Support Kotlin Maven builds

[olafurpg]

Currently, lsif-java index can index Gradle Kotlin projects but not Gradle Maven projects.

[simonkoeten-wk]

Hello 👋 is there any update on this issue? Asking because we are attempting to use scip-java for a kotlin & maven project, but unfortunately we run into issues with support for the [kotlin-maven-plugin(https://sourcegraph.github.io/scip-java/docs/getting-started.html#maven). Are there plans to implement this indexing support, or is there a work around?

[olafurpg]

@simonkoeten-wk Thank you for sharing your interest in this feature. There has been no update on this front, and it's not in our near-term roadmap to add automatic indexing support for Kotlin Maven codebases. Note that it might be possible to work around this by adding the Kotlin SemanticDB compiler plugin to your Maven build. For inspiration, you can see how we enable this compiler plugin for Kotlin Gradle projects

scip-java/semanticdb-gradle-plugin/src/main/scala/SemanticdbGradlePlugin.scala

Lines 349 to 355 in 36c9a11

	List(
	"-Xplugin=" + semanticdbKotlinc,
	"-P",
	s"plugin:semanticdb-kotlinc:sourceroot=$sourceRoot",
	"-P",
	s"plugin:semanticdb-kotlinc:targetroot=$targetRoot"
	).asJava