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(..), isDynamicExtName,
26 FixitySig(..), RuleDecl(..),
27 isClassOpSig, Deprecation(..)
29 import BasicTypes ( Version, NewOrData(..), defaultFixity )
30 import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameTyClDecl, RdrNameRuleDecl,
31 extractHsTyRdrNames, RdrNameDeprecation
33 import RnEnv ( mkImportedGlobalName, newImportedBinder, mkImportedGlobalFromRdrName,
34 lookupOccRn, lookupImplicitOccRn,
36 availName, availNames, addAvailToNameSet, addSysAvails,
40 import RnHsSyn ( RenamedHsDecl, RenamedDeprecation )
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, isLocalModule,
54 ModuleName, WhereFrom(..),
56 import RdrName ( RdrName, rdrNameOcc )
59 import SrcLoc ( mkSrcLoc, SrcLoc )
60 import PrelMods ( pREL_GHC )
61 import PrelInfo ( cCallishTyKeys )
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
106 hi_boot_file = case from of {
107 ImportByUser -> False ; -- Not hi-boot
108 ImportByUserSource -> True ; -- hi-boot
111 Just (_, _, is_boot, _) -> is_boot
114 -- We're importing a module we know absolutely
115 -- nothing about, so we assume it's from
116 -- another package, where we aren't doing
117 -- dependency tracking. So it won't be a hi-boot file.
119 redundant_source_import
120 = case (from, mod_info) of
121 (ImportByUserSource, Just (_,_,False,_)) -> True
124 -- CHECK WHETHER WE HAVE IT ALREADY
126 Just (_, _, _, Just (load_mod, _, _))
127 -> -- We're read it already so don't re-read it
128 returnRn (load_mod, ifaces) ;
132 -- Issue a warning for a redundant {- SOURCE -} import
133 -- NB that we arrange to read all the ordinary imports before
134 -- any of the {- SOURCE -} imports
135 warnCheckRn (not redundant_source_import)
136 (warnRedundantSourceImport mod_name) `thenRn_`
138 -- READ THE MODULE IN
139 findAndReadIface doc_str mod_name hi_boot_file `thenRn` \ read_result ->
140 case read_result of {
141 Nothing -> -- Not found, so add an empty export env to the Ifaces map
142 -- so that we don't look again
144 mod = mkVanillaModule mod_name
145 new_mod_map = addToFM mod_map mod_name (0, False, False, Just (mod, from, []))
146 new_ifaces = ifaces { iImpModInfo = new_mod_map }
148 setIfacesRn new_ifaces `thenRn_`
149 failWithRn (mod, new_ifaces) (noIfaceErr mod hi_boot_file) ;
154 -- LOAD IT INTO Ifaces
156 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
157 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
158 -- If we do loadExport first the wrong info gets into the cache (unless we
159 -- explicitly tag each export which seems a bit of a bore)
161 getModuleRn `thenRn` \ this_mod_nm ->
163 rd_decls = pi_decls iface
166 -- Sanity check. If we're system-importing a module we know nothing at all
167 -- about, it should be from a different package to this one
168 WARN( not (maybeToBool mod_info) &&
169 case from of { ImportBySystem -> True; other -> False } &&
172 foldlRn (loadDecl mod) (iDecls ifaces) rd_decls `thenRn` \ new_decls ->
173 foldlRn (loadInstDecl mod) (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
174 (if opt_IgnoreIfacePragmas
175 then returnRn emptyBag
176 else foldlRn (loadRule mod) (iRules ifaces) (pi_rules iface)) `thenRn` \ new_rules ->
177 (if opt_IgnoreIfacePragmas
178 then returnRn emptyNameEnv
179 else foldlRn (loadDeprec mod) (iDeprecs ifaces) (pi_deprecs iface)) `thenRn` \ new_deprecs ->
180 foldlRn (loadFixDecl mod_name) (iFixes ifaces) rd_decls `thenRn` \ new_fixities ->
181 mapRn (loadExport this_mod_nm) (pi_exports iface) `thenRn` \ avails_s ->
183 -- For an explicit user import, add to mod_map info about
184 -- the things the imported module depends on, extracted
185 -- from its usage info.
186 mod_map1 = case from of
187 ImportByUser -> addModDeps mod (pi_usages iface) mod_map
190 -- Now add info about this module
191 mod_map2 = addToFM mod_map1 mod_name mod_details
192 cts = (pi_mod iface, from, concat avails_s)
193 mod_details = (pi_vers iface, pi_orphan iface, hi_boot_file, Just cts)
195 new_ifaces = ifaces { iImpModInfo = mod_map2,
197 iFixes = new_fixities,
200 iDeprecs = new_deprecs }
202 setIfacesRn new_ifaces `thenRn_`
203 returnRn (mod, new_ifaces)
206 addModDeps :: Module -> [ImportVersion a]
207 -> ImportedModuleInfo -> ImportedModuleInfo
208 -- (addModDeps M ivs deps)
209 -- We are importing module M, and M.hi contains 'import' decls given by ivs
210 addModDeps mod new_deps mod_deps
211 = foldr add mod_deps filtered_new_deps
213 -- Don't record dependencies when importing a module from another package
214 -- Except for its descendents which contain orphans,
215 -- and in that case, forget about the boot indicator
217 | isLocalModule mod = [ (imp_mod, (version, has_orphans, is_boot, Nothing))
218 | (imp_mod, version, has_orphans, is_boot, _) <- new_deps
220 | otherwise = [ (imp_mod, (version, True, False, Nothing))
221 | (imp_mod, version, has_orphans, _, _) <- new_deps,
224 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
226 combine old@(_, _, old_is_boot, cts) new
227 | maybeToBool cts || not old_is_boot = old -- Keep the old info if it's already loaded
228 -- or if it's a non-boot pending load
229 | otherwise = new -- Otherwise pick new info
231 loadExport :: ModuleName -> ExportItem -> RnM d [AvailInfo]
232 loadExport this_mod (mod, entities)
233 | mod == this_mod = returnRn []
234 -- If the module exports anything defined in this module, just ignore it.
235 -- Reason: otherwise it looks as if there are two local definition sites
236 -- for the thing, and an error gets reported. Easiest thing is just to
237 -- filter them out up front. This situation only arises if a module
238 -- imports itself, or another module that imported it. (Necessarily,
239 -- this invoves a loop.) Consequence: if you say
244 -- module B( AType ) where
245 -- import {-# SOURCE #-} A( AType )
247 -- then you'll get a 'B does not export AType' message. A bit bogus
248 -- but it's a bogus thing to do!
251 = mapRn (load_entity mod) entities
253 new_name mod occ = mkImportedGlobalName mod occ
255 load_entity mod (Avail occ)
256 = new_name mod occ `thenRn` \ name ->
257 returnRn (Avail name)
258 load_entity mod (AvailTC occ occs)
259 = new_name mod occ `thenRn` \ name ->
260 mapRn (new_name mod) occs `thenRn` \ names ->
261 returnRn (AvailTC name names)
264 loadFixDecl :: ModuleName -> FixityEnv
265 -> (Version, RdrNameHsDecl)
267 loadFixDecl mod_name fixity_env (version, FixD sig@(FixitySig rdr_name fixity loc))
268 = -- Ignore the version; when the fixity changes the version of
269 -- its 'host' entity changes, so we don't need a separate version
270 -- number for fixities
271 mkImportedGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
273 new_fixity_env = addToNameEnv fixity_env name (FixitySig name fixity loc)
275 returnRn new_fixity_env
277 -- Ignore the other sorts of decl
278 loadFixDecl mod_name fixity_env other_decl = returnRn fixity_env
282 -> (Version, RdrNameHsDecl)
285 loadDecl mod decls_map (version, decl)
286 = getDeclBinders new_name decl `thenRn` \ maybe_avail ->
287 case maybe_avail of {
288 Nothing -> returnRn decls_map; -- No bindings
291 getDeclSysBinders new_name decl `thenRn` \ sys_bndrs ->
293 full_avail = addSysAvails avail sys_bndrs
294 -- Add the sys-binders to avail. When we import the decl,
295 -- it's full_avail that will get added to the 'already-slurped' set (iSlurp)
296 -- If we miss out sys-binders, we'll read the decl multiple times!
298 main_name = availName avail
299 new_decls_map = foldl add_decl decls_map
300 [ (name, (version, full_avail, name==main_name, (mod, decl')))
301 | name <- availNames full_avail]
302 add_decl decls_map (name, stuff)
303 = WARN( name `elemNameEnv` decls_map, ppr name )
304 addToNameEnv decls_map name stuff
306 returnRn new_decls_map
309 -- newImportedBinder puts into the cache the binder with the
310 -- module information set correctly. When the decl is later renamed,
311 -- the binding site will thereby get the correct module.
312 new_name rdr_name loc = newImportedBinder mod rdr_name
315 If a signature decl is being loaded, and optIgnoreIfacePragmas is on,
316 we toss away unfolding information.
318 Also, if the signature is loaded from a module we're importing from source,
319 we do the same. This is to avoid situations when compiling a pair of mutually
320 recursive modules, peering at unfolding info in the interface file of the other,
321 e.g., you compile A, it looks at B's interface file and may as a result change
322 its interface file. Hence, B is recompiled, maybe changing its interface file,
323 which will the unfolding info used in A to become invalid. Simple way out is to
324 just ignore unfolding info.
326 [Jan 99: I junked the second test above. If we're importing from an hi-boot
327 file there isn't going to *be* any pragma info. Maybe the above comment
328 dates from a time where we picked up a .hi file first if it existed?]
331 SigD (IfaceSig name tp ls loc) | opt_IgnoreIfacePragmas
332 -> SigD (IfaceSig name tp [] loc)
335 loadInstDecl :: Module
338 -> RnM d (Bag GatedDecl)
339 loadInstDecl mod insts decl@(InstDecl inst_ty binds uprags dfun_name src_loc)
341 -- Find out what type constructors and classes are "gates" for the
342 -- instance declaration. If all these "gates" are slurped in then
343 -- we should slurp the instance decl too.
345 -- We *don't* want to count names in the context part as gates, though.
347 -- instance Foo a => Baz (T a) where ...
349 -- Here the gates are Baz and T, but *not* Foo.
351 munged_inst_ty = removeContext inst_ty
352 free_names = extractHsTyRdrNames munged_inst_ty
354 setModuleRn (moduleName mod) $
355 mapRn mkImportedGlobalFromRdrName free_names `thenRn` \ gate_names ->
356 returnRn ((mkNameSet gate_names, (mod, InstD decl)) `consBag` insts)
359 -- In interface files, the instance decls now look like
360 -- forall a. Foo a -> Baz (T a)
361 -- so we have to strip off function argument types as well
362 -- as the bit before the '=>' (which is always empty in interface files)
363 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
364 removeContext ty = removeFuns ty
366 removeFuns (MonoFunTy _ ty) = removeFuns ty
370 loadRule :: Module -> Bag GatedDecl
371 -> RdrNameRuleDecl -> RnM d (Bag GatedDecl)
372 -- "Gate" the rule simply by whether the rule variable is
373 -- needed. We can refine this later.
374 loadRule mod rules decl@(IfaceRuleDecl var body src_loc)
375 = setModuleRn (moduleName mod) $
376 mkImportedGlobalFromRdrName var `thenRn` \ var_name ->
377 returnRn ((unitNameSet var_name, (mod, RuleD decl)) `consBag` rules)
379 -- SUP: TEMPORARY HACK, ignoring module deprecations for now
380 loadDeprec :: Module -> DeprecationEnv -> RdrNameDeprecation -> RnM d DeprecationEnv
381 loadDeprec mod deprec_env (Deprecation (IEModuleContents _) txt)
382 = traceRn (text "module deprecation not yet implemented:" <+> ppr mod <> colon <+> ppr txt) `thenRn_`
384 loadDeprec mod deprec_env (Deprecation ie txt)
385 = setModuleRn (moduleName mod) $
386 mapRn mkImportedGlobalFromRdrName (namesFromIE ie) `thenRn` \ names ->
387 traceRn (text "loaded deprecation(s) for" <+> hcat (punctuate comma (map ppr names)) <> colon <+> ppr txt) `thenRn_`
388 returnRn (extendNameEnv deprec_env (zip names (repeat txt)))
390 namesFromIE :: IE a -> [a]
391 namesFromIE (IEVar n ) = [n]
392 namesFromIE (IEThingAbs n ) = [n]
393 namesFromIE (IEThingAll n ) = [n]
394 namesFromIE (IEThingWith n ns) = n:ns
395 namesFromIE (IEModuleContents _ ) = []
399 %********************************************************
401 \subsection{Loading usage information}
403 %********************************************************
409 checkUpToDate :: ModuleName -> RnMG Bool -- True <=> no need to recompile
410 -- When this guy is called, we already know that the
411 -- source code is unchanged from last time
412 checkUpToDate mod_name
413 = getIfacesRn `thenRn` \ ifaces ->
414 findAndReadIface doc_str mod_name
415 False {- Not hi-boot -} `thenRn` \ read_result ->
417 -- CHECK WHETHER WE HAVE IT ALREADY
419 Nothing -> -- Old interface file not found, so we'd better bail out
420 traceRn (sep [ptext SLIT("Didnt find old iface"),
421 pprModuleName mod_name]) `thenRn_`
425 -> -- Found it, so now check it
426 checkModUsage (pi_usages iface)
428 -- Only look in current directory, with suffix .hi
429 doc_str = sep [ptext SLIT("need usage info from"), pprModuleName mod_name]
431 checkModUsage [] = returnRn upToDate -- Yes! Everything is up to date!
433 checkModUsage ((mod_name, old_mod_vers, _, _, Specifically []) : rest)
434 -- If CurrentModule.hi contains
436 -- then that simply records that Foo lies below CurrentModule in the
437 -- hierarchy, but CurrentModule doesn't depend in any way on Foo.
438 -- In this case we don't even want to open Foo's interface.
439 = traceRn (ptext SLIT("Nothing used from:") <+> ppr mod_name) `thenRn_`
440 checkModUsage rest -- This one's ok, so check the rest
442 checkModUsage ((mod_name, old_mod_vers, _, _, whats_imported) : rest)
443 = loadInterface doc_str mod_name ImportBySystem `thenRn` \ (mod, ifaces) ->
445 maybe_mod_vers = case lookupFM (iImpModInfo ifaces) mod_name of
446 Just (version, _, _, Just (_, _, _)) -> Just version
449 case maybe_mod_vers of {
450 Nothing -> -- If we can't find a version number for the old module then
451 -- bail out saying things aren't up to date
452 traceRn (sep [ptext SLIT("Can't find version number for module"),
453 pprModuleName mod_name])
454 `thenRn_` returnRn outOfDate ;
458 -- If the module version hasn't changed, just move on
459 if new_mod_vers == old_mod_vers then
460 traceRn (sep [ptext SLIT("Module version unchanged:"), pprModuleName mod_name])
461 `thenRn_` checkModUsage rest
463 traceRn (sep [ptext SLIT("Module version has changed:"), pprModuleName mod_name])
465 -- Module version changed, so check entities inside
467 -- If the usage info wants to say "I imported everything from this module"
468 -- it does so by making whats_imported equal to Everything
469 -- In that case, we must recompile
470 case whats_imported of {
471 Everything -> traceRn (ptext SLIT("...and I needed the whole module")) `thenRn_`
472 returnRn outOfDate; -- Bale out
474 Specifically old_local_vers ->
476 -- Non-empty usage list, so check item by item
477 checkEntityUsage mod_name (iDecls ifaces) old_local_vers `thenRn` \ up_to_date ->
479 traceRn (ptext SLIT("...but the bits I use haven't.")) `thenRn_`
480 checkModUsage rest -- This one's ok, so check the rest
482 returnRn outOfDate -- This one failed, so just bail out now
485 doc_str = sep [ptext SLIT("need version info for"), pprModuleName mod_name]
488 checkEntityUsage mod decls []
489 = returnRn upToDate -- Yes! All up to date!
491 checkEntityUsage mod decls ((occ_name,old_vers) : rest)
492 = mkImportedGlobalName mod occ_name `thenRn` \ name ->
493 case lookupNameEnv decls name of
495 Nothing -> -- We used it before, but it ain't there now
496 traceRn (sep [ptext SLIT("No longer exported:"), ppr name])
497 `thenRn_` returnRn outOfDate
499 Just (new_vers,_,_,_) -- It's there, but is it up to date?
500 | new_vers == old_vers
501 -- Up to date, so check the rest
502 -> checkEntityUsage mod decls rest
505 -- Out of date, so bale out
506 -> traceRn (sep [ptext SLIT("Out of date:"), ppr name]) `thenRn_`
511 %*********************************************************
513 \subsection{Getting in a declaration}
515 %*********************************************************
518 importDecl :: Name -> RnMG (Maybe (Module, RdrNameHsDecl))
519 -- Returns Nothing for
522 -- (c) already slurped
528 = getSlurped `thenRn` \ already_slurped ->
529 if name `elemNameSet` already_slurped then
530 returnRn Nothing -- Already dealt with
532 if isLocallyDefined name then -- Don't bring in decls from
533 -- the renamed module's own interface file
534 addWarnRn (importDeclWarn name) `thenRn_`
537 getNonWiredInDecl name
541 getNonWiredInDecl :: Name -> RnMG (Maybe (Module, RdrNameHsDecl))
542 getNonWiredInDecl needed_name
543 = traceRn doc_str `thenRn_`
544 loadHomeInterface doc_str needed_name `thenRn` \ ifaces ->
545 case lookupNameEnv (iDecls ifaces) needed_name of
547 Just (version,avail,_,decl)
548 -> recordSlurp (Just version) avail `thenRn_`
551 Nothing -- Can happen legitimately for "Optional" occurrences
552 -> addErrRn (getDeclErr needed_name) `thenRn_`
555 doc_str = ptext SLIT("need decl for") <+> ppr needed_name
558 @getWiredInDecl@ maps a wired-in @Name@ to what it makes available.
559 It behaves exactly as if the wired in decl were actually in an interface file.
562 \item if the wired-in name is a data type constructor or a data constructor,
563 it brings in the type constructor and all the data constructors; and
564 marks as ``occurrences'' any free vars of the data con.
566 \item similarly for synonum type constructor
568 \item if the wired-in name is another wired-in Id, it marks as ``occurrences''
569 the free vars of the Id's type.
571 \item it loads the interface file for the wired-in thing for the
572 sole purpose of making sure that its instance declarations are available
574 All this is necessary so that we know all types that are ``in play'', so
575 that we know just what instances to bring into scope.
580 %*********************************************************
582 \subsection{Getting what a module exports}
584 %*********************************************************
586 @getInterfaceExports@ is called only for directly-imported modules.
589 getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, Avails)
590 getInterfaceExports mod_name from
591 = loadInterface doc_str mod_name from `thenRn` \ (mod, ifaces) ->
592 case lookupFM (iImpModInfo ifaces) mod_name of
593 Nothing -> -- Not there; it must be that the interface file wasn't found;
594 -- the error will have been reported already.
595 -- (Actually loadInterface should put the empty export env in there
596 -- anyway, but this does no harm.)
599 Just (_, _, _, Just (mod, _, avails)) -> returnRn (mod, avails)
601 doc_str = sep [pprModuleName mod_name, ptext SLIT("is directly imported")]
605 %*********************************************************
607 \subsection{Instance declarations are handled specially}
609 %*********************************************************
612 getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)]
613 getImportedInstDecls gates
614 = -- First, load any orphan-instance modules that aren't aready loaded
615 -- Orphan-instance modules are recorded in the module dependecnies
616 getIfacesRn `thenRn` \ ifaces ->
619 [mod | (mod, (_, True, _, Nothing)) <- fmToList (iImpModInfo ifaces)]
621 loadOrphanModules orphan_mods `thenRn_`
623 -- Now we're ready to grab the instance declarations
624 -- Find the un-gated ones and return them,
625 -- removing them from the bag kept in Ifaces
626 getIfacesRn `thenRn` \ ifaces ->
628 (decls, new_insts) = selectGated gates (iInsts ifaces)
630 setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_`
632 traceRn (sep [text "getImportedInstDecls:",
633 nest 4 (fsep (map ppr gate_list)),
634 text "Slurped" <+> int (length decls) <+> text "instance declarations",
635 nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_`
638 gate_list = nameSetToList gates
640 ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _))
642 HsForAllTy _ _ tau -> ppr tau
645 getImportedRules :: RnMG [(Module,RdrNameHsDecl)]
647 | opt_IgnoreIfacePragmas = returnRn []
649 = getIfacesRn `thenRn` \ ifaces ->
651 gates = iSlurp ifaces -- Anything at all that's been slurped
652 (decls, new_rules) = selectGated gates (iRules ifaces)
654 setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
655 traceRn (sep [text "getImportedRules:",
656 text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
659 selectGated gates decl_bag
660 -- Select only those decls whose gates are *all* in 'gates'
662 | opt_NoPruneDecls -- Just to try the effect of not gating at all
663 = (foldrBag (\ (_,d) ds -> d:ds) [] decl_bag, emptyBag) -- Grab them all
667 = foldrBag select ([], emptyBag) decl_bag
669 select (reqd, decl) (yes, no)
670 | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no)
671 | otherwise = (yes, (reqd,decl) `consBag` no)
673 lookupFixity :: Name -> RnMS Fixity
675 | isLocallyDefined name
676 = getFixityEnv `thenRn` \ local_fix_env ->
677 case lookupNameEnv local_fix_env name of
678 Just (FixitySig _ fix _) -> returnRn fix
679 Nothing -> returnRn defaultFixity
681 | otherwise -- Imported
682 -- For imported names, we have to get their fixities by doing a loadHomeInterface,
683 -- and consulting the Ifaces that comes back from that, because the interface
684 -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
685 -- which exports a function 'f', which is defined in module B. Then B isn't loaded
686 -- right away (after all, it's possible that nothing from B will be used).
687 -- When we come across a use of 'f', we need to know its fixity, and it's then,
688 -- and only then, that we load B.hi. That is what's happening here.
689 = loadHomeInterface doc name `thenRn` \ ifaces ->
690 case lookupNameEnv (iFixes ifaces) name of
691 Just (FixitySig _ fix _) -> returnRn fix
692 Nothing -> returnRn defaultFixity
694 doc = ptext SLIT("Checking fixity for") <+> ppr name
698 %*********************************************************
700 \subsection{Keeping track of what we've slurped, and version numbers}
702 %*********************************************************
704 getImportVersions figures out what the ``usage information'' for this
705 moudule is; that is, what it must record in its interface file as the
706 things it uses. It records:
709 \item (a) anything reachable from its body code
710 \item (b) any module exported with a @module Foo@
711 \item (c) anything reachable from an exported item
714 Why (b)? Because if @Foo@ changes then this module's export list
715 will change, so we must recompile this module at least as far as
716 making a new interface file --- but in practice that means complete
719 Why (c)? Consider this:
721 module A( f, g ) where | module B( f ) where
722 import B( f ) | f = h 3
726 Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
727 @A@'s usages? Our idea is that we aren't going to touch A.hi if it is
728 *identical* to what it was before. If anything about @B.f@ changes
729 than anyone who imports @A@ should be recompiled in case they use
730 @B.f@ (they'll get an early exit if they don't). So, if anything
731 about @B.f@ changes we'd better make sure that something in A.hi
732 changes, and the convenient way to do that is to record the version
733 number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
734 complete recompiation of A, which is overkill but it's the only way to
735 write a new, slightly different, A.hi.
737 But the example is tricker. Even if @B.f@ doesn't change at all,
738 @B.h@ may do so, and this change may not be reflected in @f@'s version
739 number. But with -O, a module that imports A must be recompiled if
740 @B.h@ changes! So A must record a dependency on @B.h@. So we treat
741 the occurrence of @B.f@ in the export list *just as if* it were in the
742 code of A, and thereby haul in all the stuff reachable from it.
744 [NB: If B was compiled with -O, but A isn't, we should really *still*
745 haul in all the unfoldings for B, in case the module that imports A *is*
746 compiled with -O. I think this is the case.]
748 Even if B is used at all we get a usage line for B
749 import B <n> :: ... ;
750 in A.hi, to record the fact that A does import B. This is used to decide
751 to look to look for B.hi rather than B.hi-boot when compiling a module that
752 imports A. This line says that A imports B, but uses nothing in it.
753 So we'll get an early bale-out when compiling A if B's version changes.
756 getImportVersions :: ModuleName -- Name of this module
757 -> ExportEnv -- Info about exports
758 -> RnMG (VersionInfo Name) -- Version info for these names
760 getImportVersions this_mod (ExportEnv _ _ export_all_mods)
761 = getIfacesRn `thenRn` \ ifaces ->
763 mod_map = iImpModInfo ifaces
764 imp_names = iVSlurp ifaces
766 -- mv_map groups together all the things imported from a particular module.
767 mv_map :: FiniteMap ModuleName [(Name,Version)]
768 mv_map = foldr add_mv emptyFM imp_names
770 -- Build the result list by adding info for each module.
771 -- For (a) a library module, we don't record it at all unless it contains orphans
772 -- (We must never lose track of orphans.)
774 -- (b) a source-imported module, don't record the dependency at all
776 -- (b) may seem a bit strange. The idea is that the usages in a .hi file records
777 -- *all* the module's dependencies other than the loop-breakers. We use
778 -- this info in findAndReadInterface to decide whether to look for a .hi file or
781 -- This means we won't track version changes, or orphans, from .hi-boot files.
782 -- The former is potentially rather bad news. It could be fixed by recording
783 -- whether something is a boot file along with the usage info for it, but
784 -- I can't be bothered just now.
786 mk_version_info mod_name (version, has_orphans, is_boot, contents) so_far
787 | mod_name == this_mod -- Check if M appears in the set of modules 'below' M
788 -- This seems like a convenient place to check
789 = WARN( not is_boot, ptext SLIT("Wierd:") <+> ppr this_mod <+>
790 ptext SLIT("imports itself (perhaps indirectly)") )
795 go_for_it exports = (mod_name, version, has_orphans, is_boot, exports)
799 Nothing -> -- We didn't even open the interface
800 -- This happens when a module, Foo, that we explicitly imported has
801 -- 'import Baz' in its interface file, recording that Baz is below
802 -- Foo in the module dependency hierarchy. We want to propagate this
803 -- information. The Nothing says that we didn't even open the interface
804 -- file but we must still propagate the dependeny info.
805 -- The module in question must be a local module (in the same package)
806 go_for_it (Specifically [])
808 Just (mod, how_imported, _)
809 | is_sys_import && is_lib_module && not has_orphans
812 | is_lib_module -- Record the module but not detailed
813 || mod_name `elem` export_all_mods -- version information for the imports
814 -> go_for_it Everything
817 -> case lookupFM mv_map mod_name of
818 Just whats_imported -> go_for_it (Specifically whats_imported)
819 Nothing -> go_for_it (Specifically [])
820 -- This happens if you have
822 -- but don't actually *use* anything from Foo
823 -- In which case record an empty dependency list
825 is_lib_module = not (isLocalModule mod)
826 is_sys_import = case how_imported of
827 ImportBySystem -> True
832 returnRn (foldFM mk_version_info [] mod_map)
834 add_mv v@(name, version) mv_map
835 = addToFM_C add_item mv_map mod [v]
837 mod = moduleName (nameModule name)
838 add_item vs _ = (v:vs)
843 = getIfacesRn `thenRn` \ ifaces ->
844 returnRn (iSlurp ifaces)
846 recordSlurp maybe_version avail
847 -- Nothing for locally defined names
848 -- Just version for imported names
849 = getIfacesRn `thenRn` \ ifaces@(Ifaces { iSlurp = slurped_names,
850 iVSlurp = imp_names }) ->
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 setIfacesRn (ifaces { iSlurp = new_slurped_names,
859 iVSlurp = new_imp_names })
863 %*********************************************************
865 \subsection{Getting binders out of a declaration}
867 %*********************************************************
869 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
870 It's used for both source code (from @availsFromDecl@) and interface files
873 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
874 are handled by the sourc-code specific stuff in @RnNames@.
877 getDeclBinders :: (RdrName -> SrcLoc -> RnM d Name) -- New-name function
879 -> RnM d (Maybe AvailInfo)
881 getDeclBinders new_name (TyClD (TyData _ _ tycon _ condecls _ _ src_loc))
882 = new_name tycon src_loc `thenRn` \ tycon_name ->
883 getConFieldNames new_name condecls `thenRn` \ sub_names ->
884 returnRn (Just (AvailTC tycon_name (tycon_name : nub sub_names)))
885 -- The "nub" is because getConFieldNames can legitimately return duplicates,
886 -- when a record declaration has the same field in multiple constructors
888 getDeclBinders new_name (TyClD (TySynonym tycon _ _ src_loc))
889 = new_name tycon src_loc `thenRn` \ tycon_name ->
890 returnRn (Just (AvailTC tycon_name [tycon_name]))
892 getDeclBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ _ _ _ _ src_loc))
893 = new_name cname src_loc `thenRn` \ class_name ->
895 -- Record the names for the class ops
897 -- just want class-op sigs
898 op_sigs = filter isClassOpSig sigs
900 mapRn (getClassOpNames new_name) op_sigs `thenRn` \ sub_names ->
902 returnRn (Just (AvailTC class_name (class_name : sub_names)))
904 getDeclBinders new_name (SigD (IfaceSig var ty prags src_loc))
905 = new_name var src_loc `thenRn` \ var_name ->
906 returnRn (Just (Avail var_name))
908 getDeclBinders new_name (FixD _) = returnRn Nothing
910 -- foreign declarations
911 getDeclBinders new_name (ForD (ForeignDecl nm kind _ dyn _ loc))
912 | binds_haskell_name kind dyn
913 = new_name nm loc `thenRn` \ name ->
914 returnRn (Just (Avail name))
916 | otherwise -- a foreign export
917 = lookupImplicitOccRn nm `thenRn_`
920 getDeclBinders new_name (DefD _) = returnRn Nothing
921 getDeclBinders new_name (InstD _) = returnRn Nothing
922 getDeclBinders new_name (RuleD _) = returnRn Nothing
924 binds_haskell_name (FoImport _) _ = True
925 binds_haskell_name FoLabel _ = True
926 binds_haskell_name FoExport ext_nm = isDynamicExtName ext_nm
929 getConFieldNames new_name (ConDecl con _ _ _ (RecCon fielddecls) src_loc : rest)
930 = mapRn (\n -> new_name n src_loc) (con:fields) `thenRn` \ cfs ->
931 getConFieldNames new_name rest `thenRn` \ ns ->
934 fields = concat (map fst fielddecls)
936 getConFieldNames new_name (ConDecl con _ _ _ condecl src_loc : rest)
937 = new_name con src_loc `thenRn` \ n ->
940 new_name f src_loc `thenRn` \ new_f ->
942 _ -> returnRn [n]) `thenRn` \ nn ->
943 getConFieldNames new_name rest `thenRn` \ ns ->
946 getConFieldNames new_name [] = returnRn []
948 getClassOpNames new_name (ClassOpSig op _ _ _ src_loc) = new_name op src_loc
951 @getDeclSysBinders@ gets the implicit binders introduced by a decl.
952 A the moment that's just the tycon and datacon that come with a class decl.
953 They aren't returned by @getDeclBinders@ because they aren't in scope;
954 but they {\em should} be put into the @DeclsMap@ of this module.
956 Note that this excludes the default-method names of a class decl,
957 and the dict fun of an instance decl, because both of these have
958 bindings of their own elsewhere.
961 getDeclSysBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ tname dname dwname snames src_loc))
962 = sequenceRn [new_name n src_loc | n <- (tname : dname : dwname : snames)]
964 getDeclSysBinders new_name (TyClD (TyData _ _ _ _ cons _ _ _))
965 = sequenceRn [new_name wkr_name src_loc | ConDecl _ wkr_name _ _ _ src_loc <- cons]
967 getDeclSysBinders new_name other_decl
971 %*********************************************************
973 \subsection{Reading an interface file}
975 %*********************************************************
978 findAndReadIface :: SDoc -> ModuleName
979 -> IsBootInterface -- True <=> Look for a .hi-boot file
980 -- False <=> Look for .hi file
981 -> RnM d (Maybe ParsedIface)
982 -- Nothing <=> file not found, or unreadable, or illegible
983 -- Just x <=> successfully found and parsed
985 findAndReadIface doc_str mod_name hi_boot_file
986 = traceRn trace_msg `thenRn_`
987 -- we keep two maps for interface files,
988 -- one for 'normal' ones, the other for .hi-boot files,
989 -- hence the need to signal which kind we're interested.
991 getHiMaps `thenRn` \ (hi_map, hiboot_map) ->
993 relevant_map | hi_boot_file = hiboot_map
996 case lookupFM relevant_map mod_name of
998 Just fpath -> traceRn (ptext SLIT("...reading from") <+> text fpath) `thenRn_`
999 readIface mod_name fpath
1002 Nothing -> traceRn (ptext SLIT("...not found")) `thenRn_`
1005 trace_msg = sep [hsep [ptext SLIT("Reading"),
1006 if hi_boot_file then ptext SLIT("[boot]") else empty,
1007 ptext SLIT("interface for"),
1008 pprModuleName mod_name <> semi],
1009 nest 4 (ptext SLIT("reason:") <+> doc_str)]
1012 @readIface@ tries just the one file.
1015 readIface :: ModuleName -> String -> RnM d (Maybe ParsedIface)
1016 -- Nothing <=> file not found, or unreadable, or illegible
1017 -- Just x <=> successfully found and parsed
1018 readIface wanted_mod file_path
1019 = ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
1022 case parseIface contents
1023 PState{ bol = 0#, atbol = 1#,
1026 loc = mkSrcLoc (mkFastString file_path) 1 } of
1027 POk _ (PIface iface) ->
1028 warnCheckRn (read_mod == wanted_mod)
1029 (hiModuleNameMismatchWarn wanted_mod read_mod) `thenRn_`
1030 returnRn (Just iface)
1032 read_mod = moduleName (pi_mod iface)
1034 PFailed err -> failWithRn Nothing err
1035 other -> failWithRn Nothing (ptext SLIT("Unrecognisable interface file"))
1036 -- This last case can happen if the interface file is (say) empty
1037 -- in which case the parser thinks it looks like an IdInfo or
1038 -- something like that. Just an artefact of the fact that the
1039 -- parser is used for several purposes at once.
1042 | isDoesNotExistError err -> returnRn Nothing
1043 | otherwise -> failWithRn Nothing (cannaeReadFile file_path err)
1046 %*********************************************************
1050 %*********************************************************
1053 noIfaceErr filename boot_file
1054 = hsep [ptext SLIT("Could not find valid"), boot,
1055 ptext SLIT("interface file"), quotes (pprModule filename)]
1057 boot | boot_file = ptext SLIT("[boot]")
1060 cannaeReadFile file err
1061 = hcat [ptext SLIT("Failed in reading file: "),
1063 ptext SLIT("; error="),
1067 = vcat [ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name),
1068 ptext SLIT("from module") <+> quotes (ppr (nameModule name))
1071 getDeclWarn name loc
1072 = sep [ptext SLIT("Failed to find (optional) interface decl for") <+> quotes (ppr name),
1073 ptext SLIT("desired at") <+> ppr loc]
1077 "Compiler tried to import decl from interface file with same name as module."),
1079 "(possible cause: module name clashes with interface file already in scope.)")
1081 hsep [ptext SLIT("name:"), quotes (ppr name)]
1083 warnRedundantSourceImport mod_name
1084 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
1085 <+> quotes (pprModuleName mod_name)
1087 hiModuleNameMismatchWarn :: ModuleName -> ModuleName -> Message
1088 hiModuleNameMismatchWarn requested_mod read_mod =
1089 hsep [ ptext SLIT("Something is amiss; requested module name")
1090 , pprModuleName requested_mod
1091 , ptext SLIT("differs from name found in the interface file")
1092 , pprModuleName read_mod