bourdaisj / unwasm

Transpile webassembly bytecode to PHP and run it

UnWasm

Do you want to code in C++ while getting absolutely zero performance gain? Do you want to code your next Wordpress plugin in Rust? Or do you want to run other programming languages on your shared PHP hosting provider? Welcome to UnWasm!

UnWasm is a PHP library which allows you to run WebAssembly on your server, without the need for any PHP extensions! UnWasm transpiles WebAssembly to native PHP, which allows for easy interoperability between your PHP and WebAssembly code.

Since the code transpiles to PHP, the performance will never exceed native PHP performance. If this is necessary for your application, we kindly refer you to wasmer-php, which is a PHP extension. UnWasm is for people who want to run their code on platforms where Wasmer is not available to them, for example on shared hosting platforms.

UnWasm is still very experimental and unstable. Do not use it in production!

Support

UnWasm is currently in development. Please view below for the currently supported language features. UnWasm will reach 1.0.0 when the binary form for WebAssembly 1.1 is fully supported.

Code Parsing	Status
.wasm	Supported
.wast	Partial

Compilation	Status
Types	Supported
Imports	Supported
Funcs	Supported
Tables	Supported
Mems	Supported
Globals	Supported
Exports	Supported
Start	Supported

Instructions	Status
Numeric	Partial
Reference	Supported
Parametric	Supported
Variable	Supported
Table	Supported
Memory	Supported
Control	Supported

Runtime	Status
Memory	Supported
Globals	Supported
Tables	Supported
Datas	Supported
Elems	Supported
Import/Export	Supported

Note: runtime funcs are managed by PHP and therefore implicitly supported.

Known caveats

• PHP integers are encoded with a bit length dependent upon the platform. This means that if you're running a 32-bit PHP installation, UnWasm currently won't support 64-bit integers.
• Integers are always encoded signed in PHP. When using large unsigned integers, this might currently result in unexpected behaviour.
• Integers in PHP don't overflow as expected. Instead, they're casted to a float. Therefore, UnWasm doesn't support integer overflow.
• When a stack overflow occurs in PHP, this cannot be gracefully caught as an exception. Therefore, the library allows for running webassembly in a memory- safe way, by creating a child PHP process and running the webassembly there. However, this incurs a performance cost during communication between the host and child process.

License

UnWasm is licensed under the Apache License, Version 2.0. Please refer to the LICENSE file for more information.

Contribute

Contributions are most welcome! Make sure your code follows the PSR-12 code style, please review these before opening a pull request. You can (partially) automate this by running the composer fix.

This project is licensed under the Apache license version 2.0. Therefore, your contributions shall be under the Apache license version 2.0 unless explicitly stated otherwise. For more information, refer to the LICENSE.