-- BUILD THE POLYMORPHIC RESULT IDs
; let dict_ids = map instToId dicts
- ; exports <- mapM (mkExport prag_fn tyvars_to_gen (map idType dict_ids))
+ ; exports <- mapM (mkExport top_lvl prag_fn tyvars_to_gen (map idType dict_ids))
mono_bind_infos
; let poly_ids = [poly_id | (_, poly_id, _, _) <- exports]
--------------
-mkExport :: TcPragFun -> [TyVar] -> [TcType] -> MonoBindInfo
- -> TcM ([TyVar], Id, Id, [Prag])
+mkExport :: TopLevelFlag -> TcPragFun -> [TyVar] -> [TcType]
+ -> MonoBindInfo
+ -> TcM ([TyVar], Id, Id, [LPrag])
-- mkExport generates exports with
-- zonked type variables,
-- zonked poly_ids
-- Pre-condition: the inferred_tvs are already zonked
-mkExport prag_fn inferred_tvs dict_tys (poly_name, mb_sig, mono_id)
- = do { (tvs, poly_id) <- mk_poly_id mb_sig
+mkExport top_lvl prag_fn inferred_tvs dict_tys (poly_name, mb_sig, mono_id)
+ = do { warn_missing_sigs <- doptM Opt_WarnMissingSigs
+ ; let warn = isTopLevel top_lvl && warn_missing_sigs
+ ; (tvs, poly_id) <- mk_poly_id warn mb_sig
; poly_id' <- zonkId poly_id
; prags <- tcPrags poly_id' (prag_fn poly_name)
where
poly_ty = mkForAllTys inferred_tvs (mkFunTys dict_tys (idType mono_id))
- mk_poly_id Nothing = return (inferred_tvs, mkLocalId poly_name poly_ty)
- mk_poly_id (Just sig) = do { tvs <- mapM zonk_tv (sig_tvs sig)
- ; return (tvs, sig_id sig) }
+ mk_poly_id warn Nothing = do { missingSigWarn warn poly_name poly_ty
+ ; return (inferred_tvs, mkLocalId poly_name poly_ty) }
+ mk_poly_id warn (Just sig) = do { tvs <- mapM zonk_tv (sig_tvs sig)
+ ; return (tvs, sig_id sig) }
zonk_tv tv = do { ty <- zonkTcTyVar tv; return (tcGetTyVar "mkExport" ty) }
env = foldl add emptyNameEnv prs
add env (n,p) = extendNameEnv_Acc (:) singleton env n p
-tcPrags :: Id -> [LSig Name] -> TcM [Prag]
-tcPrags poly_id prags = mapM tc_prag prags
+tcPrags :: Id -> [LSig Name] -> TcM [LPrag]
+tcPrags poly_id prags = mapM (wrapLocM tc_prag) prags
where
- tc_prag (L loc prag) = setSrcSpan loc $
- addErrCtxt (pragSigCtxt prag) $
- tcPrag poly_id prag
+ tc_prag prag = addErrCtxt (pragSigCtxt prag) $
+ tcPrag poly_id prag
pragSigCtxt prag = hang (ptext SLIT("In the pragma")) 2 (ppr prag)
genCtxt binder_names
= ptext SLIT("When generalising the type(s) for") <+> pprBinders binder_names
+
+missingSigWarn False name ty = return ()
+missingSigWarn True name ty
+ = do { env0 <- tcInitTidyEnv
+ ; let (env1, tidy_ty) = tidyOpenType env0 ty
+ ; addWarnTcM (env1, mk_msg tidy_ty) }
+ where
+ mk_msg ty = vcat [ptext SLIT("Definition but no type signature for") <+> quotes (ppr name),
+ sep [ptext SLIT("Inferred type:") <+> ppr name <+> dcolon <+> ppr ty]]
\end{code}