A compiler is a software tool that translates high-level programming code into a lower-level representation that can be executed by a computer.
The primary function of a compiler is to convert source code written in a high-level language (such as C, C++, Java) into machine code or assembly language, which can be understood and executed by the computer’s processor.
The compilation process consists of two main phases:
- Analysis phase
- Synthesis phase
1. Analysis Phase:
This phase involves breaking down the source code, verifying its correctness, and understanding its structure and meaning.
- Lexical analysis: Breaking the code into individual tokens (keywords, identifiers, operators, literals) and removing unnecessary elements like white spaces and comments.
- Syntax analysis: Verifying the code’s syntax by checking the arrangement of tokens according to the language’s grammar rules and building a parse tree or abstract syntax tree (AST).
- Semantic analysis: Checking the code’s meaning and context, including type checking and symbol table construction.
2. Synthesis Phase:
This phase focuses on generating the target code from the analyzed source code.
- Intermediate code generation: Creating an intermediate representation of the source code, often platform-independent and more optimized.
- Optimization: Applying various techniques to improve the efficiency and performance of the intermediate code.
- Code generation: Generating the final target code, either machine code specific to the target hardware or assembly language resembling the machine code.
Once the compilation process is complete, the compiler produces an executable or binary file that can be directly executed by the computer.
Compilers enable programmers to write code in higher-level languages, abstracting the complexities of the underlying hardware. They also allow for efficient and portable software development.