\begin{code}
module RnNames (
- rnImports, importsFromLocalDecls,
- reportUnusedNames, reportDeprecations,
- mkModDeps, exportsToAvails, exportsFromAvail
+ rnImports, mkRdrEnvAndImports, importsFromLocalDecls,
+ rnExports, mkExportNameSet,
+ getLocalDeclBinders, extendRdrEnvRn,
+ reportUnusedNames, reportDeprecations
) where
#include "HsVersions.h"
-import CmdLineOpts ( DynFlag(..) )
+import DynFlags ( DynFlag(..), GhcMode(..) )
import HsSyn ( IE(..), ieName, ImportDecl(..), LImportDecl,
- ForeignDecl(..), HsGroup(..), HsBindGroup(..),
- Sig(..), collectGroupBinders, tyClDeclNames
- )
+ ForeignDecl(..), HsGroup(..), HsValBinds(..),
+ Sig(..), collectHsBindLocatedBinders, tyClDeclNames,
+ LIE )
import RnEnv
-import IfaceEnv ( lookupOrig, newGlobalBinder )
+import IfaceEnv ( ifaceExportNames )
import LoadIface ( loadSrcInterface )
-import TcRnMonad
+import TcRnMonad hiding (LIE)
import FiniteMap
import PrelNames ( pRELUDE, isUnboundName, main_RDR_Unqual )
-import Module ( Module, moduleUserString,
- unitModuleEnv, unitModuleEnv,
+import Module ( Module, moduleString, unitModuleEnv,
lookupModuleEnv, moduleEnvElts, foldModuleEnv )
import Name ( Name, nameSrcLoc, nameOccName, nameModule, isWiredInName,
nameParent, nameParent_maybe, isExternalName,
isBuiltInSyntax )
import NameSet
import NameEnv
-import OccName ( srcDataName, isTcOcc, occNameFlavour, OccEnv,
- mkOccEnv, lookupOccEnv, emptyOccEnv, extendOccEnv )
-import HscTypes ( GenAvailInfo(..), AvailInfo, GhciMode(..),
- IfaceExport, HomePackageTable, PackageIfaceTable,
- availNames, unQualInScope,
+import OccName ( srcDataName, isTcOcc, pprNonVarNameSpace,
+ occNameSpace,
+ OccEnv, mkOccEnv, lookupOccEnv, emptyOccEnv,
+ extendOccEnv )
+import HscTypes ( GenAvailInfo(..), AvailInfo,
+ HomePackageTable, PackageIfaceTable,
+ unQualInScope,
Deprecs(..), ModIface(..), Dependencies(..),
lookupIface, ExternalPackageState(..)
)
import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace,
GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..),
emptyGlobalRdrEnv, plusGlobalRdrEnv, globalRdrEnvElts,
- unQualOK, lookupGRE_Name,
- Provenance(..), ImportSpec(..),
- isLocalGRE, pprNameProvenance )
+ extendGlobalRdrEnv, lookupGlobalRdrEnv, unQualOK, lookupGRE_Name,
+ Provenance(..), ImportSpec(..), ImpDeclSpec(..), ImpItemSpec(..),
+ importSpecLoc, importSpecModule, isLocalGRE, pprNameProvenance )
import Outputable
import Maybes ( isNothing, catMaybes, mapCatMaybes, seqMaybe, orElse )
-import SrcLoc ( noSrcLoc, Located(..), mkGeneralSrcSpan,
- unLoc, noLoc, srcLocSpan, combineSrcSpans, SrcSpan )
+import SrcLoc ( Located(..), mkGeneralSrcSpan,
+ unLoc, noLoc, srcLocSpan, SrcSpan )
import BasicTypes ( DeprecTxt )
-import ListSetOps ( removeDups )
-import Util ( sortLe, notNull, isSingleton )
+import DriverPhases ( isHsBoot )
+import Util ( notNull )
import List ( partition )
import IO ( openFile, IOMode(..) )
\end{code}
%************************************************************************
\begin{code}
-rnImports :: [LImportDecl RdrName]
- -> RnM (GlobalRdrEnv, ImportAvails)
-
+rnImports :: [LImportDecl RdrName] -> RnM [LImportDecl Name]
rnImports imports
- = do { -- PROCESS IMPORT DECLS
- -- Do the non {- SOURCE -} ones first, so that we get a helpful
- -- warning for {- SOURCE -} ones that are unnecessary
- this_mod <- getModule
- ; implicit_prelude <- doptM Opt_ImplicitPrelude
- ; 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 = importsFromImportDecl this_mod
-
- ; stuff1 <- mappM get_imports ordinary
- ; stuff2 <- mappM get_imports source
-
- -- COMBINE RESULTS
- ; let
- (imp_gbl_envs, imp_avails) = unzip (stuff1 ++ stuff2)
- 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) }
- where
- -- NB: opt_NoImplicitPrelude is slightly different to import Prelude ();
- -- because the former doesn't even look at Prelude.hi for instance
- -- declarations, whereas the latter does.
- mk_prel_imports this_mod implicit_prelude
- | this_mod == pRELUDE
- || explicit_prelude_import
- || not implicit_prelude
- = []
-
- | otherwise = [preludeImportDecl]
-
- explicit_prelude_import
- = notNull [ () | L _ (ImportDecl mod _ _ _ _) <- imports,
- unLoc mod == pRELUDE ]
-
+ -- PROCESS IMPORT DECLS
+ -- Do the non {- SOURCE -} ones first, so that we get a helpful
+ -- warning for {- SOURCE -} ones that are unnecessary
+ = do this_mod <- getModule
+ implicit_prelude <- doptM Opt_ImplicitPrelude
+ 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 = importsFromImportDeclDirect this_mod
+
+ stuff1 <- mapM get_imports ordinary
+ stuff2 <- mapM get_imports source
+ return (stuff1 ++ stuff2)
+ where
+-- NB: opt_NoImplicitPrelude is slightly different to import Prelude ();
+-- because the former doesn't even look at Prelude.hi for instance
+-- declarations, whereas the latter does.
+ mk_prel_imports this_mod implicit_prelude
+ | this_mod == pRELUDE
+ || explicit_prelude_import
+ || not implicit_prelude
+ = []
+ | otherwise = [preludeImportDecl]
+ explicit_prelude_import
+ = notNull [ () | L _ (ImportDecl mod _ _ _ _) <- imports,
+ unLoc mod == pRELUDE ]
+
+preludeImportDecl :: LImportDecl RdrName
preludeImportDecl
= L loc $
ImportDecl (L loc pRELUDE)
Nothing {- No "as" -}
Nothing {- No import list -}
where
- loc = mkGeneralSrcSpan FSLIT("Implicit import declaration")
+ 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 :: ModIface -> ImpDeclSpec -> ImportDecl RdrName -> NameSet -> RnM (ImportDecl Name)
+rnImportDecl iface decl_spec (ImportDecl loc_imp_mod_name want_boot qual_only as_mod Nothing) all_names
+ = return $ ImportDecl loc_imp_mod_name want_boot qual_only as_mod Nothing
+rnImportDecl iface decl_spec (ImportDecl loc_imp_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 loc_imp_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]
+{-
+ -> -- This occurs when you import T(..), but
+ -- only export T abstractly. The single [n]
+ -- in the AvailTC is the type or class itself
+ ifOptM Opt_WarnDodgyImports (addWarn (dodgyImportWarn tc)) `thenM_`
+ return [ IEThingAll n ]
+
+ names -> return [ IEThingAll n | n <- names ]
+-}
+
+ 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)
+
+
+importsFromImportDeclDirect :: Module
+ -> LImportDecl RdrName
+ -> RnM (LImportDecl Name)
+importsFromImportDeclDirect 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 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.)
+ --
+ -- 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.
+
+ 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 }
+
+ -- Get the total imports, and filter them according to the import list
+ 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")
+
importsFromImportDecl :: Module
- -> LImportDecl RdrName
+ -> LImportDecl Name
-> RnM (GlobalRdrEnv, ImportAvails)
importsFromImportDecl this_mod
qual_mod_name = case as_mod of
Nothing -> imp_mod_name
Just another_name -> another_name
- imp_spec = ImportSpec { is_mod = imp_mod_name, is_qual = qual_only,
- is_loc = loc, is_as = qual_mod_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
- exportsToAvails filtered_exports `thenM` \ total_avails ->
+ ifaceExportNames filtered_exports `thenM` \ total_avails ->
filterImports iface imp_spec
imp_details total_avails `thenM` \ (avail_env, gbl_env) ->
ASSERT2( not (pkg `elem` dep_pkgs deps), ppr pkg <+> ppr (dep_pkgs deps) )
([], pkg : dep_pkgs deps)
+ -- True <=> import M ()
import_all = case imp_details of
- Just (is_hiding, ls) -- Imports are spec'd explicitly
- | not is_hiding -> Just (not (null ls))
- _ -> Nothing -- Everything is imported,
- -- (or almost everything [hiding])
+ 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
returnM (gbl_env, imports)
-exportsToAvails :: [IfaceExport] -> TcRnIf gbl lcl NameSet
-exportsToAvails exports
- = foldlM do_one emptyNameSet exports
- where
- do_one acc (mod, exports) = foldlM (do_avail mod) acc exports
- do_avail mod acc (Avail n) = do { n' <- lookupOrig mod n;
- ; return (addOneToNameSet acc n') }
- do_avail mod acc (AvailTC p_occ occs)
- = do { p_name <- lookupOrig mod p_occ
- ; ns <- mappM (lookup_sub p_name) occs
- ; return (addListToNameSet acc ns) }
- -- Remember that 'occs' is all the exported things, including
- -- the parent. It's possible to export just class ops without
- -- the class, via C( op ). If the class was exported too we'd
- -- have C( C, op )
- where
- lookup_sub parent occ
- = newGlobalBinder mod occ mb_parent noSrcLoc
- where
- mb_parent | occ == p_occ = Nothing
- | otherwise = Just parent
-
- -- The use of newGlobalBinder here (rather than lookupOrig)
- -- ensures that the subordinate names record their parent;
- -- and that in turn ensures that the GlobalRdrEnv
- -- has the correct parent for all the names in its range.
- -- For imported things, we only suck in the binding site later, if ever.
- -- Reason for all this:
- -- Suppose module M exports type A.T, and constructor A.MkT
- -- Then, we know that A.MkT is a subordinate name of A.T,
- -- even though we aren't at the binding site of A.T
- -- And it's important, because we may simply re-export A.T
- -- without ever sucking in the declaration itself.
-
warnRedundantSourceImport mod_name
= ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
<+> quotes (ppr mod_name)
Complain about duplicate bindings
\begin{code}
-importsFromLocalDecls :: HsGroup RdrName
- -> RnM (GlobalRdrEnv, ImportAvails)
+importsFromLocalDecls :: HsGroup RdrName -> RnM TcGblEnv
importsFromLocalDecls group
- = getModule `thenM` \ this_mod ->
- getLocalDeclBinders this_mod group `thenM` \ avails ->
- -- The avails that are returned don't include the "system" names
- let
- all_names :: [Name] -- All the defns; no dups eliminated
- all_names = [name | avail <- avails, name <- availNames avail]
+ = do { gbl_env <- getGblEnv
- dups :: [[Name]]
- (_, dups) = removeDups compare all_names
- in
- -- Check for duplicate definitions
- -- The complaint will come out as "Multiple declarations of Foo.f" because
- -- since 'f' is in the env twice, the unQualInScope used by the error-msg
- -- printer returns False. It seems awkward to fix, unfortunately.
- mappM_ addDupDeclErr dups `thenM_`
-
- doptM Opt_ImplicitPrelude `thenM` \ implicit_prelude ->
- let
- prov = LocalDef this_mod
- gbl_env = mkGlobalRdrEnv gres
- gres = [ GRE { gre_name = name, gre_prov = prov}
- | name <- all_names]
+ ; names <- getLocalDeclBinders gbl_env group
+ ; implicit_prelude <- doptM Opt_ImplicitPrelude
+ ; let {
-- Optimisation: filter out names for built-in syntax
-- They just clutter up the environment (esp tuples), and the parser
-- will generate Exact RdrNames for them, so the cluttered
-- 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 = all_names
- | otherwise = filter (not . isBuiltInSyntax) all_names
-
- imports = emptyImportAvails {
- imp_env = unitModuleEnv this_mod $
- mkNameSet filtered_names
- }
- in
- returnM (gbl_env, imports)
+ filtered_names
+ | implicit_prelude = names
+ | otherwise = filter (not . isBuiltInSyntax) names ;
+
+ ; this_mod = tcg_mod gbl_env
+ ; imports = emptyImportAvails {
+ imp_env = unitModuleEnv this_mod $
+ mkNameSet filtered_names
+ }
+ }
+
+ ; rdr_env' <- extendRdrEnvRn (tcg_rdr_env gbl_env) names
+
+ ; returnM (gbl_env { tcg_rdr_env = rdr_env',
+ tcg_imports = imports `plusImportAvails` tcg_imports gbl_env })
+ }
+
+extendRdrEnvRn :: GlobalRdrEnv -> [Name] -> RnM GlobalRdrEnv
+-- Add the new locally-bound names one by one, checking for duplicates as
+-- we do so. Remember that in Template Haskell the duplicates
+-- might *already be* in the GlobalRdrEnv from higher up the module
+extendRdrEnvRn rdr_env names
+ = foldlM add_local rdr_env names
+ where
+ add_local rdr_env name
+ | gres <- lookupGlobalRdrEnv rdr_env (nameOccName name)
+ , (dup_gre:_) <- filter isLocalGRE gres -- Check for existing *local* defns
+ = do { addDupDeclErr (gre_name dup_gre) name
+ ; return rdr_env }
+ | otherwise
+ = return (extendGlobalRdrEnv rdr_env new_gre)
+ where
+ new_gre = GRE {gre_name = name, gre_prov = LocalDef}
\end{code}
-
-%*********************************************************
-%* *
-\subsection{Getting binders out of a declaration}
-%* *
-%*********************************************************
-
@getLocalDeclBinders@ returns the names for an @HsDecl@. It's
used for source code.
*** See "THE NAMING STORY" in HsDecls ****
\begin{code}
-getLocalDeclBinders :: Module -> HsGroup RdrName -> RnM [AvailInfo]
-getLocalDeclBinders mod (HsGroup {hs_valds = val_decls,
- hs_tyclds = tycl_decls,
- hs_fords = foreign_decls })
- = -- For type and class decls, we generate Global names, with
- -- no export indicator. They need to be global because they get
- -- permanently bound into the TyCons and Classes. They don't need
- -- an export indicator because they are all implicitly exported.
-
- mappM new_tc tycl_decls `thenM` \ tc_avails ->
-
+getLocalDeclBinders :: TcGblEnv -> HsGroup RdrName -> RnM [Name]
+getLocalDeclBinders gbl_env (HsGroup {hs_valds = ValBindsIn val_decls val_sigs,
+ hs_tyclds = tycl_decls,
+ hs_fords = foreign_decls })
+ = do { tc_names_s <- mappM new_tc tycl_decls
+ ; val_names <- mappM new_simple val_bndrs
+ ; return (foldr (++) val_names tc_names_s) }
+ where
+ mod = tcg_mod gbl_env
+ is_hs_boot = isHsBoot (tcg_src gbl_env) ;
+ val_bndrs | is_hs_boot = sig_hs_bndrs
+ | otherwise = for_hs_bndrs ++ val_hs_bndrs
-- In a hs-boot file, the value binders come from the
- -- *signatures*, and there should be no foreign binders
- tcIsHsBoot `thenM` \ is_hs_boot ->
- let val_bndrs | is_hs_boot = sig_hs_bndrs
- | otherwise = for_hs_bndrs ++ val_hs_bndrs
- in
- mappM new_simple val_bndrs `thenM` \ names ->
+ -- *signatures*, and there should be no foreign binders
- returnM (tc_avails ++ map Avail names)
- where
new_simple rdr_name = newTopSrcBinder mod Nothing rdr_name
- sig_hs_bndrs = [nm | HsBindGroup _ lsigs _ <- val_decls,
- L _ (Sig nm _) <- lsigs]
- val_hs_bndrs = collectGroupBinders val_decls
+ 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
- = newTopSrcBinder mod Nothing main_rdr `thenM` \ main_name ->
- mappM (newTopSrcBinder mod (Just main_name)) sub_rdrs `thenM` \ sub_names ->
- returnM (AvailTC main_name (main_name : sub_names))
+ = 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)
\end{code}
\begin{code}
filterImports :: ModIface
- -> ImportSpec -- The span for the entire import decl
- -> Maybe (Bool, [Located (IE RdrName)]) -- Import spec; True => hiding
+ -> 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)
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 imp_spec names
- = mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = Imported [imp_spec] False }
+mkGenericRdrEnv decl_spec names
+ = mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = Imported [imp_spec] }
| name <- nameSetToList names ]
-
-filterImports iface imp_spec Nothing all_names
- = returnM (all_names, mkGenericRdrEnv imp_spec all_names)
-
-filterImports iface imp_spec (Just (want_hiding, import_items)) all_names
- = mappM (addLocM get_item) import_items `thenM` \ 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 imp_spec pruned_avails)
-
where
- 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]
+ 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)
+ where
+ sub_env :: NameEnv [Name] -- Classify each name by its parent
sub_env = mkSubNameEnv all_names
- bale_out item = addErr (badImportItemErr iface imp_spec item) `thenM_`
- returnM []
-
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 [this_imp_spec loc] (explicit name) }
- this_imp_spec loc = imp_spec { is_loc = loc }
- explicit name = all_explicit || isNothing (nameParent_maybe 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 RdrName -> RnM [GlobalRdrElt]
+ 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 _)
- = bale_out item
+ -- This case should be filtered out by 'rnImports'.
+ = panic "filterImports: IEModuleContents?"
- get_item item@(IEThingAll tc)
- = case check_item item of
- [] -> bale_out item
+ get_item (IEThingAll name)
+ = case subNames sub_env name of
+ [] -> do ifOptM Opt_WarnDodgyImports (addWarn (dodgyImportWarn name))
+ succeed_with False [name]
+ names -> succeed_with False (name:names)
- [n] -> -- This occurs when you import T(..), but
- -- only export T abstractly. The single [n]
- -- in the AvailTC is the type or class itself
- ifOptM Opt_WarnDodgyImports (addWarn (dodgyImportWarn tc)) `thenM_`
- succeed_with False [n]
+ get_item (IEThingAbs name)
+ = succeed_with True [name]
- names -> succeed_with False names
+ get_item (IEThingWith name names)
+ = succeed_with True (name:names)
+ get_item (IEVar name)
+ = succeed_with True [name]
- get_item item@(IEThingAbs n)
- | want_hiding -- hiding( C )
- -- Here the 'C' can be a data constructor
- -- *or* a type/class, or even both
- = case concat [check_item item, check_item (IEVar data_n)] of
- [] -> bale_out item
- names -> succeed_with True names
- where
- data_n = setRdrNameSpace n srcDataName
-
- get_item item
- = case check_item item of
- [] -> bale_out item
- names -> succeed_with True names
-
- check_item :: IE RdrName -> [Name]
- check_item item
- = case lookupOccEnv occ_env (rdrNameOcc (ieName item)) of
- Nothing -> []
- Just name -> filterAvail item name sub_env
\end{code}
\begin{code}
type ExportAccum -- The type of the accumulating parameter of
- -- the main worker function in exportsFromAvail
+ -- the main worker function in rnExports
= ([Module], -- 'module M's seen so far
ExportOccMap, -- Tracks exported occurrence names
NameSet) -- The accumulated exported stuff
emptyExportAccum = ([], emptyOccEnv, emptyNameSet)
-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
-- that have the same occurrence name
-
-exportsFromAvail :: Bool -- False => no 'module M(..) where' header at all
- -> Maybe [Located (IE RdrName)] -- Nothing => no explicit export list
- -> RnM NameSet
+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 (foldModuleEnv unionNameSets emptyNameSet imp_env)
+ inLoc fn (L span x)
+ = do x' <- fn x
+ return (L span x')
+ 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 (IEThingWith rdrName rdrNames)
+ = do name <- lookupGlobalOccRn rdrName
+ let env = mkOccEnv [(nameOccName s, s) | s <- subNames sub_env name]
+ mb_names = map (lookupOccEnv env . rdrNameOcc) rdrNames
+ if any isNothing mb_names
+ then -- The export error will be reporting in 'mkExportNameSet'
+ return (IEThingWith name [])
+ else return (IEThingWith name (catMaybes mb_names))
+ rnExport (IEModuleContents mod)
+ = return (IEModuleContents mod)
+ rn_exports <- mapM (inLoc rnExport) exports
+ return (Just rn_exports)
+
+mkExportNameSet :: Bool -- False => no 'module M(..) where' header at all
+ -> Maybe [LIE Name] -- Nothing => no explicit export list
+ -> RnM NameSet
-- Complains if two distinct exports have same OccName
-- Warns about identical exports.
-- Complains about exports items not in scope
-exportsFromAvail explicit_mod exports
- = do { TcGblEnv { tcg_rdr_env = rdr_env,
- tcg_imports = imports } <- getGblEnv ;
+mkExportNameSet explicit_mod exports
+ = do TcGblEnv { tcg_rdr_env = rdr_env,
+ tcg_imports = imports } <- getGblEnv
-- If the module header is omitted altogether, then behave
-- as if the user had written "module Main(main) where..."
-- written "module Main where ..."
-- Reason: don't want to complain about 'main' not in scope
-- in interactive mode
- ghci_mode <- getGhciMode ;
- let { real_exports
- | explicit_mod = exports
- | ghci_mode == Interactive = Nothing
- | otherwise = Just [noLoc (IEVar main_RDR_Unqual)] } ;
- exports_from_avail real_exports rdr_env imports }
+ ghci_mode <- getGhciMode
+ real_exports <- case () of
+ () | explicit_mod
+ -> return exports
+ | ghci_mode == Interactive
+ -> return Nothing
+ | otherwise
+ -> do mainName <- lookupGlobalOccRn main_RDR_Unqual
+ return (Just [noLoc (IEVar mainName)])
+ -- 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
isLocalGRE gre ])
exports_from_avail (Just items) rdr_env (ImportAvails { imp_env = imp_env })
- = foldlM do_litem emptyExportAccum items `thenM` \ (_, _, exports) ->
- returnM exports
+ = do (_, _, exports) <- foldlM do_litem emptyExportAccum items
+ return exports
where
sub_env :: NameEnv [Name] -- Classify each name by its parent
sub_env = mkSubNameEnv (foldModuleEnv unionNameSets emptyNameSet imp_env)
- do_litem :: ExportAccum -> Located (IE RdrName) -> RnM ExportAccum
+ do_litem :: ExportAccum -> LIE Name -> RnM ExportAccum
do_litem acc = addLocM (exports_from_item acc)
- exports_from_item :: ExportAccum -> IE RdrName -> RnM ExportAccum
+ exports_from_item :: ExportAccum -> IE Name -> RnM ExportAccum
exports_from_item acc@(mods, occs, exports) ie@(IEModuleContents mod)
| mod `elem` mods -- Duplicate export of M
= do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ;
| otherwise
= case lookupModuleEnv imp_env mod of
- Nothing -> addErr (modExportErr mod) `thenM_`
- returnM acc
- Just names
- -> let
- new_exports = filterNameSet (inScopeUnqual rdr_env) names
- in
-
- -- 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.
- check_occs ie occs (nameSetToList new_exports) `thenM` \ occs' ->
- returnM (mod:mods, occs', exports `unionNameSets` new_exports)
+ 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 ie occs (nameSetToList new_exports)
+ return (mod:mods, occs', exports `unionNameSets` new_exports)
exports_from_item acc@(mods, occs, exports) ie
- = lookupGlobalOccRn (ieName ie) `thenM` \ name ->
- if isUnboundName name then
- returnM acc -- Avoid error cascade
- else let
- new_exports = filterAvail ie name sub_env
- in
- checkErr (not (null new_exports)) (exportItemErr ie) `thenM_`
- checkForDodgyExport ie new_exports `thenM_`
- check_occs ie occs new_exports `thenM` \ occs' ->
- returnM (mods, occs', addListToNameSet exports new_exports)
+ = if isUnboundName (ieName ie)
+ then return acc -- Avoid error cascade
+ else let new_exports = filterAvail ie sub_env in
+ do checkErr (not (null new_exports)) (exportItemErr ie)
+ checkForDodgyExport ie new_exports
+ occs' <- check_occs ie occs new_exports
+ return (mods, occs', addListToNameSet exports new_exports)
-------------------------------
-filterAvail :: IE RdrName -- Wanted
- -> Name -- The Name of the ieName of the item
+filterAvail :: IE Name -- Wanted
-> NameEnv [Name] -- Maps type/class names to their sub-names
- -> [Name] -- Empty if even one thing reqd is missing
-
-filterAvail (IEVar _) n subs = [n]
-filterAvail (IEThingAbs _) n subs = [n]
-filterAvail (IEThingAll _) n subs = n : subNames subs n
-filterAvail (IEThingWith _ rdrs) n subs
- | any isNothing mb_names = []
- | otherwise = n : catMaybes mb_names
- where
- env = mkOccEnv [(nameOccName s, s) | s <- subNames subs n]
- mb_names = map (lookupOccEnv env . rdrNameOcc) rdrs
+ -> [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` []
inScopeUnqual env n = any unQualOK (lookupGRE_Name env n)
-------------------------------
-checkForDodgyExport :: IE RdrName -> [Name] -> RnM ()
+checkForDodgyExport :: IE Name -> [Name] -> RnM ()
checkForDodgyExport ie@(IEThingAll tc) [n]
| isTcOcc (nameOccName n) = addWarn (dodgyExportWarn tc)
-- This occurs when you export T(..), but
checkForDodgyExport _ _ = return ()
-------------------------------
-check_occs :: IE RdrName -> ExportOccMap -> [Name] -> RnM ExportOccMap
+check_occs :: IE Name -> ExportOccMap -> [Name] -> RnM ExportOccMap
check_occs ie occs names
= foldlM check occs names
where
reportDeprecations tcg_env
= ifOptM Opt_WarnDeprecations $
do { (eps,hpt) <- getEpsAndHpt
+ -- By this time, typechecking is complete,
+ -- so the PIT is fully populated
; mapM_ (check hpt (eps_PIT eps)) all_gres }
where
- used_names = findUses (tcg_dus tcg_env) emptyNameSet
+ used_names = allUses (tcg_dus tcg_env)
+ -- Report on all deprecated uses; hence allUses
all_gres = globalRdrEnvElts (tcg_rdr_env tcg_env)
- check hpt pit (GRE {gre_name = name, gre_prov = Imported (imp_spec:_) _})
+ check hpt pit (GRE {gre_name = name, gre_prov = Imported (imp_spec:_)})
| name `elemNameSet` used_names
, Just deprec_txt <- lookupDeprec hpt pit name
- = setSrcSpan (is_loc imp_spec) $
+ = setSrcSpan (importSpecLoc imp_spec) $
addWarn (sep [ptext SLIT("Deprecated use of") <+>
- occNameFlavour (nameOccName name) <+>
+ pprNonVarNameSpace (occNameSpace (nameOccName name)) <+>
quotes (ppr name),
- (parens imp_msg),
+ (parens imp_msg) <> colon,
(ppr deprec_txt) ])
where
name_mod = nameModule name
- imp_mod = is_mod imp_spec
+ imp_mod = importSpecModule imp_spec
imp_msg = ptext SLIT("imported from") <+> ppr imp_mod <> extra
extra | imp_mod == name_mod = empty
| otherwise = ptext SLIT(", but defined in") <+> ppr name_mod
%*********************************************************
\begin{code}
-reportUnusedNames :: Maybe [Located (IE RdrName)] -- Export list
+reportUnusedNames :: Maybe [LIE RdrName] -- Export list
-> TcGblEnv -> RnM ()
reportUnusedNames export_decls gbl_env
- = do { warnUnusedTopBinds unused_locals
+ = do { traceRn ((text "RUN") <+> (ppr (tcg_dus gbl_env)))
+ ; warnUnusedTopBinds unused_locals
; warnUnusedModules unused_imp_mods
; warnUnusedImports unused_imports
- ; warnDuplicateImports dup_imps
+ ; warnDuplicateImports defined_and_used
; printMinimalImports minimal_imports }
where
used_names, all_used_names :: NameSet
used_names = findUses (tcg_dus gbl_env) emptyNameSet
+ -- NB: currently, if f x = g, we only treat 'g' as used if 'f' is used
+ -- Hence findUses
+
all_used_names = used_names `unionNameSets`
mkNameSet (mapCatMaybes nameParent_maybe (nameSetToList used_names))
-- A use of C implies a use of T,
(defined_and_used, defined_but_not_used)
= partition (gre_is_used all_used_names) defined_names
- -- Find the duplicate imports
- dup_imps = filter is_dup defined_and_used
- is_dup (GRE {gre_prov = Imported imp_spec True}) = not (isSingleton imp_spec)
- is_dup other = False
-
-- Filter out the ones that are
-- (a) defined in this module, and
-- (b) not defined by a 'deriving' clause
unused_imports :: [GlobalRdrElt]
unused_imports = filter unused_imp defined_but_not_used
- unused_imp (GRE {gre_prov = Imported imp_specs True})
- = not (all (module_unused . is_mod) imp_specs)
+ unused_imp (GRE {gre_prov = Imported imp_specs})
+ = not (all (module_unused . importSpecModule) imp_specs)
+ && or [exp | ImpSpec { is_item = ImpSome { is_explicit = exp } } <- imp_specs]
-- Don't complain about unused imports if we've already said the
-- entire import is unused
unused_imp other = False
-- We've carefully preserved the provenance so that we can
-- construct minimal imports that import the name by (one of)
-- the same route(s) as the programmer originally did.
- add_name (GRE {gre_name = n, gre_prov = Imported imp_specs _}) acc
- = addToFM_C plusAvailEnv acc (is_mod (head imp_specs))
+ add_name (GRE {gre_name = n, gre_prov = Imported imp_specs}) acc
+ = addToFM_C plusAvailEnv acc (importSpecModule (head imp_specs))
(unitAvailEnv (mk_avail n (nameParent_maybe n)))
add_name other acc
= acc
imports = tcg_imports gbl_env
- direct_import_mods :: [(Module, Maybe Bool, SrcSpan)]
+ direct_import_mods :: [(Module, Bool, SrcSpan)]
-- See the type of the imp_mods for this triple
direct_import_mods = moduleEnvElts (imp_mods imports)
--
-- BUG WARNING: does not deal correctly with multiple imports of the same module
-- becuase direct_import_mods has only one entry per module
- unused_imp_mods = [(mod,loc) | (mod,imp,loc) <- direct_import_mods,
+ unused_imp_mods = [(mod,loc) | (mod,no_imp,loc) <- direct_import_mods,
not (mod `elemFM` minimal_imports1),
mod /= pRELUDE,
- imp /= Just False]
- -- The Just False part is not to complain about
+ not no_imp]
+ -- The not no_imp part is not to complain about
-- import M (), which is an idiom for importing
-- instance declarations
---------------------
warnDuplicateImports :: [GlobalRdrElt] -> RnM ()
+-- Given the GREs for names that are used, figure out which imports
+-- could be omitted without changing the top-level environment.
+--
+-- NB: Given import Foo( T )
+-- import qualified Foo
+-- we do not report a duplicate import, even though Foo.T is brought
+-- into scope by both, because there's nothing you can *omit* without
+-- changing the top-level environment. So we complain only if it's
+-- explicitly named in both imports or neither.
+--
+-- Furthermore, we complain about Foo.T only if
+-- there is no complaint about (unqualified) T
+
warnDuplicateImports gres
- = ifOptM Opt_WarnUnusedImports (mapM_ warn gres)
+ = ifOptM Opt_WarnUnusedImports $
+ sequenceM_ [ warn name pr
+ -- The 'head' picks the first offending group
+ -- for this particular name
+ | GRE { gre_name = name, gre_prov = Imported imps } <- gres
+ , pr <- redundants imps ]
where
- warn (GRE { gre_name = name, gre_prov = Imported imps _ })
- = addWarn ((quotes (ppr name) <+> ptext SLIT("is imported more than once:"))
- $$ nest 2 (vcat (map ppr imps)))
-
+ warn name (red_imp, cov_imp)
+ = addWarnAt (importSpecLoc red_imp)
+ (vcat [ptext SLIT("Redundant import of:") <+> quotes pp_name,
+ ptext SLIT("It is also") <+> ppr cov_imp])
+ where
+ pp_name | is_qual red_decl = ppr (is_as red_decl) <> dot <> ppr occ
+ | otherwise = ppr occ
+ occ = nameOccName name
+ red_decl = is_decl red_imp
+
+ redundants :: [ImportSpec] -> [(ImportSpec,ImportSpec)]
+ -- The returned pair is (redundant-import, covering-import)
+ redundants imps
+ = [ (red_imp, cov_imp)
+ | red_imp <- imps
+ , cov_imp <- take 1 (filter (covers red_imp) imps) ]
+
+ -- "red_imp" is a putative redundant import
+ -- "cov_imp" potentially covers it
+ -- This test decides whether red_imp could be dropped
+ --
+ -- NOTE: currently the test does not warn about
+ -- import M( x )
+ -- imoprt N( x )
+ -- even if the same underlying 'x' is involved, because dropping
+ -- either import would change the qualified names in scope (M.x, N.x)
+ -- But if the qualified names aren't used, the import is indeed redundant
+ -- Sadly we don't know that. Oh well.
+ covers red_imp@(ImpSpec { is_decl = red_decl, is_item = red_item })
+ cov_imp@(ImpSpec { is_decl = cov_decl, is_item = cov_item })
+ | red_loc == cov_loc
+ = False -- Ignore diagonal elements
+ | not (is_as red_decl == is_as cov_decl)
+ = False -- They bring into scope different qualified names
+ | not (is_qual red_decl) && is_qual cov_decl
+ = False -- Covering one doesn't bring unqualified name into scope
+ | red_selective
+ = not cov_selective -- Redundant one is selective and covering one isn't
+ || red_later -- Both are explicit; tie-break using red_later
+ | otherwise
+ = not cov_selective -- Neither import is selective
+ && (is_mod red_decl == is_mod cov_decl) -- They import the same module
+ && red_later -- Tie-break
+ where
+ red_loc = importSpecLoc red_imp
+ cov_loc = importSpecLoc cov_imp
+ red_later = red_loc > cov_loc
+ cov_selective = selectiveImpItem cov_item
+ red_selective = selectiveImpItem red_item
+
+selectiveImpItem :: ImpItemSpec -> Bool
+selectiveImpItem ImpAll = False
+selectiveImpItem (ImpSome {}) = True
-- ToDo: deal with original imports with 'qualified' and 'as M' clauses
printMinimalImports :: FiniteMap Module AvailEnv -- Minimal imports
(vcat (map ppr_mod_ie mod_ies)) })
}
where
- mkFilename this_mod = moduleUserString this_mod ++ ".imports"
+ mkFilename this_mod = moduleString this_mod ++ ".imports"
ppr_mod_ie (mod_name, ies)
| mod_name == pRELUDE
= empty
= ptext SLIT("import") <+> ppr mod_name <>
parens (fsep (punctuate comma (map ppr ies)))
- to_ies (mod, avail_env) = mappM to_ie (availEnvElts avail_env) `thenM` \ ies ->
- returnM (mod, ies)
+ to_ies (mod, avail_env) = do ies <- mapM to_ie (availEnvElts avail_env)
+ returnM (mod, ies)
to_ie :: AvailInfo -> RnM (IE Name)
-- The main trick here is that if we're importing all the constructors
%************************************************************************
\begin{code}
-badImportItemErr iface imp_spec ie
- = sep [ptext SLIT("Module"), quotes (ppr (is_mod imp_spec)), source_import,
+badImportItemErr iface decl_spec ie
+ = sep [ptext SLIT("Module"), quotes (ppr (is_mod decl_spec)), source_import,
ptext SLIT("does not export"), quotes (ppr ie)]
where
source_import | mi_boot iface = ptext SLIT("(hi-boot interface)")
(gre:_) -> gre
[] -> pprPanic "exportClashErr" (ppr name)
-addDupDeclErr :: [Name] -> TcRn ()
-addDupDeclErr names
- = addErrAt big_loc $
+addDupDeclErr :: Name -> Name -> TcRn ()
+addDupDeclErr name_a name_b
+ = addErrAt (srcLocSpan loc2) $
vcat [ptext SLIT("Multiple declarations of") <+> quotes (ppr name1),
- ptext SLIT("Declared at:") <+> vcat (map ppr sorted_locs)]
+ ptext SLIT("Declared at:") <+> vcat [ppr (nameSrcLoc name1), ppr loc2]]
where
- locs = map nameSrcLoc names
- big_loc = foldr1 combineSrcSpans (map srcLocSpan locs)
- name1 = head names
- sorted_locs = sortLe (<=) (sortLe (<=) locs)
+ loc2 = nameSrcLoc name2
+ (name1,name2) | nameSrcLoc name_a > nameSrcLoc name_b = (name_b,name_a)
+ | otherwise = (name_a,name_b)
+ -- Report the error at the later location
dupExportWarn occ_name ie1 ie2
= hsep [quotes (ppr occ_name),