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                 int found = 0;
 155                 struct string_list_item *item;
 156
 157                 if (!is_tag)
 158                         return 0;
 159
 160                 for_each_string_list_item(item, &patterns) {
 161                         if (!wildmatch(item->string, path + 10, 0, NULL)) {
 162                                 found = 1;
 163                                 break;
 164                         }
 165                 }
 166
 167                 if (!found)
 168                         return 0;
 169         }
 170
 171         /* Is it annotated? */
 172         if (!peel_ref(path, peeled.hash)) {
 173                 is_annotated = !!oidcmp(oid, &peeled);
 174         } else {
 175                 oidcpy(&peeled, oid);
 176                 is_annotated = 0;
 177         }
 178
 179         /*
 180          * By default, we only use annotated tags, but with --tags
 181          * we fall back to lightweight ones (even without --tags,
 182          * we still remember lightweight ones, only to give hints
 183          * in an error message).  --all allows any refs to be used.
 184          */
 185         if (is_annotated)
 186                 prio = 2;
 187         else if (is_tag)
 188                 prio = 1;
 189         else
 190                 prio = 0;
 191
 192         add_to_known_names(all ? path + 5 : path + 10, peeled.hash, prio, oid->hash);
 193         return 0;
 194 }
 195
 196 struct possible_tag {
 197         struct commit_name *name;
 198         int depth;
 199         int found_order;
 200         unsigned flag_within;
 201 };
 202
 203 static int compare_pt(const void *a_, const void *b_)
 204 {
 205         struct possible_tag *a = (struct possible_tag *)a_;
 206         struct possible_tag *b = (struct possible_tag *)b_;
 207         if (a->depth != b->depth)
 208                 return a->depth - b->depth;
 209         if (a->found_order != b->found_order)
 210                 return a->found_order - b->found_order;
 211         return 0;
 212 }
 213
 214 static unsigned long finish_depth_computation(
 215         struct commit_list **list,
 216         struct possible_tag *best)
 217 {
 218         unsigned long seen_commits = 0;
 219         while (*list) {
 220                 struct commit *c = pop_commit(list);
 221                 struct commit_list *parents = c->parents;
 222                 seen_commits++;
 223                 if (c->object.flags & best->flag_within) {
 224                         struct commit_list *a = *list;
 225                         while (a) {
 226                                 struct commit *i = a->item;
 227                                 if (!(i->object.flags & best->flag_within))
 228                                         break;
 229                                 a = a->next;
 230                         }
 231                         if (!a)
 232                                 break;
 233                 } else
 234                         best->depth++;
 235                 while (parents) {
 236                         struct commit *p = parents->item;
 237                         parse_commit(p);
 238                         if (!(p->object.flags & SEEN))
 239                                 commit_list_insert_by_date(p, list);
 240                         p->object.flags |= c->object.flags;
 241                         parents = parents->next;
 242                 }
 243         }
 244         return seen_commits;
 245 }
 246
 247 static void display_name(struct commit_name *n)
 248 {
 249         if (n->prio == 2 && !n->tag) {
 250                 n->tag = lookup_tag(n->sha1);
 251                 if (!n->tag || parse_tag(n->tag))
 252                         die(_("annotated tag %s not available"), n->path);
 253         }
 254         if (n->tag && !n->name_checked) {
 255                 if (!n->tag->tag)
 256                         die(_("annotated tag %s has no embedded name"), n->path);
 257                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 258                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 259                 n->name_checked = 1;
 260         }
 261
 262         if (n->tag)
 263                 printf("%s", n->tag->tag);
 264         else
 265                 printf("%s", n->path);
 266 }
 267
 268 static void show_suffix(int depth, const unsigned char *sha1)
 269 {
 270         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 271 }
 272
 273 static void describe(const char *arg, int last_one)
 274 {
 275         unsigned char sha1[20];
 276         struct commit *cmit, *gave_up_on = NULL;
 277         struct commit_list *list;
 278         struct commit_name *n;
 279         struct possible_tag all_matches[MAX_TAGS];
 280         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 281         unsigned long seen_commits = 0;
 282         unsigned int unannotated_cnt = 0;
 283
 284         if (get_sha1(arg, sha1))
 285                 die(_("Not a valid object name %s"), arg);
 286         cmit = lookup_commit_reference(sha1);
 287         if (!cmit)
 288                 die(_("%s is not a valid '%s' object"), arg, commit_type);
 289
 290         n = find_commit_name(cmit->object.oid.hash);
 291         if (n && (tags || all || n->prio == 2)) {
 292                 /*
 293                  * Exact match to an existing ref.
 294                  */
 295                 display_name(n);
 296                 if (longformat)
 297                         show_suffix(0, n->tag ? n->tag->tagged->oid.hash : sha1);
 298                 if (dirty)
 299                         printf("%s", dirty);
 300                 printf("\n");
 301                 return;
 302         }
 303
 304         if (!max_candidates)
 305                 die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));
 306         if (debug)
 307                 fprintf(stderr, _("searching to describe %s\n"), arg);
 308
 309         if (!have_util) {
 310                 struct hashmap_iter iter;
 311                 struct commit *c;
 312                 struct commit_name *n = hashmap_iter_first(&names, &iter);
 313                 for (; n; n = hashmap_iter_next(&iter)) {
 314                         c = lookup_commit_reference_gently(n->peeled, 1);
 315                         if (c)
 316                                 c->util = n;
 317                 }
 318                 have_util = 1;
 319         }
 320
 321         list = NULL;
 322         cmit->object.flags = SEEN;
 323         commit_list_insert(cmit, &list);
 324         while (list) {
 325                 struct commit *c = pop_commit(&list);
 326                 struct commit_list *parents = c->parents;
 327                 seen_commits++;
 328                 n = c->util;
 329                 if (n) {
 330                         if (!tags && !all && n->prio < 2) {
 331                                 unannotated_cnt++;
 332                         } else if (match_cnt < max_candidates) {
 333                                 struct possible_tag *t = &all_matches[match_cnt++];
 334                                 t->name = n;
 335                                 t->depth = seen_commits - 1;
 336                                 t->flag_within = 1u << match_cnt;
 337                                 t->found_order = match_cnt;
 338                                 c->object.flags |= t->flag_within;
 339                                 if (n->prio == 2)
 340                                         annotated_cnt++;
 341                         }
 342                         else {
 343                                 gave_up_on = c;
 344                                 break;
 345                         }
 346                 }
 347                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 348                         struct possible_tag *t = &all_matches[cur_match];
 349                         if (!(c->object.flags & t->flag_within))
 350                                 t->depth++;
 351                 }
 352                 if (annotated_cnt && !list) {
 353                         if (debug)
 354                                 fprintf(stderr, _("finished search at %s\n"),
 355                                         oid_to_hex(&c->object.oid));
 356                         break;
 357                 }
 358                 while (parents) {
 359                         struct commit *p = parents->item;
 360                         parse_commit(p);
 361                         if (!(p->object.flags & SEEN))
 362                                 commit_list_insert_by_date(p, &list);
 363                         p->object.flags |= c->object.flags;
 364                         parents = parents->next;
 365
 366                         if (first_parent)
 367                                 break;
 368                 }
 369         }
 370
 371         if (!match_cnt) {
 372                 struct object_id *oid = &cmit->object.oid;
 373                 if (always) {
 374                         printf("%s", find_unique_abbrev(oid->hash, abbrev));
 375                         if (dirty)
 376                                 printf("%s", dirty);
 377                         printf("\n");
 378                         return;
 379                 }
 380                 if (unannotated_cnt)
 381                         die(_("No annotated tags can describe '%s'.\n"
 382                             "However, there were unannotated tags: try --tags."),
 383                             oid_to_hex(oid));
 384                 else
 385                         die(_("No tags can describe '%s'.\n"
 386                             "Try --always, or create some tags."),
 387                             oid_to_hex(oid));
 388         }
 389
 390         QSORT(all_matches, match_cnt, compare_pt);
 391
 392         if (gave_up_on) {
 393                 commit_list_insert_by_date(gave_up_on, &list);
 394                 seen_commits--;
 395         }
 396         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 397         free_commit_list(list);
 398
 399         if (debug) {
 400                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 401                         struct possible_tag *t = &all_matches[cur_match];
 402                         fprintf(stderr, " %-11s %8d %s\n",
 403                                 prio_names[t->name->prio],
 404                                 t->depth, t->name->path);
 405                 }
 406                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 407                 if (gave_up_on) {
 408                         fprintf(stderr,
 409                                 _("more than %i tags found; listed %i most recent\n"
 410                                 "gave up search at %s\n"),
 411                                 max_candidates, max_candidates,
 412                                 oid_to_hex(&gave_up_on->object.oid));
 413                 }
 414         }
 415
 416         display_name(all_matches[0].name);
 417         if (abbrev)
 418                 show_suffix(all_matches[0].depth, cmit->object.oid.hash);
 419         if (dirty)
 420                 printf("%s", dirty);
 421         printf("\n");
 422
 423         if (!last_one)
 424                 clear_commit_marks(cmit, -1);
 425 }
 426
 427 int cmd_describe(int argc, const char **argv, const char *prefix)
 428 {
 429         int contains = 0;
 430         struct option options[] = {
 431                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 432                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
 433                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
 434                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
 435                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
 436                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
 437                 OPT__ABBREV(&abbrev),
 438                 OPT_SET_INT(0, "exact-match", &max_candidates,
 439                             N_("only output exact matches"), 0),
 440                 OPT_INTEGER(0, "candidates", &max_candidates,
 441                             N_("consider <n> most recent tags (default: 10)")),
 442                 OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),
 443                            N_("only consider tags matching <pattern>")),
 444                 OPT_STRING_LIST(0, "exclude", &exclude_patterns, N_("pattern"),
 445                            N_("do not consider tags matching <pattern>")),
 446                 OPT_BOOL(0, "always",        &always,
 447                         N_("show abbreviated commit object as fallback")),
 448                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 449                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 450                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 451                 OPT_END(),
 452         };
 453
 454         git_config(git_default_config, NULL);
 455         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 456         if (abbrev < 0)
 457                 abbrev = DEFAULT_ABBREV;
 458
 459         if (max_candidates < 0)
 460                 max_candidates = 0;
 461         else if (max_candidates > MAX_TAGS)
 462                 max_candidates = MAX_TAGS;
 463
 464         save_commit_buffer = 0;
 465
 466         if (longformat && abbrev == 0)
 467                 die(_("--long is incompatible with --abbrev=0"));
 468
 469         if (contains) {
 470                 struct string_list_item *item;
 471                 struct argv_array args;
 472
 473                 argv_array_init(&args);
 474                 argv_array_pushl(&args, "name-rev",
 475                                  "--peel-tag", "--name-only", "--no-undefined",
 476                                  NULL);
 477                 if (always)
 478                         argv_array_push(&args, "--always");
 479                 if (!all) {
 480                         argv_array_push(&args, "--tags");
 481                         for_each_string_list_item(item, &patterns)
 482                                 argv_array_pushf(&args, "--refs=refs/tags/%s", item->string);
 483                         for_each_string_list_item(item, &exclude_patterns)
 484                                 argv_array_pushf(&args, "--exclude=refs/tags/%s", item->string);
 485                 }
 486                 if (argc)
 487                         argv_array_pushv(&args, argv);
 488                 else
 489                         argv_array_push(&args, "HEAD");
 490                 return cmd_name_rev(args.argc, args.argv, prefix);
 491         }
 492
 493         hashmap_init(&names, (hashmap_cmp_fn) commit_name_cmp, 0);
 494         for_each_rawref(get_name, NULL);
 495         if (!names.size && !always)
 496                 die(_("No names found, cannot describe anything."));
 497
 498         if (argc == 0) {
 499                 if (dirty) {
 500                         static struct lock_file index_lock;
 501                         int fd;
 502
 503                         read_cache_preload(NULL);
 504                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 505                                       NULL, NULL, NULL);
 506                         fd = hold_locked_index(&index_lock, 0);
 507                         if (0 <= fd)
 508                                 update_index_if_able(&the_index, &index_lock);
 509
 510                         if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
 511                                             diff_index_args, prefix))
 512                                 dirty = NULL;
 513                 }
 514                 describe("HEAD", 1);
 515         } else if (dirty) {
 516                 die(_("--dirty is incompatible with commit-ishes"));
 517         } else {
 518                 while (argc-- > 0)
 519                         describe(*argv++, argc == 0);
 520         }
 521         return 0;
 522 }