% % (c) The GRASP/AQUA Project, Glasgow University, 1992-1996 % \section[RnIfaces]{Cacheing and Renaming of Interfaces} \begin{code} module RnIfaces ( getInterfaceExports, getImportedInstDecls, getSpecialInstModules, getDeferredDataDecls, importDecl, recordSlurp, getImportVersions, getSlurpedNames, getRnStats, checkUpToDate, getDeclBinders, mkSearchPath ) where #include "HsVersions.h" import CmdLineOpts ( opt_PruneTyDecls, opt_PruneInstDecls, opt_IgnoreIfacePragmas ) import HsSyn ( HsDecl(..), TyDecl(..), ClassDecl(..), InstDecl(..), IfaceSig(..), HsType(..), ConDecl(..), IE(..), ConDetails(..), Sig(..), hsDeclName ) import HsPragmas ( noGenPragmas ) import BasicTypes ( Version, NewOrData(..), IfaceFlavour(..) ) import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameTyDecl, RdrName(..), rdrNameOcc ) import RnEnv ( newImportedGlobalName, addImplicitOccsRn, ifaceFlavour, availName, availNames, addAvailToNameSet, pprAvail ) import RnSource ( rnHsSigType ) import RnMonad import RnHsSyn ( RenamedHsDecl ) import ParseIface ( parseIface, IfaceStuff(..) ) import FiniteMap ( FiniteMap, sizeFM, emptyFM, unitFM, delFromFM, lookupFM, addToFM, addToFM_C, addListToFM, fmToList, eltsFM ) import Name ( Name {-instance NamedThing-}, Provenance, OccName(..), nameModule, occNameString, moduleString, pprModule, isLocallyDefined, NameSet(..), emptyNameSet, unionNameSets, nameSetToList, minusNameSet, mkNameSet, elemNameSet, nameUnique, addOneToNameSet, isWiredInName, maybeWiredInTyConName, maybeWiredInIdName, NamedThing(..) ) import Id ( GenId, Id(..), idType, dataConTyCon, isAlgCon ) import TyCon ( TyCon, tyConDataCons, isSynTyCon, getSynTyConDefn ) import Type ( namesOfType ) import TyVar ( GenTyVar ) import SrcLoc ( mkSrcLoc, SrcLoc ) import PrelMods ( gHC__ ) import PrelInfo ( cCallishTyKeys ) import Bag import Maybes ( MaybeErr(..), expectJust, maybeToBool ) import ListSetOps ( unionLists ) import Outputable import Unique ( Unique ) import StringBuffer ( StringBuffer, hGetStringBuffer, freeStringBuffer ) import FastString ( mkFastString ) import Outputable import IO ( isDoesNotExistError ) import List ( nub ) \end{code} %********************************************************* %* * \subsection{Statistics} %* * %********************************************************* \begin{code} getRnStats :: [RenamedHsDecl] -> RnMG SDoc getRnStats all_decls = getIfacesRn `thenRn` \ ifaces -> let Ifaces this_mod mod_map decls_fm all_names imp_names (unslurped_insts,_) deferred_data_decls inst_mods = ifaces n_mods = sizeFM mod_map decls_imported = filter is_imported_decl all_decls decls_read = [decl | (name, (_, avail, decl)) <- fmToList decls_fm, name == availName avail, -- Data, newtype, and class decls are in the decls_fm -- under multiple names; the tycon/class, and each -- constructor/class op too. not (isLocallyDefined name) ] (cd_rd, dd_rd, add_rd, nd_rd, and_rd, sd_rd, vd_rd, _) = count_decls decls_read (cd_sp, dd_sp, add_sp, nd_sp, and_sp, sd_sp, vd_sp, id_sp) = count_decls decls_imported 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 (of which", int add_sp, text "abstractly), out of", int dd_rd, text "read"], hsep [int nd_sp, text "newtype decls imported (of which", int and_sp, text "abstractly), 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"] ] in returnRn (hcat [text "Renamer stats: ", stats]) is_imported_decl (DefD _) = False is_imported_decl (ValD _) = False is_imported_decl decl = not (isLocallyDefined (hsDeclName decl)) count_decls decls = -- pprTrace "count_decls" (ppr decls -- -- $$ -- text "=========" -- $$ -- ppr imported_decls -- ) $ (class_decls, data_decls, abstract_data_decls, newtype_decls, abstract_newtype_decls, syn_decls, val_decls, inst_decls) where class_decls = length [() | ClD _ <- decls] data_decls = length [() | TyD (TyData DataType _ _ _ _ _ _ _) <- decls] newtype_decls = length [() | TyD (TyData NewType _ _ _ _ _ _ _) <- decls] abstract_data_decls = length [() | TyD (TyData DataType _ _ _ [] _ _ _) <- decls] abstract_newtype_decls = length [() | TyD (TyData NewType _ _ _ [] _ _ _) <- decls] syn_decls = length [() | TyD (TySynonym _ _ _ _) <- decls] val_decls = length [() | SigD _ <- decls] inst_decls = length [() | InstD _ <- decls] \end{code} %********************************************************* %* * \subsection{Loading a new interface file} %* * %********************************************************* \begin{code} loadInterface :: SDoc -> Module -> IfaceFlavour -> RnMG Ifaces loadInterface doc_str load_mod as_source = getIfacesRn `thenRn` \ ifaces -> let Ifaces this_mod mod_map decls all_names imp_names (insts, tycls_names) deferred_data_decls inst_mods = ifaces in -- CHECK WHETHER WE HAVE IT ALREADY case lookupFM mod_map load_mod of { Just (hif, _, _, _) | hif `as_good_as` as_source -> -- Already in the cache; don't re-read it returnRn ifaces ; other -> -- READ THE MODULE IN findAndReadIface doc_str load_mod as_source `thenRn` \ read_result -> case read_result of { -- Check for not found Nothing -> -- Not found, so add an empty export env to the Ifaces map -- so that we don't look again let new_mod_map = addToFM mod_map load_mod (HiFile, 0, [],[]) new_ifaces = Ifaces this_mod new_mod_map decls all_names imp_names (insts, tycls_names) deferred_data_decls inst_mods in setIfacesRn new_ifaces `thenRn_` failWithRn new_ifaces (noIfaceErr load_mod) ; -- Found and parsed! Just (ParsedIface _ mod_vers usages exports rd_inst_mods fixs rd_decls rd_insts) -> -- LOAD IT INTO Ifaces -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined --- names is done correctly (notably, whether this is an .hi file or .hi-boot file). -- If we do loadExport first the wrong info gets into the cache (unless we -- explicitly tag each export which seems a bit of a bore) foldlRn (loadDecl load_mod as_source) decls rd_decls `thenRn` \ new_decls -> mapRn loadExport exports `thenRn` \ avails_s -> foldlRn (loadInstDecl load_mod) insts rd_insts `thenRn` \ new_insts -> let mod_details = (as_source, mod_vers, concat avails_s, fixs) -- Exclude this module from the "special-inst" modules new_inst_mods = inst_mods `unionLists` (filter (/= this_mod) rd_inst_mods) new_ifaces = Ifaces this_mod (addToFM mod_map load_mod mod_details) new_decls all_names imp_names (new_insts, tycls_names) deferred_data_decls new_inst_mods in setIfacesRn new_ifaces `thenRn_` returnRn new_ifaces }} as_good_as HiFile any = True as_good_as any HiBootFile = True as_good_as _ _ = False loadExport :: ExportItem -> RnMG [AvailInfo] loadExport (mod, hif, entities) = mapRn load_entity entities where new_name occ = newImportedGlobalName mod occ hif load_entity (Avail occ) = new_name occ `thenRn` \ name -> returnRn (Avail name) load_entity (AvailTC occ occs) = new_name occ `thenRn` \ name -> mapRn new_name occs `thenRn` \ names -> returnRn (AvailTC name names) loadDecl :: Module -> IfaceFlavour -> DeclsMap -> (Version, RdrNameHsDecl) -> RnMG DeclsMap loadDecl mod as_source decls_map (version, decl) = getDeclBinders new_implicit_name decl `thenRn` \ avail -> returnRn (addListToFM decls_map [(name,(version,avail,decl')) | name <- availNames avail] ) where {- If a signature decl is being loaded and we're ignoring interface pragmas, toss away unfolding information. Also, if the signature is loaded from a module we're importing from source, we do the same. This is to avoid situations when compiling a pair of mutually recursive modules, peering at unfolding info in the interface file of the other, e.g., you compile A, it looks at B's interface file and may as a result change it's interface file. Hence, B is recompiled, maybe changing it's interface file, which will the ufolding info used in A to become invalid. Simple way out is to just ignore unfolding info. -} decl' = case decl of SigD (IfaceSig name tp ls loc) | from_hi_boot || opt_IgnoreIfacePragmas -> SigD (IfaceSig name tp [] loc) _ -> decl new_implicit_name rdr_name loc = newImportedGlobalName mod (rdrNameOcc rdr_name) as_source from_hi_boot = case as_source of HiBootFile -> True other -> False loadInstDecl :: Module -> Bag IfaceInst -> RdrNameInstDecl -> RnMG (Bag IfaceInst) loadInstDecl mod_name insts decl@(InstDecl inst_ty binds uprags dfun_name src_loc) = -- Find out what type constructors and classes are "gates" for the -- instance declaration. If all these "gates" are slurped in then -- we should slurp the instance decl too. -- -- We *don't* want to count names in the context part as gates, though. -- For example: -- instance Foo a => Baz (T a) where ... -- -- Here the gates are Baz and T, but *not* Foo. let munged_inst_ty = case inst_ty of HsForAllTy tvs cxt ty -> HsForAllTy tvs [] ty HsPreForAllTy cxt ty -> HsPreForAllTy [] ty other -> inst_ty in -- We find the gates by renaming the instance type with in a -- and returning the occurrence pool. initRnMS emptyRnEnv mod_name vanillaInterfaceMode ( findOccurrencesRn (rnHsSigType (text "an instance decl") munged_inst_ty) ) `thenRn` \ gate_names -> returnRn (((mod_name, decl), gate_names) `consBag` insts) vanillaInterfaceMode = InterfaceMode Compulsory (\_ -> False) \end{code} %******************************************************** %* * \subsection{Loading usage information} %* * %******************************************************** \begin{code} checkUpToDate :: Module -> RnMG Bool -- True <=> no need to recompile checkUpToDate mod_name = findAndReadIface doc_str mod_name HiFile `thenRn` \ read_result -> -- CHECK WHETHER WE HAVE IT ALREADY case read_result of Nothing -> -- Old interface file not found, so we'd better bail out traceRn (sep [ptext SLIT("Didnt find old iface"), pprModule mod_name]) `thenRn_` returnRn False Just (ParsedIface _ _ usages _ _ _ _ _) -> -- Found it, so now check it checkModUsage usages where -- Only look in current directory, with suffix .hi doc_str = sep [ptext SLIT("need usage info from"), pprModule mod_name] checkModUsage [] = returnRn True -- Yes! Everything is up to date! checkModUsage ((mod, hif, old_mod_vers, whats_imported) : rest) = loadInterface doc_str mod hif `thenRn` \ ifaces -> let Ifaces _ mod_map decls _ _ _ _ _ = ifaces maybe_new_mod_vers = lookupFM mod_map mod Just (_, new_mod_vers, _, _) = maybe_new_mod_vers in -- If we can't find a version number for the old module then -- bail out saying things aren't up to date if not (maybeToBool maybe_new_mod_vers) then traceRn (sep [ptext SLIT("Can't find version number for module"), pprModule mod]) `thenRn_` returnRn False else -- If the module version hasn't changed, just move on if new_mod_vers == old_mod_vers then traceRn (sep [ptext SLIT("Module version unchanged:"), pprModule mod]) `thenRn_` checkModUsage rest else traceRn (sep [ptext SLIT("Module version has changed:"), pprModule mod]) `thenRn_` -- Module version changed, so check entities inside -- If the usage info wants to say "I imported everything from this module" -- it does so by making whats_imported equal to Everything -- In that case, we must recompile case whats_imported of { Everything -> traceRn (ptext SLIT("...and I needed the whole module")) `thenRn_` returnRn False; -- Bale out Specifically old_local_vers -> -- Non-empty usage list, so check item by item checkEntityUsage mod decls old_local_vers `thenRn` \ up_to_date -> if up_to_date then traceRn (ptext SLIT("...but the bits I use haven't.")) `thenRn_` checkModUsage rest -- This one's ok, so check the rest else returnRn False -- This one failed, so just bail out now } where doc_str = sep [ptext SLIT("need version info for"), pprModule mod] checkEntityUsage mod decls [] = returnRn True -- Yes! All up to date! checkEntityUsage mod decls ((occ_name,old_vers) : rest) = newImportedGlobalName mod occ_name HiFile `thenRn` \ name -> case lookupFM decls name of Nothing -> -- We used it before, but it ain't there now putDocRn (sep [ptext SLIT("No longer exported:"), ppr name]) `thenRn_` returnRn False Just (new_vers,_,_) -- It's there, but is it up to date? | new_vers == old_vers -- Up to date, so check the rest -> checkEntityUsage mod decls rest | otherwise -- Out of date, so bale out -> putDocRn (sep [ptext SLIT("Out of date:"), ppr name]) `thenRn_` returnRn False \end{code} %********************************************************* %* * \subsection{Getting in a declaration} %* * %********************************************************* \begin{code} importDecl :: Occurrence -> RnSMode -> RnMG (Maybe RdrNameHsDecl) -- Returns Nothing for a wired-in or already-slurped decl importDecl (name, loc) mode = checkSlurped name `thenRn` \ already_slurped -> if already_slurped then -- traceRn (sep [text "Already slurped:", ppr name]) `thenRn_` returnRn Nothing -- Already dealt with else if isWiredInName name then getWiredInDecl name mode else getIfacesRn `thenRn` \ ifaces -> let Ifaces this_mod _ _ _ _ _ _ _ = ifaces mod = nameModule name in if mod == this_mod then -- Don't bring in decls from pprTrace "importDecl wierdness:" (ppr name) $ returnRn Nothing -- the renamed module's own interface file -- else getNonWiredInDecl name loc mode \end{code} \begin{code} getNonWiredInDecl :: Name -> SrcLoc -> RnSMode -> RnMG (Maybe RdrNameHsDecl) getNonWiredInDecl needed_name loc mode = traceRn doc_str `thenRn_` loadInterface doc_str mod (ifaceFlavour needed_name) `thenRn` \ (Ifaces _ _ decls _ _ _ _ _) -> case lookupFM decls needed_name of -- Special case for data/newtype type declarations Just (version, avail, TyD ty_decl) | is_data_or_newtype ty_decl -> getNonWiredDataDecl needed_name version avail ty_decl `thenRn` \ (avail', maybe_decl) -> recordSlurp (Just version) necessity avail' `thenRn_` returnRn maybe_decl Just (version,avail,decl) -> recordSlurp (Just version) necessity avail `thenRn_` returnRn (Just decl) Nothing -> -- Can happen legitimately for "Optional" occurrences case necessity of { Optional -> addWarnRn (getDeclWarn needed_name loc); other -> addErrRn (getDeclErr needed_name loc) } `thenRn_` returnRn Nothing where necessity = modeToNecessity mode doc_str = sep [ptext SLIT("need decl for"), ppr needed_name, ptext SLIT("needed at"), ppr loc] mod = nameModule needed_name is_data_or_newtype (TyData _ _ _ _ _ _ _ _) = True is_data_or_newtype other = False \end{code} @getWiredInDecl@ maps a wired-in @Name@ to what it makes available. It behaves exactly as if the wired in decl were actually in an interface file. Specifically, * if the wired-in name is a data type constructor or a data constructor, it brings in the type constructor and all the data constructors; and marks as "occurrences" any free vars of the data con. * similarly for synonum type constructor * if the wired-in name is another wired-in Id, it marks as "occurrences" the free vars of the Id's type. * it loads the interface file for the wired-in thing for the sole purpose of making sure that its instance declarations are available All this is necessary so that we know all types that are "in play", so that we know just what instances to bring into scope. \begin{code} getWiredInDecl name mode = initRnMS emptyRnEnv mod_name new_mode get_wired `thenRn` \ avail -> recordSlurp Nothing necessity avail `thenRn_` -- Force in the home module in case it has instance decls for -- the thing we are interested in. -- -- Mini hack 1: no point for non-tycons/class; and if we -- do this we find PrelNum trying to import PackedString, -- because PrelBase's .hi file mentions PackedString.unpackString -- But PackedString.hi isn't built by that point! -- -- Mini hack 2; GHC is guaranteed not to have -- instance decls, so it's a waste of time to read it -- -- NB: We *must* look at the availName of the slurped avail, -- not the name passed to getWiredInDecl! Why? Because if a data constructor -- or class op is passed to getWiredInDecl we'll pull in the whole data/class -- decl, and recordSlurp will record that fact. But since the data constructor -- isn't a tycon/class we won't force in the home module. And even if the -- type constructor/class comes along later, loadDecl will say that it's already -- been slurped, so getWiredInDecl won't even be called. Pretty obscure bug, this was. let main_name = availName avail main_is_tc = case avail of { AvailTC _ _ -> True; Avail _ -> False } mod = nameModule main_name doc_str = sep [ptext SLIT("need home module for wired in thing"), ppr name] in (if not main_is_tc || mod == gHC__ then returnRn () else loadInterface doc_str mod (ifaceFlavour main_name) `thenRn_` returnRn () ) `thenRn_` returnRn Nothing -- No declaration to process further where necessity = modeToNecessity mode new_mode = case mode of InterfaceMode _ _ -> mode SourceMode -> vanillaInterfaceMode get_wired | is_tycon -- ... a type constructor = get_wired_tycon the_tycon | (isAlgCon the_id) -- ... a wired-in data constructor = get_wired_tycon (dataConTyCon the_id) | otherwise -- ... a wired-in non data-constructor = get_wired_id the_id mod_name = nameModule name maybe_wired_in_tycon = maybeWiredInTyConName name is_tycon = maybeToBool maybe_wired_in_tycon maybe_wired_in_id = maybeWiredInIdName name Just the_tycon = maybe_wired_in_tycon Just the_id = maybe_wired_in_id get_wired_id id = addImplicitOccsRn id_mentions `thenRn_` returnRn (Avail (getName id)) where id_mentions = nameSetToList (namesOfType ty) ty = idType id get_wired_tycon tycon | isSynTyCon tycon = addImplicitOccsRn (nameSetToList mentioned) `thenRn_` returnRn (AvailTC tc_name [tc_name]) where tc_name = getName tycon (tyvars,ty) = getSynTyConDefn tycon mentioned = namesOfType ty `minusNameSet` mkNameSet (map getName tyvars) get_wired_tycon tycon | otherwise -- data or newtype = addImplicitOccsRn (nameSetToList mentioned) `thenRn_` returnRn (AvailTC tycon_name (tycon_name : map getName data_cons)) where tycon_name = getName tycon data_cons = tyConDataCons tycon mentioned = foldr (unionNameSets . namesOfType . idType) emptyNameSet data_cons \end{code} %********************************************************* %* * \subsection{Getting what a module exports} %* * %********************************************************* \begin{code} getInterfaceExports :: Module -> IfaceFlavour -> RnMG (Avails, [(OccName,Fixity)]) getInterfaceExports mod as_source = loadInterface doc_str mod as_source `thenRn` \ (Ifaces _ mod_map _ _ _ _ _ _) -> case lookupFM mod_map mod of Nothing -> -- Not there; it must be that the interface file wasn't found; -- the error will have been reported already. -- (Actually loadInterface should put the empty export env in there -- anyway, but this does no harm.) returnRn ([],[]) Just (_, _, avails, fixities) -> returnRn (avails, fixities) where doc_str = sep [pprModule mod, ptext SLIT("is directly imported")] \end{code} %********************************************************* %* * \subsection{Data type declarations are handled specially} %* * %********************************************************* Data type declarations get special treatment. If we import a data type decl with all its constructors, we end up importing all the types mentioned in the constructors' signatures, and hence {\em their} data type decls, and so on. In effect, we get the transitive closure of data type decls. Worse, this drags in tons on instance decls, and their unfoldings, and so on. If only the type constructor is mentioned, then all this is a waste of time. If any of the data constructors are mentioned then we really have to drag in the whole declaration. So when we import the type constructor for a @data@ or @newtype@ decl, we put it in the "deferred data/newtype decl" pile in Ifaces. Right at the end we slurp these decls, if they havn't already been dragged in by an occurrence of a constructor. \begin{code} getNonWiredDataDecl needed_name version avail@(AvailTC tycon_name _) ty_decl@(TyData new_or_data context tycon tyvars condecls derivings pragmas src_loc) | needed_name == tycon_name && opt_PruneTyDecls && not (nameUnique needed_name `elem` cCallishTyKeys) -- Hack! Don't prune these tycons whose constructors -- the desugarer must be able to see when desugaring -- a CCall. Ugh! = -- Need the type constructor; so put it in the deferred set for now getIfacesRn `thenRn` \ ifaces -> let Ifaces this_mod mod_map decls_fm slurped_names imp_names unslurped_insts deferred_data_decls inst_mods = ifaces new_ifaces = Ifaces this_mod mod_map decls_fm slurped_names imp_names unslurped_insts new_deferred_data_decls inst_mods no_constr_ty_decl = TyData new_or_data [] tycon tyvars [] derivings pragmas src_loc new_deferred_data_decls = addToFM deferred_data_decls tycon_name no_constr_ty_decl -- Nota bene: we nuke both the constructors and the context in the deferred decl. -- If we don't nuke the context then renaming the deferred data decls can give -- new unresolved names (for the classes). This could be handled, but there's -- no point. If the data type is completely abstract then we aren't interested -- its context. in setIfacesRn new_ifaces `thenRn_` returnRn (AvailTC tycon_name [tycon_name], Nothing) | otherwise = -- Need a data constructor, so delete the data decl from the deferred set if it's there getIfacesRn `thenRn` \ ifaces -> let Ifaces this_mod mod_map decls_fm slurped_names imp_names unslurped_insts deferred_data_decls inst_mods = ifaces new_ifaces = Ifaces this_mod mod_map decls_fm slurped_names imp_names unslurped_insts new_deferred_data_decls inst_mods new_deferred_data_decls = delFromFM deferred_data_decls tycon_name in setIfacesRn new_ifaces `thenRn_` returnRn (avail, Just (TyD ty_decl)) \end{code} \begin{code} getDeferredDataDecls :: RnMG [(Name, RdrNameTyDecl)] getDeferredDataDecls = getIfacesRn `thenRn` \ (Ifaces _ _ _ _ _ _ deferred_data_decls _) -> let deferred_list = fmToList deferred_data_decls trace_msg = hang (text "Slurping abstract data/newtype decls for: ") 4 (ppr (map fst deferred_list)) in traceRn trace_msg `thenRn_` returnRn deferred_list \end{code} %********************************************************* %* * \subsection{Instance declarations are handled specially} %* * %********************************************************* \begin{code} getImportedInstDecls :: RnMG [(Module,RdrNameInstDecl)] getImportedInstDecls = -- First load any special-instance modules that aren't aready loaded getSpecialInstModules `thenRn` \ inst_mods -> mapRn load_it inst_mods `thenRn_` -- Now we're ready to grab the instance declarations -- Find the un-gated ones and return them, -- removing them from the bag kept in Ifaces getIfacesRn `thenRn` \ ifaces -> let Ifaces this_mod mod_map decls slurped_names imp_names (insts, tycls_names) deferred_data_decls inst_mods = ifaces -- An instance decl is ungated if all its gates have been slurped select_ungated :: IfaceInst -- A gated inst decl -> ([(Module, RdrNameInstDecl)], [IfaceInst]) -- Accumulator -> ([(Module, RdrNameInstDecl)], -- The ungated ones [IfaceInst]) -- Still gated, but with -- depeleted gates select_ungated (decl,gates) (ungated_decls, gated_decls) | null remaining_gates = (decl : ungated_decls, gated_decls) | otherwise = (ungated_decls, (decl, remaining_gates) : gated_decls) where remaining_gates = filter (not . (`elemNameSet` tycls_names)) gates (un_gated_insts, still_gated_insts) = foldrBag select_ungated ([], []) insts new_ifaces = Ifaces this_mod mod_map decls slurped_names imp_names ((listToBag still_gated_insts), tycls_names) -- NB: don't throw away tycls_names; we may comre across more instance decls deferred_data_decls inst_mods in traceRn (sep [text "getInstDecls:", fsep (map ppr (nameSetToList tycls_names))]) `thenRn_` setIfacesRn new_ifaces `thenRn_` returnRn un_gated_insts where load_it mod = loadInterface (doc_str mod) mod HiFile doc_str mod = sep [pprModule mod, ptext SLIT("is a special-instance module")] getSpecialInstModules :: RnMG [Module] getSpecialInstModules = getIfacesRn `thenRn` \ ifaces -> let Ifaces _ _ _ _ _ _ _ inst_mods = ifaces in returnRn inst_mods \end{code} %********************************************************* %* * \subsection{Keeping track of what we've slurped, and version numbers} %* * %********************************************************* getImportVersions figures out what the "usage information" for this moudule is; that is, what it must record in its interface file as the things it uses. It records: - anything reachable from its body code - any module exported with a "module Foo". Why the latter? Because if Foo changes then this module's export list will change, so we must recompile this module at least as far as making a new interface file --- but in practice that means complete recompilation. What about this? module A( f, g ) where module B( f ) where import B( f ) f = h 3 g = ... h = ... Should we record B.f in A's usages? In fact we don't. Certainly, if anything about B.f changes than anyone who imports A should be recompiled; they'll get an early exit if they don't use B.f. However, even if B.f doesn't change at all, B.h may do so, and this change may not be reflected in f's version number. So there are two things going on when compiling module A: 1. Are A.o and A.hi correct? Then we can bale out early. 2. Should modules that import A be recompiled? For (1) it is slightly harmful to record B.f in A's usages, because a change in B.f's version will provoke full recompilation of A, producing an identical A.o, and A.hi differing only in its usage-version of B.f (which isn't used by any importer). For (2), because of the tricky B.h question above, we ensure that A.hi is touched (even if identical to its previous version) if A's recompilation was triggered by an imported .hi file date change. Given that, there's no need to record B.f in A's usages. On the other hand, if A exports "module B" then we *do* count module B among A's usages, because we must recompile A to ensure that A.hi changes appropriately. \begin{code} getImportVersions :: Module -- Name of this module -> Maybe [IE any] -- Export list for this module -> RnMG (VersionInfo Name) -- Version info for these names getImportVersions this_mod exports = getIfacesRn `thenRn` \ ifaces -> let Ifaces _ mod_map _ _ imp_names _ _ _ = ifaces -- mv_map groups together all the things imported from a particular module. mv_map, mv_map_mod :: FiniteMap Module (WhatsImported Name) mv_map_mod = foldl add_mod emptyFM export_mods -- mv_map_mod records all the modules that have a "module M" -- in this module's export list with an "Everything" mv_map = foldl add_mv mv_map_mod imp_names -- mv_map adds the version numbers of things exported individually mk_version_info (mod, local_versions) = case lookupFM mod_map mod of Just (hif, version, _, _) -> (mod, hif, version, local_versions) in returnRn (map mk_version_info (fmToList mv_map)) where export_mods = case exports of Nothing -> [] Just es -> [mod | IEModuleContents mod <- es, mod /= this_mod] add_mv mv_map v@(name, version) = addToFM_C add_item mv_map mod (Specifically [v]) where mod = nameModule name add_item Everything _ = Everything add_item (Specifically xs) _ = Specifically (v:xs) add_mod mv_map mod = addToFM mv_map mod Everything \end{code} \begin{code} checkSlurped name = getIfacesRn `thenRn` \ (Ifaces _ _ _ slurped_names _ _ _ _) -> returnRn (name `elemNameSet` slurped_names) getSlurpedNames :: RnMG NameSet getSlurpedNames = getIfacesRn `thenRn` \ ifaces -> let Ifaces _ _ _ slurped_names _ _ _ _ = ifaces in returnRn slurped_names recordSlurp maybe_version necessity avail = {- traceRn (hsep [text "Record slurp:", pprAvail avail, -- NB PprForDebug prints export flag, which is too -- strict; it's a knot-tied thing in RnNames case necessity of {Compulsory -> text "comp"; Optional -> text "opt" } ]) `thenRn_` -} getIfacesRn `thenRn` \ ifaces -> let Ifaces this_mod mod_map decls slurped_names imp_names (insts, tycls_names) deferred_data_decls inst_mods = ifaces new_slurped_names = addAvailToNameSet slurped_names avail new_imp_names = case maybe_version of Just version -> (availName avail, version) : imp_names Nothing -> imp_names -- Add to the names that will let in instance declarations; -- but only (a) if it's a type/class -- (b) if it's compulsory (unless the test flag opt_PruneInstDecls is off) new_tycls_names = case avail of AvailTC tc _ | not opt_PruneInstDecls || case necessity of {Optional -> False; Compulsory -> True } -> tycls_names `addOneToNameSet` tc otherwise -> tycls_names new_ifaces = Ifaces this_mod mod_map decls new_slurped_names new_imp_names (insts, new_tycls_names) deferred_data_decls inst_mods in setIfacesRn new_ifaces \end{code} %********************************************************* %* * \subsection{Getting binders out of a declaration} %* * %********************************************************* @getDeclBinders@ returns the names for a @RdrNameHsDecl@. It's used for both source code (from @availsFromDecl@) and interface files (from @loadDecl@). It doesn't deal with source-code specific things: ValD, DefD. They are handled by the sourc-code specific stuff in RnNames. \begin{code} getDeclBinders :: (RdrName -> SrcLoc -> RnMG Name) -- New-name function -> RdrNameHsDecl -> RnMG AvailInfo getDeclBinders new_name (TyD (TyData _ _ tycon _ condecls _ _ src_loc)) = new_name tycon src_loc `thenRn` \ tycon_name -> getConFieldNames new_name condecls `thenRn` \ sub_names -> returnRn (AvailTC tycon_name (tycon_name : nub sub_names)) -- The "nub" is because getConFieldNames can legitimately return duplicates, -- when a record declaration has the same field in multiple constructors getDeclBinders new_name (TyD (TySynonym tycon _ _ src_loc)) = new_name tycon src_loc `thenRn` \ tycon_name -> returnRn (AvailTC tycon_name [tycon_name]) getDeclBinders new_name (ClD (ClassDecl _ cname _ sigs _ _ tname dname src_loc)) = new_name cname src_loc `thenRn` \ class_name -> new_name dname src_loc `thenRn` \ datacon_name -> new_name tname src_loc `thenRn` \ tycon_name -> -- Record the names for the class ops mapRn (getClassOpNames new_name) sigs `thenRn` \ sub_names -> returnRn (AvailTC class_name (class_name : datacon_name : tycon_name : sub_names)) getDeclBinders new_name (SigD (IfaceSig var ty prags src_loc)) = new_name var src_loc `thenRn` \ var_name -> returnRn (Avail var_name) getDeclBinders new_name (DefD _) = returnRn NotAvailable getDeclBinders new_name (InstD _) = returnRn NotAvailable ---------------- getConFieldNames new_name (ConDecl con _ (RecCon fielddecls) src_loc : rest) = mapRn (\n -> new_name n src_loc) (con:fields) `thenRn` \ cfs -> getConFieldNames new_name rest `thenRn` \ ns -> returnRn (cfs ++ ns) where fields = concat (map fst fielddecls) getConFieldNames new_name (ConDecl con _ _ src_loc : rest) = new_name con src_loc `thenRn` \ n -> getConFieldNames new_name rest `thenRn` \ ns -> returnRn (n:ns) getConFieldNames new_name [] = returnRn [] getClassOpNames new_name (ClassOpSig op _ _ src_loc) = new_name op src_loc \end{code} %********************************************************* %* * \subsection{Reading an interface file} %* * %********************************************************* \begin{code} findAndReadIface :: SDoc -> Module -> IfaceFlavour -> RnMG (Maybe ParsedIface) -- Nothing <=> file not found, or unreadable, or illegible -- Just x <=> successfully found and parsed findAndReadIface doc_str mod_name as_source = traceRn trace_msg `thenRn_` getSearchPathRn `thenRn` \ dirs -> try dirs dirs where trace_msg = sep [hsep [ptext SLIT("Reading"), case as_source of { HiBootFile -> ptext SLIT("[boot]"); other -> empty}, ptext SLIT("interface for"), ptext mod_name <> semi], nest 4 (ptext SLIT("reason:") <+> doc_str)] -- For import {-# SOURCE #-} Foo, "as_source" will be True -- and we read Foo.hi-boot, not Foo.hi. This is used to break -- loops among modules. mod_suffix hi = case as_source of HiBootFile -> ".hi-boot" -- Ignore `ways' for boot files. HiFile -> hi try all_dirs [] = traceRn (ptext SLIT("...failed")) `thenRn_` returnRn Nothing try all_dirs ((dir,hisuf):dirs) = readIface file_path `thenRn` \ read_result -> case read_result of Nothing -> try all_dirs dirs Just iface -> traceRn (ptext SLIT("...done")) `thenRn_` returnRn (Just iface) where file_path = dir ++ '/' : moduleString mod_name ++ (mod_suffix hisuf) \end{code} @readIface@ trys just one file. \begin{code} readIface :: String -> RnMG (Maybe ParsedIface) -- Nothing <=> file not found, or unreadable, or illegible -- Just x <=> successfully found and parsed readIface file_path = ioToRnMG (hGetStringBuffer file_path) `thenRn` \ read_result -> --traceRn (hcat[ptext SLIT("Opening...."), text file_path]) `thenRn_` case read_result of Right contents -> case parseIface contents (mkSrcLoc (mkFastString file_path) 1) of Failed err -> failWithRn Nothing err Succeeded (PIface iface) -> returnRn (Just iface) Left err -> if isDoesNotExistError err then returnRn Nothing else failWithRn Nothing (cannaeReadFile file_path err) \end{code} mkSearchPath takes a string consisting of a colon-separated list of directories and corresponding suffixes, and turns it into a list of (directory, suffix) pairs. For example: \begin{verbatim} mkSearchPath "foo%.hi:.%.p_hi:baz%.mc_hi" = [("foo",".hi"),( ".", ".p_hi"), ("baz",".mc_hi")] \begin{verbatim} \begin{code} mkSearchPath :: Maybe String -> SearchPath mkSearchPath Nothing = [(".",".hi")] mkSearchPath (Just s) = go s where go "" = [] go s = case span (/= '%') s of (dir,'%':rs) -> case span (/= ':') rs of (hisuf,_:rest) -> (dir,hisuf):go rest (hisuf,[]) -> [(dir,hisuf)] \end{code} %********************************************************* %* * \subsection{Errors} %* * %********************************************************* \begin{code} noIfaceErr filename = hcat [ptext SLIT("Could not find valid interface file "), quotes (pprModule filename)] cannaeReadFile file err = hcat [ptext SLIT("Failed in reading file: "), text file, ptext SLIT("; error="), text (show err)] getDeclErr name loc = sep [ptext SLIT("Failed to find interface decl for"), quotes (ppr name), ptext SLIT("needed at"), ppr loc] getDeclWarn name loc = sep [ptext SLIT("Warning: failed to find (optional) interface decl for"), quotes (ppr name), ptext SLIT("desired at"), ppr loc] \end{code}