--- glibc-2.19/misc/sys/cdefs.h.omv~	2014-06-22 14:53:05.862531155 +0200
+++ glibc-2.19/misc/sys/cdefs.h	2014-06-22 14:53:21.560531205 +0200
@@ -328,7 +328,7 @@
 
 /* GCC 4.3 and above allow passing all anonymous arguments of an
    __extern_always_inline function to some other vararg function.  */
-#if __GNUC_PREREQ (4,3)
+#if __GNUC_PREREQ (4,3) && !defined(__clang__)
 # define __va_arg_pack() __builtin_va_arg_pack ()
 # define __va_arg_pack_len() __builtin_va_arg_pack_len ()
 #endif