Here's small question. I'm trying to consume libcl...

# kotlin-native

[r4zzz4k]

Here's small question. I'm trying to consume libclang from K/N code. There is a function called clang_visitChildren which expects callback having C structs passed by values as parameters. When trying to use it as is, I'm getting the following error: type CValue<CXCursor> is not supported in callback signature.
Do I understand correctly that the following workaround is the only way to go for now?

[svyatoslav.scherbina]

Unfortunately, yes, in this case you need to add callback wrapper. You can add C code at the end of .def file after `---`:
https://github.com/JetBrains/kotlin-native/blob/master/INTEROP.md#adding-custom-declarations

Also you can make CallbackWithPtrs receive some user data using the following:

...
// [C++] My wrapper
typedef void (*CallbackWithPtrs) (Input*, void* userData);

struct WrapperCallbackUserData {
    CallbackWithPtrs callback;
    void* userData;
}

void WrapperCallback(Input input, void* userData) {
    WrapperCallbackUserData* data = (WrapperCallbackUserData*) userData;
    CallbackWithPtrs actualCallback = data->callback;
    actualCallback(&input, data->userData);
}

void wrapperVisitor(CallbackWithPtrs callback, void* userData) {
    struct WrapperCallbackUserData data;
    data.callback = callback;
    data.userData = userData;
    visitor(WrapperCallback, (void*) &data);
}         

// [Kotlin/Native] Wrapper usage
wrapperVisitor(staticCFunction({ input: CPointer<Input>, userData: COpaquePointer ->
    // use input.pointed
}))

[r4zzz4k]

Oh, I forgot about the feature with C code in .def file.
Yeah, I've decided to skip userData from example for simplicity. I'm going to use it with StableObjPtr in my own code, of course.

Thank you very much!