5df8840483
`lucetc` currently *almost*, but not quite, works with the new x64 backend; the only missing piece is support for the particular instructions emitted as part of its prologue stack-check. We do not normally see `brff`, `brif`, or `ifcmp_sp` in CLIF generated by `cranelift-wasm` without the old-backend legalization rules, so these were not supported in the new x64 backend as they were not necessary for Wasm MVP support. Using them resulted in an `unimplemented!()` panic. This PR adds support for `brff` and `brif` analogously to how AArch64 implements them, by pattern-matching the `ifcmp` / `ffcmp` directly. Then `ifcmp_sp` is a straightforward variant of `ifcmp`. Along the way, this also removes the notion of "fallthrough block" from the branch-group lowering method; instead, `fallthrough` instructions are handled as normal branches to their explicitly-provided targets, which (in the original CLIF) match the fallthrough block. The reason for this is that the block reordering done as part of lowering can change the fallthrough block. We were not using `fallthrough` instructions in the output produced by `cranelift-wasm`, so this, too, was not previously caught. With these changes, the `lucetc` crate in Lucet passes all tests with the `x64` feature-flag added to its `cranelift-codegen` dependency.
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, generate code blazingly fast with Lightbeam, or interpret it at runtime, Wasmtime has you covered for all your wasm-executing needs.
-
WASI. Wasmtime supports a rich set of APIs for interacting with the host environment through the WASI standard.
-
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 - 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.