2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[RnIfaces]{Cacheing and Renaming of Interfaces}
12 getImportedInstDecls, getImportedRules,
13 lookupFixityRn, loadHomeInterface,
14 importDecl, ImportDeclResult(..), recordLocalSlurps,
15 mkImportInfo, getSlurped,
17 getDeclBinders, getDeclSysBinders,
18 removeContext -- removeContext probably belongs somewhere else
22 #include "HsVersions.h"
24 import CmdLineOpts ( opt_NoPruneDecls, opt_NoPruneTyDecls, opt_IgnoreIfacePragmas )
26 import HsSyn ( HsDecl(..), TyClDecl(..), InstDecl(..), IfaceSig(..),
27 HsType(..), ConDecl(..),
28 ForeignDecl(..), ForKind(..), isDynamicExtName,
29 FixitySig(..), RuleDecl(..),
32 import HsImpExp ( ImportDecl(..) )
33 import BasicTypes ( Version, defaultFixity )
34 import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameRuleDecl,
39 import ParseIface ( parseIface, IfaceStuff(..) )
41 import Name ( Name {-instance NamedThing-}, nameOccName,
42 nameModule, isLocallyDefined,
44 mkNameEnv, elemNameEnv, extendNameEnv
46 import Module ( Module, ModuleEnv,
47 moduleName, isModuleInThisPackage,
48 ModuleName, WhereFrom(..),
49 emptyModuleEnv, extendModuleEnv, lookupModuleEnvByName,
50 extendModuleEnv_C, lookupWithDefaultModuleEnv
52 import RdrName ( RdrName, rdrNameOcc )
54 import SrcLoc ( mkSrcLoc, SrcLoc )
55 import PrelInfo ( wiredInThingEnv )
56 import Maybes ( maybeToBool, orElse )
57 import StringBuffer ( hGetStringBuffer )
58 import FastString ( mkFastString )
59 import ErrUtils ( Message )
69 %*********************************************************
71 \subsection{Loading a new interface file}
73 %*********************************************************
76 loadHomeInterface :: SDoc -> Name -> RnM d Ifaces
77 loadHomeInterface doc_str name
78 = loadInterface doc_str (moduleName (nameModule name)) ImportBySystem
80 loadOrphanModules :: [ModuleName] -> RnM d ()
81 loadOrphanModules mods
82 | null mods = returnRn ()
83 | otherwise = traceRn (text "Loading orphan modules:" <+>
84 fsep (map ppr mods)) `thenRn_`
85 mapRn_ load mods `thenRn_`
88 load mod = loadInterface (mk_doc mod) mod ImportBySystem
89 mk_doc mod = ppr mod <+> ptext SLIT("is a orphan-instance module")
92 loadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d Ifaces
93 loadInterface doc mod from
94 = tryLoadInterface doc mod from `thenRn` \ (ifaces, maybe_err) ->
96 Nothing -> returnRn ifaces
97 Just err -> failWithRn ifaces err
99 tryLoadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d (Ifaces, Maybe Message)
100 -- Returns (Just err) if an error happened
101 -- Guarantees to return with iImpModInfo m --> (..., True)
102 -- (If the load fails, we plug in a vanilla placeholder)
103 tryLoadInterface doc_str mod_name from
104 = getHomeIfaceTableRn `thenRn` \ hit ->
105 getIfacesRn `thenRn` \ ifaces ->
107 -- Check whether we have it already in the home package
108 case lookupModuleEnvByName hit mod_name of {
109 Just _ -> returnRn (ifaces, Nothing) ; -- In the home package
113 mod_map = iImpModInfo ifaces
114 mod_info = lookupFM mod_map mod_name
117 = case (from, mod_info) of
118 (ImportByUser, _) -> False -- Not hi-boot
119 (ImportByUserSource, _) -> True -- hi-boot
120 (ImportBySystem, Just (_, is_boot, _)) -> is_boot --
121 (ImportBySystem, Nothing) -> False
122 -- We're importing a module we know absolutely
123 -- nothing about, so we assume it's from
124 -- another package, where we aren't doing
125 -- dependency tracking. So it won't be a hi-boot file.
127 redundant_source_import
128 = case (from, mod_info) of
129 (ImportByUserSource, Just (_,False,_)) -> True
132 -- CHECK WHETHER WE HAVE IT ALREADY
135 -> -- We're read it already so don't re-read it
136 returnRn (ifaces, Nothing) ;
140 -- Issue a warning for a redundant {- SOURCE -} import
141 -- NB that we arrange to read all the ordinary imports before
142 -- any of the {- SOURCE -} imports
143 warnCheckRn (not redundant_source_import)
144 (warnRedundantSourceImport mod_name) `thenRn_`
146 -- READ THE MODULE IN
147 findAndReadIface doc_str mod_name hi_boot_file `thenRn` \ read_result ->
148 case read_result of {
149 Left err -> -- Not found, so add an empty export env to the Ifaces map
150 -- so that we don't look again
152 new_mod_map = addToFM mod_map mod_name (False, False, True)
153 new_ifaces = ifaces { iImpModInfo = new_mod_map }
155 setIfacesRn new_ifaces `thenRn_`
156 returnRn (new_ifaces, Just err) ;
159 Right (mod, iface) ->
161 -- LOAD IT INTO Ifaces
163 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
164 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
165 -- If we do loadExport first the wrong info gets into the cache (unless we
166 -- explicitly tag each export which seems a bit of a bore)
169 -- Sanity check. If we're system-importing a module we know nothing at all
170 -- about, it should be from a different package to this one
171 WARN( not (maybeToBool mod_info) &&
172 case from of { ImportBySystem -> True; other -> False } &&
173 isModuleInThisPackage mod,
176 loadDecls mod (iDecls ifaces) (pi_decls iface) `thenRn` \ (decls_vers, new_decls) ->
177 loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ (rule_vers, new_rules) ->
178 loadFixDecls mod_name (pi_fixity iface) `thenRn` \ fix_env ->
179 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
180 foldlRn (loadInstDecl mod) (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
181 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
183 version = VersionInfo { vers_module = pi_vers iface,
184 vers_exports = export_vers,
185 vers_rules = rule_vers,
186 vers_decls = decls_vers }
188 -- For an explicit user import, add to mod_map info about
189 -- the things the imported module depends on, extracted
190 -- from its usage info.
191 mod_map1 = case from of
192 ImportByUser -> addModDeps mod (pi_usages iface) mod_map
194 mod_map2 = addToFM mod_map1 mod_name (has_orphans, hi_boot_file, True)
196 -- Now add info about this module to the PIT
197 has_orphans = pi_orphan iface
198 new_pit = extendModuleEnv (iPIT ifaces) mod mod_iface
199 mod_iface = ModIface { mi_module = mod, mi_version = version,
200 mi_exports = avails, mi_orphan = has_orphans,
201 mi_fixities = fix_env, mi_deprecs = deprec_env,
202 mi_usages = [], -- Will be filled in later
203 mi_decls = panic "No mi_decls in PIT",
204 mi_globals = panic "No mi_globals in PIT"
207 new_ifaces = ifaces { iPIT = new_pit,
211 iImpModInfo = mod_map2 }
213 setIfacesRn new_ifaces `thenRn_`
214 returnRn (new_ifaces, Nothing)
217 -----------------------------------------------------
218 -- Adding module dependencies from the
219 -- import decls in the interface file
220 -----------------------------------------------------
222 addModDeps :: Module -> [ImportVersion a]
223 -> ImportedModuleInfo -> ImportedModuleInfo
224 -- (addModDeps M ivs deps)
225 -- We are importing module M, and M.hi contains 'import' decls given by ivs
226 addModDeps mod new_deps mod_deps
227 = foldr add mod_deps filtered_new_deps
229 -- Don't record dependencies when importing a module from another package
230 -- Except for its descendents which contain orphans,
231 -- and in that case, forget about the boot indicator
232 filtered_new_deps :: [(ModuleName, (WhetherHasOrphans, IsBootInterface, IsLoaded))]
234 | isModuleInThisPackage mod
235 = [ (imp_mod, (has_orphans, is_boot, False))
236 | (imp_mod, has_orphans, is_boot, _) <- new_deps
238 | otherwise = [ (imp_mod, (True, False, False))
239 | (imp_mod, has_orphans, _, _) <- new_deps,
242 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
244 combine old@(_, old_is_boot, old_is_loaded) new
245 | old_is_loaded || not old_is_boot = old -- Keep the old info if it's already loaded
246 -- or if it's a non-boot pending load
247 | otherwise = new -- Otherwise pick new info
250 -----------------------------------------------------
251 -- Loading the export list
252 -----------------------------------------------------
254 loadExports :: (Version, [ExportItem]) -> RnM d (Version, Avails)
255 loadExports (vers, items)
256 = getModuleRn `thenRn` \ this_mod ->
257 mapRn (loadExport this_mod) items `thenRn` \ avails_s ->
258 returnRn (vers, concat avails_s)
261 loadExport :: Module -> ExportItem -> RnM d [AvailInfo]
262 loadExport this_mod (mod, entities)
263 | mod == moduleName this_mod = returnRn []
264 -- If the module exports anything defined in this module, just ignore it.
265 -- Reason: otherwise it looks as if there are two local definition sites
266 -- for the thing, and an error gets reported. Easiest thing is just to
267 -- filter them out up front. This situation only arises if a module
268 -- imports itself, or another module that imported it. (Necessarily,
269 -- this invoves a loop.) Consequence: if you say
274 -- module B( AType ) where
275 -- import {-# SOURCE #-} A( AType )
277 -- then you'll get a 'B does not export AType' message. A bit bogus
278 -- but it's a bogus thing to do!
281 = mapRn (load_entity mod) entities
283 new_name mod occ = newGlobalName mod occ
285 load_entity mod (Avail occ)
286 = new_name mod occ `thenRn` \ name ->
287 returnRn (Avail name)
288 load_entity mod (AvailTC occ occs)
289 = new_name mod occ `thenRn` \ name ->
290 mapRn (new_name mod) occs `thenRn` \ names ->
291 returnRn (AvailTC name names)
294 -----------------------------------------------------
295 -- Loading type/class/value decls
296 -----------------------------------------------------
300 -> [(Version, RdrNameHsDecl)]
301 -> RnM d (NameEnv Version, DeclsMap)
302 loadDecls mod decls_map decls
303 = foldlRn (loadDecl mod) (emptyNameEnv, decls_map) decls
306 -> (NameEnv Version, DeclsMap)
307 -> (Version, RdrNameHsDecl)
308 -> RnM d (NameEnv Version, DeclsMap)
309 loadDecl mod (version_map, decls_map) (version, decl)
310 = getDeclBinders new_name decl `thenRn` \ maybe_avail ->
311 case maybe_avail of {
312 Nothing -> returnRn (version_map, decls_map); -- No bindings
315 getDeclSysBinders new_name decl `thenRn` \ sys_bndrs ->
317 full_avail = addSysAvails avail sys_bndrs
318 -- Add the sys-binders to avail. When we import the decl,
319 -- it's full_avail that will get added to the 'already-slurped' set (iSlurp)
320 -- If we miss out sys-binders, we'll read the decl multiple times!
322 main_name = availName avail
323 new_decls_map = foldl add_decl decls_map
324 [ (name, (full_avail, name==main_name, (mod, decl')))
325 | name <- availNames full_avail]
326 add_decl decls_map (name, stuff)
327 = WARN( name `elemNameEnv` decls_map, ppr name )
328 extendNameEnv decls_map name stuff
330 new_version_map = extendNameEnv version_map main_name version
332 returnRn (new_version_map, new_decls_map)
335 -- newTopBinder puts into the cache the binder with the
336 -- module information set correctly. When the decl is later renamed,
337 -- the binding site will thereby get the correct module.
338 -- There maybe occurrences that don't have the correct Module, but
339 -- by the typechecker will propagate the binding definition to all
340 -- the occurrences, so that doesn't matter
341 new_name rdr_name loc = newTopBinder mod rdr_name loc
344 If a signature decl is being loaded, and optIgnoreIfacePragmas is on,
345 we toss away unfolding information.
347 Also, if the signature is loaded from a module we're importing from source,
348 we do the same. This is to avoid situations when compiling a pair of mutually
349 recursive modules, peering at unfolding info in the interface file of the other,
350 e.g., you compile A, it looks at B's interface file and may as a result change
351 its interface file. Hence, B is recompiled, maybe changing its interface file,
352 which will the unfolding info used in A to become invalid. Simple way out is to
353 just ignore unfolding info.
355 [Jan 99: I junked the second test above. If we're importing from an hi-boot
356 file there isn't going to *be* any pragma info. Maybe the above comment
357 dates from a time where we picked up a .hi file first if it existed?]
360 SigD (IfaceSig name tp ls loc) | opt_IgnoreIfacePragmas
361 -> SigD (IfaceSig name tp [] loc)
364 -----------------------------------------------------
365 -- Loading fixity decls
366 -----------------------------------------------------
368 loadFixDecls mod_name decls
369 = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
370 returnRn (mkNameEnv to_add)
372 loadFixDecl mod_name sig@(FixitySig rdr_name fixity loc)
373 = newGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
374 returnRn (name, fixity)
377 -----------------------------------------------------
378 -- Loading instance decls
379 -----------------------------------------------------
381 loadInstDecl :: Module
385 loadInstDecl mod insts decl@(InstDecl inst_ty binds uprags dfun_name src_loc)
387 -- Find out what type constructors and classes are "gates" for the
388 -- instance declaration. If all these "gates" are slurped in then
389 -- we should slurp the instance decl too.
391 -- We *don't* want to count names in the context part as gates, though.
393 -- instance Foo a => Baz (T a) where ...
395 -- Here the gates are Baz and T, but *not* Foo.
397 munged_inst_ty = removeContext inst_ty
398 free_names = extractHsTyRdrNames munged_inst_ty
401 mapRn lookupOrigName free_names `thenRn` \ gate_names ->
402 returnRn ((mkNameSet gate_names, (mod, InstD decl)) `consBag` insts)
405 -- In interface files, the instance decls now look like
406 -- forall a. Foo a -> Baz (T a)
407 -- so we have to strip off function argument types as well
408 -- as the bit before the '=>' (which is always empty in interface files)
409 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
410 removeContext ty = removeFuns ty
412 removeFuns (HsFunTy _ ty) = removeFuns ty
416 -----------------------------------------------------
418 -----------------------------------------------------
420 loadRules :: Module -> IfaceRules
421 -> (Version, [RdrNameRuleDecl])
422 -> RnM d (Version, IfaceRules)
423 loadRules mod rule_bag (version, rules)
424 | null rules || opt_IgnoreIfacePragmas
425 = returnRn (version, rule_bag)
428 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
429 returnRn (version, rule_bag `unionBags` listToBag new_rules)
431 loadRule :: Module -> RdrNameRuleDecl -> RnM d GatedDecl
432 -- "Gate" the rule simply by whether the rule variable is
433 -- needed. We can refine this later.
434 loadRule mod decl@(IfaceRule _ _ var _ _ src_loc)
435 = lookupOrigName var `thenRn` \ var_name ->
436 returnRn (unitNameSet var_name, (mod, RuleD decl))
439 -----------------------------------------------------
440 -- Loading Deprecations
441 -----------------------------------------------------
443 loadDeprecs :: Module -> IfaceDeprecs -> RnM d Deprecations
444 loadDeprecs m Nothing = returnRn NoDeprecs
445 loadDeprecs m (Just (Left txt)) = returnRn (DeprecAll txt)
446 loadDeprecs m (Just (Right prs)) = setModuleRn m $
447 foldlRn loadDeprec emptyNameEnv prs `thenRn` \ env ->
448 returnRn (DeprecSome env)
449 loadDeprec deprec_env (n, txt)
450 = lookupOrigName n `thenRn` \ name ->
451 traceRn (text "Loaded deprecation(s) for" <+> ppr name <> colon <+> ppr txt) `thenRn_`
452 returnRn (extendNameEnv deprec_env name txt)
456 %*********************************************************
458 \subsection{Getting in a declaration}
460 %*********************************************************
463 importDecl :: Name -> RnMG ImportDeclResult
465 data ImportDeclResult
469 | HereItIs (Module, RdrNameHsDecl)
472 = -- Check if it was loaded before beginning this module
473 checkAlreadyAvailable name `thenRn` \ done ->
475 returnRn AlreadySlurped
478 -- Check if we slurped it in while compiling this module
479 getIfacesRn `thenRn` \ ifaces ->
480 if name `elemNameSet` iSlurp ifaces then
481 returnRn AlreadySlurped
484 -- Don't slurp in decls from this module's own interface file
485 -- (Indeed, this shouldn't happen.)
486 if isLocallyDefined name then
487 addWarnRn (importDeclWarn name) `thenRn_`
488 returnRn AlreadySlurped
491 -- When we find a wired-in name we must load its home
492 -- module so that we find any instance decls lurking therein
493 if name `elemNameEnv` wiredInThingEnv then
494 loadHomeInterface doc name `thenRn_`
497 else getNonWiredInDecl name
499 doc = ptext SLIT("need home module for wired in thing") <+> ppr name
501 getNonWiredInDecl :: Name -> RnMG ImportDeclResult
502 getNonWiredInDecl needed_name
503 = traceRn doc_str `thenRn_`
504 loadHomeInterface doc_str needed_name `thenRn` \ ifaces ->
505 case lookupNameEnv (iDecls ifaces) needed_name of
507 {- OMIT DEFERRED STUFF FOR NOW, TILL GHCI WORKS
508 Just (version, avail, is_tycon_name, decl@(_, TyClD (TyData DataType _ _ _ _ ncons _ _ _ _)))
509 -- This case deals with deferred import of algebraic data types
511 | not opt_NoPruneTyDecls
513 && (opt_IgnoreIfacePragmas || ncons > 1)
514 -- We only defer if imported interface pragmas are ingored
515 -- or if it's not a product type.
516 -- Sole reason: The wrapper for a strict function may need to look
517 -- inside its arg, and hence need to see its arg type's constructors.
519 && not (getUnique tycon_name `elem` cCallishTyKeys)
520 -- Never defer ccall types; we have to unbox them,
521 -- and importing them does no harm
524 -> -- OK, so we're importing a deferrable data type
525 if needed_name == tycon_name
526 -- The needed_name is the TyCon of a data type decl
527 -- Record that it's slurped, put it in the deferred set
528 -- and don't return a declaration at all
529 setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces
530 `addOneToNameSet` tycon_name})
531 version (AvailTC needed_name [needed_name])) `thenRn_`
535 -- The needed name is a constructor of a data type decl,
536 -- getting a constructor, so remove the TyCon from the deferred set
537 -- (if it's there) and return the full declaration
538 setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces
539 `delFromNameSet` tycon_name})
540 version avail) `thenRn_`
541 returnRn (HereItIs decl)
543 tycon_name = availName avail
547 -> setIfacesRn (recordSlurp ifaces avail) `thenRn_`
548 returnRn (HereItIs decl)
551 -> addErrRn (getDeclErr needed_name) `thenRn_`
552 returnRn AlreadySlurped
554 doc_str = ptext SLIT("need decl for") <+> ppr needed_name
557 getDeferredDecls :: RnMG [(Module, RdrNameHsDecl)]
559 = getIfacesRn `thenRn` \ ifaces ->
561 decls_map = iDecls ifaces
562 deferred_names = nameSetToList (iDeferred ifaces)
563 get_abstract_decl n = case lookupNameEnv decls_map n of
564 Just (_, _, _, decl) -> decl
566 traceRn (sep [text "getDeferredDecls", nest 4 (fsep (map ppr deferred_names))]) `thenRn_`
567 returnRn (map get_abstract_decl deferred_names)
571 @getWiredInDecl@ maps a wired-in @Name@ to what it makes available.
572 It behaves exactly as if the wired in decl were actually in an interface file.
575 \item if the wired-in name is a data type constructor or a data constructor,
576 it brings in the type constructor and all the data constructors; and
577 marks as ``occurrences'' any free vars of the data con.
579 \item similarly for synonum type constructor
581 \item if the wired-in name is another wired-in Id, it marks as ``occurrences''
582 the free vars of the Id's type.
584 \item it loads the interface file for the wired-in thing for the
585 sole purpose of making sure that its instance declarations are available
587 All this is necessary so that we know all types that are ``in play'', so
588 that we know just what instances to bring into scope.
593 %*********************************************************
595 \subsection{Getting what a module exports}
597 %*********************************************************
599 @getInterfaceExports@ is called only for directly-imported modules.
602 getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, Avails)
603 getInterfaceExports mod_name from
604 = getHomeIfaceTableRn `thenRn` \ hit ->
605 case lookupModuleEnvByName hit mod_name of {
606 Just mi -> returnRn (mi_module mi, mi_exports mi) ;
609 loadInterface doc_str mod_name from `thenRn` \ ifaces ->
610 case lookupModuleEnvByName (iPIT ifaces) mod_name of
611 Just mi -> returnRn (mi_module mi, mi_exports mi) ;
612 -- loadInterface always puts something in the map
613 -- even if it's a fake
614 Nothing -> pprPanic "getInterfaceExports" (ppr mod_name)
617 doc_str = sep [ppr mod_name, ptext SLIT("is directly imported")]
621 %*********************************************************
623 \subsection{Instance declarations are handled specially}
625 %*********************************************************
628 getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)]
629 getImportedInstDecls gates
630 = -- First, load any orphan-instance modules that aren't aready loaded
631 -- Orphan-instance modules are recorded in the module dependecnies
632 getIfacesRn `thenRn` \ ifaces ->
635 [mod | (mod, (True, _, False)) <- fmToList (iImpModInfo ifaces)]
637 loadOrphanModules orphan_mods `thenRn_`
639 -- Now we're ready to grab the instance declarations
640 -- Find the un-gated ones and return them,
641 -- removing them from the bag kept in Ifaces
642 getIfacesRn `thenRn` \ ifaces ->
644 (decls, new_insts) = selectGated gates (iInsts ifaces)
646 setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_`
648 traceRn (sep [text "getImportedInstDecls:",
649 nest 4 (fsep (map ppr gate_list)),
650 text "Slurped" <+> int (length decls) <+> text "instance declarations",
651 nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_`
654 gate_list = nameSetToList gates
656 ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _))
658 HsForAllTy _ _ tau -> ppr tau
661 getImportedRules :: RnMG [(Module,RdrNameHsDecl)]
663 | opt_IgnoreIfacePragmas = returnRn []
665 = getIfacesRn `thenRn` \ ifaces ->
667 gates = iSlurp ifaces -- Anything at all that's been slurped
668 rules = iRules ifaces
669 (decls, new_rules) = selectGated gates rules
674 setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
675 traceRn (sep [text "getImportedRules:",
676 text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
679 selectGated gates decl_bag
680 -- Select only those decls whose gates are *all* in 'gates'
682 | opt_NoPruneDecls -- Just to try the effect of not gating at all
683 = (foldrBag (\ (_,d) ds -> d:ds) [] decl_bag, emptyBag) -- Grab them all
687 = foldrBag select ([], emptyBag) decl_bag
689 select (reqd, decl) (yes, no)
690 | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no)
691 | otherwise = (yes, (reqd,decl) `consBag` no)
693 lookupFixityRn :: Name -> RnMS Fixity
695 | isLocallyDefined name
696 = getFixityEnv `thenRn` \ local_fix_env ->
697 returnRn (lookupLocalFixity local_fix_env name)
699 | otherwise -- Imported
700 -- For imported names, we have to get their fixities by doing a loadHomeInterface,
701 -- and consulting the Ifaces that comes back from that, because the interface
702 -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
703 -- which exports a function 'f', which is defined in module B. Then B isn't loaded
704 -- right away (after all, it's possible that nothing from B will be used).
705 -- When we come across a use of 'f', we need to know its fixity, and it's then,
706 -- and only then, that we load B.hi. That is what's happening here.
707 = getHomeIfaceTableRn `thenRn` \ hit ->
708 loadHomeInterface doc name `thenRn` \ ifaces ->
709 case lookupTable hit (iPIT ifaces) name of
710 Just iface -> returnRn (lookupNameEnv (mi_fixities iface) name `orElse` defaultFixity)
711 Nothing -> returnRn defaultFixity
713 doc = ptext SLIT("Checking fixity for") <+> ppr name
717 %*********************************************************
719 \subsection{Keeping track of what we've slurped, and version numbers}
721 %*********************************************************
723 getImportVersions figures out what the ``usage information'' for this
724 moudule is; that is, what it must record in its interface file as the
725 things it uses. It records:
728 \item (a) anything reachable from its body code
729 \item (b) any module exported with a @module Foo@
730 \item (c) anything reachable from an exported item
733 Why (b)? Because if @Foo@ changes then this module's export list
734 will change, so we must recompile this module at least as far as
735 making a new interface file --- but in practice that means complete
738 Why (c)? Consider this:
740 module A( f, g ) where | module B( f ) where
741 import B( f ) | f = h 3
745 Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
746 @A@'s usages? Our idea is that we aren't going to touch A.hi if it is
747 *identical* to what it was before. If anything about @B.f@ changes
748 than anyone who imports @A@ should be recompiled in case they use
749 @B.f@ (they'll get an early exit if they don't). So, if anything
750 about @B.f@ changes we'd better make sure that something in A.hi
751 changes, and the convenient way to do that is to record the version
752 number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
753 complete recompiation of A, which is overkill but it's the only way to
754 write a new, slightly different, A.hi.
756 But the example is tricker. Even if @B.f@ doesn't change at all,
757 @B.h@ may do so, and this change may not be reflected in @f@'s version
758 number. But with -O, a module that imports A must be recompiled if
759 @B.h@ changes! So A must record a dependency on @B.h@. So we treat
760 the occurrence of @B.f@ in the export list *just as if* it were in the
761 code of A, and thereby haul in all the stuff reachable from it.
763 [NB: If B was compiled with -O, but A isn't, we should really *still*
764 haul in all the unfoldings for B, in case the module that imports A *is*
765 compiled with -O. I think this is the case.]
767 Even if B is used at all we get a usage line for B
768 import B <n> :: ... ;
769 in A.hi, to record the fact that A does import B. This is used to decide
770 to look to look for B.hi rather than B.hi-boot when compiling a module that
771 imports A. This line says that A imports B, but uses nothing in it.
772 So we'll get an early bale-out when compiling A if B's version changes.
775 mkImportInfo :: ModuleName -- Name of this module
776 -> [ImportDecl n] -- The import decls
777 -> RnMG [ImportVersion Name]
779 mkImportInfo this_mod imports
780 = getIfacesRn `thenRn` \ ifaces ->
781 getHomeIfaceTableRn `thenRn` \ hit ->
783 import_all_mods :: [ModuleName]
784 -- Modules where we imported all the names
785 -- (apart from hiding some, perhaps)
786 import_all_mods = nub [ m | ImportDecl m _ _ _ imp_list _ <- imports,
787 import_all imp_list ]
789 import_all (Just (False, _)) = False -- Imports are specified explicitly
790 import_all other = True -- Everything is imported
792 mod_map = iImpModInfo ifaces
793 imp_names = iVSlurp ifaces
796 -- mv_map groups together all the things imported from a particular module.
797 mv_map :: ModuleEnv [Name]
798 mv_map = foldr add_mv emptyModuleEnv imp_names
800 add_mv name mv_map = addItem mv_map (nameModule name) name
802 -- Build the result list by adding info for each module.
803 -- For (a) a library module, we don't record it at all unless it contains orphans
804 -- (We must never lose track of orphans.)
806 -- (b) a source-imported module, don't record the dependency at all
808 -- (b) may seem a bit strange. The idea is that the usages in a .hi file records
809 -- *all* the module's dependencies other than the loop-breakers. We use
810 -- this info in findAndReadInterface to decide whether to look for a .hi file or
813 -- This means we won't track version changes, or orphans, from .hi-boot files.
814 -- The former is potentially rather bad news. It could be fixed by recording
815 -- whether something is a boot file along with the usage info for it, but
816 -- I can't be bothered just now.
818 mk_imp_info mod_name (has_orphans, is_boot, opened) so_far
819 | mod_name == this_mod -- Check if M appears in the set of modules 'below' M
820 -- This seems like a convenient place to check
821 = WARN( not is_boot, ptext SLIT("Wierd:") <+> ppr this_mod <+>
822 ptext SLIT("imports itself (perhaps indirectly)") )
825 | not opened -- We didn't even open the interface
826 = -- This happens when a module, Foo, that we explicitly imported has
827 -- 'import Baz' in its interface file, recording that Baz is below
828 -- Foo in the module dependency hierarchy. We want to propagate this
829 -- information. The Nothing says that we didn't even open the interface
830 -- file but we must still propagate the dependency info.
831 -- The module in question must be a local module (in the same package)
832 go_for_it NothingAtAll
835 | is_lib_module && not has_orphans
838 | is_lib_module -- Record the module version only
839 = go_for_it (Everything module_vers)
842 = go_for_it whats_imported
845 go_for_it exports = (mod_name, has_orphans, is_boot, exports) : so_far
846 mod_iface = lookupIface hit pit mod_name
847 mod = mi_module mod_iface
848 is_lib_module = not (isModuleInThisPackage mod)
849 version_info = mi_version mod_iface
850 version_env = vers_decls version_info
851 module_vers = vers_module version_info
853 whats_imported = Specifically module_vers
854 export_vers import_items
855 (vers_rules version_info)
857 import_items = [(n,v) | n <- lookupWithDefaultModuleEnv mv_map [] mod,
858 let v = lookupNameEnv version_env n `orElse`
859 pprPanic "mk_whats_imported" (ppr n)
861 export_vers | moduleName mod `elem` import_all_mods
862 = Just (vers_exports version_info)
866 import_info = foldFM mk_imp_info [] mod_map
868 traceRn (text "Modules in Ifaces: " <+> fsep (map ppr (keysFM mod_map))) `thenRn_`
872 addItem :: ModuleEnv [a] -> Module -> a -> ModuleEnv [a]
873 addItem fm mod x = extendModuleEnv_C add_item fm mod [x]
880 = getIfacesRn `thenRn` \ ifaces ->
881 returnRn (iSlurp ifaces)
883 recordSlurp ifaces@(Ifaces { iSlurp = slurped_names, iVSlurp = imp_names })
886 new_slurped_names = addAvailToNameSet slurped_names avail
887 new_imp_names = availName avail : imp_names
889 ifaces { iSlurp = new_slurped_names, iVSlurp = new_imp_names }
891 recordLocalSlurps local_avails
892 = getIfacesRn `thenRn` \ ifaces ->
894 new_slurped_names = foldl addAvailToNameSet (iSlurp ifaces) local_avails
896 setIfacesRn (ifaces { iSlurp = new_slurped_names })
900 %*********************************************************
902 \subsection{Getting binders out of a declaration}
904 %*********************************************************
906 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
907 It's used for both source code (from @availsFromDecl@) and interface files
910 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
911 are handled by the sourc-code specific stuff in @RnNames@.
914 getDeclBinders :: (RdrName -> SrcLoc -> RnM d Name) -- New-name function
916 -> RnM d (Maybe AvailInfo)
918 getDeclBinders new_name (TyClD tycl_decl)
919 = mapRn do_one (tyClDeclNames tycl_decl) `thenRn` \ (main_name:sub_names) ->
920 returnRn (Just (AvailTC main_name (main_name : sub_names)))
922 do_one (name,loc) = new_name name loc
924 getDeclBinders new_name (SigD (IfaceSig var ty prags src_loc))
925 = new_name var src_loc `thenRn` \ var_name ->
926 returnRn (Just (Avail var_name))
928 -- foreign declarations
929 getDeclBinders new_name (ForD (ForeignDecl nm kind _ dyn _ loc))
930 | binds_haskell_name kind dyn
931 = new_name nm loc `thenRn` \ name ->
932 returnRn (Just (Avail name))
934 | otherwise -- a foreign export
935 = lookupOrigName nm `thenRn_`
938 getDeclBinders new_name (FixD _) = returnRn Nothing
939 getDeclBinders new_name (DeprecD _) = returnRn Nothing
940 getDeclBinders new_name (DefD _) = returnRn Nothing
941 getDeclBinders new_name (InstD _) = returnRn Nothing
942 getDeclBinders new_name (RuleD _) = returnRn Nothing
944 binds_haskell_name (FoImport _) _ = True
945 binds_haskell_name FoLabel _ = True
946 binds_haskell_name FoExport ext_nm = isDynamicExtName ext_nm
949 @getDeclSysBinders@ gets the implicit binders introduced by a decl.
950 A the moment that's just the tycon and datacon that come with a class decl.
951 They aren't returned by @getDeclBinders@ because they aren't in scope;
952 but they {\em should} be put into the @DeclsMap@ of this module.
954 Note that this excludes the default-method names of a class decl,
955 and the dict fun of an instance decl, because both of these have
956 bindings of their own elsewhere.
959 getDeclSysBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ names src_loc))
960 = sequenceRn [new_name n src_loc | n <- names]
962 getDeclSysBinders new_name (TyClD (TyData _ _ _ _ cons _ _ _ _ _))
963 = sequenceRn [new_name wkr_name src_loc | ConDecl _ wkr_name _ _ _ src_loc <- cons]
965 getDeclSysBinders new_name other_decl
969 %*********************************************************
971 \subsection{Reading an interface file}
973 %*********************************************************
976 findAndReadIface :: SDoc -> ModuleName
977 -> IsBootInterface -- True <=> Look for a .hi-boot file
978 -- False <=> Look for .hi file
979 -> RnM d (Either Message (Module, ParsedIface))
980 -- Nothing <=> file not found, or unreadable, or illegible
981 -- Just x <=> successfully found and parsed
983 findAndReadIface doc_str mod_name hi_boot_file
984 = traceRn trace_msg `thenRn_`
985 -- we keep two maps for interface files,
986 -- one for 'normal' ones, the other for .hi-boot files,
987 -- hence the need to signal which kind we're interested.
989 getFinderRn `thenRn` \ finder ->
990 ioToRnM (finder mod_name) `thenRn` \ maybe_found ->
993 Right (Just (mod,locn))
994 | hi_boot_file -> readIface mod (hi_file locn ++ "-hi-boot")
995 | otherwise -> readIface mod (hi_file locn)
998 other -> traceRn (ptext SLIT("...not found")) `thenRn_`
999 returnRn (Left (noIfaceErr mod_name hi_boot_file))
1002 trace_msg = sep [hsep [ptext SLIT("Reading"),
1003 if hi_boot_file then ptext SLIT("[boot]") else empty,
1004 ptext SLIT("interface for"),
1005 ppr mod_name <> semi],
1006 nest 4 (ptext SLIT("reason:") <+> doc_str)]
1009 @readIface@ tries just the one file.
1012 readIface :: Module -> String -> RnM d (Either Message (Module, ParsedIface))
1013 -- Nothing <=> file not found, or unreadable, or illegible
1014 -- Just x <=> successfully found and parsed
1015 readIface wanted_mod file_path
1016 = traceRn (ptext SLIT("...reading from") <+> text file_path) `thenRn_`
1017 ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
1020 case parseIface contents
1021 PState{ bol = 0#, atbol = 1#,
1024 loc = mkSrcLoc (mkFastString file_path) 1 } of
1025 POk _ (PIface iface) ->
1026 warnCheckRn (wanted_mod == read_mod)
1027 (hiModuleNameMismatchWarn wanted_mod read_mod) `thenRn_`
1028 returnRn (Right (wanted_mod, iface))
1030 read_mod = pi_mod iface
1032 PFailed err -> bale_out err
1033 parse_result -> bale_out empty
1034 -- This last case can happen if the interface file is (say) empty
1035 -- in which case the parser thinks it looks like an IdInfo or
1036 -- something like that. Just an artefact of the fact that the
1037 -- parser is used for several purposes at once.
1039 Left io_err -> bale_out (text (show io_err))
1041 bale_out err = returnRn (Left (badIfaceFile file_path err))
1044 %*********************************************************
1048 %*********************************************************
1051 noIfaceErr mod_name boot_file
1052 = ptext SLIT("Could not find interface file for") <+> quotes (ppr mod_name)
1053 -- We used to print the search path, but we can't do that
1054 -- now, becuase it's hidden inside the finder.
1055 -- Maybe the finder should expose more functions.
1057 badIfaceFile file err
1058 = vcat [ptext SLIT("Bad interface file:") <+> text file,
1062 = vcat [ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name),
1063 ptext SLIT("from module") <+> quotes (ppr (nameModule name))
1068 "Compiler tried to import decl from interface file with same name as module."),
1070 "(possible cause: module name clashes with interface file already in scope.)")
1072 hsep [ptext SLIT("name:"), quotes (ppr name)]
1074 warnRedundantSourceImport mod_name
1075 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
1076 <+> quotes (ppr mod_name)
1078 hiModuleNameMismatchWarn :: Module -> Module -> Message
1079 hiModuleNameMismatchWarn requested_mod read_mod =
1080 hsep [ ptext SLIT("Something is amiss; requested module name")
1081 , ppr (moduleName requested_mod)
1082 , ptext SLIT("differs from name found in the interface file")