Add TcRnMonad.unlessXOptM

This usefully joins whenXOptM; there are probably lots of places
we should use it!

This patch does not use new new function at all; but it's preparing
for an upcoming patch when I do use it.

1 files changed, 6 insertions, 1 deletions

diff --git a/compiler/typecheck/TcRnMonad.hs b/compiler/typecheck/TcRnMonad.hs
index a6a995de1a..b9638edb1f 100644
--- a/compiler/typecheck/TcRnMonad.hs
+++ b/compiler/typecheck/TcRnMonad.hs
@@ -19,7 +19,8 @@ module TcRnMonad(
   getEnvs, setEnvs,
   xoptM, doptM, goptM, woptM,
   setXOptM, unsetXOptM, unsetGOptM, unsetWOptM,
-  whenDOptM, whenGOptM, whenWOptM, whenXOptM,
+  whenDOptM, whenGOptM, whenWOptM,
+  whenXOptM, unlessXOptM,
   getGhcMode,
   withDoDynamicToo,
   getEpsVar,
@@ -499,6 +500,10 @@ whenXOptM :: LangExt.Extension -> TcRnIf gbl lcl () -> TcRnIf gbl lcl ()
 whenXOptM flag thing_inside = do b <- xoptM flag
                                  when b thing_inside
 
+unlessXOptM :: LangExt.Extension -> TcRnIf gbl lcl () -> TcRnIf gbl lcl ()
+unlessXOptM flag thing_inside = do b <- xoptM flag
+                                   unless b thing_inside
+
 getGhcMode :: TcRnIf gbl lcl GhcMode
 getGhcMode = do { env <- getTopEnv; return (ghcMode (hsc_dflags env)) }