X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnNames.lhs;h=4e745f192a523f80739c7f1a7da433c88a62d9f5;hb=dbc254c3dcd64761015a3d1c191ac742caafbf4c;hp=f391cbc09e3b0039c6af792ac5f4f5e769ed8e1f;hpb=c49d51f812da9b1c2ceca7e0dad8f2a3626041a9;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs index f391cbc..8eef805 100644 --- a/ghc/compiler/rename/RnNames.lhs +++ b/ghc/compiler/rename/RnNames.lhs @@ -1,300 +1,799 @@ % -% (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 +#include "HsVersions.h" -import HsSyn -import RdrHsSyn -import RnHsSyn +import {-# SOURCE #-} RnHiFiles ( loadInterface ) -import ParseIface ( ParsedIface ) -import RnMonad -import RnIfaces ( IfaceCache(..), cachedIface ) -import RnUtils ( RnEnv(..), emptyRnEnv, extendGlobalRnEnv, qualNameErr, dupNamesErr ) +import CmdLineOpts ( DynFlag(..) ) -import Bag ( emptyBag, unitBag, unionBags, unionManyBags, mapBag, listToBag, bagToList ) -import ErrUtils ( Error(..), Warning(..), addShortErrLocLine ) -import FiniteMap ( fmToList ) -import Name ( RdrName(..), Name, isQual, mkTopLevName, - mkImportedName, nameExportFlag, - getLocalName, getSrcLoc, pprNonOp +import HsSyn ( HsDecl(..), IE(..), ieName, ImportDecl(..), + ForeignDecl(..), + collectLocatedHsBinders, tyClDeclNames ) -import PrelInfo ( BuiltinNames(..), BuiltinKeys(..) ) -import PrelMods ( fromPrelude ) -import Pretty -import SrcLoc ( SrcLoc ) -import UniqSupply ( splitUniqSupply ) -import Util ( equivClasses, panic ) +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} -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], -- directly imported modules - Bag (Module,(RnName,ExportFlag)), -- unqualified imports from module - Bag RenamedFixityDecl, -- imported fixity decls - 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, unqual_imps, imp_fixes, imp_errs, imp_warns) -> +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} +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 - all_vals = bagToList (unqual_vals `unionBags` imp_vals) - all_tcs = bagToList (unqual_tcs `unionBags` imp_tcs) + -- 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_env, dups) = extendGlobalRnEnv emptyRnEnv all_vals all_tcs + case mb_iface of { + Nothing -> returnM (emptyRdrEnv, emptyImportAvails ) ; + Just iface -> - 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]) + 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. - all_errs = src_errs `unionBags` imp_errs `unionBags` listToBag dup_errs - all_warns = src_warns `unionBags` imp_warns in - returnPrimIO (all_env, bagToList imp_mods, unqual_imps, imp_fixes, all_errs, all_warns) + -- 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}) } - 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 (_, 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 (Module,(RnName,ExportFlag)), -- unqualified imports from module - 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, 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}