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;
}
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 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;
}
