Merge branch 'sp/checkout'
[git] / setup.c
1 #include "cache.h"
2
3 const char *prefix_path(const char *prefix, int len, const char *path)
4 {
5         const char *orig = path;
6         for (;;) {
7                 char c;
8                 if (*path != '.')
9                         break;
10                 c = path[1];
11                 /* "." */
12                 if (!c) {
13                         path++;
14                         break;
15                 }
16                 /* "./" */
17                 if (c == '/') {
18                         path += 2;
19                         continue;
20                 }
21                 if (c != '.')
22                         break;
23                 c = path[2];
24                 if (!c)
25                         path += 2;
26                 else if (c == '/')
27                         path += 3;
28                 else
29                         break;
30                 /* ".." and "../" */
31                 /* Remove last component of the prefix */
32                 do {
33                         if (!len)
34                                 die("'%s' is outside repository", orig);
35                         len--;
36                 } while (len && prefix[len-1] != '/');
37                 continue;
38         }
39         if (len) {
40                 int speclen = strlen(path);
41                 char *n = xmalloc(speclen + len + 1);
42         
43                 memcpy(n, prefix, len);
44                 memcpy(n + len, path, speclen+1);
45                 path = n;
46         }
47         return path;
48 }
49
50 /* 
51  * Unlike prefix_path, this should be used if the named file does
52  * not have to interact with index entry; i.e. name of a random file
53  * on the filesystem.
54  */
55 const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
56 {
57         static char path[PATH_MAX];
58         if (!pfx || !*pfx || arg[0] == '/')
59                 return arg;
60         memcpy(path, pfx, pfx_len);
61         strcpy(path + pfx_len, arg);
62         return path;
63 }
64
65 const char **get_pathspec(const char *prefix, const char **pathspec)
66 {
67         const char *entry = *pathspec;
68         const char **p;
69         int prefixlen;
70
71         if (!prefix && !entry)
72                 return NULL;
73
74         if (!entry) {
75                 static const char *spec[2];
76                 spec[0] = prefix;
77                 spec[1] = NULL;
78                 return spec;
79         }
80
81         /* Otherwise we have to re-write the entries.. */
82         p = pathspec;
83         prefixlen = prefix ? strlen(prefix) : 0;
84         do {
85                 *p = prefix_path(prefix, prefixlen, entry);
86         } while ((entry = *++p) != NULL);
87         return (const char **) pathspec;
88 }
89
90 /*
91  * Test if it looks like we're at the top level git directory.
92  * We want to see:
93  *
94  *  - either a .git/objects/ directory _or_ the proper
95  *    GIT_OBJECT_DIRECTORY environment variable
96  *  - a refs/ directory under ".git"
97  *  - either a HEAD symlink or a HEAD file that is formatted as
98  *    a proper "ref:".
99  */
100 static int is_toplevel_directory(void)
101 {
102         if (access(".git/refs/", X_OK) ||
103             access(getenv(DB_ENVIRONMENT) ?
104                    getenv(DB_ENVIRONMENT) : ".git/objects/", X_OK) ||
105             validate_symref(".git/HEAD"))
106                 return 0;
107         return 1;
108 }
109
110 const char *setup_git_directory_gently(int *nongit_ok)
111 {
112         static char cwd[PATH_MAX+1];
113         int len, offset;
114
115         /*
116          * If GIT_DIR is set explicitly, we're not going
117          * to do any discovery, but we still do repository
118          * validation.
119          */
120         if (getenv(GIT_DIR_ENVIRONMENT)) {
121                 char path[PATH_MAX];
122                 int len = strlen(getenv(GIT_DIR_ENVIRONMENT));
123                 if (sizeof(path) - 40 < len)
124                         die("'$%s' too big", GIT_DIR_ENVIRONMENT);
125                 memcpy(path, getenv(GIT_DIR_ENVIRONMENT), len);
126                 
127                 strcpy(path + len, "/refs");
128                 if (access(path, X_OK))
129                         goto bad_dir_environ;
130                 strcpy(path + len, "/HEAD");
131                 if (validate_symref(path))
132                         goto bad_dir_environ;
133                 if (getenv(DB_ENVIRONMENT)) {
134                         if (access(getenv(DB_ENVIRONMENT), X_OK))
135                                 goto bad_dir_environ;
136                 }
137                 else {
138                         strcpy(path + len, "/objects");
139                         if (access(path, X_OK))
140                                 goto bad_dir_environ;
141                 }
142                 return NULL;
143         bad_dir_environ:
144                 path[len] = 0;
145                 die("Not a git repository: '%s'", path);
146         }
147
148         if (!getcwd(cwd, sizeof(cwd)) || cwd[0] != '/')
149                 die("Unable to read current working directory");
150
151         offset = len = strlen(cwd);
152         for (;;) {
153                 if (is_toplevel_directory())
154                         break;
155                 chdir("..");
156                 do {
157                         if (!offset) {
158                                 if (nongit_ok) {
159                                         if (chdir(cwd))
160                                                 die("Cannot come back to cwd");
161                                         *nongit_ok = 1;
162                                         return NULL;
163                                 }
164                                 die("Not a git repository");
165                         }
166                 } while (cwd[--offset] != '/');
167         }
168
169         if (offset == len)
170                 return NULL;
171
172         /* Make "offset" point to past the '/', and add a '/' at the end */
173         offset++;
174         cwd[len++] = '/';
175         cwd[len] = 0;
176         return cwd + offset;
177 }
178
179 int check_repository_format_version(const char *var, const char *value)
180 {
181        if (strcmp(var, "core.repositoryformatversion") == 0)
182                repository_format_version = git_config_int(var, value);
183         else if (strcmp(var, "core.sharedrepository") == 0)
184                 shared_repository = git_config_bool(var, value);
185        return 0;
186 }
187
188 int check_repository_format(void)
189 {
190         git_config(check_repository_format_version);
191         if (GIT_REPO_VERSION < repository_format_version)
192                 die ("Expected git repo version <= %d, found %d",
193                      GIT_REPO_VERSION, repository_format_version);
194         return 0;
195 }
196
197 const char *setup_git_directory(void)
198 {
199         const char *retval = setup_git_directory_gently(NULL);
200         check_repository_format();
201         return retval;
202 }