X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnIfaces.lhs;h=a56da3b240449171dee2e7471161d1c2596c8657;hb=bac531aaf56c7558eda70531e9565f753d21f848;hp=2b3d04cc24b33120e3242c49e0514a8b76113cff;hpb=bfce9573fc285187e0dc56f1bad4a02d5b00d38c;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnIfaces.lhs b/ghc/compiler/rename/RnIfaces.lhs index 2b3d04c..a56da3b 100644 --- a/ghc/compiler/rename/RnIfaces.lhs +++ b/ghc/compiler/rename/RnIfaces.lhs @@ -1,1059 +1,919 @@ % -% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996 +% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % \section[RnIfaces]{Cacheing and Renaming of Interfaces} \begin{code} -module RnIfaces ( +module RnIfaces + ( getInterfaceExports, - getImportedInstDecls, - getSpecialInstModules, getDeferredDataDecls, - importDecl, recordSlurp, - getImportVersions, getSlurpedNames, getRnStats, + recordLocalSlurps, + mkImportInfo, - checkUpToDate, + slurpImpDecls, closeDecls, - getDeclBinders, - mkSearchPath - ) where + RecompileRequired, outOfDate, upToDate, recompileRequired + ) +where #include "HsVersions.h" -import CmdLineOpts ( opt_PruneTyDecls, opt_PruneInstDecls, - opt_D_show_rn_imports, opt_IgnoreIfacePragmas +import CmdLineOpts ( DynFlags, opt_NoPruneDecls, opt_NoPruneTyDecls, opt_IgnoreIfacePragmas ) +import HscTypes +import HsSyn ( HsDecl(..), Sig(..), TyClDecl(..), ConDecl(..), ConDetails(..), + InstDecl(..), HsType(..), hsTyVarNames, getBangType ) -import HsSyn ( HsDecl(..), TyDecl(..), ClassDecl(..), InstDecl(..), IfaceSig(..), - HsType(..), ConDecl(..), IE(..), ConDetails(..), Sig(..), - hsDeclName +import HsImpExp ( ImportDecl(..) ) +import RdrHsSyn ( RdrNameHsDecl, RdrNameTyClDecl, RdrNameInstDecl ) +import RnHsSyn ( RenamedHsDecl, extractHsTyNames, extractHsCtxtTyNames, tyClDeclFVs ) +import RnHiFiles ( tryLoadInterface, loadHomeInterface, loadInterface, + loadOrphanModules ) -import BasicTypes ( Version, NewOrData(..), IfaceFlavour(..) ) -import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameTyDecl, - RdrName(..), rdrNameOcc - ) -import RnEnv ( newImportedGlobalName, addImplicitOccsRn, - ifaceFlavour, availName, availNames, addAvailToNameSet - ) -import RnSource ( rnHsSigType ) +import RnSource ( rnTyClDecl, rnDecl ) +import RnEnv import RnMonad -import RnHsSyn ( RenamedHsDecl ) -import ParseIface ( parseIface, IfaceStuff(..) ) - -import FiniteMap ( FiniteMap, sizeFM, emptyFM, delFromFM, - lookupFM, addToFM, addToFM_C, addListToFM, - fmToList - ) -import Name ( Name {-instance NamedThing-}, Provenance, OccName(..), - nameModule, 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 Id ( idType ) import Type ( namesOfType ) -import TyVar ( GenTyVar ) -import SrcLoc ( mkSrcLoc, SrcLoc ) -import PrelMods ( pREL_GHC ) -import PrelInfo ( cCallishTyKeys ) -import Bag -import Maybes ( MaybeErr(..), maybeToBool ) -import ListSetOps ( unionLists ) -import Outputable -import Unique ( Unique ) -import StringBuffer ( StringBuffer, hGetStringBuffer ) -import FastString ( mkFastString ) +import TyCon ( isSynTyCon, getSynTyConDefn ) +import Name ( Name {-instance NamedThing-}, nameOccName, + nameModule, isLocallyDefined, nameUnique, + NamedThing(..), + elemNameEnv + ) +import Module ( Module, ModuleEnv, + moduleName, isModuleInThisPackage, + ModuleName, WhereFrom(..), + emptyModuleEnv, lookupModuleEnvByName, + extendModuleEnv_C, lookupWithDefaultModuleEnv + ) +import NameSet +import PrelInfo ( wiredInThingEnv, fractionalClassKeys ) +import TysWiredIn ( doubleTyCon ) +import Maybes ( orElse ) +import FiniteMap import Outputable +import Bag -import IO ( isDoesNotExistError ) -import List ( nub ) +import List ( nub ) \end{code} - %********************************************************* %* * -\subsection{Statistics} +\subsection{Getting what a module exports} %* * %********************************************************* +@getInterfaceExports@ is called only for directly-imported modules. + \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] +getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, [(ModuleName,Avails)]) +getInterfaceExports mod_name from + = getHomeIfaceTableRn `thenRn` \ hit -> + case lookupModuleEnvByName hit mod_name of { + Just mi -> returnRn (mi_module mi, mi_exports mi) ; + Nothing -> + + loadInterface doc_str mod_name from `thenRn` \ ifaces -> + case lookupModuleEnvByName (iPIT ifaces) mod_name of + Just mi -> returnRn (mi_module mi, mi_exports mi) ; + -- loadInterface always puts something in the map + -- even if it's a fake + Nothing -> pprPanic "getInterfaceExports" (ppr mod_name) + } + where + doc_str = sep [ppr mod_name, ptext SLIT("is directly imported")] +\end{code} -\end{code} %********************************************************* %* * -\subsection{Loading a new interface file} +\subsection{Instance declarations are handled specially} %* * %********************************************************* \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 -> +getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)] +getImportedInstDecls gates + = -- First, load any orphan-instance modules that aren't aready loaded + -- Orphan-instance modules are recorded in the module dependecnies + getIfacesRn `thenRn` \ ifaces -> 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 + orphan_mods = + [mod | (mod, (True, _, False)) <- fmToList (iImpModInfo ifaces)] in - setIfacesRn new_ifaces `thenRn_` - returnRn new_ifaces - }} - -as_good_as HiFile any = True -as_good_as any HiBootFile = True -as_good_as _ _ = False + loadOrphanModules orphan_mods `thenRn_` - -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 + -- 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 + (decls, new_insts) = selectGated gates (iInsts ifaces) 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} -%* * -%******************************************************** + setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_` -\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 + traceRn (sep [text "getImportedInstDecls:", + nest 4 (fsep (map ppr gate_list)), + text "Slurped" <+> int (length decls) <+> text "instance declarations", + nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_` + returnRn decls where - -- Only look in current directory, with suffix .hi - doc_str = sep [ptext SLIT("need usage info from"), pprModule mod_name] + gate_list = nameSetToList gates -checkModUsage [] = returnRn True -- Yes! Everything is up to date! +ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _)) + = case inst_ty of + HsForAllTy _ _ tau -> ppr tau + other -> ppr inst_ty -checkModUsage ((mod, hif, old_mod_vers, whats_imported) : rest) - = loadInterface doc_str mod hif `thenRn` \ ifaces -> +getImportedRules :: RnMG [(Module,RdrNameHsDecl)] +getImportedRules + | opt_IgnoreIfacePragmas = returnRn [] + | otherwise + = getIfacesRn `thenRn` \ ifaces -> let - Ifaces _ mod_map decls _ _ _ _ _ = ifaces - maybe_new_mod_vers = lookupFM mod_map mod - Just (_, new_mod_vers, _, _) = maybe_new_mod_vers + gates = iSlurp ifaces -- Anything at all that's been slurped + rules = iRules ifaces + (decls, new_rules) = selectGated gates rules 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 + if null decls then + returnRn [] else - traceRn (sep [ptext SLIT("Module version has changed:"), pprModule mod]) `thenRn_` + setIfacesRn (ifaces { iRules = new_rules }) `thenRn_` + traceRn (sep [text "getImportedRules:", + text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_` + returnRn decls - -- Module version changed, so check entities inside +selectGated gates decl_bag + -- Select only those decls whose gates are *all* in 'gates' +#ifdef DEBUG + | opt_NoPruneDecls -- Just to try the effect of not gating at all + = (foldrBag (\ (_,d) ds -> d:ds) [] decl_bag, emptyBag) -- Grab them all - -- 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 - } + | otherwise +#endif + = foldrBag select ([], emptyBag) decl_bag 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 + select (reqd, decl) (yes, no) + | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no) + | otherwise = (yes, (reqd,decl) `consBag` no) \end{code} %********************************************************* %* * -\subsection{Getting in a declaration} +\subsection{Keeping track of what we've slurped, and version numbers} %* * %********************************************************* -\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 - addWarnRn (importDeclWarn mod name loc) `thenRn_` --- pprTrace "importDecl wierdness:" (ppr name) $ - returnRn Nothing -- the renamed module's own interface file - -- - else - getNonWiredInDecl name loc mode -\end{code} +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: -\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 +\begin{itemize} +\item (a) anything reachable from its body code +\item (b) any module exported with a @module Foo@ +\item (c) anything reachable from an exported item +\end{itemize} - is_data_or_newtype (TyData _ _ _ _ _ _ _ _) = True - is_data_or_newtype other = False +Why (b)? 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. -\end{code} +Why (c)? Consider this: +\begin{verbatim} + module A( f, g ) where | module B( f ) where + import B( f ) | f = h 3 + g = ... | h = ... +\end{verbatim} + +Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in +@A@'s usages? Our idea is that we aren't going to touch A.hi if it is +*identical* to what it was before. If anything about @B.f@ changes +than anyone who imports @A@ should be recompiled in case they use +@B.f@ (they'll get an early exit if they don't). So, if anything +about @B.f@ changes we'd better make sure that something in A.hi +changes, and the convenient way to do that is to record the version +number @B.f@ in A.hi in the usage list. If B.f changes that'll force a +complete recompiation of A, which is overkill but it's the only way to +write a new, slightly different, A.hi. + +But the example is tricker. 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. But with -O, a module that imports A must be recompiled if +@B.h@ changes! So A must record a dependency on @B.h@. So we treat +the occurrence of @B.f@ in the export list *just as if* it were in the +code of A, and thereby haul in all the stuff reachable from it. + +[NB: If B was compiled with -O, but A isn't, we should really *still* +haul in all the unfoldings for B, in case the module that imports A *is* +compiled with -O. I think this is the case.] + +Even if B is used at all we get a usage line for B + import B :: ... ; +in A.hi, to record the fact that A does import B. This is used to decide +to look to look for B.hi rather than B.hi-boot when compiling a module that +imports A. This line says that A imports B, but uses nothing in it. +So we'll get an early bale-out when compiling A if B's version changes. -@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, +\begin{code} +mkImportInfo :: ModuleName -- Name of this module + -> [ImportDecl n] -- The import decls + -> RnMG [ImportVersion Name] - * 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. +mkImportInfo this_mod imports + = getIfacesRn `thenRn` \ ifaces -> + getHomeIfaceTableRn `thenRn` \ hit -> + let + import_all_mods :: [ModuleName] + -- Modules where we imported all the names + -- (apart from hiding some, perhaps) + import_all_mods = nub [ m | ImportDecl m _ _ _ imp_list _ <- imports, + import_all imp_list ] - * similarly for synonum type constructor + import_all (Just (False, _)) = False -- Imports are specified explicitly + import_all other = True -- Everything is imported - * if the wired-in name is another wired-in Id, it marks as "occurrences" - the free vars of the Id's type. + mod_map = iImpModInfo ifaces + imp_names = iVSlurp ifaces + pit = iPIT ifaces - * it loads the interface file for the wired-in thing for the - sole purpose of making sure that its instance declarations are available + -- mv_map groups together all the things imported from a particular module. + mv_map :: ModuleEnv [Name] + mv_map = foldr add_mv emptyModuleEnv imp_names -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_` + add_mv name mv_map = addItem mv_map (nameModule name) name - -- 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 + -- Build the result list by adding info for each module. + -- For (a) a library module, we don't record it at all unless it contains orphans + -- (We must never lose track of orphans.) + -- + -- (b) a source-imported module, don't record the dependency at all + -- + -- (b) may seem a bit strange. The idea is that the usages in a .hi file records + -- *all* the module's dependencies other than the loop-breakers. We use + -- this info in findAndReadInterface to decide whether to look for a .hi file or + -- a .hi-boot file. -- - -- 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] + -- This means we won't track version changes, or orphans, from .hi-boot files. + -- The former is potentially rather bad news. It could be fixed by recording + -- whether something is a boot file along with the usage info for it, but + -- I can't be bothered just now. + + mk_imp_info mod_name (has_orphans, is_boot, opened) so_far + | mod_name == this_mod -- Check if M appears in the set of modules 'below' M + -- This seems like a convenient place to check + = WARN( not is_boot, ptext SLIT("Wierd:") <+> ppr this_mod <+> + ptext SLIT("imports itself (perhaps indirectly)") ) + so_far + + | not opened -- We didn't even open the interface + = -- This happens when a module, Foo, that we explicitly imported has + -- 'import Baz' in its interface file, recording that Baz is below + -- Foo in the module dependency hierarchy. We want to propagate this + -- information. The Nothing says that we didn't even open the interface + -- file but we must still propagate the dependency info. + -- The module in question must be a local module (in the same package) + go_for_it NothingAtAll + + + | is_lib_module && not has_orphans + = so_far + + | is_lib_module -- Record the module version only + = go_for_it (Everything module_vers) + + | otherwise + = go_for_it whats_imported + + where + go_for_it exports = (mod_name, has_orphans, is_boot, exports) : so_far + mod_iface = lookupTableByModName hit pit mod_name `orElse` panic "mkImportInfo" + mod = mi_module mod_iface + is_lib_module = not (isModuleInThisPackage mod) + version_info = mi_version mod_iface + version_env = vers_decls version_info + module_vers = vers_module version_info + + whats_imported = Specifically module_vers + export_vers import_items + (vers_rules version_info) + + import_items = [(n,v) | n <- lookupWithDefaultModuleEnv mv_map [] mod, + let v = lookupNameEnv version_env n `orElse` + pprPanic "mk_whats_imported" (ppr n) + ] + export_vers | moduleName mod `elem` import_all_mods + = Just (vers_exports version_info) + | otherwise + = Nothing + + import_info = foldFM mk_imp_info [] mod_map in - (if not main_is_tc || mod == pREL_GHC then - returnRn () - else - loadInterface doc_str mod (ifaceFlavour main_name) `thenRn_` - returnRn () - ) `thenRn_` + traceRn (text "Modules in Ifaces: " <+> fsep (map ppr (keysFM mod_map))) `thenRn_` + returnRn import_info - 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 +addItem :: ModuleEnv [a] -> Module -> a -> ModuleEnv [a] +addItem fm mod x = extendModuleEnv_C add_item fm mod [x] + where + add_item xs _ = x:xs +\end{code} - | (isAlgCon the_id) -- ... a wired-in data constructor - = get_wired_tycon (dataConTyCon the_id) +%********************************************************* +%* * +\subsection{Slurping declarations} +%* * +%********************************************************* - | otherwise -- ... a wired-in non data-constructor - = get_wired_id the_id +\begin{code} +------------------------------------------------------- +slurpImpDecls source_fvs + = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_` - 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 + -- The current slurped-set records all local things + getSlurped `thenRn` \ source_binders -> + slurpSourceRefs source_binders source_fvs `thenRn` \ (decls, needed) -> + -- Then get everything else + closeDecls decls needed `thenRn` \ decls1 -> -get_wired_id id - = addImplicitOccsRn id_mentions `thenRn_` - returnRn (Avail (getName id)) - where - id_mentions = nameSetToList (namesOfType ty) - ty = idType id + -- Finally, get any deferred data type decls + slurpDeferredDecls decls1 `thenRn` \ final_decls -> -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} + returnRn final_decls - -%********************************************************* -%* * -\subsection{Getting what a module exports} -%* * -%********************************************************* +------------------------------------------------------- +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 -\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) +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 - doc_str = sep [pprModule mod, ptext SLIT("is directly imported")] + -- 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_` + foldlRn 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) wanted_name + = importDecl wanted_name `thenRn` \ import_result -> + case import_result of + AlreadySlurped -> returnRn (decls, fvs, gates) + WiredIn -> returnRn (decls, fvs, gates `plusFV` getWiredInGates wanted_name) + Deferred -> returnRn (decls, fvs, gates `addOneFV` wanted_name) -- It's a type constructor + + HereItIs decl -> rnIfaceTyClDecl decl `thenRn` \ (new_decl, fvs1) -> + returnRn (TyClD new_decl : decls, + fvs1 `plusFV` fvs, + gates `plusFV` getGates source_fvs new_decl) + +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} -%********************************************************* -%* * -\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. +\begin{code} +------------------------------------------------------- +-- 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 -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. + | 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 + + +------------------------------------------------------- +-- 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` \ import_result -> + case import_result of + -- Found a declaration... rename it + HereItIs decl -> rnIfaceTyClDecl decl `thenRn` \ (new_decl, fvs1) -> + returnRn (TyClD new_decl:decls, fvs1 `plusFV` fvs) + + -- No declaration... (wired in thing, or deferred, or already slurped) + other -> returnRn (decls, fvs) + + +------------------------------------------------------- +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) +rnIfaceTyClDecl (mod, decl) = initIfaceRnMS mod (rnTyClDecl decl) `thenRn` \ decl' -> + returnRn (decl', tyClDeclFVs decl') +\end{code} -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 - -- don't prune newtypes, as the code generator may - -- want to peer inside a newtype type constructor - -- (ClosureInfo.fun_result_ty is the culprit.) - && not (new_or_data == NewType) - && 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. +getSlurped + = getIfacesRn `thenRn` \ ifaces -> + returnRn (iSlurp ifaces) + +recordSlurp ifaces@(Ifaces { iSlurp = slurped_names, iVSlurp = imp_names }) + avail + = let + new_slurped_names = addAvailToNameSet slurped_names avail + new_imp_names = availName avail : imp_names in - setIfacesRn new_ifaces `thenRn_` - returnRn (AvailTC tycon_name [tycon_name], Nothing) + ifaces { iSlurp = new_slurped_names, iVSlurp = new_imp_names } - | otherwise - = -- Need a data constructor, so delete the data decl from the deferred set if it's there - getIfacesRn `thenRn` \ ifaces -> +recordLocalSlurps local_avails + = 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 + new_slurped_names = foldl addAvailToNameSet (iSlurp ifaces) local_avails in - setIfacesRn new_ifaces `thenRn_` - returnRn (avail, Just (TyD ty_decl)) + setIfacesRn (ifaces { iSlurp = new_slurped_names }) \end{code} + + +%********************************************************* +%* * +\subsection{Deferred declarations} +%* * +%********************************************************* + +The idea of deferred declarations is this. Suppose we have a function + f :: T -> Int + data T = T1 A | T2 B + data A = A1 X | A2 Y + data B = B1 P | B2 Q +Then we don't want to load T and all its constructors, and all +the types those constructors refer to, and all the types *those* +constructors refer to, and so on. That might mean loading many more +interface files than is really necessary. So we 'defer' loading T. + +But f might be strict, and the calling convention for evaluating +values of type T depends on how many constructors T has, so +we do need to load T, but not the full details of the type T. +So we load the full decl for T, but only skeleton decls for A and B: + f :: T -> Int + data T = {- 2 constructors -} + +Whether all this is worth it is moot. + \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 +slurpDeferredDecls :: [RenamedHsDecl] -> RnMG [RenamedHsDecl] +slurpDeferredDecls decls = returnRn decls + +{- OMIT FOR NOW +slurpDeferredDecls :: [RenamedHsDecl] -> RnMG [RenamedHsDecl] +slurpDeferredDecls decls + = getDeferredDecls `thenRn` \ def_decls -> + rnIfaceDecls decls emptyFVs (map stripDecl def_decls) `thenRn` \ (decls1, fvs) -> + ASSERT( isEmptyFVs fvs ) + returnRn decls1 + +stripDecl (mod, TyClD (TyData dt _ tc tvs _ nconstrs _ loc name1 name2)) + = (mod, TyClD (TyData dt [] tc tvs [] nconstrs Nothing loc + name1 name2)) + -- Nuke the context and constructors + -- But retain the *number* of constructors! + -- Also the tvs will have kinds on them. +-} \end{code} %********************************************************* -%* * -\subsection{Instance declarations are handled specially} -%* * +%* * +\subsection{Extracting the `gates'} +%* * %********************************************************* +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. + +@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} -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_` +getGates source_fvs (IfaceSig _ ty _ _) + = extractHsTyNames ty + +getGates source_fvs (ClassDecl ctxt cls tvs _ sigs _ _ _ ) + = (delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) sigs) + (hsTyVarNames 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 (TySynonym tycon tvs ty _) + = delListFromNameSet (extractHsTyNames ty) + (hsTyVarNames tvs) + -- A type synonym type constructor isn't a "gate" for instance decls + +getGates source_fvs (TyData _ ctxt tycon tvs cons _ _ _ _ _) + = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) cons) + (hsTyVarNames 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) + (hsTyVarNames 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 - -- 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 + 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] - -- An instance decl is ungated if all its gates have been slurped - select_ungated :: IfaceInst -- A gated inst decl + get_field (fs,t) | any (`elemNameSet` source_fvs) fs = get_bang t + | otherwise = emptyFVs + + get_bang bty = extractHsTyNames (getBangType bty) +\end{code} - -> ([(Module, RdrNameInstDecl)], [IfaceInst]) -- Accumulator +@getWiredInGates@ is just like @getGates@, but it sees a wired-in @Name@ +rather than a declaration. - -> ([(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) +\begin{code} +getWiredInGates :: Name -> FreeVars +getWiredInGates name -- No classes are wired in + = case lookupNameEnv wiredInThingEnv name of + Just (AnId the_id) -> getWiredInGates_s (namesOfType (idType the_id)) + + Just (ATyCon tc) + | isSynTyCon tc + -> getWiredInGates_s (delListFromNameSet (namesOfType ty) (map getName tyvars)) where - remaining_gates = filter (not . (`elemNameSet` tycls_names)) gates + (tyvars,ty) = getSynTyConDefn tc - (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")] + other -> unitFV name +getWiredInGates_s names = foldr (plusFV . getWiredInGates) emptyFVs (nameSetToList names) +\end{code} -getSpecialInstModules :: RnMG [Module] -getSpecialInstModules - = getIfacesRn `thenRn` \ ifaces -> - let - Ifaces _ _ _ _ _ _ _ inst_mods = ifaces - in - returnRn inst_mods +\begin{code} +getInstDeclGates (InstD (InstDecl inst_ty _ _ _ _)) = extractHsTyNames inst_ty +getInstDeclGates other = emptyFVs \end{code} %********************************************************* %* * -\subsection{Keeping track of what we've slurped, and version numbers} +\subsection{Getting in a declaration} %* * %********************************************************* -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 +importDecl :: Name -> RnMG ImportDeclResult + +data ImportDeclResult + = AlreadySlurped + | WiredIn + | Deferred + | HereItIs (Module, RdrNameTyClDecl) + +importDecl name + = -- Check if it was loaded before beginning this module + checkAlreadyAvailable name `thenRn` \ done -> + if done then + returnRn AlreadySlurped + else - -- mv_map groups together all the things imported from a particular module. - mv_map, mv_map_mod :: FiniteMap Module (WhatsImported Name) + -- Check if we slurped it in while compiling this module + getIfacesRn `thenRn` \ ifaces -> + if name `elemNameSet` iSlurp ifaces then + returnRn AlreadySlurped + else - 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" + -- Don't slurp in decls from this module's own interface file + -- (Indeed, this shouldn't happen.) + if isLocallyDefined name then + addWarnRn (importDeclWarn name) `thenRn_` + returnRn AlreadySlurped + else - mv_map = foldl add_mv mv_map_mod imp_names - -- mv_map adds the version numbers of things exported individually + -- When we find a wired-in name we must load its home + -- module so that we find any instance decls lurking therein + if name `elemNameEnv` wiredInThingEnv then + loadHomeInterface doc name `thenRn_` + returnRn WiredIn - 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)) + else getNonWiredInDecl name 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]) + doc = ptext SLIT("need home module for wired in thing") <+> ppr name + +getNonWiredInDecl :: Name -> RnMG ImportDeclResult +getNonWiredInDecl needed_name + = traceRn doc_str `thenRn_` + loadHomeInterface doc_str needed_name `thenRn` \ ifaces -> + case lookupNameEnv (iDecls ifaces) needed_name of + +{- OMIT DEFERRED STUFF FOR NOW, TILL GHCI WORKS + Just (version, avail, is_tycon_name, decl@(_, TyClD (TyData DataType _ _ _ _ ncons _ _ _ _))) + -- This case deals with deferred import of algebraic data types + + | not opt_NoPruneTyDecls + + && (opt_IgnoreIfacePragmas || ncons > 1) + -- We only defer if imported interface pragmas are ingored + -- or if it's not a product type. + -- Sole reason: The wrapper for a strict function may need to look + -- inside its arg, and hence need to see its arg type's constructors. + + && not (getUnique tycon_name `elem` cCallishTyKeys) + -- Never defer ccall types; we have to unbox them, + -- and importing them does no harm + + + -> -- OK, so we're importing a deferrable data type + if needed_name == tycon_name + -- The needed_name is the TyCon of a data type decl + -- Record that it's slurped, put it in the deferred set + -- and don't return a declaration at all + setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces + `addOneToNameSet` tycon_name}) + version (AvailTC needed_name [needed_name])) `thenRn_` + returnRn Deferred + + else + -- The needed name is a constructor of a data type decl, + -- getting a constructor, so remove the TyCon from the deferred set + -- (if it's there) and return the full declaration + setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces + `delFromNameSet` tycon_name}) + version avail) `thenRn_` + returnRn (HereItIs decl) where - mod = nameModule name - - add_item Everything _ = Everything - add_item (Specifically xs) _ = Specifically (v:xs) + tycon_name = availName avail +-} - add_mod mv_map mod = addToFM mv_map mod Everything -\end{code} + Just (avail,_,decl) + -> setIfacesRn (recordSlurp ifaces avail) `thenRn_` + returnRn (HereItIs decl) -\begin{code} -checkSlurped name - = getIfacesRn `thenRn` \ (Ifaces _ _ _ slurped_names _ _ _ _) -> - returnRn (name `elemNameSet` slurped_names) + Nothing + -> addErrRn (getDeclErr needed_name) `thenRn_` + returnRn AlreadySlurped + where + doc_str = ptext SLIT("need decl for") <+> ppr needed_name -getSlurpedNames :: RnMG NameSet -getSlurpedNames - = getIfacesRn `thenRn` \ ifaces -> +{- OMIT FOR NOW +getDeferredDecls :: RnMG [(Module, RdrNameHsDecl)] +getDeferredDecls + = getIfacesRn `thenRn` \ ifaces -> let - Ifaces _ _ _ slurped_names _ _ _ _ = ifaces + decls_map = iDecls ifaces + deferred_names = nameSetToList (iDeferred ifaces) + get_abstract_decl n = case lookupNameEnv decls_map n of + Just (_, _, _, decl) -> decl 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 + traceRn (sep [text "getDeferredDecls", nest 4 (fsep (map ppr deferred_names))]) `thenRn_` + returnRn (map get_abstract_decl deferred_names) +-} +\end{code} - new_slurped_names = addAvailToNameSet slurped_names avail +@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, +\begin{itemize} +\item 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. - 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} +\item similarly for synonum type constructor +\item if the wired-in name is another wired-in Id, it marks as ``occurrences'' + the free vars of the Id's type. -%********************************************************* +\item it loads the interface file for the wired-in thing for the + sole purpose of making sure that its instance declarations are available +\end{itemize} +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. + + +%******************************************************** %* * -\subsection{Getting binders out of a declaration} +\subsection{Checking usage information} %* * -%********************************************************* +%******************************************************** -@getDeclBinders@ returns the names for a @RdrNameHsDecl@. -It's used for both source code (from @availsFromDecl@) and interface files -(from @loadDecl@). +@recompileRequired@ is called from the HscMain. It checks whether +a recompilation is required. It needs access to the persistent state, +finder, etc, because it may have to load lots of interface files to +check their versions. -It doesn't deal with source-code specific things: ValD, DefD. They -are handled by the sourc-code specific stuff in RnNames. +\begin{code} +type RecompileRequired = Bool +upToDate = False -- Recompile not required +outOfDate = True -- Recompile required + +recompileRequired :: Module + -> Bool -- Source unchanged + -> Maybe ModIface -- Old interface, if any + -> RnMG RecompileRequired +recompileRequired mod source_unchanged maybe_iface + = traceRn (text "Considering whether compilation is required for" <+> ppr mod <> colon) `thenRn_` + + -- CHECK WHETHER THE SOURCE HAS CHANGED + if not source_unchanged then + traceRn (nest 4 (text "Source file changed or recompilation check turned off")) `thenRn_` + returnRn outOfDate + else + -- CHECK WHETHER WE HAVE AN OLD IFACE + case maybe_iface of + Nothing -> traceRn (nest 4 (ptext SLIT("No old interface file"))) `thenRn_` + returnRn outOfDate ; + + Just iface -> -- Source code unchanged and no errors yet... carry on + checkList [checkModUsage u | u <- mi_usages iface] + +checkList :: [RnMG RecompileRequired] -> RnMG RecompileRequired +checkList [] = returnRn upToDate +checkList (check:checks) = check `thenRn` \ recompile -> + if recompile then + returnRn outOfDate + else + checkList checks +\end{code} + \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) +checkModUsage :: ImportVersion Name -> RnMG RecompileRequired +-- Given the usage information extracted from the old +-- M.hi file for the module being compiled, figure out +-- whether M needs to be recompiled. + +checkModUsage (mod_name, _, _, NothingAtAll) + -- If CurrentModule.hi contains + -- import Foo :: ; + -- then that simply records that Foo lies below CurrentModule in the + -- hierarchy, but CurrentModule doesn't depend in any way on Foo. + -- In this case we don't even want to open Foo's interface. + = up_to_date (ptext SLIT("Nothing used from:") <+> ppr mod_name) + +checkModUsage (mod_name, _, _, whats_imported) + = tryLoadInterface doc_str mod_name ImportBySystem `thenRn` \ (ifaces, maybe_err) -> + case maybe_err of { + Just err -> out_of_date (sep [ptext SLIT("Can't find version number for module"), + ppr mod_name]) ; + -- Couldn't find or parse a module mentioned in the + -- old interface file. Don't complain -- it might just be that + -- the current module doesn't need that import and it's been deleted + + Nothing -> + + getHomeIfaceTableRn `thenRn` \ hit -> + let + mod_details = lookupTableByModName hit (iPIT ifaces) mod_name + `orElse` panic "checkModUsage" + new_vers = mi_version mod_details + new_decl_vers = vers_decls new_vers + in + case whats_imported of { -- NothingAtAll dealt with earlier -getConFieldNames new_name (ConDecl con _ _ src_loc : rest) - = new_name con src_loc `thenRn` \ n -> - getConFieldNames new_name rest `thenRn` \ ns -> - returnRn (n:ns) + Everything old_mod_vers -> checkModuleVersion old_mod_vers new_vers `thenRn` \ recompile -> + if recompile then + out_of_date (ptext SLIT("...and I needed the whole module")) + else + returnRn upToDate ; -getConFieldNames new_name [] = returnRn [] + Specifically old_mod_vers maybe_old_export_vers old_decl_vers old_rule_vers -> -getClassOpNames new_name (ClassOpSig op _ _ src_loc) = new_name op src_loc -\end{code} + -- CHECK MODULE + checkModuleVersion old_mod_vers new_vers `thenRn` \ recompile -> + if not recompile then + returnRn upToDate + else + + -- CHECK EXPORT LIST + if checkExportList maybe_old_export_vers new_vers then + out_of_date (ptext SLIT("Export list changed")) + else + -- CHECK RULES + if old_rule_vers /= vers_rules new_vers then + out_of_date (ptext SLIT("Rules changed")) + else -%********************************************************* -%* * -\subsection{Reading an interface file} -%* * -%********************************************************* + -- CHECK ITEMS ONE BY ONE + checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenRn` \ recompile -> + if recompile then + returnRn outOfDate -- This one failed, so just bail out now + else + up_to_date (ptext SLIT("...but the bits I use haven't.")) -\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_` - getModuleHiMap `thenRn` \ himap -> - case (lookupFM himap real_mod_name) of - Nothing -> - traceRn (ptext SLIT("...failed")) `thenRn_` - returnRn Nothing - Just fpath -> - readIface fpath -{- - getSearchPathRn `thenRn` \ dirs -> - try dirs --} + }} where - real_mod_name = - case as_source of - HiBootFile -> 'b':moduleString mod_name - HiFile -> moduleString mod_name - - 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 [] = traceRn (ptext SLIT("...failed")) `thenRn_` - returnRn Nothing - - try ((dir,hisuf):dirs) - = readIface file_path `thenRn` \ read_result -> - case read_result of - Nothing -> try dirs - Just iface -> traceRn (ptext SLIT("...done")) `thenRn_` - returnRn (Just iface) - where - file_path = dir ++ '/' : moduleString mod_name ++ (mod_suffix hisuf) --} -\end{code} + doc_str = sep [ptext SLIT("need version info for"), ppr mod_name] -@readIface@ tries just the one file. +------------------------ +checkModuleVersion old_mod_vers new_vers + | vers_module new_vers == old_mod_vers + = up_to_date (ptext SLIT("Module version unchanged")) -\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 -> - case read_result of - Right contents -> - case parseIface contents (mkSrcLoc (mkFastString file_path) 1) of - Failed err -> failWithRn Nothing err - Succeeded (PIface iface) -> - if opt_D_show_rn_imports then - putDocRn (hcat[ptext SLIT("Read "), text file_path]) `thenRn_` - returnRn (Just iface) - else - returnRn (Just iface) - - Left err -> - if isDoesNotExistError err then - returnRn Nothing - else - failWithRn Nothing (cannaeReadFile file_path err) -\end{code} + | otherwise + = out_of_date (ptext SLIT("Module version has changed")) -%********************************************************* -%* * -\subsection{Utils} -%* * -%********************************************************* +------------------------ +checkExportList Nothing new_vers = upToDate +checkExportList (Just v) new_vers = v /= vers_exports new_vers -@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: +------------------------ +checkEntityUsage new_vers (name,old_vers) + = case lookupNameEnv new_vers name of -\begin{verbatim} - mkSearchPath "foo%.hi:.%.p_hi:baz%.mc_hi" - = [("foo",".hi"),( ".", ".p_hi"), ("baz",".mc_hi")] -\begin{verbatim} + Nothing -> -- We used it before, but it ain't there now + out_of_date (sep [ptext SLIT("No longer exported:"), ppr name]) -\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)] + Just new_vers -- It's there, but is it up to date? + | new_vers == old_vers -> returnRn upToDate + | otherwise -> out_of_date (sep [ptext SLIT("Out of date:"), ppr name]) + +up_to_date msg = traceRn msg `thenRn_` returnRn upToDate +out_of_date msg = traceRn msg `thenRn_` returnRn outOfDate \end{code} + %********************************************************* %* * \subsection{Errors} @@ -1061,30 +921,16 @@ mkSearchPath (Just s) %********************************************************* \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("Failed to find (optional) interface decl for"), - quotes (ppr name), ptext SLIT("desired at"), ppr loc] - -importDeclWarn mod name loc - = sep [ptext SLIT("Compiler tried to import decl from interface file with same name as module."), - ptext SLIT("(possible cause: module name clashes with interface file already in scope.)") +getDeclErr name + = vcat [ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name), + ptext SLIT("from module") <+> quotes (ppr (nameModule name)) + ] + +importDeclWarn name + = sep [ptext SLIT( + "Compiler tried to import decl from interface file with same name as module."), + ptext SLIT( + "(possible cause: module name clashes with interface file already in scope.)") ] $$ - hsep [ptext SLIT("Interface:"), quotes (pprModule mod), ptext SLIT(", name:"), quotes (ppr name), - ptext SLIT(", desired at:"), ppr loc - ] - + hsep [ptext SLIT("name:"), quotes (ppr name)] \end{code}