Compiler-Design
October 7, 2023GATE 2003
October 7, 2023Compiler-Design
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Question 33
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Consider the syntax directed translation scheme (SDTS) given in the following.
Assume attribute evaluation with bottom-up parsing, i.e., attributes are evaluated immediately after a reduction.
E → E1 * T {E.val = E1.val * T.val}
E → T {E.val = T.val}
T → F – T1{T.val = F.val – T1.val}
T → F {T.val = F.val}
F → 2 {F.val = 2}
F → 4 {F.val = 4}
(a) Using this SDTS, construct a parse tree for the expression
4 – 2 – 4 * 2
and also compute its E.val.
(b) It is required to compute the total number of reductions performed to parse a given input. Using synthesized attributes only, modify the SDTS given, without changing the grammar, to find E.red, the number of reductions performed while reducing an input to E.
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Theory Explanation is given below.
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Correct Answer: A
