Function call_linked_func

tests/all/call_hook.rs:173–235

()

// Use the Linker to define a sync func, call it through WebAssembly:
#[test]
fn call_linked_func() -> Result<(), Error> {
    let engine = Engine::default();
    let mut store = Store::new(&engine, State::default());
    store.call_hook(sync_call_hook);
    let mut linker = Linker::new(&engine);

    linker.func_wrap(
        "host",
        "f",
        |caller: Caller<State>, a: i32, b: i64, c: f32, d: f64| {
            // Calling this func will switch context into wasm, then back to host:
            assert_eq!(caller.data().context, vec![Context::Wasm, Context::Host]);

            assert_eq!(
                caller.data().calls_into_host,
                caller.data().returns_from_host + 1
            );
            assert_eq!(
                caller.data().calls_into_wasm,
                caller.data().returns_from_wasm + 1
            );

            assert_eq!(a, 1);
            assert_eq!(b, 2);
            assert_eq!(c, 3.0);
            assert_eq!(d, 4.0);
        },
    )?;

    let wat = r#"
        (module
            (import "host" "f"
                (func $f (param i32) (param i64) (param f32) (param f64)))
            (func (export "export")
                (call $f (i32.const 1) (i64.const 2) (f32.const 3.0) (f64.const 4.0)))
        )
    "#;
    let module = Module::new(&engine, wat)?;

    let inst = linker.instantiate(&mut store, &module)?;
    let export = inst
        .get_export(&mut store, "export")
        .expect("get export")
        .into_func()
        .expect("export is func");

    export.call(&mut store, &[], &mut [])?;

    // One switch from vm to host to call f, another in return from f.
    assert_eq!(store.data().calls_into_host, 1);
    assert_eq!(store.data().returns_from_host, 1);
    assert_eq!(store.data().calls_into_wasm, 1);
    assert_eq!(store.data().returns_from_wasm, 1);

    export.typed::<(), ()>(&store)?.call(&mut store, ())?;

    assert_eq!(store.data().calls_into_host, 2);
    assert_eq!(store.data().returns_from_host, 2);