builtin/describe.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "tag.h"
   4 #include "refs.h"
   5 #include "builtin.h"
   6 #include "exec_cmd.h"
   7 #include "parse-options.h"
   8 #include "diff.h"
   9 #include "hashmap.h"
  10 #include "argv-array.h"
  11
  12 #define SEEN            (1u << 0)
  13 #define MAX_TAGS        (FLAG_BITS - 1)
  14
  15 static const char * const describe_usage[] = {
  16         N_("git describe [options] <commit-ish>*"),
  17         N_("git describe [options] --dirty"),
  18         NULL
  19 };
  20
  21 static int debug;       /* Display lots of verbose info */
  22 static int all; /* Any valid ref can be used */
  23 static int tags;        /* Allow lightweight tags */
  24 static int longformat;
  25 static int first_parent;
  26 static int abbrev = -1; /* unspecified */
  27 static int max_candidates = 10;
  28 static struct hashmap names;
  29 static int have_util;
  30 static const char *pattern;
  31 static int always;
  32 static const char *dirty;
  33
  34 /* diff-index command arguments to check if working tree is dirty. */
  35 static const char *diff_index_args[] = {
  36         "diff-index", "--quiet", "HEAD", "--", NULL
  37 };
  38
  39 struct commit_name {
  40         struct hashmap_entry entry;
  41         unsigned char peeled[20];
  42         struct tag *tag;
  43         unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  44         unsigned name_checked:1;
  45         unsigned char sha1[20];
  46         char *path;
  47 };
  48
  49 static const char *prio_names[] = {
  50         "head", "lightweight", "annotated",
  51 };
  52
  53 static int commit_name_cmp(const struct commit_name *cn1,
  54                 const struct commit_name *cn2, const void *peeled)
  55 {
  56         return hashcmp(cn1->peeled, peeled ? peeled : cn2->peeled);
  57 }
  58
  59 static inline unsigned int hash_sha1(const unsigned char *sha1)
  60 {
  61         unsigned int hash;
  62         memcpy(&hash, sha1, sizeof(hash));
  63         return hash;
  64 }
  65
  66 static inline struct commit_name *find_commit_name(const unsigned char *peeled)
  67 {
  68         struct commit_name key;
  69         hashmap_entry_init(&key, hash_sha1(peeled));
  70         return hashmap_get(&names, &key, peeled);
  71 }
  72
  73 static int replace_name(struct commit_name *e,
  74                                int prio,
  75                                const unsigned char *sha1,
  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->sha1);
  89                         if (!t || parse_tag(t))
  90                                 return 1;
  91                         e->tag = t;
  92                 }
  93
  94                 t = lookup_tag(sha1);
  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 unsigned char *peeled,
 108                                int prio,
 109                                const unsigned char *sha1)
 110 {
 111         struct commit_name *e = find_commit_name(peeled);
 112         struct tag *tag = NULL;
 113         if (replace_name(e, prio, sha1, &tag)) {
 114                 if (!e) {
 115                         e = xmalloc(sizeof(struct commit_name));
 116                         hashcpy(e->peeled, peeled);
 117                         hashmap_entry_init(e, hash_sha1(peeled));
 118                         hashmap_add(&names, e);
 119                         e->path = NULL;
 120                 }
 121                 e->tag = tag;
 122                 e->prio = prio;
 123                 e->name_checked = 0;
 124                 hashcpy(e->sha1, sha1);
 125                 free(e->path);
 126                 e->path = xstrdup(path);
 127         }
 128 }
 129
 130 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 131 {
 132         int is_tag = starts_with(path, "refs/tags/");
 133         unsigned char peeled[20];
 134         int is_annotated, prio;
 135
 136         /* Reject anything outside refs/tags/ unless --all */
 137         if (!all && !is_tag)
 138                 return 0;
 139
 140         /* Accept only tags that match the pattern, if given */
 141         if (pattern && (!is_tag || wildmatch(pattern, path + 10, 0, NULL)))
 142                 return 0;
 143
 144         /* Is it annotated? */
 145         if (!peel_ref(path, peeled)) {
 146                 is_annotated = !!hashcmp(sha1, peeled);
 147         } else {
 148                 hashcpy(peeled, sha1);
 149                 is_annotated = 0;
 150         }
 151
 152         /*
 153          * By default, we only use annotated tags, but with --tags
 154          * we fall back to lightweight ones (even without --tags,
 155          * we still remember lightweight ones, only to give hints
 156          * in an error message).  --all allows any refs to be used.
 157          */
 158         if (is_annotated)
 159                 prio = 2;
 160         else if (is_tag)
 161                 prio = 1;
 162         else
 163                 prio = 0;
 164
 165         add_to_known_names(all ? path + 5 : path + 10, peeled, prio, sha1);
 166         return 0;
 167 }
 168
 169 struct possible_tag {
 170         struct commit_name *name;
 171         int depth;
 172         int found_order;
 173         unsigned flag_within;
 174 };
 175
 176 static int compare_pt(const void *a_, const void *b_)
 177 {
 178         struct possible_tag *a = (struct possible_tag *)a_;
 179         struct possible_tag *b = (struct possible_tag *)b_;
 180         if (a->depth != b->depth)
 181                 return a->depth - b->depth;
 182         if (a->found_order != b->found_order)
 183                 return a->found_order - b->found_order;
 184         return 0;
 185 }
 186
 187 static unsigned long finish_depth_computation(
 188         struct commit_list **list,
 189         struct possible_tag *best)
 190 {
 191         unsigned long seen_commits = 0;
 192         while (*list) {
 193                 struct commit *c = pop_commit(list);
 194                 struct commit_list *parents = c->parents;
 195                 seen_commits++;
 196                 if (c->object.flags & best->flag_within) {
 197                         struct commit_list *a = *list;
 198                         while (a) {
 199                                 struct commit *i = a->item;
 200                                 if (!(i->object.flags & best->flag_within))
 201                                         break;
 202                                 a = a->next;
 203                         }
 204                         if (!a)
 205                                 break;
 206                 } else
 207                         best->depth++;
 208                 while (parents) {
 209                         struct commit *p = parents->item;
 210                         parse_commit(p);
 211                         if (!(p->object.flags & SEEN))
 212                                 commit_list_insert_by_date(p, list);
 213                         p->object.flags |= c->object.flags;
 214                         parents = parents->next;
 215                 }
 216         }
 217         return seen_commits;
 218 }
 219
 220 static void display_name(struct commit_name *n)
 221 {
 222         if (n->prio == 2 && !n->tag) {
 223                 n->tag = lookup_tag(n->sha1);
 224                 if (!n->tag || parse_tag(n->tag))
 225                         die(_("annotated tag %s not available"), n->path);
 226         }
 227         if (n->tag && !n->name_checked) {
 228                 if (!n->tag->tag)
 229                         die(_("annotated tag %s has no embedded name"), n->path);
 230                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 231                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 232                 n->name_checked = 1;
 233         }
 234
 235         if (n->tag)
 236                 printf("%s", n->tag->tag);
 237         else
 238                 printf("%s", n->path);
 239 }
 240
 241 static void show_suffix(int depth, const unsigned char *sha1)
 242 {
 243         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 244 }
 245
 246 static void describe(const char *arg, int last_one)
 247 {
 248         unsigned char sha1[20];
 249         struct commit *cmit, *gave_up_on = NULL;
 250         struct commit_list *list;
 251         struct commit_name *n;
 252         struct possible_tag all_matches[MAX_TAGS];
 253         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 254         unsigned long seen_commits = 0;
 255         unsigned int unannotated_cnt = 0;
 256
 257         if (get_sha1(arg, sha1))
 258                 die(_("Not a valid object name %s"), arg);
 259         cmit = lookup_commit_reference(sha1);
 260         if (!cmit)
 261                 die(_("%s is not a valid '%s' object"), arg, commit_type);
 262
 263         n = find_commit_name(cmit->object.sha1);
 264         if (n && (tags || all || n->prio == 2)) {
 265                 /*
 266                  * Exact match to an existing ref.
 267                  */
 268                 display_name(n);
 269                 if (longformat)
 270                         show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 271                 if (dirty)
 272                         printf("%s", dirty);
 273                 printf("\n");
 274                 return;
 275         }
 276
 277         if (!max_candidates)
 278                 die(_("no tag exactly matches '%s'"), sha1_to_hex(cmit->object.sha1));
 279         if (debug)
 280                 fprintf(stderr, _("searching to describe %s\n"), arg);
 281
 282         if (!have_util) {
 283                 struct hashmap_iter iter;
 284                 struct commit *c;
 285                 struct commit_name *n = hashmap_iter_first(&names, &iter);
 286                 for (; n; n = hashmap_iter_next(&iter)) {
 287                         c = lookup_commit_reference_gently(n->peeled, 1);
 288                         if (c)
 289                                 c->util = n;
 290                 }
 291                 have_util = 1;
 292         }
 293
 294         list = NULL;
 295         cmit->object.flags = SEEN;
 296         commit_list_insert(cmit, &list);
 297         while (list) {
 298                 struct commit *c = pop_commit(&list);
 299                 struct commit_list *parents = c->parents;
 300                 seen_commits++;
 301                 n = c->util;
 302                 if (n) {
 303                         if (!tags && !all && n->prio < 2) {
 304                                 unannotated_cnt++;
 305                         } else if (match_cnt < max_candidates) {
 306                                 struct possible_tag *t = &all_matches[match_cnt++];
 307                                 t->name = n;
 308                                 t->depth = seen_commits - 1;
 309                                 t->flag_within = 1u << match_cnt;
 310                                 t->found_order = match_cnt;
 311                                 c->object.flags |= t->flag_within;
 312                                 if (n->prio == 2)
 313                                         annotated_cnt++;
 314                         }
 315                         else {
 316                                 gave_up_on = c;
 317                                 break;
 318                         }
 319                 }
 320                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 321                         struct possible_tag *t = &all_matches[cur_match];
 322                         if (!(c->object.flags & t->flag_within))
 323                                 t->depth++;
 324                 }
 325                 if (annotated_cnt && !list) {
 326                         if (debug)
 327                                 fprintf(stderr, _("finished search at %s\n"),
 328                                         sha1_to_hex(c->object.sha1));
 329                         break;
 330                 }
 331                 while (parents) {
 332                         struct commit *p = parents->item;
 333                         parse_commit(p);
 334                         if (!(p->object.flags & SEEN))
 335                                 commit_list_insert_by_date(p, &list);
 336                         p->object.flags |= c->object.flags;
 337                         parents = parents->next;
 338
 339                         if (first_parent)
 340                                 break;
 341                 }
 342         }
 343
 344         if (!match_cnt) {
 345                 const unsigned char *sha1 = cmit->object.sha1;
 346                 if (always) {
 347                         printf("%s", find_unique_abbrev(sha1, abbrev));
 348                         if (dirty)
 349                                 printf("%s", dirty);
 350                         printf("\n");
 351                         return;
 352                 }
 353                 if (unannotated_cnt)
 354                         die(_("No annotated tags can describe '%s'.\n"
 355                             "However, there were unannotated tags: try --tags."),
 356                             sha1_to_hex(sha1));
 357                 else
 358                         die(_("No tags can describe '%s'.\n"
 359                             "Try --always, or create some tags."),
 360                             sha1_to_hex(sha1));
 361         }
 362
 363         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 364
 365         if (gave_up_on) {
 366                 commit_list_insert_by_date(gave_up_on, &list);
 367                 seen_commits--;
 368         }
 369         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 370         free_commit_list(list);
 371
 372         if (debug) {
 373                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 374                         struct possible_tag *t = &all_matches[cur_match];
 375                         fprintf(stderr, " %-11s %8d %s\n",
 376                                 prio_names[t->name->prio],
 377                                 t->depth, t->name->path);
 378                 }
 379                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 380                 if (gave_up_on) {
 381                         fprintf(stderr,
 382                                 _("more than %i tags found; listed %i most recent\n"
 383                                 "gave up search at %s\n"),
 384                                 max_candidates, max_candidates,
 385                                 sha1_to_hex(gave_up_on->object.sha1));
 386                 }
 387         }
 388
 389         display_name(all_matches[0].name);
 390         if (abbrev)
 391                 show_suffix(all_matches[0].depth, cmit->object.sha1);
 392         if (dirty)
 393                 printf("%s", dirty);
 394         printf("\n");
 395
 396         if (!last_one)
 397                 clear_commit_marks(cmit, -1);
 398 }
 399
 400 int cmd_describe(int argc, const char **argv, const char *prefix)
 401 {
 402         int contains = 0;
 403         struct option options[] = {
 404                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 405                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
 406                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
 407                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
 408                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
 409                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
 410                 OPT__ABBREV(&abbrev),
 411                 OPT_SET_INT(0, "exact-match", &max_candidates,
 412                             N_("only output exact matches"), 0),
 413                 OPT_INTEGER(0, "candidates", &max_candidates,
 414                             N_("consider <n> most recent tags (default: 10)")),
 415                 OPT_STRING(0, "match",       &pattern, N_("pattern"),
 416                            N_("only consider tags matching <pattern>")),
 417                 OPT_BOOL(0, "always",        &always,
 418                         N_("show abbreviated commit object as fallback")),
 419                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 420                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 421                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 422                 OPT_END(),
 423         };
 424
 425         git_config(git_default_config, NULL);
 426         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 427         if (abbrev < 0)
 428                 abbrev = DEFAULT_ABBREV;
 429
 430         if (max_candidates < 0)
 431                 max_candidates = 0;
 432         else if (max_candidates > MAX_TAGS)
 433                 max_candidates = MAX_TAGS;
 434
 435         save_commit_buffer = 0;
 436
 437         if (longformat && abbrev == 0)
 438                 die(_("--long is incompatible with --abbrev=0"));
 439
 440         if (contains) {
 441                 struct argv_array args;
 442
 443                 argv_array_init(&args);
 444                 argv_array_pushl(&args, "name-rev",
 445                                  "--peel-tag", "--name-only", "--no-undefined",
 446                                  NULL);
 447                 if (always)
 448                         argv_array_push(&args, "--always");
 449                 if (!all) {
 450                         argv_array_push(&args, "--tags");
 451                         if (pattern)
 452                                 argv_array_pushf(&args, "--refs=refs/tags/%s", pattern);
 453                 }
 454                 while (*argv) {
 455                         argv_array_push(&args, *argv);
 456                         argv++;
 457                 }
 458                 return cmd_name_rev(args.argc, args.argv, prefix);
 459         }
 460
 461         hashmap_init(&names, (hashmap_cmp_fn) commit_name_cmp, 0);
 462         for_each_rawref(get_name, NULL);
 463         if (!names.size && !always)
 464                 die(_("No names found, cannot describe anything."));
 465
 466         if (argc == 0) {
 467                 if (dirty) {
 468                         static struct lock_file index_lock;
 469                         int fd;
 470
 471                         read_cache_preload(NULL);
 472                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 473                                       NULL, NULL, NULL);
 474                         fd = hold_locked_index(&index_lock, 0);
 475                         if (0 <= fd)
 476                                 update_index_if_able(&the_index, &index_lock);
 477
 478                         if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
 479                                             diff_index_args, prefix))
 480                                 dirty = NULL;
 481                 }
 482                 describe("HEAD", 1);
 483         } else if (dirty) {
 484                 die(_("--dirty is incompatible with commit-ishes"));
 485         } else {
 486                 while (argc-- > 0)
 487                         describe(*argv++, argc == 0);
 488         }
 489         return 0;
 490 }