Robustify the treatement of DFunUnfolding

[ghc-hetmet.git] / compiler / deSugar / DsBinds.lhs

diff --git a/compiler/deSugar/DsBinds.lhs b/compiler/deSugar/DsBinds.lhs
index bfe4323..2c6f361 100644 (file)
--- a/compiler/deSugar/DsBinds.lhs
+++ b/compiler/deSugar/DsBinds.lhs
@@ -462,6 +462,7 @@ dsSpecs poly_id poly_rhs prags
           ; spec_name <- newLocalName poly_name
           ; wrap_fn   <- dsCoercion spec_co
            ; let ds_spec_expr = wrap_fn (Var poly_id)
+                 spec_ty = exprType ds_spec_expr
           ; case decomposeRuleLhs ds_spec_expr of {
               Nothing -> do { warnDs (decomp_msg spec_co)
                              ; return Nothing } ;
@@ -473,10 +474,9 @@ dsSpecs poly_id poly_rhs prags
                bs | not (null bs) -> do { warnDs (dead_msg bs); return Nothing } 
                   | otherwise -> do
 
-          { (spec_unf, unf_pairs) <- specUnfolding wrap_fn (realIdUnfolding poly_id)
+          { (spec_unf, unf_pairs) <- specUnfolding wrap_fn spec_ty (realIdUnfolding poly_id)
 
-          ; let spec_ty = exprType ds_spec_expr
-                spec_id  = mkLocalId spec_name spec_ty 
+          ; let spec_id  = mkLocalId spec_name spec_ty 
                            `setInlinePragma` inl_prag
                            `setIdUnfolding`  spec_unf
                 inl_prag | isDefaultInlinePragma spec_inl = idInlinePragma poly_id
@@ -511,12 +511,13 @@ dsSpecs poly_id poly_rhs prags
             2 (pprHsWrapper (ppr poly_id) spec_co)
             
 
-specUnfolding :: (CoreExpr -> CoreExpr) -> Unfolding -> DsM (Unfolding, [(Id,CoreExpr)])
-specUnfolding wrap_fn (DFunUnfolding con ops)
+specUnfolding :: (CoreExpr -> CoreExpr) -> Type 
+              -> Unfolding -> DsM (Unfolding, [(Id,CoreExpr)])
+specUnfolding wrap_fn spec_ty (DFunUnfolding _ _ ops)
   = do { let spec_rhss = map wrap_fn ops
        ; spec_ids <- mapM (mkSysLocalM (fsLit "spec") . exprType) spec_rhss
-       ; return (DFunUnfolding con (map Var spec_ids), spec_ids `zip` spec_rhss) }
-specUnfolding _ _
+       ; return (mkDFunUnfolding spec_ty (map Var spec_ids), spec_ids `zip` spec_rhss) }
+specUnfolding _ _ _
   = return (noUnfolding, [])
 
 mkArbitraryTypeEnv :: [TyVar] -> [([TyVar], a, b, c)] -> TyVarEnv Type