RFR: 8344943: Mark not subclassable classes final in java.base exported classes

[Eirik Bjørsnøs]

On Tue, 26 Nov 2024 18:00:21 GMT, Chen Liang <liach at openjdk.org> wrote:

>> Please review this PR which adds the `final` modifier to non-subclassable classes in `java.base`.
>> 
>> The classes were identified using an automated analysis. See CSR for details.
>> 
>> Besides simply adding the `final` access modifier, the PR:
>> 
>> * Updates a note in `java.lang.constant.DynamicCallSiteDesc` to not reference subtypes. See CSR for discussion.
>> * Removes the class `java.lang.Runtime` from the test `test/jdk/jdk/internal/reflect/CallerSensitive/CheckCSMs.java`
>> * Updates the copyright year of affected source files
>
> Changes requested by liach (Reviewer).

Following some offline discussion with @liach, we decided to leave out the constructor access updates in `ModuleDescriptor` and `InterfaceAddress` for now. They are not considered a specification change and adds noise for the CSR review.

These changes may be revisited in this PR pending CSR approval, or can be addressed in follow-up PRs.

> src/java.base/share/classes/java/lang/constant/DynamicCallSiteDesc.java line 44:
> 
>> 42:  * {@code invokedynamic} call site.
>> 43:  *
>> 44:  * <p>This class is immutable and its behavior does not rely on object identity
> 
> Suggestion:
> 
>  * <p>A {@code DynamicCallSiteDesc} is immutable and its behavior does not
>  * rely on object identity.
> 
> This describes an object, not a class, and please close sentences with a period.
> (We use fragments for param and return block tags instead)

Thanks, fixed in 6156b46 :)

> src/java.base/share/classes/java/lang/constant/DynamicCallSiteDesc.java line 45:
> 
>> 43:  *
>> 44:  * <p>Concrete subtypes of {@linkplain DynamicCallSiteDesc} should be immutable
>> 45:  * and their behavior should not rely on object identity.
> 
> Please reword this to something like:
> 
> {@code DynamicCallSiteDesc} is immutable and its behavior does not rely on object identity.
> 
> This is given in `ConstantDesc`, but `DynamicCallSiteDesc` does not extend `ConstantDesc` so the removal is dubious.

Thanks, I've updated the PR and CSR to retain the note about immutability and object identity, removing the reference to subtypes:


This class is immutable and its behavior does not rely on object identity


I opted to replace the self-reference `{@code DynamicCallSiteDesc}` with just "This class" here. Let me know if you prefer spelling out the class name.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/22389#issuecomment-2501808953
PR Review Comment: https://git.openjdk.org/jdk/pull/22389#discussion_r1859123165
PR Review Comment: https://git.openjdk.org/jdk/pull/22389#discussion_r1859051463