2nd Sess Comp

Radha Govind Engineering College, Meerut II Sessional Test (2006-2007) B.Tech V Semester (CS) Compiler Design (TCS 502) Time: 1:00 hr. Note: Attempt any three questions.

MM: 30

Q.1 Consider the following grammar G E-> EBE/(E)/num B-> + / - / * / \ (i) (ii)

Explain why this grammar is not suitable for a recursive descent parser. Obtain a grammar G’ from G, which can be use for recursive descent parser. Find the FIRST(G’) and FOLLOW(G’).

(iii)

Q.2 Discuss algorithm for computation of the sets of LR(0) or SLR items. Also compute LR(0) items and draw transition diagram for the grammar G E-> E+T/ T T-> TF / F F-> F* / a / b Q.3 Discuss the operator precedence parsing algorithm. Parse the input string id+id*id for the grammar T->T+T / T*T/ (T) / id Where precedence function is-

f g

+ 4 3

* 2 1

id 4 5

$ 0 0

Q.4 Consider the following grammar G S-> ACB / CbB / Ba A-> da / BC B-> g / ε C-> h / ε (i) (ii) (iii)

Find FIRST(G) and FOLLOW(G). Check G is LL(1) or not. Construct parsing table for predictive parser.

Q.5 What is shift reduce parser. Parse the string id+id*id with the help of stack implementation of shift reduce parser for the grammar given in Q. 3

RADHA GOVIND ENGINEERING COLLEGE, MEERUT 2ND Sessional Test (2005-06) Subject: Compiler Construction (CS-604) Class: B.Tech (CS) VI Sem Time: 1:15 hr. Note: Attempt any four questions.

Q.1

MM: 30

(a) What is parsing? Explain the role of the parser in the compiler. (b) Write the short note on LEX.

Q.2 Prepare the SLR parsing table for the grammarE-> E+T/ T T-> TF / F F-> F* / a / b Q.3 Write the algorithms for calculating FIRST and FOLLOW of grammar and find the first and follow for S-> iTCeb /CTe/ TeCb C-> aCb/ ε T-> bCT/CT/ ε Q.4 Write the algorithm for Recursive Descent parser for the following grammarE -> TE' E'-> +TE'/ ε T -> FT' T'-> *FT'/ ε F -> (E) / id Q.5 What is LL(1) grammar? Write the procedure to check LL(1) and for constructing LL(1) parsing table

Radha Govind Engineering College, Meerut Second Sessional Test(2004-05) B.Tech(CS) VI Sem Subject: Compiler Construction Code: CS-604 Time: 1:15 hr. MM: 30 Note: Attempt All questions.

Q.1 Discuss the operator precedence-parsing algorithm. Parse the input string id+id*id for the grammar E->E+E / E*E/ (E) / id Where precedence function isf g

+ 4 3

* 2 1

id 4 5

$ 0 0

OR What is left factoring? Why it is done? How we remove the left factor from a grammar show with the help of an example and also explain left-recursion. Q2: Translate the arithmetic expression a*-( b+c) into a) A syntax tree b) Postfix notation c) Three-address code OR Translate the expression -( a+b) * (c+d) +( a+b+c) into a) Quadruples b) Triples c) Indirect triples Q.3 Consider the following grammar G S-> ACB / CbB / Ba A-> da / BC B-> g / ε C-> h / ε (iv) (v) (vi)

Find FIRST(G) and FOLLOW(G). Check G is LL(1) or not. Construct parsing table for predictive parser.

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