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 ( TyClDecl(..), HsTupCon(..) )
13 import TcMonoType ( tcIfaceType )
14 import TcEnv ( RecTcEnv, tcExtendTyVarEnv,
15 tcExtendGlobalValEnv, tcSetEnv, tcEnvIds,
16 tcLookupGlobal_maybe, tcLookupRecId_maybe
19 import RnHsSyn ( RenamedTyClDecl )
21 import Literal ( Literal(..) )
23 import CoreUtils ( exprType )
25 import CoreLint ( lintUnfolding )
26 import WorkWrap ( mkWrapper )
28 import Id ( Id, mkVanillaGlobal, mkLocalId, idName, isDataConWrapId_maybe )
29 import Module ( Module )
30 import MkId ( mkCCallOpId )
32 import DataCon ( DataCon, dataConId, dataConSig, dataConArgTys )
33 import Type ( mkTyVarTys, splitAlgTyConApp_maybe )
34 import TysWiredIn ( tupleCon )
35 import Var ( mkTyVar, tyVarKind )
36 import Name ( Name, nameIsLocalOrFrom )
37 import Demand ( wwLazy )
38 import ErrUtils ( pprBagOfErrors )
40 import Util ( zipWithEqual )
41 import HscTypes ( TyThing(..) )
44 Ultimately, type signatures in interfaces will have pragmatic
45 information attached, so it is a good idea to have separate code to
48 As always, we do not have to worry about user-pragmas in interface
52 tcInterfaceSigs :: RecTcEnv -- Envt to use when checking unfoldings
53 -> Module -- This module
54 -> [RenamedTyClDecl] -- Ignore non-sig-decls in these decls
58 tcInterfaceSigs unf_env mod decls
59 = listTc [ do_one name ty id_infos src_loc
60 | IfaceSig {tcdName = name, tcdType = ty, tcdIdInfo = id_infos, tcdLoc =src_loc} <- decls]
62 in_scope_vars = filter (nameIsLocalOrFrom mod . idName) (tcEnvIds unf_env)
63 -- Oops: using isLocalId instead can give a black hole
64 -- because it looks at the idinfo
66 -- When we have hi-boot files, an unfolding might refer to
67 -- something defined in this module, so we must build a
68 -- suitable in-scope set. This thunk will only be poked
69 -- if -dcore-lint is on.
71 do_one name ty id_infos src_loc
72 = tcAddSrcLoc src_loc $
73 tcAddErrCtxt (ifaceSigCtxt name) $
74 tcIfaceType ty `thenTc` \ sigma_ty ->
75 tcIdInfo unf_env in_scope_vars name
76 sigma_ty id_infos `thenTc` \ id_info ->
77 returnTc (mkVanillaGlobal name sigma_ty id_info)
81 tcIdInfo unf_env in_scope_vars name ty info_ins
82 = foldlTc tcPrag vanillaIdInfo info_ins
84 tcPrag info (HsArity arity) = returnTc (info `setArityInfo` arity)
85 tcPrag info (HsNoCafRefs) = returnTc (info `setCafInfo` NoCafRefs)
86 tcPrag info HsCprInfo = returnTc (info `setCprInfo` ReturnsCPR)
88 tcPrag info (HsUnfold inline_prag expr)
89 = tcPragExpr unf_env name in_scope_vars expr `thenNF_Tc` \ maybe_expr' ->
91 -- maybe_expr doesn't get looked at if the unfolding
92 -- is never inspected; so the typecheck doesn't even happen
93 unfold_info = case maybe_expr' of
94 Nothing -> noUnfolding
95 Just expr' -> mkTopUnfolding expr'
96 info1 = info `setUnfoldingInfo` unfold_info
97 info2 = info1 `setInlinePragInfo` inline_prag
101 tcPrag info (HsStrictness strict_info)
102 = returnTc (info `setStrictnessInfo` strict_info)
104 tcPrag info (HsWorker nm)
105 = tcWorkerInfo unf_env ty info nm
109 tcWorkerInfo unf_env ty info worker_name
110 | not (hasArity arity_info)
111 = pprPanic "Worker with no arity info" (ppr worker_name)
114 = uniqSMToTcM (mkWrapper ty arity demands res_bot cpr_info) `thenNF_Tc` \ wrap_fn ->
116 -- Watch out! We can't pull on unf_env too eagerly!
117 info' = case tcLookupRecId_maybe unf_env worker_name of
118 Just worker_id -> info `setUnfoldingInfo` mkTopUnfolding (wrap_fn worker_id)
119 `setWorkerInfo` HasWorker worker_id arity
121 Nothing -> pprTrace "tcWorkerInfo failed:" (ppr worker_name) info
125 -- We are relying here on arity, cpr and strictness info always appearing
126 -- before worker info, fingers crossed ....
127 arity_info = arityInfo info
128 arity = arityLowerBound arity_info
129 cpr_info = cprInfo info
130 (demands, res_bot) = case strictnessInfo info of
131 StrictnessInfo d r -> (d,r)
132 _ -> (take arity (repeat wwLazy),False) -- Noncommittal
135 For unfoldings we try to do the job lazily, so that we never type check
136 an unfolding that isn't going to be looked at.
139 tcPragExpr unf_env name in_scope_vars expr
140 = tcDelay unf_env doc $
141 tcCoreExpr expr `thenTc` \ core_expr' ->
143 -- Check for type consistency in the unfolding
144 tcGetSrcLoc `thenNF_Tc` \ src_loc ->
145 getDOptsTc `thenTc` \ dflags ->
146 case lintUnfolding dflags src_loc in_scope_vars core_expr' of
147 (Nothing,_) -> returnTc core_expr' -- ignore warnings
148 (Just fail_msg,_) -> failWithTc ((doc <+> text "failed Lint") $$ fail_msg)
150 doc = text "unfolding of" <+> ppr name
152 tcDelay :: RecTcEnv -> SDoc -> TcM a -> NF_TcM (Maybe a)
153 tcDelay unf_env doc thing_inside
155 recoverNF_Tc bad_value (
156 tcSetEnv unf_env thing_inside `thenTc` \ r ->
160 -- The trace tells what wasn't available, for the benefit of
161 -- compiler hackers who want to improve it!
162 bad_value = getErrsTc `thenNF_Tc` \ (warns,errs) ->
163 returnNF_Tc (pprTrace "Failed:"
164 (hang doc 4 (pprBagOfErrors errs))
169 Variables in unfoldings
170 ~~~~~~~~~~~~~~~~~~~~~~~
171 ****** Inside here we use only the Global environment, even for locally bound variables.
172 ****** Why? Because we know all the types and want to bind them to real Ids.
175 tcVar :: Name -> TcM Id
177 = tcLookupGlobal_maybe name `thenNF_Tc` \ maybe_id ->
179 Just (AnId id) -> returnTc id ;
180 Nothing -> failWithTc (noDecl name)
183 noDecl name = hsep [ptext SLIT("Warning: no binding for"), ppr name]
189 tcCoreExpr :: UfExpr Name -> TcM CoreExpr
191 tcCoreExpr (UfType ty)
192 = tcIfaceType ty `thenTc` \ ty' ->
193 -- It might not be of kind type
196 tcCoreExpr (UfVar name)
197 = tcVar name `thenTc` \ id ->
200 tcCoreExpr (UfLit lit)
203 -- The dreaded lit-lits are also similar, except here the type
204 -- is read in explicitly rather than being implicit
205 tcCoreExpr (UfLitLit lit ty)
206 = tcIfaceType ty `thenTc` \ ty' ->
207 returnTc (Lit (MachLitLit lit ty'))
209 tcCoreExpr (UfCCall cc ty)
210 = tcIfaceType ty `thenTc` \ ty' ->
211 tcGetUnique `thenNF_Tc` \ u ->
212 returnTc (Var (mkCCallOpId u cc ty'))
214 tcCoreExpr (UfTuple (HsTupCon _ boxity arity) args)
215 = mapTc tcCoreExpr args `thenTc` \ args' ->
217 -- Put the missing type arguments back in
218 con_args = map (Type . exprType) args' ++ args'
220 returnTc (mkApps (Var con_id) con_args)
222 con_id = dataConId (tupleCon boxity arity)
225 tcCoreExpr (UfLam bndr body)
226 = tcCoreLamBndr bndr $ \ bndr' ->
227 tcCoreExpr body `thenTc` \ body' ->
228 returnTc (Lam bndr' body')
230 tcCoreExpr (UfApp fun arg)
231 = tcCoreExpr fun `thenTc` \ fun' ->
232 tcCoreExpr arg `thenTc` \ arg' ->
233 returnTc (App fun' arg')
235 tcCoreExpr (UfCase scrut case_bndr alts)
236 = tcCoreExpr scrut `thenTc` \ scrut' ->
238 scrut_ty = exprType scrut'
239 case_bndr' = mkLocalId case_bndr scrut_ty
241 tcExtendGlobalValEnv [case_bndr'] $
242 mapTc (tcCoreAlt scrut_ty) alts `thenTc` \ alts' ->
243 returnTc (Case scrut' case_bndr' alts')
245 tcCoreExpr (UfLet (UfNonRec bndr rhs) body)
246 = tcCoreExpr rhs `thenTc` \ rhs' ->
247 tcCoreValBndr bndr $ \ bndr' ->
248 tcCoreExpr body `thenTc` \ body' ->
249 returnTc (Let (NonRec bndr' rhs') body')
251 tcCoreExpr (UfLet (UfRec pairs) body)
252 = tcCoreValBndrs bndrs $ \ bndrs' ->
253 mapTc tcCoreExpr rhss `thenTc` \ rhss' ->
254 tcCoreExpr body `thenTc` \ body' ->
255 returnTc (Let (Rec (bndrs' `zip` rhss')) body')
257 (bndrs, rhss) = unzip pairs
259 tcCoreExpr (UfNote note expr)
260 = tcCoreExpr expr `thenTc` \ expr' ->
262 UfCoerce to_ty -> tcIfaceType to_ty `thenTc` \ to_ty' ->
263 returnTc (Note (Coerce to_ty'
264 (exprType expr')) expr')
265 UfInlineCall -> returnTc (Note InlineCall expr')
266 UfInlineMe -> returnTc (Note InlineMe expr')
267 UfSCC cc -> returnTc (Note (SCC cc) expr')
271 tcCoreLamBndr (UfValBinder name ty) thing_inside
272 = tcIfaceType ty `thenTc` \ ty' ->
274 id = mkLocalId name ty'
276 tcExtendGlobalValEnv [id] $
279 tcCoreLamBndr (UfTyBinder name kind) thing_inside
281 tyvar = mkTyVar name kind
283 tcExtendTyVarEnv [tyvar] (thing_inside tyvar)
285 tcCoreLamBndrs [] thing_inside = thing_inside []
286 tcCoreLamBndrs (b:bs) thing_inside
287 = tcCoreLamBndr b $ \ b' ->
288 tcCoreLamBndrs bs $ \ bs' ->
289 thing_inside (b':bs')
291 tcCoreValBndr (UfValBinder name ty) thing_inside
292 = tcIfaceType ty `thenTc` \ ty' ->
294 id = mkLocalId name ty'
296 tcExtendGlobalValEnv [id] $
299 tcCoreValBndrs bndrs thing_inside -- Expect them all to be ValBinders
300 = mapTc tcIfaceType tys `thenTc` \ tys' ->
302 ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys'
304 tcExtendGlobalValEnv ids $
307 names = [name | UfValBinder name _ <- bndrs]
308 tys = [ty | UfValBinder _ ty <- bndrs]
312 tcCoreAlt scrut_ty (UfDefault, names, rhs)
313 = ASSERT( null names )
314 tcCoreExpr rhs `thenTc` \ rhs' ->
315 returnTc (DEFAULT, [], rhs')
317 tcCoreAlt scrut_ty (UfLitAlt lit, names, rhs)
318 = ASSERT( null names )
319 tcCoreExpr rhs `thenTc` \ rhs' ->
320 returnTc (LitAlt lit, [], rhs')
322 tcCoreAlt scrut_ty (UfLitLitAlt str ty, names, rhs)
323 = ASSERT( null names )
324 tcCoreExpr rhs `thenTc` \ rhs' ->
325 tcIfaceType ty `thenTc` \ ty' ->
326 returnTc (LitAlt (MachLitLit str ty'), [], rhs')
328 -- A case alternative is made quite a bit more complicated
329 -- by the fact that we omit type annotations because we can
330 -- work them out. True enough, but its not that easy!
331 tcCoreAlt scrut_ty alt@(con, names, rhs)
332 = tcConAlt con `thenTc` \ con ->
334 (main_tyvars, _, ex_tyvars, _, _, _) = dataConSig con
336 (_, inst_tys, cons) = case splitAlgTyConApp_maybe scrut_ty of
338 Nothing -> pprPanic "tcCoreAlt" (ppr alt)
339 ex_tyvars' = [mkTyVar name (tyVarKind tv) | (name,tv) <- names `zip` ex_tyvars]
340 ex_tys' = mkTyVarTys ex_tyvars'
341 arg_tys = dataConArgTys con (inst_tys ++ ex_tys')
342 id_names = drop (length ex_tyvars) names
345 | length id_names /= length arg_tys
346 = pprPanic "tcCoreAlts" (ppr (con, names, rhs) $$
347 (ppr main_tyvars <+> ppr ex_tyvars) $$
351 = zipWithEqual "tcCoreAlts" mkLocalId id_names arg_tys
353 ASSERT( con `elem` cons && length inst_tys == length main_tyvars )
354 tcExtendTyVarEnv ex_tyvars' $
355 tcExtendGlobalValEnv arg_ids $
356 tcCoreExpr rhs `thenTc` \ rhs' ->
357 returnTc (DataAlt con, ex_tyvars' ++ arg_ids, rhs')
360 tcConAlt :: UfConAlt Name -> TcM DataCon
361 tcConAlt (UfTupleAlt (HsTupCon _ boxity arity))
362 = returnTc (tupleCon boxity arity)
364 tcConAlt (UfDataAlt con_name)
365 = tcVar con_name `thenTc` \ con_id ->
366 returnTc (case isDataConWrapId_maybe con_id of
368 Nothing -> pprPanic "tcCoreAlt" (ppr con_id))
372 ifaceSigCtxt sig_name
373 = hsep [ptext SLIT("In an interface-file signature for"), ppr sig_name]