Is there any place I can learn how to use `depends...

# kotlin-native

[r4zzz4k]

Is there any place I can learn how to use depends directive of .def file? I was skimming through the repo but didn't find any usage outside of default platform libs generation.
Reasoning for the question: I'm trying to consume from Kotlin/Native two C libraries which depend on each other. Bindings for the first one are generated trivially, but I'm unable to inform cinterop that for types and functions from the first library there should be imports with first lib wrapper's namespace instead of duplicated bridges.

[svyatoslav.scherbina]

depends property value should contain space-separated list of library names. This names are resolved as described in the documentation: https://github.com/JetBrains/kotlin-native/blob/master/LIBRARIES.md#library-search-sequence

[r4zzz4k]

And cinterop uses this property only to add these to final .klib dependencies, but not to actually emit any stubs code?
For example, platform.linux depends on platform.posix and there is, for example, the following function:
kfun:platform.linux.inet_makeaddr(<http://kotlin.Int;kotlin.Int|kotlin.Int;kotlin.Int>)kotlinx.cinterop.CValue<platform.posix.in_addr>. So function from platform.linux contains reference to type from platform.posix. I'm trying to achieve the same thing, but for me cinterop for the second library generates all the types for the second time under new package instead of referencing them from the first klib. I've enumerated all the headers of the second library in headerFilter and mentioned the first one in depends, but it's not working for me, unfortunately.

[r4zzz4k]

Here's what I'm trying to do in a nutshell.
https://gist.github.com/r4zzz4k/3d3ac8b6ace1743fb2bc1db23785e0a2
Prerequisites: Linux, apt install libglib2.0-dev libgirepository1.0-dev.
Resulting `gir_interop-build/manifest.properties`contains proper depends= field, everything else seems okay there, but both gobj_interop-build/kotlin/sample/gobj/cinterop/cinterop.kt and gir_interop-build/kotlin/sample/gir/cinterop/cinterop.kt contain their own definition of class _GObject(rawPtr: NativePtr) : CStructVar(rawPtr) { under corresponding packages, when I'm trying to achieve one class as sample.gobj.cinterop._GObject and for second library import sample.gir.cinterop.* or something along those lines instead.

[msink]

Maybe something like -library gobj option needed for second cinterop

[r4zzz4k]

@msink, you're life saver. I don't even know why I didn't try that as platformLibs/build.gradle clearly does take depends from DefFile and passes it as libraries to interop configuration. Thank you, it works!

[r4zzz4k]

Though it seems kind of logical to do that by cinterop itself than by external Gradle task -- I'm not sure I see any use-cases when klib should depend on another one but shouldn't use it's contents.
Should I file an issue against kotlin-native repo for you to consider this, @svyatoslav.scherbina?

[svyatoslav.scherbina]

@msink yes, you are right.
@r4zzz4k sorry for giving you wrong advice.
With passing -library options to cinterop it doesn’t seem necessary to add depends = to .def file.

Though it seems kind of logical to do that by cinterop itself than by external Gradle task

What do you mean? cinterop itself supports dependencies between C libraries through -library option.

[r4zzz4k]

Oh, I didn't check if depends is necessary in presence of -library.
So let me ask another question: what are use cases for having depends field without -library flag? If I understand correctly, it would create dependency without providing any actual communication between libraries.

[r4zzz4k]

Giving another thought, this can probably be useful for having some plugin system. E.g., there are:
• plugin-base with registration and plugin API functions
• plugin-a with -library plugin-base
• app with -library plugin-base and depends plugin-a for statically embedding it into the final artifact.
This way app does use actual plugin, but via common dependency. So disregard that, it's perfectly fine to have it the way you do, it was just my misunderstanding.

[svyatoslav.scherbina]

what are use cases for having depends field without -library flag?

Currently depends is for internal use only, e.g. to prepare platform libs.

[r4zzz4k]

I see, thanks.