X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnIfaces.lhs;h=54ec9e641ef5944d4207a573c5153c85980e48c8;hb=29753e9aef6a2f4e4d4f739d4f54603832a022d9;hp=3024b8e6b3f515071f1d5a5adafa41734a5bf710;hpb=1fb1ab5d53a09607e7f6d2450806760688396387;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnIfaces.lhs b/ghc/compiler/rename/RnIfaces.lhs index 3024b8e..54ec9e6 100644 --- a/ghc/compiler/rename/RnIfaces.lhs +++ b/ghc/compiler/rename/RnIfaces.lhs @@ -1,746 +1,798 @@ % -% (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, closeDecls, -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 CmdLineOpts ( opt_IgnoreIfacePragmas, opt_NoPruneDecls ) +import HscTypes +import HsSyn ( HsDecl(..), Sig(..), TyClDecl(..), ConDecl(..), ConDetails(..), + InstDecl(..), HsType(..), hsTyVarNames, getBangType + ) +import HsImpExp ( ImportDecl(..) ) +import RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl ) +import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl, + extractHsTyNames, extractHsCtxtTyNames, + tyClDeclFVs, ruleDeclFVs, instDeclFVs ) -import HsPragmas ( noGenPragmas ) -import RdrHsSyn ( SYN_IE(RdrNameHsDecl), SYN_IE(RdrNameInstDecl), - RdrName, rdrNameOcc +import RnHiFiles ( tryLoadInterface, loadHomeInterface, loadInterface, + loadOrphanModules ) -import RnEnv ( newGlobalName, lookupRn, addImplicitOccsRn, availName, availNames, addAvailToNameSet ) -import RnSource ( rnHsType ) +import RnSource ( rnTyClDecl, rnInstDecl, rnIfaceRuleDecl ) +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 Id ( GenId, Id(..), idType, dataConTyCon, isDataCon ) -import TyCon ( TyCon, tyConDataCons, isSynTyCon, getSynTyConDefn ) +import Id ( idType ) import Type ( namesOfType ) -import TyVar ( GenTyVar ) -import SrcLoc ( mkIfaceSrcLoc ) -import PrelMods ( gHC__, isPreludeModule ) +import TyCon ( isSynTyCon, getSynTyConDefn ) +import Name ( Name {-instance NamedThing-}, nameOccName, + nameModule, isLocalName, nameUnique, + NamedThing(..) + ) +import Name ( elemNameEnv, delFromNameEnv ) +import Module ( Module, ModuleEnv, + moduleName, isHomeModule, + ModuleName, WhereFrom(..), + emptyModuleEnv, + extendModuleEnv_C, foldModuleEnv, lookupModuleEnv, + elemModuleSet, extendModuleSet + ) +import NameSet +import PrelInfo ( wiredInThingEnv, fractionalClassKeys ) +import TysWiredIn ( doubleTyCon ) +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 Util ( sortLt ) \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 - - -- 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 - } +@getInterfaceExports@ is called only for directly-imported modules. -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] - ) +\begin{code} +getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, [(ModuleName,Avails)]) +getInterfaceExports mod_name from + = loadInterface doc_str mod_name from `thenRn` \ iface -> + returnRn (mi_module iface, mi_exports iface) 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) + doc_str = sep [ppr mod_name, ptext SLIT("is directly imported")] \end{code} -%******************************************************** +%********************************************************* %* * -\subsection{Loading usage information} +\subsection{Keeping track of what we've slurped, and version numbers} %* * -%******************************************************** +%********************************************************* -\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] +mkImportInof 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. +We produce a line for every module B below the module, A, currently being +compiled: + import B ; +to record the fact that A does import B indireclty. 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. -checkModUsage [] = returnRn True -- Yes! Everything is up to date! +\begin{code} +mkImportInfo :: ModuleName -- Name of this module + -> [ImportDecl n] -- The import decls + -> RnMG [ImportVersion Name] -checkModUsage ((mod, old_mod_vers, old_local_vers) : rest) - = loadInterface doc_str mod `thenRn` \ ifaces -> +mkImportInfo this_mod imports + = getIfacesRn `thenRn` \ ifaces -> + getHomeIfaceTableRn `thenRn` \ hit -> let - Ifaces _ mod_vers _ decls _ _ _ _ = ifaces - maybe_new_mod_vers = lookupFM mod_vers mod - Just new_mod_vers = maybe_new_mod_vers + (imp_pkg_mods, imp_home_names) = iVSlurp ifaces + pit = iPIT ifaces + + import_all_mods :: [ModuleName] + -- Modules where we imported all the names + -- (apart from hiding some, perhaps) + import_all_mods = [ m | ImportDecl m _ _ _ imp_list _ <- imports, + import_all imp_list ] + where + import_all (Just (False, _)) = False -- Imports are specified explicitly + import_all other = True -- Everything is imported + + -- mv_map groups together all the things imported and used + -- from a particular module in this package + -- We use a finite map because we want the domain + mv_map :: ModuleEnv [Name] + mv_map = foldNameSet add_mv emptyModuleEnv imp_home_names + add_mv name mv_map = extendModuleEnv_C add_item mv_map mod [name] + where + mod = nameModule name + add_item names _ = name:names + + -- In our usage list we record + -- a) Specifically: Detailed version info for imports from modules in this package + -- Gotten from iVSlurp plus import_all_mods + -- + -- b) Everything: Just the module version for imports from modules in other packages + -- Gotten from iVSlurp plus import_all_mods + -- + -- c) NothingAtAll: The name only of modules, Baz, in this package that are 'below' us, + -- but which we didn't need at all (this is needed only to decide whether + -- to open Baz.hi or Baz.hi-boot higher up the tree). + -- 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 info. + -- These modules are in a combination of HIT/PIT and iImpModInfo + -- + -- d) NothingAtAll: The name only of all orphan modules we know of (this is needed + -- so that anyone who imports us can find the orphan modules) + -- These modules are in a combination of HIT/PIT and iImpModInfo + + import_info0 = foldModuleEnv mk_imp_info [] pit + import_info1 = foldModuleEnv mk_imp_info import_info0 hit + import_info = [ (mod_name, orphans, is_boot, NothingAtAll) + | (mod_name, (orphans, is_boot)) <- fmToList (iImpModInfo ifaces) ] ++ + import_info1 + + mk_imp_info :: ModIface -> [ImportVersion Name] -> [ImportVersion Name] + mk_imp_info iface so_far + + | Just ns <- lookupModuleEnv mv_map mod -- Case (a) + = go_for_it (Specifically mod_vers maybe_export_vers + (mk_import_items ns) rules_vers) + + | mod `elemModuleSet` imp_pkg_mods -- Case (b) + = go_for_it (Everything mod_vers) + + | import_all_mod -- Case (a) and (b); the import-all part + = if is_home_pkg_mod then + go_for_it (Specifically mod_vers (Just export_vers) [] rules_vers) + else + go_for_it (Everything mod_vers) + + | is_home_pkg_mod || has_orphans -- Case (c) or (d) + = go_for_it NothingAtAll + + | otherwise = so_far + where + go_for_it exports = (mod_name, has_orphans, mi_boot iface, exports) : so_far + + mod = mi_module iface + mod_name = moduleName mod + is_home_pkg_mod = isHomeModule mod + version_info = mi_version iface + version_env = vers_decls version_info + mod_vers = vers_module version_info + rules_vers = vers_rules version_info + export_vers = vers_exports version_info + import_all_mod = mod_name `elem` import_all_mods + has_orphans = mi_orphan iface + + -- The sort is to put them into canonical order + mk_import_items ns = [(n,v) | n <- sortLt lt_occ ns, + let v = lookupNameEnv version_env n `orElse` + pprPanic "mk_whats_imported" (ppr n) + ] + where + lt_occ n1 n2 = nameOccName n1 < nameOccName n2 + + maybe_export_vers | import_all_mod = Just (vers_exports version_info) + | otherwise = Nothing 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 + returnRn import_info +\end{code} - -- 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_` +%********************************************************* +%* * +\subsection{Slurping declarations} +%* * +%********************************************************* - -- 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 - where - doc_str = ppSep [ppPStr SLIT("need version info for"), pprModule PprDebug mod] +\begin{code} +------------------------------------------------------- +slurpImpDecls source_fvs + = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_` + -- The current slurped-set records all local things + slurpSourceRefs source_fvs `thenRn` \ (decls, needed) -> -checkEntityUsage mod decls [] - = returnRn True -- Yes! All up to date! + -- Then get everything else + closeDecls decls needed -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 -\end{code} +------------------------------------------------------- +slurpSourceRefs :: FreeVars -- Variables referenced in source + -> RnMG ([RenamedHsDecl], + FreeVars) -- Un-satisfied needs +-- The declaration (and hence home module) of each gate has +-- already been loaded +slurpSourceRefs source_fvs + = go_outer [] -- Accumulating decls + emptyFVs -- Unsatisfied needs + emptyFVs -- Accumulating gates + (nameSetToList source_fvs) -- Things whose defn hasn't been loaded yet + where + -- The outer loop repeatedly slurps the decls for the current gates + -- and the instance decls + + -- The outer loop is needed because consider + + 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 -> + rnIfaceInstDecls 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) + InTypeEnv ty_thing -> returnRn (decls, fvs, gates `plusFV` getWiredInGates ty_thing) + + HereItIs decl -> rnIfaceTyClDecl decl `thenRn` \ (new_decl, fvs1) -> + returnRn (TyClD new_decl : decls, + fvs1 `plusFV` fvs, + gates `plusFV` getGates source_fvs new_decl) +\end{code} -%********************************************************* -%* * -\subsection{Getting in a declaration} -%* * -%********************************************************* \begin{code} -importDecl :: Name -> Necessity -> RnMG (Maybe RdrNameHsDecl) - -- Returns Nothing for a wired-in or already-slurped decl - -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 - +------------------------------------------------------- +-- 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 rnIfaceRuleDecl rule_decls `thenRn` \ rule_decls' -> + let + rule_fvs = plusFVs (map ruleDeclFVs rule_decls') + in + traceRn (text "closeRules" <+> ppr rule_decls' $$ fsep (map ppr (nameSetToList rule_fvs))) `thenRn_` + closeDecls (map RuleD rule_decls' ++ decls) rule_fvs + + + +------------------------------------------------------- +-- 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 rn decls = mapRn (rnIfaceDecl rn) decls +rnIfaceDecl rn (mod, decl) = initIfaceRnMS mod (rn decl) + +rnIfaceInstDecls decls fvs gates inst_decls + = rnIfaceDecls rnInstDecl inst_decls `thenRn` \ inst_decls' -> + returnRn (map InstD inst_decls' ++ decls, + fvs `plusFV` plusFVs (map instDeclFVs inst_decls'), + gates `plusFV` plusFVs (map getInstDeclGates inst_decls')) + +rnIfaceTyClDecl (mod, decl) = initIfaceRnMS mod (rnTyClDecl decl) `thenRn` \ decl' -> + returnRn (decl', tyClDeclFVs decl') \end{code} + \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 +recordSlurp ifaces@(Ifaces { iDecls = (decls_map, n_slurped), + iSlurp = slurped_names, + iVSlurp = (imp_mods, imp_names) }) + avail + = ASSERT2( not (isLocalName (availName avail)), ppr avail ) + ifaces { iDecls = (decls_map', n_slurped+1), + iSlurp = new_slurped_names, + iVSlurp = new_vslurp } where - doc_str = ppSep [ppPStr SLIT("Need decl for"), ppr PprDebug name] - (mod,_) = modAndOcc name + decls_map' = foldl delFromNameEnv decls_map (availNames avail) + main_name = availName avail + mod = nameModule main_name + new_slurped_names = addAvailToNameSet slurped_names avail + new_vslurp | isHomeModule mod = (imp_mods, addOneToNameSet imp_names main_name) + | otherwise = (extendModuleSet imp_mods mod, imp_names) + +recordLocalSlurps new_names + = getIfacesRn `thenRn` \ ifaces -> + setIfacesRn (ifaces { iSlurp = iSlurp ifaces `unionNameSets` new_names }) \end{code} -@getWiredInDecl@ maps a wired-in @Name@ to what it makes available. -It behaves exactly as if the wired in decl were actually in an interface file. -Specifically, - * if the wired-in name is a data type constructor or a data constructor, - it brings in the type constructor and all the data constructors; and - marks as "occurrences" any free vars of the data con. - * similarly for synonum type constructor +%********************************************************* +%* * +\subsection{Extracting the `gates'} +%* * +%********************************************************* + +The gating story +~~~~~~~~~~~~~~~~~ +We want to avoid sucking in too many instance declarations. +An instance decl is only useful if the types and classes mentioned in +its 'head' are all available in the program being compiled. E.g. + + instance (..) => C (T1 a) (T2 b) where ... + +is only useful if C, T1 and T2 are all "available". So we keep +instance decls that have been parsed from .hi files, but not yet +slurped in, in a pool called the 'gated instance pool'. +Each has its set of 'gates': {C, T1, T2} in the above example. - * if the wired-in name is another wired-in Id, it marks as "occurrences" - the free vars of the Id's type. +More precisely, the gates of a module are the types and classes +that are mentioned in: - * it loads the interface file for the wired-in thing for the - sole purpose of making sure that its instance declarations are available + a) the source code + b) the type of an Id that's mentioned in the source code + [includes constructors and selectors] + c) the RHS of a type synonym that is a gate + d) the superclasses of a class that is a gate + e) the context of an instance decl that is slurped in -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. +We slurp in an instance decl from the gated instance pool iff -\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_` + all its gates are either in the gates of the module, + or are a previously-loaded class. - 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 latter constraint is because there might have been an instance +decl slurped in during an earlier compilation, like this: - get_wired | is_tycon -- ... a type constructor - = get_wired_tycon the_tycon - -- Else, must be a wired-in-Id + instance Foo a => Baz (Maybe a) where ... - | (isDataCon the_id) -- ... a wired-in data constructor - = get_wired_tycon (dataConTyCon the_id) +In the module being compiled we might need (Baz (Maybe T)), where T +is defined in this module, and hence we need (Foo T). So @Foo@ becomes +a gate. But there's no way to 'see' that, so we simply treat all +previously-loaded classes as gates. - | otherwise -- ... a wired-in non data-constructor - = get_wired_id the_id +Consructors and class operations +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +When we import a declaration like + data T = T1 Wibble | T2 Wobble -get_wired_id id - = addImplicitOccsRn (nameSetToList id_mentioned) `thenRn_` - returnRn (Avail (getName id)) - where - id_mentioned = namesOfType (idType id) +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. -get_wired_tycon tycon - | isSynTyCon tycon - = addImplicitOccsRn (nameSetToList mentioned) `thenRn_` - returnRn (Avail (getName tycon)) - where - (tyvars,ty) = getSynTyConDefn tycon - mentioned = namesOfType ty `minusNameSet` mkNameSet (map getName tyvars) +And that's just what (b) says: we only treat T1's type as a gate if +T1 is mentioned. getGates, which deals with decls we are slurping in, +has to be a bit careful, because a mention of T1 will slurp in T's whole +declaration. + +----------------------------- +@getGates@ takes a newly imported (and renamed) decl, and the free +vars of the source program, and extracts from the decl the gate names. + +\begin{code} +getGates :: FreeVars -- Things mentioned in the source program + -> RenamedTyClDecl + -> FreeVars + +getGates source_fvs decl + = get_gates (\n -> n `elemNameSet` source_fvs) decl + +get_gates is_used (IfaceSig {tcdType = ty}) = extractHsTyNames ty -get_wired_tycon tycon - | otherwise -- data or newtype - = addImplicitOccsRn (nameSetToList mentioned) `thenRn_` - returnRn (AvailTC tycon_name (tycon_name : map getName data_cons)) +get_gates is_used (ClassDecl { tcdCtxt = ctxt, tcdName = cls, tcdTyVars = tvs, tcdSigs = sigs}) + = (delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) sigs) + (hsTyVarNames tvs) + `addOneToNameSet` cls) + `plusFV` maybe_double where - tycon_name = getName tycon - data_cons = tyConDataCons tycon - mentioned = foldr (unionNameSets . namesOfType . idType) emptyNameSet data_cons -\end{code} + get (ClassOpSig n _ ty _) + | is_used n = 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 + +get_gates is_used (TySynonym {tcdTyVars = tvs, tcdSynRhs = ty}) + = delListFromNameSet (extractHsTyNames ty) (hsTyVarNames tvs) + -- A type synonym type constructor isn't a "gate" for instance decls + +get_gates is_used (TyData {tcdCtxt = ctxt, tcdName = tycon, tcdTyVars = tvs, tcdCons = cons}) + = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) cons) + (hsTyVarNames tvs) + `addOneToNameSet` tycon + where + get (ConDecl n _ tvs ctxt details _) + | is_used n + -- 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 + 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] -\begin{code} -checkSlurped name - = getIfacesRn `thenRn` \ (Ifaces _ _ _ _ slurped_names _ _ _) -> - returnRn (name `elemNameSet` slurped_names) + get_field (fs,t) | any is_used fs = get_bang t + | otherwise = emptyFVs -recordSlurp maybe_version avail - = 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_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 + get_bang bty = extractHsTyNames (getBangType bty) \end{code} - -%********************************************************* -%* * -\subsection{Getting other stuff} -%* * -%********************************************************* + +@getWiredInGates@ is just like @getGates@, but it sees a previously-loaded +thing rather than a declaration. \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 +getWiredInGates :: TyThing -> FreeVars +-- The TyThing is one that we already have in our type environment, either +-- a) because the TyCon or Id is wired in, or +-- b) from a previous compile +-- Either way, we might have instance decls in the (persistent) collection +-- of parsed-but-not-slurped instance decls that should be slurped in. +-- This might be the first module that mentions both the type and the class +-- for that instance decl, even though both the type and the class were +-- mentioned in other modules, and hence are in the type environment + +getWiredInGates (AnId the_id) = namesOfType (idType the_id) +getWiredInGates (AClass cl) = emptyFVs -- The superclasses must also be previously + -- loaded, and hence are automatically gates +getWiredInGates (ATyCon tc) + | isSynTyCon tc = delListFromNameSet (namesOfType ty) (map getName tyvars) + | otherwise = unitFV (getName tc) where - doc_str = ppSep [pprModule PprDebug mod, ppPStr SLIT("is directly imported")] + (tyvars,ty) = getSynTyConDefn tc +getInstDeclGates (InstDecl inst_ty _ _ _ _) = extractHsTyNames inst_ty +\end{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_` +\begin{code} +getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameInstDecl)] +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 + orphan_mods = + [mod | (mod, (True, _)) <- fmToList (iImpModInfo ifaces)] + in + loadOrphanModules orphan_mods `thenRn_` -- Now we're ready to grab the instance declarations -- Find the un-gated ones and return them, -- removing them from the bag kept in Ifaces - getIfacesRn `thenRn` \ ifaces -> + getIfacesRn `thenRn` \ ifaces -> + getTypeEnvRn `thenRn` \ lookup -> let - Ifaces this_mod mod_vers export_envs decls slurped_names imp_names insts inst_mods = ifaces - - -- An instance decl is ungated if all its gates have been slurped - select_ungated :: IfaceInst -- A gated inst decl - - -> ([(Module, RdrNameInstDecl)], [IfaceInst]) -- Accumulator - - -> ([(Module, RdrNameInstDecl)], -- The ungated ones - [IfaceInst]) -- Still gated, but with - -- depeleted gates - select_ungated (decl,gates) (ungated_decls, gated_decls) - | null remaining_gates - = (decl : ungated_decls, gated_decls) - | otherwise - = (ungated_decls, (decl, remaining_gates) : gated_decls) - where - remaining_gates = filter (not . (`elemNameSet` slurped_names)) gates - - (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 + (decls, new_insts) = selectGated gates lookup (iInsts ifaces) in - setIfacesRn new_ifaces `thenRn_` - returnRn un_gated_insts + setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_` + + 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 - load_it mod = loadInterface (doc_str mod) mod - doc_str mod = ppSep [pprModule PprDebug mod, ppPStr SLIT("is a special-instance module")] + gate_list = nameSetToList gates +ppr_brief_inst_decl (mod, InstDecl inst_ty _ _ _ _) + = case inst_ty of + HsForAllTy _ _ tau -> ppr tau + other -> ppr inst_ty -getSpecialInstModules :: RnMG [Module] -getSpecialInstModules - = getIfacesRn `thenRn` \ ifaces -> +getImportedRules :: RnMG [(Module,RdrNameRuleDecl)] +getImportedRules + | opt_IgnoreIfacePragmas = returnRn [] + | otherwise + = getIfacesRn `thenRn` \ ifaces -> + getTypeEnvRn `thenRn` \ lookup -> let - Ifaces _ _ _ _ _ _ _ inst_mods = ifaces + gates = iSlurp ifaces -- Anything at all that's been slurped + rules = iRules ifaces + (decls, new_rules) = selectGated gates lookup rules in - returnRn inst_mods -\end{code} + 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 lookup (decl_bag, n_slurped) + -- Select only those decls whose gates are *all* in 'gates' + -- or are a class in 'lookup' +#ifdef DEBUG + | opt_NoPruneDecls -- Just to try the effect of not gating at all + = let + decls = foldrBag (\ (_,d) ds -> d:ds) [] decl_bag -- Grab them all + in + (decls, (emptyBag, n_slurped + length decls)) -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". + | otherwise +#endif + = case foldrBag select ([], emptyBag) decl_bag of + (decls, new_bag) -> (decls, (new_bag, n_slurped + length decls)) + where + available n = n `elemNameSet` gates + || case lookup n of { Just (AClass c) -> True; other -> False } -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. + select (reqd, decl) (yes, no) + | all available reqd = (decl:yes, no) + | otherwise = (yes, (reqd,decl) `consBag` no) +\end{code} -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: +%********************************************************* +%* * +\subsection{Getting in a declaration} +%* * +%********************************************************* -1. Are A.o and A.hi correct? Then we can bale out early. -2. Should modules that import A be recompiled? +\begin{code} +importDecl :: Name -> RnMG ImportDeclResult + +data ImportDeclResult + = AlreadySlurped + | InTypeEnv TyThing + | HereItIs (Module, RdrNameTyClDecl) + +importDecl name + = -- STEP 1: Check if we've slurped it in while compiling this module + getIfacesRn `thenRn` \ ifaces -> + if name `elemNameSet` iSlurp ifaces then + 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). + -- STEP 2: Check if it's already in the type environment + getTypeEnvRn `thenRn` \ lookup -> + case lookup name of { + Just ty_thing | name `elemNameEnv` wiredInThingEnv + -> -- When we find a wired-in name we must load its home + -- module so that we find any instance decls lurking therein + loadHomeInterface wi_doc name `thenRn_` + returnRn (InTypeEnv ty_thing) -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. + | otherwise + -> returnRn (InTypeEnv ty_thing) ; -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. + Nothing -> -\begin{code} -getImportVersions :: Module -- Name of this module - -> Maybe [IE any] -- Export list for this module - -> RnMG (VersionInfo Name) -- Version info for these names + -- STEP 3: OK, we have to slurp it in from an interface file + -- First load the interface file + traceRn nd_doc `thenRn_` + loadHomeInterface nd_doc name `thenRn_` + getIfacesRn `thenRn` \ ifaces -> -getImportVersions this_mod exports - = getIfacesRn `thenRn` \ ifaces -> + -- STEP 4: Get the declaration out 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 in - returnRn [ (mod, mod_version mod, local_versions) - | (mod, local_versions) <- fmToList mv_map - ] - + case lookupNameEnv decls_map name of + Just (avail,_,decl) + -> setIfacesRn (recordSlurp ifaces avail) `thenRn_` + returnRn (HereItIs decl) + + Nothing + -> addErrRn (getDeclErr name) `thenRn_` + returnRn AlreadySlurped + } 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 (\ ls _ -> (v:ls)) mv_map mod [v] - where - (mod,_) = modAndOcc name + wi_doc = ptext SLIT("need home module for wired in thing") <+> ppr name + nd_doc = ptext SLIT("need decl for") <+> ppr name - add_mod mv_map mod = addToFM mv_map mod [] \end{code} -%********************************************************* + +%******************************************************** %* * -\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@). +%******************************************************** -It doesn't deal with source-code specific things: ValD, DefD. They -are handled by the sourc-code specific stuff in RnNames. +@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. \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) +type RecompileRequired = Bool +upToDate = False -- Recompile not required +outOfDate = True -- Recompile required + +recompileRequired :: FilePath -- Only needed for debug msgs + -> Bool -- Source unchanged + -> ModIface -- Old interface + -> RnMG RecompileRequired +recompileRequired iface_path source_unchanged iface + = traceHiDiffsRn (text "Considering whether compilation is required for" <+> text iface_path <> colon) `thenRn_` + + -- CHECK WHETHER THE SOURCE HAS CHANGED + if not source_unchanged then + traceHiDiffsRn (nest 4 (text "Source file changed or recompilation check turned off")) `thenRn_` + returnRn outOfDate + else -getConFieldNames new_name [] = returnRn [] + -- Source code unchanged and no errors yet... carry on + checkList [checkModUsage u | u <- mi_usages iface] -getClassOpNames new_name (ClassOpSig op _ _ src_loc) = new_name op src_loc +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} +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, _, is_boot, whats_imported) + = -- Load the imported interface is possible + -- We use tryLoadInterface, because failure is not an error + -- (might just be that the old .hi file for this module is out of date) + -- We use ImportByUser/ImportByUserSource as the 'from' flag, + -- a) because we need to know whether to load the .hi-boot file + -- b) because loadInterface things matters are amiss if we + -- ImportBySystem an interface it knows nothing about + let + doc_str = sep [ptext SLIT("need version info for"), ppr mod_name] + from | is_boot = ImportByUserSource + | otherwise = ImportByUser + in + tryLoadInterface doc_str mod_name from `thenRn` \ (iface, 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 -%********************************************************* -%* * -\subsection{Reading an interface file} -%* * -%********************************************************* + Nothing -> + let + new_vers = mi_version iface + new_decl_vers = vers_decls new_vers + in + case whats_imported of { -- NothingAtAll dealt with earlier -\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 - 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} + 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 ; -@readIface@ trys just one file. + Specifically old_mod_vers maybe_old_export_vers old_decl_vers old_rule_vers -> -\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) + -- 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 -\end{code} + -- CHECK RULES + if old_rule_vers /= vers_rules new_vers then + out_of_date (ptext SLIT("Rules changed")) + else -mkSearchPath takes a string consisting of a colon-separated list of directories, and turns it into -a list of directories. For example: + -- 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.")) - mkSearchPath "foo:.:baz" = ["foo", ".", "baz"] + }} -\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 +------------------------ +checkModuleVersion old_mod_vers new_vers + | vers_module new_vers == old_mod_vers + = up_to_date (ptext SLIT("Module version unchanged")) + + | otherwise + = out_of_date (ptext SLIT("Module version has changed")) + +------------------------ +checkExportList Nothing new_vers = upToDate +checkExportList (Just v) new_vers = v /= vers_exports new_vers + +------------------------ +checkEntityUsage new_vers (name,old_vers) + = case lookupNameEnv new_vers name of + + Nothing -> -- We used it before, but it ain't there now + out_of_date (sep [ptext SLIT("No longer exported:"), ppr name]) + + 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 = traceHiDiffsRn msg `thenRn_` returnRn upToDate +out_of_date msg = traceHiDiffsRn 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)) + ] \end{code}