cargo fuzz integration (#306)

* added wip translate_module fuzzer

* use local binaryen-rs fork (with shim) for fuzzing

* minor doc cleanup

* check fuzzer integration via CI

* switch back to upstream binaryen-rs; add forgotten integration test directive

cranelift/fuzz/Cargo.toml

@@ -0,0 +1,29 @@
+[package]
+name = "cton-wasm-fuzz"
+version = "0.0.1"
+authors = ["foote@fastly.com"]
+publish = false
+
+[package.metadata]
+cargo-fuzz = true
+
+[dependencies.cargo-fuzz]
+version = "*"
+
+[dependencies.binaryen]
+git = "https://github.com/pepyakin/binaryen-rs.git"
+version = "*"
+
+[dependencies.libfuzzer-sys]
+git = "https://github.com/rust-fuzz/libfuzzer-sys.git"
+
+[dependencies.cretonne-wasm]
+path = "../lib/wasm"
+
+# Prevent this from interfering with workspaces
+[workspace]
+members = ["."]
+
+[[bin]]
+name = "fuzz_translate_module"
+path = "fuzz_translate_module.rs"

cranelift/fuzz/fuzz_translate_module.rs

@@ -0,0 +1,15 @@
+#![no_main]
+#[macro_use]
+extern crate libfuzzer_sys;
+extern crate binaryen;
+extern crate cretonne_wasm;
+use cretonne_wasm::{translate_module, DummyEnvironment};
+
+fuzz_target!(|data: &[u8]| {
+    let binaryen_module = binaryen::tools::translate_to_fuzz_mvp(data);
+
+    let wasm = binaryen_module.write();
+
+    let mut dummy_environ = DummyEnvironment::default();
+    translate_module(&wasm, &mut dummy_environ).unwrap();
+});