Can 'groovyc' be told to just generate stubs? (Joint-compile of Java+Groovy+Kotlin)

Question

I am trying to get joint/mixed compilation between all of Java, Groovy and Kotlin. I am currently working on a theory that it should be possible if groovyc can be made to just emit stub-files as a first stage.

Can it? Otherwise, any pointers towards making such a feature out of the sources of Groovy?

Here's the idea of full mixed compilation:

1. Have Groovyc create Java-stubs for all its classes. AFAIU, it does this "blind", file by file, without seeing any other sources. (This is the kicker, and what this question is about: Have groovyc (or some part of it) generate only the stubs).
2. Have Kotlinc compile Kotlin-files, basing typing on the Java files for Java, and the Java-stubs for Groovy (by adding them to kotlinc's classpath)
3. Have Javac compile Java-files, basing typing on the Java-stubs of Groovy, and the class-files of Kotlin (by adding them to javac's classpath, or employ -sourcepath for the Java-stubs).
4. Have Groovyc compile Groovy-files, basing typing on class-files for Java, and the class-files for Kotlin (by adding them to groovyc's classpath).

Answer 1

This is relatively easy to do programmatically but not something currently supported from the command line. For programmatic usage, you'd need something like [1], but with the phase on the referenced line changed to SEMANTIC_ANALYSIS. You'd also need to keep the stubs as per [2].

To enable this from the command line, the FileSystemCompiler would need to know about a finishing phase and the unit.compile() statements at [3] would need to be made aware of that phase. But I haven't actually tried those changes myself.

[1] https://github.com/apache/groovy/blob/master/src/test/groovy/bugs/Groovy6086Bug.groovy#L63

[2] https://github.com/apache/groovy/blob/master/src/test/groovy/bugs/Groovy9031.groovy#L33

[3] https://github.com/apache/groovy/blob/master/src/main/java/org/codehaus/groovy/tools/FileSystemCompiler.java#L309-L317