--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api.dsl.test/src/com/oracle/truffle/api/dsl/test/UnsupportedSpecializationTest.java	Wed Jan 29 21:26:26 2014 +0100
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2012, 2013, 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.truffle.api.dsl.test;
+
+import org.junit.*;
+
+import com.oracle.truffle.api.dsl.*;
+import com.oracle.truffle.api.dsl.test.TypeSystemTest.TestRootNode;
+import com.oracle.truffle.api.dsl.test.TypeSystemTest.ValueNode;
+import com.oracle.truffle.api.dsl.test.UnsupportedSpecializationTestFactory.Undefined1Factory;
+
+public class UnsupportedSpecializationTest {
+
+    @Test
+    public void testUndefined1() {
+        TestRootNode<Undefined1> root = TestHelper.createRoot(Undefined1Factory.getInstance());
+        try {
+            TestHelper.executeWith(root, "");
+            Assert.fail();
+        } catch (UnsupportedSpecializationException e) {
+            Assert.assertNotNull(e.getSuppliedValues());
+            Assert.assertEquals(1, e.getSuppliedValues().length);
+            Assert.assertEquals("", e.getSuppliedValues()[0]);
+            Assert.assertEquals(root.getNode(), e.getNode());
+        }
+    }
+
+    @NodeChild("a")
+    abstract static class Undefined1 extends ValueNode {
+
+        @Specialization
+        public int doInteger(@SuppressWarnings("unused") int a) {
+            throw new AssertionError();
+        }
+    }
+
+    // TODO more tests required
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api.dsl/src/com/oracle/truffle/api/dsl/UnsupportedSpecializationException.java	Wed Jan 29 21:26:26 2014 +0100
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2012, 2012, 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 com.oracle.truffle.api.dsl;
+
+import java.util.*;
+
+import com.oracle.truffle.api.nodes.*;
+
+/**
+ * Thrown by the generated code of Truffle-DSL if no compatible Specialization could be found for
+ * the provided values.
+ */
+public final class UnsupportedSpecializationException extends RuntimeException {
+
+    private static final long serialVersionUID = -2122892028296836269L;
+
+    private final Node node;
+    private final Object[] suppliedValues;
+
+    public UnsupportedSpecializationException(Node node, Object... suppliedValues) {
+        super("Unexpected values provided for " + node + ": " + Arrays.toString(suppliedValues));
+        this.node = node;
+        this.suppliedValues = suppliedValues;
+    }
+
+    /**
+     * Returns the {@link Node} that caused the this {@link UnsupportedSpecializationException}.
+     */
+    public Node getNode() {
+        return node;
+    }
+
+    /**
+     * Returns the dynamic values that were supplied to the node.
+     */
+    public Object[] getSuppliedValues() {
+        return suppliedValues;
+    }
+
+}

--- a/graal/com.oracle.truffle.dsl.processor/src/com/oracle/truffle/dsl/processor/node/NodeCodeGenerator.java	Wed Jan 29 20:49:09 2014 +0100
+++ b/graal/com.oracle.truffle.dsl.processor/src/com/oracle/truffle/dsl/processor/node/NodeCodeGenerator.java	Wed Jan 29 21:26:26 2014 +0100
@@ -331,11 +331,10 @@
     }
 
     protected void emitEncounteredSynthetic(CodeTreeBuilder builder, TemplateMethod current) {
-        builder.startThrow().startNew(getContext().getType(UnsupportedOperationException.class));
-        builder.startCall("createInfo0");
-        builder.doubleQuote("Unsupported values");
+        builder.startThrow().startNew(getContext().getType(UnsupportedSpecializationException.class));
+        builder.string("this");
         addInternalValueParameterNames(builder, current, current, null, false, null);
-        builder.end().end().end();
+        builder.end().end();
     }
 
     private static List<ExecutableElement> findUserConstructors(TypeMirror nodeType) {