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 =
88 (case newTyConCo_maybe tcon of
90 Nothing -> pprPanic ("MkExternalCore: newtype tcon\
91 should have a coercion: ") (ppr tcon))
92 (map make_tbind tyvars)
93 (make_ty (snd (newTyConRhs tcon)))
95 C.Data (qtc tcon) (map make_tbind tyvars)
96 (map make_cdef (tyConDataCons tcon))
97 tyvars = tyConTyVars tcon
99 collect_tdefs _ tdefs = tdefs
101 qtc :: TyCon -> C.Qual C.Tcon
102 qtc = make_con_qid . tyConName
105 make_cdef :: DataCon -> C.Cdef
106 make_cdef dcon = C.Constr dcon_name existentials tys
108 dcon_name = make_qid False False (dataConName dcon)
109 existentials = map make_tbind ex_tyvars
110 ex_tyvars = dataConExTyVars dcon
111 tys = map make_ty (dataConRepArgTys dcon)
113 make_tbind :: TyVar -> C.Tbind
114 make_tbind tv = (make_var_id (tyVarName tv), make_kind (tyVarKind tv))
116 make_vbind :: Var -> C.Vbind
117 make_vbind v = (make_var_id (Var.varName v), make_ty (idType v))
119 make_vdef :: Bool -> CoreBind -> CoreM C.Vdefg
120 make_vdef topLevel b =
122 NonRec v e -> f (v,e) >>= (return . C.Nonrec)
123 Rec ves -> mapM f ves >>= (return . C.Rec)
125 f :: (CoreBndr,CoreExpr) -> CoreM C.Vdef
127 localN <- isALocal vName
128 let local = not topLevel || localN
130 -- use local flag to determine where to add the module name
131 return (local, make_qid local True vName, make_ty (idType v),rhs)
132 where vName = Var.varName v
134 make_exp :: CoreExpr -> CoreM C.Exp
135 make_exp (Var v) = do
136 let vName = Var.varName v
137 isLocal <- isALocal vName
139 case globalIdDetails v of
140 FCallId (CCall (CCallSpec (StaticTarget nm) callconv _))
141 -> C.External (unpackFS nm) (showSDoc (ppr callconv)) (make_ty (idType v))
142 FCallId (CCall (CCallSpec DynamicTarget callconv _))
143 -> C.DynExternal (showSDoc (ppr callconv)) (make_ty (idType v))
145 -> pprPanic "MkExternalCore died: can't handle non-{static,dynamic}-C foreign call"
147 -- Constructors are always exported, so make sure to declare them
148 -- with qualified names
149 DataConWorkId _ -> C.Var (make_var_qid False vName)
150 DataConWrapId _ -> C.Var (make_var_qid False vName)
151 _ -> C.Var (make_var_qid isLocal vName)
152 make_exp (Lit (MachLabel s _)) = return $ C.Label (unpackFS s)
153 make_exp (Lit l) = return $ C.Lit (make_lit l)
154 make_exp (App e (Type t)) = make_exp e >>= (\ b -> return $ C.Appt b (make_ty t))
155 make_exp (App e1 e2) = do
158 return $ C.App rator rand
159 make_exp (Lam v e) | isTyVar v = make_exp e >>= (\ b ->
160 return $ C.Lam (C.Tb (make_tbind v)) b)
161 make_exp (Lam v e) | otherwise = make_exp e >>= (\ b ->
162 return $ C.Lam (C.Vb (make_vbind v)) b)
163 make_exp (Cast e co) = make_exp e >>= (\ b -> return $ C.Cast b (make_ty co))
164 make_exp (Let b e) = do
165 vd <- make_vdef False b
167 return $ C.Let vd body
168 make_exp (Case e v ty alts) = do
170 newAlts <- mapM make_alt alts
171 return $ C.Case scrut (make_vbind v) (make_ty ty) newAlts
172 make_exp (Note (SCC _) e) = make_exp e >>= (return . C.Note "SCC") -- temporary
173 make_exp (Note (CoreNote s) e) = make_exp e >>= (return . C.Note s) -- hdaume: core annotations
174 make_exp (Note InlineMe e) = make_exp e >>= (return . C.Note "InlineMe")
175 make_exp _ = error "MkExternalCore died: make_exp"
177 make_alt :: CoreAlt -> CoreM C.Alt
178 make_alt (DataAlt dcon, vs, e) = do
180 return $ C.Acon (make_con_qid (dataConName dcon))
184 where (tbs,vbs) = span isTyVar vs
185 make_alt (LitAlt l,_,e) = make_exp e >>= (return . (C.Alit (make_lit l)))
186 make_alt (DEFAULT,[],e) = make_exp e >>= (return . C.Adefault)
187 -- This should never happen, as the DEFAULT alternative binds no variables,
188 -- but we might as well check for it:
189 make_alt a@(DEFAULT,_ ,_) = pprPanic ("MkExternalCore: make_alt: DEFAULT "
190 ++ "alternative had a non-empty var list") (ppr a)
193 make_lit :: Literal -> C.Lit
196 -- Note that we need to check whether the character is "big".
197 -- External Core only allows character literals up to '\xff'.
198 MachChar i | i <= chr 0xff -> C.Lchar i t
199 -- For a character bigger than 0xff, we represent it in ext-core
200 -- as an int lit with a char type.
201 MachChar i -> C.Lint (fromIntegral $ ord i) t
202 MachStr s -> C.Lstring (unpackFS s) t
203 MachNullAddr -> C.Lint 0 t
204 MachInt i -> C.Lint i t
205 MachInt64 i -> C.Lint i t
206 MachWord i -> C.Lint i t
207 MachWord64 i -> C.Lint i t
208 MachFloat r -> C.Lrational r t
209 MachDouble r -> C.Lrational r t
210 _ -> error "MkExternalCore died: make_lit"
212 t = make_ty (literalType l)
214 -- Expand type synonyms, then convert.
215 make_ty :: Type -> C.Ty -- Be sure to expand types recursively!
216 -- example: FilePath ~> String ~> [Char]
217 make_ty t | Just expanded <- tcView t = make_ty expanded
218 make_ty t = make_ty' t
220 -- note calls to make_ty so as to expand types recursively
221 make_ty' :: Type -> C.Ty
222 make_ty' (TyVarTy tv) = C.Tvar (make_var_id (tyVarName tv))
223 make_ty' (AppTy t1 t2) = C.Tapp (make_ty t1) (make_ty t2)
224 make_ty' (FunTy t1 t2) = make_ty (TyConApp funTyCon [t1,t2])
225 make_ty' (ForAllTy tv t) = C.Tforall (make_tbind tv) (make_ty t)
226 make_ty' (TyConApp tc ts) = make_tyConApp tc ts
228 -- Newtypes are treated just like any other type constructor; not expanded
229 -- Reason: predTypeRep does substitution and, while substitution deals
230 -- correctly with name capture, it's only correct if you see the uniques!
231 -- If you just see occurrence names, name capture may occur.
232 -- Example: newtype A a = A (forall b. b -> a)
233 -- test :: forall q b. q -> A b
234 -- test _ = undefined
235 -- Here the 'a' gets substituted by 'b', which is captured.
236 -- Another solution would be to expand newtypes before tidying; but that would
237 -- expose the representation in interface files, which definitely isn't right.
238 -- Maybe CoreTidy should know whether to expand newtypes or not?
240 make_ty' (PredTy p) = make_ty (predTypeRep p)
242 make_tyConApp :: TyCon -> [Type] -> C.Ty
243 make_tyConApp tc [t1, t2] | tc == transCoercionTyCon =
244 C.TransCoercion (make_ty t1) (make_ty t2)
245 make_tyConApp tc [t] | tc == symCoercionTyCon =
246 C.SymCoercion (make_ty t)
247 make_tyConApp tc [t1, t2] | tc == unsafeCoercionTyCon =
248 C.UnsafeCoercion (make_ty t1) (make_ty t2)
249 make_tyConApp tc [t] | tc == leftCoercionTyCon =
250 C.LeftCoercion (make_ty t)
251 make_tyConApp tc [t] | tc == rightCoercionTyCon =
252 C.RightCoercion (make_ty t)
253 make_tyConApp tc [t1, t2] | tc == instCoercionTyCon =
254 C.InstCoercion (make_ty t1) (make_ty t2)
255 -- this fails silently if we have an application
256 -- of a wired-in coercion tycon to the wrong number of args.
258 make_tyConApp tc ts =
259 foldl C.Tapp (C.Tcon (qtc tc))
263 make_kind :: Kind -> C.Kind
264 make_kind (PredTy p) | isEqPred p = C.Keq (make_ty t1) (make_ty t2)
265 where (t1, t2) = getEqPredTys p
266 make_kind (FunTy k1 k2) = C.Karrow (make_kind k1) (make_kind k2)
268 | isLiftedTypeKind k = C.Klifted
269 | isUnliftedTypeKind k = C.Kunlifted
270 | isOpenTypeKind k = C.Kopen
271 make_kind _ = error "MkExternalCore died: make_kind"
275 make_id :: Bool -> Name -> C.Id
276 -- include uniques for internal names in order to avoid name shadowing
277 make_id _is_var nm = ((occNameString . nameOccName) nm)
278 ++ (if isInternalName nm then (show . nameUnique) nm else "")
280 make_var_id :: Name -> C.Id
281 make_var_id = make_id True
283 -- It's important to encode the module name here, because in External Core,
284 -- base:GHC.Base => base:GHCziBase
285 -- We don't do this in pprExternalCore because we
286 -- *do* want to keep the package name (we don't want baseZCGHCziBase,
287 -- because that would just be ugly.)
289 -- We encode the package name as well.
290 make_mid :: Module -> C.Id
291 -- Super ugly code, but I can't find anything else that does quite what I
292 -- want (encodes the hierarchical module name without encoding the colon
293 -- that separates the package name from it.)
294 make_mid m = showSDoc $
295 (text $ zEncodeString $ packageIdString $ modulePackageId m)
297 <> (pprEncoded $ pprModuleName $ moduleName m)
298 where pprEncoded = pprCode CStyle
300 make_qid :: Bool -> Bool -> Name -> C.Qual C.Id
301 make_qid force_unqual is_var n = (mname,make_id is_var n)
303 case nameModule_maybe n of
304 Just m | not force_unqual -> make_mid m
307 make_var_qid :: Bool -> Name -> C.Qual C.Id
308 make_var_qid force_unqual = make_qid force_unqual True
310 make_con_qid :: Name -> C.Qual C.Id
311 make_con_qid = make_qid False False
314 isALocal :: Name -> CoreM Bool
317 return $ case nameModule_maybe vName of
318 -- Not sure whether isInternalName corresponds to "local"ness
319 -- in the External Core sense; need to re-read the spec.
320 Just m | m == modName -> isInternalName vName