I need to call `__android_log_print()` in `androi...

# kotlin-native

[Edoardo Luppi]

I need to call __android_log_print() in androidNativeMain.
The function signature is

__android_log_print(prio: <http://kotlin.Int|kotlin.Int>, tag: kotlin.String?, fmt: kotlin.String?, vararg variadicArguments: kotlin.Any?): <http://kotlin.Int|kotlin.Int>

But I don't understand if variadicArguments expects a Kotlin type, like String, or if I should convert to the C representation with cstr

[Andrey]

You can use this in any way you like

val num = 128736912873
println("println tes")
__android_log_print(ANDROID_LOG_ERROR.convert(), "Konan_main", "__android_log_print test $num")

[Edoardo Luppi]

Ah nice, so the template %s part isn't even needed after all.

[Edoardo Luppi]

Thanks for the test! I don't even have an Android test setup as I don't do Android development

[Edoardo Luppi]

Is Konan_main strictly necessary?

[Andrey]

No, this is the name of the key that is used by default for println

[ephemient]

tags make it easier to filter in logcat, e.g.

adb logcat -s MyApp:*

only shows messages logged with tag MyApp

[Edoardo Luppi]

Perfect, thanks. I've tagged it with my own tag.

[ephemient]

but yes to your original question, if you're calling a C function you need to pass along C types in the varargs

[Edoardo Luppi]

It's just confusing because the tag and fmt parameter accepts a String, not a C string.

[ephemient]

it's possible to specify noStringConversion in the .def file, and then that doesn't happen automatically. but afaik it doesn't happen automatically for varargs, since they aren't typed

[ephemient]

to Andrey's point though, it'll be easier to do the formatting in Kotlin

[Edoardo Luppi]

Yeah I ended up replacing the format argument with the actual message
https://github.com/Strumenta/antlr-kotlin/pull/184/files#diff-64e801a9e2c70c7f85610b239de51584efabdfe5b3f8cddd37842a994372e9fe

[Edoardo Luppi]

Thank you!