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(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        return 0;
 184 }
 185
 186 int check_repository_format(void)
 187 {
 188         git_config(check_repository_format_version);
 189         if (GIT_REPO_VERSION < repository_format_version)
 190                 die ("Expected git repo version <= %d, found %d",
 191                      GIT_REPO_VERSION, repository_format_version);
 192         return 0;
 193 }
 194
 195 const char *setup_git_directory(void)
 196 {
 197         const char *retval = setup_git_directory_gently(NULL);
 198         check_repository_format();
 199         return retval;
 200 }