Strict mode parameter validation.

src/scopes.h

 // Copyright 2010 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 271 matching lines @@
   // Determine if we can use lazy compilation for this scope.
   bool AllowsLazyCompilation() const;
 
   // True if the outer context of this scope is always the global context.
   virtual bool HasTrivialOuterContext() const;
 
   // The number of contexts between this and scope; zero if this == scope.
   int ContextChainLength(Scope* scope);
 
   // ---------------------------------------------------------------------------
+  // Strict mode support.
+  bool IsDeclared(Handle<String> name) {
+    // During formal parameter list parsing the scope only contains
+    // two variables inserted at initialization: "this" and "arguments".
+    // "this" is an invalid parameter name and "arguments" is invalid parameter
+    // name in strict mode. Therefore looking up with the map which includes
+    // "this" and "arguments" in addition to all formal parameters is safe.
+    return variables_.Lookup(name) != NULL;
+  }
+
+  // ---------------------------------------------------------------------------
   // Debugging.
 
 #ifdef DEBUG
   void Print(int n = 0);  // n = indentation; n < 0 => don't print recursively
 #endif
 
   // ---------------------------------------------------------------------------
   // Implementation.
  protected:
   friend class ParserFactory;
@@ skipping 172 matching lines @@
   int nesting_level_;
   // Nesting level of outermost scope that is contained in a with statement,
   // or kNotInsideWith if there are no with's around the current scope.
   int inside_with_level_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_SCOPES_H_