2 % (c) The GRASP Project, Glasgow University, 1992-1998
4 \section[Rename]{Renaming and dependency analysis passes}
7 module Rename ( renameModule ) where
9 #include "HsVersions.h"
12 import HsPragmas ( DataPragmas(..) )
13 import RdrHsSyn ( RdrNameHsModule, RdrNameHsDecl, RdrNameDeprecation )
14 import RnHsSyn ( RenamedHsModule, RenamedHsDecl,
15 extractHsTyNames, extractHsCtxtTyNames
18 import CmdLineOpts ( DynFlags, DynFlag(..) )
20 import RnNames ( getGlobalNames )
21 import RnSource ( rnSourceDecls, rnDecl )
22 import RnIfaces ( getImportedInstDecls, importDecl, mkImportInfo,
24 getImportedRules, getSlurped, removeContext,
25 ImportDeclResult(..), findAndReadIface
27 import RnEnv ( availName, availsToNameSet,
28 emptyAvailEnv, unitAvailEnv, availEnvElts, plusAvailEnv, sortAvails,
29 warnUnusedImports, warnUnusedLocalBinds, warnUnusedModules,
30 lookupOrigNames, unknownNameErr,
31 FreeVars, plusFVs, plusFV, unitFV, emptyFVs, isEmptyFVs, addOneFV
33 import Module ( Module, ModuleName, WhereFrom(..),
34 moduleNameUserString, moduleName, mkModuleInThisPackage,
37 import Name ( Name, isLocallyDefined, NamedThing(..), getSrcLoc,
38 nameOccName, nameUnique, nameModule,
39 isUserExportedName, toRdrName,
40 mkNameEnv, nameEnvElts, extendNameEnv
42 import OccName ( occNameFlavour, isValOcc )
44 import TyCon ( isSynTyCon, getSynTyConDefn )
46 import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon, boolTyCon )
47 import PrelNames ( mAIN_Name, pREL_MAIN_Name, pRELUDE_Name,
49 unpackCString_RDR, unpackCStringFoldr_RDR, unpackCStringUtf8_RDR,
52 import PrelInfo ( fractionalClassKeys, derivingOccurrences, wiredInThingEnv )
53 import Type ( namesOfType, funTyCon )
54 import ErrUtils ( printErrorsAndWarnings, dumpIfSet, ghcExit )
55 import BasicTypes ( Version, initialVersion )
56 import Bag ( isEmptyBag, bagToList )
57 import FiniteMap ( FiniteMap, eltsFM, fmToList, emptyFM, lookupFM,
58 addToFM_C, elemFM, addToFM
60 import UniqSupply ( UniqSupply )
61 import UniqFM ( lookupUFM )
62 import SrcLoc ( noSrcLoc )
63 import Maybes ( maybeToBool, expectJust )
65 import IO ( openFile, IOMode(..) )
66 import HscTypes ( Finder, PersistentCompilerState, HomeIfaceTable, HomeSymbolTable,
67 ModIface(..), TyThing(..),
68 GlobalRdrEnv, AvailEnv, Avails, GenAvailInfo(..), AvailInfo,
69 Provenance(..), pprNameProvenance, ImportReason(..),
72 import List ( partition, nub )
78 renameModule :: DynFlags -> Finder
79 -> HomeIfaceTable -> HomeSymbolTable
80 -> PersistentCompilerState
81 -> Module -> RdrNameHsModule
82 -> IO (PersistentCompilerState, Maybe ModIface)
83 -- The mi_decls in the ModIface include
84 -- ones imported from packages too
86 renameModule dflags finder hit hst old_pcs this_module
87 this_mod@(HsModule _ _ _ _ _ _ loc)
88 = -- Initialise the renamer monad
90 ((maybe_rn_stuff, dump_action), (rn_warns_bag, rn_errs_bag), new_pcs)
91 <- initRn dflags finder hit hst old_pcs this_module loc (rename this_module this_mod) ;
94 printErrorsAndWarnings (rn_warns_bag, rn_errs_bag) ;
96 -- Dump any debugging output
100 if not (isEmptyBag rn_errs_bag) then
101 return (old_pcs, Nothing)
103 return (new_pcs, maybe_rn_stuff)
108 rename :: Module -> RdrNameHsModule -> RnMG (Maybe ModIface, IO ())
109 rename this_module this_mod@(HsModule mod_name vers exports imports local_decls mod_deprec loc)
110 = -- FIND THE GLOBAL NAME ENVIRONMENT
111 getGlobalNames this_mod `thenRn` \ maybe_stuff ->
113 -- CHECK FOR EARLY EXIT
114 case maybe_stuff of {
115 Nothing -> -- Everything is up to date; no need to recompile further
116 rnDump [] [] `thenRn` \ dump_action ->
117 returnRn (Nothing, dump_action) ;
119 Just (gbl_env, local_gbl_env, export_avails, global_avail_env) ->
121 -- DEAL WITH DEPRECATIONS
122 rnDeprecs local_gbl_env mod_deprec local_decls `thenRn` \ my_deprecs ->
124 -- DEAL WITH LOCAL FIXITIES
125 fixitiesFromLocalDecls local_gbl_env local_decls `thenRn` \ local_fixity_env ->
128 initRnMS gbl_env local_fixity_env SourceMode (
129 rnSourceDecls local_decls
130 ) `thenRn` \ (rn_local_decls, source_fvs) ->
132 -- SLURP IN ALL THE NEEDED DECLARATIONS
133 implicitFVs mod_name rn_local_decls `thenRn` \ implicit_fvs ->
135 -- The export_fvs make the exported names look just as if they
136 -- occurred in the source program. For the reasoning, see the
137 -- comments with RnIfaces.getImportVersions.
138 -- We only need the 'parent name' of the avail;
139 -- that's enough to suck in the declaration.
140 export_fvs = mkNameSet (map availName export_avails)
141 real_source_fvs = source_fvs `plusFV` export_fvs
143 slurp_fvs = implicit_fvs `plusFV` real_source_fvs
144 -- It's important to do the "plus" this way round, so that
145 -- when compiling the prelude, locally-defined (), Bool, etc
146 -- override the implicit ones.
148 slurpImpDecls slurp_fvs `thenRn` \ rn_imp_decls ->
150 -- EXIT IF ERRORS FOUND
151 rnDump rn_imp_decls rn_local_decls `thenRn` \ dump_action ->
152 checkErrsRn `thenRn` \ no_errs_so_far ->
153 if not no_errs_so_far then
154 -- Found errors already, so exit now
155 returnRn (Nothing, dump_action)
158 -- GENERATE THE VERSION/USAGE INFO
159 mkImportInfo mod_name imports `thenRn` \ my_usages ->
161 -- RETURN THE RENAMED MODULE
162 getNameSupplyRn `thenRn` \ name_supply ->
163 getIfacesRn `thenRn` \ ifaces ->
165 direct_import_mods :: [ModuleName]
166 direct_import_mods = nub [m | ImportDecl m _ _ _ _ _ <- imports]
168 -- *don't* just pick the forward edges. It's entirely possible
169 -- that a module is only reachable via back edges.
170 user_import ImportByUser = True
171 user_import ImportByUserSource = True
172 user_import _ = False
174 -- Export only those fixities that are for names that are
175 -- (a) defined in this module
178 = mkNameEnv [ (name, fixity)
179 | FixitySig name fixity loc <- nameEnvElts local_fixity_env,
180 isUserExportedName name
184 -- Sort the exports to make them easier to compare for versions
185 my_exports = sortAvails export_avails
187 mod_iface = ModIface { mi_module = this_module,
188 mi_version = panic "mi_version: not filled in yet",
189 mi_orphan = any isOrphanDecl rn_local_decls,
190 mi_exports = my_exports,
191 mi_usages = my_usages,
192 mi_fixities = exported_fixities,
193 mi_deprecs = my_deprecs,
194 mi_decls = rn_local_decls ++ rn_imp_decls
198 -- REPORT UNUSED NAMES, AND DEBUG DUMP
199 reportUnusedNames mod_name direct_import_mods
200 gbl_env global_avail_env
201 export_avails source_fvs
202 rn_imp_decls `thenRn_`
204 returnRn (Just mod_iface, dump_action) }
206 trashed_exports = {-trace "rnSource:trashed_exports"-} Nothing
207 trashed_imports = {-trace "rnSource:trashed_imports"-} []
210 @implicitFVs@ forces the renamer to slurp in some things which aren't
211 mentioned explicitly, but which might be needed by the type checker.
214 implicitFVs mod_name decls
215 = lookupOrigNames implicit_occs `thenRn` \ implicit_names ->
216 returnRn (mkNameSet (map getName default_tycons) `plusFV`
219 -- Add occurrences for Int, and (), because they
220 -- are the types to which ambigious type variables may be defaulted by
221 -- the type checker; so they won't always appear explicitly.
222 -- [The () one is a GHC extension for defaulting CCall results.]
223 -- ALSO: funTyCon, since it occurs implicitly everywhere!
224 -- (we don't want to be bothered with making funTyCon a
225 -- free var at every function application!)
226 -- Double is dealt with separately in getGates
227 default_tycons = [unitTyCon, funTyCon, boolTyCon, intTyCon]
229 -- Add occurrences for IO or PrimIO
230 implicit_main | mod_name == mAIN_Name
231 || mod_name == pREL_MAIN_Name = [ioTyCon_RDR]
234 -- Now add extra "occurrences" for things that
235 -- the deriving mechanism, or defaulting, will later need in order to
237 implicit_occs = string_occs ++ foldr ((++) . get) implicit_main decls
239 -- Virtually every program has error messages in it somewhere
240 string_occs = [unpackCString_RDR, unpackCStringFoldr_RDR, unpackCStringUtf8_RDR,
243 get (TyClD (TyData _ _ _ _ _ _ (Just deriv_classes) _ _ _ _))
244 = concat (map get_deriv deriv_classes)
247 get_deriv cls = case lookupUFM derivingOccurrences cls of
253 isOrphanDecl (InstD (InstDecl inst_ty _ _ _ _))
254 = not (foldNameSet ((||) . isLocallyDefined) False (extractHsTyNames (removeContext inst_ty)))
255 -- The 'removeContext' is because of
256 -- instance Foo a => Baz T where ...
257 -- The decl is an orphan if Baz and T are both not locally defined,
258 -- even if Foo *is* locally defined
260 isOrphanDecl (RuleD (HsRule _ _ _ lhs _ _))
263 -- At the moment we just check for common LHS forms
264 -- Expand as necessary. Getting it wrong just means
265 -- more orphans than necessary
266 check (HsVar v) = not (isLocallyDefined v)
267 check (HsApp f a) = check f && check a
268 check (HsLit _) = False
269 check (HsOverLit _) = False
270 check (OpApp l o _ r) = check l && check o && check r
271 check (NegApp e _) = check e
272 check (HsPar e) = check e
273 check (SectionL e o) = check e && check o
274 check (SectionR o e) = check e && check o
276 check other = True -- Safe fall through
278 isOrphanDecl other = False
283 dupDefaultDeclErrRn (DefaultDecl _ locn1 : dup_things)
284 = pushSrcLocRn locn1 $
287 msg = hang (ptext SLIT("Multiple default declarations"))
288 4 (vcat (map pp dup_things))
289 pp (DefaultDecl _ locn) = ptext SLIT("here was another default declaration") <+> ppr locn
293 %*********************************************************
295 \subsection{Slurping declarations}
297 %*********************************************************
300 -------------------------------------------------------
301 slurpImpDecls source_fvs
302 = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_`
304 -- The current slurped-set records all local things
305 getSlurped `thenRn` \ source_binders ->
306 slurpSourceRefs source_binders source_fvs `thenRn` \ (decls, needed) ->
308 -- Then get everything else
309 closeDecls decls needed `thenRn` \ decls1 ->
311 -- Finally, get any deferred data type decls
312 slurpDeferredDecls decls1 `thenRn` \ final_decls ->
316 -------------------------------------------------------
317 slurpSourceRefs :: NameSet -- Variables defined in source
318 -> FreeVars -- Variables referenced in source
319 -> RnMG ([RenamedHsDecl],
320 FreeVars) -- Un-satisfied needs
321 -- The declaration (and hence home module) of each gate has
322 -- already been loaded
324 slurpSourceRefs source_binders source_fvs
325 = go_outer [] -- Accumulating decls
326 emptyFVs -- Unsatisfied needs
327 emptyFVs -- Accumulating gates
328 (nameSetToList source_fvs) -- Things whose defn hasn't been loaded yet
330 -- The outer loop repeatedly slurps the decls for the current gates
331 -- and the instance decls
333 -- The outer loop is needed because consider
334 -- instance Foo a => Baz (Maybe a) where ...
335 -- It may be that @Baz@ and @Maybe@ are used in the source module,
336 -- but not @Foo@; so we need to chase @Foo@ too.
338 -- We also need to follow superclass refs. In particular, 'chasing @Foo@' must
339 -- include actually getting in Foo's class decl
340 -- class Wib a => Foo a where ..
341 -- so that its superclasses are discovered. The point is that Wib is a gate too.
342 -- We do this for tycons too, so that we look through type synonyms.
344 go_outer decls fvs all_gates []
345 = returnRn (decls, fvs)
347 go_outer decls fvs all_gates refs -- refs are not necessarily slurped yet
348 = traceRn (text "go_outer" <+> ppr refs) `thenRn_`
349 foldlRn go_inner (decls, fvs, emptyFVs) refs `thenRn` \ (decls1, fvs1, gates1) ->
350 getImportedInstDecls (all_gates `plusFV` gates1) `thenRn` \ inst_decls ->
351 rnInstDecls decls1 fvs1 gates1 inst_decls `thenRn` \ (decls2, fvs2, gates2) ->
352 go_outer decls2 fvs2 (all_gates `plusFV` gates2)
353 (nameSetToList (gates2 `minusNameSet` all_gates))
354 -- Knock out the all_gates because even if we don't slurp any new
355 -- decls we can get some apparently-new gates from wired-in names
357 go_inner (decls, fvs, gates) wanted_name
358 = importDecl wanted_name `thenRn` \ import_result ->
359 case import_result of
360 AlreadySlurped -> returnRn (decls, fvs, gates)
361 WiredIn -> returnRn (decls, fvs, gates `plusFV` getWiredInGates wanted_name)
362 Deferred -> returnRn (decls, fvs, gates `addOneFV` wanted_name) -- It's a type constructor
364 HereItIs decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) ->
365 returnRn (new_decl : decls,
367 gates `plusFV` getGates source_fvs new_decl)
369 rnInstDecls decls fvs gates []
370 = returnRn (decls, fvs, gates)
371 rnInstDecls decls fvs gates (d:ds)
372 = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) ->
373 rnInstDecls (new_decl:decls)
375 (gates `plusFV` getInstDeclGates new_decl)
381 -------------------------------------------------------
382 -- closeDecls keeps going until the free-var set is empty
383 closeDecls decls needed
384 | not (isEmptyFVs needed)
385 = slurpDecls decls needed `thenRn` \ (decls1, needed1) ->
386 closeDecls decls1 needed1
389 = getImportedRules `thenRn` \ rule_decls ->
391 [] -> returnRn decls -- No new rules, so we are done
392 other -> rnIfaceDecls decls emptyFVs rule_decls `thenRn` \ (decls1, needed1) ->
393 closeDecls decls1 needed1
396 -------------------------------------------------------
397 -- Augment decls with any decls needed by needed.
398 -- Return also free vars of the new decls (only)
399 slurpDecls decls needed
400 = go decls emptyFVs (nameSetToList needed)
402 go decls fvs [] = returnRn (decls, fvs)
403 go decls fvs (ref:refs) = slurpDecl decls fvs ref `thenRn` \ (decls1, fvs1) ->
406 -------------------------------------------------------
407 slurpDecl decls fvs wanted_name
408 = importDecl wanted_name `thenRn` \ import_result ->
409 case import_result of
410 -- Found a declaration... rename it
411 HereItIs decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) ->
412 returnRn (new_decl:decls, fvs1 `plusFV` fvs)
414 -- No declaration... (wired in thing, or deferred, or already slurped)
415 other -> returnRn (decls, fvs)
418 -------------------------------------------------------
419 rnIfaceDecls :: [RenamedHsDecl] -> FreeVars
420 -> [(Module, RdrNameHsDecl)]
421 -> RnM d ([RenamedHsDecl], FreeVars)
422 rnIfaceDecls decls fvs [] = returnRn (decls, fvs)
423 rnIfaceDecls decls fvs (d:ds) = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) ->
424 rnIfaceDecls (new_decl:decls) (fvs1 `plusFV` fvs) ds
426 rnIfaceDecl (mod, decl) = initIfaceRnMS mod (rnDecl decl)
430 %*********************************************************
432 \subsection{Deferred declarations}
434 %*********************************************************
436 The idea of deferred declarations is this. Suppose we have a function
441 Then we don't want to load T and all its constructors, and all
442 the types those constructors refer to, and all the types *those*
443 constructors refer to, and so on. That might mean loading many more
444 interface files than is really necessary. So we 'defer' loading T.
446 But f might be strict, and the calling convention for evaluating
447 values of type T depends on how many constructors T has, so
448 we do need to load T, but not the full details of the type T.
449 So we load the full decl for T, but only skeleton decls for A and B:
451 data T = {- 2 constructors -}
453 Whether all this is worth it is moot.
456 slurpDeferredDecls :: [RenamedHsDecl] -> RnMG [RenamedHsDecl]
457 slurpDeferredDecls decls = returnRn decls
460 slurpDeferredDecls :: [RenamedHsDecl] -> RnMG [RenamedHsDecl]
461 slurpDeferredDecls decls
462 = getDeferredDecls `thenRn` \ def_decls ->
463 rnIfaceDecls decls emptyFVs (map stripDecl def_decls) `thenRn` \ (decls1, fvs) ->
464 ASSERT( isEmptyFVs fvs )
467 stripDecl (mod, TyClD (TyData dt _ tc tvs _ nconstrs _ _ loc name1 name2))
468 = (mod, TyClD (TyData dt [] tc tvs [] nconstrs Nothing NoDataPragmas loc
470 -- Nuke the context and constructors
471 -- But retain the *number* of constructors!
472 -- Also the tvs will have kinds on them.
477 %*********************************************************
479 \subsection{Extracting the `gates'}
481 %*********************************************************
483 When we import a declaration like
485 data T = T1 Wibble | T2 Wobble
487 we don't want to treat @Wibble@ and @Wobble@ as gates
488 {\em unless} @T1@, @T2@ respectively are mentioned by the user program.
489 If only @T@ is mentioned
490 we want only @T@ to be a gate;
491 that way we don't suck in useless instance
492 decls for (say) @Eq Wibble@, when they can't possibly be useful.
494 @getGates@ takes a newly imported (and renamed) decl, and the free
495 vars of the source program, and extracts from the decl the gate names.
498 getGates source_fvs (SigD (IfaceSig _ ty _ _))
499 = extractHsTyNames ty
501 getGates source_fvs (TyClD (ClassDecl ctxt cls tvs _ sigs _ _ _ _ ))
502 = (delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) sigs)
504 `addOneToNameSet` cls)
505 `plusFV` maybe_double
507 get (ClassOpSig n _ ty _)
508 | n `elemNameSet` source_fvs = extractHsTyNames ty
509 | otherwise = emptyFVs
511 -- If we load any numeric class that doesn't have
512 -- Int as an instance, add Double to the gates.
513 -- This takes account of the fact that Double might be needed for
514 -- defaulting, but we don't want to load Double (and all its baggage)
515 -- if the more exotic classes aren't used at all.
516 maybe_double | nameUnique cls `elem` fractionalClassKeys
517 = unitFV (getName doubleTyCon)
521 getGates source_fvs (TyClD (TySynonym tycon tvs ty _))
522 = delListFromNameSet (extractHsTyNames ty)
524 -- A type synonym type constructor isn't a "gate" for instance decls
526 getGates source_fvs (TyClD (TyData _ ctxt tycon tvs cons _ _ _ _ _ _))
527 = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) cons)
529 `addOneToNameSet` tycon
531 get (ConDecl n _ tvs ctxt details _)
532 | n `elemNameSet` source_fvs
533 -- If the constructor is method, get fvs from all its fields
534 = delListFromNameSet (get_details details `plusFV`
535 extractHsCtxtTyNames ctxt)
537 get (ConDecl n _ tvs ctxt (RecCon fields) _)
538 -- Even if the constructor isn't mentioned, the fields
539 -- might be, as selectors. They can't mention existentially
540 -- bound tyvars (typechecker checks for that) so no need for
541 -- the deleteListFromNameSet part
542 = foldr (plusFV . get_field) emptyFVs fields
544 get other_con = emptyFVs
546 get_details (VanillaCon tys) = plusFVs (map get_bang tys)
547 get_details (InfixCon t1 t2) = get_bang t1 `plusFV` get_bang t2
548 get_details (RecCon fields) = plusFVs [get_bang t | (_, t) <- fields]
550 get_field (fs,t) | any (`elemNameSet` source_fvs) fs = get_bang t
551 | otherwise = emptyFVs
553 get_bang bty = extractHsTyNames (getBangType bty)
555 getGates source_fvs other_decl = emptyFVs
558 @getWiredInGates@ is just like @getGates@, but it sees a wired-in @Name@
559 rather than a declaration.
562 getWiredInGates :: Name -> FreeVars
563 getWiredInGates name -- No classes are wired in
564 = case lookupNameEnv wiredInThingEnv name of
565 Just (AnId the_id) -> getWiredInGates_s (namesOfType (idType the_id))
569 -> getWiredInGates_s (delListFromNameSet (namesOfType ty) (map getName tyvars))
571 (tyvars,ty) = getSynTyConDefn tc
575 getWiredInGates_s names = foldr (plusFV . getWiredInGates) emptyFVs (nameSetToList names)
579 getInstDeclGates (InstD (InstDecl inst_ty _ _ _ _)) = extractHsTyNames inst_ty
580 getInstDeclGates other = emptyFVs
584 %*********************************************************
586 \subsection{Fixities}
588 %*********************************************************
591 fixitiesFromLocalDecls :: GlobalRdrEnv -> [RdrNameHsDecl] -> RnMG LocalFixityEnv
592 fixitiesFromLocalDecls gbl_env decls
593 = doptRn Opt_WarnUnusedBinds `thenRn` \ warn_unused ->
594 foldlRn (getFixities warn_unused) emptyNameEnv decls `thenRn` \ env ->
595 traceRn (text "fixity env" <+> vcat (map ppr (nameEnvElts env)))
599 getFixities :: Bool -> LocalFixityEnv -> RdrNameHsDecl -> RnMG LocalFixityEnv
600 getFixities warn_uu acc (FixD fix)
601 = fix_decl warn_uu acc fix
603 getFixities warn_uu acc (TyClD (ClassDecl _ _ _ _ sigs _ _ _ _ ))
604 = foldlRn (fix_decl warn_uu) acc [sig | FixSig sig <- sigs]
605 -- Get fixities from class decl sigs too.
606 getFixities warn_uu acc other_decl
609 fix_decl warn_uu acc sig@(FixitySig rdr_name fixity loc)
610 = -- Check for fixity decl for something not declared
611 case lookupRdrEnv gbl_env rdr_name of {
613 -> pushSrcLocRn loc (addWarnRn (unusedFixityDecl rdr_name fixity))
614 `thenRn_` returnRn acc
615 | otherwise -> returnRn acc ;
619 -- Check for duplicate fixity decl
620 case lookupNameEnv acc name of {
621 Just (FixitySig _ _ loc') -> addErrRn (dupFixityDecl rdr_name loc loc')
622 `thenRn_` returnRn acc ;
624 Nothing -> returnRn (extendNameEnv acc name (FixitySig name fixity loc))
629 %*********************************************************
631 \subsection{Deprecations}
633 %*********************************************************
635 For deprecations, all we do is check that the names are in scope.
636 It's only imported deprecations, dealt with in RnIfaces, that we
637 gather them together.
640 rnDeprecs :: GlobalRdrEnv -> Maybe DeprecTxt
641 -> [RdrNameHsDecl] -> RnMG [RdrNameDeprecation]
642 rnDeprecs gbl_env mod_deprec decls
643 = mapRn rn_deprec deprecs `thenRn_`
644 returnRn (extra_deprec ++ deprecs)
646 deprecs = [d | DeprecD d <- decls]
647 extra_deprec = case mod_deprec of
649 Just txt -> [Deprecation (IEModuleContents undefined) txt noSrcLoc]
651 rn_deprec (Deprecation ie txt loc)
653 mapRn check (ieNames ie)
655 check n = case lookupRdrEnv gbl_env n of
656 Nothing -> addErrRn (unknownNameErr n)
657 Just _ -> returnRn ()
661 %*********************************************************
663 \subsection{Unused names}
665 %*********************************************************
668 reportUnusedNames :: ModuleName -> [ModuleName]
669 -> GlobalRdrEnv -> AvailEnv
670 -> Avails -> NameSet -> [RenamedHsDecl]
672 reportUnusedNames mod_name direct_import_mods
674 export_avails mentioned_names
676 = warnUnusedModules unused_imp_mods `thenRn_`
677 warnUnusedLocalBinds bad_locals `thenRn_`
678 warnUnusedImports bad_imp_names `thenRn_`
679 printMinimalImports mod_name minimal_imports `thenRn_`
680 warnDeprecations really_used_names `thenRn_`
684 used_names = mentioned_names `unionNameSets` availsToNameSet export_avails
686 -- Now, a use of C implies a use of T,
687 -- if C was brought into scope by T(..) or T(C)
688 really_used_names = used_names `unionNameSets`
689 mkNameSet [ parent_name
690 | sub_name <- nameSetToList used_names
692 -- Usually, every used name will appear in avail_env, but there
693 -- is one time when it doesn't: tuples and other built in syntax. When you
694 -- write (a,b) that gives rise to a *use* of "(,)", so that the
695 -- instances will get pulled in, but the tycon "(,)" isn't actually
696 -- in scope. Also, (-x) gives rise to an implicit use of 'negate';
697 -- similarly, 3.5 gives rise to an implcit use of :%
698 -- Hence the silent 'False' in all other cases
700 , Just parent_name <- [case lookupNameEnv avail_env sub_name of
701 Just (AvailTC n _) -> Just n
705 defined_names, defined_and_used, defined_but_not_used :: [(Name,Provenance)]
706 defined_names = concat (rdrEnvElts gbl_env)
707 (defined_and_used, defined_but_not_used) = partition used defined_names
708 used (name,_) = not (name `elemNameSet` really_used_names)
710 -- Filter out the ones only defined implicitly
712 bad_locals = [n | (n,LocalDef) <- defined_but_not_used]
714 bad_imp_names :: [(Name,Provenance)]
715 bad_imp_names = [(n,p) | (n,p@(NonLocalDef (UserImport mod _ True) _)) <- defined_but_not_used,
716 not (module_unused mod)]
718 -- inst_mods are directly-imported modules that
719 -- contain instance decl(s) that the renamer decided to suck in
720 -- It's not necessarily redundant to import such modules.
726 -- The import M() is not *necessarily* redundant, even if
727 -- we suck in no instance decls from M (e.g. it contains
728 -- no instance decls, or This contains no code). It may be
729 -- that we import M solely to ensure that M's orphan instance
730 -- decls (or those in its imports) are visible to people who
731 -- import This. Sigh.
732 -- There's really no good way to detect this, so the error message
733 -- in RnEnv.warnUnusedModules is weakened instead
734 inst_mods :: [ModuleName]
735 inst_mods = [m | InstD (InstDecl _ _ _ (Just dfun) _) <- imported_decls,
736 let m = moduleName (nameModule dfun),
737 m `elem` direct_import_mods
740 -- To figure out the minimal set of imports, start with the things
741 -- that are in scope (i.e. in gbl_env). Then just combine them
742 -- into a bunch of avails, so they are properly grouped
743 minimal_imports :: FiniteMap ModuleName AvailEnv
744 minimal_imports0 = emptyFM
745 minimal_imports1 = foldr add_name minimal_imports0 defined_and_used
746 minimal_imports = foldr add_inst_mod minimal_imports1 inst_mods
748 add_name (n,NonLocalDef (UserImport m _ _) _) acc = addToFM_C plusAvailEnv acc (moduleName (nameModule n))
749 (unitAvailEnv (mk_avail n))
750 add_name (n,other_prov) acc = acc
752 mk_avail n = case lookupNameEnv avail_env n of
753 Just (AvailTC m _) | n==m -> AvailTC n [n]
754 | otherwise -> AvailTC m [n,m]
755 Just avail -> Avail n
756 Nothing -> pprPanic "mk_avail" (ppr n)
759 | m `elemFM` acc = acc -- We import something already
760 | otherwise = addToFM acc m emptyAvailEnv
761 -- Add an empty collection of imports for a module
762 -- from which we have sucked only instance decls
764 -- unused_imp_mods are the directly-imported modules
765 -- that are not mentioned in minimal_imports
766 unused_imp_mods = [m | m <- direct_import_mods,
767 not (maybeToBool (lookupFM minimal_imports m)),
770 module_unused :: Module -> Bool
771 module_unused mod = moduleName mod `elem` unused_imp_mods
774 warnDeprecations used_names
775 = doptRn Opt_WarnDeprecations `thenRn` \ warn_drs ->
776 if not warn_drs then returnRn () else
778 getIfacesRn `thenRn` \ ifaces ->
779 getHomeIfaceTableRn `thenRn` \ hit ->
783 | n <- nameSetToList used_names,
784 Just txt <- [lookup_deprec hit pit n] ]
786 mapRn_ warnDeprec deprecs
789 lookup_deprec hit pit n
790 = case lookupModuleEnv hit mod of
791 Just iface -> lookupDeprec iface n
792 Nothing -> case lookupModuleEnv pit mod of
793 Just iface -> lookupDeprec iface n
794 Nothing -> pprPanic "warnDeprecations:" (ppr n)
798 -- ToDo: deal with original imports with 'qualified' and 'as M' clauses
799 printMinimalImports mod_name imps
800 = doptRn Opt_D_dump_minimal_imports `thenRn` \ dump_minimal ->
801 if not dump_minimal then returnRn () else
803 mapRn to_ies (fmToList imps) `thenRn` \ mod_ies ->
804 ioToRnM (do { h <- openFile filename WriteMode ;
805 printForUser h (vcat (map ppr_mod_ie mod_ies))
809 filename = moduleNameUserString mod_name ++ ".imports"
810 ppr_mod_ie (mod_name, ies)
811 | mod_name == pRELUDE_Name
814 = ptext SLIT("import") <+> ppr mod_name <>
815 parens (fsep (punctuate comma (map ppr ies)))
817 to_ies (mod, avail_env) = mapRn to_ie (availEnvElts avail_env) `thenRn` \ ies ->
820 to_ie :: AvailInfo -> RnMG (IE Name)
821 to_ie (Avail n) = returnRn (IEVar n)
822 to_ie (AvailTC n [m]) = ASSERT( n==m )
823 returnRn (IEThingAbs n)
824 to_ie (AvailTC n ns) = getInterfaceExports (moduleName (nameModule n))
825 ImportBySystem `thenRn` \ (_, avails) ->
826 case [ms | AvailTC m ms <- avails, m == n] of
827 [ms] | all (`elem` ns) ms -> returnRn (IEThingAll n)
828 | otherwise -> returnRn (IEThingWith n (filter (/= n) ns))
829 other -> pprTrace "to_ie" (ppr n <+> ppr (nameModule n) <+> ppr other) $
832 rnDump :: [RenamedHsDecl] -- Renamed imported decls
833 -> [RenamedHsDecl] -- Renamed local decls
835 rnDump imp_decls local_decls
836 = doptRn Opt_D_dump_rn_trace `thenRn` \ dump_rn_trace ->
837 doptRn Opt_D_dump_rn_stats `thenRn` \ dump_rn_stats ->
838 doptRn Opt_D_dump_rn `thenRn` \ dump_rn ->
839 if dump_rn_trace || dump_rn_stats || dump_rn then
840 getRnStats imp_decls `thenRn` \ stats_msg ->
841 returnRn (printErrs stats_msg >>
842 dumpIfSet dump_rn "Renamer:"
843 (vcat (map ppr (local_decls ++ imp_decls))))
849 %*********************************************************
851 \subsection{Statistics}
853 %*********************************************************
856 getRnStats :: [RenamedHsDecl] -> RnMG SDoc
857 getRnStats imported_decls
858 = getIfacesRn `thenRn` \ ifaces ->
860 n_mods = length [() | (_, _, True) <- eltsFM (iImpModInfo ifaces)]
862 decls_read = [decl | (avail, True, (_,decl)) <- nameEnvElts (iDecls ifaces),
863 -- Data, newtype, and class decls are in the decls_fm
864 -- under multiple names; the tycon/class, and each
865 -- constructor/class op too.
866 -- The 'True' selects just the 'main' decl
867 not (isLocallyDefined (availName avail))
870 (cd_rd, dd_rd, nd_rd, sd_rd, vd_rd, _) = count_decls decls_read
871 (cd_sp, dd_sp, nd_sp, sd_sp, vd_sp, id_sp) = count_decls imported_decls
873 unslurped_insts = iInsts ifaces
874 inst_decls_unslurped = length (bagToList unslurped_insts)
875 inst_decls_read = id_sp + inst_decls_unslurped
878 [int n_mods <+> text "interfaces read",
879 hsep [ int cd_sp, text "class decls imported, out of",
880 int cd_rd, text "read"],
881 hsep [ int dd_sp, text "data decls imported, out of",
882 int dd_rd, text "read"],
883 hsep [ int nd_sp, text "newtype decls imported, out of",
884 int nd_rd, text "read"],
885 hsep [int sd_sp, text "type synonym decls imported, out of",
886 int sd_rd, text "read"],
887 hsep [int vd_sp, text "value signatures imported, out of",
888 int vd_rd, text "read"],
889 hsep [int id_sp, text "instance decls imported, out of",
890 int inst_decls_read, text "read"],
891 text "cls dcls slurp" <+> fsep (map (ppr . tyClDeclName)
892 [d | TyClD d <- imported_decls, isClassDecl d]),
893 text "cls dcls read" <+> fsep (map (ppr . tyClDeclName)
894 [d | TyClD d <- decls_read, isClassDecl d])]
896 returnRn (hcat [text "Renamer stats: ", stats])
906 tycl_decls = [d | TyClD d <- decls]
907 (class_decls, data_decls, newtype_decls, syn_decls) = countTyClDecls tycl_decls
909 val_decls = length [() | SigD _ <- decls]
910 inst_decls = length [() | InstD _ <- decls]
914 %************************************************************************
916 \subsection{Errors and warnings}
918 %************************************************************************
921 warnDeprec :: (Name, DeprecTxt) -> RnM d ()
922 warnDeprec (name, txt)
923 = pushSrcLocRn (getSrcLoc name) $
925 sep [ text (occNameFlavour (nameOccName name)) <+> ppr name <+>
926 text "is deprecated:", nest 4 (ppr txt) ]
929 unusedFixityDecl rdr_name fixity
930 = hsep [ptext SLIT("Unused fixity declaration for"), quotes (ppr rdr_name)]
932 dupFixityDecl rdr_name loc1 loc2
933 = vcat [ptext SLIT("Multiple fixity declarations for") <+> quotes (ppr rdr_name),
934 ptext SLIT("at ") <+> ppr loc1,
935 ptext SLIT("and") <+> ppr loc2]
939 %********************************************************
941 \subsection{Checking usage information}
943 %********************************************************
947 checkEarlyExit mod_name
948 = traceRn (text "Considering whether compilation is required...") `thenRn_`
950 -- Read the old interface file, if any, for the module being compiled
951 findAndReadIface doc_str mod_name False {- Not hi-boot -} `thenRn` \ maybe_iface ->
953 -- CHECK WHETHER WE HAVE IT ALREADY
955 Left err -> -- Old interface file not found, so we'd better bail out
956 traceRn (vcat [ptext SLIT("No old interface file for") <+> ppr mod_name,
958 returnRn (outOfDate, Nothing)
961 | panic "checkEarlyExit: ???: not opt_SourceUnchanged"
962 -> -- Source code changed
963 traceRn (nest 4 (text "source file changed or recompilation check turned off")) `thenRn_`
964 returnRn (False, Just iface)
967 -> -- Source code unchanged and no errors yet... carry on
968 checkModUsage (pi_usages iface) `thenRn` \ up_to_date ->
969 returnRn (up_to_date, Just iface)
971 -- Only look in current directory, with suffix .hi
972 doc_str = sep [ptext SLIT("need usage info from"), ppr mod_name]
979 checkModUsage :: [ImportVersion OccName] -> RnMG Bool
980 -- Given the usage information extracted from the old
981 -- M.hi file for the module being compiled, figure out
982 -- whether M needs to be recompiled.
984 checkModUsage [] = returnRn upToDate -- Yes! Everything is up to date!
986 checkModUsage ((mod_name, _, _, NothingAtAll) : rest)
987 -- If CurrentModule.hi contains
989 -- then that simply records that Foo lies below CurrentModule in the
990 -- hierarchy, but CurrentModule doesn't depend in any way on Foo.
991 -- In this case we don't even want to open Foo's interface.
992 = traceRn (ptext SLIT("Nothing used from:") <+> ppr mod_name) `thenRn_`
993 checkModUsage rest -- This one's ok, so check the rest
995 checkModUsage ((mod_name, _, _, whats_imported) : rest)
996 = tryLoadInterface doc_str mod_name ImportBySystem `thenRn` \ (ifaces, maybe_err) ->
998 Just err -> out_of_date (sep [ptext SLIT("Can't find version number for module"),
1000 -- Couldn't find or parse a module mentioned in the
1001 -- old interface file. Don't complain -- it might just be that
1002 -- the current module doesn't need that import and it's been deleted
1006 (_, new_mod_vers, new_fix_vers, new_rule_vers, _, _)
1007 = case lookupFM (iImpModInfo ifaces) mod_name of
1008 Just (_, _, Just stuff) -> stuff
1010 old_mod_vers = case whats_imported of
1012 Specifically v _ _ _ -> v
1013 -- NothingAtAll case dealt with by previous eqn for checkModUsage
1015 -- If the module version hasn't changed, just move on
1016 if new_mod_vers == old_mod_vers then
1017 traceRn (sep [ptext SLIT("Module version unchanged:"), ppr mod_name])
1018 `thenRn_` checkModUsage rest
1020 traceRn (sep [ptext SLIT("Module version has changed:"), ppr mod_name])
1022 -- Module version changed, so check entities inside
1024 -- If the usage info wants to say "I imported everything from this module"
1025 -- it does so by making whats_imported equal to Everything
1026 -- In that case, we must recompile
1027 case whats_imported of { -- NothingAtAll dealt with earlier
1030 -> out_of_date (ptext SLIT("...and I needed the whole module")) ;
1032 Specifically _ old_fix_vers old_rule_vers old_local_vers ->
1034 if old_fix_vers /= new_fix_vers then
1035 out_of_date (ptext SLIT("Fixities changed"))
1036 else if old_rule_vers /= new_rule_vers then
1037 out_of_date (ptext SLIT("Rules changed"))
1039 -- Non-empty usage list, so check item by item
1040 checkEntityUsage mod_name (iDecls ifaces) old_local_vers `thenRn` \ up_to_date ->
1042 traceRn (ptext SLIT("...but the bits I use haven't.")) `thenRn_`
1043 checkModUsage rest -- This one's ok, so check the rest
1045 returnRn outOfDate -- This one failed, so just bail out now
1048 doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
1051 checkEntityUsage mod decls []
1052 = returnRn upToDate -- Yes! All up to date!
1054 checkEntityUsage mod decls ((occ_name,old_vers) : rest)
1055 = newGlobalName mod occ_name `thenRn` \ name ->
1056 case lookupNameEnv decls name of
1058 Nothing -> -- We used it before, but it ain't there now
1059 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
1061 Just (new_vers,_,_,_) -- It's there, but is it up to date?
1062 | new_vers == old_vers
1063 -- Up to date, so check the rest
1064 -> checkEntityUsage mod decls rest
1067 -- Out of date, so bale out
1068 -> out_of_date (sep [ptext SLIT("Out of date:"), ppr name])
1070 out_of_date msg = traceRn msg `thenRn_` returnRn outOfDate