# Parsing

 Question 1
Consider the following grammar along with translation rules.
\begin{aligned} &S \rightarrow S_1 \# T & & \{S._{val}=S_{1.val}*T._{val} \} \\ &S \rightarrow T & & \{S._{val}=T._{val} \} \\ &T \rightarrow T_1 \% R & & \{T._{val}=T_{1.val} \div R._{val} \} \\ &T \rightarrow R & & \{T._{val}=R._{val} \} \\ &R \rightarrow id & & \{R._{val}=id._{val} \} \\ \end{aligned}
Here $\#$ and $\%$ are operators and $id$ is a token that represents an integer and $id_{.val}$ represents the corresponding integer value. The set of non-terminals is $\{S,T,R,P \}$ and a subscripted non-terminal indicates an instance of the non-terminal.
Using this translation scheme, the computed value of $S_{.val}$ for root of the parse tree for the expression $20 \# 10 \% 5 \# 8 \% 2 \% 2$ is
 A 20 B 65 C 160 D 80
GATE CSE 2022   Compiler Design
Question 1 Explanation:
 Question 2
Consider the augmented grammar with $\{+, *, (, ), id \}$ as the set of terminals.
\begin{aligned}&S' \rightarrow S \\ &S \rightarrow S+R|R \\ &R \rightarrow R*P|P \\ &P \rightarrow (S)|id \end{aligned}
If $I_0$ is the set of two $LR(0)$ items $\{ [S' \rightarrow S.], [S \rightarrow S.+R] \}$, then $goto(closure(I_0 ),+)$ contains exactly ______ items.
 A 2 B 3 C 4 D 5
GATE CSE 2022   Compiler Design
Question 2 Explanation:

 Question 3
Which one of the following statements is TRUE?
 A The LALR(1) parser for a grammar G cannot have reduce-reduce conflict if the LR(1) parser for G does not have reduce-reduce conflict. B Symbol table is accessed only during the lexical analysis phase. C Data flow analysis is necessary for run-time memory management. D LR(1) parsing is sufficient for deterministic context-free languages.
GATE CSE 2022   Compiler Design
Question 3 Explanation:
 Question 4
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 4 Explanation:
 Question 5
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 5 Explanation:

There are 5 questions to complete.

### 9 thoughts on “Parsing”

1. in question no. 7 there will be b instead of d in production B
S→aSB∣d
B→b

• Thank You Ankush Banik,
We have updated the question.

2. Nice webiste , Good

3. B option of Q20 is incomplete

4. Q41) this question should be the part of SDT. right?

• This question covers multiple topics of Compiler Design subject including parsing and SDT.

5. Hello Sir/ Ma’am
In question 33, the lookahead of the second production rule is not defined, leads to create a confusion in ones mind.
The second production should like
X –> c.X, $X –> .cX,$
X–> .d , $Thanks for such awesome website for practicing PYQ😇 Reply 6. pls correct the question 33. it’s not same as gateoverflow question, bcz$ is missing at the end of the production of G2 Grammer

7. 