On Wed, 22 Jan 2025 03:28:00 GMT, Ioi Lam <ik...@openjdk.org> wrote: > I reimplemented > `SystemDictionaryShared::lookup_super_for_unregistered_class()` with Java > code. This removes hacks in > `SystemDictionary::resolve_with_circularity_detection()` to facilitate future > clean-ups there that are planned by @coleenp. Please see the [JBS > issue](https://bugs.openjdk.org/browse/JDK-8348240) for a discussion of why > the hack was there. > > The new Java code is in the `jdk/internal/misc/CDS$UnregisteredClassLoader` > class. I also simplified `UnregisteredClasses::create_classloader()` by > moving some unwieldy C++ `JavaCalls` code into Java. > > ### How this works: > > For example, let's assume you have the following classfiles in foo.jar: > > > interface MyInterface1 {} > interface MyInterface2 {} > class MyClass extends Object implements MyInterface1, MyInterface2 {} > > > The CDS classlist file can look like this: > > > java/lang/Object id: 1 > MyInterface1: id: 2 super: 1 source: foo.jar > MyInterface2: id: 3 super: 1 source: foo.jar > MyClass: id: 4 super: 1 interfaces: 2 3 source: foo.jar > > > When CDS handles the `MyClass: id: 4` line, it calls > `CDS$UnregisteredClassLoader::load()` with the following parameters: > > - `name` = "MyClass" > - `superClass` = java.lang.Object > - `interfaces` = {MyInterface1, MyInterface2} > > `CDS$UnregisteredClassLoader::load()` will start parsing MyClass.class from > foo.jar. The ClassFileParser will see symbolic references to the supertypes > of `MyClass`. These supertypes will be resolved by > `CDS$UnregisteredClassLoader::findClass()`, using the classes provided by > `superClass` and `interfaces`.
This pull request has now been integrated. Changeset: 7f16a087 Author: Ioi Lam <ik...@openjdk.org> URL: https://git.openjdk.org/jdk/commit/7f16a0875ced8669b9d2131c67496a66e74ea36f Stats: 346 lines in 10 files changed: 193 ins; 115 del; 38 mod 8348240: Remove SystemDictionaryShared::lookup_super_for_unregistered_class() Reviewed-by: ccheung, coleenp ------------- PR: https://git.openjdk.org/jdk/pull/23226
