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                 else
  86                         prio = 1;
  87
  88                 if (pattern && fnmatch(pattern, path + 10, 0))
  89                         prio = 0;
  90         }
  91         else
  92                 prio = 0;
  93
  94         if (!all) {
  95                 if (!prio)
  96                         return 0;
  97                 if (!tags && prio < 2)
  98                         return 0;
  99         }
 100         add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
 101         return 0;
 102 }
 103
 104 struct possible_tag {
 105         struct commit_name *name;
 106         int depth;
 107         int found_order;
 108         unsigned flag_within;
 109 };
 110
 111 static int compare_pt(const void *a_, const void *b_)
 112 {
 113         struct possible_tag *a = (struct possible_tag *)a_;
 114         struct possible_tag *b = (struct possible_tag *)b_;
 115         if (a->name->prio != b->name->prio)
 116                 return b->name->prio - a->name->prio;
 117         if (a->depth != b->depth)
 118                 return a->depth - b->depth;
 119         if (a->found_order != b->found_order)
 120                 return a->found_order - b->found_order;
 121         return 0;
 122 }
 123
 124 static unsigned long finish_depth_computation(
 125         struct commit_list **list,
 126         struct possible_tag *best)
 127 {
 128         unsigned long seen_commits = 0;
 129         while (*list) {
 130                 struct commit *c = pop_commit(list);
 131                 struct commit_list *parents = c->parents;
 132                 seen_commits++;
 133                 if (c->object.flags & best->flag_within) {
 134                         struct commit_list *a = *list;
 135                         while (a) {
 136                                 struct commit *i = a->item;
 137                                 if (!(i->object.flags & best->flag_within))
 138                                         break;
 139                                 a = a->next;
 140                         }
 141                         if (!a)
 142                                 break;
 143                 } else
 144                         best->depth++;
 145                 while (parents) {
 146                         struct commit *p = parents->item;
 147                         parse_commit(p);
 148                         if (!(p->object.flags & SEEN))
 149                                 insert_by_date(p, list);
 150                         p->object.flags |= c->object.flags;
 151                         parents = parents->next;
 152                 }
 153         }
 154         return seen_commits;
 155 }
 156
 157 static void display_name(struct commit_name *n)
 158 {
 159         if (n->prio == 2 && !n->tag) {
 160                 n->tag = lookup_tag(n->sha1);
 161                 if (!n->tag || parse_tag(n->tag) || !n->tag->tag)
 162                         die("annotated tag %s not available", n->path);
 163                 if (strcmp(n->tag->tag, n->path))
 164                         warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
 165         }
 166
 167         if (n->tag)
 168                 printf("%s", n->tag->tag);
 169         else
 170                 printf("%s", n->path);
 171 }
 172
 173 static void show_suffix(int depth, const unsigned char *sha1)
 174 {
 175         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 176 }
 177
 178 static void describe(const char *arg, int last_one)
 179 {
 180         unsigned char sha1[20];
 181         struct commit *cmit, *gave_up_on = NULL;
 182         struct commit_list *list;
 183         static int initialized = 0;
 184         struct commit_name *n;
 185         struct possible_tag all_matches[MAX_TAGS];
 186         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 187         unsigned long seen_commits = 0;
 188
 189         if (get_sha1(arg, sha1))
 190                 die("Not a valid object name %s", arg);
 191         cmit = lookup_commit_reference(sha1);
 192         if (!cmit)
 193                 die("%s is not a valid '%s' object", arg, commit_type);
 194
 195         if (!initialized) {
 196                 initialized = 1;
 197                 for_each_ref(get_name, NULL);
 198         }
 199
 200         n = cmit->util;
 201         if (n) {
 202                 /*
 203                  * Exact match to an existing ref.
 204                  */
 205                 display_name(n);
 206                 if (longformat)
 207                         show_suffix(0, n->tag->tagged->sha1);
 208                 printf("\n");
 209                 return;
 210         }
 211
 212         if (!max_candidates)
 213                 die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 214         if (debug)
 215                 fprintf(stderr, "searching to describe %s\n", arg);
 216
 217         list = NULL;
 218         cmit->object.flags = SEEN;
 219         commit_list_insert(cmit, &list);
 220         while (list) {
 221                 struct commit *c = pop_commit(&list);
 222                 struct commit_list *parents = c->parents;
 223                 seen_commits++;
 224                 n = c->util;
 225                 if (n) {
 226                         if (match_cnt < max_candidates) {
 227                                 struct possible_tag *t = &all_matches[match_cnt++];
 228                                 t->name = n;
 229                                 t->depth = seen_commits - 1;
 230                                 t->flag_within = 1u << match_cnt;
 231                                 t->found_order = match_cnt;
 232                                 c->object.flags |= t->flag_within;
 233                                 if (n->prio == 2)
 234                                         annotated_cnt++;
 235                         }
 236                         else {
 237                                 gave_up_on = c;
 238                                 break;
 239                         }
 240                 }
 241                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 242                         struct possible_tag *t = &all_matches[cur_match];
 243                         if (!(c->object.flags & t->flag_within))
 244                                 t->depth++;
 245                 }
 246                 if (annotated_cnt && !list) {
 247                         if (debug)
 248                                 fprintf(stderr, "finished search at %s\n",
 249                                         sha1_to_hex(c->object.sha1));
 250                         break;
 251                 }
 252                 while (parents) {
 253                         struct commit *p = parents->item;
 254                         parse_commit(p);
 255                         if (!(p->object.flags & SEEN))
 256                                 insert_by_date(p, &list);
 257                         p->object.flags |= c->object.flags;
 258                         parents = parents->next;
 259                 }
 260         }
 261
 262         if (!match_cnt) {
 263                 const unsigned char *sha1 = cmit->object.sha1;
 264                 if (always) {
 265                         printf("%s\n", find_unique_abbrev(sha1, abbrev));
 266                         return;
 267                 }
 268                 die("cannot describe '%s'", sha1_to_hex(sha1));
 269         }
 270
 271         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 272
 273         if (gave_up_on) {
 274                 insert_by_date(gave_up_on, &list);
 275                 seen_commits--;
 276         }
 277         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 278         free_commit_list(list);
 279
 280         if (debug) {
 281                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 282                         struct possible_tag *t = &all_matches[cur_match];
 283                         fprintf(stderr, " %-11s %8d %s\n",
 284                                 prio_names[t->name->prio],
 285                                 t->depth, t->name->path);
 286                 }
 287                 fprintf(stderr, "traversed %lu commits\n", seen_commits);
 288                 if (gave_up_on) {
 289                         fprintf(stderr,
 290                                 "more than %i tags found; listed %i most recent\n"
 291                                 "gave up search at %s\n",
 292                                 max_candidates, max_candidates,
 293                                 sha1_to_hex(gave_up_on->object.sha1));
 294                 }
 295         }
 296
 297         display_name(all_matches[0].name);
 298         if (abbrev)
 299                 show_suffix(all_matches[0].depth, cmit->object.sha1);
 300         printf("\n");
 301
 302         if (!last_one)
 303                 clear_commit_marks(cmit, -1);
 304 }
 305
 306 int cmd_describe(int argc, const char **argv, const char *prefix)
 307 {
 308         int contains = 0;
 309         struct option options[] = {
 310                 OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 311                 OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 312                 OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 313                 OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 314                 OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
 315                 OPT__ABBREV(&abbrev),
 316                 OPT_SET_INT(0, "exact-match", &max_candidates,
 317                             "only output exact matches", 0),
 318                 OPT_INTEGER(0, "candidates", &max_candidates,
 319                             "consider <n> most recent tags (default: 10)"),
 320                 OPT_STRING(0, "match",       &pattern, "pattern",
 321                            "only consider tags matching <pattern>"),
 322                 OPT_BOOLEAN(0, "always",     &always,
 323                            "show abbreviated commit object as fallback"),
 324                 OPT_END(),
 325         };
 326
 327         argc = parse_options(argc, argv, options, describe_usage, 0);
 328         if (max_candidates < 0)
 329                 max_candidates = 0;
 330         else if (max_candidates > MAX_TAGS)
 331                 max_candidates = MAX_TAGS;
 332
 333         save_commit_buffer = 0;
 334
 335         if (longformat && abbrev == 0)
 336                 die("--long is incompatible with --abbrev=0");
 337
 338         if (contains) {
 339                 const char **args = xmalloc((7 + argc) * sizeof(char*));
 340                 int i = 0;
 341                 args[i++] = "name-rev";
 342                 args[i++] = "--name-only";
 343                 args[i++] = "--no-undefined";
 344                 if (always)
 345                         args[i++] = "--always";
 346                 if (!all) {
 347                         args[i++] = "--tags";
 348                         if (pattern) {
 349                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 350                                 sprintf(s, "--refs=refs/tags/%s", pattern);
 351                                 args[i++] = s;
 352                         }
 353                 }
 354                 memcpy(args + i, argv, argc * sizeof(char*));
 355                 args[i + argc] = NULL;
 356                 return cmd_name_rev(i + argc, args, prefix);
 357         }
 358
 359         if (argc == 0) {
 360                 describe("HEAD", 1);
 361         } else {
 362                 while (argc-- > 0) {
 363                         describe(*argv++, argc == 0);
 364                 }
 365         }
 366         return 0;
 367 }