[proxies] Make Array.isArray respect proxies.

src/objects-inl.h

 // Copyright 2012 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.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 161 matching lines @@
   return Object::IsHeapObject() &&
          HeapObject::cast(this)->map()->instance_type() <= LAST_NAME_TYPE;
 }
 
 
 bool Object::IsUniqueName() const {
   return IsInternalizedString() || IsSymbol();
 }
 
 
+Maybe<bool> Object::IsArray() const {

[Benedikt Meurer, 2015/12/03 10:38:53]

Mhm, given that this can throw, we probably should handlify this guy. I.e. turn
it into static Maybe<bool> Object::IsArray(Handle<Object> arg).

[jochen (gone - plz use gerrit), 2015/12/03 10:40:53]

there needs to be a way to figure out whether something is an array without
throwing exceptions :-/

+  if (this->IsJSArray()) return Just(true);
+  if (this->IsJSProxy()) {
+    const JSProxy* proxy = JSProxy::cast(this);
+    if (proxy->IsRevoked()) {
+      Isolate* isolate = proxy->GetIsolate();
+      isolate->Throw(*isolate->factory()->NewTypeError(
+          MessageTemplate::kProxyRevoked,
+          isolate->factory()->NewStringFromAsciiChecked("IsArray")));
+      return Nothing<bool>();
+    }
+    return proxy->target()->IsArray();
+  }
+  return Just(false);
+}
+
+
 bool Object::IsCallable() const {
   return Object::IsHeapObject() && HeapObject::cast(this)->map()->is_callable();
 }
 
 
 bool Object::IsConstructor() const {
   return Object::IsHeapObject() &&
          HeapObject::cast(this)->map()->is_constructor();
 }
 
@@ skipping 7657 matching lines @@
 #undef WRITE_INT64_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_OBJECTS_INL_H_