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 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                         if (pattern && fnmatch(pattern, path + 10, 0))
  86                                 prio = 0;
  87                 } else
  88                         prio = 1;
  89         }
  90         else
  91                 prio = 0;
  92
  93         if (!all) {
  94                 if (!prio)
  95                         return 0;
  96                 if (!tags && prio < 2)
  97                         return 0;
  98         }
  99         add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
 100         return 0;
 101 }
 102
 103 struct possible_tag {
 104         struct commit_name *name;
 105         int depth;
 106         int found_order;
 107         unsigned flag_within;
 108 };
 109
 110 static int compare_pt(const void *a_, const void *b_)
 111 {
 112         struct possible_tag *a = (struct possible_tag *)a_;
 113         struct possible_tag *b = (struct possible_tag *)b_;
 114         if (a->name->prio != b->name->prio)
 115                 return b->name->prio - a->name->prio;
 116         if (a->depth != b->depth)
 117                 return a->depth - b->depth;
 118         if (a->found_order != b->found_order)
 119                 return a->found_order - b->found_order;
 120         return 0;
 121 }
 122
 123 static unsigned long finish_depth_computation(
 124         struct commit_list **list,
 125         struct possible_tag *best)
 126 {
 127         unsigned long seen_commits = 0;
 128         while (*list) {
 129                 struct commit *c = pop_commit(list);
 130                 struct commit_list *parents = c->parents;
 131                 seen_commits++;
 132                 if (c->object.flags & best->flag_within) {
 133                         struct commit_list *a = *list;
 134                         while (a) {
 135                                 struct commit *i = a->item;
 136                                 if (!(i->object.flags & best->flag_within))
 137                                         break;
 138                                 a = a->next;
 139                         }
 140                         if (!a)
 141                                 break;
 142                 } else
 143                         best->depth++;
 144                 while (parents) {
 145                         struct commit *p = parents->item;
 146                         parse_commit(p);
 147                         if (!(p->object.flags & SEEN))
 148                                 insert_by_date(p, list);
 149                         p->object.flags |= c->object.flags;
 150                         parents = parents->next;
 151                 }
 152         }
 153         return seen_commits;
 154 }
 155
 156 static void display_name(struct commit_name *n)
 157 {
 158         if (n->prio == 2 && !n->tag) {
 159                 n->tag = lookup_tag(n->sha1);
 160                 if (!n->tag || parse_tag(n->tag) || !n->tag->tag)
 161                         die("annotated tag %s not available", n->path);
 162                 if (strcmp(n->tag->tag, n->path))
 163                         warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
 164         }
 165
 166         if (n->tag)
 167                 printf("%s", n->tag->tag);
 168         else
 169                 printf("%s", n->path);
 170 }
 171
 172 static void show_suffix(int depth, const unsigned char *sha1)
 173 {
 174         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 175 }
 176
 177 static void describe(const char *arg, int last_one)
 178 {
 179         unsigned char sha1[20];
 180         struct commit *cmit, *gave_up_on = NULL;
 181         struct commit_list *list;
 182         static int initialized = 0;
 183         struct commit_name *n;
 184         struct possible_tag all_matches[MAX_TAGS];
 185         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 186         unsigned long seen_commits = 0;
 187
 188         if (get_sha1(arg, sha1))
 189                 die("Not a valid object name %s", arg);
 190         cmit = lookup_commit_reference(sha1);
 191         if (!cmit)
 192                 die("%s is not a valid '%s' object", arg, commit_type);
 193
 194         if (!initialized) {
 195                 initialized = 1;
 196                 for_each_ref(get_name, NULL);
 197         }
 198
 199         n = cmit->util;
 200         if (n) {
 201                 /*
 202                  * Exact match to an existing ref.
 203                  */
 204                 display_name(n);
 205                 if (longformat)
 206                         show_suffix(0, n->tag->tagged->sha1);
 207                 printf("\n");
 208                 return;
 209         }
 210
 211         if (!max_candidates)
 212                 die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 213         if (debug)
 214                 fprintf(stderr, "searching to describe %s\n", arg);
 215
 216         list = NULL;
 217         cmit->object.flags = SEEN;
 218         commit_list_insert(cmit, &list);
 219         while (list) {
 220                 struct commit *c = pop_commit(&list);
 221                 struct commit_list *parents = c->parents;
 222                 seen_commits++;
 223                 n = c->util;
 224                 if (n) {
 225                         if (match_cnt < max_candidates) {
 226                                 struct possible_tag *t = &all_matches[match_cnt++];
 227                                 t->name = n;
 228                                 t->depth = seen_commits - 1;
 229                                 t->flag_within = 1u << match_cnt;
 230                                 t->found_order = match_cnt;
 231                                 c->object.flags |= t->flag_within;
 232                                 if (n->prio == 2)
 233                                         annotated_cnt++;
 234                         }
 235                         else {
 236                                 gave_up_on = c;
 237                                 break;
 238                         }
 239                 }
 240                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 241                         struct possible_tag *t = &all_matches[cur_match];
 242                         if (!(c->object.flags & t->flag_within))
 243                                 t->depth++;
 244                 }
 245                 if (annotated_cnt && !list) {
 246                         if (debug)
 247                                 fprintf(stderr, "finished search at %s\n",
 248                                         sha1_to_hex(c->object.sha1));
 249                         break;
 250                 }
 251                 while (parents) {
 252                         struct commit *p = parents->item;
 253                         parse_commit(p);
 254                         if (!(p->object.flags & SEEN))
 255                                 insert_by_date(p, &list);
 256                         p->object.flags |= c->object.flags;
 257                         parents = parents->next;
 258                 }
 259         }
 260
 261         if (!match_cnt) {
 262                 const unsigned char *sha1 = cmit->object.sha1;
 263                 if (always) {
 264                         printf("%s\n", find_unique_abbrev(sha1, abbrev));
 265                         return;
 266                 }
 267                 die("cannot describe '%s'", sha1_to_hex(sha1));
 268         }
 269
 270         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 271
 272         if (gave_up_on) {
 273                 insert_by_date(gave_up_on, &list);
 274                 seen_commits--;
 275         }
 276         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 277         free_commit_list(list);
 278
 279         if (debug) {
 280                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 281                         struct possible_tag *t = &all_matches[cur_match];
 282                         fprintf(stderr, " %-11s %8d %s\n",
 283                                 prio_names[t->name->prio],
 284                                 t->depth, t->name->path);
 285                 }
 286                 fprintf(stderr, "traversed %lu commits\n", seen_commits);
 287                 if (gave_up_on) {
 288                         fprintf(stderr,
 289                                 "more than %i tags found; listed %i most recent\n"
 290                                 "gave up search at %s\n",
 291                                 max_candidates, max_candidates,
 292                                 sha1_to_hex(gave_up_on->object.sha1));
 293                 }
 294         }
 295
 296         display_name(all_matches[0].name);
 297         if (abbrev)
 298                 show_suffix(all_matches[0].depth, cmit->object.sha1);
 299         printf("\n");
 300
 301         if (!last_one)
 302                 clear_commit_marks(cmit, -1);
 303 }
 304
 305 int cmd_describe(int argc, const char **argv, const char *prefix)
 306 {
 307         int contains = 0;
 308         struct option options[] = {
 309                 OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 310                 OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 311                 OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 312                 OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 313                 OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
 314                 OPT__ABBREV(&abbrev),
 315                 OPT_SET_INT(0, "exact-match", &max_candidates,
 316                             "only output exact matches", 0),
 317                 OPT_INTEGER(0, "candidates", &max_candidates,
 318                             "consider <n> most recent tags (default: 10)"),
 319                 OPT_STRING(0, "match",       &pattern, "pattern",
 320                            "only consider tags matching <pattern>"),
 321                 OPT_BOOLEAN(0, "always",     &always,
 322                            "show abbreviated commit object as fallback"),
 323                 OPT_END(),
 324         };
 325
 326         argc = parse_options(argc, argv, options, describe_usage, 0);
 327         if (max_candidates < 0)
 328                 max_candidates = 0;
 329         else if (max_candidates > MAX_TAGS)
 330                 max_candidates = MAX_TAGS;
 331
 332         save_commit_buffer = 0;
 333
 334         if (longformat && abbrev == 0)
 335                 die("--long is incompatible with --abbrev=0");
 336
 337         if (contains) {
 338                 const char **args = xmalloc((7 + argc) * sizeof(char*));
 339                 int i = 0;
 340                 args[i++] = "name-rev";
 341                 args[i++] = "--name-only";
 342                 args[i++] = "--no-undefined";
 343                 if (always)
 344                         args[i++] = "--always";
 345                 if (!all) {
 346                         args[i++] = "--tags";
 347                         if (pattern) {
 348                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 349                                 sprintf(s, "--refs=refs/tags/%s", pattern);
 350                                 args[i++] = s;
 351                         }
 352                 }
 353                 memcpy(args + i, argv, argc * sizeof(char*));
 354                 args[i + argc] = NULL;
 355                 return cmd_name_rev(i + argc, args, prefix);
 356         }
 357
 358         if (argc == 0) {
 359                 describe("HEAD", 1);
 360         } else {
 361                 while (argc-- > 0) {
 362                         describe(*argv++, argc == 0);
 363                 }
 364         }
 365         return 0;
 366 }