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, valueEnvIds
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 WorkWrap ( 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, unUsgTy )
43 import Var ( IdOrTyVar, mkTyVar, tyVarKind )
45 import Name ( Name, NamedThing(..), isLocallyDefined )
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 decls
69 = listTc [ do_one name ty id_infos src_loc
70 | SigD (IfaceSig name ty id_infos src_loc) <- decls]
72 in_scope_vars = filter isLocallyDefined (valueEnvIds unf_env)
74 do_one name ty id_infos src_loc
75 = tcAddSrcLoc src_loc $
76 tcAddErrCtxt (ifaceSigCtxt name) $
77 tcHsType ty `thenTc` \ sigma_ty ->
78 tcIdInfo unf_env in_scope_vars name
79 sigma_ty vanillaIdInfo id_infos `thenTc` \ id_info ->
80 returnTc (mkId name sigma_ty id_info)
84 tcIdInfo unf_env in_scope_vars 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 expr)
93 = tcPragExpr unf_env name in_scope_vars expr `thenNF_Tc` \ maybe_expr' ->
95 -- maybe_expr doesn't get looked at if the unfolding
96 -- is never inspected; so the typecheck doesn't even happen
97 unfold_info = case maybe_expr' of
98 Nothing -> noUnfolding
99 Just expr' -> mkTopUnfolding expr'
100 info1 = info `setUnfoldingInfo` unfold_info
101 info2 = info1 `setInlinePragInfo` inline_prag
105 tcPrag info (HsStrictness (HsStrictnessInfo (demands,bot_result)))
106 = returnTc (info `setStrictnessInfo` StrictnessInfo demands bot_result)
108 tcPrag info (HsWorker nm)
109 = tcWorkerInfo unf_env ty info nm
113 tcWorkerInfo unf_env ty info worker_name
114 | not (hasArity arity_info)
115 = pprPanic "Worker with no arity info" (ppr worker_name)
118 = uniqSMToTcM (mkWrapper ty arity demands cpr_info) `thenNF_Tc` \ wrap_fn ->
120 -- Watch out! We can't pull on unf_env too eagerly!
121 info' = case explicitLookupValue unf_env worker_name of
122 Just worker_id -> info `setUnfoldingInfo` mkTopUnfolding (wrap_fn worker_id)
123 `setWorkerInfo` Just worker_id
125 Nothing -> pprTrace "tcWorkerInfo failed:" (ppr worker_name) info
129 -- We are relying here on arity, cpr and strictness info always appearing
130 -- before worker info, fingers crossed ....
131 arity_info = arityInfo info
132 arity = arityLowerBound arity_info
133 cpr_info = cprInfo info
134 demands = case strictnessInfo info of
135 StrictnessInfo d _ -> d
136 _ -> take arity (repeat wwLazy) -- Noncommittal
139 For unfoldings we try to do the job lazily, so that we never type check
140 an unfolding that isn't going to be looked at.
143 tcPragExpr unf_env name in_scope_vars expr
144 = tcDelay unf_env doc $
145 tcCoreExpr expr `thenTc` \ core_expr' ->
147 -- Check for type consistency in the unfolding
148 tcGetSrcLoc `thenNF_Tc` \ src_loc ->
149 case lintUnfolding src_loc in_scope_vars core_expr' of
150 Nothing -> returnTc core_expr'
151 Just fail_msg -> failWithTc ((doc <+> text "failed Lint") $$ fail_msg)
153 doc = text "unfolding of" <+> ppr name
155 tcDelay :: ValueEnv -> SDoc -> TcM s a -> NF_TcM s (Maybe a)
156 tcDelay unf_env doc thing_inside
158 recoverNF_Tc bad_value (
159 tcSetValueEnv unf_env thing_inside `thenTc` \ r ->
163 -- The trace tells what wasn't available, for the benefit of
164 -- compiler hackers who want to improve it!
165 bad_value = getErrsTc `thenNF_Tc` \ (warns,errs) ->
166 returnNF_Tc (pprTrace "Failed:"
167 (hang doc 4 (pprBagOfErrors errs))
172 Variables in unfoldings
173 ~~~~~~~~~~~~~~~~~~~~~~~
174 ****** Inside here we use only the Global environment, even for locally bound variables.
175 ****** Why? Because we know all the types and want to bind them to real Ids.
178 tcVar :: Name -> TcM s Id
180 = tcLookupValueMaybe name `thenNF_Tc` \ maybe_id ->
182 Just id -> returnTc id;
183 Nothing -> failWithTc (noDecl name)
186 noDecl name = hsep [ptext SLIT("Warning: no binding for"), ppr name]
192 tcCoreExpr :: UfExpr Name -> TcM s CoreExpr
194 tcCoreExpr (UfType ty)
195 = tcHsTypeKind ty `thenTc` \ (_, ty') ->
196 -- It might not be of kind type
199 tcCoreExpr (UfVar name)
200 = tcVar name `thenTc` \ id ->
203 tcCoreExpr (UfCon con args)
204 = tcUfCon con `thenTc` \ con' ->
205 mapTc tcCoreExpr args `thenTc` \ args' ->
206 returnTc (Con con' args')
208 tcCoreExpr (UfTuple name args)
209 = tcUfDataCon name `thenTc` \ con ->
210 mapTc tcCoreExpr args `thenTc` \ args' ->
212 -- Put the missing type arguments back in
213 con_args = map (Type . unUsgTy . coreExprType) args' ++ args'
215 returnTc (Con con con_args)
217 tcCoreExpr (UfLam bndr body)
218 = tcCoreLamBndr bndr $ \ bndr' ->
219 tcCoreExpr body `thenTc` \ body' ->
220 returnTc (Lam bndr' body')
222 tcCoreExpr (UfApp fun arg)
223 = tcCoreExpr fun `thenTc` \ fun' ->
224 tcCoreExpr arg `thenTc` \ arg' ->
225 returnTc (App fun' arg')
227 tcCoreExpr (UfCase scrut case_bndr alts)
228 = tcCoreExpr scrut `thenTc` \ scrut' ->
230 scrut_ty = coreExprType scrut'
231 case_bndr' = mkVanillaId case_bndr scrut_ty
233 tcExtendGlobalValEnv [case_bndr'] $
234 mapTc (tcCoreAlt scrut_ty) alts `thenTc` \ alts' ->
235 returnTc (Case scrut' case_bndr' alts')
237 tcCoreExpr (UfLet (UfNonRec bndr rhs) body)
238 = tcCoreExpr rhs `thenTc` \ rhs' ->
239 tcCoreValBndr bndr $ \ bndr' ->
240 tcCoreExpr body `thenTc` \ body' ->
241 returnTc (Let (NonRec bndr' rhs') body')
243 tcCoreExpr (UfLet (UfRec pairs) body)
244 = tcCoreValBndrs bndrs $ \ bndrs' ->
245 mapTc tcCoreExpr rhss `thenTc` \ rhss' ->
246 tcCoreExpr body `thenTc` \ body' ->
247 returnTc (Let (Rec (bndrs' `zip` rhss')) body')
249 (bndrs, rhss) = unzip pairs
251 tcCoreExpr (UfNote note expr)
252 = tcCoreExpr expr `thenTc` \ expr' ->
254 UfCoerce to_ty -> tcHsType to_ty `thenTc` \ to_ty' ->
255 returnTc (Note (Coerce (unUsgTy to_ty')
256 (unUsgTy (coreExprType expr'))) expr')
257 UfInlineCall -> returnTc (Note InlineCall expr')
258 UfInlineMe -> returnTc (Note InlineMe expr')
259 UfSCC cc -> returnTc (Note (SCC cc) expr')
261 tcCoreNote (UfSCC cc) = returnTc (SCC cc)
262 tcCoreNote UfInlineCall = returnTc InlineCall
265 -- rationalTy isn't built in so, we have to construct it
266 -- (the "ty" part of the incoming literal is simply bottom)
267 tcUfCon (UfLitCon (NoRepRational lit _))
268 = tcLookupTyConByKey rationalTyConKey `thenNF_Tc` \ rational_tycon ->
270 rational_ty = mkSynTy rational_tycon []
272 returnTc (Literal (NoRepRational lit rational_ty))
274 -- Similarly for integers and strings, except that they are wired in
275 tcUfCon (UfLitCon (NoRepInteger lit _))
276 = returnTc (Literal (NoRepInteger lit integerTy))
277 tcUfCon (UfLitCon (NoRepStr lit _))
278 = returnTc (Literal (NoRepStr lit stringTy))
280 tcUfCon (UfLitCon other_lit)
281 = returnTc (Literal other_lit)
283 -- The dreaded lit-lits are also similar, except here the type
284 -- is read in explicitly rather than being implicit
285 tcUfCon (UfLitLitCon lit ty)
286 = tcHsType ty `thenTc` \ ty' ->
287 returnTc (Literal (MachLitLit lit ty'))
289 tcUfCon (UfDataCon name) = tcUfDataCon name
291 tcUfCon (UfPrimOp name)
292 = tcVar name `thenTc` \ op_id ->
293 case isPrimitiveId_maybe op_id of
294 Just op -> returnTc (PrimOp op)
295 Nothing -> failWithTc (badPrimOp name)
297 tcUfCon (UfCCallOp str is_dyn casm gc)
300 tcGetUnique `thenNF_Tc` \ u ->
301 returnTc (PrimOp (CCallOp (Right u) casm gc cCallConv))
302 False -> returnTc (PrimOp (CCallOp (Left str) casm gc cCallConv))
305 = tcVar name `thenTc` \ con_id ->
306 case isDataConId_maybe con_id of
307 Just con -> returnTc (DataCon con)
308 Nothing -> failWithTc (badCon name)
312 tcCoreLamBndr (UfValBinder name ty) thing_inside
313 = tcHsType ty `thenTc` \ ty' ->
315 id = mkVanillaId name ty'
317 tcExtendGlobalValEnv [id] $
320 tcCoreLamBndr (UfTyBinder name kind) thing_inside
322 tyvar = mkTyVar name kind
324 tcExtendTyVarEnv [tyvar] (thing_inside tyvar)
326 tcCoreLamBndrs [] thing_inside = thing_inside []
327 tcCoreLamBndrs (b:bs) thing_inside
328 = tcCoreLamBndr b $ \ b' ->
329 tcCoreLamBndrs bs $ \ bs' ->
330 thing_inside (b':bs')
332 tcCoreValBndr (UfValBinder name ty) thing_inside
333 = tcHsType ty `thenTc` \ ty' ->
335 id = mkVanillaId name ty'
337 tcExtendGlobalValEnv [id] $
340 tcCoreValBndrs bndrs thing_inside -- Expect them all to be ValBinders
341 = mapTc tcHsType tys `thenTc` \ tys' ->
343 ids = zipWithEqual "tcCoreValBndr" mkVanillaId names tys'
345 tcExtendGlobalValEnv ids $
348 names = [name | UfValBinder name _ <- bndrs]
349 tys = [ty | UfValBinder _ ty <- bndrs]
353 tcCoreAlt scrut_ty (UfDefault, names, rhs)
354 = ASSERT( null names )
355 tcCoreExpr rhs `thenTc` \ rhs' ->
356 returnTc (DEFAULT, [], rhs')
358 tcCoreAlt scrut_ty (UfLitCon lit, names, rhs)
359 = ASSERT( null names )
360 tcCoreExpr rhs `thenTc` \ rhs' ->
361 returnTc (Literal lit, [], rhs')
363 tcCoreAlt scrut_ty (UfLitLitCon str ty, names, rhs)
364 = ASSERT( null names )
365 tcCoreExpr rhs `thenTc` \ rhs' ->
366 tcHsType ty `thenTc` \ ty' ->
367 returnTc (Literal (MachLitLit str ty'), [], rhs')
369 -- A case alternative is made quite a bit more complicated
370 -- by the fact that we omit type annotations because we can
371 -- work them out. True enough, but its not that easy!
372 tcCoreAlt scrut_ty (UfDataCon con_name, names, rhs)
373 = tcVar con_name `thenTc` \ con_id ->
375 con = case isDataConId_maybe con_id of
377 Nothing -> pprPanic "tcCoreAlt" (ppr con_id)
379 (main_tyvars, _, ex_tyvars, _, _, _) = dataConSig con
381 (tycon, inst_tys, cons) = splitAlgTyConApp scrut_ty
382 ex_tyvars' = [mkTyVar name (tyVarKind tv) | (name,tv) <- names `zip` ex_tyvars]
383 ex_tys' = mkTyVarTys ex_tyvars'
384 arg_tys = dataConArgTys con (inst_tys ++ ex_tys')
385 id_names = drop (length ex_tyvars) names
388 | length id_names /= length arg_tys
389 = pprPanic "tcCoreAlts" (ppr (con_name, names, rhs) $$
390 (ppr main_tyvars <+> ppr ex_tyvars) $$
394 = zipWithEqual "tcCoreAlts" mkVanillaId id_names arg_tys
396 ASSERT( con `elem` cons && length inst_tys == length main_tyvars )
397 tcExtendTyVarEnv ex_tyvars' $
398 tcExtendGlobalValEnv arg_ids $
399 tcCoreExpr rhs `thenTc` \ rhs' ->
400 returnTc (DataCon con, ex_tyvars' ++ arg_ids, rhs')
404 ifaceSigCtxt sig_name
405 = hsep [ptext SLIT("In an interface-file signature for"), ppr sig_name]