X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnIfaces.lhs;h=739bb73f0e13fc695a621fd9d2ce643441db8934;hb=8c1b6bd7ffb9ce97da7a72f9e102998df19b23a2;hp=6a24e25e84df430eea3ccfe4d34cf52239b77fb9;hpb=cae34044d89a87bd3da83b0e867b4a5d6994079a;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnIfaces.lhs b/ghc/compiler/rename/RnIfaces.lhs index 6a24e25..739bb73 100644 --- a/ghc/compiler/rename/RnIfaces.lhs +++ b/ghc/compiler/rename/RnIfaces.lhs @@ -1,1179 +1,723 @@ % % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 -% -\section[RnIfaces]{Cacheing and Renaming of Interfaces} +section +\%[RnIfaces]{Cacheing and Renaming of Interfaces} \begin{code} -module RnIfaces ( - findAndReadIface, - - getInterfaceExports, getDeferredDecls, - getImportedInstDecls, getImportedRules, - lookupFixityRn, loadHomeInterface, - importDecl, ImportDeclResult(..), recordLocalSlurps, loadBuiltinRules, - mkImportExportInfo, getSlurped, - - checkModUsage, outOfDate, upToDate, - - getDeclBinders, getDeclSysBinders, - removeContext -- removeContext probably belongs somewhere else - ) where +module RnIfaces + ( slurpImpDecls, importSupportingDecls, + RecompileRequired, outOfDate, upToDate, checkVersions + ) +where #include "HsVersions.h" -import CmdLineOpts ( opt_NoPruneDecls, opt_NoPruneTyDecls, opt_IgnoreIfacePragmas ) -import HsSyn ( HsDecl(..), TyClDecl(..), InstDecl(..), IfaceSig(..), - HsType(..), ConDecl(..), IE(..), ConDetails(..), Sig(..), - ForeignDecl(..), ForKind(..), isDynamicExtName, - FixitySig(..), RuleDecl(..), - isClassOpSig, DeprecDecl(..) +import CmdLineOpts ( opt_IgnoreIfacePragmas, opt_NoPruneDecls ) +import HscTypes +import HsSyn ( HsDecl(..), Sig(..), TyClDecl(..), ConDecl(..), HsConDetails(..), + InstDecl(..), HsType(..), hsTyVarNames, getBangType ) -import HsImpExp ( ieNames ) -import CoreSyn ( CoreRule ) -import BasicTypes ( Version, NewOrData(..) ) -import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameRuleDecl, - RdrNameDeprecation, RdrNameIE, - extractHsTyRdrNames +import RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl ) +import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl, + extractHsTyNames, extractHsCtxtTyNames, + tyClDeclFVs, ruleDeclFVs, impDeclFVs ) -import RnEnv -import RnMonad -import ParseIface ( parseIface, IfaceStuff(..) ) - -import Name ( Name {-instance NamedThing-}, nameOccName, - nameModule, isLocallyDefined, - isWiredInName, nameUnique, NamedThing(..), - elemNameEnv, extendNameEnv +import RnHiFiles ( loadInterface, loadHomeInterface, loadOrphanModules ) +import RnSource ( rnTyClDecl, rnInstDecl, rnIfaceRuleDecl ) +import TcEnv ( getInGlobalScope, tcLookupGlobal_maybe ) +import TcRnMonad +import Id ( idType, idName, globalIdDetails ) +import IdInfo ( GlobalIdDetails(..) ) +import TcType ( tyClsNamesOfType, classNamesOfTheta ) +import FieldLabel ( fieldLabelTyCon ) +import DataCon ( dataConTyCon ) +import TyCon ( visibleDataCons, isSynTyCon, getSynTyConDefn, tyConClass_maybe, tyConName ) +import Class ( className, classSCTheta ) +import Name ( Name {-instance NamedThing-}, isWiredInName, isInternalName, nameModule, NamedThing(..) ) -import Module ( Module, moduleString, pprModule, - mkVanillaModule, pprModuleName, - moduleUserString, moduleName, isLocalModule, - ModuleName, WhereFrom(..), - ) -import RdrName ( RdrName, rdrNameOcc ) +import NameEnv ( delFromNameEnv, lookupNameEnv ) import NameSet -import SrcLoc ( mkSrcLoc, SrcLoc ) -import PrelInfo ( cCallishTyKeys ) -import Maybes ( MaybeErr(..), maybeToBool, orElse ) -import Unique ( Uniquable(..) ) -import StringBuffer ( hGetStringBuffer ) -import FastString ( mkFastString ) -import ErrUtils ( Message ) -import Util ( sortLt ) -import Lex +import Module ( Module, isHomeModule, extendModuleSet ) +import PrelNames ( hasKey, fractionalClassKey, numClassKey, + integerTyConName, doubleTyConName ) import FiniteMap import Outputable import Bag - -import List ( nub ) +import Maybe( fromJust ) \end{code} %********************************************************* -%* * -\subsection{Loading a new interface file} -%* * +%* * +\subsection{Slurping declarations} +%* * %********************************************************* \begin{code} -loadHomeInterface :: SDoc -> Name -> RnM d Ifaces -loadHomeInterface doc_str name - = loadInterface doc_str (moduleName (nameModule name)) ImportBySystem - -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 () - where - load mod = loadInterface (mk_doc mod) mod ImportBySystem - mk_doc mod = pprModuleName mod <+> ptext SLIT("is a orphan-instance module") - - -loadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d Ifaces -loadInterface doc mod from - = tryLoadInterface doc mod from `thenRn` \ (ifaces, maybe_err) -> - case maybe_err of - Nothing -> returnRn ifaces - Just err -> failWithRn ifaces err - -tryLoadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d (Ifaces, Maybe Message) - -- Returns (Just err) if an error happened - -- Guarantees to return with iImpModInfo m --> (... Just cts) - -- (If the load fails, we plug in a vanilla placeholder -tryLoadInterface doc_str mod_name from - = getIfacesRn `thenRn` \ ifaces -> - let - mod_map = iImpModInfo ifaces - mod_info = lookupFM mod_map mod_name - - hi_boot_file = case from of { - ImportByUser -> False ; -- Not hi-boot - ImportByUserSource -> True ; -- hi-boot - ImportBySystem -> - case mod_info of - Just (_, is_boot, _) -> is_boot - - Nothing -> False - -- We're importing a module we know absolutely - -- nothing about, so we assume it's from - -- another package, where we aren't doing - -- dependency tracking. So it won't be a hi-boot file. - } - redundant_source_import - = case (from, mod_info) of - (ImportByUserSource, Just (_,False,_)) -> True - other -> False - in - -- CHECK WHETHER WE HAVE IT ALREADY - case mod_info of { - Just (_, _, Just _) - -> -- We're read it already so don't re-read it - returnRn (ifaces, Nothing) ; - - _ -> - - -- Issue a warning for a redundant {- SOURCE -} import - -- NB that we arrange to read all the ordinary imports before - -- any of the {- SOURCE -} imports - warnCheckRn (not redundant_source_import) - (warnRedundantSourceImport mod_name) `thenRn_` - - -- READ THE MODULE IN - findAndReadIface doc_str mod_name hi_boot_file `thenRn` \ read_result -> - case read_result of { - Left err -> -- 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 (False, False, Just (mod, 0, 0, 0, from, [])) - new_ifaces = ifaces { iImpModInfo = new_mod_map } - in - setIfacesRn new_ifaces `thenRn_` - returnRn (new_ifaces, Just err) ; - - -- Found and parsed! - Right 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 -> - let - mod = pi_mod iface - in - -- Sanity check. If we're system-importing a module we know nothing at all - -- about, it should be from a different package to this one - WARN( not (maybeToBool mod_info) && - case from of { ImportBySystem -> True; other -> False } && - isLocalModule mod, - ppr mod ) - foldlRn (loadDecl mod) (iDecls ifaces) (pi_decls iface) `thenRn` \ new_decls -> - foldlRn (loadInstDecl mod) (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts -> - loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ new_rules -> - loadFixDecls mod_name (iFixes ifaces) (pi_fixity iface) `thenRn` \ new_fixities -> - foldlRn (loadDeprec mod) (iDeprecs ifaces) (pi_deprecs iface) `thenRn` \ new_deprecs -> - mapRn (loadExport this_mod) (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 (pi_usages iface) mod_map - other -> mod_map - - -- Now add info about this module - mod_map2 = addToFM mod_map1 mod_name mod_details - cts = (pi_mod iface, pi_vers iface, - fst (pi_fixity iface), fst (pi_rules iface), - from, concat avails_s) - mod_details = (pi_orphan iface, hi_boot_file, Just cts) - - new_ifaces = ifaces { iImpModInfo = mod_map2, - iDecls = new_decls, - iFixes = new_fixities, - iInsts = new_insts, - iRules = new_rules, - iDeprecs = new_deprecs } - in - setIfacesRn new_ifaces `thenRn_` - returnRn (new_ifaces, Nothing) - }} +------------------------------------------------------- +slurpImpDecls :: FreeVars -> TcRn m [RenamedHsDecl] +slurpImpDecls source_fvs + = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenM_` ------------------------------------------------------ --- Adding module dependencies from the --- import decls in the interface file ------------------------------------------------------ - -addModDeps :: Module -> [ImportVersion a] - -> ImportedModuleInfo -> ImportedModuleInfo --- (addModDeps M ivs deps) --- We are importing module M, and M.hi contains 'import' decls given by ivs -addModDeps mod new_deps mod_deps - = foldr add mod_deps filtered_new_deps - where - -- Don't record dependencies when importing a module from another package - -- Except for its descendents which contain orphans, - -- and in that case, forget about the boot indicator - filtered_new_deps - | isLocalModule mod = [ (imp_mod, (has_orphans, is_boot, Nothing)) - | (imp_mod, has_orphans, is_boot, _) <- new_deps - ] - | otherwise = [ (imp_mod, (True, False, Nothing)) - | (imp_mod, has_orphans, _, _) <- new_deps, - has_orphans - ] - add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep - - combine old@(_, old_is_boot, cts) new - | maybeToBool cts || not old_is_boot = old -- Keep the old info if it's already loaded - -- or if it's a non-boot pending load - | otherwise = new -- Otherwise pick new info - - ------------------------------------------------------ --- Loading the export list ------------------------------------------------------ - -loadExport :: Module -> ExportItem -> RnM d [AvailInfo] -loadExport this_mod (mod, entities) - | mod == moduleName 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! + -- Slurp in things which might be 'gates' for instance + -- declarations, plus the instance declarations themselves + slurpSourceRefs source_fvs `thenM` \ (gate_decls, bndrs) -> - | otherwise - = mapRn (load_entity mod) entities - where - new_name mod occ = newGlobalName 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) - - ------------------------------------------------------ --- Loading type/class/value decls ------------------------------------------------------ + -- Then get everything else + let + needed = foldr (plusFV . impDeclFVs) emptyFVs gate_decls + in + import_supporting_decls (gate_decls, bndrs) needed -loadDecl :: Module - -> DeclsMap - -> (Version, RdrNameHsDecl) - -> RnM d DeclsMap -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 -> +------------------------------------------------------- +slurpSourceRefs :: FreeVars -- Variables referenced in source + -> TcRn m ([RenamedHsDecl], -- Needed declarations + NameSet) -- Names bound by those declarations +-- Slurp imported declarations needed directly by the source code; +-- and some of the ones they need. The goal is to find all the 'gates' +-- for instance declarations. - getDeclSysBinders new_name decl `thenRn` \ sys_bndrs -> - let - full_avail = addSysAvails avail sys_bndrs - -- Add the sys-binders to avail. When we import the decl, - -- it's full_avail that will get added to the 'already-slurped' set (iSlurp) - -- If we miss out sys-binders, we'll read the decl multiple times! - - main_name = availName avail - new_decls_map = foldl add_decl decls_map - [ (name, (version, full_avail, name==main_name, (mod, decl'))) - | name <- availNames full_avail] - add_decl decls_map (name, stuff) - = WARN( name `elemNameEnv` decls_map, ppr name ) - extendNameEnv decls_map name stuff - in - returnRn new_decls_map - } +slurpSourceRefs source_fvs + = go_outer [] emptyFVs -- Accumulating decls + (nameSetToList source_fvs) -- Things whose defn hasn't been loaded yet where - -- newTopBinder 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. - -- There maybe occurrences that don't have the correct Module, but - -- by the typechecker will propagate the binding definition to all - -- the occurrences, so that doesn't matter - new_name rdr_name loc = newTopBinder mod (rdrNameOcc 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 - ------------------------------------------------------ --- Loading fixity decls ------------------------------------------------------ - -loadFixDecls mod_name fixity_env (version, decls) - | null decls = returnRn fixity_env + -- The outer loop repeatedly slurps the decls for the current gates + -- and the instance decls - | otherwise - = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add -> - returnRn (extendNameEnvList fixity_env to_add) - -loadFixDecl mod_name sig@(FixitySig rdr_name fixity loc) - = newGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name -> - returnRn (name, FixitySig name fixity loc) - - ------------------------------------------------------ --- Loading instance decls ------------------------------------------------------ - -loadInstDecl :: Module - -> IfaceInsts - -> RdrNameInstDecl - -> RnM d IfaceInsts -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 ... + -- The outer loop is needed because consider + -- instance Foo a => Baz (Maybe a) where ... + -- It may be that Baz and Maybe are used in the source module, + -- but not Foo; so we need to chase Foo too. -- - -- Here the gates are Baz and T, but *not* Foo. - let - munged_inst_ty = removeContext inst_ty - free_names = extractHsTyRdrNames munged_inst_ty - in - setModuleRn mod $ - mapRn lookupOrigName 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 (HsFunTy _ ty) = removeFuns ty -removeFuns ty = ty + -- We also need to follow superclass refs. In particular, 'chasing Foo' must + -- include actually getting in Foo's class decl + -- class Wib a => Foo a where .. + -- so that its superclasses are discovered. The point is that Wib is a gate too. + -- We do this for tycons too, so that we look through type synonyms. + + go_outer decls bndrs [] = returnM (decls, bndrs) + + go_outer decls bndrs refs -- 'refs' are not necessarily slurped yet + = traceRn (text "go_outer" <+> ppr refs) `thenM_` + foldlM go_inner (decls, bndrs, emptyFVs) refs `thenM` \ (decls1, bndrs1, gates1) -> + getImportedInstDecls gates1 `thenM` \ (inst_decls, new_gates) -> + rnIfaceDecls rnInstDecl inst_decls `thenM` \ inst_decls' -> + go_outer (map InstD inst_decls' ++ decls1) + bndrs1 + (nameSetToList (new_gates `plusFV` plusFVs (map getInstDeclGates inst_decls'))) + -- NB: we go round again to fetch the decls for any gates of any decls + -- we have loaded. For example, if we mention + -- print :: Show a => a -> String + -- then we must load the decl for Show before stopping, to ensure + -- that instances from its home module are available + + go_inner (decls, bndrs, gates) wanted_name + = importDecl bndrs wanted_name `thenM` \ import_result -> + case import_result of + AlreadySlurped -> returnM (decls, bndrs, gates) + + InTypeEnv ty_thing + -> returnM (decls, + bndrs `addOneFV` wanted_name, -- Avoid repeated calls to getWiredInGates + gates `plusFV` getWiredInGates ty_thing) + + HereItIs decl new_bndrs + -> rnIfaceDecl rnTyClDecl decl `thenM` \ new_decl -> + returnM (TyClD new_decl : decls, + bndrs `plusFV` new_bndrs, + gates `plusFV` getGates source_fvs new_decl) +\end{code} +\begin{code} +------------------------------------------------------- +-- import_supporting_decls keeps going until the free-var set is empty +importSupportingDecls needed + = import_supporting_decls ([], emptyNameSet) needed + +import_supporting_decls + :: ([RenamedHsDecl], NameSet) -- Some imported decls, with their binders + -> FreeVars -- Remaining un-slurped names + -> TcRn m [RenamedHsDecl] +import_supporting_decls decls needed + = slurpIfaceDecls decls needed `thenM` \ (decls1, bndrs1) -> + getImportedRules bndrs1 `thenM` \ rule_decls -> + case rule_decls of + [] -> returnM decls1 -- No new rules, so we are done + other -> rnIfaceDecls rnIfaceRuleDecl rule_decls `thenM` \ rule_decls' -> + let + rule_fvs = plusFVs (map ruleDeclFVs rule_decls') + decls2 = decls1 ++ map RuleD rule_decls' + in + traceRn (text "closeRules" <+> ppr rule_decls' $$ + fsep (map ppr (nameSetToList rule_fvs))) `thenM_` + import_supporting_decls (decls2, bndrs1) rule_fvs + + +------------------------------------------------------- +-- Augment decls with any decls needed by needed, +-- and so on transitively +slurpIfaceDecls :: ([RenamedHsDecl], NameSet) -- Already slurped + -> FreeVars -- Still needed + -> TcRn m ([RenamedHsDecl], NameSet) +slurpIfaceDecls (decls, bndrs) needed + = slurp decls bndrs (nameSetToList needed) + where + slurp decls bndrs [] = returnM (decls, bndrs) + slurp decls bndrs (n:ns) + = importDecl bndrs n `thenM` \ import_result -> + case import_result of + HereItIs decl new_bndrs -- Found a declaration... rename it + -> rnIfaceDecl rnTyClDecl decl `thenM` \ new_decl -> + slurp (TyClD new_decl : decls) + (bndrs `plusFV` new_bndrs) + (nameSetToList (tyClDeclFVs new_decl) ++ ns) + + + other -> -- No declaration... (wired in thing, or deferred, + -- or already slurped) + slurp decls (bndrs `addOneFV` n) ns + +------------------------------------------------------- +rnIfaceDecls rn decls = mappM (rnIfaceDecl rn) decls +rnIfaceDecl rn (mod, decl) = initRn (InterfaceMode mod) (rn decl) +\end{code} ------------------------------------------------------ --- Loading Rules ------------------------------------------------------ -loadRules :: Module -> IfaceRules - -> (Version, [RdrNameRuleDecl]) - -> RnM d IfaceRules -loadRules mod rule_bag (version, rules) - | null rules || opt_IgnoreIfacePragmas - = returnRn rule_bag - | otherwise - = setModuleRn mod $ - mapRn (loadRule mod) rules `thenRn` \ new_rules -> - returnRn (rule_bag `unionBags` listToBag new_rules) - -loadRule :: Module -> RdrNameRuleDecl -> RnM d GatedDecl --- "Gate" the rule simply by whether the rule variable is --- needed. We can refine this later. -loadRule mod decl@(IfaceRule _ _ var _ _ src_loc) - = lookupOrigName var `thenRn` \ var_name -> - returnRn (unitNameSet var_name, (mod, RuleD decl)) - -loadBuiltinRules :: [(RdrName, CoreRule)] -> RnMG () -loadBuiltinRules builtin_rules - = getIfacesRn `thenRn` \ ifaces -> - mapRn loadBuiltinRule builtin_rules `thenRn` \ rule_decls -> - setIfacesRn (ifaces { iRules = iRules ifaces `unionBags` listToBag rule_decls }) - -loadBuiltinRule (var, rule) - = lookupOrigName var `thenRn` \ var_name -> - returnRn (unitNameSet var_name, (nameModule var_name, RuleD (IfaceRuleOut var rule))) - - ------------------------------------------------------ --- Loading Deprecations ------------------------------------------------------ - -loadDeprec :: Module -> DeprecationEnv -> RdrNameDeprecation -> RnM d DeprecationEnv -loadDeprec mod deprec_env (Deprecation (IEModuleContents _) txt _) - = traceRn (text "module deprecation not yet implemented:" <+> ppr mod <> colon <+> ppr txt) `thenRn_` - -- SUP: TEMPORARY HACK, ignoring module deprecations for now - returnRn deprec_env - -loadDeprec mod deprec_env (Deprecation ie txt _) - = setModuleRn mod $ - mapRn lookupOrigName (ieNames ie) `thenRn` \ names -> - traceRn (text "loaded deprecation(s) for" <+> hcat (punctuate comma (map ppr names)) <> colon <+> ppr txt) `thenRn_` - returnRn (extendNameEnvList deprec_env (zip names (repeat txt))) +\begin{code} + -- Tiresomely, we must get the "main" name for the + -- thing, because that's what VSlurp contains, and what + -- is recorded in the usage information +get_main_name (AClass cl) = className cl +get_main_name (ATyCon tc) + | Just clas <- tyConClass_maybe tc = get_main_name (AClass clas) + | otherwise = tyConName tc +get_main_name (AnId id) + = case globalIdDetails id of + DataConId dc -> get_main_name (ATyCon (dataConTyCon dc)) + DataConWrapId dc -> get_main_name (ATyCon (dataConTyCon dc)) + RecordSelId lbl -> get_main_name (ATyCon (fieldLabelTyCon lbl)) + other -> idName id + + +recordUsage :: Name -> TcRn m () +-- Record that the Name has been used, for +-- later generation of usage info in the interface file +recordUsage name = updUsages (upd_usg name) + +upd_usg name usages + | isHomeModule mod = usages { usg_home = addOneToNameSet (usg_home usages) name } + | otherwise = usages { usg_ext = extendModuleSet (usg_ext usages) mod } + where + mod = nameModule name \end{code} -%******************************************************** +%********************************************************* %* * -\subsection{Checking usage information} +\subsection{Getting in a declaration} %* * -%******************************************************** +%********************************************************* \begin{code} -upToDate = True -outOfDate = False +importDecl :: NameSet -> Name -> TcRn m ImportDeclResult -checkModUsage :: [ImportVersion OccName] -> RnMG Bool --- Given the usage information extracted from the old --- M.hi file for the module being compiled, figure out --- whether M needs to be recompiled. +data ImportDeclResult + = AlreadySlurped + | InTypeEnv TyThing + | HereItIs (Module, RdrNameTyClDecl) NameSet + -- The NameSet is the bunch of names bound by this decl + +importDecl already_slurped name + = -- STEP 0: Check if it's from this module + -- Doing this catches a common case quickly + getModule `thenM` \ this_mod -> + if isInternalName name || nameModule name == this_mod then + -- Variables defined on the GHCi command line (e.g. let x = 3) + -- are Internal names (which don't have a Module) + returnM AlreadySlurped + else -checkModUsage [] = returnRn upToDate -- Yes! Everything is up to date! + -- STEP 1: Check if we've slurped it in while compiling this module + if name `elemNameSet` already_slurped then + returnM AlreadySlurped + else -checkModUsage ((mod_name, _, _, NothingAtAll) : rest) - -- 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. - = traceRn (ptext SLIT("Nothing used from:") <+> ppr mod_name) `thenRn_` - checkModUsage rest -- This one's ok, so check the rest - -checkModUsage ((mod_name, _, _, whats_imported) : rest) - = tryLoadInterface doc_str mod_name ImportBySystem `thenRn` \ (ifaces, maybe_err) -> - case maybe_err of { - Just err -> out_of_date (sep [ptext SLIT("Can't find version number for module"), - pprModuleName 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 + -- STEP 2: Check if it's already in the type environment + tcLookupGlobal_maybe name `thenM` \ maybe_thing -> + case maybe_thing of { + + Just ty_thing + | isWiredInName name + -> -- 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 `thenM_` + returnM (InTypeEnv ty_thing) + + | otherwise + -> -- We have slurp something that's already in the type environment, + -- that was not slurped in an earlier compilation. + -- Must still record it in the Usages info, because that's used to + -- generate usage information + + traceRn (text "not wired in" <+> ppr name) `thenM_` + recordUsage (get_main_name ty_thing) `thenM_` + returnM (InTypeEnv ty_thing) ; Nothing -> + + -- STEP 4: OK, we have to slurp it in from an interface file + -- First load the interface file + traceRn nd_doc `thenM_` + loadHomeInterface nd_doc name `thenM_` + + -- STEP 4: Get the declaration out + getEps `thenM` \ eps -> let - (_, new_mod_vers, new_fix_vers, new_rule_vers, _, _) - = case lookupFM (iImpModInfo ifaces) mod_name of - Just (_, _, Just stuff) -> stuff - - old_mod_vers = case whats_imported of - Everything v -> v - Specifically v _ _ _ -> v - -- NothingAtAll case dealt with by previous eqn for checkModUsage + (decls_map, n_slurped) = eps_decls eps in - -- 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 + case lookupNameEnv decls_map name of + Just (avail,_,decl) -> setEps eps' `thenM_` + recordUsage (availName avail) `thenM_` + returnM (HereItIs decl (mkFVs avail_names)) + where + avail_names = availNames avail + new_decls_map = foldl delFromNameEnv decls_map avail_names + eps' = eps { eps_decls = (new_decls_map, n_slurped+1) } - -- 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 { -- NothingAtAll dealt with earlier - - Everything _ - -> out_of_date (ptext SLIT("...and I needed the whole module")) ; - - Specifically _ old_fix_vers old_rule_vers old_local_vers -> - - if old_fix_vers /= new_fix_vers then - out_of_date (ptext SLIT("Fixities changed")) - else if old_rule_vers /= new_rule_vers then - out_of_date (ptext SLIT("Rules changed")) - else - -- 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 outOfDate -- This one failed, so just bail out now - }} + Nothing -> addErr (getDeclErr name) `thenM_` + returnM AlreadySlurped + } where - doc_str = sep [ptext SLIT("need version info for"), pprModuleName mod_name] + wi_doc = ptext SLIT("need home module for wired in thing") <+> ppr name + nd_doc = ptext SLIT("need decl for") <+> ppr name + +\end{code} -checkEntityUsage mod decls [] - = returnRn upToDate -- Yes! All up to date! +%********************************************************* +%* * +\subsection{Extracting the `gates'} +%* * +%********************************************************* -checkEntityUsage mod decls ((occ_name,old_vers) : rest) - = newGlobalName mod occ_name `thenRn` \ name -> - case lookupNameEnv decls name of +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. + +More precisely, the gates of a module are the types and classes +that are mentioned in: + + a) the source code [Note: in fact these don't seem + to be treated as gates, perhaps + because no imported instance decl + can mention them; mutter mutter + recursive modules.] + 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 the gates of a previously-loaded module - Nothing -> -- We used it before, but it ain't there now - out_of_date (sep [ptext SLIT("No longer exported:"), ppr name]) +The latter constraint is because there might have been an instance +decl slurped in during an earlier compilation, like this: - 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 + instance Foo a => Baz (Maybe a) where ... - | otherwise - -- Out of date, so bale out - -> out_of_date (sep [ptext SLIT("Out of date:"), ppr name]) +In the module being compiled we might need (Baz (Maybe T)), where T is +defined in this module, and hence we need the instance for (Foo T). +So @Foo@ becomes a gate. But there's no way to 'see' that. More +generally, types might be involved as well: -out_of_date msg = traceRn msg `thenRn_` returnRn outOfDate -\end{code} + instance Foo2 S a => Baz2 a where ... +Now we must treat S as a gate too, as well as Foo2. So the solution +we adopt is: -%********************************************************* -%* * -\subsection{Getting in a declaration} -%* * -%********************************************************* + we simply treat the gates of all previously-loaded + modules as gates of this one -\begin{code} -importDecl :: Name -> RnMG ImportDeclResult +So the gates are remembered across invocations of the renamer in the +PersistentRenamerState. This gloss mainly affects ghc --make and ghc +--interactive. -data ImportDeclResult - = AlreadySlurped - | WiredIn - | Deferred - | HereItIs (Module, RdrNameHsDecl) - -importDecl name - = getSlurped `thenRn` \ already_slurped -> - if name `elemNameSet` already_slurped then - returnRn AlreadySlurped -- 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 AlreadySlurped - - else if isWiredInName name then - -- When we find a wired-in name we must load its - -- home module so that we find any instance decls therein - loadHomeInterface doc name `thenRn_` - returnRn WiredIn - - else getNonWiredInDecl name - where - doc = ptext SLIT("need home module for wired in thing") <+> ppr name - - -{- I don't think this is necessary any more; SLPJ May 00 - load_home name - | name `elemNameSet` source_binders = returnRn () - -- When compiling the prelude, a wired-in thing may - -- be defined in this module, in which case we don't - -- want to load its home module! - -- Using 'isLocallyDefined' doesn't work because some of - -- the free variables returned are simply 'listTyCon_Name', - -- with a system provenance. We could look them up every time - -- but that seems a waste. - | otherwise = loadHomeInterface doc name `thenRn_` - returnRn () --} - -getNonWiredInDecl :: Name -> RnMG ImportDeclResult -getNonWiredInDecl needed_name - = traceRn doc_str `thenRn_` - loadHomeInterface doc_str needed_name `thenRn` \ ifaces -> - case lookupNameEnv (iDecls ifaces) needed_name of - - Just (version, avail, is_tycon_name, decl@(_, TyClD (TyData DataType _ _ _ _ ncons _ _ _))) - -- This case deals with deferred import of algebraic data types - - | not opt_NoPruneTyDecls - - && (opt_IgnoreIfacePragmas || ncons > 1) - -- We only defer if imported interface pragmas are ingored - -- or if it's not a product type. - -- Sole reason: The wrapper for a strict function may need to look - -- inside its arg, and hence need to see its arg type's constructors. - - && not (getUnique tycon_name `elem` cCallishTyKeys) - -- Never defer ccall types; we have to unbox them, - -- and importing them does no harm - - -> -- OK, so we're importing a deferrable data type - if needed_name == tycon_name then - -- The needed_name is the TyCon of a data type decl - -- Record that it's slurped, put it in the deferred set - -- and don't return a declaration at all - setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces - `addOneToNameSet` tycon_name}) - version (AvailTC needed_name [needed_name])) `thenRn_` - returnRn Deferred - else - -- The needed name is a constructor of a data type decl, - -- getting a constructor, so remove the TyCon from the deferred set - -- (if it's there) and return the full declaration - setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces - `delFromNameSet` tycon_name}) - version avail) `thenRn_` - returnRn (HereItIs decl) - where - tycon_name = availName avail +(We used to use the persistent type environment for this purpose, +but it has too much. For a start, it contains all tuple types, +because they are in the wired-in type env!) - Just (version,avail,_,decl) - -> setIfacesRn (recordSlurp ifaces version avail) `thenRn_` - returnRn (HereItIs decl) - Nothing - -> addErrRn (getDeclErr needed_name) `thenRn_` - returnRn AlreadySlurped - where - doc_str = ptext SLIT("need decl for") <+> ppr needed_name +Consructors and class operations +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +When we import a declaration like -getDeferredDecls :: RnMG [(Module, RdrNameHsDecl)] -getDeferredDecls - = getIfacesRn `thenRn` \ ifaces -> - let - decls_map = iDecls ifaces - deferred_names = nameSetToList (iDeferred ifaces) - get_abstract_decl n = case lookupNameEnv decls_map n of - Just (_, _, _, decl) -> decl - in - traceRn (sep [text "getDeferredDecls", nest 4 (fsep (map ppr deferred_names))]) `thenRn_` - returnRn (map get_abstract_decl deferred_names) -\end{code} + data T = T1 Wibble | T2 Wobble -@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. +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. -\item similarly for synonum type constructor +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 + -- Used for the cunning "constructors and + -- class ops" story described 10 lines above. + -> RenamedTyClDecl + -> FreeVars -\item if the wired-in name is another wired-in Id, it marks as ``occurrences'' - the free vars of the Id's type. +getGates source_fvs decl + = get_gates (\n -> n `elemNameSet` source_fvs) decl -\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. +get_gates is_used (ForeignType {tcdName = tycon}) = unitNameSet tycon +get_gates is_used (IfaceSig {tcdType = ty}) = extractHsTyNames ty + +get_gates is_used (ClassDecl { tcdCtxt = ctxt, tcdName = cls, tcdTyVars = tvs, tcdSigs = sigs}) + = (super_cls_and_sigs `addOneToNameSet` cls) `unionNameSets` + implicitClassGates cls + where + super_cls_and_sigs = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) sigs) + (hsTyVarNames tvs) + get (ClassOpSig n _ ty _) + | is_used n = extractHsTyNames ty + | 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) + (visibleDataCons 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 (PrefixCon 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] - -%********************************************************* -%* * -\subsection{Getting what a module exports} -%* * -%********************************************************* + get_field (f,t) | is_used f = get_bang t + | otherwise = emptyFVs -@getInterfaceExports@ is called only for directly-imported modules. + get_bang bty = extractHsTyNames (getBangType bty) + +implicitClassGates :: Name -> FreeVars +implicitClassGates cls + -- If we load class Num, add Integer to the free gates + -- This takes account of the fact that Integer might be needed for + -- defaulting, but we don't want to load Integer (and all its baggage) + -- if there's no numeric stuff needed. + -- Similarly for class Fractional and Double + -- + -- NB: adding T to the gates will force T to be loaded + -- + -- NB: If we load (say) Floating, we'll end up loading Fractional too, + -- since Fractional is a superclass of Floating + | cls `hasKey` numClassKey = unitFV integerTyConName + | cls `hasKey` fractionalClassKey = unitFV doubleTyConName + | otherwise = emptyFVs +\end{code} + +@getWiredInGates@ is just like @getGates@, but it sees a previously-loaded +thing rather than a declaration. \begin{code} -getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, Avails) -getInterfaceExports mod_name from - = loadInterface doc_str mod_name from `thenRn` \ ifaces -> - case lookupFM (iImpModInfo ifaces) mod_name of - Just (_, _, Just (mod, _, _, _, _, avails)) -> returnRn (mod, avails) - -- loadInterface always puts something in the map - -- even if it's a fake +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 (AClass cl) + = unitFV (getName cl) `plusFV` mkFVs super_classes where - doc_str = sep [pprModuleName mod_name, ptext SLIT("is directly imported")] -\end{code} + super_classes = classNamesOfTheta (classSCTheta cl) +getWiredInGates (AnId the_id) = tyClsNamesOfType (idType the_id) +getWiredInGates (ATyCon tc) + | isSynTyCon tc = tyClsNamesOfType ty + | otherwise = unitFV (getName tc) + where + (_,ty) = getSynTyConDefn tc -%********************************************************* -%* * -\subsection{Instance declarations are handled specially} -%* * -%********************************************************* +getInstDeclGates (InstDecl inst_ty _ _ _ _) = extractHsTyNames inst_ty +\end{code} \begin{code} -getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)] +getImportedInstDecls :: NameSet -> TcRn m ([(Module,RdrNameInstDecl)], NameSet) + -- Returns the gates that are new since last time 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 -> + getEps `thenM` \ eps -> let - orphan_mods = - [mod | (mod, (True, _, Nothing)) <- fmToList (iImpModInfo ifaces)] + old_gates = eps_inst_gates eps + new_gates = gates `minusNameSet` old_gates + all_gates = new_gates `unionNameSets` old_gates + orphan_mods = [mod | (mod, (True, _)) <- fmToList (eps_imp_mods eps)] in - loadOrphanModules orphan_mods `thenRn_` + loadOrphanModules orphan_mods `thenM_` -- 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 -> + -- removing them from the bag kept in EPS + -- Don't foget to get the EPS a second time... + -- loadOrphanModules may have side-effected it! + getEps `thenM` \ eps -> let - (decls, new_insts) = selectGated gates (iInsts ifaces) + available n = n `elemNameSet` all_gates + (decls, new_insts) = selectGated available (eps_insts eps) in - setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_` + setEps (eps { eps_insts = new_insts, + eps_inst_gates = all_gates }) `thenM_` traceRn (sep [text "getImportedInstDecls:", - nest 4 (fsep (map ppr gate_list)), + nest 4 (fsep (map ppr (nameSetToList gates))), + nest 4 (fsep (map ppr (nameSetToList all_gates))), + nest 4 (fsep (map ppr (nameSetToList new_gates))), text "Slurped" <+> int (length decls) <+> text "instance declarations", - nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_` - returnRn decls - where - gate_list = nameSetToList gates + nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenM_` + returnM (decls, new_gates) -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 - | opt_IgnoreIfacePragmas = returnRn [] +getImportedRules :: NameSet -- Slurped already + -> TcRn m [(Module,RdrNameRuleDecl)] +getImportedRules slurped + | opt_IgnoreIfacePragmas = returnM [] | otherwise - = getIfacesRn `thenRn` \ ifaces -> + = getEps `thenM` \ eps -> + getInGlobalScope `thenM` \ in_type_env -> let - gates = iSlurp ifaces -- Anything at all that's been slurped - rules = iRules ifaces - (decls, new_rules) = selectGated gates rules + -- Slurp rules for anything that is slurped, + -- either now, or previously + available n = n `elemNameSet` slurped || in_type_env n + (decls, new_rules) = selectGated available (eps_rules eps) in if null decls then - returnRn [] + returnM [] else - setIfacesRn (ifaces { iRules = new_rules }) `thenRn_` + setEps (eps { eps_rules = new_rules }) `thenM_` traceRn (sep [text "getImportedRules:", - text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_` - returnRn decls + text "Slurped" <+> int (length decls) <+> text "rules"]) `thenM_` + returnM decls -selectGated gates decl_bag - -- Select only those decls whose gates are *all* in 'gates' +selectGated :: (Name->Bool) -> GatedDecls d + -> ([(Module,d)], GatedDecls d) +selectGated available (decl_bag, n_slurped) + -- Select only those decls whose gates are *all* available #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 - select (reqd, decl) (yes, no) - | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no) - | otherwise = (yes, (reqd,decl) `consBag` no) - -lookupFixityRn :: Name -> RnMS Fixity -lookupFixityRn name - | isLocallyDefined name - = getFixityEnv `thenRn` \ local_fix_env -> - returnRn (lookupFixity local_fix_env name) - - | otherwise -- Imported - -- For imported names, we have to get their fixities by doing a loadHomeInterface, - -- and consulting the Ifaces that comes back from that, because the interface - -- file for the Name might not have been loaded yet. Why not? Suppose you import module A, - -- which exports a function 'f', which is defined in module B. Then B isn't loaded - -- right away (after all, it's possible that nothing from B will be used). - -- When we come across a use of 'f', we need to know its fixity, and it's then, - -- and only then, that we load B.hi. That is what's happening here. - = loadHomeInterface doc name `thenRn` \ ifaces -> - returnRn (lookupFixity (iFixes ifaces) name) - where - doc = ptext SLIT("Checking fixity for") <+> ppr name + select (gate_fn, decl) (yes, no) + | gate_fn available = (decl:yes, no) + | otherwise = (yes, (gate_fn,decl) `consBag` no) \end{code} -%********************************************************* +%******************************************************** %* * -\subsection{Keeping track of what we've slurped, and version numbers} +\subsection{Checking usage information} %* * -%********************************************************* +%******************************************************** -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 (a) anything reachable from its body code -\item (b) any module exported with a @module Foo@ -\item (c) anything reachable from an exported item -\end{itemize} - -Why (b)? Because if @Foo@ changes then this module's export list -will change, so we must recompile this module at least as far as -making a new interface file --- but in practice that means complete -recompilation. - -Why (c)? Consider this: -\begin{verbatim} - module A( f, g ) where | module B( f ) where - import B( f ) | f = h 3 - g = ... | h = ... -\end{verbatim} - -Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in -@A@'s usages? Our idea is that we aren't going to touch A.hi if it is -*identical* to what it was before. If anything about @B.f@ changes -than anyone who imports @A@ should be recompiled in case they use -@B.f@ (they'll get an early exit if they don't). So, if anything -about @B.f@ changes we'd better make sure that something in A.hi -changes, and the convenient way to do that is to record the version -number @B.f@ in A.hi in the usage list. If B.f changes that'll force a -complete recompiation of A, which is overkill but it's the only way to -write a new, slightly different, A.hi. - -But the example is tricker. Even if @B.f@ doesn't change at all, -@B.h@ may do so, and this change may not be reflected in @f@'s version -number. But with -O, a module that imports A must be recompiled if -@B.h@ changes! So A must record a dependency on @B.h@. So we treat -the occurrence of @B.f@ in the export list *just as if* it were in the -code of A, and thereby haul in all the stuff reachable from it. - -[NB: If B was compiled with -O, but A isn't, we should really *still* -haul in all the unfoldings for B, in case the module that imports A *is* -compiled with -O. I think this is the case.] - -Even if B is used at all we get a usage line for B - import B :: ... ; -in A.hi, to record the fact that A does import B. This is used to decide -to look to look for B.hi rather than B.hi-boot when compiling a module that -imports A. This line says that A imports B, but uses nothing in it. -So we'll get an early bale-out when compiling A if B's version changes. +@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} -mkImportExportInfo :: ModuleName -- Name of this module - -> Avails -- Info about exports - -> Maybe [RdrNameIE] -- The export header - -> RnMG ([ExportItem], -- Export info for iface file; sorted - [ImportVersion OccName]) -- Import info for iface file; sorted - -- Both results are sorted into canonical order to - -- reduce needless wobbling of interface files - -mkImportExportInfo this_mod export_avails exports - = getIfacesRn `thenRn` \ ifaces -> - let - export_all_mods = case exports of - Nothing -> [] - Just es -> [mod | IEModuleContents mod <- es, - mod /= this_mod] - - mod_map = iImpModInfo ifaces - imp_names = iVSlurp ifaces - - -- mv_map groups together all the things imported from a particular module. - mv_map :: FiniteMap ModuleName [(OccName,Version)] - mv_map = foldr add_mv emptyFM imp_names - - add_mv (name, version) mv_map = addItem mv_map (moduleName (nameModule name)) - (nameOccName name, version) - - -- Build the result list by adding info for each module. - -- For (a) a library module, we don't record it at all unless it contains orphans - -- (We must never lose track of orphans.) - -- - -- (b) a source-imported module, don't record the dependency at all - -- - -- (b) may seem a bit strange. The idea is that the usages in a .hi file records - -- *all* the module's dependencies other than the loop-breakers. We use - -- this info in findAndReadInterface to decide whether to look for a .hi file or - -- a .hi-boot file. - -- - -- This means we won't track version changes, or orphans, from .hi-boot files. - -- The former is potentially rather bad news. It could be fixed by recording - -- whether something is a boot file along with the usage info for it, but - -- I can't be bothered just now. - - mk_imp_info mod_name (has_orphans, is_boot, contents) so_far - | mod_name == this_mod -- Check if M appears in the set of modules 'below' M - -- This seems like a convenient place to check - = WARN( not is_boot, ptext SLIT("Wierd:") <+> ppr this_mod <+> - ptext SLIT("imports itself (perhaps indirectly)") ) - so_far - - | otherwise - = let - go_for_it exports = (mod_name, has_orphans, is_boot, exports) - : so_far - in - case contents of - Nothing -> -- We didn't even open the interface - -- This happens when a module, Foo, that we explicitly imported has - -- 'import Baz' in its interface file, recording that Baz is below - -- Foo in the module dependency hierarchy. We want to propagate this - -- information. The Nothing says that we didn't even open the interface - -- file but we must still propagate the dependeny info. - -- The module in question must be a local module (in the same package) - go_for_it NothingAtAll - - Just (mod, mod_vers, fix_vers, rule_vers, how_imported, _) - | is_sys_import && is_lib_module && not has_orphans - -> so_far - - | is_lib_module -- Record the module but not detailed - || mod_name `elem` export_all_mods -- version information for the imports - -> go_for_it (Everything mod_vers) - - | otherwise - -> case lookupFM mv_map mod_name of - Just whats_imported -> go_for_it (Specifically mod_vers fix_vers rule_vers - (sortImport whats_imported)) - Nothing -> go_for_it NothingAtAll - -- This happens if you have - -- import Foo - -- but don't actually *use* anything from Foo - -- In which case record an empty dependency list - where - is_lib_module = not (isLocalModule mod) - is_sys_import = case how_imported of - ImportBySystem -> True - other -> False - - - import_info = foldFM mk_imp_info [] mod_map - - -- Sort exports into groups by module - export_fm :: FiniteMap ModuleName [RdrAvailInfo] - export_fm = foldr insert emptyFM export_avails - - insert avail efm = addItem efm (moduleName (nameModule (availName avail))) - (rdrAvailInfo avail) - - export_info = [(m, sortExport as) | (m,as) <- fmToList export_fm] - in - returnRn (export_info, import_info) - - -addItem :: FiniteMap ModuleName [a] -> ModuleName -> a -> FiniteMap ModuleName [a] -addItem fm mod x = addToFM_C add_item fm mod [x] - where - add_item xs _ = x:xs - -sortImport :: [(OccName,Version)] -> [(OccName,Version)] - -- Make the usage lists appear in canonical order -sortImport vs = sortLt lt vs - where - lt (n1,v1) (n2,v2) = n1 < n2 - -sortExport :: [RdrAvailInfo] -> [RdrAvailInfo] -sortExport as = sortLt lt as - where - lt a1 a2 = availName a1 < availName a2 +type RecompileRequired = Bool +upToDate = False -- Recompile not required +outOfDate = True -- Recompile required + +checkVersions :: Bool -- True <=> source unchanged + -> ModIface -- Old interface + -> TcRn m RecompileRequired +checkVersions source_unchanged iface + | not source_unchanged + = returnM outOfDate + | otherwise + = traceHiDiffs (text "Considering whether compilation is required for" <+> + ppr (mi_module iface) <> colon) `thenM_` + + -- Source code unchanged and no errors yet... carry on + checkList [checkModUsage u | u <- mi_usages iface] + +checkList :: [TcRn m RecompileRequired] -> TcRn m RecompileRequired +checkList [] = returnM upToDate +checkList (check:checks) = check `thenM` \ recompile -> + if recompile then + returnM outOfDate + else + checkList checks \end{code} - + \begin{code} -getSlurped - = getIfacesRn `thenRn` \ ifaces -> - returnRn (iSlurp ifaces) +checkModUsage :: ImportVersion Name -> TcRn m 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. -recordSlurp ifaces@(Ifaces { iSlurp = slurped_names, iVSlurp = imp_names }) - version avail - = let - new_slurped_names = addAvailToNameSet slurped_names avail - new_imp_names = (availName avail, version) : imp_names - in - ifaces { iSlurp = new_slurped_names, iVSlurp = new_imp_names } +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) -recordLocalSlurps local_avails - = getIfacesRn `thenRn` \ ifaces -> +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) let - new_slurped_names = foldl addAvailToNameSet (iSlurp ifaces) local_avails + doc_str = sep [ptext SLIT("need version info for"), ppr mod_name] + from = ImportForUsage is_boot in - setIfacesRn (ifaces { iSlurp = new_slurped_names }) -\end{code} - + traceHiDiffs (text "Checking usages for module" <+> ppr mod_name) `thenM_` -%********************************************************* -%* * -\subsection{Getting binders out of a declaration} -%* * -%********************************************************* + tryM (loadInterface doc_str mod_name from) `thenM` \ mb_iface -> -@getDeclBinders@ returns the names for a @RdrNameHsDecl@. -It's used for both source code (from @availsFromDecl@) and interface files -(from @loadDecl@). - -It doesn't deal with source-code specific things: @ValD@, @DefD@. They -are handled by the sourc-code specific stuff in @RnNames@. - -\begin{code} -getDeclBinders :: (RdrName -> SrcLoc -> 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])) - -getDeclBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ _ _ _ _ src_loc)) - = new_name cname src_loc `thenRn` \ class_name -> + case mb_iface of { + Left exn -> (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 - -- Record the names for the class ops + Right iface -> let - -- just want class-op sigs - op_sigs = filter isClassOpSig sigs + new_vers = mi_version iface + new_mod_vers = vers_module new_vers + new_decl_vers = vers_decls new_vers + new_export_vers = vers_exports new_vers + new_rule_vers = vers_rules new_vers in - mapRn (getClassOpNames new_name) op_sigs `thenRn` \ sub_names -> - - returnRn (Just (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 (Just (Avail var_name)) - -getDeclBinders new_name (FixD _) = returnRn Nothing -getDeclBinders new_name (DeprecD _) = returnRn Nothing - - -- 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)) - - | otherwise -- a foreign export - = lookupOrigName nm `thenRn_` - returnRn Nothing - -getDeclBinders new_name (DefD _) = returnRn Nothing -getDeclBinders new_name (InstD _) = returnRn Nothing -getDeclBinders new_name (RuleD _) = returnRn Nothing + case whats_imported of { -- NothingAtAll dealt with earlier -binds_haskell_name (FoImport _) _ = True -binds_haskell_name FoLabel _ = True -binds_haskell_name FoExport ext_nm = isDynamicExtName ext_nm + Everything old_mod_vers -> checkModuleVersion old_mod_vers new_mod_vers `thenM` \ recompile -> + if recompile then + out_of_date (ptext SLIT("...and I needed the whole module")) + else + returnM upToDate ; ----------------- -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) + Specifically old_mod_vers maybe_old_export_vers old_decl_vers old_rule_vers -> -getConFieldNames new_name (ConDecl con _ _ _ condecl src_loc : rest) - = new_name con src_loc `thenRn` \ n -> - getConFieldNames new_name rest `thenRn` \ ns -> - returnRn (n : ns) + -- CHECK MODULE + checkModuleVersion old_mod_vers new_mod_vers `thenM` \ recompile -> + if not recompile then + returnM upToDate + else + + -- CHECK EXPORT LIST + if checkExportList maybe_old_export_vers new_export_vers then + out_of_date_vers (ptext SLIT(" Export list changed")) + (fromJust maybe_old_export_vers) + new_export_vers + else -getConFieldNames new_name [] = returnRn [] + -- CHECK RULES + if old_rule_vers /= new_rule_vers then + out_of_date_vers (ptext SLIT(" Rules changed")) + old_rule_vers new_rule_vers + else -getClassOpNames new_name (ClassOpSig op _ _ src_loc) = new_name op src_loc -\end{code} + -- CHECK ITEMS ONE BY ONE + checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenM` \ recompile -> + if recompile then + returnM outOfDate -- This one failed, so just bail out now + else + up_to_date (ptext SLIT(" Great! The bits I use are up to date")) -@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. + }} -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. +------------------------ +checkModuleVersion old_mod_vers new_mod_vers + | new_mod_vers == old_mod_vers + = up_to_date (ptext SLIT("Module version unchanged")) -\begin{code} -getDeclSysBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ tname dname dwname snames src_loc)) - = sequenceRn [new_name n src_loc | n <- (tname : dname : dwname : snames)] + | otherwise + = out_of_date_vers (ptext SLIT(" Module version has changed")) + old_mod_vers new_mod_vers -getDeclSysBinders new_name (TyClD (TyData _ _ _ _ cons _ _ _ _)) - = sequenceRn [new_name wkr_name src_loc | ConDecl _ wkr_name _ _ _ src_loc <- cons] +------------------------ +checkExportList Nothing new_vers = upToDate +checkExportList (Just v) new_vers = v /= new_vers -getDeclSysBinders new_name other_decl - = returnRn [] -\end{code} +------------------------ +checkEntityUsage new_vers (name,old_vers) + = case lookupNameEnv new_vers name of -%********************************************************* -%* * -\subsection{Reading an interface file} -%* * -%********************************************************* + Nothing -> -- We used it before, but it ain't there now + out_of_date (sep [ptext SLIT("No longer exported:"), ppr name]) -\begin{code} -findAndReadIface :: SDoc -> ModuleName - -> IsBootInterface -- True <=> Look for a .hi-boot file - -- False <=> Look for .hi file - -> RnM d (Either Message ParsedIface) - -- Nothing <=> file not found, or unreadable, or illegible - -- Just x <=> successfully found and parsed - -findAndReadIface doc_str mod_name hi_boot_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` \ (search_path, hi_map, hiboot_map) -> - let - relevant_map | hi_boot_file = hiboot_map - | otherwise = hi_map - in - case lookupFM relevant_map mod_name of - -- Found the file - Just fpath -> traceRn (ptext SLIT("...reading from") <+> text fpath) `thenRn_` - readIface mod_name fpath - - -- Can't find it - Nothing -> traceRn (ptext SLIT("...not found")) `thenRn_` - returnRn (Left (noIfaceErr mod_name hi_boot_file search_path)) + Just new_vers -- It's there, but is it up to date? + | new_vers == old_vers -> traceHiDiffs (text " Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenM_` + returnM upToDate + | otherwise -> out_of_date_vers (ptext SLIT(" Out of date:") <+> ppr name) + old_vers new_vers - where - trace_msg = sep [hsep [ptext SLIT("Reading"), - if hi_boot_file then ptext SLIT("[boot]") else empty, - ptext SLIT("interface for"), - pprModuleName mod_name <> semi], - nest 4 (ptext SLIT("reason:") <+> doc_str)] +up_to_date msg = traceHiDiffs msg `thenM_` returnM upToDate +out_of_date msg = traceHiDiffs msg `thenM_` returnM outOfDate +out_of_date_vers msg old_vers new_vers + = out_of_date (hsep [msg, ppr old_vers, ptext SLIT("->"), ppr new_vers]) \end{code} -@readIface@ tries just the one file. - -\begin{code} -readIface :: ModuleName -> String -> RnM d (Either Message ParsedIface) - -- Nothing <=> file not found, or unreadable, or illegible - -- Just x <=> successfully found and parsed -readIface wanted_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 - POk _ (PIface iface) -> - warnCheckRn (read_mod == wanted_mod) - (hiModuleNameMismatchWarn wanted_mod read_mod) `thenRn_` - returnRn (Right iface) - where - read_mod = moduleName (pi_mod iface) - - PFailed err -> bale_out err - parse_result -> bale_out empty - -- This last case can happen if the interface file is (say) empty - -- in which case the parser thinks it looks like an IdInfo or - -- something like that. Just an artefact of the fact that the - -- parser is used for several purposes at once. - - Left io_err -> bale_out (text (show io_err)) - where - bale_out err = returnRn (Left (badIfaceFile file_path err)) -\end{code} %********************************************************* %* * @@ -1182,49 +726,8 @@ readIface wanted_mod file_path %********************************************************* \begin{code} -noIfaceErr mod_name boot_file search_path - = vcat [ptext SLIT("Could not find interface file for") <+> quotes (pprModuleName mod_name), - ptext SLIT("in the directories") <+> - -- \& to avoid cpp interpreting this string as a - -- comment starter with a pre-4.06 mkdependHS --SDM - vcat [ text dir <> text "/\&*" <> pp_suffix suffix - | (dir,suffix) <- search_path] - ] - where - pp_suffix suffix | boot_file = ptext SLIT(".hi-boot") - | otherwise = text suffix - -badIfaceFile file err - = vcat [ptext SLIT("Bad interface file:") <+> text file, - nest 4 err] - getDeclErr name = vcat [ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name), ptext SLIT("from module") <+> quotes (ppr (nameModule 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 :: ModuleName -> ModuleName -> Message -hiModuleNameMismatchWarn requested_mod read_mod = - hsep [ ptext SLIT("Something is amiss; requested module name") - , pprModuleName requested_mod - , ptext SLIT("differs from name found in the interface file") - , pprModuleName read_mod - ] - \end{code}