Compiler Design – Multiple Choice Questions (MCQs)

1. 25. What is an LL(1) parser?

   • A. A top-down parser that reads input from Left to right
   • B. performs Leftmost derivation
   • C. and uses 1 lookahead symbol
   • D. A bottom-up parser

2. 26. What is an LR(0) parser?

   • A. A bottom-up parser that reads input from Left to right
   • B. performs Rightmost derivation in reverse
   • C. and uses 0 lookahead symbols
   • D. A top-down parser

3. 27. What is an SLR(1) parser?

   • A. A bottom-up parser that uses 1 lookahead symbol to resolve conflicts in LR(0) parsing tables
   • B. A top-down parser with 1 lookahead
   • C. An LR parser with no lookahead
   • D. A parser that uses leftmost derivation

4. 28. What is an LALR(1) parser?

   • A. A bottom-up parser that merges states with the same lookahead sets in an LR(1) parser
   • B. A top-down parser with limited lookahead
   • C. An LR parser with no lookahead merging
   • D. A parser that simplifies grammar rules

5. 29. What is an LR(1) parser?

   • A. A powerful bottom-up parser that uses 1 lookahead symbol and does not merge states with the same core
   • B. A simple top-down parser
   • C. An LR parser with 0 lookahead
   • D. A parser designed for ambiguous grammars

6. 30. What is an abstract syntax tree (AST)?

   • A. A tree representation of the syntactic structure of source code that omits some details of the concrete syntax
   • B. The parse tree itself
   • C. The sequence of tokens
   • D. The symbol table

7. 31. What is intermediate representation (IR)?

   • A. A language-independent representation of the source program used for analysis and optimization
   • B. The target machine code
   • C. The original source code
   • D. The token stream

8. 32. Which of the following is a property of a good intermediate representation?

   • A. Ease of generation from source code
   • B. Suitability for optimization
   • C. Ease of translation to target code
   • D. All of the above

9. 33. What is static single assignment (SSA)?

   • A. An intermediate representation where each variable is assigned a value only once
   • B. A representation where variables can be assigned multiple times
   • C. A representation used only for functional programming languages
   • D. A low-level machine code representation

10. 34. What is control flow analysis?

    • A. Analyzing the order in which statements in a program are executed
    • B. Analyzing the data flow in a program
    • C. Analyzing the syntax of the program
    • D. Analyzing the lexical structure

11. 35. What is data flow analysis?

    • A. Analyzing how values are transmitted and used throughout a program
    • B. Analyzing the control flow
    • C. Analyzing the syntax
    • D. Analyzing the lexical structure

12. 36. What is register allocation?

    • A. The process of assigning variables to registers in the target machine
    • B. The process of allocating memory on the stack
    • C. The process of allocating space for global variables
    • D. The process of assigning data types to variables