Don't use WrapperDescriptor and instead use Wrap/Unwrap APIs (#187)

src/env-inl.h

@@ -65,26 +65,8 @@ inline uv_loop_t* IsolateData::event_loop() const {
 inline void IsolateData::SetCppgcReference(v8::Isolate* isolate,
  v8::Local<v8::Object> object,
  void* wrappable) {
- v8::CppHeap* heap = isolate->GetCppHeap();
- CHECK_NOT_NULL(heap);
- v8::WrapperDescriptor descriptor = heap->wrapper_descriptor();
- uint16_t required_size = std::max(descriptor.wrappable_instance_index,
- descriptor.wrappable_type_index);
- CHECK_GT(object->InternalFieldCount(), required_size);
-
- uint16_t* id_ptr = nullptr;
- {
- Mutex::ScopedLock lock(isolate_data_mutex_);
- auto it =
- wrapper_data_map_.find(descriptor.embedder_id_for_garbage_collected);
- CHECK_NE(it, wrapper_data_map_.end());
- id_ptr = &(it->second->cppgc_id);
- }
-
- object->SetAlignedPointerInInternalField(descriptor.wrappable_type_index,
- id_ptr);
- object->SetAlignedPointerInInternalField(descriptor.wrappable_instance_index,
- wrappable);
+ v8::Object::Wrap<v8::CppHeapPointerTag::kDefaultTag>(
+ isolate, object, wrappable);
 }
 
 inline uint16_t* IsolateData::embedder_id_for_cppgc() const {

src/env.cc

@@ -70,7 +70,6 @@ using v8::TryCatch;
 using v8::Uint32;
 using v8::Undefined;
 using v8::Value;
-using v8::WrapperDescriptor;
 using worker::Worker;
 
 int const ContextEmbedderTag::kNodeContextTag = 0x6e6f64;
@@ -542,30 +541,11 @@ IsolateData::IsolateData(Isolate* isolate,
 
  uint16_t cppgc_id = kDefaultCppGCEmebdderID;
  if (cpp_heap != nullptr) {
- // The general convention of the wrappable layout for cppgc in the
- // ecosystem is:
- // [ 0 ] -> embedder id
- // [ 1 ] -> wrappable instance
- // If the Isolate includes a CppHeap attached by another embedder,
- // And if they also use the field 0 for the ID, we DCHECK that
- // the layout matches our layout, and record the embedder ID for cppgc
- // to avoid accidentally enabling cppgc on non-cppgc-managed wrappers .
- v8::WrapperDescriptor descriptor = cpp_heap->wrapper_descriptor();
- if (descriptor.wrappable_type_index == BaseObject::kEmbedderType) {
- cppgc_id = descriptor.embedder_id_for_garbage_collected;
- DCHECK_EQ(descriptor.wrappable_instance_index, BaseObject::kSlot);
- }
- // If the CppHeap uses the slot we use to put non-cppgc-traced BaseObject
- // for embedder ID, V8 could accidentally enable cppgc on them. So
- // safe guard against this.
- DCHECK_NE(descriptor.wrappable_type_index, BaseObject::kSlot);
+ // All CppHeap's support only one way of wrapping objects.
  } else {
  cpp_heap_ = CppHeap::Create(
  platform,
- CppHeapCreateParams{
- {},
- WrapperDescriptor(
- BaseObject::kEmbedderType, BaseObject::kSlot, cppgc_id)});
+ CppHeapCreateParams{{}});
  isolate->AttachCppHeap(cpp_heap_.get());
  }
  // We do not care about overflow since we just want this to be different

test/addons/cppgc-object/binding.cc

@@ -25,11 +25,6 @@ class CppGCed : public cppgc::GarbageCollected<CppGCed> {
  v8::Local<v8::Context> context) {
  auto ft = v8::FunctionTemplate::New(context->GetIsolate(), New);
  auto ot = ft->InstanceTemplate();
- v8::WrapperDescriptor descriptor =
- context->GetIsolate()->GetCppHeap()->wrapper_descriptor();
- uint16_t required_size = std::max(descriptor.wrappable_instance_index,
- descriptor.wrappable_type_index);
- ot->SetInternalFieldCount(required_size + 1);
  return ft->GetFunction(context).ToLocalChecked();
  }
 

test/cctest/test_cppgc.cc

@@ -25,10 +25,8 @@ class CppGCed : public cppgc::GarbageCollected<CppGCed> {
  v8::Local<v8::Object> js_object = args.This();
  CppGCed* gc_object = cppgc::MakeGarbageCollected<CppGCed>(
  isolate->GetCppHeap()->GetAllocationHandle());
- js_object->SetAlignedPointerInInternalField(kWrappableTypeIndex,
- &kEmbedderID);
- js_object->SetAlignedPointerInInternalField(kWrappableInstanceIndex,
- gc_object);
+ v8::Object::Wrap<v8::CppHeapPointerTag::kDefaultTag>(
+ isolate, js_object, gc_object);
  kConstructCount++;
  args.GetReturnValue().Set(js_object);
  }
@@ -37,7 +35,6 @@ class CppGCed : public cppgc::GarbageCollected<CppGCed> {
  v8::Local<v8::Context> context) {
  auto ft = v8::FunctionTemplate::New(context->GetIsolate(), New);
  auto ot = ft->InstanceTemplate();
- ot->SetInternalFieldCount(2);
  return ft->GetFunction(context).ToLocalChecked();
  }
 
@@ -60,10 +57,7 @@ TEST_F(NodeZeroIsolateTestFixture, ExistingCppHeapTest) {
  // it recognizes the existing heap.
  std::unique_ptr<v8::CppHeap> cpp_heap = v8::CppHeap::Create(
  platform.get(),
- v8::CppHeapCreateParams(
- {},
- v8::WrapperDescriptor(
- kWrappableTypeIndex, kWrappableInstanceIndex, kEmbedderID)));
+ v8::CppHeapCreateParams({}));
  isolate->AttachCppHeap(cpp_heap.get());
 
  // Try creating Context + IsolateData + Environment.