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, bindIO_RDR
49 import Bag ( bagToList )
50 import List ( partition, nub )
52 import SrcLoc ( SrcLoc )
53 import CmdLineOpts ( opt_GlasgowExts, opt_WarnUnusedMatches ) -- Warn of unused for-all'd tyvars
54 import Unique ( Uniquable(..) )
55 import UniqFM ( lookupUFM )
56 import ErrUtils ( Message )
57 import CStrings ( isCLabelString )
58 import Maybes ( maybeToBool, catMaybes )
62 @rnDecl@ `renames' declarations.
63 It simultaneously performs dependency analysis and precedence parsing.
64 It also does the following error checks:
67 Checks that tyvars are used properly. This includes checking
68 for undefined tyvars, and tyvars in contexts that are ambiguous.
69 (Some of this checking has now been moved to module @TcMonoType@,
70 since we don't have functional dependency information at this point.)
72 Checks that all variable occurences are defined.
74 Checks the @(..)@ etc constraints in the export list.
78 %*********************************************************
80 \subsection{Value declarations}
82 %*********************************************************
85 rnSourceDecls :: [RdrNameHsDecl] -> RnMS ([RenamedHsDecl], FreeVars)
86 -- The decls get reversed, but that's ok
89 = go emptyFVs [] decls
91 -- Fixity and deprecations have been dealt with already; ignore them
92 go fvs ds' [] = returnRn (ds', fvs)
93 go fvs ds' (FixD _:ds) = go fvs ds' ds
94 go fvs ds' (DeprecD _:ds) = go fvs ds' ds
95 go fvs ds' (d:ds) = rnDecl d `thenRn` \(d', fvs') ->
96 go (fvs `plusFV` fvs') (d':ds') ds
100 %*********************************************************
102 \subsection{Value declarations}
104 %*********************************************************
107 -- rnDecl does all the work
108 rnDecl :: RdrNameHsDecl -> RnMS (RenamedHsDecl, FreeVars)
110 rnDecl (ValD binds) = rnTopBinds binds `thenRn` \ (new_binds, fvs) ->
111 returnRn (ValD new_binds, fvs)
114 rnDecl (SigD (IfaceSig name ty id_infos loc))
116 mkImportedGlobalFromRdrName name `thenRn` \ name' ->
117 rnHsType doc_str ty `thenRn` \ (ty',fvs1) ->
118 mapFvRn rnIdInfo id_infos `thenRn` \ (id_infos', fvs2) ->
119 returnRn (SigD (IfaceSig name' ty' id_infos' loc), fvs1 `plusFV` fvs2)
121 doc_str = text "the interface signature for" <+> quotes (ppr name)
124 %*********************************************************
126 \subsection{Type declarations}
128 %*********************************************************
130 @rnTyDecl@ uses the `global name function' to create a new type
131 declaration in which local names have been replaced by their original
132 names, reporting any unknown names.
134 Renaming type variables is a pain. Because they now contain uniques,
135 it is necessary to pass in an association list which maps a parsed
136 tyvar to its @Name@ representation.
137 In some cases (type signatures of values),
138 it is even necessary to go over the type first
139 in order to get the set of tyvars used by it, make an assoc list,
140 and then go over it again to rename the tyvars!
141 However, we can also do some scoping checks at the same time.
144 rnDecl (TyClD (TyData new_or_data context tycon tyvars condecls nconstrs derivings pragmas src_loc))
145 = pushSrcLocRn src_loc $
146 lookupBndrRn tycon `thenRn` \ tycon' ->
147 bindTyVarsFVRn data_doc tyvars $ \ tyvars' ->
148 rnContext data_doc context `thenRn` \ (context', cxt_fvs) ->
149 checkDupOrQualNames data_doc con_names `thenRn_`
150 mapFvRn rnConDecl condecls `thenRn` \ (condecls', con_fvs) ->
151 rnDerivs derivings `thenRn` \ (derivings', deriv_fvs) ->
152 ASSERT(isNoDataPragmas pragmas)
153 returnRn (TyClD (TyData new_or_data context' tycon' tyvars' condecls' nconstrs
154 derivings' noDataPragmas src_loc),
155 cxt_fvs `plusFV` con_fvs `plusFV` deriv_fvs)
157 data_doc = text "the data type declaration for" <+> quotes (ppr tycon)
158 con_names = map conDeclName condecls
160 rnDecl (TyClD (TySynonym name tyvars ty src_loc))
161 = pushSrcLocRn src_loc $
162 lookupBndrRn name `thenRn` \ name' ->
163 bindTyVarsFVRn syn_doc tyvars $ \ tyvars' ->
164 rnHsType syn_doc (unquantify ty) `thenRn` \ (ty', ty_fvs) ->
165 returnRn (TyClD (TySynonym name' tyvars' ty' src_loc), ty_fvs)
167 syn_doc = text "the declaration for type synonym" <+> quotes (ppr name)
169 -- For H98 we do *not* universally quantify on the RHS of a synonym
170 -- Silently discard context... but the tyvars in the rest won't be in scope
171 unquantify (HsForAllTy Nothing ctxt ty) | not opt_GlasgowExts = ty
174 rnDecl (TyClD (ClassDecl context cname tyvars fds sigs mbinds pragmas
175 tname dname dwname snames src_loc))
176 = pushSrcLocRn src_loc $
178 lookupBndrRn cname `thenRn` \ cname' ->
180 -- Deal with the implicit tycon and datacon name
181 -- They aren't in scope (because they aren't visible to the user)
182 -- and what we want to do is simply look them up in the cache;
183 -- we jolly well ought to get a 'hit' there!
184 -- So the 'Imported' part of this call is not relevant.
185 -- Unclean; but since these two are the only place this happens
186 -- I can't work up the energy to do it more beautifully
187 mkImportedGlobalFromRdrName tname `thenRn` \ tname' ->
188 mkImportedGlobalFromRdrName dname `thenRn` \ dname' ->
189 mkImportedGlobalFromRdrName dwname `thenRn` \ dwname' ->
190 mapRn mkImportedGlobalFromRdrName snames `thenRn` \ snames' ->
192 -- Tyvars scope over bindings and context
193 bindTyVarsFV2Rn cls_doc tyvars ( \ clas_tyvar_names tyvars' ->
195 -- Check the superclasses
196 rnContext cls_doc context `thenRn` \ (context', cxt_fvs) ->
198 -- Check the functional dependencies
199 rnFds cls_doc fds `thenRn` \ (fds', fds_fvs) ->
201 -- Check the signatures
203 -- First process the class op sigs, then the fixity sigs.
204 (op_sigs, non_op_sigs) = partition isClassOpSig sigs
206 checkDupOrQualNames sig_doc sig_rdr_names_w_locs `thenRn_`
207 mapFvRn (rn_op cname' clas_tyvar_names fds') op_sigs `thenRn` \ (sigs', sig_fvs) ->
209 binders = mkNameSet [ nm | (ClassOpSig nm _ _ _ _) <- sigs' ]
211 renameSigs (okClsDclSig binders) non_op_sigs `thenRn` \ (non_ops', fix_fvs) ->
214 checkDupOrQualNames meth_doc meth_rdr_names_w_locs `thenRn_`
216 `thenRn` \ (mbinds', meth_fvs) ->
218 -- Typechecker is responsible for checking that we only
219 -- give default-method bindings for things in this class.
220 -- The renamer *could* check this for class decls, but can't
221 -- for instance decls.
223 ASSERT(isNoClassPragmas pragmas)
224 returnRn (TyClD (ClassDecl context' cname' tyvars' fds' (non_ops' ++ sigs') mbinds'
225 NoClassPragmas tname' dname' dwname' snames' src_loc),
234 cls_doc = text "the declaration for class" <+> ppr cname
235 sig_doc = text "the signatures for class" <+> ppr cname
236 meth_doc = text "the default-methods for class" <+> ppr cname
238 sig_rdr_names_w_locs = [(op,locn) | ClassOpSig op _ _ _ locn <- sigs]
239 meth_rdr_names_w_locs = bagToList (collectMonoBinders mbinds)
240 meth_rdr_names = map fst meth_rdr_names_w_locs
242 rn_op clas clas_tyvars clas_fds sig@(ClassOpSig op dm_rdr_name explicit_dm ty locn)
243 = pushSrcLocRn locn $
244 lookupBndrRn op `thenRn` \ op_name ->
246 -- Check the signature
247 rnHsSigType (quotes (ppr op)) ty `thenRn` \ (new_ty, op_ty_fvs) ->
249 check_in_op_ty clas_tyvar =
250 checkRn (clas_tyvar `elemNameSet` oclose clas_fds op_ty_fvs)
251 (classTyVarNotInOpTyErr clas_tyvar sig)
253 mapRn_ check_in_op_ty clas_tyvars `thenRn_`
255 -- Make the default-method name
256 getModeRn `thenRn` \ mode ->
258 SourceMode -> -- Source class decl
259 newImplicitBinder (mkDefaultMethodOcc (rdrNameOcc op)) locn `thenRn` \ dm_name ->
260 returnRn (dm_name, op `elem` meth_rdr_names, emptyFVs)
263 -> -- Imported class that has a default method decl
264 -- See comments with tname, snames, above
265 lookupImplicitOccRn dm_rdr_name `thenRn` \ dm_name ->
266 returnRn (dm_name, explicit_dm, if explicit_dm then unitFV dm_name else emptyFVs)
267 -- An imported class decl for a class decl that had an explicit default
268 -- method, mentions, rather than defines,
269 -- the default method, so we must arrange to pull it in
270 ) `thenRn` \ (dm_name, final_explicit_dm, dm_fvs) ->
272 returnRn (ClassOpSig op_name dm_name final_explicit_dm new_ty locn, op_ty_fvs `plusFV` dm_fvs)
276 %*********************************************************
278 \subsection{Instance declarations}
280 %*********************************************************
283 rnDecl (InstD (InstDecl inst_ty mbinds uprags dfun_rdr_name src_loc))
284 = pushSrcLocRn src_loc $
285 rnHsSigType (text "an instance decl") inst_ty `thenRn` \ (inst_ty', inst_fvs) ->
287 inst_tyvars = case inst_ty' of
288 HsForAllTy (Just inst_tyvars) _ _ -> inst_tyvars
290 -- (Slightly strangely) the forall-d tyvars scope over
291 -- the method bindings too
294 -- Rename the bindings
295 -- NB meth_names can be qualified!
296 checkDupNames meth_doc meth_names `thenRn_`
297 extendTyVarEnvFVRn inst_tyvars (
299 ) `thenRn` \ (mbinds', meth_fvs) ->
301 binders = mkNameSet (map fst (bagToList (collectMonoBinders mbinds')))
303 -- Rename the prags and signatures.
304 -- Note that the type variables are not in scope here,
305 -- so that instance Eq a => Eq (T a) where
306 -- {-# SPECIALISE instance Eq a => Eq (T [a]) #-}
308 renameSigs (okInstDclSig binders) uprags `thenRn` \ (new_uprags, prag_fvs) ->
310 getModeRn `thenRn` \ mode ->
312 InterfaceMode -> lookupImplicitOccRn dfun_rdr_name `thenRn` \ dfun_name ->
313 returnRn (dfun_name, unitFV dfun_name)
314 SourceMode -> newDFunName (getDFunKey inst_ty') src_loc
315 `thenRn` \ dfun_name ->
316 returnRn (dfun_name, emptyFVs)
318 `thenRn` \ (dfun_name, dfun_fv) ->
320 -- The typechecker checks that all the bindings are for the right class.
321 returnRn (InstD (InstDecl inst_ty' mbinds' new_uprags dfun_name src_loc),
322 inst_fvs `plusFV` meth_fvs `plusFV` prag_fvs `plusFV` dfun_fv)
324 meth_doc = text "the bindings in an instance declaration"
325 meth_names = bagToList (collectMonoBinders mbinds)
328 %*********************************************************
330 \subsection{Default declarations}
332 %*********************************************************
335 rnDecl (DefD (DefaultDecl tys src_loc))
336 = pushSrcLocRn src_loc $
337 rnHsTypes doc_str tys `thenRn` \ (tys', fvs) ->
338 returnRn (DefD (DefaultDecl tys' src_loc), fvs)
340 doc_str = text "a `default' declaration"
343 %*********************************************************
345 \subsection{Foreign declarations}
347 %*********************************************************
350 rnDecl (ForD (ForeignDecl name imp_exp ty ext_nm cconv src_loc))
351 = pushSrcLocRn src_loc $
352 lookupOccRn name `thenRn` \ name' ->
355 | isDyn = lookupImplicitOccsRn [makeStablePtr_RDR, deRefStablePtr_RDR, bindIO_RDR]
356 | otherwise = returnRn (unitFV name')
357 extra_fvs other = returnRn emptyFVs
359 checkRn (ok_ext_nm ext_nm) (badExtName ext_nm) `thenRn_`
360 extra_fvs imp_exp `thenRn` \ fvs1 ->
361 rnHsSigType fo_decl_msg ty `thenRn` \ (ty', fvs2) ->
362 returnRn (ForD (ForeignDecl name' imp_exp ty' ext_nm cconv src_loc),
365 fo_decl_msg = ptext SLIT("a foreign declaration")
366 isDyn = isDynamicExtName ext_nm
368 ok_ext_nm Dynamic = True
369 ok_ext_nm (ExtName nm (Just mb)) = isCLabelString nm && isCLabelString mb
370 ok_ext_nm (ExtName nm Nothing) = isCLabelString nm
373 %*********************************************************
377 %*********************************************************
380 rnDecl (RuleD (IfaceRule rule_name vars fn args rhs src_loc))
381 = pushSrcLocRn src_loc $
382 lookupOccRn fn `thenRn` \ fn' ->
383 rnCoreBndrs vars $ \ vars' ->
384 mapFvRn rnCoreExpr args `thenRn` \ (args', fvs1) ->
385 rnCoreExpr rhs `thenRn` \ (rhs', fvs2) ->
386 returnRn (RuleD (IfaceRule rule_name vars' fn' args' rhs' src_loc),
387 (fvs1 `plusFV` fvs2) `addOneFV` fn')
389 rnDecl (RuleD (IfaceRuleOut fn rule))
390 -- This one is used for BuiltInRules
391 -- The rule itself is already done, but the thing
392 -- to attach it to is not.
393 = lookupOccRn fn `thenRn` \ fn' ->
394 returnRn (RuleD (IfaceRuleOut fn' rule), unitFV fn')
396 rnDecl (RuleD (HsRule rule_name tvs vars lhs rhs src_loc))
398 pushSrcLocRn src_loc $
400 bindTyVarsFV2Rn doc (map UserTyVar sig_tvs) $ \ sig_tvs' _ ->
401 bindLocalsFVRn doc (map get_var vars) $ \ ids ->
402 mapFvRn rn_var (vars `zip` ids) `thenRn` \ (vars', fv_vars) ->
404 rnExpr lhs `thenRn` \ (lhs', fv_lhs) ->
405 rnExpr rhs `thenRn` \ (rhs', fv_rhs) ->
406 checkRn (validRuleLhs ids lhs')
407 (badRuleLhsErr rule_name lhs') `thenRn_`
409 bad_vars = [var | var <- ids, not (var `elemNameSet` fv_lhs)]
411 mapRn (addErrRn . badRuleVar rule_name) bad_vars `thenRn_`
412 returnRn (RuleD (HsRule rule_name sig_tvs' vars' lhs' rhs' src_loc),
413 fv_vars `plusFV` fv_lhs `plusFV` fv_rhs)
415 doc = text "the transformation rule" <+> ptext rule_name
416 sig_tvs = extractRuleBndrsTyVars vars
418 get_var (RuleBndr v) = v
419 get_var (RuleBndrSig v _) = v
421 rn_var (RuleBndr v, id) = returnRn (RuleBndr id, emptyFVs)
422 rn_var (RuleBndrSig v t, id) = rnHsType doc t `thenRn` \ (t', fvs) ->
423 returnRn (RuleBndrSig id t', fvs)
427 %*********************************************************
429 \subsection{Support code for type/data declarations}
431 %*********************************************************
434 rnDerivs :: Maybe [RdrName] -> RnMS (Maybe [Name], FreeVars)
436 rnDerivs Nothing -- derivs not specified
437 = returnRn (Nothing, emptyFVs)
440 = mapRn do_one clss `thenRn` \ clss' ->
441 returnRn (Just clss', mkNameSet clss')
443 do_one cls = lookupOccRn cls `thenRn` \ clas_name ->
444 checkRn (getUnique clas_name `elem` derivableClassKeys)
445 (derivingNonStdClassErr clas_name) `thenRn_`
450 conDeclName :: RdrNameConDecl -> (RdrName, SrcLoc)
451 conDeclName (ConDecl n _ _ _ _ l) = (n,l)
453 rnConDecl :: RdrNameConDecl -> RnMS (RenamedConDecl, FreeVars)
454 rnConDecl (ConDecl name wkr tvs cxt details locn)
455 = pushSrcLocRn locn $
456 checkConName name `thenRn_`
457 lookupBndrRn name `thenRn` \ new_name ->
459 mkImportedGlobalFromRdrName wkr `thenRn` \ new_wkr ->
460 -- See comments with ClassDecl
462 bindTyVarsFVRn doc tvs $ \ new_tyvars ->
463 rnContext doc cxt `thenRn` \ (new_context, cxt_fvs) ->
464 rnConDetails doc locn details `thenRn` \ (new_details, det_fvs) ->
465 returnRn (ConDecl new_name new_wkr new_tyvars new_context new_details locn,
466 cxt_fvs `plusFV` det_fvs)
468 doc = text "the definition of data constructor" <+> quotes (ppr name)
470 rnConDetails doc locn (VanillaCon tys)
471 = mapFvRn (rnBangTy doc) tys `thenRn` \ (new_tys, fvs) ->
472 returnRn (VanillaCon new_tys, fvs)
474 rnConDetails doc locn (InfixCon ty1 ty2)
475 = rnBangTy doc ty1 `thenRn` \ (new_ty1, fvs1) ->
476 rnBangTy doc ty2 `thenRn` \ (new_ty2, fvs2) ->
477 returnRn (InfixCon new_ty1 new_ty2, fvs1 `plusFV` fvs2)
479 rnConDetails doc locn (NewCon ty mb_field)
480 = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
481 rn_field mb_field `thenRn` \ new_mb_field ->
482 returnRn (NewCon new_ty new_mb_field, fvs)
484 rn_field Nothing = returnRn Nothing
486 lookupBndrRn f `thenRn` \ new_f ->
487 returnRn (Just new_f)
489 rnConDetails doc locn (RecCon fields)
490 = checkDupOrQualNames doc field_names `thenRn_`
491 mapFvRn (rnField doc) fields `thenRn` \ (new_fields, fvs) ->
492 returnRn (RecCon new_fields, fvs)
494 field_names = [(fld, locn) | (flds, _) <- fields, fld <- flds]
496 rnField doc (names, ty)
497 = mapRn lookupBndrRn names `thenRn` \ new_names ->
498 rnBangTy doc ty `thenRn` \ (new_ty, fvs) ->
499 returnRn ((new_names, new_ty), fvs)
501 rnBangTy doc (Banged ty)
502 = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
503 returnRn (Banged new_ty, fvs)
505 rnBangTy doc (Unbanged ty)
506 = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
507 returnRn (Unbanged new_ty, fvs)
509 rnBangTy doc (Unpacked ty)
510 = rnHsType doc ty `thenRn` \ (new_ty, fvs) ->
511 returnRn (Unpacked new_ty, fvs)
513 -- This data decl will parse OK
515 -- treating "a" as the constructor.
516 -- It is really hard to make the parser spot this malformation.
517 -- So the renamer has to check that the constructor is legal
519 -- We can get an operator as the constructor, even in the prefix form:
520 -- data T = :% Int Int
521 -- from interface files, which always print in prefix form
524 = checkRn (isRdrDataCon name)
529 %*********************************************************
531 \subsection{Support code to rename types}
533 %*********************************************************
536 rnHsSigType :: SDoc -> RdrNameHsType -> RnMS (RenamedHsType, FreeVars)
537 -- rnHsSigType is used for source-language type signatures,
538 -- which use *implicit* universal quantification.
539 rnHsSigType doc_str ty
540 = rnHsType (text "the type signature for" <+> doc_str) ty
542 ---------------------------------------
543 rnHsType :: SDoc -> RdrNameHsType -> RnMS (RenamedHsType, FreeVars)
545 rnHsType doc (HsForAllTy Nothing ctxt ty)
546 -- Implicit quantifiction in source code (no kinds on tyvars)
547 -- Given the signature C => T we universally quantify
548 -- over FV(T) \ {in-scope-tyvars}
549 = getLocalNameEnv `thenRn` \ name_env ->
551 mentioned_in_tau = extractHsTyRdrTyVars ty
552 forall_tyvars = filter (not . (`elemFM` name_env)) mentioned_in_tau
554 checkConstraints doc forall_tyvars mentioned_in_tau ctxt ty `thenRn` \ ctxt' ->
555 rnForAll doc (map UserTyVar forall_tyvars) ctxt' ty
557 rnHsType doc (HsForAllTy (Just forall_tyvars) ctxt tau)
558 -- Explicit quantification.
559 -- Check that the forall'd tyvars are a subset of the
560 -- free tyvars in the tau-type part
561 -- That's only a warning... unless the tyvar is constrained by a
562 -- context in which case it's an error
564 mentioned_in_tau = extractHsTyRdrTyVars tau
565 mentioned_in_ctxt = nub [tv | p <- ctxt,
567 tv <- extractHsTyRdrTyVars ty]
568 tys_of_pred (HsPClass clas tys) = tys
569 tys_of_pred (HsPIParam n ty) = [ty]
571 dubious_guys = filter (`notElem` mentioned_in_tau) forall_tyvar_names
572 -- dubious = explicitly quantified but not mentioned in tau type
574 (bad_guys, warn_guys) = partition (`elem` mentioned_in_ctxt) dubious_guys
575 -- bad = explicitly quantified and constrained, but not mentioned in tau
576 -- warn = explicitly quantified but not mentioned in ctxt or tau
578 forall_tyvar_names = map getTyVarName forall_tyvars
580 -- mapRn_ (forAllErr doc tau) bad_guys `thenRn_`
581 mapRn_ (forAllWarn doc tau) warn_guys `thenRn_`
582 checkConstraints doc forall_tyvar_names mentioned_in_tau ctxt tau `thenRn` \ ctxt' ->
583 rnForAll doc forall_tyvars ctxt' tau
585 rnHsType doc (HsTyVar tyvar)
586 = lookupOccRn tyvar `thenRn` \ tyvar' ->
587 returnRn (HsTyVar tyvar', unitFV tyvar')
589 rnHsType doc (HsFunTy ty1 ty2)
590 = rnHsType doc ty1 `thenRn` \ (ty1', fvs1) ->
591 -- Might find a for-all as the arg of a function type
592 rnHsType doc ty2 `thenRn` \ (ty2', fvs2) ->
593 -- Or as the result. This happens when reading Prelude.hi
594 -- when we find return :: forall m. Monad m -> forall a. a -> m a
595 returnRn (HsFunTy ty1' ty2', fvs1 `plusFV` fvs2)
597 rnHsType doc (HsListTy ty)
598 = rnHsType doc ty `thenRn` \ (ty', fvs) ->
599 returnRn (HsListTy ty', fvs `addOneFV` listTyCon_name)
601 -- Unboxed tuples are allowed to have poly-typed arguments. These
602 -- sometimes crop up as a result of CPR worker-wrappering dictionaries.
603 rnHsType doc (HsTupleTy (HsTupCon _ boxity) tys)
604 -- Don't do lookupOccRn, because this is built-in syntax
605 -- so it doesn't need to be in scope
606 = mapFvRn (rnHsType doc) tys `thenRn` \ (tys', fvs) ->
607 returnRn (HsTupleTy (HsTupCon n' boxity) tys', fvs `addOneFV` n')
609 n' = tupleTyCon_name boxity (length tys)
612 rnHsType doc (HsAppTy ty1 ty2)
613 = rnHsType doc ty1 `thenRn` \ (ty1', fvs1) ->
614 rnHsType doc ty2 `thenRn` \ (ty2', fvs2) ->
615 returnRn (HsAppTy ty1' ty2', fvs1 `plusFV` fvs2)
617 rnHsType doc (HsPredTy pred)
618 = rnPred doc pred `thenRn` \ (pred', fvs) ->
619 returnRn (HsPredTy pred', fvs)
621 rnHsType doc (HsUsgForAllTy uv_rdr ty)
622 = bindUVarRn doc uv_rdr $ \ uv_name ->
623 rnHsType doc ty `thenRn` \ (ty', fvs) ->
624 returnRn (HsUsgForAllTy uv_name ty',
627 rnHsType doc (HsUsgTy usg ty)
628 = newUsg usg `thenRn` \ (usg', usg_fvs) ->
629 rnHsType doc ty `thenRn` \ (ty', ty_fvs) ->
630 -- A for-all can occur inside a usage annotation
631 returnRn (HsUsgTy usg' ty',
632 usg_fvs `plusFV` ty_fvs)
634 newUsg usg = case usg of
635 HsUsOnce -> returnRn (HsUsOnce, emptyFVs)
636 HsUsMany -> returnRn (HsUsMany, emptyFVs)
637 HsUsVar uv_rdr -> lookupOccRn uv_rdr `thenRn` \ uv_name ->
638 returnRn (HsUsVar uv_name, emptyFVs)
640 rnHsTypes doc tys = mapFvRn (rnHsType doc) tys
644 -- We use lookupOcc here because this is interface file only stuff
645 -- and we need the workers...
646 rnHsTupCon (HsTupCon n boxity)
647 = lookupOccRn n `thenRn` \ n' ->
648 returnRn (HsTupCon n' boxity, unitFV n')
650 rnHsTupConWkr (HsTupCon n boxity)
651 -- Tuple construtors are for the *worker* of the tuple
652 -- Going direct saves needless messing about
653 = lookupOccRn (mkRdrNameWkr n) `thenRn` \ n' ->
654 returnRn (HsTupCon n' boxity, unitFV n')
658 -- Check that each constraint mentions at least one of the forall'd type variables
659 -- Since the forall'd type variables are a subset of the free tyvars
660 -- of the tau-type part, this guarantees that every constraint mentions
661 -- at least one of the free tyvars in ty
662 checkConstraints doc forall_tyvars tau_vars ctxt ty
663 = mapRn (checkPred doc forall_tyvars ty) ctxt `thenRn` \ maybe_ctxt' ->
664 returnRn (catMaybes maybe_ctxt')
665 -- Remove problem ones, to avoid duplicate error message.
667 checkPred doc forall_tyvars ty p@(HsPClass clas tys)
668 | not_univ = failWithRn Nothing (univErr doc p ty)
669 | otherwise = returnRn (Just p)
671 ct_vars = extractHsTysRdrTyVars tys
672 not_univ = -- At least one of the tyvars in each constraint must
673 -- be universally quantified. This restriction isn't in Hugs
674 not (any (`elem` forall_tyvars) ct_vars)
675 checkPred doc forall_tyvars ty p@(HsPIParam _ _)
678 rnForAll doc forall_tyvars ctxt ty
679 = bindTyVarsFVRn doc forall_tyvars $ \ new_tyvars ->
680 rnContext doc ctxt `thenRn` \ (new_ctxt, cxt_fvs) ->
681 rnHsType doc ty `thenRn` \ (new_ty, ty_fvs) ->
682 returnRn (mkHsForAllTy (Just new_tyvars) new_ctxt new_ty,
683 cxt_fvs `plusFV` ty_fvs)
687 rnContext :: SDoc -> RdrNameContext -> RnMS (RenamedContext, FreeVars)
689 = mapAndUnzipRn rn_pred ctxt `thenRn` \ (theta, fvs_s) ->
691 (_, dups) = removeDupsEq theta
692 -- We only have equality, not ordering
694 -- Check for duplicate assertions
695 -- If this isn't an error, then it ought to be:
696 mapRn (addWarnRn . dupClassAssertWarn theta) dups `thenRn_`
697 returnRn (theta, plusFVs fvs_s)
699 --Someone discovered that @CCallable@ and @CReturnable@
700 -- could be used in contexts such as:
701 -- foo :: CCallable a => a -> PrimIO Int
702 -- Doing this utterly wrecks the whole point of introducing these
703 -- classes so we specifically check that this isn't being done.
704 rn_pred pred = rnPred doc pred `thenRn` \ (pred', fvs)->
705 checkRn (not (bad_pred pred'))
706 (naughtyCCallContextErr pred') `thenRn_`
707 returnRn (pred', fvs)
709 bad_pred (HsPClass clas _) = getUnique clas `elem` cCallishClassKeys
710 bad_pred other = False
713 rnPred doc (HsPClass clas tys)
714 = lookupOccRn clas `thenRn` \ clas_name ->
715 rnHsTypes doc tys `thenRn` \ (tys', fvs) ->
716 returnRn (HsPClass clas_name tys', fvs `addOneFV` clas_name)
718 rnPred doc (HsPIParam n ty)
719 = getIPName n `thenRn` \ name ->
720 rnHsType doc ty `thenRn` \ (ty', fvs) ->
721 returnRn (HsPIParam name ty', fvs)
725 rnFds :: SDoc -> [FunDep RdrName] -> RnMS ([FunDep Name], FreeVars)
728 = mapAndUnzipRn rn_fds fds `thenRn` \ (theta, fvs_s) ->
729 returnRn (theta, plusFVs fvs_s)
732 = rnHsTyVars doc tys1 `thenRn` \ (tys1', fvs1) ->
733 rnHsTyVars doc tys2 `thenRn` \ (tys2', fvs2) ->
734 returnRn ((tys1', tys2'), fvs1 `plusFV` fvs2)
736 rnHsTyVars doc tvs = mapFvRn (rnHsTyvar doc) tvs
738 = lookupOccRn tyvar `thenRn` \ tyvar' ->
739 returnRn (tyvar', unitFV tyvar')
742 %*********************************************************
746 %*********************************************************
749 rnIdInfo (HsStrictness str) = returnRn (HsStrictness str, emptyFVs)
751 rnIdInfo (HsWorker worker)
752 = lookupOccRn worker `thenRn` \ worker' ->
753 returnRn (HsWorker worker', unitFV worker')
755 rnIdInfo (HsUnfold inline expr) = rnCoreExpr expr `thenRn` \ (expr', fvs) ->
756 returnRn (HsUnfold inline expr', fvs)
757 rnIdInfo (HsArity arity) = returnRn (HsArity arity, emptyFVs)
758 rnIdInfo (HsUpdate update) = returnRn (HsUpdate update, emptyFVs)
759 rnIdInfo HsNoCafRefs = returnRn (HsNoCafRefs, emptyFVs)
760 rnIdInfo HsCprInfo = returnRn (HsCprInfo, emptyFVs)
764 @UfCore@ expressions.
767 rnCoreExpr (UfType ty)
768 = rnHsType (text "unfolding type") ty `thenRn` \ (ty', fvs) ->
769 returnRn (UfType ty', fvs)
772 = lookupOccRn v `thenRn` \ v' ->
773 returnRn (UfVar v', unitFV v')
776 = returnRn (UfLit l, emptyFVs)
778 rnCoreExpr (UfLitLit l ty)
779 = rnHsType (text "litlit") ty `thenRn` \ (ty', fvs) ->
780 returnRn (UfLitLit l ty', fvs)
782 rnCoreExpr (UfCCall cc ty)
783 = rnHsType (text "ccall") ty `thenRn` \ (ty', fvs) ->
784 returnRn (UfCCall cc ty', fvs)
786 rnCoreExpr (UfTuple con args)
787 = rnHsTupConWkr con `thenRn` \ (con', fvs1) ->
788 mapFvRn rnCoreExpr args `thenRn` \ (args', fvs2) ->
789 returnRn (UfTuple con' args', fvs1 `plusFV` fvs2)
791 rnCoreExpr (UfApp fun arg)
792 = rnCoreExpr fun `thenRn` \ (fun', fv1) ->
793 rnCoreExpr arg `thenRn` \ (arg', fv2) ->
794 returnRn (UfApp fun' arg', fv1 `plusFV` fv2)
796 rnCoreExpr (UfCase scrut bndr alts)
797 = rnCoreExpr scrut `thenRn` \ (scrut', fvs1) ->
798 bindCoreLocalFVRn bndr ( \ bndr' ->
799 mapFvRn rnCoreAlt alts `thenRn` \ (alts', fvs2) ->
800 returnRn (UfCase scrut' bndr' alts', fvs2)
801 ) `thenRn` \ (case', fvs3) ->
802 returnRn (case', fvs1 `plusFV` fvs3)
804 rnCoreExpr (UfNote note expr)
805 = rnNote note `thenRn` \ (note', fvs1) ->
806 rnCoreExpr expr `thenRn` \ (expr', fvs2) ->
807 returnRn (UfNote note' expr', fvs1 `plusFV` fvs2)
809 rnCoreExpr (UfLam bndr body)
810 = rnCoreBndr bndr $ \ bndr' ->
811 rnCoreExpr body `thenRn` \ (body', fvs) ->
812 returnRn (UfLam bndr' body', fvs)
814 rnCoreExpr (UfLet (UfNonRec bndr rhs) body)
815 = rnCoreExpr rhs `thenRn` \ (rhs', fvs1) ->
816 rnCoreBndr bndr ( \ bndr' ->
817 rnCoreExpr body `thenRn` \ (body', fvs2) ->
818 returnRn (UfLet (UfNonRec bndr' rhs') body', fvs2)
819 ) `thenRn` \ (result, fvs3) ->
820 returnRn (result, fvs1 `plusFV` fvs3)
822 rnCoreExpr (UfLet (UfRec pairs) body)
823 = rnCoreBndrs bndrs $ \ bndrs' ->
824 mapFvRn rnCoreExpr rhss `thenRn` \ (rhss', fvs1) ->
825 rnCoreExpr body `thenRn` \ (body', fvs2) ->
826 returnRn (UfLet (UfRec (bndrs' `zip` rhss')) body', fvs1 `plusFV` fvs2)
828 (bndrs, rhss) = unzip pairs
832 rnCoreBndr (UfValBinder name ty) thing_inside
833 = rnHsType doc ty `thenRn` \ (ty', fvs1) ->
834 bindCoreLocalFVRn name ( \ name' ->
835 thing_inside (UfValBinder name' ty')
836 ) `thenRn` \ (result, fvs2) ->
837 returnRn (result, fvs1 `plusFV` fvs2)
839 doc = text "unfolding id"
841 rnCoreBndr (UfTyBinder name kind) thing_inside
842 = bindCoreLocalFVRn name $ \ name' ->
843 thing_inside (UfTyBinder name' kind)
845 rnCoreBndrs [] thing_inside = thing_inside []
846 rnCoreBndrs (b:bs) thing_inside = rnCoreBndr b $ \ name' ->
847 rnCoreBndrs bs $ \ names' ->
848 thing_inside (name':names')
852 rnCoreAlt (con, bndrs, rhs)
853 = rnUfCon con bndrs `thenRn` \ (con', fvs1) ->
854 bindCoreLocalsFVRn bndrs ( \ bndrs' ->
855 rnCoreExpr rhs `thenRn` \ (rhs', fvs2) ->
856 returnRn ((con', bndrs', rhs'), fvs2)
857 ) `thenRn` \ (result, fvs3) ->
858 returnRn (result, fvs1 `plusFV` fvs3)
861 = rnHsType (text "unfolding coerce") ty `thenRn` \ (ty', fvs) ->
862 returnRn (UfCoerce ty', fvs)
864 rnNote (UfSCC cc) = returnRn (UfSCC cc, emptyFVs)
865 rnNote UfInlineCall = returnRn (UfInlineCall, emptyFVs)
866 rnNote UfInlineMe = returnRn (UfInlineMe, emptyFVs)
870 = returnRn (UfDefault, emptyFVs)
872 rnUfCon (UfTupleAlt tup_con) bndrs
873 = rnHsTupCon tup_con `thenRn` \ (HsTupCon con' _, fvs) ->
874 returnRn (UfDataAlt con', fvs)
875 -- Makes the type checker a little easier
877 rnUfCon (UfDataAlt con) _
878 = lookupOccRn con `thenRn` \ con' ->
879 returnRn (UfDataAlt con', unitFV con')
881 rnUfCon (UfLitAlt lit) _
882 = returnRn (UfLitAlt lit, emptyFVs)
884 rnUfCon (UfLitLitAlt lit ty) _
885 = rnHsType (text "litlit") ty `thenRn` \ (ty', fvs) ->
886 returnRn (UfLitLitAlt lit ty', fvs)
889 %*********************************************************
891 \subsection{Rule shapes}
893 %*********************************************************
895 Check the shape of a transformation rule LHS. Currently
896 we only allow LHSs of the form @(f e1 .. en)@, where @f@ is
897 not one of the @forall@'d variables.
900 validRuleLhs foralls lhs
903 check (HsApp e1 e2) = check e1
904 check (HsVar v) | v `notElem` foralls = True
909 %*********************************************************
913 %*********************************************************
916 derivingNonStdClassErr clas
917 = hsep [ptext SLIT("non-standard class"), ppr clas, ptext SLIT("in deriving clause")]
919 classTyVarNotInOpTyErr clas_tyvar sig
920 = hang (hsep [ptext SLIT("Class type variable"),
921 quotes (ppr clas_tyvar),
922 ptext SLIT("does not appear in method signature")])
926 = hsep [ptext SLIT("Illegal data constructor name"), quotes (ppr name)]
928 forAllWarn doc ty tyvar
929 | not opt_WarnUnusedMatches = returnRn ()
931 = getModeRn `thenRn` \ mode ->
934 InterfaceMode -> returnRn () ; -- Don't warn of unused tyvars in interface files
935 -- unless DEBUG is on, in which case it is slightly
936 -- informative. They can arise from mkRhsTyLam,
937 #endif -- leading to (say) f :: forall a b. [b] -> [b]
941 sep [ptext SLIT("The universally quantified type variable") <+> quotes (ppr tyvar),
942 nest 4 (ptext SLIT("does not appear in the type") <+> quotes (ppr ty))]
944 (ptext SLIT("In") <+> doc))
947 forAllErr doc ty tyvar
949 sep [ptext SLIT("The constrained type variable") <+> quotes (ppr tyvar),
950 nest 4 (ptext SLIT("does not appear in the type") <+> quotes (ppr ty))]
952 (ptext SLIT("In") <+> doc))
954 univErr doc constraint ty
955 = sep [ptext SLIT("All of the type variable(s) in the constraint")
956 <+> quotes (ppr constraint)
957 <+> ptext SLIT("are already in scope"),
958 nest 4 (ptext SLIT("At least one must be universally quantified here"))
961 (ptext SLIT("In") <+> doc)
963 ambigErr doc constraint ty
964 = sep [ptext SLIT("Ambiguous constraint") <+> quotes (ppr constraint),
965 nest 4 (ptext SLIT("in the type:") <+> ppr ty),
966 nest 4 (ptext SLIT("Each forall-d type variable mentioned by the constraint must appear after the =>."))]
968 (ptext SLIT("In") <+> doc)
970 badRuleLhsErr name lhs
971 = sep [ptext SLIT("Rule") <+> ptext name <> colon,
972 nest 4 (ptext SLIT("Illegal left-hand side:") <+> ppr lhs)]
974 ptext SLIT("LHS must be of form (f e1 .. en) where f is not forall'd")
977 = sep [ptext SLIT("Rule") <+> ptext name <> colon,
978 ptext SLIT("Forall'd variable") <+> quotes (ppr var) <+>
979 ptext SLIT("does not appear on left hand side")]
981 badExtName :: ExtName -> Message
983 = sep [quotes (ppr ext_nm) <+> ptext SLIT("is not a valid C identifier")]
985 dupClassAssertWarn ctxt (assertion : dups)
986 = sep [hsep [ptext SLIT("Duplicate class assertion"),
987 quotes (ppr assertion),
988 ptext SLIT("in the context:")],
989 nest 4 (ppr ctxt <+> ptext SLIT("..."))]
991 naughtyCCallContextErr (HsPClass clas _)
992 = sep [ptext SLIT("Can't use class") <+> quotes (ppr clas),
993 ptext SLIT("in a context")]