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 CmdLineOpts ( opt_IgnoreIfacePragmas )
21 import HscTypes ( ModuleLocation(..),
22 ModIface(..), emptyModIface,
23 VersionInfo(..), ImportedModuleInfo,
25 ImportVersion, WhetherHasOrphans, IsBootInterface,
26 DeclsMap, GatedDecl, IfaceInsts, IfaceRules,
27 AvailInfo, GenAvailInfo(..), Avails, Deprecations(..)
29 import HsSyn ( TyClDecl(..), InstDecl(..),
30 HsType(..), FixitySig(..), RuleDecl(..),
31 tyClDeclNames, tyClDeclSysNames
33 import RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl,
36 import BasicTypes ( Version, defaultFixity )
39 import ParseIface ( parseIface, IfaceStuff(..) )
41 import Name ( Name {-instance NamedThing-}, nameOccName,
42 nameModule, isLocalName, nameIsLocalOrFrom,
45 import Name ( mkNameEnv, extendNameEnv )
46 import Module ( Module,
47 moduleName, isHomeModule,
48 ModuleName, WhereFrom(..),
49 extendModuleEnv, mkVanillaModule
51 import RdrName ( RdrName, rdrNameOcc )
52 import SrcLoc ( mkSrcLoc )
53 import Maybes ( maybeToBool, orElse )
54 import StringBuffer ( hGetStringBuffer )
55 import FastString ( mkFastString )
56 import ErrUtils ( Message )
57 import Finder ( findModule )
68 %*********************************************************
70 \subsection{Loading a new interface file}
72 %*********************************************************
75 loadHomeInterface :: SDoc -> Name -> RnM d ModIface
76 loadHomeInterface doc_str name
77 = ASSERT2( not (isLocalName name), ppr name <+> parens doc_str )
78 loadInterface doc_str (moduleName (nameModule name)) ImportBySystem
80 loadOrphanModules :: [ModuleName] -> RnM d ()
81 loadOrphanModules mods
82 | null mods = returnRn ()
83 | otherwise = traceRn (text "Loading orphan modules:" <+>
84 fsep (map ppr mods)) `thenRn_`
85 mapRn_ load mods `thenRn_`
88 load mod = loadInterface (mk_doc mod) mod ImportBySystem
89 mk_doc mod = ppr mod <+> ptext SLIT("is a orphan-instance module")
91 loadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d ModIface
92 loadInterface doc mod from
93 = tryLoadInterface doc mod from `thenRn` \ (ifaces, maybe_err) ->
95 Nothing -> returnRn ifaces
96 Just err -> failWithRn ifaces err
98 tryLoadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d (ModIface, Maybe Message)
99 -- Returns (Just err) if an error happened
100 -- It *doesn't* add an error to the monad, because sometimes it's ok to fail...
101 -- Specifically, when we read the usage information from an interface file,
102 -- we try to read the interfaces it mentions. But it's OK to fail; perhaps
103 -- the module has changed, and that interface is no longer used.
105 -- tryLoadInterface guarantees to return with iImpModInfo m --> (..., True)
106 -- (If the load fails, we plug in a vanilla placeholder)
107 tryLoadInterface doc_str mod_name from
108 = getHomeIfaceTableRn `thenRn` \ hit ->
109 getModuleRn `thenRn` \ this_mod ->
110 getIfacesRn `thenRn` \ ifaces@(Ifaces { iPIT = pit }) ->
112 -- CHECK WHETHER WE HAVE IT ALREADY
113 case lookupIfaceByModName hit pit mod_name of {
114 Just iface | case from of
115 ImportByUser -> not (mi_boot iface)
116 ImportByUserSource -> mi_boot iface
117 ImportBySystem -> True
118 -> returnRn (iface, Nothing) ; -- Already loaded
119 -- The not (mi_boot iface) test checks that the already-loaded
120 -- interface isn't a boot iface. This can conceivably happen,
121 -- if the version checking happened to load a boot interface
122 -- before we got to real imports.
126 mod_map = iImpModInfo ifaces
127 mod_info = lookupFM mod_map mod_name
130 = case (from, mod_info) of
131 (ImportByUser, _) -> False -- Not hi-boot
132 (ImportByUserSource, _) -> True -- hi-boot
133 (ImportBySystem, Just (_, is_boot)) -> is_boot
134 (ImportBySystem, Nothing) -> False
135 -- We're importing a module we know absolutely
136 -- nothing about, so we assume it's from
137 -- another package, where we aren't doing
138 -- dependency tracking. So it won't be a hi-boot file.
140 redundant_source_import
141 = case (from, mod_info) of
142 (ImportByUserSource, Just (_,False)) -> True
146 -- Issue a warning for a redundant {- SOURCE -} import
147 -- NB that we arrange to read all the ordinary imports before
148 -- any of the {- SOURCE -} imports
149 warnCheckRn (not redundant_source_import)
150 (warnRedundantSourceImport mod_name) `thenRn_`
152 -- Check that we aren't importing ourselves.
153 -- That only happens in Rename.checkOldIface,
154 -- which doesn't call tryLoadInterface
155 warnCheckRn (moduleName this_mod /= mod_name)
156 (warnSelfImport this_mod) `thenRn_`
158 -- READ THE MODULE IN
159 findAndReadIface doc_str mod_name hi_boot_file `thenRn` \ read_result ->
160 case read_result of {
161 Left err -> -- Not found, so add an empty export env to the Ifaces map
162 -- so that we don't look again
164 fake_mod = mkVanillaModule mod_name
165 fake_iface = emptyModIface fake_mod
166 new_ifaces = ifaces { iPIT = extendModuleEnv pit fake_mod fake_iface }
168 setIfacesRn new_ifaces `thenRn_`
169 returnRn (fake_iface, Just err) ;
172 Right (mod, iface) ->
174 -- LOAD IT INTO Ifaces
176 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
177 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
178 -- If we do loadExport first the wrong info gets into the cache (unless we
179 -- explicitly tag each export which seems a bit of a bore)
182 -- Sanity check. If we're system-importing a module we know nothing at all
183 -- about, it should be from a different package to this one
184 WARN( not (maybeToBool mod_info) &&
185 case from of { ImportBySystem -> True; other -> False } &&
189 loadDecls mod (iDecls ifaces) (pi_decls iface) `thenRn` \ (decls_vers, new_decls) ->
190 loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ (rule_vers, new_rules) ->
191 loadInstDecls mod (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
192 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
193 loadFixDecls mod (pi_fixity iface) `thenRn` \ fix_env ->
194 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
196 version = VersionInfo { vers_module = pi_vers iface,
197 vers_exports = export_vers,
198 vers_rules = rule_vers,
199 vers_decls = decls_vers }
201 -- For an explicit user import, add to mod_map info about
202 -- the things the imported module depends on, extracted
203 -- from its usage info; and delete the module itself, which is now in the PIT
204 mod_map1 = case from of
205 ImportByUser -> addModDeps mod is_loaded (pi_usages iface) mod_map
207 mod_map2 = delFromFM mod_map1 mod_name
209 this_mod_name = moduleName this_mod
210 is_loaded m = m == this_mod_name
211 || maybeToBool (lookupIfaceByModName hit pit m)
212 -- We treat the currently-being-compiled module as 'loaded' because
213 -- even though it isn't yet in the HIT or PIT; otherwise it gets
214 -- put into iImpModInfo, and then spat out into its own interface
215 -- file as a dependency
217 -- Now add info about this module to the PIT
218 has_orphans = pi_orphan iface
219 new_pit = extendModuleEnv pit mod mod_iface
220 mod_iface = ModIface { mi_module = mod, mi_version = version,
221 mi_orphan = has_orphans, mi_boot = hi_boot_file,
223 mi_fixities = fix_env, mi_deprecs = deprec_env,
224 mi_usages = [], -- Will be filled in later
225 mi_decls = panic "No mi_decls in PIT",
226 mi_globals = mkIfaceGlobalRdrEnv avails
229 new_ifaces = ifaces { iPIT = new_pit,
233 iImpModInfo = mod_map2 }
235 setIfacesRn new_ifaces `thenRn_`
236 returnRn (mod_iface, Nothing)
239 -----------------------------------------------------
240 -- Adding module dependencies from the
241 -- import decls in the interface file
242 -----------------------------------------------------
245 -> (ModuleName -> Bool) -- True for modules that are already loaded
247 -> ImportedModuleInfo -> ImportedModuleInfo
248 -- (addModDeps M ivs deps)
249 -- We are importing module M, and M.hi contains 'import' decls given by ivs
250 addModDeps mod is_loaded new_deps mod_deps
251 = foldr add mod_deps filtered_new_deps
253 -- Don't record dependencies when importing a module from another package
254 -- Except for its descendents which contain orphans,
255 -- and in that case, forget about the boot indicator
256 filtered_new_deps :: [(ModuleName, (WhetherHasOrphans, IsBootInterface))]
258 | isHomeModule mod = [ (imp_mod, (has_orphans, is_boot))
259 | (imp_mod, has_orphans, is_boot, _) <- new_deps,
260 not (is_loaded imp_mod)
262 | otherwise = [ (imp_mod, (True, False))
263 | (imp_mod, has_orphans, _, _) <- new_deps,
264 not (is_loaded imp_mod) && has_orphans
266 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
268 combine old@(old_has_orphans, old_is_boot) new@(new_has_orphans, new_is_boot)
269 | old_is_boot = new -- Record the best is_boot info
272 -----------------------------------------------------
273 -- Loading the export list
274 -----------------------------------------------------
276 loadExports :: (Version, [ExportItem]) -> RnM d (Version, [(ModuleName,Avails)])
277 loadExports (vers, items)
278 = mapRn loadExport items `thenRn` \ avails_s ->
279 returnRn (vers, avails_s)
282 loadExport :: ExportItem -> RnM d (ModuleName, Avails)
283 loadExport (mod, entities)
284 = mapRn (load_entity mod) entities `thenRn` \ avails ->
285 returnRn (mod, avails)
287 load_entity mod (Avail occ)
288 = newGlobalName mod occ `thenRn` \ name ->
289 returnRn (Avail name)
290 load_entity mod (AvailTC occ occs)
291 = newGlobalName mod occ `thenRn` \ name ->
292 mapRn (newGlobalName mod) occs `thenRn` \ names ->
293 returnRn (AvailTC name names)
296 -----------------------------------------------------
297 -- Loading type/class/value decls
298 -----------------------------------------------------
302 -> [(Version, RdrNameTyClDecl)]
303 -> RnM d (NameEnv Version, DeclsMap)
304 loadDecls mod (decls_map, n_slurped) decls
305 = foldlRn (loadDecl mod) (emptyNameEnv, decls_map) decls `thenRn` \ (vers, decls_map') ->
306 returnRn (vers, (decls_map', n_slurped))
308 loadDecl mod (version_map, decls_map) (version, decl)
309 = getTyClDeclBinders mod decl `thenRn` \ (avail, sys_names) ->
311 full_avail = case avail of
313 AvailTC n ns -> AvailTC n (sys_names ++ ns)
314 main_name = availName full_avail
315 new_decls_map = extendNameEnvList decls_map stuff
316 stuff = [ (name, (full_avail, name==main_name, (mod, decl)))
317 | name <- availNames full_avail]
319 new_version_map = extendNameEnv version_map main_name version
321 returnRn (new_version_map, new_decls_map)
323 -----------------------------------------------------
324 -- Loading fixity decls
325 -----------------------------------------------------
327 loadFixDecls mod decls
328 = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
329 returnRn (mkNameEnv to_add)
331 mod_name = moduleName mod
333 loadFixDecl mod_name sig@(FixitySig rdr_name fixity loc)
334 = newGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
335 returnRn (name, fixity)
338 -----------------------------------------------------
339 -- Loading instance decls
340 -----------------------------------------------------
342 loadInstDecls :: Module
346 loadInstDecls mod (insts, n_slurped) decls
348 foldlRn (loadInstDecl mod) insts decls `thenRn` \ insts' ->
349 returnRn (insts', n_slurped)
352 loadInstDecl mod insts decl@(InstDecl inst_ty _ _ _ _)
353 = -- Find out what type constructors and classes are "gates" for the
354 -- instance declaration. If all these "gates" are slurped in then
355 -- we should slurp the instance decl too.
357 -- We *don't* want to count names in the context part as gates, though.
359 -- instance Foo a => Baz (T a) where ...
361 -- Here the gates are Baz and T, but *not* Foo.
363 munged_inst_ty = removeContext inst_ty
364 free_names = extractHsTyRdrNames munged_inst_ty
366 mapRn lookupIfaceName free_names `thenRn` \ gate_names ->
367 returnRn ((gate_names, (mod, decl)) `consBag` insts)
370 -- In interface files, the instance decls now look like
371 -- forall a. Foo a -> Baz (T a)
372 -- so we have to strip off function argument types as well
373 -- as the bit before the '=>' (which is always empty in interface files)
374 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
375 removeContext ty = removeFuns ty
377 removeFuns (HsFunTy _ ty) = removeFuns ty
381 -----------------------------------------------------
383 -----------------------------------------------------
385 loadRules :: Module -> IfaceRules
386 -> (Version, [RdrNameRuleDecl])
387 -> RnM d (Version, IfaceRules)
388 loadRules mod (rule_bag, n_slurped) (version, rules)
389 | null rules || opt_IgnoreIfacePragmas
390 = returnRn (version, (rule_bag, n_slurped))
393 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
394 returnRn (version, (rule_bag `unionBags` listToBag new_rules, n_slurped))
396 loadRule :: Module -> RdrNameRuleDecl -> RnM d (GatedDecl RdrNameRuleDecl)
397 -- "Gate" the rule simply by whether the rule variable is
398 -- needed. We can refine this later.
399 loadRule mod decl@(IfaceRule _ _ var _ _ src_loc)
400 = lookupIfaceName var `thenRn` \ var_name ->
401 returnRn ([var_name], (mod, decl))
404 -----------------------------------------------------
405 -- Loading Deprecations
406 -----------------------------------------------------
408 loadDeprecs :: Module -> IfaceDeprecs -> RnM d Deprecations
409 loadDeprecs m Nothing = returnRn NoDeprecs
410 loadDeprecs m (Just (Left txt)) = returnRn (DeprecAll txt)
411 loadDeprecs m (Just (Right prs)) = setModuleRn m $
412 foldlRn loadDeprec emptyNameEnv prs `thenRn` \ env ->
413 returnRn (DeprecSome env)
414 loadDeprec deprec_env (n, txt)
415 = lookupIfaceName n `thenRn` \ name ->
416 traceRn (text "Loaded deprecation(s) for" <+> ppr name <> colon <+> ppr txt) `thenRn_`
417 returnRn (extendNameEnv deprec_env name (name,txt))
421 %*********************************************************
423 \subsection{Getting binders out of a declaration}
425 %*********************************************************
427 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
428 It's used for both source code (from @availsFromDecl@) and interface files
431 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
432 are handled by the sourc-code specific stuff in @RnNames@.
434 *** See "THE NAMING STORY" in HsDecls ****
441 -> RnM d (AvailInfo, [Name]) -- The [Name] are the system names
444 getTyClDeclBinders mod (IfaceSig {tcdName = var, tcdLoc = src_loc})
445 = newTopBinder mod var src_loc `thenRn` \ var_name ->
446 returnRn (Avail var_name, [])
448 getTyClDeclBinders mod tycl_decl
449 = new_top_bndrs mod (tyClDeclNames tycl_decl) `thenRn` \ names@(main_name:_) ->
450 new_top_bndrs mod (tyClDeclSysNames tycl_decl) `thenRn` \ sys_names ->
451 returnRn (AvailTC main_name names, sys_names)
454 new_top_bndrs mod names_w_locs
455 = sequenceRn [newTopBinder mod name loc | (name,loc) <- names_w_locs]
459 %*********************************************************
461 \subsection{Reading an interface file}
463 %*********************************************************
466 findAndReadIface :: SDoc -> ModuleName
467 -> IsBootInterface -- True <=> Look for a .hi-boot file
468 -- False <=> Look for .hi file
469 -> RnM d (Either Message (Module, ParsedIface))
470 -- Nothing <=> file not found, or unreadable, or illegible
471 -- Just x <=> successfully found and parsed
473 findAndReadIface doc_str mod_name hi_boot_file
474 = traceRn trace_msg `thenRn_`
476 ioToRnM (findModule mod_name) `thenRn` \ maybe_found ->
479 Right (Just (wanted_mod,locn))
480 -> mkHiPath hi_boot_file locn `thenRn` \ file ->
481 readIface file `thenRn` \ read_result ->
483 Left bad -> returnRn (Left bad)
485 -> let read_mod = pi_mod iface
486 in warnCheckRn (wanted_mod == read_mod)
487 (hiModuleNameMismatchWarn wanted_mod
489 returnRn (Right (wanted_mod, iface))
491 other -> traceRn (ptext SLIT("...not found")) `thenRn_`
492 returnRn (Left (noIfaceErr mod_name hi_boot_file))
495 trace_msg = sep [hsep [ptext SLIT("Reading"),
496 if hi_boot_file then ptext SLIT("[boot]") else empty,
497 ptext SLIT("interface for"),
498 ppr mod_name <> semi],
499 nest 4 (ptext SLIT("reason:") <+> doc_str)]
501 mkHiPath hi_boot_file locn
503 ioToRnM_no_fail (doesFileExist hi_boot_ver_path) `thenRn` \ b ->
504 if b then returnRn hi_boot_ver_path
505 else returnRn hi_boot_path
506 | otherwise = returnRn hi_path
507 where (Just hi_path) = ml_hi_file locn
508 hi_boot_path = hi_path ++ "-boot"
509 hi_boot_ver_path = hi_path ++ "-boot-" ++ cHscIfaceFileVersion
512 @readIface@ tries just the one file.
515 readIface :: String -> RnM d (Either Message ParsedIface)
516 -- Nothing <=> file not found, or unreadable, or illegible
517 -- Just x <=> successfully found and parsed
519 = --ioToRnM (putStrLn ("reading iface " ++ file_path)) `thenRn_`
520 traceRn (ptext SLIT("readIFace") <+> text file_path) `thenRn_`
522 ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
523 case read_result of {
524 Left io_error -> bale_out (text (show io_error)) ;
527 case parseIface contents init_parser_state of
528 POk _ (PIface iface) -> returnRn (Right iface)
529 PFailed err -> bale_out err
530 parse_result -> bale_out empty
531 -- This last case can happen if the interface file is (say) empty
532 -- in which case the parser thinks it looks like an IdInfo or
533 -- something like that. Just an artefact of the fact that the
534 -- parser is used for several purposes at once.
537 init_parser_state = PState{ bol = 0#, atbol = 1#,
540 loc = mkSrcLoc (mkFastString file_path) 1 }
542 bale_out err = returnRn (Left (badIfaceFile file_path err))
546 %*********************************************************
548 \subsection{Looking up fixities}
550 %*********************************************************
552 @lookupFixityRn@ has to be in RnIfaces (or RnHiFiles) because
553 it calls @loadHomeInterface@.
555 lookupFixity is a bit strange.
557 * Nested local fixity decls are put in the local fixity env, which we
558 find with getFixtyEnv
560 * Imported fixities are found in the HIT or PIT
562 * Top-level fixity decls in this module may be for Names that are
563 either Global (constructors, class operations)
564 or Local/Exported (everything else)
565 (See notes with RnNames.getLocalDeclBinders for why we have this split.)
566 We put them all in the local fixity environment
569 lookupFixityRn :: Name -> RnMS Fixity
571 = getModuleRn `thenRn` \ this_mod ->
572 if nameIsLocalOrFrom this_mod name
573 then -- It's defined in this module
574 getFixityEnv `thenRn` \ local_fix_env ->
575 returnRn (lookupLocalFixity local_fix_env name)
577 else -- It's imported
578 -- For imported names, we have to get their fixities by doing a loadHomeInterface,
579 -- and consulting the Ifaces that comes back from that, because the interface
580 -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
581 -- which exports a function 'f', which is defined in module B. Then B isn't loaded
582 -- right away (after all, it's possible that nothing from B will be used).
583 -- When we come across a use of 'f', we need to know its fixity, and it's then,
584 -- and only then, that we load B.hi. That is what's happening here.
585 loadHomeInterface doc name `thenRn` \ iface ->
586 returnRn (lookupNameEnv (mi_fixities iface) name `orElse` defaultFixity)
588 doc = ptext SLIT("Checking fixity for") <+> ppr name
592 %*********************************************************
596 %*********************************************************
599 noIfaceErr mod_name boot_file
600 = ptext SLIT("Could not find interface file for") <+> quotes (ppr mod_name)
601 -- We used to print the search path, but we can't do that
602 -- now, because it's hidden inside the finder.
603 -- Maybe the finder should expose more functions.
605 badIfaceFile file err
606 = vcat [ptext SLIT("Bad interface file:") <+> text file,
609 hiModuleNameMismatchWarn :: Module -> Module -> Message
610 hiModuleNameMismatchWarn requested_mod read_mod =
611 hsep [ ptext SLIT("Something is amiss; requested module name")
612 , ppr (moduleName requested_mod)
613 , ptext SLIT("differs from name found in the interface file")
617 warnRedundantSourceImport mod_name
618 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
619 <+> quotes (ppr mod_name)
622 = ptext SLIT("Importing my own interface: module") <+> ppr mod