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