411f3d60f3
I ran across a case in Wasmtime today where a poor error message came
out of the CLI. For example before this commit you would get:
$ cargo run wast --wasm-features component-model foo.wast
error: Invalid value "wast" for '<MODULE>': module name cannot be the same as a subcommand
and now after this commit you get:
$ cargo run wast --wasm-features component-model foo.wast
error: Invalid value "component-model" for '--wasm-features <FEATURE,FEATURE,...>': unsupported WebAssembly feature 'component-model'
I believe this was an accidental regression from #4082 since Wasmtime
0.36.0 produces the error message as expected.
I opted to invert the conditional logic for falling back to the `run`
subcommand. Instead of having a small set of error kinds that print the
first-level error a small set of error kinds are now used to fall back
to the `run` subcommand by default. My hope is that as `ErrorKind` is
extended over time with various sorts of errors of parsing argumenst
this'll be more robust because most of the time we want the CLI
invocation to print out the normal CLI error, it's only in a select few
cases that using `run` is likely to succeed.
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.
-
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 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.