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         struct tag *tag;
  27         int prio; /* annotated tag = 2, tag = 1, head = 0 */
  28         unsigned char sha1[20];
  29         char path[FLEX_ARRAY]; /* more */
  30 };
  31 static const char *prio_names[] = {
  32         "head", "lightweight", "annotated",
  33 };
  34
  35 static void add_to_known_names(const char *path,
  36                                struct commit *commit,
  37                                int prio,
  38                                const unsigned char *sha1)
  39 {
  40         struct commit_name *e = commit->util;
  41         if (!e || e->prio < prio) {
  42                 size_t len = strlen(path)+1;
  43                 free(e);
  44                 e = xmalloc(sizeof(struct commit_name) + len);
  45                 e->tag = NULL;
  46                 e->prio = prio;
  47                 hashcpy(e->sha1, sha1);
  48                 memcpy(e->path, path, len);
  49                 commit->util = e;
  50         }
  51 }
  52
  53 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  54 {
  55         int might_be_tag = !prefixcmp(path, "refs/tags/");
  56         struct commit *commit;
  57         struct object *object;
  58         unsigned char peeled[20];
  59         int is_tag, prio;
  60
  61         if (!all && !might_be_tag)
  62                 return 0;
  63
  64         if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
  65                 commit = lookup_commit_reference_gently(peeled, 1);
  66                 if (!commit)
  67                         return 0;
  68                 is_tag = !!hashcmp(sha1, commit->object.sha1);
  69         } else {
  70                 commit = lookup_commit_reference_gently(sha1, 1);
  71                 object = parse_object(sha1);
  72                 if (!commit || !object)
  73                         return 0;
  74                 is_tag = object->type == OBJ_TAG;
  75         }
  76
  77         /* If --all, then any refs are used.
  78          * If --tags, then any tags are used.
  79          * Otherwise only annotated tags are used.
  80          */
  81         if (might_be_tag) {
  82                 if (is_tag) {
  83                         prio = 2;
  84                         if (pattern && fnmatch(pattern, path + 10, 0))
  85                                 prio = 0;
  86                 } else
  87                         prio = 1;
  88         }
  89         else
  90                 prio = 0;
  91
  92         if (!all) {
  93                 if (!prio)
  94                         return 0;
  95                 if (!tags && prio < 2)
  96                         return 0;
  97         }
  98         add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
  99         return 0;
 100 }
 101
 102 struct possible_tag {
 103         struct commit_name *name;
 104         int depth;
 105         int found_order;
 106         unsigned flag_within;
 107 };
 108
 109 static int compare_pt(const void *a_, const void *b_)
 110 {
 111         struct possible_tag *a = (struct possible_tag *)a_;
 112         struct possible_tag *b = (struct possible_tag *)b_;
 113         if (a->name->prio != b->name->prio)
 114                 return b->name->prio - a->name->prio;
 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 || !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         if (longformat)
 170                 printf("-0-g%s",
 171                        find_unique_abbrev(n->tag->tagged->sha1, abbrev));
 172 }
 173
 174 static void describe(const char *arg, int last_one)
 175 {
 176         unsigned char sha1[20];
 177         struct commit *cmit, *gave_up_on = NULL;
 178         struct commit_list *list;
 179         static int initialized = 0;
 180         struct commit_name *n;
 181         struct possible_tag all_matches[MAX_TAGS];
 182         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 183         unsigned long seen_commits = 0;
 184
 185         if (get_sha1(arg, sha1))
 186                 die("Not a valid object name %s", arg);
 187         cmit = lookup_commit_reference(sha1);
 188         if (!cmit)
 189                 die("%s is not a valid '%s' object", arg, commit_type);
 190
 191         if (!initialized) {
 192                 initialized = 1;
 193                 for_each_ref(get_name, NULL);
 194         }
 195
 196         n = cmit->util;
 197         if (n) {
 198                 display_name(n);
 199                 printf("\n");
 200                 return;
 201         }
 202
 203         if (!max_candidates)
 204                 die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 205         if (debug)
 206                 fprintf(stderr, "searching to describe %s\n", arg);
 207
 208         list = NULL;
 209         cmit->object.flags = SEEN;
 210         commit_list_insert(cmit, &list);
 211         while (list) {
 212                 struct commit *c = pop_commit(&list);
 213                 struct commit_list *parents = c->parents;
 214                 seen_commits++;
 215                 n = c->util;
 216                 if (n) {
 217                         if (match_cnt < max_candidates) {
 218                                 struct possible_tag *t = &all_matches[match_cnt++];
 219                                 t->name = n;
 220                                 t->depth = seen_commits - 1;
 221                                 t->flag_within = 1u << match_cnt;
 222                                 t->found_order = match_cnt;
 223                                 c->object.flags |= t->flag_within;
 224                                 if (n->prio == 2)
 225                                         annotated_cnt++;
 226                         }
 227                         else {
 228                                 gave_up_on = c;
 229                                 break;
 230                         }
 231                 }
 232                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 233                         struct possible_tag *t = &all_matches[cur_match];
 234                         if (!(c->object.flags & t->flag_within))
 235                                 t->depth++;
 236                 }
 237                 if (annotated_cnt && !list) {
 238                         if (debug)
 239                                 fprintf(stderr, "finished search at %s\n",
 240                                         sha1_to_hex(c->object.sha1));
 241                         break;
 242                 }
 243                 while (parents) {
 244                         struct commit *p = parents->item;
 245                         parse_commit(p);
 246                         if (!(p->object.flags & SEEN))
 247                                 insert_by_date(p, &list);
 248                         p->object.flags |= c->object.flags;
 249                         parents = parents->next;
 250                 }
 251         }
 252
 253         if (!match_cnt)
 254                 die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
 255
 256         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 257
 258         if (gave_up_on) {
 259                 insert_by_date(gave_up_on, &list);
 260                 seen_commits--;
 261         }
 262         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 263         free_commit_list(list);
 264
 265         if (debug) {
 266                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 267                         struct possible_tag *t = &all_matches[cur_match];
 268                         fprintf(stderr, " %-11s %8d %s\n",
 269                                 prio_names[t->name->prio],
 270                                 t->depth, t->name->path);
 271                 }
 272                 fprintf(stderr, "traversed %lu commits\n", seen_commits);
 273                 if (gave_up_on) {
 274                         fprintf(stderr,
 275                                 "more than %i tags found; listed %i most recent\n"
 276                                 "gave up search at %s\n",
 277                                 max_candidates, max_candidates,
 278                                 sha1_to_hex(gave_up_on->object.sha1));
 279                 }
 280         }
 281
 282         display_name(all_matches[0].name);
 283         if (abbrev)
 284                 printf("-%d-g%s", all_matches[0].depth,
 285                        find_unique_abbrev(cmit->object.sha1, abbrev));
 286         printf("\n");
 287
 288         if (!last_one)
 289                 clear_commit_marks(cmit, -1);
 290 }
 291
 292 int cmd_describe(int argc, const char **argv, const char *prefix)
 293 {
 294         int contains = 0;
 295         struct option options[] = {
 296                 OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 297                 OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 298                 OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 299                 OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 300                 OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
 301                 OPT__ABBREV(&abbrev),
 302                 OPT_SET_INT(0, "exact-match", &max_candidates,
 303                             "only output exact matches", 0),
 304                 OPT_INTEGER(0, "candidates", &max_candidates,
 305                             "consider <n> most recent tags (default: 10)"),
 306                 OPT_STRING(0, "match",       &pattern, "pattern",
 307                            "only consider tags matching <pattern>"),
 308                 OPT_END(),
 309         };
 310
 311         argc = parse_options(argc, argv, options, describe_usage, 0);
 312         if (max_candidates < 0)
 313                 max_candidates = 0;
 314         else if (max_candidates > MAX_TAGS)
 315                 max_candidates = MAX_TAGS;
 316
 317         save_commit_buffer = 0;
 318
 319         if (longformat && abbrev == 0)
 320                 die("--long is incompatible with --abbrev=0");
 321
 322         if (contains) {
 323                 const char **args = xmalloc((6 + argc) * sizeof(char*));
 324                 int i = 0;
 325                 args[i++] = "name-rev";
 326                 args[i++] = "--name-only";
 327                 args[i++] = "--no-undefined";
 328                 if (!all) {
 329                         args[i++] = "--tags";
 330                         if (pattern) {
 331                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 332                                 sprintf(s, "--refs=refs/tags/%s", pattern);
 333                                 args[i++] = s;
 334                         }
 335                 }
 336                 memcpy(args + i, argv, argc * sizeof(char*));
 337                 args[i + argc] = NULL;
 338                 return cmd_name_rev(i + argc, args, prefix);
 339         }
 340
 341         if (argc == 0) {
 342                 describe("HEAD", 1);
 343         } else {
 344                 while (argc-- > 0) {
 345                         describe(*argv++, argc == 0);
 346                 }
 347         }
 348         return 0;
 349 }