8265900: Use pattern matching for instanceof at module jdk.compiler(part 2)

Reviewed-by: mcimadamore

src/jdk.compiler/share/classes/com/sun/tools/javac/code/AnnoConstruct.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2021, 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
@@ -168,8 +168,8 @@ public abstract class AnnoConstruct implements AnnotatedConstruct {
         ListBuffer<Attribute.Compound> compounds = new ListBuffer<>();
         if (contained0 != null) {
             for (Attribute a : contained0)
-                if (a instanceof Attribute.Compound)
+                if (a instanceof Attribute.Compound attributeCompound)
-                    compounds = compounds.append((Attribute.Compound)a);
+                    compounds = compounds.append(attributeCompound);
         }
         return compounds.toArray(new Attribute.Compound[compounds.size()]);
     }

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Attribute.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2021, 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
@@ -87,8 +87,8 @@ public abstract class Attribute implements AnnotationValue {
         }
         @DefinedBy(Api.LANGUAGE_MODEL)
         public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {
-            if (value instanceof String)
+            if (value instanceof String str)
-                return v.visitString((String) value, p);
+                return v.visitString(str, p);
             if (value instanceof Integer) {
                 int i = (Integer) value;
                 switch (type.getTag()) {
@@ -198,12 +198,10 @@ public abstract class Attribute implements AnnotationValue {
             if (values.size() == 1) {
                 Pair<MethodSymbol, Attribute> val = values.get(0);
                 if (val.fst.getSimpleName().contentEquals("value")
-                        && val.snd instanceof Array) {
+                        && val.snd instanceof Array arr
-                    Array arr = (Array) val.snd;
+                        && arr.values.length != 0
-                    if (arr.values.length != 0
+                        && arr.values[0] instanceof Attribute.TypeCompound compound)
-                            && arr.values[0] instanceof Attribute.TypeCompound)
+                        return compound;
-                        return (Attribute.TypeCompound) arr.values[0];
-                }
             }
             return null;
         }

src/jdk.compiler/share/classes/com/sun/tools/javac/code/ClassFinder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2021, 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
@@ -209,12 +209,11 @@ public class ClassFinder {
         // Temporary, until more info is available from the module system.
         boolean useCtProps;
         JavaFileManager fm = context.get(JavaFileManager.class);
-        if (fm instanceof DelegatingJavaFileManager) {
+        if (fm instanceof DelegatingJavaFileManager delegatingJavaFileManager) {
-            fm = ((DelegatingJavaFileManager) fm).getBaseFileManager();
+            fm = delegatingJavaFileManager.getBaseFileManager();
         }
-        if (fm instanceof JavacFileManager) {
+        if (fm instanceof JavacFileManager javacFileManager) {
-            JavacFileManager jfm = (JavacFileManager) fm;
+            useCtProps = javacFileManager.isDefaultBootClassPath() && javacFileManager.isSymbolFileEnabled();
-            useCtProps = jfm.isDefaultBootClassPath() && jfm.isSymbolFileEnabled();
         } else if (fm.getClass().getName().equals("com.sun.tools.sjavac.comp.SmartFileManager")) {
             useCtProps = !options.isSet("ignore.symbol.file");
         } else {
@@ -642,27 +641,26 @@ public class ClassFinder {
 
         if (verbose && verbosePath) {
             verbosePath = false; // print once per compile
-            if (fileManager instanceof StandardJavaFileManager) {
+            if (fileManager instanceof StandardJavaFileManager standardJavaFileManager) {
-                StandardJavaFileManager fm = (StandardJavaFileManager)fileManager;
                 if (haveSourcePath && wantSourceFiles) {
                     List<Path> path = List.nil();
-                    for (Path sourcePath : fm.getLocationAsPaths(SOURCE_PATH)) {
+                    for (Path sourcePath : standardJavaFileManager.getLocationAsPaths(SOURCE_PATH)) {
                         path = path.prepend(sourcePath);
                     }
                     log.printVerbose("sourcepath", path.reverse().toString());
                 } else if (wantSourceFiles) {
                     List<Path> path = List.nil();
-                    for (Path classPath : fm.getLocationAsPaths(CLASS_PATH)) {
+                    for (Path classPath : standardJavaFileManager.getLocationAsPaths(CLASS_PATH)) {
                         path = path.prepend(classPath);
                     }
                     log.printVerbose("sourcepath", path.reverse().toString());
                 }
                 if (wantClassFiles) {
                     List<Path> path = List.nil();
-                    for (Path platformPath : fm.getLocationAsPaths(PLATFORM_CLASS_PATH)) {
+                    for (Path platformPath : standardJavaFileManager.getLocationAsPaths(PLATFORM_CLASS_PATH)) {
                         path = path.prepend(platformPath);
                     }
-                    for (Path classPath : fm.getLocationAsPaths(CLASS_PATH)) {
+                    for (Path classPath : standardJavaFileManager.getLocationAsPaths(CLASS_PATH)) {
                         path = path.prepend(classPath);
                     }
                     log.printVerbose("classpath",  path.reverse().toString());

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Directive.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2009, 2021, 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
@@ -263,11 +263,9 @@ public abstract class Directive implements ModuleElement.Directive {
         // TODO: delete?
         @Override
         public boolean equals(Object obj) {
-            if (!(obj instanceof ProvidesDirective)) {
+            return (obj instanceof ProvidesDirective directive)
-                return false;
+                    && service == directive.service
-            }
+                    && impls.equals(directive.impls);
-            ProvidesDirective other = (ProvidesDirective)obj;
-            return service == other.service && impls.equals(other.impls);
         }
 
         // TODO: delete?
@@ -359,11 +357,8 @@ public abstract class Directive implements ModuleElement.Directive {
         // TODO: delete?
         @Override
         public boolean equals(Object obj) {
-            if (!(obj instanceof UsesDirective)) {
+            return (obj instanceof UsesDirective directive)
-                return false;
+                    && service == directive.service;
-            }
-            UsesDirective other = (UsesDirective)obj;
-            return service == other.service;
         }
 
         // TODO: delete?

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Scope.java

@@ -753,8 +753,9 @@ public abstract class Scope {
         }
 
         protected Scope finalizeSingleScope(Scope impScope) {
-            if (impScope instanceof FilterImportScope && impScope.owner.kind == Kind.TYP &&
+            if (impScope instanceof FilterImportScope filterImportScope
-                ((FilterImportScope) impScope).isStaticallyImported()) {
+                    && impScope.owner.kind == Kind.TYP
+                    && filterImportScope.isStaticallyImported()) {
                 WriteableScope finalized = WriteableScope.create(impScope.owner);
 
                 for (Symbol sym : impScope.getSymbols()) {

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Symbol.java

@@ -1420,13 +1420,12 @@ public abstract class Symbol extends AnnoConstruct implements PoolConstant, Elem
         @DefinedBy(Api.LANGUAGE_MODEL)
         public List<Type> getInterfaces() {
             apiComplete();
-            if (type instanceof ClassType) {
+            if (type instanceof ClassType classType) {
-                ClassType t = (ClassType)type;
+                if (classType.interfaces_field == null) // FIXME: shouldn't be null
-                if (t.interfaces_field == null) // FIXME: shouldn't be null
+                    classType.interfaces_field = List.nil();
-                    t.interfaces_field = List.nil();
+                if (classType.all_interfaces_field != null)
-                if (t.all_interfaces_field != null)
+                    return Type.getModelTypes(classType.all_interfaces_field);
-                    return Type.getModelTypes(t.all_interfaces_field);
+                return classType.interfaces_field;
-                return t.interfaces_field;
             } else {
                 return List.nil();
             }
@@ -1435,14 +1434,13 @@ public abstract class Symbol extends AnnoConstruct implements PoolConstant, Elem
         @DefinedBy(Api.LANGUAGE_MODEL)
         public Type getSuperclass() {
             apiComplete();
-            if (type instanceof ClassType) {
+            if (type instanceof ClassType classType) {
-                ClassType t = (ClassType)type;
+                if (classType.supertype_field == null) // FIXME: shouldn't be null
-                if (t.supertype_field == null) // FIXME: shouldn't be null
+                    classType.supertype_field = Type.noType;
-                    t.supertype_field = Type.noType;
                 // An interface has no superclass; its supertype is Object.
-                return t.isInterface()
+                return classType.isInterface()
                     ? Type.noType
-                    : t.supertype_field.getModelType();
+                    : classType.supertype_field.getModelType();
             } else {
                 return Type.noType;
             }
@@ -1585,15 +1583,14 @@ public abstract class Symbol extends AnnoConstruct implements PoolConstant, Elem
             erasure_field = null;
             members_field = null;
             flags_field = 0;
-            if (type instanceof ClassType) {
+            if (type instanceof ClassType classType) {
-                ClassType t = (ClassType)type;
+                classType.setEnclosingType(Type.noType);
-                t.setEnclosingType(Type.noType);
+                classType.rank_field = -1;
-                t.rank_field = -1;
+                classType.typarams_field = null;
-                t.typarams_field = null;
+                classType.allparams_field = null;
-                t.allparams_field = null;
+                classType.supertype_field = null;
-                t.supertype_field = null;
+                classType.interfaces_field = null;
-                t.interfaces_field = null;
+                classType.all_interfaces_field = null;
-                t.all_interfaces_field = null;
             }
             clearAnnotationMetadata();
         }
@@ -1754,13 +1751,12 @@ public abstract class Symbol extends AnnoConstruct implements PoolConstant, Elem
             if (data == ElementKind.EXCEPTION_PARAMETER ||
                 data == ElementKind.RESOURCE_VARIABLE) {
                 return null;
-            } else if (data instanceof Callable<?>) {
+            } else if (data instanceof Callable<?> callableData) {
                 // In this case, this is a final variable, with an as
                 // yet unevaluated initializer.
-                Callable<?> eval = (Callable<?>)data;
                 data = null; // to make sure we don't evaluate this twice.
                 try {
-                    data = eval.call();
+                    data = callableData.call();
                 } catch (Exception ex) {
                     throw new AssertionError(ex);
                 }

src/jdk.compiler/share/classes/com/sun/tools/javac/code/SymbolMetadata.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2021, 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
@@ -276,8 +276,7 @@ public class SymbolMetadata {
                 if (attrCompound.isSynthesized() && !attrCompound.values.isEmpty()) {
                     Pair<Symbol.MethodSymbol, Attribute> val = attrCompound.values.get(0);
                     if (val.fst.getSimpleName().contentEquals("value") &&
-                            val.snd instanceof Attribute.Array) {
+                            val.snd instanceof Attribute.Array arr) {
-                        Attribute.Array arr = (Attribute.Array) val.snd;
                         if (arr.values.length != 0
                                 && arr.values[0] instanceof Attribute.Compound
                                 && arr.values[0].type == compound.type) {

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Type.java

@@ -1359,13 +1359,8 @@ public abstract class Type extends AnnoConstruct implements TypeMirror, PoolCons
 
         @Override @DefinedBy(Api.LANGUAGE_MODEL)
         public boolean equals(Object obj) {
-            if (obj instanceof ArrayType) {
+            return (obj instanceof ArrayType arrayType)
-                ArrayType that = (ArrayType)obj;
+                    && (this == arrayType || elemtype.equals(arrayType.elemtype));
-                return this == that ||
-                        elemtype.equals(that.elemtype);
-            }
-
-            return false;
         }
 
         @DefinedBy(Api.LANGUAGE_MODEL)

src/jdk.compiler/share/classes/com/sun/tools/javac/code/TypeAnnotationPosition.java

@@ -103,11 +103,9 @@ public class TypeAnnotationPosition {
 
         @Override
         public boolean equals(Object other) {
-            if (! (other instanceof TypePathEntry)) {
+            return (other instanceof TypePathEntry entry)
-                return false;
+                    && this.tag == entry.tag
-            }
+                    && this.arg == entry.arg;
-            TypePathEntry tpe = (TypePathEntry) other;
-            return this.tag == tpe.tag && this.arg == tpe.arg;
         }
 
         @Override

src/jdk.compiler/share/classes/com/sun/tools/javac/code/TypeAnnotations.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2009, 2021, 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
@@ -155,11 +155,11 @@ public class TypeAnnotations {
         }
 
         Attribute atValue = atTarget.member(names.value);
-        if (!(atValue instanceof Attribute.Array)) {
+        if (!(atValue instanceof Attribute.Array arrayVal)) {
             return null;
         }
 
-        List<Attribute> targets = ((Array)atValue).getValue();
+        List<Attribute> targets = arrayVal.getValue();
         if (targets.stream().anyMatch(a -> !(a instanceof Attribute.Enum))) {
             return null;
         }

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Types.java

@@ -3161,12 +3161,9 @@ public class Types {
 
             @Override
             public boolean equals(Object obj) {
-                if (obj instanceof Entry) {
+                return (obj instanceof Entry entry)
-                    Entry e = (Entry)obj;
+                        && entry.msym == msym
-                    return e.msym == msym && isSameType(site, e.site);
+                        && isSameType(site, entry.site);
-                } else {
-                    return false;
-                }
             }
 
             @Override
@@ -3850,10 +3847,8 @@ public class Types {
             }
             @Override
             public boolean equals(Object obj) {
-                if (!(obj instanceof TypePair))
+                return (obj instanceof TypePair typePair)
-                    return false;
+                        && isSameType(t1, typePair.t1)
-                TypePair typePair = (TypePair)obj;
-                return isSameType(t1, typePair.t1)
                         && isSameType(t2, typePair.t2);
             }
         }
@@ -4877,8 +4872,8 @@ public class Types {
         }
 
         public boolean equals(Object obj) {
-            return (obj instanceof UniqueType) &&
+            return (obj instanceof UniqueType uniqueType) &&
-                types.isSameType(type, ((UniqueType)obj).type);
+                    types.isSameType(type, uniqueType.type);
         }
 
         public String toString() {
@@ -5032,8 +5027,8 @@ public class Types {
         Attribute.Compound c = sym.attribute(syms.retentionType.tsym);
         if (c != null) {
             Attribute value = c.member(names.value);
-            if (value != null && value instanceof Attribute.Enum) {
+            if (value != null && value instanceof Attribute.Enum attributeEnum) {
-                Name levelName = ((Attribute.Enum)value).value.name;
+                Name levelName = attributeEnum.value.name;
                 if (levelName == names.SOURCE) vis = RetentionPolicy.SOURCE;
                 else if (levelName == names.CLASS) vis = RetentionPolicy.CLASS;
                 else if (levelName == names.RUNTIME) vis = RetentionPolicy.RUNTIME;

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Annotate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2021, 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
@@ -404,13 +404,9 @@ public class Annotate {
     }
     //where:
         private boolean isAttributeTrue(Attribute attr) {
-            if (attr instanceof Attribute.Constant) {
+            return (attr instanceof Attribute.Constant constant)
-                Attribute.Constant v = (Attribute.Constant) attr;
+                    && constant.type == syms.booleanType
-                if (v.type == syms.booleanType && ((Integer) v.value) != 0) {
+                    && ((Integer) constant.value) != 0;
-                    return true;
-                }
-            }
-            return false;
         }
 
     /**
@@ -447,7 +443,7 @@ public class Annotate {
     {
         // The attribute might have been entered if it is Target or Repeatable
         // Because TreeCopier does not copy type, redo this if type is null
-        if (a.attribute == null || a.type == null || !(a.attribute instanceof Attribute.TypeCompound)) {
+        if (a.attribute == null || a.type == null || !(a.attribute instanceof Attribute.TypeCompound typeCompound)) {
             // Create a new TypeCompound
             List<Pair<MethodSymbol,Attribute>> elems =
                     attributeAnnotationValues(a, expectedAnnotationType, env);
@@ -458,7 +454,7 @@ public class Annotate {
             return tc;
         } else {
             // Use an existing TypeCompound
-            return (Attribute.TypeCompound)a.attribute;
+            return typeCompound;
         }
     }
 
@@ -911,12 +907,12 @@ public class Annotate {
             log.error(pos, Errors.InvalidRepeatableAnnotation(annoDecl));
             return null;
         }
-        if (!(p.snd instanceof Attribute.Class)) { // check that the value of "value" is an Attribute.Class
+        if (!(p.snd instanceof Attribute.Class attributeClass)) { // check that the value of "value" is an Attribute.Class
             log.error(pos, Errors.InvalidRepeatableAnnotation(annoDecl));
             return null;
         }
 
-        return ((Attribute.Class)p.snd).getValue();
+        return attributeClass.getValue();
     }
 
     /* Validate that the suggested targetContainerType Type is a valid

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/ArgumentAttr.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2021, 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
@@ -751,12 +751,9 @@ public class ArgumentAttr extends JCTree.Visitor {
 
         @Override
         public boolean equals(Object obj) {
-            if (obj instanceof UniquePos) {
+            return (obj instanceof UniquePos uniquePos)
-                UniquePos that = (UniquePos)obj;
+                    && pos == uniquePos.pos
-                return pos == that.pos && source == that.source;
+                    && source == uniquePos.source;
-            } else {
-                return false;
-            }
         }
 
         @Override

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java

@@ -430,8 +430,8 @@ public class Attr extends JCTree.Visitor {
         } catch (BreakAttr b) {
             return b.env;
         } catch (AssertionError ae) {
-            if (ae.getCause() instanceof BreakAttr) {
+            if (ae.getCause() instanceof BreakAttr breakAttr) {
-                return ((BreakAttr)(ae.getCause())).env;
+                return breakAttr.env;
             } else {
                 throw ae;
             }

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/AttrRecover.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 2021, 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
@@ -243,8 +243,8 @@ public class AttrRecover {
                     break;
             }
             for (Object a : d.getArgs()) {
-                if (a instanceof JCDiagnostic) {
+                if (a instanceof JCDiagnostic diagnostic) {
-                    diags = diags.prepend((JCDiagnostic) a);
+                    diags = diags.prepend(diagnostic);
                 }
             }
         }

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Check.java

@@ -317,12 +317,12 @@ public class Check {
     Type typeTagError(DiagnosticPosition pos, JCDiagnostic required, Object found) {
         // this error used to be raised by the parser,
         // but has been delayed to this point:
-        if (found instanceof Type && ((Type)found).hasTag(VOID)) {
+        if (found instanceof Type type && type.hasTag(VOID)) {
             log.error(pos, Errors.IllegalStartOfType);
             return syms.errType;
         }
         log.error(pos, Errors.TypeFoundReq(found, required));
-        return types.createErrorType(found instanceof Type ? (Type)found : syms.errType);
+        return types.createErrorType(found instanceof Type type ? type : syms.errType);
     }
 
     /** Report an error that symbol cannot be referenced before super
@@ -1337,8 +1337,7 @@ public class Check {
             @Override
             public void visitVarDef(JCVariableDecl tree) {
                 if ((tree.mods.flags & ENUM) != 0) {
-                    if (tree.init instanceof JCNewClass &&
+                    if (tree.init instanceof JCNewClass newClass && newClass.def != null) {
-                        ((JCNewClass) tree.init).def != null) {
                         specialized = true;
                     }
                 }
@@ -3168,11 +3167,10 @@ public class Check {
         } else {
             containerTargets = new HashSet<>();
             for (Attribute app : containerTarget.values) {
-                if (!(app instanceof Attribute.Enum)) {
+                if (!(app instanceof Attribute.Enum attributeEnum)) {
                     continue; // recovery
                 }
-                Attribute.Enum e = (Attribute.Enum)app;
+                containerTargets.add(attributeEnum.value.name);
-                containerTargets.add(e.value.name);
             }
         }
 
@@ -3183,11 +3181,10 @@ public class Check {
         } else {
             containedTargets = new HashSet<>();
             for (Attribute app : containedTarget.values) {
-                if (!(app instanceof Attribute.Enum)) {
+                if (!(app instanceof Attribute.Enum attributeEnum)) {
                     continue; // recovery
                 }
-                Attribute.Enum e = (Attribute.Enum)app;
+                containedTargets.add(attributeEnum.value.name);
-                containedTargets.add(e.value.name);
             }
         }
 
@@ -3311,11 +3308,10 @@ public class Check {
             targets = new Name[arr.values.length];
             for (int i=0; i<arr.values.length; ++i) {
                 Attribute app = arr.values[i];
-                if (!(app instanceof Attribute.Enum)) {
+                if (!(app instanceof Attribute.Enum attributeEnum)) {
                     return new Name[0];
                 }
-                Attribute.Enum e = (Attribute.Enum) app;
+                targets[i] = attributeEnum.value.name;
-                targets[i] = e.value.name;
             }
         }
         return targets;
@@ -3343,12 +3339,11 @@ public class Check {
             targets = new Name[arr.values.length];
             for (int i=0; i<arr.values.length; ++i) {
                 Attribute app = arr.values[i];
-                if (!(app instanceof Attribute.Enum)) {
+                if (!(app instanceof Attribute.Enum attributeEnum)) {
                     // recovery
                     return Optional.empty();
                 }
-                Attribute.Enum e = (Attribute.Enum) app;
+                targets[i] = attributeEnum.value.name;
-                targets[i] = e.value.name;
             }
         }
         for (Name target : targets) {
@@ -3412,8 +3407,7 @@ public class Check {
         Attribute.Compound atTarget = s.getAnnotationTypeMetadata().getTarget();
         if (atTarget == null) return null; // ok, is applicable
         Attribute atValue = atTarget.member(names.value);
-        if (!(atValue instanceof Attribute.Array)) return null; // error recovery
+        return (atValue instanceof Attribute.Array attributeArray) ? attributeArray : null;
-        return (Attribute.Array) atValue;
     }
 
     public final Name[] dfltTargetMeta;

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java

@@ -749,11 +749,10 @@ public class Flow {
             ListBuffer<PendingExit> prevPendingExits = pendingExits;
             pendingExits = new ListBuffer<>();
             for (JCTree resource : tree.resources) {
-                if (resource instanceof JCVariableDecl) {
+                if (resource instanceof JCVariableDecl variableDecl) {
-                    JCVariableDecl vdecl = (JCVariableDecl) resource;
+                    visitVarDef(variableDecl);
-                    visitVarDef(vdecl);
+                } else if (resource instanceof JCExpression expression) {
-                } else if (resource instanceof JCExpression) {
+                    scan(expression);
-                    scan((JCExpression) resource);
                 } else {
                     throw new AssertionError(tree);  // parser error
                 }
@@ -943,8 +942,7 @@ public class Flow {
             for (PendingExit exit = pendingExits.next();
                  exit != null;
                  exit = pendingExits.next()) {
-                if (exit instanceof ThrownPendingExit) {
+                if (exit instanceof ThrownPendingExit thrownExit) {
-                    ThrownPendingExit thrownExit = (ThrownPendingExit) exit;
                     if (classDef != null &&
                         classDef.pos == exit.tree.pos) {
                         log.error(exit.tree.pos(),
@@ -1222,11 +1220,10 @@ public class Flow {
             ListBuffer<PendingExit> prevPendingExits = pendingExits;
             pendingExits = new ListBuffer<>();
             for (JCTree resource : tree.resources) {
-                if (resource instanceof JCVariableDecl) {
+                if (resource instanceof JCVariableDecl variableDecl) {
-                    JCVariableDecl vdecl = (JCVariableDecl) resource;
+                    visitVarDef(variableDecl);
-                    visitVarDef(vdecl);
+                } else if (resource instanceof JCExpression expression) {
-                } else if (resource instanceof JCExpression) {
+                    scan(expression);
-                    scan((JCExpression) resource);
                 } else {
                     throw new AssertionError(tree);  // parser error
                 }
@@ -2432,13 +2429,12 @@ public class Flow {
             final Bits initsTry = new Bits(inits);
             uninitsTry.assign(uninits);
             for (JCTree resource : tree.resources) {
-                if (resource instanceof JCVariableDecl) {
+                if (resource instanceof JCVariableDecl variableDecl) {
-                    JCVariableDecl vdecl = (JCVariableDecl) resource;
+                    visitVarDef(variableDecl);
-                    visitVarDef(vdecl);
+                    unrefdResources.enter(variableDecl.sym);
-                    unrefdResources.enter(vdecl.sym);
+                    resourceVarDecls.append(variableDecl);
-                    resourceVarDecls.append(vdecl);
+                } else if (resource instanceof JCExpression expression) {
-                } else if (resource instanceof JCExpression) {
+                    scanExpr(expression);
-                    scanExpr((JCExpression) resource);
                 } else {
                     throw new AssertionError(tree);  // parser error
                 }
@@ -2495,9 +2491,9 @@ public class Flow {
                     // versus finally!
                     while (exits.nonEmpty()) {
                         PendingExit exit = exits.next();
-                        if (exit instanceof AssignPendingExit) {
+                        if (exit instanceof AssignPendingExit assignPendingExit) {
-                            ((AssignPendingExit) exit).exit_inits.orSet(inits);
+                            assignPendingExit.exit_inits.orSet(inits);
-                            ((AssignPendingExit) exit).exit_uninits.andSet(uninits);
+                            assignPendingExit.exit_uninits.andSet(uninits);
                         }
                         pendingExits.append(exit);
                     }

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Infer.java

@@ -1202,14 +1202,10 @@ public class Infer {
 
         @Override
         public boolean equals(Object o) {
-            if (!(o instanceof IncorporationBinaryOp)) {
+            return (o instanceof IncorporationBinaryOp incorporationBinaryOp)
-                return false;
+                    && opKind == incorporationBinaryOp.opKind
-            } else {
+                    && types.isSameType(op1, incorporationBinaryOp.op1)
-                IncorporationBinaryOp that = (IncorporationBinaryOp)o;
+                    && types.isSameType(op2, incorporationBinaryOp.op2);
-                return opKind == that.opKind &&
-                        types.isSameType(op1, that.op1) &&
-                        types.isSameType(op2, that.op2);
-            }
         }
 
         @Override

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/LambdaToMethod.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2010, 2021, 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
@@ -197,12 +197,9 @@ public class LambdaToMethod extends TreeTranslator {
 
         @Override
         public boolean equals(Object o) {
-            if (!(o instanceof DedupedLambda)) {
+            return (o instanceof DedupedLambda dedupedLambda)
-                return false;
+                    && types.isSameType(symbol.asType(), dedupedLambda.symbol.asType())
-            }
+                    && new TreeDiffer(symbol.params(), dedupedLambda.symbol.params()).scan(tree, dedupedLambda.tree);
-            DedupedLambda that = (DedupedLambda) o;
-            return types.isSameType(symbol.asType(), that.symbol.asType())
-                    && new TreeDiffer(symbol.params(), that.symbol.params()).scan(tree, that.tree);
         }
     }
 
@@ -1558,12 +1555,9 @@ public class LambdaToMethod extends TreeTranslator {
         @Override
         public void visitVarDef(JCVariableDecl tree) {
             TranslationContext<?> context = context();
-            LambdaTranslationContext ltc = (context != null && context instanceof LambdaTranslationContext)?
+            if (context != null && context instanceof LambdaTranslationContext lambdaContext) {
-                    (LambdaTranslationContext)context :
-                    null;
-            if (ltc != null) {
                 if (frameStack.head.tree.hasTag(LAMBDA)) {
-                    ltc.addSymbol(tree.sym, LOCAL_VAR);
+                    lambdaContext.addSymbol(tree.sym, LOCAL_VAR);
                 }
                 // Check for type variables (including as type arguments).
                 // If they occur within class nested in a lambda, mark for erasure
@@ -1767,10 +1761,7 @@ public class LambdaToMethod extends TreeTranslator {
          *  set of nodes that select `this' (qualified this)
          */
         private boolean lambdaFieldAccessFilter(JCFieldAccess fAccess) {
-            LambdaTranslationContext lambdaContext =
+            return (context instanceof LambdaTranslationContext lambdaContext)
-                    context instanceof LambdaTranslationContext ?
-                            (LambdaTranslationContext) context : null;
-            return lambdaContext != null
                     && !fAccess.sym.isStatic()
                     && fAccess.name == names._this
                     && (fAccess.sym.owner.kind == TYP)

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Lower.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2021, 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
@@ -1603,11 +1603,10 @@ public class Lower extends TreeTranslator {
         JCTree resource = resources.head;
         JCExpression resourceUse;
         boolean resourceNonNull;
-        if (resource instanceof JCVariableDecl) {
+        if (resource instanceof JCVariableDecl variableDecl) {
-            JCVariableDecl var = (JCVariableDecl) resource;
+            resourceUse = make.Ident(variableDecl.sym).setType(resource.type);
-            resourceUse = make.Ident(var.sym).setType(resource.type);
+            resourceNonNull = variableDecl.init != null && TreeInfo.skipParens(variableDecl.init).hasTag(NEWCLASS);
-            resourceNonNull = var.init != null && TreeInfo.skipParens(var.init).hasTag(NEWCLASS);
+            stats.add(variableDecl);
-            stats.add(var);
         } else {
             Assert.check(resource instanceof JCExpression);
             VarSymbol syntheticTwrVar =

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Resolve.java

@@ -1599,12 +1599,12 @@ public class Resolve {
                 case ABSENT_MTH:
                     return new InapplicableSymbolError(currentResolutionContext);
                 case HIDDEN:
-                    if (bestSoFar instanceof AccessError) {
+                    if (bestSoFar instanceof AccessError accessError) {
                         // Add the JCDiagnostic of previous AccessError to the currentResolutionContext
                         // and construct InapplicableSymbolsError.
                         // Intentionally fallthrough.
-                        currentResolutionContext.addInapplicableCandidate(((AccessError) bestSoFar).sym,
+                        currentResolutionContext.addInapplicableCandidate(accessError.sym,
-                                ((AccessError) bestSoFar).getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT, null, null, site, null, argtypes, typeargtypes));
+                                accessError.getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT, null, null, site, null, argtypes, typeargtypes));
                     } else {
                         return bestSoFar;
                     }
@@ -1631,11 +1631,11 @@ public class Resolve {
             } else if (bestSoFar.kind == WRONG_MTHS) {
                 // Add the JCDiagnostic of current AccessError to the currentResolutionContext
                 currentResolutionContext.addInapplicableCandidate(sym, curDiagnostic);
-            } else if (bestSoFar.kind == HIDDEN && bestSoFar instanceof AccessError) {
+            } else if (bestSoFar.kind == HIDDEN && bestSoFar instanceof AccessError accessError) {
                 // Add the JCDiagnostics of previous and current AccessError to the currentResolutionContext
                 // and construct InapplicableSymbolsError.
-                currentResolutionContext.addInapplicableCandidate(((AccessError) bestSoFar).sym,
+                currentResolutionContext.addInapplicableCandidate(accessError.sym,
-                        ((AccessError) bestSoFar).getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT, null, null, site, null, argtypes, typeargtypes));
+                        accessError.getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT, null, null, site, null, argtypes, typeargtypes));
                 currentResolutionContext.addInapplicableCandidate(sym, curDiagnostic);
                 bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
             }
@@ -4841,10 +4841,10 @@ public class Resolve {
             }
 
             BiPredicate<Object, List<Type>> containsPredicate = (o, ts) -> {
-                if (o instanceof Type) {
+                if (o instanceof Type type) {
-                    return ((Type)o).containsAny(ts);
+                    return type.containsAny(ts);
-                } else if (o instanceof JCDiagnostic) {
+                } else if (o instanceof JCDiagnostic diagnostic) {
-                    return containsAny((JCDiagnostic)o, ts);
+                    return containsAny(diagnostic, ts);
                 } else {
                     return false;
                 }

src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/ClassReader.java

@@ -829,7 +829,7 @@ public class ClassReader {
                            // ignore ConstantValue attribute if type is not primitive or String
                            return;
                     }
-                    if (v instanceof Integer && !var.type.getTag().checkRange((Integer) v)) {
+                    if (v instanceof Integer intVal && !var.type.getTag().checkRange(intVal)) {
                         throw badClassFile("bad.constant.range", v, var, var.type);
                     }
                     var.setData(v);
@@ -1429,9 +1429,8 @@ public class ClassReader {
             else if (proxy.type.tsym.flatName() == syms.profileType.tsym.flatName()) {
                 if (profile != Profile.DEFAULT) {
                     for (Pair<Name, Attribute> v : proxy.values) {
-                        if (v.fst == names.value && v.snd instanceof Attribute.Constant) {
+                        if (v.fst == names.value && v.snd instanceof Attribute.Constant constant) {
-                            Attribute.Constant c = (Attribute.Constant)v.snd;
+                            if (constant.type == syms.intType && ((Integer) constant.value) > profile.value) {
-                            if (c.type == syms.intType && ((Integer)c.value) > profile.value) {
                                 sym.flags_field |= NOT_IN_PROFILE;
                             }
                         }
@@ -1460,9 +1459,8 @@ public class ClassReader {
     //where:
         private void setFlagIfAttributeTrue(CompoundAnnotationProxy proxy, Symbol sym, Name attribute, long flag) {
             for (Pair<Name, Attribute> v : proxy.values) {
-                if (v.fst == attribute && v.snd instanceof Attribute.Constant) {
+                if (v.fst == attribute && v.snd instanceof Attribute.Constant constant) {
-                    Attribute.Constant c = (Attribute.Constant)v.snd;
+                    if (constant.type == syms.booleanType && ((Integer) constant.value) != 0) {
-                    if (c.type == syms.booleanType && ((Integer)c.value) != 0) {
                         sym.flags_field |= flag;
                     }
                 }
@@ -2051,12 +2049,12 @@ public class ClassReader {
         }
 
         Type resolvePossibleProxyType(Type t) {
-            if (t instanceof ProxyType) {
+            if (t instanceof ProxyType proxyType) {
                 Assert.check(requestingOwner.owner.kind == MDL);
                 ModuleSymbol prevCurrentModule = currentModule;
                 currentModule = (ModuleSymbol) requestingOwner.owner;
                 try {
-                    return ((ProxyType) t).resolve();
+                    return proxyType.resolve();
                 } finally {
                     currentModule = prevCurrentModule;
                 }
@@ -2125,9 +2123,8 @@ public class ClassReader {
                     if (attr.type.tsym == syms.deprecatedType.tsym) {
                         sym.flags_field |= (DEPRECATED | DEPRECATED_ANNOTATION);
                         Attribute forRemoval = attr.member(names.forRemoval);
-                        if (forRemoval instanceof Attribute.Constant) {
+                        if (forRemoval instanceof Attribute.Constant constant) {
-                            Attribute.Constant c = (Attribute.Constant) forRemoval;
+                            if (constant.type == syms.booleanType && ((Integer) constant.value) != 0) {
-                            if (c.type == syms.booleanType && ((Integer) c.value) != 0) {
                                 sym.flags_field |= DEPRECATED_REMOVAL;
                             }
                         }
@@ -2811,12 +2808,8 @@ public class ClassReader {
         public boolean equals(Object other) {
             if (this == other)
                 return true;
-
+            return (other instanceof SourceFileObject sourceFileObject)
-            if (!(other instanceof SourceFileObject))
+                    && name.equals(sourceFileObject.name);
-                return false;
-
-            SourceFileObject o = (SourceFileObject) other;
-            return name.equals(o.name);
         }
 
         @Override

src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Gen.java

@@ -530,8 +530,8 @@ public class Gen extends JCTree.Visitor {
     private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
         if (nerrs != 0 || // only complain about a long string once
             constValue == null ||
-            !(constValue instanceof String) ||
+            !(constValue instanceof String str) ||
-            ((String)constValue).length() < PoolWriter.MAX_STRING_LENGTH)
+            str.length() < PoolWriter.MAX_STRING_LENGTH)
             return;
         log.error(pos, Errors.LimitString);
         nerrs++;
@@ -824,8 +824,8 @@ public class Gen extends JCTree.Visitor {
 
         @Override
         public void visitIdent(JCIdent tree) {
-            if (tree.sym.owner instanceof ClassSymbol) {
+            if (tree.sym.owner instanceof ClassSymbol classSymbol) {
-                poolWriter.putClass((ClassSymbol)tree.sym.owner);
+                poolWriter.putClass(classSymbol);
             }
         }
 
@@ -888,8 +888,8 @@ public class Gen extends JCTree.Visitor {
 
     public boolean isConstantDynamic(Symbol sym) {
         return sym.kind == VAR &&
-                sym instanceof DynamicVarSymbol &&
+                sym instanceof DynamicVarSymbol dynamicVarSymbol &&
-                ((DynamicVarSymbol)sym).isDynamic();
+                dynamicVarSymbol.isDynamic();
     }
 
     /** Derived visitor method: generate code for a list of method arguments.
@@ -1667,9 +1667,8 @@ public class Gen extends JCTree.Visitor {
 
             while(alts != null && alts.head != null) {
                 JCExpression alt = alts.head;
-                if (alt instanceof JCAnnotatedType) {
+                if (alt instanceof JCAnnotatedType annotatedType) {
-                    JCAnnotatedType a = (JCAnnotatedType)alt;
+                    res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt));
-                    res = res.prepend(new Pair<>(annotate.fromAnnotations(a.annotations), alt));
                 } else {
                     res = res.prepend(new Pair<>(List.nil(), alt));
                 }
@@ -2032,13 +2031,13 @@ public class Gen extends JCTree.Visitor {
             // int variable we can use an incr instruction instead of
             // proceeding further.
             if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
-                l instanceof LocalItem &&
+                l instanceof LocalItem localItem &&
                 tree.lhs.type.getTag().isSubRangeOf(INT) &&
                 tree.rhs.type.getTag().isSubRangeOf(INT) &&
                 tree.rhs.type.constValue() != null) {
                 int ival = ((Number) tree.rhs.type.constValue()).intValue();
                 if (tree.hasTag(MINUS_ASG)) ival = -ival;
-                ((LocalItem)l).incr(ival);
+                localItem.incr(ival);
                 result = l;
                 return;
             }
@@ -2073,9 +2072,9 @@ public class Gen extends JCTree.Visitor {
                 break;
             case PREINC: case PREDEC:
                 od.duplicate();
-                if (od instanceof LocalItem &&
+                if (od instanceof LocalItem localItem &&
                     (operator.opcode == iadd || operator.opcode == isub)) {
-                    ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1);
+                    localItem.incr(tree.hasTag(PREINC) ? 1 : -1);
                     result = od;
                 } else {
                     od.load();
@@ -2091,10 +2090,10 @@ public class Gen extends JCTree.Visitor {
                 break;
             case POSTINC: case POSTDEC:
                 od.duplicate();
-                if (od instanceof LocalItem &&
+                if (od instanceof LocalItem localItem &&
                     (operator.opcode == iadd || operator.opcode == isub)) {
                     Item res = od.load();
-                    ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1);
+                    localItem.incr(tree.hasTag(POSTINC) ? 1 : -1);
                     result = res;
                 } else {
                     Item res = od.load();
@@ -2178,8 +2177,8 @@ public class Gen extends JCTree.Visitor {
             MethodType optype = (MethodType)operator.type;
             int opcode = operator.opcode;
             if (opcode >= if_icmpeq && opcode <= if_icmple &&
-                rhs.type.constValue() instanceof Number &&
+                    rhs.type.constValue() instanceof Number number &&
-                ((Number) rhs.type.constValue()).intValue() == 0) {
+                    number.intValue() == 0) {
                 opcode = opcode + (ifeq - if_icmpeq);
             } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
                        TreeInfo.isNull(rhs)) {

src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/PoolConstant.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 2021, 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
@@ -187,13 +187,9 @@ public interface PoolConstant {
 
             @Override
             public boolean equals(Object obj) {
-                if (obj instanceof BsmKey) {
+                return (obj instanceof BsmKey key)
-                    BsmKey other = (BsmKey)obj;
+                        && Objects.equals(bsmKey, key.bsmKey)
-                    return Objects.equals(bsmKey, other.bsmKey) &&
+                        && Objects.equals(staticArgKeys, key.staticArgKeys);
-                            Objects.equals(staticArgKeys, other.staticArgKeys);
-                } else {
-                    return false;
-                }
             }
         }
     }

src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/PoolWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 2021, 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
@@ -163,16 +163,16 @@ public class PoolWriter {
      * double and String.
      */
     int putConstant(Object o) {
-        if (o instanceof Integer) {
+        if (o instanceof Integer intVal) {
-            return putConstant(LoadableConstant.Int((int)o));
+            return putConstant(LoadableConstant.Int(intVal));
-        } else if (o instanceof Float) {
+        } else if (o instanceof Float floatVal) {
-            return putConstant(LoadableConstant.Float((float)o));
+            return putConstant(LoadableConstant.Float(floatVal));
-        } else if (o instanceof Long) {
+        } else if (o instanceof Long longVal) {
-            return putConstant(LoadableConstant.Long((long)o));
+            return putConstant(LoadableConstant.Long(longVal));
-        } else if (o instanceof Double) {
+        } else if (o instanceof Double doubleVal) {
-            return putConstant(LoadableConstant.Double((double)o));
+            return putConstant(LoadableConstant.Double(doubleVal));
-        } else if (o instanceof String) {
+        } else if (o instanceof String strVal) {
-            return putConstant(LoadableConstant.String((String)o));
+            return putConstant(LoadableConstant.String(strVal));
         } else {
             throw new AssertionError("unexpected constant: " + o);
         }

src/jdk.compiler/share/classes/com/sun/tools/javac/parser/JavacParser.java

@@ -3584,8 +3584,8 @@ public class JavacParser implements Parser {
                     }
                 }
                 JCTree def = typeDeclaration(mods, docComment);
-                if (def instanceof JCExpressionStatement)
+                if (def instanceof JCExpressionStatement statement)
-                    def = ((JCExpressionStatement)def).expr;
+                    def = statement.expr;
                 defs.append(def);
                 if (def instanceof JCClassDecl)
                     checkForImports = false;

src/jdk.compiler/share/classes/com/sun/tools/javac/parser/ScannerFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2021, 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
@@ -74,12 +74,11 @@ public class ScannerFactory {
     }
 
     public Scanner newScanner(CharSequence input, boolean keepDocComments) {
-        if (input instanceof CharBuffer) {
+        if (input instanceof CharBuffer charBuffer) {
-            CharBuffer buf = (CharBuffer) input;
             if (keepDocComments)
-                return new Scanner(this, new JavadocTokenizer(this, buf));
+                return new Scanner(this, new JavadocTokenizer(this, charBuffer));
             else
-                return new Scanner(this, buf);
+                return new Scanner(this, charBuffer);
         } else {
             char[] array = input.toString().toCharArray();
             return newScanner(array, array.length, keepDocComments);

src/jdk.compiler/share/classes/com/sun/tools/javac/processing/JavacFiler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2021, 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
@@ -542,18 +542,17 @@ public class JavacFiler implements Filer, Closeable {
                                          relativeName.toString(), null);
         checkFileReopening(fileObject, true);
 
-        if (fileObject instanceof JavaFileObject)
+        if (fileObject instanceof JavaFileObject javaFileObject)
-            return new FilerOutputJavaFileObject(msym, null, (JavaFileObject)fileObject);
+            return new FilerOutputJavaFileObject(msym, null, javaFileObject);
         else
             return new FilerOutputFileObject(msym, null, fileObject);
     }
 
     private void locationCheck(JavaFileManager.Location location) {
-        if (location instanceof StandardLocation) {
+        if (location instanceof StandardLocation standardLocation) {
-            StandardLocation stdLoc = (StandardLocation) location;
+            if (!standardLocation.isOutputLocation())
-            if (!stdLoc.isOutputLocation())
                 throw new IllegalArgumentException("Resource creation not supported in location " +
-                                                   stdLoc);
+                                                    standardLocation);
         }
     }
 
@@ -889,9 +888,8 @@ public class JavacFiler implements Filer, Closeable {
          * subject to annotation processing.
          */
         if ((typeName != null)) {
-            if (!(fileObject instanceof JavaFileObject))
+            if (!(fileObject instanceof JavaFileObject javaFileObject))
                 throw new AssertionError("JavaFileObject not found for " + fileObject);
-            JavaFileObject javaFileObject = (JavaFileObject)fileObject;
             switch(javaFileObject.getKind()) {
             case SOURCE:
                 generatedSourceNames.add(typeName);

src/jdk.compiler/share/classes/com/sun/tools/javac/processing/JavacProcessingEnvironment.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2021, 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
@@ -286,8 +286,8 @@ public class JavacProcessingEnvironment implements ProcessingEnvironment, Closea
                 if (options.isSet("accessInternalAPI"))
                     ModuleHelper.addExports(getClass().getModule(), processorClassLoader.getUnnamedModule());
 
-                if (processorClassLoader != null && processorClassLoader instanceof Closeable) {
+                if (processorClassLoader != null && processorClassLoader instanceof Closeable closeable) {
-                    compiler.closeables = compiler.closeables.prepend((Closeable) processorClassLoader);
+                    compiler.closeables = compiler.closeables.prepend(closeable);
                 }
             }
         } catch (SecurityException e) {
@@ -376,8 +376,7 @@ public class JavacProcessingEnvironment implements ProcessingEnvironment, Closea
      * @param e   If non-null, pass this exception to Abort
      */
     private Iterator<Processor> handleServiceLoaderUnavailability(String key, Exception e) {
-        if (fileManager instanceof JavacFileManager) {
+        if (fileManager instanceof JavacFileManager standardFileManager) {
-            StandardJavaFileManager standardFileManager = (JavacFileManager) fileManager;
             Iterable<? extends Path> workingPath = fileManager.hasLocation(ANNOTATION_PROCESSOR_PATH)
                 ? standardFileManager.getLocationAsPaths(ANNOTATION_PROCESSOR_PATH)
                 : standardFileManager.getLocationAsPaths(CLASS_PATH);
@@ -880,8 +879,8 @@ public class JavacProcessingEnvironment implements ProcessingEnvironment, Closea
          */
         public void close() {
             if (processorIterator != null &&
-                processorIterator instanceof ServiceIterator) {
+                processorIterator instanceof ServiceIterator serviceIterator) {
-                ((ServiceIterator) processorIterator).close();
+                serviceIterator.close();
             }
         }
     }