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
  25 struct commit_name {
  26         int prio; /* annotated tag = 2, tag = 1, head = 0 */
  27         char path[FLEX_ARRAY]; /* more */
  28 };
  29 static const char *prio_names[] = {
  30         "head", "lightweight", "annotated",
  31 };
  32
  33 static void add_to_known_names(const char *path,
  34                                struct commit *commit,
  35                                int prio)
  36 {
  37         struct commit_name *e = commit->util;
  38         if (!e || e->prio < prio) {
  39                 size_t len = strlen(path)+1;
  40                 free(e);
  41                 e = xmalloc(sizeof(struct commit_name) + len);
  42                 e->prio = prio;
  43                 memcpy(e->path, path, len);
  44                 commit->util = e;
  45         }
  46 }
  47
  48 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  49 {
  50         int might_be_tag = !prefixcmp(path, "refs/tags/");
  51         struct commit *commit;
  52         struct object *object;
  53         unsigned char peeled[20];
  54         int is_tag, prio;
  55
  56         if (!all && !might_be_tag)
  57                 return 0;
  58
  59         if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
  60                 commit = lookup_commit_reference_gently(peeled, 1);
  61                 if (!commit)
  62                         return 0;
  63                 is_tag = !!hashcmp(sha1, commit->object.sha1);
  64         } else {
  65                 commit = lookup_commit_reference_gently(sha1, 1);
  66                 object = parse_object(sha1);
  67                 if (!commit || !object)
  68                         return 0;
  69                 is_tag = object->type == OBJ_TAG;
  70         }
  71
  72         /* If --all, then any refs are used.
  73          * If --tags, then any tags are used.
  74          * Otherwise only annotated tags are used.
  75          */
  76         if (might_be_tag) {
  77                 if (is_tag) {
  78                         prio = 2;
  79                         if (pattern && fnmatch(pattern, path + 10, 0))
  80                                 prio = 0;
  81                 } else
  82                         prio = 1;
  83         }
  84         else
  85                 prio = 0;
  86
  87         if (!all) {
  88                 if (!prio)
  89                         return 0;
  90                 if (!tags && prio < 2)
  91                         return 0;
  92         }
  93         add_to_known_names(all ? path + 5 : path + 10, commit, prio);
  94         return 0;
  95 }
  96
  97 struct possible_tag {
  98         struct commit_name *name;
  99         int depth;
 100         int found_order;
 101         unsigned flag_within;
 102 };
 103
 104 static int compare_pt(const void *a_, const void *b_)
 105 {
 106         struct possible_tag *a = (struct possible_tag *)a_;
 107         struct possible_tag *b = (struct possible_tag *)b_;
 108         if (a->name->prio != b->name->prio)
 109                 return b->name->prio - a->name->prio;
 110         if (a->depth != b->depth)
 111                 return a->depth - b->depth;
 112         if (a->found_order != b->found_order)
 113                 return a->found_order - b->found_order;
 114         return 0;
 115 }
 116
 117 static unsigned long finish_depth_computation(
 118         struct commit_list **list,
 119         struct possible_tag *best)
 120 {
 121         unsigned long seen_commits = 0;
 122         while (*list) {
 123                 struct commit *c = pop_commit(list);
 124                 struct commit_list *parents = c->parents;
 125                 seen_commits++;
 126                 if (c->object.flags & best->flag_within) {
 127                         struct commit_list *a = *list;
 128                         while (a) {
 129                                 struct commit *i = a->item;
 130                                 if (!(i->object.flags & best->flag_within))
 131                                         break;
 132                                 a = a->next;
 133                         }
 134                         if (!a)
 135                                 break;
 136                 } else
 137                         best->depth++;
 138                 while (parents) {
 139                         struct commit *p = parents->item;
 140                         parse_commit(p);
 141                         if (!(p->object.flags & SEEN))
 142                                 insert_by_date(p, list);
 143                         p->object.flags |= c->object.flags;
 144                         parents = parents->next;
 145                 }
 146         }
 147         return seen_commits;
 148 }
 149
 150 static void describe(const char *arg, int last_one)
 151 {
 152         unsigned char sha1[20];
 153         struct commit *cmit, *gave_up_on = NULL;
 154         struct commit_list *list;
 155         static int initialized = 0;
 156         struct commit_name *n;
 157         struct possible_tag all_matches[MAX_TAGS];
 158         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 159         unsigned long seen_commits = 0;
 160
 161         if (get_sha1(arg, sha1))
 162                 die("Not a valid object name %s", arg);
 163         cmit = lookup_commit_reference(sha1);
 164         if (!cmit)
 165                 die("%s is not a valid '%s' object", arg, commit_type);
 166
 167         if (!initialized) {
 168                 initialized = 1;
 169                 for_each_ref(get_name, NULL);
 170         }
 171
 172         n = cmit->util;
 173         if (n) {
 174                 if (!longformat)
 175                         printf("%s\n", n->path);
 176                 else
 177                         printf("%s-0-g%s\n", n->path,
 178                                 find_unique_abbrev(cmit->object.sha1, abbrev));
 179                 return;
 180         }
 181
 182         if (!max_candidates)
 183                 die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 184         if (debug)
 185                 fprintf(stderr, "searching to describe %s\n", arg);
 186
 187         list = NULL;
 188         cmit->object.flags = SEEN;
 189         commit_list_insert(cmit, &list);
 190         while (list) {
 191                 struct commit *c = pop_commit(&list);
 192                 struct commit_list *parents = c->parents;
 193                 seen_commits++;
 194                 n = c->util;
 195                 if (n) {
 196                         if (match_cnt < max_candidates) {
 197                                 struct possible_tag *t = &all_matches[match_cnt++];
 198                                 t->name = n;
 199                                 t->depth = seen_commits - 1;
 200                                 t->flag_within = 1u << match_cnt;
 201                                 t->found_order = match_cnt;
 202                                 c->object.flags |= t->flag_within;
 203                                 if (n->prio == 2)
 204                                         annotated_cnt++;
 205                         }
 206                         else {
 207                                 gave_up_on = c;
 208                                 break;
 209                         }
 210                 }
 211                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 212                         struct possible_tag *t = &all_matches[cur_match];
 213                         if (!(c->object.flags & t->flag_within))
 214                                 t->depth++;
 215                 }
 216                 if (annotated_cnt && !list) {
 217                         if (debug)
 218                                 fprintf(stderr, "finished search at %s\n",
 219                                         sha1_to_hex(c->object.sha1));
 220                         break;
 221                 }
 222                 while (parents) {
 223                         struct commit *p = parents->item;
 224                         parse_commit(p);
 225                         if (!(p->object.flags & SEEN))
 226                                 insert_by_date(p, &list);
 227                         p->object.flags |= c->object.flags;
 228                         parents = parents->next;
 229                 }
 230         }
 231
 232         if (!match_cnt)
 233                 die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
 234
 235         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 236
 237         if (gave_up_on) {
 238                 insert_by_date(gave_up_on, &list);
 239                 seen_commits--;
 240         }
 241         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 242         free_commit_list(list);
 243
 244         if (debug) {
 245                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 246                         struct possible_tag *t = &all_matches[cur_match];
 247                         fprintf(stderr, " %-11s %8d %s\n",
 248                                 prio_names[t->name->prio],
 249                                 t->depth, t->name->path);
 250                 }
 251                 fprintf(stderr, "traversed %lu commits\n", seen_commits);
 252                 if (gave_up_on) {
 253                         fprintf(stderr,
 254                                 "more than %i tags found; listed %i most recent\n"
 255                                 "gave up search at %s\n",
 256                                 max_candidates, max_candidates,
 257                                 sha1_to_hex(gave_up_on->object.sha1));
 258                 }
 259         }
 260         if (abbrev == 0)
 261                 printf("%s\n", all_matches[0].name->path );
 262         else
 263                 printf("%s-%d-g%s\n", all_matches[0].name->path,
 264                        all_matches[0].depth,
 265                        find_unique_abbrev(cmit->object.sha1, abbrev));
 266
 267         if (!last_one)
 268                 clear_commit_marks(cmit, -1);
 269 }
 270
 271 int cmd_describe(int argc, const char **argv, const char *prefix)
 272 {
 273         int contains = 0;
 274         struct option options[] = {
 275                 OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 276                 OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 277                 OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 278                 OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 279                 OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
 280                 OPT__ABBREV(&abbrev),
 281                 OPT_SET_INT(0, "exact-match", &max_candidates,
 282                             "only output exact matches", 0),
 283                 OPT_INTEGER(0, "candidates", &max_candidates,
 284                             "consider <n> most recent tags (default: 10)"),
 285                 OPT_STRING(0, "match",       &pattern, "pattern",
 286                            "only consider tags matching <pattern>"),
 287                 OPT_END(),
 288         };
 289
 290         argc = parse_options(argc, argv, options, describe_usage, 0);
 291         if (max_candidates < 0)
 292                 max_candidates = 0;
 293         else if (max_candidates > MAX_TAGS)
 294                 max_candidates = MAX_TAGS;
 295
 296         save_commit_buffer = 0;
 297
 298         if (longformat && abbrev == 0)
 299                 die("--long is incompatible with --abbrev=0");
 300
 301         if (contains) {
 302                 const char **args = xmalloc((6 + argc) * sizeof(char*));
 303                 int i = 0;
 304                 args[i++] = "name-rev";
 305                 args[i++] = "--name-only";
 306                 args[i++] = "--no-undefined";
 307                 if (!all) {
 308                         args[i++] = "--tags";
 309                         if (pattern) {
 310                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 311                                 sprintf(s, "--refs=refs/tags/%s", pattern);
 312                                 args[i++] = s;
 313                         }
 314                 }
 315                 memcpy(args + i, argv, argc * sizeof(char*));
 316                 args[i + argc] = NULL;
 317                 return cmd_name_rev(i + argc, args, prefix);
 318         }
 319
 320         if (argc == 0) {
 321                 describe("HEAD", 1);
 322         } else {
 323                 while (argc-- > 0) {
 324                         describe(*argv++, argc == 0);
 325                 }
 326         }
 327         return 0;
 328 }