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diff --git a/src/jdk/nashorn/internal/codegen/AstSerializer.java b/src/jdk/nashorn/internal/codegen/AstSerializer.java
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+/*
+ * Copyright (c) 2010, 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package jdk.nashorn.internal.codegen;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.ObjectOutputStream;
+import java.util.Collections;
+import java.util.zip.Deflater;
+import java.util.zip.DeflaterOutputStream;
+import jdk.nashorn.internal.ir.Block;
+import jdk.nashorn.internal.ir.FunctionNode;
+import jdk.nashorn.internal.ir.LexicalContext;
+import jdk.nashorn.internal.ir.Node;
+import jdk.nashorn.internal.ir.Statement;
+import jdk.nashorn.internal.ir.visitor.NodeVisitor;
+import jdk.nashorn.internal.runtime.options.Options;
+
+/**
+ * This static utility class performs serialization of FunctionNode ASTs to a byte array.
+ * The format is a standard Java serialization stream, deflated.
+ */
+final class AstSerializer {
+    // Experimentally, we concluded that compression level 4 gives a good tradeoff between serialization speed
+    // and size.
+    private static final int COMPRESSION_LEVEL = Options.getIntProperty("nashorn.serialize.compression", 4);
+    static byte[] serialize(final FunctionNode fn) {
+        final ByteArrayOutputStream out = new ByteArrayOutputStream();
+        final Deflater deflater = new Deflater(COMPRESSION_LEVEL);
+        try (final ObjectOutputStream oout = new ObjectOutputStream(new DeflaterOutputStream(out, deflater))) {
+            oout.writeObject(removeInnerFunctionBodies(fn));
+        } catch (final IOException e) {
+            throw new AssertionError("Unexpected exception serializing function", e);
+        } finally {
+            deflater.end();
+        }
+        return out.toByteArray();
+    }
+
+    private static FunctionNode removeInnerFunctionBodies(final FunctionNode fn) {
+        return (FunctionNode)fn.accept(new NodeVisitor<LexicalContext>(new LexicalContext()) {
+            @Override
+            public Node leaveBlock(final Block block) {
+                if (lc.isFunctionBody() && lc.getFunction(block) != lc.getOutermostFunction()) {
+                    return block.setStatements(lc, Collections.<Statement>emptyList());
+                }
+                return super.leaveBlock(block);
+            }
+        });
+    }
+}