Use LookupIterator for elements in the observed part of DefineAccessor

src/objects.cc

 // Copyright 2013 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 <iomanip>
 #include <sstream>
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
@@ skipping 6384 matching lines @@
   if (name->IsString()) name = String::Flatten(Handle<String>::cast(name));
 
   uint32_t index = 0;
   bool is_element = name->AsArrayIndex(&index);
 
   Handle<Object> old_value = isolate->factory()->the_hole_value();
   bool is_observed = object->map()->is_observed() &&
                      !isolate->IsInternallyUsedPropertyName(name);
   bool preexists = false;
   if (is_observed) {
-    if (is_element) {
-      Maybe<bool> maybe = HasOwnElement(object, index);
-      // Workaround for a GCC 4.4.3 bug which leads to "‘preexists’ may be used
-      // uninitialized in this function".
-      if (!maybe.IsJust()) {
-        DCHECK(false);
-        return isolate->factory()->undefined_value();
-      }
-      preexists = maybe.FromJust();
-      if (preexists && GetOwnElementAccessorPair(object, index).is_null()) {
-        old_value =
-            Object::GetElement(isolate, object, index).ToHandleChecked();
-      }
-    } else {
-      LookupIterator it(object, name, LookupIterator::HIDDEN_SKIP_INTERCEPTOR);
-      CHECK(GetPropertyAttributes(&it).IsJust());
-      preexists = it.IsFound();
-      if (preexists && (it.state() == LookupIterator::DATA ||
-                        it.GetAccessors()->IsAccessorInfo())) {
-        old_value = GetProperty(&it).ToHandleChecked();
-      }
+    LookupIterator::Configuration c = LookupIterator::HIDDEN_SKIP_INTERCEPTOR;
+    LookupIterator it = is_element ? LookupIterator(isolate, object, index, c)
+                                   : LookupIterator(object, name, c);
+    CHECK(GetPropertyAttributes(&it).IsJust());

[Jakob Kummerow, 2015/06/11 11:14:28]

I'm not a fan of having a Release-mode CHECK here, but since it's old code, I
guess we can keep it.

+    preexists = it.IsFound();
+    if (preexists && (it.state() == LookupIterator::DATA ||
+                      it.GetAccessors()->IsAccessorInfo())) {
+      old_value = GetProperty(&it).ToHandleChecked();
     }
   }
 
   if (is_element) {
     DefineElementAccessor(object, index, getter, setter, attributes);
   } else {
     DCHECK(getter->IsSpecFunction() || getter->IsUndefined() ||
            getter->IsNull());
     DCHECK(setter->IsSpecFunction() || setter->IsUndefined() ||
            setter->IsNull());
@@ skipping 10240 matching lines @@
                                             Handle<Object> new_value) {
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 }  // namespace internal
 }  // namespace v8