--- a/jdk/makefiles/GensrcBuffer.gmk	Wed Jul 05 18:14:56 2017 +0200
+++ b/jdk/makefiles/GensrcBuffer.gmk	Tue Jul 03 16:10:44 2012 -0700
@@ -198,6 +198,7 @@
 	$(if $(12),$1_$(strip $(12)))
 	$(if $(13),$1_$(strip $(13)))
 	$(if $(14),$1_$(strip $(14)))
+	$(if $(15),$(error Internal makefile error: Too many arguments to SetupGenBuffer, please update GensrcBuffer.gmk))
 
 	$(call fixRw,$1,$$($1_RW))
 	$(call typesAndBits,$1,$$($1_type),$$($1_BO))