X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Frename%2FRnEnv.lhs;h=59451fc535252ad0a2f0ecdd4d7c0f262aab1b1b;hb=11a4f9a91213e98c586feeb64c41c0e07037df66;hp=801dda860c0105a6b243a044689f576b5293c48a;hpb=6c7b41cc2b24f533697a62bf1843507ae043fc97;p=ghc-hetmet.git

diff --git a/compiler/rename/RnEnv.lhs b/compiler/rename/RnEnv.lhs
index 801dda8..59451fc 100644
--- a/compiler/rename/RnEnv.lhs
+++ b/compiler/rename/RnEnv.lhs
@@ -36,7 +36,7 @@ module RnEnv (
 	mapFvRn, mapFvRnCPS,
 	warnUnusedMatches, warnUnusedModules, warnUnusedImports, 
 	warnUnusedTopBinds, warnUnusedLocalBinds,
-	dataTcOccs, unknownNameErr,
+	dataTcOccs, unknownNameErr
     ) where
 
 #include "HsVersions.h"
@@ -55,12 +55,13 @@ import Name		( Name, nameIsLocalOrFrom, mkInternalName, isWiredInName,
 			  nameSrcLoc, nameSrcSpan, nameOccName, nameModule, isExternalName )
 import NameSet
 import NameEnv
-import UniqFM
+import LazyUniqFM
 import DataCon		( dataConFieldLabels )
 import OccName		( OccName, tcName, isDataOcc, pprNonVarNameSpace, occNameSpace,
 			  reportIfUnused, occNameFS )
 import Module		( Module, ModuleName )
-import PrelNames	( mkUnboundName, rOOT_MAIN, iNTERACTIVE, consDataConKey, hasKey )
+import PrelNames	( mkUnboundName, rOOT_MAIN, iNTERACTIVE, 
+			  consDataConKey, hasKey, forall_tv_RDR )
 import UniqSupply
 import BasicTypes	( IPName, mapIPName, Fixity )
 import SrcLoc		( SrcSpan, srcSpanStart, Located(..), eqLocated, unLoc,
@@ -1018,9 +1019,14 @@ shadowedNameWarn doc occ shadowed_locs
     $$ doc
 
 unknownNameErr rdr_name
-  = sep [ptext SLIT("Not in scope:"), 
-	 nest 2 $ pprNonVarNameSpace (occNameSpace (rdrNameOcc rdr_name))
-		  <+> quotes (ppr rdr_name)]
+  = vcat [ hang (ptext SLIT("Not in scope:")) 
+	      2 (pprNonVarNameSpace (occNameSpace (rdrNameOcc rdr_name))
+			  <+> quotes (ppr rdr_name))
+	 , extra ]
+  where
+    extra | rdr_name == forall_tv_RDR 
+	  = ptext SLIT("Perhaps you intended to use -XRankNTypes or similar flag")
+	  | otherwise = empty
 
 unknownSubordinateErr doc op	-- Doc is "method of class" or 
 				-- "field of constructor"