builtin/describe.c

   1 #define USE_THE_INDEX_VARIABLE
   2 #include "cache.h"
   3 #include "config.h"
   4 #include "environment.h"
   5 #include "gettext.h"
   6 #include "hex.h"
   7 #include "lockfile.h"
   8 #include "commit.h"
   9 #include "tag.h"
  10 #include "blob.h"
  11 #include "refs.h"
  12 #include "builtin.h"
  13 #include "exec-cmd.h"
  14 #include "object-name.h"
  15 #include "parse-options.h"
  16 #include "revision.h"
  17 #include "diff.h"
  18 #include "hashmap.h"
  19 #include "setup.h"
  20 #include "strvec.h"
  21 #include "run-command.h"
  22 #include "object-store.h"
  23 #include "list-objects.h"
  24 #include "commit-slab.h"
  25
  26 #define MAX_TAGS        (FLAG_BITS - 1)
  27
  28 define_commit_slab(commit_names, struct commit_name *);
  29
  30 static const char * const describe_usage[] = {
  31         N_("git describe [--all] [--tags] [--contains] [--abbrev=<n>] [<commit-ish>...]"),
  32         N_("git describe [--all] [--tags] [--contains] [--abbrev=<n>] --dirty[=<mark>]"),
  33         N_("git describe <blob>"),
  34         NULL
  35 };
  36
  37 static int debug;       /* Display lots of verbose info */
  38 static int all; /* Any valid ref can be used */
  39 static int tags;        /* Allow lightweight tags */
  40 static int longformat;
  41 static int first_parent;
  42 static int abbrev = -1; /* unspecified */
  43 static int max_candidates = 10;
  44 static struct hashmap names;
  45 static int have_util;
  46 static struct string_list patterns = STRING_LIST_INIT_NODUP;
  47 static struct string_list exclude_patterns = STRING_LIST_INIT_NODUP;
  48 static int always;
  49 static const char *suffix, *dirty, *broken;
  50 static struct commit_names commit_names;
  51
  52 /* diff-index command arguments to check if working tree is dirty. */
  53 static const char *diff_index_args[] = {
  54         "diff-index", "--quiet", "HEAD", "--", NULL
  55 };
  56
  57 struct commit_name {
  58         struct hashmap_entry entry;
  59         struct object_id peeled;
  60         struct tag *tag;
  61         unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  62         unsigned name_checked:1;
  63         unsigned misnamed:1;
  64         struct object_id oid;
  65         char *path;
  66 };
  67
  68 static const char *prio_names[] = {
  69         N_("head"), N_("lightweight"), N_("annotated"),
  70 };
  71
  72 static int commit_name_neq(const void *cmp_data UNUSED,
  73                            const struct hashmap_entry *eptr,
  74                            const struct hashmap_entry *entry_or_key,
  75                            const void *peeled)
  76 {
  77         const struct commit_name *cn1, *cn2;
  78
  79         cn1 = container_of(eptr, const struct commit_name, entry);
  80         cn2 = container_of(entry_or_key, const struct commit_name, entry);
  81
  82         return !oideq(&cn1->peeled, peeled ? peeled : &cn2->peeled);
  83 }
  84
  85 static inline struct commit_name *find_commit_name(const struct object_id *peeled)
  86 {
  87         return hashmap_get_entry_from_hash(&names, oidhash(peeled), peeled,
  88                                                 struct commit_name, entry);
  89 }
  90
  91 static int replace_name(struct commit_name *e,
  92                                int prio,
  93                                const struct object_id *oid,
  94                                struct tag **tag)
  95 {
  96         if (!e || e->prio < prio)
  97                 return 1;
  98
  99         if (e->prio == 2 && prio == 2) {
 100                 /* Multiple annotated tags point to the same commit.
 101                  * Select one to keep based upon their tagger date.
 102                  */
 103                 struct tag *t;
 104
 105                 if (!e->tag) {
 106                         t = lookup_tag(the_repository, &e->oid);
 107                         if (!t || parse_tag(t))
 108                                 return 1;
 109                         e->tag = t;
 110                 }
 111
 112                 t = lookup_tag(the_repository, oid);
 113                 if (!t || parse_tag(t))
 114                         return 0;
 115                 *tag = t;
 116
 117                 if (e->tag->date < t->date)
 118                         return 1;
 119         }
 120
 121         return 0;
 122 }
 123
 124 static void add_to_known_names(const char *path,
 125                                const struct object_id *peeled,
 126                                int prio,
 127                                const struct object_id *oid)
 128 {
 129         struct commit_name *e = find_commit_name(peeled);
 130         struct tag *tag = NULL;
 131         if (replace_name(e, prio, oid, &tag)) {
 132                 if (!e) {
 133                         e = xmalloc(sizeof(struct commit_name));
 134                         oidcpy(&e->peeled, peeled);
 135                         hashmap_entry_init(&e->entry, oidhash(peeled));
 136                         hashmap_add(&names, &e->entry);
 137                         e->path = NULL;
 138                 }
 139                 e->tag = tag;
 140                 e->prio = prio;
 141                 e->name_checked = 0;
 142                 e->misnamed = 0;
 143                 oidcpy(&e->oid, oid);
 144                 free(e->path);
 145                 e->path = xstrdup(path);
 146         }
 147 }
 148
 149 static int get_name(const char *path, const struct object_id *oid,
 150                     int flag UNUSED, void *cb_data UNUSED)
 151 {
 152         int is_tag = 0;
 153         struct object_id peeled;
 154         int is_annotated, prio;
 155         const char *path_to_match = NULL;
 156
 157         if (skip_prefix(path, "refs/tags/", &path_to_match)) {
 158                 is_tag = 1;
 159         } else if (all) {
 160                 if ((exclude_patterns.nr || patterns.nr) &&
 161                     !skip_prefix(path, "refs/heads/", &path_to_match) &&
 162                     !skip_prefix(path, "refs/remotes/", &path_to_match)) {
 163                         /* Only accept reference of known type if there are match/exclude patterns */
 164                         return 0;
 165                 }
 166         } else {
 167                 /* Reject anything outside refs/tags/ unless --all */
 168                 return 0;
 169         }
 170
 171         /*
 172          * If we're given exclude patterns, first exclude any tag which match
 173          * any of the exclude pattern.
 174          */
 175         if (exclude_patterns.nr) {
 176                 struct string_list_item *item;
 177
 178                 for_each_string_list_item(item, &exclude_patterns) {
 179                         if (!wildmatch(item->string, path_to_match, 0))
 180                                 return 0;
 181                 }
 182         }
 183
 184         /*
 185          * If we're given patterns, accept only tags which match at least one
 186          * pattern.
 187          */
 188         if (patterns.nr) {
 189                 int found = 0;
 190                 struct string_list_item *item;
 191
 192                 for_each_string_list_item(item, &patterns) {
 193                         if (!wildmatch(item->string, path_to_match, 0)) {
 194                                 found = 1;
 195                                 break;
 196                         }
 197                 }
 198
 199                 if (!found)
 200                         return 0;
 201         }
 202
 203         /* Is it annotated? */
 204         if (!peel_iterated_oid(oid, &peeled)) {
 205                 is_annotated = !oideq(oid, &peeled);
 206         } else {
 207                 oidcpy(&peeled, oid);
 208                 is_annotated = 0;
 209         }
 210
 211         /*
 212          * By default, we only use annotated tags, but with --tags
 213          * we fall back to lightweight ones (even without --tags,
 214          * we still remember lightweight ones, only to give hints
 215          * in an error message).  --all allows any refs to be used.
 216          */
 217         if (is_annotated)
 218                 prio = 2;
 219         else if (is_tag)
 220                 prio = 1;
 221         else
 222                 prio = 0;
 223
 224         add_to_known_names(all ? path + 5 : path + 10, &peeled, prio, oid);
 225         return 0;
 226 }
 227
 228 struct possible_tag {
 229         struct commit_name *name;
 230         int depth;
 231         int found_order;
 232         unsigned flag_within;
 233 };
 234
 235 static int compare_pt(const void *a_, const void *b_)
 236 {
 237         struct possible_tag *a = (struct possible_tag *)a_;
 238         struct possible_tag *b = (struct possible_tag *)b_;
 239         if (a->depth != b->depth)
 240                 return a->depth - b->depth;
 241         if (a->found_order != b->found_order)
 242                 return a->found_order - b->found_order;
 243         return 0;
 244 }
 245
 246 static unsigned long finish_depth_computation(
 247         struct commit_list **list,
 248         struct possible_tag *best)
 249 {
 250         unsigned long seen_commits = 0;
 251         while (*list) {
 252                 struct commit *c = pop_commit(list);
 253                 struct commit_list *parents = c->parents;
 254                 seen_commits++;
 255                 if (c->object.flags & best->flag_within) {
 256                         struct commit_list *a = *list;
 257                         while (a) {
 258                                 struct commit *i = a->item;
 259                                 if (!(i->object.flags & best->flag_within))
 260                                         break;
 261                                 a = a->next;
 262                         }
 263                         if (!a)
 264                                 break;
 265                 } else
 266                         best->depth++;
 267                 while (parents) {
 268                         struct commit *p = parents->item;
 269                         repo_parse_commit(the_repository, p);
 270                         if (!(p->object.flags & SEEN))
 271                                 commit_list_insert_by_date(p, list);
 272                         p->object.flags |= c->object.flags;
 273                         parents = parents->next;
 274                 }
 275         }
 276         return seen_commits;
 277 }
 278
 279 static void append_name(struct commit_name *n, struct strbuf *dst)
 280 {
 281         if (n->prio == 2 && !n->tag) {
 282                 n->tag = lookup_tag(the_repository, &n->oid);
 283                 if (!n->tag || parse_tag(n->tag))
 284                         die(_("annotated tag %s not available"), n->path);
 285         }
 286         if (n->tag && !n->name_checked) {
 287                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path)) {
 288                         warning(_("tag '%s' is externally known as '%s'"),
 289                                 n->path, n->tag->tag);
 290                         n->misnamed = 1;
 291                 }
 292                 n->name_checked = 1;
 293         }
 294
 295         if (n->tag) {
 296                 if (all)
 297                         strbuf_addstr(dst, "tags/");
 298                 strbuf_addstr(dst, n->tag->tag);
 299         } else {
 300                 strbuf_addstr(dst, n->path);
 301         }
 302 }
 303
 304 static void append_suffix(int depth, const struct object_id *oid, struct strbuf *dst)
 305 {
 306         strbuf_addf(dst, "-%d-g%s", depth,
 307                     repo_find_unique_abbrev(the_repository, oid, abbrev));
 308 }
 309
 310 static void describe_commit(struct object_id *oid, struct strbuf *dst)
 311 {
 312         struct commit *cmit, *gave_up_on = NULL;
 313         struct commit_list *list;
 314         struct commit_name *n;
 315         struct possible_tag all_matches[MAX_TAGS];
 316         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 317         unsigned long seen_commits = 0;
 318         unsigned int unannotated_cnt = 0;
 319
 320         cmit = lookup_commit_reference(the_repository, oid);
 321
 322         n = find_commit_name(&cmit->object.oid);
 323         if (n && (tags || all || n->prio == 2)) {
 324                 /*
 325                  * Exact match to an existing ref.
 326                  */
 327                 append_name(n, dst);
 328                 if (n->misnamed || longformat)
 329                         append_suffix(0, n->tag ? get_tagged_oid(n->tag) : oid, dst);
 330                 if (suffix)
 331                         strbuf_addstr(dst, suffix);
 332                 return;
 333         }
 334
 335         if (!max_candidates)
 336                 die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));
 337         if (debug)
 338                 fprintf(stderr, _("No exact match on refs or tags, searching to describe\n"));
 339
 340         if (!have_util) {
 341                 struct hashmap_iter iter;
 342                 struct commit *c;
 343                 struct commit_name *n;
 344
 345                 init_commit_names(&commit_names);
 346                 hashmap_for_each_entry(&names, &iter, n,
 347                                         entry /* member name */) {
 348                         c = lookup_commit_reference_gently(the_repository,
 349                                                            &n->peeled, 1);
 350                         if (c)
 351                                 *commit_names_at(&commit_names, c) = n;
 352                 }
 353                 have_util = 1;
 354         }
 355
 356         list = NULL;
 357         cmit->object.flags = SEEN;
 358         commit_list_insert(cmit, &list);
 359         while (list) {
 360                 struct commit *c = pop_commit(&list);
 361                 struct commit_list *parents = c->parents;
 362                 struct commit_name **slot;
 363
 364                 seen_commits++;
 365                 slot = commit_names_peek(&commit_names, c);
 366                 n = slot ? *slot : NULL;
 367                 if (n) {
 368                         if (!tags && !all && n->prio < 2) {
 369                                 unannotated_cnt++;
 370                         } else if (match_cnt < max_candidates) {
 371                                 struct possible_tag *t = &all_matches[match_cnt++];
 372                                 t->name = n;
 373                                 t->depth = seen_commits - 1;
 374                                 t->flag_within = 1u << match_cnt;
 375                                 t->found_order = match_cnt;
 376                                 c->object.flags |= t->flag_within;
 377                                 if (n->prio == 2)
 378                                         annotated_cnt++;
 379                         }
 380                         else {
 381                                 gave_up_on = c;
 382                                 break;
 383                         }
 384                 }
 385                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 386                         struct possible_tag *t = &all_matches[cur_match];
 387                         if (!(c->object.flags & t->flag_within))
 388                                 t->depth++;
 389                 }
 390                 /* Stop if last remaining path already covered by best candidate(s) */
 391                 if (annotated_cnt && !list) {
 392                         int best_depth = INT_MAX;
 393                         unsigned best_within = 0;
 394                         for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 395                                 struct possible_tag *t = &all_matches[cur_match];
 396                                 if (t->depth < best_depth) {
 397                                         best_depth = t->depth;
 398                                         best_within = t->flag_within;
 399                                 } else if (t->depth == best_depth) {
 400                                         best_within |= t->flag_within;
 401                                 }
 402                         }
 403                         if ((c->object.flags & best_within) == best_within) {
 404                                 if (debug)
 405                                         fprintf(stderr, _("finished search at %s\n"),
 406                                                 oid_to_hex(&c->object.oid));
 407                                 break;
 408                         }
 409                 }
 410                 while (parents) {
 411                         struct commit *p = parents->item;
 412                         repo_parse_commit(the_repository, p);
 413                         if (!(p->object.flags & SEEN))
 414                                 commit_list_insert_by_date(p, &list);
 415                         p->object.flags |= c->object.flags;
 416                         parents = parents->next;
 417
 418                         if (first_parent)
 419                                 break;
 420                 }
 421         }
 422
 423         if (!match_cnt) {
 424                 struct object_id *cmit_oid = &cmit->object.oid;
 425                 if (always) {
 426                         strbuf_add_unique_abbrev(dst, cmit_oid, abbrev);
 427                         if (suffix)
 428                                 strbuf_addstr(dst, suffix);
 429                         return;
 430                 }
 431                 if (unannotated_cnt)
 432                         die(_("No annotated tags can describe '%s'.\n"
 433                             "However, there were unannotated tags: try --tags."),
 434                             oid_to_hex(cmit_oid));
 435                 else
 436                         die(_("No tags can describe '%s'.\n"
 437                             "Try --always, or create some tags."),
 438                             oid_to_hex(cmit_oid));
 439         }
 440
 441         QSORT(all_matches, match_cnt, compare_pt);
 442
 443         if (gave_up_on) {
 444                 commit_list_insert_by_date(gave_up_on, &list);
 445                 seen_commits--;
 446         }
 447         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 448         free_commit_list(list);
 449
 450         if (debug) {
 451                 static int label_width = -1;
 452                 if (label_width < 0) {
 453                         int i, w;
 454                         for (i = 0; i < ARRAY_SIZE(prio_names); i++) {
 455                                 w = strlen(_(prio_names[i]));
 456                                 if (label_width < w)
 457                                         label_width = w;
 458                         }
 459                 }
 460                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 461                         struct possible_tag *t = &all_matches[cur_match];
 462                         fprintf(stderr, " %-*s %8d %s\n",
 463                                 label_width, _(prio_names[t->name->prio]),
 464                                 t->depth, t->name->path);
 465                 }
 466                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 467                 if (gave_up_on) {
 468                         fprintf(stderr,
 469                                 _("more than %i tags found; listed %i most recent\n"
 470                                 "gave up search at %s\n"),
 471                                 max_candidates, max_candidates,
 472                                 oid_to_hex(&gave_up_on->object.oid));
 473                 }
 474         }
 475
 476         append_name(all_matches[0].name, dst);
 477         if (all_matches[0].name->misnamed || abbrev)
 478                 append_suffix(all_matches[0].depth, &cmit->object.oid, dst);
 479         if (suffix)
 480                 strbuf_addstr(dst, suffix);
 481 }
 482
 483 struct process_commit_data {
 484         struct object_id current_commit;
 485         struct object_id looking_for;
 486         struct strbuf *dst;
 487         struct rev_info *revs;
 488 };
 489
 490 static void process_commit(struct commit *commit, void *data)
 491 {
 492         struct process_commit_data *pcd = data;
 493         pcd->current_commit = commit->object.oid;
 494 }
 495
 496 static void process_object(struct object *obj, const char *path, void *data)
 497 {
 498         struct process_commit_data *pcd = data;
 499
 500         if (oideq(&pcd->looking_for, &obj->oid) && !pcd->dst->len) {
 501                 reset_revision_walk();
 502                 describe_commit(&pcd->current_commit, pcd->dst);
 503                 strbuf_addf(pcd->dst, ":%s", path);
 504                 free_commit_list(pcd->revs->commits);
 505                 pcd->revs->commits = NULL;
 506         }
 507 }
 508
 509 static void describe_blob(struct object_id oid, struct strbuf *dst)
 510 {
 511         struct rev_info revs;
 512         struct strvec args = STRVEC_INIT;
 513         struct process_commit_data pcd = { *null_oid(), oid, dst, &revs};
 514
 515         strvec_pushl(&args, "internal: The first arg is not parsed",
 516                      "--objects", "--in-commit-order", "--reverse", "HEAD",
 517                      NULL);
 518
 519         repo_init_revisions(the_repository, &revs, NULL);
 520         if (setup_revisions(args.nr, args.v, &revs, NULL) > 1)
 521                 BUG("setup_revisions could not handle all args?");
 522
 523         if (prepare_revision_walk(&revs))
 524                 die("revision walk setup failed");
 525
 526         traverse_commit_list(&revs, process_commit, process_object, &pcd);
 527         reset_revision_walk();
 528         release_revisions(&revs);
 529 }
 530
 531 static void describe(const char *arg, int last_one)
 532 {
 533         struct object_id oid;
 534         struct commit *cmit;
 535         struct strbuf sb = STRBUF_INIT;
 536
 537         if (debug)
 538                 fprintf(stderr, _("describe %s\n"), arg);
 539
 540         if (repo_get_oid(the_repository, arg, &oid))
 541                 die(_("Not a valid object name %s"), arg);
 542         cmit = lookup_commit_reference_gently(the_repository, &oid, 1);
 543
 544         if (cmit)
 545                 describe_commit(&oid, &sb);
 546         else if (oid_object_info(the_repository, &oid, NULL) == OBJ_BLOB)
 547                 describe_blob(oid, &sb);
 548         else
 549                 die(_("%s is neither a commit nor blob"), arg);
 550
 551         puts(sb.buf);
 552
 553         if (!last_one)
 554                 clear_commit_marks(cmit, -1);
 555
 556         strbuf_release(&sb);
 557 }
 558
 559 int cmd_describe(int argc, const char **argv, const char *prefix)
 560 {
 561         int contains = 0;
 562         struct option options[] = {
 563                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 564                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
 565                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
 566                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
 567                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
 568                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
 569                 OPT__ABBREV(&abbrev),
 570                 OPT_SET_INT(0, "exact-match", &max_candidates,
 571                             N_("only output exact matches"), 0),
 572                 OPT_INTEGER(0, "candidates", &max_candidates,
 573                             N_("consider <n> most recent tags (default: 10)")),
 574                 OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),
 575                            N_("only consider tags matching <pattern>")),
 576                 OPT_STRING_LIST(0, "exclude", &exclude_patterns, N_("pattern"),
 577                            N_("do not consider tags matching <pattern>")),
 578                 OPT_BOOL(0, "always",        &always,
 579                         N_("show abbreviated commit object as fallback")),
 580                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 581                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 582                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 583                 {OPTION_STRING, 0, "broken",  &broken, N_("mark"),
 584                         N_("append <mark> on broken working tree (default: \"-broken\")"),
 585                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-broken"},
 586                 OPT_END(),
 587         };
 588
 589         git_config(git_default_config, NULL);
 590         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 591         if (abbrev < 0)
 592                 abbrev = DEFAULT_ABBREV;
 593
 594         if (max_candidates < 0)
 595                 max_candidates = 0;
 596         else if (max_candidates > MAX_TAGS)
 597                 max_candidates = MAX_TAGS;
 598
 599         save_commit_buffer = 0;
 600
 601         if (longformat && abbrev == 0)
 602                 die(_("options '%s' and '%s' cannot be used together"), "--long", "--abbrev=0");
 603
 604         if (contains) {
 605                 struct string_list_item *item;
 606                 struct strvec args;
 607
 608                 strvec_init(&args);
 609                 strvec_pushl(&args, "name-rev",
 610                              "--peel-tag", "--name-only", "--no-undefined",
 611                              NULL);
 612                 if (always)
 613                         strvec_push(&args, "--always");
 614                 if (!all) {
 615                         strvec_push(&args, "--tags");
 616                         for_each_string_list_item(item, &patterns)
 617                                 strvec_pushf(&args, "--refs=refs/tags/%s", item->string);
 618                         for_each_string_list_item(item, &exclude_patterns)
 619                                 strvec_pushf(&args, "--exclude=refs/tags/%s", item->string);
 620                 }
 621                 if (argc)
 622                         strvec_pushv(&args, argv);
 623                 else
 624                         strvec_push(&args, "HEAD");
 625                 return cmd_name_rev(args.nr, args.v, prefix);
 626         }
 627
 628         hashmap_init(&names, commit_name_neq, NULL, 0);
 629         for_each_rawref(get_name, NULL);
 630         if (!hashmap_get_size(&names) && !always)
 631                 die(_("No names found, cannot describe anything."));
 632
 633         if (argc == 0) {
 634                 if (broken) {
 635                         struct child_process cp = CHILD_PROCESS_INIT;
 636                         strvec_pushv(&cp.args, diff_index_args);
 637                         cp.git_cmd = 1;
 638                         cp.no_stdin = 1;
 639                         cp.no_stdout = 1;
 640
 641                         if (!dirty)
 642                                 dirty = "-dirty";
 643
 644                         switch (run_command(&cp)) {
 645                         case 0:
 646                                 suffix = NULL;
 647                                 break;
 648                         case 1:
 649                                 suffix = dirty;
 650                                 break;
 651                         default:
 652                                 /* diff-index aborted abnormally */
 653                                 suffix = broken;
 654                         }
 655                 } else if (dirty) {
 656                         struct lock_file index_lock = LOCK_INIT;
 657                         struct rev_info revs;
 658                         struct strvec args = STRVEC_INIT;
 659                         int fd, result;
 660
 661                         setup_work_tree();
 662                         prepare_repo_settings(the_repository);
 663                         the_repository->settings.command_requires_full_index = 0;
 664                         repo_read_index(the_repository);
 665                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 666                                       NULL, NULL, NULL);
 667                         fd = repo_hold_locked_index(the_repository,
 668                                                     &index_lock, 0);
 669                         if (0 <= fd)
 670                                 repo_update_index_if_able(the_repository, &index_lock);
 671
 672                         repo_init_revisions(the_repository, &revs, prefix);
 673                         strvec_pushv(&args, diff_index_args);
 674                         if (setup_revisions(args.nr, args.v, &revs, NULL) != 1)
 675                                 BUG("malformed internal diff-index command line");
 676                         result = run_diff_index(&revs, 0);
 677
 678                         if (!diff_result_code(&revs.diffopt, result))
 679                                 suffix = NULL;
 680                         else
 681                                 suffix = dirty;
 682                         release_revisions(&revs);
 683                 }
 684                 describe("HEAD", 1);
 685         } else if (dirty) {
 686                 die(_("option '%s' and commit-ishes cannot be used together"), "--dirty");
 687         } else if (broken) {
 688                 die(_("option '%s' and commit-ishes cannot be used together"), "--broken");
 689         } else {
 690                 while (argc-- > 0)
 691                         describe(*argv++, argc == 0);
 692         }
 693         return 0;
 694 }