RFR: 8315130: java.lang.IllegalAccessError when processing classlist to create CDS archive [v10]

[Timofei Pushkin]

On Wed, 16 Apr 2025 14:34:25 GMT, Timofei Pushkin <tpushkin at openjdk.org> wrote:

>> If a base class is package-private then its subclasses should have the same package name and defining class loader, otherwise `IllegalAccessError` is thrown when linking a subclass. Currently when dumping a static archive separate `URLClassLoader`s are used for each unregistered classes' source. Thus if two unregistered classes, a package-private base class and a sub class, from the same package reside in different sources `IllegalAccessError` will be thrown when linking the sub class. This can be unexpected because the app could have used a single class loader for both classes and thus not have seen the error — see `DifferentSourcesApp.java` from this patch for an example of such app.
>> 
>> This patch fixes the issue by using a single class loader for all unregistered classes. CDS does not allow classes with the same name making such solution possible.
>
> Timofei Pushkin has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 15 commits:
> 
>  - Empty commit to make GH update the PR
>  - Merge remote-tracking branch 'openjdk-jdk/master' into one-loader
>  - Implement super overshadowing warning
>  - Omit Source classes from archive
>  - Remove unused imports
>  - Fix indentation
>  - Extend ClassFromClasspath test
>  - Remove findClass, extend explanation comments
>  - Remove unnecessary scoping
>  - Don't use URLClassPath
>  - ... and 5 more: https://git.openjdk.org/jdk/compare/465c8e65...595756f3

Besides adding the warnings I noticed that `UnregisteredClassLoader` is omitted from the dump and implemented the same for `UnregisteredClassLoader$Source` and its implementations.

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PR Comment: https://git.openjdk.org/jdk/pull/24223#issuecomment-2810027521