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