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 struct commit_name *cn1,
  59                            const struct commit_name *cn2,
  60                            const void *peeled)
  61 {
  62         return oidcmp(&cn1->peeled, peeled ? peeled : &cn2->peeled);
  63 }
  64
  65 static inline struct commit_name *find_commit_name(const struct object_id *peeled)
  66 {
  67         return hashmap_get_from_hash(&names, sha1hash(peeled->hash), peeled->hash);
  68 }
  69
  70 static int replace_name(struct commit_name *e,
  71                                int prio,
  72                                const struct object_id *oid,
  73                                struct tag **tag)
  74 {
  75         if (!e || e->prio < prio)
  76                 return 1;
  77
  78         if (e->prio == 2 && prio == 2) {
  79                 /* Multiple annotated tags point to the same commit.
  80                  * Select one to keep based upon their tagger date.
  81                  */
  82                 struct tag *t;
  83
  84                 if (!e->tag) {
  85                         t = lookup_tag(&e->oid);
  86                         if (!t || parse_tag(t))
  87                                 return 1;
  88                         e->tag = t;
  89                 }
  90
  91                 t = lookup_tag(oid);
  92                 if (!t || parse_tag(t))
  93                         return 0;
  94                 *tag = t;
  95
  96                 if (e->tag->date < t->date)
  97                         return 1;
  98         }
  99
 100         return 0;
 101 }
 102
 103 static void add_to_known_names(const char *path,
 104                                const struct object_id *peeled,
 105                                int prio,
 106                                const struct object_id *oid)
 107 {
 108         struct commit_name *e = find_commit_name(peeled);
 109         struct tag *tag = NULL;
 110         if (replace_name(e, prio, oid, &tag)) {
 111                 if (!e) {
 112                         e = xmalloc(sizeof(struct commit_name));
 113                         oidcpy(&e->peeled, peeled);
 114                         hashmap_entry_init(e, sha1hash(peeled->hash));
 115                         hashmap_add(&names, e);
 116                         e->path = NULL;
 117                 }
 118                 e->tag = tag;
 119                 e->prio = prio;
 120                 e->name_checked = 0;
 121                 oidcpy(&e->oid, oid);
 122                 free(e->path);
 123                 e->path = xstrdup(path);
 124         }
 125 }
 126
 127 static int get_name(const char *path, const struct object_id *oid, int flag, void *cb_data)
 128 {
 129         int is_tag = starts_with(path, "refs/tags/");
 130         struct object_id peeled;
 131         int is_annotated, prio;
 132
 133         /* Reject anything outside refs/tags/ unless --all */
 134         if (!all && !is_tag)
 135                 return 0;
 136
 137         /*
 138          * If we're given exclude patterns, first exclude any tag which match
 139          * any of the exclude pattern.
 140          */
 141         if (exclude_patterns.nr) {
 142                 struct string_list_item *item;
 143
 144                 if (!is_tag)
 145                         return 0;
 146
 147                 for_each_string_list_item(item, &exclude_patterns) {
 148                         if (!wildmatch(item->string, path + 10, 0))
 149                                 return 0;
 150                 }
 151         }
 152
 153         /*
 154          * If we're given patterns, accept only tags which match at least one
 155          * pattern.
 156          */
 157         if (patterns.nr) {
 158                 struct string_list_item *item;
 159
 160                 if (!is_tag)
 161                         return 0;
 162
 163                 for_each_string_list_item(item, &patterns) {
 164                         if (!wildmatch(item->string, path + 10, 0))
 165                                 break;
 166
 167                         /* If we get here, no pattern matched. */
 168                         return 0;
 169                 }
 170         }
 171
 172         /* Is it annotated? */
 173         if (!peel_ref(path, peeled.hash)) {
 174                 is_annotated = !!oidcmp(oid, &peeled);
 175         } else {
 176                 oidcpy(&peeled, oid);
 177                 is_annotated = 0;
 178         }
 179
 180         /*
 181          * By default, we only use annotated tags, but with --tags
 182          * we fall back to lightweight ones (even without --tags,
 183          * we still remember lightweight ones, only to give hints
 184          * in an error message).  --all allows any refs to be used.
 185          */
 186         if (is_annotated)
 187                 prio = 2;
 188         else if (is_tag)
 189                 prio = 1;
 190         else
 191                 prio = 0;
 192
 193         add_to_known_names(all ? path + 5 : path + 10, &peeled, prio, oid);
 194         return 0;
 195 }
 196
 197 struct possible_tag {
 198         struct commit_name *name;
 199         int depth;
 200         int found_order;
 201         unsigned flag_within;
 202 };
 203
 204 static int compare_pt(const void *a_, const void *b_)
 205 {
 206         struct possible_tag *a = (struct possible_tag *)a_;
 207         struct possible_tag *b = (struct possible_tag *)b_;
 208         if (a->depth != b->depth)
 209                 return a->depth - b->depth;
 210         if (a->found_order != b->found_order)
 211                 return a->found_order - b->found_order;
 212         return 0;
 213 }
 214
 215 static unsigned long finish_depth_computation(
 216         struct commit_list **list,
 217         struct possible_tag *best)
 218 {
 219         unsigned long seen_commits = 0;
 220         while (*list) {
 221                 struct commit *c = pop_commit(list);
 222                 struct commit_list *parents = c->parents;
 223                 seen_commits++;
 224                 if (c->object.flags & best->flag_within) {
 225                         struct commit_list *a = *list;
 226                         while (a) {
 227                                 struct commit *i = a->item;
 228                                 if (!(i->object.flags & best->flag_within))
 229                                         break;
 230                                 a = a->next;
 231                         }
 232                         if (!a)
 233                                 break;
 234                 } else
 235                         best->depth++;
 236                 while (parents) {
 237                         struct commit *p = parents->item;
 238                         parse_commit(p);
 239                         if (!(p->object.flags & SEEN))
 240                                 commit_list_insert_by_date(p, list);
 241                         p->object.flags |= c->object.flags;
 242                         parents = parents->next;
 243                 }
 244         }
 245         return seen_commits;
 246 }
 247
 248 static void display_name(struct commit_name *n)
 249 {
 250         if (n->prio == 2 && !n->tag) {
 251                 n->tag = lookup_tag(&n->oid);
 252                 if (!n->tag || parse_tag(n->tag))
 253                         die(_("annotated tag %s not available"), n->path);
 254         }
 255         if (n->tag && !n->name_checked) {
 256                 if (!n->tag->tag)
 257                         die(_("annotated tag %s has no embedded name"), n->path);
 258                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 259                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 260                 n->name_checked = 1;
 261         }
 262
 263         if (n->tag)
 264                 printf("%s", n->tag->tag);
 265         else
 266                 printf("%s", n->path);
 267 }
 268
 269 static void show_suffix(int depth, const struct object_id *oid)
 270 {
 271         printf("-%d-g%s", depth, find_unique_abbrev(oid->hash, abbrev));
 272 }
 273
 274 static void describe(const char *arg, int last_one)
 275 {
 276         struct object_id oid;
 277         struct commit *cmit, *gave_up_on = NULL;
 278         struct commit_list *list;
 279         struct commit_name *n;
 280         struct possible_tag all_matches[MAX_TAGS];
 281         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 282         unsigned long seen_commits = 0;
 283         unsigned int unannotated_cnt = 0;
 284
 285         if (get_oid(arg, &oid))
 286                 die(_("Not a valid object name %s"), arg);
 287         cmit = lookup_commit_reference(&oid);
 288         if (!cmit)
 289                 die(_("%s is not a valid '%s' object"), arg, commit_type);
 290
 291         n = find_commit_name(&cmit->object.oid);
 292         if (n && (tags || all || n->prio == 2)) {
 293                 /*
 294                  * Exact match to an existing ref.
 295                  */
 296                 display_name(n);
 297                 if (longformat)
 298                         show_suffix(0, n->tag ? &n->tag->tagged->oid : &oid);
 299                 if (suffix)
 300                         printf("%s", suffix);
 301                 printf("\n");
 302                 return;
 303         }
 304
 305         if (!max_candidates)
 306                 die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));
 307         if (debug)
 308                 fprintf(stderr, _("searching to describe %s\n"), arg);
 309
 310         if (!have_util) {
 311                 struct hashmap_iter iter;
 312                 struct commit *c;
 313                 struct commit_name *n = hashmap_iter_first(&names, &iter);
 314                 for (; n; n = hashmap_iter_next(&iter)) {
 315                         c = lookup_commit_reference_gently(&n->peeled, 1);
 316                         if (c)
 317                                 c->util = n;
 318                 }
 319                 have_util = 1;
 320         }
 321
 322         list = NULL;
 323         cmit->object.flags = SEEN;
 324         commit_list_insert(cmit, &list);
 325         while (list) {
 326                 struct commit *c = pop_commit(&list);
 327                 struct commit_list *parents = c->parents;
 328                 seen_commits++;
 329                 n = c->util;
 330                 if (n) {
 331                         if (!tags && !all && n->prio < 2) {
 332                                 unannotated_cnt++;
 333                         } else if (match_cnt < max_candidates) {
 334                                 struct possible_tag *t = &all_matches[match_cnt++];
 335                                 t->name = n;
 336                                 t->depth = seen_commits - 1;
 337                                 t->flag_within = 1u << match_cnt;
 338                                 t->found_order = match_cnt;
 339                                 c->object.flags |= t->flag_within;
 340                                 if (n->prio == 2)
 341                                         annotated_cnt++;
 342                         }
 343                         else {
 344                                 gave_up_on = c;
 345                                 break;
 346                         }
 347                 }
 348                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 349                         struct possible_tag *t = &all_matches[cur_match];
 350                         if (!(c->object.flags & t->flag_within))
 351                                 t->depth++;
 352                 }
 353                 if (annotated_cnt && !list) {
 354                         if (debug)
 355                                 fprintf(stderr, _("finished search at %s\n"),
 356                                         oid_to_hex(&c->object.oid));
 357                         break;
 358                 }
 359                 while (parents) {
 360                         struct commit *p = parents->item;
 361                         parse_commit(p);
 362                         if (!(p->object.flags & SEEN))
 363                                 commit_list_insert_by_date(p, &list);
 364                         p->object.flags |= c->object.flags;
 365                         parents = parents->next;
 366
 367                         if (first_parent)
 368                                 break;
 369                 }
 370         }
 371
 372         if (!match_cnt) {
 373                 struct object_id *oid = &cmit->object.oid;
 374                 if (always) {
 375                         printf("%s", find_unique_abbrev(oid->hash, abbrev));
 376                         if (suffix)
 377                                 printf("%s", suffix);
 378                         printf("\n");
 379                         return;
 380                 }
 381                 if (unannotated_cnt)
 382                         die(_("No annotated tags can describe '%s'.\n"
 383                             "However, there were unannotated tags: try --tags."),
 384                             oid_to_hex(oid));
 385                 else
 386                         die(_("No tags can describe '%s'.\n"
 387                             "Try --always, or create some tags."),
 388                             oid_to_hex(oid));
 389         }
 390
 391         QSORT(all_matches, match_cnt, compare_pt);
 392
 393         if (gave_up_on) {
 394                 commit_list_insert_by_date(gave_up_on, &list);
 395                 seen_commits--;
 396         }
 397         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 398         free_commit_list(list);
 399
 400         if (debug) {
 401                 static int label_width = -1;
 402                 if (label_width < 0) {
 403                         int i, w;
 404                         for (i = 0; i < ARRAY_SIZE(prio_names); i++) {
 405                                 w = strlen(_(prio_names[i]));
 406                                 if (label_width < w)
 407                                         label_width = w;
 408                         }
 409                 }
 410                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 411                         struct possible_tag *t = &all_matches[cur_match];
 412                         fprintf(stderr, " %-*s %8d %s\n",
 413                                 label_width, _(prio_names[t->name->prio]),
 414                                 t->depth, t->name->path);
 415                 }
 416                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 417                 if (gave_up_on) {
 418                         fprintf(stderr,
 419                                 _("more than %i tags found; listed %i most recent\n"
 420                                 "gave up search at %s\n"),
 421                                 max_candidates, max_candidates,
 422                                 oid_to_hex(&gave_up_on->object.oid));
 423                 }
 424         }
 425
 426         display_name(all_matches[0].name);
 427         if (abbrev)
 428                 show_suffix(all_matches[0].depth, &cmit->object.oid);
 429         if (suffix)
 430                 printf("%s", suffix);
 431         printf("\n");
 432
 433         if (!last_one)
 434                 clear_commit_marks(cmit, -1);
 435 }
 436
 437 int cmd_describe(int argc, const char **argv, const char *prefix)
 438 {
 439         int contains = 0;
 440         struct option options[] = {
 441                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 442                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
 443                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
 444                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
 445                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
 446                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
 447                 OPT__ABBREV(&abbrev),
 448                 OPT_SET_INT(0, "exact-match", &max_candidates,
 449                             N_("only output exact matches"), 0),
 450                 OPT_INTEGER(0, "candidates", &max_candidates,
 451                             N_("consider <n> most recent tags (default: 10)")),
 452                 OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),
 453                            N_("only consider tags matching <pattern>")),
 454                 OPT_STRING_LIST(0, "exclude", &exclude_patterns, N_("pattern"),
 455                            N_("do not consider tags matching <pattern>")),
 456                 OPT_BOOL(0, "always",        &always,
 457                         N_("show abbreviated commit object as fallback")),
 458                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 459                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 460                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 461                 {OPTION_STRING, 0, "broken",  &broken, N_("mark"),
 462                         N_("append <mark> on broken working tree (default: \"-broken\")"),
 463                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-broken"},
 464                 OPT_END(),
 465         };
 466
 467         git_config(git_default_config, NULL);
 468         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 469         if (abbrev < 0)
 470                 abbrev = DEFAULT_ABBREV;
 471
 472         if (max_candidates < 0)
 473                 max_candidates = 0;
 474         else if (max_candidates > MAX_TAGS)
 475                 max_candidates = MAX_TAGS;
 476
 477         save_commit_buffer = 0;
 478
 479         if (longformat && abbrev == 0)
 480                 die(_("--long is incompatible with --abbrev=0"));
 481
 482         if (contains) {
 483                 struct string_list_item *item;
 484                 struct argv_array args;
 485
 486                 argv_array_init(&args);
 487                 argv_array_pushl(&args, "name-rev",
 488                                  "--peel-tag", "--name-only", "--no-undefined",
 489                                  NULL);
 490                 if (always)
 491                         argv_array_push(&args, "--always");
 492                 if (!all) {
 493                         argv_array_push(&args, "--tags");
 494                         for_each_string_list_item(item, &patterns)
 495                                 argv_array_pushf(&args, "--refs=refs/tags/%s", item->string);
 496                         for_each_string_list_item(item, &exclude_patterns)
 497                                 argv_array_pushf(&args, "--exclude=refs/tags/%s", item->string);
 498                 }
 499                 if (argc)
 500                         argv_array_pushv(&args, argv);
 501                 else
 502                         argv_array_push(&args, "HEAD");
 503                 return cmd_name_rev(args.argc, args.argv, prefix);
 504         }
 505
 506         hashmap_init(&names, (hashmap_cmp_fn) commit_name_cmp, NULL, 0);
 507         for_each_rawref(get_name, NULL);
 508         if (!names.size && !always)
 509                 die(_("No names found, cannot describe anything."));
 510
 511         if (argc == 0) {
 512                 if (broken) {
 513                         struct child_process cp = CHILD_PROCESS_INIT;
 514                         argv_array_pushv(&cp.args, diff_index_args);
 515                         cp.git_cmd = 1;
 516                         cp.no_stdin = 1;
 517                         cp.no_stdout = 1;
 518
 519                         if (!dirty)
 520                                 dirty = "-dirty";
 521
 522                         switch (run_command(&cp)) {
 523                         case 0:
 524                                 suffix = NULL;
 525                                 break;
 526                         case 1:
 527                                 suffix = dirty;
 528                                 break;
 529                         default:
 530                                 /* diff-index aborted abnormally */
 531                                 suffix = broken;
 532                         }
 533                 } else if (dirty) {
 534                         static struct lock_file index_lock;
 535                         int fd;
 536
 537                         read_cache_preload(NULL);
 538                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 539                                       NULL, NULL, NULL);
 540                         fd = hold_locked_index(&index_lock, 0);
 541                         if (0 <= fd)
 542                                 update_index_if_able(&the_index, &index_lock);
 543
 544                         if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
 545                                             diff_index_args, prefix))
 546                                 suffix = NULL;
 547                         else
 548                                 suffix = dirty;
 549                 }
 550                 describe("HEAD", 1);
 551         } else if (dirty) {
 552                 die(_("--dirty is incompatible with commit-ishes"));
 553         } else if (broken) {
 554                 die(_("--broken is incompatible with commit-ishes"));
 555         } else {
 556                 while (argc-- > 0)
 557                         describe(*argv++, argc == 0);
 558         }
 559         return 0;
 560 }