feat(op2): support cppgc in async ops (denoland#673)

`#[cppgc]` return values were added in
denoland/deno_core@a736d86
which made
creation of cppgc backed objects possible without direct access to V8
APIs.

This patch builds on top of that and adds `#[cppgc]` support for async
ops.

Author: littledivy

ops/op2/dispatch_slow.rs

@@ -782,7 +782,7 @@ pub fn return_value_v8_value(
       quote!(deno_core::_ops::RustToV8Marker::<deno_core::_ops::NumberMarker, _>::from(#result))
     }
     ArgMarker::Cppgc => {
-      quote!(deno_core::cppgc::make_cppgc_object(&mut #scope, #result))
+      quote!(deno_core::cppgc::make_cppgc_object(#scope, #result))
     }
     ArgMarker::None => quote!(#result),
   };

ops/op2/test_cases/sync/cppgc_resource.out

@@ -12,3 +12,9 @@ struct Wrap;
 fn op_make_cppgc_object() -> Wrap {
     Wrap
 }
+
+#[op2(async)]
+#[cppgc]
+async fn op_make_cppgc_object_async() -> Wrap {
+    Wrap
+}

ops/op2/test_cases/sync/cppgc_resource.rs

@@ -52,6 +52,8 @@ deno_core::extension!(
     ops_async::op_async_barrier_create,
     ops_async::op_async_barrier_await,
     ops_async::op_async_spin_on_state,
+    ops_async::op_async_make_cppgc_resource,
+    ops_async::op_async_get_cppgc_resource,
     ops_error::op_async_throw_error_eager,
     ops_error::op_async_throw_error_lazy,
     ops_error::op_async_throw_error_deferred,

testing/checkin/runner/mod.rs

@@ -46,3 +46,21 @@ pub async fn op_async_spin_on_state(state: Rc<RefCell<OpState>>) {
   })
   .await
 }
+
+pub struct TestResource {
+  value: u32,
+}
+
+#[op2(async)]
+#[cppgc]
+pub async fn op_async_make_cppgc_resource() -> TestResource {
+  TestResource { value: 42 }
+}
+
+#[op2(async)]
+#[smi]
+pub async fn op_async_get_cppgc_resource(
+  #[cppgc] resource: &TestResource,
+) -> u32 {
+  resource.value
+}

testing/checkin/runner/ops_async.rs

@@ -1,7 +1,12 @@
 // Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
 import { assert, assertArrayEquals, assertEquals, test } from "checkin:testing";
 
-const { op_pipe_create, op_file_open } = Deno.core.ops;
+const {
+  op_pipe_create,
+  op_file_open,
+  op_async_make_cppgc_resource,
+  op_async_get_cppgc_resource,
+} = Deno.core.ops;
 
 test(async function testPipe() {
   const [p1, p2] = op_pipe_create();
@@ -52,3 +57,8 @@ test(async function testFileIsNotTerminal() {
   const file = await op_file_open("./README.md");
   assert(!Deno.core.isTerminal(file));
 });
+
+test(async function testCppgcAsync() {
+  const resource = await op_async_make_cppgc_resource();
+  assertEquals(await op_async_get_cppgc_resource(resource), 42);
+});