Code generating annotation processors

[mands]

Hi,

I'm trying to use the record-builder package in my jbang script to provide withers for records.

I read that jbang supports annotation processors but can not get this to work - I'm wondering if it's because the record-builder annotations generate code during compile time.

For example, given the following script,

//DEPS io.soabase.record-builder:record-builder-processor:49
//DEPS io.soabase.record-builder:record-builder-core:49

import io.soabase.recordbuilder.core.RecordBuilder;

@RecordBuilder
record ReleaseInfo(
  Integer nativeVersion,
  Integer apiVersion,
  Set<String> artifacts,
  String command
) implements ReleaseInfoBuilder.With {
}

void main() {
  var r = new ReleaseInfo(1, 2, Set.of(), "").withCommand("testCommand");
  IO.println(r);
}

jbang fails during compilation as ReleaseInfoBuilder.With can't be found, however it generally would have been generated during the annotation processing phase.

/Users/mands/.local/share/mise/installs/jbang/0.132.1/bin/jbang run markRelease.java
[jbang] Building jar for markRelease.java...
/Users/mands/Dev/projects/test/mise-tasks/markRelease.java:128: error: package ReleaseInfoBuilder does not exist
) implements ReleaseInfoBuilder.With {
                               ^
1 error
[jbang] [ERROR] Error during compile
[jbang] Run with --verbose for more details. The --verbose must be placed before the jbang command. I.e. jbang --verbose run [...]

Is there anything else I need to do / missing to get this working? I saw #1650 but was unsure what the resolution was there.

Cheers!

[maxandersen]

I'm not at laptop atm but my first guess is that that annotation processor used are struggling with default unnamed package.

Try add a package statement on top and see if it makes a difference.

[mands]

Thanks for the quick reply.

I added a package statement, and converted the script into a class structure (I was previously using "compact source files" from Java 25). Unfortunately I still get the same error.

When I run with --verbose I can see the existence of both a /classes and /generated folder, which maybe means the annotation processor code is being generated.

[maxandersen]

hmm - let me see. I know I used APT with records before so it did work at some point ;)

[quintesse]

hmm - let me see. I know I used APT with records before so it did work at some point ;)

It did? I guess you could make it work, but you'd at least have to jump through some hoops, right? Starting by having to add compiler options manually to enable/select the processor, I guess. And then how do you get the generated code included? 🤔

It might all work, but I've not done it myself, nor have I seen it being done. But if it doesn't work we should definitely make it work (and if it already works: hooray!)

[maxandersen]

yes, it should "just work" since javac takes take care of it all and compiles the generated source as part of the build - not needed to select individual processors until Java 25+.

[maxandersen]

sorry for the delay in looking into this - but now I've looked and I come with good and some bad or weird news ;)

The good - annotation processors does work with JBang - see https://gist.github.com/maxandersen/0a82685f7182ba8be3edc54132bc2042 for some examples I made to test this.

The bad/weird news: the naked main in java 25 triggers something that fail which I haven't figured out yet why I get the errors. In gist above I made one with non-Java 25 syntax.

Also see the readme for usefull flags to use like:

JAVA_TOOL_OPTIONS=-Djbang.build.keepclasses=true` to keep the generated classes.

Use jbang --build-dir=build ... to get the directory into local dir.

So add jbang --build-dir build --fresh -C-XprintProcessorInfo <script> to get verbose info.

...easier to debug - and definitely realizing we can/should make this simpler/better documented :)

brb - going to fight with java 25 :)

[maxandersen]

ok so first thing is that is not related to naked mains - if I change //JAVA 21 in soabase to //JAVA 25 it fails...so this looks like a behavorial change in Java 25 on how it compiles.

[maxandersen]

ok figured it out (thanks to @quintesse pointing out the obvious :)

In Java 23+ you need to explicitly enable annotation processors, simplest is to put //JAVAC_OPTIONS -proc:full which "restores" the pre-Java 23 behavor.

But that still does not work for soabase because they don't support default package - and to use naked mains you can't use packages.

I've created https://gist.github.com/maxandersen/1e1cc817125ce3abd09525133398d59b with examples of what works and what does not work.

So in conclusion:

• JBang works with anntoation processors
• Java 23+ requires explicit enablement of annotation processor
• soabuilder does not support default package so fails with javac (and thus also jbang) unless you use packages.

[maxandersen]

btw. turns out I opened this in 2024 Randgalt/record-builder#190 but didn't connect the dots ...reopened it with link to this.

[mands]

Got it - thanks for digging into it all - sounds like quite the trip! :)

I think I should be able to get it working using a named packag. I'm using it with mise tasks, so i can put the jbang/java tasks within mise/tasks directory, using tasks as the package name and all should work.