ca0e8d0a1d
In #3721, we have been discussing what to do about the ARM32 backend in Cranelift. Currently, this backend supports only 32-bit types, which is insufficient for full Wasm-MVP; it's missing other critical bits, like floating-point support; and it has only ever been exercised, AFAIK, via the filetests for the individual CLIF instructions that are implemented. We were very very thankful for the original contribution of this backend, even in its partial state, and we had hoped at the time that we could eventually mature it in-tree until it supported e.g. Wasm and other use-cases. But that hasn't yet happened -- to the blame of no-one, to be clear, we just haven't had a contributor with sufficient time. Unfortunately, the existence of the backend and lack of active maintainer now potentially pose a bit of a burden as we hope to make continuing changes to the backend framework. For example, the ISLE migration, and the use of regalloc2 that it will allow, would need all of the existing lowering patterns in the hand-written ARM32 backend to be rewritten as ISLE rules. Given that we don't currently have the resources to do this, we think it's probably best if we, sadly, for now remove this partial backend. This is not in any way a statement of what we might accept in the future, though. If, in the future, an ARM32 backend updated to our latest codebase with an active maintainer were to appear, we'd be happy to merge it (and likewise for any other architecture!). But for now, this is probably the best path. Thanks again to the original contributor @jmkrauz and we hope that this work can eventually be brought back and reused if someone has the time to do so!
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.
-
Configurable. Whether you need to precompile your wasm ahead of time, 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.
Language Support
You can use Wasmtime from a variety of different languages through embeddings of the implementation:
- Rust - the
wasmtimecrate - C - the
wasm.h,wasi.h, andwasmtime.hheaders or usewasmtimeConan package - [C++] - the
wasmtime-cpprepository or usewasmtime-cppConan package - Python - the
wasmtimePyPI package - .NET - the
WasmtimeNuGet package - Go - the
wasmtime-gorepository
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.