/** * 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); } } }
/** * 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); } }
public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) { if (this.constantExpression != null) { if (this.constantExpression.constant == Constant.NotAConstant && !this.constantExpression.resolvedType.isEnum()) { currentScope.problemReporter().caseExpressionMustBeConstant(this.constantExpression); } this.constantExpression.analyseCode(currentScope, flowContext, flowInfo); } return flowInfo; }
/** * 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; // 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*/)) return; scope.problemReporter().unnecessaryCast(nestedCast); }
/** * 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); } }
/** * 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; } } }
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(); boolean isLegal = checkCastTypesCompatibility(scope, castType, expressionType, this.expression); 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; }
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() { public TypeBinding[] genericTypeArguments() { return null; } public boolean isSuperAccess() { return invocationSite.isSuperAccess(); } public boolean isTypeAccess() { return invocationSite.isTypeAccess(); } public void setActualReceiverType(ReferenceBinding actualReceiverType) { /* ignore */ } public void setDepth(int depth) { /* ignore */ } public void setFieldIndex(int depth) { /* ignore */ } public int sourceStart() { return 0; } public int sourceEnd() { return 0; } public TypeBinding invocationTargetType() { return invocationSite.invocationTargetType(); } public boolean receiverIsImplicitThis() { return invocationSite.receiverIsImplicitThis(); } public InferenceContext18 freshInferenceContext(Scope someScope) { return invocationSite.freshInferenceContext(someScope); } public ExpressionContext getExpressionContext() { return invocationSite.getExpressionContext(); } public boolean isQualifiedSuper() { return invocationSite.isQualifiedSuper(); } public boolean checkingPotentialCompatibility() { return false; } 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])*/ ) { scope.problemReporter().unnecessaryCast((CastExpression) arguments[i]); } } } }
/** 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; // 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 || scope.environment().computeBoxingType(alternateLeftType).id == leftTypeId) { // 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 || scope.environment().computeBoxingType(alternateRightType).id == rightTypeId) { // 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); } } }
/** * Returns the constant intValue or ordinal for enum constants. If constant is NotAConstant, then * answers Float.MIN_VALUE * * @see * org.aspectj.org.eclipse.jdt.internal.compiler.ast.Statement#resolveCase(org.aspectj.org.eclipse.jdt.internal.compiler.lookup.BlockScope, * org.aspectj.org.eclipse.jdt.internal.compiler.lookup.TypeBinding, * org.aspectj.org.eclipse.jdt.internal.compiler.ast.SwitchStatement) */ public Constant resolveCase( BlockScope scope, TypeBinding switchExpressionType, SwitchStatement switchStatement) { // switchExpressionType maybe null in error case scope.enclosingCase = this; // record entering in a switch case block if (this.constantExpression == null) { // remember the default case into the associated switch statement if (switchStatement.defaultCase != null) scope.problemReporter().duplicateDefaultCase(this); // on error the last default will be the selected one ... switchStatement.defaultCase = this; return Constant.NotAConstant; } // add into the collection of cases of the associated switch statement switchStatement.cases[switchStatement.caseCount++] = this; // tag constant name with enum type for privileged access to its members if (switchExpressionType != null && switchExpressionType.isEnum() && (this.constantExpression instanceof SingleNameReference)) { ((SingleNameReference) this.constantExpression) .setActualReceiverType((ReferenceBinding) switchExpressionType); } TypeBinding caseType = this.constantExpression.resolveType(scope); if (caseType == null || switchExpressionType == null) return Constant.NotAConstant; if (this.constantExpression.isConstantValueOfTypeAssignableToType( caseType, switchExpressionType) || caseType.isCompatibleWith(switchExpressionType)) { if (caseType.isEnum()) { if (((this.constantExpression.bits & ASTNode.ParenthesizedMASK) >> ASTNode.ParenthesizedSHIFT) != 0) { scope .problemReporter() .enumConstantsCannotBeSurroundedByParenthesis(this.constantExpression); } if (this.constantExpression instanceof NameReference && (this.constantExpression.bits & ASTNode.RestrictiveFlagMASK) == Binding.FIELD) { NameReference reference = (NameReference) this.constantExpression; FieldBinding field = reference.fieldBinding(); if ((field.modifiers & ClassFileConstants.AccEnum) == 0) { scope.problemReporter().enumSwitchCannotTargetField(reference, field); } else if (reference instanceof QualifiedNameReference) { scope.problemReporter().cannotUseQualifiedEnumConstantInCaseLabel(reference, field); } return IntConstant.fromValue( field.original().id + 1); // (ordinal value + 1) zero should not be returned see bug 141810 } } else { return this.constantExpression.constant; } } else if (isBoxingCompatible(caseType, switchExpressionType, this.constantExpression, scope)) { // constantExpression.computeConversion(scope, caseType, switchExpressionType); - do not // report boxing/unboxing conversion return this.constantExpression.constant; } scope .problemReporter() .typeMismatchError( caseType, switchExpressionType, this.constantExpression, switchStatement.expression); return Constant.NotAConstant; }