Look through type synonyms when computing orphans

[ghc-hetmet.git] / compiler / iface / MkIface.lhs

diff --git a/compiler/iface/MkIface.lhs b/compiler/iface/MkIface.lhs
index c0d49a3..b940cb1 100644 (file)
--- a/compiler/iface/MkIface.lhs
+++ b/compiler/iface/MkIface.lhs
@@ -1431,7 +1431,7 @@ instanceToIfaceInst (Instance { is_dfun = dfun_id, is_flag = oflag,
     (_, _, cls, tys) = tcSplitDFunTy (idType dfun_id)
                -- Slightly awkward: we need the Class to get the fundeps
     (tvs, fds) = classTvsFds cls
-    arg_names = [filterNameSet is_local (tyClsNamesOfType ty) | ty <- tys]
+    arg_names = [filterNameSet is_local (orphNamesOfType ty) | ty <- tys]
     orph | is_local cls_name = Just (nameOccName cls_name)
         | all isJust mb_ns  = ASSERT( not (null mb_ns) ) head mb_ns
         | otherwise         = Nothing
@@ -1549,10 +1549,10 @@ coreRuleToIfaceRule _ (BuiltinRule { ru_fn = fn})
   = pprTrace "toHsRule: builtin" (ppr fn) $
     bogusIfaceRule fn
 
-coreRuleToIfaceRule mod (Rule { ru_name = name, ru_fn = fn, 
-                                ru_act = act, ru_bndrs = bndrs,
-                               ru_args = args, ru_rhs = rhs, 
-                                ru_auto = auto })
+coreRuleToIfaceRule mod rule@(Rule { ru_name = name, ru_fn = fn, 
+                                     ru_act = act, ru_bndrs = bndrs,
+                                    ru_args = args, ru_rhs = rhs, 
+                                     ru_auto = auto })
   = IfaceRule { ifRuleName  = name, ifActivation = act, 
                ifRuleBndrs = map toIfaceBndr bndrs,
                ifRuleHead  = fn, 
@@ -1571,9 +1571,7 @@ coreRuleToIfaceRule mod (Rule { ru_name = name, ru_fn = fn,
        -- Compute orphanhood.  See Note [Orphans] in IfaceSyn
        -- A rule is an orphan only if none of the variables
        -- mentioned on its left-hand side are locally defined
-    lhs_names = fn : nameSetToList (exprsFreeNames args)
-               -- No need to delete bndrs, because
-               -- exprsFreeNames finds only External names
+    lhs_names = nameSetToList (ruleLhsOrphNames rule)
 
     orph = case filter (nameIsLocalOrFrom mod) lhs_names of
                        (n : _) -> Just (nameOccName n)