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,
25 ImportVersion, WhetherHasOrphans, IsBootInterface,
26 DeclsMap, GatedDecl, IfaceInsts, IfaceRules,
27 AvailInfo, GenAvailInfo(..), Avails, Deprecations(..)
29 import HsSyn ( TyClDecl(..), InstDecl(..),
30 HsType(..), ConDecl(..),
31 FixitySig(..), RuleDecl(..),
34 import RdrHsSyn ( RdrNameTyClDecl, RdrNameInstDecl, RdrNameRuleDecl,
37 import BasicTypes ( Version, defaultFixity )
40 import ParseIface ( parseIface, IfaceStuff(..) )
42 import Name ( Name {-instance NamedThing-}, nameOccName,
43 nameModule, isLocalName, nameIsLocalOrFrom,
46 import Name ( mkNameEnv, extendNameEnv )
47 import Module ( Module,
48 moduleName, isModuleInThisPackage,
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 )
66 %*********************************************************
68 \subsection{Loading a new interface file}
70 %*********************************************************
73 loadHomeInterface :: SDoc -> Name -> RnM d ModIface
74 loadHomeInterface doc_str name
75 = ASSERT2( not (isLocalName name), ppr name <+> parens doc_str )
76 loadInterface doc_str (moduleName (nameModule name)) ImportBySystem
78 loadOrphanModules :: [ModuleName] -> RnM d ()
79 loadOrphanModules mods
80 | null mods = returnRn ()
81 | otherwise = traceRn (text "Loading orphan modules:" <+>
82 fsep (map ppr mods)) `thenRn_`
83 mapRn_ load mods `thenRn_`
86 load mod = loadInterface (mk_doc mod) mod ImportBySystem
87 mk_doc mod = ppr mod <+> ptext SLIT("is a orphan-instance module")
89 loadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d ModIface
90 loadInterface doc mod from
91 = tryLoadInterface doc mod from `thenRn` \ (ifaces, maybe_err) ->
93 Nothing -> returnRn ifaces
94 Just err -> failWithRn ifaces err
96 tryLoadInterface :: SDoc -> ModuleName -> WhereFrom -> RnM d (ModIface, Maybe Message)
97 -- Returns (Just err) if an error happened
98 -- It *doesn't* add an error to the monad, because sometimes it's ok to fail...
99 -- Specifically, when we read the usage information from an interface file,
100 -- we try to read the interfaces it mentions. But it's OK to fail; perhaps
101 -- the module has changed, and that interface is no longer used.
103 -- tryLoadInterface guarantees to return with iImpModInfo m --> (..., True)
104 -- (If the load fails, we plug in a vanilla placeholder)
105 tryLoadInterface doc_str mod_name from
106 = getHomeIfaceTableRn `thenRn` \ hit ->
107 getIfacesRn `thenRn` \ ifaces@(Ifaces { iPIT = pit }) ->
109 -- CHECK WHETHER WE HAVE IT ALREADY
110 case lookupIfaceByModName hit pit mod_name of {
111 Just iface | case from of
112 ImportByUser -> not (mi_boot iface)
113 ImportByUserSource -> mi_boot iface
114 ImportBySystem -> True
115 -> returnRn (iface, Nothing) ; -- Already loaded
116 -- The not (mi_boot iface) test checks that the already-loaded
117 -- interface isn't a boot iface. This can conceivably happen,
118 -- if the version checking happened to load a boot interface
119 -- before we got to real imports.
123 mod_map = iImpModInfo ifaces
124 mod_info = lookupFM mod_map mod_name
127 = case (from, mod_info) of
128 (ImportByUser, _) -> False -- Not hi-boot
129 (ImportByUserSource, _) -> True -- hi-boot
130 (ImportBySystem, Just (_, is_boot)) -> is_boot
131 (ImportBySystem, Nothing) -> False
132 -- We're importing a module we know absolutely
133 -- nothing about, so we assume it's from
134 -- another package, where we aren't doing
135 -- dependency tracking. So it won't be a hi-boot file.
137 redundant_source_import
138 = case (from, mod_info) of
139 (ImportByUserSource, Just (_,False)) -> True
143 -- Issue a warning for a redundant {- SOURCE -} import
144 -- NB that we arrange to read all the ordinary imports before
145 -- any of the {- SOURCE -} imports
146 warnCheckRn (not redundant_source_import)
147 (warnRedundantSourceImport mod_name) `thenRn_`
149 -- READ THE MODULE IN
150 findAndReadIface doc_str mod_name hi_boot_file `thenRn` \ read_result ->
151 case read_result of {
152 Left err -> -- Not found, so add an empty export env to the Ifaces map
153 -- so that we don't look again
155 fake_mod = mkVanillaModule mod_name
156 fake_iface = emptyModIface fake_mod
157 new_ifaces = ifaces { iPIT = extendModuleEnv pit fake_mod fake_iface }
159 setIfacesRn new_ifaces `thenRn_`
160 returnRn (fake_iface, Just err) ;
163 Right (mod, iface) ->
165 -- LOAD IT INTO Ifaces
167 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
168 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
169 -- If we do loadExport first the wrong info gets into the cache (unless we
170 -- explicitly tag each export which seems a bit of a bore)
173 -- Sanity check. If we're system-importing a module we know nothing at all
174 -- about, it should be from a different package to this one
175 WARN( not (maybeToBool mod_info) &&
176 case from of { ImportBySystem -> True; other -> False } &&
177 isModuleInThisPackage mod,
180 loadDecls mod (iDecls ifaces) (pi_decls iface) `thenRn` \ (decls_vers, new_decls) ->
181 loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ (rule_vers, new_rules) ->
182 loadInstDecls mod (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
183 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
184 loadFixDecls mod (pi_fixity iface) `thenRn` \ fix_env ->
185 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
187 version = VersionInfo { vers_module = pi_vers iface,
188 vers_exports = export_vers,
189 vers_rules = rule_vers,
190 vers_decls = decls_vers }
192 -- For an explicit user import, add to mod_map info about
193 -- the things the imported module depends on, extracted
194 -- from its usage info; and delete the module itself, which is now in the PIT
195 mod_map1 = case from of
196 ImportByUser -> addModDeps mod is_loaded (pi_usages iface) mod_map
198 mod_map2 = delFromFM mod_map1 mod_name
199 is_loaded m = maybeToBool (lookupIfaceByModName hit pit m)
201 -- Now add info about this module to the PIT
202 has_orphans = pi_orphan iface
203 new_pit = extendModuleEnv pit mod mod_iface
204 mod_iface = ModIface { mi_module = mod, mi_version = version,
205 mi_orphan = has_orphans, mi_boot = hi_boot_file,
207 mi_fixities = fix_env, mi_deprecs = deprec_env,
208 mi_usages = [], -- Will be filled in later
209 mi_decls = panic "No mi_decls in PIT",
210 mi_globals = panic "No mi_globals in PIT"
213 new_ifaces = ifaces { iPIT = new_pit,
217 iImpModInfo = mod_map2 }
219 setIfacesRn new_ifaces `thenRn_`
220 returnRn (mod_iface, Nothing)
223 -----------------------------------------------------
224 -- Adding module dependencies from the
225 -- import decls in the interface file
226 -----------------------------------------------------
229 -> (ModuleName -> Bool) -- True for module interfaces
231 -> ImportedModuleInfo -> ImportedModuleInfo
232 -- (addModDeps M ivs deps)
233 -- We are importing module M, and M.hi contains 'import' decls given by ivs
234 addModDeps mod is_loaded new_deps mod_deps
235 = foldr add mod_deps filtered_new_deps
237 -- Don't record dependencies when importing a module from another package
238 -- Except for its descendents which contain orphans,
239 -- and in that case, forget about the boot indicator
240 filtered_new_deps :: [(ModuleName, (WhetherHasOrphans, IsBootInterface))]
242 | isModuleInThisPackage mod
243 = [ (imp_mod, (has_orphans, is_boot))
244 | (imp_mod, has_orphans, is_boot, _) <- new_deps,
245 not (is_loaded imp_mod)
247 | otherwise = [ (imp_mod, (True, False))
248 | (imp_mod, has_orphans, _, _) <- new_deps,
249 not (is_loaded imp_mod) && has_orphans
251 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
253 combine old@(old_has_orphans, old_is_boot) new@(new_has_orphans, new_is_boot)
254 | old_is_boot = new -- Record the best is_boot info
257 -----------------------------------------------------
258 -- Loading the export list
259 -----------------------------------------------------
261 loadExports :: (Version, [ExportItem]) -> RnM d (Version, [(ModuleName,Avails)])
262 loadExports (vers, items)
263 = getModuleRn `thenRn` \ this_mod ->
264 mapRn (loadExport this_mod) items `thenRn` \ avails_s ->
265 returnRn (vers, avails_s)
268 loadExport :: Module -> ExportItem -> RnM d (ModuleName, Avails)
269 loadExport this_mod (mod, entities)
270 = mapRn (load_entity mod) entities `thenRn` \ avails ->
271 returnRn (mod, avails)
273 load_entity mod (Avail occ)
274 = newGlobalName mod occ `thenRn` \ name ->
275 returnRn (Avail name)
276 load_entity mod (AvailTC occ occs)
277 = newGlobalName mod occ `thenRn` \ name ->
278 mapRn (newGlobalName mod) occs `thenRn` \ names ->
279 returnRn (AvailTC name names)
282 -----------------------------------------------------
283 -- Loading type/class/value decls
284 -----------------------------------------------------
288 -> [(Version, RdrNameTyClDecl)]
289 -> RnM d (NameEnv Version, DeclsMap)
290 loadDecls mod (decls_map, n_slurped) decls
291 = foldlRn (loadDecl mod) (emptyNameEnv, decls_map) decls `thenRn` \ (vers, decls_map') ->
292 returnRn (vers, (decls_map', n_slurped))
294 loadDecl mod (version_map, decls_map) (version, decl)
295 = getIfaceDeclBinders mod decl `thenRn` \ full_avail ->
297 main_name = availName full_avail
298 new_decls_map = extendNameEnvList decls_map stuff
299 stuff = [ (name, (full_avail, name==main_name, (mod, decl)))
300 | name <- availNames full_avail]
302 new_version_map = extendNameEnv version_map main_name version
304 returnRn (new_version_map, new_decls_map)
306 -----------------------------------------------------
307 -- Loading fixity decls
308 -----------------------------------------------------
310 loadFixDecls mod decls
311 = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
312 returnRn (mkNameEnv to_add)
314 mod_name = moduleName mod
316 loadFixDecl mod_name sig@(FixitySig rdr_name fixity loc)
317 = newGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
318 returnRn (name, fixity)
321 -----------------------------------------------------
322 -- Loading instance decls
323 -----------------------------------------------------
325 loadInstDecls :: Module
329 loadInstDecls mod (insts, n_slurped) decls
331 foldlRn (loadInstDecl mod) insts decls `thenRn` \ insts' ->
332 returnRn (insts', n_slurped)
335 loadInstDecl mod insts decl@(InstDecl inst_ty _ _ _ _)
336 = -- Find out what type constructors and classes are "gates" for the
337 -- instance declaration. If all these "gates" are slurped in then
338 -- we should slurp the instance decl too.
340 -- We *don't* want to count names in the context part as gates, though.
342 -- instance Foo a => Baz (T a) where ...
344 -- Here the gates are Baz and T, but *not* Foo.
346 munged_inst_ty = removeContext inst_ty
347 free_names = extractHsTyRdrNames munged_inst_ty
349 mapRn lookupIfaceName free_names `thenRn` \ gate_names ->
350 returnRn ((gate_names, (mod, decl)) `consBag` insts)
353 -- In interface files, the instance decls now look like
354 -- forall a. Foo a -> Baz (T a)
355 -- so we have to strip off function argument types as well
356 -- as the bit before the '=>' (which is always empty in interface files)
357 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
358 removeContext ty = removeFuns ty
360 removeFuns (HsFunTy _ ty) = removeFuns ty
364 -----------------------------------------------------
366 -----------------------------------------------------
368 loadRules :: Module -> IfaceRules
369 -> (Version, [RdrNameRuleDecl])
370 -> RnM d (Version, IfaceRules)
371 loadRules mod (rule_bag, n_slurped) (version, rules)
372 | null rules || opt_IgnoreIfacePragmas
373 = returnRn (version, (rule_bag, n_slurped))
376 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
377 returnRn (version, (rule_bag `unionBags` listToBag new_rules, n_slurped))
379 loadRule :: Module -> RdrNameRuleDecl -> RnM d (GatedDecl RdrNameRuleDecl)
380 -- "Gate" the rule simply by whether the rule variable is
381 -- needed. We can refine this later.
382 loadRule mod decl@(IfaceRule _ _ var _ _ src_loc)
383 = lookupIfaceName var `thenRn` \ var_name ->
384 returnRn ([var_name], (mod, decl))
387 -----------------------------------------------------
388 -- Loading Deprecations
389 -----------------------------------------------------
391 loadDeprecs :: Module -> IfaceDeprecs -> RnM d Deprecations
392 loadDeprecs m Nothing = returnRn NoDeprecs
393 loadDeprecs m (Just (Left txt)) = returnRn (DeprecAll txt)
394 loadDeprecs m (Just (Right prs)) = setModuleRn m $
395 foldlRn loadDeprec emptyNameEnv prs `thenRn` \ env ->
396 returnRn (DeprecSome env)
397 loadDeprec deprec_env (n, txt)
398 = lookupIfaceName n `thenRn` \ name ->
399 traceRn (text "Loaded deprecation(s) for" <+> ppr name <> colon <+> ppr txt) `thenRn_`
400 returnRn (extendNameEnv deprec_env name (name,txt))
404 %*********************************************************
406 \subsection{Getting binders out of a declaration}
408 %*********************************************************
410 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
411 It's used for both source code (from @availsFromDecl@) and interface files
414 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
415 are handled by the sourc-code specific stuff in @RnNames@.
418 getIfaceDeclBinders, getTyClDeclBinders
423 getIfaceDeclBinders mod tycl_decl
424 = getTyClDeclBinders mod tycl_decl `thenRn` \ avail ->
425 getSysTyClDeclBinders mod tycl_decl `thenRn` \ extras ->
426 returnRn (addSysAvails avail extras)
427 -- Add the sys-binders to avail. When we import the decl,
428 -- it's full_avail that will get added to the 'already-slurped' set (iSlurp)
429 -- If we miss out sys-binders, we'll read the decl multiple times!
431 getTyClDeclBinders mod (IfaceSig var ty prags src_loc)
432 = newTopBinder mod var src_loc `thenRn` \ var_name ->
433 returnRn (Avail var_name)
435 getTyClDeclBinders mod tycl_decl
436 = mapRn do_one (tyClDeclNames tycl_decl) `thenRn` \ (main_name:sub_names) ->
437 returnRn (AvailTC main_name (main_name : sub_names))
439 do_one (name,loc) = newTopBinder mod name loc
442 @getDeclSysBinders@ gets the implicit binders introduced by a decl.
443 A the moment that's just the tycon and datacon that come with a class decl.
444 They aren't returned by @getDeclBinders@ because they aren't in scope;
445 but they {\em should} be put into the @DeclsMap@ of this module.
447 Note that this excludes the default-method names of a class decl,
448 and the dict fun of an instance decl, because both of these have
449 bindings of their own elsewhere.
452 getSysTyClDeclBinders mod (ClassDecl _ cname _ _ sigs _ names src_loc)
453 = sequenceRn [newTopBinder mod n src_loc | n <- names]
455 getSysTyClDeclBinders mod (TyData _ _ _ _ cons _ _ _ _ _)
456 = sequenceRn [newTopBinder mod wkr_name src_loc | ConDecl _ wkr_name _ _ _ src_loc <- cons]
458 getSysTyClDeclBinders mod other_decl
462 %*********************************************************
464 \subsection{Reading an interface file}
466 %*********************************************************
469 findAndReadIface :: SDoc -> ModuleName
470 -> IsBootInterface -- True <=> Look for a .hi-boot file
471 -- False <=> Look for .hi file
472 -> RnM d (Either Message (Module, ParsedIface))
473 -- Nothing <=> file not found, or unreadable, or illegible
474 -- Just x <=> successfully found and parsed
476 findAndReadIface doc_str mod_name hi_boot_file
477 = traceRn trace_msg `thenRn_`
479 ioToRnM (findModule mod_name) `thenRn` \ maybe_found ->
482 Right (Just (wanted_mod,locn))
483 -> readIface (mkHiPath hi_boot_file (ml_hi_file locn)) `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 read_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 (Just path)
504 | hi_boot_file = path ++ "-boot"
508 @readIface@ tries just the one file.
511 readIface :: String -> RnM d (Either Message ParsedIface)
512 -- Nothing <=> file not found, or unreadable, or illegible
513 -- Just x <=> successfully found and parsed
515 = traceRn (ptext SLIT("readIFace") <+> text file_path) `thenRn_`
517 ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
518 case read_result of {
519 Left io_error -> bale_out (text (show io_error)) ;
522 case parseIface contents init_parser_state of
523 POk _ (PIface iface) -> returnRn (Right iface)
524 PFailed err -> bale_out err
525 parse_result -> bale_out empty
526 -- This last case can happen if the interface file is (say) empty
527 -- in which case the parser thinks it looks like an IdInfo or
528 -- something like that. Just an artefact of the fact that the
529 -- parser is used for several purposes at once.
532 init_parser_state = PState{ bol = 0#, atbol = 1#,
535 loc = mkSrcLoc (mkFastString file_path) 1 }
537 bale_out err = returnRn (Left (badIfaceFile file_path err))
541 %*********************************************************
543 \subsection{Looking up fixities}
545 %*********************************************************
547 @lookupFixityRn@ has to be in RnIfaces (or RnHiFiles) because
548 it calls @loadHomeInterface@.
550 lookupFixity is a bit strange.
552 * Nested local fixity decls are put in the local fixity env, which we
553 find with getFixtyEnv
555 * Imported fixities are found in the HIT or PIT
557 * Top-level fixity decls in this module may be for Names that are
558 either Global (constructors, class operations)
559 or Local/Exported (everything else)
560 (See notes with RnNames.getLocalDeclBinders for why we have this split.)
561 We put them all in the local fixity environment
564 lookupFixityRn :: Name -> RnMS Fixity
566 = getModuleRn `thenRn` \ this_mod ->
567 if nameIsLocalOrFrom this_mod name
568 then -- It's defined in this module
569 getFixityEnv `thenRn` \ local_fix_env ->
570 returnRn (lookupLocalFixity local_fix_env name)
572 else -- It's imported
573 -- For imported names, we have to get their fixities by doing a loadHomeInterface,
574 -- and consulting the Ifaces that comes back from that, because the interface
575 -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
576 -- which exports a function 'f', which is defined in module B. Then B isn't loaded
577 -- right away (after all, it's possible that nothing from B will be used).
578 -- When we come across a use of 'f', we need to know its fixity, and it's then,
579 -- and only then, that we load B.hi. That is what's happening here.
580 loadHomeInterface doc name `thenRn` \ iface ->
581 returnRn (lookupNameEnv (mi_fixities iface) name `orElse` defaultFixity)
583 doc = ptext SLIT("Checking fixity for") <+> ppr name
587 %*********************************************************
591 %*********************************************************
594 noIfaceErr mod_name boot_file
595 = ptext SLIT("Could not find interface file for") <+> quotes (ppr mod_name)
596 -- We used to print the search path, but we can't do that
597 -- now, because it's hidden inside the finder.
598 -- Maybe the finder should expose more functions.
600 badIfaceFile file err
601 = vcat [ptext SLIT("Bad interface file:") <+> text file,
604 hiModuleNameMismatchWarn :: Module -> Module -> Message
605 hiModuleNameMismatchWarn requested_mod read_mod =
606 hsep [ ptext SLIT("Something is amiss; requested module name")
607 , ppr (moduleName requested_mod)
608 , ptext SLIT("differs from name found in the interface file")
612 warnRedundantSourceImport mod_name
613 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
614 <+> quotes (ppr mod_name)