\begin{code}
module RnNames (
- rnImports, mkRdrEnvAndImports, importsFromLocalDecls,
- rnExports, mkExportNameSet,
+ rnImports, importsFromLocalDecls,
+ rnExports,
getLocalDeclBinders, extendRdrEnvRn,
reportUnusedNames, reportDeprecations
) where
import HsSyn ( IE(..), ieName, ImportDecl(..), LImportDecl,
ForeignDecl(..), HsGroup(..), HsValBinds(..),
Sig(..), collectHsBindLocatedBinders, tyClDeclNames,
+ instDeclATs, isIdxTyDecl,
LIE )
import RnEnv
+import RnHsDoc ( rnHsDoc )
import IfaceEnv ( ifaceExportNames )
import LoadIface ( loadSrcInterface )
import TcRnMonad hiding (LIE)
-import FiniteMap
import PrelNames
import Module
-import Name ( Name, nameSrcLoc, nameOccName, nameModule, isWiredInName,
- nameParent, nameParent_maybe, isExternalName,
- isBuiltInSyntax )
+import Name
import NameSet
import NameEnv
import OccName ( srcDataName, isTcOcc, pprNonVarNameSpace,
occNameSpace,
OccEnv, mkOccEnv, lookupOccEnv, emptyOccEnv,
extendOccEnv )
-import HscTypes ( GenAvailInfo(..), AvailInfo,
+import HscTypes ( GenAvailInfo(..), AvailInfo, availNames, availName,
HomePackageTable, PackageIfaceTable,
- mkPrintUnqualified,
+ mkPrintUnqualified, availsToNameSet,
+ availsToNameEnv,
Deprecs(..), ModIface(..), Dependencies(..),
lookupIfaceByModule, ExternalPackageState(..)
)
importSpecLoc, importSpecModule, isLocalGRE, pprNameProvenance )
import Outputable
import UniqFM
-import Maybes ( isNothing, catMaybes, mapCatMaybes, seqMaybe, orElse )
-import SrcLoc ( Located(..), mkGeneralSrcSpan,
+import Maybes
+import SrcLoc ( Located(..), mkGeneralSrcSpan, getLoc,
unLoc, noLoc, srcLocSpan, SrcSpan )
+import FiniteMap
+import ErrUtils
import BasicTypes ( DeprecTxt )
import DriverPhases ( isHsBoot )
import Util ( notNull )
-import List ( partition )
+import Data.List ( nub, partition, concatMap )
import IO ( openFile, IOMode(..) )
+import Monad ( when )
\end{code}
%************************************************************************
\begin{code}
-rnImports :: [LImportDecl RdrName] -> RnM [LImportDecl Name]
+rnImports :: [LImportDecl RdrName]
+ -> RnM ([LImportDecl Name], GlobalRdrEnv, ImportAvails)
+
rnImports imports
-- PROCESS IMPORT DECLS
-- Do the non {- SOURCE -} ones first, so that we get a helpful
let all_imports = mk_prel_imports this_mod implicit_prelude ++ imports
(source, ordinary) = partition is_source_import all_imports
is_source_import (L _ (ImportDecl _ is_boot _ _ _)) = is_boot
- get_imports = rnImportDecl this_mod
- stuff1 <- mapM get_imports ordinary
- stuff2 <- mapM get_imports source
- return (stuff1 ++ stuff2)
+ stuff1 <- mapM (rnImportDecl this_mod) ordinary
+ stuff2 <- mapM (rnImportDecl this_mod) source
+ let (decls, rdr_env, avails, imp_avails) = combine (stuff1 ++ stuff2)
+ return (decls, rdr_env,
+ imp_avails{ imp_parent = availsToNameEnv (nubAvails avails) })
+ -- why wait until now to set the imp_parent, rather than
+ -- setting it in rnImportDecl for each import, and
+ -- combining them with plusImportAvails? The reason is
+ -- that we need to combine all the AvailInfos *before*
+ -- we build the NameEnv, otherwise the NameEnv can
+ -- end up with inconsistencies, eg. the parent can say
+ -- C(m1,m2), but the entry for m2 might only say C(m2).
+ -- The test mod118 illustrates the bug.
where
-- NB: opt_NoImplicitPrelude is slightly different to import Prelude ();
-- because the former doesn't even look at Prelude.hi for instance
= notNull [ () | L _ (ImportDecl mod _ _ _ _) <- imports,
unLoc mod == pRELUDE_NAME ]
+ combine :: [(LImportDecl Name, GlobalRdrEnv, [AvailInfo], ImportAvails)]
+ -> ([LImportDecl Name], GlobalRdrEnv, [AvailInfo], ImportAvails)
+ combine = foldr plus ([], emptyGlobalRdrEnv, [], emptyImportAvails)
+ where plus (decl, gbl_env1, avails1, imp_avails1)
+ (decls, gbl_env2, avails2, imp_avails2)
+ = (decl:decls,
+ gbl_env1 `plusGlobalRdrEnv` gbl_env2,
+ avails1 ++ avails2,
+ imp_avails1 `plusImportAvails` imp_avails2)
+
preludeImportDecl :: LImportDecl RdrName
preludeImportDecl
= L loc $
where
loc = mkGeneralSrcSpan FSLIT("Implicit import declaration")
-mkRdrEnvAndImports :: [LImportDecl Name] -> RnM (GlobalRdrEnv, ImportAvails)
-mkRdrEnvAndImports imports
- = do this_mod <- getModule
- let get_imports = importsFromImportDecl this_mod
- stuff <- mapM get_imports imports
- let (imp_gbl_envs, imp_avails) = unzip stuff
- gbl_env :: GlobalRdrEnv
- gbl_env = foldr plusGlobalRdrEnv emptyGlobalRdrEnv imp_gbl_envs
-
- all_avails :: ImportAvails
- all_avails = foldr plusImportAvails emptyImportAvails imp_avails
- -- ALL DONE
- return (gbl_env, all_avails)
-
-\end{code}
-\begin{code}
-rnImportDecl :: Module
- -> LImportDecl RdrName
- -> RnM (LImportDecl Name)
-rnImportDecl this_mod (L loc importDecl@(ImportDecl loc_imp_mod_name want_boot qual_only as_mod imp_details))
- = setSrcSpan loc $
- do iface <- loadSrcInterface doc imp_mod_name want_boot
- let qual_mod_name = case as_mod of
- Nothing -> imp_mod_name
- Just another_name -> another_name
- imp_spec = ImpDeclSpec { is_mod = imp_mod_name, is_qual = qual_only,
- is_dloc = loc, is_as = qual_mod_name }
- total_avails <- ifaceExportNames (mi_exports iface)
- importDecl' <- rnImportDecl' iface imp_spec importDecl total_avails
- return (L loc importDecl')
- where imp_mod_name = unLoc loc_imp_mod_name
- doc = ppr imp_mod_name <+> ptext SLIT("is directly imported")
-
-rnImportDecl' :: ModIface -> ImpDeclSpec -> ImportDecl RdrName -> NameSet -> RnM (ImportDecl Name)
-rnImportDecl' iface decl_spec (ImportDecl mod_name want_boot qual_only as_mod Nothing) all_names
- = return $ ImportDecl mod_name want_boot qual_only as_mod Nothing
-rnImportDecl' iface decl_spec (ImportDecl mod_name want_boot qual_only as_mod (Just (want_hiding,import_items))) all_names
- = do import_items_mbs <- mapM (srcSpanWrapper) import_items
- let rn_import_items = concat . catMaybes $ import_items_mbs
- return $ ImportDecl mod_name want_boot qual_only as_mod (Just (want_hiding,rn_import_items))
- where
- srcSpanWrapper (L span ieRdr)
- = setSrcSpan span $
- case get_item ieRdr of
- Nothing
- -> do addErr (badImportItemErr iface decl_spec ieRdr)
- return Nothing
- Just ieNames
- -> return (Just [L span ie | ie <- ieNames])
- occ_env :: OccEnv Name -- Maps OccName to corresponding Name
- occ_env = mkOccEnv [(nameOccName n, n) | n <- nameSetToList all_names]
- -- This env will have entries for data constructors too,
- -- they won't make any difference because naked entities like T
- -- in an import list map to TcOccs, not VarOccs.
- sub_env :: NameEnv [Name]
- sub_env = mkSubNameEnv all_names
-
- get_item :: IE RdrName -> Maybe [IE Name]
- -- Empty result for a bad item.
- -- Singleton result is typical case.
- -- Can have two when we are hiding, and mention C which might be
- -- both a class and a data constructor.
- get_item item@(IEModuleContents _)
- = Nothing
- get_item (IEThingAll tc)
- = do name <- check_name tc
- return [IEThingAll name]
- get_item (IEThingAbs tc)
- | want_hiding -- hiding ( C )
- -- Here the 'C' can be a data constructor
- -- *or* a type/class, or even both
- = case catMaybes [check_name tc, check_name (setRdrNameSpace tc srcDataName)] of
- [] -> Nothing
- names -> return [ IEThingAbs n | n <- names ]
- | otherwise
- = do name <- check_name tc
- return [IEThingAbs name]
- get_item (IEThingWith n ns) -- import (C (A,B))
- = do name <- check_name n
- let env = mkOccEnv [(nameOccName s, s) | s <- subNames sub_env name]
- mb_names = map (lookupOccEnv env . rdrNameOcc) ns
- names <- sequence mb_names
- return [IEThingWith name names]
- get_item (IEVar n)
- = do name <- check_name n
- return [IEVar name]
-
- check_name :: RdrName -> Maybe Name
- check_name rdrName
- = lookupOccEnv occ_env (rdrNameOcc rdrName)
-
-
-importsFromImportDecl :: Module
- -> LImportDecl Name
- -> RnM (GlobalRdrEnv, ImportAvails)
-
-importsFromImportDecl this_mod
- (L loc (ImportDecl loc_imp_mod_name want_boot qual_only as_mod imp_details))
+rnImportDecl :: Module
+ -> LImportDecl RdrName
+ -> RnM (LImportDecl Name, GlobalRdrEnv,
+ [AvailInfo], ImportAvails)
+
+rnImportDecl this_mod (L loc (ImportDecl loc_imp_mod_name want_boot
+ qual_only as_mod imp_details))
=
- setSrcSpan loc $
+ setSrcSpan loc $ do
-- If there's an error in loadInterface, (e.g. interface
-- file not found) we get lots of spurious errors from 'filterImports'
let
imp_mod_name = unLoc loc_imp_mod_name
doc = ppr imp_mod_name <+> ptext SLIT("is directly imported")
- in
- loadSrcInterface doc imp_mod_name want_boot `thenM` \ iface ->
+
+ iface <- loadSrcInterface doc imp_mod_name want_boot
-- Compiler sanity check: if the import didn't say
-- {-# SOURCE #-} we should not get a hi-boot file
- WARN( not want_boot && mi_boot iface, ppr imp_mod_name )
+ WARN( not want_boot && mi_boot iface, ppr imp_mod_name ) (do
-- Issue a user warning for a redundant {- SOURCE -} import
-- NB that we arrange to read all the ordinary imports before
-- any of the {- SOURCE -} imports
warnIf (want_boot && not (mi_boot iface))
- (warnRedundantSourceImport imp_mod_name) `thenM_`
+ (warnRedundantSourceImport imp_mod_name)
let
imp_mod = mi_module iface
filtered_exports = filter not_this_mod (mi_exports iface)
not_this_mod (mod,_) = mod /= this_mod
- -- 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.)
+ -- 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
Just another_name -> another_name
imp_spec = ImpDeclSpec { is_mod = imp_mod_name, is_qual = qual_only,
is_dloc = loc, is_as = qual_mod_name }
- in
- -- Get the total imports, and filter them according to the import list
- ifaceExportNames filtered_exports `thenM` \ total_avails ->
- filterImports iface imp_spec
- imp_details total_avails `thenM` \ (avail_env, gbl_env) ->
+ -- in
+
+ -- Get the total exports from this module
+ total_avails <- ifaceExportNames filtered_exports
+
+ -- filter the imports according to the import declaration
+ (new_imp_details, filtered_avails, gbl_env) <-
+ filterImports iface imp_spec imp_details total_avails
- getDOpts `thenM` \ dflags ->
+ dflags <- getDOpts
let
-- Compute new transitive dependencies
Just (is_hiding, ls) -> not is_hiding && null ls
other -> False
- -- unqual_avails is the Avails that are visible in *unqualified* form
- -- We need to know this so we know what to export when we see
- -- module M ( module P ) where ...
- -- Then we must export whatever came from P unqualified.
imports = ImportAvails {
- imp_env = unitUFM qual_mod_name avail_env,
+ imp_env = unitUFM qual_mod_name filtered_avails,
imp_mods = unitModuleEnv imp_mod (imp_mod, import_all, loc),
imp_orphs = orphans,
imp_dep_mods = mkModDeps dependent_mods,
- imp_dep_pkgs = dependent_pkgs }
+ imp_dep_pkgs = dependent_pkgs,
+ imp_parent = emptyNameEnv
+ }
+
+ -- in
- in
-- Complain if we import a deprecated module
ifOptM Opt_WarnDeprecations (
case deprecs of
DeprecAll txt -> addWarn (moduleDeprec imp_mod_name txt)
other -> returnM ()
- ) `thenM_`
+ )
+
+ let new_imp_decl = L loc (ImportDecl loc_imp_mod_name want_boot
+ qual_only as_mod new_imp_details)
- returnM (gbl_env, imports)
+ returnM (new_imp_decl, gbl_env, filtered_avails, imports)
+ )
warnRedundantSourceImport mod_name
= ptext SLIT("Unnecessary {-# SOURCE #-} in the import of module")
importsFromLocalDecls group
= do { gbl_env <- getGblEnv
- ; names <- getLocalDeclBinders gbl_env group
+ ; avails <- getLocalDeclBinders gbl_env group
; implicit_prelude <- doptM Opt_ImplicitPrelude
; let {
-- Ditto in fixity decls; e.g. infix 5 :
-- Sigh. It doesn't matter because it only affects the Data.Tuple really.
-- The important thing is to trim down the exports.
- filtered_names
- | implicit_prelude = names
- | otherwise = filter (not . isBuiltInSyntax) names ;
+ names = concatMap availNames avails;
+
+ filtered_avails
+ | implicit_prelude = avails
+ | otherwise = filterAvails (not.isBuiltInSyntax) avails;
; this_mod = tcg_mod gbl_env
; imports = emptyImportAvails {
- imp_env = unitUFM (moduleName this_mod) $
- mkNameSet filtered_names
+ imp_env = unitUFM (moduleName this_mod)
+ filtered_avails,
+ imp_parent = availsToNameEnv avails
}
}
; rdr_env' <- extendRdrEnvRn (tcg_rdr_env gbl_env) names
+ ; traceRn (text "local avails: " <> ppr avails)
+
; returnM (gbl_env { tcg_rdr_env = rdr_env',
tcg_imports = imports `plusImportAvails` tcg_imports gbl_env })
}
*** See "THE NAMING STORY" in HsDecls ****
+Instances of indexed types
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+Indexed data/newtype instances contain data constructors that we need to
+collect, too. Moreover, we need to descend into the data/newtypes instances
+of associated families.
+
+We need to be careful with the handling of the type constructor of each type
+instance as the family constructor is already defined, and we want to avoid
+raising a duplicate declaration error. So, we make a new name for it, but
+don't return it in the 'AvailInfo'.
+
\begin{code}
-getLocalDeclBinders :: TcGblEnv -> HsGroup RdrName -> RnM [Name]
-getLocalDeclBinders gbl_env (HsGroup {hs_valds = ValBindsIn val_decls val_sigs,
+getLocalDeclBinders :: TcGblEnv -> HsGroup RdrName -> RnM [AvailInfo]
+getLocalDeclBinders gbl_env (HsGroup {hs_valds = ValBindsIn val_decls val_sigs,
hs_tyclds = tycl_decls,
+ hs_instds = inst_decls,
hs_fords = foreign_decls })
= do { tc_names_s <- mappM new_tc tycl_decls
+ ; at_names_s <- mappM inst_ats inst_decls
; val_names <- mappM new_simple val_bndrs
- ; return (foldr (++) val_names tc_names_s) }
+ ; return (val_names ++ tc_names_s ++ concat at_names_s) }
where
mod = tcg_mod gbl_env
is_hs_boot = isHsBoot (tcg_src gbl_env) ;
-- In a hs-boot file, the value binders come from the
-- *signatures*, and there should be no foreign binders
- new_simple rdr_name = newTopSrcBinder mod Nothing rdr_name
+ new_simple rdr_name = do
+ nm <- newTopSrcBinder mod rdr_name
+ return (Avail nm)
sig_hs_bndrs = [nm | L _ (TypeSig nm _) <- val_sigs]
val_hs_bndrs = collectHsBindLocatedBinders val_decls
for_hs_bndrs = [nm | L _ (ForeignImport nm _ _) <- foreign_decls]
new_tc tc_decl
- = do { main_name <- newTopSrcBinder mod Nothing main_rdr
- ; sub_names <- mappM (newTopSrcBinder mod (Just main_name)) sub_rdrs
- ; return (main_name : sub_names) }
- where
- (main_rdr : sub_rdrs) = tyClDeclNames (unLoc tc_decl)
+ | isIdxTyDecl (unLoc tc_decl)
+ = do { main_name <- lookupFamInstDeclBndr mod main_rdr
+ ; sub_names <- mappM (newTopSrcBinder mod) sub_rdrs
+ ; return (AvailTC main_name sub_names) }
+ -- main_name is not bound here!
+ | otherwise
+ = do { main_name <- newTopSrcBinder mod main_rdr
+ ; sub_names <- mappM (newTopSrcBinder mod) sub_rdrs
+ ; return (AvailTC main_name (main_name : sub_names)) }
+ where
+ (main_rdr : sub_rdrs) = tyClDeclNames (unLoc tc_decl)
+
+ inst_ats inst_decl
+ = mappM new_tc (instDeclATs (unLoc inst_decl))
\end{code}
\begin{code}
filterImports :: ModIface
-> ImpDeclSpec -- The span for the entire import decl
- -> Maybe (Bool, [LIE Name]) -- Import spec; True => hiding
- -> NameSet -- What's available
- -> RnM (NameSet, -- What's imported (qualified or unqualified)
+ -> Maybe (Bool, [LIE RdrName]) -- Import spec; True => hiding
+ -> [AvailInfo] -- What's available
+ -> RnM (Maybe (Bool, [LIE Name]), -- Import spec w/ Names
+ [AvailInfo], -- What's imported
GlobalRdrEnv) -- Same again, but in GRE form
-
- -- Complains if import spec mentions things that the module doesn't export
- -- Warns/informs if import spec contains duplicates.
-mkGenericRdrEnv decl_spec names
+filterImports iface decl_spec Nothing all_avails
+ = return (Nothing, all_avails, mkGenericRdrEnv decl_spec all_avails)
+
+filterImports iface decl_spec (Just (want_hiding, import_items)) all_avails
+ = do
+ -- check for errors, convert RdrNames to Names
+ opt_indexedtypes <- doptM Opt_IndexedTypes
+ items1 <- mapM (lookup_lie opt_indexedtypes) import_items
+
+ let -- build the AvailInfo corresponding to each import item.
+ items2 = [ (ie, filterAvailByIE (unLoc ie) av)
+ | (ie,av) <- concat items1 ]
+
+ -- eliminate duplicates
+ avails = nubAvails (map snd items2)
+
+ -- the new import spec, with Names instead of RdrNames
+ imp_spec_out = Just (want_hiding, map fst items2)
+
+ case want_hiding of
+ True ->
+ let
+ keep n = not (n `elemNameSet` availsToNameSet avails)
+ pruned_avails = filterAvails keep all_avails
+ in do
+ traceRn (text "pruned_avails: " <> ppr pruned_avails)
+ return (imp_spec_out, pruned_avails,
+ mkGenericRdrEnv decl_spec pruned_avails)
+
+ False ->
+ let
+ gres = concat [ mkGlobalRdrEltsFromIE decl_spec lie avail
+ | (lie, avail) <- items2 ]
+ in do
+ traceRn (text "imported avails: " <> ppr avails)
+ return (imp_spec_out, avails, mkGlobalRdrEnv gres)
+ where
+ -- This environment is how we map names mentioned in the import
+ -- list to the actual Name they correspond to, and the family
+ -- that the Name belongs to (an AvailInfo).
+ --
+ -- This env will have entries for data constructors too,
+ -- they won't make any difference because naked entities like T
+ -- in an import list map to TcOccs, not VarOccs.
+ occ_env :: OccEnv (Name,AvailInfo)
+ occ_env = mkOccEnv [ (nameOccName n, (n,a))
+ | a <- all_avails, n <- availNames a ]
+
+ lookup_lie :: Bool -> LIE RdrName -> TcRn [(LIE Name, AvailInfo)]
+ lookup_lie opt_indexedtypes (L loc ieRdr)
+ = do
+ stuff <- setSrcSpan loc $
+ case lookup_ie opt_indexedtypes ieRdr of
+ Failed err -> addErr err >> return []
+ Succeeded a -> return a
+ checkDodgyImport stuff
+ return [ (L loc ie, avail) | (ie,avail) <- stuff ]
+ where
+ -- warn when importing T(..) if T was exported absgtractly
+ checkDodgyImport stuff
+ | IEThingAll n <- ieRdr, (_, AvailTC _ [one]):_ <- stuff
+ = ifOptM Opt_WarnDodgyImports (addWarn (dodgyImportWarn n))
+ -- NB. use the RdrName for reporting the warning
+ checkDodgyImport _
+ = return ()
+
+ -- For each import item, we convert its RdrNames to Names,
+ -- and at the same time construct an AvailInfo corresponding
+ -- to what is actually imported by this item.
+ -- Returns Nothing on error.
+ -- We return a list here, because in the case of an import
+ -- item like C, if we are hiding, then C refers to *both* a
+ -- type/class and a data constructor.
+ lookup_ie :: Bool -> IE RdrName -> MaybeErr Message [(IE Name,AvailInfo)]
+ lookup_ie opt_indexedtypes ie
+ = let bad_ie = Failed (badImportItemErr iface decl_spec ie)
+
+ lookup_name rdrName =
+ case lookupOccEnv occ_env (rdrNameOcc rdrName) of
+ Nothing -> bad_ie
+ Just n -> return n
+ in
+ case ie of
+ IEVar n -> do
+ (name,avail) <- lookup_name n
+ return [(IEVar name, avail)]
+
+ IEThingAll tc -> do
+ (name,avail) <- lookup_name tc
+ return [(IEThingAll name, avail)]
+
+ IEThingAbs tc
+ | want_hiding -- hiding ( C )
+ -- Here the 'C' can be a data constructor
+ -- *or* a type/class, or even both
+ -> let tc_name = lookup_name tc
+ dc_name = lookup_name (setRdrNameSpace tc srcDataName)
+ in
+ case catMaybeErr [ tc_name, dc_name ] of
+ [] -> bad_ie
+ names -> return [ (IEThingAbs n, av) | (n,av) <- names ]
+ | otherwise
+ -> do (name,avail) <- lookup_name tc
+ return [(IEThingAbs name, avail)]
+
+ IEThingWith n ns -> do
+ (name,avail) <- lookup_name n
+ case avail of
+ AvailTC nm subnames | nm == name -> do
+ let env = mkOccEnv [ (nameOccName s, s)
+ | s <- subnames ]
+ let mb_children = map (lookupOccEnv env . rdrNameOcc) ns
+ children <-
+ if any isNothing mb_children
+ then bad_ie
+ else return (catMaybes mb_children)
+ -- check for proper import of indexed types
+ when (not opt_indexedtypes && any isTyConName children) $
+ Failed (typeItemErr (head . filter isTyConName
+ $ children )
+ (text "in import list"))
+ return [(IEThingWith name children, avail)]
+ _otherwise -> bad_ie
+
+ _other -> Failed illegalImportItemErr
+ -- could be IEModuleContents, IEGroup, IEDoc, IEDocNamed
+ -- all errors.
+
+catMaybeErr :: [MaybeErr err a] -> [a]
+catMaybeErr ms = [ a | Succeeded a <- ms ]
+\end{code}
+
+%************************************************************************
+%* *
+ Import/Export Utils
+%* *
+%************************************************************************
+
+\begin{code}
+-- | make a 'GlobalRdrEnv' where all the elements point to the same
+-- import declaration (useful for "hiding" imports, or imports with
+-- no details).
+mkGenericRdrEnv decl_spec avails
= mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = Imported [imp_spec] }
- | name <- nameSetToList names ]
+ | name <- concatMap availNames avails ]
where
imp_spec = ImpSpec { is_decl = decl_spec, is_item = ImpAll }
-filterImports iface decl_spec Nothing all_names
- = return (all_names, mkGenericRdrEnv decl_spec all_names)
-
-filterImports iface decl_spec (Just (want_hiding, import_items)) all_names
- = mapM (addLocM get_item) import_items >>= \gres_s ->
- let gres = concat gres_s
- specified_names = mkNameSet (map gre_name gres)
- in if not want_hiding then
- return (specified_names, mkGlobalRdrEnv gres)
- else let keep n = not (n `elemNameSet` specified_names)
- pruned_avails = filterNameSet keep all_names
- in return (pruned_avails, mkGenericRdrEnv decl_spec pruned_avails)
+
+-- | filters an 'AvailInfo' by the given import/export spec.
+filterAvailByIE :: IE Name -> AvailInfo -> AvailInfo
+filterAvailByIE (IEVar n) a@(Avail _) = a
+filterAvailByIE (IEVar n) a@(AvailTC tc subs) = AvailTC tc [n]
+filterAvailByIE (IEThingAbs n) a@(AvailTC _ _) = AvailTC n [n]
+filterAvailByIE (IEThingAll n) a@(AvailTC tc subs) = a
+filterAvailByIE (IEThingWith n ns) a@(AvailTC tc subs) =
+ AvailTC tc (filter (`elem` (n:ns)) subs)
+filterAvailByIE _ _ = panic "filterAvailByIE"
+
+-- | filters 'AvailInfo's by the given predicate
+filterAvails :: (Name -> Bool) -> [AvailInfo] -> [AvailInfo]
+filterAvails keep avails = foldr (filterAvail keep) [] avails
+
+-- | filters an 'AvailInfo' by the given predicate
+filterAvail :: (Name -> Bool) -> AvailInfo -> [AvailInfo] -> [AvailInfo]
+filterAvail keep ie rest =
+ case ie of
+ Avail n | keep n -> ie : rest
+ | otherwise -> rest
+ AvailTC tc ns ->
+ let left = filter keep ns in
+ if null left then rest else AvailTC tc left : rest
+
+-- | combines 'AvailInfo's from the same family
+nubAvails :: [AvailInfo] -> [AvailInfo]
+nubAvails avails = nameEnvElts (foldr add emptyNameEnv avails)
+ where
+ add avail env = extendNameEnv_C comb_avails env (availName avail) avail
+ comb_avails (AvailTC tc subs1) (AvailTC _ subs2)
+ = AvailTC tc (nub (subs1 ++ subs2))
+ comb_avails avail _ = avail
+
+-- | Given an import/export spec, construct the appropriate 'GlobalRdrElt's.
+mkGlobalRdrEltsFromIE :: ImpDeclSpec -> LIE Name -> AvailInfo -> [GlobalRdrElt]
+mkGlobalRdrEltsFromIE decl_spec (L loc ie) avail =
+ case ie of
+ IEVar name ->
+ [mk_explicit_gre name]
+ IEThingAbs name ->
+ [mk_explicit_gre name]
+ IEThingAll name | AvailTC _ subs <- avail ->
+ mk_explicit_gre name : map mk_implicit_gre subs
+ IEThingWith name subs ->
+ mk_explicit_gre name : map mk_explicit_gre subs
+ _ ->
+ panic "mkGlobalRdrEltsFromIE"
where
- sub_env :: NameEnv [Name] -- Classify each name by its parent
- sub_env = mkSubNameEnv all_names
+ mk_explicit_gre = mk_gre True
+ mk_implicit_gre = mk_gre False
- succeed_with :: Bool -> [Name] -> RnM [GlobalRdrElt]
- succeed_with all_explicit names
- = do { loc <- getSrcSpanM
- ; returnM (map (mk_gre loc) names) }
- where
- mk_gre loc name = GRE { gre_name = name,
- gre_prov = Imported [imp_spec] }
+ mk_gre explicit name = GRE { gre_name = name,
+ gre_prov = Imported [imp_spec] }
where
imp_spec = ImpSpec { is_decl = decl_spec, is_item = item_spec }
item_spec = ImpSome { is_explicit = explicit, is_iloc = loc }
- explicit = all_explicit || isNothing (nameParent_maybe name)
-
- get_item :: IE Name -> RnM [GlobalRdrElt]
- -- Empty result for a bad item.
- -- Singleton result is typical case.
- -- Can have two when we are hiding, and mention C which might be
- -- both a class and a data constructor.
- get_item item@(IEModuleContents _)
- -- This case should be filtered out by 'rnImports'.
- = panic "filterImports: IEModuleContents?"
-
- get_item (IEThingAll name)
- = case subNames sub_env name of
- [] -> -- This occurs when you import T(..), but
- -- only export T abstractly.
- do ifOptM Opt_WarnDodgyImports (addWarn (dodgyImportWarn name))
- succeed_with False [name]
- names -> succeed_with False (name:names)
-
- get_item (IEThingAbs name)
- = succeed_with True [name]
-
- get_item (IEThingWith name names)
- = succeed_with True (name:names)
- get_item (IEVar name)
- = succeed_with True [name]
-
\end{code}
\begin{code}
type ExportAccum -- The type of the accumulating parameter of
-- the main worker function in rnExports
- = ([ModuleName], -- 'module M's seen so far
+ = ([LIE Name], -- export items with Names
ExportOccMap, -- Tracks exported occurrence names
- NameSet) -- The accumulated exported stuff
-emptyExportAccum = ([], emptyOccEnv, emptyNameSet)
+ [AvailInfo]) -- The accumulated exported stuff
+emptyExportAccum = ([], emptyOccEnv, [])
type ExportOccMap = OccEnv (Name, IE RdrName)
-- Tracks what a particular exported OccName
-- it came from. It's illegal to export two distinct things
-- that have the same occurrence name
-rnExports :: Maybe [LIE RdrName]
- -> RnM (Maybe [LIE Name])
-rnExports Nothing = return Nothing
-rnExports (Just exports)
- = do TcGblEnv { tcg_imports = ImportAvails { imp_env = imp_env } } <- getGblEnv
- let sub_env :: NameEnv [Name] -- Classify each name by its parent
- sub_env = mkSubNameEnv (foldUFM unionNameSets emptyNameSet imp_env)
- rnExport (IEVar rdrName)
- = do name <- lookupGlobalOccRn rdrName
- return (IEVar name)
- rnExport (IEThingAbs rdrName)
- = do name <- lookupGlobalOccRn rdrName
- return (IEThingAbs name)
- rnExport (IEThingAll rdrName)
- = do name <- lookupGlobalOccRn rdrName
- return (IEThingAll name)
- rnExport ie@(IEThingWith rdrName rdrNames)
- = do name <- lookupGlobalOccRn rdrName
- if isUnboundName name
- then return (IEThingWith name [])
- else do
- let env = mkOccEnv [(nameOccName s, s) | s <- subNames sub_env name]
- mb_names = map (lookupOccEnv env . rdrNameOcc) rdrNames
- if any isNothing mb_names
- then do addErr (exportItemErr ie)
- return (IEThingWith name [])
- else return (IEThingWith name (catMaybes mb_names))
- rnExport (IEModuleContents mod)
- = return (IEModuleContents mod)
- rn_exports <- mapM (wrapLocM rnExport) exports
- return (Just rn_exports)
-
-mkExportNameSet :: Bool -- False => no 'module M(..) where' header at all
- -> Maybe ([LIE Name], [LIE RdrName]) -- Nothing => no explicit export list
- -> RnM NameSet
+rnExports :: Bool -- False => no 'module M(..) where' header at all
+ -> Maybe [LIE RdrName] -- Nothing => no explicit export list
+ -> RnM (Maybe [LIE Name], [AvailInfo])
+
-- Complains if two distinct exports have same OccName
-- Warns about identical exports.
-- Complains about exports items not in scope
-mkExportNameSet explicit_mod exports
- = do TcGblEnv { tcg_rdr_env = rdr_env,
+rnExports explicit_mod exports
+ = do TcGblEnv { tcg_mod = this_mod,
+ tcg_rdr_env = rdr_env,
tcg_imports = imports } <- getGblEnv
-- If the module header is omitted altogether, then behave
-- Reason: don't want to complain about 'main' not in scope
-- in interactive mode
ghc_mode <- getGhcMode
- real_exports <- case () of
- () | explicit_mod
- -> return exports
- | ghc_mode == Interactive
- -> return Nothing
- | otherwise
- -> do mainName <- lookupGlobalOccRn main_RDR_Unqual
- return (Just ([noLoc (IEVar mainName)]
- ,[noLoc (IEVar main_RDR_Unqual)]))
- -- ToDo: the 'noLoc' here is unhelpful if 'main' turns out to be out of scope
- exports_from_avail real_exports rdr_env imports
-
-
-exports_from_avail Nothing rdr_env imports
- = -- Export all locally-defined things
- -- We do this by filtering the global RdrEnv,
- -- keeping only things that are locally-defined
- return (mkNameSet [ gre_name gre
- | gre <- globalRdrEnvElts rdr_env,
- isLocalGRE gre ])
-
-exports_from_avail (Just (items,origItems)) rdr_env (ImportAvails { imp_env = imp_env })
- = do (_, _, exports) <- foldlM do_litem emptyExportAccum (zip items origItems)
- return exports
+ real_exports <-
+ case () of
+ () | explicit_mod
+ -> return exports
+ | ghc_mode == Interactive
+ -> return Nothing
+ | otherwise
+ -> do mainName <- lookupGlobalOccRn main_RDR_Unqual
+ return (Just ([noLoc (IEVar main_RDR_Unqual)]))
+ -- ToDo: the 'noLoc' here is unhelpful if 'main' turns
+ -- out to be out of scope
+
+ (exp_spec, avails) <- exports_from_avail real_exports rdr_env
+ imports this_mod
+ return (exp_spec, nubAvails avails)
+ -- combine families
+
+exports_from_avail :: Maybe [LIE RdrName]
+ -- Nothing => no explicit export list
+ -> GlobalRdrEnv
+ -> ImportAvails
+ -> Module
+ -> RnM (Maybe [LIE Name], [AvailInfo])
+
+exports_from_avail Nothing rdr_env imports this_mod
+ = -- the same as (module M) where M is the current module name,
+ -- so that's how we handle it.
+ let
+ names = [ gre_name gre | gre <- globalRdrEnvElts rdr_env,
+ isLocalGRE gre ]
+ avails = map (lookupNameEnv_NF (imp_parent imports)) names
+ in
+ return (Nothing, avails)
+
+exports_from_avail (Just rdr_items) rdr_env imports this_mod
+ = do traceRn (text "parent: " <> ppr (imp_parent imports))
+ (ie_names, _, exports) <- foldlM do_litem emptyExportAccum rdr_items
+ return (Just ie_names, exports)
where
- sub_env :: NameEnv [Name] -- Classify each name by its parent
- sub_env = mkSubNameEnv (foldUFM unionNameSets emptyNameSet imp_env)
-
- do_litem :: ExportAccum -> (LIE Name, LIE RdrName) -> RnM ExportAccum
- do_litem acc (ieName, ieRdr)
- = addLocM (exports_from_item acc (unLoc ieRdr)) ieName
+ do_litem :: ExportAccum -> LIE RdrName -> RnM ExportAccum
+ do_litem acc lie = setSrcSpan (getLoc lie) (exports_from_item acc lie)
- exports_from_item :: ExportAccum -> IE RdrName -> IE Name -> RnM ExportAccum
- exports_from_item acc@(mods, occs, exports) ieRdr@(IEModuleContents mod) ie
+ exports_from_item :: ExportAccum -> LIE RdrName -> RnM ExportAccum
+ exports_from_item acc@(ie_names, occs, exports)
+ (L loc ie@(IEModuleContents mod))
| mod `elem` mods -- Duplicate export of M
= do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ;
warnIf warn_dup_exports (dupModuleExport mod) ;
returnM acc }
| otherwise
- = case lookupUFM imp_env mod of
+ = case lookupUFM (imp_env imports) mod of
Nothing -> do addErr (modExportErr mod)
return acc
- Just names
- -> do let new_exports = filterNameSet (inScopeUnqual rdr_env) names
- -- This check_occs not only finds conflicts between this item
- -- and others, but also internally within this item. That is,
- -- if 'M.x' is in scope in several ways, we'll have several
- -- members of mod_avails with the same OccName.
- occs' <- check_occs ieRdr occs (nameSetToList new_exports)
- return (mod:mods, occs', exports `unionNameSets` new_exports)
-
- exports_from_item acc@(mods, occs, exports) ieRdr ie
- = if isUnboundName (ieName ie)
- then return acc -- Avoid error cascade
- else let new_exports = filterAvail ie sub_env in
- do -- checkErr (not (null (drop 1 new_exports))) (exportItemErr ie)
- checkForDodgyExport ie new_exports
- occs' <- check_occs ieRdr occs new_exports
- return (mods, occs', addListToNameSet exports new_exports)
+ Just avails
+ -> do traceRn (text "mod avails: " <> ppr mod <+> ppr avails)
+ let avails' = filterAvails (inScopeUnqual rdr_env) $
+ nubAvails avails
+ new_exps = concatMap availNames avails'
+
+ occs' <- check_occs ie occs new_exps
+ -- This check_occs not only finds conflicts
+ -- between this item and others, but also
+ -- internally within this item. That is, if
+ -- 'M.x' is in scope in several ways, we'll have
+ -- several members of mod_avails with the same
+ -- OccName.
+ return (L loc (IEModuleContents mod) : ie_names,
+ occs', avails' ++ exports)
+ where
+ mods = [ mod | (L _ (IEModuleContents mod)) <- ie_names ]
+
+ exports_from_item acc@(lie_names, occs, exports) (L loc ie)
+ = do new_ie <- lookup_ie ie
+ let ie_name = ieName new_ie
+ if isUnboundName ie_name
+ then return acc -- Avoid error cascade
+ else do
+ if isDoc new_ie -- deal with docs
+ then return (L loc new_ie : lie_names, occs, exports)
+ else do
+ traceRn (text "lookup_avail: " <> ppr (lookup_avail ie_name))
+ let avail = filterAvailByIE new_ie (lookup_avail ie_name)
+ new_exports = case new_ie of
+ IEThingWith n ns -> n : ns
+ _ -> availNames avail
+ -- ^^^ an IEThingWith might contain duplicates
+ -- whereas the avail doesn't, but we want
+ -- duplicates to be noticed by check_occs below.
+ -- checkErr (not (null (drop 1 new_exports))) (exportItemErr ie)
+ checkForDodgyExport new_ie new_exports
+ occs' <- check_occs ie occs new_exports
+ return (L loc new_ie : lie_names, occs', avail : exports)
--------------------------------
-filterAvail :: IE Name -- Wanted
- -> NameEnv [Name] -- Maps type/class names to their sub-names
- -> [Name]
-
-filterAvail (IEVar n) subs = [n]
-filterAvail (IEThingAbs n) subs = [n]
-filterAvail (IEThingAll n) subs = n : subNames subs n
-filterAvail (IEThingWith n ns) subs = n : ns
-filterAvail (IEModuleContents _) _ = panic "filterAvail"
-
-subNames :: NameEnv [Name] -> Name -> [Name]
-subNames env n = lookupNameEnv env n `orElse` []
-
-mkSubNameEnv :: NameSet -> NameEnv [Name]
--- Maps types and classes to their constructors/classops respectively
--- This mapping just makes it easier to deal with A(..) export items
-mkSubNameEnv names
- = foldNameSet add_name emptyNameEnv names
- where
- add_name name env
- | Just parent <- nameParent_maybe name
- = extendNameEnv_C (\ns _ -> name:ns) env parent [name]
- | otherwise = env
+ lookup_avail :: Name -> AvailInfo
+ lookup_avail name =
+ case lookupNameEnv avail_env name of
+ Nothing -> pprPanic "rnExports:lookup_avail" (ppr name)
+ Just a -> a
+ where avail_env = imp_parent imports
+
+ lookup_ie :: IE RdrName -> RnM (IE Name)
+
+ lookup_ie (IEVar rdr)
+ = do name <- lookupGlobalOccRn rdr
+ return (IEVar name)
+
+ lookup_ie (IEThingAbs rdr)
+ = do name <- lookupGlobalOccRn rdr
+ return (IEThingAbs name)
+
+ lookup_ie (IEThingAll rdr)
+ = do name <- lookupGlobalOccRn rdr
+ return (IEThingAll name)
+
+ lookup_ie ie@(IEThingWith rdr sub_rdrs)
+ = do name <- lookupGlobalOccRn rdr
+ if isUnboundName name
+ then return (IEThingWith name [])
+ else do
+ let avail = lookup_avail name
+ env = mkOccEnv [ (nameOccName s, s)
+ | AvailTC _ subnames <- [avail],
+ s <- subnames ]
+ let mb_names = map (lookupOccEnv env . rdrNameOcc) sub_rdrs
+ if any isNothing mb_names
+ then do addErr (exportItemErr ie)
+ return (IEThingWith name [])
+ else do let names = catMaybes mb_names
+ optIdxTypes <- doptM Opt_IndexedTypes
+ when (not optIdxTypes && any isTyConName names) $
+ addErr (typeItemErr ( head
+ . filter isTyConName
+ $ names )
+ (text "in export list"))
+ return (IEThingWith name (catMaybes mb_names))
+
+ lookup_ie (IEGroup lev doc)
+ = do rn_doc <- rnHsDoc doc
+ return (IEGroup lev rn_doc)
+ lookup_ie (IEDoc doc)
+ = do rn_doc <- rnHsDoc doc
+ return (IEDoc rn_doc)
+ lookup_ie (IEDocNamed str)
+ = return (IEDocNamed str)
+
+ lookup_ie (IEModuleContents _)
+ = panic "rnExports:lookup_ie" -- caught earlier
+
+
+isDoc (IEDoc _) = True
+isDoc (IEDocNamed _) = True
+isDoc (IEGroup _ _) = True
+isDoc _ = False
-------------------------------
inScopeUnqual :: GlobalRdrEnv -> Name -> Bool
| otherwise -- Same occ name but different names: an error
-> do { global_env <- getGlobalRdrEnv ;
- addErr (exportClashErr global_env name name' ie ie') ;
+ addErr (exportClashErr global_env name' name ie' ie) ;
returnM occs }
where
name_occ = nameOccName name
-- Report on all deprecated uses; hence allUses
all_gres = globalRdrEnvElts (tcg_rdr_env tcg_env)
+ avail_env = imp_parent (tcg_imports tcg_env)
+
check hpt pit (GRE {gre_name = name, gre_prov = Imported (imp_spec:_)})
| name `elemNameSet` used_names
- , Just deprec_txt <- lookupDeprec dflags hpt pit name
- = setSrcSpan (importSpecLoc imp_spec) $
- addWarn (sep [ptext SLIT("Deprecated use of") <+>
+ , Just deprec_txt <- lookupDeprec dflags hpt pit avail_env name
+ = addWarnAt (importSpecLoc imp_spec)
+ (sep [ptext SLIT("Deprecated use of") <+>
pprNonVarNameSpace (occNameSpace (nameOccName name)) <+>
quotes (ppr name),
(parens imp_msg) <> colon,
-- interface
lookupDeprec :: DynFlags -> HomePackageTable -> PackageIfaceTable
+ -> NameEnv AvailInfo -- parent info
-> Name -> Maybe DeprecTxt
-lookupDeprec dflags hpt pit n
+lookupDeprec dflags hpt pit avail_env n
= case lookupIfaceByModule dflags hpt pit (nameModule n) of
Just iface -> mi_dep_fn iface n `seqMaybe` -- Bleat if the thing, *or
mi_dep_fn iface (nameParent n) -- its parent*, is deprec'd
| otherwise -> pprPanic "lookupDeprec" (ppr n)
-- By now all the interfaces should have been loaded
+ where
+ nameParent n = case lookupNameEnv avail_env n of
+ Just (AvailTC parent _) -> parent
+ _ -> n
gre_is_used :: NameSet -> GlobalRdrElt -> Bool
gre_is_used used_names gre = gre_name gre `elemNameSet` used_names
-- NB: currently, if f x = g, we only treat 'g' as used if 'f' is used
-- Hence findUses
+ avail_env = imp_parent (tcg_imports gbl_env)
+ nameParent_maybe n = case lookupNameEnv avail_env n of
+ Just (AvailTC tc _) | tc /= n -> Just tc
+ _otherwise -> Nothing
+
all_used_names = used_names `unionNameSets`
mkNameSet (mapCatMaybes nameParent_maybe (nameSetToList used_names))
-- A use of C implies a use of T,
source_import | mi_boot iface = ptext SLIT("(hi-boot interface)")
| otherwise = empty
+illegalImportItemErr = ptext SLIT("Illegal import item")
+
dodgyImportWarn item = dodgyMsg (ptext SLIT("import")) item
dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item
= sep [ ptext SLIT("The export item") <+> quotes (ppr export_item),
ptext SLIT("attempts to export constructors or class methods that are not visible here") ]
+typeItemErr name wherestr
+ = sep [ ptext SLIT("Using 'type' tag on") <+> quotes (ppr name) <+> wherestr,
+ ptext SLIT("Use -findexed-types to enable this extension") ]
+
exportClashErr global_env name1 name2 ie1 ie2
= vcat [ ptext SLIT("Conflicting exports for") <+> quotes (ppr occ) <> colon
, ppr_export ie1 name1