Merge branch 'gl/cleanup' into gl/cleanup-next
[git] / describe.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "tag.h"
4 #include "refs.h"
5
6 #define SEEN (1u << 0)
7
8 static const char describe_usage[] =
9 "git-describe [--all] [--tags] [--abbrev=<n>] <committish>*";
10
11 static int all; /* Default to annotated tags only */
12 static int tags;        /* But allow any tags if --tags is specified */
13
14 static int abbrev = DEFAULT_ABBREV;
15
16 static int names, allocs;
17 static 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
23 static 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
36 static 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
56 static int get_name(const char *path, const unsigned char *sha1)
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
88 static 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
100 static 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);
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
142 int 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         if (i == argc)
165                 describe("HEAD", 1);
166         else
167                 while (i < argc) {
168                         describe(argv[i], (i == argc - 1));
169                         i++;
170                 }
171
172         return 0;
173 }