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 DriverUtil ( splitFilename )
21 import CmdLineOpts ( opt_IgnoreIfacePragmas )
22 import HscTypes ( ModuleLocation(..),
23 ModIface(..), emptyModIface,
24 VersionInfo(..), ImportedModuleInfo,
26 ImportVersion, WhetherHasOrphans, IsBootInterface,
27 DeclsMap, GatedDecl, IfaceInsts, IfaceRules,
28 AvailInfo, GenAvailInfo(..), Avails, Deprecations(..)
30 import HsSyn ( TyClDecl(..), InstDecl(..),
31 HsType(..), FixitySig(..), RuleDecl(..),
32 tyClDeclNames, tyClDeclSysNames
34 import RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl,
37 import BasicTypes ( Version, defaultFixity )
40 import ParseIface ( parseIface, IfaceStuff(..) )
42 import Name ( Name {-instance NamedThing-}, nameOccName,
43 nameModule, isLocalName, nameIsLocalOrFrom,
46 import Name ( mkNameEnv, extendNameEnv )
47 import Module ( Module,
48 moduleName, isHomeModule,
49 ModuleName, WhereFrom(..),
50 extendModuleEnv, mkVanillaModule
52 import RdrName ( RdrName, rdrNameOcc )
53 import SrcLoc ( mkSrcLoc )
54 import Maybes ( maybeToBool, orElse )
55 import StringBuffer ( hGetStringBuffer )
56 import FastString ( mkFastString )
57 import ErrUtils ( Message )
58 import Finder ( findModule )
69 %*********************************************************
71 \subsection{Loading a new interface file}
73 %*********************************************************
76 loadHomeInterface :: SDoc -> Name -> RnM d ModIface
77 loadHomeInterface doc_str name
78 = ASSERT2( not (isLocalName name), ppr name <+> parens doc_str )
79 loadInterface doc_str (moduleName (nameModule name)) ImportBySystem
81 loadOrphanModules :: [ModuleName] -> RnM d ()
82 loadOrphanModules mods
83 | null mods = returnRn ()
84 | otherwise = traceRn (text "Loading orphan modules:" <+>
85 fsep (map ppr mods)) `thenRn_`
86 mapRn_ load mods `thenRn_`
89 load mod = loadInterface (mk_doc mod) mod ImportBySystem
90 mk_doc mod = ppr mod <+> ptext SLIT("is a orphan-instance module")
92 loadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d ModIface
93 loadInterface doc mod from
94 = tryLoadInterface doc mod from `thenRn` \ (ifaces, maybe_err) ->
96 Nothing -> returnRn ifaces
97 Just err -> failWithRn ifaces err
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
156 warnCheckRn (moduleName this_mod /= mod_name)
157 (warnSelfImport this_mod) `thenRn_`
159 -- READ THE MODULE IN
160 findAndReadIface doc_str mod_name hi_boot_file `thenRn` \ read_result ->
161 case read_result of {
162 Left err -> -- Not found, so add an empty export env to the Ifaces map
163 -- so that we don't look again
165 fake_mod = mkVanillaModule mod_name
166 fake_iface = emptyModIface fake_mod
167 new_ifaces = ifaces { iPIT = extendModuleEnv pit fake_mod fake_iface }
169 setIfacesRn new_ifaces `thenRn_`
170 returnRn (fake_iface, Just err) ;
173 Right (mod, iface) ->
175 -- LOAD IT INTO Ifaces
177 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
178 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
179 -- If we do loadExport first the wrong info gets into the cache (unless we
180 -- explicitly tag each export which seems a bit of a bore)
183 -- Sanity check. If we're system-importing a module we know nothing at all
184 -- about, it should be from a different package to this one
185 WARN( not (maybeToBool mod_info) &&
186 case from of { ImportBySystem -> True; other -> False } &&
190 loadDecls mod (iDecls ifaces) (pi_decls iface) `thenRn` \ (decls_vers, new_decls) ->
191 loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ (rule_vers, new_rules) ->
192 loadInstDecls mod (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
193 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
194 loadFixDecls mod (pi_fixity iface) `thenRn` \ fix_env ->
195 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
197 version = VersionInfo { vers_module = pi_vers iface,
198 vers_exports = export_vers,
199 vers_rules = rule_vers,
200 vers_decls = decls_vers }
202 -- For an explicit user import, add to mod_map info about
203 -- the things the imported module depends on, extracted
204 -- from its usage info; and delete the module itself, which is now in the PIT
205 mod_map1 = case from of
206 ImportByUser -> addModDeps mod is_loaded (pi_usages iface) mod_map
208 mod_map2 = delFromFM mod_map1 mod_name
210 this_mod_name = moduleName this_mod
211 is_loaded m = m == this_mod_name
212 || maybeToBool (lookupIfaceByModName hit pit m)
213 -- We treat the currently-being-compiled module as 'loaded' because
214 -- even though it isn't yet in the HIT or PIT; otherwise it gets
215 -- put into iImpModInfo, and then spat out into its own interface
216 -- file as a dependency
218 -- Now add info about this module to the PIT
219 has_orphans = pi_orphan iface
220 new_pit = extendModuleEnv pit mod mod_iface
221 mod_iface = ModIface { mi_module = mod, mi_version = version,
222 mi_orphan = has_orphans, mi_boot = hi_boot_file,
224 mi_fixities = fix_env, mi_deprecs = deprec_env,
225 mi_usages = [], -- Will be filled in later
226 mi_decls = panic "No mi_decls in PIT",
227 mi_globals = mkIfaceGlobalRdrEnv avails
230 new_ifaces = ifaces { iPIT = new_pit,
234 iImpModInfo = mod_map2 }
236 setIfacesRn new_ifaces `thenRn_`
237 returnRn (mod_iface, Nothing)
240 -----------------------------------------------------
241 -- Adding module dependencies from the
242 -- import decls in the interface file
243 -----------------------------------------------------
246 -> (ModuleName -> Bool) -- True for modules that are already loaded
248 -> ImportedModuleInfo -> ImportedModuleInfo
249 -- (addModDeps M ivs deps)
250 -- We are importing module M, and M.hi contains 'import' decls given by ivs
251 addModDeps mod is_loaded new_deps mod_deps
252 = foldr add mod_deps filtered_new_deps
254 -- Don't record dependencies when importing a module from another package
255 -- Except for its descendents which contain orphans,
256 -- and in that case, forget about the boot indicator
257 filtered_new_deps :: [(ModuleName, (WhetherHasOrphans, IsBootInterface))]
259 | isHomeModule mod = [ (imp_mod, (has_orphans, is_boot))
260 | (imp_mod, has_orphans, is_boot, _) <- new_deps,
261 not (is_loaded imp_mod)
263 | otherwise = [ (imp_mod, (True, False))
264 | (imp_mod, has_orphans, _, _) <- new_deps,
265 not (is_loaded imp_mod) && has_orphans
267 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
269 combine old@(old_has_orphans, old_is_boot) new@(new_has_orphans, new_is_boot)
270 | old_is_boot = new -- Record the best is_boot info
273 -----------------------------------------------------
274 -- Loading the export list
275 -----------------------------------------------------
277 loadExports :: (Version, [ExportItem]) -> RnM d (Version, [(ModuleName,Avails)])
278 loadExports (vers, items)
279 = mapRn loadExport items `thenRn` \ avails_s ->
280 returnRn (vers, avails_s)
283 loadExport :: ExportItem -> RnM d (ModuleName, Avails)
284 loadExport (mod, entities)
285 = mapRn (load_entity mod) entities `thenRn` \ avails ->
286 returnRn (mod, avails)
288 load_entity mod (Avail occ)
289 = newGlobalName mod occ `thenRn` \ name ->
290 returnRn (Avail name)
291 load_entity mod (AvailTC occ occs)
292 = newGlobalName mod occ `thenRn` \ name ->
293 mapRn (newGlobalName mod) occs `thenRn` \ names ->
294 returnRn (AvailTC name names)
297 -----------------------------------------------------
298 -- Loading type/class/value decls
299 -----------------------------------------------------
303 -> [(Version, RdrNameTyClDecl)]
304 -> RnM d (NameEnv Version, DeclsMap)
305 loadDecls mod (decls_map, n_slurped) decls
306 = foldlRn (loadDecl mod) (emptyNameEnv, decls_map) decls `thenRn` \ (vers, decls_map') ->
307 returnRn (vers, (decls_map', n_slurped))
309 loadDecl mod (version_map, decls_map) (version, decl)
310 = getTyClDeclBinders mod decl `thenRn` \ (avail, sys_names) ->
312 full_avail = case avail of
314 AvailTC n ns -> AvailTC n (sys_names ++ ns)
315 main_name = availName full_avail
316 new_decls_map = extendNameEnvList decls_map stuff
317 stuff = [ (name, (full_avail, name==main_name, (mod, decl)))
318 | name <- availNames full_avail]
320 new_version_map = extendNameEnv version_map main_name version
322 returnRn (new_version_map, new_decls_map)
324 -----------------------------------------------------
325 -- Loading fixity decls
326 -----------------------------------------------------
328 loadFixDecls mod decls
329 = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
330 returnRn (mkNameEnv to_add)
332 mod_name = moduleName mod
334 loadFixDecl mod_name sig@(FixitySig rdr_name fixity loc)
335 = newGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
336 returnRn (name, fixity)
339 -----------------------------------------------------
340 -- Loading instance decls
341 -----------------------------------------------------
343 loadInstDecls :: Module
347 loadInstDecls mod (insts, n_slurped) decls
349 foldlRn (loadInstDecl mod) insts decls `thenRn` \ insts' ->
350 returnRn (insts', n_slurped)
353 loadInstDecl mod insts decl@(InstDecl inst_ty _ _ _ _)
354 = -- Find out what type constructors and classes are "gates" for the
355 -- instance declaration. If all these "gates" are slurped in then
356 -- we should slurp the instance decl too.
358 -- We *don't* want to count names in the context part as gates, though.
360 -- instance Foo a => Baz (T a) where ...
362 -- Here the gates are Baz and T, but *not* Foo.
364 munged_inst_ty = removeContext inst_ty
365 free_names = extractHsTyRdrNames munged_inst_ty
367 mapRn lookupIfaceName free_names `thenRn` \ gate_names ->
368 returnRn ((gate_names, (mod, decl)) `consBag` insts)
371 -- In interface files, the instance decls now look like
372 -- forall a. Foo a -> Baz (T a)
373 -- so we have to strip off function argument types as well
374 -- as the bit before the '=>' (which is always empty in interface files)
375 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
376 removeContext ty = removeFuns ty
378 removeFuns (HsFunTy _ ty) = removeFuns ty
382 -----------------------------------------------------
384 -----------------------------------------------------
386 loadRules :: Module -> IfaceRules
387 -> (Version, [RdrNameRuleDecl])
388 -> RnM d (Version, IfaceRules)
389 loadRules mod (rule_bag, n_slurped) (version, rules)
390 | null rules || opt_IgnoreIfacePragmas
391 = returnRn (version, (rule_bag, n_slurped))
394 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
395 returnRn (version, (rule_bag `unionBags` listToBag new_rules, n_slurped))
397 loadRule :: Module -> RdrNameRuleDecl -> RnM d (GatedDecl RdrNameRuleDecl)
398 -- "Gate" the rule simply by whether the rule variable is
399 -- needed. We can refine this later.
400 loadRule mod decl@(IfaceRule _ _ var _ _ src_loc)
401 = lookupIfaceName var `thenRn` \ var_name ->
402 returnRn ([var_name], (mod, decl))
405 -----------------------------------------------------
406 -- Loading Deprecations
407 -----------------------------------------------------
409 loadDeprecs :: Module -> IfaceDeprecs -> RnM d Deprecations
410 loadDeprecs m Nothing = returnRn NoDeprecs
411 loadDeprecs m (Just (Left txt)) = returnRn (DeprecAll txt)
412 loadDeprecs m (Just (Right prs)) = setModuleRn m $
413 foldlRn loadDeprec emptyNameEnv prs `thenRn` \ env ->
414 returnRn (DeprecSome env)
415 loadDeprec deprec_env (n, txt)
416 = lookupIfaceName n `thenRn` \ name ->
417 traceRn (text "Loaded deprecation(s) for" <+> ppr name <> colon <+> ppr txt) `thenRn_`
418 returnRn (extendNameEnv deprec_env name (name,txt))
422 %*********************************************************
424 \subsection{Getting binders out of a declaration}
426 %*********************************************************
428 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
429 It's used for both source code (from @availsFromDecl@) and interface files
432 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
433 are handled by the sourc-code specific stuff in @RnNames@.
435 *** See "THE NAMING STORY" in HsDecls ****
442 -> RnM d (AvailInfo, [Name]) -- The [Name] are the system names
445 getTyClDeclBinders mod (IfaceSig {tcdName = var, tcdLoc = src_loc})
446 = newTopBinder mod var src_loc `thenRn` \ var_name ->
447 returnRn (Avail var_name, [])
449 getTyClDeclBinders mod tycl_decl
450 = new_top_bndrs mod (tyClDeclNames tycl_decl) `thenRn` \ names@(main_name:_) ->
451 new_top_bndrs mod (tyClDeclSysNames tycl_decl) `thenRn` \ sys_names ->
452 returnRn (AvailTC main_name names, sys_names)
455 new_top_bndrs mod names_w_locs
456 = sequenceRn [newTopBinder mod name loc | (name,loc) <- names_w_locs]
460 %*********************************************************
462 \subsection{Reading an interface file}
464 %*********************************************************
467 findAndReadIface :: SDoc -> ModuleName
468 -> IsBootInterface -- True <=> Look for a .hi-boot file
469 -- False <=> Look for .hi file
470 -> RnM d (Either Message (Module, ParsedIface))
471 -- Nothing <=> file not found, or unreadable, or illegible
472 -- Just x <=> successfully found and parsed
474 findAndReadIface doc_str mod_name hi_boot_file
475 = traceRn trace_msg `thenRn_`
477 ioToRnM (findModule mod_name) `thenRn` \ maybe_found ->
480 Right (Just (wanted_mod,locn))
481 -> mkHiPath hi_boot_file locn `thenRn` \ file ->
482 readIface file `thenRn` \ read_result ->
484 Left bad -> returnRn (Left bad)
486 -> let read_mod = pi_mod iface
487 in warnCheckRn (wanted_mod == read_mod)
488 (hiModuleNameMismatchWarn wanted_mod
490 returnRn (Right (wanted_mod, iface))
492 other -> traceRn (ptext SLIT("...not found")) `thenRn_`
493 returnRn (Left (noIfaceErr mod_name hi_boot_file))
496 trace_msg = sep [hsep [ptext SLIT("Reading"),
497 if hi_boot_file then ptext SLIT("[boot]") else empty,
498 ptext SLIT("interface for"),
499 ppr mod_name <> semi],
500 nest 4 (ptext SLIT("reason:") <+> doc_str)]
502 mkHiPath hi_boot_file locn
504 ioToRnM_no_fail (doesFileExist hi_boot_ver_path) `thenRn` \ b ->
505 if b then returnRn hi_boot_ver_path
506 else returnRn hi_boot_path
507 | otherwise = returnRn hi_path
508 where (Just hi_path) = ml_hi_file locn
509 (hi_base, hi_suf) = splitFilename hi_path
510 hi_boot_path = hi_base ++ ".hi-boot"
511 hi_boot_ver_path = hi_base ++ ".hi-boot-" ++ cHscIfaceFileVersion
514 @readIface@ tries just the one file.
517 readIface :: String -> RnM d (Either Message ParsedIface)
518 -- Nothing <=> file not found, or unreadable, or illegible
519 -- Just x <=> successfully found and parsed
521 = --ioToRnM (putStrLn ("reading iface " ++ file_path)) `thenRn_`
522 traceRn (ptext SLIT("readIFace") <+> text file_path) `thenRn_`
524 ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
525 case read_result of {
526 Left io_error -> bale_out (text (show io_error)) ;
529 case parseIface contents init_parser_state of
530 POk _ (PIface iface) -> returnRn (Right iface)
531 PFailed err -> bale_out err
532 parse_result -> bale_out empty
533 -- This last case can happen if the interface file is (say) empty
534 -- in which case the parser thinks it looks like an IdInfo or
535 -- something like that. Just an artefact of the fact that the
536 -- parser is used for several purposes at once.
539 init_parser_state = PState{ bol = 0#, atbol = 1#,
542 loc = mkSrcLoc (mkFastString file_path) 1 }
544 bale_out err = returnRn (Left (badIfaceFile file_path err))
548 %*********************************************************
550 \subsection{Looking up fixities}
552 %*********************************************************
554 @lookupFixityRn@ has to be in RnIfaces (or RnHiFiles) because
555 it calls @loadHomeInterface@.
557 lookupFixity is a bit strange.
559 * Nested local fixity decls are put in the local fixity env, which we
560 find with getFixtyEnv
562 * Imported fixities are found in the HIT or PIT
564 * Top-level fixity decls in this module may be for Names that are
565 either Global (constructors, class operations)
566 or Local/Exported (everything else)
567 (See notes with RnNames.getLocalDeclBinders for why we have this split.)
568 We put them all in the local fixity environment
571 lookupFixityRn :: Name -> RnMS Fixity
573 = getModuleRn `thenRn` \ this_mod ->
574 if nameIsLocalOrFrom this_mod name
575 then -- It's defined in this module
576 getFixityEnv `thenRn` \ local_fix_env ->
577 returnRn (lookupLocalFixity local_fix_env name)
579 else -- It's imported
580 -- For imported names, we have to get their fixities by doing a loadHomeInterface,
581 -- and consulting the Ifaces that comes back from that, because the interface
582 -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
583 -- which exports a function 'f', which is defined in module B. Then B isn't loaded
584 -- right away (after all, it's possible that nothing from B will be used).
585 -- When we come across a use of 'f', we need to know its fixity, and it's then,
586 -- and only then, that we load B.hi. That is what's happening here.
587 loadHomeInterface doc name `thenRn` \ iface ->
588 returnRn (lookupNameEnv (mi_fixities iface) name `orElse` defaultFixity)
590 doc = ptext SLIT("Checking fixity for") <+> ppr name
594 %*********************************************************
598 %*********************************************************
601 noIfaceErr mod_name boot_file
602 = ptext SLIT("Could not find interface file for") <+> quotes (ppr mod_name)
603 -- We used to print the search path, but we can't do that
604 -- now, because it's hidden inside the finder.
605 -- Maybe the finder should expose more functions.
607 badIfaceFile file err
608 = vcat [ptext SLIT("Bad interface file:") <+> text file,
611 hiModuleNameMismatchWarn :: Module -> Module -> Message
612 hiModuleNameMismatchWarn requested_mod read_mod =
613 hsep [ ptext SLIT("Something is amiss; requested module name")
614 , ppr (moduleName requested_mod)
615 , ptext SLIT("differs from name found in the interface file")
619 warnRedundantSourceImport mod_name
620 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
621 <+> quotes (ppr mod_name)
624 = ptext SLIT("Importing my own interface: module") <+> ppr mod