Stackoverflow in Macrocode interacts with Pickler

[b-studios]

When a stackoverflow occurs in macro code, and we use tasty.error in an exception handler, then the compiler crashes instead of giving a useful error message.

Expected behavior: Instead of crashing, the call to error should report the provided error message.

Version: Dotty 0.27-RC1

Minimized code

def f() = ()
  
  def triggerStackOverflow(n: Int): Expr[Double] = {
    val r = triggerStackOverflow(n - 1)
    f()
    r
  }

  inline def loop(inline prog: Double): Double = ${impl('prog)}

  def impl(prog: Expr[Double])(using QuoteContext) : Expr[Double] =
    try {
      triggerStackOverflow(0)
    } catch {
      case e =>
        qctx.tasty.error(e.getMessage, prog.unseal.pos)
        '{ 42.0 }
    }

and the callsite:

// called using macros
loop { 4 }

// called using staging
run {
  impl('{ 4 })
}

Output of the Macrocall (click arrow to expand)

[error] scala.MatchError: EmptyTree (of class dotty.tools.dotc.ast.Trees$EmptyTree)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:621)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$6(TreePickler.scala:440)
[error] 	at dotty.runtime.function.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.withLength(TreePickler.scala:49)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:440)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$19(TreePickler.scala:495)
[error] 	at dotty.runtime.function.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.withLength(TreePickler.scala:49)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:501)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleStats$$anonfun$2(TreePickler.scala:344)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] 	at scala.collection.immutable.List.foreach(List.scala:333)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleStats(TreePickler.scala:344)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$26(TreePickler.scala:560)
[error] 	at dotty.runtime.function.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.withLength(TreePickler.scala:49)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:561)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleDef$$anonfun$2(TreePickler.scala:320)
[error] 	at dotty.runtime.function.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.withLength(TreePickler.scala:49)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleDef(TreePickler.scala:325)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:536)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleStats$$anonfun$2(TreePickler.scala:344)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] 	at scala.collection.immutable.List.foreach(List.scala:333)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleStats(TreePickler.scala:344)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$28(TreePickler.scala:570)
[error] 	at dotty.runtime.function.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.withLength(TreePickler.scala:49)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:570)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickle$$anonfun$1(TreePickler.scala:736)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] 	at scala.collection.immutable.List.foreach(List.scala:333)
[error] 	at dotty.tools.dotc.core.tasty.TreePickler.pickle(TreePickler.scala:736)
[error] 	at dotty.tools.dotc.transform.Pickler.run$$anonfun$3$$anonfun$2(Pickler.scala:64)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] 	at scala.collection.immutable.List.foreach(List.scala:333)
[error] 	at dotty.tools.dotc.transform.Pickler.run$$anonfun$1(Pickler.scala:101)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] 	at scala.collection.immutable.List.foreach(List.scala:333)
[error] 	at dotty.tools.dotc.transform.Pickler.run(Pickler.scala:101)
[error] 	at dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:296)
[error] 	at scala.collection.immutable.List.map(List.scala:246)
[error] 	at dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:297)
[error] 	at dotty.tools.dotc.transform.Pickler.runOn(Pickler.scala:105)
[error] 	at dotty.tools.dotc.Run.runPhases$4$$anonfun$4(Run.scala:180)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] 	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] 	at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1323)
[error] 	at dotty.tools.dotc.Run.runPhases$5(Run.scala:190)
[error] 	at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:198)
[error] 	at dotty.runtime.function.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
[error] 	at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:64)
[error] 	at dotty.tools.dotc.Run.compileUnits(Run.scala:205)
[error] 	at dotty.tools.dotc.Run.compileSources(Run.scala:142)
[error] 	at dotty.tools.dotc.Run.compile(Run.scala:124)
[error] 	at dotty.tools.dotc.Driver.doCompile(Driver.scala:38)
[error] 	at dotty.tools.dotc.Driver.process(Driver.scala:195)
[error] 	at dotty.tools.dotc.Main.process(Main.scala)
[error] 	at xsbt.CachedCompilerImpl.run(CachedCompilerImpl.java:69)
[error] 	at xsbt.CompilerInterface.run(CompilerInterface.java:41)
[error] 	at jdk.internal.reflect.GeneratedMethodAccessor10.invoke(Unknown Source)
[error] 	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[error] 	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
[error] 	at sbt.internal.inc.AnalyzingCompiler.call(AnalyzingCompiler.scala:237)
[error] 	at sbt.internal.inc.AnalyzingCompiler.compile(AnalyzingCompiler.scala:111)
[error] 	at sbt.internal.inc.AnalyzingCompiler.compile(AnalyzingCompiler.scala:90)
[error] 	at sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$3(MixedAnalyzingCompiler.scala:82)
[error] 	at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
[error] 	at sbt.internal.inc.MixedAnalyzingCompiler.timed(MixedAnalyzingCompiler.scala:133)
[error] 	at sbt.internal.inc.MixedAnalyzingCompiler.compileScala$1(MixedAnalyzingCompiler.scala:73)
[error] 	at sbt.internal.inc.MixedAnalyzingCompiler.compile(MixedAnalyzingCompiler.scala:116)
[error] 	at sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileInternal$1(IncrementalCompilerImpl.scala:307)
[error] 	at sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileInternal$1$adapted(IncrementalCompilerImpl.scala:307)
[error] 	at sbt.internal.inc.Incremental$.doCompile(Incremental.scala:106)
[error] 	at sbt.internal.inc.Incremental$.$anonfun$compile$4(Incremental.scala:87)
[error] 	at sbt.internal.inc.IncrementalCommon.recompileClasses(IncrementalCommon.scala:116)
[error] 	at sbt.internal.inc.IncrementalCommon.cycle(IncrementalCommon.scala:63)
[error] 	at sbt.internal.inc.Incremental$.$anonfun$compile$3(Incremental.scala:89)
[error] 	at sbt.internal.inc.Incremental$.manageClassfiles(Incremental.scala:134)
[error] 	at sbt.internal.inc.Incremental$.compile(Incremental.scala:80)
[error] 	at sbt.internal.inc.IncrementalCompile$.apply(Compile.scala:67)
[error] 	at sbt.internal.inc.IncrementalCompilerImpl.compileInternal(IncrementalCompilerImpl.scala:311)
[error] 	at sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileIncrementally$1(IncrementalCompilerImpl.scala:269)
[error] 	at sbt.internal.inc.IncrementalCompilerImpl.handleCompilationError(IncrementalCompilerImpl.scala:159)
[error] 	at sbt.internal.inc.IncrementalCompilerImpl.compileIncrementally(IncrementalCompilerImpl.scala:238)
[error] 	at sbt.internal.inc.IncrementalCompilerImpl.compile(IncrementalCompilerImpl.scala:69)
[error] 	at sbt.Defaults$.compileIncrementalTaskImpl(Defaults.scala:1549)
[error] 	at sbt.Defaults$.$anonfun$compileIncrementalTask$1(Defaults.scala:1523)
[error] 	at scala.Function1.$anonfun$compose$1(Function1.scala:44)
[error] 	at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:40)
[error] 	at sbt.std.Transform$$anon$4.work(System.scala:67)
[error] 	at sbt.Execute.$anonfun$submit$2(Execute.scala:269)
[error] 	at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:16)
[error] 	at sbt.Execute.work(Execute.scala:278)
[error] 	at sbt.Execute.$anonfun$submit$1(Execute.scala:269)
[error] 	at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178)
[error] 	at sbt.CompletionService$$anon$2.call(CompletionService.scala:37)
[error] 	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
[error] 	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
[error] 	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
[error] 	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
[error] 	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
[error] 	at java.base/java.lang.Thread.run(Thread.java:834)

Output of the Staging Call (click arrow to expand)

Exception: java.lang.NullPointerException thrown from the UncaughtExceptionHandler in thread "run-main-1d"