Re-usable method to determine self-ness.

Method isSelfSym decides whether a symbol is the symbol of a self
definition in a class.

Also, make all self symbols private[this]

1 files changed, 18 insertions, 5 deletions

diff --git a/src/dotty/tools/dotc/core/SymDenotations.scala b/src/dotty/tools/dotc/core/SymDenotations.scala
index da83811f1..ae37ab87c 100644
--- a/src/dotty/tools/dotc/core/SymDenotations.scala
+++ b/src/dotty/tools/dotc/core/SymDenotations.scala
@@ -43,14 +43,10 @@ trait SymDenotations { this: Context =>
     if (denot is ValidForever) true
     else try {
       val owner = denot.owner.denot
-      def isSelfSym = owner.infoOrCompleter match {
-        case ClassInfo(_, _, _, _, selfInfo) => selfInfo == denot.symbol
-        case _ => false
-      }
       stillValid(owner) && (
            !owner.isClass
         || (owner.decls.lookupAll(denot.name) contains denot.symbol)
-        || isSelfSym
+        || denot.isSelfSym
         )
     } catch {
       case ex: StaleSymbol => false
@@ -360,6 +356,23 @@ object SymDenotations {
     /** Is this symbol an abstract or alias type? */
     final def isAbstractOrAliasType = isType & !isClass
 
+    /** Is this the denotation of a self symbol of some class?
+     *  This is the case if one of two conditions holds:
+     *  1. It is the symbol referred to in the selfInfo part of the ClassInfo
+     *     which is the type of this symbol's owner.
+     *  2. This symbol is owned by a class, it's selfInfo field refers to a type
+     *     (indicating the self definition does not introduce a name), and the
+     *     symbol's name is "_".
+     *  TODO: Find a more robust way to characterize self symbols, maybe by
+     *       spending a Flag on them?
+     */
+    final def isSelfSym(implicit ctx: Context) = owner.infoOrCompleter match {
+      case ClassInfo(_, _, _, _, selfInfo) =>
+        selfInfo == symbol ||
+          selfInfo.isInstanceOf[Type] && name == nme.WILDCARD
+      case _ => false
+    }
+
     /** Is this definition contained in `boundary`?
      *  Same as `ownersIterator contains boundary` but more efficient.
      */