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 ->
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) (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 :: Module -> ExportItem -> RnM d [AvailInfo]
244 loadExport this_mod (mod, entities)
245 | mod == moduleName 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 = newGlobalName 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 = newGlobalName 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
378 mapRn lookupOrigName 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
405 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
406 returnRn (rule_bag `unionBags` listToBag new_rules)
408 loadRule :: Module -> RdrNameRuleDecl -> RnM d GatedDecl
409 -- "Gate" the rule simply by whether the rule variable is
410 -- needed. We can refine this later.
411 loadRule mod decl@(IfaceRule _ _ var _ _ src_loc)
412 = lookupOrigName var `thenRn` \ var_name ->
413 returnRn (unitNameSet var_name, (mod, RuleD decl))
415 loadBuiltinRules :: [(RdrName, CoreRule)] -> RnMG ()
416 loadBuiltinRules builtin_rules
417 = getIfacesRn `thenRn` \ ifaces ->
418 mapRn loadBuiltinRule builtin_rules `thenRn` \ rule_decls ->
419 setIfacesRn (ifaces { iRules = iRules ifaces `unionBags` listToBag rule_decls })
421 loadBuiltinRule (var, rule)
422 = lookupOrigName var `thenRn` \ var_name ->
423 returnRn (unitNameSet var_name, (nameModule var_name, RuleD (IfaceRuleOut var rule)))
426 -----------------------------------------------------
427 -- Loading Deprecations
428 -----------------------------------------------------
430 loadDeprec :: Module -> DeprecationEnv -> RdrNameDeprecation -> RnM d DeprecationEnv
431 loadDeprec mod deprec_env (Deprecation (IEModuleContents _) txt _)
432 = traceRn (text "module deprecation not yet implemented:" <+> ppr mod <> colon <+> ppr txt) `thenRn_`
433 -- SUP: TEMPORARY HACK, ignoring module deprecations for now
436 loadDeprec mod deprec_env (Deprecation ie txt _)
438 mapRn lookupOrigName (ieNames ie) `thenRn` \ names ->
439 traceRn (text "loaded deprecation(s) for" <+> hcat (punctuate comma (map ppr names)) <> colon <+> ppr txt) `thenRn_`
440 returnRn (extendNameEnvList deprec_env (zip names (repeat txt)))
444 %********************************************************
446 \subsection{Checking usage information}
448 %********************************************************
454 checkModUsage :: [ImportVersion OccName] -> RnMG Bool
455 -- Given the usage information extracted from the old
456 -- M.hi file for the module being compiled, figure out
457 -- whether M needs to be recompiled.
459 checkModUsage [] = returnRn upToDate -- Yes! Everything is up to date!
461 checkModUsage ((mod_name, _, _, NothingAtAll) : rest)
462 -- If CurrentModule.hi contains
464 -- then that simply records that Foo lies below CurrentModule in the
465 -- hierarchy, but CurrentModule doesn't depend in any way on Foo.
466 -- In this case we don't even want to open Foo's interface.
467 = traceRn (ptext SLIT("Nothing used from:") <+> ppr mod_name) `thenRn_`
468 checkModUsage rest -- This one's ok, so check the rest
470 checkModUsage ((mod_name, _, _, whats_imported) : rest)
471 = tryLoadInterface doc_str mod_name ImportBySystem `thenRn` \ (ifaces, maybe_err) ->
473 Just err -> out_of_date (sep [ptext SLIT("Can't find version number for module"),
474 pprModuleName mod_name]) ;
475 -- Couldn't find or parse a module mentioned in the
476 -- old interface file. Don't complain -- it might just be that
477 -- the current module doesn't need that import and it's been deleted
481 (_, new_mod_vers, new_fix_vers, new_rule_vers, _, _)
482 = case lookupFM (iImpModInfo ifaces) mod_name of
483 Just (_, _, Just stuff) -> stuff
485 old_mod_vers = case whats_imported of
487 Specifically v _ _ _ -> v
488 -- NothingAtAll case dealt with by previous eqn for checkModUsage
490 -- If the module version hasn't changed, just move on
491 if new_mod_vers == old_mod_vers then
492 traceRn (sep [ptext SLIT("Module version unchanged:"), pprModuleName mod_name])
493 `thenRn_` checkModUsage rest
495 traceRn (sep [ptext SLIT("Module version has changed:"), pprModuleName mod_name])
497 -- Module version changed, so check entities inside
499 -- If the usage info wants to say "I imported everything from this module"
500 -- it does so by making whats_imported equal to Everything
501 -- In that case, we must recompile
502 case whats_imported of { -- NothingAtAll dealt with earlier
505 -> out_of_date (ptext SLIT("...and I needed the whole module")) ;
507 Specifically _ old_fix_vers old_rule_vers old_local_vers ->
509 if old_fix_vers /= new_fix_vers then
510 out_of_date (ptext SLIT("Fixities changed"))
511 else if old_rule_vers /= new_rule_vers then
512 out_of_date (ptext SLIT("Rules changed"))
514 -- Non-empty usage list, so check item by item
515 checkEntityUsage mod_name (iDecls ifaces) old_local_vers `thenRn` \ up_to_date ->
517 traceRn (ptext SLIT("...but the bits I use haven't.")) `thenRn_`
518 checkModUsage rest -- This one's ok, so check the rest
520 returnRn outOfDate -- This one failed, so just bail out now
523 doc_str = sep [ptext SLIT("need version info for"), pprModuleName mod_name]
526 checkEntityUsage mod decls []
527 = returnRn upToDate -- Yes! All up to date!
529 checkEntityUsage mod decls ((occ_name,old_vers) : rest)
530 = newGlobalName mod occ_name `thenRn` \ name ->
531 case lookupNameEnv decls name of
533 Nothing -> -- We used it before, but it ain't there now
534 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
536 Just (new_vers,_,_,_) -- It's there, but is it up to date?
537 | new_vers == old_vers
538 -- Up to date, so check the rest
539 -> checkEntityUsage mod decls rest
542 -- Out of date, so bale out
543 -> out_of_date (sep [ptext SLIT("Out of date:"), ppr name])
545 out_of_date msg = traceRn msg `thenRn_` returnRn outOfDate
549 %*********************************************************
551 \subsection{Getting in a declaration}
553 %*********************************************************
556 importDecl :: Name -> RnMG ImportDeclResult
558 data ImportDeclResult
562 | HereItIs (Module, RdrNameHsDecl)
565 = getSlurped `thenRn` \ already_slurped ->
566 if name `elemNameSet` already_slurped then
567 returnRn AlreadySlurped -- Already dealt with
569 else if isLocallyDefined name then -- Don't bring in decls from
570 -- the renamed module's own interface file
571 addWarnRn (importDeclWarn name) `thenRn_`
572 returnRn AlreadySlurped
574 else if isWiredInName name then
575 -- When we find a wired-in name we must load its
576 -- home module so that we find any instance decls therein
577 loadHomeInterface doc name `thenRn_`
580 else getNonWiredInDecl name
582 doc = ptext SLIT("need home module for wired in thing") <+> ppr name
585 {- I don't think this is necessary any more; SLPJ May 00
587 | name `elemNameSet` source_binders = returnRn ()
588 -- When compiling the prelude, a wired-in thing may
589 -- be defined in this module, in which case we don't
590 -- want to load its home module!
591 -- Using 'isLocallyDefined' doesn't work because some of
592 -- the free variables returned are simply 'listTyCon_Name',
593 -- with a system provenance. We could look them up every time
594 -- but that seems a waste.
595 | otherwise = loadHomeInterface doc name `thenRn_`
599 getNonWiredInDecl :: Name -> RnMG ImportDeclResult
600 getNonWiredInDecl needed_name
601 = traceRn doc_str `thenRn_`
602 loadHomeInterface doc_str needed_name `thenRn` \ ifaces ->
603 case lookupNameEnv (iDecls ifaces) needed_name of
605 Just (version, avail, is_tycon_name, decl@(_, TyClD (TyData DataType _ _ _ _ ncons _ _ _)))
606 -- This case deals with deferred import of algebraic data types
608 | not opt_NoPruneTyDecls
610 && (opt_IgnoreIfacePragmas || ncons > 1)
611 -- We only defer if imported interface pragmas are ingored
612 -- or if it's not a product type.
613 -- Sole reason: The wrapper for a strict function may need to look
614 -- inside its arg, and hence need to see its arg type's constructors.
616 && not (getUnique tycon_name `elem` cCallishTyKeys)
617 -- Never defer ccall types; we have to unbox them,
618 -- and importing them does no harm
620 -> -- OK, so we're importing a deferrable data type
621 if needed_name == tycon_name then
622 -- The needed_name is the TyCon of a data type decl
623 -- Record that it's slurped, put it in the deferred set
624 -- and don't return a declaration at all
625 setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces
626 `addOneToNameSet` tycon_name})
627 version (AvailTC needed_name [needed_name])) `thenRn_`
630 -- The needed name is a constructor of a data type decl,
631 -- getting a constructor, so remove the TyCon from the deferred set
632 -- (if it's there) and return the full declaration
633 setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces
634 `delFromNameSet` tycon_name})
635 version avail) `thenRn_`
636 returnRn (HereItIs decl)
638 tycon_name = availName avail
640 Just (version,avail,_,decl)
641 -> setIfacesRn (recordSlurp ifaces version avail) `thenRn_`
642 returnRn (HereItIs decl)
645 -> addErrRn (getDeclErr needed_name) `thenRn_`
646 returnRn AlreadySlurped
648 doc_str = ptext SLIT("need decl for") <+> ppr needed_name
650 getDeferredDecls :: RnMG [(Module, RdrNameHsDecl)]
652 = getIfacesRn `thenRn` \ ifaces ->
654 decls_map = iDecls ifaces
655 deferred_names = nameSetToList (iDeferred ifaces)
656 get_abstract_decl n = case lookupNameEnv decls_map n of
657 Just (_, _, _, decl) -> decl
659 traceRn (sep [text "getDeferredDecls", nest 4 (fsep (map ppr deferred_names))]) `thenRn_`
660 returnRn (map get_abstract_decl deferred_names)
663 @getWiredInDecl@ maps a wired-in @Name@ to what it makes available.
664 It behaves exactly as if the wired in decl were actually in an interface file.
667 \item if the wired-in name is a data type constructor or a data constructor,
668 it brings in the type constructor and all the data constructors; and
669 marks as ``occurrences'' any free vars of the data con.
671 \item similarly for synonum type constructor
673 \item if the wired-in name is another wired-in Id, it marks as ``occurrences''
674 the free vars of the Id's type.
676 \item it loads the interface file for the wired-in thing for the
677 sole purpose of making sure that its instance declarations are available
679 All this is necessary so that we know all types that are ``in play'', so
680 that we know just what instances to bring into scope.
685 %*********************************************************
687 \subsection{Getting what a module exports}
689 %*********************************************************
691 @getInterfaceExports@ is called only for directly-imported modules.
694 getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, Avails)
695 getInterfaceExports mod_name from
696 = loadInterface doc_str mod_name from `thenRn` \ ifaces ->
697 case lookupFM (iImpModInfo ifaces) mod_name of
698 Just (_, _, Just (mod, _, _, _, _, avails)) -> returnRn (mod, avails)
699 -- loadInterface always puts something in the map
700 -- even if it's a fake
702 doc_str = sep [pprModuleName mod_name, ptext SLIT("is directly imported")]
706 %*********************************************************
708 \subsection{Instance declarations are handled specially}
710 %*********************************************************
713 getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)]
714 getImportedInstDecls gates
715 = -- First, load any orphan-instance modules that aren't aready loaded
716 -- Orphan-instance modules are recorded in the module dependecnies
717 getIfacesRn `thenRn` \ ifaces ->
720 [mod | (mod, (True, _, Nothing)) <- fmToList (iImpModInfo ifaces)]
722 loadOrphanModules orphan_mods `thenRn_`
724 -- Now we're ready to grab the instance declarations
725 -- Find the un-gated ones and return them,
726 -- removing them from the bag kept in Ifaces
727 getIfacesRn `thenRn` \ ifaces ->
729 (decls, new_insts) = selectGated gates (iInsts ifaces)
731 setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_`
733 traceRn (sep [text "getImportedInstDecls:",
734 nest 4 (fsep (map ppr gate_list)),
735 text "Slurped" <+> int (length decls) <+> text "instance declarations",
736 nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_`
739 gate_list = nameSetToList gates
741 ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _))
743 HsForAllTy _ _ tau -> ppr tau
746 getImportedRules :: RnMG [(Module,RdrNameHsDecl)]
748 | opt_IgnoreIfacePragmas = returnRn []
750 = getIfacesRn `thenRn` \ ifaces ->
752 gates = iSlurp ifaces -- Anything at all that's been slurped
753 rules = iRules ifaces
754 (decls, new_rules) = selectGated gates rules
759 setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
760 traceRn (sep [text "getImportedRules:",
761 text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
764 selectGated gates decl_bag
765 -- Select only those decls whose gates are *all* in 'gates'
767 | opt_NoPruneDecls -- Just to try the effect of not gating at all
768 = (foldrBag (\ (_,d) ds -> d:ds) [] decl_bag, emptyBag) -- Grab them all
772 = foldrBag select ([], emptyBag) decl_bag
774 select (reqd, decl) (yes, no)
775 | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no)
776 | otherwise = (yes, (reqd,decl) `consBag` no)
778 lookupFixityRn :: Name -> RnMS Fixity
780 | isLocallyDefined name
781 = getFixityEnv `thenRn` \ local_fix_env ->
782 returnRn (lookupFixity local_fix_env name)
784 | otherwise -- Imported
785 -- For imported names, we have to get their fixities by doing a loadHomeInterface,
786 -- and consulting the Ifaces that comes back from that, because the interface
787 -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
788 -- which exports a function 'f', which is defined in module B. Then B isn't loaded
789 -- right away (after all, it's possible that nothing from B will be used).
790 -- When we come across a use of 'f', we need to know its fixity, and it's then,
791 -- and only then, that we load B.hi. That is what's happening here.
792 = loadHomeInterface doc name `thenRn` \ ifaces ->
793 returnRn (lookupFixity (iFixes ifaces) name)
795 doc = ptext SLIT("Checking fixity for") <+> ppr name
799 %*********************************************************
801 \subsection{Keeping track of what we've slurped, and version numbers}
803 %*********************************************************
805 getImportVersions figures out what the ``usage information'' for this
806 moudule is; that is, what it must record in its interface file as the
807 things it uses. It records:
810 \item (a) anything reachable from its body code
811 \item (b) any module exported with a @module Foo@
812 \item (c) anything reachable from an exported item
815 Why (b)? Because if @Foo@ changes then this module's export list
816 will change, so we must recompile this module at least as far as
817 making a new interface file --- but in practice that means complete
820 Why (c)? Consider this:
822 module A( f, g ) where | module B( f ) where
823 import B( f ) | f = h 3
827 Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
828 @A@'s usages? Our idea is that we aren't going to touch A.hi if it is
829 *identical* to what it was before. If anything about @B.f@ changes
830 than anyone who imports @A@ should be recompiled in case they use
831 @B.f@ (they'll get an early exit if they don't). So, if anything
832 about @B.f@ changes we'd better make sure that something in A.hi
833 changes, and the convenient way to do that is to record the version
834 number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
835 complete recompiation of A, which is overkill but it's the only way to
836 write a new, slightly different, A.hi.
838 But the example is tricker. Even if @B.f@ doesn't change at all,
839 @B.h@ may do so, and this change may not be reflected in @f@'s version
840 number. But with -O, a module that imports A must be recompiled if
841 @B.h@ changes! So A must record a dependency on @B.h@. So we treat
842 the occurrence of @B.f@ in the export list *just as if* it were in the
843 code of A, and thereby haul in all the stuff reachable from it.
845 [NB: If B was compiled with -O, but A isn't, we should really *still*
846 haul in all the unfoldings for B, in case the module that imports A *is*
847 compiled with -O. I think this is the case.]
849 Even if B is used at all we get a usage line for B
850 import B <n> :: ... ;
851 in A.hi, to record the fact that A does import B. This is used to decide
852 to look to look for B.hi rather than B.hi-boot when compiling a module that
853 imports A. This line says that A imports B, but uses nothing in it.
854 So we'll get an early bale-out when compiling A if B's version changes.
857 mkImportExportInfo :: ModuleName -- Name of this module
858 -> Avails -- Info about exports
859 -> Maybe [RdrNameIE] -- The export header
860 -> RnMG ([ExportItem], -- Export info for iface file; sorted
861 [ImportVersion OccName]) -- Import info for iface file; sorted
862 -- Both results are sorted into canonical order to
863 -- reduce needless wobbling of interface files
865 mkImportExportInfo this_mod export_avails exports
866 = getIfacesRn `thenRn` \ ifaces ->
868 export_all_mods = case exports of
870 Just es -> [mod | IEModuleContents mod <- es,
873 mod_map = iImpModInfo ifaces
874 imp_names = iVSlurp ifaces
876 -- mv_map groups together all the things imported from a particular module.
877 mv_map :: FiniteMap ModuleName [(OccName,Version)]
878 mv_map = foldr add_mv emptyFM imp_names
880 add_mv (name, version) mv_map = addItem mv_map (moduleName (nameModule name))
881 (nameOccName name, version)
883 -- Build the result list by adding info for each module.
884 -- For (a) a library module, we don't record it at all unless it contains orphans
885 -- (We must never lose track of orphans.)
887 -- (b) a source-imported module, don't record the dependency at all
889 -- (b) may seem a bit strange. The idea is that the usages in a .hi file records
890 -- *all* the module's dependencies other than the loop-breakers. We use
891 -- this info in findAndReadInterface to decide whether to look for a .hi file or
894 -- This means we won't track version changes, or orphans, from .hi-boot files.
895 -- The former is potentially rather bad news. It could be fixed by recording
896 -- whether something is a boot file along with the usage info for it, but
897 -- I can't be bothered just now.
899 mk_imp_info mod_name (has_orphans, is_boot, contents) so_far
900 | mod_name == this_mod -- Check if M appears in the set of modules 'below' M
901 -- This seems like a convenient place to check
902 = WARN( not is_boot, ptext SLIT("Wierd:") <+> ppr this_mod <+>
903 ptext SLIT("imports itself (perhaps indirectly)") )
908 go_for_it exports = (mod_name, has_orphans, is_boot, exports)
912 Nothing -> -- We didn't even open the interface
913 -- This happens when a module, Foo, that we explicitly imported has
914 -- 'import Baz' in its interface file, recording that Baz is below
915 -- Foo in the module dependency hierarchy. We want to propagate this
916 -- information. The Nothing says that we didn't even open the interface
917 -- file but we must still propagate the dependeny info.
918 -- The module in question must be a local module (in the same package)
919 go_for_it NothingAtAll
921 Just (mod, mod_vers, fix_vers, rule_vers, how_imported, _)
922 | is_sys_import && is_lib_module && not has_orphans
925 | is_lib_module -- Record the module but not detailed
926 || mod_name `elem` export_all_mods -- version information for the imports
927 -> go_for_it (Everything mod_vers)
930 -> case lookupFM mv_map mod_name of
931 Just whats_imported -> go_for_it (Specifically mod_vers fix_vers rule_vers
932 (sortImport whats_imported))
933 Nothing -> go_for_it NothingAtAll
934 -- This happens if you have
936 -- but don't actually *use* anything from Foo
937 -- In which case record an empty dependency list
939 is_lib_module = not (isLocalModule mod)
940 is_sys_import = case how_imported of
941 ImportBySystem -> True
945 import_info = foldFM mk_imp_info [] mod_map
947 -- Sort exports into groups by module
948 export_fm :: FiniteMap ModuleName [RdrAvailInfo]
949 export_fm = foldr insert emptyFM export_avails
951 insert avail efm = addItem efm (moduleName (nameModule (availName avail)))
954 export_info = [(m, sortExport as) | (m,as) <- fmToList export_fm]
956 returnRn (export_info, import_info)
959 addItem :: FiniteMap ModuleName [a] -> ModuleName -> a -> FiniteMap ModuleName [a]
960 addItem fm mod x = addToFM_C add_item fm mod [x]
964 sortImport :: [(OccName,Version)] -> [(OccName,Version)]
965 -- Make the usage lists appear in canonical order
966 sortImport vs = sortLt lt vs
968 lt (n1,v1) (n2,v2) = n1 < n2
970 sortExport :: [RdrAvailInfo] -> [RdrAvailInfo]
971 sortExport as = sortLt lt as
973 lt a1 a2 = availName a1 < availName a2
978 = getIfacesRn `thenRn` \ ifaces ->
979 returnRn (iSlurp ifaces)
981 recordSlurp ifaces@(Ifaces { iSlurp = slurped_names, iVSlurp = imp_names })
984 new_slurped_names = addAvailToNameSet slurped_names avail
985 new_imp_names = (availName avail, version) : imp_names
987 ifaces { iSlurp = new_slurped_names, iVSlurp = new_imp_names }
989 recordLocalSlurps local_avails
990 = getIfacesRn `thenRn` \ ifaces ->
992 new_slurped_names = foldl addAvailToNameSet (iSlurp ifaces) local_avails
994 setIfacesRn (ifaces { iSlurp = new_slurped_names })
998 %*********************************************************
1000 \subsection{Getting binders out of a declaration}
1002 %*********************************************************
1004 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
1005 It's used for both source code (from @availsFromDecl@) and interface files
1008 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
1009 are handled by the sourc-code specific stuff in @RnNames@.
1012 getDeclBinders :: (RdrName -> SrcLoc -> RnM d Name) -- New-name function
1014 -> RnM d (Maybe AvailInfo)
1016 getDeclBinders new_name (TyClD (TyData _ _ tycon _ condecls _ _ _ src_loc))
1017 = new_name tycon src_loc `thenRn` \ tycon_name ->
1018 getConFieldNames new_name condecls `thenRn` \ sub_names ->
1019 returnRn (Just (AvailTC tycon_name (tycon_name : nub sub_names)))
1020 -- The "nub" is because getConFieldNames can legitimately return duplicates,
1021 -- when a record declaration has the same field in multiple constructors
1023 getDeclBinders new_name (TyClD (TySynonym tycon _ _ src_loc))
1024 = new_name tycon src_loc `thenRn` \ tycon_name ->
1025 returnRn (Just (AvailTC tycon_name [tycon_name]))
1027 getDeclBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ _ _ _ _ src_loc))
1028 = new_name cname src_loc `thenRn` \ class_name ->
1030 -- Record the names for the class ops
1032 -- just want class-op sigs
1033 op_sigs = filter isClassOpSig sigs
1035 mapRn (getClassOpNames new_name) op_sigs `thenRn` \ sub_names ->
1037 returnRn (Just (AvailTC class_name (class_name : sub_names)))
1039 getDeclBinders new_name (SigD (IfaceSig var ty prags src_loc))
1040 = new_name var src_loc `thenRn` \ var_name ->
1041 returnRn (Just (Avail var_name))
1043 getDeclBinders new_name (FixD _) = returnRn Nothing
1044 getDeclBinders new_name (DeprecD _) = returnRn Nothing
1046 -- foreign declarations
1047 getDeclBinders new_name (ForD (ForeignDecl nm kind _ dyn _ loc))
1048 | binds_haskell_name kind dyn
1049 = new_name nm loc `thenRn` \ name ->
1050 returnRn (Just (Avail name))
1052 | otherwise -- a foreign export
1053 = lookupOrigName nm `thenRn_`
1056 getDeclBinders new_name (DefD _) = returnRn Nothing
1057 getDeclBinders new_name (InstD _) = returnRn Nothing
1058 getDeclBinders new_name (RuleD _) = returnRn Nothing
1060 binds_haskell_name (FoImport _) _ = True
1061 binds_haskell_name FoLabel _ = True
1062 binds_haskell_name FoExport ext_nm = isDynamicExtName ext_nm
1065 getConFieldNames new_name (ConDecl con _ _ _ (RecCon fielddecls) src_loc : rest)
1066 = mapRn (\n -> new_name n src_loc) (con:fields) `thenRn` \ cfs ->
1067 getConFieldNames new_name rest `thenRn` \ ns ->
1068 returnRn (cfs ++ ns)
1070 fields = concat (map fst fielddecls)
1072 getConFieldNames new_name (ConDecl con _ _ _ condecl src_loc : rest)
1073 = new_name con src_loc `thenRn` \ n ->
1075 NewCon _ (Just f) ->
1076 new_name f src_loc `thenRn` \ new_f ->
1078 _ -> returnRn [n]) `thenRn` \ nn ->
1079 getConFieldNames new_name rest `thenRn` \ ns ->
1082 getConFieldNames new_name [] = returnRn []
1084 getClassOpNames new_name (ClassOpSig op _ _ src_loc) = new_name op src_loc
1087 @getDeclSysBinders@ gets the implicit binders introduced by a decl.
1088 A the moment that's just the tycon and datacon that come with a class decl.
1089 They aren't returned by @getDeclBinders@ because they aren't in scope;
1090 but they {\em should} be put into the @DeclsMap@ of this module.
1092 Note that this excludes the default-method names of a class decl,
1093 and the dict fun of an instance decl, because both of these have
1094 bindings of their own elsewhere.
1097 getDeclSysBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ tname dname dwname snames src_loc))
1098 = sequenceRn [new_name n src_loc | n <- (tname : dname : dwname : snames)]
1100 getDeclSysBinders new_name (TyClD (TyData _ _ _ _ cons _ _ _ _))
1101 = sequenceRn [new_name wkr_name src_loc | ConDecl _ wkr_name _ _ _ src_loc <- cons]
1103 getDeclSysBinders new_name other_decl
1107 %*********************************************************
1109 \subsection{Reading an interface file}
1111 %*********************************************************
1114 findAndReadIface :: SDoc -> ModuleName
1115 -> IsBootInterface -- True <=> Look for a .hi-boot file
1116 -- False <=> Look for .hi file
1117 -> RnM d (Either Message ParsedIface)
1118 -- Nothing <=> file not found, or unreadable, or illegible
1119 -- Just x <=> successfully found and parsed
1121 findAndReadIface doc_str mod_name hi_boot_file
1122 = traceRn trace_msg `thenRn_`
1123 -- we keep two maps for interface files,
1124 -- one for 'normal' ones, the other for .hi-boot files,
1125 -- hence the need to signal which kind we're interested.
1127 getHiMaps `thenRn` \ (search_path, hi_map, hiboot_map) ->
1129 relevant_map | hi_boot_file = hiboot_map
1130 | otherwise = hi_map
1132 case lookupFM relevant_map mod_name of
1134 Just fpath -> traceRn (ptext SLIT("...reading from") <+> text fpath) `thenRn_`
1135 readIface mod_name fpath
1138 Nothing -> traceRn (ptext SLIT("...not found")) `thenRn_`
1139 returnRn (Left (noIfaceErr mod_name hi_boot_file search_path))
1142 trace_msg = sep [hsep [ptext SLIT("Reading"),
1143 if hi_boot_file then ptext SLIT("[boot]") else empty,
1144 ptext SLIT("interface for"),
1145 pprModuleName mod_name <> semi],
1146 nest 4 (ptext SLIT("reason:") <+> doc_str)]
1149 @readIface@ tries just the one file.
1152 readIface :: ModuleName -> String -> RnM d (Either Message ParsedIface)
1153 -- Nothing <=> file not found, or unreadable, or illegible
1154 -- Just x <=> successfully found and parsed
1155 readIface wanted_mod file_path
1156 = ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
1159 case parseIface contents
1160 PState{ bol = 0#, atbol = 1#,
1163 loc = mkSrcLoc (mkFastString file_path) 1 } of
1164 POk _ (PIface iface) ->
1165 warnCheckRn (read_mod == wanted_mod)
1166 (hiModuleNameMismatchWarn wanted_mod read_mod) `thenRn_`
1167 returnRn (Right iface)
1169 read_mod = moduleName (pi_mod iface)
1171 PFailed err -> bale_out err
1172 parse_result -> bale_out empty
1173 -- This last case can happen if the interface file is (say) empty
1174 -- in which case the parser thinks it looks like an IdInfo or
1175 -- something like that. Just an artefact of the fact that the
1176 -- parser is used for several purposes at once.
1178 Left io_err -> bale_out (text (show io_err))
1180 bale_out err = returnRn (Left (badIfaceFile file_path err))
1183 %*********************************************************
1187 %*********************************************************
1190 noIfaceErr mod_name boot_file search_path
1191 = vcat [ptext SLIT("Could not find interface file for") <+> quotes (pprModuleName mod_name),
1192 ptext SLIT("in the directories") <+>
1193 -- \& to avoid cpp interpreting this string as a
1194 -- comment starter with a pre-4.06 mkdependHS --SDM
1195 vcat [ text dir <> text "/\&*" <> pp_suffix suffix
1196 | (dir,suffix) <- search_path]
1199 pp_suffix suffix | boot_file = ptext SLIT(".hi-boot")
1200 | otherwise = text suffix
1202 badIfaceFile file err
1203 = vcat [ptext SLIT("Bad interface file:") <+> text file,
1207 = vcat [ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name),
1208 ptext SLIT("from module") <+> quotes (ppr (nameModule name))
1211 getDeclWarn name loc
1212 = sep [ptext SLIT("Failed to find (optional) interface decl for") <+> quotes (ppr name),
1213 ptext SLIT("desired at") <+> ppr loc]
1217 "Compiler tried to import decl from interface file with same name as module."),
1219 "(possible cause: module name clashes with interface file already in scope.)")
1221 hsep [ptext SLIT("name:"), quotes (ppr name)]
1223 warnRedundantSourceImport mod_name
1224 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
1225 <+> quotes (pprModuleName mod_name)
1227 hiModuleNameMismatchWarn :: ModuleName -> ModuleName -> Message
1228 hiModuleNameMismatchWarn requested_mod read_mod =
1229 hsep [ ptext SLIT("Something is amiss; requested module name")
1230 , pprModuleName requested_mod
1231 , ptext SLIT("differs from name found in the interface file")
1232 , pprModuleName read_mod