WebAssembly has emerged as a game-changing technology that allows developers to compile code for the web, enabling high-performance applications directly in the browser. Fizzy is a powerful WebAssembly interpreter written in C++ that aims to make the development and execution of WebAssembly binaries as fast and efficient as possible. In this article, we will walk you through the steps to build and use Fizzy, along with troubleshooting tips to overcome common issues.

Goals of Fizzy

Fizzy is designed with several key objectives in mind:

• Code Quality: Fizzy maintains a clean C++17 codebase without external dependencies.
• Simplicity: The interpreter solely implements WebAssembly 1.0 and supports only binary encodings.
• Conformance: It boasts a unit test coverage of 99% and can pass official WebAssembly test suites.
• Deterministic Applications Support: Primarily designed for blockchain applications with optional runtime metering.

Building Fizzy

To build Fizzy, you’ll need CMake as a build system. Here are the steps:

sh
$ mkdir build
$ cd build
$ cmake ..
$ cmake --build .

Using the C API

Fizzy provides a public C API to facilitate embedding its engine within your applications. Below is a simple example that executes a function named main from a WebAssembly binary:

#include 

bool execute_main(const uint8_t* wasm_binary, size_t wasm_binary_size) {
    const FizzyModule* module = fizzy_parse(wasm_binary, wasm_binary_size);
    
    uint32_t main_fn_index;
    if (!fizzy_find_exported_function_index(module, "main", main_fn_index))
        return false;

    FizzyInstance* instance = fizzy_instantiate(module, NULL, 0, NULL, NULL, NULL, 0);
    const FizzyExecutionResult result = fizzy_execute(instance, main_fn_index, NULL, 0);
    
    if (result.trapped)
        return false;

    fizzy_free_instance(instance);
    return true;
}

This code can be likened to solving a mystery. Imagine you have an encrypted message (the WASM binary) that you need to decode. The interpreter is the detective who first understands the context (parsing the binary), identifies specific clues (finding the main function), solves the mystery (instantiation and execution), and finally closes the case (releasing resources)!

CMake Integration

Fizzy provides a CMake package to allow seamless integration into projects. You can set it up in your project using:

cmake
find_package(fizzy CONFIG REQUIRED)
...
target_link_libraries(app_name PRIVATE fizzy::fizzy)

Rust Bindings

If you’re working with Rust, you can also leverage Fizzy’s Rust bindings. The library is published on crates.io, making it easily accessible for your projects.

Understanding WASI

Building with the FIZZY_WASI option allows you to implement the WASI API, which is a limited subset of features for executing WASI-compatible binaries. Similar build commands apply here:

sh
$ mkdir build
$ cd build
$ cmake -DFIZZY_WASI=ON ..
$ cmake --build .

Try it out with a simple Hello World example stored in helloworld.wasm.

Testing Tools

Fizzy includes several testing utilities to ensure compliance and performance:

• fizzy-bench: To run benchmarks.
• fizzy-spectests: Executes official WebAssembly tests.
• fizzy-testfloat: Tests for floating-point instructions.
• fizzy-unittests: A robust unit test suite.

Troubleshooting Tips

While using Fizzy, you might encounter some issues. Below are some troubleshooting ideas:

• Ensure your CMake version is up-to-date as older versions might lead to compatibility issues.
• If you’re having trouble with floating-point operations, double-check your rounding settings. Make sure they align with the expected IEEE 754 standard.
• In case of execution failures, verify that your WASM binaries are correctly structured and not corrupted.

For more insights, updates, or to collaborate on AI development projects, stay connected with fxis.ai.

Conclusion

Fizzy is a powerful tool in the WebAssembly ecosystem, offering easy integration, robust performance, and a strong focus on compliance. By following the instructions provided, you’ll be well on your way to harnessing the power of WebAssembly in your applications. At fxis.ai, we believe that such advancements are crucial for the future of AI, as they enable more comprehensive and effective solutions. Our team is continually exploring new methodologies to push the envelope in artificial intelligence, ensuring that our clients benefit from the latest technological innovations.