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