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 struct commit_name *find_commit_name(const unsigned char *peeled)
  60 {
  61         return hashmap_get_from_hash(&names, sha1hash(peeled), peeled);
  62 }
  63
  64 static int replace_name(struct commit_name *e,
  65                                int prio,
  66                                const unsigned char *sha1,
  67                                struct tag **tag)
  68 {
  69         if (!e || e->prio < prio)
  70                 return 1;
  71
  72         if (e->prio == 2 && prio == 2) {
  73                 /* Multiple annotated tags point to the same commit.
  74                  * Select one to keep based upon their tagger date.
  75                  */
  76                 struct tag *t;
  77
  78                 if (!e->tag) {
  79                         t = lookup_tag(e->sha1);
  80                         if (!t || parse_tag(t))
  81                                 return 1;
  82                         e->tag = t;
  83                 }
  84
  85                 t = lookup_tag(sha1);
  86                 if (!t || parse_tag(t))
  87                         return 0;
  88                 *tag = t;
  89
  90                 if (e->tag->date < t->date)
  91                         return 1;
  92         }
  93
  94         return 0;
  95 }
  96
  97 static void add_to_known_names(const char *path,
  98                                const unsigned char *peeled,
  99                                int prio,
 100                                const unsigned char *sha1)
 101 {
 102         struct commit_name *e = find_commit_name(peeled);
 103         struct tag *tag = NULL;
 104         if (replace_name(e, prio, sha1, &tag)) {
 105                 if (!e) {
 106                         e = xmalloc(sizeof(struct commit_name));
 107                         hashcpy(e->peeled, peeled);
 108                         hashmap_entry_init(e, sha1hash(peeled));
 109                         hashmap_add(&names, e);
 110                         e->path = NULL;
 111                 }
 112                 e->tag = tag;
 113                 e->prio = prio;
 114                 e->name_checked = 0;
 115                 hashcpy(e->sha1, sha1);
 116                 free(e->path);
 117                 e->path = xstrdup(path);
 118         }
 119 }
 120
 121 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 122 {
 123         int is_tag = starts_with(path, "refs/tags/");
 124         unsigned char peeled[20];
 125         int is_annotated, prio;
 126
 127         /* Reject anything outside refs/tags/ unless --all */
 128         if (!all && !is_tag)
 129                 return 0;
 130
 131         /* Accept only tags that match the pattern, if given */
 132         if (pattern && (!is_tag || wildmatch(pattern, path + 10, 0, NULL)))
 133                 return 0;
 134
 135         /* Is it annotated? */
 136         if (!peel_ref(path, peeled)) {
 137                 is_annotated = !!hashcmp(sha1, peeled);
 138         } else {
 139                 hashcpy(peeled, sha1);
 140                 is_annotated = 0;
 141         }
 142
 143         /*
 144          * By default, we only use annotated tags, but with --tags
 145          * we fall back to lightweight ones (even without --tags,
 146          * we still remember lightweight ones, only to give hints
 147          * in an error message).  --all allows any refs to be used.
 148          */
 149         if (is_annotated)
 150                 prio = 2;
 151         else if (is_tag)
 152                 prio = 1;
 153         else
 154                 prio = 0;
 155
 156         add_to_known_names(all ? path + 5 : path + 10, peeled, prio, sha1);
 157         return 0;
 158 }
 159
 160 struct possible_tag {
 161         struct commit_name *name;
 162         int depth;
 163         int found_order;
 164         unsigned flag_within;
 165 };
 166
 167 static int compare_pt(const void *a_, const void *b_)
 168 {
 169         struct possible_tag *a = (struct possible_tag *)a_;
 170         struct possible_tag *b = (struct possible_tag *)b_;
 171         if (a->depth != b->depth)
 172                 return a->depth - b->depth;
 173         if (a->found_order != b->found_order)
 174                 return a->found_order - b->found_order;
 175         return 0;
 176 }
 177
 178 static unsigned long finish_depth_computation(
 179         struct commit_list **list,
 180         struct possible_tag *best)
 181 {
 182         unsigned long seen_commits = 0;
 183         while (*list) {
 184                 struct commit *c = pop_commit(list);
 185                 struct commit_list *parents = c->parents;
 186                 seen_commits++;
 187                 if (c->object.flags & best->flag_within) {
 188                         struct commit_list *a = *list;
 189                         while (a) {
 190                                 struct commit *i = a->item;
 191                                 if (!(i->object.flags & best->flag_within))
 192                                         break;
 193                                 a = a->next;
 194                         }
 195                         if (!a)
 196                                 break;
 197                 } else
 198                         best->depth++;
 199                 while (parents) {
 200                         struct commit *p = parents->item;
 201                         parse_commit(p);
 202                         if (!(p->object.flags & SEEN))
 203                                 commit_list_insert_by_date(p, list);
 204                         p->object.flags |= c->object.flags;
 205                         parents = parents->next;
 206                 }
 207         }
 208         return seen_commits;
 209 }
 210
 211 static void display_name(struct commit_name *n)
 212 {
 213         if (n->prio == 2 && !n->tag) {
 214                 n->tag = lookup_tag(n->sha1);
 215                 if (!n->tag || parse_tag(n->tag))
 216                         die(_("annotated tag %s not available"), n->path);
 217         }
 218         if (n->tag && !n->name_checked) {
 219                 if (!n->tag->tag)
 220                         die(_("annotated tag %s has no embedded name"), n->path);
 221                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 222                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 223                 n->name_checked = 1;
 224         }
 225
 226         if (n->tag)
 227                 printf("%s", n->tag->tag);
 228         else
 229                 printf("%s", n->path);
 230 }
 231
 232 static void show_suffix(int depth, const unsigned char *sha1)
 233 {
 234         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 235 }
 236
 237 static void describe(const char *arg, int last_one)
 238 {
 239         unsigned char sha1[20];
 240         struct commit *cmit, *gave_up_on = NULL;
 241         struct commit_list *list;
 242         struct commit_name *n;
 243         struct possible_tag all_matches[MAX_TAGS];
 244         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 245         unsigned long seen_commits = 0;
 246         unsigned int unannotated_cnt = 0;
 247
 248         if (get_sha1(arg, sha1))
 249                 die(_("Not a valid object name %s"), arg);
 250         cmit = lookup_commit_reference(sha1);
 251         if (!cmit)
 252                 die(_("%s is not a valid '%s' object"), arg, commit_type);
 253
 254         n = find_commit_name(cmit->object.sha1);
 255         if (n && (tags || all || n->prio == 2)) {
 256                 /*
 257                  * Exact match to an existing ref.
 258                  */
 259                 display_name(n);
 260                 if (longformat)
 261                         show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 262                 if (dirty)
 263                         printf("%s", dirty);
 264                 printf("\n");
 265                 return;
 266         }
 267
 268         if (!max_candidates)
 269                 die(_("no tag exactly matches '%s'"), sha1_to_hex(cmit->object.sha1));
 270         if (debug)
 271                 fprintf(stderr, _("searching to describe %s\n"), arg);
 272
 273         if (!have_util) {
 274                 struct hashmap_iter iter;
 275                 struct commit *c;
 276                 struct commit_name *n = hashmap_iter_first(&names, &iter);
 277                 for (; n; n = hashmap_iter_next(&iter)) {
 278                         c = lookup_commit_reference_gently(n->peeled, 1);
 279                         if (c)
 280                                 c->util = n;
 281                 }
 282                 have_util = 1;
 283         }
 284
 285         list = NULL;
 286         cmit->object.flags = SEEN;
 287         commit_list_insert(cmit, &list);
 288         while (list) {
 289                 struct commit *c = pop_commit(&list);
 290                 struct commit_list *parents = c->parents;
 291                 seen_commits++;
 292                 n = c->util;
 293                 if (n) {
 294                         if (!tags && !all && n->prio < 2) {
 295                                 unannotated_cnt++;
 296                         } else if (match_cnt < max_candidates) {
 297                                 struct possible_tag *t = &all_matches[match_cnt++];
 298                                 t->name = n;
 299                                 t->depth = seen_commits - 1;
 300                                 t->flag_within = 1u << match_cnt;
 301                                 t->found_order = match_cnt;
 302                                 c->object.flags |= t->flag_within;
 303                                 if (n->prio == 2)
 304                                         annotated_cnt++;
 305                         }
 306                         else {
 307                                 gave_up_on = c;
 308                                 break;
 309                         }
 310                 }
 311                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 312                         struct possible_tag *t = &all_matches[cur_match];
 313                         if (!(c->object.flags & t->flag_within))
 314                                 t->depth++;
 315                 }
 316                 if (annotated_cnt && !list) {
 317                         if (debug)
 318                                 fprintf(stderr, _("finished search at %s\n"),
 319                                         sha1_to_hex(c->object.sha1));
 320                         break;
 321                 }
 322                 while (parents) {
 323                         struct commit *p = parents->item;
 324                         parse_commit(p);
 325                         if (!(p->object.flags & SEEN))
 326                                 commit_list_insert_by_date(p, &list);
 327                         p->object.flags |= c->object.flags;
 328                         parents = parents->next;
 329
 330                         if (first_parent)
 331                                 break;
 332                 }
 333         }
 334
 335         if (!match_cnt) {
 336                 const unsigned char *sha1 = cmit->object.sha1;
 337                 if (always) {
 338                         printf("%s", find_unique_abbrev(sha1, abbrev));
 339                         if (dirty)
 340                                 printf("%s", dirty);
 341                         printf("\n");
 342                         return;
 343                 }
 344                 if (unannotated_cnt)
 345                         die(_("No annotated tags can describe '%s'.\n"
 346                             "However, there were unannotated tags: try --tags."),
 347                             sha1_to_hex(sha1));
 348                 else
 349                         die(_("No tags can describe '%s'.\n"
 350                             "Try --always, or create some tags."),
 351                             sha1_to_hex(sha1));
 352         }
 353
 354         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 355
 356         if (gave_up_on) {
 357                 commit_list_insert_by_date(gave_up_on, &list);
 358                 seen_commits--;
 359         }
 360         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 361         free_commit_list(list);
 362
 363         if (debug) {
 364                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 365                         struct possible_tag *t = &all_matches[cur_match];
 366                         fprintf(stderr, " %-11s %8d %s\n",
 367                                 prio_names[t->name->prio],
 368                                 t->depth, t->name->path);
 369                 }
 370                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 371                 if (gave_up_on) {
 372                         fprintf(stderr,
 373                                 _("more than %i tags found; listed %i most recent\n"
 374                                 "gave up search at %s\n"),
 375                                 max_candidates, max_candidates,
 376                                 sha1_to_hex(gave_up_on->object.sha1));
 377                 }
 378         }
 379
 380         display_name(all_matches[0].name);
 381         if (abbrev)
 382                 show_suffix(all_matches[0].depth, cmit->object.sha1);
 383         if (dirty)
 384                 printf("%s", dirty);
 385         printf("\n");
 386
 387         if (!last_one)
 388                 clear_commit_marks(cmit, -1);
 389 }
 390
 391 int cmd_describe(int argc, const char **argv, const char *prefix)
 392 {
 393         int contains = 0;
 394         struct option options[] = {
 395                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 396                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
 397                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
 398                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
 399                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
 400                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
 401                 OPT__ABBREV(&abbrev),
 402                 OPT_SET_INT(0, "exact-match", &max_candidates,
 403                             N_("only output exact matches"), 0),
 404                 OPT_INTEGER(0, "candidates", &max_candidates,
 405                             N_("consider <n> most recent tags (default: 10)")),
 406                 OPT_STRING(0, "match",       &pattern, N_("pattern"),
 407                            N_("only consider tags matching <pattern>")),
 408                 OPT_BOOL(0, "always",        &always,
 409                         N_("show abbreviated commit object as fallback")),
 410                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 411                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 412                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 413                 OPT_END(),
 414         };
 415
 416         git_config(git_default_config, NULL);
 417         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 418         if (abbrev < 0)
 419                 abbrev = DEFAULT_ABBREV;
 420
 421         if (max_candidates < 0)
 422                 max_candidates = 0;
 423         else if (max_candidates > MAX_TAGS)
 424                 max_candidates = MAX_TAGS;
 425
 426         save_commit_buffer = 0;
 427
 428         if (longformat && abbrev == 0)
 429                 die(_("--long is incompatible with --abbrev=0"));
 430
 431         if (contains) {
 432                 struct argv_array args;
 433
 434                 argv_array_init(&args);
 435                 argv_array_pushl(&args, "name-rev",
 436                                  "--peel-tag", "--name-only", "--no-undefined",
 437                                  NULL);
 438                 if (always)
 439                         argv_array_push(&args, "--always");
 440                 if (!all) {
 441                         argv_array_push(&args, "--tags");
 442                         if (pattern)
 443                                 argv_array_pushf(&args, "--refs=refs/tags/%s", pattern);
 444                 }
 445                 while (*argv) {
 446                         argv_array_push(&args, *argv);
 447                         argv++;
 448                 }
 449                 return cmd_name_rev(args.argc, args.argv, prefix);
 450         }
 451
 452         hashmap_init(&names, (hashmap_cmp_fn) commit_name_cmp, 0);
 453         for_each_rawref(get_name, NULL);
 454         if (!names.size && !always)
 455                 die(_("No names found, cannot describe anything."));
 456
 457         if (argc == 0) {
 458                 if (dirty) {
 459                         static struct lock_file index_lock;
 460                         int fd;
 461
 462                         read_cache_preload(NULL);
 463                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 464                                       NULL, NULL, NULL);
 465                         fd = hold_locked_index(&index_lock, 0);
 466                         if (0 <= fd)
 467                                 update_index_if_able(&the_index, &index_lock);
 468
 469                         if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
 470                                             diff_index_args, prefix))
 471                                 dirty = NULL;
 472                 }
 473                 describe("HEAD", 1);
 474         } else if (dirty) {
 475                 die(_("--dirty is incompatible with commit-ishes"));
 476         } else {
 477                 while (argc-- > 0)
 478                         describe(*argv++, argc == 0);
 479         }
 480         return 0;
 481 }