At the language level, we won’t let you define a class with an empty set of permitted types; you should define a final class instead.
But, having the VM treat an empty PS attribute as if it were not there seems wrong; I would think an empty PS attribute would be a class file error. > On Apr 2, 2020, at 7:58 AM, Remi Forax <fo...@univ-mlv.fr> wrote: > > Hi all, > With my ASM hat, > from the JVMS POV, javac can not generate an empty list of permitted subtypes > and the implementation in Hotspot ignores the attribute PermittedSubtypes if > there is no subtype listed. > > So currently, ASM doesn't allow you to create an attribute PermittedSubtypes > with an empty number of subtypes. > I believe this is the correct semantics, i just want to be sure that i've not > overlook something. > > regards, > Rémi >