Hi everyone! I’m new to the Kotlin slack and would like to create an OpenRewrite AST for Kotlin. I w...

# getting-started

[Tracey Yoshima]

Hi everyone! I’m new to the Kotlin slack and would like to create an OpenRewrite AST for Kotlin.
I want to use the Kotlin compiler to collect the type attribution of Kotlin and Java sources.
The goal is primarily to have a Kotlin AST that will allow us to migrate APIs.

I’m having trouble creating a FirSessionFactory.INSTANCE using createLibrarySession and am getting an error (will be linked in thread).

Could someone point me to an example of how to instantiate the Kotlin compiler?

[Tracey Yoshima]

I’m not sure what I’m doing wrong. Error:

java.lang.IllegalStateException: Module data is not registered in Libraries session
	at org.jetbrains.kotlin.fir.FirModuleDataKt.getModuleData(FirModuleData.kt)
	at org.jetbrains.kotlin.fir.builder.BaseFirBuilder.<init>(BaseFirBuilder.kt:50)
	at org.jetbrains.kotlin.fir.builder.BaseFirBuilder.<init>(BaseFirBuilder.kt:49)
	at org.jetbrains.kotlin.fir.builder.RawFirBuilder.<init>(RawFirBuilder.kt:55)
...

[Tracey Yoshima]

Code snippet.java

Code snippet.java

[Tracey Yoshima]

Thanks in advance!

[dmitriy.novozhilov]

You can check how FIR compiler is set up in tests, for example (just creating of empty library session is not enough)

[dmitriy.novozhilov]

Also it's better to ask questions about compiler internals in #compiler channel

[Tracey Yoshima]

Thank you @dmitriy.novozhilov!