X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnNames.lhs;h=fa5b376210af71988698b08ce3dfe36c6e0e3bcb;hb=b79fa717a965a0808bb74f34a14ba86e080193c5;hp=5db5ead0fbd2bbacc1a9bab81cb8eac9fae8ff4f;hpb=8f7ac3fe40d3d55743b824deab655d0797a1c55f;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs index 5db5ead..fa5b376 100644 --- a/ghc/compiler/rename/RnNames.lhs +++ b/ghc/compiler/rename/RnNames.lhs @@ -1,40 +1,53 @@ % -% (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 ) where -IMP_Ubiq() +#include "HsVersions.h" + +import CmdLineOpts ( opt_NoImplicitPrelude, opt_WarnDuplicateExports, + opt_SourceUnchanged, opt_WarnUnusedBinds + ) -import CmdLineOpts ( opt_SourceUnchanged, opt_NoImplicitPrelude ) -import HsSyn ( HsModule(..), HsDecl(..), FixityDecl(..), Fixity, Fake, InPat, IE(..), HsTyVar, - TyDecl, ClassDecl, InstDecl, DefaultDecl, ImportDecl(..), HsBinds, IfaceSig +import HsSyn ( HsModule(..), HsDecl(..), TyClDecl(..), + IE(..), ieName, + ForeignDecl(..), ForKind(..), isDynamic, + FixitySig(..), Sig(..), ImportDecl(..), + collectTopBinders + ) +import RdrHsSyn ( RdrNameIE, RdrNameImportDecl, + RdrNameHsModule, RdrNameHsDecl ) -import HsBinds ( collectTopBinders ) -import HsImpExp ( ieName ) -import RdrHsSyn ( RdrNameHsDecl(..), RdrName(..), RdrNameIE(..), SYN_IE(RdrNameImportDecl), - SYN_IE(RdrNameHsModule), SYN_IE(RdrNameFixityDecl), - rdrNameOcc +import RnIfaces ( getInterfaceExports, getDeclBinders, getDeclSysBinders, + recordSlurp, checkUpToDate ) -import RnHsSyn ( RenamedHsModule(..), RenamedFixityDecl(..) ) -import RnIfaces ( getInterfaceExports, getDeclBinders, checkUpToDate ) 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 PrelInfo ( main_RDR ) +import UniqFM ( lookupUFM ) +import Bag ( bagToList ) +import Maybes ( maybeToBool ) +import Module ( ModuleName, mkThisModule, pprModuleName, WhereFrom(..) ) +import NameSet +import Name ( Name, ExportFlag(..), ImportReason(..), Provenance(..), + isLocallyDefined, setNameProvenance, + nameOccName, getSrcLoc, pprProvenance, getNameProvenance + ) +import RdrName ( RdrName, rdrNameOcc, mkRdrQual, mkRdrUnqual, isQual ) +import SrcLoc ( SrcLoc ) +import NameSet ( elemNameSet, emptyNameSet ) +import Outputable +import Unique ( getUnique ) +import Util ( removeDups, equivClassesByUniq, sortLt ) +import List ( partition ) \end{code} @@ -47,45 +60,120 @@ 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) + -> RnMG (Maybe (ExportEnv, + GlobalRdrEnv, + FixityEnv, -- Fixities for local decls only + NameEnv AvailInfo -- 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 (\ ~(rec_gbl_env, rec_exported_avails, _) -> + + let + rec_unqual_fn :: Name -> Bool -- Is this chap in scope unqualified? + rec_unqual_fn = unQualInScope rec_gbl_env + + rec_exp_fn :: Name -> ExportFlag + rec_exp_fn = mk_export_fn (availsToNameSet rec_exported_avails) + in + 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) -> + + -- 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) + 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. + checkEarlyExit this_mod `thenRn` \ up_to_date -> + if up_to_date then + 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_` - -- 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 + exportsFromAvail this_mod exports all_avails gbl_env + `thenRn` \ exported_avails -> + + -- DONE + 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 -> + + -- DEAL WITH FIXITIES + fixitiesFromLocalDecls gbl_env decls `thenRn` \ local_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 + ] + in + traceRn (text "fixity env" <+> vcat (map ppr (nameEnvElts local_fixity_env))) `thenRn_` + + --- TIDY UP + let + export_env = ExportEnv exported_avails exported_fixities + (_, global_avail_env) = all_avails + in + returnRn (Just (export_env, gbl_env, local_fixity_env, global_avail_env)) + } where junk_exp_fn = error "RnNames:export_fn" @@ -94,87 +182,178 @@ getGlobalNames m@(HsModule this_mod _ exports imports _ _ 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} checkEarlyExit mod - = if not opt_SourceUnchanged then - -- Source code changed; look no further + = checkErrsRn `thenRn` \ no_errs_so_far -> + if not no_errs_so_far then + -- Found errors already, so exit now + returnRn True + else + + traceRn (text "Considering whether compilation is required...") `thenRn_` + if not opt_SourceUnchanged then + -- Source code changed and no errors yet... carry on + traceRn (nest 4 (text "source file changed or recompilation check turned off")) `thenRn_` returnRn False 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) + + -- Unchanged source, and no errors yet; see if usage info + -- up to date, and exit if so + checkUpToDate mod `thenRn` \ up_to_date -> + (if up_to_date + then putDocRn (text "Compilation IS NOT required") + else returnRn ()) `thenRn_` + returnRn up_to_date \end{code} - \begin{code} -importsFromImportDecl :: RdrNameImportDecl - -> RnMG (RnEnv, ModuleAvails) +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) -> -importsFromImportDecl (ImportDecl mod qual_only as_mod import_spec loc) - = pushSrcLocRn loc $ - getInterfaceExports mod `thenRn` \ (avails, fixities) -> - filterImports mod import_spec avails `thenRn` \ filtered_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 - filtered_avails' = [ Avail (set_name_prov n) (map set_name_prov ns) - | Avail n ns <- filtered_avails - ] - fixities' = [ (occ,fixity,provenance) | (occ,fixity) <- fixities ] + improve_prov name = + setNameProvenance name (NonLocalDef (UserImport imp_mod iloc (is_explicit name)) + (is_unqual name)) + is_explicit name = name `elemNameSet` explicits in - qualifyImports mod - True -- Want qualified names + qualifyImports imp_mod_name (not qual_only) -- Maybe want unqualified names - as_mod - (ExportEnv filtered_avails' fixities') - where - set_name_prov name = setNameProvenance name provenance - provenance = Imported mod loc + as_mod hides + filtered_avails improve_prov + `thenRn` \ (rdr_name_env, mod_avails) -> + + returnRn (rdr_name_env, mod_avails) \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 -- Don't want qualified names +importsFromLocalDecls mod_name rec_exp_fn decls + = mapRn (getLocalDeclBinders newLocalName) 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] + + dups :: [[Name]] + (_, dups) = removeDups compare all_names + in + -- Check for duplicate definitions + mapRn_ (addErrRn . dupDeclErr) dups `thenRn_` + + -- Record that locally-defined things are available + mapRn_ (recordSlurp Nothing) avails `thenRn_` + + -- Build the environment + qualifyImports mod_name True -- Want unqualified names - Nothing -- No "as M" part - (ExportEnv avails fixities) + Nothing -- no 'as M' + [] -- Hide nothing + avails + (\n -> n) + + where + 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 + -> RnMG Avails +getLocalDeclBinders new_name (ValD binds) + = mapRn do_one (bagToList (collectTopBinders binds)) + where + do_one (rdr_name, loc) = new_name rdr_name loc `thenRn` \ name -> + returnRn (Avail name) + +getLocalDeclBinders new_name decl + = getDeclBinders new_name decl `thenRn` \ maybe_avail -> + case maybe_avail of + Nothing -> returnRn [] -- Instance decls and suchlike + Just avail -> getDeclSysBinders new_sys_name decl `thenRn_` + returnRn [avail] where - newLocalName rdr_name loc - = newLocallyDefinedGlobalName mod (rdrNameOcc rdr_name) rec_exp_fn loc + -- 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 - getLocalDeclBinders avails (ValD binds) - = mapRn do_one (bagToList (collectTopBinders binds)) `thenRn` \ val_avails -> - returnRn (val_avails ++ avails) +fixitiesFromLocalDecls :: GlobalRdrEnv -> [RdrNameHsDecl] -> RnMG FixityEnv +fixitiesFromLocalDecls gbl_env decls + = foldlRn getFixities emptyNameEnv decls + where + getFixities :: FixityEnv -> RdrNameHsDecl -> RnMG FixityEnv + getFixities acc (FixD fix) + = fix_decl acc fix + + 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 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 + | otherwise -> returnRn acc ; + + Just (name:_) -> - getLocalDeclBinders avails decl - = getDeclBinders newLocalName decl `thenRn` \ avail -> - returnRn (avail : avails) + -- Check for duplicate fixity decl + case lookupNameEnv acc name of { + Just (FixitySig _ _ loc') -> addErrRn (dupFixityDecl rdr_name loc loc') + `thenRn_` returnRn acc ; - do_one (rdr_name, loc) - = newLocalName rdr_name loc `thenRn` \ name -> - returnRn (Avail name []) + Nothing -> returnRn (addToNameEnv acc name (FixitySig name fixity loc)) + }} \end{code} %************************************************************************ @@ -187,58 +366,77 @@ 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 :: 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) + 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 + = returnRn (imports, [], emptyNameSet) 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) - + = mapMaybeRn check_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 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 <- 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. + + check_item item@(IEModuleContents _) + = addErrRn (badImportItemErr mod item) `thenRn_` + returnRn Nothing + + check_item item + | not (maybeToBool maybe_in_import_avails) || + not (maybeToBool maybe_filtered_avail) + = addErrRn (badImportItemErr mod item) `thenRn_` + returnRn Nothing + + | dodgy_import = addWarnRn (dodgyImportWarn mod item) `thenRn_` + returnRn (Just (filtered_avail, explicits)) + + | otherwise = returnRn (Just (filtered_avail, explicits)) + + 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 + 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} @@ -251,206 +449,202 @@ 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 +right qualified names. It also turns the @Names@ in the @ExportEnv@ into fully fledged @Names@. \begin{code} -qualifyImports :: Module -- Imported module - -> Bool -- True <=> want qualified import - -> Bool -- True <=> want unqualified import - -> Maybe Module -- Optional "as M" part - -> ExportEnv -- What's imported - -> RnMG (RnEnv, ModuleAvails) - -qualifyImports this_mod qual_imp unqual_imp 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 -> - returnRn (RnEnv name_env fixity_env, mod_avail_env) +qualifyImports :: ModuleName -- Imported module + -> Bool -- True <=> want unqualified import + -> 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 + = + -- 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 + -- Add the things that are available + name_env1 = foldl add_avail emptyRdrEnv avails + + -- Delete things that are hidden + name_env2 = foldl del_avail name_env1 hides + + -- Create the export-availability info + export_avails = mkExportAvails qual_mod unqual_imp name_env2 avails + in + returnRn (name_env2, export_avails) + where qual_mod = case as_mod of Nothing -> this_mod Just another_name -> another_name - mod_avail_env = unitFM qual_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 = add_to_env addOneToNameEnvRn env occ_name name - where - occ_name = nameOccName name - - add_to_env add_fn env occ thing | qual_imp && unqual_imp = both - | qual_imp = qual_only - | unqual_imp = unqual_only - where - unqual_only = add_fn env (Unqual occ) thing - qual_only = add_fn env (Qual qual_mod occ) thing - both = unqual_only `thenRn` \ env' -> - add_fn env' (Qual qual_mod occ) thing - - add_fixity name_env fixity_env (occ_name, fixity, provenance) - | maybeToBool (lookupFM name_env rdr_name) -- It's imported - = add_to_env addOneToFixityEnvRn fixity_env occ_name (fixity,provenance) - | otherwise -- It ain't imported - = returnRn fixity_env + 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 - -- rdr_name is a name by which the thing is guaranteed to be known, - -- *if it is imported at all* - rdr_name | qual_imp = Qual qual_mod occ_name - | otherwise = Unqual occ_name + env1 = addOneToGlobalRdrEnv env (mkRdrQual qual_mod occ) better_name + env2 = addOneToGlobalRdrEnv env1 (mkRdrUnqual occ) better_name + occ = nameOccName name + better_name = improve_prov name + + del_avail env avail = foldl delOneFromGlobalRdrEnv env rdr_names + where + rdr_names = map (mkRdrUnqual . nameOccName) (availNames avail) \end{code} -unQualify adds an Unqual binding for every existing Qual binding. - -\begin{code} -unQualify :: FiniteMap RdrName elt -> FiniteMap RdrName elt -unQualify fm = addListToFM fm [(Unqual occ, elt) | (Qual _ occ, elt) <- fmToList fm] -\end{code} %************************************************************************ %* * -\subsection{Local declarations} +\subsection{Export list processing} %* * %************************************************************************ +Processing the export list. -\begin{code} -fixityFromFixDecl :: RdrNameFixityDecl -> RnMG (OccName, Fixity, Provenance) - -fixityFromFixDecl (FixityDecl rdr_name fixity loc) - = returnRn (rdrNameOcc rdr_name, fixity, LocalDef (panic "export-flag") loc) -\end{code} - - -%************************************************************************ -%* * -\subsection{Export list processing -%* * -%************************************************************************ +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). -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@. +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 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 +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 + NameEnv AvailInfo) -- The accumulated exported stuff, kept in an env + -- so we can common-up related AvailInfos -emptyAvailEnv = emptyFM +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 -unitAvailEnv :: RdrNameIE -> AvailInfo -> AvailEnv -unitAvailEnv ie NotAvailable - = emptyFM -unitAvailEnv ie avail@(Avail n ns) - = unitFM (nameOccName n) (ie,avail) -plusAvailEnv a1 a2 - = mapRn (addErrRn.availClashErr) (conflictsFM bad_avail a1 a2) `thenRn_` - returnRn (plusFM_C plus_avail a1 a2) - -listToAvailEnv :: RdrNameIE -> [AvailInfo] -> RnM s d AvailEnv -listToAvailEnv ie items - = foldlRn plusAvailEnv emptyAvailEnv (map (unitAvailEnv ie) items) - -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} - - -\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] + -- 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) -> 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 + exports_from_item :: ExportAccum -> RdrNameIE -> RnMG ExportAccum + + exports_from_item acc@(mods, occs, avails) ie@(IEModuleContents mod) + | mod `elem` mods -- Duplicate export of M + = warnCheckRn opt_WarnDuplicateExports + (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 add_avail avails mod_avails + in + returnRn (mod:mods, occs', avails') + + exports_from_item acc@(mods, occs, avails) ie | not (maybeToBool maybe_in_scope) - = failWithRn emptyAvailEnv (unknownNameErr (ieName ie)) + = failWithRn acc (unknownNameErr (ieName ie)) + + | not (null dup_names) + = addNameClashErrRn rdr_name (name: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 PprDebug name) - returnRn emptyAvailEnv + = pprTrace "exportsFromAvail: curious Nothing:" (ppr name) + returnRn acc #endif | not enough_avail - = failWithRn emptyAvailEnv (exportItemErr ie export_avail) + = 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) - | 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 + rdr_name = ieName ie + maybe_in_scope = lookupFM global_name_env rdr_name + Just (name: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 + +add_avail avails avail = addToNameEnv_C plusAvail avails (availName avail) avail + +check_occs :: RdrNameIE -> ExportOccMap -> AvailInfo -> RnMG ExportOccMap +check_occs ie occs avail + = foldlRn check occs (availNames avail) + where + check occs name + = case lookupFM occs name_occ of + Nothing -> returnRn (addToFM occs name_occ (name, ie)) + Just (name', ie') + | name == name' -> -- Duplicate export + warnCheckRn opt_WarnDuplicateExports + (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 -> ExportFlag) +mk_export_fn exported_names = \name -> if name `elemNameSet` exported_names then Exported else NotExported - 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} - +\end{code} %************************************************************************ %* * @@ -459,24 +653,53 @@ export_fixity name_env exports rdr_name@(Qual _ occ) %************************************************************************ \begin{code} -ieOcc ie = rdrNameOcc (ieName ie) +badImportItemErr mod ie + = sep [ptext SLIT("Module"), quotes (pprModuleName mod), + ptext SLIT("does not export"), quotes (ppr ie)] + +dodgyImportWarn mod (IEThingAll tc) + = sep [ptext SLIT("Module") <+> quotes (pprModuleName mod) + <+> ptext SLIT("exports") <+> quotes (ppr tc), + ptext SLIT("with no constructors/class operations;"), + ptext SLIT("yet it is imported with a (..)")] + +modExportErr 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)] + +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 pp sorted_ns))] + where + sorted_ns = sortLt occ'ed_before (n:ns) -badImportItemErr mod ie sty - = ppSep [ppStr "Module", pprModule sty mod, ppStr "does not export", ppr sty ie] + occ'ed_before a b = LT == compare (getSrcLoc a) (getSrcLoc b) -modExportErr mod sty - = ppCat [ ppStr "Unknown module in export list: module", ppPStr mod] + pp n = pprProvenance (getNameProvenance n) -exportItemErr export_item NotAvailable sty - = ppSep [ ppStr "Export item not in scope:", ppr sty export_item ] +dupExportWarn occ_name ie1 ie2 + = hsep [quotes (ppr occ_name), + ptext SLIT("is exported by"), quotes (ppr ie1), + ptext SLIT("and"), quotes (ppr ie2)] -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]]) +dupModuleExport mod + = hsep [ptext SLIT("Duplicate"), + quotes (ptext SLIT("Module") <+> pprModuleName mod), + ptext SLIT("in export list")] -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]) -\end{code} +unusedFixityDecl rdr_name fixity + = hsep [ptext SLIT("Unused fixity declaration for"), quotes (ppr rdr_name)] +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}