On Wed, 3 Jan 2024 22:20:15 GMT, Joe Darcy <da...@openjdk.org> wrote:
>>> Since it doesn't seem possible to do so, I did not attempt to relay
>>> "non-sealed" information in this PR :-)
>>
>> Naively, I thought that something like this is possible _in principle_; I
>> might be mistaken though:
>>
>> diff --git a/src/java.base/share/classes/java/lang/Class.java
>> b/src/java.base/share/classes/java/lang/Class.java
>> index 851d65d06ad..014845860d0 100644
>> --- a/src/java.base/share/classes/java/lang/Class.java
>> +++ b/src/java.base/share/classes/java/lang/Class.java
>> @@ -4771,6 +4771,30 @@ public boolean isSealed() {
>> return getPermittedSubclasses() != null;
>> }
>>
>> + private boolean isNonSealed() {
>> + if (isSealed())
>> + return false;
>> + if (!isInterface() && Modifier.isFinal(getModifiers())) {
>> + // unlike interface, class can be final
>> + return false;
>> + }
>> + // if an ancestor is sealed, this class can either be non-sealed or
>> final
>> + return hasSealedAncestor(this);
>> + }
>> +
>> + private boolean hasSealedAncestor(Class<?> clazz) {
>> + var superclass = clazz.getSuperclass();
>> + if (superclass != null) {
>> + if (superclass.isSealed() || hasSealedAncestor(superclass))
>> + return true;
>> + }
>> + for (var superinterface : clazz.getInterfaces()) {
>> + if (superinterface.isSealed() ||
>> hasSealedAncestor(superinterface))
>> + return true;
>> + }
>> + return false;
>> + }
>> +
>> private native Class<?>[] getPermittedSubclasses0();
>>
>> /*
>
> Thanks @pavelrappo; I'll explore incorporating functionality like this into
> the PR, probably next week.
> I think the best place, or least-bad place, to discuss the "modifier"
> ordering of sealed/non-sealed would be an informative note on
> Modifier.toString(int) -- "The sealed/non-sealed Java language modifiers are
> not represented in the class file as access flags and thus not modeled by
> this class [java.lang.reflect.Modifier] .... sealed/non-sealed should be
> presented in the same location as final."
Filed JDK-8322979: Add informative discussion to Modifier.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/17239#discussion_r1441050656
