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
  10 #define SEEN            (1u<<0)
  11 #define MAX_TAGS        (FLAG_BITS - 1)
  12
  13 static const char * const describe_usage[] = {
  14         "git describe [options] <committish>*",
  15         "git describe [options] --dirty",
  16         NULL
  17 };
  18
  19 static int debug;       /* Display lots of verbose info */
  20 static int all; /* Any valid ref can be used */
  21 static int tags;        /* Allow lightweight tags */
  22 static int longformat;
  23 static int abbrev = DEFAULT_ABBREV;
  24 static int max_candidates = 10;
  25 static int found_names;
  26 static const char *pattern;
  27 static int always;
  28 static const char *dirty;
  29
  30 /* diff-index command arguments to check if working tree is dirty. */
  31 static const char *diff_index_args[] = {
  32         "diff-index", "--quiet", "HEAD", "--", NULL
  33 };
  34
  35
  36 struct commit_name {
  37         struct tag *tag;
  38         unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  39         unsigned name_checked:1;
  40         unsigned char sha1[20];
  41         char path[FLEX_ARRAY]; /* more */
  42 };
  43 static const char *prio_names[] = {
  44         "head", "lightweight", "annotated",
  45 };
  46
  47 static int replace_name(struct commit_name *e,
  48                                int prio,
  49                                const unsigned char *sha1,
  50                                struct tag **tag)
  51 {
  52         if (!e || e->prio < prio)
  53                 return 1;
  54
  55         if (e->prio == 2 && prio == 2) {
  56                 /* Multiple annotated tags point to the same commit.
  57                  * Select one to keep based upon their tagger date.
  58                  */
  59                 struct tag *t;
  60
  61                 if (!e->tag) {
  62                         t = lookup_tag(e->sha1);
  63                         if (!t || parse_tag(t))
  64                                 return 1;
  65                         e->tag = t;
  66                 }
  67
  68                 t = lookup_tag(sha1);
  69                 if (!t || parse_tag(t))
  70                         return 0;
  71                 *tag = t;
  72
  73                 if (e->tag->date < t->date)
  74                         return 1;
  75         }
  76
  77         return 0;
  78 }
  79
  80 static void add_to_known_names(const char *path,
  81                                struct commit *commit,
  82                                int prio,
  83                                const unsigned char *sha1)
  84 {
  85         struct commit_name *e = commit->util;
  86         struct tag *tag = NULL;
  87         if (replace_name(e, prio, sha1, &tag)) {
  88                 size_t len = strlen(path)+1;
  89                 free(e);
  90                 e = xmalloc(sizeof(struct commit_name) + len);
  91                 e->tag = tag;
  92                 e->prio = prio;
  93                 e->name_checked = 0;
  94                 hashcpy(e->sha1, sha1);
  95                 memcpy(e->path, path, len);
  96                 commit->util = e;
  97         }
  98         found_names = 1;
  99 }
 100
 101 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 102 {
 103         int might_be_tag = !prefixcmp(path, "refs/tags/");
 104         struct commit *commit;
 105         struct object *object;
 106         unsigned char peeled[20];
 107         int is_tag, prio;
 108
 109         if (!all && !might_be_tag)
 110                 return 0;
 111
 112         if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
 113                 commit = lookup_commit_reference_gently(peeled, 1);
 114                 if (!commit)
 115                         return 0;
 116                 is_tag = !!hashcmp(sha1, commit->object.sha1);
 117         } else {
 118                 commit = lookup_commit_reference_gently(sha1, 1);
 119                 object = parse_object(sha1);
 120                 if (!commit || !object)
 121                         return 0;
 122                 is_tag = object->type == OBJ_TAG;
 123         }
 124
 125         /* If --all, then any refs are used.
 126          * If --tags, then any tags are used.
 127          * Otherwise only annotated tags are used.
 128          */
 129         if (might_be_tag) {
 130                 if (is_tag)
 131                         prio = 2;
 132                 else
 133                         prio = 1;
 134
 135                 if (pattern && fnmatch(pattern, path + 10, 0))
 136                         prio = 0;
 137         }
 138         else
 139                 prio = 0;
 140
 141         if (!all) {
 142                 if (!prio)
 143                         return 0;
 144         }
 145         add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
 146         return 0;
 147 }
 148
 149 struct possible_tag {
 150         struct commit_name *name;
 151         int depth;
 152         int found_order;
 153         unsigned flag_within;
 154 };
 155
 156 static int compare_pt(const void *a_, const void *b_)
 157 {
 158         struct possible_tag *a = (struct possible_tag *)a_;
 159         struct possible_tag *b = (struct possible_tag *)b_;
 160         if (a->depth != b->depth)
 161                 return a->depth - b->depth;
 162         if (a->found_order != b->found_order)
 163                 return a->found_order - b->found_order;
 164         return 0;
 165 }
 166
 167 static unsigned long finish_depth_computation(
 168         struct commit_list **list,
 169         struct possible_tag *best)
 170 {
 171         unsigned long seen_commits = 0;
 172         while (*list) {
 173                 struct commit *c = pop_commit(list);
 174                 struct commit_list *parents = c->parents;
 175                 seen_commits++;
 176                 if (c->object.flags & best->flag_within) {
 177                         struct commit_list *a = *list;
 178                         while (a) {
 179                                 struct commit *i = a->item;
 180                                 if (!(i->object.flags & best->flag_within))
 181                                         break;
 182                                 a = a->next;
 183                         }
 184                         if (!a)
 185                                 break;
 186                 } else
 187                         best->depth++;
 188                 while (parents) {
 189                         struct commit *p = parents->item;
 190                         parse_commit(p);
 191                         if (!(p->object.flags & SEEN))
 192                                 insert_by_date(p, list);
 193                         p->object.flags |= c->object.flags;
 194                         parents = parents->next;
 195                 }
 196         }
 197         return seen_commits;
 198 }
 199
 200 static void display_name(struct commit_name *n)
 201 {
 202         if (n->prio == 2 && !n->tag) {
 203                 n->tag = lookup_tag(n->sha1);
 204                 if (!n->tag || parse_tag(n->tag))
 205                         die("annotated tag %s not available", n->path);
 206         }
 207         if (n->tag && !n->name_checked) {
 208                 if (!n->tag->tag)
 209                         die("annotated tag %s has no embedded name", n->path);
 210                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 211                         warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
 212                 n->name_checked = 1;
 213         }
 214
 215         if (n->tag)
 216                 printf("%s", n->tag->tag);
 217         else
 218                 printf("%s", n->path);
 219 }
 220
 221 static void show_suffix(int depth, const unsigned char *sha1)
 222 {
 223         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 224 }
 225
 226 static void describe(const char *arg, int last_one)
 227 {
 228         unsigned char sha1[20];
 229         struct commit *cmit, *gave_up_on = NULL;
 230         struct commit_list *list;
 231         struct commit_name *n;
 232         struct possible_tag all_matches[MAX_TAGS];
 233         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 234         unsigned long seen_commits = 0;
 235         unsigned int unannotated_cnt = 0;
 236
 237         if (get_sha1(arg, sha1))
 238                 die("Not a valid object name %s", arg);
 239         cmit = lookup_commit_reference(sha1);
 240         if (!cmit)
 241                 die("%s is not a valid '%s' object", arg, commit_type);
 242
 243         n = cmit->util;
 244         if (n && (tags || all || n->prio == 2)) {
 245                 /*
 246                  * Exact match to an existing ref.
 247                  */
 248                 display_name(n);
 249                 if (longformat)
 250                         show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 251                 if (dirty)
 252                         printf("%s", dirty);
 253                 printf("\n");
 254                 return;
 255         }
 256
 257         if (!max_candidates)
 258                 die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 259         if (debug)
 260                 fprintf(stderr, "searching to describe %s\n", arg);
 261
 262         list = NULL;
 263         cmit->object.flags = SEEN;
 264         commit_list_insert(cmit, &list);
 265         while (list) {
 266                 struct commit *c = pop_commit(&list);
 267                 struct commit_list *parents = c->parents;
 268                 seen_commits++;
 269                 n = c->util;
 270                 if (n) {
 271                         if (!tags && !all && n->prio < 2) {
 272                                 unannotated_cnt++;
 273                         } else if (match_cnt < max_candidates) {
 274                                 struct possible_tag *t = &all_matches[match_cnt++];
 275                                 t->name = n;
 276                                 t->depth = seen_commits - 1;
 277                                 t->flag_within = 1u << match_cnt;
 278                                 t->found_order = match_cnt;
 279                                 c->object.flags |= t->flag_within;
 280                                 if (n->prio == 2)
 281                                         annotated_cnt++;
 282                         }
 283                         else {
 284                                 gave_up_on = c;
 285                                 break;
 286                         }
 287                 }
 288                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 289                         struct possible_tag *t = &all_matches[cur_match];
 290                         if (!(c->object.flags & t->flag_within))
 291                                 t->depth++;
 292                 }
 293                 if (annotated_cnt && !list) {
 294                         if (debug)
 295                                 fprintf(stderr, "finished search at %s\n",
 296                                         sha1_to_hex(c->object.sha1));
 297                         break;
 298                 }
 299                 while (parents) {
 300                         struct commit *p = parents->item;
 301                         parse_commit(p);
 302                         if (!(p->object.flags & SEEN))
 303                                 insert_by_date(p, &list);
 304                         p->object.flags |= c->object.flags;
 305                         parents = parents->next;
 306                 }
 307         }
 308
 309         if (!match_cnt) {
 310                 const unsigned char *sha1 = cmit->object.sha1;
 311                 if (always) {
 312                         printf("%s", find_unique_abbrev(sha1, abbrev));
 313                         if (dirty)
 314                                 printf("%s", dirty);
 315                         printf("\n");
 316                         return;
 317                 }
 318                 if (unannotated_cnt)
 319                         die("No annotated tags can describe '%s'.\n"
 320                             "However, there were unannotated tags: try --tags.",
 321                             sha1_to_hex(sha1));
 322                 else
 323                         die("No tags can describe '%s'.\n"
 324                             "Try --always, or create some tags.",
 325                             sha1_to_hex(sha1));
 326         }
 327
 328         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 329
 330         if (gave_up_on) {
 331                 insert_by_date(gave_up_on, &list);
 332                 seen_commits--;
 333         }
 334         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 335         free_commit_list(list);
 336
 337         if (debug) {
 338                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 339                         struct possible_tag *t = &all_matches[cur_match];
 340                         fprintf(stderr, " %-11s %8d %s\n",
 341                                 prio_names[t->name->prio],
 342                                 t->depth, t->name->path);
 343                 }
 344                 fprintf(stderr, "traversed %lu commits\n", seen_commits);
 345                 if (gave_up_on) {
 346                         fprintf(stderr,
 347                                 "more than %i tags found; listed %i most recent\n"
 348                                 "gave up search at %s\n",
 349                                 max_candidates, max_candidates,
 350                                 sha1_to_hex(gave_up_on->object.sha1));
 351                 }
 352         }
 353
 354         display_name(all_matches[0].name);
 355         if (abbrev)
 356                 show_suffix(all_matches[0].depth, cmit->object.sha1);
 357         if (dirty)
 358                 printf("%s", dirty);
 359         printf("\n");
 360
 361         if (!last_one)
 362                 clear_commit_marks(cmit, -1);
 363 }
 364
 365 int cmd_describe(int argc, const char **argv, const char *prefix)
 366 {
 367         int contains = 0;
 368         struct option options[] = {
 369                 OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 370                 OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 371                 OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 372                 OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 373                 OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
 374                 OPT__ABBREV(&abbrev),
 375                 OPT_SET_INT(0, "exact-match", &max_candidates,
 376                             "only output exact matches", 0),
 377                 OPT_INTEGER(0, "candidates", &max_candidates,
 378                             "consider <n> most recent tags (default: 10)"),
 379                 OPT_STRING(0, "match",       &pattern, "pattern",
 380                            "only consider tags matching <pattern>"),
 381                 OPT_BOOLEAN(0, "always",     &always,
 382                            "show abbreviated commit object as fallback"),
 383                 {OPTION_STRING, 0, "dirty",  &dirty, "mark",
 384                            "append <mark> on dirty working tree (default: \"-dirty\")",
 385                  PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 386                 OPT_END(),
 387         };
 388
 389         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 390         if (max_candidates < 0)
 391                 max_candidates = 0;
 392         else if (max_candidates > MAX_TAGS)
 393                 max_candidates = MAX_TAGS;
 394
 395         save_commit_buffer = 0;
 396
 397         if (longformat && abbrev == 0)
 398                 die("--long is incompatible with --abbrev=0");
 399
 400         if (contains) {
 401                 const char **args = xmalloc((7 + argc) * sizeof(char *));
 402                 int i = 0;
 403                 args[i++] = "name-rev";
 404                 args[i++] = "--name-only";
 405                 args[i++] = "--no-undefined";
 406                 if (always)
 407                         args[i++] = "--always";
 408                 if (!all) {
 409                         args[i++] = "--tags";
 410                         if (pattern) {
 411                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 412                                 sprintf(s, "--refs=refs/tags/%s", pattern);
 413                                 args[i++] = s;
 414                         }
 415                 }
 416                 memcpy(args + i, argv, argc * sizeof(char *));
 417                 args[i + argc] = NULL;
 418                 return cmd_name_rev(i + argc, args, prefix);
 419         }
 420
 421         for_each_ref(get_name, NULL);
 422         if (!found_names && !always)
 423                 die("No names found, cannot describe anything.");
 424
 425         if (argc == 0) {
 426                 if (dirty && !cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1, diff_index_args, prefix))
 427                         dirty = NULL;
 428                 describe("HEAD", 1);
 429         } else if (dirty) {
 430                 die("--dirty is incompatible with committishes");
 431         } else {
 432                 while (argc-- > 0) {
 433                         describe(*argv++, argc == 0);
 434                 }
 435         }
 436         return 0;
 437 }