Filter member of refinement, handle Annotated

Author: som-snytt

compiler/src/dotty/tools/dotc/transform/CheckUnused.scala

@@ -222,6 +222,9 @@ class CheckUnused private (phaseMode: CheckUnused.PhaseMode, suffix: String, _ke
         transformAllDeep(hi)
         transformAllDeep(alias)
       case tree: NamedArg => transformAllDeep(tree.arg)
+      case Annotated(arg, annot) =>
+        transformAllDeep(arg)
+        transformAllDeep(annot)
       case _: InferredTypeTree =>
       case _ if tree.isType =>
         //println(s"OTHER TYPE ${tree.getClass} ${tree.show}")
@@ -684,6 +687,7 @@ object CheckUnused:
           && !memDef.symbol.isAllOf(Flags.AccessorCreationFlags)
           && !memDef.name.isWildcard
           && !memDef.symbol.owner.is(ExtensionMethod)
+          && !memDef.symbol.owner.isRefinementClass
 
       private def isValidParam(using Context): Boolean =
         val sym = memDef.symbol

tests/pos/i17631.scala

@@ -1,4 +1,4 @@
-//> using options -Xfatal-warnings -Wunused:all -deprecation -feature
+//> using options -Werror -Wunused:all -deprecation -feature
 
 object foo {
   type Bar

tests/warn/i19657.scala

@@ -83,3 +83,8 @@ class `scope of super`:
       class E(e: Int) extends C(i + k):
         def g = e + y + k + 1
       E(0).g
+
+import scala.annotation.meta.*
+object Alias {
+  type A = Deprecated @param
+}