X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcExpr.lhs;h=cb57efdc2868e993e3f00978abc040d958eca901;hb=d75105426df54cf78cf5827ed307a64b51a0f428;hp=59730b2d94e5aa06c8b48063827d70cc0001d498;hpb=5e6242927839c8ddc73a55eb7828c0b7e4cc3ab2;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcExpr.lhs b/ghc/compiler/typecheck/TcExpr.lhs index 59730b2..cb57efd 100644 --- a/ghc/compiler/typecheck/TcExpr.lhs +++ b/ghc/compiler/typecheck/TcExpr.lhs @@ -9,61 +9,58 @@ module TcExpr ( tcApp, tcExpr, tcMonoExpr, tcPolyExpr, tcId ) where #include "HsVersions.h" import HsSyn ( HsExpr(..), HsLit(..), ArithSeqInfo(..), - StmtCtxt(..), mkMonoBind + HsMatchContext(..), HsDoContext(..), mkMonoBind ) import RnHsSyn ( RenamedHsExpr, RenamedRecordBinds ) import TcHsSyn ( TcExpr, TcRecordBinds, mkHsLet ) import TcMonad -import BasicTypes ( RecFlag(..) ) - +import BasicTypes ( RecFlag(..), isMarkedStrict ) import Inst ( InstOrigin(..), LIE, mkLIE, emptyLIE, unitLIE, plusLIE, plusLIEs, newOverloadedLit, newMethod, newIPDict, - newDicts, newClassDicts, + newDicts, instToId, tcInstId ) import TcBinds ( tcBindsAndThen ) -import TcEnv ( TcTyThing(..), - tcLookupClass, tcLookupGlobalId, tcLookupGlobal_maybe, - tcLookupTyCon, tcLookupDataCon, tcLookup, - tcExtendGlobalTyVars, tcLookupSyntaxName +import TcEnv ( tcLookupClass, tcLookupGlobalId, tcLookupGlobal_maybe, + tcLookupTyCon, tcLookupDataCon, tcLookupId, + tcExtendGlobalTyVars ) import TcMatches ( tcMatchesCase, tcMatchLambda, tcStmts ) -import TcMonoType ( tcHsSigType, checkSigTyVars, sigCtxt ) +import TcMonoType ( tcHsSigType, UserTypeCtxt(..), checkSigTyVars, sigCtxt ) import TcPat ( badFieldCon, simpleHsLitTy ) import TcSimplify ( tcSimplifyCheck, tcSimplifyIPs ) -import TcType ( TcType, TcTauType, - tcInstTyVars, tcInstType, - newTyVarTy, newTyVarTys, zonkTcType ) - -import FieldLabel ( fieldLabelName, fieldLabelType, fieldLabelTyCon ) -import Id ( idType, recordSelectorFieldLabel, isRecordSelector ) -import DataCon ( dataConFieldLabels, dataConSig, - dataConStrictMarks, StrictnessMark(..) +import TcMType ( tcInstTyVars, tcInstType, + newTyVarTy, newTyVarTys, zonkTcType, + unifyTauTy, unifyFunTy, unifyListTy, unifyTupleTy ) -import Name ( Name ) -import Type ( mkFunTy, mkAppTy, mkTyConTy, - splitFunTy_maybe, splitFunTys, - mkTyConApp, splitSigmaTy, +import TcType ( tcSplitFunTys, tcSplitTyConApp, + isQualifiedTy, + mkFunTy, mkAppTy, mkTyConTy, + mkTyConApp, mkClassPred, tcFunArgTy, isTauTy, tyVarsOfType, tyVarsOfTypes, - isSigmaTy, splitAlgTyConApp, splitAlgTyConApp_maybe, liftedTypeKind, openTypeKind, mkArrowKind, + tcSplitSigmaTy, tcTyConAppTyCon, tidyOpenType ) -import TyCon ( TyCon, tyConTyVars ) -import Subst ( mkTopTyVarSubst, substClasses, substTy ) +import FieldLabel ( FieldLabel, fieldLabelName, fieldLabelType, fieldLabelTyCon ) +import Id ( idType, recordSelectorFieldLabel, isRecordSelector ) +import DataCon ( dataConFieldLabels, dataConSig, + dataConStrictMarks + ) +import Name ( Name ) +import TyCon ( TyCon, tyConTyVars, isAlgTyCon, tyConDataCons ) +import Subst ( mkTopTyVarSubst, substTheta, substTy ) import VarSet ( elemVarSet ) import TysWiredIn ( boolTy, mkListTy, listTyCon ) -import TcUnify ( unifyTauTy, unifyFunTy, unifyListTy, unifyTupleTy ) import PrelNames ( cCallableClassName, cReturnableClassName, - enumFromName, enumFromThenName, negateName, + enumFromName, enumFromThenName, enumFromToName, enumFromThenToName, thenMName, failMName, returnMName, ioTyConName ) import Outputable -import Maybes ( maybeToBool, mapMaybe ) import ListSetOps ( minusList ) import Util import CmdLineOpts @@ -82,12 +79,12 @@ tcExpr :: RenamedHsExpr -- Expession to type check -> TcType -- Expected type (could be a polytpye) -> TcM (TcExpr, LIE) -tcExpr expr ty | isSigmaTy ty = -- Polymorphic case - tcPolyExpr expr ty `thenTc` \ (expr', lie, _, _, _) -> - returnTc (expr', lie) +tcExpr expr ty | isQualifiedTy ty = -- Polymorphic case + tcPolyExpr expr ty `thenTc` \ (expr', lie, _, _, _) -> + returnTc (expr', lie) - | otherwise = -- Monomorphic case - tcMonoExpr expr ty + | otherwise = -- Monomorphic case + tcMonoExpr expr ty \end{code} @@ -196,9 +193,8 @@ tcMonoExpr (HsLit lit) res_ty = tcLit lit res_ty tcMonoExpr (HsOverLit lit) res_ty = newOverloadedLit (LiteralOrigin lit) lit res_ty tcMonoExpr (HsPar expr) res_ty = tcMonoExpr expr res_ty -tcMonoExpr (NegApp expr) res_ty - = tcLookupSyntaxName negateName `thenNF_Tc` \ neg -> - tcMonoExpr (HsApp (HsVar neg) expr) res_ty +tcMonoExpr (NegApp expr neg_name) res_ty + = tcMonoExpr (HsApp (HsVar neg_name) expr) res_ty tcMonoExpr (HsLam match) res_ty = tcMatchLambda match res_ty `thenTc` \ (match',lie) -> @@ -262,15 +258,25 @@ arg/result types); unify them with the args/result; and store them for later use. \begin{code} -tcMonoExpr (HsCCall lbl args may_gc is_asm ignored_fake_result_ty) res_ty - = -- Get the callable and returnable classes. +tcMonoExpr e0@(HsCCall lbl args may_gc is_casm ignored_fake_result_ty) res_ty + + = getDOptsTc `thenNF_Tc` \ dflags -> + + checkTc (not (is_casm && dopt_HscLang dflags /= HscC)) + (vcat [text "_casm_ is only supported when compiling via C (-fvia-C).", + text "Either compile with -fvia-C, or, better, rewrite your code", + text "to use the foreign function interface. _casm_s are deprecated", + text "and support for them may one day disappear."]) + `thenTc_` + + -- Get the callable and returnable classes. tcLookupClass cCallableClassName `thenNF_Tc` \ cCallableClass -> tcLookupClass cReturnableClassName `thenNF_Tc` \ cReturnableClass -> tcLookupTyCon ioTyConName `thenNF_Tc` \ ioTyCon -> let new_arg_dict (arg, arg_ty) - = newClassDicts (CCallOrigin (_UNPK_ lbl) (Just arg)) - [(cCallableClass, [arg_ty])] `thenNF_Tc` \ arg_dicts -> + = newDicts (CCallOrigin (_UNPK_ lbl) (Just arg)) + [mkClassPred cCallableClass [arg_ty]] `thenNF_Tc` \ arg_dicts -> returnNF_Tc arg_dicts -- Actually a singleton bag result_origin = CCallOrigin (_UNPK_ lbl) Nothing {- Not an arg -} @@ -296,8 +302,8 @@ tcMonoExpr (HsCCall lbl args may_gc is_asm ignored_fake_result_ty) res_ty -- Construct the extra insts, which encode the -- constraints on the argument and result types. mapNF_Tc new_arg_dict (zipEqual "tcMonoExpr:CCall" args arg_tys) `thenNF_Tc` \ ccarg_dicts_s -> - newClassDicts result_origin [(cReturnableClass, [result_ty])] `thenNF_Tc` \ ccres_dict -> - returnTc (HsCCall lbl args' may_gc is_asm io_result_ty, + newDicts result_origin [mkClassPred cReturnableClass [result_ty]] `thenNF_Tc` \ ccres_dict -> + returnTc (HsCCall lbl args' may_gc is_casm io_result_ty, mkLIE (ccres_dict ++ concat ccarg_dicts_s) `plusLIE` args_lie) \end{code} @@ -360,10 +366,10 @@ tcMonoExpr expr@(HsDo do_or_lc stmts src_loc) res_ty \end{code} \begin{code} -tcMonoExpr in_expr@(ExplicitList exprs) res_ty -- Non-empty list +tcMonoExpr in_expr@(ExplicitList _ exprs) res_ty -- Non-empty list = unifyListTy res_ty `thenTc` \ elt_ty -> mapAndUnzipTc (tc_elt elt_ty) exprs `thenTc` \ (exprs', lies) -> - returnTc (ExplicitListOut elt_ty exprs', plusLIEs lies) + returnTc (ExplicitList elt_ty exprs', plusLIEs lies) where tc_elt elt_ty expr = tcAddErrCtxt (listCtxt expr) $ @@ -380,10 +386,10 @@ tcMonoExpr expr@(RecordCon con_name rbinds) res_ty = tcAddErrCtxt (recordConCtxt expr) $ tcId con_name `thenNF_Tc` \ (con_expr, con_lie, con_tau) -> let - (_, record_ty) = splitFunTys con_tau - (tycon, ty_args, _) = splitAlgTyConApp record_ty + (_, record_ty) = tcSplitFunTys con_tau + (tycon, ty_args) = tcSplitTyConApp record_ty in - ASSERT( maybeToBool (splitAlgTyConApp_maybe record_ty ) ) + ASSERT( isAlgTyCon tycon ) unifyTauTy res_ty record_ty `thenTc_` -- Check that the record bindings match the constructor @@ -401,14 +407,11 @@ tcMonoExpr expr@(RecordCon con_name rbinds) res_ty tcRecordBinds tycon ty_args rbinds `thenTc` \ (rbinds', rbinds_lie) -> let - missing_s_fields = missingStrictFields rbinds data_con + (missing_s_fields, missing_fields) = missingFields rbinds data_con in checkTcM (null missing_s_fields) (mapNF_Tc (addErrTc . missingStrictFieldCon con_name) missing_s_fields `thenNF_Tc_` returnNF_Tc ()) `thenNF_Tc_` - let - missing_fields = missingFields rbinds data_con - in doptsTc Opt_WarnMissingFields `thenNF_Tc` \ warn -> checkTcM (not (warn && not (null missing_fields))) (mapNF_Tc ((warnTc True) . missingFieldCon con_name) missing_fields `thenNF_Tc_` @@ -465,11 +468,13 @@ tcMonoExpr expr@(RecordUpd record_expr rbinds) res_ty -- STEP 1 -- Figure out the tycon and data cons from the first field name let - (Just (AnId sel_id) : _) = maybe_sel_ids - (_, _, tau) = splitSigmaTy (idType sel_id) -- Selectors can be overloaded + -- It's OK to use the non-tc splitters here (for a selector) + (Just (AnId sel_id) : _) = maybe_sel_ids + (_, _, tau) = tcSplitSigmaTy (idType sel_id) -- Selectors can be overloaded -- when the data type has a context - Just (data_ty, _) = splitFunTy_maybe tau -- Must succeed since sel_id is a selector - (tycon, _, data_cons) = splitAlgTyConApp data_ty + data_ty = tcFunArgTy tau -- Must succeed since sel_id is a selector + tycon = tcTyConAppTyCon data_ty + data_cons = tyConDataCons tycon (con_tyvars, _, _, _, _, _) = dataConSig (head data_cons) in tcInstTyVars con_tyvars `thenNF_Tc` \ (_, result_inst_tys, _) -> @@ -533,12 +538,12 @@ tcMonoExpr expr@(RecordUpd record_expr rbinds) res_ty let (tyvars, theta, _, _, _, _) = dataConSig (head data_cons) inst_env = mkTopTyVarSubst tyvars result_inst_tys - theta' = substClasses inst_env theta + theta' = substTheta inst_env theta in - newClassDicts RecordUpdOrigin theta' `thenNF_Tc` \ dicts -> + newDicts RecordUpdOrigin theta' `thenNF_Tc` \ dicts -> -- Phew! - returnTc (RecordUpdOut record_expr' result_record_ty (map instToId dicts) rbinds', + returnTc (RecordUpdOut record_expr' record_ty result_record_ty (map instToId dicts) rbinds', mkLIE dicts `plusLIE` record_lie `plusLIE` rbinds_lie) tcMonoExpr (ArithSeqIn seq@(From expr)) res_ty @@ -598,10 +603,10 @@ tcMonoExpr in_expr@(ArithSeqIn seq@(FromThenTo expr1 expr2 expr3)) res_ty \begin{code} tcMonoExpr in_expr@(ExprWithTySig expr poly_ty) res_ty - = tcSetErrCtxt (exprSigCtxt in_expr) $ - tcHsSigType poly_ty `thenTc` \ sig_tc_ty -> + = tcHsSigType ExprSigCtxt poly_ty `thenTc` \ sig_tc_ty -> - if not (isSigmaTy sig_tc_ty) then + tcAddErrCtxt (exprSigCtxt in_expr) $ + if not (isQualifiedTy sig_tc_ty) then -- Easy case unifyTauTy sig_tc_ty res_ty `thenTc_` tcMonoExpr expr sig_tc_ty @@ -630,7 +635,10 @@ Implicit Parameter bindings. tcMonoExpr (HsWith expr binds) res_ty = tcMonoExpr expr res_ty `thenTc` \ (expr', expr_lie) -> mapAndUnzipTc tcIPBind binds `thenTc` \ (pairs, bind_lies) -> - tcSimplifyIPs (map fst binds) expr_lie `thenTc` \ (expr_lie', dict_binds) -> + + -- If the binding binds ?x = E, we must now + -- discharge any ?x constraints in expr_lie + tcSimplifyIPs (map fst pairs) expr_lie `thenTc` \ (expr_lie', dict_binds) -> let binds' = [(instToId ip, rhs) | (ip,rhs) <- pairs] expr'' = HsLet (mkMonoBind dict_binds [] Recursive) expr' @@ -645,22 +653,6 @@ tcIPBind (name, expr) returnTc ((ip, expr'), lie) \end{code} -Typecheck expression which in most cases will be an Id. - -\begin{code} -tcExpr_id :: RenamedHsExpr - -> TcM (TcExpr, - LIE, - TcType) -tcExpr_id id_expr - = case id_expr of - HsVar name -> tcId name `thenNF_Tc` \ stuff -> - returnTc stuff - other -> newTyVarTy openTypeKind `thenNF_Tc` \ id_ty -> - tcMonoExpr id_expr id_ty `thenTc` \ (id_expr', lie_id) -> - returnTc (id_expr', lie_id, id_ty) -\end{code} - %************************************************************************ %* * \subsection{@tcApp@ typchecks an application} @@ -709,8 +701,8 @@ checkArgsCtxt fun args expected_res_ty actual_res_ty tidy_env let (env1, exp_ty'') = tidyOpenType tidy_env exp_ty' (env2, act_ty'') = tidyOpenType env1 act_ty' - (exp_args, _) = splitFunTys exp_ty'' - (act_args, _) = splitFunTys act_ty'' + (exp_args, _) = tcSplitFunTys exp_ty'' + (act_args, _) = tcSplitFunTys act_ty'' message | length exp_args < length act_args = wrongArgsCtxt "too few" fun args | length exp_args > length act_args = wrongArgsCtxt "too many" fun args @@ -753,15 +745,22 @@ tcArg the_fun (arg, expected_arg_ty, arg_no) \begin{code} tcId :: Name -> NF_TcM (TcExpr, LIE, TcType) +tcId name -- Look up the Id and instantiate its type + = tcLookupId name `thenNF_Tc` \ id -> + tcInstId id +\end{code} + +Typecheck expression which in most cases will be an Id. -tcId name - = -- Look up the Id and instantiate its type - tcLookup name `thenNF_Tc` \ thing -> - case thing of - ATcId tc_id -> tcInstId tc_id - AGlobal (AnId id) -> tcInstId id +\begin{code} +tcExpr_id :: RenamedHsExpr -> TcM (TcExpr, LIE, TcType) +tcExpr_id (HsVar name) = tcId name +tcExpr_id expr = newTyVarTy openTypeKind `thenNF_Tc` \ id_ty -> + tcMonoExpr expr id_ty `thenTc` \ (expr', lie_id) -> + returnTc (expr', lie_id, id_ty) \end{code} + %************************************************************************ %* * \subsection{@tcDoStmts@ typechecks a {\em list} of do statements} @@ -784,11 +783,11 @@ tcDoStmts do_or_lc stmts src_loc res_ty _ -> newTyVarTy (mkArrowKind liftedTypeKind liftedTypeKind) `thenNF_Tc` \ m_ty -> newTyVarTy liftedTypeKind `thenNF_Tc` \ elt_ty -> - unifyTauTy res_ty (mkAppTy m_ty elt_ty) `thenTc_` + unifyTauTy res_ty (mkAppTy m_ty elt_ty) `thenTc_` returnNF_Tc (m_ty, (mkAppTy m_ty, elt_ty)) ) `thenNF_Tc` \ (tc_ty, m_ty) -> - tcStmts do_or_lc m_ty stmts `thenTc` \ (stmts', stmts_lie) -> + tcStmts (DoCtxt do_or_lc) m_ty stmts `thenTc` \ (stmts', stmts_lie) -> -- Build the then and zero methods in case we need them -- It's important that "then" and "return" appear just once in the final LIE, @@ -875,35 +874,32 @@ badFields rbinds data_con where field_names = map fieldLabelName (dataConFieldLabels data_con) -missingStrictFields rbinds data_con - = [ fn | fn <- strict_field_names, - not (fn `elem` field_names_used) - ] - where - field_names_used = [ field_name | (field_name, _, _) <- rbinds ] - strict_field_names = mapMaybe isStrict field_info - - isStrict (fl, MarkedStrict) = Just (fieldLabelName fl) - isStrict _ = Nothing - - field_info = zip (dataConFieldLabels data_con) - (dataConStrictMarks data_con) - missingFields rbinds data_con - = [ fn | fn <- non_strict_field_names, not (fn `elem` field_names_used) ] + | null field_labels = ([], []) -- Not declared as a record; + -- But C{} is still valid + | otherwise + = (missing_strict_fields, other_missing_fields) where - field_names_used = [ field_name | (field_name, _, _) <- rbinds ] - - -- missing strict fields have already been flagged as - -- being so, so leave them out here. - non_strict_field_names = mapMaybe isn'tStrict field_info - - isn'tStrict (fl, MarkedStrict) = Nothing - isn'tStrict (fl, _) = Just (fieldLabelName fl) - - field_info = zip (dataConFieldLabels data_con) - (dataConStrictMarks data_con) + missing_strict_fields + = [ fl | (fl, str) <- field_info, + isMarkedStrict str, + not (fieldLabelName fl `elem` field_names_used) + ] + other_missing_fields + = [ fl | (fl, str) <- field_info, + not (isMarkedStrict str), + not (fieldLabelName fl `elem` field_names_used) + ] + field_names_used = [ field_name | (field_name, _, _) <- rbinds ] + field_labels = dataConFieldLabels data_con + + field_info = zipEqual "missingFields" + field_labels + (drop (length ex_theta) (dataConStrictMarks data_con)) + -- The 'drop' is because dataConStrictMarks + -- includes the existential dictionaries + (_, _, _, ex_theta, _, _) = dataConSig data_con \end{code} %************************************************************************ @@ -935,8 +931,8 @@ Overloaded literals. tcLit :: HsLit -> TcType -> TcM (TcExpr, LIE) tcLit (HsLitLit s _) res_ty = tcLookupClass cCallableClassName `thenNF_Tc` \ cCallableClass -> - newClassDicts (LitLitOrigin (_UNPK_ s)) - [(cCallableClass,[res_ty])] `thenNF_Tc` \ dicts -> + newDicts (LitLitOrigin (_UNPK_ s)) + [mkClassPred cCallableClass [res_ty]] `thenNF_Tc` \ dicts -> returnTc (HsLit (HsLitLit s res_ty), mkLIE dicts) tcLit lit res_ty @@ -953,11 +949,6 @@ tcLit lit res_ty Mini-utils: -\begin{code} -pp_nest_hang :: String -> SDoc -> SDoc -pp_nest_hang lbl stuff = nest 2 (hang (text lbl) 4 stuff) -\end{code} - Boring and alphabetical: \begin{code} arithSeqCtxt expr @@ -1020,12 +1011,12 @@ recordConCtxt expr = ptext SLIT("In the record construction:") <+> ppr expr notSelector field = hsep [quotes (ppr field), ptext SLIT("is not a record selector")] -missingStrictFieldCon :: Name -> Name -> SDoc +missingStrictFieldCon :: Name -> FieldLabel -> SDoc missingStrictFieldCon con field = hsep [ptext SLIT("Constructor") <+> quotes (ppr con), ptext SLIT("does not have the required strict field"), quotes (ppr field)] -missingFieldCon :: Name -> Name -> SDoc +missingFieldCon :: Name -> FieldLabel -> SDoc missingFieldCon con field = hsep [ptext SLIT("Field") <+> quotes (ppr field), ptext SLIT("is not initialised")]