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, tcDelay, 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 ( mkFCallId )
32 import TyCon ( tyConDataCons )
33 import DataCon ( DataCon, dataConId, dataConSig, dataConArgTys )
34 import Type ( mkTyVarTys, splitTyConApp )
35 import TysWiredIn ( tupleCon )
36 import Var ( mkTyVar, tyVarKind )
37 import Name ( Name, nameIsLocalOrFrom )
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 init_info info_ins
84 -- set the CgInfo to something sensible but uninformative before
85 -- we start, because the default CgInfo is a panic.
86 init_info = vanillaIdInfo `setCgInfo` vanillaCgInfo
88 tcPrag info (HsNoCafRefs) = returnTc (info `setCafInfo` NoCafRefs)
90 tcPrag info (HsArity arity) =
91 returnTc (info `setArityInfo` arity
94 tcPrag info (HsUnfold inline_prag expr)
95 = tcPragExpr unf_env name in_scope_vars expr `thenNF_Tc` \ maybe_expr' ->
97 -- maybe_expr doesn't get looked at if the unfolding
98 -- is never inspected; so the typecheck doesn't even happen
99 unfold_info = case maybe_expr' of
100 Nothing -> noUnfolding
101 Just expr' -> mkTopUnfolding expr'
102 info1 = info `setUnfoldingInfo` unfold_info
103 info2 = info1 `setInlinePragInfo` inline_prag
107 tcPrag info (HsStrictness strict_info)
108 = returnTc (info `setNewStrictnessInfo` Just strict_info)
110 tcPrag info (HsWorker nm arity)
111 = tcWorkerInfo unf_env ty info nm arity
115 tcWorkerInfo unf_env ty info worker_name arity
116 = uniqSMToTcM (mkWrapper ty strict_sig) `thenNF_Tc` \ wrap_fn ->
118 -- Watch out! We can't pull on unf_env too eagerly!
119 info' = case tcLookupRecId_maybe unf_env worker_name of
121 info `setUnfoldingInfo` mkTopUnfolding (wrap_fn worker_id)
122 `setWorkerInfo` HasWorker worker_id arity
124 Nothing -> pprTrace "tcWorkerInfo failed:"
125 (ppr worker_name) info
129 -- We are relying here on strictness info always appearing
130 -- before worker info, fingers crossed ....
131 strict_sig = case newStrictnessInfo info of
133 Nothing -> pprPanic "Worker info but no strictness for" (ppr worker_name)
136 For unfoldings we try to do the job lazily, so that we never type check
137 an unfolding that isn't going to be looked at.
140 tcPragExpr unf_env name in_scope_vars expr
141 = tcDelay unf_env doc Nothing $
142 tcCoreExpr expr `thenTc` \ core_expr' ->
144 -- Check for type consistency in the unfolding
145 tcGetSrcLoc `thenNF_Tc` \ src_loc ->
146 getDOptsTc `thenTc` \ dflags ->
147 case lintUnfolding dflags src_loc in_scope_vars core_expr' of
148 (Nothing,_) -> returnTc (Just core_expr') -- ignore warnings
149 (Just fail_msg,_) -> failWithTc ((doc <+> text "failed Lint") $$ fail_msg)
151 doc = text "unfolding of" <+> ppr name
153 tcDelay :: RecTcEnv -> SDoc -> a -> TcM a -> NF_TcM a
154 tcDelay unf_env doc bad_ans thing_inside
156 recoverNF_Tc bad_value (
157 tcSetEnv unf_env thing_inside
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 (UfFCall cc ty)
210 = tcIfaceType ty `thenTc` \ ty' ->
211 tcGetUnique `thenNF_Tc` \ u ->
212 returnTc (Var (mkFCallId 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 (tycon, inst_tys) = splitTyConApp scrut_ty -- NB: not tcSplitTyConApp
337 -- We are looking at Core here
338 ex_tyvars' = [mkTyVar name (tyVarKind tv) | (name,tv) <- names `zip` ex_tyvars]
339 ex_tys' = mkTyVarTys ex_tyvars'
340 arg_tys = dataConArgTys con (inst_tys ++ ex_tys')
341 id_names = drop (length ex_tyvars) names
344 | length id_names /= length arg_tys
345 = pprPanic "tcCoreAlts" (ppr (con, names, rhs) $$
346 (ppr main_tyvars <+> ppr ex_tyvars) $$
350 = zipWithEqual "tcCoreAlts" mkLocalId id_names arg_tys
352 ASSERT( con `elem` tyConDataCons tycon && length inst_tys == length main_tyvars )
353 tcExtendTyVarEnv ex_tyvars' $
354 tcExtendGlobalValEnv arg_ids $
355 tcCoreExpr rhs `thenTc` \ rhs' ->
356 returnTc (DataAlt con, ex_tyvars' ++ arg_ids, rhs')
359 tcConAlt :: UfConAlt Name -> TcM DataCon
360 tcConAlt (UfTupleAlt (HsTupCon _ boxity arity))
361 = returnTc (tupleCon boxity arity)
363 tcConAlt (UfDataAlt con_name)
364 = tcVar con_name `thenTc` \ con_id ->
365 returnTc (case isDataConWrapId_maybe con_id of
367 Nothing -> pprPanic "tcCoreAlt" (ppr con_id))
371 ifaceSigCtxt sig_name
372 = hsep [ptext SLIT("In an interface-file signature for"), ppr sig_name]