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 #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] <committish>*"),
  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 hash_table 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
  40 struct commit_name {
  41         struct commit_name *next;
  42         unsigned char peeled[20];
  43         struct tag *tag;
  44         unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  45         unsigned name_checked:1;
  46         unsigned char sha1[20];
  47         char *path;
  48 };
  49 static const char *prio_names[] = {
  50         "head", "lightweight", "annotated",
  51 };
  52
  53 static inline unsigned int hash_sha1(const unsigned char *sha1)
  54 {
  55         unsigned int hash;
  56         memcpy(&hash, sha1, sizeof(hash));
  57         return hash;
  58 }
  59
  60 static inline struct commit_name *find_commit_name(const unsigned char *peeled)
  61 {
  62         struct commit_name *n = lookup_hash(hash_sha1(peeled), &names);
  63         while (n && !!hashcmp(peeled, n->peeled))
  64                 n = n->next;
  65         return n;
  66 }
  67
  68 static int set_util(void *chain, void *data)
  69 {
  70         struct commit_name *n;
  71         for (n = chain; n; n = n->next) {
  72                 struct commit *c = lookup_commit_reference_gently(n->peeled, 1);
  73                 if (c)
  74                         c->util = n;
  75         }
  76         return 0;
  77 }
  78
  79 static int replace_name(struct commit_name *e,
  80                                int prio,
  81                                const unsigned char *sha1,
  82                                struct tag **tag)
  83 {
  84         if (!e || e->prio < prio)
  85                 return 1;
  86
  87         if (e->prio == 2 && prio == 2) {
  88                 /* Multiple annotated tags point to the same commit.
  89                  * Select one to keep based upon their tagger date.
  90                  */
  91                 struct tag *t;
  92
  93                 if (!e->tag) {
  94                         t = lookup_tag(e->sha1);
  95                         if (!t || parse_tag(t))
  96                                 return 1;
  97                         e->tag = t;
  98                 }
  99
 100                 t = lookup_tag(sha1);
 101                 if (!t || parse_tag(t))
 102                         return 0;
 103                 *tag = t;
 104
 105                 if (e->tag->date < t->date)
 106                         return 1;
 107         }
 108
 109         return 0;
 110 }
 111
 112 static void add_to_known_names(const char *path,
 113                                const unsigned char *peeled,
 114                                int prio,
 115                                const unsigned char *sha1)
 116 {
 117         struct commit_name *e = find_commit_name(peeled);
 118         struct tag *tag = NULL;
 119         if (replace_name(e, prio, sha1, &tag)) {
 120                 if (!e) {
 121                         void **pos;
 122                         e = xmalloc(sizeof(struct commit_name));
 123                         hashcpy(e->peeled, peeled);
 124                         pos = insert_hash(hash_sha1(peeled), e, &names);
 125                         if (pos) {
 126                                 e->next = *pos;
 127                                 *pos = e;
 128                         } else {
 129                                 e->next = NULL;
 130                         }
 131                         e->path = NULL;
 132                 }
 133                 e->tag = tag;
 134                 e->prio = prio;
 135                 e->name_checked = 0;
 136                 hashcpy(e->sha1, sha1);
 137                 free(e->path);
 138                 e->path = xstrdup(path);
 139         }
 140 }
 141
 142 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 143 {
 144         int is_tag = !prefixcmp(path, "refs/tags/");
 145         unsigned char peeled[20];
 146         int is_annotated, prio;
 147
 148         /* Reject anything outside refs/tags/ unless --all */
 149         if (!all && !is_tag)
 150                 return 0;
 151
 152         /* Accept only tags that match the pattern, if given */
 153         if (pattern && (!is_tag || fnmatch(pattern, path + 10, 0)))
 154                 return 0;
 155
 156         /* Is it annotated? */
 157         if (!peel_ref(path, peeled)) {
 158                 is_annotated = !!hashcmp(sha1, peeled);
 159         } else {
 160                 hashcpy(peeled, sha1);
 161                 is_annotated = 0;
 162         }
 163
 164         /*
 165          * By default, we only use annotated tags, but with --tags
 166          * we fall back to lightweight ones (even without --tags,
 167          * we still remember lightweight ones, only to give hints
 168          * in an error message).  --all allows any refs to be used.
 169          */
 170         if (is_annotated)
 171                 prio = 2;
 172         else if (is_tag)
 173                 prio = 1;
 174         else
 175                 prio = 0;
 176
 177         add_to_known_names(all ? path + 5 : path + 10, peeled, prio, sha1);
 178         return 0;
 179 }
 180
 181 struct possible_tag {
 182         struct commit_name *name;
 183         int depth;
 184         int found_order;
 185         unsigned flag_within;
 186 };
 187
 188 static int compare_pt(const void *a_, const void *b_)
 189 {
 190         struct possible_tag *a = (struct possible_tag *)a_;
 191         struct possible_tag *b = (struct possible_tag *)b_;
 192         if (a->depth != b->depth)
 193                 return a->depth - b->depth;
 194         if (a->found_order != b->found_order)
 195                 return a->found_order - b->found_order;
 196         return 0;
 197 }
 198
 199 static unsigned long finish_depth_computation(
 200         struct commit_list **list,
 201         struct possible_tag *best)
 202 {
 203         unsigned long seen_commits = 0;
 204         while (*list) {
 205                 struct commit *c = pop_commit(list);
 206                 struct commit_list *parents = c->parents;
 207                 seen_commits++;
 208                 if (c->object.flags & best->flag_within) {
 209                         struct commit_list *a = *list;
 210                         while (a) {
 211                                 struct commit *i = a->item;
 212                                 if (!(i->object.flags & best->flag_within))
 213                                         break;
 214                                 a = a->next;
 215                         }
 216                         if (!a)
 217                                 break;
 218                 } else
 219                         best->depth++;
 220                 while (parents) {
 221                         struct commit *p = parents->item;
 222                         parse_commit(p);
 223                         if (!(p->object.flags & SEEN))
 224                                 commit_list_insert_by_date(p, list);
 225                         p->object.flags |= c->object.flags;
 226                         parents = parents->next;
 227                 }
 228         }
 229         return seen_commits;
 230 }
 231
 232 static void display_name(struct commit_name *n)
 233 {
 234         if (n->prio == 2 && !n->tag) {
 235                 n->tag = lookup_tag(n->sha1);
 236                 if (!n->tag || parse_tag(n->tag))
 237                         die(_("annotated tag %s not available"), n->path);
 238         }
 239         if (n->tag && !n->name_checked) {
 240                 if (!n->tag->tag)
 241                         die(_("annotated tag %s has no embedded name"), n->path);
 242                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 243                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 244                 n->name_checked = 1;
 245         }
 246
 247         if (n->tag)
 248                 printf("%s", n->tag->tag);
 249         else
 250                 printf("%s", n->path);
 251 }
 252
 253 static void show_suffix(int depth, const unsigned char *sha1)
 254 {
 255         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 256 }
 257
 258 static void describe(const char *arg, int last_one)
 259 {
 260         unsigned char sha1[20];
 261         struct commit *cmit, *gave_up_on = NULL;
 262         struct commit_list *list;
 263         struct commit_name *n;
 264         struct possible_tag all_matches[MAX_TAGS];
 265         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 266         unsigned long seen_commits = 0;
 267         unsigned int unannotated_cnt = 0;
 268
 269         if (get_sha1(arg, sha1))
 270                 die(_("Not a valid object name %s"), arg);
 271         cmit = lookup_commit_reference(sha1);
 272         if (!cmit)
 273                 die(_("%s is not a valid '%s' object"), arg, commit_type);
 274
 275         n = find_commit_name(cmit->object.sha1);
 276         if (n && (tags || all || n->prio == 2)) {
 277                 /*
 278                  * Exact match to an existing ref.
 279                  */
 280                 display_name(n);
 281                 if (longformat)
 282                         show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 283                 if (dirty)
 284                         printf("%s", dirty);
 285                 printf("\n");
 286                 return;
 287         }
 288
 289         if (!max_candidates)
 290                 die(_("no tag exactly matches '%s'"), sha1_to_hex(cmit->object.sha1));
 291         if (debug)
 292                 fprintf(stderr, _("searching to describe %s\n"), arg);
 293
 294         if (!have_util) {
 295                 for_each_hash(&names, set_util, NULL);
 296                 have_util = 1;
 297         }
 298
 299         list = NULL;
 300         cmit->object.flags = SEEN;
 301         commit_list_insert(cmit, &list);
 302         while (list) {
 303                 struct commit *c = pop_commit(&list);
 304                 struct commit_list *parents = c->parents;
 305                 seen_commits++;
 306                 n = c->util;
 307                 if (n) {
 308                         if (!tags && !all && n->prio < 2) {
 309                                 unannotated_cnt++;
 310                         } else if (match_cnt < max_candidates) {
 311                                 struct possible_tag *t = &all_matches[match_cnt++];
 312                                 t->name = n;
 313                                 t->depth = seen_commits - 1;
 314                                 t->flag_within = 1u << match_cnt;
 315                                 t->found_order = match_cnt;
 316                                 c->object.flags |= t->flag_within;
 317                                 if (n->prio == 2)
 318                                         annotated_cnt++;
 319                         }
 320                         else {
 321                                 gave_up_on = c;
 322                                 break;
 323                         }
 324                 }
 325                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 326                         struct possible_tag *t = &all_matches[cur_match];
 327                         if (!(c->object.flags & t->flag_within))
 328                                 t->depth++;
 329                 }
 330                 if (annotated_cnt && !list) {
 331                         if (debug)
 332                                 fprintf(stderr, _("finished search at %s\n"),
 333                                         sha1_to_hex(c->object.sha1));
 334                         break;
 335                 }
 336                 while (parents) {
 337                         struct commit *p = parents->item;
 338                         parse_commit(p);
 339                         if (!(p->object.flags & SEEN))
 340                                 commit_list_insert_by_date(p, &list);
 341                         p->object.flags |= c->object.flags;
 342                         parents = parents->next;
 343
 344                         if (first_parent)
 345                                 break;
 346                 }
 347         }
 348
 349         if (!match_cnt) {
 350                 const unsigned char *sha1 = cmit->object.sha1;
 351                 if (always) {
 352                         printf("%s", find_unique_abbrev(sha1, abbrev));
 353                         if (dirty)
 354                                 printf("%s", dirty);
 355                         printf("\n");
 356                         return;
 357                 }
 358                 if (unannotated_cnt)
 359                         die(_("No annotated tags can describe '%s'.\n"
 360                             "However, there were unannotated tags: try --tags."),
 361                             sha1_to_hex(sha1));
 362                 else
 363                         die(_("No tags can describe '%s'.\n"
 364                             "Try --always, or create some tags."),
 365                             sha1_to_hex(sha1));
 366         }
 367
 368         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 369
 370         if (gave_up_on) {
 371                 commit_list_insert_by_date(gave_up_on, &list);
 372                 seen_commits--;
 373         }
 374         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 375         free_commit_list(list);
 376
 377         if (debug) {
 378                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 379                         struct possible_tag *t = &all_matches[cur_match];
 380                         fprintf(stderr, " %-11s %8d %s\n",
 381                                 prio_names[t->name->prio],
 382                                 t->depth, t->name->path);
 383                 }
 384                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 385                 if (gave_up_on) {
 386                         fprintf(stderr,
 387                                 _("more than %i tags found; listed %i most recent\n"
 388                                 "gave up search at %s\n"),
 389                                 max_candidates, max_candidates,
 390                                 sha1_to_hex(gave_up_on->object.sha1));
 391                 }
 392         }
 393
 394         display_name(all_matches[0].name);
 395         if (abbrev)
 396                 show_suffix(all_matches[0].depth, cmit->object.sha1);
 397         if (dirty)
 398                 printf("%s", dirty);
 399         printf("\n");
 400
 401         if (!last_one)
 402                 clear_commit_marks(cmit, -1);
 403 }
 404
 405 int cmd_describe(int argc, const char **argv, const char *prefix)
 406 {
 407         int contains = 0;
 408         struct option options[] = {
 409                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 410                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
 411                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
 412                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
 413                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
 414                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
 415                 OPT__ABBREV(&abbrev),
 416                 OPT_SET_INT(0, "exact-match", &max_candidates,
 417                             N_("only output exact matches"), 0),
 418                 OPT_INTEGER(0, "candidates", &max_candidates,
 419                             N_("consider <n> most recent tags (default: 10)")),
 420                 OPT_STRING(0, "match",       &pattern, N_("pattern"),
 421                            N_("only consider tags matching <pattern>")),
 422                 OPT_BOOL(0, "always",        &always,
 423                         N_("show abbreviated commit object as fallback")),
 424                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 425                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 426                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 427                 OPT_END(),
 428         };
 429
 430         git_config(git_default_config, NULL);
 431         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 432         if (abbrev < 0)
 433                 abbrev = DEFAULT_ABBREV;
 434
 435         if (max_candidates < 0)
 436                 max_candidates = 0;
 437         else if (max_candidates > MAX_TAGS)
 438                 max_candidates = MAX_TAGS;
 439
 440         save_commit_buffer = 0;
 441
 442         if (longformat && abbrev == 0)
 443                 die(_("--long is incompatible with --abbrev=0"));
 444
 445         if (contains) {
 446                 struct argv_array args;
 447
 448                 argv_array_init(&args);
 449                 argv_array_pushl(&args, "name-rev",
 450                                  "--peel-tag", "--name-only", "--no-undefined",
 451                                  NULL);
 452                 if (always)
 453                         argv_array_push(&args, "--always");
 454                 if (!all) {
 455                         argv_array_push(&args, "--tags");
 456                         if (pattern)
 457                                 argv_array_pushf(&args, "--refs=refs/tags/%s", pattern);
 458                 }
 459                 while (*argv) {
 460                         argv_array_push(&args, *argv);
 461                         argv++;
 462                 }
 463                 return cmd_name_rev(args.argc, args.argv, prefix);
 464         }
 465
 466         init_hash(&names);
 467         for_each_rawref(get_name, NULL);
 468         if (!names.nr && !always)
 469                 die(_("No names found, cannot describe anything."));
 470
 471         if (argc == 0) {
 472                 if (dirty) {
 473                         static struct lock_file index_lock;
 474                         int fd;
 475
 476                         read_cache_preload(NULL);
 477                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 478                                       NULL, NULL, NULL);
 479                         fd = hold_locked_index(&index_lock, 0);
 480                         if (0 <= fd)
 481                                 update_index_if_able(&the_index, &index_lock);
 482
 483                         if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
 484                                             diff_index_args, prefix))
 485                                 dirty = NULL;
 486                 }
 487                 describe("HEAD", 1);
 488         } else if (dirty) {
 489                 die(_("--dirty is incompatible with committishes"));
 490         } else {
 491                 while (argc-- > 0) {
 492                         describe(*argv++, argc == 0);
 493                 }
 494         }
 495         return 0;
 496 }