Reporting -1 as the size of an ILLEGAL reference which actually has...

src/codegen-ia32.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 103 matching lines @@
   Reference(CodeGenerator* cgen, Expression* expression);
   ~Reference();
 
   Expression* expression() const { return expression_; }
   Type type() const { return type_; }
   void set_type(Type value) {
     ASSERT(type_ == ILLEGAL);
     type_ = value;
   }
 
-  // The size of the reference or -1 if the reference is illegal.
-  int size() const { return type_; }
+  // The size the reference takes up on the stack.
+  int size() const { return (type_ == ILLEGAL) ? 0 : type_; }
 
   bool is_illegal() const { return type_ == ILLEGAL; }
   bool is_slot() const { return type_ == SLOT; }
   bool is_property() const { return type_ == NAMED || type_ == KEYED; }
 
   // Return the name.  Only valid for named property references.
   Handle<String> GetName();
 
   // Generate code to push the value of the reference on top of the
   // expression stack.  The reference is expected to be already on top of
@@ skipping 291 matching lines @@
   friend class VirtualFrame;
   friend class Reference;
 
   DISALLOW_COPY_AND_ASSIGN(CodeGenerator);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODEGEN_IA32_H_