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 abbrev = DEFAULT_ABBREV;
  21 static int max_candidates = 10;
  22 const char *pattern = NULL;
  23
  24 struct commit_name {
  25         struct tag *tag;
  26         int prio; /* annotated tag = 2, tag = 1, head = 0 */
  27         unsigned char sha1[20];
  28         char path[FLEX_ARRAY]; /* more */
  29 };
  30 static const char *prio_names[] = {
  31         "head", "lightweight", "annotated",
  32 };
  33
  34 static void add_to_known_names(const char *path,
  35                                struct commit *commit,
  36                                int prio,
  37                                const unsigned char *sha1)
  38 {
  39         struct commit_name *e = commit->util;
  40         if (!e || e->prio < prio) {
  41                 size_t len = strlen(path)+1;
  42                 free(e);
  43                 e = xmalloc(sizeof(struct commit_name) + len);
  44                 e->tag = NULL;
  45                 e->prio = prio;
  46                 hashcpy(e->sha1, sha1);
  47                 memcpy(e->path, path, len);
  48                 commit->util = e;
  49         }
  50 }
  51
  52 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  53 {
  54         int might_be_tag = !prefixcmp(path, "refs/tags/");
  55         struct commit *commit;
  56         struct object *object;
  57         unsigned char peeled[20];
  58         int is_tag, prio;
  59
  60         if (!all && !might_be_tag)
  61                 return 0;
  62
  63         if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
  64                 commit = lookup_commit_reference_gently(peeled, 1);
  65                 if (!commit)
  66                         return 0;
  67                 is_tag = !!hashcmp(sha1, commit->object.sha1);
  68         } else {
  69                 commit = lookup_commit_reference_gently(sha1, 1);
  70                 object = parse_object(sha1);
  71                 if (!commit || !object)
  72                         return 0;
  73                 is_tag = object->type == OBJ_TAG;
  74         }
  75
  76         /* If --all, then any refs are used.
  77          * If --tags, then any tags are used.
  78          * Otherwise only annotated tags are used.
  79          */
  80         if (might_be_tag) {
  81                 if (is_tag) {
  82                         prio = 2;
  83                         if (pattern && fnmatch(pattern, path + 10, 0))
  84                                 prio = 0;
  85                 } else
  86                         prio = 1;
  87         }
  88         else
  89                 prio = 0;
  90
  91         if (!all) {
  92                 if (!prio)
  93                         return 0;
  94                 if (!tags && prio < 2)
  95                         return 0;
  96         }
  97         add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
  98         return 0;
  99 }
 100
 101 struct possible_tag {
 102         struct commit_name *name;
 103         int depth;
 104         int found_order;
 105         unsigned flag_within;
 106 };
 107
 108 static int compare_pt(const void *a_, const void *b_)
 109 {
 110         struct possible_tag *a = (struct possible_tag *)a_;
 111         struct possible_tag *b = (struct possible_tag *)b_;
 112         if (a->name->prio != b->name->prio)
 113                 return b->name->prio - a->name->prio;
 114         if (a->depth != b->depth)
 115                 return a->depth - b->depth;
 116         if (a->found_order != b->found_order)
 117                 return a->found_order - b->found_order;
 118         return 0;
 119 }
 120
 121 static unsigned long finish_depth_computation(
 122         struct commit_list **list,
 123         struct possible_tag *best)
 124 {
 125         unsigned long seen_commits = 0;
 126         while (*list) {
 127                 struct commit *c = pop_commit(list);
 128                 struct commit_list *parents = c->parents;
 129                 seen_commits++;
 130                 if (c->object.flags & best->flag_within) {
 131                         struct commit_list *a = *list;
 132                         while (a) {
 133                                 struct commit *i = a->item;
 134                                 if (!(i->object.flags & best->flag_within))
 135                                         break;
 136                                 a = a->next;
 137                         }
 138                         if (!a)
 139                                 break;
 140                 } else
 141                         best->depth++;
 142                 while (parents) {
 143                         struct commit *p = parents->item;
 144                         parse_commit(p);
 145                         if (!(p->object.flags & SEEN))
 146                                 insert_by_date(p, list);
 147                         p->object.flags |= c->object.flags;
 148                         parents = parents->next;
 149                 }
 150         }
 151         return seen_commits;
 152 }
 153
 154 static void display_name(struct commit_name *n)
 155 {
 156         if (n->prio == 2 && !n->tag) {
 157                 n->tag = lookup_tag(n->sha1);
 158                 if (!n->tag || !n->tag->tag)
 159                         die("annotated tag %s not available", n->path);
 160                 if (strcmp(n->tag->tag, n->path))
 161                         warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
 162         }
 163
 164         if (n->tag)
 165                 printf("%s", n->tag->tag);
 166         else
 167                 printf("%s", n->path);
 168 }
 169
 170 static void describe(const char *arg, int last_one)
 171 {
 172         unsigned char sha1[20];
 173         struct commit *cmit, *gave_up_on = NULL;
 174         struct commit_list *list;
 175         static int initialized = 0;
 176         struct commit_name *n;
 177         struct possible_tag all_matches[MAX_TAGS];
 178         unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 179         unsigned long seen_commits = 0;
 180
 181         if (get_sha1(arg, sha1))
 182                 die("Not a valid object name %s", arg);
 183         cmit = lookup_commit_reference(sha1);
 184         if (!cmit)
 185                 die("%s is not a valid '%s' object", arg, commit_type);
 186
 187         if (!initialized) {
 188                 initialized = 1;
 189                 for_each_ref(get_name, NULL);
 190         }
 191
 192         n = cmit->util;
 193         if (n) {
 194                 display_name(n);
 195                 printf("\n");
 196                 return;
 197         }
 198
 199         if (!max_candidates)
 200                 die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 201         if (debug)
 202                 fprintf(stderr, "searching to describe %s\n", arg);
 203
 204         list = NULL;
 205         cmit->object.flags = SEEN;
 206         commit_list_insert(cmit, &list);
 207         while (list) {
 208                 struct commit *c = pop_commit(&list);
 209                 struct commit_list *parents = c->parents;
 210                 seen_commits++;
 211                 n = c->util;
 212                 if (n) {
 213                         if (match_cnt < max_candidates) {
 214                                 struct possible_tag *t = &all_matches[match_cnt++];
 215                                 t->name = n;
 216                                 t->depth = seen_commits - 1;
 217                                 t->flag_within = 1u << match_cnt;
 218                                 t->found_order = match_cnt;
 219                                 c->object.flags |= t->flag_within;
 220                                 if (n->prio == 2)
 221                                         annotated_cnt++;
 222                         }
 223                         else {
 224                                 gave_up_on = c;
 225                                 break;
 226                         }
 227                 }
 228                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 229                         struct possible_tag *t = &all_matches[cur_match];
 230                         if (!(c->object.flags & t->flag_within))
 231                                 t->depth++;
 232                 }
 233                 if (annotated_cnt && !list) {
 234                         if (debug)
 235                                 fprintf(stderr, "finished search at %s\n",
 236                                         sha1_to_hex(c->object.sha1));
 237                         break;
 238                 }
 239                 while (parents) {
 240                         struct commit *p = parents->item;
 241                         parse_commit(p);
 242                         if (!(p->object.flags & SEEN))
 243                                 insert_by_date(p, &list);
 244                         p->object.flags |= c->object.flags;
 245                         parents = parents->next;
 246                 }
 247         }
 248
 249         if (!match_cnt)
 250                 die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
 251
 252         qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 253
 254         if (gave_up_on) {
 255                 insert_by_date(gave_up_on, &list);
 256                 seen_commits--;
 257         }
 258         seen_commits += finish_depth_computation(&list, &all_matches[0]);
 259         free_commit_list(list);
 260
 261         if (debug) {
 262                 for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 263                         struct possible_tag *t = &all_matches[cur_match];
 264                         fprintf(stderr, " %-11s %8d %s\n",
 265                                 prio_names[t->name->prio],
 266                                 t->depth, t->name->path);
 267                 }
 268                 fprintf(stderr, "traversed %lu commits\n", seen_commits);
 269                 if (gave_up_on) {
 270                         fprintf(stderr,
 271                                 "more than %i tags found; listed %i most recent\n"
 272                                 "gave up search at %s\n",
 273                                 max_candidates, max_candidates,
 274                                 sha1_to_hex(gave_up_on->object.sha1));
 275                 }
 276         }
 277
 278         display_name(all_matches[0].name);
 279         if (abbrev)
 280                 printf("-%d-g%s", all_matches[0].depth,
 281                        find_unique_abbrev(cmit->object.sha1, abbrev));
 282         printf("\n");
 283
 284         if (!last_one)
 285                 clear_commit_marks(cmit, -1);
 286 }
 287
 288 int cmd_describe(int argc, const char **argv, const char *prefix)
 289 {
 290         int contains = 0;
 291         struct option options[] = {
 292                 OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 293                 OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 294                 OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 295                 OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 296                 OPT__ABBREV(&abbrev),
 297                 OPT_SET_INT(0, "exact-match", &max_candidates,
 298                             "only output exact matches", 0),
 299                 OPT_INTEGER(0, "candidates", &max_candidates,
 300                             "consider <n> most recent tags (default: 10)"),
 301                 OPT_STRING(0, "match",       &pattern, "pattern",
 302                            "only consider tags matching <pattern>"),
 303                 OPT_END(),
 304         };
 305
 306         argc = parse_options(argc, argv, options, describe_usage, 0);
 307         if (max_candidates < 0)
 308                 max_candidates = 0;
 309         else if (max_candidates > MAX_TAGS)
 310                 max_candidates = MAX_TAGS;
 311
 312         save_commit_buffer = 0;
 313
 314         if (contains) {
 315                 const char **args = xmalloc((6 + argc) * sizeof(char*));
 316                 int i = 0;
 317                 args[i++] = "name-rev";
 318                 args[i++] = "--name-only";
 319                 args[i++] = "--no-undefined";
 320                 if (!all) {
 321                         args[i++] = "--tags";
 322                         if (pattern) {
 323                                 char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 324                                 sprintf(s, "--refs=refs/tags/%s", pattern);
 325                                 args[i++] = s;
 326                         }
 327                 }
 328                 memcpy(args + i, argv, argc * sizeof(char*));
 329                 args[i + argc] = NULL;
 330                 return cmd_name_rev(i + argc, args, prefix);
 331         }
 332
 333         if (argc == 0) {
 334                 describe("HEAD", 1);
 335         } else {
 336                 while (argc-- > 0) {
 337                         describe(*argv++, argc == 0);
 338                 }
 339         }
 340         return 0;
 341 }