--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.jvmci.options/src/com/oracle/jvmci/options/DerivedOptionValue.java	Tue May 26 23:21:15 2015 +0200
@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 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.
+ *
+ * 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 com.oracle.jvmci.options;
+
+import java.io.*;
+import java.util.function.*;
+
+import com.oracle.jvmci.options.OptionValue.OverrideScope;
+
+/**
+ * A cached value that needs to be recomputed when an option changes.
+ */
+public class DerivedOptionValue<T> {
+
+    public interface OptionSupplier<T> extends Supplier<T>, Serializable {
+    }
+
+    private final T initialValue;
+    private final OptionSupplier<T> supplier;
+
+    public DerivedOptionValue(OptionSupplier<T> supplier) {
+        this.supplier = supplier;
+        assert OptionValue.getOverrideScope() == null : "derived option value should be initialized outside any override scope";
+        this.initialValue = createValue();
+    }
+
+    public T getValue() {
+        OverrideScope overrideScope = OptionValue.getOverrideScope();
+        if (overrideScope != null) {
+            return overrideScope.getDerived(this);
+        } else {
+            return initialValue;
+        }
+    }
+
+    T createValue() {
+        return supplier.get();
+    }
+}