diff -r 000000000000 -r 959103a6100f make/tools/crules/MutableFieldsAnalyzer.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/make/tools/crules/MutableFieldsAnalyzer.java	Wed Apr 27 01:34:52 2016 +0800
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 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 crules;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import com.sun.tools.javac.code.Kinds;
+import com.sun.tools.javac.tree.TreeScanner;
+
+import static com.sun.source.util.TaskEvent.Kind;
+import static com.sun.tools.javac.code.Flags.*;
+import static com.sun.tools.javac.tree.JCTree.JCVariableDecl;
+
+public class MutableFieldsAnalyzer extends AbstractCodingRulesAnalyzer {
+
+    public MutableFieldsAnalyzer() {
+        treeVisitor = new MutableFieldsVisitor();
+        eventKind = Kind.ANALYZE;
+    }
+
+    public String getName() {
+        return "mutable_fields_analyzer";
+    }
+
+    private boolean ignoreField(String className, String field) {
+        List<String> currentFieldsToIgnore =
+                classFieldsToIgnoreMap.get(className);
+        if (currentFieldsToIgnore != null) {
+            for (String fieldToIgnore : currentFieldsToIgnore) {
+                if (field.equals(fieldToIgnore)) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    class MutableFieldsVisitor extends TreeScanner {
+
+        @Override
+        public void visitVarDef(JCVariableDecl tree) {
+            boolean isJavacPack = tree.sym.outermostClass().fullname.toString()
+                    .contains(packageToCheck);
+            if (isJavacPack &&
+                (tree.sym.flags() & SYNTHETIC) == 0 &&
+                tree.sym.owner.kind == Kinds.TYP) {
+                if (!ignoreField(tree.sym.owner.flatName().toString(),
+                        tree.getName().toString())) {
+                    boolean enumClass = (tree.sym.owner.flags() & ENUM) != 0;
+                    boolean nonFinalStaticEnumField =
+                            (tree.sym.flags() & (ENUM | FINAL)) == 0;
+                    boolean nonFinalStaticField =
+                            (tree.sym.flags() & STATIC) != 0 &&
+                            (tree.sym.flags() & FINAL) == 0;
+                    if (enumClass ? nonFinalStaticEnumField : nonFinalStaticField) {
+                        messages.error(tree, "crules.err.var.must.be.final", tree);
+                    }
+                }
+            }
+            super.visitVarDef(tree);
+        }
+
+    }
+
+    private static final String packageToCheck = "com.sun.tools.javac";
+
+    private static final Map<String, List<String>> classFieldsToIgnoreMap =
+                new HashMap<String, List<String>>();
+
+    static {
+        classFieldsToIgnoreMap.
+                put("com.sun.tools.javac.util.JCDiagnostic",
+                    Arrays.asList("fragmentFormatter"));
+        classFieldsToIgnoreMap.
+                put("com.sun.tools.javac.util.JavacMessages",
+                    Arrays.asList("defaultBundle", "defaultMessages"));
+        classFieldsToIgnoreMap.
+                put("com.sun.tools.javac.file.ZipFileIndexCache",
+                    Arrays.asList("sharedInstance"));
+        classFieldsToIgnoreMap.
+                put("com.sun.tools.javac.main.JavaCompiler",
+                    Arrays.asList("versionRB"));
+        classFieldsToIgnoreMap.
+                put("com.sun.tools.javac.code.Type",
+                    Arrays.asList("moreInfo"));
+        classFieldsToIgnoreMap.
+                put("com.sun.tools.javac.util.SharedNameTable",
+                    Arrays.asList("freelist"));
+        classFieldsToIgnoreMap.
+                put("com.sun.tools.javac.util.Log",
+                    Arrays.asList("useRawMessages"));
+    }
+
+}