CSE334_CA10_Lexical analysis

The number of tokens in the following C statement is printf("HELLO WORLD");

• 8

• 9

• 5

• 3

In a compiler, keywords of a language are recognized during

• the lexical analysis of the program

• code generation

• parsing of the program

• dataflow analysis

The lexical analysis for a modern computer language such as Java needs the power of which one of the following machine models in a necessary and sufficient sense?

• Finite state automata

• Deterministic pushdown automata

• Non-Deterministic pushdown automata

• Turing Machine

Consider the following statements: (I) The output of a lexical analyzer is groups of characters. (II) Total number of tokens in printf("i=%d, &i=%x", i, &i); are 11. (III) Symbol table can be implementation by using array and hash table but not tree. Which of the following statement(s) is/are correct?

• Only (I)

• Only (II) and (III)

• All (I), (II), and (III)

• None of these

Which one of the following statements is FALSE?

• High-level language programs can be translated to different Intermediate Representations.

• Context-free grammar can be used to specify both lexical and syntax rules.

• Type checking is done before parsing.

• Arguments to a function can be passed using the program stack.

A lexical analyzer uses the following patterns to recognize three tokens T1, T2, and T3 over the alphabet {a,b,c}. T1: a?(b∣c)*a T2: b?(a∣c)*b T3: c?(b∣a)*c If the string bbaacabc is processed by the analyzer, which one of the following is the sequence of tokens it outputs?

• T1T2T3

• T3T3

• T1T1T3

• T2T1T3

The output of a lexical analyzer is

• Machine code

• A parse tree

• A stream of tokens

• Intermediate code

Consider the following statements related to compiler construction: I. Lexical Analysis is specified by context-free grammars and implemented by pushdown automata. II. Syntax Analysis is specified by regular expressions and implemented by finite-state machine. Which of the above statement(s) is/are correct?

• Neither I nor II

• Only I

• Both I and II

• Only II

Which of the following statement(s) regarding a linker software is/are true?

1. I. A function of a linker is to combine several object modules into a single load module.

2. II. A function of a linker is to replace absolute references in an object module by symbolic references to locations in other modules.

• Only II

• 1. Both I and II

• Only I

• 1. Neither I nor II

Which of the following grammars is context free?

• S -> ABC

  A -> BC

  AB -> C

  C -> d

• A -> B

  B -> d

• A -> ABC

  B -> BC

  AB -> C

  C -> d

• A -> Null