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, rnSyntaxNames,
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 ( SyntaxMap, vanillaSyntaxMap, 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,
68 import CmStaticInfo ( GhciMode(..) )
69 import List ( partition, nub )
75 %*********************************************************
77 \subsection{The two main wrappers}
79 %*********************************************************
82 renameModule :: DynFlags
83 -> HomeIfaceTable -> HomeSymbolTable
84 -> PersistentCompilerState
85 -> Module -> RdrNameHsModule
86 -> IO (PersistentCompilerState, PrintUnqualified,
87 Maybe (IsExported, ModIface, (SyntaxMap, [RenamedHsDecl])))
88 -- Nothing => some error occurred in the renamer
90 renameModule dflags hit hst pcs this_module rdr_module
91 = renameSource dflags hit hst pcs this_module $
92 rename this_module rdr_module
97 renameStmt :: DynFlags
98 -> HomeIfaceTable -> HomeSymbolTable
99 -> PersistentCompilerState
100 -> Module -- current context (scope to compile in)
101 -> Module -- current module
102 -> LocalRdrEnv -- current context (temp bindings)
103 -> RdrNameStmt -- parsed stmt
104 -> IO ( PersistentCompilerState,
106 Maybe ([Name], (SyntaxMap, RenamedStmt, [RenamedHsDecl]))
109 renameStmt dflags hit hst pcs scope_module this_module local_env stmt
110 = renameSource dflags hit hst pcs this_module $
112 -- Load the interface for the context module, so
113 -- that we can get its top-level lexical environment
114 -- Bale out if we fail to do this
115 loadInterface doc (moduleName scope_module) ImportByUser `thenRn` \ iface ->
116 let rdr_env = mi_globals iface
117 print_unqual = unQualInScope rdr_env
119 checkErrsRn `thenRn` \ no_errs_so_far ->
120 if not no_errs_so_far then
121 returnRn (print_unqual, Nothing)
125 initRnMS rdr_env local_env emptyLocalFixityEnv CmdLineMode (
126 rnStmt stmt $ \ stmt' ->
127 returnRn (([], stmt'), emptyFVs)
128 ) `thenRn` \ ((binders, stmt), fvs) ->
130 -- Bale out if we fail
131 checkErrsRn `thenRn` \ no_errs_so_far ->
132 if not no_errs_so_far then
133 doDump [] stmt [] `thenRn_` returnRn (print_unqual, Nothing)
136 -- Add implicit free vars, and close decls
137 getImplicitStmtFVs `thenRn` \ implicit_fvs ->
139 filtered_fvs = fvs `delListFromNameSet` rdrEnvElts local_env
140 source_fvs = implicit_fvs `plusFV` filtered_fvs
142 slurpImpDecls source_fvs `thenRn` \ decls ->
144 doDump binders stmt decls `thenRn_`
145 returnRn (print_unqual, Just (binders, (vanillaSyntaxMap, stmt, decls)))
148 doc = text "context for compiling expression"
150 doDump :: [Name] -> RenamedStmt -> [RenamedHsDecl] -> RnMG (Either IOError ())
151 doDump bndrs stmt decls
152 = getDOptsRn `thenRn` \ dflags ->
153 ioToRnM (dumpIfSet_dyn dflags Opt_D_dump_rn "Renamer:"
154 (vcat [text "Binders:" <+> ppr bndrs,
156 vcat (map ppr decls)]))
160 %*********************************************************
162 \subsection{The main function: rename}
164 %*********************************************************
167 renameSource :: DynFlags
168 -> HomeIfaceTable -> HomeSymbolTable
169 -> PersistentCompilerState
171 -> RnMG (PrintUnqualified, Maybe r)
172 -> IO (PersistentCompilerState, PrintUnqualified, Maybe r)
173 -- Nothing => some error occurred in the renamer
175 renameSource dflags hit hst old_pcs this_module thing_inside
176 = do { showPass dflags "Renamer"
178 -- Initialise the renamer monad
179 ; (new_pcs, msgs, (print_unqual, maybe_rn_stuff))
180 <- initRn dflags hit hst old_pcs this_module thing_inside
182 -- Print errors from renaming
183 ; printErrorsAndWarnings print_unqual msgs ;
185 -- Return results. No harm in updating the PCS
186 ; if errorsFound msgs then
187 return (new_pcs, print_unqual, Nothing)
189 return (new_pcs, print_unqual, maybe_rn_stuff)
194 rename :: Module -> RdrNameHsModule
195 -> RnMG (PrintUnqualified, Maybe (IsExported, ModIface, (SyntaxMap, [RenamedHsDecl])))
196 rename this_module contents@(HsModule _ _ exports imports local_decls mod_deprec loc)
199 -- FIND THE GLOBAL NAME ENVIRONMENT
200 getGlobalNames this_module contents `thenRn` \ (gbl_env, local_gbl_env, all_avails@(_, global_avail_env)) ->
202 print_unqualified = unQualInScope gbl_env
204 -- Exit if we've found any errors
205 checkErrsRn `thenRn` \ no_errs_so_far ->
206 if not no_errs_so_far then
207 -- Found errors already, so exit now
208 rnDump [] [] `thenRn_`
209 returnRn (print_unqualified, Nothing)
212 -- PROCESS EXPORT LIST
213 exportsFromAvail mod_name exports all_avails gbl_env `thenRn` \ export_avails ->
215 traceRn (text "Local top-level environment" $$
216 nest 4 (pprGlobalRdrEnv local_gbl_env)) `thenRn_`
218 -- DEAL WITH DEPRECATIONS
219 rnDeprecs local_gbl_env mod_deprec
220 [d | DeprecD d <- local_decls] `thenRn` \ my_deprecs ->
222 -- DEAL WITH LOCAL FIXITIES
223 fixitiesFromLocalDecls local_gbl_env local_decls `thenRn` \ local_fixity_env ->
226 rnSourceDecls gbl_env local_fixity_env local_decls `thenRn` \ (rn_local_decls, source_fvs) ->
228 -- EXIT IF ERRORS FOUND
229 -- We exit here if there are any errors in the source, *before*
230 -- we attempt to slurp the decls from the interfaces, otherwise
231 -- the slurped decls may get lost when we return up the stack
232 -- to hscMain/hscExpr.
233 checkErrsRn `thenRn` \ no_errs_so_far ->
234 if not no_errs_so_far then
235 -- Found errors already, so exit now
236 rnDump [] rn_local_decls `thenRn_`
237 returnRn (print_unqualified, Nothing)
240 -- SLURP IN ALL THE NEEDED DECLARATIONS
241 -- Find out what re-bindable names to use for desugaring
242 getImplicitModuleFVs mod_name rn_local_decls `thenRn` \ implicit_fvs ->
243 rnSyntaxNames gbl_env source_fvs `thenRn` \ (source_fvs1, sugar_map) ->
245 export_fvs = availsToNameSet export_avails
246 source_fvs2 = source_fvs1 `plusFV` export_fvs
247 -- The export_fvs make the exported names look just as if they
248 -- occurred in the source program. For the reasoning, see the
249 -- comments with RnIfaces.mkImportInfo
250 -- It also helps reportUnusedNames, which of course must not complain
251 -- that 'f' isn't mentioned if it is mentioned in the export list
253 source_fvs3 = implicit_fvs `plusFV` source_fvs2
254 -- It's important to do the "plus" this way round, so that
255 -- when compiling the prelude, locally-defined (), Bool, etc
256 -- override the implicit ones.
259 traceRn (text "Source FVs:" <+> fsep (map ppr (nameSetToList source_fvs3))) `thenRn_`
260 slurpImpDecls source_fvs3 `thenRn` \ rn_imp_decls ->
261 rnDump rn_imp_decls rn_local_decls `thenRn_`
263 -- GENERATE THE VERSION/USAGE INFO
264 mkImportInfo mod_name imports `thenRn` \ my_usages ->
266 -- BUILD THE MODULE INTERFACE
268 -- We record fixities even for things that aren't exported,
269 -- so that we can change into the context of this moodule easily
270 fixities = mkNameEnv [ (name, fixity)
271 | FixitySig name fixity loc <- nameEnvElts local_fixity_env
274 -- Sort the exports to make them easier to compare for versions
275 my_exports = groupAvails this_module export_avails
277 final_decls = rn_local_decls ++ rn_imp_decls
279 mod_iface = ModIface { mi_module = this_module,
280 mi_version = initialVersionInfo,
281 mi_usages = my_usages,
283 mi_orphan = panic "is_orphan",
284 mi_exports = my_exports,
285 mi_globals = gbl_env,
286 mi_fixities = fixities,
287 mi_deprecs = my_deprecs,
288 mi_decls = panic "mi_decls"
291 is_exported name = name `elemNameSet` exported_names
292 exported_names = availsToNameSet export_avails
295 -- REPORT UNUSED NAMES, AND DEBUG DUMP
296 reportUnusedNames mod_iface print_unqualified
297 imports global_avail_env
298 source_fvs2 rn_imp_decls `thenRn_`
299 -- NB: source_fvs2: include exports (else we get bogus
300 -- warnings of unused things) but not implicit FVs.
302 returnRn (print_unqualified, Just (is_exported, mod_iface, (sugar_map, final_decls)))
304 mod_name = moduleName this_module
309 %*********************************************************
311 \subsection{Fixities}
313 %*********************************************************
316 fixitiesFromLocalDecls :: GlobalRdrEnv -> [RdrNameHsDecl] -> RnMG LocalFixityEnv
317 fixitiesFromLocalDecls gbl_env decls
318 = foldlRn getFixities emptyNameEnv decls `thenRn` \ env ->
319 traceRn (text "fixity env" <+> vcat (map ppr (nameEnvElts env))) `thenRn_`
322 getFixities :: LocalFixityEnv -> RdrNameHsDecl -> RnMG LocalFixityEnv
323 getFixities acc (FixD fix)
326 getFixities acc (TyClD (ClassDecl { tcdSigs = sigs}))
327 = foldlRn fix_decl acc [sig | FixSig sig <- sigs]
328 -- Get fixities from class decl sigs too.
329 getFixities acc other_decl
332 fix_decl acc sig@(FixitySig rdr_name fixity loc)
333 = -- Check for fixity decl for something not declared
335 lookupSrcName gbl_env rdr_name `thenRn` \ name ->
337 -- Check for duplicate fixity decl
338 case lookupNameEnv acc name of
339 Just (FixitySig _ _ loc') -> addErrRn (dupFixityDecl rdr_name loc loc') `thenRn_`
342 Nothing -> returnRn (extendNameEnv acc name (FixitySig name fixity loc))
346 %*********************************************************
348 \subsection{Deprecations}
350 %*********************************************************
352 For deprecations, all we do is check that the names are in scope.
353 It's only imported deprecations, dealt with in RnIfaces, that we
354 gather them together.
357 rnDeprecs :: GlobalRdrEnv -> Maybe DeprecTxt
358 -> [RdrNameDeprecation] -> RnMG Deprecations
359 rnDeprecs gbl_env Nothing []
362 rnDeprecs gbl_env (Just txt) decls
363 = mapRn (addErrRn . badDeprec) decls `thenRn_`
364 returnRn (DeprecAll txt)
366 rnDeprecs gbl_env Nothing decls
367 = mapRn rn_deprec decls `thenRn` \ pairs ->
368 returnRn (DeprecSome (mkNameEnv (catMaybes pairs)))
370 rn_deprec (Deprecation rdr_name txt loc)
372 lookupSrcName gbl_env rdr_name `thenRn` \ name ->
373 returnRn (Just (name, (name,txt)))
377 %************************************************************************
379 \subsection{Grabbing the old interface file and checking versions}
381 %************************************************************************
384 checkOldIface :: GhciMode
386 -> HomeIfaceTable -> HomeSymbolTable
387 -> PersistentCompilerState
389 -> Bool -- Source unchanged
390 -> Maybe ModIface -- Old interface from compilation manager, if any
391 -> IO (PersistentCompilerState, Bool, (RecompileRequired, Maybe ModIface))
392 -- True <=> errors happened
394 checkOldIface ghci_mode dflags hit hst pcs iface_path source_unchanged maybe_iface
395 = runRn dflags hit hst pcs (panic "Bogus module") $
397 -- CHECK WHETHER THE SOURCE HAS CHANGED
398 ( if not source_unchanged then
399 traceHiDiffsRn (nest 4 (text "Source file changed or recompilation check turned off"))
400 else returnRn () ) `thenRn_`
402 -- If the source has changed and we're in interactive mode, avoid reading
403 -- an interface; just return the one we might have been supplied with.
404 if ghci_mode == Interactive && not source_unchanged then
405 returnRn (outOfDate, maybe_iface)
409 Just old_iface -> -- Use the one we already have
410 setModuleRn (mi_module old_iface) (check_versions old_iface)
412 Nothing -- try and read it from a file
413 -> readIface iface_path `thenRn` \ read_result ->
415 Left err -> -- Old interface file not found, or garbled; give up
417 text "Cannot read old interface file:"
418 $$ nest 4 err) `thenRn_`
419 returnRn (outOfDate, Nothing)
422 -> setModuleRn (pi_mod parsed_iface) $
423 loadOldIface parsed_iface `thenRn` \ m_iface ->
424 check_versions m_iface
426 check_versions :: ModIface -> RnMG (RecompileRequired, Maybe ModIface)
428 | not source_unchanged
429 = returnRn (outOfDate, Just iface)
432 recompileRequired iface_path iface `thenRn` \ recompile ->
433 returnRn (recompile, Just iface)
436 I think the following function should now have a more representative name,
440 loadOldIface :: ParsedIface -> RnMG ModIface
442 loadOldIface parsed_iface
443 = let iface = parsed_iface
447 loadHomeDecls (pi_decls iface) `thenRn` \ decls ->
448 loadHomeRules (pi_rules iface) `thenRn` \ rules ->
449 loadHomeInsts (pi_insts iface) `thenRn` \ insts ->
450 returnRn (decls, rules, insts)
452 `thenRn` \ ((decls_vers, new_decls), (rule_vers, new_rules), new_insts) ->
454 mapRn loadHomeUsage (pi_usages iface) `thenRn` \ usages ->
455 loadExports (pi_exports iface) `thenRn` \ (export_vers, avails) ->
456 loadFixDecls mod (pi_fixity iface) `thenRn` \ fix_env ->
457 loadDeprecs mod (pi_deprecs iface) `thenRn` \ deprec_env ->
459 version = VersionInfo { vers_module = pi_vers iface,
460 vers_exports = export_vers,
461 vers_rules = rule_vers,
462 vers_decls = decls_vers }
464 decls = mkIfaceDecls new_decls new_rules new_insts
466 mod_iface = ModIface { mi_module = mod, mi_version = version,
467 mi_exports = avails, mi_usages = usages,
468 mi_boot = False, mi_orphan = pi_orphan iface,
469 mi_fixities = fix_env, mi_deprecs = deprec_env,
471 mi_globals = mkIfaceGlobalRdrEnv avails
478 loadHomeDecls :: [(Version, RdrNameTyClDecl)]
479 -> RnMS (NameEnv Version, [RenamedTyClDecl])
480 loadHomeDecls decls = foldlRn loadHomeDecl (emptyNameEnv, []) decls
482 loadHomeDecl :: (NameEnv Version, [RenamedTyClDecl])
483 -> (Version, RdrNameTyClDecl)
484 -> RnMS (NameEnv Version, [RenamedTyClDecl])
485 loadHomeDecl (version_map, decls) (version, decl)
486 = rnTyClDecl decl `thenRn` \ decl' ->
487 returnRn (extendNameEnv version_map (tyClDeclName decl') version, decl':decls)
490 loadHomeRules :: (Version, [RdrNameRuleDecl])
491 -> RnMS (Version, [RenamedRuleDecl])
492 loadHomeRules (version, rules)
493 = mapRn rnIfaceRuleDecl rules `thenRn` \ rules' ->
494 returnRn (version, rules')
497 loadHomeInsts :: [RdrNameInstDecl]
498 -> RnMS [RenamedInstDecl]
499 loadHomeInsts insts = mapRn rnInstDecl insts
502 loadHomeUsage :: ImportVersion OccName
503 -> RnMG (ImportVersion Name)
504 loadHomeUsage (mod_name, orphans, is_boot, whats_imported)
505 = rn_imps whats_imported `thenRn` \ whats_imported' ->
506 returnRn (mod_name, orphans, is_boot, whats_imported')
508 rn_imps NothingAtAll = returnRn NothingAtAll
509 rn_imps (Everything v) = returnRn (Everything v)
510 rn_imps (Specifically mv ev items rv) = mapRn rn_imp items `thenRn` \ items' ->
511 returnRn (Specifically mv ev items' rv)
512 rn_imp (occ,vers) = newGlobalName mod_name occ `thenRn` \ name ->
518 %*********************************************************
520 \subsection{Closing up the interface decls}
522 %*********************************************************
524 Suppose we discover we don't need to recompile. Then we start from the
525 IfaceDecls in the ModIface, and fluff them up by sucking in all the decls they need.
528 closeIfaceDecls :: DynFlags
529 -> HomeIfaceTable -> HomeSymbolTable
530 -> PersistentCompilerState
531 -> ModIface -- Get the decls from here
532 -> IO (PersistentCompilerState, Bool, [RenamedHsDecl])
533 -- True <=> errors happened
534 closeIfaceDecls dflags hit hst pcs
535 mod_iface@(ModIface { mi_module = mod, mi_decls = iface_decls })
536 = runRn dflags hit hst pcs mod $
539 rule_decls = dcl_rules iface_decls
540 inst_decls = dcl_insts iface_decls
541 tycl_decls = dcl_tycl iface_decls
542 decls = map RuleD rule_decls ++
543 map InstD inst_decls ++
545 needed = unionManyNameSets (map ruleDeclFVs rule_decls) `unionNameSets`
546 unionManyNameSets (map instDeclFVs inst_decls) `unionNameSets`
547 unionManyNameSets (map tyClDeclFVs tycl_decls)
548 local_names = foldl add emptyNameSet tycl_decls
549 add names decl = addListToNameSet names (map fst (tyClDeclSysNames decl ++ tyClDeclNames decl))
552 recordLocalSlurps local_names `thenRn_`
554 -- Do the transitive closure
555 closeDecls decls (needed `plusFV` implicit_fvs) `thenRn` \closed_decls ->
556 rnDump [] closed_decls `thenRn_`
557 returnRn closed_decls
559 implicit_fvs = ubiquitousNames -- Data type decls with record selectors,
560 -- which may appear in the decls, need unpackCString
561 -- and friends. It's easier to just grab them right now.
564 %*********************************************************
566 \subsection{Unused names}
568 %*********************************************************
571 reportUnusedNames :: ModIface -> PrintUnqualified
572 -> [RdrNameImportDecl]
574 -> NameSet -- Used in this module
577 reportUnusedNames my_mod_iface unqual imports avail_env
578 used_names imported_decls
579 = warnUnusedModules unused_imp_mods `thenRn_`
580 warnUnusedLocalBinds bad_locals `thenRn_`
581 warnUnusedImports bad_imp_names `thenRn_`
582 printMinimalImports this_mod unqual minimal_imports
584 this_mod = mi_module my_mod_iface
585 gbl_env = mi_globals my_mod_iface
587 -- Now, a use of C implies a use of T,
588 -- if C was brought into scope by T(..) or T(C)
589 really_used_names = used_names `unionNameSets`
590 mkNameSet [ parent_name
591 | sub_name <- nameSetToList used_names
593 -- Usually, every used name will appear in avail_env, but there
594 -- is one time when it doesn't: tuples and other built in syntax. When you
595 -- write (a,b) that gives rise to a *use* of "(,)", so that the
596 -- instances will get pulled in, but the tycon "(,)" isn't actually
597 -- in scope. Also, (-x) gives rise to an implicit use of 'negate';
598 -- similarly, 3.5 gives rise to an implcit use of :%
599 -- Hence the silent 'False' in all other cases
601 , Just parent_name <- [case lookupNameEnv avail_env sub_name of
602 Just (AvailTC n _) -> Just n
606 -- Collect the defined names from the in-scope environment
607 -- Look for the qualified ones only, else get duplicates
608 defined_names :: [GlobalRdrElt]
609 defined_names = foldRdrEnv add [] gbl_env
610 add rdr_name ns acc | isQual rdr_name = ns ++ acc
613 defined_and_used, defined_but_not_used :: [GlobalRdrElt]
614 (defined_and_used, defined_but_not_used) = partition used defined_names
615 used (GRE name _ _) = name `elemNameSet` really_used_names
617 -- Filter out the ones only defined implicitly
619 bad_locals = [n | (GRE n LocalDef _) <- defined_but_not_used]
621 bad_imp_names :: [(Name,Provenance)]
622 bad_imp_names = [(n,p) | GRE n p@(NonLocalDef (UserImport mod _ True)) _ <- defined_but_not_used,
623 not (module_unused mod)]
625 -- inst_mods are directly-imported modules that
626 -- contain instance decl(s) that the renamer decided to suck in
627 -- It's not necessarily redundant to import such modules.
633 -- The import M() is not *necessarily* redundant, even if
634 -- we suck in no instance decls from M (e.g. it contains
635 -- no instance decls, or This contains no code). It may be
636 -- that we import M solely to ensure that M's orphan instance
637 -- decls (or those in its imports) are visible to people who
638 -- import This. Sigh.
639 -- There's really no good way to detect this, so the error message
640 -- in RnEnv.warnUnusedModules is weakened instead
641 inst_mods :: [ModuleName]
642 inst_mods = [m | InstD (InstDecl _ _ _ (Just dfun) _) <- imported_decls,
643 let m = moduleName (nameModule dfun),
644 m `elem` direct_import_mods
647 -- To figure out the minimal set of imports, start with the things
648 -- that are in scope (i.e. in gbl_env). Then just combine them
649 -- into a bunch of avails, so they are properly grouped
650 minimal_imports :: FiniteMap ModuleName AvailEnv
651 minimal_imports0 = emptyFM
652 minimal_imports1 = foldr add_name minimal_imports0 defined_and_used
653 minimal_imports = foldr add_inst_mod minimal_imports1 inst_mods
655 -- We've carefully preserved the provenance so that we can
656 -- construct minimal imports that import the name by (one of)
657 -- the same route(s) as the programmer originally did.
658 add_name (GRE n (NonLocalDef (UserImport m _ _)) _) acc = addToFM_C plusAvailEnv acc (moduleName m)
659 (unitAvailEnv (mk_avail n))
660 add_name (GRE n other_prov _) acc = acc
662 mk_avail n = case lookupNameEnv avail_env n of
663 Just (AvailTC m _) | n==m -> AvailTC n [n]
664 | otherwise -> AvailTC m [n,m]
665 Just avail -> Avail n
666 Nothing -> pprPanic "mk_avail" (ppr n)
669 | m `elemFM` acc = acc -- We import something already
670 | otherwise = addToFM acc m emptyAvailEnv
671 -- Add an empty collection of imports for a module
672 -- from which we have sucked only instance decls
674 direct_import_mods :: [ModuleName]
675 direct_import_mods = nub [m | ImportDecl m _ _ _ _ _ <- imports]
677 -- unused_imp_mods are the directly-imported modules
678 -- that are not mentioned in minimal_imports
679 unused_imp_mods = [m | m <- direct_import_mods,
680 not (maybeToBool (lookupFM minimal_imports m)),
683 module_unused :: Module -> Bool
684 module_unused mod = moduleName mod `elem` unused_imp_mods
687 -- ToDo: deal with original imports with 'qualified' and 'as M' clauses
688 printMinimalImports :: Module -- This module
690 -> FiniteMap ModuleName AvailEnv -- Minimal imports
692 printMinimalImports this_mod unqual imps
693 = ifOptRn Opt_D_dump_minimal_imports $
695 mapRn to_ies (fmToList imps) `thenRn` \ mod_ies ->
696 ioToRnM (do { h <- openFile filename WriteMode ;
697 printForUser h unqual (vcat (map ppr_mod_ie mod_ies))
701 filename = moduleNameUserString (moduleName this_mod) ++ ".imports"
702 ppr_mod_ie (mod_name, ies)
703 | mod_name == pRELUDE_Name
706 = ptext SLIT("import") <+> ppr mod_name <>
707 parens (fsep (punctuate comma (map ppr ies)))
709 to_ies (mod, avail_env) = mapRn to_ie (availEnvElts avail_env) `thenRn` \ ies ->
712 to_ie :: AvailInfo -> RnMG (IE Name)
713 -- The main trick here is that if we're importing all the constructors
714 -- we want to say "T(..)", but if we're importing only a subset we want
715 -- to say "T(A,B,C)". So we have to find out what the module exports.
716 to_ie (Avail n) = returnRn (IEVar n)
717 to_ie (AvailTC n [m]) = ASSERT( n==m )
718 returnRn (IEThingAbs n)
720 = loadInterface (text "Compute minimal imports from" <+> ppr n_mod) n_mod ImportBySystem `thenRn` \ iface ->
721 case [xs | (m,as) <- mi_exports iface,
725 [xs] | all (`elem` ns) xs -> returnRn (IEThingAll n)
726 | otherwise -> returnRn (IEThingWith n (filter (/= n) ns))
727 other -> pprTrace "to_ie" (ppr n <+> ppr (nameModule n) <+> ppr other) $
730 n_mod = moduleName (nameModule n)
732 rnDump :: [RenamedHsDecl] -- Renamed imported decls
733 -> [RenamedHsDecl] -- Renamed local decls
735 rnDump imp_decls local_decls
736 = doptRn Opt_D_dump_rn_trace `thenRn` \ dump_rn_trace ->
737 doptRn Opt_D_dump_rn_stats `thenRn` \ dump_rn_stats ->
738 doptRn Opt_D_dump_rn `thenRn` \ dump_rn ->
739 getIfacesRn `thenRn` \ ifaces ->
741 ioToRnM (do { dumpIfSet (dump_rn_trace || dump_rn_stats || dump_rn)
743 (getRnStats imp_decls ifaces) ;
745 dumpIfSet dump_rn "Renamer:"
746 (vcat (map ppr (local_decls ++ imp_decls)))
753 %*********************************************************
755 \subsection{Statistics}
757 %*********************************************************
760 getRnStats :: [RenamedHsDecl] -> Ifaces -> SDoc
761 getRnStats imported_decls ifaces
762 = hcat [text "Renamer stats: ", stats]
764 n_mods = length [() | _ <- moduleEnvElts (iPIT ifaces)]
765 -- This is really only right for a one-shot compile
767 (decls_map, n_decls_slurped) = iDecls ifaces
769 n_decls_left = length [decl | (avail, True, (_,decl)) <- nameEnvElts decls_map
770 -- Data, newtype, and class decls are in the decls_fm
771 -- under multiple names; the tycon/class, and each
772 -- constructor/class op too.
773 -- The 'True' selects just the 'main' decl
776 (insts_left, n_insts_slurped) = iInsts ifaces
777 n_insts_left = length (bagToList insts_left)
779 (rules_left, n_rules_slurped) = iRules ifaces
780 n_rules_left = length (bagToList rules_left)
783 [int n_mods <+> text "interfaces read",
784 hsep [ int n_decls_slurped, text "type/class/variable imported, out of",
785 int (n_decls_slurped + n_decls_left), text "read"],
786 hsep [ int n_insts_slurped, text "instance decls imported, out of",
787 int (n_insts_slurped + n_insts_left), text "read"],
788 hsep [ int n_rules_slurped, text "rule decls imported, out of",
789 int (n_rules_slurped + n_rules_left), text "read"]
794 %************************************************************************
796 \subsection{Errors and warnings}
798 %************************************************************************
801 dupFixityDecl rdr_name loc1 loc2
802 = vcat [ptext SLIT("Multiple fixity declarations for") <+> quotes (ppr rdr_name),
803 ptext SLIT("at ") <+> ppr loc1,
804 ptext SLIT("and") <+> ppr loc2]
807 = sep [ptext SLIT("Illegal deprecation when whole module is deprecated"),