builtin/describe.c

   1 #include "builtin.h"
   2 #include "config.h"
   3 #include "environment.h"
   4 #include "gettext.h"
   5 #include "hex.h"
   6 #include "lockfile.h"
   7 #include "commit.h"
   8 #include "tag.h"
   9 #include "refs.h"
  10 #include "object-name.h"
  11 #include "parse-options.h"
  12 #include "read-cache-ll.h"
  13 #include "revision.h"
  14 #include "diff.h"
  15 #include "hashmap.h"
  16 #include "setup.h"
  17 #include "strvec.h"
  18 #include "run-command.h"
  19 #include "object-store-ll.h"
  20 #include "list-objects.h"
  21 #include "commit-slab.h"
  22 #include "wildmatch.h"
  23
  24 #define MAX_TAGS        (FLAG_BITS - 1)
  25 #define DEFAULT_CANDIDATES 10
  26
  27 define_commit_slab(commit_names, struct commit_name *);
  28
  29 static const char * const describe_usage[] = {
  30         N_("git describe [--all] [--tags] [--contains] [--abbrev=<n>] [<commit-ish>...]"),
  31         N_("git describe [--all] [--tags] [--contains] [--abbrev=<n>] --dirty[=<mark>]"),
  32         N_("git describe <blob>"),
  33         NULL
  34 };
  35
  36 static int debug;       /* Display lots of verbose info */
  37 static int all; /* Any valid ref can be used */
  38 static int tags;        /* Allow lightweight tags */
  39 static int longformat;
  40 static int first_parent;
  41 static int abbrev = -1; /* unspecified */
  42 static int max_candidates = DEFAULT_CANDIDATES;
  43 static struct hashmap names;
  44 static int have_util;
  45 static struct string_list patterns = STRING_LIST_INIT_NODUP;
  46 static struct string_list exclude_patterns = STRING_LIST_INIT_NODUP;
  47 static int always;
  48 static const char *suffix, *dirty, *broken;
  49 static struct commit_names commit_names;
  50
  51 /* diff-index command arguments to check if working tree is dirty. */
  52 static const char *diff_index_args[] = {
  53         "diff-index", "--quiet", "HEAD", "--", NULL
  54 };
  55
  56 static const char *update_index_args[] = {
  57         "update-index", "--unmerged", "-q", "--refresh", NULL
  58 };
  59
  60 struct commit_name {
  61         struct hashmap_entry entry;
  62         struct object_id peeled;
  63         struct tag *tag;
  64         unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  65         unsigned name_checked:1;
  66         unsigned misnamed:1;
  67         struct object_id oid;
  68         char *path;
  69 };
  70
  71 static const char *prio_names[] = {
  72         N_("head"), N_("lightweight"), N_("annotated"),
  73 };
  74
  75 static int commit_name_neq(const void *cmp_data UNUSED,
  76                            const struct hashmap_entry *eptr,
  77                            const struct hashmap_entry *entry_or_key,
  78                            const void *peeled)
  79 {
  80         const struct commit_name *cn1, *cn2;
  81
  82         cn1 = container_of(eptr, const struct commit_name, entry);
  83         cn2 = container_of(entry_or_key, const struct commit_name, entry);
  84
  85         return !oideq(&cn1->peeled, peeled ? peeled : &cn2->peeled);
  86 }
  87
  88 static inline struct commit_name *find_commit_name(const struct object_id *peeled)
  89 {
  90         return hashmap_get_entry_from_hash(&names, oidhash(peeled), peeled,
  91                                                 struct commit_name, entry);
  92 }
  93
  94 static int replace_name(struct commit_name *e,
  95                                int prio,
  96                                const struct object_id *oid,
  97                                struct tag **tag)
  98 {
  99         if (!e || e->prio < prio)
 100                 return 1;
 101
 102         if (e->prio == 2 && prio == 2) {
 103                 /* Multiple annotated tags point to the same commit.
 104                  * Select one to keep based upon their tagger date.
 105                  */
 106                 struct tag *t;
 107
 108                 if (!e->tag) {
 109                         t = lookup_tag(the_repository, &e->oid);
 110                         if (!t || parse_tag(t))
 111                                 return 1;
 112                         e->tag = t;
 113                 }
 114
 115                 t = lookup_tag(the_repository, oid);
 116                 if (!t || parse_tag(t))
 117                         return 0;
 118                 *tag = t;
 119
 120                 if (e->tag->date < t->date)
 121                         return 1;
 122         }
 123
 124         return 0;
 125 }
 126
 127 static void add_to_known_names(const char *path,
 128                                const struct object_id *peeled,
 129                                int prio,
 130                                const struct object_id *oid)
 131 {
 132         struct commit_name *e = find_commit_name(peeled);
 133         struct tag *tag = NULL;
 134         if (replace_name(e, prio, oid, &tag)) {
 135                 if (!e) {
 136                         e = xmalloc(sizeof(struct commit_name));
 137                         oidcpy(&e->peeled, peeled);
 138                         hashmap_entry_init(&e->entry, oidhash(peeled));
 139                         hashmap_add(&names, &e->entry);
 140                         e->path = NULL;
 141                 }
 142                 e->tag = tag;
 143                 e->prio = prio;
 144                 e->name_checked = 0;
 145                 e->misnamed = 0;
 146                 oidcpy(&e->oid, oid);
 147                 free(e->path);
 148                 e->path = xstrdup(path);
 149         }
 150 }
 151
 152 static int get_name(const char *path, const struct object_id *oid,
 153                     int flag UNUSED, void *cb_data UNUSED)
 154 {
 155         int is_tag = 0;
 156         struct object_id peeled;
 157         int is_annotated, prio;
 158         const char *path_to_match = NULL;
 159
 160         if (skip_prefix(path, "refs/tags/", &path_to_match)) {
 161                 is_tag = 1;
 162         } else if (all) {
 163                 if ((exclude_patterns.nr || patterns.nr) &&
 164                     !skip_prefix(path, "refs/heads/", &path_to_match) &&
 165                     !skip_prefix(path, "refs/remotes/", &path_to_match)) {
 166                         /* Only accept reference of known type if there are match/exclude patterns */
 167                         return 0;
 168                 }
 169         } else {
 170                 /* Reject anything outside refs/tags/ unless --all */
 171                 return 0;
 172         }
 173
 174         /*
 175          * If we're given exclude patterns, first exclude any tag which match
 176          * any of the exclude pattern.
 177          */
 178         if (exclude_patterns.nr) {
 179                 struct string_list_item *item;
 180
 181                 for_each_string_list_item(item, &exclude_patterns) {
 182                         if (!wildmatch(item->string, path_to_match, 0))
 183                                 return 0;
 184                 }
 185         }
 186
 187         /*
 188          * If we're given patterns, accept only tags which match at least one
 189          * pattern.
 190          */
 191         if (patterns.nr) {
 192                 int found = 0;
 193                 struct string_list_item *item;
 194
 195                 for_each_string_list_item(item, &patterns) {
 196                         if (!wildmatch(item->string, path_to_match, 0)) {
 197                                 found = 1;
 198                                 break;
 199                         }
 200                 }
 201
 202                 if (!found)
 203                         return 0;
 204         }
 205
 206         /* Is it annotated? */
 207         if (!peel_iterated_oid(the_repository, oid, &peeled)) {
 208                 is_annotated = !oideq(oid, &peeled);
 209         } else {
 210                 oidcpy(&peeled, oid);
 211                 is_annotated = 0;
 212         }
 213
 214         /*
 215          * By default, we only use annotated tags, but with --tags
 216          * we fall back to lightweight ones (even without --tags,
 217          * we still remember lightweight ones, only to give hints
 218          * in an error message).  --all allows any refs to be used.
 219          */
 220         if (is_annotated)
 221                 prio = 2;
 222         else if (is_tag)
 223                 prio = 1;
 224         else
 225                 prio = 0;
 226
 227         add_to_known_names(all ? path + 5 : path + 10, &peeled, prio, oid);
 228         return 0;
 229 }
 230
 231 struct possible_tag {
 232         struct commit_name *name;
 233         int depth;
 234         int found_order;
 235         unsigned flag_within;
 236 };
 237
 238 static int compare_pt(const void *a_, const void *b_)
 239 {
 240         struct possible_tag *a = (struct possible_tag *)a_;
 241         struct possible_tag *b = (struct possible_tag *)b_;
 242         if (a->depth != b->depth)
 243                 return a->depth - b->depth;
 244         if (a->found_order != b->found_order)
 245                 return a->found_order - b->found_order;
 246         return 0;
 247 }
 248
 249 static unsigned long finish_depth_computation(
 250         struct commit_list **list,
 251         struct possible_tag *best)
 252 {
 253         unsigned long seen_commits = 0;
 254         while (*list) {
 255                 struct commit *c = pop_commit(list);
 256                 struct commit_list *parents = c->parents;
 257                 seen_commits++;
 258                 if (c->object.flags & best->flag_within) {
 259                         struct commit_list *a = *list;
 260                         while (a) {
 261                                 struct commit *i = a->item;
 262                                 if (!(i->object.flags & best->flag_within))
 263                                         break;
 264                                 a = a->next;
 265                         }
 266                         if (!a)
 267                                 break;
 268                 } else
 269                         best->depth++;
 270                 while (parents) {
 271                         struct commit *p = parents->item;
 272                         repo_parse_commit(the_repository, p);
 273                         if (!(p->object.flags & SEEN))
 274                                 commit_list_insert_by_date(p, list);
 275                         p->object.flags |= c->object.flags;
 276                         parents = parents->next;
 277                 }
 278         }
 279         return seen_commits;
 280 }
 281
 282 static void append_name(struct commit_name *n, struct strbuf *dst)
 283 {
 284         if (n->prio == 2 && !n->tag) {
 285                 n->tag = lookup_tag(the_repository, &n->oid);
 286                 if (!n->tag || parse_tag(n->tag))
 287                         die(_("annotated tag %s not available"), n->path);
 288         }
 289         if (n->tag && !n->name_checked) {
 290                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path)) {
 291                         warning(_("tag '%s' is externally known as '%s'"),
 292                                 n->path, n->tag->tag);
 293                         n->misnamed = 1;
 294                 }
 295                 n->name_checked = 1;
 296         }
 297
 298         if (n->tag) {
 299                 if (all)
 300                         strbuf_addstr(dst, "tags/");
 301                 strbuf_addstr(dst, n->tag->tag);
 302         } else {
 303                 strbuf_addstr(dst, n->path);
 304         }
 305 }
 306
 307 static void append_suffix(int depth, const struct object_id *oid, struct strbuf *dst)
 308 {
 309         strbuf_addf(dst, "-%d-g%s", depth,
 310                     repo_find_unique_abbrev(the_repository, oid, abbrev));
 311 }
 312
 313 static void describe_commit(struct object_id *oid, struct strbuf *dst)
 314 {
 315         struct commit *cmit, *gave_up_on = NULL;
 316         struct commit_list *list;
 317         struct commit_name *n;
 318         struct possible_tag all_matches[MAX_TAGS];
 319         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 320         unsigned long seen_commits = 0;
 321         unsigned int unannotated_cnt = 0;
 322
 323         cmit = lookup_commit_reference(the_repository, oid);
 324
 325         n = find_commit_name(&cmit->object.oid);
 326         if (n && (tags || all || n->prio == 2)) {
 327                 /*
 328                  * Exact match to an existing ref.
 329                  */
 330                 append_name(n, dst);
 331                 if (n->misnamed || longformat)
 332                         append_suffix(0, n->tag ? get_tagged_oid(n->tag) : oid, dst);
 333                 if (suffix)
 334                         strbuf_addstr(dst, suffix);
 335                 return;
 336         }
 337
 338         if (!max_candidates)
 339                 die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));
 340         if (debug)
 341                 fprintf(stderr, _("No exact match on refs or tags, searching to describe\n"));
 342
 343         if (!have_util) {
 344                 struct hashmap_iter iter;
 345                 struct commit *c;
 346                 struct commit_name *n;
 347
 348                 init_commit_names(&commit_names);
 349                 hashmap_for_each_entry(&names, &iter, n,
 350                                         entry /* member name */) {
 351                         c = lookup_commit_reference_gently(the_repository,
 352                                                            &n->peeled, 1);
 353                         if (c)
 354                                 *commit_names_at(&commit_names, c) = n;
 355                 }
 356                 have_util = 1;
 357         }
 358
 359         list = NULL;
 360         cmit->object.flags = SEEN;
 361         commit_list_insert(cmit, &list);
 362         while (list) {
 363                 struct commit *c = pop_commit(&list);
 364                 struct commit_list *parents = c->parents;
 365                 struct commit_name **slot;
 366
 367                 seen_commits++;
 368                 slot = commit_names_peek(&commit_names, c);
 369                 n = slot ? *slot : NULL;
 370                 if (n) {
 371                         if (!tags && !all && n->prio < 2) {
 372                                 unannotated_cnt++;
 373                         } else if (match_cnt < max_candidates) {
 374                                 struct possible_tag *t = &all_matches[match_cnt++];
 375                                 t->name = n;
 376                                 t->depth = seen_commits - 1;
 377                                 t->flag_within = 1u << match_cnt;
 378                                 t->found_order = match_cnt;
 379                                 c->object.flags |= t->flag_within;
 380                                 if (n->prio == 2)
 381                                         annotated_cnt++;
 382                         }
 383                         else {
 384                                 gave_up_on = c;
 385                                 break;
 386                         }
 387                 }
 388                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 389                         struct possible_tag *t = &all_matches[cur_match];
 390                         if (!(c->object.flags & t->flag_within))
 391                                 t->depth++;
 392                 }
 393                 /* Stop if last remaining path already covered by best candidate(s) */
 394                 if (annotated_cnt && !list) {
 395                         int best_depth = INT_MAX;
 396                         unsigned best_within = 0;
 397                         for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 398                                 struct possible_tag *t = &all_matches[cur_match];
 399                                 if (t->depth < best_depth) {
 400                                         best_depth = t->depth;
 401                                         best_within = t->flag_within;
 402                                 } else if (t->depth == best_depth) {
 403                                         best_within |= t->flag_within;
 404                                 }
 405                         }
 406                         if ((c->object.flags & best_within) == best_within) {
 407                                 if (debug)
 408                                         fprintf(stderr, _("finished search at %s\n"),
 409                                                 oid_to_hex(&c->object.oid));
 410                                 break;
 411                         }
 412                 }
 413                 while (parents) {
 414                         struct commit *p = parents->item;
 415                         repo_parse_commit(the_repository, p);
 416                         if (!(p->object.flags & SEEN))
 417                                 commit_list_insert_by_date(p, &list);
 418                         p->object.flags |= c->object.flags;
 419                         parents = parents->next;
 420
 421                         if (first_parent)
 422                                 break;
 423                 }
 424         }
 425
 426         if (!match_cnt) {
 427                 struct object_id *cmit_oid = &cmit->object.oid;
 428                 if (always) {
 429                         strbuf_add_unique_abbrev(dst, cmit_oid, abbrev);
 430                         if (suffix)
 431                                 strbuf_addstr(dst, suffix);
 432                         return;
 433                 }
 434                 if (unannotated_cnt)
 435                         die(_("No annotated tags can describe '%s'.\n"
 436                             "However, there were unannotated tags: try --tags."),
 437                             oid_to_hex(cmit_oid));
 438                 else
 439                         die(_("No tags can describe '%s'.\n"
 440                             "Try --always, or create some tags."),
 441                             oid_to_hex(cmit_oid));
 442         }
 443
 444         QSORT(all_matches, match_cnt, compare_pt);
 445
 446         if (gave_up_on) {
 447                 commit_list_insert_by_date(gave_up_on, &list);
 448                 seen_commits--;
 449         }
 450         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 451         free_commit_list(list);
 452
 453         if (debug) {
 454                 static int label_width = -1;
 455                 if (label_width < 0) {
 456                         int i, w;
 457                         for (i = 0; i < ARRAY_SIZE(prio_names); i++) {
 458                                 w = strlen(_(prio_names[i]));
 459                                 if (label_width < w)
 460                                         label_width = w;
 461                         }
 462                 }
 463                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 464                         struct possible_tag *t = &all_matches[cur_match];
 465                         fprintf(stderr, " %-*s %8d %s\n",
 466                                 label_width, _(prio_names[t->name->prio]),
 467                                 t->depth, t->name->path);
 468                 }
 469                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 470                 if (gave_up_on) {
 471                         fprintf(stderr,
 472                                 _("more than %i tags found; listed %i most recent\n"
 473                                 "gave up search at %s\n"),
 474                                 max_candidates, max_candidates,
 475                                 oid_to_hex(&gave_up_on->object.oid));
 476                 }
 477         }
 478
 479         append_name(all_matches[0].name, dst);
 480         if (all_matches[0].name->misnamed || abbrev)
 481                 append_suffix(all_matches[0].depth, &cmit->object.oid, dst);
 482         if (suffix)
 483                 strbuf_addstr(dst, suffix);
 484 }
 485
 486 struct process_commit_data {
 487         struct object_id current_commit;
 488         struct object_id looking_for;
 489         struct strbuf *dst;
 490         struct rev_info *revs;
 491 };
 492
 493 static void process_commit(struct commit *commit, void *data)
 494 {
 495         struct process_commit_data *pcd = data;
 496         pcd->current_commit = commit->object.oid;
 497 }
 498
 499 static void process_object(struct object *obj, const char *path, void *data)
 500 {
 501         struct process_commit_data *pcd = data;
 502
 503         if (oideq(&pcd->looking_for, &obj->oid) && !pcd->dst->len) {
 504                 reset_revision_walk();
 505                 describe_commit(&pcd->current_commit, pcd->dst);
 506                 strbuf_addf(pcd->dst, ":%s", path);
 507                 free_commit_list(pcd->revs->commits);
 508                 pcd->revs->commits = NULL;
 509         }
 510 }
 511
 512 static void describe_blob(struct object_id oid, struct strbuf *dst)
 513 {
 514         struct rev_info revs;
 515         struct strvec args = STRVEC_INIT;
 516         struct process_commit_data pcd = { *null_oid(), oid, dst, &revs};
 517
 518         strvec_pushl(&args, "internal: The first arg is not parsed",
 519                      "--objects", "--in-commit-order", "--reverse", "HEAD",
 520                      NULL);
 521
 522         repo_init_revisions(the_repository, &revs, NULL);
 523         if (setup_revisions(args.nr, args.v, &revs, NULL) > 1)
 524                 BUG("setup_revisions could not handle all args?");
 525
 526         if (prepare_revision_walk(&revs))
 527                 die("revision walk setup failed");
 528
 529         traverse_commit_list(&revs, process_commit, process_object, &pcd);
 530         reset_revision_walk();
 531         release_revisions(&revs);
 532 }
 533
 534 static void describe(const char *arg, int last_one)
 535 {
 536         struct object_id oid;
 537         struct commit *cmit;
 538         struct strbuf sb = STRBUF_INIT;
 539
 540         if (debug)
 541                 fprintf(stderr, _("describe %s\n"), arg);
 542
 543         if (repo_get_oid(the_repository, arg, &oid))
 544                 die(_("Not a valid object name %s"), arg);
 545         cmit = lookup_commit_reference_gently(the_repository, &oid, 1);
 546
 547         if (cmit)
 548                 describe_commit(&oid, &sb);
 549         else if (oid_object_info(the_repository, &oid, NULL) == OBJ_BLOB)
 550                 describe_blob(oid, &sb);
 551         else
 552                 die(_("%s is neither a commit nor blob"), arg);
 553
 554         puts(sb.buf);
 555
 556         if (!last_one)
 557                 clear_commit_marks(cmit, -1);
 558
 559         strbuf_release(&sb);
 560 }
 561
 562 static int option_parse_exact_match(const struct option *opt, const char *arg,
 563                                     int unset)
 564 {
 565         int *val = opt->value;
 566
 567         BUG_ON_OPT_ARG(arg);
 568
 569         *val = unset ? DEFAULT_CANDIDATES : 0;
 570         return 0;
 571 }
 572
 573 int cmd_describe(int argc, const char **argv, const char *prefix)
 574 {
 575         int contains = 0;
 576         struct option options[] = {
 577                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 578                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
 579                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
 580                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
 581                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
 582                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
 583                 OPT__ABBREV(&abbrev),
 584                 OPT_CALLBACK_F(0, "exact-match", &max_candidates, NULL,
 585                                N_("only output exact matches"),
 586                                PARSE_OPT_NOARG, option_parse_exact_match),
 587                 OPT_INTEGER(0, "candidates", &max_candidates,
 588                             N_("consider <n> most recent tags (default: 10)")),
 589                 OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),
 590                            N_("only consider tags matching <pattern>")),
 591                 OPT_STRING_LIST(0, "exclude", &exclude_patterns, N_("pattern"),
 592                            N_("do not consider tags matching <pattern>")),
 593                 OPT_BOOL(0, "always",        &always,
 594                         N_("show abbreviated commit object as fallback")),
 595                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 596                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 597                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 598                 {OPTION_STRING, 0, "broken",  &broken, N_("mark"),
 599                         N_("append <mark> on broken working tree (default: \"-broken\")"),
 600                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-broken"},
 601                 OPT_END(),
 602         };
 603
 604         git_config(git_default_config, NULL);
 605         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 606         if (abbrev < 0)
 607                 abbrev = DEFAULT_ABBREV;
 608
 609         if (max_candidates < 0)
 610                 max_candidates = 0;
 611         else if (max_candidates > MAX_TAGS)
 612                 max_candidates = MAX_TAGS;
 613
 614         save_commit_buffer = 0;
 615
 616         if (longformat && abbrev == 0)
 617                 die(_("options '%s' and '%s' cannot be used together"), "--long", "--abbrev=0");
 618
 619         if (contains) {
 620                 struct string_list_item *item;
 621                 struct strvec args;
 622
 623                 strvec_init(&args);
 624                 strvec_pushl(&args, "name-rev",
 625                              "--peel-tag", "--name-only", "--no-undefined",
 626                              NULL);
 627                 if (always)
 628                         strvec_push(&args, "--always");
 629                 if (!all) {
 630                         strvec_push(&args, "--tags");
 631                         for_each_string_list_item(item, &patterns)
 632                                 strvec_pushf(&args, "--refs=refs/tags/%s", item->string);
 633                         for_each_string_list_item(item, &exclude_patterns)
 634                                 strvec_pushf(&args, "--exclude=refs/tags/%s", item->string);
 635                 }
 636                 if (argc)
 637                         strvec_pushv(&args, argv);
 638                 else
 639                         strvec_push(&args, "HEAD");
 640                 return cmd_name_rev(args.nr, args.v, prefix);
 641         }
 642
 643         hashmap_init(&names, commit_name_neq, NULL, 0);
 644         refs_for_each_rawref(get_main_ref_store(the_repository), get_name,
 645                              NULL);
 646         if (!hashmap_get_size(&names) && !always)
 647                 die(_("No names found, cannot describe anything."));
 648
 649         if (argc == 0) {
 650                 if (broken) {
 651                         struct child_process cp = CHILD_PROCESS_INIT;
 652
 653                         strvec_pushv(&cp.args, update_index_args);
 654                         cp.git_cmd = 1;
 655                         cp.no_stdin = 1;
 656                         cp.no_stdout = 1;
 657                         run_command(&cp);
 658
 659                         child_process_init(&cp);
 660                         strvec_pushv(&cp.args, diff_index_args);
 661                         cp.git_cmd = 1;
 662                         cp.no_stdin = 1;
 663                         cp.no_stdout = 1;
 664
 665                         if (!dirty)
 666                                 dirty = "-dirty";
 667
 668                         switch (run_command(&cp)) {
 669                         case 0:
 670                                 suffix = NULL;
 671                                 break;
 672                         case 1:
 673                                 suffix = dirty;
 674                                 break;
 675                         default:
 676                                 /* diff-index aborted abnormally */
 677                                 suffix = broken;
 678                         }
 679                 } else if (dirty) {
 680                         struct lock_file index_lock = LOCK_INIT;
 681                         struct rev_info revs;
 682                         struct strvec args = STRVEC_INIT;
 683                         int fd;
 684
 685                         setup_work_tree();
 686                         prepare_repo_settings(the_repository);
 687                         the_repository->settings.command_requires_full_index = 0;
 688                         repo_read_index(the_repository);
 689                         refresh_index(the_repository->index, REFRESH_QUIET|REFRESH_UNMERGED,
 690                                       NULL, NULL, NULL);
 691                         fd = repo_hold_locked_index(the_repository,
 692                                                     &index_lock, 0);
 693                         if (0 <= fd)
 694                                 repo_update_index_if_able(the_repository, &index_lock);
 695
 696                         repo_init_revisions(the_repository, &revs, prefix);
 697                         strvec_pushv(&args, diff_index_args);
 698                         if (setup_revisions(args.nr, args.v, &revs, NULL) != 1)
 699                                 BUG("malformed internal diff-index command line");
 700                         run_diff_index(&revs, 0);
 701
 702                         if (!diff_result_code(&revs.diffopt))
 703                                 suffix = NULL;
 704                         else
 705                                 suffix = dirty;
 706                         release_revisions(&revs);
 707                 }
 708                 describe("HEAD", 1);
 709         } else if (dirty) {
 710                 die(_("option '%s' and commit-ishes cannot be used together"), "--dirty");
 711         } else if (broken) {
 712                 die(_("option '%s' and commit-ishes cannot be used together"), "--broken");
 713         } else {
 714                 while (argc-- > 0)
 715                         describe(*argv++, argc == 0);
 716         }
 717         return 0;
 718 }