More cleanup related to setting array.length

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 5e03e8abde4910923800e099cd6e921881ae921f..516c68dfb42b6d7a84b68fe1942b65b788286572 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -11930,28 +11930,22 @@ static bool GetOldValue(Isolate* isolate,
   return true;
 }
 
-MaybeHandle<Object> JSArray::SetElementsLength(
-    Handle<JSArray> array,
-    Handle<Object> new_length_handle) {
-  if (array->HasFastElements() &&
-      SetElementsLengthWouldNormalize(array->GetHeap(), new_length_handle)) {
-    NormalizeElements(array);
-  }
 
+void JSArray::SetLength(Handle<JSArray> array, uint32_t new_length) {
   // We should never end in here with a pixel or external array.
-  DCHECK(array->AllowsSetElementsLength());
-  if (!array->map()->is_observed()) {
-    return array->GetElementsAccessor()->SetLength(array, new_length_handle);
-  }
+  DCHECK(array->AllowsSetLength());
+  array->GetElementsAccessor()->SetLength(array, new_length);
+}
+
 
+MaybeHandle<Object> JSArray::ObserveableSetLength(Handle<JSArray> array,

[Jakob Kummerow, 2015/06/19 13:23:12]

nit: "observable" (one less 'e') is the far more common spelling.

+                                                  uint32_t new_length) {
   Isolate* isolate = array->GetIsolate();
   List<uint32_t> indices;
   List<Handle<Object> > old_values;
   Handle<Object> old_length_handle(array->length(), isolate);
   uint32_t old_length = 0;
   CHECK(old_length_handle->ToArrayLength(&old_length));
-  uint32_t new_length = 0;
-  CHECK(new_length_handle->ToArrayLength(&new_length));
 
   static const PropertyAttributes kNoAttrFilter = NONE;
   int num_elements = array->NumberOfOwnElements(kNoAttrFilter);
@@ -11975,14 +11969,10 @@ MaybeHandle<Object> JSArray::SetElementsLength(
     }
   }
 
-  Handle<Object> hresult;
-  ASSIGN_RETURN_ON_EXCEPTION(
-      isolate, hresult,
-      array->GetElementsAccessor()->SetLength(array, new_length_handle),
-      Object);
+  SetLength(array, new_length);
 
   CHECK(array->length()->ToArrayLength(&new_length));
-  if (old_length == new_length) return hresult;
+  if (old_length == new_length) return array;
 
   RETURN_ON_EXCEPTION(isolate, BeginPerformSplice(array), Object);
 
@@ -11997,6 +11987,7 @@ MaybeHandle<Object> JSArray::SetElementsLength(
             old_values[i]),
         Object);
   }
+
   RETURN_ON_EXCEPTION(isolate,
                       JSObject::EnqueueChangeRecord(
                           array, "update", isolate->factory()->length_string(),
@@ -12018,15 +12009,13 @@ MaybeHandle<Object> JSArray::SetElementsLength(
           .Assert();
     }
 
-    ElementsAccessor* accessor = deleted->GetElementsAccessor();
-    accessor->SetLength(deleted, isolate->factory()->NewNumberFromUint(
-                                     delete_count)).Check();
+    JSArray::SetLength(deleted, delete_count);
   }
 
   RETURN_ON_EXCEPTION(
       isolate, EnqueueSpliceRecord(array, index, deleted, add_count), Object);
 
-  return hresult;
+  return array;
 }