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 abbrev = DEFAULT_ABBREV;
  21 static int max_candidates = 10;
  22 const char *pattern = NULL;
  23
  24 struct commit_name {
  25         int prio; /* annotated tag = 2, tag = 1, head = 0 */
  26         char path[FLEX_ARRAY]; /* more */
  27 };
  28 static const char *prio_names[] = {
  29         "head", "lightweight", "annotated",
  30 };
  31
  32 static void add_to_known_names(const char *path,
  33                                struct commit *commit,
  34                                int prio)
  35 {
  36         struct commit_name *e = commit->util;
  37         if (!e || e->prio < prio) {
  38                 size_t len = strlen(path)+1;
  39                 free(e);
  40                 e = xmalloc(sizeof(struct commit_name) + len);
  41                 e->prio = prio;
  42                 memcpy(e->path, path, len);
  43                 commit->util = e;
  44         }
  45 }
  46
  47 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  48 {
  49         int might_be_tag = !prefixcmp(path, "refs/tags/");
  50         struct commit *commit;
  51         struct object *object;
  52         unsigned char peeled[20];
  53         int is_tag, prio;
  54
  55         if (!all && !might_be_tag)
  56                 return 0;
  57
  58         if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
  59                 commit = lookup_commit_reference_gently(peeled, 1);
  60                 if (!commit)
  61                         return 0;
  62                 is_tag = !!hashcmp(sha1, commit->object.sha1);
  63         } else {
  64                 commit = lookup_commit_reference_gently(sha1, 1);
  65                 object = parse_object(sha1);
  66                 if (!commit || !object)
  67                         return 0;
  68                 is_tag = object->type == OBJ_TAG;
  69         }
  70
  71         /* If --all, then any refs are used.
  72          * If --tags, then any tags are used.
  73          * Otherwise only annotated tags are used.
  74          */
  75         if (might_be_tag) {
  76                 if (is_tag) {
  77                         prio = 2;
  78                         if (pattern && fnmatch(pattern, path + 10, 0))
  79                                 prio = 0;
  80                 } else
  81                         prio = 1;
  82         }
  83         else
  84                 prio = 0;
  85
  86         if (!all) {
  87                 if (!prio)
  88                         return 0;
  89                 if (!tags && prio < 2)
  90                         return 0;
  91         }
  92         add_to_known_names(all ? path + 5 : path + 10, commit, prio);
  93         return 0;
  94 }
  95
  96 struct possible_tag {
  97         struct commit_name *name;
  98         int depth;
  99         int found_order;
 100         unsigned flag_within;
 101 };
 102
 103 static int compare_pt(const void *a_, const void *b_)
 104 {
 105         struct possible_tag *a = (struct possible_tag *)a_;
 106         struct possible_tag *b = (struct possible_tag *)b_;
 107         if (a->name->prio != b->name->prio)
 108                 return b->name->prio - a->name->prio;
 109         if (a->depth != b->depth)
 110                 return a->depth - b->depth;
 111         if (a->found_order != b->found_order)
 112                 return a->found_order - b->found_order;
 113         return 0;
 114 }
 115
 116 static unsigned long finish_depth_computation(
 117         struct commit_list **list,
 118         struct possible_tag *best)
 119 {
 120         unsigned long seen_commits = 0;
 121         while (*list) {
 122                 struct commit *c = pop_commit(list);
 123                 struct commit_list *parents = c->parents;
 124                 seen_commits++;
 125                 if (c->object.flags & best->flag_within) {
 126                         struct commit_list *a = *list;
 127                         while (a) {
 128                                 struct commit *i = a->item;
 129                                 if (!(i->object.flags & best->flag_within))
 130                                         break;
 131                                 a = a->next;
 132                         }
 133                         if (!a)
 134                                 break;
 135                 } else
 136                         best->depth++;
 137                 while (parents) {
 138                         struct commit *p = parents->item;
 139                         parse_commit(p);
 140                         if (!(p->object.flags & SEEN))
 141                                 insert_by_date(p, list);
 142                         p->object.flags |= c->object.flags;
 143                         parents = parents->next;
 144                 }
 145         }
 146         return seen_commits;
 147 }
 148
 149 static void describe(const char *arg, int last_one)
 150 {
 151         unsigned char sha1[20];
 152         struct commit *cmit, *gave_up_on = NULL;
 153         struct commit_list *list;
 154         static int initialized = 0;
 155         struct commit_name *n;
 156         struct possible_tag all_matches[MAX_TAGS];
 157         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 158         unsigned long seen_commits = 0;
 159
 160         if (get_sha1(arg, sha1))
 161                 die("Not a valid object name %s", arg);
 162         cmit = lookup_commit_reference(sha1);
 163         if (!cmit)
 164                 die("%s is not a valid '%s' object", arg, commit_type);
 165
 166         if (!initialized) {
 167                 initialized = 1;
 168                 for_each_ref(get_name, NULL);
 169         }
 170
 171         n = cmit->util;
 172         if (n) {
 173                 printf("%s\n", n->path);
 174                 return;
 175         }
 176
 177         if (!max_candidates)
 178                 die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 179         if (debug)
 180                 fprintf(stderr, "searching to describe %s\n", arg);
 181
 182         list = NULL;
 183         cmit->object.flags = SEEN;
 184         commit_list_insert(cmit, &list);
 185         while (list) {
 186                 struct commit *c = pop_commit(&list);
 187                 struct commit_list *parents = c->parents;
 188                 seen_commits++;
 189                 n = c->util;
 190                 if (n) {
 191                         if (match_cnt < max_candidates) {
 192                                 struct possible_tag *t = &all_matches[match_cnt++];
 193                                 t->name = n;
 194                                 t->depth = seen_commits - 1;
 195                                 t->flag_within = 1u << match_cnt;
 196                                 t->found_order = match_cnt;
 197                                 c->object.flags |= t->flag_within;
 198                                 if (n->prio == 2)
 199                                         annotated_cnt++;
 200                         }
 201                         else {
 202                                 gave_up_on = c;
 203                                 break;
 204                         }
 205                 }
 206                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 207                         struct possible_tag *t = &all_matches[cur_match];
 208                         if (!(c->object.flags & t->flag_within))
 209                                 t->depth++;
 210                 }
 211                 if (annotated_cnt && !list) {
 212                         if (debug)
 213                                 fprintf(stderr, "finished search at %s\n",
 214                                         sha1_to_hex(c->object.sha1));
 215                         break;
 216                 }
 217                 while (parents) {
 218                         struct commit *p = parents->item;
 219                         parse_commit(p);
 220                         if (!(p->object.flags & SEEN))
 221                                 insert_by_date(p, &list);
 222                         p->object.flags |= c->object.flags;
 223                         parents = parents->next;
 224                 }
 225         }
 226
 227         if (!match_cnt)
 228                 die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
 229
 230         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 231
 232         if (gave_up_on) {
 233                 insert_by_date(gave_up_on, &list);
 234                 seen_commits--;
 235         }
 236         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 237         free_commit_list(list);
 238
 239         if (debug) {
 240                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 241                         struct possible_tag *t = &all_matches[cur_match];
 242                         fprintf(stderr, " %-11s %8d %s\n",
 243                                 prio_names[t->name->prio],
 244                                 t->depth, t->name->path);
 245                 }
 246                 fprintf(stderr, "traversed %lu commits\n", seen_commits);
 247                 if (gave_up_on) {
 248                         fprintf(stderr,
 249                                 "more than %i tags found; listed %i most recent\n"
 250                                 "gave up search at %s\n",
 251                                 max_candidates, max_candidates,
 252                                 sha1_to_hex(gave_up_on->object.sha1));
 253                 }
 254         }
 255         if (abbrev == 0)
 256                 printf("%s\n", all_matches[0].name->path );
 257         else
 258                 printf("%s-%d-g%s\n", all_matches[0].name->path,
 259                        all_matches[0].depth,
 260                        find_unique_abbrev(cmit->object.sha1, abbrev));
 261
 262         if (!last_one)
 263                 clear_commit_marks(cmit, -1);
 264 }
 265
 266 int cmd_describe(int argc, const char **argv, const char *prefix)
 267 {
 268         int contains = 0;
 269         struct option options[] = {
 270                 OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 271                 OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 272                 OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 273                 OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 274                 OPT__ABBREV(&abbrev),
 275                 OPT_SET_INT(0, "exact-match", &max_candidates,
 276                             "only output exact matches", 0),
 277                 OPT_INTEGER(0, "candidates", &max_candidates,
 278                             "consider <n> most recent tags (default: 10)"),
 279                 OPT_STRING(0, "match",       &pattern, "pattern",
 280                            "only consider tags matching <pattern>"),
 281                 OPT_END(),
 282         };
 283
 284         argc = parse_options(argc, argv, options, describe_usage, 0);
 285         if (max_candidates < 0)
 286                 max_candidates = 0;
 287         else if (max_candidates > MAX_TAGS)
 288                 max_candidates = MAX_TAGS;
 289
 290         save_commit_buffer = 0;
 291
 292         if (contains) {
 293                 const char **args = xmalloc((6 + argc) * sizeof(char*));
 294                 int i = 0;
 295                 args[i++] = "name-rev";
 296                 args[i++] = "--name-only";
 297                 args[i++] = "--no-undefined";
 298                 if (!all) {
 299                         args[i++] = "--tags";
 300                         if (pattern) {
 301                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 302                                 sprintf(s, "--refs=refs/tags/%s", pattern);
 303                                 args[i++] = s;
 304                         }
 305                 }
 306                 memcpy(args + i, argv, argc * sizeof(char*));
 307                 args[i + argc] = NULL;
 308                 return cmd_name_rev(i + argc, args, prefix);
 309         }
 310
 311         if (argc == 0) {
 312                 describe("HEAD", 1);
 313         } else {
 314                 while (argc-- > 0) {
 315                         describe(*argv++, argc == 0);
 316                 }
 317         }
 318         return 0;
 319 }