Support private values in GN.

tools/gn/parse_tree.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "tools/gn/parse_tree.h"
 
 #include <string>
 
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 199 matching lines @@
 }
 
 Value BlockNode::Execute(Scope* containing_scope, Err* err) const {
   if (has_scope_) {
     Scope our_scope(containing_scope);
     Value ret = ExecuteBlockInScope(&our_scope, err);
     if (err->has_error())
       return Value();
 
     // Check for unused vars in the scope.
-    //our_scope.CheckForUnusedVars(err);
+    our_scope.CheckForUnusedVars(err);
     return ret;
   }
   return ExecuteBlockInScope(containing_scope, err);
 }
 
 LocationRange BlockNode::GetRange() const {
   if (begin_token_.type() != Token::INVALID &&
       end_token_.type() != Token::INVALID) {
     return begin_token_.range().Union(end_token_.range());
   } else if (!statements_.empty()) {
@@ skipping 289 matching lines @@
 
 Err UnaryOpNode::MakeErrorDescribing(const std::string& msg,
                                      const std::string& help) const {
   return Err(op_, msg, help);
 }
 
 void UnaryOpNode::Print(std::ostream& out, int indent) const {
   out << IndentFor(indent) << "UNARY(" << op_.value() << ")\n";
   operand_->Print(out, indent + 1);
 }