Overview

C Assembler is a two-pass assembler written in C, designed as a comprehensive systems programming project. It demonstrates mastery of bit-field methods, dynamic memory management, and modular programming architecture. The assembler processes assembly language source files and generates corresponding machine code through a sophisticated two-pass compilation process.

Key Features

• Two-Pass Architecture: Implements a complete two-pass assembly algorithm for symbol resolution
• Memory Management: Efficient dynamic memory allocation and deallocation
• Modular Design: Clean separation of concerns across multiple source files
• Robust Error Handling: Comprehensive syntax and semantic error detection
• Standards Compliant: Written in standard C with portable code practices

Architecture & File Structure

Core Components

• assembler.c: Main entry point containing main() and executePasses() orchestration
• assemblerHelper.c/.h: Argument validation and pass control logic
• dataStructure.c/.h: Core data structures (line/label structs) and initialization routines

Processing Modules

• firstPass.c/.h: First pass implementation handling symbol table construction
• secondPassHelper.c/.h: Second pass logic for code generation and symbol resolution
• reservedWords.c/.h: Assembly language keyword recognition and instruction parsing
• strHandle.c/.h: String manipulation and parsing utilities

Output Generation

• outputPrint.c/.h: Machine code generation and output file creation

Build System

• makefile: Automated build configuration with dependency management

Installation & Usage

Prerequisites

• GCC compiler (or compatible C compiler)
• Make utility
• POSIX-compliant system (Linux/Unix/macOS)

Building

# Clone the repository
git clone <repository-url>
cd C_Assembler

# Compile the project
make

# Clean build artifacts (optional)
make clean

Running the Assembler

# Basic usage
./assembler source_file.as

# Example with multiple files
./assembler prog1.as prog2.as prog3.as

Input/Output

• Input: Assembly source files with .as extension
• Output: Generated files include:
  • .ob - Object file (machine code)
  • .ext - External symbols file
  • .ent - Entry symbols file

Assembly Language Support

The assembler supports a custom assembly language instruction set including:

• Data manipulation instructions
• Control flow operations
• Memory addressing modes
• Symbol definitions and references
• Directive handling (.data, .string, .entry, .extern)

Error Handling

Comprehensive error detection including:

• Syntax errors (invalid instruction format)
• Semantic errors (undefined symbols, duplicate labels)
• Memory allocation failures
• File I/O errors
• Invalid command-line arguments

Development Notes

This project was developed as the final assignment for a Systems Programming Laboratory course, focusing on:

• Low-level programming concepts
• Assembly language processing
• File I/O operations
• Data structure design
• Modular programming practices

Project Statistics

• Final Grade: 95/100
• Language: C
• Architecture: Modular, multi-file design
• Compilation: Standard makefile with dependency tracking

Contributing

Contributions are welcome! Please follow these guidelines:

1. Fork the repository
2. Create a feature branch
3. Implement changes with appropriate tests
4. Submit a pull request with detailed description

License

This project is part of academic coursework. Please respect academic integrity policies when referencing or using this code.

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Built with precision and attention to detail as a demonstration of systems programming mastery.