2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[RnSource]{Main pass of renamer}
7 module RnSource ( rnDecl, rnSourceDecls, rnHsType, rnHsSigType ) where
9 #include "HsVersions.h"
14 import HsTypes ( hsTyVarNames, pprHsContext )
15 import RdrName ( RdrName, isRdrDataCon, rdrNameOcc, isRdrTyVar, mkRdrNameWkr )
16 import RdrHsSyn ( RdrNameContext, RdrNameHsType, RdrNameConDecl,
17 extractRuleBndrsTyVars, extractHsTyRdrTyVars,
18 extractHsTysRdrTyVars, extractHsCtxtRdrTyVars
23 import RnBinds ( rnTopBinds, rnMethodBinds, renameSigs, unknownSigErr )
24 import RnEnv ( bindTyVarsRn, lookupBndrRn, lookupOccRn, getIPName,
25 lookupImplicitOccRn, lookupImplicitOccsRn,
26 bindLocalsRn, bindLocalRn, bindLocalsFVRn, bindUVarRn,
27 bindTyVarsFVRn, bindTyVarsFV2Rn, extendTyVarEnvFVRn,
28 bindCoreLocalFVRn, bindCoreLocalsFVRn, bindLocalNames,
29 checkDupOrQualNames, checkDupNames,
30 mkImportedGlobalName, mkImportedGlobalFromRdrName,
31 newDFunName, getDFunKey, newImplicitBinder,
32 FreeVars, emptyFVs, plusFV, plusFVs, unitFV,
37 import FunDeps ( oclose )
38 import Class ( FunDep )
40 import Name ( Name, OccName,
41 ExportFlag(..), Provenance(..),
42 nameOccName, NamedThing(..)
45 import OccName ( mkDefaultMethodOcc )
46 import FiniteMap ( elemFM )
47 import PrelInfo ( derivableClassKeys, cCallishClassKeys,
48 deRefStablePtr_RDR, makeStablePtr_RDR,
49 bindIO_RDR, returnIO_RDR
51 import Bag ( bagToList )
52 import List ( partition, nub )
54 import SrcLoc ( SrcLoc )
55 import CmdLineOpts ( opt_GlasgowExts, opt_WarnUnusedMatches ) -- Warn of unused for-all'd tyvars
56 import Unique ( Uniquable(..) )
57 import ErrUtils ( Message )
58 import CStrings ( isCLabelString )
59 import Maybes ( maybeToBool, catMaybes )
63 @rnDecl@ `renames' declarations.
64 It simultaneously performs dependency analysis and precedence parsing.
65 It also does the following error checks:
68 Checks that tyvars are used properly. This includes checking
69 for undefined tyvars, and tyvars in contexts that are ambiguous.
70 (Some of this checking has now been moved to module @TcMonoType@,
71 since we don't have functional dependency information at this point.)
73 Checks that all variable occurences are defined.
75 Checks the @(..)@ etc constraints in the export list.
79 %*********************************************************
81 \subsection{Value declarations}
83 %*********************************************************
86 rnSourceDecls :: [RdrNameHsDecl] -> RnMS ([RenamedHsDecl], FreeVars)
87 -- The decls get reversed, but that's ok
90 = go emptyFVs [] decls
92 -- Fixity and deprecations have been dealt with already; ignore them
93 go fvs ds' [] = returnRn (ds', fvs)
94 go fvs ds' (FixD _:ds) = go fvs ds' ds
95 go fvs ds' (DeprecD _:ds) = go fvs ds' ds
96 go fvs ds' (d:ds) = rnDecl d `thenRn` \(d', fvs') ->
97 go (fvs `plusFV` fvs') (d':ds') ds
101 %*********************************************************
103 \subsection{Value declarations}
105 %*********************************************************
108 -- rnDecl does all the work
109 rnDecl :: RdrNameHsDecl -> RnMS (RenamedHsDecl, FreeVars)
111 rnDecl (ValD binds) = rnTopBinds binds `thenRn` \ (new_binds, fvs) ->
112 returnRn (ValD new_binds, fvs)
115 rnDecl (SigD (IfaceSig name ty id_infos loc))
117 mkImportedGlobalFromRdrName name `thenRn` \ name' ->
118 rnHsType doc_str ty `thenRn` \ (ty',fvs1) ->
119 mapFvRn rnIdInfo id_infos `thenRn` \ (id_infos', fvs2) ->
120 returnRn (SigD (IfaceSig name' ty' id_infos' loc), fvs1 `plusFV` fvs2)
122 doc_str = text "the interface signature for" <+> quotes (ppr name)
125 %*********************************************************
127 \subsection{Type declarations}
129 %*********************************************************
131 @rnTyDecl@ uses the `global name function' to create a new type
132 declaration in which local names have been replaced by their original
133 names, reporting any unknown names.
135 Renaming type variables is a pain. Because they now contain uniques,
136 it is necessary to pass in an association list which maps a parsed
137 tyvar to its @Name@ representation.
138 In some cases (type signatures of values),
139 it is even necessary to go over the type first
140 in order to get the set of tyvars used by it, make an assoc list,
141 and then go over it again to rename the tyvars!
142 However, we can also do some scoping checks at the same time.
145 rnDecl (TyClD (TyData new_or_data context tycon tyvars condecls nconstrs derivings pragmas src_loc))
146 = pushSrcLocRn src_loc $
147 lookupBndrRn tycon `thenRn` \ tycon' ->
148 bindTyVarsFVRn data_doc tyvars $ \ tyvars' ->
149 rnContext data_doc context `thenRn` \ (context', cxt_fvs) ->
150 checkDupOrQualNames data_doc con_names `thenRn_`
151 mapFvRn rnConDecl condecls `thenRn` \ (condecls', con_fvs) ->
152 rnDerivs derivings `thenRn` \ (derivings', deriv_fvs) ->
153 ASSERT(isNoDataPragmas pragmas)
154 returnRn (TyClD (TyData new_or_data context' tycon' tyvars' condecls' nconstrs
155 derivings' noDataPragmas src_loc),
156 cxt_fvs `plusFV` con_fvs `plusFV` deriv_fvs)
158 data_doc = text "the data type declaration for" <+> quotes (ppr tycon)
159 con_names = map conDeclName condecls
161 rnDecl (TyClD (TySynonym name tyvars ty src_loc))
162 = pushSrcLocRn src_loc $
163 lookupBndrRn name `thenRn` \ name' ->
164 bindTyVarsFVRn syn_doc tyvars $ \ tyvars' ->
165 rnHsType syn_doc (unquantify ty) `thenRn` \ (ty', ty_fvs) ->
166 returnRn (TyClD (TySynonym name' tyvars' ty' src_loc), ty_fvs)
168 syn_doc = text "the declaration for type synonym" <+> quotes (ppr name)
170 -- For H98 we do *not* universally quantify on the RHS of a synonym
171 -- Silently discard context... but the tyvars in the rest won't be in scope
172 unquantify (HsForAllTy Nothing ctxt ty) | not opt_GlasgowExts = ty
175 rnDecl (TyClD (ClassDecl context cname tyvars fds sigs mbinds pragmas
176 tname dname dwname snames src_loc))
177 = pushSrcLocRn src_loc $
179 lookupBndrRn cname `thenRn` \ cname' ->
181 -- Deal with the implicit tycon and datacon name
182 -- They aren't in scope (because they aren't visible to the user)
183 -- and what we want to do is simply look them up in the cache;
184 -- we jolly well ought to get a 'hit' there!
185 -- So the 'Imported' part of this call is not relevant.
186 -- Unclean; but since these two are the only place this happens
187 -- I can't work up the energy to do it more beautifully
188 mkImportedGlobalFromRdrName tname `thenRn` \ tname' ->
189 mkImportedGlobalFromRdrName dname `thenRn` \ dname' ->
190 mkImportedGlobalFromRdrName dwname `thenRn` \ dwname' ->
191 mapRn mkImportedGlobalFromRdrName snames `thenRn` \ snames' ->
193 -- Tyvars scope over bindings and context
194 bindTyVarsFV2Rn cls_doc tyvars ( \ clas_tyvar_names tyvars' ->
196 -- Check the superclasses
197 rnContext cls_doc context `thenRn` \ (context', cxt_fvs) ->
199 -- Check the functional dependencies
200 rnFds cls_doc fds `thenRn` \ (fds', fds_fvs) ->
202 -- Check the signatures
204 -- First process the class op sigs, then the fixity sigs.
205 (op_sigs, non_op_sigs) = partition isClassOpSig sigs
207 checkDupOrQualNames sig_doc sig_rdr_names_w_locs `thenRn_`
208 mapFvRn (rn_op cname' clas_tyvar_names fds') op_sigs `thenRn` \ (sigs', sig_fvs) ->
210 binders = mkNameSet [ nm | (ClassOpSig nm _ _ _ _) <- sigs' ]
212 renameSigs (okClsDclSig binders) non_op_sigs `thenRn` \ (non_ops', fix_fvs) ->
215 checkDupOrQualNames meth_doc meth_rdr_names_w_locs `thenRn_`
217 `thenRn` \ (mbinds', meth_fvs) ->
219 -- Typechecker is responsible for checking that we only
220 -- give default-method bindings for things in this class.
221 -- The renamer *could* check this for class decls, but can't
222 -- for instance decls.
224 ASSERT(isNoClassPragmas pragmas)
225 returnRn (TyClD (ClassDecl context' cname' tyvars' fds' (non_ops' ++ sigs') mbinds'
226 NoClassPragmas tname' dname' dwname' snames' src_loc),
235 cls_doc = text "the declaration for class" <+> ppr cname
236 sig_doc = text "the signatures for class" <+> ppr cname
237 meth_doc = text "the default-methods for class" <+> ppr cname
239 sig_rdr_names_w_locs = [(op,locn) | ClassOpSig op _ _ _ locn <- sigs]
240 meth_rdr_names_w_locs = bagToList (collectMonoBinders mbinds)
241 meth_rdr_names = map fst meth_rdr_names_w_locs
243 rn_op clas clas_tyvars clas_fds sig@(ClassOpSig op dm_rdr_name explicit_dm ty locn)
244 = pushSrcLocRn locn $
245 lookupBndrRn op `thenRn` \ op_name ->
247 -- Check the signature
248 rnHsSigType (quotes (ppr op)) ty `thenRn` \ (new_ty, op_ty_fvs) ->
250 check_in_op_ty clas_tyvar =
251 checkRn (clas_tyvar `elemNameSet` oclose clas_fds op_ty_fvs)
252 (classTyVarNotInOpTyErr clas_tyvar sig)
254 mapRn_ check_in_op_ty clas_tyvars `thenRn_`
256 -- Make the default-method name
257 getModeRn `thenRn` \ mode ->
259 SourceMode -> -- Source class decl
260 newImplicitBinder (mkDefaultMethodOcc (rdrNameOcc op)) locn `thenRn` \ dm_name ->
261 returnRn (dm_name, op `elem` meth_rdr_names, emptyFVs)
264 -> -- Imported class that has a default method decl
265 -- See comments with tname, snames, above
266 lookupImplicitOccRn dm_rdr_name `thenRn` \ dm_name ->
267 returnRn (dm_name, explicit_dm, if explicit_dm then unitFV dm_name else emptyFVs)
268 -- An imported class decl for a class decl that had an explicit default
269 -- method, mentions, rather than defines,
270 -- the default method, so we must arrange to pull it in
271 ) `thenRn` \ (dm_name, final_explicit_dm, dm_fvs) ->
273 returnRn (ClassOpSig op_name dm_name final_explicit_dm new_ty locn, op_ty_fvs `plusFV` dm_fvs)
277 %*********************************************************
279 \subsection{Instance declarations}
281 %*********************************************************
284 rnDecl (InstD (InstDecl inst_ty mbinds uprags dfun_rdr_name src_loc))
285 = pushSrcLocRn src_loc $
286 rnHsSigType (text "an instance decl") inst_ty `thenRn` \ (inst_ty', inst_fvs) ->
288 inst_tyvars = case inst_ty' of
289 HsForAllTy (Just inst_tyvars) _ _ -> inst_tyvars
291 -- (Slightly strangely) the forall-d tyvars scope over
292 -- the method bindings too
295 -- Rename the bindings
296 -- NB meth_names can be qualified!
297 checkDupNames meth_doc meth_names `thenRn_`
298 extendTyVarEnvFVRn inst_tyvars (
300 ) `thenRn` \ (mbinds', meth_fvs) ->
302 binders = map fst (bagToList (collectMonoBinders mbinds'))
303 binder_set = mkNameSet binders
305 -- Rename the prags and signatures.
306 -- Note that the type variables are not in scope here,
307 -- so that instance Eq a => Eq (T a) where
308 -- {-# SPECIALISE instance Eq a => Eq (T [a]) #-}
311 -- But the (unqualified) method names are in scope
312 bindLocalNames binders (
313 renameSigs (okInstDclSig binder_set) uprags
314 ) `thenRn` \ (new_uprags, prag_fvs) ->
316 getModeRn `thenRn` \ mode ->
318 InterfaceMode -> lookupImplicitOccRn dfun_rdr_name `thenRn` \ dfun_name ->
319 returnRn (dfun_name, unitFV dfun_name)
320 SourceMode -> newDFunName (getDFunKey inst_ty') src_loc
321 `thenRn` \ dfun_name ->
322 returnRn (dfun_name, emptyFVs)
324 `thenRn` \ (dfun_name, dfun_fv) ->
326 -- The typechecker checks that all the bindings are for the right class.
327 returnRn (InstD (InstDecl inst_ty' mbinds' new_uprags dfun_name src_loc),
328 inst_fvs `plusFV` meth_fvs `plusFV` prag_fvs `plusFV` dfun_fv)
330 meth_doc = text "the bindings in an instance declaration"
331 meth_names = bagToList (collectMonoBinders mbinds)
334 %*********************************************************
336 \subsection{Default declarations}
338 %*********************************************************
341 rnDecl (DefD (DefaultDecl tys src_loc))
342 = pushSrcLocRn src_loc $
343 rnHsTypes doc_str tys `thenRn` \ (tys', fvs) ->
344 returnRn (DefD (DefaultDecl tys' src_loc), fvs)
346 doc_str = text "a `default' declaration"
349 %*********************************************************
351 \subsection{Foreign declarations}
353 %*********************************************************
356 rnDecl (ForD (ForeignDecl name imp_exp ty ext_nm cconv src_loc))
357 = pushSrcLocRn src_loc $
358 lookupOccRn name `thenRn` \ name' ->
362 lookupImplicitOccsRn [makeStablePtr_RDR, deRefStablePtr_RDR,
363 bindIO_RDR, returnIO_RDR]
365 lookupImplicitOccsRn [bindIO_RDR, returnIO_RDR] `thenRn` \ fvs ->
366 returnRn (addOneFV fvs name')
367 extra_fvs other = returnRn emptyFVs
369 checkRn (ok_ext_nm ext_nm) (badExtName ext_nm) `thenRn_`
371 extra_fvs imp_exp `thenRn` \ fvs1 ->
373 rnHsSigType fo_decl_msg ty `thenRn` \ (ty', fvs2) ->
374 returnRn (ForD (ForeignDecl name' imp_exp ty' ext_nm cconv src_loc),
377 fo_decl_msg = ptext SLIT("a foreign declaration")
378 isDyn = isDynamicExtName ext_nm
380 ok_ext_nm Dynamic = True
381 ok_ext_nm (ExtName nm (Just mb)) = isCLabelString nm && isCLabelString mb
382 ok_ext_nm (ExtName nm Nothing) = isCLabelString nm
385 %*********************************************************
389 %*********************************************************
392 rnDecl (RuleD (IfaceRule rule_name vars fn args rhs src_loc))
393 = pushSrcLocRn src_loc $
394 lookupOccRn fn `thenRn` \ fn' ->
395 rnCoreBndrs vars $ \ vars' ->
396 mapFvRn rnCoreExpr args `thenRn` \ (args', fvs1) ->
397 rnCoreExpr rhs `thenRn` \ (rhs', fvs2) ->
398 returnRn (RuleD (IfaceRule rule_name vars' fn' args' rhs' src_loc),
399 (fvs1 `plusFV` fvs2) `addOneFV` fn')
401 rnDecl (RuleD (IfaceRuleOut fn rule))
402 -- This one is used for BuiltInRules
403 -- The rule itself is already done, but the thing
404 -- to attach it to is not.
405 = lookupOccRn fn `thenRn` \ fn' ->
406 returnRn (RuleD (IfaceRuleOut fn' rule), unitFV fn')
408 rnDecl (RuleD (HsRule rule_name tvs vars lhs rhs src_loc))
410 pushSrcLocRn src_loc $
412 bindTyVarsFV2Rn doc (map UserTyVar sig_tvs) $ \ sig_tvs' _ ->
413 bindLocalsFVRn doc (map get_var vars) $ \ ids ->
414 mapFvRn rn_var (vars `zip` ids) `thenRn` \ (vars', fv_vars) ->
416 rnExpr lhs `thenRn` \ (lhs', fv_lhs) ->
417 rnExpr rhs `thenRn` \ (rhs', fv_rhs) ->
418 checkRn (validRuleLhs ids lhs')
419 (badRuleLhsErr rule_name lhs') `thenRn_`
421 bad_vars = [var | var <- ids, not (var `elemNameSet` fv_lhs)]
423 mapRn (addErrRn . badRuleVar rule_name) bad_vars `thenRn_`
424 returnRn (RuleD (HsRule rule_name sig_tvs' vars' lhs' rhs' src_loc),
425 fv_vars `plusFV` fv_lhs `plusFV` fv_rhs)
427 doc = text "the transformation rule" <+> ptext rule_name
428 sig_tvs = extractRuleBndrsTyVars vars
430 get_var (RuleBndr v) = v
431 get_var (RuleBndrSig v _) = v
433 rn_var (RuleBndr v, id) = returnRn (RuleBndr id, emptyFVs)
434 rn_var (RuleBndrSig v t, id) = rnHsType doc t `thenRn` \ (t', fvs) ->
435 returnRn (RuleBndrSig id t', fvs)
439 %*********************************************************
441 \subsection{Support code for type/data declarations}
443 %*********************************************************
446 rnDerivs :: Maybe [RdrName] -> RnMS (Maybe [Name], FreeVars)
448 rnDerivs Nothing -- derivs not specified
449 = returnRn (Nothing, emptyFVs)
452 = mapRn do_one clss `thenRn` \ clss' ->
453 returnRn (Just clss', mkNameSet clss')
455 do_one cls = lookupOccRn cls `thenRn` \ clas_name ->
456 checkRn (getUnique clas_name `elem` derivableClassKeys)
457 (derivingNonStdClassErr clas_name) `thenRn_`
462 conDeclName :: RdrNameConDecl -> (RdrName, SrcLoc)
463 conDeclName (ConDecl n _ _ _ _ l) = (n,l)
465 rnConDecl :: RdrNameConDecl -> RnMS (RenamedConDecl, FreeVars)
466 rnConDecl (ConDecl name wkr tvs cxt details locn)
467 = pushSrcLocRn locn $
468 checkConName name `thenRn_`
469 lookupBndrRn name `thenRn` \ new_name ->
471 mkImportedGlobalFromRdrName wkr `thenRn` \ new_wkr ->
472 -- See comments with ClassDecl
474 bindTyVarsFVRn doc tvs $ \ new_tyvars ->
475 rnContext doc cxt `thenRn` \ (new_context, cxt_fvs) ->
476 rnConDetails doc locn details `thenRn` \ (new_details, det_fvs) ->
477 returnRn (ConDecl new_name new_wkr new_tyvars new_context new_details locn,
478 cxt_fvs `plusFV` det_fvs)
480 doc = text "the definition of data constructor" <+> quotes (ppr name)
482 rnConDetails doc locn (VanillaCon tys)
483 = mapFvRn (rnBangTy doc) tys `thenRn` \ (new_tys, fvs) ->
484 returnRn (VanillaCon new_tys, fvs)
486 rnConDetails doc locn (InfixCon ty1 ty2)
487 = rnBangTy doc ty1 `thenRn` \ (new_ty1, fvs1) ->
488 rnBangTy doc ty2 `thenRn` \ (new_ty2, fvs2) ->
489 returnRn (InfixCon new_ty1 new_ty2, fvs1 `plusFV` fvs2)
491 rnConDetails doc locn (NewCon ty mb_field)
492 = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
493 rn_field mb_field `thenRn` \ new_mb_field ->
494 returnRn (NewCon new_ty new_mb_field, fvs)
496 rn_field Nothing = returnRn Nothing
498 lookupBndrRn f `thenRn` \ new_f ->
499 returnRn (Just new_f)
501 rnConDetails doc locn (RecCon fields)
502 = checkDupOrQualNames doc field_names `thenRn_`
503 mapFvRn (rnField doc) fields `thenRn` \ (new_fields, fvs) ->
504 returnRn (RecCon new_fields, fvs)
506 field_names = [(fld, locn) | (flds, _) <- fields, fld <- flds]
508 rnField doc (names, ty)
509 = mapRn lookupBndrRn names `thenRn` \ new_names ->
510 rnBangTy doc ty `thenRn` \ (new_ty, fvs) ->
511 returnRn ((new_names, new_ty), fvs)
513 rnBangTy doc (Banged ty)
514 = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
515 returnRn (Banged new_ty, fvs)
517 rnBangTy doc (Unbanged ty)
518 = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
519 returnRn (Unbanged new_ty, fvs)
521 rnBangTy doc (Unpacked ty)
522 = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
523 returnRn (Unpacked new_ty, fvs)
525 -- This data decl will parse OK
527 -- treating "a" as the constructor.
528 -- It is really hard to make the parser spot this malformation.
529 -- So the renamer has to check that the constructor is legal
531 -- We can get an operator as the constructor, even in the prefix form:
532 -- data T = :% Int Int
533 -- from interface files, which always print in prefix form
536 = checkRn (isRdrDataCon name)
541 %*********************************************************
543 \subsection{Support code to rename types}
545 %*********************************************************
548 rnHsSigType :: SDoc -> RdrNameHsType -> RnMS (RenamedHsType, FreeVars)
549 -- rnHsSigType is used for source-language type signatures,
550 -- which use *implicit* universal quantification.
551 rnHsSigType doc_str ty
552 = rnHsType (text "the type signature for" <+> doc_str) ty
554 ---------------------------------------
555 rnHsType :: SDoc -> RdrNameHsType -> RnMS (RenamedHsType, FreeVars)
557 rnHsType doc (HsForAllTy Nothing ctxt ty)
558 -- Implicit quantifiction in source code (no kinds on tyvars)
559 -- Given the signature C => T we universally quantify
560 -- over FV(T) \ {in-scope-tyvars}
561 = getLocalNameEnv `thenRn` \ name_env ->
563 mentioned_in_tau = extractHsTyRdrTyVars ty
564 mentioned_in_ctxt = extractHsCtxtRdrTyVars ctxt
565 mentioned = nub (mentioned_in_tau ++ mentioned_in_ctxt)
566 forall_tyvars = filter (not . (`elemFM` name_env)) mentioned
568 rnForAll doc (map UserTyVar forall_tyvars) ctxt ty
570 rnHsType doc (HsForAllTy (Just forall_tyvars) ctxt tau)
571 -- Explicit quantification.
572 -- Check that the forall'd tyvars are actually
573 -- mentioned in the type, and produce a warning if not
575 mentioned_in_tau = extractHsTyRdrTyVars tau
576 mentioned_in_ctxt = extractHsCtxtRdrTyVars ctxt
577 mentioned = nub (mentioned_in_tau ++ mentioned_in_ctxt)
578 forall_tyvar_names = hsTyVarNames forall_tyvars
580 -- Explicitly quantified but not mentioned in ctxt or tau
581 warn_guys = filter (`notElem` mentioned) forall_tyvar_names
583 mapRn_ (forAllWarn doc tau) warn_guys `thenRn_`
584 rnForAll doc forall_tyvars ctxt tau
586 rnHsType doc (HsTyVar tyvar)
587 = lookupOccRn tyvar `thenRn` \ tyvar' ->
588 returnRn (HsTyVar tyvar', unitFV tyvar')
590 rnHsType doc (HsFunTy ty1 ty2)
591 = rnHsType doc ty1 `thenRn` \ (ty1', fvs1) ->
592 -- Might find a for-all as the arg of a function type
593 rnHsType doc ty2 `thenRn` \ (ty2', fvs2) ->
594 -- Or as the result. This happens when reading Prelude.hi
595 -- when we find return :: forall m. Monad m -> forall a. a -> m a
596 returnRn (HsFunTy ty1' ty2', fvs1 `plusFV` fvs2)
598 rnHsType doc (HsListTy ty)
599 = rnHsType doc ty `thenRn` \ (ty', fvs) ->
600 returnRn (HsListTy ty', fvs `addOneFV` listTyCon_name)
602 -- Unboxed tuples are allowed to have poly-typed arguments. These
603 -- sometimes crop up as a result of CPR worker-wrappering dictionaries.
604 rnHsType doc (HsTupleTy (HsTupCon _ boxity) tys)
605 -- Don't do lookupOccRn, because this is built-in syntax
606 -- so it doesn't need to be in scope
607 = mapFvRn (rnHsType doc) tys `thenRn` \ (tys', fvs) ->
608 returnRn (HsTupleTy (HsTupCon n' boxity) tys', fvs `addOneFV` n')
610 n' = tupleTyCon_name boxity (length tys)
613 rnHsType doc (HsAppTy ty1 ty2)
614 = rnHsType doc ty1 `thenRn` \ (ty1', fvs1) ->
615 rnHsType doc ty2 `thenRn` \ (ty2', fvs2) ->
616 returnRn (HsAppTy ty1' ty2', fvs1 `plusFV` fvs2)
618 rnHsType doc (HsPredTy pred)
619 = rnPred doc pred `thenRn` \ (pred', fvs) ->
620 returnRn (HsPredTy pred', fvs)
622 rnHsType doc (HsUsgForAllTy uv_rdr ty)
623 = bindUVarRn doc uv_rdr $ \ uv_name ->
624 rnHsType doc ty `thenRn` \ (ty', fvs) ->
625 returnRn (HsUsgForAllTy uv_name ty',
628 rnHsType doc (HsUsgTy usg ty)
629 = newUsg usg `thenRn` \ (usg', usg_fvs) ->
630 rnHsType doc ty `thenRn` \ (ty', ty_fvs) ->
631 -- A for-all can occur inside a usage annotation
632 returnRn (HsUsgTy usg' ty',
633 usg_fvs `plusFV` ty_fvs)
635 newUsg usg = case usg of
636 HsUsOnce -> returnRn (HsUsOnce, emptyFVs)
637 HsUsMany -> returnRn (HsUsMany, emptyFVs)
638 HsUsVar uv_rdr -> lookupOccRn uv_rdr `thenRn` \ uv_name ->
639 returnRn (HsUsVar uv_name, emptyFVs)
641 rnHsTypes doc tys = mapFvRn (rnHsType doc) tys
645 -- We use lookupOcc here because this is interface file only stuff
646 -- and we need the workers...
647 rnHsTupCon (HsTupCon n boxity)
648 = lookupOccRn n `thenRn` \ n' ->
649 returnRn (HsTupCon n' boxity, unitFV n')
651 rnHsTupConWkr (HsTupCon n boxity)
652 -- Tuple construtors are for the *worker* of the tuple
653 -- Going direct saves needless messing about
654 = lookupOccRn (mkRdrNameWkr n) `thenRn` \ n' ->
655 returnRn (HsTupCon n' boxity, unitFV n')
659 -- Check that each constraint mentions at least one of the forall'd type variables
660 -- Since the forall'd type variables are a subset of the free tyvars
661 -- of the tau-type part, this guarantees that every constraint mentions
662 -- at least one of the free tyvars in ty
663 checkConstraints doc forall_tyvars tau_vars ctxt ty
664 = mapRn (checkPred doc forall_tyvars ty) ctxt `thenRn` \ maybe_ctxt' ->
665 returnRn (catMaybes maybe_ctxt')
666 -- Remove problem ones, to avoid duplicate error message.
668 checkPred doc forall_tyvars ty p@(HsPClass clas tys)
669 | not_univ = failWithRn Nothing (univErr doc p ty)
670 | otherwise = returnRn (Just p)
672 ct_vars = extractHsTysRdrTyVars tys
673 not_univ = -- At least one of the tyvars in each constraint must
674 -- be universally quantified. This restriction isn't in Hugs
675 not (any (`elem` forall_tyvars) ct_vars)
676 checkPred doc forall_tyvars ty p@(HsPIParam _ _)
679 rnForAll doc forall_tyvars ctxt ty
680 = bindTyVarsFVRn doc forall_tyvars $ \ new_tyvars ->
681 rnContext doc ctxt `thenRn` \ (new_ctxt, cxt_fvs) ->
682 rnHsType doc ty `thenRn` \ (new_ty, ty_fvs) ->
683 returnRn (mkHsForAllTy (Just new_tyvars) new_ctxt new_ty,
684 cxt_fvs `plusFV` ty_fvs)
688 rnContext :: SDoc -> RdrNameContext -> RnMS (RenamedContext, FreeVars)
690 = mapAndUnzipRn rn_pred ctxt `thenRn` \ (theta, fvs_s) ->
692 (_, dups) = removeDupsEq theta
693 -- We only have equality, not ordering
695 -- Check for duplicate assertions
696 -- If this isn't an error, then it ought to be:
697 mapRn (addWarnRn . dupClassAssertWarn theta) dups `thenRn_`
698 returnRn (theta, plusFVs fvs_s)
700 --Someone discovered that @CCallable@ and @CReturnable@
701 -- could be used in contexts such as:
702 -- foo :: CCallable a => a -> PrimIO Int
703 -- Doing this utterly wrecks the whole point of introducing these
704 -- classes so we specifically check that this isn't being done.
705 rn_pred pred = rnPred doc pred `thenRn` \ (pred', fvs)->
706 checkRn (not (bad_pred pred'))
707 (naughtyCCallContextErr pred') `thenRn_`
708 returnRn (pred', fvs)
710 bad_pred (HsPClass clas _) = getUnique clas `elem` cCallishClassKeys
711 bad_pred other = False
714 rnPred doc (HsPClass clas tys)
715 = lookupOccRn clas `thenRn` \ clas_name ->
716 rnHsTypes doc tys `thenRn` \ (tys', fvs) ->
717 returnRn (HsPClass clas_name tys', fvs `addOneFV` clas_name)
719 rnPred doc (HsPIParam n ty)
720 = getIPName n `thenRn` \ name ->
721 rnHsType doc ty `thenRn` \ (ty', fvs) ->
722 returnRn (HsPIParam name ty', fvs)
726 rnFds :: SDoc -> [FunDep RdrName] -> RnMS ([FunDep Name], FreeVars)
729 = mapAndUnzipRn rn_fds fds `thenRn` \ (theta, fvs_s) ->
730 returnRn (theta, plusFVs fvs_s)
733 = rnHsTyVars doc tys1 `thenRn` \ (tys1', fvs1) ->
734 rnHsTyVars doc tys2 `thenRn` \ (tys2', fvs2) ->
735 returnRn ((tys1', tys2'), fvs1 `plusFV` fvs2)
737 rnHsTyVars doc tvs = mapFvRn (rnHsTyvar doc) tvs
739 = lookupOccRn tyvar `thenRn` \ tyvar' ->
740 returnRn (tyvar', unitFV tyvar')
743 %*********************************************************
747 %*********************************************************
750 rnIdInfo (HsStrictness str) = returnRn (HsStrictness str, emptyFVs)
752 rnIdInfo (HsWorker worker)
753 = lookupOccRn worker `thenRn` \ worker' ->
754 returnRn (HsWorker worker', unitFV worker')
756 rnIdInfo (HsUnfold inline expr) = rnCoreExpr expr `thenRn` \ (expr', fvs) ->
757 returnRn (HsUnfold inline expr', fvs)
758 rnIdInfo (HsArity arity) = returnRn (HsArity arity, emptyFVs)
759 rnIdInfo (HsUpdate update) = returnRn (HsUpdate update, emptyFVs)
760 rnIdInfo HsNoCafRefs = returnRn (HsNoCafRefs, emptyFVs)
761 rnIdInfo HsCprInfo = returnRn (HsCprInfo, emptyFVs)
765 @UfCore@ expressions.
768 rnCoreExpr (UfType ty)
769 = rnHsType (text "unfolding type") ty `thenRn` \ (ty', fvs) ->
770 returnRn (UfType ty', fvs)
773 = lookupOccRn v `thenRn` \ v' ->
774 returnRn (UfVar v', unitFV v')
777 = returnRn (UfLit l, emptyFVs)
779 rnCoreExpr (UfLitLit l ty)
780 = rnHsType (text "litlit") ty `thenRn` \ (ty', fvs) ->
781 returnRn (UfLitLit l ty', fvs)
783 rnCoreExpr (UfCCall cc ty)
784 = rnHsType (text "ccall") ty `thenRn` \ (ty', fvs) ->
785 returnRn (UfCCall cc ty', fvs)
787 rnCoreExpr (UfTuple con args)
788 = rnHsTupConWkr con `thenRn` \ (con', fvs1) ->
789 mapFvRn rnCoreExpr args `thenRn` \ (args', fvs2) ->
790 returnRn (UfTuple con' args', fvs1 `plusFV` fvs2)
792 rnCoreExpr (UfApp fun arg)
793 = rnCoreExpr fun `thenRn` \ (fun', fv1) ->
794 rnCoreExpr arg `thenRn` \ (arg', fv2) ->
795 returnRn (UfApp fun' arg', fv1 `plusFV` fv2)
797 rnCoreExpr (UfCase scrut bndr alts)
798 = rnCoreExpr scrut `thenRn` \ (scrut', fvs1) ->
799 bindCoreLocalFVRn bndr ( \ bndr' ->
800 mapFvRn rnCoreAlt alts `thenRn` \ (alts', fvs2) ->
801 returnRn (UfCase scrut' bndr' alts', fvs2)
802 ) `thenRn` \ (case', fvs3) ->
803 returnRn (case', fvs1 `plusFV` fvs3)
805 rnCoreExpr (UfNote note expr)
806 = rnNote note `thenRn` \ (note', fvs1) ->
807 rnCoreExpr expr `thenRn` \ (expr', fvs2) ->
808 returnRn (UfNote note' expr', fvs1 `plusFV` fvs2)
810 rnCoreExpr (UfLam bndr body)
811 = rnCoreBndr bndr $ \ bndr' ->
812 rnCoreExpr body `thenRn` \ (body', fvs) ->
813 returnRn (UfLam bndr' body', fvs)
815 rnCoreExpr (UfLet (UfNonRec bndr rhs) body)
816 = rnCoreExpr rhs `thenRn` \ (rhs', fvs1) ->
817 rnCoreBndr bndr ( \ bndr' ->
818 rnCoreExpr body `thenRn` \ (body', fvs2) ->
819 returnRn (UfLet (UfNonRec bndr' rhs') body', fvs2)
820 ) `thenRn` \ (result, fvs3) ->
821 returnRn (result, fvs1 `plusFV` fvs3)
823 rnCoreExpr (UfLet (UfRec pairs) body)
824 = rnCoreBndrs bndrs $ \ bndrs' ->
825 mapFvRn rnCoreExpr rhss `thenRn` \ (rhss', fvs1) ->
826 rnCoreExpr body `thenRn` \ (body', fvs2) ->
827 returnRn (UfLet (UfRec (bndrs' `zip` rhss')) body', fvs1 `plusFV` fvs2)
829 (bndrs, rhss) = unzip pairs
833 rnCoreBndr (UfValBinder name ty) thing_inside
834 = rnHsType doc ty `thenRn` \ (ty', fvs1) ->
835 bindCoreLocalFVRn name ( \ name' ->
836 thing_inside (UfValBinder name' ty')
837 ) `thenRn` \ (result, fvs2) ->
838 returnRn (result, fvs1 `plusFV` fvs2)
840 doc = text "unfolding id"
842 rnCoreBndr (UfTyBinder name kind) thing_inside
843 = bindCoreLocalFVRn name $ \ name' ->
844 thing_inside (UfTyBinder name' kind)
846 rnCoreBndrs [] thing_inside = thing_inside []
847 rnCoreBndrs (b:bs) thing_inside = rnCoreBndr b $ \ name' ->
848 rnCoreBndrs bs $ \ names' ->
849 thing_inside (name':names')
853 rnCoreAlt (con, bndrs, rhs)
854 = rnUfCon con bndrs `thenRn` \ (con', fvs1) ->
855 bindCoreLocalsFVRn bndrs ( \ bndrs' ->
856 rnCoreExpr rhs `thenRn` \ (rhs', fvs2) ->
857 returnRn ((con', bndrs', rhs'), fvs2)
858 ) `thenRn` \ (result, fvs3) ->
859 returnRn (result, fvs1 `plusFV` fvs3)
862 = rnHsType (text "unfolding coerce") ty `thenRn` \ (ty', fvs) ->
863 returnRn (UfCoerce ty', fvs)
865 rnNote (UfSCC cc) = returnRn (UfSCC cc, emptyFVs)
866 rnNote UfInlineCall = returnRn (UfInlineCall, emptyFVs)
867 rnNote UfInlineMe = returnRn (UfInlineMe, emptyFVs)
871 = returnRn (UfDefault, emptyFVs)
873 rnUfCon (UfTupleAlt tup_con) bndrs
874 = rnHsTupCon tup_con `thenRn` \ (HsTupCon con' _, fvs) ->
875 returnRn (UfDataAlt con', fvs)
876 -- Makes the type checker a little easier
878 rnUfCon (UfDataAlt con) _
879 = lookupOccRn con `thenRn` \ con' ->
880 returnRn (UfDataAlt con', unitFV con')
882 rnUfCon (UfLitAlt lit) _
883 = returnRn (UfLitAlt lit, emptyFVs)
885 rnUfCon (UfLitLitAlt lit ty) _
886 = rnHsType (text "litlit") ty `thenRn` \ (ty', fvs) ->
887 returnRn (UfLitLitAlt lit ty', fvs)
890 %*********************************************************
892 \subsection{Rule shapes}
894 %*********************************************************
896 Check the shape of a transformation rule LHS. Currently
897 we only allow LHSs of the form @(f e1 .. en)@, where @f@ is
898 not one of the @forall@'d variables.
901 validRuleLhs foralls lhs
904 check (HsApp e1 e2) = check e1
905 check (HsVar v) | v `notElem` foralls = True
910 %*********************************************************
914 %*********************************************************
917 derivingNonStdClassErr clas
918 = hsep [ptext SLIT("non-standard class"), ppr clas, ptext SLIT("in deriving clause")]
920 classTyVarNotInOpTyErr clas_tyvar sig
921 = hang (hsep [ptext SLIT("Class type variable"),
922 quotes (ppr clas_tyvar),
923 ptext SLIT("does not appear in method signature")])
927 = hsep [ptext SLIT("Illegal data constructor name"), quotes (ppr name)]
929 forAllWarn doc ty tyvar
930 | not opt_WarnUnusedMatches = returnRn ()
932 = getModeRn `thenRn` \ mode ->
935 InterfaceMode -> returnRn () ; -- Don't warn of unused tyvars in interface files
936 -- unless DEBUG is on, in which case it is slightly
937 -- informative. They can arise from mkRhsTyLam,
938 #endif -- leading to (say) f :: forall a b. [b] -> [b]
942 sep [ptext SLIT("The universally quantified type variable") <+> quotes (ppr tyvar),
943 nest 4 (ptext SLIT("does not appear in the type") <+> quotes (ppr ty))]
945 (ptext SLIT("In") <+> doc))
948 forAllErr doc ty tyvar
950 sep [ptext SLIT("The constrained type variable") <+> quotes (ppr tyvar),
951 nest 4 (ptext SLIT("does not appear in the type") <+> quotes (ppr ty))]
953 (ptext SLIT("In") <+> doc))
955 univErr doc constraint ty
956 = sep [ptext SLIT("All of the type variable(s) in the constraint")
957 <+> quotes (ppr constraint)
958 <+> ptext SLIT("are already in scope"),
959 nest 4 (ptext SLIT("At least one must be universally quantified here"))
962 (ptext SLIT("In") <+> doc)
964 badRuleLhsErr name lhs
965 = sep [ptext SLIT("Rule") <+> ptext name <> colon,
966 nest 4 (ptext SLIT("Illegal left-hand side:") <+> ppr lhs)]
968 ptext SLIT("LHS must be of form (f e1 .. en) where f is not forall'd")
971 = sep [ptext SLIT("Rule") <+> ptext name <> colon,
972 ptext SLIT("Forall'd variable") <+> quotes (ppr var) <+>
973 ptext SLIT("does not appear on left hand side")]
975 badExtName :: ExtName -> Message
977 = sep [quotes (ppr ext_nm) <+> ptext SLIT("is not a valid C identifier")]
979 dupClassAssertWarn ctxt (assertion : dups)
980 = sep [hsep [ptext SLIT("Duplicate class assertion"),
981 quotes (ppr assertion),
982 ptext SLIT("in the context:")],
983 nest 4 (pprHsContext ctxt <+> ptext SLIT("..."))]
985 naughtyCCallContextErr (HsPClass clas _)
986 = sep [ptext SLIT("Can't use class") <+> quotes (ppr clas),
987 ptext SLIT("in a context")]