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 int have_util;
  28 static const char *pattern;
  29 static int always;
  30 static const char *dirty;
  31
  32 /* diff-index command arguments to check if working tree is dirty. */
  33 static const char *diff_index_args[] = {
  34         "diff-index", "--quiet", "HEAD", "--", NULL
  35 };
  36
  37
  38 struct commit_name {
  39         struct commit_name *next;
  40         unsigned char peeled[20];
  41         struct tag *tag;
  42         unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  43         unsigned name_checked:1;
  44         unsigned char sha1[20];
  45         const char *path;
  46 };
  47 static const char *prio_names[] = {
  48         "head", "lightweight", "annotated",
  49 };
  50
  51 static inline unsigned int hash_sha1(const unsigned char *sha1)
  52 {
  53         unsigned int hash;
  54         memcpy(&hash, sha1, sizeof(hash));
  55         return hash;
  56 }
  57
  58 static inline struct commit_name *find_commit_name(const unsigned char *peeled)
  59 {
  60         struct commit_name *n = lookup_hash(hash_sha1(peeled), &names);
  61         while (n && !!hashcmp(peeled, n->peeled))
  62                 n = n->next;
  63         return n;
  64 }
  65
  66 static int set_util(void *chain, void *data)
  67 {
  68         struct commit_name *n;
  69         for (n = chain; n; n = n->next) {
  70                 struct commit *c = lookup_commit_reference_gently(n->peeled, 1);
  71                 if (c)
  72                         c->util = n;
  73         }
  74         return 0;
  75 }
  76
  77 static int replace_name(struct commit_name *e,
  78                                int prio,
  79                                const unsigned char *sha1,
  80                                struct tag **tag)
  81 {
  82         if (!e || e->prio < prio)
  83                 return 1;
  84
  85         if (e->prio == 2 && prio == 2) {
  86                 /* Multiple annotated tags point to the same commit.
  87                  * Select one to keep based upon their tagger date.
  88                  */
  89                 struct tag *t;
  90
  91                 if (!e->tag) {
  92                         t = lookup_tag(e->sha1);
  93                         if (!t || parse_tag(t))
  94                                 return 1;
  95                         e->tag = t;
  96                 }
  97
  98                 t = lookup_tag(sha1);
  99                 if (!t || parse_tag(t))
 100                         return 0;
 101                 *tag = t;
 102
 103                 if (e->tag->date < t->date)
 104                         return 1;
 105         }
 106
 107         return 0;
 108 }
 109
 110 static void add_to_known_names(const char *path,
 111                                const unsigned char *peeled,
 112                                int prio,
 113                                const unsigned char *sha1)
 114 {
 115         struct commit_name *e = find_commit_name(peeled);
 116         struct tag *tag = NULL;
 117         if (replace_name(e, prio, sha1, &tag)) {
 118                 if (!e) {
 119                         void **pos;
 120                         e = xmalloc(sizeof(struct commit_name));
 121                         hashcpy(e->peeled, peeled);
 122                         pos = insert_hash(hash_sha1(peeled), e, &names);
 123                         if (pos) {
 124                                 e->next = *pos;
 125                                 *pos = e;
 126                         } else {
 127                                 e->next = NULL;
 128                         }
 129                 }
 130                 e->tag = tag;
 131                 e->prio = prio;
 132                 e->name_checked = 0;
 133                 hashcpy(e->sha1, sha1);
 134                 e->path = path;
 135         }
 136 }
 137
 138 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 139 {
 140         int might_be_tag = !prefixcmp(path, "refs/tags/");
 141         unsigned char peeled[20];
 142         int is_tag, prio;
 143
 144         if (!all && !might_be_tag)
 145                 return 0;
 146
 147         if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
 148                 is_tag = !!hashcmp(sha1, peeled);
 149         } else {
 150                 hashcpy(peeled, sha1);
 151                 is_tag = 0;
 152         }
 153
 154         /* If --all, then any refs are used.
 155          * If --tags, then any tags are used.
 156          * Otherwise only annotated tags are used.
 157          */
 158         if (might_be_tag) {
 159                 if (is_tag)
 160                         prio = 2;
 161                 else
 162                         prio = 1;
 163
 164                 if (pattern && fnmatch(pattern, path + 10, 0))
 165                         prio = 0;
 166         }
 167         else
 168                 prio = 0;
 169
 170         if (!all) {
 171                 if (!prio)
 172                         return 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         }
 342
 343         if (!match_cnt) {
 344                 const unsigned char *sha1 = cmit->object.sha1;
 345                 if (always) {
 346                         printf("%s", find_unique_abbrev(sha1, abbrev));
 347                         if (dirty)
 348                                 printf("%s", dirty);
 349                         printf("\n");
 350                         return;
 351                 }
 352                 if (unannotated_cnt)
 353                         die("No annotated tags can describe '%s'.\n"
 354                             "However, there were unannotated tags: try --tags.",
 355                             sha1_to_hex(sha1));
 356                 else
 357                         die("No tags can describe '%s'.\n"
 358                             "Try --always, or create some tags.",
 359                             sha1_to_hex(sha1));
 360         }
 361
 362         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 363
 364         if (gave_up_on) {
 365                 commit_list_insert_by_date(gave_up_on, &list);
 366                 seen_commits--;
 367         }
 368         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 369         free_commit_list(list);
 370
 371         if (debug) {
 372                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 373                         struct possible_tag *t = &all_matches[cur_match];
 374                         fprintf(stderr, " %-11s %8d %s\n",
 375                                 prio_names[t->name->prio],
 376                                 t->depth, t->name->path);
 377                 }
 378                 fprintf(stderr, "traversed %lu commits\n", seen_commits);
 379                 if (gave_up_on) {
 380                         fprintf(stderr,
 381                                 "more than %i tags found; listed %i most recent\n"
 382                                 "gave up search at %s\n",
 383                                 max_candidates, max_candidates,
 384                                 sha1_to_hex(gave_up_on->object.sha1));
 385                 }
 386         }
 387
 388         display_name(all_matches[0].name);
 389         if (abbrev)
 390                 show_suffix(all_matches[0].depth, cmit->object.sha1);
 391         if (dirty)
 392                 printf("%s", dirty);
 393         printf("\n");
 394
 395         if (!last_one)
 396                 clear_commit_marks(cmit, -1);
 397 }
 398
 399 int cmd_describe(int argc, const char **argv, const char *prefix)
 400 {
 401         int contains = 0;
 402         struct option options[] = {
 403                 OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 404                 OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 405                 OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 406                 OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 407                 OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
 408                 OPT__ABBREV(&abbrev),
 409                 OPT_SET_INT(0, "exact-match", &max_candidates,
 410                             "only output exact matches", 0),
 411                 OPT_INTEGER(0, "candidates", &max_candidates,
 412                             "consider <n> most recent tags (default: 10)"),
 413                 OPT_STRING(0, "match",       &pattern, "pattern",
 414                            "only consider tags matching <pattern>"),
 415                 OPT_BOOLEAN(0, "always",     &always,
 416                            "show abbreviated commit object as fallback"),
 417                 {OPTION_STRING, 0, "dirty",  &dirty, "mark",
 418                            "append <mark> on dirty working tree (default: \"-dirty\")",
 419                  PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 420                 OPT_END(),
 421         };
 422
 423         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 424         if (max_candidates < 0)
 425                 max_candidates = 0;
 426         else if (max_candidates > MAX_TAGS)
 427                 max_candidates = MAX_TAGS;
 428
 429         save_commit_buffer = 0;
 430
 431         if (longformat && abbrev == 0)
 432                 die("--long is incompatible with --abbrev=0");
 433
 434         if (contains) {
 435                 const char **args = xmalloc((7 + argc) * sizeof(char *));
 436                 int i = 0;
 437                 args[i++] = "name-rev";
 438                 args[i++] = "--name-only";
 439                 args[i++] = "--no-undefined";
 440                 if (always)
 441                         args[i++] = "--always";
 442                 if (!all) {
 443                         args[i++] = "--tags";
 444                         if (pattern) {
 445                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 446                                 sprintf(s, "--refs=refs/tags/%s", pattern);
 447                                 args[i++] = s;
 448                         }
 449                 }
 450                 memcpy(args + i, argv, argc * sizeof(char *));
 451                 args[i + argc] = NULL;
 452                 return cmd_name_rev(i + argc, args, prefix);
 453         }
 454
 455         init_hash(&names);
 456         for_each_rawref(get_name, NULL);
 457         if (!names.nr && !always)
 458                 die("No names found, cannot describe anything.");
 459
 460         if (argc == 0) {
 461                 if (dirty && !cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1, diff_index_args, prefix))
 462                         dirty = NULL;
 463                 describe("HEAD", 1);
 464         } else if (dirty) {
 465                 die("--dirty is incompatible with committishes");
 466         } else {
 467                 while (argc-- > 0) {
 468                         describe(*argv++, argc == 0);
 469                 }
 470         }
 471         return 0;
 472 }