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