1 files changed, 30 insertions, 0 deletions
diff --git a/testsuite/tests/plugins/hooks-plugin/Hooks/PhasePlugin.hs b/testsuite/tests/plugins/hooks-plugin/Hooks/PhasePlugin.hs
new file mode 100644
index 0000000000..51cff77404
--- /dev/null
+++ b/testsuite/tests/plugins/hooks-plugin/Hooks/PhasePlugin.hs
@@ -0,0 +1,30 @@
+{-# LANGUAGE GADTs #-}
+{-# OPTIONS_GHC -Wall #-}
+module Hooks.PhasePlugin (plugin) where
+
+import GHC.Plugins
+import GHC.Driver.Hooks
+import GHC.Tc.Utils.Monad
+import GHC.Driver.Pipeline.Execute
+import GHC.Driver.Pipeline.Phases
+import System.IO
+
+plugin :: Plugin
+plugin = defaultPlugin { driverPlugin = hooksP }
+
+hooksP :: [CommandLineOption] -> HscEnv -> IO HscEnv
+hooksP opts hsc_env = do
+  hSetBuffering stdout NoBuffering
+  let hooks  = hsc_hooks hsc_env
+      hooks' = hooks { runPhaseHook = Just fakeRunPhaseHook }
+      hsc_env' = hsc_env { hsc_hooks = hooks' }
+  return hsc_env'
+
+fakeRunPhaseHook :: PhaseHook
+fakeRunPhaseHook = PhaseHook $ \tPhase -> do
+  liftIO $ case tPhase of
+    T_Cpp{} -> putStrLn "Cpp hook fired"
+    T_Hsc{} -> putStrLn "Hsc hook fired"
+    T_FileArgs{} -> putStrLn "FileArgs hook fired"
+    _ -> pure ()
+  runPhase tPhase