Refactor working tree setup
[git/git.git] / setup.c
1 #include "cache.h"
2 #include "dir.h"
3
4 static int inside_git_dir = -1;
5 static int inside_work_tree = -1;
6
7 const char *prefix_path(const char *prefix, int len, const char *path)
8 {
9 const char *orig = path;
10 for (;;) {
11 char c;
12 if (*path != '.')
13 break;
14 c = path[1];
15 /* "." */
16 if (!c) {
17 path++;
18 break;
19 }
20 /* "./" */
21 if (c == '/') {
22 path += 2;
23 continue;
24 }
25 if (c != '.')
26 break;
27 c = path[2];
28 if (!c)
29 path += 2;
30 else if (c == '/')
31 path += 3;
32 else
33 break;
34 /* ".." and "../" */
35 /* Remove last component of the prefix */
36 do {
37 if (!len)
38 die("'%s' is outside repository", orig);
39 len--;
40 } while (len && prefix[len-1] != '/');
41 continue;
42 }
43 if (len) {
44 int speclen = strlen(path);
45 char *n = xmalloc(speclen + len + 1);
46
47 memcpy(n, prefix, len);
48 memcpy(n + len, path, speclen+1);
49 path = n;
50 }
51 return path;
52 }
53
54 /*
55 * Unlike prefix_path, this should be used if the named file does
56 * not have to interact with index entry; i.e. name of a random file
57 * on the filesystem.
58 */
59 const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
60 {
61 static char path[PATH_MAX];
62 if (!pfx || !*pfx || arg[0] == '/')
63 return arg;
64 memcpy(path, pfx, pfx_len);
65 strcpy(path + pfx_len, arg);
66 return path;
67 }
68
69 /*
70 * Verify a filename that we got as an argument for a pathspec
71 * entry. Note that a filename that begins with "-" never verifies
72 * as true, because even if such a filename were to exist, we want
73 * it to be preceded by the "--" marker (or we want the user to
74 * use a format like "./-filename")
75 */
76 void verify_filename(const char *prefix, const char *arg)
77 {
78 const char *name;
79 struct stat st;
80
81 if (*arg == '-')
82 die("bad flag '%s' used after filename", arg);
83 name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
84 if (!lstat(name, &st))
85 return;
86 if (errno == ENOENT)
87 die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
88 "Use '--' to separate paths from revisions", arg);
89 die("'%s': %s", arg, strerror(errno));
90 }
91
92 /*
93 * Opposite of the above: the command line did not have -- marker
94 * and we parsed the arg as a refname. It should not be interpretable
95 * as a filename.
96 */
97 void verify_non_filename(const char *prefix, const char *arg)
98 {
99 const char *name;
100 struct stat st;
101
102 if (!is_inside_work_tree() || is_inside_git_dir())
103 return;
104 if (*arg == '-')
105 return; /* flag */
106 name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
107 if (!lstat(name, &st))
108 die("ambiguous argument '%s': both revision and filename\n"
109 "Use '--' to separate filenames from revisions", arg);
110 if (errno != ENOENT && errno != ENOTDIR)
111 die("'%s': %s", arg, strerror(errno));
112 }
113
114 const char **get_pathspec(const char *prefix, const char **pathspec)
115 {
116 const char *entry = *pathspec;
117 const char **p;
118 int prefixlen;
119
120 if (!prefix && !entry)
121 return NULL;
122
123 if (!entry) {
124 static const char *spec[2];
125 spec[0] = prefix;
126 spec[1] = NULL;
127 return spec;
128 }
129
130 /* Otherwise we have to re-write the entries.. */
131 p = pathspec;
132 prefixlen = prefix ? strlen(prefix) : 0;
133 do {
134 *p = prefix_path(prefix, prefixlen, entry);
135 } while ((entry = *++p) != NULL);
136 return (const char **) pathspec;
137 }
138
139 /*
140 * Test if it looks like we're at a git directory.
141 * We want to see:
142 *
143 * - either a objects/ directory _or_ the proper
144 * GIT_OBJECT_DIRECTORY environment variable
145 * - a refs/ directory
146 * - either a HEAD symlink or a HEAD file that is formatted as
147 * a proper "ref:", or a regular file HEAD that has a properly
148 * formatted sha1 object name.
149 */
150 static int is_git_directory(const char *suspect)
151 {
152 char path[PATH_MAX];
153 size_t len = strlen(suspect);
154
155 strcpy(path, suspect);
156 if (getenv(DB_ENVIRONMENT)) {
157 if (access(getenv(DB_ENVIRONMENT), X_OK))
158 return 0;
159 }
160 else {
161 strcpy(path + len, "/objects");
162 if (access(path, X_OK))
163 return 0;
164 }
165
166 strcpy(path + len, "/refs");
167 if (access(path, X_OK))
168 return 0;
169
170 strcpy(path + len, "/HEAD");
171 if (validate_headref(path))
172 return 0;
173
174 return 1;
175 }
176
177 int is_inside_git_dir(void)
178 {
179 if (inside_git_dir < 0)
180 inside_git_dir = is_inside_dir(get_git_dir());
181 return inside_git_dir;
182 }
183
184 int is_inside_work_tree(void)
185 {
186 if (inside_work_tree < 0)
187 inside_work_tree = is_inside_dir(get_git_work_tree());
188 return inside_work_tree;
189 }
190
191 /*
192 * set_work_tree() is only ever called if you set GIT_DIR explicitely.
193 * The old behaviour (which we retain here) is to set the work tree root
194 * to the cwd, unless overridden by the config, the command line, or
195 * GIT_WORK_TREE.
196 */
197 static const char *set_work_tree(const char *dir)
198 {
199 char buffer[PATH_MAX + 1];
200
201 if (!getcwd(buffer, sizeof(buffer)))
202 die ("Could not get the current working directory");
203 git_work_tree_cfg = xstrdup(buffer);
204 inside_work_tree = 1;
205
206 return NULL;
207 }
208
209 void setup_work_tree(void) {
210 const char *work_tree = get_git_work_tree();
211 const char *git_dir = get_git_dir();
212 if (!is_absolute_path(git_dir))
213 set_git_dir(make_absolute_path(git_dir));
214 if (!work_tree || chdir(work_tree))
215 die("This operation must be run in a work tree");
216 }
217
218 /*
219 * We cannot decide in this function whether we are in the work tree or
220 * not, since the config can only be read _after_ this function was called.
221 */
222 const char *setup_git_directory_gently(int *nongit_ok)
223 {
224 const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
225 static char cwd[PATH_MAX+1];
226 const char *gitdirenv;
227 int len, offset;
228
229 /*
230 * If GIT_DIR is set explicitly, we're not going
231 * to do any discovery, but we still do repository
232 * validation.
233 */
234 gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
235 if (gitdirenv) {
236 if (PATH_MAX - 40 < strlen(gitdirenv))
237 die("'$%s' too big", GIT_DIR_ENVIRONMENT);
238 if (is_git_directory(gitdirenv)) {
239 static char buffer[1024 + 1];
240 const char *retval;
241
242 if (!work_tree_env)
243 return set_work_tree(gitdirenv);
244 retval = get_relative_cwd(buffer, sizeof(buffer) - 1,
245 get_git_work_tree());
246 if (!retval || !*retval)
247 return NULL;
248 set_git_dir(make_absolute_path(gitdirenv));
249 if (chdir(work_tree_env) < 0)
250 die ("Could not chdir to %s", work_tree_env);
251 strcat(buffer, "/");
252 return retval;
253 }
254 if (nongit_ok) {
255 *nongit_ok = 1;
256 return NULL;
257 }
258 die("Not a git repository: '%s'", gitdirenv);
259 }
260
261 if (!getcwd(cwd, sizeof(cwd)-1))
262 die("Unable to read current working directory");
263
264 /*
265 * Test in the following order (relative to the cwd):
266 * - .git/
267 * - ./ (bare)
268 * - ../.git/
269 * - ../ (bare)
270 * - ../../.git/
271 * etc.
272 */
273 offset = len = strlen(cwd);
274 for (;;) {
275 if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
276 break;
277 if (is_git_directory(".")) {
278 inside_git_dir = 1;
279 if (!work_tree_env)
280 inside_work_tree = 0;
281 setenv(GIT_DIR_ENVIRONMENT, ".", 1);
282 return NULL;
283 }
284 chdir("..");
285 do {
286 if (!offset) {
287 if (nongit_ok) {
288 if (chdir(cwd))
289 die("Cannot come back to cwd");
290 *nongit_ok = 1;
291 return NULL;
292 }
293 die("Not a git repository");
294 }
295 } while (cwd[--offset] != '/');
296 }
297
298 inside_git_dir = 0;
299 if (!work_tree_env)
300 inside_work_tree = 1;
301 git_work_tree_cfg = xstrndup(cwd, offset);
302 if (offset == len)
303 return NULL;
304
305 /* Make "offset" point to past the '/', and add a '/' at the end */
306 offset++;
307 cwd[len++] = '/';
308 cwd[len] = 0;
309 return cwd + offset;
310 }
311
312 int git_config_perm(const char *var, const char *value)
313 {
314 if (value) {
315 int i;
316 if (!strcmp(value, "umask"))
317 return PERM_UMASK;
318 if (!strcmp(value, "group"))
319 return PERM_GROUP;
320 if (!strcmp(value, "all") ||
321 !strcmp(value, "world") ||
322 !strcmp(value, "everybody"))
323 return PERM_EVERYBODY;
324 i = atoi(value);
325 if (i > 1)
326 return i;
327 }
328 return git_config_bool(var, value);
329 }
330
331 int check_repository_format_version(const char *var, const char *value)
332 {
333 if (strcmp(var, "core.repositoryformatversion") == 0)
334 repository_format_version = git_config_int(var, value);
335 else if (strcmp(var, "core.sharedrepository") == 0)
336 shared_repository = git_config_perm(var, value);
337 else if (strcmp(var, "core.bare") == 0) {
338 is_bare_repository_cfg = git_config_bool(var, value);
339 if (is_bare_repository_cfg == 1)
340 inside_work_tree = -1;
341 } else if (strcmp(var, "core.worktree") == 0) {
342 if (git_work_tree_cfg)
343 free(git_work_tree_cfg);
344 git_work_tree_cfg = xstrdup(value);
345 inside_work_tree = -1;
346 }
347 return 0;
348 }
349
350 int check_repository_format(void)
351 {
352 git_config(check_repository_format_version);
353 if (GIT_REPO_VERSION < repository_format_version)
354 die ("Expected git repo version <= %d, found %d",
355 GIT_REPO_VERSION, repository_format_version);
356 return 0;
357 }
358
359 const char *setup_git_directory(void)
360 {
361 const char *retval = setup_git_directory_gently(NULL);
362 check_repository_format();
363
364 /* If the work tree is not the default one, recompute prefix */
365 if (inside_work_tree < 0) {
366 static char buffer[PATH_MAX + 1];
367 char *rel;
368 if (retval && chdir(retval))
369 die ("Could not jump back into original cwd");
370 rel = get_relative_cwd(buffer, PATH_MAX, get_git_work_tree());
371 return rel && *rel ? strcat(rel, "/") : NULL;
372 }
373
374 return retval;
375 }