X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcBinds.lhs;h=95f3d4137e097120481e09ad6075714108bd1fce;hb=e68a891932d615590d9b1ab5752ada8142db5053;hp=24f98d86e0bdbd711b34a3c0fa6ed5c0e6fd5c38;hpb=e6d057711f4d6d6ff6342c39fa2b9e44d25447f1;p=ghc-hetmet.git diff --git a/compiler/typecheck/TcBinds.lhs b/compiler/typecheck/TcBinds.lhs index 24f98d8..95f3d41 100644 --- a/compiler/typecheck/TcBinds.lhs +++ b/compiler/typecheck/TcBinds.lhs @@ -1,4 +1,5 @@ % +% (c) The University of Glasgow 2006 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % \section[TcBinds]{TcBinds} @@ -15,57 +16,36 @@ module TcBinds ( tcLocalBinds, tcTopBinds, import {-# SOURCE #-} TcMatches ( tcGRHSsPat, tcMatchesFun ) import {-# SOURCE #-} TcExpr ( tcMonoExpr ) -import DynFlags ( dopt, DynFlags, - DynFlag(Opt_MonomorphismRestriction, Opt_MonoPatBinds, Opt_GlasgowExts) ) -import HsSyn ( HsExpr(..), HsBind(..), LHsBinds, LHsBind, Sig(..), - HsLocalBinds(..), HsValBinds(..), HsIPBinds(..), - LSig, Match(..), IPBind(..), Prag(..), - HsType(..), LHsType, HsExplicitForAll(..), hsLTyVarNames, - isVanillaLSig, sigName, placeHolderNames, isPragLSig, - LPat, GRHSs, MatchGroup(..), pprLHsBinds, mkHsWrap, - collectHsBindBinders, collectPatBinders, pprPatBind, isBangHsBind - ) -import TcHsSyn ( zonkId ) +import DynFlags +import HsSyn +import TcHsSyn import TcRnMonad -import Inst ( newDictBndrs, newIPDict, instToId ) -import TcEnv ( tcExtendIdEnv, tcExtendIdEnv2, tcExtendTyVarEnv2, - pprBinders, tcLookupId, - tcGetGlobalTyVars ) -import TcUnify ( tcInfer, tcSubExp, unifyTheta, - bleatEscapedTvs, sigCtxt ) -import TcSimplify ( tcSimplifyInfer, tcSimplifyInferCheck, - tcSimplifyRestricted, tcSimplifyIPs ) -import TcHsType ( tcHsSigType, UserTypeCtxt(..) ) -import TcPat ( tcLetPat ) -import TcSimplify ( bindInstsOfLocalFuns ) -import TcMType ( newFlexiTyVarTy, zonkQuantifiedTyVar, zonkSigTyVar, - tcInstSigTyVars, tcInstSkolTyVars, tcInstType, - zonkTcType, zonkTcTypes, zonkTcTyVar ) -import TcType ( TcType, TcTyVar, TcThetaType, - SkolemInfo(SigSkol), UserTypeCtxt(FunSigCtxt), - TcTauType, TcSigmaType, isUnboxedTupleType, - mkTyVarTy, mkForAllTys, mkFunTys, exactTyVarsOfType, - mkForAllTy, isUnLiftedType, tcGetTyVar, - mkTyVarTys, tidyOpenTyVar ) -import {- Kind parts of -} Type ( argTypeKind ) -import VarEnv ( TyVarEnv, emptyVarEnv, lookupVarEnv, extendVarEnv ) -import TysPrim ( alphaTyVar ) -import Id ( Id, mkLocalId, mkVanillaGlobal ) -import IdInfo ( vanillaIdInfo ) -import Var ( TyVar, idType, idName ) -import Name ( Name ) +import Inst +import TcEnv +import TcUnify +import TcSimplify +import TcHsType +import TcPat +import TcMType +import TcType +import {- Kind parts of -} Type +import VarEnv +import TysPrim +import Id +import IdInfo +import Var ( TyVar ) +import Name import NameSet import NameEnv import VarSet -import SrcLoc ( Located(..), unLoc, getLoc ) +import SrcLoc import Bag -import ErrUtils ( Message ) -import Digraph ( SCC(..), stronglyConnComp ) -import Maybes ( expectJust, isJust, isNothing, orElse ) -import Util ( singleton ) -import BasicTypes ( TopLevelFlag(..), isTopLevel, isNotTopLevel, - RecFlag(..), isNonRec, InlineSpec, defaultInlineSpec ) +import ErrUtils +import Digraph +import Maybes +import Util +import BasicTypes import Outputable \end{code} @@ -546,7 +526,7 @@ tcMonoBinds [L b_loc (FunBind { fun_id = L nm_loc name, fun_infix = inf, ; let mono_id = mkLocalId mono_name zonked_rhs_ty ; return (unitBag (L b_loc (FunBind { fun_id = L nm_loc mono_id, fun_infix = inf, fun_matches = matches', bind_fvs = fvs, - fun_co_fn = co_fn })), + fun_co_fn = co_fn, fun_tick = Nothing })), [(name, Nothing, mono_id)]) } tcMonoBinds [L b_loc (FunBind { fun_id = L nm_loc name, fun_infix = inf, @@ -570,7 +550,8 @@ tcMonoBinds [L b_loc (FunBind { fun_id = L nm_loc name, fun_infix = inf, ; let fun_bind' = FunBind { fun_id = L nm_loc mono_id, fun_infix = inf, fun_matches = matches', - bind_fvs = placeHolderNames, fun_co_fn = co_fn } + bind_fvs = placeHolderNames, fun_co_fn = co_fn, + fun_tick = Nothing } ; return (unitBag (L b_loc fun_bind'), [(name, Just tc_sig, mono_id)]) } @@ -675,7 +656,8 @@ tcRhs (TcFunBind info fun'@(L _ mono_id) inf matches) = do { (co_fn, matches') <- tcMatchesFun (idName mono_id) matches (idType mono_id) ; return (FunBind { fun_id = fun', fun_infix = inf, fun_matches = matches', - bind_fvs = placeHolderNames, fun_co_fn = co_fn }) } + bind_fvs = placeHolderNames, fun_co_fn = co_fn, + fun_tick = Nothing }) } tcRhs bind@(TcPatBind _ pat' grhss pat_ty) = do { grhss' <- addErrCtxt (patMonoBindsCtxt pat' grhss) $ @@ -728,16 +710,17 @@ generalise dflags top_lvl bind_list sig_fn mono_infos lie_req = tcSimplifyInfer doc tau_tvs lie_req | otherwise -- UNRESTRICTED CASE, WITH TYPE SIGS - = do { sig_lie <- unifyCtxts sigs -- sigs is non-empty + = do { sig_lie <- unifyCtxts sigs -- sigs is non-empty; sig_lie is zonked ; let -- The "sig_avails" is the stuff available. We get that from -- the context of the type signature, BUT ALSO the lie_avail -- so that polymorphic recursion works right (see Note [Polymorphic recursion]) local_meths = [mkMethInst sig mono_id | (_, Just sig, mono_id) <- mono_infos] sig_avails = sig_lie ++ local_meths + loc = sig_loc (head sigs) -- Check that the needed dicts can be -- expressed in terms of the signature ones - ; (forall_tvs, dict_binds) <- tcSimplifyInferCheck doc tau_tvs sig_avails lie_req + ; (forall_tvs, dict_binds) <- tcSimplifyInferCheck loc tau_tvs sig_avails lie_req -- Check that signature type variables are OK ; final_qtvs <- checkSigsTyVars forall_tvs sigs @@ -754,7 +737,8 @@ generalise dflags top_lvl bind_list sig_fn mono_infos lie_req mkMethInst (TcSigInfo { sig_id = poly_id, sig_tvs = tvs, sig_theta = theta, sig_loc = loc }) mono_id - = Method mono_id poly_id (mkTyVarTys tvs) theta loc + = Method {tci_id = mono_id, tci_oid = poly_id, tci_tys = mkTyVarTys tvs, + tci_theta = theta, tci_loc = loc} \end{code} unifyCtxts checks that all the signature contexts are the same @@ -771,14 +755,16 @@ might not otherwise be related. This is a rather subtle issue. \begin{code} unifyCtxts :: [TcSigInfo] -> TcM [Inst] +-- Post-condition: the returned Insts are full zonked unifyCtxts (sig1 : sigs) -- Argument is always non-empty = do { mapM unify_ctxt sigs - ; newDictBndrs (sig_loc sig1) (sig_theta sig1) } + ; theta <- zonkTcThetaType (sig_theta sig1) + ; newDictBndrs (sig_loc sig1) theta } where theta1 = sig_theta sig1 unify_ctxt :: TcSigInfo -> TcM () unify_ctxt sig@(TcSigInfo { sig_theta = theta }) - = setSrcSpan (instLocSrcSpan (sig_loc sig)) $ + = setSrcSpan (instLocSpan (sig_loc sig)) $ addErrCtxt (sigContextsCtxt sig1 sig) $ unifyTheta theta1 theta @@ -841,7 +827,7 @@ checkDistinctTyVars sig_tvs <+> quotes (ppr tidy_tv2) ; failWithTcM (env2, msg) } where -\end{code} +\end{code} @getTyVarsToGen@ decides what type variables to generalise over. @@ -973,13 +959,12 @@ mkTcSigFun :: [LSig Name] -> TcSigFun -- Precondition: no duplicates mkTcSigFun sigs = lookupNameEnv env where - env = mkNameEnv [(name, scoped_tyvars hs_ty) - | L span (TypeSig (L _ name) (L _ hs_ty)) <- sigs] - scoped_tyvars (HsForAllTy Explicit tvs _ _) = hsLTyVarNames tvs - scoped_tyvars other = [] + env = mkNameEnv [(name, hsExplicitTvs lhs_ty) + | L span (TypeSig (L _ name) lhs_ty) <- sigs] -- The scoped names are the ones explicitly mentioned -- in the HsForAll. (There may be more in sigma_ty, because -- of nested type synonyms. See Note [Scoped] with TcSigInfo.) + -- See Note [Only scoped tyvars are in the TyVarEnv] --------------- data TcSigInfo @@ -998,6 +983,19 @@ data TcSigInfo sig_loc :: InstLoc -- The location of the signature } + +-- Note [Only scoped tyvars are in the TyVarEnv] +-- We are careful to keep only the *lexically scoped* type variables in +-- the type environment. Why? After all, the renamer has ensured +-- that only legal occurrences occur, so we could put all type variables +-- into the type env. +-- +-- But we want to check that two distinct lexically scoped type variables +-- do not map to the same internal type variable. So we need to know which +-- the lexically-scoped ones are... and at the moment we do that by putting +-- only the lexically scoped ones into the environment. + + -- Note [Scoped] -- There may be more instantiated type variables than scoped -- ones. For example: @@ -1010,7 +1008,7 @@ data TcSigInfo -- and remember the names from the original HsForAllTy in sig_scoped -- Note [Instantiate sig] --- It's vital to instantiate a type signature with fresh variable. +-- It's vital to instantiate a type signature with fresh variables. -- For example: -- type S = forall a. a->a -- f,g :: S @@ -1046,7 +1044,7 @@ tcInstSig :: Bool -> Name -> [Name] -> TcM TcSigInfo -- Instantiate the signature, with either skolems or meta-type variables -- depending on the use_skols boolean. This variable is set True -- when we are typechecking a single function binding; and False for --- pattern bindigs and a group of several function bindings. +-- pattern bindings and a group of several function bindings. -- Reason: in the latter cases, the "skolems" can be unified together, -- so they aren't properly rigid in the type-refinement sense. -- NB: unless we are doing H98, each function with a sig will be done @@ -1065,8 +1063,7 @@ tcInstSig use_skols name scoped_names = do { poly_id <- tcLookupId name -- Cannot fail; the poly ids are put into -- scope when starting the binding group ; let skol_info = SigSkol (FunSigCtxt name) - inst_tyvars | use_skols = tcInstSkolTyVars skol_info - | otherwise = tcInstSigTyVars skol_info + inst_tyvars = tcInstSigTyVars use_skols skol_info ; (tvs, theta, tau) <- tcInstType inst_tyvars (idType poly_id) ; loc <- getInstLoc (SigOrigin skol_info) ; return (TcSigInfo { sig_id = poly_id,