GDScript Compiler

A direct-to-machine-code compiler for GDScript, the scripting language used in the Godot game engine. This compiler translates GDScript source code directly into native machine code without transpiling to another high-level language.

Features

Core Compilation Pipeline

• Lexical Analysis: Tokenizes GDScript source code with support for all GDScript syntax
• Syntax Analysis: Builds Abstract Syntax Tree (AST) using recursive descent parsing
• Semantic Analysis: Performs type checking, symbol resolution, and semantic validation
• Code Generation: Generates native machine code with register allocation and optimization

Language Support

• Data Types: int, float, String, bool, Array, Dictionary, Variant
• Control Flow: if/else, while, for, match statements
• Functions: Function declarations with parameters and return types
• Classes: Class definitions with inheritance, methods, and properties
• Signals: GDScript signal declarations and handling
• Built-in Functions: print(), len(), range(), str(), int(), float()

Advanced Features

• Type Inference: Automatic type deduction where possible
• Register Allocation: Efficient register usage with virtual register support
• Code Optimization: Dead code elimination and constant folding
• Error Reporting: Comprehensive error messages with line numbers
• Cross-Platform: Supports x86_64 and ARM64 architectures

Project Structure

GDScript Compiler/
├── main.cpp              # Main compiler entry point
├── lexer.h/.cpp          # Lexical analyzer
├── parser.h/.cpp         # Syntax analyzer and AST builder
├── semantic_analyzer.h/.cpp # Semantic analysis and type checking
├── code_generator.h/.cpp # Machine code generation
├── examples/             # Example GDScript files
├── Makefile              # Build system
├── clean.sh              # Cleanup script
└── README.md             # This file

Building the Compiler

Prerequisites

• C++17 compatible compiler (GCC 7+ or Clang 5+)
• Make build system
• POSIX-compliant operating system (Linux, macOS, BSD)

Build Commands

# Build the compiler
make

# Clean build artifacts
make clean

# Debug build with symbols
make debug

# Optimized release build
make release

# Run basic tests
make test

# Install to system path
make install

Usage

Basic Compilation

# Compile GDScript file to machine code
./bin/gdscript-compiler input.gd output

# This generates:
# - output.s   (assembly code)
# - output.o   (object file)
# - output     (executable)

Example GDScript Code

See the examples/ directory for sample GDScript files that can be compiled with this compiler.

Command Line Options

Usage: gdscript-compiler [options] <input.gd> <output>

Options:
  -h, --help     Show help message
  -v, --version  Show compiler version
  -O, --optimize Enable optimizations
  -g, --debug    Include debug information
  -S, --asm-only Generate assembly only
  -c, --compile  Generate object file only

Architecture

Compilation Phases

1. Lexical Analysis (lexer.cpp)

   • Tokenizes source code into meaningful symbols
   • Handles keywords, operators, literals, and identifiers
   • Manages indentation-based syntax

2. Syntax Analysis (parser.cpp)

   • Builds Abstract Syntax Tree (AST)
   • Implements recursive descent parser
   • Handles operator precedence and associativity

3. Semantic Analysis (semantic_analyzer.cpp)

   • Type checking and inference
   • Symbol table management
   • Scope resolution
   • Error detection

4. Code Generation (code_generator.cpp)

   • Intermediate representation (IR) generation
   • Register allocation
   • Machine code emission
   • Optimization passes

Platform Support

Supported Architectures

• x86_64: Intel/AMD 64-bit processors
• ARM64: Apple Silicon and ARM64 processors

Operating Systems

• Linux: All major distributions
• macOS: Intel and Apple Silicon Macs
• Windows: PE executable format support

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests for new functionality
5. Ensure all tests pass
6. Submit a pull request

NOTES

System calls are not fully implemented yet..

License

This project is open source. See the LICENSE file for details.