Index: src/Validate/Autogen.cpp
===================================================================
--- src/Validate/Autogen.cpp	(revision 9939dc312f9fd40e9451c8c3c70ac5e68e233d16)
+++ src/Validate/Autogen.cpp	(revision 07997cd791b7a0e04d564b2c80dba2c524a0d108)
@@ -402,4 +402,8 @@
 	auto retval = srcParam();
 	retval->name = "_ret";
+	// xxx - Adding this unused attribute can slience unused variable warning
+	// However, some code might not be compiled as expected
+	// Temporarily disabled
+	// retval->attributes.push_back(new ast::Attribute("unused"));
 	return genProto( "?=?", { dstParam(), srcParam() }, { retval } );
 }