The WebAssembly spec interpreter is written in OCaml and the new crate uses `ocaml-interop` along with a small OCaml wrapper to interpret Wasm modules in-process. The build process for this crate is currently Linux-specific: it requires several OCaml packages (e.g. `apt install -y ocaml-nox ocamlbuild`) as well as `make`, `cp`, and `ar`.
40 lines
1.1 KiB
Markdown
40 lines
1.1 KiB
Markdown
wasm-spec-interpreter
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=====================
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This project shows how to use `ocaml-interop` to call into the Wasm spec
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interpreter. There are several steps to making this work:
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- building the OCaml Wasm spec interpreter as a static library
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- building a Rust-to-OCaml FFI bridge using `ocaml-interop` and a custom OCaml
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wrapper
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- linking both things into a Rust crate
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### Dependencies
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This crate only builds in an environment with:
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- `make` (the Wasm spec interpreter uses a `Makefile`)
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- `ocamlopt`, `ocamlbuild` (available with, e.g., `dnf install ocaml`)
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- Linux tools (e.g. `ar`); currently it is easiest to build the static
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libraries in a single environment but this could be fixed in the future (TODO)
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Remember to retrieve the Wasm spec submodule:
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```
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git clone ... --recursive
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```
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### Build
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```
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RUSTFLAGS=--cfg=fuzzing cargo build
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```
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Use `FFI_LIB_DIR=path/to/lib/...` to specify a different location for the static
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library (this is mainly for debugging). If the `--cfg=fuzzing` configuration is
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not provided, this crate will build successfully but fail at runtime.
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### Test
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```
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RUSTFLAGS=--cfg=fuzzing cargo test
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```
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