diff -r 014cf6234586 -r fc73f83cd563 test/tools/javac/tree/AbstractTreeScannerTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/tools/javac/tree/AbstractTreeScannerTest.java	Thu Sep 09 13:31:28 2010 -0700
@@ -0,0 +1,284 @@
+/*
+ * Copyright (c) 2010, 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.
+ */
+
+import java.io.*;
+import java.lang.reflect.*;
+import java.util.*;
+import javax.tools.*;
+
+import com.sun.source.tree.CompilationUnitTree;
+import com.sun.source.tree.Tree;
+import com.sun.source.util.JavacTask;
+import com.sun.tools.javac.api.JavacTool;
+import com.sun.tools.javac.tree.JCTree;
+import com.sun.tools.javac.tree.JCTree.JCCompilationUnit;
+import com.sun.tools.javac.util.List;
+
+public abstract class AbstractTreeScannerTest {
+
+    /**
+     * Run the program. A base directory can be provided for file arguments.
+     * In jtreg mode, the -r option can be given to change the default base
+     * directory to the test root directory. For other options, see usage().
+     * @param baseDir base directory for any file arguments.
+     * @param args command line args
+     * @return true if successful or in gui mode
+     */
+    boolean run(File baseDir, String... args) {
+        if (args.length == 0) {
+            usage(System.out);
+            return true;
+        }
+
+        ArrayList<File> files = new ArrayList<File>();
+        for (int i = 0; i < args.length; i++) {
+            String arg = args[i];
+            if (arg.equals("-q"))
+                quiet = true;
+            else if (arg.equals("-v"))
+                verbose = true;
+            else if (arg.equals("-r")) {
+                File d = baseDir;
+                while (!new File(d, "TEST.ROOT").exists()) {
+                    d = d.getParentFile();
+                    if (d == null)
+                        throw new Error("cannot find TEST.ROOT");
+                }
+                baseDir = d;
+            }
+            else if (arg.startsWith("-"))
+                throw new Error("unknown option: " + arg);
+            else {
+                while (i < args.length)
+                    files.add(new File(baseDir, args[i++]));
+            }
+        }
+
+        for (File file: files) {
+            if (file.exists())
+                test(file);
+            else
+                error("File not found: " + file);
+        }
+
+        if (fileCount != 1)
+            System.err.println(fileCount + " files read");
+        System.err.println(treeCount + " tree nodes compared");
+        if (errors > 0)
+            System.err.println(errors + " errors");
+
+        return (errors == 0);
+    }
+
+    /**
+     * Print command line help.
+     * @param out output stream
+     */
+    void usage(PrintStream out) {
+        out.println("Usage:");
+        out.println("  java " + getClass().getName() + " options... files...");
+        out.println("");
+        out.println("where options include:");
+        out.println("-q        Quiet: don't report on inapplicable files");
+        out.println("-v        Verbose: report on files as they are being read");
+        out.println("");
+        out.println("files may be directories or files");
+        out.println("directories will be scanned recursively");
+        out.println("non java files, or java files which cannot be parsed, will be ignored");
+        out.println("");
+    }
+
+    /**
+     * Test a file. If the file is a directory, it will be recursively scanned
+     * for java files.
+     * @param file the file or directory to test
+     */
+    void test(File file) {
+        if (file.isDirectory()) {
+            for (File f: file.listFiles()) {
+                test(f);
+            }
+            return;
+        }
+
+        if (file.isFile() && file.getName().endsWith(".java")) {
+            try {
+                if (verbose)
+                    System.err.println(file);
+                fileCount++;
+                treeCount += test(read(file));
+            } catch (ParseException e) {
+                if (!quiet) {
+                    error("Error parsing " + file + "\n" + e.getMessage());
+                }
+            } catch (IOException e) {
+                error("Error reading " + file + ": " + e);
+            }
+            return;
+        }
+
+        if (!quiet)
+            error("File " + file + " ignored");
+    }
+
+    abstract int test(JCCompilationUnit t);
+
+    /**
+     * Read a file.
+     * @param file the file to be read
+     * @return the tree for the content of the file
+     * @throws IOException if any IO errors occur
+     * @throws TreePosTest.ParseException if any errors occur while parsing the file
+     */
+    JCCompilationUnit read(File file) throws IOException, ParseException {
+        StringWriter sw = new StringWriter();
+        PrintWriter pw = new PrintWriter(sw);
+        Reporter r = new Reporter(pw);
+        JavacTool tool = JavacTool.create();
+        StandardJavaFileManager fm = tool.getStandardFileManager(r, null, null);
+        Iterable<? extends JavaFileObject> files = fm.getJavaFileObjects(file);
+        JavacTask task = tool.getTask(pw, fm, r, Collections.<String>emptyList(), null, files);
+        Iterable<? extends CompilationUnitTree> trees = task.parse();
+        pw.flush();
+        if (r.errors > 0)
+            throw new ParseException(sw.toString());
+        Iterator<? extends CompilationUnitTree> iter = trees.iterator();
+        if (!iter.hasNext())
+            throw new Error("no trees found");
+        JCCompilationUnit t = (JCCompilationUnit) iter.next();
+        if (iter.hasNext())
+            throw new Error("too many trees found");
+        return t;
+    }
+
+    /**
+     * Report an error. When the program is complete, the program will either
+     * exit or throw an Error if any errors have been reported.
+     * @param msg the error message
+     */
+    void error(String msg) {
+        System.err.println(msg);
+        errors++;
+    }
+
+    /**
+     *  Report an error for a specific tree node.
+     *  @param file the source file for the tree
+     *  @param t    the tree node
+     *  @param label an indication of the error
+     */
+    void error(JavaFileObject file, Tree tree, String msg) {
+        JCTree t = (JCTree) tree;
+        error(file.getName() + ":" + getLine(file, t) + ": " + msg + " " + trim(t, 64));
+    }
+
+    /**
+     * Get a trimmed string for a tree node, with normalized white space and limited length.
+     */
+    String trim(Tree tree, int len) {
+        JCTree t = (JCTree) tree;
+        String s = t.toString().replaceAll("[\r\n]+", " ").replaceAll(" +", " ");
+        return (s.length() < len) ? s : s.substring(0, len);
+    }
+
+    /** Number of files that have been analyzed. */
+    int fileCount;
+    /** Number of trees that have been successfully compared. */
+    int treeCount;
+    /** Number of errors reported. */
+    int errors;
+    /** Flag: don't report irrelevant files. */
+    boolean quiet;
+    /** Flag: report files as they are processed. */
+    boolean verbose;
+
+
+    /**
+     * Thrown when errors are found parsing a java file.
+     */
+    private static class ParseException extends Exception {
+        ParseException(String msg) {
+            super(msg);
+        }
+    }
+
+    /**
+     * DiagnosticListener to report diagnostics and count any errors that occur.
+     */
+    private static class Reporter implements DiagnosticListener<JavaFileObject> {
+        Reporter(PrintWriter out) {
+            this.out = out;
+        }
+
+        public void report(Diagnostic<? extends JavaFileObject> diagnostic) {
+            out.println(diagnostic);
+            switch (diagnostic.getKind()) {
+                case ERROR:
+                    errors++;
+            }
+        }
+        int errors;
+        PrintWriter out;
+    }
+
+    /**
+     * Get the set of fields for a tree node that may contain child tree nodes.
+     * These are the fields that are subtypes of JCTree or List.
+     * The results are cached, based on the tree's tag.
+     */
+    Set<Field> getFields(JCTree tree) {
+        Set<Field> fields = map.get(tree.getTag());
+        if (fields == null) {
+            fields = new HashSet<Field>();
+            for (Field f: tree.getClass().getFields()) {
+                Class<?> fc = f.getType();
+                if (JCTree.class.isAssignableFrom(fc) || List.class.isAssignableFrom(fc))
+                    fields.add(f);
+            }
+            map.put(tree.getTag(), fields);
+        }
+        return fields;
+    }
+    // where
+    Map<Integer, Set<Field>> map = new HashMap<Integer,Set<Field>>();
+
+    /** Get the line number for the primary position for a tree.
+     * The code is intended to be simple, although not necessarily efficient.
+     * However, note that a file manager such as JavacFileManager is likely
+     * to cache the results of file.getCharContent, avoiding the need to read
+     * the bits from disk each time this method is called.
+     */
+    int getLine(JavaFileObject file, JCTree tree) {
+        try {
+            CharSequence cs = file.getCharContent(true);
+            int line = 1;
+            for (int i = 0; i < tree.pos; i++) {
+                if (cs.charAt(i) == '\n') // jtreg tests always use Unix line endings
+                    line++;
+            }
+            return line;
+        } catch (IOException e) {
+            return -1;
+        }
+    }
+}