X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRename.lhs;h=377e4baf06f4c77e7f5223488494ee19d836f31a;hb=00eefb90925f224c1e22963df2a00d70fe934d5f;hp=c5b881ac6fd3e09f74fb10897592285d637b7aae;hpb=a77abe6a30ea2763cfa1c0ca83cdce9b7200ced2;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/Rename.lhs b/ghc/compiler/rename/Rename.lhs index c5b881a..377e4ba 100644 --- a/ghc/compiler/rename/Rename.lhs +++ b/ghc/compiler/rename/Rename.lhs @@ -1,261 +1,578 @@ -% -% (c) The GRASP Project, Glasgow University, 1992-1996 -% -\section[Rename]{Renaming and dependency analysis passes} - -\begin{code} -#include "HsVersions.h" - -module Rename ( renameModule ) where - -import PreludeGlaST ( thenPrimIO, newVar, MutableVar(..) ) - -import Ubiq - -import HsSyn -import RdrHsSyn ( RdrNameHsModule(..), RdrNameImportDecl(..) ) -import RnHsSyn ( RnName, RenamedHsModule(..), isRnTyConOrClass, isRnWired ) - ---ToDo:rm: all for debugging only -import Maybes -import Name -import Outputable -import RnIfaces -import PprStyle -import Pretty -import FiniteMap -import Util (pprPanic, pprTrace) - -import ParseUtils ( ParsedIface(..), RdrIfaceDecl(..), RdrIfaceInst(..) ) -import RnMonad -import RnNames ( getGlobalNames, GlobalNameInfo(..) ) -import RnSource ( rnSource ) -import RnIfaces ( findHiFiles, rnIfaces, finalIfaceInfo, VersionInfo(..) ) -import RnUtils ( RnEnv(..), extendGlobalRnEnv, emptyRnEnv, multipleOccWarn ) - -import Bag ( isEmptyBag, unionBags, unionManyBags, bagToList, listToBag ) -import CmdLineOpts ( opt_HiDirList, opt_SysHiDirList ) -import ErrUtils ( Error(..), Warning(..) ) -import FiniteMap ( emptyFM, eltsFM, fmToList, lookupFM{-ToDo:rm-} ) -import Maybes ( catMaybes ) -import Name ( isLocallyDefined, mkBuiltinName, Name, RdrName(..) ) -import PrelInfo ( BuiltinNames(..), BuiltinKeys(..) ) -import PrelMods ( pRELUDE ) -import UniqFM ( emptyUFM, lookupUFM, addListToUFM_C, eltsUFM ) -import UniqSupply ( splitUniqSupply ) -import Util ( panic, assertPanic ) -\end{code} - -\begin{code} -renameModule :: BuiltinNames - -> BuiltinKeys - -> UniqSupply - -> RdrNameHsModule - - -> IO (RenamedHsModule, -- output, after renaming - RnEnv, -- final env (for renaming derivings) - [Module], -- imported modules; for profiling - - VersionInfo, -- version info; for usage - [Module], -- instance modules; for iface - - Bag Error, - Bag Warning) -\end{code} - -ToDo: May want to arrange to return old interface for this module! -ToDo: Builtin names which must be read. -ToDo: Deal with instances (instance version, this module on instance list ???) - -\begin{code} -renameModule b_names b_keys us - input@(HsModule mod _ _ imports _ _ _ _ _ _ _ _ _ _) - - = --pprTrace "builtins:\n" (case b_names of { (builtin_ids, builtin_tcs) -> - -- ppAboves [ ppCat (map ppPStr (keysFM builtin_ids)) - -- , ppCat (map ppPStr (keysFM builtin_tcs)) - -- , ppCat (map ppPStr (keysFM b_keys)) - -- ]}) $ - - findHiFiles opt_HiDirList opt_SysHiDirList >>= \ hi_files -> - newVar (emptyFM, hi_files){-init iface cache-} `thenPrimIO` \ iface_cache -> - - fixIO ( \ ~(_, _, _, _, rec_occ_fm, rec_export_fn) -> - let - rec_occ_fn :: Name -> [RdrName] - rec_occ_fn n = case lookupUFM rec_occ_fm n of - Nothing -> [] - Just (rn,occs) -> occs - - global_name_info = (b_names, b_keys, rec_export_fn, rec_occ_fn) - in - getGlobalNames iface_cache global_name_info us1 input >>= - \ (occ_env, imp_mods, unqual_imps, imp_fixes, top_errs, top_warns) -> - - if not (isEmptyBag top_errs) then - return (rn_panic, rn_panic, top_errs, top_warns, emptyUFM, rn_panic) - else - - -- No top-level name errors so rename source ... - case initRn True mod occ_env us2 - (rnSource imp_mods unqual_imps imp_fixes input) of { - ((rn_module, export_fn, src_occs), src_errs, src_warns) -> - - --pprTrace "renameModule:" (ppCat (map (ppr PprDebug . fst) (bagToList src_occs))) $ - - let - occ_fm :: UniqFM (RnName, [RdrName]) - - occ_list = [ (rn,(rn,[occ])) | (rn,occ) <- bagToList src_occs] - occ_fm = addListToUFM_C insert_occ emptyUFM occ_list - - insert_occ (rn,olds) (rn',[new]) = (rn, insert new olds) - - insert new [] = [new] - insert new xxs@(x:xs) = case cmp new x of LT_ -> new : xxs - EQ_ -> xxs - GT__ -> x : insert new xs - - occ_warns = map multipleOccWarn (filter multiple_occs (eltsUFM occ_fm)) - multiple_occs (rn, (o1:o2:_)) = True - multiple_occs _ = False - in - return (rn_module, imp_mods, - top_errs `unionBags` src_errs, - top_warns `unionBags` src_warns `unionBags` listToBag occ_warns, - occ_fm, export_fn) - - }) >>= \ (rn_module, imp_mods, errs_so_far, warns_so_far, occ_fm, _) -> - - if not (isEmptyBag errs_so_far) then - return (rn_panic, rn_panic, rn_panic, rn_panic, rn_panic, errs_so_far, warns_so_far) - else - - -- No errors renaming source so rename the interfaces ... - let - -- split up all names that occurred in the source; between - -- those that are defined therein and those merely mentioned. - -- We also divide by tycon/class and value names (as usual). - - occ_rns = [ rn | (rn,_) <- eltsUFM occ_fm ] - -- all occurrence names, from this module and imported - - (defined_here, defined_elsewhere) - = partition isLocallyDefined occ_rns - - (_, imports_used) - = partition isRnWired defined_elsewhere - - (def_tcs, def_vals) = partition isRnTyConOrClass defined_here - (occ_tcs, occ_vals) = partition isRnTyConOrClass occ_rns - -- the occ stuff includes *all* occurrences, - -- including those for which we have definitions - - (orig_def_env, orig_def_dups) - = extendGlobalRnEnv emptyRnEnv (map pair_orig def_vals) - (map pair_orig def_tcs) - (orig_occ_env, orig_occ_dups) - = extendGlobalRnEnv emptyRnEnv (map pair_orig occ_vals) - (map pair_orig occ_tcs) - - pair_orig rn = (origName rn, rn) - - -- we must ensure that the definitions of things in the BuiltinKey - -- table which may be *required* by the typechecker etc are read. - - must_haves - = [ name_fn (mkBuiltinName u pRELUDE str) - | (str, (u, name_fn)) <- fmToList b_keys, - str `notElem` [ SLIT("main"), SLIT("mainPrimIO")] ] - in - ASSERT (isEmptyBag orig_occ_dups) - ASSERT (isEmptyBag orig_def_dups) - - rnIfaces iface_cache imp_mods us3 orig_def_env orig_occ_env - rn_module (must_haves ++ imports_used) >>= - \ (rn_module_with_imports, final_env, - (implicit_val_fm, implicit_tc_fm), - (iface_errs, iface_warns)) -> - let - all_imports_used = imports_used ++ eltsFM implicit_tc_fm - ++ eltsFM implicit_val_fm - in - finalIfaceInfo iface_cache all_imports_used imp_mods >>= - \ (version_info, instance_mods) -> - - return (rn_module_with_imports, - final_env, - imp_mods, - version_info, - instance_mods, - errs_so_far `unionBags` iface_errs, - warns_so_far `unionBags` iface_warns) - where - rn_panic = panic "renameModule: aborted with errors" - - (us1, us') = splitUniqSupply us - (us2, us3) = splitUniqSupply us' -\end{code} - -\begin{code} -pprPIface (ParsedIface m v mv lcm exm ims lfx ltdm lvdm lids ldp) - = ppAboves [ - ppCat [ppPStr SLIT("interface"), ppPStr m, ppInt v, - case mv of { Nothing -> ppNil; Just n -> ppInt n }], - - ppPStr SLIT("__versions__"), - ppAboves [ ppCat[ppPStr n, ppInt v] | (n,v) <- fmToList lcm ], - - ppPStr SLIT("__exports__"), - ppAboves [ ppBesides[ppPStr n, ppSP, ppr PprDebug rn, - case ex of {ExportAll -> ppStr "(..)"; _ -> ppNil}] - | (n,(rn,ex)) <- fmToList exm ], - - pp_ims (bagToList ims), - pp_fixities lfx, - pp_decls ltdm lvdm, - pp_insts (bagToList lids), - pp_pragmas ldp - ] - where - pp_ims [] = ppNil - pp_ims ms = ppAbove (ppPStr SLIT("__instance_modules__")) - (ppCat (map ppPStr ms)) - - pp_fixities fx - | isEmptyFM fx = ppNil - | otherwise = ppAboves (ppPStr SLIT("__fixities__") - : [ ppr PprDebug fix | (n, fix) <- fmToList fx]) - - pp_decls tds vds = ppAboves (ppPStr SLIT("__declarations__") - : [ pprRdrIfaceDecl d | (n, d) <- fmToList tds ++ fmToList vds]) - - pp_insts [] = ppNil - pp_insts is = ppAboves (ppPStr SLIT("__instances__") - : [ pprRdrInstDecl i | i <- is]) - - pp_pragmas ps | isEmptyFM ps = ppNil - | otherwise = panic "Rename.pp_pragmas" - -pprRdrIfaceDecl (TypeSig tc _ decl) - = ppBesides [ppStr "tycon=", ppr PprDebug tc, ppStr "; ", ppr PprDebug decl] - -pprRdrIfaceDecl (NewTypeSig tc dc _ decl) - = ppBesides [ppStr "tycon=", ppr PprDebug tc, ppStr "; datacon=", ppr PprDebug dc, - ppStr "; ", ppr PprDebug decl] - -pprRdrIfaceDecl (DataSig tc dcs dfs _ decl) - = ppBesides [ppStr "tycon=", ppr PprDebug tc, ppStr "; datacons=", ppr PprDebug dcs, - ppStr "; fields=", ppr PprDebug dfs, ppStr "; ", ppr PprDebug decl] - -pprRdrIfaceDecl (ClassSig c ops _ decl) - = ppBesides [ppStr "class=", ppr PprDebug c, ppStr "; ops=", ppr PprDebug ops, - ppStr "; ", ppr PprDebug decl] - -pprRdrIfaceDecl (ValSig f _ ty) - = ppBesides [ppr PprDebug f, ppStr " :: ", ppr PprDebug ty] - -pprRdrInstDecl (InstSig c t _ decl) - = ppBesides [ppStr "class=", ppr PprDebug c, ppStr " type=", ppr PprDebug t, ppStr "; ", - ppr PprDebug decl] -\end{code} +% +% (c) The GRASP Project, Glasgow University, 1992-1998 +% +\section[Rename]{Renaming and dependency analysis passes} + +\begin{code} +module Rename ( renameModule ) where + +#include "HsVersions.h" + +import HsSyn +import RdrHsSyn ( RdrNameHsModule ) +import RnHsSyn ( RenamedHsModule, RenamedHsDecl, + extractHsTyNames, extractHsCtxtTyNames + ) + +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 ( rnSourceDecls, rnDecl ) +import RnIfaces ( getImportedInstDecls, importDecl, getImportVersions, + getImportedRules, loadHomeInterface, getSlurped + ) +import RnEnv ( availName, availNames, availsToNameSet, + warnUnusedTopNames, mapFvRn, + FreeVars, plusFVs, plusFV, unitFV, emptyFVs, isEmptyFVs + ) +import Module ( Module, ModuleName, pprModule, mkSearchPath, mkThisModule ) +import Name ( Name, isLocallyDefined, + NamedThing(..), ImportReason(..), Provenance(..), + pprOccName, nameOccName, + getNameProvenance, occNameUserString, + maybeWiredInTyConName, maybeWiredInIdName, isWiredInName + ) +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 ) +import Type ( namesOfType, funTyCon ) +import ErrUtils ( pprBagOfErrors, pprBagOfWarnings, + doIfSet, dumpIfSet, ghcExit + ) +import BasicTypes ( NewOrData(..) ) +import Bag ( isEmptyBag, bagToList ) +import FiniteMap ( fmToList, delListFromFM, addToFM, sizeFM, eltsFM ) +import UniqSupply ( UniqSupply ) +import Util ( equivClasses ) +import Maybes ( maybeToBool ) +import Outputable +\end{code} + + + +\begin{code} +renameModule :: UniqSupply + -> RdrNameHsModule + -> 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, rn_errs_bag, rn_warns_bag) -> + + -- Check for warnings + doIfSet (not (isEmptyBag rn_warns_bag)) + (printErrs (pprBagOfWarnings rn_warns_bag)) >> + + -- Check for errors; exit if so + doIfSet (not (isEmptyBag rn_errs_bag)) + (printErrs (pprBagOfErrors rn_errs_bag) >> + ghcExit 1 + ) >> + + -- Dump output, if any + (case maybe_rn_stuff of + Nothing -> return () + Just results@(_, rn_mod, _, _, _) + -> dumpIfSet opt_D_dump_rn "Renamer:" + (ppr rn_mod) + ) >> + + -- Return results + return maybe_rn_stuff +\end{code} + + +\begin{code} +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, gbl_env, fixity_env, global_avail_env) = maybe_stuff + in + + -- RENAME THE SOURCE + initRnMS gbl_env fixity_env SourceMode ( + rnSourceDecls local_decls + ) `thenRn` \ (rn_local_decls, source_fvs) -> + + -- SLURP IN ALL THE NEEDED DECLARATIONS + let + real_source_fvs = implicitFVs mod_name `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 -> + + -- 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` \ my_usages -> + getNameSupplyRn `thenRn` \ name_supply -> + + -- REPORT UNUSED NAMES + reportUnusedNames gbl_env global_avail_env + export_env + source_fvs `thenRn_` + + -- RETURN THE RENAMED MODULE + let + has_orphans = any isOrphanDecl rn_local_decls + direct_import_mods = [mod | ImportDecl mod _ _ _ _ _ <- imports] + rn_all_decls = rn_imp_decls ++ rn_local_decls + renamed_module = HsModule mod_name vers + trashed_exports trashed_imports + rn_all_decls + loc + in + rnStats rn_imp_decls `thenRn_` + returnRn (Just (mkThisModule mod_name, + renamed_module, + (has_orphans, my_usages, export_env), + name_supply, + direct_import_mods)) + where + trashed_exports = {-trace "rnSource:trashed_exports"-} Nothing + trashed_imports = {-trace "rnSource:trashed_imports"-} [] +\end{code} + +@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} +implicitFVs mod_name + = implicit_main `plusFV` + mkNameSet default_tys `plusFV` + mkNameSet 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 always appear explicitly. + -- [The () one is a GHC extension for defaulting CCall results.] + -- ALSO: funTyCon, since it occurs implicitly everywhere! + -- (we don't want to be bothered with making funTyCon a + -- free var at every function application!) + default_tys = [getName intTyCon, getName doubleTyCon, + getName unitTyCon, getName funTyCon, getName boolTyCon] + + -- Add occurrences for IO or PrimIO + implicit_main | mod_name == mAIN_Name + || mod_name == pREL_MAIN_Name = unitFV ioTyCon_NAME + | otherwise = emptyFVs +\end{code} + +\begin{code} +isOrphanDecl (InstD (InstDecl inst_ty _ _ _ _)) + = not (foldNameSet ((||) . isLocallyDefined) False (extractHsTyNames inst_ty)) +isOrphanDecl (RuleD (RuleDecl _ _ _ lhs _ _)) + = check lhs + where + check (HsVar v) = not (isLocallyDefined v) + check (HsApp f a) = check f && check a + check other = True +isOrphanDecl other = False +\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` \ (decls1, needed1, inst_gates) -> + + -- Now we can get the instance decls + slurpInstDecls decls1 needed1 inst_gates `thenRn` \ (decls2, needed2) -> + + -- And finally get everything else + closeDecls decls2 needed2 + +------------------------------------------------------- +slurpSourceRefs :: NameSet -- Variables defined in source + -> FreeVars -- Variables referenced in source + -> RnMG ([RenamedHsDecl], + FreeVars, -- Un-satisfied needs + FreeVars) -- "Gates" +-- The declaration (and hence home module) of each gate has +-- already been loaded + +slurpSourceRefs source_binders source_fvs + = go [] -- Accumulating decls + emptyFVs -- Unsatisfied needs + source_fvs -- Accumulating gates + (nameSetToList source_fvs) -- Gates whose defn hasn't been loaded yet + where + go decls fvs gates [] + = returnRn (decls, fvs, gates) + + go decls fvs gates (wanted_name:refs) + | isWiredInName wanted_name + = load_home wanted_name `thenRn_` + go decls fvs (gates `plusFV` getWiredInGates wanted_name) refs + + | otherwise + = importDecl wanted_name `thenRn` \ maybe_decl -> + case maybe_decl of + -- No declaration... (already slurped, or local) + Nothing -> go decls fvs gates refs + Just decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) -> + let + new_gates = getGates source_fvs new_decl + in + go (new_decl : decls) + (fvs1 `plusFV` fvs) + (gates `plusFV` new_gates) + (nameSetToList new_gates ++ 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 + +------------------------------------------------------- +-- slurpInstDecls imports appropriate instance decls. +-- It has to incorporate a loop, 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. + +slurpInstDecls decls needed gates + | isEmptyFVs gates + = returnRn (decls, needed) + + | otherwise + = getImportedInstDecls gates `thenRn` \ inst_decls -> + rnInstDecls decls needed emptyFVs inst_decls `thenRn` \ (decls1, needed1, gates1) -> + slurpInstDecls decls1 needed1 gates1 + where + 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 + + +------------------------------------------------------- +-- 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) + + +------------------------------------------------------- +-- 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} + + +%********************************************************* +%* * +\subsection{Extracting the 'gates'} +%* * +%********************************************************* + +When we import a declaration like + + data T = T1 Wibble | T2 Wobble + +we don't want to treat Wibble and Wobble as gates *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. + +@getGates@ takes a newly imported (and renamed) decl, and the free +vars of the source program, and extracts from the decl the gate names. + +\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 + where + get (ClassOpSig n _ ty _) + | n `elemNameSet` source_fvs = extractHsTyNames ty + | 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} +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} + +\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 + | not (opt_WarnUnusedBinds || opt_WarnUnusedImports) + = returnRn () + + | otherwise + = 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 + warnUnusedTopNames bad_guys `thenRn_` + returnRn () + +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 imp_decls + | opt_D_dump_rn_trace || + opt_D_dump_rn_stats || + opt_D_dump_rn + = getRnStats imp_decls `thenRn` \ msg -> + ioToRnM (printErrs msg) `thenRn_` + returnRn () + + | otherwise = returnRn () +\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} +