[builtins] implement JSBuiltinReducer for ArrayIteratorNext()

src/isolate.cc

 // 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.
 
 #include "src/isolate.h"
 
 #include <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
@@ skipping 2933 matching lines @@
 
 void Isolate::InvalidateStringLengthOverflowProtector() {
   DCHECK(factory()->string_length_protector()->value()->IsSmi());
   DCHECK(IsStringLengthOverflowIntact());
   PropertyCell::SetValueWithInvalidation(
       factory()->string_length_protector(),
       handle(Smi::FromInt(kArrayProtectorInvalid), this));
   DCHECK(!IsStringLengthOverflowIntact());
 }
 
+void Isolate::InvalidateArrayIteratorProtector() {

[Camillo Bruni, 2016/11/09 12:03:49]

You may want to wire this to LookupIterator::InternalUpdateProtector

[caitp, 2016/11/09 17:40:16]

this cell isn't changed during lookup, it's changed if a fast array map used by
the array iterator transitions to a slow one --- the iterator implementations
handle it manually. I think it's okay to not wire it up to anything

+  DCHECK(factory()->array_iterator_protector()->value()->IsSmi());
+  DCHECK(CanInlineArrayIterator());
+  factory()->array_iterator_protector()->set_value(
+      Smi::FromInt(kArrayProtectorInvalid));
+  DCHECK(!CanInlineArrayIterator());
+}
+
 bool Isolate::IsAnyInitialArrayPrototype(Handle<JSArray> array) {
   DisallowHeapAllocation no_gc;
   return IsInAnyContext(*array, Context::INITIAL_ARRAY_PROTOTYPE_INDEX);
 }
 
 
 CallInterfaceDescriptorData* Isolate::call_descriptor_data(int index) {
   DCHECK(0 <= index && index < CallDescriptors::NUMBER_OF_DESCRIPTORS);
   return &call_descriptor_data_[index];
 }
@@ skipping 523 matching lines @@
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8