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