\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(..), ImportDecl(..), HsDecl(..),
+ IE(..), ieName,
+ FixityDecl(..),
collectTopBinders
)
-import HsImpExp ( ieName )
-import RdrHsSyn ( RdrNameHsDecl(..), RdrName(..), RdrNameIE(..), SYN_IE(RdrNameImportDecl),
- SYN_IE(RdrNameHsModule), SYN_IE(RdrNameFixityDecl),
+import RdrHsSyn ( RdrNameHsDecl(..), RdrName(..), RdrNameIE(..), RdrNameImportDecl,
+ RdrNameHsModule, RdrNameFixityDecl,
rdrNameOcc, ieOcc
)
import RnHsSyn ( RenamedHsModule(..), RenamedFixityDecl(..) )
-import RnIfaces ( getInterfaceExports, getDeclBinders, checkUpToDate, recordSlurp )
+import RnIfaces ( getInterfaceExports, getDeclBinders, recordSlurp, checkUpToDate )
+import BasicTypes ( IfaceFlavour(..) )
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 Outputable ( Outputable(..), PprStyle(..) )
-import Util ( panic, pprTrace, assertPanic )
+import Outputable
+import Util ( removeDups )
\end{code}
\begin{code}
getGlobalNames :: RdrNameHsModule
- -> RnMG (Maybe (ExportEnv, RnEnv, NameSet))
- -- Nothing <=> no need to recompile
+ -> RnMG (Maybe (ExportEnv, RnEnv, NameSet, Name -> PrintUnqualified))
-- The NameSet is the set of names that are
-- either locally defined,
-- or explicitly imported
+ -- Nothing => no need to recompile
getGlobalNames m@(HsModule this_mod _ exports imports _ _ mod_loc)
= fixRn (\ ~(rec_exp_fn, _) ->
mapAndUnzip3Rn importsFromImportDecl all_imports
`thenRn` \ (imp_rn_envs, imp_avails_s, explicit_imports_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 second, so that a local provenance
-- "wins", even if a module imports itself.
foldlRn plusRnEnv emptyRnEnv imp_rn_envs `thenRn` \ imp_rn_env ->
plusRnEnv imp_rn_env local_rn_env `thenRn` \ rn_env ->
+
+ -- 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 plusRnEnv stuff to do the early-exit.
+ checkEarlyExit this_mod `thenRn` \ up_to_date ->
+ if up_to_date then
+ returnRn (error "early exit", Nothing)
+ else
+
+
+ -- PROCESS EXPORT LISTS
let
export_avails :: ExportAvails
export_avails = foldr plusExportAvails local_mod_avails imp_avails_s
explicit_names = foldr add_on emptyNameSet (local_avails : explicit_imports_s)
add_on avails names = foldr (unionNameSets . mkNameSet . availNames) names avails
in
-
- -- PROCESS EXPORT LISTS
exportsFromAvail this_mod exports export_avails rn_env
`thenRn` \ (export_fn, export_env) ->
-- RECORD THAT LOCALLY DEFINED THINGS ARE AVAILABLE
mapRn (recordSlurp Nothing Compulsory) local_avails `thenRn_`
- returnRn (export_fn, Just (export_env, rn_env, explicit_names))
+ -- BUILD THE "IMPORT FN". It just tells whether a name is in
+ -- scope in an unqualified form.
+ let
+ print_unqual = mkImportFn imp_rn_env
+ in
+
+ returnRn (export_fn, Just (export_env, rn_env, explicit_names, print_unqual))
) `thenRn` \ (_, result) ->
returnRn result
where
| otherwise = [ImportDecl pRELUDE
False {- Not qualified -}
- False {- Not source imported -}
+ HiFile {- Not source imported -}
Nothing {- No "as" -}
Nothing {- No import list -}
mod_loc]
-- Found errors already, so exit now
returnRn True
else
+
traceRn (text "Considering whether compilation is required...") `thenRn_`
- (if not opt_SourceUnchanged then
+ if not opt_SourceUnchanged then
-- Source code changed and no errors yet... carry on
- traceRn (nest 4 (text "source file changed")) `thenRn_`
+ traceRn (nest 4 (text "source file changed or recompilation check turned off")) `thenRn_`
returnRn False
- else
+ else
+
-- Unchanged source, and no errors yet; see if usage info
-- up to date, and exit if so
- checkUpToDate mod
- ) `thenRn` \ up_to_date ->
- traceRn (text "Hence, compilation" <+>
- text (if up_to_date then "IS NOT" else "IS") <+>
- text "required") `thenRn_`
+ checkUpToDate mod `thenRn` \ up_to_date ->
+ putDocRn (text "Compilation" <+>
+ text (if up_to_date then "IS NOT" else "IS") <+>
+ text "required") `thenRn_`
returnRn up_to_date
\end{code}
-
\begin{code}
importsFromImportDecl :: RdrNameImportDecl
-> RnMG (RnEnv, ExportAvails, [AvailInfo])
getInterfaceExports mod as_source `thenRn` \ (avails, fixities) ->
filterImports mod import_spec avails `thenRn` \ (filtered_avails, hides, explicits) ->
let
- filtered_avails' = map set_avail_prov filtered_avails
- fixities' = [ (occ,(fixity,provenance)) | (occ,fixity) <- fixities ]
+ how_in_scope = FromImportDecl mod loc
in
qualifyImports mod
True -- Want qualified names
(not qual_only) -- Maybe want unqualified names
as_mod
- (ExportEnv filtered_avails' fixities')
hides
+ filtered_avails (\n -> how_in_scope)
+ [ (occ,(fixity,how_in_scope)) | (occ,fixity) <- fixities ]
`thenRn` \ (rn_env, mod_avails) ->
returnRn (rn_env, mod_avails, explicits)
- where
- set_avail_prov NotAvailable = NotAvailable
- set_avail_prov (Avail n) = Avail (set_name_prov n)
- set_avail_prov (AvailTC n ns) = AvailTC (set_name_prov n) (map set_name_prov ns)
- set_name_prov name = setNameProvenance name provenance
- provenance = Imported mod loc
\end{code}
False -- Don't want qualified names
True -- Want unqualified names
Nothing -- No "as M" part
- (ExportEnv avails fixities)
[] -- Hide nothing
+ avails (\n -> FromLocalDefn (getSrcLoc n))
+ fixities
`thenRn` \ (rn_env, mod_avails) ->
returnRn (rn_env, mod_avails, avails)
where
[AvailInfo]) -- 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, [], [])
-> Bool -- True <=> want qualified import
-> Bool -- True <=> want unqualified import
-> Maybe Module -- Optional "as M" part
- -> ExportEnv -- What's imported
-> [AvailInfo] -- What's to be hidden
+ -> Avails -> (Name -> HowInScope) -- Whats imported and how
+ -> [(OccName, (Fixity, HowInScope))] -- Ditto for fixities
-> RnMG (RnEnv, ExportAvails)
-qualifyImports this_mod qual_imp unqual_imp as_mod (ExportEnv avails fixities) hides
+qualifyImports this_mod qual_imp unqual_imp as_mod hides
+ avails name_to_his fixities
=
-- Make the name environment. Even though we're talking about a
-- single import module there might still be name clashes,
-- because it might be the module being compiled.
- foldlRn add_avail emptyNameEnv avails `thenRn` \ name_env1 ->
+ foldlRn add_avail emptyGlobalNameEnv avails `thenRn` \ name_env1 ->
let
-- Delete things that are hidden
name_env2 = foldl del_avail name_env1 hides
Nothing -> this_mod
Just another_name -> another_name
+ add_avail :: GlobalNameEnv -> AvailInfo -> RnMG GlobalNameEnv
add_avail env avail = foldlRn add_name env (availNames avail)
- add_name env name = add qual_imp env (Qual qual_mod occ) `thenRn` \ env1 ->
+
+ add_name env name = add qual_imp env (Qual qual_mod occ err_hif) `thenRn` \ env1 ->
add unqual_imp env1 (Unqual occ)
where
add False env rdr_name = returnRn env
- add True env rdr_name = addOneToNameEnv env rdr_name name
+ add True env rdr_name = addOneToGlobalNameEnv env rdr_name (name, name_to_his name)
occ = nameOccName name
- del_avail env avail = foldl delOneFromNameEnv env rdr_names
+ del_avail env avail = foldl delOneFromGlobalNameEnv env rdr_names
where
rdr_names = map (Unqual . nameOccName) (availNames avail)
- add_fixity name_env fix_env (occ_name, (fixity, provenance))
+ add_fixity name_env fix_env (occ_name, fixity)
= add qual $ add unqual $ fix_env
where
- qual = Qual qual_mod occ_name
+ qual = Qual qual_mod occ_name err_hif
unqual = Unqual occ_name
add rdr_name fix_env | maybeToBool (lookupFM name_env rdr_name)
- = addOneToFixityEnv fix_env rdr_name (fixity,provenance)
+ = addOneToFixityEnv fix_env rdr_name fixity
| otherwise
= fix_env
+
+err_hif = error "qualifyImports: hif" -- Not needed in key to mapping
\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]
+unQualify fm = addListToFM fm [(Unqual occ, elt) | (Qual _ occ _, elt) <- fmToList fm]
\end{code}
%************************************************************************
\begin{code}
-fixityFromFixDecl :: RdrNameFixityDecl -> RnMG (OccName, (Fixity, Provenance))
+fixityFromFixDecl :: RdrNameFixityDecl -> RnMG (OccName, (Fixity, HowInScope))
fixityFromFixDecl (FixityDecl rdr_name fixity loc)
- = returnRn (rdrNameOcc rdr_name, (fixity, LocalDef (panic "export-flag") loc))
+ = returnRn (rdrNameOcc rdr_name, (fixity, FromLocalDefn loc))
\end{code}
is: two exported things must have different @OccNames@.
\begin{code}
-type AvailEnv = FiniteMap OccName (RdrNameIE, AvailInfo)
+type AvailEnv = FiniteMap OccName (RdrNameIE, AvailInfo, Int{-no. of clashes-})
-- 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 (AvailTC _ []) = emptyFM
-unitAvailEnv ie avail = unitFM (nameOccName (availName avail)) (ie,avail)
+{-
+ Add new entry to environment. Checks for name clashes, i.e.,
+ plain duplicates or exported entity pairs that have different OccNames.
+ (c.f. 5.1.1 of Haskell 1.4 report.)
+-}
+addAvailEnv :: Bool -> RdrNameIE -> AvailEnv -> AvailInfo -> RnM s d AvailEnv
+addAvailEnv warn_dups ie env NotAvailable = returnRn env
+addAvailEnv warn_dups ie env (AvailTC _ []) = returnRn env
+addAvailEnv warn_dups ie env avail
+ | warn_dups = mapMaybeRn (addErrRn . availClashErr) () conflict `thenRn_`
+ returnRn (addToFM_C addAvail env key elt)
+ | otherwise = returnRn (addToFM_C addAvail env key elt)
+ where
+ key = nameOccName (availName avail)
+ elt = (ie,avail,reports_on)
+
+ reports_on
+ | maybeToBool dup = 1
+ | otherwise = 0
-plusAvailEnv a1 a2
- = mapRn (addErrRn.availClashErr) (conflictsFM bad_avail a1 a2) `thenRn_`
- returnRn (plusFM_C plus_avail a1 a2)
+ conflict = conflictFM bad_avail env key elt
+ dup
+ | warn_dups = conflictFM dup_avail env key elt
+ | otherwise = Nothing
-listToAvailEnv :: RdrNameIE -> [AvailInfo] -> RnM s d AvailEnv
-listToAvailEnv ie items
- = foldlRn plusAvailEnv emptyAvailEnv (map (unitAvailEnv ie) items)
+addListToAvailEnv :: AvailEnv -> RdrNameIE -> [AvailInfo] -> RnM s d AvailEnv
+addListToAvailEnv env ie items = foldlRn (addAvailEnv False ie) env items
-bad_avail (ie1,avail1) (ie2,avail2) = availName avail1 /= availName avail2 -- Same OccName, different Name
-plus_avail (ie1,a1) (ie2,a2) = (ie1, a1 `plusAvail` a2)
+bad_avail (ie1,avail1,r1) (ie2,avail2,r2)
+ = availName avail1 /= availName avail2 -- Same OccName, different Name
+dup_avail (ie1,avail1,r1) (ie2,avail2,r2)
+ = availName avail1 == availName avail2 -- Same OccName & avail.
+
+addAvail (ie1,a1,r1) (ie2,a2,r2) = (ie1, a1 `plusAvail` a2, r1 + r2)
\end{code}
Processing the export list.
-> RnEnv
-> RnMG (Name -> ExportFlag, ExportEnv)
-- Complains if two distinct exports have same OccName
+ -- Warns about identical exports.
-- Complains about exports items not in scope
exportsFromAvail this_mod Nothing export_avails rn_env
= exportsFromAvail this_mod (Just [IEModuleContents this_mod]) export_avails rn_env
exportsFromAvail this_mod (Just export_items)
(mod_avail_env, entity_avail_env)
- (RnEnv name_env fixity_env)
- = mapRn exports_from_item export_items `thenRn` \ avail_envs ->
- foldlRn plusAvailEnv emptyAvailEnv avail_envs `thenRn` \ export_avail_env ->
+ (RnEnv global_name_env fixity_env)
+ = checkForModuleExportDups export_items `thenRn` \ export_items' ->
+ foldlRn exports_from_item emptyAvailEnv export_items' `thenRn` \ export_avail_env ->
+ let
+ dup_entries = fmToList (filterFM (\ _ (_,_,clashes) -> clashes > 0) export_avail_env)
+ in
+ mapRn (addWarnRn . dupExportWarn) dup_entries `thenRn_`
let
- export_avails = map snd (eltsFM export_avail_env)
+ export_avails = map (\ (_,a,_) -> a) (eltsFM export_avail_env)
export_fixities = mk_exported_fixities (availsToNameSet export_avails)
export_fn = mk_export_fn export_avails
in
returnRn (export_fn, ExportEnv export_avails export_fixities)
where
- exports_from_item :: RdrNameIE -> RnMG AvailEnv
- exports_from_item ie@(IEModuleContents mod)
+ exports_from_item :: AvailEnv -> RdrNameIE -> RnMG AvailEnv
+ exports_from_item export_avail_env ie@(IEModuleContents mod)
= case lookupFM mod_avail_env mod of
- Nothing -> failWithRn emptyAvailEnv (modExportErr mod)
- Just avails -> listToAvailEnv ie avails
+ Nothing -> failWithRn export_avail_env (modExportErr mod)
+ Just avails -> addListToAvailEnv export_avail_env ie avails
- exports_from_item ie
+ exports_from_item export_avail_env ie
| not (maybeToBool maybe_in_scope)
- = failWithRn emptyAvailEnv (unknownNameErr (ieName ie))
+ = failWithRn export_avail_env (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
+ = pprTrace "exportsFromAvail: curious Nothing:" (ppr name)
+ returnRn export_avail_env
#endif
| not enough_avail
- = failWithRn emptyAvailEnv (exportItemErr ie export_avail)
+ = failWithRn export_avail_env (exportItemErr ie export_avail)
| otherwise -- Phew! It's OK!
- = returnRn (unitAvailEnv ie export_avail)
+ = addAvailEnv opt_WarnDuplicateExports ie export_avail_env export_avail
where
- maybe_in_scope = lookupNameEnv name_env (ieName ie)
- Just name = maybe_in_scope
+ maybe_in_scope = lookupFM global_name_env (ieName ie)
+ Just (name,_) = maybe_in_scope
maybe_avail = lookupUFM entity_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 :: NameSet -> [(OccName, Fixity)]
mk_exported_fixities exports
= fmToList (foldr (perhaps_add_fixity exports)
emptyFM
(fmToList fixity_env))
- perhaps_add_fixity :: NameSet -> (RdrName, (Fixity, Provenance))
- -> FiniteMap OccName (Fixity,Provenance)
- -> FiniteMap OccName (Fixity,Provenance)
- perhaps_add_fixity exports (rdr_name, (fixity, prov)) fix_env
+ perhaps_add_fixity :: NameSet -> (RdrName, (Fixity, HowInScope))
+ -> FiniteMap OccName Fixity
+ -> FiniteMap OccName Fixity
+ perhaps_add_fixity exports (rdr_name, (fixity, how_in_scope)) fix_env
= let
do_nothing = fix_env -- The default is to pass on the env unchanged
in
-- Step 1: check whether the rdr_name is in scope; if so find its Name
- case lookupFM name_env rdr_name of {
- Nothing -> do_nothing;
- Just fixity_name ->
+ case lookupFM global_name_env rdr_name of {
+ Nothing -> do_nothing;
+ Just (fixity_name,_) ->
-- Step 2: check whether the fixity thing is exported
if not (fixity_name `elemNameSet` exports) then
occ_name = rdrNameOcc rdr_name
in
case lookupFM fix_env occ_name of {
- Just (fixity1, prov1) -> -- Got it already
- ASSERT( fixity == fixity1 )
- do_nothing;
+ Just fixity1 -> -- Got it already
+ ASSERT( fixity == fixity1 )
+ do_nothing;
Nothing ->
-- Step 3: add it to the outgoing fix_env
- addToFM fix_env occ_name (fixity,prov)
+ addToFM fix_env occ_name fixity
}}
+{- warn and weed out duplicate module entries from export list. -}
+checkForModuleExportDups :: [RdrNameIE] -> RnMG [RdrNameIE]
+checkForModuleExportDups ls
+ | opt_WarnDuplicateExports = check_modules ls
+ | otherwise = returnRn ls
+ where
+ -- NOTE: reorders the export list by moving all module-contents
+ -- exports to the end (removing duplicates in the process.)
+ check_modules ls =
+ (case dups of
+ [] -> returnRn ()
+ ls -> mapRn (\ ds@(IEModuleContents x:_) ->
+ addWarnRn (dupModuleExport x (length ds))) ls `thenRn_`
+ returnRn ()) `thenRn_`
+ returnRn (ls_no_modules ++ no_module_dups)
+ where
+ (ls_no_modules,modules) = foldr split_mods ([],[]) ls
+
+ split_mods i@(IEModuleContents _) ~(no_ms,ms) = (no_ms,i:ms)
+ split_mods i ~(no_ms,ms) = (i:no_ms,ms)
+
+ (no_module_dups, dups) = removeDups cmp_mods modules
+
+ cmp_mods (IEModuleContents m1) (IEModuleContents m2) = m1 `compare` m2
+
mk_export_fn :: [AvailInfo] -> (Name -> ExportFlag)
mk_export_fn avails
= \name -> if name `elemNameSet` exported_names
where
exported_names :: NameSet
exported_names = availsToNameSet avails
-\end{code}
-
+\end{code}
%************************************************************************
%* *
%************************************************************************
\begin{code}
-badImportItemErr mod ie sty
- = sep [ptext SLIT("Module"), pprModule sty mod, ptext SLIT("does not export"), ppr sty ie]
+badImportItemErr mod ie
+ = sep [ptext SLIT("Module"), quotes (pprModule mod),
+ ptext SLIT("does not export"), quotes (ppr ie)]
-modExportErr mod sty
- = hsep [ ptext SLIT("Unknown module in export list: module"), ptext mod]
+modExportErr mod
+ = hsep [ ptext SLIT("Unknown module in export list: module"), quotes (pprModule mod)]
-exportItemErr export_item NotAvailable sty
- = sep [ ptext SLIT("Export item not in scope:"), ppr sty export_item ]
+exportItemErr export_item NotAvailable
+ = sep [ ptext SLIT("Export item not in scope:"), quotes (ppr export_item)]
-exportItemErr export_item avail sty
+exportItemErr export_item avail
= hang (ptext SLIT("Export item not fully in scope:"))
- 4 (vcat [hsep [ptext SLIT("Wanted: "), ppr sty export_item],
- hsep [ptext SLIT("Available:"), ppr sty (ieOcc export_item), pprAvail sty avail]])
-
-availClashErr (occ_name, ((ie1,avail1), (ie2,avail2))) sty
- = hsep [ptext SLIT("The export items"), ppr sty ie1, ptext SLIT("and"), ppr sty ie2,
- ptext SLIT("create conflicting exports for"), ppr sty occ_name]
+ 4 (vcat [hsep [ptext SLIT("Wanted: "), ppr export_item],
+ hsep [ptext SLIT("Available:"), ppr (ieOcc export_item), pprAvail avail]])
+
+availClashErr (occ_name, ((ie1,avail1,_), (ie2,avail2,_)))
+ = 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)]
+
+dupExportWarn (occ_name, (_,_,times))
+ = hsep [quotes (ppr occ_name),
+ ptext SLIT("mentioned"), speakNTimes (times+1),
+ ptext SLIT("in export list")]
+
+dupModuleExport mod times
+ = hsep [ptext SLIT("Module"), quotes (pprModule mod),
+ ptext SLIT("mentioned"), speakNTimes times,
+ ptext SLIT("in export list")]
\end{code}