2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[RnIfaces]{Cacheing and Renaming of Interfaces}
12 slurpImpDecls, closeDecls,
14 RecompileRequired, outOfDate, upToDate, recompileRequired
18 #include "HsVersions.h"
20 import CmdLineOpts ( opt_IgnoreIfacePragmas, opt_NoPruneDecls )
22 import HsSyn ( HsDecl(..), Sig(..), TyClDecl(..), ConDecl(..), ConDetails(..),
23 InstDecl(..), HsType(..), hsTyVarNames, getBangType
25 import HsImpExp ( ImportDecl(..) )
26 import RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl )
27 import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl,
28 extractHsTyNames, extractHsCtxtTyNames,
29 tyClDeclFVs, ruleDeclFVs, instDeclFVs
31 import RnHiFiles ( tryLoadInterface, loadHomeInterface,
34 import RnSource ( rnTyClDecl, rnInstDecl, rnIfaceRuleDecl )
38 import Type ( namesOfType )
39 import TyCon ( isSynTyCon, getSynTyConDefn )
40 import Name ( Name {-instance NamedThing-}, nameOccName,
41 nameModule, isLocalName, nameUnique,
44 import Name ( elemNameEnv, delFromNameEnv )
45 import Module ( Module, ModuleEnv,
46 moduleName, isHomeModule,
47 ModuleName, WhereFrom(..),
49 extendModuleEnv_C, foldModuleEnv, lookupModuleEnv,
50 elemModuleSet, extendModuleSet
53 import PrelInfo ( wiredInThingEnv, fractionalClassKeys )
54 import TysWiredIn ( doubleTyCon )
55 import Maybes ( orElse )
59 import Util ( sortLt )
63 %*********************************************************
65 \subsection{Keeping track of what we've slurped, and version numbers}
67 %*********************************************************
69 mkImportInof figures out what the ``usage information'' for this
70 moudule is; that is, what it must record in its interface file as the
73 We produce a line for every module B below the module, A, currently being
76 to record the fact that A does import B indireclty. This is used to decide
77 to look to look for B.hi rather than B.hi-boot when compiling a module that
78 imports A. This line says that A imports B, but uses nothing in it.
79 So we'll get an early bale-out when compiling A if B's version changes.
82 mkImportInfo :: ModuleName -- Name of this module
83 -> [ImportDecl n] -- The import decls
84 -> RnMG [ImportVersion Name]
86 mkImportInfo this_mod imports
87 = getIfacesRn `thenRn` \ ifaces ->
88 getHomeIfaceTableRn `thenRn` \ hit ->
90 (imp_pkg_mods, imp_home_names) = iVSlurp ifaces
93 import_all_mods :: [ModuleName]
94 -- Modules where we imported all the names
95 -- (apart from hiding some, perhaps)
96 import_all_mods = [ m | ImportDecl m _ _ _ imp_list _ <- imports,
99 import_all (Just (False, _)) = False -- Imports are specified explicitly
100 import_all other = True -- Everything is imported
102 -- mv_map groups together all the things imported and used
103 -- from a particular module in this package
104 -- We use a finite map because we want the domain
105 mv_map :: ModuleEnv [Name]
106 mv_map = foldNameSet add_mv emptyModuleEnv imp_home_names
107 add_mv name mv_map = extendModuleEnv_C add_item mv_map mod [name]
109 mod = nameModule name
110 add_item names _ = name:names
112 -- In our usage list we record
113 -- a) Specifically: Detailed version info for imports from modules in this package
114 -- Gotten from iVSlurp plus import_all_mods
116 -- b) Everything: Just the module version for imports from modules in other packages
117 -- Gotten from iVSlurp plus import_all_mods
119 -- c) NothingAtAll: The name only of modules, Baz, in this package that are 'below' us,
120 -- but which we didn't need at all (this is needed only to decide whether
121 -- to open Baz.hi or Baz.hi-boot higher up the tree).
122 -- This happens when a module, Foo, that we explicitly imported has
123 -- 'import Baz' in its interface file, recording that Baz is below
124 -- Foo in the module dependency hierarchy. We want to propagate this info.
125 -- These modules are in a combination of HIT/PIT and iImpModInfo
127 -- d) NothingAtAll: The name only of all orphan modules we know of (this is needed
128 -- so that anyone who imports us can find the orphan modules)
129 -- These modules are in a combination of HIT/PIT and iImpModInfo
131 import_info0 = foldModuleEnv mk_imp_info [] pit
132 import_info1 = foldModuleEnv mk_imp_info import_info0 hit
133 import_info = [ (mod_name, orphans, is_boot, NothingAtAll)
134 | (mod_name, (orphans, is_boot)) <- fmToList (iImpModInfo ifaces) ] ++
137 mk_imp_info :: ModIface -> [ImportVersion Name] -> [ImportVersion Name]
138 mk_imp_info iface so_far
140 | Just ns <- lookupModuleEnv mv_map mod -- Case (a)
141 = go_for_it (Specifically mod_vers maybe_export_vers
142 (mk_import_items ns) rules_vers)
144 | mod `elemModuleSet` imp_pkg_mods -- Case (b)
145 = go_for_it (Everything mod_vers)
147 | import_all_mod -- Case (a) and (b); the import-all part
148 = if is_home_pkg_mod then
149 go_for_it (Specifically mod_vers (Just export_vers) [] rules_vers)
151 go_for_it (Everything mod_vers)
153 | is_home_pkg_mod || has_orphans -- Case (c) or (d)
154 = go_for_it NothingAtAll
158 go_for_it exports = (mod_name, has_orphans, mi_boot iface, exports) : so_far
160 mod = mi_module iface
161 mod_name = moduleName mod
162 is_home_pkg_mod = isHomeModule mod
163 version_info = mi_version iface
164 version_env = vers_decls version_info
165 mod_vers = vers_module version_info
166 rules_vers = vers_rules version_info
167 export_vers = vers_exports version_info
168 import_all_mod = mod_name `elem` import_all_mods
169 has_orphans = mi_orphan iface
171 -- The sort is to put them into canonical order
172 mk_import_items ns = [(n,v) | n <- sortLt lt_occ ns,
173 let v = lookupNameEnv version_env n `orElse`
174 pprPanic "mk_whats_imported" (ppr n)
177 lt_occ n1 n2 = nameOccName n1 < nameOccName n2
179 maybe_export_vers | import_all_mod = Just (vers_exports version_info)
180 | otherwise = Nothing
185 %*********************************************************
187 \subsection{Slurping declarations}
189 %*********************************************************
192 -------------------------------------------------------
193 slurpImpDecls source_fvs
194 = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_`
196 -- The current slurped-set records all local things
197 slurpSourceRefs source_fvs `thenRn` \ (decls, needed) ->
199 -- Then get everything else
200 closeDecls decls needed
203 -------------------------------------------------------
204 slurpSourceRefs :: FreeVars -- Variables referenced in source
205 -> RnMG ([RenamedHsDecl],
206 FreeVars) -- Un-satisfied needs
207 -- The declaration (and hence home module) of each gate has
208 -- already been loaded
210 slurpSourceRefs source_fvs
211 = go_outer [] -- Accumulating decls
212 emptyFVs -- Unsatisfied needs
213 emptyFVs -- Accumulating gates
214 (nameSetToList source_fvs) -- Things whose defn hasn't been loaded yet
216 -- The outer loop repeatedly slurps the decls for the current gates
217 -- and the instance decls
219 -- The outer loop is needed because consider
221 go_outer decls fvs all_gates []
222 = returnRn (decls, fvs)
224 go_outer decls fvs all_gates refs -- refs are not necessarily slurped yet
225 = traceRn (text "go_outer" <+> ppr refs) `thenRn_`
226 foldlRn go_inner (decls, fvs, emptyFVs) refs `thenRn` \ (decls1, fvs1, gates1) ->
227 getImportedInstDecls (all_gates `plusFV` gates1) `thenRn` \ inst_decls ->
228 rnIfaceInstDecls decls1 fvs1 gates1 inst_decls `thenRn` \ (decls2, fvs2, gates2) ->
229 go_outer decls2 fvs2 (all_gates `plusFV` gates2)
230 (nameSetToList (gates2 `minusNameSet` all_gates))
231 -- Knock out the all_gates because even if we don't slurp any new
232 -- decls we can get some apparently-new gates from wired-in names
234 go_inner (decls, fvs, gates) wanted_name
235 = importDecl wanted_name `thenRn` \ import_result ->
236 case import_result of
237 AlreadySlurped -> returnRn (decls, fvs, gates)
238 InTypeEnv ty_thing -> returnRn (decls, fvs, gates `plusFV` getWiredInGates ty_thing)
240 HereItIs decl -> rnIfaceTyClDecl decl `thenRn` \ (new_decl, fvs1) ->
241 returnRn (TyClD new_decl : decls,
243 gates `plusFV` getGates source_fvs new_decl)
248 -------------------------------------------------------
249 -- closeDecls keeps going until the free-var set is empty
250 closeDecls decls needed
251 | not (isEmptyFVs needed)
252 = slurpDecls decls needed `thenRn` \ (decls1, needed1) ->
253 closeDecls decls1 needed1
256 = getImportedRules `thenRn` \ rule_decls ->
258 [] -> returnRn decls -- No new rules, so we are done
259 other -> rnIfaceDecls rnIfaceRuleDecl rule_decls `thenRn` \ rule_decls' ->
261 rule_fvs = plusFVs (map ruleDeclFVs rule_decls')
263 traceRn (text "closeRules" <+> ppr rule_decls' $$ fsep (map ppr (nameSetToList rule_fvs))) `thenRn_`
264 closeDecls (map RuleD rule_decls' ++ decls) rule_fvs
268 -------------------------------------------------------
269 -- Augment decls with any decls needed by needed.
270 -- Return also free vars of the new decls (only)
271 slurpDecls decls needed
272 = go decls emptyFVs (nameSetToList needed)
274 go decls fvs [] = returnRn (decls, fvs)
275 go decls fvs (ref:refs) = slurpDecl decls fvs ref `thenRn` \ (decls1, fvs1) ->
278 -------------------------------------------------------
279 slurpDecl decls fvs wanted_name
280 = importDecl wanted_name `thenRn` \ import_result ->
281 case import_result of
282 -- Found a declaration... rename it
283 HereItIs decl -> rnIfaceTyClDecl decl `thenRn` \ (new_decl, fvs1) ->
284 returnRn (TyClD new_decl:decls, fvs1 `plusFV` fvs)
286 -- No declaration... (wired in thing, or deferred, or already slurped)
287 other -> returnRn (decls, fvs)
290 -------------------------------------------------------
291 rnIfaceDecls rn decls = mapRn (rnIfaceDecl rn) decls
292 rnIfaceDecl rn (mod, decl) = initIfaceRnMS mod (rn decl)
294 rnIfaceInstDecls decls fvs gates inst_decls
295 = rnIfaceDecls rnInstDecl inst_decls `thenRn` \ inst_decls' ->
296 returnRn (map InstD inst_decls' ++ decls,
297 fvs `plusFV` plusFVs (map instDeclFVs inst_decls'),
298 gates `plusFV` plusFVs (map getInstDeclGates inst_decls'))
300 rnIfaceTyClDecl (mod, decl) = initIfaceRnMS mod (rnTyClDecl decl) `thenRn` \ decl' ->
301 returnRn (decl', tyClDeclFVs decl')
306 recordSlurp ifaces@(Ifaces { iDecls = (decls_map, n_slurped),
307 iSlurp = slurped_names,
308 iVSlurp = (imp_mods, imp_names) })
310 = ASSERT2( not (isLocalName (availName avail)), ppr avail )
311 ifaces { iDecls = (decls_map', n_slurped+1),
312 iSlurp = new_slurped_names,
313 iVSlurp = new_vslurp }
315 decls_map' = foldl delFromNameEnv decls_map (availNames avail)
316 main_name = availName avail
317 mod = nameModule main_name
318 new_slurped_names = addAvailToNameSet slurped_names avail
319 new_vslurp | isHomeModule mod = (imp_mods, addOneToNameSet imp_names main_name)
320 | otherwise = (extendModuleSet imp_mods mod, imp_names)
322 recordLocalSlurps new_names
323 = getIfacesRn `thenRn` \ ifaces ->
324 setIfacesRn (ifaces { iSlurp = iSlurp ifaces `unionNameSets` new_names })
329 %*********************************************************
331 \subsection{Extracting the `gates'}
333 %*********************************************************
337 We want to avoid sucking in too many instance declarations.
338 An instance decl is only useful if the types and classes mentioned in
339 its 'head' are all available in the program being compiled. E.g.
341 instance (..) => C (T1 a) (T2 b) where ...
343 is only useful if C, T1 and T2 are all "available". So we keep
344 instance decls that have been parsed from .hi files, but not yet
345 slurped in, in a pool called the 'gated instance pool'.
346 Each has its set of 'gates': {C, T1, T2} in the above example.
348 More precisely, the gates of a module are the types and classes
349 that are mentioned in:
352 b) the type of an Id that's mentioned in the source code
353 [includes constructors and selectors]
354 c) the RHS of a type synonym that is a gate
355 d) the superclasses of a class that is a gate
356 e) the context of an instance decl that is slurped in
358 We slurp in an instance decl from the gated instance pool iff
360 all its gates are either in the gates of the module,
361 or are a previously-loaded class.
363 The latter constraint is because there might have been an instance
364 decl slurped in during an earlier compilation, like this:
366 instance Foo a => Baz (Maybe a) where ...
368 In the module being compiled we might need (Baz (Maybe T)), where T
369 is defined in this module, and hence we need (Foo T). So @Foo@ becomes
370 a gate. But there's no way to 'see' that, so we simply treat all
371 previously-loaded classes as gates.
373 Consructors and class operations
374 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
375 When we import a declaration like
377 data T = T1 Wibble | T2 Wobble
379 we don't want to treat @Wibble@ and @Wobble@ as gates {\em unless}
380 @T1@, @T2@ respectively are mentioned by the user program. If only
381 @T@ is mentioned we want only @T@ to be a gate; that way we don't suck
382 in useless instance decls for (say) @Eq Wibble@, when they can't
385 And that's just what (b) says: we only treat T1's type as a gate if
386 T1 is mentioned. getGates, which deals with decls we are slurping in,
387 has to be a bit careful, because a mention of T1 will slurp in T's whole
390 -----------------------------
391 @getGates@ takes a newly imported (and renamed) decl, and the free
392 vars of the source program, and extracts from the decl the gate names.
395 getGates :: FreeVars -- Things mentioned in the source program
399 getGates source_fvs decl
400 = get_gates (\n -> n `elemNameSet` source_fvs) decl
402 get_gates is_used (IfaceSig {tcdType = ty}) = extractHsTyNames ty
404 get_gates is_used (ClassDecl { tcdCtxt = ctxt, tcdName = cls, tcdTyVars = tvs, tcdSigs = sigs})
405 = (delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) sigs)
407 `addOneToNameSet` cls)
408 `plusFV` maybe_double
410 get (ClassOpSig n _ ty _)
411 | is_used n = extractHsTyNames ty
412 | otherwise = emptyFVs
414 -- If we load any numeric class that doesn't have
415 -- Int as an instance, add Double to the gates.
416 -- This takes account of the fact that Double might be needed for
417 -- defaulting, but we don't want to load Double (and all its baggage)
418 -- if the more exotic classes aren't used at all.
419 maybe_double | nameUnique cls `elem` fractionalClassKeys
420 = unitFV (getName doubleTyCon)
424 get_gates is_used (TySynonym {tcdTyVars = tvs, tcdSynRhs = ty})
425 = delListFromNameSet (extractHsTyNames ty) (hsTyVarNames tvs)
426 -- A type synonym type constructor isn't a "gate" for instance decls
428 get_gates is_used (TyData {tcdCtxt = ctxt, tcdName = tycon, tcdTyVars = tvs, tcdCons = cons})
429 = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) cons)
431 `addOneToNameSet` tycon
433 get (ConDecl n _ tvs ctxt details _)
435 -- If the constructor is method, get fvs from all its fields
436 = delListFromNameSet (get_details details `plusFV`
437 extractHsCtxtTyNames ctxt)
439 get (ConDecl n _ tvs ctxt (RecCon fields) _)
440 -- Even if the constructor isn't mentioned, the fields
441 -- might be, as selectors. They can't mention existentially
442 -- bound tyvars (typechecker checks for that) so no need for
443 -- the deleteListFromNameSet part
444 = foldr (plusFV . get_field) emptyFVs fields
446 get other_con = emptyFVs
448 get_details (VanillaCon tys) = plusFVs (map get_bang tys)
449 get_details (InfixCon t1 t2) = get_bang t1 `plusFV` get_bang t2
450 get_details (RecCon fields) = plusFVs [get_bang t | (_, t) <- fields]
452 get_field (fs,t) | any is_used fs = get_bang t
453 | otherwise = emptyFVs
455 get_bang bty = extractHsTyNames (getBangType bty)
458 @getWiredInGates@ is just like @getGates@, but it sees a previously-loaded
459 thing rather than a declaration.
462 getWiredInGates :: TyThing -> FreeVars
463 -- The TyThing is one that we already have in our type environment, either
464 -- a) because the TyCon or Id is wired in, or
465 -- b) from a previous compile
466 -- Either way, we might have instance decls in the (persistent) collection
467 -- of parsed-but-not-slurped instance decls that should be slurped in.
468 -- This might be the first module that mentions both the type and the class
469 -- for that instance decl, even though both the type and the class were
470 -- mentioned in other modules, and hence are in the type environment
472 getWiredInGates (AnId the_id) = namesOfType (idType the_id)
473 getWiredInGates (AClass cl) = emptyFVs -- The superclasses must also be previously
474 -- loaded, and hence are automatically gates
475 getWiredInGates (ATyCon tc)
476 | isSynTyCon tc = delListFromNameSet (namesOfType ty) (map getName tyvars)
477 | otherwise = unitFV (getName tc)
479 (tyvars,ty) = getSynTyConDefn tc
481 getInstDeclGates (InstDecl inst_ty _ _ _ _) = extractHsTyNames inst_ty
485 getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameInstDecl)]
486 getImportedInstDecls gates
487 = -- First, load any orphan-instance modules that aren't aready loaded
488 -- Orphan-instance modules are recorded in the module dependecnies
489 getIfacesRn `thenRn` \ ifaces ->
492 [mod | (mod, (True, _)) <- fmToList (iImpModInfo ifaces)]
494 loadOrphanModules orphan_mods `thenRn_`
496 -- Now we're ready to grab the instance declarations
497 -- Find the un-gated ones and return them,
498 -- removing them from the bag kept in Ifaces
499 getIfacesRn `thenRn` \ ifaces ->
500 getTypeEnvRn `thenRn` \ lookup ->
502 (decls, new_insts) = selectGated gates lookup (iInsts ifaces)
504 setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_`
506 traceRn (sep [text "getImportedInstDecls:",
507 nest 4 (fsep (map ppr gate_list)),
508 text "Slurped" <+> int (length decls) <+> text "instance declarations",
509 nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_`
512 gate_list = nameSetToList gates
514 ppr_brief_inst_decl (mod, InstDecl inst_ty _ _ _ _)
516 HsForAllTy _ _ tau -> ppr tau
519 getImportedRules :: RnMG [(Module,RdrNameRuleDecl)]
521 | opt_IgnoreIfacePragmas = returnRn []
523 = getIfacesRn `thenRn` \ ifaces ->
524 getTypeEnvRn `thenRn` \ lookup ->
526 gates = iSlurp ifaces -- Anything at all that's been slurped
527 rules = iRules ifaces
528 (decls, new_rules) = selectGated gates lookup rules
533 setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
534 traceRn (sep [text "getImportedRules:",
535 text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
538 selectGated gates lookup (decl_bag, n_slurped)
539 -- Select only those decls whose gates are *all* in 'gates'
540 -- or are a class in 'lookup'
542 | opt_NoPruneDecls -- Just to try the effect of not gating at all
544 decls = foldrBag (\ (_,d) ds -> d:ds) [] decl_bag -- Grab them all
546 (decls, (emptyBag, n_slurped + length decls))
550 = case foldrBag select ([], emptyBag) decl_bag of
551 (decls, new_bag) -> (decls, (new_bag, n_slurped + length decls))
553 available n = n `elemNameSet` gates
554 || case lookup n of { Just (AClass c) -> True; other -> False }
556 select (reqd, decl) (yes, no)
557 | all available reqd = (decl:yes, no)
558 | otherwise = (yes, (reqd,decl) `consBag` no)
562 %*********************************************************
564 \subsection{Getting in a declaration}
566 %*********************************************************
569 importDecl :: Name -> RnMG ImportDeclResult
571 data ImportDeclResult
574 | HereItIs (Module, RdrNameTyClDecl)
577 = -- STEP 1: Check if we've slurped it in while compiling this module
578 getIfacesRn `thenRn` \ ifaces ->
579 if name `elemNameSet` iSlurp ifaces then
580 returnRn AlreadySlurped
583 -- STEP 2: Check if it's already in the type environment
584 getTypeEnvRn `thenRn` \ lookup ->
585 case lookup name of {
586 Just ty_thing | name `elemNameEnv` wiredInThingEnv
587 -> -- When we find a wired-in name we must load its home
588 -- module so that we find any instance decls lurking therein
589 loadHomeInterface wi_doc name `thenRn_`
590 returnRn (InTypeEnv ty_thing)
593 -> returnRn (InTypeEnv ty_thing) ;
597 -- STEP 3: OK, we have to slurp it in from an interface file
598 -- First load the interface file
599 traceRn nd_doc `thenRn_`
600 loadHomeInterface nd_doc name `thenRn_`
601 getIfacesRn `thenRn` \ ifaces ->
603 -- STEP 4: Get the declaration out
605 (decls_map, _) = iDecls ifaces
607 case lookupNameEnv decls_map name of
609 -> setIfacesRn (recordSlurp ifaces avail) `thenRn_`
610 returnRn (HereItIs decl)
613 -> addErrRn (getDeclErr name) `thenRn_`
614 returnRn AlreadySlurped
617 wi_doc = ptext SLIT("need home module for wired in thing") <+> ppr name
618 nd_doc = ptext SLIT("need decl for") <+> ppr name
623 %********************************************************
625 \subsection{Checking usage information}
627 %********************************************************
629 @recompileRequired@ is called from the HscMain. It checks whether
630 a recompilation is required. It needs access to the persistent state,
631 finder, etc, because it may have to load lots of interface files to
632 check their versions.
635 type RecompileRequired = Bool
636 upToDate = False -- Recompile not required
637 outOfDate = True -- Recompile required
639 recompileRequired :: FilePath -- Only needed for debug msgs
640 -> ModIface -- Old interface
641 -> RnMG RecompileRequired
642 recompileRequired iface_path iface
643 = traceHiDiffsRn (text "Considering whether compilation is required for" <+> text iface_path <> colon) `thenRn_`
645 -- Source code unchanged and no errors yet... carry on
646 checkList [checkModUsage u | u <- mi_usages iface]
648 checkList :: [RnMG RecompileRequired] -> RnMG RecompileRequired
649 checkList [] = returnRn upToDate
650 checkList (check:checks) = check `thenRn` \ recompile ->
658 checkModUsage :: ImportVersion Name -> RnMG RecompileRequired
659 -- Given the usage information extracted from the old
660 -- M.hi file for the module being compiled, figure out
661 -- whether M needs to be recompiled.
663 checkModUsage (mod_name, _, _, NothingAtAll)
664 -- If CurrentModule.hi contains
666 -- then that simply records that Foo lies below CurrentModule in the
667 -- hierarchy, but CurrentModule doesn't depend in any way on Foo.
668 -- In this case we don't even want to open Foo's interface.
669 = up_to_date (ptext SLIT("Nothing used from:") <+> ppr mod_name)
671 checkModUsage (mod_name, _, is_boot, whats_imported)
672 = -- Load the imported interface is possible
673 -- We use tryLoadInterface, because failure is not an error
674 -- (might just be that the old .hi file for this module is out of date)
675 -- We use ImportByUser/ImportByUserSource as the 'from' flag,
676 -- a) because we need to know whether to load the .hi-boot file
677 -- b) because loadInterface things matters are amiss if we
678 -- ImportBySystem an interface it knows nothing about
680 doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
681 from | is_boot = ImportByUserSource
682 | otherwise = ImportByUser
684 tryLoadInterface doc_str mod_name from `thenRn` \ (iface, maybe_err) ->
687 Just err -> out_of_date (sep [ptext SLIT("Can't find version number for module"),
689 -- Couldn't find or parse a module mentioned in the
690 -- old interface file. Don't complain -- it might just be that
691 -- the current module doesn't need that import and it's been deleted
695 new_vers = mi_version iface
696 new_decl_vers = vers_decls new_vers
698 case whats_imported of { -- NothingAtAll dealt with earlier
700 Everything old_mod_vers -> checkModuleVersion old_mod_vers new_vers `thenRn` \ recompile ->
702 out_of_date (ptext SLIT("...and I needed the whole module"))
706 Specifically old_mod_vers maybe_old_export_vers old_decl_vers old_rule_vers ->
709 checkModuleVersion old_mod_vers new_vers `thenRn` \ recompile ->
710 if not recompile then
715 if checkExportList maybe_old_export_vers new_vers then
716 out_of_date (ptext SLIT("Export list changed"))
720 if old_rule_vers /= vers_rules new_vers then
721 out_of_date (ptext SLIT("Rules changed"))
724 -- CHECK ITEMS ONE BY ONE
725 checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenRn` \ recompile ->
727 returnRn outOfDate -- This one failed, so just bail out now
729 up_to_date (ptext SLIT("...but the bits I use haven't."))
733 ------------------------
734 checkModuleVersion old_mod_vers new_vers
735 | vers_module new_vers == old_mod_vers
736 = up_to_date (ptext SLIT("Module version unchanged"))
739 = out_of_date (ptext SLIT("Module version has changed"))
741 ------------------------
742 checkExportList Nothing new_vers = upToDate
743 checkExportList (Just v) new_vers = v /= vers_exports new_vers
745 ------------------------
746 checkEntityUsage new_vers (name,old_vers)
747 = case lookupNameEnv new_vers name of
749 Nothing -> -- We used it before, but it ain't there now
750 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
752 Just new_vers -- It's there, but is it up to date?
753 | new_vers == old_vers -> returnRn upToDate
754 | otherwise -> out_of_date (sep [ptext SLIT("Out of date:"), ppr name])
756 up_to_date msg = traceHiDiffsRn msg `thenRn_` returnRn upToDate
757 out_of_date msg = traceHiDiffsRn msg `thenRn_` returnRn outOfDate
761 %*********************************************************
765 %*********************************************************
769 = vcat [ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name),
770 ptext SLIT("from module") <+> quotes (ppr (nameModule name))