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         "git describe [options] <committish>*",
  16         "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 abbrev = DEFAULT_ABBREV;
  25 static int max_candidates = 10;
  26 static struct hash_table names;
  27 static const char *pattern;
  28 static int always;
  29 static const char *dirty;
  30
  31 /* diff-index command arguments to check if working tree is dirty. */
  32 static const char *diff_index_args[] = {
  33         "diff-index", "--quiet", "HEAD", "--", NULL
  34 };
  35
  36
  37 struct commit_name {
  38         struct commit_name *next;
  39         unsigned char peeled[20];
  40         struct tag *tag;
  41         unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  42         unsigned name_checked:1;
  43         unsigned char sha1[20];
  44         const char *path;
  45 };
  46 static const char *prio_names[] = {
  47         "head", "lightweight", "annotated",
  48 };
  49
  50 static inline unsigned int hash_sha1(const unsigned char *sha1)
  51 {
  52         unsigned int hash;
  53         memcpy(&hash, sha1, sizeof(hash));
  54         return hash;
  55 }
  56
  57 static inline struct commit_name *find_commit_name(const unsigned char *peeled)
  58 {
  59         struct commit_name *n = lookup_hash(hash_sha1(peeled), &names);
  60         while (n && !!hashcmp(peeled, n->peeled))
  61                 n = n->next;
  62         return n;
  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                                struct commit *commit,
 100                                int prio,
 101                                const unsigned char *sha1)
 102 {
 103         const unsigned char *peeled = commit->object.sha1;
 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                         void **pos;
 109                         e = xmalloc(sizeof(struct commit_name));
 110                         commit->util = e;
 111                         hashcpy(e->peeled, peeled);
 112                         pos = insert_hash(hash_sha1(peeled), e, &names);
 113                         if (pos) {
 114                                 e->next = *pos;
 115                                 *pos = e;
 116                         } else {
 117                                 e->next = NULL;
 118                         }
 119                 }
 120                 e->tag = tag;
 121                 e->prio = prio;
 122                 e->name_checked = 0;
 123                 hashcpy(e->sha1, sha1);
 124                 e->path = path;
 125         }
 126 }
 127
 128 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 129 {
 130         int might_be_tag = !prefixcmp(path, "refs/tags/");
 131         struct commit *commit;
 132         struct object *object;
 133         unsigned char peeled[20];
 134         int is_tag, prio;
 135
 136         if (!all && !might_be_tag)
 137                 return 0;
 138
 139         if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
 140                 commit = lookup_commit_reference_gently(peeled, 1);
 141                 if (!commit)
 142                         return 0;
 143                 is_tag = !!hashcmp(sha1, commit->object.sha1);
 144         } else {
 145                 commit = lookup_commit_reference_gently(sha1, 1);
 146                 object = parse_object(sha1);
 147                 if (!commit || !object)
 148                         return 0;
 149                 is_tag = object->type == OBJ_TAG;
 150         }
 151
 152         /* If --all, then any refs are used.
 153          * If --tags, then any tags are used.
 154          * Otherwise only annotated tags are used.
 155          */
 156         if (might_be_tag) {
 157                 if (is_tag)
 158                         prio = 2;
 159                 else
 160                         prio = 1;
 161
 162                 if (pattern && fnmatch(pattern, path + 10, 0))
 163                         prio = 0;
 164         }
 165         else
 166                 prio = 0;
 167
 168         if (!all) {
 169                 if (!prio)
 170                         return 0;
 171         }
 172         add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
 173         return 0;
 174 }
 175
 176 struct possible_tag {
 177         struct commit_name *name;
 178         int depth;
 179         int found_order;
 180         unsigned flag_within;
 181 };
 182
 183 static int compare_pt(const void *a_, const void *b_)
 184 {
 185         struct possible_tag *a = (struct possible_tag *)a_;
 186         struct possible_tag *b = (struct possible_tag *)b_;
 187         if (a->depth != b->depth)
 188                 return a->depth - b->depth;
 189         if (a->found_order != b->found_order)
 190                 return a->found_order - b->found_order;
 191         return 0;
 192 }
 193
 194 static unsigned long finish_depth_computation(
 195         struct commit_list **list,
 196         struct possible_tag *best)
 197 {
 198         unsigned long seen_commits = 0;
 199         while (*list) {
 200                 struct commit *c = pop_commit(list);
 201                 struct commit_list *parents = c->parents;
 202                 seen_commits++;
 203                 if (c->object.flags & best->flag_within) {
 204                         struct commit_list *a = *list;
 205                         while (a) {
 206                                 struct commit *i = a->item;
 207                                 if (!(i->object.flags & best->flag_within))
 208                                         break;
 209                                 a = a->next;
 210                         }
 211                         if (!a)
 212                                 break;
 213                 } else
 214                         best->depth++;
 215                 while (parents) {
 216                         struct commit *p = parents->item;
 217                         parse_commit(p);
 218                         if (!(p->object.flags & SEEN))
 219                                 insert_by_date(p, list);
 220                         p->object.flags |= c->object.flags;
 221                         parents = parents->next;
 222                 }
 223         }
 224         return seen_commits;
 225 }
 226
 227 static void display_name(struct commit_name *n)
 228 {
 229         if (n->prio == 2 && !n->tag) {
 230                 n->tag = lookup_tag(n->sha1);
 231                 if (!n->tag || parse_tag(n->tag))
 232                         die("annotated tag %s not available", n->path);
 233         }
 234         if (n->tag && !n->name_checked) {
 235                 if (!n->tag->tag)
 236                         die("annotated tag %s has no embedded name", n->path);
 237                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 238                         warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
 239                 n->name_checked = 1;
 240         }
 241
 242         if (n->tag)
 243                 printf("%s", n->tag->tag);
 244         else
 245                 printf("%s", n->path);
 246 }
 247
 248 static void show_suffix(int depth, const unsigned char *sha1)
 249 {
 250         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 251 }
 252
 253 static void describe(const char *arg, int last_one)
 254 {
 255         unsigned char sha1[20];
 256         struct commit *cmit, *gave_up_on = NULL;
 257         struct commit_list *list;
 258         struct commit_name *n;
 259         struct possible_tag all_matches[MAX_TAGS];
 260         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 261         unsigned long seen_commits = 0;
 262         unsigned int unannotated_cnt = 0;
 263
 264         if (get_sha1(arg, sha1))
 265                 die("Not a valid object name %s", arg);
 266         cmit = lookup_commit_reference(sha1);
 267         if (!cmit)
 268                 die("%s is not a valid '%s' object", arg, commit_type);
 269
 270         n = find_commit_name(cmit->object.sha1);
 271         if (n && (tags || all || n->prio == 2)) {
 272                 /*
 273                  * Exact match to an existing ref.
 274                  */
 275                 display_name(n);
 276                 if (longformat)
 277                         show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 278                 if (dirty)
 279                         printf("%s", dirty);
 280                 printf("\n");
 281                 return;
 282         }
 283
 284         if (!max_candidates)
 285                 die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 286         if (debug)
 287                 fprintf(stderr, "searching to describe %s\n", arg);
 288
 289         list = NULL;
 290         cmit->object.flags = SEEN;
 291         commit_list_insert(cmit, &list);
 292         while (list) {
 293                 struct commit *c = pop_commit(&list);
 294                 struct commit_list *parents = c->parents;
 295                 seen_commits++;
 296                 n = c->util;
 297                 if (n) {
 298                         if (!tags && !all && n->prio < 2) {
 299                                 unannotated_cnt++;
 300                         } else if (match_cnt < max_candidates) {
 301                                 struct possible_tag *t = &all_matches[match_cnt++];
 302                                 t->name = n;
 303                                 t->depth = seen_commits - 1;
 304                                 t->flag_within = 1u << match_cnt;
 305                                 t->found_order = match_cnt;
 306                                 c->object.flags |= t->flag_within;
 307                                 if (n->prio == 2)
 308                                         annotated_cnt++;
 309                         }
 310                         else {
 311                                 gave_up_on = c;
 312                                 break;
 313                         }
 314                 }
 315                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 316                         struct possible_tag *t = &all_matches[cur_match];
 317                         if (!(c->object.flags & t->flag_within))
 318                                 t->depth++;
 319                 }
 320                 if (annotated_cnt && !list) {
 321                         if (debug)
 322                                 fprintf(stderr, "finished search at %s\n",
 323                                         sha1_to_hex(c->object.sha1));
 324                         break;
 325                 }
 326                 while (parents) {
 327                         struct commit *p = parents->item;
 328                         parse_commit(p);
 329                         if (!(p->object.flags & SEEN))
 330                                 insert_by_date(p, &list);
 331                         p->object.flags |= c->object.flags;
 332                         parents = parents->next;
 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                 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_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 397                 OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 398                 OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 399                 OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 400                 OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
 401                 OPT__ABBREV(&abbrev),
 402                 OPT_SET_INT(0, "exact-match", &max_candidates,
 403                             "only output exact matches", 0),
 404                 OPT_INTEGER(0, "candidates", &max_candidates,
 405                             "consider <n> most recent tags (default: 10)"),
 406                 OPT_STRING(0, "match",       &pattern, "pattern",
 407                            "only consider tags matching <pattern>"),
 408                 OPT_BOOLEAN(0, "always",     &always,
 409                            "show abbreviated commit object as fallback"),
 410                 {OPTION_STRING, 0, "dirty",  &dirty, "mark",
 411                            "append <mark> on dirty working tree (default: \"-dirty\")",
 412                  PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 413                 OPT_END(),
 414         };
 415
 416         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 417         if (max_candidates < 0)
 418                 max_candidates = 0;
 419         else if (max_candidates > MAX_TAGS)
 420                 max_candidates = MAX_TAGS;
 421
 422         save_commit_buffer = 0;
 423
 424         if (longformat && abbrev == 0)
 425                 die("--long is incompatible with --abbrev=0");
 426
 427         if (contains) {
 428                 const char **args = xmalloc((7 + argc) * sizeof(char *));
 429                 int i = 0;
 430                 args[i++] = "name-rev";
 431                 args[i++] = "--name-only";
 432                 args[i++] = "--no-undefined";
 433                 if (always)
 434                         args[i++] = "--always";
 435                 if (!all) {
 436                         args[i++] = "--tags";
 437                         if (pattern) {
 438                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 439                                 sprintf(s, "--refs=refs/tags/%s", pattern);
 440                                 args[i++] = s;
 441                         }
 442                 }
 443                 memcpy(args + i, argv, argc * sizeof(char *));
 444                 args[i + argc] = NULL;
 445                 return cmd_name_rev(i + argc, args, prefix);
 446         }
 447
 448         init_hash(&names);
 449         for_each_rawref(get_name, NULL);
 450         if (!names.nr && !always)
 451                 die("No names found, cannot describe anything.");
 452
 453         if (argc == 0) {
 454                 if (dirty && !cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1, diff_index_args, prefix))
 455                         dirty = NULL;
 456                 describe("HEAD", 1);
 457         } else if (dirty) {
 458                 die("--dirty is incompatible with committishes");
 459         } else {
 460                 while (argc-- > 0) {
 461                         describe(*argv++, argc == 0);
 462                 }
 463         }
 464         return 0;
 465 }