+#ifndef FILESYSTEM_PREFIX_LEN
+# define FILESYSTEM_PREFIX_LEN(Filename) 0
+#endif
+
+#ifndef ISSLASH
+# define ISSLASH(C) ((C) == '/')
+#endif
+
+/* In general, we can't use the builtin `basename' function if available,
+ since it has different meanings in different environments.
+ In some environments the builtin `basename' modifies its argument.
+ If NAME is all slashes, be sure to return `/'. */