X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Frename%2FRnTypes.lhs;h=3086b946d3da93503ff037fe7322287ff0606065;hp=dd1851da76535d5d5680e1ecbfaba2cfbfe94cd6;hb=432b9c9322181a3644083e3c19b7e240d90659e7;hpb=ec8a6628b5f58655990bd07bad791079ed04e8b8 diff --git a/compiler/rename/RnTypes.lhs b/compiler/rename/RnTypes.lhs index dd1851d..3086b94 100644 --- a/compiler/rename/RnTypes.lhs +++ b/compiler/rename/RnTypes.lhs @@ -4,53 +4,40 @@ \section[RnSource]{Main pass of renamer} \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 RnTypes ( -- Type related stuff rnHsType, rnLHsType, rnLHsTypes, rnContext, - rnHsSigType, rnHsTypeFVs, + rnHsSigType, rnHsTypeFVs, rnConDeclFields, -- Precence related stuff mkOpAppRn, mkNegAppRn, mkOpFormRn, mkConOpPatRn, - checkPrecMatch, checkSectionPrec + checkPrecMatch, checkSectionPrec, + + -- Splice related stuff + rnSplice, checkTH ) where +import {-# SOURCE #-} RnExpr( rnLExpr ) + import DynFlags import HsSyn import RdrHsSyn ( extractHsRhoRdrTyVars ) -import RnHsSyn ( extractHsTyNames, parrTyCon_name, tupleTyCon_name, - listTyCon_name - ) -import RnHsDoc ( rnLHsDoc ) -import RnEnv ( lookupOccRn, lookupBndrRn, lookupSyntaxName, - lookupLocatedOccRn, lookupLocatedBndrRn, - lookupLocatedGlobalOccRn, bindTyVarsRn, - lookupFixityRn, lookupTyFixityRn, lookupConstructorFields, - lookupRecordBndr, mapFvRn, - newIPNameRn, bindPatSigTyVarsFV) +import RnHsSyn ( extractHsTyNames ) +import RnHsDoc ( rnLHsDoc, rnMbLHsDoc ) +import RnEnv import TcRnMonad import RdrName -import PrelNames ( eqClassName, integralClassName, geName, eqName, - negateName, minusName, lengthPName, indexPName, - plusIntegerName, fromIntegerName, timesIntegerName, - ratioDataConName, fromRationalName, fromStringName ) -import TypeRep ( funTyCon ) -import Constants ( mAX_TUPLE_SIZE ) +import PrelNames +import TypeRep ( funTyConName ) import Name import SrcLoc import NameSet -import Literal ( inIntRange, inCharRange ) import BasicTypes ( compareFixity, funTyFixity, negateFixity, Fixity(..), FixityDirection(..) ) -import ListSetOps ( removeDups, minusList ) import Outputable +import FastString +import Control.Monad ( unless ) #include "HsVersions.h" \end{code} @@ -117,34 +104,43 @@ rnHsType doc (HsForAllTy Explicit forall_tyvars ctxt tau) = do mapM_ (forAllWarn doc tau) warn_guys rnForAll doc Explicit forall_tyvars ctxt tau -rnHsType doc (HsTyVar tyvar) = do +rnHsType _ (HsTyVar tyvar) = do tyvar' <- lookupOccRn tyvar return (HsTyVar tyvar') +-- If we see (forall a . ty), without foralls on, the forall will give +-- a sensible error message, but we don't want to complain about the dot too +-- Hence the jiggery pokery with ty1 rnHsType doc ty@(HsOpTy ty1 (L loc op) ty2) = setSrcSpan loc $ - do { ty_ops_ok <- doptM Opt_TypeOperators - ; checkErr ty_ops_ok (opTyErr op ty) - ; op' <- lookupOccRn op + do { ops_ok <- doptM Opt_TypeOperators + ; op' <- if ops_ok + then lookupOccRn op + else do { addErr (opTyErr op ty) + ; return (mkUnboundName op) } -- Avoid double complaint ; let l_op' = L loc op' ; fix <- lookupTyFixityRn l_op' ; ty1' <- rnLHsType doc ty1 ; ty2' <- rnLHsType doc ty2 - ; mkHsOpTyRn (\t1 t2 -> HsOpTy t1 l_op' t2) (ppr op') fix ty1' ty2' } + ; mkHsOpTyRn (\t1 t2 -> HsOpTy t1 l_op' t2) op' fix ty1' ty2' } rnHsType doc (HsParTy ty) = do ty' <- rnLHsType doc ty return (HsParTy ty') -rnHsType doc (HsBangTy b ty) = do - ty' <- rnLHsType doc ty - return (HsBangTy b ty') +rnHsType doc (HsBangTy b ty) + = do { ty' <- rnLHsType doc ty + ; return (HsBangTy b ty') } -rnHsType doc (HsNumTy i) +rnHsType doc (HsRecTy flds) + = do { flds' <- rnConDeclFields doc flds + ; return (HsRecTy flds') } + +rnHsType _ (HsNumTy i) | i == 1 = return (HsNumTy i) | otherwise = addErr err_msg >> return (HsNumTy i) where - err_msg = ptext SLIT("Only unit numeric type pattern is valid") + err_msg = ptext (sLit "Only unit numeric type pattern is valid") rnHsType doc (HsFunTy ty1 ty2) = do @@ -155,15 +151,17 @@ rnHsType doc (HsFunTy ty1 ty2) = do -- when we find return :: forall m. Monad m -> forall a. a -> m a -- Check for fixity rearrangements - mkHsOpTyRn HsFunTy (ppr funTyCon) funTyFixity ty1' ty2' + mkHsOpTyRn HsFunTy funTyConName funTyFixity ty1' ty2' rnHsType doc (HsListTy ty) = do ty' <- rnLHsType doc ty return (HsListTy ty') -rnHsType doc (HsKindSig ty k) = do - ty' <- rnLHsType doc ty - return (HsKindSig ty' k) +rnHsType doc (HsKindSig ty k) + = do { kind_sigs_ok <- doptM Opt_KindSignatures + ; checkM kind_sigs_ok (addErr (kindSigErr ty)) + ; ty' <- rnLHsType doc ty + ; return (HsKindSig ty' k) } rnHsType doc (HsPArrTy ty) = do ty' <- rnLHsType doc ty @@ -184,15 +182,17 @@ rnHsType doc (HsPredTy pred) = do pred' <- rnPred doc pred return (HsPredTy pred') -rnHsType doc (HsSpliceTy _) = do - addErr (ptext SLIT("Type splices are not yet implemented")) - failM +rnHsType _ (HsSpliceTy sp) + = do { (sp', _fvs) <- rnSplice sp -- ToDo: deal with fvs + ; return (HsSpliceTy sp') } rnHsType doc (HsDocTy ty haddock_doc) = do ty' <- rnLHsType doc ty haddock_doc' <- rnLHsDoc haddock_doc return (HsDocTy ty' haddock_doc') +rnLHsTypes :: SDoc -> [LHsType RdrName] + -> IOEnv (Env TcGblEnv TcLclEnv) [LHsType Name] rnLHsTypes doc tys = mapM (rnLHsType doc) tys \end{code} @@ -201,7 +201,7 @@ rnLHsTypes doc tys = mapM (rnLHsType doc) tys rnForAll :: SDoc -> HsExplicitForAll -> [LHsTyVarBndr RdrName] -> LHsContext RdrName -> LHsType RdrName -> RnM (HsType Name) -rnForAll doc exp [] (L _ []) (L _ ty) = rnHsType doc ty +rnForAll doc _ [] (L _ []) (L _ ty) = rnHsType doc ty -- One reason for this case is that a type like Int# -- starts off as (HsForAllTy Nothing [] Int), in case -- there is some quantification. Now that we have quantified @@ -217,6 +217,16 @@ rnForAll doc exp forall_tyvars ctxt ty return (HsForAllTy exp new_tyvars new_ctxt new_ty) -- Retain the same implicit/explicit flag as before -- so that we can later print it correctly + +rnConDeclFields :: SDoc -> [ConDeclField RdrName] -> RnM [ConDeclField Name] +rnConDeclFields doc fields = mapM (rnField doc) fields + +rnField :: SDoc -> ConDeclField RdrName -> RnM (ConDeclField Name) +rnField doc (ConDeclField name ty haddock_doc) + = do { new_name <- lookupLocatedTopBndrRn name + ; new_ty <- rnLHsType doc ty + ; new_haddock_doc <- rnMbLHsDoc haddock_doc + ; return (ConDeclField new_name new_ty new_haddock_doc) } \end{code} %********************************************************* @@ -235,6 +245,8 @@ rnContext' doc ctxt = mapM (rnLPred doc) ctxt rnLPred :: SDoc -> LHsPred RdrName -> RnM (LHsPred Name) rnLPred doc = wrapLocM (rnPred doc) +rnPred :: SDoc -> HsPred RdrName + -> IOEnv (Env TcGblEnv TcLclEnv) (HsPred Name) rnPred doc (HsClassP clas tys) = do { clas_name <- lookupOccRn clas ; tys' <- rnLHsTypes doc tys @@ -281,36 +293,35 @@ by the presence of ->, which is a separate syntactic construct. --------------- -- Building (ty1 `op1` (ty21 `op2` ty22)) mkHsOpTyRn :: (LHsType Name -> LHsType Name -> HsType Name) - -> SDoc -> Fixity -> LHsType Name -> LHsType Name + -> Name -> Fixity -> LHsType Name -> LHsType Name -> RnM (HsType Name) mkHsOpTyRn mk1 pp_op1 fix1 ty1 (L loc2 (HsOpTy ty21 op2 ty22)) = do { fix2 <- lookupTyFixityRn op2 ; mk_hs_op_ty mk1 pp_op1 fix1 ty1 (\t1 t2 -> HsOpTy t1 op2 t2) - (ppr op2) fix2 ty21 ty22 loc2 } + (unLoc op2) fix2 ty21 ty22 loc2 } -mkHsOpTyRn mk1 pp_op1 fix1 ty1 ty2@(L loc2 (HsFunTy ty21 ty22)) +mkHsOpTyRn mk1 pp_op1 fix1 ty1 (L loc2 (HsFunTy ty21 ty22)) = mk_hs_op_ty mk1 pp_op1 fix1 ty1 - HsFunTy (ppr funTyCon) funTyFixity ty21 ty22 loc2 + HsFunTy funTyConName funTyFixity ty21 ty22 loc2 -mkHsOpTyRn mk1 pp_op1 fix1 ty1 ty2 -- Default case, no rearrangment +mkHsOpTyRn mk1 _ _ ty1 ty2 -- Default case, no rearrangment = return (mk1 ty1 ty2) --------------- mk_hs_op_ty :: (LHsType Name -> LHsType Name -> HsType Name) - -> SDoc -> Fixity -> LHsType Name + -> Name -> Fixity -> LHsType Name -> (LHsType Name -> LHsType Name -> HsType Name) - -> SDoc -> Fixity -> LHsType Name -> LHsType Name -> SrcSpan + -> Name -> Fixity -> LHsType Name -> LHsType Name -> SrcSpan -> RnM (HsType Name) -mk_hs_op_ty mk1 pp_op1 fix1 ty1 - mk2 pp_op2 fix2 ty21 ty22 loc2 - | nofix_error = do { addErr (precParseErr (quotes pp_op1,fix1) - (quotes pp_op2,fix2)) +mk_hs_op_ty mk1 op1 fix1 ty1 + mk2 op2 fix2 ty21 ty22 loc2 + | nofix_error = do { precParseErr (op1,fix1) (op2,fix2) ; return (mk1 ty1 (L loc2 (mk2 ty21 ty22))) } | associate_right = return (mk1 ty1 (L loc2 (mk2 ty21 ty22))) | otherwise = do { -- Rearrange to ((ty1 `op1` ty21) `op2` ty22) - new_ty <- mkHsOpTyRn mk1 pp_op1 fix1 ty1 ty21 + new_ty <- mkHsOpTyRn mk1 op1 fix1 ty1 ty21 ; return (mk2 (noLoc new_ty) ty22) } where (nofix_error, associate_right) = compareFixity fix1 fix2 @@ -325,9 +336,9 @@ mkOpAppRn :: LHsExpr Name -- Left operand; already rearranged -- (e11 `op1` e12) `op2` e2 mkOpAppRn e1@(L _ (OpApp e11 op1 fix1 e12)) op2 fix2 e2 - | nofix_error = do - addErr (precParseErr (ppr_op op1,fix1) (ppr_op op2,fix2)) - return (OpApp e1 op2 fix2 e2) + | nofix_error + = do precParseErr (get_op op1,fix1) (get_op op2,fix2) + return (OpApp e1 op2 fix2 e2) | associate_right = do new_e <- mkOpAppRn e12 op2 fix2 e2 @@ -339,23 +350,23 @@ mkOpAppRn e1@(L _ (OpApp e11 op1 fix1 e12)) op2 fix2 e2 --------------------------- -- (- neg_arg) `op` e2 mkOpAppRn e1@(L _ (NegApp neg_arg neg_name)) op2 fix2 e2 - | nofix_error = do - addErr (precParseErr (pp_prefix_minus,negateFixity) (ppr_op op2,fix2)) - return (OpApp e1 op2 fix2 e2) + | nofix_error + = do precParseErr (negateName,negateFixity) (get_op op2,fix2) + return (OpApp e1 op2 fix2 e2) - | associate_right = do - new_e <- mkOpAppRn neg_arg op2 fix2 e2 - return (NegApp (L loc' new_e) neg_name) + | associate_right + = do new_e <- mkOpAppRn neg_arg op2 fix2 e2 + return (NegApp (L loc' new_e) neg_name) where loc' = combineLocs neg_arg e2 (nofix_error, associate_right) = compareFixity negateFixity fix2 --------------------------- -- e1 `op` - neg_arg -mkOpAppRn e1 op1 fix1 e2@(L _ (NegApp neg_arg _)) -- NegApp can occur on the right - | not associate_right= do -- We *want* right association - addErr (precParseErr (ppr_op op1, fix1) (pp_prefix_minus, negateFixity)) - return (OpApp e1 op1 fix1 e2) +mkOpAppRn e1 op1 fix1 e2@(L _ (NegApp _ _)) -- NegApp can occur on the right + | not associate_right -- We *want* right association + = do precParseErr (get_op op1, fix1) (negateName, negateFixity) + return (OpApp e1 op1 fix1 e2) where (_, associate_right) = compareFixity fix1 negateFixity @@ -367,14 +378,20 @@ mkOpAppRn e1 op fix e2 -- Default case, no rearrangment ) return (OpApp e1 op fix e2) +---------------------------- +get_op :: LHsExpr Name -> Name +get_op (L _ (HsVar n)) = n +get_op other = pprPanic "get_op" (ppr other) + -- Parser left-associates everything, but -- derived instances may have correctly-associated things to -- in the right operarand. So we just check that the right operand is OK +right_op_ok :: Fixity -> HsExpr Name -> Bool right_op_ok fix1 (OpApp _ _ fix2 _) = not error_please && associate_right where (error_please, associate_right) = compareFixity fix1 fix2 -right_op_ok fix1 other +right_op_ok _ _ = True -- Parser initially makes negation bind more tightly than any other operator @@ -384,8 +401,9 @@ mkNegAppRn neg_arg neg_name = ASSERT( not_op_app (unLoc neg_arg) ) return (NegApp neg_arg neg_name) +not_op_app :: HsExpr id -> Bool not_op_app (OpApp _ _ _ _) = False -not_op_app other = True +not_op_app _ = True --------------------------- mkOpFormRn :: LHsCmdTop Name -- Left operand; already rearranged @@ -396,14 +414,14 @@ mkOpFormRn :: LHsCmdTop Name -- Left operand; already rearranged -- (e11 `op1` e12) `op2` e2 mkOpFormRn a1@(L loc (HsCmdTop (L _ (HsArrForm op1 (Just fix1) [a11,a12])) _ _ _)) op2 fix2 a2 - | nofix_error = do - addErr (precParseErr (ppr_op op1,fix1) (ppr_op op2,fix2)) - return (HsArrForm op2 (Just fix2) [a1, a2]) - - | associate_right = do - new_c <- mkOpFormRn a12 op2 fix2 a2 - return (HsArrForm op1 (Just fix1) - [a11, L loc (HsCmdTop (L loc new_c) [] placeHolderType [])]) + | nofix_error + = do precParseErr (get_op op1,fix1) (get_op op2,fix2) + return (HsArrForm op2 (Just fix2) [a1, a2]) + + | associate_right + = do new_c <- mkOpFormRn a12 op2 fix2 a2 + return (HsArrForm op1 (Just fix1) + [a11, L loc (HsCmdTop (L loc new_c) [] placeHolderType [])]) -- TODO: locs are wrong where (nofix_error, associate_right) = compareFixity fix1 fix2 @@ -422,7 +440,7 @@ mkConOpPatRn op2 fix2 p1@(L loc (ConPatIn op1 (InfixCon p11 p12))) p2 ; let (nofix_error, associate_right) = compareFixity fix1 fix2 ; if nofix_error then do - { addErr (precParseErr (ppr_op op1,fix1) (ppr_op op2,fix2)) + { precParseErr (unLoc op1,fix1) (unLoc op2,fix2) ; return (ConPatIn op2 (InfixCon p1 p2)) } else if associate_right then do @@ -430,19 +448,20 @@ mkConOpPatRn op2 fix2 p1@(L loc (ConPatIn op1 (InfixCon p11 p12))) p2 ; return (ConPatIn op1 (InfixCon p11 (L loc new_p))) } -- XXX loc right? else return (ConPatIn op2 (InfixCon p1 p2)) } -mkConOpPatRn op fix p1 p2 -- Default case, no rearrangment +mkConOpPatRn op _ p1 p2 -- Default case, no rearrangment = ASSERT( not_op_pat (unLoc p2) ) return (ConPatIn op (InfixCon p1 p2)) +not_op_pat :: Pat Name -> Bool not_op_pat (ConPatIn _ (InfixCon _ _)) = False -not_op_pat other = True +not_op_pat _ = True -------------------------------------- checkPrecMatch :: Bool -> Name -> MatchGroup Name -> RnM () -- True indicates an infix lhs -- See comments with rnExpr (OpApp ...) about "deriving" -checkPrecMatch False fn match +checkPrecMatch False _ _ = return () checkPrecMatch True op (MatchGroup ms _) = mapM_ check ms @@ -460,6 +479,7 @@ checkPrecMatch True op (MatchGroup ms _) -- until the type checker). So we don't want to crash on the -- second eqn. +checkPrec :: Name -> Pat Name -> Bool -> IOEnv (Env TcGblEnv TcLclEnv) () checkPrec op (ConPatIn op1 (InfixCon _ _)) right = do op_fix@(Fixity op_prec op_dir) <- lookupFixityRn op op1_fix@(Fixity op1_prec op1_dir) <- lookupFixityRn (unLoc op1) @@ -469,13 +489,12 @@ checkPrec op (ConPatIn op1 (InfixCon _ _)) right = do (op1_dir == InfixR && op_dir == InfixR && right || op1_dir == InfixL && op_dir == InfixL && not right)) - info = (ppr_op op, op_fix) - info1 = (ppr_op op1, op1_fix) + info = (op, op_fix) + info1 = (unLoc op1, op1_fix) (infol, infor) = if right then (info, info1) else (info1, info) + unless inf_ok (precParseErr infol infor) - checkErr inf_ok (precParseErr infol infor) - -checkPrec op pat right +checkPrec _ _ _ = return () -- Check precedence of (arg op) or (op arg) respectively @@ -486,36 +505,47 @@ checkSectionPrec :: FixityDirection -> HsExpr RdrName -> LHsExpr Name -> LHsExpr Name -> RnM () checkSectionPrec direction section op arg = case unLoc arg of - OpApp _ op fix _ -> go_for_it (ppr_op op) fix - NegApp _ _ -> go_for_it pp_prefix_minus negateFixity - other -> return () + OpApp _ op fix _ -> go_for_it (get_op op) fix + NegApp _ _ -> go_for_it negateName negateFixity + _ -> return () where - L _ (HsVar op_name) = op - go_for_it pp_arg_op arg_fix@(Fixity arg_prec assoc) = do + op_name = get_op op + go_for_it arg_op arg_fix@(Fixity arg_prec assoc) = do op_fix@(Fixity op_prec _) <- lookupFixityRn op_name - checkErr (op_prec < arg_prec - || op_prec == arg_prec && direction == assoc) - (sectionPrecErr (ppr_op op_name, op_fix) - (pp_arg_op, arg_fix) section) + unless (op_prec < arg_prec + || (op_prec == arg_prec && direction == assoc)) + (sectionPrecErr (op_name, op_fix) + (arg_op, arg_fix) section) \end{code} Precedence-related error messages \begin{code} -precParseErr op1 op2 - = hang (ptext SLIT("precedence parsing error")) - 4 (hsep [ptext SLIT("cannot mix"), ppr_opfix op1, ptext SLIT("and"), +precParseErr :: (Name, Fixity) -> (Name, Fixity) -> RnM () +precParseErr op1@(n1,_) op2@(n2,_) + | isUnboundName n1 || isUnboundName n2 + = return () -- Avoid error cascade + | otherwise + = addErr $ hang (ptext (sLit "Precedence parsing error")) + 4 (hsep [ptext (sLit "cannot mix"), ppr_opfix op1, ptext (sLit "and"), ppr_opfix op2, - ptext SLIT("in the same infix expression")]) - -sectionPrecErr op arg_op section - = vcat [ptext SLIT("The operator") <+> ppr_opfix op <+> ptext SLIT("of a section"), - nest 4 (ptext SLIT("must have lower precedence than the operand") <+> ppr_opfix arg_op), - nest 4 (ptext SLIT("in the section:") <+> quotes (ppr section))] - -pp_prefix_minus = ptext SLIT("prefix `-'") -ppr_op op = quotes (ppr op) -- Here, op can be a Name or a (Var n), where n is a Name -ppr_opfix (pp_op, fixity) = pp_op <+> brackets (ppr fixity) + ptext (sLit "in the same infix expression")]) + +sectionPrecErr :: (Name, Fixity) -> (Name, Fixity) -> HsExpr RdrName -> RnM () +sectionPrecErr op@(n1,_) arg_op@(n2,_) section + | isUnboundName n1 || isUnboundName n2 + = return () -- Avoid error cascade + | otherwise + = addErr $ vcat [ptext (sLit "The operator") <+> ppr_opfix op <+> ptext (sLit "of a section"), + nest 4 (sep [ptext (sLit "must have lower precedence than that of the operand,"), + nest 2 (ptext (sLit "namely") <+> ppr_opfix arg_op)]), + nest 4 (ptext (sLit "in the section:") <+> quotes (ppr section))] + +ppr_opfix :: (Name, Fixity) -> SDoc +ppr_opfix (op, fixity) = pp_op <+> brackets (ppr fixity) + where + pp_op | op == negateName = ptext (sLit "prefix `-'") + | otherwise = quotes (ppr op) \end{code} %********************************************************* @@ -525,14 +555,80 @@ ppr_opfix (pp_op, fixity) = pp_op <+> brackets (ppr fixity) %********************************************************* \begin{code} +forAllWarn :: SDoc -> LHsType RdrName -> Located RdrName + -> TcRnIf TcGblEnv TcLclEnv () forAllWarn doc ty (L loc tyvar) = ifOptM Opt_WarnUnusedMatches $ - addWarnAt loc (sep [ptext SLIT("The universally quantified type variable") <+> quotes (ppr tyvar), - nest 4 (ptext SLIT("does not appear in the type") <+> quotes (ppr ty))] + addWarnAt loc (sep [ptext (sLit "The universally quantified type variable") <+> quotes (ppr tyvar), + nest 4 (ptext (sLit "does not appear in the type") <+> quotes (ppr ty))] $$ doc) -opTyErr op ty - = hang (ptext SLIT("Illegal operator") <+> quotes (ppr op) <+> ptext SLIT("in type") <+> quotes (ppr ty)) - 2 (parens (ptext SLIT("Use -XTypeOperators to allow operators in types"))) +opTyErr :: RdrName -> HsType RdrName -> SDoc +opTyErr op ty@(HsOpTy ty1 _ _) + = hang (ptext (sLit "Illegal operator") <+> quotes (ppr op) <+> ptext (sLit "in type") <+> quotes (ppr ty)) + 2 extra + where + extra | op == dot_tv_RDR && forall_head ty1 + = perhapsForallMsg + | otherwise + = ptext (sLit "Use -XTypeOperators to allow operators in types") + + forall_head (L _ (HsTyVar tv)) = tv == forall_tv_RDR + forall_head (L _ (HsAppTy ty _)) = forall_head ty + forall_head _other = False +opTyErr _ ty = pprPanic "opTyErr: Not an op" (ppr ty) +\end{code} + +%********************************************************* +%* * + Splices +%* * +%********************************************************* + +Note [Splices] +~~~~~~~~~~~~~~ +Consider + f = ... + h = ...$(thing "f")... + +The splice can expand into literally anything, so when we do dependency +analysis we must assume that it might mention 'f'. So we simply treat +all locally-defined names as mentioned by any splice. This is terribly +brutal, but I don't see what else to do. For example, it'll mean +that every locally-defined thing will appear to be used, so no unused-binding +warnings. But if we miss the dependency, then we might typecheck 'h' before 'f', +and that will crash the type checker because 'f' isn't in scope. + +Currently, I'm not treating a splice as also mentioning every import, +which is a bit inconsistent -- but there are a lot of them. We might +thereby get some bogus unused-import warnings, but we won't crash the +type checker. Not very satisfactory really. + +\begin{code} +rnSplice :: HsSplice RdrName -> RnM (HsSplice Name, FreeVars) +rnSplice (HsSplice n expr) + = do { checkTH expr "splice" + ; loc <- getSrcSpanM + ; [n'] <- newLocalsRn [L loc n] + ; (expr', fvs) <- rnLExpr expr + + -- Ugh! See Note [Splices] above + ; lcl_rdr <- getLocalRdrEnv + ; gbl_rdr <- getGlobalRdrEnv + ; let gbl_names = mkNameSet [gre_name gre | gre <- globalRdrEnvElts gbl_rdr, + isLocalGRE gre] + lcl_names = mkNameSet (occEnvElts lcl_rdr) + + ; return (HsSplice n' expr', fvs `plusFV` lcl_names `plusFV` gbl_names) } + +checkTH :: Outputable a => a -> String -> RnM () +#ifdef GHCI +checkTH _ _ = return () -- OK +#else +checkTH e what -- Raise an error in a stage-1 compiler + = addErr (vcat [ptext (sLit "Template Haskell") <+> text what <+> + ptext (sLit "illegal in a stage-1 compiler"), + nest 2 (ppr e)]) +#endif \end{code}