Fix Scala 2 Macro check

Previously we checked for `Macro | Scala2x` but the `Scala2x` was on its owner

Author: nicolasstucki

compiler/src/dotty/tools/dotc/core/Flags.scala

@@ -661,9 +661,6 @@ object Flags {
   /** Is a default parameter in Scala 2*/
   final val DefaultParameter: FlagConjunction = allOf(Param, DefaultParameterized)
 
-  /** A Scala 2 Macro */
-  final val Scala2Macro: FlagConjunction = allOf(Macro, Scala2x)
-
   /** A trait that does not need to be initialized */
   final val NoInitsTrait: FlagConjunction = allOf(Trait, NoInits)
 

compiler/src/dotty/tools/dotc/core/SymDenotations.scala

@@ -807,6 +807,9 @@ object SymDenotations {
                            // we need an inline flag on them only do that
                            // reduceProjection gets access to their rhs
 
+    /** Is this a Scala 2 macro */
+    final def isScala2Macro(implicit ctx: Context): Boolean = is(Macro) && symbol.owner.is(Scala2x)
+
     /** An erased value or an inline method, excluding @forceInline annotated methods.
      *  The latter have to be kept around to get to parity with Scala.
      *  This is necessary at least until we have full bootstrap. Right now

compiler/src/dotty/tools/dotc/typer/RefChecks.scala

@@ -400,10 +400,10 @@ object RefChecks {
         overrideError("is an extension method, cannot override a normal method")
       } else if (other.is(Extension) && !member.is(Extension)) { // (1.9.2)
         overrideError("is a normal method, cannot override an extension method")
-      } else if ((member.isInlineMethod || member.is(Scala2Macro)) && other.is(Deferred) &&
+      } else if ((member.isInlineMethod || member.isScala2Macro) && other.is(Deferred) &&
                  member.extendedOverriddenSymbols.forall(_.is(Deferred))) { // (1.10)
         overrideError("is an inline method, must override at least one concrete method")
-      } else if (other.is(Scala2Macro) && !member.is(Scala2Macro)) { // (1.11)
+      } else if (other.isScala2Macro && !member.isScala2Macro) { // (1.11)
         overrideError("cannot be used here - only Scala-2 macros can override Scala-2 macros")
       } else if (!compatibleTypes(memberTp(self), otherTp(self)) &&
                  !compatibleTypes(memberTp(upwardsSelf), otherTp(upwardsSelf))) {

compiler/src/dotty/tools/dotc/typer/Typer.scala

@@ -2655,7 +2655,7 @@ class Typer extends Namer
         tree.tpe <:< wildApprox(pt)
         readaptSimplified(Inliner.inlineCall(tree, pt))
       }
-      else if (tree.symbol.is(Macro, butNot = Inline)) {
+      else if (tree.symbol.isScala2Macro) {
         if (ctx.settings.XignoreScala2Macros.value) {
           ctx.warning("Scala 2 macro cannot be used in Dotty. See http://dotty.epfl.ch/docs/reference/dropped-features/macros.html", tree.sourcePos)
           tree

tests/neg/override-scala2-macro.check

@@ -0,0 +1,3 @@
+<56..56> in override-scala2-macro.scala
+error overriding method f in class StringContext of type [A >: Any](args: Seq[A]): String;
+  method f of type [A >: Any](args: Seq[A]): String cannot be used here - only Scala-2 macros can override Scala-2 macros

tests/neg/override-scala2-macro.scala

@@ -0,0 +1,3 @@
+class Foo extends StringContext {
+  override inline def f[A >: Any](args: A*): String = ??? // error
+}