%
-% (c) The GRASP Project, Glasgow University, 1992-1996
+% (c) The GRASP Project, Glasgow University, 1992-1998
%
\section[Rename]{Renaming and dependency analysis passes}
\begin{code}
-#include "HsVersions.h"
-
module Rename ( renameModule ) where
-#if __GLASGOW_HASKELL__ <= 201
-import PreludeGlaST ( thenPrimIO )
-#else
-import GlaExts
-import IO
-#endif
-
-IMP_Ubiq()
-IMPORT_1_3(List(partition))
+#include "HsVersions.h"
import HsSyn
-import RdrHsSyn ( RdrName(..), SYN_IE(RdrNameHsModule), SYN_IE(RdrNameImportDecl) )
-import RnHsSyn ( SYN_IE(RenamedHsModule), SYN_IE(RenamedHsDecl), extractHsTyNames )
+import RdrHsSyn ( RdrNameHsModule )
+import RnHsSyn ( RenamedHsModule, RenamedHsDecl, extractHsTyNames )
-import CmdLineOpts ( opt_HiMap, opt_WarnNameShadowing, opt_D_show_rn_trace,
+import CmdLineOpts ( opt_HiMap, opt_D_show_rn_trace,
opt_D_dump_rn, opt_D_show_rn_stats,
- opt_D_show_unused_imports, opt_PprUserLength
+ opt_WarnUnusedBinds, opt_WarnUnusedImports
)
import RnMonad
import RnNames ( getGlobalNames )
-import RnSource ( rnDecl )
+import RnSource ( rnIfaceDecl, rnSourceDecls )
import RnIfaces ( getImportedInstDecls, importDecl, getImportVersions, getSpecialInstModules,
getDeferredDataDecls,
mkSearchPath, getSlurpedNames, getRnStats
)
-import RnEnv ( availsToNameSet, addAvailToNameSet,
- addImplicitOccsRn, lookupImplicitOccRn )
-import Id ( GenId {- instance NamedThing -} )
-import Name ( Name, Provenance, ExportFlag(..), isLocallyDefined,
- NameSet(..), elemNameSet, mkNameSet, unionNameSets,
- nameSetToList, minusNameSet, NamedThing(..),
- nameModule, pprModule, pprOccName, nameOccName
+import RnEnv ( addImplicitOccsRn, availName, availNames, availsToNameSet,
+ warnUnusedTopNames
)
-import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon )
+import Module ( pprModule )
+import Name ( Name, isLocallyDefined,
+ NamedThing(..), ImportReason(..), Provenance(..),
+ nameModule, pprOccName, nameOccName,
+ getNameProvenance, occNameUserString,
+ )
+import RdrName ( RdrName )
+import NameSet
import TyCon ( TyCon )
-import PrelMods ( mAIN, gHC_MAIN )
-import ErrUtils ( SYN_IE(Error), SYN_IE(Warning), pprBagOfErrors,
+import PrelMods ( mAIN, pREL_MAIN )
+import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon )
+import PrelInfo ( ioTyCon_NAME, thinAirIdNames )
+import Type ( funTyCon )
+import ErrUtils ( pprBagOfErrors, pprBagOfWarnings,
doIfSet, dumpIfSet, ghcExit
)
-import FiniteMap ( emptyFM, eltsFM, fmToList, addToFM, FiniteMap )
-import Pretty
-import Outputable ( Outputable(..), PprStyle(..),
- pprErrorsStyle, pprDumpStyle, printErrs
- )
import Bag ( isEmptyBag )
-import Util ( cmpPString, equivClasses, panic, assertPanic, pprTrace )
-#if __GLASGOW_HASKELL__ >= 202
-import UniqSupply
-#endif
+import FiniteMap ( fmToList, delListFromFM )
+import UniqSupply ( UniqSupply )
+import Util ( equivClasses )
+import Maybes ( maybeToBool )
+import Outputable
\end{code}
\begin{code}
renameModule :: UniqSupply
-> RdrNameHsModule
- -> IO (Maybe (RenamedHsModule, -- Output, after renaming
- InterfaceDetails, -- Interface; for interface file generatino
- RnNameSupply, -- Final env; for renaming derivings
- [Module])) -- Imported modules; for profiling
-
-renameModule us this_mod@(HsModule mod_name vers exports imports fixities local_decls loc)
+ -> IO (Maybe
+ ( RenamedHsModule -- Output, after renaming
+ , InterfaceDetails -- Interface; for interface file generatino
+ , RnNameSupply -- Final env; for renaming derivings
+ , [Module] -- Imported modules; for profiling
+ ))
+
+renameModule us this_mod@(HsModule mod_name vers exports imports local_decls loc)
= -- Initialise the renamer monad
initRn mod_name us (mkSearchPath opt_HiMap) loc
(rename this_mod) >>=
-- Check for warnings
doIfSet (not (isEmptyBag rn_warns_bag))
- (print_errs rn_warns_bag) >>
+ (printErrs (pprBagOfWarnings rn_warns_bag)) >>
-- Check for errors; exit if so
doIfSet (not (isEmptyBag rn_errs_bag))
- (print_errs rn_errs_bag >>
+ (printErrs (pprBagOfErrors rn_errs_bag) >>
ghcExit 1
) >>
Nothing -> return ()
Just results@(rn_mod, _, _, _)
-> dumpIfSet opt_D_dump_rn "Renamer:"
- (ppr pprDumpStyle rn_mod)
+ (ppr rn_mod)
) >>
-- Return results
return maybe_rn_stuff
-
-
-print_errs errs = printErrs (pprBagOfErrors pprErrorsStyle errs)
\end{code}
\begin{code}
-rename this_mod@(HsModule mod_name vers exports imports fixities local_decls loc)
- = -- FIND THE GLOBAL NAME ENVIRONMENT
- getGlobalNames this_mod `thenRn` \ global_name_info ->
-
- case global_name_info of {
- Nothing -> -- Everything is up to date; no need to recompile further
- rnStats [] `thenRn_`
- returnRn Nothing ;
-
- -- Otherwise, just carry on
- Just (export_env, rn_env, explicit_names) ->
+rename this_mod@(HsModule mod_name vers exports imports local_decls loc)
+ = -- FIND THE GLOBAL NAME ENVIRONMENT
+ getGlobalNames this_mod `thenRn` \ maybe_stuff ->
+
+ -- CHECK FOR EARLY EXIT
+ if not (maybeToBool maybe_stuff) then
+ -- Everything is up to date; no need to recompile further
+ rnStats [] `thenRn_`
+ returnRn Nothing
+ else
+ let
+ Just (export_env, rn_env, global_avail_env) = maybe_stuff
+ in
-- RENAME THE SOURCE
- initRnMS rn_env mod_name SourceMode (
+ initRnMS rn_env SourceMode (
addImplicits mod_name `thenRn_`
- mapRn rnDecl local_decls
- ) `thenRn` \ rn_local_decls ->
+ rnSourceDecls local_decls
+ ) `thenRn` \ (rn_local_decls, fvs) ->
-- SLURP IN ALL THE NEEDED DECLARATIONS
- slurpDecls rn_local_decls `thenRn` \ rn_all_decls ->
+ slurpDecls rn_local_decls `thenRn` \ rn_all_decls ->
+ -- EXIT IF ERRORS FOUND
+ checkErrsRn `thenRn` \ no_errs_so_far ->
+ if not no_errs_so_far then
+ -- Found errors already, so exit now
+ rnStats [] `thenRn_`
+ returnRn Nothing
+ else
-- GENERATE THE VERSION/USAGE INFO
getImportVersions mod_name exports `thenRn` \ import_versions ->
getNameSupplyRn `thenRn` \ name_supply ->
-- REPORT UNUSED NAMES
- reportUnusedNames explicit_names `thenRn_`
+ reportUnusedNames rn_env global_avail_env
+ export_env
+ fvs `thenRn_`
-- GENERATE THE SPECIAL-INSTANCE MODULE LIST
-- The "special instance" modules are those modules that contain instance
-- RETURN THE RENAMED MODULE
let
- import_mods = [mod | ImportDecl mod _ _ _ _ _ <- imports]
+ import_mods = [mod | ImportDecl mod _ _ _ _ <- imports]
renamed_module = HsModule mod_name vers
- trashed_exports trashed_imports trashed_fixities
+ trashed_exports trashed_imports
rn_all_decls
loc
in
(import_versions, export_env, special_inst_mods),
name_supply,
import_mods))
- }
where
trashed_exports = {-trace "rnSource:trashed_exports"-} Nothing
trashed_imports = {-trace "rnSource:trashed_imports"-} []
- trashed_fixities = []
\end{code}
@addImplicits@ forces the renamer to slurp in some things which aren't
\begin{code}
addImplicits mod_name
- = addImplicitOccsRn default_tys
+ = addImplicitOccsRn (implicit_main ++ default_tys ++ thinAirIdNames)
where
-- Add occurrences for Int, Double, and (), because they
-- are the types to which ambigious type variables may be defaulted by
- -- the type checker; so they won't every appear explicitly.
+ -- the type checker; so they won't always appear explicitly.
-- [The () one is a GHC extension for defaulting CCall results.]
- default_tys = [getName intTyCon, getName doubleTyCon, getName unitTyCon ]
+ -- ALSO: funTyCon, since it occurs implicitly everywhere!
+ -- (we don't want to be bothered with addImplicitOcc at every
+ -- function application)
+ default_tys = [getName intTyCon, getName doubleTyCon,
+ getName unitTyCon, getName funTyCon]
+
+ -- Add occurrences for IO or PrimIO
+ implicit_main | mod_name == mAIN
+ || mod_name == pREL_MAIN = [ioTyCon_NAME]
+ | otherwise = []
\end{code}
slurp_compulsories decls `thenRn` \ decls1 ->
-- Next get the optional ones
- closeDecls Optional decls1 `thenRn` \ decls2 ->
+ closeDecls optional_mode decls1 `thenRn` \ decls2 ->
-- Finally get those deferred data type declarations
- getDeferredDataDecls `thenRn` \ data_decls ->
- mapRn rn_data_decl data_decls `thenRn` \ rn_data_decls ->
+ getDeferredDataDecls `thenRn` \ data_decls ->
+ mapRn (rn_data_decl compulsory_mode) data_decls `thenRn` \ rn_data_decls ->
-- Done
returnRn (rn_data_decls ++ decls2)
where
+ compulsory_mode = InterfaceMode Compulsory
+ optional_mode = InterfaceMode Optional
+
-- The "slurp_compulsories" function is a loop that alternates
-- between slurping compulsory decls and slurping the instance
-- decls thus made relavant.
-- whose decl we must slurp, which might let in some new instance decls,
-- and so on. Example: instance Foo a => Baz [a] where ...
slurp_compulsories decls
- = closeDecls Compulsory decls `thenRn` \ decls1 ->
+ = closeDecls compulsory_mode decls `thenRn` \ decls1 ->
-- Instance decls still pending?
getImportedInstDecls `thenRn` \ inst_decls ->
else
-- Yes, there are some, so rename them and loop
traceRn (sep [ptext SLIT("Slurped"), int (length inst_decls), ptext SLIT("instance decls")])
- `thenRn_`
- mapRn rn_inst_decl inst_decls `thenRn` \ new_inst_decls ->
+ `thenRn_`
+ mapRn (rn_inst_decl compulsory_mode) inst_decls `thenRn` \ new_inst_decls ->
slurp_compulsories (new_inst_decls ++ decls1)
\end{code}
\begin{code}
-closeDecls :: Necessity
+closeDecls :: RnMode
-> [RenamedHsDecl] -- Declarations got so far
-> RnMG [RenamedHsDecl] -- input + extra decls slurped
-- The monad includes a list of possibly-unresolved Names
-- This list is empty when closeDecls returns
-closeDecls necessity decls
- = popOccurrenceName necessity `thenRn` \ maybe_unresolved ->
+closeDecls mode decls
+ = popOccurrenceName mode `thenRn` \ maybe_unresolved ->
case maybe_unresolved of
-- No more unresolved names
Nothing -> returnRn decls
-- An unresolved name
- Just name
+ Just name_w_loc
-> -- Slurp its declaration, if any
--- traceRn (sep [ptext SLIT("Considering"), ppr PprDebug name]) `thenRn_`
- importDecl name necessity `thenRn` \ maybe_decl ->
+-- traceRn (sep [ptext SLIT("Considering"), ppr name_w_loc]) `thenRn_`
+ importDecl name_w_loc mode `thenRn` \ maybe_decl ->
case maybe_decl of
-- No declaration... (wired in thing or optional)
- Nothing -> closeDecls necessity decls
+ Nothing -> closeDecls mode decls
-- Found a declaration... rename it
- Just decl -> rn_iface_decl mod_name necessity decl `thenRn` \ new_decl ->
- closeDecls necessity (new_decl : decls)
+ Just decl -> rn_iface_decl mod_name mode decl `thenRn` \ new_decl ->
+ closeDecls mode (new_decl : decls)
where
- mod_name = nameModule name
-
+ mod_name = nameModule (fst name_w_loc)
-rn_iface_decl mod_name necessity decl -- Notice that the rnEnv starts empty
- = initRnMS emptyRnEnv mod_name (InterfaceMode necessity) (rnDecl decl)
+rn_iface_decl mod_name mode decl
+ = setModuleRn mod_name $
+ initRnMS emptyRnEnv mode (rnIfaceDecl decl)
-rn_inst_decl (mod_name,decl) = rn_iface_decl mod_name Compulsory (InstD decl)
-
-rn_data_decl (tycon_name,ty_decl) = rn_iface_decl mod_name Compulsory (TyD ty_decl)
- where
- mod_name = nameModule tycon_name
+rn_inst_decl mode (mod_name,decl) = rn_iface_decl mod_name mode (InstD decl)
+rn_data_decl mode (mod_name,ty_decl) = rn_iface_decl mod_name mode (TyClD ty_decl)
\end{code}
\begin{code}
-reportUnusedNames explicit_avail_names
- | not opt_D_show_unused_imports
+reportUnusedNames (RnEnv gbl_env _) avail_env (ExportEnv export_avails _) mentioned_names
+ | not (opt_WarnUnusedBinds || opt_WarnUnusedImports)
= returnRn ()
| otherwise
- = getSlurpedNames `thenRn` \ slurped_names ->
- let
- unused = explicit_avail_names `minusNameSet` slurped_names
- (local_unused, imported_unused) = partition isLocallyDefined (nameSetToList unused)
- imports_by_module = equivClasses cmp imported_unused
- name1 `cmp` name2 = nameModule name1 `_CMP_STRING_` nameModule name2
-
- pp_imp sty = sep [text "For information: the following unqualified imports are unused:",
- nest 4 (vcat (map (pp_group sty) imports_by_module))]
- pp_group sty (n:ns) = sep [hcat [text "Module ", pprModule (PprForUser opt_PprUserLength) (nameModule n), char ':'],
- nest 4 (sep (map (pprOccName sty . nameOccName) (n:ns)))]
-
- pp_local sty = sep [text "For information: the following local top-level definitions are unused:",
- nest 4 (sep (map (pprOccName sty . nameOccName) local_unused))]
+ = let
+ used_names = mentioned_names `unionNameSets` availsToNameSet export_avails
+
+ -- Now, a use of C implies a use of T,
+ -- if C was brought into scope by T(..) or T(C)
+ really_used_names = used_names `unionNameSets`
+ mkNameSet [ availName avail
+ | sub_name <- nameSetToList used_names,
+ let avail = case lookupNameEnv avail_env sub_name of
+ Just avail -> avail
+ Nothing -> pprTrace "r.u.n" (ppr sub_name) $
+ Avail sub_name
+ ]
+
+ defined_names = mkNameSet (concat (rdrEnvElts gbl_env))
+ defined_but_not_used = nameSetToList (defined_names `minusNameSet` really_used_names)
+
+ -- Filter out the ones only defined implicitly
+ bad_guys = filter reportableUnusedName defined_but_not_used
in
- (if null imported_unused
- then returnRn ()
- else addWarnRn pp_imp) `thenRn_`
+ warnUnusedTopNames bad_guys `thenRn_`
+ returnRn ()
- (if null local_unused
- then returnRn ()
- else addWarnRn pp_local)
+reportableUnusedName :: Name -> Bool
+reportableUnusedName name
+ = explicitlyImported (getNameProvenance name) &&
+ not (startsWithUnderscore (occNameUserString (nameOccName name)))
+ where
+ explicitlyImported (LocalDef _ _) = True -- Report unused defns of local vars
+ explicitlyImported (NonLocalDef (UserImport _ _ expl) _) = expl -- Report unused explicit imports
+ explicitlyImported other = False -- Don't report others
+
+ -- Haskell 98 encourages compilers to suppress warnings about
+ -- unused names in a pattern if they start with "_".
+ startsWithUnderscore ('_' : _) = True -- Suppress warnings for names starting
+ startsWithUnderscore other = False -- with an underscore
rnStats :: [RenamedHsDecl] -> RnMG ()
rnStats all_decls
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