Compiler crash when annotated types contain certain trees

[mbovel]

Compiler version

348729e

Minimized code

// tests/pos/tasty-no-address.scala
import scala.annotation.Annotation
class myRefined[T](f: T => Boolean) extends Annotation

class Box[T](val x: T)
class Box2(val x: Int)

class A(a: String @myRefined((x: Int) => Box(3).x == 3)) // crash
class A2(a2: String @myRefined((x: Int) => Box2(3).x == 3)) // works

Output (click arrow to expand)

> scalac tests/pos/tasty-no-address.scala
[info] running (fork) dotty.tools.dotc.Main -classpath /Users/mbovel/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.10/scala-library-2.13.10.jar:/Users/mbovel/dotty/library/../out/bootstrap/scala3-library-bootstrapped/scala-3.3.2-RC1-bin-SNAPSHOT-nonbootstrapped/scala3-library_3-3.3.2-RC1-bin-SNAPSHOT.jar tests/pos/tasty-no-address.scala
error when pickling tree def $anonfun(x: Int): Boolean = new Box[Int](3).x.==(3)
error when pickling tree {
  def $anonfun(x: Int): Boolean = new Box[Int](3).x.==(3)
  closure($anonfun)
}
error when pickling tree new myRefined[Int](
  {
    def $anonfun(x: Int): Boolean = new Box[Int](3).x.==(3)
    closure($anonfun)
  }
)
error when pickling tree String @myRefined[Int](
  {
    def $anonfun(x: Int): Boolean = new Box[Int](3).x.==(3)
    closure($anonfun)
  }
)
error when pickling tree def <init>(
  a:
    String @myRefined[Int](
      {
        def $anonfun(x: Int): Boolean = new Box[Int](3).x.==(3)
        closure($anonfun)
      }
    )
): Unit
error when pickling tree (
  a:
    String @myRefined[Int](
      {
        def $anonfun(x: Int): Boolean = new Box[Int](3).x.==(3)
        closure($anonfun)
      }
    )
) extends Object() {
  private[this] val a:
    
      String @myRefined[Int](
        {
          def $anonfun(x: Int): Boolean = new Box[Int](3).x.==(3)
          closure($anonfun)
        }
      )
    
}
error when pickling tree @SourceFile("tests/pos/tasty-no-address.scala") class A(
  a:
    String @myRefined[Int](
      {
        def $anonfun(x: Int): Boolean = new Box[Int](3).x.==(3)
        closure($anonfun)
      }
    )
) extends Object() {
  private[this] val a:
    
      String @myRefined[Int](
        {
          def $anonfun(x: Int): Boolean = new Box[Int](3).x.==(3)
          closure($anonfun)
        }
      )
    
}
error when pickling tree package <empty> {
  import scala.annotation.Annotation
  @SourceFile("tests/pos/tasty-no-address.scala") class A(
    a:
      String @myRefined[Int](
        {
          def $anonfun(x: Int): Boolean = new Box[Int](3).x.==(3)
          closure($anonfun)
        }
      )
  ) extends Object() {
    private[this] val a:
      
        String @myRefined[Int](
          {
            def $anonfun(x: Int): Boolean = new Box[Int](3).x.==(3)
            closure($anonfun)
          }
        )
      
  }
}

  unhandled exception while running pickler on tests/pos/tasty-no-address.scala

  An unhandled exception was thrown in the compiler.
  Please file a crash report here:
  https://github.com/lampepfl/dotty/issues/new/choose

     while compiling: <no file>
        during phase: <no phase>
                mode: Mode(ImplicitsEnabled)
     library version: version 2.13.10
    compiler version: version 3.3.2-RC1-bin-SNAPSHOT-nonbootstrapped-git-348729e
            settings: -classpath /Users/mbovel/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.10/scala-library-2.13.10.jar:/Users/mbovel/dotty/library/../out/bootstrap/scala3-library-bootstrapped/scala-3.3.2-RC1-bin-SNAPSHOT-nonbootstrapped/scala3-library_3-3.3.2-RC1-bin-SNAPSHOT.jar

                tree: EmptyTree
       tree position: :<unknown>
           tree type: <notype>
              symbol: val <none>
           call site: package <root> in module class <root>

  == Source file context for tree position ==


Exception in thread "main" java.lang.AssertionError: assertion failed: method $anonfun
        at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:8)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleDef(TreePickler.scala:328)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:581)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$5(TreePickler.scala:490)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.immutable.List.foreach(List.scala:333)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:490)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$2(TreePickler.scala:448)
        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(TreePickler.scala:448)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:654)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTpt(TreePickler.scala:319)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleDef(TreePickler.scala:338)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleParam(TreePickler.scala:361)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleParams$$anonfun$2(TreePickler.scala:368)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.immutable.List.foreach(List.scala:333)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleParams(TreePickler.scala:368)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleParamss$1(TreePickler.scala:574)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$15(TreePickler.scala:581)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree$$anonfun$adapted$2(TreePickler.scala:581)
        at scala.Function0.apply$mcV$sp(Function0.scala:42)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleDef(TreePickler.scala:335)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:581)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleStats$$anonfun$2(TreePickler.scala:373)
        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:373)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:607)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleDef(TreePickler.scala:337)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:583)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleStats$$anonfun$2(TreePickler.scala:373)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.immutable.List.foreach(List.scala:333)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleStats(TreePickler.scala:373)
        at dotty.tools.dotc.core.tasty.TreePickler.pickleTree(TreePickler.scala:623)
        at dotty.tools.dotc.core.tasty.TreePickler.pickle$$anonfun$1(TreePickler.scala:817)
        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:824)
        at dotty.tools.dotc.transform.Pickler.run$$anonfun$1$$anonfun$1(Pickler.scala:90)
        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$$anonfun$1(Pickler.scala:142)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.immutable.List.foreach(List.scala:333)
        at dotty.tools.dotc.transform.Pickler.run(Pickler.scala:142)
        at dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:327)
        at scala.collection.immutable.List.map(List.scala:246)
        at dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:331)
        at dotty.tools.dotc.transform.Pickler.runOn(Pickler.scala:150)
        at dotty.tools.dotc.Run.runPhases$1$$anonfun$1(Run.scala:246)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1321)
        at dotty.tools.dotc.Run.runPhases$1(Run.scala:262)
        at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:270)
        at dotty.tools.dotc.Run.compileUnits$$anonfun$adapted$1(Run.scala:279)
        at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:67)
        at dotty.tools.dotc.Run.compileUnits(Run.scala:279)
        at dotty.tools.dotc.Run.compileSources(Run.scala:194)
        at dotty.tools.dotc.Run.compile(Run.scala:179)
        at dotty.tools.dotc.Driver.doCompile(Driver.scala:37)
        at dotty.tools.dotc.Driver.process(Driver.scala:197)
        at dotty.tools.dotc.Driver.process(Driver.scala:165)
        at dotty.tools.dotc.Driver.process(Driver.scala:177)
        at dotty.tools.dotc.Driver.main(Driver.scala:207)
        at dotty.tools.dotc.Main.main(Main.scala)

Trees with IDs after posttyper

> scalac -Xprint:posttyper -Ximport-suggestion-timeout 0 -Yshow-tree-ids tests/pos/tasty-no-address.scala
[info] running (fork) dotty.tools.dotc.Main -classpath /Users/mbovel/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.10/scala-library-2.13.10.jar:/Users/mbovel/dotty/library/../out/bootstrap/scala3-library-bootstrapped/scala-3.3.2-RC1-bin-SNAPSHOT-nonbootstrapped/scala3-library_3-3.3.2-RC1-bin-SNAPSHOT.jar -Xprint:posttyper -Ximport-suggestion-timeout 0 -Yshow-tree-ids tests/pos/tasty-no-address.scala
[[syntax trees at end of                 posttyper]] // tests/pos/tasty-no-address.scala
package <empty>#195 {
  import scala#31.annotation#33.Annotation#38
  @SourceFile("tests/pos/tasty-no-address.scala"#1088) class myRefined[
    T >: Nothing#695 <: Any#697#699#702](f: T => Boolean#826#828) extends
    annotation.Annotation#56#848#849()#850 {
    T#700#852
    private[this] val f: T => Boolean#853#855
  }#858
  @SourceFile("tests/pos/tasty-no-address.scala"#1105) class Box[
    T >: Nothing#859 <: Any#861#863#866](x: T#64#231) extends Object#870#875#876
    ()#877 {
    T#864#879
    val x: T#880#882
  }#886
  @SourceFile("tests/pos/tasty-no-address.scala"#1110) class Box2(x: Int#77#248)
     extends Object#890#895#896()#897 {
    val x: Int#898#900
  }#904
  @SourceFile("tests/pos/tasty-no-address.scala"#1115) class A(
    a:
      String#90 @myRefined[Int#909](
        {
          def $anonfun(x: Int#100#105): Boolean#911 =
            new Box#953#954#955[Int#956]#1172(3#958)#1174.x#1176.==#1178(3#965)#
              1179
          #1181
          closure($anonfun#915)#916
        }#1182
      )#1187
    #1189
  ) extends Object#980#985#986()#987 {
    private[this] val a:
      
        String @myRefined[Int#909](
          {
            def $anonfun(x: Int#100#105): Boolean#911 =
              new Box#953#954#955[Int#956]#1192(3#958)#1194.x#1196.==#1198(3#965
                )#1199
            #1201
            closure($anonfun#915)#916
          }#1202
        )
      #1206
    #1208
  }#1212
  @SourceFile("tests/pos/tasty-no-address.scala"#1213) class A2(
    a2:
      String#143 @myRefined[Int#999](
        {
          def $anonfun(x: Int#153#158): Boolean#1001 =
            new Box2#1014#1018#1019(3#1020)#1022.x#1024.==#1028(3#1027)#1029#
            1031
          closure($anonfun#1005)#1006
        }#1032
      )#1222
    #1224
  ) extends Object#1042#1047#1048()#1049 {
    private[this] val a2:
      
        String @myRefined[Int#999](
          {
            def $anonfun(x: Int#153#158): Boolean#1001 =
              new Box2#1014#1018#1019(3#1020)#1022.x#1024.==#1028(3#1027)#1029#
              1031
            closure($anonfun#1005)#1006
          }#1032
        )
      #1230
    #1232
  }#1236
}#1237
...

Look at the blocks in the annotations in A: one has ID #1182 and one has the ID #1202, but the inner def $anonfun and associated symbol are the same, hence the problem. The types String @myRefined are also different.

In A2 however, both blocks have ID #1032 and both String @myRefined have id #1232.

[mbovel]

Output when adding -Ydebug-tree-with-id 1029 (where 1029 is the ID of the block in the annotation):

run -Xprint:posttyper -Ystop-after:posttyper -Ximport-suggestion-timeout 0 -Yshow-tree-ids -Ydebug-tree-with-id 1029 tests/pos/tasty-no-address.scala
[info] running (fork) dotty.tools.dotc.Main -classpath /Users/mbovel/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.10/scala-library-2.13.10.jar:/Users/mbovel/dotty/library/../out/bootstrap/scala3-library-bootstrapped/scala-3.3.2-RC1-bin-SNAPSHOT-nonbootstrapped/scala3-library_3-3.3.2-RC1-bin-SNAPSHOT.jar -Xprint:posttyper -Ystop-after:posttyper -Ximport-suggestion-timeout 0 -Yshow-tree-ids -Ydebug-tree-with-id 1029 tests/pos/tasty-no-address.scala
Debug tree (id=1029) creation 
Block(List(DefDef($anonfun,List(List(ValDef(x,Ident(Int),EmptyTree))),TypeTree[TypeRef(TermRef(ThisType(TypeRef(NoPrefix,module class <root>)),object scala),class Boolean)],Apply(Select(Select(Apply(TypeApply(Select(New(Ident(Box)),<init>),List(TypeTree[TypeVar(TypeParamRef(T) -> TypeRef(ThisType(TypeRef(NoPrefix,module class scala)),class Int))])),List(Literal(Constant(3)))),x),==),List(Literal(Constant(3)))))),Closure(List(),Ident($anonfun),EmptyTree))

java.lang.Exception: Stack trace
        at java.base/java.lang.Thread.dumpStack(Thread.java:1380)
        at dotty.tools.dotc.ast.Positioned.allocateId(Positioned.scala:38)
        at dotty.tools.dotc.ast.Positioned.<init>(Positioned.scala:40)
        at dotty.tools.dotc.ast.Trees$Tree.<init>(Trees.scala:51)
        at dotty.tools.dotc.ast.Trees$Block.<init>(Trees.scala:565)
        at dotty.tools.dotc.ast.untpd$.Block(untpd.scala:386)
        at dotty.tools.dotc.ast.Trees$Instance$TreeCopier.Block(Trees.scala:1290)
        at dotty.tools.dotc.ast.tpd$TypedTreeCopier.Block(tpd.scala:678)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformBlock$$anonfun$1$$anonfun$1(tpd.scala:1249)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.loop$2(tpd.scala:1231)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformStats(tpd.scala:1244)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transformStats(PostTyper.scala:499)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformBlock(tpd.scala:1249)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1518)
        at dotty.tools.dotc.transform.MacroTransform$Transformer.transform(MacroTransform.scala:49)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform(PostTyper.scala:490)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform$$anonfun$1(Trees.scala:1605)
        at scala.collection.immutable.List.mapConserve(List.scala:472)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1605)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.app1$1(PostTyper.scala:323)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform$$anonfun$1(PostTyper.scala:335)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.withNoCheckNews(PostTyper.scala:105)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform(PostTyper.scala:335)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transformAnnot(PostTyper.scala:138)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transformAnnot(PostTyper.scala:143)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform(PostTyper.scala:462)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1566)
        at dotty.tools.dotc.transform.MacroTransform$Transformer.transform(MacroTransform.scala:40)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform(PostTyper.scala:381)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.loop$2(tpd.scala:1244)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformStats(tpd.scala:1244)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transformStats(PostTyper.scala:499)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformStats(tpd.scala:1246)
        at dotty.tools.dotc.transform.MacroTransform$Transformer.transform(MacroTransform.scala:47)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform$$anonfun$4$$anonfun$1(PostTyper.scala:372)
        at dotty.tools.dotc.transform.SuperAccessors.wrapTemplate(SuperAccessors.scala:211)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform$$anonfun$4(PostTyper.scala:372)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.withNoCheckNews(PostTyper.scala:105)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform(PostTyper.scala:374)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1572)
        at dotty.tools.dotc.transform.MacroTransform$Transformer.transform(MacroTransform.scala:40)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform(PostTyper.scala:426)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.loop$2(tpd.scala:1244)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformStats(tpd.scala:1244)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transformStats(PostTyper.scala:499)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformStats(tpd.scala:1246)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1580)
        at dotty.tools.dotc.transform.MacroTransform$Transformer.transform(MacroTransform.scala:40)
        at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform(PostTyper.scala:490)
        at dotty.tools.dotc.transform.MacroTransform.run(MacroTransform.scala:18)
        at dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:327)
        at scala.collection.immutable.List.map(List.scala:246)
        at dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:331)
        at dotty.tools.dotc.Run.runPhases$1$$anonfun$1(Run.scala:246)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1321)
        at dotty.tools.dotc.Run.runPhases$1(Run.scala:262)
        at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:270)
        at dotty.tools.dotc.Run.compileUnits$$anonfun$adapted$1(Run.scala:279)
        at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:67)
        at dotty.tools.dotc.Run.compileUnits(Run.scala:279)
        at dotty.tools.dotc.Run.compileSources(Run.scala:194)
        at dotty.tools.dotc.Run.compile(Run.scala:179)
        at dotty.tools.dotc.Driver.doCompile(Driver.scala:37)
        at dotty.tools.dotc.Driver.process(Driver.scala:197)
        at dotty.tools.dotc.Driver.process(Driver.scala:165)
        at dotty.tools.dotc.Driver.process(Driver.scala:177)
        at dotty.tools.dotc.Driver.main(Driver.scala:207)
        at dotty.tools.dotc.Main.main(Main.scala)

[mbovel]

Could the culprit be the following?

https://github.com/lampepfl/dotty/blob/348729e88e780d8a5ee9860a2228631026552a4e/compiler/src/dotty/tools/dotc/transform/PostTyper.scala#L134-L140

Should we map symbols in this case?

[mbovel]

Just to see if it changes something, I tried to always map symbols to fresh ones in transformAnnot with:

diff --git a/compiler/src/dotty/tools/dotc/transform/PostTyper.scala b/compiler/src/dotty/tools/dotc/transform/PostTyper.scala
index ac3dc15092a..43409e5125b 100644
--- a/compiler/src/dotty/tools/dotc/transform/PostTyper.scala
+++ b/compiler/src/dotty/tools/dotc/transform/PostTyper.scala
@@ -19,6 +19,7 @@ import config.Feature
 import util.SrcPos
 import reporting._
 import NameKinds.WildcardParamName
+import dotty.tools.dotc.ast.TreeTypeMap
 
 object PostTyper {
   val name: String = "posttyper"
@@ -84,6 +85,12 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
   val synthMbr: SyntheticMembers = new SyntheticMembers(thisPhase)
   val beanProps: BeanProperties = new BeanProperties(thisPhase)
 
+  def withFreshSymbols(tree: Tree)(using Context): Tree =
+    val tm = new TreeTypeMap():
+      override def withMappedSyms(syms: List[Symbol]): TreeTypeMap =
+        withMappedSyms(syms, mapSymbols(syms, this, mapAlways = true))
+    tm(tree)
+
   private def newPart(tree: Tree): Option[New] = methPart(tree) match {
     case Select(nu: New, _) => Some(nu)
     case _ => None
@@ -135,7 +142,9 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
       val saved = inJavaAnnot
       inJavaAnnot = annot.symbol.is(JavaDefined)
       if (inJavaAnnot) checkValidJavaAnnotation(annot)
-      try transform(annot)
+      try
+        val res = transform(annot)
+        if res != annot then withFreshSymbols(res) else annot
       finally inJavaAnnot = saved
     }

With this change, the file compiles, but the pickling test fails:

$ diff before-pickling.txt after-pickling.txt                              
50,52c50,51
<               x: scala.Int@tests/pos/tasty-no-address.scala<149..152>@tests/pos/tasty-no-address.scala[146..152]@@(x=
<                 tests/pos/tasty-no-address.scala:<146..146>)
<             ): scala.Boolean =
---
>               x: scala.Int@tests/pos/tasty-no-address.scala<149..152>@tests/pos/tasty-no-address.scala<149..152>@@(x=?))
>               : scala.Boolean =
64,66c63,65
<                       tests/pos/tasty-no-address.scala<157..163>
<                   .x:scala.Int>@tests/pos/tasty-no-address.scala<157..165>
<                 .==:((x: scala.Int): scala.Boolean)>@tests/pos/tasty-no-address.scala<157..168>
---
>                       tests/pos/tasty-no-address.scala<157..162>
>                   .x:scala.Int>@tests/pos/tasty-no-address.scala<157..162>
>                 .==:((x: scala.Int): scala.Boolean)>@tests/pos/tasty-no-address.scala<157..162>
69,71c68,70
<             @tests/pos/tasty-no-address.scala[145..154..170]@@($anonfun=tests/pos/tasty-no-address.scala:<154..154>)
<             <closure(<$anonfun:(x: scala.Int): scala.Boolean>@tests/pos/tasty-no-address.scala<170..170>):scala.Int =>
<               scala.Boolean>@tests/pos/tasty-no-address.scala<170..170>
---
>             @tests/pos/tasty-no-address.scala<149..152>@@($anonfun=?)
>             <closure(<$anonfun:(x: scala.Int): scala.Boolean>@tests/pos/tasty-no-address.scala<152..152>):scala.Int =>
>               scala.Boolean>@tests/pos/tasty-no-address.scala<152..152>
73c72
<         :scala.Int => scala.Boolean>@tests/pos/tasty-no-address.scala<145..170>
---
>         :scala.Int => scala.Boolean>@tests/pos/tasty-no-address.scala<149..152>

[mbovel]

The TypeTree of the field private[this] val a is created by:

https://github.com/lampepfl/dotty/blob/348729e88e780d8a5ee9860a2228631026552a4e/compiler/src/dotty/tools/dotc/ast/Desugar.scala#L102-L130

Maybe we should special case the relocate map for AnnotatedType? I tried applying withFreshSymbols to its tree, but that doesn't help.

[Sporarum]

Minimizing a different failing case, I found the following, which I think is related:

import scala.annotation.Annotation
class myRefined(f: ? => Boolean) extends Annotation


def test(axes: Int) = true

trait Tensor:
  def mean(axes: Int): Int @myRefined(_ => test(axes))

class TensorImpl() extends Tensor:
  def mean(axes: Int) = ???

Both the lambda and the subclassing appear to be necessary

Here is the error:

Click to expand

 [info] running (fork) dotty.tools.dotc.Main -classpath /home/quentin/.cache/coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.10/scala-library-2.13.10.jar:/home/quentin/Projects/dotty/library/../out/bootstrap/scala3-library-bootstrapped/scala-3.3.2-RC1-bin-SNAPSHOT-nonbootstrapped/scala3-library_3-3.3.2-RC1-bin-SNAPSHOT.jar tests/pos-custom-args/refinements/trying.scala
 Exception in thread "main" java.lang.AssertionError: assertion failed: unresolved symbols: parameter axes (line 7) #7891 when pickling tests/pos-custom-args/refinements/trying.scala
       at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:8)
       at dotty.tools.dotc.core.tasty.TreePickler.pickle(TreePickler.scala:829)
       at dotty.tools.dotc.transform.Pickler.run$$anonfun$1$$anonfun$1(Pickler.scala:90)
       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$$anonfun$1(Pickler.scala:142)
       at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
       at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
       at scala.collection.immutable.List.foreach(List.scala:333)
       at dotty.tools.dotc.transform.Pickler.run(Pickler.scala:142)
       at dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:327)
       at scala.collection.immutable.List.map(List.scala:246)
       at dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:331)
       at dotty.tools.dotc.transform.Pickler.runOn(Pickler.scala:150)
       at dotty.tools.dotc.Run.runPhases$1$$anonfun$1(Run.scala:246)
       at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
       at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
       at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1321)
       at dotty.tools.dotc.Run.runPhases$1(Run.scala:262)
       at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:270)
       at dotty.tools.dotc.Run.compileUnits$$anonfun$adapted$1(Run.scala:279)
       at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:67)
       at dotty.tools.dotc.Run.compileUnits(Run.scala:279)
       at dotty.tools.dotc.Run.compileSources(Run.scala:194)
       at dotty.tools.dotc.Run.compile(Run.scala:179)
       at dotty.tools.dotc.Driver.doCompile(Driver.scala:37)
       at dotty.tools.dotc.Driver.process(Driver.scala:197)
       at dotty.tools.dotc.Driver.process(Driver.scala:165)
       at dotty.tools.dotc.Driver.process(Driver.scala:177)
       at dotty.tools.dotc.Driver.main(Driver.scala:207)
       at dotty.tools.dotc.Main.main(Main.scala)

 unhandled exception while running pickler on tests/pos-custom-args/refinements/trying.scala

 An unhandled exception was thrown in the compiler.
 Please file a crash report here:
 https://github.com/lampepfl/dotty/issues/new/choose

    while compiling: <no file>
       during phase: <no phase>
                mode: Mode(ImplicitsEnabled)
    library version: version 2.13.10
    compiler version: version 3.3.2-RC1-bin-SNAPSHOT-nonbootstrapped-git-482dfeb
             settings: -classpath /home/quentin/.cache/coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.10/scala-library-2.13.10.jar:/home/quentin/Projects/dotty/library/../out/bootstrap/scala3-library-bootstrapped/scala-3.3.2-RC1-bin-SNAPSHOT-nonbootstrapped/scala3-library_3-3.3.2-RC1-bin-SNAPSHOT.jar

                tree: EmptyTree
       tree position: :<unknown>
          tree type: <notype>
             symbol: val <none>
          call site: package <root> in module class <root>

 == Source file context for tree position ==
 [error] Nonzero exit code returned from runner: 1
 [error] (scala3-compiler / Compile / runMain) Nonzero exit code returned from runner: 1
 [error] Total time: 2 s, completed Jun 8, 2023, 1:14:37 PM