# Fuzzing

This document describes how to fuzz cretonne with [`cargo-fuzz`](https://github.com/rust-fuzz/cargo-fuzz). The fuzz targets use `wasm-opt` from [`binaryen-rs`](https://github.com/pepyakin/binaryen-rs) to generate valid WebAssembly modules from the fuzzed input supplied by `cargo-fuzz` (via [libfuzzer](http://llvm.org/docs/LibFuzzer.html)). In this scheme coverage feedback from both cretonne and the `wasm-opt` input generation code is used to inform the fuzzer.

# Usage

1. Install all dependencies required to build `binaryen-rs` and `cargo-fuzz` (including `cmake`)
2. Use the rust nightly toolchain (required by `cargo-fuzz`): `rustup override set nightly`
3. Execute the fuzz target: `cargo fuzz run fuzz_translate_module`