Bullet-proofing companion objects

Companion class/module computations now also work for local classes and modules. For this to work,
either one of two conditions must be met: (1) some enclosing context refers to a scope that
contains the companions. (2) the context's compilation unit has a typed tree that contains the
companions. (1) is usually true when type-checking, (2) when transforming trees.

Local companions are searched as follows: If (2) holds, we locate the statement sequence containing
the companions by searching down from the root stored in the compilation unit. Otherwise, we search
outwards in the enclosing contexts for a scope containing the
companions.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/dotty/tools/dotc/util/Attachment.scala b/src/dotty/tools/dotc/util/Attachment.scala
index d9e88a135..ec3019bab 100644
--- a/src/dotty/tools/dotc/util/Attachment.scala
+++ b/src/dotty/tools/dotc/util/Attachment.scala
@@ -74,10 +74,10 @@ object Attachment {
       else nx.removeAttachment(key)
     }
 
-    /** The list of all values attached to this container. */
-    final def allAttachments: List[Any] = {
+    /** The list of all keys and values attached to this container. */
+    final def allAttachments: List[(Key[_], Any)] = {
       val nx = next
-      if (nx == null) Nil else nx.value :: nx.allAttachments
+      if (nx == null) Nil else (nx.key, nx.value) :: nx.allAttachments
     }
   }