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