Pattern term of CaseDef is an internal ClassInfo that crashes when matched on

[tschuchortdev]

Compiler version

3.3.3

Minimized code

case class Foo()
extension (self: Foo) {
  inline def matchCustom[R](inline matchExpr: Foo => R): R = ${matchCustomImpl[R]('self, 'matchExpr)}
}

private def matchCustomImpl[R: Type](self: Expr[Foo], matchExpr: Expr[Foo => R])(using q: Quotes): Expr[R] = {
  import q.reflect.*

  printTastyTree(matchExpr.asTerm)

  val cases = matchExpr.asTerm match
    case Inlined(_, _,
      Block(
        List(
          DefDef(
            lambdaName,
            List(TermParamClause(List(ValDef(lambdaParamName, lambdaParamType, _)))),
            _,
            Some(Match(Ident(matchVarName), cases))
          )
        ),
        Closure(Ident(closureName), _)
      )
    ) if closureName == lambdaName && matchVarName == lambdaParamName =>
        cases

    case _ => report.errorAndAbort("Must be a lambda with top-level match expression", matchExpr)

  val _ = cases.map { case CaseDef(pattern, guard, _) =>
      val t = pattern.symbol.termRef.simplified.widenTermRefByName
      // Assertion error here:
      t.asType match
         case '[t] => ()
  }

  '{ $matchExpr($self) }
}


// other file --------------------
val foo = Foo()

foo.matchCustom {
   case _: Any => ()
}

Output (click arrow to expand)

Exception occurred while executing macro expansion.
[error]    |java.lang.AssertionError: assertion failed: ClassInfo(ThisType(TypeRef(NoPrefix,module class scala)), class Any, List())

foo.matchCustom {
[error]    |    ^
[error]    |Exception occurred while executing macro expansion.
[error]    |java.lang.AssertionError: assertion failed: ClassInfo(ThisType(TypeRef(NoPrefix,module class scala)), class Any, List())
[error]    |    at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:8)
[error]    |    at dotty.tools.dotc.core.Types$TypeBounds.<init>(Types.scala:5178)
[error]    |    at dotty.tools.dotc.core.Types$RealTypeBounds.<init>(Types.scala:5254)
[error]    |    at dotty.tools.dotc.core.Types$TypeBounds$.apply(Types.scala:5298)
[error]    |    at dotty.tools.dotc.core.Types$TypeBounds.derivedTypeBounds(Types.scala:5186)
[error]    |    at dotty.tools.dotc.core.ConstraintHandling.op$proxy2$1(ConstraintHandling.scala:314)
[error]    |    at dotty.tools.dotc.core.ConstraintHandling.addOneBound(ConstraintHandling.scala:314)
[error]    |    at dotty.tools.dotc.core.ConstraintHandling.addOneBound$(ConstraintHandling.scala:29)
[error]    |    at dotty.tools.dotc.core.ProperGadtState.addOneBound(GadtConstraint.scala:286)
[error]    |    at dotty.tools.dotc.core.ConstraintHandling.addBoundTransitively(ConstraintHandling.scala:370)
[error]    |    at dotty.tools.dotc.core.ConstraintHandling.addBoundTransitively$(ConstraintHandling.scala:29)
[error]    |    at dotty.tools.dotc.core.ProperGadtState.addBoundTransitively(GadtConstraint.scala:286)
[error]    |    at dotty.tools.dotc.core.GadtState.addBound(GadtConstraint.scala:232)
[error]    |    at dotty.tools.dotc.core.GadtState.addBound$(GadtConstraint.scala:153)
[error]    |    at dotty.tools.dotc.core.ProperGadtState.addBound(GadtConstraint.scala:286)
[error]    |    at dotty.tools.dotc.core.TypeComparer.gadtAddBound(TypeComparer.scala:119)
[error]    |    at dotty.tools.dotc.core.TypeComparer.narrowGADTBounds(TypeComparer.scala:2071)
[error]    |    at dotty.tools.dotc.core.TypeComparer.compareGADT$1(TypeComparer.scala:567)
[error]    |    at dotty.tools.dotc.core.TypeComparer.thirdTryNamed$1(TypeComparer.scala:571)
[error]    |    at dotty.tools.dotc.core.TypeComparer.thirdTry$1(TypeComparer.scala:625)
[error]    |    at dotty.tools.dotc.core.TypeComparer.secondTry$1(TypeComparer.scala:550)
[error]    |    at dotty.tools.dotc.core.TypeComparer.compareNamed$1(TypeComparer.scala:331)
[error]    |    at dotty.tools.dotc.core.TypeComparer.firstTry$1(TypeComparer.scala:337)
[error]    |    at dotty.tools.dotc.core.TypeComparer.recur(TypeComparer.scala:1471)
[error]    |    at dotty.tools.dotc.core.TypeComparer.isSubType(TypeComparer.scala:208)
[error]    |    at dotty.tools.dotc.core.TypeComparer.isSubType(TypeComparer.scala:218)
[error]    |    at dotty.tools.dotc.core.TypeComparer.topLevelSubType(TypeComparer.scala:128)
[error]    |    at dotty.tools.dotc.core.TypeComparer$.topLevelSubType(TypeComparer.scala:2942)
[error]    |    at dotty.tools.dotc.core.Types$Type.$less$colon$less(Types.scala:1062)
[error]    |    at scala.quoted.runtime.impl.QuoteMatcher.runMatch$1(QuoteMatcher.scala:380)
[error]    |    at scala.quoted.runtime.impl.QuoteMatcher.$eq$qmark$eq(QuoteMatcher.scala:451)
[error]    |    at scala.quoted.runtime.impl.QuoteMatcher.liftedTree1$1(QuoteMatcher.scala:132)
[error]    |    at scala.quoted.runtime.impl.QuoteMatcher.treeMatch(QuoteMatcher.scala:133)
[error]    |    at scala.quoted.runtime.impl.QuotesImpl$TypeMatch$.unapply(QuotesImpl.scala:3179)
[error]    |    at com.tschuchort.hkd.HkdFor$package$.matchCustomImpl$$anonfun$1(HkdFor.scala:51)
[error]    |    at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
[error]    |    at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
[error]    |    at scala.collection.immutable.List.map(List.scala:246)
[error]    |    at com.tschuchort.hkd.HkdFor$package$.matchCustomImpl(HkdFor.scala:55)
[error]    |    at com.tschuchort.hkd.HkdFor$package$.inline$matchCustomImpl(HkdFor.scala:25)
[error]    |
[error] 58 |      case _: Any => ()
[error] 59 |    }
[error]    |----------------------------------------------------------------------------
[error]    |Inline stack trace
[error]    |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
[error]    |This location contains code that was inlined from Macro.scala:22
[error] 22 |  inline def matchCustom[R](inline matchExpr: Foo => R): R = ${matchCustomImpl[R]('self, 'matchExpr)}
[error]    |                                                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[error]     ----------------------------------------------------------------------------

The same kind of issue also occurs sometimes when only matching on the TypeRepr directly instead of the quoted Type.

[jchyb]

Minimised:
Main.scala:

def main() = matchCustom()

Macro.scala:

import scala.quoted._

inline def matchCustom(): Unit = ${ matchCustomImpl }

private def matchCustomImpl(using q: Quotes): Expr[Unit] = {
  import q.reflect.*
  val any = TypeRepr.of[Any].typeSymbol
  println(any.termRef.widenTermRefByName) // should not be `ClassInfo`
  any.termRef.widenTermRefByName.asType match
    case '[t] => ()
  '{ () }
}