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 /*
  66  * Verify a filename that we got as an argument for a pathspec
  67  * entry. Note that a filename that begins with "-" never verifies
  68  * as true, because even if such a filename were to exist, we want
  69  * it to be preceded by the "--" marker (or we want the user to
  70  * use a format like "./-filename")
  71  */
  72 void verify_filename(const char *prefix, const char *arg)
  73 {
  74         const char *name;
  75         struct stat st;
  76
  77         if (*arg == '-')
  78                 die("bad flag '%s' used after filename", arg);
  79         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
  80         if (!lstat(name, &st))
  81                 return;
  82         if (errno == ENOENT)
  83                 die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
  84                     "Use '--' to separate paths from revisions", arg);
  85         die("'%s': %s", arg, strerror(errno));
  86 }
  87
  88 /*
  89  * Opposite of the above: the command line did not have -- marker
  90  * and we parsed the arg as a refname.  It should not be interpretable
  91  * as a filename.
  92  */
  93 void verify_non_filename(const char *prefix, const char *arg)
  94 {
  95         const char *name;
  96         struct stat st;
  97
  98         if (*arg == '-')
  99                 return; /* flag */
 100         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
 101         if (!lstat(name, &st))
 102                 die("ambiguous argument '%s': both revision and filename\n"
 103                     "Use '--' to separate filenames from revisions", arg);
 104         if (errno != ENOENT)
 105                 die("'%s': %s", arg, strerror(errno));
 106 }
 107
 108 const char **get_pathspec(const char *prefix, const char **pathspec)
 109 {
 110         const char *entry = *pathspec;
 111         const char **p;
 112         int prefixlen;
 113
 114         if (!prefix && !entry)
 115                 return NULL;
 116
 117         if (!entry) {
 118                 static const char *spec[2];
 119                 spec[0] = prefix;
 120                 spec[1] = NULL;
 121                 return spec;
 122         }
 123
 124         /* Otherwise we have to re-write the entries.. */
 125         p = pathspec;
 126         prefixlen = prefix ? strlen(prefix) : 0;
 127         do {
 128                 *p = prefix_path(prefix, prefixlen, entry);
 129         } while ((entry = *++p) != NULL);
 130         return (const char **) pathspec;
 131 }
 132
 133 /*
 134  * Test if it looks like we're at a git directory.
 135  * We want to see:
 136  *
 137  *  - either a objects/ directory _or_ the proper
 138  *    GIT_OBJECT_DIRECTORY environment variable
 139  *  - a refs/ directory
 140  *  - either a HEAD symlink or a HEAD file that is formatted as
 141  *    a proper "ref:".
 142  */
 143 static int is_git_directory(const char *suspect)
 144 {
 145         char path[PATH_MAX];
 146         size_t len = strlen(suspect);
 147
 148         strcpy(path, suspect);
 149         if (getenv(DB_ENVIRONMENT)) {
 150                 if (access(getenv(DB_ENVIRONMENT), X_OK))
 151                         return 0;
 152         }
 153         else {
 154                 strcpy(path + len, "/objects");
 155                 if (access(path, X_OK))
 156                         return 0;
 157         }
 158
 159         strcpy(path + len, "/refs");
 160         if (access(path, X_OK))
 161                 return 0;
 162
 163         strcpy(path + len, "/HEAD");
 164         if (validate_symref(path))
 165                 return 0;
 166
 167         return 1;
 168 }
 169
 170 const char *setup_git_directory_gently(int *nongit_ok)
 171 {
 172         static char cwd[PATH_MAX+1];
 173         const char *gitdirenv;
 174         int len, offset;
 175
 176         /*
 177          * If GIT_DIR is set explicitly, we're not going
 178          * to do any discovery, but we still do repository
 179          * validation.
 180          */
 181         gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 182         if (gitdirenv) {
 183                 if (PATH_MAX - 40 < strlen(gitdirenv))
 184                         die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 185                 if (is_git_directory(gitdirenv))
 186                         return NULL;
 187                 if (nongit_ok) {
 188                         *nongit_ok = 1;
 189                         return NULL;
 190                 }
 191                 die("Not a git repository: '%s'", gitdirenv);
 192         }
 193
 194         if (!getcwd(cwd, sizeof(cwd)) || cwd[0] != '/')
 195                 die("Unable to read current working directory");
 196
 197         offset = len = strlen(cwd);
 198         for (;;) {
 199                 if (is_git_directory(".git"))
 200                         break;
 201                 chdir("..");
 202                 do {
 203                         if (!offset) {
 204                                 if (is_git_directory(cwd)) {
 205                                         if (chdir(cwd))
 206                                                 die("Cannot come back to cwd");
 207                                         setenv(GIT_DIR_ENVIRONMENT, cwd, 1);
 208                                         return NULL;
 209                                 }
 210                                 if (nongit_ok) {
 211                                         if (chdir(cwd))
 212                                                 die("Cannot come back to cwd");
 213                                         *nongit_ok = 1;
 214                                         return NULL;
 215                                 }
 216                                 die("Not a git repository");
 217                         }
 218                 } while (cwd[--offset] != '/');
 219         }
 220
 221         if (offset == len)
 222                 return NULL;
 223
 224         /* Make "offset" point to past the '/', and add a '/' at the end */
 225         offset++;
 226         cwd[len++] = '/';
 227         cwd[len] = 0;
 228         return cwd + offset;
 229 }
 230
 231 int git_config_perm(const char *var, const char *value)
 232 {
 233         if (value) {
 234                 if (!strcmp(value, "umask"))
 235                         return PERM_UMASK;
 236                 if (!strcmp(value, "group"))
 237                         return PERM_GROUP;
 238                 if (!strcmp(value, "all") ||
 239                     !strcmp(value, "world") ||
 240                     !strcmp(value, "everybody"))
 241                         return PERM_EVERYBODY;
 242         }
 243         return git_config_bool(var, value);
 244 }
 245
 246 int check_repository_format_version(const char *var, const char *value)
 247 {
 248        if (strcmp(var, "core.repositoryformatversion") == 0)
 249                repository_format_version = git_config_int(var, value);
 250         else if (strcmp(var, "core.sharedrepository") == 0)
 251                 shared_repository = git_config_perm(var, value);
 252        return 0;
 253 }
 254
 255 int check_repository_format(void)
 256 {
 257         git_config(check_repository_format_version);
 258         if (GIT_REPO_VERSION < repository_format_version)
 259                 die ("Expected git repo version <= %d, found %d",
 260                      GIT_REPO_VERSION, repository_format_version);
 261         return 0;
 262 }
 263
 264 const char *setup_git_directory(void)
 265 {
 266         const char *retval = setup_git_directory_gently(NULL);
 267         check_repository_format();
 268         return retval;
 269 }