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Compiler crash when a `given` instance of a trait with inline defs is not inline

See original GitHub issue

Compiler version

3.0.0

Minimized code


trait Noop[T]:
  inline def noop(fa: T): T

final case class User(name: String, age: Int)

given Noop[User] = a => a

Output (click arrow to expand)

sbt:scala3-live> compile
[info] compiling 1 Scala source to /Users/jkoslowski/dev/scala3-live/target/scala-3.0.0/classes ...
exception while typing closure($anonfun:com.example.Noop[com.example.User]) of class class dotty.tools.dotc.ast.Trees$Closure # -1
exception while typing {
  def $anonfun(a: com.example.User): com.example.User = a
  closure($anonfun:com.example.Noop[com.example.User])
} of class class dotty.tools.dotc.ast.Trees$Block # -1
exception while typing final lazy given def given_Noop_User: com.example.Noop[com.example.User] = 
  {
    def $anonfun(a: com.example.User): com.example.User = a
    closure($anonfun:com.example.Noop[com.example.User])
  } of class class dotty.tools.dotc.ast.Trees$DefDef # -1
exception while typing @scala.annotation.internal.SourceFile(
  "src/main/scala/com/example/Examples.scala"
) final module class Examples$package$() extends Object() {
  private def writeReplace(): AnyRef = 
    new scala.runtime.ModuleSerializationProxy(
      classOf[com.example.Examples$package.type]
    )
  final lazy given def given_Noop_User: com.example.Noop[com.example.User] = 
    {
      def $anonfun(a: com.example.User): com.example.User = a
      closure($anonfun:com.example.Noop[com.example.User])
    }
} of class class dotty.tools.dotc.ast.Trees$TypeDef # -1
exception while typing package com.example {
  @scala.annotation.internal.SourceFile(
    "src/main/scala/com/example/Examples.scala"
  ) trait Noop[T]() extends Object {
    private type T
    private inline def noop(fa: T): T
  }
  @scala.annotation.internal.SourceFile(
    "src/main/scala/com/example/Examples.scala"
  ) final case class User(name: String, age: Int) extends Object(), Product, 
    Serializable
   {
    override def hashCode(): Int = 
      {
        var acc: Int = -889275714
        acc = scala.runtime.Statics$#mix(acc, this.productPrefix.hashCode())
        acc = 
          scala.runtime.Statics$#mix(acc, 
            scala.runtime.Statics$#anyHash(User.this.name)
          )
        acc = scala.runtime.Statics$#mix(acc, User.this.age)
        scala.runtime.Statics$#finalizeHash(acc, 2)
      }
    override def equals(x$0: Any): Boolean = 
      this.eq(x$0.$asInstanceOf$[Object]).||(
        matchResult1[Boolean]: 
          {
            case val x1: (x$0 : Object) = x$0
            if x1.$isInstanceOf$[com.example.User @unchecked] then 
              {
                case val x$0: com.example.User = 
                  x1.$asInstanceOf$[com.example.User @unchecked]
                return[matchResult1] 
                  this.age.==(x$0.age).&&(this.name.==(x$0.name))
              }
             else ()
            return[matchResult1] false
          }
      )
    override def toString(): String = scala.runtime.ScalaRunTime._toString(this)
    override def canEqual(that: Any): Boolean = 
      that.isInstanceOf[com.example.User @unchecked]
    override def productArity: Int = 2
    override def productPrefix: String = "User"
    override def productElement(n: Int): Any = 
      matchResult2[Object]: 
        {
          case val x3: (n : Int) = n
          if 0.==(x3) then return[matchResult2] this._1 else ()
          if 1.==(x3) then return[matchResult2] this._2 else ()
          throw new IndexOutOfBoundsException(n.toString())
        }
    override def productElementName(n: Int): String = 
      matchResult3[String]: 
        {
          case val x4: (n : Int) = n
          if 0.==(x4) then return[matchResult3] "name" else ()
          if 1.==(x4) then return[matchResult3] "age" else ()
          throw new IndexOutOfBoundsException(n.toString())
        }
    def name: String
    def age: Int
    def copy(name: String, age: Int): com.example.User = 
      new com.example.User(name, age)
    def copy$default$1: String @uncheckedVariance = User.this.name
    def copy$default$2: Int @uncheckedVariance = User.this.age
    def _1: String = this.name
    def _2: Int = this.age
  }
  final lazy module val User: com.example.User$ = new com.example.User$()
  @scala.annotation.internal.SourceFile(
    "src/main/scala/com/example/Examples.scala"
  ) final module class User$() extends AnyRef(), scala.deriving.Mirror.Product {
    private def writeReplace(): AnyRef = 
      new scala.runtime.ModuleSerializationProxy(classOf[com.example.User.type])
    def apply(name: String, age: Int): com.example.User = 
      new com.example.User(name, age)
    def unapply(x$1: com.example.User): com.example.User = x$1
    override def toString: String = "User"
    type MirroredMonoType = com.example.User
    def fromProduct(x$0: Product): com.example.User.MirroredMonoType = 
      new com.example.User(x$0.productElement(0).$asInstanceOf$[String], 
        x$0.productElement(1).$asInstanceOf$[Int]
      )
  }
  final lazy module val Examples$package: com.example.Examples$package$ = 
    new com.example.Examples$package$()
  @scala.annotation.internal.SourceFile(
    "src/main/scala/com/example/Examples.scala"
  ) final module class Examples$package$() extends Object() {
    private def writeReplace(): AnyRef = 
      new scala.runtime.ModuleSerializationProxy(
        classOf[com.example.Examples$package.type]
      )
    final lazy given def given_Noop_User: com.example.Noop[com.example.User] = 
      {
        def $anonfun(a: com.example.User): com.example.User = a
        closure($anonfun:com.example.Noop[com.example.User])
      }
  }
} of class class dotty.tools.dotc.ast.Trees$PackageDef # -1
[info] exception occurred while compiling /Users/jkoslowski/dev/scala3-live/src/main/scala/com/example/Examples.scala
scala.MatchError: List() (of class scala.collection.immutable.Nil$) while compiling /Users/jkoslowski/dev/scala3-live/src/main/scala/com/example/Examples.scala
[error] ## Exception when compiling 1 sources to /Users/jkoslowski/dev/scala3-live/target/scala-3.0.0/classes
[error] scala.MatchError: List() (of class scala.collection.immutable.Nil$)
[error] dotty.tools.dotc.transform.Erasure$Boxing$.adaptClosure(Erasure.scala:436)
[error] dotty.tools.dotc.transform.Erasure$Typer.typedClosure(Erasure.scala:1032)
[error] dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:2680)
[error] dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2731)
[error] dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:118)
[error] dotty.tools.dotc.typer.Typer.typed(Typer.scala:2796)
[error] dotty.tools.dotc.typer.Typer.typed(Typer.scala:2800)
[error] dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:2916)
[error] dotty.tools.dotc.typer.Typer.typedBlock(Typer.scala:1018)
[error] dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:2677)
[error] dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2731)
[error] dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:118)
[error] dotty.tools.dotc.typer.Typer.typed(Typer.scala:2796)
[error] dotty.tools.dotc.typer.Typer.typed(Typer.scala:2800)
[error] dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:2916)
[error] dotty.tools.dotc.typer.Typer.$anonfun$34(Typer.scala:2142)
[error] dotty.tools.dotc.typer.PrepareInlineable$.dropInlineIfError(PrepareInlineable.scala:225)
[error] dotty.tools.dotc.typer.Typer.typedDefDef(Typer.scala:2142)
[error] dotty.tools.dotc.transform.Erasure$Typer.typedDefDef(Erasure.scala:955)
[error] dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:2646)
[error] dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2730)
[error] dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:118)
[error] dotty.tools.dotc.typer.Typer.typed(Typer.scala:2796)
[error] dotty.tools.dotc.typer.Typer.typed(Typer.scala:2800)
[error] dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:2822)
[error] dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:2872)
[error] dotty.tools.dotc.transform.Erasure$Typer.typedStats(Erasure.scala:1068)
[error] dotty.tools.dotc.typer.Typer.typedClassDef(Typer.scala:2328)
[error] dotty.tools.dotc.transform.Erasure$Typer.typedClassDef(Erasure.scala:1057)
[error] dotty.tools.dotc.typer.Typer.typedTypeOrClassDef$2(Typer.scala:2657)
[error] dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:2661)
[error] dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2730)
[error] dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:118)
[error] dotty.tools.dotc.typer.Typer.typed(Typer.scala:2796)
[error] dotty.tools.dotc.typer.Typer.typed(Typer.scala:2800)
[error] dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:2822)
[error] dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:2872)
[error] dotty.tools.dotc.transform.Erasure$Typer.typedStats(Erasure.scala:1068)
[error] dotty.tools.dotc.typer.Typer.typedPackageDef(Typer.scala:2451)
[error] dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:2702)
[error] dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:2731)
[error] dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:118)
[error] dotty.tools.dotc.typer.Typer.typed(Typer.scala:2796)
[error] dotty.tools.dotc.typer.Typer.typed(Typer.scala:2800)
[error] dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:2916)
[error] dotty.tools.dotc.transform.Erasure.run(Erasure.scala:132)
[error] dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:303)
[error] scala.collection.immutable.List.map(List.scala:246)
[error] dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:304)
[error] dotty.tools.dotc.Run.runPhases$4$$anonfun$4(Run.scala:205)
[error] scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error] scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error] scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1323)
[error] dotty.tools.dotc.Run.runPhases$5(Run.scala:215)
[error] dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:223)
[error] scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18)
[error] dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:67)
[error] dotty.tools.dotc.Run.compileUnits(Run.scala:230)
[error] dotty.tools.dotc.Run.compileSources(Run.scala:166)
[error] dotty.tools.dotc.Run.compile(Run.scala:150)
[error] dotty.tools.dotc.Driver.doCompile(Driver.scala:39)
[error] dotty.tools.xsbt.CompilerBridgeDriver.run(CompilerBridgeDriver.java:88)
[error] dotty.tools.xsbt.CompilerBridge.run(CompilerBridge.java:22)
[error] sbt.internal.inc.AnalyzingCompiler.compile(AnalyzingCompiler.scala:91)
[error] sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$7(MixedAnalyzingCompiler.scala:186)
[error] scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
[error] sbt.internal.inc.MixedAnalyzingCompiler.timed(MixedAnalyzingCompiler.scala:241)
[error] sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$4(MixedAnalyzingCompiler.scala:176)
[error] sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$4$adapted(MixedAnalyzingCompiler.scala:157)
[error] sbt.internal.inc.JarUtils$.withPreviousJar(JarUtils.scala:239)
[error] sbt.internal.inc.MixedAnalyzingCompiler.compileScala$1(MixedAnalyzingCompiler.scala:157)
[error] sbt.internal.inc.MixedAnalyzingCompiler.compile(MixedAnalyzingCompiler.scala:204)
[error] sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileInternal$1(IncrementalCompilerImpl.scala:528)
[error] sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileInternal$1$adapted(IncrementalCompilerImpl.scala:528)
[error] sbt.internal.inc.Incremental$.$anonfun$apply$5(Incremental.scala:174)
[error] sbt.internal.inc.Incremental$.$anonfun$apply$5$adapted(Incremental.scala:172)
[error] sbt.internal.inc.Incremental$$anon$2.run(Incremental.scala:457)
[error] sbt.internal.inc.IncrementalCommon$CycleState.next(IncrementalCommon.scala:116)
[error] sbt.internal.inc.IncrementalCommon$$anon$1.next(IncrementalCommon.scala:56)
[error] sbt.internal.inc.IncrementalCommon$$anon$1.next(IncrementalCommon.scala:52)
[error] sbt.internal.inc.IncrementalCommon.cycle(IncrementalCommon.scala:261)
[error] sbt.internal.inc.Incremental$.$anonfun$incrementalCompile$8(Incremental.scala:412)
[error] sbt.internal.inc.Incremental$.withClassfileManager(Incremental.scala:499)
[error] sbt.internal.inc.Incremental$.incrementalCompile(Incremental.scala:399)
[error] sbt.internal.inc.Incremental$.apply(Incremental.scala:166)
[error] sbt.internal.inc.IncrementalCompilerImpl.compileInternal(IncrementalCompilerImpl.scala:528)
[error] sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileIncrementally$1(IncrementalCompilerImpl.scala:482)
[error] sbt.internal.inc.IncrementalCompilerImpl.handleCompilationError(IncrementalCompilerImpl.scala:332)
[error] sbt.internal.inc.IncrementalCompilerImpl.compileIncrementally(IncrementalCompilerImpl.scala:420)
[error] sbt.internal.inc.IncrementalCompilerImpl.compile(IncrementalCompilerImpl.scala:137)
[error] sbt.Defaults$.compileIncrementalTaskImpl(Defaults.scala:2346)
[error] sbt.Defaults$.$anonfun$compileIncrementalTask$2(Defaults.scala:2303)
[error] sbt.internal.io.Retry$.apply(Retry.scala:46)
[error] sbt.internal.io.Retry$.apply(Retry.scala:28)
[error] sbt.internal.io.Retry$.apply(Retry.scala:23)
[error] sbt.internal.server.BspCompileTask$.compute(BspCompileTask.scala:31)
[error] sbt.Defaults$.$anonfun$compileIncrementalTask$1(Defaults.scala:2299)
[error] scala.Function1.$anonfun$compose$1(Function1.scala:49)
[error] sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62)
[error] sbt.std.Transform$$anon$4.work(Transform.scala:68)
[error] sbt.Execute.$anonfun$submit$2(Execute.scala:282)
[error] sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:23)
[error] sbt.Execute.work(Execute.scala:291)
[error] sbt.Execute.$anonfun$submit$1(Execute.scala:282)
[error] sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:265)
[error] sbt.CompletionService$$anon$2.call(CompletionService.scala:64)
[error] java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
[error] java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
[error] java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
[error] java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
[error] java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
[error] java.base/java.lang.Thread.run(Thread.java:834)
[error]            
[error] stack trace is suppressed; run last Compile / compileIncremental for the full output
[error] (Compile / compileIncremental) scala.MatchError: List() (of class scala.collection.immutable.Nil$)
[error] Total time: 0 s, completed 21 May 2021, 16:09:51

Related: #12555

Issue Analytics

  • State:closed
  • Created 2 years ago
  • Comments:5 (5 by maintainers)

github_iconTop GitHub Comments

1reaction
LPTKcommented, May 27, 2021

As we only provide given Noop[User] we will never be able to devirtualize the call at compile-time

Note that it works with given Noop[User] with ... (as in my message above).

0reactions
oderskycommented, Apr 7, 2022

I guess classes with only abstract inline defs should not be SAM types.

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