X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcBinds.lhs;h=671bfeac4c742376fa6d7ad0c3dd4418b926b259;hb=421819753b3eb4940a26e578ef0e4c5cd31761fa;hp=5d9dbb885a0a38badb0312aa31ba3bdf0e345234;hpb=e5ca7e6e5137a2e6081717e5e90ca52a30840f68;p=ghc-hetmet.git diff --git a/compiler/typecheck/TcBinds.lhs b/compiler/typecheck/TcBinds.lhs index 5d9dbb8..671bfea 100644 --- a/compiler/typecheck/TcBinds.lhs +++ b/compiler/typecheck/TcBinds.lhs @@ -5,6 +5,13 @@ \section[TcBinds]{TcBinds} \begin{code} +{-# OPTIONS -w #-} +-- The above warning supression flag is a temporary kludge. +-- While working on this module you are encouraged to remove it and fix +-- any warnings in the module. See +-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings +-- for details + module TcBinds ( tcLocalBinds, tcTopBinds, tcHsBootSigs, tcMonoBinds, TcPragFun, tcSpecPrag, tcPrags, mkPragFun, @@ -30,6 +37,7 @@ import TcPat import TcMType import TcType import {- Kind parts of -} Type +import Coercion import VarEnv import TysPrim import Id @@ -162,9 +170,9 @@ tcValBinds top_lvl (ValBindsOut binds sigs) thing_inside -- Extend the envt right away with all -- the Ids declared with type signatures - ; gla_exts <- doptM Opt_GlasgowExts + ; poly_rec <- doptM Opt_RelaxedPolyRec ; (binds', thing) <- tcExtendIdEnv poly_ids $ - tc_val_binds gla_exts top_lvl sig_fn prag_fn + tc_val_binds poly_rec top_lvl sig_fn prag_fn binds thing_inside ; return (ValBindsOut binds' sigs, thing) } @@ -176,14 +184,14 @@ tc_val_binds :: Bool -> TopLevelFlag -> TcSigFun -> TcPragFun -- Typecheck a whole lot of value bindings, -- one strongly-connected component at a time -tc_val_binds gla_exts top_lvl sig_fn prag_fn [] thing_inside +tc_val_binds poly_rec top_lvl sig_fn prag_fn [] thing_inside = do { thing <- thing_inside ; return ([], thing) } -tc_val_binds gla_exts top_lvl sig_fn prag_fn (group : groups) thing_inside +tc_val_binds poly_rec top_lvl sig_fn prag_fn (group : groups) thing_inside = do { (group', (groups', thing)) - <- tc_group gla_exts top_lvl sig_fn prag_fn group $ - tc_val_binds gla_exts top_lvl sig_fn prag_fn groups thing_inside + <- tc_group poly_rec top_lvl sig_fn prag_fn group $ + tc_val_binds poly_rec top_lvl sig_fn prag_fn groups thing_inside ; return (group' ++ groups', thing) } ------------------------ @@ -195,15 +203,15 @@ tc_group :: Bool -> TopLevelFlag -> TcSigFun -> TcPragFun -- We get a list of groups back, because there may -- be specialisations etc as well -tc_group gla_exts top_lvl sig_fn prag_fn (NonRecursive, binds) thing_inside +tc_group poly_rec top_lvl sig_fn prag_fn (NonRecursive, binds) thing_inside -- A single non-recursive binding -- We want to keep non-recursive things non-recursive -- so that we desugar unlifted bindings correctly = do { (binds, thing) <- tc_haskell98 top_lvl sig_fn prag_fn NonRecursive binds thing_inside ; return ([(NonRecursive, b) | b <- binds], thing) } -tc_group gla_exts top_lvl sig_fn prag_fn (Recursive, binds) thing_inside - | not gla_exts -- Recursive group, normal Haskell 98 route +tc_group poly_rec top_lvl sig_fn prag_fn (Recursive, binds) thing_inside + | not poly_rec -- Recursive group, normal Haskell 98 route = do { (binds1, thing) <- tc_haskell98 top_lvl sig_fn prag_fn Recursive binds thing_inside ; return ([(Recursive, unionManyBags binds1)], thing) } @@ -241,7 +249,7 @@ tc_haskell98 top_lvl sig_fn prag_fn rec_flag binds thing_inside bindLocalInsts :: TopLevelFlag -> TcM ([LHsBinds TcId], [TcId], a) -> TcM ([LHsBinds TcId], a) bindLocalInsts top_lvl thing_inside | isTopLevel top_lvl = do { (binds, ids, thing) <- thing_inside; return (binds, thing) } - -- For the top level don't bother will all this bindInstsOfLocalFuns stuff. + -- For the top level don't bother with all this bindInstsOfLocalFuns stuff. -- All the top level things are rec'd together anyway, so it's fine to -- leave them to the tcSimplifyTop, and quite a bit faster too @@ -337,7 +345,7 @@ tcPolyBinds top_lvl sig_fn prag_fn rec_group rec_tc binds -- 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] @@ -352,7 +360,8 @@ tcPolyBinds top_lvl sig_fn prag_fn rec_group rec_tc binds -------------- -mkExport :: TcPragFun -> [TyVar] -> [TcType] -> MonoBindInfo +mkExport :: TopLevelFlag -> TcPragFun -> [TyVar] -> [TcType] + -> MonoBindInfo -> TcM ([TyVar], Id, Id, [LPrag]) -- mkExport generates exports with -- zonked type variables, @@ -365,8 +374,10 @@ mkExport :: TcPragFun -> [TyVar] -> [TcType] -> MonoBindInfo -- 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) @@ -376,9 +387,10 @@ mkExport prag_fn inferred_tvs dict_tys (poly_name, mb_sig, mono_id) 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) } @@ -507,7 +519,7 @@ tcMonoBinds [L b_loc (FunBind { fun_id = L nm_loc name, fun_infix = inf, -- e.g. f = \(x::forall a. a->a) -> -- We want to infer a higher-rank type for f setSrcSpan b_loc $ - do { ((co_fn, matches'), rhs_ty) <- tcInfer (tcMatchesFun name matches) + do { ((co_fn, matches'), rhs_ty) <- tcInfer (tcMatchesFun name inf matches) -- Check for an unboxed tuple type -- f = (# True, False #) @@ -542,7 +554,7 @@ tcMonoBinds [L b_loc (FunBind { fun_id = L nm_loc name, fun_infix = inf, | (name, tv) <- sig_scoped tc_sig `zip` sig_tvs tc_sig ] ; (co_fn, matches') <- tcExtendTyVarEnv2 rhs_tvs $ - tcMatchesFun mono_name matches mono_ty + tcMatchesFun mono_name inf matches mono_ty ; let fun_bind' = FunBind { fun_id = L nm_loc mono_id, fun_infix = inf, fun_matches = matches', @@ -649,8 +661,8 @@ tcLhs sig_fn other_bind = pprPanic "tcLhs" (ppr other_bind) ------------------- tcRhs :: TcMonoBind -> TcM (HsBind TcId) tcRhs (TcFunBind info fun'@(L _ mono_id) inf matches) - = do { (co_fn, matches') <- tcMatchesFun (idName mono_id) matches - (idType mono_id) + = do { (co_fn, matches') <- tcMatchesFun (idName mono_id) inf + matches (idType mono_id) ; return (FunBind { fun_id = fun', fun_infix = inf, fun_matches = matches', bind_fvs = placeHolderNames, fun_co_fn = co_fn, fun_tick = Nothing }) } @@ -765,7 +777,17 @@ unifyCtxts (sig1 : sigs) -- Argument is always non-empty unify_ctxt sig@(TcSigInfo { sig_theta = theta }) = setSrcSpan (instLocSpan (sig_loc sig)) $ addErrCtxt (sigContextsCtxt sig1 sig) $ - unifyTheta theta1 theta + do { cois <- unifyTheta theta1 theta + ; -- Check whether all coercions are identity coercions + -- That can happen if we have, say + -- f :: C [a] => ... + -- g :: C (F a) => ... + -- where F is a type function and (F a ~ [a]) + -- Then unification might succeed with a coercion. But it's much + -- much simpler to require that such signatures have identical contexts + checkTc (all isIdentityCoercion cois) + (ptext SLIT("Mutually dependent functions have syntactically distinct contexts")) + } checkSigsTyVars :: [TcTyVar] -> [TcSigInfo] -> TcM [TcTyVar] checkSigsTyVars qtvs sigs @@ -1144,4 +1166,13 @@ restrictedBindCtxtErr binder_names 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}