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 ( getTyVarName )
15 import RdrName ( RdrName, isRdrDataCon, rdrNameOcc, isRdrTyVar, mkRdrNameWkr )
16 import RdrHsSyn ( RdrNameContext, RdrNameHsType, RdrNameConDecl,
17 extractRuleBndrsTyVars, extractHsTyRdrTyVars, extractHsTysRdrTyVars
22 import RnBinds ( rnTopBinds, rnMethodBinds, renameSigs, unknownSigErr )
23 import RnEnv ( bindTyVarsRn, lookupBndrRn, lookupOccRn, getIPName,
24 lookupImplicitOccRn, lookupImplicitOccsRn,
25 bindLocalsRn, bindLocalRn, bindLocalsFVRn, bindUVarRn,
26 bindTyVarsFVRn, bindTyVarsFV2Rn, extendTyVarEnvFVRn,
27 bindCoreLocalFVRn, bindCoreLocalsFVRn,
28 checkDupOrQualNames, checkDupNames,
29 mkImportedGlobalName, mkImportedGlobalFromRdrName,
30 newDFunName, getDFunKey, newImplicitBinder,
31 FreeVars, emptyFVs, plusFV, plusFVs, unitFV, addOneFV, mapFvRn
35 import FunDeps ( oclose )
36 import Class ( FunDep )
38 import Name ( Name, OccName,
39 ExportFlag(..), Provenance(..),
40 nameOccName, NamedThing(..)
43 import OccName ( mkDefaultMethodOcc )
44 import BasicTypes ( TopLevelFlag(..) )
45 import FiniteMap ( elemFM )
46 import PrelInfo ( derivableClassKeys, cCallishClassKeys,
47 deRefStablePtr_RDR, makeStablePtr_RDR,
48 bindIO_RDR, returnIO_RDR
50 import Bag ( bagToList )
51 import List ( partition, nub )
53 import SrcLoc ( SrcLoc )
54 import CmdLineOpts ( opt_GlasgowExts, opt_WarnUnusedMatches ) -- Warn of unused for-all'd tyvars
55 import Unique ( Uniquable(..) )
56 import UniqFM ( lookupUFM )
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 = mkNameSet (map fst (bagToList (collectMonoBinders mbinds')))
304 -- Rename the prags and signatures.
305 -- Note that the type variables are not in scope here,
306 -- so that instance Eq a => Eq (T a) where
307 -- {-# SPECIALISE instance Eq a => Eq (T [a]) #-}
309 renameSigs (okInstDclSig binders) uprags `thenRn` \ (new_uprags, prag_fvs) ->
311 getModeRn `thenRn` \ mode ->
313 InterfaceMode -> lookupImplicitOccRn dfun_rdr_name `thenRn` \ dfun_name ->
314 returnRn (dfun_name, unitFV dfun_name)
315 SourceMode -> newDFunName (getDFunKey inst_ty') src_loc
316 `thenRn` \ dfun_name ->
317 returnRn (dfun_name, emptyFVs)
319 `thenRn` \ (dfun_name, dfun_fv) ->
321 -- The typechecker checks that all the bindings are for the right class.
322 returnRn (InstD (InstDecl inst_ty' mbinds' new_uprags dfun_name src_loc),
323 inst_fvs `plusFV` meth_fvs `plusFV` prag_fvs `plusFV` dfun_fv)
325 meth_doc = text "the bindings in an instance declaration"
326 meth_names = bagToList (collectMonoBinders mbinds)
329 %*********************************************************
331 \subsection{Default declarations}
333 %*********************************************************
336 rnDecl (DefD (DefaultDecl tys src_loc))
337 = pushSrcLocRn src_loc $
338 rnHsTypes doc_str tys `thenRn` \ (tys', fvs) ->
339 returnRn (DefD (DefaultDecl tys' src_loc), fvs)
341 doc_str = text "a `default' declaration"
344 %*********************************************************
346 \subsection{Foreign declarations}
348 %*********************************************************
351 rnDecl (ForD (ForeignDecl name imp_exp ty ext_nm cconv src_loc))
352 = pushSrcLocRn src_loc $
353 lookupOccRn name `thenRn` \ name' ->
356 | isDyn = lookupImplicitOccsRn [makeStablePtr_RDR, deRefStablePtr_RDR]
357 | otherwise = returnRn (unitFV name')
358 extra_fvs other = returnRn emptyFVs
360 checkRn (ok_ext_nm ext_nm) (badExtName ext_nm) `thenRn_`
362 lookupImplicitOccsRn [bindIO_RDR, returnIO_RDR] `thenRn` \ fvs1 ->
363 extra_fvs imp_exp `thenRn` \ fvs2 ->
365 rnHsSigType fo_decl_msg ty `thenRn` \ (ty', fvs3) ->
366 returnRn (ForD (ForeignDecl name' imp_exp ty' ext_nm cconv src_loc),
367 fvs1 `plusFV` fvs2 `plusFV` fvs3)
369 fo_decl_msg = ptext SLIT("a foreign declaration")
370 isDyn = isDynamicExtName ext_nm
372 ok_ext_nm Dynamic = True
373 ok_ext_nm (ExtName nm (Just mb)) = isCLabelString nm && isCLabelString mb
374 ok_ext_nm (ExtName nm Nothing) = isCLabelString nm
377 %*********************************************************
381 %*********************************************************
384 rnDecl (RuleD (IfaceRule rule_name vars fn args rhs src_loc))
385 = pushSrcLocRn src_loc $
386 lookupOccRn fn `thenRn` \ fn' ->
387 rnCoreBndrs vars $ \ vars' ->
388 mapFvRn rnCoreExpr args `thenRn` \ (args', fvs1) ->
389 rnCoreExpr rhs `thenRn` \ (rhs', fvs2) ->
390 returnRn (RuleD (IfaceRule rule_name vars' fn' args' rhs' src_loc),
391 (fvs1 `plusFV` fvs2) `addOneFV` fn')
393 rnDecl (RuleD (IfaceRuleOut fn rule))
394 -- This one is used for BuiltInRules
395 -- The rule itself is already done, but the thing
396 -- to attach it to is not.
397 = lookupOccRn fn `thenRn` \ fn' ->
398 returnRn (RuleD (IfaceRuleOut fn' rule), unitFV fn')
400 rnDecl (RuleD (HsRule rule_name tvs vars lhs rhs src_loc))
402 pushSrcLocRn src_loc $
404 bindTyVarsFV2Rn doc (map UserTyVar sig_tvs) $ \ sig_tvs' _ ->
405 bindLocalsFVRn doc (map get_var vars) $ \ ids ->
406 mapFvRn rn_var (vars `zip` ids) `thenRn` \ (vars', fv_vars) ->
408 rnExpr lhs `thenRn` \ (lhs', fv_lhs) ->
409 rnExpr rhs `thenRn` \ (rhs', fv_rhs) ->
410 checkRn (validRuleLhs ids lhs')
411 (badRuleLhsErr rule_name lhs') `thenRn_`
413 bad_vars = [var | var <- ids, not (var `elemNameSet` fv_lhs)]
415 mapRn (addErrRn . badRuleVar rule_name) bad_vars `thenRn_`
416 returnRn (RuleD (HsRule rule_name sig_tvs' vars' lhs' rhs' src_loc),
417 fv_vars `plusFV` fv_lhs `plusFV` fv_rhs)
419 doc = text "the transformation rule" <+> ptext rule_name
420 sig_tvs = extractRuleBndrsTyVars vars
422 get_var (RuleBndr v) = v
423 get_var (RuleBndrSig v _) = v
425 rn_var (RuleBndr v, id) = returnRn (RuleBndr id, emptyFVs)
426 rn_var (RuleBndrSig v t, id) = rnHsType doc t `thenRn` \ (t', fvs) ->
427 returnRn (RuleBndrSig id t', fvs)
431 %*********************************************************
433 \subsection{Support code for type/data declarations}
435 %*********************************************************
438 rnDerivs :: Maybe [RdrName] -> RnMS (Maybe [Name], FreeVars)
440 rnDerivs Nothing -- derivs not specified
441 = returnRn (Nothing, emptyFVs)
444 = mapRn do_one clss `thenRn` \ clss' ->
445 returnRn (Just clss', mkNameSet clss')
447 do_one cls = lookupOccRn cls `thenRn` \ clas_name ->
448 checkRn (getUnique clas_name `elem` derivableClassKeys)
449 (derivingNonStdClassErr clas_name) `thenRn_`
454 conDeclName :: RdrNameConDecl -> (RdrName, SrcLoc)
455 conDeclName (ConDecl n _ _ _ _ l) = (n,l)
457 rnConDecl :: RdrNameConDecl -> RnMS (RenamedConDecl, FreeVars)
458 rnConDecl (ConDecl name wkr tvs cxt details locn)
459 = pushSrcLocRn locn $
460 checkConName name `thenRn_`
461 lookupBndrRn name `thenRn` \ new_name ->
463 mkImportedGlobalFromRdrName wkr `thenRn` \ new_wkr ->
464 -- See comments with ClassDecl
466 bindTyVarsFVRn doc tvs $ \ new_tyvars ->
467 rnContext doc cxt `thenRn` \ (new_context, cxt_fvs) ->
468 rnConDetails doc locn details `thenRn` \ (new_details, det_fvs) ->
469 returnRn (ConDecl new_name new_wkr new_tyvars new_context new_details locn,
470 cxt_fvs `plusFV` det_fvs)
472 doc = text "the definition of data constructor" <+> quotes (ppr name)
474 rnConDetails doc locn (VanillaCon tys)
475 = mapFvRn (rnBangTy doc) tys `thenRn` \ (new_tys, fvs) ->
476 returnRn (VanillaCon new_tys, fvs)
478 rnConDetails doc locn (InfixCon ty1 ty2)
479 = rnBangTy doc ty1 `thenRn` \ (new_ty1, fvs1) ->
480 rnBangTy doc ty2 `thenRn` \ (new_ty2, fvs2) ->
481 returnRn (InfixCon new_ty1 new_ty2, fvs1 `plusFV` fvs2)
483 rnConDetails doc locn (NewCon ty mb_field)
484 = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
485 rn_field mb_field `thenRn` \ new_mb_field ->
486 returnRn (NewCon new_ty new_mb_field, fvs)
488 rn_field Nothing = returnRn Nothing
490 lookupBndrRn f `thenRn` \ new_f ->
491 returnRn (Just new_f)
493 rnConDetails doc locn (RecCon fields)
494 = checkDupOrQualNames doc field_names `thenRn_`
495 mapFvRn (rnField doc) fields `thenRn` \ (new_fields, fvs) ->
496 returnRn (RecCon new_fields, fvs)
498 field_names = [(fld, locn) | (flds, _) <- fields, fld <- flds]
500 rnField doc (names, ty)
501 = mapRn lookupBndrRn names `thenRn` \ new_names ->
502 rnBangTy doc ty `thenRn` \ (new_ty, fvs) ->
503 returnRn ((new_names, new_ty), fvs)
505 rnBangTy doc (Banged ty)
506 = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
507 returnRn (Banged new_ty, fvs)
509 rnBangTy doc (Unbanged ty)
510 = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
511 returnRn (Unbanged new_ty, fvs)
513 rnBangTy doc (Unpacked ty)
514 = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
515 returnRn (Unpacked new_ty, fvs)
517 -- This data decl will parse OK
519 -- treating "a" as the constructor.
520 -- It is really hard to make the parser spot this malformation.
521 -- So the renamer has to check that the constructor is legal
523 -- We can get an operator as the constructor, even in the prefix form:
524 -- data T = :% Int Int
525 -- from interface files, which always print in prefix form
528 = checkRn (isRdrDataCon name)
533 %*********************************************************
535 \subsection{Support code to rename types}
537 %*********************************************************
540 rnHsSigType :: SDoc -> RdrNameHsType -> RnMS (RenamedHsType, FreeVars)
541 -- rnHsSigType is used for source-language type signatures,
542 -- which use *implicit* universal quantification.
543 rnHsSigType doc_str ty
544 = rnHsType (text "the type signature for" <+> doc_str) ty
546 ---------------------------------------
547 rnHsType :: SDoc -> RdrNameHsType -> RnMS (RenamedHsType, FreeVars)
549 rnHsType doc (HsForAllTy Nothing ctxt ty)
550 -- Implicit quantifiction in source code (no kinds on tyvars)
551 -- Given the signature C => T we universally quantify
552 -- over FV(T) \ {in-scope-tyvars}
553 = getLocalNameEnv `thenRn` \ name_env ->
555 mentioned_in_tau = extractHsTyRdrTyVars ty
556 forall_tyvars = filter (not . (`elemFM` name_env)) mentioned_in_tau
558 checkConstraints doc forall_tyvars mentioned_in_tau ctxt ty `thenRn` \ ctxt' ->
559 rnForAll doc (map UserTyVar forall_tyvars) ctxt' ty
561 rnHsType doc (HsForAllTy (Just forall_tyvars) ctxt tau)
562 -- Explicit quantification.
563 -- Check that the forall'd tyvars are a subset of the
564 -- free tyvars in the tau-type part
565 -- That's only a warning... unless the tyvar is constrained by a
566 -- context in which case it's an error
568 mentioned_in_tau = extractHsTyRdrTyVars tau
569 mentioned_in_ctxt = nub [tv | p <- ctxt,
571 tv <- extractHsTyRdrTyVars ty]
572 tys_of_pred (HsPClass clas tys) = tys
573 tys_of_pred (HsPIParam n ty) = [ty]
575 dubious_guys = filter (`notElem` mentioned_in_tau) forall_tyvar_names
576 -- dubious = explicitly quantified but not mentioned in tau type
578 (bad_guys, warn_guys) = partition (`elem` mentioned_in_ctxt) dubious_guys
579 -- bad = explicitly quantified and constrained, but not mentioned in tau
580 -- warn = explicitly quantified but not mentioned in ctxt or tau
582 forall_tyvar_names = map getTyVarName forall_tyvars
584 -- mapRn_ (forAllErr doc tau) bad_guys `thenRn_`
585 mapRn_ (forAllWarn doc tau) warn_guys `thenRn_`
586 checkConstraints doc forall_tyvar_names mentioned_in_tau ctxt tau `thenRn` \ ctxt' ->
587 rnForAll doc forall_tyvars ctxt' tau
589 rnHsType doc (HsTyVar tyvar)
590 = lookupOccRn tyvar `thenRn` \ tyvar' ->
591 returnRn (HsTyVar tyvar', unitFV tyvar')
593 rnHsType doc (HsFunTy ty1 ty2)
594 = rnHsType doc ty1 `thenRn` \ (ty1', fvs1) ->
595 -- Might find a for-all as the arg of a function type
596 rnHsType doc ty2 `thenRn` \ (ty2', fvs2) ->
597 -- Or as the result. This happens when reading Prelude.hi
598 -- when we find return :: forall m. Monad m -> forall a. a -> m a
599 returnRn (HsFunTy ty1' ty2', fvs1 `plusFV` fvs2)
601 rnHsType doc (HsListTy ty)
602 = rnHsType doc ty `thenRn` \ (ty', fvs) ->
603 returnRn (HsListTy ty', fvs `addOneFV` listTyCon_name)
605 -- Unboxed tuples are allowed to have poly-typed arguments. These
606 -- sometimes crop up as a result of CPR worker-wrappering dictionaries.
607 rnHsType doc (HsTupleTy (HsTupCon _ boxity) tys)
608 -- Don't do lookupOccRn, because this is built-in syntax
609 -- so it doesn't need to be in scope
610 = mapFvRn (rnHsType doc) tys `thenRn` \ (tys', fvs) ->
611 returnRn (HsTupleTy (HsTupCon n' boxity) tys', fvs `addOneFV` n')
613 n' = tupleTyCon_name boxity (length tys)
616 rnHsType doc (HsAppTy ty1 ty2)
617 = rnHsType doc ty1 `thenRn` \ (ty1', fvs1) ->
618 rnHsType doc ty2 `thenRn` \ (ty2', fvs2) ->
619 returnRn (HsAppTy ty1' ty2', fvs1 `plusFV` fvs2)
621 rnHsType doc (HsPredTy pred)
622 = rnPred doc pred `thenRn` \ (pred', fvs) ->
623 returnRn (HsPredTy pred', fvs)
625 rnHsType doc (HsUsgForAllTy uv_rdr ty)
626 = bindUVarRn doc uv_rdr $ \ uv_name ->
627 rnHsType doc ty `thenRn` \ (ty', fvs) ->
628 returnRn (HsUsgForAllTy uv_name ty',
631 rnHsType doc (HsUsgTy usg ty)
632 = newUsg usg `thenRn` \ (usg', usg_fvs) ->
633 rnHsType doc ty `thenRn` \ (ty', ty_fvs) ->
634 -- A for-all can occur inside a usage annotation
635 returnRn (HsUsgTy usg' ty',
636 usg_fvs `plusFV` ty_fvs)
638 newUsg usg = case usg of
639 HsUsOnce -> returnRn (HsUsOnce, emptyFVs)
640 HsUsMany -> returnRn (HsUsMany, emptyFVs)
641 HsUsVar uv_rdr -> lookupOccRn uv_rdr `thenRn` \ uv_name ->
642 returnRn (HsUsVar uv_name, emptyFVs)
644 rnHsTypes doc tys = mapFvRn (rnHsType doc) tys
648 -- We use lookupOcc here because this is interface file only stuff
649 -- and we need the workers...
650 rnHsTupCon (HsTupCon n boxity)
651 = lookupOccRn n `thenRn` \ n' ->
652 returnRn (HsTupCon n' boxity, unitFV n')
654 rnHsTupConWkr (HsTupCon n boxity)
655 -- Tuple construtors are for the *worker* of the tuple
656 -- Going direct saves needless messing about
657 = lookupOccRn (mkRdrNameWkr n) `thenRn` \ n' ->
658 returnRn (HsTupCon n' boxity, unitFV n')
662 -- Check that each constraint mentions at least one of the forall'd type variables
663 -- Since the forall'd type variables are a subset of the free tyvars
664 -- of the tau-type part, this guarantees that every constraint mentions
665 -- at least one of the free tyvars in ty
666 checkConstraints doc forall_tyvars tau_vars ctxt ty
667 = mapRn (checkPred doc forall_tyvars ty) ctxt `thenRn` \ maybe_ctxt' ->
668 returnRn (catMaybes maybe_ctxt')
669 -- Remove problem ones, to avoid duplicate error message.
671 checkPred doc forall_tyvars ty p@(HsPClass clas tys)
672 | not_univ = failWithRn Nothing (univErr doc p ty)
673 | otherwise = returnRn (Just p)
675 ct_vars = extractHsTysRdrTyVars tys
676 not_univ = -- At least one of the tyvars in each constraint must
677 -- be universally quantified. This restriction isn't in Hugs
678 not (any (`elem` forall_tyvars) ct_vars)
679 checkPred doc forall_tyvars ty p@(HsPIParam _ _)
682 rnForAll doc forall_tyvars ctxt ty
683 = bindTyVarsFVRn doc forall_tyvars $ \ new_tyvars ->
684 rnContext doc ctxt `thenRn` \ (new_ctxt, cxt_fvs) ->
685 rnHsType doc ty `thenRn` \ (new_ty, ty_fvs) ->
686 returnRn (mkHsForAllTy (Just new_tyvars) new_ctxt new_ty,
687 cxt_fvs `plusFV` ty_fvs)
691 rnContext :: SDoc -> RdrNameContext -> RnMS (RenamedContext, FreeVars)
693 = mapAndUnzipRn rn_pred ctxt `thenRn` \ (theta, fvs_s) ->
695 (_, dups) = removeDupsEq theta
696 -- We only have equality, not ordering
698 -- Check for duplicate assertions
699 -- If this isn't an error, then it ought to be:
700 mapRn (addWarnRn . dupClassAssertWarn theta) dups `thenRn_`
701 returnRn (theta, plusFVs fvs_s)
703 --Someone discovered that @CCallable@ and @CReturnable@
704 -- could be used in contexts such as:
705 -- foo :: CCallable a => a -> PrimIO Int
706 -- Doing this utterly wrecks the whole point of introducing these
707 -- classes so we specifically check that this isn't being done.
708 rn_pred pred = rnPred doc pred `thenRn` \ (pred', fvs)->
709 checkRn (not (bad_pred pred'))
710 (naughtyCCallContextErr pred') `thenRn_`
711 returnRn (pred', fvs)
713 bad_pred (HsPClass clas _) = getUnique clas `elem` cCallishClassKeys
714 bad_pred other = False
717 rnPred doc (HsPClass clas tys)
718 = lookupOccRn clas `thenRn` \ clas_name ->
719 rnHsTypes doc tys `thenRn` \ (tys', fvs) ->
720 returnRn (HsPClass clas_name tys', fvs `addOneFV` clas_name)
722 rnPred doc (HsPIParam n ty)
723 = getIPName n `thenRn` \ name ->
724 rnHsType doc ty `thenRn` \ (ty', fvs) ->
725 returnRn (HsPIParam name ty', fvs)
729 rnFds :: SDoc -> [FunDep RdrName] -> RnMS ([FunDep Name], FreeVars)
732 = mapAndUnzipRn rn_fds fds `thenRn` \ (theta, fvs_s) ->
733 returnRn (theta, plusFVs fvs_s)
736 = rnHsTyVars doc tys1 `thenRn` \ (tys1', fvs1) ->
737 rnHsTyVars doc tys2 `thenRn` \ (tys2', fvs2) ->
738 returnRn ((tys1', tys2'), fvs1 `plusFV` fvs2)
740 rnHsTyVars doc tvs = mapFvRn (rnHsTyvar doc) tvs
742 = lookupOccRn tyvar `thenRn` \ tyvar' ->
743 returnRn (tyvar', unitFV tyvar')
746 %*********************************************************
750 %*********************************************************
753 rnIdInfo (HsStrictness str) = returnRn (HsStrictness str, emptyFVs)
755 rnIdInfo (HsWorker worker)
756 = lookupOccRn worker `thenRn` \ worker' ->
757 returnRn (HsWorker worker', unitFV worker')
759 rnIdInfo (HsUnfold inline expr) = rnCoreExpr expr `thenRn` \ (expr', fvs) ->
760 returnRn (HsUnfold inline expr', fvs)
761 rnIdInfo (HsArity arity) = returnRn (HsArity arity, emptyFVs)
762 rnIdInfo (HsUpdate update) = returnRn (HsUpdate update, emptyFVs)
763 rnIdInfo HsNoCafRefs = returnRn (HsNoCafRefs, emptyFVs)
764 rnIdInfo HsCprInfo = returnRn (HsCprInfo, emptyFVs)
768 @UfCore@ expressions.
771 rnCoreExpr (UfType ty)
772 = rnHsType (text "unfolding type") ty `thenRn` \ (ty', fvs) ->
773 returnRn (UfType ty', fvs)
776 = lookupOccRn v `thenRn` \ v' ->
777 returnRn (UfVar v', unitFV v')
780 = returnRn (UfLit l, emptyFVs)
782 rnCoreExpr (UfLitLit l ty)
783 = rnHsType (text "litlit") ty `thenRn` \ (ty', fvs) ->
784 returnRn (UfLitLit l ty', fvs)
786 rnCoreExpr (UfCCall cc ty)
787 = rnHsType (text "ccall") ty `thenRn` \ (ty', fvs) ->
788 returnRn (UfCCall cc ty', fvs)
790 rnCoreExpr (UfTuple con args)
791 = rnHsTupConWkr con `thenRn` \ (con', fvs1) ->
792 mapFvRn rnCoreExpr args `thenRn` \ (args', fvs2) ->
793 returnRn (UfTuple con' args', fvs1 `plusFV` fvs2)
795 rnCoreExpr (UfApp fun arg)
796 = rnCoreExpr fun `thenRn` \ (fun', fv1) ->
797 rnCoreExpr arg `thenRn` \ (arg', fv2) ->
798 returnRn (UfApp fun' arg', fv1 `plusFV` fv2)
800 rnCoreExpr (UfCase scrut bndr alts)
801 = rnCoreExpr scrut `thenRn` \ (scrut', fvs1) ->
802 bindCoreLocalFVRn bndr ( \ bndr' ->
803 mapFvRn rnCoreAlt alts `thenRn` \ (alts', fvs2) ->
804 returnRn (UfCase scrut' bndr' alts', fvs2)
805 ) `thenRn` \ (case', fvs3) ->
806 returnRn (case', fvs1 `plusFV` fvs3)
808 rnCoreExpr (UfNote note expr)
809 = rnNote note `thenRn` \ (note', fvs1) ->
810 rnCoreExpr expr `thenRn` \ (expr', fvs2) ->
811 returnRn (UfNote note' expr', fvs1 `plusFV` fvs2)
813 rnCoreExpr (UfLam bndr body)
814 = rnCoreBndr bndr $ \ bndr' ->
815 rnCoreExpr body `thenRn` \ (body', fvs) ->
816 returnRn (UfLam bndr' body', fvs)
818 rnCoreExpr (UfLet (UfNonRec bndr rhs) body)
819 = rnCoreExpr rhs `thenRn` \ (rhs', fvs1) ->
820 rnCoreBndr bndr ( \ bndr' ->
821 rnCoreExpr body `thenRn` \ (body', fvs2) ->
822 returnRn (UfLet (UfNonRec bndr' rhs') body', fvs2)
823 ) `thenRn` \ (result, fvs3) ->
824 returnRn (result, fvs1 `plusFV` fvs3)
826 rnCoreExpr (UfLet (UfRec pairs) body)
827 = rnCoreBndrs bndrs $ \ bndrs' ->
828 mapFvRn rnCoreExpr rhss `thenRn` \ (rhss', fvs1) ->
829 rnCoreExpr body `thenRn` \ (body', fvs2) ->
830 returnRn (UfLet (UfRec (bndrs' `zip` rhss')) body', fvs1 `plusFV` fvs2)
832 (bndrs, rhss) = unzip pairs
836 rnCoreBndr (UfValBinder name ty) thing_inside
837 = rnHsType doc ty `thenRn` \ (ty', fvs1) ->
838 bindCoreLocalFVRn name ( \ name' ->
839 thing_inside (UfValBinder name' ty')
840 ) `thenRn` \ (result, fvs2) ->
841 returnRn (result, fvs1 `plusFV` fvs2)
843 doc = text "unfolding id"
845 rnCoreBndr (UfTyBinder name kind) thing_inside
846 = bindCoreLocalFVRn name $ \ name' ->
847 thing_inside (UfTyBinder name' kind)
849 rnCoreBndrs [] thing_inside = thing_inside []
850 rnCoreBndrs (b:bs) thing_inside = rnCoreBndr b $ \ name' ->
851 rnCoreBndrs bs $ \ names' ->
852 thing_inside (name':names')
856 rnCoreAlt (con, bndrs, rhs)
857 = rnUfCon con bndrs `thenRn` \ (con', fvs1) ->
858 bindCoreLocalsFVRn bndrs ( \ bndrs' ->
859 rnCoreExpr rhs `thenRn` \ (rhs', fvs2) ->
860 returnRn ((con', bndrs', rhs'), fvs2)
861 ) `thenRn` \ (result, fvs3) ->
862 returnRn (result, fvs1 `plusFV` fvs3)
865 = rnHsType (text "unfolding coerce") ty `thenRn` \ (ty', fvs) ->
866 returnRn (UfCoerce ty', fvs)
868 rnNote (UfSCC cc) = returnRn (UfSCC cc, emptyFVs)
869 rnNote UfInlineCall = returnRn (UfInlineCall, emptyFVs)
870 rnNote UfInlineMe = returnRn (UfInlineMe, emptyFVs)
874 = returnRn (UfDefault, emptyFVs)
876 rnUfCon (UfTupleAlt tup_con) bndrs
877 = rnHsTupCon tup_con `thenRn` \ (HsTupCon con' _, fvs) ->
878 returnRn (UfDataAlt con', fvs)
879 -- Makes the type checker a little easier
881 rnUfCon (UfDataAlt con) _
882 = lookupOccRn con `thenRn` \ con' ->
883 returnRn (UfDataAlt con', unitFV con')
885 rnUfCon (UfLitAlt lit) _
886 = returnRn (UfLitAlt lit, emptyFVs)
888 rnUfCon (UfLitLitAlt lit ty) _
889 = rnHsType (text "litlit") ty `thenRn` \ (ty', fvs) ->
890 returnRn (UfLitLitAlt lit ty', fvs)
893 %*********************************************************
895 \subsection{Rule shapes}
897 %*********************************************************
899 Check the shape of a transformation rule LHS. Currently
900 we only allow LHSs of the form @(f e1 .. en)@, where @f@ is
901 not one of the @forall@'d variables.
904 validRuleLhs foralls lhs
907 check (HsApp e1 e2) = check e1
908 check (HsVar v) | v `notElem` foralls = True
913 %*********************************************************
917 %*********************************************************
920 derivingNonStdClassErr clas
921 = hsep [ptext SLIT("non-standard class"), ppr clas, ptext SLIT("in deriving clause")]
923 classTyVarNotInOpTyErr clas_tyvar sig
924 = hang (hsep [ptext SLIT("Class type variable"),
925 quotes (ppr clas_tyvar),
926 ptext SLIT("does not appear in method signature")])
930 = hsep [ptext SLIT("Illegal data constructor name"), quotes (ppr name)]
932 forAllWarn doc ty tyvar
933 | not opt_WarnUnusedMatches = returnRn ()
935 = getModeRn `thenRn` \ mode ->
938 InterfaceMode -> returnRn () ; -- Don't warn of unused tyvars in interface files
939 -- unless DEBUG is on, in which case it is slightly
940 -- informative. They can arise from mkRhsTyLam,
941 #endif -- leading to (say) f :: forall a b. [b] -> [b]
945 sep [ptext SLIT("The universally quantified type variable") <+> quotes (ppr tyvar),
946 nest 4 (ptext SLIT("does not appear in the type") <+> quotes (ppr ty))]
948 (ptext SLIT("In") <+> doc))
951 forAllErr doc ty tyvar
953 sep [ptext SLIT("The constrained type variable") <+> quotes (ppr tyvar),
954 nest 4 (ptext SLIT("does not appear in the type") <+> quotes (ppr ty))]
956 (ptext SLIT("In") <+> doc))
958 univErr doc constraint ty
959 = sep [ptext SLIT("All of the type variable(s) in the constraint")
960 <+> quotes (ppr constraint)
961 <+> ptext SLIT("are already in scope"),
962 nest 4 (ptext SLIT("At least one must be universally quantified here"))
965 (ptext SLIT("In") <+> doc)
967 ambigErr doc constraint ty
968 = sep [ptext SLIT("Ambiguous constraint") <+> quotes (ppr constraint),
969 nest 4 (ptext SLIT("in the type:") <+> ppr ty),
970 nest 4 (ptext SLIT("Each forall-d type variable mentioned by the constraint must appear after the =>."))]
972 (ptext SLIT("In") <+> doc)
974 badRuleLhsErr name lhs
975 = sep [ptext SLIT("Rule") <+> ptext name <> colon,
976 nest 4 (ptext SLIT("Illegal left-hand side:") <+> ppr lhs)]
978 ptext SLIT("LHS must be of form (f e1 .. en) where f is not forall'd")
981 = sep [ptext SLIT("Rule") <+> ptext name <> colon,
982 ptext SLIT("Forall'd variable") <+> quotes (ppr var) <+>
983 ptext SLIT("does not appear on left hand side")]
985 badExtName :: ExtName -> Message
987 = sep [quotes (ppr ext_nm) <+> ptext SLIT("is not a valid C identifier")]
989 dupClassAssertWarn ctxt (assertion : dups)
990 = sep [hsep [ptext SLIT("Duplicate class assertion"),
991 quotes (ppr assertion),
992 ptext SLIT("in the context:")],
993 nest 4 (ppr ctxt <+> ptext SLIT("..."))]
995 naughtyCCallContextErr (HsPClass clas _)
996 = sep [ptext SLIT("Can't use class") <+> quotes (ppr clas),
997 ptext SLIT("in a context")]