Strawman: check strong mode free variables against the global object.

src/pending-compilation-error-handler.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_PENDING_COMPILATION_ERROR_HANDLER_H_
 #define V8_PENDING_COMPILATION_ERROR_HANDLER_H_
 
 #include "src/base/macros.h"
 #include "src/globals.h"
+#include "src/handles.h"
 
 namespace v8 {
 namespace internal {
 
 class AstRawString;
-template <class T>
-class Handle;
 class Isolate;
 class Script;
 
 // Helper class for handling pending compilation errors consistently in various
 // compilation phases.
 class PendingCompilationErrorHandler {
  public:
   PendingCompilationErrorHandler()
       : has_pending_error_(false),
         start_position_(-1),
@@ skipping 22 matching lines @@
     if (has_pending_error_) return;
     has_pending_error_ = true;
     start_position_ = start_position;
     end_position_ = end_position;
     message_ = message;
     char_arg_ = nullptr;
     arg_ = arg;
     error_type_ = error_type;
   }
 
+  void ReportMessageAt(int start_position, int end_position,
+                       const char* message, Handle<String> arg,
+                       ParseErrorType error_type = kSyntaxError) {
+    if (has_pending_error_) return;
+    has_pending_error_ = true;
+    start_position_ = start_position;
+    end_position_ = end_position;
+    message_ = message;
+    char_arg_ = nullptr;
+    arg_ = nullptr;
+    handle_arg_ = arg;
+    error_type_ = error_type;
+  }
+
   bool has_pending_error() const { return has_pending_error_; }
 
   void ThrowPendingError(Isolate* isolate, Handle<Script> script);
 
  private:
   bool has_pending_error_;
   int start_position_;
   int end_position_;
   const char* message_;
   const AstRawString* arg_;
   const char* char_arg_;
+  Handle<String> handle_arg_;
   ParseErrorType error_type_;
 
   DISALLOW_COPY_AND_ASSIGN(PendingCompilationErrorHandler);
 };
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_PENDING_COMPILATION_ERROR_HANDLER_H_