2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[RnIfaces]{Cacheing and Renaming of Interfaces}
9 getImportedInstDecls, getImportedRules,
10 lookupFixity, loadHomeInterface,
11 importDecl, recordSlurp,
12 getImportVersions, getSlurped,
16 getDeclBinders, getDeclSysBinders,
17 removeContext -- removeContext probably belongs somewhere else
20 #include "HsVersions.h"
22 import CmdLineOpts ( opt_NoPruneDecls, opt_IgnoreIfacePragmas )
23 import HsSyn ( HsDecl(..), TyClDecl(..), InstDecl(..), IfaceSig(..),
24 HsType(..), ConDecl(..), IE(..), ConDetails(..), Sig(..),
25 ForeignDecl(..), ForKind(..), isDynamicExtName,
26 FixitySig(..), RuleDecl(..),
27 isClassOpSig, Deprecation(..)
29 import BasicTypes ( Version, NewOrData(..), defaultFixity )
30 import RdrHsSyn ( RdrNameHsDecl, RdrNameInstDecl, RdrNameTyClDecl, RdrNameRuleDecl,
31 extractHsTyRdrNames, RdrNameDeprecation
33 import RnEnv ( mkImportedGlobalName, newImportedBinder, mkImportedGlobalFromRdrName,
34 lookupOccRn, lookupImplicitOccRn,
36 availName, availNames, addAvailToNameSet, addSysAvails,
40 import RnHsSyn ( RenamedHsDecl, RenamedDeprecation )
41 import ParseIface ( parseIface, IfaceStuff(..) )
43 import FiniteMap ( FiniteMap, sizeFM, emptyFM, delFromFM, listToFM,
44 lookupFM, addToFM, addToFM_C, addListToFM,
45 fmToList, elemFM, foldFM
47 import Name ( Name {-instance NamedThing-},
48 nameModule, isLocallyDefined,
49 isWiredInName, nameUnique, NamedThing(..)
51 import Module ( Module, moduleString, pprModule,
52 mkVanillaModule, pprModuleName,
53 moduleUserString, moduleName, isLibModule,
54 ModuleName, WhereFrom(..),
56 import RdrName ( RdrName, rdrNameOcc )
59 import SrcLoc ( mkSrcLoc, SrcLoc )
60 import PrelMods ( pREL_GHC )
61 import PrelInfo ( cCallishTyKeys )
63 import Maybes ( MaybeErr(..), maybeToBool, orElse )
64 import ListSetOps ( unionLists )
66 import Unique ( Unique )
67 import StringBuffer ( StringBuffer, hGetStringBuffer )
68 import FastString ( mkFastString )
69 import ErrUtils ( Message )
73 import IO ( isDoesNotExistError )
78 %*********************************************************
80 \subsection{Loading a new interface file}
82 %*********************************************************
85 loadHomeInterface :: SDoc -> Name -> RnM d Ifaces
86 loadHomeInterface doc_str name
87 = loadInterface doc_str (moduleName (nameModule name)) ImportBySystem `thenRn` \ (_, ifaces) ->
90 loadOrphanModules :: [ModuleName] -> RnM d ()
91 loadOrphanModules mods
92 | null mods = returnRn ()
93 | otherwise = traceRn (text "Loading orphan modules:" <+> fsep (map pprModuleName mods)) `thenRn_`
94 mapRn_ load mods `thenRn_`
97 load mod = loadInterface (pprModuleName mod <+> ptext SLIT("is a orphan-instance module")) mod ImportBySystem
99 loadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d (Module, Ifaces)
100 loadInterface doc_str mod_name from
101 = getIfacesRn `thenRn` \ ifaces ->
103 mod_map = iImpModInfo ifaces
104 mod_info = lookupFM mod_map mod_name
105 below_me = case mod_info of
107 Just (_, _, is_boot, _) -> not is_boot
110 -- Issue a warning for a redundant {- SOURCE -} import
111 -- It's redundant if the moduld is in the iImpModInfo at all,
112 -- because we arrange to read all the ordinary imports before
113 -- any of the {- SOURCE -} imports
114 warnCheckRn (not (below_me && case from of {ImportByUserSource -> True; other -> False}))
115 (warnRedundantSourceImport mod_name) `thenRn_`
117 -- CHECK WHETHER WE HAVE IT ALREADY
119 Just (_, _, _, Just (load_mod, _))
120 -> -- We're read it already so don't re-read it
121 returnRn (load_mod, ifaces) ;
125 -- READ THE MODULE IN
126 findAndReadIface doc_str mod_name from below_me
127 `thenRn` \ (hi_boot_read, read_result) ->
128 case read_result of {
129 Nothing -> -- Not found, so add an empty export env to the Ifaces map
130 -- so that we don't look again
132 mod = mkVanillaModule mod_name
133 new_mod_map = addToFM mod_map mod_name (0, False, False, Just (mod, []))
134 new_ifaces = ifaces { iImpModInfo = new_mod_map }
136 setIfacesRn new_ifaces `thenRn_`
137 failWithRn (mod, new_ifaces) (noIfaceErr mod hi_boot_read) ;
142 -- LOAD IT INTO Ifaces
144 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
145 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
146 -- If we do loadExport first the wrong info gets into the cache (unless we
147 -- explicitly tag each export which seems a bit of a bore)
149 getModuleRn `thenRn` \ this_mod_nm ->
151 rd_decls = pi_decls iface
153 foldlRn (loadDecl mod) (iDecls ifaces) rd_decls `thenRn` \ new_decls ->
154 foldlRn (loadInstDecl mod) (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
155 (if opt_IgnoreIfacePragmas
156 then returnRn emptyBag
157 else foldlRn (loadRule mod) (iRules ifaces) (pi_rules iface)) `thenRn` \ new_rules ->
158 (if opt_IgnoreIfacePragmas
159 then returnRn emptyNameEnv
160 else foldlRn (loadDeprec mod) (iDeprecs ifaces) (pi_deprecs iface)) `thenRn` \ new_deprecs ->
161 foldlRn (loadFixDecl mod_name) (iFixes ifaces) rd_decls `thenRn` \ new_fixities ->
162 mapRn (loadExport this_mod_nm) (pi_exports iface) `thenRn` \ avails_s ->
164 -- For an explicit user import, add to mod_map info about
165 -- the things the imported module depends on, extracted
166 -- from its usage info.
167 mod_map1 = case from of
168 ImportByUser -> addModDeps mod mod_map (pi_usages iface)
171 -- Now add info about this module
172 mod_map2 = addToFM mod_map1 mod_name mod_details
173 mod_details = (pi_mod iface, pi_orphan iface, hi_boot_read, Just (mod, concat avails_s))
175 new_ifaces = ifaces { iImpModInfo = mod_map2,
177 iFixes = new_fixities,
180 iDeprecs = new_deprecs }
182 setIfacesRn new_ifaces `thenRn_`
183 returnRn (mod, new_ifaces)
186 addModDeps :: Module -> ImportedModuleInfo
187 -> [ImportVersion a] -> ImportedModuleInfo
188 addModDeps mod mod_deps new_deps
189 = foldr add mod_deps new_deps
191 is_lib = isLibModule mod -- Don't record dependencies when importing a library module
192 add (imp_mod, version, has_orphans, is_boot, _) deps
193 | is_lib && not has_orphans = deps
194 | otherwise = addToFM_C combine deps imp_mod (version, has_orphans, is_boot, Nothing)
195 -- Record dependencies for modules that are
196 -- either are dependent via a non-library module
197 -- or contain orphan rules or instance decls
199 combine old@(_, _, old_is_boot, cts) new
200 | maybeToBool cts || not old_is_boot = old -- Keep the old info if it's already loaded
201 -- or if it's a non-boot pending load
202 | otherwise = new -- Otherwise pick new info
204 loadExport :: ModuleName -> ExportItem -> RnM d [AvailInfo]
205 loadExport this_mod (mod, entities)
206 | mod == this_mod = returnRn []
207 -- If the module exports anything defined in this module, just ignore it.
208 -- Reason: otherwise it looks as if there are two local definition sites
209 -- for the thing, and an error gets reported. Easiest thing is just to
210 -- filter them out up front. This situation only arises if a module
211 -- imports itself, or another module that imported it. (Necessarily,
212 -- this invoves a loop.) Consequence: if you say
217 -- module B( AType ) where
218 -- import {-# SOURCE #-} A( AType )
220 -- then you'll get a 'B does not export AType' message. A bit bogus
221 -- but it's a bogus thing to do!
224 = mapRn (load_entity mod) entities
226 new_name mod occ = mkImportedGlobalName mod occ
228 load_entity mod (Avail occ)
229 = new_name mod occ `thenRn` \ name ->
230 returnRn (Avail name)
231 load_entity mod (AvailTC occ occs)
232 = new_name mod occ `thenRn` \ name ->
233 mapRn (new_name mod) occs `thenRn` \ names ->
234 returnRn (AvailTC name names)
237 loadFixDecl :: ModuleName -> FixityEnv
238 -> (Version, RdrNameHsDecl)
240 loadFixDecl mod_name fixity_env (version, FixD sig@(FixitySig rdr_name fixity loc))
241 = -- Ignore the version; when the fixity changes the version of
242 -- its 'host' entity changes, so we don't need a separate version
243 -- number for fixities
244 mkImportedGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
246 new_fixity_env = addToNameEnv fixity_env name (FixitySig name fixity loc)
248 returnRn new_fixity_env
250 -- Ignore the other sorts of decl
251 loadFixDecl mod_name fixity_env other_decl = returnRn fixity_env
255 -> (Version, RdrNameHsDecl)
258 loadDecl mod decls_map (version, decl)
259 = getDeclBinders new_name decl `thenRn` \ maybe_avail ->
260 case maybe_avail of {
261 Nothing -> returnRn decls_map; -- No bindings
264 getDeclSysBinders new_name decl `thenRn` \ sys_bndrs ->
266 full_avail = addSysAvails avail sys_bndrs
267 -- Add the sys-binders to avail. When we import the decl,
268 -- it's full_avail that will get added to the 'already-slurped' set (iSlurp)
269 -- If we miss out sys-binders, we'll read the decl multiple times!
271 main_name = availName avail
272 new_decls_map = foldl add_decl decls_map
273 [ (name, (version, full_avail, name==main_name, (mod, decl')))
274 | name <- availNames full_avail]
275 add_decl decls_map (name, stuff)
276 = WARN( name `elemNameEnv` decls_map, ppr name )
277 addToNameEnv decls_map name stuff
279 returnRn new_decls_map
282 -- newImportedBinder puts into the cache the binder with the
283 -- module information set correctly. When the decl is later renamed,
284 -- the binding site will thereby get the correct module.
285 new_name rdr_name loc = newImportedBinder mod rdr_name
288 If a signature decl is being loaded, and optIgnoreIfacePragmas is on,
289 we toss away unfolding information.
291 Also, if the signature is loaded from a module we're importing from source,
292 we do the same. This is to avoid situations when compiling a pair of mutually
293 recursive modules, peering at unfolding info in the interface file of the other,
294 e.g., you compile A, it looks at B's interface file and may as a result change
295 its interface file. Hence, B is recompiled, maybe changing its interface file,
296 which will the unfolding info used in A to become invalid. Simple way out is to
297 just ignore unfolding info.
299 [Jan 99: I junked the second test above. If we're importing from an hi-boot
300 file there isn't going to *be* any pragma info. Maybe the above comment
301 dates from a time where we picked up a .hi file first if it existed?]
304 SigD (IfaceSig name tp ls loc) | opt_IgnoreIfacePragmas
305 -> SigD (IfaceSig name tp [] loc)
308 loadInstDecl :: Module
311 -> RnM d (Bag GatedDecl)
312 loadInstDecl mod insts decl@(InstDecl inst_ty binds uprags dfun_name src_loc)
314 -- Find out what type constructors and classes are "gates" for the
315 -- instance declaration. If all these "gates" are slurped in then
316 -- we should slurp the instance decl too.
318 -- We *don't* want to count names in the context part as gates, though.
320 -- instance Foo a => Baz (T a) where ...
322 -- Here the gates are Baz and T, but *not* Foo.
324 munged_inst_ty = removeContext inst_ty
325 free_names = extractHsTyRdrNames munged_inst_ty
327 setModuleRn (moduleName mod) $
328 mapRn mkImportedGlobalFromRdrName free_names `thenRn` \ gate_names ->
329 returnRn ((mkNameSet gate_names, (mod, InstD decl)) `consBag` insts)
332 -- In interface files, the instance decls now look like
333 -- forall a. Foo a -> Baz (T a)
334 -- so we have to strip off function argument types as well
335 -- as the bit before the '=>' (which is always empty in interface files)
336 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
337 removeContext ty = removeFuns ty
339 removeFuns (MonoFunTy _ ty) = removeFuns ty
343 loadRule :: Module -> Bag GatedDecl
344 -> RdrNameRuleDecl -> RnM d (Bag GatedDecl)
345 -- "Gate" the rule simply by whether the rule variable is
346 -- needed. We can refine this later.
347 loadRule mod rules decl@(IfaceRuleDecl var body src_loc)
348 = setModuleRn (moduleName mod) $
349 mkImportedGlobalFromRdrName var `thenRn` \ var_name ->
350 returnRn ((unitNameSet var_name, (mod, RuleD decl)) `consBag` rules)
352 -- SUP: TEMPORARY HACK, ignoring module deprecations for now
353 loadDeprec :: Module -> DeprecationEnv -> RdrNameDeprecation -> RnM d DeprecationEnv
354 loadDeprec mod deprec_env (Deprecation (IEModuleContents _) txt)
355 = traceRn (text "module deprecation not yet implemented:" <+> ppr mod <> colon <+> ppr txt) `thenRn_`
357 loadDeprec mod deprec_env (Deprecation ie txt)
358 = setModuleRn (moduleName mod) $
359 mapRn mkImportedGlobalFromRdrName (namesFromIE ie) `thenRn` \ names ->
360 traceRn (text "loaded deprecation(s) for" <+> hcat (punctuate comma (map ppr names)) <> colon <+> ppr txt) `thenRn_`
361 returnRn (extendNameEnv deprec_env (zip names (repeat txt)))
363 namesFromIE :: IE a -> [a]
364 namesFromIE (IEVar n ) = [n]
365 namesFromIE (IEThingAbs n ) = [n]
366 namesFromIE (IEThingAll n ) = [n]
367 namesFromIE (IEThingWith n ns) = n:ns
368 namesFromIE (IEModuleContents _ ) = []
372 %********************************************************
374 \subsection{Loading usage information}
376 %********************************************************
379 checkUpToDate :: ModuleName -> RnMG Bool -- True <=> no need to recompile
380 checkUpToDate mod_name
381 = getIfacesRn `thenRn` \ ifaces ->
382 findAndReadIface doc_str mod_name
384 (error "checkUpToDate") `thenRn` \ (_, read_result) ->
386 -- CHECK WHETHER WE HAVE IT ALREADY
388 Nothing -> -- Old interface file not found, so we'd better bail out
389 traceRn (sep [ptext SLIT("Didnt find old iface"),
390 pprModuleName mod_name]) `thenRn_`
394 -> -- Found it, so now check it
395 checkModUsage (pi_usages iface)
397 -- Only look in current directory, with suffix .hi
398 doc_str = sep [ptext SLIT("need usage info from"), pprModuleName mod_name]
400 checkModUsage [] = returnRn True -- Yes! Everything is up to date!
402 checkModUsage ((mod_name, old_mod_vers, _, _, Specifically []) : rest)
403 -- If CurrentModule.hi contains
405 -- then that simply records that Foo lies below CurrentModule in the
406 -- hierarchy, but CurrentModule doesn't depend in any way on Foo.
407 -- In this case we don't even want to open Foo's interface.
408 = traceRn (ptext SLIT("Nothing used from:") <+> ppr mod_name) `thenRn_`
409 checkModUsage rest -- This one's ok, so check the rest
411 checkModUsage ((mod_name, old_mod_vers, _, _, whats_imported) : rest)
412 = loadInterface doc_str mod_name ImportBySystem `thenRn` \ (mod, ifaces) ->
414 maybe_mod_vers = case lookupFM (iImpModInfo ifaces) mod_name of
415 Just (version, _, _, Just (_, _)) -> Just version
418 case maybe_mod_vers of {
419 Nothing -> -- If we can't find a version number for the old module then
420 -- bail out saying things aren't up to date
421 traceRn (sep [ptext SLIT("Can't find version number for module"),
422 pprModuleName mod_name])
423 `thenRn_` returnRn False ;
427 -- If the module version hasn't changed, just move on
428 if new_mod_vers == old_mod_vers then
429 traceRn (sep [ptext SLIT("Module version unchanged:"), pprModuleName mod_name])
430 `thenRn_` checkModUsage rest
432 traceRn (sep [ptext SLIT("Module version has changed:"), pprModuleName mod_name])
434 -- Module version changed, so check entities inside
436 -- If the usage info wants to say "I imported everything from this module"
437 -- it does so by making whats_imported equal to Everything
438 -- In that case, we must recompile
439 case whats_imported of {
440 Everything -> traceRn (ptext SLIT("...and I needed the whole module")) `thenRn_`
441 returnRn False; -- Bale out
443 Specifically old_local_vers ->
445 -- Non-empty usage list, so check item by item
446 checkEntityUsage mod_name (iDecls ifaces) old_local_vers `thenRn` \ up_to_date ->
448 traceRn (ptext SLIT("...but the bits I use haven't.")) `thenRn_`
449 checkModUsage rest -- This one's ok, so check the rest
451 returnRn False -- This one failed, so just bail out now
454 doc_str = sep [ptext SLIT("need version info for"), pprModuleName mod_name]
457 checkEntityUsage mod decls []
458 = returnRn True -- Yes! All up to date!
460 checkEntityUsage mod decls ((occ_name,old_vers) : rest)
461 = mkImportedGlobalName mod occ_name `thenRn` \ name ->
462 case lookupNameEnv decls name of
464 Nothing -> -- We used it before, but it ain't there now
465 traceRn (sep [ptext SLIT("No longer exported:"), ppr name])
466 `thenRn_` returnRn False
468 Just (new_vers,_,_,_) -- It's there, but is it up to date?
469 | new_vers == old_vers
470 -- Up to date, so check the rest
471 -> checkEntityUsage mod decls rest
474 -- Out of date, so bale out
475 -> traceRn (sep [ptext SLIT("Out of date:"), ppr name]) `thenRn_`
480 %*********************************************************
482 \subsection{Getting in a declaration}
484 %*********************************************************
487 importDecl :: Name -> RnMG (Maybe (Module, RdrNameHsDecl))
488 -- Returns Nothing for
491 -- (c) already slurped
497 = getSlurped `thenRn` \ already_slurped ->
498 if name `elemNameSet` already_slurped then
499 returnRn Nothing -- Already dealt with
501 if isLocallyDefined name then -- Don't bring in decls from
502 -- the renamed module's own interface file
503 addWarnRn (importDeclWarn name) `thenRn_`
506 getNonWiredInDecl name
510 getNonWiredInDecl :: Name -> RnMG (Maybe (Module, RdrNameHsDecl))
511 getNonWiredInDecl needed_name
512 = traceRn doc_str `thenRn_`
513 loadHomeInterface doc_str needed_name `thenRn` \ ifaces ->
514 case lookupNameEnv (iDecls ifaces) needed_name of
516 Just (version,avail,_,decl)
517 -> recordSlurp (Just version) avail `thenRn_`
520 Nothing -- Can happen legitimately for "Optional" occurrences
521 -> addErrRn (getDeclErr needed_name) `thenRn_`
524 doc_str = ptext SLIT("need decl for") <+> ppr needed_name
527 @getWiredInDecl@ maps a wired-in @Name@ to what it makes available.
528 It behaves exactly as if the wired in decl were actually in an interface file.
531 \item if the wired-in name is a data type constructor or a data constructor,
532 it brings in the type constructor and all the data constructors; and
533 marks as ``occurrences'' any free vars of the data con.
535 \item similarly for synonum type constructor
537 \item if the wired-in name is another wired-in Id, it marks as ``occurrences''
538 the free vars of the Id's type.
540 \item it loads the interface file for the wired-in thing for the
541 sole purpose of making sure that its instance declarations are available
543 All this is necessary so that we know all types that are ``in play'', so
544 that we know just what instances to bring into scope.
549 %*********************************************************
551 \subsection{Getting what a module exports}
553 %*********************************************************
555 @getInterfaceExports@ is called only for directly-imported modules.
558 getInterfaceExports :: ModuleName -> WhereFrom -> RnMG (Module, Avails)
559 getInterfaceExports mod_name from
560 = loadInterface doc_str mod_name from `thenRn` \ (mod, ifaces) ->
561 case lookupFM (iImpModInfo ifaces) mod_name of
562 Nothing -> -- Not there; it must be that the interface file wasn't found;
563 -- the error will have been reported already.
564 -- (Actually loadInterface should put the empty export env in there
565 -- anyway, but this does no harm.)
568 Just (_, _, _, Just (mod, avails)) -> returnRn (mod, avails)
570 doc_str = sep [pprModuleName mod_name, ptext SLIT("is directly imported")]
574 %*********************************************************
576 \subsection{Instance declarations are handled specially}
578 %*********************************************************
581 getImportedInstDecls :: NameSet -> RnMG [(Module,RdrNameHsDecl)]
582 getImportedInstDecls gates
583 = -- First, load any orphan-instance modules that aren't aready loaded
584 -- Orphan-instance modules are recorded in the module dependecnies
585 getIfacesRn `thenRn` \ ifaces ->
588 [mod | (mod, (_, True, _, Nothing)) <- fmToList (iImpModInfo ifaces)]
590 loadOrphanModules orphan_mods `thenRn_`
592 -- Now we're ready to grab the instance declarations
593 -- Find the un-gated ones and return them,
594 -- removing them from the bag kept in Ifaces
595 getIfacesRn `thenRn` \ ifaces ->
597 (decls, new_insts) = selectGated gates (iInsts ifaces)
599 setIfacesRn (ifaces { iInsts = new_insts }) `thenRn_`
601 traceRn (sep [text "getImportedInstDecls:",
602 nest 4 (fsep (map ppr gate_list)),
603 text "Slurped" <+> int (length decls) <+> text "instance declarations",
604 nest 4 (vcat (map ppr_brief_inst_decl decls))]) `thenRn_`
607 gate_list = nameSetToList gates
609 load_home gate | isLocallyDefined gate
612 = loadHomeInterface (ppr gate <+> text "is an instance gate") gate `thenRn_`
615 ppr_brief_inst_decl (mod, InstD (InstDecl inst_ty _ _ _ _))
617 HsForAllTy _ _ tau -> ppr tau
620 getImportedRules :: RnMG [(Module,RdrNameHsDecl)]
622 | opt_IgnoreIfacePragmas = returnRn []
624 = getIfacesRn `thenRn` \ ifaces ->
626 gates = iSlurp ifaces -- Anything at all that's been slurped
627 (decls, new_rules) = selectGated gates (iRules ifaces)
629 setIfacesRn (ifaces { iRules = new_rules }) `thenRn_`
630 traceRn (sep [text "getImportedRules:",
631 text "Slurped" <+> int (length decls) <+> text "rules"]) `thenRn_`
634 selectGated gates decl_bag
635 -- Select only those decls whose gates are *all* in 'gates'
637 | opt_NoPruneDecls -- Just to try the effect of not gating at all
638 = (foldrBag (\ (_,d) ds -> d:ds) [] decl_bag, emptyBag) -- Grab them all
642 = foldrBag select ([], emptyBag) decl_bag
644 select (reqd, decl) (yes, no)
645 | isEmptyNameSet (reqd `minusNameSet` gates) = (decl:yes, no)
646 | otherwise = (yes, (reqd,decl) `consBag` no)
648 lookupFixity :: Name -> RnMS Fixity
650 | isLocallyDefined name
651 = getFixityEnv `thenRn` \ local_fix_env ->
652 case lookupNameEnv local_fix_env name of
653 Just (FixitySig _ fix _) -> returnRn fix
654 Nothing -> returnRn defaultFixity
656 | otherwise -- Imported
657 -- For imported names, we have to get their fixities by doing a loadHomeInterface,
658 -- and consulting the Ifaces that comes back from that, because the interface
659 -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
660 -- which exports a function 'f', which is defined in module B. Then B isn't loaded
661 -- right away (after all, it's possible that nothing from B will be used).
662 -- When we come across a use of 'f', we need to know its fixity, and it's then,
663 -- and only then, that we load B.hi. That is what's happening here.
664 = loadHomeInterface doc name `thenRn` \ ifaces ->
665 case lookupNameEnv (iFixes ifaces) name of
666 Just (FixitySig _ fix _) -> returnRn fix
667 Nothing -> returnRn defaultFixity
669 doc = ptext SLIT("Checking fixity for") <+> ppr name
673 %*********************************************************
675 \subsection{Keeping track of what we've slurped, and version numbers}
677 %*********************************************************
679 getImportVersions figures out what the ``usage information'' for this
680 moudule is; that is, what it must record in its interface file as the
681 things it uses. It records:
684 \item (a) anything reachable from its body code
685 \item (b) any module exported with a @module Foo@
686 \item (c) anything reachable from an exported item
689 Why (b)? Because if @Foo@ changes then this module's export list
690 will change, so we must recompile this module at least as far as
691 making a new interface file --- but in practice that means complete
694 Why (c)? Consider this:
696 module A( f, g ) where | module B( f ) where
697 import B( f ) | f = h 3
701 Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
702 @A@'s usages? Our idea is that we aren't going to touch A.hi if it is
703 *identical* to what it was before. If anything about @B.f@ changes
704 than anyone who imports @A@ should be recompiled in case they use
705 @B.f@ (they'll get an early exit if they don't). So, if anything
706 about @B.f@ changes we'd better make sure that something in A.hi
707 changes, and the convenient way to do that is to record the version
708 number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
709 complete recompiation of A, which is overkill but it's the only way to
710 write a new, slightly different, A.hi.
712 But the example is tricker. Even if @B.f@ doesn't change at all,
713 @B.h@ may do so, and this change may not be reflected in @f@'s version
714 number. But with -O, a module that imports A must be recompiled if
715 @B.h@ changes! So A must record a dependency on @B.h@. So we treat
716 the occurrence of @B.f@ in the export list *just as if* it were in the
717 code of A, and thereby haul in all the stuff reachable from it.
719 [NB: If B was compiled with -O, but A isn't, we should really *still*
720 haul in all the unfoldings for B, in case the module that imports A *is*
721 compiled with -O. I think this is the case.]
723 Even if B is used at all we get a usage line for B
724 import B <n> :: ... ;
725 in A.hi, to record the fact that A does import B. This is used to decide
726 to look to look for B.hi rather than B.hi-boot when compiling a module that
727 imports A. This line says that A imports B, but uses nothing in it.
728 So we'll get an early bale-out when compiling A if B's version changes.
731 getImportVersions :: ModuleName -- Name of this module
732 -> ExportEnv -- Info about exports
733 -> RnMG (VersionInfo Name) -- Version info for these names
735 getImportVersions this_mod (ExportEnv _ _ export_all_mods)
736 = getIfacesRn `thenRn` \ ifaces ->
738 mod_map = iImpModInfo ifaces
739 imp_names = iVSlurp ifaces
741 -- mv_map groups together all the things imported from a particular module.
742 mv_map :: FiniteMap ModuleName [(Name,Version)]
743 mv_map = foldr add_mv emptyFM imp_names
745 -- Build the result list by adding info for each module.
746 -- For (a) a library module, we don't record it at all unless it contains orphans
747 -- (We must never lose track of orphans.)
749 -- (b) a source-imported module, don't record the dependency at all
751 -- (b) may seem a bit strange. The idea is that the usages in a .hi file records
752 -- *all* the module's dependencies other than the loop-breakers. We use
753 -- this info in findAndReadInterface to decide whether to look for a .hi file or
756 -- This means we won't track version changes, or orphans, from .hi-boot files.
757 -- The former is potentially rather bad news. It could be fixed by recording
758 -- whether something is a boot file along with the usage info for it, but
759 -- I can't be bothered just now.
761 mk_version_info mod_name (version, has_orphans, is_boot, contents) so_far
762 | mod_name == this_mod -- Check if M appears in the set of modules 'below' M
763 -- This seems like a convenient place to check
764 = WARN( not is_boot, ptext SLIT("Wierd:") <+> ppr this_mod <+>
765 ptext SLIT("imports itself (perhaps indirectly)") )
770 go_for_it exports = (mod_name, version, has_orphans, is_boot, exports)
774 Nothing -> -- We didn't even open the interface
775 -- This happens when a module, Foo, that we explicitly imported has
776 -- 'import Baz' in its interface file, recording that Baz is below
777 -- Foo in the module dependency hierarchy. We want to propagate this
778 -- information. The Nothing says that we didn't even open the interface
779 -- file but we must still propagate the dependeny info.
780 go_for_it (Specifically [])
782 Just (mod, _) -- We did open the interface
783 | is_lib_module && not has_orphans
786 | is_lib_module -- Record the module but not detailed
787 || mod_name `elem` export_all_mods -- version information for the imports
788 -> go_for_it Everything
791 -> case lookupFM mv_map mod_name of
792 Just whats_imported -> go_for_it (Specifically whats_imported)
793 Nothing -> go_for_it (Specifically [])
794 -- This happens if you have
796 -- but don't actually *use* anything from Foo
797 -- In which case record an empty dependency list
799 is_lib_module = isLibModule mod
803 returnRn (foldFM mk_version_info [] mod_map)
805 add_mv v@(name, version) mv_map
806 = addToFM_C add_item mv_map mod [v]
808 mod = moduleName (nameModule name)
809 add_item vs _ = (v:vs)
814 = getIfacesRn `thenRn` \ ifaces ->
815 returnRn (iSlurp ifaces)
817 recordSlurp maybe_version avail
818 -- Nothing for locally defined names
819 -- Just version for imported names
820 = getIfacesRn `thenRn` \ ifaces@(Ifaces { iSlurp = slurped_names,
821 iVSlurp = imp_names }) ->
823 new_slurped_names = addAvailToNameSet slurped_names avail
825 new_imp_names = case maybe_version of
826 Just version -> (availName avail, version) : imp_names
829 setIfacesRn (ifaces { iSlurp = new_slurped_names,
830 iVSlurp = new_imp_names })
834 %*********************************************************
836 \subsection{Getting binders out of a declaration}
838 %*********************************************************
840 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
841 It's used for both source code (from @availsFromDecl@) and interface files
844 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
845 are handled by the sourc-code specific stuff in @RnNames@.
848 getDeclBinders :: (RdrName -> SrcLoc -> RnM d Name) -- New-name function
850 -> RnM d (Maybe AvailInfo)
852 getDeclBinders new_name (TyClD (TyData _ _ tycon _ condecls _ _ src_loc))
853 = new_name tycon src_loc `thenRn` \ tycon_name ->
854 getConFieldNames new_name condecls `thenRn` \ sub_names ->
855 returnRn (Just (AvailTC tycon_name (tycon_name : nub sub_names)))
856 -- The "nub" is because getConFieldNames can legitimately return duplicates,
857 -- when a record declaration has the same field in multiple constructors
859 getDeclBinders new_name (TyClD (TySynonym tycon _ _ src_loc))
860 = new_name tycon src_loc `thenRn` \ tycon_name ->
861 returnRn (Just (AvailTC tycon_name [tycon_name]))
863 getDeclBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ _ _ _ _ src_loc))
864 = new_name cname src_loc `thenRn` \ class_name ->
866 -- Record the names for the class ops
868 -- just want class-op sigs
869 op_sigs = filter isClassOpSig sigs
871 mapRn (getClassOpNames new_name) op_sigs `thenRn` \ sub_names ->
873 returnRn (Just (AvailTC class_name (class_name : sub_names)))
875 getDeclBinders new_name (SigD (IfaceSig var ty prags src_loc))
876 = new_name var src_loc `thenRn` \ var_name ->
877 returnRn (Just (Avail var_name))
879 getDeclBinders new_name (FixD _) = returnRn Nothing
881 -- foreign declarations
882 getDeclBinders new_name (ForD (ForeignDecl nm kind _ dyn _ loc))
883 | binds_haskell_name kind dyn
884 = new_name nm loc `thenRn` \ name ->
885 returnRn (Just (Avail name))
887 | otherwise -- a foreign export
888 = lookupImplicitOccRn nm `thenRn_`
891 getDeclBinders new_name (DefD _) = returnRn Nothing
892 getDeclBinders new_name (InstD _) = returnRn Nothing
893 getDeclBinders new_name (RuleD _) = returnRn Nothing
895 binds_haskell_name (FoImport _) _ = True
896 binds_haskell_name FoLabel _ = True
897 binds_haskell_name FoExport ext_nm = isDynamicExtName ext_nm
900 getConFieldNames new_name (ConDecl con _ _ _ (RecCon fielddecls) src_loc : rest)
901 = mapRn (\n -> new_name n src_loc) (con:fields) `thenRn` \ cfs ->
902 getConFieldNames new_name rest `thenRn` \ ns ->
905 fields = concat (map fst fielddecls)
907 getConFieldNames new_name (ConDecl con _ _ _ condecl src_loc : rest)
908 = new_name con src_loc `thenRn` \ n ->
911 new_name f src_loc `thenRn` \ new_f ->
913 _ -> returnRn [n]) `thenRn` \ nn ->
914 getConFieldNames new_name rest `thenRn` \ ns ->
917 getConFieldNames new_name [] = returnRn []
919 getClassOpNames new_name (ClassOpSig op _ _ _ src_loc) = new_name op src_loc
922 @getDeclSysBinders@ gets the implicit binders introduced by a decl.
923 A the moment that's just the tycon and datacon that come with a class decl.
924 They aren't returned by @getDeclBinders@ because they aren't in scope;
925 but they {\em should} be put into the @DeclsMap@ of this module.
927 Note that this excludes the default-method names of a class decl,
928 and the dict fun of an instance decl, because both of these have
929 bindings of their own elsewhere.
932 getDeclSysBinders new_name (TyClD (ClassDecl _ cname _ _ sigs _ _ tname dname dwname snames src_loc))
933 = sequenceRn [new_name n src_loc | n <- (tname : dname : dwname : snames)]
935 getDeclSysBinders new_name (TyClD (TyData _ _ _ _ cons _ _ _))
936 = sequenceRn [new_name wkr_name src_loc | ConDecl _ wkr_name _ _ _ src_loc <- cons]
938 getDeclSysBinders new_name other_decl
942 %*********************************************************
944 \subsection{Reading an interface file}
946 %*********************************************************
949 findAndReadIface :: SDoc -> ModuleName -> WhereFrom
950 -> Bool -- Only relevant for SystemImport
951 -- True <=> Look for a .hi file
952 -- False <=> Look for .hi-boot file unless there's
953 -- a library .hi file
954 -> RnM d (Bool, Maybe (Module, ParsedIface))
955 -- Bool is True if the interface actually read was a .hi-boot one
956 -- Nothing <=> file not found, or unreadable, or illegible
957 -- Just x <=> successfully found and parsed
959 findAndReadIface doc_str mod_name from hi_file
960 = traceRn trace_msg `thenRn_`
961 -- we keep two maps for interface files,
962 -- one for 'normal' ones, the other for .hi-boot files,
963 -- hence the need to signal which kind we're interested.
965 getHiMaps `thenRn` \ hi_maps ->
967 case find_path from hi_maps of
969 (hi_boot, Just (fpath, mod)) -> traceRn (ptext SLIT("...reading from") <+> text fpath)
971 readIface mod fpath `thenRn` \ result ->
972 returnRn (hi_boot, result)
973 (hi_boot, Nothing) -> traceRn (ptext SLIT("...not found")) `thenRn_`
974 returnRn (hi_boot, Nothing)
976 find_path ImportByUser (hi_map, _) = (False, lookupFM hi_map mod_name)
977 find_path ImportByUserSource (_, hiboot_map) = (True, lookupFM hiboot_map mod_name)
979 find_path ImportBySystem (hi_map, hiboot_map)
981 = -- If the module we seek is in our dependent set,
982 -- Look for a .hi file
983 (False, lookupFM hi_map mod_name)
986 -- Check if there's a library module of that name
987 -- If not, look for an hi-boot file
988 = case lookupFM hi_map mod_name of
989 stuff@(Just (_, mod)) | isLibModule mod -> (False, stuff)
990 other -> (True, lookupFM hiboot_map mod_name)
992 trace_msg = sep [hsep [ptext SLIT("Reading"),
994 ptext SLIT("interface for"),
995 pprModuleName mod_name <> semi],
996 nest 4 (ptext SLIT("reason:") <+> doc_str)]
999 @readIface@ tries just the one file.
1002 readIface :: Module -> String -> RnM d (Maybe (Module, ParsedIface))
1003 -- Nothing <=> file not found, or unreadable, or illegible
1004 -- Just x <=> successfully found and parsed
1005 readIface the_mod file_path
1006 = ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
1009 case parseIface contents
1010 PState{ bol = 0#, atbol = 1#,
1013 loc = mkSrcLoc (mkFastString file_path) 1 } of
1014 POk _ (PIface mod_nm iface) ->
1015 warnCheckRn (mod_nm == moduleName the_mod)
1016 (hiModuleNameMismatchWarn the_mod mod_nm) `thenRn_`
1017 returnRn (Just (the_mod, iface))
1019 PFailed err -> failWithRn Nothing err
1020 other -> failWithRn Nothing (ptext SLIT("Unrecognisable interface file"))
1021 -- This last case can happen if the interface file is (say) empty
1022 -- in which case the parser thinks it looks like an IdInfo or
1023 -- something like that. Just an artefact of the fact that the
1024 -- parser is used for several purposes at once.
1027 | isDoesNotExistError err -> returnRn Nothing
1028 | otherwise -> failWithRn Nothing (cannaeReadFile file_path err)
1031 %*********************************************************
1035 %*********************************************************
1038 noIfaceErr filename boot_file
1039 = hsep [ptext SLIT("Could not find valid"), boot,
1040 ptext SLIT("interface file"), quotes (pprModule filename)]
1042 boot | boot_file = ptext SLIT("[boot]")
1045 cannaeReadFile file err
1046 = hcat [ptext SLIT("Failed in reading file: "),
1048 ptext SLIT("; error="),
1052 = ptext SLIT("Failed to find interface decl for") <+> quotes (ppr name)
1054 getDeclWarn name loc
1055 = sep [ptext SLIT("Failed to find (optional) interface decl for") <+> quotes (ppr name),
1056 ptext SLIT("desired at") <+> ppr loc]
1060 "Compiler tried to import decl from interface file with same name as module."),
1062 "(possible cause: module name clashes with interface file already in scope.)")
1064 hsep [ptext SLIT("name:"), quotes (ppr name)]
1066 warnRedundantSourceImport mod_name
1067 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
1068 <+> quotes (pprModuleName mod_name)
1070 hiModuleNameMismatchWarn :: Module -> ModuleName -> Message
1071 hiModuleNameMismatchWarn requested_mod mod_nm =
1072 hsep [ ptext SLIT("Something is amiss; requested module name")
1073 , pprModule requested_mod
1074 , ptext SLIT("differs from name found in the interface file ")
1075 , pprModuleName mod_nm