Reworked TermRef handling

The main problem with TermRef handling was that signatures were not always tracked correctly.

New invariant: A TermRef that points to a symbol is always a TermRefWithSig, and the signature
is the one of the corresponding member.

We achieve this by sometimes generating a new TermRefWithSig if a TermRef gets a denotation.

One possible simplification would be to always store a signature in a TermRef.

There's still a problem in TermRefWithSig#newLikeThis, which currently works only if the previously stored
denotation references a symbol. We will need to generalize JointRefDenotation to contain multiple symbols for
a complete fix.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/dotty/tools/dotc/core/Denotations.scala b/src/dotty/tools/dotc/core/Denotations.scala
index 0622829c5..63b94efbd 100644
--- a/src/dotty/tools/dotc/core/Denotations.scala
+++ b/src/dotty/tools/dotc/core/Denotations.scala
@@ -334,7 +334,7 @@ object Denotations {
     final def info(implicit ctx: Context) = infoOrCompleter
     final def validFor = denot1.validFor & denot2.validFor
     final def isType = false
-    def signature(implicit ctx: Context) = multiHasNot("signature")
+    final def signature(implicit ctx: Context) = Signature.OverloadedSignature
     def atSignature(sig: Signature)(implicit ctx: Context): SingleDenotation =
       denot1.atSignature(sig) orElse denot2.atSignature(sig)
     def current(implicit ctx: Context): Denotation =