Subject: Compiler Construction

Q.4 (CLO3) (4 marks) Consider the following attribute grammar: Grammar Rule Semantic Rule S+ABC B.u=S.u C.u= A.V A.u=B.v + C.V S.V=A.V A+a A.V= 2 * A.u B B.v=B.u C C C.v=C.u - 2 i. Draw the parse tree for the string abc and draw the dependency graph for the associated attributes. Describe a correct order for the evaluation of the attributes. (2 m) ii. What value does S.v have after attribute evaluation, if S.u=3 before evaluation begins? (2 m) Q.4 (CLO3) (4 marks) Consider the following attribute grammar: Grammar Rule Semantic Rule S+ABC B.u=S.u C.u= A.V A.u=B.v + C.V S.V=A.V A+a A.V= 2 * A.u B B.v=B.u C C C.v=C.u - 2 i. Draw the parse tree for the string abc and draw the dependency graph for the associated attributes. Describe a correct order for the evaluation of the attributes. (2 m) ii. What value does S.v have after attribute evaluation, if S.u=3 before evaluation begins? (2 m)