On Mon, 14 Feb 2022 21:00:45 GMT, Joe Darcy <da...@openjdk.org> wrote:
>> This is an early review of changes to better model JVM access flags, that is >> "modifiers" like public, protected, etc. but explicitly at a VM level. >> >> Language level modifiers and JVM level access flags are closely related, but >> distinct. There are concepts that overlap in the two domains (public, >> private, etc.), others that only have a language-level modifier (sealed), >> and still others that only have an access flag (synthetic). >> >> The existing java.lang.reflect.Modifier class is inadequate to model these >> subtleties. For example, the bit positions used by access flags on different >> kinds of elements overlap (such as "volatile" for fields and "bridge" for >> methods. Just having a raw integer does not provide sufficient context to >> decode the corresponding language-level string. Methods like >> Modifier.methodModifiers() were introduced to cope with this situation. >> >> With additional modifiers and flags on the horizon with projects like >> Valhalla, addressing the existent modeling deficiency now ahead of time is >> reasonable before further strain is introduced. >> >> This PR in its current form is meant to give the overall shape of the API. >> It is missing implementations to map from, say, method modifiers to access >> flags, taking into account overlaps in bit positions. >> >> The CSR https://bugs.openjdk.java.net/browse/JDK-8281660 will be filled in >> once the API is further along. > > Joe Darcy has updated the pull request incrementally with one additional > commit since the last revision: > > Respond to review feedback explicitly stating returned sets are immutable. I'm glad to see this proposal moving along to better model the JVM access flags. I think it's right to define a better enhanced API than updating `java.lang.reflect.Modifier` (which is indeed inadequate to provide the sufficient context for modeling). I also think `AccessFlag` is a good class name that well represents the `access_flags` in a class file per the JVM spec. ------------- PR: https://git.openjdk.java.net/jdk/pull/7445
