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