type ExportAccum -- The type of the accumulating parameter of
-- the main worker function in rnExports
= ([LIE Name], -- Export items with Names
- ExportOccMap, -- Tracks exported occurrence names
+ ExportOccMap, -- Tracks exported occurrence names
[AvailInfo]) -- The accumulated exported stuff
-- Not nub'd!
emptyExportAccum :: ExportAccum
emptyExportAccum = ([], emptyOccEnv, [])
-type ExportOccMap = OccEnv (Name, IE RdrName)
+type ExportOccMap = OccEnv (Name, IE Name)
-- Tracks what a particular exported OccName
-- in an export list refers to, and which item
-- it came from. It's illegal to export two distinct things
exports_from_item :: ExportAccum -> LIE RdrName -> RnM ExportAccum
exports_from_item acc@(ie_names, occs, exports)
- (L loc ie@(IEModuleContents mod))
+ (L loc (IEModuleContents mod))
| let earlier_mods = [ mod | (L _ (IEModuleContents mod)) <- ie_names ]
, mod `elem` earlier_mods -- Duplicate export of M
= do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ;
-- The qualified and unqualified version of all of
-- these names are, in effect, used by this export
- ; occs' <- check_occs ie occs names
+ ; occs' <- check_occs (IEModuleContents mod) occs names
-- This check_occs not only finds conflicts
-- between this item and others, but also
-- internally within this item. That is, if
then return acc -- Avoid error cascade
else do
- occs' <- check_occs ie occs (availNames avail)
+ occs' <- check_occs new_ie occs (availNames avail)
return (L loc new_ie : lie_names, occs', avail : exports)
Imported is -> any unQualSpecOK is && any (qualSpecOK mod) is
-------------------------------
-check_occs :: IE RdrName -> ExportOccMap -> [Name] -> RnM ExportOccMap
-check_occs ie occs names
+check_occs :: IE Name -> ExportOccMap -> [Name] -> RnM ExportOccMap
+check_occs ie occs names -- 'names' are the entities specifed by 'ie'
= foldlM check occs names
where
check occs name
| name == name' -- Duplicate export
-- But we don't want to warn if the same thing is exported
-- by two different module exports. See ticket #4478.
- -> do unless (diffModules ie ie') $ do
+ -> do unless (dupExport_ok name ie ie') $ do
warn_dup_exports <- doptM Opt_WarnDuplicateExports
warnIf warn_dup_exports (dupExportWarn name_occ ie ie')
return occs
return occs }
where
name_occ = nameOccName name
- -- True if the two IE RdrName are different module exports.
- diffModules (IEModuleContents n1) (IEModuleContents n2) = n1 /= n2
- diffModules _ _ = False
+
+
+dupExport_ok :: Name -> IE Name -> IE Name -> Bool
+-- The Name is exported by both IEs. Is that ok?
+-- "No" iff the name is mentioned explicitly in both IEs
+-- "Yes" otherwise
+--
+-- Example of "no": module M( f, f )
+--
+-- Example of "yes"
+-- module M( module A, module B ) where
+-- import A( f )
+-- import B( f )
+--
+-- Example of "yes" (Trac #2436)
+-- module M( C(..), T(..) ) where
+-- class C a where { data T a }
+-- instace C Int where { data T Int = TInt }
+--
+-- Example of "yes" (Trac #2436)
+-- module Foo ( T ) where
+-- data family T a
+-- module Bar ( T(..), module Foo ) where
+-- import Foo
+-- data instance T Int = TInt
+
+dupExport_ok n ie1 ie2
+ = not (explicit_in ie1 && explicit_in ie2)
+ where
+ explicit_in (IEModuleContents _) = False
+ explicit_in (IEThingAll n') = n == n'
+ explicit_in _ = True
\end{code}
%*********************************************************
= sep [ ptext (sLit "Using 'type' tag on") <+> quotes (ppr name) <+> wherestr,
ptext (sLit "Use -XTypeFamilies to enable this extension") ]
-exportClashErr :: GlobalRdrEnv -> Name -> Name -> IE RdrName -> IE RdrName
+exportClashErr :: GlobalRdrEnv -> Name -> Name -> IE Name -> IE Name
-> Message
exportClashErr global_env name1 name2 ie1 ie2
= vcat [ ptext (sLit "Conflicting exports for") <+> quotes (ppr occ) <> colon
where
sorted_names = sortWith nameSrcLoc names
-dupExportWarn :: OccName -> IE RdrName -> IE RdrName -> SDoc
+dupExportWarn :: OccName -> IE Name -> IE Name -> SDoc
dupExportWarn occ_name ie1 ie2
= hsep [quotes (ppr occ_name),
ptext (sLit "is exported by"), quotes (ppr ie1),