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 --> (... Just cts)
102 -- (If the load fails, we plug in a vanilla placeholder
103 tryLoadInterface doc_str mod_name from
104 = getIfacesRn `thenRn` \ ifaces ->
106 mod_map = iImpModInfo ifaces
107 mod_info = lookupFM mod_map mod_name
110 = case (from, mod_info) of
111 (ImportByUser, _) -> False -- Not hi-boot
112 (ImportByUserSource, _) -> True -- hi-boot
113 (ImportBySystem, Just (_, is_boot, _)) -> is_boot --
114 (ImportBySystem, Nothing) -> False
115 -- We're importing a module we know absolutely
116 -- nothing about, so we assume it's from
117 -- another package, where we aren't doing
118 -- dependency tracking. So it won't be a hi-boot file.
120 redundant_source_import
121 = case (from, mod_info) of
122 (ImportByUserSource, Just (_,False,_)) -> True
125 -- CHECK WHETHER WE HAVE IT ALREADY
128 -> -- We're read it already so don't re-read it
129 returnRn (ifaces, Nothing) ;
133 -- Issue a warning for a redundant {- SOURCE -} import
134 -- NB that we arrange to read all the ordinary imports before
135 -- any of the {- SOURCE -} imports
136 warnCheckRn (not redundant_source_import)
137 (warnRedundantSourceImport mod_name) `thenRn_`
139 -- READ THE MODULE IN
140 findAndReadIface doc_str mod_name hi_boot_file `thenRn` \ read_result ->
141 case read_result of {
142 Left err -> -- Not found, so add an empty export env to the Ifaces map
143 -- so that we don't look again
145 new_mod_map = addToFM mod_map mod_name (False, False, True)
146 new_ifaces = ifaces { iImpModInfo = new_mod_map }
148 setIfacesRn new_ifaces `thenRn_`
149 returnRn (new_ifaces, Just err) ;
152 Right (mod, iface) ->
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)
162 -- Sanity check. If we're system-importing a module we know nothing at all
163 -- about, it should be from a different package to this one
164 WARN( not (maybeToBool mod_info) &&
165 case from of { ImportBySystem -> True; other -> False } &&
166 isModuleInThisPackage mod,
169 loadDecls mod (iDecls ifaces) (pi_decls iface) `thenRn` \ (decls_vers, new_decls) ->
170 loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ (rule_vers, new_rules) ->
171 loadFixDecls mod_name (pi_fixity iface) `thenRn` \ fix_env ->
172 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
173 foldlRn (loadInstDecl mod) (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
174 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
176 version = VersionInfo { vers_module = pi_vers iface,
177 vers_exports = export_vers,
178 vers_rules = rule_vers,
179 vers_decls = decls_vers }
181 -- For an explicit user import, add to mod_map info about
182 -- the things the imported module depends on, extracted
183 -- from its usage info.
184 mod_map1 = case from of
185 ImportByUser -> addModDeps mod (pi_usages iface) mod_map
187 mod_map2 = addToFM mod_map1 mod_name (has_orphans, hi_boot_file, True)
189 -- Now add info about this module to the PIT
190 has_orphans = pi_orphan iface
191 new_pit = extendModuleEnv (iPIT ifaces) mod mod_iface
192 mod_iface = ModIface { mi_module = mod, mi_version = version,
193 mi_exports = avails, mi_orphan = has_orphans,
194 mi_fixities = fix_env, mi_deprecs = deprec_env,
195 mi_usages = [], -- Will be filled in later
196 mi_decls = panic "No mi_decls in PIT",
197 mi_globals = panic "No mi_globals in PIT"
200 new_ifaces = ifaces { iPIT = new_pit,
204 iImpModInfo = mod_map2 }
206 setIfacesRn new_ifaces `thenRn_`
207 returnRn (new_ifaces, Nothing)
210 -----------------------------------------------------
211 -- Adding module dependencies from the
212 -- import decls in the interface file
213 -----------------------------------------------------
215 addModDeps :: Module -> [ImportVersion a]
216 -> ImportedModuleInfo -> ImportedModuleInfo
217 -- (addModDeps M ivs deps)
218 -- We are importing module M, and M.hi contains 'import' decls given by ivs
219 addModDeps mod new_deps mod_deps
220 = foldr add mod_deps filtered_new_deps
222 -- Don't record dependencies when importing a module from another package
223 -- Except for its descendents which contain orphans,
224 -- and in that case, forget about the boot indicator
225 filtered_new_deps :: [(ModuleName, (WhetherHasOrphans, IsBootInterface, IsLoaded))]
227 | isModuleInThisPackage mod
228 = [ (imp_mod, (has_orphans, is_boot, False))
229 | (imp_mod, has_orphans, is_boot, _) <- new_deps
231 | otherwise = [ (imp_mod, (True, False, False))
232 | (imp_mod, has_orphans, _, _) <- new_deps,
235 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
237 combine old@(_, old_is_boot, old_is_loaded) new
238 | old_is_loaded || not old_is_boot = old -- Keep the old info if it's already loaded
239 -- or if it's a non-boot pending load
240 | otherwise = new -- Otherwise pick new info
243 -----------------------------------------------------
244 -- Loading the export list
245 -----------------------------------------------------
247 loadExports :: (Version, [ExportItem]) -> RnM d (Version, Avails)
248 loadExports (vers, items)
249 = getModuleRn `thenRn` \ this_mod ->
250 mapRn (loadExport this_mod) items `thenRn` \ avails_s ->
251 returnRn (vers, concat avails_s)
254 loadExport :: Module -> ExportItem -> RnM d [AvailInfo]
255 loadExport this_mod (mod, entities)
256 | mod == moduleName this_mod = returnRn []
257 -- If the module exports anything defined in this module, just ignore it.
258 -- Reason: otherwise it looks as if there are two local definition sites
259 -- for the thing, and an error gets reported. Easiest thing is just to
260 -- filter them out up front. This situation only arises if a module
261 -- imports itself, or another module that imported it. (Necessarily,
262 -- this invoves a loop.) Consequence: if you say
267 -- module B( AType ) where
268 -- import {-# SOURCE #-} A( AType )
270 -- then you'll get a 'B does not export AType' message. A bit bogus
271 -- but it's a bogus thing to do!
274 = mapRn (load_entity mod) entities
276 new_name mod occ = newGlobalName mod occ
278 load_entity mod (Avail occ)
279 = new_name mod occ `thenRn` \ name ->
280 returnRn (Avail name)
281 load_entity mod (AvailTC occ occs)
282 = new_name mod occ `thenRn` \ name ->
283 mapRn (new_name mod) occs `thenRn` \ names ->
284 returnRn (AvailTC name names)
287 -----------------------------------------------------
288 -- Loading type/class/value decls
289 -----------------------------------------------------
293 -> [(Version, RdrNameHsDecl)]
294 -> RnM d (NameEnv Version, DeclsMap)
295 loadDecls mod decls_map decls
296 = foldlRn (loadDecl mod) (emptyNameEnv, decls_map) decls
299 -> (NameEnv Version, DeclsMap)
300 -> (Version, RdrNameHsDecl)
301 -> RnM d (NameEnv Version, DeclsMap)
302 loadDecl mod (version_map, decls_map) (version, decl)
303 = getDeclBinders new_name decl `thenRn` \ maybe_avail ->
304 case maybe_avail of {
305 Nothing -> returnRn (version_map, decls_map); -- No bindings
308 getDeclSysBinders new_name decl `thenRn` \ sys_bndrs ->
310 full_avail = addSysAvails avail sys_bndrs
311 -- Add the sys-binders to avail. When we import the decl,
312 -- it's full_avail that will get added to the 'already-slurped' set (iSlurp)
313 -- If we miss out sys-binders, we'll read the decl multiple times!
315 main_name = availName avail
316 new_decls_map = foldl add_decl decls_map
317 [ (name, (full_avail, name==main_name, (mod, decl')))
318 | name <- availNames full_avail]
319 add_decl decls_map (name, stuff)
320 = WARN( name `elemNameEnv` decls_map, ppr name )
321 extendNameEnv decls_map name stuff
323 new_version_map = extendNameEnv version_map main_name version
325 returnRn (new_version_map, new_decls_map)
328 -- newTopBinder puts into the cache the binder with the
329 -- module information set correctly. When the decl is later renamed,
330 -- the binding site will thereby get the correct module.
331 -- There maybe occurrences that don't have the correct Module, but
332 -- by the typechecker will propagate the binding definition to all
333 -- the occurrences, so that doesn't matter
334 new_name rdr_name loc = newTopBinder mod rdr_name loc
337 If a signature decl is being loaded, and optIgnoreIfacePragmas is on,
338 we toss away unfolding information.
340 Also, if the signature is loaded from a module we're importing from source,
341 we do the same. This is to avoid situations when compiling a pair of mutually
342 recursive modules, peering at unfolding info in the interface file of the other,
343 e.g., you compile A, it looks at B's interface file and may as a result change
344 its interface file. Hence, B is recompiled, maybe changing its interface file,
345 which will the unfolding info used in A to become invalid. Simple way out is to
346 just ignore unfolding info.
348 [Jan 99: I junked the second test above. If we're importing from an hi-boot
349 file there isn't going to *be* any pragma info. Maybe the above comment
350 dates from a time where we picked up a .hi file first if it existed?]
353 SigD (IfaceSig name tp ls loc) | opt_IgnoreIfacePragmas
354 -> SigD (IfaceSig name tp [] loc)
357 -----------------------------------------------------
358 -- Loading fixity decls
359 -----------------------------------------------------
361 loadFixDecls mod_name decls
362 = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
363 returnRn (mkNameEnv to_add)
365 loadFixDecl mod_name sig@(FixitySig rdr_name fixity loc)
366 = newGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
367 returnRn (name, fixity)
370 -----------------------------------------------------
371 -- Loading instance decls
372 -----------------------------------------------------
374 loadInstDecl :: Module
378 loadInstDecl mod insts decl@(InstDecl inst_ty binds uprags dfun_name src_loc)
380 -- Find out what type constructors and classes are "gates" for the
381 -- instance declaration. If all these "gates" are slurped in then
382 -- we should slurp the instance decl too.
384 -- We *don't* want to count names in the context part as gates, though.
386 -- instance Foo a => Baz (T a) where ...
388 -- Here the gates are Baz and T, but *not* Foo.
390 munged_inst_ty = removeContext inst_ty
391 free_names = extractHsTyRdrNames munged_inst_ty
394 mapRn lookupOrigName free_names `thenRn` \ gate_names ->
395 returnRn ((mkNameSet gate_names, (mod, InstD decl)) `consBag` insts)
398 -- In interface files, the instance decls now look like
399 -- forall a. Foo a -> Baz (T a)
400 -- so we have to strip off function argument types as well
401 -- as the bit before the '=>' (which is always empty in interface files)
402 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
403 removeContext ty = removeFuns ty
405 removeFuns (HsFunTy _ ty) = removeFuns ty
409 -----------------------------------------------------
411 -----------------------------------------------------
413 loadRules :: Module -> IfaceRules
414 -> (Version, [RdrNameRuleDecl])
415 -> RnM d (Version, IfaceRules)
416 loadRules mod rule_bag (version, rules)
417 | null rules || opt_IgnoreIfacePragmas
418 = returnRn (version, rule_bag)
421 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
422 returnRn (version, rule_bag `unionBags` listToBag new_rules)
424 loadRule :: Module -> RdrNameRuleDecl -> RnM d GatedDecl
425 -- "Gate" the rule simply by whether the rule variable is
426 -- needed. We can refine this later.
427 loadRule mod decl@(IfaceRule _ _ var _ _ src_loc)
428 = lookupOrigName var `thenRn` \ var_name ->
429 returnRn (unitNameSet var_name, (mod, RuleD decl))
432 -----------------------------------------------------
433 -- Loading Deprecations
434 -----------------------------------------------------
436 loadDeprecs :: Module -> IfaceDeprecs -> RnM d Deprecations
437 loadDeprecs m Nothing = returnRn NoDeprecs
438 loadDeprecs m (Just (Left txt)) = returnRn (DeprecAll txt)
439 loadDeprecs m (Just (Right prs)) = setModuleRn m $
440 foldlRn loadDeprec emptyNameEnv prs `thenRn` \ env ->
441 returnRn (DeprecSome env)
442 loadDeprec deprec_env (n, txt)
443 = lookupOrigName n `thenRn` \ name ->
444 traceRn (text "Loaded deprecation(s) for" <+> ppr name <> colon <+> ppr txt) `thenRn_`
445 returnRn (extendNameEnv deprec_env name txt)
449 %*********************************************************
451 \subsection{Getting in a declaration}
453 %*********************************************************
456 importDecl :: Name -> RnMG ImportDeclResult
458 data ImportDeclResult
462 | HereItIs (Module, RdrNameHsDecl)
465 = -- Check if it was loaded before beginning this module
466 checkAlreadyAvailable name `thenRn` \ done ->
468 returnRn AlreadySlurped
471 -- Check if we slurped it in while compiling this module
472 getIfacesRn `thenRn` \ ifaces ->
473 if name `elemNameSet` iSlurp ifaces then
474 returnRn AlreadySlurped
477 -- Don't slurp in decls from this module's own interface file
478 -- (Indeed, this shouldn't happen.)
479 if isLocallyDefined name then
480 addWarnRn (importDeclWarn name) `thenRn_`
481 returnRn AlreadySlurped
484 -- When we find a wired-in name we must load its home
485 -- module so that we find any instance decls lurking therein
486 if name `elemNameEnv` wiredInThingEnv then
487 loadHomeInterface doc name `thenRn_`
490 else getNonWiredInDecl name
492 doc = ptext SLIT("need home module for wired in thing") <+> ppr name
494 getNonWiredInDecl :: Name -> RnMG ImportDeclResult
495 getNonWiredInDecl needed_name
496 = traceRn doc_str `thenRn_`
497 loadHomeInterface doc_str needed_name `thenRn` \ ifaces ->
498 case lookupNameEnv (iDecls ifaces) needed_name of
500 {- OMIT DEFERRED STUFF FOR NOW, TILL GHCI WORKS
501 Just (version, avail, is_tycon_name, decl@(_, TyClD (TyData DataType _ _ _ _ ncons _ _ _ _)))
502 -- This case deals with deferred import of algebraic data types
504 | not opt_NoPruneTyDecls
506 && (opt_IgnoreIfacePragmas || ncons > 1)
507 -- We only defer if imported interface pragmas are ingored
508 -- or if it's not a product type.
509 -- Sole reason: The wrapper for a strict function may need to look
510 -- inside its arg, and hence need to see its arg type's constructors.
512 && not (getUnique tycon_name `elem` cCallishTyKeys)
513 -- Never defer ccall types; we have to unbox them,
514 -- and importing them does no harm
517 -> -- OK, so we're importing a deferrable data type
518 if needed_name == tycon_name
519 -- The needed_name is the TyCon of a data type decl
520 -- Record that it's slurped, put it in the deferred set
521 -- and don't return a declaration at all
522 setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces
523 `addOneToNameSet` tycon_name})
524 version (AvailTC needed_name [needed_name])) `thenRn_`
528 -- The needed name is a constructor of a data type decl,
529 -- getting a constructor, so remove the TyCon from the deferred set
530 -- (if it's there) and return the full declaration
531 setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces
532 `delFromNameSet` tycon_name})
533 version avail) `thenRn_`
534 returnRn (HereItIs decl)
536 tycon_name = availName avail
540 -> setIfacesRn (recordSlurp ifaces avail) `thenRn_`
541 returnRn (HereItIs decl)
544 -> addErrRn (getDeclErr needed_name) `thenRn_`
545 returnRn AlreadySlurped
547 doc_str = ptext SLIT("need decl for") <+> ppr needed_name
550 getDeferredDecls :: RnMG [(Module, RdrNameHsDecl)]
552 = getIfacesRn `thenRn` \ ifaces ->
554 decls_map = iDecls ifaces
555 deferred_names = nameSetToList (iDeferred ifaces)
556 get_abstract_decl n = case lookupNameEnv decls_map n of
557 Just (_, _, _, decl) -> decl
559 traceRn (sep [text "getDeferredDecls", nest 4 (fsep (map ppr deferred_names))]) `thenRn_`
560 returnRn (map get_abstract_decl deferred_names)
564 @getWiredInDecl@ maps a wired-in @Name@ to what it makes available.
565 It behaves exactly as if the wired in decl were actually in an interface file.
568 \item if the wired-in name is a data type constructor or a data constructor,
569 it brings in the type constructor and all the data constructors; and
570 marks as ``occurrences'' any free vars of the data con.
572 \item similarly for synonum type constructor
574 \item if the wired-in name is another wired-in Id, it marks as ``occurrences''
575 the free vars of the Id's type.
577 \item it loads the interface file for the wired-in thing for the
578 sole purpose of making sure that its instance declarations are available
580 All this is necessary so that we know all types that are ``in play'', so
581 that we know just what instances to bring into scope.
586 %*********************************************************
588 \subsection{Getting what a module exports}
590 %*********************************************************
592 @getInterfaceExports@ is called only for directly-imported modules.
595 getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, Avails)
596 getInterfaceExports mod_name from
597 = getHomeIfaceTableRn `thenRn` \ hit ->
598 case lookupModuleEnvByName hit mod_name of {
599 Just mi -> returnRn (mi_module mi, mi_exports mi) ;
602 loadInterface doc_str mod_name from `thenRn` \ ifaces ->
603 case lookupModuleEnvByName (iPIT ifaces) mod_name of
604 Just mi -> returnRn (mi_module mi, mi_exports mi) ;
605 -- loadInterface always puts something in the map
606 -- even if it's a fake
607 Nothing -> pprPanic "getInterfaceExports" (ppr mod_name)
610 doc_str = sep [ppr mod_name, ptext SLIT("is directly imported")]
614 %*********************************************************
616 \subsection{Instance declarations are handled specially}
618 %*********************************************************
621 getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)]
622 getImportedInstDecls gates
623 = -- First, load any orphan-instance modules that aren't aready loaded
624 -- Orphan-instance modules are recorded in the module dependecnies
625 getIfacesRn `thenRn` \ ifaces ->
628 [mod | (mod, (True, _, False)) <- fmToList (iImpModInfo ifaces)]
630 loadOrphanModules orphan_mods `thenRn_`
632 -- Now we're ready to grab the instance declarations
633 -- Find the un-gated ones and return them,
634 -- removing them from the bag kept in Ifaces
635 getIfacesRn `thenRn` \ ifaces ->
637 (decls, new_insts) = selectGated gates (iInsts ifaces)
639 setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_`
641 traceRn (sep [text "getImportedInstDecls:",
642 nest 4 (fsep (map ppr gate_list)),
643 text "Slurped" <+> int (length decls) <+> text "instance declarations",
644 nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_`
647 gate_list = nameSetToList gates
649 ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _))
651 HsForAllTy _ _ tau -> ppr tau
654 getImportedRules :: RnMG [(Module,RdrNameHsDecl)]
656 | opt_IgnoreIfacePragmas = returnRn []
658 = getIfacesRn `thenRn` \ ifaces ->
660 gates = iSlurp ifaces -- Anything at all that's been slurped
661 rules = iRules ifaces
662 (decls, new_rules) = selectGated gates rules
667 setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
668 traceRn (sep [text "getImportedRules:",
669 text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
672 selectGated gates decl_bag
673 -- Select only those decls whose gates are *all* in 'gates'
675 | opt_NoPruneDecls -- Just to try the effect of not gating at all
676 = (foldrBag (\ (_,d) ds -> d:ds) [] decl_bag, emptyBag) -- Grab them all
680 = foldrBag select ([], emptyBag) decl_bag
682 select (reqd, decl) (yes, no)
683 | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no)
684 | otherwise = (yes, (reqd,decl) `consBag` no)
686 lookupFixityRn :: Name -> RnMS Fixity
688 | isLocallyDefined name
689 = getFixityEnv `thenRn` \ local_fix_env ->
690 returnRn (lookupLocalFixity local_fix_env name)
692 | otherwise -- Imported
693 -- For imported names, we have to get their fixities by doing a loadHomeInterface,
694 -- and consulting the Ifaces that comes back from that, because the interface
695 -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
696 -- which exports a function 'f', which is defined in module B. Then B isn't loaded
697 -- right away (after all, it's possible that nothing from B will be used).
698 -- When we come across a use of 'f', we need to know its fixity, and it's then,
699 -- and only then, that we load B.hi. That is what's happening here.
700 = getHomeIfaceTableRn `thenRn` \ hst ->
701 case lookupFixityEnv hst name of {
702 Just fixity -> returnRn fixity ;
705 loadHomeInterface doc name `thenRn` \ ifaces ->
706 returnRn (lookupFixityEnv (iPIT ifaces) name `orElse` defaultFixity)
709 doc = ptext SLIT("Checking fixity for") <+> ppr name
713 %*********************************************************
715 \subsection{Keeping track of what we've slurped, and version numbers}
717 %*********************************************************
719 getImportVersions figures out what the ``usage information'' for this
720 moudule is; that is, what it must record in its interface file as the
721 things it uses. It records:
724 \item (a) anything reachable from its body code
725 \item (b) any module exported with a @module Foo@
726 \item (c) anything reachable from an exported item
729 Why (b)? Because if @Foo@ changes then this module's export list
730 will change, so we must recompile this module at least as far as
731 making a new interface file --- but in practice that means complete
734 Why (c)? Consider this:
736 module A( f, g ) where | module B( f ) where
737 import B( f ) | f = h 3
741 Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
742 @A@'s usages? Our idea is that we aren't going to touch A.hi if it is
743 *identical* to what it was before. If anything about @B.f@ changes
744 than anyone who imports @A@ should be recompiled in case they use
745 @B.f@ (they'll get an early exit if they don't). So, if anything
746 about @B.f@ changes we'd better make sure that something in A.hi
747 changes, and the convenient way to do that is to record the version
748 number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
749 complete recompiation of A, which is overkill but it's the only way to
750 write a new, slightly different, A.hi.
752 But the example is tricker. Even if @B.f@ doesn't change at all,
753 @B.h@ may do so, and this change may not be reflected in @f@'s version
754 number. But with -O, a module that imports A must be recompiled if
755 @B.h@ changes! So A must record a dependency on @B.h@. So we treat
756 the occurrence of @B.f@ in the export list *just as if* it were in the
757 code of A, and thereby haul in all the stuff reachable from it.
759 [NB: If B was compiled with -O, but A isn't, we should really *still*
760 haul in all the unfoldings for B, in case the module that imports A *is*
761 compiled with -O. I think this is the case.]
763 Even if B is used at all we get a usage line for B
764 import B <n> :: ... ;
765 in A.hi, to record the fact that A does import B. This is used to decide
766 to look to look for B.hi rather than B.hi-boot when compiling a module that
767 imports A. This line says that A imports B, but uses nothing in it.
768 So we'll get an early bale-out when compiling A if B's version changes.
771 mkImportInfo :: ModuleName -- Name of this module
772 -> [ImportDecl n] -- The import decls
773 -> RnMG [ImportVersion Name]
775 mkImportInfo this_mod imports
776 = getIfacesRn `thenRn` \ ifaces ->
777 getHomeIfaceTableRn `thenRn` \ hit ->
779 import_all_mods :: [ModuleName]
780 -- Modules where we imported all the names
781 -- (apart from hiding some, perhaps)
782 import_all_mods = nub [ m | ImportDecl m _ _ _ imp_list _ <- imports,
783 import_all imp_list ]
785 import_all (Just (False, _)) = False -- Imports are specified explicitly
786 import_all other = True -- Everything is imported
788 mod_map = iImpModInfo ifaces
789 imp_names = iVSlurp ifaces
792 -- mv_map groups together all the things imported from a particular module.
793 mv_map :: ModuleEnv [Name]
794 mv_map = foldr add_mv emptyModuleEnv imp_names
796 add_mv name mv_map = addItem mv_map (nameModule name) name
798 -- Build the result list by adding info for each module.
799 -- For (a) a library module, we don't record it at all unless it contains orphans
800 -- (We must never lose track of orphans.)
802 -- (b) a source-imported module, don't record the dependency at all
804 -- (b) may seem a bit strange. The idea is that the usages in a .hi file records
805 -- *all* the module's dependencies other than the loop-breakers. We use
806 -- this info in findAndReadInterface to decide whether to look for a .hi file or
809 -- This means we won't track version changes, or orphans, from .hi-boot files.
810 -- The former is potentially rather bad news. It could be fixed by recording
811 -- whether something is a boot file along with the usage info for it, but
812 -- I can't be bothered just now.
814 mk_imp_info mod_name (has_orphans, is_boot, opened) so_far
815 | mod_name == this_mod -- Check if M appears in the set of modules 'below' M
816 -- This seems like a convenient place to check
817 = WARN( not is_boot, ptext SLIT("Wierd:") <+> ppr this_mod <+>
818 ptext SLIT("imports itself (perhaps indirectly)") )
821 | not opened -- We didn't even open the interface
822 = -- This happens when a module, Foo, that we explicitly imported has
823 -- 'import Baz' in its interface file, recording that Baz is below
824 -- Foo in the module dependency hierarchy. We want to propagate this
825 -- information. The Nothing says that we didn't even open the interface
826 -- file but we must still propagate the dependency info.
827 -- The module in question must be a local module (in the same package)
828 go_for_it NothingAtAll
831 | is_lib_module && not has_orphans
834 | is_lib_module -- Record the module version only
835 = go_for_it (Everything module_vers)
838 = go_for_it whats_imported
841 go_for_it exports = (mod_name, has_orphans, is_boot, exports) : so_far
842 mod_iface = lookupIface hit pit mod_name
843 mod = mi_module mod_iface
844 is_lib_module = not (isModuleInThisPackage mod)
845 version_info = mi_version mod_iface
846 version_env = vers_decls version_info
847 module_vers = vers_module version_info
849 whats_imported = Specifically module_vers
850 export_vers import_items
851 (vers_rules version_info)
853 import_items = [(n,v) | n <- lookupWithDefaultModuleEnv mv_map [] mod,
854 let v = lookupNameEnv version_env n `orElse`
855 pprPanic "mk_whats_imported" (ppr n)
857 export_vers | moduleName mod `elem` import_all_mods
858 = Just (vers_exports version_info)
862 import_info = foldFM mk_imp_info [] mod_map
864 traceRn (text "Modules in Ifaces: " <+> fsep (map ppr (keysFM mod_map))) `thenRn_`
868 addItem :: ModuleEnv [a] -> Module -> a -> ModuleEnv [a]
869 addItem fm mod x = extendModuleEnv_C add_item fm mod [x]
876 = getIfacesRn `thenRn` \ ifaces ->
877 returnRn (iSlurp ifaces)
879 recordSlurp ifaces@(Ifaces { iSlurp = slurped_names, iVSlurp = imp_names })
882 new_slurped_names = addAvailToNameSet slurped_names avail
883 new_imp_names = availName avail : imp_names
885 ifaces { iSlurp = new_slurped_names, iVSlurp = new_imp_names }
887 recordLocalSlurps local_avails
888 = getIfacesRn `thenRn` \ ifaces ->
890 new_slurped_names = foldl addAvailToNameSet (iSlurp ifaces) local_avails
892 setIfacesRn (ifaces { iSlurp = new_slurped_names })
896 %*********************************************************
898 \subsection{Getting binders out of a declaration}
900 %*********************************************************
902 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
903 It's used for both source code (from @availsFromDecl@) and interface files
906 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
907 are handled by the sourc-code specific stuff in @RnNames@.
910 getDeclBinders :: (RdrName -> SrcLoc -> RnM d Name) -- New-name function
912 -> RnM d (Maybe AvailInfo)
914 getDeclBinders new_name (TyClD tycl_decl)
915 = mapRn do_one (tyClDeclNames tycl_decl) `thenRn` \ (main_name:sub_names) ->
916 returnRn (Just (AvailTC main_name (main_name : sub_names)))
918 do_one (name,loc) = new_name name loc
920 getDeclBinders new_name (SigD (IfaceSig var ty prags src_loc))
921 = new_name var src_loc `thenRn` \ var_name ->
922 returnRn (Just (Avail var_name))
924 -- foreign declarations
925 getDeclBinders new_name (ForD (ForeignDecl nm kind _ dyn _ loc))
926 | binds_haskell_name kind dyn
927 = new_name nm loc `thenRn` \ name ->
928 returnRn (Just (Avail name))
930 | otherwise -- a foreign export
931 = lookupOrigName nm `thenRn_`
934 getDeclBinders new_name (FixD _) = returnRn Nothing
935 getDeclBinders new_name (DeprecD _) = returnRn Nothing
936 getDeclBinders new_name (DefD _) = returnRn Nothing
937 getDeclBinders new_name (InstD _) = returnRn Nothing
938 getDeclBinders new_name (RuleD _) = returnRn Nothing
940 binds_haskell_name (FoImport _) _ = True
941 binds_haskell_name FoLabel _ = True
942 binds_haskell_name FoExport ext_nm = isDynamicExtName ext_nm
945 @getDeclSysBinders@ gets the implicit binders introduced by a decl.
946 A the moment that's just the tycon and datacon that come with a class decl.
947 They aren't returned by @getDeclBinders@ because they aren't in scope;
948 but they {\em should} be put into the @DeclsMap@ of this module.
950 Note that this excludes the default-method names of a class decl,
951 and the dict fun of an instance decl, because both of these have
952 bindings of their own elsewhere.
955 getDeclSysBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ names src_loc))
956 = sequenceRn [new_name n src_loc | n <- names]
958 getDeclSysBinders new_name (TyClD (TyData _ _ _ _ cons _ _ _ _ _))
959 = sequenceRn [new_name wkr_name src_loc | ConDecl _ wkr_name _ _ _ src_loc <- cons]
961 getDeclSysBinders new_name other_decl
965 %*********************************************************
967 \subsection{Reading an interface file}
969 %*********************************************************
972 findAndReadIface :: SDoc -> ModuleName
973 -> IsBootInterface -- True <=> Look for a .hi-boot file
974 -- False <=> Look for .hi file
975 -> RnM d (Either Message (Module, ParsedIface))
976 -- Nothing <=> file not found, or unreadable, or illegible
977 -- Just x <=> successfully found and parsed
979 findAndReadIface doc_str mod_name hi_boot_file
980 = traceRn trace_msg `thenRn_`
981 -- we keep two maps for interface files,
982 -- one for 'normal' ones, the other for .hi-boot files,
983 -- hence the need to signal which kind we're interested.
985 getFinderRn `thenRn` \ finder ->
986 ioToRnM (finder mod_name) `thenRn` \ maybe_found ->
989 Right (Just (mod,locn))
990 | hi_boot_file -> readIface mod (hi_file locn ++ "-hi-boot")
991 | otherwise -> readIface mod (hi_file locn)
994 other -> traceRn (ptext SLIT("...not found")) `thenRn_`
995 returnRn (Left (noIfaceErr mod_name hi_boot_file))
998 trace_msg = sep [hsep [ptext SLIT("Reading"),
999 if hi_boot_file then ptext SLIT("[boot]") else empty,
1000 ptext SLIT("interface for"),
1001 ppr mod_name <> semi],
1002 nest 4 (ptext SLIT("reason:") <+> doc_str)]
1005 @readIface@ tries just the one file.
1008 readIface :: Module -> String -> RnM d (Either Message (Module, ParsedIface))
1009 -- Nothing <=> file not found, or unreadable, or illegible
1010 -- Just x <=> successfully found and parsed
1011 readIface wanted_mod file_path
1012 = traceRn (ptext SLIT("...reading from") <+> text file_path) `thenRn_`
1013 ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
1016 case parseIface contents
1017 PState{ bol = 0#, atbol = 1#,
1020 loc = mkSrcLoc (mkFastString file_path) 1 } of
1021 POk _ (PIface iface) ->
1022 warnCheckRn (wanted_mod == read_mod)
1023 (hiModuleNameMismatchWarn wanted_mod read_mod) `thenRn_`
1024 returnRn (Right (wanted_mod, iface))
1026 read_mod = pi_mod iface
1028 PFailed err -> bale_out err
1029 parse_result -> bale_out empty
1030 -- This last case can happen if the interface file is (say) empty
1031 -- in which case the parser thinks it looks like an IdInfo or
1032 -- something like that. Just an artefact of the fact that the
1033 -- parser is used for several purposes at once.
1035 Left io_err -> bale_out (text (show io_err))
1037 bale_out err = returnRn (Left (badIfaceFile file_path err))
1040 %*********************************************************
1044 %*********************************************************
1047 noIfaceErr mod_name boot_file
1048 = ptext SLIT("Could not find interface file for") <+> quotes (ppr mod_name)
1049 -- We used to print the search path, but we can't do that
1050 -- now, becuase it's hidden inside the finder.
1051 -- Maybe the finder should expose more functions.
1053 badIfaceFile file err
1054 = vcat [ptext SLIT("Bad interface file:") <+> text file,
1058 = vcat [ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name),
1059 ptext SLIT("from module") <+> quotes (ppr (nameModule name))
1064 "Compiler tried to import decl from interface file with same name as module."),
1066 "(possible cause: module name clashes with interface file already in scope.)")
1068 hsep [ptext SLIT("name:"), quotes (ppr name)]
1070 warnRedundantSourceImport mod_name
1071 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
1072 <+> quotes (ppr mod_name)
1074 hiModuleNameMismatchWarn :: Module -> Module -> Message
1075 hiModuleNameMismatchWarn requested_mod read_mod =
1076 hsep [ ptext SLIT("Something is amiss; requested module name")
1077 , ppr (moduleName requested_mod)
1078 , ptext SLIT("differs from name found in the interface file")