2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[RnIfaces]{Cacheing and Renaming of Interfaces}
9 getImportedInstDecls, getImportedRules,
10 lookupFixity, loadHomeInterface,
11 importDecl, recordSlurp,
12 getImportVersions, getSlurped,
16 getDeclBinders, getDeclSysBinders,
17 removeContext -- removeContext probably belongs somewhere else
20 #include "HsVersions.h"
22 import CmdLineOpts ( opt_NoPruneDecls, opt_IgnoreIfacePragmas )
23 import HsSyn ( HsDecl(..), TyClDecl(..), InstDecl(..), IfaceSig(..),
24 HsType(..), ConDecl(..), IE(..), ConDetails(..), Sig(..),
25 ForeignDecl(..), ForKind(..), isDynamic,
26 FixitySig(..), RuleDecl(..),
29 import BasicTypes ( Version, NewOrData(..), defaultFixity )
30 import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameTyClDecl, RdrNameRuleDecl,
33 import RnEnv ( mkImportedGlobalName, newImportedBinder, mkImportedGlobalFromRdrName,
34 lookupOccRn, lookupImplicitOccRn,
36 availName, availNames, addAvailToNameSet,
40 import RnHsSyn ( RenamedHsDecl )
41 import ParseIface ( parseIface, IfaceStuff(..) )
43 import FiniteMap ( FiniteMap, sizeFM, emptyFM, delFromFM, listToFM,
44 lookupFM, addToFM, addToFM_C, addListToFM,
45 fmToList, elemFM, foldFM
47 import Name ( Name {-instance NamedThing-},
48 nameModule, isLocallyDefined,
49 isWiredInName, nameUnique, NamedThing(..)
51 import Module ( Module, moduleString, pprModule,
52 mkVanillaModule, pprModuleName,
53 moduleUserString, moduleName, isLibModule,
54 ModuleName, WhereFrom(..),
56 import RdrName ( RdrName, rdrNameOcc )
59 import SrcLoc ( mkSrcLoc, SrcLoc )
60 import PrelMods ( pREL_GHC )
61 import PrelInfo ( cCallishTyKeys, thinAirModules )
63 import Maybes ( MaybeErr(..), maybeToBool, orElse )
64 import ListSetOps ( unionLists )
66 import Unique ( Unique )
67 import StringBuffer ( StringBuffer, hGetStringBuffer )
68 import FastString ( mkFastString )
69 import ErrUtils ( Message )
73 import IO ( isDoesNotExistError )
78 %*********************************************************
80 \subsection{Loading a new interface file}
82 %*********************************************************
85 loadHomeInterface :: SDoc -> Name -> RnM d Ifaces
86 loadHomeInterface doc_str name
87 = loadInterface doc_str (moduleName (nameModule name)) ImportBySystem `thenRn` \ (_, ifaces) ->
90 loadOrphanModules :: [ModuleName] -> RnM d ()
91 loadOrphanModules mods
92 | null mods = returnRn ()
93 | otherwise = traceRn (text "Loading orphan modules:" <+> fsep (map pprModuleName mods)) `thenRn_`
94 mapRn_ load mods `thenRn_`
97 load mod = loadInterface (pprModuleName mod <+> ptext SLIT("is a orphan-instance module")) mod ImportBySystem
99 loadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d (Module, Ifaces)
100 loadInterface doc_str mod_name from
101 = getIfacesRn `thenRn` \ ifaces ->
103 mod_map = iImpModInfo ifaces
104 mod_info = lookupFM mod_map mod_name
105 in_map = maybeToBool mod_info
108 -- Issue a warning for a redundant {- SOURCE -} import
109 -- It's redundant if the moduld is in the iImpModInfo at all,
110 -- because we arrange to read all the ordinary imports before
111 -- any of the {- SOURCE -} imports
112 warnCheckRn (not (in_map && case from of {ImportByUserSource -> True; other -> False}))
113 (warnRedundantSourceImport mod_name) `thenRn_`
115 -- CHECK WHETHER WE HAVE IT ALREADY
117 Just (_, _, Just (load_mod, _, _))
118 -> -- We're read it already so don't re-read it
119 returnRn (load_mod, ifaces) ;
123 -- READ THE MODULE IN
124 findAndReadIface doc_str mod_name from in_map
125 `thenRn` \ (hi_boot_read, read_result) ->
126 case read_result of {
127 Nothing -> -- Not found, so add an empty export env to the Ifaces map
128 -- so that we don't look again
130 mod = mkVanillaModule mod_name
131 new_mod_map = addToFM mod_map mod_name (0, False, Just (mod, False, []))
132 new_ifaces = ifaces { iImpModInfo = new_mod_map }
134 setIfacesRn new_ifaces `thenRn_`
135 failWithRn (mod, new_ifaces) (noIfaceErr mod hi_boot_read) ;
140 -- LOAD IT INTO Ifaces
142 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
143 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
144 -- If we do loadExport first the wrong info gets into the cache (unless we
145 -- explicitly tag each export which seems a bit of a bore)
147 getModuleRn `thenRn` \ this_mod_nm ->
149 rd_decls = pi_decls iface
151 foldlRn (loadDecl mod) (iDecls ifaces) rd_decls `thenRn` \ new_decls ->
152 foldlRn (loadInstDecl mod) (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
153 (if (opt_IgnoreIfacePragmas)
154 then returnRn emptyBag
155 else foldlRn (loadRule mod) (iRules ifaces) (pi_rules iface)) `thenRn` \ new_rules ->
156 foldlRn (loadFixDecl mod_name) (iFixes ifaces) rd_decls `thenRn` \ new_fixities ->
157 mapRn (loadExport this_mod_nm) (pi_exports iface) `thenRn` \ avails_s ->
159 -- For an explicit user import, add to mod_map info about
160 -- the things the imported module depends on, extracted
161 -- from its usage info.
162 mod_map1 = case from of
163 ImportByUser -> addModDeps mod mod_map (pi_usages iface)
166 -- Now add info about this module
167 mod_map2 = addToFM mod_map1 mod_name mod_details
168 mod_details = (pi_mod iface, pi_orphan iface, Just (mod, hi_boot_read, concat avails_s))
170 new_ifaces = ifaces { iImpModInfo = mod_map2,
172 iFixes = new_fixities,
176 setIfacesRn new_ifaces `thenRn_`
177 returnRn (mod, new_ifaces)
180 addModDeps :: Module -> ImportedModuleInfo
181 -> [ImportVersion a] -> ImportedModuleInfo
182 addModDeps mod mod_deps new_deps
183 = foldr add mod_deps new_deps
185 is_lib = isLibModule mod -- Don't record dependencies when importing a library module
186 add (imp_mod, version, has_orphans, _) deps
187 | is_lib && not has_orphans = deps
188 | otherwise = addToFM_C combine deps imp_mod (version, has_orphans, Nothing)
189 -- Record dependencies for modules that are
190 -- either are dependent via a non-library module
191 -- or contain orphan rules or instance decls
193 -- Don't ditch a module that's already loaded!!
194 combine old@(_, _, Just _) new = old
195 combine old@(_, _, Nothing) new = new
197 loadExport :: ModuleName -> ExportItem -> RnM d [AvailInfo]
198 loadExport this_mod (mod, entities)
199 | mod == this_mod = returnRn []
200 -- If the module exports anything defined in this module, just ignore it.
201 -- Reason: otherwise it looks as if there are two local definition sites
202 -- for the thing, and an error gets reported. Easiest thing is just to
203 -- filter them out up front. This situation only arises if a module
204 -- imports itself, or another module that imported it. (Necessarily,
205 -- this invoves a loop.) Consequence: if you say
210 -- module B( AType ) where
211 -- import {-# SOURCE #-} A( AType )
213 -- then you'll get a 'B does not export AType' message. A bit bogus
214 -- but it's a bogus thing to do!
217 = mapRn (load_entity mod) entities
219 new_name mod occ = mkImportedGlobalName mod occ
221 load_entity mod (Avail occ)
222 = new_name mod occ `thenRn` \ name ->
223 returnRn (Avail name)
224 load_entity mod (AvailTC occ occs)
225 = new_name mod occ `thenRn` \ name ->
226 mapRn (new_name mod) occs `thenRn` \ names ->
227 returnRn (AvailTC name names)
230 loadFixDecl :: ModuleName -> FixityEnv
231 -> (Version, RdrNameHsDecl)
233 loadFixDecl mod_name fixity_env (version, FixD sig@(FixitySig rdr_name fixity loc))
234 = -- Ignore the version; when the fixity changes the version of
235 -- its 'host' entity changes, so we don't need a separate version
236 -- number for fixities
237 mkImportedGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
239 new_fixity_env = addToNameEnv fixity_env name (FixitySig name fixity loc)
241 returnRn new_fixity_env
243 -- Ignore the other sorts of decl
244 loadFixDecl mod_name fixity_env other_decl = returnRn fixity_env
248 -> (Version, RdrNameHsDecl)
251 loadDecl mod decls_map (version, decl)
252 = getDeclBinders new_name decl `thenRn` \ maybe_avail ->
253 case maybe_avail of {
254 Nothing -> returnRn decls_map; -- No bindings
257 getDeclSysBinders new_name decl `thenRn` \ sys_bndrs ->
259 main_name = availName avail
260 new_decls_map = foldl add_decl decls_map
261 [ (name, (version, avail, name==main_name, (mod, decl')))
262 | name <- sys_bndrs ++ availNames avail]
263 add_decl decls_map (name, stuff)
264 = WARN( name `elemNameEnv` decls_map, ppr name )
265 addToNameEnv decls_map name stuff
267 returnRn new_decls_map
270 -- newImportedBinder puts into the cache the binder with the
271 -- module information set correctly. When the decl is later renamed,
272 -- the binding site will thereby get the correct module.
273 new_name rdr_name loc = newImportedBinder mod rdr_name
276 If a signature decl is being loaded, and optIgnoreIfacePragmas is on,
277 we toss away unfolding information.
279 Also, if the signature is loaded from a module we're importing from source,
280 we do the same. This is to avoid situations when compiling a pair of mutually
281 recursive modules, peering at unfolding info in the interface file of the other,
282 e.g., you compile A, it looks at B's interface file and may as a result change
283 its interface file. Hence, B is recompiled, maybe changing its interface file,
284 which will the unfolding info used in A to become invalid. Simple way out is to
285 just ignore unfolding info.
287 [Jan 99: I junked the second test above. If we're importing from an hi-boot
288 file there isn't going to *be* any pragma info. Maybe the above comment
289 dates from a time where we picked up a .hi file first if it existed?]
292 SigD (IfaceSig name tp ls loc) | opt_IgnoreIfacePragmas
293 -> SigD (IfaceSig name tp [] loc)
296 loadInstDecl :: Module
299 -> RnM d (Bag GatedDecl)
300 loadInstDecl mod insts decl@(InstDecl inst_ty binds uprags dfun_name src_loc)
302 -- Find out what type constructors and classes are "gates" for the
303 -- instance declaration. If all these "gates" are slurped in then
304 -- we should slurp the instance decl too.
306 -- We *don't* want to count names in the context part as gates, though.
308 -- instance Foo a => Baz (T a) where ...
310 -- Here the gates are Baz and T, but *not* Foo.
312 munged_inst_ty = removeContext inst_ty
313 free_names = extractHsTyRdrNames munged_inst_ty
315 setModuleRn (moduleName mod) $
316 mapRn mkImportedGlobalFromRdrName free_names `thenRn` \ gate_names ->
317 returnRn ((mkNameSet gate_names, (mod, InstD decl)) `consBag` insts)
320 -- In interface files, the instance decls now look like
321 -- forall a. Foo a -> Baz (T a)
322 -- so we have to strip off function argument types as well
323 -- as the bit before the '=>' (which is always empty in interface files)
324 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
325 removeContext ty = removeFuns ty
327 removeFuns (MonoFunTy _ ty) = removeFuns ty
331 loadRule :: Module -> Bag GatedDecl
332 -> RdrNameRuleDecl -> RnM d (Bag GatedDecl)
333 -- "Gate" the rule simply by whether the rule variable is
334 -- needed. We can refine this later.
335 loadRule mod rules decl@(IfaceRuleDecl var body src_loc)
336 = setModuleRn (moduleName mod) $
337 mkImportedGlobalFromRdrName var `thenRn` \ var_name ->
338 returnRn ((unitNameSet var_name, (mod, RuleD decl)) `consBag` rules)
342 %********************************************************
344 \subsection{Loading usage information}
346 %********************************************************
349 checkUpToDate :: ModuleName -> RnMG Bool -- True <=> no need to recompile
350 checkUpToDate mod_name
351 = getIfacesRn `thenRn` \ ifaces ->
352 findAndReadIface doc_str mod_name
354 (error "checkUpToDate") `thenRn` \ (_, read_result) ->
356 -- CHECK WHETHER WE HAVE IT ALREADY
358 Nothing -> -- Old interface file not found, so we'd better bail out
359 traceRn (sep [ptext SLIT("Didnt find old iface"),
360 pprModuleName mod_name]) `thenRn_`
364 -> -- Found it, so now check it
365 checkModUsage (pi_usages iface)
367 -- Only look in current directory, with suffix .hi
368 doc_str = sep [ptext SLIT("need usage info from"), pprModuleName mod_name]
370 checkModUsage [] = returnRn True -- Yes! Everything is up to date!
372 checkModUsage ((mod_name, old_mod_vers, _, whats_imported) : rest)
373 = loadInterface doc_str mod_name ImportBySystem `thenRn` \ (mod, ifaces) ->
375 maybe_mod_vers = case lookupFM (iImpModInfo ifaces) mod_name of
376 Just (version, _, Just (_, _, _)) -> Just version
379 case maybe_mod_vers of {
380 Nothing -> -- If we can't find a version number for the old module then
381 -- bail out saying things aren't up to date
382 traceRn (sep [ptext SLIT("Can't find version number for module"),
383 pprModuleName mod_name])
384 `thenRn_` returnRn False ;
388 -- If the module version hasn't changed, just move on
389 if new_mod_vers == old_mod_vers then
390 traceRn (sep [ptext SLIT("Module version unchanged:"), pprModuleName mod_name])
391 `thenRn_` checkModUsage rest
393 traceRn (sep [ptext SLIT("Module version has changed:"), pprModuleName mod_name])
395 -- Module version changed, so check entities inside
397 -- If the usage info wants to say "I imported everything from this module"
398 -- it does so by making whats_imported equal to Everything
399 -- In that case, we must recompile
400 case whats_imported of {
401 Everything -> traceRn (ptext SLIT("...and I needed the whole module")) `thenRn_`
402 returnRn False; -- Bale out
404 Specifically old_local_vers ->
406 -- Non-empty usage list, so check item by item
407 checkEntityUsage mod_name (iDecls ifaces) old_local_vers `thenRn` \ up_to_date ->
409 traceRn (ptext SLIT("...but the bits I use haven't.")) `thenRn_`
410 checkModUsage rest -- This one's ok, so check the rest
412 returnRn False -- This one failed, so just bail out now
415 doc_str = sep [ptext SLIT("need version info for"), pprModuleName mod_name]
418 checkEntityUsage mod decls []
419 = returnRn True -- Yes! All up to date!
421 checkEntityUsage mod decls ((occ_name,old_vers) : rest)
422 = mkImportedGlobalName mod occ_name `thenRn` \ name ->
423 case lookupNameEnv decls name of
425 Nothing -> -- We used it before, but it ain't there now
426 traceRn (sep [ptext SLIT("No longer exported:"), ppr name])
427 `thenRn_` returnRn False
429 Just (new_vers,_,_,_) -- It's there, but is it up to date?
430 | new_vers == old_vers
431 -- Up to date, so check the rest
432 -> checkEntityUsage mod decls rest
435 -- Out of date, so bale out
436 -> traceRn (sep [ptext SLIT("Out of date:"), ppr name]) `thenRn_`
441 %*********************************************************
443 \subsection{Getting in a declaration}
445 %*********************************************************
448 importDecl :: Name -> RnMG (Maybe (Module, RdrNameHsDecl))
449 -- Returns Nothing for
452 -- (c) already slurped
458 = getSlurped `thenRn` \ already_slurped ->
459 if name `elemNameSet` already_slurped then
460 returnRn Nothing -- Already dealt with
462 if isLocallyDefined name then -- Don't bring in decls from
463 -- the renamed module's own interface file
464 addWarnRn (importDeclWarn name) `thenRn_`
467 getNonWiredInDecl name
471 getNonWiredInDecl :: Name -> RnMG (Maybe (Module, RdrNameHsDecl))
472 getNonWiredInDecl needed_name
473 = traceRn doc_str `thenRn_`
474 loadHomeInterface doc_str needed_name `thenRn` \ ifaces ->
475 case lookupNameEnv (iDecls ifaces) needed_name of
477 Just (version,avail,_,decl)
478 -> recordSlurp (Just version) avail `thenRn_`
481 Nothing -- Can happen legitimately for "Optional" occurrences
482 -> addErrRn (getDeclErr needed_name) `thenRn_`
485 doc_str = ptext SLIT("need decl for") <+> ppr needed_name
488 @getWiredInDecl@ maps a wired-in @Name@ to what it makes available.
489 It behaves exactly as if the wired in decl were actually in an interface file.
492 \item if the wired-in name is a data type constructor or a data constructor,
493 it brings in the type constructor and all the data constructors; and
494 marks as ``occurrences'' any free vars of the data con.
496 \item similarly for synonum type constructor
498 \item if the wired-in name is another wired-in Id, it marks as ``occurrences''
499 the free vars of the Id's type.
501 \item it loads the interface file for the wired-in thing for the
502 sole purpose of making sure that its instance declarations are available
504 All this is necessary so that we know all types that are ``in play'', so
505 that we know just what instances to bring into scope.
510 %*********************************************************
512 \subsection{Getting what a module exports}
514 %*********************************************************
516 @getInterfaceExports@ is called only for directly-imported modules.
519 getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, Avails)
520 getInterfaceExports mod_name from
521 = loadInterface doc_str mod_name from `thenRn` \ (mod, ifaces) ->
522 case lookupFM (iImpModInfo ifaces) mod_name of
523 Nothing -> -- Not there; it must be that the interface file wasn't found;
524 -- the error will have been reported already.
525 -- (Actually loadInterface should put the empty export env in there
526 -- anyway, but this does no harm.)
529 Just (_, _, Just (mod, _, avails)) -> returnRn (mod, avails)
531 doc_str = sep [pprModuleName mod_name, ptext SLIT("is directly imported")]
535 %*********************************************************
537 \subsection{Instance declarations are handled specially}
539 %*********************************************************
542 getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)]
543 getImportedInstDecls gates
544 = -- First, load any orphan-instance modules that aren't aready loaded
545 -- Orphan-instance modules are recorded in the module dependecnies
546 getIfacesRn `thenRn` \ ifaces ->
549 [mod | (mod, (_, True, Nothing)) <- fmToList (iImpModInfo ifaces)]
551 loadOrphanModules orphan_mods `thenRn_`
553 -- Now we're ready to grab the instance declarations
554 -- Find the un-gated ones and return them,
555 -- removing them from the bag kept in Ifaces
556 getIfacesRn `thenRn` \ ifaces ->
558 (decls, new_insts) = selectGated gates (iInsts ifaces)
560 setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_`
562 traceRn (sep [text "getImportedInstDecls:",
563 nest 4 (fsep (map ppr gate_list)),
564 text "Slurped" <+> int (length decls) <+> text "instance declarations",
565 nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_`
568 gate_list = nameSetToList gates
570 load_home gate | isLocallyDefined gate
573 = loadHomeInterface (ppr gate <+> text "is an instance gate") gate `thenRn_`
576 ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _))
578 HsForAllTy _ _ tau -> ppr tau
581 getImportedRules :: RnMG [(Module,RdrNameHsDecl)]
583 | opt_IgnoreIfacePragmas = returnRn []
585 = getIfacesRn `thenRn` \ ifaces ->
587 gates = iSlurp ifaces -- Anything at all that's been slurped
588 (decls, new_rules) = selectGated gates (iRules ifaces)
590 setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
591 traceRn (sep [text "getImportedRules:",
592 text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
595 selectGated gates decl_bag
596 -- Select only those decls whose gates are *all* in 'gates'
598 | opt_NoPruneDecls -- Just to try the effect of not gating at all
599 = (foldrBag (\ (_,d) ds -> d:ds) [] decl_bag, emptyBag) -- Grab them all
603 = foldrBag select ([], emptyBag) decl_bag
605 select (reqd, decl) (yes, no)
606 | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no)
607 | otherwise = (yes, (reqd,decl) `consBag` no)
609 lookupFixity :: Name -> RnMS Fixity
611 | isLocallyDefined name
612 = getFixityEnv `thenRn` \ local_fix_env ->
613 case lookupNameEnv local_fix_env name of
614 Just (FixitySig _ fix _) -> returnRn fix
615 Nothing -> returnRn defaultFixity
617 | otherwise -- Imported
618 = loadHomeInterface doc name `thenRn` \ ifaces ->
619 case lookupNameEnv (iFixes ifaces) name of
620 Just (FixitySig _ fix _) -> returnRn fix
621 Nothing -> returnRn defaultFixity
623 doc = ptext SLIT("Checking fixity for") <+> ppr name
627 %*********************************************************
629 \subsection{Keeping track of what we've slurped, and version numbers}
631 %*********************************************************
633 getImportVersions figures out what the ``usage information'' for this
634 moudule is; that is, what it must record in its interface file as the
635 things it uses. It records:
638 \item anything reachable from its body code
639 \item any module exported with a @module Foo@.
642 Why the latter? Because if @Foo@ changes then this module's export list
643 will change, so we must recompile this module at least as far as
644 making a new interface file --- but in practice that means complete
649 module A( f, g ) where | module B( f ) where
650 import B( f ) | f = h 3
654 Should we record @B.f@ in @A@'s usages? In fact we don't. Certainly,
655 if anything about @B.f@ changes than anyone who imports @A@ should be
656 recompiled; they'll get an early exit if they don't use @B.f@.
657 However, even if @B.f@ doesn't change at all, @B.h@ may do so, and
658 this change may not be reflected in @f@'s version number. So there
659 are two things going on when compiling module @A@:
662 \item Are @A.o@ and @A.hi@ correct? Then we can bale out early.
663 \item Should modules that import @A@ be recompiled?
666 For (1) it is slightly harmful to record @B.f@ in @A@'s usages,
667 because a change in @B.f@'s version will provoke full recompilation of
668 @A@, producing an identical @A.o@, and @A.hi@ differing only in its
669 usage-version of @B.f@ (and this usage-version info isn't used by any
672 For (2), because of the tricky @B.h@ question above, we ensure that
673 @A.hi@ is touched (even if identical to its previous version) if A's
674 recompilation was triggered by an imported @.hi@ file date change.
675 Given that, there's no need to record @B.f@ in @A@'s usages.
677 On the other hand, if @A@ exports @module B@, then we {\em do} count
678 @module B@ among @A@'s usages, because we must recompile @A@ to ensure
679 that @A.hi@ changes appropriately.
681 HOWEVER, we *do* record the usage
683 in A.hi, to record the fact that A does import B. This is used to decide
684 to look to look for B.hi rather than B.hi-boot when compiling a module that
685 imports A. This line says that A imports B, but uses nothing in it.
686 So we'll get an early bale-out when compiling A if B's version changes.
689 getImportVersions :: ModuleName -- Name of this module
690 -> ExportEnv -- Info about exports
691 -> RnMG (VersionInfo Name) -- Version info for these names
693 getImportVersions this_mod (ExportEnv export_avails _ export_all_mods)
694 = getIfacesRn `thenRn` \ ifaces ->
696 mod_map = iImpModInfo ifaces
697 imp_names = iVSlurp ifaces
699 export_mods :: FiniteMap ModuleName () -- Set of home modules for
700 -- things in the export list
701 export_mods = listToFM [(moduleName (nameModule (availName a)), ()) | a <- export_avails]
703 -- mv_map groups together all the things imported from a particular module.
704 mv_map :: FiniteMap ModuleName [(Name,Version)]
705 mv_map = foldr add_mv emptyFM imp_names
707 -- Build the result list by adding info for each module.
708 -- For (a) a library module, we don't record it at all unless it contains orphans
709 -- (We must never lose track of orphans.)
711 -- (b) a source-imported module, don't record the dependency at all
713 -- (b) may seem a bit strange. The idea is that the usages in a .hi file records
714 -- *all* the module's dependencies other than the loop-breakers. We use
715 -- this info in findAndReadInterface to decide whether to look for a .hi file or
718 -- This means we won't track version changes, or orphans, from .hi-boot files.
719 -- The former is potentially rather bad news. It could be fixed by recording
720 -- whether something is a boot file along with the usage info for it, but
721 -- I can't be bothered just now.
723 mk_version_info mod_name (version, has_orphans, Nothing) so_far
724 = ASSERT( not has_orphans ) -- If has_orphans is true we will have opened it
725 so_far -- We didn't even read this module's interface
726 -- so don't record dependency on it.
728 mk_version_info mod_name (version, has_orphans, Just (mod, boot_import, _)) so_far
729 | boot_import -- Don't record any usage info for this module
730 || (is_lib_module && not has_orphans)
733 | is_lib_module -- Record the module but not
734 || mod_name `elem` export_all_mods -- detailed version information for the imports
735 = go_for_it Everything
738 = case lookupFM mv_map mod_name of
740 -> go_for_it (Specifically whats_imported)
742 Nothing -- This happens if you have
744 -- but don't actually *use* anything from Foo
745 | has_orphans -- Check for (a) orphans (we must never forget them)
746 || mod_name `elemFM` export_mods -- or (b) something from the module is exported
747 -> -- ...in which case record an empty dependency list
748 go_for_it (Specifically [])
750 | otherwise -> so_far -- No point in recording any dependency
752 is_lib_module = isLibModule mod
753 go_for_it exports = (mod_name, version, has_orphans, exports) : so_far
756 -- A module shouldn't load its own interface
757 -- This seems like a convenient place to check
758 WARN( maybeToBool (lookupFM mod_map this_mod),
759 ptext SLIT("Wierd:") <+> ppr this_mod <+> ptext SLIT("loads its own interface") )
761 returnRn (foldFM mk_version_info [] mod_map)
763 add_mv v@(name, version) mv_map
764 = addToFM_C add_item mv_map mod [v]
766 mod = moduleName (nameModule name)
767 add_item vs _ = (v:vs)
772 = getIfacesRn `thenRn` \ ifaces ->
773 returnRn (iSlurp ifaces)
775 recordSlurp maybe_version avail
776 = getIfacesRn `thenRn` \ ifaces@(Ifaces { iSlurp = slurped_names,
777 iVSlurp = imp_names }) ->
779 new_slurped_names = addAvailToNameSet slurped_names avail
781 new_imp_names = case maybe_version of
782 Just version -> (availName avail, version) : imp_names
785 setIfacesRn (ifaces { iSlurp = new_slurped_names,
786 iVSlurp = new_imp_names })
790 %*********************************************************
792 \subsection{Getting binders out of a declaration}
794 %*********************************************************
796 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
797 It's used for both source code (from @availsFromDecl@) and interface files
800 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
801 are handled by the sourc-code specific stuff in @RnNames@.
804 getDeclBinders :: (RdrName -> SrcLoc -> RnM d Name) -- New-name function
806 -> RnM d (Maybe AvailInfo)
808 getDeclBinders new_name (TyClD (TyData _ _ tycon _ condecls _ _ src_loc))
809 = new_name tycon src_loc `thenRn` \ tycon_name ->
810 getConFieldNames new_name condecls `thenRn` \ sub_names ->
811 returnRn (Just (AvailTC tycon_name (tycon_name : nub sub_names)))
812 -- The "nub" is because getConFieldNames can legitimately return duplicates,
813 -- when a record declaration has the same field in multiple constructors
815 getDeclBinders new_name (TyClD (TySynonym tycon _ _ src_loc))
816 = new_name tycon src_loc `thenRn` \ tycon_name ->
817 returnRn (Just (AvailTC tycon_name [tycon_name]))
819 getDeclBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ _ _ _ src_loc))
820 = new_name cname src_loc `thenRn` \ class_name ->
822 -- Record the names for the class ops
824 -- just want class-op sigs
825 op_sigs = filter isClassOpSig sigs
827 mapRn (getClassOpNames new_name) op_sigs `thenRn` \ sub_names ->
829 returnRn (Just (AvailTC class_name (class_name : sub_names)))
831 getDeclBinders new_name (SigD (IfaceSig var ty prags src_loc))
832 = new_name var src_loc `thenRn` \ var_name ->
833 returnRn (Just (Avail var_name))
835 getDeclBinders new_name (FixD _) = returnRn Nothing
837 -- foreign declarations
838 getDeclBinders new_name (ForD (ForeignDecl nm kind _ dyn _ loc))
839 | binds_haskell_name kind dyn
840 = new_name nm loc `thenRn` \ name ->
841 returnRn (Just (Avail name))
843 | otherwise -- a foreign export
844 = lookupImplicitOccRn nm `thenRn_`
847 getDeclBinders new_name (DefD _) = returnRn Nothing
848 getDeclBinders new_name (InstD _) = returnRn Nothing
849 getDeclBinders new_name (RuleD _) = returnRn Nothing
851 binds_haskell_name (FoImport _) _ = True
852 binds_haskell_name FoLabel _ = True
853 binds_haskell_name FoExport ext_nm = isDynamic ext_nm
856 getConFieldNames new_name (ConDecl con _ _ (RecCon fielddecls) src_loc : rest)
857 = mapRn (\n -> new_name n src_loc) (con:fields) `thenRn` \ cfs ->
858 getConFieldNames new_name rest `thenRn` \ ns ->
861 fields = concat (map fst fielddecls)
863 getConFieldNames new_name (ConDecl con _ _ condecl src_loc : rest)
864 = new_name con src_loc `thenRn` \ n ->
867 new_name f src_loc `thenRn` \ new_f ->
869 _ -> returnRn [n]) `thenRn` \ nn ->
870 getConFieldNames new_name rest `thenRn` \ ns ->
873 getConFieldNames new_name [] = returnRn []
875 getClassOpNames new_name (ClassOpSig op _ _ _ src_loc) = new_name op src_loc
878 @getDeclSysBinders@ gets the implicit binders introduced by a decl.
879 A the moment that's just the tycon and datacon that come with a class decl.
880 They aren't returned by @getDeclBinders@ because they aren't in scope;
881 but they {\em should} be put into the @DeclsMap@ of this module.
883 Note that this excludes the default-method names of a class decl,
884 and the dict fun of an instance decl, because both of these have
885 bindings of their own elsewhere.
888 getDeclSysBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ tname dname snames src_loc))
889 = new_name dname src_loc `thenRn` \ datacon_name ->
890 new_name tname src_loc `thenRn` \ tycon_name ->
891 sequenceRn [new_name n src_loc | n <- snames] `thenRn` \ scsel_names ->
892 returnRn (tycon_name : datacon_name : scsel_names)
894 getDeclSysBinders new_name other_decl
898 %*********************************************************
900 \subsection{Reading an interface file}
902 %*********************************************************
905 findAndReadIface :: SDoc -> ModuleName -> WhereFrom
906 -> Bool -- Only relevant for SystemImport
907 -- True <=> Look for a .hi file
908 -- False <=> Look for .hi-boot file unless there's
909 -- a library .hi file
910 -> RnM d (Bool, Maybe (Module, ParsedIface))
911 -- Bool is True if the interface actually read was a .hi-boot one
912 -- Nothing <=> file not found, or unreadable, or illegible
913 -- Just x <=> successfully found and parsed
915 findAndReadIface doc_str mod_name from hi_file
916 = traceRn trace_msg `thenRn_`
917 -- we keep two maps for interface files,
918 -- one for 'normal' ones, the other for .hi-boot files,
919 -- hence the need to signal which kind we're interested.
921 getHiMaps `thenRn` \ hi_maps ->
923 case find_path from hi_maps of
925 (hi_boot, Just (fpath, mod)) -> traceRn (ptext SLIT("...reading from") <+> text fpath)
927 readIface mod fpath `thenRn` \ result ->
928 returnRn (hi_boot, result)
929 (hi_boot, Nothing) -> traceRn (ptext SLIT("...not found")) `thenRn_`
930 returnRn (hi_boot, Nothing)
932 find_path ImportByUser (hi_map, _) = (False, lookupFM hi_map mod_name)
933 find_path ImportByUserSource (_, hiboot_map) = (True, lookupFM hiboot_map mod_name)
935 find_path ImportBySystem (hi_map, hiboot_map)
937 = -- If the module we seek is in our dependent set,
938 -- Look for a .hi file
939 (False, lookupFM hi_map mod_name)
942 -- Check if there's a library module of that name
943 -- If not, look for an hi-boot file
944 = case lookupFM hi_map mod_name of
945 stuff@(Just (_, mod)) | isLibModule mod -> (False, stuff)
946 other -> (True, lookupFM hiboot_map mod_name)
948 trace_msg = sep [hsep [ptext SLIT("Reading"),
950 ptext SLIT("interface for"),
951 pprModuleName mod_name <> semi],
952 nest 4 (ptext SLIT("reason:") <+> doc_str)]
955 @readIface@ tries just the one file.
958 readIface :: Module -> String -> RnM d (Maybe (Module, ParsedIface))
959 -- Nothing <=> file not found, or unreadable, or illegible
960 -- Just x <=> successfully found and parsed
961 readIface the_mod file_path
962 = ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
965 case parseIface contents
966 PState{ bol = 0#, atbol = 1#,
969 loc = mkSrcLoc (mkFastString file_path) 1 } of
970 PFailed err -> failWithRn Nothing err
971 POk _ (PIface mod_nm iface) ->
972 warnCheckRn (mod_nm == moduleName the_mod)
973 (hiModuleNameMismatchWarn the_mod mod_nm) `thenRn_`
974 returnRn (Just (the_mod, iface))
977 | isDoesNotExistError err -> returnRn Nothing
978 | otherwise -> failWithRn Nothing (cannaeReadFile file_path err)
981 %*********************************************************
985 %*********************************************************
988 noIfaceErr filename boot_file
989 = hsep [ptext SLIT("Could not find valid"), boot,
990 ptext SLIT("interface file"), quotes (pprModule filename)]
992 boot | boot_file = ptext SLIT("[boot]")
995 cannaeReadFile file err
996 = hcat [ptext SLIT("Failed in reading file: "),
998 ptext SLIT("; error="),
1002 = ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name)
1004 getDeclWarn name loc
1005 = sep [ptext SLIT("Failed to find (optional) interface decl for") <+> quotes (ppr name),
1006 ptext SLIT("desired at") <+> ppr loc]
1010 "Compiler tried to import decl from interface file with same name as module."),
1012 "(possible cause: module name clashes with interface file already in scope.)")
1014 hsep [ptext SLIT("name:"), quotes (ppr name)]
1016 warnRedundantSourceImport mod_name
1017 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
1018 <+> quotes (pprModuleName mod_name)
1020 hiModuleNameMismatchWarn :: Module -> ModuleName -> Message
1021 hiModuleNameMismatchWarn requested_mod mod_nm =
1022 hsep [ ptext SLIT("Something is amiss; requested module name")
1023 , pprModule requested_mod
1024 , ptext SLIT("differs from name found in the interface file ")
1025 , pprModuleName mod_nm