Good point Matt! Annotation processing has always been an unpleasant magic
to work with from a developer perspective for the reasons you shared. What
are our alternatives? Can't we offer a `META-INF/log4j.factories`
functionality similar to Spring Boot? If so,
1. What are its cons/pros for users?
2. What are its implementation requirements (for the Log4j crew) roughly?
On Fri, Oct 20, 2023 at 7:40 PM Matt Sicker <m...@musigma.org> wrote:
> Snippet from the JDK 21 announcement email that pertains to us. While the
> annotation processor was initially developed to try to be implicit and
> magic, as we’ve seen both in our build and in IDEs, annotation processing
> is typically either disabled by default (in IDEs) or sometimes requires
> manual setup anyways (like in our build). It sounds like starting in Java
> 22, implicit annotation processing will no longer be available. We’ll need
> to ensure our docs about this mention that you need to enable annotation
> processing in your build, too.
>
> > Begin forwarded message:
> >
> > From: David Delabassee <david.delabas...@oracle.com>
> > Subject: JDK 21 Is Now GA, a New VS Code Extension, and an Annotation
> Processing Heads-up
> > Date: October 20, 2023 at 4:39:07 AM CDT
> > To: "dev@logging.apache.org" <dev@logging.apache.org>
> > Reply-To: dev@logging.apache.org
> > List-Id: <dev.logging.apache.org>
> >
> > ## Heads-Up - JDK 22: Implicit Annotation Processing Behavior Change
> >
> > As discussed in the July 2023 Quality Outreach update [8], starting in
> JDK 21 javac emits a note if _implicit_ annotation processing is being
> used, that is, if one or more annotation processors are found and run from
> the class path when no explicit annotation processing configuration options
> are used.
> >
> > The note is reported since, quoting from the note text: "A future
> release of javac may disable annotation processing unless at least one
> processor is specified by name (-processor), or a search path is specified
> (--processor-path, --processor-module-path), or annotation processing is
> enabled explicitly (-proc:only, -proc:full)."
> >
> > That future version of javac has arrived in JDK 22 b19+ with JDK-8306819
> ("Consider disabling the compiler's default active annotation processing").
> In the situation where a note was emitted in JDK 21, in JDK 22 no note is
> emitted, and annotation processors are *not* run. To restore the previous
> behavior with respect to running annotation processors, add the
> '-proc:full' javac option.
> >
> > Feedback on the annotation processing policy change can be sent to
> compiler-dev [9].
> >
> > [8]
> https://mail.openjdk.org/pipermail/quality-discuss/2023-July/001122.html
> > [9] https://mail.openjdk.org/mailman/listinfo/compiler-dev
>
>
