                 return 1;
84
85         if (e->prio == 2 && prio == 2) {
86                 /* Multiple annotated tags point to the same commit.
87                  * Select one to keep based upon their tagger date.
88                  */
89                 struct tag *t;
90
91                 if (!e->tag) {
92                         t = lookup_tag(e->sha1);
93                         if (!t || parse_tag(t))
94                                 return 1;
95                         e->tag = t;
96                 }
97
98                 t = lookup_tag(sha1);
99                 if (!t || parse_tag(t))
100                         return 0;
101                 *tag = t;
102
103                 if (e->tag->date < t->date)
104                         return 1;
105         }
106
107         return 0;
108 }
109
110 static void add_to_known_names(const char *path,
111                                const unsigned char *peeled,
112                                int prio,
113                                const unsigned char *sha1)
114 {
115         struct commit_name *e = find_commit_name(peeled);
116         struct tag *tag = NULL;
117         if (replace_name(e, prio, sha1, &tag)) {
118                 if (!e) {
119                         void **pos;
120                         e = xmalloc(sizeof(struct commit_name));
121                         hashcpy(e->peeled, peeled);
122                         pos = insert_hash(hash_sha1(peeled), e, &names);
123                         if (pos) {
124                                 e->next = *pos;
125                                 *pos = e;
126                         } else {
127                                 e->next = NULL;
128                         }
129                 }
130                 e->tag = tag;
131                 e->prio = prio;
132                 e->name_checked = 0;
133                 hashcpy(e->sha1, sha1);
134                 e->path = path;
135         }
136 }
137
138 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
139 {
140         int might_be_tag = !prefixcmp(path, "refs/tags/");
141         unsigned char peeled[20];
142         int is_tag, prio;
143
144         if (!all && !might_be_tag)
145                 return 0;
146
147         if (!peel_ref(path, peeled)) {
148                 is_tag = !!hashcmp(sha1, peeled);
149         } else {
150                 hashcpy(peeled, sha1);
151                 is_tag = 0;
152         }
153
154         /* If --all, then any refs are used.
155          * If --tags, then any tags are used.
156          * Otherwise only annotated tags are used.
157          */
158         if (might_be_tag) {
159                 if (is_tag)
160                         prio = 2;
161                 else
162                         prio = 1;
163
164                 if (pattern && fnmatch(pattern, path + 10, 0))
165                         prio = 0;
166         }
167         else
168                 prio = 0;
169
170         if (!all) {
171                 if (!prio)
172                         return 0;
173         }
174         add_to_known_names(all ? path + 5 : path + 10, peeled, prio, sha1);
175         return 0;
176 }
177
178 struct possible_tag {
179         struct commit_name *name;
180         int depth;
181         int found_order;
182         unsigned flag_within;
183 };
184
185 static int compare_pt(const void *a_, const void *b_)
186 {
187         struct possible_tag *a = (struct possible_tag *)a_;
188         struct possible_tag *b = (struct possible_tag *)b_;
189         if (a->depth != b->depth)
190                 return a->depth - b->depth;
191         if (a->found_order != b->found_order)
192                 return a->found_order - b->found_order;
193         return 0;
194 }
195
196 static unsigned long finish_depth_computation(
197         struct commit_list **list,
198         struct possible_tag *best)
199 {
200         unsigned long seen_commits = 0;
201         while (*list) {
202                 struct commit *c = pop_commit(list);
203                 struct commit_list *parents = c->parents;
204                 seen_commits++;
205                 if (c->object.flags & best->flag_within) {
206                         struct commit_list *a = *list;
207                         while (a) {
208                                 struct commit *i = a->item;
209                                 if (!(i->object.flags & best->flag_within))
210                                         break;
211                                 a = a->next;
212                         }
213                         if (!a)
214                                 break;
215                 } else
216                         best->depth++;
217                 while (parents) {
218                         struct commit *p = parents->item;
219                         parse_commit(p);
220                         if (!(p->object.flags & SEEN))
221                                 commit_list_insert_by_date(p, list);
222                         p->object.flags |= c->object.flags;
223                         parents = parents->next;
224                 }
225         }
226         return seen_commits;
227 }
228
229 static void display_name(struct commit_name *n)
230 {
231         if (n->prio == 2 && !n->tag) {
232                 n->tag = lookup_tag(n->sha1);
233                 if (!n->tag || parse_tag(n->tag))
234                         die(_("annotated tag %s not available"), n->path);
235         }
236         if (n->tag && !n->name_checked) {
237                 if (!n->tag->tag)
238                         die(_("annotated tag %s has no embedded name"), n->path);
239                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
240                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
241                 n->name_checked = 1;
242         }
243
244         if (n->tag)
245                 printf("%s", n->tag->tag);
246         else
247                 printf("%s", n->path);
248 }
249
250 static void show_suffix(int depth, const unsigned char *sha1)
251 {
252         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
253 }
254
255 static void describe(const char *arg, int last_one)
256 {
257         unsigned char sha1[20];
258         struct commit *cmit, *gave_up_on = NULL;
259         struct commit_list *list;
260         struct commit_name *n;
261         struct possible_tag all_matches[MAX_TAGS];
262         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
263         unsigned long seen_commits = 0;
264         unsigned int unannotated_cnt = 0;
265
266         if (get_sha1(arg, sha1))
267                 die(_("Not a valid object name %s"), arg);
268         cmit = lookup_commit_reference(sha1);
269         if (!cmit)
270                 die(_("%s is not a valid '%s' object"), arg, commit_type);
271
272         n = find_commit_name(cmit->object.sha1);
273         if (n && (tags || all || n->prio == 2)) {
274                 /*
275                  * Exact match to an existing ref.
276                  */
277                 display_name(n);
278                 if (longformat)
279                         show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
280                 if (dirty)
281                         printf("%s", dirty);
282                 printf("\n");
283                 return;
284         }
285
286         if (!max_candidates)
287                 die(_("no tag exactly matches '%s'"), sha1_to_hex(cmit->object.sha1));
288         if (debug)
289                 fprintf(stderr, _("searching to describe %s\n"), arg);
290
291         if (!have_util) {
292                 for_each_hash(&names, set_util, NULL);
293                 have_util = 1;
294         }
295
296         list = NULL;
297         cmit->object.flags = SEEN;
298         commit_list_insert(cmit, &list);
299         while (list) {
300                 struct commit *c = pop_commit(&list);
301                 struct commit_list *parents = c->parents;
302                 seen_commits++;
303                 n = c->util;
304                 if (n) {
305                         if (!tags && !all && n->prio < 2) {
306                                 unannotated_cnt++;
307                         } else if (match_cnt < max_candidates) {
308                                 struct possible_tag *t = &all_matches[match_cnt++];
309                                 t->name = n;
310                                 t->depth = seen_commits - 1;
311                                 t->flag_within = 1u << match_cnt;
312                                 t->found_order = match_cnt;
313                                 c->object.flags |= t->flag_within;
314                                 if (n->prio == 2)
315                                         annotated_cnt++;
316                         }
317                         else {
318                                 gave_up_on = c;
319                                 break;
320                         }
321                 }
322                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
323                         struct possible_tag *t = &all_matches[cur_match];
324                         if (!(c->object.flags & t->flag_within))
325                                 t->depth++;
326                 }
327                 if (annotated_cnt && !list) {
328                         if (debug)
329                                 fprintf(stderr, _("finished search at %s\n"),
330                                         sha1_to_hex(c->object.sha1));
331                         break;
332                 }
333                 while (parents) {
334                         struct commit *p = parents->item;
335                         parse_commit(p);
336                         if (!(p->object.flags & SEEN))
337                                 commit_list_insert_by_date(p, &list);
338                         p->object.flags |= c->object.flags;
339                         parents = parents->next;
340                 }
341         }
342
343         if (!match_cnt) {
344                 const unsigned char *sha1 = cmit->object.sha1;
345                 if (always) {
346                         printf("%s", find_unique_abbrev(sha1, abbrev));
347                         if (dirty)
348                                 printf("%s", dirty);
349                         printf("\n");
350                         return;
351                 }
352                 if (unannotated_cnt)
353                         die(_("No annotated tags can describe '%s'.\n"
354                             "However, there were unannotated tags: try --tags."),
355                             sha1_to_hex(sha1));
356                 else
357                         die(_("No tags can describe '%s'.\n"
358                             "Try --always, or create some tags."),
359                             sha1_to_hex(sha1));
360         }
361
362         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
363
364         if (gave_up_on) {
365                 commit_list_insert_by_date(gave_up_on, &list);
366                 seen_commits--;
367         }
368         seen_commits += finish_depth_computation(&list, &all_matches[0]);
369         free_commit_list(list);
370
371         if (debug) {
372                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
373                         struct possible_tag *t = &all_matches[cur_match];
374                         fprintf(stderr, " %-11s %8d %s\n",
375                                 prio_names[t->name->prio],
376                                 t->depth, t->name->path);
377                 }
378                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
379                 if (gave_up_on) {
380                         fprintf(stderr,
381                                 _("more than %i tags found; listed %i most recent\n"
382                                 "gave up search at %s\n"),
383                                 max_candidates, max_candidates,
384                                 sha1_to_hex(gave_up_on->object.sha1));
385                 }
386         }
387
388         display_name(all_matches[0].name);
389         if (abbrev)
390                 show_suffix(all_matches[0].depth, cmit->object.sha1);
391         if (dirty)
392                 printf("%s", dirty);
393         printf("\n");
394
395         if (!last_one)
396                 clear_commit_marks(cmit, -1);
397 }
398
399 int cmd_describe(int argc, const char **argv, const char *prefix)
400 {
401         int contains = 0;
402         struct option options[] = {
403                 OPT_BOOLEAN(0, "contains",   &contains, N_("find the tag that comes after the commit")),
404                 OPT_BOOLEAN(0, "debug",      &debug, N_("debug search strategy on stderr")),
405                 OPT_BOOLEAN(0, "all",        &all, N_("use any ref in .git/refs")),
406                 OPT_BOOLEAN(0, "tags",       &tags, N_("use any tag in .git/refs/tags")),
407                 OPT_BOOLEAN(0, "long",       &longformat, N_("always use long format")),
408                 OPT__ABBREV(&abbrev),
409                 OPT_SET_INT(0, "exact-match", &max_candidates,
410                             N_("only output exact matches"), 0),
411                 OPT_INTEGER(0, "candidates", &max_candidates,
412                             N_("consider <n> most recent tags (default: 10)")),
413                 OPT_STRING(0, "match",       &pattern, N_("pattern"),
414                            N_("only consider tags matching <pattern>")),
415                 OPT_BOOLEAN(0, "always",     &always,
416                            N_("show abbreviated commit object as fallback")),
417                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
418                            N_("append <mark> on dirty working tree (default: \"-dirty\")"),
419                  PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
420                 OPT_END(),
421         };
422
423         git_config(git_default_config, NULL);
424         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
425         if (abbrev < 0)
426                 abbrev = DEFAULT_ABBREV;
427
428         if (max_candidates < 0)
429                 max_candidates = 0;
430         else if (max_candidates > MAX_TAGS)
431                 max_candidates = MAX_TAGS;
432
433         save_commit_buffer = 0;
434
435         if (longformat && abbrev == 0)
436                 die(_("--long is incompatible with --abbrev=0"));
437
438         if (contains) {
439                 const char **args = xmalloc((7 + argc) * sizeof(char *));
440                 int i = 0;
441                 args[i++] = "name-rev";
442                 args[i++] = "--name-only";
443                 args[i++] = "--no-undefined";
444                 if (always)
445                         args[i++] = "--always";
446                 if (!all) {
447                         args[i++] = "--tags";
448                         if (pattern) {
449                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
450                                 sprintf(s, "--refs=refs/tags/%s", pattern);
451                                 args[i++] = s;
452                         }
453                 }
454                 memcpy(args + i, argv, argc * sizeof(char *));
455                 args[i + argc] = NULL;
456                 return cmd_name_rev(i + argc, args, prefix);
457         }
458
459         init_hash(&names);
460         for_each_rawref(get_name, NULL);
461         if (!names.nr && !always)
462                 die(_("No names found, cannot describe anything."));
463
464         if (argc == 0) {
465                 if (dirty) {
466                         static struct lock_file index_lock;
467                         int fd;
468
469                         read_cache_preload(NULL);
470                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
471                                       NULL, NULL, NULL);
472                         fd = hold_locked_index(&index_lock, 0);
473                         if (0 <= fd)
474                                 update_index_if_able(&the_index, &index_lock);
475
476                         if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
477                                             diff_index_args, prefix))
478                                 dirty = NULL;
479                 }
480                 describe("HEAD", 1);
481         } else if (dirty) {
482                 die(_("--dirty is incompatible with committishes"));
483         } else {
484                 while (argc-- > 0) {
485                         describe(*argv++, argc == 0);
486                 }
487         }
488         return 0;
489 }