Merge branch 'kh/tutorial-grammofix' into maint
[git] / builtin / describe.c
1 #include "cache.h"
2 #include "lockfile.h"
3 #include "commit.h"
4 #include "tag.h"
5 #include "refs.h"
6 #include "builtin.h"
7 #include "exec_cmd.h"
8 #include "parse-options.h"
9 #include "diff.h"
10 #include "hashmap.h"
11 #include "argv-array.h"
12
13 #define SEEN            (1u << 0)
14 #define MAX_TAGS        (FLAG_BITS - 1)
15
16 static const char * const describe_usage[] = {
17         N_("git describe [<options>] [<commit-ish>...]"),
18         N_("git describe [<options>] --dirty"),
19         NULL
20 };
21
22 static int debug;       /* Display lots of verbose info */
23 static int all; /* Any valid ref can be used */
24 static int tags;        /* Allow lightweight tags */
25 static int longformat;
26 static int first_parent;
27 static int abbrev = -1; /* unspecified */
28 static int max_candidates = 10;
29 static struct hashmap names;
30 static int have_util;
31 static const char *pattern;
32 static int always;
33 static const char *dirty;
34
35 /* diff-index command arguments to check if working tree is dirty. */
36 static const char *diff_index_args[] = {
37         "diff-index", "--quiet", "HEAD", "--", NULL
38 };
39
40 struct commit_name {
41         struct hashmap_entry entry;
42         unsigned char peeled[20];
43         struct tag *tag;
44         unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
45         unsigned name_checked:1;
46         unsigned char sha1[20];
47         char *path;
48 };
49
50 static const char *prio_names[] = {
51         "head", "lightweight", "annotated",
52 };
53
54 static int commit_name_cmp(const struct commit_name *cn1,
55                 const struct commit_name *cn2, const void *peeled)
56 {
57         return hashcmp(cn1->peeled, peeled ? peeled : cn2->peeled);
58 }
59
60 static inline struct commit_name *find_commit_name(const unsigned char *peeled)
61 {
62         return hashmap_get_from_hash(&names, sha1hash(peeled), peeled);
63 }
64
65 static int replace_name(struct commit_name *e,
66                                int prio,
67                                const unsigned char *sha1,
68                                struct tag **tag)
69 {
70         if (!e || e->prio < prio)
71                 return 1;
72
73         if (e->prio == 2 && prio == 2) {
74                 /* Multiple annotated tags point to the same commit.
75                  * Select one to keep based upon their tagger date.
76                  */
77                 struct tag *t;
78
79                 if (!e->tag) {
80                         t = lookup_tag(e->sha1);
81                         if (!t || parse_tag(t))
82                                 return 1;
83                         e->tag = t;
84                 }
85
86                 t = lookup_tag(sha1);
87                 if (!t || parse_tag(t))
88                         return 0;
89                 *tag = t;
90
91                 if (e->tag->date < t->date)
92                         return 1;
93         }
94
95         return 0;
96 }
97
98 static void add_to_known_names(const char *path,
99                                const unsigned char *peeled,
100                                int prio,
101                                const unsigned char *sha1)
102 {
103         struct commit_name *e = find_commit_name(peeled);
104         struct tag *tag = NULL;
105         if (replace_name(e, prio, sha1, &tag)) {
106                 if (!e) {
107                         e = xmalloc(sizeof(struct commit_name));
108                         hashcpy(e->peeled, peeled);
109                         hashmap_entry_init(e, sha1hash(peeled));
110                         hashmap_add(&names, e);
111                         e->path = NULL;
112                 }
113                 e->tag = tag;
114                 e->prio = prio;
115                 e->name_checked = 0;
116                 hashcpy(e->sha1, sha1);
117                 free(e->path);
118                 e->path = xstrdup(path);
119         }
120 }
121
122 static int get_name(const char *path, const struct object_id *oid, int flag, void *cb_data)
123 {
124         int is_tag = starts_with(path, "refs/tags/");
125         struct object_id peeled;
126         int is_annotated, prio;
127
128         /* Reject anything outside refs/tags/ unless --all */
129         if (!all && !is_tag)
130                 return 0;
131
132         /* Accept only tags that match the pattern, if given */
133         if (pattern && (!is_tag || wildmatch(pattern, path + 10, 0, NULL)))
134                 return 0;
135
136         /* Is it annotated? */
137         if (!peel_ref(path, peeled.hash)) {
138                 is_annotated = !!oidcmp(oid, &peeled);
139         } else {
140                 oidcpy(&peeled, oid);
141                 is_annotated = 0;
142         }
143
144         /*
145          * By default, we only use annotated tags, but with --tags
146          * we fall back to lightweight ones (even without --tags,
147          * we still remember lightweight ones, only to give hints
148          * in an error message).  --all allows any refs to be used.
149          */
150         if (is_annotated)
151                 prio = 2;
152         else if (is_tag)
153                 prio = 1;
154         else
155                 prio = 0;
156
157         add_to_known_names(all ? path + 5 : path + 10, peeled.hash, prio, oid->hash);
158         return 0;
159 }
160
161 struct possible_tag {
162         struct commit_name *name;
163         int depth;
164         int found_order;
165         unsigned flag_within;
166 };
167
168 static int compare_pt(const void *a_, const void *b_)
169 {
170         struct possible_tag *a = (struct possible_tag *)a_;
171         struct possible_tag *b = (struct possible_tag *)b_;
172         if (a->depth != b->depth)
173                 return a->depth - b->depth;
174         if (a->found_order != b->found_order)
175                 return a->found_order - b->found_order;
176         return 0;
177 }
178
179 static unsigned long finish_depth_computation(
180         struct commit_list **list,
181         struct possible_tag *best)
182 {
183         unsigned long seen_commits = 0;
184         while (*list) {
185                 struct commit *c = pop_commit(list);
186                 struct commit_list *parents = c->parents;
187                 seen_commits++;
188                 if (c->object.flags & best->flag_within) {
189                         struct commit_list *a = *list;
190                         while (a) {
191                                 struct commit *i = a->item;
192                                 if (!(i->object.flags & best->flag_within))
193                                         break;
194                                 a = a->next;
195                         }
196                         if (!a)
197                                 break;
198                 } else
199                         best->depth++;
200                 while (parents) {
201                         struct commit *p = parents->item;
202                         parse_commit(p);
203                         if (!(p->object.flags & SEEN))
204                                 commit_list_insert_by_date(p, list);
205                         p->object.flags |= c->object.flags;
206                         parents = parents->next;
207                 }
208         }
209         return seen_commits;
210 }
211
212 static void display_name(struct commit_name *n)
213 {
214         if (n->prio == 2 && !n->tag) {
215                 n->tag = lookup_tag(n->sha1);
216                 if (!n->tag || parse_tag(n->tag))
217                         die(_("annotated tag %s not available"), n->path);
218         }
219         if (n->tag && !n->name_checked) {
220                 if (!n->tag->tag)
221                         die(_("annotated tag %s has no embedded name"), n->path);
222                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
223                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
224                 n->name_checked = 1;
225         }
226
227         if (n->tag)
228                 printf("%s", n->tag->tag);
229         else
230                 printf("%s", n->path);
231 }
232
233 static void show_suffix(int depth, const unsigned char *sha1)
234 {
235         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
236 }
237
238 static void describe(const char *arg, int last_one)
239 {
240         unsigned char sha1[20];
241         struct commit *cmit, *gave_up_on = NULL;
242         struct commit_list *list;
243         struct commit_name *n;
244         struct possible_tag all_matches[MAX_TAGS];
245         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
246         unsigned long seen_commits = 0;
247         unsigned int unannotated_cnt = 0;
248
249         if (get_sha1(arg, sha1))
250                 die(_("Not a valid object name %s"), arg);
251         cmit = lookup_commit_reference(sha1);
252         if (!cmit)
253                 die(_("%s is not a valid '%s' object"), arg, commit_type);
254
255         n = find_commit_name(cmit->object.oid.hash);
256         if (n && (tags || all || n->prio == 2)) {
257                 /*
258                  * Exact match to an existing ref.
259                  */
260                 display_name(n);
261                 if (longformat)
262                         show_suffix(0, n->tag ? n->tag->tagged->oid.hash : sha1);
263                 if (dirty)
264                         printf("%s", dirty);
265                 printf("\n");
266                 return;
267         }
268
269         if (!max_candidates)
270                 die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));
271         if (debug)
272                 fprintf(stderr, _("searching to describe %s\n"), arg);
273
274         if (!have_util) {
275                 struct hashmap_iter iter;
276                 struct commit *c;
277                 struct commit_name *n = hashmap_iter_first(&names, &iter);
278                 for (; n; n = hashmap_iter_next(&iter)) {
279                         c = lookup_commit_reference_gently(n->peeled, 1);
280                         if (c)
281                                 c->util = n;
282                 }
283                 have_util = 1;
284         }
285
286         list = NULL;
287         cmit->object.flags = SEEN;
288         commit_list_insert(cmit, &list);
289         while (list) {
290                 struct commit *c = pop_commit(&list);
291                 struct commit_list *parents = c->parents;
292                 seen_commits++;
293                 n = c->util;
294                 if (n) {
295                         if (!tags && !all && n->prio < 2) {
296                                 unannotated_cnt++;
297                         } else if (match_cnt < max_candidates) {
298                                 struct possible_tag *t = &all_matches[match_cnt++];
299                                 t->name = n;
300                                 t->depth = seen_commits - 1;
301                                 t->flag_within = 1u << match_cnt;
302                                 t->found_order = match_cnt;
303                                 c->object.flags |= t->flag_within;
304                                 if (n->prio == 2)
305                                         annotated_cnt++;
306                         }
307                         else {
308                                 gave_up_on = c;
309                                 break;
310                         }
311                 }
312                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
313                         struct possible_tag *t = &all_matches[cur_match];
314                         if (!(c->object.flags & t->flag_within))
315                                 t->depth++;
316                 }
317                 if (annotated_cnt && !list) {
318                         if (debug)
319                                 fprintf(stderr, _("finished search at %s\n"),
320                                         oid_to_hex(&c->object.oid));
321                         break;
322                 }
323                 while (parents) {
324                         struct commit *p = parents->item;
325                         parse_commit(p);
326                         if (!(p->object.flags & SEEN))
327                                 commit_list_insert_by_date(p, &list);
328                         p->object.flags |= c->object.flags;
329                         parents = parents->next;
330
331                         if (first_parent)
332                                 break;
333                 }
334         }
335
336         if (!match_cnt) {
337                 struct object_id *oid = &cmit->object.oid;
338                 if (always) {
339                         printf("%s", find_unique_abbrev(oid->hash, abbrev));
340                         if (dirty)
341                                 printf("%s", dirty);
342                         printf("\n");
343                         return;
344                 }
345                 if (unannotated_cnt)
346                         die(_("No annotated tags can describe '%s'.\n"
347                             "However, there were unannotated tags: try --tags."),
348                             oid_to_hex(oid));
349                 else
350                         die(_("No tags can describe '%s'.\n"
351                             "Try --always, or create some tags."),
352                             oid_to_hex(oid));
353         }
354
355         QSORT(all_matches, match_cnt, compare_pt);
356
357         if (gave_up_on) {
358                 commit_list_insert_by_date(gave_up_on, &list);
359                 seen_commits--;
360         }
361         seen_commits += finish_depth_computation(&list, &all_matches[0]);
362         free_commit_list(list);
363
364         if (debug) {
365                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
366                         struct possible_tag *t = &all_matches[cur_match];
367                         fprintf(stderr, " %-11s %8d %s\n",
368                                 prio_names[t->name->prio],
369                                 t->depth, t->name->path);
370                 }
371                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
372                 if (gave_up_on) {
373                         fprintf(stderr,
374                                 _("more than %i tags found; listed %i most recent\n"
375                                 "gave up search at %s\n"),
376                                 max_candidates, max_candidates,
377                                 oid_to_hex(&gave_up_on->object.oid));
378                 }
379         }
380
381         display_name(all_matches[0].name);
382         if (abbrev)
383                 show_suffix(all_matches[0].depth, cmit->object.oid.hash);
384         if (dirty)
385                 printf("%s", dirty);
386         printf("\n");
387
388         if (!last_one)
389                 clear_commit_marks(cmit, -1);
390 }
391
392 int cmd_describe(int argc, const char **argv, const char *prefix)
393 {
394         int contains = 0;
395         struct option options[] = {
396                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
397                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
398                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
399                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
400                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
401                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
402                 OPT__ABBREV(&abbrev),
403                 OPT_SET_INT(0, "exact-match", &max_candidates,
404                             N_("only output exact matches"), 0),
405                 OPT_INTEGER(0, "candidates", &max_candidates,
406                             N_("consider <n> most recent tags (default: 10)")),
407                 OPT_STRING(0, "match",       &pattern, N_("pattern"),
408                            N_("only consider tags matching <pattern>")),
409                 OPT_BOOL(0, "always",        &always,
410                         N_("show abbreviated commit object as fallback")),
411                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
412                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
413                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
414                 OPT_END(),
415         };
416
417         git_config(git_default_config, NULL);
418         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
419         if (abbrev < 0)
420                 abbrev = DEFAULT_ABBREV;
421
422         if (max_candidates < 0)
423                 max_candidates = 0;
424         else if (max_candidates > MAX_TAGS)
425                 max_candidates = MAX_TAGS;
426
427         save_commit_buffer = 0;
428
429         if (longformat && abbrev == 0)
430                 die(_("--long is incompatible with --abbrev=0"));
431
432         if (contains) {
433                 struct argv_array args;
434
435                 argv_array_init(&args);
436                 argv_array_pushl(&args, "name-rev",
437                                  "--peel-tag", "--name-only", "--no-undefined",
438                                  NULL);
439                 if (always)
440                         argv_array_push(&args, "--always");
441                 if (!all) {
442                         argv_array_push(&args, "--tags");
443                         if (pattern)
444                                 argv_array_pushf(&args, "--refs=refs/tags/%s", pattern);
445                 }
446                 if (argc)
447                         argv_array_pushv(&args, argv);
448                 else
449                         argv_array_push(&args, "HEAD");
450                 return cmd_name_rev(args.argc, args.argv, prefix);
451         }
452
453         hashmap_init(&names, (hashmap_cmp_fn) commit_name_cmp, 0);
454         for_each_rawref(get_name, NULL);
455         if (!names.size && !always)
456                 die(_("No names found, cannot describe anything."));
457
458         if (argc == 0) {
459                 if (dirty) {
460                         static struct lock_file index_lock;
461                         int fd;
462
463                         read_cache_preload(NULL);
464                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
465                                       NULL, NULL, NULL);
466                         fd = hold_locked_index(&index_lock, 0);
467                         if (0 <= fd)
468                                 update_index_if_able(&the_index, &index_lock);
469
470                         if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
471                                             diff_index_args, prefix))
472                                 dirty = NULL;
473                 }
474                 describe("HEAD", 1);
475         } else if (dirty) {
476                 die(_("--dirty is incompatible with commit-ishes"));
477         } else {
478                 while (argc-- > 0)
479                         describe(*argv++, argc == 0);
480         }
481         return 0;
482 }