Parsing

Question 1
Consider the following augmented grammar with \{ \#, @, <, >, a, b, c \} as the set of terminals.

\begin{array}{l} S' \rightarrow S \\ S \rightarrow S \# cS \\ S \rightarrow SS \\ S \rightarrow S @ \\ S \rightarrow < S > \\ S \rightarrow a \\ S \rightarrow b \\ S \rightarrow c \end{array}

Let I_0 = \text{CLOSURE}(\{S' \rightarrow \bullet S\}). The number of items in the set \text{GOTO(GOTO}(I_0 \lt ), \lt ) is ___________
A
6
B
7
C
8
D
9
GATE CSE 2021 SET-2   Compiler Design
Question 2
Consider the following C code segment:

a = b + c;
e = a + 1;
d = b + c;
f = d + 1;
g = e + f;

In a compiler, this code segment is represented internally as a directed acyclic graph (DAG). The number of nodes in the DAG is _____________
A
11
B
6
C
5
D
10
GATE CSE 2021 SET-1   Compiler Design
Question 3
Consider the following statements.

S1: Every SLR(1) grammar is unambiguous but there are certain unambiguous grammars that are not SLR(1).
S2: For any context-free grammar, there is a parser that takes at most O(n^3) time to parse a string of length n.

Which one of the following options is correct?
A
S1 is true and S2 is false
B
S1 is false and S2 is true
C
S1 is true and S2 is true
D
S1 is false and S2 is false
GATE CSE 2021 SET-1   Compiler Design
Question 4
A grammar is defined as
A \rightarrow B C
B \rightarrow x \mid B x
C \rightarrow B \mid D
D \rightarrow y \mid Ey
E \rightarrow z
The non terminal alphabet of the grammar is
A
\{A, B, C, D, E\}
B
\{B, C, D, E\}
C
\{A, B, C, D, E,x,y,z\}
D
\{x,y,z\}
ISRO CSE 2020   Compiler Design
Question 5
A given grammar is called ambiguous if
A
two or more productions have the same non-terminal on the left hand side
B
a derivation tree has more than one associated sentence
C
there is a sentence with more than one derivation tree corresponding to it
D
brackets are not present in the grammar
ISRO CSE 2020   Compiler Design
Question 6
Given the grammar
s \rightarrow T^{*} S \mid T
T \rightarrow U+T \mid U
U \rightarrow a \mid b
Which of the following statements is wrong?
A
Grammar is not ambiguous
B
Priority of + over * is ensured
C
Right to left evaluation of * and + happens
D
None of these
ISRO CSE 2020   Compiler Design
Question 7
Consider the following grammar.

S\rightarrow aSB|d
B\rightarrow b

The number of reduction steps taken by a bottom-up parser while accepting the string aaadbbb is___________.
A
5
B
6
C
7
D
8
GATE CSE 2020   Compiler Design
Question 8
Consider the augmented grammar given below:
S'\rightarrow S
S \rightarrow \lt L \gt |id
L \rightarrow L,S|S

Let I_0=CLOSURE(\{[S'\rightarrow \cdot S]\}) . The number of items in the set GOTO(I_0,\lt) is __________.
A
2
B
4
C
5
D
6
GATE CSE 2019   Compiler Design
Question 9
Consider the following given grammar:
 
S \rightarrow Aa
A \rightarrow BD
B \rightarrow b|\epsilon
D \rightarrow d|\epsilon 
Let a, b, d and $ be indexed as follows:

Compute the FOLLOW set of the non-terminal B and write the index values for the symbols in the FOLLOW set in the descending order. (For example, if the FOLLOW set is {a, b, d, $}, then the answer should be 3210).
Answer:_____
A
310
B
3100
C
31
D
220
GATE CSE 2019   Compiler Design
Question 10
Which one of the following kinds of derivation is used by LR parsers?
A
Leftmost
B
Leftmost in reverse
C
Rightmost
D
Rightmost in reverse
GATE CSE 2019   Compiler Design
There are 10 questions to complete.

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