builtin-describe.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "tag.h"
   4 #include "refs.h"
   5 #include "diff.h"
   6 #include "diffcore.h"
   7 #include "revision.h"
   8 #include "builtin.h"
   9
  10 static const char describe_usage[] =
  11 "git-describe [--all] [--tags] [--abbrev=<n>] <committish>*";
  12
  13 static int all; /* Default to annotated tags only */
  14 static int tags;        /* But allow any tags if --tags is specified */
  15
  16 static int abbrev = DEFAULT_ABBREV;
  17
  18 static int names, allocs;
  19 static struct commit_name {
  20         struct commit *commit;
  21         int prio; /* annotated tag = 2, tag = 1, head = 0 */
  22         char path[FLEX_ARRAY]; /* more */
  23 } **name_array = NULL;
  24
  25 static struct commit_name *match(struct commit *cmit)
  26 {
  27         int i = names;
  28         struct commit_name **p = name_array;
  29
  30         while (i-- > 0) {
  31                 struct commit_name *n = *p++;
  32                 if (n->commit == cmit)
  33                         return n;
  34         }
  35         return NULL;
  36 }
  37
  38 static void add_to_known_names(const char *path,
  39                                struct commit *commit,
  40                                int prio)
  41 {
  42         int idx;
  43         int len = strlen(path)+1;
  44         struct commit_name *name = xmalloc(sizeof(struct commit_name) + len);
  45
  46         name->commit = commit;
  47         name->prio = prio;
  48         memcpy(name->path, path, len);
  49         idx = names;
  50         if (idx >= allocs) {
  51                 allocs = (idx + 50) * 3 / 2;
  52                 name_array = xrealloc(name_array, allocs*sizeof(*name_array));
  53         }
  54         name_array[idx] = name;
  55         names = ++idx;
  56 }
  57
  58 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  59 {
  60         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
  61         struct object *object;
  62         int prio;
  63
  64         if (!commit)
  65                 return 0;
  66         object = parse_object(sha1);
  67         /* If --all, then any refs are used.
  68          * If --tags, then any tags are used.
  69          * Otherwise only annotated tags are used.
  70          */
  71         if (!strncmp(path, "refs/tags/", 10)) {
  72                 if (object->type == OBJ_TAG)
  73                         prio = 2;
  74                 else
  75                         prio = 1;
  76         }
  77         else
  78                 prio = 0;
  79
  80         if (!all) {
  81                 if (!prio)
  82                         return 0;
  83                 if (!tags && prio < 2)
  84                         return 0;
  85         }
  86         add_to_known_names(all ? path + 5 : path + 10, commit, prio);
  87         return 0;
  88 }
  89
  90 static int compare_names(const void *_a, const void *_b)
  91 {
  92         struct commit_name *a = *(struct commit_name **)_a;
  93         struct commit_name *b = *(struct commit_name **)_b;
  94         unsigned long a_date = a->commit->date;
  95         unsigned long b_date = b->commit->date;
  96
  97         if (a->prio != b->prio)
  98                 return b->prio - a->prio;
  99         return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
 100 }
 101
 102 struct possible_tag {
 103         struct possible_tag *next;
 104         struct commit_name *name;
 105         unsigned long depth;
 106 };
 107
 108 static void describe(const char *arg, int last_one)
 109 {
 110         unsigned char sha1[20];
 111         struct commit *cmit;
 112         struct commit_list *list;
 113         static int initialized = 0;
 114         struct commit_name *n;
 115         struct possible_tag *all_matches, *min_match, *cur_match;
 116
 117         if (get_sha1(arg, sha1))
 118                 die("Not a valid object name %s", arg);
 119         cmit = lookup_commit_reference(sha1);
 120         if (!cmit)
 121                 die("%s is not a valid '%s' object", arg, commit_type);
 122
 123         if (!initialized) {
 124                 initialized = 1;
 125                 for_each_ref(get_name, NULL);
 126                 qsort(name_array, names, sizeof(*name_array), compare_names);
 127         }
 128
 129         n = match(cmit);
 130         if (n) {
 131                 printf("%s\n", n->path);
 132                 return;
 133         }
 134
 135         list = NULL;
 136         all_matches = NULL;
 137         cur_match = NULL;
 138         commit_list_insert(cmit, &list);
 139         while (list) {
 140                 struct commit *c = pop_commit(&list);
 141                 n = match(c);
 142                 if (n) {
 143                         struct possible_tag *p = xmalloc(sizeof(*p));
 144                         p->name = n;
 145                         p->next = NULL;
 146                         if (cur_match)
 147                                 cur_match->next = p;
 148                         else
 149                                 all_matches = p;
 150                         cur_match = p;
 151                 } else {
 152                         struct commit_list *parents = c->parents;
 153                         while (parents) {
 154                                 struct commit *p = parents->item;
 155                                 parse_commit(p);
 156                                 if (!(p->object.flags & SEEN)) {
 157                                         p->object.flags |= SEEN;
 158                                         insert_by_date(p, &list);
 159                                 }
 160                                 parents = parents->next;
 161                         }
 162                 }
 163         }
 164
 165         if (!all_matches)
 166                 die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
 167
 168         min_match = NULL;
 169         for (cur_match = all_matches; cur_match; cur_match = cur_match->next) {
 170                 struct rev_info revs;
 171                 struct commit *tagged = cur_match->name->commit;
 172
 173                 clear_commit_marks(cmit, -1);
 174                 init_revisions(&revs, NULL);
 175                 tagged->object.flags |= UNINTERESTING;
 176                 add_pending_object(&revs, &tagged->object, NULL);
 177                 add_pending_object(&revs, &cmit->object, NULL);
 178
 179                 prepare_revision_walk(&revs);
 180                 cur_match->depth = 0;
 181                 while ((!min_match || cur_match->depth < min_match->depth)
 182                         && get_revision(&revs))
 183                         cur_match->depth++;
 184                 if (!min_match || cur_match->depth < min_match->depth)
 185                         min_match = cur_match;
 186                 free_commit_list(revs.commits);
 187         }
 188         printf("%s-g%s\n", min_match->name->path,
 189                    find_unique_abbrev(cmit->object.sha1, abbrev));
 190
 191         if (!last_one) {
 192                 for (cur_match = all_matches; cur_match; cur_match = min_match) {
 193                         min_match = cur_match->next;
 194                         free(cur_match);
 195                 }
 196                 clear_commit_marks(cmit, SEEN);
 197         }
 198 }
 199
 200 int cmd_describe(int argc, const char **argv, const char *prefix)
 201 {
 202         int i;
 203
 204         for (i = 1; i < argc; i++) {
 205                 const char *arg = argv[i];
 206
 207                 if (*arg != '-')
 208                         break;
 209                 else if (!strcmp(arg, "--all"))
 210                         all = 1;
 211                 else if (!strcmp(arg, "--tags"))
 212                         tags = 1;
 213                 else if (!strncmp(arg, "--abbrev=", 9)) {
 214                         abbrev = strtoul(arg + 9, NULL, 10);
 215                         if (abbrev < MINIMUM_ABBREV || 40 < abbrev)
 216                                 abbrev = DEFAULT_ABBREV;
 217                 }
 218                 else
 219                         usage(describe_usage);
 220         }
 221
 222         save_commit_buffer = 0;
 223
 224         if (argc <= i)
 225                 describe("HEAD", 1);
 226         else
 227                 while (i < argc) {
 228                         describe(argv[i], (i == argc - 1));
 229                         i++;
 230                 }
 231
 232         return 0;
 233 }