Merge pull request #303 from dotty-staging/fix-packageObjects-members-erasure

Make erasure insert `.package` in TermRefs to members of package object.

Author: DarkDimius

src/dotty/tools/dotc/TypeErasure.scala

@@ -108,7 +108,9 @@ object TypeErasure {
   def erasedRef(tp: Type)(implicit ctx: Context): Type = tp match {
     case tp: TermRef =>
       assert(tp.symbol.exists, tp)
-      TermRef(erasedRef(tp.prefix), tp.symbol.asTerm)
+      val tp1 = ctx.makePackageObjPrefixExplicit(tp)
+      if (tp1 ne tp) erasedRef(tp1)
+      else TermRef(erasedRef(tp.prefix), tp.symbol.asTerm)
     case tp: ThisType =>
       tp
     case tp =>

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

@@ -2,7 +2,7 @@ package dotty.tools.dotc
 package core
 
 import Contexts._, Types._, Symbols._, Names._, Flags._, Scopes._
-import SymDenotations._
+import SymDenotations._, Denotations.Denotation
 import config.Printers._
 import Decorators._
 import StdNames._
@@ -224,6 +224,25 @@ trait TypeOps { this: Context =>
     cls.enter(sym, decls)
   }
 
+  /** 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 !(tpe.symbol.maybeOwner is Package) =>
+        tpe.derivedSelect(pkgCls.packageObj.valRef)
+      case _ =>
+        tpe
+    }
+    tpe.prefix match {
+      case pre: ThisType if pre.cls is Package => tryInsert(pre.cls)
+      case pre: TermRef if pre.symbol is Package => tryInsert(pre.symbol.moduleClass)
+      case _ => tpe
+    }
+  }
+
   /** If we have member definitions
    *
    *     type argSym v= from

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

@@ -112,21 +112,6 @@ trait TypeAssigner {
    *      that the package object shows up as the prefix.
    */
   def ensureAccessible(tpe: Type, superAccess: Boolean, pos: Position)(implicit ctx: Context): Type = {
-
-    def tryInsertPackageObj(tpe: NamedType, d: Denotation): Type = {
-      def tryInsert(pkgClass: SymDenotation): Type = pkgClass match {
-        case pkgCls: PackageClassDenotation if !(d.symbol.maybeOwner is Package) =>
-          tpe.derivedSelect(pkgCls.packageObj.valRef)
-        case _ =>
-          tpe
-      }
-      tpe.prefix match {
-        case pre: ThisType if pre.cls is Package => tryInsert(pre.cls)
-        case pre: TermRef if pre.symbol is Package => tryInsert(pre.symbol.moduleClass)
-        case _ => tpe
-      }
-    }
-
     def test(tpe: Type, firstTry: Boolean): Type = tpe match {
       case tpe: NamedType =>
         val pre = tpe.prefix
@@ -159,7 +144,7 @@ trait TypeAssigner {
         else if (d.symbol is TypeParamAccessor) // always dereference type param accessors
           ensureAccessible(d.info.bounds.hi, superAccess, pos)
         else
-          tryInsertPackageObj(tpe withDenot d, d)
+          ctx.makePackageObjPrefixExplicit(tpe withDenot d)
       case _ =>
         tpe
     }

test/dotc/tests.scala

@@ -68,6 +68,7 @@ class tests extends CompilerTest {
   @Test def pos_nullarify = compileFile(posDir, "nullarify", "-Ycheck:nullarify" :: Nil)
   @Test def pos_subtyping = compileFile(posDir, "subtyping")
   @Test def pos_t2613 = compileFile(posSpecialDir, "t2613")(allowDeepSubtypes)
+  @Test def pos_packageObj = compileFile(posDir, "i0239")
 
   @Test def pos_all = compileFiles(posDir, failedOther)