2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section{Dealing with interface files}
8 readIface, findAndReadIface, loadInterface, loadHomeInterface,
9 tryLoadInterface, loadOrphanModules,
10 loadExports, loadFixDecls, loadDeprecs,
15 removeContext -- removeContext probably belongs somewhere else
18 #include "HsVersions.h"
20 import DriverState ( GhcMode(..), v_GhcMode )
21 import DriverUtil ( splitFilename )
22 import CmdLineOpts ( opt_IgnoreIfacePragmas )
23 import HscTypes ( ModuleLocation(..),
24 ModIface(..), emptyModIface,
25 VersionInfo(..), ImportedModuleInfo,
27 ImportVersion, WhetherHasOrphans, IsBootInterface,
28 DeclsMap, GatedDecl, IfaceInsts, IfaceRules,
29 AvailInfo, GenAvailInfo(..), Avails, Deprecations(..)
31 import HsSyn ( TyClDecl(..), InstDecl(..),
32 HsType(..), FixitySig(..), RuleDecl(..),
33 tyClDeclNames, tyClDeclSysNames
35 import RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl,
38 import BasicTypes ( Version, defaultFixity )
41 import ParseIface ( parseIface )
43 import Name ( Name {-instance NamedThing-},
44 nameModule, isLocalName, nameIsLocalOrFrom
48 import RdrName ( rdrNameOcc )
49 import SrcLoc ( mkSrcLoc )
50 import Maybes ( maybeToBool, orElse )
51 import StringBuffer ( hGetStringBuffer )
52 import FastString ( mkFastString )
53 import ErrUtils ( Message )
54 import Finder ( findModule, findPackageModule )
66 %*********************************************************
68 \subsection{Loading a new interface file}
70 %*********************************************************
73 loadHomeInterface :: SDoc -> Name -> RnM d ModIface
74 loadHomeInterface doc_str name
75 = ASSERT2( not (isLocalName name), ppr name <+> parens doc_str )
76 loadInterface doc_str (moduleName (nameModule name)) ImportBySystem
78 loadOrphanModules :: [ModuleName] -> RnM d ()
79 loadOrphanModules mods
80 | null mods = returnRn ()
81 | otherwise = traceRn (text "Loading orphan modules:" <+>
82 fsep (map ppr mods)) `thenRn_`
83 mapRn_ load mods `thenRn_`
86 load mod = loadInterface (mk_doc mod) mod ImportBySystem
87 mk_doc mod = ppr mod <+> ptext SLIT("is a orphan-instance module")
89 loadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d ModIface
90 loadInterface doc mod from
91 = tryLoadInterface doc mod from `thenRn` \ (ifaces, maybe_err) ->
93 Nothing -> returnRn ifaces
94 Just err -> failWithRn ifaces (elaborate err)
96 elaborate err = hang (ptext SLIT("failed to load interface for") <+> quotes (ppr mod) <> colon)
99 tryLoadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d (ModIface, Maybe Message)
100 -- Returns (Just err) if an error happened
101 -- It *doesn't* add an error to the monad, because sometimes it's ok to fail...
102 -- Specifically, when we read the usage information from an interface file,
103 -- we try to read the interfaces it mentions. But it's OK to fail; perhaps
104 -- the module has changed, and that interface is no longer used.
106 -- tryLoadInterface guarantees to return with iImpModInfo m --> (..., True)
107 -- (If the load fails, we plug in a vanilla placeholder)
108 tryLoadInterface doc_str mod_name from
109 = getHomeIfaceTableRn `thenRn` \ hit ->
110 getModuleRn `thenRn` \ this_mod ->
111 getIfacesRn `thenRn` \ ifaces@(Ifaces { iPIT = pit }) ->
113 -- CHECK WHETHER WE HAVE IT ALREADY
114 case lookupIfaceByModName hit pit mod_name of {
115 Just iface | case from of
116 ImportByUser -> not (mi_boot iface)
117 ImportByUserSource -> mi_boot iface
118 ImportBySystem -> True
119 -> returnRn (iface, Nothing) ; -- Already loaded
120 -- The not (mi_boot iface) test checks that the already-loaded
121 -- interface isn't a boot iface. This can conceivably happen,
122 -- if the version checking happened to load a boot interface
123 -- before we got to real imports.
127 mod_map = iImpModInfo ifaces
128 mod_info = lookupFM mod_map mod_name
131 = case (from, mod_info) of
132 (ImportByUser, _) -> False -- Not hi-boot
133 (ImportByUserSource, _) -> True -- hi-boot
134 (ImportBySystem, Just (_, is_boot)) -> is_boot
135 (ImportBySystem, Nothing) -> False
136 -- We're importing a module we know absolutely
137 -- nothing about, so we assume it's from
138 -- another package, where we aren't doing
139 -- dependency tracking. So it won't be a hi-boot file.
141 redundant_source_import
142 = case (from, mod_info) of
143 (ImportByUserSource, Just (_,False)) -> True
147 -- Issue a warning for a redundant {- SOURCE -} import
148 -- NB that we arrange to read all the ordinary imports before
149 -- any of the {- SOURCE -} imports
150 warnCheckRn (not redundant_source_import)
151 (warnRedundantSourceImport mod_name) `thenRn_`
153 -- Check that we aren't importing ourselves.
154 -- That only happens in Rename.checkOldIface,
155 -- which doesn't call tryLoadInterface
157 (not (isHomeModule this_mod) || moduleName this_mod /= mod_name)
158 (warnSelfImport this_mod) `thenRn_`
160 -- READ THE MODULE IN
161 findAndReadIface doc_str mod_name hi_boot_file
162 `thenRn` \ read_result ->
163 case read_result of {
164 Left err -> -- Not found, so add an empty export env to the Ifaces map
165 -- so that we don't look again
167 fake_mod = mkVanillaModule mod_name
168 fake_iface = emptyModIface fake_mod
169 new_ifaces = ifaces { iPIT = extendModuleEnv pit fake_mod fake_iface }
171 setIfacesRn new_ifaces `thenRn_`
172 returnRn (fake_iface, Just err) ;
175 Right (mod, iface) ->
177 -- LOAD IT INTO Ifaces
179 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
180 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
181 -- If we do loadExport first the wrong info gets into the cache (unless we
182 -- explicitly tag each export which seems a bit of a bore)
185 -- Sanity check. If we're system-importing a module we know nothing at all
186 -- about, it should be from a different package to this one
187 WARN( not (maybeToBool mod_info) &&
188 case from of { ImportBySystem -> True; other -> False } &&
192 loadDecls mod (iDecls ifaces) (pi_decls iface) `thenRn` \ (decls_vers, new_decls) ->
193 loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ (rule_vers, new_rules) ->
194 loadInstDecls mod (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
195 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
196 loadFixDecls mod (pi_fixity iface) `thenRn` \ fix_env ->
197 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
199 version = VersionInfo { vers_module = pi_vers iface,
200 vers_exports = export_vers,
201 vers_rules = rule_vers,
202 vers_decls = decls_vers }
204 -- For an explicit user import, add to mod_map info about
205 -- the things the imported module depends on, extracted
206 -- from its usage info; and delete the module itself, which is now in the PIT
207 mod_map1 = case from of
208 ImportByUser -> addModDeps mod is_loaded (pi_usages iface) mod_map
210 mod_map2 = delFromFM mod_map1 mod_name
212 this_mod_name = moduleName this_mod
213 is_loaded m = m == this_mod_name
214 || maybeToBool (lookupIfaceByModName hit pit m)
215 -- We treat the currently-being-compiled module as 'loaded' because
216 -- even though it isn't yet in the HIT or PIT; otherwise it gets
217 -- put into iImpModInfo, and then spat out into its own interface
218 -- file as a dependency
220 -- Now add info about this module to the PIT
221 has_orphans = pi_orphan iface
222 new_pit = extendModuleEnv pit mod mod_iface
223 mod_iface = ModIface { mi_module = mod, mi_version = version,
224 mi_orphan = has_orphans, mi_boot = hi_boot_file,
226 mi_fixities = fix_env, mi_deprecs = deprec_env,
227 mi_usages = [], -- Will be filled in later
228 mi_decls = panic "No mi_decls in PIT",
229 mi_globals = mkIfaceGlobalRdrEnv avails
232 new_ifaces = ifaces { iPIT = new_pit,
236 iImpModInfo = mod_map2 }
238 setIfacesRn new_ifaces `thenRn_`
239 returnRn (mod_iface, Nothing)
242 -----------------------------------------------------
243 -- Adding module dependencies from the
244 -- import decls in the interface file
245 -----------------------------------------------------
248 -> (ModuleName -> Bool) -- True for modules that are already loaded
250 -> ImportedModuleInfo -> ImportedModuleInfo
251 -- (addModDeps M ivs deps)
252 -- We are importing module M, and M.hi contains 'import' decls given by ivs
253 addModDeps mod is_loaded new_deps mod_deps
254 = foldr add mod_deps filtered_new_deps
256 -- Don't record dependencies when importing a module from another package
257 -- Except for its descendents which contain orphans,
258 -- and in that case, forget about the boot indicator
259 filtered_new_deps :: [(ModuleName, (WhetherHasOrphans, IsBootInterface))]
261 | isHomeModule mod = [ (imp_mod, (has_orphans, is_boot))
262 | (imp_mod, has_orphans, is_boot, _) <- new_deps,
263 not (is_loaded imp_mod)
265 | otherwise = [ (imp_mod, (True, False))
266 | (imp_mod, has_orphans, _, _) <- new_deps,
267 not (is_loaded imp_mod) && has_orphans
269 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
271 combine old@(old_has_orphans, old_is_boot) new@(new_has_orphans, new_is_boot)
272 | old_is_boot = new -- Record the best is_boot info
275 -----------------------------------------------------
276 -- Loading the export list
277 -----------------------------------------------------
279 loadExports :: (Version, [ExportItem]) -> RnM d (Version, [(ModuleName,Avails)])
280 loadExports (vers, items)
281 = mapRn loadExport items `thenRn` \ avails_s ->
282 returnRn (vers, avails_s)
285 loadExport :: ExportItem -> RnM d (ModuleName, Avails)
286 loadExport (mod, entities)
287 = mapRn (load_entity mod) entities `thenRn` \ avails ->
288 returnRn (mod, avails)
290 load_entity mod (Avail occ)
291 = newGlobalName mod occ `thenRn` \ name ->
292 returnRn (Avail name)
293 load_entity mod (AvailTC occ occs)
294 = newGlobalName mod occ `thenRn` \ name ->
295 mapRn (newGlobalName mod) occs `thenRn` \ names ->
296 returnRn (AvailTC name names)
299 -----------------------------------------------------
300 -- Loading type/class/value decls
301 -----------------------------------------------------
305 -> [(Version, RdrNameTyClDecl)]
306 -> RnM d (NameEnv Version, DeclsMap)
307 loadDecls mod (decls_map, n_slurped) decls
308 = foldlRn (loadDecl mod) (emptyNameEnv, decls_map) decls `thenRn` \ (vers, decls_map') ->
309 returnRn (vers, (decls_map', n_slurped))
311 loadDecl mod (version_map, decls_map) (version, decl)
312 = getTyClDeclBinders mod decl `thenRn` \ (avail, sys_names) ->
314 full_avail = case avail of
316 AvailTC n ns -> AvailTC n (sys_names ++ ns)
317 main_name = availName full_avail
318 new_decls_map = extendNameEnvList decls_map stuff
319 stuff = [ (name, (full_avail, name==main_name, (mod, decl)))
320 | name <- availNames full_avail]
322 new_version_map = extendNameEnv version_map main_name version
324 returnRn (new_version_map, new_decls_map)
326 -----------------------------------------------------
327 -- Loading fixity decls
328 -----------------------------------------------------
330 loadFixDecls mod decls
331 = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
332 returnRn (mkNameEnv to_add)
334 mod_name = moduleName mod
336 loadFixDecl mod_name sig@(FixitySig rdr_name fixity loc)
337 = newGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
338 returnRn (name, fixity)
341 -----------------------------------------------------
342 -- Loading instance decls
343 -----------------------------------------------------
345 loadInstDecls :: Module
349 loadInstDecls mod (insts, n_slurped) decls
351 foldlRn (loadInstDecl mod) insts decls `thenRn` \ insts' ->
352 returnRn (insts', n_slurped)
355 loadInstDecl mod insts decl@(InstDecl inst_ty _ _ _ _)
356 = -- Find out what type constructors and classes are "gates" for the
357 -- instance declaration. If all these "gates" are slurped in then
358 -- we should slurp the instance decl too.
360 -- We *don't* want to count names in the context part as gates, though.
362 -- instance Foo a => Baz (T a) where ...
364 -- Here the gates are Baz and T, but *not* Foo.
366 munged_inst_ty = removeContext inst_ty
367 free_names = extractHsTyRdrNames munged_inst_ty
369 mapRn lookupIfaceName free_names `thenRn` \ gate_names ->
370 returnRn ((gate_names, (mod, decl)) `consBag` insts)
373 -- In interface files, the instance decls now look like
374 -- forall a. Foo a -> Baz (T a)
375 -- so we have to strip off function argument types as well
376 -- as the bit before the '=>' (which is always empty in interface files)
377 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
378 removeContext ty = removeFuns ty
380 removeFuns (HsFunTy _ ty) = removeFuns ty
384 -----------------------------------------------------
386 -----------------------------------------------------
388 loadRules :: Module -> IfaceRules
389 -> (Version, [RdrNameRuleDecl])
390 -> RnM d (Version, IfaceRules)
391 loadRules mod (rule_bag, n_slurped) (version, rules)
392 | null rules || opt_IgnoreIfacePragmas
393 = returnRn (version, (rule_bag, n_slurped))
396 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
397 returnRn (version, (rule_bag `unionBags` listToBag new_rules, n_slurped))
399 loadRule :: Module -> RdrNameRuleDecl -> RnM d (GatedDecl RdrNameRuleDecl)
400 -- "Gate" the rule simply by whether the rule variable is
401 -- needed. We can refine this later.
402 loadRule mod decl@(IfaceRule _ _ var _ _ src_loc)
403 = lookupIfaceName var `thenRn` \ var_name ->
404 returnRn ([var_name], (mod, decl))
407 -----------------------------------------------------
408 -- Loading Deprecations
409 -----------------------------------------------------
411 loadDeprecs :: Module -> IfaceDeprecs -> RnM d Deprecations
412 loadDeprecs m Nothing = returnRn NoDeprecs
413 loadDeprecs m (Just (Left txt)) = returnRn (DeprecAll txt)
414 loadDeprecs m (Just (Right prs)) = setModuleRn m $
415 foldlRn loadDeprec emptyNameEnv prs `thenRn` \ env ->
416 returnRn (DeprecSome env)
417 loadDeprec deprec_env (n, txt)
418 = lookupIfaceName n `thenRn` \ name ->
419 traceRn (text "Loaded deprecation(s) for" <+> ppr name <> colon <+> ppr txt) `thenRn_`
420 returnRn (extendNameEnv deprec_env name (name,txt))
424 %*********************************************************
426 \subsection{Getting binders out of a declaration}
428 %*********************************************************
430 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
431 It's used for both source code (from @availsFromDecl@) and interface files
434 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
435 are handled by the sourc-code specific stuff in @RnNames@.
437 *** See "THE NAMING STORY" in HsDecls ****
444 -> RnM d (AvailInfo, [Name]) -- The [Name] are the system names
447 getTyClDeclBinders mod (IfaceSig {tcdName = var, tcdLoc = src_loc})
448 = newTopBinder mod var src_loc `thenRn` \ var_name ->
449 returnRn (Avail var_name, [])
451 getTyClDeclBinders mod tycl_decl
452 = new_top_bndrs mod (tyClDeclNames tycl_decl) `thenRn` \ names@(main_name:_) ->
453 new_top_bndrs mod (tyClDeclSysNames tycl_decl) `thenRn` \ sys_names ->
454 returnRn (AvailTC main_name names, sys_names)
457 new_top_bndrs mod names_w_locs
458 = sequenceRn [newTopBinder mod name loc | (name,loc) <- names_w_locs]
462 %*********************************************************
464 \subsection{Reading an interface file}
466 %*********************************************************
469 findAndReadIface :: SDoc -> ModuleName
470 -> IsBootInterface -- True <=> Look for a .hi-boot file
471 -- False <=> Look for .hi file
472 -> RnM d (Either Message (Module, ParsedIface))
473 -- Nothing <=> file not found, or unreadable, or illegible
474 -- Just x <=> successfully found and parsed
476 findAndReadIface doc_str mod_name hi_boot_file
477 = traceRn trace_msg `thenRn_`
479 -- In interactive or --make mode, we are *not allowed* to demand-load
480 -- a home package .hi file. So don't even look for them.
481 -- This helps in the case where you are sitting in eg. ghc/lib/std
482 -- and start up GHCi - it won't complain that all the modules it tries
483 -- to load are found in the home location.
484 ioToRnM_no_fail (readIORef v_GhcMode) `thenRn` \ mode ->
485 let home_allowed = hi_boot_file ||
486 mode `notElem` [ DoInteractive, DoMake ]
489 ioToRnM (if home_allowed
490 then findModule mod_name
491 else findPackageModule mod_name) `thenRn` \ maybe_found ->
495 Right (Just (wanted_mod,locn))
496 -> mkHiPath hi_boot_file locn `thenRn` \ file ->
497 readIface file `thenRn` \ read_result ->
499 Left bad -> returnRn (Left bad)
501 -> let read_mod = pi_mod iface
502 in -- check that the module names agree
504 (wanted_mod == read_mod)
505 (hiModuleNameMismatchWarn wanted_mod read_mod)
507 -- check that the package names agree
509 (modulePackage wanted_mod == modulePackage read_mod)
510 (packageNameMismatchWarn wanted_mod read_mod)
512 returnRn (Right (wanted_mod, iface))
514 other -> traceRn (ptext SLIT("...not found")) `thenRn_`
515 returnRn (Left (noIfaceErr mod_name hi_boot_file))
518 trace_msg = sep [hsep [ptext SLIT("Reading"),
519 if hi_boot_file then ptext SLIT("[boot]") else empty,
520 ptext SLIT("interface for"),
521 ppr mod_name <> semi],
522 nest 4 (ptext SLIT("reason:") <+> doc_str)]
524 mkHiPath hi_boot_file locn
526 ioToRnM_no_fail (doesFileExist hi_boot_ver_path) `thenRn` \ b ->
527 if b then returnRn hi_boot_ver_path
528 else returnRn hi_boot_path
529 | otherwise = returnRn hi_path
530 where hi_path = ml_hi_file locn
531 (hi_base, _hi_suf) = splitFilename hi_path
532 hi_boot_path = hi_base ++ ".hi-boot"
533 hi_boot_ver_path = hi_base ++ ".hi-boot-" ++ cHscIfaceFileVersion
536 @readIface@ tries just the one file.
539 readIface :: String -> RnM d (Either Message ParsedIface)
540 -- Nothing <=> file not found, or unreadable, or illegible
541 -- Just x <=> successfully found and parsed
543 = --ioToRnM (putStrLn ("reading iface " ++ file_path)) `thenRn_`
544 traceRn (ptext SLIT("readIFace") <+> text file_path) `thenRn_`
546 ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
547 case read_result of {
548 Left io_error -> bale_out (text (show io_error)) ;
551 case parseIface contents init_parser_state of
552 POk _ iface -> returnRn (Right iface)
553 PFailed err -> bale_out err
556 init_parser_state = PState{ bol = 0#, atbol = 1#,
559 loc = mkSrcLoc (mkFastString file_path) 1 }
561 bale_out err = returnRn (Left (badIfaceFile file_path err))
565 %*********************************************************
567 \subsection{Looking up fixities}
569 %*********************************************************
571 @lookupFixityRn@ has to be in RnIfaces (or RnHiFiles) because
572 it calls @loadHomeInterface@.
574 lookupFixity is a bit strange.
576 * Nested local fixity decls are put in the local fixity env, which we
577 find with getFixtyEnv
579 * Imported fixities are found in the HIT or PIT
581 * Top-level fixity decls in this module may be for Names that are
582 either Global (constructors, class operations)
583 or Local/Exported (everything else)
584 (See notes with RnNames.getLocalDeclBinders for why we have this split.)
585 We put them all in the local fixity environment
588 lookupFixityRn :: Name -> RnMS Fixity
590 = getModuleRn `thenRn` \ this_mod ->
591 if nameIsLocalOrFrom this_mod name
592 then -- It's defined in this module
593 getFixityEnv `thenRn` \ local_fix_env ->
594 returnRn (lookupLocalFixity local_fix_env name)
596 else -- It's imported
597 -- For imported names, we have to get their fixities by doing a loadHomeInterface,
598 -- and consulting the Ifaces that comes back from that, because the interface
599 -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
600 -- which exports a function 'f', which is defined in module B. Then B isn't loaded
601 -- right away (after all, it's possible that nothing from B will be used).
602 -- When we come across a use of 'f', we need to know its fixity, and it's then,
603 -- and only then, that we load B.hi. That is what's happening here.
604 loadHomeInterface doc name `thenRn` \ iface ->
605 returnRn (lookupNameEnv (mi_fixities iface) name `orElse` defaultFixity)
607 doc = ptext SLIT("Checking fixity for") <+> ppr name
611 %*********************************************************
615 %*********************************************************
618 noIfaceErr mod_name boot_file
619 = ptext SLIT("Could not find interface file for") <+> quotes (ppr mod_name)
620 -- We used to print the search path, but we can't do that
621 -- now, because it's hidden inside the finder.
622 -- Maybe the finder should expose more functions.
624 badIfaceFile file err
625 = vcat [ptext SLIT("Bad interface file:") <+> text file,
628 hiModuleNameMismatchWarn :: Module -> Module -> Message
629 hiModuleNameMismatchWarn requested_mod read_mod =
630 hsep [ ptext SLIT("Something is amiss; requested module name")
631 , ppr (moduleName requested_mod)
632 , ptext SLIT("differs from name found in the interface file")
636 packageNameMismatchWarn :: Module -> Module -> Message
637 packageNameMismatchWarn requested_mod read_mod =
638 fsep [ ptext SLIT("Module"), quotes (ppr requested_mod),
639 ptext SLIT("is located in package"),
640 quotes (ptext (modulePackage requested_mod)),
641 ptext SLIT("but its interface file claims it is part of package"),
642 quotes (ptext (modulePackage read_mod))
645 warnRedundantSourceImport mod_name
646 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
647 <+> quotes (ppr mod_name)
650 = ptext SLIT("Module") <+> quotes (ppr mod) <+> ptext SLIT("is not loaded")
653 = ptext SLIT("Importing my own interface: module") <+> ppr mod