Merge pull request #1168 from dotty-staging/fix-#1131

Tweaks to ExplicitOuter and TreeTypeMap

Author: DarkDimius

src/dotty/tools/dotc/ast/TreeTypeMap.scala

@@ -82,7 +82,8 @@ final class TreeTypeMap(
           constr = tmap.transformSub(constr),
           parents = parents mapconserve transform,
           self = tmap.transformSub(self),
-          body = impl.body mapconserve tmap.transform
+          body = impl.body mapconserve
+            (tmap.transform(_)(ctx.withOwner(mapOwner(impl.symbol.owner))))
         ).withType(tmap.mapType(impl.tpe))
     case tree1 =>
       tree1.withType(mapType(tree1.tpe)) match {

src/dotty/tools/dotc/transform/Constructors.scala

@@ -26,7 +26,7 @@ import collection.mutable
  *   - also moves private fields that are accessed only from constructor
  *     into the constructor if possible.
  */
-class Constructors extends MiniPhaseTransform with SymTransformer { thisTransform =>
+class Constructors extends MiniPhaseTransform with IdentityDenotTransformer { thisTransform =>
   import tpd._
 
   override def phaseName: String = "constructors"
@@ -99,18 +99,6 @@ class Constructors extends MiniPhaseTransform with SymTransformer { thisTransfor
     }
   }
 
-  /** Symbols that are owned by either <local dummy> or a class field move into the
-   *  primary constructor.
-   */
-  override def transformSym(sym: SymDenotation)(implicit ctx: Context): SymDenotation = {
-    def ownerBecomesConstructor(owner: Symbol): Boolean =
-      (owner.isLocalDummy || owner.isTerm && !owner.is(MethodOrLazy)) &&
-      owner.owner.isClass
-    if (ownerBecomesConstructor(sym.owner))
-      sym.copySymDenotation(owner = sym.owner.enclosingClass.primaryConstructor)
-    else sym
-  }
-
   /** @return true  if after ExplicitOuter, all references from this tree go via an
    *                outer link, so no parameter accessors need to be rewired to parameters
    */

src/dotty/tools/dotc/transform/ExplicitOuter.scala

@@ -212,27 +212,34 @@ object ExplicitOuter {
   /** Tree references an outer class of `cls` which is not a static owner.
    */
   def referencesOuter(cls: Symbol, tree: Tree)(implicit ctx: Context): Boolean = {
-    def isOuter(sym: Symbol) =
+    def isOuterSym(sym: Symbol) =
       !sym.isStaticOwner && cls.isProperlyContainedIn(sym)
+    def isOuterRef(ref: Type): Boolean = ref match {
+      case ref: ThisType =>
+        isOuterSym(ref.cls)
+      case ref: TermRef =>
+        if (ref.prefix ne NoPrefix)
+          !ref.symbol.isStatic && isOuterRef(ref.prefix)
+        else if (ref.symbol is Hoistable)
+          // ref.symbol will be placed in enclosing class scope by LambdaLift, so it might need
+          // an outer path then.
+          isOuterSym(ref.symbol.owner.enclosingClass)
+        else
+          // ref.symbol will get a proxy in immediately enclosing class. If this properly
+          // contains the current class, it needs an outer path.
+          ctx.owner.enclosingClass.owner.enclosingClass.isContainedIn(ref.symbol.owner)
+      case _ => false
+    }
+    def hasOuterPrefix(tp: Type) = tp match {
+      case TypeRef(prefix, _) => isOuterRef(prefix)
+      case _ => false
+    }
     tree match {
-      case thisTree @ This(_) =>
-        isOuter(thisTree.symbol)
-      case id: Ident =>
-        id.tpe match {
-          case ref @ TermRef(NoPrefix, _) =>
-            if (ref.symbol is Hoistable)
-              // ref.symbol will be placed in enclosing class scope by LambdaLift, so it might need
-              // an outer path then.
-              isOuter(ref.symbol.owner.enclosingClass)
-            else
-              // ref.symbol will get a proxy in immediately enclosing class. If this properly
-              // contains the current class, it needs an outer path.
-              ctx.owner.enclosingClass.owner.enclosingClass.isContainedIn(ref.symbol.owner)
-          case _ => false
-        }
+      case _: This | _: Ident => isOuterRef(tree.tpe)
       case nw: New =>
         val newCls = nw.tpe.classSymbol
-        isOuter(newCls.owner.enclosingClass) ||
+        isOuterSym(newCls.owner.enclosingClass) ||
+        hasOuterPrefix(nw.tpe) ||
         newCls.owner.isTerm && cls.isProperlyContainedIn(newCls)
           // newCls might get proxies for free variables. If current class is
           // properly contained in newCls, it needs an outer path to newCls access the

src/dotty/tools/dotc/transform/Mixin.scala

@@ -140,8 +140,8 @@ class Mixin extends MiniPhaseTransform with SymTransformer { thisTransform =>
           val vsym = stat.symbol
           val isym = initializer(vsym)
           val rhs = Block(
-            initBuf.toList.map(_.changeOwner(impl.symbol, isym)),
-            stat.rhs.changeOwner(vsym, isym).wildcardToDefault)
+            initBuf.toList.map(_.changeOwnerAfter(impl.symbol, isym, thisTransform)),
+            stat.rhs.changeOwnerAfter(vsym, isym, thisTransform).wildcardToDefault)
           initBuf.clear()
           cpy.DefDef(stat)(rhs = EmptyTree) :: DefDef(isym, rhs) :: Nil
         case stat: DefDef if stat.symbol.isSetter =>

tests/pos/i1131.scala

@@ -0,0 +1,14 @@
+class Outer {
+  class Inner
+}
+
+trait MustBeATrait {
+  val o = new Outer
+  val inner = {
+    class C {
+      new o.Inner
+    }
+    new C
+  }
+  val inner2 = new o.Inner {}
+}