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-},
43 nameModule, isLocalName, nameIsLocalOrFrom
45 import Name ( mkNameEnv, extendNameEnv )
46 import Module ( Module,
47 moduleName, isHomeModule,
48 ModuleName, WhereFrom(..),
49 extendModuleEnv, mkVanillaModule
51 import 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 (elaborate err)
98 elaborate err = hang (ptext SLIT("failed to load interface for") <+> quotes (ppr mod) <> colon)
101 tryLoadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d (ModIface, Maybe Message)
102 -- Returns (Just err) if an error happened
103 -- It *doesn't* add an error to the monad, because sometimes it's ok to fail...
104 -- Specifically, when we read the usage information from an interface file,
105 -- we try to read the interfaces it mentions. But it's OK to fail; perhaps
106 -- the module has changed, and that interface is no longer used.
108 -- tryLoadInterface guarantees to return with iImpModInfo m --> (..., True)
109 -- (If the load fails, we plug in a vanilla placeholder)
110 tryLoadInterface doc_str mod_name from
111 = getHomeIfaceTableRn `thenRn` \ hit ->
112 getModuleRn `thenRn` \ this_mod ->
113 getIfacesRn `thenRn` \ ifaces@(Ifaces { iPIT = pit }) ->
115 -- CHECK WHETHER WE HAVE IT ALREADY
116 case lookupIfaceByModName hit pit mod_name of {
117 Just iface | case from of
118 ImportByUser -> not (mi_boot iface)
119 ImportByUserSource -> mi_boot iface
120 ImportBySystem -> True
121 -> returnRn (iface, Nothing) ; -- Already loaded
122 -- The not (mi_boot iface) test checks that the already-loaded
123 -- interface isn't a boot iface. This can conceivably happen,
124 -- if the version checking happened to load a boot interface
125 -- before we got to real imports.
129 mod_map = iImpModInfo ifaces
130 mod_info = lookupFM mod_map mod_name
133 = case (from, mod_info) of
134 (ImportByUser, _) -> False -- Not hi-boot
135 (ImportByUserSource, _) -> True -- hi-boot
136 (ImportBySystem, Just (_, is_boot)) -> is_boot
137 (ImportBySystem, Nothing) -> False
138 -- We're importing a module we know absolutely
139 -- nothing about, so we assume it's from
140 -- another package, where we aren't doing
141 -- dependency tracking. So it won't be a hi-boot file.
143 redundant_source_import
144 = case (from, mod_info) of
145 (ImportByUserSource, Just (_,False)) -> True
149 -- Issue a warning for a redundant {- SOURCE -} import
150 -- NB that we arrange to read all the ordinary imports before
151 -- any of the {- SOURCE -} imports
152 warnCheckRn (not redundant_source_import)
153 (warnRedundantSourceImport mod_name) `thenRn_`
155 -- Check that we aren't importing ourselves.
156 -- That only happens in Rename.checkOldIface,
157 -- which doesn't call tryLoadInterface
159 (not (isHomeModule this_mod) || moduleName this_mod /= mod_name)
160 (warnSelfImport this_mod) `thenRn_`
162 -- READ THE MODULE IN
163 findAndReadIface doc_str mod_name hi_boot_file `thenRn` \ read_result ->
164 case read_result of {
165 Left err -> -- Not found, so add an empty export env to the Ifaces map
166 -- so that we don't look again
168 fake_mod = mkVanillaModule mod_name
169 fake_iface = emptyModIface fake_mod
170 new_ifaces = ifaces { iPIT = extendModuleEnv pit fake_mod fake_iface }
172 setIfacesRn new_ifaces `thenRn_`
173 returnRn (fake_iface, Just err) ;
176 Right (mod, iface) ->
178 -- LOAD IT INTO Ifaces
180 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
181 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
182 -- If we do loadExport first the wrong info gets into the cache (unless we
183 -- explicitly tag each export which seems a bit of a bore)
186 -- Sanity check. If we're system-importing a module we know nothing at all
187 -- about, it should be from a different package to this one
188 WARN( not (maybeToBool mod_info) &&
189 case from of { ImportBySystem -> True; other -> False } &&
193 loadDecls mod (iDecls ifaces) (pi_decls iface) `thenRn` \ (decls_vers, new_decls) ->
194 loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ (rule_vers, new_rules) ->
195 loadInstDecls mod (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
196 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
197 loadFixDecls mod (pi_fixity iface) `thenRn` \ fix_env ->
198 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
200 version = VersionInfo { vers_module = pi_vers iface,
201 vers_exports = export_vers,
202 vers_rules = rule_vers,
203 vers_decls = decls_vers }
205 -- For an explicit user import, add to mod_map info about
206 -- the things the imported module depends on, extracted
207 -- from its usage info; and delete the module itself, which is now in the PIT
208 mod_map1 = case from of
209 ImportByUser -> addModDeps mod is_loaded (pi_usages iface) mod_map
211 mod_map2 = delFromFM mod_map1 mod_name
213 this_mod_name = moduleName this_mod
214 is_loaded m = m == this_mod_name
215 || maybeToBool (lookupIfaceByModName hit pit m)
216 -- We treat the currently-being-compiled module as 'loaded' because
217 -- even though it isn't yet in the HIT or PIT; otherwise it gets
218 -- put into iImpModInfo, and then spat out into its own interface
219 -- file as a dependency
221 -- Now add info about this module to the PIT
222 has_orphans = pi_orphan iface
223 new_pit = extendModuleEnv pit mod mod_iface
224 mod_iface = ModIface { mi_module = mod, mi_version = version,
225 mi_orphan = has_orphans, mi_boot = hi_boot_file,
227 mi_fixities = fix_env, mi_deprecs = deprec_env,
228 mi_usages = [], -- Will be filled in later
229 mi_decls = panic "No mi_decls in PIT",
230 mi_globals = mkIfaceGlobalRdrEnv avails
233 new_ifaces = ifaces { iPIT = new_pit,
237 iImpModInfo = mod_map2 }
239 setIfacesRn new_ifaces `thenRn_`
240 returnRn (mod_iface, Nothing)
243 -----------------------------------------------------
244 -- Adding module dependencies from the
245 -- import decls in the interface file
246 -----------------------------------------------------
249 -> (ModuleName -> Bool) -- True for modules that are already loaded
251 -> ImportedModuleInfo -> ImportedModuleInfo
252 -- (addModDeps M ivs deps)
253 -- We are importing module M, and M.hi contains 'import' decls given by ivs
254 addModDeps mod is_loaded new_deps mod_deps
255 = foldr add mod_deps filtered_new_deps
257 -- Don't record dependencies when importing a module from another package
258 -- Except for its descendents which contain orphans,
259 -- and in that case, forget about the boot indicator
260 filtered_new_deps :: [(ModuleName, (WhetherHasOrphans, IsBootInterface))]
262 | isHomeModule mod = [ (imp_mod, (has_orphans, is_boot))
263 | (imp_mod, has_orphans, is_boot, _) <- new_deps,
264 not (is_loaded imp_mod)
266 | otherwise = [ (imp_mod, (True, False))
267 | (imp_mod, has_orphans, _, _) <- new_deps,
268 not (is_loaded imp_mod) && has_orphans
270 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
272 combine old@(old_has_orphans, old_is_boot) new@(new_has_orphans, new_is_boot)
273 | old_is_boot = new -- Record the best is_boot info
276 -----------------------------------------------------
277 -- Loading the export list
278 -----------------------------------------------------
280 loadExports :: (Version, [ExportItem]) -> RnM d (Version, [(ModuleName,Avails)])
281 loadExports (vers, items)
282 = mapRn loadExport items `thenRn` \ avails_s ->
283 returnRn (vers, avails_s)
286 loadExport :: ExportItem -> RnM d (ModuleName, Avails)
287 loadExport (mod, entities)
288 = mapRn (load_entity mod) entities `thenRn` \ avails ->
289 returnRn (mod, avails)
291 load_entity mod (Avail occ)
292 = newGlobalName mod occ `thenRn` \ name ->
293 returnRn (Avail name)
294 load_entity mod (AvailTC occ occs)
295 = newGlobalName mod occ `thenRn` \ name ->
296 mapRn (newGlobalName mod) occs `thenRn` \ names ->
297 returnRn (AvailTC name names)
300 -----------------------------------------------------
301 -- Loading type/class/value decls
302 -----------------------------------------------------
306 -> [(Version, RdrNameTyClDecl)]
307 -> RnM d (NameEnv Version, DeclsMap)
308 loadDecls mod (decls_map, n_slurped) decls
309 = foldlRn (loadDecl mod) (emptyNameEnv, decls_map) decls `thenRn` \ (vers, decls_map') ->
310 returnRn (vers, (decls_map', n_slurped))
312 loadDecl mod (version_map, decls_map) (version, decl)
313 = getTyClDeclBinders mod decl `thenRn` \ (avail, sys_names) ->
315 full_avail = case avail of
317 AvailTC n ns -> AvailTC n (sys_names ++ ns)
318 main_name = availName full_avail
319 new_decls_map = extendNameEnvList decls_map stuff
320 stuff = [ (name, (full_avail, name==main_name, (mod, decl)))
321 | name <- availNames full_avail]
323 new_version_map = extendNameEnv version_map main_name version
325 returnRn (new_version_map, new_decls_map)
327 -----------------------------------------------------
328 -- Loading fixity decls
329 -----------------------------------------------------
331 loadFixDecls mod decls
332 = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
333 returnRn (mkNameEnv to_add)
335 mod_name = moduleName mod
337 loadFixDecl mod_name sig@(FixitySig rdr_name fixity loc)
338 = newGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
339 returnRn (name, fixity)
342 -----------------------------------------------------
343 -- Loading instance decls
344 -----------------------------------------------------
346 loadInstDecls :: Module
350 loadInstDecls mod (insts, n_slurped) decls
352 foldlRn (loadInstDecl mod) insts decls `thenRn` \ insts' ->
353 returnRn (insts', n_slurped)
356 loadInstDecl mod insts decl@(InstDecl inst_ty _ _ _ _)
357 = -- Find out what type constructors and classes are "gates" for the
358 -- instance declaration. If all these "gates" are slurped in then
359 -- we should slurp the instance decl too.
361 -- We *don't* want to count names in the context part as gates, though.
363 -- instance Foo a => Baz (T a) where ...
365 -- Here the gates are Baz and T, but *not* Foo.
367 munged_inst_ty = removeContext inst_ty
368 free_names = extractHsTyRdrNames munged_inst_ty
370 mapRn lookupIfaceName free_names `thenRn` \ gate_names ->
371 returnRn ((gate_names, (mod, decl)) `consBag` insts)
374 -- In interface files, the instance decls now look like
375 -- forall a. Foo a -> Baz (T a)
376 -- so we have to strip off function argument types as well
377 -- as the bit before the '=>' (which is always empty in interface files)
378 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
379 removeContext ty = removeFuns ty
381 removeFuns (HsFunTy _ ty) = removeFuns ty
385 -----------------------------------------------------
387 -----------------------------------------------------
389 loadRules :: Module -> IfaceRules
390 -> (Version, [RdrNameRuleDecl])
391 -> RnM d (Version, IfaceRules)
392 loadRules mod (rule_bag, n_slurped) (version, rules)
393 | null rules || opt_IgnoreIfacePragmas
394 = returnRn (version, (rule_bag, n_slurped))
397 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
398 returnRn (version, (rule_bag `unionBags` listToBag new_rules, n_slurped))
400 loadRule :: Module -> RdrNameRuleDecl -> RnM d (GatedDecl RdrNameRuleDecl)
401 -- "Gate" the rule simply by whether the rule variable is
402 -- needed. We can refine this later.
403 loadRule mod decl@(IfaceRule _ _ var _ _ src_loc)
404 = lookupIfaceName var `thenRn` \ var_name ->
405 returnRn ([var_name], (mod, decl))
408 -----------------------------------------------------
409 -- Loading Deprecations
410 -----------------------------------------------------
412 loadDeprecs :: Module -> IfaceDeprecs -> RnM d Deprecations
413 loadDeprecs m Nothing = returnRn NoDeprecs
414 loadDeprecs m (Just (Left txt)) = returnRn (DeprecAll txt)
415 loadDeprecs m (Just (Right prs)) = setModuleRn m $
416 foldlRn loadDeprec emptyNameEnv prs `thenRn` \ env ->
417 returnRn (DeprecSome env)
418 loadDeprec deprec_env (n, txt)
419 = lookupIfaceName n `thenRn` \ name ->
420 traceRn (text "Loaded deprecation(s) for" <+> ppr name <> colon <+> ppr txt) `thenRn_`
421 returnRn (extendNameEnv deprec_env name (name,txt))
425 %*********************************************************
427 \subsection{Getting binders out of a declaration}
429 %*********************************************************
431 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
432 It's used for both source code (from @availsFromDecl@) and interface files
435 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
436 are handled by the sourc-code specific stuff in @RnNames@.
438 *** See "THE NAMING STORY" in HsDecls ****
445 -> RnM d (AvailInfo, [Name]) -- The [Name] are the system names
448 getTyClDeclBinders mod (IfaceSig {tcdName = var, tcdLoc = src_loc})
449 = newTopBinder mod var src_loc `thenRn` \ var_name ->
450 returnRn (Avail var_name, [])
452 getTyClDeclBinders mod tycl_decl
453 = new_top_bndrs mod (tyClDeclNames tycl_decl) `thenRn` \ names@(main_name:_) ->
454 new_top_bndrs mod (tyClDeclSysNames tycl_decl) `thenRn` \ sys_names ->
455 returnRn (AvailTC main_name names, sys_names)
458 new_top_bndrs mod names_w_locs
459 = sequenceRn [newTopBinder mod name loc | (name,loc) <- names_w_locs]
463 %*********************************************************
465 \subsection{Reading an interface file}
467 %*********************************************************
470 findAndReadIface :: SDoc -> ModuleName
471 -> IsBootInterface -- True <=> Look for a .hi-boot file
472 -- False <=> Look for .hi file
473 -> RnM d (Either Message (Module, ParsedIface))
474 -- Nothing <=> file not found, or unreadable, or illegible
475 -- Just x <=> successfully found and parsed
477 findAndReadIface doc_str mod_name hi_boot_file
478 = traceRn trace_msg `thenRn_`
480 ioToRnM (findModule mod_name) `thenRn` \ maybe_found ->
483 Right (Just (wanted_mod,locn))
484 -> mkHiPath hi_boot_file locn `thenRn` \ file ->
485 readIface file `thenRn` \ read_result ->
487 Left bad -> returnRn (Left bad)
489 -> let read_mod = pi_mod iface
490 in warnCheckRn (wanted_mod == read_mod)
491 (hiModuleNameMismatchWarn wanted_mod
493 returnRn (Right (wanted_mod, iface))
495 other -> traceRn (ptext SLIT("...not found")) `thenRn_`
496 returnRn (Left (noIfaceErr mod_name hi_boot_file))
499 trace_msg = sep [hsep [ptext SLIT("Reading"),
500 if hi_boot_file then ptext SLIT("[boot]") else empty,
501 ptext SLIT("interface for"),
502 ppr mod_name <> semi],
503 nest 4 (ptext SLIT("reason:") <+> doc_str)]
505 mkHiPath hi_boot_file locn
507 ioToRnM_no_fail (doesFileExist hi_boot_ver_path) `thenRn` \ b ->
508 if b then returnRn hi_boot_ver_path
509 else returnRn hi_boot_path
510 | otherwise = returnRn hi_path
511 where (Just hi_path) = ml_hi_file locn
512 (hi_base, hi_suf) = splitFilename hi_path
513 hi_boot_path = hi_base ++ ".hi-boot"
514 hi_boot_ver_path = hi_base ++ ".hi-boot-" ++ cHscIfaceFileVersion
517 @readIface@ tries just the one file.
520 readIface :: String -> RnM d (Either Message ParsedIface)
521 -- Nothing <=> file not found, or unreadable, or illegible
522 -- Just x <=> successfully found and parsed
524 = --ioToRnM (putStrLn ("reading iface " ++ file_path)) `thenRn_`
525 traceRn (ptext SLIT("readIFace") <+> text file_path) `thenRn_`
527 ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
528 case read_result of {
529 Left io_error -> bale_out (text (show io_error)) ;
532 case parseIface contents init_parser_state of
533 POk _ iface -> returnRn (Right iface)
534 PFailed err -> bale_out err
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