This is a follow-up on JDK-8255342 that removes non-specified JVM checks on
classes with Record attributes. That introduces a regression in
`InstanceKlass::is_record` that returns true on a non-record class which has
`RecordComponents` attribute present. This causes unexpected semantics in
`JVM_IsRecord` and `JVM_GetRecordComponents` and also a regression to trust
final fields for non-record classes.
I propose to change `InstanceKlass::is_record` to match the JLS semantic of a
record class, i.e. final direct subclass of `java.lang.Record` with the
presence of `RecordComponents` attribute. There is no change to JVM class file
validation. Also I propose clearly define:
- `JVM_IsRecord` returns true if the given class is a record i.e. final and
direct subclass of `java.lang.Record` with `RecordComponents` attribute
- `JVM_GetRecordComponents` returns an `RecordComponents` array if
`RecordComponents` attribute is present; otherwise, returns NULL. This does
not check if it's a record class or not. So it may return non-null on a
non-record class if it has `RecordComponents` attribute. So
`JVM_GetRecordComponents` returns the content of the classfile.
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Commit messages:
- 8257596: Clarify trusted final fields for record classes
Changes: https://git.openjdk.java.net/jdk/pull/1706/files
Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1706&range=00
Issue: https://bugs.openjdk.java.net/browse/JDK-8257596
Stats: 60 lines in 4 files changed: 30 ins; 10 del; 20 mod
Patch: https://git.openjdk.java.net/jdk/pull/1706.diff
Fetch: git fetch https://git.openjdk.java.net/jdk pull/1706/head:pull/1706
PR: https://git.openjdk.java.net/jdk/pull/1706
