2 % (c) The GRASP Project, Glasgow University, 1992-1998
4 \section[Rename]{Renaming and dependency analysis passes}
7 module Rename ( renameModule, renameExpr, closeIfaceDecls, checkOldIface ) where
9 #include "HsVersions.h"
12 import RdrHsSyn ( RdrNameHsModule, RdrNameHsDecl, RdrNameDeprecation, RdrNameHsExpr,
13 RdrNameTyClDecl, RdrNameRuleDecl, RdrNameInstDecl, RdrNameImportDecl
15 import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl, RenamedRuleDecl, RenamedInstDecl,
16 extractHsTyNames, RenamedHsExpr,
17 instDeclFVs, tyClDeclFVs, ruleDeclFVs
20 import CmdLineOpts ( DynFlags, DynFlag(..) )
22 import RnExpr ( rnExpr )
23 import RnNames ( getGlobalNames, exportsFromAvail )
24 import RnSource ( rnSourceDecls, rnTyClDecl, rnIfaceRuleDecl, rnInstDecl )
25 import RnIfaces ( slurpImpDecls, mkImportInfo, recordLocalSlurps,
26 getInterfaceExports, closeDecls,
27 RecompileRequired, outOfDate, recompileRequired
29 import RnHiFiles ( readIface, removeContext, loadInterface,
30 loadExports, loadFixDecls, loadDeprecs,
32 import RnEnv ( availsToNameSet, availName, mkIfaceGlobalRdrEnv,
33 emptyAvailEnv, unitAvailEnv, availEnvElts,
34 plusAvailEnv, groupAvails, warnUnusedImports,
35 warnUnusedLocalBinds, warnUnusedModules,
36 lookupOrigNames, lookupSrcName,
37 newGlobalName, unQualInScope
39 import Module ( Module, ModuleName, WhereFrom(..),
40 moduleNameUserString, moduleName,
41 moduleEnvElts, lookupModuleEnv
43 import Name ( Name, NamedThing(..), getSrcLoc,
44 nameIsLocalOrFrom, nameOccName, nameModule,
46 import Name ( mkNameEnv, nameEnvElts, extendNameEnv )
47 import RdrName ( elemRdrEnv, foldRdrEnv, isQual )
48 import OccName ( occNameFlavour )
50 import TysWiredIn ( unitTyCon, intTyCon, boolTyCon )
51 import PrelNames ( mAIN_Name, pREL_MAIN_Name, pRELUDE_Name,
52 ioTyCon_RDR, main_RDR_Unqual,
53 unpackCString_RDR, unpackCStringFoldr_RDR, unpackCStringUtf8_RDR,
56 import PrelInfo ( derivingOccurrences )
57 import Type ( funTyCon )
58 import ErrUtils ( dumpIfSet, dumpIfSet_dyn, showPass,
59 printErrorsAndWarnings, errorsFound )
60 import Bag ( bagToList )
61 import FiniteMap ( FiniteMap, fmToList, emptyFM, lookupFM,
62 addToFM_C, elemFM, addToFM
64 import UniqFM ( lookupUFM )
65 import Maybes ( maybeToBool, catMaybes )
67 import IO ( openFile, IOMode(..) )
68 import HscTypes ( PersistentCompilerState, HomeIfaceTable, HomeSymbolTable,
69 ModIface(..), WhatsImported(..),
70 VersionInfo(..), ImportVersion, IsExported,
71 IfaceDecls, mkIfaceDecls, dcl_tycl, dcl_rules, dcl_insts,
72 GlobalRdrEnv, pprGlobalRdrEnv,
73 AvailEnv, GenAvailInfo(..), AvailInfo, Avails,
74 Provenance(..), ImportReason(..), initialVersionInfo,
75 Deprecations(..), lookupDeprec, lookupIface
77 import List ( partition, nub )
83 %*********************************************************
85 \subsection{The two main wrappers}
87 %*********************************************************
90 renameModule :: DynFlags
91 -> HomeIfaceTable -> HomeSymbolTable
92 -> PersistentCompilerState
93 -> Module -> RdrNameHsModule
94 -> IO (PersistentCompilerState, Maybe (PrintUnqualified, (IsExported, ModIface, [RenamedHsDecl])))
95 -- Nothing => some error occurred in the renamer
97 renameModule dflags hit hst pcs this_module rdr_module
98 = renameSource dflags hit hst pcs this_module $
99 rename this_module rdr_module
104 renameExpr :: DynFlags
105 -> HomeIfaceTable -> HomeSymbolTable
106 -> PersistentCompilerState
107 -> Module -> RdrNameHsExpr
108 -> IO ( PersistentCompilerState,
109 Maybe (PrintUnqualified, (RenamedHsExpr, [RenamedHsDecl]))
112 renameExpr dflags hit hst pcs this_module expr
113 = do { renameSource dflags hit hst pcs this_module $
114 tryLoadInterface doc (moduleName this_module) ImportByUser
115 `thenRn` \ (iface, maybe_err) ->
117 Just msg -> ioToRnM (printErrs alwaysQualify
118 (ptext SLIT("failed to load interface for")
119 <+> quotes (ppr this_module)
120 <> char ':' <+> msg)) `thenRn_`
124 let rdr_env = mi_globals iface
125 print_unqual = unQualInScope rdr_env
128 initRnMS rdr_env emptyLocalFixityEnv SourceMode (rnExpr expr)
129 `thenRn` \ (e,fvs) ->
131 checkErrsRn `thenRn` \ no_errs_so_far ->
132 if not no_errs_so_far then
133 -- Found errors already, so exit now
134 doDump e [] `thenRn_`
138 lookupOrigNames implicit_occs `thenRn` \ implicit_names ->
139 slurpImpDecls (fvs `plusFV` implicit_names) `thenRn` \ decls ->
141 doDump e decls `thenRn_`
142 returnRn (Just (print_unqual, (e, decls)))
145 implicit_occs = string_occs
146 doc = text "context for compiling expression"
148 doDump :: RenamedHsExpr -> [RenamedHsDecl] -> RnMG (Either IOError ())
150 getDOptsRn `thenRn` \ dflags ->
151 ioToRnM (dumpIfSet_dyn dflags Opt_D_dump_rn "Renamer:"
152 (vcat (ppr e : map ppr decls)))
156 %*********************************************************
158 \subsection{The main function: rename}
160 %*********************************************************
163 renameSource :: DynFlags
164 -> HomeIfaceTable -> HomeSymbolTable
165 -> PersistentCompilerState
167 -> RnMG (Maybe (PrintUnqualified, r))
168 -> IO (PersistentCompilerState, Maybe (PrintUnqualified, r))
169 -- Nothing => some error occurred in the renamer
171 renameSource dflags hit hst old_pcs this_module thing_inside
172 = do { showPass dflags "Renamer"
174 -- Initialise the renamer monad
175 ; (new_pcs, msgs, maybe_rn_stuff) <- initRn dflags hit hst old_pcs this_module thing_inside
177 -- Print errors from renaming
178 ; let print_unqual = case maybe_rn_stuff of
179 Just (unqual, _) -> unqual
180 Nothing -> alwaysQualify
182 ; printErrorsAndWarnings print_unqual msgs ;
184 -- Return results. No harm in updating the PCS
185 ; if errorsFound msgs then
186 return (new_pcs, Nothing)
188 return (new_pcs, maybe_rn_stuff)
193 rename :: Module -> RdrNameHsModule -> RnMG (Maybe (PrintUnqualified, (IsExported, ModIface, [RenamedHsDecl])))
194 rename this_module contents@(HsModule _ _ exports imports local_decls mod_deprec loc)
197 -- FIND THE GLOBAL NAME ENVIRONMENT
198 getGlobalNames this_module contents `thenRn` \ (gbl_env, local_gbl_env, all_avails@(_, global_avail_env)) ->
200 -- Exit if we've found any errors
201 checkErrsRn `thenRn` \ no_errs_so_far ->
202 if not no_errs_so_far then
203 -- Found errors already, so exit now
204 rnDump [] [] `thenRn_`
208 -- PROCESS EXPORT LIST
209 exportsFromAvail mod_name exports all_avails gbl_env `thenRn` \ export_avails ->
211 traceRn (text "Local top-level environment" $$
212 nest 4 (pprGlobalRdrEnv local_gbl_env)) `thenRn_`
214 -- DEAL WITH DEPRECATIONS
215 rnDeprecs local_gbl_env mod_deprec
216 [d | DeprecD d <- local_decls] `thenRn` \ my_deprecs ->
218 -- DEAL WITH LOCAL FIXITIES
219 fixitiesFromLocalDecls local_gbl_env local_decls `thenRn` \ local_fixity_env ->
222 rnSourceDecls gbl_env local_fixity_env local_decls `thenRn` \ (rn_local_decls, source_fvs) ->
224 -- CHECK THAT main IS DEFINED, IF REQUIRED
225 checkMain this_module local_gbl_env `thenRn_`
227 -- EXIT IF ERRORS FOUND
228 -- We exit here if there are any errors in the source, *before*
229 -- we attempt to slurp the decls from the interfaces, otherwise
230 -- the slurped decls may get lost when we return up the stack
231 -- to hscMain/hscExpr.
232 checkErrsRn `thenRn` \ no_errs_so_far ->
233 if not no_errs_so_far then
234 -- Found errors already, so exit now
235 rnDump [] rn_local_decls `thenRn_`
239 -- SLURP IN ALL THE NEEDED DECLARATIONS
240 implicitFVs mod_name rn_local_decls `thenRn` \ implicit_fvs ->
242 slurp_fvs = implicit_fvs `plusFV` source_fvs
243 -- It's important to do the "plus" this way round, so that
244 -- when compiling the prelude, locally-defined (), Bool, etc
245 -- override the implicit ones.
247 traceRn (text "Source FVs:" <+> fsep (map ppr (nameSetToList slurp_fvs))) `thenRn_`
248 slurpImpDecls slurp_fvs `thenRn` \ rn_imp_decls ->
250 rnDump rn_imp_decls rn_local_decls `thenRn_`
252 -- GENERATE THE VERSION/USAGE INFO
253 mkImportInfo mod_name imports `thenRn` \ my_usages ->
255 -- BUILD THE MODULE INTERFACE
257 -- We record fixities even for things that aren't exported,
258 -- so that we can change into the context of this moodule easily
259 fixities = mkNameEnv [ (name, fixity)
260 | FixitySig name fixity loc <- nameEnvElts local_fixity_env
263 -- Sort the exports to make them easier to compare for versions
264 my_exports = groupAvails this_module export_avails
266 final_decls = rn_local_decls ++ rn_imp_decls
267 is_orphan = any (isOrphanDecl this_module) rn_local_decls
269 mod_iface = ModIface { mi_module = this_module,
270 mi_version = initialVersionInfo,
271 mi_usages = my_usages,
273 mi_orphan = is_orphan,
274 mi_exports = my_exports,
275 mi_globals = gbl_env,
276 mi_fixities = fixities,
277 mi_deprecs = my_deprecs,
278 mi_decls = panic "mi_decls"
281 print_unqualified = unQualInScope gbl_env
282 is_exported name = name `elemNameSet` exported_names
283 exported_names = availsToNameSet export_avails
286 -- REPORT UNUSED NAMES, AND DEBUG DUMP
287 reportUnusedNames mod_iface print_unqualified
288 imports global_avail_env
289 source_fvs export_avails rn_imp_decls `thenRn_`
291 returnRn (Just (print_unqualified, (is_exported, mod_iface, final_decls)))
293 mod_name = moduleName this_module
296 Checking that main is defined
299 checkMain :: Module -> GlobalRdrEnv -> RnMG ()
300 checkMain this_mod local_env
301 | moduleName this_mod == mAIN_Name
302 = checkRn (main_RDR_Unqual `elemRdrEnv` local_env) noMainErr
307 @implicitFVs@ forces the renamer to slurp in some things which aren't
308 mentioned explicitly, but which might be needed by the type checker.
311 implicitFVs mod_name decls
312 = lookupOrigNames implicit_occs `thenRn` \ implicit_names ->
313 returnRn (mkNameSet (map getName default_tycons) `plusFV`
316 -- Add occurrences for Int, and (), because they
317 -- are the types to which ambigious type variables may be defaulted by
318 -- the type checker; so they won't always appear explicitly.
319 -- [The () one is a GHC extension for defaulting CCall results.]
320 -- ALSO: funTyCon, since it occurs implicitly everywhere!
321 -- (we don't want to be bothered with making funTyCon a
322 -- free var at every function application!)
323 -- Double is dealt with separately in getGates
324 default_tycons = [unitTyCon, funTyCon, boolTyCon, intTyCon]
326 -- Add occurrences for IO or PrimIO
327 implicit_main | mod_name == mAIN_Name
328 || mod_name == pREL_MAIN_Name = [ioTyCon_RDR]
331 -- Now add extra "occurrences" for things that
332 -- the deriving mechanism, or defaulting, will later need in order to
334 implicit_occs = string_occs ++ foldr ((++) . get) implicit_main decls
337 get (TyClD (TyData _ _ _ _ _ _ (Just deriv_classes) _ _ _))
338 = concat (map get_deriv deriv_classes)
341 get_deriv cls = case lookupUFM derivingOccurrences cls of
345 -- Virtually every program has error messages in it somewhere
346 string_occs = [unpackCString_RDR, unpackCStringFoldr_RDR,
347 unpackCStringUtf8_RDR, eqString_RDR]
351 isOrphanDecl this_mod (InstD (InstDecl inst_ty _ _ _ _))
352 = not (foldNameSet ((||) . nameIsLocalOrFrom this_mod) False
353 (extractHsTyNames (removeContext inst_ty)))
354 -- The 'removeContext' is because of
355 -- instance Foo a => Baz T where ...
356 -- The decl is an orphan if Baz and T are both not locally defined,
357 -- even if Foo *is* locally defined
359 isOrphanDecl this_mod (RuleD (HsRule _ _ _ lhs _ _))
362 -- At the moment we just check for common LHS forms
363 -- Expand as necessary. Getting it wrong just means
364 -- more orphans than necessary
365 check (HsVar v) = not (nameIsLocalOrFrom this_mod v)
366 check (HsApp f a) = check f && check a
367 check (HsLit _) = False
368 check (HsOverLit _) = False
369 check (OpApp l o _ r) = check l && check o && check r
370 check (NegApp e _) = check e
371 check (HsPar e) = check e
372 check (SectionL e o) = check e && check o
373 check (SectionR o e) = check e && check o
375 check other = True -- Safe fall through
377 isOrphanDecl _ _ = False
381 %*********************************************************
383 \subsection{Fixities}
385 %*********************************************************
388 fixitiesFromLocalDecls :: GlobalRdrEnv -> [RdrNameHsDecl] -> RnMG LocalFixityEnv
389 fixitiesFromLocalDecls gbl_env decls
390 = foldlRn getFixities emptyNameEnv decls `thenRn` \ env ->
391 traceRn (text "fixity env" <+> vcat (map ppr (nameEnvElts env))) `thenRn_`
394 getFixities :: LocalFixityEnv -> RdrNameHsDecl -> RnMG LocalFixityEnv
395 getFixities acc (FixD fix)
398 getFixities acc (TyClD (ClassDecl _ _ _ _ sigs _ _ _ ))
399 = foldlRn fix_decl acc [sig | FixSig sig <- sigs]
400 -- Get fixities from class decl sigs too.
401 getFixities acc other_decl
404 fix_decl acc sig@(FixitySig rdr_name fixity loc)
405 = -- Check for fixity decl for something not declared
407 lookupSrcName gbl_env rdr_name `thenRn` \ name ->
409 -- Check for duplicate fixity decl
410 case lookupNameEnv acc name of
411 Just (FixitySig _ _ loc') -> addErrRn (dupFixityDecl rdr_name loc loc') `thenRn_`
414 Nothing -> returnRn (extendNameEnv acc name (FixitySig name fixity loc))
418 %*********************************************************
420 \subsection{Deprecations}
422 %*********************************************************
424 For deprecations, all we do is check that the names are in scope.
425 It's only imported deprecations, dealt with in RnIfaces, that we
426 gather them together.
429 rnDeprecs :: GlobalRdrEnv -> Maybe DeprecTxt
430 -> [RdrNameDeprecation] -> RnMG Deprecations
431 rnDeprecs gbl_env Nothing []
434 rnDeprecs gbl_env (Just txt) decls
435 = mapRn (addErrRn . badDeprec) decls `thenRn_`
436 returnRn (DeprecAll txt)
438 rnDeprecs gbl_env Nothing decls
439 = mapRn rn_deprec decls `thenRn` \ pairs ->
440 returnRn (DeprecSome (mkNameEnv (catMaybes pairs)))
442 rn_deprec (Deprecation rdr_name txt loc)
444 lookupSrcName gbl_env rdr_name `thenRn` \ name ->
445 returnRn (Just (name, (name,txt)))
449 %************************************************************************
451 \subsection{Grabbing the old interface file and checking versions}
453 %************************************************************************
456 checkOldIface :: DynFlags
457 -> HomeIfaceTable -> HomeSymbolTable
458 -> PersistentCompilerState
460 -> Bool -- Source unchanged
461 -> Maybe ModIface -- Old interface from compilation manager, if any
462 -> IO (PersistentCompilerState, Bool, (RecompileRequired, Maybe ModIface))
463 -- True <=> errors happened
465 checkOldIface dflags hit hst pcs iface_path source_unchanged maybe_iface
466 = runRn dflags hit hst pcs (panic "Bogus module") $
468 Just old_iface -> -- Use the one we already have
469 setModuleRn (mi_module old_iface) (check_versions old_iface)
471 Nothing -- try and read it from a file
472 -> readIface iface_path `thenRn` \ read_result ->
474 Left err -> -- Old interface file not found, or garbled; give up
475 traceRn (text "Bad old interface file" $$ nest 4 err) `thenRn_`
476 returnRn (outOfDate, Nothing)
479 -> setModuleRn (pi_mod parsed_iface) $
480 loadOldIface parsed_iface `thenRn` \ m_iface ->
481 check_versions m_iface
483 check_versions :: ModIface -> RnMG (RecompileRequired, Maybe ModIface)
486 recompileRequired iface_path source_unchanged iface
487 `thenRn` \ recompile ->
488 returnRn (recompile, Just iface)
491 I think the following function should now have a more representative name,
495 loadOldIface :: ParsedIface -> RnMG ModIface
497 loadOldIface parsed_iface
498 = let iface = parsed_iface
502 loadHomeDecls (pi_decls iface) `thenRn` \ decls ->
503 loadHomeRules (pi_rules iface) `thenRn` \ rules ->
504 loadHomeInsts (pi_insts iface) `thenRn` \ insts ->
505 returnRn (decls, rules, insts)
507 `thenRn` \ ((decls_vers, new_decls), (rule_vers, new_rules), new_insts) ->
509 mapRn loadHomeUsage (pi_usages iface) `thenRn` \ usages ->
510 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
511 loadFixDecls mod (pi_fixity iface) `thenRn` \ fix_env ->
512 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
514 version = VersionInfo { vers_module = pi_vers iface,
515 vers_exports = export_vers,
516 vers_rules = rule_vers,
517 vers_decls = decls_vers }
519 decls = mkIfaceDecls new_decls new_rules new_insts
521 mod_iface = ModIface { mi_module = mod, mi_version = version,
522 mi_exports = avails, mi_usages = usages,
523 mi_boot = False, mi_orphan = pi_orphan iface,
524 mi_fixities = fix_env, mi_deprecs = deprec_env,
526 mi_globals = mkIfaceGlobalRdrEnv avails
533 loadHomeDecls :: [(Version, RdrNameTyClDecl)]
534 -> RnMS (NameEnv Version, [RenamedTyClDecl])
535 loadHomeDecls decls = foldlRn loadHomeDecl (emptyNameEnv, []) decls
537 loadHomeDecl :: (NameEnv Version, [RenamedTyClDecl])
538 -> (Version, RdrNameTyClDecl)
539 -> RnMS (NameEnv Version, [RenamedTyClDecl])
540 loadHomeDecl (version_map, decls) (version, decl)
541 = rnTyClDecl decl `thenRn` \ decl' ->
542 returnRn (extendNameEnv version_map (tyClDeclName decl') version, decl':decls)
545 loadHomeRules :: (Version, [RdrNameRuleDecl])
546 -> RnMS (Version, [RenamedRuleDecl])
547 loadHomeRules (version, rules)
548 = mapRn rnIfaceRuleDecl rules `thenRn` \ rules' ->
549 returnRn (version, rules')
552 loadHomeInsts :: [RdrNameInstDecl]
553 -> RnMS [RenamedInstDecl]
554 loadHomeInsts insts = mapRn rnInstDecl insts
557 loadHomeUsage :: ImportVersion OccName
558 -> RnMG (ImportVersion Name)
559 loadHomeUsage (mod_name, orphans, is_boot, whats_imported)
560 = rn_imps whats_imported `thenRn` \ whats_imported' ->
561 returnRn (mod_name, orphans, is_boot, whats_imported')
563 rn_imps NothingAtAll = returnRn NothingAtAll
564 rn_imps (Everything v) = returnRn (Everything v)
565 rn_imps (Specifically mv ev items rv) = mapRn rn_imp items `thenRn` \ items' ->
566 returnRn (Specifically mv ev items' rv)
567 rn_imp (occ,vers) = newGlobalName mod_name occ `thenRn` \ name ->
573 %*********************************************************
575 \subsection{Closing up the interface decls}
577 %*********************************************************
579 Suppose we discover we don't need to recompile. Then we start from the
580 IfaceDecls in the ModIface, and fluff them up by sucking in all the decls they need.
583 closeIfaceDecls :: DynFlags
584 -> HomeIfaceTable -> HomeSymbolTable
585 -> PersistentCompilerState
586 -> ModIface -- Get the decls from here
587 -> IO (PersistentCompilerState, Bool, [RenamedHsDecl])
588 -- True <=> errors happened
589 closeIfaceDecls dflags hit hst pcs
590 mod_iface@(ModIface { mi_module = mod, mi_decls = iface_decls })
591 = runRn dflags hit hst pcs mod $
594 rule_decls = dcl_rules iface_decls
595 inst_decls = dcl_insts iface_decls
596 tycl_decls = dcl_tycl iface_decls
597 decls = map RuleD rule_decls ++
598 map InstD inst_decls ++
600 needed = unionManyNameSets (map ruleDeclFVs rule_decls) `unionNameSets`
601 unionManyNameSets (map instDeclFVs inst_decls) `unionNameSets`
602 unionManyNameSets (map tyClDeclFVs tycl_decls)
603 local_names = foldl add emptyNameSet tycl_decls
604 add names decl = addListToNameSet names (map fst (tyClDeclSysNames decl ++ tyClDeclNames decl))
606 -- Record that we have now got declarations for local_names
607 recordLocalSlurps local_names `thenRn_`
609 -- Do the transitive closure
610 lookupOrigNames implicit_occs `thenRn` \ implicit_names ->
611 closeDecls decls (needed `plusFV` implicit_names)
613 implicit_occs = string_occs -- Data type decls with record selectors,
614 -- which may appear in the decls, need unpackCString
615 -- and friends. It's easier to just grab them right now.
618 %*********************************************************
620 \subsection{Unused names}
622 %*********************************************************
625 reportUnusedNames :: ModIface -> PrintUnqualified
626 -> [RdrNameImportDecl]
628 -> NameSet -- Used in this module
629 -> Avails -- Exported by this module
632 reportUnusedNames my_mod_iface unqual imports avail_env
633 source_fvs export_avails imported_decls
634 = warnUnusedModules unused_imp_mods `thenRn_`
635 warnUnusedLocalBinds bad_locals `thenRn_`
636 warnUnusedImports bad_imp_names `thenRn_`
637 printMinimalImports this_mod unqual minimal_imports `thenRn_`
638 warnDeprecations this_mod export_avails my_deprecs
642 this_mod = mi_module my_mod_iface
643 gbl_env = mi_globals my_mod_iface
644 my_deprecs = mi_deprecs my_mod_iface
646 -- The export_fvs make the exported names look just as if they
647 -- occurred in the source program.
648 export_fvs = availsToNameSet export_avails
649 used_names = source_fvs `plusFV` export_fvs
651 -- Now, a use of C implies a use of T,
652 -- if C was brought into scope by T(..) or T(C)
653 really_used_names = used_names `unionNameSets`
654 mkNameSet [ parent_name
655 | sub_name <- nameSetToList used_names
657 -- Usually, every used name will appear in avail_env, but there
658 -- is one time when it doesn't: tuples and other built in syntax. When you
659 -- write (a,b) that gives rise to a *use* of "(,)", so that the
660 -- instances will get pulled in, but the tycon "(,)" isn't actually
661 -- in scope. Also, (-x) gives rise to an implicit use of 'negate';
662 -- similarly, 3.5 gives rise to an implcit use of :%
663 -- Hence the silent 'False' in all other cases
665 , Just parent_name <- [case lookupNameEnv avail_env sub_name of
666 Just (AvailTC n _) -> Just n
670 -- Collect the defined names from the in-scope environment
671 -- Look for the qualified ones only, else get duplicates
672 defined_names :: [(Name,Provenance)]
673 defined_names = foldRdrEnv add [] gbl_env
674 add rdr_name ns acc | isQual rdr_name = ns ++ acc
677 defined_and_used, defined_but_not_used :: [(Name,Provenance)]
678 (defined_and_used, defined_but_not_used) = partition used defined_names
679 used (name,_) = name `elemNameSet` really_used_names
681 -- Filter out the ones only defined implicitly
683 bad_locals = [n | (n,LocalDef) <- defined_but_not_used]
685 bad_imp_names :: [(Name,Provenance)]
686 bad_imp_names = [(n,p) | (n,p@(NonLocalDef (UserImport mod _ True))) <- defined_but_not_used,
687 not (module_unused mod)]
689 -- inst_mods are directly-imported modules that
690 -- contain instance decl(s) that the renamer decided to suck in
691 -- It's not necessarily redundant to import such modules.
697 -- The import M() is not *necessarily* redundant, even if
698 -- we suck in no instance decls from M (e.g. it contains
699 -- no instance decls, or This contains no code). It may be
700 -- that we import M solely to ensure that M's orphan instance
701 -- decls (or those in its imports) are visible to people who
702 -- import This. Sigh.
703 -- There's really no good way to detect this, so the error message
704 -- in RnEnv.warnUnusedModules is weakened instead
705 inst_mods :: [ModuleName]
706 inst_mods = [m | InstD (InstDecl _ _ _ (Just dfun) _) <- imported_decls,
707 let m = moduleName (nameModule dfun),
708 m `elem` direct_import_mods
711 -- To figure out the minimal set of imports, start with the things
712 -- that are in scope (i.e. in gbl_env). Then just combine them
713 -- into a bunch of avails, so they are properly grouped
714 minimal_imports :: FiniteMap ModuleName AvailEnv
715 minimal_imports0 = emptyFM
716 minimal_imports1 = foldr add_name minimal_imports0 defined_and_used
717 minimal_imports = foldr add_inst_mod minimal_imports1 inst_mods
719 add_name (n,NonLocalDef (UserImport m _ _)) acc = addToFM_C plusAvailEnv acc (moduleName (nameModule n))
720 (unitAvailEnv (mk_avail n))
721 add_name (n,other_prov) acc = acc
723 mk_avail n = case lookupNameEnv avail_env n of
724 Just (AvailTC m _) | n==m -> AvailTC n [n]
725 | otherwise -> AvailTC m [n,m]
726 Just avail -> Avail n
727 Nothing -> pprPanic "mk_avail" (ppr n)
730 | m `elemFM` acc = acc -- We import something already
731 | otherwise = addToFM acc m emptyAvailEnv
732 -- Add an empty collection of imports for a module
733 -- from which we have sucked only instance decls
735 direct_import_mods :: [ModuleName]
736 direct_import_mods = nub [m | ImportDecl m _ _ _ _ _ <- imports]
738 -- unused_imp_mods are the directly-imported modules
739 -- that are not mentioned in minimal_imports
740 unused_imp_mods = [m | m <- direct_import_mods,
741 not (maybeToBool (lookupFM minimal_imports m)),
744 module_unused :: Module -> Bool
745 module_unused mod = moduleName mod `elem` unused_imp_mods
747 warnDeprecations this_mod export_avails my_deprecs used_names
748 = doptRn Opt_WarnDeprecations `thenRn` \ warn_drs ->
749 if not warn_drs then returnRn () else
751 -- The home modules for things in the export list
752 -- may not have been loaded yet; do it now, so
753 -- that we can see their deprecations, if any
754 mapRn_ load_home export_mods `thenRn_`
756 getIfacesRn `thenRn` \ ifaces ->
757 getHomeIfaceTableRn `thenRn` \ hit ->
761 | n <- nameSetToList used_names,
762 Just txt <- [lookup_deprec hit pit n] ]
764 mapRn_ warnDeprec deprecs
767 export_mods = nub [ moduleName (nameModule name)
768 | avail <- export_avails,
769 let name = availName avail,
770 not (nameIsLocalOrFrom this_mod name) ]
772 load_home m = loadInterface (text "Check deprecations for" <+> ppr m) m ImportBySystem
774 lookup_deprec hit pit n
775 | nameIsLocalOrFrom this_mod n
776 = lookupDeprec my_deprecs n
778 = case lookupIface hit pit n of
779 Just iface -> lookupDeprec (mi_deprecs iface) n
780 Nothing -> pprPanic "warnDeprecations:" (ppr n)
782 -- ToDo: deal with original imports with 'qualified' and 'as M' clauses
783 printMinimalImports this_mod unqual imps
784 = doptRn Opt_D_dump_minimal_imports `thenRn` \ dump_minimal ->
785 if not dump_minimal then returnRn () else
787 mapRn to_ies (fmToList imps) `thenRn` \ mod_ies ->
788 ioToRnM (do { h <- openFile filename WriteMode ;
789 printForUser h unqual (vcat (map ppr_mod_ie mod_ies))
793 filename = moduleNameUserString (moduleName this_mod) ++ ".imports"
794 ppr_mod_ie (mod_name, ies)
795 | mod_name == pRELUDE_Name
798 = ptext SLIT("import") <+> ppr mod_name <>
799 parens (fsep (punctuate comma (map ppr ies)))
801 to_ies (mod, avail_env) = mapRn to_ie (availEnvElts avail_env) `thenRn` \ ies ->
804 to_ie :: AvailInfo -> RnMG (IE Name)
805 to_ie (Avail n) = returnRn (IEVar n)
806 to_ie (AvailTC n [m]) = ASSERT( n==m )
807 returnRn (IEThingAbs n)
809 = getInterfaceExports n_mod ImportBySystem `thenRn` \ (_, avails_by_module) ->
810 case [xs | (m,as) <- avails_by_module,
814 [xs] | all (`elem` ns) xs -> returnRn (IEThingAll n)
815 | otherwise -> returnRn (IEThingWith n (filter (/= n) ns))
816 other -> pprTrace "to_ie" (ppr n <+> ppr (nameModule n) <+> ppr other) $
819 n_mod = moduleName (nameModule n)
821 rnDump :: [RenamedHsDecl] -- Renamed imported decls
822 -> [RenamedHsDecl] -- Renamed local decls
824 rnDump imp_decls local_decls
825 = doptRn Opt_D_dump_rn_trace `thenRn` \ dump_rn_trace ->
826 doptRn Opt_D_dump_rn_stats `thenRn` \ dump_rn_stats ->
827 doptRn Opt_D_dump_rn `thenRn` \ dump_rn ->
828 getIfacesRn `thenRn` \ ifaces ->
830 ioToRnM (do { dumpIfSet (dump_rn_trace || dump_rn_stats || dump_rn)
832 (getRnStats imp_decls ifaces) ;
834 dumpIfSet dump_rn "Renamer:"
835 (vcat (map ppr (local_decls ++ imp_decls)))
842 %*********************************************************
844 \subsection{Statistics}
846 %*********************************************************
849 getRnStats :: [RenamedHsDecl] -> Ifaces -> SDoc
850 getRnStats imported_decls ifaces
851 = hcat [text "Renamer stats: ", stats]
853 n_mods = length [() | _ <- moduleEnvElts (iPIT ifaces)]
854 -- This is really only right for a one-shot compile
856 (decls_map, n_decls_slurped) = iDecls ifaces
858 n_decls_left = length [decl | (avail, True, (_,decl)) <- nameEnvElts decls_map
859 -- Data, newtype, and class decls are in the decls_fm
860 -- under multiple names; the tycon/class, and each
861 -- constructor/class op too.
862 -- The 'True' selects just the 'main' decl
865 (insts_left, n_insts_slurped) = iInsts ifaces
866 n_insts_left = length (bagToList insts_left)
868 (rules_left, n_rules_slurped) = iRules ifaces
869 n_rules_left = length (bagToList rules_left)
872 [int n_mods <+> text "interfaces read",
873 hsep [ int n_decls_slurped, text "type/class/variable imported, out of",
874 int (n_decls_slurped + n_decls_left), text "read"],
875 hsep [ int n_insts_slurped, text "instance decls imported, out of",
876 int (n_insts_slurped + n_insts_left), text "read"],
877 hsep [ int n_rules_slurped, text "rule decls imported, out of",
878 int (n_rules_slurped + n_rules_left), text "read"]
883 %************************************************************************
885 \subsection{Errors and warnings}
887 %************************************************************************
890 warnDeprec :: (Name, DeprecTxt) -> RnM d ()
891 warnDeprec (name, txt)
892 = pushSrcLocRn (getSrcLoc name) $
894 sep [ text (occNameFlavour (nameOccName name)) <+> ppr name <+>
895 text "is deprecated:", nest 4 (ppr txt) ]
898 dupFixityDecl rdr_name loc1 loc2
899 = vcat [ptext SLIT("Multiple fixity declarations for") <+> quotes (ppr rdr_name),
900 ptext SLIT("at ") <+> ppr loc1,
901 ptext SLIT("and") <+> ppr loc2]
904 = sep [ptext SLIT("Illegal deprecation when whole module is deprecated"),
908 = hsep [ptext SLIT("Module"), quotes (ppr mAIN_Name),
909 ptext SLIT("must include a definition for"), quotes (ptext SLIT("main"))]