%
-% (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, extractHsCtxtTyNames
+ )
-import CmdLineOpts ( opt_HiMap, opt_WarnNameShadowing, opt_D_show_rn_trace,
- opt_D_dump_rn, opt_D_show_passes
+import CmdLineOpts ( opt_HiMap, opt_D_dump_rn_trace,
+ opt_D_dump_rn, opt_D_dump_rn_stats,
+ opt_WarnUnusedBinds, opt_WarnUnusedImports
)
import RnMonad
import RnNames ( getGlobalNames )
-import RnSource ( rnDecl )
-import RnIfaces ( getImportedInstDecls, importDecl, getImportVersions, getSpecialInstModules,
- getDeferredDataDecls,
- mkSearchPath, getSlurpedNames, getRnStats
+import RnSource ( rnSourceDecls, rnDecl )
+import RnIfaces ( getImportedInstDecls, importDecl, getImportVersions,
+ getImportedRules, loadHomeInterface, getSlurped, removeContext
+ )
+import RnEnv ( availName, availNames, availsToNameSet,
+ warnUnusedImports, warnUnusedLocalBinds, mapFvRn, lookupImplicitOccRn,
+ FreeVars, plusFVs, plusFV, unitFV, emptyFVs, isEmptyFVs
)
-import RnEnv ( availsToNameSet, addAvailToNameSet,
- addImplicitOccsRn, lookupImplicitOccRn )
-import Id ( GenId {- instance NamedThing -} )
-import Name ( Name, Provenance, ExportFlag(..), isLocallyDefined,
- NameSet(..), elemNameSet, mkNameSet, unionNameSets,
- nameSetToList, minusNameSet, NamedThing(..),
- modAndOcc, pprModule, pprOccName, nameOccName
+import Module ( Module, ModuleName, pprModule, mkSearchPath, mkThisModule )
+import Name ( Name, isLocallyDefined,
+ NamedThing(..), ImportReason(..), Provenance(..),
+ pprOccName, nameOccName, nameUnique,
+ getNameProvenance, isUserImportedExplicitlyName,
+ maybeWiredInTyConName, maybeWiredInIdName, isWiredInName
)
-import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon )
-import PrelInfo ( ioTyCon_NAME, primIoTyCon_NAME )
-import TyCon ( TyCon )
-import PrelMods ( mAIN, gHC_MAIN )
-import ErrUtils ( SYN_IE(Error), SYN_IE(Warning) )
-import FiniteMap ( emptyFM, eltsFM, fmToList, addToFM, FiniteMap )
-import Pretty
-import PprStyle ( PprStyle(..) )
-import Util ( cmpPString, equivClasses, panic, assertPanic, pprTrace )
-#if __GLASGOW_HASKELL__ >= 202
-import UniqSupply
-#endif
+import Id ( idType )
+import DataCon ( dataConTyCon, dataConType )
+import TyCon ( TyCon, tyConDataCons, isSynTyCon, getSynTyConDefn )
+import RdrName ( RdrName )
+import NameSet
+import PrelMods ( mAIN_Name, pREL_MAIN_Name )
+import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon, boolTyCon )
+import PrelInfo ( ioTyCon_NAME, thinAirIdNames, fractionalClassKeys, derivingOccurrences )
+import Type ( namesOfType, funTyCon )
+import ErrUtils ( printErrorsAndWarnings, dumpIfSet, ghcExit )
+import BasicTypes ( NewOrData(..) )
+import Bag ( isEmptyBag, bagToList )
+import FiniteMap ( fmToList, delListFromFM, addToFM, sizeFM, eltsFM )
+import UniqSupply ( UniqSupply )
+import UniqFM ( lookupUFM )
+import Util ( equivClasses )
+import Maybes ( maybeToBool )
+import SrcLoc ( mkBuiltinSrcLoc )
+import Outputable
\end{code}
\begin{code}
renameModule :: UniqSupply
-> RdrNameHsModule
- -> IO (Maybe -- Nothing <=> everything up to date;
- -- no ned to recompile any further
- (RenamedHsModule, -- Output, after renaming
- InterfaceDetails, -- Interface; for interface file generatino
- RnNameSupply, -- Final env; for renaming derivings
- [Module]), -- Imported modules; for profiling
- Bag Error,
- Bag Warning
- )
-\end{code}
+ -> IO (Maybe
+ ( Module
+ , RenamedHsModule -- Output, after renaming
+ , InterfaceDetails -- Interface; for interface file generation
+ , RnNameSupply -- Final env; for renaming derivings
+ , [ModuleName] -- 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) >>=
+ \ ((maybe_rn_stuff, dump_action), rn_errs_bag, rn_warns_bag) ->
+
+ -- Check for warnings
+ printErrorsAndWarnings rn_errs_bag rn_warns_bag >>
+
+ -- Dump any debugging output
+ dump_action >>
+
+ -- Return results
+ if not (isEmptyBag rn_errs_bag) then
+ ghcExit 1 >> return Nothing
+ else
+ return maybe_rn_stuff
+\end{code}
\begin{code}
-renameModule us this_mod@(HsModule mod_name vers exports imports fixities local_decls loc)
- = -- INITIALISE THE RENAMER MONAD
- initRn mod_name us (mkSearchPath opt_HiMap) loc $
+rename this_mod@(HsModule mod_name vers _ imports local_decls mod_deprec 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
+ rnDump [] [] `thenRn` \ dump_action ->
+ returnRn (Nothing, dump_action)
+ else
+ let
+ Just (export_env, gbl_env, fixity_env, global_avail_env) = maybe_stuff
+ in
- -- FIND THE GLOBAL NAME ENVIRONMENT
- getGlobalNames this_mod `thenRn` \ global_name_info ->
+ -- RENAME THE SOURCE
+ initRnMS gbl_env fixity_env SourceMode (
+ rnSourceDecls local_decls
+ ) `thenRn` \ (rn_local_decls, source_fvs) ->
- case global_name_info of {
- Nothing -> -- Everything is up to date; no need to recompile further
- rnStats [] `thenRn_`
- returnRn Nothing ;
+ -- SLURP IN ALL THE NEEDED DECLARATIONS
+ implicitFVs mod_name rn_local_decls `thenRn` \ implicit_fvs ->
+ let
+ real_source_fvs = implicit_fvs `plusFV` source_fvs
+ -- It's important to do the "plus" this way round, so that
+ -- when compiling the prelude, locally-defined (), Bool, etc
+ -- override the implicit ones.
+ in
+ slurpImpDecls real_source_fvs `thenRn` \ rn_imp_decls ->
+ let
+ rn_all_decls = rn_local_decls ++ rn_imp_decls
- -- Otherwise, just carry on
- Just (export_env, rn_env, explicit_names) ->
+ -- COLLECT ALL DEPRECATIONS
+ deprec_sigs = [ ds | ValD bnds <- rn_local_decls, ds <- collectDeprecs bnds ]
- -- RENAME THE SOURCE
- initRnMS rn_env mod_name SourceMode (
- addImplicits mod_name `thenRn_`
- mapRn rnDecl local_decls
- ) `thenRn` \ rn_local_decls ->
+ (rn_mod_deprec, deprecs) = case mod_deprec of
+ Nothing -> (Nothing, deprec_sigs)
+ Just (DeprecMod t) -> let dm = DeprecMod t in (Just dm, dm:deprec_sigs)
- -- SLURP IN ALL THE NEEDED DECLARATIONS
- closeDecls rn_local_decls `thenRn` \ rn_all_decls ->
+ collectDeprecs EmptyBinds = []
+ collectDeprecs (ThenBinds x y) = collectDeprecs x ++ collectDeprecs y
+ collectDeprecs (MonoBind _ sigs _) = [ d | DeprecSig d _ <- sigs ]
+ in
+ -- EXIT IF ERRORS FOUND
+ checkErrsRn `thenRn` \ no_errs_so_far ->
+ if not no_errs_so_far then
+ -- Found errors already, so exit now
+ rnDump rn_imp_decls rn_all_decls `thenRn` \ dump_action ->
+ returnRn (Nothing, dump_action)
+ else
-- GENERATE THE VERSION/USAGE INFO
- getImportVersions mod_name exports `thenRn` \ import_versions ->
- getNameSupplyRn `thenRn` \ name_supply ->
+ getImportVersions mod_name export_env `thenRn` \ my_usages ->
+ getNameSupplyRn `thenRn` \ name_supply ->
-- REPORT UNUSED NAMES
- reportUnusedNames explicit_names `thenRn_`
+ reportUnusedNames gbl_env global_avail_env
+ export_env
+ source_fvs `thenRn_`
- -- GENERATE THE SPECIAL-INSTANCE MODULE LIST
- -- The "special instance" modules are those modules that contain instance
- -- declarations that contain no type constructor or class that was declared
- -- in that module.
- getSpecialInstModules `thenRn` \ imported_special_inst_mods ->
- let
- special_inst_decls = [d | InstD d@(InstDecl inst_ty _ _ _ _) <- rn_local_decls,
- all (not.isLocallyDefined) (nameSetToList (extractHsTyNames inst_ty))
- ]
- special_inst_mods | null special_inst_decls = imported_special_inst_mods
- | otherwise = mod_name : imported_special_inst_mods
- in
-
-
-- RETURN THE RENAMED MODULE
let
- import_mods = [mod | ImportDecl mod _ _ _ _ <- imports]
-
+ has_orphans = any isOrphanDecl rn_local_decls
+ direct_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
+ rn_mod_deprec
loc
in
- rnStats rn_all_decls `thenRn_`
- returnRn (Just (renamed_module,
- (import_versions, export_env, special_inst_mods),
- name_supply,
- import_mods))
- }
+ rnDump rn_imp_decls rn_all_decls `thenRn` \ dump_action ->
+ returnRn (Just (mkThisModule mod_name,
+ renamed_module,
+ (InterfaceDetails has_orphans my_usages export_env deprecs),
+ name_supply,
+ direct_import_mods), dump_action)
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
+@implicitFVs@ forces the renamer to slurp in some things which aren't
mentioned explicitly, but which might be needed by the type checker.
\begin{code}
-addImplicits mod_name
- = addImplicitOccsRn (implicit_main ++ default_tys)
+implicitFVs mod_name decls
+ = mapRn lookupImplicitOccRn implicit_occs `thenRn` \ implicit_names ->
+ returnRn (implicit_main `plusFV`
+ mkNameSet (map getName default_tycons) `plusFV`
+ mkNameSet thinAirIdNames `plusFV`
+ mkNameSet implicit_names)
where
- -- Add occurrences for Int, Double, and (), because they
+ -- Add occurrences for Int, 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 making funTyCon a
+ -- free var at every function application!)
+ -- Double is dealt with separately in getGates
+ default_tycons = [unitTyCon, funTyCon, boolTyCon, intTyCon]
-- Add occurrences for IO or PrimIO
- implicit_main | mod_name == mAIN = [ioTyCon_NAME]
- | mod_name == gHC_MAIN = [primIoTyCon_NAME]
- | otherwise = []
+ implicit_main | mod_name == mAIN_Name
+ || mod_name == pREL_MAIN_Name = unitFV ioTyCon_NAME
+ | otherwise = emptyFVs
+
+ -- Now add extra "occurrences" for things that
+ -- the deriving mechanism, or defaulting, will later need in order to
+ -- generate code
+ implicit_occs = foldr ((++) . get) [] decls
+
+ get (TyClD (TyData _ _ _ _ _ (Just deriv_classes) _ _))
+ = concat (map get_deriv deriv_classes)
+ get other = []
+
+ get_deriv cls = case lookupUFM derivingOccurrences cls of
+ Nothing -> []
+ Just occs -> occs
+\end{code}
+
+\begin{code}
+isOrphanDecl (InstD (InstDecl inst_ty _ _ _ _))
+ = not (foldNameSet ((||) . isLocallyDefined) False (extractHsTyNames (removeContext inst_ty)))
+ -- The 'removeContext' is because of
+ -- instance Foo a => Baz T where ...
+ -- The decl is an orphan if Baz and T are both not locally defined,
+ -- even if Foo *is* locally defined
+
+isOrphanDecl (RuleD (RuleDecl _ _ _ lhs _ _))
+ = check lhs
+ where
+ -- At the moment we just check for common LHS forms
+ -- Expand as necessary. Getting it wrong just means
+ -- more orphans than necessary
+ check (HsVar v) = not (isLocallyDefined v)
+ check (HsApp f a) = check f && check a
+ check (HsLit _) = False
+ check (OpApp l o _ r) = check l && check o && check r
+ check (NegApp e _) = check e
+ check (HsPar e) = check e
+ check (SectionL e o) = check e && check o
+ check (SectionR o e) = check e && check o
+
+ check other = True -- Safe fall through
+
+isOrphanDecl other = False
+\end{code}
+
+
+\begin{code}
+dupDefaultDeclErrRn (DefaultDecl _ locn1 : dup_things)
+ = pushSrcLocRn locn1 $
+ addErrRn msg
+ where
+ msg = hang (ptext SLIT("Multiple default declarations"))
+ 4 (vcat (map pp dup_things))
+ pp (DefaultDecl _ locn) = ptext SLIT("here was another default declaration") <+> ppr locn
+\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Slurping declarations}
+%* *
+%*********************************************************
+
+\begin{code}
+-------------------------------------------------------
+slurpImpDecls source_fvs
+ = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_`
+
+ -- The current slurped-set records all local things
+ getSlurped `thenRn` \ source_binders ->
+ slurpSourceRefs source_binders source_fvs `thenRn` \ (decls, needed) ->
+
+ -- And finally get everything else
+ closeDecls decls needed
+
+-------------------------------------------------------
+slurpSourceRefs :: NameSet -- Variables defined in source
+ -> FreeVars -- Variables referenced in source
+ -> RnMG ([RenamedHsDecl],
+ FreeVars) -- Un-satisfied needs
+-- The declaration (and hence home module) of each gate has
+-- already been loaded
+
+slurpSourceRefs source_binders source_fvs
+ = go_outer [] -- Accumulating decls
+ emptyFVs -- Unsatisfied needs
+ emptyFVs -- Accumulating gates
+ (nameSetToList source_fvs) -- Things whose defn hasn't been loaded yet
+ where
+ -- The outer loop repeatedly slurps the decls for the current gates
+ -- and the instance decls
+
+ -- The outer loop is needed because consider
+ -- instance Foo a => Baz (Maybe a) where ...
+ -- It may be that @Baz@ and @Maybe@ are used in the source module,
+ -- but not @Foo@; so we need to chase @Foo@ too.
+ --
+ -- We also need to follow superclass refs. In particular, 'chasing @Foo@' must
+ -- include actually getting in Foo's class decl
+ -- class Wib a => Foo a where ..
+ -- so that its superclasses are discovered. The point is that Wib is a gate too.
+ -- We do this for tycons too, so that we look through type synonyms.
+
+ go_outer decls fvs all_gates []
+ = returnRn (decls, fvs)
+
+ go_outer decls fvs all_gates refs -- refs are not necessarily slurped yet
+ = traceRn (text "go_outer" <+> ppr refs) `thenRn_`
+ go_inner decls fvs emptyFVs refs `thenRn` \ (decls1, fvs1, gates1) ->
+ getImportedInstDecls (all_gates `plusFV` gates1) `thenRn` \ inst_decls ->
+ rnInstDecls decls1 fvs1 gates1 inst_decls `thenRn` \ (decls2, fvs2, gates2) ->
+ go_outer decls2 fvs2 (all_gates `plusFV` gates2)
+ (nameSetToList (gates2 `minusNameSet` all_gates))
+ -- Knock out the all_gates because even if we don't slurp any new
+ -- decls we can get some apparently-new gates from wired-in names
+
+ go_inner decls fvs gates []
+ = returnRn (decls, fvs, gates)
+
+ go_inner decls fvs gates (wanted_name:refs)
+ | isWiredInName wanted_name
+ = load_home wanted_name `thenRn_`
+ go_inner decls fvs (gates `plusFV` getWiredInGates wanted_name) refs
+
+ | otherwise
+ = importDecl wanted_name `thenRn` \ maybe_decl ->
+ case maybe_decl of
+ Nothing -> go_inner decls fvs gates refs -- No declaration... (already slurped, or local)
+ Just decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) ->
+ go_inner (new_decl : decls)
+ (fvs1 `plusFV` fvs)
+ (gates `plusFV` getGates source_fvs new_decl)
+ refs
+
+ -- When we find a wired-in name we must load its
+ -- home module so that we find any instance decls therein
+ load_home name
+ | name `elemNameSet` source_binders = returnRn ()
+ -- When compiling the prelude, a wired-in thing may
+ -- be defined in this module, in which case we don't
+ -- want to load its home module!
+ -- Using 'isLocallyDefined' doesn't work because some of
+ -- the free variables returned are simply 'listTyCon_Name',
+ -- with a system provenance. We could look them up every time
+ -- but that seems a waste.
+ | otherwise = loadHomeInterface doc name `thenRn_`
+ returnRn ()
+ where
+ doc = ptext SLIT("need home module for wired in thing") <+> ppr name
+
+rnInstDecls decls fvs gates []
+ = returnRn (decls, fvs, gates)
+rnInstDecls decls fvs gates (d:ds)
+ = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) ->
+ rnInstDecls (new_decl:decls)
+ (fvs1 `plusFV` fvs)
+ (gates `plusFV` getInstDeclGates new_decl)
+ ds
\end{code}
\begin{code}
-closeDecls :: [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 decls
- = popOccurrenceName `thenRn` \ maybe_unresolved ->
- case maybe_unresolved of
-
- -- No more unresolved names
- Nothing -> -- Instance decls still pending?
- getImportedInstDecls `thenRn` \ inst_decls ->
- traceRn (sep [ptext SLIT("Slurped"), int (length inst_decls), ptext SLIT("instance decls")])
- `thenRn_`
- if not (null inst_decls) then
- mapRn rn_inst_decl inst_decls `thenRn` \ new_inst_decls ->
-
- -- We *must* loop again here. Why? Two reasons:
- -- (a) an instance decl will give rise to an unresolved dfun, whose
- -- decl we must slurp to get its version number; that's the version
- -- number for the whole instance decl. (And its unfolding might mention new
- -- unresolved names.)
- -- (b) an instance decl might give rise to a new unresolved class,
- -- whose decl we must slurp, which might let in some new instance decls,
- -- and so on. Example: instance Foo a => Baz [a] where ...
-
- closeDecls (new_inst_decls ++ decls)
- else
-
- -- No more instance decls, so all we have left is
- -- to deal with the deferred data type decls.
- getDeferredDataDecls `thenRn` \ data_decls ->
- mapRn rn_data_decl data_decls `thenRn` \ rn_data_decls ->
- returnRn (rn_data_decls ++ decls)
+-------------------------------------------------------
+-- closeDecls keeps going until the free-var set is empty
+closeDecls decls needed
+ | not (isEmptyFVs needed)
+ = slurpDecls decls needed `thenRn` \ (decls1, needed1) ->
+ closeDecls decls1 needed1
+
+ | otherwise
+ = getImportedRules `thenRn` \ rule_decls ->
+ case rule_decls of
+ [] -> returnRn decls -- No new rules, so we are done
+ other -> rnIfaceDecls decls emptyFVs rule_decls `thenRn` \ (decls1, needed1) ->
+ closeDecls decls1 needed1
+
+
+-------------------------------------------------------
+rnIfaceDecls :: [RenamedHsDecl] -> FreeVars
+ -> [(Module, RdrNameHsDecl)]
+ -> RnM d ([RenamedHsDecl], FreeVars)
+rnIfaceDecls decls fvs [] = returnRn (decls, fvs)
+rnIfaceDecls decls fvs (d:ds) = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) ->
+ rnIfaceDecls (new_decl:decls) (fvs1 `plusFV` fvs) ds
+
+rnIfaceDecl (mod, decl) = initIfaceRnMS mod (rnDecl decl)
- -- An unresolved name
- Just (name,necessity)
- -> -- Slurp its declaration, if any
--- traceRn (sep [ptext SLIT("Considering"), ppr PprDebug name]) `thenRn_`
- importDecl name necessity `thenRn` \ maybe_decl ->
- case maybe_decl of
- -- No declaration... (wired in thing or optional)
- Nothing -> closeDecls decls
+-------------------------------------------------------
+-- Augment decls with any decls needed by needed.
+-- Return also free vars of the new decls (only)
+slurpDecls decls needed
+ = go decls emptyFVs (nameSetToList needed)
+ where
+ go decls fvs [] = returnRn (decls, fvs)
+ go decls fvs (ref:refs) = slurpDecl decls fvs ref `thenRn` \ (decls1, fvs1) ->
+ go decls1 fvs1 refs
+
+-------------------------------------------------------
+slurpDecl decls fvs wanted_name
+ = importDecl wanted_name `thenRn` \ maybe_decl ->
+ case maybe_decl of
+ -- No declaration... (wired in thing)
+ Nothing -> returnRn (decls, fvs)
+
+ -- Found a declaration... rename it
+ Just decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) ->
+ returnRn (new_decl:decls, fvs1 `plusFV` fvs)
+\end{code}
- -- Found a declaration... rename it
- Just decl -> rn_iface_decl mod_name decl `thenRn` \ new_decl ->
- closeDecls (new_decl : decls)
- where
- (mod_name,_) = modAndOcc name
+%*********************************************************
+%* *
+\subsection{Extracting the `gates'}
+%* *
+%*********************************************************
-rn_iface_decl mod_name decl = initRnMS emptyRnEnv mod_name InterfaceMode (rnDecl decl)
- -- Notice that the rnEnv starts empty
+When we import a declaration like
+\begin{verbatim}
+ data T = T1 Wibble | T2 Wobble
+\end{verbatim}
+we don't want to treat @Wibble@ and @Wobble@ as gates
+{\em unless} @T1@, @T2@ respectively are mentioned by the user program.
+If only @T@ is mentioned
+we want only @T@ to be a gate;
+that way we don't suck in useless instance
+decls for (say) @Eq Wibble@, when they can't possibly be useful.
-rn_inst_decl (mod_name,decl) = rn_iface_decl mod_name (InstD decl)
+@getGates@ takes a newly imported (and renamed) decl, and the free
+vars of the source program, and extracts from the decl the gate names.
-rn_data_decl (tycon_name,ty_decl) = rn_iface_decl mod_name (TyD ty_decl)
- where
- (mod_name, _) = modAndOcc tycon_name
+\begin{code}
+getGates source_fvs (SigD (IfaceSig _ ty _ _))
+ = extractHsTyNames ty
+
+getGates source_fvs (TyClD (ClassDecl ctxt cls tvs _ sigs _ _ _ _ _ _))
+ = (delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) sigs)
+ (map getTyVarName tvs)
+ `addOneToNameSet` cls)
+ `plusFV` maybe_double
+ where
+ get (ClassOpSig n _ _ ty _)
+ | n `elemNameSet` source_fvs = extractHsTyNames ty
+ | otherwise = emptyFVs
+
+ -- If we load any numeric class that doesn't have
+ -- Int as an instance, add Double to the gates.
+ -- This takes account of the fact that Double might be needed for
+ -- defaulting, but we don't want to load Double (and all its baggage)
+ -- if the more exotic classes aren't used at all.
+ maybe_double | nameUnique cls `elem` fractionalClassKeys
+ = unitFV (getName doubleTyCon)
+ | otherwise
+ = emptyFVs
+
+getGates source_fvs (TyClD (TySynonym tycon tvs ty _))
+ = delListFromNameSet (extractHsTyNames ty)
+ (map getTyVarName tvs)
+ -- A type synonym type constructor isn't a "gate" for instance decls
+
+getGates source_fvs (TyClD (TyData _ ctxt tycon tvs cons _ _ _))
+ = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) cons)
+ (map getTyVarName tvs)
+ `addOneToNameSet` tycon
+ where
+ get (ConDecl n tvs ctxt details _)
+ | n `elemNameSet` source_fvs
+ -- If the constructor is method, get fvs from all its fields
+ = delListFromNameSet (get_details details `plusFV`
+ extractHsCtxtTyNames ctxt)
+ (map getTyVarName tvs)
+ get (ConDecl n tvs ctxt (RecCon fields) _)
+ -- Even if the constructor isn't mentioned, the fields
+ -- might be, as selectors. They can't mention existentially
+ -- bound tyvars (typechecker checks for that) so no need for
+ -- the deleteListFromNameSet part
+ = foldr (plusFV . get_field) emptyFVs fields
+
+ get other_con = emptyFVs
+
+ get_details (VanillaCon tys) = plusFVs (map get_bang tys)
+ get_details (InfixCon t1 t2) = get_bang t1 `plusFV` get_bang t2
+ get_details (RecCon fields) = plusFVs [get_bang t | (_, t) <- fields]
+ get_details (NewCon t _) = extractHsTyNames t
+
+ get_field (fs,t) | any (`elemNameSet` source_fvs) fs = get_bang t
+ | otherwise = emptyFVs
+
+ get_bang (Banged t) = extractHsTyNames t
+ get_bang (Unbanged t) = extractHsTyNames t
+ get_bang (Unpacked t) = extractHsTyNames t
+
+getGates source_fvs other_decl = emptyFVs
\end{code}
+@getWiredInGates@ is just like @getGates@, but it sees a wired-in @Name@
+rather than a declaration.
+
\begin{code}
-reportUnusedNames explicit_avail_names
- | not opt_WarnNameShadowing
- = returnRn ()
+getWiredInGates :: Name -> FreeVars
+getWiredInGates name -- No classes are wired in
+ | is_id = getWiredInGates_s (namesOfType (idType the_id))
+ | isSynTyCon the_tycon = getWiredInGates_s
+ (delListFromNameSet (namesOfType ty) (map getName tyvars))
+ | otherwise = unitFV name
+ where
+ maybe_wired_in_id = maybeWiredInIdName name
+ is_id = maybeToBool maybe_wired_in_id
+ maybe_wired_in_tycon = maybeWiredInTyConName name
+ Just the_id = maybe_wired_in_id
+ Just the_tycon = maybe_wired_in_tycon
+ (tyvars,ty) = getSynTyConDefn the_tycon
+
+getWiredInGates_s names = foldr (plusFV . getWiredInGates) emptyFVs (nameSetToList names)
+\end{code}
- | 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 (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))]
+\begin{code}
+getInstDeclGates (InstD (InstDecl inst_ty _ _ _ _)) = extractHsTyNames inst_ty
+getInstDeclGates other = emptyFVs
+\end{code}
+
+
+%*********************************************************
+%* *
+\subsection{Unused names}
+%* *
+%*********************************************************
+
+\begin{code}
+reportUnusedNames gbl_env avail_env (ExportEnv export_avails _ _) mentioned_names
+ = 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 -> WARN( True, text "reportUnusedName: not in avail_env" <+> 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_locals = [n | n <- defined_but_not_used, isLocallyDefined n]
+ bad_imps = [n | n <- defined_but_not_used, isUserImportedExplicitlyName n]
in
- (if null imported_unused
- then returnRn ()
- else addWarnRn pp_imp) `thenRn_`
-
- (if null local_unused
- then returnRn ()
- else addWarnRn pp_local)
-
-nameModule n = fst (modAndOcc n)
-
-rnStats :: [RenamedHsDecl] -> RnMG ()
-rnStats all_decls
- | opt_D_show_rn_trace ||
- opt_D_dump_rn ||
- opt_D_show_passes
- = getRnStats all_decls `thenRn` \ msg ->
- ioToRnMG (hPutStr stderr (show msg) >>
- hPutStr stderr "\n") `thenRn_`
- returnRn ()
-
- | otherwise = returnRn ()
+ warnUnusedLocalBinds bad_locals `thenRn_`
+ warnUnusedImports bad_imps
+
+rnDump :: [RenamedHsDecl] -- Renamed imported decls
+ -> [RenamedHsDecl] -- Renamed local decls
+ -> RnMG (IO ())
+rnDump imp_decls decls
+ | opt_D_dump_rn_trace ||
+ opt_D_dump_rn_stats ||
+ opt_D_dump_rn
+ = getRnStats imp_decls `thenRn` \ stats_msg ->
+
+ returnRn (printErrs stats_msg >>
+ dumpIfSet opt_D_dump_rn "Renamer:" (vcat (map ppr decls)))
+
+ | otherwise = returnRn (return ())
\end{code}
+
+%*********************************************************
+%* *
+\subsection{Statistics}
+%* *
+%*********************************************************
+
+\begin{code}
+getRnStats :: [RenamedHsDecl] -> RnMG SDoc
+getRnStats imported_decls
+ = getIfacesRn `thenRn` \ ifaces ->
+ let
+ n_mods = length [() | (_, _, Just _) <- eltsFM (iImpModInfo ifaces)]
+
+ decls_read = [decl | (_, avail, True, (_,decl)) <- nameEnvElts (iDecls ifaces),
+ -- Data, newtype, and class decls are in the decls_fm
+ -- under multiple names; the tycon/class, and each
+ -- constructor/class op too.
+ -- The 'True' selects just the 'main' decl
+ not (isLocallyDefined (availName avail))
+ ]
+
+ (cd_rd, dd_rd, nd_rd, sd_rd, vd_rd, _) = count_decls decls_read
+ (cd_sp, dd_sp, nd_sp, sd_sp, vd_sp, id_sp) = count_decls imported_decls
+
+ unslurped_insts = iInsts ifaces
+ inst_decls_unslurped = length (bagToList unslurped_insts)
+ inst_decls_read = id_sp + inst_decls_unslurped
+
+ stats = vcat
+ [int n_mods <+> text "interfaces read",
+ hsep [ int cd_sp, text "class decls imported, out of",
+ int cd_rd, text "read"],
+ hsep [ int dd_sp, text "data decls imported, out of",
+ int dd_rd, text "read"],
+ hsep [ int nd_sp, text "newtype decls imported, out of",
+ int nd_rd, text "read"],
+ hsep [int sd_sp, text "type synonym decls imported, out of",
+ int sd_rd, text "read"],
+ hsep [int vd_sp, text "value signatures imported, out of",
+ int vd_rd, text "read"],
+ hsep [int id_sp, text "instance decls imported, out of",
+ int inst_decls_read, text "read"],
+ text "cls dcls slurp" <+> fsep (map (ppr . tyClDeclName)
+ [d | TyClD d <- imported_decls, isClassDecl d]),
+ text "cls dcls read" <+> fsep (map (ppr . tyClDeclName)
+ [d | TyClD d <- decls_read, isClassDecl d])]
+ in
+ returnRn (hcat [text "Renamer stats: ", stats])
+
+count_decls decls
+ = (class_decls,
+ data_decls,
+ newtype_decls,
+ syn_decls,
+ val_decls,
+ inst_decls)
+ where
+ tycl_decls = [d | TyClD d <- decls]
+ (class_decls, data_decls, newtype_decls, syn_decls) = countTyClDecls tycl_decls
+
+ val_decls = length [() | SigD _ <- decls]
+ inst_decls = length [() | InstD _ <- decls]
+\end{code}
+