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,
68 -- Note that we flatten binds at the top level:
69 -- every module is just a single recursive bag of declarations.
70 -- Rationale: since modules can be mutually recursive,
71 -- there's not much reason to preserve dependency info within a module.
72 = C.Module mname tdefs (case flattenBinds binds of
73 -- check for empty list so we don't create an
76 bs -> [(runCoreM (make_vdef True
79 mname = make_mid this_mod
80 tdefs = foldr collect_tdefs [] tycons
82 collect_tdefs :: TyCon -> [C.Tdef] -> [C.Tdef]
83 collect_tdefs tcon tdefs
84 | isAlgTyCon tcon = tdef: tdefs
86 tdef | isNewTyCon tcon =
87 C.Newtype (qtc tcon) (map make_tbind tyvars)
88 (case newTyConCo_maybe tcon of
91 make_kind (mkCoKind l r))
92 where (vs,l,r) = coercionAxiom co
93 Nothing -> pprPanic ("MkExternalCore: newtype tcon\
94 should have a coercion: ") (ppr tcon))
97 C.Data (qtc tcon) (map make_tbind tyvars)
98 (map make_cdef (tyConDataCons tcon))
99 where repclause | isRecursiveTyCon tcon || isOpenTyCon tcon= Nothing
100 | otherwise = Just (make_ty (snd (newTyConRhs tcon)))
101 tyvars = tyConTyVars tcon
103 case isCoercionTyCon_maybe co of
104 -- See Note [Newtype coercions] in
106 Just (arity,coKindFun) | (l,r) <- (coKindFun $ map mkTyVarTy vs) ->
107 -- Here we eta-expand the newtype coercion,
108 -- which makes the ext-core typechecker somewhat simpler.
109 (tyvars,mkAppTys l extraVs,mkAppTys r extraVs)
110 where (vs, extraVs) = (take arity tyvars,
111 map mkTyVarTy $ drop arity tyvars)
112 Nothing -> pprPanic "MkExternalCore: coercion tcon lacks a kind fun"
115 collect_tdefs _ tdefs = tdefs
117 qtc :: TyCon -> C.Qual C.Tcon
118 qtc = make_con_qid . tyConName
121 make_cdef :: DataCon -> C.Cdef
122 make_cdef dcon = C.Constr dcon_name existentials tys
124 dcon_name = make_qid False False (dataConName dcon)
125 existentials = map make_tbind ex_tyvars
126 ex_tyvars = dataConExTyVars dcon
127 tys = map make_ty (dataConRepArgTys dcon)
129 make_tbind :: TyVar -> C.Tbind
130 make_tbind tv = (make_var_id (tyVarName tv), make_kind (tyVarKind tv))
132 make_vbind :: Var -> C.Vbind
133 make_vbind v = (make_var_id (Var.varName v), make_ty (idType v))
135 make_vdef :: Bool -> CoreBind -> CoreM C.Vdefg
136 make_vdef topLevel b =
138 NonRec v e -> f (v,e) >>= (return . C.Nonrec)
139 Rec ves -> mapM f ves >>= (return . C.Rec)
141 f :: (CoreBndr,CoreExpr) -> CoreM C.Vdef
143 localN <- isALocal vName
144 let local = not topLevel || localN
146 -- use local flag to determine where to add the module name
147 return (local, make_qid local True vName, make_ty (idType v),rhs)
148 where vName = Var.varName v
150 make_exp :: CoreExpr -> CoreM C.Exp
151 make_exp (Var v) = do
152 let vName = Var.varName v
153 isLocal <- isALocal vName
155 case globalIdDetails v of
156 FCallId (CCall (CCallSpec (StaticTarget nm) callconv _))
157 -> C.External (unpackFS nm) (showSDoc (ppr callconv)) (make_ty (idType v))
158 FCallId (CCall (CCallSpec DynamicTarget callconv _))
159 -> C.DynExternal (showSDoc (ppr callconv)) (make_ty (idType v))
161 -> pprPanic "MkExternalCore died: can't handle non-{static,dynamic}-C foreign call"
163 -- Constructors are always exported, so make sure to declare them
164 -- with qualified names
165 DataConWorkId _ -> C.Var (make_var_qid False vName)
166 DataConWrapId _ -> C.Var (make_var_qid False vName)
167 _ -> C.Var (make_var_qid isLocal vName)
168 make_exp (Lit (MachLabel s _)) = return $ C.Label (unpackFS s)
169 make_exp (Lit l) = return $ C.Lit (make_lit l)
170 make_exp (App e (Type t)) = make_exp e >>= (\ b -> return $ C.Appt b (make_ty t))
171 make_exp (App e1 e2) = do
174 return $ C.App rator rand
175 make_exp (Lam v e) | isTyVar v = make_exp e >>= (\ b ->
176 return $ C.Lam (C.Tb (make_tbind v)) b)
177 make_exp (Lam v e) | otherwise = make_exp e >>= (\ b ->
178 return $ C.Lam (C.Vb (make_vbind v)) b)
179 make_exp (Cast e co) = make_exp e >>= (\ b -> return $ C.Cast b (make_ty co))
180 make_exp (Let b e) = do
181 vd <- make_vdef False b
183 return $ C.Let vd body
184 make_exp (Case e v ty alts) = do
186 newAlts <- mapM make_alt alts
187 return $ C.Case scrut (make_vbind v) (make_ty ty) newAlts
188 make_exp (Note (SCC _) e) = make_exp e >>= (return . C.Note "SCC") -- temporary
189 make_exp (Note (CoreNote s) e) = make_exp e >>= (return . C.Note s) -- hdaume: core annotations
190 make_exp (Note InlineMe e) = make_exp e >>= (return . C.Note "InlineMe")
191 make_exp _ = error "MkExternalCore died: make_exp"
193 make_alt :: CoreAlt -> CoreM C.Alt
194 make_alt (DataAlt dcon, vs, e) = do
196 return $ C.Acon (make_con_qid (dataConName dcon))
200 where (tbs,vbs) = span isTyVar vs
201 make_alt (LitAlt l,_,e) = make_exp e >>= (return . (C.Alit (make_lit l)))
202 make_alt (DEFAULT,[],e) = make_exp e >>= (return . C.Adefault)
203 -- This should never happen, as the DEFAULT alternative binds no variables,
204 -- but we might as well check for it:
205 make_alt a@(DEFAULT,_ ,_) = pprPanic ("MkExternalCore: make_alt: DEFAULT "
206 ++ "alternative had a non-empty var list") (ppr a)
209 make_lit :: Literal -> C.Lit
212 -- Note that we need to check whether the character is "big".
213 -- External Core only allows character literals up to '\xff'.
214 MachChar i | i <= chr 0xff -> C.Lchar i t
215 -- For a character bigger than 0xff, we represent it in ext-core
216 -- as an int lit with a char type.
217 MachChar i -> C.Lint (fromIntegral $ ord i) t
218 MachStr s -> C.Lstring (unpackFS s) t
219 MachNullAddr -> C.Lint 0 t
220 MachInt i -> C.Lint i t
221 MachInt64 i -> C.Lint i t
222 MachWord i -> C.Lint i t
223 MachWord64 i -> C.Lint i t
224 MachFloat r -> C.Lrational r t
225 MachDouble r -> C.Lrational r t
226 _ -> error "MkExternalCore died: make_lit"
228 t = make_ty (literalType l)
230 -- Expand type synonyms, then convert.
231 make_ty :: Type -> C.Ty -- Be sure to expand types recursively!
232 -- example: FilePath ~> String ~> [Char]
233 make_ty t | Just expanded <- tcView t = make_ty expanded
234 make_ty t = make_ty' t
236 -- note calls to make_ty so as to expand types recursively
237 make_ty' :: Type -> C.Ty
238 make_ty' (TyVarTy tv) = C.Tvar (make_var_id (tyVarName tv))
239 make_ty' (AppTy t1 t2) = C.Tapp (make_ty t1) (make_ty t2)
240 make_ty' (FunTy t1 t2) = make_ty (TyConApp funTyCon [t1,t2])
241 make_ty' (ForAllTy tv t) = C.Tforall (make_tbind tv) (make_ty t)
242 make_ty' (TyConApp tc ts) = foldl C.Tapp (C.Tcon (qtc tc))
244 -- Newtypes are treated just like any other type constructor; not expanded
245 -- Reason: predTypeRep does substitution and, while substitution deals
246 -- correctly with name capture, it's only correct if you see the uniques!
247 -- If you just see occurrence names, name capture may occur.
248 -- Example: newtype A a = A (forall b. b -> a)
249 -- test :: forall q b. q -> A b
250 -- test _ = undefined
251 -- Here the 'a' gets substituted by 'b', which is captured.
252 -- Another solution would be to expand newtypes before tidying; but that would
253 -- expose the representation in interface files, which definitely isn't right.
254 -- Maybe CoreTidy should know whether to expand newtypes or not?
256 make_ty' (PredTy p) = make_ty (predTypeRep p)
260 make_kind :: Kind -> C.Kind
261 make_kind (PredTy p) | isEqPred p = C.Keq (make_ty t1) (make_ty t2)
262 where (t1, t2) = getEqPredTys p
263 make_kind (FunTy k1 k2) = C.Karrow (make_kind k1) (make_kind k2)
265 | isLiftedTypeKind k = C.Klifted
266 | isUnliftedTypeKind k = C.Kunlifted
267 | isOpenTypeKind k = C.Kopen
268 make_kind _ = error "MkExternalCore died: make_kind"
272 make_id :: Bool -> Name -> C.Id
273 -- include uniques for internal names in order to avoid name shadowing
274 make_id _is_var nm = ((occNameString . nameOccName) nm)
275 ++ (if isInternalName nm then (show . nameUnique) nm else "")
277 make_var_id :: Name -> C.Id
278 make_var_id = make_id True
280 -- It's important to encode the module name here, because in External Core,
281 -- base:GHC.Base => base:GHCziBase
282 -- We don't do this in pprExternalCore because we
283 -- *do* want to keep the package name (we don't want baseZCGHCziBase,
284 -- because that would just be ugly.)
286 -- We encode the package name as well.
287 make_mid :: Module -> C.Id
288 -- Super ugly code, but I can't find anything else that does quite what I
289 -- want (encodes the hierarchical module name without encoding the colon
290 -- that separates the package name from it.)
291 make_mid m = showSDoc $
292 (text $ zEncodeString $ packageIdString $ modulePackageId m)
294 <> (pprEncoded $ pprModuleName $ moduleName m)
295 where pprEncoded = pprCode CStyle
297 make_qid :: Bool -> Bool -> Name -> C.Qual C.Id
298 make_qid force_unqual is_var n = (mname,make_id is_var n)
300 case nameModule_maybe n of
301 Just m | not force_unqual -> make_mid m
304 make_var_qid :: Bool -> Name -> C.Qual C.Id
305 make_var_qid force_unqual = make_qid force_unqual True
307 make_con_qid :: Name -> C.Qual C.Id
308 make_con_qid = make_qid False False
311 isALocal :: Name -> CoreM Bool
314 return $ case nameModule_maybe vName of
315 -- Not sure whether isInternalName corresponds to "local"ness
316 -- in the External Core sense; need to re-read the spec.
317 Just m | m == modName -> isInternalName vName