Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "commit.h"
   3#include "tag.h"
   4#include "refs.h"
   5
   6#define SEEN (1u << 0)
   7
   8static const char describe_usage[] =
   9"git-describe [--all] [--tags] [--abbrev=<n>] <committish>*";
  10
  11static int all; /* Default to annotated tags only */
  12static int tags;        /* But allow any tags if --tags is specified */
  13
  14static int abbrev = DEFAULT_ABBREV;
  15
  16static int names, allocs;
  17static struct commit_name {
  18        const struct commit *commit;
  19        int prio; /* annotated tag = 2, tag = 1, head = 0 */
  20        char path[FLEX_ARRAY]; /* more */
  21} **name_array = NULL;
  22
  23static struct commit_name *match(struct commit *cmit)
  24{
  25        int i = names;
  26        struct commit_name **p = name_array;
  27
  28        while (i-- > 0) {
  29                struct commit_name *n = *p++;
  30                if (n->commit == cmit)
  31                        return n;
  32        }
  33        return NULL;
  34}
  35
  36static void add_to_known_names(const char *path,
  37                               const struct commit *commit,
  38                               int prio)
  39{
  40        int idx;
  41        int len = strlen(path)+1;
  42        struct commit_name *name = xmalloc(sizeof(struct commit_name) + len);
  43
  44        name->commit = commit;
  45        name->prio = prio;
  46        memcpy(name->path, path, len);
  47        idx = names;
  48        if (idx >= allocs) {
  49                allocs = (idx + 50) * 3 / 2;
  50                name_array = xrealloc(name_array, allocs*sizeof(*name_array));
  51        }
  52        name_array[idx] = name;
  53        names = ++idx;
  54}
  55
  56static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  57{
  58        struct commit *commit = lookup_commit_reference_gently(sha1, 1);
  59        struct object *object;
  60        int prio;
  61
  62        if (!commit)
  63                return 0;
  64        object = parse_object(sha1);
  65        /* If --all, then any refs are used.
  66         * If --tags, then any tags are used.
  67         * Otherwise only annotated tags are used.
  68         */
  69        if (!strncmp(path, "refs/tags/", 10)) {
  70                if (object->type == OBJ_TAG)
  71                        prio = 2;
  72                else
  73                        prio = 1;
  74        }
  75        else
  76                prio = 0;
  77
  78        if (!all) {
  79                if (!prio)
  80                        return 0;
  81                if (!tags && prio < 2)
  82                        return 0;
  83        }
  84        add_to_known_names(all ? path + 5 : path + 10, commit, prio);
  85        return 0;
  86}
  87
  88static int compare_names(const void *_a, const void *_b)
  89{
  90        struct commit_name *a = *(struct commit_name **)_a;
  91        struct commit_name *b = *(struct commit_name **)_b;
  92        unsigned long a_date = a->commit->date;
  93        unsigned long b_date = b->commit->date;
  94
  95        if (a->prio != b->prio)
  96                return b->prio - a->prio;
  97        return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
  98}
  99
 100static void describe(const char *arg, int last_one)
 101{
 102        unsigned char sha1[20];
 103        struct commit *cmit;
 104        struct commit_list *list;
 105        static int initialized = 0;
 106        struct commit_name *n;
 107
 108        if (get_sha1(arg, sha1))
 109                die("Not a valid object name %s", arg);
 110        cmit = lookup_commit_reference(sha1);
 111        if (!cmit)
 112                die("%s is not a valid '%s' object", arg, commit_type);
 113
 114        if (!initialized) {
 115                initialized = 1;
 116                for_each_ref(get_name, NULL);
 117                qsort(name_array, names, sizeof(*name_array), compare_names);
 118        }
 119
 120        n = match(cmit);
 121        if (n) {
 122                printf("%s\n", n->path);
 123                return;
 124        }
 125
 126        list = NULL;
 127        commit_list_insert(cmit, &list);
 128        while (list) {
 129                struct commit *c = pop_most_recent_commit(&list, SEEN);
 130                n = match(c);
 131                if (n) {
 132                        printf("%s-g%s\n", n->path,
 133                               find_unique_abbrev(cmit->object.sha1, abbrev));
 134                        if (!last_one)
 135                                clear_commit_marks(cmit, SEEN);
 136                        return;
 137                }
 138        }
 139        die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
 140}
 141
 142int main(int argc, char **argv)
 143{
 144        int i;
 145
 146        for (i = 1; i < argc; i++) {
 147                const char *arg = argv[i];
 148
 149                if (*arg != '-')
 150                        break;
 151                else if (!strcmp(arg, "--all"))
 152                        all = 1;
 153                else if (!strcmp(arg, "--tags"))
 154                        tags = 1;
 155                else if (!strncmp(arg, "--abbrev=", 9)) {
 156                        abbrev = strtoul(arg + 9, NULL, 10);
 157                        if (abbrev < MINIMUM_ABBREV || 40 < abbrev)
 158                                abbrev = DEFAULT_ABBREV;
 159                }
 160                else
 161                        usage(describe_usage);
 162        }
 163
 164        setup_git_directory();
 165
 166        if (argc <= i)
 167                describe("HEAD", 1);
 168        else
 169                while (i < argc) {
 170                        describe(argv[i], (i == argc - 1));
 171                        i++;
 172                }
 173
 174        return 0;
 175}