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