org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/InstanceOfExpression.java - jdt/eclipse.jdt.core - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2020 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Stephan Herrmann - Contribution for
  *								bug 383368 - [compiler][null] syntactic null analysis for field references
  *								Bug 392238 - [1.8][compiler][null] Detect semantically invalid null type annotations
  *								Bug 416307 - [1.8][compiler][null] subclass with type parameter substitution confuses null checking
  *								Bug 392099 - [1.8][compiler][null] Apply null annotation on types for null analysis
  *								Bug 417295 - [1.8[[null] Massage type annotated null analysis to gel well with deep encoded type bindings.
  *								Bug 392238 - [1.8][compiler][null] Detect semantically invalid null type annotations
  *								Bug 435570 - [1.8][null] @NonNullByDefault illegally tries to affect "throws E"
  *								Bug 466713 - Null Annotations: NullPointerException using <int @Nullable []> as Type Param
  *        Andy Clement - Contributions for
  *                          Bug 383624 - [1.8][compiler] Revive code generation support for type annotations (from Olivier's work)
  *******************************************************************************/
 package org.eclipse.jdt.internal.compiler.ast;

 import org.eclipse.jdt.internal.compiler.ASTVisitor;
 import org.eclipse.jdt.internal.compiler.ast.TypeReference.AnnotationPosition;
 import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
 import org.eclipse.jdt.internal.compiler.codegen.*;
 import org.eclipse.jdt.internal.compiler.flow.*;
 import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
 import org.eclipse.jdt.internal.compiler.impl.Constant;
 import org.eclipse.jdt.internal.compiler.impl.IrritantSet;
 import org.eclipse.jdt.internal.compiler.lookup.*;

 public class InstanceOfExpression extends OperatorExpression {

 	public Expression expression;
 	public TypeReference type;
 	public LocalDeclaration elementVariable;
 	static final char[] SECRET_INSTANCEOF_PATTERN_EXPRESSION_VALUE = " instanceOfPatternExpressionValue".toCharArray(); //$NON-NLS-1$

 	public LocalVariableBinding secretInstanceOfPatternExpressionValue = null;

 public InstanceOfExpression(Expression expression, TypeReference type) {
 	this.expression = expression;
 	this.type = type;
 	type.bits |= IgnoreRawTypeCheck; // https://bugs.eclipse.org/bugs/show_bug.cgi?id=282141
 	this.bits |= INSTANCEOF << OperatorSHIFT;
 	this.sourceStart = expression.sourceStart;
 	this.sourceEnd = type.sourceEnd;
 }
 public InstanceOfExpression(Expression expression, LocalDeclaration local) {
 	this.expression = expression;
 	this.elementVariable = local;
 	this.type = this.elementVariable.type;
 	this.bits |= INSTANCEOF << OperatorSHIFT;
 	this.elementVariable.sourceStart = local.sourceStart;
 	this.elementVariable.sourceEnd = local.sourceEnd;
 	this.sourceStart = expression.sourceStart;
 	this.sourceEnd = local.declarationSourceEnd;
 }

 @Override
 public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) {
 	LocalVariableBinding local = this.expression.localVariableBinding();
 	FlowInfo initsWhenTrue = null;
 	if (local != null && (local.type.tagBits & TagBits.IsBaseType) == 0) {
 		flowInfo = this.expression.analyseCode(currentScope, flowContext, flowInfo).
 			unconditionalInits();
 		initsWhenTrue = flowInfo.copy();
 		initsWhenTrue.markAsComparedEqualToNonNull(local);
 		flowContext.recordUsingNullReference(currentScope, local,
 				this.expression, FlowContext.CAN_ONLY_NULL | FlowContext.IN_INSTANCEOF, flowInfo);
 		// no impact upon enclosing try context
 		flowInfo =  FlowInfo.conditional(initsWhenTrue, flowInfo.copy());
 	} else if (this.expression instanceof Reference) {
 		if (currentScope.compilerOptions().enableSyntacticNullAnalysisForFields) {
 			FieldBinding field = ((Reference)this.expression).lastFieldBinding();
 			if (field != null && (field.type.tagBits & TagBits.IsBaseType) == 0) {
 				flowContext.recordNullCheckedFieldReference((Reference) this.expression, 1);
 			}
 		}
 	}
 	if (initsWhenTrue == null) {
 		flowInfo = this.expression.analyseCode(currentScope, flowContext, flowInfo).
 				unconditionalInits();
 		if (this.elementVariable != null) {
 			initsWhenTrue = flowInfo.copy();
 		}
 	}
 	if (this.elementVariable != null) {
 		if (this.elementVariable.duplicateCheckObligation != null) {
 			this.elementVariable.duplicateCheckObligation.accept(flowInfo);
 		}
 		initsWhenTrue.markAsDefinitelyAssigned(this.elementVariable.binding);
 	}
 	return (initsWhenTrue == null) ? flowInfo :
 			FlowInfo.conditional(initsWhenTrue, flowInfo.copy());
 }
 /**
  * Code generation for instanceOfExpression
  *
  * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
  * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
  * @param valueRequired boolean
 */
 @Override
 public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
 	addPatternVariables(currentScope, codeStream);

 	int pc = codeStream.position;

 	if (this.elementVariable != null) {
 		addAssignment(currentScope, codeStream, this.secretInstanceOfPatternExpressionValue);
 		codeStream.load(this.secretInstanceOfPatternExpressionValue);
 	} else {
 		this.expression.generateCode(currentScope, codeStream, true);
 	}

 	codeStream.instance_of(this.type, this.type.resolvedType);
 	if (this.elementVariable != null) {
 		BranchLabel actionLabel = new BranchLabel(codeStream);
 		codeStream.dup();
 		codeStream.ifeq(actionLabel);
 		codeStream.load(this.secretInstanceOfPatternExpressionValue);
 		codeStream.removeVariable(this.secretInstanceOfPatternExpressionValue);
 		codeStream.checkcast(this.type, this.type.resolvedType, codeStream.position);
 		this.elementVariable.binding.recordInitializationStartPC(codeStream.position);
 		codeStream.store(this.elementVariable.binding, false);
 		codeStream.removeVariable(this.elementVariable.binding);
 		codeStream.recordPositionsFrom(codeStream.position, this.sourceEnd);
 		actionLabel.place();
 	}
 	if (valueRequired) {
 		codeStream.generateImplicitConversion(this.implicitConversion);
 	} else {
 		codeStream.pop();
 	}
 	codeStream.recordPositionsFrom(pc, this.sourceStart);
 }
 @Override
 public void generateOptimizedBoolean(BlockScope currentScope, CodeStream codeStream, BranchLabel trueLabel, BranchLabel falseLabel, boolean valueRequired) {
 	// a label valued to nil means: by default we fall through the case...
 	// both nil means we leave the value on the stack

 	if (this.elementVariable == null) {
 		super.generateOptimizedBoolean(currentScope, codeStream, trueLabel, falseLabel, valueRequired);
 		return;
 	}
 	Constant cst = optimizedBooleanConstant();
 	addPatternVariables(currentScope, codeStream);

 	int pc = codeStream.position;

 	addAssignment(currentScope, codeStream, this.secretInstanceOfPatternExpressionValue);
 	codeStream.load(this.secretInstanceOfPatternExpressionValue);

 	BranchLabel nextSibling = falseLabel != null ? falseLabel : new BranchLabel(codeStream);
 	codeStream.instance_of(this.type, this.type.resolvedType);
 	if (this.elementVariable != null) {
 		codeStream.ifeq(nextSibling);
 		codeStream.load(this.secretInstanceOfPatternExpressionValue);
 		codeStream.checkcast(this.type, this.type.resolvedType, codeStream.position);
 		codeStream.dup();
 		codeStream.store(this.elementVariable.binding, false);

 		codeStream.load(this.secretInstanceOfPatternExpressionValue);
 		codeStream.removeVariable(this.secretInstanceOfPatternExpressionValue);
 		codeStream.checkcast(this.type, this.type.resolvedType, codeStream.position);
 	}
 	if (valueRequired && cst == Constant.NotAConstant) {
 		codeStream.generateImplicitConversion(this.implicitConversion);
 	} else {
 		codeStream.pop();
 	}
 	codeStream.recordPositionsFrom(pc, this.sourceStart);


 	if ((cst != Constant.NotAConstant) && (cst.typeID() == TypeIds.T_boolean)) {
 		pc = codeStream.position;
 		if (cst.booleanValue() == true) {
 			// constant == true
 			if (valueRequired) {
 				if (falseLabel == null) {
 					// implicit falling through the FALSE case
 					if (trueLabel != null) {
 						codeStream.goto_(trueLabel);
 					}
 				}
 			}
 		} else {
 			if (valueRequired) {
 				if (falseLabel != null) {
 					// implicit falling through the TRUE case
 					if (trueLabel == null) {
 						codeStream.goto_(falseLabel);
 					}
 				}
 			}
 		}
 		codeStream.recordPositionsFrom(pc, this.sourceStart);
 	} else  {
 		// branching
 		int position = codeStream.position;
 		if (valueRequired) {
 			if (falseLabel == null) {
 				if (trueLabel != null) {
 					// Implicit falling through the FALSE case
 					codeStream.if_acmpeq(trueLabel);
 				}
 			} else {
 				if (trueLabel == null) {
 					// Implicit falling through the TRUE case
 					codeStream.if_acmpne(falseLabel);
 				} else {
 					// No implicit fall through TRUE/FALSE --> should never occur
 				}
 			}
 		}
 		codeStream.recordPositionsFrom(position, this.sourceEnd);
 	}
 	if (nextSibling != falseLabel)
 		nextSibling.place();
 }

 private void addAssignment(BlockScope currentScope, CodeStream codeStream, LocalVariableBinding local) {
 	assert local != null;
 	SingleNameReference lhs = new SingleNameReference(local.name, 0);
 	lhs.binding = local;
 	lhs.bits &= ~ASTNode.RestrictiveFlagMASK; // clear bits
 	lhs.bits |= Binding.LOCAL;
 	lhs.bits |= ASTNode.IsSecretYieldValueUsage;
 	((LocalVariableBinding) lhs.binding).markReferenced(); // TODO : Can be skipped?
 	Assignment assignment = new Assignment(lhs, this.expression, 0);
 	assignment.generateCode(currentScope, codeStream);
 	codeStream.addVariable(this.secretInstanceOfPatternExpressionValue);
 }

 @Override
 public StringBuffer printExpressionNoParenthesis(int indent, StringBuffer output) {
 	this.expression.printExpression(indent, output).append(" instanceof "); //$NON-NLS-1$
 	return this.elementVariable == null ? this.type.print(0, output) : this.elementVariable.printAsExpression(0, output);
 }

 @Override
 public void addPatternVariables(BlockScope currentScope, CodeStream codeStream) {
 	if (this.elementVariable != null) {
 		codeStream.addVisibleLocalVariable(this.elementVariable.binding);
 	}
 }
 public void resolvePatternVariable(BlockScope scope) {
 	if (this.elementVariable != null && this.elementVariable.binding == null) {
 		this.elementVariable.resolve(scope, true);
 		this.elementVariable.binding.modifiers |= ExtraCompilerModifiers.AccPatternVariable;
 		this.elementVariable.binding.useFlag = LocalVariableBinding.USED;
 		// Why cant this be done in the constructor?
 		this.type = this.elementVariable.type;
 	}
 }
 @Override
 public boolean containsPatternVariable() {
 	return this.elementVariable != null;
 }
 private void addSecretInstanceOfPatternExpressionValue(BlockScope scope1) {
 	LocalVariableBinding local =
 			new LocalVariableBinding(
 				InstanceOfExpression.SECRET_INSTANCEOF_PATTERN_EXPRESSION_VALUE,
 				TypeBinding.wellKnownType(scope1, T_JavaLangObject),
 				ClassFileConstants.AccDefault,
 				false);
 	local.setConstant(Constant.NotAConstant);
 	local.useFlag = LocalVariableBinding.USED;
 	local.declaration = new LocalDeclaration(InstanceOfExpression.SECRET_INSTANCEOF_PATTERN_EXPRESSION_VALUE, 0, 0);
 	scope1.addLocalVariable(local);
 	this.secretInstanceOfPatternExpressionValue = local;
 }

 @Override
 public TypeBinding resolveType(BlockScope scope) {
 	this.constant = Constant.NotAConstant;
 	if (this.elementVariable != null)
 	addSecretInstanceOfPatternExpressionValue(scope);
 	resolvePatternVariable(scope);
 	TypeBinding checkedType = this.type.resolveType(scope, true /* check bounds*/);
 	if (this.expression instanceof CastExpression) {
 		((CastExpression) this.expression).setInstanceofType(checkedType); // for cast expression we need to know instanceof type to not tag unnecessary when needed
 	}
 	TypeBinding expressionType = this.expression.resolveType(scope);
 	if (expressionType != null && checkedType != null && this.type.hasNullTypeAnnotation(AnnotationPosition.ANY)) {
 		// don't complain if the entire operation is redundant anyway
 		if (!expressionType.isCompatibleWith(checkedType) || NullAnnotationMatching.analyse(checkedType, expressionType, -1).isAnyMismatch())
 			scope.problemReporter().nullAnnotationUnsupportedLocation(this.type);
 	}
 	if (expressionType == null || checkedType == null)
 		return null;

 	if (this.secretInstanceOfPatternExpressionValue != null && expressionType != TypeBinding.NULL)
 		this.secretInstanceOfPatternExpressionValue.type = expressionType;

 		if (!checkedType.isReifiable()) {
 		CompilerOptions options = scope.compilerOptions();
 		// If preview is disabled, report same as before, even at Java 14
 		if (options.complianceLevel < ClassFileConstants.JDK14 || !options.enablePreviewFeatures) {
 			scope.problemReporter().illegalInstanceOfGenericType(checkedType, this);
 		} else {
 			if (options.isAnyEnabled(IrritantSet.PREVIEW)) {
 				scope.problemReporter().previewFeatureUsed(this.type.sourceStart, this.type.sourceEnd);
 			}
 			if (expressionType != TypeBinding.NULL) {
 				boolean isLegal = checkCastTypesCompatibility(scope, checkedType, expressionType, this.expression, true);
 				if (!isLegal || (this.bits & ASTNode.UnsafeCast) != 0) {
 					scope.problemReporter().unsafeCastInInstanceof(this.expression, checkedType, expressionType);
 				}
 			}
 		}
 	} else if (checkedType.isValidBinding()) {
 		// if not a valid binding, an error has already been reported for unresolved type
 		if ((expressionType != TypeBinding.NULL && expressionType.isBaseType()) // disallow autoboxing
 				|| checkedType.isBaseType()
 				|| !checkCastTypesCompatibility(scope, checkedType, expressionType, null, true)) {
 			scope.problemReporter().notCompatibleTypesError(this, expressionType, checkedType);
 		}
 	}
 	return this.resolvedType = TypeBinding.BOOLEAN;
 }
 @Override
 public boolean checkUnsafeCast(Scope scope, TypeBinding castType, TypeBinding expressionType, TypeBinding match, boolean isNarrowing) {
 	if (!castType.isReifiable())
 		return CastExpression.checkUnsafeCast(this, scope, castType, expressionType, match, isNarrowing);
 	else
 		return super.checkUnsafeCast(scope, castType, expressionType, match, isNarrowing);
 }
 /**
  * @see org.eclipse.jdt.internal.compiler.ast.Expression#tagAsUnnecessaryCast(Scope,TypeBinding)
  */

 @Override
 public void tagAsUnnecessaryCast(Scope scope, TypeBinding castType) {
 	// null is not instanceof Type, recognize direct scenario
 	if (this.expression.resolvedType != TypeBinding.NULL)
 		scope.problemReporter().unnecessaryInstanceof(this, castType);
 }

 @Override
 public void traverse(ASTVisitor visitor, BlockScope scope) {
 	if (visitor.visit(this, scope)) {
 		this.expression.traverse(visitor, scope);
 		if (this.elementVariable != null) {
 			this.elementVariable.traverse(visitor, scope);
 		} else {
 			this.type.traverse(visitor, scope);
 		}
 	}
 	visitor.endVisit(this, scope);
 }
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2020 IBM Corporation and others.
	*
	* This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	* Stephan Herrmann - Contribution for
	* bug 383368 - [compiler][null] syntactic null analysis for field references
	* Bug 392238 - [1.8][compiler][null] Detect semantically invalid null type annotations
	* Bug 416307 - [1.8][compiler][null] subclass with type parameter substitution confuses null checking
	* Bug 392099 - [1.8][compiler][null] Apply null annotation on types for null analysis
	* Bug 417295 - [1.8[[null] Massage type annotated null analysis to gel well with deep encoded type bindings.
	* Bug 392238 - [1.8][compiler][null] Detect semantically invalid null type annotations
	* Bug 435570 - [1.8][null] @NonNullByDefault illegally tries to affect "throws E"
	* Bug 466713 - Null Annotations: NullPointerException using <int @Nullable []> as Type Param
	* Andy Clement - Contributions for
	* Bug 383624 - [1.8][compiler] Revive code generation support for type annotations (from Olivier's work)
	*******************************************************************************/
	package org.eclipse.jdt.internal.compiler.ast;

	import org.eclipse.jdt.internal.compiler.ASTVisitor;
	import org.eclipse.jdt.internal.compiler.ast.TypeReference.AnnotationPosition;
	import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
	import org.eclipse.jdt.internal.compiler.codegen.*;
	import org.eclipse.jdt.internal.compiler.flow.*;
	import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
	import org.eclipse.jdt.internal.compiler.impl.Constant;
	import org.eclipse.jdt.internal.compiler.impl.IrritantSet;
	import org.eclipse.jdt.internal.compiler.lookup.*;

	public class InstanceOfExpression extends OperatorExpression {

	public Expression expression;
	public TypeReference type;
	public LocalDeclaration elementVariable;
	static final char[] SECRET_INSTANCEOF_PATTERN_EXPRESSION_VALUE = " instanceOfPatternExpressionValue".toCharArray(); //$NON-NLS-1$

	public LocalVariableBinding secretInstanceOfPatternExpressionValue = null;

	public InstanceOfExpression(Expression expression, TypeReference type) {
	this.expression = expression;
	this.type = type;
	type.bits \|= IgnoreRawTypeCheck; // https://bugs.eclipse.org/bugs/show_bug.cgi?id=282141
	this.bits \|= INSTANCEOF << OperatorSHIFT;
	this.sourceStart = expression.sourceStart;
	this.sourceEnd = type.sourceEnd;
	}
	public InstanceOfExpression(Expression expression, LocalDeclaration local) {
	this.expression = expression;
	this.elementVariable = local;
	this.type = this.elementVariable.type;
	this.bits \|= INSTANCEOF << OperatorSHIFT;
	this.elementVariable.sourceStart = local.sourceStart;
	this.elementVariable.sourceEnd = local.sourceEnd;
	this.sourceStart = expression.sourceStart;
	this.sourceEnd = local.declarationSourceEnd;
	}

	@Override
	public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) {
	LocalVariableBinding local = this.expression.localVariableBinding();
	FlowInfo initsWhenTrue = null;
	if (local != null && (local.type.tagBits & TagBits.IsBaseType) == 0) {
	flowInfo = this.expression.analyseCode(currentScope, flowContext, flowInfo).
	unconditionalInits();
	initsWhenTrue = flowInfo.copy();
	initsWhenTrue.markAsComparedEqualToNonNull(local);
	flowContext.recordUsingNullReference(currentScope, local,
	this.expression, FlowContext.CAN_ONLY_NULL \| FlowContext.IN_INSTANCEOF, flowInfo);
	// no impact upon enclosing try context
	flowInfo = FlowInfo.conditional(initsWhenTrue, flowInfo.copy());
	} else if (this.expression instanceof Reference) {
	if (currentScope.compilerOptions().enableSyntacticNullAnalysisForFields) {
	FieldBinding field = ((Reference)this.expression).lastFieldBinding();
	if (field != null && (field.type.tagBits & TagBits.IsBaseType) == 0) {
	flowContext.recordNullCheckedFieldReference((Reference) this.expression, 1);
	}
	}
	}
	if (initsWhenTrue == null) {
	flowInfo = this.expression.analyseCode(currentScope, flowContext, flowInfo).
	unconditionalInits();
	if (this.elementVariable != null) {
	initsWhenTrue = flowInfo.copy();
	}
	}
	if (this.elementVariable != null) {
	if (this.elementVariable.duplicateCheckObligation != null) {
	this.elementVariable.duplicateCheckObligation.accept(flowInfo);
	}
	initsWhenTrue.markAsDefinitelyAssigned(this.elementVariable.binding);
	}
	return (initsWhenTrue == null) ? flowInfo :
	FlowInfo.conditional(initsWhenTrue, flowInfo.copy());
	}
	/**
	* Code generation for instanceOfExpression
	*
	* @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
	* @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
	* @param valueRequired boolean
	*/
	@Override
	public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
	addPatternVariables(currentScope, codeStream);

	int pc = codeStream.position;

	if (this.elementVariable != null) {
	addAssignment(currentScope, codeStream, this.secretInstanceOfPatternExpressionValue);
	codeStream.load(this.secretInstanceOfPatternExpressionValue);
	} else {
	this.expression.generateCode(currentScope, codeStream, true);
	}

	codeStream.instance_of(this.type, this.type.resolvedType);
	if (this.elementVariable != null) {
	BranchLabel actionLabel = new BranchLabel(codeStream);
	codeStream.dup();
	codeStream.ifeq(actionLabel);
	codeStream.load(this.secretInstanceOfPatternExpressionValue);
	codeStream.removeVariable(this.secretInstanceOfPatternExpressionValue);
	codeStream.checkcast(this.type, this.type.resolvedType, codeStream.position);
	this.elementVariable.binding.recordInitializationStartPC(codeStream.position);
	codeStream.store(this.elementVariable.binding, false);
	codeStream.removeVariable(this.elementVariable.binding);
	codeStream.recordPositionsFrom(codeStream.position, this.sourceEnd);
	actionLabel.place();
	}
	if (valueRequired) {
	codeStream.generateImplicitConversion(this.implicitConversion);
	} else {
	codeStream.pop();
	}
	codeStream.recordPositionsFrom(pc, this.sourceStart);
	}
	@Override
	public void generateOptimizedBoolean(BlockScope currentScope, CodeStream codeStream, BranchLabel trueLabel, BranchLabel falseLabel, boolean valueRequired) {
	// a label valued to nil means: by default we fall through the case...
	// both nil means we leave the value on the stack

	if (this.elementVariable == null) {
	super.generateOptimizedBoolean(currentScope, codeStream, trueLabel, falseLabel, valueRequired);
	return;
	}
	Constant cst = optimizedBooleanConstant();
	addPatternVariables(currentScope, codeStream);

	int pc = codeStream.position;

	addAssignment(currentScope, codeStream, this.secretInstanceOfPatternExpressionValue);
	codeStream.load(this.secretInstanceOfPatternExpressionValue);

	BranchLabel nextSibling = falseLabel != null ? falseLabel : new BranchLabel(codeStream);
	codeStream.instance_of(this.type, this.type.resolvedType);
	if (this.elementVariable != null) {
	codeStream.ifeq(nextSibling);
	codeStream.load(this.secretInstanceOfPatternExpressionValue);
	codeStream.checkcast(this.type, this.type.resolvedType, codeStream.position);
	codeStream.dup();
	codeStream.store(this.elementVariable.binding, false);

	codeStream.load(this.secretInstanceOfPatternExpressionValue);
	codeStream.removeVariable(this.secretInstanceOfPatternExpressionValue);
	codeStream.checkcast(this.type, this.type.resolvedType, codeStream.position);
	}
	if (valueRequired && cst == Constant.NotAConstant) {
	codeStream.generateImplicitConversion(this.implicitConversion);
	} else {
	codeStream.pop();
	}
	codeStream.recordPositionsFrom(pc, this.sourceStart);


	if ((cst != Constant.NotAConstant) && (cst.typeID() == TypeIds.T_boolean)) {
	pc = codeStream.position;
	if (cst.booleanValue() == true) {
	// constant == true
	if (valueRequired) {
	if (falseLabel == null) {
	// implicit falling through the FALSE case
	if (trueLabel != null) {
	codeStream.goto_(trueLabel);
	}
	}
	}
	} else {
	if (valueRequired) {
	if (falseLabel != null) {
	// implicit falling through the TRUE case
	if (trueLabel == null) {
	codeStream.goto_(falseLabel);
	}
	}
	}
	}
	codeStream.recordPositionsFrom(pc, this.sourceStart);
	} else {
	// branching
	int position = codeStream.position;
	if (valueRequired) {
	if (falseLabel == null) {
	if (trueLabel != null) {
	// Implicit falling through the FALSE case
	codeStream.if_acmpeq(trueLabel);
	}
	} else {
	if (trueLabel == null) {
	// Implicit falling through the TRUE case
	codeStream.if_acmpne(falseLabel);
	} else {
	// No implicit fall through TRUE/FALSE --> should never occur
	}
	}
	}
	codeStream.recordPositionsFrom(position, this.sourceEnd);
	}
	if (nextSibling != falseLabel)
	nextSibling.place();
	}

	private void addAssignment(BlockScope currentScope, CodeStream codeStream, LocalVariableBinding local) {
	assert local != null;
	SingleNameReference lhs = new SingleNameReference(local.name, 0);
	lhs.binding = local;
	lhs.bits &= ~ASTNode.RestrictiveFlagMASK; // clear bits
	lhs.bits \|= Binding.LOCAL;
	lhs.bits \|= ASTNode.IsSecretYieldValueUsage;
	((LocalVariableBinding) lhs.binding).markReferenced(); // TODO : Can be skipped?
	Assignment assignment = new Assignment(lhs, this.expression, 0);
	assignment.generateCode(currentScope, codeStream);
	codeStream.addVariable(this.secretInstanceOfPatternExpressionValue);
	}

	@Override
	public StringBuffer printExpressionNoParenthesis(int indent, StringBuffer output) {
	this.expression.printExpression(indent, output).append(" instanceof "); //$NON-NLS-1$
	return this.elementVariable == null ? this.type.print(0, output) : this.elementVariable.printAsExpression(0, output);
	}

	@Override
	public void addPatternVariables(BlockScope currentScope, CodeStream codeStream) {
	if (this.elementVariable != null) {
	codeStream.addVisibleLocalVariable(this.elementVariable.binding);
	}
	}
	public void resolvePatternVariable(BlockScope scope) {
	if (this.elementVariable != null && this.elementVariable.binding == null) {
	this.elementVariable.resolve(scope, true);
	this.elementVariable.binding.modifiers \|= ExtraCompilerModifiers.AccPatternVariable;
	this.elementVariable.binding.useFlag = LocalVariableBinding.USED;
	// Why cant this be done in the constructor?
	this.type = this.elementVariable.type;
	}
	}
	@Override
	public boolean containsPatternVariable() {
	return this.elementVariable != null;
	}
	private void addSecretInstanceOfPatternExpressionValue(BlockScope scope1) {
	LocalVariableBinding local =
	new LocalVariableBinding(
	InstanceOfExpression.SECRET_INSTANCEOF_PATTERN_EXPRESSION_VALUE,
	TypeBinding.wellKnownType(scope1, T_JavaLangObject),
	ClassFileConstants.AccDefault,
	false);
	local.setConstant(Constant.NotAConstant);
	local.useFlag = LocalVariableBinding.USED;
	local.declaration = new LocalDeclaration(InstanceOfExpression.SECRET_INSTANCEOF_PATTERN_EXPRESSION_VALUE, 0, 0);
	scope1.addLocalVariable(local);
	this.secretInstanceOfPatternExpressionValue = local;
	}

	@Override
	public TypeBinding resolveType(BlockScope scope) {
	this.constant = Constant.NotAConstant;
	if (this.elementVariable != null)
	addSecretInstanceOfPatternExpressionValue(scope);
	resolvePatternVariable(scope);
	TypeBinding checkedType = this.type.resolveType(scope, true /* check bounds*/);
	if (this.expression instanceof CastExpression) {
	((CastExpression) this.expression).setInstanceofType(checkedType); // for cast expression we need to know instanceof type to not tag unnecessary when needed
	}
	TypeBinding expressionType = this.expression.resolveType(scope);
	if (expressionType != null && checkedType != null && this.type.hasNullTypeAnnotation(AnnotationPosition.ANY)) {
	// don't complain if the entire operation is redundant anyway
	if (!expressionType.isCompatibleWith(checkedType) \|\| NullAnnotationMatching.analyse(checkedType, expressionType, -1).isAnyMismatch())
	scope.problemReporter().nullAnnotationUnsupportedLocation(this.type);
	}
	if (expressionType == null \|\| checkedType == null)
	return null;

	if (this.secretInstanceOfPatternExpressionValue != null && expressionType != TypeBinding.NULL)
	this.secretInstanceOfPatternExpressionValue.type = expressionType;

	if (!checkedType.isReifiable()) {
	CompilerOptions options = scope.compilerOptions();
	// If preview is disabled, report same as before, even at Java 14
	if (options.complianceLevel < ClassFileConstants.JDK14 \|\| !options.enablePreviewFeatures) {
	scope.problemReporter().illegalInstanceOfGenericType(checkedType, this);
	} else {
	if (options.isAnyEnabled(IrritantSet.PREVIEW)) {
	scope.problemReporter().previewFeatureUsed(this.type.sourceStart, this.type.sourceEnd);
	}
	if (expressionType != TypeBinding.NULL) {
	boolean isLegal = checkCastTypesCompatibility(scope, checkedType, expressionType, this.expression, true);
	if (!isLegal \|\| (this.bits & ASTNode.UnsafeCast) != 0) {
	scope.problemReporter().unsafeCastInInstanceof(this.expression, checkedType, expressionType);
	}
	}
	}
	} else if (checkedType.isValidBinding()) {
	// if not a valid binding, an error has already been reported for unresolved type
	if ((expressionType != TypeBinding.NULL && expressionType.isBaseType()) // disallow autoboxing
	\|\| checkedType.isBaseType()
	\|\| !checkCastTypesCompatibility(scope, checkedType, expressionType, null, true)) {
	scope.problemReporter().notCompatibleTypesError(this, expressionType, checkedType);
	}
	}
	return this.resolvedType = TypeBinding.BOOLEAN;
	}
	@Override
	public boolean checkUnsafeCast(Scope scope, TypeBinding castType, TypeBinding expressionType, TypeBinding match, boolean isNarrowing) {
	if (!castType.isReifiable())
	return CastExpression.checkUnsafeCast(this, scope, castType, expressionType, match, isNarrowing);
	else
	return super.checkUnsafeCast(scope, castType, expressionType, match, isNarrowing);
	}
	/**
	* @see org.eclipse.jdt.internal.compiler.ast.Expression#tagAsUnnecessaryCast(Scope,TypeBinding)
	*/

	@Override
	public void tagAsUnnecessaryCast(Scope scope, TypeBinding castType) {
	// null is not instanceof Type, recognize direct scenario
	if (this.expression.resolvedType != TypeBinding.NULL)
	scope.problemReporter().unnecessaryInstanceof(this, castType);
	}

	@Override
	public void traverse(ASTVisitor visitor, BlockScope scope) {
	if (visitor.visit(this, scope)) {
	this.expression.traverse(visitor, scope);
	if (this.elementVariable != null) {
	this.elementVariable.traverse(visitor, scope);
	} else {
	this.type.traverse(visitor, scope);
	}
	}
	visitor.endVisit(this, scope);
	}
	}