2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[TcIfaceSig]{Type checking of type signatures in interface files}
7 module TcIfaceSig ( tcInterfaceSigs, tcVar, tcCoreExpr, tcCoreLamBndrs ) where
9 #include "HsVersions.h"
11 import HsSyn ( HsDecl(..), IfaceSig(..) )
13 import TcMonoType ( tcHsType, tcHsTypeKind,
14 -- NB: all the tyars in interface files are kinded,
15 -- so tcHsType will do the Right Thing without
16 -- having to mess about with zonking
19 import TcEnv ( ValueEnv, tcExtendTyVarEnv,
20 tcExtendGlobalValEnv, tcSetValueEnv,
21 tcLookupTyConByKey, tcLookupValueMaybe,
22 explicitLookupValue, badCon, badPrimOp
24 import TcType ( TcKind, kindToTcKind )
26 import RnHsSyn ( RenamedHsDecl )
28 import CallConv ( cCallConv )
29 import Const ( Con(..), Literal(..) )
31 import CoreUtils ( coreExprType )
33 import CoreLint ( lintUnfolding )
34 import WwLib ( mkWrapper )
35 import PrimOp ( PrimOp(..) )
37 import Id ( Id, mkId, mkVanillaId,
38 isPrimitiveId_maybe, isDataConId_maybe
41 import DataCon ( dataConSig, dataConArgTys )
42 import Type ( mkSynTy, mkTyVarTys, splitAlgTyConApp )
43 import Var ( IdOrTyVar, mkTyVar, tyVarKind )
45 import Name ( Name, NamedThing(..) )
46 import Unique ( rationalTyConKey )
47 import TysWiredIn ( integerTy, stringTy )
48 import Demand ( wwLazy )
49 import ErrUtils ( pprBagOfErrors )
50 import Maybes ( maybeToBool, MaybeErr(..) )
52 import Util ( zipWithEqual )
55 Ultimately, type signatures in interfaces will have pragmatic
56 information attached, so it is a good idea to have separate code to
59 As always, we do not have to worry about user-pragmas in interface
63 tcInterfaceSigs :: ValueEnv -- Envt to use when checking unfoldings
64 -> [RenamedHsDecl] -- Ignore non-sig-decls in these decls
68 tcInterfaceSigs unf_env (SigD (IfaceSig name ty id_infos src_loc) : rest)
69 = tcAddSrcLoc src_loc (
70 tcAddErrCtxt (ifaceSigCtxt name) (
71 tcHsType ty `thenTc` \ sigma_ty ->
72 tcIdInfo unf_env name sigma_ty vanillaIdInfo id_infos `thenTc` \ id_info ->
73 returnTc (mkId name sigma_ty id_info)
74 )) `thenTc` \ sig_id ->
75 tcInterfaceSigs unf_env rest `thenTc` \ sig_ids ->
76 returnTc (sig_id : sig_ids)
78 tcInterfaceSigs unf_env (other_decl : rest) = tcInterfaceSigs unf_env rest
80 tcInterfaceSigs unf_env [] = returnTc []
84 tcIdInfo unf_env name ty info info_ins
85 = foldlTc tcPrag vanillaIdInfo info_ins
87 tcPrag info (HsArity arity) = returnTc (info `setArityInfo` arity)
88 tcPrag info (HsUpdate upd) = returnTc (info `setUpdateInfo` upd)
89 tcPrag info (HsNoCafRefs) = returnTc (info `setCafInfo` NoCafRefs)
90 tcPrag info (HsCprInfo cpr_info) = returnTc (info `setCprInfo` cpr_info)
92 tcPrag info (HsUnfold inline_prag maybe_expr)
94 Just expr -> tcPragExpr unf_env name [] expr
95 Nothing -> returnNF_Tc Nothing
96 ) `thenNF_Tc` \ maybe_expr' ->
98 -- maybe_expr doesn't get looked at if the unfolding
99 -- is never inspected; so the typecheck doesn't even happen
100 unfold_info = case maybe_expr' of
101 Nothing -> noUnfolding
102 Just expr' -> mkUnfolding expr'
103 info1 = info `setUnfoldingInfo` unfold_info
104 info2 = info1 `setInlinePragInfo` inline_prag
108 tcPrag info (HsStrictness (HsStrictnessInfo (demands,bot_result)))
109 = returnTc (info `setStrictnessInfo` StrictnessInfo demands bot_result)
111 tcPrag info (HsWorker nm)
112 = tcWorkerInfo unf_env ty info nm
116 tcWorkerInfo unf_env ty info worker_name
118 = pprPanic "Worker with no arity info" (ppr worker_name)
121 = uniqSMToTcM (mkWrapper ty arity demands cpr_info) `thenNF_Tc` \ wrap_fn ->
123 -- Watch out! We can't pull on unf_env too eagerly!
124 info' = case explicitLookupValue unf_env worker_name of
125 Just worker_id -> info `setUnfoldingInfo` mkUnfolding (wrap_fn worker_id)
126 `setWorkerInfo` Just worker_id
128 Nothing -> pprTrace "tcWorkerInfo failed:" (ppr worker_name) info
132 -- We are relying here on arity, cpr and strictness info always appearing
133 -- before worker info, fingers crossed ....
134 arity = arityLowerBound (arityInfo info)
135 cpr_info = cprInfo info
136 demands = case strictnessInfo info of
137 StrictnessInfo d _ -> d
138 _ -> repeat wwLazy -- Noncommittal
141 For unfoldings we try to do the job lazily, so that we never type check
142 an unfolding that isn't going to be looked at.
145 tcPragExpr unf_env name in_scope_vars expr
146 = tcDelay unf_env doc $
147 tcCoreExpr expr `thenTc` \ core_expr' ->
149 -- Check for type consistency in the unfolding
150 tcGetSrcLoc `thenNF_Tc` \ src_loc ->
151 case lintUnfolding src_loc in_scope_vars core_expr' of
152 Nothing -> returnTc core_expr'
153 Just fail_msg -> failWithTc ((doc <+> text "failed Lint") $$ fail_msg)
155 doc = text "unfolding of" <+> ppr name
157 tcDelay :: ValueEnv -> SDoc -> TcM s a -> NF_TcM s (Maybe a)
158 tcDelay unf_env doc thing_inside
160 recoverNF_Tc bad_value (
161 tcSetValueEnv unf_env thing_inside `thenTc` \ r ->
165 -- The trace tells what wasn't available, for the benefit of
166 -- compiler hackers who want to improve it!
167 bad_value = getErrsTc `thenNF_Tc` \ (warns,errs) ->
168 returnNF_Tc (pprTrace "Failed:"
169 (hang doc 4 (pprBagOfErrors errs))
174 Variables in unfoldings
175 ~~~~~~~~~~~~~~~~~~~~~~~
176 ****** Inside here we use only the Global environment, even for locally bound variables.
177 ****** Why? Because we know all the types and want to bind them to real Ids.
180 tcVar :: Name -> TcM s Id
182 = tcLookupValueMaybe name `thenNF_Tc` \ maybe_id ->
184 Just id -> returnTc id;
185 Nothing -> failWithTc (noDecl name)
188 noDecl name = hsep [ptext SLIT("Warning: no binding for"), ppr name]
194 tcCoreExpr :: UfExpr Name -> TcM s CoreExpr
196 tcCoreExpr (UfType ty)
197 = tcHsTypeKind ty `thenTc` \ (_, ty') ->
198 -- It might not be of kind type
201 tcCoreExpr (UfVar name)
202 = tcVar name `thenTc` \ id ->
205 tcCoreExpr (UfCon con args)
206 = tcUfCon con `thenTc` \ con' ->
207 mapTc tcCoreExpr args `thenTc` \ args' ->
208 returnTc (Con con' args')
210 tcCoreExpr (UfTuple name args)
211 = tcUfDataCon name `thenTc` \ con ->
212 mapTc tcCoreExpr args `thenTc` \ args' ->
214 -- Put the missing type arguments back in
215 con_args = map (Type . coreExprType) args' ++ args'
217 returnTc (Con con con_args)
219 tcCoreExpr (UfLam bndr body)
220 = tcCoreLamBndr bndr $ \ bndr' ->
221 tcCoreExpr body `thenTc` \ body' ->
222 returnTc (Lam bndr' body')
224 tcCoreExpr (UfApp fun arg)
225 = tcCoreExpr fun `thenTc` \ fun' ->
226 tcCoreExpr arg `thenTc` \ arg' ->
227 returnTc (App fun' arg')
229 tcCoreExpr (UfCase scrut case_bndr alts)
230 = tcCoreExpr scrut `thenTc` \ scrut' ->
232 scrut_ty = coreExprType scrut'
233 case_bndr' = mkVanillaId case_bndr scrut_ty
235 tcExtendGlobalValEnv [case_bndr'] $
236 mapTc (tcCoreAlt scrut_ty) alts `thenTc` \ alts' ->
237 returnTc (Case scrut' case_bndr' alts')
239 tcCoreExpr (UfLet (UfNonRec bndr rhs) body)
240 = tcCoreExpr rhs `thenTc` \ rhs' ->
241 tcCoreValBndr bndr $ \ bndr' ->
242 tcCoreExpr body `thenTc` \ body' ->
243 returnTc (Let (NonRec bndr' rhs') body')
245 tcCoreExpr (UfLet (UfRec pairs) body)
246 = tcCoreValBndrs bndrs $ \ bndrs' ->
247 mapTc tcCoreExpr rhss `thenTc` \ rhss' ->
248 tcCoreExpr body `thenTc` \ body' ->
249 returnTc (Let (Rec (bndrs' `zip` rhss')) body')
251 (bndrs, rhss) = unzip pairs
253 tcCoreExpr (UfNote note expr)
254 = tcCoreExpr expr `thenTc` \ expr' ->
256 UfCoerce to_ty -> tcHsType to_ty `thenTc` \ to_ty' ->
257 returnTc (Note (Coerce to_ty' (coreExprType expr')) expr')
258 UfInlineCall -> returnTc (Note InlineCall expr')
259 UfInlineMe -> returnTc (Note InlineMe expr')
260 UfSCC cc -> returnTc (Note (SCC cc) expr')
262 tcCoreNote (UfSCC cc) = returnTc (SCC cc)
263 tcCoreNote UfInlineCall = returnTc InlineCall
266 -- rationalTy isn't built in so, we have to construct it
267 -- (the "ty" part of the incoming literal is simply bottom)
268 tcUfCon (UfLitCon (NoRepRational lit _))
269 = tcLookupTyConByKey rationalTyConKey `thenNF_Tc` \ rational_tycon ->
271 rational_ty = mkSynTy rational_tycon []
273 returnTc (Literal (NoRepRational lit rational_ty))
275 -- Similarly for integers and strings, except that they are wired in
276 tcUfCon (UfLitCon (NoRepInteger lit _))
277 = returnTc (Literal (NoRepInteger lit integerTy))
278 tcUfCon (UfLitCon (NoRepStr lit _))
279 = returnTc (Literal (NoRepStr lit stringTy))
281 tcUfCon (UfLitCon other_lit)
282 = returnTc (Literal other_lit)
284 -- The dreaded lit-lits are also similar, except here the type
285 -- is read in explicitly rather than being implicit
286 tcUfCon (UfLitLitCon lit ty)
287 = tcHsType ty `thenTc` \ ty' ->
288 returnTc (Literal (MachLitLit lit ty'))
290 tcUfCon (UfDataCon name) = tcUfDataCon name
292 tcUfCon (UfPrimOp name)
293 = tcVar name `thenTc` \ op_id ->
294 case isPrimitiveId_maybe op_id of
295 Just op -> returnTc (PrimOp op)
296 Nothing -> failWithTc (badPrimOp name)
298 tcUfCon (UfCCallOp str is_dyn casm gc)
301 tcGetUnique `thenNF_Tc` \ u ->
302 returnTc (PrimOp (CCallOp (Right u) casm gc cCallConv))
303 False -> returnTc (PrimOp (CCallOp (Left str) casm gc cCallConv))
306 = tcVar name `thenTc` \ con_id ->
307 case isDataConId_maybe con_id of
308 Just con -> returnTc (DataCon con)
309 Nothing -> failWithTc (badCon name)
313 tcCoreLamBndr (UfValBinder name ty) thing_inside
314 = tcHsType ty `thenTc` \ ty' ->
316 id = mkVanillaId name ty'
318 tcExtendGlobalValEnv [id] $
321 tcCoreLamBndr (UfTyBinder name kind) thing_inside
323 tyvar = mkTyVar name kind
325 tcExtendTyVarEnv [tyvar] (thing_inside tyvar)
327 tcCoreLamBndrs [] thing_inside = thing_inside []
328 tcCoreLamBndrs (b:bs) thing_inside
329 = tcCoreLamBndr b $ \ b' ->
330 tcCoreLamBndrs bs $ \ bs' ->
331 thing_inside (b':bs')
333 tcCoreValBndr (UfValBinder name ty) thing_inside
334 = tcHsType ty `thenTc` \ ty' ->
336 id = mkVanillaId name ty'
338 tcExtendGlobalValEnv [id] $
341 tcCoreValBndrs bndrs thing_inside -- Expect them all to be ValBinders
342 = mapTc tcHsType tys `thenTc` \ tys' ->
344 ids = zipWithEqual "tcCoreValBndr" mkVanillaId names tys'
346 tcExtendGlobalValEnv ids $
349 names = [name | UfValBinder name _ <- bndrs]
350 tys = [ty | UfValBinder _ ty <- bndrs]
354 tcCoreAlt scrut_ty (UfDefault, names, rhs)
355 = ASSERT( null names )
356 tcCoreExpr rhs `thenTc` \ rhs' ->
357 returnTc (DEFAULT, [], rhs')
359 tcCoreAlt scrut_ty (UfLitCon lit, names, rhs)
360 = ASSERT( null names )
361 tcCoreExpr rhs `thenTc` \ rhs' ->
362 returnTc (Literal lit, [], rhs')
364 tcCoreAlt scrut_ty (UfLitLitCon str ty, names, rhs)
365 = ASSERT( null names )
366 tcCoreExpr rhs `thenTc` \ rhs' ->
367 tcHsType ty `thenTc` \ ty' ->
368 returnTc (Literal (MachLitLit str ty'), [], rhs')
370 -- A case alternative is made quite a bit more complicated
371 -- by the fact that we omit type annotations because we can
372 -- work them out. True enough, but its not that easy!
373 tcCoreAlt scrut_ty (UfDataCon con_name, names, rhs)
374 = tcVar con_name `thenTc` \ con_id ->
376 con = case isDataConId_maybe con_id of
378 Nothing -> pprPanic "tcCoreAlt" (ppr con_id)
380 (main_tyvars, _, ex_tyvars, _, _, _) = dataConSig con
382 (tycon, inst_tys, cons) = splitAlgTyConApp scrut_ty
383 ex_tyvars' = [mkTyVar name (tyVarKind tv) | (name,tv) <- names `zip` ex_tyvars]
384 ex_tys' = mkTyVarTys ex_tyvars'
385 arg_tys = dataConArgTys con (inst_tys ++ ex_tys')
386 id_names = drop (length ex_tyvars) names
389 | length id_names /= length arg_tys
390 = pprPanic "tcCoreAlts" (ppr (con_name, names, rhs) $$
391 (ppr main_tyvars <+> ppr ex_tyvars) $$
395 = zipWithEqual "tcCoreAlts" mkVanillaId id_names arg_tys
397 ASSERT( con `elem` cons && length inst_tys == length main_tyvars )
398 tcExtendTyVarEnv ex_tyvars' $
399 tcExtendGlobalValEnv arg_ids $
400 tcCoreExpr rhs `thenTc` \ rhs' ->
401 returnTc (DataCon con, ex_tyvars' ++ arg_ids, rhs')
405 ifaceSigCtxt sig_name
406 = hsep [ptext SLIT("In an interface-file signature for"), ppr sig_name]