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 "blob.h"
   7 #include "refs.h"
   8 #include "builtin.h"
   9 #include "exec-cmd.h"
  10 #include "parse-options.h"
  11 #include "revision.h"
  12 #include "diff.h"
  13 #include "hashmap.h"
  14 #include "argv-array.h"
  15 #include "run-command.h"
  16 #include "object-store.h"
  17 #include "revision.h"
  18 #include "list-objects.h"
  19 #include "commit-slab.h"
  20
  21 #define MAX_TAGS        (FLAG_BITS - 1)
  22
  23 define_commit_slab(commit_names, struct commit_name *);
  24
  25 static const char * const describe_usage[] = {
  26         N_("git describe [<options>] [<commit-ish>...]"),
  27         N_("git describe [<options>] --dirty"),
  28         NULL
  29 };
  30
  31 static int debug;       /* Display lots of verbose info */
  32 static int all; /* Any valid ref can be used */
  33 static int tags;        /* Allow lightweight tags */
  34 static int longformat;
  35 static int first_parent;
  36 static int abbrev = -1; /* unspecified */
  37 static int max_candidates = 10;
  38 static struct hashmap names;
  39 static int have_util;
  40 static struct string_list patterns = STRING_LIST_INIT_NODUP;
  41 static struct string_list exclude_patterns = STRING_LIST_INIT_NODUP;
  42 static int always;
  43 static const char *suffix, *dirty, *broken;
  44 static struct commit_names commit_names;
  45
  46 /* diff-index command arguments to check if working tree is dirty. */
  47 static const char *diff_index_args[] = {
  48         "diff-index", "--quiet", "HEAD", "--", NULL
  49 };
  50
  51 struct commit_name {
  52         struct hashmap_entry entry;
  53         struct object_id peeled;
  54         struct tag *tag;
  55         unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  56         unsigned name_checked:1;
  57         struct object_id oid;
  58         char *path;
  59 };
  60
  61 static const char *prio_names[] = {
  62         N_("head"), N_("lightweight"), N_("annotated"),
  63 };
  64
  65 static int commit_name_neq(const void *unused_cmp_data,
  66                            const void *entry,
  67                            const void *entry_or_key,
  68                            const void *peeled)
  69 {
  70         const struct commit_name *cn1 = entry;
  71         const struct commit_name *cn2 = entry_or_key;
  72
  73         return !oideq(&cn1->peeled, peeled ? peeled : &cn2->peeled);
  74 }
  75
  76 static inline struct commit_name *find_commit_name(const struct object_id *peeled)
  77 {
  78         return hashmap_get_from_hash(&names, sha1hash(peeled->hash), peeled->hash);
  79 }
  80
  81 static int replace_name(struct commit_name *e,
  82                                int prio,
  83                                const struct object_id *oid,
  84                                struct tag **tag)
  85 {
  86         if (!e || e->prio < prio)
  87                 return 1;
  88
  89         if (e->prio == 2 && prio == 2) {
  90                 /* Multiple annotated tags point to the same commit.
  91                  * Select one to keep based upon their tagger date.
  92                  */
  93                 struct tag *t;
  94
  95                 if (!e->tag) {
  96                         t = lookup_tag(the_repository, &e->oid);
  97                         if (!t || parse_tag(t))
  98                                 return 1;
  99                         e->tag = t;
 100                 }
 101
 102                 t = lookup_tag(the_repository, oid);
 103                 if (!t || parse_tag(t))
 104                         return 0;
 105                 *tag = t;
 106
 107                 if (e->tag->date < t->date)
 108                         return 1;
 109         }
 110
 111         return 0;
 112 }
 113
 114 static void add_to_known_names(const char *path,
 115                                const struct object_id *peeled,
 116                                int prio,
 117                                const struct object_id *oid)
 118 {
 119         struct commit_name *e = find_commit_name(peeled);
 120         struct tag *tag = NULL;
 121         if (replace_name(e, prio, oid, &tag)) {
 122                 if (!e) {
 123                         e = xmalloc(sizeof(struct commit_name));
 124                         oidcpy(&e->peeled, peeled);
 125                         hashmap_entry_init(e, sha1hash(peeled->hash));
 126                         hashmap_add(&names, e);
 127                         e->path = NULL;
 128                 }
 129                 e->tag = tag;
 130                 e->prio = prio;
 131                 e->name_checked = 0;
 132                 oidcpy(&e->oid, oid);
 133                 free(e->path);
 134                 e->path = xstrdup(path);
 135         }
 136 }
 137
 138 static int get_name(const char *path, const struct object_id *oid, int flag, void *cb_data)
 139 {
 140         int is_tag = 0;
 141         struct object_id peeled;
 142         int is_annotated, prio;
 143         const char *path_to_match = NULL;
 144
 145         if (skip_prefix(path, "refs/tags/", &path_to_match)) {
 146                 is_tag = 1;
 147         } else if (all) {
 148                 if ((exclude_patterns.nr || patterns.nr) &&
 149                     !skip_prefix(path, "refs/heads/", &path_to_match) &&
 150                     !skip_prefix(path, "refs/remotes/", &path_to_match)) {
 151                         /* Only accept reference of known type if there are match/exclude patterns */
 152                         return 0;
 153                 }
 154         } else {
 155                 /* Reject anything outside refs/tags/ unless --all */
 156                 return 0;
 157         }
 158
 159         /*
 160          * If we're given exclude patterns, first exclude any tag which match
 161          * any of the exclude pattern.
 162          */
 163         if (exclude_patterns.nr) {
 164                 struct string_list_item *item;
 165
 166                 for_each_string_list_item(item, &exclude_patterns) {
 167                         if (!wildmatch(item->string, path_to_match, 0))
 168                                 return 0;
 169                 }
 170         }
 171
 172         /*
 173          * If we're given patterns, accept only tags which match at least one
 174          * pattern.
 175          */
 176         if (patterns.nr) {
 177                 int found = 0;
 178                 struct string_list_item *item;
 179
 180                 for_each_string_list_item(item, &patterns) {
 181                         if (!wildmatch(item->string, path_to_match, 0)) {
 182                                 found = 1;
 183                                 break;
 184                         }
 185                 }
 186
 187                 if (!found)
 188                         return 0;
 189         }
 190
 191         /* Is it annotated? */
 192         if (!peel_ref(path, &peeled)) {
 193                 is_annotated = !oideq(oid, &peeled);
 194         } else {
 195                 oidcpy(&peeled, oid);
 196                 is_annotated = 0;
 197         }
 198
 199         /*
 200          * By default, we only use annotated tags, but with --tags
 201          * we fall back to lightweight ones (even without --tags,
 202          * we still remember lightweight ones, only to give hints
 203          * in an error message).  --all allows any refs to be used.
 204          */
 205         if (is_annotated)
 206                 prio = 2;
 207         else if (is_tag)
 208                 prio = 1;
 209         else
 210                 prio = 0;
 211
 212         add_to_known_names(all ? path + 5 : path + 10, &peeled, prio, oid);
 213         return 0;
 214 }
 215
 216 struct possible_tag {
 217         struct commit_name *name;
 218         int depth;
 219         int found_order;
 220         unsigned flag_within;
 221 };
 222
 223 static int compare_pt(const void *a_, const void *b_)
 224 {
 225         struct possible_tag *a = (struct possible_tag *)a_;
 226         struct possible_tag *b = (struct possible_tag *)b_;
 227         if (a->depth != b->depth)
 228                 return a->depth - b->depth;
 229         if (a->found_order != b->found_order)
 230                 return a->found_order - b->found_order;
 231         return 0;
 232 }
 233
 234 static unsigned long finish_depth_computation(
 235         struct commit_list **list,
 236         struct possible_tag *best)
 237 {
 238         unsigned long seen_commits = 0;
 239         while (*list) {
 240                 struct commit *c = pop_commit(list);
 241                 struct commit_list *parents = c->parents;
 242                 seen_commits++;
 243                 if (c->object.flags & best->flag_within) {
 244                         struct commit_list *a = *list;
 245                         while (a) {
 246                                 struct commit *i = a->item;
 247                                 if (!(i->object.flags & best->flag_within))
 248                                         break;
 249                                 a = a->next;
 250                         }
 251                         if (!a)
 252                                 break;
 253                 } else
 254                         best->depth++;
 255                 while (parents) {
 256                         struct commit *p = parents->item;
 257                         parse_commit(p);
 258                         if (!(p->object.flags & SEEN))
 259                                 commit_list_insert_by_date(p, list);
 260                         p->object.flags |= c->object.flags;
 261                         parents = parents->next;
 262                 }
 263         }
 264         return seen_commits;
 265 }
 266
 267 static void append_name(struct commit_name *n, struct strbuf *dst)
 268 {
 269         if (n->prio == 2 && !n->tag) {
 270                 n->tag = lookup_tag(the_repository, &n->oid);
 271                 if (!n->tag || parse_tag(n->tag))
 272                         die(_("annotated tag %s not available"), n->path);
 273         }
 274         if (n->tag && !n->name_checked) {
 275                 if (!n->tag->tag)
 276                         die(_("annotated tag %s has no embedded name"), n->path);
 277                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 278                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 279                 n->name_checked = 1;
 280         }
 281
 282         if (n->tag) {
 283                 if (all)
 284                         strbuf_addstr(dst, "tags/");
 285                 strbuf_addstr(dst, n->tag->tag);
 286         } else {
 287                 strbuf_addstr(dst, n->path);
 288         }
 289 }
 290
 291 static void append_suffix(int depth, const struct object_id *oid, struct strbuf *dst)
 292 {
 293         strbuf_addf(dst, "-%d-g%s", depth, find_unique_abbrev(oid, abbrev));
 294 }
 295
 296 static void describe_commit(struct object_id *oid, struct strbuf *dst)
 297 {
 298         struct commit *cmit, *gave_up_on = NULL;
 299         struct commit_list *list;
 300         struct commit_name *n;
 301         struct possible_tag all_matches[MAX_TAGS];
 302         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 303         unsigned long seen_commits = 0;
 304         unsigned int unannotated_cnt = 0;
 305
 306         cmit = lookup_commit_reference(the_repository, oid);
 307
 308         n = find_commit_name(&cmit->object.oid);
 309         if (n && (tags || all || n->prio == 2)) {
 310                 /*
 311                  * Exact match to an existing ref.
 312                  */
 313                 append_name(n, dst);
 314                 if (longformat)
 315                         append_suffix(0, n->tag ? &n->tag->tagged->oid : oid, dst);
 316                 if (suffix)
 317                         strbuf_addstr(dst, suffix);
 318                 return;
 319         }
 320
 321         if (!max_candidates)
 322                 die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));
 323         if (debug)
 324                 fprintf(stderr, _("No exact match on refs or tags, searching to describe\n"));
 325
 326         if (!have_util) {
 327                 struct hashmap_iter iter;
 328                 struct commit *c;
 329                 struct commit_name *n;
 330
 331                 init_commit_names(&commit_names);
 332                 n = hashmap_iter_first(&names, &iter);
 333                 for (; n; n = hashmap_iter_next(&iter)) {
 334                         c = lookup_commit_reference_gently(the_repository,
 335                                                            &n->peeled, 1);
 336                         if (c)
 337                                 *commit_names_at(&commit_names, c) = n;
 338                 }
 339                 have_util = 1;
 340         }
 341
 342         list = NULL;
 343         cmit->object.flags = SEEN;
 344         commit_list_insert(cmit, &list);
 345         while (list) {
 346                 struct commit *c = pop_commit(&list);
 347                 struct commit_list *parents = c->parents;
 348                 struct commit_name **slot;
 349
 350                 seen_commits++;
 351                 slot = commit_names_peek(&commit_names, c);
 352                 n = slot ? *slot : NULL;
 353                 if (n) {
 354                         if (!tags && !all && n->prio < 2) {
 355                                 unannotated_cnt++;
 356                         } else if (match_cnt < max_candidates) {
 357                                 struct possible_tag *t = &all_matches[match_cnt++];
 358                                 t->name = n;
 359                                 t->depth = seen_commits - 1;
 360                                 t->flag_within = 1u << match_cnt;
 361                                 t->found_order = match_cnt;
 362                                 c->object.flags |= t->flag_within;
 363                                 if (n->prio == 2)
 364                                         annotated_cnt++;
 365                         }
 366                         else {
 367                                 gave_up_on = c;
 368                                 break;
 369                         }
 370                 }
 371                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 372                         struct possible_tag *t = &all_matches[cur_match];
 373                         if (!(c->object.flags & t->flag_within))
 374                                 t->depth++;
 375                 }
 376                 if (annotated_cnt && !list) {
 377                         if (debug)
 378                                 fprintf(stderr, _("finished search at %s\n"),
 379                                         oid_to_hex(&c->object.oid));
 380                         break;
 381                 }
 382                 while (parents) {
 383                         struct commit *p = parents->item;
 384                         parse_commit(p);
 385                         if (!(p->object.flags & SEEN))
 386                                 commit_list_insert_by_date(p, &list);
 387                         p->object.flags |= c->object.flags;
 388                         parents = parents->next;
 389
 390                         if (first_parent)
 391                                 break;
 392                 }
 393         }
 394
 395         if (!match_cnt) {
 396                 struct object_id *cmit_oid = &cmit->object.oid;
 397                 if (always) {
 398                         strbuf_add_unique_abbrev(dst, cmit_oid, abbrev);
 399                         if (suffix)
 400                                 strbuf_addstr(dst, suffix);
 401                         return;
 402                 }
 403                 if (unannotated_cnt)
 404                         die(_("No annotated tags can describe '%s'.\n"
 405                             "However, there were unannotated tags: try --tags."),
 406                             oid_to_hex(cmit_oid));
 407                 else
 408                         die(_("No tags can describe '%s'.\n"
 409                             "Try --always, or create some tags."),
 410                             oid_to_hex(cmit_oid));
 411         }
 412
 413         QSORT(all_matches, match_cnt, compare_pt);
 414
 415         if (gave_up_on) {
 416                 commit_list_insert_by_date(gave_up_on, &list);
 417                 seen_commits--;
 418         }
 419         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 420         free_commit_list(list);
 421
 422         if (debug) {
 423                 static int label_width = -1;
 424                 if (label_width < 0) {
 425                         int i, w;
 426                         for (i = 0; i < ARRAY_SIZE(prio_names); i++) {
 427                                 w = strlen(_(prio_names[i]));
 428                                 if (label_width < w)
 429                                         label_width = w;
 430                         }
 431                 }
 432                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 433                         struct possible_tag *t = &all_matches[cur_match];
 434                         fprintf(stderr, " %-*s %8d %s\n",
 435                                 label_width, _(prio_names[t->name->prio]),
 436                                 t->depth, t->name->path);
 437                 }
 438                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 439                 if (gave_up_on) {
 440                         fprintf(stderr,
 441                                 _("more than %i tags found; listed %i most recent\n"
 442                                 "gave up search at %s\n"),
 443                                 max_candidates, max_candidates,
 444                                 oid_to_hex(&gave_up_on->object.oid));
 445                 }
 446         }
 447
 448         append_name(all_matches[0].name, dst);
 449         if (abbrev)
 450                 append_suffix(all_matches[0].depth, &cmit->object.oid, dst);
 451         if (suffix)
 452                 strbuf_addstr(dst, suffix);
 453 }
 454
 455 struct process_commit_data {
 456         struct object_id current_commit;
 457         struct object_id looking_for;
 458         struct strbuf *dst;
 459         struct rev_info *revs;
 460 };
 461
 462 static void process_commit(struct commit *commit, void *data)
 463 {
 464         struct process_commit_data *pcd = data;
 465         pcd->current_commit = commit->object.oid;
 466 }
 467
 468 static void process_object(struct object *obj, const char *path, void *data)
 469 {
 470         struct process_commit_data *pcd = data;
 471
 472         if (oideq(&pcd->looking_for, &obj->oid) && !pcd->dst->len) {
 473                 reset_revision_walk();
 474                 describe_commit(&pcd->current_commit, pcd->dst);
 475                 strbuf_addf(pcd->dst, ":%s", path);
 476                 free_commit_list(pcd->revs->commits);
 477                 pcd->revs->commits = NULL;
 478         }
 479 }
 480
 481 static void describe_blob(struct object_id oid, struct strbuf *dst)
 482 {
 483         struct rev_info revs;
 484         struct argv_array args = ARGV_ARRAY_INIT;
 485         struct process_commit_data pcd = { null_oid, oid, dst, &revs};
 486
 487         argv_array_pushl(&args, "internal: The first arg is not parsed",
 488                 "--objects", "--in-commit-order", "--reverse", "HEAD",
 489                 NULL);
 490
 491         repo_init_revisions(the_repository, &revs, NULL);
 492         if (setup_revisions(args.argc, args.argv, &revs, NULL) > 1)
 493                 BUG("setup_revisions could not handle all args?");
 494
 495         if (prepare_revision_walk(&revs))
 496                 die("revision walk setup failed");
 497
 498         traverse_commit_list(&revs, process_commit, process_object, &pcd);
 499         reset_revision_walk();
 500 }
 501
 502 static void describe(const char *arg, int last_one)
 503 {
 504         struct object_id oid;
 505         struct commit *cmit;
 506         struct strbuf sb = STRBUF_INIT;
 507
 508         if (debug)
 509                 fprintf(stderr, _("describe %s\n"), arg);
 510
 511         if (get_oid(arg, &oid))
 512                 die(_("Not a valid object name %s"), arg);
 513         cmit = lookup_commit_reference_gently(the_repository, &oid, 1);
 514
 515         if (cmit)
 516                 describe_commit(&oid, &sb);
 517         else if (oid_object_info(the_repository, &oid, NULL) == OBJ_BLOB)
 518                 describe_blob(oid, &sb);
 519         else
 520                 die(_("%s is neither a commit nor blob"), arg);
 521
 522         puts(sb.buf);
 523
 524         if (!last_one)
 525                 clear_commit_marks(cmit, -1);
 526
 527         strbuf_release(&sb);
 528 }
 529
 530 int cmd_describe(int argc, const char **argv, const char *prefix)
 531 {
 532         int contains = 0;
 533         struct option options[] = {
 534                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 535                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
 536                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
 537                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
 538                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
 539                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
 540                 OPT__ABBREV(&abbrev),
 541                 OPT_SET_INT(0, "exact-match", &max_candidates,
 542                             N_("only output exact matches"), 0),
 543                 OPT_INTEGER(0, "candidates", &max_candidates,
 544                             N_("consider <n> most recent tags (default: 10)")),
 545                 OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),
 546                            N_("only consider tags matching <pattern>")),
 547                 OPT_STRING_LIST(0, "exclude", &exclude_patterns, N_("pattern"),
 548                            N_("do not consider tags matching <pattern>")),
 549                 OPT_BOOL(0, "always",        &always,
 550                         N_("show abbreviated commit object as fallback")),
 551                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 552                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 553                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 554                 {OPTION_STRING, 0, "broken",  &broken, N_("mark"),
 555                         N_("append <mark> on broken working tree (default: \"-broken\")"),
 556                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-broken"},
 557                 OPT_END(),
 558         };
 559
 560         git_config(git_default_config, NULL);
 561         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 562         if (abbrev < 0)
 563                 abbrev = DEFAULT_ABBREV;
 564
 565         if (max_candidates < 0)
 566                 max_candidates = 0;
 567         else if (max_candidates > MAX_TAGS)
 568                 max_candidates = MAX_TAGS;
 569
 570         save_commit_buffer = 0;
 571
 572         if (longformat && abbrev == 0)
 573                 die(_("--long is incompatible with --abbrev=0"));
 574
 575         if (contains) {
 576                 struct string_list_item *item;
 577                 struct argv_array args;
 578
 579                 argv_array_init(&args);
 580                 argv_array_pushl(&args, "name-rev",
 581                                  "--peel-tag", "--name-only", "--no-undefined",
 582                                  NULL);
 583                 if (always)
 584                         argv_array_push(&args, "--always");
 585                 if (!all) {
 586                         argv_array_push(&args, "--tags");
 587                         for_each_string_list_item(item, &patterns)
 588                                 argv_array_pushf(&args, "--refs=refs/tags/%s", item->string);
 589                         for_each_string_list_item(item, &exclude_patterns)
 590                                 argv_array_pushf(&args, "--exclude=refs/tags/%s", item->string);
 591                 }
 592                 if (argc)
 593                         argv_array_pushv(&args, argv);
 594                 else
 595                         argv_array_push(&args, "HEAD");
 596                 return cmd_name_rev(args.argc, args.argv, prefix);
 597         }
 598
 599         hashmap_init(&names, commit_name_neq, NULL, 0);
 600         for_each_rawref(get_name, NULL);
 601         if (!hashmap_get_size(&names) && !always)
 602                 die(_("No names found, cannot describe anything."));
 603
 604         if (argc == 0) {
 605                 if (broken) {
 606                         struct child_process cp = CHILD_PROCESS_INIT;
 607                         argv_array_pushv(&cp.args, diff_index_args);
 608                         cp.git_cmd = 1;
 609                         cp.no_stdin = 1;
 610                         cp.no_stdout = 1;
 611
 612                         if (!dirty)
 613                                 dirty = "-dirty";
 614
 615                         switch (run_command(&cp)) {
 616                         case 0:
 617                                 suffix = NULL;
 618                                 break;
 619                         case 1:
 620                                 suffix = dirty;
 621                                 break;
 622                         default:
 623                                 /* diff-index aborted abnormally */
 624                                 suffix = broken;
 625                         }
 626                 } else if (dirty) {
 627                         struct lock_file index_lock = LOCK_INIT;
 628                         struct rev_info revs;
 629                         struct argv_array args = ARGV_ARRAY_INIT;
 630                         int fd, result;
 631
 632                         read_cache_preload(NULL);
 633                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 634                                       NULL, NULL, NULL);
 635                         fd = hold_locked_index(&index_lock, 0);
 636                         if (0 <= fd)
 637                                 update_index_if_able(&the_index, &index_lock);
 638
 639                         repo_init_revisions(the_repository, &revs, prefix);
 640                         argv_array_pushv(&args, diff_index_args);
 641                         if (setup_revisions(args.argc, args.argv, &revs, NULL) != 1)
 642                                 BUG("malformed internal diff-index command line");
 643                         result = run_diff_index(&revs, 0);
 644
 645                         if (!diff_result_code(&revs.diffopt, result))
 646                                 suffix = NULL;
 647                         else
 648                                 suffix = dirty;
 649                 }
 650                 describe("HEAD", 1);
 651         } else if (dirty) {
 652                 die(_("--dirty is incompatible with commit-ishes"));
 653         } else if (broken) {
 654                 die(_("--broken is incompatible with commit-ishes"));
 655         } else {
 656                 while (argc-- > 0)
 657                         describe(*argv++, argc == 0);
 658         }
 659         return 0;
 660 }