Fixed an ancient crasher in explicitouter involving singleton

self-types.  Closes #266, review by odersky.

git-svn-id: http://lampsvn.epfl.ch/svn-repos/scala/scala/trunk@23123 5e8d7ff9-d8ef-0310-90f0-a4852d11357a

src/compiler/scala/tools/nsc/ast/TreeDSL.scala

@@ -287,6 +287,7 @@ trait TreeDSL {
     def VAL(name: Name): ValTreeStart           = new ValTreeStart(name)
     def VAL(sym: Symbol): ValSymStart           = new ValSymStart(sym)
 
+    def DEF(name: Name): DefTreeStart = new DefTreeStart(name)
     def DEF(sym: Symbol): DefSymStart = new DefSymStart(sym)
     def AND(guards: Tree*) =
       if (guards.isEmpty) EmptyTree

src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala

@@ -124,8 +124,8 @@ abstract class ExplicitOuter extends InfoTransform
       else tp
     case ClassInfoType(parents, decls, clazz) =>
       var decls1 = decls
-      if (isInner(clazz) && !(clazz hasFlag INTERFACE)) {
-        decls1 = new Scope(decls.toList)
+      if (isInner(clazz) && !clazz.isInterface) {
+        decls1 = decls.cloneScope
         val outerAcc = clazz.newMethod(clazz.pos, nme.OUTER) // 3
         outerAcc expandName clazz
         
@@ -134,7 +134,7 @@ abstract class ExplicitOuter extends InfoTransform
         if (hasOuterField(clazz)) { //2
           val access = if (clazz.isFinal) PRIVATE | LOCAL else PROTECTED
           decls1 enter (
-            clazz.newValue(clazz.pos, nme getterToLocal nme.OUTER)
+            clazz.newValue(clazz.pos, nme.OUTER_LOCAL)
             setFlag (SYNTHETIC | PARAMACCESSOR | access)
             setInfo clazz.outerClass.thisType
           )
@@ -144,7 +144,7 @@ abstract class ExplicitOuter extends InfoTransform
         for (mc <- clazz.mixinClasses) {
           val mixinOuterAcc: Symbol = atPhase(phase.next)(outerAccessor(mc))
           if (mixinOuterAcc != NoSymbol) {
-            if (decls1 eq decls) decls1 = new Scope(decls.toList)
+            if (decls1 eq decls) decls1 = decls.cloneScope
             val newAcc = mixinOuterAcc.cloneSymbol(clazz) 
             newAcc resetFlag DEFERRED setInfo (clazz.thisType memberType mixinOuterAcc)
             decls1 enter newAcc
@@ -239,9 +239,7 @@ abstract class ExplicitOuter extends InfoTransform
         }
         super.transform(tree)
       }
-      finally {
-        outerParam = savedOuterParam
-      }
+      finally outerParam = savedOuterParam
     }
   }
 
@@ -314,12 +312,15 @@ abstract class ExplicitOuter extends InfoTransform
       var rhs: Tree =
         if (outerAcc.isDeferred) EmptyTree
         else This(currentClass) DOT outerField(currentClass)
-
-      typedPos(currentClass.pos)(DEF(outerAcc) === rhs)
+      
+      /** If we don't re-type the tree, we see self-type related crashes like #266.
+       */
+      localTyper typed {
+        (DEF(outerAcc) withType null) === rhs
+      } setPos currentClass.pos
     }
 
-    /** The definition tree of the outer accessor for class
-     * <code>mixinClass</code>.
+    /** The definition tree of the outer accessor for class mixinClass.
      *
      *  @param mixinClass The mixin class which defines the abstract outer
      *                    accessor which is implemented by the generated one.
@@ -332,13 +333,12 @@ abstract class ExplicitOuter extends InfoTransform
         if (mixinClass.owner.isTerm) THIS(mixinClass.owner.enclClass)
         else gen.mkAttributedQualifier(currentClass.thisType baseType mixinClass prefix)
       
-      localTyper typed { 
+      localTyper typed {
         DEF(outerAcc) === {
           // Need to cast for nested outer refs in presence of self-types. See ticket #3274.
-          // @S: atPos not good enough because of nested atPos in DefDef method, which gives position from wrong class!
-          transformer.transform(path) AS_ANY outerAcc.info.resultType setPos currentClass.pos
+          transformer.transform(path) AS_ANY outerAcc.info.resultType
         }
-      }  setPos currentClass.pos
+      } setPos currentClass.pos
     }
     
     /** If FLAG is set on symbol, sets notFLAG (this exists in anticipation of generalizing). */

test/files/run/bug266.scala

@@ -0,0 +1,23 @@
+// #266, yee ha
+
+trait O {
+  self: Test.type =>
+  
+  Nil foreach identity
+  
+  def f = (1 to 10).toList map identity
+}
+
+object Test extends O {
+  def main(args: Array[String]): Unit = {
+    assert(f.sum == 55)
+  }
+}
+
+// Don't lose this part, it's what (formerly) crashes.
+// For some reason the one actually mixed in does not.
+object Pip
+
+trait P { self: Pip.type =>
+  Nil foreach identity
+}