1 files changed, 26 insertions, 0 deletions
diff --git a/testsuite/tests/driver/T4437.hs b/testsuite/tests/driver/T4437.hs
new file mode 100644
index 0000000000..64634a9c74
--- /dev/null
+++ b/testsuite/tests/driver/T4437.hs
@@ -0,0 +1,26 @@
+
+module Main (main) where
+
+import Data.List
+import DynFlags
+import Language.Haskell.Extension
+
+main :: IO ()
+main = do let ghcExtensions = [ ext | (ext, _, _, _) <- xFlags ]
+              cabalExtensions = map show [ toEnum 0 :: KnownExtension .. ]
+              ghcOnlyExtensions = ghcExtensions \\ cabalExtensions
+              -- These are extensions which are deliberately not yet
+              -- registered with Cabal
+              expectedGhcOnlyExtensions
+                  = ["ParallelArrays",
+                     "RelaxedLayout",
+                     "DeriveGeneric",
+                     "DefaultSignatures",
+                     "InterruptibleFFI",
+                     "AlternativeLayoutRule",
+                     "AlternativeLayoutRuleTransitional",
+                     "MonadComprehensions"]
+              unexpectedGhcOnlyExtension = ghcOnlyExtensions
+                                        \\ expectedGhcOnlyExtensions
+          mapM_ putStrLn unexpectedGhcOnlyExtension
+