additional class tags for reflection API

Introduces a test that iterates all abstract types in reflection API
and makes sure that every one of them has an associated class tag.

After being introduced, the test has immediately failed exposing
the lack of tags for TreeCopier, Mirror and RuntimeClass, which has been
subsequently fixed in this commit.

1 files changed, 17 insertions, 0 deletions

diff --git a/test/files/run/reflection-tags.scala b/test/files/run/reflection-tags.scala
new file mode 100644
index 0000000000..fba90f61e9
--- /dev/null
+++ b/test/files/run/reflection-tags.scala
@@ -0,0 +1,17 @@
+import scala.reflect.runtime.universe._
+import scala.reflect.ClassTag
+
+object Test extends App {
+  var typeMembers = typeOf[scala.reflect.api.Universe].members.filter(sym => sym.isType && !sym.isClass).toList
+  typeMembers = typeMembers.filter(_.name != TypeName("ModifiersCreator")) // type ModifiersCreator = ModifiersExtractor
+  val tags = typeOf[scala.reflect.api.Universe].members.filter(sym => sym.isImplicit).toList
+
+  typeMembers.foreach(_.typeSignature)
+  tags.foreach(_.typeSignature)
+
+  val outliers = typeMembers.filter(tm => !tags.exists(tag => tag.typeSignature match {
+    case NullaryMethodType(TypeRef(_, sym, targ :: Nil)) => sym == typeOf[ClassTag[_]].typeSymbol && targ.typeSymbol == tm
+    case _ => false
+  }))
+  println(outliers)
+}
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