diff -r 475eb15dfdad -r f91144b7da75 src/share/classes/com/sun/tools/sjavac/Transformer.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/classes/com/sun/tools/sjavac/Transformer.java	Mon Feb 04 18:08:53 2013 -0500
@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 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.sun.tools.sjavac;
+
+import java.io.PrintStream;
+import java.net.URI;
+import java.util.Set;
+import java.util.Map;
+
+/**
+ * The transform interface is used to transform content inside a package, from one form to another.
+ * Usually the output form is an unpredictable number of output files. (eg class files)
+ * but can also be an unpredictable number of generated source files (eg idl2java)
+ * or a single predictable output file (eg when copying,cleaning or compiling a properties file).
+ *
+ * <p><b>This is NOT part of any supported API.
+ * If you write code that depends on this, you do so at your own
+ * risk.  This code and its internal interfaces are subject to change
+ * or deletion without notice.</b></p>
+ */
+public interface Transformer
+{
+    /**
+     * The transform method takes a set of package names, mapped to their source files and to the
+     * pubapis of the packages.
+     *
+     * The transform implementation must:
+     *    store the names of the generated artifacts for each package into package_artifacts
+     *    store found dependencies to other packages into the supplied set package_dependencies
+     *    store the public api for a package into the supplied set package_pubapis
+     *
+     * Any benign messages as a result of running the transform
+     * are written into stdout, and errors are written to stderr.
+     *
+     * The debug_level can be 0=silent (only warnings and errors) 1=normal 2=verbose 3 or greater=debug
+     * setExtra is used to set the extra information information that can be passed on
+     * the command line to the smart javac wrapper.
+     *
+     * If sjavac is building incrementally from an existing javac_state, the var incremental is true.
+     *
+     * The transformer will only be called if some source in the package (or dependency) has
+     * a modified timestamp. Thus the transformer might get called with many sources, of which
+     * only one has changed. The transformer is allowed to regenerate all artifacts but
+     * a better transformer will only write those artifacts that need updating.
+     *
+     * However the transformer must verify that the existing artifacts really are there!
+     * and it must always update package_artifacts, package_dependencies, and package_pubapis correctly.
+     * This means that at least for Java source, it will always have to recompile the sources.
+     *
+     * The transformer is allowed to put files anywhere in the dest_root.
+     * An example of this is, can be the META-INF transformer that copy files
+     * below META-INF directories to the single META-INF directory below dest_root.
+     *
+     * False is returned if there was an error that prevented the transform.
+     * I.e. something was printed on stderr.
+     *
+     * If num_cores is set to a non-zero value. The transform should attempt to use no more than these
+     * number of threads for heavy work.
+     */
+    boolean transform(Map<String,Set<URI>> pkgSrcs,
+                      Set<URI>             visibleSources,
+                      Map<URI,Set<String>> visibleClasses,
+                      Map<String,Set<String>> oldPackageDependencies,
+                      URI destRoot,
+                      Map<String,Set<URI>>    packageArtifacts,
+                      Map<String,Set<String>> packageDependencies,
+                      Map<String,String>      packagePublicApis,
+                      int debugLevel,
+                      boolean incremental,
+                      int numCores,
+                      PrintStream out,
+                      PrintStream err);
+
+    void setExtra(String e);
+    void setExtra(String[] args);
+}