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 void *entry,
  59                            const void *entry_or_key,
  60                            const void *peeled)
  61 {
  62         const struct commit_name *cn1 = entry;
  63         const struct commit_name *cn2 = entry_or_key;
  64
  65         return oidcmp(&cn1->peeled, peeled ? peeled : &cn2->peeled);
  66 }
  67
  68 static inline struct commit_name *find_commit_name(const struct object_id *peeled)
  69 {
  70         return hashmap_get_from_hash(&names, sha1hash(peeled->hash), peeled->hash);
  71 }
  72
  73 static int replace_name(struct commit_name *e,
  74                                int prio,
  75                                const struct object_id *oid,
  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->oid);
  89                         if (!t || parse_tag(t))
  90                                 return 1;
  91                         e->tag = t;
  92                 }
  93
  94                 t = lookup_tag(oid);
  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 struct object_id *peeled,
 108                                int prio,
 109                                const struct object_id *oid)
 110 {
 111         struct commit_name *e = find_commit_name(peeled);
 112         struct tag *tag = NULL;
 113         if (replace_name(e, prio, oid, &tag)) {
 114                 if (!e) {
 115                         e = xmalloc(sizeof(struct commit_name));
 116                         oidcpy(&e->peeled, peeled);
 117                         hashmap_entry_init(e, sha1hash(peeled->hash));
 118                         hashmap_add(&names, e);
 119                         e->path = NULL;
 120                 }
 121                 e->tag = tag;
 122                 e->prio = prio;
 123                 e->name_checked = 0;
 124                 oidcpy(&e->oid, oid);
 125                 free(e->path);
 126                 e->path = xstrdup(path);
 127         }
 128 }
 129
 130 static int get_name(const char *path, const struct object_id *oid, int flag, void *cb_data)
 131 {
 132         int is_tag = 0;
 133         struct object_id peeled;
 134         int is_annotated, prio;
 135         const char *path_to_match = NULL;
 136
 137         if (skip_prefix(path, "refs/tags/", &path_to_match)) {
 138                 is_tag = 1;
 139         } else if (all) {
 140                 if ((exclude_patterns.nr || patterns.nr) &&
 141                     !skip_prefix(path, "refs/heads/", &path_to_match) &&
 142                     !skip_prefix(path, "refs/remotes/", &path_to_match)) {
 143                         /* Only accept reference of known type if there are match/exclude patterns */
 144                         return 0;
 145                 }
 146         } else {
 147                 /* Reject anything outside refs/tags/ unless --all */
 148                 return 0;
 149         }
 150
 151         /*
 152          * If we're given exclude patterns, first exclude any tag which match
 153          * any of the exclude pattern.
 154          */
 155         if (exclude_patterns.nr) {
 156                 struct string_list_item *item;
 157
 158                 for_each_string_list_item(item, &exclude_patterns) {
 159                         if (!wildmatch(item->string, path_to_match, 0))
 160                                 return 0;
 161                 }
 162         }
 163
 164         /*
 165          * If we're given patterns, accept only tags which match at least one
 166          * pattern.
 167          */
 168         if (patterns.nr) {
 169                 int found = 0;
 170                 struct string_list_item *item;
 171
 172                 for_each_string_list_item(item, &patterns) {
 173                         if (!wildmatch(item->string, path_to_match, 0)) {
 174                                 found = 1;
 175                                 break;
 176                         }
 177                 }
 178
 179                 if (!found)
 180                         return 0;
 181         }
 182
 183         /* Is it annotated? */
 184         if (!peel_ref(path, peeled.hash)) {
 185                 is_annotated = !!oidcmp(oid, &peeled);
 186         } else {
 187                 oidcpy(&peeled, oid);
 188                 is_annotated = 0;
 189         }
 190
 191         /*
 192          * By default, we only use annotated tags, but with --tags
 193          * we fall back to lightweight ones (even without --tags,
 194          * we still remember lightweight ones, only to give hints
 195          * in an error message).  --all allows any refs to be used.
 196          */
 197         if (is_annotated)
 198                 prio = 2;
 199         else if (is_tag)
 200                 prio = 1;
 201         else
 202                 prio = 0;
 203
 204         add_to_known_names(all ? path + 5 : path + 10, &peeled, prio, oid);
 205         return 0;
 206 }
 207
 208 struct possible_tag {
 209         struct commit_name *name;
 210         int depth;
 211         int found_order;
 212         unsigned flag_within;
 213 };
 214
 215 static int compare_pt(const void *a_, const void *b_)
 216 {
 217         struct possible_tag *a = (struct possible_tag *)a_;
 218         struct possible_tag *b = (struct possible_tag *)b_;
 219         if (a->depth != b->depth)
 220                 return a->depth - b->depth;
 221         if (a->found_order != b->found_order)
 222                 return a->found_order - b->found_order;
 223         return 0;
 224 }
 225
 226 static unsigned long finish_depth_computation(
 227         struct commit_list **list,
 228         struct possible_tag *best)
 229 {
 230         unsigned long seen_commits = 0;
 231         while (*list) {
 232                 struct commit *c = pop_commit(list);
 233                 struct commit_list *parents = c->parents;
 234                 seen_commits++;
 235                 if (c->object.flags & best->flag_within) {
 236                         struct commit_list *a = *list;
 237                         while (a) {
 238                                 struct commit *i = a->item;
 239                                 if (!(i->object.flags & best->flag_within))
 240                                         break;
 241                                 a = a->next;
 242                         }
 243                         if (!a)
 244                                 break;
 245                 } else
 246                         best->depth++;
 247                 while (parents) {
 248                         struct commit *p = parents->item;
 249                         parse_commit(p);
 250                         if (!(p->object.flags & SEEN))
 251                                 commit_list_insert_by_date(p, list);
 252                         p->object.flags |= c->object.flags;
 253                         parents = parents->next;
 254                 }
 255         }
 256         return seen_commits;
 257 }
 258
 259 static void display_name(struct commit_name *n)
 260 {
 261         if (n->prio == 2 && !n->tag) {
 262                 n->tag = lookup_tag(&n->oid);
 263                 if (!n->tag || parse_tag(n->tag))
 264                         die(_("annotated tag %s not available"), n->path);
 265         }
 266         if (n->tag && !n->name_checked) {
 267                 if (!n->tag->tag)
 268                         die(_("annotated tag %s has no embedded name"), n->path);
 269                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 270                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 271                 n->name_checked = 1;
 272         }
 273
 274         if (n->tag)
 275                 printf("%s", n->tag->tag);
 276         else
 277                 printf("%s", n->path);
 278 }
 279
 280 static void show_suffix(int depth, const struct object_id *oid)
 281 {
 282         printf("-%d-g%s", depth, find_unique_abbrev(oid->hash, abbrev));
 283 }
 284
 285 static void describe(const char *arg, int last_one)
 286 {
 287         struct object_id oid;
 288         struct commit *cmit, *gave_up_on = NULL;
 289         struct commit_list *list;
 290         struct commit_name *n;
 291         struct possible_tag all_matches[MAX_TAGS];
 292         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 293         unsigned long seen_commits = 0;
 294         unsigned int unannotated_cnt = 0;
 295
 296         if (get_oid(arg, &oid))
 297                 die(_("Not a valid object name %s"), arg);
 298         cmit = lookup_commit_reference(&oid);
 299         if (!cmit)
 300                 die(_("%s is not a valid '%s' object"), arg, commit_type);
 301
 302         n = find_commit_name(&cmit->object.oid);
 303         if (n && (tags || all || n->prio == 2)) {
 304                 /*
 305                  * Exact match to an existing ref.
 306                  */
 307                 display_name(n);
 308                 if (longformat)
 309                         show_suffix(0, n->tag ? &n->tag->tagged->oid : &oid);
 310                 if (suffix)
 311                         printf("%s", suffix);
 312                 printf("\n");
 313                 return;
 314         }
 315
 316         if (!max_candidates)
 317                 die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));
 318         if (debug)
 319                 fprintf(stderr, _("searching to describe %s\n"), arg);
 320
 321         if (!have_util) {
 322                 struct hashmap_iter iter;
 323                 struct commit *c;
 324                 struct commit_name *n = hashmap_iter_first(&names, &iter);
 325                 for (; n; n = hashmap_iter_next(&iter)) {
 326                         c = lookup_commit_reference_gently(&n->peeled, 1);
 327                         if (c)
 328                                 c->util = n;
 329                 }
 330                 have_util = 1;
 331         }
 332
 333         list = NULL;
 334         cmit->object.flags = SEEN;
 335         commit_list_insert(cmit, &list);
 336         while (list) {
 337                 struct commit *c = pop_commit(&list);
 338                 struct commit_list *parents = c->parents;
 339                 seen_commits++;
 340                 n = c->util;
 341                 if (n) {
 342                         if (!tags && !all && n->prio < 2) {
 343                                 unannotated_cnt++;
 344                         } else if (match_cnt < max_candidates) {
 345                                 struct possible_tag *t = &all_matches[match_cnt++];
 346                                 t->name = n;
 347                                 t->depth = seen_commits - 1;
 348                                 t->flag_within = 1u << match_cnt;
 349                                 t->found_order = match_cnt;
 350                                 c->object.flags |= t->flag_within;
 351                                 if (n->prio == 2)
 352                                         annotated_cnt++;
 353                         }
 354                         else {
 355                                 gave_up_on = c;
 356                                 break;
 357                         }
 358                 }
 359                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 360                         struct possible_tag *t = &all_matches[cur_match];
 361                         if (!(c->object.flags & t->flag_within))
 362                                 t->depth++;
 363                 }
 364                 if (annotated_cnt && !list) {
 365                         if (debug)
 366                                 fprintf(stderr, _("finished search at %s\n"),
 367                                         oid_to_hex(&c->object.oid));
 368                         break;
 369                 }
 370                 while (parents) {
 371                         struct commit *p = parents->item;
 372                         parse_commit(p);
 373                         if (!(p->object.flags & SEEN))
 374                                 commit_list_insert_by_date(p, &list);
 375                         p->object.flags |= c->object.flags;
 376                         parents = parents->next;
 377
 378                         if (first_parent)
 379                                 break;
 380                 }
 381         }
 382
 383         if (!match_cnt) {
 384                 struct object_id *oid = &cmit->object.oid;
 385                 if (always) {
 386                         printf("%s", find_unique_abbrev(oid->hash, abbrev));
 387                         if (suffix)
 388                                 printf("%s", suffix);
 389                         printf("\n");
 390                         return;
 391                 }
 392                 if (unannotated_cnt)
 393                         die(_("No annotated tags can describe '%s'.\n"
 394                             "However, there were unannotated tags: try --tags."),
 395                             oid_to_hex(oid));
 396                 else
 397                         die(_("No tags can describe '%s'.\n"
 398                             "Try --always, or create some tags."),
 399                             oid_to_hex(oid));
 400         }
 401
 402         QSORT(all_matches, match_cnt, compare_pt);
 403
 404         if (gave_up_on) {
 405                 commit_list_insert_by_date(gave_up_on, &list);
 406                 seen_commits--;
 407         }
 408         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 409         free_commit_list(list);
 410
 411         if (debug) {
 412                 static int label_width = -1;
 413                 if (label_width < 0) {
 414                         int i, w;
 415                         for (i = 0; i < ARRAY_SIZE(prio_names); i++) {
 416                                 w = strlen(_(prio_names[i]));
 417                                 if (label_width < w)
 418                                         label_width = w;
 419                         }
 420                 }
 421                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 422                         struct possible_tag *t = &all_matches[cur_match];
 423                         fprintf(stderr, " %-*s %8d %s\n",
 424                                 label_width, _(prio_names[t->name->prio]),
 425                                 t->depth, t->name->path);
 426                 }
 427                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 428                 if (gave_up_on) {
 429                         fprintf(stderr,
 430                                 _("more than %i tags found; listed %i most recent\n"
 431                                 "gave up search at %s\n"),
 432                                 max_candidates, max_candidates,
 433                                 oid_to_hex(&gave_up_on->object.oid));
 434                 }
 435         }
 436
 437         display_name(all_matches[0].name);
 438         if (abbrev)
 439                 show_suffix(all_matches[0].depth, &cmit->object.oid);
 440         if (suffix)
 441                 printf("%s", suffix);
 442         printf("\n");
 443
 444         if (!last_one)
 445                 clear_commit_marks(cmit, -1);
 446 }
 447
 448 int cmd_describe(int argc, const char **argv, const char *prefix)
 449 {
 450         int contains = 0;
 451         struct option options[] = {
 452                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 453                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
 454                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
 455                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
 456                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
 457                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
 458                 OPT__ABBREV(&abbrev),
 459                 OPT_SET_INT(0, "exact-match", &max_candidates,
 460                             N_("only output exact matches"), 0),
 461                 OPT_INTEGER(0, "candidates", &max_candidates,
 462                             N_("consider <n> most recent tags (default: 10)")),
 463                 OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),
 464                            N_("only consider tags matching <pattern>")),
 465                 OPT_STRING_LIST(0, "exclude", &exclude_patterns, N_("pattern"),
 466                            N_("do not consider tags matching <pattern>")),
 467                 OPT_BOOL(0, "always",        &always,
 468                         N_("show abbreviated commit object as fallback")),
 469                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 470                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 471                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 472                 {OPTION_STRING, 0, "broken",  &broken, N_("mark"),
 473                         N_("append <mark> on broken working tree (default: \"-broken\")"),
 474                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-broken"},
 475                 OPT_END(),
 476         };
 477
 478         git_config(git_default_config, NULL);
 479         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 480         if (abbrev < 0)
 481                 abbrev = DEFAULT_ABBREV;
 482
 483         if (max_candidates < 0)
 484                 max_candidates = 0;
 485         else if (max_candidates > MAX_TAGS)
 486                 max_candidates = MAX_TAGS;
 487
 488         save_commit_buffer = 0;
 489
 490         if (longformat && abbrev == 0)
 491                 die(_("--long is incompatible with --abbrev=0"));
 492
 493         if (contains) {
 494                 struct string_list_item *item;
 495                 struct argv_array args;
 496
 497                 argv_array_init(&args);
 498                 argv_array_pushl(&args, "name-rev",
 499                                  "--peel-tag", "--name-only", "--no-undefined",
 500                                  NULL);
 501                 if (always)
 502                         argv_array_push(&args, "--always");
 503                 if (!all) {
 504                         argv_array_push(&args, "--tags");
 505                         for_each_string_list_item(item, &patterns)
 506                                 argv_array_pushf(&args, "--refs=refs/tags/%s", item->string);
 507                         for_each_string_list_item(item, &exclude_patterns)
 508                                 argv_array_pushf(&args, "--exclude=refs/tags/%s", item->string);
 509                 }
 510                 if (argc)
 511                         argv_array_pushv(&args, argv);
 512                 else
 513                         argv_array_push(&args, "HEAD");
 514                 return cmd_name_rev(args.argc, args.argv, prefix);
 515         }
 516
 517         hashmap_init(&names, commit_name_cmp, NULL, 0);
 518         for_each_rawref(get_name, NULL);
 519         if (!hashmap_get_size(&names) && !always)
 520                 die(_("No names found, cannot describe anything."));
 521
 522         if (argc == 0) {
 523                 if (broken) {
 524                         struct child_process cp = CHILD_PROCESS_INIT;
 525                         argv_array_pushv(&cp.args, diff_index_args);
 526                         cp.git_cmd = 1;
 527                         cp.no_stdin = 1;
 528                         cp.no_stdout = 1;
 529
 530                         if (!dirty)
 531                                 dirty = "-dirty";
 532
 533                         switch (run_command(&cp)) {
 534                         case 0:
 535                                 suffix = NULL;
 536                                 break;
 537                         case 1:
 538                                 suffix = dirty;
 539                                 break;
 540                         default:
 541                                 /* diff-index aborted abnormally */
 542                                 suffix = broken;
 543                         }
 544                 } else if (dirty) {
 545                         static struct lock_file index_lock;
 546                         int fd;
 547
 548                         read_cache_preload(NULL);
 549                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 550                                       NULL, NULL, NULL);
 551                         fd = hold_locked_index(&index_lock, 0);
 552                         if (0 <= fd)
 553                                 update_index_if_able(&the_index, &index_lock);
 554
 555                         if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
 556                                             diff_index_args, prefix))
 557                                 suffix = NULL;
 558                         else
 559                                 suffix = dirty;
 560                 }
 561                 describe("HEAD", 1);
 562         } else if (dirty) {
 563                 die(_("--dirty is incompatible with commit-ishes"));
 564         } else if (broken) {
 565                 die(_("--broken is incompatible with commit-ishes"));
 566         } else {
 567                 while (argc-- > 0)
 568                         describe(*argv++, argc == 0);
 569         }
 570         return 0;
 571 }