Kotlin Inject interop: crash when using val for provides

[gabrielittner]

Description

Having something like the following in Kotlin Inject with interop enabled will result in Metro failing:

public val ImplementationType.bind: BoundType
    @Provides get() = this

Exception:

e: java.lang.IllegalStateException: Expected 2 arguments but got 1 for function: dev.zacsweers.metro.sample.KotlinInjectTest.SimpleComponent.<get-bind>
        at dev.zacsweers.metro.compiler.ir.IrKt.irInvoke(ir.kt:339)
        at dev.zacsweers.metro.compiler.ir.IrKt.irInvoke$default(ir.kt:294)
        at dev.zacsweers.metro.compiler.ir.transformers.BindingContainerTransformer.implementCreatorBodies$lambda$1(BindingContainerTransformer.kt:553)
        at dev.zacsweers.metro.compiler.ir.transformers.FactoryIrUtilKt.generateStaticNewInstanceFunction(factoryIrUtil.kt:151)
        at dev.zacsweers.metro.compiler.ir.transformers.BindingContainerTransformer.implementCreatorBodies(BindingContainerTransformer.kt:528)
        at dev.zacsweers.metro.compiler.ir.transformers.BindingContainerTransformer.getOrLookupProviderFactory(BindingContainerTransformer.kt:347)
        at dev.zacsweers.metro.compiler.ir.transformers.BindingContainerTransformer.visitProperty(BindingContainerTransformer.kt:234)
        at dev.zacsweers.metro.compiler.ir.transformers.BindingContainerTransformer.findContainer(BindingContainerTransformer.kt:163)
        at dev.zacsweers.metro.compiler.ir.transformers.BindingContainerTransformer.findContainer$default(BindingContainerTransformer.kt:132)
        at dev.zacsweers.metro.compiler.ir.transformers.DependencyGraphTransformer.visitClassNew(DependencyGraphTransformer.kt:179)
        at org.jetbrains.kotlin.backend.common.IrElementTransformerVoidWithContext.visitClass(IrElementTransformerVoidWithContext.kt:62)
        at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitClass(IrElementTransformerVoid.kt:57)
        at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitClass(IrElementTransformerVoid.kt:19)
        at org.jetbrains.kotlin.ir.declarations.IrClass.accept(IrClass.kt:72)
        at org.jetbrains.kotlin.ir.IrElementBase.transform(IrElementBase.kt:33)
        at org.jetbrains.kotlin.ir.util.TransformKt.transformInPlace(transform.kt:35)
        at org.jetbrains.kotlin.ir.declarations.IrClass.transformChildren(IrClass.kt:82)
        at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitDeclaration(IrElementTransformerVoid.kt:40)
        at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitClass(IrElementTransformerVoid.kt:54)
        at org.jetbrains.kotlin.backend.common.IrElementTransformerVoidWithContext.visitClassNew(IrElementTransformerVoidWithContext.kt:126)
        at dev.zacsweers.metro.compiler.ir.transformers.DependencyGraphTransformer.visitClassNew(DependencyGraphTransformer.kt:183)
        at org.jetbrains.kotlin.backend.common.IrElementTransformerVoidWithContext.visitClass(IrElementTransformerVoidWithContext.kt:62)
        at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitClass(IrElementTransformerVoid.kt:57)
        at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitClass(IrElementTransformerVoid.kt:19)
        at org.jetbrains.kotlin.ir.declarations.IrClass.accept(IrClass.kt:72)
        at org.jetbrains.kotlin.ir.IrElementBase.transform(IrElementBase.kt:33)
        at org.jetbrains.kotlin.ir.util.TransformKt.transformInPlace(transform.kt:35)
        at org.jetbrains.kotlin.ir.declarations.IrPackageFragment.transformChildren(IrPackageFragment.kt:31)
        at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitPackageFragment(IrElementTransformerVoid.kt:146)
        at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitFile(IrElementTransformerVoid.kt:160)
        at org.jetbrains.kotlin.backend.common.IrElementTransformerVoidWithContext.visitFileNew(IrElementTransformerVoidWithContext.kt:122)
        at org.jetbrains.kotlin.backend.common.IrElementTransformerVoidWithContext.visitFile(IrElementTransformerVoidWithContext.kt:55)
        at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitFile(IrElementTransformerVoid.kt:163)
        at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitFile(IrElementTransformerVoid.kt:19)
        at org.jetbrains.kotlin.ir.declarations.IrFile.accept(IrFile.kt:27)
        at org.jetbrains.kotlin.ir.declarations.IrFile.transform(IrFile.kt:30)
        at org.jetbrains.kotlin.ir.declarations.IrFile.transform(IrFile.kt:19)
        at org.jetbrains.kotlin.ir.util.TransformKt.transformInPlace(transform.kt:35)
        at org.jetbrains.kotlin.ir.declarations.IrModuleFragment.transformChildren(IrModuleFragment.kt:46)
        at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitModuleFragment(IrElementTransformerVoid.kt:102)
        at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitModuleFragment(IrElementTransformerVoid.kt:107)
        at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitModuleFragment(IrElementTransformerVoid.kt:19)
        at org.jetbrains.kotlin.ir.declarations.IrModuleFragment.accept(IrModuleFragment.kt:36)
        at org.jetbrains.kotlin.ir.declarations.IrModuleFragment.transform(IrModuleFragment.kt:39)
        at dev.zacsweers.metro.compiler.ir.MetroIrGenerationExtension.generateInner(MetroIrGenerationExtension.kt:71)
        at dev.zacsweers.metro.compiler.ir.MetroIrGenerationExtension.generate(MetroIrGenerationExtension.kt:44)
        at org.jetbrains.kotlin.fir.pipeline.ConvertToIrKt.applyIrGenerationExtensions(convertToIr.kt:498)
        at org.jetbrains.kotlin.fir.pipeline.Fir2IrPipeline.runActualizationPipeline(convertToIr.kt:253)
        at org.jetbrains.kotlin.fir.pipeline.Fir2IrPipeline.convertToIrAndActualize(convertToIr.kt:134)
        at org.jetbrains.kotlin.fir.pipeline.ConvertToIrKt.convertToIrAndActualize(convertToIr.kt:100)
        at org.jetbrains.kotlin.fir.pipeline.ConvertToIrKt.convertToIrAndActualize$default(convertToIr.kt:73)
        at org.jetbrains.kotlin.cli.jvm.compiler.legacy.pipeline.JvmCompilerPipelineKt.convertToIrAndActualizeForJvm(jvmCompilerPipeline.kt:101)
        at org.jetbrains.kotlin.cli.pipeline.jvm.JvmFir2IrPipelinePhase.executePhase(JvmFir2IrPipelinePhase.kt:30)
        at org.jetbrains.kotlin.cli.pipeline.jvm.JvmFir2IrPipelinePhase.executePhase(JvmFir2IrPipelinePhase.kt:25)
        at org.jetbrains.kotlin.cli.pipeline.jvm.JvmFir2IrPipelinePhase.executePhase(JvmFir2IrPipelinePhase.kt:19)
        at org.jetbrains.kotlin.cli.pipeline.PipelinePhase.phaseBody(PipelinePhase.kt:68)
        at org.jetbrains.kotlin.cli.pipeline.PipelinePhase.phaseBody(PipelinePhase.kt:58)
        at org.jetbrains.kotlin.config.phaser.NamedCompilerPhase.invoke(CompilerPhase.kt:102)
        at org.jetbrains.kotlin.backend.common.phaser.CompositePhase.invoke(PhaseBuilders.kt:22)
        at org.jetbrains.kotlin.config.phaser.CompilerPhaseKt.invokeToplevel(CompilerPhase.kt:53)
        at org.jetbrains.kotlin.cli.pipeline.AbstractCliPipeline.runPhasedPipeline(AbstractCliPipeline.kt:109)
        at org.jetbrains.kotlin.cli.pipeline.AbstractCliPipeline.execute(AbstractCliPipeline.kt:68)
        at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecutePhased(K2JVMCompiler.kt:79)
        at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecutePhased(K2JVMCompiler.kt:45)
        at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:90)
        at org.jetbrains.kotlin.cli.common.CLICompiler.exec(CLICompiler.kt:352)
        at org.jetbrains.kotlin.incremental.IncrementalJvmCompilerRunnerBase.runCompiler(IncrementalJvmCompilerRunnerBase.kt:176)
        at org.jetbrains.kotlin.incremental.IncrementalJvmCompilerRunnerBase.runCompiler(IncrementalJvmCompilerRunnerBase.kt:39)
        at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.doCompile(IncrementalCompilerRunner.kt:499)
        at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compileImpl(IncrementalCompilerRunner.kt:416)
        at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compileNonIncrementally(IncrementalCompilerRunner.kt:301)
        at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compile(IncrementalCompilerRunner.kt:128)
        at org.jetbrains.kotlin.daemon.CompileServiceImplBase.execIncrementalCompiler(CompileServiceImpl.kt:684)
        at org.jetbrains.kotlin.daemon.CompileServiceImplBase.access$execIncrementalCompiler(CompileServiceImpl.kt:94)
        at org.jetbrains.kotlin.daemon.CompileServiceImpl.compile(CompileServiceImpl.kt:1810)
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
        at java.base/java.lang.reflect.Method.invoke(Method.java:580)
        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$1.run(Transport.java:197)
        at java.base/java.security.AccessController.doPrivileged(AccessController.java:714)
        at java.rmi/sun.rmi.transport.Transport.serviceCall(Transport.java:196)
        at java.rmi/sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:598)
        at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:844)
        at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:721)
        at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
        at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:720)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
        at java.base/java.lang.Thread.run(Thread.java:1575)

Self-contained Reproducer

main...gabrielittner:metro:kotlin-inject-bining-issue

Metro version

0.9.2

Context

I've seen a mention in the differences docs that mentions the get() = this not being necessary with Metro, but I couldn't find a mention that this is not supported for interop. Having it supported would be great, so that we don't need to convert all of these to functions initially (and then back to val with @Binds when we actually start using Metro's annotations). If it won't be supported, it would be nice to at least have a proper error message.

[ZacSweers]

Not actually an interop issue, it fails the same way with just pure metro annotations:

interface BoundType
class ImplementationType : BoundType

interface Bindings {
  public val ImplementationType.bind: BoundType
    @Provides get() = this
}

However, right now metro doesn't support extension receivers on providers. Only @Binds. The error here should be getting caught in FIR, I'll look into that.

[ZacSweers]

actually looks like it is warning

I may just need to promote this to an error for now. It's pretty weedy to get extension receivers working for providers :/