--- /dev/null	2016-05-31 09:42:47.975716356 -0700
+++ new/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.core.common/src/org/graalvm/compiler/core/common/CompilationIdentifier.java	2016-12-09 00:47:03.421883060 -0800
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2016, 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 org.graalvm.compiler.core.common;
+
+import jdk.vm.ci.code.CompilationRequest;
+
+/**
+ * A unique identifier for a compilation. Compiled code can be mapped to a single compilation id.
+ * The reverse is not true since the compiler might bailout in which case no code is installed.
+ */
+public interface CompilationIdentifier {
+
+    enum Verbosity {
+        /**
+         * Only the unique identifier of the compilation.
+         */
+        ID,
+        /**
+         * Only the name of the compilation unit.
+         */
+        NAME,
+        /**
+         * {@link #ID} + a readable description.
+         */
+        DETAILED
+    }
+
+    CompilationRequestIdentifier INVALID_COMPILATION_ID = new CompilationRequestIdentifier() {
+
+        @Override
+        public String toString() {
+            return toString(Verbosity.DETAILED);
+        }
+
+        @Override
+        public String toString(Verbosity verbosity) {
+            return "InvalidCompilationID";
+        }
+
+        @Override
+        public CompilationRequest getRequest() {
+            return null;
+        }
+
+    };
+
+    /**
+     * This method is a shortcut for {@link #toString(Verbosity)} with {@link Verbosity#DETAILED}.
+     */
+    @Override
+    String toString();
+
+    /**
+     * Creates a String representation for this compilation identifier with a given
+     * {@link Verbosity}.
+     */
+    String toString(Verbosity verbosity);
+}