Class validation cleanups

[Harold Seigel]

Hi Dan,

Do you expect these spec modifications to require changes in both the 
old and new verifiers?

Thanks, Harold

On 11/8/2019 4:04 PM, Dan Smith wrote:
> I've put together some JVMS change proposals to improve its specification of the class validation process, including class loading, format checking, and verification.
>
> These are independent of Valhalla, but lay the groundwork for additional changes to the spec. They address things like:
>
> - How are <init> and <clinit> methods constrained?
> - Can array types be field/method receiver types? (Yes, it turns out.)
> - When do we enforce the 'final' modifier on classes/methods?
> - Which attributes are validated, and when?
> - How does class loading handle anomalous situations?
>
> For format checking refinements:
> https://bugs.openjdk.java.net/browse/JDK-8233854
> http://cr.openjdk.java.net/~dlsmith/class-validation/class-validation-20191107/specs/format-checking-jvms.html
>
> For class loading cleanup:
> https://bugs.openjdk.java.net/browse/JDK-8233861
> http://cr.openjdk.java.net/~dlsmith/class-validation/class-validation-20191107/specs/class-loading-jvms.html
>
> For attribute validation:
> https://bugs.openjdk.java.net/browse/JDK-8233863
> http://cr.openjdk.java.net/~dlsmith/class-validation/class-validation-20191107/specs/attribute-validation-jvms.html
>
> The last is the most disruptive, since we're proposing simply ignoring some attribute contents that has traditionally been parsed and validated. I think it may be reasonable to create a JEP for that piece.