Index: src/Parser/ParseNode.h
===================================================================
--- src/Parser/ParseNode.h	(revision 6016c874a17e2a5bf68cc3be0670a2fa39751491)
+++ src/Parser/ParseNode.h	(revision c81ebf924fb91ca84affb100df945a8a6441e956)
@@ -61,6 +61,6 @@
 	}
 
-	virtual void print( std::ostream &os, int indent = 0 ) const {}
-	virtual void printList( std::ostream &os, int indent = 0 ) const {}
+	virtual void print( __attribute__((unused)) std::ostream &os, __attribute__((unused)) int indent = 0 ) const {}
+	virtual void printList( __attribute__((unused)) std::ostream &os, __attribute__((unused)) int indent = 0 ) const {}
 
 	static int indent_by;
@@ -113,6 +113,6 @@
 	ExpressionNode * set_extension( bool exten ) { extension = exten; return this; }
 
-	virtual void print( std::ostream &os, int indent = 0 ) const override {}
-	void printOneLine( std::ostream &os, int indent = 0 ) const {}
+	virtual void print( __attribute__((unused)) std::ostream &os, __attribute__((unused)) int indent = 0 ) const override {}
+	void printOneLine( __attribute__((unused)) std::ostream &os, __attribute__((unused)) int indent = 0 ) const {}
 
 	template<typename T>
@@ -283,6 +283,6 @@
 	}
 
-	virtual void print( std::ostream &os, int indent = 0 ) const override;
-	virtual void printList( std::ostream &os, int indent = 0 ) const override;
+	virtual void print( __attribute__((unused)) std::ostream &os, __attribute__((unused)) int indent = 0 ) const override;
+	virtual void printList( __attribute__((unused)) std::ostream &os, __attribute__((unused)) int indent = 0 ) const override;
 
 	Declaration * build() const;
@@ -363,6 +363,6 @@
 	virtual StatementNode * append_last_case( StatementNode * );
 
-	virtual void print( std::ostream &os, int indent = 0 ) const override {}
-	virtual void printList( std::ostream &os, int indent = 0 ) const override {}
+	virtual void print( __attribute__((unused)) std::ostream &os, __attribute__((unused)) int indent = 0 ) const override {}
+	virtual void printList( __attribute__((unused)) std::ostream &os, __attribute__((unused)) int indent = 0 ) const override {}
   private:
 	std::unique_ptr<Statement> stmt;