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Published 20 hours ago • verified publisher icon gradle

KT-25019 - Forward references at top level cause NPE with confusing stack trace

Open mkobit opened this issue 6 years ago • 7 comments

https://youtrack.jetbrains.com/issue/KT-25019

Expected Behavior

I'm not sure if this is a Kotlin scripting specific issue that should fail compilation, but I ran into this when working to debug a colleague's build script. My expectation would be failed compilation as it doesn't seem like you should be able to forward reference variables like the example shown below.

Current Behavior

A NullPointerException is thrown with a line number that is out of the bounds of the file size.

Context

Converting a Groovy build to Kotlin that was passing lots of things around at the top-level of the script. I was editing a 350 line build script that did not have any red in IDEA and compiled successfully, but failed at runtime here. I noticed the forward reference to the variable and noticed that switching the order of declaration made it safe at runtime.

Steps to Reproduce (for bugs)

Setup up Gradle 4.8 project with build.gradle.kts:

tasks {
  "wrapper"(Wrapper::class) {
    gradleVersion = "4.8"
  }
}

val first by tasks.creating {
  dependsOn(second)
}
val second by tasks.creating

Run ./gradlew -s and see stacktrace:

* Exception is:
java.lang.NullPointerException
	at Build_gradle.getSecond(build.gradle.kts:16)
	at Build_gradle$first$2.invoke(build.gradle.kts:8)
	at Build_gradle$first$2.invoke(build.gradle.kts:1)
	at org.gradle.kotlin.dsl.NamedDomainObjectContainerDelegateProvider.provideDelegate(NamedDomainObjectContainerExtensions.kt:128)
	at Build_gradle.<init>(build.gradle.kts:7)
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at org.gradle.kotlin.dsl.provider.KotlinScriptTarget.eval(KotlinScriptTarget.kt:161)
	at org.gradle.kotlin.dsl.provider.KotlinScriptCompiler.executeScriptBody(KotlinScriptCompiler.kt:149)
	at org.gradle.kotlin.dsl.provider.KotlinScriptCompiler.access$executeScriptBody(KotlinScriptCompiler.kt:69)
	at org.gradle.kotlin.dsl.provider.KotlinScriptCompiler$compile$1.invoke(KotlinScriptCompiler.kt:117)
	at org.gradle.kotlin.dsl.provider.KotlinScriptCompiler$compile$1.invoke(KotlinScriptCompiler.kt:69)
	at org.gradle.kotlin.dsl.provider.KotlinScriptPluginFactory$create$1.invoke(KotlinScriptPluginFactory.kt:55)
	at org.gradle.kotlin.dsl.provider.KotlinScriptPluginFactory$create$1.invoke(KotlinScriptPluginFactory.kt:32)
	at org.gradle.kotlin.dsl.provider.KotlinScriptPlugin.apply(KotlinScriptPlugin.kt:36)
	at org.gradle.configuration.BuildOperationScriptPlugin$1.run(BuildOperationScriptPlugin.java:61)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:317)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:309)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:185)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:97)
	at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
	at org.gradle.configuration.BuildOperationScriptPlugin.apply(BuildOperationScriptPlugin.java:58)
	at org.gradle.configuration.project.BuildScriptProcessor.execute(BuildScriptProcessor.java:41)
	at org.gradle.configuration.project.BuildScriptProcessor.execute(BuildScriptProcessor.java:26)
	at org.gradle.configuration.project.ConfigureActionsProjectEvaluator.evaluate(ConfigureActionsProjectEvaluator.java:34)
	at org.gradle.configuration.project.LifecycleProjectEvaluator.doConfigure(LifecycleProjectEvaluator.java:66)
	at org.gradle.configuration.project.LifecycleProjectEvaluator.access$100(LifecycleProjectEvaluator.java:37)
	at org.gradle.configuration.project.LifecycleProjectEvaluator$ConfigureProject.run(LifecycleProjectEvaluator.java:125)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:317)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:309)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:185)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:97)
	at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
	at org.gradle.configuration.project.LifecycleProjectEvaluator.evaluate(LifecycleProjectEvaluator.java:52)
	at org.gradle.api.internal.project.DefaultProject.evaluate(DefaultProject.java:677)
	at org.gradle.api.internal.project.DefaultProject.evaluate(DefaultProject.java:138)
	at org.gradle.execution.TaskPathProjectEvaluator.configure(TaskPathProjectEvaluator.java:35)
	at org.gradle.execution.TaskPathProjectEvaluator.configureHierarchy(TaskPathProjectEvaluator.java:60)
	at org.gradle.configuration.DefaultBuildConfigurer.configure(DefaultBuildConfigurer.java:41)
	at org.gradle.initialization.DefaultGradleLauncher$ConfigureBuild.run(DefaultGradleLauncher.java:262)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:317)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:309)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:185)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:97)
	at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
	at org.gradle.initialization.DefaultGradleLauncher.configureBuild(DefaultGradleLauncher.java:175)
	at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:132)
	at org.gradle.initialization.DefaultGradleLauncher.executeTasks(DefaultGradleLauncher.java:115)
	at org.gradle.internal.invocation.GradleBuildController$1.call(GradleBuildController.java:77)
	at org.gradle.internal.invocation.GradleBuildController$1.call(GradleBuildController.java:74)
	at org.gradle.internal.work.DefaultWorkerLeaseService.withLocks(DefaultWorkerLeaseService.java:152)
	at org.gradle.internal.work.StopShieldingWorkerLeaseService.withLocks(StopShieldingWorkerLeaseService.java:38)
	at org.gradle.internal.invocation.GradleBuildController.doBuild(GradleBuildController.java:96)
	at org.gradle.internal.invocation.GradleBuildController.run(GradleBuildController.java:74)
	at org.gradle.tooling.internal.provider.ExecuteBuildActionRunner.run(ExecuteBuildActionRunner.java:28)
	at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35)
	at org.gradle.tooling.internal.provider.ValidatingBuildActionRunner.run(ValidatingBuildActionRunner.java:32)
	at org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner$3.run(RunAsBuildOperationBuildActionRunner.java:47)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:317)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:309)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:185)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:97)
	at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
	at org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner.run(RunAsBuildOperationBuildActionRunner.java:43)
	at org.gradle.tooling.internal.provider.SubscribableBuildActionRunner.run(SubscribableBuildActionRunner.java:51)
	at org.gradle.launcher.exec.InProcessBuildActionExecuter$1.transform(InProcessBuildActionExecuter.java:50)
	at org.gradle.launcher.exec.InProcessBuildActionExecuter$1.transform(InProcessBuildActionExecuter.java:46)
	at org.gradle.composite.internal.DefaultRootBuildState.run(DefaultRootBuildState.java:65)
	at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:46)
	at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:32)
	at org.gradle.launcher.exec.BuildTreeScopeBuildActionExecuter.execute(BuildTreeScopeBuildActionExecuter.java:39)
	at org.gradle.launcher.exec.BuildTreeScopeBuildActionExecuter.execute(BuildTreeScopeBuildActionExecuter.java:25)
	at org.gradle.tooling.internal.provider.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:80)
	at org.gradle.tooling.internal.provider.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:53)
	at org.gradle.tooling.internal.provider.ServicesSetupBuildActionExecuter.execute(ServicesSetupBuildActionExecuter.java:62)
	at org.gradle.tooling.internal.provider.ServicesSetupBuildActionExecuter.execute(ServicesSetupBuildActionExecuter.java:34)
	at org.gradle.tooling.internal.provider.GradleThreadBuildActionExecuter.execute(GradleThreadBuildActionExecuter.java:36)
	at org.gradle.tooling.internal.provider.GradleThreadBuildActionExecuter.execute(GradleThreadBuildActionExecuter.java:25)
	at org.gradle.tooling.internal.provider.ParallelismConfigurationBuildActionExecuter.execute(ParallelismConfigurationBuildActionExecuter.java:43)
	at org.gradle.tooling.internal.provider.ParallelismConfigurationBuildActionExecuter.execute(ParallelismConfigurationBuildActionExecuter.java:29)
	at org.gradle.tooling.internal.provider.StartParamsValidatingActionExecuter.execute(StartParamsValidatingActionExecuter.java:59)
	at org.gradle.tooling.internal.provider.StartParamsValidatingActionExecuter.execute(StartParamsValidatingActionExecuter.java:31)
	at org.gradle.tooling.internal.provider.SessionFailureReportingActionExecuter.execute(SessionFailureReportingActionExecuter.java:59)
	at org.gradle.tooling.internal.provider.SessionFailureReportingActionExecuter.execute(SessionFailureReportingActionExecuter.java:44)
	at org.gradle.tooling.internal.provider.SetupLoggingActionExecuter.execute(SetupLoggingActionExecuter.java:46)
	at org.gradle.tooling.internal.provider.SetupLoggingActionExecuter.execute(SetupLoggingActionExecuter.java:30)
	at org.gradle.launcher.daemon.server.exec.ExecuteBuild.doBuild(ExecuteBuild.java:67)
	at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
	at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
	at org.gradle.launcher.daemon.server.exec.WatchForDisconnection.execute(WatchForDisconnection.java:37)
	at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
	at org.gradle.launcher.daemon.server.exec.ResetDeprecationLogger.execute(ResetDeprecationLogger.java:26)
	at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
	at org.gradle.launcher.daemon.server.exec.RequestStopIfSingleUsedDaemon.execute(RequestStopIfSingleUsedDaemon.java:34)
	at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
	at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:74)
	at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:72)
	at org.gradle.util.Swapper.swap(Swapper.java:38)
	at org.gradle.launcher.daemon.server.exec.ForwardClientInput.execute(ForwardClientInput.java:72)
	at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
	at org.gradle.launcher.daemon.server.exec.LogAndCheckHealth.execute(LogAndCheckHealth.java:55)
	at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
	at org.gradle.launcher.daemon.server.exec.LogToClient.doBuild(LogToClient.java:62)
	at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
	at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
	at org.gradle.launcher.daemon.server.exec.EstablishBuildEnvironment.doBuild(EstablishBuildEnvironment.java:82)
	at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
	at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122)
	at org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy$1.run(StartBuildOrRespondWithBusy.java:50)
	at org.gradle.launcher.daemon.server.DaemonStateCoordinator$1.run(DaemonStateCoordinator.java:295)
	at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
	at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
	at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)


* Get more help at https://help.gradle.org

BUILD FAILED in 0s

Your Environment

  • Gradle 4.8
  • Build scan URL: https://scans.gradle.com/s/s4h3vsedutnxs
  • Fails on Java 8 as well

mkobit avatar Jun 14 '18 15:06 mkobit

Hmm.. I don't know if that is obvious 🤔 In "pure Kotlin" you can't write

val x = y
val y = "String"

And I is maybe the same issue here. I tested it and if you define second first then it works.

Because of that I wouldn't say that this is an "issue". It is just an Kotlin syntax error...

StefMa avatar Jun 15 '18 07:06 StefMa

@StefMa getting a compiler error is my expectation due to an unresolved reference, but the failure now happens at runtime with a NullPointerException.

Similar to your example in "pure Kotlin":

fun hello() {
    val m: Map<String, Map<String, String>> = emptyMap()
    val f by k
    val k by m
}

Fails to compile (which is what I would expect). I have a feeling this is a bug or difference in Kotlin script compilation.

mkobit avatar Jun 15 '18 14:06 mkobit

@ligee You want to take a look at this one?

JLLeitschuh avatar Jun 15 '18 15:06 JLLeitschuh

Thanks for reporting, I'll have a look.

ligee avatar Jun 15 '18 18:06 ligee

@mkobit could you please open an issue on JetBrains Youtrack so @ligee can track it?

eskatos avatar Jun 20 '18 14:06 eskatos

https://youtrack.jetbrains.com/issue/KT-25019

mkobit avatar Jun 20 '18 14:06 mkobit

In a similar fashion, with Gradle 4.10 the following block compiles fine in a build.gradle.kts

val help: Task by tasks.getting
val help: TaskProvider<Task> by tasks.existing
val help: Help by tasks.getting(Help::class)

mkobit avatar Sep 07 '18 22:09 mkobit