Hi! When compiling slock with clang, one sees: /scratch/x11/slock/work/.buildlink/include/X11/Xfuncproto.h:157:24: warning: named variadic macros are a GNU extension [-Wvariadic-macros] #define _X_NONNULL(args...) __attribute__((nonnull(args))) Is there a way to define this without using GNU extensions? Thomas