2 % (c) The GRASP Project, Glasgow University, 1992-1998
4 \section[Rename]{Renaming and dependency analysis passes}
8 renameModule, renameStmt, renameRdrName,
9 closeIfaceDecls, checkOldIface
12 #include "HsVersions.h"
15 import RdrHsSyn ( RdrNameHsModule, RdrNameHsDecl, RdrNameDeprecation,
16 RdrNameTyClDecl, RdrNameRuleDecl, RdrNameInstDecl, RdrNameImportDecl,
19 import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl, RenamedRuleDecl, RenamedInstDecl,
21 instDeclFVs, tyClDeclFVs, ruleDeclFVs
24 import CmdLineOpts ( DynFlags, DynFlag(..) )
26 import RnExpr ( rnStmt )
27 import RnNames ( getGlobalNames, exportsFromAvail )
28 import RnSource ( rnSourceDecls, rnTyClDecl, rnIfaceRuleDecl, rnInstDecl )
29 import RnIfaces ( slurpImpDecls, mkImportInfo, recordLocalSlurps,
31 RecompileRequired, outOfDate, recompileRequired
33 import RnHiFiles ( readIface, loadInterface,
34 loadExports, loadFixDecls, loadDeprecs,
36 import RnEnv ( availsToNameSet, mkIfaceGlobalRdrEnv,
37 emptyAvailEnv, unitAvailEnv, availEnvElts,
38 plusAvailEnv, groupAvails, warnUnusedImports,
39 warnUnusedLocalBinds, warnUnusedModules,
40 lookupSrcName, getImplicitStmtFVs,
41 getImplicitModuleFVs, newGlobalName, unQualInScope,
42 ubiquitousNames, lookupOccRn
44 import Module ( Module, ModuleName, WhereFrom(..),
45 moduleNameUserString, moduleName,
48 import Name ( Name, nameModule )
51 import RdrName ( foldRdrEnv, isQual )
52 import PrelNames ( pRELUDE_Name )
53 import ErrUtils ( dumpIfSet, dumpIfSet_dyn, showPass,
54 printErrorsAndWarnings, errorsFound )
55 import Bag ( bagToList )
56 import FiniteMap ( FiniteMap, fmToList, emptyFM, lookupFM,
57 addToFM_C, elemFM, addToFM
59 import Maybes ( maybeToBool, catMaybes )
61 import IO ( openFile, IOMode(..) )
62 import HscTypes -- lots of it
63 import List ( partition, nub )
69 %*********************************************************
71 \subsection{The main wrappers}
73 %*********************************************************
76 renameModule :: DynFlags
77 -> HomeIfaceTable -> HomeSymbolTable
78 -> PersistentCompilerState
79 -> Module -> RdrNameHsModule
80 -> IO (PersistentCompilerState, PrintUnqualified,
81 Maybe (IsExported, ModIface, [RenamedHsDecl]))
82 -- Nothing => some error occurred in the renamer
84 renameModule dflags hit hst pcs this_module rdr_module
85 = renameSource dflags hit hst pcs this_module $
86 rename this_module rdr_module
90 renameStmt :: DynFlags
91 -> HomeIfaceTable -> HomeSymbolTable
92 -> PersistentCompilerState
93 -> Module -- current module
95 -> RdrNameStmt -- parsed stmt
96 -> IO ( PersistentCompilerState,
98 Maybe ([Name], (RenamedStmt, [RenamedHsDecl]))
101 renameStmt dflags hit hst pcs this_module ic stmt
102 = renameSource dflags hit hst pcs this_module $
103 extendTypeEnvRn (ic_type_env ic) $
105 -- load the context module
106 loadContextModule (ic_module ic) $ \ (rdr_env, print_unqual) ->
109 initRnMS rdr_env (ic_rn_env ic) emptyLocalFixityEnv CmdLineMode (
110 rnStmt stmt $ \ stmt' ->
111 returnRn (([], stmt'), emptyFVs)
112 ) `thenRn` \ ((binders, stmt), fvs) ->
114 -- Bale out if we fail
115 checkErrsRn `thenRn` \ no_errs_so_far ->
116 if not no_errs_so_far then
117 doDump dflags [] stmt [] `thenRn_` returnRn (print_unqual, Nothing)
120 -- Add implicit free vars, and close decls
121 getImplicitStmtFVs `thenRn` \ implicit_fvs ->
122 slurpImpDecls (fvs `plusFV` implicit_fvs) `thenRn` \ decls ->
123 -- NB: an earlier version deleted (rdrEnvElts local_env) from
124 -- the fvs. But (a) that isn't necessary, because previously
125 -- bound things in the local_env will be in the TypeEnv, and
126 -- the renamer doesn't re-slurp such things, and
127 -- (b) it's WRONG to delete them. Consider in GHCi:
128 -- Mod> let x = e :: T
129 -- Mod> let y = x + 3
130 -- We need to pass 'x' among the fvs to slurpImpDecls, so that
131 -- the latter can see that T is a gate, and hence import the Num T
132 -- instance decl. (See the InTypEnv case in RnIfaces.slurpSourceRefs.)
134 doDump dflags binders stmt decls `thenRn_`
135 returnRn (print_unqual, Just (binders, (stmt, decls)))
138 doDump :: DynFlags -> [Name] -> RenamedStmt -> [RenamedHsDecl]
139 -> RnMG (Either IOError ())
140 doDump dflags bndrs stmt decls
141 = ioToRnM (dumpIfSet_dyn dflags Opt_D_dump_rn "Renamer:"
142 (vcat [text "Binders:" <+> ppr bndrs,
144 vcat (map ppr decls)]))
149 -> HomeIfaceTable -> HomeSymbolTable
150 -> PersistentCompilerState
151 -> Module -- current module
152 -> InteractiveContext
153 -> [RdrName] -- name to rename
154 -> IO ( PersistentCompilerState,
156 Maybe ([Name], [RenamedHsDecl])
159 renameRdrName dflags hit hst pcs this_module ic rdr_names =
160 renameSource dflags hit hst pcs this_module $
161 extendTypeEnvRn (ic_type_env ic) $
162 loadContextModule (ic_module ic) $ \ (rdr_env, print_unqual) ->
164 -- rename the rdr_name
165 initRnMS rdr_env (ic_rn_env ic) emptyLocalFixityEnv CmdLineMode
166 (mapRn (tryRn.lookupOccRn) rdr_names) `thenRn` \ maybe_names ->
168 ok_names = [ a | Right a <- maybe_names ]
171 then let errs = head [ e | Left e <- maybe_names ]
172 in setErrsRn errs `thenRn_`
173 doDump dflags ok_names [] `thenRn_`
174 returnRn (print_unqual, Nothing)
177 slurpImpDecls (mkNameSet ok_names) `thenRn` \ decls ->
179 doDump dflags ok_names decls `thenRn_`
180 returnRn (print_unqual, Just (ok_names, decls))
182 doDump :: DynFlags -> [Name] -> [RenamedHsDecl] -> RnMG (Either IOError ())
183 doDump dflags names decls
184 = ioToRnM (dumpIfSet_dyn dflags Opt_D_dump_rn "Renamer:"
185 (vcat [ppr names, text "",
186 vcat (map ppr decls)]))
189 -- Load the interface for the context module, so
190 -- that we can get its top-level lexical environment
191 -- Bale out if we fail to do this
192 loadContextModule scope_module thing_inside
193 = let doc = text "context for compiling expression"
195 loadInterface doc (moduleName scope_module) ImportByUser `thenRn` \ iface ->
196 let rdr_env = mi_globals iface
197 print_unqual = unQualInScope rdr_env
199 checkErrsRn `thenRn` \ no_errs_so_far ->
200 if not no_errs_so_far then
201 returnRn (print_unqual, Nothing)
203 thing_inside (rdr_env, print_unqual)
206 %*********************************************************
208 \subsection{The main function: rename}
210 %*********************************************************
213 renameSource :: DynFlags
214 -> HomeIfaceTable -> HomeSymbolTable
215 -> PersistentCompilerState
217 -> RnMG (PrintUnqualified, Maybe r)
218 -> IO (PersistentCompilerState, PrintUnqualified, Maybe r)
219 -- Nothing => some error occurred in the renamer
221 renameSource dflags hit hst old_pcs this_module thing_inside
222 = do { showPass dflags "Renamer"
224 -- Initialise the renamer monad
225 ; (new_pcs, msgs, (print_unqual, maybe_rn_stuff))
226 <- initRn dflags hit hst old_pcs this_module thing_inside
228 -- Print errors from renaming
229 ; printErrorsAndWarnings print_unqual msgs ;
231 -- Return results. No harm in updating the PCS
232 ; if errorsFound msgs then
233 return (new_pcs, print_unqual, Nothing)
235 return (new_pcs, print_unqual, maybe_rn_stuff)
240 rename :: Module -> RdrNameHsModule
241 -> RnMG (PrintUnqualified, Maybe (IsExported, ModIface, [RenamedHsDecl]))
242 rename this_module contents@(HsModule _ _ exports imports local_decls mod_deprec loc)
245 -- FIND THE GLOBAL NAME ENVIRONMENT
246 getGlobalNames this_module contents `thenRn` \ (gbl_env, local_gbl_env, all_avails@(_, global_avail_env)) ->
248 print_unqualified = unQualInScope gbl_env
250 -- Exit if we've found any errors
251 checkErrsRn `thenRn` \ no_errs_so_far ->
252 if not no_errs_so_far then
253 -- Found errors already, so exit now
254 rnDump [] [] `thenRn_`
255 returnRn (print_unqualified, Nothing)
258 -- PROCESS EXPORT LIST
259 exportsFromAvail mod_name exports all_avails gbl_env `thenRn` \ export_avails ->
261 traceRn (text "Local top-level environment" $$
262 nest 4 (pprGlobalRdrEnv local_gbl_env)) `thenRn_`
264 -- DEAL WITH DEPRECATIONS
265 rnDeprecs local_gbl_env mod_deprec
266 [d | DeprecD d <- local_decls] `thenRn` \ my_deprecs ->
268 -- DEAL WITH LOCAL FIXITIES
269 fixitiesFromLocalDecls local_gbl_env local_decls `thenRn` \ local_fixity_env ->
272 rnSourceDecls gbl_env local_fixity_env local_decls `thenRn` \ (rn_local_decls, source_fvs) ->
274 -- EXIT IF ERRORS FOUND
275 -- We exit here if there are any errors in the source, *before*
276 -- we attempt to slurp the decls from the interfaces, otherwise
277 -- the slurped decls may get lost when we return up the stack
278 -- to hscMain/hscExpr.
279 checkErrsRn `thenRn` \ no_errs_so_far ->
280 if not no_errs_so_far then
281 -- Found errors already, so exit now
282 rnDump [] rn_local_decls `thenRn_`
283 returnRn (print_unqualified, Nothing)
286 -- SLURP IN ALL THE NEEDED DECLARATIONS
287 -- Find out what re-bindable names to use for desugaring
288 getImplicitModuleFVs mod_name rn_local_decls `thenRn` \ implicit_fvs ->
290 export_fvs = availsToNameSet export_avails
291 source_fvs2 = source_fvs `plusFV` export_fvs
292 -- The export_fvs make the exported names look just as if they
293 -- occurred in the source program. For the reasoning, see the
294 -- comments with RnIfaces.mkImportInfo
295 -- It also helps reportUnusedNames, which of course must not complain
296 -- that 'f' isn't mentioned if it is mentioned in the export list
298 source_fvs3 = implicit_fvs `plusFV` source_fvs2
299 -- It's important to do the "plus" this way round, so that
300 -- when compiling the prelude, locally-defined (), Bool, etc
301 -- override the implicit ones.
304 traceRn (text "Source FVs:" <+> fsep (map ppr (nameSetToList source_fvs3))) `thenRn_`
305 slurpImpDecls source_fvs3 `thenRn` \ rn_imp_decls ->
306 rnDump rn_imp_decls rn_local_decls `thenRn_`
308 -- GENERATE THE VERSION/USAGE INFO
309 mkImportInfo mod_name imports `thenRn` \ my_usages ->
311 -- BUILD THE MODULE INTERFACE
313 -- We record fixities even for things that aren't exported,
314 -- so that we can change into the context of this moodule easily
315 fixities = mkNameEnv [ (name, fixity)
316 | FixitySig name fixity loc <- nameEnvElts local_fixity_env
319 -- Sort the exports to make them easier to compare for versions
320 my_exports = groupAvails this_module export_avails
322 final_decls = rn_local_decls ++ rn_imp_decls
324 mod_iface = ModIface { mi_module = this_module,
325 mi_version = initialVersionInfo,
326 mi_usages = my_usages,
328 mi_orphan = panic "is_orphan",
329 mi_exports = my_exports,
330 mi_globals = gbl_env,
331 mi_fixities = fixities,
332 mi_deprecs = my_deprecs,
333 mi_decls = panic "mi_decls"
336 is_exported name = name `elemNameSet` exported_names
337 exported_names = availsToNameSet export_avails
340 -- REPORT UNUSED NAMES, AND DEBUG DUMP
341 reportUnusedNames mod_iface print_unqualified
342 imports global_avail_env
343 source_fvs2 rn_imp_decls `thenRn_`
344 -- NB: source_fvs2: include exports (else we get bogus
345 -- warnings of unused things) but not implicit FVs.
347 returnRn (print_unqualified, Just (is_exported, mod_iface, final_decls))
349 mod_name = moduleName this_module
354 %*********************************************************
356 \subsection{Fixities}
358 %*********************************************************
361 fixitiesFromLocalDecls :: GlobalRdrEnv -> [RdrNameHsDecl] -> RnMG LocalFixityEnv
362 fixitiesFromLocalDecls gbl_env decls
363 = foldlRn getFixities emptyNameEnv decls `thenRn` \ env ->
364 traceRn (text "fixity env" <+> vcat (map ppr (nameEnvElts env))) `thenRn_`
367 getFixities :: LocalFixityEnv -> RdrNameHsDecl -> RnMG LocalFixityEnv
368 getFixities acc (FixD fix)
371 getFixities acc (TyClD (ClassDecl { tcdSigs = sigs}))
372 = foldlRn fix_decl acc [sig | FixSig sig <- sigs]
373 -- Get fixities from class decl sigs too.
374 getFixities acc other_decl
377 fix_decl acc sig@(FixitySig rdr_name fixity loc)
378 = -- Check for fixity decl for something not declared
380 lookupSrcName gbl_env rdr_name `thenRn` \ name ->
382 -- Check for duplicate fixity decl
383 case lookupNameEnv acc name of
384 Just (FixitySig _ _ loc') -> addErrRn (dupFixityDecl rdr_name loc loc') `thenRn_`
387 Nothing -> returnRn (extendNameEnv acc name (FixitySig name fixity loc))
391 %*********************************************************
393 \subsection{Deprecations}
395 %*********************************************************
397 For deprecations, all we do is check that the names are in scope.
398 It's only imported deprecations, dealt with in RnIfaces, that we
399 gather them together.
402 rnDeprecs :: GlobalRdrEnv -> Maybe DeprecTxt
403 -> [RdrNameDeprecation] -> RnMG Deprecations
404 rnDeprecs gbl_env Nothing []
407 rnDeprecs gbl_env (Just txt) decls
408 = mapRn (addErrRn . badDeprec) decls `thenRn_`
409 returnRn (DeprecAll txt)
411 rnDeprecs gbl_env Nothing decls
412 = mapRn rn_deprec decls `thenRn` \ pairs ->
413 returnRn (DeprecSome (mkNameEnv (catMaybes pairs)))
415 rn_deprec (Deprecation rdr_name txt loc)
417 lookupSrcName gbl_env rdr_name `thenRn` \ name ->
418 returnRn (Just (name, (name,txt)))
422 %************************************************************************
424 \subsection{Grabbing the old interface file and checking versions}
426 %************************************************************************
429 checkOldIface :: GhciMode
431 -> HomeIfaceTable -> HomeSymbolTable
432 -> PersistentCompilerState
434 -> Bool -- Source unchanged
435 -> Maybe ModIface -- Old interface from compilation manager, if any
436 -> IO (PersistentCompilerState, Bool, (RecompileRequired, Maybe ModIface))
437 -- True <=> errors happened
439 checkOldIface ghci_mode dflags hit hst pcs iface_path source_unchanged maybe_iface
440 = runRn dflags hit hst pcs (panic "Bogus module") $
442 -- CHECK WHETHER THE SOURCE HAS CHANGED
443 ( if not source_unchanged then
444 traceHiDiffsRn (nest 4 (text "Source file changed or recompilation check turned off"))
445 else returnRn () ) `thenRn_`
447 -- If the source has changed and we're in interactive mode, avoid reading
448 -- an interface; just return the one we might have been supplied with.
449 if ghci_mode == Interactive && not source_unchanged then
450 returnRn (outOfDate, maybe_iface)
454 Just old_iface -> -- Use the one we already have
455 setModuleRn (mi_module old_iface) (check_versions old_iface)
457 Nothing -- try and read it from a file
458 -> readIface iface_path `thenRn` \ read_result ->
460 Left err -> -- Old interface file not found, or garbled; give up
462 text "Cannot read old interface file:"
463 $$ nest 4 err) `thenRn_`
464 returnRn (outOfDate, Nothing)
467 -> setModuleRn (pi_mod parsed_iface) $
468 loadOldIface parsed_iface `thenRn` \ m_iface ->
469 check_versions m_iface
471 check_versions :: ModIface -> RnMG (RecompileRequired, Maybe ModIface)
473 | not source_unchanged
474 = returnRn (outOfDate, Just iface)
477 recompileRequired iface_path iface `thenRn` \ recompile ->
478 returnRn (recompile, Just iface)
481 I think the following function should now have a more representative name,
485 loadOldIface :: ParsedIface -> RnMG ModIface
487 loadOldIface parsed_iface
488 = let iface = parsed_iface
492 loadHomeDecls (pi_decls iface) `thenRn` \ decls ->
493 loadHomeRules (pi_rules iface) `thenRn` \ rules ->
494 loadHomeInsts (pi_insts iface) `thenRn` \ insts ->
495 returnRn (decls, rules, insts)
497 `thenRn` \ ((decls_vers, new_decls), (rule_vers, new_rules), new_insts) ->
499 mapRn loadHomeUsage (pi_usages iface) `thenRn` \ usages ->
500 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
501 loadFixDecls mod (pi_fixity iface) `thenRn` \ fix_env ->
502 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
504 version = VersionInfo { vers_module = pi_vers iface,
505 vers_exports = export_vers,
506 vers_rules = rule_vers,
507 vers_decls = decls_vers }
509 decls = mkIfaceDecls new_decls new_rules new_insts
511 mod_iface = ModIface { mi_module = mod, mi_version = version,
512 mi_exports = avails, mi_usages = usages,
513 mi_boot = False, mi_orphan = pi_orphan iface,
514 mi_fixities = fix_env, mi_deprecs = deprec_env,
516 mi_globals = mkIfaceGlobalRdrEnv avails
523 loadHomeDecls :: [(Version, RdrNameTyClDecl)]
524 -> RnMS (NameEnv Version, [RenamedTyClDecl])
525 loadHomeDecls decls = foldlRn loadHomeDecl (emptyNameEnv, []) decls
527 loadHomeDecl :: (NameEnv Version, [RenamedTyClDecl])
528 -> (Version, RdrNameTyClDecl)
529 -> RnMS (NameEnv Version, [RenamedTyClDecl])
530 loadHomeDecl (version_map, decls) (version, decl)
531 = rnTyClDecl decl `thenRn` \ decl' ->
532 returnRn (extendNameEnv version_map (tyClDeclName decl') version, decl':decls)
535 loadHomeRules :: (Version, [RdrNameRuleDecl])
536 -> RnMS (Version, [RenamedRuleDecl])
537 loadHomeRules (version, rules)
538 = mapRn rnIfaceRuleDecl rules `thenRn` \ rules' ->
539 returnRn (version, rules')
542 loadHomeInsts :: [RdrNameInstDecl]
543 -> RnMS [RenamedInstDecl]
544 loadHomeInsts insts = mapRn rnInstDecl insts
547 loadHomeUsage :: ImportVersion OccName
548 -> RnMG (ImportVersion Name)
549 loadHomeUsage (mod_name, orphans, is_boot, whats_imported)
550 = rn_imps whats_imported `thenRn` \ whats_imported' ->
551 returnRn (mod_name, orphans, is_boot, whats_imported')
553 rn_imps NothingAtAll = returnRn NothingAtAll
554 rn_imps (Everything v) = returnRn (Everything v)
555 rn_imps (Specifically mv ev items rv) = mapRn rn_imp items `thenRn` \ items' ->
556 returnRn (Specifically mv ev items' rv)
557 rn_imp (occ,vers) = newGlobalName mod_name occ `thenRn` \ name ->
563 %*********************************************************
565 \subsection{Closing up the interface decls}
567 %*********************************************************
569 Suppose we discover we don't need to recompile. Then we start from the
570 IfaceDecls in the ModIface, and fluff them up by sucking in all the decls they need.
573 closeIfaceDecls :: DynFlags
574 -> HomeIfaceTable -> HomeSymbolTable
575 -> PersistentCompilerState
576 -> ModIface -- Get the decls from here
577 -> IO (PersistentCompilerState, Bool, [RenamedHsDecl])
578 -- True <=> errors happened
579 closeIfaceDecls dflags hit hst pcs
580 mod_iface@(ModIface { mi_module = mod, mi_decls = iface_decls })
581 = runRn dflags hit hst pcs mod $
584 rule_decls = dcl_rules iface_decls
585 inst_decls = dcl_insts iface_decls
586 tycl_decls = dcl_tycl iface_decls
587 decls = map RuleD rule_decls ++
588 map InstD inst_decls ++
590 needed = unionManyNameSets (map ruleDeclFVs rule_decls) `unionNameSets`
591 unionManyNameSets (map instDeclFVs inst_decls) `unionNameSets`
592 unionManyNameSets (map tyClDeclFVs tycl_decls)
593 local_names = foldl add emptyNameSet tycl_decls
594 add names decl = addListToNameSet names (map fst (tyClDeclSysNames decl ++ tyClDeclNames decl))
597 recordLocalSlurps local_names `thenRn_`
599 -- Do the transitive closure
600 closeDecls decls (needed `plusFV` implicit_fvs) `thenRn` \closed_decls ->
601 rnDump [] closed_decls `thenRn_`
602 returnRn closed_decls
604 implicit_fvs = ubiquitousNames -- Data type decls with record selectors,
605 -- which may appear in the decls, need unpackCString
606 -- and friends. It's easier to just grab them right now.
609 %*********************************************************
611 \subsection{Unused names}
613 %*********************************************************
616 reportUnusedNames :: ModIface -> PrintUnqualified
617 -> [RdrNameImportDecl]
619 -> NameSet -- Used in this module
622 reportUnusedNames my_mod_iface unqual imports avail_env
623 used_names imported_decls
624 = warnUnusedModules unused_imp_mods `thenRn_`
625 warnUnusedLocalBinds bad_locals `thenRn_`
626 warnUnusedImports bad_imp_names `thenRn_`
627 printMinimalImports this_mod unqual minimal_imports
629 this_mod = mi_module my_mod_iface
630 gbl_env = mi_globals my_mod_iface
632 -- Now, a use of C implies a use of T,
633 -- if C was brought into scope by T(..) or T(C)
634 really_used_names = used_names `unionNameSets`
635 mkNameSet [ parent_name
636 | sub_name <- nameSetToList used_names
638 -- Usually, every used name will appear in avail_env, but there
639 -- is one time when it doesn't: tuples and other built in syntax. When you
640 -- write (a,b) that gives rise to a *use* of "(,)", so that the
641 -- instances will get pulled in, but the tycon "(,)" isn't actually
642 -- in scope. Also, (-x) gives rise to an implicit use of 'negate';
643 -- similarly, 3.5 gives rise to an implcit use of :%
644 -- Hence the silent 'False' in all other cases
646 , Just parent_name <- [case lookupNameEnv avail_env sub_name of
647 Just (AvailTC n _) -> Just n
651 -- Collect the defined names from the in-scope environment
652 -- Look for the qualified ones only, else get duplicates
653 defined_names :: [GlobalRdrElt]
654 defined_names = foldRdrEnv add [] gbl_env
655 add rdr_name ns acc | isQual rdr_name = ns ++ acc
658 defined_and_used, defined_but_not_used :: [GlobalRdrElt]
659 (defined_and_used, defined_but_not_used) = partition used defined_names
660 used (GRE name _ _) = name `elemNameSet` really_used_names
662 -- Filter out the ones only defined implicitly
664 bad_locals = [n | (GRE n LocalDef _) <- defined_but_not_used]
666 bad_imp_names :: [(Name,Provenance)]
667 bad_imp_names = [(n,p) | GRE n p@(NonLocalDef (UserImport mod _ True)) _ <- defined_but_not_used,
668 not (module_unused mod)]
670 -- inst_mods are directly-imported modules that
671 -- contain instance decl(s) that the renamer decided to suck in
672 -- It's not necessarily redundant to import such modules.
678 -- The import M() is not *necessarily* redundant, even if
679 -- we suck in no instance decls from M (e.g. it contains
680 -- no instance decls, or This contains no code). It may be
681 -- that we import M solely to ensure that M's orphan instance
682 -- decls (or those in its imports) are visible to people who
683 -- import This. Sigh.
684 -- There's really no good way to detect this, so the error message
685 -- in RnEnv.warnUnusedModules is weakened instead
686 inst_mods :: [ModuleName]
687 inst_mods = [m | InstD (InstDecl _ _ _ (Just dfun) _) <- imported_decls,
688 let m = moduleName (nameModule dfun),
689 m `elem` direct_import_mods
692 -- To figure out the minimal set of imports, start with the things
693 -- that are in scope (i.e. in gbl_env). Then just combine them
694 -- into a bunch of avails, so they are properly grouped
695 minimal_imports :: FiniteMap ModuleName AvailEnv
696 minimal_imports0 = emptyFM
697 minimal_imports1 = foldr add_name minimal_imports0 defined_and_used
698 minimal_imports = foldr add_inst_mod minimal_imports1 inst_mods
700 -- We've carefully preserved the provenance so that we can
701 -- construct minimal imports that import the name by (one of)
702 -- the same route(s) as the programmer originally did.
703 add_name (GRE n (NonLocalDef (UserImport m _ _)) _) acc = addToFM_C plusAvailEnv acc (moduleName m)
704 (unitAvailEnv (mk_avail n))
705 add_name (GRE n other_prov _) acc = acc
707 mk_avail n = case lookupNameEnv avail_env n of
708 Just (AvailTC m _) | n==m -> AvailTC n [n]
709 | otherwise -> AvailTC m [n,m]
710 Just avail -> Avail n
711 Nothing -> pprPanic "mk_avail" (ppr n)
714 | m `elemFM` acc = acc -- We import something already
715 | otherwise = addToFM acc m emptyAvailEnv
716 -- Add an empty collection of imports for a module
717 -- from which we have sucked only instance decls
719 direct_import_mods :: [ModuleName]
720 direct_import_mods = nub [m | ImportDecl m _ _ _ _ _ <- imports]
722 -- unused_imp_mods are the directly-imported modules
723 -- that are not mentioned in minimal_imports
724 unused_imp_mods = [m | m <- direct_import_mods,
725 not (maybeToBool (lookupFM minimal_imports m)),
728 module_unused :: Module -> Bool
729 module_unused mod = moduleName mod `elem` unused_imp_mods
732 -- ToDo: deal with original imports with 'qualified' and 'as M' clauses
733 printMinimalImports :: Module -- This module
735 -> FiniteMap ModuleName AvailEnv -- Minimal imports
737 printMinimalImports this_mod unqual imps
738 = ifOptRn Opt_D_dump_minimal_imports $
740 mapRn to_ies (fmToList imps) `thenRn` \ mod_ies ->
741 ioToRnM (do { h <- openFile filename WriteMode ;
742 printForUser h unqual (vcat (map ppr_mod_ie mod_ies))
746 filename = moduleNameUserString (moduleName this_mod) ++ ".imports"
747 ppr_mod_ie (mod_name, ies)
748 | mod_name == pRELUDE_Name
751 = ptext SLIT("import") <+> ppr mod_name <>
752 parens (fsep (punctuate comma (map ppr ies)))
754 to_ies (mod, avail_env) = mapRn to_ie (availEnvElts avail_env) `thenRn` \ ies ->
757 to_ie :: AvailInfo -> RnMG (IE Name)
758 -- The main trick here is that if we're importing all the constructors
759 -- we want to say "T(..)", but if we're importing only a subset we want
760 -- to say "T(A,B,C)". So we have to find out what the module exports.
761 to_ie (Avail n) = returnRn (IEVar n)
762 to_ie (AvailTC n [m]) = ASSERT( n==m )
763 returnRn (IEThingAbs n)
765 = loadInterface (text "Compute minimal imports from" <+> ppr n_mod) n_mod ImportBySystem `thenRn` \ iface ->
766 case [xs | (m,as) <- mi_exports iface,
770 [xs] | all (`elem` ns) xs -> returnRn (IEThingAll n)
771 | otherwise -> returnRn (IEThingWith n (filter (/= n) ns))
772 other -> pprTrace "to_ie" (ppr n <+> ppr (nameModule n) <+> ppr other) $
775 n_mod = moduleName (nameModule n)
777 rnDump :: [RenamedHsDecl] -- Renamed imported decls
778 -> [RenamedHsDecl] -- Renamed local decls
780 rnDump imp_decls local_decls
781 = doptRn Opt_D_dump_rn_trace `thenRn` \ dump_rn_trace ->
782 doptRn Opt_D_dump_rn_stats `thenRn` \ dump_rn_stats ->
783 doptRn Opt_D_dump_rn `thenRn` \ dump_rn ->
784 getIfacesRn `thenRn` \ ifaces ->
786 ioToRnM (do { dumpIfSet (dump_rn_trace || dump_rn_stats || dump_rn)
788 (getRnStats imp_decls ifaces) ;
790 dumpIfSet dump_rn "Renamer:"
791 (vcat (map ppr (local_decls ++ imp_decls)))
798 %*********************************************************
800 \subsection{Statistics}
802 %*********************************************************
805 getRnStats :: [RenamedHsDecl] -> Ifaces -> SDoc
806 getRnStats imported_decls ifaces
807 = hcat [text "Renamer stats: ", stats]
809 n_mods = length [() | _ <- moduleEnvElts (iPIT ifaces)]
810 -- This is really only right for a one-shot compile
812 (decls_map, n_decls_slurped) = iDecls ifaces
814 n_decls_left = length [decl | (avail, True, (_,decl)) <- nameEnvElts decls_map
815 -- Data, newtype, and class decls are in the decls_fm
816 -- under multiple names; the tycon/class, and each
817 -- constructor/class op too.
818 -- The 'True' selects just the 'main' decl
821 (insts_left, n_insts_slurped) = iInsts ifaces
822 n_insts_left = length (bagToList insts_left)
824 (rules_left, n_rules_slurped) = iRules ifaces
825 n_rules_left = length (bagToList rules_left)
828 [int n_mods <+> text "interfaces read",
829 hsep [ int n_decls_slurped, text "type/class/variable imported, out of",
830 int (n_decls_slurped + n_decls_left), text "read"],
831 hsep [ int n_insts_slurped, text "instance decls imported, out of",
832 int (n_insts_slurped + n_insts_left), text "read"],
833 hsep [ int n_rules_slurped, text "rule decls imported, out of",
834 int (n_rules_slurped + n_rules_left), text "read"]
839 %************************************************************************
841 \subsection{Errors and warnings}
843 %************************************************************************
846 dupFixityDecl rdr_name loc1 loc2
847 = vcat [ptext SLIT("Multiple fixity declarations for") <+> quotes (ppr rdr_name),
848 ptext SLIT("at ") <+> ppr loc1,
849 ptext SLIT("and") <+> ppr loc2]
852 = sep [ptext SLIT("Illegal deprecation when whole module is deprecated"),