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 /*
 210  * We cannot decide in this function whether we are in the work tree or
 211  * not, since the config can only be read _after_ this function was called.
 212  */
 213 const char *setup_git_directory_gently(int *nongit_ok)
 214 {
 215         const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 216         static char cwd[PATH_MAX+1];
 217         const char *gitdirenv;
 218         int len, offset;
 219
 220         /*
 221          * If GIT_DIR is set explicitly, we're not going
 222          * to do any discovery, but we still do repository
 223          * validation.
 224          */
 225         gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 226         if (gitdirenv) {
 227                 if (PATH_MAX - 40 < strlen(gitdirenv))
 228                         die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 229                 if (is_git_directory(gitdirenv)) {
 230                         if (!work_tree_env)
 231                                 return set_work_tree(gitdirenv);
 232                         return NULL;
 233                 }
 234                 if (nongit_ok) {
 235                         *nongit_ok = 1;
 236                         return NULL;
 237                 }
 238                 die("Not a git repository: '%s'", gitdirenv);
 239         }
 240
 241         if (!getcwd(cwd, sizeof(cwd)-1))
 242                 die("Unable to read current working directory");
 243
 244         /*
 245          * Test in the following order (relative to the cwd):
 246          * - .git/
 247          * - ./ (bare)
 248          * - ../.git/
 249          * - ../ (bare)
 250          * - ../../.git/
 251          *   etc.
 252          */
 253         offset = len = strlen(cwd);
 254         for (;;) {
 255                 if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 256                         break;
 257                 if (is_git_directory(".")) {
 258                         inside_git_dir = 1;
 259                         if (!work_tree_env)
 260                                 inside_work_tree = 0;
 261                         setenv(GIT_DIR_ENVIRONMENT, ".", 1);
 262                         return NULL;
 263                 }
 264                 chdir("..");
 265                 do {
 266                         if (!offset) {
 267                                 if (nongit_ok) {
 268                                         if (chdir(cwd))
 269                                                 die("Cannot come back to cwd");
 270                                         *nongit_ok = 1;
 271                                         return NULL;
 272                                 }
 273                                 die("Not a git repository");
 274                         }
 275                 } while (cwd[--offset] != '/');
 276         }
 277
 278         inside_git_dir = 0;
 279         if (!work_tree_env)
 280                 inside_work_tree = 1;
 281         git_work_tree_cfg = xstrndup(cwd, offset);
 282         if (offset == len)
 283                 return NULL;
 284
 285         /* Make "offset" point to past the '/', and add a '/' at the end */
 286         offset++;
 287         cwd[len++] = '/';
 288         cwd[len] = 0;
 289         return cwd + offset;
 290 }
 291
 292 int git_config_perm(const char *var, const char *value)
 293 {
 294         if (value) {
 295                 int i;
 296                 if (!strcmp(value, "umask"))
 297                         return PERM_UMASK;
 298                 if (!strcmp(value, "group"))
 299                         return PERM_GROUP;
 300                 if (!strcmp(value, "all") ||
 301                     !strcmp(value, "world") ||
 302                     !strcmp(value, "everybody"))
 303                         return PERM_EVERYBODY;
 304                 i = atoi(value);
 305                 if (i > 1)
 306                         return i;
 307         }
 308         return git_config_bool(var, value);
 309 }
 310
 311 int check_repository_format_version(const char *var, const char *value)
 312 {
 313         if (strcmp(var, "core.repositoryformatversion") == 0)
 314                 repository_format_version = git_config_int(var, value);
 315         else if (strcmp(var, "core.sharedrepository") == 0)
 316                 shared_repository = git_config_perm(var, value);
 317         else if (strcmp(var, "core.bare") == 0) {
 318                 is_bare_repository_cfg = git_config_bool(var, value);
 319                 if (is_bare_repository_cfg == 1)
 320                         inside_work_tree = -1;
 321         } else if (strcmp(var, "core.worktree") == 0) {
 322                 if (git_work_tree_cfg)
 323                         free(git_work_tree_cfg);
 324                 git_work_tree_cfg = xstrdup(value);
 325                 inside_work_tree = -1;
 326         }
 327         return 0;
 328 }
 329
 330 int check_repository_format(void)
 331 {
 332         git_config(check_repository_format_version);
 333         if (GIT_REPO_VERSION < repository_format_version)
 334                 die ("Expected git repo version <= %d, found %d",
 335                      GIT_REPO_VERSION, repository_format_version);
 336         return 0;
 337 }
 338
 339 const char *setup_git_directory(void)
 340 {
 341         const char *retval = setup_git_directory_gently(NULL);
 342         check_repository_format();
 343
 344         /* If the work tree is not the default one, recompute prefix */
 345         if (inside_work_tree < 0) {
 346                 static char buffer[PATH_MAX + 1];
 347                 char *rel;
 348                 if (retval && chdir(retval))
 349                         die ("Could not jump back into original cwd");
 350                 rel = get_relative_cwd(buffer, PATH_MAX, get_git_work_tree());
 351                 return rel && *rel ? strcat(rel, "/") : NULL;
 352         }
 353
 354         return retval;
 355 }