Avoid failing with macros in the community build

Author: nicolasstucki

community-build/community-projects/ScalaPB

@@ -77,6 +77,7 @@ class ScalaSettings extends Settings.SettingGroup {
   val XreplLineWidth: Setting[Int] = IntSetting("-Xrepl-line-width", "Maximal number of columns per line for REPL output", 390)
   val XfatalWarnings: Setting[Boolean] = BooleanSetting("-Xfatal-warnings", "Fail the compilation if there are any warnings.")
   val XverifySignatures: Setting[Boolean] = BooleanSetting("-Xverify-signatures", "Verify generic signatures in generated bytecode.")
+  val XignoreScala2Macros: Setting[Boolean] = BooleanSetting("-Xignore-scala2-macros", "Ignore errors when compiling code that calls Scala2 macros, these will fail at runtime.")
 
   val XmixinForceForwarders = ChoiceSetting(
     name    = "-Xmixin-force-forwarders",

community-build/community-projects/scalatest

@@ -2754,7 +2754,10 @@ class Typer extends Namer
         readaptSimplified(Inliner.inlineCall(tree, pt))
       }
       else if (tree.symbol.is(Macro, butNot = Inline)) {
-        if (tree.symbol eq defn.StringContext_f) {
+        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
+        } else if (tree.symbol eq defn.StringContext_f) {
           val Apply(TypeApply(Select(sc, _), _), args) = tree
           val newCall = ref(defn.InternalStringContextModule_f).appliedTo(sc).appliedToArgs(args)
           Inliner.inlineCall(newCall, pt)