builtin/describe.c

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