Make closures optimizable by Crankshaft compiler.

src/variables.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 120 matching lines @@
   // in an outer scope about which we don't know anything (it may not
   // be the global scope). scope() is NULL in that case. Currently the
   // scope is only used to follow the context chain length.
   Scope* scope() const { return scope_; }
 
   Handle<String> name() const { return name_; }
   Mode mode() const { return mode_; }
   bool is_accessed_from_inner_scope() const {
     return is_accessed_from_inner_scope_;
   }
+  void MarkAsAccessedFromInnerScope() {
+    is_accessed_from_inner_scope_ = true;
+  }
   bool is_used() { return is_used_; }
   void set_is_used(bool flag) { is_used_ = flag; }
 
   bool IsVariable(Handle<String> n) const {
     return !is_this() && name().is_identical_to(n);
   }
 
   bool IsStackAllocated() const;
   bool IsParameter() const;  // Includes 'this'.
   bool IsStackLocal() const;
+  bool IsContextSlot() const;
 
   bool is_dynamic() const {
     return (mode_ == DYNAMIC ||
             mode_ == DYNAMIC_GLOBAL ||
             mode_ == DYNAMIC_LOCAL);
   }
 
   bool is_global() const;
   bool is_this() const { return kind_ == THIS; }
   bool is_arguments() const { return kind_ == ARGUMENTS; }
 
   // True if the variable is named eval and not known to be shadowed.
   bool is_possibly_eval() const {
     return IsVariable(Factory::eval_symbol()) &&
         (mode_ == DYNAMIC || mode_ == DYNAMIC_GLOBAL);
   }
 
   Variable* local_if_not_shadowed() const {
     ASSERT(mode_ == DYNAMIC_LOCAL && local_if_not_shadowed_ != NULL);
     return local_if_not_shadowed_;
   }
 
   void set_local_if_not_shadowed(Variable* local) {
     local_if_not_shadowed_ = local;
   }
 
   Expression* rewrite() const { return rewrite_; }
+  void set_rewrite(Expression* expr) { rewrite_ = expr; }
 
   StaticType* type() { return &type_; }
 
  private:
   Scope* scope_;
   Handle<String> name_;
   Mode mode_;
   bool is_valid_LHS_;
   Kind kind_;
 
   Variable* local_if_not_shadowed_;
 
   // Usage info.
   bool is_accessed_from_inner_scope_;  // set by variable resolver
   bool is_used_;
 
   // Static type information
   StaticType type_;
 
   // Code generation.
   // rewrite_ is usually a Slot or a Property, but may be any expression.
   Expression* rewrite_;
-
-  friend class Scope;  // Has explicit access to rewrite_.
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_VARIABLES_H_