Kotlin/Native can't use T::class in inline function of @Composable for iOS

[eymar]

Describe the bug

Affected platforms
Select one of the platforms below:

• iOS

Versions

• Kotlin version*: 1.8.20
• Compose Multiplatform version*: 1.4.0

To Reproduce

@Composable
inline fun <reified T : ViewModel> getViewModel(
    key: Any,
    noinline viewModelBlock: () -> T
): T = getViewModel(key, T::class, viewModelBlock)

[ryanmitchener]

This is also affecting me with Kotlin 1.9.0 and Compose multiplatform 1.5.0. This was a difficult bug to track down as the offending code was contained in a KMP library. It would be great if this could be resolved in the near future!

[hoc081098]

I have the same issue

@OptIn(ExperimentalObjCRefinement::class)
@HiddenFromObjC
inline fun <reified T : Route> routeContent(
  noinline content: @Composable (route: T) -> Unit,
): RouteContent<T> =
  object : RouteContent<T> {
    override val id: RouteContent.Id<T> = RouteContent.Id(T::class)

    @Composable
    override fun Content(route: T) = content(route)
  }

[ryanmitchener]

@hoc081098 I was able to work around the issue by making a helper function that was not composable. It may or may not work in your situation.

@Composable
inline fun <reified T : Any> doSomething() =
    doSomethingWithReifiedType(getKClassForGenericType<T>())

@Composable
inline fun <reified T : Any> doSomethingWithReifiedType(clazz: KClass<T>) {
    // Do something
}

// Helper to get around @Composable inlined reified types
inline fun <reified T : Any> getKClassForGenericType(): KClass<T> = T::class

[hoc081098]

@hoc081098 I was able to work around the issue by making a helper function that was not composable. It may or may not work in your situation.

@Composable
inline fun <reified T : Any> doSomething() =
    doSomethingWithReifiedType(getKClassForGenericType<T>())

@Composable
inline fun <reified T : Any> doSomethingWithReifiedType(clazz: KClass<T>) {
    // Do something
}

// Helper to get around @Composable inlined reified types
inline fun <reified T : Any> getKClassForGenericType(): KClass<T> = T::class

Thanks, I have just used this way to workaround this issue

[rockiedo]

Hi @eymar, may I know how you found out the root cause? I'm facing the same problem but having no clue when looking at the build errors.

[taetae98coding]

Hi @ryanmitchener thank you for your comment.

I had same issue. But I solved it with your comment. And now I don't know why it solved can you explain?? 🥲

[ryanmitchener]

@taetae98coding As far as I understand it, the only limitation is that you can't use T::class in a @Composable inline function. The workaround makes a separate function that is inline but not @Composable. The compiler does not have an issue with that. From there, you can use that function in any @Composable function.

[taetae98coding]

@ryanmitchener thank you!

[fbarthelery]

I got the same issue on Kotlin/web

Affected platforms

• Web (K/JS)

Versions

• Kotlin version: 1.9.22
• Compose Multiplatform version: 1.6.0

To Reproduce

inline fun <reified VM: Any> viewModel(): VM {
    return VM::class as VM
}

Stacktrace

e: java.lang.IllegalStateException: Symbol for [ compose.viewmodel/viewModel|viewModel(compose.viewmodel.ViewModelStoreOwner;kotlin.String?){0§<kotlin.Any>}[0] <- Local[<TP>,0|TYPE_PARAMETER name:VM index:0 variance: superTypes:[kotlin.Any] reified:true] ] is unbound
	at org.jetbrains.kotlin.ir.symbols.impl.IrBindablePublicSymbolBase.getOwner(IrPublicSymbolBase.kt:63)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartiallyLinkedIrTreePatcher$ExpressionTransformer.checkReferencedDeclaration(PartiallyLinkedIrTreePatcher.kt:585)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartiallyLinkedIrTreePatcher$ExpressionTransformer.checkReferencedDeclaration$default(PartiallyLinkedIrTreePatcher.kt:574)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartiallyLinkedIrTreePatcher$ExpressionTransformer.visitClassReference(PartiallyLinkedIrTreePatcher.kt:492)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitClassReference(IrElementTransformerVoid.kt:254)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitClassReference(IrElementTransformerVoid.kt:24)
	at org.jetbrains.kotlin.ir.expressions.IrClassReference.accept(IrClassReference.kt:26)
	at org.jetbrains.kotlin.ir.expressions.IrExpression.transform(IrExpression.kt:31)
	at org.jetbrains.kotlin.ir.expressions.IrExpression.transform(IrExpression.kt:22)
	at org.jetbrains.kotlin.ir.util.TransformKt.transformInPlace(transform.kt:45)
	at org.jetbrains.kotlin.ir.expressions.IrMemberAccessExpression.transformChildren(IrMemberAccessExpression.kt:50)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoidKt.transformChildrenVoid(IrElementTransformerVoid.kt:346)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartiallyLinkedIrTreePatcher$ExpressionTransformer.visitCall(PartiallyLinkedIrTreePatcher.kt:1322)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitCall(IrElementTransformerVoid.kt:215)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitCall(IrElementTransformerVoid.kt:24)
	at org.jetbrains.kotlin.ir.expressions.IrCall.accept(IrCall.kt:26)
	at org.jetbrains.kotlin.ir.expressions.IrExpression.transform(IrExpression.kt:31)
	at org.jetbrains.kotlin.ir.declarations.IrVariable.transformChildren(IrVariable.kt:45)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitDeclaration(IrElementTransformerVoid.kt:57)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartiallyLinkedIrTreePatcher$ExpressionTransformer.visitDeclaration(PartiallyLinkedIrTreePatcher.kt:462)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitVariable(IrElementTransformerVoid.kt:101)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitVariable(IrElementTransformerVoid.kt:102)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitVariable(IrElementTransformerVoid.kt:24)
	at org.jetbrains.kotlin.ir.declarations.IrVariable.accept(IrVariable.kt:38)
	at org.jetbrains.kotlin.ir.IrElementBase.transform(IrElementBase.kt:24)
	at org.jetbrains.kotlin.ir.util.TransformKt.transformInPlace(transform.kt:35)
	at org.jetbrains.kotlin.ir.expressions.IrBlockBody.transformChildren(IrBlockBody.kt:32)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitBody(IrElementTransformerVoid.kt:108)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitBlockBody(IrElementTransformerVoid.kt:117)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartiallyLinkedIrTreePatcher$ExpressionTransformer.visitBlockBody(PartiallyLinkedIrTreePatcher.kt:467)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitBlockBody(IrElementTransformerVoid.kt:118)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitBlockBody(IrElementTransformerVoid.kt:24)
	at org.jetbrains.kotlin.ir.expressions.IrBlockBody.accept(IrBlockBody.kt:25)
	at org.jetbrains.kotlin.ir.expressions.IrBody.transform(IrBody.kt:22)
	at org.jetbrains.kotlin.ir.declarations.IrFunction.transformChildren(IrFunction.kt:62)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitDeclaration(IrElementTransformerVoid.kt:57)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartiallyLinkedIrTreePatcher$ExpressionTransformer.visitDeclaration(PartiallyLinkedIrTreePatcher.kt:462)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitFunction(IrElementTransformerVoid.kt:69)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitSimpleFunction(IrElementTransformerVoid.kt:72)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitSimpleFunction(IrElementTransformerVoid.kt:73)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitSimpleFunction(IrElementTransformerVoid.kt:24)
	at org.jetbrains.kotlin.ir.declarations.IrSimpleFunction.accept(IrSimpleFunction.kt:37)
	at org.jetbrains.kotlin.ir.IrElementBase.transform(IrElementBase.kt:24)
	at org.jetbrains.kotlin.ir.util.TransformKt.transformInPlace(transform.kt:35)
	at org.jetbrains.kotlin.ir.declarations.IrFile.transformChildren(IrFile.kt:41)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitPackageFragment(IrElementTransformerVoid.kt:41)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartiallyLinkedIrTreePatcher$ExpressionTransformer.visitPackageFragment(PartiallyLinkedIrTreePatcher.kt:453)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitFile(IrElementTransformerVoid.kt:47)
	at org.jetbrains.kotlin.backend.common.linkage.partial.FileAwareIrElementTransformerVoid.access$visitFile$s-1784493990(PartialLinkageUtils.kt:82)
	at org.jetbrains.kotlin.backend.common.linkage.partial.FileAwareIrElementTransformerVoid$visitFile$1.invoke(PartialLinkageUtils.kt:97)
	at org.jetbrains.kotlin.backend.common.linkage.partial.FileAwareIrElementTransformerVoid$visitFile$1.invoke(PartialLinkageUtils.kt:96)
	at org.jetbrains.kotlin.backend.common.linkage.partial.FileAwareIrElementTransformerVoid.runInFile(PartialLinkageUtils.kt:90)
	at org.jetbrains.kotlin.backend.common.linkage.partial.FileAwareIrElementTransformerVoid.visitFile(PartialLinkageUtils.kt:96)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitFile(IrElementTransformerVoid.kt:48)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitFile(IrElementTransformerVoid.kt:24)
	at org.jetbrains.kotlin.ir.declarations.IrFile.accept(IrFile.kt:31)
	at org.jetbrains.kotlin.ir.declarations.IrFile.transform(IrFile.kt:34)
	at org.jetbrains.kotlin.ir.declarations.IrFile.transform(IrFile.kt:22)
	at org.jetbrains.kotlin.ir.util.TransformKt.transformInPlace(transform.kt:35)
	at org.jetbrains.kotlin.ir.declarations.IrModuleFragment.transformChildren(IrModuleFragment.kt:52)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitModuleFragment(IrElementTransformerVoid.kt:33)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitModuleFragment(IrElementTransformerVoid.kt:38)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitModuleFragment(IrElementTransformerVoid.kt:24)
	at org.jetbrains.kotlin.ir.declarations.IrModuleFragment.accept(IrModuleFragment.kt:42)
	at org.jetbrains.kotlin.ir.declarations.IrModuleFragment.transform(IrModuleFragment.kt:45)
	at org.jetbrains.kotlin.ir.declarations.IrModuleFragment.transform(IrModuleFragment.kt:26)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartiallyLinkedIrTreePatcher.transformVoid(PartiallyLinkedIrTreePatcher.kt:87)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartiallyLinkedIrTreePatcher.patchModuleFragments(PartiallyLinkedIrTreePatcher.kt:68)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartialLinkageSupportForLinkerImpl$generateStubsAndPatchUsages$1.invoke(PartialLinkageSupportForLinkerImpl.kt:62)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartialLinkageSupportForLinkerImpl$generateStubsAndPatchUsages$1.invoke(PartialLinkageSupportForLinkerImpl.kt:62)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartialLinkageSupportForLinkerImpl.generateStubsAndPatchUsagesInternal(PartialLinkageSupportForLinkerImpl.kt:80)
	at org.jetbrains.kotlin.backend.common.linkage.partial.PartialLinkageSupportForLinkerImpl.generateStubsAndPatchUsages(PartialLinkageSupportForLinkerImpl.kt:62)
	at org.jetbrains.kotlin.backend.common.serialization.KotlinIrLinker.postProcess(KotlinIrLinker.kt:231)
	at org.jetbrains.kotlin.ir.backend.js.KlibKt.getIrModuleInfoForKlib(klib.kt:305)
	at org.jetbrains.kotlin.ir.backend.js.KlibKt.loadIr(klib.kt:242)
	at org.jetbrains.kotlin.ir.backend.js.CompilerKt.compile(compiler.kt:54)
	at org.jetbrains.kotlin.ir.backend.js.CompilerKt.compile$default(compiler.kt:39)
	at org.jetbrains.kotlin.cli.js.K2JsIrCompiler$Ir2JsTransformer.lowerIr(K2JsIrCompiler.kt:103)
	at org.jetbrains.kotlin.cli.js.K2JsIrCompiler$Ir2JsTransformer.makeJsCodeGenerator(K2JsIrCompiler.kt:125)
	at org.jetbrains.kotlin.cli.js.K2JsIrCompiler$Ir2JsTransformer.compileAndTransformIrNew(K2JsIrCompiler.kt:133)
	at org.jetbrains.kotlin.cli.js.K2JsIrCompiler.doExecute(K2JsIrCompiler.kt:391)
	at org.jetbrains.kotlin.cli.js.K2JSCompiler.doExecute(K2JSCompiler.java:181)
	at org.jetbrains.kotlin.cli.js.K2JSCompiler.doExecute(K2JSCompiler.java:72)
	at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:104)
	at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:48)
	at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:101)
	at org.jetbrains.kotlin.daemon.CompileServiceImpl.compile(CompileServiceImpl.kt:1523)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at java.rmi/sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:360)
	at java.rmi/sun.rmi.transport.Transport$1.run(Transport.java:200)
	at java.rmi/sun.rmi.transport.Transport$1.run(Transport.java:197)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:712)
	at java.rmi/sun.rmi.transport.Transport.serviceCall(Transport.java:196)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:587)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:828)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:705)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:704)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.lang.Thread.run(Thread.java:833)

[oblakr24]

This issue still occurs on Kotlin native when building for iOS, versions:

compose-plugin = "1.6.0"
kotlin = "1.9.22"

The workaround I did is to have a separate non-composable inline function which takes the reified parameter and returns the result (i.e. a string value of the name etc.).