Internalize strings being stored into uninitialized property cells

src/objects.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.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 9640 matching lines @@
   void set_type(HeapType* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
 
   // [dependent_code]: dependent code that depends on the type of the global
   // property.
   DECL_ACCESSORS(dependent_code, DependentCode)
 
   // Sets the value of the cell and updates the type field to be the union
   // of the cell's current type and the value's type. If the change causes
   // a change of the type of the cell's contents, code dependent on the cell
   // will be deoptimized.
-  static void SetValueInferType(Handle<PropertyCell> cell,
-                                Handle<Object> value);
+  // Usually returns the value that was passed in, but may perform
+  // non-observable modifications on it, such as internalize strings.
+  static Handle<Object> SetValueInferType(Handle<PropertyCell> cell,
+                                          Handle<Object> value);
 
   // Computes the new type of the cell's contents for the given value, but
   // without actually modifying the 'type' field.
   static Handle<HeapType> UpdatedType(Handle<PropertyCell> cell,
                                       Handle<Object> value);
 
   static void AddDependentCompilationInfo(Handle<PropertyCell> cell,
                                           CompilationInfo* info);
 
   DECLARE_CAST(PropertyCell)
@@ skipping 1367 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_