X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnIfaces.lhs;h=e62b780ea49a0c2ce8321a45b073a639fc6d0c65;hb=8fbe28ca67a6c07575aee35bfade43e967ad792e;hp=2e10d79e2e606ffd8c4b3ec331b133174fedce86;hpb=e1a4f2a5be6e4cd06d96b601fefd519c2569ba99;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnIfaces.lhs b/ghc/compiler/rename/RnIfaces.lhs index 2e10d79..e62b780 100644 --- a/ghc/compiler/rename/RnIfaces.lhs +++ b/ghc/compiler/rename/RnIfaces.lhs @@ -4,547 +4,516 @@ \section[RnIfaces]{Cacheing and Renaming of Interfaces} \begin{code} -module RnIfaces ( - getInterfaceExports, - getImportedInstDecls, getImportedRules, - lookupFixity, loadHomeInterface, - importDecl, recordSlurp, - getImportVersions, getSlurped, +module RnIfaces + ( + getInterfaceExports, + recordLocalSlurps, + mkImportInfo, - checkUpToDate, + slurpImpDecls, closeDecls, - getDeclBinders, getDeclSysBinders, - removeContext -- removeContext probably belongs somewhere else - ) where + RecompileRequired, outOfDate, upToDate, recompileRequired + ) +where #include "HsVersions.h" -import CmdLineOpts ( opt_NoPruneDecls, opt_IgnoreIfacePragmas ) -import HsSyn ( HsDecl(..), TyClDecl(..), InstDecl(..), IfaceSig(..), - HsType(..), ConDecl(..), IE(..), ConDetails(..), Sig(..), - ForeignDecl(..), ForKind(..), isDynamic, - FixitySig(..), RuleDecl(..), - isClassOpSig +import CmdLineOpts ( opt_IgnoreIfacePragmas, opt_NoPruneDecls ) +import HscTypes +import HsSyn ( HsDecl(..), Sig(..), TyClDecl(..), ConDecl(..), ConDetails(..), + InstDecl(..), HsType(..), hsTyVarNames, getBangType ) -import BasicTypes ( Version, NewOrData(..), defaultFixity ) -import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameTyClDecl, RdrNameRuleDecl, - extractHsTyRdrNames +import HsImpExp ( ImportDecl(..) ) +import RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl ) +import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl, + extractHsTyNames, extractHsCtxtTyNames, + tyClDeclFVs, ruleDeclFVs, instDeclFVs ) -import RnEnv ( mkImportedGlobalName, newImportedBinder, mkImportedGlobalFromRdrName, - lookupOccRn, lookupImplicitOccRn, - pprAvail, - availName, availNames, addAvailToNameSet, - FreeVars, emptyFVs +import RnHiFiles ( tryLoadInterface, loadHomeInterface, loadInterface, + loadOrphanModules ) +import RnSource ( rnTyClDecl, rnInstDecl, rnIfaceRuleDecl ) +import RnEnv import RnMonad -import RnHsSyn ( RenamedHsDecl ) -import ParseIface ( parseIface, IfaceStuff(..) ) - -import FiniteMap ( FiniteMap, sizeFM, emptyFM, delFromFM, - lookupFM, addToFM, addToFM_C, addListToFM, - fmToList, elemFM, foldFM - ) -import Name ( Name {-instance NamedThing-}, - nameModule, isLocallyDefined, - isWiredInName, nameUnique, NamedThing(..) +import Id ( idType ) +import Type ( namesOfType ) +import TyCon ( isSynTyCon, getSynTyConDefn ) +import Name ( Name {-instance NamedThing-}, nameOccName, + nameModule, isLocalName, nameUnique, + NamedThing(..) ) -import Module ( Module, moduleString, pprModule, - mkVanillaModule, pprModuleName, - moduleUserString, moduleName, isLibModule, +import Name ( elemNameEnv, delFromNameEnv ) +import Module ( Module, ModuleEnv, + moduleName, isHomeModule, ModuleName, WhereFrom(..), + emptyModuleEnv, + extendModuleEnv_C, foldModuleEnv, lookupModuleEnv, + elemModuleSet, extendModuleSet ) -import RdrName ( RdrName, rdrNameOcc ) import NameSet -import Var ( Id ) -import SrcLoc ( mkSrcLoc, SrcLoc ) -import PrelMods ( pREL_GHC ) -import PrelInfo ( cCallishTyKeys, thinAirModules ) -import Bag -import Maybes ( MaybeErr(..), maybeToBool, orElse ) -import ListSetOps ( unionLists ) +import PrelInfo ( wiredInThingEnv, fractionalClassKeys ) +import TysWiredIn ( doubleTyCon ) +import Maybes ( orElse ) +import FiniteMap import Outputable -import Unique ( Unique ) -import StringBuffer ( StringBuffer, hGetStringBuffer ) -import FastString ( mkFastString ) -import ErrUtils ( Message ) -import Lex -import Outputable - -import IO ( isDoesNotExistError ) -import List ( nub ) +import Bag +import Util ( sortLt ) \end{code} %********************************************************* %* * -\subsection{Loading a new interface file} +\subsection{Getting what a module exports} %* * %********************************************************* +@getInterfaceExports@ is called only for directly-imported modules. + \begin{code} -loadHomeInterface :: SDoc -> Name -> RnM d Ifaces -loadHomeInterface doc_str name - = loadInterface doc_str (moduleName (nameModule name)) ImportBySystem `thenRn` \ (_, ifaces) -> - returnRn ifaces - -loadOrphanModules :: [ModuleName] -> RnM d () -loadOrphanModules mods - | null mods = returnRn () - | otherwise = traceRn (text "Loading orphan modules:" <+> fsep (map pprModuleName mods)) `thenRn_` - mapRn_ load mods `thenRn_` - returnRn () +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 - load mod = loadInterface (pprModuleName mod <+> ptext SLIT("is a orphan-instance module")) mod ImportBySystem - -loadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d (Module, Ifaces) -loadInterface doc_str mod_name from - = getIfacesRn `thenRn` \ ifaces -> - let - mod_map = iImpModInfo ifaces - mod_info = lookupFM mod_map mod_name - in_map = maybeToBool mod_info - in - - -- Issue a warning for a redundant {- SOURCE -} import - -- It's redundant if the moduld is in the iImpModInfo at all, - -- because we arrange to read all the ordinary imports before - -- any of the {- SOURCE -} imports - warnCheckRn (not (in_map && case from of {ImportByUserSource -> True; other -> False})) - (warnRedundantSourceImport mod_name) `thenRn_` - - -- CHECK WHETHER WE HAVE IT ALREADY - case mod_info of { - Just (_, _, Just (load_mod, _, _)) - -> -- We're read it already so don't re-read it - returnRn (load_mod, ifaces) ; - - mod_map_result -> - - -- READ THE MODULE IN - findAndReadIface doc_str mod_name from in_map - `thenRn` \ (hi_boot_read, read_result) -> - case read_result of { - Nothing -> -- Not found, so add an empty export env to the Ifaces map - -- so that we don't look again - let - mod = mkVanillaModule mod_name - new_mod_map = addToFM mod_map mod_name (0, False, Just (mod, False, [])) - new_ifaces = ifaces { iImpModInfo = new_mod_map } - in - setIfacesRn new_ifaces `thenRn_` - failWithRn (mod, new_ifaces) (noIfaceErr mod hi_boot_read) ; - - -- Found and parsed! - Just (mod, iface) -> - - -- LOAD IT INTO Ifaces - - -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined - --- names is done correctly (notably, whether this is an .hi file or .hi-boot file). - -- If we do loadExport first the wrong info gets into the cache (unless we - -- explicitly tag each export which seems a bit of a bore) - - getModuleRn `thenRn` \ this_mod_nm -> - let - rd_decls = pi_decls iface - in - foldlRn (loadDecl mod) (iDecls ifaces) rd_decls `thenRn` \ new_decls -> - foldlRn (loadInstDecl mod) (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts -> - foldlRn (loadRule mod) (iRules ifaces) (pi_rules iface) `thenRn` \ new_rules -> - foldlRn (loadFixDecl mod_name) (iFixes ifaces) rd_decls `thenRn` \ new_fixities -> - mapRn (loadExport this_mod_nm) (pi_exports iface) `thenRn` \ avails_s -> - let - -- For an explicit user import, add to mod_map info about - -- the things the imported module depends on, extracted - -- from its usage info. - mod_map1 = case from of - ImportByUser -> addModDeps mod mod_map (pi_usages iface) - other -> mod_map - - -- Now add info about this module - mod_map2 = addToFM mod_map1 mod_name mod_details - mod_details = (pi_mod iface, pi_orphan iface, Just (mod, hi_boot_read, concat avails_s)) - - new_ifaces = ifaces { iImpModInfo = mod_map2, - iDecls = new_decls, - iFixes = new_fixities, - iRules = new_rules, - iInsts = new_insts } - in - setIfacesRn new_ifaces `thenRn_` - returnRn (mod, new_ifaces) - }} + doc_str = sep [ppr mod_name, ptext SLIT("is directly imported")] +\end{code} -addModDeps :: Module -> ImportedModuleInfo - -> [ImportVersion a] -> ImportedModuleInfo -addModDeps mod mod_deps new_deps - = foldr add mod_deps new_deps - where - is_lib = isLibModule mod -- Don't record dependencies when importing a library module - add (imp_mod, version, has_orphans, _) deps - | is_lib && not has_orphans = deps - | otherwise = addToFM_C combine deps imp_mod (version, has_orphans, Nothing) - -- Record dependencies for modules that are - -- either are dependent via a non-library module - -- or contain orphan rules or instance decls - - -- Don't ditch a module that's already loaded!! - combine old@(_, _, Just _) new = old - combine old@(_, _, Nothing) new = new - -loadExport :: ModuleName -> ExportItem -> RnM d [AvailInfo] -loadExport this_mod (mod, entities) - | mod == this_mod = returnRn [] - -- If the module exports anything defined in this module, just ignore it. - -- Reason: otherwise it looks as if there are two local definition sites - -- for the thing, and an error gets reported. Easiest thing is just to - -- filter them out up front. This situation only arises if a module - -- imports itself, or another module that imported it. (Necessarily, - -- this invoves a loop.) Consequence: if you say - -- module A where - -- import B( AType ) - -- type AType = ... - -- - -- module B( AType ) where - -- import {-# SOURCE #-} A( AType ) - -- - -- then you'll get a 'B does not export AType' message. A bit bogus - -- but it's a bogus thing to do! - | otherwise - = mapRn (load_entity mod) entities - where - new_name mod occ = mkImportedGlobalName mod occ - - load_entity mod (Avail occ) - = new_name mod occ `thenRn` \ name -> - returnRn (Avail name) - load_entity mod (AvailTC occ occs) - = new_name mod occ `thenRn` \ name -> - mapRn (new_name mod) occs `thenRn` \ names -> - returnRn (AvailTC name names) - - -loadFixDecl :: ModuleName -> FixityEnv - -> (Version, RdrNameHsDecl) - -> RnM d FixityEnv -loadFixDecl mod_name fixity_env (version, FixD sig@(FixitySig rdr_name fixity loc)) - = -- Ignore the version; when the fixity changes the version of - -- its 'host' entity changes, so we don't need a separate version - -- number for fixities - mkImportedGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name -> - let - new_fixity_env = addToNameEnv fixity_env name (FixitySig name fixity loc) - in - returnRn new_fixity_env +%********************************************************* +%* * +\subsection{Keeping track of what we've slurped, and version numbers} +%* * +%********************************************************* - -- Ignore the other sorts of decl -loadFixDecl mod_name fixity_env other_decl = returnRn fixity_env +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. -loadDecl :: Module - -> DeclsMap - -> (Version, RdrNameHsDecl) - -> RnM d DeclsMap +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. -loadDecl mod decls_map (version, decl) - = getDeclBinders new_name decl `thenRn` \ maybe_avail -> - case maybe_avail of { - Nothing -> returnRn decls_map; -- No bindings - Just avail -> +\begin{code} +mkImportInfo :: ModuleName -- Name of this module + -> [ImportDecl n] -- The import decls + -> RnMG [ImportVersion Name] - getDeclSysBinders new_name decl `thenRn` \ sys_bndrs -> +mkImportInfo this_mod imports + = getIfacesRn `thenRn` \ ifaces -> + getHomeIfaceTableRn `thenRn` \ hit -> let - main_name = availName avail - new_decls_map = foldl add_decl decls_map - [ (name, (version, avail, name==main_name, (mod, decl'))) - | name <- sys_bndrs ++ availNames avail] - add_decl decls_map (name, stuff) - = WARN( name `elemNameEnv` decls_map, ppr name ) - addToNameEnv decls_map name stuff - in - returnRn new_decls_map - } - where - -- newImportedBinder puts into the cache the binder with the - -- module information set correctly. When the decl is later renamed, - -- the binding site will thereby get the correct module. - new_name rdr_name loc = newImportedBinder mod rdr_name - - {- - If a signature decl is being loaded, and optIgnoreIfacePragmas is on, - we toss away unfolding information. - - Also, if the signature is loaded from a module we're importing from source, - we do the same. This is to avoid situations when compiling a pair of mutually - recursive modules, peering at unfolding info in the interface file of the other, - e.g., you compile A, it looks at B's interface file and may as a result change - its interface file. Hence, B is recompiled, maybe changing its interface file, - which will the unfolding info used in A to become invalid. Simple way out is to - just ignore unfolding info. - - [Jan 99: I junked the second test above. If we're importing from an hi-boot - file there isn't going to *be* any pragma info. Maybe the above comment - dates from a time where we picked up a .hi file first if it existed?] - -} - decl' = case decl of - SigD (IfaceSig name tp ls loc) | opt_IgnoreIfacePragmas - -> SigD (IfaceSig name tp [] loc) - other -> decl - -loadInstDecl :: Module - -> Bag GatedDecl - -> RdrNameInstDecl - -> RnM d (Bag GatedDecl) -loadInstDecl mod 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 ... + (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 -- - -- Here the gates are Baz and T, but *not* Foo. - let - munged_inst_ty = removeContext inst_ty - free_names = extractHsTyRdrNames munged_inst_ty + -- 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 - setModuleRn (moduleName mod) $ - mapRn mkImportedGlobalFromRdrName free_names `thenRn` \ gate_names -> - returnRn ((mkNameSet gate_names, (mod, InstD decl)) `consBag` insts) - - --- In interface files, the instance decls now look like --- forall a. Foo a -> Baz (T a) --- so we have to strip off function argument types as well --- as the bit before the '=>' (which is always empty in interface files) -removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty) -removeContext ty = removeFuns ty - -removeFuns (MonoFunTy _ ty) = removeFuns ty -removeFuns ty = ty - - -loadRule :: Module -> Bag GatedDecl - -> RdrNameRuleDecl -> RnM d (Bag GatedDecl) --- "Gate" the rule simply by whether the rule variable is --- needed. We can refine this later. -loadRule mod rules decl@(IfaceRuleDecl var body src_loc) - = setModuleRn (moduleName mod) $ - mkImportedGlobalFromRdrName var `thenRn` \ var_name -> - returnRn ((unitNameSet var_name, (mod, RuleD decl)) `consBag` rules) + returnRn import_info \end{code} - -%******************************************************** -%* * -\subsection{Loading usage information} -%* * -%******************************************************** +%********************************************************* +%* * +\subsection{Slurping declarations} +%* * +%********************************************************* \begin{code} -checkUpToDate :: ModuleName -> RnMG Bool -- True <=> no need to recompile -checkUpToDate mod_name - = getIfacesRn `thenRn` \ ifaces -> - findAndReadIface doc_str mod_name - ImportByUser - (error "checkUpToDate") `thenRn` \ (_, read_result) -> - - -- CHECK WHETHER WE HAVE IT ALREADY - case read_result of - Nothing -> -- Old interface file not found, so we'd better bail out - traceRn (sep [ptext SLIT("Didnt find old iface"), - pprModuleName mod_name]) `thenRn_` - returnRn False - - Just (_, iface) - -> -- Found it, so now check it - checkModUsage (pi_usages iface) - where - -- Only look in current directory, with suffix .hi - doc_str = sep [ptext SLIT("need usage info from"), pprModuleName mod_name] +------------------------------------------------------- +slurpImpDecls source_fvs + = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_` -checkModUsage [] = returnRn True -- Yes! Everything is up to date! + -- The current slurped-set records all local things + slurpSourceRefs source_fvs `thenRn` \ (decls, needed) -> -checkModUsage ((mod_name, old_mod_vers, _, whats_imported) : rest) - = loadInterface doc_str mod_name ImportBySystem `thenRn` \ (mod, ifaces) -> - let - maybe_mod_vers = case lookupFM (iImpModInfo ifaces) mod_name of - Just (version, _, Just (_, _, _)) -> Just version - other -> Nothing - in - case maybe_mod_vers of { - Nothing -> -- If we can't find a version number for the old module then - -- bail out saying things aren't up to date - traceRn (sep [ptext SLIT("Can't find version number for module"), - pprModuleName mod_name]) - `thenRn_` returnRn False ; - - Just new_mod_vers -> - - -- If the module version hasn't changed, just move on - if new_mod_vers == old_mod_vers then - traceRn (sep [ptext SLIT("Module version unchanged:"), pprModuleName mod_name]) - `thenRn_` checkModUsage rest - else - traceRn (sep [ptext SLIT("Module version has changed:"), pprModuleName mod_name]) - `thenRn_` - -- Module version changed, so check entities inside - - -- If the usage info wants to say "I imported everything from this module" - -- it does so by making whats_imported equal to Everything - -- In that case, we must recompile - case whats_imported of { - Everything -> traceRn (ptext SLIT("...and I needed the whole module")) `thenRn_` - returnRn False; -- Bale out - - Specifically old_local_vers -> - - -- Non-empty usage list, so check item by item - checkEntityUsage mod_name (iDecls ifaces) old_local_vers `thenRn` \ up_to_date -> - if up_to_date then - traceRn (ptext SLIT("...but the bits I use haven't.")) `thenRn_` - checkModUsage rest -- This one's ok, so check the rest - else - returnRn False -- This one failed, so just bail out now - }} - where - doc_str = sep [ptext SLIT("need version info for"), pprModuleName mod_name] + -- Then get everything else + closeDecls decls needed -checkEntityUsage mod decls [] - = returnRn True -- Yes! All up to date! +------------------------------------------------------- +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 -checkEntityUsage mod decls ((occ_name,old_vers) : rest) - = mkImportedGlobalName mod occ_name `thenRn` \ name -> - case lookupNameEnv decls name of - - Nothing -> -- We used it before, but it ain't there now - putDocRn (sep [ptext SLIT("No longer exported:"), ppr name]) - `thenRn_` returnRn False - - Just (new_vers,_,_,_) -- It's there, but is it up to date? - | new_vers == old_vers - -- Up to date, so check the rest - -> checkEntityUsage mod decls rest - - | otherwise - -- Out of date, so bale out - -> putDocRn (sep [ptext SLIT("Out of date:"), ppr name]) `thenRn_` - returnRn False +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 -> RnMG (Maybe (Module, RdrNameHsDecl)) - -- Returns Nothing for - -- (a) wired in name - -- (b) local decl - -- (c) already slurped +------------------------------------------------------- +-- 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 -importDecl name - | isWiredInName name - = returnRn Nothing | otherwise - = getSlurped `thenRn` \ already_slurped -> - if name `elemNameSet` already_slurped then - returnRn Nothing -- Already dealt with - else - if isLocallyDefined name then -- Don't bring in decls from - -- the renamed module's own interface file - addWarnRn (importDeclWarn name) `thenRn_` - returnRn Nothing - else - getNonWiredInDecl name + = 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 -> RnMG (Maybe (Module, RdrNameHsDecl)) -getNonWiredInDecl needed_name - = traceRn doc_str `thenRn_` - loadHomeInterface doc_str needed_name `thenRn` \ ifaces -> - case lookupNameEnv (iDecls ifaces) needed_name of - - Just (version,avail,_,decl) - -> recordSlurp (Just version) avail `thenRn_` - returnRn (Just decl) - - Nothing -- Can happen legitimately for "Optional" occurrences - -> addErrRn (getDeclErr needed_name) `thenRn_` - returnRn Nothing +getSlurped + = getIfacesRn `thenRn` \ ifaces -> + returnRn (iSlurp ifaces) + +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 = ptext SLIT("need decl for") <+> ppr needed_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, -\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. -\item similarly for synonum type constructor -\item if the wired-in name is another wired-in Id, it marks as ``occurrences'' - the free vars of the Id's type. +%********************************************************* +%* * +\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 ... -\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. +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. + +More precisely, the gates of a module are the types and classes +that are mentioned in: + + 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 + +We slurp in an instance decl from the gated instance pool iff + all its gates are either in the gates of the module, + or are a previously-loaded class. +The latter constraint is because there might have been an instance +decl slurped in during an earlier compilation, like this: - -%********************************************************* -%* * -\subsection{Getting what a module exports} -%* * -%********************************************************* + instance Foo a => Baz (Maybe a) where ... -@getInterfaceExports@ is called only for directly-imported modules. +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. + +Consructors and class operations +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +When we import a declaration like + + data T = T1 Wibble | T2 Wobble + +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. + +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} -getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, Avails) -getInterfaceExports mod_name from - = loadInterface doc_str mod_name from `thenRn` \ (mod, ifaces) -> - case lookupFM (iImpModInfo ifaces) mod_name 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 (mod, []) - - Just (_, _, Just (mod, _, avails)) -> returnRn (mod, avails) +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 _ ty _ _) + = extractHsTyNames ty + +get_gates is_used (ClassDecl ctxt cls tvs _ sigs _ _ _ ) + = (delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) sigs) + (hsTyVarNames tvs) + `addOneToNameSet` cls) + `plusFV` maybe_double + where + 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 tycon tvs ty _) + = delListFromNameSet (extractHsTyNames ty) (hsTyVarNames tvs) + -- A type synonym type constructor isn't a "gate" for instance decls + +get_gates is_used (TyData _ ctxt tycon tvs cons _ _ _ _ _) + = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) cons) + (hsTyVarNames tvs) + `addOneToNameSet` tycon where - doc_str = sep [pprModuleName mod_name, ptext SLIT("is directly imported")] + 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] + + get_field (fs,t) | any is_used fs = get_bang t + | otherwise = emptyFVs + + get_bang bty = extractHsTyNames (getBangType bty) \end{code} +@getWiredInGates@ is just like @getGates@, but it sees a previously-loaded +thing rather than a declaration. -%********************************************************* -%* * -\subsection{Instance declarations are handled specially} -%* * -%********************************************************* +\begin{code} +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 + (tyvars,ty) = getSynTyConDefn tc + +getInstDeclGates (InstDecl inst_ty _ _ _ _) = extractHsTyNames inst_ty +\end{code} \begin{code} -getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)] +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, Nothing)) <- fmToList (iImpModInfo ifaces)] + [mod | (mod, (True, _)) <- fmToList (iImpModInfo ifaces)] in loadOrphanModules orphan_mods `thenRn_` @@ -552,8 +521,9 @@ getImportedInstDecls gates -- Find the un-gated ones and return them, -- removing them from the bag kept in Ifaces getIfacesRn `thenRn` \ ifaces -> + getTypeEnvRn `thenRn` \ lookup -> let - (decls, new_insts) = selectGated gates (iInsts ifaces) + (decls, new_insts) = selectGated gates lookup (iInsts ifaces) in setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_` @@ -565,385 +535,259 @@ getImportedInstDecls gates where gate_list = nameSetToList gates - load_home gate | isLocallyDefined gate - = returnRn () - | otherwise - = loadHomeInterface (ppr gate <+> text "is an instance gate") gate `thenRn_` - returnRn () - -ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _)) +ppr_brief_inst_decl (mod, InstDecl inst_ty _ _ _ _) = case inst_ty of HsForAllTy _ _ tau -> ppr tau other -> ppr inst_ty -getImportedRules :: RnMG [(Module,RdrNameHsDecl)] -getImportedRules +getImportedRules :: RnMG [(Module,RdrNameRuleDecl)] +getImportedRules + | opt_IgnoreIfacePragmas = returnRn [] + | otherwise = getIfacesRn `thenRn` \ ifaces -> + getTypeEnvRn `thenRn` \ lookup -> let gates = iSlurp ifaces -- Anything at all that's been slurped - (decls, new_rules) = selectGated gates (iRules ifaces) + rules = iRules ifaces + (decls, new_rules) = selectGated gates lookup rules in - setIfacesRn (ifaces { iRules = new_rules }) `thenRn_` + if null decls then + returnRn [] + else + setIfacesRn (ifaces { iRules = new_rules }) `thenRn_` traceRn (sep [text "getImportedRules:", - text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_` + text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_` returnRn decls -selectGated gates decl_bag +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 - = (foldrBag (\ (_,d) ds -> d:ds) [] decl_bag, emptyBag) -- Grab them all + = let + decls = foldrBag (\ (_,d) ds -> d:ds) [] decl_bag -- Grab them all + in + (decls, (emptyBag, n_slurped + length decls)) | otherwise #endif - = foldrBag select ([], emptyBag) decl_bag + = 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 } + select (reqd, decl) (yes, no) - | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no) - | otherwise = (yes, (reqd,decl) `consBag` no) - -lookupFixity :: Name -> RnMS Fixity -lookupFixity name - | isLocallyDefined name - = getFixityEnv `thenRn` \ local_fix_env -> - case lookupNameEnv local_fix_env name of - Just (FixitySig _ fix _) -> returnRn fix - Nothing -> returnRn defaultFixity - - | otherwise -- Imported - = loadHomeInterface doc name `thenRn` \ ifaces -> - case lookupNameEnv (iFixes ifaces) name of - Just (FixitySig _ fix _) -> returnRn fix - Nothing -> returnRn defaultFixity - where - doc = ptext SLIT("Checking fixity for") <+> ppr name + | all available reqd = (decl:yes, no) + | otherwise = (yes, (reqd,decl) `consBag` no) \end{code} %********************************************************* %* * -\subsection{Keeping track of what we've slurped, and version numbers} +\subsection{Getting in a declaration} %* * %********************************************************* -getImportVersions figures out -what the ``usage information'' for this moudule is; -that is, what it must record in its interface file as the things it uses. -It records: -\begin{itemize} -\item anything reachable from its body code -\item any module exported with a @module Foo@. -\end{itemize} -% -Why the latter? Because if @Foo@ changes then this module's export list -will change, so we must recompile this module at least as far as -making a new interface file --- but in practice that means complete -recompilation. - -What about this? -\begin{verbatim} - module A( f, g ) where | module B( f ) where - import B( f ) | f = h 3 - g = ... | h = ... -\end{verbatim} -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@: -\begin{enumerate} -\item Are @A.o@ and @A.hi@ correct? Then we can bale out early. -\item Should modules that import @A@ be recompiled? -\end{enumerate} -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@ -(and this usage-version info isn't used by any importer). - -For (2), because of the tricky @B.h@ question above, -we ensure that @A.hi@ is touched -(even if identical to its previous version) -if A's recompilation was triggered by an imported @.hi@ file date change. -Given that, there's no need to record @B.f@ in @A@'s usages. - -On the other hand, if @A@ exports @module B@, -then we {\em do} count @module B@ among @A@'s usages, -because we must recompile @A@ to ensure that @A.hi@ changes appropriately. - \begin{code} -getImportVersions :: ModuleName -- Name of this module - -> Maybe [IE any] -- Export list for this module - -> RnMG (VersionInfo Name) -- Version info for these names +importDecl :: Name -> RnMG ImportDeclResult -getImportVersions this_mod exports - = getIfacesRn `thenRn` \ ifaces -> - let - mod_map = iImpModInfo ifaces - imp_names = iVSlurp ifaces - - -- mv_map groups together all the things imported from a particular module. - mv_map1, mv_map2 :: FiniteMap ModuleName (WhatsImported Name) - - -- mv_map1 records all the modules that have a "module M" - -- in this module's export list with an "Everything" - mv_map1 = foldr add_mod emptyFM export_mods - - -- mv_map2 adds the version numbers of things exported individually - mv_map2 = foldr add_mv mv_map1 imp_names - - -- Build the result list by adding info for each module. - -- For (a) library modules - -- (b) source-imported modules - -- we do something special. We don't want to record detailed usage information. - -- Indeed we don't want to record them at all unless they contain orphans, - -- which we must never lose track of. - mk_version_info mod_name (version, has_orphans, cts) so_far - | lib_or_source_imported && not has_orphans - = so_far -- Don't record any usage info for this module - - | lib_or_source_imported -- Has orphans; record the module but not - -- detailed version information for the imports - = (mod_name, version, has_orphans, Specifically []) : so_far - - | otherwise - = (mod_name, version, has_orphans, whats_imported) : so_far - where - whats_imported = case lookupFM mv_map2 mod_name of - Just wi -> wi - Nothing -> Specifically [] - - lib_or_source_imported = case cts of - Just (mod, boot_import, _) -> isLibModule mod || boot_import - Nothing -> False - in - returnRn (foldFM mk_version_info [] mod_map) - where - export_mods = case exports of - Nothing -> [] - Just es -> [mod | IEModuleContents mod <- es, mod /= this_mod] +data ImportDeclResult + = AlreadySlurped + | InTypeEnv TyThing + | HereItIs (Module, RdrNameTyClDecl) - add_mv v@(name, version) mv_map - = addToFM_C add_item mv_map mod (Specifically [v]) - where - mod = moduleName (nameModule name) +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 - add_item Everything _ = Everything - add_item (Specifically xs) _ = Specifically (v:xs) + -- 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) - add_mod mod mv_map = addToFM mv_map mod Everything -\end{code} + | otherwise + -> returnRn (InTypeEnv ty_thing) ; -\begin{code} -getSlurped - = getIfacesRn `thenRn` \ ifaces -> - returnRn (iSlurp ifaces) + Nothing -> -recordSlurp maybe_version avail - = getIfacesRn `thenRn` \ ifaces@(Ifaces { iSlurp = slurped_names, - iVSlurp = imp_names }) -> - let - new_slurped_names = addAvailToNameSet slurped_names avail + -- 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 -> - new_imp_names = case maybe_version of - Just version -> (availName avail, version) : imp_names - Nothing -> imp_names + -- STEP 4: Get the declaration out + let + (decls_map, _) = iDecls ifaces in - setIfacesRn (ifaces { iSlurp = new_slurped_names, - iVSlurp = new_imp_names }) + 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 + wi_doc = ptext SLIT("need home module for wired in thing") <+> ppr name + nd_doc = ptext SLIT("need decl for") <+> ppr name + \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 -> RnM d Name) -- New-name function - -> RdrNameHsDecl - -> RnM d (Maybe AvailInfo) - -getDeclBinders new_name (TyClD (TyData _ _ tycon _ condecls _ _ src_loc)) - = new_name tycon src_loc `thenRn` \ tycon_name -> - getConFieldNames new_name condecls `thenRn` \ sub_names -> - returnRn (Just (AvailTC tycon_name (tycon_name : nub sub_names))) - -- The "nub" is because getConFieldNames can legitimately return duplicates, - -- when a record declaration has the same field in multiple constructors - -getDeclBinders new_name (TyClD (TySynonym tycon _ _ src_loc)) - = new_name tycon src_loc `thenRn` \ tycon_name -> - returnRn (Just (AvailTC tycon_name [tycon_name])) +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 -getDeclBinders new_name (TyClD (ClassDecl _ cname _ sigs _ _ _ _ _ src_loc)) - = new_name cname src_loc `thenRn` \ class_name -> + -- Source code unchanged and no errors yet... carry on + checkList [checkModUsage u | u <- mi_usages iface] - -- Record the names for the class ops +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 - -- just want class-op sigs - op_sigs = filter isClassOpSig sigs + doc_str = sep [ptext SLIT("need version info for"), ppr mod_name] + from | is_boot = ImportByUserSource + | otherwise = ImportByUser in - mapRn (getClassOpNames new_name) op_sigs `thenRn` \ sub_names -> - - returnRn (Just (AvailTC class_name (class_name : sub_names))) + tryLoadInterface doc_str mod_name from `thenRn` \ (iface, maybe_err) -> -getDeclBinders new_name (SigD (IfaceSig var ty prags src_loc)) - = new_name var src_loc `thenRn` \ var_name -> - returnRn (Just (Avail var_name)) + 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 -getDeclBinders new_name (FixD _) = returnRn Nothing + Nothing -> + let + new_vers = mi_version iface + new_decl_vers = vers_decls new_vers + in + case whats_imported of { -- NothingAtAll dealt with earlier - -- foreign declarations -getDeclBinders new_name (ForD (ForeignDecl nm kind _ dyn _ loc)) - | binds_haskell_name kind dyn - = new_name nm loc `thenRn` \ name -> - returnRn (Just (Avail name)) + 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 ; - | otherwise -- a foreign export - = lookupImplicitOccRn nm `thenRn_` - returnRn Nothing + Specifically old_mod_vers maybe_old_export_vers old_decl_vers old_rule_vers -> -getDeclBinders new_name (DefD _) = returnRn Nothing -getDeclBinders new_name (InstD _) = returnRn Nothing -getDeclBinders new_name (RuleD _) = returnRn Nothing + -- 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 -binds_haskell_name (FoImport _) _ = True -binds_haskell_name FoLabel _ = True -binds_haskell_name FoExport ext_nm = isDynamic ext_nm + -- CHECK RULES + if old_rule_vers /= vers_rules new_vers then + out_of_date (ptext SLIT("Rules changed")) + else ----------------- -getConFieldNames new_name (ConDecl con _ _ (RecCon fielddecls) src_loc : rest) - = mapRn (\n -> new_name n src_loc) (con:fields) `thenRn` \ cfs -> - getConFieldNames new_name rest `thenRn` \ ns -> - returnRn (cfs ++ ns) - where - fields = concat (map fst fielddecls) + -- 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.")) -getConFieldNames new_name (ConDecl con _ _ condecl src_loc : rest) - = new_name con src_loc `thenRn` \ n -> - (case condecl of - NewCon _ (Just f) -> - new_name f src_loc `thenRn` \ new_f -> - returnRn [n,new_f] - _ -> returnRn [n]) `thenRn` \ nn -> - getConFieldNames new_name rest `thenRn` \ ns -> - returnRn (nn ++ ns) + }} -getConFieldNames new_name [] = returnRn [] +------------------------ +checkModuleVersion old_mod_vers new_vers + | vers_module new_vers == old_mod_vers + = up_to_date (ptext SLIT("Module version unchanged")) -getClassOpNames new_name (ClassOpSig op _ _ _ src_loc) = new_name op src_loc -\end{code} + | otherwise + = out_of_date (ptext SLIT("Module version has changed")) -@getDeclSysBinders@ gets the implicit binders introduced by a decl. -A the moment that's just the tycon and datacon that come with a class decl. -They aren't returned by @getDeclBinders@ because they aren't in scope; -but they {\em should} be put into the @DeclsMap@ of this module. +------------------------ +checkExportList Nothing new_vers = upToDate +checkExportList (Just v) new_vers = v /= vers_exports new_vers -Note that this excludes the default-method names of a class decl, -and the dict fun of an instance decl, because both of these have -bindings of their own elsewhere. +------------------------ +checkEntityUsage new_vers (name,old_vers) + = case lookupNameEnv new_vers name of -\begin{code} -getDeclSysBinders new_name (TyClD (ClassDecl _ cname _ sigs _ _ tname dname snames src_loc)) - = new_name dname src_loc `thenRn` \ datacon_name -> - new_name tname src_loc `thenRn` \ tycon_name -> - sequenceRn [new_name n src_loc | n <- snames] `thenRn` \ scsel_names -> - returnRn (tycon_name : datacon_name : scsel_names) - -getDeclSysBinders new_name other_decl - = returnRn [] -\end{code} + Nothing -> -- We used it before, but it ain't there now + out_of_date (sep [ptext SLIT("No longer exported:"), ppr name]) -%********************************************************* -%* * -\subsection{Reading an interface file} -%* * -%********************************************************* + 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]) -\begin{code} -findAndReadIface :: SDoc -> ModuleName -> WhereFrom - -> Bool -- Only relevant for SystemImport - -- True <=> Look for a .hi file - -- False <=> Look for .hi-boot file unless there's - -- a library .hi file - -> RnM d (Bool, Maybe (Module, ParsedIface)) - -- Bool is True if the interface actually read was a .hi-boot one - -- Nothing <=> file not found, or unreadable, or illegible - -- Just x <=> successfully found and parsed - -findAndReadIface doc_str mod_name from hi_file - = traceRn trace_msg `thenRn_` - -- we keep two maps for interface files, - -- one for 'normal' ones, the other for .hi-boot files, - -- hence the need to signal which kind we're interested. - - getHiMaps `thenRn` \ hi_maps -> - - case find_path from hi_maps of - -- Found the file - (hi_boot, Just (fpath, mod)) -> traceRn (ptext SLIT("...reading from") <+> text fpath) - `thenRn_` - readIface mod fpath `thenRn` \ result -> - returnRn (hi_boot, result) - (hi_boot, Nothing) -> traceRn (ptext SLIT("...not found")) `thenRn_` - returnRn (hi_boot, Nothing) - where - find_path ImportByUser (hi_map, _) = (False, lookupFM hi_map mod_name) - find_path ImportByUserSource (_, hiboot_map) = (True, lookupFM hiboot_map mod_name) - - find_path ImportBySystem (hi_map, hiboot_map) - | hi_file - = -- If the module we seek is in our dependent set, - -- Look for a .hi file - (False, lookupFM hi_map mod_name) - - | otherwise - -- Check if there's a library module of that name - -- If not, look for an hi-boot file - = case lookupFM hi_map mod_name of - stuff@(Just (_, mod)) | isLibModule mod -> (False, stuff) - other -> (True, lookupFM hiboot_map mod_name) - - trace_msg = sep [hsep [ptext SLIT("Reading"), - ppr from, - ptext SLIT("interface for"), - pprModuleName mod_name <> semi], - nest 4 (ptext SLIT("reason:") <+> doc_str)] +up_to_date msg = traceHiDiffsRn msg `thenRn_` returnRn upToDate +out_of_date msg = traceHiDiffsRn msg `thenRn_` returnRn outOfDate \end{code} -@readIface@ tries just the one file. - -\begin{code} -readIface :: Module -> String -> RnM d (Maybe (Module, ParsedIface)) - -- Nothing <=> file not found, or unreadable, or illegible - -- Just x <=> successfully found and parsed -readIface the_mod file_path - = ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result -> - case read_result of - Right contents -> - case parseIface contents - PState{ bol = 0#, atbol = 1#, - context = [], - glasgow_exts = 1#, - loc = mkSrcLoc (mkFastString file_path) 1 } of - PFailed err -> failWithRn Nothing err - POk _ (PIface mod_nm iface) -> - warnCheckRn (mod_nm == moduleName the_mod) - (hiModuleNameMismatchWarn the_mod mod_nm) `thenRn_` - returnRn (Just (the_mod, iface)) - - Left err - | isDoesNotExistError err -> returnRn Nothing - | otherwise -> failWithRn Nothing (cannaeReadFile file_path err) -\end{code} %********************************************************* %* * @@ -952,44 +796,8 @@ readIface the_mod file_path %********************************************************* \begin{code} -noIfaceErr filename boot_file - = hsep [ptext SLIT("Could not find valid"), boot, - ptext SLIT("interface file"), quotes (pprModule filename)] - where - boot | boot_file = ptext SLIT("[boot]") - | otherwise = empty - -cannaeReadFile file err - = hcat [ptext SLIT("Failed in reading file: "), - text file, - ptext SLIT("; error="), - text (show err)] - getDeclErr name - = ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name) - -getDeclWarn name loc - = sep [ptext SLIT("Failed to find (optional) interface decl for") <+> quotes (ppr name), - ptext SLIT("desired at") <+> ppr loc] - -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)] - -warnRedundantSourceImport mod_name - = ptext SLIT("Unnecessary {- SOURCE -} in the import of module") - <+> quotes (pprModuleName mod_name) - -hiModuleNameMismatchWarn :: Module -> ModuleName -> Message -hiModuleNameMismatchWarn requested_mod mod_nm = - hsep [ ptext SLIT("Something is amiss; requested module name") - , pprModule requested_mod - , ptext SLIT("differs from name found in the interface file ") - , pprModuleName mod_nm - ] - + = vcat [ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name), + ptext SLIT("from module") <+> quotes (ppr (nameModule name)) + ] \end{code}