X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnIfaces.lhs;h=443c6429cf99d4c25f5624981f7ddfe4dcbf4402;hb=b73dab9410af24cf8f70f3b51aa0110020eae3f4;hp=8d371ceac936f5f5756e441bdcba3cf9fb805713;hpb=88f315a135bd00d2efa00d991bb9487929562d91;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnIfaces.lhs b/ghc/compiler/rename/RnIfaces.lhs index 8d371ce..443c642 100644 --- a/ghc/compiler/rename/RnIfaces.lhs +++ b/ghc/compiler/rename/RnIfaces.lhs @@ -6,7 +6,6 @@ \begin{code} module RnIfaces ( - getInterfaceExports, recordLocalSlurps, mkImportInfo, @@ -24,33 +23,39 @@ import HsSyn ( HsDecl(..), Sig(..), TyClDecl(..), ConDecl(..), ConDetails(..), InstDecl(..), HsType(..), hsTyVarNames, getBangType ) import HsImpExp ( ImportDecl(..) ) -import RdrHsSyn ( RdrNameHsDecl, RdrNameTyClDecl, RdrNameInstDecl ) -import RnHsSyn ( RenamedHsDecl, extractHsTyNames, extractHsCtxtTyNames, tyClDeclFVs ) -import RnHiFiles ( tryLoadInterface, loadHomeInterface, loadInterface, +import RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl ) +import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl, + extractHsTyNames, extractHsCtxtTyNames, + tyClDeclFVs, ruleDeclFVs, instDeclFVs + ) +import RnHiFiles ( tryLoadInterface, loadHomeInterface, loadOrphanModules ) -import RnSource ( rnTyClDecl, rnDecl ) +import RnSource ( rnTyClDecl, rnInstDecl, rnIfaceRuleDecl ) import RnEnv import RnMonad -import Id ( idType ) -import Type ( namesOfType ) -import TyCon ( isSynTyCon, getSynTyConDefn ) +import Id ( idType, idName, globalIdDetails ) +import IdInfo ( GlobalIdDetails(..) ) +import TcType ( namesOfType ) +import FieldLabel ( fieldLabelTyCon ) +import DataCon ( dataConTyCon ) +import TyCon ( isSynTyCon, getSynTyConDefn, tyConClass_maybe, tyConName ) +import Class ( className ) import Name ( Name {-instance NamedThing-}, nameOccName, - nameModule, isLocalName, nameUnique, - NamedThing(..), - elemNameEnv + nameModule, isLocalName, NamedThing(..) ) +import NameEnv ( elemNameEnv, delFromNameEnv, lookupNameEnv ) +import NameSet import Module ( Module, ModuleEnv, - moduleName, isModuleInThisPackage, + moduleName, isHomeModule, ModuleName, WhereFrom(..), emptyModuleEnv, extendModuleEnv_C, foldModuleEnv, lookupModuleEnv, elemModuleSet, extendModuleSet ) -import NameSet -import PrelInfo ( wiredInThingEnv, fractionalClassKeys ) -import TysWiredIn ( doubleTyCon ) -import Maybes ( orElse ) +import PrelInfo ( wiredInThingEnv, hasKey, fractionalClassKey, numClassKey, + integerTyConName, doubleTyConName ) +import Maybes ( maybeToBool ) import FiniteMap import Outputable import Bag @@ -60,105 +65,23 @@ import Util ( sortLt ) %********************************************************* %* * -\subsection{Getting what a module exports} -%* * -%********************************************************* - -@getInterfaceExports@ is called only for directly-imported modules. - -\begin{code} -getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, [(ModuleName,Avails)]) -getInterfaceExports mod_name from - = loadInterface doc_str mod_name from `thenRn` \ iface -> - returnRn (mi_module iface, mi_exports iface) - where - doc_str = sep [ppr mod_name, ptext SLIT("is directly imported")] -\end{code} - - -%********************************************************* -%* * -\subsection{Instance declarations are handled specially} -%* * -%********************************************************* - -\begin{code} -getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)] -getImportedInstDecls gates - = -- First, load any orphan-instance modules that aren't aready loaded - -- Orphan-instance modules are recorded in the module dependecnies - getIfacesRn `thenRn` \ ifaces -> - let - orphan_mods = - [mod | (mod, (True, _)) <- fmToList (iImpModInfo ifaces)] - in - loadOrphanModules orphan_mods `thenRn_` - - -- Now we're ready to grab the instance declarations - -- Find the un-gated ones and return them, - -- removing them from the bag kept in Ifaces - getIfacesRn `thenRn` \ ifaces -> - let - (decls, new_insts) = selectGated gates (iInsts ifaces) - in - setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_` - - traceRn (sep [text "getImportedInstDecls:", - nest 4 (fsep (map ppr gate_list)), - text "Slurped" <+> int (length decls) <+> text "instance declarations", - nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_` - returnRn decls - where - gate_list = nameSetToList gates - -ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _)) - = case inst_ty of - HsForAllTy _ _ tau -> ppr tau - other -> ppr inst_ty - -getImportedRules :: RnMG [(Module,RdrNameHsDecl)] -getImportedRules - | opt_IgnoreIfacePragmas = returnRn [] - | otherwise - = getIfacesRn `thenRn` \ ifaces -> - let - gates = iSlurp ifaces -- Anything at all that's been slurped - rules = iRules ifaces - (decls, new_rules) = selectGated gates rules - in - if null decls then - returnRn [] - else - setIfacesRn (ifaces { iRules = new_rules }) `thenRn_` - traceRn (sep [text "getImportedRules:", - text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_` - returnRn decls - -selectGated gates decl_bag - -- Select only those decls whose gates are *all* in 'gates' -#ifdef DEBUG - | opt_NoPruneDecls -- Just to try the effect of not gating at all - = (foldrBag (\ (_,d) ds -> d:ds) [] decl_bag, emptyBag) -- Grab them all - - | otherwise -#endif - = foldrBag select ([], emptyBag) decl_bag - where - select (reqd, decl) (yes, no) - | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no) - | otherwise = (yes, (reqd,decl) `consBag` no) -\end{code} - - -%********************************************************* -%* * \subsection{Keeping track of what we've slurped, and version numbers} %* * %********************************************************* -getImportVersions figures out what the ``usage information'' for this +mkImportInfo 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: +things it uses. + +We produce a line for every module B below the module, A, currently being +compiled: + import B ; +to record the fact that A does import B indirectly. 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. + +The usage information records: \begin{itemize} \item (a) anything reachable from its body code @@ -196,17 +119,14 @@ number. But with -O, a module that imports A must be recompiled if 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. + *** Conclusion: if A mentions B.f in its export list, + behave just as if A mentioned B.f in its source code, + and slurp in B.f and all its transitive closure *** + [NB: If B was compiled with -O, but A isn't, we should really *still* haul in all the unfoldings for B, in case the module that imports A *is* compiled with -O. I think this is the case.] -Even if B is used at all we get a usage line for B - import B :: ... ; -in A.hi, to record the fact that A does import B. This is used to decide -to look to look for B.hi rather than B.hi-boot when compiling a module that -imports A. This line says that A imports B, but uses nothing in it. -So we'll get an early bale-out when compiling A if B's version changes. - \begin{code} mkImportInfo :: ModuleName -- Name of this module -> [ImportDecl n] -- The import decls @@ -259,9 +179,14 @@ mkImportInfo this_mod imports 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 + import_info = not_even_opened_imports ++ import_info1 + + -- Recall that iImpModInfo describes modules that have been mentioned + -- in the import lists of interfaces we have opened, but which we have + -- not even opened when compiling this module + not_even_opened_imports = [ (mod_name, orphans, is_boot, NothingAtAll) + | (mod_name, (orphans, is_boot)) <- fmToList (iImpModInfo ifaces) ] + mk_imp_info :: ModIface -> [ImportVersion Name] -> [ImportVersion Name] mk_imp_info iface so_far @@ -276,6 +201,8 @@ mkImportInfo this_mod imports | 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) + -- Since the module isn't in the mv_map, presumably we + -- didn't actually import anything at all from it else go_for_it (Everything mod_vers) @@ -288,7 +215,7 @@ mkImportInfo this_mod imports mod = mi_module iface mod_name = moduleName mod - is_home_pkg_mod = isModuleInThisPackage mod + is_home_pkg_mod = isHomeModule mod version_info = mi_version iface version_env = vers_decls version_info mod_vers = vers_module version_info @@ -299,8 +226,7 @@ mkImportInfo this_mod imports -- 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) + let v = lookupVersion version_env n ] where lt_occ n1 n2 = nameOccName n1 < nameOccName n2 @@ -323,27 +249,20 @@ slurpImpDecls source_fvs = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_` -- The current slurped-set records all local things - getSlurped `thenRn` \ source_binders -> - slurpSourceRefs source_binders source_fvs `thenRn` \ (decls, needed) -> + slurpSourceRefs source_fvs `thenRn` \ (decls, needed) -> -- Then get everything else - closeDecls decls needed `thenRn` \ decls1 -> - - -- Finally, get any deferred data type decls - slurpDeferredDecls decls1 `thenRn` \ final_decls -> - - returnRn final_decls + closeDecls decls needed ------------------------------------------------------- -slurpSourceRefs :: NameSet -- Variables defined in source - -> FreeVars -- Variables referenced in source +slurpSourceRefs :: FreeVars -- Variables referenced in source -> RnMG ([RenamedHsDecl], FreeVars) -- Un-satisfied needs -- The declaration (and hence home module) of each gate has -- already been loaded -slurpSourceRefs source_binders source_fvs +slurpSourceRefs source_fvs = go_outer [] -- Accumulating decls emptyFVs -- Unsatisfied needs emptyFVs -- Accumulating gates @@ -354,10 +273,10 @@ slurpSourceRefs source_binders source_fvs -- 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. + -- It may be that Baz and Maybe are used in the source module, + -- but not Foo; so we need to chase Foo too. -- - -- We also need to follow superclass refs. In particular, 'chasing @Foo@' must + -- 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. @@ -370,32 +289,23 @@ slurpSourceRefs source_binders source_fvs = traceRn (text "go_outer" <+> ppr refs) `thenRn_` foldlRn go_inner (decls, fvs, emptyFVs) refs `thenRn` \ (decls1, fvs1, gates1) -> getImportedInstDecls (all_gates `plusFV` gates1) `thenRn` \ inst_decls -> - rnInstDecls decls1 fvs1 gates1 inst_decls `thenRn` \ (decls2, fvs2, gates2) -> + 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 + -- and we get an infinite loop go_inner (decls, fvs, gates) wanted_name = importDecl wanted_name `thenRn` \ import_result -> case import_result of - AlreadySlurped -> returnRn (decls, fvs, gates) - WiredIn -> returnRn (decls, fvs, gates `plusFV` getWiredInGates wanted_name) - Deferred -> returnRn (decls, fvs, gates `addOneFV` wanted_name) -- It's a type constructor + 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) - -rnInstDecls decls fvs gates [] - = returnRn (decls, fvs, gates) -rnInstDecls decls fvs gates (d:ds) - = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) -> - rnInstDecls (new_decl:decls) - (fvs1 `plusFV` fvs) - (gates `plusFV` getInstDeclGates new_decl) - ds \end{code} @@ -411,8 +321,13 @@ closeDecls decls needed = getImportedRules `thenRn` \ rule_decls -> case rule_decls of [] -> returnRn decls -- No new rules, so we are done - other -> rnIfaceDecls decls emptyFVs rule_decls `thenRn` \ (decls1, needed1) -> - closeDecls decls1 needed1 + 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 + ------------------------------------------------------- @@ -438,148 +353,166 @@ slurpDecl decls fvs wanted_name ------------------------------------------------------- -rnIfaceDecls :: [RenamedHsDecl] -> FreeVars - -> [(Module, RdrNameHsDecl)] - -> RnM d ([RenamedHsDecl], FreeVars) -rnIfaceDecls decls fvs [] = returnRn (decls, fvs) -rnIfaceDecls decls fvs (d:ds) = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) -> - rnIfaceDecls (new_decl:decls) (fvs1 `plusFV` fvs) ds - -rnIfaceDecl (mod, decl) = initIfaceRnMS mod (rnDecl decl) +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} -getSlurped - = getIfacesRn `thenRn` \ ifaces -> - returnRn (iSlurp ifaces) - -recordSlurp ifaces@(Ifaces { iSlurp = slurped_names, iVSlurp = (imp_mods, imp_names) }) +recordDeclSlurp ifaces@(Ifaces { iDecls = (decls_map, n_slurped), + iSlurp = slurped_names, + iVSlurp = vslurp }) avail - = ASSERT2( not (isLocalName (availName avail)), pprAvail avail ) - ifaces { iSlurp = new_slurped_names, iVSlurp = new_vslurp } + = ASSERT2( not (isLocalName (availName avail)), ppr avail ) + ifaces { iDecls = (new_decls_map, n_slurped+1), + iSlurp = new_slurped_names, + iVSlurp = updateVSlurp vslurp (availName avail) } where - main_name = availName avail - mod = nameModule main_name + new_decls_map = foldl delFromNameEnv decls_map (availNames avail) new_slurped_names = addAvailToNameSet slurped_names avail - new_vslurp | isModuleInThisPackage mod = (imp_mods, addOneToNameSet imp_names main_name) - | otherwise = (extendModuleSet imp_mods mod, imp_names) -recordLocalSlurps local_avails + +-- recordTypeEnvSlurp is used when we slurp something that's +-- already in the type environment, that was not slurped in an earlier compilation. +-- We record it in the iVSlurp set, because that's used to +-- generate usage information + +recordTypeEnvSlurp ifaces ty_thing + = ifaces { iVSlurp = updateVSlurp (iVSlurp ifaces) (get_main_name ty_thing) } + where + -- 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 + +updateVSlurp (imp_mods, imp_names) main_name + | isHomeModule mod = (imp_mods, addOneToNameSet imp_names main_name) + | otherwise = (extendModuleSet imp_mods mod, imp_names) + where + mod = nameModule main_name + +recordLocalSlurps new_names = getIfacesRn `thenRn` \ ifaces -> - let - new_slurped_names = foldl addAvailToNameSet (iSlurp ifaces) local_avails - in - setIfacesRn (ifaces { iSlurp = new_slurped_names }) + setIfacesRn (ifaces { iSlurp = iSlurp ifaces `unionNameSets` new_names }) \end{code} %********************************************************* %* * -\subsection{Deferred declarations} +\subsection{Extracting the `gates'} %* * %********************************************************* -The idea of deferred declarations is this. Suppose we have a function - f :: T -> Int - data T = T1 A | T2 B - data A = A1 X | A2 Y - data B = B1 P | B2 Q -Then we don't want to load T and all its constructors, and all -the types those constructors refer to, and all the types *those* -constructors refer to, and so on. That might mean loading many more -interface files than is really necessary. So we 'defer' loading T. - -But f might be strict, and the calling convention for evaluating -values of type T depends on how many constructors T has, so -we do need to load T, but not the full details of the type T. -So we load the full decl for T, but only skeleton decls for A and B: - f :: T -> Int - data T = {- 2 constructors -} - -Whether all this is worth it is moot. +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. -\begin{code} -slurpDeferredDecls :: [RenamedHsDecl] -> RnMG [RenamedHsDecl] -slurpDeferredDecls decls = returnRn decls - -{- OMIT FOR NOW -slurpDeferredDecls :: [RenamedHsDecl] -> RnMG [RenamedHsDecl] -slurpDeferredDecls decls - = getDeferredDecls `thenRn` \ def_decls -> - rnIfaceDecls decls emptyFVs (map stripDecl def_decls) `thenRn` \ (decls1, fvs) -> - ASSERT( isEmptyFVs fvs ) - returnRn decls1 - -stripDecl (mod, TyClD (TyData dt _ tc tvs _ nconstrs _ loc name1 name2)) - = (mod, TyClD (TyData dt [] tc tvs [] nconstrs Nothing loc - name1 name2)) - -- Nuke the context and constructors - -- But retain the *number* of constructors! - -- Also the tvs will have kinds on them. --} -\end{code} + 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. -%********************************************************* -%* * -\subsection{Extracting the `gates'} -%* * -%********************************************************* +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: + + instance Foo a => Baz (Maybe a) where ... + +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 -\begin{verbatim} + data T = T1 Wibble | T2 Wobble -\end{verbatim} -we don't want to treat @Wibble@ and @Wobble@ as gates -{\em unless} @T1@, @T2@ respectively are mentioned by the user program. -If only @T@ is mentioned -we want only @T@ to be a gate; -that way we don't suck in useless instance -decls for (say) @Eq Wibble@, when they can't possibly be useful. +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} -getGates source_fvs (IfaceSig _ ty _ _) - = extractHsTyNames ty - -getGates source_fvs (ClassDecl ctxt cls tvs _ sigs _ _ _ ) - = (delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) sigs) - (hsTyVarNames tvs) - `addOneToNameSet` cls) - `plusFV` maybe_double +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 (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 _) - | n `elemNameSet` source_fvs = extractHsTyNames ty - | otherwise = emptyFVs - - -- If we load any numeric class that doesn't have - -- Int as an instance, add Double to the gates. - -- This takes account of the fact that Double might be needed for - -- defaulting, but we don't want to load Double (and all its baggage) - -- if the more exotic classes aren't used at all. - maybe_double | nameUnique cls `elem` fractionalClassKeys - = unitFV (getName doubleTyCon) - | otherwise - = emptyFVs - -getGates source_fvs (TySynonym tycon tvs ty _) - = delListFromNameSet (extractHsTyNames ty) - (hsTyVarNames tvs) + | 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 -getGates source_fvs (TyData _ ctxt tycon tvs cons _ _ _ _ _) +get_gates is_used (TyData {tcdCtxt = ctxt, tcdName = tycon, tcdTyVars = tvs, tcdCons = cons}) = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) cons) (hsTyVarNames tvs) `addOneToNameSet` tycon where get (ConDecl n _ tvs ctxt details _) - | n `elemNameSet` source_fvs + | is_used n -- If the constructor is method, get fvs from all its fields = delListFromNameSet (get_details details `plusFV` extractHsCtxtTyNames ctxt) @@ -597,35 +530,137 @@ getGates source_fvs (TyData _ ctxt tycon tvs cons _ _ _ _ _) 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 (`elemNameSet` source_fvs) fs = get_bang t - | otherwise = emptyFVs + get_field (fs,t) | any is_used fs = get_bang t + | otherwise = emptyFVs 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 wired-in @Name@ -rather than a declaration. +@getWiredInGates@ is just like @getGates@, but it sees a previously-loaded +thing rather than a declaration. \begin{code} -getWiredInGates :: Name -> FreeVars -getWiredInGates name -- No classes are wired in - = case lookupNameEnv wiredInThingEnv name of - Just (AnId the_id) -> getWiredInGates_s (namesOfType (idType the_id)) - - Just (ATyCon tc) - | isSynTyCon tc - -> getWiredInGates_s (delListFromNameSet (namesOfType ty) (map getName tyvars)) - where - (tyvars,ty) = getSynTyConDefn tc - - other -> unitFV name +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) = implicitClassGates (getName cl) + -- The superclasses must also be previously + -- loaded, and hence are automatically gates + -- All previously-loaded classes are automatically gates + -- See "The gating story" above +getWiredInGates (ATyCon tc) + | isSynTyCon tc = delListFromNameSet (namesOfType ty) (map getName tyvars) + | otherwise = unitFV (getName tc) + where + (tyvars,ty) = getSynTyConDefn tc -getWiredInGates_s names = foldr (plusFV . getWiredInGates) emptyFVs (nameSetToList names) +getInstDeclGates (InstDecl inst_ty _ _ _ _) = extractHsTyNames inst_ty \end{code} \begin{code} -getInstDeclGates (InstD (InstDecl inst_ty _ _ _ _)) = extractHsTyNames inst_ty -getInstDeclGates other = emptyFVs +getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameInstDecl)] +getImportedInstDecls gates + = -- First, load any orphan-instance modules that aren't aready loaded + -- Orphan-instance modules are recorded in the module dependecnies + getIfacesRn `thenRn` \ ifaces -> + let + orphan_mods = + [mod | (mod, (True, _)) <- fmToList (iImpModInfo ifaces)] + in + loadOrphanModules orphan_mods `thenRn_` + + -- Now we're ready to grab the instance declarations + -- Find the un-gated ones and return them, + -- removing them from the bag kept in Ifaces + getIfacesRn `thenRn` \ ifaces -> + getTypeEnvRn `thenRn` \ lookup -> + let + available n + | n `elemNameSet` gates = True + | otherwise = case lookup n of { Just (AClass c) -> True; other -> False } + -- See "The gating story" above for the AClass thing + + (decls, new_insts) = selectGated available (iInsts ifaces) + in + setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_` + + traceRn (sep [text "getImportedInstDecls:", + nest 4 (fsep (map ppr gate_list)), + text "Slurped" <+> int (length decls) <+> text "instance declarations", + nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_` + returnRn decls + where + gate_list = nameSetToList gates + +ppr_brief_inst_decl (mod, InstDecl inst_ty _ _ _ _) + = case inst_ty of + HsForAllTy _ _ tau -> ppr tau + other -> ppr inst_ty + +getImportedRules :: RnMG [(Module,RdrNameRuleDecl)] +getImportedRules + | opt_IgnoreIfacePragmas = returnRn [] + | otherwise + = getIfacesRn `thenRn` \ ifaces -> + getTypeEnvRn `thenRn` \ lookup -> + let + -- Slurp rules for anything that is slurped, + -- either now or previously + gates = iSlurp ifaces + available n = n `elemNameSet` gates || maybeToBool (lookup n) + (decls, new_rules) = selectGated available (iRules ifaces) + in + if null decls then + returnRn [] + else + setIfacesRn (ifaces { iRules = new_rules }) `thenRn_` + traceRn (sep [text "getImportedRules:", + text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_` + returnRn decls + +selectGated :: (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 + = let + decls = foldrBag (\ (_,d) ds -> d:ds) [] decl_bag -- Grab them all + in + (decls, (emptyBag, n_slurped + length decls)) + + | otherwise +#endif + = case foldrBag select ([], emptyBag) decl_bag of + (decls, new_bag) -> (decls, (new_bag, n_slurped + length decls)) + where + select (reqd, decl) (yes, no) + | all available reqd = (decl:yes, no) + | otherwise = (yes, (reqd,decl) `consBag` no) \end{code} @@ -640,126 +675,58 @@ importDecl :: Name -> RnMG ImportDeclResult data ImportDeclResult = AlreadySlurped - | WiredIn - | Deferred + | InTypeEnv TyThing | HereItIs (Module, RdrNameTyClDecl) importDecl name - = -- Check if it was loaded before beginning this module - if isLocalName name then - returnRn AlreadySlurped - else - checkAlreadyAvailable name `thenRn` \ done -> - if done then - returnRn AlreadySlurped - else - - -- Check if we slurped it in while compiling this module + = -- 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 + else - -- When we find a wired-in name we must load its home - -- module so that we find any instance decls lurking therein - if name `elemNameEnv` wiredInThingEnv then - loadHomeInterface doc name `thenRn_` - returnRn WiredIn - else getNonWiredInDecl name - where - doc = ptext SLIT("need home module for wired in thing") <+> ppr name - -getNonWiredInDecl :: Name -> RnMG ImportDeclResult -getNonWiredInDecl needed_name - = traceRn doc_str `thenRn_` - loadHomeInterface doc_str needed_name `thenRn_` - getIfacesRn `thenRn` \ ifaces -> - case lookupNameEnv (iDecls ifaces) needed_name of - -{- OMIT DEFERRED STUFF FOR NOW, TILL GHCI WORKS - Just (version, avail, is_tycon_name, decl@(_, TyClD (TyData DataType _ _ _ _ ncons _ _ _ _))) - -- This case deals with deferred import of algebraic data types - - | not opt_NoPruneTyDecls - - && (opt_IgnoreIfacePragmas || ncons > 1) - -- We only defer if imported interface pragmas are ingored - -- or if it's not a product type. - -- Sole reason: The wrapper for a strict function may need to look - -- inside its arg, and hence need to see its arg type's constructors. - - && not (getUnique tycon_name `elem` cCallishTyKeys) - -- Never defer ccall types; we have to unbox them, - -- and importing them does no harm - - - -> -- OK, so we're importing a deferrable data type - if needed_name == tycon_name - -- The needed_name is the TyCon of a data type decl - -- Record that it's slurped, put it in the deferred set - -- and don't return a declaration at all - setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces - `addOneToNameSet` tycon_name}) - version (AvailTC needed_name [needed_name])) `thenRn_` - returnRn Deferred + -- 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) - 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 --} - - Just (avail,_,decl) - -> setIfacesRn (recordSlurp ifaces avail) `thenRn_` - returnRn (HereItIs decl) - - Nothing - -> addErrRn (getDeclErr needed_name) `thenRn_` - returnRn AlreadySlurped - where - doc_str = ptext SLIT("need decl for") <+> ppr needed_name + | otherwise + -> -- Very important: record that we've seen it + -- See comments with recordTypeEnvSlurp + setIfacesRn (recordTypeEnvSlurp ifaces ty_thing) `thenRn_` + returnRn (InTypeEnv ty_thing) ; + + Nothing -> -{- OMIT FOR NOW -getDeferredDecls :: RnMG [(Module, RdrNameHsDecl)] -getDeferredDecls - = getIfacesRn `thenRn` \ ifaces -> + -- 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 -> + + -- STEP 4: Get the declaration out let - decls_map = iDecls ifaces - deferred_names = nameSetToList (iDeferred ifaces) - get_abstract_decl n = case lookupNameEnv decls_map n of - Just (_, _, _, decl) -> decl + (decls_map, _) = iDecls ifaces in - traceRn (sep [text "getDeferredDecls", nest 4 (fsep (map ppr deferred_names))]) `thenRn_` - returnRn (map get_abstract_decl deferred_names) --} -\end{code} + case lookupNameEnv decls_map name of + Just (avail,_,decl) -> setIfacesRn (recordDeclSlurp ifaces avail) `thenRn_` + returnRn (HereItIs decl) -@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 + 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 -\item if the wired-in name is another wired-in Id, it marks as ``occurrences'' - the free vars of the Id's type. +\end{code} -\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. - %******************************************************** %* * @@ -778,17 +745,10 @@ 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 - = traceRn (text "Considering whether compilation is required for" <+> text iface_path <> colon) `thenRn_` - - -- CHECK WHETHER THE SOURCE HAS CHANGED - if not source_unchanged then - traceRn (nest 4 (text "Source file changed or recompilation check turned off")) `thenRn_` - returnRn outOfDate - else +recompileRequired iface_path iface + = traceHiDiffsRn (text "Considering whether compilation is required for" <+> text iface_path <> colon) `thenRn_` -- Source code unchanged and no errors yet... carry on checkList [checkModUsage u | u <- mi_usages iface] @@ -816,8 +776,22 @@ checkModUsage (mod_name, _, _, NothingAtAll) -- In this case we don't even want to open Foo's interface. = up_to_date (ptext SLIT("Nothing used from:") <+> ppr mod_name) -checkModUsage (mod_name, _, _, whats_imported) - = tryLoadInterface doc_str mod_name ImportBySystem `thenRn` \ (iface, maybe_err) -> +checkModUsage (mod_name, _, is_boot, whats_imported) + = -- Load the imported interface is possible + -- We use tryLoadInterface, because failure is not an error + -- (might just be that the old .hi file for this module is out of date) + -- We use ImportByUser/ImportByUserSource as the 'from' flag, + -- a) because we need to know whether to load the .hi-boot file + -- b) because loadInterface things matters are amiss if we + -- ImportBySystem an interface it knows nothing about + let + doc_str = sep [ptext SLIT("need version info for"), ppr mod_name] + from | is_boot = ImportByUserSource + | otherwise = ImportByUser + in + traceHiDiffsRn (text "Checking usages for module" <+> ppr mod_name) `thenRn_` + tryLoadInterface doc_str mod_name from `thenRn` \ (iface, maybe_err) -> + case maybe_err of { Just err -> out_of_date (sep [ptext SLIT("Can't find version number for module"), ppr mod_name]) ; @@ -864,8 +838,6 @@ checkModUsage (mod_name, _, _, whats_imported) up_to_date (ptext SLIT("...but the bits I use haven't.")) }} - where - doc_str = sep [ptext SLIT("need version info for"), ppr mod_name] ------------------------ checkModuleVersion old_mod_vers new_vers @@ -887,11 +859,11 @@ checkEntityUsage new_vers (name,old_vers) out_of_date (sep [ptext SLIT("No longer exported:"), ppr name]) Just new_vers -- It's there, but is it up to date? - | new_vers == old_vers -> returnRn upToDate + | new_vers == old_vers -> traceHiDiffsRn (text "Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenRn_` returnRn upToDate | otherwise -> out_of_date (sep [ptext SLIT("Out of date:"), ppr name]) -up_to_date msg = traceRn msg `thenRn_` returnRn upToDate -out_of_date msg = traceRn msg `thenRn_` returnRn outOfDate +up_to_date msg = traceHiDiffsRn msg `thenRn_` returnRn upToDate +out_of_date msg = traceHiDiffsRn msg `thenRn_` returnRn outOfDate \end{code}