wasmer/tests/compilers/functions.rs

use test_utils::wasmer_compilers;

wasmer_compilers! {
    use wasmer::*;
    #[test]
    fn native_function_works_for_wasm() {
        let store = get_store();
        let wat = r#"(module
        (func $multiply (import "env" "multiply") (param i32 i32) (result i32))
        (func (export "add") (param i32 i32) (result i32)
           (i32.add (local.get 0)
                    (local.get 1)))
        (func (export "double_then_add") (param i32 i32) (result i32)
           (i32.add (call $multiply (local.get 0) (i32.const 2))
                    (call $multiply (local.get 1) (i32.const 2))))
)"#;
        let module = Module::new(&store, wat).unwrap();

        let import_object = imports! {
            "env" => {
                "multiply" => Function::new(&store, |a: i32, b: i32| a * b),
            },
        };

        let instance = Instance::new(&module, &import_object).unwrap();

        let f: NativeFunc<(i32, i32), i32> = instance.exports.get("add").unwrap();
        let result = f.call(4, 6).unwrap();
        assert_eq!(result, 10);

        let dyn_f: Function = instance.exports.get("double_then_add").unwrap();
        let dyn_result = dyn_f.call(&[Val::I32(4), Val::I32(6)]).unwrap();
        assert_eq!(dyn_result[0], Val::I32(20));

        let f: NativeFunc<(i32, i32), i32> = dyn_f.native().unwrap();

        let result = f.call(4, 6).unwrap();
        assert_eq!(result, 20);
    }
}