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 struct commit_name *find_commit_name(const unsigned char *peeled)
  60 {
  61         struct commit_name key;
  62         hashmap_entry_init(&key, sha1hash(peeled));
  63         return hashmap_get(&names, &key, peeled);
  64 }
  65
  66 static int replace_name(struct commit_name *e,
  67                                int prio,
  68                                const unsigned char *sha1,
  69                                struct tag **tag)
  70 {
  71         if (!e || e->prio < prio)
  72                 return 1;
  73
  74         if (e->prio == 2 && prio == 2) {
  75                 /* Multiple annotated tags point to the same commit.
  76                  * Select one to keep based upon their tagger date.
  77                  */
  78                 struct tag *t;
  79
  80                 if (!e->tag) {
  81                         t = lookup_tag(e->sha1);
  82                         if (!t || parse_tag(t))
  83                                 return 1;
  84                         e->tag = t;
  85                 }
  86
  87                 t = lookup_tag(sha1);
  88                 if (!t || parse_tag(t))
  89                         return 0;
  90                 *tag = t;
  91
  92                 if (e->tag->date < t->date)
  93                         return 1;
  94         }
  95
  96         return 0;
  97 }
  98
  99 static void add_to_known_names(const char *path,
 100                                const unsigned char *peeled,
 101                                int prio,
 102                                const unsigned char *sha1)
 103 {
 104         struct commit_name *e = find_commit_name(peeled);
 105         struct tag *tag = NULL;
 106         if (replace_name(e, prio, sha1, &tag)) {
 107                 if (!e) {
 108                         e = xmalloc(sizeof(struct commit_name));
 109                         hashcpy(e->peeled, peeled);
 110                         hashmap_entry_init(e, sha1hash(peeled));
 111                         hashmap_add(&names, e);
 112                         e->path = NULL;
 113                 }
 114                 e->tag = tag;
 115                 e->prio = prio;
 116                 e->name_checked = 0;
 117                 hashcpy(e->sha1, sha1);
 118                 free(e->path);
 119                 e->path = xstrdup(path);
 120         }
 121 }
 122
 123 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 124 {
 125         int is_tag = starts_with(path, "refs/tags/");
 126         unsigned char peeled[20];
 127         int is_annotated, prio;
 128
 129         /* Reject anything outside refs/tags/ unless --all */
 130         if (!all && !is_tag)
 131                 return 0;
 132
 133         /* Accept only tags that match the pattern, if given */
 134         if (pattern && (!is_tag || wildmatch(pattern, path + 10, 0, NULL)))
 135                 return 0;
 136
 137         /* Is it annotated? */
 138         if (!peel_ref(path, peeled)) {
 139                 is_annotated = !!hashcmp(sha1, peeled);
 140         } else {
 141                 hashcpy(peeled, sha1);
 142                 is_annotated = 0;
 143         }
 144
 145         /*
 146          * By default, we only use annotated tags, but with --tags
 147          * we fall back to lightweight ones (even without --tags,
 148          * we still remember lightweight ones, only to give hints
 149          * in an error message).  --all allows any refs to be used.
 150          */
 151         if (is_annotated)
 152                 prio = 2;
 153         else if (is_tag)
 154                 prio = 1;
 155         else
 156                 prio = 0;
 157
 158         add_to_known_names(all ? path + 5 : path + 10, peeled, prio, sha1);
 159         return 0;
 160 }
 161
 162 struct possible_tag {
 163         struct commit_name *name;
 164         int depth;
 165         int found_order;
 166         unsigned flag_within;
 167 };
 168
 169 static int compare_pt(const void *a_, const void *b_)
 170 {
 171         struct possible_tag *a = (struct possible_tag *)a_;
 172         struct possible_tag *b = (struct possible_tag *)b_;
 173         if (a->depth != b->depth)
 174                 return a->depth - b->depth;
 175         if (a->found_order != b->found_order)
 176                 return a->found_order - b->found_order;
 177         return 0;
 178 }
 179
 180 static unsigned long finish_depth_computation(
 181         struct commit_list **list,
 182         struct possible_tag *best)
 183 {
 184         unsigned long seen_commits = 0;
 185         while (*list) {
 186                 struct commit *c = pop_commit(list);
 187                 struct commit_list *parents = c->parents;
 188                 seen_commits++;
 189                 if (c->object.flags & best->flag_within) {
 190                         struct commit_list *a = *list;
 191                         while (a) {
 192                                 struct commit *i = a->item;
 193                                 if (!(i->object.flags & best->flag_within))
 194                                         break;
 195                                 a = a->next;
 196                         }
 197                         if (!a)
 198                                 break;
 199                 } else
 200                         best->depth++;
 201                 while (parents) {
 202                         struct commit *p = parents->item;
 203                         parse_commit(p);
 204                         if (!(p->object.flags & SEEN))
 205                                 commit_list_insert_by_date(p, list);
 206                         p->object.flags |= c->object.flags;
 207                         parents = parents->next;
 208                 }
 209         }
 210         return seen_commits;
 211 }
 212
 213 static void display_name(struct commit_name *n)
 214 {
 215         if (n->prio == 2 && !n->tag) {
 216                 n->tag = lookup_tag(n->sha1);
 217                 if (!n->tag || parse_tag(n->tag))
 218                         die(_("annotated tag %s not available"), n->path);
 219         }
 220         if (n->tag && !n->name_checked) {
 221                 if (!n->tag->tag)
 222                         die(_("annotated tag %s has no embedded name"), n->path);
 223                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 224                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 225                 n->name_checked = 1;
 226         }
 227
 228         if (n->tag)
 229                 printf("%s", n->tag->tag);
 230         else
 231                 printf("%s", n->path);
 232 }
 233
 234 static void show_suffix(int depth, const unsigned char *sha1)
 235 {
 236         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 237 }
 238
 239 static void describe(const char *arg, int last_one)
 240 {
 241         unsigned char sha1[20];
 242         struct commit *cmit, *gave_up_on = NULL;
 243         struct commit_list *list;
 244         struct commit_name *n;
 245         struct possible_tag all_matches[MAX_TAGS];
 246         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 247         unsigned long seen_commits = 0;
 248         unsigned int unannotated_cnt = 0;
 249
 250         if (get_sha1(arg, sha1))
 251                 die(_("Not a valid object name %s"), arg);
 252         cmit = lookup_commit_reference(sha1);
 253         if (!cmit)
 254                 die(_("%s is not a valid '%s' object"), arg, commit_type);
 255
 256         n = find_commit_name(cmit->object.sha1);
 257         if (n && (tags || all || n->prio == 2)) {
 258                 /*
 259                  * Exact match to an existing ref.
 260                  */
 261                 display_name(n);
 262                 if (longformat)
 263                         show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 264                 if (dirty)
 265                         printf("%s", dirty);
 266                 printf("\n");
 267                 return;
 268         }
 269
 270         if (!max_candidates)
 271                 die(_("no tag exactly matches '%s'"), sha1_to_hex(cmit->object.sha1));
 272         if (debug)
 273                 fprintf(stderr, _("searching to describe %s\n"), arg);
 274
 275         if (!have_util) {
 276                 struct hashmap_iter iter;
 277                 struct commit *c;
 278                 struct commit_name *n = hashmap_iter_first(&names, &iter);
 279                 for (; n; n = hashmap_iter_next(&iter)) {
 280                         c = lookup_commit_reference_gently(n->peeled, 1);
 281                         if (c)
 282                                 c->util = n;
 283                 }
 284                 have_util = 1;
 285         }
 286
 287         list = NULL;
 288         cmit->object.flags = SEEN;
 289         commit_list_insert(cmit, &list);
 290         while (list) {
 291                 struct commit *c = pop_commit(&list);
 292                 struct commit_list *parents = c->parents;
 293                 seen_commits++;
 294                 n = c->util;
 295                 if (n) {
 296                         if (!tags && !all && n->prio < 2) {
 297                                 unannotated_cnt++;
 298                         } else if (match_cnt < max_candidates) {
 299                                 struct possible_tag *t = &all_matches[match_cnt++];
 300                                 t->name = n;
 301                                 t->depth = seen_commits - 1;
 302                                 t->flag_within = 1u << match_cnt;
 303                                 t->found_order = match_cnt;
 304                                 c->object.flags |= t->flag_within;
 305                                 if (n->prio == 2)
 306                                         annotated_cnt++;
 307                         }
 308                         else {
 309                                 gave_up_on = c;
 310                                 break;
 311                         }
 312                 }
 313                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 314                         struct possible_tag *t = &all_matches[cur_match];
 315                         if (!(c->object.flags & t->flag_within))
 316                                 t->depth++;
 317                 }
 318                 if (annotated_cnt && !list) {
 319                         if (debug)
 320                                 fprintf(stderr, _("finished search at %s\n"),
 321                                         sha1_to_hex(c->object.sha1));
 322                         break;
 323                 }
 324                 while (parents) {
 325                         struct commit *p = parents->item;
 326                         parse_commit(p);
 327                         if (!(p->object.flags & SEEN))
 328                                 commit_list_insert_by_date(p, &list);
 329                         p->object.flags |= c->object.flags;
 330                         parents = parents->next;
 331
 332                         if (first_parent)
 333                                 break;
 334                 }
 335         }
 336
 337         if (!match_cnt) {
 338                 const unsigned char *sha1 = cmit->object.sha1;
 339                 if (always) {
 340                         printf("%s", find_unique_abbrev(sha1, abbrev));
 341                         if (dirty)
 342                                 printf("%s", dirty);
 343                         printf("\n");
 344                         return;
 345                 }
 346                 if (unannotated_cnt)
 347                         die(_("No annotated tags can describe '%s'.\n"
 348                             "However, there were unannotated tags: try --tags."),
 349                             sha1_to_hex(sha1));
 350                 else
 351                         die(_("No tags can describe '%s'.\n"
 352                             "Try --always, or create some tags."),
 353                             sha1_to_hex(sha1));
 354         }
 355
 356         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 357
 358         if (gave_up_on) {
 359                 commit_list_insert_by_date(gave_up_on, &list);
 360                 seen_commits--;
 361         }
 362         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 363         free_commit_list(list);
 364
 365         if (debug) {
 366                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 367                         struct possible_tag *t = &all_matches[cur_match];
 368                         fprintf(stderr, " %-11s %8d %s\n",
 369                                 prio_names[t->name->prio],
 370                                 t->depth, t->name->path);
 371                 }
 372                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 373                 if (gave_up_on) {
 374                         fprintf(stderr,
 375                                 _("more than %i tags found; listed %i most recent\n"
 376                                 "gave up search at %s\n"),
 377                                 max_candidates, max_candidates,
 378                                 sha1_to_hex(gave_up_on->object.sha1));
 379                 }
 380         }
 381
 382         display_name(all_matches[0].name);
 383         if (abbrev)
 384                 show_suffix(all_matches[0].depth, cmit->object.sha1);
 385         if (dirty)
 386                 printf("%s", dirty);
 387         printf("\n");
 388
 389         if (!last_one)
 390                 clear_commit_marks(cmit, -1);
 391 }
 392
 393 int cmd_describe(int argc, const char **argv, const char *prefix)
 394 {
 395         int contains = 0;
 396         struct option options[] = {
 397                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 398                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
 399                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
 400                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
 401                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
 402                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
 403                 OPT__ABBREV(&abbrev),
 404                 OPT_SET_INT(0, "exact-match", &max_candidates,
 405                             N_("only output exact matches"), 0),
 406                 OPT_INTEGER(0, "candidates", &max_candidates,
 407                             N_("consider <n> most recent tags (default: 10)")),
 408                 OPT_STRING(0, "match",       &pattern, N_("pattern"),
 409                            N_("only consider tags matching <pattern>")),
 410                 OPT_BOOL(0, "always",        &always,
 411                         N_("show abbreviated commit object as fallback")),
 412                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 413                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 414                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 415                 OPT_END(),
 416         };
 417
 418         git_config(git_default_config, NULL);
 419         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 420         if (abbrev < 0)
 421                 abbrev = DEFAULT_ABBREV;
 422
 423         if (max_candidates < 0)
 424                 max_candidates = 0;
 425         else if (max_candidates > MAX_TAGS)
 426                 max_candidates = MAX_TAGS;
 427
 428         save_commit_buffer = 0;
 429
 430         if (longformat && abbrev == 0)
 431                 die(_("--long is incompatible with --abbrev=0"));
 432
 433         if (contains) {
 434                 struct argv_array args;
 435
 436                 argv_array_init(&args);
 437                 argv_array_pushl(&args, "name-rev",
 438                                  "--peel-tag", "--name-only", "--no-undefined",
 439                                  NULL);
 440                 if (always)
 441                         argv_array_push(&args, "--always");
 442                 if (!all) {
 443                         argv_array_push(&args, "--tags");
 444                         if (pattern)
 445                                 argv_array_pushf(&args, "--refs=refs/tags/%s", pattern);
 446                 }
 447                 while (*argv) {
 448                         argv_array_push(&args, *argv);
 449                         argv++;
 450                 }
 451                 return cmd_name_rev(args.argc, args.argv, prefix);
 452         }
 453
 454         hashmap_init(&names, (hashmap_cmp_fn) commit_name_cmp, 0);
 455         for_each_rawref(get_name, NULL);
 456         if (!names.size && !always)
 457                 die(_("No names found, cannot describe anything."));
 458
 459         if (argc == 0) {
 460                 if (dirty) {
 461                         static struct lock_file index_lock;
 462                         int fd;
 463
 464                         read_cache_preload(NULL);
 465                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 466                                       NULL, NULL, NULL);
 467                         fd = hold_locked_index(&index_lock, 0);
 468                         if (0 <= fd)
 469                                 update_index_if_able(&the_index, &index_lock);
 470
 471                         if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
 472                                             diff_index_args, prefix))
 473                                 dirty = NULL;
 474                 }
 475                 describe("HEAD", 1);
 476         } else if (dirty) {
 477                 die(_("--dirty is incompatible with commit-ishes"));
 478         } else {
 479                 while (argc-- > 0)
 480                         describe(*argv++, argc == 0);
 481         }
 482         return 0;
 483 }