The expected expression stack height at the return label can be...

src/codegen-arm.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 321 matching lines @@
   // permits optimization and calls GenerateFastCaseSwitch if it does.
   // Returns true if the fast-case switch was generated, and false if not.
   bool TryGenerateFastCaseSwitchStatement(SwitchStatement* node);
 
 
   // Bottle-neck interface to call the Assembler to generate the statement
   // position. This allows us to easily control whether statement positions
   // should be generated or not.
   void RecordStatementPosition(Node* node);
 
+  // Is the given jump target the actual (ie, non-shadowed) function return
+  // target?
+  bool IsActualFunctionReturn(JumpTarget* target);
+
   bool is_eval_;  // Tells whether code is generated for eval.
   Handle<Script> script_;
   List<DeferredCode*> deferred_;
 
   // Assembler
   MacroAssembler* masm_;  // to generate code
 
   // Code generation state
   Scope* scope_;
   VirtualFrame* frame_;
   Condition cc_reg_;
   CodeGenState* state_;
   bool is_inside_try_;
   int break_stack_height_;
 
   // Jump targets
   JumpTarget function_return_;
 
+  // True if the function return is shadowed (ie, jumping to the target
+  // function_return_ does not jump to the true function return, but rather
+  // to some unlinking code).
+  bool function_return_is_shadowed_;
+
   friend class VirtualFrame;
+  friend class JumpTarget;
   friend class Reference;
 
   DISALLOW_COPY_AND_ASSIGN(CodeGenerator);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODEGEN_ARM_H_