2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[RnIfaces]{Cacheing and Renaming of Interfaces}
10 getSpecialInstModules, getDeferredDataDecls,
11 importDecl, recordSlurp,
12 getImportVersions, getSlurpedNames, getRnStats,
20 #include "HsVersions.h"
22 import CmdLineOpts ( opt_PruneTyDecls, opt_PruneInstDecls,
23 opt_D_show_rn_imports, opt_IgnoreIfacePragmas
25 import HsSyn ( HsDecl(..), TyDecl(..), ClassDecl(..), InstDecl(..), IfaceSig(..),
26 HsType(..), ConDecl(..), IE(..), ConDetails(..), Sig(..),
29 import BasicTypes ( Version, NewOrData(..), IfaceFlavour(..) )
30 import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameTyDecl,
31 RdrName(..), rdrNameOcc
33 import RnEnv ( newImportedGlobalName, addImplicitOccsRn,
34 ifaceFlavour, availName, availNames, addAvailToNameSet
36 import RnSource ( rnHsSigType )
38 import RnHsSyn ( RenamedHsDecl )
39 import ParseIface ( parseIface, IfaceStuff(..) )
41 import FiniteMap ( FiniteMap, sizeFM, emptyFM, delFromFM,
42 lookupFM, addToFM, addToFM_C, addListToFM,
45 import Name ( Name {-instance NamedThing-}, OccName(..),
46 nameModule, moduleString, pprModule, isLocallyDefined,
47 isWiredInName, maybeWiredInTyConName,
48 maybeWiredInIdName, nameUnique, NamedThing(..)
51 import Id ( idType, isDataConId_maybe )
52 import DataCon ( dataConTyCon, dataConType )
53 import TyCon ( TyCon, tyConDataCons, isSynTyCon, getSynTyConDefn )
54 import Type ( namesOfType )
56 import SrcLoc ( mkSrcLoc, SrcLoc )
57 import PrelMods ( pREL_GHC )
58 import PrelInfo ( cCallishTyKeys, thinAirModules )
60 import Maybes ( MaybeErr(..), maybeToBool )
61 import ListSetOps ( unionLists )
63 import Unique ( Unique )
64 import StringBuffer ( StringBuffer, hGetStringBuffer )
65 import FastString ( mkFastString )
68 import IO ( isDoesNotExistError )
75 %*********************************************************
77 \subsection{Statistics}
79 %*********************************************************
82 getRnStats :: [RenamedHsDecl] -> RnMG SDoc
84 = getIfacesRn `thenRn` \ ifaces ->
86 Ifaces this_mod mod_map decls_fm all_names imp_names (unslurped_insts,_) deferred_data_decls inst_mods = ifaces
87 n_mods = sizeFM mod_map
89 decls_imported = filter is_imported_decl all_decls
90 decls_read = [decl | (name, (_, avail, decl)) <- fmToList decls_fm,
91 name == availName avail,
92 -- Data, newtype, and class decls are in the decls_fm
93 -- under multiple names; the tycon/class, and each
94 -- constructor/class op too.
95 not (isLocallyDefined name)
98 (cd_rd, dd_rd, add_rd, nd_rd, and_rd, sd_rd, vd_rd, _) = count_decls decls_read
99 (cd_sp, dd_sp, add_sp, nd_sp, and_sp, sd_sp, vd_sp, id_sp) = count_decls decls_imported
101 inst_decls_unslurped = length (bagToList unslurped_insts)
102 inst_decls_read = id_sp + inst_decls_unslurped
105 [int n_mods <> text " interfaces read",
106 hsep [int cd_sp, text "class decls imported, out of",
107 int cd_rd, text "read"],
108 hsep [int dd_sp, text "data decls imported (of which", int add_sp, text "abstractly), out of",
109 int dd_rd, text "read"],
110 hsep [int nd_sp, text "newtype decls imported (of which", int and_sp, text "abstractly), out of",
111 int nd_rd, text "read"],
112 hsep [int sd_sp, text "type synonym decls imported, out of",
113 int sd_rd, text "read"],
114 hsep [int vd_sp, text "value signatures imported, out of",
115 int vd_rd, text "read"],
116 hsep [int id_sp, text "instance decls imported, out of",
117 int inst_decls_read, text "read"]
120 returnRn (hcat [text "Renamer stats: ", stats])
122 is_imported_decl (DefD _) = False
123 is_imported_decl (ValD _) = False
124 is_imported_decl decl = not (isLocallyDefined (hsDeclName decl))
127 = -- pprTrace "count_decls" (ppr decls
132 -- ppr imported_decls
135 data_decls, abstract_data_decls,
136 newtype_decls, abstract_newtype_decls,
141 class_decls = length [() | ClD _ <- decls]
142 data_decls = length [() | TyD (TyData DataType _ _ _ _ _ _ _) <- decls]
143 newtype_decls = length [() | TyD (TyData NewType _ _ _ _ _ _ _) <- decls]
144 abstract_data_decls = length [() | TyD (TyData DataType _ _ _ [] _ _ _) <- decls]
145 abstract_newtype_decls = length [() | TyD (TyData NewType _ _ _ [] _ _ _) <- decls]
146 syn_decls = length [() | TyD (TySynonym _ _ _ _) <- decls]
147 val_decls = length [() | SigD _ <- decls]
148 inst_decls = length [() | InstD _ <- decls]
152 %*********************************************************
154 \subsection{Loading a new interface file}
156 %*********************************************************
159 loadInterface :: SDoc -> Module -> IfaceFlavour -> RnMG Ifaces
160 loadInterface doc_str load_mod as_source
161 = getIfacesRn `thenRn` \ ifaces ->
163 Ifaces this_mod mod_map decls
164 all_names imp_names (insts, tycls_names)
165 deferred_data_decls inst_mods = ifaces
167 -- CHECK WHETHER WE HAVE IT ALREADY
168 case lookupFM mod_map load_mod of {
169 Just (hif, _, _, _) | hif `as_good_as` as_source
170 -> -- Already in the cache; don't re-read it
174 -- READ THE MODULE IN
175 findAndReadIface doc_str load_mod as_source `thenRn` \ read_result ->
176 case read_result of {
177 -- Check for not found
178 Nothing -> -- Not found, so add an empty export env to the Ifaces map
179 -- so that we don't look again
181 new_mod_map = addToFM mod_map load_mod (HiFile, 0, [],[])
182 new_ifaces = Ifaces this_mod new_mod_map
183 decls all_names imp_names (insts, tycls_names)
184 deferred_data_decls inst_mods
186 setIfacesRn new_ifaces `thenRn_`
187 failWithRn new_ifaces (noIfaceErr load_mod) ;
190 Just (ParsedIface _ mod_vers usages exports rd_inst_mods fixs rd_decls rd_insts) ->
192 -- LOAD IT INTO Ifaces
193 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
194 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
195 -- If we do loadExport first the wrong info gets into the cache (unless we
196 -- explicitly tag each export which seems a bit of a bore)
197 foldlRn (loadDecl load_mod as_source) decls rd_decls `thenRn` \ new_decls ->
198 mapRn loadExport exports `thenRn` \ avails_s ->
199 foldlRn (loadInstDecl load_mod) insts rd_insts `thenRn` \ new_insts ->
201 mod_details = (as_source, mod_vers, concat avails_s, fixs)
203 -- Exclude this module from the "special-inst" modules
204 new_inst_mods = inst_mods `unionLists` (filter (/= this_mod) rd_inst_mods)
206 new_ifaces = Ifaces this_mod
207 (addToFM mod_map load_mod mod_details)
210 (new_insts, tycls_names)
214 setIfacesRn new_ifaces `thenRn_`
218 as_good_as HiFile any = True
219 as_good_as any HiBootFile = True
220 as_good_as _ _ = False
223 loadExport :: ExportItem -> RnMG [AvailInfo]
224 loadExport (mod, hif, entities)
225 = mapRn load_entity entities
227 new_name occ = newImportedGlobalName mod occ hif
229 load_entity (Avail occ)
230 = new_name occ `thenRn` \ name ->
231 returnRn (Avail name)
232 load_entity (AvailTC occ occs)
233 = new_name occ `thenRn` \ name ->
234 mapRn new_name occs `thenRn` \ names ->
235 returnRn (AvailTC name names)
240 -> (Version, RdrNameHsDecl)
242 loadDecl mod as_source decls_map (version, decl)
243 = getDeclBinders new_implicit_name decl `thenRn` \ avail ->
244 returnRn (addListToFM decls_map
245 [(name,(version,avail,decl')) | name <- availNames avail]
249 If a signature decl is being loaded and we're ignoring interface pragmas,
250 toss away unfolding information.
252 Also, if the signature is loaded from a module we're importing from source,
253 we do the same. This is to avoid situations when compiling a pair of mutually
254 recursive modules, peering at unfolding info in the interface file of the other,
255 e.g., you compile A, it looks at B's interface file and may as a result change
256 it's interface file. Hence, B is recompiled, maybe changing it's interface file,
257 which will the ufolding info used in A to become invalid. Simple way out is to
258 just ignore unfolding info.
262 SigD (IfaceSig name tp ls loc) | from_hi_boot || opt_IgnoreIfacePragmas ->
263 SigD (IfaceSig name tp [] loc)
266 new_implicit_name rdr_name loc = newImportedGlobalName mod (rdrNameOcc rdr_name) as_source
268 from_hi_boot = case as_source of
272 loadInstDecl :: Module
275 -> RnMG (Bag IfaceInst)
276 loadInstDecl mod_name insts decl@(InstDecl inst_ty binds uprags dfun_name src_loc)
278 -- Find out what type constructors and classes are "gates" for the
279 -- instance declaration. If all these "gates" are slurped in then
280 -- we should slurp the instance decl too.
282 -- We *don't* want to count names in the context part as gates, though.
284 -- instance Foo a => Baz (T a) where ...
286 -- Here the gates are Baz and T, but *not* Foo.
288 munged_inst_ty = case inst_ty of
289 HsForAllTy tvs cxt ty -> HsForAllTy tvs [] ty
292 -- We find the gates by renaming the instance type with in a
293 -- and returning the occurrence pool.
294 initRnMS emptyRnEnv mod_name vanillaInterfaceMode (
295 findOccurrencesRn (rnHsSigType (text "an instance decl") munged_inst_ty)
296 ) `thenRn` \ gate_names ->
297 returnRn (((mod_name, decl), gate_names) `consBag` insts)
299 vanillaInterfaceMode = InterfaceMode Compulsory (\_ -> False)
303 %********************************************************
305 \subsection{Loading usage information}
307 %********************************************************
310 checkUpToDate :: Module -> RnMG Bool -- True <=> no need to recompile
311 checkUpToDate mod_name
312 = findAndReadIface doc_str mod_name HiFile `thenRn` \ read_result ->
314 -- CHECK WHETHER WE HAVE IT ALREADY
316 Nothing -> -- Old interface file not found, so we'd better bail out
317 traceRn (sep [ptext SLIT("Didnt find old iface"),
318 pprModule mod_name]) `thenRn_`
321 Just (ParsedIface _ _ usages _ _ _ _ _)
322 -> -- Found it, so now check it
325 -- Only look in current directory, with suffix .hi
326 doc_str = sep [ptext SLIT("need usage info from"), pprModule mod_name]
328 checkModUsage [] = returnRn True -- Yes! Everything is up to date!
330 checkModUsage ((mod, hif, old_mod_vers, whats_imported) : rest)
331 = loadInterface doc_str mod hif `thenRn` \ ifaces ->
333 Ifaces _ mod_map decls _ _ _ _ _ = ifaces
334 maybe_new_mod_vers = lookupFM mod_map mod
335 Just (_, new_mod_vers, _, _) = maybe_new_mod_vers
337 -- If we can't find a version number for the old module then
338 -- bail out saying things aren't up to date
339 if not (maybeToBool maybe_new_mod_vers) then
340 traceRn (sep [ptext SLIT("Can't find version number for module"), pprModule mod]) `thenRn_`
344 -- If the module version hasn't changed, just move on
345 if new_mod_vers == old_mod_vers then
346 traceRn (sep [ptext SLIT("Module version unchanged:"), pprModule mod]) `thenRn_`
349 traceRn (sep [ptext SLIT("Module version has changed:"), pprModule mod]) `thenRn_`
351 -- Module version changed, so check entities inside
353 -- If the usage info wants to say "I imported everything from this module"
354 -- it does so by making whats_imported equal to Everything
355 -- In that case, we must recompile
356 case whats_imported of {
357 Everything -> traceRn (ptext SLIT("...and I needed the whole module")) `thenRn_`
358 returnRn False; -- Bale out
360 Specifically old_local_vers ->
362 -- Non-empty usage list, so check item by item
363 checkEntityUsage mod decls old_local_vers `thenRn` \ up_to_date ->
365 traceRn (ptext SLIT("...but the bits I use haven't.")) `thenRn_`
366 checkModUsage rest -- This one's ok, so check the rest
368 returnRn False -- This one failed, so just bail out now
371 doc_str = sep [ptext SLIT("need version info for"), pprModule mod]
374 checkEntityUsage mod decls []
375 = returnRn True -- Yes! All up to date!
377 checkEntityUsage mod decls ((occ_name,old_vers) : rest)
378 = newImportedGlobalName mod occ_name HiFile `thenRn` \ name ->
379 case lookupFM decls name of
381 Nothing -> -- We used it before, but it ain't there now
382 putDocRn (sep [ptext SLIT("No longer exported:"), ppr name]) `thenRn_`
385 Just (new_vers,_,_) -- It's there, but is it up to date?
386 | new_vers == old_vers
387 -- Up to date, so check the rest
388 -> checkEntityUsage mod decls rest
391 -- Out of date, so bale out
392 -> putDocRn (sep [ptext SLIT("Out of date:"), ppr name]) `thenRn_`
397 %*********************************************************
399 \subsection{Getting in a declaration}
401 %*********************************************************
404 importDecl :: Occurrence -> RnSMode -> RnMG (Maybe RdrNameHsDecl)
405 -- Returns Nothing for a wired-in or already-slurped decl
407 importDecl (name, loc) mode
408 = checkSlurped name `thenRn` \ already_slurped ->
409 if already_slurped then
410 -- traceRn (sep [text "Already slurped:", ppr name]) `thenRn_`
411 returnRn Nothing -- Already dealt with
413 if isWiredInName name then
414 getWiredInDecl name mode
416 getIfacesRn `thenRn` \ ifaces ->
418 Ifaces this_mod _ _ _ _ _ _ _ = ifaces
419 mod = nameModule name
421 if mod == this_mod then -- Don't bring in decls from
422 addWarnRn (importDeclWarn mod name loc) `thenRn_`
423 -- pprTrace "importDecl wierdness:" (ppr name) $
424 returnRn Nothing -- the renamed module's own interface file
427 getNonWiredInDecl name loc mode
431 getNonWiredInDecl :: Name -> SrcLoc -> RnSMode -> RnMG (Maybe RdrNameHsDecl)
432 getNonWiredInDecl needed_name loc mode
433 = traceRn doc_str `thenRn_`
434 loadInterface doc_str mod (ifaceFlavour needed_name) `thenRn` \ (Ifaces _ _ decls _ _ _ _ _) ->
435 case lookupFM decls needed_name of
437 -- Special case for data/newtype type declarations
438 Just (version, avail, TyD ty_decl) | is_data_or_newtype ty_decl
439 -> getNonWiredDataDecl needed_name version avail ty_decl `thenRn` \ (avail', maybe_decl) ->
440 recordSlurp (Just version) necessity avail' `thenRn_`
443 Just (version,avail,decl)
444 -> recordSlurp (Just version) necessity avail `thenRn_`
447 Nothing -> -- Can happen legitimately for "Optional" occurrences
449 Optional -> addWarnRn (getDeclWarn needed_name loc);
450 other -> addErrRn (getDeclErr needed_name loc)
454 necessity = modeToNecessity mode
455 doc_str = sep [ptext SLIT("need decl for"), ppr needed_name, ptext SLIT("needed at"), ppr loc]
456 mod = nameModule needed_name
458 is_data_or_newtype (TyData _ _ _ _ _ _ _ _) = True
459 is_data_or_newtype other = False
462 @getWiredInDecl@ maps a wired-in @Name@ to what it makes available.
463 It behaves exactly as if the wired in decl were actually in an interface file.
466 * if the wired-in name is a data type constructor or a data constructor,
467 it brings in the type constructor and all the data constructors; and
468 marks as "occurrences" any free vars of the data con.
470 * similarly for synonum type constructor
472 * if the wired-in name is another wired-in Id, it marks as "occurrences"
473 the free vars of the Id's type.
475 * it loads the interface file for the wired-in thing for the
476 sole purpose of making sure that its instance declarations are available
478 All this is necessary so that we know all types that are "in play", so
479 that we know just what instances to bring into scope.
482 getWiredInDecl name mode
483 = initRnMS emptyRnEnv mod_name new_mode
484 get_wired `thenRn` \ avail ->
485 recordSlurp Nothing necessity avail `thenRn_`
487 -- Force in the home module in case it has instance decls for
488 -- the thing we are interested in.
490 -- Mini hack 1: no point for non-tycons/class; and if we
491 -- do this we find PrelNum trying to import PackedString,
492 -- because PrelBase's .hi file mentions PackedString.unpackString
493 -- But PackedString.hi isn't built by that point!
495 -- Mini hack 2; GHC is guaranteed not to have
496 -- instance decls, so it's a waste of time to read it
498 -- NB: We *must* look at the availName of the slurped avail,
499 -- not the name passed to getWiredInDecl! Why? Because if a data constructor
500 -- or class op is passed to getWiredInDecl we'll pull in the whole data/class
501 -- decl, and recordSlurp will record that fact. But since the data constructor
502 -- isn't a tycon/class we won't force in the home module. And even if the
503 -- type constructor/class comes along later, loadDecl will say that it's already
504 -- been slurped, so getWiredInDecl won't even be called. Pretty obscure bug, this was.
506 main_name = availName avail
507 main_is_tc = case avail of { AvailTC _ _ -> True; Avail _ -> False }
508 mod = nameModule main_name
509 doc_str = sep [ptext SLIT("need home module for wired in thing"), ppr name]
511 (if not main_is_tc || mod == pREL_GHC then
514 loadInterface doc_str mod (ifaceFlavour main_name) `thenRn_`
518 returnRn Nothing -- No declaration to process further
520 necessity = modeToNecessity mode
521 new_mode = case mode of
522 InterfaceMode _ _ -> mode
523 SourceMode -> vanillaInterfaceMode
525 get_wired | is_tycon -- ... a type constructor
526 = get_wired_tycon the_tycon
528 | maybeToBool maybe_data_con -- ... a wired-in data constructor
529 = get_wired_tycon (dataConTyCon data_con)
531 | otherwise -- ... a wired-in non data-constructor
532 = get_wired_id the_id
534 mod_name = nameModule name
535 maybe_wired_in_tycon = maybeWiredInTyConName name
536 is_tycon = maybeToBool maybe_wired_in_tycon
537 maybe_wired_in_id = maybeWiredInIdName name
538 Just the_tycon = maybe_wired_in_tycon
539 Just the_id = maybe_wired_in_id
540 maybe_data_con = isDataConId_maybe the_id
541 Just data_con = maybe_data_con
545 = addImplicitOccsRn id_mentions `thenRn_`
546 returnRn (Avail (getName id))
548 id_mentions = nameSetToList (namesOfType ty)
551 get_wired_tycon tycon
553 = addImplicitOccsRn (nameSetToList mentioned) `thenRn_`
554 returnRn (AvailTC tc_name [tc_name])
556 tc_name = getName tycon
557 (tyvars,ty) = getSynTyConDefn tycon
558 mentioned = namesOfType ty `minusNameSet` mkNameSet (map getName tyvars)
560 get_wired_tycon tycon
561 | otherwise -- data or newtype
562 = addImplicitOccsRn (nameSetToList mentioned) `thenRn_`
563 returnRn (AvailTC tycon_name (tycon_name : map getName data_cons))
565 tycon_name = getName tycon
566 data_cons = tyConDataCons tycon
567 mentioned = foldr (unionNameSets . namesOfType . dataConType) emptyNameSet data_cons
572 %*********************************************************
574 \subsection{Getting what a module exports}
576 %*********************************************************
579 getInterfaceExports :: Module -> IfaceFlavour -> RnMG (Avails, [(OccName,Fixity)])
580 getInterfaceExports mod as_source
581 = loadInterface doc_str mod as_source `thenRn` \ (Ifaces _ mod_map _ _ _ _ _ _) ->
582 case lookupFM mod_map mod of
583 Nothing -> -- Not there; it must be that the interface file wasn't found;
584 -- the error will have been reported already.
585 -- (Actually loadInterface should put the empty export env in there
586 -- anyway, but this does no harm.)
589 Just (_, _, avails, fixities) -> returnRn (avails, fixities)
591 doc_str = sep [pprModule mod, ptext SLIT("is directly imported")]
595 %*********************************************************
597 \subsection{Data type declarations are handled specially}
599 %*********************************************************
601 Data type declarations get special treatment. If we import a data type decl
602 with all its constructors, we end up importing all the types mentioned in
603 the constructors' signatures, and hence {\em their} data type decls, and so on.
604 In effect, we get the transitive closure of data type decls. Worse, this drags
605 in tons on instance decls, and their unfoldings, and so on.
607 If only the type constructor is mentioned, then all this is a waste of time.
608 If any of the data constructors are mentioned then we really have to
609 drag in the whole declaration.
611 So when we import the type constructor for a @data@ or @newtype@ decl, we
612 put it in the "deferred data/newtype decl" pile in Ifaces. Right at the end
613 we slurp these decls, if they havn't already been dragged in by an occurrence
617 getNonWiredDataDecl needed_name
619 avail@(AvailTC tycon_name _)
620 ty_decl@(TyData new_or_data context tycon tyvars condecls derivings pragmas src_loc)
621 | needed_name == tycon_name
623 -- don't prune newtypes, as the code generator may
624 -- want to peer inside a newtype type constructor
625 -- (ClosureInfo.fun_result_ty is the culprit.)
626 && not (new_or_data == NewType)
627 && not (nameUnique needed_name `elem` cCallishTyKeys)
628 -- Hack! Don't prune these tycons whose constructors
629 -- the desugarer must be able to see when desugaring
632 = -- Need the type constructor; so put it in the deferred set for now
633 getIfacesRn `thenRn` \ ifaces ->
635 Ifaces this_mod mod_map decls_fm slurped_names imp_names
636 unslurped_insts deferred_data_decls inst_mods = ifaces
638 new_ifaces = Ifaces this_mod mod_map decls_fm slurped_names imp_names
639 unslurped_insts new_deferred_data_decls inst_mods
641 no_constr_ty_decl = TyData new_or_data [] tycon tyvars [] derivings pragmas src_loc
642 new_deferred_data_decls = addToFM deferred_data_decls tycon_name no_constr_ty_decl
643 -- Nota bene: we nuke both the constructors and the context in the deferred decl.
644 -- If we don't nuke the context then renaming the deferred data decls can give
645 -- new unresolved names (for the classes). This could be handled, but there's
646 -- no point. If the data type is completely abstract then we aren't interested
649 setIfacesRn new_ifaces `thenRn_`
650 returnRn (AvailTC tycon_name [tycon_name], Nothing)
653 = -- Need a data constructor, so delete the data decl from the deferred set if it's there
654 getIfacesRn `thenRn` \ ifaces ->
656 Ifaces this_mod mod_map decls_fm slurped_names imp_names
657 unslurped_insts deferred_data_decls inst_mods = ifaces
659 new_ifaces = Ifaces this_mod mod_map decls_fm slurped_names imp_names
660 unslurped_insts new_deferred_data_decls inst_mods
662 new_deferred_data_decls = delFromFM deferred_data_decls tycon_name
664 setIfacesRn new_ifaces `thenRn_`
665 returnRn (avail, Just (TyD ty_decl))
669 getDeferredDataDecls :: RnMG [(Name, RdrNameTyDecl)]
671 = getIfacesRn `thenRn` \ (Ifaces _ _ _ _ _ _ deferred_data_decls _) ->
673 deferred_list = fmToList deferred_data_decls
674 trace_msg = hang (text "Slurping abstract data/newtype decls for: ")
675 4 (ppr (map fst deferred_list))
677 traceRn trace_msg `thenRn_`
678 returnRn deferred_list
682 %*********************************************************
684 \subsection{Instance declarations are handled specially}
686 %*********************************************************
689 getImportedInstDecls :: RnMG [(Module,RdrNameInstDecl)]
691 = -- First load any special-instance modules that aren't aready loaded
692 getSpecialInstModules `thenRn` \ inst_mods ->
693 mapRn load_it inst_mods `thenRn_`
695 -- Now we're ready to grab the instance declarations
696 -- Find the un-gated ones and return them,
697 -- removing them from the bag kept in Ifaces
698 getIfacesRn `thenRn` \ ifaces ->
700 Ifaces this_mod mod_map decls slurped_names imp_names (insts, tycls_names) deferred_data_decls inst_mods = ifaces
702 -- An instance decl is ungated if all its gates have been slurped
703 select_ungated :: IfaceInst -- A gated inst decl
705 -> ([(Module, RdrNameInstDecl)], [IfaceInst]) -- Accumulator
707 -> ([(Module, RdrNameInstDecl)], -- The ungated ones
708 [IfaceInst]) -- Still gated, but with
710 select_ungated (decl,gates) (ungated_decls, gated_decls)
711 | null remaining_gates
712 = (decl : ungated_decls, gated_decls)
714 = (ungated_decls, (decl, remaining_gates) : gated_decls)
716 remaining_gates = filter (not . (`elemNameSet` tycls_names)) gates
718 (un_gated_insts, still_gated_insts) = foldrBag select_ungated ([], []) insts
720 new_ifaces = Ifaces this_mod mod_map decls slurped_names imp_names
721 ((listToBag still_gated_insts), tycls_names)
722 -- NB: don't throw away tycls_names; we may comre across more instance decls
726 traceRn (sep [text "getInstDecls:", fsep (map ppr (nameSetToList tycls_names))]) `thenRn_`
727 setIfacesRn new_ifaces `thenRn_`
728 returnRn un_gated_insts
730 load_it mod = loadInterface (doc_str mod) mod HiFile
731 doc_str mod = sep [pprModule mod, ptext SLIT("is a special-instance module")]
734 getSpecialInstModules :: RnMG [Module]
735 getSpecialInstModules
736 = getIfacesRn `thenRn` \ ifaces ->
738 Ifaces _ _ _ _ _ _ _ inst_mods = ifaces
744 %*********************************************************
746 \subsection{Keeping track of what we've slurped, and version numbers}
748 %*********************************************************
750 getImportVersions figures out what the "usage information" for this moudule is;
751 that is, what it must record in its interface file as the things it uses.
753 - anything reachable from its body code
754 - any module exported with a "module Foo".
756 Why the latter? Because if Foo changes then this module's export list
757 will change, so we must recompile this module at least as far as
758 making a new interface file --- but in practice that means complete
762 module A( f, g ) where module B( f ) where
763 import B( f ) f = h 3
766 Should we record B.f in A's usages? In fact we don't. Certainly, if
767 anything about B.f changes than anyone who imports A should be recompiled;
768 they'll get an early exit if they don't use B.f. However, even if B.f
769 doesn't change at all, B.h may do so, and this change may not be reflected
770 in f's version number. So there are two things going on when compiling module A:
772 1. Are A.o and A.hi correct? Then we can bale out early.
773 2. Should modules that import A be recompiled?
775 For (1) it is slightly harmful to record B.f in A's usages, because a change in
776 B.f's version will provoke full recompilation of A, producing an identical A.o,
777 and A.hi differing only in its usage-version of B.f (which isn't used by any importer).
779 For (2), because of the tricky B.h question above, we ensure that A.hi is touched
780 (even if identical to its previous version) if A's recompilation was triggered by
781 an imported .hi file date change. Given that, there's no need to record B.f in
784 On the other hand, if A exports "module B" then we *do* count module B among
785 A's usages, because we must recompile A to ensure that A.hi changes appropriately.
788 getImportVersions :: Module -- Name of this module
789 -> Maybe [IE any] -- Export list for this module
790 -> RnMG (VersionInfo Name) -- Version info for these names
792 getImportVersions this_mod exports
793 = getIfacesRn `thenRn` \ ifaces ->
795 Ifaces _ mod_map _ _ imp_names _ _ _ = ifaces
797 -- mv_map groups together all the things imported from a particular module.
798 mv_map, mv_map_mod :: FiniteMap Module (WhatsImported Name)
800 mv_map_mod = foldl add_mod emptyFM export_mods
801 -- mv_map_mod records all the modules that have a "module M"
802 -- in this module's export list with an "Everything"
804 mv_map = foldl add_mv mv_map_mod imp_names
805 -- mv_map adds the version numbers of things exported individually
807 mk_version_info (mod, local_versions)
808 = case lookupFM mod_map mod of
809 Just (hif, version, _, _) -> (mod, hif, version, local_versions)
811 returnRn (map mk_version_info (fmToList mv_map))
813 export_mods = case exports of
815 Just es -> [mod | IEModuleContents mod <- es, mod /= this_mod]
817 add_mv mv_map v@(name, version)
818 = addToFM_C add_item mv_map mod (Specifically [v])
820 mod = nameModule name
822 add_item Everything _ = Everything
823 add_item (Specifically xs) _ = Specifically (v:xs)
825 add_mod mv_map mod = addToFM mv_map mod Everything
830 = getIfacesRn `thenRn` \ (Ifaces _ _ _ slurped_names _ _ _ _) ->
831 returnRn (name `elemNameSet` slurped_names)
833 getSlurpedNames :: RnMG NameSet
835 = getIfacesRn `thenRn` \ ifaces ->
837 Ifaces _ _ _ slurped_names _ _ _ _ = ifaces
839 returnRn slurped_names
841 recordSlurp maybe_version necessity avail
842 = {- traceRn (hsep [text "Record slurp:", pprAvail avail,
843 -- NB PprForDebug prints export flag, which is too
844 -- strict; it's a knot-tied thing in RnNames
845 case necessity of {Compulsory -> text "comp"; Optional -> text "opt" } ]) `thenRn_`
847 getIfacesRn `thenRn` \ ifaces ->
849 Ifaces this_mod mod_map decls slurped_names imp_names
850 (insts, tycls_names) deferred_data_decls inst_mods = ifaces
852 new_slurped_names = addAvailToNameSet slurped_names avail
854 new_imp_names = case maybe_version of
855 Just version -> (availName avail, version) : imp_names
858 -- Add to the names that will let in instance declarations;
859 -- but only (a) if it's a type/class
860 -- (b) if it's compulsory (unless the test flag opt_PruneInstDecls is off)
861 new_tycls_names = case avail of
862 AvailTC tc _ | not opt_PruneInstDecls ||
863 case necessity of {Optional -> False; Compulsory -> True }
864 -> tycls_names `addOneToNameSet` tc
865 otherwise -> tycls_names
867 new_ifaces = Ifaces this_mod mod_map decls
870 (insts, new_tycls_names)
874 setIfacesRn new_ifaces
878 %*********************************************************
880 \subsection{Getting binders out of a declaration}
882 %*********************************************************
884 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
885 It's used for both source code (from @availsFromDecl@) and interface files
888 It doesn't deal with source-code specific things: ValD, DefD. They
889 are handled by the sourc-code specific stuff in RnNames.
892 getDeclBinders :: (RdrName -> SrcLoc -> RnMG Name) -- New-name function
896 getDeclBinders new_name (TyD (TyData _ _ tycon _ condecls _ _ src_loc))
897 = new_name tycon src_loc `thenRn` \ tycon_name ->
898 getConFieldNames new_name condecls `thenRn` \ sub_names ->
899 returnRn (AvailTC tycon_name (tycon_name : nub sub_names))
900 -- The "nub" is because getConFieldNames can legitimately return duplicates,
901 -- when a record declaration has the same field in multiple constructors
903 getDeclBinders new_name (TyD (TySynonym tycon _ _ src_loc))
904 = new_name tycon src_loc `thenRn` \ tycon_name ->
905 returnRn (AvailTC tycon_name [tycon_name])
907 getDeclBinders new_name (ClD (ClassDecl _ cname _ sigs _ _ tname dname src_loc))
908 = new_name cname src_loc `thenRn` \ class_name ->
909 new_name dname src_loc `thenRn` \ datacon_name ->
910 new_name tname src_loc `thenRn` \ tycon_name ->
912 -- Record the names for the class ops
913 mapRn (getClassOpNames new_name) sigs `thenRn` \ sub_names ->
915 returnRn (AvailTC class_name (class_name : datacon_name : tycon_name : sub_names))
917 getDeclBinders new_name (SigD (IfaceSig var ty prags src_loc))
918 = new_name var src_loc `thenRn` \ var_name ->
919 returnRn (Avail var_name)
921 getDeclBinders new_name (ForD _) = returnRn NotAvailable
922 getDeclBinders new_name (DefD _) = returnRn NotAvailable
923 getDeclBinders new_name (InstD _) = returnRn NotAvailable
926 getConFieldNames new_name (ConDecl con _ _ (RecCon fielddecls) src_loc : rest)
927 = mapRn (\n -> new_name n src_loc) (con:fields) `thenRn` \ cfs ->
928 getConFieldNames new_name rest `thenRn` \ ns ->
931 fields = concat (map fst fielddecls)
933 getConFieldNames new_name (ConDecl con _ _ _ src_loc : rest)
934 = new_name con src_loc `thenRn` \ n ->
935 getConFieldNames new_name rest `thenRn` \ ns ->
938 getConFieldNames new_name [] = returnRn []
940 getClassOpNames new_name (ClassOpSig op _ _ src_loc) = new_name op src_loc
944 %*********************************************************
946 \subsection{Reading an interface file}
948 %*********************************************************
951 findAndReadIface :: SDoc -> Module
953 -> RnMG (Maybe ParsedIface)
954 -- Nothing <=> file not found, or unreadable, or illegible
955 -- Just x <=> successfully found and parsed
956 findAndReadIface doc_str mod_name as_source
957 = traceRn trace_msg `thenRn_`
958 -- we keep two maps for interface files,
959 -- one for 'normal' ones, the other for .hi-boot files,
960 -- hence the need to signal which kind we're interested.
961 getModuleHiMap as_source `thenRn` \ himap ->
962 case (lookupFM himap (moduleString mod_name)) of
964 Just fpath -> readIface fpath
965 -- Hack alert! When compiling PrelBase we have to load the
966 -- decls for packCString# and friends; they are 'thin-air' Ids
967 -- (see PrelInfo.lhs). So if we don't find the HiFile we quietly
968 -- look for a .hi-boot file instead, and use that
969 Nothing | thinAirLoop mod_name as_source
970 -> findAndReadIface doc_str mod_name HiBootFile
972 -> traceRn (ptext SLIT("...failed")) `thenRn_`
975 thinAirLoop mod_name HiFile = mod_name `elem` thinAirModules
976 thinAirLoop mod_name hif = False
978 trace_msg = sep [hsep [ptext SLIT("Reading"),
979 case as_source of { HiBootFile -> ptext SLIT("[boot]"); other -> empty},
980 ptext SLIT("interface for"),
981 ptext mod_name <> semi],
982 nest 4 (ptext SLIT("reason:") <+> doc_str)]
985 @readIface@ tries just the one file.
988 readIface :: String -> RnMG (Maybe ParsedIface)
989 -- Nothing <=> file not found, or unreadable, or illegible
990 -- Just x <=> successfully found and parsed
992 = ioToRnMG (hGetStringBuffer file_path) `thenRn` \ read_result ->
995 case parseIface contents (mkSrcLoc (mkFastString file_path) 1) of
996 Failed err -> failWithRn Nothing err
997 Succeeded (PIface iface) ->
998 if opt_D_show_rn_imports then
999 putDocRn (hcat[ptext SLIT("Read "), text file_path]) `thenRn_`
1000 returnRn (Just iface)
1002 returnRn (Just iface)
1005 if isDoesNotExistError err then
1008 failWithRn Nothing (cannaeReadFile file_path err)
1011 %*********************************************************
1015 %*********************************************************
1017 @mkSearchPath@ takes a string consisting of a colon-separated list
1018 of directories and corresponding suffixes, and turns it into a list
1019 of (directory, suffix) pairs. For example:
1022 mkSearchPath "foo%.hi:.%.p_hi:baz%.mc_hi"
1023 = [("foo",".hi"),( ".", ".p_hi"), ("baz",".mc_hi")]
1027 mkSearchPath :: Maybe String -> SearchPath
1028 mkSearchPath Nothing = [(".",".hi")]
1029 mkSearchPath (Just s)
1034 case span (/= '%') s of
1036 case span (/= ':') rs of
1037 (hisuf,_:rest) -> (dir,hisuf):go rest
1038 (hisuf,[]) -> [(dir,hisuf)]
1041 %*********************************************************
1045 %*********************************************************
1049 = hcat [ptext SLIT("Could not find valid interface file "),
1050 quotes (pprModule filename)]
1052 cannaeReadFile file err
1053 = hcat [ptext SLIT("Failed in reading file: "),
1055 ptext SLIT("; error="),
1059 = sep [ptext SLIT("Failed to find interface decl for"),
1060 quotes (ppr name), ptext SLIT("needed at"), ppr loc]
1062 getDeclWarn name loc
1063 = sep [ptext SLIT("Failed to find (optional) interface decl for"),
1064 quotes (ppr name), ptext SLIT("desired at"), ppr loc]
1066 importDeclWarn mod name loc
1067 = sep [ptext SLIT("Compiler tried to import decl from interface file with same name as module."),
1068 ptext SLIT("(possible cause: module name clashes with interface file already in scope.)")
1070 hsep [ptext SLIT("Interface:"), quotes (pprModule mod), comma, ptext SLIT("name:"), quotes (ppr name),
1071 comma, ptext SLIT("desired at:"), ppr loc