On Mon, 1 Aug 2022 13:30:21 GMT, Harold Seigel <hsei...@openjdk.org> wrote:
>> src/hotspot/share/prims/jvm.cpp line 4064: >> >>> 4062: assert(c->is_instance_klass(), "must be"); >>> 4063: InstanceKlass* ik = InstanceKlass::cast(c); >>> 4064: return (ik->minor_version() << 16) | ik->major_version(); >> >> I'm curious why the format is minor:major rather than major:minor ? > > This was requested by @RogerRiggs > > Major high vs low bits requires either: > High bits: val >>>16 > Low bits: val & 0xffff > > Except for preview, the minor version is 0, so putting major version in the > low bits allows trivial comparison (without masking); but may lead to bugs > due to carelessness. Okay makes sense. >> test/hotspot/jtreg/runtime/ClassFile/ClassFileVersionTest.java line 31: >> >>> 29: * @modules java.base/java.lang:open >>> 30: * @compile classFileVersions.jcod >>> 31: * @run main/othervm --enable-preview ClassFileVersionTest >> >> What preview feature is being used here? > > No preview feature is being used but --enable-preview is needed here for the > JVM to accept a class with a minor version of 65535. Ah I see. ------------- PR: https://git.openjdk.org/jdk/pull/9688
