af4d94c85a
* winch(x64): Initial implementation for function calls This change adds the main building blocks for calling locally defined functions. Support for function imports will be added iteratively after this change lands and once trampolines are supported. To support function calls, this change introduces the following functionality to the MacroAssembler: * `pop` to pop the machine stack into a given register, which in the case of this change, translates to the x64 pop instruction. * `call` to a emit a call to locally defined functions. * `address_from_sp` to construct memory addresses with the SP as a base. * `free_stack` to emit the necessary instrunctions to claim stack space. The heavy lifting of setting up and emitting the function call is done through the implementation of `FnCall`. * Fix spill behaviour in function calls and add more documentation This commits adds a more detailed documentation to the `call.rs` module. It also fixes a couple of bugs, mainly: * The previous commit didn't account for memory addresses used as arguments for the function call, any memory entry in the value stack used as a function argument should be tracked and then used to claim that memory when the function call ends. We could `pop` and do this implicitly, but we can also track this down and emit a single instruction to decrement the stack pointer, which will result in better code. * Introduce a differentiator between addresses relative or absolute to the stack pointer. When passing arguments in the stack -- assuming that SP at that point is aligned for the function call -- we should store the arguments relative to the absolute position of the stack pointer and when addressing a memory entry in the Wasm value stack, we should use an address relative to the offset and the position of the stack pointer. * Simplify tracking of the stack space needed for emitting a function call
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 (locally) 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!
(Note: make sure you installed Rust using the rustup method in the official
instructions above, and do not have a copy of the Rust toolchain installed on
your system in some other way as well (e.g. the system package manager). Otherwise, the rustup target add...
command may not install the target for the correct copy of Rust.)
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.
-
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.
Languages supported by the Bytecode Alliance:
- 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 - Ruby - the
wasmtimegem
Languages supported by the community:
- Elixir - the
wasmexhex package
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.