* Replace the global-exports mechanism with a caller-vmctx mechanism. This eliminates the global exports mechanism, and instead adds a caller-vmctx argument to wasm functions so that WASI can obtain the memory and other things from the caller rather than looking them up in a global registry. This replaces #390. * Fixup some merge conflicts * Rustfmt * Ensure VMContext is aligned to 16 bytes With the removal of `global_exports` it "just so happens" that this isn't happening naturally any more. * Fixup some bugs with double vmctx in wasmtime crate * Trampoline stub needed adjusting * Use pointer type instead of always using I64 for caller vmctx * Don't store `ir::Signature` in `Func` since we don't know the pointer size at creation time. * Skip the first 2 arguments in IR signatures since that's the two vmctx parameters. * Update cranelift to 0.56.0 * Handle more merge conflicts * Rustfmt Co-authored-by: Alex Crichton <alex@alexcrichton.com>
Wasmtime: a WebAssembly Runtime
A Bytecode Alliance project
Wasmtime is a standalone wasm-only optimizing runtime for WebAssembly and WASI. It runs WebAssembly code outside of the Web, and can be used both as a command-line utility or as a library embedded in a larger application.
To get started, visit wasmtime.dev.
There are Rust, C, and C++ toolchains that can compile programs with WASI. See the WASI intro for more information, and the WASI tutorial for a tutorial on compiling and running programs using WASI and wasmtime, as well as an overview of the filesystem sandboxing system.
Wasmtime passes the WebAssembly spec testsuite. To run it, update the
tests/spec_testsuite submodule with git submodule update --remote, and it
will be run as part of cargo test.
Wasmtime does not yet implement Spectre mitigations, however this is a subject of ongoing research.
Additional goals for Wasmtime include:
- Support a variety of host APIs (not just WASI), with fast calling sequences, and develop proposals for additional API modules to be part of WASI.
- Facilitate development and testing around the Cranelift and Lightbeam JITs, and other WebAssembly execution strategies.
- Develop a native ABI used for compiling WebAssembly suitable for use in both JIT and AOT to native object files.
Including Wasmtime in your project
Wasmtime exposes an API for embedding as a library through the wasmtime subcrate,
which contains both a high-level and safe Rust API, as well as a C-compatible API
compatible with the proposed WebAssembly C API.
For more information, see the Rust API embedding chapter of the Wasmtime documentation.
It's Wasmtime.