KSP Processing order doesn't process room class first before typealias

[cp-yfukuda]

With room being KSP dependent, if I have this code,

pacakge com.mypackage

@Entity(tableName = "my_data_table")
data class MyData(
}

And in other file in the same package, But different fille

pacakge com.mypackage

import com.mypackage.DataProvider

data class Identifier<T> private constructor(private val uuid: UUID) {
}

...

typealias DataProviderIdentifier = Identifier<MyData>

This compiration with ksp with room gives me

`
[ksp] java.lang.IllegalStateException: Unexpected type name for KSType: com.mypackage.Identifier<com.mypackage.DataProvider>

`

This makes me think that alias processing happenes before ksp is processing room annotation.

[ting-yuan]

Can you share the stacktrace and/or a sample project that we can reproduce it?

[cp-yfukuda]

Hi Ting-Yuan

I made a simple version of the app, with typealias using Room data, but
it works.
https://drive.google.com/file/d/1Dbp217h-I9_M25BYNng5slfR9V2Y7SI3/view?usp=sharing
But here is actual stacktrace.

[ksp] java.lang.IllegalStateException: Unexpected type name for KSType: org.test.Identifier< com.mypackage.DataProvider>
	at androidx.room.compiler.processing.ksp.KSTypeExtKt.typeName(KSTypeExt.kt:214)
	at androidx.room.compiler.processing.ksp.KSTypeExtKt.typeName(KSTypeExt.kt:71)
	at androidx.room.compiler.processing.ksp.KSTypeExtKt.typeName$resolveTypeName(KSTypeExt.kt:153)
	at androidx.room.compiler.processing.ksp.KSTypeExtKt.typeName(KSTypeExt.kt:171)
	at androidx.room.compiler.processing.ksp.KSTypeExtKt.typeName(KSTypeExt.kt:193)
	at androidx.room.compiler.processing.ksp.KSTypeExtKt.typeName(KSTypeExt.kt:181)
	at androidx.room.compiler.processing.ksp.DefaultKspType.resolveTypeName(DefaultKspType.kt:32)
	at androidx.room.compiler.processing.ksp.KspType$typeName$2.invoke(KspType.kt:54)
	at androidx.room.compiler.processing.ksp.KspType$typeName$2.invoke(KspType.kt:51)
	at kotlin.SynchronizedLazyImpl.getValue(LazyJVM.kt:74)
	at androidx.room.compiler.processing.ksp.KspType.getTypeName(KspType.kt:51)
	at androidx.room.processor.FieldProcessor.process(FieldProcessor.kt:39)
	at androidx.room.processor.PojoProcessor.doProcess(PojoProcessor.kt:173)
	at androidx.room.processor.PojoProcessor.access$doProcess(PojoProcessor.kt:56)
	at androidx.room.processor.PojoProcessor$process$1.invoke(PojoProcessor.kt:112)
	at androidx.room.processor.PojoProcessor$process$1.invoke(PojoProcessor.kt:109)
	at androidx.room.processor.cache.Cache$Bucket.get(Cache.kt:53)
	at androidx.room.processor.PojoProcessor.process(PojoProcessor.kt:109)
	at androidx.room.processor.TableEntityProcessor.doProcess(TableEntityProcessor.kt:93)
	at androidx.room.processor.TableEntityProcessor.access$doProcess(TableEntityProcessor.kt:44)
	at androidx.room.processor.TableEntityProcessor$process$1.invoke(TableEntityProcessor.kt:53)
	at androidx.room.processor.TableEntityProcessor$process$1.invoke(TableEntityProcessor.kt:52)
	at androidx.room.processor.cache.Cache$Bucket.get(Cache.kt:53)
	at androidx.room.processor.TableEntityProcessor.process(TableEntityProcessor.kt:52)
	at androidx.room.processor.DatabaseProcessor.processEntities(DatabaseProcessor.kt:443)
	at androidx.room.processor.DatabaseProcessor.doProcess(DatabaseProcessor.kt:69)
	at androidx.room.processor.DatabaseProcessor.process(DatabaseProcessor.kt:60)
	at androidx.room.DatabaseProcessingStep$process$databases$1$1.invoke(DatabaseProcessingStep.kt:74)
	at androidx.room.DatabaseProcessingStep$process$databases$1$1.invoke(DatabaseProcessingStep.kt:70)
	at androidx.room.processor.Context.collectLogs(Context.kt:149)
	at androidx.room.DatabaseProcessingStep.process(DatabaseProcessingStep.kt:70)
	at androidx.room.DatabaseProcessingStep.process(DatabaseProcessingStep.kt:41)
	at androidx.room.compiler.processing.CommonProcessorDelegate.processRound(XBasicAnnotationProcessor.kt:114)
	at androidx.room.compiler.processing.ksp.KspBasicAnnotationProcessor.process(KspBasicAnnotationProcessor.kt:61)
	at com.google.devtools.ksp.AbstractKotlinSymbolProcessingExtension$doAnalysis$4$1.invoke(KotlinSymbolProcessingExtension.kt:223)
	at com.google.devtools.ksp.AbstractKotlinSymbolProcessingExtension$doAnalysis$4$1.invoke(KotlinSymbolProcessingExtension.kt:221)
	at com.google.devtools.ksp.AbstractKotlinSymbolProcessingExtension.handleException(KotlinSymbolProcessingExtension.kt:316)
	at com.google.devtools.ksp.AbstractKotlinSymbolProcessingExtension.doAnalysis(KotlinSymbolProcessingExtension.kt:221)
	at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration(TopDownAnalyzerFacadeForJVM.kt:120)
	at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration$default(TopDownAnalyzerFacadeForJVM.kt:96)
	at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$analyze$1.invoke(KotlinToJVMBytecodeCompiler.kt:262)
	at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$analyze$1.invoke(KotlinToJVMBytecodeCompiler.kt:53)
	at org.jetbrains.kotlin.cli.common.messages.AnalyzerWithCompilerReport.analyzeAndReport(AnalyzerWithCompilerReport.kt:113)
	at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.analyze(KotlinToJVMBytecodeCompiler.kt:253)
	at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules$cli(KotlinToJVMBytecodeCompiler.kt:100)
	at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules$cli$default(KotlinToJVMBytecodeCompiler.kt:58)
	at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:170)
	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.daemon.CompileServiceImpl.compile(CompileServiceImpl.kt:1618)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	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$1.run(Transport.java:197)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.rmi/sun.rmi.transport.Transport.serviceCall(Transport.java:196)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:562)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:796)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:677)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:676)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:834)`

[cp-yfukuda]

Hi Ting-Yuan

Could you please check newer build here

In Test.kt, Adding foreign key

@ColumnInfo(name = "related_ids") val relatedId: List<TestIdentifier>

Seems to produce same error.

[cp-yfukuda]

Any advice? last link contains simple app that can reproduce the error. Please let me know if I can be any helpful.

[ting-yuan]

I don't know why Room only expects ClassName and ArrayTypeName, while TypeName can also be ParameterizedTypeName, TypeVariableName and WildcardTypeName. From the given exception, it looks like that the type passed is indeed a parameterized type. What if Identifier<Test> is used instead of TestIdentifier? Will the issue be gone or still there?

It looks like to me that type type alias is correctly "un-aliased". Can you file a bug with Room and see what they say?

[cp-yfukuda]

Thanks for your insight. Will do. Could you please suggest me the correct room repo? I accidentally created to the wrong repo.

[yigit]

So the reason this is happening is that, when we observe TestIdentifier, it returns a single TypeArgument (Test) but that kind of makes it look like TestIdentifier<Test> (instead of Identifier).
We can work around this in Room but this rather seems like a KSP bug where it shouldn't give any type arguments for the TypeAlias (until it is resolved to the original type).

[ting-yuan]

Thanks for the explanation. Will fix in KSP.

[yigit]

Btw, playing a bit more with it, this might also have some interesting equality considerations.
a0d21fb

If I change the test there to use List<Long> instead of String, it starts failing the equality assertion.
I've not yet dig deeper yet to understand why. But if we support equality between type aliases, we would also need to make sure their hashcodes are the same, which might complicate the matters, unless the KotlinType.hashCode for aliases are guaranteed to be the same.

[yigit]

repro:
https://github.com/google/ksp/compare/main...yigit:kstypealias-arguments?expand=1

I changed the test a little bit to print type arguments in the signature as well and also group by final signature for equality checks.

Good news, equality checks seems to be working, bad news; it is printing the extra type arguments.
Line 7-11 from the output:

ListOfInt<Int> = List<Int>
ListOfInt<Int> = List<Int>
ListOfInt_B<Int> = ListOfInt<Int> = List<Int>
ListOfInt_B<Int> = ListOfInt<Int> = List<Int>
ListOfInt_C<Int> = ListOfInt_B<Int> = ListOfInt<Int> = List<Int>

Where ListOfInt<Int> = List<Int> should've been ListOfInt = List<Int> because it is declared as:

typealias ListOfInt = List<Int>

[cp-yfukuda]

I change the code to
id 'com.google.devtools.ksp' version "1.6.20-1.0.4"
But it still gives me same error.

[ting-yuan]

The fix will be available in 1.6.20-1.0.5 soon.

[cp-yfukuda]

Got it. Thank you!