Fix TH erorr recovery (test is TH_recover)

diff --git a/compiler/typecheck/TcSplice.lhs b/compiler/typecheck/TcSplice.lhs
index 2215c9b..7c3aa86 100644 (file)
--- a/compiler/typecheck/TcSplice.lhs
+++ b/compiler/typecheck/TcSplice.lhs
@@ -421,7 +421,16 @@ instance TH.Quasi (IOEnv (Env TcGblEnv TcLclEnv)) where
 
   qCurrentModule = do { m <- getModule; return (moduleString m) }
   qReify v = reify v
-  qRecover = recoverM
+
+       -- For qRecover, discard error messages if 
+       -- the recovery action is chosen.  Otherwise
+       -- we'll only fail higher up.  c.f. tryTcLIE_
+  qRecover recover main = do { (msgs, mb_res) <- tryTcErrs main
+                            ; case mb_res of
+                                Just val -> do { addMessages msgs      -- There might be warnings
+                                               ; return val }
+                                Nothing  -> recover                    -- Discard all msgs
+                         }
 
   qRunIO io = ioToTcRn io
 \end{code}