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 )
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
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 `thenRn` \ read_result ->
162 case read_result of {
163 Left err -> -- Not found, so add an empty export env to the Ifaces map
164 -- so that we don't look again
166 fake_mod = mkVanillaModule mod_name
167 fake_iface = emptyModIface fake_mod
168 new_ifaces = ifaces { iPIT = extendModuleEnv pit fake_mod fake_iface }
170 setIfacesRn new_ifaces `thenRn_`
171 returnRn (fake_iface, Just err) ;
174 Right (mod, iface) ->
176 -- LOAD IT INTO Ifaces
178 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
179 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
180 -- If we do loadExport first the wrong info gets into the cache (unless we
181 -- explicitly tag each export which seems a bit of a bore)
184 -- Sanity check. If we're system-importing a module we know nothing at all
185 -- about, it should be from a different package to this one
186 WARN( not (maybeToBool mod_info) &&
187 case from of { ImportBySystem -> True; other -> False } &&
191 loadDecls mod (iDecls ifaces) (pi_decls iface) `thenRn` \ (decls_vers, new_decls) ->
192 loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ (rule_vers, new_rules) ->
193 loadInstDecls mod (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
194 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
195 loadFixDecls mod (pi_fixity iface) `thenRn` \ fix_env ->
196 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
198 version = VersionInfo { vers_module = pi_vers iface,
199 vers_exports = export_vers,
200 vers_rules = rule_vers,
201 vers_decls = decls_vers }
203 -- For an explicit user import, add to mod_map info about
204 -- the things the imported module depends on, extracted
205 -- from its usage info; and delete the module itself, which is now in the PIT
206 mod_map1 = case from of
207 ImportByUser -> addModDeps mod is_loaded (pi_usages iface) mod_map
209 mod_map2 = delFromFM mod_map1 mod_name
211 this_mod_name = moduleName this_mod
212 is_loaded m = m == this_mod_name
213 || maybeToBool (lookupIfaceByModName hit pit m)
214 -- We treat the currently-being-compiled module as 'loaded' because
215 -- even though it isn't yet in the HIT or PIT; otherwise it gets
216 -- put into iImpModInfo, and then spat out into its own interface
217 -- file as a dependency
219 -- Now add info about this module to the PIT
220 has_orphans = pi_orphan iface
221 new_pit = extendModuleEnv pit mod mod_iface
222 mod_iface = ModIface { mi_module = mod, mi_version = version,
223 mi_orphan = has_orphans, mi_boot = hi_boot_file,
225 mi_fixities = fix_env, mi_deprecs = deprec_env,
226 mi_usages = [], -- Will be filled in later
227 mi_decls = panic "No mi_decls in PIT",
228 mi_globals = mkIfaceGlobalRdrEnv avails
231 new_ifaces = ifaces { iPIT = new_pit,
235 iImpModInfo = mod_map2 }
237 setIfacesRn new_ifaces `thenRn_`
238 returnRn (mod_iface, Nothing)
241 -----------------------------------------------------
242 -- Adding module dependencies from the
243 -- import decls in the interface file
244 -----------------------------------------------------
247 -> (ModuleName -> Bool) -- True for modules that are already loaded
249 -> ImportedModuleInfo -> ImportedModuleInfo
250 -- (addModDeps M ivs deps)
251 -- We are importing module M, and M.hi contains 'import' decls given by ivs
252 addModDeps mod is_loaded new_deps mod_deps
253 = foldr add mod_deps filtered_new_deps
255 -- Don't record dependencies when importing a module from another package
256 -- Except for its descendents which contain orphans,
257 -- and in that case, forget about the boot indicator
258 filtered_new_deps :: [(ModuleName, (WhetherHasOrphans, IsBootInterface))]
260 | isHomeModule mod = [ (imp_mod, (has_orphans, is_boot))
261 | (imp_mod, has_orphans, is_boot, _) <- new_deps,
262 not (is_loaded imp_mod)
264 | otherwise = [ (imp_mod, (True, False))
265 | (imp_mod, has_orphans, _, _) <- new_deps,
266 not (is_loaded imp_mod) && has_orphans
268 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
270 combine old@(old_has_orphans, old_is_boot) new@(new_has_orphans, new_is_boot)
271 | old_is_boot = new -- Record the best is_boot info
274 -----------------------------------------------------
275 -- Loading the export list
276 -----------------------------------------------------
278 loadExports :: (Version, [ExportItem]) -> RnM d (Version, [(ModuleName,Avails)])
279 loadExports (vers, items)
280 = mapRn loadExport items `thenRn` \ avails_s ->
281 returnRn (vers, avails_s)
284 loadExport :: ExportItem -> RnM d (ModuleName, Avails)
285 loadExport (mod, entities)
286 = mapRn (load_entity mod) entities `thenRn` \ avails ->
287 returnRn (mod, avails)
289 load_entity mod (Avail occ)
290 = newGlobalName mod occ `thenRn` \ name ->
291 returnRn (Avail name)
292 load_entity mod (AvailTC occ occs)
293 = newGlobalName mod occ `thenRn` \ name ->
294 mapRn (newGlobalName mod) occs `thenRn` \ names ->
295 returnRn (AvailTC name names)
298 -----------------------------------------------------
299 -- Loading type/class/value decls
300 -----------------------------------------------------
304 -> [(Version, RdrNameTyClDecl)]
305 -> RnM d (NameEnv Version, DeclsMap)
306 loadDecls mod (decls_map, n_slurped) decls
307 = foldlRn (loadDecl mod) (emptyNameEnv, decls_map) decls `thenRn` \ (vers, decls_map') ->
308 returnRn (vers, (decls_map', n_slurped))
310 loadDecl mod (version_map, decls_map) (version, decl)
311 = getTyClDeclBinders mod decl `thenRn` \ (avail, sys_names) ->
313 full_avail = case avail of
315 AvailTC n ns -> AvailTC n (sys_names ++ ns)
316 main_name = availName full_avail
317 new_decls_map = extendNameEnvList decls_map stuff
318 stuff = [ (name, (full_avail, name==main_name, (mod, decl)))
319 | name <- availNames full_avail]
321 new_version_map = extendNameEnv version_map main_name version
323 returnRn (new_version_map, new_decls_map)
325 -----------------------------------------------------
326 -- Loading fixity decls
327 -----------------------------------------------------
329 loadFixDecls mod decls
330 = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
331 returnRn (mkNameEnv to_add)
333 mod_name = moduleName mod
335 loadFixDecl mod_name sig@(FixitySig rdr_name fixity loc)
336 = newGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
337 returnRn (name, fixity)
340 -----------------------------------------------------
341 -- Loading instance decls
342 -----------------------------------------------------
344 loadInstDecls :: Module
348 loadInstDecls mod (insts, n_slurped) decls
350 foldlRn (loadInstDecl mod) insts decls `thenRn` \ insts' ->
351 returnRn (insts', n_slurped)
354 loadInstDecl mod insts decl@(InstDecl inst_ty _ _ _ _)
355 = -- Find out what type constructors and classes are "gates" for the
356 -- instance declaration. If all these "gates" are slurped in then
357 -- we should slurp the instance decl too.
359 -- We *don't* want to count names in the context part as gates, though.
361 -- instance Foo a => Baz (T a) where ...
363 -- Here the gates are Baz and T, but *not* Foo.
365 munged_inst_ty = removeContext inst_ty
366 free_names = extractHsTyRdrNames munged_inst_ty
368 mapRn lookupIfaceName free_names `thenRn` \ gate_names ->
369 returnRn ((gate_names, (mod, decl)) `consBag` insts)
372 -- In interface files, the instance decls now look like
373 -- forall a. Foo a -> Baz (T a)
374 -- so we have to strip off function argument types as well
375 -- as the bit before the '=>' (which is always empty in interface files)
376 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
377 removeContext ty = removeFuns ty
379 removeFuns (HsFunTy _ ty) = removeFuns ty
383 -----------------------------------------------------
385 -----------------------------------------------------
387 loadRules :: Module -> IfaceRules
388 -> (Version, [RdrNameRuleDecl])
389 -> RnM d (Version, IfaceRules)
390 loadRules mod (rule_bag, n_slurped) (version, rules)
391 | null rules || opt_IgnoreIfacePragmas
392 = returnRn (version, (rule_bag, n_slurped))
395 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
396 returnRn (version, (rule_bag `unionBags` listToBag new_rules, n_slurped))
398 loadRule :: Module -> RdrNameRuleDecl -> RnM d (GatedDecl RdrNameRuleDecl)
399 -- "Gate" the rule simply by whether the rule variable is
400 -- needed. We can refine this later.
401 loadRule mod decl@(IfaceRule _ _ var _ _ src_loc)
402 = lookupIfaceName var `thenRn` \ var_name ->
403 returnRn ([var_name], (mod, decl))
406 -----------------------------------------------------
407 -- Loading Deprecations
408 -----------------------------------------------------
410 loadDeprecs :: Module -> IfaceDeprecs -> RnM d Deprecations
411 loadDeprecs m Nothing = returnRn NoDeprecs
412 loadDeprecs m (Just (Left txt)) = returnRn (DeprecAll txt)
413 loadDeprecs m (Just (Right prs)) = setModuleRn m $
414 foldlRn loadDeprec emptyNameEnv prs `thenRn` \ env ->
415 returnRn (DeprecSome env)
416 loadDeprec deprec_env (n, txt)
417 = lookupIfaceName n `thenRn` \ name ->
418 traceRn (text "Loaded deprecation(s) for" <+> ppr name <> colon <+> ppr txt) `thenRn_`
419 returnRn (extendNameEnv deprec_env name (name,txt))
423 %*********************************************************
425 \subsection{Getting binders out of a declaration}
427 %*********************************************************
429 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
430 It's used for both source code (from @availsFromDecl@) and interface files
433 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
434 are handled by the sourc-code specific stuff in @RnNames@.
436 *** See "THE NAMING STORY" in HsDecls ****
443 -> RnM d (AvailInfo, [Name]) -- The [Name] are the system names
446 getTyClDeclBinders mod (IfaceSig {tcdName = var, tcdLoc = src_loc})
447 = newTopBinder mod var src_loc `thenRn` \ var_name ->
448 returnRn (Avail var_name, [])
450 getTyClDeclBinders mod tycl_decl
451 = new_top_bndrs mod (tyClDeclNames tycl_decl) `thenRn` \ names@(main_name:_) ->
452 new_top_bndrs mod (tyClDeclSysNames tycl_decl) `thenRn` \ sys_names ->
453 returnRn (AvailTC main_name names, sys_names)
456 new_top_bndrs mod names_w_locs
457 = sequenceRn [newTopBinder mod name loc | (name,loc) <- names_w_locs]
461 %*********************************************************
463 \subsection{Reading an interface file}
465 %*********************************************************
468 findAndReadIface :: SDoc -> ModuleName
469 -> IsBootInterface -- True <=> Look for a .hi-boot file
470 -- False <=> Look for .hi file
471 -> RnM d (Either Message (Module, ParsedIface))
472 -- Nothing <=> file not found, or unreadable, or illegible
473 -- Just x <=> successfully found and parsed
475 findAndReadIface doc_str mod_name hi_boot_file
476 = traceRn trace_msg `thenRn_`
478 ioToRnM (findModule mod_name) `thenRn` \ maybe_found ->
481 Right (Just (wanted_mod,locn))
482 -> mkHiPath hi_boot_file locn `thenRn` \ file ->
483 readIface file `thenRn` \ read_result ->
485 Left bad -> returnRn (Left bad)
487 -> let read_mod = pi_mod iface
488 in warnCheckRn (wanted_mod == read_mod)
489 (hiModuleNameMismatchWarn wanted_mod
491 returnRn (Right (wanted_mod, iface))
493 other -> traceRn (ptext SLIT("...not found")) `thenRn_`
494 returnRn (Left (noIfaceErr mod_name hi_boot_file))
497 trace_msg = sep [hsep [ptext SLIT("Reading"),
498 if hi_boot_file then ptext SLIT("[boot]") else empty,
499 ptext SLIT("interface for"),
500 ppr mod_name <> semi],
501 nest 4 (ptext SLIT("reason:") <+> doc_str)]
503 mkHiPath hi_boot_file locn
505 ioToRnM_no_fail (doesFileExist hi_boot_ver_path) `thenRn` \ b ->
506 if b then returnRn hi_boot_ver_path
507 else returnRn hi_boot_path
508 | otherwise = returnRn hi_path
509 where (Just hi_path) = ml_hi_file locn
510 (hi_base, hi_suf) = splitFilename hi_path
511 hi_boot_path = hi_base ++ ".hi-boot"
512 hi_boot_ver_path = hi_base ++ ".hi-boot-" ++ cHscIfaceFileVersion
515 @readIface@ tries just the one file.
518 readIface :: String -> RnM d (Either Message ParsedIface)
519 -- Nothing <=> file not found, or unreadable, or illegible
520 -- Just x <=> successfully found and parsed
522 = --ioToRnM (putStrLn ("reading iface " ++ file_path)) `thenRn_`
523 traceRn (ptext SLIT("readIFace") <+> text file_path) `thenRn_`
525 ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
526 case read_result of {
527 Left io_error -> bale_out (text (show io_error)) ;
530 case parseIface contents init_parser_state of
531 POk _ iface -> returnRn (Right iface)
532 PFailed err -> bale_out err
535 init_parser_state = PState{ bol = 0#, atbol = 1#,
538 loc = mkSrcLoc (mkFastString file_path) 1 }
540 bale_out err = returnRn (Left (badIfaceFile file_path err))
544 %*********************************************************
546 \subsection{Looking up fixities}
548 %*********************************************************
550 @lookupFixityRn@ has to be in RnIfaces (or RnHiFiles) because
551 it calls @loadHomeInterface@.
553 lookupFixity is a bit strange.
555 * Nested local fixity decls are put in the local fixity env, which we
556 find with getFixtyEnv
558 * Imported fixities are found in the HIT or PIT
560 * Top-level fixity decls in this module may be for Names that are
561 either Global (constructors, class operations)
562 or Local/Exported (everything else)
563 (See notes with RnNames.getLocalDeclBinders for why we have this split.)
564 We put them all in the local fixity environment
567 lookupFixityRn :: Name -> RnMS Fixity
569 = getModuleRn `thenRn` \ this_mod ->
570 if nameIsLocalOrFrom this_mod name
571 then -- It's defined in this module
572 getFixityEnv `thenRn` \ local_fix_env ->
573 returnRn (lookupLocalFixity local_fix_env name)
575 else -- It's imported
576 -- For imported names, we have to get their fixities by doing a loadHomeInterface,
577 -- and consulting the Ifaces that comes back from that, because the interface
578 -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
579 -- which exports a function 'f', which is defined in module B. Then B isn't loaded
580 -- right away (after all, it's possible that nothing from B will be used).
581 -- When we come across a use of 'f', we need to know its fixity, and it's then,
582 -- and only then, that we load B.hi. That is what's happening here.
583 loadHomeInterface doc name `thenRn` \ iface ->
584 returnRn (lookupNameEnv (mi_fixities iface) name `orElse` defaultFixity)
586 doc = ptext SLIT("Checking fixity for") <+> ppr name
590 %*********************************************************
594 %*********************************************************
597 noIfaceErr mod_name boot_file
598 = ptext SLIT("Could not find interface file for") <+> quotes (ppr mod_name)
599 -- We used to print the search path, but we can't do that
600 -- now, because it's hidden inside the finder.
601 -- Maybe the finder should expose more functions.
603 badIfaceFile file err
604 = vcat [ptext SLIT("Bad interface file:") <+> text file,
607 hiModuleNameMismatchWarn :: Module -> Module -> Message
608 hiModuleNameMismatchWarn requested_mod read_mod =
609 hsep [ ptext SLIT("Something is amiss; requested module name")
610 , ppr (moduleName requested_mod)
611 , ptext SLIT("differs from name found in the interface file")
615 warnRedundantSourceImport mod_name
616 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
617 <+> quotes (ppr mod_name)
620 = ptext SLIT("Importing my own interface: module") <+> ppr mod