Fix #1423: Fix owners of called methods in CollectSuperCalls.

Author: nicolasstucki

src/dotty/tools/backend/jvm/CollectSuperCalls.scala

@@ -1,7 +1,7 @@
 package dotty.tools.backend.jvm
 
-import dotty.tools.dotc.ast.tpd._
-import dotty.tools.dotc.ast.Trees
+import dotty.tools.dotc.ast.tpd
+import dotty.tools.dotc.ast.Trees._
 import dotty.tools.dotc.core.Contexts.Context
 import dotty.tools.dotc.core.Symbols._
 import dotty.tools.dotc.transform.TreeTransforms.{MiniPhaseTransform, TransformerInfo}
@@ -17,14 +17,14 @@ class CollectSuperCalls extends MiniPhaseTransform {
 
   def phaseName: String = "collectSuperCalls"
 
-  override def transformSuper(tree: Super)(implicit ctx: Context, info: TransformerInfo): Tree = {
+  override def transformSelect(tree: tpd.Select)(implicit ctx: Context, info: TransformerInfo): tpd.Tree = {
     tree match {
-      case Trees.Super(qual: This, mix) if mix.nonEmpty =>
+      case Select(Super(qual, mix), _) if mix.nonEmpty =>
         val classSymbol = qual.symbol.asClass.classSymbol
-        registerSuperCall(classSymbol, tree.tpe.baseClasses.head)
+        registerSuperCall(classSymbol, tree.symbol.owner.asClass)
       case _ =>
     }
-    super.transformSuper(tree)
+    super.transformSelect(tree)
   }
 
   private def registerSuperCall(sym: ClassSymbol, calls: ClassSymbol)(implicit ctx: Context) = {

tests/run/i1423.check

@@ -0,0 +1,5 @@
+3
+2
+3
+1
+0

tests/run/i1423.scala

@@ -0,0 +1,20 @@
+class B { def m: Int = 0 }
+class C extends B { override def m = 4 }
+trait T1 extends B { override def m = 1 }
+trait T2 extends T1 { override def m = 2 }
+trait T3 extends T1 { override def m = 3 }
+
+trait T4 extends T1
+class D extends B {
+  def f() = println(super[B].m)
+}
+
+object Test extends C with T2 with T3 with T4 {
+  def main(args: Array[String]): Unit = {
+    println(m)
+    println(super[T2].m)
+    println(super[T3].m)
+    println(super[T4].m)
+    new D().f()
+  }
+}