V8 support for cached accessors.

src/objects.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <memory>
 #include <sstream>
@@ skipping 1344 matching lines @@
     Handle<Object> reboxed_result = handle(*result, isolate);
     if (info->replace_on_access() && receiver->IsJSReceiver()) {
       args.Call(reinterpret_cast<GenericNamedPropertySetterCallback>(
                     &Accessors::ReconfigureToDataProperty),
                 name, result);
       RETURN_EXCEPTION_IF_SCHEDULED_EXCEPTION(isolate, Object);
     }
     return reboxed_result;
   }
 
+  // AccessorPair with 'cached' private property.
+  if (it->TryLookupCachedProperty()) {
+    return Object::GetProperty(it);
+  }
+
   // Regular accessor.
   Handle<Object> getter(AccessorPair::cast(*structure)->getter(), isolate);
   if (getter->IsFunctionTemplateInfo()) {
     return Builtins::InvokeApiFunction(
         isolate, false, Handle<FunctionTemplateInfo>::cast(getter), receiver, 0,
         nullptr, isolate->factory()->undefined_value());
   } else if (getter->IsCallable()) {
     // TODO(rossberg): nicer would be to cast to some JSCallable here...
     return Object::GetPropertyWithDefinedGetter(
         receiver, Handle<JSReceiver>::cast(getter));
@@ skipping 18887 matching lines @@
   for (const auto& name : names) {
     JSObject::SetAccessor(
         ns, Accessors::ModuleNamespaceEntryInfo(isolate, name, attr))
         .Check();
   }
   JSObject::PreventExtensions(ns, THROW_ON_ERROR).ToChecked();
 
   return ns;
 }
 
+MaybeHandle<Name> FunctionTemplateInfo::TryGetCachedPropertyName(
+    Isolate* isolate, Handle<Object> getter) {
+  if (getter->IsFunctionTemplateInfo()) {
+    Handle<FunctionTemplateInfo> fti =
+        Handle<FunctionTemplateInfo>::cast(getter);
+    // Check if the accessor uses a cached property.
+    if (!fti->cached_property_name()->IsTheHole(isolate)) {
+      return handle(Name::cast(fti->cached_property_name()));
+    }
+  }
+  return MaybeHandle<Name>();
+}
+
 }  // namespace internal
 }  // namespace v8