%
-% (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, mod_info) of
+ (ImportByUser, _) -> False -- Not hi-boot
+ (ImportByUserSource, _) -> True -- hi-boot
+ (ImportBySystem, Just (_, is_boot, _)) -> is_boot --
+ (ImportBySystem, 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 (_, _, True)
+ -> -- 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_resultb ->
+ 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
+ new_mod_map = addToFM mod_map mod_name (False, False, True)
+ new_ifaces = ifaces { iImpModInfo = new_mod_map }
+ in
+ setIfacesRn new_ifaces `thenRn_`
+ returnRn (new_ifaces, Just err) ;
+
+ -- Found and parsed!
+ Right (mod, iface) ->
+
+ -- LOAD IT INTO Ifaces
+
+ -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
+ --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
+ -- If we do loadExport first the wrong info gets into the cache (unless we
+ -- explicitly tag each export which seems a bit of a bore)
+
+
+ -- 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 )
+
+ loadDecls mod (iDecls ifaces) (pi_decls iface) `thenRn` \ (decls_vers, new_decls) ->
+ loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ (rule_vers, new_rules) ->
+ loadFixDecls mod_name (pi_fixity iface) `thenRn` \ (fix_vers, fix_env) ->
+ foldlRn (loadDeprec mod) emptyDeprecEnv (pi_deprecs iface) `thenRn` \ deprec_env ->
+ foldlRn (loadInstDecl mod) (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
+ loadExports (pi_exports iface) `thenRn` \ avails ->
+ let
+ version = VersionInfo { modVers = pi_vers iface,
+ fixVers = fix_vers,
+ ruleVers = rule_vers,
+ declVers = decl_vers }
+
+ -- 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
+ mod_map2 = addToFM mod_map1 mod_name (pi_orphan iface, hi_boot_file, True)
+
+ -- Now add info about this module to the PST
+ new_pst = extendModuleEnv pst mod mod_detils
+ mod_details = ModDetails { mdModule = mod, mvVersion = version,
+ mdExports = avails,
+ mdFixEnv = fix_env, mdDeprecEnv = deprec_env }
+
+ new_ifaces = ifaces { iPST = new_pst,
+ iDecls = new_decls,
+ iInsts = new_insts,
+ iRules = new_rules,
+ iImpModInfo = mod_map2 }
+ in
+ setIfacesRn new_ifaces `thenRn_`
+ returnRn (new_ifaces, Nothing)
+ }}
+
+-----------------------------------------------------
+-- Adding module dependencies from the
+-- import decls in the interface file
+-----------------------------------------------------
+
+addModDeps :: Module -> PackageSymbolTable -> [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 :: (ModuleName, (WhetherHasOrphans, IsBootInterface))
+ filtered_new_deps
+ | isLocalModule mod = [ (imp_mod, (has_orphans, is_boot, False))
+ | (imp_mod, has_orphans, is_boot, _) <- new_deps
+ ]
+ | otherwise = [ (imp_mod, (True, False, False))
+ | (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, old_is_loaded) new
+ | old_is_loaded || 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
+-----------------------------------------------------
+
+loadExports :: [ExportItem] -> RnM d Avails
+loadExports items
+ = getModuleRn `thenRn` \ this_mod ->
+ mapRn (loadExport this_mod) items `thenRn` \ avails_s ->
+ returnRn (concat avails_s)
+
+
+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
+-----------------------------------------------------
+
+loadDecls :: Module
+ -> DeclsMap
+ -> [(Version, RdrNameHsDecl)]
+ -> RnM d (NameEnv Version, DeclsMap)
+loadDecls mod decls_map decls
+ = foldlRn (loadDecl mod) (emptyNameEnv, decls_map) decls
+
+loadDecl :: Module
+ -> (NameEnv Version, DeclsMap)
+ -> (Version, RdrNameHsDecl)
+ -> RnM d (NameEnv Version, DeclsMap)
+loadDecl mod (version_map, decls_map) (version, decl)
+ = getDeclBinders new_name decl `thenRn` \ maybe_avail ->
+ case maybe_avail of {
+ Nothing -> returnRn (version_map, 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, (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
+
+ new_version_map = extendNameEnv version_map main_name version
+ in
+ returnRn (new_version_map, 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 rdr_name loc
+
+ {-
+ 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 (version, decls)
+ | null decls = returnRn (version, emptyNameEnv)
+
+ | otherwise
+ = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
+ returnRn (version, mkNameEnv 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 (Version, IfaceRules)
+loadRules mod rule_bag (version, rules)
+ | null rules || opt_IgnoreIfacePragmas
+ = returnRn (version, rule_bag)
+ | otherwise
+ = setModuleRn mod $
+ mapRn (loadRule mod) rules `thenRn` \ new_rules ->
+ returnRn (version, 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
+ = getIfacesRn `thenRn` \ ifaces ->
+ getHomeSymbolTableRn `thenRn` \ hst ->
+ if name `elemNameSet` iSlurp ifaces
+ || inTypeEnv (iPST ifaces) name
+ || inTypeEnv hst name
+ then -- Already dealt with
+ returnRn AlreadySlurped
+
+ 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
+
+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
-type VersionInfo = [(Module, Version, [(FAST_STRING, Version)])]
+ | not opt_NoPruneTyDecls
-finalIfaceInfo iface_var imps_reqd imp_mods
- = returnPrimIO ([], [])
+ && (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
+
+ 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
+ = getHomeSymbolTableRn `thenRn` \ hst ->
+ case lookupModuleEnvByName hst mod_name of {
+ Just mds -> returnRn (mdModule mds, mdExports mds) ;
+
+ loadInterface doc_str mod_name from `thenRn` \ ifaces ->
+ case lookupModuleEnv (iPST ifaces) mod_name of
+ Just mds -> returnRn (mdModule mod, mdExports mds)
+ -- 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 (lookupLocalFixity 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.
+ = getHomeSymbolTableRn `thenRn` \ hst ->
+ case lookupFixityEnv hst name of {
+ Just fixity -> returnRn fixity ;
+ Nothing ->
+
+ loadHomeInterface doc name `thenRn` \ ifaces ->
+ returnRn (lookupFixityEnv (iPST ifaces) name `orElse` defaultFixity)
+ }
+ 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 <n> :: ... ;
+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 (Module, 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.
+
+ getFinderRn `thenRn` \ finder ->
+ ioToRn (findModule finder mod_name) `thenRn` \ maybe_module ->
+
+ case maybe_module of
+ Just mod | hi_boot_file, Just fpath <- moduleHiBootFile mod
+ -> readIface mod fpath
+ | not hi_boot_file, Just fpath <- moduleHiFile mod
+ -> readIface mod fpath
+
+ -- Can't find it
+ other -> traceRn (ptext SLIT("...not found")) `thenRn_`
+ returnRn (Left (noIfaceErr finder mod_name hi_boot_file))
+
+ 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 :: Module -> String -> RnM d (Either Message (Module, ParsedIface))
+ -- Nothing <=> file not found, or unreadable, or illegible
+ -- Just x <=> successfully found and parsed
+readIface wanted_mod file_path
+ = traceRn (ptext SLIT("...reading from") <+> text file_path) `thenRn_`
+ 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 (moduleName wanted_mod == read_mod)
+ (hiModuleNameMismatchWarn wanted_mod read_mod) `thenRn_`
+ returnRn (Right (mod, 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 :: Module -> ModuleName -> Message
+hiModuleNameMismatchWarn requested_mod read_mod =
+ hsep [ ptext SLIT("Something is amiss; requested module name")
+ , ppr requested_mod
+ , ptext SLIT("differs from name found in the interface file")
+ , pprModuleName read_mod
+ ]
+
\end{code}