Improve error reporting for type signatures

[ghc-hetmet.git] / compiler / rename / RnEnv.lhs

diff --git a/compiler/rename/RnEnv.lhs b/compiler/rename/RnEnv.lhs
index 50b0adb..54a768a 100644 (file)
--- a/compiler/rename/RnEnv.lhs
+++ b/compiler/rename/RnEnv.lhs
@@ -195,8 +195,25 @@ lookupTopBndrRn rdr_name
 -- The Haskell98 report does not stipulate this, but it will!
 -- So we must treat the 'f' in the signature in the same way
 -- as the binding occurrence of 'f', using lookupBndrRn
+--
+-- However, consider this case:
+--     import M( f )
+--     f :: Int -> Int
+--     g x = x
+-- We don't want to say 'f' is out of scope; instead, we want to
+-- return the imported 'f', so that later on the reanamer will
+-- correctly report "misplaced type sig".
 lookupLocatedSigOccRn :: Located RdrName -> RnM (Located Name)
-lookupLocatedSigOccRn = lookupLocatedBndrRn
+lookupLocatedSigOccRn = wrapLocM $ \ rdr_name -> do
+       { local_env <- getLocalRdrEnv
+       ; case lookupLocalRdrEnv local_env rdr_name of {
+               Just n  -> return n ;
+               Nothing -> do
+       { mb_gre <- lookupGreLocalRn rdr_name
+       ; case mb_gre of 
+               Just gre -> return (gre_name gre) 
+               Nothing  -> lookupGlobalOccRn rdr_name
+       }}}
 
 -- lookupInstDeclBndr is used for the binders in an 
 -- instance declaration.   Here we use the class name to