2 % (c) The University of Glasgow 2001-2006
5 module MkExternalCore (
9 #include "HsVersions.h"
11 import qualified ExternalCore as C
18 import PprExternalCore () -- Instances
35 emitExternalCore :: DynFlags -> CgGuts -> IO ()
36 emitExternalCore dflags cg_guts
37 | opt_EmitExternalCore
38 = (do handle <- openFile corename WriteMode
39 hPutStrLn handle (show (mkExternalCore cg_guts))
41 `catch` (\_ -> pprPanic "Failed to open or write external core output file"
43 where corename = extCoreName dflags
48 -- Reinventing the Reader monad; whee.
49 newtype CoreM a = CoreM (CoreState -> (CoreState, a))
50 type CoreState = Module
51 instance Monad CoreM where
52 (CoreM m) >>= f = CoreM (\ s -> case m s of
55 return x = CoreM (\ s -> (s, x))
56 runCoreM :: CoreM a -> CoreState -> a
57 runCoreM (CoreM f) s = snd $ f s
58 ask :: CoreM CoreState
59 ask = CoreM (\ s -> (s,s))
61 mkExternalCore :: CgGuts -> C.Module
62 -- The ModGuts has been tidied, but the implicit bindings have
63 -- not been injected, so we have to add them manually here
64 -- We don't include the strange data-con *workers* because they are
65 -- implicit in the data type declaration itself
66 mkExternalCore (CgGuts {cg_module=this_mod, cg_tycons = tycons, cg_binds = binds})
67 = (C.Module mname tdefs (runCoreM (mapM (make_vdef True) binds)
70 mname = make_mid this_mod
71 tdefs = foldr collect_tdefs [] tycons
73 collect_tdefs :: TyCon -> [C.Tdef] -> [C.Tdef]
74 collect_tdefs tcon tdefs
75 | isAlgTyCon tcon = tdef: tdefs
77 tdef | isNewTyCon tcon =
78 C.Newtype (qtc tcon) (map make_tbind tyvars)
79 (case newTyConCo_maybe tcon of
82 make_kind (mkCoKind l r))
83 where (vs,l,r) = coercionAxiom co
84 Nothing -> pprPanic ("MkExternalCore: newtype tcon\
85 should have a coercion: ") (ppr tcon))
88 C.Data (qtc tcon) (map make_tbind tyvars)
89 (map make_cdef (tyConDataCons tcon))
90 where repclause | isRecursiveTyCon tcon || isOpenTyCon tcon= Nothing
91 | otherwise = Just (make_ty (snd (newTyConRhs tcon)))
92 tyvars = tyConTyVars tcon
94 case isCoercionTyCon_maybe co of
95 -- See Note [Newtype coercions] in
97 Just (arity,coKindFun) | (l,r) <- (coKindFun $ map mkTyVarTy vs) ->
98 (vs,l,r) where vs = take arity tyvars
99 Nothing -> pprPanic "MkExternalCore: coercion tcon lacks a kind fun"
102 collect_tdefs _ tdefs = tdefs
104 qtc :: TyCon -> C.Qual C.Tcon
105 qtc = make_con_qid . tyConName
108 make_cdef :: DataCon -> C.Cdef
109 make_cdef dcon = C.Constr dcon_name existentials tys
111 dcon_name = make_qid False False (dataConName dcon)
112 existentials = map make_tbind ex_tyvars
113 ex_tyvars = dataConExTyVars dcon
114 tys = map make_ty (dataConRepArgTys dcon)
116 make_tbind :: TyVar -> C.Tbind
117 make_tbind tv = (make_var_id (tyVarName tv), make_kind (tyVarKind tv))
119 make_vbind :: Var -> C.Vbind
120 make_vbind v = (make_var_id (Var.varName v), make_ty (idType v))
122 make_vdef :: Bool -> CoreBind -> CoreM C.Vdefg
123 make_vdef topLevel b =
125 NonRec v e -> f (v,e) >>= (return . C.Nonrec)
126 Rec ves -> mapM f ves >>= (return . C.Rec)
128 f :: (CoreBndr,CoreExpr) -> CoreM C.Vdef
130 localN <- isALocal vName
131 let local = not topLevel || localN
133 -- use local flag to determine where to add the module name
134 return (local, make_qid local True vName, make_ty (idType v),rhs)
135 where vName = Var.varName v
137 make_exp :: CoreExpr -> CoreM C.Exp
138 make_exp (Var v) = do
139 let vName = Var.varName v
140 isLocal <- isALocal vName
142 case globalIdDetails v of
143 FCallId (CCall (CCallSpec (StaticTarget nm) callconv _))
144 -> C.External (unpackFS nm) (showSDoc (ppr callconv)) (make_ty (idType v))
145 FCallId (CCall (CCallSpec DynamicTarget callconv _))
146 -> C.DynExternal (showSDoc (ppr callconv)) (make_ty (idType v))
148 -> pprPanic "MkExternalCore died: can't handle non-{static,dynamic}-C foreign call"
150 -- Constructors are always exported, so make sure to declare them
151 -- with qualified names
152 DataConWorkId _ -> C.Var (make_var_qid False vName)
153 DataConWrapId _ -> C.Var (make_var_qid False vName)
154 _ -> C.Var (make_var_qid isLocal vName)
155 make_exp (Lit (MachLabel s _)) = return $ C.Label (unpackFS s)
156 make_exp (Lit l) = return $ C.Lit (make_lit l)
157 make_exp (App e (Type t)) = make_exp e >>= (\ b -> return $ C.Appt b (make_ty t))
158 make_exp (App e1 e2) = do
161 return $ C.App rator rand
162 make_exp (Lam v e) | isTyVar v = make_exp e >>= (\ b ->
163 return $ C.Lam (C.Tb (make_tbind v)) b)
164 make_exp (Lam v e) | otherwise = make_exp e >>= (\ b ->
165 return $ C.Lam (C.Vb (make_vbind v)) b)
166 make_exp (Cast e co) = make_exp e >>= (\ b -> return $ C.Cast b (make_ty co))
167 make_exp (Let b e) = do
168 vd <- make_vdef False b
170 return $ C.Let vd body
171 make_exp (Case e v ty alts) = do
173 newAlts <- mapM make_alt alts
174 return $ C.Case scrut (make_vbind v) (make_ty ty) newAlts
175 make_exp (Note (SCC _) e) = make_exp e >>= (return . C.Note "SCC") -- temporary
176 make_exp (Note (CoreNote s) e) = make_exp e >>= (return . C.Note s) -- hdaume: core annotations
177 make_exp (Note InlineMe e) = make_exp e >>= (return . C.Note "InlineMe")
178 make_exp _ = error "MkExternalCore died: make_exp"
180 make_alt :: CoreAlt -> CoreM C.Alt
181 make_alt (DataAlt dcon, vs, e) = do
183 return $ C.Acon (make_con_qid (dataConName dcon))
187 where (tbs,vbs) = span isTyVar vs
188 make_alt (LitAlt l,_,e) = make_exp e >>= (return . (C.Alit (make_lit l)))
189 make_alt (DEFAULT,[],e) = make_exp e >>= (return . C.Adefault)
190 -- This should never happen, as the DEFAULT alternative binds no variables,
191 -- but we might as well check for it:
192 make_alt a@(DEFAULT,_ ,_) = pprPanic ("MkExternalCore: make_alt: DEFAULT "
193 ++ "alternative had a non-empty var list") (ppr a)
196 make_lit :: Literal -> C.Lit
199 -- Note that we need to check whether the character is "big".
200 -- External Core only allows character literals up to '\xff'.
201 MachChar i | i <= chr 0xff -> C.Lchar i t
202 -- For a character bigger than 0xff, we represent it in ext-core
203 -- as an int lit with a char type.
204 MachChar i -> C.Lint (fromIntegral $ ord i) t
205 MachStr s -> C.Lstring (unpackFS s) t
206 MachNullAddr -> C.Lint 0 t
207 MachInt i -> C.Lint i t
208 MachInt64 i -> C.Lint i t
209 MachWord i -> C.Lint i t
210 MachWord64 i -> C.Lint i t
211 MachFloat r -> C.Lrational r t
212 MachDouble r -> C.Lrational r t
213 _ -> error "MkExternalCore died: make_lit"
215 t = make_ty (literalType l)
217 -- Expand type synonyms, then convert.
218 make_ty :: Type -> C.Ty -- Be sure to expand types recursively!
219 -- example: FilePath ~> String ~> [Char]
220 make_ty t | Just expanded <- tcView t = make_ty expanded
221 make_ty t = make_ty' t
223 -- note calls to make_ty so as to expand types recursively
224 make_ty' :: Type -> C.Ty
225 make_ty' (TyVarTy tv) = C.Tvar (make_var_id (tyVarName tv))
226 make_ty' (AppTy t1 t2) = C.Tapp (make_ty t1) (make_ty t2)
227 make_ty' (FunTy t1 t2) = make_ty (TyConApp funTyCon [t1,t2])
228 make_ty' (ForAllTy tv t) = C.Tforall (make_tbind tv) (make_ty t)
229 make_ty' (TyConApp tc ts) = foldl C.Tapp (C.Tcon (qtc tc))
231 -- Newtypes are treated just like any other type constructor; not expanded
232 -- Reason: predTypeRep does substitution and, while substitution deals
233 -- correctly with name capture, it's only correct if you see the uniques!
234 -- If you just see occurrence names, name capture may occur.
235 -- Example: newtype A a = A (forall b. b -> a)
236 -- test :: forall q b. q -> A b
237 -- test _ = undefined
238 -- Here the 'a' gets substituted by 'b', which is captured.
239 -- Another solution would be to expand newtypes before tidying; but that would
240 -- expose the representation in interface files, which definitely isn't right.
241 -- Maybe CoreTidy should know whether to expand newtypes or not?
243 make_ty' (PredTy p) = make_ty (predTypeRep p)
247 make_kind :: Kind -> C.Kind
248 make_kind (PredTy p) | isEqPred p = C.Keq (make_ty t1) (make_ty t2)
249 where (t1, t2) = getEqPredTys p
250 make_kind (FunTy k1 k2) = C.Karrow (make_kind k1) (make_kind k2)
252 | isLiftedTypeKind k = C.Klifted
253 | isUnliftedTypeKind k = C.Kunlifted
254 | isOpenTypeKind k = C.Kopen
255 make_kind _ = error "MkExternalCore died: make_kind"
259 make_id :: Bool -> Name -> C.Id
260 make_id _is_var nm = (occNameString . nameOccName) nm
262 make_var_id :: Name -> C.Id
263 make_var_id = make_id True
265 -- It's important to encode the module name here, because in External Core,
266 -- base:GHC.Base => base:GHCziBase
267 -- We don't do this in pprExternalCore because we
268 -- *do* want to keep the package name (we don't want baseZCGHCziBase,
269 -- because that would just be ugly.)
271 -- We encode the package name as well.
272 make_mid :: Module -> C.Id
273 -- Super ugly code, but I can't find anything else that does quite what I
274 -- want (encodes the hierarchical module name without encoding the colon
275 -- that separates the package name from it.)
276 make_mid m = showSDoc $
277 (text $ zEncodeString $ packageIdString $ modulePackageId m)
279 <> (pprEncoded $ pprModuleName $ moduleName m)
280 where pprEncoded = pprCode CStyle
282 make_qid :: Bool -> Bool -> Name -> C.Qual C.Id
283 make_qid force_unqual is_var n = (mname,make_id is_var n)
285 case nameModule_maybe n of
286 Just m | not force_unqual -> make_mid m
289 make_var_qid :: Bool -> Name -> C.Qual C.Id
290 make_var_qid force_unqual = make_qid force_unqual True
292 make_con_qid :: Name -> C.Qual C.Id
293 make_con_qid = make_qid False False
296 isALocal :: Name -> CoreM Bool
299 return $ case nameModule_maybe vName of
300 -- Not sure whether isInternalName corresponds to "local"ness
301 -- in the External Core sense; need to re-read the spec.
302 Just m | m == modName -> isInternalName vName