Ethereum Virtual Machine (EVM) in Zig

<Breaking changes everyday, do not use in production!>

This project is an experimental implementation of the Ethereum Virtual Machine (EVM) using the Zig programming language. It aims to provide a lightweight, modular, and educational EVM implementation for learning and experimentation purposes.

Features

• Basic EVM opcodes implementation
• Support for contract deployment and execution
• Simplified account and storage model
• Gas calculation and management
• Support for precompiled contracts
• Dynamic opcode loading from separate files
• Example implementation of a simple ERC20-like token contract

Prerequisites

• Zig compiler (latest version recommended)
• Basic understanding of Ethereum and EVM concepts

Project Structure

.
├── src/
│   ├── main.zig
│   ├── bigint.zig
│   ├── memory.zig
│   ├── stack.zig
│   └── opcodes/
│       ├── add.zig
│       ├── sub.zig
│       ├── mul.zig
│       └── ...
├── README.md
└── build.zig

Setup

1. Clone the repository:

   git clone https://github.com/yourusername/zig-evm.git
   cd zig-evm
   

2. Build the project:

   zig build-exe src/main.zig
   

Usage

Run the compiled executable:

./main

This will execute the example scenario defined in main.zig, which includes:

1. Deploying an ERC20-like contract
2. Checking the balance of an address
3. Performing a token transfer
4. Checking the balance after the transfer

Extending the EVM

Adding new opcodes

1. Create a new file in the src/opcodes/ directory (e.g., src/opcodes/newop.zig)
2. Implement the opcode following the structure in existing opcode files
3. The EVM will automatically load and use the new opcode

Modifying gas costs

Adjust the useGas function calls in the opcode implementations to change gas costs for operations.

Implementing more precompiled contracts

Add new precompiled contracts in the loadPrecompiled function in main.zig.

Limitations

This is an experimental implementation and has several limitations:

• Not all EVM opcodes are implemented
• Gas calculation is simplified
• The state and storage models are basic
• Error handling and edge cases may not be fully covered
• Performance optimizations are not implemented

Contributing

Contributions to this experimental project are welcome! Please feel free to submit issues, feature requests, or pull requests.

Disclaimer

This project is for educational and experimental purposes only. It is not intended for use in production environments or with real cryptocurrency transactions.

License

This project is open-source and available under the MIT License.