X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnIfaces.lhs;h=8680d59bf170553632b9dac189110314fbf79a71;hb=4102e5cec12cd96f59260aee2c6da01616b97467;hp=3024b8e6b3f515071f1d5a5adafa41734a5bf710;hpb=1fb1ab5d53a09607e7f6d2450806760688396387;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnIfaces.lhs b/ghc/compiler/rename/RnIfaces.lhs index 3024b8e..8680d59 100644 --- a/ghc/compiler/rename/RnIfaces.lhs +++ b/ghc/compiler/rename/RnIfaces.lhs @@ -1,746 +1,929 @@ % -% (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} -#include "HsVersions.h" - -module RnIfaces ( +module RnIfaces + ( getInterfaceExports, - getImportedInstDecls, - getSpecialInstModules, - importDecl, recordSlurp, - getImportVersions, - - checkUpToDate, + recordLocalSlurps, + mkImportInfo, - getDeclBinders, - mkSearchPath - ) where + slurpImpDecls, -IMP_Ubiq() + RecompileRequired, outOfDate, upToDate, recompileRequired + ) +where +#include "HsVersions.h" -import CmdLineOpts ( opt_HiSuffix, opt_HiSuffixPrelude ) -import HsSyn ( HsDecl(..), TyDecl(..), ClassDecl(..), HsTyVar, Bind, HsExpr, Sig(..), HsType(..), - HsBinds(..), MonoBinds, DefaultDecl, ConDecl(..), BangType, IfaceSig(..), - FixityDecl(..), Fixity, Fake, InPat, InstDecl(..), SYN_IE(Version), HsIdInfo, - IE(..) - ) -import HsPragmas ( noGenPragmas ) -import RdrHsSyn ( SYN_IE(RdrNameHsDecl), SYN_IE(RdrNameInstDecl), - RdrName, rdrNameOcc +import CmdLineOpts ( DynFlags, opt_NoPruneDecls, opt_NoPruneTyDecls, opt_IgnoreIfacePragmas ) +import HscTypes +import HsSyn ( HsDecl(..), InstDecl(..), HsType(..) ) +import HsImpExp ( ImportDecl(..) ) +import BasicTypes ( Version, defaultFixity ) +import RdrHsSyn ( RdrNameHsDecl, RdrNameTyClDecl, RdrNameInstDecl ) +import RnHiFiles ( tryLoadInterface, loadHomeInterface, loadInterface, + loadOrphanModules ) -import RnEnv ( newGlobalName, lookupRn, addImplicitOccsRn, availName, availNames, addAvailToNameSet ) -import RnSource ( rnHsType ) +import RnSource ( rnTyClDecl, rnDecl ) +import RnEnv import RnMonad -import ParseIface ( parseIface ) - -import ErrUtils ( SYN_IE(Error), SYN_IE(Warning) ) -import FiniteMap ( FiniteMap, emptyFM, unitFM, lookupFM, addToFM, addToFM_C, addListToFM, fmToList ) -import Name ( Name {-instance NamedThing-}, Provenance, OccName(..), - modAndOcc, occNameString, moduleString, pprModule, - NameSet(..), emptyNameSet, unionNameSets, nameSetToList, - minusNameSet, mkNameSet, elemNameSet, - isWiredInName, maybeWiredInTyConName, maybeWiredInIdName +import Name ( Name {-instance NamedThing-}, nameOccName, + nameModule, isLocallyDefined, + NamedThing(..), + elemNameEnv ) -import Id ( GenId, Id(..), idType, dataConTyCon, isDataCon ) -import TyCon ( TyCon, tyConDataCons, isSynTyCon, getSynTyConDefn ) -import Type ( namesOfType ) -import TyVar ( GenTyVar ) -import SrcLoc ( mkIfaceSrcLoc ) -import PrelMods ( gHC__, isPreludeModule ) +import Module ( Module, ModuleEnv, + moduleName, isModuleInThisPackage, + ModuleName, WhereFrom(..), + emptyModuleEnv, lookupModuleEnvByName, + extendModuleEnv_C, lookupWithDefaultModuleEnv + ) +import NameSet +import PrelInfo ( wiredInThingEnv ) +import Maybes ( orElse ) +import FiniteMap +import Outputable import Bag -import Maybes ( MaybeErr(..), expectJust, maybeToBool ) -import ListSetOps ( unionLists ) -import Pretty -import PprStyle ( PprStyle(..) ) -import Util ( pprPanic, pprTrace ) -import StringBuffer ( StringBuffer, hGetStringBuffer, freeStringBuffer ) +import List ( nub ) \end{code} - %********************************************************* %* * -\subsection{Loading a new interface file} +\subsection{Getting what a module exports} %* * %********************************************************* -\begin{code} -loadInterface :: Pretty -> Module -> RnMG Ifaces -loadInterface doc_str load_mod - = getIfacesRn `thenRn` \ ifaces -> - let - Ifaces this_mod mod_vers_map export_envs decls all_names imp_names insts inst_mods = ifaces - in - -- CHECK WHETHER WE HAVE IT ALREADY - if maybeToBool (lookupFM export_envs load_mod) - then - returnRn ifaces -- Already in the cache; don't re-read it - else +@getInterfaceExports@ is called only for directly-imported modules. - -- READ THE MODULE IN - findAndReadIface doc_str load_mod `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_export_envs = addToFM export_envs load_mod ([],[]) - new_ifaces = Ifaces this_mod mod_vers_map - new_export_envs - decls all_names imp_names insts 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 - mapRn loadExport exports `thenRn` \ avails_s -> - foldlRn (loadDecl load_mod) decls rd_decls `thenRn` \ new_decls -> - foldlRn (loadInstDecl load_mod) insts rd_insts `thenRn` \ new_insts -> - let - export_env = (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_vers_map load_mod mod_vers) - (addToFM export_envs load_mod export_env) - new_decls - all_names imp_names - new_insts - new_inst_mods - in - setIfacesRn new_ifaces `thenRn_` - returnRn new_ifaces +\begin{code} +getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, 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) } - -loadExport :: ExportItem -> RnMG [AvailInfo] -loadExport (mod, entities) - = mapRn load_entity entities - where - new_name occ = newGlobalName mod occ - --- The communcation between this little code fragment and the "entity" rule --- in ParseIface.y is a bit gruesome. The idea is that things which are --- destined to be AvailTCs show up as (occ, [non-empty-list]), whereas --- things destined to be Avails show up as (occ, []) - - load_entity (occ, occs) - = new_name occ `thenRn` \ name -> - if null occs then - returnRn (Avail name) - else - mapRn new_name occs `thenRn` \ names -> - returnRn (AvailTC name names) - -loadDecl :: Module -> DeclsMap - -> (Version, RdrNameHsDecl) - -> RnMG DeclsMap -loadDecl mod decls_map (version, decl) - = getDeclBinders new_implicit_name decl `thenRn` \ avail -> - returnRn (addListToFM decls_map - [(name,(version,avail,decl)) | name <- availNames avail] - ) - where - new_implicit_name rdr_name loc = newGlobalName mod (rdrNameOcc rdr_name) - -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 InterfaceMode ( - findOccurrencesRn (rnHsType munged_inst_ty) - ) `thenRn` \ gate_names -> - returnRn (((mod_name, decl), gate_names) `consBag` insts) + where + doc_str = sep [ppr mod_name, ptext SLIT("is directly imported")] \end{code} -%******************************************************** +%********************************************************* %* * -\subsection{Loading usage information} +\subsection{Instance declarations are handled specially} %* * -%******************************************************** +%********************************************************* \begin{code} -checkUpToDate :: Module -> RnMG Bool -- True <=> no need to recompile -checkUpToDate mod_name - = findAndReadIface doc_str mod_name `thenRn` \ read_result -> - case read_result of - Nothing -> -- Old interface file not found, so we'd better bail out - traceRn (ppSep [ppPStr SLIT("Didnt find old iface"), - pprModule PprDebug 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 = ppSep [ppPStr SLIT("Need usage info from"), pprModule PprDebug mod_name] - - -checkModUsage [] = returnRn True -- Yes! Everything is up to date! - -checkModUsage ((mod, old_mod_vers, old_local_vers) : rest) - = loadInterface doc_str mod `thenRn` \ ifaces -> +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 - Ifaces _ mod_vers _ decls _ _ _ _ = ifaces - maybe_new_mod_vers = lookupFM mod_vers mod - Just new_mod_vers = maybe_new_mod_vers + orphan_mods = + [mod | (mod, (True, _, False)) <- fmToList (iImpModInfo ifaces)] 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 - returnRn False - else + loadOrphanModules orphan_mods `thenRn_` - -- If the module version hasn't changed, just move on - if new_mod_vers == old_mod_vers then - traceRn (ppSep [ppPStr SLIT("Module version unchanged:"), pprModule PprDebug mod]) `thenRn_` - checkModUsage rest - else - traceRn (ppSep [ppPStr SLIT("Module version has changed:"), pprModule PprDebug mod]) `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 + (decls, new_insts) = selectGated gates (iInsts ifaces) + in + setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_` - -- New module version, so check entities inside - checkEntityUsage mod decls old_local_vers `thenRn` \ up_to_date -> - if up_to_date then - traceRn (ppPStr 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 + 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 - doc_str = ppSep [ppPStr SLIT("need version info for"), pprModule PprDebug mod] + gate_list = nameSetToList gates +ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _)) + = case inst_ty of + HsForAllTy _ _ tau -> ppr tau + other -> ppr inst_ty -checkEntityUsage mod decls [] - = returnRn True -- Yes! All up to date! - -checkEntityUsage mod decls ((occ_name,old_vers) : rest) - = newGlobalName mod occ_name `thenRn` \ name -> - case lookupFM decls name of - - Nothing -> -- We used it before, but it ain't there now - traceRn (ppSep [ppPStr SLIT("...and this no longer exported:"), ppr PprDebug 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 - -> traceRn (ppSep [ppPStr SLIT("...and this is out of date:"), ppr PprDebug name]) `thenRn_` - returnRn False +getImportedRules :: RnMG [(Module,RdrNameHsDecl)] +getImportedRules + | opt_IgnoreIfacePragmas = returnRn [] + | otherwise + = getIfacesRn `thenRn` \ ifaces -> + let + gates = iSlurp ifaces -- Anything at all that's been slurped + rules = iRules ifaces + (decls, new_rules) = selectGated gates rules + in + if null decls then + returnRn [] + else + setIfacesRn (ifaces { iRules = new_rules }) `thenRn_` + traceRn (sep [text "getImportedRules:", + text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_` + returnRn decls + +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 + + | otherwise +#endif + = foldrBag select ([], emptyBag) decl_bag + where + 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 :: Name -> Necessity -> RnMG (Maybe RdrNameHsDecl) - -- Returns Nothing for a wired-in or already-slurped decl +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: -importDecl name necessity - = checkSlurped name `thenRn` \ already_slurped -> - if already_slurped then - returnRn Nothing -- Already dealt with - else - if isWiredInName name then - getWiredInDecl name - else - getIfacesRn `thenRn` \ ifaces -> - let - Ifaces this_mod _ _ _ _ _ _ _ = ifaces - (mod,_) = modAndOcc name - in - if mod == this_mod then -- Don't bring in decls from - pprTrace "importDecl wierdness:" (ppr PprDebug name) $ - returnRn Nothing -- the renamed module's own interface file - -- - else - getNonWiredInDecl name necessity +\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} -\end{code} +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. + +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. \begin{code} -getNonWiredInDecl :: Name -> Necessity -> RnMG (Maybe RdrNameHsDecl) -getNonWiredInDecl name necessity - = traceRn doc_str `thenRn_` - loadInterface doc_str mod `thenRn` \ (Ifaces _ _ _ decls _ _ _ _) -> - case lookupFM decls name of - - Just (version,avail,decl) -> recordSlurp (Just version) avail `thenRn_` - returnRn (Just decl) - - Nothing -> -- Can happen legitimately for "Optional" occurrences - case necessity of { - Optional -> addWarnRn (getDeclWarn name); - other -> addErrRn (getDeclErr name) - } `thenRn_` - returnRn Nothing - where - doc_str = ppSep [ppPStr SLIT("Need decl for"), ppr PprDebug name] - (mod,_) = modAndOcc name -\end{code} +mkImportInfo :: ModuleName -- Name of this module + -> [ImportDecl n] -- The import decls + -> RnMG [ImportVersion Name] -@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, +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 ] - * 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. + import_all (Just (False, _)) = False -- Imports are specified explicitly + import_all other = True -- Everything is imported - * similarly for synonum type constructor + mod_map = iImpModInfo ifaces + imp_names = iVSlurp ifaces + pit = iPIT ifaces - * if the wired-in name is another wired-in Id, it marks as "occurrences" - the free vars of the Id's type. + -- mv_map groups together all the things imported from a particular module. + mv_map :: ModuleEnv [Name] + mv_map = foldr add_mv emptyModuleEnv imp_names - * it loads the interface file for the wired-in thing for the - sole purpose of making sure that its instance declarations are available + add_mv name mv_map = addItem mv_map (nameModule name) name -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. + -- 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. + -- + -- 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 + traceRn (text "Modules in Ifaces: " <+> fsep (map ppr (keysFM mod_map))) `thenRn_` + returnRn import_info + + +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} + +%********************************************************* +%* * +\subsection{Slurping declarations} +%* * +%********************************************************* + \begin{code} -getWiredInDecl name - = -- Force in the home module in case it has instance decls for - -- the thing we are interested in - (if not is_tycon || mod == gHC__ then - returnRn () -- Mini hack 1: no point for non-tycons; 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 - else - loadInterface doc_str mod `thenRn_` - returnRn () - ) `thenRn_` +------------------------------------------------------- +slurpImpDecls source_fvs + = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_` - get_wired `thenRn` \ avail -> - recordSlurp Nothing avail `thenRn_` - returnRn Nothing -- No declaration to process further - where - doc_str = ppSep [ppPStr SLIT("Need home module for wired in thing"), ppr PprDebug name] - (mod,_) = modAndOcc 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) -> - get_wired | is_tycon -- ... a type constructor - = get_wired_tycon the_tycon - -- Else, must be a wired-in-Id + -- Then get everything else + closeDecls decls needed `thenRn` \ decls1 -> - | (isDataCon the_id) -- ... a wired-in data constructor - = get_wired_tycon (dataConTyCon the_id) + -- Finally, get any deferred data type decls + slurpDeferredDecls decls1 `thenRn` \ final_decls -> - | otherwise -- ... a wired-in non data-constructor - = get_wired_id the_id + returnRn final_decls -get_wired_id id - = addImplicitOccsRn (nameSetToList id_mentioned) `thenRn_` - returnRn (Avail (getName id)) - where - id_mentioned = namesOfType (idType id) +------------------------------------------------------- +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 -get_wired_tycon tycon - | isSynTyCon tycon - = addImplicitOccsRn (nameSetToList mentioned) `thenRn_` - returnRn (Avail (getName tycon)) +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 - (tyvars,ty) = getSynTyConDefn tycon - mentioned = namesOfType ty `minusNameSet` mkNameSet (map getName tyvars) + -- The outer loop repeatedly slurps the decls for the current gates + -- and the instance decls -get_wired_tycon tycon - | otherwise -- data or newtype - = addImplicitOccsRn (nameSetToList mentioned) `thenRn_` - returnRn (AvailTC tycon_name (tycon_name : map getName data_cons)) + -- 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} + + +\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 + + | 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 - tycon_name = getName tycon - data_cons = tyConDataCons tycon - mentioned = foldr (unionNameSets . namesOfType . idType) emptyNameSet data_cons + 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) \end{code} \begin{code} -checkSlurped name - = getIfacesRn `thenRn` \ (Ifaces _ _ _ _ slurped_names _ _ _) -> - returnRn (name `elemNameSet` slurped_names) +getSlurped + = getIfacesRn `thenRn` \ ifaces -> + returnRn (iSlurp ifaces) -recordSlurp maybe_version avail +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 + ifaces { iSlurp = new_slurped_names, iVSlurp = new_imp_names } + +recordLocalSlurps local_avails = getIfacesRn `thenRn` \ ifaces -> let - Ifaces this_mod mod_vers export_envs decls slurped_names imp_names insts inst_mods = ifaces - new_slurped_names = addAvailToNameSet slurped_names avail + new_slurped_names = foldl addAvailToNameSet (iSlurp ifaces) local_avails + in + setIfacesRn (ifaces { iSlurp = new_slurped_names }) +\end{code} - new_imp_names = case maybe_version of - Just version -> (availName avail, version) : imp_names - Nothing -> imp_names - new_ifaces = Ifaces this_mod mod_vers export_envs decls - new_slurped_names - new_imp_names - insts - inst_mods - in - setIfacesRn new_ifaces + +%********************************************************* +%* * +\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} +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{Getting other stuff} -%* * +%* * +\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} -getInterfaceExports :: Module -> RnMG (Avails, [(OccName,Fixity)]) -getInterfaceExports mod - = loadInterface doc_str mod `thenRn` \ (Ifaces _ _ export_envs _ _ _ _ _) -> - case lookupFM export_envs 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 stuff -> returnRn stuff +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 - doc_str = ppSep [pprModule PprDebug mod, ppPStr SLIT("is directly imported")] - + 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 -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_` + 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] - -- 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_vers export_envs decls slurped_names imp_names insts inst_mods = ifaces + get_field (fs,t) | any (`elemNameSet` source_fvs) fs = get_bang t + | otherwise = emptyFVs - -- An instance decl is ungated if all its gates have been slurped - select_ungated :: IfaceInst -- A gated inst decl + 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` slurped_names)) gates + (tyvars,ty) = getSynTyConDefn tc - (un_gated_insts, still_gated_insts) = foldrBag select_ungated ([], []) insts - - new_ifaces = Ifaces this_mod mod_vers export_envs decls slurped_names imp_names - (listToBag still_gated_insts) - inst_mods - in - setIfacesRn new_ifaces `thenRn_` - returnRn un_gated_insts - where - load_it mod = loadInterface (doc_str mod) mod - doc_str mod = ppSep [pprModule PprDebug mod, ppPStr 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} -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. +%********************************************************* +%* * +\subsection{Getting in a declaration} +%* * +%********************************************************* -What about this? - module A( f, g ) where module B( f ) where - import B( f ) f = h 3 - g = ... h = ... +\begin{code} +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 -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: + -- Check if we slurped it in while compiling this module + getIfacesRn `thenRn` \ ifaces -> + if name `elemNameSet` iSlurp ifaces then + returnRn AlreadySlurped + else -1. Are A.o and A.hi correct? Then we can bale out early. -2. Should modules that import A be recompiled? + -- 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 -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). + -- 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 -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. + else getNonWiredInDecl name + where + 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 + tycon_name = availName avail +-} -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. + Just (avail,_,decl) + -> setIfacesRn (recordSlurp ifaces avail) `thenRn_` + returnRn (HereItIs decl) -\begin{code} -getImportVersions :: Module -- Name of this module - -> Maybe [IE any] -- Export list for this module - -> RnMG (VersionInfo Name) -- Version info for these names + Nothing + -> addErrRn (getDeclErr needed_name) `thenRn_` + returnRn AlreadySlurped + where + doc_str = ptext SLIT("need decl for") <+> ppr needed_name -getImportVersions this_mod exports - = getIfacesRn `thenRn` \ ifaces -> +{- OMIT FOR NOW +getDeferredDecls :: RnMG [(Module, RdrNameHsDecl)] +getDeferredDecls + = getIfacesRn `thenRn` \ ifaces -> let - Ifaces _ mod_versions_map _ _ _ imp_names _ _ = ifaces - mod_version mod = expectJust "import_versions" (lookupFM mod_versions_map mod) - - -- mv_map groups together all the things imported from a particular module. - mv_map, mv_map_mod :: FiniteMap Module [LocalVersion 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 - - mv_map = foldl add_mv mv_map_mod imp_names - -- mv_map adds the version numbers of things exported individually + decls_map = iDecls ifaces + deferred_names = nameSetToList (iDeferred ifaces) + get_abstract_decl n = case lookupNameEnv decls_map n of + Just (_, _, _, decl) -> decl in - returnRn [ (mod, mod_version mod, local_versions) - | (mod, local_versions) <- fmToList mv_map - ] + traceRn (sep [text "getDeferredDecls", nest 4 (fsep (map ppr deferred_names))]) `thenRn_` + returnRn (map get_abstract_decl deferred_names) +-} +\end{code} - where - export_mods = case exports of - Nothing -> [] - Just es -> [mod | IEModuleContents mod <- es, mod /= this_mod] +@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. - add_mv mv_map v@(name, version) - = addToFM_C (\ ls _ -> (v:ls)) mv_map mod [v] - where - (mod,_) = modAndOcc name +\item similarly for synonum type constructor - add_mod mv_map mod = addToFM mv_map mod [] -\end{code} +\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 : sub_names)) - -getDeclBinders new_name (TyD (TyNew _ tycon _ (NewConDecl con _ con_loc) _ _ src_loc)) - = new_name tycon src_loc `thenRn` \ tycon_name -> - new_name con src_loc `thenRn` \ con_name -> - returnRn (AvailTC tycon_name [tycon_name, con_name]) - -getDeclBinders new_name (TyD (TySynonym tycon _ _ src_loc)) - = new_name tycon src_loc `thenRn` \ tycon_name -> - returnRn (Avail tycon_name) - -getDeclBinders new_name (ClD (ClassDecl _ cname _ sigs _ _ src_loc)) - = new_name cname src_loc `thenRn` \ class_name -> - mapRn (getClassOpNames new_name) sigs `thenRn` \ sub_names -> - returnRn (AvailTC class_name (class_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 _ src_loc : rest) - = new_name con src_loc `thenRn` \ n -> - getConFieldNames new_name rest `thenRn` \ ns -> - returnRn (n:ns) - -getConFieldNames new_name (NewConDecl con _ src_loc : rest) - = new_name con src_loc `thenRn` \ n -> - getConFieldNames new_name rest `thenRn` \ ns -> - returnRn (n:ns) - -getConFieldNames new_name (ConOpDecl _ con _ src_loc : rest) - = new_name con src_loc `thenRn` \ n -> - getConFieldNames new_name rest `thenRn` \ ns -> - returnRn (n:ns) - -getConFieldNames new_name (RecConDecl con 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 [] = returnRn [] + 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 ; -getClassOpNames new_name (ClassOpSig op _ _ src_loc) = new_name op src_loc -\end{code} + Specifically old_mod_vers maybe_old_export_vers old_decl_vers old_rule_vers -> + -- 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 -%********************************************************* -%* * -\subsection{Reading an interface file} -%* * -%********************************************************* + -- CHECK RULES + if old_rule_vers /= vers_rules new_vers then + out_of_date (ptext SLIT("Rules changed")) + else -\begin{code} -findAndReadIface :: Pretty -> Module -> RnMG (Maybe ParsedIface) - -- Nothing <=> file not found, or unreadable, or illegible - -- Just x <=> successfully found and parsed -findAndReadIface doc_str mod - = traceRn trace_msg `thenRn_` - getSearchPathRn `thenRn` \ dirs -> - try dirs dirs + -- 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.")) + + }} where - trace_msg = ppHang (ppBesides [ppPStr SLIT("Reading interface for "), - pprModule PprDebug mod, ppSemi]) - 4 (ppBesides [ppPStr SLIT("reason: "), doc_str]) - - mod_str = moduleString mod - hisuf = - if isPreludeModule mod then - case opt_HiSuffixPrelude of { Just hisuf -> hisuf; _ -> ".hi"} - else - case opt_HiSuffix of {Just hisuf -> hisuf; _ -> ".hi"} - - try all_dirs [] = traceRn (ppPStr SLIT("...failed")) `thenRn_` - returnRn Nothing - - try all_dirs (dir:dirs) - = readIface file_path `thenRn` \ read_result -> - case read_result of - Nothing -> try all_dirs dirs - Just iface -> traceRn (ppPStr SLIT("...done")) `thenRn_` - returnRn (Just iface) - where - file_path = dir ++ "/" ++ moduleString mod ++ hisuf -\end{code} + doc_str = sep [ptext SLIT("need version info for"), ppr mod_name] -@readIface@ trys just 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 -> ---OLD: = ioToRnMG (readFile file_path) `thenRn` \ read_result -> - case read_result of - Right contents -> case parseIface contents of - Failed err -> --ioToRnMG (freeStringBuffer contents) `thenRn` \ _ -> - failWithRn Nothing err - Succeeded iface -> --ioToRnMG (freeStringBuffer contents) `thenRn` \ _ -> - returnRn (Just iface) - - Left (NoSuchThing _) -> returnRn Nothing - - Left err -> failWithRn Nothing - (cannaeReadFile file_path err) + | otherwise + = out_of_date (ptext SLIT("Module version has changed")) -\end{code} +------------------------ +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 turns it into -a list of directories. For example: +------------------------ +checkEntityUsage new_vers (name,old_vers) + = case lookupNameEnv new_vers name of - mkSearchPath "foo:.:baz" = ["foo", ".", "baz"] + 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 = ["."] -mkSearchPath (Just s) - = go s - where - go "" = [] - go s = first : go (drop 1 rest) - where - (first,rest) = span (/= ':') s + 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} -%* * +%* * %********************************************************* \begin{code} -noIfaceErr mod sty - = ppBesides [ppPStr SLIT("Could not find valid interface file for "), ppQuote (pprModule sty mod)] --- , ppStr " in"]) 4 (ppAboves (map ppStr dirs)) - -cannaeReadFile file err sty - = ppBesides [ppPStr SLIT("Failed in reading file: "), ppStr file, ppPStr SLIT("; error="), ppStr (show err)] - -getDeclErr name sty - = ppSep [ppPStr SLIT("Failed to find interface decl for"), ppr sty name] - -getDeclWarn name sty - = ppSep [ppPStr SLIT("Warning: failed to find (optional) interface decl for"), ppr sty name] +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("name:"), quotes (ppr name)] \end{code}