2 % (c) The GRASP Project, Glasgow University, 1992-1998
4 \section[Rename]{Renaming and dependency analysis passes}
7 module Rename ( renameModule, renameStmt, closeIfaceDecls, checkOldIface ) where
9 #include "HsVersions.h"
12 import RdrHsSyn ( RdrNameHsModule, RdrNameHsDecl, RdrNameDeprecation,
13 RdrNameTyClDecl, RdrNameRuleDecl, RdrNameInstDecl, RdrNameImportDecl,
16 import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl, RenamedRuleDecl, RenamedInstDecl,
18 instDeclFVs, tyClDeclFVs, ruleDeclFVs
21 import CmdLineOpts ( DynFlags, DynFlag(..) )
23 import RnExpr ( rnStmt )
24 import RnNames ( getGlobalNames, exportsFromAvail )
25 import RnSource ( rnSourceDecls, rnTyClDecl, rnIfaceRuleDecl, rnInstDecl )
26 import RnIfaces ( slurpImpDecls, mkImportInfo, recordLocalSlurps,
28 RecompileRequired, outOfDate, recompileRequired
30 import RnHiFiles ( readIface, loadInterface,
31 loadExports, loadFixDecls, loadDeprecs,
33 import RnEnv ( availsToNameSet, mkIfaceGlobalRdrEnv,
34 emptyAvailEnv, unitAvailEnv, availEnvElts,
35 plusAvailEnv, groupAvails, warnUnusedImports,
36 warnUnusedLocalBinds, warnUnusedModules,
37 lookupSrcName, getImplicitStmtFVs, getImplicitModuleFVs,
38 newGlobalName, unQualInScope,, ubiquitousNames
40 import Module ( Module, ModuleName, WhereFrom(..),
41 moduleNameUserString, moduleName,
44 import Name ( Name, nameModule )
47 import RdrName ( foldRdrEnv, isQual )
48 import PrelNames ( pRELUDE_Name )
49 import ErrUtils ( dumpIfSet, dumpIfSet_dyn, showPass,
50 printErrorsAndWarnings, errorsFound )
51 import Bag ( bagToList )
52 import FiniteMap ( FiniteMap, fmToList, emptyFM, lookupFM,
53 addToFM_C, elemFM, addToFM
55 import Maybes ( maybeToBool, catMaybes )
57 import IO ( openFile, IOMode(..) )
58 import HscTypes ( PersistentCompilerState, HomeIfaceTable, HomeSymbolTable,
59 ModIface(..), WhatsImported(..),
60 VersionInfo(..), ImportVersion, IsExported,
61 IfaceDecls, mkIfaceDecls, dcl_tycl, dcl_rules, dcl_insts,
62 GlobalRdrEnv, GlobalRdrElt(..), pprGlobalRdrEnv,
63 AvailEnv, GenAvailInfo(..), AvailInfo,
64 Provenance(..), ImportReason(..), initialVersionInfo,
65 Deprecations(..), GhciMode(..),
68 import List ( partition, nub )
74 %*********************************************************
76 \subsection{The two main wrappers}
78 %*********************************************************
81 renameModule :: DynFlags
82 -> HomeIfaceTable -> HomeSymbolTable
83 -> PersistentCompilerState
84 -> Module -> RdrNameHsModule
85 -> IO (PersistentCompilerState, PrintUnqualified,
86 Maybe (IsExported, ModIface, [RenamedHsDecl]))
87 -- Nothing => some error occurred in the renamer
89 renameModule dflags hit hst pcs this_module rdr_module
90 = renameSource dflags hit hst pcs this_module $
91 rename this_module rdr_module
96 renameStmt :: DynFlags
97 -> HomeIfaceTable -> HomeSymbolTable
98 -> PersistentCompilerState
99 -> Module -- current context (scope to compile in)
100 -> Module -- current module
101 -> LocalRdrEnv -- current context (temp bindings)
102 -> RdrNameStmt -- parsed stmt
103 -> IO ( PersistentCompilerState,
105 Maybe ([Name], (RenamedStmt, [RenamedHsDecl]))
108 renameStmt dflags hit hst pcs scope_module this_module local_env stmt
109 = renameSource dflags hit hst pcs this_module $
111 -- Load the interface for the context module, so
112 -- that we can get its top-level lexical environment
113 -- Bale out if we fail to do this
114 loadInterface doc (moduleName scope_module) ImportByUser `thenRn` \ iface ->
115 let rdr_env = mi_globals iface
116 print_unqual = unQualInScope rdr_env
118 checkErrsRn `thenRn` \ no_errs_so_far ->
119 if not no_errs_so_far then
120 returnRn (print_unqual, Nothing)
124 initRnMS rdr_env local_env emptyLocalFixityEnv CmdLineMode (
125 rnStmt stmt $ \ stmt' ->
126 returnRn (([], stmt'), emptyFVs)
127 ) `thenRn` \ ((binders, stmt), fvs) ->
129 -- Bale out if we fail
130 checkErrsRn `thenRn` \ no_errs_so_far ->
131 if not no_errs_so_far then
132 doDump [] stmt [] `thenRn_` returnRn (print_unqual, Nothing)
135 -- Add implicit free vars, and close decls
136 getImplicitStmtFVs `thenRn` \ implicit_fvs ->
138 filtered_fvs = fvs `delListFromNameSet` rdrEnvElts local_env
139 source_fvs = implicit_fvs `plusFV` filtered_fvs
141 slurpImpDecls source_fvs `thenRn` \ decls ->
143 doDump binders stmt decls `thenRn_`
144 returnRn (print_unqual, Just (binders, (stmt, decls)))
147 doc = text "context for compiling expression"
149 doDump :: [Name] -> RenamedStmt -> [RenamedHsDecl] -> RnMG (Either IOError ())
150 doDump bndrs stmt decls
151 = getDOptsRn `thenRn` \ dflags ->
152 ioToRnM (dumpIfSet_dyn dflags Opt_D_dump_rn "Renamer:"
153 (vcat [text "Binders:" <+> ppr bndrs,
155 vcat (map ppr decls)]))
159 %*********************************************************
161 \subsection{The main function: rename}
163 %*********************************************************
166 renameSource :: DynFlags
167 -> HomeIfaceTable -> HomeSymbolTable
168 -> PersistentCompilerState
170 -> RnMG (PrintUnqualified, Maybe r)
171 -> IO (PersistentCompilerState, PrintUnqualified, Maybe r)
172 -- Nothing => some error occurred in the renamer
174 renameSource dflags hit hst old_pcs this_module thing_inside
175 = do { showPass dflags "Renamer"
177 -- Initialise the renamer monad
178 ; (new_pcs, msgs, (print_unqual, maybe_rn_stuff))
179 <- initRn dflags hit hst old_pcs this_module thing_inside
181 -- Print errors from renaming
182 ; printErrorsAndWarnings print_unqual msgs ;
184 -- Return results. No harm in updating the PCS
185 ; if errorsFound msgs then
186 return (new_pcs, print_unqual, Nothing)
188 return (new_pcs, print_unqual, maybe_rn_stuff)
193 rename :: Module -> RdrNameHsModule
194 -> RnMG (PrintUnqualified, Maybe (IsExported, ModIface, [RenamedHsDecl]))
195 rename this_module contents@(HsModule _ _ exports imports local_decls mod_deprec loc)
198 -- FIND THE GLOBAL NAME ENVIRONMENT
199 getGlobalNames this_module contents `thenRn` \ (gbl_env, local_gbl_env, all_avails@(_, global_avail_env)) ->
201 print_unqualified = unQualInScope gbl_env
203 -- Exit if we've found any errors
204 checkErrsRn `thenRn` \ no_errs_so_far ->
205 if not no_errs_so_far then
206 -- Found errors already, so exit now
207 rnDump [] [] `thenRn_`
208 returnRn (print_unqualified, Nothing)
211 -- PROCESS EXPORT LIST
212 exportsFromAvail mod_name exports all_avails gbl_env `thenRn` \ export_avails ->
214 traceRn (text "Local top-level environment" $$
215 nest 4 (pprGlobalRdrEnv local_gbl_env)) `thenRn_`
217 -- DEAL WITH DEPRECATIONS
218 rnDeprecs local_gbl_env mod_deprec
219 [d | DeprecD d <- local_decls] `thenRn` \ my_deprecs ->
221 -- DEAL WITH LOCAL FIXITIES
222 fixitiesFromLocalDecls local_gbl_env local_decls `thenRn` \ local_fixity_env ->
225 rnSourceDecls gbl_env local_fixity_env local_decls `thenRn` \ (rn_local_decls, source_fvs) ->
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_`
236 returnRn (print_unqualified, Nothing)
239 -- SLURP IN ALL THE NEEDED DECLARATIONS
240 -- Find out what re-bindable names to use for desugaring
241 getImplicitModuleFVs mod_name rn_local_decls `thenRn` \ implicit_fvs ->
243 export_fvs = availsToNameSet export_avails
244 source_fvs2 = source_fvs `plusFV` export_fvs
245 -- The export_fvs make the exported names look just as if they
246 -- occurred in the source program. For the reasoning, see the
247 -- comments with RnIfaces.mkImportInfo
248 -- It also helps reportUnusedNames, which of course must not complain
249 -- that 'f' isn't mentioned if it is mentioned in the export list
251 source_fvs3 = implicit_fvs `plusFV` source_fvs2
252 -- It's important to do the "plus" this way round, so that
253 -- when compiling the prelude, locally-defined (), Bool, etc
254 -- override the implicit ones.
257 traceRn (text "Source FVs:" <+> fsep (map ppr (nameSetToList source_fvs3))) `thenRn_`
258 slurpImpDecls source_fvs3 `thenRn` \ rn_imp_decls ->
259 rnDump rn_imp_decls rn_local_decls `thenRn_`
261 -- GENERATE THE VERSION/USAGE INFO
262 mkImportInfo mod_name imports `thenRn` \ my_usages ->
264 -- BUILD THE MODULE INTERFACE
266 -- We record fixities even for things that aren't exported,
267 -- so that we can change into the context of this moodule easily
268 fixities = mkNameEnv [ (name, fixity)
269 | FixitySig name fixity loc <- nameEnvElts local_fixity_env
272 -- Sort the exports to make them easier to compare for versions
273 my_exports = groupAvails this_module export_avails
275 final_decls = rn_local_decls ++ rn_imp_decls
277 mod_iface = ModIface { mi_module = this_module,
278 mi_version = initialVersionInfo,
279 mi_usages = my_usages,
281 mi_orphan = panic "is_orphan",
282 mi_exports = my_exports,
283 mi_globals = gbl_env,
284 mi_fixities = fixities,
285 mi_deprecs = my_deprecs,
286 mi_decls = panic "mi_decls"
289 is_exported name = name `elemNameSet` exported_names
290 exported_names = availsToNameSet export_avails
293 -- REPORT UNUSED NAMES, AND DEBUG DUMP
294 reportUnusedNames mod_iface print_unqualified
295 imports global_avail_env
296 source_fvs2 rn_imp_decls `thenRn_`
297 -- NB: source_fvs2: include exports (else we get bogus
298 -- warnings of unused things) but not implicit FVs.
300 returnRn (print_unqualified, Just (is_exported, mod_iface, final_decls))
302 mod_name = moduleName this_module
307 %*********************************************************
309 \subsection{Fixities}
311 %*********************************************************
314 fixitiesFromLocalDecls :: GlobalRdrEnv -> [RdrNameHsDecl] -> RnMG LocalFixityEnv
315 fixitiesFromLocalDecls gbl_env decls
316 = foldlRn getFixities emptyNameEnv decls `thenRn` \ env ->
317 traceRn (text "fixity env" <+> vcat (map ppr (nameEnvElts env))) `thenRn_`
320 getFixities :: LocalFixityEnv -> RdrNameHsDecl -> RnMG LocalFixityEnv
321 getFixities acc (FixD fix)
324 getFixities acc (TyClD (ClassDecl { tcdSigs = sigs}))
325 = foldlRn fix_decl acc [sig | FixSig sig <- sigs]
326 -- Get fixities from class decl sigs too.
327 getFixities acc other_decl
330 fix_decl acc sig@(FixitySig rdr_name fixity loc)
331 = -- Check for fixity decl for something not declared
333 lookupSrcName gbl_env rdr_name `thenRn` \ name ->
335 -- Check for duplicate fixity decl
336 case lookupNameEnv acc name of
337 Just (FixitySig _ _ loc') -> addErrRn (dupFixityDecl rdr_name loc loc') `thenRn_`
340 Nothing -> returnRn (extendNameEnv acc name (FixitySig name fixity loc))
344 %*********************************************************
346 \subsection{Deprecations}
348 %*********************************************************
350 For deprecations, all we do is check that the names are in scope.
351 It's only imported deprecations, dealt with in RnIfaces, that we
352 gather them together.
355 rnDeprecs :: GlobalRdrEnv -> Maybe DeprecTxt
356 -> [RdrNameDeprecation] -> RnMG Deprecations
357 rnDeprecs gbl_env Nothing []
360 rnDeprecs gbl_env (Just txt) decls
361 = mapRn (addErrRn . badDeprec) decls `thenRn_`
362 returnRn (DeprecAll txt)
364 rnDeprecs gbl_env Nothing decls
365 = mapRn rn_deprec decls `thenRn` \ pairs ->
366 returnRn (DeprecSome (mkNameEnv (catMaybes pairs)))
368 rn_deprec (Deprecation rdr_name txt loc)
370 lookupSrcName gbl_env rdr_name `thenRn` \ name ->
371 returnRn (Just (name, (name,txt)))
375 %************************************************************************
377 \subsection{Grabbing the old interface file and checking versions}
379 %************************************************************************
382 checkOldIface :: GhciMode
384 -> HomeIfaceTable -> HomeSymbolTable
385 -> PersistentCompilerState
387 -> Bool -- Source unchanged
388 -> Maybe ModIface -- Old interface from compilation manager, if any
389 -> IO (PersistentCompilerState, Bool, (RecompileRequired, Maybe ModIface))
390 -- True <=> errors happened
392 checkOldIface ghci_mode dflags hit hst pcs iface_path source_unchanged maybe_iface
393 = runRn dflags hit hst pcs (panic "Bogus module") $
395 -- CHECK WHETHER THE SOURCE HAS CHANGED
396 ( if not source_unchanged then
397 traceHiDiffsRn (nest 4 (text "Source file changed or recompilation check turned off"))
398 else returnRn () ) `thenRn_`
400 -- If the source has changed and we're in interactive mode, avoid reading
401 -- an interface; just return the one we might have been supplied with.
402 if ghci_mode == Interactive && not source_unchanged then
403 returnRn (outOfDate, maybe_iface)
407 Just old_iface -> -- Use the one we already have
408 setModuleRn (mi_module old_iface) (check_versions old_iface)
410 Nothing -- try and read it from a file
411 -> readIface iface_path `thenRn` \ read_result ->
413 Left err -> -- Old interface file not found, or garbled; give up
415 text "Cannot read old interface file:"
416 $$ nest 4 err) `thenRn_`
417 returnRn (outOfDate, Nothing)
420 -> setModuleRn (pi_mod parsed_iface) $
421 loadOldIface parsed_iface `thenRn` \ m_iface ->
422 check_versions m_iface
424 check_versions :: ModIface -> RnMG (RecompileRequired, Maybe ModIface)
426 | not source_unchanged
427 = returnRn (outOfDate, Just iface)
430 recompileRequired iface_path iface `thenRn` \ recompile ->
431 returnRn (recompile, Just iface)
434 I think the following function should now have a more representative name,
438 loadOldIface :: ParsedIface -> RnMG ModIface
440 loadOldIface parsed_iface
441 = let iface = parsed_iface
445 loadHomeDecls (pi_decls iface) `thenRn` \ decls ->
446 loadHomeRules (pi_rules iface) `thenRn` \ rules ->
447 loadHomeInsts (pi_insts iface) `thenRn` \ insts ->
448 returnRn (decls, rules, insts)
450 `thenRn` \ ((decls_vers, new_decls), (rule_vers, new_rules), new_insts) ->
452 mapRn loadHomeUsage (pi_usages iface) `thenRn` \ usages ->
453 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
454 loadFixDecls mod (pi_fixity iface) `thenRn` \ fix_env ->
455 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
457 version = VersionInfo { vers_module = pi_vers iface,
458 vers_exports = export_vers,
459 vers_rules = rule_vers,
460 vers_decls = decls_vers }
462 decls = mkIfaceDecls new_decls new_rules new_insts
464 mod_iface = ModIface { mi_module = mod, mi_version = version,
465 mi_exports = avails, mi_usages = usages,
466 mi_boot = False, mi_orphan = pi_orphan iface,
467 mi_fixities = fix_env, mi_deprecs = deprec_env,
469 mi_globals = mkIfaceGlobalRdrEnv avails
476 loadHomeDecls :: [(Version, RdrNameTyClDecl)]
477 -> RnMS (NameEnv Version, [RenamedTyClDecl])
478 loadHomeDecls decls = foldlRn loadHomeDecl (emptyNameEnv, []) decls
480 loadHomeDecl :: (NameEnv Version, [RenamedTyClDecl])
481 -> (Version, RdrNameTyClDecl)
482 -> RnMS (NameEnv Version, [RenamedTyClDecl])
483 loadHomeDecl (version_map, decls) (version, decl)
484 = rnTyClDecl decl `thenRn` \ decl' ->
485 returnRn (extendNameEnv version_map (tyClDeclName decl') version, decl':decls)
488 loadHomeRules :: (Version, [RdrNameRuleDecl])
489 -> RnMS (Version, [RenamedRuleDecl])
490 loadHomeRules (version, rules)
491 = mapRn rnIfaceRuleDecl rules `thenRn` \ rules' ->
492 returnRn (version, rules')
495 loadHomeInsts :: [RdrNameInstDecl]
496 -> RnMS [RenamedInstDecl]
497 loadHomeInsts insts = mapRn rnInstDecl insts
500 loadHomeUsage :: ImportVersion OccName
501 -> RnMG (ImportVersion Name)
502 loadHomeUsage (mod_name, orphans, is_boot, whats_imported)
503 = rn_imps whats_imported `thenRn` \ whats_imported' ->
504 returnRn (mod_name, orphans, is_boot, whats_imported')
506 rn_imps NothingAtAll = returnRn NothingAtAll
507 rn_imps (Everything v) = returnRn (Everything v)
508 rn_imps (Specifically mv ev items rv) = mapRn rn_imp items `thenRn` \ items' ->
509 returnRn (Specifically mv ev items' rv)
510 rn_imp (occ,vers) = newGlobalName mod_name occ `thenRn` \ name ->
516 %*********************************************************
518 \subsection{Closing up the interface decls}
520 %*********************************************************
522 Suppose we discover we don't need to recompile. Then we start from the
523 IfaceDecls in the ModIface, and fluff them up by sucking in all the decls they need.
526 closeIfaceDecls :: DynFlags
527 -> HomeIfaceTable -> HomeSymbolTable
528 -> PersistentCompilerState
529 -> ModIface -- Get the decls from here
530 -> IO (PersistentCompilerState, Bool, [RenamedHsDecl])
531 -- True <=> errors happened
532 closeIfaceDecls dflags hit hst pcs
533 mod_iface@(ModIface { mi_module = mod, mi_decls = iface_decls })
534 = runRn dflags hit hst pcs mod $
537 rule_decls = dcl_rules iface_decls
538 inst_decls = dcl_insts iface_decls
539 tycl_decls = dcl_tycl iface_decls
540 decls = map RuleD rule_decls ++
541 map InstD inst_decls ++
543 needed = unionManyNameSets (map ruleDeclFVs rule_decls) `unionNameSets`
544 unionManyNameSets (map instDeclFVs inst_decls) `unionNameSets`
545 unionManyNameSets (map tyClDeclFVs tycl_decls)
546 local_names = foldl add emptyNameSet tycl_decls
547 add names decl = addListToNameSet names (map fst (tyClDeclSysNames decl ++ tyClDeclNames decl))
550 recordLocalSlurps local_names `thenRn_`
552 -- Do the transitive closure
553 closeDecls decls (needed `plusFV` implicit_fvs) `thenRn` \closed_decls ->
554 rnDump [] closed_decls `thenRn_`
555 returnRn closed_decls
557 implicit_fvs = ubiquitousNames -- Data type decls with record selectors,
558 -- which may appear in the decls, need unpackCString
559 -- and friends. It's easier to just grab them right now.
562 %*********************************************************
564 \subsection{Unused names}
566 %*********************************************************
569 reportUnusedNames :: ModIface -> PrintUnqualified
570 -> [RdrNameImportDecl]
572 -> NameSet -- Used in this module
575 reportUnusedNames my_mod_iface unqual imports avail_env
576 used_names imported_decls
577 = warnUnusedModules unused_imp_mods `thenRn_`
578 warnUnusedLocalBinds bad_locals `thenRn_`
579 warnUnusedImports bad_imp_names `thenRn_`
580 printMinimalImports this_mod unqual minimal_imports
582 this_mod = mi_module my_mod_iface
583 gbl_env = mi_globals my_mod_iface
585 -- Now, a use of C implies a use of T,
586 -- if C was brought into scope by T(..) or T(C)
587 really_used_names = used_names `unionNameSets`
588 mkNameSet [ parent_name
589 | sub_name <- nameSetToList used_names
591 -- Usually, every used name will appear in avail_env, but there
592 -- is one time when it doesn't: tuples and other built in syntax. When you
593 -- write (a,b) that gives rise to a *use* of "(,)", so that the
594 -- instances will get pulled in, but the tycon "(,)" isn't actually
595 -- in scope. Also, (-x) gives rise to an implicit use of 'negate';
596 -- similarly, 3.5 gives rise to an implcit use of :%
597 -- Hence the silent 'False' in all other cases
599 , Just parent_name <- [case lookupNameEnv avail_env sub_name of
600 Just (AvailTC n _) -> Just n
604 -- Collect the defined names from the in-scope environment
605 -- Look for the qualified ones only, else get duplicates
606 defined_names :: [GlobalRdrElt]
607 defined_names = foldRdrEnv add [] gbl_env
608 add rdr_name ns acc | isQual rdr_name = ns ++ acc
611 defined_and_used, defined_but_not_used :: [GlobalRdrElt]
612 (defined_and_used, defined_but_not_used) = partition used defined_names
613 used (GRE name _ _) = name `elemNameSet` really_used_names
615 -- Filter out the ones only defined implicitly
617 bad_locals = [n | (GRE n LocalDef _) <- defined_but_not_used]
619 bad_imp_names :: [(Name,Provenance)]
620 bad_imp_names = [(n,p) | GRE n p@(NonLocalDef (UserImport mod _ True)) _ <- defined_but_not_used,
621 not (module_unused mod)]
623 -- inst_mods are directly-imported modules that
624 -- contain instance decl(s) that the renamer decided to suck in
625 -- It's not necessarily redundant to import such modules.
631 -- The import M() is not *necessarily* redundant, even if
632 -- we suck in no instance decls from M (e.g. it contains
633 -- no instance decls, or This contains no code). It may be
634 -- that we import M solely to ensure that M's orphan instance
635 -- decls (or those in its imports) are visible to people who
636 -- import This. Sigh.
637 -- There's really no good way to detect this, so the error message
638 -- in RnEnv.warnUnusedModules is weakened instead
639 inst_mods :: [ModuleName]
640 inst_mods = [m | InstD (InstDecl _ _ _ (Just dfun) _) <- imported_decls,
641 let m = moduleName (nameModule dfun),
642 m `elem` direct_import_mods
645 -- To figure out the minimal set of imports, start with the things
646 -- that are in scope (i.e. in gbl_env). Then just combine them
647 -- into a bunch of avails, so they are properly grouped
648 minimal_imports :: FiniteMap ModuleName AvailEnv
649 minimal_imports0 = emptyFM
650 minimal_imports1 = foldr add_name minimal_imports0 defined_and_used
651 minimal_imports = foldr add_inst_mod minimal_imports1 inst_mods
653 -- We've carefully preserved the provenance so that we can
654 -- construct minimal imports that import the name by (one of)
655 -- the same route(s) as the programmer originally did.
656 add_name (GRE n (NonLocalDef (UserImport m _ _)) _) acc = addToFM_C plusAvailEnv acc (moduleName m)
657 (unitAvailEnv (mk_avail n))
658 add_name (GRE n other_prov _) acc = acc
660 mk_avail n = case lookupNameEnv avail_env n of
661 Just (AvailTC m _) | n==m -> AvailTC n [n]
662 | otherwise -> AvailTC m [n,m]
663 Just avail -> Avail n
664 Nothing -> pprPanic "mk_avail" (ppr n)
667 | m `elemFM` acc = acc -- We import something already
668 | otherwise = addToFM acc m emptyAvailEnv
669 -- Add an empty collection of imports for a module
670 -- from which we have sucked only instance decls
672 direct_import_mods :: [ModuleName]
673 direct_import_mods = nub [m | ImportDecl m _ _ _ _ _ <- imports]
675 -- unused_imp_mods are the directly-imported modules
676 -- that are not mentioned in minimal_imports
677 unused_imp_mods = [m | m <- direct_import_mods,
678 not (maybeToBool (lookupFM minimal_imports m)),
681 module_unused :: Module -> Bool
682 module_unused mod = moduleName mod `elem` unused_imp_mods
685 -- ToDo: deal with original imports with 'qualified' and 'as M' clauses
686 printMinimalImports :: Module -- This module
688 -> FiniteMap ModuleName AvailEnv -- Minimal imports
690 printMinimalImports this_mod unqual imps
691 = ifOptRn Opt_D_dump_minimal_imports $
693 mapRn to_ies (fmToList imps) `thenRn` \ mod_ies ->
694 ioToRnM (do { h <- openFile filename WriteMode ;
695 printForUser h unqual (vcat (map ppr_mod_ie mod_ies))
699 filename = moduleNameUserString (moduleName this_mod) ++ ".imports"
700 ppr_mod_ie (mod_name, ies)
701 | mod_name == pRELUDE_Name
704 = ptext SLIT("import") <+> ppr mod_name <>
705 parens (fsep (punctuate comma (map ppr ies)))
707 to_ies (mod, avail_env) = mapRn to_ie (availEnvElts avail_env) `thenRn` \ ies ->
710 to_ie :: AvailInfo -> RnMG (IE Name)
711 -- The main trick here is that if we're importing all the constructors
712 -- we want to say "T(..)", but if we're importing only a subset we want
713 -- to say "T(A,B,C)". So we have to find out what the module exports.
714 to_ie (Avail n) = returnRn (IEVar n)
715 to_ie (AvailTC n [m]) = ASSERT( n==m )
716 returnRn (IEThingAbs n)
718 = loadInterface (text "Compute minimal imports from" <+> ppr n_mod) n_mod ImportBySystem `thenRn` \ iface ->
719 case [xs | (m,as) <- mi_exports iface,
723 [xs] | all (`elem` ns) xs -> returnRn (IEThingAll n)
724 | otherwise -> returnRn (IEThingWith n (filter (/= n) ns))
725 other -> pprTrace "to_ie" (ppr n <+> ppr (nameModule n) <+> ppr other) $
728 n_mod = moduleName (nameModule n)
730 rnDump :: [RenamedHsDecl] -- Renamed imported decls
731 -> [RenamedHsDecl] -- Renamed local decls
733 rnDump imp_decls local_decls
734 = doptRn Opt_D_dump_rn_trace `thenRn` \ dump_rn_trace ->
735 doptRn Opt_D_dump_rn_stats `thenRn` \ dump_rn_stats ->
736 doptRn Opt_D_dump_rn `thenRn` \ dump_rn ->
737 getIfacesRn `thenRn` \ ifaces ->
739 ioToRnM (do { dumpIfSet (dump_rn_trace || dump_rn_stats || dump_rn)
741 (getRnStats imp_decls ifaces) ;
743 dumpIfSet dump_rn "Renamer:"
744 (vcat (map ppr (local_decls ++ imp_decls)))
751 %*********************************************************
753 \subsection{Statistics}
755 %*********************************************************
758 getRnStats :: [RenamedHsDecl] -> Ifaces -> SDoc
759 getRnStats imported_decls ifaces
760 = hcat [text "Renamer stats: ", stats]
762 n_mods = length [() | _ <- moduleEnvElts (iPIT ifaces)]
763 -- This is really only right for a one-shot compile
765 (decls_map, n_decls_slurped) = iDecls ifaces
767 n_decls_left = length [decl | (avail, True, (_,decl)) <- nameEnvElts decls_map
768 -- Data, newtype, and class decls are in the decls_fm
769 -- under multiple names; the tycon/class, and each
770 -- constructor/class op too.
771 -- The 'True' selects just the 'main' decl
774 (insts_left, n_insts_slurped) = iInsts ifaces
775 n_insts_left = length (bagToList insts_left)
777 (rules_left, n_rules_slurped) = iRules ifaces
778 n_rules_left = length (bagToList rules_left)
781 [int n_mods <+> text "interfaces read",
782 hsep [ int n_decls_slurped, text "type/class/variable imported, out of",
783 int (n_decls_slurped + n_decls_left), text "read"],
784 hsep [ int n_insts_slurped, text "instance decls imported, out of",
785 int (n_insts_slurped + n_insts_left), text "read"],
786 hsep [ int n_rules_slurped, text "rule decls imported, out of",
787 int (n_rules_slurped + n_rules_left), text "read"]
792 %************************************************************************
794 \subsection{Errors and warnings}
796 %************************************************************************
799 dupFixityDecl rdr_name loc1 loc2
800 = vcat [ptext SLIT("Multiple fixity declarations for") <+> quotes (ppr rdr_name),
801 ptext SLIT("at ") <+> ppr loc1,
802 ptext SLIT("and") <+> ppr loc2]
805 = sep [ptext SLIT("Illegal deprecation when whole module is deprecated"),