X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnNames.lhs;h=275f8302c91961e19eb7ed935480d0905b8196ae;hb=bb91427f27c940e4dd0fc6c7360e7ef61264b240;hp=db95e47d8bcb5b7b5ac611eaf098535f1792f3e0;hpb=90c0b29e6d8d847e5357bd0a9df98e2846046db7;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs index db95e47..275f830 100644 --- a/ghc/compiler/rename/RnNames.lhs +++ b/ghc/compiler/rename/RnNames.lhs @@ -14,16 +14,16 @@ import CmdLineOpts ( opt_NoImplicitPrelude, opt_WarnDuplicateExports, opt_SourceUnchanged, opt_WarnUnusedBinds ) -import HsSyn ( HsModule(..), ImportDecl(..), HsDecl(..), TyClDecl(..), +import HsSyn ( HsModule(..), HsDecl(..), TyClDecl(..), IE(..), ieName, - ForeignDecl(..), ForKind(..), isDynamic, - FixitySig(..), Sig(..), + ForeignDecl(..), ForKind(..), isDynamicExtName, + FixitySig(..), Sig(..), ImportDecl(..), collectTopBinders ) import RdrHsSyn ( RdrNameIE, RdrNameImportDecl, RdrNameHsModule, RdrNameHsDecl ) -import RnIfaces ( getInterfaceExports, getDeclBinders, getImportedFixities, +import RnIfaces ( getInterfaceExports, getDeclBinders, getDeclSysBinders, recordSlurp, checkUpToDate ) import RnEnv @@ -31,18 +31,25 @@ import RnMonad import FiniteMap import PrelMods +import PrelInfo ( main_RDR ) import UniqFM ( lookupUFM ) import Bag ( bagToList ) -import Maybes ( maybeToBool ) -import Module ( pprModule ) +import Module ( ModuleName, mkThisModule, pprModuleName, WhereFrom(..) ) import NameSet -import Name -import RdrName ( RdrName, rdrNameOcc, mkRdrQual, mkRdrUnqual ) +import Name ( Name, ExportFlag(..), ImportReason(..), Provenance(..), + isLocallyDefined, setNameProvenance, + nameOccName, getSrcLoc, pprProvenance, getNameProvenance + ) +import RdrName ( RdrName, rdrNameOcc, setRdrNameOcc, mkRdrQual, mkRdrUnqual, isQual ) +import OccName ( setOccNameSpace, dataName ) import SrcLoc ( SrcLoc ) import NameSet ( elemNameSet, emptyNameSet ) import Outputable +import Maybes ( maybeToBool, catMaybes, mapMaybe ) +import UniqFM ( emptyUFM, listToUFM, plusUFM_C ) import Unique ( getUnique ) import Util ( removeDups, equivClassesByUniq, sortLt ) +import List ( partition ) \end{code} @@ -56,49 +63,57 @@ import Util ( removeDups, equivClassesByUniq, sortLt ) \begin{code} getGlobalNames :: RdrNameHsModule -> RnMG (Maybe (ExportEnv, - RnEnv, - NameEnv AvailInfo -- Maps a name to its parent AvailInfo - -- Just for in-scope things only + GlobalRdrEnv, + FixityEnv, -- Fixities for local decls only + 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) +getGlobalNames (HsModule this_mod _ exports imports decls _ mod_loc) = -- These two fix-loops are to get the right -- provenance information into a Name - fixRn (\ ~(rec_exported_avails, _) -> + fixRn (\ ~(rec_gbl_env, rec_exported_avails, _) -> - fixRn (\ ~(rec_rn_env, _) -> let rec_unqual_fn :: Name -> Bool -- Is this chap in scope unqualified? - rec_unqual_fn = unQualInScope rec_rn_env + rec_unqual_fn = unQualInScope rec_gbl_env rec_exp_fn :: Name -> ExportFlag rec_exp_fn = mk_export_fn (availsToNameSet rec_exported_avails) in - setOmitQualFn rec_unqual_fn $ setModuleRn this_mod $ -- 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) -> + importsFromLocalDecls this_mod rec_exp_fn decls + `thenRn` \ (local_gbl_env, local_mod_avails) -> -- PROCESS IMPORT DECLS - mapAndUnzipRn importsFromImportDecl all_imports `thenRn` \ (imp_gbl_envs, imp_avails_s) -> + -- 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_envs + 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_s + all_avails = foldr plusExportAvails local_mod_avails (imp_avails_s2 ++ imp_avails_s1) in - returnRn (gbl_env, all_avails) - ) `thenRn` \ (gbl_env, all_avails) -> -- TRY FOR EARLY EXIT -- We can't go for an early exit before this because we have to check @@ -114,47 +129,54 @@ getGlobalNames (HsModule this_mod _ exports imports decls mod_loc) -- 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 plusRnEnv stuff to do the early-exit. + -- why we wait till after the plusEnv stuff to do the early-exit. checkEarlyExit this_mod `thenRn` \ up_to_date -> if up_to_date then - returnRn (junk_exp_fn, Nothing) + returnRn (gbl_env, junk_exp_fn, Nothing) else + -- RECORD BETTER PROVENANCES IN THE CACHE + -- The names in the envirnoment have better provenances (e.g. imported on line x) + -- than the names in the name cache. We update the latter now, so that we + -- we start renaming declarations we'll get the good names + -- The isQual is because the qualified name is always in scope + updateProvenances (concat [names | (rdr_name, names) <- rdrEnvToList imp_gbl_env, + isQual rdr_name]) `thenRn_` + -- PROCESS EXPORT LISTS - exportsFromAvail this_mod exports all_avails gbl_env `thenRn` \ exported_avails -> + exportsFromAvail this_mod exports all_avails gbl_env `thenRn` \ exported_avails -> -- DONE - returnRn (exported_avails, Just (all_avails, gbl_env)) - ) `thenRn` \ (exported_avails, maybe_stuff) -> + returnRn (gbl_env, exported_avails, Just all_avails) + ) `thenRn` \ (gbl_env, exported_avails, maybe_stuff) -> case maybe_stuff of { Nothing -> returnRn Nothing ; - Just (all_avails, gbl_env) -> - + Just all_avails -> -- DEAL WITH FIXITIES fixitiesFromLocalDecls gbl_env decls `thenRn` \ local_fixity_env -> - getImportedFixities gbl_env `thenRn` \ imp_fixity_env -> let -- Export only those fixities that are for names that are -- (a) defined in this module -- (b) exported exported_fixities :: [(Name,Fixity)] - exported_fixities = [(name,fixity) | FixitySig name fixity _ <- nameEnvElts local_fixity_env, - isLocallyDefined name + exported_fixities = [(name,fixity) + | FixitySig name fixity _ <- nameEnvElts local_fixity_env, + isLocallyDefined name ] - fixity_env = imp_fixity_env `plusNameEnv` local_fixity_env - in - traceRn (text "fixity env" <+> vcat (map ppr (nameEnvElts fixity_env))) `thenRn_` + -- CONSTRUCT RESULTS + export_mods = case exports of + Nothing -> [] + Just es -> [mod | IEModuleContents mod <- es, mod /= this_mod] - --- TIDY UP - let - export_env = ExportEnv exported_avails exported_fixities - rn_env = RnEnv gbl_env fixity_env + export_env = ExportEnv exported_avails exported_fixities export_mods (_, global_avail_env) = all_avails in - returnRn (Just (export_env, rn_env, global_avail_env)) + traceRn (text "fixity env" <+> vcat (map ppr (nameEnvElts local_fixity_env))) `thenRn_` + + returnRn (Just (export_env, gbl_env, local_fixity_env, global_avail_env)) } where junk_exp_fn = error "RnNames:export_fn" @@ -164,19 +186,20 @@ getGlobalNames (HsModule this_mod _ exports imports decls mod_loc) -- 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 || + prel_imports | this_mod == pRELUDE_Name || explicit_prelude_import || opt_NoImplicitPrelude = [] - | otherwise = [ImportDecl pRELUDE - False {- Not qualified -} - Nothing {- No "as" -} - Nothing {- No import list -} - mod_loc] + | otherwise = [ImportDecl pRELUDE_Name + ImportByUser + False {- Not qualified -} + Nothing {- No "as" -} + Nothing {- No import list -} + mod_loc] explicit_prelude_import - = not (null [ () | (ImportDecl mod qual _ _ _) <- imports, mod == pRELUDE ]) + = not (null [ () | (ImportDecl mod _ _ _ _ _) <- imports, mod == pRELUDE_Name ]) \end{code} \begin{code} @@ -197,49 +220,56 @@ checkEarlyExit mod -- Unchanged source, and no errors yet; see if usage info -- up to date, and exit if so checkUpToDate mod `thenRn` \ up_to_date -> - putDocRn (text "Compilation" <+> - text (if up_to_date then "IS NOT" else "IS") <+> - text "required") `thenRn_` + (if up_to_date + then putDocRn (text "Compilation IS NOT required") + else returnRn ()) `thenRn_` returnRn up_to_date \end{code} \begin{code} -importsFromImportDecl :: RdrNameImportDecl +importsFromImportDecl :: (Name -> Bool) -- OK to omit qualifier + -> RdrNameImportDecl -> RnMG (GlobalRdrEnv, ExportAvails) -importsFromImportDecl (ImportDecl imp_mod qual_only as_mod import_spec iloc) +importsFromImportDecl is_unqual (ImportDecl imp_mod_name from qual_only as_mod import_spec iloc) = pushSrcLocRn iloc $ - getInterfaceExports imp_mod `thenRn` \ (imp_mod, avails) -> + 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) + returnRn (emptyRdrEnv, mkEmptyExportAvails imp_mod_name) else - filterImports imp_mod import_spec avails `thenRn` \ (filtered_avails, hides, explicits) -> + filterImports imp_mod_name import_spec avails `thenRn` \ (filtered_avails, hides, explicits) -> + + qualifyImports imp_mod_name + (not qual_only) -- Maybe want unqualified names + as_mod hides + (improveAvails imp_mod iloc explicits + is_unqual filtered_avails) + +improveAvails imp_mod iloc explicits is_unqual avails -- We 'improve' the provenance by setting -- (a) the import-reason field, so that the Name says how it came into scope -- including whether it's explicitly imported -- (b) the print-unqualified field - -- But don't fiddle with wired-in things or we get in a twist - let - improve_prov name = setNameImportReason name (UserImport imp_mod iloc (is_explicit name)) - is_explicit name = name `elemNameSet` explicits - in - qualifyImports imp_mod - (not qual_only) -- Maybe want unqualified names - as_mod hides - filtered_avails improve_prov `thenRn` \ (rdr_name_env, mod_avails) -> + = map improve_avail avails + where + improve_avail (Avail n) = Avail (improve n) + improve_avail (AvailTC n ns) = AvailTC n (map improve ns) -- n doesn't matter - returnRn (rdr_name_env, mod_avails) + improve name = setNameProvenance name + (NonLocalDef (UserImport imp_mod iloc (is_explicit name)) + (is_unqual name)) + is_explicit name = name `elemNameSet` explicits \end{code} \begin{code} -importsFromLocalDecls mod rec_exp_fn decls +importsFromLocalDecls mod_name rec_exp_fn decls = mapRn (getLocalDeclBinders newLocalName) decls `thenRn` \ avails_s -> let @@ -249,28 +279,34 @@ importsFromLocalDecls mod rec_exp_fn decls all_names = [name | avail <- avails, name <- availNames avail] dups :: [[Name]] - dups = filter non_singleton (equivClassesByUniq getUnique all_names) - where - non_singleton (x1:x2:xs) = True - non_singleton other = False + (_, dups) = removeDups compare all_names in -- Check for duplicate definitions - mapRn_ (addErrRn . dupDeclErr) dups `thenRn_` + mapRn_ (addErrRn . dupDeclErr) dups `thenRn_` -- Record that locally-defined things are available - mapRn_ (recordSlurp Nothing Compulsory) avails `thenRn_` + mapRn_ (recordSlurp Nothing) avails `thenRn_` -- Build the environment - qualifyImports mod + qualifyImports mod_name True -- Want unqualified names Nothing -- no 'as M' [] -- Hide nothing avails - (\n -> n) where - newLocalName rdr_name loc = newLocallyDefinedGlobalName mod (rdrNameOcc rdr_name) - rec_exp_fn loc + mod = mkThisModule mod_name + + newLocalName rdr_name loc + = (if isQual rdr_name then + qualNameErr (text "the binding for" <+> quotes (ppr rdr_name)) (rdr_name,loc) + -- 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 + else + returnRn ()) `thenRn_` + + newLocalTopBinder mod (rdrNameOcc rdr_name) rec_exp_fn loc + getLocalDeclBinders :: (RdrName -> SrcLoc -> RnMG Name) -- New-name function -> RdrNameHsDecl @@ -281,24 +317,16 @@ getLocalDeclBinders new_name (ValD binds) do_one (rdr_name, loc) = new_name rdr_name loc `thenRn` \ name -> returnRn (Avail name) - -- foreign declarations -getLocalDeclBinders new_name (ForD (ForeignDecl nm kind _ dyn _ loc)) - | binds_haskell_name kind dyn - = new_name nm loc `thenRn` \ name -> - returnRn [Avail name] - - | otherwise - = returnRn [] - getLocalDeclBinders new_name decl = getDeclBinders new_name decl `thenRn` \ maybe_avail -> case maybe_avail of Nothing -> returnRn [] -- Instance decls and suchlike - Just avail -> returnRn [avail] - -binds_haskell_name (FoImport _) _ = True -binds_haskell_name FoLabel _ = True -binds_haskell_name FoExport ext_nm = isDynamic ext_nm + Just avail -> getDeclSysBinders new_sys_name decl `thenRn_` + returnRn [avail] + where + -- The getDeclSysBinders is just to get the names of superclass selectors + -- etc, into the cache + new_sys_name rdr_name loc = newImplicitBinder (rdrNameOcc rdr_name) loc fixitiesFromLocalDecls :: GlobalRdrEnv -> [RdrNameHsDecl] -> RnMG FixityEnv fixitiesFromLocalDecls gbl_env decls @@ -308,28 +336,26 @@ fixitiesFromLocalDecls gbl_env decls getFixities acc (FixD fix) = fix_decl acc fix - - getFixities acc (TyClD (ClassDecl _ _ _ sigs _ _ _ _ _)) + getFixities acc (TyClD (ClassDecl _ _ _ _ sigs _ _ _ _ _ _ _)) = foldlRn fix_decl acc [sig | FixSig sig <- sigs] -- Get fixities from class decl sigs too. getFixities acc other_decl = returnRn acc - fix_decl acc (FixitySig rdr_name fixity loc) + fix_decl acc sig@(FixitySig rdr_name fixity loc) = -- Check for fixity decl for something not declared case lookupRdrEnv gbl_env rdr_name of { Nothing | opt_WarnUnusedBinds - -> pushSrcLocRn loc (addWarnRn (unusedFixityDecl rdr_name fixity)) `thenRn_` - returnRn acc + -> pushSrcLocRn loc (addWarnRn (unusedFixityDecl rdr_name fixity)) + `thenRn_` returnRn acc | otherwise -> returnRn acc ; Just (name:_) -> -- Check for duplicate fixity decl case lookupNameEnv acc name of { - Just (FixitySig _ _ loc') -> addErrRn (dupFixityDecl rdr_name loc loc') `thenRn_` - returnRn acc ; - + Just (FixitySig _ _ loc') -> addErrRn (dupFixityDecl rdr_name loc loc') + `thenRn_` returnRn acc ; Nothing -> returnRn (addToNameEnv acc name (FixitySig name fixity loc)) }} @@ -345,11 +371,15 @@ fixitiesFromLocalDecls gbl_env decls available, and filters it through the import spec (if any). \begin{code} -filterImports :: Module -- The module being imported +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) + [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 @@ -358,7 +388,7 @@ filterImports mod Nothing imports = returnRn (imports, [], emptyNameSet) filterImports mod (Just (want_hiding, import_items)) avails - = mapMaybeRn check_item import_items `thenRn` \ avails_w_explicits -> + = flatMapRn get_item import_items `thenRn` \ avails_w_explicits -> let (item_avails, explicits_s) = unzip avails_w_explicits explicits = foldl addListToNameSet emptyNameSet explicits_s @@ -379,20 +409,43 @@ filterImports mod (Just (want_hiding, import_items)) avails -- they won't make any difference because naked entities like T -- in an import list map to TcOccs, not VarOccs. - check_item item@(IEModuleContents _) - = addErrRn (badImportItemErr mod item) `thenRn_` - returnRn Nothing + 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) - = addErrRn (badImportItemErr mod item) `thenRn_` - returnRn Nothing + = Nothing - | dodgy_import = addWarnRn (dodgyImportWarn mod item) `thenRn_` - returnRn (Just (filtered_avail, explicits)) - - | otherwise = returnRn (Just (filtered_avail, explicits)) + | otherwise + = Just filtered_avail where wanted_occ = rdrNameOcc (ieName item) @@ -401,20 +454,6 @@ filterImports mod (Just (want_hiding, import_items)) avails Just avail = maybe_in_import_avails maybe_filtered_avail = filterAvail item avail Just filtered_avail = maybe_filtered_avail - explicits | dot_dot = [availName filtered_avail] - | otherwise = availNames filtered_avail - - dot_dot = case item of - IEThingAll _ -> True - other -> False - - dodgy_import = case (item, avail) of - (IEThingAll _, AvailTC _ [n]) -> True - -- This occurs when you import T(..), but - -- only export T abstractly. The single [n] - -- in the AvailTC is the type or class itself - - other -> False \end{code} @@ -431,19 +470,14 @@ right qualified names. It also turns the @Names@ in the @ExportEnv@ into fully fledged @Names@. \begin{code} -qualifyImports :: Module -- Imported module +qualifyImports :: ModuleName -- Imported module -> Bool -- True <=> want unqualified import - -> Maybe Module -- Optional "as M" part + -> Maybe ModuleName -- Optional "as M" part -> [AvailInfo] -- What's to be hidden -> Avails -- Whats imported and how - -> (Name -> Name) -- Improves the provenance on imported things -> RnMG (GlobalRdrEnv, ExportAvails) - -- NB: the Names in ExportAvails don't have the improve-provenance - -- function applied to them - -- We could fix that, but I don't think it matters -qualifyImports this_mod unqual_imp as_mod hides - avails improve_prov +qualifyImports this_mod unqual_imp as_mod hides avails = -- Make the name environment. We're talking about a -- single module here, so there must be no name clashes. @@ -473,38 +507,76 @@ qualifyImports this_mod unqual_imp as_mod hides | unqual_imp = env2 | otherwise = env1 where - env1 = addOneToGlobalRdrEnv env (mkRdrQual qual_mod occ) better_name - env2 = addOneToGlobalRdrEnv env1 (mkRdrUnqual occ) better_name - occ = nameOccName name - better_name = improve_prov name + env1 = addOneToGlobalRdrEnv env (mkRdrQual qual_mod occ) name + env2 = addOneToGlobalRdrEnv env1 (mkRdrUnqual occ) name + occ = nameOccName 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{Export list processing +\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... +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} type ExportAccum -- The type of the accumulating parameter of -- the main worker function in exportsFromAvail - = ([Module], -- 'module M's seen so far + = ([ModuleName], -- 'module M's seen so far ExportOccMap, -- Tracks exported occurrence names - NameEnv AvailInfo) -- The accumulated exported stuff, kept in an env + AvailEnv) -- The accumulated exported stuff, kept in an env -- so we can common-up related AvailInfos type ExportOccMap = FiniteMap OccName (Name, RdrNameIE) @@ -514,7 +586,7 @@ type ExportOccMap = FiniteMap OccName (Name, RdrNameIE) -- that have the same occurrence name -exportsFromAvail :: Module +exportsFromAvail :: ModuleName -> Maybe [RdrNameIE] -- Export spec -> ExportAvails -> GlobalRdrEnv @@ -523,14 +595,19 @@ exportsFromAvail :: Module -- Warns about identical exports. -- Complains about exports items not in scope exportsFromAvail this_mod Nothing export_avails global_name_env - = exportsFromAvail this_mod (Just [IEModuleContents this_mod]) - export_avails global_name_env + = exportsFromAvail this_mod true_exports export_avails global_name_env + where + 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 = foldlRn exports_from_item - ([], emptyFM, emptyNameEnv) export_items `thenRn` \ (_, _, export_avail_map) -> + ([], emptyFM, emptyAvailEnv) export_items `thenRn` \ (_, _, export_avail_map) -> let export_avails :: [AvailInfo] export_avails = nameEnvElts export_avail_map @@ -549,9 +626,10 @@ exportsFromAvail this_mod (Just export_items) | 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' -> + Just mod_avails -> foldlRn (check_occs ie) occs mod_avails + `thenRn` \ occs' -> let - avails' = foldl add_avail avails mod_avails + avails' = foldl addAvail avails mod_avails in returnRn (mod:mods, occs', avails') @@ -575,8 +653,11 @@ exportsFromAvail this_mod (Just export_items) = failWithRn acc (exportItemErr ie) | otherwise -- Phew! It's OK! Now to check the occurrence stuff! - = check_occs ie occs export_avail `thenRn` \ occs' -> - returnRn (mods, occs', add_avail avails export_avail) + + + = 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 @@ -588,7 +669,11 @@ exportsFromAvail this_mod (Just export_items) enough_avail = maybeToBool maybe_export_avail Just export_avail = maybe_export_avail -add_avail avails avail = addToNameEnv_C plusAvail avails (availName avail) 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 @@ -600,8 +685,8 @@ check_occs ie occs avail Just (name', ie') | name == name' -> -- Duplicate export warnCheckRn opt_WarnDuplicateExports - (dupExportWarn name_occ ie ie') `thenRn_` - returnRn occs + (dupExportWarn name_occ ie ie') + `thenRn_` returnRn occs | otherwise -> -- Same occ name but different names: an error failWithRn occs (exportClashErr name_occ ie ie') @@ -623,23 +708,28 @@ mk_export_fn exported_names \begin{code} badImportItemErr mod ie - = sep [ptext SLIT("Module"), quotes (pprModule mod), + = sep [ptext SLIT("Module"), quotes (pprModuleName mod), ptext SLIT("does not export"), quotes (ppr ie)] -dodgyImportWarn mod (IEThingAll tc) - = sep [ptext SLIT("Module") <+> quotes (pprModule mod) <+> ptext SLIT("exports") <+> quotes (ppr tc), - ptext SLIT("with no constructors/class operations;"), - ptext SLIT("yet it is imported with a (..)")] +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 (pprModule mod)] + = hsep [ ptext SLIT("Unknown module in export list: module"), quotes (pprModuleName mod)] exportItemErr export_item - = sep [ ptext SLIT("Bad export item"), quotes (ppr 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)] + = 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), @@ -658,7 +748,7 @@ dupExportWarn occ_name ie1 ie2 dupModuleExport mod = hsep [ptext SLIT("Duplicate"), - quotes (ptext SLIT("Module") <+> pprModule mod), + quotes (ptext SLIT("Module") <+> pprModuleName mod), ptext SLIT("in export list")] unusedFixityDecl rdr_name fixity @@ -668,5 +758,4 @@ dupFixityDecl rdr_name loc1 loc2 = vcat [ptext SLIT("Multiple fixity declarations for") <+> quotes (ppr rdr_name), ptext SLIT("at ") <+> ppr loc1, ptext SLIT("and") <+> ppr loc2] - \end{code}