C Compiler Design and Implementation

A from-scratch C compiler implemented in C++, demonstrating the full compilation pipeline from source code to target assembly.
The project emphasizes modular design, educational clarity, and correctness, making it suitable for academic use and compiler fundamentals study.

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Overview

This compiler processes C source code through all standard compilation phases:

• Lexical Analysis – Token generation
• Syntax Analysis – Parsing and AST construction
• Semantic Analysis – Type checking and scope validation
• Intermediate Code Generation – Three Address Code (TAC)
• Target Code Generation – MIPS-like assembly output

The implementation mirrors the structure of industrial compilers while remaining readable and extensible.

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Features

• Complete multi-phase compiler pipeline
• Recursive descent parser with operator precedence
• Hierarchical symbol table with scope management
• Semantic analysis with detailed error reporting
• Three Address Code (TAC) intermediate representation
• MIPS-style assembly code generation
• Clear diagnostics with source line and column tracking
• Modular and extensible architecture

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Supported C Subset

Data Types

• int
• float
• char
• void

Language Constructs

• Variable declarations and assignments
• Arithmetic, relational, and logical expressions
• Control flow:
  • if / else
  • while
  • for
  • do-while
• Functions:
  • Definition
  • Parameters
  • Return values
  • Recursion
• Basic I/O:
  • printf
  • scanf

Partial / Not Implemented

• Arrays (basic support)
• Pointers (limited)
• Structs, unions, typedef
• Preprocessor directives

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Compiler Architecture

C Source Code
↓
Lexical Analyzer
↓
Syntax Analyzer (Parser)
↓
Semantic Analyzer
↓
Intermediate Code Generator (TAC)
↓
Target Code Generator
↓
MIPS-like Assembly Output

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Build

git clone https://github.com/Yam1nX/compiler.git
cd compiler
g++ compiler.cpp -o compiler

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Usage

./compiler input.c

Output Includes

• Token stream
• Three Address Code (TAC)
• Generated assembly code

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Example

Input (input.c)

int main() {
    int a = 10;
    int b = 20;
    int sum = a + b;
    printf("Sum = %d\n", sum);
    return 0;
}

Output

• Tokens generated
• TAC instructions
• MIPS-style assembly code

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Testing

• 30+ test programs covering:

  • Expressions
  • Control flow
  • Functions
  • Semantic errors

• Lexical, syntax, and semantic error validation

• Comparison against reference compiler outputs

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Future Enhancements

• Full support for arrays, pointers, structs, and unions

• Advanced optimizations:

  • Constant folding
  • Dead code elimination
  • Better register allocation

• Support for additional targets (x86-64, ARM, WebAssembly)

• Basic linker and preprocessor support

• Enhanced diagnostics and warnings

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Author

Name: Ashabul Yamin Tuhin Course: Compiler Lab Department: Computer Science and Engineering

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