builtin/describe.c

   1 #include "cache.h"
   2 #include "lockfile.h"
   3 #include "commit.h"
   4 #include "tag.h"
   5 #include "refs.h"
   6 #include "builtin.h"
   7 #include "exec_cmd.h"
   8 #include "parse-options.h"
   9 #include "diff.h"
  10 #include "hashmap.h"
  11 #include "argv-array.h"
  12
  13 #define SEEN            (1u << 0)
  14 #define MAX_TAGS        (FLAG_BITS - 1)
  15
  16 static const char * const describe_usage[] = {
  17         N_("git describe [<options>] [<commit-ish>...]"),
  18         N_("git describe [<options>] --dirty"),
  19         NULL
  20 };
  21
  22 static int debug;       /* Display lots of verbose info */
  23 static int all; /* Any valid ref can be used */
  24 static int tags;        /* Allow lightweight tags */
  25 static int longformat;
  26 static int first_parent;
  27 static int abbrev = -1; /* unspecified */
  28 static int max_candidates = 10;
  29 static struct hashmap names;
  30 static int have_util;
  31 static const char *pattern;
  32 static int always;
  33 static const char *dirty;
  34
  35 /* diff-index command arguments to check if working tree is dirty. */
  36 static const char *diff_index_args[] = {
  37         "diff-index", "--quiet", "HEAD", "--", NULL
  38 };
  39
  40 struct commit_name {
  41         struct hashmap_entry entry;
  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
  50 static const char *prio_names[] = {
  51         "head", "lightweight", "annotated",
  52 };
  53
  54 static int commit_name_cmp(const struct commit_name *cn1,
  55                 const struct commit_name *cn2, const void *peeled)
  56 {
  57         return hashcmp(cn1->peeled, peeled ? peeled : cn2->peeled);
  58 }
  59
  60 static inline struct commit_name *find_commit_name(const unsigned char *peeled)
  61 {
  62         return hashmap_get_from_hash(&names, sha1hash(peeled), peeled);
  63 }
  64
  65 static int replace_name(struct commit_name *e,
  66                                int prio,
  67                                const unsigned char *sha1,
  68                                struct tag **tag)
  69 {
  70         if (!e || e->prio < prio)
  71                 return 1;
  72
  73         if (e->prio == 2 && prio == 2) {
  74                 /* Multiple annotated tags point to the same commit.
  75                  * Select one to keep based upon their tagger date.
  76                  */
  77                 struct tag *t;
  78
  79                 if (!e->tag) {
  80                         t = lookup_tag(e->sha1);
  81                         if (!t || parse_tag(t))
  82                                 return 1;
  83                         e->tag = t;
  84                 }
  85
  86                 t = lookup_tag(sha1);
  87                 if (!t || parse_tag(t))
  88                         return 0;
  89                 *tag = t;
  90
  91                 if (e->tag->date < t->date)
  92                         return 1;
  93         }
  94
  95         return 0;
  96 }
  97
  98 static void add_to_known_names(const char *path,
  99                                const unsigned char *peeled,
 100                                int prio,
 101                                const unsigned char *sha1)
 102 {
 103         struct commit_name *e = find_commit_name(peeled);
 104         struct tag *tag = NULL;
 105         if (replace_name(e, prio, sha1, &tag)) {
 106                 if (!e) {
 107                         e = xmalloc(sizeof(struct commit_name));
 108                         hashcpy(e->peeled, peeled);
 109                         hashmap_entry_init(e, sha1hash(peeled));
 110                         hashmap_add(&names, e);
 111                         e->path = NULL;
 112                 }
 113                 e->tag = tag;
 114                 e->prio = prio;
 115                 e->name_checked = 0;
 116                 hashcpy(e->sha1, sha1);
 117                 free(e->path);
 118                 e->path = xstrdup(path);
 119         }
 120 }
 121
 122 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 123 {
 124         int is_tag = starts_with(path, "refs/tags/");
 125         unsigned char peeled[20];
 126         int is_annotated, prio;
 127
 128         /* Reject anything outside refs/tags/ unless --all */
 129         if (!all && !is_tag)
 130                 return 0;
 131
 132         /* Accept only tags that match the pattern, if given */
 133         if (pattern && (!is_tag || wildmatch(pattern, path + 10, 0, NULL)))
 134                 return 0;
 135
 136         /* Is it annotated? */
 137         if (!peel_ref(path, peeled)) {
 138                 is_annotated = !!hashcmp(sha1, peeled);
 139         } else {
 140                 hashcpy(peeled, sha1);
 141                 is_annotated = 0;
 142         }
 143
 144         /*
 145          * By default, we only use annotated tags, but with --tags
 146          * we fall back to lightweight ones (even without --tags,
 147          * we still remember lightweight ones, only to give hints
 148          * in an error message).  --all allows any refs to be used.
 149          */
 150         if (is_annotated)
 151                 prio = 2;
 152         else if (is_tag)
 153                 prio = 1;
 154         else
 155                 prio = 0;
 156
 157         add_to_known_names(all ? path + 5 : path + 10, peeled, prio, sha1);
 158         return 0;
 159 }
 160
 161 struct possible_tag {
 162         struct commit_name *name;
 163         int depth;
 164         int found_order;
 165         unsigned flag_within;
 166 };
 167
 168 static int compare_pt(const void *a_, const void *b_)
 169 {
 170         struct possible_tag *a = (struct possible_tag *)a_;
 171         struct possible_tag *b = (struct possible_tag *)b_;
 172         if (a->depth != b->depth)
 173                 return a->depth - b->depth;
 174         if (a->found_order != b->found_order)
 175                 return a->found_order - b->found_order;
 176         return 0;
 177 }
 178
 179 static unsigned long finish_depth_computation(
 180         struct commit_list **list,
 181         struct possible_tag *best)
 182 {
 183         unsigned long seen_commits = 0;
 184         while (*list) {
 185                 struct commit *c = pop_commit(list);
 186                 struct commit_list *parents = c->parents;
 187                 seen_commits++;
 188                 if (c->object.flags & best->flag_within) {
 189                         struct commit_list *a = *list;
 190                         while (a) {
 191                                 struct commit *i = a->item;
 192                                 if (!(i->object.flags & best->flag_within))
 193                                         break;
 194                                 a = a->next;
 195                         }
 196                         if (!a)
 197                                 break;
 198                 } else
 199                         best->depth++;
 200                 while (parents) {
 201                         struct commit *p = parents->item;
 202                         parse_commit(p);
 203                         if (!(p->object.flags & SEEN))
 204                                 commit_list_insert_by_date(p, list);
 205                         p->object.flags |= c->object.flags;
 206                         parents = parents->next;
 207                 }
 208         }
 209         return seen_commits;
 210 }
 211
 212 static void display_name(struct commit_name *n)
 213 {
 214         if (n->prio == 2 && !n->tag) {
 215                 n->tag = lookup_tag(n->sha1);
 216                 if (!n->tag || parse_tag(n->tag))
 217                         die(_("annotated tag %s not available"), n->path);
 218         }
 219         if (n->tag && !n->name_checked) {
 220                 if (!n->tag->tag)
 221                         die(_("annotated tag %s has no embedded name"), n->path);
 222                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 223                         warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 224                 n->name_checked = 1;
 225         }
 226
 227         if (n->tag)
 228                 printf("%s", n->tag->tag);
 229         else
 230                 printf("%s", n->path);
 231 }
 232
 233 static void show_suffix(int depth, const unsigned char *sha1)
 234 {
 235         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 236 }
 237
 238 static void describe(const char *arg, int last_one)
 239 {
 240         unsigned char sha1[20];
 241         struct commit *cmit, *gave_up_on = NULL;
 242         struct commit_list *list;
 243         struct commit_name *n;
 244         struct possible_tag all_matches[MAX_TAGS];
 245         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 246         unsigned long seen_commits = 0;
 247         unsigned int unannotated_cnt = 0;
 248
 249         if (get_sha1(arg, sha1))
 250                 die(_("Not a valid object name %s"), arg);
 251         cmit = lookup_commit_reference(sha1);
 252         if (!cmit)
 253                 die(_("%s is not a valid '%s' object"), arg, commit_type);
 254
 255         n = find_commit_name(cmit->object.sha1);
 256         if (n && (tags || all || n->prio == 2)) {
 257                 /*
 258                  * Exact match to an existing ref.
 259                  */
 260                 display_name(n);
 261                 if (longformat)
 262                         show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 263                 if (dirty)
 264                         printf("%s", dirty);
 265                 printf("\n");
 266                 return;
 267         }
 268
 269         if (!max_candidates)
 270                 die(_("no tag exactly matches '%s'"), sha1_to_hex(cmit->object.sha1));
 271         if (debug)
 272                 fprintf(stderr, _("searching to describe %s\n"), arg);
 273
 274         if (!have_util) {
 275                 struct hashmap_iter iter;
 276                 struct commit *c;
 277                 struct commit_name *n = hashmap_iter_first(&names, &iter);
 278                 for (; n; n = hashmap_iter_next(&iter)) {
 279                         c = lookup_commit_reference_gently(n->peeled, 1);
 280                         if (c)
 281                                 c->util = n;
 282                 }
 283                 have_util = 1;
 284         }
 285
 286         list = NULL;
 287         cmit->object.flags = SEEN;
 288         commit_list_insert(cmit, &list);
 289         while (list) {
 290                 struct commit *c = pop_commit(&list);
 291                 struct commit_list *parents = c->parents;
 292                 seen_commits++;
 293                 n = c->util;
 294                 if (n) {
 295                         if (!tags && !all && n->prio < 2) {
 296                                 unannotated_cnt++;
 297                         } else if (match_cnt < max_candidates) {
 298                                 struct possible_tag *t = &all_matches[match_cnt++];
 299                                 t->name = n;
 300                                 t->depth = seen_commits - 1;
 301                                 t->flag_within = 1u << match_cnt;
 302                                 t->found_order = match_cnt;
 303                                 c->object.flags |= t->flag_within;
 304                                 if (n->prio == 2)
 305                                         annotated_cnt++;
 306                         }
 307                         else {
 308                                 gave_up_on = c;
 309                                 break;
 310                         }
 311                 }
 312                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 313                         struct possible_tag *t = &all_matches[cur_match];
 314                         if (!(c->object.flags & t->flag_within))
 315                                 t->depth++;
 316                 }
 317                 if (annotated_cnt && !list) {
 318                         if (debug)
 319                                 fprintf(stderr, _("finished search at %s\n"),
 320                                         sha1_to_hex(c->object.sha1));
 321                         break;
 322                 }
 323                 while (parents) {
 324                         struct commit *p = parents->item;
 325                         parse_commit(p);
 326                         if (!(p->object.flags & SEEN))
 327                                 commit_list_insert_by_date(p, &list);
 328                         p->object.flags |= c->object.flags;
 329                         parents = parents->next;
 330
 331                         if (first_parent)
 332                                 break;
 333                 }
 334         }
 335
 336         if (!match_cnt) {
 337                 const unsigned char *sha1 = cmit->object.sha1;
 338                 if (always) {
 339                         printf("%s", find_unique_abbrev(sha1, abbrev));
 340                         if (dirty)
 341                                 printf("%s", dirty);
 342                         printf("\n");
 343                         return;
 344                 }
 345                 if (unannotated_cnt)
 346                         die(_("No annotated tags can describe '%s'.\n"
 347                             "However, there were unannotated tags: try --tags."),
 348                             sha1_to_hex(sha1));
 349                 else
 350                         die(_("No tags can describe '%s'.\n"
 351                             "Try --always, or create some tags."),
 352                             sha1_to_hex(sha1));
 353         }
 354
 355         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 356
 357         if (gave_up_on) {
 358                 commit_list_insert_by_date(gave_up_on, &list);
 359                 seen_commits--;
 360         }
 361         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 362         free_commit_list(list);
 363
 364         if (debug) {
 365                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 366                         struct possible_tag *t = &all_matches[cur_match];
 367                         fprintf(stderr, " %-11s %8d %s\n",
 368                                 prio_names[t->name->prio],
 369                                 t->depth, t->name->path);
 370                 }
 371                 fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 372                 if (gave_up_on) {
 373                         fprintf(stderr,
 374                                 _("more than %i tags found; listed %i most recent\n"
 375                                 "gave up search at %s\n"),
 376                                 max_candidates, max_candidates,
 377                                 sha1_to_hex(gave_up_on->object.sha1));
 378                 }
 379         }
 380
 381         display_name(all_matches[0].name);
 382         if (abbrev)
 383                 show_suffix(all_matches[0].depth, cmit->object.sha1);
 384         if (dirty)
 385                 printf("%s", dirty);
 386         printf("\n");
 387
 388         if (!last_one)
 389                 clear_commit_marks(cmit, -1);
 390 }
 391
 392 int cmd_describe(int argc, const char **argv, const char *prefix)
 393 {
 394         int contains = 0;
 395         struct option options[] = {
 396                 OPT_BOOL(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 397                 OPT_BOOL(0, "debug",      &debug, N_("debug search strategy on stderr")),
 398                 OPT_BOOL(0, "all",        &all, N_("use any ref")),
 399                 OPT_BOOL(0, "tags",       &tags, N_("use any tag, even unannotated")),
 400                 OPT_BOOL(0, "long",       &longformat, N_("always use long format")),
 401                 OPT_BOOL(0, "first-parent", &first_parent, N_("only follow first parent")),
 402                 OPT__ABBREV(&abbrev),
 403                 OPT_SET_INT(0, "exact-match", &max_candidates,
 404                             N_("only output exact matches"), 0),
 405                 OPT_INTEGER(0, "candidates", &max_candidates,
 406                             N_("consider <n> most recent tags (default: 10)")),
 407                 OPT_STRING(0, "match",       &pattern, N_("pattern"),
 408                            N_("only consider tags matching <pattern>")),
 409                 OPT_BOOL(0, "always",        &always,
 410                         N_("show abbreviated commit object as fallback")),
 411                 {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 412                         N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 413                         PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 414                 OPT_END(),
 415         };
 416
 417         git_config(git_default_config, NULL);
 418         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 419         if (abbrev < 0)
 420                 abbrev = DEFAULT_ABBREV;
 421
 422         if (max_candidates < 0)
 423                 max_candidates = 0;
 424         else if (max_candidates > MAX_TAGS)
 425                 max_candidates = MAX_TAGS;
 426
 427         save_commit_buffer = 0;
 428
 429         if (longformat && abbrev == 0)
 430                 die(_("--long is incompatible with --abbrev=0"));
 431
 432         if (contains) {
 433                 struct argv_array args;
 434
 435                 argv_array_init(&args);
 436                 argv_array_pushl(&args, "name-rev",
 437                                  "--peel-tag", "--name-only", "--no-undefined",
 438                                  NULL);
 439                 if (always)
 440                         argv_array_push(&args, "--always");
 441                 if (!all) {
 442                         argv_array_push(&args, "--tags");
 443                         if (pattern)
 444                                 argv_array_pushf(&args, "--refs=refs/tags/%s", pattern);
 445                 }
 446                 while (*argv) {
 447                         argv_array_push(&args, *argv);
 448                         argv++;
 449                 }
 450                 return cmd_name_rev(args.argc, args.argv, prefix);
 451         }
 452
 453         hashmap_init(&names, (hashmap_cmp_fn) commit_name_cmp, 0);
 454         for_each_rawref(get_name, NULL);
 455         if (!names.size && !always)
 456                 die(_("No names found, cannot describe anything."));
 457
 458         if (argc == 0) {
 459                 if (dirty) {
 460                         static struct lock_file index_lock;
 461                         int fd;
 462
 463                         read_cache_preload(NULL);
 464                         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 465                                       NULL, NULL, NULL);
 466                         fd = hold_locked_index(&index_lock, 0);
 467                         if (0 <= fd)
 468                                 update_index_if_able(&the_index, &index_lock);
 469
 470                         if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
 471                                             diff_index_args, prefix))
 472                                 dirty = NULL;
 473                 }
 474                 describe("HEAD", 1);
 475         } else if (dirty) {
 476                 die(_("--dirty is incompatible with commit-ishes"));
 477         } else {
 478                 while (argc-- > 0)
 479                         describe(*argv++, argc == 0);
 480         }
 481         return 0;
 482 }