Reflection's path dependent TypeRepr loses information about the prefix when converting to symbol

[jchyb]

Compiler version

If you're not sure what version you're using, run print scalaVersion from sbt
(if you're running scalac manually, use scalac -version instead).

Minimized code

Macro.scala:

import scala.quoted._

inline def pdTypeMacro[T]: Unit = ${ pdTypeMacroImpl[T] }

def pdTypeMacroImpl[T](using quotes: Quotes, tpe: Type[T]): Expr[Unit] =
  import quotes.reflect.*
  val sym = TypeRepr.of[T].classSymbol.get
  println(sym.typeRef) // TypeRef(ThisType(TypeRef(ThisType(TypeRef(NoPrefix,module class <empty>)),class Outer)),class Inner)
  val mod = Ref(sym.companionModule)
  '{
    ${mod.asExpr}
    ???
  }

Main.scala:

class Outer:
  case class Inner(a: String = "test", b: Int = 23)

object Test:
  def main(args: Array[String]): Unit =
    val outer = Outer()
    pdTypeMacro[outer.Inner]

Output

WIth -Xcheck-macros

-- Error: main.scala:7:15 ------------------------------------------------------
7 |    pdTypeMacro[outer.Inner]
  |    ^^^^^^^^^^^^^^^^^^^^^^^^
  |Malformed tree was found while expanding macro with -Xcheck-macros.
  |The tree does not conform to the compiler's tree invariants.
  |
  |Macro was:
  |scala.quoted.runtime.Expr.splice[scala.Unit](((contextual$1: scala.quoted.Quotes) ?=> macro$package.pdTypeMacroImpl[outer.Inner](contextual$1, scala.quoted.Type.of[outer.Inner](contextual$1))))
  |
  |The macro returned:
  |{
  |  Outer.this.Inner
  |  scala.Predef.???
  |}
  |
  |Error:
  |assertion failed: error while typing Outer.this, method main is not contained in class Outer
  |
  |stacktrace available when compiling with `-Ydebug`
  |-----------------------------------------------------------------------------
  |Inline stack trace
  |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  |This location contains code that was inlined from macro.scala:3
3 |inline def pdTypeMacro[T]: Unit = ${ pdTypeMacroImpl[T] }
  |                                  ^^^^^^^^^^^^^^^^^^^^^^^
   -----------------------------------------------------------------------------

Without:

  exception while retyping Outer.this of class This # -1

  An unhandled exception was thrown in the compiler.
  Please file a crash report here:
  https://github.com/scala/scala3/issues/new/choose
  For non-enriched exceptions, compile with -Yno-enrich-error-messages.

     while compiling: main.scala
        during phase: MegaPhase{elimErasedValueType, pureStats, vcElideAllocations, etaReduce, arrayApply, elimPolyFunction, tailrec, completeJavaEnums, mixin, lazyVals, memoize, nonLocalReturns, capturedVars}
                mode: Mode(ImplicitsEnabled)
     library version: version 2.13.12
    compiler version: version 3.4.2-RC1-bin-SNAPSHOT-nonbootstrapped-git-3694d95
            settings: -classpath /Users/jchyb/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.12/scala-library-2.13.12.jar:/Users/jchyb/Documents/workspace/dotty/library/../out/bootstrap/scala3-library-bootstrapped/scala-3.4.2-RC1-bin-SNAPSHOT-nonbootstrapped/scala3-library_3-3.4.2-RC1-bin-SNAPSHOT.jar
Exception in thread "main" 
  Exception while compiling macro.scala, main.scala

  An unhandled exception was thrown in the compiler.
  Please file a crash report here:
  https://github.com/scala/scala3/issues/new/choose
  For non-enriched exceptions, compile with -Yno-enrich-error-messages.

     while compiling: <no file>
        during phase: parser
                mode: Mode()
     library version: version 2.13.12
    compiler version: version 3.4.2-RC1-bin-SNAPSHOT-nonbootstrapped-git-3694d95
            settings: -classpath /Users/jchyb/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.12/scala-library-2.13.12.jar:/Users/jchyb/Documents/workspace/dotty/library/../out/bootstrap/scala3-library-bootstrapped/scala-3.4.2-RC1-bin-SNAPSHOT-nonbootstrapped/scala3-library_3-3.4.2-RC1-bin-SNAPSHOT.jar
java.lang.AssertionError: assertion failed: missing outer accessor in object Test
        at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:8)
        at dotty.tools.dotc.transform.ExplicitOuter$.dotty$tools$dotc$transform$ExplicitOuter$$$outerParamAccessor(ExplicitOuter.scala:237)
        at dotty.tools.dotc.transform.ExplicitOuter$OuterOps$.loop$1(ExplicitOuter.scala:474)
        at dotty.tools.dotc.transform.ExplicitOuter$OuterOps$.path$extension(ExplicitOuter.scala:483)
        at dotty.tools.dotc.transform.Erasure$Typer.typedThis(Erasure.scala:804)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3124)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3207)
        at dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:174)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3284)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3281)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3288)
        at dotty.tools.dotc.transform.Erasure$Typer.typedSelect(Erasure.scala:671)
        at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:3098)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3206)
        at dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:174)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3284)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3288)
        at dotty.tools.dotc.typer.ReTyper.typedInlined(ReTyper.scala:100)
        at dotty.tools.dotc.transform.Erasure$Typer.typedInlined(Erasure.scala:904)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3146)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3207)
        at dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:174)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3284)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3288)
        at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:3337)
        at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:3356)
        at dotty.tools.dotc.transform.Erasure$Typer.typedStats(Erasure.scala:1073)
        at dotty.tools.dotc.typer.Typer.typedBlockStats(Typer.scala:1197)
        at dotty.tools.dotc.typer.Typer.typedBlock(Typer.scala:1201)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3131)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3207)
        at dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:174)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3284)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3288)
        at dotty.tools.dotc.typer.ReTyper.typedInlined(ReTyper.scala:100)
        at dotty.tools.dotc.transform.Erasure$Typer.typedInlined(Erasure.scala:904)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3146)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3207)
        at dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:174)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3284)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3288)
        at dotty.tools.dotc.transform.Erasure$Typer.typedTyped(Erasure.scala:627)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3128)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3207)
        at dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:174)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3284)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3281)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3288)
        at dotty.tools.dotc.typer.ReTyper.typedInlined(ReTyper.scala:100)
        at dotty.tools.dotc.transform.Erasure$Typer.typedInlined(Erasure.scala:904)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3146)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3207)
        at dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:174)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3284)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3288)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3399)
        at dotty.tools.dotc.typer.Typer.typedBlock(Typer.scala:1204)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3131)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3207)
        at dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:174)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3284)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3288)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3399)
        at dotty.tools.dotc.typer.Typer.$anonfun$63(Typer.scala:2613)
        at dotty.tools.dotc.inlines.PrepareInlineable$.dropInlineIfError(PrepareInlineable.scala:256)
        at dotty.tools.dotc.typer.Typer.typedDefDef(Typer.scala:2613)
        at dotty.tools.dotc.transform.Erasure$Typer.typedDefDef(Erasure.scala:960)
        at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:3105)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3206)
        at dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:174)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3284)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3288)
        at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:3310)
        at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:3356)
        at dotty.tools.dotc.transform.Erasure$Typer.typedStats(Erasure.scala:1073)
        at dotty.tools.dotc.typer.Typer.typedClassDef(Typer.scala:2800)
        at dotty.tools.dotc.transform.Erasure$Typer.typedClassDef(Erasure.scala:1049)
        at dotty.tools.dotc.typer.Typer.typedTypeOrClassDef$1(Typer.scala:3111)
        at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:3115)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3206)
        at dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:174)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3284)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3288)
        at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:3310)
        at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:3356)
        at dotty.tools.dotc.transform.Erasure$Typer.typedStats(Erasure.scala:1073)
        at dotty.tools.dotc.typer.Typer.typedPackageDef(Typer.scala:2933)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3157)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3207)
        at dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:174)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3284)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3288)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3399)
        at dotty.tools.dotc.transform.Erasure.run(Erasure.scala:144)
        at dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:354)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.immutable.List.foreach(List.scala:333)
        at dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:360)
        at dotty.tools.dotc.Run.runPhases$1$$anonfun$1(Run.scala:315)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1323)
        at dotty.tools.dotc.Run.runPhases$1(Run.scala:337)
        at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:350)
        at dotty.tools.dotc.Run.compileUnits$$anonfun$adapted$1(Run.scala:360)
        at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:69)
        at dotty.tools.dotc.Run.compileUnits(Run.scala:360)
        at dotty.tools.dotc.Run.compileUnits(Run.scala:267)
        at dotty.tools.dotc.Run.compileSuspendedUnits(Run.scala:371)
        at dotty.tools.dotc.Driver.finish(Driver.scala:57)
        at dotty.tools.dotc.Driver.doCompile(Driver.scala:38)
        at dotty.tools.dotc.Driver.process(Driver.scala:196)
        at dotty.tools.dotc.Driver.process(Driver.scala:164)
        at dotty.tools.dotc.Driver.process(Driver.scala:176)
        at dotty.tools.dotc.Driver.main(Driver.scala:206)
        at dotty.tools.dotc.Main.main(Main.scala)

## Expectation This is not a high priority, as this is caught by `-Xcheck-macros` after all, but I would expect Symbols to represent more correct information about the types. As it is now, any path dependent types like `outer.Inner` effectively become Outer.this.Inner, which is incorrect.

[xuwei-k]

Maybe same issue in slick TableQuery macro 😢

https://github.com/slick/slick/blob/v3.6.0/slick/src/main/scala-3/slick/lifted/TableQuery.scala#L47

build.sbt

libraryDependencies += "com.typesafe.slick" %% "slick" % "3.6.0"

scalaVersion := "3.6.4"

scalacOptions += "-Xprint:all"

A.scala

package example

import slick.jdbc.JdbcProfile

case class C(x: Int)

trait A {
  protected val profile: JdbcProfile
  import profile.api.*

  protected class B(tag: Tag) extends Table[C](tag, "my_table") {
    override def * = ???
  }
}

trait D extends A {
  import profile.api.*
  val query = TableQuery[B]
}

compile result

[error] 18 |  val query = TableQuery[B]
[error]    |              ^^^^^^^^^^^^^
[error]    |              Found:    A.this.B
[error]    |              Required: D.this.B

-Xprint result

val query: slick.lifted.TableQuery[D.this.B] =
  slick.lifted.TableQuery.apply[D.this.B](
    (tag: slick.lifted.Tag) => new A.this.B(tag)):
    slick.lifted.TableQuery[D.this.B]

workaround 1

-  val query = TableQuery[B]
+  type E = B
+
+  val query = TableQuery[E]

workaround 2

+
+  val query = TableQuery[B]
 }
 
 trait D extends A {
   import profile.api.*
-
-  val query = TableQuery[B]
 }

workaround 3

-  val query = TableQuery[B]
+  val query = TableQuery[B](new B(_))

[xuwei-k]

• fix Scala 3 TableQuery macro slick/slick#3151 😭