KSP doesn't see class as open when opened with `allopen` Gradle plugin

[MarkAmeryCurative]

If you use the allopen plugin to mark a class and its members as open, KSP doesn't seem to recognise that you've done so, at least when used in conjunction with Micronaut AOP.

For a minimal example:

• Create a new Micronaut project, with the micronaut-aop feature, using Micronaut Launch.

• Define and use an AOP method annotation:

  @Retention(AnnotationRetention.RUNTIME)
  @Target(FUNCTION)
  @Around
  annotation class MyAopAnnotation
  
  @Singleton
  class Foo {
    @MyAopAnnotation
    fun bar(): List<String> = listOf("bla")
  }

• Mark the class as open using allopen in build.gradle.kts:

  allOpen {
    annotation("jakarta.inject.Singleton")
  }

• Try to compile

I've created a demo project at https://github.com/MarkAmeryCurative/ksp-aop-bug-demo you can use to see the bug in action. Just clone the project and run ./gradlew compileKotlin, and you'll see this error:

$ ./gradlew compileKotlin

> Task :kspKotlin FAILED
e: [ksp] Originating element: bar
e: [ksp] /home/mark/ksp-aop-bug-demo/src/main/kotlin/com/example/Application.kt:19: Method defines AOP advice but is declared final. Change the method to be non-final in order for AOP advice to be applied.
e: Error occurred in KSP, check log for detail

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':kspKotlin'.
> A failure occurred while executing org.jetbrains.kotlin.compilerRunner.GradleCompilerRunnerWithWorkers$GradleKotlinCompilerWorkAction
   > Compilation error. See log for more details

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.
> Get more help at https://help.gradle.org.

Deprecated Gradle features were used in this build, making it incompatible with Gradle 9.0.

You can use '--warning-mode all' to show the individual deprecation warnings and determine if they come from your own scripts or plugins.

For more on this, please refer to https://docs.gradle.org/8.3/userguide/command_line_interface.html#sec:command_line_warnings in the Gradle documentation.

BUILD FAILED in 3s
1 actionable task: 1 executed

i.e. KSP sees the class as non-open even though it's being opened with allopen.

[efemoney]

I would imagine this is because ksp runs (its own task) before the actual kotlin compilation (where compiler plugins run). I am not sure what a solution would look like here tbh

[MarkAmeryCurative]

Kapt also runs before actual Kotlin compilation, but somehow manages to respect allopen. So looking at Kapt's code and seeing how they manage it might inspire a solution.

[waveskimmer]

I'm seeing the same issue.

[EliasJorgensen]

Just ran into this issue as well. It's been a bit over half a year, has there been any progress on this issue? 🙏