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diff --git a/Source/JavaScriptCore/dfg/DFGOSRExitPreparation.h b/Source/JavaScriptCore/dfg/DFGOSRExitPreparation.h
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+/*
+ * Copyright (C) 2013 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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 with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#ifndef DFGOSRExitPreparation_h
+#define DFGOSRExitPreparation_h
+
+#if ENABLE(DFG_JIT)
+
+#include "CallFrame.h"
+#include "CodeOrigin.h"
+
+namespace JSC { namespace DFG {
+
+// Make sure all code on our inline stack is JIT compiled. This is necessary since
+// we may opt to inline a code block even before it had ever been compiled by the
+// JIT, but our OSR exit infrastructure currently only works if the target of the
+// OSR exit is JIT code. This could be changed since there is nothing particularly
+// hard about doing an OSR exit into the interpreter, but for now this seems to make
+// sense in that if we're OSR exiting from inlined code of a DFG code block, then
+// probably it's a good sign that the thing we're exiting into is hot. Even more
+// interestingly, since the code was inlined, it may never otherwise get JIT
+// compiled since the act of inlining it may ensure that it otherwise never runs.
+void prepareCodeOriginForOSRExit(ExecState*, CodeOrigin);
+
+} } // namespace JSC::DFG
+
+#endif // ENABLE(DFG_JIT)
+
+#endif // DFGOSRExitPreparation_h
+
+