X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=ghc%2Fcompiler%2Frename%2FRnNames.lhs;h=5dc31005df766ba886550a05c64937b72f4e1213;hb=4166dff80e8ec94022a040318ff2759913fbbe06;hp=069d7100d2e5bed43c0217ed88c5fac4460d99b5;hpb=7a3bd641457666e10d0a47be9f22762e03defbf0;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs index 069d710..5dc3100 100644 --- a/ghc/compiler/rename/RnNames.lhs +++ b/ghc/compiler/rename/RnNames.lhs @@ -1,40 +1,47 @@ % -% (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 + getGlobalNames, exportsFromAvail ) where -IMP_Ubiq() - -import CmdLineOpts ( opt_SourceUnchanged ) -import HsSyn ( HsModule(..), HsDecl(..), FixityDecl(..), Fixity, Fake, InPat, IE(..), HsTyVar, - TyDecl, ClassDecl, InstDecl, DefaultDecl, ImportDecl(..), HsBinds, IfaceSig - ) -import HsBinds ( collectTopBinders ) -import HsImpExp ( ieName ) -import RdrHsSyn ( RdrNameHsDecl(..), RdrName(..), RdrNameIE(..), SYN_IE(RdrNameImportDecl), - SYN_IE(RdrNameHsModule), SYN_IE(RdrNameFixityDecl), - rdrNameOcc - ) -import RnHsSyn ( RenamedHsModule(..), RenamedFixityDecl(..) ) -import RnIfaces ( getInterfaceExports, getDeclBinders, checkUpToDate ) +#include "HsVersions.h" + +import CmdLineOpts ( DynFlag(..) ) + +import HsSyn ( HsModule(..), HsDecl(..), IE(..), ieName, ImportDecl(..), + ForeignDecl(..), ForKind(..), isDynamicExtName, + collectTopBinders + ) +import RdrHsSyn ( RdrNameIE, RdrNameImportDecl, + RdrNameHsModule, RdrNameHsDecl + ) +import RnIfaces ( getInterfaceExports, recordLocalSlurps ) +import RnHiFiles ( getTyClDeclBinders ) import RnEnv import RnMonad + import FiniteMap -import PrelMods -import UniqFM ( UniqFM, emptyUFM, addListToUFM_C, lookupUFM ) -import Bag ( Bag, bagToList ) -import Maybes ( maybeToBool, expectJust ) -import Name -import Pretty -import PprStyle ( PprStyle(..) ) -import Util ( panic, pprTrace ) +import PrelNames ( pRELUDE_Name, mAIN_Name, main_RDR_Unqual, isUnboundName ) +import UniqFM ( lookupUFM ) +import Bag ( bagToList ) +import Module ( ModuleName, moduleName, WhereFrom(..) ) +import NameSet +import Name ( Name, nameSrcLoc, nameOccName, nameEnvElts ) +import HscTypes ( Provenance(..), ImportReason(..), GlobalRdrEnv, + GenAvailInfo(..), AvailInfo, Avails, AvailEnv ) +import RdrName ( RdrName, rdrNameOcc, setRdrNameOcc ) +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} @@ -46,132 +53,190 @@ import Util ( panic, pprTrace ) %************************************************************************ \begin{code} -getGlobalNames :: RdrNameHsModule - -> RnMG (Maybe (ExportEnv, RnEnv, [AvailInfo])) - -- Nothing <=> no need to recompile - -getGlobalNames m@(HsModule this_mod _ exports imports _ _ mod_loc) - = fixRn (\ ~(rec_exp_fn, _) -> - - -- PROCESS LOCAL DECLS - -- Do these *first* so that the correct provenance gets - -- into the global name cache. - importsFromLocalDecls rec_exp_fn m `thenRn` \ (local_rn_env, local_mod_avails) -> - - -- PROCESS IMPORT DECLS - mapAndUnzipRn importsFromImportDecl all_imports - `thenRn` \ (imp_rn_envs, imp_avails_s) -> - - -- CHECK FOR EARLY EXIT - checkEarlyExit this_mod `thenRn` \ early_exit -> - if early_exit then - returnRn (junk_exp_fn, Nothing) - else - - -- COMBINE RESULTS - -- We put the local env first, so that a local provenance - -- "wins", even if a module imports itself. - foldlRn plusRnEnv emptyRnEnv imp_rn_envs `thenRn` \ imp_rn_env -> - plusRnEnv local_rn_env imp_rn_env `thenRn` \ rn_env -> - let - all_avails :: ModuleAvails - all_avails = foldr plusModuleAvails local_mod_avails imp_avails_s - local_avails = expectJust "getGlobalNames" (lookupModuleAvails local_mod_avails this_mod) - in - - -- PROCESS EXPORT LISTS - exportsFromAvail this_mod exports all_avails rn_env - `thenRn` \ (export_fn, export_env) -> - - returnRn (export_fn, Just (export_env, rn_env, local_avails)) - ) `thenRn` \ (_, result) -> - returnRn result +getGlobalNames :: Module -> RdrNameHsModule + -> RnMG (GlobalRdrEnv, -- Maps all in-scope things + GlobalRdrEnv, -- Maps just *local* things + ExportAvails) -- The exported stuff + +getGlobalNames this_mod (HsModule _ _ _ imports decls _ mod_loc) + = -- PROCESS LOCAL DECLS + -- Do these *first* so that the correct provenance gets + -- into the global name cache. + importsFromLocalDecls this_mod 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 + doptRn Opt_NoImplicitPrelude `thenRn` \ opt_no_prelude -> + let + all_imports = mk_prel_imports opt_no_prelude ++ imports + (source, ordinary) = partition is_source_import all_imports + is_source_import (ImportDecl _ ImportByUserSource _ _ _ _) = True + is_source_import other = False + + get_imports = importsFromImportDecl this_mod_name + in + mapAndUnzipRn get_imports ordinary `thenRn` \ (imp_gbl_envs1, imp_avails_s1) -> + mapAndUnzipRn get_imports 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) + in + + -- ALL DONE + returnRn (gbl_env, local_gbl_env, all_avails) where - junk_exp_fn = error "RnNames:export_fn" - - all_imports = prel_imports ++ imports - - prel_imports | this_mod == pRELUDE || - explicit_prelude_import = [] - - | otherwise = [ImportDecl pRELUDE - False {- Not qualified -} - Nothing {- No "as" -} - Nothing {- No import list -} - mod_loc] + this_mod_name = moduleName this_mod + + -- 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 no_prelude + | this_mod_name == pRELUDE_Name || + explicit_prelude_import || + no_prelude + = [] + + | 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} -checkEarlyExit mod - = if not opt_SourceUnchanged then - -- Source code changed; look no further - returnRn False +importsFromImportDecl :: ModuleName + -> RdrNameImportDecl + -> RnMG (GlobalRdrEnv, + ExportAvails) + +importsFromImportDecl this_mod_name (ImportDecl imp_mod_name from qual_only as_mod import_spec iloc) + = pushSrcLocRn iloc $ + getInterfaceExports imp_mod_name from `thenRn` \ (imp_mod, avails_by_module) -> + + if null avails_by_module 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 - -- Unchanged source; look further - -- We check for - -- (a) errors so far. These can arise if a module imports - -- something that's no longer exported by the imported module - -- (b) usage information up to date - checkErrsRn `thenRn` \ no_errs_so_far -> - checkUpToDate mod `thenRn` \ up_to_date -> - returnRn (no_errs_so_far && up_to_date) -\end{code} - -\begin{code} -importsFromImportDecl :: RdrNameImportDecl - -> RnMG (RnEnv, ModuleAvails) - - -- Check for "import M ()", and then don't even look at M. - -- This makes sense, and is actually rather useful for the Prelude. -importsFromImportDecl (ImportDecl mod qual as_mod (Just (False,[])) loc) - = returnRn (emptyRnEnv, emptyModuleAvails) - -importsFromImportDecl (ImportDecl mod qual as_mod import_spec loc) - = pushSrcLocRn loc $ - getInterfaceExports mod `thenRn` \ (avails, fixities) -> - filterImports mod import_spec avails `thenRn` \ filtered_avails -> let - filtered_avails' = [ Avail (set_name_prov n) (map set_name_prov ns) - | Avail n ns <- filtered_avails - ] - fixities' = [ (occ,fixity,provenance) | (occ,fixity) <- fixities ] + avails :: Avails + avails = [ avail | (mod_name, avails) <- avails_by_module, + mod_name /= this_mod_name, + avail <- avails ] + -- If the module exports anything defined in this module, just ignore it. + -- Reason: otherwise it looks as if there are two local definition sites + -- for the thing, and an error gets reported. Easiest thing is just to + -- filter them out up front. This situation only arises if a module + -- imports itself, or another module that imported it. (Necessarily, + -- this invoves a loop.) + -- + -- Tiresome consequence: if you say + -- module A where + -- import B( AType ) + -- type AType = ... + -- + -- module B( AType ) where + -- import {-# SOURCE #-} A( AType ) + -- + -- then you'll get a 'B does not export AType' message. Oh well. + + in + filterImports imp_mod_name from import_spec avails `thenRn` \ (filtered_avails, hides, 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 hides mk_prov filtered_avails + exports = mkExportAvails qual_mod unqual_imp gbl_env filtered_avails in - qualifyImports mod qual as_mod (ExportEnv filtered_avails' fixities') - where - set_name_prov name = setNameProvenance name provenance - provenance = Imported mod loc + returnRn (gbl_env, exports) \end{code} \begin{code} -importsFromLocalDecls rec_exp_fn (HsModule mod _ _ _ fix_decls decls _) - = foldlRn getLocalDeclBinders [] decls `thenRn` \ avails -> - mapRn fixityFromFixDecl fix_decls `thenRn` \ fixities -> - qualifyImports mod - False -- Not qualified - Nothing -- No "as M" part - (ExportEnv avails fixities) - where - newLocalName rdr_name loc - = newLocallyDefinedGlobalName mod (rdrNameOcc rdr_name) rec_exp_fn loc +importsFromLocalDecls this_mod decls + = mapRn (getLocalDeclBinders this_mod) decls `thenRn` \ avails_s -> + + let + avails = concat avails_s + + all_names :: [Name] -- All the defns; no dups eliminated + all_names = [name | avail <- avails, name <- availNames avail] - getLocalDeclBinders avails (ValD binds) - = mapRn do_one (bagToList (collectTopBinders binds)) `thenRn` \ val_avails -> - returnRn (val_avails ++ avails) + dups :: [[Name]] + (_, dups) = removeDups compare all_names + in + -- Check for duplicate definitions + mapRn_ (addErrRn . dupDeclErr) dups `thenRn_` + + -- Record that locally-defined things are available + recordLocalSlurps (availsToNameSet avails) `thenRn_` + + let + mod_name = moduleName this_mod + unqual_imp = True -- Want unqualified names + mk_prov n = LocalDef -- Provenance is local + hides = [] -- Hide nothing + gbl_env = mkGlobalRdrEnv mod_name unqual_imp hides mk_prov avails + exports = mkExportAvails mod_name unqual_imp gbl_env avails + in + returnRn (gbl_env, exports) + +--------------------------- +getLocalDeclBinders :: Module + -> RdrNameHsDecl -> RnMG Avails +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. + getTyClDeclBinders mod tycl_decl `thenRn` \ avail -> + returnRn [avail] + +getLocalDeclBinders mod (ValD binds) + = mapRn new (bagToList (collectTopBinders binds)) + where + new (rdr_name, loc) = newTopBinder mod rdr_name loc `thenRn` \ name -> + returnRn (Avail name) - getLocalDeclBinders avails decl - = getDeclBinders newLocalName decl `thenRn` \ avail -> - returnRn (avail : avails) +getLocalDeclBinders mod (ForD (ForeignDecl nm kind _ ext_nm _ loc)) + | binds_haskell_name kind + = newTopBinder mod nm loc `thenRn` \ name -> + returnRn [Avail name] - do_one (rdr_name, loc) - = newLocalName rdr_name loc `thenRn` \ name -> - returnRn (Avail name []) + | otherwise -- a foreign export + = returnRn [] + where + binds_haskell_name (FoImport _) = True + binds_haskell_name FoLabel = True + binds_haskell_name FoExport = isDynamicExtName ext_nm + +getLocalDeclBinders mod (FixD _) = returnRn [] +getLocalDeclBinders mod (DeprecD _) = returnRn [] +getLocalDeclBinders mod (DefD _) = returnRn [] +getLocalDeclBinders mod (InstD _) = returnRn [] +getLocalDeclBinders mod (RuleD _) = returnRn [] \end{code} + %************************************************************************ %* * \subsection{Filtering imports} @@ -182,58 +247,90 @@ importsFromLocalDecls rec_exp_fn (HsModule mod _ _ _ fix_decls decls _) available, and filters it through the import spec (if any). \begin{code} -filterImports :: Module - -> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hidin - -> [AvailInfo] -- What's available - -> RnMG [AvailInfo] -- What's actually imported - -- Complains if import spec mentions things the - -- module doesn't export - -filterImports mod Nothing imports - = returnRn imports - -filterImports mod (Just (want_hiding, import_items)) avails - = -- Check that each import item mentions things that are actually available - mapRn check_import_item import_items `thenRn_` - - -- Return filtered environment; no need to filter fixities - returnRn (map new_avail avails) - +filterImports :: ModuleName -- The module being imported + -> WhereFrom -- Tells whether it's a {-# SOURCE #-} import + -> 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 from Nothing imports + = returnRn (imports, [], emptyNameSet) + +filterImports mod from (Just (want_hiding, import_items)) total_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 (total_avails, item_avails, emptyNameSet) + else + -- Just item_avails imported; nothing to be hidden + returnRn (item_avails, [], explicits) where - import_fm :: FiniteMap OccName RdrNameIE - import_fm = listToFM [(ieOcc ie, ie) | ie <- import_items] - - avail_fm :: FiniteMap OccName AvailInfo - avail_fm = listToFM [(nameOccName name, avail) | avail@(Avail name ns) <- avails] - - new_avail NotAvailable = NotAvailable - new_avail avail@(Avail name _) - | not in_import_items && want_hiding = avail - | not in_import_items && not want_hiding = NotAvailable - | in_import_items && want_hiding = NotAvailable - | in_import_items && not want_hiding = filtered_avail - where - maybe_import_item = lookupFM import_fm (nameOccName name) - in_import_items = maybeToBool maybe_import_item - Just import_item = maybe_import_item - filtered_avail = filterAvail import_item avail - - check_import_item :: RdrNameIE -> RnMG () - check_import_item item - = checkRn (maybeToBool maybe_matching_avail && sub_names_ok item avail) - (badImportItemErr mod item) - where - item_name = ieOcc item - maybe_matching_avail = lookupFM avail_fm item_name - Just avail = maybe_matching_avail - - sub_names_ok (IEVar _) _ = True - sub_names_ok (IEThingAbs _) _ = True - sub_names_ok (IEThingAll _) _ = True - sub_names_ok (IEThingWith _ wanted) (Avail _ has) = all ((`elem` has_list) . rdrNameOcc) wanted - where - has_list = map nameOccName has - sub_names_ok other1 other2 = False + 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 = addErrRn (badImportItemErr mod from 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} @@ -244,197 +341,178 @@ filterImports mod (Just (want_hiding, import_items)) avails %* * %************************************************************************ -@qualifyImports@ takes the @ExportEnv@ after filtering through the import spec -of an import decl, and deals with producing an @RnEnv@ with the -right qaulified names. It also turns the @Names@ in the @ExportEnv@ into -fully fledged @Names@. - \begin{code} -qualifyImports :: Module -- Improrted module - -> Bool -- True <=> qualified import - -> Maybe Module -- Optional "as M" part - -> ExportEnv -- What's imported - -> RnMG (RnEnv, ModuleAvails) - -qualifyImports this_mod qual as_mod (ExportEnv avails fixities) - = -- Make the qualified-name environments, checking of course for clashes - foldlRn add_name emptyNameEnv avails `thenRn` \ name_env -> - foldlRn (add_fixity name_env) emptyFixityEnv fixities `thenRn` \ fixity_env -> - - -- Deal with the "qualified" part; if not qualifies then add unqualfied bindings - if qual then - returnRn (RnEnv name_env fixity_env, mod_avail_env) - else - returnRn (RnEnv (unQualify name_env) (unQualify fixity_env), mod_avail_env) +mkEmptyExportAvails :: ModuleName -> ExportAvails +mkEmptyExportAvails mod_name = (unitFM mod_name [], emptyUFM) +mkExportAvails :: ModuleName -> Bool -> GlobalRdrEnv -> [AvailInfo] -> ExportAvails +mkExportAvails mod_name unqual_imp gbl_env avails + = (mod_avail_env, entity_avail_env) where - mod_avail_env = unitFM this_mod avails - - add_name name_env NotAvailable = returnRn name_env - add_name name_env (Avail n ns) = foldlRn add_one name_env (n : ns) - - add_one :: NameEnv -> Name -> RnMG NameEnv - add_one env name = addOneToNameEnvRn env (Qual this_mod occ_name) name - where - occ_name = nameOccName name - - add_fixity name_env fixity_env (occ_name, fixity, provenance) - | maybeToBool (lookupFM name_env qual_name) -- The name is imported - = addOneToFixityEnvRn fixity_env qual_name (fixity,provenance) - | otherwise -- It ain't imported - = returnRn fixity_env - where - qual_name = Qual this_mod occ_name -\end{code} + mod_avail_env = unitFM mod_name unqual_avails -unQualify adds an Unqual binding for every existing Qual binding. + -- 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 -\begin{code} -unQualify :: FiniteMap RdrName elt -> FiniteMap RdrName elt -unQualify fm = addListToFM fm [(Unqual occ, elt) | (Qual _ occ, elt) <- fmToList fm] -\end{code} + unqual_avails | not unqual_imp = [] -- Short cut when no unqualified imports + | otherwise = mapMaybe prune avails -%************************************************************************ -%* * -\subsection{Local declarations} -%* * -%************************************************************************ + 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 gbl_env n -\begin{code} -fixityFromFixDecl :: RdrNameFixityDecl -> RnMG (OccName, Fixity, Provenance) + entity_avail_env = listToUFM [ (name,avail) | avail <- avails, + name <- availNames avail] -fixityFromFixDecl (FixityDecl rdr_name fixity loc) - = returnRn (rdrNameOcc rdr_name, fixity, LocalDef (panic "export-flag") loc) +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} %* * %************************************************************************ -The @AvailEnv@ type is just used internally in @exportsFromAvail@. -When exporting we need to combine the availabilities for a particular -exported thing, and we also need to check for name clashes -- that -is: two exported things must have different @OccNames@. - -\begin{code} -type AvailEnv = FiniteMap OccName (RdrNameIE, AvailInfo) - -- The FM maps each OccName to the RdrNameIE that gave rise to it, - -- for error reporting, as well as to its AvailInfo - -emptyAvailEnv = emptyFM +Processing the export list. -unitAvailEnv :: RdrNameIE -> AvailInfo -> AvailEnv -unitAvailEnv ie NotAvailable - = emptyFM -unitAvailEnv ie avail@(Avail n ns) - = unitFM (nameOccName n) (ie,avail) +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). -plusAvailEnv a1 a2 - = mapRn (addErrRn.availClashErr) (conflictsFM bad_avail a1 a2) `thenRn_` - returnRn (plusFM_C plus_avail a1 a2) +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... -listToAvailEnv :: RdrNameIE -> [AvailInfo] -> RnM s d AvailEnv -listToAvailEnv ie items - = foldlRn plusAvailEnv emptyAvailEnv (map (unitAvailEnv ie) items) +\begin{code} +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 -bad_avail (ie1,Avail n1 _) (ie2,Avail n2 _) = n1 /= n2 -- Same OccName, different Name -plus_avail (ie1,a1) (ie2,a2) = (ie1, a1 `plusAvail` a2) -\end{code} +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 -\begin{code} -exportsFromAvail :: Module +exportsFromAvail :: ModuleName -> Maybe [RdrNameIE] -- Export spec - -> ModuleAvails - -> RnEnv - -> RnMG (Name -> ExportFlag, ExportEnv) + -> 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 all_avails rn_env - = exportsFromAvail this_mod (Just [IEModuleContents this_mod]) all_avails rn_env - -exportsFromAvail this_mod (Just export_items) all_avails (RnEnv name_env fixity_env) - = mapRn exports_from_item export_items `thenRn` \ avail_envs -> - foldlRn plusAvailEnv emptyAvailEnv avail_envs `thenRn` \ export_avail_env -> +exportsFromAvail this_mod Nothing 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_Unqual] + -- 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 = map snd (eltsFM export_avail_env) - export_fixities = mk_exported_fixities (availsToNameSet export_avails) - export_fn = mk_export_fn export_avails + export_avails :: [AvailInfo] + export_avails = nameEnvElts export_avail_map in - returnRn (export_fn, ExportEnv export_avails export_fixities) + returnRn export_avails where - full_avail_env :: UniqFM AvailInfo - full_avail_env = addListToUFM_C plusAvail emptyUFM - [(name,avail) | avail@(Avail name _) <- concat (eltsFM all_avails)] - -- NB: full_avail_env won't contain bindings for data constructors and class ops, - -- which is right and proper; attempts to export them on their own will provoke an error - - exports_from_item :: RdrNameIE -> RnMG AvailEnv - exports_from_item ie@(IEModuleContents mod) - = case lookupFM all_avails mod of - Nothing -> failWithRn emptyAvailEnv (modExportErr mod) - Just avails -> addOccurrenceNames Compulsory [n | Avail n _ <- avails] `thenRn_` - listToAvailEnv ie avails - - exports_from_item ie - | not (maybeToBool maybe_in_scope) - = failWithRn emptyAvailEnv (unknownNameErr (ieName ie)) - -#ifdef DEBUG - -- I can't see why this should ever happen; if the thing is in scope - -- at all it ought to have some availability - | not (maybeToBool maybe_avail) - = pprTrace "exportsFromAvail: curious Nothing:" (ppr PprDebug name) - returnRn emptyAvailEnv -#endif - - | not enough_avail - = failWithRn emptyAvailEnv (exportItemErr ie export_avail) - - | otherwise -- Phew! It's OK! - = addOccurrenceName Compulsory name `thenRn_` - returnRn (unitAvailEnv ie export_avail) - where - maybe_in_scope = lookupNameEnv name_env (ieName ie) - Just name = maybe_in_scope - maybe_avail = lookupUFM full_avail_env name - Just avail = maybe_avail - export_avail = filterAvail ie avail - enough_avail = case export_avail of {NotAvailable -> False; other -> True} - - -- We export a fixity iff we export a thing with the same (qualified) RdrName - mk_exported_fixities :: NameSet -> [(OccName, Fixity, Provenance)] - mk_exported_fixities exports - = [ (rdrNameOcc rdr_name, fixity, prov) - | (rdr_name, (fixity, prov)) <- fmToList fixity_env, - export_fixity name_env exports rdr_name - ] - -mk_export_fn :: [AvailInfo] -> (Name -> ExportFlag) -mk_export_fn avails - = \name -> if name `elemNameSet` exported_names - then Exported - else NotExported + exports_from_item :: 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 + = lookupSrcName global_name_env (ieName ie) `thenRn` \ name -> + + -- See what's available in the current environment + case lookupUFM entity_avail_env name of { + Nothing -> -- Presumably this happens because lookupSrcName didn't find + -- the name and returned an unboundName, which won't be in + -- the entity_avail_env, of course + WARN( not (isUnboundName name), ppr name ) + returnRn acc ; + + Just avail -> + + -- Filter out the bits we want + case filterAvail ie avail of { + Nothing -> -- Not enough availability + failWithRn acc (exportItemErr ie) ; + + Just export_avail -> + + -- 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) + }} + + + +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 - exported_names :: NameSet - exported_names = availsToNameSet avails - -export_fixity :: NameEnv -> NameSet -> RdrName -> Bool -export_fixity name_env exports (Unqual _) - = False -- The qualified fixity is always there as well -export_fixity name_env exports rdr_name@(Qual _ occ) - = case lookupFM name_env rdr_name of - Just fixity_name -> fixity_name `elemNameSet` exports - -- Check whether the exported thing is - -- the one to which the fixity attaches - other -> False -- Not even in scope -\end{code} - + 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 +\end{code} %************************************************************************ %* * @@ -443,24 +521,48 @@ export_fixity name_env exports rdr_name@(Qual _ occ) %************************************************************************ \begin{code} -ieOcc ie = rdrNameOcc (ieName ie) - -badImportItemErr mod ie sty - = ppSep [ppStr "Module", pprModule sty mod, ppStr "does not export", ppr sty ie] - -modExportErr mod sty - = ppCat [ ppStr "Unknown module in export list: module", ppPStr mod] - -exportItemErr export_item NotAvailable sty - = ppSep [ ppStr "Export item not in scope:", ppr sty export_item ] - -exportItemErr export_item avail sty - = ppHang (ppStr "Export item not fully in scope:") - 4 (ppAboves [ppCat [ppStr "Wanted: ", ppr sty export_item], - ppCat [ppStr "Available: ", ppr sty (ieOcc export_item), pprAvail sty avail]]) - -availClashErr (occ_name, ((ie1,avail1), (ie2,avail2))) sty - = ppHang (ppCat [ppStr "Conflicting exports for local name: ", ppr sty occ_name]) - 4 (ppAboves [ppr sty ie1, ppr sty ie2]) +badImportItemErr mod from ie + = sep [ptext SLIT("Module"), quotes (ppr mod), source_import, + ptext SLIT("does not export"), quotes (ppr ie)] + where + source_import = case from of + ImportByUserSource -> 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")] \end{code} -