2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section{Dealing with interface files}
8 readIface, loadInterface, loadHomeInterface,
14 #include "HsVersions.h"
16 import DriverState ( v_GhcMode, isCompManagerMode )
17 import DriverUtil ( splitFilename, replaceFilenameSuffix )
18 import CmdLineOpts ( opt_IgnoreIfacePragmas )
19 import Parser ( parseIface )
20 import HscTypes ( ModIface(..), emptyModIface,
21 ExternalPackageState(..),
22 VersionInfo(..), Usage(..),
23 lookupIfaceByModName, RdrExportItem,
24 WhetherHasOrphans, IsBootInterface,
25 DeclsMap, GatedDecl, IfaceInsts, IfaceRules, mkIfaceDecls,
26 AvailInfo, GenAvailInfo(..), ParsedIface(..), IfaceDeprecs,
27 Avails, availNames, availName, Deprecations(..)
29 import HsSyn ( TyClDecl(..), InstDecl(..), RuleDecl(..), ConDecl(..),
30 hsTyVarNames, splitHsInstDeclTy, tyClDeclName, tyClDeclNames
32 import RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl )
33 import RnHsSyn ( RenamedInstDecl, RenamedRuleDecl, RenamedTyClDecl,
35 import BasicTypes ( Version, FixitySig(..), Fixity(..), FixityDirection(..) )
36 import RnSource ( rnIfaceRuleDecl, rnTyClDecl, rnInstDecl )
37 import RnTypes ( rnHsType )
41 import PrelNames ( gHC_PRIM_Name, gHC_PRIM )
42 import PrelInfo ( ghcPrimExports, cCallableClassDecl, cReturnableClassDecl )
43 import Name ( Name {-instance NamedThing-},
44 nameModule, isInternalName )
49 import Packages ( basePackage )
50 import Module ( Module, ModuleName, ModLocation(ml_hi_file),
51 moduleName, isHomeModule, mkPackageModule,
52 extendModuleEnv, lookupModuleEnvByName
54 import RdrName ( RdrName, mkRdrUnqual, rdrNameOcc, nameRdrName )
55 import OccName ( OccName, mkWorkerOcc, mkClassTyConOcc, mkClassDataConOcc,
56 mkSuperDictSelOcc, mkGenOcc1, mkGenOcc2 )
57 import TyCon ( DataConDetails(..) )
58 import SrcLoc ( noSrcLoc, mkSrcLoc )
59 import Maybes ( maybeToBool )
60 import StringBuffer ( hGetStringBuffer )
61 import FastString ( mkFastString )
62 import ErrUtils ( Message )
63 import Finder ( findModule, findPackageModule,
64 hiBootExt, hiBootVerExt )
67 import ListSetOps ( minusList )
70 import BinIface ( readBinIface )
74 import EXCEPTION as Exception
75 import DATA_IOREF ( readIORef )
81 %*********************************************************
83 \subsection{Loading a new interface file}
85 %*********************************************************
88 loadHomeInterface :: SDoc -> Name -> TcRn m ModIface
89 loadHomeInterface doc_str name
90 = ASSERT2( not (isInternalName name), ppr name <+> parens doc_str )
91 loadInterface doc_str (moduleName (nameModule name)) ImportBySystem
93 loadOrphanModules :: [ModuleName] -> TcRn m ()
94 loadOrphanModules mods
95 | null mods = returnM ()
96 | otherwise = traceRn (text "Loading orphan modules:" <+>
97 fsep (map ppr mods)) `thenM_`
98 mappM_ load mods `thenM_`
101 load mod = loadInterface (mk_doc mod) mod ImportBySystem
102 mk_doc mod = ppr mod <+> ptext SLIT("is a orphan-instance module")
104 loadInterface :: SDoc -> ModuleName -> WhereFrom -> TcRn m ModIface
105 -- Returns Nothing if failed
106 -- If we can't find an interface file, and we are doing ImportForUsage,
107 -- just fail in the monad, and modify anything else
108 -- Otherwise, if we can't find an interface file,
109 -- add an error message to the monad (the first time only)
110 -- and return emptyIface
111 -- The "first time only" part is done by modifying the PackageIfaceTable
112 -- to have an empty entry
114 -- The ImportForUsage case is because when we read the usage information from
115 -- an interface file, we try to read the interfaces it mentions.
116 -- But it's OK to fail; perhaps the module has changed, and that interface
117 -- is no longer used.
119 loadInterface doc_str mod_name from
120 = getHpt `thenM` \ hpt ->
121 getModule `thenM` \ this_mod ->
122 getImports `thenM` \ import_avails ->
123 getEps `thenM` \ eps@(EPS { eps_PIT = pit }) ->
125 -- CHECK WHETHER WE HAVE IT ALREADY
126 case lookupIfaceByModName hpt pit mod_name of {
127 Just iface | case from of
128 ImportByUser src_imp -> src_imp == mi_boot iface
129 ImportForUsage src_imp -> src_imp == mi_boot iface
130 ImportBySystem -> True
131 -> returnM iface ; -- Already loaded
132 -- The not (mi_boot iface) test checks that the already-loaded
133 -- interface isn't a boot iface. This can conceivably happen,
134 -- if the version checking happened to load a boot interface
135 -- before we got to real imports.
138 traceRn (vcat [text "loadInterface" <+> brackets doc_str,
139 ppr (dep_mods import_avails)]) `thenM_`
141 mod_map = dep_mods import_avails
142 mod_info = lookupModuleEnvByName mod_map mod_name
145 = case (from, mod_info) of
146 (ImportByUser is_boot, _) -> is_boot
147 (ImportForUsage is_boot, _) -> is_boot
148 (ImportBySystem, Just (_, _, is_boot)) -> is_boot
149 (ImportBySystem, Nothing) -> False
150 -- We're importing a module we know absolutely
151 -- nothing about, so we assume it's from
152 -- another package, where we aren't doing
153 -- dependency tracking. So it won't be a hi-boot file.
155 redundant_source_import
156 = case (from, mod_info) of
157 (ImportByUser True, Just (_, _, False)) -> True
161 -- Issue a warning for a redundant {- SOURCE -} import
162 -- NB that we arrange to read all the ordinary imports before
163 -- any of the {- SOURCE -} imports
164 warnIf redundant_source_import
165 (warnRedundantSourceImport mod_name) `thenM_`
167 -- Check that we aren't importing ourselves.
168 -- That only happens in Rename.checkOldIface,
169 -- which doesn't call loadInterface
171 (isHomeModule this_mod && moduleName this_mod == mod_name)
172 (warnSelfImport this_mod) `thenM_`
174 -- READ THE MODULE IN
175 findAndReadIface doc_str mod_name hi_boot_file
176 `thenM` \ read_result ->
177 case read_result of {
179 | case from of { ImportForUsage _ -> True ; other -> False }
180 -> failM -- Fail with no error messages
183 -> let -- Not found, so add an empty export env to
184 -- the EPS map so that we don't look again
185 fake_mod = mkPackageModule mod_name
186 fake_iface = emptyModIface fake_mod
187 new_eps = eps { eps_PIT = extendModuleEnv pit fake_mod fake_iface }
189 setEps new_eps `thenM_`
190 addErr (elaborate err) `thenM_`
193 elaborate err = hang (ptext SLIT("Failed to load interface for") <+>
194 quotes (ppr mod_name) <> colon) 4 err
198 Right (mod, iface) ->
202 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
203 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
204 -- If we do loadExport first the wrong info gets into the cache (unless we
205 -- explicitly tag each export which seems a bit of a bore)
208 -- Sanity check. If we're system-importing a module we know nothing at all
209 -- about, it should be from a different package to this one
210 WARN( not (maybeToBool mod_info) &&
211 case from of { ImportBySystem -> True; other -> False } &&
215 initRn (InterfaceMode mod) $
216 -- Set the module, for use when looking up occurrences
217 -- of names in interface decls and rules
218 loadDecls mod (eps_decls eps) (pi_decls iface) `thenM` \ (decls_vers, new_decls) ->
219 loadRules mod (eps_rules eps) (pi_rules iface) `thenM` \ (rule_vers, new_rules) ->
220 loadInstDecls mod (eps_insts eps) (pi_insts iface) `thenM` \ new_insts ->
221 loadExports (pi_exports iface) `thenM` \ (export_vers, avails) ->
222 loadFixDecls (pi_fixity iface) `thenM` \ fix_env ->
223 loadDeprecs (pi_deprecs iface) `thenM` \ deprec_env ->
225 version = VersionInfo { vers_module = pi_vers iface,
226 vers_exports = export_vers,
227 vers_rules = rule_vers,
228 vers_decls = decls_vers }
230 this_mod_name = moduleName this_mod
231 is_loaded m = m == this_mod_name
232 || maybeToBool (lookupIfaceByModName hpt pit m)
233 -- We treat the currently-being-compiled module as 'loaded' because
234 -- even though it isn't yet in the HIT or PIT; otherwise it gets
235 -- put into iImpModInfo, and then spat out into its own interface
236 -- file as a dependency
238 -- Now add info about this module to the PIT
239 has_orphans = pi_orphan iface
240 new_pit = extendModuleEnv pit mod mod_iface
241 mod_iface = ModIface { mi_module = mod, mi_package = pi_pkg iface,
242 mi_version = version,
243 mi_orphan = has_orphans, mi_boot = hi_boot_file,
245 mi_fixities = fix_env, mi_deprecs = deprec_env,
246 mi_deps = pi_deps iface,
247 mi_usages = panic "No mi_usages in PIT",
248 mi_decls = panic "No mi_decls in PIT",
252 new_eps = eps { eps_PIT = new_pit,
253 eps_decls = new_decls,
254 eps_insts = new_insts,
255 eps_rules = new_rules }
257 setEps new_eps `thenM_`
261 -----------------------------------------------------
262 -- Loading the export list
263 -----------------------------------------------------
265 loadExports :: (Version, [RdrExportItem]) -> TcRn m (Version, [(ModuleName,Avails)])
266 loadExports (vers, items)
267 = mappM loadExport items `thenM` \ avails_s ->
268 returnM (vers, avails_s)
271 loadExport :: RdrExportItem -> TcRn m (ModuleName, Avails)
272 loadExport (mod, entities)
273 = mappM (load_entity mod) entities `thenM` \ avails ->
274 returnM (mod, avails)
276 load_entity mod (Avail occ)
277 = newGlobalName2 mod occ `thenM` \ name ->
279 load_entity mod (AvailTC occ occs)
280 = newGlobalName2 mod occ `thenM` \ name ->
281 mappM (newGlobalName2 mod) occs `thenM` \ names ->
282 returnM (AvailTC name names)
285 -----------------------------------------------------
286 -- Loading type/class/value decls
287 -----------------------------------------------------
291 -> [(Version, RdrNameTyClDecl)]
292 -> TcRn m (NameEnv Version, DeclsMap)
293 loadDecls mod (decls_map, n_slurped) decls
294 = foldlM (loadDecl mod) (emptyNameEnv, decls_map) decls `thenM` \ (vers, decls_map') ->
295 returnM (vers, (decls_map', n_slurped))
297 loadDecl mod (version_map, decls_map) (version, decl)
298 = getTyClDeclBinders mod decl `thenM` \ avail ->
299 getSysBinders mod decl `thenM` \ sys_names ->
301 full_avail = case avail of
303 AvailTC n ns -> AvailTC n (sys_names ++ ns)
304 main_name = availName full_avail
305 new_decls_map = extendNameEnvList decls_map stuff
306 stuff = [ (name, (full_avail, name==main_name, (mod, decl)))
307 | name <- availNames full_avail]
309 new_version_map = extendNameEnv version_map main_name version
311 traceRn (text "Loading" <+> ppr full_avail) `thenM_`
312 returnM (new_version_map, new_decls_map)
317 getTyClDeclBinders :: Module -> RdrNameTyClDecl -> TcRn m AvailInfo
319 getTyClDeclBinders mod (IfaceSig {tcdName = var, tcdLoc = src_loc})
320 = newTopBinder mod var src_loc `thenM` \ var_name ->
321 returnM (Avail var_name)
323 getTyClDeclBinders mod tycl_decl
324 = mapM new (tyClDeclNames tycl_decl) `thenM` \ names@(main_name:_) ->
325 returnM (AvailTC main_name names)
327 new (nm,loc) = newTopBinder mod nm loc
329 --------------------------------
330 -- The "system names" are extra implicit names *bound* by the decl.
332 getSysBinders :: Module -> TyClDecl RdrName -> TcRn m [Name]
333 -- Similar to tyClDeclNames, but returns the "implicit"
334 -- or "system" names of the declaration. And it only works
335 -- on RdrNames, returning OccNames
337 getSysBinders mod (ClassDecl {tcdName = cname, tcdCtxt = cxt, tcdLoc = loc})
338 = sequenceM [new_sys_bndr mod n loc | n <- sys_occs]
340 -- C.f. TcClassDcl.tcClassDecl1
341 sys_occs = tc_occ : data_occ : dw_occ : sc_sel_occs
342 cls_occ = rdrNameOcc cname
343 data_occ = mkClassDataConOcc cls_occ
344 dw_occ = mkWorkerOcc data_occ
345 tc_occ = mkClassTyConOcc cls_occ
346 sc_sel_occs = [mkSuperDictSelOcc n cls_occ | n <- [1..length cxt]]
348 getSysBinders mod (TyData {tcdName = tc_name, tcdCons = DataCons cons,
349 tcdGeneric = Just want_generic, tcdLoc = loc})
350 -- The 'Just' is because this is an interface-file decl
351 -- so it will say whether to derive generic stuff for it or not
352 = sequenceM ([new_sys_bndr mod n loc | n <- gen_occs] ++
353 map con_sys_occ cons)
355 -- c.f. TcTyDecls.tcTyDecl
356 tc_occ = rdrNameOcc tc_name
357 gen_occs | want_generic = [mkGenOcc1 tc_occ, mkGenOcc2 tc_occ]
359 con_sys_occ (ConDecl name _ _ _ loc)
360 = new_sys_bndr mod (mkWorkerOcc (rdrNameOcc name)) loc
362 getSysBinders mod decl = returnM []
364 new_sys_bndr mod occ loc = newTopBinder mod (mkRdrUnqual occ) loc
367 -----------------------------------------------------
368 -- Loading fixity decls
369 -----------------------------------------------------
372 = mappM loadFixDecl decls `thenM` \ to_add ->
373 returnM (mkNameEnv to_add)
375 loadFixDecl (FixitySig rdr_name fixity loc)
376 = lookupGlobalOccRn rdr_name `thenM` \ name ->
377 returnM (name, FixitySig name fixity loc)
380 -----------------------------------------------------
381 -- Loading instance decls
382 -----------------------------------------------------
384 loadInstDecls :: Module -> IfaceInsts
387 loadInstDecls mod (insts, n_slurped) decls
388 = foldlM (loadInstDecl mod) insts decls `thenM` \ insts' ->
389 returnM (insts', n_slurped)
392 loadInstDecl mod insts decl@(InstDecl inst_ty _ _ _ _)
393 = -- Find out what type constructors and classes are "gates" for the
394 -- instance declaration. If all these "gates" are slurped in then
395 -- we should slurp the instance decl too.
397 -- We *don't* want to count names in the context part as gates, though.
399 -- instance Foo a => Baz (T a) where ...
401 -- Here the gates are Baz and T, but *not* Foo.
403 -- HOWEVER: functional dependencies make things more complicated
404 -- class C a b | a->b where ...
405 -- instance C Foo Baz where ...
406 -- Here, the gates are really only C and Foo, *not* Baz.
407 -- That is, if C and Foo are visible, even if Baz isn't, we must
410 -- Rather than take fundeps into account "properly", we just slurp
411 -- if C is visible and *any one* of the Names in the types
412 -- This is a slightly brutal approximation, but most instance decls
413 -- are regular H98 ones and it's perfect for them.
415 -- NOTICE that we rename the type before extracting its free
416 -- variables. The free-variable finder for a renamed HsType
417 -- does the Right Thing for built-in syntax like [] and (,).
418 rnHsType (text "In an interface instance decl") inst_ty `thenM` \ inst_ty' ->
420 (tvs,_,cls,tys) = splitHsInstDeclTy inst_ty'
421 free_tcs = nameSetToList (extractHsTyNames_s tys) `minusList` hsTyVarNames tvs
423 gate_fn vis_fn = vis_fn cls && (null free_tcs || any vis_fn free_tcs)
424 -- The 'vis_fn' returns True for visible names
425 -- Here is the implementation of HOWEVER above
426 -- (Note that we do let the inst decl in if it mentions
427 -- no tycons at all. Hence the null free_ty_names.)
429 traceRn ((text "Load instance for" <+> ppr inst_ty') $$ ppr free_tcs) `thenM_`
430 returnM ((gate_fn, (mod, decl)) `consBag` insts)
434 -----------------------------------------------------
436 -----------------------------------------------------
440 -> (Version, [RdrNameRuleDecl])
441 -> RnM (Version, IfaceRules)
442 loadRules mod (rule_bag, n_slurped) (version, rules)
443 | null rules || opt_IgnoreIfacePragmas
444 = returnM (version, (rule_bag, n_slurped))
446 = mappM (loadRule mod) rules `thenM` \ new_rules ->
447 returnM (version, (rule_bag `unionBags` listToBag new_rules, n_slurped))
449 loadRule :: Module -> RdrNameRuleDecl -> RnM (GatedDecl RdrNameRuleDecl)
450 -- "Gate" the rule simply by whether the rule variable is
451 -- needed. We can refine this later.
452 loadRule mod decl@(IfaceRule _ _ _ var _ _ src_loc)
453 = lookupGlobalOccRn var `thenM` \ var_name ->
454 returnM (\vis_fn -> vis_fn var_name, (mod, decl))
457 -----------------------------------------------------
458 -- Loading Deprecations
459 -----------------------------------------------------
461 loadDeprecs :: IfaceDeprecs -> RnM Deprecations
462 loadDeprecs Nothing = returnM NoDeprecs
463 loadDeprecs (Just (Left txt)) = returnM (DeprecAll txt)
464 loadDeprecs (Just (Right prs)) = foldlM loadDeprec emptyNameEnv prs `thenM` \ env ->
465 returnM (DeprecSome env)
466 loadDeprec deprec_env (n, txt)
467 = lookupGlobalOccRn n `thenM` \ name ->
468 traceRn (text "Loaded deprecation(s) for" <+> ppr name <> colon <+> ppr txt) `thenM_`
469 returnM (extendNameEnv deprec_env name (name,txt))
473 %********************************************************
475 Load the ParsedIface for the *current* module
476 into a ModIface; then it can be checked
479 %********************************************************
482 loadOldIface :: ParsedIface -> RnM ModIface
485 = loadHomeDecls (pi_decls iface) `thenM` \ (decls_vers, new_decls) ->
486 loadHomeRules (pi_rules iface) `thenM` \ (rule_vers, new_rules) ->
487 loadHomeInsts (pi_insts iface) `thenM` \ new_insts ->
488 mappM loadHomeUsage (pi_usages iface) `thenM` \ usages ->
489 loadExports (pi_exports iface) `thenM` \ (export_vers, avails) ->
490 loadFixDecls (pi_fixity iface) `thenM` \ fix_env ->
491 loadDeprecs (pi_deprecs iface) `thenM` \ deprec_env ->
493 getModeRn `thenM` \ (InterfaceMode mod) ->
494 -- Caller sets the module before the call; also needed
495 -- by the newGlobalName stuff in some of the loadHomeX calls
497 version = VersionInfo { vers_module = pi_vers iface,
498 vers_exports = export_vers,
499 vers_rules = rule_vers,
500 vers_decls = decls_vers }
502 decls = mkIfaceDecls new_decls new_rules new_insts
504 mod_iface = ModIface { mi_module = mod, mi_package = pi_pkg iface,
505 mi_version = version, mi_deps = pi_deps iface,
506 mi_exports = avails, mi_usages = usages,
507 mi_boot = False, mi_orphan = pi_orphan iface,
508 mi_fixities = fix_env, mi_deprecs = deprec_env,
517 loadHomeDecls :: [(Version, RdrNameTyClDecl)]
518 -> RnM (NameEnv Version, [RenamedTyClDecl])
519 loadHomeDecls decls = foldlM loadHomeDecl (emptyNameEnv, []) decls
521 loadHomeDecl :: (NameEnv Version, [RenamedTyClDecl])
522 -> (Version, RdrNameTyClDecl)
523 -> RnM (NameEnv Version, [RenamedTyClDecl])
524 loadHomeDecl (version_map, decls) (version, decl)
525 = rnTyClDecl decl `thenM` \ decl' ->
526 returnM (extendNameEnv version_map (tyClDeclName decl') version, decl':decls)
529 loadHomeRules :: (Version, [RdrNameRuleDecl])
530 -> RnM (Version, [RenamedRuleDecl])
531 loadHomeRules (version, rules)
532 = mappM rnIfaceRuleDecl rules `thenM` \ rules' ->
533 returnM (version, rules')
536 loadHomeInsts :: [RdrNameInstDecl]
537 -> RnM [RenamedInstDecl]
538 loadHomeInsts insts = mappM rnInstDecl insts
541 loadHomeUsage :: Usage OccName -> TcRn m (Usage Name)
543 = mappM rn_imp (usg_entities usage) `thenM` \ entities' ->
544 returnM (usage { usg_entities = entities' })
546 mod_name = usg_name usage
547 rn_imp (occ,vers) = newGlobalName2 mod_name occ `thenM` \ name ->
552 %*********************************************************
554 \subsection{Reading an interface file}
556 %*********************************************************
559 findAndReadIface :: SDoc -> ModuleName
560 -> IsBootInterface -- True <=> Look for a .hi-boot file
561 -- False <=> Look for .hi file
562 -> TcRn m (Either Message (Module, ParsedIface))
563 -- Nothing <=> file not found, or unreadable, or illegible
564 -- Just x <=> successfully found and parsed
566 -- It *doesn't* add an error to the monad, because
567 -- sometimes it's ok to fail... see notes with loadInterface
569 findAndReadIface doc_str mod_name hi_boot_file
570 = traceRn trace_msg `thenM_`
572 -- Check for GHC.Prim, and return its static interface
573 if mod_name == gHC_PRIM_Name
574 then returnM (Right (gHC_PRIM, ghcPrimIface))
577 ioToTcRn (findHiFile mod_name hi_boot_file) `thenM` \ maybe_found ->
581 traceRn (ptext SLIT("...not found")) `thenM_`
582 returnM (Left (noIfaceErr mod_name hi_boot_file))
584 Just (wanted_mod, file_path) ->
585 traceRn (ptext SLIT("readIFace") <+> text file_path) `thenM_`
587 readIface wanted_mod file_path hi_boot_file `thenM` \ read_result ->
588 -- Catch exceptions here
591 Left exn -> returnM (Left (badIfaceFile file_path
592 (text (showException exn))))
594 Right iface -> returnM (Right (wanted_mod, iface))
597 trace_msg = sep [hsep [ptext SLIT("Reading"),
598 if hi_boot_file then ptext SLIT("[boot]") else empty,
599 ptext SLIT("interface for"),
600 ppr mod_name <> semi],
601 nest 4 (ptext SLIT("reason:") <+> doc_str)]
603 findHiFile :: ModuleName -> IsBootInterface -> IO (Maybe (Module, FilePath))
604 findHiFile mod_name hi_boot_file
606 -- In interactive or --make mode, we are *not allowed* to demand-load
607 -- a home package .hi file. So don't even look for them.
608 -- This helps in the case where you are sitting in eg. ghc/lib/std
609 -- and start up GHCi - it won't complain that all the modules it tries
610 -- to load are found in the home location.
611 ghci_mode <- readIORef v_GhcMode ;
612 let { home_allowed = hi_boot_file ||
613 not (isCompManagerMode ghci_mode) } ;
614 maybe_found <- if home_allowed
615 then findModule mod_name
616 else findPackageModule mod_name ;
618 case maybe_found of {
619 Nothing -> return Nothing ;
621 Just (mod,loc) -> do {
623 -- Return the path to M.hi, M.hi-boot, or M.hi-boot-n as appropriate
624 let { hi_path = ml_hi_file loc ;
625 hi_boot_path = replaceFilenameSuffix hi_path hiBootExt ;
626 hi_boot_ver_path = replaceFilenameSuffix hi_path hiBootVerExt
629 if not hi_boot_file then
630 return (Just (mod, hi_path))
632 hi_ver_exists <- doesFileExist hi_boot_ver_path ;
633 if hi_ver_exists then return (Just (mod, hi_boot_ver_path))
634 else return (Just (mod, hi_boot_path))
638 @readIface@ tries just the one file.
641 readIface :: Module -> String -> IsBootInterface -> TcRn m (Either Exception ParsedIface)
642 -- Nothing <=> file not found, or unreadable, or illegible
643 -- Just x <=> successfully found and parsed
645 readIface mod file_path is_hi_boot_file
646 = ioToTcRn (tryMost (read_iface mod file_path is_hi_boot_file))
648 read_iface mod file_path is_hi_boot_file
649 | is_hi_boot_file -- Read ascii
650 = do { buffer <- hGetStringBuffer file_path ;
651 case parseIface buffer (mkPState loc exts) of
652 POk _ iface | wanted_mod_name == actual_mod_name
655 -> throwDyn (ProgramError (showSDoc err))
656 -- 'showSDoc' is a bit yukky
658 wanted_mod_name = moduleName mod
659 actual_mod_name = pi_mod iface
660 err = hiModuleNameMismatchWarn wanted_mod_name actual_mod_name
662 PFailed err -> throwDyn (ProgramError (showSDoc err))
665 | otherwise -- Read binary
666 = readBinIface file_path
669 exts = ExtFlags {glasgowExtsEF = True,
673 loc = mkSrcLoc (mkFastString file_path) 1
677 %*********************************************************
679 Wired-in interface for GHC.Prim
681 %*********************************************************
684 ghcPrimIface :: ParsedIface
685 ghcPrimIface = ParsedIface {
686 pi_mod = gHC_PRIM_Name,
687 pi_pkg = basePackage,
692 pi_exports = (1, [(gHC_PRIM_Name, ghcPrimExports)]),
693 pi_decls = [(1,cCallableClassDecl),
694 (1,cReturnableClassDecl)],
695 pi_fixity = [FixitySig (nameRdrName (idName seqId))
696 (Fixity 0 InfixR) noSrcLoc],
704 %*********************************************************
708 %*********************************************************
711 noIfaceErr mod_name boot_file
712 = ptext SLIT("Could not find interface file for") <+> quotes (ppr mod_name)
713 -- We used to print the search path, but we can't do that
714 -- now, because it's hidden inside the finder.
715 -- Maybe the finder should expose more functions.
717 badIfaceFile file err
718 = vcat [ptext SLIT("Bad interface file:") <+> text file,
721 hiModuleNameMismatchWarn :: ModuleName -> ModuleName -> Message
722 hiModuleNameMismatchWarn requested_mod read_mod =
723 hsep [ ptext SLIT("Something is amiss; requested module name")
725 , ptext SLIT("differs from name found in the interface file")
729 warnRedundantSourceImport mod_name
730 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
731 <+> quotes (ppr mod_name)
734 = ptext SLIT("Importing my own interface: module") <+> ppr mod