+#if defined(__MSDOS__) || defined(_WIN32) || defined(__OS2__) || defined (__CYGWIN__)
+# ifndef HAVE_DOS_BASED_FILE_SYSTEM
+# define HAVE_DOS_BASED_FILE_SYSTEM 1
+# endif
+# ifndef HAVE_CASE_INSENSITIVE_FILE_SYSTEM
+# define HAVE_CASE_INSENSITIVE_FILE_SYSTEM 1
+# endif
+# define HAS_DRIVE_SPEC(f) HAS_DOS_DRIVE_SPEC (f)
+# define IS_DIR_SEPARATOR(c) IS_DOS_DIR_SEPARATOR (c)
+# define IS_ABSOLUTE_PATH(f) IS_DOS_ABSOLUTE_PATH (f)
+#else /* not DOSish */
+# if defined(__APPLE__)
+# ifndef HAVE_CASE_INSENSITIVE_FILE_SYSTEM
+# define HAVE_CASE_INSENSITIVE_FILE_SYSTEM 1
+# endif
+# endif /* __APPLE__ */
+# define HAS_DRIVE_SPEC(f) (0)
+# define IS_DIR_SEPARATOR(c) IS_UNIX_DIR_SEPARATOR (c)
+# define IS_ABSOLUTE_PATH(f) IS_UNIX_ABSOLUTE_PATH (f)