java.lang.AssertionError: Variable used before definition

[XomaDev]

Hello, thank you for TeaVM.

I'm trying to get my project compiled down to WASM after giving up on using JS. When I try to build, I get this error:

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':generateWasm'.
> org.teavm.tooling.builder.BuildException: java.lang.AssertionError: Variable used before definition: @key at $17

My project is primarily built with Kotlin. I was able to get some part of the codebase working while I was using JS. Other parts just crashed without any context. Now I get the above error.

My project is a little big, and its hard to debug or edit the codebase with such debug information. Any guidance will be appreciated.

[konsoletyper]

It's a bug inside compiler. Can you please provide stack trace, i.e. specify --stacktrace option to Gradle. Also, why did you give up with JS?

[XomaDev]

When I used JS, I kept getting into such issues:

(edit: there were many more errors, such as type errors especially) When I tried to debug type or JS constructor error, it crashes somewhere here:

        println("outline parse 0")

        while (!isEOF()) {
            println("outline parse lloping")
            val token = next()
            println("outline parse $token")
            val type = token.type;
            when (type) {
                Type.OPEN_CURLY -> curlyBracesCount++
                Type.CLOSE_CURLY -> {
                    if (curlyBracesCount == 0) break
                    else curlyBracesCount--
                }
                Type.FUN -> if (curlyBracesCount == 0) handleFn(false)
                Type.VISIBLE, Type.INVISIBLE -> {
                    if (curlyBracesCount == 0 && isNext(Type.FUN)) {
                        skip()
                        handleFn(type == Type.VISIBLE)
                    }
                }
                else -> {
                    println("else: $type")
                }
            }
        }
        println("outline parse 1")

It made me gave up on JS. Now I'm hoping for WASM someway.

Here is the output with --stacktrace:

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':generateWasm'.
> org.teavm.tooling.builder.BuildException: java.lang.AssertionError: Variable used before definition: @key at $17

* Try:
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.
> Get more help at https://help.gradle.org.

* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':generateWasm'.
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.lambda$executeIfValid$1(ExecuteActionsTaskExecuter.java:148)
    at org.gradle.internal.Try$Failure.ifSuccessfulOrElse(Try.java:282)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeIfValid(ExecuteActionsTaskExecuter.java:146)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:134)
    at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:46)
    at org.gradle.api.internal.tasks.execution.ResolveTaskExecutionModeExecuter.execute(ResolveTaskExecutionModeExecuter.java:51)
    at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:57)
    at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:74)
    at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:36)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:77)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:55)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:52)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:204)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:199)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:157)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:53)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:73)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:52)
    at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:42)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:331)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:318)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.lambda$execute$0(DefaultTaskExecutionGraph.java:314)
    at org.gradle.internal.operations.CurrentBuildOperationRef.with(CurrentBuildOperationRef.java:80)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:314)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:303)
    at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:463)
    at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:380)
    at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
    at org.gradle.internal.concurrent.AbstractManagedExecutor$1.run(AbstractManagedExecutor.java:47)
Caused by: org.gradle.internal.UncheckedException: org.teavm.tooling.builder.BuildException: java.lang.AssertionError: Variable used before definition: @key at $17
    at org.gradle.internal.UncheckedException.throwAsUncheckedException(UncheckedException.java:68)
    at org.gradle.internal.UncheckedException.throwAsUncheckedException(UncheckedException.java:41)
    at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:128)
    at org.gradle.api.internal.project.taskfactory.StandardTaskAction.doExecute(StandardTaskAction.java:58)
    at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:51)
    at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:29)
    at org.gradle.api.internal.tasks.execution.TaskExecution$3.run(TaskExecution.java:248)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$1.execute(DefaultBuildOperationRunner.java:29)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$1.execute(DefaultBuildOperationRunner.java:26)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:157)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.run(DefaultBuildOperationRunner.java:47)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:68)
    at org.gradle.api.internal.tasks.execution.TaskExecution.executeAction(TaskExecution.java:233)
    at org.gradle.api.internal.tasks.execution.TaskExecution.executeActions(TaskExecution.java:216)
    at org.gradle.api.internal.tasks.execution.TaskExecution.executeWithPreviousOutputFiles(TaskExecution.java:199)
    at org.gradle.api.internal.tasks.execution.TaskExecution.execute(TaskExecution.java:166)
    at org.gradle.internal.execution.steps.ExecuteStep.executeInternal(ExecuteStep.java:105)
    at org.gradle.internal.execution.steps.ExecuteStep.access$000(ExecuteStep.java:44)
    at org.gradle.internal.execution.steps.ExecuteStep$1.call(ExecuteStep.java:59)
    at org.gradle.internal.execution.steps.ExecuteStep$1.call(ExecuteStep.java:56)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:204)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:199)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:157)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:53)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:73)
    at org.gradle.internal.execution.steps.ExecuteStep.execute(ExecuteStep.java:56)
    at org.gradle.internal.execution.steps.ExecuteStep.execute(ExecuteStep.java:44)
    at org.gradle.internal.execution.steps.RemovePreviousOutputsStep.execute(RemovePreviousOutputsStep.java:67)
    at org.gradle.internal.execution.steps.RemovePreviousOutputsStep.execute(RemovePreviousOutputsStep.java:37)
    at org.gradle.internal.execution.steps.CancelExecutionStep.execute(CancelExecutionStep.java:41)
    at org.gradle.internal.execution.steps.TimeoutStep.executeWithoutTimeout(TimeoutStep.java:74)
    at org.gradle.internal.execution.steps.TimeoutStep.execute(TimeoutStep.java:55)
    at org.gradle.internal.execution.steps.CreateOutputsStep.execute(CreateOutputsStep.java:50)
    at org.gradle.internal.execution.steps.CreateOutputsStep.execute(CreateOutputsStep.java:28)
    at org.gradle.internal.execution.steps.CaptureStateAfterExecutionStep.executeDelegateBroadcastingChanges(CaptureStateAfterExecutionStep.java:100)
    at org.gradle.internal.execution.steps.CaptureStateAfterExecutionStep.execute(CaptureStateAfterExecutionStep.java:72)
    at org.gradle.internal.execution.steps.CaptureStateAfterExecutionStep.execute(CaptureStateAfterExecutionStep.java:50)
    at org.gradle.internal.execution.steps.ResolveInputChangesStep.execute(ResolveInputChangesStep.java:40)
    at org.gradle.internal.execution.steps.ResolveInputChangesStep.execute(ResolveInputChangesStep.java:29)
    at org.gradle.internal.execution.steps.BuildCacheStep.executeWithoutCache(BuildCacheStep.java:179)
    at org.gradle.internal.execution.steps.BuildCacheStep.lambda$execute$1(BuildCacheStep.java:70)
    at org.gradle.internal.Either$Right.fold(Either.java:175)
    at org.gradle.internal.execution.caching.CachingState.fold(CachingState.java:59)
    at org.gradle.internal.execution.steps.BuildCacheStep.execute(BuildCacheStep.java:68)
    at org.gradle.internal.execution.steps.BuildCacheStep.execute(BuildCacheStep.java:46)
    at org.gradle.internal.execution.steps.StoreExecutionStateStep.execute(StoreExecutionStateStep.java:36)
    at org.gradle.internal.execution.steps.StoreExecutionStateStep.execute(StoreExecutionStateStep.java:25)
    at org.gradle.internal.execution.steps.RecordOutputsStep.execute(RecordOutputsStep.java:36)
    at org.gradle.internal.execution.steps.RecordOutputsStep.execute(RecordOutputsStep.java:22)
    at org.gradle.internal.execution.steps.SkipUpToDateStep.executeBecause(SkipUpToDateStep.java:91)
    at org.gradle.internal.execution.steps.SkipUpToDateStep.lambda$execute$2(SkipUpToDateStep.java:55)
    at org.gradle.internal.execution.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:55)
    at org.gradle.internal.execution.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:37)
    at org.gradle.internal.execution.steps.ResolveChangesStep.execute(ResolveChangesStep.java:65)
    at org.gradle.internal.execution.steps.ResolveChangesStep.execute(ResolveChangesStep.java:36)
    at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsFinishedStep.execute(MarkSnapshottingInputsFinishedStep.java:37)
    at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsFinishedStep.execute(MarkSnapshottingInputsFinishedStep.java:27)
    at org.gradle.internal.execution.steps.ResolveCachingStateStep.execute(ResolveCachingStateStep.java:76)
    at org.gradle.internal.execution.steps.ResolveCachingStateStep.execute(ResolveCachingStateStep.java:37)
    at org.gradle.internal.execution.steps.ValidateStep.execute(ValidateStep.java:108)
    at org.gradle.internal.execution.steps.ValidateStep.execute(ValidateStep.java:55)
    at org.gradle.internal.execution.steps.CaptureStateBeforeExecutionStep.execute(CaptureStateBeforeExecutionStep.java:71)
    at org.gradle.internal.execution.steps.CaptureStateBeforeExecutionStep.execute(CaptureStateBeforeExecutionStep.java:45)
    at org.gradle.internal.execution.steps.SkipEmptyWorkStep.executeWithNonEmptySources(SkipEmptyWorkStep.java:177)
    at org.gradle.internal.execution.steps.SkipEmptyWorkStep.execute(SkipEmptyWorkStep.java:81)
    at org.gradle.internal.execution.steps.SkipEmptyWorkStep.execute(SkipEmptyWorkStep.java:53)
    at org.gradle.internal.execution.steps.RemoveUntrackedExecutionStateStep.execute(RemoveUntrackedExecutionStateStep.java:32)
    at org.gradle.internal.execution.steps.RemoveUntrackedExecutionStateStep.execute(RemoveUntrackedExecutionStateStep.java:21)
    at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsStartedStep.execute(MarkSnapshottingInputsStartedStep.java:38)
    at org.gradle.internal.execution.steps.LoadPreviousExecutionStateStep.execute(LoadPreviousExecutionStateStep.java:36)
    at org.gradle.internal.execution.steps.LoadPreviousExecutionStateStep.execute(LoadPreviousExecutionStateStep.java:23)
    at org.gradle.internal.execution.steps.CleanupStaleOutputsStep.execute(CleanupStaleOutputsStep.java:75)
    at org.gradle.internal.execution.steps.CleanupStaleOutputsStep.execute(CleanupStaleOutputsStep.java:41)
    at org.gradle.internal.execution.steps.ExecuteWorkBuildOperationFiringStep.lambda$execute$2(ExecuteWorkBuildOperationFiringStep.java:66)
    at org.gradle.internal.execution.steps.ExecuteWorkBuildOperationFiringStep.execute(ExecuteWorkBuildOperationFiringStep.java:66)
    at org.gradle.internal.execution.steps.ExecuteWorkBuildOperationFiringStep.execute(ExecuteWorkBuildOperationFiringStep.java:38)
    at org.gradle.internal.execution.steps.AssignWorkspaceStep.lambda$execute$0(AssignWorkspaceStep.java:32)
    at org.gradle.api.internal.tasks.execution.TaskExecution$4.withWorkspace(TaskExecution.java:293)
    at org.gradle.internal.execution.steps.AssignWorkspaceStep.execute(AssignWorkspaceStep.java:30)
    at org.gradle.internal.execution.steps.AssignWorkspaceStep.execute(AssignWorkspaceStep.java:21)
    at org.gradle.internal.execution.steps.IdentityCacheStep.execute(IdentityCacheStep.java:37)
    at org.gradle.internal.execution.steps.IdentityCacheStep.execute(IdentityCacheStep.java:27)
    at org.gradle.internal.execution.steps.IdentifyStep.execute(IdentifyStep.java:47)
    at org.gradle.internal.execution.steps.IdentifyStep.execute(IdentifyStep.java:34)
    at org.gradle.internal.execution.impl.DefaultExecutionEngine$1.execute(DefaultExecutionEngine.java:64)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeIfValid(ExecuteActionsTaskExecuter.java:145)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:134)
    at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:46)
    at org.gradle.api.internal.tasks.execution.ResolveTaskExecutionModeExecuter.execute(ResolveTaskExecutionModeExecuter.java:51)
    at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:57)
    at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:74)
    at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:36)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:77)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:55)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:52)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:204)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:199)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:157)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:53)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:73)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:52)
    at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:42)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:331)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:318)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.lambda$execute$0(DefaultTaskExecutionGraph.java:314)
    at org.gradle.internal.operations.CurrentBuildOperationRef.with(CurrentBuildOperationRef.java:80)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:314)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:303)
    at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:463)
    at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:380)
    at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
    at org.gradle.internal.concurrent.AbstractManagedExecutor$1.run(AbstractManagedExecutor.java:47)
Caused by: org.teavm.tooling.builder.BuildException: java.lang.AssertionError: Variable used before definition: @key at $17
    at org.teavm.tooling.builder.InProcessBuildStrategy.build(InProcessBuildStrategy.java:268)
    at org.teavm.gradle.tasks.TeaVMTask.executeWithBuilder(TeaVMTask.java:163)
    at org.teavm.gradle.tasks.TeaVMTask.execute(TeaVMTask.java:119)
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
    at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:125)
    ... 118 more
Caused by: java.lang.AssertionError: Variable used before definition: @key at $17
    at org.teavm.model.util.PhiUpdater.use(PhiUpdater.java:617)
    at org.teavm.model.util.PhiUpdater$1.visit(PhiUpdater.java:685)
    at org.teavm.model.instructions.BinaryBranchingInstruction.acceptVisitor(BinaryBranchingInstruction.java:71)
    at org.teavm.model.util.PhiUpdater.renameVariables(PhiUpdater.java:353)
    at org.teavm.model.util.PhiUpdater.updatePhis(PhiUpdater.java:175)
    at org.teavm.model.util.PhiUpdater.updatePhis(PhiUpdater.java:121)
    at org.teavm.backend.lowlevel.transform.CoroutineTransformation.apply(CoroutineTransformation.java:129)
    at org.teavm.backend.wasm.WasmTarget.afterOptimizations(WasmTarget.java:456)
    at org.teavm.vm.TeaVM.optimizeMethodCacheMiss(TeaVM.java:755)
    at org.teavm.vm.TeaVM.optimizeMethod(TeaVM.java:721)
    at org.teavm.vm.TeaVM.optimize(TeaVM.java:703)
    at org.teavm.vm.TeaVM.eagerPipeline(TeaVM.java:489)
    at org.teavm.vm.TeaVM.build(TeaVM.java:407)
    at org.teavm.tooling.TeaVMTool.generate(TeaVMTool.java:456)
    at org.teavm.tooling.builder.InProcessBuildStrategy.build(InProcessBuildStrategy.java:265)
    ... 122 more

BUILD FAILED in 1s

[konsoletyper]

I suggest you to try with JS again. From stacktrace it turns out that issue is somewhere in coroutine support, which is know to be very unstable in Wasm BE. To improve JS debugging experience you can enable source map generation and/or disable optimizations and obfuscation.

[XomaDev]

Thank you for your response, are these fine:

    js {
        sourceMap = true
        obfuscated = false
        addedToWebApp = true
    }

Does disabling obfuscate also disable optimizations, or is there a seperate flag for it?

[konsoletyper]

No, obfuscation does not disable optimizations

[xupwup]

I suggest you to try with JS again. From stacktrace it turns out that issue is somewhere in coroutine support, which is know to be very unstable in Wasm BE. To improve JS debugging experience you can enable source map generation and/or disable optimizations and obfuscation.

Is there a way to turn off coroutine support?

[konsoletyper]

@xupwup no, there's not. TeaVM automatically turns it on when it detects usage of threads in your code. If it was possible, TeaVM would just gracefully refuse to compile your code with list of all usages of threads.

[xupwup]

Ok, so coroutine support is turned off for me, right? Because the debugger says hasThreads is false. See screenshot

The code that's failing looks like this:

                    ByteBuffer buffer;
                    try {
                        buffer = ...;
                    } catch (IOException e) {
                        throw new UncheckedIOException(e);
                    }
                    while (buffer.position() < buffer.limit()) { // Variable used before definition error by teavm
                        consumer.accept(deserialise(buffer, consumer));
                    }

And changing it to the following code fixes it:

                    ByteBuffer buffer;
                    try {
                        buffer = ...;
                        while (buffer.position() < buffer.limit()) {
                            consumer.accept(deserialise(buffer, consumer));
                        }
                    } catch (IOException e) {
                        throw new UncheckedIOException(e);
                    }

But then it fails somewhere in HashMap.java as well. Is there anything I'm missing?

[konsoletyper]

@xupwup Coroutines are not necessarily turned on by threads. Another example is Thread.sleep or any other "synchronous" code which must be transformed into asynchronous under the hood. I have no idea what deserialize or implementation of consumer.accept do, but they can turn on coroutines.

[xupwup]

Oh, that's good to know. Looking at AsyncMethodFinder it seems that you consider methods with a monitor asynchronous, right?

[konsoletyper]

@xupwup I consider methods with monitor asynchronous only when threads turned on. And I consider any method as asynchronous if it's marked with @Async or calls an asynchronous method.

[xupwup]

That makes sense, thanks. I'll go investigate why I have 60 asynchronous methods, I was expecting 0.