additional checkstyle fixes after rebase

truffle/src/com.oracle.truffle.api.bytecode.test/src/com/oracle/truffle/api/bytecode/test/error_tests/ErrorTests.java

@@ -924,10 +924,12 @@ public boolean fromInt(int x) {
         }
     }
 
+    // Checkstyle: stop
     @ExpectError("%")
     @TypeSystem
     private class ErroredTypeSystem {
     }
+    // Checkstyle: resume
 
     @ProvidedTags({RootTag.class, RootBodyTag.class})
     public class ErrorLanguage extends TruffleLanguage<Object> {

truffle/src/com.oracle.truffle.api.debug.test/src/com/oracle/truffle/api/debug/test/DebuggerContextsTest.java

@@ -256,7 +256,7 @@ public void testInContextEval() {
         }
     }
 
-    private static class TestContextsListener implements DebugContextsListener {
+    private static final class TestContextsListener implements DebugContextsListener {
 
         final List<ContextEvent> events = Collections.synchronizedList(new ArrayList<>());
 

truffle/src/com.oracle.truffle.api.debug.test/src/com/oracle/truffle/api/debug/test/DebuggerThreadsTest.java

@@ -211,7 +211,7 @@ public void onSuspend(SuspendedEvent event) {
         }
     }
 
-    private static class TestThreadsListener implements DebugThreadsListener {
+    private static final class TestThreadsListener implements DebugThreadsListener {
 
         final List<ThreadEvent> events = Collections.synchronizedList(new ArrayList<>());
 

truffle/src/com.oracle.truffle.api.debug/src/com/oracle/truffle/api/debug/Breakpoint.java

@@ -584,7 +584,7 @@ private void installInstrumentation(Instrumenter instrumenter) {
 
     // We resolve breakpoints only in sources that are executed.
     // This prevents from premature breakpoint resolution to too distant locations.
-    private class LocationsInExecutedSources implements LoadSourceSectionListener, ExecuteSourceListener {
+    private final class LocationsInExecutedSources implements LoadSourceSectionListener, ExecuteSourceListener {
 
         private final EconomicMap<Source, SourceSection> loadedSections = EconomicMap.create(Equivalence.IDENTITY_WITH_SYSTEM_HASHCODE);
         private final EconomicSet<Source> executedSources = EconomicSet.create(Equivalence.IDENTITY_WITH_SYSTEM_HASHCODE);
@@ -1248,7 +1248,7 @@ public interface ResolveListener {
         void breakpointResolved(Breakpoint breakpoint, SourceSection section);
     }
 
-    private class BreakpointNodeFactory implements ExecutionEventNodeFactory {
+    private final class BreakpointNodeFactory implements ExecutionEventNodeFactory {
 
         @Override
         public ExecutionEventNode create(EventContext context) {

truffle/src/com.oracle.truffle.api.debug/src/com/oracle/truffle/api/debug/SuspendedEvent.java

@@ -1069,7 +1069,7 @@ private static List<DebugStackTraceElement> getAsynchronousStackFrames(DebuggerS
         }
 
         // This implementation prevents from calling size()
-        private class Itr implements Iterator<List<DebugStackTraceElement>> {
+        private final class Itr implements Iterator<List<DebugStackTraceElement>> {
             int cursor = 0;
 
             @Override

truffle/src/com.oracle.truffle.api.dsl.test/src/com/oracle/truffle/api/dsl/test/FallbackTest.java

@@ -263,7 +263,7 @@ public void testFallback6() {
     }
 
     @SuppressWarnings("serial")
-    private static class FallbackException extends RuntimeException {
+    private static final class FallbackException extends RuntimeException {
     }
 
     @NodeChild("a")

truffle/src/com.oracle.truffle.api.dsl.test/src/com/oracle/truffle/api/dsl/test/ImportGuardsTest.java

@@ -148,7 +148,7 @@ int do1(int a) {
         }
     }
 
-    private static class Imports2 {
+    private static final class Imports2 {
 
     }
 

truffle/src/com.oracle.truffle.api.dsl.test/src/com/oracle/truffle/api/dsl/test/NodeChildNoNameTest.java

@@ -84,7 +84,7 @@ public void testThreeArg() {
         Assert.assertEquals(126, TestHelper.createCallTarget(arg).call());
     }
 
-    private static class ConstantNode extends ValueNode {
+    private static final class ConstantNode extends ValueNode {
 
         @Override
         public Object execute(VirtualFrame frame) {

truffle/src/com.oracle.truffle.api.instrumentation.test/src/com/oracle/truffle/api/instrumentation/test/GenerateWrapperTest.java

@@ -1023,7 +1023,7 @@ public boolean isInstrumentable() {
 
     @ExpectError("Class must not be private to generate a wrapper.")
     @GenerateWrapper
-    private static class ErrorNode2 extends Node implements InstrumentableNode {
+    private static final class ErrorNode2 extends Node implements InstrumentableNode {
 
         public WrapperNode createWrapper(ProbeNode probe) {
             return null;

truffle/src/com.oracle.truffle.api.instrumentation.test/src/com/oracle/truffle/api/instrumentation/test/InstrumentationNoExceptionsTest.java

@@ -440,7 +440,7 @@ public void onReturnExceptional(EventContext ctx, VirtualFrame frame, Throwable
     }
 
     @SuppressWarnings("serial")
-    private static class MyInstrumentException extends RuntimeException {
+    private static final class MyInstrumentException extends RuntimeException {
     }
 
 }

truffle/src/com.oracle.truffle.api.instrumentation.test/src/com/oracle/truffle/api/instrumentation/test/InstrumentationTest.java

@@ -367,7 +367,7 @@ public void testLanguageInstrumentationAndExceptions() throws IOException {
     }
 
     @SuppressWarnings("serial")
-    private static class MyLanguageException extends RuntimeException {
+    private static final class MyLanguageException extends RuntimeException {
 
     }
 
@@ -1384,7 +1384,7 @@ public void testUsedTagNotRequired1() throws IOException {
     @Registration(id = "testUsedTagNotRequired1", services = Object.class)
     public static class TestUsedTagNotRequired1 extends TruffleInstrument {
 
-        private static class Foobar {
+        private static final class Foobar {
 
         }
 

truffle/src/com.oracle.truffle.api.instrumentation.test/src/com/oracle/truffle/api/instrumentation/test/InstrumentationTestLanguage.java

@@ -3780,7 +3780,7 @@ Object getMetaObject() {
 
     }
 
-    private static class StringBuilderWrapper {
+    private static final class StringBuilderWrapper {
         private final StringBuilder delegate = new StringBuilder();
 
         @TruffleBoundary
@@ -3857,7 +3857,7 @@ static InstrumentContext get(Node node) {
         return REFERENCE.get(node);
     }
 
-    private static class WeakSet<T> extends AbstractSet<T> {
+    private static final class WeakSet<T> extends AbstractSet<T> {
 
         private final Map<T, Void> map = new WeakHashMap<>();
 

truffle/src/com.oracle.truffle.api.instrumentation.test/src/com/oracle/truffle/api/instrumentation/test/SourceListenerTest.java

@@ -393,7 +393,7 @@ public void testLoadSourceException() throws IOException {
         }
     }
 
-    private static class TestLoadSourceExceptionClass extends RuntimeException {
+    private static final class TestLoadSourceExceptionClass extends RuntimeException {
 
         private static final long serialVersionUID = 1L;
 

truffle/src/com.oracle.truffle.api.instrumentation.test/src/com/oracle/truffle/api/instrumentation/test/SourceSectionListenerTest.java

@@ -373,7 +373,7 @@ public void onReturnExceptional(EventContext c, VirtualFrame frame, Throwable ex
         }
     };
 
-    private static class TestLoadSourceSectionExceptionClass extends RuntimeException {
+    private static final class TestLoadSourceSectionExceptionClass extends RuntimeException {
 
         private static final long serialVersionUID = 1L;
 

truffle/src/com.oracle.truffle.api.instrumentation.test/src/com/oracle/truffle/api/instrumentation/test/TagsTest.java

@@ -82,12 +82,12 @@
 
 public class TagsTest {
 
-    private static class MyTag extends Tag {
+    private static final class MyTag extends Tag {
 
     }
 
     @Tag.Identifier("MyTagWithIdentifier")
-    private static class MyTagWithIdentifier extends Tag {
+    private static final class MyTagWithIdentifier extends Tag {
 
     }
 

truffle/src/com.oracle.truffle.api.instrumentation.test/src/com/oracle/truffle/api/instrumentation/test/VariablesScopeTest.java

@@ -194,7 +194,7 @@ private static boolean isNull(Object object) {
         return INTEROP.isNull(object);
     }
 
-    private static class ILScopeTester implements TestScopeInstrument.Tester {
+    private static final class ILScopeTester implements TestScopeInstrument.Tester {
 
         public void doTestScope(TruffleInstrument.Env env, Node node, VirtualFrame frame, boolean nodeEnter) throws Exception {
             assertTrue(NodeLibrary.getUncached().hasScope(node, null));
@@ -261,7 +261,7 @@ private static void doTestTopScope(TruffleInstrument.Env env) throws Unsupported
         }
     }
 
-    private static class DefaultScopeTester implements TestScopeInstrument.Tester {
+    private static final class DefaultScopeTester implements TestScopeInstrument.Tester {
 
         private final StringBuilder visitedLocations = new StringBuilder();
 
@@ -620,7 +620,7 @@ final Object getScope(Frame frame, @SuppressWarnings("unused") boolean nodeEnter
         }
     }
 
-    private static class CustomScopeTester implements TestScopeInstrument.Tester {
+    private static final class CustomScopeTester implements TestScopeInstrument.Tester {
 
         @Override
         public void doTestScope(TruffleInstrument.Env env, Node node, VirtualFrame frame, boolean nodeEnter) {

truffle/src/com.oracle.truffle.api.instrumentation.test/src/com/oracle/truffle/api/instrumentation/test/examples/DebuggerExample.java

@@ -172,7 +172,7 @@ public void onReturnExceptional(EventContext context, VirtualFrame frame, Throwa
             }
         }
 
-        private class Stepping implements ExecutionEventListener {
+        private final class Stepping implements ExecutionEventListener {
 
             public void onEnter(EventContext context, VirtualFrame frame) {
                 ontStatementStep(context);

truffle/src/com.oracle.truffle.api.instrumentation/src/com/oracle/truffle/api/instrumentation/AllocationReporter.java

@@ -418,7 +418,7 @@ private static Object createComplexObject() {
         return null;
     }
 
-    private static class MyTruffleObject {
+    private static final class MyTruffleObject {
     }
 
 }

truffle/src/com.oracle.truffle.api.instrumentation/src/com/oracle/truffle/api/instrumentation/InstrumentationHandler.java

@@ -1689,7 +1689,7 @@ protected void postVisitNotifications(Set<Class<?>> providedTags, SourceSection
      * visitorBuilder.buildVisitor();
      * </pre>
      */
-    private class VisitorBuilder {
+    private final class VisitorBuilder {
         List<VisitOperation> operations = new ArrayList<>();
         boolean shouldMaterializeSyntaxNodes;
 

truffle/src/com.oracle.truffle.api.library.test/src/com/oracle/truffle/api/library/test/ExportLibraryTest.java

@@ -181,10 +181,10 @@ static class ExportsTestObjectError1 {
 
     @ExportLibrary(ExportLibraryTestLibrary.class)
     @ExpectError("The exported type must not be private. Increase visibility to resolve this.")
-    private static class ExportsTestObjectError2 {
+    private static final class ExportsTestObjectError2 {
         @SuppressWarnings("static-method")
         @ExportMessage
-        final Object m0() {
+        Object m0() {
             return null;
         }
     }
@@ -213,7 +213,7 @@ private Object m0(@SuppressWarnings("unused") @Cached("null") Object foo) {
     static class ExportsTestObjectError5 {
         @ExpectError("Exported message node class must not be private.")
         @ExportMessage
-        private static class M0 {
+        private static final class M0 {
         }
     }
 

truffle/src/com.oracle.truffle.api.library.test/src/com/oracle/truffle/api/library/test/ExportMethodTest.java

@@ -153,11 +153,11 @@ public void test() {
         assertEquals("foo", getUncached(ExportsTestLibrary1.class, o).foo(o, 42));
     }
 
-    private static class TestSubInterface implements TestInterface {
+    private static final class TestSubInterface implements TestInterface {
 
     }
 
-    private static class TestSubClass extends TestClass {
+    private static final class TestSubClass extends TestClass {
 
     }
 

truffle/src/com.oracle.truffle.api.library.test/src/com/oracle/truffle/api/library/test/ExportNodeTest.java

@@ -551,7 +551,7 @@ static class TestObjectError3 {
 
         @ExportMessage
         @ExpectError("Exported message node class must not be private.")
-        private static class Foo {
+        private static final class Foo {
 
             static Foo create() {
                 return null;

truffle/src/com.oracle.truffle.api.staticobject.test/src/com/oracle/truffle/api/staticobject/test/VisibilityTest.java

@@ -46,7 +46,7 @@ static Class<?> getPrivateClass() {
         return PrivateClass.class;
     }
 
-    private static class PrivateClass {
+    private static final class PrivateClass {
 
     }
 }

truffle/src/com.oracle.truffle.api/src/com/oracle/truffle/api/impl/Accessor.java

@@ -1462,7 +1462,7 @@ public final void startOSRFrameTransfer(FrameWithoutBoxing target) {
 
 // A separate class to break the cycle such that Accessor can fully initialize
 // before ...Accessor classes static initializers run, which call methods from Accessor.
-    private static class Constants {
+    private static final class Constants {
 
         private static final Accessor.LanguageSupport LANGUAGE;
         private static final Accessor.NodeSupport NODES;

truffle/src/com.oracle.truffle.dsl.processor/src/com/oracle/truffle/dsl/processor/java/ElementUtils.java

@@ -1303,7 +1303,7 @@ public static Object unboxAnnotationValue(AnnotationValue value) {
         return value.accept(new AnnotationValueVisitorImpl(), null);
     }
 
-    private static class AnnotationValueVisitorImpl extends AbstractAnnotationValueVisitor8<Object, Void> {
+    private static final class AnnotationValueVisitorImpl extends AbstractAnnotationValueVisitor8<Object, Void> {
 
         @Override
         public Object visitBoolean(boolean b, Void p) {

truffle/src/com.oracle.truffle.dsl.processor/src/com/oracle/truffle/dsl/processor/java/transform/OrganizedImports.java

@@ -497,7 +497,7 @@ public void visitImport(CodeImport e, Void p) {
 
     }
 
-    private class ImportTypeReferenceVisitor extends TypeReferenceVisitor {
+    private final class ImportTypeReferenceVisitor extends TypeReferenceVisitor {
 
         @Override
         public void visitStaticFieldReference(Element enclosedType, TypeMirror type, String elementName) {

truffle/src/com.oracle.truffle.dsl.processor/src/com/oracle/truffle/dsl/processor/parser/NodeParser.java

@@ -4263,7 +4263,7 @@ private static boolean isRecursiveType(NodeData node, TypeElement parameterType)
 
     private final Map<String, NodeData> nodeDataCache = new HashMap<>();
 
-    private static class FactoryMethodCacheKey {
+    private static final class FactoryMethodCacheKey {
     }
 
     private List<CodeExecutableElement> parseNodeFactoryMethods(TypeMirror nodeType) {
@@ -4911,7 +4911,7 @@ public int hashCode() {
             return hashCode;
         }
 
-        private static class DSLExpressionHash implements DSLExpressionVisitor {
+        private static final class DSLExpressionHash implements DSLExpressionVisitor {
             private int hash = 1;
 
             public void visitCast(Cast binary) {

truffle/src/com.oracle.truffle.nfi.backend.libffi/src/com/oracle/truffle/nfi/backend/libffi/LibFFIContext.java

@@ -113,7 +113,7 @@ public void destroy() {
         }
     }
 
-    private class NativeEnvSupplier implements Supplier<NativeEnv> {
+    private final class NativeEnvSupplier implements Supplier<NativeEnv> {
 
         @Override
         public NativeEnv get() {

truffle/src/com.oracle.truffle.nfi.test/src/com/oracle/truffle/nfi/test/WrappedPrimitiveNFITest.java

@@ -59,7 +59,7 @@
 @Parameterized.UseParametersRunnerFactory(TruffleRunner.ParametersFactory.class)
 public class WrappedPrimitiveNFITest extends NFITest {
 
-    private static class TestObject implements TruffleObject {
+    private static final class TestObject implements TruffleObject {
     }
 
     private static final Object[] ARGUMENTS = {

truffle/src/com.oracle.truffle.sl.test/src/com/oracle/truffle/sl/test/SLInstrumentTest.java

@@ -660,7 +660,7 @@ public int read() throws IOException {
         assertFalse(redoIO.beforePop);
     }
 
-    private static class RuntimeInterruptedException extends AbstractTruffleException {
+    private static final class RuntimeInterruptedException extends AbstractTruffleException {
         private static final long serialVersionUID = -4735601164894088571L;
     }
 

truffle/src/com.oracle.truffle.sl.test/src/com/oracle/truffle/sl/test/SLInteropObjectTest.java

@@ -100,7 +100,7 @@ public void testNewForeign() {
         Assert.assertEquals(20, ret.asLong());
     }
 
-    private static class TestType implements ProxyInstantiable {
+    private static final class TestType implements ProxyInstantiable {
 
         @Override
         public Object newInstance(Value... arguments) {
@@ -109,7 +109,7 @@ public Object newInstance(Value... arguments) {
 
     }
 
-    private static class TestObject implements ProxyObject {
+    private static final class TestObject implements ProxyObject {
 
         private long value;
 

truffle/src/com.oracle.truffle.sl/src/com/oracle/truffle/sl/parser/SLBaseParser.java

@@ -133,7 +133,7 @@ protected TruffleString asTruffleString(Token literalToken, boolean removeQuotes
 
     // ------------------------------- locals handling --------------------------
 
-    private static class FindLocalsVisitor extends SimpleLanguageBaseVisitor<Void> {
+    private static final class FindLocalsVisitor extends SimpleLanguageBaseVisitor<Void> {
         boolean entered = false;
         List<Token> results = new ArrayList<>();
 

truffle/src/com.oracle.truffle.sl/src/com/oracle/truffle/sl/parser/SLNodeParser.java

@@ -192,7 +192,7 @@ private SLStringLiteralNode createString(Token name, boolean removeQuotes) {
         return node;
     }
 
-    private class SLStatementVisitor extends SimpleLanguageBaseVisitor<SLStatementNode> {
+    private final class SLStatementVisitor extends SimpleLanguageBaseVisitor<SLStatementNode> {
         @Override
         public SLStatementNode visitBlock(BlockContext ctx) {
             List<TruffleString> newLocals = enterBlock(ctx);
@@ -326,7 +326,7 @@ public SLStatementNode visitChildren(RuleNode arg0) {
         }
     }
 
-    private class SLExpressionVisitor extends SimpleLanguageBaseVisitor<SLExpressionNode> {
+    private final class SLExpressionVisitor extends SimpleLanguageBaseVisitor<SLExpressionNode> {
         @Override
         public SLExpressionNode visitExpression(ExpressionContext ctx) {
             return createBinary(ctx.logic_term(), ctx.OP_OR());