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 ( dopt_D_dump_rn_trace, dopt_D_dump_minimal_imports,
19 opt_D_dump_rn, opt_D_dump_rn_stats, opt_WarnDeprecations,
23 import RnNames ( getGlobalNames )
24 import RnSource ( rnSourceDecls, rnDecl )
25 import RnIfaces ( getImportedInstDecls, importDecl, mkImportExportInfo, getInterfaceExports,
26 getImportedRules, getSlurped, removeContext,
27 loadBuiltinRules, getDeferredDecls, ImportDeclResult(..)
29 import RnEnv ( availName, availsToNameSet,
30 emptyAvailEnv, unitAvailEnv, availEnvElts, plusAvailEnv,
31 warnUnusedImports, warnUnusedLocalBinds, warnUnusedModules,
32 lookupOrigNames, unknownNameErr,
33 FreeVars, plusFVs, plusFV, unitFV, emptyFVs, isEmptyFVs, addOneFV
35 import Module ( Module, ModuleName, WhereFrom(..),
36 moduleNameUserString, mkSearchPath, moduleName, mkThisModule
38 import Name ( Name, isLocallyDefined, NamedThing(..), getSrcLoc,
39 nameOccName, nameUnique, nameModule, maybeUserImportedFrom,
40 isUserImportedExplicitlyName, isUserImportedName,
41 maybeWiredInTyConName, maybeWiredInIdName,
42 isUserExportedName, toRdrName,
43 nameEnvElts, extendNameEnv
45 import OccName ( occNameFlavour, isValOcc )
47 import TyCon ( isSynTyCon, getSynTyConDefn )
49 import TysWiredIn ( unitTyCon, intTyCon, doubleTyCon, boolTyCon )
50 import PrelRules ( builtinRules )
51 import PrelNames ( mAIN_Name, pREL_MAIN_Name, pRELUDE_Name,
53 unpackCString_RDR, unpackCStringFoldr_RDR, unpackCStringUtf8_RDR,
56 import PrelInfo ( fractionalClassKeys, derivingOccurrences )
57 import Type ( namesOfType, funTyCon )
58 import ErrUtils ( printErrorsAndWarnings, dumpIfSet, ghcExit )
59 import BasicTypes ( Version, initialVersion )
60 import Bag ( isEmptyBag, bagToList )
61 import FiniteMap ( FiniteMap, eltsFM, fmToList, emptyFM, lookupFM,
62 addToFM_C, elemFM, addToFM
64 import UniqSupply ( UniqSupply )
65 import UniqFM ( lookupUFM )
66 import SrcLoc ( noSrcLoc )
67 import Maybes ( maybeToBool, expectJust )
69 import IO ( openFile, IOMode(..) )
75 type RenameResult = ( PersistentCompilerState,
76 , Module -- This module
77 , RenamedHsModule -- Renamed module
78 , Maybe ParsedIface -- The existing interface file, if any
79 , ParsedIface -- The new interface
80 , [Module]) -- Imported modules
82 renameModule :: PersistentCompilerState -> HomeSymbolTable
83 -> RdrNameHsModule -> IO (Maybe RenameResult)
84 renameModule old_pcs hst this_mod@(HsModule mod_name vers exports imports local_decls _ loc)
85 = -- Initialise the renamer monad
87 ((maybe_rn_stuff, dump_action), msgs, new_pcs)
88 <- initRn dflags finder old_pcs hst loc (rename this_mod) ;
91 printErrorsAndWarnings msgs ;
93 -- Dump any debugging output
97 if not (isEmptyBag rn_errs_bag) then
98 return (old_pcs, Nothing)
100 return (new_pcs, maybe_rn_stuff)
105 rename :: RdrNameHsModule -> RnMG (Maybe RenameResult, IO ())
106 rename this_mod@(HsModule mod_name vers exports imports local_decls mod_deprec loc)
107 = -- FIND THE GLOBAL NAME ENVIRONMENT
108 getGlobalNames this_mod `thenRn` \ maybe_stuff ->
110 -- CHECK FOR EARLY EXIT
111 case maybe_stuff of {
112 Nothing -> -- Everything is up to date; no need to recompile further
113 rnDump [] [] `thenRn` \ dump_action ->
114 returnRn (Nothing, dump_action) ;
116 Just (gbl_env, local_gbl_env, export_avails, global_avail_env, old_iface) ->
118 -- DEAL WITH DEPRECATIONS
119 rnDeprecs local_gbl_env mod_deprec local_decls `thenRn` \ my_deprecs ->
121 -- DEAL WITH LOCAL FIXITIES
122 fixitiesFromLocalDecls local_gbl_env local_decls `thenRn` \ local_fixity_env ->
125 initRnMS gbl_env local_fixity_env SourceMode (
126 rnSourceDecls local_decls
127 ) `thenRn` \ (rn_local_decls, source_fvs) ->
129 -- SLURP IN ALL THE NEEDED DECLARATIONS
130 implicitFVs mod_name rn_local_decls `thenRn` \ implicit_fvs ->
132 -- The export_fvs make the exported names look just as if they
133 -- occurred in the source program. For the reasoning, see the
134 -- comments with RnIfaces.getImportVersions.
135 -- We only need the 'parent name' of the avail;
136 -- that's enough to suck in the declaration.
137 export_fvs = mkNameSet (map availName export_avails)
138 real_source_fvs = source_fvs `plusFV` export_fvs
140 slurp_fvs = implicit_fvs `plusFV` real_source_fvs
141 -- It's important to do the "plus" this way round, so that
142 -- when compiling the prelude, locally-defined (), Bool, etc
143 -- override the implicit ones.
145 loadBuiltinRules builtinRules `thenRn_`
146 slurpImpDecls slurp_fvs `thenRn` \ rn_imp_decls ->
148 -- EXIT IF ERRORS FOUND
149 rnDump rn_imp_decls rn_local_decls `thenRn` \ dump_action ->
150 checkErrsRn `thenRn` \ no_errs_so_far ->
151 if not no_errs_so_far then
152 -- Found errors already, so exit now
153 returnRn (Nothing, dump_action)
156 -- GENERATE THE VERSION/USAGE INFO
157 mkImportExportInfo mod_name export_avails exports `thenRn` \ (my_exports, my_usages) ->
159 -- RETURN THE RENAMED MODULE
160 getNameSupplyRn `thenRn` \ name_supply ->
161 getIfacesRn `thenRn` \ ifaces ->
163 direct_import_mods :: [Module]
164 direct_import_mods = [m | (_, _, Just (m, _, _, _, imp, _))
165 <- eltsFM (iImpModInfo ifaces), user_import imp]
167 -- *don't* just pick the forward edges. It's entirely possible
168 -- that a module is only reachable via back edges.
169 user_import ImportByUser = True
170 user_import ImportByUserSource = True
171 user_import _ = False
173 this_module = mkThisModule mod_name
175 -- Export only those fixities that are for names that are
176 -- (a) defined in this module
179 = [ FixitySig (toRdrName name) fixity loc
180 | FixitySig name fixity loc <- nameEnvElts local_fixity_env,
181 isUserExportedName name
184 new_iface = ParsedIface { pi_mod = this_module
185 , pi_vers = initialVersion
186 , pi_orphan = any isOrphanDecl rn_local_decls
187 , pi_exports = my_exports
188 , pi_usages = my_usages
189 , pi_fixity = (initialVersion, exported_fixities)
190 , pi_deprecs = my_deprecs
191 -- These ones get filled in later
192 , pi_insts = [], pi_decls = []
193 , pi_rules = (initialVersion, [])
196 renamed_module = HsModule mod_name vers
197 trashed_exports trashed_imports
198 (rn_local_decls ++ rn_imp_decls)
202 result = (this_module, renamed_module,
203 old_iface, new_iface,
204 name_supply, local_fixity_env,
208 -- REPORT UNUSED NAMES, AND DEBUG DUMP
209 reportUnusedNames mod_name direct_import_mods
210 gbl_env global_avail_env
211 export_avails source_fvs
212 rn_imp_decls `thenRn_`
214 returnRn (Just result, dump_action) }
216 trashed_exports = {-trace "rnSource:trashed_exports"-} Nothing
217 trashed_imports = {-trace "rnSource:trashed_imports"-} []
220 @implicitFVs@ forces the renamer to slurp in some things which aren't
221 mentioned explicitly, but which might be needed by the type checker.
224 implicitFVs mod_name decls
225 = lookupOrigNames implicit_occs `thenRn` \ implicit_names ->
226 returnRn (mkNameSet (map getName default_tycons) `plusFV`
229 -- Add occurrences for Int, and (), because they
230 -- are the types to which ambigious type variables may be defaulted by
231 -- the type checker; so they won't always appear explicitly.
232 -- [The () one is a GHC extension for defaulting CCall results.]
233 -- ALSO: funTyCon, since it occurs implicitly everywhere!
234 -- (we don't want to be bothered with making funTyCon a
235 -- free var at every function application!)
236 -- Double is dealt with separately in getGates
237 default_tycons = [unitTyCon, funTyCon, boolTyCon, intTyCon]
239 -- Add occurrences for IO or PrimIO
240 implicit_main | mod_name == mAIN_Name
241 || mod_name == pREL_MAIN_Name = [ioTyCon_RDR]
244 -- Now add extra "occurrences" for things that
245 -- the deriving mechanism, or defaulting, will later need in order to
247 implicit_occs = string_occs ++ foldr ((++) . get) implicit_main decls
249 -- Virtually every program has error messages in it somewhere
250 string_occs = [unpackCString_RDR, unpackCStringFoldr_RDR, unpackCStringUtf8_RDR,
253 get (TyClD (TyData _ _ _ _ _ _ (Just deriv_classes) _ _ _ _))
254 = concat (map get_deriv deriv_classes)
257 get_deriv cls = case lookupUFM derivingOccurrences cls of
263 isOrphanDecl (InstD (InstDecl inst_ty _ _ _ _))
264 = not (foldNameSet ((||) . isLocallyDefined) False (extractHsTyNames (removeContext inst_ty)))
265 -- The 'removeContext' is because of
266 -- instance Foo a => Baz T where ...
267 -- The decl is an orphan if Baz and T are both not locally defined,
268 -- even if Foo *is* locally defined
270 isOrphanDecl (RuleD (HsRule _ _ _ lhs _ _))
273 -- At the moment we just check for common LHS forms
274 -- Expand as necessary. Getting it wrong just means
275 -- more orphans than necessary
276 check (HsVar v) = not (isLocallyDefined v)
277 check (HsApp f a) = check f && check a
278 check (HsLit _) = False
279 check (HsOverLit _) = False
280 check (OpApp l o _ r) = check l && check o && check r
281 check (NegApp e _) = check e
282 check (HsPar e) = check e
283 check (SectionL e o) = check e && check o
284 check (SectionR o e) = check e && check o
286 check other = True -- Safe fall through
288 isOrphanDecl other = False
293 dupDefaultDeclErrRn (DefaultDecl _ locn1 : dup_things)
294 = pushSrcLocRn locn1 $
297 msg = hang (ptext SLIT("Multiple default declarations"))
298 4 (vcat (map pp dup_things))
299 pp (DefaultDecl _ locn) = ptext SLIT("here was another default declaration") <+> ppr locn
303 %*********************************************************
305 \subsection{Slurping declarations}
307 %*********************************************************
310 -------------------------------------------------------
311 slurpImpDecls source_fvs
312 = traceRn (text "slurpImp" <+> fsep (map ppr (nameSetToList source_fvs))) `thenRn_`
314 -- The current slurped-set records all local things
315 getSlurped `thenRn` \ source_binders ->
316 slurpSourceRefs source_binders source_fvs `thenRn` \ (decls, needed) ->
318 -- Then get everything else
319 closeDecls decls needed `thenRn` \ decls1 ->
321 -- Finally, get any deferred data type decls
322 slurpDeferredDecls decls1 `thenRn` \ final_decls ->
326 -------------------------------------------------------
327 slurpSourceRefs :: NameSet -- Variables defined in source
328 -> FreeVars -- Variables referenced in source
329 -> RnMG ([RenamedHsDecl],
330 FreeVars) -- Un-satisfied needs
331 -- The declaration (and hence home module) of each gate has
332 -- already been loaded
334 slurpSourceRefs source_binders source_fvs
335 = go_outer [] -- Accumulating decls
336 emptyFVs -- Unsatisfied needs
337 emptyFVs -- Accumulating gates
338 (nameSetToList source_fvs) -- Things whose defn hasn't been loaded yet
340 -- The outer loop repeatedly slurps the decls for the current gates
341 -- and the instance decls
343 -- The outer loop is needed because consider
344 -- instance Foo a => Baz (Maybe a) where ...
345 -- It may be that @Baz@ and @Maybe@ are used in the source module,
346 -- but not @Foo@; so we need to chase @Foo@ too.
348 -- We also need to follow superclass refs. In particular, 'chasing @Foo@' must
349 -- include actually getting in Foo's class decl
350 -- class Wib a => Foo a where ..
351 -- so that its superclasses are discovered. The point is that Wib is a gate too.
352 -- We do this for tycons too, so that we look through type synonyms.
354 go_outer decls fvs all_gates []
355 = returnRn (decls, fvs)
357 go_outer decls fvs all_gates refs -- refs are not necessarily slurped yet
358 = traceRn (text "go_outer" <+> ppr refs) `thenRn_`
359 foldlRn go_inner (decls, fvs, emptyFVs) refs `thenRn` \ (decls1, fvs1, gates1) ->
360 getImportedInstDecls (all_gates `plusFV` gates1) `thenRn` \ inst_decls ->
361 rnInstDecls decls1 fvs1 gates1 inst_decls `thenRn` \ (decls2, fvs2, gates2) ->
362 go_outer decls2 fvs2 (all_gates `plusFV` gates2)
363 (nameSetToList (gates2 `minusNameSet` all_gates))
364 -- Knock out the all_gates because even if we don't slurp any new
365 -- decls we can get some apparently-new gates from wired-in names
367 go_inner (decls, fvs, gates) wanted_name
368 = importDecl wanted_name `thenRn` \ import_result ->
369 case import_result of
370 AlreadySlurped -> returnRn (decls, fvs, gates)
371 WiredIn -> returnRn (decls, fvs, gates `plusFV` getWiredInGates wanted_name)
372 Deferred -> returnRn (decls, fvs, gates `addOneFV` wanted_name) -- It's a type constructor
374 HereItIs decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) ->
375 returnRn (new_decl : decls,
377 gates `plusFV` getGates source_fvs new_decl)
379 rnInstDecls decls fvs gates []
380 = returnRn (decls, fvs, gates)
381 rnInstDecls decls fvs gates (d:ds)
382 = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) ->
383 rnInstDecls (new_decl:decls)
385 (gates `plusFV` getInstDeclGates new_decl)
391 -------------------------------------------------------
392 -- closeDecls keeps going until the free-var set is empty
393 closeDecls decls needed
394 | not (isEmptyFVs needed)
395 = slurpDecls decls needed `thenRn` \ (decls1, needed1) ->
396 closeDecls decls1 needed1
399 = getImportedRules `thenRn` \ rule_decls ->
401 [] -> returnRn decls -- No new rules, so we are done
402 other -> rnIfaceDecls decls emptyFVs rule_decls `thenRn` \ (decls1, needed1) ->
403 closeDecls decls1 needed1
406 -------------------------------------------------------
407 -- Augment decls with any decls needed by needed.
408 -- Return also free vars of the new decls (only)
409 slurpDecls decls needed
410 = go decls emptyFVs (nameSetToList needed)
412 go decls fvs [] = returnRn (decls, fvs)
413 go decls fvs (ref:refs) = slurpDecl decls fvs ref `thenRn` \ (decls1, fvs1) ->
416 -------------------------------------------------------
417 slurpDecl decls fvs wanted_name
418 = importDecl wanted_name `thenRn` \ import_result ->
419 case import_result of
420 -- Found a declaration... rename it
421 HereItIs decl -> rnIfaceDecl decl `thenRn` \ (new_decl, fvs1) ->
422 returnRn (new_decl:decls, fvs1 `plusFV` fvs)
424 -- No declaration... (wired in thing, or deferred, or already slurped)
425 other -> returnRn (decls, fvs)
428 -------------------------------------------------------
429 rnIfaceDecls :: [RenamedHsDecl] -> FreeVars
430 -> [(Module, RdrNameHsDecl)]
431 -> RnM d ([RenamedHsDecl], FreeVars)
432 rnIfaceDecls decls fvs [] = returnRn (decls, fvs)
433 rnIfaceDecls decls fvs (d:ds) = rnIfaceDecl d `thenRn` \ (new_decl, fvs1) ->
434 rnIfaceDecls (new_decl:decls) (fvs1 `plusFV` fvs) ds
436 rnIfaceDecl (mod, decl) = initIfaceRnMS mod (rnDecl decl)
440 %*********************************************************
442 \subsection{Deferred declarations}
444 %*********************************************************
446 The idea of deferred declarations is this. Suppose we have a function
451 Then we don't want to load T and all its constructors, and all
452 the types those constructors refer to, and all the types *those*
453 constructors refer to, and so on. That might mean loading many more
454 interface files than is really necessary. So we 'defer' loading T.
456 But f might be strict, and the calling convention for evaluating
457 values of type T depends on how many constructors T has, so
458 we do need to load T, but not the full details of the type T.
459 So we load the full decl for T, but only skeleton decls for A and B:
461 data T = {- 2 constructors -}
463 Whether all this is worth it is moot.
466 slurpDeferredDecls :: [RenamedHsDecl] -> RnMG [RenamedHsDecl]
467 slurpDeferredDecls decls
468 = getDeferredDecls `thenRn` \ def_decls ->
469 rnIfaceDecls decls emptyFVs (map stripDecl def_decls) `thenRn` \ (decls1, fvs) ->
470 ASSERT( isEmptyFVs fvs )
473 stripDecl (mod, TyClD (TyData dt _ tc tvs _ nconstrs _ _ loc name1 name2))
474 = (mod, TyClD (TyData dt [] tc tvs [] nconstrs Nothing NoDataPragmas loc
476 -- Nuke the context and constructors
477 -- But retain the *number* of constructors!
478 -- Also the tvs will have kinds on them.
482 %*********************************************************
484 \subsection{Extracting the `gates'}
486 %*********************************************************
488 When we import a declaration like
490 data T = T1 Wibble | T2 Wobble
492 we don't want to treat @Wibble@ and @Wobble@ as gates
493 {\em unless} @T1@, @T2@ respectively are mentioned by the user program.
494 If only @T@ is mentioned
495 we want only @T@ to be a gate;
496 that way we don't suck in useless instance
497 decls for (say) @Eq Wibble@, when they can't possibly be useful.
499 @getGates@ takes a newly imported (and renamed) decl, and the free
500 vars of the source program, and extracts from the decl the gate names.
503 getGates source_fvs (SigD (IfaceSig _ ty _ _))
504 = extractHsTyNames ty
506 getGates source_fvs (TyClD (ClassDecl ctxt cls tvs _ sigs _ _ _ _ ))
507 = (delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) sigs)
509 `addOneToNameSet` cls)
510 `plusFV` maybe_double
512 get (ClassOpSig n _ ty _)
513 | n `elemNameSet` source_fvs = extractHsTyNames ty
514 | otherwise = emptyFVs
516 -- If we load any numeric class that doesn't have
517 -- Int as an instance, add Double to the gates.
518 -- This takes account of the fact that Double might be needed for
519 -- defaulting, but we don't want to load Double (and all its baggage)
520 -- if the more exotic classes aren't used at all.
521 maybe_double | nameUnique cls `elem` fractionalClassKeys
522 = unitFV (getName doubleTyCon)
526 getGates source_fvs (TyClD (TySynonym tycon tvs ty _))
527 = delListFromNameSet (extractHsTyNames ty)
529 -- A type synonym type constructor isn't a "gate" for instance decls
531 getGates source_fvs (TyClD (TyData _ ctxt tycon tvs cons _ _ _ _ _ _))
532 = delListFromNameSet (foldr (plusFV . get) (extractHsCtxtTyNames ctxt) cons)
534 `addOneToNameSet` tycon
536 get (ConDecl n _ tvs ctxt details _)
537 | n `elemNameSet` source_fvs
538 -- If the constructor is method, get fvs from all its fields
539 = delListFromNameSet (get_details details `plusFV`
540 extractHsCtxtTyNames ctxt)
542 get (ConDecl n _ tvs ctxt (RecCon fields) _)
543 -- Even if the constructor isn't mentioned, the fields
544 -- might be, as selectors. They can't mention existentially
545 -- bound tyvars (typechecker checks for that) so no need for
546 -- the deleteListFromNameSet part
547 = foldr (plusFV . get_field) emptyFVs fields
549 get other_con = emptyFVs
551 get_details (VanillaCon tys) = plusFVs (map get_bang tys)
552 get_details (InfixCon t1 t2) = get_bang t1 `plusFV` get_bang t2
553 get_details (RecCon fields) = plusFVs [get_bang t | (_, t) <- fields]
555 get_field (fs,t) | any (`elemNameSet` source_fvs) fs = get_bang t
556 | otherwise = emptyFVs
558 get_bang bty = extractHsTyNames (getBangType bty)
560 getGates source_fvs other_decl = emptyFVs
563 @getWiredInGates@ is just like @getGates@, but it sees a wired-in @Name@
564 rather than a declaration.
567 getWiredInGates :: Name -> FreeVars
568 getWiredInGates name -- No classes are wired in
569 | is_id = getWiredInGates_s (namesOfType (idType the_id))
570 | isSynTyCon the_tycon = getWiredInGates_s
571 (delListFromNameSet (namesOfType ty) (map getName tyvars))
572 | otherwise = unitFV name
574 maybe_wired_in_id = maybeWiredInIdName name
575 is_id = maybeToBool maybe_wired_in_id
576 maybe_wired_in_tycon = maybeWiredInTyConName name
577 Just the_id = maybe_wired_in_id
578 Just the_tycon = maybe_wired_in_tycon
579 (tyvars,ty) = getSynTyConDefn the_tycon
581 getWiredInGates_s names = foldr (plusFV . getWiredInGates) emptyFVs (nameSetToList names)
585 getInstDeclGates (InstD (InstDecl inst_ty _ _ _ _)) = extractHsTyNames inst_ty
586 getInstDeclGates other = emptyFVs
590 %*********************************************************
592 \subsection{Fixities}
594 %*********************************************************
597 fixitiesFromLocalDecls :: GlobalRdrEnv -> [RdrNameHsDecl] -> RnMG FixityEnv
598 fixitiesFromLocalDecls gbl_env decls
599 = foldlRn getFixities emptyNameEnv decls `thenRn` \ env ->
600 traceRn (text "fixity env" <+> vcat (map ppr (nameEnvElts env))) `thenRn_`
603 getFixities :: FixityEnv -> RdrNameHsDecl -> RnMG FixityEnv
604 getFixities acc (FixD fix)
607 getFixities acc (TyClD (ClassDecl _ _ _ _ sigs _ _ _ _ ))
608 = foldlRn fix_decl acc [sig | FixSig sig <- sigs]
609 -- Get fixities from class decl sigs too.
610 getFixities acc other_decl
613 fix_decl acc sig@(FixitySig rdr_name fixity loc)
614 = -- Check for fixity decl for something not declared
615 case lookupRdrEnv gbl_env rdr_name of {
616 Nothing | opt_WarnUnusedBinds
617 -> pushSrcLocRn loc (addWarnRn (unusedFixityDecl rdr_name fixity))
618 `thenRn_` returnRn acc
619 | otherwise -> returnRn acc ;
623 -- Check for duplicate fixity decl
624 case lookupNameEnv acc name of {
625 Just (FixitySig _ _ loc') -> addErrRn (dupFixityDecl rdr_name loc loc')
626 `thenRn_` returnRn acc ;
628 Nothing -> returnRn (extendNameEnv acc name (FixitySig name fixity loc))
633 %*********************************************************
635 \subsection{Deprecations}
637 %*********************************************************
639 For deprecations, all we do is check that the names are in scope.
640 It's only imported deprecations, dealt with in RnIfaces, that we
641 gather them together.
644 rnDeprecs :: GlobalRdrEnv -> Maybe DeprecTxt
645 -> [RdrNameHsDecl] -> RnMG [RdrNameDeprecation]
646 rnDeprecs gbl_env mod_deprec decls
647 = mapRn rn_deprec deprecs `thenRn_`
648 returnRn (extra_deprec ++ deprecs)
650 deprecs = [d | DeprecD d <- decls]
651 extra_deprec = case mod_deprec of
653 Just txt -> [Deprecation (IEModuleContents undefined) txt noSrcLoc]
655 rn_deprec (Deprecation ie txt loc)
657 mapRn check (ieNames ie)
659 check n = case lookupRdrEnv gbl_env n of
660 Nothing -> addErrRn (unknownNameErr n)
661 Just _ -> returnRn ()
665 %*********************************************************
667 \subsection{Unused names}
669 %*********************************************************
672 reportUnusedNames :: ModuleName -> [Module]
673 -> GlobalRdrEnv -> AvailEnv
674 -> Avails -> NameSet -> [RenamedHsDecl]
676 reportUnusedNames mod_name direct_import_mods
678 export_avails mentioned_names
681 used_names = mentioned_names `unionNameSets` availsToNameSet export_avails
683 -- Now, a use of C implies a use of T,
684 -- if C was brought into scope by T(..) or T(C)
685 really_used_names = used_names `unionNameSets`
686 mkNameSet [ availName parent_avail
687 | sub_name <- nameSetToList used_names
688 , isValOcc (getOccName sub_name)
690 -- Usually, every used name will appear in avail_env, but there
691 -- is one time when it doesn't: tuples and other built in syntax. When you
692 -- write (a,b) that gives rise to a *use* of "(,)", so that the
693 -- instances will get pulled in, but the tycon "(,)" isn't actually
694 -- in scope. Hence the isValOcc filter.
696 -- Also, (-x) gives rise to an implicit use of 'negate'; similarly,
697 -- 3.5 gives rise to an implcit use of :%
698 -- hence the isUserImportedName filter on the warning
701 = case lookupNameEnv avail_env sub_name of
703 Nothing -> WARN( isUserImportedName sub_name,
704 text "reportUnusedName: not in avail_env" <+>
708 , case parent_avail of { AvailTC _ _ -> True; other -> False }
711 defined_names, defined_but_not_used :: [(Name,Provenance)]
712 defined_names = concat (rdrEnvElts gbl_env)
713 defined_but_not_used = filter not_used defined_names
714 not_used name = not (name `elemNameSet` really_used_names)
716 -- Filter out the ones only defined implicitly
718 bad_locals = [n | (n,LocalDef) <- defined_but_not_used]
720 bad_imp_names :: [(Name,Provenance)]
721 bad_imp_names = [(n,p) | (n,p@(UserImport mod _ True) <- defined_but_not_used,
722 not (module_unused mod)]
724 deprec_used deprec_env = [ (n,txt)
725 | n <- nameSetToList mentioned_names,
726 not (isLocallyDefined n),
727 Just txt <- [lookupNameEnv deprec_env n] ]
729 -- inst_mods are directly-imported modules that
730 -- contain instance decl(s) that the renamer decided to suck in
731 -- It's not necessarily redundant to import such modules.
737 -- The import M() is not *necessarily* redundant, even if
738 -- we suck in no instance decls from M (e.g. it contains
739 -- no instance decls, or This contains no code). It may be
740 -- that we import M solely to ensure that M's orphan instance
741 -- decls (or those in its imports) are visible to people who
742 -- import This. Sigh.
743 -- There's really no good way to detect this, so the error message
744 -- in RnEnv.warnUnusedModules is weakened instead
745 inst_mods = [m | InstD (InstDecl _ _ _ (Just dfun) _) <- imported_decls,
746 let m = nameModule dfun,
747 m `elem` direct_import_mods
750 minimal_imports :: FiniteMap Module AvailEnv
751 minimal_imports0 = emptyFM
752 minimal_imports1 = foldNameSet add_name minimal_imports0 really_used_names
753 minimal_imports = foldr add_inst_mod minimal_imports1 inst_mods
755 add_name n acc = case maybeUserImportedFrom n of
757 Just m -> addToFM_C plusAvailEnv acc m
758 (unitAvailEnv (mk_avail n))
760 | m `elemFM` acc = acc -- We import something already
761 | otherwise = addToFM acc m emptyAvailEnv
762 -- Add an empty collection of imports for a module
763 -- from which we have sucked only instance decls
765 mk_avail n = case lookupNameEnv avail_env n of
766 Just (AvailTC m _) | n==m -> AvailTC n [n]
767 | otherwise -> AvailTC m [n,m]
768 Just avail -> Avail n
769 Nothing -> pprPanic "mk_avail" (ppr n)
771 -- unused_imp_mods are the directly-imported modules
772 -- that are not mentioned in minimal_imports
773 unused_imp_mods = [m | m <- direct_import_mods,
774 not (maybeToBool (lookupFM minimal_imports m)),
775 moduleName m /= pRELUDE_Name]
777 module_unused :: Module -> Bool
778 module_unused mod = mod `elem` unused_imp_mods
781 warnUnusedModules unused_imp_mods `thenRn_`
782 warnUnusedLocalBinds bad_locals `thenRn_`
783 warnUnusedImports bad_imp_names `thenRn_`
784 printMinimalImports mod_name minimal_imports `thenRn_`
785 getIfacesRn `thenRn` \ ifaces ->
786 (if opt_WarnDeprecations
787 then mapRn_ warnDeprec (deprec_used (iDeprecs ifaces))
790 -- ToDo: deal with original imports with 'qualified' and 'as M' clauses
791 printMinimalImports mod_name imps
792 | not opt_D_dump_minimal_imports
795 = mapRn to_ies (fmToList imps) `thenRn` \ mod_ies ->
796 ioToRnM (do { h <- openFile filename WriteMode ;
797 printForUser h (vcat (map ppr_mod_ie mod_ies))
801 filename = moduleNameUserString mod_name ++ ".imports"
802 ppr_mod_ie (mod_name, ies)
803 | mod_name == pRELUDE_Name
806 = ptext SLIT("import") <+> ppr mod_name <>
807 parens (fsep (punctuate comma (map ppr ies)))
809 to_ies (mod, avail_env) = mapRn to_ie (availEnvElts avail_env) `thenRn` \ ies ->
810 returnRn (moduleName mod, ies)
812 to_ie :: AvailInfo -> RnMG (IE Name)
813 to_ie (Avail n) = returnRn (IEVar n)
814 to_ie (AvailTC n [m]) = ASSERT( n==m )
815 returnRn (IEThingAbs n)
816 to_ie (AvailTC n ns) = getInterfaceExports (moduleName (nameModule n))
817 ImportBySystem `thenRn` \ (_, avails) ->
818 case [ms | AvailTC m ms <- avails, m == n] of
819 [ms] | all (`elem` ns) ms -> returnRn (IEThingAll n)
820 | otherwise -> returnRn (IEThingWith n (filter (/= n) ns))
821 other -> pprTrace "to_ie" (ppr n <+> ppr (nameModule n) <+> ppr other) $
824 rnDump :: [RenamedHsDecl] -- Renamed imported decls
825 -> [RenamedHsDecl] -- Renamed local decls
827 rnDump imp_decls local_decls
828 | opt_D_dump_rn_trace ||
829 opt_D_dump_rn_stats ||
831 = getRnStats imp_decls `thenRn` \ stats_msg ->
833 returnRn (printErrs stats_msg >>
834 dumpIfSet opt_D_dump_rn "Renamer:"
835 (vcat (map ppr (local_decls ++ imp_decls))))
837 | otherwise = returnRn (return ())
841 %*********************************************************
843 \subsection{Statistics}
845 %*********************************************************
848 getRnStats :: [RenamedHsDecl] -> RnMG SDoc
849 getRnStats imported_decls
850 = getIfacesRn `thenRn` \ ifaces ->
852 n_mods = length [() | (_, _, Just _) <- eltsFM (iImpModInfo ifaces)]
854 decls_read = [decl | (_, avail, True, (_,decl)) <- nameEnvElts (iDecls ifaces),
855 -- Data, newtype, and class decls are in the decls_fm
856 -- under multiple names; the tycon/class, and each
857 -- constructor/class op too.
858 -- The 'True' selects just the 'main' decl
859 not (isLocallyDefined (availName avail))
862 (cd_rd, dd_rd, nd_rd, sd_rd, vd_rd, _) = count_decls decls_read
863 (cd_sp, dd_sp, nd_sp, sd_sp, vd_sp, id_sp) = count_decls imported_decls
865 unslurped_insts = iInsts ifaces
866 inst_decls_unslurped = length (bagToList unslurped_insts)
867 inst_decls_read = id_sp + inst_decls_unslurped
870 [int n_mods <+> text "interfaces read",
871 hsep [ int cd_sp, text "class decls imported, out of",
872 int cd_rd, text "read"],
873 hsep [ int dd_sp, text "data decls imported, out of",
874 int dd_rd, text "read"],
875 hsep [ int nd_sp, text "newtype decls imported, out of",
876 int nd_rd, text "read"],
877 hsep [int sd_sp, text "type synonym decls imported, out of",
878 int sd_rd, text "read"],
879 hsep [int vd_sp, text "value signatures imported, out of",
880 int vd_rd, text "read"],
881 hsep [int id_sp, text "instance decls imported, out of",
882 int inst_decls_read, text "read"],
883 text "cls dcls slurp" <+> fsep (map (ppr . tyClDeclName)
884 [d | TyClD d <- imported_decls, isClassDecl d]),
885 text "cls dcls read" <+> fsep (map (ppr . tyClDeclName)
886 [d | TyClD d <- decls_read, isClassDecl d])]
888 returnRn (hcat [text "Renamer stats: ", stats])
898 tycl_decls = [d | TyClD d <- decls]
899 (class_decls, data_decls, newtype_decls, syn_decls) = countTyClDecls tycl_decls
901 val_decls = length [() | SigD _ <- decls]
902 inst_decls = length [() | InstD _ <- decls]
906 %************************************************************************
908 \subsection{Errors and warnings}
910 %************************************************************************
913 warnDeprec :: (Name, DeprecTxt) -> RnM d ()
914 warnDeprec (name, txt)
915 = pushSrcLocRn (getSrcLoc name) $
917 sep [ text (occNameFlavour (nameOccName name)) <+> ppr name <+>
918 text "is deprecated:", nest 4 (ppr txt) ]
921 unusedFixityDecl rdr_name fixity
922 = hsep [ptext SLIT("Unused fixity declaration for"), quotes (ppr rdr_name)]
924 dupFixityDecl rdr_name loc1 loc2
925 = vcat [ptext SLIT("Multiple fixity declarations for") <+> quotes (ppr rdr_name),
926 ptext SLIT("at ") <+> ppr loc1,
927 ptext SLIT("and") <+> ppr loc2]