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 "revision.h"
  17 #include "list-objects.h"
  18
  19 #define MAX_TAGS        (FLAG_BITS - 1)
  20
  21 static const char * const describe_usage[] = {
  22         N_("git describe [<options>] [<commit-ish>...]"),
  23         N_("git describe [<options>] --dirty"),
  24         NULL
  25 };
  26
  27 static int debug;       /* Display lots of verbose info */
  28 static int all; /* Any valid ref can be used */
  29 static int tags;        /* Allow lightweight tags */
  30 static int longformat;
  31 static int first_parent;
  32 static int abbrev = -1; /* unspecified */
  33 static int max_candidates = 10;
  34 static struct hashmap names;
  35 static int have_util;
  36 static struct string_list patterns = STRING_LIST_INIT_NODUP;
  37 static struct string_list exclude_patterns = STRING_LIST_INIT_NODUP;
  38 static int always;
  39 static const char *suffix, *dirty, *broken;
  40
  41 /* diff-index command arguments to check if working tree is dirty. */
  42 static const char *diff_index_args[] = {
  43         "diff-index", "--quiet", "HEAD", "--", NULL
  44 };
  45
  46 struct commit_name {
  47         struct hashmap_entry entry;
  48         struct object_id peeled;
  49         struct tag *tag;
  50         unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  51         unsigned name_checked:1;
  52         struct object_id oid;
  53         char *path;
  54 };
  55
  56 static const char *prio_names[] = {
  57         N_("head"), N_("lightweight"), N_("annotated"),
  58 };
  59
  60 static int commit_name_cmp(const void *unused_cmp_data,
  61                            const void *entry,
  62                            const void *entry_or_key,
  63                            const void *peeled)
  64 {
  65         const struct commit_name *cn1 = entry;
  66         const struct commit_name *cn2 = entry_or_key;
  67
  68         return oidcmp(&cn1->peeled, peeled ? peeled : &cn2->peeled);
  69 }
  70
  71 static inline struct commit_name *find_commit_name(const struct object_id *peeled)
  72 {
  73         return hashmap_get_from_hash(&names, sha1hash(peeled->hash), peeled->hash);
  74 }
  75
  76 static int replace_name(struct commit_name *e,
  77                                int prio,
  78                                const struct object_id *oid,
  79                                struct tag **tag)
  80 {
  81         if (!e || e->prio < prio)
  82                 return 1;
  83
  84         if (e->prio == 2 && prio == 2) {
  85                 /* Multiple annotated tags point to the same commit.
  86                  * Select one to keep based upon their tagger date.
  87                  */
  88                 struct tag *t;
  89
  90                 if (!e->tag) {
  91                         t = lookup_tag(&e->oid);
  92                         if (!t || parse_tag(t))
  93                                 return 1;
  94                         e->tag = t;
  95                 }
  96
  97                 t = lookup_tag(oid);
  98                 if (!t || parse_tag(t))
  99                         return 0;
 100                 *tag = t;
 101
 102                 if (e->tag->date < t->date)
 103                         return 1;
 104         }
 105
 106         return 0;
 107 }
 108
 109 static void add_to_known_names(const char *path,
 110                                const struct object_id *peeled,
 111                                int prio,
 112                                const struct object_id *oid)
 113 {
 114         struct commit_name *e = find_commit_name(peeled);
 115         struct tag *tag = NULL;
 116         if (replace_name(e, prio, oid, &tag)) {
 117                 if (!e) {
 118                         e = xmalloc(sizeof(struct commit_name));
 119                         oidcpy(&e->peeled, peeled);
 120                         hashmap_entry_init(e, sha1hash(peeled->hash));
 121                         hashmap_add(&names, e);
 122                         e->path = NULL;
 123                 }
 124                 e->tag = tag;
 125                 e->prio = prio;
 126                 e->name_checked = 0;
 127                 oidcpy(&e->oid, oid);
 128                 free(e->path);
 129                 e->path = xstrdup(path);
 130         }
 131 }
 132
 133 static int get_name(const char *path, const struct object_id *oid, int flag, void *cb_data)
 134 {
 135         int is_tag = 0;
 136         struct object_id peeled;
 137         int is_annotated, prio;
 138         const char *path_to_match = NULL;
 139
 140         if (skip_prefix(path, "refs/tags/", &path_to_match)) {
 141                 is_tag = 1;
 142         } else if (all) {
 143                 if ((exclude_patterns.nr || patterns.nr) &&
 144                     !skip_prefix(path, "refs/heads/", &path_to_match) &&
 145                     !skip_prefix(path, "refs/remotes/", &path_to_match)) {
 146                         /* Only accept reference of known type if there are match/exclude patterns */
 147                         return 0;
 148                 }
 149         } else {
 150                 /* Reject anything outside refs/tags/ unless --all */
 151                 return 0;
 152         }
 153
 154         /*
 155          * If we're given exclude patterns, first exclude any tag which match
 156          * any of the exclude pattern.
 157          */
 158         if (exclude_patterns.nr) {
 159                 struct string_list_item *item;
 160
 161                 for_each_string_list_item(item, &exclude_patterns) {
 162                         if (!wildmatch(item->string, path_to_match, 0))
 163                                 return 0;
 164                 }
 165         }
 166
 167         /*
 168          * If we're given patterns, accept only tags which match at least one
 169          * pattern.
 170          */
 171         if (patterns.nr) {
 172                 int found = 0;
 173                 struct string_list_item *item;
 174
 175                 for_each_string_list_item(item, &patterns) {
 176                         if (!wildmatch(item->string, path_to_match, 0)) {
 177                                 found = 1;
 178                                 break;
 179                         }
 180                 }
 181
 182                 if (!found)
 183                         return 0;
 184         }
 185
 186         /* Is it annotated? */
 187         if (!peel_ref(path, &peeled)) {
 188                 is_annotated = !!oidcmp(oid, &peeled);
 189         } else {
 190                 oidcpy(&peeled, oid);
 191                 is_annotated = 0;
 192         }
 193
 194         /*
 195          * By default, we only use annotated tags, but with --tags
 196          * we fall back to lightweight ones (even without --tags,
 197          * we still remember lightweight ones, only to give hints
 198          * in an error message).  --all allows any refs to be used.
 199          */
 200         if (is_annotated)
 201                 prio = 2;
 202         else if (is_tag)
 203                 prio = 1;
 204         else
 205                 prio = 0;
 206
 207         add_to_known_names(all ? path + 5 : path + 10, &peeled, prio, oid);
 208         return 0;
 209 }
 210
 211 struct possible_tag {
 212         struct commit_name *name;
 213         int depth;
 214         int found_order;
 215         unsigned flag_within;
 216 };
 217
 218 static int compare_pt(const void *a_, const void *b_)
 219 {
 220         struct possible_tag *a = (struct possible_tag *)a_;
 221         struct possible_tag *b = (struct possible_tag *)b_;
 222         if (a->depth != b->depth)
 223                 return a->depth - b->depth;
 224         if (a->found_order != b->found_order)
 225                 return a->found_order - b->found_order;
 226         return 0;
 227 }
 228
 229 static unsigned long finish_depth_computation(
 230         struct commit_list **list,
 231         struct possible_tag *best)
 232 {
 233         unsigned long seen_commits = 0;
 234         while (*list) {
 235                 struct commit *c = pop_commit(list);
 236                 struct commit_list *parents = c->parents;
 237                 seen_commits++;
 238                 if (c->object.flags & best->flag_within) {
 239                         struct commit_list *a = *list;
 240                         while (a) {
 241                                 struct commit *i = a->item;
 242                                 if (!(i->object.flags & best->flag_within))
 243                                         break;
 244                                 a = a->next;
 245                         }
 246                         if (!a)
 247                                 break;
 248                 } else
 249                         best->depth++;
 250                 while (parents) {
 251                         struct commit *p = parents->item;
 252                         parse_commit(p);
 253                         if (!(p->object.flags & SEEN))
 254                                 commit_list_insert_by_date(p, list);
 255                         p->object.flags |= c->object.flags;
 256                         parents = parents->next;
 257                 }
 258         }
 259         return seen_commits;
 260 }
 261
 262 static void append_name(struct commit_name *n, struct strbuf *dst)
 263 {
 264         if (n->prio == 2 && !n->tag) {
 265                 n->tag = lookup_tag(&n->oid);
 266                 if (!n->tag || parse_tag(n->tag))
 267                         die(_("annotated tag %s not available"), n->path);
 268         }
 269         if (n->tag && !n->name_checked) {
 270                 if (!n->tag->tag)
 271                         die(_("annotated tag %s has no embedded name"), n->path);
 272                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 273                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 274                 n->name_checked = 1;
 275         }
 276
 277         if (n->tag) {
 278                 if (all)
 279                         strbuf_addstr(dst, "tags/");
 280                 strbuf_addstr(dst, n->tag->tag);
 281         } else {
 282                 strbuf_addstr(dst, n->path);
 283         }
 284 }
 285
 286 static void append_suffix(int depth, const struct object_id *oid, struct strbuf *dst)
 287 {
 288         strbuf_addf(dst, "-%d-g%s", depth, find_unique_abbrev(oid->hash, abbrev));
 289 }
 290
 291 static void describe_commit(struct object_id *oid, struct strbuf *dst)
 292 {
 293         struct commit *cmit, *gave_up_on = NULL;
 294         struct commit_list *list;
 295         struct commit_name *n;
 296         struct possible_tag all_matches[MAX_TAGS];
 297         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 298         unsigned long seen_commits = 0;
 299         unsigned int unannotated_cnt = 0;
 300
 301         cmit = lookup_commit_reference(oid);
 302
 303         n = find_commit_name(&cmit->object.oid);
 304         if (n && (tags || all || n->prio == 2)) {
 305                 /*
 306                  * Exact match to an existing ref.
 307                  */
 308                 append_name(n, dst);
 309                 if (longformat)
 310                         append_suffix(0, n->tag ? &n->tag->tagged->oid : oid, dst);
 311                 if (suffix)
 312                         strbuf_addstr(dst, suffix);
 313                 return;
 314         }
 315
 316         if (!max_candidates)
 317                 die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));
 318         if (debug)
 319                 fprintf(stderr, _("No exact match on refs or tags, searching to describe\n"));
 320
 321         if (!have_util) {
 322                 struct hashmap_iter iter;
 323                 struct commit *c;
 324                 struct commit_name *n = hashmap_iter_first(&names, &iter);
 325                 for (; n; n = hashmap_iter_next(&iter)) {
 326                         c = lookup_commit_reference_gently(&n->peeled, 1);
 327                         if (c)
 328                                 c->util = n;
 329                 }
 330                 have_util = 1;
 331         }
 332
 333         list = NULL;
 334         cmit->object.flags = SEEN;
 335         commit_list_insert(cmit, &list);
 336         while (list) {
 337                 struct commit *c = pop_commit(&list);
 338                 struct commit_list *parents = c->parents;
 339                 seen_commits++;
 340                 n = c->util;
 341                 if (n) {
 342                         if (!tags && !all && n->prio < 2) {
 343                                 unannotated_cnt++;
 344                         } else if (match_cnt < max_candidates) {
 345                                 struct possible_tag *t = &all_matches[match_cnt++];
 346                                 t->name = n;
 347                                 t->depth = seen_commits - 1;
 348                                 t->flag_within = 1u << match_cnt;
 349                                 t->found_order = match_cnt;
 350                                 c->object.flags |= t->flag_within;
 351                                 if (n->prio == 2)
 352                                         annotated_cnt++;
 353                         }
 354                         else {
 355                                 gave_up_on = c;
 356                                 break;
 357                         }
 358                 }
 359                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 360                         struct possible_tag *t = &all_matches[cur_match];
 361                         if (!(c->object.flags & t->flag_within))
 362                                 t->depth++;
 363                 }
 364                 if (annotated_cnt && !list) {
 365                         if (debug)
 366                                 fprintf(stderr, _("finished search at %s\n"),
 367                                         oid_to_hex(&c->object.oid));
 368                         break;
 369                 }
 370                 while (parents) {
 371                         struct commit *p = parents->item;
 372                         parse_commit(p);
 373                         if (!(p->object.flags & SEEN))
 374                                 commit_list_insert_by_date(p, &list);
 375                         p->object.flags |= c->object.flags;
 376                         parents = parents->next;
 377
 378                         if (first_parent)
 379                                 break;
 380                 }
 381         }
 382
 383         if (!match_cnt) {
 384                 struct object_id *cmit_oid = &cmit->object.oid;
 385                 if (always) {
 386                         strbuf_addstr(dst, find_unique_abbrev(cmit_oid->hash, abbrev));
 387                         if (suffix)
 388                                 strbuf_addstr(dst, suffix);
 389                         return;
 390                 }
 391                 if (unannotated_cnt)
 392                         die(_("No annotated tags can describe '%s'.\n"
 393                             "However, there were unannotated tags: try --tags."),
 394                             oid_to_hex(cmit_oid));
 395                 else
 396                         die(_("No tags can describe '%s'.\n"
 397                             "Try --always, or create some tags."),
 398                             oid_to_hex(cmit_oid));
 399         }
 400
 401         QSORT(all_matches, match_cnt, compare_pt);
 402
 403         if (gave_up_on) {
 404                 commit_list_insert_by_date(gave_up_on, &list);
 405                 seen_commits--;
 406         }
 407         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 408         free_commit_list(list);
 409
 410         if (debug) {
 411                 static int label_width = -1;
 412                 if (label_width < 0) {
 413                         int i, w;
 414                         for (i = 0; i < ARRAY_SIZE(prio_names); i++) {
 415                                 w = strlen(_(prio_names[i]));
 416                                 if (label_width < w)
 417                                         label_width = w;
 418                         }
 419                 }
 420                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 421                         struct possible_tag *t = &all_matches[cur_match];
 422                         fprintf(stderr, " %-*s %8d %s\n",
 423                                 label_width, _(prio_names[t->name->prio]),
 424                                 t->depth, t->name->path);
 425                 }
 426                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 427                 if (gave_up_on) {
 428                         fprintf(stderr,
 429                                 _("more than %i tags found; listed %i most recent\n"
 430                                 "gave up search at %s\n"),
 431                                 max_candidates, max_candidates,
 432                                 oid_to_hex(&gave_up_on->object.oid));
 433                 }
 434         }
 435
 436         append_name(all_matches[0].name, dst);
 437         if (abbrev)
 438                 append_suffix(all_matches[0].depth, &cmit->object.oid, dst);
 439         if (suffix)
 440                 strbuf_addstr(dst, suffix);
 441 }
 442
 443 struct process_commit_data {
 444         struct object_id current_commit;
 445         struct object_id looking_for;
 446         struct strbuf *dst;
 447         struct rev_info *revs;
 448 };
 449
 450 static void process_commit(struct commit *commit, void *data)
 451 {
 452         struct process_commit_data *pcd = data;
 453         pcd->current_commit = commit->object.oid;
 454 }
 455
 456 static void process_object(struct object *obj, const char *path, void *data)
 457 {
 458         struct process_commit_data *pcd = data;
 459
 460         if (!oidcmp(&pcd->looking_for, &obj->oid) && !pcd->dst->len) {
 461                 reset_revision_walk();
 462                 describe_commit(&pcd->current_commit, pcd->dst);
 463                 strbuf_addf(pcd->dst, ":%s", path);
 464                 free_commit_list(pcd->revs->commits);
 465                 pcd->revs->commits = NULL;
 466         }
 467 }
 468
 469 static void describe_blob(struct object_id oid, struct strbuf *dst)
 470 {
 471         struct rev_info revs;
 472         struct argv_array args = ARGV_ARRAY_INIT;
 473         struct process_commit_data pcd = { null_oid, oid, dst, &revs};
 474
 475         argv_array_pushl(&args, "internal: The first arg is not parsed",
 476                 "--objects", "--in-commit-order", "--reverse", "HEAD",
 477                 NULL);
 478
 479         init_revisions(&revs, NULL);
 480         if (setup_revisions(args.argc, args.argv, &revs, NULL) > 1)
 481                 BUG("setup_revisions could not handle all args?");
 482
 483         if (prepare_revision_walk(&revs))
 484                 die("revision walk setup failed");
 485
 486         traverse_commit_list(&revs, process_commit, process_object, &pcd);
 487         reset_revision_walk();
 488 }
 489
 490 static void describe(const char *arg, int last_one)
 491 {
 492         struct object_id oid;
 493         struct commit *cmit;
 494         struct strbuf sb = STRBUF_INIT;
 495
 496         if (debug)
 497                 fprintf(stderr, _("describe %s\n"), arg);
 498
 499         if (get_oid(arg, &oid))
 500                 die(_("Not a valid object name %s"), arg);
 501         cmit = lookup_commit_reference_gently(&oid, 1);
 502
 503         if (cmit)
 504                 describe_commit(&oid, &sb);
 505         else if (lookup_blob(&oid))
 506                 describe_blob(oid, &sb);
 507         else
 508                 die(_("%s is neither a commit nor blob"), arg);
 509
 510         puts(sb.buf);
 511
 512         if (!last_one)
 513                 clear_commit_marks(cmit, -1);
 514
 515         strbuf_release(&sb);
 516 }
 517
 518 int cmd_describe(int argc, const char **argv, const char *prefix)
 519 {
 520         int contains = 0;
 521         struct option options[] = {
 522                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 523                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
 524                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
 525                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
 526                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
 527                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
 528                 OPT__ABBREV(&abbrev),
 529                 OPT_SET_INT(0, "exact-match", &max_candidates,
 530                             N_("only output exact matches"), 0),
 531                 OPT_INTEGER(0, "candidates", &max_candidates,
 532                             N_("consider <n> most recent tags (default: 10)")),
 533                 OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),
 534                            N_("only consider tags matching <pattern>")),
 535                 OPT_STRING_LIST(0, "exclude", &exclude_patterns, N_("pattern"),
 536                            N_("do not consider tags matching <pattern>")),
 537                 OPT_BOOL(0, "always",        &always,
 538                         N_("show abbreviated commit object as fallback")),
 539                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 540                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 541                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 542                 {OPTION_STRING, 0, "broken",  &broken, N_("mark"),
 543                         N_("append <mark> on broken working tree (default: \"-broken\")"),
 544                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-broken"},
 545                 OPT_END(),
 546         };
 547
 548         git_config(git_default_config, NULL);
 549         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 550         if (abbrev < 0)
 551                 abbrev = DEFAULT_ABBREV;
 552
 553         if (max_candidates < 0)
 554                 max_candidates = 0;
 555         else if (max_candidates > MAX_TAGS)
 556                 max_candidates = MAX_TAGS;
 557
 558         save_commit_buffer = 0;
 559
 560         if (longformat && abbrev == 0)
 561                 die(_("--long is incompatible with --abbrev=0"));
 562
 563         if (contains) {
 564                 struct string_list_item *item;
 565                 struct argv_array args;
 566
 567                 argv_array_init(&args);
 568                 argv_array_pushl(&args, "name-rev",
 569                                  "--peel-tag", "--name-only", "--no-undefined",
 570                                  NULL);
 571                 if (always)
 572                         argv_array_push(&args, "--always");
 573                 if (!all) {
 574                         argv_array_push(&args, "--tags");
 575                         for_each_string_list_item(item, &patterns)
 576                                 argv_array_pushf(&args, "--refs=refs/tags/%s", item->string);
 577                         for_each_string_list_item(item, &exclude_patterns)
 578                                 argv_array_pushf(&args, "--exclude=refs/tags/%s", item->string);
 579                 }
 580                 if (argc)
 581                         argv_array_pushv(&args, argv);
 582                 else
 583                         argv_array_push(&args, "HEAD");
 584                 return cmd_name_rev(args.argc, args.argv, prefix);
 585         }
 586
 587         hashmap_init(&names, commit_name_cmp, NULL, 0);
 588         for_each_rawref(get_name, NULL);
 589         if (!hashmap_get_size(&names) && !always)
 590                 die(_("No names found, cannot describe anything."));
 591
 592         if (argc == 0) {
 593                 if (broken) {
 594                         struct child_process cp = CHILD_PROCESS_INIT;
 595                         argv_array_pushv(&cp.args, diff_index_args);
 596                         cp.git_cmd = 1;
 597                         cp.no_stdin = 1;
 598                         cp.no_stdout = 1;
 599
 600                         if (!dirty)
 601                                 dirty = "-dirty";
 602
 603                         switch (run_command(&cp)) {
 604                         case 0:
 605                                 suffix = NULL;
 606                                 break;
 607                         case 1:
 608                                 suffix = dirty;
 609                                 break;
 610                         default:
 611                                 /* diff-index aborted abnormally */
 612                                 suffix = broken;
 613                         }
 614                 } else if (dirty) {
 615                         static struct lock_file index_lock;
 616                         struct rev_info revs;
 617                         struct argv_array args = ARGV_ARRAY_INIT;
 618                         int fd, result;
 619
 620                         read_cache_preload(NULL);
 621                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 622                                       NULL, NULL, NULL);
 623                         fd = hold_locked_index(&index_lock, 0);
 624                         if (0 <= fd)
 625                                 update_index_if_able(&the_index, &index_lock);
 626
 627                         init_revisions(&revs, prefix);
 628                         argv_array_pushv(&args, diff_index_args);
 629                         if (setup_revisions(args.argc, args.argv, &revs, NULL) != 1)
 630                                 BUG("malformed internal diff-index command line");
 631                         result = run_diff_index(&revs, 0);
 632
 633                         if (!diff_result_code(&revs.diffopt, result))
 634                                 suffix = NULL;
 635                         else
 636                                 suffix = dirty;
 637                 }
 638                 describe("HEAD", 1);
 639         } else if (dirty) {
 640                 die(_("--dirty is incompatible with commit-ishes"));
 641         } else if (broken) {
 642                 die(_("--broken is incompatible with commit-ishes"));
 643         } else {
 644                 while (argc-- > 0)
 645                         describe(*argv++, argc == 0);
 646         }
 647         return 0;
 648 }