X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FbasicTypes%2FRdrName.lhs;h=5e184973ff3f084d5e8d30bd630129bb9f723885;hb=abd113f06ebf3ac29f852e80c5a8c0060f979202;hp=acc17f16270a6c560986236fbbba73de03f74052;hpb=a64d06b29c34cccce9e1f4d6260cb94e042e1104;p=ghc-hetmet.git

diff --git a/compiler/basicTypes/RdrName.lhs b/compiler/basicTypes/RdrName.lhs
index acc17f1..5e18497 100644
--- a/compiler/basicTypes/RdrName.lhs
+++ b/compiler/basicTypes/RdrName.lhs
@@ -29,7 +29,7 @@ module RdrName (
 	lookupGlobalRdrEnv, extendGlobalRdrEnv,
 	pprGlobalRdrEnv, globalRdrEnvElts,
 	lookupGRE_RdrName, lookupGRE_Name, getGRE_NameQualifier_maybes,
-        hideSomeUnquals,
+        hideSomeUnquals, findLocalDupsRdrEnv,
 
 	-- GlobalRdrElt, Provenance, ImportSpec
 	GlobalRdrElt(..), isLocalGRE, unQualOK, qualSpecOK, unQualSpecOK,
@@ -463,6 +463,27 @@ mkGlobalRdrEnv gres
 				 (nameOccName (gre_name gre)) 
 				 [gre]
 
+findLocalDupsRdrEnv :: GlobalRdrEnv -> [OccName] -> (GlobalRdrEnv, [[Name]])
+-- For each OccName, see if there are multiple LocalDef definitions
+-- for it.  If so, remove all but one (to suppress subsequent error messages)
+-- and return a list of the duplicate bindings
+findLocalDupsRdrEnv rdr_env occs 
+  = go rdr_env [] occs
+  where
+    go rdr_env dups [] = (rdr_env, dups)
+    go rdr_env dups (occ:occs)
+      = case filter isLocalGRE gres of
+	  []       -> WARN( True, ppr occ <+> ppr rdr_env ) 
+		      go rdr_env dups occs	-- Weird!  No binding for occ
+	  [_]      -> go rdr_env dups occs	-- The common case
+	  dup_gres -> go (extendOccEnv rdr_env occ (head dup_gres : nonlocal_gres))
+   		         (map gre_name dup_gres : dups)
+			 occs
+      where
+        gres = lookupOccEnv rdr_env occ `orElse` []
+	nonlocal_gres = filterOut isLocalGRE gres
+
+
 insertGRE :: GlobalRdrElt -> [GlobalRdrElt] -> [GlobalRdrElt]
 insertGRE new_g [] = [new_g]
 insertGRE new_g (old_g : old_gs)