JVM Compiler error after upgrading to 1.5.30

Describe the bug

I’m getting a compiler error after upgrading to Kotlin 1.5.30:

e: org.jetbrains.kotlin.backend.common.BackendException: Backend Internal error: Exception during IR lowering
File being compiled: C:/Users/jimne/Google Drive/My Stuff/spellbook/common/src/commonMain/kotlin/com/rnett/spellbook/spellbook/Spellcasting.kt
The root cause java.lang.RuntimeException was thrown at: org.jetbrains.kotlin.backend.jvm.codegen.FunctionCodegen.generate(FunctionCodegen.kt:50)
	at org.jetbrains.kotlin.backend.common.CodegenUtil.reportBackendException(CodegenUtil.kt:239)
	at org.jetbrains.kotlin.backend.common.CodegenUtil.reportBackendException$default(CodegenUtil.kt:235)
	at org.jetbrains.kotlin.backend.common.phaser.PerformByIrFilePhase.invokeSequential(performByIrFile.kt:68)
	at org.jetbrains.kotlin.backend.common.phaser.PerformByIrFilePhase.invoke(performByIrFile.kt:55)
	at org.jetbrains.kotlin.backend.common.phaser.PerformByIrFilePhase.invoke(performByIrFile.kt:41)
	at org.jetbrains.kotlin.backend.common.phaser.NamedCompilerPhase.invoke(CompilerPhase.kt:96)
	at org.jetbrains.kotlin.backend.common.phaser.CompositePhase.invoke(PhaseBuilders.kt:29)
	at org.jetbrains.kotlin.backend.common.phaser.NamedCompilerPhase.invoke(CompilerPhase.kt:96)
	at org.jetbrains.kotlin.backend.common.phaser.CompositePhase.invoke(PhaseBuilders.kt:29)
	at org.jetbrains.kotlin.backend.common.phaser.NamedCompilerPhase.invoke(CompilerPhase.kt:96)
	at org.jetbrains.kotlin.backend.common.phaser.CompilerPhaseKt.invokeToplevel(CompilerPhase.kt:43)
	at org.jetbrains.kotlin.backend.jvm.JvmIrCodegenFactory.doGenerateFilesInternal(JvmIrCodegenFactory.kt:191)
	at org.jetbrains.kotlin.backend.jvm.JvmIrCodegenFactory.generateModule(JvmIrCodegenFactory.kt:60)
	at org.jetbrains.kotlin.codegen.KotlinCodegenFacade.compileCorrectFiles(KotlinCodegenFacade.java:35)
	at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.generate(KotlinToJVMBytecodeCompiler.kt:321)
	at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules$cli(KotlinToJVMBytecodeCompiler.kt:113)
	at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules$cli$default(KotlinToJVMBytecodeCompiler.kt:56)
	at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:169)
	at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:52)
	at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:92)
	at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:44)
	at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:98)
	at org.jetbrains.kotlin.incremental.IncrementalJvmCompilerRunner.runCompiler(IncrementalJvmCompilerRunner.kt:412)
	at org.jetbrains.kotlin.incremental.IncrementalJvmCompilerRunner.runCompiler(IncrementalJvmCompilerRunner.kt:112)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compileIncrementally(IncrementalCompilerRunner.kt:358)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compileIncrementally$default(IncrementalCompilerRunner.kt:300)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compileImpl$rebuild(IncrementalCompilerRunner.kt:119)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compileImpl(IncrementalCompilerRunner.kt:170)
	at org.jetbrains.kotlin.incremental.IncrementalCompilerRunner.compile(IncrementalCompilerRunner.kt:81)
	at org.jetbrains.kotlin.daemon.CompileServiceImplBase.execIncrementalCompiler(CompileServiceImpl.kt:607)
	at org.jetbrains.kotlin.daemon.CompileServiceImplBase.access$execIncrementalCompiler(CompileServiceImpl.kt:96)
	at org.jetbrains.kotlin.daemon.CompileServiceImpl.compile(CompileServiceImpl.kt:1658)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:564)
	at java.rmi/sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:359)
	at java.rmi/sun.rmi.transport.Transport$1.run(Transport.java:200)
	at java.rmi/sun.rmi.transport.Transport$1.run(Transport.java:197)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:691)
	at java.rmi/sun.rmi.transport.Transport.serviceCall(Transport.java:196)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:587)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:828)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:705)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:704)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
	at java.base/java.lang.Thread.run(Thread.java:832)
Caused by: java.lang.RuntimeException: Exception while generating code for:
FUN name:write$Self visibility:public modality:FINAL <> (self:com.rnett.spellbook.spellbook.Spellbook, output:kotlinx.serialization.encoding.CompositeEncoder, serialDesc:kotlinx.serialization.descriptors.SerialDescriptor) returnType:kotlin.Unit
  annotations:
    JvmStatic
  VALUE_PARAMETER name:self index:0 type:com.rnett.spellbook.spellbook.Spellbook
  VALUE_PARAMETER name:output index:1 type:kotlinx.serialization.encoding.CompositeEncoder
  VALUE_PARAMETER name:serialDesc index:2 type:kotlinx.serialization.descriptors.SerialDescriptor
  BLOCK_BODY
    CALL 'public abstract fun encodeSerializableElement <T> (descriptor: kotlinx.serialization.descriptors.SerialDescriptor, index: kotlin.Int, serializer: kotlinx.serialization.SerializationStrategy<T of kotlinx.serialization.encoding.CompositeEncoder.encodeSerializableElement>, value: T of kotlinx.serialization.encoding.CompositeEncoder.encodeSerializableElement): kotlin.Unit declared in kotlinx.serialization.encoding.CompositeEncoder' type=kotlin.Unit origin=null
      <T>: kotlin.collections.Map<kotlin.String, com.rnett.spellbook.spellbook.Spellcasting<*>>
      $this: GET_VAR 'output: kotlinx.serialization.encoding.CompositeEncoder declared in com.rnett.spellbook.spellbook.Spellbook.write$Self' type=kotlinx.serialization.encoding.CompositeEncoder origin=null
      descriptor: GET_VAR 'serialDesc: kotlinx.serialization.descriptors.SerialDescriptor declared in com.rnett.spellbook.spellbook.Spellbook.write$Self' type=kotlinx.serialization.descriptors.SerialDescriptor origin=null
      index: CONST Int type=kotlin.Int value=0
      serializer: CONSTRUCTOR_CALL 'public constructor <init> (kSerializer: kotlinx.serialization.KSerializer<K of kotlinx.serialization.internal.LinkedHashMapSerializer>, vSerializer: kotlinx.serialization.KSerializer<V of kotlinx.serialization.internal.LinkedHashMapSerializer>) [primary] declared in kotlinx.serialization.internal.LinkedHashMapSerializer' type=kotlinx.serialization.internal.LinkedHashMapSerializer<kotlin.String, com.rnett.spellbook.spellbook.Spellcasting<*>> origin=null
        <class: K>: kotlin.String
        <class: V>: com.rnett.spellbook.spellbook.Spellcasting<*>
        kSerializer: GET_FIELD 'FIELD FIELD_FOR_OBJECT_INSTANCE name:INSTANCE type:kotlinx.serialization.internal.StringSerializer visibility:public [final,static]' type=kotlinx.serialization.internal.StringSerializer origin=null
        vSerializer: CALL 'public final fun serializer <T0> (typeSerial0: kotlinx.serialization.KSerializer<T0 of com.rnett.spellbook.spellbook.Spellcasting.Companion.serializer>): kotlinx.serialization.KSerializer<com.rnett.spellbook.spellbook.Spellcasting<T0 of com.rnett.spellbook.spellbook.Spellcasting.Companion.serializer>> declared in com.rnett.spellbook.spellbook.Spellcasting.Companion' type=kotlinx.serialization.KSerializer<com.rnett.spellbook.spellbook.Spellcasting<T0 of com.rnett.spellbook.spellbook.Spellcasting.Companion.serializer>> origin=null
          <T0>: com.rnett.spellbook.spellbook.Spellcasting<*>
          $this: GET_FIELD 'FIELD FIELD_FOR_OBJECT_INSTANCE name:Companion type:com.rnett.spellbook.spellbook.Spellcasting.Companion visibility:public [final,static]' type=com.rnett.spellbook.spellbook.Spellcasting.Companion origin=null
      value: BLOCK type=kotlin.collections.Map<kotlin.String, com.rnett.spellbook.spellbook.Spellcasting<*>> origin=null
        GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:spellcastings type:kotlin.collections.Map<kotlin.String, com.rnett.spellbook.spellbook.Spellcasting<*>> visibility:private [final]' type=kotlin.collections.Map<kotlin.String, com.rnett.spellbook.spellbook.Spellcasting<*>> origin=null
          receiver: GET_VAR 'self: com.rnett.spellbook.spellbook.Spellbook declared in com.rnett.spellbook.spellbook.Spellbook.write$Self' type=com.rnett.spellbook.spellbook.Spellbook origin=null

	at org.jetbrains.kotlin.backend.jvm.codegen.FunctionCodegen.generate(FunctionCodegen.kt:50)
	at org.jetbrains.kotlin.backend.jvm.codegen.FunctionCodegen.generate$default(FunctionCodegen.kt:43)
	at org.jetbrains.kotlin.backend.jvm.codegen.ClassCodegen.generateMethodNode(ClassCodegen.kt:341)
	at org.jetbrains.kotlin.backend.jvm.codegen.ClassCodegen.generateMethod(ClassCodegen.kt:358)
	at org.jetbrains.kotlin.backend.jvm.codegen.ClassCodegen.generate(ClassCodegen.kt:130)
	at org.jetbrains.kotlin.backend.jvm.JvmLowerKt$codegenPhase$1$1.lower(JvmLower.kt:304)
	at org.jetbrains.kotlin.backend.common.phaser.FileLoweringPhaseAdapter.invoke(PhaseBuilders.kt:120)
	at org.jetbrains.kotlin.backend.common.phaser.FileLoweringPhaseAdapter.invoke(PhaseBuilders.kt:116)
	at org.jetbrains.kotlin.backend.common.phaser.NamedCompilerPhase.invoke(CompilerPhase.kt:96)
	at org.jetbrains.kotlin.backend.common.phaser.PerformByIrFilePhase.invokeSequential(performByIrFile.kt:65)
	... 46 more
Caused by: java.lang.IllegalArgumentException: Null argument in ExpressionCodegen for parameter VALUE_PARAMETER name:typeSerial0 index:0 type:kotlinx.serialization.KSerializer<T0 of com.rnett.spellbook.spellbook.Spellcasting.Companion.serializer>
	at org.jetbrains.kotlin.backend.jvm.codegen.ExpressionCodegen.visitCall(ExpressionCodegen.kt:478)
	at org.jetbrains.kotlin.backend.jvm.codegen.ExpressionCodegen.visitCall(ExpressionCodegen.kt:134)
	at org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl.accept(IrCallImpl.kt:47)
	at org.jetbrains.kotlin.backend.jvm.codegen.ExpressionCodegen.gen(ExpressionCodegen.kt:217)
	at org.jetbrains.kotlin.backend.jvm.codegen.ExpressionCodegen.generateConstructorArguments(ExpressionCodegen.kt:605)
	at org.jetbrains.kotlin.backend.jvm.codegen.ExpressionCodegen.visitConstructorCall(ExpressionCodegen.kt:593)
	at org.jetbrains.kotlin.backend.jvm.codegen.ExpressionCodegen.visitConstructorCall(ExpressionCodegen.kt:134)
	at org.jetbrains.kotlin.ir.expressions.impl.IrConstructorCallImpl.accept(IrConstructorCallImpl.kt:28)
	at org.jetbrains.kotlin.backend.jvm.codegen.ExpressionCodegen.gen(ExpressionCodegen.kt:217)
	at org.jetbrains.kotlin.backend.jvm.codegen.IrCallGenerator$DefaultImpls.genValueAndPut(IrCallGenerator.kt:47)
	at org.jetbrains.kotlin.backend.jvm.codegen.IrCallGenerator$DefaultCallGenerator.genValueAndPut(IrCallGenerator.kt:50)
	at org.jetbrains.kotlin.backend.jvm.codegen.ExpressionCodegen.visitCall(ExpressionCodegen.kt:479)
	at org.jetbrains.kotlin.backend.jvm.codegen.ExpressionCodegen.visitCall(ExpressionCodegen.kt:134)
	at org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl.accept(IrCallImpl.kt:47)
	at org.jetbrains.kotlin.backend.jvm.codegen.ExpressionCodegen.visitStatementContainer(ExpressionCodegen.kt:435)
	at org.jetbrains.kotlin.backend.jvm.codegen.ExpressionCodegen.visitBlockBody(ExpressionCodegen.kt:439)
	at org.jetbrains.kotlin.backend.jvm.codegen.ExpressionCodegen.visitBlockBody(ExpressionCodegen.kt:134)
	at org.jetbrains.kotlin.ir.expressions.IrBlockBody.accept(IrBody.kt:54)
	at org.jetbrains.kotlin.backend.jvm.codegen.ExpressionCodegen.generate(ExpressionCodegen.kt:235)
	at org.jetbrains.kotlin.backend.jvm.codegen.FunctionCodegen.doGenerate(FunctionCodegen.kt:122)
	at org.jetbrains.kotlin.backend.jvm.codegen.FunctionCodegen.generate(FunctionCodegen.kt:48)
	... 55 more

To Reproduce Run :common:compileKotlinJvm on the attached project.

Expected behavior The project compiles.

Environment

• Kotlin version: 1.5.30
• Library version: 1.2.2
• Kotlin platforms: JVM
• Gradle version: 7.2

[shanshin]

Hi! This error occurs when nested generics for sealed classes are used (Map<String, Spellcasting<*>> for your case).

As a work-round, you may remove the generic parameter from Spellcasting, but in this case the fields of this class will be of type SpellLevel and polymorphic serialization will work (the type field will be added to JSON).

Simple reproducer:

@Serializable
sealed class Generic<T> {
    abstract val value: T
}

class Child : Generic<Int>() {
    override val value: Int = 5
}

@Serializable
data class Holder(val list: List<Generic<Int>>)

[Whathecode]

Seemingly the repro I provided previously does work now, but something else in my actual codebase is failing. I will look for a new repro!