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 #include "diff.h"
   9
  10 #define SEEN            (1u<<0)
  11 #define MAX_TAGS        (FLAG_BITS - 1)
  12
  13 static const char * const describe_usage[] = {
  14         "git describe [options] <committish>*",
  15         "git describe [options] --dirty",
  16         NULL
  17 };
  18
  19 static int debug;       /* Display lots of verbose info */
  20 static int all; /* Any valid ref can be used */
  21 static int tags;        /* Allow lightweight tags */
  22 static int longformat;
  23 static int abbrev = DEFAULT_ABBREV;
  24 static int max_candidates = 10;
  25 static int found_names;
  26 static const char *pattern;
  27 static int always;
  28 static const char *dirty;
  29
  30 /* diff-index command arguments to check if working tree is dirty. */
  31 static const char *diff_index_args[] = {
  32         "diff-index", "--quiet", "HEAD", "--", NULL
  33 };
  34
  35
  36 struct commit_name {
  37         struct tag *tag;
  38         int prio; /* annotated tag = 2, tag = 1, head = 0 */
  39         unsigned char sha1[20];
  40         char path[FLEX_ARRAY]; /* more */
  41 };
  42 static const char *prio_names[] = {
  43         "head", "lightweight", "annotated",
  44 };
  45
  46 static void add_to_known_names(const char *path,
  47                                struct commit *commit,
  48                                int prio,
  49                                const unsigned char *sha1)
  50 {
  51         struct commit_name *e = commit->util;
  52         if (!e || e->prio < prio) {
  53                 size_t len = strlen(path)+1;
  54                 free(e);
  55                 e = xmalloc(sizeof(struct commit_name) + len);
  56                 e->tag = NULL;
  57                 e->prio = prio;
  58                 hashcpy(e->sha1, sha1);
  59                 memcpy(e->path, path, len);
  60                 commit->util = e;
  61         }
  62         found_names = 1;
  63 }
  64
  65 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  66 {
  67         int might_be_tag = !prefixcmp(path, "refs/tags/");
  68         struct commit *commit;
  69         struct object *object;
  70         unsigned char peeled[20];
  71         int is_tag, prio;
  72
  73         if (!all && !might_be_tag)
  74                 return 0;
  75
  76         if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
  77                 commit = lookup_commit_reference_gently(peeled, 1);
  78                 if (!commit)
  79                         return 0;
  80                 is_tag = !!hashcmp(sha1, commit->object.sha1);
  81         } else {
  82                 commit = lookup_commit_reference_gently(sha1, 1);
  83                 object = parse_object(sha1);
  84                 if (!commit || !object)
  85                         return 0;
  86                 is_tag = object->type == OBJ_TAG;
  87         }
  88
  89         /* If --all, then any refs are used.
  90          * If --tags, then any tags are used.
  91          * Otherwise only annotated tags are used.
  92          */
  93         if (might_be_tag) {
  94                 if (is_tag)
  95                         prio = 2;
  96                 else
  97                         prio = 1;
  98
  99                 if (pattern && fnmatch(pattern, path + 10, 0))
 100                         prio = 0;
 101         }
 102         else
 103                 prio = 0;
 104
 105         if (!all) {
 106                 if (!prio)
 107                         return 0;
 108                 if (!tags && prio < 2)
 109                         return 0;
 110         }
 111         add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
 112         return 0;
 113 }
 114
 115 struct possible_tag {
 116         struct commit_name *name;
 117         int depth;
 118         int found_order;
 119         unsigned flag_within;
 120 };
 121
 122 static int compare_pt(const void *a_, const void *b_)
 123 {
 124         struct possible_tag *a = (struct possible_tag *)a_;
 125         struct possible_tag *b = (struct possible_tag *)b_;
 126         if (a->depth != b->depth)
 127                 return a->depth - b->depth;
 128         if (a->found_order != b->found_order)
 129                 return a->found_order - b->found_order;
 130         return 0;
 131 }
 132
 133 static unsigned long finish_depth_computation(
 134         struct commit_list **list,
 135         struct possible_tag *best)
 136 {
 137         unsigned long seen_commits = 0;
 138         while (*list) {
 139                 struct commit *c = pop_commit(list);
 140                 struct commit_list *parents = c->parents;
 141                 seen_commits++;
 142                 if (c->object.flags & best->flag_within) {
 143                         struct commit_list *a = *list;
 144                         while (a) {
 145                                 struct commit *i = a->item;
 146                                 if (!(i->object.flags & best->flag_within))
 147                                         break;
 148                                 a = a->next;
 149                         }
 150                         if (!a)
 151                                 break;
 152                 } else
 153                         best->depth++;
 154                 while (parents) {
 155                         struct commit *p = parents->item;
 156                         parse_commit(p);
 157                         if (!(p->object.flags & SEEN))
 158                                 insert_by_date(p, list);
 159                         p->object.flags |= c->object.flags;
 160                         parents = parents->next;
 161                 }
 162         }
 163         return seen_commits;
 164 }
 165
 166 static void display_name(struct commit_name *n)
 167 {
 168         if (n->prio == 2 && !n->tag) {
 169                 n->tag = lookup_tag(n->sha1);
 170                 if (!n->tag || parse_tag(n->tag) || !n->tag->tag)
 171                         die("annotated tag %s not available", n->path);
 172                 if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 173                         warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
 174         }
 175
 176         if (n->tag)
 177                 printf("%s", n->tag->tag);
 178         else
 179                 printf("%s", n->path);
 180 }
 181
 182 static void show_suffix(int depth, const unsigned char *sha1)
 183 {
 184         printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 185 }
 186
 187 static void describe(const char *arg, int last_one)
 188 {
 189         unsigned char sha1[20];
 190         struct commit *cmit, *gave_up_on = NULL;
 191         struct commit_list *list;
 192         struct commit_name *n;
 193         struct possible_tag all_matches[MAX_TAGS];
 194         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 195         unsigned long seen_commits = 0;
 196
 197         if (get_sha1(arg, sha1))
 198                 die("Not a valid object name %s", arg);
 199         cmit = lookup_commit_reference(sha1);
 200         if (!cmit)
 201                 die("%s is not a valid '%s' object", arg, commit_type);
 202
 203         n = cmit->util;
 204         if (n) {
 205                 /*
 206                  * Exact match to an existing ref.
 207                  */
 208                 display_name(n);
 209                 if (longformat)
 210                         show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 211                 if (dirty)
 212                         printf("%s", dirty);
 213                 printf("\n");
 214                 return;
 215         }
 216
 217         if (!max_candidates)
 218                 die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 219         if (debug)
 220                 fprintf(stderr, "searching to describe %s\n", arg);
 221
 222         list = NULL;
 223         cmit->object.flags = SEEN;
 224         commit_list_insert(cmit, &list);
 225         while (list) {
 226                 struct commit *c = pop_commit(&list);
 227                 struct commit_list *parents = c->parents;
 228                 seen_commits++;
 229                 n = c->util;
 230                 if (n) {
 231                         if (match_cnt < max_candidates) {
 232                                 struct possible_tag *t = &all_matches[match_cnt++];
 233                                 t->name = n;
 234                                 t->depth = seen_commits - 1;
 235                                 t->flag_within = 1u << match_cnt;
 236                                 t->found_order = match_cnt;
 237                                 c->object.flags |= t->flag_within;
 238                                 if (n->prio == 2)
 239                                         annotated_cnt++;
 240                         }
 241                         else {
 242                                 gave_up_on = c;
 243                                 break;
 244                         }
 245                 }
 246                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 247                         struct possible_tag *t = &all_matches[cur_match];
 248                         if (!(c->object.flags & t->flag_within))
 249                                 t->depth++;
 250                 }
 251                 if (annotated_cnt && !list) {
 252                         if (debug)
 253                                 fprintf(stderr, "finished search at %s\n",
 254                                         sha1_to_hex(c->object.sha1));
 255                         break;
 256                 }
 257                 while (parents) {
 258                         struct commit *p = parents->item;
 259                         parse_commit(p);
 260                         if (!(p->object.flags & SEEN))
 261                                 insert_by_date(p, &list);
 262                         p->object.flags |= c->object.flags;
 263                         parents = parents->next;
 264                 }
 265         }
 266
 267         if (!match_cnt) {
 268                 const unsigned char *sha1 = cmit->object.sha1;
 269                 if (always) {
 270                         printf("%s", find_unique_abbrev(sha1, abbrev));
 271                         if (dirty)
 272                                 printf("%s", dirty);
 273                         printf("\n");
 274                         return;
 275                 }
 276                 die("cannot describe '%s'", sha1_to_hex(sha1));
 277         }
 278
 279         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 280
 281         if (gave_up_on) {
 282                 insert_by_date(gave_up_on, &list);
 283                 seen_commits--;
 284         }
 285         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 286         free_commit_list(list);
 287
 288         if (debug) {
 289                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 290                         struct possible_tag *t = &all_matches[cur_match];
 291                         fprintf(stderr, " %-11s %8d %s\n",
 292                                 prio_names[t->name->prio],
 293                                 t->depth, t->name->path);
 294                 }
 295                 fprintf(stderr, "traversed %lu commits\n", seen_commits);
 296                 if (gave_up_on) {
 297                         fprintf(stderr,
 298                                 "more than %i tags found; listed %i most recent\n"
 299                                 "gave up search at %s\n",
 300                                 max_candidates, max_candidates,
 301                                 sha1_to_hex(gave_up_on->object.sha1));
 302                 }
 303         }
 304
 305         display_name(all_matches[0].name);
 306         if (abbrev)
 307                 show_suffix(all_matches[0].depth, cmit->object.sha1);
 308         if (dirty)
 309                 printf("%s", dirty);
 310         printf("\n");
 311
 312         if (!last_one)
 313                 clear_commit_marks(cmit, -1);
 314 }
 315
 316 int cmd_describe(int argc, const char **argv, const char *prefix)
 317 {
 318         int contains = 0;
 319         struct option options[] = {
 320                 OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 321                 OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 322                 OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 323                 OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 324                 OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
 325                 OPT__ABBREV(&abbrev),
 326                 OPT_SET_INT(0, "exact-match", &max_candidates,
 327                             "only output exact matches", 0),
 328                 OPT_INTEGER(0, "candidates", &max_candidates,
 329                             "consider <n> most recent tags (default: 10)"),
 330                 OPT_STRING(0, "match",       &pattern, "pattern",
 331                            "only consider tags matching <pattern>"),
 332                 OPT_BOOLEAN(0, "always",     &always,
 333                            "show abbreviated commit object as fallback"),
 334                 {OPTION_STRING, 0, "dirty",  &dirty, "mark",
 335                            "append <mark> on dirty working tree (default: \"-dirty\")",
 336                  PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 337                 OPT_END(),
 338         };
 339
 340         argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 341         if (max_candidates < 0)
 342                 max_candidates = 0;
 343         else if (max_candidates > MAX_TAGS)
 344                 max_candidates = MAX_TAGS;
 345
 346         save_commit_buffer = 0;
 347
 348         if (longformat && abbrev == 0)
 349                 die("--long is incompatible with --abbrev=0");
 350
 351         if (contains) {
 352                 const char **args = xmalloc((7 + argc) * sizeof(char *));
 353                 int i = 0;
 354                 args[i++] = "name-rev";
 355                 args[i++] = "--name-only";
 356                 args[i++] = "--no-undefined";
 357                 if (always)
 358                         args[i++] = "--always";
 359                 if (!all) {
 360                         args[i++] = "--tags";
 361                         if (pattern) {
 362                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 363                                 sprintf(s, "--refs=refs/tags/%s", pattern);
 364                                 args[i++] = s;
 365                         }
 366                 }
 367                 memcpy(args + i, argv, argc * sizeof(char *));
 368                 args[i + argc] = NULL;
 369                 return cmd_name_rev(i + argc, args, prefix);
 370         }
 371
 372         for_each_ref(get_name, NULL);
 373         if (!found_names && !always)
 374                 die("No names found, cannot describe anything.");
 375
 376         if (argc == 0) {
 377                 if (dirty && !cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1, diff_index_args, prefix))
 378                         dirty = NULL;
 379                 describe("HEAD", 1);
 380         } else if (dirty) {
 381                 die("--dirty is incompatible with committishes");
 382         } else {
 383                 while (argc-- > 0) {
 384                         describe(*argv++, argc == 0);
 385                 }
 386         }
 387         return 0;
 388 }