X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnIfaces.lhs;h=08e7fb9948c974abf8efd3e240eb3753d9246273;hb=a237946da277f10bd3d223e5926d118044d24194;hp=797f8aa89592d571724172616e944eb96f172280;hpb=f9120c200bcf613b58d742802172fb4c08171f0d;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnIfaces.lhs b/ghc/compiler/rename/RnIfaces.lhs index 797f8aa..08e7fb9 100644 --- a/ghc/compiler/rename/RnIfaces.lhs +++ b/ghc/compiler/rename/RnIfaces.lhs @@ -1,112 +1,1229 @@ % -% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996 +% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % \section[RnIfaces]{Cacheing and Renaming of Interfaces} \begin{code} -#include "HsVersions.h" - module RnIfaces ( - cacheInterface, - readInterface, - rnInterfaces, - finalIfaceInfo, - IfaceCache(..), - VersionInfo(..), - ParsedIface(..) - ) where + findAndReadIface, -import PreludeGlaST ( returnPrimIO, thenPrimIO, - readVar, writeVar, MutableVar(..) ) + getInterfaceExports, getDeferredDecls, + getImportedInstDecls, getImportedRules, + lookupFixityRn, loadHomeInterface, + importDecl, ImportDeclResult(..), recordLocalSlurps, loadBuiltinRules, + mkImportExportInfo, getSlurped, -import Ubiq + checkModUsage, outOfDate, upToDate, -import HsSyn -import RdrHsSyn -import RnHsSyn + getDeclBinders, getDeclSysBinders, + removeContext -- removeContext probably belongs somewhere else + ) 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 HsImpExp ( ieNames ) +import CoreSyn ( CoreRule ) +import BasicTypes ( Version, NewOrData(..) ) +import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameRuleDecl, + RdrNameDeprecation, RdrNameIE, + extractHsTyRdrNames + ) +import RnEnv import RnMonad -import RnUtils ( RnEnv(..) ) +import ParseIface ( parseIface, IfaceStuff(..) ) -import Bag ( emptyBag ) -import ErrUtils ( Error(..), Warning(..) ) -import FiniteMap ( emptyFM, lookupFM, addToFM ) -import Pretty -import Maybes ( MaybeErr(..) ) -import Util ( panic ) +import Name ( Name {-instance NamedThing-}, nameOccName, + nameModule, isLocallyDefined, + isWiredInName, NamedThing(..), + elemNameEnv, extendNameEnv + ) +import Module ( Module, mkVanillaModule, pprModuleName, + moduleName, isLocalModule, + ModuleName, WhereFrom(..), + ) +import RdrName ( RdrName, rdrNameOcc ) +import NameSet +import SrcLoc ( mkSrcLoc, SrcLoc ) +import PrelInfo ( cCallishTyKeys ) +import Maybes ( maybeToBool ) +import Unique ( Uniquable(..) ) +import StringBuffer ( hGetStringBuffer ) +import FastString ( mkFastString ) +import ErrUtils ( Message ) +import Util ( sortLt ) +import Lex +import FiniteMap +import Outputable +import Bag +import List ( nub ) \end{code} +%********************************************************* +%* * +\subsection{Loading a new interface file} +%* * +%********************************************************* + \begin{code} -type IfaceCache = MutableVar _RealWorld (FiniteMap Module ParsedIface, - FiniteMap Module FAST_STRING) - -data ParsedIface = ParsedIface - - -cacheInterface :: IfaceCache -> Module - -> PrimIO (MaybeErr ParsedIface Error) - -cacheInterface iface_var mod - = readVar iface_var `thenPrimIO` \ (iface_fm, file_fm) -> - case lookupFM iface_fm mod of - Just iface -> returnPrimIO (Succeeded iface) - Nothing -> - case lookupFM file_fm mod of - Nothing -> returnPrimIO (Failed (noIfaceErr mod)) - Just file -> - readInterface file mod `thenPrimIO` \ read_iface -> - case read_iface of - Failed err -> returnPrimIO (Failed err) - Succeeded iface -> - let - iface_fm' = addToFM iface_fm mod iface - in - writeVar iface_var (iface_fm', file_fm) `thenPrimIO` \ _ -> - returnPrimIO (Succeeded iface) - - -readInterface :: FAST_STRING -> Module - -> PrimIO (MaybeErr ParsedIface Error) - -readInterface file mod = panic "readInterface" +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) + }} + +----------------------------------------------------- +-- 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! + + | 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 +----------------------------------------------------- + +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 -> + + 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 + } + 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 + + | 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 ... + -- + -- 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 + + +----------------------------------------------------- +-- 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))) \end{code} +%******************************************************** +%* * +\subsection{Checking usage information} +%* * +%******************************************************** + \begin{code} -rnInterfaces :: - IfaceCache -- iface cache - -> RnEnv -- original name env - -> UniqSupply - -> RenamedHsModule -- module to extend with iface decls - -> [RnName] -- imported names required - -> PrimIO (RenamedHsModule, -- extended module - ImplicitEnv, -- implicit names required - Bag Error, - Bag Warning) - -rnInterfaces iface_var occ_env us rn_module todo - = returnPrimIO (rn_module, (emptyFM, emptyFM), emptyBag, emptyBag) +upToDate = True +outOfDate = False + +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. + +checkModUsage [] = returnRn upToDate -- Yes! Everything is up to date! + +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 + + Nothing -> + 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 + 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 + + -- 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 + }} + where + doc_str = sep [ptext SLIT("need version info for"), pprModuleName mod_name] + + +checkEntityUsage mod decls [] + = returnRn upToDate -- Yes! All up to date! + +checkEntityUsage mod decls ((occ_name,old_vers) : rest) + = newGlobalName mod occ_name `thenRn` \ name -> + case lookupNameEnv decls name of + + Nothing -> -- We used it before, but it ain't there now + out_of_date (sep [ptext SLIT("No longer exported:"), ppr name]) + + Just (new_vers,_,_,_) -- It's there, but is it up to date? + | new_vers == old_vers + -- Up to date, so check the rest + -> checkEntityUsage mod decls rest + + | otherwise + -- Out of date, so bale out + -> out_of_date (sep [ptext SLIT("Out of date:"), ppr name]) + +out_of_date msg = traceRn msg `thenRn_` returnRn outOfDate \end{code} +%********************************************************* +%* * +\subsection{Getting in a declaration} +%* * +%********************************************************* + \begin{code} -finalIfaceInfo :: - IfaceCache -- iface cache - -> [RnName] -- all imported names required - -> [Module] -- directly imported modules - -> PrimIO (VersionInfo, -- info about version numbers - [Module]) -- special instance modules +importDecl :: Name -> RnMG ImportDeclResult + +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 -type VersionInfo = [(Module, Version, [(FAST_STRING, Version)])] + && (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. -finalIfaceInfo iface_var imps_reqd imp_mods - = returnPrimIO ([], []) + && 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 + + 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 + +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} +@getWiredInDecl@ maps a wired-in @Name@ to what it makes available. +It behaves exactly as if the wired in decl were actually in an interface file. +Specifically, +\begin{itemize} +\item if the wired-in name is a data type constructor or a data constructor, + it brings in the type constructor and all the data constructors; and + marks as ``occurrences'' any free vars of the data con. + +\item similarly for synonum type constructor + +\item if the wired-in name is another wired-in Id, it marks as ``occurrences'' + the free vars of the Id's type. + +\item it loads the interface file for the wired-in thing for the + sole purpose of making sure that its instance declarations are available +\end{itemize} +All this is necessary so that we know all types that are ``in play'', so +that we know just what instances to bring into scope. + + + + +%********************************************************* +%* * +\subsection{Getting what a module exports} +%* * +%********************************************************* + +@getInterfaceExports@ is called only for directly-imported modules. \begin{code} -noIfaceErr mod sty - = ppCat [ppStr "Could not find interface for", ppPStr mod] +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 + where + doc_str = sep [pprModuleName 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, _, Nothing)) <- 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) + +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 +\end{code} + + +%********************************************************* +%* * +\subsection{Keeping track of what we've slurped, and version numbers} +%* * +%********************************************************* + +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. + +\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 + traceRn (text "Modules in Ifaces: " <+> fsep (map ppr (keysFM mod_map))) `thenRn_` + 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 +\end{code} + +\begin{code} +getSlurped + = getIfacesRn `thenRn` \ ifaces -> + returnRn (iSlurp ifaces) + +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 } + +recordLocalSlurps local_avails + = getIfacesRn `thenRn` \ ifaces -> + let + new_slurped_names = foldl addAvailToNameSet (iSlurp ifaces) local_avails + in + setIfacesRn (ifaces { iSlurp = new_slurped_names }) +\end{code} + + +%********************************************************* +%* * +\subsection{Getting binders out of a declaration} +%* * +%********************************************************* + +@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 -> + + -- Record the names for the class ops + let + -- just want class-op sigs + op_sigs = filter isClassOpSig sigs + 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 + +binds_haskell_name (FoImport _) _ = True +binds_haskell_name FoLabel _ = True +binds_haskell_name FoExport ext_nm = isDynamicExtName ext_nm + +---------------- +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) + +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) + +getConFieldNames new_name [] = returnRn [] + +getClassOpNames new_name (ClassOpSig op _ _ src_loc) = new_name op src_loc +\end{code} + +@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. + +\begin{code} +getDeclSysBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ names + src_loc)) + = sequenceRn [new_name n src_loc | n <- names] + +getDeclSysBinders new_name (TyClD (TyData _ _ _ _ cons _ _ _ _ _ _)) + = sequenceRn [new_name wkr_name src_loc | ConDecl _ wkr_name _ _ _ src_loc <- cons] + +getDeclSysBinders new_name other_decl + = returnRn [] +\end{code} + +%********************************************************* +%* * +\subsection{Reading an interface file} +%* * +%********************************************************* + +\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 + bomb = panic "findAndReadInterface: hi_maps: FIXME" + search_path = panic "findAndReadInterface: search_path: FIXME" + relevant_map | hi_boot_file = bomb --hiboot_map + | otherwise = bomb --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)) + + 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)] +\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} + +%********************************************************* +%* * +\subsection{Errors} +%* * +%********************************************************* + +\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)) + ] + +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}