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 void searchVisibleMethods(
ReferenceBinding receiverType,
Scope scope,
InvocationSite invocationSite,
Scope invocationScope,
boolean onlyStaticMethods,
boolean notInJavadoc,
ObjectVector methodsFound) {
ReferenceBinding currentType = receiverType;
if (notInJavadoc) {
if (receiverType.isInterface()) {
searchVisibleInterfaceMethods(
new ReferenceBinding[] {currentType},
receiverType,
scope,
invocationSite,
invocationScope,
onlyStaticMethods,
methodsFound);
currentType = scope.getJavaLangObject();
}
}
boolean hasPotentialDefaultAbstractMethods = true;
while (currentType != null) {
MethodBinding[] methods = currentType.availableMethods();
if (methods != null) {
searchVisibleLocalMethods(
methods,
receiverType,
scope,
invocationSite,
invocationScope,
onlyStaticMethods,
methodsFound);
}
if (notInJavadoc
&& hasPotentialDefaultAbstractMethods
&& (currentType.isAbstract()
|| currentType.isTypeVariable()
|| currentType.isIntersectionType()
|| currentType.isEnum())) {
ReferenceBinding[] superInterfaces = currentType.superInterfaces();
if (superInterfaces != null && currentType.isIntersectionType()) {
for (int i = 0; i < superInterfaces.length; i++) {
superInterfaces[i] =
(ReferenceBinding)
superInterfaces[i].capture(
invocationScope, invocationSite.sourceStart(), invocationSite.sourceEnd());
}
}
searchVisibleInterfaceMethods(
superInterfaces,
receiverType,
scope,
invocationSite,
invocationScope,
onlyStaticMethods,
methodsFound);
} else {
hasPotentialDefaultAbstractMethods = false;
}
if (currentType.isParameterizedType()) {
currentType = ((ParameterizedTypeBinding) currentType).genericType().superclass();
} else {
currentType = currentType.superclass();
}
}
}