A WebAssembly interpreter written from scratch.
This project aims to build a serious, fully spec-compliant, performant WASM interpreter whose entire execution state can be serialized, suspended, and restored.
See demo
Each fork snapshots the entire WebAssembly execution state, spawns a brand new process, and resumes exactly where it left off.
As a pure interpreter, it is safe to assume gabagool is spec compliant. gabagool is tested against the WebAssembly spec test suite. 1,960 tests pass out of 2,049 (96%). gabagool passes on arithmetic, control flow, memory, tables, globals, function references, imports/exports, and exceptions. Remaining tests involve supporting SIMD and garbage collection.
gabagool is not focused on performance optimization. No serious profiling/benchmarking has been done (yet!). That said, the goal is to make gabagool performant while preserving its snapshot friendly execution model. gabagool already lowers WASM instructions into a compact, serializable intermediate representation. The most interesting direction now is an experimental JIT compiler based on copy and patch compilation.
Current work focuses on how gabagool interacts with its host environment. This includes a minimal, virtualized WASI Preview 1 implementation whose state can be snapshotted and restored alongside the interpreter.
# run the core test suite
uv run download-core-tests.py
cargo t --features core-tests --test core_tests
# compare against the committed CI baseline
python3 check-core-tests.py
# lock newly passing assertions and cases into the baseline
python3 check-core-tests.py --update
# run the component test suite
# you need wasm-tools installed!
cd tests/components && bash fetch_components.sh
cargo t --features component-tests
# run an example wasm program
cargo r -- ./test-programs/stair_climb.wasm stair_climb 20https://webassembly.github.io/spec/core/
bytecodealliance/wasmtime#3017
bytecodealliance/wasmtime#4002
https://www.infoq.com/podcasts/web-assembly-component-model/
https://blog.sunfishcode.online/what-is-a-wasm-component/
https://www.fermyon.com/blog/webassembly-component-model
https://github.com/WebAssembly/component-model/blob/main/design/mvp/Explainer.md
https://github.com/WebAssembly/component-model/blob/main/design/mvp/Binary.md
https://github.com/WebAssembly/component-model/blob/main/design/mvp/CanonicalABI.md
https://fredrikbk.com/publications/copy-and-patch.pdf
https://www.youtube.com/watch?v=HxSHIpEQRjs