Compiler Design
Q51.
Match the following according to input (from the left column) to the complier phase (in the right column) that processes it.Q52.
The correct matching for the following pairs is \begin{array}{ll|ll} \text{(A)}&\text{Activation record} & \text{(1)} &\text{Linking loader} \\ \text{(B)} &\text{Location counter} & \text{(2)} &\text{Garbage collection} \\ \text{(C)}& \text{Reference counts} & \text{(3)} &\text{Subroutine call} \\ \text{(D)}& \text{Address relocation} & \text{(4)}& \text{Assembler} \\ \end{array}Q54.
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 isQ55.
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.Q56.
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 ___________Q58.
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?Q59.
A grammar is defined asA \rightarrow B CB \rightarrow x \mid B xC \rightarrow B \mid DD \rightarrow y \mid EyE \rightarrow zThe non terminal alphabet of the grammar isQ60.
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 _____________