Arrange the following phases of a compiler as per their order of execution (start to end)

(A) Target code generation

(B) Syntax Analysis

(C) Code optimization

(D) Semantic Analysis

(E) Lexical Analysis

Choose the correct answer from the options given below:

The correct answer is (E), (B), (D), (C), (A)

EXPLANATION:

• Lexical Analysis (E):
  • This is the first phase where the source code is analyzed to recognize and tokenize the basic elements, such as keywords, identifiers, literals, and operators.
• Syntax Analysis (B):
  • In this phase, the compiler checks whether the tokens generated by the lexical analysis form a valid syntactic structure according to the grammar of the programming language. It builds a parse tree or syntax tree to represent the structure.
• Semantic Analysis (D):
  • This phase ensures that the program makes sense semantically. It checks for things like variable declarations, type compatibility, and other semantic rules. The goal is to ensure that the program has a meaningful interpretation.
• Code Optimization (C):
  • This phase is not always mandatory, but it involves enhancing the intermediate code to make it more efficient. Various techniques are applied to optimize the code, such as loop unrolling, constant folding, and dead code elimination.
• Target Code Generation (A):
  • Once the syntax and semantics are verified, the compiler generates an intermediate code or target code. This code is usually in a form that is easier to optimize and convert into machine code.

So, the correct order is (E), (B), (D), (C), (A).