77ab99d3b0
* Cleanups to cranelift-frontend SSA construction * Encode sealed/undef_variables relationship in type A block can't have any undef_variables if it is sealed. It's useful to make that fact explicit in the types so that any time either value is used, it's clear that we should think about the other one too. In addition, encoding this fact in an enum type lets Rust apply an optimization that reduces the size of SSABlockData by 8 bytes, making it fit in a 64-byte cache line. I haven't taken the extra step of making SSABlockData be 64-byte aligned because 1) it doesn't seem to have a performance impact and b) doing so makes other structures quite a bit bigger. * Simplify finish_predecessors_lookup Using Vec::drain is more concise than a combination of iter().rev().take() followed by Vec::truncate. And in this case it doesn't matter what order we examine the results in, because we just want to know if they're all equal, so we might as well iterate forward instead of in reverse. There's no need for the ZeroOneOrMore enum. Instead, there are only two cases: either we have a single value to use for the variable (possibly synthesized as a constant zero), or we need to add a block parameter in every predecessor. Pre-filtering the results iterator to eliminate the sentinel makes it easy to identify how many distinct definitions this variable has. iter.next() indicates if there are any definitions at all, and then iter.all() is a clear way to express that we want to know if the remaining definitions are the same as the first one. * Simplify append_jump_argument * Avoid assigning default() into SecondaryMap This eliminates some redundant reads and writes. * cranelift-frontend: Construct with default() This eliminates a bunch of boilerplate in favor of a built in `derive` macro. Also I'm deleting an import that had the comment "FIXME: Remove in edition2021", which we've been using everywhere since April. * Fix tests
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
-
Fast. Wasmtime is built on the optimizing Cranelift code generator to quickly generate high-quality machine code either at runtime or ahead-of-time. Wasmtime is optimized for efficient instantiation, low-overhead calls between the embedder and wasm, and scalability of concurrent instances.
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Secure. Wasmtime's development is strongly focused on correctness and security. Building on top of Rust's runtime safety guarantees, each Wasmtime feature goes through careful review and consideration via an RFC process. Once features are designed and implemented, they undergo 24/7 fuzzing donated by Google's OSS Fuzz. As features stabilize they become part of a release, and when things go wrong we have a well-defined security policy in place to quickly mitigate and patch any issues. We follow best practices for defense-in-depth and integrate protections and mitigations for issues like Spectre. Finally, we're working to push the state-of-the-art by collaborating with academic researchers to formally verify critical parts of Wasmtime and Cranelift.
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Configurable. Wasmtime uses sensible defaults, but can also be configured to provide more fine-grained control over things like CPU and memory consumption. Whether you want to run Wasmtime in a tiny environment or on massive servers with many concurrent instances, we've got you covered.
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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, CMake orwasmtimeConan 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.