How can I get the declaration of a `KtElement` using the kotlin compiler api? When I try to access `...

# compiler

[Fudge]

How can I get the declaration of a KtElement using the kotlin compiler api? When I try to access `getReference()`/`getReferences()` all I get is null / empty list. I'm assuming there's some extra configuration I need to do, because calls to resolve references go through this call:

ServiceManager.getService(KotlinReferenceProvidersService::class.java) ?: NO_REFERENCES_SERVICE

And the left hand side is always null.

[shikasd]

Do you want to find the element reference is connected to?

[Fudge]

Given a method call

fun main() {
  val x = Foo()
  x.bar() <----
}

I want to see where bar is defined and what class owns it.

[shikasd]

this reference is usually connected to call or resolvedCall , which can point you to descriptor of the function and class, so you can use them
iirc, compiler has getResolvedCall() extension for expressions

[shikasd]

note that they are available only when analysis is completed 🙂

[Fudge]

@shikasd How can I get an instance of BindingContext for call and resolvedCall?

[Fudge]

I managed to get an instance of TopDownAnalysisContext , is there some way to go from there to a BindingContext ?

[shikasd]

depends on the extension you are in 🙂
if you have binding trace, you should be good to go

[Fudge]

I'm not writing a compiler plugin, I'm using the compiler API to do a transformation on kotlin source, and I've followed this example for the basic setup
https://github.com/vektory79/kotlin-script-parser-test/blob/master/src/main/java/hello/CompileTest.kt
and I've also made some changes to make it compile since it seems the api changed slightly
https://hastebin.com/sakowujopo.java

[shikasd]

You can use componentProvider to get BindingTrace type
It contains BindingContext and also allows you to modify it 🙂

[shikasd]

Note that you still need to run analyzer before accessing BindingContext, as otherwise it will be empty

[Fudge]

Aha! This is what I need! Thank you very much!

[shikasd]

yep, it is similar
you have property descriptor and KotlinType
you can use KotlinType to get class descriptor out of it

[Fudge]

how do I get a KotlinType from a KtTypeReference and a property descriptor from `KtProperty`(I think that's the right type for properties)?

[Fudge]

Or whatever the correct KtElement is, i'm not sure which it is

[Fudge]

ok I found getAbbreviatedTypeOrType

[Fudge]

Hmm... it seems i'm getting UnresolvedType errors when using types defined in the classpath... Solving that probably won't be fun

[shikasd]

It is available from binding context as well, I don't remember exact properties
you should also include types from the classpath, I guess, not sure how you are compiling those atm 🙂

[Fudge]

I am including types from the classpath like so

configuration.addJvmClasspathRoots(classPath.map { it.toFile() })

The full code is here https://hasteb.in/eqahijib.kotlin, is there anything I'm missing for including types?

[Fudge]

classpath includes a jar which defines the types

[shikasd]

Seems like it is a bit different in the compiler code
See https://github.com/JetBrains/kotlin/blob/c9e423bf641249cfa2c1f2b12c4c0f28808816af/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/K2JVMCompiler.kt#L178
The are using module impl to do so.