\begin{code}
module RnNames (
- rnImports, importsFromLocalDecls, exportsFromAvail,
- reportUnusedNames, mkModDeps, main_RDR_Unqual
+ rnImports, importsFromLocalDecls,
+ reportUnusedNames, reportDeprecations,
+ mkModDeps, exportsToAvails, exportsFromAvail
) where
#include "HsVersions.h"
-import {-# SOURCE #-} RnHiFiles ( loadInterface )
-
import CmdLineOpts ( DynFlag(..) )
-
-import HsSyn ( IE(..), ieName, ImportDecl(..),
- ForeignDecl(..), HsGroup(..),
- collectLocatedHsBinders, tyClDeclNames
+import HsSyn ( IE(..), ieName, ImportDecl(..), LImportDecl,
+ ForeignDecl(..), HsGroup(..), HsBindGroup(..),
+ Sig(..), collectGroupBinders, tyClDeclNames
)
-import RdrHsSyn ( RdrNameIE, RdrNameImportDecl )
import RnEnv
+import IfaceEnv ( lookupOrig, newGlobalBinder )
+import LoadIface ( loadSrcInterface )
import TcRnMonad
import FiniteMap
-import PrelNames ( pRELUDE_Name, mAIN_Name, isBuiltInSyntaxName )
-import Module ( Module, ModuleName, ModuleEnv, moduleName,
- moduleNameUserString, isHomeModule,
- emptyModuleEnv, unitModuleEnvByName, unitModuleEnv,
- lookupModuleEnvByName, extendModuleEnvByName, moduleEnvElts )
-import Name ( Name, nameSrcLoc, nameOccName, nameModule, isExternalName )
+import PrelNames ( pRELUDE, isUnboundName, main_RDR_Unqual )
+import Module ( Module, moduleUserString,
+ unitModuleEnv, unitModuleEnv,
+ lookupModuleEnv, moduleEnvElts, foldModuleEnv )
+import Name ( Name, nameSrcLoc, nameOccName, nameModule, isWiredInName,
+ nameParent, nameParent_maybe, isExternalName,
+ isBuiltInSyntax )
import NameSet
import NameEnv
-import OccName ( OccName, srcDataName, isTcOcc )
-import HscTypes ( Provenance(..), ImportReason(..), GlobalRdrEnv,
- GenAvailInfo(..), AvailInfo, Avails,
- IsBootInterface,
- availName, availNames, availsToNameSet,
- Deprecations(..), ModIface(..), Dependencies(..),
- GlobalRdrElt(..), unQualInScope, isLocalGRE, pprNameProvenance
+import OccName ( srcDataName, isTcOcc, occNameFlavour, OccEnv,
+ mkOccEnv, lookupOccEnv, emptyOccEnv, extendOccEnv )
+import HscTypes ( GenAvailInfo(..), AvailInfo, GhciMode(..),
+ IfaceExport, HomePackageTable, PackageIfaceTable,
+ availNames, unQualInScope,
+ Deprecs(..), ModIface(..), Dependencies(..),
+ lookupIface, ExternalPackageState(..)
)
-import OccName ( varName )
-import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, lookupRdrEnv, rdrEnvToList,
- emptyRdrEnv, foldRdrEnv, rdrEnvElts, mkRdrUnqual, isQual, mkUnqual )
+import Packages ( PackageIdH(..) )
+import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace,
+ GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..),
+ emptyGlobalRdrEnv, plusGlobalRdrEnv, globalRdrEnvElts,
+ unQualOK, lookupGRE_Name,
+ Provenance(..), ImportSpec(..),
+ isLocalGRE, pprNameProvenance )
import Outputable
-import Maybe ( isJust, isNothing, catMaybes )
-import Maybes ( orElse )
+import Maybes ( isNothing, catMaybes, mapCatMaybes, seqMaybe, orElse )
+import SrcLoc ( noSrcLoc, Located(..), mkGeneralSrcSpan,
+ unLoc, noLoc, srcLocSpan, combineSrcSpans, SrcSpan )
+import BasicTypes ( DeprecTxt )
import ListSetOps ( removeDups )
-import Util ( sortLt, notNull )
-import List ( partition, insert )
+import Util ( sortLe, notNull, isSingleton )
+import List ( partition )
import IO ( openFile, IOMode(..) )
\end{code}
%************************************************************************
\begin{code}
-rnImports :: [RdrNameImportDecl]
- -> TcRn m (GlobalRdrEnv, ImportAvails)
+rnImports :: [LImportDecl RdrName]
+ -> RnM (GlobalRdrEnv, ImportAvails)
rnImports imports
- = -- PROCESS IMPORT DECLS
+ = do { -- PROCESS IMPORT DECLS
-- Do the non {- SOURCE -} ones first, so that we get a helpful
-- warning for {- SOURCE -} ones that are unnecessary
- getModule `thenM` \ this_mod ->
- getSrcLocM `thenM` \ loc ->
- doptM Opt_NoImplicitPrelude `thenM` \ opt_no_prelude ->
- let
- all_imports = mk_prel_imports this_mod loc opt_no_prelude ++ imports
- (source, ordinary) = partition is_source_import all_imports
- is_source_import (ImportDecl _ is_boot _ _ _ _) = is_boot
-
- get_imports = importsFromImportDecl this_mod
- in
- mappM get_imports ordinary `thenM` \ stuff1 ->
- mappM get_imports source `thenM` \ stuff2 ->
+ 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
+ ; let
(imp_gbl_envs, imp_avails) = unzip (stuff1 ++ stuff2)
gbl_env :: GlobalRdrEnv
- gbl_env = foldr plusGlobalRdrEnv emptyRdrEnv imp_gbl_envs
+ gbl_env = foldr plusGlobalRdrEnv emptyGlobalRdrEnv imp_gbl_envs
all_avails :: ImportAvails
all_avails = foldr plusImportAvails emptyImportAvails imp_avails
- in
+
-- ALL DONE
- returnM (gbl_env, all_avails)
+ ; 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 loc no_prelude
- | moduleName this_mod == pRELUDE_Name
+ mk_prel_imports this_mod implicit_prelude
+ | this_mod == pRELUDE
|| explicit_prelude_import
- || no_prelude
+ || not implicit_prelude
= []
- | otherwise = [preludeImportDecl loc]
+ | otherwise = [preludeImportDecl]
explicit_prelude_import
- = notNull [ () | (ImportDecl mod _ _ _ _ _) <- imports,
- mod == pRELUDE_Name ]
+ = notNull [ () | L _ (ImportDecl mod _ _ _ _) <- imports,
+ unLoc mod == pRELUDE ]
-preludeImportDecl loc
- = ImportDecl pRELUDE_Name
+preludeImportDecl
+ = L loc $
+ ImportDecl (L loc pRELUDE)
False {- Not a boot interface -}
False {- Not qualified -}
Nothing {- No "as" -}
Nothing {- No import list -}
- loc
+ where
+ loc = mkGeneralSrcSpan FSLIT("Implicit import declaration")
\end{code}
\begin{code}
importsFromImportDecl :: Module
- -> RdrNameImportDecl
- -> TcRn m (GlobalRdrEnv, ImportAvails)
+ -> LImportDecl RdrName
+ -> RnM (GlobalRdrEnv, ImportAvails)
importsFromImportDecl this_mod
- (ImportDecl imp_mod_name is_boot qual_only as_mod imp_spec iloc)
- = addSrcLoc iloc $
+ (L loc (ImportDecl loc_imp_mod_name want_boot qual_only as_mod imp_details))
+ =
+ setSrcSpan loc $
+
+ -- 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 ->
- -- If there's an error in loadInterface, (e.g. interface
- -- file not found) we get lots of spurious errors from 'filterImports'
- tryM (loadInterface doc imp_mod_name (ImportByUser is_boot)) `thenM` \ mb_iface ->
+ -- 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 )
- case mb_iface of {
- Left exn -> returnM (emptyRdrEnv, emptyImportAvails ) ;
- Right iface ->
+ -- 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_`
let
- imp_mod = mi_module iface
- avails_by_module = mi_exports iface
- deprecs = mi_deprecs iface
- is_orph = mi_orphan iface
- deps = mi_deps iface
-
- avails :: Avails
- avails = [ avail | (mod_name, avails) <- avails_by_module,
- mod_name /= this_mod_name,
- avail <- avails ]
- this_mod_name = moduleName this_mod
+ imp_mod = mi_module iface
+ deprecs = mi_deprecs iface
+ is_orph = mi_orphan iface
+ deps = mi_deps 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
--
-- 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 = ImportSpec { is_mod = imp_mod_name, is_qual = qual_only,
+ is_loc = loc, is_as = qual_mod_name }
in
- -- Filter the imports according to the import list
- filterImports imp_mod is_boot imp_spec avails `thenM` \ (filtered_avails, explicits) ->
+ -- Get the total imports, and filter them according to the import list
+ exportsToAvails filtered_exports `thenM` \ total_avails ->
+ filterImports iface imp_spec
+ imp_details total_avails `thenM` \ (avail_env, gbl_env) ->
+
+ getDOpts `thenM` \ dflags ->
let
-- Compute new transitive dependencies
- orphans | is_orph = insert imp_mod_name (dep_orphs deps)
+
+ orphans | is_orph = ASSERT( not (imp_mod_name `elem` dep_orphs deps) )
+ imp_mod_name : dep_orphs deps
| otherwise = dep_orphs deps
(dependent_mods, dependent_pkgs)
- | isHomeModule imp_mod
- = -- Imported module is from the home package
- -- Take its dependent modules and
- -- (a) remove this_mod (might be there as a hi-boot)
- -- (b) add imp_mod itself
+ = case mi_package iface of
+ HomePackage ->
+ -- Imported module is from the home package
+ -- Take its dependent modules and add imp_mod itself
-- Take its dependent packages unchanged
- ((imp_mod_name, is_boot) : filter not_self (dep_mods deps), dep_pkgs deps)
-
- | otherwise
- = -- Imported module is from another package
+ --
+ -- NB: (dep_mods deps) might include a hi-boot file
+ -- for the module being compiled, CM. Do *not* filter
+ -- this out (as we used to), because when we've
+ -- finished dealing with the direct imports we want to
+ -- know if any of them depended on CM.hi-boot, in
+ -- which case we should do the hi-boot consistency
+ -- check. See LoadIface.loadHiBootInterface
+ ((imp_mod_name, want_boot) : dep_mods deps, dep_pkgs deps)
+
+ ExtPackage pkg ->
+ -- Imported module is from another package
-- Dump the dependent modules
-- Add the package imp_mod comes from to the dependent packages
- -- from imp_mod
- ([], insert (mi_package iface) (dep_pkgs deps))
-
- not_self (m, _) = m /= this_mod_name
+ ASSERT2( not (pkg `elem` dep_pkgs deps), ppr pkg <+> ppr (dep_pkgs deps) )
+ ([], pkg : dep_pkgs deps)
- import_all = case imp_spec of
- (Just (False, _)) -> False -- Imports are spec'd explicitly
- other -> True -- Everything is imported,
- -- (or almost everything [hiding])
+ 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])
- qual_mod_name = case as_mod of
- Nothing -> imp_mod_name
- Just another_name -> another_name
-
-- 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.
- avail_env = mkAvailEnv filtered_avails
-
- mk_prov name = NonLocalDef (UserImport imp_mod iloc (name `elemNameSet` explicits))
- gbl_env = mkGlobalRdrEnv qual_mod_name (not qual_only)
- mk_prov filtered_avails deprecs
- imports = ImportAvails {
- imp_qual = unitModuleEnvByName qual_mod_name avail_env,
- imp_env = avail_env,
- imp_mods = unitModuleEnv imp_mod (imp_mod, import_all),
+ imports = ImportAvails {
+ imp_env = unitModuleEnv qual_mod_name avail_env,
+ imp_mods = unitModuleEnv imp_mod (imp_mod, import_all, loc),
imp_orphs = orphans,
imp_dep_mods = mkModDeps dependent_mods,
imp_dep_pkgs = dependent_pkgs }
) `thenM_`
returnM (gbl_env, imports)
- }
-mkModDeps :: [(ModuleName, IsBootInterface)]
- -> ModuleEnv (ModuleName, IsBootInterface)
-mkModDeps deps = foldl add emptyModuleEnv deps
- where
- add env elt@(m,_) = extendModuleEnvByName env m elt
+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 may only suck in the interface 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)
\end{code}
\begin{code}
importsFromLocalDecls :: HsGroup RdrName
- -> TcRn m (GlobalRdrEnv, ImportAvails)
+ -> RnM (GlobalRdrEnv, ImportAvails)
importsFromLocalDecls group
= getModule `thenM` \ this_mod ->
getLocalDeclBinders this_mod group `thenM` \ avails ->
-- 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_ (addErr . dupDeclErr) dups `thenM_`
+ mappM_ addDupDeclErr dups `thenM_`
- doptM Opt_NoImplicitPrelude `thenM` \ implicit_prelude ->
+ doptM Opt_ImplicitPrelude `thenM` \ implicit_prelude ->
let
- mod_name = moduleName this_mod
- mk_prov n = LocalDef -- Provenance is local
-
- unqual_imp = True -- Want unqualified names in scope
- gbl_env = mkGlobalRdrEnv mod_name unqual_imp mk_prov avails NoDeprecs
- -- NoDeprecs: don't complain about locally defined names
- -- For a start, we may be exporting a deprecated thing
- -- Also we may use a deprecated thing in the defn of another
- -- deprecated things. We may even use a deprecated thing in
- -- the defn of a non-deprecated thing, when changing a module's
- -- interface
-
+ prov = LocalDef this_mod
+ gbl_env = mkGlobalRdrEnv gres
+ gres = [ GRE { gre_name = name, gre_prov = prov}
+ | name <- all_names]
-- Optimisation: filter out names for built-in syntax
-- They just clutter up the environment (esp tuples), and the parser
-- It's worth doing because it makes the environment smaller for
-- every module that imports the Prelude
--
- -- Note: don't filter the gbl_env (hence avails, not avails' in
- -- defn of gbl_env above). Stupid reason: when parsing
+ -- Note: don't filter the gbl_env (hence all_names, not filered_all_names
+ -- in defn of gres above). Stupid reason: when parsing
-- data type decls, the constructors start as Exact tycon-names,
-- and then get turned into data con names by zapping the name space;
- -- but that stops them being Exact, so they get looked up. Sigh.
- -- It doesn't matter because it only affects the Data.Tuple really.
+ -- but that stops them being Exact, so they get looked up.
+ -- 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
- avails' | implicit_prelude = filter not_built_in_syntax avails
- | otherwise = avails
- not_built_in_syntax a = not (all isBuiltInSyntaxName (availNames a))
- -- Only filter it if all the names of the avail are built-in
- -- In particular, lists have (:) which is not built in syntax
- -- so we don't filter it out.
-
- avail_env = mkAvailEnv avails'
- imports = emptyImportAvails {
- imp_qual = unitModuleEnv this_mod avail_env,
- imp_env = avail_env
+ imports = emptyImportAvails {
+ imp_env = unitModuleEnv this_mod $
+ mkNameSet filtered_names
}
in
returnM (gbl_env, imports)
%* *
%*********************************************************
-@getLocalDeclBinders@ returns the names for a @RdrNameHsDecl@. It's
-used for both source code (from @importsFromLocalDecls@) and interface
-files (@loadDecl@ calls @getTyClDeclBinders@).
+@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 -> TcRn m [AvailInfo]
+getLocalDeclBinders :: Module -> HsGroup RdrName -> RnM [AvailInfo]
getLocalDeclBinders mod (HsGroup {hs_valds = val_decls,
hs_tyclds = tycl_decls,
hs_fords = foreign_decls })
-- 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 ->
- mappM new_bndr (for_hs_bndrs ++ val_hs_bndrs) `thenM` \ simple_bndrs ->
+ mappM new_tc tycl_decls `thenM` \ tc_avails ->
+
+ -- 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 ->
- returnM (tc_avails ++ map Avail simple_bndrs)
+ returnM (tc_avails ++ map Avail names)
where
- new_bndr (rdr_name,loc) = newTopBinder mod rdr_name loc
+ new_simple rdr_name = newTopSrcBinder mod Nothing rdr_name
- val_hs_bndrs = collectLocatedHsBinders val_decls
- for_hs_bndrs = [(nm,loc) | ForeignImport nm _ _ _ loc <- foreign_decls]
+ sig_hs_bndrs = [nm | HsBindGroup _ lsigs _ <- val_decls,
+ L _ (Sig nm _) <- lsigs]
+ val_hs_bndrs = collectGroupBinders val_decls
+ for_hs_bndrs = [nm | L _ (ForeignImport nm _ _ _) <- foreign_decls]
- new_tc tc_decl = mappM new_bndr (tyClDeclNames tc_decl) `thenM` \ names@(main_name:_) ->
- returnM (AvailTC main_name names)
+ 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))
+ where
+ (main_rdr : sub_rdrs) = tyClDeclNames (unLoc tc_decl)
\end{code}
available, and filters it through the import spec (if any).
\begin{code}
-filterImports :: Module -- The module being imported
- -> IsBootInterface -- Tells whether it's a {-# SOURCE #-} import
- -> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hiding
- -> [AvailInfo] -- What's available
- -> TcRn m ([AvailInfo], -- What's imported
- NameSet) -- What was imported explicitly
+filterImports :: ModIface
+ -> ImportSpec -- The span for the entire import decl
+ -> Maybe (Bool, [Located (IE RdrName)]) -- 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.
-filterImports mod from Nothing imports
- = returnM (imports, emptyNameSet)
+
+mkGenericRdrEnv imp_spec names
+ = mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = Imported [imp_spec] False }
+ | name <- nameSetToList names ]
+
+filterImports iface imp_spec Nothing all_names
+ = returnM (all_names, mkGenericRdrEnv imp_spec all_names)
-filterImports mod from (Just (want_hiding, import_items)) total_avails
- = mappM get_item import_items `thenM` \ avails_w_explicits_s ->
+filterImports iface imp_spec (Just (want_hiding, import_items)) all_names
+ = mappM (addLocM get_item) import_items `thenM` \ gres_s ->
let
- (item_avails, explicits_s) = unzip (concat avails_w_explicits_s)
- explicits = foldl addListToNameSet emptyNameSet explicits_s
+ gres = concat gres_s
+ specified_names = mkNameSet (map gre_name gres)
in
- if want_hiding then
- let -- All imported; item_avails to be hidden
- hidden = availsToNameSet item_avails
- keep n = not (n `elemNameSet` hidden)
- in
- returnM (pruneAvails keep total_avails, emptyNameSet)
+ if not want_hiding then
+ return (specified_names, mkGlobalRdrEnv gres)
else
- -- Just item_avails imported; nothing to be hidden
- returnM (item_avails, explicits)
+ let
+ keep n = not (n `elemNameSet` specified_names)
+ pruned_avails = filterNameSet keep all_names
+ in
+ return (pruned_avails, mkGenericRdrEnv imp_spec pruned_avails)
+
where
- import_fm :: FiniteMap OccName AvailInfo
- import_fm = listToFM [ (nameOccName name, avail)
- | avail <- total_avails,
- name <- availNames avail]
- -- Even though availNames returns data constructors too,
+ 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.
- bale_out item = addErr (badImportItemErr mod from item) `thenM_`
+ sub_env :: NameEnv [Name]
+ sub_env = mkSubNameEnv all_names
+
+ bale_out item = addErr (badImportItemErr iface imp_spec item) `thenM_`
returnM []
- get_item :: RdrNameIE -> TcRn m [(AvailInfo, [Name])]
- -- Empty list for a bad item.
- -- Singleton is typical case.
+ 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)
+
+ get_item :: IE RdrName -> 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.
- -- The [Name] is the list of explicitly-mentioned names
- get_item item@(IEModuleContents _) = bale_out item
+ get_item item@(IEModuleContents _)
+ = bale_out item
- get_item item@(IEThingAll _)
+ get_item item@(IEThingAll tc)
= case check_item item of
- Nothing -> bale_out item
- Just avail@(AvailTC _ [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_WarnMisc (addWarn (dodgyImportWarn mod item)) `thenM_`
- returnM [(avail, [availName avail])]
- Just avail -> returnM [(avail, [availName avail])]
+ [] -> bale_out item
+
+ [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]
+
+ names -> succeed_with False names
get_item item@(IEThingAbs n)
| want_hiding -- hiding( C )
- -- Here the 'C' can be a data constructor *or* a type/class
- = case catMaybes [check_item item, check_item (IEVar data_n)] of
- [] -> bale_out item
- avails -> returnM [(a, []) | a <- avails]
- -- The 'explicits' list is irrelevant when hiding
+ -- 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
- Nothing -> bale_out item
- Just avail -> returnM [(avail, availNames avail)]
-
- check_item item
- | isNothing maybe_in_import_avails ||
- isNothing maybe_filtered_avail
- = Nothing
-
- | otherwise
- = Just filtered_avail
-
- where
- wanted_occ = rdrNameOcc (ieName item)
- maybe_in_import_avails = lookupFM import_fm wanted_occ
-
- Just avail = maybe_in_import_avails
- maybe_filtered_avail = filterAvail item avail
- Just filtered_avail = maybe_filtered_avail
-\end{code}
-
-\begin{code}
-filterAvail :: RdrNameIE -- Wanted
- -> AvailInfo -- Available
- -> Maybe AvailInfo -- Resulting available;
- -- Nothing if (any of the) wanted stuff isn't there
-
-filterAvail ie@(IEThingWith want wants) avail@(AvailTC n ns)
- | sub_names_ok = Just (AvailTC n (filter is_wanted ns))
- | otherwise = Nothing
- where
- is_wanted name = nameOccName name `elem` wanted_occs
- sub_names_ok = all (`elem` avail_occs) wanted_occs
- avail_occs = map nameOccName ns
- wanted_occs = map rdrNameOcc (want:wants)
-
-filterAvail (IEThingAbs _) (AvailTC n ns) = ASSERT( n `elem` ns )
- Just (AvailTC n [n])
-
-filterAvail (IEThingAbs _) avail@(Avail n) = Just avail -- Type synonyms
-
-filterAvail (IEVar _) avail@(Avail n) = Just avail
-filterAvail (IEVar v) avail@(AvailTC n ns) = Just (AvailTC n (filter wanted ns))
- where
- wanted n = nameOccName n == occ
- occ = rdrNameOcc v
- -- The second equation happens if we import a class op, thus
- -- import A( op )
- -- where op is a class operation
-
-filterAvail (IEThingAll _) avail@(AvailTC _ _) = Just avail
- -- We don't complain even if the IE says T(..), but
- -- no constrs/class ops of T are available
- -- Instead that's caught with a warning by the caller
-
-filterAvail ie avail = Nothing
+ [] -> 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
- = ([ModuleName], -- 'module M's seen so far
+ = ([Module], -- 'module M's seen so far
ExportOccMap, -- Tracks exported occurrence names
- AvailEnv) -- The accumulated exported stuff, kept in an env
- -- so we can common-up related AvailInfos
-emptyExportAccum = ([], emptyFM, emptyAvailEnv)
+ NameSet) -- The accumulated exported stuff
+emptyExportAccum = ([], emptyOccEnv, emptyNameSet)
-type ExportOccMap = FiniteMap OccName (Name, RdrNameIE)
+type ExportOccMap = OccEnv (Name, IE RdrName)
-- 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 :: Maybe [RdrNameIE] -> TcRn m Avails
+exportsFromAvail :: Bool -- False => no 'module M(..) where' header at all
+ -> Maybe [Located (IE RdrName)] -- 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 exports
+exportsFromAvail explicit_mod exports
= do { TcGblEnv { tcg_rdr_env = rdr_env,
tcg_imports = imports } <- getGblEnv ;
- exports_from_avail exports rdr_env imports }
-
-exports_from_avail Nothing rdr_env
- imports@(ImportAvails { imp_env = entity_avail_env })
- = do { this_mod <- getModule ;
- if moduleName this_mod == mAIN_Name then
- exports_from_avail (Just [IEVar main_RDR_Unqual]) rdr_env imports
- -- Behave just as if we'd said module Main(main)
- -- This is particularly important if we compile module Main,
- -- but then use ghci to call it... we jolly well expect to
- -- see 'main'!
- else
- -- Export all locally-defined things
- -- We do this by filtering the global RdrEnv,
- -- keeping only things that are (a) qualified,
- -- (b) locally defined, (c) a 'main' name
- -- Then we look up in the entity-avail-env
- return [ lookupAvailEnv entity_avail_env name
- | (rdr_name, gres) <- rdrEnvToList rdr_env,
- isQual rdr_name, -- Avoid duplicates
- GRE { gre_name = name,
- gre_parent = Nothing, -- Main things only
- gre_prov = LocalDef } <- gres
- ]
- }
-
-exports_from_avail (Just export_items) rdr_env
- (ImportAvails { imp_qual = mod_avail_env,
- imp_env = entity_avail_env })
- = foldlM exports_from_item emptyExportAccum
- export_items `thenM` \ (_, _, export_avail_map) ->
- returnM (nameEnvElts export_avail_map)
+ -- If the module header is omitted altogether, then behave
+ -- as if the user had written "module Main(main) where..."
+ -- EXCEPT in interactive mode, when we behave as if he had
+ -- 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 }
+
+
+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) rdr_env (ImportAvails { imp_env = imp_env })
+ = foldlM do_litem emptyExportAccum items `thenM` \ (_, _, exports) ->
+ returnM exports
where
- exports_from_item :: ExportAccum -> RdrNameIE -> TcRn m ExportAccum
+ 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 acc = addLocM (exports_from_item acc)
- exports_from_item acc@(mods, occs, avails) ie@(IEModuleContents mod)
+ exports_from_item :: ExportAccum -> IE RdrName -> 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 ;
warnIf warn_dup_exports (dupModuleExport mod) ;
returnM acc }
| otherwise
- = case lookupModuleEnvByName mod_avail_env mod of
+ = case lookupModuleEnv imp_env mod of
Nothing -> addErr (modExportErr mod) `thenM_`
returnM acc
-
- Just avail_env
+ Just names
-> let
- mod_avails = [ filtered_avail
- | avail <- availEnvElts avail_env,
- let mb_avail = filter_unqual rdr_env avail,
- isJust mb_avail,
- let Just filtered_avail = mb_avail]
-
- avails' = foldl addAvail avails mod_avails
+ 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.
-
- foldlM (check_occs ie) occs mod_avails `thenM` \ occs' ->
- returnM (mod:mods, occs', avails')
-
- exports_from_item acc@(mods, occs, avails) ie
- = lookupGRE (ieName ie) `thenM` \ mb_gre ->
- case mb_gre of {
- Nothing -> addErr (unknownNameErr (ieName ie)) `thenM_`
- returnM acc ;
- Just gre ->
-
- -- Get the AvailInfo for the parent of the specified name
- let
- parent = gre_parent gre `orElse` gre_name gre
- avail = lookupAvailEnv entity_avail_env parent
+ check_occs ie occs (nameSetToList new_exports) `thenM` \ occs' ->
+ returnM (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
- -- Filter out the bits we want
- case filterAvail ie avail of {
- Nothing -> -- Not enough availability
- addErr (exportItemErr ie) `thenM_`
- returnM acc ;
-
- Just export_avail ->
-
- -- Phew! It's OK! Now to check the occurrence stuff!
- warnIf (not (ok_item ie avail)) (dodgyExportWarn ie) `thenM_`
- check_occs ie occs export_avail `thenM` \ occs' ->
- returnM (mods, occs', addAvail avails export_avail)
- }}
+ 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)
+
+-------------------------------
+filterAvail :: IE RdrName -- Wanted
+ -> Name -- The Name of the ieName of the item
+ -> 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
+subNames :: NameEnv [Name] -> Name -> [Name]
+subNames env n = lookupNameEnv env n `orElse` []
--------------------------------
-filter_unqual :: GlobalRdrEnv -> AvailInfo -> Maybe AvailInfo
--- Filter the Avail by what's in scope unqualified
-filter_unqual env (Avail n)
- | in_scope env n = Just (Avail n)
- | otherwise = Nothing
-filter_unqual env (AvailTC n ns)
- | not (null ns') = Just (AvailTC n ns')
- | otherwise = Nothing
+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
- ns' = filter (in_scope env) ns
+ add_name name env
+ | Just parent <- nameParent_maybe name
+ = extendNameEnv_C (\ns _ -> name:ns) env parent [name]
+ | otherwise = env
-in_scope :: GlobalRdrEnv -> Name -> Bool
+-------------------------------
+inScopeUnqual :: GlobalRdrEnv -> Name -> Bool
-- Checks whether the Name is in scope unqualified,
-- regardless of whether it's ambiguous or not
-in_scope env n
- = case lookupRdrEnv env (mkRdrUnqual (nameOccName n)) of
- Nothing -> False
- Just gres -> or [n == gre_name g | g <- gres]
-
+inScopeUnqual env n = any unQualOK (lookupGRE_Name env n)
-------------------------------
-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
+checkForDodgyExport :: IE RdrName -> [Name] -> RnM ()
+checkForDodgyExport ie@(IEThingAll tc) [n]
+ | isTcOcc (nameOccName n) = addWarn (dodgyExportWarn tc)
+ -- This occurs when you export T(..), but
+ -- only import T abstractly, or T is a synonym.
+ -- The single [n] is the type or class itself
+ | otherwise = addErr (exportItemErr ie)
+ -- This happes if you export x(..), which is bogus
+checkForDodgyExport _ _ = return ()
-------------------------------
-check_occs :: RdrNameIE -> ExportOccMap -> AvailInfo -> TcRn m ExportOccMap
-check_occs ie occs avail
- = foldlM check occs (availNames avail)
+check_occs :: IE RdrName -> ExportOccMap -> [Name] -> RnM ExportOccMap
+check_occs ie occs names
+ = foldlM check occs names
where
check occs name
- = case lookupFM occs name_occ of
- Nothing -> returnM (addToFM occs name_occ (name, ie))
+ = case lookupOccEnv occs name_occ of
+ Nothing -> returnM (extendOccEnv occs name_occ (name, ie))
Just (name', ie')
| name == name' -- Duplicate export
returnM occs }
where
name_occ = nameOccName name
+\end{code}
+
+%*********************************************************
+%* *
+ Deprecations
+%* *
+%*********************************************************
-----------------------------
-main_RDR_Unqual :: RdrName
-main_RDR_Unqual = mkUnqual varName FSLIT("main")
- -- Don't get a RdrName from PrelNames.mainName, because
- -- nameRdrNamegets an Orig RdrName, and we want a Qual or Unqual one.
- -- An Unqual one will do just fine
+\begin{code}
+reportDeprecations :: TcGblEnv -> RnM ()
+reportDeprecations tcg_env
+ = ifOptM Opt_WarnDeprecations $
+ do { (eps,hpt) <- getEpsAndHpt
+ ; mapM_ (check hpt (eps_PIT eps)) all_gres }
+ where
+ used_names = findUses (tcg_dus tcg_env) emptyNameSet
+ all_gres = globalRdrEnvElts (tcg_rdr_env tcg_env)
+
+ 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) $
+ addWarn (sep [ptext SLIT("Deprecated use of") <+>
+ occNameFlavour (nameOccName name) <+>
+ quotes (ppr name),
+ (parens imp_msg),
+ (ppr deprec_txt) ])
+ where
+ name_mod = nameModule name
+ imp_mod = is_mod 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
+
+ check hpt pit ok_gre = returnM () -- Local, or not used, or not deprectated
+ -- The Imported pattern-match: don't deprecate locally defined names
+ -- For a start, we may be exporting a deprecated thing
+ -- Also we may use a deprecated thing in the defn of another
+ -- deprecated things. We may even use a deprecated thing in
+ -- the defn of a non-deprecated thing, when changing a module's
+ -- interface
+
+lookupDeprec :: HomePackageTable -> PackageIfaceTable
+ -> Name -> Maybe DeprecTxt
+lookupDeprec hpt pit n
+ = case lookupIface 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
+ Nothing
+ | isWiredInName n -> Nothing
+ -- We have not necessarily loaded the .hi file for a
+ -- wired-in name (yet), although we *could*.
+ -- And we never deprecate them
+
+ | otherwise -> pprPanic "lookupDeprec" (ppr n)
+ -- By now all the interfaces should have been loaded
+
+gre_is_used :: NameSet -> GlobalRdrElt -> Bool
+gre_is_used used_names gre = gre_name gre `elemNameSet` used_names
\end{code}
%*********************************************************
%* *
-\subsection{Unused names}
+ Unused names
%* *
%*********************************************************
\begin{code}
-reportUnusedNames :: TcGblEnv -> DefUses -> TcRn m ()
-reportUnusedNames gbl_env dus
- = warnUnusedModules unused_imp_mods `thenM_`
- warnUnusedTopBinds bad_locals `thenM_`
- warnUnusedImports bad_imports `thenM_`
- printMinimalImports minimal_imports
+reportUnusedNames :: Maybe [Located (IE RdrName)] -- Export list
+ -> TcGblEnv -> RnM ()
+reportUnusedNames export_decls gbl_env
+ = do { warnUnusedTopBinds unused_locals
+ ; warnUnusedModules unused_imp_mods
+ ; warnUnusedImports unused_imports
+ ; warnDuplicateImports dup_imps
+ ; printMinimalImports minimal_imports }
where
- used_names :: NameSet
- used_names = findUses dus emptyNameSet
+ used_names, all_used_names :: NameSet
+ used_names = findUses (tcg_dus gbl_env) emptyNameSet
+ all_used_names = used_names `unionNameSets`
+ mkNameSet (mapCatMaybes nameParent_maybe (nameSetToList used_names))
+ -- A use of C implies a use of T,
+ -- if C was brought into scope by T(..) or T(C)
-- Collect the defined names from the in-scope environment
- -- Look for the qualified ones only, else get duplicates
defined_names :: [GlobalRdrElt]
- defined_names = foldRdrEnv add [] (tcg_rdr_env gbl_env)
- add rdr_name ns acc | isQual rdr_name = ns ++ acc
- | otherwise = acc
+ defined_names = globalRdrEnvElts (tcg_rdr_env gbl_env)
+ -- Note that defined_and_used, defined_but_not_used
+ -- are both [GRE]; that's why we need defined_and_used
+ -- rather than just all_used_names
defined_and_used, defined_but_not_used :: [GlobalRdrElt]
- (defined_and_used, defined_but_not_used) = partition is_used defined_names
-
- is_used gre = n `elemNameSet` used_names || any (`elemNameSet` used_names) kids
- -- The 'kids' part is because a use of C implies a use of T,
- -- if C was brought into scope by T(..) or T(C)
- where
- n = gre_name gre
- kids = case lookupAvailEnv_maybe avail_env n of
- Just (AvailTC n ns) -> ns
- other -> [] -- Ids, class ops and datacons
- -- (The latter two give Nothing)
+ (defined_and_used, defined_but_not_used)
+ = partition (gre_is_used all_used_names) defined_names
- -- Filter out the ones that are
- -- (a) defined in this module, and
- -- (b) not defined by a 'deriving' clause
- -- The latter have an Internal Name, so we can filter them out easily
- bad_locals :: [GlobalRdrElt]
- bad_locals = filter is_bad defined_but_not_used
- is_bad :: GlobalRdrElt -> Bool
- is_bad gre = isLocalGRE gre && isExternalName (gre_name gre)
+ -- 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
+ -- The latter have an Internal Name, so we can filter them out easily
+ unused_locals :: [GlobalRdrElt]
+ unused_locals = filter is_unused_local defined_but_not_used
+ is_unused_local :: GlobalRdrElt -> Bool
+ is_unused_local gre = isLocalGRE gre && isExternalName (gre_name gre)
- bad_imports :: [GlobalRdrElt]
- bad_imports = filter bad_imp defined_but_not_used
- bad_imp (GRE {gre_prov = NonLocalDef (UserImport mod _ True)}) = not (module_unused mod)
- bad_imp other = False
+ 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)
+ -- Don't complain about unused imports if we've already said the
+ -- entire import is unused
+ unused_imp other = False
-- To figure out the minimal set of imports, start with the things
-- that are in scope (i.e. in gbl_env). Then just combine them
-- into a bunch of avails, so they are properly grouped
- minimal_imports :: FiniteMap ModuleName AvailEnv
- minimal_imports0 = emptyFM
+ --
+ -- BUG WARNING: this does not deal properly with qualified imports!
+ minimal_imports :: FiniteMap Module AvailEnv
+ minimal_imports0 = foldr add_expall emptyFM expall_mods
minimal_imports1 = foldr add_name minimal_imports0 defined_and_used
minimal_imports = foldr add_inst_mod minimal_imports1 direct_import_mods
-- The last line makes sure that we retain all direct imports
-- There's really no good way to detect this, so the error message
-- in RnEnv.warnUnusedModules is weakened instead
-
-- 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_parent = p,
- gre_prov = NonLocalDef (UserImport m _ _)}) acc
- = addToFM_C plusAvailEnv acc (moduleName m)
- (unitAvailEnv (mk_avail n p))
+ add_name (GRE {gre_name = n, gre_prov = Imported imp_specs _}) acc
+ = addToFM_C plusAvailEnv acc (is_mod (head imp_specs))
+ (unitAvailEnv (mk_avail n (nameParent_maybe n)))
add_name other acc
= acc
+ -- Modules mentioned as 'module M' in the export list
+ expall_mods = case export_decls of
+ Nothing -> []
+ Just es -> [m | L _ (IEModuleContents m) <- es]
+
+ -- This is really bogus. The idea is that if we see 'module M' in
+ -- the export list we must retain the import decls that drive it
+ -- If we aren't careful we might see
+ -- module A( module M ) where
+ -- import M
+ -- import N
+ -- and suppose that N exports everything that M does. Then we
+ -- must not drop the import of M even though N brings it all into
+ -- scope.
+ --
+ -- BUG WARNING: 'module M' exports aside, what if M.x is mentioned?!
+ --
+ -- The reason that add_expall is bogus is that it doesn't take
+ -- qualified imports into account. But it's an improvement.
+ add_expall mod acc = addToFM_C plusAvailEnv acc mod emptyAvailEnv
+
-- n is the name of the thing, p is the name of its parent
mk_avail n (Just p) = AvailTC p [p,n]
mk_avail n Nothing | isTcOcc (nameOccName n) = AvailTC n [n]
| otherwise = Avail n
- add_inst_mod m acc
- | m `elemFM` acc = acc -- We import something already
- | otherwise = addToFM acc m emptyAvailEnv
+ add_inst_mod (mod,_,_) acc
+ | mod `elemFM` acc = acc -- We import something already
+ | otherwise = addToFM acc mod emptyAvailEnv
+ where
-- Add an empty collection of imports for a module
-- from which we have sucked only instance decls
- imports = tcg_imports gbl_env
- avail_env = imp_env imports
+ imports = tcg_imports gbl_env
- direct_import_mods :: [ModuleName]
- direct_import_mods = map (moduleName . fst)
- (moduleEnvElts (imp_mods imports))
+ direct_import_mods :: [(Module, Maybe Bool, SrcSpan)]
+ -- See the type of the imp_mods for this triple
+ direct_import_mods = moduleEnvElts (imp_mods imports)
-- unused_imp_mods are the directly-imported modules
-- that are not mentioned in minimal_imports1
- -- [Note: not 'minimal_imports', because that includes direcly-imported
+ -- [Note: not 'minimal_imports', because that includes directly-imported
-- modules even if we use nothing from them; see notes above]
- unused_imp_mods = [m | m <- direct_import_mods,
- isNothing (lookupFM minimal_imports1 m),
- m /= pRELUDE_Name]
+ --
+ -- 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,
+ not (mod `elemFM` minimal_imports1),
+ mod /= pRELUDE,
+ imp /= Just False]
+ -- The Just False part is not to complain about
+ -- import M (), which is an idiom for importing
+ -- instance declarations
module_unused :: Module -> Bool
- module_unused mod = moduleName mod `elem` unused_imp_mods
+ module_unused mod = any (((==) mod) . fst) unused_imp_mods
+---------------------
+warnDuplicateImports :: [GlobalRdrElt] -> RnM ()
+warnDuplicateImports gres
+ = ifOptM Opt_WarnUnusedImports (mapM_ warn gres)
+ 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)))
+
-- ToDo: deal with original imports with 'qualified' and 'as M' clauses
-printMinimalImports :: FiniteMap ModuleName AvailEnv -- Minimal imports
- -> TcRn m ()
+printMinimalImports :: FiniteMap Module AvailEnv -- Minimal imports
+ -> RnM ()
printMinimalImports imps
= ifOptM Opt_D_dump_minimal_imports $ do {
(vcat (map ppr_mod_ie mod_ies)) })
}
where
- mkFilename this_mod = moduleNameUserString (moduleName this_mod) ++ ".imports"
+ mkFilename this_mod = moduleUserString this_mod ++ ".imports"
ppr_mod_ie (mod_name, ies)
- | mod_name == pRELUDE_Name
+ | mod_name == pRELUDE
= empty
| null ies -- Nothing except instances comes from here
= ptext SLIT("import") <+> ppr mod_name <> ptext SLIT("() -- Instances only")
to_ies (mod, avail_env) = mappM to_ie (availEnvElts avail_env) `thenM` \ ies ->
returnM (mod, ies)
- to_ie :: AvailInfo -> TcRn m (IE Name)
+ to_ie :: AvailInfo -> RnM (IE Name)
-- The main trick here is that if we're importing all the constructors
-- we want to say "T(..)", but if we're importing only a subset we want
-- to say "T(A,B,C)". So we have to find out what the module exports.
to_ie (AvailTC n [m]) = ASSERT( n==m )
returnM (IEThingAbs n)
to_ie (AvailTC n ns)
- = loadInterface (text "Compute minimal imports from" <+> ppr n_mod)
- n_mod ImportBySystem `thenM` \ iface ->
+ = loadSrcInterface doc n_mod False `thenM` \ iface ->
case [xs | (m,as) <- mi_exports iface,
m == n_mod,
AvailTC x xs <- as,
- x == n] of
- [xs] | all (`elem` ns) xs -> returnM (IEThingAll n)
- | otherwise -> returnM (IEThingWith n (filter (/= n) ns))
- other -> pprTrace "to_ie" (ppr n <+> ppr (nameModule n) <+> ppr other) $
- returnM (IEVar n)
+ x == nameOccName n] of
+ [xs] | all_used xs -> returnM (IEThingAll n)
+ | otherwise -> returnM (IEThingWith n (filter (/= n) ns))
+ other -> pprTrace "to_ie" (ppr n <+> ppr n_mod <+> ppr other) $
+ returnM (IEVar n)
where
- n_mod = moduleName (nameModule n)
+ all_used avail_occs = all (`elem` map nameOccName ns) avail_occs
+ doc = text "Compute minimal imports from" <+> ppr n
+ n_mod = nameModule n
\end{code}
%************************************************************************
\begin{code}
-badImportItemErr mod from ie
- = sep [ptext SLIT("Module"), quotes (ppr mod), source_import,
+badImportItemErr iface imp_spec ie
+ = sep [ptext SLIT("Module"), quotes (ppr (is_mod imp_spec)), source_import,
ptext SLIT("does not export"), quotes (ppr ie)]
where
- source_import = case from of
- True -> ptext SLIT("(hi-boot interface)")
- other -> empty
+ source_import | mi_boot iface = ptext SLIT("(hi-boot interface)")
+ | otherwise = empty
-dodgyImportWarn mod item = dodgyMsg (ptext SLIT("import")) item
-dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item
+dodgyImportWarn item = dodgyMsg (ptext SLIT("import")) item
+dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item
-dodgyMsg kind item@(IEThingAll tc)
- = sep [ ptext SLIT("The") <+> kind <+> ptext SLIT("item") <+> quotes (ppr item),
+dodgyMsg kind tc
+ = sep [ ptext SLIT("The") <+> kind <+> ptext SLIT("item") <+> quotes (ppr (IEThingAll tc)),
ptext SLIT("suggests that") <+> quotes (ppr tc) <+> ptext SLIT("has constructor or class methods"),
ptext SLIT("but it has none; it is a type synonym or abstract type or class") ]
ppr_export ie name = nest 2 (quotes (ppr ie) <+> ptext SLIT("exports") <+>
quotes (ppr name) <+> pprNameProvenance (get_gre name))
- -- get_gre finds a GRE for the Name, in a very inefficient way
- -- There isn't a more efficient way to do it, because we don't necessarily
- -- know the RdrName under which this Name is in scope. So we just
- -- search linearly. Shouldn't matter because this only happens
- -- in an error message.
+ -- get_gre finds a GRE for the Name, so that we can show its provenance
get_gre name
- = case [gre | gres <- rdrEnvElts global_env,
- gre <- gres,
- gre_name gre == name] of
+ = case lookupGRE_Name global_env name of
(gre:_) -> gre
[] -> pprPanic "exportClashErr" (ppr name)
-dupDeclErr (n:ns)
- = vcat [ptext SLIT("Multiple declarations of") <+> quotes (ppr n),
- nest 4 (vcat (map ppr sorted_locs))]
+addDupDeclErr :: [Name] -> TcRn ()
+addDupDeclErr names
+ = addErrAt big_loc $
+ vcat [ptext SLIT("Multiple declarations of") <+> quotes (ppr name1),
+ ptext SLIT("Declared at:") <+> vcat (map ppr sorted_locs)]
where
- sorted_locs = sortLt occ'ed_before (map nameSrcLoc (n:ns))
- occ'ed_before a b = LT == compare a b
+ locs = map nameSrcLoc names
+ big_loc = foldr1 combineSrcSpans (map srcLocSpan locs)
+ name1 = head names
+ sorted_locs = sortLe (<=) (sortLe (<=) locs)
dupExportWarn occ_name ie1 ie2
= hsep [quotes (ppr occ_name),
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