builtin/describe.c

   1 #include "cache.h"
   2 #include "lockfile.h"
   3 #include "commit.h"
   4 #include "tag.h"
   5 #include "refs.h"
   6 #include "builtin.h"
   7 #include "exec_cmd.h"
   8 #include "parse-options.h"
   9 #include "diff.h"
  10 #include "hashmap.h"
  11 #include "argv-array.h"
  12
  13 #define SEEN            (1u << 0)
  14 #define MAX_TAGS        (FLAG_BITS - 1)
  15
  16 static const char * const describe_usage[] = {
  17         N_("git describe [<options>] [<commit-ish>...]"),
  18         N_("git describe [<options>] --dirty"),
  19         NULL
  20 };
  21
  22 static int debug;       /* Display lots of verbose info */
  23 static int all; /* Any valid ref can be used */
  24 static int tags;        /* Allow lightweight tags */
  25 static int longformat;
  26 static int first_parent;
  27 static int abbrev = -1; /* unspecified */
  28 static int max_candidates = 10;
  29 static struct hashmap names;
  30 static int have_util;
  31 static struct string_list patterns = STRING_LIST_INIT_NODUP;
  32 static struct string_list exclude_patterns = STRING_LIST_INIT_NODUP;
  33 static int always;
  34 static const char *dirty;
  35
  36 /* diff-index command arguments to check if working tree is dirty. */
  37 static const char *diff_index_args[] = {
  38         "diff-index", "--quiet", "HEAD", "--", NULL
  39 };
  40
  41 struct commit_name {
  42         struct hashmap_entry entry;
  43         unsigned char peeled[20];
  44         struct tag *tag;
  45         unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  46         unsigned name_checked:1;
  47         unsigned char sha1[20];
  48         char *path;
  49 };
  50
  51 static const char *prio_names[] = {
  52         "head", "lightweight", "annotated",
  53 };
  54
  55 static int commit_name_cmp(const struct commit_name *cn1,
  56                 const struct commit_name *cn2, const void *peeled)
  57 {
  58         return hashcmp(cn1->peeled, peeled ? peeled : cn2->peeled);
  59 }
  60
  61 static inline struct commit_name *find_commit_name(const unsigned char *peeled)
  62 {
  63         return hashmap_get_from_hash(&names, sha1hash(peeled), peeled);
  64 }
  65
  66 static int replace_name(struct commit_name *e,
  67                                int prio,
  68                                const unsigned char *sha1,
  69                                struct tag **tag)
  70 {
  71         if (!e || e->prio < prio)
  72                 return 1;
  73
  74         if (e->prio == 2 && prio == 2) {
  75                 /* Multiple annotated tags point to the same commit.
  76                  * Select one to keep based upon their tagger date.
  77                  */
  78                 struct tag *t;
  79
  80                 if (!e->tag) {
  81                         t = lookup_tag(e->sha1);
  82                         if (!t || parse_tag(t))
  83                                 return 1;
  84                         e->tag = t;
  85                 }
  86
  87                 t = lookup_tag(sha1);
  88                 if (!t || parse_tag(t))
  89                         return 0;
  90                 *tag = t;
  91
  92                 if (e->tag->date < t->date)
  93                         return 1;
  94         }
  95
  96         return 0;
  97 }
  98
  99 static void add_to_known_names(const char *path,
 100                                const unsigned char *peeled,
 101                                int prio,
 102                                const unsigned char *sha1)
 103 {
 104         struct commit_name *e = find_commit_name(peeled);
 105         struct tag *tag = NULL;
 106         if (replace_name(e, prio, sha1, &tag)) {
 107                 if (!e) {
 108                         e = xmalloc(sizeof(struct commit_name));
 109                         hashcpy(e->peeled, peeled);
 110                         hashmap_entry_init(e, sha1hash(peeled));
 111                         hashmap_add(&names, e);
 112                         e->path = NULL;
 113                 }
 114                 e->tag = tag;
 115                 e->prio = prio;
 116                 e->name_checked = 0;
 117                 hashcpy(e->sha1, sha1);
 118                 free(e->path);
 119                 e->path = xstrdup(path);
 120         }
 121 }
 122
 123 static int get_name(const char *path, const struct object_id *oid, int flag, void *cb_data)
 124 {
 125         int is_tag = starts_with(path, "refs/tags/");
 126         struct object_id peeled;
 127         int is_annotated, prio;
 128
 129         /* Reject anything outside refs/tags/ unless --all */
 130         if (!all && !is_tag)
 131                 return 0;
 132
 133         /*
 134          * If we're given exclude patterns, first exclude any tag which match
 135          * any of the exclude pattern.
 136          */
 137         if (exclude_patterns.nr) {
 138                 struct string_list_item *item;
 139
 140                 if (!is_tag)
 141                         return 0;
 142
 143                 for_each_string_list_item(item, &exclude_patterns) {
 144                         if (!wildmatch(item->string, path + 10, 0, NULL))
 145                                 return 0;
 146                 }
 147         }
 148
 149         /*
 150          * If we're given patterns, accept only tags which match at least one
 151          * pattern.
 152          */
 153         if (patterns.nr) {
 154                 struct string_list_item *item;
 155
 156                 if (!is_tag)
 157                         return 0;
 158
 159                 for_each_string_list_item(item, &patterns) {
 160                         if (!wildmatch(item->string, path + 10, 0, NULL))
 161                                 break;
 162
 163                         /* If we get here, no pattern matched. */
 164                         return 0;
 165                 }
 166         }
 167
 168         /* Is it annotated? */
 169         if (!peel_ref(path, peeled.hash)) {
 170                 is_annotated = !!oidcmp(oid, &peeled);
 171         } else {
 172                 oidcpy(&peeled, oid);
 173                 is_annotated = 0;
 174         }
 175
 176         /*
 177          * By default, we only use annotated tags, but with --tags
 178          * we fall back to lightweight ones (even without --tags,
 179          * we still remember lightweight ones, only to give hints
 180          * in an error message).  --all allows any refs to be used.
 181          */
 182         if (is_annotated)
 183                 prio = 2;
 184         else if (is_tag)
 185                 prio = 1;
 186         else
 187                 prio = 0;
 188
 189         add_to_known_names(all ? path + 5 : path + 10, peeled.hash, prio, oid->hash);
 190         return 0;
 191 }
 192
 193 struct possible_tag {
 194         struct commit_name *name;
 195         int depth;
 196         int found_order;
 197         unsigned flag_within;
 198 };
 199
 200 static int compare_pt(const void *a_, const void *b_)
 201 {
 202         struct possible_tag *a = (struct possible_tag *)a_;
 203         struct possible_tag *b = (struct possible_tag *)b_;
 204         if (a->depth != b->depth)
 205                 return a->depth - b->depth;
 206         if (a->found_order != b->found_order)
 207                 return a->found_order - b->found_order;
 208         return 0;
 209 }
 210
 211 static unsigned long finish_depth_computation(
 212         struct commit_list **list,
 213         struct possible_tag *best)
 214 {
 215         unsigned long seen_commits = 0;
 216         while (*list) {
 217                 struct commit *c = pop_commit(list);
 218                 struct commit_list *parents = c->parents;
 219                 seen_commits++;
 220                 if (c->object.flags & best->flag_within) {
 221                         struct commit_list *a = *list;
 222                         while (a) {
 223                                 struct commit *i = a->item;
 224                                 if (!(i->object.flags & best->flag_within))
 225                                         break;
 226                                 a = a->next;
 227                         }
 228                         if (!a)
 229                                 break;
 230                 } else
 231                         best->depth++;
 232                 while (parents) {
 233                         struct commit *p = parents->item;
 234                         parse_commit(p);
 235                         if (!(p->object.flags & SEEN))
 236                                 commit_list_insert_by_date(p, list);
 237                         p->object.flags |= c->object.flags;
 238                         parents = parents->next;
 239                 }
 240         }
 241         return seen_commits;
 242 }
 243
 244 static void display_name(struct commit_name *n)
 245 {
 246         if (n->prio == 2 && !n->tag) {
 247                 n->tag = lookup_tag(n->sha1);
 248                 if (!n->tag || parse_tag(n->tag))
 249                         die(_("annotated tag %s not available"), n->path);
 250         }
 251         if (n->tag && !n->name_checked) {
 252                 if (!n->tag->tag)
 253                         die(_("annotated tag %s has no embedded name"), n->path);
 254                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 255                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 256                 n->name_checked = 1;
 257         }
 258
 259         if (n->tag)
 260                 printf("%s", n->tag->tag);
 261         else
 262                 printf("%s", n->path);
 263 }
 264
 265 static void show_suffix(int depth, const unsigned char *sha1)
 266 {
 267         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 268 }
 269
 270 static void describe(const char *arg, int last_one)
 271 {
 272         unsigned char sha1[20];
 273         struct commit *cmit, *gave_up_on = NULL;
 274         struct commit_list *list;
 275         struct commit_name *n;
 276         struct possible_tag all_matches[MAX_TAGS];
 277         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 278         unsigned long seen_commits = 0;
 279         unsigned int unannotated_cnt = 0;
 280
 281         if (get_sha1(arg, sha1))
 282                 die(_("Not a valid object name %s"), arg);
 283         cmit = lookup_commit_reference(sha1);
 284         if (!cmit)
 285                 die(_("%s is not a valid '%s' object"), arg, commit_type);
 286
 287         n = find_commit_name(cmit->object.oid.hash);
 288         if (n && (tags || all || n->prio == 2)) {
 289                 /*
 290                  * Exact match to an existing ref.
 291                  */
 292                 display_name(n);
 293                 if (longformat)
 294                         show_suffix(0, n->tag ? n->tag->tagged->oid.hash : sha1);
 295                 if (dirty)
 296                         printf("%s", dirty);
 297                 printf("\n");
 298                 return;
 299         }
 300
 301         if (!max_candidates)
 302                 die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));
 303         if (debug)
 304                 fprintf(stderr, _("searching to describe %s\n"), arg);
 305
 306         if (!have_util) {
 307                 struct hashmap_iter iter;
 308                 struct commit *c;
 309                 struct commit_name *n = hashmap_iter_first(&names, &iter);
 310                 for (; n; n = hashmap_iter_next(&iter)) {
 311                         c = lookup_commit_reference_gently(n->peeled, 1);
 312                         if (c)
 313                                 c->util = n;
 314                 }
 315                 have_util = 1;
 316         }
 317
 318         list = NULL;
 319         cmit->object.flags = SEEN;
 320         commit_list_insert(cmit, &list);
 321         while (list) {
 322                 struct commit *c = pop_commit(&list);
 323                 struct commit_list *parents = c->parents;
 324                 seen_commits++;
 325                 n = c->util;
 326                 if (n) {
 327                         if (!tags && !all && n->prio < 2) {
 328                                 unannotated_cnt++;
 329                         } else if (match_cnt < max_candidates) {
 330                                 struct possible_tag *t = &all_matches[match_cnt++];
 331                                 t->name = n;
 332                                 t->depth = seen_commits - 1;
 333                                 t->flag_within = 1u << match_cnt;
 334                                 t->found_order = match_cnt;
 335                                 c->object.flags |= t->flag_within;
 336                                 if (n->prio == 2)
 337                                         annotated_cnt++;
 338                         }
 339                         else {
 340                                 gave_up_on = c;
 341                                 break;
 342                         }
 343                 }
 344                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 345                         struct possible_tag *t = &all_matches[cur_match];
 346                         if (!(c->object.flags & t->flag_within))
 347                                 t->depth++;
 348                 }
 349                 if (annotated_cnt && !list) {
 350                         if (debug)
 351                                 fprintf(stderr, _("finished search at %s\n"),
 352                                         oid_to_hex(&c->object.oid));
 353                         break;
 354                 }
 355                 while (parents) {
 356                         struct commit *p = parents->item;
 357                         parse_commit(p);
 358                         if (!(p->object.flags & SEEN))
 359                                 commit_list_insert_by_date(p, &list);
 360                         p->object.flags |= c->object.flags;
 361                         parents = parents->next;
 362
 363                         if (first_parent)
 364                                 break;
 365                 }
 366         }
 367
 368         if (!match_cnt) {
 369                 struct object_id *oid = &cmit->object.oid;
 370                 if (always) {
 371                         printf("%s", find_unique_abbrev(oid->hash, abbrev));
 372                         if (dirty)
 373                                 printf("%s", dirty);
 374                         printf("\n");
 375                         return;
 376                 }
 377                 if (unannotated_cnt)
 378                         die(_("No annotated tags can describe '%s'.\n"
 379                             "However, there were unannotated tags: try --tags."),
 380                             oid_to_hex(oid));
 381                 else
 382                         die(_("No tags can describe '%s'.\n"
 383                             "Try --always, or create some tags."),
 384                             oid_to_hex(oid));
 385         }
 386
 387         QSORT(all_matches, match_cnt, compare_pt);
 388
 389         if (gave_up_on) {
 390                 commit_list_insert_by_date(gave_up_on, &list);
 391                 seen_commits--;
 392         }
 393         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 394         free_commit_list(list);
 395
 396         if (debug) {
 397                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 398                         struct possible_tag *t = &all_matches[cur_match];
 399                         fprintf(stderr, " %-11s %8d %s\n",
 400                                 prio_names[t->name->prio],
 401                                 t->depth, t->name->path);
 402                 }
 403                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 404                 if (gave_up_on) {
 405                         fprintf(stderr,
 406                                 _("more than %i tags found; listed %i most recent\n"
 407                                 "gave up search at %s\n"),
 408                                 max_candidates, max_candidates,
 409                                 oid_to_hex(&gave_up_on->object.oid));
 410                 }
 411         }
 412
 413         display_name(all_matches[0].name);
 414         if (abbrev)
 415                 show_suffix(all_matches[0].depth, cmit->object.oid.hash);
 416         if (dirty)
 417                 printf("%s", dirty);
 418         printf("\n");
 419
 420         if (!last_one)
 421                 clear_commit_marks(cmit, -1);
 422 }
 423
 424 int cmd_describe(int argc, const char **argv, const char *prefix)
 425 {
 426         int contains = 0;
 427         struct option options[] = {
 428                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 429                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
 430                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
 431                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
 432                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
 433                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
 434                 OPT__ABBREV(&abbrev),
 435                 OPT_SET_INT(0, "exact-match", &max_candidates,
 436                             N_("only output exact matches"), 0),
 437                 OPT_INTEGER(0, "candidates", &max_candidates,
 438                             N_("consider <n> most recent tags (default: 10)")),
 439                 OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),
 440                            N_("only consider tags matching <pattern>")),
 441                 OPT_STRING_LIST(0, "exclude", &exclude_patterns, N_("pattern"),
 442                            N_("do not consider tags matching <pattern>")),
 443                 OPT_BOOL(0, "always",        &always,
 444                         N_("show abbreviated commit object as fallback")),
 445                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 446                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 447                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 448                 OPT_END(),
 449         };
 450
 451         git_config(git_default_config, NULL);
 452         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 453         if (abbrev < 0)
 454                 abbrev = DEFAULT_ABBREV;
 455
 456         if (max_candidates < 0)
 457                 max_candidates = 0;
 458         else if (max_candidates > MAX_TAGS)
 459                 max_candidates = MAX_TAGS;
 460
 461         save_commit_buffer = 0;
 462
 463         if (longformat && abbrev == 0)
 464                 die(_("--long is incompatible with --abbrev=0"));
 465
 466         if (contains) {
 467                 struct string_list_item *item;
 468                 struct argv_array args;
 469
 470                 argv_array_init(&args);
 471                 argv_array_pushl(&args, "name-rev",
 472                                  "--peel-tag", "--name-only", "--no-undefined",
 473                                  NULL);
 474                 if (always)
 475                         argv_array_push(&args, "--always");
 476                 if (!all) {
 477                         argv_array_push(&args, "--tags");
 478                         for_each_string_list_item(item, &patterns)
 479                                 argv_array_pushf(&args, "--refs=refs/tags/%s", item->string);
 480                         for_each_string_list_item(item, &exclude_patterns)
 481                                 argv_array_pushf(&args, "--exclude=refs/tags/%s", item->string);
 482                 }
 483                 if (argc)
 484                         argv_array_pushv(&args, argv);
 485                 else
 486                         argv_array_push(&args, "HEAD");
 487                 return cmd_name_rev(args.argc, args.argv, prefix);
 488         }
 489
 490         hashmap_init(&names, (hashmap_cmp_fn) commit_name_cmp, 0);
 491         for_each_rawref(get_name, NULL);
 492         if (!names.size && !always)
 493                 die(_("No names found, cannot describe anything."));
 494
 495         if (argc == 0) {
 496                 if (dirty) {
 497                         static struct lock_file index_lock;
 498                         int fd;
 499
 500                         read_cache_preload(NULL);
 501                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 502                                       NULL, NULL, NULL);
 503                         fd = hold_locked_index(&index_lock, 0);
 504                         if (0 <= fd)
 505                                 update_index_if_able(&the_index, &index_lock);
 506
 507                         if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
 508                                             diff_index_args, prefix))
 509                                 dirty = NULL;
 510                 }
 511                 describe("HEAD", 1);
 512         } else if (dirty) {
 513                 die(_("--dirty is incompatible with commit-ishes"));
 514         } else {
 515                 while (argc-- > 0)
 516                         describe(*argv++, argc == 0);
 517         }
 518         return 0;
 519 }