| /******************************************************************************* |
| * 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 |
| * Nick Teryaev - fix for bug (https://bugs.eclipse.org/bugs/show_bug.cgi?id=40752) |
| * Stephan Herrmann - Contributions for |
| * bug 319201 - [null] no warning when unboxing SingleNameReference causes NPE |
| * bug 345305 - [compiler][null] Compiler misidentifies a case of "variable can only be null" |
| * bug 395002 - Self bound generic class doesn't resolve bounds properly for wildcards for certain parametrisation. |
| * bug 383368 - [compiler][null] syntactic null analysis for field references |
| * bug 401017 - [compiler][null] casted reference to @Nullable field lacks a warning |
| * bug 400761 - [compiler][null] null may be return as boolean without a diagnostic |
| * 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 400874 - [1.8][compiler] Inference infrastructure should evolve to meet JLS8 18.x (Part G of JSR335 spec) |
| * Bug 427438 - [1.8][compiler] NPE at org.eclipse.jdt.internal.compiler.ast.ConditionalExpression.generateCode(ConditionalExpression.java:280) |
| * Bug 430150 - [1.8][null] stricter checking against type variables |
| * Bug 435805 - [1.8][compiler][null] Java 8 compiler does not recognize declaration style null annotations |
| * Bug 407414 - [compiler][null] Incorrect warning on a primitive type being null |
| * Andy Clement (GoPivotal, Inc) aclement@gopivotal.com - Contributions for |
| * Bug 415541 - [1.8][compiler] Type annotations in the body of static initializer get dropped |
| *******************************************************************************/ |
| package org.eclipse.jdt.internal.compiler.ast; |
| |
| import static org.eclipse.jdt.internal.compiler.ast.ExpressionContext.CASTING_CONTEXT; |
| |
| import org.eclipse.jdt.internal.compiler.ASTVisitor; |
| import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants; |
| import org.eclipse.jdt.internal.compiler.codegen.CodeStream; |
| import org.eclipse.jdt.internal.compiler.flow.FlowContext; |
| import org.eclipse.jdt.internal.compiler.flow.FlowInfo; |
| 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.ArrayBinding; |
| import org.eclipse.jdt.internal.compiler.lookup.Binding; |
| import org.eclipse.jdt.internal.compiler.lookup.BlockScope; |
| import org.eclipse.jdt.internal.compiler.lookup.InferenceContext18; |
| import org.eclipse.jdt.internal.compiler.lookup.InvocationSite; |
| import org.eclipse.jdt.internal.compiler.lookup.LocalVariableBinding; |
| import org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment; |
| import org.eclipse.jdt.internal.compiler.lookup.MethodBinding; |
| import org.eclipse.jdt.internal.compiler.lookup.ParameterizedGenericMethodBinding; |
| import org.eclipse.jdt.internal.compiler.lookup.ParameterizedTypeBinding; |
| import org.eclipse.jdt.internal.compiler.lookup.PolymorphicMethodBinding; |
| import org.eclipse.jdt.internal.compiler.lookup.ReferenceBinding; |
| import org.eclipse.jdt.internal.compiler.lookup.Scope; |
| import org.eclipse.jdt.internal.compiler.lookup.TagBits; |
| import org.eclipse.jdt.internal.compiler.lookup.TypeBinding; |
| import org.eclipse.jdt.internal.compiler.lookup.TypeIds; |
| import org.eclipse.jdt.internal.compiler.problem.ProblemSeverities; |
| |
| public class CastExpression extends Expression { |
| |
| public Expression expression; |
| public TypeReference type; |
| public TypeBinding expectedType; // when assignment conversion to a given expected type: String s = (String) t; |
| public TypeBinding instanceofType; // set by InstanceofExpression to ensure we don't flag a necessary cast unnecessary |
| public boolean isVarTypeDeclaration; // set by LocalDeclaration to indicate we are initializing a var type declaration |
| |
| //expression.implicitConversion holds the cast for baseType casting |
| public CastExpression(Expression expression, TypeReference type) { |
| this.expression = expression; |
| this.type = type; |
| type.bits |= ASTNode.IgnoreRawTypeCheck; // no need to worry about raw type usage |
| } |
| |
| @Override |
| public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) { |
| FlowInfo result = this.expression |
| .analyseCode(currentScope, flowContext, flowInfo) |
| .unconditionalInits(); |
| this.expression.checkNPEbyUnboxing(currentScope, flowContext, flowInfo); |
| // account for pot. CCE: |
| flowContext.recordAbruptExit(); |
| return result; |
| } |
| |
| /** |
| * Complain if assigned expression is cast, but not actually used as such, e.g. Object o = (List) object; |
| */ |
| public static void checkNeedForAssignedCast(BlockScope scope, TypeBinding expectedType, CastExpression rhs) { |
| CompilerOptions compilerOptions = scope.compilerOptions(); |
| if (compilerOptions.getSeverity(CompilerOptions.UnnecessaryTypeCheck) == ProblemSeverities.Ignore) return; |
| |
| TypeBinding castedExpressionType = rhs.expression.resolvedType; |
| // int i = (byte) n; // cast still had side effect |
| // double d = (float) n; // cast to float is unnecessary |
| if (castedExpressionType == null || rhs.resolvedType.isBaseType()) return; |
| //if (castedExpressionType.id == T_null) return; // tolerate null expression cast |
| if (castedExpressionType.isCompatibleWith(expectedType, scope)) { |
| if (scope.environment().usesNullTypeAnnotations()) { |
| // are null annotations compatible, too? |
| if (NullAnnotationMatching.analyse(expectedType, castedExpressionType, -1).isAnyMismatch()) |
| return; // already reported unchecked cast (nullness), say no more. |
| } |
| scope.problemReporter().unnecessaryCast(rhs); |
| } |
| } |
| |
| |
| /** |
| * Complain if cast expression is cast, but not actually needed, int i = (int)(Integer) 12; |
| * Note that this (int) cast is however needed: Integer i = 0; char c = (char)((int) i); |
| */ |
| public static void checkNeedForCastCast(BlockScope scope, CastExpression enclosingCast) { |
| if (scope.compilerOptions().getSeverity(CompilerOptions.UnnecessaryTypeCheck) == ProblemSeverities.Ignore) return; |
| |
| CastExpression nestedCast = (CastExpression) enclosingCast.expression; |
| if ((nestedCast.bits & ASTNode.UnnecessaryCast) == 0) return; |
| if (nestedCast.losesPrecision(scope)) return; |
| // check if could cast directly to enclosing cast type, without intermediate type cast |
| CastExpression alternateCast = new CastExpression(null, enclosingCast.type); |
| alternateCast.resolvedType = enclosingCast.resolvedType; |
| if (!alternateCast.checkCastTypesCompatibility(scope, enclosingCast.resolvedType, nestedCast.expression.resolvedType, null /* no expr to avoid side-effects*/, true)) return; |
| scope.problemReporter().unnecessaryCast(nestedCast); |
| } |
| |
| private boolean losesPrecision(Scope scope) { |
| // implements the following from JLS ยง5.1.2: |
| // "A widening primitive conversion from int to float, or from long to float, or from long to double, may result in loss of precision [...]" |
| // (extended to boxed types) |
| TypeBinding exprType = this.expression.resolvedType; |
| if (exprType.isBoxedPrimitiveType()) |
| exprType = scope.environment().computeBoxingType(exprType); |
| switch (this.resolvedType.id) { |
| case TypeIds.T_JavaLangFloat: |
| case TypeIds.T_float: // (float)myInt , (float)myLong need rounding |
| return exprType.id == TypeIds.T_int || exprType.id == TypeIds.T_long; |
| case TypeIds.T_JavaLangDouble: |
| case TypeIds.T_double: // (double)myLong needs rounding |
| return exprType.id == TypeIds.T_long; |
| } |
| return false; |
| } |
| |
| /** |
| * Casting an enclosing instance will considered as useful if removing it would actually bind to a different type |
| */ |
| public static void checkNeedForEnclosingInstanceCast(BlockScope scope, Expression enclosingInstance, TypeBinding enclosingInstanceType, TypeBinding memberType) { |
| if (scope.compilerOptions().getSeverity(CompilerOptions.UnnecessaryTypeCheck) == ProblemSeverities.Ignore) return; |
| |
| TypeBinding castedExpressionType = ((CastExpression)enclosingInstance).expression.resolvedType; |
| if (castedExpressionType == null) return; // cannot do better |
| // obvious identity cast |
| if (TypeBinding.equalsEquals(castedExpressionType, enclosingInstanceType)) { |
| scope.problemReporter().unnecessaryCast((CastExpression)enclosingInstance); |
| } else if (castedExpressionType == TypeBinding.NULL){ |
| return; // tolerate null enclosing instance cast |
| } else { |
| TypeBinding alternateEnclosingInstanceType = castedExpressionType; |
| if (castedExpressionType.isBaseType() || castedExpressionType.isArrayType()) return; // error case |
| if (TypeBinding.equalsEquals(memberType, scope.getMemberType(memberType.sourceName(), (ReferenceBinding) alternateEnclosingInstanceType))) { |
| scope.problemReporter().unnecessaryCast((CastExpression)enclosingInstance); |
| } |
| } |
| } |
| |
| /** |
| * Only complain for identity cast, since other type of casts may be useful: e.g. ~((~(long) 0) << 32) is different from: ~((~0) << 32) |
| */ |
| public static void checkNeedForArgumentCast(BlockScope scope, int operator, int operatorSignature, Expression expression, int expressionTypeId) { |
| if (scope.compilerOptions().getSeverity(CompilerOptions.UnnecessaryTypeCheck) == ProblemSeverities.Ignore) return; |
| |
| // check need for left operand cast |
| if ((expression.bits & ASTNode.UnnecessaryCast) == 0 && expression.resolvedType.isBaseType()) { |
| // narrowing conversion on base type may change value, thus necessary |
| return; |
| } else { |
| TypeBinding alternateLeftType = ((CastExpression)expression).expression.resolvedType; |
| if (alternateLeftType == null) return; // cannot do better |
| if (alternateLeftType.id == expressionTypeId) { // obvious identity cast |
| scope.problemReporter().unnecessaryCast((CastExpression)expression); |
| return; |
| } |
| } |
| } |
| |
| /** |
| * Cast expressions will considered as useful if removing them all would actually bind to a different method |
| * (no fine grain analysis on per casted argument basis, simply separate widening cast from narrowing ones) |
| */ |
| public static void checkNeedForArgumentCasts(BlockScope scope, Expression receiver, TypeBinding receiverType, MethodBinding binding, Expression[] arguments, TypeBinding[] argumentTypes, final InvocationSite invocationSite) { |
| if (scope.compilerOptions().getSeverity(CompilerOptions.UnnecessaryTypeCheck) == ProblemSeverities.Ignore) return; |
| |
| int length = argumentTypes.length; |
| |
| // iterate over arguments, and retrieve original argument types (before cast) |
| TypeBinding[] rawArgumentTypes = argumentTypes; |
| for (int i = 0; i < length; i++) { |
| Expression argument = arguments[i]; |
| if (argument instanceof CastExpression) { |
| // narrowing conversion on base type may change value, thus necessary |
| if ((argument.bits & ASTNode.UnnecessaryCast) == 0 && argument.resolvedType.isBaseType()) { |
| continue; |
| } |
| TypeBinding castedExpressionType = ((CastExpression)argument).expression.resolvedType; |
| if (castedExpressionType == null) return; // cannot do better |
| // obvious identity cast |
| if (TypeBinding.equalsEquals(castedExpressionType, argumentTypes[i])) { |
| scope.problemReporter().unnecessaryCast((CastExpression)argument); |
| } else if (castedExpressionType == TypeBinding.NULL){ |
| continue; // tolerate null argument cast |
| } else if ((argument.implicitConversion & TypeIds.BOXING) != 0) { |
| continue; // boxing has a side effect: (int) char is not boxed as simple char |
| } else { |
| if (rawArgumentTypes == argumentTypes) { |
| System.arraycopy(rawArgumentTypes, 0, rawArgumentTypes = new TypeBinding[length], 0, length); |
| } |
| // retain original argument type |
| rawArgumentTypes[i] = castedExpressionType; |
| } |
| } |
| } |
| // perform alternate lookup with original types |
| if (rawArgumentTypes != argumentTypes) { |
| checkAlternateBinding(scope, receiver, receiverType, binding, arguments, argumentTypes, rawArgumentTypes, invocationSite); |
| } |
| } |
| |
| /** |
| * Check binary operator casted arguments |
| */ |
| public static void checkNeedForArgumentCasts(BlockScope scope, int operator, int operatorSignature, Expression left, int leftTypeId, boolean leftIsCast, Expression right, int rightTypeId, boolean rightIsCast) { |
| if (scope.compilerOptions().getSeverity(CompilerOptions.UnnecessaryTypeCheck) == ProblemSeverities.Ignore) return; |
| |
| boolean useAutoBoxing = operator != OperatorIds.EQUAL_EQUAL && operator != OperatorIds.NOT_EQUAL; |
| // check need for left operand cast |
| int alternateLeftTypeId = leftTypeId; |
| if (leftIsCast) { |
| if ((left.bits & ASTNode.UnnecessaryCast) == 0 && left.resolvedType.isBaseType()) { |
| // narrowing conversion on base type may change value, thus necessary |
| leftIsCast = false; |
| } else { |
| TypeBinding alternateLeftType = ((CastExpression)left).expression.resolvedType; |
| if (alternateLeftType == null) return; // cannot do better |
| if ((alternateLeftTypeId = alternateLeftType.id) == leftTypeId |
| || (useAutoBoxing |
| ? scope.environment().computeBoxingType(alternateLeftType).id == leftTypeId |
| : TypeBinding.equalsEquals(alternateLeftType, left.resolvedType))) { // obvious identity cast |
| scope.problemReporter().unnecessaryCast((CastExpression)left); |
| leftIsCast = false; |
| } else if (alternateLeftTypeId == TypeIds.T_null) { |
| alternateLeftTypeId = leftTypeId; // tolerate null argument cast |
| leftIsCast = false; |
| } |
| } |
| } |
| // check need for right operand cast |
| int alternateRightTypeId = rightTypeId; |
| if (rightIsCast) { |
| if ((right.bits & ASTNode.UnnecessaryCast) == 0 && right.resolvedType.isBaseType()) { |
| // narrowing conversion on base type may change value, thus necessary |
| rightIsCast = false; |
| } else { |
| TypeBinding alternateRightType = ((CastExpression)right).expression.resolvedType; |
| if (alternateRightType == null) return; // cannot do better |
| if ((alternateRightTypeId = alternateRightType.id) == rightTypeId |
| || (useAutoBoxing |
| ? scope.environment().computeBoxingType(alternateRightType).id == rightTypeId |
| : TypeBinding.equalsEquals(alternateRightType, right.resolvedType))) { // obvious identity cast |
| scope.problemReporter().unnecessaryCast((CastExpression)right); |
| rightIsCast = false; |
| } else if (alternateRightTypeId == TypeIds.T_null) { |
| alternateRightTypeId = rightTypeId; // tolerate null argument cast |
| rightIsCast = false; |
| } |
| } |
| } |
| if (leftIsCast || rightIsCast) { |
| if (alternateLeftTypeId > 15 || alternateRightTypeId > 15) { // must convert String + Object || Object + String |
| if (alternateLeftTypeId == TypeIds.T_JavaLangString) { |
| alternateRightTypeId = TypeIds.T_JavaLangObject; |
| } else if (alternateRightTypeId == TypeIds.T_JavaLangString) { |
| alternateLeftTypeId = TypeIds.T_JavaLangObject; |
| } else { |
| return; // invalid operator |
| } |
| } |
| int alternateOperatorSignature = OperatorExpression.OperatorSignatures[operator][(alternateLeftTypeId << 4) + alternateRightTypeId]; |
| // (cast) left Op (cast) right --> result |
| // 1111 0000 1111 0000 1111 |
| // <<16 <<12 <<8 <<4 <<0 |
| final int CompareMASK = (0xF<<16) + (0xF<<8) + 0xF; // mask hiding compile-time types |
| if ((operatorSignature & CompareMASK) == (alternateOperatorSignature & CompareMASK)) { // same promotions and result |
| if (leftIsCast) scope.problemReporter().unnecessaryCast((CastExpression)left); |
| if (rightIsCast) scope.problemReporter().unnecessaryCast((CastExpression)right); |
| } |
| } |
| } |
| |
| @Override |
| public boolean checkNPE(BlockScope scope, FlowContext flowContext, FlowInfo flowInfo, int ttlForFieldCheck) { |
| if((this.resolvedType.tagBits & TagBits.AnnotationNonNull) != 0) { |
| return true; |
| } |
| checkNPEbyUnboxing(scope, flowContext, flowInfo); |
| return this.expression.checkNPE(scope, flowContext, flowInfo, ttlForFieldCheck); |
| } |
| |
| private static void checkAlternateBinding(BlockScope scope, Expression receiver, TypeBinding receiverType, MethodBinding binding, Expression[] arguments, TypeBinding[] originalArgumentTypes, TypeBinding[] alternateArgumentTypes, final InvocationSite invocationSite) { |
| InvocationSite fakeInvocationSite = new InvocationSite(){ |
| @Override |
| public TypeBinding[] genericTypeArguments() { return null; } |
| @Override |
| public boolean isSuperAccess(){ return invocationSite.isSuperAccess(); } |
| @Override |
| public boolean isTypeAccess() { return invocationSite.isTypeAccess(); } |
| @Override |
| public void setActualReceiverType(ReferenceBinding actualReceiverType) { /* ignore */} |
| @Override |
| public void setDepth(int depth) { /* ignore */} |
| @Override |
| public void setFieldIndex(int depth){ /* ignore */} |
| @Override |
| public int sourceStart() { return 0; } |
| @Override |
| public int sourceEnd() { return 0; } |
| @Override |
| public TypeBinding invocationTargetType() { return invocationSite.invocationTargetType(); } |
| @Override |
| public boolean receiverIsImplicitThis() { return invocationSite.receiverIsImplicitThis();} |
| @Override |
| public InferenceContext18 freshInferenceContext(Scope someScope) { return invocationSite.freshInferenceContext(someScope); } |
| @Override |
| public ExpressionContext getExpressionContext() { return invocationSite.getExpressionContext(); } |
| @Override |
| public boolean isQualifiedSuper() { return invocationSite.isQualifiedSuper(); } |
| @Override |
| public boolean checkingPotentialCompatibility() { return false; } |
| @Override |
| public void acceptPotentiallyCompatibleMethods(MethodBinding[] methods) {/* ignore */} |
| }; |
| MethodBinding bindingIfNoCast; |
| if (binding.isConstructor()) { |
| bindingIfNoCast = scope.getConstructor((ReferenceBinding)receiverType, alternateArgumentTypes, fakeInvocationSite); |
| } else { |
| bindingIfNoCast = receiver.isImplicitThis() |
| ? scope.getImplicitMethod(binding.selector, alternateArgumentTypes, fakeInvocationSite) |
| : scope.getMethod(receiverType, binding.selector, alternateArgumentTypes, fakeInvocationSite); |
| } |
| if (bindingIfNoCast == binding) { |
| int argumentLength = originalArgumentTypes.length; |
| if (binding.isVarargs()) { |
| int paramLength = binding.parameters.length; |
| if (paramLength == argumentLength) { |
| int varargsIndex = paramLength - 1; |
| ArrayBinding varargsType = (ArrayBinding) binding.parameters[varargsIndex]; |
| TypeBinding lastArgType = alternateArgumentTypes[varargsIndex]; |
| // originalType may be compatible already, but cast mandated |
| // to clarify between varargs/non-varargs call |
| if (varargsType.dimensions != lastArgType.dimensions()) { |
| return; |
| } |
| if (lastArgType.isCompatibleWith(varargsType.elementsType()) |
| && lastArgType.isCompatibleWith(varargsType)) { |
| return; |
| } |
| } |
| } |
| for (int i = 0; i < argumentLength; i++) { |
| if (TypeBinding.notEquals(originalArgumentTypes[i], alternateArgumentTypes[i]) |
| /*&& !originalArgumentTypes[i].needsUncheckedConversion(alternateArgumentTypes[i])*/) { |
| if (!preventsUnlikelyTypeWarning(originalArgumentTypes[i], alternateArgumentTypes[i], receiverType, binding, scope)) |
| scope.problemReporter().unnecessaryCast((CastExpression)arguments[i]); |
| } |
| } |
| } |
| } |
| |
| private static boolean preventsUnlikelyTypeWarning(TypeBinding castedType, TypeBinding uncastedType, TypeBinding receiverType, MethodBinding binding, BlockScope scope) { |
| if (!scope.compilerOptions().isAnyEnabled(IrritantSet.UNLIKELY_ARGUMENT_TYPE)) |
| return false; |
| if (binding.isStatic() || binding.parameters.length != 1) |
| return false; |
| // would using the uncastedType be considered as dangerous? |
| UnlikelyArgumentCheck argumentChecks = UnlikelyArgumentCheck.determineCheckForNonStaticSingleArgumentMethod( |
| uncastedType, scope, binding.selector, receiverType, binding.parameters); |
| if (argumentChecks != null && argumentChecks.isDangerous(scope)) { |
| // does the cast help? |
| argumentChecks = UnlikelyArgumentCheck.determineCheckForNonStaticSingleArgumentMethod( |
| castedType, scope, binding.selector, receiverType, binding.parameters); |
| if (argumentChecks == null || !argumentChecks.isDangerous(scope)) |
| return true; |
| } |
| return false; |
| } |
| |
| @Override |
| public boolean checkUnsafeCast(Scope scope, TypeBinding castType, TypeBinding expressionType, TypeBinding match, boolean isNarrowing) { |
| return CastExpression.checkUnsafeCast(this, scope, castType, expressionType, match, isNarrowing); |
| } |
| public static boolean checkUnsafeCast(Expression expression, Scope scope, TypeBinding castType, TypeBinding expressionType, TypeBinding match, boolean isNarrowing) { |
| // In case of expression being a InstanceOfExpression, this.resolvedType is null |
| // hence use the type of RHS of the instanceof operator |
| TypeBinding resolvedType = expression.resolvedType != null ? expression.resolvedType : castType; |
| if (TypeBinding.equalsEquals(match, castType)) { |
| if (!isNarrowing && TypeBinding.equalsEquals(match, resolvedType.leafComponentType()) // do not tag as unnecessary when recursing through upper bounds |
| && !(expressionType.isParameterizedType() && expressionType.isProvablyDistinct(castType))) { |
| expression.tagAsUnnecessaryCast(scope, castType); |
| } |
| return true; |
| } |
| if (match != null) { |
| if (isNarrowing |
| ? match.isProvablyDistinct(expressionType) |
| : castType.isProvablyDistinct(match)) { |
| return false; |
| } |
| } |
| switch (castType.kind()) { |
| case Binding.PARAMETERIZED_TYPE : |
| if (!castType.isReifiable()) { |
| if (match == null) { // unrelated types |
| expression.bits |= ASTNode.UnsafeCast; |
| return true; |
| } |
| switch (match.kind()) { |
| case Binding.PARAMETERIZED_TYPE : |
| if (isNarrowing) { |
| // [JLS 5.5] T <: S |
| if (expressionType.isRawType() || !expressionType.isEquivalentTo(match)) { |
| expression.bits |= ASTNode.UnsafeCast; |
| return true; |
| } |
| // [JLS 5.5] S has no subtype X != T, such that |X| == |T| |
| // if I2<T,U> extends I1<T>, then cast from I1<T> to I2<T,U> is unchecked |
| ParameterizedTypeBinding paramCastType = (ParameterizedTypeBinding) castType; |
| ParameterizedTypeBinding paramMatch = (ParameterizedTypeBinding) match; |
| // easy case if less parameters on match |
| TypeBinding[] castArguments = paramCastType.arguments; |
| int length = castArguments == null ? 0 : castArguments.length; |
| if (paramMatch.arguments == null || length > paramMatch.arguments.length) { |
| expression.bits |= ASTNode.UnsafeCast; |
| } else if ((paramCastType.tagBits & (TagBits.HasDirectWildcard|TagBits.HasTypeVariable)) != 0) { |
| // verify alternate cast type, substituting different type arguments |
| nextAlternateArgument: for (int i = 0; i < length; i++) { |
| switch (castArguments[i].kind()) { |
| case Binding.WILDCARD_TYPE : |
| case Binding.TYPE_PARAMETER : |
| break; // check substituting with other |
| default: |
| continue nextAlternateArgument; // no alternative possible |
| } |
| TypeBinding[] alternateArguments; |
| // need to clone for each iteration to avoid env paramtype cache interference |
| System.arraycopy(paramCastType.arguments, 0, alternateArguments = new TypeBinding[length], 0, length); |
| alternateArguments[i] = scope.getJavaLangObject(); |
| LookupEnvironment environment = scope.environment(); |
| ParameterizedTypeBinding alternateCastType = environment.createParameterizedType((ReferenceBinding)castType.erasure(), alternateArguments, castType.enclosingType()); |
| if (TypeBinding.equalsEquals(alternateCastType.findSuperTypeOriginatingFrom(expressionType), match)) { |
| expression.bits |= ASTNode.UnsafeCast; |
| break; |
| } |
| } |
| } |
| return true; |
| } else { |
| // [JLS 5.5] T >: S |
| if (!match.isEquivalentTo(castType)) { |
| expression.bits |= ASTNode.UnsafeCast; |
| return true; |
| } |
| } |
| break; |
| case Binding.RAW_TYPE : |
| expression.bits |= ASTNode.UnsafeCast; // upcast since castType is known to be bound paramType |
| return true; |
| default : |
| if (isNarrowing){ |
| // match is not parameterized or raw, then any other subtype of match will erase to |T| |
| expression.bits |= ASTNode.UnsafeCast; |
| return true; |
| } |
| break; |
| } |
| } |
| break; |
| case Binding.ARRAY_TYPE : |
| TypeBinding leafType = castType.leafComponentType(); |
| if (isNarrowing && (!leafType.isReifiable() || leafType.isTypeVariable())) { |
| expression.bits |= ASTNode.UnsafeCast; |
| return true; |
| } |
| break; |
| case Binding.TYPE_PARAMETER : |
| expression.bits |= ASTNode.UnsafeCast; |
| return true; |
| // (disabled) https://bugs.eclipse.org/bugs/show_bug.cgi?id=240807 |
| // case Binding.TYPE : |
| // if (isNarrowing && match == null && expressionType.isParameterizedType()) { |
| // this.bits |= ASTNode.UnsafeCast; |
| // return true; |
| // } |
| // break; |
| } |
| if (!isNarrowing && TypeBinding.equalsEquals(match, resolvedType.leafComponentType())) { // do not tag as unnecessary when recursing through upper bounds |
| expression.tagAsUnnecessaryCast(scope, castType); |
| } |
| return true; |
| } |
| |
| /** |
| * Cast expression code generation |
| * |
| * @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) { |
| int pc = codeStream.position; |
| boolean annotatedCast = (this.type.bits & ASTNode.HasTypeAnnotations) != 0; |
| boolean needRuntimeCheckcast = (this.bits & ASTNode.GenerateCheckcast) != 0; |
| if (this.constant != Constant.NotAConstant) { |
| if (valueRequired || needRuntimeCheckcast || annotatedCast) { // Added for: 1F1W9IG: IVJCOM:WINNT - Compiler omits casting check |
| codeStream.generateConstant(this.constant, this.implicitConversion); |
| if (needRuntimeCheckcast || annotatedCast) { |
| codeStream.checkcast(this.type, this.resolvedType, pc); |
| } |
| if (!valueRequired) { |
| // the resolveType cannot be double or long |
| codeStream.pop(); |
| } |
| } |
| codeStream.recordPositionsFrom(pc, this.sourceStart); |
| return; |
| } |
| this.expression.generateCode(currentScope, codeStream, annotatedCast || valueRequired || needRuntimeCheckcast); |
| if (annotatedCast || (needRuntimeCheckcast && TypeBinding.notEquals(this.expression.postConversionType(currentScope), this.resolvedType.erasure()))) { // no need to issue a checkcast if already done as genericCast |
| codeStream.checkcast(this.type, this.resolvedType, pc); |
| } |
| if (valueRequired) { |
| codeStream.generateImplicitConversion(this.implicitConversion); |
| } else if (annotatedCast || needRuntimeCheckcast) { |
| switch (this.resolvedType.id) { |
| case T_long : |
| case T_double : |
| codeStream.pop2(); |
| break; |
| default : |
| codeStream.pop(); |
| break; |
| } |
| } |
| codeStream.recordPositionsFrom(pc, this.sourceStart); |
| } |
| |
| public Expression innermostCastedExpression(){ |
| Expression current = this.expression; |
| while (current instanceof CastExpression) { |
| current = ((CastExpression) current).expression; |
| } |
| return current; |
| } |
| |
| /** |
| * @see org.eclipse.jdt.internal.compiler.ast.Expression#localVariableBinding() |
| */ |
| @Override |
| public LocalVariableBinding localVariableBinding() { |
| return this.expression.localVariableBinding(); |
| } |
| |
| @Override |
| public int nullStatus(FlowInfo flowInfo, FlowContext flowContext) { |
| if ((this.implicitConversion & TypeIds.BOXING) != 0) |
| return FlowInfo.NON_NULL; |
| return this.expression.nullStatus(flowInfo, flowContext); |
| } |
| |
| /** |
| * @see org.eclipse.jdt.internal.compiler.ast.Expression#optimizedBooleanConstant() |
| */ |
| @Override |
| public Constant optimizedBooleanConstant() { |
| switch(this.resolvedType.id) { |
| case T_boolean : |
| case T_JavaLangBoolean : |
| return this.expression.optimizedBooleanConstant(); |
| } |
| return Constant.NotAConstant; |
| } |
| |
| @Override |
| public StringBuffer printExpression(int indent, StringBuffer output) { |
| int parenthesesCount = (this.bits & ASTNode.ParenthesizedMASK) >> ASTNode.ParenthesizedSHIFT; |
| String suffix = ""; //$NON-NLS-1$ |
| for(int i = 0; i < parenthesesCount; i++) { |
| output.append('('); |
| suffix += ')'; |
| } |
| output.append('('); |
| this.type.print(0, output).append(") "); //$NON-NLS-1$ |
| return this.expression.printExpression(0, output).append(suffix); |
| } |
| |
| @Override |
| public TypeBinding resolveType(BlockScope scope) { |
| // compute a new constant if the cast is effective |
| |
| this.constant = Constant.NotAConstant; |
| this.implicitConversion = TypeIds.T_undefined; |
| |
| boolean exprContainCast = false; |
| |
| TypeBinding castType = this.resolvedType = this.type.resolveType(scope); |
| if (scope.compilerOptions().sourceLevel >= ClassFileConstants.JDK1_8) { |
| this.expression.setExpressionContext(CASTING_CONTEXT); |
| if (this.expression instanceof FunctionalExpression) { |
| this.expression.setExpectedType(this.resolvedType); |
| this.bits |= ASTNode.DisableUnnecessaryCastCheck; |
| } |
| } |
| if (this.expression instanceof CastExpression) { |
| this.expression.bits |= ASTNode.DisableUnnecessaryCastCheck; |
| exprContainCast = true; |
| } |
| TypeBinding expressionType = this.expression.resolveType(scope); |
| if (this.expression instanceof MessageSend) { |
| MessageSend messageSend = (MessageSend) this.expression; |
| MethodBinding methodBinding = messageSend.binding; |
| if (methodBinding != null && methodBinding.isPolymorphic()) { |
| messageSend.binding = scope.environment().updatePolymorphicMethodReturnType((PolymorphicMethodBinding) methodBinding, castType); |
| if (TypeBinding.notEquals(expressionType, castType)) { |
| expressionType = castType; |
| this.bits |= ASTNode.DisableUnnecessaryCastCheck; |
| } |
| } |
| } |
| if (castType != null) { |
| if (expressionType != null) { |
| |
| boolean nullAnnotationMismatch = scope.compilerOptions().isAnnotationBasedNullAnalysisEnabled |
| && NullAnnotationMatching.analyse(castType, expressionType, -1).isAnyMismatch(); |
| |
| if (this.instanceofType != null && expressionType.isParameterizedType() |
| && expressionType.isProvablyDistinct(this.instanceofType)) { |
| this.bits |= ASTNode.DisableUnnecessaryCastCheck; |
| } |
| if (this.isVarTypeDeclaration && TypeBinding.notEquals(expressionType, castType)) { |
| this.bits |= ASTNode.DisableUnnecessaryCastCheck; |
| } |
| boolean isLegal = checkCastTypesCompatibility(scope, castType, expressionType, this.expression, true); |
| if (isLegal) { |
| this.expression.computeConversion(scope, castType, expressionType); |
| if ((this.bits & ASTNode.UnsafeCast) != 0) { // unsafe cast |
| if (scope.compilerOptions().reportUnavoidableGenericTypeProblems |
| || !(expressionType.isRawType() && this.expression.forcedToBeRaw(scope.referenceContext()))) { |
| scope.problemReporter().unsafeCast(this, scope); |
| } |
| } else if (nullAnnotationMismatch) { |
| // report null annotation issue at medium priority |
| scope.problemReporter().unsafeNullnessCast(this, scope); |
| } else { |
| if (castType.isRawType() && scope.compilerOptions().getSeverity(CompilerOptions.RawTypeReference) != ProblemSeverities.Ignore){ |
| scope.problemReporter().rawTypeReference(this.type, castType); |
| } |
| if ((this.bits & (ASTNode.UnnecessaryCast|ASTNode.DisableUnnecessaryCastCheck)) == ASTNode.UnnecessaryCast) { // unnecessary cast |
| if (!isIndirectlyUsed()) // used for generic type inference or boxing ? |
| scope.problemReporter().unnecessaryCast(this); |
| } |
| } |
| } else { // illegal cast |
| if ((castType.tagBits & TagBits.HasMissingType) == 0) { // no complaint if secondary error |
| scope.problemReporter().typeCastError(this, castType, expressionType); |
| } |
| this.bits |= ASTNode.DisableUnnecessaryCastCheck; // disable further secondary diagnosis |
| } |
| } |
| this.resolvedType = castType.capture(scope, this.type.sourceStart, this.type.sourceEnd); // make it unique, a cast expression shares source end with the expression. |
| if (exprContainCast) { |
| checkNeedForCastCast(scope, this); |
| } |
| } |
| return this.resolvedType; |
| } |
| |
| /** |
| * @see org.eclipse.jdt.internal.compiler.ast.Expression#setExpectedType(org.eclipse.jdt.internal.compiler.lookup.TypeBinding) |
| */ |
| @Override |
| public void setExpectedType(TypeBinding expectedType) { |
| this.expectedType = expectedType; |
| } |
| |
| /** |
| * Determines whether apparent unnecessary cast wasn't actually used to |
| * perform return type inference of generic method invocation or boxing. |
| */ |
| private boolean isIndirectlyUsed() { |
| if (this.expression instanceof MessageSend) { |
| MethodBinding method = ((MessageSend)this.expression).binding; |
| if (method instanceof ParameterizedGenericMethodBinding |
| && ((ParameterizedGenericMethodBinding)method).inferredReturnType) { |
| if (this.expectedType == null) |
| return true; |
| if (TypeBinding.notEquals(this.resolvedType, this.expectedType)) |
| return true; |
| } |
| } |
| if (this.expectedType != null && this.resolvedType.isBaseType() && !this.resolvedType.isCompatibleWith(this.expectedType)) { |
| // boxing: Short s = (short) _byte |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * @see org.eclipse.jdt.internal.compiler.ast.Expression#tagAsNeedCheckCast() |
| */ |
| @Override |
| public void tagAsNeedCheckCast() { |
| this.bits |= ASTNode.GenerateCheckcast; |
| } |
| |
| /** |
| * @see org.eclipse.jdt.internal.compiler.ast.Expression#tagAsUnnecessaryCast(Scope, TypeBinding) |
| */ |
| @Override |
| public void tagAsUnnecessaryCast(Scope scope, TypeBinding castType) { |
| this.bits |= ASTNode.UnnecessaryCast; |
| } |
| |
| public void setInstanceofType(TypeBinding instanceofTypeBinding) { |
| this.instanceofType = instanceofTypeBinding; |
| } |
| |
| public void setVarTypeDeclaration(boolean value) { |
| this.isVarTypeDeclaration = value; |
| } |
| |
| @Override |
| public void traverse(ASTVisitor visitor, BlockScope blockScope) { |
| if (visitor.visit(this, blockScope)) { |
| this.type.traverse(visitor, blockScope); |
| this.expression.traverse(visitor, blockScope); |
| } |
| visitor.endVisit(this, blockScope); |
| } |
| } |
