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 #include "HsVersions.h"
17 import DriverState ( v_GhcMode, isCompManagerMode )
18 import DriverUtil ( splitFilename )
19 import CmdLineOpts ( opt_IgnoreIfacePragmas )
20 import Parser ( parseIface )
21 import HscTypes ( ModuleLocation(..),
22 ModIface(..), emptyModIface,
23 VersionInfo(..), ImportedModuleInfo,
24 lookupIfaceByModName, RdrExportItem,
25 ImportVersion, WhetherHasOrphans, IsBootInterface,
26 DeclsMap, GatedDecl, IfaceInsts, IfaceRules,
27 AvailInfo, GenAvailInfo(..), Avails, Deprecations(..)
29 import HsSyn ( TyClDecl(..), InstDecl(..), RuleDecl(..),
30 tyClDeclNames, tyClDeclSysNames, hsTyVarNames,
33 import RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl )
34 import RnHsSyn ( extractHsTyNames_s )
35 import BasicTypes ( Version )
36 import RnTypes ( rnHsType )
40 import PrelNames ( gHC_PRIM_Name, gHC_PRIM )
41 import Name ( Name {-instance NamedThing-},
42 nameModule, isInternalName, nameIsLocalOrFrom
47 import RdrName ( rdrNameOcc )
48 import SrcLoc ( mkSrcLoc )
49 import Maybes ( maybeToBool )
50 import StringBuffer ( hGetStringBuffer )
51 import FastString ( mkFastString )
52 import ErrUtils ( Message )
53 import Finder ( findModule, findPackageModule )
56 import ListSetOps ( minusList )
59 import BinIface ( {- just instances -} )
60 import qualified Binary
66 import Dynamic ( fromDynamic )
68 import List ( isSuffixOf )
72 %*********************************************************
74 \subsection{Loading a new interface file}
76 %*********************************************************
79 loadHomeInterface :: SDoc -> Name -> RnM d ModIface
80 loadHomeInterface doc_str name
81 = ASSERT2( not (isInternalName name), ppr name <+> parens doc_str )
82 loadInterface doc_str (moduleName (nameModule name)) ImportBySystem
84 loadOrphanModules :: [ModuleName] -> RnM d ()
85 loadOrphanModules mods
86 | null mods = returnRn ()
87 | otherwise = traceRn (text "Loading orphan modules:" <+>
88 fsep (map ppr mods)) `thenRn_`
89 mapRn_ load mods `thenRn_`
92 load mod = loadInterface (mk_doc mod) mod ImportBySystem
93 mk_doc mod = ppr mod <+> ptext SLIT("is a orphan-instance module")
95 loadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d ModIface
96 loadInterface doc mod from
97 = tryLoadInterface doc mod from `thenRn` \ (ifaces, maybe_err) ->
99 Nothing -> returnRn ifaces
100 Just err -> failWithRn ifaces (elaborate err)
102 elaborate err = hang (ptext SLIT("failed to load interface for") <+> quotes (ppr mod) <> colon)
105 tryLoadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d (ModIface, Maybe Message)
106 -- Returns (Just err) if an error happened
107 -- It *doesn't* add an error to the monad, because sometimes it's ok to fail...
108 -- Specifically, when we read the usage information from an interface file,
109 -- we try to read the interfaces it mentions. But it's OK to fail; perhaps
110 -- the module has changed, and that interface is no longer used.
112 -- tryLoadInterface guarantees to return with iImpModInfo m --> (..., True)
113 -- (If the load fails, we plug in a vanilla placeholder)
114 tryLoadInterface doc_str mod_name from
115 = getHomeIfaceTableRn `thenRn` \ hit ->
116 getModuleRn `thenRn` \ this_mod ->
117 getIfacesRn `thenRn` \ ifaces@(Ifaces { iPIT = pit }) ->
119 -- CHECK WHETHER WE HAVE IT ALREADY
120 case lookupIfaceByModName hit pit mod_name of {
121 Just iface | case from of
122 ImportByUser -> not (mi_boot iface)
123 ImportByUserSource -> mi_boot iface
124 ImportBySystem -> True
125 -> returnRn (iface, Nothing) ; -- Already loaded
126 -- The not (mi_boot iface) test checks that the already-loaded
127 -- interface isn't a boot iface. This can conceivably happen,
128 -- if the version checking happened to load a boot interface
129 -- before we got to real imports.
133 mod_map = iImpModInfo ifaces
134 mod_info = lookupFM mod_map mod_name
137 = case (from, mod_info) of
138 (ImportByUser, _) -> False -- Not hi-boot
139 (ImportByUserSource, _) -> True -- hi-boot
140 (ImportBySystem, Just (_, is_boot)) -> is_boot
141 (ImportBySystem, Nothing) -> False
142 -- We're importing a module we know absolutely
143 -- nothing about, so we assume it's from
144 -- another package, where we aren't doing
145 -- dependency tracking. So it won't be a hi-boot file.
147 redundant_source_import
148 = case (from, mod_info) of
149 (ImportByUserSource, Just (_,False)) -> True
153 -- Issue a warning for a redundant {- SOURCE -} import
154 -- NB that we arrange to read all the ordinary imports before
155 -- any of the {- SOURCE -} imports
156 warnCheckRn (not redundant_source_import)
157 (warnRedundantSourceImport mod_name) `thenRn_`
159 -- Check that we aren't importing ourselves.
160 -- That only happens in Rename.checkOldIface,
161 -- which doesn't call tryLoadInterface
163 (not (isHomeModule this_mod) || moduleName this_mod /= mod_name)
164 (warnSelfImport this_mod) `thenRn_`
166 -- READ THE MODULE IN
167 findAndReadIface doc_str mod_name hi_boot_file
168 `thenRn` \ read_result ->
169 case read_result of {
170 Left err -> -- Not found, so add an empty export env to the Ifaces map
171 -- so that we don't look again
173 fake_mod = mkVanillaModule mod_name
174 fake_iface = emptyModIface fake_mod
175 new_ifaces = ifaces { iPIT = extendModuleEnv pit fake_mod fake_iface }
177 setIfacesRn new_ifaces `thenRn_`
178 returnRn (fake_iface, Just err) ;
181 Right (mod, iface) ->
183 -- LOAD IT INTO Ifaces
185 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
186 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
187 -- If we do loadExport first the wrong info gets into the cache (unless we
188 -- explicitly tag each export which seems a bit of a bore)
191 -- Sanity check. If we're system-importing a module we know nothing at all
192 -- about, it should be from a different package to this one
193 WARN( not (maybeToBool mod_info) &&
194 case from of { ImportBySystem -> True; other -> False } &&
198 loadDecls mod (iDecls ifaces) (pi_decls iface) `thenRn` \ (decls_vers, new_decls) ->
199 loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ (rule_vers, new_rules) ->
200 loadInstDecls mod (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
201 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
202 loadFixDecls mod (pi_fixity iface) `thenRn` \ fix_env ->
203 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
205 version = VersionInfo { vers_module = pi_vers iface,
206 vers_exports = export_vers,
207 vers_rules = rule_vers,
208 vers_decls = decls_vers }
210 -- For an explicit user import, add to mod_map info about
211 -- the things the imported module depends on, extracted
212 -- from its usage info; and delete the module itself, which is now in the PIT
213 mod_map1 = case from of
214 ImportByUser -> addModDeps mod is_loaded (pi_usages iface) mod_map
216 mod_map2 = delFromFM mod_map1 mod_name
218 this_mod_name = moduleName this_mod
219 is_loaded m = m == this_mod_name
220 || maybeToBool (lookupIfaceByModName hit pit m)
221 -- We treat the currently-being-compiled module as 'loaded' because
222 -- even though it isn't yet in the HIT or PIT; otherwise it gets
223 -- put into iImpModInfo, and then spat out into its own interface
224 -- file as a dependency
226 -- Now add info about this module to the PIT
227 has_orphans = pi_orphan iface
228 new_pit = extendModuleEnv pit mod mod_iface
229 mod_iface = ModIface { mi_module = mod, mi_package = pi_pkg iface,
230 mi_version = version,
231 mi_orphan = has_orphans, mi_boot = hi_boot_file,
233 mi_fixities = fix_env, mi_deprecs = deprec_env,
234 mi_usages = [], -- Will be filled in later
235 mi_decls = panic "No mi_decls in PIT",
239 new_ifaces = ifaces { iPIT = new_pit,
243 iImpModInfo = mod_map2 }
245 setIfacesRn new_ifaces `thenRn_`
246 returnRn (mod_iface, Nothing)
249 -----------------------------------------------------
250 -- Adding module dependencies from the
251 -- import decls in the interface file
252 -----------------------------------------------------
255 -> (ModuleName -> Bool) -- True for modules that are already loaded
257 -> ImportedModuleInfo -> ImportedModuleInfo
258 -- (addModDeps M ivs deps)
259 -- We are importing module M, and M.hi contains 'import' decls given by ivs
260 addModDeps mod is_loaded new_deps mod_deps
261 = foldr add mod_deps filtered_new_deps
263 -- Don't record dependencies when importing a module from another package
264 -- Except for its descendents which contain orphans,
265 -- and in that case, forget about the boot indicator
266 filtered_new_deps :: [(ModuleName, (WhetherHasOrphans, IsBootInterface))]
268 | isHomeModule mod = [ (imp_mod, (has_orphans, is_boot))
269 | (imp_mod, has_orphans, is_boot, _) <- new_deps,
270 not (is_loaded imp_mod)
272 | otherwise = [ (imp_mod, (True, False))
273 | (imp_mod, has_orphans, _, _) <- new_deps,
274 not (is_loaded imp_mod) && has_orphans
276 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
278 combine old@(old_has_orphans, old_is_boot) new@(new_has_orphans, new_is_boot)
279 | old_is_boot = new -- Record the best is_boot info
282 -----------------------------------------------------
283 -- Loading the export list
284 -----------------------------------------------------
286 loadExports :: (Version, [RdrExportItem]) -> RnM d (Version, [(ModuleName,Avails)])
287 loadExports (vers, items)
288 = mapRn loadExport items `thenRn` \ avails_s ->
289 returnRn (vers, avails_s)
292 loadExport :: RdrExportItem -> RnM d (ModuleName, Avails)
293 loadExport (mod, entities)
294 = mapRn (load_entity mod) entities `thenRn` \ avails ->
295 returnRn (mod, avails)
297 load_entity mod (Avail occ)
298 = newGlobalName mod occ `thenRn` \ name ->
299 returnRn (Avail name)
300 load_entity mod (AvailTC occ occs)
301 = newGlobalName mod occ `thenRn` \ name ->
302 mapRn (newGlobalName mod) occs `thenRn` \ names ->
303 returnRn (AvailTC name names)
306 -----------------------------------------------------
307 -- Loading type/class/value decls
308 -----------------------------------------------------
312 -> [(Version, RdrNameTyClDecl)]
313 -> RnM d (NameEnv Version, DeclsMap)
314 loadDecls mod (decls_map, n_slurped) decls
315 = foldlRn (loadDecl mod) (emptyNameEnv, decls_map) decls `thenRn` \ (vers, decls_map') ->
316 returnRn (vers, (decls_map', n_slurped))
318 loadDecl mod (version_map, decls_map) (version, decl)
319 = getTyClDeclBinders mod decl `thenRn` \ (avail, sys_names) ->
321 full_avail = case avail of
323 AvailTC n ns -> AvailTC n (sys_names ++ ns)
324 main_name = availName full_avail
325 new_decls_map = extendNameEnvList decls_map stuff
326 stuff = [ (name, (full_avail, name==main_name, (mod, decl)))
327 | name <- availNames full_avail]
329 new_version_map = extendNameEnv version_map main_name version
331 traceRn (text "Loading" <+> ppr full_avail) `thenRn_`
332 returnRn (new_version_map, new_decls_map)
334 -----------------------------------------------------
335 -- Loading fixity decls
336 -----------------------------------------------------
338 loadFixDecls mod decls
339 = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
340 returnRn (mkNameEnv to_add)
342 mod_name = moduleName mod
344 loadFixDecl mod_name (rdr_name, fixity)
345 = newGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
346 returnRn (name, fixity)
349 -----------------------------------------------------
350 -- Loading instance decls
351 -----------------------------------------------------
353 loadInstDecls :: Module
357 loadInstDecls mod (insts, n_slurped) decls
359 foldlRn (loadInstDecl mod) insts decls `thenRn` \ insts' ->
360 returnRn (insts', n_slurped)
363 loadInstDecl mod insts decl@(InstDecl inst_ty _ _ _ _)
364 = -- Find out what type constructors and classes are "gates" for the
365 -- instance declaration. If all these "gates" are slurped in then
366 -- we should slurp the instance decl too.
368 -- We *don't* want to count names in the context part as gates, though.
370 -- instance Foo a => Baz (T a) where ...
372 -- Here the gates are Baz and T, but *not* Foo.
374 -- HOWEVER: functional dependencies make things more complicated
375 -- class C a b | a->b where ...
376 -- instance C Foo Baz where ...
377 -- Here, the gates are really only C and Foo, *not* Baz.
378 -- That is, if C and Foo are visible, even if Baz isn't, we must
381 -- Rather than take fundeps into account "properly", we just slurp
382 -- if C is visible and *any one* of the Names in the types
383 -- This is a slightly brutal approximation, but most instance decls
384 -- are regular H98 ones and it's perfect for them.
386 -- NOTICE that we rename the type before extracting its free
387 -- variables. The free-variable finder for a renamed HsType
388 -- does the Right Thing for built-in syntax like [] and (,).
390 rnHsType (text "In an interface instance decl") inst_ty
391 ) `thenRn` \ inst_ty' ->
393 (tvs,(cls,tys)) = getHsInstHead inst_ty'
394 free_tcs = nameSetToList (extractHsTyNames_s tys) `minusList` hsTyVarNames tvs
396 gate_fn vis_fn = vis_fn cls && (null free_tcs || any vis_fn free_tcs)
397 -- Here is the implementation of HOWEVER above
398 -- (Note that we do let the inst decl in if it mentions
399 -- no tycons at all. Hence the null free_ty_names.)
401 returnRn ((gate_fn, (mod, decl)) `consBag` insts)
405 -----------------------------------------------------
407 -----------------------------------------------------
409 loadRules :: Module -> IfaceRules
410 -> (Version, [RdrNameRuleDecl])
411 -> RnM d (Version, IfaceRules)
412 loadRules mod (rule_bag, n_slurped) (version, rules)
413 | null rules || opt_IgnoreIfacePragmas
414 = returnRn (version, (rule_bag, n_slurped))
417 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
418 returnRn (version, (rule_bag `unionBags` listToBag new_rules, n_slurped))
420 loadRule :: Module -> RdrNameRuleDecl -> RnM d (GatedDecl RdrNameRuleDecl)
421 -- "Gate" the rule simply by whether the rule variable is
422 -- needed. We can refine this later.
423 loadRule mod decl@(IfaceRule _ _ _ var _ _ src_loc)
424 = lookupIfaceName var `thenRn` \ var_name ->
425 returnRn (\vis_fn -> vis_fn var_name, (mod, decl))
428 -----------------------------------------------------
429 -- Loading Deprecations
430 -----------------------------------------------------
432 loadDeprecs :: Module -> IfaceDeprecs -> RnM d Deprecations
433 loadDeprecs m Nothing = returnRn NoDeprecs
434 loadDeprecs m (Just (Left txt)) = returnRn (DeprecAll txt)
435 loadDeprecs m (Just (Right prs)) = setModuleRn m $
436 foldlRn loadDeprec emptyNameEnv prs `thenRn` \ env ->
437 returnRn (DeprecSome env)
438 loadDeprec deprec_env (n, txt)
439 = lookupIfaceName n `thenRn` \ name ->
440 traceRn (text "Loaded deprecation(s) for" <+> ppr name <> colon <+> ppr txt) `thenRn_`
441 returnRn (extendNameEnv deprec_env name (name,txt))
445 %*********************************************************
447 \subsection{Getting binders out of a declaration}
449 %*********************************************************
451 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
452 It's used for both source code (from @availsFromDecl@) and interface files
455 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
456 are handled by the sourc-code specific stuff in @RnNames@.
458 *** See "THE NAMING STORY" in HsDecls ****
465 -> RnM d (AvailInfo, [Name]) -- The [Name] are the system names
468 getTyClDeclBinders mod (IfaceSig {tcdName = var, tcdLoc = src_loc})
469 = newTopBinder mod var src_loc `thenRn` \ var_name ->
470 returnRn (Avail var_name, [])
472 getTyClDeclBinders mod (CoreDecl {tcdName = var, tcdLoc = src_loc})
473 = newTopBinder mod var src_loc `thenRn` \ var_name ->
474 returnRn (Avail var_name, [])
476 getTyClDeclBinders mod tycl_decl
477 = new_top_bndrs mod (tyClDeclNames tycl_decl) `thenRn` \ names@(main_name:_) ->
478 new_top_bndrs mod (tyClDeclSysNames tycl_decl) `thenRn` \ sys_names ->
479 returnRn (AvailTC main_name names, sys_names)
482 new_top_bndrs mod names_w_locs
483 = sequenceRn [newTopBinder mod name loc | (name,loc) <- names_w_locs]
487 %*********************************************************
489 \subsection{Reading an interface file}
491 %*********************************************************
494 findAndReadIface :: SDoc -> ModuleName
495 -> IsBootInterface -- True <=> Look for a .hi-boot file
496 -- False <=> Look for .hi file
497 -> RnM d (Either Message (Module, ParsedIface))
498 -- Nothing <=> file not found, or unreadable, or illegible
499 -- Just x <=> successfully found and parsed
501 findAndReadIface doc_str mod_name hi_boot_file
502 = traceRn trace_msg `thenRn_`
504 -- Check for GHC.Prim, and return its static interface
505 if mod_name == gHC_PRIM_Name
506 then returnRn (Right (gHC_PRIM, ghcPrimIface))
509 -- In interactive or --make mode, we are *not allowed* to demand-load
510 -- a home package .hi file. So don't even look for them.
511 -- This helps in the case where you are sitting in eg. ghc/lib/std
512 -- and start up GHCi - it won't complain that all the modules it tries
513 -- to load are found in the home location.
514 ioToRnM_no_fail (readIORef v_GhcMode) `thenRn` \ mode ->
515 let home_allowed = hi_boot_file || not (isCompManagerMode mode)
518 ioToRnM (if home_allowed
519 then findModule mod_name
520 else findPackageModule mod_name) `thenRn` \ maybe_found ->
524 Right (Just (wanted_mod,locn))
525 -> mkHiPath hi_boot_file locn `thenRn` \ file ->
526 readIface file `thenRn` \ read_result ->
528 Left bad -> returnRn (Left bad)
529 Right iface -> -- check that the module names agree
530 let read_mod_name = pi_mod iface
531 wanted_mod_name = moduleName wanted_mod
534 (wanted_mod_name == read_mod_name)
535 (hiModuleNameMismatchWarn wanted_mod_name read_mod_name)
537 returnRn (Right (wanted_mod, iface))
539 other -> traceRn (ptext SLIT("...not found")) `thenRn_`
540 returnRn (Left (noIfaceErr mod_name hi_boot_file))
543 trace_msg = sep [hsep [ptext SLIT("Reading"),
544 if hi_boot_file then ptext SLIT("[boot]") else empty,
545 ptext SLIT("interface for"),
546 ppr mod_name <> semi],
547 nest 4 (ptext SLIT("reason:") <+> doc_str)]
549 mkHiPath hi_boot_file locn
551 ioToRnM_no_fail (doesFileExist hi_boot_ver_path) `thenRn` \ b ->
552 if b then returnRn hi_boot_ver_path
553 else returnRn hi_boot_path
554 | otherwise = returnRn hi_path
555 where hi_path = ml_hi_file locn
556 (hi_base, _hi_suf) = splitFilename hi_path
557 hi_boot_path = hi_base ++ ".hi-boot"
558 hi_boot_ver_path = hi_base ++ ".hi-boot-" ++ cHscIfaceFileVersion
561 @readIface@ tries just the one file.
564 readIface :: String -> RnM d (Either Message ParsedIface)
565 -- Nothing <=> file not found, or unreadable, or illegible
566 -- Just x <=> successfully found and parsed
568 = --ioToRnM (putStrLn ("reading iface " ++ file_path)) `thenRn_`
569 traceRn (ptext SLIT("readIFace") <+> text file_path) `thenRn_`
571 let hi_boot_ver = "hi-boot-" ++ cHscIfaceFileVersion in
572 if ".hi-boot" `isSuffixOf` file_path
573 || hi_boot_ver `isSuffixOf` file_path then
575 ioToRnM (hGetStringBuffer file_path) `thenRn` \ read_result ->
576 case read_result of {
577 Left io_error -> bale_out (text (show io_error));
580 case parseIface contents (mkPState loc exts) of {
581 POk _ iface -> returnRn (Right iface);
582 PFailed err -> bale_out err
586 ioToRnM_no_fail (myTry (Binary.getBinFileWithDict file_path))
587 `thenRn` \ either_iface ->
590 Right iface -> returnRn (Right iface)
591 Left (DynException d) | Just e <- fromDynamic d
592 -> bale_out (text (show (e :: GhcException)))
594 Left err -> bale_out (text (show err))
597 exts = ExtFlags {glasgowExtsEF = True,
601 loc = mkSrcLoc (mkFastString file_path) 1
603 bale_out err = returnRn (Left (badIfaceFile file_path err))
605 #if __GLASGOW_HASKELL__ < 501
606 myTry = Exception.tryAllIO
608 myTry = Exception.try
612 %*********************************************************
616 %*********************************************************
619 noIfaceErr mod_name boot_file
620 = ptext SLIT("Could not find interface file for") <+> quotes (ppr mod_name)
621 -- We used to print the search path, but we can't do that
622 -- now, because it's hidden inside the finder.
623 -- Maybe the finder should expose more functions.
625 badIfaceFile file err
626 = vcat [ptext SLIT("Bad interface file:") <+> text file,
629 hiModuleNameMismatchWarn :: ModuleName -> ModuleName -> Message
630 hiModuleNameMismatchWarn requested_mod read_mod =
631 hsep [ ptext SLIT("Something is amiss; requested module name")
633 , ptext SLIT("differs from name found in the interface file")
637 warnRedundantSourceImport mod_name
638 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
639 <+> quotes (ppr mod_name)
642 = ptext SLIT("Importing my own interface: module") <+> ppr mod