/** * 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 (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 (memberType == scope.getMemberType( memberType.sourceName(), (ReferenceBinding) alternateEnclosingInstanceType)) { scope.problemReporter().unnecessaryCast((CastExpression) enclosingInstance); } } }
/** * 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) { if (scope.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.problemReporter().unnecessaryCast(rhs); } }
void checkAssignment(BlockScope scope, TypeBinding lhsType, TypeBinding rhsType) { FieldBinding leftField = getLastField(this.lhs); if (leftField != null && rhsType != TypeBinding.NULL && (lhsType.kind() == Binding.WILDCARD_TYPE) && ((WildcardBinding) lhsType).boundKind != Wildcard.SUPER) { scope.problemReporter().wildcardAssignment(lhsType, rhsType, this.expression); } else if (leftField != null && !leftField.isStatic() && leftField.declaringClass != null /*length pseudo field*/ && leftField.declaringClass.isRawType()) { scope.problemReporter().unsafeRawFieldAssignment(leftField, rhsType, this.lhs); } else if (rhsType.needsUncheckedConversion(lhsType)) { scope.problemReporter().unsafeTypeConversion(this.expression, rhsType, lhsType); } }
public TypeBinding resolveType(BlockScope scope) { // due to syntax lhs may be only a NameReference, a FieldReference or an ArrayReference this.constant = Constant.NotAConstant; if (!(this.lhs instanceof Reference) || this.lhs.isThis()) { scope.problemReporter().expressionShouldBeAVariable(this.lhs); return null; } TypeBinding lhsType = lhs.resolveType(scope); this.expression.setExpectedType(lhsType); // needed in case of generic method invocation if (lhsType != null) { this.resolvedType = lhsType.capture(scope, this.sourceEnd); } TypeBinding rhsType = this.expression.resolveType(scope); if (lhsType == null || rhsType == null) { return null; } // check for assignment with no effect Binding left = getDirectBinding(this.lhs); if (left != null && left == getDirectBinding(this.expression)) { scope.problemReporter().assignmentHasNoEffect(this, left.shortReadableName()); } // Compile-time conversion of base-types : implicit narrowing integer into byte/short/character // may require to widen the rhs expression at runtime if (lhsType != rhsType) { // must call before computeConversion() and typeMismatchError() scope.compilationUnitScope().recordTypeConversion(lhsType, rhsType); } if ((this.expression.isConstantValueOfTypeAssignableToType(rhsType, lhsType) || (lhsType.isBaseType() && BaseTypeBinding.isWidening(lhsType.id, rhsType.id))) || rhsType.isCompatibleWith(lhsType)) { this.expression.computeConversion(scope, lhsType, rhsType); checkAssignment(scope, lhsType, rhsType); if (this.expression instanceof CastExpression && (this.expression.bits & ASTNode.UnnecessaryCast) == 0) { CastExpression.checkNeedForAssignedCast(scope, lhsType, (CastExpression) this.expression); } return this.resolvedType; } else if (scope.isBoxingCompatibleWith(rhsType, lhsType) || (rhsType.isBaseType() // narrowing then boxing ? && scope.compilerOptions().sourceLevel >= ClassFileConstants.JDK1_5 // autoboxing && !lhsType.isBaseType() && this.expression.isConstantValueOfTypeAssignableToType( rhsType, scope.environment().computeBoxingType(lhsType)))) { this.expression.computeConversion(scope, lhsType, rhsType); if (this.expression instanceof CastExpression && (this.expression.bits & ASTNode.UnnecessaryCast) == 0) { CastExpression.checkNeedForAssignedCast(scope, lhsType, (CastExpression) this.expression); } return this.resolvedType; } scope.problemReporter().typeMismatchError(rhsType, lhsType, this.expression, this.lhs); return lhsType; }
public TypeBinding resolveType(BlockScope scope) { // compute a new constant if the cast is effective // due to the fact an expression may start with ( and that a cast can also start with ( // the field is an expression....it can be a TypeReference OR a NameReference Or // any kind of Expression <-- this last one is invalid....... this.constant = Constant.NotAConstant; this.implicitConversion = TypeIds.T_undefined; if ((this.type instanceof TypeReference) || (this.type instanceof NameReference) && ((this.type.bits & ASTNode.ParenthesizedMASK) >> ASTNode.ParenthesizedSHIFT) == 0) { // no extra parenthesis around type: ((A))exp boolean exprContainCast = false; TypeBinding castType = this.resolvedType = this.type.resolveType(scope); // expression.setExpectedType(this.resolvedType); // needed in case of generic method // invocation if (this.expression instanceof CastExpression) { this.expression.bits |= ASTNode.DisableUnnecessaryCastCheck; exprContainCast = true; } TypeBinding expressionType = this.expression.resolveType(scope); if (castType != null) { if (expressionType != null) { boolean isLegal = checkCastTypesCompatibility(scope, castType, expressionType, this.expression); if (isLegal) { this.expression.computeConversion(scope, castType, expressionType); if ((this.bits & ASTNode.UnsafeCast) != 0) { // unsafe cast scope.problemReporter().unsafeCast(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.sourceEnd); if (exprContainCast) { checkNeedForCastCast(scope, this); } } return this.resolvedType; } else { // expression as a cast TypeBinding expressionType = this.expression.resolveType(scope); if (expressionType == null) return null; scope.problemReporter().invalidTypeReference(this.type); return null; } }
public boolean checkUnsafeCast( Scope scope, TypeBinding castType, TypeBinding expressionType, TypeBinding match, boolean isNarrowing) { if (match == castType) { if (!isNarrowing && match == this.resolvedType .leafComponentType()) { // do not tag as unnecessary when recursing through upper // bounds 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.isBoundParameterizedType()) { if (match == null) { // unrelated types this.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)) { this.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.length; if (paramMatch.arguments == null || length > paramMatch.arguments.length) { this.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 (alternateCastType.findSuperTypeOriginatingFrom(expressionType) == match) { this.bits |= ASTNode.UnsafeCast; break; } } } return true; } else { // [JLS 5.5] T >: S if (!match.isEquivalentTo(castType)) { this.bits |= ASTNode.UnsafeCast; return true; } } break; case Binding.RAW_TYPE: this.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| this.bits |= ASTNode.UnsafeCast; return true; } break; } } break; case Binding.ARRAY_TYPE: TypeBinding leafType = castType.leafComponentType(); if (isNarrowing && (leafType.isBoundParameterizedType() || leafType.isTypeVariable())) { this.bits |= ASTNode.UnsafeCast; return true; } break; case Binding.TYPE_PARAMETER: this.bits |= ASTNode.UnsafeCast; return true; } if (!isNarrowing && match == this.resolvedType .leafComponentType()) { // do not tag as unnecessary when recursing through upper // bounds tagAsUnnecessaryCast(scope, castType); } return true; }
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; } }; 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 (originalArgumentTypes[i] != alternateArgumentTypes[i]) { scope.problemReporter().unnecessaryCast((CastExpression) arguments[i]); } } } }