X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnNames.lhs;h=1b02331064519499fcd2b3deddca9fc8fe7de089;hb=fffba9e37c59f6b03bb79dcafb818b88abc0ed47;hp=dcbf83195f6f3b5d5acd492da3dcb2d2786578f9;hpb=b4255f2c320f852d7dfb0afc0bc9f64765aece0c;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs index dcbf831..1b02331 100644 --- a/ghc/compiler/rename/RnNames.lhs +++ b/ghc/compiler/rename/RnNames.lhs @@ -1,297 +1,638 @@ % -% (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(..) + getGlobalNames ) where -import PreludeGlaST ( returnPrimIO, thenPrimIO, MutableVar(..) ) - -import Ubiq +#include "HsVersions.h" -import HsSyn -import RdrHsSyn -import RnHsSyn +import CmdLineOpts ( DynFlag(..), opt_NoImplicitPrelude ) -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(..), Name, isQual, mkTopLevName, - mkImportedName, nameExportFlag, - getLocalName, getSrcLoc, pprNonOp +import HsSyn ( HsModule(..), HsDecl(..), IE(..), ieName, ImportDecl(..), + collectTopBinders + ) +import RdrHsSyn ( RdrNameIE, RdrNameImportDecl, + RdrNameHsModule, RdrNameHsDecl ) -import PrelInfo ( BuiltinNames(..), BuiltinKeys(..) ) -import PrelMods ( fromPrelude ) -import Pretty -import SrcLoc ( SrcLoc ) -import UniqSupply ( splitUniqSupply ) -import Util ( equivClasses, panic ) +import RnIfaces ( getInterfaceExports, recordLocalSlurps ) +import RnHiFiles ( getDeclBinders ) +import RnEnv +import RnMonad + +import FiniteMap +import PrelNames ( pRELUDE_Name, mAIN_Name, main_RDR ) +import UniqFM ( lookupUFM ) +import Bag ( bagToList ) +import Module ( ModuleName, mkModuleInThisPackage, WhereFrom(..) ) +import NameSet +import Name ( Name, nameSrcLoc, + setLocalNameSort, nameOccName, nameEnvElts ) +import HscTypes ( Provenance(..), ImportReason(..), GlobalRdrEnv, + GenAvailInfo(..), AvailInfo, Avails, AvailEnv ) +import RdrName ( RdrName, rdrNameOcc, setRdrNameOcc, mkRdrQual, mkRdrUnqual, isUnqual ) +import OccName ( setOccNameSpace, dataName ) +import NameSet ( elemNameSet, emptyNameSet ) +import Outputable +import Maybes ( maybeToBool, catMaybes, mapMaybe ) +import UniqFM ( emptyUFM, listToUFM ) +import ListSetOps ( removeDups ) +import Util ( sortLt ) +import List ( partition ) \end{code} + +%************************************************************************ +%* * +\subsection{Get global names} +%* * +%************************************************************************ + \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) -> +getGlobalNames :: RdrNameHsModule + -> RnMG (Maybe (GlobalRdrEnv, -- Maps all in-scope things + GlobalRdrEnv, -- Maps just *local* things + Avails, -- The exported stuff + AvailEnv -- Maps a name to its parent AvailInfo + -- Just for in-scope things only + )) + -- Nothing => no need to recompile + +getGlobalNames (HsModule this_mod _ exports imports decls _ mod_loc) + = -- These two fix-loops are to get the right + -- provenance information into a Name + fixRn ( \ ~(Just (rec_gbl_env, _, rec_export_avails, _)) -> + + let + rec_unqual_fn :: Name -> Bool -- Is this chap in scope unqualified? + rec_unqual_fn = unQualInScope rec_gbl_env + + rec_exp_fn :: Name -> Bool + rec_exp_fn = mk_export_fn (availsToNameSet rec_export_avails) + in + + -- PROCESS LOCAL DECLS + -- Do these *first* so that the correct provenance gets + -- into the global name cache. + importsFromLocalDecls this_mod rec_exp_fn decls + `thenRn` \ (local_gbl_env, local_mod_avails) -> + + -- PROCESS IMPORT DECLS + -- Do the non {- SOURCE -} ones first, so that we get a helpful + -- warning for {- SOURCE -} ones that are unnecessary + let + (source, ordinary) = partition is_source_import all_imports + is_source_import (ImportDecl _ ImportByUserSource _ _ _ _) = True + is_source_import other = False + in + mapAndUnzipRn (importsFromImportDecl rec_unqual_fn) ordinary + `thenRn` \ (imp_gbl_envs1, imp_avails_s1) -> + mapAndUnzipRn (importsFromImportDecl rec_unqual_fn) source + `thenRn` \ (imp_gbl_envs2, imp_avails_s2) -> + + -- COMBINE RESULTS + -- We put the local env second, so that a local provenance + -- "wins", even if a module imports itself. + let + gbl_env :: GlobalRdrEnv + imp_gbl_env = foldr plusGlobalRdrEnv emptyRdrEnv (imp_gbl_envs2 ++ imp_gbl_envs1) + gbl_env = imp_gbl_env `plusGlobalRdrEnv` local_gbl_env + + all_avails :: ExportAvails + all_avails = foldr plusExportAvails local_mod_avails (imp_avails_s2 ++ imp_avails_s1) + (_, global_avail_env) = all_avails + in + + -- TRY FOR EARLY EXIT + -- We can't go for an early exit before this because we have to check + -- for name clashes. Consider: + -- + -- module A where module B where + -- import B h = True + -- f = h + -- + -- Suppose I've compiled everything up, and then I add a + -- new definition to module B, that defines "f". + -- + -- Then I must detect the name clash in A before going for an early + -- exit. The early-exit code checks what's actually needed from B + -- to compile A, and of course that doesn't include B.f. That's + -- why we wait till after the plusEnv stuff to do the early-exit. + + -- Check For early exit + checkErrsRn `thenRn` \ no_errs_so_far -> + if not no_errs_so_far then + -- Found errors already, so exit now + returnRn Nothing + else + + -- PROCESS EXPORT LISTS + exportsFromAvail this_mod exports all_avails gbl_env `thenRn` \ export_avails -> + + + -- ALL DONE + returnRn (Just (gbl_env, local_gbl_env, export_avails, global_avail_env)) + ) + where + 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. + prel_imports | this_mod == pRELUDE_Name || + explicit_prelude_import || + opt_NoImplicitPrelude + = [] + + | otherwise = [ImportDecl pRELUDE_Name + ImportByUser + False {- Not qualified -} + Nothing {- No "as" -} + Nothing {- No import list -} + mod_loc] + + explicit_prelude_import + = not (null [ () | (ImportDecl mod _ _ _ _ _) <- imports, mod == pRELUDE_Name ]) +\end{code} + +\begin{code} +importsFromImportDecl :: (Name -> Bool) -- OK to omit qualifier + -> RdrNameImportDecl + -> RnMG (GlobalRdrEnv, + ExportAvails) + +importsFromImportDecl is_unqual (ImportDecl imp_mod_name from qual_only as_mod import_spec iloc) + = pushSrcLocRn iloc $ + getInterfaceExports imp_mod_name from `thenRn` \ (imp_mod, avails) -> + + if null avails then + -- If there's an error in getInterfaceExports, (e.g. interface + -- file not found) we get lots of spurious errors from 'filterImports' + returnRn (emptyRdrEnv, mkEmptyExportAvails imp_mod_name) + else + + filterImports imp_mod_name import_spec avails `thenRn` \ (filtered_avails, hides, explicits) -> let - unqual_vals = mapBag (\rn -> (Unqual (getLocalName rn), rn)) src_vals - unqual_tcs = mapBag (\rn -> (Unqual (getLocalName rn), rn)) src_tcs + mk_provenance name = NonLocalDef (UserImport imp_mod iloc (name `elemNameSet` explicits)) + (is_unqual name) + in + + qualifyImports imp_mod_name + (not qual_only) -- Maybe want unqualified names + as_mod hides + mk_provenance + filtered_avails +\end{code} - all_vals = bagToList (unqual_vals `unionBags` imp_vals) - all_tcs = bagToList (unqual_tcs `unionBags` imp_tcs) - (all_env, dups) = extendGlobalRnEnv emptyRnEnv all_vals all_tcs +\begin{code} +importsFromLocalDecls mod_name rec_exp_fn decls + = mapRn (getLocalDeclBinders mod rec_exp_fn) decls `thenRn` \ avails_s -> + + let + avails = concat avails_s - 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]) + all_names :: [Name] -- All the defns; no dups eliminated + all_names = [name | avail <- avails, name <- availNames avail] - all_errs = src_errs `unionBags` imp_errs `unionBags` listToBag dup_errs - all_warns = src_warns `unionBags` imp_warns + dups :: [[Name]] + (_, dups) = removeDups compare all_names in - returnPrimIO (all_env, bagToList imp_mods, imp_fixes, all_errs, all_warns) - } + -- Check for duplicate definitions + mapRn_ (addErrRn . dupDeclErr) dups `thenRn_` + + -- Record that locally-defined things are available + recordLocalSlurps avails `thenRn_` + + -- Build the environment + qualifyImports mod_name + True -- Want unqualified names + Nothing -- no 'as M' + [] -- Hide nothing + (\n -> LocalDef) -- Provenance is local + avails where - (us1, us2) = splitUniqSupply us + mod = mkModuleInThisPackage mod_name + +getLocalDeclBinders :: Module + -> (Name -> Bool) -- Is-exported predicate + -> RdrNameHsDecl -> RnMG Avails +getLocalDeclBinders mod rec_exp_fn (ValD binds) + = mapRn do_one (bagToList (collectTopBinders binds)) + where + do_one (rdr_name, loc) = newLocalName mod rec_exp_fn rdr_name loc `thenRn` \ name -> + returnRn (Avail name) + +getLocalDeclBinders mod rec_exp_fn decl + = getDeclBinders (newLocalName mod rec_exp_fn) decl `thenRn` \ maybe_avail -> + case maybe_avail of + Nothing -> returnRn [] -- Instance decls and suchlike + Just avail -> returnRn [avail] + +newLocalName mod rec_exp_fn rdr_name loc + = check_unqual rdr_name loc `thenRn_` + newTopBinder mod rdr_name loc `thenRn` \ name -> + returnRn (setLocalNameSort name (rec_exp_fn name)) + where + -- There should never be a qualified name in a binding position (except in instance decls) + -- The parser doesn't check this because the same parser parses instance decls + check_unqual rdr_name loc + | isUnqual rdr_name = returnRn () + | otherwise = qualNameErr (text "the binding for" <+> quotes (ppr rdr_name)) + (rdr_name,loc) \end{code} -********************************************************* -* * -\subsection{Top-level source names} -* * -********************************************************* -\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 -\end{code} +%************************************************************************ +%* * +\subsection{Filtering imports} +%* * +%************************************************************************ -********************************************************* -* * -\subsection{Bindings} -* * -********************************************************* +@filterImports@ takes the @ExportEnv@ telling what the imported module makes +available, and filters it through the import spec (if any). \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)) +filterImports :: ModuleName -- The module being imported + -> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hiding + -> [AvailInfo] -- What's available + -> RnMG ([AvailInfo], -- What's actually imported + [AvailInfo], -- What's to be hidden + -- (the unqualified version, that is) + -- (We need to return both the above sets, because + -- the qualified version is never hidden; so we can't + -- implement hiding by reducing 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 Nothing imports + = returnRn (imports, [], emptyNameSet) + +filterImports mod (Just (want_hiding, import_items)) avails + = flatMapRn get_item import_items `thenRn` \ avails_w_explicits -> + let + (item_avails, explicits_s) = unzip avails_w_explicits + explicits = foldl addListToNameSet emptyNameSet explicits_s + in + if want_hiding + then + -- All imported; item_avails to be hidden + returnRn (avails, item_avails, emptyNameSet) + else + -- Just item_avails imported; nothing to be hidden + returnRn (item_avails, [], explicits) + where + import_fm :: FiniteMap OccName AvailInfo + import_fm = listToFM [ (nameOccName name, avail) + | avail <- 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 = addErrRn (badImportItemErr mod item) `thenRn_` + returnRn [] + + 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 + addWarnRn (dodgyImportWarn mod item) `thenRn_` + returnRn [(avail, [availName avail])] + Just avail -> returnRn [(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 (IEThingAbs data_n)] of + [] -> bale_out item + avails -> returnRn [(a, []) | a <- avails] + -- The 'explicits' list is irrelevant when hiding + where + data_n = setRdrNameOcc n (setOccNameSpace (rdrNameOcc n) dataName) + + get_item item + = case check_item item of + Nothing -> bale_out item + Just avail -> returnRn [(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} -********************************************************* -* * -\subsection{Creating a new global name} -* * -********************************************************* + + +%************************************************************************ +%* * +\subsection{Qualifiying imports} +%* * +%************************************************************************ + +@qualifyImports@ takes the @ExportEnv@ after filtering through the import spec +of an import decl, and deals with producing an @RnEnv@ with the +right qualified names. It also turns the @Names@ in the @ExportEnv@ into +fully fledged @Names@. \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 -> +qualifyImports :: ModuleName -- Imported module + -> Bool -- True <=> want unqualified import + -> Maybe ModuleName -- Optional "as M" part + -> [AvailInfo] -- What's to be hidden + -> (Name -> Provenance) + -> Avails -- Whats imported and how + -> RnMG (GlobalRdrEnv, ExportAvails) + +qualifyImports this_mod unqual_imp as_mod hides mk_provenance avails + = + -- Make the name environment. We're talking about a + -- single module here, so there must be no name clashes. + -- In practice there only ever will be if it's the module + -- being compiled. let - src_unqual = getLocalName rdr - - src_orig = if fromPrelude mod - then (Unqual src_unqual) - else (Qual mod src_unqual) + -- Add the things that are available + name_env1 = foldl add_avail emptyRdrEnv avails - exp = case maybe_exp of - Just exp -> exp - Nothing -> exp_fn n + -- Delete things that are hidden + name_env2 = foldl del_avail name_env1 hides - n = if source then - mkTopLevName u src_orig locn exp (occ_fn n) - else - mkImportedName u rdr locn exp (occ_fn n) + -- Create the export-availability info + export_avails = mkExportAvails qual_mod unqual_imp name_env2 avails in - addErrIfRn (source && isQual rdr) - (qualNameErr "name in definition" (rdr, locn)) `thenRn_` - returnRn n + returnRn (name_env2, export_avails) + + where + qual_mod = case as_mod of + Nothing -> this_mod + Just another_name -> another_name + + add_avail :: GlobalRdrEnv -> AvailInfo -> GlobalRdrEnv + add_avail env avail = foldl add_name env (availNames avail) + + add_name env name + | unqual_imp = env2 + | otherwise = env1 + where + env1 = addOneToGlobalRdrEnv env (mkRdrQual qual_mod occ) (name,prov) + env2 = addOneToGlobalRdrEnv env1 (mkRdrUnqual occ) (name,prov) + occ = nameOccName name + prov = mk_provenance name + + del_avail env avail = foldl delOneFromGlobalRdrEnv env rdr_names + where + rdr_names = map (mkRdrUnqual . nameOccName) (availNames avail) + + +mkEmptyExportAvails :: ModuleName -> ExportAvails +mkEmptyExportAvails mod_name = (unitFM mod_name [], emptyUFM) + +mkExportAvails :: ModuleName -> Bool -> GlobalRdrEnv -> [AvailInfo] -> ExportAvails +mkExportAvails mod_name unqual_imp name_env avails + = (mod_avail_env, entity_avail_env) + where + mod_avail_env = unitFM mod_name unqual_avails + + -- unqual_avails is the Avails that are visible in *unqualfied* form + -- (1.4 Report, Section 5.1.1) + -- For example, in + -- import T hiding( f ) + -- we delete f from avails + + unqual_avails | not unqual_imp = [] -- Short cut when no unqualified imports + | otherwise = mapMaybe prune avails + + prune (Avail n) | unqual_in_scope n = Just (Avail n) + prune (Avail n) | otherwise = Nothing + prune (AvailTC n ns) | null uqs = Nothing + | otherwise = Just (AvailTC n uqs) + where + uqs = filter unqual_in_scope ns + + unqual_in_scope n = unQualInScope name_env n + + entity_avail_env = listToUFM [ (name,avail) | avail <- avails, + name <- availNames avail] + +plusExportAvails :: ExportAvails -> ExportAvails -> ExportAvails +plusExportAvails (m1, e1) (m2, e2) + = (plusFM_C (++) m1 m2, plusAvailEnv e1 e2) + -- ToDo: wasteful: we do this once for each constructor! \end{code} -********************************************************* -* * -\subsection{Imported names} -* * -********************************************************* + +%************************************************************************ +%* * +\subsection{Export list processing} +%* * +%************************************************************************ + +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 + +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 :: ModuleName + -> Maybe [RdrNameIE] -- Export spec + -> ExportAvails + -> GlobalRdrEnv + -> RnMG Avails + -- Complains if two distinct exports have same OccName + -- Warns about identical exports. + -- Complains about exports items not in scope +exportsFromAvail this_mod Nothing export_avails global_name_env + = exportsFromAvail this_mod true_exports export_avails global_name_env 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] + true_exports = Just $ if this_mod == mAIN_Name + then [IEVar main_RDR] + -- export Main.main *only* unless otherwise specified, + else [IEModuleContents this_mod] + -- but for all other modules export everything. + +exportsFromAvail this_mod (Just export_items) + (mod_avail_env, entity_avail_env) + global_name_env + = doptRn Opt_WarnDuplicateExports `thenRn` \ warn_dup_exports -> + foldlRn (exports_from_item warn_dup_exports) + ([], emptyFM, emptyAvailEnv) export_items + `thenRn` \ (_, _, export_avail_map) -> + let + export_avails :: [AvailInfo] + export_avails = nameEnvElts export_avail_map + in + returnRn export_avails + + where + exports_from_item :: Bool -> ExportAccum -> RdrNameIE -> RnMG ExportAccum + + exports_from_item warn_dups acc@(mods, occs, avails) ie@(IEModuleContents mod) + | mod `elem` mods -- Duplicate export of M + = warnCheckRn warn_dups (dupModuleExport mod) `thenRn_` + returnRn acc + + | otherwise + = case lookupFM mod_avail_env mod of + Nothing -> failWithRn acc (modExportErr mod) + Just mod_avails -> foldlRn (check_occs ie) occs mod_avails + `thenRn` \ occs' -> + let + avails' = foldl addAvail avails mod_avails + in + returnRn (mod:mods, occs', avails') + + exports_from_item warn_dups acc@(mods, occs, avails) ie + | not (maybeToBool maybe_in_scope) + = failWithRn acc (unknownNameErr (ieName ie)) + + | not (null dup_names) + = addNameClashErrRn rdr_name ((name,prov):dup_names) `thenRn_` + returnRn acc + +#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 name) + returnRn acc +#endif + + | not enough_avail + = failWithRn acc (exportItemErr ie) + + | otherwise -- Phew! It's OK! Now to check the occurrence stuff! + + + = warnCheckRn (ok_item ie avail) (dodgyExportWarn ie) `thenRn_` + check_occs ie occs export_avail `thenRn` \ occs' -> + returnRn (mods, occs', addAvail avails export_avail) + + where + rdr_name = ieName ie + maybe_in_scope = lookupFM global_name_env rdr_name + Just ((name,prov):dup_names) = maybe_in_scope + maybe_avail = lookupUFM entity_avail_env name + Just avail = maybe_avail + maybe_export_avail = filterAvail ie avail + enough_avail = maybeToBool maybe_export_avail + Just export_avail = maybe_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 :: RdrNameIE -> ExportOccMap -> AvailInfo -> RnMG ExportOccMap +check_occs ie occs avail + = doptRn Opt_WarnDuplicateExports `thenRn` \ warn_dup_exports -> + foldlRn (check warn_dup_exports) occs (availNames avail) + where + check warn_dup occs name + = case lookupFM occs name_occ of + Nothing -> returnRn (addToFM occs name_occ (name, ie)) + Just (name', ie') + | name == name' -> -- Duplicate export + warnCheckRn warn_dup + (dupExportWarn name_occ ie ie') + `thenRn_` returnRn occs + + | otherwise -> -- Same occ name but different names: an error + failWithRn occs (exportClashErr name_occ ie ie') + where + name_occ = nameOccName name + +mk_export_fn :: NameSet -> (Name -> Bool) -- True => exported +mk_export_fn exported_names = \name -> name `elemNameSet` exported_names \end{code} +%************************************************************************ +%* * +\subsection{Errors} +%* * +%************************************************************************ \begin{code} -globalDupNamesErr rdr rns sty - = ppHang (ppBesides [pprNonOp sty rdr, ppStr " multiply defined:"]) - 4 (ppAboves (map pp_def rns)) +badImportItemErr mod ie + = sep [ptext SLIT("Module"), quotes (ppr mod), + ptext SLIT("does not export"), quotes (ppr ie)] + +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 - pp_def rn = addShortErrLocLine (getSrcLoc rn) (\ sty -> ppr sty rn) sty - - -- ToDo: print import src locs for imported names + 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")] \end{code}