On Tue, 1 Dec 2020 19:34:11 GMT, Chris Hegarty <che...@openjdk.org> wrote:
> Update Class::isRecord to only return true for classes that are final.
>
> The removal of non-specified JVM checks on classes with a Record Attribute
> (see JDK-8255342), has resulted in more types of loadable classes that may
> contain a Record Attribute. Since these checks are not performed by the JVM
> anymore, Class::isRecord, and by extension Class::getRecordComponents, may
> return true or component values, respectively, for classes that are not
> well-formed record classes (as per the JLS), .e.g. non-final or abstract
> classes, that contain a record Attribute.
>
> Core Reflection, Class::isRecord, already asserts checks that the JVM does
> not, e.g. that the direct superclass is java.lang.Record. Some points from
> the Java Language Specification for record classes:
>
> 1. It is a compile-time error if a record declaration has the modifier
> abstract.
> 2. A record declaration is implicitly final.
> 3. The direct superclass type of a record class is Record.
>
> Class::isRecord already ensures no.3. This issue proposes to add explicit
> checks in Core Reflection to ensure no.1 and no.2, since the JVM now allows
> such classes that contain a Record Attribute to be loaded.
test/jdk/java/lang/reflect/records/IsRecordTest.java line 138:
> 136: record EmptyRecord () { }
> 137: assertTrue(EmptyRecord.class.isRecord());
> 138: assertTrue(EmptyRecord.class.getRecordComponents() != null);
Better to have a more precise check for empty array
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PR: https://git.openjdk.java.net/jdk/pull/1543
