Merge branch 'fix'
[git/git.git] / describe.c
CommitLineData
908e5310
LT
1#include "cache.h"
2#include "commit.h"
635d4134 3#include "tag.h"
908e5310
LT
4#include "refs.h"
5
6#define SEEN (1u << 0)
7
2d9e7c9f
JH
8static const char describe_usage[] =
9"git-describe [--all] [--tags] [--abbrev=<n>] <committish>*";
908e5310 10
635d4134 11static int all = 0; /* Default to annotated tags only */
2d9e7c9f
JH
12static int tags = 0; /* But allow any tags if --tags is specified */
13
14#define DEFAULT_ABBREV 8 /* maybe too many */
15static int abbrev = DEFAULT_ABBREV;
908e5310
LT
16
17static int names = 0, allocs = 0;
18static struct commit_name {
19 const struct commit *commit;
64deb858 20 int prio; /* annotated tag = 2, tag = 1, head = 0 */
5a2282de 21 char path[FLEX_ARRAY]; /* more */
908e5310
LT
22} **name_array = NULL;
23
24static struct commit_name *match(struct commit *cmit)
25{
26 int i = names;
27 struct commit_name **p = name_array;
28
29 while (i-- > 0) {
30 struct commit_name *n = *p++;
31 if (n->commit == cmit)
32 return n;
33 }
34 return NULL;
35}
36
64deb858
JH
37static void add_to_known_names(const char *path,
38 const struct commit *commit,
39 int prio)
908e5310
LT
40{
41 int idx;
42 int len = strlen(path)+1;
43 struct commit_name *name = xmalloc(sizeof(struct commit_name) + len);
44
45 name->commit = commit;
64deb858 46 name->prio = prio;
908e5310
LT
47 memcpy(name->path, path, len);
48 idx = names;
49 if (idx >= allocs) {
50 allocs = (idx + 50) * 3 / 2;
51 name_array = xrealloc(name_array, allocs*sizeof(*name_array));
52 }
53 name_array[idx] = name;
54 names = ++idx;
55}
56
57static int get_name(const char *path, const unsigned char *sha1)
58{
59 struct commit *commit = lookup_commit_reference_gently(sha1, 1);
64deb858
JH
60 struct object *object;
61 int prio;
62
908e5310
LT
63 if (!commit)
64 return 0;
64deb858 65 object = parse_object(sha1);
2d9e7c9f
JH
66 /* If --all, then any refs are used.
67 * If --tags, then any tags are used.
68 * Otherwise only annotated tags are used.
69 */
64deb858
JH
70 if (!strncmp(path, "refs/tags/", 10)) {
71 if (object->type == tag_type)
72 prio = 2;
73 else
74 prio = 1;
75 }
76 else
77 prio = 0;
78
635d4134 79 if (!all) {
64deb858
JH
80 if (!prio)
81 return 0;
82 if (!tags && prio < 2)
635d4134 83 return 0;
635d4134 84 }
64deb858 85 add_to_known_names(all ? path + 5 : path + 10, commit, prio);
908e5310
LT
86 return 0;
87}
88
89static int compare_names(const void *_a, const void *_b)
90{
91 struct commit_name *a = *(struct commit_name **)_a;
92 struct commit_name *b = *(struct commit_name **)_b;
93 unsigned long a_date = a->commit->date;
94 unsigned long b_date = b->commit->date;
64deb858
JH
95
96 if (a->prio != b->prio)
97 return b->prio - a->prio;
908e5310
LT
98 return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
99}
100
4c34a2c5 101static void describe(char *arg)
908e5310 102{
4c34a2c5
JH
103 unsigned char sha1[20];
104 struct commit *cmit;
908e5310
LT
105 struct commit_list *list;
106 static int initialized = 0;
107 struct commit_name *n;
108
4c34a2c5
JH
109 if (get_sha1(arg, sha1) < 0)
110 usage(describe_usage);
111 cmit = lookup_commit_reference(sha1);
112 if (!cmit)
113 usage(describe_usage);
114
908e5310
LT
115 if (!initialized) {
116 initialized = 1;
117 for_each_ref(get_name);
118 qsort(name_array, names, sizeof(*name_array), compare_names);
119 }
120
121 n = match(cmit);
122 if (n) {
123 printf("%s\n", n->path);
124 return;
125 }
126
127 list = NULL;
128 commit_list_insert(cmit, &list);
129 while (list) {
130 struct commit *c = pop_most_recent_commit(&list, SEEN);
131 n = match(c);
132 if (n) {
4cdf78bf 133 printf("%s-g%s\n", n->path,
2d9e7c9f 134 find_unique_abbrev(cmit->object.sha1, abbrev));
8c23b6fa
JH
135 clear_commit_marks(cmit, SEEN);
136 return;
908e5310
LT
137 }
138 }
8c23b6fa 139 die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
908e5310
LT
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];
908e5310 148
4c34a2c5
JH
149 if (*arg != '-')
150 break;
151 else if (!strcmp(arg, "--all"))
908e5310 152 all = 1;
4c34a2c5 153 else if (!strcmp(arg, "--tags"))
2d9e7c9f 154 tags = 1;
4c34a2c5 155 else if (!strncmp(arg, "--abbrev=", 9)) {
2d9e7c9f
JH
156 abbrev = strtoul(arg + 9, NULL, 10);
157 if (abbrev < 4 || 40 <= abbrev)
158 abbrev = DEFAULT_ABBREV;
2d9e7c9f 159 }
4c34a2c5 160 else
908e5310 161 usage(describe_usage);
908e5310 162 }
4c34a2c5
JH
163
164 if (i == argc)
165 describe("HEAD");
166 else
167 while (i < argc)
168 describe(argv[i++]);
169
908e5310
LT
170 return 0;
171}