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 filename\n"
  84                     "Use '--' to separate filenames from revisions", arg);
  85         die("'%s': %s", arg, strerror(errno));
  86 }
  87
  88 const char **get_pathspec(const char *prefix, const char **pathspec)
  89 {
  90         const char *entry = *pathspec;
  91         const char **p;
  92         int prefixlen;
  93
  94         if (!prefix && !entry)
  95                 return NULL;
  96
  97         if (!entry) {
  98                 static const char *spec[2];
  99                 spec[0] = prefix;
 100                 spec[1] = NULL;
 101                 return spec;
 102         }
 103
 104         /* Otherwise we have to re-write the entries.. */
 105         p = pathspec;
 106         prefixlen = prefix ? strlen(prefix) : 0;
 107         do {
 108                 *p = prefix_path(prefix, prefixlen, entry);
 109         } while ((entry = *++p) != NULL);
 110         return (const char **) pathspec;
 111 }
 112
 113 /*
 114  * Test if it looks like we're at the top level git directory.
 115  * We want to see:
 116  *
 117  *  - either a .git/objects/ directory _or_ the proper
 118  *    GIT_OBJECT_DIRECTORY environment variable
 119  *  - a refs/ directory under ".git"
 120  *  - either a HEAD symlink or a HEAD file that is formatted as
 121  *    a proper "ref:".
 122  */
 123 static int is_toplevel_directory(void)
 124 {
 125         if (access(".git/refs/", X_OK) ||
 126             access(getenv(DB_ENVIRONMENT) ?
 127                    getenv(DB_ENVIRONMENT) : ".git/objects/", X_OK) ||
 128             validate_symref(".git/HEAD"))
 129                 return 0;
 130         return 1;
 131 }
 132
 133 const char *setup_git_directory_gently(int *nongit_ok)
 134 {
 135         static char cwd[PATH_MAX+1];
 136         int len, offset;
 137
 138         /*
 139          * If GIT_DIR is set explicitly, we're not going
 140          * to do any discovery, but we still do repository
 141          * validation.
 142          */
 143         if (getenv(GIT_DIR_ENVIRONMENT)) {
 144                 char path[PATH_MAX];
 145                 int len = strlen(getenv(GIT_DIR_ENVIRONMENT));
 146                 if (sizeof(path) - 40 < len)
 147                         die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 148                 memcpy(path, getenv(GIT_DIR_ENVIRONMENT), len);
 149
 150                 strcpy(path + len, "/refs");
 151                 if (access(path, X_OK))
 152                         goto bad_dir_environ;
 153                 strcpy(path + len, "/HEAD");
 154                 if (validate_symref(path))
 155                         goto bad_dir_environ;
 156                 if (getenv(DB_ENVIRONMENT)) {
 157                         if (access(getenv(DB_ENVIRONMENT), X_OK))
 158                                 goto bad_dir_environ;
 159                 }
 160                 else {
 161                         strcpy(path + len, "/objects");
 162                         if (access(path, X_OK))
 163                                 goto bad_dir_environ;
 164                 }
 165                 return NULL;
 166         bad_dir_environ:
 167                 path[len] = 0;
 168                 die("Not a git repository: '%s'", path);
 169         }
 170
 171         if (!getcwd(cwd, sizeof(cwd)) || cwd[0] != '/')
 172                 die("Unable to read current working directory");
 173
 174         offset = len = strlen(cwd);
 175         for (;;) {
 176                 if (is_toplevel_directory())
 177                         break;
 178                 chdir("..");
 179                 do {
 180                         if (!offset) {
 181                                 if (nongit_ok) {
 182                                         if (chdir(cwd))
 183                                                 die("Cannot come back to cwd");
 184                                         *nongit_ok = 1;
 185                                         return NULL;
 186                                 }
 187                                 die("Not a git repository");
 188                         }
 189                 } while (cwd[--offset] != '/');
 190         }
 191
 192         if (offset == len)
 193                 return NULL;
 194
 195         /* Make "offset" point to past the '/', and add a '/' at the end */
 196         offset++;
 197         cwd[len++] = '/';
 198         cwd[len] = 0;
 199         return cwd + offset;
 200 }
 201
 202 int check_repository_format_version(const char *var, const char *value)
 203 {
 204        if (strcmp(var, "core.repositoryformatversion") == 0)
 205                repository_format_version = git_config_int(var, value);
 206         else if (strcmp(var, "core.sharedrepository") == 0)
 207                 shared_repository = git_config_bool(var, value);
 208        return 0;
 209 }
 210
 211 int check_repository_format(void)
 212 {
 213         git_config(check_repository_format_version);
 214         if (GIT_REPO_VERSION < repository_format_version)
 215                 die ("Expected git repo version <= %d, found %d",
 216                      GIT_REPO_VERSION, repository_format_version);
 217         return 0;
 218 }
 219
 220 const char *setup_git_directory(void)
 221 {
 222         const char *retval = setup_git_directory_gently(NULL);
 223         check_repository_format();
 224         return retval;
 225 }