Fix scala#7048: WIP

Author: nicolasstucki

compiler/src/dotty/tools/dotc/transform/PCPCheckAndHeal.scala

@@ -107,7 +107,29 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
   }
 
   /** Check and heal all named types and this-types in a given type for phase consistency. */
-  private def checkType(pos: SourcePosition)(implicit ctx: Context): TypeMap = new TypeMap {
+  private def checkType(pos: SourcePosition)(implicit ctx: Context): TypeMap = {
+    // tests/pos/i5954.scala failed
+    // tests/pos/i5954.scala failed
+    // tests/pos/i5954b.scala failed
+    // tests/pos/i5954b.scala failed
+    // tests/pos/i5954c.scala failed
+    // tests/pos/i5954c.scala failed
+    // tests/pos/i5954d.scala failed
+    // tests/pos/i5954d.scala failed
+
+    // tests/pos/i7048c.scala failed
+    // tests/pos/i7048c.scala failed
+    // tests/pos/i7048d.scala failed
+    // tests/pos/i7048d.scala failed
+
+    // tests/run-macros/i7048
+    // tests/run-staging/i6281.scala
+
+    // println()
+    // println("+++++++++++++++++++++++++=")
+    // println()
+    // println()
+    new TypeMap {
     def apply(tp: Type): Type = reporting.trace(i"check type level $tp at $level") {
       tp match {
         case tp: TypeRef if tp.symbol.isSplice =>
@@ -119,7 +141,31 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
           // Replace it with a properly encoded type splice. This is the normal for expected for type splices.
           tp.prefix.select(tpnme.splice)
         case tp: NamedType =>
-          checkSymLevel(tp.symbol, tp, pos) match {
+
+          def isPathOK(tp1: Type): Boolean = {
+
+            // println("> " + tp1)
+
+            tp1 match {
+            case tp: TermRef => tp.symbol.isStaticOwner || isPathOK(tp.prefix)
+            case tp: TypeRef => tp.symbol.is(Package) || isPathOK(tp.prefix)
+            case ThisType(tref) => isPathOK(tref)
+            case _: SkolemType => true
+            case _ => false
+          }}
+
+            // println("++++++++++++++++++++++++")
+            // println(tp.show)
+            // println(tp)
+            // println(level)
+            // println(levelOK(tp.symbol))
+            // println(levelOf(tp.symbol))
+            // println(isPathOK(tp))
+            // println()
+            // println()
+          // }
+          if (isPathOK(tp)) tp
+          else checkSymLevel(tp.symbol, tp, pos) match {
             case Some(tpRef) => tpRef.tpe
             case _ =>
               if (tp.symbol.is(Param)) tp
@@ -132,7 +178,7 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
           mapOver(tp)
       }
     }
-  }
+  }}
 
   /** Check reference to `sym` for phase consistency, where `tp` is the underlying type
    *  by which we refer to `sym`. If it is an inconsistent type try construct a healed type for it.
@@ -171,7 +217,7 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
             sym.isClass // reference to this in inline methods
           )
     case None =>
-      !sym.is(Param) || levelOK(sym.owner)
+      !(sym.is(Param) || sym.isType) || levelOK(sym.owner)
   }
 
   /** Try to heal phase-inconsistent reference to type `T` using a local type definition.