University of Delhi 2010 M.C.A 2nd yr4th COMPILER DESIGN UNIVERSITY - Question Paper
This question paper contains 4 printed pages.
6134 Your Roll /Va...............
MCA/IV Sem.
J
MCA 401 - COMPILER DESIGN (Admissions of 2007 and onwards)
Time 3 hours Maximum Marks 60
(Wnte your Roll No on the top immediately on receipt of this question paper )
Attempt all questions.
Parts of a question must be answered together.
1. a) Wnte aregular expression that generates the same language as the following grammer
A-> aA\B\ 6
B > b B \ A 02
b) Write a context free grammar that generates the same language as the following regular expression
(a \ c \ ba \ be)* b 02
c) What is meant by peehole optimization9 02
2 Consider the grammar
lexp-seq > lexp-seq lexp \ lexp lexp > atom \ list atom number\ identifier list - (lex-seq)
a) Remove left recursion
b) Construct FIRST and FOLLOW sets for the non -terminals of the resulting grammar.
c) Construct the LL(1) passing table for the resulting grammar
d) Show the actions of the corresponding LL(1) parser, given the input string
(b (2)) 12
3 Consider the grammar
S*->S
S - (S) S/E
a) Construct the DFA to be used in SLR parsing
b) What are the valid states for the viable prefix ((' 9 Justify.
c) Construct the initial state for the LR (1) parsing.
d) Determine the valid states fbHheittle prefix *((1 12
4 a) Consider the attnbute grammar *
Grammar Rule Semantic Rule
decl > type var-list var-list dtype = type.dtype type -int type.dtype = integer
type float type dtype = real
varhstj id, var-list2 id.dtype ~ var-list! dtype
var-list2 dtype = var-listj dtype var-list > id id dtype=var-list.dtype
b) Show that the grammar given below is not LR(1) Can it be LR (K) for some suitable k. Justify.
B ABb / a
A 04
5 Consider the following grammar for type expression
var-decls > var-decls; vardecl / var-decl var-decls > id, type-exp type-exp -> simple-type / structured - type simple-type > int / bool / real / char / void structured - type array [ num) of type - exp / record var - decls end / union var - decls end Write pseudocode for checking type equivalence. 06
6 Write pseudocode for code generation for control statements described by the grammar:
stmt if - stmt / while - stmt / break / other
if - stmt if-(exp) stmt / if (exp) stmt else stmt
while - stmt > while (exp) stmt
exp true \ false 06
7 a) Consider the following grammar rule
S > while (C )St Outline the implementation of synthesize attributes as well as inherited attributes for the above grammar in LR parsing. You may make necessary modification to grammar without changing the language. 04
b) How does yacc resolve reduce / reduce and shift / reduce conflicts. 02
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c) Consider the following grammar along with semantic rules | ||||||||||||||
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Give a annotated parse tree for the following expression int a, b,c. 04 |
too
Show that if the attribute type dtype is kept on the value stack during an LR parser, than this value cannot be found at a fixed position in the stack when reductions by the rule var-list > id occur 04
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| Earning: Approval pending. |
