Rust WebAssembly VM

The Rust WASM (WebAssembly) VM (Virtual Machine) project demonstrates the interop between Rust and JavaScript using WebAssembly. It showcases a simple Virtual Machine implemented in Rust, with the ability to store and retrieve values in registers. This documentation provides an overview of the project, explains how to get started, describes the Rust code structure, and provides code samples with explanations.

Table of Contents

• Rust WebAssembly VM
  • Table of Contents
  • Getting Started
    • Prerequisites
  • Rust Code
    • VirtualMachine Struct
      • new
      • get_register_value
      • store_value_in_register
  • JavaScript Code
    • runVirtualMachine Function
      • Example:
  • License

Getting Started

This setup involves creating a Rust library project, implementing the virtual machine logic, building it into a WebAssembly module using wasm-pack, and integrating it into an HTML file for execution in the browser.

Prerequisites

Install the wasm-pack module, by running the following command:

curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh

To run the project, follow these steps:

1. Install Rust if you haven't already.

2. Open a terminal and navigate to the project directory.

3. Build the WebAssembly module and JavaScript interop code by running the following command:

   wasm-pack build --target web --out-dir ./dist

4. Open the js-wasm-vm-interop.html file in your web browser to see the output in the browser console.

Rust Code

The Rust code resides in the lib.rs file. It defines a VirtualMachine struct with methods to interact with the virtual machine.

VirtualMachine Struct

The VirtualMachine struct represents a simple virtual machine with registers. It has the following methods:

new

The new method creates a new instance of the virtual machine.

#[wasm_bindgen]
pub fn new() -> Self {
    // Initialize the virtual machine with default register values
    VirtualMachine {
        registers: [0; 16],
    }
}

get_register_value

The get_register_value method retrieves the value stored in the specified register.

#[wasm_bindgen]
pub fn get_register_value(&self, register_index: usize) -> u32 {
    // Retrieve the value from the specified register
    self.registers[register_index]
}

store_value_in_register

The store_value_in_register method stores the specified value in the specified register.

#[wasm_bindgen]
pub fn store_value_in_register(&mut self, register_index: usize, value: u32) {
    // Store the value in the specified register
    self.registers[register_index] = value;
}

JavaScript Code

The JavaScript code resides in the js-wasm-vm-interop.html file. It imports and utilizes the Rust WebAssembly module and JavaScript interop code.

runVirtualMachine Function

The runVirtualMachine function initializes the WebAssembly module, creates a new instance of the VirtualMachine class, stores a value in register 0, and retrieves the value from register 0.

Example

import init, { VirtualMachine } from './dist/rust_wasm_vm.js';

async function runVirtualMachine() {
    // Initialize the WebAssembly module
    await init();

    // Create a new instance of the virtual machine
    const vm = new VirtualMachine();

    // Store a value in register 0
    vm.store_value_in_register(0, 42);

    // Retrieve the value from register 0
    const registerValue = vm.get_register_value(0);
    console.log('Value from register 0:', registerValue);
}

runVirtualMachine().catch(console.error);

License

This project is licensed under the MIT License.

Feel free to modify and enhance the documentation according to your specific needs.