%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[RnNames]{Extracting imported and top-level names in scope}
\begin{code}
-#include "HsVersions.h"
-
module RnNames (
- getGlobalNames
+ rnImports, importsFromLocalDecls, exportsFromAvail,
+ reportUnusedNames
) where
-IMP_Ubiq()
-
-import CmdLineOpts ( opt_SourceUnchanged )
-import HsSyn ( HsModule(..), HsDecl(..), FixityDecl(..), Fixity, Fake, InPat, IE(..), HsTyVar,
- TyDecl, ClassDecl, InstDecl, DefaultDecl, ImportDecl(..), HsBinds, IfaceSig
- )
-import HsBinds ( collectTopBinders )
-import HsImpExp ( ieName )
-import RdrHsSyn ( RdrNameHsDecl(..), RdrName(..), RdrNameIE(..), SYN_IE(RdrNameImportDecl),
- SYN_IE(RdrNameHsModule), SYN_IE(RdrNameFixityDecl),
- rdrNameOcc
- )
-import RnHsSyn ( RenamedHsModule(..), RenamedFixityDecl(..) )
-import RnIfaces ( getInterfaceExports, getDeclBinders, checkUpToDate )
+#include "HsVersions.h"
+
+import {-# SOURCE #-} RnHiFiles ( loadInterface )
+
+import CmdLineOpts ( DynFlag(..) )
+
+import HsSyn ( HsDecl(..), IE(..), ieName, ImportDecl(..),
+ ForeignDecl(..),
+ collectLocatedHsBinders, tyClDeclNames
+ )
+import RdrHsSyn ( RdrNameIE, RdrNameImportDecl, RdrNameHsDecl )
import RnEnv
-import RnMonad
+import TcRnMonad
+
import FiniteMap
-import PrelMods
-import UniqFM ( UniqFM, emptyUFM, addListToUFM_C, lookupUFM )
-import Bag ( Bag, bagToList )
-import Maybes ( maybeToBool, expectJust )
-import Name
-import Pretty
-import PprStyle ( PprStyle(..) )
-import Util ( panic, pprTrace )
+import PrelNames ( pRELUDE_Name, mAIN_Name, isBuiltInSyntaxName )
+import Module ( Module, ModuleName, moduleName,
+ moduleNameUserString,
+ unitModuleEnvByName, lookupModuleEnvByName,
+ moduleEnvElts )
+import Name ( Name, nameSrcLoc, nameOccName, nameModule )
+import NameSet
+import NameEnv
+import OccName ( OccName, dataName, isTcOcc )
+import HscTypes ( Provenance(..), ImportReason(..), GlobalRdrEnv,
+ GenAvailInfo(..), AvailInfo, Avails, IsBootInterface,
+ availName, availNames, availsToNameSet,
+ Deprecations(..), ModIface(..),
+ GlobalRdrElt(..), unQualInScope, isLocalGRE
+ )
+import RdrName ( rdrNameOcc, setRdrNameSpace, emptyRdrEnv, foldRdrEnv, isQual )
+import Outputable
+import Maybes ( maybeToBool, catMaybes )
+import ListSetOps ( removeDups )
+import Util ( sortLt, notNull )
+import List ( partition )
+import IO ( openFile, IOMode(..) )
\end{code}
%************************************************************************
%* *
-\subsection{Get global names}
+ rnImports
%* *
%************************************************************************
\begin{code}
-getGlobalNames :: RdrNameHsModule
- -> RnMG (Maybe (ExportEnv, RnEnv, [AvailInfo]))
- -- Nothing <=> no need to recompile
-
-getGlobalNames m@(HsModule this_mod _ exports imports _ _ mod_loc)
- = fixRn (\ ~(rec_exp_fn, _) ->
-
- -- PROCESS LOCAL DECLS
- -- Do these *first* so that the correct provenance gets
- -- into the global name cache.
- importsFromLocalDecls rec_exp_fn m `thenRn` \ (local_rn_env, local_mod_avails) ->
-
- -- PROCESS IMPORT DECLS
- mapAndUnzipRn importsFromImportDecl all_imports
- `thenRn` \ (imp_rn_envs, imp_avails_s) ->
-
- -- CHECK FOR EARLY EXIT
- checkEarlyExit this_mod `thenRn` \ early_exit ->
- if early_exit then
- returnRn (junk_exp_fn, Nothing)
- else
-
- -- COMBINE RESULTS
- -- We put the local env first, so that a local provenance
- -- "wins", even if a module imports itself.
- foldlRn plusRnEnv emptyRnEnv imp_rn_envs `thenRn` \ imp_rn_env ->
- plusRnEnv local_rn_env imp_rn_env `thenRn` \ rn_env ->
- let
- all_avails :: ModuleAvails
- all_avails = foldr plusModuleAvails local_mod_avails imp_avails_s
- local_avails = expectJust "getGlobalNames" (lookupModuleAvails local_mod_avails this_mod)
- in
-
- -- PROCESS EXPORT LISTS
- exportsFromAvail this_mod exports all_avails rn_env
- `thenRn` \ (export_fn, export_env) ->
-
- returnRn (export_fn, Just (export_env, rn_env, local_avails))
- ) `thenRn` \ (_, result) ->
- returnRn result
+rnImports :: [RdrNameImportDecl]
+ -> TcRn m (GlobalRdrEnv, ImportAvails)
+
+rnImports imports
+ = -- 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 (moduleName this_mod)
+ in
+ mappM get_imports ordinary `thenM` \ stuff1 ->
+ mappM get_imports source `thenM` \ stuff2 ->
+
+ -- COMBINE RESULTS
+ let
+ (imp_gbl_envs, imp_avails) = unzip (stuff1 ++ stuff2)
+ gbl_env :: GlobalRdrEnv
+ gbl_env = foldr plusGlobalRdrEnv emptyRdrEnv imp_gbl_envs
+
+ all_avails :: ImportAvails
+ all_avails = foldr plusImportAvails emptyImportAvails imp_avails
+ in
+ -- ALL DONE
+ returnM (gbl_env, all_avails)
where
- junk_exp_fn = error "RnNames:export_fn"
-
- all_imports = prel_imports ++ imports
+ -- 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
+ || explicit_prelude_import
+ || no_prelude
+ = []
- prel_imports | this_mod == pRELUDE ||
- explicit_prelude_import = []
+ | otherwise = [preludeImportDecl loc]
- | otherwise = [ImportDecl pRELUDE
- False {- Not qualified -}
- Nothing {- No "as" -}
- Nothing {- No import list -}
- mod_loc]
-
explicit_prelude_import
- = not (null [ () | (ImportDecl mod qual _ _ _) <- imports, mod == pRELUDE ])
+ = notNull [ () | (ImportDecl mod _ _ _ _ _) <- imports,
+ mod == pRELUDE_Name ]
+
+preludeImportDecl loc
+ = ImportDecl pRELUDE_Name
+ False {- Not a boot interface -}
+ False {- Not qualified -}
+ Nothing {- No "as" -}
+ Nothing {- No import list -}
+ loc
\end{code}
\begin{code}
-checkEarlyExit mod
- = if not opt_SourceUnchanged then
- -- Source code changed; look no further
- returnRn False
- else
- -- Unchanged source; look further
- -- We check for
- -- (a) errors so far. These can arise if a module imports
- -- something that's no longer exported by the imported module
- -- (b) usage information up to date
- checkErrsRn `thenRn` \ no_errs_so_far ->
- checkUpToDate mod `thenRn` \ up_to_date ->
- returnRn (no_errs_so_far && up_to_date)
-\end{code}
-
+importsFromImportDecl :: ModuleName
+ -> RdrNameImportDecl
+ -> TcRn m (GlobalRdrEnv, ImportAvails)
-\begin{code}
-importsFromImportDecl :: RdrNameImportDecl
- -> RnMG (RnEnv, ModuleAvails)
-
- -- Check for "import M ()", and then don't even look at M.
- -- This makes sense, and is actually rather useful for the Prelude.
-importsFromImportDecl (ImportDecl mod qual as_mod (Just (False,[])) loc)
- = returnRn (emptyRnEnv, emptyModuleAvails)
-
-importsFromImportDecl (ImportDecl mod qual as_mod import_spec loc)
- = pushSrcLocRn loc $
- getInterfaceExports mod `thenRn` \ (avails, fixities) ->
- filterImports mod import_spec avails `thenRn` \ filtered_avails ->
+importsFromImportDecl this_mod_name
+ (ImportDecl imp_mod_name is_boot qual_only as_mod import_spec iloc)
+ = addSrcLoc iloc $
let
- filtered_avails' = [ Avail (set_name_prov n) (map set_name_prov ns)
- | Avail n ns <- filtered_avails
- ]
- fixities' = [ (occ,fixity,provenance) | (occ,fixity) <- fixities ]
+ doc = ppr imp_mod_name <+> ptext SLIT("is directly imported")
in
- qualifyImports mod qual as_mod (ExportEnv filtered_avails' fixities')
- where
- set_name_prov name = setNameProvenance name provenance
- provenance = Imported mod loc
-\end{code}
+ -- If there's an error in loadInterface, (e.g. interface
+ -- file not found) we get lots of spurious errors from 'filterImports'
+ recoverM (returnM Nothing)
+ (loadInterface doc imp_mod_name (ImportByUser is_boot) `thenM` \ iface ->
+ returnM (Just iface)) `thenM` \ mb_iface ->
-\begin{code}
-importsFromLocalDecls rec_exp_fn (HsModule mod _ _ _ fix_decls decls _)
- = foldlRn getLocalDeclBinders [] decls `thenRn` \ avails ->
- mapRn fixityFromFixDecl fix_decls `thenRn` \ fixities ->
- qualifyImports mod
- False -- Not qualified
- Nothing -- No "as M" part
- (ExportEnv avails fixities)
- where
- newLocalName rdr_name loc
- = newLocallyDefinedGlobalName mod (rdrNameOcc rdr_name) rec_exp_fn loc
+ case mb_iface of {
+ Nothing -> returnM (emptyRdrEnv, emptyImportAvails ) ;
+ Just iface ->
- getLocalDeclBinders avails (ValD binds)
- = mapRn do_one (bagToList (collectTopBinders binds)) `thenRn` \ val_avails ->
- returnRn (val_avails ++ avails)
+ let
+ imp_mod = mi_module iface
+ avails_by_module = mi_exports iface
+ deprecs = mi_deprecs iface
+ dir_imp = unitModuleEnvByName imp_mod_name (imp_mod, import_all import_spec)
+
+ avails :: Avails
+ avails = [ avail | (mod_name, avails) <- avails_by_module,
+ mod_name /= this_mod_name,
+ avail <- avails ]
+ -- If the module exports anything defined in this module, just ignore it.
+ -- Reason: otherwise it looks as if there are two local definition sites
+ -- for the thing, and an error gets reported. Easiest thing is just to
+ -- filter them out up front. This situation only arises if a module
+ -- imports itself, or another module that imported it. (Necessarily,
+ -- this invoves a loop.)
+ --
+ -- Tiresome consequence: if you say
+ -- module A where
+ -- import B( AType )
+ -- type AType = ...
+ --
+ -- module B( AType ) where
+ -- import {-# SOURCE #-} A( AType )
+ --
+ -- then you'll get a 'B does not export AType' message. Oh well.
- getLocalDeclBinders avails decl
- = getDeclBinders newLocalName decl `thenRn` \ avail ->
- returnRn (avail : avails)
+ 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_`
+
+ -- Filter the imports according to the import list
+ filterImports imp_mod_name is_boot import_spec avails `thenM` \ (filtered_avails, explicits) ->
+
+ let
+ unqual_imp = not qual_only -- Maybe want unqualified names
+ qual_mod = case as_mod of
+ Nothing -> imp_mod_name
+ Just another_name -> another_name
+
+ mk_prov name = NonLocalDef (UserImport imp_mod iloc (name `elemNameSet` explicits))
+ gbl_env = mkGlobalRdrEnv qual_mod unqual_imp mk_prov filtered_avails deprecs
+ imports = mkImportAvails qual_mod unqual_imp gbl_env filtered_avails
+ in
+ returnM (gbl_env, imports { imp_mods = dir_imp})
+ }
- do_one (rdr_name, loc)
- = newLocalName rdr_name loc `thenRn` \ name ->
- returnRn (Avail name [])
+import_all (Just (False, _)) = False -- Imports are spec'd explicitly
+import_all other = True -- Everything is imported
\end{code}
+
%************************************************************************
%* *
-\subsection{Filtering imports}
+ importsFromLocalDecls
%* *
%************************************************************************
-@filterImports@ takes the @ExportEnv@ telling what the imported module makes
-available, and filters it through the import spec (if any).
+From the top-level declarations of this module produce
+ * the lexical environment
+ * the ImportAvails
+created by its bindings.
+
+Complain about duplicate bindings
\begin{code}
-filterImports :: Module
- -> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hidin
- -> [AvailInfo] -- What's available
- -> RnMG [AvailInfo] -- What's actually imported
- -- Complains if import spec mentions things the
- -- module doesn't export
-
-filterImports mod Nothing imports
- = returnRn imports
+importsFromLocalDecls :: [RdrNameHsDecl]
+ -> TcRn m (GlobalRdrEnv, ImportAvails)
+importsFromLocalDecls decls
+ = getModule `thenM` \ this_mod ->
+ mappM (getLocalDeclBinders this_mod) decls `thenM` \ avails_s ->
+ -- The avails that are returned don't include the "system" names
+ let
+ avails = concat avails_s
-filterImports mod (Just (want_hiding, import_items)) avails
- = -- Check that each import item mentions things that are actually available
- mapRn check_import_item import_items `thenRn_`
+ all_names :: [Name] -- All the defns; no dups eliminated
+ all_names = [name | avail <- avails, name <- availNames avail]
- -- Return filtered environment; no need to filter fixities
- returnRn (map new_avail avails)
+ 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_ (addErr . dupDeclErr) dups `thenM_`
- where
- import_fm :: FiniteMap OccName RdrNameIE
- import_fm = listToFM [(ieOcc ie, ie) | ie <- import_items]
-
- avail_fm :: FiniteMap OccName AvailInfo
- avail_fm = listToFM [(nameOccName name, avail) | avail@(Avail name ns) <- avails]
-
- new_avail NotAvailable = NotAvailable
- new_avail avail@(Avail name _)
- | not in_import_items && want_hiding = avail
- | not in_import_items && not want_hiding = NotAvailable
- | in_import_items && want_hiding = NotAvailable
- | in_import_items && not want_hiding = filtered_avail
- where
- maybe_import_item = lookupFM import_fm (nameOccName name)
- in_import_items = maybeToBool maybe_import_item
- Just import_item = maybe_import_item
- filtered_avail = filterAvail import_item avail
-
- check_import_item :: RdrNameIE -> RnMG ()
- check_import_item item
- = checkRn (maybeToBool maybe_matching_avail && sub_names_ok item avail)
- (badImportItemErr mod item)
- where
- item_name = ieOcc item
- maybe_matching_avail = lookupFM avail_fm item_name
- Just avail = maybe_matching_avail
-
- sub_names_ok (IEVar _) _ = True
- sub_names_ok (IEThingAbs _) _ = True
- sub_names_ok (IEThingAll _) _ = True
- sub_names_ok (IEThingWith _ wanted) (Avail _ has) = all ((`elem` has_list) . rdrNameOcc) wanted
- where
- has_list = map nameOccName has
- sub_names_ok other1 other2 = False
+ doptM Opt_NoImplicitPrelude `thenM` \ implicit_prelude ->
+ let
+ mod_name = moduleName this_mod
+ unqual_imp = True -- Want unqualified names
+ mk_prov n = LocalDef -- Provenance is local
+
+ 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
+
+
+ -- 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
+ -- envt is no use. To avoid doing this filter all the type,
+ -- we use -fno-implicit-prelude as a clue that the filter is
+ -- worth while. Really, it's only useful for Base and Tuple.
+ --
+ -- 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
+ -- 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.
+ -- The important thing is to trim down the exports.
+ imports = mkImportAvails mod_name unqual_imp gbl_env avails'
+ 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.
+ in
+ returnM (gbl_env, imports)
\end{code}
+%*********************************************************
+%* *
+\subsection{Getting binders out of a declaration}
+%* *
+%*********************************************************
-%************************************************************************
-%* *
-\subsection{Qualifiying imports}
-%* *
-%************************************************************************
+@getLocalDeclBinders@ returns the names for a @RdrNameHsDecl@. It's
+used for both source code (from @importsFromLocalDecls@) and interface
+files (@loadDecl@ calls @getTyClDeclBinders@).
-@qualifyImports@ takes the @ExportEnv@ after filtering through the import spec
-of an import decl, and deals with producing an @RnEnv@ with the
-right qaulified names. It also turns the @Names@ in the @ExportEnv@ into
-fully fledged @Names@.
+ *** See "THE NAMING STORY" in HsDecls ****
\begin{code}
-qualifyImports :: Module -- Improrted module
- -> Bool -- True <=> qualified import
- -> Maybe Module -- Optional "as M" part
- -> ExportEnv -- What's imported
- -> RnMG (RnEnv, ModuleAvails)
-
-qualifyImports this_mod qual as_mod (ExportEnv avails fixities)
- = -- Make the qualified-name environments, checking of course for clashes
- foldlRn add_name emptyNameEnv avails `thenRn` \ name_env ->
- foldlRn (add_fixity name_env) emptyFixityEnv fixities `thenRn` \ fixity_env ->
-
- -- Deal with the "qualified" part; if not qualifies then add unqualfied bindings
- if qual then
- returnRn (RnEnv name_env fixity_env, mod_avail_env)
- else
- returnRn (RnEnv (unQualify name_env) (unQualify fixity_env), mod_avail_env)
-
+getLocalDeclBinders :: Module -> RdrNameHsDecl -> TcRn m [AvailInfo]
+getLocalDeclBinders mod (TyClD tycl_decl)
+ = -- 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.
+ mapM new (tyClDeclNames tycl_decl) `thenM` \ names@(main_name:_) ->
+ returnM [AvailTC main_name names]
where
- mod_avail_env = unitFM this_mod avails
-
- add_name name_env NotAvailable = returnRn name_env
- add_name name_env (Avail n ns) = foldlRn add_one name_env (n : ns)
-
- add_one :: NameEnv -> Name -> RnMG NameEnv
- add_one env name = addOneToNameEnvRn env (Qual this_mod occ_name) name
- where
- occ_name = nameOccName name
+ new (nm,loc) = newTopBinder mod nm loc
- add_fixity name_env fixity_env (occ_name, fixity, provenance)
- | maybeToBool (lookupFM name_env qual_name) -- The name is imported
- = addOneToFixityEnvRn fixity_env qual_name (fixity,provenance)
- | otherwise -- It ain't imported
- = returnRn fixity_env
- where
- qual_name = Qual this_mod occ_name
+getLocalDeclBinders mod (ValD binds)
+ = mappM new (collectLocatedHsBinders binds) `thenM` \ avails ->
+ returnM avails
+ where
+ new (rdr_name, loc) = newTopBinder mod rdr_name loc `thenM` \ name ->
+ returnM (Avail name)
+
+getLocalDeclBinders mod (ForD (ForeignImport nm _ _ _ loc))
+ = newTopBinder mod nm loc `thenM` \ name ->
+ returnM [Avail name]
+getLocalDeclBinders mod (ForD _)
+ = returnM []
+
+getLocalDeclBinders mod (FixD _) = returnM []
+getLocalDeclBinders mod (DeprecD _) = returnM []
+getLocalDeclBinders mod (DefD _) = returnM []
+getLocalDeclBinders mod (InstD _) = returnM []
+getLocalDeclBinders mod (RuleD _) = returnM []
\end{code}
-unQualify adds an Unqual binding for every existing Qual binding.
-
-\begin{code}
-unQualify :: FiniteMap RdrName elt -> FiniteMap RdrName elt
-unQualify fm = addListToFM fm [(Unqual occ, elt) | (Qual _ occ, elt) <- fmToList fm]
-\end{code}
%************************************************************************
%* *
-\subsection{Local declarations}
+\subsection{Filtering imports}
%* *
%************************************************************************
+@filterImports@ takes the @ExportEnv@ telling what the imported module makes
+available, and filters it through the import spec (if any).
\begin{code}
-fixityFromFixDecl :: RdrNameFixityDecl -> RnMG (OccName, Fixity, Provenance)
+filterImports :: ModuleName -- 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
+
+ -- 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)
+
+filterImports mod from (Just (want_hiding, import_items)) total_avails
+ = mappM get_item import_items `thenM` \ avails_w_explicits_s ->
+ let
+ (item_avails, explicits_s) = unzip (concat avails_w_explicits_s)
+ explicits = foldl addListToNameSet emptyNameSet explicits_s
+ 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)
+ else
+ -- Just item_avails imported; nothing to be hidden
+ returnM (item_avails, explicits)
+ 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,
+ -- 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_`
+ returnM []
+
+ get_item :: RdrNameIE -> TcRn m [(AvailInfo, [Name])]
+ -- Empty list for a bad item.
+ -- Singleton 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@(IEThingAll _)
+ = 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])]
+
+ 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
+ where
+ data_n = setRdrNameSpace n dataName
+
+ get_item item
+ = case check_item item of
+ Nothing -> bale_out item
+ Just avail -> returnM [(avail, availNames avail)]
+
+ check_item item
+ | not (maybeToBool maybe_in_import_avails) ||
+ not (maybeToBool 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}
-fixityFromFixDecl (FixityDecl rdr_name fixity loc)
- = returnRn (rdrNameOcc rdr_name, fixity, LocalDef (panic "export-flag") loc)
+\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
\end{code}
%************************************************************************
%* *
-\subsection{Export list processing
+\subsection{Export list processing}
%* *
%************************************************************************
-The @AvailEnv@ type is just used internally in @exportsFromAvail@.
-When exporting we need to combine the availabilities for a particular
-exported thing, and we also need to check for name clashes -- that
-is: two exported things must have different @OccNames@.
-
-\begin{code}
-type AvailEnv = FiniteMap OccName (RdrNameIE, AvailInfo)
- -- The FM maps each OccName to the RdrNameIE that gave rise to it,
- -- for error reporting, as well as to its AvailInfo
-
-emptyAvailEnv = emptyFM
-
-unitAvailEnv :: RdrNameIE -> AvailInfo -> AvailEnv
-unitAvailEnv ie NotAvailable
- = emptyFM
-unitAvailEnv ie avail@(Avail n ns)
- = unitFM (nameOccName n) (ie,avail)
+Processing the export list.
-plusAvailEnv a1 a2
- = mapRn (addErrRn.availClashErr) (conflictsFM bad_avail a1 a2) `thenRn_`
- returnRn (plusFM_C plus_avail a1 a2)
-
-listToAvailEnv :: RdrNameIE -> [AvailInfo] -> RnM s d AvailEnv
-listToAvailEnv ie items
- = foldlRn plusAvailEnv emptyAvailEnv (map (unitAvailEnv ie) items)
-
-bad_avail (ie1,Avail n1 _) (ie2,Avail n2 _) = n1 /= n2 -- Same OccName, different Name
-plus_avail (ie1,a1) (ie2,a2) = (ie1, a1 `plusAvail` a2)
-\end{code}
+You might think that we should record things that appear in the export
+list as ``occurrences'' (using @addOccurrenceName@), but you'd be
+wrong. We do check (here) that they are in scope, but there is no
+need to slurp in their actual declaration (which is what
+@addOccurrenceName@ forces).
+Indeed, doing so would big trouble when compiling @PrelBase@, because
+it re-exports @GHC@, which includes @takeMVar#@, whose type includes
+@ConcBase.StateAndSynchVar#@, and so on...
\begin{code}
-exportsFromAvail :: Module
- -> Maybe [RdrNameIE] -- Export spec
- -> ModuleAvails
- -> RnEnv
- -> RnMG (Name -> ExportFlag, ExportEnv)
+type ExportAccum -- The type of the accumulating parameter of
+ -- the main worker function in exportsFromAvail
+ = ([ModuleName], -- '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)
+
+type ExportOccMap = FiniteMap OccName (Name, RdrNameIE)
+ -- 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
-- Complains if two distinct exports have same OccName
+ -- Warns about identical exports.
-- Complains about exports items not in scope
-exportsFromAvail this_mod Nothing all_avails rn_env
- = exportsFromAvail this_mod (Just [IEModuleContents this_mod]) all_avails rn_env
-
-exportsFromAvail this_mod (Just export_items) all_avails (RnEnv name_env fixity_env)
- = mapRn exports_from_item export_items `thenRn` \ avail_envs ->
- foldlRn plusAvailEnv emptyAvailEnv avail_envs `thenRn` \ export_avail_env ->
- let
- export_avails = map snd (eltsFM export_avail_env)
- export_fixities = mk_exported_fixities (availsToNameSet export_avails)
- export_fn = mk_export_fn export_avails
- in
- returnRn (export_fn, ExportEnv export_avails export_fixities)
+exportsFromAvail Nothing
+ = do { this_mod <- getModule ;
+ if moduleName this_mod == mAIN_Name then
+ return []
+ -- Export nothing; Main.$main is automatically exported
+ else
+ exportsFromAvail (Just [IEModuleContents (moduleName this_mod)])
+ -- but for all other modules export everything.
+ }
+
+exportsFromAvail (Just exports)
+ = do { TcGblEnv { tcg_imports = imports } <- getGblEnv ;
+ warn_dup_exports <- doptM Opt_WarnDuplicateExports ;
+ exports_from_avail exports warn_dup_exports imports }
+
+exports_from_avail export_items warn_dup_exports
+ (ImportAvails { imp_unqual = mod_avail_env,
+ imp_env = entity_avail_env })
+ = foldlM exports_from_item emptyExportAccum
+ export_items `thenM` \ (_, _, export_avail_map) ->
+ returnM (nameEnvElts export_avail_map)
where
- full_avail_env :: UniqFM AvailInfo
- full_avail_env = addListToUFM_C plusAvail emptyUFM
- [(name,avail) | avail@(Avail name _) <- concat (eltsFM all_avails)]
- -- NB: full_avail_env won't contain bindings for data constructors and class ops,
- -- which is right and proper; attempts to export them on their own will provoke an error
-
- exports_from_item :: RdrNameIE -> RnMG AvailEnv
- exports_from_item ie@(IEModuleContents mod)
- = case lookupFM all_avails mod of
- Nothing -> failWithRn emptyAvailEnv (modExportErr mod)
- Just avails -> addOccurrenceNames Compulsory [n | Avail n _ <- avails] `thenRn_`
- listToAvailEnv ie avails
-
- exports_from_item ie
- | not (maybeToBool maybe_in_scope)
- = failWithRn emptyAvailEnv (unknownNameErr (ieName ie))
-
-#ifdef DEBUG
- -- I can't see why this should ever happen; if the thing is in scope
- -- at all it ought to have some availability
- | not (maybeToBool maybe_avail)
- = pprTrace "exportsFromAvail: curious Nothing:" (ppr PprDebug name)
- returnRn emptyAvailEnv
-#endif
-
- | not enough_avail
- = failWithRn emptyAvailEnv (exportItemErr ie export_avail)
-
- | otherwise -- Phew! It's OK!
- = addOccurrenceName Compulsory name `thenRn_`
- returnRn (unitAvailEnv ie export_avail)
- where
- maybe_in_scope = lookupNameEnv name_env (ieName ie)
- Just name = maybe_in_scope
- maybe_avail = lookupUFM full_avail_env name
- Just avail = maybe_avail
- export_avail = filterAvail ie avail
- enough_avail = case export_avail of {NotAvailable -> False; other -> True}
-
- -- We export a fixity iff we export a thing with the same (qualified) RdrName
- mk_exported_fixities :: NameSet -> [(OccName, Fixity, Provenance)]
- mk_exported_fixities exports
- = [ (rdrNameOcc rdr_name, fixity, prov)
- | (rdr_name, (fixity, prov)) <- fmToList fixity_env,
- export_fixity name_env exports rdr_name
- ]
-
-mk_export_fn :: [AvailInfo] -> (Name -> ExportFlag)
-mk_export_fn avails
- = \name -> if name `elemNameSet` exported_names
- then Exported
- else NotExported
+ exports_from_item :: ExportAccum -> RdrNameIE -> TcRn m ExportAccum
+
+ exports_from_item acc@(mods, occs, avails) ie@(IEModuleContents mod)
+ | mod `elem` mods -- Duplicate export of M
+ = warnIf warn_dup_exports (dupModuleExport mod) `thenM_`
+ returnM acc
+
+ | otherwise
+ = case lookupModuleEnvByName mod_avail_env mod of
+ Nothing -> addErr (modExportErr mod) `thenM_`
+ returnM acc
+ Just mod_avails
+ -> foldlM (check_occs warn_dup_exports ie)
+ occs mod_avails `thenM` \ occs' ->
+ let
+ avails' = foldl addAvail avails mod_avails
+ in
+ 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
+ case lookupAvailEnv entity_avail_env (gre_parent gre) of {
+ Nothing -> pprPanic "exportsFromAvail"
+ ((ppr (ieName ie)) <+> ppr gre) ;
+ Just avail ->
+
+ -- 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 warn_dup_exports ie occs export_avail `thenM` \ occs' ->
+ returnM (mods, occs', addAvail avails export_avail)
+ }}}
+
+
+
+ok_item (IEThingAll _) (AvailTC _ [n]) = False
+ -- This occurs when you import T(..), but
+ -- only export T abstractly. The single [n]
+ -- in the AvailTC is the type or class itself
+ok_item _ _ = True
+
+check_occs :: Bool -> RdrNameIE -> ExportOccMap -> AvailInfo -> TcRn m ExportOccMap
+check_occs warn_dup_exports ie occs avail
+ = foldlM check occs (availNames avail)
where
- exported_names :: NameSet
- exported_names = availsToNameSet avails
+ check occs name
+ = case lookupFM occs name_occ of
+ Nothing -> returnM (addToFM occs name_occ (name, ie))
+ Just (name', ie')
+ | name == name' -> -- Duplicate export
+ warnIf warn_dup_exports
+ (dupExportWarn name_occ ie ie')
+ `thenM_` returnM occs
+
+ | otherwise -> -- Same occ name but different names: an error
+ addErr (exportClashErr name_occ ie ie') `thenM_`
+ returnM occs
+ where
+ name_occ = nameOccName name
+\end{code}
+
+%*********************************************************
+%* *
+\subsection{Unused names}
+%* *
+%*********************************************************
-export_fixity :: NameEnv -> NameSet -> RdrName -> Bool
-export_fixity name_env exports (Unqual _)
- = False -- The qualified fixity is always there as well
-export_fixity name_env exports rdr_name@(Qual _ occ)
- = case lookupFM name_env rdr_name of
- Just fixity_name -> fixity_name `elemNameSet` exports
- -- Check whether the exported thing is
- -- the one to which the fixity attaches
- other -> False -- Not even in scope
-\end{code}
+\begin{code}
+reportUnusedNames :: TcGblEnv
+ -> NameSet -- Used in this module
+ -> TcRn m ()
+reportUnusedNames gbl_env used_names
+ = warnUnusedModules unused_imp_mods `thenM_`
+ warnUnusedTopBinds bad_locals `thenM_`
+ warnUnusedImports bad_imports `thenM_`
+ printMinimalImports minimal_imports
+ where
+ direct_import_mods :: [ModuleName]
+ direct_import_mods = map (moduleName . fst)
+ (moduleEnvElts (imp_mods (tcg_imports gbl_env)))
+
+ -- Now, a use of C implies a use of T,
+ -- if C was brought into scope by T(..) or T(C)
+ really_used_names :: NameSet
+ really_used_names = used_names `unionNameSets`
+ mkNameSet [ gre_parent gre
+ | gre <- defined_names,
+ gre_name gre `elemNameSet` used_names]
+
+ -- 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_and_used, defined_but_not_used :: [GlobalRdrElt]
+ (defined_and_used, defined_but_not_used) = partition used defined_names
+ used gre = gre_name gre `elemNameSet` really_used_names
+
+ -- Filter out the ones only defined implicitly
+ bad_locals :: [GlobalRdrElt]
+ bad_locals = filter isLocalGRE defined_but_not_used
+
+ 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
+
+ -- 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
+ 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
+ -- even if we import nothing explicitly.
+ -- It's not necessarily redundant to import such modules. Consider
+ -- module This
+ -- import M ()
+ --
+ -- The import M() is not *necessarily* redundant, even if
+ -- we suck in no instance decls from M (e.g. it contains
+ -- no instance decls, or This contains no code). It may be
+ -- that we import M solely to ensure that M's orphan instance
+ -- decls (or those in its imports) are visible to people who
+ -- import This. Sigh.
+ -- 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 other acc
+ = acc
+
+ -- n is the name of the thing, p is the name of its parent
+ mk_avail n p | n/=p = AvailTC p [p,n]
+ | isTcOcc (nameOccName p) = 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 an empty collection of imports for a module
+ -- from which we have sucked only instance decls
+
+ -- unused_imp_mods are the directly-imported modules
+ -- that are not mentioned in minimal_imports1
+ -- [Note: not 'minimal_imports', because that includes direcly-imported
+ -- modules even if we use nothing from them; see notes above]
+ unused_imp_mods = [m | m <- direct_import_mods,
+ not (maybeToBool (lookupFM minimal_imports1 m)),
+ m /= pRELUDE_Name]
+
+ module_unused :: Module -> Bool
+ module_unused mod = moduleName mod `elem` unused_imp_mods
+
+
+-- ToDo: deal with original imports with 'qualified' and 'as M' clauses
+printMinimalImports :: FiniteMap ModuleName AvailEnv -- Minimal imports
+ -> TcRn m ()
+printMinimalImports imps
+ = ifOptM Opt_D_dump_minimal_imports $ do {
+
+ mod_ies <- mappM to_ies (fmToList imps) ;
+ this_mod <- getModule ;
+ rdr_env <- getGlobalRdrEnv ;
+ ioToTcRn (do { h <- openFile (mkFilename this_mod) WriteMode ;
+ printForUser h (unQualInScope rdr_env)
+ (vcat (map ppr_mod_ie mod_ies)) })
+ }
+ where
+ mkFilename this_mod = moduleNameUserString (moduleName this_mod) ++ ".imports"
+ ppr_mod_ie (mod_name, ies)
+ | mod_name == pRELUDE_Name
+ = empty
+ | null ies -- Nothing except instances comes from here
+ = ptext SLIT("import") <+> ppr mod_name <> ptext SLIT("() -- Instances only")
+ | otherwise
+ = 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_ie :: AvailInfo -> TcRn m (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 (Avail n) = returnM (IEVar n)
+ 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 ->
+ 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)
+ where
+ n_mod = moduleName (nameModule n)
+\end{code}
%************************************************************************
%************************************************************************
\begin{code}
-ieOcc ie = rdrNameOcc (ieName ie)
-
-badImportItemErr mod ie sty
- = ppSep [ppStr "Module", pprModule sty mod, ppStr "does not export", ppr sty ie]
-
-modExportErr mod sty
- = ppCat [ ppStr "Unknown module in export list: module", ppPStr mod]
-
-exportItemErr export_item NotAvailable sty
- = ppSep [ ppStr "Export item not in scope:", ppr sty export_item ]
-
-exportItemErr export_item avail sty
- = ppHang (ppStr "Export item not fully in scope:")
- 4 (ppAboves [ppCat [ppStr "Wanted: ", ppr sty export_item],
- ppCat [ppStr "Available: ", ppr sty (ieOcc export_item), pprAvail sty avail]])
-
-availClashErr (occ_name, ((ie1,avail1), (ie2,avail2))) sty
- = ppHang (ppCat [ppStr "Conflicting exports for local name: ", ppr sty occ_name])
- 4 (ppAboves [ppr sty ie1, ppr sty ie2])
+badImportItemErr mod from ie
+ = sep [ptext SLIT("Module"), quotes (ppr mod), source_import,
+ ptext SLIT("does not export"), quotes (ppr ie)]
+ where
+ source_import = case from of
+ True -> ptext SLIT("(hi-boot interface)")
+ other -> empty
+
+dodgyImportWarn mod 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),
+ 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") ]
+
+modExportErr mod
+ = hsep [ ptext SLIT("Unknown module in export list: module"), quotes (ppr mod)]
+
+exportItemErr 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") ]
+
+exportClashErr occ_name ie1 ie2
+ = hsep [ptext SLIT("The export items"), quotes (ppr ie1)
+ ,ptext SLIT("and"), quotes (ppr ie2)
+ ,ptext SLIT("create conflicting exports for"), quotes (ppr occ_name)]
+
+dupDeclErr (n:ns)
+ = vcat [ptext SLIT("Multiple declarations of") <+> quotes (ppr n),
+ nest 4 (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
+
+dupExportWarn occ_name ie1 ie2
+ = hsep [quotes (ppr occ_name),
+ ptext SLIT("is exported by"), quotes (ppr ie1),
+ ptext SLIT("and"), quotes (ppr ie2)]
+
+dupModuleExport mod
+ = hsep [ptext SLIT("Duplicate"),
+ quotes (ptext SLIT("Module") <+> ppr mod),
+ ptext SLIT("in export list")]
+
+moduleDeprec mod txt
+ = sep [ ptext SLIT("Module") <+> quotes (ppr mod) <+> ptext SLIT("is deprecated:"),
+ nest 4 (ppr txt) ]
\end{code}
-