%
-% (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 )
-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(..), IE(..), ieName, 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,
+ recordLocalSlurps, checkModUsage, findAndReadIface, outOfDate
)
-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 ( pRELUDE_Name, mAIN_Name, main_RDR )
+import UniqFM ( lookupUFM )
+import Bag ( bagToList )
+import Module ( ModuleName, mkThisModule, pprModuleName, WhereFrom(..) )
+import NameSet
+import Name ( Name, ExportFlag(..), ImportReason(..), Provenance(..),
+ setNameProvenance,
+ nameOccName, getSrcLoc, pprProvenance, getNameProvenance,
+ nameEnvElts
+ )
+import RdrName ( RdrName, rdrNameOcc, setRdrNameOcc, mkRdrQual, mkRdrUnqual, isQual, isUnqual )
+import OccName ( setOccNameSpace, dataName )
+import NameSet ( elemNameSet, emptyNameSet )
+import Outputable
+import Maybes ( maybeToBool, catMaybes, mapMaybe )
+import UniqFM ( emptyUFM, listToUFM )
+import Util ( removeDups, sortLt )
+import List ( partition )
\end{code}
\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
+ -> RnMG (Maybe (GlobalRdrEnv, -- Maps all in-scope things
+ GlobalRdrEnv, -- Maps just *local* things
+ Avails, -- The exported stuff
+ AvailEnv, -- Maps a name to its parent AvailInfo
+ -- Just for in-scope things only
+ Maybe ParsedIface -- The old interface file, if any
+ ))
+ -- Nothing => no need to recompile
+
+getGlobalNames (HsModule this_mod _ exports imports decls _ mod_loc)
+ = -- These two fix-loops are to get the right
+ -- provenance information into a Name
+ fixRn ( \ ~(Just (rec_gbl_env, _, rec_export_avails, _, _)) ->
+
+ let
+ rec_unqual_fn :: Name -> Bool -- Is this chap in scope unqualified?
+ rec_unqual_fn = unQualInScope rec_gbl_env
+
+ rec_exp_fn :: Name -> ExportFlag
+ rec_exp_fn = mk_export_fn (availsToNameSet rec_export_avails)
+ in
+
+ -- PROCESS LOCAL DECLS
+ -- Do these *first* so that the correct provenance gets
+ -- into the global name cache.
+ importsFromLocalDecls this_mod rec_exp_fn decls
+ `thenRn` \ (local_gbl_env, local_mod_avails) ->
+
+ -- PROCESS IMPORT DECLS
+ -- Do the non {- SOURCE -} ones first, so that we get a helpful
+ -- warning for {- SOURCE -} ones that are unnecessary
+ let
+ (source, ordinary) = partition is_source_import all_imports
+ is_source_import (ImportDecl _ ImportByUserSource _ _ _ _) = True
+ is_source_import other = False
+ in
+ mapAndUnzipRn (importsFromImportDecl rec_unqual_fn) ordinary
+ `thenRn` \ (imp_gbl_envs1, imp_avails_s1) ->
+ mapAndUnzipRn (importsFromImportDecl rec_unqual_fn) source
+ `thenRn` \ (imp_gbl_envs2, imp_avails_s2) ->
+
+ -- COMBINE RESULTS
+ -- We put the local env second, so that a local provenance
+ -- "wins", even if a module imports itself.
+ let
+ gbl_env :: GlobalRdrEnv
+ imp_gbl_env = foldr plusGlobalRdrEnv emptyRdrEnv (imp_gbl_envs2 ++ imp_gbl_envs1)
+ gbl_env = imp_gbl_env `plusGlobalRdrEnv` local_gbl_env
+
+ all_avails :: ExportAvails
+ all_avails = foldr plusExportAvails local_mod_avails (imp_avails_s2 ++ imp_avails_s1)
+ (_, global_avail_env) = all_avails
+ in
+
+ -- TRY FOR EARLY EXIT
+ -- We can't go for an early exit before this because we have to check
+ -- for name clashes. Consider:
+ --
+ -- module A where module B where
+ -- import B h = True
+ -- f = h
+ --
+ -- Suppose I've compiled everything up, and then I add a
+ -- new definition to module B, that defines "f".
+ --
+ -- Then I must detect the name clash in A before going for an early
+ -- exit. The early-exit code checks what's actually needed from B
+ -- to compile A, and of course that doesn't include B.f. That's
+ -- why we wait till after the plusEnv stuff to do the early-exit.
+
+ -- Check For eacly exit
+ checkErrsRn `thenRn` \ no_errs_so_far ->
+ if not no_errs_so_far then
+ -- Found errors already, so exit now
+ returnRn Nothing
+ else
+ checkEarlyExit this_mod `thenRn` \ (up_to_date, old_iface) ->
+ if up_to_date then
+ -- Interface files are sufficiently unchanged
+ putDocRn (text "Compilation IS NOT required") `thenRn_`
+ returnRn 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 gbl_env,
+ isQual rdr_name]) `thenRn_`
+
+ -- PROCESS EXPORT LISTS
+ exportsFromAvail this_mod exports all_avails gbl_env `thenRn` \ export_avails ->
+
+
+ -- ALL DONE
+ returnRn (Just (gbl_env, local_gbl_env, export_avails, global_avail_env, old_iface))
+ )
where
- junk_exp_fn = error "RnNames:export_fn"
-
all_imports = prel_imports ++ imports
-- NB: opt_NoImplicitPrelude is slightly different to import Prelude ();
-- because the former doesn't even look at Prelude.hi for instance declarations,
-- whereas the latter does.
- prel_imports | this_mod == pRELUDE ||
+ 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
- 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)
+checkEarlyExit mod_name
+ = traceRn (text "Considering whether compilation is required...") `thenRn_`
+
+ -- Read the old interface file, if any, for the module being compiled
+ findAndReadIface doc_str mod_name False {- Not hi-boot -} `thenRn` \ maybe_iface ->
+
+ -- CHECK WHETHER WE HAVE IT ALREADY
+ case maybe_iface of
+ Left err -> -- Old interface file not found, so we'd better bail out
+ traceRn (vcat [ptext SLIT("No old interface file for") <+> pprModuleName mod_name,
+ err]) `thenRn_`
+ returnRn (outOfDate, Nothing)
+
+ Right iface
+ | not opt_SourceUnchanged
+ -> -- Source code changed
+ traceRn (nest 4 (text "source file changed or recompilation check turned off")) `thenRn_`
+ returnRn (False, Just iface)
+
+ | otherwise
+ -> -- Source code unchanged and no errors yet... carry on
+ checkModUsage (pi_usages iface) `thenRn` \ up_to_date ->
+ returnRn (up_to_date, Just iface)
+ where
+ -- Only look in current directory, with suffix .hi
+ doc_str = sep [ptext SLIT("need usage info from"), pprModuleName mod_name]
\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
-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 ->
- 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 ]
- in
- qualifyImports mod
- True -- Want qualified names
+ 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
- (ExportEnv filtered_avails' fixities')
+ 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
+ = map improve_avail avails
where
- set_name_prov name = setNameProvenance name provenance
- provenance = Imported mod loc
+ improve_avail (Avail n) = Avail (improve n)
+ improve_avail (AvailTC n ns) = AvailTC (improve n) (map improve ns)
+
+ 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 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
- True -- Want unqualified names
- Nothing -- No "as M" part
- (ExportEnv avails fixities)
- where
- newLocalName rdr_name loc
- = newLocallyDefinedGlobalName mod (rdrNameOcc rdr_name) rec_exp_fn loc
+importsFromLocalDecls mod_name rec_exp_fn decls
+ = mapRn (getLocalDeclBinders mod rec_exp_fn) decls `thenRn` \ avails_s ->
- getLocalDeclBinders avails (ValD binds)
- = mapRn do_one (bagToList (collectTopBinders binds)) `thenRn` \ val_avails ->
- returnRn (val_avails ++ avails)
+ let
+ avails = concat avails_s
- getLocalDeclBinders avails decl
- = getDeclBinders newLocalName decl `thenRn` \ avail ->
- returnRn (avail : avails)
+ all_names :: [Name] -- All the defns; no dups eliminated
+ all_names = [name | avail <- avails, name <- availNames avail]
- do_one (rdr_name, loc)
- = newLocalName rdr_name loc `thenRn` \ name ->
- returnRn (Avail name [])
+ 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 avails `thenRn_`
+
+ -- Build the environment
+ qualifyImports mod_name
+ True -- Want unqualified names
+ Nothing -- no 'as M'
+ [] -- Hide nothing
+ avails
+
+ where
+ mod = mkThisModule mod_name
+
+getLocalDeclBinders :: Module -> (Name -> ExportFlag)
+ -> RdrNameHsDecl -> RnMG Avails
+getLocalDeclBinders mod rec_exp_fn (ValD binds)
+ = mapRn do_one (bagToList (collectTopBinders binds))
+ where
+ do_one (rdr_name, loc) = newLocalName mod rec_exp_fn rdr_name loc `thenRn` \ name ->
+ returnRn (Avail name)
+
+getLocalDeclBinders mod rec_exp_fn decl
+ = getDeclBinders (newLocalName mod rec_exp_fn) decl `thenRn` \ maybe_avail ->
+ case maybe_avail of
+ Nothing -> returnRn [] -- Instance decls and suchlike
+ Just avail -> returnRn [avail]
+
+newLocalName mod rec_exp_fn rdr_name loc
+ = check_unqual rdr_name loc `thenRn_`
+ newTopBinder mod (rdrNameOcc rdr_name) `thenRn` \ name ->
+ returnRn (setNameProvenance name (LocalDef loc (rec_exp_fn name)))
+ where
+ -- There should never be a qualified name in a binding position (except in instance decls)
+ -- The parser doesn't check this because the same parser parses instance decls
+ check_unqual rdr_name loc
+ | isUnqual rdr_name = returnRn ()
+ | otherwise = qualNameErr (text "the binding for" <+> quotes (ppr rdr_name))
+ (rdr_name,loc)
\end{code}
+
%************************************************************************
%* *
\subsection{Filtering imports}
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)
+ -- (We need to return both the above sets, because
+ -- the qualified version is never hidden; so we can't
+ -- implement hiding by reducing what's imported.)
+ NameSet) -- What was imported explicitly
+
+ -- Complains if import spec mentions things that the module doesn't export
+ -- Warns/informs if import spec contains duplicates.
filterImports mod Nothing imports
- = returnRn imports
+ = 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)
-
+ = flatMapRn get_item import_items `thenRn` \ avails_w_explicits ->
+ let
+ (item_avails, explicits_s) = unzip avails_w_explicits
+ explicits = foldl addListToNameSet emptyNameSet explicits_s
+ in
+ if want_hiding
+ then
+ -- All imported; item_avails to be hidden
+ returnRn (avails, item_avails, emptyNameSet)
+ else
+ -- Just item_avails imported; nothing to be hidden
+ returnRn (item_avails, [], explicits)
where
- import_fm :: FiniteMap OccName 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.
+
+ bale_out item = addErrRn (badImportItemErr mod item) `thenRn_`
+ returnRn []
+
+ get_item item@(IEModuleContents _) = bale_out item
+
+ get_item item@(IEThingAll _)
+ = case check_item item of
+ Nothing -> bale_out item
+ Just avail@(AvailTC _ [n]) -> -- This occurs when you import T(..), but
+ -- only export T abstractly. The single [n]
+ -- in the AvailTC is the type or class itself
+ addWarnRn (dodgyImportWarn mod item) `thenRn_`
+ returnRn [(avail, [availName avail])]
+ Just avail -> returnRn [(avail, [availName avail])]
+
+ get_item item@(IEThingAbs n)
+ | want_hiding -- hiding( C )
+ -- Here the 'C' can be a data constructor *or* a type/class
+ = case catMaybes [check_item item, check_item (IEThingAbs data_n)] of
+ [] -> bale_out item
+ avails -> returnRn [(a, []) | a <- avails]
+ -- The 'explicits' list is irrelevant when hiding
+ where
+ data_n = setRdrNameOcc n (setOccNameSpace (rdrNameOcc n) dataName)
+
+ get_item item
+ = case check_item item of
+ Nothing -> bale_out item
+ Just avail -> returnRn [(avail, availNames avail)]
+
+ check_item item
+ | not (maybeToBool maybe_in_import_avails) ||
+ not (maybeToBool maybe_filtered_avail)
+ = Nothing
+
+ | otherwise
+ = Just filtered_avail
+
+ where
+ wanted_occ = rdrNameOcc (ieName item)
+ maybe_in_import_avails = lookupFM import_fm wanted_occ
+
+ Just avail = maybe_in_import_avails
+ maybe_filtered_avail = filterAvail item avail
+ Just filtered_avail = maybe_filtered_avail
\end{code}
@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)
- where
- show_it (rdr, (fix,prov)) = ppSep [ppLbrack, ppr PprDebug rdr, ppr PprDebug fix, pprProvenance PprDebug prov, ppRbrack]
+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
+ -> RnMG (GlobalRdrEnv, ExportAvails)
+
+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.
+ -- 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
-\end{code}
+ env1 = addOneToGlobalRdrEnv env (mkRdrQual qual_mod occ) name
+ env2 = addOneToGlobalRdrEnv env1 (mkRdrUnqual occ) name
+ occ = nameOccName name
-unQualify adds an Unqual binding for every existing Qual binding.
+ del_avail env avail = foldl delOneFromGlobalRdrEnv env rdr_names
+ where
+ rdr_names = map (mkRdrUnqual . nameOccName) (availNames avail)
-\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}
-%* *
-%************************************************************************
+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
-\begin{code}
-fixityFromFixDecl :: RdrNameFixityDecl -> RnMG (OccName, Fixity, Provenance)
+ 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]
-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@.
+Processing the export list.
-\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
-
-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]
+ -- 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, 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
+ 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 addAvail 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!
+
+
+ = warnCheckRn (ok_item ie avail) (dodgyExportWarn ie) `thenRn_`
+ check_occs ie occs export_avail `thenRn` \ occs' ->
+ returnRn (mods, occs', addAvail 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
+
+ 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
+ = 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 rdr_name
- = 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}
%************************************************************************
%* *
%************************************************************************
\begin{code}
-ieOcc ie = rdrNameOcc (ieName ie)
-
-badImportItemErr mod ie sty
- = ppSep [ppStr "Module", pprModule sty mod, ppStr "does not export", ppr sty ie]
+badImportItemErr mod ie
+ = sep [ptext SLIT("Module"), quotes (pprModuleName mod),
+ ptext SLIT("does not export"), quotes (ppr ie)]
+
+dodgyImportWarn mod item = dodgyMsg (ptext SLIT("import")) item
+dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item
+
+dodgyMsg kind item@(IEThingAll tc)
+ = sep [ ptext SLIT("The") <+> kind <+> ptext SLIT("item") <+> quotes (ppr item),
+ ptext SLIT("suggests that") <+> quotes (ppr tc) <+> ptext SLIT("has constructor or class methods"),
+ ptext SLIT("but it has none; it is a type synonym or abstract type or class") ]
+
+modExportErr mod
+ = hsep [ ptext SLIT("Unknown module in export list: module"), quotes (pprModuleName 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 pp sorted_ns))]
+ where
+ sorted_ns = sortLt occ'ed_before (n:ns)
-modExportErr mod sty
- = ppCat [ ppStr "Unknown module in export list: module", ppPStr mod]
+ occ'ed_before a b = LT == compare (getSrcLoc a) (getSrcLoc b)
-exportItemErr export_item NotAvailable sty
- = ppSep [ ppStr "Export item not in scope:", ppr sty export_item ]
+ pp n = pprProvenance (getNameProvenance n)
-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]])
+dupExportWarn occ_name ie1 ie2
+ = hsep [quotes (ppr occ_name),
+ ptext SLIT("is exported by"), quotes (ppr ie1),
+ ptext SLIT("and"), quotes (ppr ie2)]
-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])
+dupModuleExport mod
+ = hsep [ptext SLIT("Duplicate"),
+ quotes (ptext SLIT("Module") <+> pprModuleName mod),
+ ptext SLIT("in export list")]
\end{code}
-
projects / ghc-hetmet.git / blobdiff