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 ( DynFlag(..), 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 )
59 import Util ( unJust )
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 getIfacesRn `thenRn` \ ifaces@(Ifaces { iPIT = pit }) ->
112 -- CHECK WHETHER WE HAVE IT ALREADY
113 case lookupIfaceByModName hit pit mod_name of {
114 Just iface | case from of
115 ImportByUser -> not (mi_boot iface)
116 ImportByUserSource -> mi_boot iface
117 ImportBySystem -> True
118 -> returnRn (iface, Nothing) ; -- Already loaded
119 -- The not (mi_boot iface) test checks that the already-loaded
120 -- interface isn't a boot iface. This can conceivably happen,
121 -- if the version checking happened to load a boot interface
122 -- before we got to real imports.
126 mod_map = iImpModInfo ifaces
127 mod_info = lookupFM mod_map mod_name
130 = case (from, mod_info) of
131 (ImportByUser, _) -> False -- Not hi-boot
132 (ImportByUserSource, _) -> True -- hi-boot
133 (ImportBySystem, Just (_, is_boot)) -> is_boot
134 (ImportBySystem, Nothing) -> False
135 -- We're importing a module we know absolutely
136 -- nothing about, so we assume it's from
137 -- another package, where we aren't doing
138 -- dependency tracking. So it won't be a hi-boot file.
140 redundant_source_import
141 = case (from, mod_info) of
142 (ImportByUserSource, Just (_,False)) -> True
146 -- Issue a warning for a redundant {- SOURCE -} import
147 -- NB that we arrange to read all the ordinary imports before
148 -- any of the {- SOURCE -} imports
149 warnCheckRn (not redundant_source_import)
150 (warnRedundantSourceImport mod_name) `thenRn_`
152 -- READ THE MODULE IN
153 findAndReadIface doc_str mod_name hi_boot_file `thenRn` \ read_result ->
154 case read_result of {
155 Left err -> -- Not found, so add an empty export env to the Ifaces map
156 -- so that we don't look again
158 fake_mod = mkVanillaModule mod_name
159 fake_iface = emptyModIface fake_mod
160 new_ifaces = ifaces { iPIT = extendModuleEnv pit fake_mod fake_iface }
162 setIfacesRn new_ifaces `thenRn_`
163 returnRn (fake_iface, Just err) ;
166 Right (mod, iface) ->
168 -- LOAD IT INTO Ifaces
170 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
171 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
172 -- If we do loadExport first the wrong info gets into the cache (unless we
173 -- explicitly tag each export which seems a bit of a bore)
176 -- Sanity check. If we're system-importing a module we know nothing at all
177 -- about, it should be from a different package to this one
178 WARN( not (maybeToBool mod_info) &&
179 case from of { ImportBySystem -> True; other -> False } &&
180 isModuleInThisPackage mod,
183 loadDecls mod (iDecls ifaces) (pi_decls iface) `thenRn` \ (decls_vers, new_decls) ->
184 loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ (rule_vers, new_rules) ->
185 loadInstDecls mod (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
186 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
187 loadFixDecls mod (pi_fixity iface) `thenRn` \ fix_env ->
188 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
190 version = VersionInfo { vers_module = pi_vers iface,
191 vers_exports = export_vers,
192 vers_rules = rule_vers,
193 vers_decls = decls_vers }
195 -- For an explicit user import, add to mod_map info about
196 -- the things the imported module depends on, extracted
197 -- from its usage info; and delete the module itself, which is now in the PIT
198 mod_map1 = case from of
199 ImportByUser -> addModDeps mod is_loaded (pi_usages iface) mod_map
201 mod_map2 = delFromFM mod_map1 mod_name
202 is_loaded m = maybeToBool (lookupIfaceByModName hit pit m)
204 -- Now add info about this module to the PIT
205 has_orphans = pi_orphan iface
206 new_pit = extendModuleEnv pit mod mod_iface
207 mod_iface = ModIface { mi_module = mod, mi_version = version,
208 mi_orphan = has_orphans, mi_boot = hi_boot_file,
210 mi_fixities = fix_env, mi_deprecs = deprec_env,
211 mi_usages = [], -- Will be filled in later
212 mi_decls = panic "No mi_decls in PIT",
213 mi_globals = panic "No mi_globals in PIT"
216 new_ifaces = ifaces { iPIT = new_pit,
220 iImpModInfo = mod_map2 }
222 setIfacesRn new_ifaces `thenRn_`
223 returnRn (mod_iface, Nothing)
226 -----------------------------------------------------
227 -- Adding module dependencies from the
228 -- import decls in the interface file
229 -----------------------------------------------------
232 -> (ModuleName -> Bool) -- True for module interfaces
234 -> ImportedModuleInfo -> ImportedModuleInfo
235 -- (addModDeps M ivs deps)
236 -- We are importing module M, and M.hi contains 'import' decls given by ivs
237 addModDeps mod is_loaded new_deps mod_deps
238 = foldr add mod_deps filtered_new_deps
240 -- Don't record dependencies when importing a module from another package
241 -- Except for its descendents which contain orphans,
242 -- and in that case, forget about the boot indicator
243 filtered_new_deps :: [(ModuleName, (WhetherHasOrphans, IsBootInterface))]
245 | isModuleInThisPackage mod
246 = [ (imp_mod, (has_orphans, is_boot))
247 | (imp_mod, has_orphans, is_boot, _) <- new_deps,
248 not (is_loaded imp_mod)
250 | otherwise = [ (imp_mod, (True, False))
251 | (imp_mod, has_orphans, _, _) <- new_deps,
252 not (is_loaded imp_mod) && has_orphans
254 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
256 combine old@(old_has_orphans, old_is_boot) new@(new_has_orphans, new_is_boot)
257 | old_is_boot = new -- Record the best is_boot info
260 -----------------------------------------------------
261 -- Loading the export list
262 -----------------------------------------------------
264 loadExports :: (Version, [ExportItem]) -> RnM d (Version, [(ModuleName,Avails)])
265 loadExports (vers, items)
266 = getModuleRn `thenRn` \ this_mod ->
267 mapRn (loadExport this_mod) items `thenRn` \ avails_s ->
268 returnRn (vers, avails_s)
271 loadExport :: Module -> ExportItem -> RnM d (ModuleName, Avails)
272 loadExport this_mod (mod, entities)
273 = mapRn (load_entity mod) entities `thenRn` \ avails ->
274 returnRn (mod, avails)
276 load_entity mod (Avail occ)
277 = newGlobalName mod occ `thenRn` \ name ->
278 returnRn (Avail name)
279 load_entity mod (AvailTC occ occs)
280 = newGlobalName mod occ `thenRn` \ name ->
281 mapRn (newGlobalName mod) occs `thenRn` \ names ->
282 returnRn (AvailTC name names)
285 -----------------------------------------------------
286 -- Loading type/class/value decls
287 -----------------------------------------------------
291 -> [(Version, RdrNameTyClDecl)]
292 -> RnM d (NameEnv Version, DeclsMap)
293 loadDecls mod (decls_map, n_slurped) decls
294 = foldlRn (loadDecl mod) (emptyNameEnv, decls_map) decls `thenRn` \ (vers, decls_map') ->
295 returnRn (vers, (decls_map', n_slurped))
297 loadDecl mod (version_map, decls_map) (version, decl)
298 = getIfaceDeclBinders mod decl `thenRn` \ full_avail ->
300 main_name = availName full_avail
301 new_decls_map = extendNameEnvList decls_map stuff
302 stuff = [ (name, (full_avail, name==main_name, (mod, decl)))
303 | name <- availNames full_avail]
305 new_version_map = extendNameEnv version_map main_name version
307 returnRn (new_version_map, new_decls_map)
309 -----------------------------------------------------
310 -- Loading fixity decls
311 -----------------------------------------------------
313 loadFixDecls mod decls
314 = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
315 returnRn (mkNameEnv to_add)
317 mod_name = moduleName mod
319 loadFixDecl mod_name sig@(FixitySig rdr_name fixity loc)
320 = newGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
321 returnRn (name, fixity)
324 -----------------------------------------------------
325 -- Loading instance decls
326 -----------------------------------------------------
328 loadInstDecls :: Module
332 loadInstDecls mod (insts, n_slurped) decls
334 foldlRn (loadInstDecl mod) insts decls `thenRn` \ insts' ->
335 returnRn (insts', n_slurped)
338 loadInstDecl mod insts decl@(InstDecl inst_ty _ _ _ _)
339 = -- Find out what type constructors and classes are "gates" for the
340 -- instance declaration. If all these "gates" are slurped in then
341 -- we should slurp the instance decl too.
343 -- We *don't* want to count names in the context part as gates, though.
345 -- instance Foo a => Baz (T a) where ...
347 -- Here the gates are Baz and T, but *not* Foo.
349 munged_inst_ty = removeContext inst_ty
350 free_names = extractHsTyRdrNames munged_inst_ty
352 mapRn lookupIfaceName free_names `thenRn` \ gate_names ->
353 returnRn ((gate_names, (mod, decl)) `consBag` insts)
356 -- In interface files, the instance decls now look like
357 -- forall a. Foo a -> Baz (T a)
358 -- so we have to strip off function argument types as well
359 -- as the bit before the '=>' (which is always empty in interface files)
360 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
361 removeContext ty = removeFuns ty
363 removeFuns (HsFunTy _ ty) = removeFuns ty
367 -----------------------------------------------------
369 -----------------------------------------------------
371 loadRules :: Module -> IfaceRules
372 -> (Version, [RdrNameRuleDecl])
373 -> RnM d (Version, IfaceRules)
374 loadRules mod (rule_bag, n_slurped) (version, rules)
375 | null rules || opt_IgnoreIfacePragmas
376 = returnRn (version, (rule_bag, n_slurped))
379 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
380 returnRn (version, (rule_bag `unionBags` listToBag new_rules, n_slurped))
382 loadRule :: Module -> RdrNameRuleDecl -> RnM d (GatedDecl RdrNameRuleDecl)
383 -- "Gate" the rule simply by whether the rule variable is
384 -- needed. We can refine this later.
385 loadRule mod decl@(IfaceRule _ _ var _ _ src_loc)
386 = lookupIfaceName var `thenRn` \ var_name ->
387 returnRn ([var_name], (mod, decl))
390 -----------------------------------------------------
391 -- Loading Deprecations
392 -----------------------------------------------------
394 loadDeprecs :: Module -> IfaceDeprecs -> RnM d Deprecations
395 loadDeprecs m Nothing = returnRn NoDeprecs
396 loadDeprecs m (Just (Left txt)) = returnRn (DeprecAll txt)
397 loadDeprecs m (Just (Right prs)) = setModuleRn m $
398 foldlRn loadDeprec emptyNameEnv prs `thenRn` \ env ->
399 returnRn (DeprecSome env)
400 loadDeprec deprec_env (n, txt)
401 = lookupIfaceName n `thenRn` \ name ->
402 traceRn (text "Loaded deprecation(s) for" <+> ppr name <> colon <+> ppr txt) `thenRn_`
403 returnRn (extendNameEnv deprec_env name (name,txt))
407 %*********************************************************
409 \subsection{Getting binders out of a declaration}
411 %*********************************************************
413 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
414 It's used for both source code (from @availsFromDecl@) and interface files
417 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
418 are handled by the sourc-code specific stuff in @RnNames@.
421 getIfaceDeclBinders, getTyClDeclBinders
426 getIfaceDeclBinders mod tycl_decl
427 = getTyClDeclBinders mod tycl_decl `thenRn` \ avail ->
428 getSysTyClDeclBinders mod tycl_decl `thenRn` \ extras ->
429 returnRn (addSysAvails avail extras)
430 -- Add the sys-binders to avail. When we import the decl,
431 -- it's full_avail that will get added to the 'already-slurped' set (iSlurp)
432 -- If we miss out sys-binders, we'll read the decl multiple times!
434 getTyClDeclBinders mod (IfaceSig var ty prags src_loc)
435 = newTopBinder mod var src_loc `thenRn` \ var_name ->
436 returnRn (Avail var_name)
438 getTyClDeclBinders mod tycl_decl
439 = mapRn do_one (tyClDeclNames tycl_decl) `thenRn` \ (main_name:sub_names) ->
440 returnRn (AvailTC main_name (main_name : sub_names))
442 do_one (name,loc) = newTopBinder mod name loc
445 @getDeclSysBinders@ gets the implicit binders introduced by a decl.
446 A the moment that's just the tycon and datacon that come with a class decl.
447 They aren't returned by @getDeclBinders@ because they aren't in scope;
448 but they {\em should} be put into the @DeclsMap@ of this module.
450 Note that this excludes the default-method names of a class decl,
451 and the dict fun of an instance decl, because both of these have
452 bindings of their own elsewhere.
455 getSysTyClDeclBinders mod (ClassDecl _ cname _ _ sigs _ names src_loc)
456 = sequenceRn [newTopBinder mod n src_loc | n <- names]
458 getSysTyClDeclBinders mod (TyData _ _ _ _ cons _ _ _ _ _)
459 = sequenceRn [newTopBinder mod wkr_name src_loc | ConDecl _ wkr_name _ _ _ src_loc <- cons]
461 getSysTyClDeclBinders mod other_decl
465 %*********************************************************
467 \subsection{Reading an interface file}
469 %*********************************************************
472 findAndReadIface :: SDoc -> ModuleName
473 -> IsBootInterface -- True <=> Look for a .hi-boot file
474 -- False <=> Look for .hi file
475 -> RnM d (Either Message (Module, ParsedIface))
476 -- Nothing <=> file not found, or unreadable, or illegible
477 -- Just x <=> successfully found and parsed
479 findAndReadIface doc_str mod_name hi_boot_file
480 = traceRn trace_msg `thenRn_`
481 ioToRnM (findModule mod_name) `thenRn` \ maybe_found ->
482 doptRn Opt_D_dump_rn_trace `thenRn` \ rn_trace ->
484 Right (Just (wanted_mod,locn))
487 (unJust (ml_hi_file locn) "findAndReadIface"
488 ++ if hi_boot_file then "-boot" else "")
490 `thenRn` \ read_result ->
492 Left bad -> returnRn (Left bad)
494 -> let read_mod = pi_mod iface
495 in warnCheckRn (wanted_mod == read_mod)
496 (hiModuleNameMismatchWarn wanted_mod read_mod)
498 returnRn (Right (wanted_mod, iface))
500 other -> traceRn (ptext SLIT("...not found")) `thenRn_`
501 returnRn (Left (noIfaceErr mod_name hi_boot_file))
504 trace_msg = sep [hsep [ptext SLIT("Reading"),
505 if hi_boot_file then ptext SLIT("[boot]") else empty,
506 ptext SLIT("interface for"),
507 ppr mod_name <> semi],
508 nest 4 (ptext SLIT("reason:") <+> doc_str)]
511 @readIface@ tries just the one file.
514 readIface :: Bool -> String -> IO (Either Message ParsedIface)
515 -- Nothing <=> file not found, or unreadable, or illegible
516 -- Just x <=> successfully found and parsed
517 readIface tr file_path
518 = when tr (printErrs (ptext SLIT("readIFace") <+> text file_path))
520 ((hGetStringBuffer False file_path >>= \ contents ->
521 case parseIface contents
522 PState{ bol = 0#, atbol = 1#,
525 loc = mkSrcLoc (mkFastString file_path) 1 } of
526 POk _ (PIface iface) -> return (Right iface)
527 PFailed err -> bale_out err
528 parse_result -> bale_out empty
529 -- This last case can happen if the interface file is (say) empty
530 -- in which case the parser thinks it looks like an IdInfo or
531 -- something like that. Just an artefact of the fact that the
532 -- parser is used for several purposes at once.
535 (\ io_err -> bale_out (text (show io_err))))
537 bale_out err = return (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)