Detect conflicting variable bindings in harmony mode.

src/parser.h

 // Copyright 2011 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
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 //     * Redistributions in binary form must reproduce the above
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 //       disclaimer in the documentation and/or other materials provided
@@ skipping 627 matching lines @@
                                                bool* ok);
 
   // Strict mode validation of LValue expressions
   void CheckStrictModeLValue(Expression* expression,
                              const char* error,
                              bool* ok);
 
   // Strict mode octal literal validation.
   void CheckOctalLiteral(int beg_pos, int end_pos, bool* ok);
 
+  // For harmony block scoping mode: Check if the scope has conflicting var
+  // declarations, i.e. a var declaration that has been hoisted from a nested
+  // scope over a let binding of the same name.

[Lasse Reichstein, 2011/09/01 07:34:04]

Be more explicit (define what you mean by "over", or, prefereably, don't say
anything about hoisting - just say what the invalid syntax structure is).
Am I understanding it correctly if the invalid case is:
A var declaration inside a nested scope/block of a scope with a
let(/const/function)-declaration of the same name. I.e., it doesn't check for
redeclaration in the same scope (that's handled inline)?

[Steven, 2011/09/01 15:01:33]

Done.

+  void CheckConflictingVarDeclarations(Scope* scope, bool* ok);
+
   // Parser support
   VariableProxy* Declare(Handle<String> name, Variable::Mode mode,
                          FunctionLiteral* fun,
                          bool resolve,
                          bool* ok);
 
   bool TargetStackContainsLabel(Handle<String> label);
   BreakableStatement* LookupBreakTarget(Handle<String> label, bool* ok);
   IterationStatement* LookupContinueTarget(Handle<String> label, bool* ok);
 
@@ skipping 100 matching lines @@
  private:
   static const int kTypeSlot = 0;
   static const int kElementsSlot = 1;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(CompileTimeValue);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_PARSER_H_