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; /* Any valid ref can be used */
  19 static int tags;        /* Allow lightweight tags */
  20 static int longformat;
  21 static int abbrev = DEFAULT_ABBREV;
  22 static int max_candidates = 10;
  23 static int found_names;
  24 static const char *pattern;
  25 static int always;
  26
  27 struct commit_name {
  28         struct tag *tag;
  29         int prio; /* annotated tag = 2, tag = 1, head = 0 */
  30         unsigned char sha1[20];
  31         char path[FLEX_ARRAY]; /* more */
  32 };
  33 static const char *prio_names[] = {
  34         "head", "lightweight", "annotated",
  35 };
  36
  37 static void add_to_known_names(const char *path,
  38                                struct commit *commit,
  39                                int prio,
  40                                const unsigned char *sha1)
  41 {
  42         struct commit_name *e = commit->util;
  43         if (!e || e->prio < prio) {
  44                 size_t len = strlen(path)+1;
  45                 free(e);
  46                 e = xmalloc(sizeof(struct commit_name) + len);
  47                 e->tag = NULL;
  48                 e->prio = prio;
  49                 hashcpy(e->sha1, sha1);
  50                 memcpy(e->path, path, len);
  51                 commit->util = e;
  52         }
  53         found_names = 1;
  54 }
  55
  56 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  57 {
  58         int might_be_tag = !prefixcmp(path, "refs/tags/");
  59         struct commit *commit;
  60         struct object *object;
  61         unsigned char peeled[20];
  62         int is_tag, prio;
  63
  64         if (!all && !might_be_tag)
  65                 return 0;
  66
  67         if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
  68                 commit = lookup_commit_reference_gently(peeled, 1);
  69                 if (!commit)
  70                         return 0;
  71                 is_tag = !!hashcmp(sha1, commit->object.sha1);
  72         } else {
  73                 commit = lookup_commit_reference_gently(sha1, 1);
  74                 object = parse_object(sha1);
  75                 if (!commit || !object)
  76                         return 0;
  77                 is_tag = object->type == OBJ_TAG;
  78         }
  79
  80         /* If --all, then any refs are used.
  81          * If --tags, then any tags are used.
  82          * Otherwise only annotated tags are used.
  83          */
  84         if (might_be_tag) {
  85                 if (is_tag)
  86                         prio = 2;
  87                 else
  88                         prio = 1;
  89
  90                 if (pattern && fnmatch(pattern, path + 10, 0))
  91                         prio = 0;
  92         }
  93         else
  94                 prio = 0;
  95
  96         if (!all) {
  97                 if (!prio)
  98                         return 0;
  99                 if (!tags && prio < 2)
 100                         return 0;
 101         }
 102         add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
 103         return 0;
 104 }
 105
 106 struct possible_tag {
 107         struct commit_name *name;
 108         int depth;
 109         int found_order;
 110         unsigned flag_within;
 111 };
 112
 113 static int compare_pt(const void *a_, const void *b_)
 114 {
 115         struct possible_tag *a = (struct possible_tag *)a_;
 116         struct possible_tag *b = (struct possible_tag *)b_;
 117         if (a->depth != b->depth)
 118                 return a->depth - b->depth;
 119         if (a->found_order != b->found_order)
 120                 return a->found_order - b->found_order;
 121         return 0;
 122 }
 123
 124 static unsigned long finish_depth_computation(
 125         struct commit_list **list,
 126         struct possible_tag *best)
 127 {
 128         unsigned long seen_commits = 0;
 129         while (*list) {
 130                 struct commit *c = pop_commit(list);
 131                 struct commit_list *parents = c->parents;
 132                 seen_commits++;
 133                 if (c->object.flags & best->flag_within) {
 134                         struct commit_list *a = *list;
 135                         while (a) {
 136                                 struct commit *i = a->item;
 137                                 if (!(i->object.flags & best->flag_within))
 138                                         break;
 139                                 a = a->next;
 140                         }
 141                         if (!a)
 142                                 break;
 143                 } else
 144                         best->depth++;
 145                 while (parents) {
 146                         struct commit *p = parents->item;
 147                         parse_commit(p);
 148                         if (!(p->object.flags & SEEN))
 149                                 insert_by_date(p, list);
 150                         p->object.flags |= c->object.flags;
 151                         parents = parents->next;
 152                 }
 153         }
 154         return seen_commits;
 155 }
 156
 157 static void display_name(struct commit_name *n)
 158 {
 159         if (n->prio == 2 && !n->tag) {
 160                 n->tag = lookup_tag(n->sha1);
 161                 if (!n->tag || parse_tag(n->tag) || !n->tag->tag)
 162                         die("annotated tag %s not available", n->path);
 163                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 164                         warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
 165         }
 166
 167         if (n->tag)
 168                 printf("%s", n->tag->tag);
 169         else
 170                 printf("%s", n->path);
 171 }
 172
 173 static void show_suffix(int depth, const unsigned char *sha1)
 174 {
 175         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 176 }
 177
 178 static void describe(const char *arg, int last_one)
 179 {
 180         unsigned char sha1[20];
 181         struct commit *cmit, *gave_up_on = NULL;
 182         struct commit_list *list;
 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         n = cmit->util;
 195         if (n) {
 196                 /*
 197                  * Exact match to an existing ref.
 198                  */
 199                 display_name(n);
 200                 if (longformat)
 201                         show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 202                 printf("\n");
 203                 return;
 204         }
 205
 206         if (!max_candidates)
 207                 die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 208         if (debug)
 209                 fprintf(stderr, "searching to describe %s\n", arg);
 210
 211         list = NULL;
 212         cmit->object.flags = SEEN;
 213         commit_list_insert(cmit, &list);
 214         while (list) {
 215                 struct commit *c = pop_commit(&list);
 216                 struct commit_list *parents = c->parents;
 217                 seen_commits++;
 218                 n = c->util;
 219                 if (n) {
 220                         if (match_cnt < max_candidates) {
 221                                 struct possible_tag *t = &all_matches[match_cnt++];
 222                                 t->name = n;
 223                                 t->depth = seen_commits - 1;
 224                                 t->flag_within = 1u << match_cnt;
 225                                 t->found_order = match_cnt;
 226                                 c->object.flags |= t->flag_within;
 227                                 if (n->prio == 2)
 228                                         annotated_cnt++;
 229                         }
 230                         else {
 231                                 gave_up_on = c;
 232                                 break;
 233                         }
 234                 }
 235                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 236                         struct possible_tag *t = &all_matches[cur_match];
 237                         if (!(c->object.flags & t->flag_within))
 238                                 t->depth++;
 239                 }
 240                 if (annotated_cnt && !list) {
 241                         if (debug)
 242                                 fprintf(stderr, "finished search at %s\n",
 243                                         sha1_to_hex(c->object.sha1));
 244                         break;
 245                 }
 246                 while (parents) {
 247                         struct commit *p = parents->item;
 248                         parse_commit(p);
 249                         if (!(p->object.flags & SEEN))
 250                                 insert_by_date(p, &list);
 251                         p->object.flags |= c->object.flags;
 252                         parents = parents->next;
 253                 }
 254         }
 255
 256         if (!match_cnt) {
 257                 const unsigned char *sha1 = cmit->object.sha1;
 258                 if (always) {
 259                         printf("%s\n", find_unique_abbrev(sha1, abbrev));
 260                         return;
 261                 }
 262                 die("cannot describe '%s'", sha1_to_hex(sha1));
 263         }
 264
 265         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 266
 267         if (gave_up_on) {
 268                 insert_by_date(gave_up_on, &list);
 269                 seen_commits--;
 270         }
 271         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 272         free_commit_list(list);
 273
 274         if (debug) {
 275                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 276                         struct possible_tag *t = &all_matches[cur_match];
 277                         fprintf(stderr, " %-11s %8d %s\n",
 278                                 prio_names[t->name->prio],
 279                                 t->depth, t->name->path);
 280                 }
 281                 fprintf(stderr, "traversed %lu commits\n", seen_commits);
 282                 if (gave_up_on) {
 283                         fprintf(stderr,
 284                                 "more than %i tags found; listed %i most recent\n"
 285                                 "gave up search at %s\n",
 286                                 max_candidates, max_candidates,
 287                                 sha1_to_hex(gave_up_on->object.sha1));
 288                 }
 289         }
 290
 291         display_name(all_matches[0].name);
 292         if (abbrev)
 293                 show_suffix(all_matches[0].depth, cmit->object.sha1);
 294         printf("\n");
 295
 296         if (!last_one)
 297                 clear_commit_marks(cmit, -1);
 298 }
 299
 300 int cmd_describe(int argc, const char **argv, const char *prefix)
 301 {
 302         int contains = 0;
 303         struct option options[] = {
 304                 OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 305                 OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 306                 OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 307                 OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 308                 OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
 309                 OPT__ABBREV(&abbrev),
 310                 OPT_SET_INT(0, "exact-match", &max_candidates,
 311                             "only output exact matches", 0),
 312                 OPT_INTEGER(0, "candidates", &max_candidates,
 313                             "consider <n> most recent tags (default: 10)"),
 314                 OPT_STRING(0, "match",       &pattern, "pattern",
 315                            "only consider tags matching <pattern>"),
 316                 OPT_BOOLEAN(0, "always",     &always,
 317                            "show abbreviated commit object as fallback"),
 318                 OPT_END(),
 319         };
 320
 321         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 322         if (max_candidates < 0)
 323                 max_candidates = 0;
 324         else if (max_candidates > MAX_TAGS)
 325                 max_candidates = MAX_TAGS;
 326
 327         save_commit_buffer = 0;
 328
 329         if (longformat && abbrev == 0)
 330                 die("--long is incompatible with --abbrev=0");
 331
 332         if (contains) {
 333                 const char **args = xmalloc((7 + argc) * sizeof(char *));
 334                 int i = 0;
 335                 args[i++] = "name-rev";
 336                 args[i++] = "--name-only";
 337                 args[i++] = "--no-undefined";
 338                 if (always)
 339                         args[i++] = "--always";
 340                 if (!all) {
 341                         args[i++] = "--tags";
 342                         if (pattern) {
 343                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 344                                 sprintf(s, "--refs=refs/tags/%s", pattern);
 345                                 args[i++] = s;
 346                         }
 347                 }
 348                 memcpy(args + i, argv, argc * sizeof(char *));
 349                 args[i + argc] = NULL;
 350                 return cmd_name_rev(i + argc, args, prefix);
 351         }
 352
 353         for_each_ref(get_name, NULL);
 354         if (!found_names && !always)
 355                 die("No names found, cannot describe anything.");
 356
 357         if (argc == 0) {
 358                 describe("HEAD", 1);
 359         } else {
 360                 while (argc-- > 0) {
 361                         describe(*argv++, argc == 0);
 362                 }
 363         }
 364         return 0;
 365 }