1 files changed, 4 insertions, 2 deletions
diff --git a/test/junit/scala/tools/nsc/backend/jvm/CodeGenTools.scala b/test/junit/scala/tools/nsc/backend/jvm/CodeGenTools.scala
index 342f403426..0d353e930e 100644
--- a/test/junit/scala/tools/nsc/backend/jvm/CodeGenTools.scala
+++ b/test/junit/scala/tools/nsc/backend/jvm/CodeGenTools.scala
@@ -50,9 +50,11 @@ object CodeGenTools {
   }
 
   def newCompilerWithoutVirtualOutdir(defaultArgs: String = "-usejavacp", extraArgs: String = ""): Global = {
-    val settings = new Settings()
+    def showError(s: String) = throw new Exception(s)
+    val settings = new Settings(showError)
     val args = (CommandLineParser tokenize defaultArgs) ++ (CommandLineParser tokenize extraArgs)
-    settings.processArguments(args, processAll = true)
+    val (_, nonSettingsArgs) = settings.processArguments(args, processAll = true)
+    if (nonSettingsArgs.nonEmpty) showError("invalid compiler flags: " + nonSettingsArgs.mkString(" "))
     new Global(settings, new StoreReporter)
   }