RFR: 8353917: jnativescan: Simplify ClassResolver [v2]

[Maurizio Cimadamore]

On Wed, 9 Apr 2025 16:00:52 GMT, Jorn Vernee <jvernee at openjdk.org> wrote:

>> `jnativescan` uses the `ClassResolver` class to find both system classes, as well as application classes. In principle, a class resolver supports both iterating over all classes from that particular source, as well as looking up classes by name. However, the `ClassResolver` for system classes doesn't support iterating, and the lookup functionality for `ClassResolvers` from other sources is never used (only iterating).
>> 
>> This patch proposes to split the iterating functionality out of `ClassResolver`. Clients that were using this functionality will switch to using the iteration functionality that is available on `ClassFileSource` directly (whose classes were previously being wrapped in a `ClassResolver`). As a result of this latter change, we can now also let `NativeMethodFinder` operate on individual classes. We just iterate over all the class file sources in `JNativeScanTask`, and feed individual class models to `NativeMethodFinder`. I think this is a good conceptual simplification of `NativeMethodFinder`,
>> 
>> Since `ClassResolver` is now only used for system classes, I've removed it, leaving only its single implementation: `SystemClassResolver`.
>> 
>> Testing: running `langtools_jnativescan` test suite.
>
> Jorn Vernee has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains four commits:
> 
>  - Merge branch 'master' into jnativescan_Refactor
>  - bump copyright years
>  - merge ClassResolver and SystemClassResolver
>  - Simplify ClassResolver

src/jdk.jdeps/share/classes/com/sun/tools/jnativescan/NativeMethodFinder.java line 97:

> 95:             }
> 96:             Optional<ClassModel> modelOpt = systemClassResolver.lookup(methodRef.owner());
> 97:             if (!modelOpt.isPresent()) {

Maybe add a comment here saying that restricted methods must be in system classes?

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PR Review Comment: https://git.openjdk.org/jdk/pull/24493#discussion_r2037610289