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 first_parent;
  25 static int abbrev = -1; /* unspecified */
  26 static int max_candidates = 10;
  27 static struct hash_table names;
  28 static int have_util;
  29 static const char *pattern;
  30 static int always;
  31 static const char *dirty;
  32
  33 /* diff-index command arguments to check if working tree is dirty. */
  34 static const char *diff_index_args[] = {
  35         "diff-index", "--quiet", "HEAD", "--", NULL
  36 };
  37
  38
  39 struct commit_name {
  40         struct commit_name *next;
  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 static const char *prio_names[] = {
  49         "head", "lightweight", "annotated",
  50 };
  51
  52 static inline unsigned int hash_sha1(const unsigned char *sha1)
  53 {
  54         unsigned int hash;
  55         memcpy(&hash, sha1, sizeof(hash));
  56         return hash;
  57 }
  58
  59 static inline struct commit_name *find_commit_name(const unsigned char *peeled)
  60 {
  61         struct commit_name *n = lookup_hash(hash_sha1(peeled), &names);
  62         while (n && !!hashcmp(peeled, n->peeled))
  63                 n = n->next;
  64         return n;
  65 }
  66
  67 static int set_util(void *chain, void *data)
  68 {
  69         struct commit_name *n;
  70         for (n = chain; n; n = n->next) {
  71                 struct commit *c = lookup_commit_reference_gently(n->peeled, 1);
  72                 if (c)
  73                         c->util = n;
  74         }
  75         return 0;
  76 }
  77
  78 static int replace_name(struct commit_name *e,
  79                                int prio,
  80                                const unsigned char *sha1,
  81                                struct tag **tag)
  82 {
  83         if (!e || e->prio < prio)
  84                 return 1;
  85
  86         if (e->prio == 2 && prio == 2) {
  87                 /* Multiple annotated tags point to the same commit.
  88                  * Select one to keep based upon their tagger date.
  89                  */
  90                 struct tag *t;
  91
  92                 if (!e->tag) {
  93                         t = lookup_tag(e->sha1);
  94                         if (!t || parse_tag(t))
  95                                 return 1;
  96                         e->tag = t;
  97                 }
  98
  99                 t = lookup_tag(sha1);
 100                 if (!t || parse_tag(t))
 101                         return 0;
 102                 *tag = t;
 103
 104                 if (e->tag->date < t->date)
 105                         return 1;
 106         }
 107
 108         return 0;
 109 }
 110
 111 static void add_to_known_names(const char *path,
 112                                const unsigned char *peeled,
 113                                int prio,
 114                                const unsigned char *sha1)
 115 {
 116         struct commit_name *e = find_commit_name(peeled);
 117         struct tag *tag = NULL;
 118         if (replace_name(e, prio, sha1, &tag)) {
 119                 if (!e) {
 120                         void **pos;
 121                         e = xmalloc(sizeof(struct commit_name));
 122                         hashcpy(e->peeled, peeled);
 123                         pos = insert_hash(hash_sha1(peeled), e, &names);
 124                         if (pos) {
 125                                 e->next = *pos;
 126                                 *pos = e;
 127                         } else {
 128                                 e->next = NULL;
 129                         }
 130                         e->path = NULL;
 131                 }
 132                 e->tag = tag;
 133                 e->prio = prio;
 134                 e->name_checked = 0;
 135                 hashcpy(e->sha1, sha1);
 136                 free(e->path);
 137                 e->path = xstrdup(path);
 138         }
 139 }
 140
 141 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 142 {
 143         int is_tag = !prefixcmp(path, "refs/tags/");
 144         unsigned char peeled[20];
 145         int is_annotated, prio;
 146
 147         /* Reject anything outside refs/tags/ unless --all */
 148         if (!all && !is_tag)
 149                 return 0;
 150
 151         /* Accept only tags that match the pattern, if given */
 152         if (pattern && (!is_tag || fnmatch(pattern, path + 10, 0)))
 153                 return 0;
 154
 155         /* Is it annotated? */
 156         if (!peel_ref(path, peeled)) {
 157                 is_annotated = !!hashcmp(sha1, peeled);
 158         } else {
 159                 hashcpy(peeled, sha1);
 160                 is_annotated = 0;
 161         }
 162
 163         /*
 164          * By default, we only use annotated tags, but with --tags
 165          * we fall back to lightweight ones (even without --tags,
 166          * we still remember lightweight ones, only to give hints
 167          * in an error message).  --all allows any refs to be used.
 168          */
 169         if (is_annotated)
 170                 prio = 2;
 171         else if (is_tag)
 172                 prio = 1;
 173         else
 174                 prio = 0;
 175
 176         add_to_known_names(all ? path + 5 : path + 10, peeled, prio, sha1);
 177         return 0;
 178 }
 179
 180 struct possible_tag {
 181         struct commit_name *name;
 182         int depth;
 183         int found_order;
 184         unsigned flag_within;
 185 };
 186
 187 static int compare_pt(const void *a_, const void *b_)
 188 {
 189         struct possible_tag *a = (struct possible_tag *)a_;
 190         struct possible_tag *b = (struct possible_tag *)b_;
 191         if (a->depth != b->depth)
 192                 return a->depth - b->depth;
 193         if (a->found_order != b->found_order)
 194                 return a->found_order - b->found_order;
 195         return 0;
 196 }
 197
 198 static unsigned long finish_depth_computation(
 199         struct commit_list **list,
 200         struct possible_tag *best)
 201 {
 202         unsigned long seen_commits = 0;
 203         while (*list) {
 204                 struct commit *c = pop_commit(list);
 205                 struct commit_list *parents = c->parents;
 206                 seen_commits++;
 207                 if (c->object.flags & best->flag_within) {
 208                         struct commit_list *a = *list;
 209                         while (a) {
 210                                 struct commit *i = a->item;
 211                                 if (!(i->object.flags & best->flag_within))
 212                                         break;
 213                                 a = a->next;
 214                         }
 215                         if (!a)
 216                                 break;
 217                 } else
 218                         best->depth++;
 219                 while (parents) {
 220                         struct commit *p = parents->item;
 221                         parse_commit(p);
 222                         if (!(p->object.flags & SEEN))
 223                                 commit_list_insert_by_date(p, list);
 224                         p->object.flags |= c->object.flags;
 225                         parents = parents->next;
 226                 }
 227         }
 228         return seen_commits;
 229 }
 230
 231 static void display_name(struct commit_name *n)
 232 {
 233         if (n->prio == 2 && !n->tag) {
 234                 n->tag = lookup_tag(n->sha1);
 235                 if (!n->tag || parse_tag(n->tag))
 236                         die(_("annotated tag %s not available"), n->path);
 237         }
 238         if (n->tag && !n->name_checked) {
 239                 if (!n->tag->tag)
 240                         die(_("annotated tag %s has no embedded name"), n->path);
 241                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 242                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 243                 n->name_checked = 1;
 244         }
 245
 246         if (n->tag)
 247                 printf("%s", n->tag->tag);
 248         else
 249                 printf("%s", n->path);
 250 }
 251
 252 static void show_suffix(int depth, const unsigned char *sha1)
 253 {
 254         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 255 }
 256
 257 static void describe(const char *arg, int last_one)
 258 {
 259         unsigned char sha1[20];
 260         struct commit *cmit, *gave_up_on = NULL;
 261         struct commit_list *list;
 262         struct commit_name *n;
 263         struct possible_tag all_matches[MAX_TAGS];
 264         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 265         unsigned long seen_commits = 0;
 266         unsigned int unannotated_cnt = 0;
 267
 268         if (get_sha1(arg, sha1))
 269                 die(_("Not a valid object name %s"), arg);
 270         cmit = lookup_commit_reference(sha1);
 271         if (!cmit)
 272                 die(_("%s is not a valid '%s' object"), arg, commit_type);
 273
 274         n = find_commit_name(cmit->object.sha1);
 275         if (n && (tags || all || n->prio == 2)) {
 276                 /*
 277                  * Exact match to an existing ref.
 278                  */
 279                 display_name(n);
 280                 if (longformat)
 281                         show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 282                 if (dirty)
 283                         printf("%s", dirty);
 284                 printf("\n");
 285                 return;
 286         }
 287
 288         if (!max_candidates)
 289                 die(_("no tag exactly matches '%s'"), sha1_to_hex(cmit->object.sha1));
 290         if (debug)
 291                 fprintf(stderr, _("searching to describe %s\n"), arg);
 292
 293         if (!have_util) {
 294                 for_each_hash(&names, set_util, NULL);
 295                 have_util = 1;
 296         }
 297
 298         list = NULL;
 299         cmit->object.flags = SEEN;
 300         commit_list_insert(cmit, &list);
 301         while (list) {
 302                 struct commit *c = pop_commit(&list);
 303                 struct commit_list *parents = c->parents;
 304                 seen_commits++;
 305                 n = c->util;
 306                 if (n) {
 307                         if (!tags && !all && n->prio < 2) {
 308                                 unannotated_cnt++;
 309                         } else if (match_cnt < max_candidates) {
 310                                 struct possible_tag *t = &all_matches[match_cnt++];
 311                                 t->name = n;
 312                                 t->depth = seen_commits - 1;
 313                                 t->flag_within = 1u << match_cnt;
 314                                 t->found_order = match_cnt;
 315                                 c->object.flags |= t->flag_within;
 316                                 if (n->prio == 2)
 317                                         annotated_cnt++;
 318                         }
 319                         else {
 320                                 gave_up_on = c;
 321                                 break;
 322                         }
 323                 }
 324                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 325                         struct possible_tag *t = &all_matches[cur_match];
 326                         if (!(c->object.flags & t->flag_within))
 327                                 t->depth++;
 328                 }
 329                 if (annotated_cnt && !list) {
 330                         if (debug)
 331                                 fprintf(stderr, _("finished search at %s\n"),
 332                                         sha1_to_hex(c->object.sha1));
 333                         break;
 334                 }
 335                 while (parents) {
 336                         struct commit *p = parents->item;
 337                         parse_commit(p);
 338                         if (!(p->object.flags & SEEN))
 339                                 commit_list_insert_by_date(p, &list);
 340                         p->object.flags |= c->object.flags;
 341                         parents = parents->next;
 342
 343                         if (first_parent)
 344                                 break;
 345                 }
 346         }
 347
 348         if (!match_cnt) {
 349                 const unsigned char *sha1 = cmit->object.sha1;
 350                 if (always) {
 351                         printf("%s", find_unique_abbrev(sha1, abbrev));
 352                         if (dirty)
 353                                 printf("%s", dirty);
 354                         printf("\n");
 355                         return;
 356                 }
 357                 if (unannotated_cnt)
 358                         die(_("No annotated tags can describe '%s'.\n"
 359                             "However, there were unannotated tags: try --tags."),
 360                             sha1_to_hex(sha1));
 361                 else
 362                         die(_("No tags can describe '%s'.\n"
 363                             "Try --always, or create some tags."),
 364                             sha1_to_hex(sha1));
 365         }
 366
 367         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 368
 369         if (gave_up_on) {
 370                 commit_list_insert_by_date(gave_up_on, &list);
 371                 seen_commits--;
 372         }
 373         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 374         free_commit_list(list);
 375
 376         if (debug) {
 377                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 378                         struct possible_tag *t = &all_matches[cur_match];
 379                         fprintf(stderr, " %-11s %8d %s\n",
 380                                 prio_names[t->name->prio],
 381                                 t->depth, t->name->path);
 382                 }
 383                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 384                 if (gave_up_on) {
 385                         fprintf(stderr,
 386                                 _("more than %i tags found; listed %i most recent\n"
 387                                 "gave up search at %s\n"),
 388                                 max_candidates, max_candidates,
 389                                 sha1_to_hex(gave_up_on->object.sha1));
 390                 }
 391         }
 392
 393         display_name(all_matches[0].name);
 394         if (abbrev)
 395                 show_suffix(all_matches[0].depth, cmit->object.sha1);
 396         if (dirty)
 397                 printf("%s", dirty);
 398         printf("\n");
 399
 400         if (!last_one)
 401                 clear_commit_marks(cmit, -1);
 402 }
 403
 404 int cmd_describe(int argc, const char **argv, const char *prefix)
 405 {
 406         int contains = 0;
 407         struct option options[] = {
 408                 OPT_BOOLEAN(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 409                 OPT_BOOLEAN(0, "debug",      &debug, N_("debug search strategy on stderr")),
 410                 OPT_BOOLEAN(0, "all",        &all, N_("use any ref")),
 411                 OPT_BOOLEAN(0, "tags",       &tags, N_("use any tag, even unannotated")),
 412                 OPT_BOOLEAN(0, "long",       &longformat, N_("always use long format")),
 413                 OPT_BOOLEAN(0, "first-parent", &first_parent, N_("only follow first parent")),
 414                 OPT__ABBREV(&abbrev),
 415                 OPT_SET_INT(0, "exact-match", &max_candidates,
 416                             N_("only output exact matches"), 0),
 417                 OPT_INTEGER(0, "candidates", &max_candidates,
 418                             N_("consider <n> most recent tags (default: 10)")),
 419                 OPT_STRING(0, "match",       &pattern, N_("pattern"),
 420                            N_("only consider tags matching <pattern>")),
 421                 OPT_BOOLEAN(0, "always",     &always,
 422                            N_("show abbreviated commit object as fallback")),
 423                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 424                            N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 425                  PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 426                 OPT_END(),
 427         };
 428
 429         git_config(git_default_config, NULL);
 430         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 431         if (abbrev < 0)
 432                 abbrev = DEFAULT_ABBREV;
 433
 434         if (max_candidates < 0)
 435                 max_candidates = 0;
 436         else if (max_candidates > MAX_TAGS)
 437                 max_candidates = MAX_TAGS;
 438
 439         save_commit_buffer = 0;
 440
 441         if (longformat && abbrev == 0)
 442                 die(_("--long is incompatible with --abbrev=0"));
 443
 444         if (contains) {
 445                 const char **args = xmalloc((7 + argc) * sizeof(char *));
 446                 int i = 0;
 447                 args[i++] = "name-rev";
 448                 args[i++] = "--name-only";
 449                 args[i++] = "--no-undefined";
 450                 if (always)
 451                         args[i++] = "--always";
 452                 if (!all) {
 453                         args[i++] = "--tags";
 454                         if (pattern) {
 455                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 456                                 sprintf(s, "--refs=refs/tags/%s", pattern);
 457                                 args[i++] = s;
 458                         }
 459                 }
 460                 memcpy(args + i, argv, argc * sizeof(char *));
 461                 args[i + argc] = NULL;
 462                 return cmd_name_rev(i + argc, args, prefix);
 463         }
 464
 465         init_hash(&names);
 466         for_each_rawref(get_name, NULL);
 467         if (!names.nr && !always)
 468                 die(_("No names found, cannot describe anything."));
 469
 470         if (argc == 0) {
 471                 if (dirty) {
 472                         static struct lock_file index_lock;
 473                         int fd;
 474
 475                         read_cache_preload(NULL);
 476                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 477                                       NULL, NULL, NULL);
 478                         fd = hold_locked_index(&index_lock, 0);
 479                         if (0 <= fd)
 480                                 update_index_if_able(&the_index, &index_lock);
 481
 482                         if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
 483                                             diff_index_args, prefix))
 484                                 dirty = NULL;
 485                 }
 486                 describe("HEAD", 1);
 487         } else if (dirty) {
 488                 die(_("--dirty is incompatible with committishes"));
 489         } else {
 490                 while (argc-- > 0) {
 491                         describe(*argv++, argc == 0);
 492                 }
 493         }
 494         return 0;
 495 }