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 )
25 import HsSyn ( HsDecl(..), TyClDecl(..), InstDecl(..), IfaceSig(..),
26 HsType(..), ConDecl(..), IE(..), ConDetails(..), Sig(..),
27 ForeignDecl(..), ForKind(..), isDynamicExtName,
28 FixitySig(..), RuleDecl(..),
29 isClassOpSig, DeprecDecl(..)
31 import HsImpExp ( ImportDecl(..), ieNames )
32 import CoreSyn ( CoreRule )
33 import BasicTypes ( Version, defaultFixity )
34 import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameRuleDecl,
35 RdrNameDeprecation, RdrNameIE,
40 import ParseIface ( parseIface, IfaceStuff(..) )
42 import Name ( Name {-instance NamedThing-}, nameOccName,
43 nameModule, isLocallyDefined,
45 mkNameEnv, elemNameEnv, extendNameEnv
47 import Module ( Module, ModuleEnv,
48 moduleName, isModuleInThisPackage,
49 ModuleName, WhereFrom(..),
50 emptyModuleEnv, extendModuleEnv, lookupModuleEnv, lookupModuleEnvByName,
51 extendModuleEnv_C, lookupWithDefaultModuleEnv
53 import RdrName ( RdrName, rdrNameOcc )
55 import SrcLoc ( mkSrcLoc, SrcLoc )
56 import PrelInfo ( cCallishTyKeys, wiredInThingEnv )
57 import Maybes ( maybeToBool, orElse )
58 import StringBuffer ( hGetStringBuffer )
59 import FastString ( mkFastString )
60 import ErrUtils ( Message )
61 import Util ( sortLt )
72 %*********************************************************
74 \subsection{Loading a new interface file}
76 %*********************************************************
79 loadHomeInterface :: SDoc -> Name -> RnM d Ifaces
80 loadHomeInterface doc_str name
81 = loadInterface doc_str (moduleName (nameModule name)) ImportBySystem
83 loadOrphanModules :: [ModuleName] -> RnM d ()
84 loadOrphanModules mods
85 | null mods = returnRn ()
86 | otherwise = traceRn (text "Loading orphan modules:" <+>
87 fsep (map ppr mods)) `thenRn_`
88 mapRn_ load mods `thenRn_`
91 load mod = loadInterface (mk_doc mod) mod ImportBySystem
92 mk_doc mod = ppr mod <+> ptext SLIT("is a orphan-instance module")
95 loadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d Ifaces
96 loadInterface doc mod from
97 = tryLoadInterface doc mod from `thenRn` \ (ifaces, maybe_err) ->
99 Nothing -> returnRn ifaces
100 Just err -> failWithRn ifaces err
102 tryLoadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d (Ifaces, Maybe Message)
103 -- Returns (Just err) if an error happened
104 -- Guarantees to return with iImpModInfo m --> (... Just cts)
105 -- (If the load fails, we plug in a vanilla placeholder
106 tryLoadInterface doc_str mod_name from
107 = getIfacesRn `thenRn` \ ifaces ->
109 mod_map = iImpModInfo ifaces
110 mod_info = lookupFM mod_map mod_name
113 = case (from, mod_info) of
114 (ImportByUser, _) -> False -- Not hi-boot
115 (ImportByUserSource, _) -> True -- hi-boot
116 (ImportBySystem, Just (_, is_boot, _)) -> is_boot --
117 (ImportBySystem, Nothing) -> False
118 -- We're importing a module we know absolutely
119 -- nothing about, so we assume it's from
120 -- another package, where we aren't doing
121 -- dependency tracking. So it won't be a hi-boot file.
123 redundant_source_import
124 = case (from, mod_info) of
125 (ImportByUserSource, Just (_,False,_)) -> True
128 -- CHECK WHETHER WE HAVE IT ALREADY
131 -> -- We're read it already so don't re-read it
132 returnRn (ifaces, Nothing) ;
136 -- Issue a warning for a redundant {- SOURCE -} import
137 -- NB that we arrange to read all the ordinary imports before
138 -- any of the {- SOURCE -} imports
139 warnCheckRn (not redundant_source_import)
140 (warnRedundantSourceImport mod_name) `thenRn_`
142 -- READ THE MODULE IN
143 findAndReadIface doc_str mod_name hi_boot_file `thenRn` \ read_result ->
144 case read_result of {
145 Left err -> -- Not found, so add an empty export env to the Ifaces map
146 -- so that we don't look again
148 new_mod_map = addToFM mod_map mod_name (False, False, True)
149 new_ifaces = ifaces { iImpModInfo = new_mod_map }
151 setIfacesRn new_ifaces `thenRn_`
152 returnRn (new_ifaces, Just err) ;
155 Right (mod, iface) ->
157 -- LOAD IT INTO Ifaces
159 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
160 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
161 -- If we do loadExport first the wrong info gets into the cache (unless we
162 -- explicitly tag each export which seems a bit of a bore)
165 -- Sanity check. If we're system-importing a module we know nothing at all
166 -- about, it should be from a different package to this one
167 WARN( not (maybeToBool mod_info) &&
168 case from of { ImportBySystem -> True; other -> False } &&
169 isModuleInThisPackage mod,
172 loadDecls mod (iDecls ifaces) (pi_decls iface) `thenRn` \ (decls_vers, new_decls) ->
173 loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ (rule_vers, new_rules) ->
174 loadFixDecls mod_name (pi_fixity iface) `thenRn` \ fix_env ->
175 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
176 foldlRn (loadInstDecl mod) (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
177 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
179 version = VersionInfo { vers_module = pi_vers iface,
180 vers_exports = export_vers,
181 vers_rules = rule_vers,
182 vers_decls = decls_vers }
184 -- For an explicit user import, add to mod_map info about
185 -- the things the imported module depends on, extracted
186 -- from its usage info.
187 mod_map1 = case from of
188 ImportByUser -> addModDeps mod (pi_usages iface) mod_map
190 mod_map2 = addToFM mod_map1 mod_name (has_orphans, hi_boot_file, True)
192 -- Now add info about this module to the PIT
193 has_orphans = pi_orphan iface
194 new_pit = extendModuleEnv (iPIT ifaces) mod mod_iface
195 mod_iface = ModIface { mi_module = mod, mi_version = version,
196 mi_exports = avails, mi_orphan = has_orphans,
197 mi_fixities = fix_env, mi_deprecs = deprec_env,
198 mi_usages = [], -- Will be filled in later
199 mi_decls = panic "No mi_decls in PIT",
200 mi_globals = panic "No mi_globals in PIT"
203 new_ifaces = ifaces { iPIT = new_pit,
207 iImpModInfo = mod_map2 }
209 setIfacesRn new_ifaces `thenRn_`
210 returnRn (new_ifaces, Nothing)
213 -----------------------------------------------------
214 -- Adding module dependencies from the
215 -- import decls in the interface file
216 -----------------------------------------------------
218 addModDeps :: Module -> [ImportVersion a]
219 -> ImportedModuleInfo -> ImportedModuleInfo
220 -- (addModDeps M ivs deps)
221 -- We are importing module M, and M.hi contains 'import' decls given by ivs
222 addModDeps mod new_deps mod_deps
223 = foldr add mod_deps filtered_new_deps
225 -- Don't record dependencies when importing a module from another package
226 -- Except for its descendents which contain orphans,
227 -- and in that case, forget about the boot indicator
228 filtered_new_deps :: [(ModuleName, (WhetherHasOrphans, IsBootInterface, IsLoaded))]
230 | isModuleInThisPackage mod
231 = [ (imp_mod, (has_orphans, is_boot, False))
232 | (imp_mod, has_orphans, is_boot, _) <- new_deps
234 | otherwise = [ (imp_mod, (True, False, False))
235 | (imp_mod, has_orphans, _, _) <- new_deps,
238 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
240 combine old@(_, old_is_boot, old_is_loaded) new
241 | old_is_loaded || not old_is_boot = old -- Keep the old info if it's already loaded
242 -- or if it's a non-boot pending load
243 | otherwise = new -- Otherwise pick new info
246 -----------------------------------------------------
247 -- Loading the export list
248 -----------------------------------------------------
250 loadExports :: (Version, [ExportItem]) -> RnM d (Version, Avails)
251 loadExports (vers, items)
252 = getModuleRn `thenRn` \ this_mod ->
253 mapRn (loadExport this_mod) items `thenRn` \ avails_s ->
254 returnRn (vers, concat avails_s)
257 loadExport :: Module -> ExportItem -> RnM d [AvailInfo]
258 loadExport this_mod (mod, entities)
259 | mod == moduleName this_mod = returnRn []
260 -- If the module exports anything defined in this module, just ignore it.
261 -- Reason: otherwise it looks as if there are two local definition sites
262 -- for the thing, and an error gets reported. Easiest thing is just to
263 -- filter them out up front. This situation only arises if a module
264 -- imports itself, or another module that imported it. (Necessarily,
265 -- this invoves a loop.) Consequence: if you say
270 -- module B( AType ) where
271 -- import {-# SOURCE #-} A( AType )
273 -- then you'll get a 'B does not export AType' message. A bit bogus
274 -- but it's a bogus thing to do!
277 = mapRn (load_entity mod) entities
279 new_name mod occ = newGlobalName mod occ
281 load_entity mod (Avail occ)
282 = new_name mod occ `thenRn` \ name ->
283 returnRn (Avail name)
284 load_entity mod (AvailTC occ occs)
285 = new_name mod occ `thenRn` \ name ->
286 mapRn (new_name mod) occs `thenRn` \ names ->
287 returnRn (AvailTC name names)
290 -----------------------------------------------------
291 -- Loading type/class/value decls
292 -----------------------------------------------------
296 -> [(Version, RdrNameHsDecl)]
297 -> RnM d (NameEnv Version, DeclsMap)
298 loadDecls mod decls_map decls
299 = foldlRn (loadDecl mod) (emptyNameEnv, decls_map) decls
302 -> (NameEnv Version, DeclsMap)
303 -> (Version, RdrNameHsDecl)
304 -> RnM d (NameEnv Version, DeclsMap)
305 loadDecl mod (version_map, decls_map) (version, decl)
306 = getDeclBinders new_name decl `thenRn` \ maybe_avail ->
307 case maybe_avail of {
308 Nothing -> returnRn (version_map, decls_map); -- No bindings
311 getDeclSysBinders new_name decl `thenRn` \ sys_bndrs ->
313 full_avail = addSysAvails avail sys_bndrs
314 -- Add the sys-binders to avail. When we import the decl,
315 -- it's full_avail that will get added to the 'already-slurped' set (iSlurp)
316 -- If we miss out sys-binders, we'll read the decl multiple times!
318 main_name = availName avail
319 new_decls_map = foldl add_decl decls_map
320 [ (name, (full_avail, name==main_name, (mod, decl')))
321 | name <- availNames full_avail]
322 add_decl decls_map (name, stuff)
323 = WARN( name `elemNameEnv` decls_map, ppr name )
324 extendNameEnv decls_map name stuff
326 new_version_map = extendNameEnv version_map main_name version
328 returnRn (new_version_map, new_decls_map)
331 -- newTopBinder puts into the cache the binder with the
332 -- module information set correctly. When the decl is later renamed,
333 -- the binding site will thereby get the correct module.
334 -- There maybe occurrences that don't have the correct Module, but
335 -- by the typechecker will propagate the binding definition to all
336 -- the occurrences, so that doesn't matter
337 new_name rdr_name loc = newTopBinder mod rdr_name loc
340 If a signature decl is being loaded, and optIgnoreIfacePragmas is on,
341 we toss away unfolding information.
343 Also, if the signature is loaded from a module we're importing from source,
344 we do the same. This is to avoid situations when compiling a pair of mutually
345 recursive modules, peering at unfolding info in the interface file of the other,
346 e.g., you compile A, it looks at B's interface file and may as a result change
347 its interface file. Hence, B is recompiled, maybe changing its interface file,
348 which will the unfolding info used in A to become invalid. Simple way out is to
349 just ignore unfolding info.
351 [Jan 99: I junked the second test above. If we're importing from an hi-boot
352 file there isn't going to *be* any pragma info. Maybe the above comment
353 dates from a time where we picked up a .hi file first if it existed?]
356 SigD (IfaceSig name tp ls loc) | opt_IgnoreIfacePragmas
357 -> SigD (IfaceSig name tp [] loc)
360 -----------------------------------------------------
361 -- Loading fixity decls
362 -----------------------------------------------------
364 loadFixDecls mod_name decls
365 = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
366 returnRn (mkNameEnv to_add)
368 loadFixDecl mod_name sig@(FixitySig rdr_name fixity loc)
369 = newGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
370 returnRn (name, fixity)
373 -----------------------------------------------------
374 -- Loading instance decls
375 -----------------------------------------------------
377 loadInstDecl :: Module
381 loadInstDecl mod insts decl@(InstDecl inst_ty binds uprags dfun_name src_loc)
383 -- Find out what type constructors and classes are "gates" for the
384 -- instance declaration. If all these "gates" are slurped in then
385 -- we should slurp the instance decl too.
387 -- We *don't* want to count names in the context part as gates, though.
389 -- instance Foo a => Baz (T a) where ...
391 -- Here the gates are Baz and T, but *not* Foo.
393 munged_inst_ty = removeContext inst_ty
394 free_names = extractHsTyRdrNames munged_inst_ty
397 mapRn lookupOrigName free_names `thenRn` \ gate_names ->
398 returnRn ((mkNameSet gate_names, (mod, InstD decl)) `consBag` insts)
401 -- In interface files, the instance decls now look like
402 -- forall a. Foo a -> Baz (T a)
403 -- so we have to strip off function argument types as well
404 -- as the bit before the '=>' (which is always empty in interface files)
405 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
406 removeContext ty = removeFuns ty
408 removeFuns (HsFunTy _ ty) = removeFuns ty
412 -----------------------------------------------------
414 -----------------------------------------------------
416 loadRules :: Module -> IfaceRules
417 -> (Version, [RdrNameRuleDecl])
418 -> RnM d (Version, IfaceRules)
419 loadRules mod rule_bag (version, rules)
420 | null rules || opt_IgnoreIfacePragmas
421 = returnRn (version, rule_bag)
424 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
425 returnRn (version, rule_bag `unionBags` listToBag new_rules)
427 loadRule :: Module -> RdrNameRuleDecl -> RnM d GatedDecl
428 -- "Gate" the rule simply by whether the rule variable is
429 -- needed. We can refine this later.
430 loadRule mod decl@(IfaceRule _ _ var _ _ src_loc)
431 = lookupOrigName var `thenRn` \ var_name ->
432 returnRn (unitNameSet var_name, (mod, RuleD decl))
435 -----------------------------------------------------
436 -- Loading Deprecations
437 -----------------------------------------------------
439 loadDeprecs :: Module -> [RdrNameDeprecation] -> RnM d Deprecations
440 loadDeprecs m [] = returnRn NoDeprecs
441 loadDeprecs m [Deprecation (IEModuleContents _) txt _] = returnRn (DeprecAll txt)
442 loadDeprecs m deprecs = setModuleRn m $
443 foldlRn loadDeprec emptyNameEnv deprecs `thenRn` \ env ->
444 returnRn (DeprecSome env)
445 loadDeprec deprec_env (Deprecation ie txt _)
446 = mapRn lookupOrigName (ieNames ie) `thenRn` \ names ->
447 traceRn (text "Loaded deprecation(s) for" <+> hcat (punctuate comma (map ppr names)) <> colon <+> ppr txt) `thenRn_`
448 returnRn (extendNameEnvList deprec_env (zip names (repeat txt)))
452 %*********************************************************
454 \subsection{Getting in a declaration}
456 %*********************************************************
459 importDecl :: Name -> RnMG ImportDeclResult
461 data ImportDeclResult
465 | HereItIs (Module, RdrNameHsDecl)
468 = -- Check if it was loaded before beginning this module
469 checkAlreadyAvailable name `thenRn` \ done ->
471 returnRn AlreadySlurped
474 -- Check if we slurped it in while compiling this module
475 getIfacesRn `thenRn` \ ifaces ->
476 if name `elemNameSet` iSlurp ifaces then
477 returnRn AlreadySlurped
480 -- Don't slurp in decls from this module's own interface file
481 -- (Indeed, this shouldn't happen.)
482 if isLocallyDefined name then
483 addWarnRn (importDeclWarn name) `thenRn_`
484 returnRn AlreadySlurped
487 -- When we find a wired-in name we must load its home
488 -- module so that we find any instance decls lurking therein
489 if name `elemNameEnv` wiredInThingEnv then
490 loadHomeInterface doc name `thenRn_`
493 else getNonWiredInDecl name
495 doc = ptext SLIT("need home module for wired in thing") <+> ppr name
497 getNonWiredInDecl :: Name -> RnMG ImportDeclResult
498 getNonWiredInDecl needed_name
499 = traceRn doc_str `thenRn_`
500 loadHomeInterface doc_str needed_name `thenRn` \ ifaces ->
501 case lookupNameEnv (iDecls ifaces) needed_name of
503 {- OMIT DEFERRED STUFF FOR NOW, TILL GHCI WORKS
504 Just (version, avail, is_tycon_name, decl@(_, TyClD (TyData DataType _ _ _ _ ncons _ _ _ _ _)))
505 -- This case deals with deferred import of algebraic data types
507 | not opt_NoPruneTyDecls
509 && (opt_IgnoreIfacePragmas || ncons > 1)
510 -- We only defer if imported interface pragmas are ingored
511 -- or if it's not a product type.
512 -- Sole reason: The wrapper for a strict function may need to look
513 -- inside its arg, and hence need to see its arg type's constructors.
515 && not (getUnique tycon_name `elem` cCallishTyKeys)
516 -- Never defer ccall types; we have to unbox them,
517 -- and importing them does no harm
520 -> -- OK, so we're importing a deferrable data type
521 if needed_name == tycon_name
522 -- The needed_name is the TyCon of a data type decl
523 -- Record that it's slurped, put it in the deferred set
524 -- and don't return a declaration at all
525 setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces
526 `addOneToNameSet` tycon_name})
527 version (AvailTC needed_name [needed_name])) `thenRn_`
531 -- The needed name is a constructor of a data type decl,
532 -- getting a constructor, so remove the TyCon from the deferred set
533 -- (if it's there) and return the full declaration
534 setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces
535 `delFromNameSet` tycon_name})
536 version avail) `thenRn_`
537 returnRn (HereItIs decl)
539 tycon_name = availName avail
543 -> setIfacesRn (recordSlurp ifaces avail) `thenRn_`
544 returnRn (HereItIs decl)
547 -> addErrRn (getDeclErr needed_name) `thenRn_`
548 returnRn AlreadySlurped
550 doc_str = ptext SLIT("need decl for") <+> ppr needed_name
553 getDeferredDecls :: RnMG [(Module, RdrNameHsDecl)]
555 = getIfacesRn `thenRn` \ ifaces ->
557 decls_map = iDecls ifaces
558 deferred_names = nameSetToList (iDeferred ifaces)
559 get_abstract_decl n = case lookupNameEnv decls_map n of
560 Just (_, _, _, decl) -> decl
562 traceRn (sep [text "getDeferredDecls", nest 4 (fsep (map ppr deferred_names))]) `thenRn_`
563 returnRn (map get_abstract_decl deferred_names)
567 @getWiredInDecl@ maps a wired-in @Name@ to what it makes available.
568 It behaves exactly as if the wired in decl were actually in an interface file.
571 \item if the wired-in name is a data type constructor or a data constructor,
572 it brings in the type constructor and all the data constructors; and
573 marks as ``occurrences'' any free vars of the data con.
575 \item similarly for synonum type constructor
577 \item if the wired-in name is another wired-in Id, it marks as ``occurrences''
578 the free vars of the Id's type.
580 \item it loads the interface file for the wired-in thing for the
581 sole purpose of making sure that its instance declarations are available
583 All this is necessary so that we know all types that are ``in play'', so
584 that we know just what instances to bring into scope.
589 %*********************************************************
591 \subsection{Getting what a module exports}
593 %*********************************************************
595 @getInterfaceExports@ is called only for directly-imported modules.
598 getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, Avails)
599 getInterfaceExports mod_name from
600 = getHomeIfaceTableRn `thenRn` \ hit ->
601 case lookupModuleEnvByName hit mod_name of {
602 Just mi -> returnRn (mi_module mi, mi_exports mi) ;
605 loadInterface doc_str mod_name from `thenRn` \ ifaces ->
606 case lookupModuleEnvByName (iPIT ifaces) mod_name of
607 Just mi -> returnRn (mi_module mi, mi_exports mi) ;
608 -- loadInterface always puts something in the map
609 -- even if it's a fake
610 Nothing -> pprPanic "getInterfaceExports" (ppr mod_name)
613 doc_str = sep [ppr mod_name, ptext SLIT("is directly imported")]
617 %*********************************************************
619 \subsection{Instance declarations are handled specially}
621 %*********************************************************
624 getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)]
625 getImportedInstDecls gates
626 = -- First, load any orphan-instance modules that aren't aready loaded
627 -- Orphan-instance modules are recorded in the module dependecnies
628 getIfacesRn `thenRn` \ ifaces ->
631 [mod | (mod, (True, _, False)) <- fmToList (iImpModInfo ifaces)]
633 loadOrphanModules orphan_mods `thenRn_`
635 -- Now we're ready to grab the instance declarations
636 -- Find the un-gated ones and return them,
637 -- removing them from the bag kept in Ifaces
638 getIfacesRn `thenRn` \ ifaces ->
640 (decls, new_insts) = selectGated gates (iInsts ifaces)
642 setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_`
644 traceRn (sep [text "getImportedInstDecls:",
645 nest 4 (fsep (map ppr gate_list)),
646 text "Slurped" <+> int (length decls) <+> text "instance declarations",
647 nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_`
650 gate_list = nameSetToList gates
652 ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _))
654 HsForAllTy _ _ tau -> ppr tau
657 getImportedRules :: RnMG [(Module,RdrNameHsDecl)]
659 | opt_IgnoreIfacePragmas = returnRn []
661 = getIfacesRn `thenRn` \ ifaces ->
663 gates = iSlurp ifaces -- Anything at all that's been slurped
664 rules = iRules ifaces
665 (decls, new_rules) = selectGated gates rules
670 setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
671 traceRn (sep [text "getImportedRules:",
672 text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
675 selectGated gates decl_bag
676 -- Select only those decls whose gates are *all* in 'gates'
678 | opt_NoPruneDecls -- Just to try the effect of not gating at all
679 = (foldrBag (\ (_,d) ds -> d:ds) [] decl_bag, emptyBag) -- Grab them all
683 = foldrBag select ([], emptyBag) decl_bag
685 select (reqd, decl) (yes, no)
686 | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no)
687 | otherwise = (yes, (reqd,decl) `consBag` no)
689 lookupFixityRn :: Name -> RnMS Fixity
691 | isLocallyDefined name
692 = getFixityEnv `thenRn` \ local_fix_env ->
693 returnRn (lookupLocalFixity local_fix_env name)
695 | otherwise -- Imported
696 -- For imported names, we have to get their fixities by doing a loadHomeInterface,
697 -- and consulting the Ifaces that comes back from that, because the interface
698 -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
699 -- which exports a function 'f', which is defined in module B. Then B isn't loaded
700 -- right away (after all, it's possible that nothing from B will be used).
701 -- When we come across a use of 'f', we need to know its fixity, and it's then,
702 -- and only then, that we load B.hi. That is what's happening here.
703 = getHomeIfaceTableRn `thenRn` \ hst ->
704 case lookupFixityEnv hst name of {
705 Just fixity -> returnRn fixity ;
708 loadHomeInterface doc name `thenRn` \ ifaces ->
709 returnRn (lookupFixityEnv (iPIT ifaces) name `orElse` defaultFixity)
712 doc = ptext SLIT("Checking fixity for") <+> ppr name
716 %*********************************************************
718 \subsection{Keeping track of what we've slurped, and version numbers}
720 %*********************************************************
722 getImportVersions figures out what the ``usage information'' for this
723 moudule is; that is, what it must record in its interface file as the
724 things it uses. It records:
727 \item (a) anything reachable from its body code
728 \item (b) any module exported with a @module Foo@
729 \item (c) anything reachable from an exported item
732 Why (b)? Because if @Foo@ changes then this module's export list
733 will change, so we must recompile this module at least as far as
734 making a new interface file --- but in practice that means complete
737 Why (c)? Consider this:
739 module A( f, g ) where | module B( f ) where
740 import B( f ) | f = h 3
744 Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
745 @A@'s usages? Our idea is that we aren't going to touch A.hi if it is
746 *identical* to what it was before. If anything about @B.f@ changes
747 than anyone who imports @A@ should be recompiled in case they use
748 @B.f@ (they'll get an early exit if they don't). So, if anything
749 about @B.f@ changes we'd better make sure that something in A.hi
750 changes, and the convenient way to do that is to record the version
751 number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
752 complete recompiation of A, which is overkill but it's the only way to
753 write a new, slightly different, A.hi.
755 But the example is tricker. Even if @B.f@ doesn't change at all,
756 @B.h@ may do so, and this change may not be reflected in @f@'s version
757 number. But with -O, a module that imports A must be recompiled if
758 @B.h@ changes! So A must record a dependency on @B.h@. So we treat
759 the occurrence of @B.f@ in the export list *just as if* it were in the
760 code of A, and thereby haul in all the stuff reachable from it.
762 [NB: If B was compiled with -O, but A isn't, we should really *still*
763 haul in all the unfoldings for B, in case the module that imports A *is*
764 compiled with -O. I think this is the case.]
766 Even if B is used at all we get a usage line for B
767 import B <n> :: ... ;
768 in A.hi, to record the fact that A does import B. This is used to decide
769 to look to look for B.hi rather than B.hi-boot when compiling a module that
770 imports A. This line says that A imports B, but uses nothing in it.
771 So we'll get an early bale-out when compiling A if B's version changes.
774 mkImportInfo :: ModuleName -- Name of this module
775 -> [ImportDecl n] -- The import decls
776 -> RnMG [ImportVersion Name]
778 mkImportInfo this_mod imports
779 = getIfacesRn `thenRn` \ ifaces ->
780 getHomeIfaceTableRn `thenRn` \ hit ->
782 import_all_mods :: [ModuleName]
783 -- Modules where we imported all the names
784 -- (apart from hiding some, perhaps)
785 import_all_mods = nub [ m | ImportDecl m _ _ _ imp_list _ <- imports,
786 import_all imp_list ]
788 import_all (Just (False, _)) = False -- Imports are specified explicitly
789 import_all other = True -- Everything is imported
791 mod_map = iImpModInfo ifaces
792 imp_names = iVSlurp ifaces
795 -- mv_map groups together all the things imported from a particular module.
796 mv_map :: ModuleEnv [Name]
797 mv_map = foldr add_mv emptyModuleEnv imp_names
799 add_mv name mv_map = addItem mv_map (nameModule name) name
801 -- Build the result list by adding info for each module.
802 -- For (a) a library module, we don't record it at all unless it contains orphans
803 -- (We must never lose track of orphans.)
805 -- (b) a source-imported module, don't record the dependency at all
807 -- (b) may seem a bit strange. The idea is that the usages in a .hi file records
808 -- *all* the module's dependencies other than the loop-breakers. We use
809 -- this info in findAndReadInterface to decide whether to look for a .hi file or
812 -- This means we won't track version changes, or orphans, from .hi-boot files.
813 -- The former is potentially rather bad news. It could be fixed by recording
814 -- whether something is a boot file along with the usage info for it, but
815 -- I can't be bothered just now.
817 mk_imp_info mod_name (has_orphans, is_boot, opened) so_far
818 | mod_name == this_mod -- Check if M appears in the set of modules 'below' M
819 -- This seems like a convenient place to check
820 = WARN( not is_boot, ptext SLIT("Wierd:") <+> ppr this_mod <+>
821 ptext SLIT("imports itself (perhaps indirectly)") )
824 | not opened -- We didn't even open the interface
825 = -- This happens when a module, Foo, that we explicitly imported has
826 -- 'import Baz' in its interface file, recording that Baz is below
827 -- Foo in the module dependency hierarchy. We want to propagate this
828 -- information. The Nothing says that we didn't even open the interface
829 -- file but we must still propagate the dependency info.
830 -- The module in question must be a local module (in the same package)
831 go_for_it NothingAtAll
834 | is_lib_module && not has_orphans
837 | is_lib_module -- Record the module version only
838 = go_for_it (Everything module_vers)
841 = go_for_it whats_imported
844 go_for_it exports = (mod_name, has_orphans, is_boot, exports) : so_far
845 mod_iface = lookupIface hit pit mod_name
846 mod = mi_module mod_iface
847 is_lib_module = not (isModuleInThisPackage mod)
848 version_info = mi_version mod_iface
849 version_env = vers_decls version_info
850 module_vers = vers_module version_info
852 whats_imported = Specifically module_vers
853 export_vers import_items
854 (vers_rules version_info)
856 import_items = [(n,v) | n <- lookupWithDefaultModuleEnv mv_map [] mod,
857 let v = lookupNameEnv version_env n `orElse`
858 pprPanic "mk_whats_imported" (ppr n)
860 export_vers | moduleName mod `elem` import_all_mods
861 = Just (vers_exports version_info)
865 import_info = foldFM mk_imp_info [] mod_map
867 traceRn (text "Modules in Ifaces: " <+> fsep (map ppr (keysFM mod_map))) `thenRn_`
871 addItem :: ModuleEnv [a] -> Module -> a -> ModuleEnv [a]
872 addItem fm mod x = extendModuleEnv_C add_item fm mod [x]
879 = getIfacesRn `thenRn` \ ifaces ->
880 returnRn (iSlurp ifaces)
882 recordSlurp ifaces@(Ifaces { iSlurp = slurped_names, iVSlurp = imp_names })
885 new_slurped_names = addAvailToNameSet slurped_names avail
886 new_imp_names = availName avail : imp_names
888 ifaces { iSlurp = new_slurped_names, iVSlurp = new_imp_names }
890 recordLocalSlurps local_avails
891 = getIfacesRn `thenRn` \ ifaces ->
893 new_slurped_names = foldl addAvailToNameSet (iSlurp ifaces) local_avails
895 setIfacesRn (ifaces { iSlurp = new_slurped_names })
899 %*********************************************************
901 \subsection{Getting binders out of a declaration}
903 %*********************************************************
905 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
906 It's used for both source code (from @availsFromDecl@) and interface files
909 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
910 are handled by the sourc-code specific stuff in @RnNames@.
913 getDeclBinders :: (RdrName -> SrcLoc -> RnM d Name) -- New-name function
915 -> RnM d (Maybe AvailInfo)
917 getDeclBinders new_name (TyClD (TyData _ _ tycon _ condecls _ _ _ src_loc _ _))
918 = new_name tycon src_loc `thenRn` \ tycon_name ->
919 getConFieldNames new_name condecls `thenRn` \ sub_names ->
920 returnRn (Just (AvailTC tycon_name (tycon_name : nub sub_names)))
921 -- The "nub" is because getConFieldNames can legitimately return duplicates,
922 -- when a record declaration has the same field in multiple constructors
924 getDeclBinders new_name (TyClD (TySynonym tycon _ _ src_loc))
925 = new_name tycon src_loc `thenRn` \ tycon_name ->
926 returnRn (Just (AvailTC tycon_name [tycon_name]))
928 getDeclBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ _ src_loc))
929 = new_name cname src_loc `thenRn` \ class_name ->
931 -- Record the names for the class ops
933 -- just want class-op sigs
934 op_sigs = filter isClassOpSig sigs
936 mapRn (getClassOpNames new_name) op_sigs `thenRn` \ sub_names ->
938 returnRn (Just (AvailTC class_name (class_name : sub_names)))
940 getDeclBinders new_name (SigD (IfaceSig var ty prags src_loc))
941 = new_name var src_loc `thenRn` \ var_name ->
942 returnRn (Just (Avail var_name))
944 getDeclBinders new_name (FixD _) = returnRn Nothing
945 getDeclBinders new_name (DeprecD _) = returnRn Nothing
947 -- foreign declarations
948 getDeclBinders new_name (ForD (ForeignDecl nm kind _ dyn _ loc))
949 | binds_haskell_name kind dyn
950 = new_name nm loc `thenRn` \ name ->
951 returnRn (Just (Avail name))
953 | otherwise -- a foreign export
954 = lookupOrigName nm `thenRn_`
957 getDeclBinders new_name (DefD _) = returnRn Nothing
958 getDeclBinders new_name (InstD _) = returnRn Nothing
959 getDeclBinders new_name (RuleD _) = returnRn Nothing
961 binds_haskell_name (FoImport _) _ = True
962 binds_haskell_name FoLabel _ = True
963 binds_haskell_name FoExport ext_nm = isDynamicExtName ext_nm
966 getConFieldNames new_name (ConDecl con _ _ _ (RecCon fielddecls) src_loc : rest)
967 = mapRn (\n -> new_name n src_loc) (con:fields) `thenRn` \ cfs ->
968 getConFieldNames new_name rest `thenRn` \ ns ->
971 fields = concat (map fst fielddecls)
973 getConFieldNames new_name (ConDecl con _ _ _ condecl src_loc : rest)
974 = new_name con src_loc `thenRn` \ n ->
975 getConFieldNames new_name rest `thenRn` \ ns ->
978 getConFieldNames new_name [] = returnRn []
980 getClassOpNames new_name (ClassOpSig op _ _ src_loc) = new_name op src_loc
983 @getDeclSysBinders@ gets the implicit binders introduced by a decl.
984 A the moment that's just the tycon and datacon that come with a class decl.
985 They aren't returned by @getDeclBinders@ because they aren't in scope;
986 but they {\em should} be put into the @DeclsMap@ of this module.
988 Note that this excludes the default-method names of a class decl,
989 and the dict fun of an instance decl, because both of these have
990 bindings of their own elsewhere.
993 getDeclSysBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ names
995 = sequenceRn [new_name n src_loc | n <- names]
997 getDeclSysBinders new_name (TyClD (TyData _ _ _ _ cons _ _ _ _ _ _))
998 = sequenceRn [new_name wkr_name src_loc | ConDecl _ wkr_name _ _ _ src_loc <- cons]
1000 getDeclSysBinders new_name other_decl
1004 %*********************************************************
1006 \subsection{Reading an interface file}
1008 %*********************************************************
1011 findAndReadIface :: SDoc -> ModuleName
1012 -> IsBootInterface -- True <=> Look for a .hi-boot file
1013 -- False <=> Look for .hi file
1014 -> RnM d (Either Message (Module, ParsedIface))
1015 -- Nothing <=> file not found, or unreadable, or illegible
1016 -- Just x <=> successfully found and parsed
1018 findAndReadIface doc_str mod_name hi_boot_file
1019 = traceRn trace_msg `thenRn_`
1020 -- we keep two maps for interface files,
1021 -- one for 'normal' ones, the other for .hi-boot files,
1022 -- hence the need to signal which kind we're interested.
1024 getFinderRn `thenRn` \ finder ->
1025 ioToRnM (finder mod_name) `thenRn` \ maybe_found ->
1028 Right (Just (mod,locn))
1029 | hi_boot_file -> readIface mod (hi_file locn ++ "-hi-boot")
1030 | otherwise -> readIface mod (hi_file locn)
1033 other -> traceRn (ptext SLIT("...not found")) `thenRn_`
1034 returnRn (Left (noIfaceErr mod_name hi_boot_file))
1037 trace_msg = sep [hsep [ptext SLIT("Reading"),
1038 if hi_boot_file then ptext SLIT("[boot]") else empty,
1039 ptext SLIT("interface for"),
1040 ppr mod_name <> semi],
1041 nest 4 (ptext SLIT("reason:") <+> doc_str)]
1044 @readIface@ tries just the one file.
1047 readIface :: Module -> String -> RnM d (Either Message (Module, ParsedIface))
1048 -- Nothing <=> file not found, or unreadable, or illegible
1049 -- Just x <=> successfully found and parsed
1050 readIface wanted_mod file_path
1051 = traceRn (ptext SLIT("...reading from") <+> text file_path) `thenRn_`
1052 ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
1055 case parseIface contents
1056 PState{ bol = 0#, atbol = 1#,
1059 loc = mkSrcLoc (mkFastString file_path) 1 } of
1060 POk _ (PIface iface) ->
1061 warnCheckRn (wanted_mod == read_mod)
1062 (hiModuleNameMismatchWarn wanted_mod read_mod) `thenRn_`
1063 returnRn (Right (wanted_mod, iface))
1065 read_mod = pi_mod iface
1067 PFailed err -> bale_out err
1068 parse_result -> bale_out empty
1069 -- This last case can happen if the interface file is (say) empty
1070 -- in which case the parser thinks it looks like an IdInfo or
1071 -- something like that. Just an artefact of the fact that the
1072 -- parser is used for several purposes at once.
1074 Left io_err -> bale_out (text (show io_err))
1076 bale_out err = returnRn (Left (badIfaceFile file_path err))
1079 %*********************************************************
1083 %*********************************************************
1086 noIfaceErr mod_name boot_file
1087 = ptext SLIT("Could not find interface file for") <+> quotes (ppr mod_name)
1088 -- We used to print the search path, but we can't do that
1089 -- now, becuase it's hidden inside the finder.
1090 -- Maybe the finder should expose more functions.
1092 badIfaceFile file err
1093 = vcat [ptext SLIT("Bad interface file:") <+> text file,
1097 = vcat [ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name),
1098 ptext SLIT("from module") <+> quotes (ppr (nameModule name))
1103 "Compiler tried to import decl from interface file with same name as module."),
1105 "(possible cause: module name clashes with interface file already in scope.)")
1107 hsep [ptext SLIT("name:"), quotes (ppr name)]
1109 warnRedundantSourceImport mod_name
1110 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
1111 <+> quotes (ppr mod_name)
1113 hiModuleNameMismatchWarn :: Module -> Module -> Message
1114 hiModuleNameMismatchWarn requested_mod read_mod =
1115 hsep [ ptext SLIT("Something is amiss; requested module name")
1116 , ppr (moduleName requested_mod)
1117 , ptext SLIT("differs from name found in the interface file")