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 "hash.h"
  10
  11 #define SEEN            (1u<<0)
  12 #define MAX_TAGS        (FLAG_BITS - 1)
  13
  14 static const char * const describe_usage[] = {
  15         N_("git describe [options] <committish>*"),
  16         N_("git describe [options] --dirty"),
  17         NULL
  18 };
  19
  20 static int debug;       /* Display lots of verbose info */
  21 static int all; /* Any valid ref can be used */
  22 static int tags;        /* Allow lightweight tags */
  23 static int longformat;
  24 static int abbrev = -1; /* unspecified */
  25 static int max_candidates = 10;
  26 static struct hash_table names;
  27 static int have_util;
  28 static const char *pattern;
  29 static int always;
  30 static const char *dirty;
  31
  32 /* diff-index command arguments to check if working tree is dirty. */
  33 static const char *diff_index_args[] = {
  34         "diff-index", "--quiet", "HEAD", "--", NULL
  35 };
  36
  37
  38 struct commit_name {
  39         struct commit_name *next;
  40         unsigned char peeled[20];
  41         struct tag *tag;
  42         unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  43         unsigned name_checked:1;
  44         unsigned char sha1[20];
  45         char *path;
  46 };
  47 static const char *prio_names[] = {
  48         "head", "lightweight", "annotated",
  49 };
  50
  51 static inline unsigned int hash_sha1(const unsigned char *sha1)
  52 {
  53         unsigned int hash;
  54         memcpy(&hash, sha1, sizeof(hash));
  55         return hash;
  56 }
  57
  58 static inline struct commit_name *find_commit_name(const unsigned char *peeled)
  59 {
  60         struct commit_name *n = lookup_hash(hash_sha1(peeled), &names);
  61         while (n && !!hashcmp(peeled, n->peeled))
  62                 n = n->next;
  63         return n;
  64 }
  65
  66 static int set_util(void *chain, void *data)
  67 {
  68         struct commit_name *n;
  69         for (n = chain; n; n = n->next) {
  70                 struct commit *c = lookup_commit_reference_gently(n->peeled, 1);
  71                 if (c)
  72                         c->util = n;
  73         }
  74         return 0;
  75 }
  76
  77 static int replace_name(struct commit_name *e,
  78                                int prio,
  79                                const unsigned char *sha1,
  80                                struct tag **tag)
  81 {
  82         if (!e || e->prio < prio)
  83                 return 1;
  84
  85         if (e->prio == 2 && prio == 2) {
  86                 /* Multiple annotated tags point to the same commit.
  87                  * Select one to keep based upon their tagger date.
  88                  */
  89                 struct tag *t;
  90
  91                 if (!e->tag) {
  92                         t = lookup_tag(e->sha1);
  93                         if (!t || parse_tag(t))
  94                                 return 1;
  95                         e->tag = t;
  96                 }
  97
  98                 t = lookup_tag(sha1);
  99                 if (!t || parse_tag(t))
 100                         return 0;
 101                 *tag = t;
 102
 103                 if (e->tag->date < t->date)
 104                         return 1;
 105         }
 106
 107         return 0;
 108 }
 109
 110 static void add_to_known_names(const char *path,
 111                                const unsigned char *peeled,
 112                                int prio,
 113                                const unsigned char *sha1)
 114 {
 115         struct commit_name *e = find_commit_name(peeled);
 116         struct tag *tag = NULL;
 117         if (replace_name(e, prio, sha1, &tag)) {
 118                 if (!e) {
 119                         void **pos;
 120                         e = xmalloc(sizeof(struct commit_name));
 121                         hashcpy(e->peeled, peeled);
 122                         pos = insert_hash(hash_sha1(peeled), e, &names);
 123                         if (pos) {
 124                                 e->next = *pos;
 125                                 *pos = e;
 126                         } else {
 127                                 e->next = NULL;
 128                         }
 129                         e->path = NULL;
 130                 }
 131                 e->tag = tag;
 132                 e->prio = prio;
 133                 e->name_checked = 0;
 134                 hashcpy(e->sha1, sha1);
 135                 free(e->path);
 136                 e->path = xstrdup(path);
 137         }
 138 }
 139
 140 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 141 {
 142         int is_tag = !prefixcmp(path, "refs/tags/");
 143         unsigned char peeled[20];
 144         int is_annotated, prio;
 145
 146         /* Reject anything outside refs/tags/ unless --all */
 147         if (!all && !is_tag)
 148                 return 0;
 149
 150         /* Accept only tags that match the pattern, if given */
 151         if (pattern && (!is_tag || fnmatch(pattern, path + 10, 0)))
 152                 return 0;
 153
 154         /* Is it annotated? */
 155         if (!peel_ref(path, peeled)) {
 156                 is_annotated = !!hashcmp(sha1, peeled);
 157         } else {
 158                 hashcpy(peeled, sha1);
 159                 is_annotated = 0;
 160         }
 161
 162         /*
 163          * By default, we only use annotated tags, but with --tags
 164          * we fall back to lightweight ones (even without --tags,
 165          * we still remember lightweight ones, only to give hints
 166          * in an error message).  --all allows any refs to be used.
 167          */
 168         if (is_annotated)
 169                 prio = 2;
 170         else if (is_tag)
 171                 prio = 1;
 172         else
 173                 prio = 0;
 174
 175         add_to_known_names(all ? path + 5 : path + 10, peeled, prio, sha1);
 176         return 0;
 177 }
 178
 179 struct possible_tag {
 180         struct commit_name *name;
 181         int depth;
 182         int found_order;
 183         unsigned flag_within;
 184 };
 185
 186 static int compare_pt(const void *a_, const void *b_)
 187 {
 188         struct possible_tag *a = (struct possible_tag *)a_;
 189         struct possible_tag *b = (struct possible_tag *)b_;
 190         if (a->depth != b->depth)
 191                 return a->depth - b->depth;
 192         if (a->found_order != b->found_order)
 193                 return a->found_order - b->found_order;
 194         return 0;
 195 }
 196
 197 static unsigned long finish_depth_computation(
 198         struct commit_list **list,
 199         struct possible_tag *best)
 200 {
 201         unsigned long seen_commits = 0;
 202         while (*list) {
 203                 struct commit *c = pop_commit(list);
 204                 struct commit_list *parents = c->parents;
 205                 seen_commits++;
 206                 if (c->object.flags & best->flag_within) {
 207                         struct commit_list *a = *list;
 208                         while (a) {
 209                                 struct commit *i = a->item;
 210                                 if (!(i->object.flags & best->flag_within))
 211                                         break;
 212                                 a = a->next;
 213                         }
 214                         if (!a)
 215                                 break;
 216                 } else
 217                         best->depth++;
 218                 while (parents) {
 219                         struct commit *p = parents->item;
 220                         parse_commit(p);
 221                         if (!(p->object.flags & SEEN))
 222                                 commit_list_insert_by_date(p, list);
 223                         p->object.flags |= c->object.flags;
 224                         parents = parents->next;
 225                 }
 226         }
 227         return seen_commits;
 228 }
 229
 230 static void display_name(struct commit_name *n)
 231 {
 232         if (n->prio == 2 && !n->tag) {
 233                 n->tag = lookup_tag(n->sha1);
 234                 if (!n->tag || parse_tag(n->tag))
 235                         die(_("annotated tag %s not available"), n->path);
 236         }
 237         if (n->tag && !n->name_checked) {
 238                 if (!n->tag->tag)
 239                         die(_("annotated tag %s has no embedded name"), n->path);
 240                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 241                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 242                 n->name_checked = 1;
 243         }
 244
 245         if (n->tag)
 246                 printf("%s", n->tag->tag);
 247         else
 248                 printf("%s", n->path);
 249 }
 250
 251 static void show_suffix(int depth, const unsigned char *sha1)
 252 {
 253         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 254 }
 255
 256 static void describe(const char *arg, int last_one)
 257 {
 258         unsigned char sha1[20];
 259         struct commit *cmit, *gave_up_on = NULL;
 260         struct commit_list *list;
 261         struct commit_name *n;
 262         struct possible_tag all_matches[MAX_TAGS];
 263         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 264         unsigned long seen_commits = 0;
 265         unsigned int unannotated_cnt = 0;
 266
 267         if (get_sha1(arg, sha1))
 268                 die(_("Not a valid object name %s"), arg);
 269         cmit = lookup_commit_reference(sha1);
 270         if (!cmit)
 271                 die(_("%s is not a valid '%s' object"), arg, commit_type);
 272
 273         n = find_commit_name(cmit->object.sha1);
 274         if (n && (tags || all || n->prio == 2)) {
 275                 /*
 276                  * Exact match to an existing ref.
 277                  */
 278                 display_name(n);
 279                 if (longformat)
 280                         show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 281                 if (dirty)
 282                         printf("%s", dirty);
 283                 printf("\n");
 284                 return;
 285         }
 286
 287         if (!max_candidates)
 288                 die(_("no tag exactly matches '%s'"), sha1_to_hex(cmit->object.sha1));
 289         if (debug)
 290                 fprintf(stderr, _("searching to describe %s\n"), arg);
 291
 292         if (!have_util) {
 293                 for_each_hash(&names, set_util, NULL);
 294                 have_util = 1;
 295         }
 296
 297         list = NULL;
 298         cmit->object.flags = SEEN;
 299         commit_list_insert(cmit, &list);
 300         while (list) {
 301                 struct commit *c = pop_commit(&list);
 302                 struct commit_list *parents = c->parents;
 303                 seen_commits++;
 304                 n = c->util;
 305                 if (n) {
 306                         if (!tags && !all && n->prio < 2) {
 307                                 unannotated_cnt++;
 308                         } else if (match_cnt < max_candidates) {
 309                                 struct possible_tag *t = &all_matches[match_cnt++];
 310                                 t->name = n;
 311                                 t->depth = seen_commits - 1;
 312                                 t->flag_within = 1u << match_cnt;
 313                                 t->found_order = match_cnt;
 314                                 c->object.flags |= t->flag_within;
 315                                 if (n->prio == 2)
 316                                         annotated_cnt++;
 317                         }
 318                         else {
 319                                 gave_up_on = c;
 320                                 break;
 321                         }
 322                 }
 323                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 324                         struct possible_tag *t = &all_matches[cur_match];
 325                         if (!(c->object.flags & t->flag_within))
 326                                 t->depth++;
 327                 }
 328                 if (annotated_cnt && !list) {
 329                         if (debug)
 330                                 fprintf(stderr, _("finished search at %s\n"),
 331                                         sha1_to_hex(c->object.sha1));
 332                         break;
 333                 }
 334                 while (parents) {
 335                         struct commit *p = parents->item;
 336                         parse_commit(p);
 337                         if (!(p->object.flags & SEEN))
 338                                 commit_list_insert_by_date(p, &list);
 339                         p->object.flags |= c->object.flags;
 340                         parents = parents->next;
 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_BOOLEAN(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 405                 OPT_BOOLEAN(0, "debug",      &debug, N_("debug search strategy on stderr")),
 406                 OPT_BOOLEAN(0, "all",        &all, N_("use any ref")),
 407                 OPT_BOOLEAN(0, "tags",       &tags, N_("use any tag, even unannotated")),
 408                 OPT_BOOLEAN(0, "long",       &longformat, N_("always use long format")),
 409                 OPT__ABBREV(&abbrev),
 410                 OPT_SET_INT(0, "exact-match", &max_candidates,
 411                             N_("only output exact matches"), 0),
 412                 OPT_INTEGER(0, "candidates", &max_candidates,
 413                             N_("consider <n> most recent tags (default: 10)")),
 414                 OPT_STRING(0, "match",       &pattern, N_("pattern"),
 415                            N_("only consider tags matching <pattern>")),
 416                 OPT_BOOLEAN(0, "always",     &always,
 417                            N_("show abbreviated commit object as fallback")),
 418                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 419                            N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 420                  PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 421                 OPT_END(),
 422         };
 423
 424         git_config(git_default_config, NULL);
 425         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 426         if (abbrev < 0)
 427                 abbrev = DEFAULT_ABBREV;
 428
 429         if (max_candidates < 0)
 430                 max_candidates = 0;
 431         else if (max_candidates > MAX_TAGS)
 432                 max_candidates = MAX_TAGS;
 433
 434         save_commit_buffer = 0;
 435
 436         if (longformat && abbrev == 0)
 437                 die(_("--long is incompatible with --abbrev=0"));
 438
 439         if (contains) {
 440                 const char **args = xmalloc((7 + argc) * sizeof(char *));
 441                 int i = 0;
 442                 args[i++] = "name-rev";
 443                 args[i++] = "--name-only";
 444                 args[i++] = "--no-undefined";
 445                 if (always)
 446                         args[i++] = "--always";
 447                 if (!all) {
 448                         args[i++] = "--tags";
 449                         if (pattern) {
 450                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 451                                 sprintf(s, "--refs=refs/tags/%s", pattern);
 452                                 args[i++] = s;
 453                         }
 454                 }
 455                 memcpy(args + i, argv, argc * sizeof(char *));
 456                 args[i + argc] = NULL;
 457                 return cmd_name_rev(i + argc, args, prefix);
 458         }
 459
 460         init_hash(&names);
 461         for_each_rawref(get_name, NULL);
 462         if (!names.nr && !always)
 463                 die(_("No names found, cannot describe anything."));
 464
 465         if (argc == 0) {
 466                 if (dirty) {
 467                         static struct lock_file index_lock;
 468                         int fd;
 469
 470                         read_cache_preload(NULL);
 471                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 472                                       NULL, NULL, NULL);
 473                         fd = hold_locked_index(&index_lock, 0);
 474                         if (0 <= fd)
 475                                 update_index_if_able(&the_index, &index_lock);
 476
 477                         if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
 478                                             diff_index_args, prefix))
 479                                 dirty = NULL;
 480                 }
 481                 describe("HEAD", 1);
 482         } else if (dirty) {
 483                 die(_("--dirty is incompatible with committishes"));
 484         } else {
 485                 while (argc-- > 0) {
 486                         describe(*argv++, argc == 0);
 487                 }
 488         }
 489         return 0;
 490 }