Add LookupIterator constructor for arbitrary Object keys

src/lookup.cc

 // Copyright 2014 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/lookup.h"
 
 #include "src/bootstrapper.h"
 #include "src/deoptimizer.h"
 #include "src/isolate-inl.h"
 #include "src/lookup-inl.h"
 
 namespace v8 {
 namespace internal {
 
 
+// static
+LookupIterator LookupIterator::PropertyOrElement(Isolate* isolate,
+                                                 Handle<Object> receiver,
+                                                 Handle<Object> key,
+                                                 bool* success,
+                                                 Configuration configuration) {
+  uint32_t index = 0;
+  if (key->ToArrayIndex(&index)) {
+    *success = true;
+    return LookupIterator(isolate, receiver, index, configuration);
+  }
+
+  Handle<Name> name;
+  *success = Object::ToName(isolate, key).ToHandle(&name);
+  if (!*success) {
+    DCHECK(isolate->has_pending_exception());
+    // Return an unusable dummy.
+    return LookupIterator(receiver, isolate->factory()->empty_string());
+  }
+
+  if (name->AsArrayIndex(&index)) {
+    LookupIterator it(isolate, receiver, index, configuration);
+    // Here we try to avoid having to rebuild the string later
+    // by storing it on the indexed LookupIterator.
+    it.name_ = name;
+    return it;
+  }
+
+  return LookupIterator(receiver, name, configuration);
+}
+
+
 void LookupIterator::Next() {
   DCHECK_NE(JSPROXY, state_);
   DCHECK_NE(TRANSITION, state_);
   DisallowHeapAllocation no_gc;
   has_property_ = false;
 
   JSReceiver* holder = *holder_;
   Map* map = *holder_map_;
 
   // Perform lookup on current holder.
@@ skipping 530 matching lines @@
       case InterceptorState::kSkipNonMasking:
         return true;
       case InterceptorState::kProcessNonMasking:
         return false;
     }
   }
   return interceptor_state_ == InterceptorState::kProcessNonMasking;
 }
 }  // namespace internal
 }  // namespace v8