Question 1

Define Compiler.

Accepted Answer

A compiler translates high-level source code into low-level machine code.

Question 2

What is a Token?

Accepted Answer

A token is the smallest logical sequence of characters meaningful to a compiler.

Question 3

Define Lexical Analysis.

Accepted Answer

Lexical analysis is the very first phase of a compiler that converts characters into tokens.

Question 4

What is Context-Free Grammar?

Accepted Answer

A Context-Free Grammar (CFG) mathematically defines the rigid syntax of a programming language.

Question 5

Define Parse Tree.

Accepted Answer

A parse tree visually graphs the syntactic derivation of a string using CFG rules.

Question 6

What is Left Recursion?

Accepted Answer

Left recursion occurs when a grammar rule allows a non-terminal to derive itself as its leftmost symbol.

Question 7

Define Syntax-Directed Translation.

Accepted Answer

SDT attaches semantic rules to grammar productions to evaluate and translate syntax.

Question 8

What is Three-Address Code?

Accepted Answer

TAC is an intermediate code format where each instruction has at most three operands.

Question 9

Define Symbol Table.

Accepted Answer

A Symbol Table is a highly optimized data structure tracking all source code identifiers.

Question 10

What is Code Optimization?

Accepted Answer

Code optimization mathematically transforms intermediate code to consume less memory and execute faster.

Question 11

Explain the phases of a compiler.

Accepted Answer

A comprehensive architectural breakdown of the six sequential phases of a compiler: Lexical, Syntax, Semantic, Intermediate Code, Optimization, and Target Code generation.

Question 12

Describe the role of Lexical Analyzer in a compiler.

Accepted Answer

The Lexical Analyzer mathematically scans source code to generate tokens, eliminate whitespace, track lines, and interact directly with the Symbol Table.

Question 13

Explain the concept of FIRST and FOLLOW sets with an example.

Accepted Answer

FIRST and FOLLOW sets are mathematically calculated terminal collections that dictate exactly how predictive Top-Down Parsers (like LL(1)) choose production rules without backtracking.

Question 14

Discuss the LL(1) parsing technique.

Accepted Answer

The LL(1) parsing technique is a deterministic, top-down parser that scans Left-to-right, constructs a Leftmost derivation, and uses 1 token of lookahead.

Question 15

Explain the concept of Shift-Reduce parsing.

Accepted Answer

Shift-Reduce parsing is a bottom-up methodology that aggressively shifts tokens onto a stack and reduces them into non-terminals until the start symbol is formed.

Question 16

Describe the various storage allocation strategies.

Accepted Answer

Compilers deploy three rigid storage allocation strategies: Static Allocation (compile-time memory), Stack Allocation (dynamic runtime memory for functions), and Heap Allocation (unstructured dynamic memory).

Question 17

Explain the basic blocks and flow graphs in code optimization.

Accepted Answer

In code optimization, a Basic Block is a strictly linear sequence of code with no branches, while a Flow Graph mathematically links these blocks to map execution paths.

Question 18

(a) Explain the architecture of a compiler in detail. (b) Differentiate betwe…

Accepted Answer

An exhaustive architectural analysis detailing the six specific internal phases of a compiler, followed by a rigorous technical differentiation between Compilers, Interpreters, and Assemblers based on execution speed, memory footprint, and translation methodology.

Question 19

Explain the concept of Top-Down Parsing in detail. Discuss Recursive Descent …

Accepted Answer

A deep mathematical breakdown of Top-Down Parsing architectures, explicitly differentiating the backtracking inefficiency of Recursive Descent Parsing from the highly deterministic, table-driven execution of LL(1) Predictive Parsing.

Question 20

(a) Explain the concept of Bottom-Up Parsing. (b) Discuss LR parsing techniqu…

Accepted Answer

A definitive engineering analysis of Bottom-Up (Shift-Reduce) Parsing, thoroughly exploring the mathematical hierarchies and state machine complexities of SLR, CLR(1), and LALR parsing algorithms.

Question 21

Explain Syntax-Directed Definitions (SDD) and Syntax-Directed Translation (SD…

Accepted Answer

A rigorous exposition on Syntax-Directed Definitions (SDD) and Translation (SDT), explaining the critical mathematical difference between Synthesized and Inherited attributes, accompanied by an arithmetic expression translation model.

Question 22

Explain Code Optimization techniques in detail. Discuss local optimizations a…

Accepted Answer

A highly technical breakdown of Code Optimization algorithms, explicitly analyzing Machine-Independent optimizations like Constant Folding, Dead-Code Elimination, and advanced Loop Optimizations (Code Motion, Induction Variables).

Compiler Design