Greetings I am trying to call some functions of a Swift only

Question

Greetings I am trying to call some functions of a Swift only library from Kotlin I am aware that the only way to do this is to define some wrappers available in Objective C and then compile it via Kotlin Native I started experimenting by creating a static library via Xcode defining a Gradle task that runs `xcodebuild workspace MyLibInterop xcworkspace scheme MyLibInterop sdk $sdk configuration Release build SYMROOT=$PWD build OBJROOT=$PWD build` and finally creating a cinterop configuration via Gradle and a def file It works quite well My setup is very similar to the one explained here <https medium com kodein koders create a kotlin multiplatform library with swift 1a818b2dc1b0> the ChachaPoly one However I encounter a problem as soon as I start to add dependencies to this static library I don t know how to tell cinterop where to look for the dependency frameworks used by the static library I used Cocoapods without Gradle to define the dependencies The previous `xcodebuild` command then outputs several framework directories that represent the dependencies in addition to the existing h and a files My exact issue is ``ld warning Could not find or use auto linked framework Amplify ` which is one of the framework directories when running the task `shared linkPodDebugFrameworkIosArm64` I suppose that I have to define a recursive framework search path within my Kotlin cinterop configuration i e the def file I came across the ` F` and ` framework` linker amp compiler options but used them without any success Thank you in anticipation for any kind of help you will be able to provide me with I can provide any info or piece of code you need

Rick Clephas · Answer

How where did you define the ` F` and ` framework` options

Alexandre Gressier · Answer

Thank you for your quick answer I tried several configurations including writing ` F` search paths under `compilerOpts ` in the Gradle build script using the static library and ` framework` flags under `linkerOpts` in my def file

Alexandre Gressier · Answer

To provide you with a bit more context here is the Podfile of the static library ```platform ios 13 0 target AmplifyAuthInterop do use frameworks pod AmplifyPlugins AWSCognitoAuthPlugin end``` Here is the content of the build directory at depth 2 after running `xcodebuild` ```build AWSAuthCore AWSAuthCore framework AWSCognitoIdentityProvider AWSCognitoIdentityProvider framework AWSCognitoIdentityProviderASF AWSCognitoIdentityProviderASF framework AWSCore AWSCore framework AWSMobileClient AWSMobileClient framework AWSPluginsCore AWSPluginsCore framework Amplify Amplify framework AmplifyAuthInterop swiftmodule Project arm64 apple ios abi json arm64 apple ios swiftdoc arm64 apple ios swiftmodule AmplifyPlugins AmplifyPlugins framework Pods AmplifyAuthInterop framework Headers Info plist Modules Pods AmplifyAuthInterop include AmplifyAuthInterop libAmplifyAuthInterop a``` I am not sure if ` F` works recursively so I wrote the following ```kotlin ios val platform = when name iosX64 gt iphonesimulator iosArm64 gt iphoneos else gt error Unsupported target $name compilations getByName main cinterops create AmplifyAuthInterop project shared interop AmplifyAuthInterop let tasks interopProcessingTaskName dependsOn it getTasksByName build$ platform capitalize false first path packageName = interop amplifyauth includeDirs headerFilterOnly $ it buildDir Release $platform include compilerOpts listOf AWSAuthCore AWSCognitoIdentityProvider AWSCognitoIdentityProviderASF AWSCore AWSMobileClient AWSPluginsCore Amplify AmplifyPlugins map framework gt F$ it buildDir Release $platform $framework + F$ it buildDir Release $platform extraOpts libraryPath $ it buildDir Release $platform ``` And I ensured that the framework search paths exist of course

Rick Clephas · Answer

Could you try to specify the search paths in the ` def` file I vaguely remember something about on of these options not being supported from the Gradle task

Rick Clephas · Answer

Scratch that Please try to also set the search paths in the linker options ```kotlin iosX64 binaries all linkerOpts F$frameworkFolder ```

Alexandre Gressier · Answer

Thank you for putting me on the right path Rick I was able to compile and run my project successfully I ended up not using this `binaries` block but I ll leave the following notes for future reference I m almost certain that you are referring to `warning linker option s linkerOpts option is not supported by cinterop Please add linker options to def file or binary compilation instead ` I suppose it would be fine in the `binaries` block though as opposed to the `cinterop` one I ended up writing most of my configuration in my def file instead of the Gradle build script I also discovered that I only need to use and ` F` for the imports I write in Swift i e only `Amplify` Here it is ```package = interop amplifyauth language = Objective C Headers headers = AmplifyAuthInterop AmplifyAuthInterop Swift h headerFilter = AmplifyAuthInterop Libraries staticLibraries = libAmplifyAuthInterop a libraryPaths ios arm64 = Users alex Projects MyProject shared interop AmplifyAuthInterop build Release iphoneos libraryPaths ios x64 = Users alex Projects MyProject shared interop AmplifyAuthInterop build Release iphonesimulator Linker linkerOpts = L usr lib swift linkerOpts ios arm64 = iphoneos version min 16 0 0 L Applications Xcode app Contents Developer Toolchains XcodeDefault xctoolchain usr lib swift iphoneos F Users alex Projects MyProject shared interop AmplifyAuthInterop build Release iphoneos Amplify linkerOpts ios x64 = ios simulator version min 16 0 0 L Applications Xcode app Contents Developer Toolchains XcodeDefault xctoolchain usr lib swift iphonesimulator F Users alex Projects MyProject shared interop AmplifyAuthInterop build Release iphonesimulator Amplify``` And here is the Gradle build script ```kotlin ios val platform = when name iosX64 gt iphonesimulator iosArm64 gt iphoneos else gt error Unsupported target $name compilations getByName main cinterops create AmplifyAuthInterop project shared interop AmplifyAuthInterop let tasks interopProcessingTaskName dependsOn it getTasksByName build$ platform capitalize false first path includeDirs headerFilterOnly $ it buildDir Release $platform include ``` I initially forgot to add a Copy Files build phase to copy `Amplify framework` in the Frameworks directory of my app After that it ran successfully There are still nasty absolute paths in my def file but I don t mind for the time being Thank you again for your precious help

Rick Clephas · Answer

Nice Yeah that s indeed the warning I was referring to Regarding the absolute paths you could create a tasks that generates the correct def file Another note about the cinterop it runs in the final Kotlin module E g it will run in the client project if you distribute your code as a library