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         }
 100         add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
 101         return 0;
 102 }
 103
 104 struct possible_tag {
 105         struct commit_name *name;
 106         int depth;
 107         int found_order;
 108         unsigned flag_within;
 109 };
 110
 111 static int compare_pt(const void *a_, const void *b_)
 112 {
 113         struct possible_tag *a = (struct possible_tag *)a_;
 114         struct possible_tag *b = (struct possible_tag *)b_;
 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 || parse_tag(n->tag) || !n->tag->tag)
 160                         die("annotated tag %s not available", n->path);
 161                 if (strcmp(n->tag->tag, all ? n->path + 5 : 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 }
 170
 171 static void show_suffix(int depth, const unsigned char *sha1)
 172 {
 173         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 174 }
 175
 176 static void describe(const char *arg, int last_one)
 177 {
 178         unsigned char sha1[20];
 179         struct commit *cmit, *gave_up_on = NULL;
 180         struct commit_list *list;
 181         struct commit_name *n;
 182         struct possible_tag all_matches[MAX_TAGS];
 183         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 184         unsigned long seen_commits = 0;
 185         unsigned int unannotated_cnt = 0;
 186
 187         if (get_sha1(arg, sha1))
 188                 die("Not a valid object name %s", arg);
 189         cmit = lookup_commit_reference(sha1);
 190         if (!cmit)
 191                 die("%s is not a valid '%s' object", arg, commit_type);
 192
 193         n = cmit->util;
 194         if (n) {
 195                 /*
 196                  * Exact match to an existing ref.
 197                  */
 198                 display_name(n);
 199                 if (longformat)
 200                         show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 201                 printf("\n");
 202                 return;
 203         }
 204
 205         if (!max_candidates)
 206                 die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 207         if (debug)
 208                 fprintf(stderr, "searching to describe %s\n", arg);
 209
 210         list = NULL;
 211         cmit->object.flags = SEEN;
 212         commit_list_insert(cmit, &list);
 213         while (list) {
 214                 struct commit *c = pop_commit(&list);
 215                 struct commit_list *parents = c->parents;
 216                 seen_commits++;
 217                 n = c->util;
 218                 if (n) {
 219                         if (!tags && !all && n->prio < 2) {
 220                                 unannotated_cnt++;
 221                         } else if (match_cnt < max_candidates) {
 222                                 struct possible_tag *t = &all_matches[match_cnt++];
 223                                 t->name = n;
 224                                 t->depth = seen_commits - 1;
 225                                 t->flag_within = 1u << match_cnt;
 226                                 t->found_order = match_cnt;
 227                                 c->object.flags |= t->flag_within;
 228                                 if (n->prio == 2)
 229                                         annotated_cnt++;
 230                         }
 231                         else {
 232                                 gave_up_on = c;
 233                                 break;
 234                         }
 235                 }
 236                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 237                         struct possible_tag *t = &all_matches[cur_match];
 238                         if (!(c->object.flags & t->flag_within))
 239                                 t->depth++;
 240                 }
 241                 if (annotated_cnt && !list) {
 242                         if (debug)
 243                                 fprintf(stderr, "finished search at %s\n",
 244                                         sha1_to_hex(c->object.sha1));
 245                         break;
 246                 }
 247                 while (parents) {
 248                         struct commit *p = parents->item;
 249                         parse_commit(p);
 250                         if (!(p->object.flags & SEEN))
 251                                 insert_by_date(p, &list);
 252                         p->object.flags |= c->object.flags;
 253                         parents = parents->next;
 254                 }
 255         }
 256
 257         if (!match_cnt) {
 258                 const unsigned char *sha1 = cmit->object.sha1;
 259                 if (always) {
 260                         printf("%s\n", find_unique_abbrev(sha1, abbrev));
 261                         return;
 262                 }
 263                 if (unannotated_cnt)
 264                         die("No annotated tags can describe '%s'.\n"
 265                             "However, there were unannotated tags: try --tags.",
 266                             sha1_to_hex(sha1));
 267                 else
 268                         die("No tags can describe '%s'.\n"
 269                             "Try --always, or create some tags.",
 270                             sha1_to_hex(sha1));
 271         }
 272
 273         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 274
 275         if (gave_up_on) {
 276                 insert_by_date(gave_up_on, &list);
 277                 seen_commits--;
 278         }
 279         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 280         free_commit_list(list);
 281
 282         if (debug) {
 283                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 284                         struct possible_tag *t = &all_matches[cur_match];
 285                         fprintf(stderr, " %-11s %8d %s\n",
 286                                 prio_names[t->name->prio],
 287                                 t->depth, t->name->path);
 288                 }
 289                 fprintf(stderr, "traversed %lu commits\n", seen_commits);
 290                 if (gave_up_on) {
 291                         fprintf(stderr,
 292                                 "more than %i tags found; listed %i most recent\n"
 293                                 "gave up search at %s\n",
 294                                 max_candidates, max_candidates,
 295                                 sha1_to_hex(gave_up_on->object.sha1));
 296                 }
 297         }
 298
 299         display_name(all_matches[0].name);
 300         if (abbrev)
 301                 show_suffix(all_matches[0].depth, cmit->object.sha1);
 302         printf("\n");
 303
 304         if (!last_one)
 305                 clear_commit_marks(cmit, -1);
 306 }
 307
 308 int cmd_describe(int argc, const char **argv, const char *prefix)
 309 {
 310         int contains = 0;
 311         struct option options[] = {
 312                 OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 313                 OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 314                 OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 315                 OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 316                 OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
 317                 OPT__ABBREV(&abbrev),
 318                 OPT_SET_INT(0, "exact-match", &max_candidates,
 319                             "only output exact matches", 0),
 320                 OPT_INTEGER(0, "candidates", &max_candidates,
 321                             "consider <n> most recent tags (default: 10)"),
 322                 OPT_STRING(0, "match",       &pattern, "pattern",
 323                            "only consider tags matching <pattern>"),
 324                 OPT_BOOLEAN(0, "always",     &always,
 325                            "show abbreviated commit object as fallback"),
 326                 OPT_END(),
 327         };
 328
 329         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 330         if (max_candidates < 0)
 331                 max_candidates = 0;
 332         else if (max_candidates > MAX_TAGS)
 333                 max_candidates = MAX_TAGS;
 334
 335         save_commit_buffer = 0;
 336
 337         if (longformat && abbrev == 0)
 338                 die("--long is incompatible with --abbrev=0");
 339
 340         if (contains) {
 341                 const char **args = xmalloc((7 + argc) * sizeof(char *));
 342                 int i = 0;
 343                 args[i++] = "name-rev";
 344                 args[i++] = "--name-only";
 345                 args[i++] = "--no-undefined";
 346                 if (always)
 347                         args[i++] = "--always";
 348                 if (!all) {
 349                         args[i++] = "--tags";
 350                         if (pattern) {
 351                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 352                                 sprintf(s, "--refs=refs/tags/%s", pattern);
 353                                 args[i++] = s;
 354                         }
 355                 }
 356                 memcpy(args + i, argv, argc * sizeof(char *));
 357                 args[i + argc] = NULL;
 358                 return cmd_name_rev(i + argc, args, prefix);
 359         }
 360
 361         for_each_ref(get_name, NULL);
 362         if (!found_names && !always)
 363                 die("No names found, cannot describe anything.");
 364
 365         if (argc == 0) {
 366                 describe("HEAD", 1);
 367         } else {
 368                 while (argc-- > 0) {
 369                         describe(*argv++, argc == 0);
 370                 }
 371         }
 372         return 0;
 373 }