X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FdeSugar%2FDsUtils.lhs;h=3411ebf2c145fc14866edb4457f80735ab4d77ae;hb=d482ad51c9051d6eb9fbcafd90362949db29f374;hp=12ea7df33372f422ad6b83fc034e27cd7d82cbcd;hpb=b4775e5e760111e2d71fba3c44882dce390edfb2;p=ghc-hetmet.git diff --git a/ghc/compiler/deSugar/DsUtils.lhs b/ghc/compiler/deSugar/DsUtils.lhs index 12ea7df..3411ebf 100644 --- a/ghc/compiler/deSugar/DsUtils.lhs +++ b/ghc/compiler/deSugar/DsUtils.lhs @@ -20,10 +20,11 @@ module DsUtils ( mkCoLetsMatchResult, mkGuardedMatchResult, mkCoPrimCaseMatchResult, mkCoAlgCaseMatchResult, - mkErrorAppDs, mkNilExpr, mkConsExpr, - mkStringLit, mkStringLitFS, mkIntegerLit, + mkErrorAppDs, mkNilExpr, mkConsExpr, mkListExpr, + mkIntExpr, mkCharExpr, + mkStringLit, mkStringLitFS, mkIntegerExpr, - mkSelectorBinds, mkTupleExpr, mkTupleSelector, + mkSelectorBinds, mkTupleExpr, mkTupleSelector, mkCoreTup, selectMatchVar ) where @@ -33,39 +34,37 @@ module DsUtils ( import {-# SOURCE #-} Match ( matchSimply ) import HsSyn -import TcHsSyn ( TypecheckedPat ) -import DsHsSyn ( outPatType, collectTypedPatBinders ) +import TcHsSyn ( TypecheckedPat, hsPatType ) import CoreSyn import DsMonad -import CoreUtils ( exprType, mkIfThenElse ) -import PrelInfo ( iRREFUT_PAT_ERROR_ID ) -import MkId ( rebuildConArgs ) +import CoreUtils ( exprType, mkIfThenElse, mkCoerce ) +import MkId ( iRREFUT_PAT_ERROR_ID, mkReboxingAlt, mkNewTypeBody ) import Id ( idType, Id, mkWildId ) import Literal ( Literal(..), inIntRange, tARGET_MAX_INT ) import TyCon ( isNewTyCon, tyConDataCons ) -import DataCon ( DataCon, dataConStrictMarks, dataConId ) -import Type ( mkFunTy, isUnLiftedType, splitAlgTyConApp, - Type - ) -import TysPrim ( intPrimTy, charPrimTy, floatPrimTy, doublePrimTy ) +import DataCon ( DataCon, dataConSourceArity ) +import Type ( mkFunTy, isUnLiftedType, Type, splitTyConApp ) +import TcType ( tcTyConAppTyCon, isIntTy, isFloatTy, isDoubleTy ) +import TysPrim ( intPrimTy ) import TysWiredIn ( nilDataCon, consDataCon, tupleCon, - stringTy, unitDataConId, unitTy, charTy, charDataCon, intTy, intDataCon, smallIntegerDataCon, - floatTy, floatDataCon, - doubleTy, doubleDataCon, - stringTy - ) + floatDataCon, + doubleDataCon, + stringTy, isPArrFakeCon ) import BasicTypes ( Boxity(..) ) import UniqSet ( mkUniqSet, minusUniqSet, isEmptyUniqSet, UniqSet ) import PrelNames ( unpackCStringName, unpackCStringUtf8Name, - plusIntegerName, timesIntegerName ) + plusIntegerName, timesIntegerName, + lengthPName, indexPName ) import Outputable -import UnicodeUtil ( stringToUtf8 ) +import UnicodeUtil ( intsToUtf8, stringToUtf8 ) +import Util ( isSingleton, notNull ) +import FastString \end{code} @@ -78,23 +77,22 @@ import UnicodeUtil ( stringToUtf8 ) \begin{code} tidyLitPat :: HsLit -> TypecheckedPat -> TypecheckedPat -tidyLitPat (HsChar c) pat = ConPat charDataCon charTy [] [] [LitPat (HsCharPrim c) charPrimTy] +tidyLitPat (HsChar c) pat = mkCharLitPat c tidyLitPat lit pat = pat tidyNPat :: HsLit -> Type -> TypecheckedPat -> TypecheckedPat tidyNPat (HsString s) _ pat - | _LENGTH_ s <= 1 -- Short string literals only - = foldr (\c pat -> ConPat consDataCon stringTy [] [] [mk_char_lit c,pat]) - (ConPat nilDataCon stringTy [] [] []) (_UNPK_INT_ s) + | lengthFS s <= 1 -- Short string literals only + = foldr (\c pat -> mkPrefixConPat consDataCon [mkCharLitPat c,pat] stringTy) + (mkNilPat stringTy) (unpackIntFS s) -- The stringTy is the type of the whole pattern, not -- the type to instantiate (:) or [] with! where - mk_char_lit c = ConPat charDataCon charTy [] [] [LitPat (HsCharPrim c) charPrimTy] tidyNPat lit lit_ty default_pat - | lit_ty == intTy = ConPat intDataCon lit_ty [] [] [LitPat (mk_int lit) intPrimTy] - | lit_ty == floatTy = ConPat floatDataCon lit_ty [] [] [LitPat (mk_float lit) floatPrimTy] - | lit_ty == doubleTy = ConPat doubleDataCon lit_ty [] [] [LitPat (mk_double lit) doublePrimTy] + | isIntTy lit_ty = mkPrefixConPat intDataCon [LitPat (mk_int lit)] lit_ty + | isFloatTy lit_ty = mkPrefixConPat floatDataCon [LitPat (mk_float lit)] lit_ty + | isDoubleTy lit_ty = mkPrefixConPat doubleDataCon [LitPat (mk_double lit)] lit_ty | otherwise = default_pat where @@ -145,7 +143,7 @@ selectMatchVar :: TypecheckedPat -> DsM Id selectMatchVar (VarPat var) = returnDs var selectMatchVar (AsPat var pat) = returnDs var selectMatchVar (LazyPat pat) = selectMatchVar pat -selectMatchVar other_pat = newSysLocalDs (outPatType other_pat) -- OK, better make up one... +selectMatchVar other_pat = newSysLocalDs (hsPatType other_pat) -- OK, better make up one... \end{code} @@ -252,7 +250,7 @@ mkCoPrimCaseMatchResult var match_alts where mk_case fail = mapDs (mk_alt fail) match_alts `thenDs` \ alts -> - returnDs (Case (Var var) var (alts ++ [(DEFAULT, [], fail)])) + returnDs (Case (Var var) var ((DEFAULT, [], fail) : alts)) mk_alt fail (lit, MatchResult _ body_fn) = body_fn fail `thenDs` \ body -> returnDs (LitAlt lit, [], body) @@ -264,28 +262,27 @@ mkCoAlgCaseMatchResult :: Id -- Scrutinee mkCoAlgCaseMatchResult var match_alts | isNewTyCon tycon -- Newtype case; use a let - = ASSERT( newtype_sanity ) - mkCoLetsMatchResult [coercion_bind] match_result + = ASSERT( null (tail match_alts) && null (tail arg_ids) ) + mkCoLetsMatchResult [NonRec arg_id newtype_rhs] match_result + + | isPArrFakeAlts match_alts -- Sugared parallel array; use a literal case + = MatchResult CanFail mk_parrCase | otherwise -- Datatype case; use a case = MatchResult fail_flag mk_case where -- Common stuff scrut_ty = idType var - (tycon, _, _) = splitAlgTyConApp scrut_ty + tycon = tcTyConAppTyCon scrut_ty -- Newtypes must be opaque here -- Stuff for newtype (_, arg_ids, match_result) = head match_alts - arg_id = head arg_ids - coercion_bind = NonRec arg_id (Note (Coerce (idType arg_id) - scrut_ty) - (Var var)) - newtype_sanity = null (tail match_alts) && null (tail arg_ids) - + arg_id = head arg_ids + newtype_rhs = mkNewTypeBody tycon (idType arg_id) (Var var) + -- Stuff for data types - data_cons = tyConDataCons tycon - - match_results = [match_result | (_,_,match_result) <- match_alts] + data_cons = tyConDataCons tycon + match_results = [match_result | (_,_,match_result) <- match_alts] fail_flag | exhaustive_case = foldr1 orFail [can_it_fail | MatchResult can_it_fail _ <- match_results] @@ -294,15 +291,12 @@ mkCoAlgCaseMatchResult var match_alts wild_var = mkWildId (idType var) mk_case fail = mapDs (mk_alt fail) match_alts `thenDs` \ alts -> - returnDs (Case (Var var) wild_var (alts ++ mk_default fail)) + returnDs (Case (Var var) wild_var (mk_default fail ++ alts)) mk_alt fail (con, args, MatchResult _ body_fn) - = body_fn fail `thenDs` \ body -> - getUniquesDs `thenDs` \ us -> - let - (binds, real_args) = rebuildConArgs args (dataConStrictMarks con) us - in - returnDs (DataAlt con, real_args, mkDsLets binds body) + = body_fn fail `thenDs` \ body -> + getUniquesDs `thenDs` \ us -> + returnDs (mkReboxingAlt us con args body) mk_default fail | exhaustive_case = [] | otherwise = [(DEFAULT, [], fail)] @@ -310,6 +304,71 @@ mkCoAlgCaseMatchResult var match_alts un_mentioned_constructors = mkUniqSet data_cons `minusUniqSet` mkUniqSet [ con | (con, _, _) <- match_alts] exhaustive_case = isEmptyUniqSet un_mentioned_constructors + + -- Stuff for parallel arrays + -- + -- * the following is to desugar cases over fake constructors for + -- parallel arrays, which are introduced by `tidy1' in the `PArrPat' + -- case + -- + -- Concerning `isPArrFakeAlts': + -- + -- * it is *not* sufficient to just check the type of the type + -- constructor, as we have to be careful not to confuse the real + -- representation of parallel arrays with the fake constructors; + -- moreover, a list of alternatives must not mix fake and real + -- constructors (this is checked earlier on) + -- + -- FIXME: We actually go through the whole list and make sure that + -- either all or none of the constructors are fake parallel + -- array constructors. This is to spot equations that mix fake + -- constructors with the real representation defined in + -- `PrelPArr'. It would be nicer to spot this situation + -- earlier and raise a proper error message, but it can really + -- only happen in `PrelPArr' anyway. + -- + isPArrFakeAlts [(dcon, _, _)] = isPArrFakeCon dcon + isPArrFakeAlts ((dcon, _, _):alts) = + case (isPArrFakeCon dcon, isPArrFakeAlts alts) of + (True , True ) -> True + (False, False) -> False + _ -> + panic "DsUtils: You may not mix `[:...:]' with `PArr' patterns" + -- + mk_parrCase fail = + dsLookupGlobalId lengthPName `thenDs` \lengthP -> + unboxAlt `thenDs` \alt -> + returnDs (Case (len lengthP) (mkWildId intTy) [alt]) + where + elemTy = case splitTyConApp (idType var) of + (_, [elemTy]) -> elemTy + _ -> panic panicMsg + panicMsg = "DsUtils.mkCoAlgCaseMatchResult: not a parallel array?" + len lengthP = mkApps (Var lengthP) [Type elemTy, Var var] + -- + unboxAlt = + newSysLocalDs intPrimTy `thenDs` \l -> + dsLookupGlobalId indexPName `thenDs` \indexP -> + mapDs (mkAlt indexP) match_alts `thenDs` \alts -> + returnDs (DataAlt intDataCon, [l], (Case (Var l) wild (dft : alts))) + where + wild = mkWildId intPrimTy + dft = (DEFAULT, [], fail) + -- + -- each alternative matches one array length (corresponding to one + -- fake array constructor), so the match is on a literal; each + -- alternative's body is extended by a local binding for each + -- constructor argument, which are bound to array elements starting + -- with the first + -- + mkAlt indexP (con, args, MatchResult _ bodyFun) = + bodyFun fail `thenDs` \body -> + returnDs (LitAlt lit, [], mkDsLets binds body) + where + lit = MachInt $ toInteger (dataConSourceArity con) + binds = [NonRec arg (indexExpr i) | (i, arg) <- zip [1..] args] + -- + indexExpr i = mkApps (Var indexP) [Type elemTy, Var var, mkIntExpr i] \end{code} @@ -329,8 +388,8 @@ mkErrorAppDs err_id ty msg = getSrcLocDs `thenDs` \ src_loc -> let full_msg = showSDoc (hcat [ppr src_loc, text "|", text msg]) + core_msg = Lit (MachStr (mkFastString (stringToUtf8 full_msg))) in - mkStringLit full_msg `thenDs` \ core_msg -> returnDs (mkApps (Var err_id) [Type ty, core_msg]) \end{code} @@ -342,8 +401,16 @@ mkErrorAppDs err_id ty msg %************************************************************************ \begin{code} -mkIntegerLit :: Integer -> DsM CoreExpr -mkIntegerLit i +mkCharExpr :: Int -> CoreExpr -- Returns C# c :: Int +mkIntExpr :: Integer -> CoreExpr -- Returns I# i :: Int +mkIntegerExpr :: Integer -> DsM CoreExpr -- Result :: Integer +mkStringLit :: String -> DsM CoreExpr -- Result :: String +mkStringLitFS :: FastString -> DsM CoreExpr -- Result :: String + +mkIntExpr i = mkConApp intDataCon [mkIntLit i] +mkCharExpr c = mkConApp charDataCon [mkLit (MachChar c)] + +mkIntegerExpr i | inIntRange i -- Small enough, so start from an Int = returnDs (mkSmallIntegerLit i) @@ -352,8 +419,8 @@ mkIntegerLit i -- integral literals. This improves constant folding. | otherwise -- Big, so start from a string - = dsLookupGlobalValue plusIntegerName `thenDs` \ plus_id -> - dsLookupGlobalValue timesIntegerName `thenDs` \ times_id -> + = dsLookupGlobalId plusIntegerName `thenDs` \ plus_id -> + dsLookupGlobalId timesIntegerName `thenDs` \ times_id -> let plus a b = Var plus_id `App` a `App` b times a b = Var times_id `App` a `App` b @@ -373,30 +440,28 @@ mkIntegerLit i mkSmallIntegerLit i = mkConApp smallIntegerDataCon [mkIntLit i] -mkStringLit :: String -> DsM CoreExpr -mkStringLit str = mkStringLitFS (_PK_ str) +mkStringLit str = mkStringLitFS (mkFastString str) -mkStringLitFS :: FAST_STRING -> DsM CoreExpr mkStringLitFS str - | _NULL_ str + | nullFastString str = returnDs (mkNilExpr charTy) - | _LENGTH_ str == 1 + | lengthFS str == 1 = let - the_char = mkConApp charDataCon [mkLit (MachChar (_HEAD_INT_ str))] + the_char = mkCharExpr (headIntFS str) in returnDs (mkConsExpr charTy the_char (mkNilExpr charTy)) - | all safeChar chars - = dsLookupGlobalValue unpackCStringName `thenDs` \ unpack_id -> + | all safeChar int_chars + = dsLookupGlobalId unpackCStringName `thenDs` \ unpack_id -> returnDs (App (Var unpack_id) (Lit (MachStr str))) | otherwise - = dsLookupGlobalValue unpackCStringUtf8Name `thenDs` \ unpack_id -> - returnDs (App (Var unpack_id) (Lit (MachStr (_PK_ (stringToUtf8 chars))))) + = dsLookupGlobalId unpackCStringUtf8Name `thenDs` \ unpack_id -> + returnDs (App (Var unpack_id) (Lit (MachStr (mkFastString (intsToUtf8 int_chars))))) where - chars = _UNPK_INT_ str + int_chars = unpackIntFS str safeChar c = c >= 1 && c <= 0xFF \end{code} @@ -432,59 +497,72 @@ mkSelectorBinds (VarPat v) val_expr = returnDs [(v, val_expr)] mkSelectorBinds pat val_expr - | length binders == 1 || is_simple_pat pat - = newSysLocalDs (exprType val_expr) `thenDs` \ val_var -> - - -- For the error message we don't use mkErrorAppDs to avoid - -- duplicating the string literal each time - newSysLocalDs stringTy `thenDs` \ msg_var -> - getSrcLocDs `thenDs` \ src_loc -> - let - full_msg = showSDoc (hcat [ppr src_loc, text "|", ppr pat]) - in - mkStringLit full_msg `thenDs` \ core_msg -> - mapDs (mk_bind val_var msg_var) binders `thenDs` \ binds -> + | isSingleton binders || is_simple_pat pat + = -- Given p = e, where p binds x,y + -- we are going to make + -- v = p (where v is fresh) + -- x = case v of p -> x + -- y = case v of p -> x + + -- Make up 'v' + -- NB: give it the type of *pattern* p, not the type of the *rhs* e. + -- This does not matter after desugaring, but there's a subtle + -- issue with implicit parameters. Consider + -- (x,y) = ?i + -- Then, ?i is given type {?i :: Int}, a SourceType, which is opaque + -- to the desugarer. (Why opaque? Because newtypes have to be. Why + -- does it get that type? So that when we abstract over it we get the + -- right top-level type (?i::Int) => ...) + -- + -- So to get the type of 'v', use the pattern not the rhs. Often more + -- efficient too. + newSysLocalDs (hsPatType pat) `thenDs` \ val_var -> + + -- For the error message we make one error-app, to avoid duplication. + -- But we need it at different types... so we use coerce for that + mkErrorAppDs iRREFUT_PAT_ERROR_ID + unitTy (showSDoc (ppr pat)) `thenDs` \ err_expr -> + newSysLocalDs unitTy `thenDs` \ err_var -> + mapDs (mk_bind val_var err_var) binders `thenDs` \ binds -> returnDs ( (val_var, val_expr) : - (msg_var, core_msg) : + (err_var, err_expr) : binds ) | otherwise - = mkErrorAppDs iRREFUT_PAT_ERROR_ID tuple_ty (showSDoc (ppr pat)) - `thenDs` \ error_expr -> - matchSimply val_expr PatBindRhs pat local_tuple error_expr - `thenDs` \ tuple_expr -> - newSysLocalDs tuple_ty - `thenDs` \ tuple_var -> + = mkErrorAppDs iRREFUT_PAT_ERROR_ID + tuple_ty (showSDoc (ppr pat)) `thenDs` \ error_expr -> + matchSimply val_expr PatBindRhs pat local_tuple error_expr `thenDs` \ tuple_expr -> + newSysLocalDs tuple_ty `thenDs` \ tuple_var -> let - mk_tup_bind binder = - (binder, mkTupleSelector binders binder tuple_var (Var tuple_var)) + mk_tup_bind binder + = (binder, mkTupleSelector binders binder tuple_var (Var tuple_var)) in returnDs ( (tuple_var, tuple_expr) : map mk_tup_bind binders ) where - binders = collectTypedPatBinders pat + binders = collectPatBinders pat local_tuple = mkTupleExpr binders tuple_ty = exprType local_tuple - mk_bind scrut_var msg_var bndr_var - -- (mk_bind sv bv) generates - -- bv = case sv of { pat -> bv; other -> error-msg } + mk_bind scrut_var err_var bndr_var + -- (mk_bind sv err_var) generates + -- bv = case sv of { pat -> bv; other -> coerce (type-of-bv) err_var } -- Remember, pat binds bv = matchSimply (Var scrut_var) PatBindRhs pat (Var bndr_var) error_expr `thenDs` \ rhs_expr -> returnDs (bndr_var, rhs_expr) where - binder_ty = idType bndr_var - error_expr = mkApps (Var iRREFUT_PAT_ERROR_ID) [Type binder_ty, Var msg_var] + error_expr = mkCoerce (idType bndr_var) (Var err_var) - is_simple_pat (TuplePat ps Boxed) = all is_triv_pat ps - is_simple_pat (ConPat _ _ _ _ ps) = all is_triv_pat ps - is_simple_pat (VarPat _) = True - is_simple_pat (RecPat _ _ _ _ ps) = and [is_triv_pat p | (_,p,_) <- ps] - is_simple_pat other = False + is_simple_pat (TuplePat ps Boxed) = all is_triv_pat ps + is_simple_pat (ConPatOut _ ps _ _ _) = all is_triv_pat (hsConArgs ps) + is_simple_pat (VarPat _) = True + is_simple_pat (ParPat p) = is_simple_pat p + is_simple_pat other = False is_triv_pat (VarPat v) = True is_triv_pat (WildPat _) = True + is_triv_pat (ParPat p) = is_triv_pat p is_triv_pat other = False \end{code} @@ -495,10 +573,21 @@ has only one element, it is the identity function. \begin{code} mkTupleExpr :: [Id] -> CoreExpr +{- This code has been replaced by mkCoreTup below mkTupleExpr [] = Var unitDataConId mkTupleExpr [id] = Var id mkTupleExpr ids = mkConApp (tupleCon Boxed (length ids)) - (map (Type . idType) ids ++ [ Var i | i <- ids ]) + (map (Type . idType) ids ++ [ Var i | i <-ids]) +-} + +mkTupleExpr ids = mkCoreTup(map Var ids) + +mkCoreTup :: [CoreExpr] -> CoreExpr +mkCoreTup [] = Var unitDataConId +mkCoreTup [c] = c +mkCoreTup cs = mkConApp (tupleCon Boxed (length cs)) + (map (Type . exprType) cs ++ cs) + \end{code} @@ -523,7 +612,7 @@ mkTupleSelector [var] should_be_the_same_var scrut_var scrut scrut mkTupleSelector vars the_var scrut_var scrut - = ASSERT( not (null vars) ) + = ASSERT( notNull vars ) Case scrut scrut_var [(DataAlt (tupleCon Boxed (length vars)), vars, Var the_var)] \end{code} @@ -539,10 +628,14 @@ interact well with rules. \begin{code} mkNilExpr :: Type -> CoreExpr -mkNilExpr ty = App (Var (dataConId nilDataCon)) (Type ty) +mkNilExpr ty = mkConApp nilDataCon [Type ty] mkConsExpr :: Type -> CoreExpr -> CoreExpr -> CoreExpr -mkConsExpr ty hd tl = mkApps (Var (dataConId consDataCon)) [Type ty, hd, tl] +mkConsExpr ty hd tl = mkConApp consDataCon [Type ty, hd, tl] + +mkListExpr :: Type -> [CoreExpr] -> CoreExpr +mkListExpr ty xs = foldr (mkConsExpr ty) (mkNilExpr ty) xs + \end{code} @@ -621,4 +714,3 @@ mkFailurePair expr \end{code} -