Reflective structural call with array parameter crashes during pickling #11043

griggt · 2021-01-09T05:00:27Z

Minimized code

import scala.reflect.Selectable.reflectiveSelectable

object Test {
  type Runner = { def run(args: Array[String]): Unit }

  def test(args: Array[String], runner: Runner): Unit =
    runner.run(args)

  def main(args: Array[String]): Unit = {
    test(Array("foo", "bar"), new {
      def run(args: Array[String]): Unit = args foreach println
    })
  }
}

Output (click arrow to expand)

scala.MatchError: JavaArrayType(TypeRef(ThisType(TypeRef(NoPrefix,module class lang)),class String)) (of class dotty.tools.dotc.core.Types$CachedJavaArrayType) while compiling rs-test-1.scala
Exception in thread "main" scala.MatchError: JavaArrayType(TypeRef(ThisType(TypeRef(NoPrefix,module class lang)),class String)) (of class dotty.tools.dotc.core.Types$CachedJavaArrayType)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleNewType(TreePickler.scala:302)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleType(TreePickler.scala:171)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleConstant(TreePickler.scala:153)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:453)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$43$$anonfun$1(TreePickler.scala:518)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:333)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$17(TreePickler.scala:518)
	at dotty.tools.dotc.core.tasty.TreePickler.withLength(TreePickler.scala:69)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:518)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$6(TreePickler.scala:468)
	at dotty.tools.dotc.core.tasty.TreePickler.withLength(TreePickler.scala:69)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:468)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$38$$anonfun$1(TreePickler.scala:438)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:333)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$3(TreePickler.scala:438)
	at dotty.tools.dotc.core.tasty.TreePickler.withLength(TreePickler.scala:69)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:439)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$3(TreePickler.scala:437)
	at dotty.tools.dotc.core.tasty.TreePickler.withLength(TreePickler.scala:69)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:439)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:427)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$4(TreePickler.scala:444)
	at dotty.tools.dotc.core.tasty.TreePickler.withLength(TreePickler.scala:69)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:446)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTreeUnlessEmpty(TreePickler.scala:330)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleDef$$anonfun$1(TreePickler.scala:345)
	at dotty.tools.dotc.core.tasty.TreePickler.withLength(TreePickler.scala:69)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleDef(TreePickler.scala:347)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:562)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleStats$$anonfun$2(TreePickler.scala:371)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:333)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleStats(TreePickler.scala:371)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$26(TreePickler.scala:588)
	at dotty.tools.dotc.core.tasty.TreePickler.withLength(TreePickler.scala:69)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:589)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleDef$$anonfun$1(TreePickler.scala:342)
	at dotty.tools.dotc.core.tasty.TreePickler.withLength(TreePickler.scala:69)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleDef(TreePickler.scala:347)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:564)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleStats$$anonfun$2(TreePickler.scala:371)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:333)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleStats(TreePickler.scala:371)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$29(TreePickler.scala:604)
	at dotty.tools.dotc.core.tasty.TreePickler.withLength(TreePickler.scala:69)
	at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:604)
	at dotty.tools.dotc.core.tasty.TreePickler.pickle$$anonfun$1(TreePickler.scala:774)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:333)
	at dotty.tools.dotc.core.tasty.TreePickler.pickle(TreePickler.scala:774)
	at dotty.tools.dotc.transform.Pickler.run$$anonfun$3$$anonfun$2(Pickler.scala:69)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:333)
	at dotty.tools.dotc.transform.Pickler.run$$anonfun$1(Pickler.scala:106)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:333)
	at dotty.tools.dotc.transform.Pickler.run(Pickler.scala:106)
	at dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:296)
	at scala.collection.immutable.List.map(List.scala:246)
	at dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:297)
	at dotty.tools.dotc.transform.Pickler.runOn(Pickler.scala:111)
	at dotty.tools.dotc.Run.runPhases$4$$anonfun$4(Run.scala:185)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1323)
	at dotty.tools.dotc.Run.runPhases$5(Run.scala:195)
	at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:203)
	at scala.runtime.function.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
	at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:67)
	at dotty.tools.dotc.Run.compileUnits(Run.scala:210)
	at dotty.tools.dotc.Run.compileSources(Run.scala:146)
	at dotty.tools.dotc.Run.compile(Run.scala:130)
	at dotty.tools.dotc.Driver.doCompile(Driver.scala:39)
	at dotty.tools.dotc.Driver.process(Driver.scala:186)
	at dotty.tools.dotc.Driver.process(Driver.scala:155)
	at dotty.tools.dotc.Driver.process(Driver.scala:167)
	at dotty.tools.dotc.Driver.main(Driver.scala:194)
	at dotty.tools.dotc.Main.main(Main.scala)

Expectation

Successful compilation and when run prints:

foo
bar

Workaround

-   runner.run(args)
+   reflectiveSelectable(runner).applyDynamic("run", classOf[Array[String]])(args)

Notes

Works as expected in 3.0.0-M1 and 2.13.4. The regression appears to be caused by 574f741.

https://github.com/lampepfl/dotty/blob/574f74103397ed733b2ed30d88ada829ec2666af/compiler/src/dotty/tools/dotc/typer/Dynamic.scala#L221-L226

The text was updated successfully, but these errors were encountered:

nicolasstucki · 2021-04-15T12:06:49Z

Minimized to

import scala.reflect.Selectable.reflectiveSelectable

type Runner = { def run(args: Array[String]): Unit }

def test(runner: Runner): Unit = runner.run(???)

nicolasstucki · 2021-04-15T12:14:06Z

The issue is that now we generate a classOf[String[]] instead of classOf[Array[String]].

@sjrd, why did you use erased types in 574f741? Could we potentially use non erased types and let eraser take care of them?

sjrd · 2021-04-15T12:57:03Z

Because I didn't know how to, in particular what to do when you need to conjure up a concrete type valid as call site when your definition site as T where T >: A <: B with more or less arbitrary bounds?

smarter · 2021-04-15T15:26:24Z

What are you looking for exactly? If you need an applied class type which is a supertype of some arbitrary myType, then try myType.baseType(myType.classSymbol).

vmvazque · 2023-06-28T00:35:47Z

Is there any update on this issue? I'm seeing the same problem with the 3.3.0 compiler and just wondering if I should use the workaround or wait for a fix.

bishabosha · 2023-06-28T08:43:11Z

potential spree candidate? @mbovel

griggt added itype:bug itype:crash labels Jan 9, 2021

anatoliykmetyuk assigned nicolasstucki Jan 11, 2021

nicolasstucki assigned sjrd Apr 15, 2021

nicolasstucki assigned smarter and unassigned nicolasstucki Apr 15, 2021

griggt mentioned this issue Jul 22, 2021

Crash at pickling when summon ClassTag for union of nested arrays #13131

Closed

bishabosha added area:typer area:desugar Desugaring happens after parsing but before typing, see desugar.scala labels Jun 28, 2023

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Reflective structural call with array parameter crashes during pickling #11043

Reflective structural call with array parameter crashes during pickling #11043

griggt commented Jan 9, 2021

nicolasstucki commented Apr 15, 2021 •

edited

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nicolasstucki commented Apr 15, 2021

sjrd commented Apr 15, 2021

smarter commented Apr 15, 2021

vmvazque commented Jun 28, 2023

bishabosha commented Jun 28, 2023

Reflective structural call with array parameter crashes during pickling #11043

Reflective structural call with array parameter crashes during pickling #11043

Comments

griggt commented Jan 9, 2021

Minimized code

Output (click arrow to expand)

Expectation

Workaround

Notes

nicolasstucki commented Apr 15, 2021 • edited Loading

nicolasstucki commented Apr 15, 2021

sjrd commented Apr 15, 2021

smarter commented Apr 15, 2021

vmvazque commented Jun 28, 2023

bishabosha commented Jun 28, 2023

nicolasstucki commented Apr 15, 2021 •

edited

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