CS606-Compiler Construction Quiz #Objective #Questions
1. Which of the following statement is true about Two-pass compiler.
- Front End depends upon Back End
- Back End depends upon Front End ✔
- Both are independent of each other
- None
2. In a three-pass compiler, ___ is used for code improvement or optimization.
- Front End
- Middle End ✔
- Back End
- Both Front End and Back End
3. In multi-pass compiler during the first pass, it gathers information about ___
- Declaration ✔
- Bindings
- Static information
- None
4. Which of the statement is true about Regular Languages?
- Regular Languages are the most popular for specifying tokens.
- Regular Languages are based on simple and useful theory.
- Regular Languages are easy to understand
- All of the given ✔
5. The DFA uses its state to keep track of ___ the NFA can be in after reading each input symbol.
- Accept state
- Reject state
- Next state
- All possible states ✔
6. In ___ certain check are performed to ensure that components of a program fit together meaningfully.
- Linear analysis
- Hierarchical analysis
- Semantic analysis ✔
- None
7. Compilers are some times classifies as:
- Single-pass
- Multipass
- Load and go
- All of the given ✔
8. In compiler, linear analysis is also called
- Lexical analysis
- Scanning
- Both lexical analysis and scanning ✔
- None
9. In a transition table cells of the table contain the ___ state.
- Reject state
- Next state ✔
- Previous state
- None
10. In Back End module of the compiler, optimal register allocation uses ___.
- O(log n)
- O(n log n)
- NP-Complete ✔
- None
11. A non-recursive predictive parser is also called ___
- table-driven parser ✔
- Abstract parser
- Conceptual parser
- None
12. The shift action ___ a terminal on the stack
- Pushes ✔
- Pops
- Both pushes and pops
- None
13. Bottom-up parsing is also called ___
- LR parsing ✔
- LT parsing
- LS parsing
- SS parsing
14. ___ of a two-pass compiler is consists of instruction selection, Register allocation and instrcution scheduling
- Backend ✔
- Frontend
- Start
- None
15. Consider the grammar
A -> B C C
B -> h B | epsilon
C -> C g | g | C h | i
D -> A B | epsilon
First of A is ___
- h, g, i
- g
- h ✔
- None
16. A -> B C C
B -> h B | epsilon
C -> C g | g | C h | i
D -> A B | epsilon
Follow of A ___
- h, $
- $
- i
- g
17. A -> B C C
B -> h B | epsilon
C -> C g | g | C h | i
D -> A B | epsilon
B -> h B | epsilon
C -> C g | g | C h | i
D -> A B | epsilon
Follow of C is ___
- g, h, i, $ ✔
- g, h, $
- h, i, $
- h, g, $
18. Left factoring of grammar is done to save the parser from backtracking.
- True ✔
- False
19. Typical compilation means programs written in high-level languages to low-level ___
- Object code
- Byte code
- Unicode
- Object code and byte code ✔
20. In compilation process, Hierarchical analysis is also called ___
- Parsing
- Syntax
- Parsing and Syntax analysis ✔
- None
21. IR (Intermediate Representation) stores the value of its operand in ___
- Registers ✔
- Memory
- Hard disk
- None
22. A lexeme is a sequence of characters in the source program that is matched by the pattern for a ___
- Linker
- Token ✔
- Control flow
- None
23. Parsers take ___ as Input from lexical analyzer.
- Linker
- Token ✔
- Instructions
- None
24. What kind of abstract machine can recognize strings in a regular set?
- DFA ✔
- NFA
- PDA
- None
25. In DFA minimization, we construct one ___ for each group of states from the initial DFA.
- State ✔
- NFA
- PDA
- None
26. ___ (lexical Analyzer generator), is written in Java
- Flex
- Jlex ✔
- Complex
- None
27. In flex specification file, different sections are separated by ___
- %% ✔
- &&
- ##
- None
28. Recursive ___ parsing is done for LL(I) grammar.
- Descent y✔
- Ascent
- Forward
- None
29. Alternative of the backtrack in parser is Look ahead symbol in ___
- Input ✔
- Output
- Input and Output
- None
30. Parser takes tokens from scanner and tries to generate ___
- Binary Search Tree
- Parse tree ✔
- Binary Search and Parse tree
- None
31. In predictive parsing table, the rows represents ___
- Terminals
- Both non-terminals and terminals
- Non-terminals ✔
- None
32. In LL(I) parsing algorithm, ___ contains a sequence of grammar symbols.
- Stack ✔
- Link list
- Array
- None
33. Consider the grammar
A -> B C D
B -> h B | epsilon
C -> C g | g | C h | i
D -> A B | epsilon
First of C is ___
- g, i ✔
- g
- h, i
- None
34. Bottom-up parsing uses only ___ kinds of actions.
- Two ✔
- Three
- Four
- Five
35. Reduce ___ action zero or more symbols from the stack.
- Pushes
- Pops ✔
- Both push and pops
- None
36. Back End of two-pass compiler uses ___ algorithm
- O(n)
- O(n log n)
- NP complete ✔
- None
37. The Back End of a compiler consists of ___
- Instruction selection ✔
- Register allocation
- Instruction scheduling
- All of given
38. ___ is a regular expression for the set of all strings over the alphabet {a} that has an even number of a’s
- aa*
- (aa)* ✔
- aa*a
- a(aa)*
39. ___ algorithm is used in DFA minimization.
- Jame’s
- Robert’s
- Hopcroft’s y✔
- None
40. ___ is an important component of semantic analysis.
- Code checking
- Type checking ✔
- Flush checking
- None
41. Consider the grammar
A – > B C D
B -> h B | epsilon
C -> C g | g | C h | i
First of B is ___
- h, i
- h, epsilon ✔
- g
- None
42. Consider the grammar
A -> B C D
B -> h B | epsilon
C -> C g | g | C h | i
D -> A B | epsilon
First of D is ___
- h, g
- h
- h, g, i, epsilon ✔
- None
43. ___ parsers never shifts into an error state.
- LS
- LT
- LR ✔
- LP
44. ___ read the input character and produce sequence of tokens as output.
- Lexical analyzer ✔
- Parser
- Symbol table
- None
45. The regular expression ___ denotes, the set of all strings of a’s and b’s of length two.
- a*
- (a*| b*)*
- (a*b*)*
- (a|b)(a|b) ✔
46. ___ is evaluated to yield a value.
- Command
- Expression ✔
- Declaration
- None
47. Bottom-up parsers handle a ___ class of grammar
- Large ✔
- Small
- Medium
- None
48. LR parsers can handle ___ grammars.
- Left-recursive ✔
- File-recursive
- End-recursive
- Start-recursive
49. ___ convert the relocatable machine code into absolute machine code by linking library and relocatable object files.
- Assembler
- Loader/link-editor ✔
- Compiler
- Preprocessor
50. Consider the grammar
A -> B C D
B -> h B | epsilon
C -> C g | g | C h | i
D -> A B | epsilon
Follow of B is ___
- h ✔
- g, h, i, $
- g, i
- g
51. In PASCAL ___represent the inequality test.
- :=
- =
- <> ✔
- None
52. ___ avoid hardware stalls and interlocks.
- Register allocation
- Instruction scheduling ✔
- Instruction selection
- None
53. One of the core tasks of compiler is to generate fast and compact executable code.
- True ✔
- False
54. Responsibility of ___ is to produce fast and compact code.
- Instruction selection ✔
- Register allocation
- Instruction scheduling
- None
55. Compilers are sometimes classified as
- Single pass
- Multi pass
- Load and go
- All of given ✔
56. Flex is an automated tool that is used to get the minimized DFA (scanner).
- True
- False ✔
57. For each language to make LL(1) grammar, we take two steps, 1st is removing left recurrence and 2nd is applying left factoring in sequence.
- True ✔
- False
58. Optimal registers allocation is an NP-hard problem.
- True
- False ✔
59. Front end of two pass compiler takes ___ as input.
- Source code ✔
- Intermediate Representation (IR)
- Machine code
- None
60. NFA is easy to implement as compared to DFA
- True
- False ✔
61. We can get an LL(1) grammar by ___
- Removing left recurrence
- Applying left factoring
- Removing left recurrence and Applying left factoring ✔
- None
62. Parser always gives a tree like structure as output
- True
- False
63. Lexer and scanner are two different phases of compiler.
- True
- False ✔
64. ___ phase which supports macro substitution and conditional compilation.
- Semantic
- Syntax
- Preprocessing ✔
- None
65. ___ tree in which each node represents an operator and children of the node represent the operands
- Abstract syntax ✔
- Concrete syntax
- Parse
- None
66. Ambiguity can easily be handled by top-down parser
- True ✔
- False
67. LR parsing ___ a string to the start symbol by inverting productions.
- Reduces ✔
- Shifts
- Adds
- None
68. In parser the two LL stand(s) for ___
- Left-to-right scan of input
- left-most derivation
- All of the given ✔
- None
69. Can a DFA simulate NFA?
- Yes ✔
- No
- Sometimes
- Depend upon NFA
70. The transition graph for an NFA that recognized the language (a|b)*abb will have following set of states.
- {0}
- {0, 1}
- {0, 1, 2}
- {0, 1, 2, 3} ✔
71. Functions of Lexical analyzer are?
- Removing white space
- Removing constants, identifiers and keywords
- Removing comments
- All of given ✔
72. ___ method is known as subset construction method.
- NFA to DFA ✔
- DFA
- DFA maximization
- None
73. Which one is NOT the Role of Run-Time System?
- garbage collection
- memory management
- run time error checking
- None ✔
74. Compiler ___ information from one representation to another.
- modified
- translate ✔
- execute
- extract
75. Front-end of a two pass compiler is consists of scanner.
- True
- False ✔
76. Backtracking is a costly operation which is caused due to Left Recursion.
- True
- False ✔
77. AST summarizes the grammatical structure with the details of derivations.
- True
- False ✔
78. Backtrack is term associated with Top-down parsing.
- True ✔
- False
79. Which of the following statement/s is/are true about Deterministic Finite Automata?
80. The lexical analyzer partition input string into substrings called ___
