Parsing and Syntax directed translation

Question 61

Shift reduce parsing belongs to a class of

• bottom up parsing
• top down parsing
• recursive parsing
• predictive parsing

Question 62

Which of the following productions eliminate left recursion in the productions given below: S → Aa | b A → Ac | Sd | ε

• S → Aa | b A → bdA\' A\' → A\'c | A\'ba | A | ε

• S → Aa | b A → A\' | bdA\', A\' → cA\' | adA\' | ε

• S → Aa | b A → A\'c | A\'d A\' → bdA\' | cA | ε

• S → Aa | b A → cA\' | adA\' | bdA\' A\' → A | ε

Question 63

Which one from the following is false?

• LALR parser is Bottom - Up parser
• A parsing algorithm which performs a left to right scanning and a right most deviation is RL (1)
• LR parser is Bottom - Up parser.
• In LL(1), the 1 indicates that there is a one - symbol look - ahead.

Question 64

Which phase of compiler generates stream of atoms?

• Syntax Analysis
• Lexical Analysis
• Code Generation
• Code Optimization

Question 65

Shift-Reduce parsers perform the following:

• Shift step that advances in the input stream by K(K > 1) symbols and Reduce step that applies a completed grammar rule to some recent parse trees, joining them together as one tree with a new root symbol.
• Shift step that advances in the input stream by one symbol and Reduce step that applies a completed grammar rule to some recent parse trees, joining them together as one tree with a new root symbol.
• Shift step that advances in the input stream by K(K = 2) symbols and Reduce step that applies a completed grammar rule to form a single tree
• Shift step that does not advance in the input stream and Reduce step that applies a completed grammar rule to form a single tree.

Question 66

Which of the following is true?

• Canonical LR parser is LR (1) parser with single look ahead terminal
• All LR(K) parsers with K > 1 can be transformed into LR(1) parsers.
• Both (A) and (B)
• None of the above

Question 67

In a two-pass assembler, symbol table is

• Generated in first pass
• Generated in second pass
• Not generated at all
• Generated and used only in second pass

Question 68

How many tokens will be generated by the scanner for the following statement ? x = x ∗ (a + b) – 5;

• 12
• 11
• 10
• 07

Question 69

Incremental-Compiler is a compiler

• which is written in a language that is different from the source language
• compiles the whole source code to generate object code afresh
• compiles only those portion of source code that have been modified.
• that runs on one machine but produces object code for another machine

Question 70

DU-chains(Definition-Use) in compiler design

• consist of a definition of a variable and all its uses, reachable from that definition
• are created using a form of static code analysis
• are prerequisite for many compiler optimization including constant propagation and common sub-expression elimination
• All of the above