2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[RnIfaces]{Cacheing and Renaming of Interfaces}
10 getInterfaceExports, getDeferredDecls,
11 getImportedInstDecls, getImportedRules,
12 lookupFixityRn, loadHomeInterface,
13 importDecl, ImportDeclResult(..), recordLocalSlurps, loadBuiltinRules,
14 mkImportExportInfo, getSlurped,
16 checkModUsage, outOfDate, upToDate,
18 getDeclBinders, getDeclSysBinders,
19 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 ( ieNames )
32 import CoreSyn ( CoreRule )
33 import BasicTypes ( Version, NewOrData(..) )
34 import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameRuleDecl,
35 RdrNameDeprecation, RdrNameIE,
40 import ParseIface ( parseIface, IfaceStuff(..) )
42 import Name ( Name {-instance NamedThing-}, nameOccName,
43 nameModule, isLocallyDefined,
44 isWiredInName, nameUnique, NamedThing(..),
45 elemNameEnv, extendNameEnv
47 import Module ( Module, moduleString, pprModule,
48 mkVanillaModule, pprModuleName,
49 moduleUserString, moduleName, isLocalModule,
50 ModuleName, WhereFrom(..),
52 import RdrName ( RdrName, rdrNameOcc )
54 import SrcLoc ( mkSrcLoc, SrcLoc )
55 import PrelInfo ( cCallishTyKeys )
56 import Maybes ( MaybeErr(..), maybeToBool, orElse )
57 import Unique ( Uniquable(..) )
58 import StringBuffer ( hGetStringBuffer )
59 import FastString ( mkFastString )
60 import ErrUtils ( Message )
61 import Util ( sortLt )
71 %*********************************************************
73 \subsection{Loading a new interface file}
75 %*********************************************************
78 loadHomeInterface :: SDoc -> Name -> RnM d Ifaces
79 loadHomeInterface doc_str name
80 = loadInterface doc_str (moduleName (nameModule name)) ImportBySystem
82 loadOrphanModules :: [ModuleName] -> RnM d ()
83 loadOrphanModules mods
84 | null mods = returnRn ()
85 | otherwise = traceRn (text "Loading orphan modules:" <+>
86 fsep (map pprModuleName mods)) `thenRn_`
87 mapRn_ load mods `thenRn_`
90 load mod = loadInterface (mk_doc mod) mod ImportBySystem
91 mk_doc mod = pprModuleName mod <+> ptext SLIT("is a orphan-instance module")
94 loadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d Ifaces
95 loadInterface doc mod from
96 = tryLoadInterface doc mod from `thenRn` \ (ifaces, maybe_err) ->
98 Nothing -> returnRn ifaces
99 Just err -> failWithRn ifaces err
101 tryLoadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d (Ifaces, Maybe Message)
102 -- Returns (Just err) if an error happened
103 -- Guarantees to return with iImpModInfo m --> (... Just cts)
104 -- (If the load fails, we plug in a vanilla placeholder
105 tryLoadInterface doc_str mod_name from
106 = getIfacesRn `thenRn` \ ifaces ->
108 mod_map = iImpModInfo ifaces
109 mod_info = lookupFM mod_map mod_name
111 hi_boot_file = case from of {
112 ImportByUser -> False ; -- Not hi-boot
113 ImportByUserSource -> True ; -- hi-boot
116 Just (_, is_boot, _) -> is_boot
119 -- We're importing a module we know absolutely
120 -- nothing about, so we assume it's from
121 -- another package, where we aren't doing
122 -- dependency tracking. So it won't be a hi-boot file.
124 redundant_source_import
125 = case (from, mod_info) of
126 (ImportByUserSource, Just (_,False,_)) -> True
129 -- CHECK WHETHER WE HAVE IT ALREADY
132 -> -- We're read it already so don't re-read it
133 returnRn (ifaces, Nothing) ;
137 -- Issue a warning for a redundant {- SOURCE -} import
138 -- NB that we arrange to read all the ordinary imports before
139 -- any of the {- SOURCE -} imports
140 warnCheckRn (not redundant_source_import)
141 (warnRedundantSourceImport mod_name) `thenRn_`
143 -- READ THE MODULE IN
144 findAndReadIface doc_str mod_name hi_boot_file `thenRn` \ read_result ->
145 case read_result of {
146 Left err -> -- Not found, so add an empty export env to the Ifaces map
147 -- so that we don't look again
149 mod = mkVanillaModule mod_name
150 new_mod_map = addToFM mod_map mod_name (False, False, Just (mod, 0, 0, 0, from, []))
151 new_ifaces = ifaces { iImpModInfo = new_mod_map }
153 setIfacesRn new_ifaces `thenRn_`
154 returnRn (new_ifaces, Just err) ;
159 -- LOAD IT INTO Ifaces
161 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
162 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
163 -- If we do loadExport first the wrong info gets into the cache (unless we
164 -- explicitly tag each export which seems a bit of a bore)
166 getModuleRn `thenRn` \ this_mod_nm ->
170 -- Sanity check. If we're system-importing a module we know nothing at all
171 -- about, it should be from a different package to this one
172 WARN( not (maybeToBool mod_info) &&
173 case from of { ImportBySystem -> True; other -> False } &&
176 foldlRn (loadDecl mod) (iDecls ifaces) (pi_decls iface) `thenRn` \ new_decls ->
177 foldlRn (loadInstDecl mod) (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
178 loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ new_rules ->
179 loadFixDecls mod_name (iFixes ifaces) (pi_fixity iface) `thenRn` \ new_fixities ->
180 foldlRn (loadDeprec mod) (iDeprecs ifaces) (pi_deprecs iface) `thenRn` \ new_deprecs ->
181 mapRn (loadExport this_mod_nm) (pi_exports iface) `thenRn` \ avails_s ->
183 -- For an explicit user import, add to mod_map info about
184 -- the things the imported module depends on, extracted
185 -- from its usage info.
186 mod_map1 = case from of
187 ImportByUser -> addModDeps mod (pi_usages iface) mod_map
190 -- Now add info about this module
191 mod_map2 = addToFM mod_map1 mod_name mod_details
192 cts = (pi_mod iface, pi_vers iface,
193 fst (pi_fixity iface), fst (pi_rules iface),
194 from, concat avails_s)
195 mod_details = (pi_orphan iface, hi_boot_file, Just cts)
197 new_ifaces = ifaces { iImpModInfo = mod_map2,
199 iFixes = new_fixities,
202 iDeprecs = new_deprecs }
204 setIfacesRn new_ifaces `thenRn_`
205 returnRn (new_ifaces, Nothing)
208 -----------------------------------------------------
209 -- Adding module dependencies from the
210 -- import decls in the interface file
211 -----------------------------------------------------
213 addModDeps :: Module -> [ImportVersion a]
214 -> ImportedModuleInfo -> ImportedModuleInfo
215 -- (addModDeps M ivs deps)
216 -- We are importing module M, and M.hi contains 'import' decls given by ivs
217 addModDeps mod new_deps mod_deps
218 = foldr add mod_deps filtered_new_deps
220 -- Don't record dependencies when importing a module from another package
221 -- Except for its descendents which contain orphans,
222 -- and in that case, forget about the boot indicator
224 | isLocalModule mod = [ (imp_mod, (has_orphans, is_boot, Nothing))
225 | (imp_mod, has_orphans, is_boot, _) <- new_deps
227 | otherwise = [ (imp_mod, (True, False, Nothing))
228 | (imp_mod, has_orphans, _, _) <- new_deps,
231 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
233 combine old@(_, old_is_boot, cts) new
234 | maybeToBool cts || not old_is_boot = old -- Keep the old info if it's already loaded
235 -- or if it's a non-boot pending load
236 | otherwise = new -- Otherwise pick new info
239 -----------------------------------------------------
240 -- Loading the export list
241 -----------------------------------------------------
243 loadExport :: ModuleName -> ExportItem -> RnM d [AvailInfo]
244 loadExport this_mod (mod, entities)
245 | mod == this_mod = returnRn []
246 -- If the module exports anything defined in this module, just ignore it.
247 -- Reason: otherwise it looks as if there are two local definition sites
248 -- for the thing, and an error gets reported. Easiest thing is just to
249 -- filter them out up front. This situation only arises if a module
250 -- imports itself, or another module that imported it. (Necessarily,
251 -- this invoves a loop.) Consequence: if you say
256 -- module B( AType ) where
257 -- import {-# SOURCE #-} A( AType )
259 -- then you'll get a 'B does not export AType' message. A bit bogus
260 -- but it's a bogus thing to do!
263 = mapRn (load_entity mod) entities
265 new_name mod occ = mkImportedGlobalName mod occ
267 load_entity mod (Avail occ)
268 = new_name mod occ `thenRn` \ name ->
269 returnRn (Avail name)
270 load_entity mod (AvailTC occ occs)
271 = new_name mod occ `thenRn` \ name ->
272 mapRn (new_name mod) occs `thenRn` \ names ->
273 returnRn (AvailTC name names)
276 -----------------------------------------------------
277 -- Loading type/class/value decls
278 -----------------------------------------------------
282 -> (Version, RdrNameHsDecl)
285 loadDecl mod decls_map (version, decl)
286 = getDeclBinders new_name decl `thenRn` \ maybe_avail ->
287 case maybe_avail of {
288 Nothing -> returnRn decls_map; -- No bindings
291 getDeclSysBinders new_name decl `thenRn` \ sys_bndrs ->
293 full_avail = addSysAvails avail sys_bndrs
294 -- Add the sys-binders to avail. When we import the decl,
295 -- it's full_avail that will get added to the 'already-slurped' set (iSlurp)
296 -- If we miss out sys-binders, we'll read the decl multiple times!
298 main_name = availName avail
299 new_decls_map = foldl add_decl decls_map
300 [ (name, (version, full_avail, name==main_name, (mod, decl')))
301 | name <- availNames full_avail]
302 add_decl decls_map (name, stuff)
303 = WARN( name `elemNameEnv` decls_map, ppr name )
304 extendNameEnv decls_map name stuff
306 returnRn new_decls_map
309 -- newTopBinder puts into the cache the binder with the
310 -- module information set correctly. When the decl is later renamed,
311 -- the binding site will thereby get the correct module.
312 -- There maybe occurrences that don't have the correct Module, but
313 -- by the typechecker will propagate the binding definition to all
314 -- the occurrences, so that doesn't matter
315 new_name rdr_name loc = newTopBinder mod (rdrNameOcc rdr_name)
318 If a signature decl is being loaded, and optIgnoreIfacePragmas is on,
319 we toss away unfolding information.
321 Also, if the signature is loaded from a module we're importing from source,
322 we do the same. This is to avoid situations when compiling a pair of mutually
323 recursive modules, peering at unfolding info in the interface file of the other,
324 e.g., you compile A, it looks at B's interface file and may as a result change
325 its interface file. Hence, B is recompiled, maybe changing its interface file,
326 which will the unfolding info used in A to become invalid. Simple way out is to
327 just ignore unfolding info.
329 [Jan 99: I junked the second test above. If we're importing from an hi-boot
330 file there isn't going to *be* any pragma info. Maybe the above comment
331 dates from a time where we picked up a .hi file first if it existed?]
334 SigD (IfaceSig name tp ls loc) | opt_IgnoreIfacePragmas
335 -> SigD (IfaceSig name tp [] loc)
338 -----------------------------------------------------
339 -- Loading fixity decls
340 -----------------------------------------------------
342 loadFixDecls mod_name fixity_env (version, decls)
343 | null decls = returnRn fixity_env
346 = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
347 returnRn (extendNameEnvList fixity_env to_add)
349 loadFixDecl mod_name sig@(FixitySig rdr_name fixity loc)
350 = mkImportedGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
351 returnRn (name, FixitySig name fixity loc)
354 -----------------------------------------------------
355 -- Loading instance decls
356 -----------------------------------------------------
358 loadInstDecl :: Module
362 loadInstDecl mod insts decl@(InstDecl inst_ty binds uprags dfun_name src_loc)
364 -- Find out what type constructors and classes are "gates" for the
365 -- instance declaration. If all these "gates" are slurped in then
366 -- we should slurp the instance decl too.
368 -- We *don't* want to count names in the context part as gates, though.
370 -- instance Foo a => Baz (T a) where ...
372 -- Here the gates are Baz and T, but *not* Foo.
374 munged_inst_ty = removeContext inst_ty
375 free_names = extractHsTyRdrNames munged_inst_ty
377 setModuleRn (moduleName mod) $
378 mapRn mkImportedGlobalFromRdrName free_names `thenRn` \ gate_names ->
379 returnRn ((mkNameSet gate_names, (mod, InstD decl)) `consBag` insts)
382 -- In interface files, the instance decls now look like
383 -- forall a. Foo a -> Baz (T a)
384 -- so we have to strip off function argument types as well
385 -- as the bit before the '=>' (which is always empty in interface files)
386 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
387 removeContext ty = removeFuns ty
389 removeFuns (HsFunTy _ ty) = removeFuns ty
393 -----------------------------------------------------
395 -----------------------------------------------------
397 loadRules :: Module -> IfaceRules
398 -> (Version, [RdrNameRuleDecl])
400 loadRules mod rule_bag (version, rules)
401 | null rules || opt_IgnoreIfacePragmas
404 = setModuleRn mod_name $
405 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
406 returnRn (rule_bag `unionBags` listToBag new_rules)
408 mod_name = moduleName mod
410 loadRule :: Module -> RdrNameRuleDecl -> RnM d GatedDecl
411 -- "Gate" the rule simply by whether the rule variable is
412 -- needed. We can refine this later.
413 loadRule mod decl@(IfaceRule _ _ var _ _ src_loc)
414 = mkImportedGlobalFromRdrName var `thenRn` \ var_name ->
415 returnRn (unitNameSet var_name, (mod, RuleD decl))
417 loadBuiltinRules :: [(RdrName, CoreRule)] -> RnMG ()
418 loadBuiltinRules builtin_rules
419 = getIfacesRn `thenRn` \ ifaces ->
420 mapRn loadBuiltinRule builtin_rules `thenRn` \ rule_decls ->
421 setIfacesRn (ifaces { iRules = iRules ifaces `unionBags` listToBag rule_decls })
423 loadBuiltinRule (var, rule)
424 = mkImportedGlobalFromRdrName var `thenRn` \ var_name ->
425 returnRn (unitNameSet var_name, (nameModule var_name, RuleD (IfaceRuleOut var rule)))
428 -----------------------------------------------------
429 -- Loading Deprecations
430 -----------------------------------------------------
432 loadDeprec :: Module -> DeprecationEnv -> RdrNameDeprecation -> RnM d DeprecationEnv
433 loadDeprec mod deprec_env (Deprecation (IEModuleContents _) txt _)
434 = traceRn (text "module deprecation not yet implemented:" <+> ppr mod <> colon <+> ppr txt) `thenRn_`
435 -- SUP: TEMPORARY HACK, ignoring module deprecations for now
438 loadDeprec mod deprec_env (Deprecation ie txt _)
439 = setModuleRn (moduleName mod) $
440 mapRn mkImportedGlobalFromRdrName (ieNames ie) `thenRn` \ names ->
441 traceRn (text "loaded deprecation(s) for" <+> hcat (punctuate comma (map ppr names)) <> colon <+> ppr txt) `thenRn_`
442 returnRn (extendNameEnvList deprec_env (zip names (repeat txt)))
446 %********************************************************
448 \subsection{Checking usage information}
450 %********************************************************
456 checkModUsage :: [ImportVersion OccName] -> RnMG Bool
457 -- Given the usage information extracted from the old
458 -- M.hi file for the module being compiled, figure out
459 -- whether M needs to be recompiled.
461 checkModUsage [] = returnRn upToDate -- Yes! Everything is up to date!
463 checkModUsage ((mod_name, _, _, NothingAtAll) : rest)
464 -- If CurrentModule.hi contains
466 -- then that simply records that Foo lies below CurrentModule in the
467 -- hierarchy, but CurrentModule doesn't depend in any way on Foo.
468 -- In this case we don't even want to open Foo's interface.
469 = traceRn (ptext SLIT("Nothing used from:") <+> ppr mod_name) `thenRn_`
470 checkModUsage rest -- This one's ok, so check the rest
472 checkModUsage ((mod_name, _, _, whats_imported) : rest)
473 = tryLoadInterface doc_str mod_name ImportBySystem `thenRn` \ (ifaces, maybe_err) ->
475 Just err -> out_of_date (sep [ptext SLIT("Can't find version number for module"),
476 pprModuleName mod_name]) ;
477 -- Couldn't find or parse a module mentioned in the
478 -- old interface file. Don't complain -- it might just be that
479 -- the current module doesn't need that import and it's been deleted
483 (_, new_mod_vers, new_fix_vers, new_rule_vers, _, _)
484 = case lookupFM (iImpModInfo ifaces) mod_name of
485 Just (_, _, Just stuff) -> stuff
487 old_mod_vers = case whats_imported of
489 Specifically v _ _ _ -> v
490 -- NothingAtAll case dealt with by previous eqn for checkModUsage
492 -- If the module version hasn't changed, just move on
493 if new_mod_vers == old_mod_vers then
494 traceRn (sep [ptext SLIT("Module version unchanged:"), pprModuleName mod_name])
495 `thenRn_` checkModUsage rest
497 traceRn (sep [ptext SLIT("Module version has changed:"), pprModuleName mod_name])
499 -- Module version changed, so check entities inside
501 -- If the usage info wants to say "I imported everything from this module"
502 -- it does so by making whats_imported equal to Everything
503 -- In that case, we must recompile
504 case whats_imported of { -- NothingAtAll dealt with earlier
507 -> out_of_date (ptext SLIT("...and I needed the whole module")) ;
509 Specifically _ old_fix_vers old_rule_vers old_local_vers ->
511 if old_fix_vers /= new_fix_vers then
512 out_of_date (ptext SLIT("Fixities changed"))
513 else if old_rule_vers /= new_rule_vers then
514 out_of_date (ptext SLIT("Rules changed"))
516 -- Non-empty usage list, so check item by item
517 checkEntityUsage mod_name (iDecls ifaces) old_local_vers `thenRn` \ up_to_date ->
519 traceRn (ptext SLIT("...but the bits I use haven't.")) `thenRn_`
520 checkModUsage rest -- This one's ok, so check the rest
522 returnRn outOfDate -- This one failed, so just bail out now
525 doc_str = sep [ptext SLIT("need version info for"), pprModuleName mod_name]
528 checkEntityUsage mod decls []
529 = returnRn upToDate -- Yes! All up to date!
531 checkEntityUsage mod decls ((occ_name,old_vers) : rest)
532 = mkImportedGlobalName mod occ_name `thenRn` \ name ->
533 case lookupNameEnv decls name of
535 Nothing -> -- We used it before, but it ain't there now
536 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
538 Just (new_vers,_,_,_) -- It's there, but is it up to date?
539 | new_vers == old_vers
540 -- Up to date, so check the rest
541 -> checkEntityUsage mod decls rest
544 -- Out of date, so bale out
545 -> out_of_date (sep [ptext SLIT("Out of date:"), ppr name])
547 out_of_date msg = traceRn msg `thenRn_` returnRn outOfDate
551 %*********************************************************
553 \subsection{Getting in a declaration}
555 %*********************************************************
558 importDecl :: Name -> RnMG ImportDeclResult
560 data ImportDeclResult
564 | HereItIs (Module, RdrNameHsDecl)
567 = getSlurped `thenRn` \ already_slurped ->
568 if name `elemNameSet` already_slurped then
569 returnRn AlreadySlurped -- Already dealt with
571 else if isLocallyDefined name then -- Don't bring in decls from
572 -- the renamed module's own interface file
573 addWarnRn (importDeclWarn name) `thenRn_`
574 returnRn AlreadySlurped
576 else if isWiredInName name then
577 -- When we find a wired-in name we must load its
578 -- home module so that we find any instance decls therein
579 loadHomeInterface doc name `thenRn_`
582 else getNonWiredInDecl name
584 doc = ptext SLIT("need home module for wired in thing") <+> ppr name
587 {- I don't think this is necessary any more; SLPJ May 00
589 | name `elemNameSet` source_binders = returnRn ()
590 -- When compiling the prelude, a wired-in thing may
591 -- be defined in this module, in which case we don't
592 -- want to load its home module!
593 -- Using 'isLocallyDefined' doesn't work because some of
594 -- the free variables returned are simply 'listTyCon_Name',
595 -- with a system provenance. We could look them up every time
596 -- but that seems a waste.
597 | otherwise = loadHomeInterface doc name `thenRn_`
601 getNonWiredInDecl :: Name -> RnMG ImportDeclResult
602 getNonWiredInDecl needed_name
603 = traceRn doc_str `thenRn_`
604 loadHomeInterface doc_str needed_name `thenRn` \ ifaces ->
605 case lookupNameEnv (iDecls ifaces) needed_name of
607 Just (version, avail, is_tycon_name, decl@(_, TyClD (TyData DataType _ _ _ _ ncons _ _ _)))
608 -- This case deals with deferred import of algebraic data types
610 | not opt_NoPruneTyDecls
612 && (opt_IgnoreIfacePragmas || ncons > 1)
613 -- We only defer if imported interface pragmas are ingored
614 -- or if it's not a product type.
615 -- Sole reason: The wrapper for a strict function may need to look
616 -- inside its arg, and hence need to see its arg type's constructors.
618 && not (getUnique tycon_name `elem` cCallishTyKeys)
619 -- Never defer ccall types; we have to unbox them,
620 -- and importing them does no harm
622 -> -- OK, so we're importing a deferrable data type
623 if needed_name == tycon_name then
624 -- The needed_name is the TyCon of a data type decl
625 -- Record that it's slurped, put it in the deferred set
626 -- and don't return a declaration at all
627 setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces
628 `addOneToNameSet` tycon_name})
629 version (AvailTC needed_name [needed_name])) `thenRn_`
632 -- The needed name is a constructor of a data type decl,
633 -- getting a constructor, so remove the TyCon from the deferred set
634 -- (if it's there) and return the full declaration
635 setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces
636 `delFromNameSet` tycon_name})
637 version avail) `thenRn_`
638 returnRn (HereItIs decl)
640 tycon_name = availName avail
642 Just (version,avail,_,decl)
643 -> setIfacesRn (recordSlurp ifaces version avail) `thenRn_`
644 returnRn (HereItIs decl)
647 -> addErrRn (getDeclErr needed_name) `thenRn_`
648 returnRn AlreadySlurped
650 doc_str = ptext SLIT("need decl for") <+> ppr needed_name
652 getDeferredDecls :: RnMG [(Module, RdrNameHsDecl)]
654 = getIfacesRn `thenRn` \ ifaces ->
656 decls_map = iDecls ifaces
657 deferred_names = nameSetToList (iDeferred ifaces)
658 get_abstract_decl n = case lookupNameEnv decls_map n of
659 Just (_, _, _, decl) -> decl
661 traceRn (sep [text "getDeferredDecls", nest 4 (fsep (map ppr deferred_names))]) `thenRn_`
662 returnRn (map get_abstract_decl deferred_names)
665 @getWiredInDecl@ maps a wired-in @Name@ to what it makes available.
666 It behaves exactly as if the wired in decl were actually in an interface file.
669 \item if the wired-in name is a data type constructor or a data constructor,
670 it brings in the type constructor and all the data constructors; and
671 marks as ``occurrences'' any free vars of the data con.
673 \item similarly for synonum type constructor
675 \item if the wired-in name is another wired-in Id, it marks as ``occurrences''
676 the free vars of the Id's type.
678 \item it loads the interface file for the wired-in thing for the
679 sole purpose of making sure that its instance declarations are available
681 All this is necessary so that we know all types that are ``in play'', so
682 that we know just what instances to bring into scope.
687 %*********************************************************
689 \subsection{Getting what a module exports}
691 %*********************************************************
693 @getInterfaceExports@ is called only for directly-imported modules.
696 getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, Avails)
697 getInterfaceExports mod_name from
698 = loadInterface doc_str mod_name from `thenRn` \ ifaces ->
699 case lookupFM (iImpModInfo ifaces) mod_name of
700 Just (_, _, Just (mod, _, _, _, _, avails)) -> returnRn (mod, avails)
701 -- loadInterface always puts something in the map
702 -- even if it's a fake
704 doc_str = sep [pprModuleName mod_name, ptext SLIT("is directly imported")]
708 %*********************************************************
710 \subsection{Instance declarations are handled specially}
712 %*********************************************************
715 getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)]
716 getImportedInstDecls gates
717 = -- First, load any orphan-instance modules that aren't aready loaded
718 -- Orphan-instance modules are recorded in the module dependecnies
719 getIfacesRn `thenRn` \ ifaces ->
722 [mod | (mod, (True, _, Nothing)) <- fmToList (iImpModInfo ifaces)]
724 loadOrphanModules orphan_mods `thenRn_`
726 -- Now we're ready to grab the instance declarations
727 -- Find the un-gated ones and return them,
728 -- removing them from the bag kept in Ifaces
729 getIfacesRn `thenRn` \ ifaces ->
731 (decls, new_insts) = selectGated gates (iInsts ifaces)
733 setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_`
735 traceRn (sep [text "getImportedInstDecls:",
736 nest 4 (fsep (map ppr gate_list)),
737 text "Slurped" <+> int (length decls) <+> text "instance declarations",
738 nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_`
741 gate_list = nameSetToList gates
743 ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _))
745 HsForAllTy _ _ tau -> ppr tau
748 getImportedRules :: RnMG [(Module,RdrNameHsDecl)]
750 | opt_IgnoreIfacePragmas = returnRn []
752 = getIfacesRn `thenRn` \ ifaces ->
754 gates = iSlurp ifaces -- Anything at all that's been slurped
755 rules = iRules ifaces
756 (decls, new_rules) = selectGated gates rules
761 setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
762 traceRn (sep [text "getImportedRules:",
763 text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
766 selectGated gates decl_bag
767 -- Select only those decls whose gates are *all* in 'gates'
769 | opt_NoPruneDecls -- Just to try the effect of not gating at all
770 = (foldrBag (\ (_,d) ds -> d:ds) [] decl_bag, emptyBag) -- Grab them all
774 = foldrBag select ([], emptyBag) decl_bag
776 select (reqd, decl) (yes, no)
777 | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no)
778 | otherwise = (yes, (reqd,decl) `consBag` no)
780 lookupFixityRn :: Name -> RnMS Fixity
782 | isLocallyDefined name
783 = getFixityEnv `thenRn` \ local_fix_env ->
784 returnRn (lookupFixity local_fix_env name)
786 | otherwise -- Imported
787 -- For imported names, we have to get their fixities by doing a loadHomeInterface,
788 -- and consulting the Ifaces that comes back from that, because the interface
789 -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
790 -- which exports a function 'f', which is defined in module B. Then B isn't loaded
791 -- right away (after all, it's possible that nothing from B will be used).
792 -- When we come across a use of 'f', we need to know its fixity, and it's then,
793 -- and only then, that we load B.hi. That is what's happening here.
794 = loadHomeInterface doc name `thenRn` \ ifaces ->
795 returnRn (lookupFixity (iFixes ifaces) name)
797 doc = ptext SLIT("Checking fixity for") <+> ppr name
801 %*********************************************************
803 \subsection{Keeping track of what we've slurped, and version numbers}
805 %*********************************************************
807 getImportVersions figures out what the ``usage information'' for this
808 moudule is; that is, what it must record in its interface file as the
809 things it uses. It records:
812 \item (a) anything reachable from its body code
813 \item (b) any module exported with a @module Foo@
814 \item (c) anything reachable from an exported item
817 Why (b)? Because if @Foo@ changes then this module's export list
818 will change, so we must recompile this module at least as far as
819 making a new interface file --- but in practice that means complete
822 Why (c)? Consider this:
824 module A( f, g ) where | module B( f ) where
825 import B( f ) | f = h 3
829 Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
830 @A@'s usages? Our idea is that we aren't going to touch A.hi if it is
831 *identical* to what it was before. If anything about @B.f@ changes
832 than anyone who imports @A@ should be recompiled in case they use
833 @B.f@ (they'll get an early exit if they don't). So, if anything
834 about @B.f@ changes we'd better make sure that something in A.hi
835 changes, and the convenient way to do that is to record the version
836 number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
837 complete recompiation of A, which is overkill but it's the only way to
838 write a new, slightly different, A.hi.
840 But the example is tricker. Even if @B.f@ doesn't change at all,
841 @B.h@ may do so, and this change may not be reflected in @f@'s version
842 number. But with -O, a module that imports A must be recompiled if
843 @B.h@ changes! So A must record a dependency on @B.h@. So we treat
844 the occurrence of @B.f@ in the export list *just as if* it were in the
845 code of A, and thereby haul in all the stuff reachable from it.
847 [NB: If B was compiled with -O, but A isn't, we should really *still*
848 haul in all the unfoldings for B, in case the module that imports A *is*
849 compiled with -O. I think this is the case.]
851 Even if B is used at all we get a usage line for B
852 import B <n> :: ... ;
853 in A.hi, to record the fact that A does import B. This is used to decide
854 to look to look for B.hi rather than B.hi-boot when compiling a module that
855 imports A. This line says that A imports B, but uses nothing in it.
856 So we'll get an early bale-out when compiling A if B's version changes.
859 mkImportExportInfo :: ModuleName -- Name of this module
860 -> Avails -- Info about exports
861 -> Maybe [RdrNameIE] -- The export header
862 -> RnMG ([ExportItem], -- Export info for iface file; sorted
863 [ImportVersion OccName]) -- Import info for iface file; sorted
864 -- Both results are sorted into canonical order to
865 -- reduce needless wobbling of interface files
867 mkImportExportInfo this_mod export_avails exports
868 = getIfacesRn `thenRn` \ ifaces ->
870 export_all_mods = case exports of
872 Just es -> [mod | IEModuleContents mod <- es,
875 mod_map = iImpModInfo ifaces
876 imp_names = iVSlurp ifaces
878 -- mv_map groups together all the things imported from a particular module.
879 mv_map :: FiniteMap ModuleName [(OccName,Version)]
880 mv_map = foldr add_mv emptyFM imp_names
882 add_mv (name, version) mv_map = addItem mv_map (moduleName (nameModule name))
883 (nameOccName name, version)
885 -- Build the result list by adding info for each module.
886 -- For (a) a library module, we don't record it at all unless it contains orphans
887 -- (We must never lose track of orphans.)
889 -- (b) a source-imported module, don't record the dependency at all
891 -- (b) may seem a bit strange. The idea is that the usages in a .hi file records
892 -- *all* the module's dependencies other than the loop-breakers. We use
893 -- this info in findAndReadInterface to decide whether to look for a .hi file or
896 -- This means we won't track version changes, or orphans, from .hi-boot files.
897 -- The former is potentially rather bad news. It could be fixed by recording
898 -- whether something is a boot file along with the usage info for it, but
899 -- I can't be bothered just now.
901 mk_imp_info mod_name (has_orphans, is_boot, contents) so_far
902 | mod_name == this_mod -- Check if M appears in the set of modules 'below' M
903 -- This seems like a convenient place to check
904 = WARN( not is_boot, ptext SLIT("Wierd:") <+> ppr this_mod <+>
905 ptext SLIT("imports itself (perhaps indirectly)") )
910 go_for_it exports = (mod_name, has_orphans, is_boot, exports)
914 Nothing -> -- We didn't even open the interface
915 -- This happens when a module, Foo, that we explicitly imported has
916 -- 'import Baz' in its interface file, recording that Baz is below
917 -- Foo in the module dependency hierarchy. We want to propagate this
918 -- information. The Nothing says that we didn't even open the interface
919 -- file but we must still propagate the dependeny info.
920 -- The module in question must be a local module (in the same package)
921 go_for_it NothingAtAll
923 Just (mod, mod_vers, fix_vers, rule_vers, how_imported, _)
924 | is_sys_import && is_lib_module && not has_orphans
927 | is_lib_module -- Record the module but not detailed
928 || mod_name `elem` export_all_mods -- version information for the imports
929 -> go_for_it (Everything mod_vers)
932 -> case lookupFM mv_map mod_name of
933 Just whats_imported -> go_for_it (Specifically mod_vers fix_vers rule_vers
934 (sortImport whats_imported))
935 Nothing -> go_for_it NothingAtAll
936 -- This happens if you have
938 -- but don't actually *use* anything from Foo
939 -- In which case record an empty dependency list
941 is_lib_module = not (isLocalModule mod)
942 is_sys_import = case how_imported of
943 ImportBySystem -> True
947 import_info = foldFM mk_imp_info [] mod_map
949 -- Sort exports into groups by module
950 export_fm :: FiniteMap ModuleName [RdrAvailInfo]
951 export_fm = foldr insert emptyFM export_avails
953 insert avail efm = addItem efm (moduleName (nameModule (availName avail)))
956 export_info = [(m, sortExport as) | (m,as) <- fmToList export_fm]
958 returnRn (export_info, import_info)
961 addItem :: FiniteMap ModuleName [a] -> ModuleName -> a -> FiniteMap ModuleName [a]
962 addItem fm mod x = addToFM_C add_item fm mod [x]
966 sortImport :: [(OccName,Version)] -> [(OccName,Version)]
967 -- Make the usage lists appear in canonical order
968 sortImport vs = sortLt lt vs
970 lt (n1,v1) (n2,v2) = n1 < n2
972 sortExport :: [RdrAvailInfo] -> [RdrAvailInfo]
973 sortExport as = sortLt lt as
975 lt a1 a2 = availName a1 < availName a2
980 = getIfacesRn `thenRn` \ ifaces ->
981 returnRn (iSlurp ifaces)
983 recordSlurp ifaces@(Ifaces { iSlurp = slurped_names, iVSlurp = imp_names })
986 new_slurped_names = addAvailToNameSet slurped_names avail
987 new_imp_names = (availName avail, version) : imp_names
989 ifaces { iSlurp = new_slurped_names, iVSlurp = new_imp_names }
991 recordLocalSlurps local_avails
992 = getIfacesRn `thenRn` \ ifaces ->
994 new_slurped_names = foldl addAvailToNameSet (iSlurp ifaces) local_avails
996 setIfacesRn (ifaces { iSlurp = new_slurped_names })
1000 %*********************************************************
1002 \subsection{Getting binders out of a declaration}
1004 %*********************************************************
1006 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
1007 It's used for both source code (from @availsFromDecl@) and interface files
1010 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
1011 are handled by the sourc-code specific stuff in @RnNames@.
1014 getDeclBinders :: (RdrName -> SrcLoc -> RnM d Name) -- New-name function
1016 -> RnM d (Maybe AvailInfo)
1018 getDeclBinders new_name (TyClD (TyData _ _ tycon _ condecls _ _ _ src_loc))
1019 = new_name tycon src_loc `thenRn` \ tycon_name ->
1020 getConFieldNames new_name condecls `thenRn` \ sub_names ->
1021 returnRn (Just (AvailTC tycon_name (tycon_name : nub sub_names)))
1022 -- The "nub" is because getConFieldNames can legitimately return duplicates,
1023 -- when a record declaration has the same field in multiple constructors
1025 getDeclBinders new_name (TyClD (TySynonym tycon _ _ src_loc))
1026 = new_name tycon src_loc `thenRn` \ tycon_name ->
1027 returnRn (Just (AvailTC tycon_name [tycon_name]))
1029 getDeclBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ _ _ _ _ src_loc))
1030 = new_name cname src_loc `thenRn` \ class_name ->
1032 -- Record the names for the class ops
1034 -- just want class-op sigs
1035 op_sigs = filter isClassOpSig sigs
1037 mapRn (getClassOpNames new_name) op_sigs `thenRn` \ sub_names ->
1039 returnRn (Just (AvailTC class_name (class_name : sub_names)))
1041 getDeclBinders new_name (SigD (IfaceSig var ty prags src_loc))
1042 = new_name var src_loc `thenRn` \ var_name ->
1043 returnRn (Just (Avail var_name))
1045 getDeclBinders new_name (FixD _) = returnRn Nothing
1046 getDeclBinders new_name (DeprecD _) = returnRn Nothing
1048 -- foreign declarations
1049 getDeclBinders new_name (ForD (ForeignDecl nm kind _ dyn _ loc))
1050 | binds_haskell_name kind dyn
1051 = new_name nm loc `thenRn` \ name ->
1052 returnRn (Just (Avail name))
1054 | otherwise -- a foreign export
1055 = lookupImplicitOccRn nm `thenRn_`
1058 getDeclBinders new_name (DefD _) = returnRn Nothing
1059 getDeclBinders new_name (InstD _) = returnRn Nothing
1060 getDeclBinders new_name (RuleD _) = returnRn Nothing
1062 binds_haskell_name (FoImport _) _ = True
1063 binds_haskell_name FoLabel _ = True
1064 binds_haskell_name FoExport ext_nm = isDynamicExtName ext_nm
1067 getConFieldNames new_name (ConDecl con _ _ _ (RecCon fielddecls) src_loc : rest)
1068 = mapRn (\n -> new_name n src_loc) (con:fields) `thenRn` \ cfs ->
1069 getConFieldNames new_name rest `thenRn` \ ns ->
1070 returnRn (cfs ++ ns)
1072 fields = concat (map fst fielddecls)
1074 getConFieldNames new_name (ConDecl con _ _ _ condecl src_loc : rest)
1075 = new_name con src_loc `thenRn` \ n ->
1077 NewCon _ (Just f) ->
1078 new_name f src_loc `thenRn` \ new_f ->
1080 _ -> returnRn [n]) `thenRn` \ nn ->
1081 getConFieldNames new_name rest `thenRn` \ ns ->
1084 getConFieldNames new_name [] = returnRn []
1086 getClassOpNames new_name (ClassOpSig op _ _ _ src_loc) = new_name op src_loc
1089 @getDeclSysBinders@ gets the implicit binders introduced by a decl.
1090 A the moment that's just the tycon and datacon that come with a class decl.
1091 They aren't returned by @getDeclBinders@ because they aren't in scope;
1092 but they {\em should} be put into the @DeclsMap@ of this module.
1094 Note that this excludes the default-method names of a class decl,
1095 and the dict fun of an instance decl, because both of these have
1096 bindings of their own elsewhere.
1099 getDeclSysBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ tname dname dwname snames src_loc))
1100 = sequenceRn [new_name n src_loc | n <- (tname : dname : dwname : snames)]
1102 getDeclSysBinders new_name (TyClD (TyData _ _ _ _ cons _ _ _ _))
1103 = sequenceRn [new_name wkr_name src_loc | ConDecl _ wkr_name _ _ _ src_loc <- cons]
1105 getDeclSysBinders new_name other_decl
1109 %*********************************************************
1111 \subsection{Reading an interface file}
1113 %*********************************************************
1116 findAndReadIface :: SDoc -> ModuleName
1117 -> IsBootInterface -- True <=> Look for a .hi-boot file
1118 -- False <=> Look for .hi file
1119 -> RnM d (Either Message ParsedIface)
1120 -- Nothing <=> file not found, or unreadable, or illegible
1121 -- Just x <=> successfully found and parsed
1123 findAndReadIface doc_str mod_name hi_boot_file
1124 = traceRn trace_msg `thenRn_`
1125 -- we keep two maps for interface files,
1126 -- one for 'normal' ones, the other for .hi-boot files,
1127 -- hence the need to signal which kind we're interested.
1129 getHiMaps `thenRn` \ (search_path, hi_map, hiboot_map) ->
1131 relevant_map | hi_boot_file = hiboot_map
1132 | otherwise = hi_map
1134 case lookupFM relevant_map mod_name of
1136 Just fpath -> traceRn (ptext SLIT("...reading from") <+> text fpath) `thenRn_`
1137 readIface mod_name fpath
1140 Nothing -> traceRn (ptext SLIT("...not found")) `thenRn_`
1141 returnRn (Left (noIfaceErr mod_name hi_boot_file search_path))
1144 trace_msg = sep [hsep [ptext SLIT("Reading"),
1145 if hi_boot_file then ptext SLIT("[boot]") else empty,
1146 ptext SLIT("interface for"),
1147 pprModuleName mod_name <> semi],
1148 nest 4 (ptext SLIT("reason:") <+> doc_str)]
1151 @readIface@ tries just the one file.
1154 readIface :: ModuleName -> String -> RnM d (Either Message ParsedIface)
1155 -- Nothing <=> file not found, or unreadable, or illegible
1156 -- Just x <=> successfully found and parsed
1157 readIface wanted_mod file_path
1158 = ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
1161 case parseIface contents
1162 PState{ bol = 0#, atbol = 1#,
1165 loc = mkSrcLoc (mkFastString file_path) 1 } of
1166 POk _ (PIface iface) ->
1167 warnCheckRn (read_mod == wanted_mod)
1168 (hiModuleNameMismatchWarn wanted_mod read_mod) `thenRn_`
1169 returnRn (Right iface)
1171 read_mod = moduleName (pi_mod iface)
1173 PFailed err -> bale_out err
1174 parse_result -> bale_out empty
1175 -- This last case can happen if the interface file is (say) empty
1176 -- in which case the parser thinks it looks like an IdInfo or
1177 -- something like that. Just an artefact of the fact that the
1178 -- parser is used for several purposes at once.
1180 Left io_err -> bale_out (text (show io_err))
1182 bale_out err = returnRn (Left (badIfaceFile file_path err))
1185 %*********************************************************
1189 %*********************************************************
1192 noIfaceErr mod_name boot_file search_path
1193 = vcat [ptext SLIT("Could not find interface file for") <+> quotes (pprModuleName mod_name),
1194 ptext SLIT("in the directories") <+>
1195 -- \& to avoid cpp interpreting this string as a
1196 -- comment starter with a pre-4.06 mkdependHS --SDM
1197 vcat [ text dir <> text "/\&*" <> pp_suffix suffix
1198 | (dir,suffix) <- search_path]
1201 pp_suffix suffix | boot_file = ptext SLIT(".hi-boot")
1202 | otherwise = text suffix
1204 badIfaceFile file err
1205 = vcat [ptext SLIT("Bad interface file:") <+> text file,
1209 = vcat [ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name),
1210 ptext SLIT("from module") <+> quotes (ppr (nameModule name))
1213 getDeclWarn name loc
1214 = sep [ptext SLIT("Failed to find (optional) interface decl for") <+> quotes (ppr name),
1215 ptext SLIT("desired at") <+> ppr loc]
1219 "Compiler tried to import decl from interface file with same name as module."),
1221 "(possible cause: module name clashes with interface file already in scope.)")
1223 hsep [ptext SLIT("name:"), quotes (ppr name)]
1225 warnRedundantSourceImport mod_name
1226 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
1227 <+> quotes (pprModuleName mod_name)
1229 hiModuleNameMismatchWarn :: ModuleName -> ModuleName -> Message
1230 hiModuleNameMismatchWarn requested_mod read_mod =
1231 hsep [ ptext SLIT("Something is amiss; requested module name")
1232 , pprModuleName requested_mod
1233 , ptext SLIT("differs from name found in the interface file")
1234 , pprModuleName read_mod