/**
* 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);
}
}
}
/**
* 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 (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);
}
}
/**
* 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);
}
}
/**
* 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);
}
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;
}
/**
* 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
int alternateLeftTypeId = expressionTypeId;
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 ((alternateLeftTypeId = alternateLeftType.id)
== expressionTypeId) { // obvious identity cast
scope.problemReporter().unnecessaryCast((CastExpression) expression);
return;
} else if (alternateLeftTypeId == TypeIds.T_null) {
alternateLeftTypeId = expressionTypeId; // tolerate null argument cast
return;
}
}
/* tolerate widening cast in unary expressions, as may be used when combined in binary expressions (41680)
int alternateOperatorSignature = OperatorExpression.OperatorSignatures[operator][(alternateLeftTypeId << 4) + alternateLeftTypeId];
// (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
scope.problemReporter().unnecessaryCastForArgument((CastExpression)expression, TypeBinding.wellKnownType(scope, expression.implicitConversion >> 4));
}
*/
}
/**
* @see
* xap.lui.compile.ca.jdt.internal.compiler.ast.Expression#resolveTypeExpecting(xap.lui.compile.ca.jdt.internal.compiler.lookup.BlockScope,
* xap.lui.compile.ca.jdt.internal.compiler.lookup.TypeBinding)
*/
public TypeBinding resolveTypeExpecting(BlockScope scope, TypeBinding expectedType) {
TypeBinding type = super.resolveTypeExpecting(scope, expectedType);
if (type == null) return null;
TypeBinding lhsType = this.resolvedType;
TypeBinding rhsType = this.expression.resolvedType;
// signal possible accidental boolean assignment (instead of using '==' operator)
if (expectedType == TypeBinding.BOOLEAN
&& lhsType == TypeBinding.BOOLEAN
&& (this.lhs.bits & IsStrictlyAssigned) != 0) {
scope.problemReporter().possibleAccidentalBooleanAssignment(this);
}
checkAssignment(scope, lhsType, rhsType);
return type;
}
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;
}
}
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]);
}
}
}
}
/** 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) { // 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) { // 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);
}
}
}
