Ensure ClassBTypes constructed from symbol and classfile are identical

A super call (invokespecial) to a default method T.m is only allowed if
the interface T is a direct parent of the class. Super calls are
introduced for example in Mixin when generating forwarder methods:

    trait T { override def clone(): Object = "hi" }
    trait U extends T
    class C extends U

The class C gets a forwarder that invokes T.clone(). During code
generation the interface T is added as direct parent to class C. Note
that T is not a (direct) parent in the frontend type of class C.

This commit stores interfaces that are added to a class during code
generation in the InlineInfo classfile attribute. This allows filtering
the interface list when constructing a ClassBType from a classfile.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala
index a429cfa0f2..a2c521eb91 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala
@@ -1060,8 +1060,10 @@ abstract class BCodeBodyBuilder extends BCodeSkelBuilder {
       val receiverName = internalName(receiverClass)
 
       // super calls are only allowed to direct parents
-      if (style.isSuper && receiverClass.isTraitOrInterface && !cnode.interfaces.contains(receiverName))
+      if (style.isSuper && receiverClass.isTraitOrInterface && !cnode.interfaces.contains(receiverName)) {
+        thisBType.info.get.inlineInfo.lateInterfaces += receiverName
         cnode.interfaces.add(receiverName)
+      }
 
       def needsInterfaceCall(sym: Symbol) = {
         sym.isTraitOrInterface ||