%
-% (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,
- GlobalNameInfo(..)
+ rnImports, importsFromLocalDecls, exportsFromAvail,
+ reportUnusedNames
) where
-import PreludeGlaST ( returnPrimIO, thenPrimIO, MutableVar(..) )
-
-import Ubiq
-
-import HsSyn
-import RdrHsSyn
-import RnHsSyn
-
-import RnMonad
-import RnIfaces ( IfaceCache(..), cacheInterface, ParsedIface )
-import RnUtils ( RnEnv(..), emptyRnEnv, extendGlobalRnEnv, qualNameErr, dupNamesErr )
-
-import Bag ( emptyBag, unitBag, unionBags, unionManyBags, mapBag, listToBag, bagToList )
-import ErrUtils ( Error(..), Warning(..), addShortErrLocLine )
-import FiniteMap ( fmToList )
-import Name ( RdrName(..), isQual, mkTopLevName, mkImportedName, nameExportFlag, Name )
-import Outputable ( getLocalName, getSrcLoc, pprNonOp )
-import PrelInfo ( BuiltinNames(..), BuiltinKeys(..) )
-import PrelMods ( fromPrelude )
-import Pretty
-import SrcLoc ( SrcLoc )
-import UniqSupply ( splitUniqSupply )
-import Util ( equivClasses, panic )
+#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 TcRnMonad
+
+import FiniteMap
+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}
+
+%************************************************************************
+%* *
+ rnImports
+%* *
+%************************************************************************
+
+\begin{code}
+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
+ -- 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
+ = []
+
+ | otherwise = [preludeImportDecl loc]
+
+ explicit_prelude_import
+ = 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}
-type GlobalNameInfo = (BuiltinNames,
- BuiltinKeys,
- Name -> ExportFlag,
- Name -> [RdrName])
-
-type RnM_Info s r = RnMonad GlobalNameInfo s r
-
-getGlobalNames ::
- IfaceCache
- -> GlobalNameInfo
- -> UniqSupply
- -> RdrNameHsModule
- -> PrimIO (RnEnv,
- [Module],
- Bag RenamedFixityDecl,
- Bag Error,
- Bag Warning)
-
-getGlobalNames iface_var info us
- (HsModule mod _ _ imports _ ty_decls _ cls_decls _ _ _ binds _ _)
- = case initRn True mod emptyRnEnv us1
- (setExtraRn info $
- getSourceNames ty_decls cls_decls binds)
- of { ((src_vals, src_tcs), src_errs, src_warns) ->
-
- getImportedNames iface_var info us2 imports `thenPrimIO`
- \ (imp_vals, imp_tcs, imp_mods, imp_fixes, imp_errs, imp_warns) ->
+importsFromImportDecl :: ModuleName
+ -> RdrNameImportDecl
+ -> TcRn m (GlobalRdrEnv, ImportAvails)
+importsFromImportDecl this_mod_name
+ (ImportDecl imp_mod_name is_boot qual_only as_mod import_spec iloc)
+ = addSrcLoc iloc $
let
- unqual_vals = mapBag (\rn -> (Unqual (getLocalName rn), rn)) src_vals
- unqual_tcs = mapBag (\rn -> (Unqual (getLocalName rn), rn)) src_tcs
+ doc = ppr imp_mod_name <+> ptext SLIT("is directly imported")
+ in
+
+ -- 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 ->
- all_vals = bagToList (unqual_vals `unionBags` imp_vals)
- all_tcs = bagToList (unqual_tcs `unionBags` imp_tcs)
+ case mb_iface of {
+ Nothing -> returnM (emptyRdrEnv, emptyImportAvails ) ;
+ Just iface ->
- (all_env, dups) = extendGlobalRnEnv emptyRnEnv all_vals all_tcs
+ 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.
+
+ 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_`
- dup_errs = map dup_err (equivClasses cmp_rdr (bagToList dups))
- cmp_rdr (rdr1,_,_) (rdr2,_,_) = cmp rdr1 rdr2
- dup_err ((rdr,rn,rn'):rest) = globalDupNamesErr rdr (rn:rn': [rn|(_,_,rn)<-rest])
+ -- Filter the imports according to the import list
+ filterImports imp_mod_name is_boot import_spec avails `thenM` \ (filtered_avails, explicits) ->
- all_errs = src_errs `unionBags` imp_errs `unionBags` listToBag dup_errs
- all_warns = src_warns `unionBags` imp_warns
+ 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
- returnPrimIO (all_env, bagToList imp_mods, imp_fixes, all_errs, all_warns)
+ returnM (gbl_env, imports { imp_mods = dir_imp})
}
- where
- (us1, us2) = splitUniqSupply us
+
+import_all (Just (False, _)) = False -- Imports are spec'd explicitly
+import_all other = True -- Everything is imported
\end{code}
-*********************************************************
-* *
-\subsection{Top-level source names}
-* *
-*********************************************************
+
+%************************************************************************
+%* *
+ importsFromLocalDecls
+%* *
+%************************************************************************
+
+From the top-level declarations of this module produce
+ * the lexical environment
+ * the ImportAvails
+created by its bindings.
+
+Complain about duplicate bindings
\begin{code}
-getSourceNames ::
- [RdrNameTyDecl]
- -> [RdrNameClassDecl]
- -> RdrNameHsBinds
- -> RnM_Info s (Bag RnName, -- values
- Bag RnName) -- tycons/classes
-
-getSourceNames ty_decls cls_decls binds
- = mapAndUnzipRn getTyDeclNames ty_decls `thenRn` \ (tycon_s, constrs_s) ->
- mapAndUnzipRn getClassNames cls_decls `thenRn` \ (cls_s, cls_ops_s) ->
- getTopBindsNames binds `thenRn` \ bind_names ->
- returnRn (unionManyBags constrs_s `unionBags`
- unionManyBags cls_ops_s `unionBags` bind_names,
- listToBag tycon_s `unionBags` listToBag cls_s)
-
-
-getTyDeclNames :: RdrNameTyDecl
- -> RnM_Info s (RnName, Bag RnName) -- tycon and constrs
-
-getTyDeclNames (TyData _ tycon _ condecls _ _ src_loc)
- = newGlobalName src_loc Nothing tycon `thenRn` \ tycon_name ->
- mapRn (getConDeclName (Just (nameExportFlag tycon_name)))
- condecls `thenRn` \ con_names ->
- returnRn (RnData tycon_name con_names,
- listToBag (map (\ n -> RnConstr n tycon_name) con_names))
-
-getTyDeclNames (TyNew _ tycon _ condecls _ _ src_loc)
- = newGlobalName src_loc Nothing tycon `thenRn` \ tycon_name ->
- mapRn (getConDeclName (Just (nameExportFlag tycon_name)))
- condecls `thenRn` \ con_names ->
- returnRn (RnData tycon_name con_names,
- listToBag (map (\ n -> RnConstr n tycon_name) con_names))
-
-getTyDeclNames (TySynonym tycon _ _ src_loc)
- = newGlobalName src_loc Nothing tycon `thenRn` \ tycon_name ->
- returnRn (RnSyn tycon_name, emptyBag)
-
-getConDeclName exp (ConDecl con _ src_loc)
- = newGlobalName src_loc exp con
-getConDeclName exp (ConOpDecl _ op _ src_loc)
- = newGlobalName src_loc exp op
-getConDeclName exp (NewConDecl con _ src_loc)
- = newGlobalName src_loc exp con
-getConDeclName exp (RecConDecl con fields src_loc)
- = panic "getConDeclName:RecConDecl"
- newGlobalName src_loc exp con
-
-
-getClassNames :: RdrNameClassDecl
- -> RnM_Info s (RnName, Bag RnName) -- class and class ops
-
-getClassNames (ClassDecl _ cname _ sigs _ _ src_loc)
- = newGlobalName src_loc Nothing cname `thenRn` \ class_name ->
- getClassOpNames (Just (nameExportFlag class_name))
- sigs `thenRn` \ op_names ->
- returnRn (RnClass class_name op_names,
- listToBag (map (\ n -> RnClassOp n class_name) op_names))
-
-getClassOpNames exp []
- = returnRn []
-getClassOpNames exp (ClassOpSig op _ _ src_loc : sigs)
- = newGlobalName src_loc exp op `thenRn` \ op_name ->
- getClassOpNames exp sigs `thenRn` \ op_names ->
- returnRn (op_name : op_names)
-getClassOpNames exp (_ : sigs)
- = getClassOpNames exp sigs
+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
+
+ all_names :: [Name] -- All the defns; no dups eliminated
+ all_names = [name | avail <- avails, name <- availNames avail]
+
+ 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_`
+
+ 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{Bindings}
-* *
-*********************************************************
+
+%*********************************************************
+%* *
+\subsection{Getting binders out of a declaration}
+%* *
+%*********************************************************
+
+@getLocalDeclBinders@ returns the names for a @RdrNameHsDecl@. It's
+used for both source code (from @importsFromLocalDecls@) and interface
+files (@loadDecl@ calls @getTyClDeclBinders@).
+
+ *** See "THE NAMING STORY" in HsDecls ****
\begin{code}
-getTopBindsNames :: RdrNameHsBinds
- -> RnM_Info s (Bag RnName)
-
-getTopBindsNames binds = doBinds binds
-
-doBinds EmptyBinds = returnRn emptyBag
-doBinds (SingleBind bind) = doBind bind
-doBinds (BindWith bind sigs) = doBind bind
-doBinds (ThenBinds binds1 binds2)
- = andRn unionBags (doBinds binds1) (doBinds binds2)
-
-doBind EmptyBind = returnRn emptyBag
-doBind (NonRecBind mbind) = doMBinds mbind
-doBind (RecBind mbind) = doMBinds mbind
-
-doMBinds EmptyMonoBinds = returnRn emptyBag
-doMBinds (PatMonoBind pat grhss_and_binds locn) = doPat locn pat
-doMBinds (FunMonoBind p_name _ locn) = doName locn p_name
-doMBinds (AndMonoBinds mbinds1 mbinds2)
- = andRn unionBags (doMBinds mbinds1) (doMBinds mbinds2)
-
-doPats locn pats
- = mapRn (doPat locn) pats `thenRn` \ pats_s ->
- returnRn (unionManyBags pats_s)
-
-doPat locn WildPatIn = returnRn emptyBag
-doPat locn (LitPatIn _) = returnRn emptyBag
-doPat locn (LazyPatIn pat) = doPat locn pat
-doPat locn (VarPatIn var) = doName locn var
-doPat locn (NegPatIn pat) = doPat locn pat
-doPat locn (ParPatIn pat) = doPat locn pat
-doPat locn (ListPatIn pats) = doPats locn pats
-doPat locn (TuplePatIn pats) = doPats locn pats
-doPat locn (ConPatIn name pats) = doPats locn pats
-doPat locn (ConOpPatIn p1 op p2)
- = andRn unionBags (doPat locn p1) (doPat locn p2)
-doPat locn (AsPatIn as_name pat)
- = andRn unionBags (doName locn as_name) (doPat locn pat)
-doPat locn (RecPatIn name fields)
- = mapRn (doField locn) fields `thenRn` \ fields_s ->
- returnRn (unionManyBags fields_s)
-
-doField locn (field, _, True{-pun-}) = doName locn field
-doField locn (field, pat, _) = doPat locn pat
-
-doName locn rdr
- = newGlobalName locn Nothing rdr `thenRn` \ name ->
- returnRn (unitBag (RnName name))
+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
+ new (nm,loc) = newTopBinder mod nm loc
+
+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}
-*********************************************************
-* *
-\subsection{Creating a new global name}
-* *
-*********************************************************
+
+%************************************************************************
+%* *
+\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}
-newGlobalName :: SrcLoc -> Maybe ExportFlag
- -> RdrName -> RnM_Info s Name
-
-newGlobalName locn maybe_exp rdr
- = getExtraRn `thenRn` \ (_,_,exp_fn,occ_fn) ->
- getModuleRn `thenRn` \ mod ->
- getSourceRn `thenRn` \ source ->
- rnGetUnique `thenRn` \ u ->
+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
- src_unqual = getLocalName rdr
+ (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}
- src_orig = if fromPrelude mod
- then (Unqual src_unqual)
- else (Qual mod src_unqual)
+\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}
- exp = case maybe_exp of
- Just exp -> exp
- Nothing -> exp_fn n
- n = if source then
- mkTopLevName u src_orig locn exp (occ_fn n)
- else
- mkImportedName u rdr locn exp (occ_fn n)
- in
- addErrIfRn (source && isQual rdr)
- (qualNameErr "name in definition" (rdr, locn)) `thenRn_`
- returnRn n
-\end{code}
+%************************************************************************
+%* *
+\subsection{Export list processing}
+%* *
+%************************************************************************
-*********************************************************
-* *
-\subsection{Imported names}
-* *
-*********************************************************
+Processing the export list.
+
+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}
-getImportedNames ::
- IfaceCache
- -> GlobalNameInfo -- builtin and knot name info
- -> UniqSupply
- -> [RdrNameImportDecl] -- import declarations
- -> PrimIO (Bag (RdrName,RnName), -- imported values in scope
- Bag (RdrName,RnName), -- imported tycons/classes in scope
- Bag Module, -- directly imported modules
- Bag RenamedFixityDecl, -- fixity info for imported names
- Bag Error,
- Bag Warning)
-
-getImportedNames iface_var info us imports
- = returnPrimIO (builtin_vals, builtin_tcs, emptyBag, emptyBag, emptyBag, emptyBag)
+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 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
+ 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
- -- For now jsut add the builtin names ...
- (b_names,_,_,_) = info
- builtin_vals = listToBag [(Unqual s, rn) | (s,rn) <- fmToList b_names, not (isRnTyCon rn)]
- builtin_tcs = listToBag [(Unqual s, rn) | (s,rn) <- fmToList b_names, isRnTyCon rn]
+ 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}
+%* *
+%*********************************************************
\begin{code}
-globalDupNamesErr rdr rns sty
- = ppHang (ppBesides [pprNonOp sty rdr, ppStr " multiply defined:"])
- 4 (ppAboves (map pp_def rns))
+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
- pp_def rn = addShortErrLocLine (getSrcLoc rn) (\ sty -> ppr sty rn) sty
+ 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}
+
+
+%************************************************************************
+%* *
+\subsection{Errors}
+%* *
+%************************************************************************
- -- ToDo: print import src locs for imported names
+\begin{code}
+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}
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