On Tue, 14 Jun 2022 01:25:02 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: > > Make mask fields final in ModuleDescriptor. src/java.base/share/classes/java/lang/reflect/AccessFlag.java line 127: > 125: * 0x0020}. > 126: */ > 127: SUPER(0x0000_0020, false, Set.of(Location.CLASS)), Should we document that this flag won't appear in `Class#accessFlags` no matter if it's declared in the class file? src/java.base/share/classes/java/lang/reflect/AccessFlag.java line 300: > 298: /** > 299: * {@return a set of access flags for the given mask value > 300: * appropriate for the location in question} Should we specify that the returned set is unmodifiable/immutable? ------------- PR: https://git.openjdk.org/jdk/pull/7445