(source, ordinary) = partition is_source_import all_imports
is_source_import (ImportDecl _ ImportByUserSource _ _ _ _) = True
is_source_import other = False
+
+ get_imports = importsFromImportDecl this_mod_name rec_unqual_fn
in
- mapAndUnzipRn (importsFromImportDecl rec_unqual_fn) ordinary `thenRn` \ (imp_gbl_envs1, imp_avails_s1) ->
- mapAndUnzipRn (importsFromImportDecl rec_unqual_fn) source `thenRn` \ (imp_gbl_envs2, imp_avails_s2) ->
+ mapAndUnzipRn get_imports ordinary `thenRn` \ (imp_gbl_envs1, imp_avails_s1) ->
+ mapAndUnzipRn get_imports source `thenRn` \ (imp_gbl_envs2, imp_avails_s2) ->
-- COMBINE RESULTS
-- We put the local env second, so that a local provenance
\end{code}
\begin{code}
-importsFromImportDecl :: (Name -> Bool) -- OK to omit qualifier
+importsFromImportDecl :: ModuleName
+ -> (Name -> Bool) -- OK to omit qualifier
-> RdrNameImportDecl
-> RnMG (GlobalRdrEnv,
ExportAvails)
-importsFromImportDecl is_unqual (ImportDecl imp_mod_name from qual_only as_mod import_spec iloc)
+importsFromImportDecl this_mod_name is_unqual (ImportDecl imp_mod_name from qual_only as_mod import_spec iloc)
= pushSrcLocRn iloc $
getInterfaceExports imp_mod_name from `thenRn` \ (imp_mod, avails_by_module) ->
let
avails :: Avails
- avails = concat (map snd avails_by_module)
+ avails = [ avail | (mod_name, avails) <- avails_by_module,
+ mod_name /= this_mod_name,
+ avail <- avails ]
+ -- If the module exports anything defined in this module, just ignore it.
+ -- Reason: otherwise it looks as if there are two local definition sites
+ -- for the thing, and an error gets reported. Easiest thing is just to
+ -- filter them out up front. This situation only arises if a module
+ -- imports itself, or another module that imported it. (Necessarily,
+ -- this invoves a loop.)
+ --
+ -- Tiresome consequence: if you say
+ -- module A where
+ -- import B( AType )
+ -- type AType = ...
+ --
+ -- module B( AType ) where
+ -- import {-# SOURCE #-} A( AType )
+ --
+ -- then you'll get a 'B does not export AType' message. Oh well.
+
in
- filterImports imp_mod_name import_spec avails `thenRn` \ (filtered_avails, hides, explicits) ->
+ filterImports imp_mod_name from import_spec avails `thenRn` \ (filtered_avails, hides, explicits) ->
let
mk_provenance name = NonLocalDef (UserImport imp_mod iloc (name `elemNameSet` explicits))
\begin{code}
filterImports :: ModuleName -- The module being imported
+ -> WhereFrom -- Tells whether it's a {-# SOURCE #-} import
-> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hiding
-> [AvailInfo] -- What's available
-> RnMG ([AvailInfo], -- What's actually imported
-- Complains if import spec mentions things that the module doesn't export
-- Warns/informs if import spec contains duplicates.
-filterImports mod Nothing imports
+filterImports mod from Nothing imports
= returnRn (imports, [], emptyNameSet)
-filterImports mod (Just (want_hiding, import_items)) total_avails
+filterImports mod from (Just (want_hiding, import_items)) total_avails
= flatMapRn get_item import_items `thenRn` \ avails_w_explicits ->
let
(item_avails, explicits_s) = unzip avails_w_explicits
-- they won't make any difference because naked entities like T
-- in an import list map to TcOccs, not VarOccs.
- bale_out item = addErrRn (badImportItemErr mod item) `thenRn_`
+ bale_out item = addErrRn (badImportItemErr mod from item) `thenRn_`
returnRn []
get_item item@(IEModuleContents _) = bale_out item
returnRn (mod:mods, occs', avails')
exports_from_item warn_dups acc@(mods, occs, avails) ie
- | not (maybeToBool maybe_in_scope)
- = failWithRn acc (unknownNameErr (ieName ie))
-
- | not (null dup_names)
- = addNameClashErrRn rdr_name ((name,prov):dup_names) `thenRn_`
- returnRn acc
+ = lookupSrcName global_name_env (ieName ie) `thenRn` \ name ->
-#ifdef DEBUG
- -- I can't see why this should ever happen; if the thing is in scope
- -- at all it ought to have some availability
- | not (maybeToBool maybe_avail)
- = pprTrace "exportsFromAvail: curious Nothing:" (ppr name)
- returnRn acc
-#endif
+ -- See what's available in the current environment
+ case lookupUFM entity_avail_env name of {
+ Nothing -> -- I can't see why this should ever happen; if the thing
+ -- is in scope at all it ought to have some availability
+ pprTrace "exportsFromAvail: curious Nothing:" (ppr name)
+ returnRn acc ;
- | not enough_avail
- = failWithRn acc (exportItemErr ie)
+ Just avail ->
- | otherwise -- Phew! It's OK! Now to check the occurrence stuff!
+ -- Filter out the bits we want
+ case filterAvail ie avail of {
+ Nothing -> -- Not enough availability
+ failWithRn acc (exportItemErr ie) ;
+ Just export_avail ->
- = warnCheckRn (ok_item ie avail) (dodgyExportWarn ie) `thenRn_`
+ -- Phew! It's OK! Now to check the occurrence stuff!
+ warnCheckRn (ok_item ie avail) (dodgyExportWarn ie) `thenRn_`
check_occs ie occs export_avail `thenRn` \ occs' ->
returnRn (mods, occs', addAvail avails export_avail)
+ }}
+
- where
- rdr_name = ieName ie
- maybe_in_scope = lookupFM global_name_env rdr_name
- Just ((name,prov):dup_names) = maybe_in_scope
- maybe_avail = lookupUFM entity_avail_env name
- Just avail = maybe_avail
- maybe_export_avail = filterAvail ie avail
- enough_avail = maybeToBool maybe_export_avail
- Just export_avail = maybe_export_avail
-
- ok_item (IEThingAll _) (AvailTC _ [n]) = False
- -- This occurs when you import T(..), but
- -- only export T abstractly. The single [n]
- -- in the AvailTC is the type or class itself
- ok_item _ _ = True
+
+ok_item (IEThingAll _) (AvailTC _ [n]) = False
+ -- This occurs when you import T(..), but
+ -- only export T abstractly. The single [n]
+ -- in the AvailTC is the type or class itself
+ok_item _ _ = True
check_occs :: RdrNameIE -> ExportOccMap -> AvailInfo -> RnMG ExportOccMap
check_occs ie occs avail
%************************************************************************
\begin{code}
-badImportItemErr mod ie
- = sep [ptext SLIT("Module"), quotes (ppr mod),
+badImportItemErr mod from ie
+ = sep [ptext SLIT("Module"), quotes (ppr mod), source_import,
ptext SLIT("does not export"), quotes (ppr ie)]
+ where
+ source_import = case from of
+ ImportByUserSource -> ptext SLIT("(hi-boot interface)")
+ other -> empty
dodgyImportWarn mod item = dodgyMsg (ptext SLIT("import")) item
dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item