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 ( HsDecl(..), 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, isLocallyDefined,
45 mkNameEnv, extendNameEnv
47 import Module ( Module,
48 moduleName, isModuleInThisPackage,
49 ModuleName, WhereFrom(..),
50 extendModuleEnv, mkVanillaModule
52 import RdrName ( RdrName, rdrNameOcc )
54 import SrcLoc ( mkSrcLoc )
55 import Maybes ( maybeToBool, orElse )
56 import StringBuffer ( hGetStringBuffer )
57 import FastString ( mkFastString )
58 import ErrUtils ( Message )
59 import Finder ( findModule )
67 %*********************************************************
69 \subsection{Loading a new interface file}
71 %*********************************************************
74 loadHomeInterface :: SDoc -> Name -> RnM d ModIface
75 loadHomeInterface doc_str name
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 lookupTableByModName hit pit mod_name of {
111 Just iface -> returnRn (iface, Nothing) ; -- Already loaded
115 mod_map = iImpModInfo ifaces
116 mod_info = lookupFM mod_map mod_name
119 = case (from, mod_info) of
120 (ImportByUser, _) -> False -- Not hi-boot
121 (ImportByUserSource, _) -> True -- hi-boot
122 (ImportBySystem, Just (_, is_boot)) -> is_boot
123 (ImportBySystem, Nothing) -> False
124 -- We're importing a module we know absolutely
125 -- nothing about, so we assume it's from
126 -- another package, where we aren't doing
127 -- dependency tracking. So it won't be a hi-boot file.
129 redundant_source_import
130 = case (from, mod_info) of
131 (ImportByUserSource, Just (_,False)) -> True
135 -- Issue a warning for a redundant {- SOURCE -} import
136 -- NB that we arrange to read all the ordinary imports before
137 -- any of the {- SOURCE -} imports
138 warnCheckRn (not redundant_source_import)
139 (warnRedundantSourceImport mod_name) `thenRn_`
141 -- READ THE MODULE IN
142 findAndReadIface doc_str mod_name hi_boot_file `thenRn` \ read_result ->
143 case read_result of {
144 Left err -> -- Not found, so add an empty export env to the Ifaces map
145 -- so that we don't look again
147 fake_mod = mkVanillaModule mod_name
148 fake_iface = emptyModIface fake_mod
149 new_ifaces = ifaces { iPIT = extendModuleEnv pit fake_mod fake_iface }
151 setIfacesRn new_ifaces `thenRn_`
152 returnRn (fake_iface, Just err) ;
155 Right (mod, iface) ->
157 -- LOAD IT INTO Ifaces
159 -- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
160 --- names is done correctly (notably, whether this is an .hi file or .hi-boot file).
161 -- If we do loadExport first the wrong info gets into the cache (unless we
162 -- explicitly tag each export which seems a bit of a bore)
165 -- Sanity check. If we're system-importing a module we know nothing at all
166 -- about, it should be from a different package to this one
167 WARN( not (maybeToBool mod_info) &&
168 case from of { ImportBySystem -> True; other -> False } &&
169 isModuleInThisPackage mod,
172 loadDecls mod (iDecls ifaces) (pi_decls iface) `thenRn` \ (decls_vers, new_decls) ->
173 loadRules mod (iRules ifaces) (pi_rules iface) `thenRn` \ (rule_vers, new_rules) ->
174 foldlRn (loadInstDecl mod) (iInsts ifaces) (pi_insts iface) `thenRn` \ new_insts ->
175 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
176 loadFixDecls mod (pi_fixity iface) `thenRn` \ fix_env ->
177 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
179 version = VersionInfo { vers_module = pi_vers iface,
180 vers_exports = export_vers,
181 vers_rules = rule_vers,
182 vers_decls = decls_vers }
184 -- For an explicit user import, add to mod_map info about
185 -- the things the imported module depends on, extracted
186 -- from its usage info; and delete the module itself, which is now in the PIT
187 mod_map1 = case from of
188 ImportByUser -> addModDeps mod is_loaded (pi_usages iface) mod_map
190 mod_map2 = delFromFM mod_map1 mod_name
191 is_loaded m = maybeToBool (lookupTableByModName hit pit m)
193 -- Now add info about this module to the PIT
194 has_orphans = pi_orphan iface
195 new_pit = extendModuleEnv pit mod mod_iface
196 mod_iface = ModIface { mi_module = mod, mi_version = version,
197 mi_orphan = has_orphans, mi_boot = hi_boot_file,
199 mi_fixities = fix_env, mi_deprecs = deprec_env,
200 mi_usages = [], -- Will be filled in later
201 mi_decls = panic "No mi_decls in PIT",
202 mi_globals = panic "No mi_globals in PIT"
205 new_ifaces = ifaces { iPIT = new_pit,
209 iImpModInfo = mod_map2 }
211 setIfacesRn new_ifaces `thenRn_`
212 returnRn (mod_iface, Nothing)
215 -----------------------------------------------------
216 -- Adding module dependencies from the
217 -- import decls in the interface file
218 -----------------------------------------------------
221 -> (ModuleName -> Bool) -- True for module interfaces
223 -> ImportedModuleInfo -> ImportedModuleInfo
224 -- (addModDeps M ivs deps)
225 -- We are importing module M, and M.hi contains 'import' decls given by ivs
226 addModDeps mod is_loaded new_deps mod_deps
227 = foldr add mod_deps filtered_new_deps
229 -- Don't record dependencies when importing a module from another package
230 -- Except for its descendents which contain orphans,
231 -- and in that case, forget about the boot indicator
232 filtered_new_deps :: [(ModuleName, (WhetherHasOrphans, IsBootInterface))]
234 | isModuleInThisPackage mod
235 = [ (imp_mod, (has_orphans, is_boot))
236 | (imp_mod, has_orphans, is_boot, _) <- new_deps,
237 not (is_loaded imp_mod)
239 | otherwise = [ (imp_mod, (True, False))
240 | (imp_mod, has_orphans, _, _) <- new_deps,
241 not (is_loaded imp_mod) && has_orphans
243 add (imp_mod, dep) deps = addToFM_C combine deps imp_mod dep
245 combine old@(old_has_orphans, old_is_boot) new@(new_has_orphans, new_is_boot)
246 | old_is_boot = new -- Record the best is_boot info
249 -----------------------------------------------------
250 -- Loading the export list
251 -----------------------------------------------------
253 loadExports :: (Version, [ExportItem]) -> RnM d (Version, [(ModuleName,Avails)])
254 loadExports (vers, items)
255 = getModuleRn `thenRn` \ this_mod ->
256 mapRn (loadExport this_mod) items `thenRn` \ avails_s ->
257 returnRn (vers, avails_s)
260 loadExport :: Module -> ExportItem -> RnM d (ModuleName, Avails)
261 loadExport this_mod (mod, entities)
262 | mod == moduleName this_mod = returnRn (mod, [])
263 -- If the module exports anything defined in this module, just ignore it.
264 -- Reason: otherwise it looks as if there are two local definition sites
265 -- for the thing, and an error gets reported. Easiest thing is just to
266 -- filter them out up front. This situation only arises if a module
267 -- imports itself, or another module that imported it. (Necessarily,
268 -- this invoves a loop.) Consequence: if you say
273 -- module B( AType ) where
274 -- import {-# SOURCE #-} A( AType )
276 -- then you'll get a 'B does not export AType' message. A bit bogus
277 -- but it's a bogus thing to do!
280 = mapRn (load_entity mod) entities `thenRn` \ avails ->
281 returnRn (mod, avails)
283 load_entity mod (Avail occ)
284 = newGlobalName mod occ `thenRn` \ name ->
285 returnRn (Avail name)
286 load_entity mod (AvailTC occ occs)
287 = newGlobalName mod occ `thenRn` \ name ->
288 mapRn (newGlobalName mod) occs `thenRn` \ names ->
289 returnRn (AvailTC name names)
292 -----------------------------------------------------
293 -- Loading type/class/value decls
294 -----------------------------------------------------
298 -> [(Version, RdrNameTyClDecl)]
299 -> RnM d (NameEnv Version, DeclsMap)
300 loadDecls mod decls_map decls
301 = foldlRn (loadDecl mod) (emptyNameEnv, decls_map) decls
304 -> (NameEnv Version, DeclsMap)
305 -> (Version, RdrNameTyClDecl)
306 -> RnM d (NameEnv Version, DeclsMap)
307 loadDecl mod (version_map, decls_map) (version, decl)
308 = getIfaceDeclBinders mod decl `thenRn` \ full_avail ->
310 main_name = availName full_avail
311 new_decls_map = extendNameEnvList decls_map stuff
312 stuff = [ (name, (full_avail, name==main_name, (mod, decl)))
313 | name <- availNames full_avail]
315 new_version_map = extendNameEnv version_map main_name version
317 returnRn (new_version_map, new_decls_map)
319 -----------------------------------------------------
320 -- Loading fixity decls
321 -----------------------------------------------------
323 loadFixDecls mod decls
324 = mapRn (loadFixDecl mod_name) decls `thenRn` \ to_add ->
325 returnRn (mkNameEnv to_add)
327 mod_name = moduleName mod
329 loadFixDecl mod_name sig@(FixitySig rdr_name fixity loc)
330 = newGlobalName mod_name (rdrNameOcc rdr_name) `thenRn` \ name ->
331 returnRn (name, fixity)
334 -----------------------------------------------------
335 -- Loading instance decls
336 -----------------------------------------------------
338 loadInstDecl :: Module
342 loadInstDecl mod insts decl@(InstDecl inst_ty binds uprags dfun_name src_loc)
344 -- Find out what type constructors and classes are "gates" for the
345 -- instance declaration. If all these "gates" are slurped in then
346 -- we should slurp the instance decl too.
348 -- We *don't* want to count names in the context part as gates, though.
350 -- instance Foo a => Baz (T a) where ...
352 -- Here the gates are Baz and T, but *not* Foo.
354 munged_inst_ty = removeContext inst_ty
355 free_names = extractHsTyRdrNames munged_inst_ty
358 mapRn lookupOrigName free_names `thenRn` \ gate_names ->
359 returnRn ((mkNameSet gate_names, (mod, InstD decl)) `consBag` insts)
362 -- In interface files, the instance decls now look like
363 -- forall a. Foo a -> Baz (T a)
364 -- so we have to strip off function argument types as well
365 -- as the bit before the '=>' (which is always empty in interface files)
366 removeContext (HsForAllTy tvs cxt ty) = HsForAllTy tvs [] (removeFuns ty)
367 removeContext ty = removeFuns ty
369 removeFuns (HsFunTy _ ty) = removeFuns ty
373 -----------------------------------------------------
375 -----------------------------------------------------
377 loadRules :: Module -> IfaceRules
378 -> (Version, [RdrNameRuleDecl])
379 -> RnM d (Version, IfaceRules)
380 loadRules mod rule_bag (version, rules)
381 | null rules || opt_IgnoreIfacePragmas
382 = returnRn (version, rule_bag)
385 mapRn (loadRule mod) rules `thenRn` \ new_rules ->
386 returnRn (version, rule_bag `unionBags` listToBag new_rules)
388 loadRule :: Module -> RdrNameRuleDecl -> RnM d GatedDecl
389 -- "Gate" the rule simply by whether the rule variable is
390 -- needed. We can refine this later.
391 loadRule mod decl@(IfaceRule _ _ var _ _ src_loc)
392 = lookupOrigName var `thenRn` \ var_name ->
393 returnRn (unitNameSet var_name, (mod, RuleD decl))
396 -----------------------------------------------------
397 -- Loading Deprecations
398 -----------------------------------------------------
400 loadDeprecs :: Module -> IfaceDeprecs -> RnM d Deprecations
401 loadDeprecs m Nothing = returnRn NoDeprecs
402 loadDeprecs m (Just (Left txt)) = returnRn (DeprecAll txt)
403 loadDeprecs m (Just (Right prs)) = setModuleRn m $
404 foldlRn loadDeprec emptyNameEnv prs `thenRn` \ env ->
405 returnRn (DeprecSome env)
406 loadDeprec deprec_env (n, txt)
407 = lookupOrigName n `thenRn` \ name ->
408 traceRn (text "Loaded deprecation(s) for" <+> ppr name <> colon <+> ppr txt) `thenRn_`
409 returnRn (extendNameEnv deprec_env name (name,txt))
413 %*********************************************************
415 \subsection{Getting binders out of a declaration}
417 %*********************************************************
419 @getDeclBinders@ returns the names for a @RdrNameHsDecl@.
420 It's used for both source code (from @availsFromDecl@) and interface files
423 It doesn't deal with source-code specific things: @ValD@, @DefD@. They
424 are handled by the sourc-code specific stuff in @RnNames@.
427 getIfaceDeclBinders, getTyClDeclBinders
432 getIfaceDeclBinders mod tycl_decl
433 = getTyClDeclBinders mod tycl_decl `thenRn` \ avail ->
434 getSysTyClDeclBinders mod tycl_decl `thenRn` \ extras ->
435 returnRn (addSysAvails avail extras)
436 -- Add the sys-binders to avail. When we import the decl,
437 -- it's full_avail that will get added to the 'already-slurped' set (iSlurp)
438 -- If we miss out sys-binders, we'll read the decl multiple times!
440 getTyClDeclBinders mod (IfaceSig var ty prags src_loc)
441 = newTopBinder mod var src_loc `thenRn` \ var_name ->
442 returnRn (Avail var_name)
444 getTyClDeclBinders mod tycl_decl
445 = mapRn do_one (tyClDeclNames tycl_decl) `thenRn` \ (main_name:sub_names) ->
446 returnRn (AvailTC main_name (main_name : sub_names))
448 do_one (name,loc) = newTopBinder mod name loc
451 @getDeclSysBinders@ gets the implicit binders introduced by a decl.
452 A the moment that's just the tycon and datacon that come with a class decl.
453 They aren't returned by @getDeclBinders@ because they aren't in scope;
454 but they {\em should} be put into the @DeclsMap@ of this module.
456 Note that this excludes the default-method names of a class decl,
457 and the dict fun of an instance decl, because both of these have
458 bindings of their own elsewhere.
461 getSysTyClDeclBinders mod (ClassDecl _ cname _ _ sigs _ names src_loc)
462 = sequenceRn [newTopBinder mod n src_loc | n <- names]
464 getSysTyClDeclBinders mod (TyData _ _ _ _ cons _ _ _ _ _)
465 = sequenceRn [newTopBinder mod wkr_name src_loc | ConDecl _ wkr_name _ _ _ src_loc <- cons]
467 getSysTyClDeclBinders mod other_decl
473 %*********************************************************
475 \subsection{Reading an interface file}
477 %*********************************************************
480 findAndReadIface :: SDoc -> ModuleName
481 -> IsBootInterface -- True <=> Look for a .hi-boot file
482 -- False <=> Look for .hi file
483 -> RnM d (Either Message (Module, ParsedIface))
484 -- Nothing <=> file not found, or unreadable, or illegible
485 -- Just x <=> successfully found and parsed
487 findAndReadIface doc_str mod_name hi_boot_file
488 = traceRn trace_msg `thenRn_`
489 ioToRnM (findModule mod_name) `thenRn` \ maybe_found ->
492 Right (Just (wanted_mod,locn))
493 -> readIface (hi_file locn ++ if hi_boot_file then "-boot" else "")
494 `thenRn` \ read_result ->
496 Left bad -> returnRn (Left bad)
498 -> let read_mod = pi_mod iface
499 in warnCheckRn (wanted_mod == read_mod)
500 (hiModuleNameMismatchWarn wanted_mod read_mod)
502 returnRn (Right (wanted_mod, iface))
504 other -> traceRn (ptext SLIT("...not found")) `thenRn_`
505 returnRn (Left (noIfaceErr mod_name hi_boot_file))
508 trace_msg = sep [hsep [ptext SLIT("Reading"),
509 if hi_boot_file then ptext SLIT("[boot]") else empty,
510 ptext SLIT("interface for"),
511 ppr mod_name <> semi],
512 nest 4 (ptext SLIT("reason:") <+> doc_str)]
515 @readIface@ tries just the one file.
518 readIface :: String -> RnM d (Either Message ParsedIface)
519 -- Nothing <=> file not found, or unreadable, or illegible
520 -- Just x <=> successfully found and parsed
522 = traceRn (ptext SLIT("readIFace") <+> text file_path) `thenRn_`
523 ioToRnM (hGetStringBuffer False file_path) `thenRn` \ read_result ->
526 case parseIface contents
527 PState{ bol = 0#, atbol = 1#,
530 loc = mkSrcLoc (mkFastString file_path) 1 } of
531 POk _ (PIface iface) -> returnRn (Right iface)
532 PFailed err -> bale_out err
533 parse_result -> bale_out empty
534 -- This last case can happen if the interface file is (say) empty
535 -- in which case the parser thinks it looks like an IdInfo or
536 -- something like that. Just an artefact of the fact that the
537 -- parser is used for several purposes at once.
539 Left io_err -> bale_out (text (show io_err))
541 bale_out err = returnRn (Left (badIfaceFile file_path err))
545 %*********************************************************
547 \subsection{Looking up fixities}
549 %*********************************************************
551 This has to be in RnIfaces (or RnHiFiles) because it calls loadHomeInterface
554 lookupFixityRn :: Name -> RnMS Fixity
556 | isLocallyDefined name
557 = getFixityEnv `thenRn` \ local_fix_env ->
558 returnRn (lookupLocalFixity local_fix_env name)
560 | otherwise -- Imported
561 -- For imported names, we have to get their fixities by doing a loadHomeInterface,
562 -- and consulting the Ifaces that comes back from that, because the interface
563 -- file for the Name might not have been loaded yet. Why not? Suppose you import module A,
564 -- which exports a function 'f', which is defined in module B. Then B isn't loaded
565 -- right away (after all, it's possible that nothing from B will be used).
566 -- When we come across a use of 'f', we need to know its fixity, and it's then,
567 -- and only then, that we load B.hi. That is what's happening here.
568 = getHomeIfaceTableRn `thenRn` \ hit ->
569 loadHomeInterface doc name `thenRn` \ iface ->
570 returnRn (lookupNameEnv (mi_fixities iface) name `orElse` defaultFixity)
572 doc = ptext SLIT("Checking fixity for") <+> ppr name
576 %*********************************************************
580 %*********************************************************
583 noIfaceErr mod_name boot_file
584 = ptext SLIT("Could not find interface file for") <+> quotes (ppr mod_name)
585 -- We used to print the search path, but we can't do that
586 -- now, because it's hidden inside the finder.
587 -- Maybe the finder should expose more functions.
589 badIfaceFile file err
590 = vcat [ptext SLIT("Bad interface file:") <+> text file,
593 hiModuleNameMismatchWarn :: Module -> Module -> Message
594 hiModuleNameMismatchWarn requested_mod read_mod =
595 hsep [ ptext SLIT("Something is amiss; requested module name")
596 , ppr (moduleName requested_mod)
597 , ptext SLIT("differs from name found in the interface file")
601 warnRedundantSourceImport mod_name
602 = ptext SLIT("Unnecessary {- SOURCE -} in the import of module")
603 <+> quotes (ppr mod_name)