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;
}
/**
* 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);
}
}
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]);
}
}
}
}