Simplified and commented makePackageObjPrefixExplicit

Author: odersky

src/dotty/tools/dotc/TypeErasure.scala

@@ -108,7 +108,7 @@ object TypeErasure {
   def erasedRef(tp: Type)(implicit ctx: Context): Type = tp match {
     case tp: TermRef =>
       assert(tp.symbol.exists, tp)
-      val tp1 = ctx.makePackageObjPrefixExplicit(tp, tp.symbol)
+      val tp1 = ctx.makePackageObjPrefixExplicit(tp)
       if (tp1 ne tp) erasedRef(tp1)
       else TermRef(erasedRef(tp.prefix), tp.symbol.asTerm)
     case tp: ThisType =>

src/dotty/tools/dotc/core/TypeOps.scala

@@ -224,9 +224,14 @@ trait TypeOps { this: Context =>
     cls.enter(sym, decls)
   }
 
-  def makePackageObjPrefixExplicit(tpe: NamedType, d: Denotation): Type = {
+  /** If `tpe` is of the form `p.x` where `p` refers to a package
+   *  but `x` is not owned by a package, expand it to
+   *
+   *      p.package.x
+   */
+  def makePackageObjPrefixExplicit(tpe: NamedType): Type = {
     def tryInsert(pkgClass: SymDenotation): Type = pkgClass match {
-      case pkgCls: PackageClassDenotation if !(d.symbol.maybeOwner is Package) =>
+      case pkgCls: PackageClassDenotation if !(tpe.symbol.maybeOwner is Package) =>
         tpe.derivedSelect(pkgCls.packageObj.valRef)
       case _ =>
         tpe

src/dotty/tools/dotc/typer/TypeAssigner.scala

@@ -144,7 +144,7 @@ trait TypeAssigner {
         else if (d.symbol is TypeParamAccessor) // always dereference type param accessors
           ensureAccessible(d.info.bounds.hi, superAccess, pos)
         else
-          ctx.makePackageObjPrefixExplicit(tpe withDenot d, d)
+          ctx.makePackageObjPrefixExplicit(tpe withDenot d)
       case _ =>
         tpe
     }