# Recent questions tagged compiler-design

1
State whether the following statements are True or False with reasons for your answer: A two pass assembler uses its machine opcode table in the first pass of assembly.
2
State whether the following statements are True or False with reasons for your answer A symbol declared as ‘external’ in an assembly language program is assigned an address outside the program by the assembler itself.
3
Consider the following $\text{ANSI C}$ program: int main () { Integer x; return 0; } Which one of the following phases in a seven-phase $C$ compiler will throw an error? Lexical analyzer Syntax analyzer Semantic analyzer Machine dependent optimizer
1 vote
4
In the context of compilers, which of the following is/are $\text{NOT}$ an intermediate representation of the source program? Three address code Abstract Syntax Tree $\text{(AST)}$ Control Flow Graph $\text{(CFG)}$ Symbol table
5
Consider the following $\text{ANSI C}$ code segment: z=x + 3 + y->f1 + y->f2; for (i = 0; i < 200; i = i + 2) { if (z > i) { p = p + x + 3; q = q + y->f1; } else { p = p + y->f2; q = q + x + 3; } } Assume that the variable $y$ points to ... the form $\textsf{ y ->f1}$ or $\textsf{y ->f2}$) in the optimized code, respectively, are: $403$ and $102$ $203$ and $2$ $303$ and $102$ $303$ and $2$
6
For a statement $S$ in a program, in the context of liveness analysis, the following sets are defined: $\text{USE}(S)$ : the set of variables used in $S$ $\text{IN}(S)$ : the set of variables that are live at the entry of $S$ $\text{OUT}(S)$ : the set of variables that are live at the ... $) }\cup \text{ OUT ($S_2$)}$ $\text{OUT ($S_1$)} = \text{USE ($S_1$)} \cup \text{IN ($S_2$)}$
7
Consider the following augmented grammar with $\{ \#, @, <, >, a, b, c \}$ ... $I_0 = \text{CLOSURE}(\{S' \rightarrow \bullet S\})$. The number of items in the set $\text{GOTO(GOTO}(I_0<), <)$ is ___________
1 vote
8
Consider the following statements. $S_1:$ Every $\text{SLR(1)}$ grammar is unambiguous but there are certain unambiguous grammars that are not $\text{SLR(1)}$. $S_2:$ For any context-free grammar, there is a parser that takes at most $O(n^3)$ time to parse a string of length $n$. ... $S_2$ is false $S_1$ is false and $S_2$ is true $S_1$ is true and $S_2$ is true $S_1$ is false and $S_2$ is false
1 vote
9
Consider the following grammar (that admits a series of declarations, followed by expressions) and the associated syntax directed translation $\text{(SDT)}$ ... The actions can be used to type-check syntactically correct boolean variable declarations and boolean expressions. The actions will lead to an infinite loop
10
Consider the following context-free grammar where the set of terminals is $\{a,b,c,d,f\}$ ... $\boxed{1}\;\text{blank} \qquad \boxed{2}\;\text{S} \rightarrow \text{R}f \qquad \boxed{3}\; \text{blank} \qquad \boxed{4}\;\text{blank}$
1 vote
11
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 $\text{(DAG)}$. The number of nodes in the $\text{DAG}$ is _____________
12
Which of the following is not an intermediate code form? Syntax trees Three address codes Quadrupules Post fix Notation
13
Which of the following are applications of symbol table? Storage allocation Checking type compatibility Suppressing duplicate error messages Choose the correct answer from the options given below: $(a)$ and $(b)$ only $(a)$ and $(c)$ only $(b)$ and $(c)$ only $(a)$ $(b)$ and $(c)$
14
Find the lexicographic ordering of the bit strings given below based on the ordering $0<1$. $001$ $010$ $011$ $0001$ $0101$ Choose the correct answer from the options given below: $001 < 010 < 011 < 0001 < 0101$ $0001 < 001 < 010 < 0101 < 011$ $0001 < 0101 < 001 < 010 < 011$ $001 < 010 < 0001 < 0101 < 011$
15
Which of the following can be accessed by transfer vector approach of linking? External data segments External subroutines Data located in other procedure All of these
16
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The most powerful parser is $\text{SLR}$ $\text{LALR}$ Canonical $\text{LR}$ Operator-precedence
$\text{YACC}$ builds up $\text{SLR}$ parsing table Canonical $\text{LR}$ parsing table $\text{LALR}$ parsing table None of these
Context-free grammar can be recognized by finite state automation $2$- way linear bounded automata push down automata both (B) and (C)
Consider an $\varepsilon$-tree CFG. If for every pair of productions $A\rightarrow u$ and $A\rightarrow v$ If $\text{FIRST(u)} \cap \text{FIRST(v)}$ is empty then the CFG has to be $LL(1).$ If the CFG is $LL(1)$ then $\text{FIRST(u)} \cap \text{FIRST(v)}$ has to be empty. Both $(A)$ and $(B)$ None of the above