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