wasm-interpreter

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A minimal in-place interpreter for WebAssembly bytecode (almost without) dependencies while being no_std.

Features

• In-place interpretation: No intermediate parsing step. This allows for fast start-up times.
• no_std support: The interpreter requires only Rust's core and alloc libraries allowing its use in various environments, such as bare-metal systems.
• Minimal dependencies: The interpreter requires only two dependencies: log, libm.
• Compliance with specification: The interpreter passes almost all test from the official WebAssembly testsuite. Only SIMD instructions are missing.
• Host functions: The host system can provide functions for Wasm code to call.

For information on other features, visit our requirements page.

Planned

• Fuel & resumable execution: A fuel mechanism is used to halt execution once fuel runs out. Then fuel can be refilled and execution resumed.
• C bindings: The interpreter can be used from C code.
• Migratability: Wasm instances can be transferred between systems during their execution.
• Threading: There are multiple threading proposals, but we have not yet chosen a specific one. Some options are shared-everything-threads, threads, wasi-threads.

Not planned

Multi-memory proposal, GC proposal

Resources

• A fast in-place interpreter by Ben L. Titzer: https://arxiv.org/abs/2205.01183
• WebAssembly spec: https://webassembly.github.io/spec/core/index.html
• WebAssembly Opcode Table: https://pengowray.github.io/wasm-ops/
• Compiler/Interpreter Know-How Gist Compilation: https://gist.github.com/o11c/6b08643335388bbab0228db763f99219
• Mozilla Developer Network WebAssembly Homepage: https://developer.mozilla.org/en-US/docs/WebAssembly

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT License (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Copyright

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