//! Compile arbitrary bytes from the fuzzer as if they were Wasm. Also use

//! `wasm-mutate` to mutate the fuzz inputs.

#![no_main]

use libfuzzer_sys::{fuzz_mutator, fuzz_target};

use wasmtime::{Config, Engine, Module};

fn create_engine() -> Engine {

    let mut config = Config::default();

    // Safety: the Cranelift option `regalloc_checker` does not alter

    // the generated code at all; it only does extra checking after

    // compilation.

    unsafe {

        config.cranelift_flag_enable("regalloc_checker");

    }

    Engine::new(&config).expect("Could not construct Engine")

}

fuzz_target!(|data: &[u8]| {

    let engine = create_engine();

    wasmtime_fuzzing::oracles::log_wasm(data);

    drop(Module::new(&engine, data));

});

fuzz_mutator!(|data: &mut [u8], size: usize, max_size: usize, seed: u32| {

    // Half of the time use libfuzzer's built in mutators, and the other half of

    // the time use `wasm-mutate`.

    if seed.count_ones() % 2 == 0 {

        libfuzzer_sys::fuzzer_mutate(data, size, max_size)

    } else {

        wasmtime_fuzzing::mutators::wasm_mutate(

            data,

            size,

            max_size,

            seed,

            libfuzzer_sys::fuzzer_mutate,

        )

    }

});