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, loadBuiltinRules,
15 mkImportExportInfo, getSlurped,
17 getDeclBinders, getDeclSysBinders,
18 removeContext -- removeContext probably belongs somewhere else
22 #include "HsVersions.h"
24 import CmdLineOpts ( opt_NoPruneDecls, opt_NoPruneTyDecls, opt_IgnoreIfacePragmas )
25 import HsSyn ( HsDecl(..), TyClDecl(..), InstDecl(..), IfaceSig(..),
26 HsType(..), ConDecl(..), IE(..), ConDetails(..), Sig(..),
27 ForeignDecl(..), ForKind(..), isDynamicExtName,
28 FixitySig(..), RuleDecl(..),
29 isClassOpSig, DeprecDecl(..)
31 import HsImpExp ( ImportDecl(..), ieNames )
32 import CoreSyn ( CoreRule )
33 import BasicTypes ( Version, defaultFixity )
34 import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameRuleDecl,
35 RdrNameDeprecation, RdrNameIE,
40 import ParseIface ( parseIface, IfaceStuff(..) )
42 import Name ( Name {-instance NamedThing-}, nameOccName,
43 nameModule, isLocallyDefined,
45 mkNameEnv, elemNameEnv, extendNameEnv
47 import Module ( Module, ModuleEnv,
48 moduleName, isModuleInThisPackage,
49 ModuleName, WhereFrom(..),
50 extendModuleEnv, lookupModuleEnv, lookupModuleEnvByName,
51 plusModuleEnv_C, lookupWithDefaultModuleEnv
53 import RdrName ( RdrName, rdrNameOcc )
55 import SrcLoc ( mkSrcLoc, SrcLoc )
56 import PrelInfo ( cCallishTyKeys, wiredInThingEnv )
57 import Maybes ( maybeToBool, orElse )
58 import StringBuffer ( hGetStringBuffer )
59 import FastString ( mkFastString )
60 import ErrUtils ( Message )
61 import Util ( sortLt )
72 %*********************************************************
74 \subsection{Loading a new interface file}
76 %*********************************************************
79 loadHomeInterface :: SDoc -> Name -> RnM d Ifaces
80 loadHomeInterface doc_str name
81 = loadInterface doc_str (moduleName (nameModule name)) ImportBySystem
83 loadOrphanModules :: [ModuleName] -> RnM d ()
84 loadOrphanModules mods
85 | null mods = returnRn ()
86 | otherwise = traceRn (text "Loading orphan modules:" <+>
87 fsep (map ppr mods)) `thenRn_`
88 mapRn_ load mods `thenRn_`
91 load mod = loadInterface (mk_doc mod) mod ImportBySystem
92 mk_doc mod = ppr mod <+> ptext SLIT("is a orphan-instance module")
95 loadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d Ifaces
96 loadInterface doc mod from
97 = tryLoadInterface doc mod from `thenRn` \ (ifaces, maybe_err) ->
99 Nothing -> returnRn ifaces
100 Just err -> failWithRn ifaces err
102 tryLoadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d (Ifaces, Maybe Message)
103 -- Returns (Just err) if an error happened
104 -- Guarantees to return with iImpModInfo m --> (... Just cts)
105 -- (If the load fails, we plug in a vanilla placeholder
106 tryLoadInterface doc_str mod_name from
107 = getIfacesRn `thenRn` \ ifaces ->
109 mod_map = iImpModInfo ifaces
110 mod_info = lookupFM mod_map mod_name
113 = case (from, mod_info) of
114 (ImportByUser, _) -> False -- Not hi-boot
115 (ImportByUserSource, _) -> True -- hi-boot
116 (ImportBySystem, Just (_, is_boot, _)) -> is_boot --
117 (ImportBySystem, Nothing) -> False
118 -- We're importing a module we know absolutely
119 -- nothing about, so we assume it's from
120 -- another package, where we aren't doing
121 -- dependency tracking. So it won't be a hi-boot file.
123 redundant_source_import
124 = case (from, mod_info) of
125 (ImportByUserSource, Just (_,False,_)) -> True
128 -- CHECK WHETHER WE HAVE IT ALREADY
131 -> -- We're read it already so don't re-read it
132 returnRn (ifaces, Nothing) ;
136 -- Issue a warning for a redundant {- SOURCE -} import
137 -- NB that we arrange to read all the ordinary imports before
138 -- any of the {- SOURCE -} imports
139 warnCheckRn (not redundant_source_import)
140 (warnRedundantSourceImport mod_name) `thenRn_`
142 -- READ THE MODULE IN
143 findAndReadIface doc_str mod_name hi_boot_file `thenRn` \ read_result ->
144 case read_result of {
145 Left err -> -- Not found, so add an empty export env to the Ifaces map
146 -- so that we don't look again
148 new_mod_map = addToFM mod_map mod_name (False, False, True)
149 new_ifaces = ifaces { iImpModInfo = new_mod_map }
151 setIfacesRn new_ifaces `thenRn_`
152 returnRn (new_ifaces, Just err) ;
155 Right (mod, iface) ->
157 -- LOAD IT INTO Ifaces
159 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
160 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
161 -- If we do loadExport first the wrong info gets into the cache (unless we
162 -- explicitly tag each export which seems a bit of a bore)
165 -- Sanity check. If we're system-importing a module we know nothing at all
166 -- about, it should be from a different package to this one
167 WARN( not (maybeToBool mod_info) &&
168 case from of { ImportBySystem -> True; other -> False } &&
169 isModuleInThisPackage mod,
172 loadDecls mod (iDecls ifaces) (pi_decls iface) `thenRn` \ (decls_vers, new_decls) ->
173 loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ (rule_vers, new_rules) ->
174 loadFixDecls mod_name (pi_fixity iface) `thenRn` \ (fix_vers, fix_env) ->
175 foldlRn (loadDeprec mod) emptyNameEnv (pi_deprecs iface) `thenRn` \ deprec_env ->
176 foldlRn (loadInstDecl mod) (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
177 loadExports (pi_exports iface) `thenRn` \ avails ->
179 version = VersionInfo { vers_module = pi_vers iface,
181 vers_rules = rule_vers,
182 vers_decls = decls_vers }
184 -- For an explicit user import, add to mod_map info about
185 -- the things the imported module depends on, extracted
186 -- from its usage info.
187 mod_map1 = case from of
188 ImportByUser -> addModDeps mod (pi_usages iface) mod_map
190 mod_map2 = addToFM mod_map1 mod_name (has_orphans, hi_boot_file, True)
192 -- Now add info about this module to the PIT
193 has_orphans = pi_orphan iface
194 new_pit = extendModuleEnv (iPIT ifaces) mod mod_iface
195 mod_iface = ModIface { mi_module = mod, mi_version = version,
196 mi_exports = avails, mi_orphan = has_orphans,
197 mi_fixities = fix_env, mi_deprecs = deprec_env,
198 mi_usages = [], -- Will be filled in later
199 mi_decls = panic "No mi_decls in PIT",
200 mi_globals = panic "No mi_globals in PIT"
203 new_ifaces = ifaces { iPIT = new_pit,
207 iImpModInfo = mod_map2 }
209 setIfacesRn new_ifaces `thenRn_`
210 returnRn (new_ifaces, Nothing)
213 -----------------------------------------------------
214 -- Adding module dependencies from the
215 -- import decls in the interface file
216 -----------------------------------------------------
218 addModDeps :: Module -> [ImportVersion a]
219 -> ImportedModuleInfo -> ImportedModuleInfo
220 -- (addModDeps M ivs deps)
221 -- We are importing module M, and M.hi contains 'import' decls given by ivs
222 addModDeps mod new_deps mod_deps
223 = foldr add mod_deps filtered_new_deps
225 -- Don't record dependencies when importing a module from another package
226 -- Except for its descendents which contain orphans,
227 -- and in that case, forget about the boot indicator
228 filtered_new_deps :: [(ModuleName, (WhetherHasOrphans, IsBootInterface))]
230 | isModuleInThisPackage mod
231 = [ (imp_mod, (has_orphans, is_boot, False))
232 | (imp_mod, has_orphans, is_boot, _) <- new_deps
234 | otherwise = [ (imp_mod, (True, False, False))
235 | (imp_mod, has_orphans, _, _) <- new_deps,
238 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
240 combine old@(_, old_is_boot, old_is_loaded) new
241 | old_is_loaded || not old_is_boot = old -- Keep the old info if it's already loaded
242 -- or if it's a non-boot pending load
243 | otherwise = new -- Otherwise pick new info
246 -----------------------------------------------------
247 -- Loading the export list
248 -----------------------------------------------------
250 loadExports :: [ExportItem] -> RnM d Avails
252 = getModuleRn `thenRn` \ this_mod ->
253 mapRn (loadExport this_mod) items `thenRn` \ avails_s ->
254 returnRn (concat avails_s)
257 loadExport :: Module -> ExportItem -> RnM d [AvailInfo]
258 loadExport this_mod (mod, entities)
259 | mod == moduleName this_mod = returnRn []
260 -- If the module exports anything defined in this module, just ignore it.
261 -- Reason: otherwise it looks as if there are two local definition sites
262 -- for the thing, and an error gets reported. Easiest thing is just to
263 -- filter them out up front. This situation only arises if a module
264 -- imports itself, or another module that imported it. (Necessarily,
265 -- this invoves a loop.) Consequence: if you say
270 -- module B( AType ) where
271 -- import {-# SOURCE #-} A( AType )
273 -- then you'll get a 'B does not export AType' message. A bit bogus
274 -- but it's a bogus thing to do!
277 = mapRn (load_entity mod) entities
279 new_name mod occ = newGlobalName mod occ
281 load_entity mod (Avail occ)
282 = new_name mod occ `thenRn` \ name ->
283 returnRn (Avail name)
284 load_entity mod (AvailTC occ occs)
285 = new_name mod occ `thenRn` \ name ->
286 mapRn (new_name mod) occs `thenRn` \ names ->
287 returnRn (AvailTC name names)
290 -----------------------------------------------------
291 -- Loading type/class/value decls
292 -----------------------------------------------------
296 -> [(Version, RdrNameHsDecl)]
297 -> RnM d (NameEnv Version, DeclsMap)
298 loadDecls mod decls_map decls
299 = foldlRn (loadDecl mod) (emptyNameEnv, decls_map) decls
302 -> (NameEnv Version, DeclsMap)
303 -> (Version, RdrNameHsDecl)
304 -> RnM d (NameEnv Version, DeclsMap)
305 loadDecl mod (version_map, decls_map) (version, decl)
306 = getDeclBinders new_name decl `thenRn` \ maybe_avail ->
307 case maybe_avail of {
308 Nothing -> returnRn (version_map, decls_map); -- No bindings
311 getDeclSysBinders new_name decl `thenRn` \ sys_bndrs ->
313 full_avail = addSysAvails avail sys_bndrs
314 -- Add the sys-binders to avail. When we import the decl,
315 -- it's full_avail that will get added to the 'already-slurped' set (iSlurp)
316 -- If we miss out sys-binders, we'll read the decl multiple times!
318 main_name = availName avail
319 new_decls_map = foldl add_decl decls_map
320 [ (name, (full_avail, name==main_name, (mod, decl')))
321 | name <- availNames full_avail]
322 add_decl decls_map (name, stuff)
323 = WARN( name `elemNameEnv` decls_map, ppr name )
324 extendNameEnv decls_map name stuff
326 new_version_map = extendNameEnv version_map main_name version
328 returnRn (new_version_map, new_decls_map)
331 -- newTopBinder puts into the cache the binder with the
332 -- module information set correctly. When the decl is later renamed,
333 -- the binding site will thereby get the correct module.
334 -- There maybe occurrences that don't have the correct Module, but
335 -- by the typechecker will propagate the binding definition to all
336 -- the occurrences, so that doesn't matter
337 new_name rdr_name loc = newTopBinder mod rdr_name loc
340 If a signature decl is being loaded, and optIgnoreIfacePragmas is on,
341 we toss away unfolding information.
343 Also, if the signature is loaded from a module we're importing from source,
344 we do the same. This is to avoid situations when compiling a pair of mutually
345 recursive modules, peering at unfolding info in the interface file of the other,
346 e.g., you compile A, it looks at B's interface file and may as a result change
347 its interface file. Hence, B is recompiled, maybe changing its interface file,
348 which will the unfolding info used in A to become invalid. Simple way out is to
349 just ignore unfolding info.
351 [Jan 99: I junked the second test above. If we're importing from an hi-boot
352 file there isn't going to *be* any pragma info. Maybe the above comment
353 dates from a time where we picked up a .hi file first if it existed?]
356 SigD (IfaceSig name tp ls loc) | opt_IgnoreIfacePragmas
357 -> SigD (IfaceSig name tp [] loc)
360 -----------------------------------------------------
361 -- Loading fixity decls
362 -----------------------------------------------------
364 loadFixDecls mod_name (version, decls)
365 = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
366 returnRn (version, mkNameEnv to_add)
368 loadFixDecl mod_name sig@(FixitySig rdr_name fixity loc)
369 = newGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
370 returnRn (name, fixity)
373 -----------------------------------------------------
374 -- Loading instance decls
375 -----------------------------------------------------
377 loadInstDecl :: Module
381 loadInstDecl mod insts decl@(InstDecl inst_ty binds uprags dfun_name src_loc)
383 -- Find out what type constructors and classes are "gates" for the
384 -- instance declaration. If all these "gates" are slurped in then
385 -- we should slurp the instance decl too.
387 -- We *don't* want to count names in the context part as gates, though.
389 -- instance Foo a => Baz (T a) where ...
391 -- Here the gates are Baz and T, but *not* Foo.
393 munged_inst_ty = removeContext inst_ty
394 free_names = extractHsTyRdrNames munged_inst_ty
397 mapRn lookupOrigName free_names `thenRn` \ gate_names ->
398 returnRn ((mkNameSet gate_names, (mod, InstD decl)) `consBag` insts)
401 -- In interface files, the instance decls now look like
402 -- forall a. Foo a -> Baz (T a)
403 -- so we have to strip off function argument types as well
404 -- as the bit before the '=>' (which is always empty in interface files)
405 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
406 removeContext ty = removeFuns ty
408 removeFuns (HsFunTy _ ty) = removeFuns ty
412 -----------------------------------------------------
414 -----------------------------------------------------
416 loadRules :: Module -> IfaceRules
417 -> (Version, [RdrNameRuleDecl])
418 -> RnM d (Version, IfaceRules)
419 loadRules mod rule_bag (version, rules)
420 | null rules || opt_IgnoreIfacePragmas
421 = returnRn (version, rule_bag)
424 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
425 returnRn (version, rule_bag `unionBags` listToBag new_rules)
427 loadRule :: Module -> RdrNameRuleDecl -> RnM d GatedDecl
428 -- "Gate" the rule simply by whether the rule variable is
429 -- needed. We can refine this later.
430 loadRule mod decl@(IfaceRule _ _ var _ _ src_loc)
431 = lookupOrigName var `thenRn` \ var_name ->
432 returnRn (unitNameSet var_name, (mod, RuleD decl))
434 loadBuiltinRules :: [(RdrName, CoreRule)] -> RnMG ()
435 loadBuiltinRules builtin_rules
436 = getIfacesRn `thenRn` \ ifaces ->
437 mapRn loadBuiltinRule builtin_rules `thenRn` \ rule_decls ->
438 setIfacesRn (ifaces { iRules = iRules ifaces `unionBags` listToBag rule_decls })
440 loadBuiltinRule (var, rule)
441 = lookupOrigName var `thenRn` \ var_name ->
442 returnRn (unitNameSet var_name, (nameModule var_name, RuleD (IfaceRuleOut var rule)))
445 -----------------------------------------------------
446 -- Loading Deprecations
447 -----------------------------------------------------
449 loadDeprec :: Module -> DeprecationEnv -> RdrNameDeprecation -> RnM d DeprecationEnv
450 loadDeprec mod deprec_env (Deprecation (IEModuleContents _) txt _)
451 = traceRn (text "module deprecation not yet implemented:" <+> ppr mod <> colon <+> ppr txt) `thenRn_`
452 -- SUP: TEMPORARY HACK, ignoring module deprecations for now
455 loadDeprec mod deprec_env (Deprecation ie txt _)
457 mapRn lookupOrigName (ieNames ie) `thenRn` \ names ->
458 traceRn (text "loaded deprecation(s) for" <+> hcat (punctuate comma (map ppr names)) <> colon <+> ppr txt) `thenRn_`
459 returnRn (extendNameEnvList deprec_env (zip names (repeat txt)))
463 %*********************************************************
465 \subsection{Getting in a declaration}
467 %*********************************************************
470 importDecl :: Name -> RnMG ImportDeclResult
472 data ImportDeclResult
476 | HereItIs (Module, RdrNameHsDecl)
479 = -- Check if it was loaded before beginning this module
480 checkAlreadyAvailable name `thenRn` \ done ->
482 returnRn AlreadySlurped
485 -- Check if we slurped it in while compiling this module
486 getIfacesRn `thenRn` \ ifaces ->
487 if name `elemNameSet` iSlurp ifaces then
488 returnRn AlreadySlurped
491 -- Don't slurp in decls from this module's own interface file
492 -- (Indeed, this shouldn't happen.)
493 if isLocallyDefined name then
494 addWarnRn (importDeclWarn name) `thenRn_`
495 returnRn AlreadySlurped
498 -- When we find a wired-in name we must load its home
499 -- module so that we find any instance decls lurking therein
500 if name `elemNameEnv` wiredInThingEnv then
501 loadHomeInterface doc name `thenRn_`
504 else getNonWiredInDecl name
506 doc = ptext SLIT("need home module for wired in thing") <+> ppr name
508 getNonWiredInDecl :: Name -> RnMG ImportDeclResult
509 getNonWiredInDecl needed_name
510 = traceRn doc_str `thenRn_`
511 loadHomeInterface doc_str needed_name `thenRn` \ ifaces ->
512 case lookupNameEnv (iDecls ifaces) needed_name of
514 {- OMIT DEFERRED STUFF FOR NOW, TILL GHCI WORKS
515 Just (version, avail, is_tycon_name, decl@(_, TyClD (TyData DataType _ _ _ _ ncons _ _ _ _ _)))
516 -- This case deals with deferred import of algebraic data types
518 | not opt_NoPruneTyDecls
520 && (opt_IgnoreIfacePragmas || ncons > 1)
521 -- We only defer if imported interface pragmas are ingored
522 -- or if it's not a product type.
523 -- Sole reason: The wrapper for a strict function may need to look
524 -- inside its arg, and hence need to see its arg type's constructors.
526 && not (getUnique tycon_name `elem` cCallishTyKeys)
527 -- Never defer ccall types; we have to unbox them,
528 -- and importing them does no harm
531 -> -- OK, so we're importing a deferrable data type
532 if needed_name == tycon_name
533 -- The needed_name is the TyCon of a data type decl
534 -- Record that it's slurped, put it in the deferred set
535 -- and don't return a declaration at all
536 setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces
537 `addOneToNameSet` tycon_name})
538 version (AvailTC needed_name [needed_name])) `thenRn_`
542 -- The needed name is a constructor of a data type decl,
543 -- getting a constructor, so remove the TyCon from the deferred set
544 -- (if it's there) and return the full declaration
545 setIfacesRn (recordSlurp (ifaces {iDeferred = iDeferred ifaces
546 `delFromNameSet` tycon_name})
547 version avail) `thenRn_`
548 returnRn (HereItIs decl)
550 tycon_name = availName avail
554 -> setIfacesRn (recordSlurp ifaces avail) `thenRn_`
555 returnRn (HereItIs decl)
558 -> addErrRn (getDeclErr needed_name) `thenRn_`
559 returnRn AlreadySlurped
561 doc_str = ptext SLIT("need decl for") <+> ppr needed_name
564 getDeferredDecls :: RnMG [(Module, RdrNameHsDecl)]
566 = getIfacesRn `thenRn` \ ifaces ->
568 decls_map = iDecls ifaces
569 deferred_names = nameSetToList (iDeferred ifaces)
570 get_abstract_decl n = case lookupNameEnv decls_map n of
571 Just (_, _, _, decl) -> decl
573 traceRn (sep [text "getDeferredDecls", nest 4 (fsep (map ppr deferred_names))]) `thenRn_`
574 returnRn (map get_abstract_decl deferred_names)
578 @getWiredInDecl@ maps a wired-in @Name@ to what it makes available.
579 It behaves exactly as if the wired in decl were actually in an interface file.
582 \item if the wired-in name is a data type constructor or a data constructor,
583 it brings in the type constructor and all the data constructors; and
584 marks as ``occurrences'' any free vars of the data con.
586 \item similarly for synonum type constructor
588 \item if the wired-in name is another wired-in Id, it marks as ``occurrences''
589 the free vars of the Id's type.
591 \item it loads the interface file for the wired-in thing for the
592 sole purpose of making sure that its instance declarations are available
594 All this is necessary so that we know all types that are ``in play'', so
595 that we know just what instances to bring into scope.
600 %*********************************************************
602 \subsection{Getting what a module exports}
604 %*********************************************************
606 @getInterfaceExports@ is called only for directly-imported modules.
609 getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, Avails)
610 getInterfaceExports mod_name from
611 = getHomeIfaceTableRn `thenRn` \ hit ->
612 case lookupModuleEnvByName hit mod_name of {
613 Just mi -> returnRn (mi_module mi, mi_exports mi) ;
616 loadInterface doc_str mod_name from `thenRn` \ ifaces ->
617 case lookupModuleEnvByName (iPIT ifaces) mod_name of
618 Just mi -> returnRn (mi_module mi, mi_exports mi) ;
619 -- loadInterface always puts something in the map
620 -- even if it's a fake
621 Nothing -> pprPanic "getInterfaceExports" (ppr mod_name)
624 doc_str = sep [ppr mod_name, ptext SLIT("is directly imported")]
628 %*********************************************************
630 \subsection{Instance declarations are handled specially}
632 %*********************************************************
635 getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)]
636 getImportedInstDecls gates
637 = -- First, load any orphan-instance modules that aren't aready loaded
638 -- Orphan-instance modules are recorded in the module dependecnies
639 getIfacesRn `thenRn` \ ifaces ->
642 [mod | (mod, (True, _, False)) <- fmToList (iImpModInfo ifaces)]
644 loadOrphanModules orphan_mods `thenRn_`
646 -- Now we're ready to grab the instance declarations
647 -- Find the un-gated ones and return them,
648 -- removing them from the bag kept in Ifaces
649 getIfacesRn `thenRn` \ ifaces ->
651 (decls, new_insts) = selectGated gates (iInsts ifaces)
653 setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_`
655 traceRn (sep [text "getImportedInstDecls:",
656 nest 4 (fsep (map ppr gate_list)),
657 text "Slurped" <+> int (length decls) <+> text "instance declarations",
658 nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_`
661 gate_list = nameSetToList gates
663 ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _))
665 HsForAllTy _ _ tau -> ppr tau
668 getImportedRules :: RnMG [(Module,RdrNameHsDecl)]
670 | opt_IgnoreIfacePragmas = returnRn []
672 = getIfacesRn `thenRn` \ ifaces ->
674 gates = iSlurp ifaces -- Anything at all that's been slurped
675 rules = iRules ifaces
676 (decls, new_rules) = selectGated gates rules
681 setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
682 traceRn (sep [text "getImportedRules:",
683 text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
686 selectGated gates decl_bag
687 -- Select only those decls whose gates are *all* in 'gates'
689 | opt_NoPruneDecls -- Just to try the effect of not gating at all
690 = (foldrBag (\ (_,d) ds -> d:ds) [] decl_bag, emptyBag) -- Grab them all
694 = foldrBag select ([], emptyBag) decl_bag
696 select (reqd, decl) (yes, no)
697 | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no)
698 | otherwise = (yes, (reqd,decl) `consBag` no)
700 lookupFixityRn :: Name -> RnMS Fixity
702 | isLocallyDefined name
703 = getFixityEnv `thenRn` \ local_fix_env ->
704 returnRn (lookupLocalFixity local_fix_env name)
706 | otherwise -- Imported
707 -- For imported names, we have to get their fixities by doing a loadHomeInterface,
708 -- and consulting the Ifaces that comes back from that, because the interface
709 -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
710 -- which exports a function 'f', which is defined in module B. Then B isn't loaded
711 -- right away (after all, it's possible that nothing from B will be used).
712 -- When we come across a use of 'f', we need to know its fixity, and it's then,
713 -- and only then, that we load B.hi. That is what's happening here.
714 = getHomeIfaceTableRn `thenRn` \ hst ->
715 case lookupFixityEnv hst name of {
716 Just fixity -> returnRn fixity ;
719 loadHomeInterface doc name `thenRn` \ ifaces ->
720 returnRn (lookupFixityEnv (iPIT ifaces) name `orElse` defaultFixity)
723 doc = ptext SLIT("Checking fixity for") <+> ppr name
727 %*********************************************************
729 \subsection{Keeping track of what we've slurped, and version numbers}
731 %*********************************************************
733 getImportVersions figures out what the ``usage information'' for this
734 moudule is; that is, what it must record in its interface file as the
735 things it uses. It records:
738 \item (a) anything reachable from its body code
739 \item (b) any module exported with a @module Foo@
740 \item (c) anything reachable from an exported item
743 Why (b)? Because if @Foo@ changes then this module's export list
744 will change, so we must recompile this module at least as far as
745 making a new interface file --- but in practice that means complete
748 Why (c)? Consider this:
750 module A( f, g ) where | module B( f ) where
751 import B( f ) | f = h 3
755 Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
756 @A@'s usages? Our idea is that we aren't going to touch A.hi if it is
757 *identical* to what it was before. If anything about @B.f@ changes
758 than anyone who imports @A@ should be recompiled in case they use
759 @B.f@ (they'll get an early exit if they don't). So, if anything
760 about @B.f@ changes we'd better make sure that something in A.hi
761 changes, and the convenient way to do that is to record the version
762 number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
763 complete recompiation of A, which is overkill but it's the only way to
764 write a new, slightly different, A.hi.
766 But the example is tricker. Even if @B.f@ doesn't change at all,
767 @B.h@ may do so, and this change may not be reflected in @f@'s version
768 number. But with -O, a module that imports A must be recompiled if
769 @B.h@ changes! So A must record a dependency on @B.h@. So we treat
770 the occurrence of @B.f@ in the export list *just as if* it were in the
771 code of A, and thereby haul in all the stuff reachable from it.
773 [NB: If B was compiled with -O, but A isn't, we should really *still*
774 haul in all the unfoldings for B, in case the module that imports A *is*
775 compiled with -O. I think this is the case.]
777 Even if B is used at all we get a usage line for B
778 import B <n> :: ... ;
779 in A.hi, to record the fact that A does import B. This is used to decide
780 to look to look for B.hi rather than B.hi-boot when compiling a module that
781 imports A. This line says that A imports B, but uses nothing in it.
782 So we'll get an early bale-out when compiling A if B's version changes.
785 mkImportExportInfo :: ModuleName -- Name of this module
786 -> Avails -- Info about exports
787 -> [ImportDecl n] -- The import decls
788 -> RnMG ([ExportItem], -- Export info for iface file; sorted
789 [ImportVersion Name]) -- Import info for iface file; sorted
790 -- Both results are sorted into canonical order to
791 -- reduce needless wobbling of interface files
793 mkImportExportInfo this_mod export_avails exports
794 = getIfacesRn `thenRn` \ ifaces ->
796 import_all_mods :: [ModuleName]
797 -- Modules where we imported all the names
798 -- (apart from hiding some, perhaps)
799 import_all_mods = nub [ m | ImportDecl m _ _ _ imp_list _ <- imports ]
801 import_all (Just (False, _)) = False -- Imports are specified explicitly
802 import_all other = True -- Everything is imported
804 mod_map = iImpModInfo ifaces
805 imp_names = iVSlurp ifaces
807 -- mv_map groups together all the things imported from a particular module.
808 mv_map :: ModuleEnv [Name]
809 mv_map = foldr add_mv emptyFM imp_names
811 add_mv (name, version) mv_map = addItem mv_map (nameModule name) name
813 -- Build the result list by adding info for each module.
814 -- For (a) a library module, we don't record it at all unless it contains orphans
815 -- (We must never lose track of orphans.)
817 -- (b) a source-imported module, don't record the dependency at all
819 -- (b) may seem a bit strange. The idea is that the usages in a .hi file records
820 -- *all* the module's dependencies other than the loop-breakers. We use
821 -- this info in findAndReadInterface to decide whether to look for a .hi file or
824 -- This means we won't track version changes, or orphans, from .hi-boot files.
825 -- The former is potentially rather bad news. It could be fixed by recording
826 -- whether something is a boot file along with the usage info for it, but
827 -- I can't be bothered just now.
829 mk_imp_info mod_name (has_orphans, is_boot, opened) so_far
830 | mod_name == this_mod -- Check if M appears in the set of modules 'below' M
831 -- This seems like a convenient place to check
832 = WARN( not is_boot, ptext SLIT("Wierd:") <+> ppr this_mod <+>
833 ptext SLIT("imports itself (perhaps indirectly)") )
836 | not opened -- We didn't even open the interface
837 = -- This happens when a module, Foo, that we explicitly imported has
838 -- 'import Baz' in its interface file, recording that Baz is below
839 -- Foo in the module dependency hierarchy. We want to propagate this
840 -- information. The Nothing says that we didn't even open the interface
841 -- file but we must still propagate the dependency info.
842 -- The module in question must be a local module (in the same package)
843 go_for_it NothingAtAll
846 | is_lib_module && not has_orphans
849 | is_lib_module -- Record the module version only
850 = go_for_it (Everything vers_module)
853 = go_for_it (mk_whats_imported mod vers_module)
856 go_for_it exports = (mod_name, has_orphans, is_boot, exports) : so_far
857 mod_iface = lookupIface hit pit mod_name
858 mod = mi_module mod_iface
859 is_lib_module = not (isModuleInThisPackage mod)
860 version_info = mi_version mod_iface
861 version_env = vers_decls version_info
863 whats_imported = Specifically mod_vers export_vers import_items
864 (vers_rules version_info)
866 import_items = [(n,v) | n <- lookupWithDefaultModuleEnv mv_map [] mod,
867 let v = lookupNameEnv version_env `orElse`
868 pprPanic "mk_whats_imported" (ppr n)
870 export_vers | moduleName mod `elem` import_all_mods
871 = Just (vers_exports version_info)
875 import_info = foldFM mk_imp_info [] mod_map
877 -- Sort exports into groups by module
878 export_fm :: FiniteMap Module [RdrAvailInfo]
879 export_fm = foldr insert emptyFM export_avails
881 insert avail efm = addItem efm (nameModule (availName avail))
884 export_info = fmToList export_fm
886 traceRn (text "Modules in Ifaces: " <+> fsep (map ppr (keysFM mod_map))) `thenRn_`
887 returnRn (export_info, import_info)
890 addItem :: ModuleEnv [a] -> Module -> a -> ModuleEnv [a]
891 addItem fm mod x = plusModuleEnv_C add_item fm mod [x]
898 = getIfacesRn `thenRn` \ ifaces ->
899 returnRn (iSlurp ifaces)
901 recordSlurp ifaces@(Ifaces { iSlurp = slurped_names, iVSlurp = imp_names })
904 new_slurped_names = addAvailToNameSet slurped_names avail
905 new_imp_names = availName avail : imp_names
907 ifaces { iSlurp = new_slurped_names, iVSlurp = new_imp_names }
909 recordLocalSlurps local_avails
910 = getIfacesRn `thenRn` \ ifaces ->
912 new_slurped_names = foldl addAvailToNameSet (iSlurp ifaces) local_avails
914 setIfacesRn (ifaces { iSlurp = new_slurped_names })
918 %*********************************************************
920 \subsection{Getting binders out of a declaration}
922 %*********************************************************
924 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
925 It's used for both source code (from @availsFromDecl@) and interface files
928 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
929 are handled by the sourc-code specific stuff in @RnNames@.
932 getDeclBinders :: (RdrName -> SrcLoc -> RnM d Name) -- New-name function
934 -> RnM d (Maybe AvailInfo)
936 getDeclBinders new_name (TyClD (TyData _ _ tycon _ condecls _ _ _ src_loc _ _))
937 = new_name tycon src_loc `thenRn` \ tycon_name ->
938 getConFieldNames new_name condecls `thenRn` \ sub_names ->
939 returnRn (Just (AvailTC tycon_name (tycon_name : nub sub_names)))
940 -- The "nub" is because getConFieldNames can legitimately return duplicates,
941 -- when a record declaration has the same field in multiple constructors
943 getDeclBinders new_name (TyClD (TySynonym tycon _ _ src_loc))
944 = new_name tycon src_loc `thenRn` \ tycon_name ->
945 returnRn (Just (AvailTC tycon_name [tycon_name]))
947 getDeclBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ _ src_loc))
948 = new_name cname src_loc `thenRn` \ class_name ->
950 -- Record the names for the class ops
952 -- just want class-op sigs
953 op_sigs = filter isClassOpSig sigs
955 mapRn (getClassOpNames new_name) op_sigs `thenRn` \ sub_names ->
957 returnRn (Just (AvailTC class_name (class_name : sub_names)))
959 getDeclBinders new_name (SigD (IfaceSig var ty prags src_loc))
960 = new_name var src_loc `thenRn` \ var_name ->
961 returnRn (Just (Avail var_name))
963 getDeclBinders new_name (FixD _) = returnRn Nothing
964 getDeclBinders new_name (DeprecD _) = returnRn Nothing
966 -- foreign declarations
967 getDeclBinders new_name (ForD (ForeignDecl nm kind _ dyn _ loc))
968 | binds_haskell_name kind dyn
969 = new_name nm loc `thenRn` \ name ->
970 returnRn (Just (Avail name))
972 | otherwise -- a foreign export
973 = lookupOrigName nm `thenRn_`
976 getDeclBinders new_name (DefD _) = returnRn Nothing
977 getDeclBinders new_name (InstD _) = returnRn Nothing
978 getDeclBinders new_name (RuleD _) = returnRn Nothing
980 binds_haskell_name (FoImport _) _ = True
981 binds_haskell_name FoLabel _ = True
982 binds_haskell_name FoExport ext_nm = isDynamicExtName ext_nm
985 getConFieldNames new_name (ConDecl con _ _ _ (RecCon fielddecls) src_loc : rest)
986 = mapRn (\n -> new_name n src_loc) (con:fields) `thenRn` \ cfs ->
987 getConFieldNames new_name rest `thenRn` \ ns ->
990 fields = concat (map fst fielddecls)
992 getConFieldNames new_name (ConDecl con _ _ _ condecl src_loc : rest)
993 = new_name con src_loc `thenRn` \ n ->
994 getConFieldNames new_name rest `thenRn` \ ns ->
997 getConFieldNames new_name [] = returnRn []
999 getClassOpNames new_name (ClassOpSig op _ _ src_loc) = new_name op src_loc
1002 @getDeclSysBinders@ gets the implicit binders introduced by a decl.
1003 A the moment that's just the tycon and datacon that come with a class decl.
1004 They aren't returned by @getDeclBinders@ because they aren't in scope;
1005 but they {\em should} be put into the @DeclsMap@ of this module.
1007 Note that this excludes the default-method names of a class decl,
1008 and the dict fun of an instance decl, because both of these have
1009 bindings of their own elsewhere.
1012 getDeclSysBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ names
1014 = sequenceRn [new_name n src_loc | n <- names]
1016 getDeclSysBinders new_name (TyClD (TyData _ _ _ _ cons _ _ _ _ _ _))
1017 = sequenceRn [new_name wkr_name src_loc | ConDecl _ wkr_name _ _ _ src_loc <- cons]
1019 getDeclSysBinders new_name other_decl
1023 %*********************************************************
1025 \subsection{Reading an interface file}
1027 %*********************************************************
1030 findAndReadIface :: SDoc -> ModuleName
1031 -> IsBootInterface -- True <=> Look for a .hi-boot file
1032 -- False <=> Look for .hi file
1033 -> RnM d (Either Message (Module, ParsedIface))
1034 -- Nothing <=> file not found, or unreadable, or illegible
1035 -- Just x <=> successfully found and parsed
1037 findAndReadIface doc_str mod_name hi_boot_file
1038 = traceRn trace_msg `thenRn_`
1039 -- we keep two maps for interface files,
1040 -- one for 'normal' ones, the other for .hi-boot files,
1041 -- hence the need to signal which kind we're interested.
1043 getFinderRn `thenRn` \ finder ->
1044 ioToRnM (finder mod_name) `thenRn` \ maybe_found ->
1048 | hi_boot_file -> readIface mod (hi_file locn ++ "-hi-boot")
1049 | otherwise -> readIface mod (hi_file locn)
1052 other -> traceRn (ptext SLIT("...not found")) `thenRn_`
1053 returnRn (Left (noIfaceErr mod_name hi_boot_file))
1056 trace_msg = sep [hsep [ptext SLIT("Reading"),
1057 if hi_boot_file then ptext SLIT("[boot]") else empty,
1058 ptext SLIT("interface for"),
1059 ppr mod_name <> semi],
1060 nest 4 (ptext SLIT("reason:") <+> doc_str)]
1063 @readIface@ tries just the one file.
1066 readIface :: Module -> String -> RnM d (Either Message (Module, ParsedIface))
1067 -- Nothing <=> file not found, or unreadable, or illegible
1068 -- Just x <=> successfully found and parsed
1069 readIface wanted_mod file_path
1070 = traceRn (ptext SLIT("...reading from") <+> text file_path) `thenRn_`
1071 ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
1074 case parseIface contents
1075 PState{ bol = 0#, atbol = 1#,
1078 loc = mkSrcLoc (mkFastString file_path) 1 } of
1079 POk _ (PIface iface) ->
1080 warnCheckRn (wanted_mod == read_mod)
1081 (hiModuleNameMismatchWarn wanted_mod read_mod) `thenRn_`
1082 returnRn (Right (wanted_mod, iface))
1084 read_mod = pi_mod iface
1086 PFailed err -> bale_out err
1087 parse_result -> bale_out empty
1088 -- This last case can happen if the interface file is (say) empty
1089 -- in which case the parser thinks it looks like an IdInfo or
1090 -- something like that. Just an artefact of the fact that the
1091 -- parser is used for several purposes at once.
1093 Left io_err -> bale_out (text (show io_err))
1095 bale_out err = returnRn (Left (badIfaceFile file_path err))
1098 %*********************************************************
1102 %*********************************************************
1105 noIfaceErr mod_name boot_file
1106 = ptext SLIT("Could not find interface file for") <+> quotes (ppr mod_name)
1107 -- We used to print the search path, but we can't do that
1108 -- now, becuase it's hidden inside the finder.
1109 -- Maybe the finder should expose more functions.
1111 badIfaceFile file err
1112 = vcat [ptext SLIT("Bad interface file:") <+> text file,
1116 = vcat [ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name),
1117 ptext SLIT("from module") <+> quotes (ppr (nameModule name))
1122 "Compiler tried to import decl from interface file with same name as module."),
1124 "(possible cause: module name clashes with interface file already in scope.)")
1126 hsep [ptext SLIT("name:"), quotes (ppr name)]
1128 warnRedundantSourceImport mod_name
1129 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
1130 <+> quotes (ppr mod_name)
1132 hiModuleNameMismatchWarn :: Module -> ModuleName -> Message
1133 hiModuleNameMismatchWarn requested_mod read_mod =
1134 hsep [ ptext SLIT("Something is amiss; requested module name")
1135 , ppr (moduleName requested_mod)
1136 , ptext SLIT("differs from name found in the interface file")