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