2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[RnSource]{Main pass of renamer}
13 #include "HsVersions.h"
15 import {-# SOURCE #-} RnExpr( rnLExpr )
18 import RdrName ( RdrName, isRdrDataCon, elemLocalRdrEnv,
19 globalRdrEnvElts, GlobalRdrElt(..), isLocalGRE, rdrNameOcc )
20 import RdrHsSyn ( extractGenericPatTyVars, extractHsRhoRdrTyVars )
22 import RnTypes ( rnLHsType, rnLHsTypes, rnHsSigType, rnHsTypeFVs, rnContext )
23 import RnBinds ( rnTopBindsLHS, rnTopBindsRHS, rnMethodBinds, renameSigs, mkSigTvFn,
25 import RnEnv ( lookupLocalDataTcNames,
26 lookupLocatedTopBndrRn, lookupLocatedOccRn,
27 lookupOccRn, newLocalsRn,
28 bindLocatedLocalsFV, bindPatSigTyVarsFV,
29 bindTyVarsRn, extendTyVarEnvFVRn,
30 bindLocalNames, checkDupRdrNames, mapFvRn,
32 import RnNames ( getLocalNonValBinders, extendGlobalRdrEnvRn )
33 import HscTypes ( GenAvailInfo(..) )
34 import RnHsDoc ( rnHsDoc, rnMbLHsDoc )
37 import HscTypes ( Warnings(..), plusWarns )
38 import Class ( FunDep )
39 import Name ( Name, nameOccName )
46 import SrcLoc ( Located(..), unLoc, noLoc )
47 import DynFlags ( DynFlag(..) )
48 import Maybe ( isNothing )
49 import BasicTypes ( Boxity(..) )
51 import ListSetOps (findDupsEq)
58 thenM :: Monad a => a b -> (b -> a c) -> a c
61 thenM_ :: Monad a => a b -> a c -> a c
64 returnM :: Monad m => a -> m a
67 mappM :: (Monad m) => (a -> m b) -> [a] -> m [b]
70 mappM_ :: (Monad m) => (a -> m b) -> [a] -> m ()
73 checkM :: Monad m => Bool -> m () -> m ()
77 @rnSourceDecl@ `renames' declarations.
78 It simultaneously performs dependency analysis and precedence parsing.
79 It also does the following error checks:
82 Checks that tyvars are used properly. This includes checking
83 for undefined tyvars, and tyvars in contexts that are ambiguous.
84 (Some of this checking has now been moved to module @TcMonoType@,
85 since we don't have functional dependency information at this point.)
87 Checks that all variable occurences are defined.
89 Checks the @(..)@ etc constraints in the export list.
94 -- Brings the binders of the group into scope in the appropriate places;
95 -- does NOT assume that anything is in scope already
97 -- The Bool determines whether (True) names in the group shadow existing
98 -- Unquals in the global environment (used in Template Haskell) or
99 -- (False) whether duplicates are reported as an error
100 rnSrcDecls :: Bool -> HsGroup RdrName -> RnM (TcGblEnv, HsGroup Name)
102 rnSrcDecls shadowP group@(HsGroup {hs_valds = val_decls,
103 hs_tyclds = tycl_decls,
104 hs_instds = inst_decls,
105 hs_derivds = deriv_decls,
106 hs_fixds = fix_decls,
107 hs_warnds = warn_decls,
108 hs_fords = foreign_decls,
109 hs_defds = default_decls,
110 hs_ruleds = rule_decls,
113 -- (A) Process the fixity declarations, creating a mapping from
114 -- FastStrings to FixItems.
115 -- Also checks for duplcates.
116 local_fix_env <- makeMiniFixityEnv fix_decls;
118 -- (B) Bring top level binders (and their fixities) into scope,
119 -- *except* for the value bindings, which get brought in below.
120 avails <- getLocalNonValBinders group ;
121 tc_envs <- extendGlobalRdrEnvRn shadowP avails local_fix_env ;
122 setEnvs tc_envs $ do {
124 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
126 -- (C) Extract the mapping from data constructors to field names and
127 -- extend the record field env.
128 -- This depends on the data constructors and field names being in
129 -- scope from (B) above
130 inNewEnv (extendRecordFieldEnv tycl_decls) $ \ _ -> do {
132 -- (D) Rename the left-hand sides of the value bindings.
133 -- This depends on everything from (B) being in scope,
134 -- and on (C) for resolving record wild cards.
135 -- It uses the fixity env from (A) to bind fixities for view patterns.
136 new_lhs <- rnTopBindsLHS local_fix_env val_decls ;
137 -- bind the LHSes (and their fixities) in the global rdr environment
138 let { lhs_binders = map unLoc $ collectHsValBinders new_lhs;
139 lhs_avails = map Avail lhs_binders
141 (tcg_env, tcl_env) <- extendGlobalRdrEnvRn shadowP lhs_avails local_fix_env ;
142 setEnvs (tcg_env, tcl_env) $ do {
144 -- Now everything is in scope, as the remaining renaming assumes.
146 -- (E) Rename type and class decls
147 -- (note that value LHSes need to be in scope for default methods)
149 -- You might think that we could build proper def/use information
150 -- for type and class declarations, but they can be involved
151 -- in mutual recursion across modules, and we only do the SCC
152 -- analysis for them in the type checker.
153 -- So we content ourselves with gathering uses only; that
154 -- means we'll only report a declaration as unused if it isn't
155 -- mentioned at all. Ah well.
156 traceRn (text "Start rnTyClDecls") ;
157 (rn_tycl_decls, src_fvs1) <- rnList rnTyClDecl tycl_decls ;
159 -- (F) Rename Value declarations right-hand sides
160 traceRn (text "Start rnmono") ;
161 (rn_val_decls, bind_dus) <- rnTopBindsRHS lhs_binders new_lhs ;
162 traceRn (text "finish rnmono" <+> ppr rn_val_decls) ;
164 -- (G) Rename Fixity and deprecations
166 -- rename fixity declarations and error if we try to
167 -- fix something from another module (duplicates were checked in (A))
168 rn_fix_decls <- rnSrcFixityDecls fix_decls ;
169 -- rename deprec decls;
170 -- check for duplicates and ensure that deprecated things are defined locally
171 -- at the moment, we don't keep these around past renaming
172 rn_warns <- rnSrcWarnDecls warn_decls ;
174 -- (H) Rename Everything else
176 (rn_inst_decls, src_fvs2) <- rnList rnSrcInstDecl inst_decls ;
177 (rn_rule_decls, src_fvs3) <- rnList rnHsRuleDecl rule_decls ;
178 (rn_foreign_decls, src_fvs4) <- rnList rnHsForeignDecl foreign_decls ;
179 (rn_default_decls, src_fvs5) <- rnList rnDefaultDecl default_decls ;
180 (rn_deriv_decls, src_fvs6) <- rnList rnSrcDerivDecl deriv_decls ;
181 -- Haddock docs; no free vars
182 rn_docs <- mapM (wrapLocM rnDocDecl) docs ;
184 -- (I) Compute the results and return
185 let {rn_group = HsGroup { hs_valds = rn_val_decls,
186 hs_tyclds = rn_tycl_decls,
187 hs_instds = rn_inst_decls,
188 hs_derivds = rn_deriv_decls,
189 hs_fixds = rn_fix_decls,
190 hs_warnds = [], -- warns are returned in the tcg_env
191 -- (see below) not in the HsGroup
192 hs_fords = rn_foreign_decls,
193 hs_defds = rn_default_decls,
194 hs_ruleds = rn_rule_decls,
195 hs_docs = rn_docs } ;
197 other_fvs = plusFVs [src_fvs1, src_fvs2, src_fvs6, src_fvs3,
198 src_fvs4, src_fvs5] ;
199 src_dus = bind_dus `plusDU` usesOnly other_fvs;
200 -- Note: src_dus will contain *uses* for locally-defined types
201 -- and classes, but no *defs* for them. (Because rnTyClDecl
202 -- returns only the uses.) This is a little
203 -- surprising but it doesn't actually matter at all.
205 final_tcg_env = let tcg_env' = (tcg_env `addTcgDUs` src_dus)
206 in -- we return the deprecs in the env, not in the HsGroup above
207 tcg_env' { tcg_warns = tcg_warns tcg_env' `plusWarns` rn_warns };
210 traceRn (text "finish rnSrc" <+> ppr rn_group) ;
211 traceRn (text "finish Dus" <+> ppr src_dus ) ;
212 return (final_tcg_env , rn_group)
215 -- some utils because we do this a bunch above
216 -- compute and install the new env
217 inNewEnv :: TcM TcGblEnv -> (TcGblEnv -> TcM a) -> TcM a
218 inNewEnv env cont = do e <- env
221 rnTyClDecls :: [LTyClDecl RdrName] -> RnM [LTyClDecl Name]
222 -- Used for external core
223 rnTyClDecls tycl_decls = do (decls', _fvs) <- rnList rnTyClDecl tycl_decls
226 addTcgDUs :: TcGblEnv -> DefUses -> TcGblEnv
227 addTcgDUs tcg_env dus = tcg_env { tcg_dus = tcg_dus tcg_env `plusDU` dus }
229 rnList :: (a -> RnM (b, FreeVars)) -> [Located a] -> RnM ([Located b], FreeVars)
230 rnList f xs = mapFvRn (wrapLocFstM f) xs
234 %*********************************************************
238 %*********************************************************
241 rnDocDecl :: DocDecl RdrName -> RnM (DocDecl Name)
242 rnDocDecl (DocCommentNext doc) = do
243 rn_doc <- rnHsDoc doc
244 return (DocCommentNext rn_doc)
245 rnDocDecl (DocCommentPrev doc) = do
246 rn_doc <- rnHsDoc doc
247 return (DocCommentPrev rn_doc)
248 rnDocDecl (DocCommentNamed str doc) = do
249 rn_doc <- rnHsDoc doc
250 return (DocCommentNamed str rn_doc)
251 rnDocDecl (DocGroup lev doc) = do
252 rn_doc <- rnHsDoc doc
253 return (DocGroup lev rn_doc)
257 %*********************************************************
259 Source-code fixity declarations
261 %*********************************************************
264 rnSrcFixityDecls :: [LFixitySig RdrName] -> RnM [LFixitySig Name]
265 -- Rename the fixity decls, so we can put
266 -- the renamed decls in the renamed syntax tree
267 -- Errors if the thing being fixed is not defined locally.
269 -- The returned FixitySigs are not actually used for anything,
270 -- except perhaps the GHCi API
271 rnSrcFixityDecls fix_decls
272 = do fix_decls <- mapM rn_decl fix_decls
273 return (concat fix_decls)
275 rn_decl :: LFixitySig RdrName -> RnM [LFixitySig Name]
276 -- GHC extension: look up both the tycon and data con
277 -- for con-like things; hence returning a list
278 -- If neither are in scope, report an error; otherwise
279 -- return a fixity sig for each (slightly odd)
280 rn_decl (L loc (FixitySig (L name_loc rdr_name) fixity))
281 = setSrcSpan name_loc $
282 -- this lookup will fail if the definition isn't local
283 do names <- lookupLocalDataTcNames rdr_name
284 return [ L loc (FixitySig (L name_loc name) fixity)
289 %*********************************************************
291 Source-code deprecations declarations
293 %*********************************************************
295 Check that the deprecated names are defined, are defined locally, and
296 that there are no duplicate deprecations.
298 It's only imported deprecations, dealt with in RnIfaces, that we
299 gather them together.
302 -- checks that the deprecations are defined locally, and that there are no duplicates
303 rnSrcWarnDecls :: [LWarnDecl RdrName] -> RnM Warnings
308 = do { -- check for duplicates
309 ; mappM_ (\ (lrdr:lrdr':_) -> addLocErr lrdr (dupWarnDecl lrdr')) warn_rdr_dups
310 ; mappM (addLocM rn_deprec) decls `thenM` \ pairs_s ->
311 returnM (WarnSome ((concat pairs_s))) }
313 rn_deprec (Warning rdr_name txt)
314 -- ensures that the names are defined locally
315 = lookupLocalDataTcNames rdr_name `thenM` \ names ->
316 returnM [(nameOccName name, txt) | name <- names]
318 -- look for duplicates among the OccNames;
319 -- we check that the names are defined above
320 -- invt: the lists returned by findDupsEq always have at least two elements
321 warn_rdr_dups = findDupsEq (\ x -> \ y -> rdrNameOcc (unLoc x) == rdrNameOcc (unLoc y))
322 (map (\ (L loc (Warning rdr_name _)) -> L loc rdr_name) decls)
324 dupWarnDecl :: Located RdrName -> RdrName -> SDoc
325 -- Located RdrName -> DeprecDecl RdrName -> SDoc
326 dupWarnDecl (L loc _) rdr_name
327 = vcat [ptext (sLit "Multiple warning declarations for") <+> quotes (ppr rdr_name),
328 ptext (sLit "also at ") <+> ppr loc]
332 %*********************************************************
334 \subsection{Source code declarations}
336 %*********************************************************
339 rnDefaultDecl :: DefaultDecl RdrName -> RnM (DefaultDecl Name, FreeVars)
340 rnDefaultDecl (DefaultDecl tys)
341 = mapFvRn (rnHsTypeFVs doc_str) tys `thenM` \ (tys', fvs) ->
342 returnM (DefaultDecl tys', fvs)
344 doc_str = text "In a `default' declaration"
347 %*********************************************************
349 \subsection{Foreign declarations}
351 %*********************************************************
354 rnHsForeignDecl :: ForeignDecl RdrName -> RnM (ForeignDecl Name, FreeVars)
355 rnHsForeignDecl (ForeignImport name ty spec)
356 = lookupLocatedTopBndrRn name `thenM` \ name' ->
357 rnHsTypeFVs (fo_decl_msg name) ty `thenM` \ (ty', fvs) ->
358 returnM (ForeignImport name' ty' spec, fvs)
360 rnHsForeignDecl (ForeignExport name ty spec)
361 = lookupLocatedOccRn name `thenM` \ name' ->
362 rnHsTypeFVs (fo_decl_msg name) ty `thenM` \ (ty', fvs) ->
363 returnM (ForeignExport name' ty' spec, fvs `addOneFV` unLoc name')
364 -- NB: a foreign export is an *occurrence site* for name, so
365 -- we add it to the free-variable list. It might, for example,
366 -- be imported from another module
368 fo_decl_msg :: Located RdrName -> SDoc
369 fo_decl_msg name = ptext (sLit "In the foreign declaration for") <+> ppr name
373 %*********************************************************
375 \subsection{Instance declarations}
377 %*********************************************************
380 rnSrcInstDecl :: InstDecl RdrName -> RnM (InstDecl Name, FreeVars)
381 rnSrcInstDecl (InstDecl inst_ty mbinds uprags ats)
382 -- Used for both source and interface file decls
383 = rnHsSigType (text "an instance decl") inst_ty `thenM` \ inst_ty' ->
385 -- Rename the bindings
386 -- The typechecker (not the renamer) checks that all
387 -- the bindings are for the right class
389 meth_doc = text "In the bindings in an instance declaration"
390 meth_names = collectHsBindLocatedBinders mbinds
391 (inst_tyvars, _, cls,_) = splitHsInstDeclTy (unLoc inst_ty')
393 checkDupRdrNames meth_doc meth_names `thenM_`
394 -- Check that the same method is not given twice in the
395 -- same instance decl instance C T where
399 -- We must use checkDupRdrNames because the Name of the
400 -- method is the Name of the class selector, whose SrcSpan
401 -- points to the class declaration
403 extendTyVarEnvForMethodBinds inst_tyvars (
404 -- (Slightly strangely) the forall-d tyvars scope over
405 -- the method bindings too
406 rnMethodBinds cls (\_ -> []) -- No scoped tyvars
408 ) `thenM` \ (mbinds', meth_fvs) ->
409 -- Rename the associated types
410 -- The typechecker (not the renamer) checks that all
411 -- the declarations are for the right class
413 at_doc = text "In the associated types of an instance declaration"
414 at_names = map (head . tyClDeclNames . unLoc) ats
416 checkDupRdrNames at_doc at_names `thenM_`
417 -- See notes with checkDupRdrNames for methods, above
419 rnATInsts ats `thenM` \ (ats', at_fvs) ->
421 -- Rename the prags and signatures.
422 -- Note that the type variables are not in scope here,
423 -- so that instance Eq a => Eq (T a) where
424 -- {-# SPECIALISE instance Eq a => Eq (T [a]) #-}
427 -- But the (unqualified) method names are in scope
429 binders = collectHsBindBinders mbinds'
430 bndr_set = mkNameSet binders
432 bindLocalNames binders
433 (renameSigs (Just bndr_set) okInstDclSig uprags) `thenM` \ uprags' ->
435 returnM (InstDecl inst_ty' mbinds' uprags' ats',
436 meth_fvs `plusFV` at_fvs
437 `plusFV` hsSigsFVs uprags'
438 `plusFV` extractHsTyNames inst_ty')
439 -- We return the renamed associated data type declarations so
440 -- that they can be entered into the list of type declarations
441 -- for the binding group, but we also keep a copy in the instance.
442 -- The latter is needed for well-formedness checks in the type
443 -- checker (eg, to ensure that all ATs of the instance actually
444 -- receive a declaration).
445 -- NB: Even the copies in the instance declaration carry copies of
446 -- the instance context after renaming. This is a bit
447 -- strange, but should not matter (and it would be more work
448 -- to remove the context).
451 Renaming of the associated types in instances.
454 rnATInsts :: [LTyClDecl RdrName] -> RnM ([LTyClDecl Name], FreeVars)
455 rnATInsts atDecls = rnList rnATInst atDecls
457 rnATInst tydecl@TyData {} = rnTyClDecl tydecl
458 rnATInst tydecl@TySynonym {} = rnTyClDecl tydecl
460 pprPanic "RnSource.rnATInsts: invalid AT instance"
461 (ppr (tcdName tydecl))
464 For the method bindings in class and instance decls, we extend the
465 type variable environment iff -fglasgow-exts
468 extendTyVarEnvForMethodBinds :: [LHsTyVarBndr Name]
469 -> RnM (Bag (LHsBind Name), FreeVars)
470 -> RnM (Bag (LHsBind Name), FreeVars)
471 extendTyVarEnvForMethodBinds tyvars thing_inside
472 = do { scoped_tvs <- doptM Opt_ScopedTypeVariables
474 extendTyVarEnvFVRn (map hsLTyVarName tyvars) thing_inside
479 %*********************************************************
481 \subsection{Stand-alone deriving declarations}
483 %*********************************************************
486 rnSrcDerivDecl :: DerivDecl RdrName -> RnM (DerivDecl Name, FreeVars)
487 rnSrcDerivDecl (DerivDecl ty)
488 = do ty' <- rnLHsType (text "a deriving decl") ty
489 let fvs = extractHsTyNames ty'
490 return (DerivDecl ty', fvs)
493 %*********************************************************
497 %*********************************************************
500 rnHsRuleDecl :: RuleDecl RdrName -> RnM (RuleDecl Name, FreeVars)
501 rnHsRuleDecl (HsRule rule_name act vars lhs _fv_lhs rhs _fv_rhs)
502 = bindPatSigTyVarsFV (collectRuleBndrSigTys vars) $
503 bindLocatedLocalsFV doc (map get_var vars) $ \ ids ->
504 do { (vars', fv_vars) <- mapFvRn rn_var (vars `zip` ids)
505 -- NB: The binders in a rule are always Ids
506 -- We don't (yet) support type variables
508 ; (lhs', fv_lhs') <- rnLExpr lhs
509 ; (rhs', fv_rhs') <- rnLExpr rhs
511 ; checkValidRule rule_name ids lhs' fv_lhs'
513 ; return (HsRule rule_name act vars' lhs' fv_lhs' rhs' fv_rhs',
514 fv_vars `plusFV` fv_lhs' `plusFV` fv_rhs') }
516 doc = text "In the transformation rule" <+> ftext rule_name
518 get_var (RuleBndr v) = v
519 get_var (RuleBndrSig v _) = v
521 rn_var (RuleBndr (L loc _), id)
522 = returnM (RuleBndr (L loc id), emptyFVs)
523 rn_var (RuleBndrSig (L loc _) t, id)
524 = rnHsTypeFVs doc t `thenM` \ (t', fvs) ->
525 returnM (RuleBndrSig (L loc id) t', fvs)
527 badRuleVar :: FastString -> Name -> SDoc
529 = sep [ptext (sLit "Rule") <+> doubleQuotes (ftext name) <> colon,
530 ptext (sLit "Forall'd variable") <+> quotes (ppr var) <+>
531 ptext (sLit "does not appear on left hand side")]
534 Note [Rule LHS validity checking]
535 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
536 Check the shape of a transformation rule LHS. Currently we only allow
537 LHSs of the form @(f e1 .. en)@, where @f@ is not one of the
538 @forall@'d variables.
540 We used restrict the form of the 'ei' to prevent you writing rules
541 with LHSs with a complicated desugaring (and hence unlikely to match);
542 (e.g. a case expression is not allowed: too elaborate.)
544 But there are legitimate non-trivial args ei, like sections and
545 lambdas. So it seems simmpler not to check at all, and that is why
546 check_e is commented out.
549 checkValidRule :: FastString -> [Name] -> LHsExpr Name -> NameSet -> RnM ()
550 checkValidRule rule_name ids lhs' fv_lhs'
551 = do { -- Check for the form of the LHS
552 case (validRuleLhs ids lhs') of
554 Just bad -> failWithTc (badRuleLhsErr rule_name lhs' bad)
556 -- Check that LHS vars are all bound
557 ; let bad_vars = [var | var <- ids, not (var `elemNameSet` fv_lhs')]
558 ; mapM_ (addErr . badRuleVar rule_name) bad_vars }
560 validRuleLhs :: [Name] -> LHsExpr Name -> Maybe (HsExpr Name)
562 -- Just e => Not ok, and e is the offending expression
563 validRuleLhs foralls lhs
566 checkl (L _ e) = check e
568 check (OpApp e1 op _ e2) = checkl op `mplus` checkl_e e1 `mplus` checkl_e e2
569 check (HsApp e1 e2) = checkl e1 `mplus` checkl_e e2
570 check (HsVar v) | v `notElem` foralls = Nothing
571 check other = Just other -- Failure
574 checkl_e (L _ _e) = Nothing -- Was (check_e e); see Note [Rule LHS validity checking]
576 {- Commented out; see Note [Rule LHS validity checking] above
577 check_e (HsVar v) = Nothing
578 check_e (HsPar e) = checkl_e e
579 check_e (HsLit e) = Nothing
580 check_e (HsOverLit e) = Nothing
582 check_e (OpApp e1 op _ e2) = checkl_e e1 `mplus` checkl_e op `mplus` checkl_e e2
583 check_e (HsApp e1 e2) = checkl_e e1 `mplus` checkl_e e2
584 check_e (NegApp e _) = checkl_e e
585 check_e (ExplicitList _ es) = checkl_es es
586 check_e (ExplicitTuple es _) = checkl_es es
587 check_e other = Just other -- Fails
589 checkl_es es = foldr (mplus . checkl_e) Nothing es
592 badRuleLhsErr :: FastString -> LHsExpr Name -> HsExpr Name -> SDoc
593 badRuleLhsErr name lhs bad_e
594 = sep [ptext (sLit "Rule") <+> ftext name <> colon,
595 nest 4 (vcat [ptext (sLit "Illegal expression:") <+> ppr bad_e,
596 ptext (sLit "in left-hand side:") <+> ppr lhs])]
598 ptext (sLit "LHS must be of form (f e1 .. en) where f is not forall'd")
602 %*********************************************************
604 \subsection{Type, class and iface sig declarations}
606 %*********************************************************
608 @rnTyDecl@ uses the `global name function' to create a new type
609 declaration in which local names have been replaced by their original
610 names, reporting any unknown names.
612 Renaming type variables is a pain. Because they now contain uniques,
613 it is necessary to pass in an association list which maps a parsed
614 tyvar to its @Name@ representation.
615 In some cases (type signatures of values),
616 it is even necessary to go over the type first
617 in order to get the set of tyvars used by it, make an assoc list,
618 and then go over it again to rename the tyvars!
619 However, we can also do some scoping checks at the same time.
622 rnTyClDecl :: TyClDecl RdrName -> RnM (TyClDecl Name, FreeVars)
623 rnTyClDecl (ForeignType {tcdLName = name, tcdFoType = fo_type, tcdExtName = ext_name})
624 = lookupLocatedTopBndrRn name `thenM` \ name' ->
625 returnM (ForeignType {tcdLName = name', tcdFoType = fo_type, tcdExtName = ext_name},
628 -- all flavours of type family declarations ("type family", "newtype fanily",
629 -- and "data family")
630 rnTyClDecl (tydecl@TyFamily {}) =
631 rnFamily tydecl bindTyVarsRn
633 -- "data", "newtype", "data instance, and "newtype instance" declarations
634 rnTyClDecl (tydecl@TyData {tcdND = new_or_data, tcdCtxt = context,
635 tcdLName = tycon, tcdTyVars = tyvars,
636 tcdTyPats = typatsMaybe, tcdCons = condecls,
637 tcdKindSig = sig, tcdDerivs = derivs})
638 | is_vanilla -- Normal Haskell data type decl
639 = ASSERT( isNothing sig ) -- In normal H98 form, kind signature on the
640 -- data type is syntactically illegal
641 bindTyVarsRn data_doc tyvars $ \ tyvars' ->
642 do { tycon' <- if isFamInstDecl tydecl
643 then lookupLocatedOccRn tycon -- may be imported family
644 else lookupLocatedTopBndrRn tycon
645 ; context' <- rnContext data_doc context
646 ; typats' <- rnTyPats data_doc typatsMaybe
647 ; (derivs', deriv_fvs) <- rn_derivs derivs
648 ; condecls' <- rnConDecls (unLoc tycon') condecls
649 -- No need to check for duplicate constructor decls
650 -- since that is done by RnNames.extendGlobalRdrEnvRn
651 ; returnM (TyData {tcdND = new_or_data, tcdCtxt = context',
652 tcdLName = tycon', tcdTyVars = tyvars',
653 tcdTyPats = typats', tcdKindSig = Nothing,
654 tcdCons = condecls', tcdDerivs = derivs'},
655 delFVs (map hsLTyVarName tyvars') $
656 extractHsCtxtTyNames context' `plusFV`
657 plusFVs (map conDeclFVs condecls') `plusFV`
659 (if isFamInstDecl tydecl
660 then unitFV (unLoc tycon') -- type instance => use
665 = ASSERT( none typatsMaybe ) -- GADTs cannot have type patterns for now
666 do { tycon' <- if isFamInstDecl tydecl
667 then lookupLocatedOccRn tycon -- may be imported family
668 else lookupLocatedTopBndrRn tycon
669 ; checkTc (null (unLoc context)) (badGadtStupidTheta tycon)
670 ; tyvars' <- bindTyVarsRn data_doc tyvars
671 (\ tyvars' -> return tyvars')
672 -- For GADTs, the type variables in the declaration
673 -- do not scope over the constructor signatures
674 -- data T a where { T1 :: forall b. b-> b }
675 ; (derivs', deriv_fvs) <- rn_derivs derivs
676 ; condecls' <- rnConDecls (unLoc tycon') condecls
677 -- No need to check for duplicate constructor decls
678 -- since that is done by RnNames.extendGlobalRdrEnvRn
679 ; returnM (TyData {tcdND = new_or_data, tcdCtxt = noLoc [],
680 tcdLName = tycon', tcdTyVars = tyvars',
681 tcdTyPats = Nothing, tcdKindSig = sig,
682 tcdCons = condecls', tcdDerivs = derivs'},
683 plusFVs (map conDeclFVs condecls') `plusFV`
685 (if isFamInstDecl tydecl
686 then unitFV (unLoc tycon') -- type instance => use
690 is_vanilla = case condecls of -- Yuk
692 L _ (ConDecl { con_res = ResTyH98 }) : _ -> True
696 none (Just []) = True
699 data_doc = text "In the data type declaration for" <+> quotes (ppr tycon)
701 rn_derivs Nothing = returnM (Nothing, emptyFVs)
702 rn_derivs (Just ds) = rnLHsTypes data_doc ds `thenM` \ ds' ->
703 returnM (Just ds', extractHsTyNames_s ds')
705 -- "type" and "type instance" declarations
706 rnTyClDecl tydecl@(TySynonym {tcdLName = name, tcdTyVars = tyvars,
707 tcdTyPats = typatsMaybe, tcdSynRhs = ty})
708 = bindTyVarsRn syn_doc tyvars $ \ tyvars' ->
709 do { name' <- if isFamInstDecl tydecl
710 then lookupLocatedOccRn name -- may be imported family
711 else lookupLocatedTopBndrRn name
712 ; typats' <- rnTyPats syn_doc typatsMaybe
713 ; (ty', fvs) <- rnHsTypeFVs syn_doc ty
714 ; returnM (TySynonym {tcdLName = name', tcdTyVars = tyvars',
715 tcdTyPats = typats', tcdSynRhs = ty'},
716 delFVs (map hsLTyVarName tyvars') $
718 (if isFamInstDecl tydecl
719 then unitFV (unLoc name') -- type instance => use
723 syn_doc = text "In the declaration for type synonym" <+> quotes (ppr name)
725 rnTyClDecl (ClassDecl {tcdCtxt = context, tcdLName = cname,
726 tcdTyVars = tyvars, tcdFDs = fds, tcdSigs = sigs,
727 tcdMeths = mbinds, tcdATs = ats, tcdDocs = docs})
728 = do { cname' <- lookupLocatedTopBndrRn cname
730 -- Tyvars scope over superclass context and method signatures
731 ; (tyvars', context', fds', ats', ats_fvs, sigs')
732 <- bindTyVarsRn cls_doc tyvars $ \ tyvars' -> do
733 { context' <- rnContext cls_doc context
734 ; fds' <- rnFds cls_doc fds
735 ; (ats', ats_fvs) <- rnATs ats
736 ; sigs' <- renameSigs Nothing okClsDclSig sigs
737 ; return (tyvars', context', fds', ats', ats_fvs, sigs') }
739 -- No need to check for duplicate associated type decls
740 -- since that is done by RnNames.extendGlobalRdrEnvRn
742 -- Check the signatures
743 -- First process the class op sigs (op_sigs), then the fixity sigs (non_op_sigs).
744 ; let sig_rdr_names_w_locs = [op | L _ (TypeSig op _) <- sigs]
745 ; checkDupRdrNames sig_doc sig_rdr_names_w_locs
746 -- Typechecker is responsible for checking that we only
747 -- give default-method bindings for things in this class.
748 -- The renamer *could* check this for class decls, but can't
749 -- for instance decls.
751 -- The newLocals call is tiresome: given a generic class decl
754 -- op {| x+y |} (Inl a) = ...
755 -- op {| x+y |} (Inr b) = ...
756 -- op {| a*b |} (a*b) = ...
757 -- we want to name both "x" tyvars with the same unique, so that they are
758 -- easy to group together in the typechecker.
759 ; (mbinds', meth_fvs)
760 <- extendTyVarEnvForMethodBinds tyvars' $ do
761 { name_env <- getLocalRdrEnv
762 ; let gen_rdr_tyvars_w_locs = [ tv | tv <- extractGenericPatTyVars mbinds,
763 not (unLoc tv `elemLocalRdrEnv` name_env) ]
764 -- No need to check for duplicate method signatures
765 -- since that is done by RnNames.extendGlobalRdrEnvRn
766 -- and the methods are already in scope
767 ; gen_tyvars <- newLocalsRn gen_rdr_tyvars_w_locs
768 ; rnMethodBinds (unLoc cname') (mkSigTvFn sigs') gen_tyvars mbinds }
771 ; docs' <- mapM (wrapLocM rnDocDecl) docs
773 ; return (ClassDecl { tcdCtxt = context', tcdLName = cname',
774 tcdTyVars = tyvars', tcdFDs = fds', tcdSigs = sigs',
775 tcdMeths = mbinds', tcdATs = ats', tcdDocs = docs'},
777 delFVs (map hsLTyVarName tyvars') $
778 extractHsCtxtTyNames context' `plusFV`
779 plusFVs (map extractFunDepNames (map unLoc fds')) `plusFV`
780 hsSigsFVs sigs' `plusFV`
784 cls_doc = text "In the declaration for class" <+> ppr cname
785 sig_doc = text "In the signatures for class" <+> ppr cname
787 badGadtStupidTheta :: Located RdrName -> SDoc
789 = vcat [ptext (sLit "No context is allowed on a GADT-style data declaration"),
790 ptext (sLit "(You can put a context on each contructor, though.)")]
793 %*********************************************************
795 \subsection{Support code for type/data declarations}
797 %*********************************************************
800 -- Although, we are processing type patterns here, all type variables will
801 -- already be in scope (they are the same as in the 'tcdTyVars' field of the
802 -- type declaration to which these patterns belong)
804 rnTyPats :: SDoc -> Maybe [LHsType RdrName] -> RnM (Maybe [LHsType Name])
805 rnTyPats _ Nothing = return Nothing
806 rnTyPats doc (Just typats) = liftM Just $ rnLHsTypes doc typats
808 rnConDecls :: Name -> [LConDecl RdrName] -> RnM [LConDecl Name]
809 rnConDecls _tycon condecls
810 = mappM (wrapLocM rnConDecl) condecls
812 rnConDecl :: ConDecl RdrName -> RnM (ConDecl Name)
813 rnConDecl (ConDecl name expl tvs cxt details res_ty mb_doc)
814 = do { addLocM checkConName name
816 ; new_name <- lookupLocatedTopBndrRn name
817 ; name_env <- getLocalRdrEnv
819 -- For H98 syntax, the tvs are the existential ones
820 -- For GADT syntax, the tvs are all the quantified tyvars
821 -- Hence the 'filter' in the ResTyH98 case only
822 ; let not_in_scope = not . (`elemLocalRdrEnv` name_env) . unLoc
823 arg_tys = hsConDeclArgTys details
824 implicit_tvs = case res_ty of
825 ResTyH98 -> filter not_in_scope $
827 ResTyGADT ty -> get_rdr_tvs (ty : arg_tys)
830 Implicit -> userHsTyVarBndrs implicit_tvs
832 ; mb_doc' <- rnMbLHsDoc mb_doc
834 ; bindTyVarsRn doc tvs' $ \new_tyvars -> do
835 { new_context <- rnContext doc cxt
836 ; new_details <- rnConDeclDetails doc details
837 ; (new_details', new_res_ty) <- rnConResult doc new_details res_ty
838 ; return (ConDecl new_name expl new_tyvars new_context new_details' new_res_ty mb_doc') }}
840 doc = text "In the definition of data constructor" <+> quotes (ppr name)
841 get_rdr_tvs tys = extractHsRhoRdrTyVars cxt (noLoc (HsTupleTy Boxed tys))
844 -> HsConDetails (LHsType Name) [ConDeclField Name]
846 -> RnM (HsConDetails (LHsType Name) [ConDeclField Name],
848 rnConResult _ details ResTyH98 = return (details, ResTyH98)
850 rnConResult doc details (ResTyGADT ty) = do
851 ty' <- rnHsSigType doc ty
852 let (arg_tys, res_ty) = splitHsFunType ty'
853 -- We can split it up, now the renamer has dealt with fixities
855 PrefixCon _xs -> ASSERT( null _xs ) return (PrefixCon arg_tys, ResTyGADT res_ty)
856 RecCon _ -> return (details, ResTyGADT ty')
857 InfixCon {} -> panic "rnConResult"
859 rnConDeclDetails :: SDoc
860 -> HsConDetails (LHsType RdrName) [ConDeclField RdrName]
861 -> RnM (HsConDetails (LHsType Name) [ConDeclField Name])
862 rnConDeclDetails doc (PrefixCon tys)
863 = mappM (rnLHsType doc) tys `thenM` \ new_tys ->
864 returnM (PrefixCon new_tys)
866 rnConDeclDetails doc (InfixCon ty1 ty2)
867 = rnLHsType doc ty1 `thenM` \ new_ty1 ->
868 rnLHsType doc ty2 `thenM` \ new_ty2 ->
869 returnM (InfixCon new_ty1 new_ty2)
871 rnConDeclDetails doc (RecCon fields)
872 = do { new_fields <- mappM (rnField doc) fields
873 -- No need to check for duplicate fields
874 -- since that is done by RnNames.extendGlobalRdrEnvRn
875 ; return (RecCon new_fields) }
877 rnField :: SDoc -> ConDeclField RdrName -> RnM (ConDeclField Name)
878 rnField doc (ConDeclField name ty haddock_doc)
879 = lookupLocatedTopBndrRn name `thenM` \ new_name ->
880 rnLHsType doc ty `thenM` \ new_ty ->
881 rnMbLHsDoc haddock_doc `thenM` \ new_haddock_doc ->
882 returnM (ConDeclField new_name new_ty new_haddock_doc)
884 -- Rename family declarations
886 -- * This function is parametrised by the routine handling the index
887 -- variables. On the toplevel, these are defining occurences, whereas they
888 -- are usage occurences for associated types.
890 rnFamily :: TyClDecl RdrName
891 -> (SDoc -> [LHsTyVarBndr RdrName] ->
892 ([LHsTyVarBndr Name] -> RnM (TyClDecl Name, FreeVars)) ->
893 RnM (TyClDecl Name, FreeVars))
894 -> RnM (TyClDecl Name, FreeVars)
896 rnFamily (tydecl@TyFamily {tcdFlavour = flavour,
897 tcdLName = tycon, tcdTyVars = tyvars})
899 do { checkM (isDataFlavour flavour -- for synonyms,
900 || not (null tyvars)) $ addErr needOneIdx -- no. of indexes >= 1
901 ; bindIdxVars (family_doc tycon) tyvars $ \tyvars' -> do {
902 ; tycon' <- lookupLocatedTopBndrRn tycon
903 ; returnM (TyFamily {tcdFlavour = flavour, tcdLName = tycon',
904 tcdTyVars = tyvars', tcdKind = tcdKind tydecl},
908 isDataFlavour DataFamily = True
909 isDataFlavour _ = False
910 rnFamily d _ = pprPanic "rnFamily" (ppr d)
912 family_doc :: Located RdrName -> SDoc
913 family_doc tycon = text "In the family declaration for" <+> quotes (ppr tycon)
916 needOneIdx = text "Type family declarations requires at least one type index"
918 -- Rename associated type declarations (in classes)
920 -- * This can be family declarations and (default) type instances
922 rnATs :: [LTyClDecl RdrName] -> RnM ([LTyClDecl Name], FreeVars)
923 rnATs ats = mapFvRn (wrapLocFstM rn_at) ats
925 rn_at (tydecl@TyFamily {}) = rnFamily tydecl lookupIdxVars
926 rn_at (tydecl@TySynonym {}) =
928 checkM (isNothing (tcdTyPats tydecl)) $ addErr noPatterns
930 rn_at _ = panic "RnSource.rnATs: invalid TyClDecl"
932 lookupIdxVars _ tyvars cont =
933 do { checkForDups tyvars;
934 ; tyvars' <- mappM lookupIdxVar tyvars
937 -- Type index variables must be class parameters, which are the only
938 -- type variables in scope at this point.
939 lookupIdxVar (L l tyvar) =
941 name' <- lookupOccRn (hsTyVarName tyvar)
942 return $ L l (replaceTyVarName tyvar name')
944 -- Type variable may only occur once.
946 checkForDups [] = return ()
947 checkForDups (L loc tv:ltvs) =
948 do { setSrcSpan loc $
949 when (hsTyVarName tv `ltvElem` ltvs) $
950 addErr (repeatedTyVar tv)
954 _ `ltvElem` [] = False
955 rdrName `ltvElem` (L _ tv:ltvs)
956 | rdrName == hsTyVarName tv = True
957 | otherwise = rdrName `ltvElem` ltvs
960 noPatterns = text "Default definition for an associated synonym cannot have"
961 <+> text "type pattern"
963 repeatedTyVar :: HsTyVarBndr RdrName -> SDoc
964 repeatedTyVar tv = ptext (sLit "Illegal repeated type variable") <+>
967 -- This data decl will parse OK
969 -- treating "a" as the constructor.
970 -- It is really hard to make the parser spot this malformation.
971 -- So the renamer has to check that the constructor is legal
973 -- We can get an operator as the constructor, even in the prefix form:
974 -- data T = :% Int Int
975 -- from interface files, which always print in prefix form
977 checkConName :: RdrName -> TcRn ()
978 checkConName name = checkErr (isRdrDataCon name) (badDataCon name)
980 badDataCon :: RdrName -> SDoc
982 = hsep [ptext (sLit "Illegal data constructor name"), quotes (ppr name)]
986 %*********************************************************
988 \subsection{Support code for type/data declarations}
990 %*********************************************************
992 Get the mapping from constructors to fields for this module.
993 It's convenient to do this after the data type decls have been renamed
995 extendRecordFieldEnv :: [LTyClDecl RdrName] -> TcM TcGblEnv
996 extendRecordFieldEnv decls
997 = do { tcg_env <- getGblEnv
998 ; field_env' <- foldrM get (tcg_field_env tcg_env) decls
999 ; return (tcg_env { tcg_field_env = field_env' }) }
1001 -- we want to lookup:
1002 -- (a) a datatype constructor
1003 -- (b) a record field
1004 -- knowing that they're from this module.
1005 -- lookupLocatedTopBndrRn does this, because it does a lookupGreLocalRn,
1006 -- which keeps only the local ones.
1007 lookup x = do { x' <- lookupLocatedTopBndrRn x
1008 ; return $ unLoc x'}
1010 get (L _ (TyData { tcdCons = cons })) env = foldrM get_con env cons
1011 get _ env = return env
1013 get_con (L _ (ConDecl { con_name = con, con_details = RecCon flds })) env
1014 = do { con' <- lookup con
1015 ; flds' <- mappM lookup (map cd_fld_name flds)
1016 ; return $ extendNameEnv env con' flds' }
1021 %*********************************************************
1023 \subsection{Support code to rename types}
1025 %*********************************************************
1028 rnFds :: SDoc -> [Located (FunDep RdrName)] -> RnM [Located (FunDep Name)]
1031 = mappM (wrapLocM rn_fds) fds
1034 = rnHsTyVars doc tys1 `thenM` \ tys1' ->
1035 rnHsTyVars doc tys2 `thenM` \ tys2' ->
1036 returnM (tys1', tys2')
1038 rnHsTyVars :: SDoc -> [RdrName] -> RnM [Name]
1039 rnHsTyVars doc tvs = mappM (rnHsTyVar doc) tvs
1041 rnHsTyVar :: SDoc -> RdrName -> RnM Name
1042 rnHsTyVar _doc tyvar = lookupOccRn tyvar
1046 %*********************************************************
1050 %*********************************************************
1056 h = ...$(thing "f")...
1058 The splice can expand into literally anything, so when we do dependency
1059 analysis we must assume that it might mention 'f'. So we simply treat
1060 all locally-defined names as mentioned by any splice. This is terribly
1061 brutal, but I don't see what else to do. For example, it'll mean
1062 that every locally-defined thing will appear to be used, so no unused-binding
1063 warnings. But if we miss the dependency, then we might typecheck 'h' before 'f',
1064 and that will crash the type checker because 'f' isn't in scope.
1066 Currently, I'm not treating a splice as also mentioning every import,
1067 which is a bit inconsistent -- but there are a lot of them. We might
1068 thereby get some bogus unused-import warnings, but we won't crash the
1069 type checker. Not very satisfactory really.
1072 rnSplice :: HsSplice RdrName -> RnM (HsSplice Name, FreeVars)
1073 rnSplice (HsSplice n expr)
1074 = do { checkTH expr "splice"
1075 ; loc <- getSrcSpanM
1076 ; [n'] <- newLocalsRn [L loc n]
1077 ; (expr', fvs) <- rnLExpr expr
1079 -- Ugh! See Note [Splices] above
1080 ; lcl_rdr <- getLocalRdrEnv
1081 ; gbl_rdr <- getGlobalRdrEnv
1082 ; let gbl_names = mkNameSet [gre_name gre | gre <- globalRdrEnvElts gbl_rdr,
1084 lcl_names = mkNameSet (occEnvElts lcl_rdr)
1086 ; return (HsSplice n' expr', fvs `plusFV` lcl_names `plusFV` gbl_names) }
1088 checkTH :: Outputable a => a -> String -> RnM ()
1090 checkTH _ _ = returnM () -- OK
1092 checkTH e what -- Raise an error in a stage-1 compiler
1093 = addErr (vcat [ptext (sLit "Template Haskell") <+> text what <+>
1094 ptext (sLit "illegal in a stage-1 compiler"),