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