6ef09359b0
* Refactor and improve safety of C API This commit is intended to be a relatively large refactoring of the C API which is targeted at improving the safety of our C API definitions. Not all of the APIs have been updated yet but this is intended to be the start. The goal here is to make as many functions safe as we can, expressing inputs/outputs as native Rust types rather than raw pointers wherever possible. For example instead of `*const wasm_foo_t` we'd take `&wasm_foo_t`. Instead of returning `*mut wasm_foo_t` we'd return `Box<wasm_foo_t>`. No ABI/API changes are intended from this commit, it's supposed to only change how we define all these functions internally. This commit also additionally implements a few more API bindings for exposed vector types by unifying everything into one macro. Finally, this commit moves many internal caches in the C API to the `OnceCell` type which provides a safe interface for one-time initialization. * Split apart monolithic C API `lib.rs` This commit splits the monolithic `src/lib.rs` in the C API crate into lots of smaller files. The goal here is to make this a bit more readable and digestable. Each module now contains only API bindings for a particular type, roughly organized around the grouping in the wasm.h header file already. A few more extensions were added, such as filling out `*_as_*` conversions with both const and non-const versions. Additionally many APIs were made safer in the same style as the previous commit, generally preferring Rust types rather than raw pointer types. Overall no functional change is intended here, it should be mostly just code movement and minor refactorings! * Make a few wasi C bindings safer Use safe Rust types where we can and touch up a few APIs here and there. * Implement `wasm_*type_as_externtype*` APIs This commit restructures `wasm_externtype_t` to be similar to `wasm_extern_t` so type conversion between the `*_extern_*` variants to the concrete variants are all simple casts. (checked in the case of general to concrete, of course). * Consistently imlpement host info functions in the API This commit adds a small macro crate which is then used to consistently define the various host-info-related functions in the C API. The goal here is to try to mirror what the `wasm.h` header provides to provide a full implementation of the header.
wasmtime
A standalone runtime for WebAssembly
A Bytecode Alliance project
Guide | Contributing | Website | Chat
Installation
The Wasmtime CLI can be installed on Linux and macOS with a small install script:
$ curl https://wasmtime.dev/install.sh -sSf | bash
Windows or otherwise interested users can download installers and binaries directly from the GitHub Releases page.
Example
If you've got the Rust compiler installed then you can take some Rust source code:
fn main() {
println!("Hello, world!");
}
and compile/run it with:
$ rustup target add wasm32-wasi
$ rustc hello.rs --target wasm32-wasi
$ wasmtime hello.wasm
Hello, world!
Features
-
Lightweight. Wasmtime is a standalone runtime for WebAssembly that scales with your needs. It fits on tiny chips as well as makes use of huge servers. Wasmtime can be embedded into almost any application too.
-
Fast. Wasmtime is built on the optimizing Cranelift code generator to quickly generate high-quality machine code at runtime.
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Configurable. Whether you need to precompile your wasm ahead of time, generate code blazingly fast with Lightbeam, or interpret it at runtime, Wasmtime has you covered for all your wasm-executing needs.
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WASI. Wasmtime supports a rich set of APIs for interacting with the host environment through the WASI standard.
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Standards Compliant. Wasmtime passes the official WebAssembly test suite, implements the official C API of wasm, and implements future proposals to WebAssembly as well. Wasmtime developers are intimately engaged with the WebAssembly standards process all along the way too.
Documentation
📚 Read the Wasmtime guide here! 📚
The wasmtime guide is the best starting point to learn about what Wasmtime can do for you or help answer your questions about Wasmtime. If you're curious in contributing to Wasmtime, it can also help you do that!.
It's Wasmtime.