2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
5 \section[TcModule]{Typechecking a whole module}
9 -- The above warning supression flag is a temporary kludge.
10 -- While working on this module you are encouraged to remove it and fix
11 -- any warnings in the module. See
12 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
17 tcRnStmt, tcRnExpr, tcRnType,
30 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
59 import TcUnify ( withBox )
93 import {- Kind parts of -} Type
95 import Foreign.Ptr( Ptr )
104 import Data.Maybe ( isJust )
110 %************************************************************************
112 Typecheck and rename a module
114 %************************************************************************
120 -> Bool -- True <=> save renamed syntax
121 -> Located (HsModule RdrName)
122 -> IO (Messages, Maybe TcGblEnv)
124 tcRnModule hsc_env hsc_src save_rn_syntax
125 (L loc (HsModule maybe_mod export_ies
126 import_decls local_decls mod_deprec
127 module_info maybe_doc))
128 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
130 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
131 this_mod = case maybe_mod of
132 Nothing -> mAIN -- 'module M where' is omitted
133 Just (L _ mod) -> mkModule this_pkg mod } ;
136 initTc hsc_env hsc_src save_rn_syntax this_mod $
138 do { -- Deal with imports;
139 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
140 setGblEnv tcg_env $ do {
142 -- Load the hi-boot interface for this module, if any
143 -- We do this now so that the boot_names can be passed
144 -- to tcTyAndClassDecls, because the boot_names are
145 -- automatically considered to be loop breakers
147 -- Do this *after* tcRnImports, so that we know whether
148 -- a module that we import imports us; and hence whether to
149 -- look for a hi-boot file
150 boot_iface <- tcHiBootIface hsc_src this_mod ;
152 -- Rename and type check the declarations
153 traceRn (text "rn1a") ;
154 tcg_env <- if isHsBoot hsc_src then
155 tcRnHsBootDecls local_decls
157 tcRnSrcDecls boot_iface local_decls ;
158 setGblEnv tcg_env $ do {
160 -- Report the use of any deprecated things
161 -- We do this *before* processsing the export list so
162 -- that we don't bleat about re-exporting a deprecated
163 -- thing (especially via 'module Foo' export item)
164 -- That is, only uses in the *body* of the module are complained about
165 traceRn (text "rn3") ;
166 failIfErrsM ; -- finishDeprecations crashes sometimes
167 -- as a result of typechecker repairs (e.g. unboundNames)
168 tcg_env <- finishDeprecations (hsc_dflags hsc_env) mod_deprec tcg_env ;
170 -- Process the export list
171 traceRn (text "rn4a: before exports");
172 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
173 traceRn (text "rn4b: after exportss") ;
175 -- Compare the hi-boot iface (if any) with the real thing
176 -- Must be done after processing the exports
177 tcg_env <- checkHiBootIface tcg_env boot_iface ;
179 -- Make the new type env available to stuff slurped from interface files
180 -- Must do this after checkHiBootIface, because the latter might add new
181 -- bindings for boot_dfuns, which may be mentioned in imported unfoldings
182 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
184 -- Rename the Haddock documentation
185 tcg_env <- rnHaddock module_info maybe_doc tcg_env ;
187 -- Report unused names
188 reportUnusedNames export_ies tcg_env ;
190 -- Dump output and return
197 %************************************************************************
201 %************************************************************************
204 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
205 tcRnImports hsc_env this_mod import_decls
206 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
208 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
209 ; dep_mods = imp_dep_mods imports
211 -- We want instance declarations from all home-package
212 -- modules below this one, including boot modules, except
213 -- ourselves. The 'except ourselves' is so that we don't
214 -- get the instances from this module's hs-boot file
215 ; want_instances :: ModuleName -> Bool
216 ; want_instances mod = mod `elemUFM` dep_mods
217 && mod /= moduleName this_mod
218 ; (home_insts, home_fam_insts) = hptInstances hsc_env
222 -- Record boot-file info in the EPS, so that it's
223 -- visible to loadHiBootInterface in tcRnSrcDecls,
224 -- and any other incrementally-performed imports
225 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
227 -- Update the gbl env
228 ; updGblEnv ( \ gbl ->
230 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
231 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
232 tcg_rn_imports = fmap (const rn_imports) (tcg_rn_imports gbl),
233 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
234 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
239 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
240 -- Fail if there are any errors so far
241 -- The error printing (if needed) takes advantage
242 -- of the tcg_env we have now set
243 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
246 -- Load any orphan-module and family instance-module
247 -- interfaces, so that their rules and instance decls will be
249 ; loadOrphanModules (imp_orphs imports) False
250 ; loadOrphanModules (imp_finsts imports) True
252 -- Check type-familily consistency
253 ; traceRn (text "rn1: checking family instance consistency")
254 ; let { dir_imp_mods = map (\ (mod, _) -> mod)
258 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
264 %************************************************************************
266 Type-checking external-core modules
268 %************************************************************************
271 tcRnExtCore :: HscEnv
273 -> IO (Messages, Maybe ModGuts)
274 -- Nothing => some error occurred
276 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
277 -- The decls are IfaceDecls; all names are original names
278 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
280 initTc hsc_env ExtCoreFile False this_mod $ do {
282 let { ldecls = map noLoc decls } ;
284 -- bring the type and class decls into scope
285 -- ToDo: check that this doesn't need to extract the val binds.
286 -- It seems that only the type and class decls need to be in scope below because
287 -- (a) tcTyAndClassDecls doesn't need the val binds, and
288 -- (b) tcExtCoreBindings doesn't need anything
289 -- (in fact, it might not even need to be in the scope of
290 -- this tcg_env at all)
291 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
292 tc_envs <- extendGlobalRdrEnvRn False avails
293 emptyFsEnv {- no fixity decls -} ;
295 setEnvs tc_envs $ do {
297 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
299 -- Dump trace of renaming part
300 rnDump (ppr rn_decls) ;
302 -- Typecheck them all together so that
303 -- any mutually recursive types are done right
304 tcg_env <- tcTyAndClassDecls emptyModDetails rn_decls ;
305 -- Make the new type env available to stuff slurped from interface files
307 setGblEnv tcg_env $ do {
309 -- Now the core bindings
310 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
314 bndrs = bindersOfBinds core_binds ;
315 my_exports = map (Avail . idName) bndrs ;
316 -- ToDo: export the data types also?
318 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
320 mod_guts = ModGuts { mg_module = this_mod,
322 mg_used_names = emptyNameSet, -- ToDo: compute usage
323 mg_dir_imps = emptyModuleEnv, -- ??
324 mg_deps = noDependencies, -- ??
325 mg_exports = my_exports,
326 mg_types = final_type_env,
327 mg_insts = tcg_insts tcg_env,
328 mg_fam_insts = tcg_fam_insts tcg_env,
329 mg_inst_env = tcg_inst_env tcg_env,
330 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
332 mg_binds = core_binds,
335 mg_rdr_env = emptyGlobalRdrEnv,
336 mg_fix_env = emptyFixityEnv,
337 mg_deprecs = NoDeprecs,
338 mg_foreign = NoStubs,
339 mg_hpc_info = emptyHpcInfo False,
340 mg_modBreaks = emptyModBreaks,
341 mg_vect_info = noVectInfo
344 tcCoreDump mod_guts ;
349 mkFakeGroup decls -- Rather clumsy; lots of unused fields
350 = emptyRdrGroup { hs_tyclds = decls }
354 %************************************************************************
356 Type-checking the top level of a module
358 %************************************************************************
361 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
362 -- Returns the variables free in the decls
363 -- Reason: solely to report unused imports and bindings
364 tcRnSrcDecls boot_iface decls
365 = do { -- Do all the declarations
366 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
368 -- Finish simplifying class constraints
370 -- tcSimplifyTop deals with constant or ambiguous InstIds.
371 -- How could there be ambiguous ones? They can only arise if a
372 -- top-level decl falls under the monomorphism restriction
373 -- and no subsequent decl instantiates its type.
375 -- We do this after checkMain, so that we use the type info
376 -- thaat checkMain adds
378 -- We do it with both global and local env in scope:
379 -- * the global env exposes the instances to tcSimplifyTop
380 -- * the local env exposes the local Ids to tcSimplifyTop,
381 -- so that we get better error messages (monomorphism restriction)
382 traceTc (text "Tc8") ;
383 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
385 -- Backsubstitution. This must be done last.
386 -- Even tcSimplifyTop may do some unification.
387 traceTc (text "Tc9") ;
388 let { (tcg_env, _) = tc_envs
389 ; TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
390 tcg_rules = rules, tcg_fords = fords } = tcg_env
391 ; all_binds = binds `unionBags` inst_binds } ;
393 failIfErrsM ; -- Don't zonk if there have been errors
394 -- It's a waste of time; and we may get debug warnings
395 -- about strangely-typed TyCons!
397 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
399 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
400 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
403 tcg_fords = fords' } } ;
405 return (tcg_env' { tcg_binds = tcg_binds tcg_env' })
408 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
409 -- Loops around dealing with each top level inter-splice group
410 -- in turn, until it's dealt with the entire module
411 tc_rn_src_decls boot_details ds
412 = do { let { (first_group, group_tail) = findSplice ds } ;
413 -- If ds is [] we get ([], Nothing)
415 -- Deal with decls up to, but not including, the first splice
416 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
417 -- rnTopSrcDecls fails if there are any errors
419 (tcg_env, tcl_env) <- setGblEnv tcg_env $
420 tcTopSrcDecls boot_details rn_decls ;
422 -- If there is no splice, we're nearly done
423 setEnvs (tcg_env, tcl_env) $
425 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
426 return (tcg_env, tcl_env)
429 -- If there's a splice, we must carry on
430 Just (SpliceDecl splice_expr, rest_ds) -> do {
432 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
435 -- Rename the splice expression, and get its supporting decls
436 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
437 -- checkNoErrs: don't typecheck if renaming failed
438 rnDump (ppr rn_splice_expr) ;
440 -- Execute the splice
441 spliced_decls <- tcSpliceDecls rn_splice_expr ;
443 -- Glue them on the front of the remaining decls and loop
444 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
445 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
450 %************************************************************************
452 Compiling hs-boot source files, and
453 comparing the hi-boot interface with the real thing
455 %************************************************************************
458 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
459 tcRnHsBootDecls decls
460 = do { let { (first_group, group_tail) = findSplice decls }
463 Just stuff -> spliceInHsBootErr stuff
466 -- Rename the declarations
467 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
468 ; setGblEnv tcg_env $ do {
470 -- Todo: check no foreign decls, no rules, no default decls
472 -- Typecheck type/class decls
473 ; traceTc (text "Tc2")
474 ; let tycl_decls = hs_tyclds rn_group
475 ; tcg_env <- tcTyAndClassDecls emptyModDetails tycl_decls
476 ; setGblEnv tcg_env $ do {
478 -- Typecheck instance decls
479 ; traceTc (text "Tc3")
480 ; (tcg_env, inst_infos, _deriv_binds)
481 <- tcInstDecls1 tycl_decls (hs_instds rn_group) (hs_derivds rn_group)
482 ; setGblEnv tcg_env $ do {
484 -- Typecheck value declarations
485 ; traceTc (text "Tc5")
486 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
489 -- No simplification or zonking to do
490 ; traceTc (text "Tc7a")
491 ; gbl_env <- getGblEnv
493 -- Make the final type-env
494 -- Include the dfun_ids so that their type sigs
495 -- are written into the interface file
496 ; let { type_env0 = tcg_type_env gbl_env
497 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
498 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
499 ; dfun_ids = map iDFunId inst_infos }
500 ; return (gbl_env { tcg_type_env = type_env2 })
503 spliceInHsBootErr (SpliceDecl (L loc _), _)
504 = addErrAt loc (ptext (sLit "Splices are not allowed in hs-boot files"))
507 Once we've typechecked the body of the module, we want to compare what
508 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
511 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
512 -- Compare the hi-boot file for this module (if there is one)
513 -- with the type environment we've just come up with
514 -- In the common case where there is no hi-boot file, the list
515 -- of boot_names is empty.
517 -- The bindings we return give bindings for the dfuns defined in the
518 -- hs-boot file, such as $fbEqT = $fEqT
521 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
522 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
523 tcg_type_env = local_type_env, tcg_exports = local_exports })
524 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
525 md_types = boot_type_env, md_exports = boot_exports })
526 | isHsBoot hs_src -- Current module is already a hs-boot file!
530 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
533 -- Check the exports of the boot module, one by one
534 ; mapM_ check_export boot_exports
536 -- Check instance declarations
537 ; mb_dfun_prs <- mapM check_inst boot_insts
538 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds,
539 tcg_type_env = extendTypeEnvWithIds local_type_env boot_dfuns }
540 dfun_prs = catMaybes mb_dfun_prs
541 boot_dfuns = map fst dfun_prs
542 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
543 | (boot_dfun, dfun) <- dfun_prs ]
545 -- Check for no family instances
546 ; unless (null boot_fam_insts) $
547 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
548 "instances in boot files yet...")
549 -- FIXME: Why? The actual comparison is not hard, but what would
550 -- be the equivalent to the dfun bindings returned for class
551 -- instances? We can't easily equate tycons...
555 check_export boot_avail -- boot_avail is exported by the boot iface
556 | name `elem` dfun_names = return ()
557 | isWiredInName name = return () -- No checking for wired-in names. In particular,
558 -- 'error' is handled by a rather gross hack
559 -- (see comments in GHC.Err.hs-boot)
561 -- Check that the actual module exports the same thing
562 | not (null missing_names)
563 = addErrTc (missingBootThing (head missing_names) "exported by")
565 -- If the boot module does not *define* the thing, we are done
566 -- (it simply re-exports it, and names match, so nothing further to do)
567 | isNothing mb_boot_thing = return ()
569 -- Check that the actual module also defines the thing, and
570 -- then compare the definitions
571 | Just real_thing <- lookupTypeEnv local_type_env name
572 = do { let boot_decl = tyThingToIfaceDecl (fromJust mb_boot_thing)
573 real_decl = tyThingToIfaceDecl real_thing
574 ; checkTc (checkBootDecl boot_decl real_decl)
575 (bootMisMatch real_thing boot_decl real_decl) }
576 -- The easiest way to check compatibility is to convert to
577 -- iface syntax, where we already have good comparison functions
580 = addErrTc (missingBootThing name "defined in")
582 name = availName boot_avail
583 mb_boot_thing = lookupTypeEnv boot_type_env name
584 missing_names = case lookupNameEnv local_export_env name of
586 Just avail -> availNames boot_avail `minusList` availNames avail
588 dfun_names = map getName boot_insts
590 local_export_env :: NameEnv AvailInfo
591 local_export_env = availsToNameEnv local_exports
593 check_inst :: Instance -> TcM (Maybe (Id, Id))
594 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
596 = case [dfun | inst <- local_insts,
597 let dfun = instanceDFunId inst,
598 idType dfun `tcEqType` boot_inst_ty ] of
599 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
600 (dfun:_) -> return (Just (local_boot_dfun, dfun))
602 boot_dfun = instanceDFunId boot_inst
603 boot_inst_ty = idType boot_dfun
604 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
608 missingBootThing thing what
609 = ppr thing <+> ptext (sLit "is exported by the hs-boot file, but not")
610 <+> text what <+> ptext (sLit "the module")
612 bootMisMatch thing boot_decl real_decl
613 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
614 ptext (sLit "Main module:") <+> ppr real_decl,
615 ptext (sLit "Boot file: ") <+> ppr boot_decl]
619 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
623 %************************************************************************
625 Type-checking the top level of a module
627 %************************************************************************
629 tcRnGroup takes a bunch of top-level source-code declarations, and
631 * gets supporting declarations from interface files
634 * and augments the TcGblEnv with the results
636 In Template Haskell it may be called repeatedly for each group of
637 declarations. It expects there to be an incoming TcGblEnv in the
638 monad; it augments it and returns the new TcGblEnv.
641 ------------------------------------------------
642 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
643 -- Fails if there are any errors
645 = do { -- Rename the source decls (with no shadowing; error on duplicates)
646 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls False group ;
648 -- save the renamed syntax, if we want it
650 | Just grp <- tcg_rn_decls tcg_env
651 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
655 -- Dump trace of renaming part
656 rnDump (ppr rn_decls) ;
658 return (tcg_env', rn_decls)
661 ------------------------------------------------
662 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
663 tcTopSrcDecls boot_details
664 (HsGroup { hs_tyclds = tycl_decls,
665 hs_instds = inst_decls,
666 hs_derivds = deriv_decls,
667 hs_fords = foreign_decls,
668 hs_defds = default_decls,
669 hs_ruleds = rule_decls,
670 hs_valds = val_binds })
671 = do { -- Type-check the type and class decls, and all imported decls
672 -- The latter come in via tycl_decls
673 traceTc (text "Tc2") ;
675 tcg_env <- tcTyAndClassDecls boot_details tycl_decls ;
676 -- If there are any errors, tcTyAndClassDecls fails here
678 -- Make these type and class decls available to stuff slurped from interface files
679 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
682 setGblEnv tcg_env $ do {
683 -- Source-language instances, including derivings,
684 -- and import the supporting declarations
685 traceTc (text "Tc3") ;
686 (tcg_env, inst_infos, deriv_binds)
687 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
688 setGblEnv tcg_env $ do {
690 -- Foreign import declarations next. No zonking necessary
691 -- here; we can tuck them straight into the global environment.
692 traceTc (text "Tc4") ;
693 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
694 tcExtendGlobalValEnv fi_ids $ do {
696 -- Default declarations
697 traceTc (text "Tc4a") ;
698 default_tys <- tcDefaults default_decls ;
699 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
701 -- Value declarations next
702 -- We also typecheck any extra binds that came out
703 -- of the "deriving" process (deriv_binds)
704 traceTc (text "Tc5") ;
705 (tc_val_binds, tcl_env) <- tcTopBinds val_binds ;
706 setLclTypeEnv tcl_env $ do {
708 -- Now GHC-generated derived bindings and generics.
709 -- Do not generate warnings from compiler-generated code.
710 (tc_deriv_binds, tcl_env) <- discardWarnings $
711 tcTopBinds deriv_binds ;
713 -- Second pass over class and instance declarations,
714 traceTc (text "Tc6") ;
715 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $ tcInstDecls2 tycl_decls inst_infos ;
716 showLIE (text "after instDecls2") ;
719 -- They need to be zonked, so we return them
720 traceTc (text "Tc7") ;
721 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
724 rules <- tcRules rule_decls ;
727 traceTc (text "Tc7a") ;
728 tcg_env <- getGblEnv ;
729 let { all_binds = tc_val_binds `unionBags`
730 tc_deriv_binds `unionBags`
731 inst_binds `unionBags`
734 -- Extend the GblEnv with the (as yet un-zonked)
735 -- bindings, rules, foreign decls
736 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
737 tcg_rules = tcg_rules tcg_env ++ rules,
738 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
739 return (tcg_env', tcl_env)
744 %************************************************************************
748 %************************************************************************
751 checkMain :: TcM TcGblEnv
752 -- If we are in module Main, check that 'main' is defined.
754 = do { tcg_env <- getGblEnv ;
756 check_main dflags tcg_env
759 check_main dflags tcg_env
761 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
765 = do { mb_main <- lookupSrcOcc_maybe main_fn
766 -- Check that 'main' is in scope
767 -- It might be imported from another module!
769 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
774 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
775 ; let loc = srcLocSpan (getSrcLoc main_name)
776 ; ioTyCon <- tcLookupTyCon ioTyConName
777 ; (main_expr, res_ty)
778 <- addErrCtxt mainCtxt $
779 withBox liftedTypeKind $ \res_ty ->
780 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
782 -- See Note [Root-main Id]
783 -- Construct the binding
784 -- :Main.main :: IO res_ty = runMainIO res_ty main
785 ; run_main_id <- tcLookupId runMainIOName
786 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
787 (mkVarOccFS (fsLit "main"))
788 (getSrcSpan main_name)
789 ; root_main_id = Id.mkExportedLocalId root_main_name
790 (mkTyConApp ioTyCon [res_ty])
791 ; co = mkWpTyApps [res_ty]
792 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
793 ; main_bind = noLoc (VarBind root_main_id rhs) }
795 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
797 tcg_dus = tcg_dus tcg_env
798 `plusDU` usesOnly (unitFV main_name)
799 -- Record the use of 'main', so that we don't
800 -- complain about it being defined but not used
804 mod = tcg_mod tcg_env
805 main_mod = mainModIs dflags
806 main_is_flag = mainFunIs dflags
808 main_fn = case main_is_flag of
809 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
810 Nothing -> main_RDR_Unqual
812 complain_no_main | ghcLink dflags == LinkInMemory = return ()
813 | otherwise = failWithTc noMainMsg
814 -- In interactive mode, don't worry about the absence of 'main'
815 -- In other modes, fail altogether, so that we don't go on
816 -- and complain a second time when processing the export list.
818 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
819 noMainMsg = ptext (sLit "The") <+> pp_main_fn
820 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
821 pp_main_fn | isJust main_is_flag = ptext (sLit "main function") <+> quotes (ppr main_fn)
822 | otherwise = ptext (sLit "function") <+> quotes (ppr main_fn)
827 The function that the RTS invokes is always :Main.main, which we call
828 root_main_id. (Because GHC allows the user to have a module not
829 called Main as the main module, we can't rely on the main function
830 being called "Main.main". That's why root_main_id has a fixed module
833 This is unusual: it's a LocalId whose Name has a Module from another
834 module. Tiresomely, we must filter it out again in MkIface, les we
835 get two defns for 'main' in the interface file!
838 %*********************************************************
842 %*********************************************************
846 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
847 setInteractiveContext hsc_env icxt thing_inside
848 = let -- Initialise the tcg_inst_env with instances from all home modules.
849 -- This mimics the more selective call to hptInstances in tcRnModule.
850 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
852 updGblEnv (\env -> env {
853 tcg_rdr_env = ic_rn_gbl_env icxt,
854 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
855 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
859 tcExtendGhciEnv (ic_tmp_ids icxt) $
860 -- tcExtendGhciEnv does lots:
861 -- - it extends the local type env (tcl_env) with the given Ids,
862 -- - it extends the local rdr env (tcl_rdr) with the Names from
864 -- - it adds the free tyvars of the Ids to the tcl_tyvars
867 -- later ids in ic_tmp_ids must shadow earlier ones with the same
868 -- OccName, and tcExtendIdEnv implements this behaviour.
870 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
877 -> InteractiveContext
879 -> IO (Maybe ([Id], LHsExpr Id))
880 -- The returned [Id] is the list of new Ids bound by
881 -- this statement. It can be used to extend the
882 -- InteractiveContext via extendInteractiveContext.
884 -- The returned TypecheckedHsExpr is of type IO [ () ],
885 -- a list of the bound values, coerced to ().
887 tcRnStmt hsc_env ictxt rdr_stmt
888 = initTcPrintErrors hsc_env iNTERACTIVE $
889 setInteractiveContext hsc_env ictxt $ do {
891 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
892 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
893 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
895 rnDump (ppr rn_stmt) ;
897 -- The real work is done here
898 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
899 zonked_expr <- zonkTopLExpr tc_expr ;
900 zonked_ids <- zonkTopBndrs bound_ids ;
902 -- None of the Ids should be of unboxed type, because we
903 -- cast them all to HValues in the end!
904 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
906 traceTc (text "tcs 1") ;
907 let { global_ids = map globaliseAndTidy zonked_ids } ;
909 {- ---------------------------------------------
910 At one stage I removed any shadowed bindings from the type_env;
911 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
912 However, with Template Haskell they aren't necessarily inaccessible. Consider this
914 Prelude> let f n = n * 2 :: Int
915 Prelude> fName <- runQ [| f |]
916 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
918 Prelude> let f n = n * 3 :: Int
919 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
920 In the last line we use 'fName', which resolves to the *first* 'f'
921 in scope. If we delete it from the type env, GHCi crashes because
922 it doesn't expect that.
924 Hence this code is commented out
926 -------------------------------------------------- -}
928 dumpOptTcRn Opt_D_dump_tc
929 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
930 text "Typechecked expr" <+> ppr zonked_expr]) ;
932 return (global_ids, zonked_expr)
935 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
936 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
938 globaliseAndTidy :: Id -> Id
939 globaliseAndTidy id -- Note [Interactively-bound Ids in GHCi]
940 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
942 tidy_type = tidyTopType (idType id)
945 Note [Interactively-bound Ids in GHCi]
946 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
947 The Ids bound by previous Stmts in Template Haskell are currently
949 b) with an Internal Name (not External)
952 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
953 compile an expression using these ids later, the byte code
954 generator will consider the occurrences to be free rather than
957 (b) They retain their Internal names becuase we don't have a suitable
958 Module to name them with. We could revisit this choice.
960 (c) Their types are tidied. This is important, because :info may ask
961 to look at them, and :info expects the things it looks up to have
965 --------------------------------------------------------------------------
966 Typechecking Stmts in GHCi
968 Here is the grand plan, implemented in tcUserStmt
970 What you type The IO [HValue] that hscStmt returns
971 ------------- ------------------------------------
972 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
975 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
978 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
979 [NB: result not printed] bindings: [it]
981 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
982 result showable) bindings: [it]
984 expr (of non-IO type,
985 result not showable) ==> error
989 ---------------------------
990 type PlanResult = ([Id], LHsExpr Id)
991 type Plan = TcM PlanResult
993 runPlans :: [Plan] -> TcM PlanResult
994 -- Try the plans in order. If one fails (by raising an exn), try the next.
995 -- If one succeeds, take it.
996 runPlans [] = panic "runPlans"
998 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1000 --------------------
1001 mkPlan :: LStmt Name -> TcM PlanResult
1002 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1003 = do { uniq <- newUnique -- is treated very specially
1004 ; let fresh_it = itName uniq
1005 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1006 matches = [mkMatch [] expr emptyLocalBinds]
1007 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1008 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1009 (HsVar bindIOName) noSyntaxExpr
1010 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1011 (HsVar thenIOName) placeHolderType
1014 -- [it <- e; print it] but not if it::()
1016 -- [let it = e; print it]
1017 ; runPlans [ -- Plan A
1018 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1019 ; it_ty <- zonkTcType (idType it_id)
1020 ; when (isUnitTy it_ty) failM
1023 -- Plan B; a naked bind statment
1024 tcGhciStmts [bind_stmt],
1026 -- Plan C; check that the let-binding is typeable all by itself.
1027 -- If not, fail; if so, try to print it.
1028 -- The two-step process avoids getting two errors: one from
1029 -- the expression itself, and one from the 'print it' part
1030 -- This two-step story is very clunky, alas
1031 do { checkNoErrs (tcGhciStmts [let_stmt])
1032 --- checkNoErrs defeats the error recovery of let-bindings
1033 ; tcGhciStmts [let_stmt, print_it] }
1036 mkPlan stmt@(L loc (BindStmt {}))
1037 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1038 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1039 (HsVar thenIOName) placeHolderType
1041 ; print_bind_result <- doptM Opt_PrintBindResult
1042 ; let print_plan = do
1043 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1044 ; v_ty <- zonkTcType (idType v_id)
1045 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1049 -- [stmt; print v] but not if v::()
1051 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1052 [tcGhciStmts [stmt]])
1056 = tcGhciStmts [stmt]
1058 ---------------------------
1059 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1061 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1062 ret_id <- tcLookupId returnIOName ; -- return @ IO
1064 ret_ty = mkListTy unitTy ;
1065 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1066 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1068 names = map unLoc (collectLStmtsBinders stmts) ;
1070 -- mk_return builds the expression
1071 -- returnIO @ [()] [coerce () x, .., coerce () z]
1073 -- Despite the inconvenience of building the type applications etc,
1074 -- this *has* to be done in type-annotated post-typecheck form
1075 -- because we are going to return a list of *polymorphic* values
1076 -- coerced to type (). If we built a *source* stmt
1077 -- return [coerce x, ..., coerce z]
1078 -- then the type checker would instantiate x..z, and we wouldn't
1079 -- get their *polymorphic* values. (And we'd get ambiguity errs
1080 -- if they were overloaded, since they aren't applied to anything.)
1081 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1082 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1083 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1087 -- OK, we're ready to typecheck the stmts
1088 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1089 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1090 mapM tcLookupId names ;
1091 -- Look up the names right in the middle,
1092 -- where they will all be in scope
1094 -- Simplify the context
1095 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1096 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1097 -- checkNoErrs ensures that the plan fails if context redn fails
1099 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1100 return (ids, mkHsDictLet const_binds $
1101 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1106 tcRnExpr just finds the type of an expression
1110 -> InteractiveContext
1113 tcRnExpr hsc_env ictxt rdr_expr
1114 = initTcPrintErrors hsc_env iNTERACTIVE $
1115 setInteractiveContext hsc_env ictxt $ do {
1117 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1120 -- Now typecheck the expression;
1121 -- it might have a rank-2 type (e.g. :t runST)
1122 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1123 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1124 tcSimplifyInteractive lie_top ;
1126 let { all_expr_ty = mkForAllTys qtvs $
1127 mkFunTys (map (idType . instToId) dict_insts) $
1129 zonkTcType all_expr_ty
1132 smpl_doc = ptext (sLit "main expression")
1135 tcRnType just finds the kind of a type
1139 -> InteractiveContext
1142 tcRnType hsc_env ictxt rdr_type
1143 = initTcPrintErrors hsc_env iNTERACTIVE $
1144 setInteractiveContext hsc_env ictxt $ do {
1146 rn_type <- rnLHsType doc rdr_type ;
1149 -- Now kind-check the type
1150 (ty', kind) <- kcHsType rn_type ;
1154 doc = ptext (sLit "In GHCi input")
1160 %************************************************************************
1162 More GHCi stuff, to do with browsing and getting info
1164 %************************************************************************
1168 -- ASSUMES that the module is either in the HomePackageTable or is
1169 -- a package module with an interface on disk. If neither of these is
1170 -- true, then the result will be an error indicating the interface
1171 -- could not be found.
1172 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1173 getModuleExports hsc_env mod
1176 checkMods = ic_toplev_scope ic ++ ic_exports ic
1178 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1180 -- Get the export avail info and also load all orphan and family-instance
1181 -- modules. Finally, check that the family instances of all modules in the
1182 -- interactive context are consistent (these modules are in the second
1184 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1185 tcGetModuleExports mod directlyImpMods
1186 = do { let doc = ptext (sLit "context for compiling statements")
1187 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1189 -- Load any orphan-module and family instance-module
1190 -- interfaces, so their instances are visible.
1191 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1192 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1194 -- Check that the family instances of all directly loaded
1195 -- modules are consistent.
1196 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1198 ; ifaceExportNames (mi_exports iface)
1201 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1202 tcRnLookupRdrName hsc_env rdr_name
1203 = initTcPrintErrors hsc_env iNTERACTIVE $
1204 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1205 lookup_rdr_name rdr_name
1207 lookup_rdr_name rdr_name = do {
1208 -- If the identifier is a constructor (begins with an
1209 -- upper-case letter), then we need to consider both
1210 -- constructor and type class identifiers.
1211 let { rdr_names = dataTcOccs rdr_name } ;
1213 -- results :: [Either Messages Name]
1214 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1216 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1217 -- The successful lookups will be (Just name)
1218 let { (warns_s, good_names) = unzip [ (msgs, name)
1219 | (msgs, Just name) <- results] ;
1220 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1222 -- Fail if nothing good happened, else add warnings
1223 if null good_names then
1224 -- No lookup succeeded, so
1225 -- pick the first error message and report it
1226 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1227 -- while the other is "X is not in scope",
1228 -- we definitely want the former; but we might pick the latter
1229 do { addMessages (head errs_s) ; failM }
1230 else -- Add deprecation warnings
1231 mapM_ addMessages warns_s ;
1236 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1237 tcRnLookupName hsc_env name
1238 = initTcPrintErrors hsc_env iNTERACTIVE $
1239 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1240 tcRnLookupName' name
1242 -- To look up a name we have to look in the local environment (tcl_lcl)
1243 -- as well as the global environment, which is what tcLookup does.
1244 -- But we also want a TyThing, so we have to convert:
1246 tcRnLookupName' :: Name -> TcRn TyThing
1247 tcRnLookupName' name = do
1248 tcthing <- tcLookup name
1250 AGlobal thing -> return thing
1251 ATcId{tct_id=id} -> return (AnId id)
1252 _ -> panic "tcRnLookupName'"
1254 tcRnGetInfo :: HscEnv
1256 -> IO (Maybe (TyThing, Fixity, [Instance]))
1258 -- Used to implemnent :info in GHCi
1260 -- Look up a RdrName and return all the TyThings it might be
1261 -- A capitalised RdrName is given to us in the DataName namespace,
1262 -- but we want to treat it as *both* a data constructor
1263 -- *and* as a type or class constructor;
1264 -- hence the call to dataTcOccs, and we return up to two results
1265 tcRnGetInfo hsc_env name
1266 = initTcPrintErrors hsc_env iNTERACTIVE $
1267 let ictxt = hsc_IC hsc_env in
1268 setInteractiveContext hsc_env ictxt $ do
1270 -- Load the interface for all unqualified types and classes
1271 -- That way we will find all the instance declarations
1272 -- (Packages have not orphan modules, and we assume that
1273 -- in the home package all relevant modules are loaded.)
1274 loadUnqualIfaces ictxt
1276 thing <- tcRnLookupName' name
1277 fixity <- lookupFixityRn name
1278 ispecs <- lookupInsts thing
1279 return (thing, fixity, ispecs)
1281 lookupInsts :: TyThing -> TcM [Instance]
1282 lookupInsts (AClass cls)
1283 = do { inst_envs <- tcGetInstEnvs
1284 ; return (classInstances inst_envs cls) }
1286 lookupInsts (ATyCon tc)
1287 = do { eps <- getEps -- Load all instances for all classes that are
1288 -- in the type environment (which are all the ones
1289 -- we've seen in any interface file so far)
1290 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1292 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1293 , let dfun = instanceDFunId ispec
1296 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1297 tc_name = tyConName tc
1299 lookupInsts other = return []
1301 loadUnqualIfaces :: InteractiveContext -> TcM ()
1302 -- Load the home module for everything that is in scope unqualified
1303 -- This is so that we can accurately report the instances for
1305 loadUnqualIfaces ictxt
1307 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1309 unqual_mods = [ nameModule name
1310 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1311 let name = gre_name gre,
1312 not (isInternalName name),
1313 isTcOcc (nameOccName name), -- Types and classes only
1314 unQualOK gre ] -- In scope unqualified
1315 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1319 %************************************************************************
1323 %************************************************************************
1326 rnDump :: SDoc -> TcRn ()
1327 -- Dump, with a banner, if -ddump-rn
1328 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1330 tcDump :: TcGblEnv -> TcRn ()
1332 = do { dflags <- getDOpts ;
1334 -- Dump short output if -ddump-types or -ddump-tc
1335 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1336 (dumpTcRn short_dump) ;
1338 -- Dump bindings if -ddump-tc
1339 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1342 short_dump = pprTcGblEnv env
1343 full_dump = pprLHsBinds (tcg_binds env)
1344 -- NB: foreign x-d's have undefined's in their types;
1345 -- hence can't show the tc_fords
1348 = do { dflags <- getDOpts ;
1349 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1350 (dumpTcRn (pprModGuts mod_guts)) ;
1352 -- Dump bindings if -ddump-tc
1353 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1355 full_dump = pprCoreBindings (mg_binds mod_guts)
1357 -- It's unpleasant having both pprModGuts and pprModDetails here
1358 pprTcGblEnv :: TcGblEnv -> SDoc
1359 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1361 tcg_fam_insts = fam_insts,
1363 tcg_imports = imports })
1364 = vcat [ ppr_types insts type_env
1365 , ppr_tycons fam_insts type_env
1367 , ppr_fam_insts fam_insts
1368 , vcat (map ppr rules)
1369 , ppr_gen_tycons (typeEnvTyCons type_env)
1370 , ptext (sLit "Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1371 , ptext (sLit "Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1373 pprModGuts :: ModGuts -> SDoc
1374 pprModGuts (ModGuts { mg_types = type_env,
1376 = vcat [ ppr_types [] type_env,
1379 ppr_types :: [Instance] -> TypeEnv -> SDoc
1380 ppr_types insts type_env
1381 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1383 dfun_ids = map instanceDFunId insts
1384 ids = [id | id <- typeEnvIds type_env, want_sig id]
1385 want_sig id | opt_PprStyle_Debug = True
1386 | otherwise = isLocalId id &&
1387 isExternalName (idName id) &&
1388 not (id `elem` dfun_ids)
1389 -- isLocalId ignores data constructors, records selectors etc.
1390 -- The isExternalName ignores local dictionary and method bindings
1391 -- that the type checker has invented. Top-level user-defined things
1392 -- have External names.
1394 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1395 ppr_tycons fam_insts type_env
1396 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1398 fi_tycons = map famInstTyCon fam_insts
1399 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1400 want_tycon tycon | opt_PprStyle_Debug = True
1401 | otherwise = not (isImplicitTyCon tycon) &&
1402 isExternalName (tyConName tycon) &&
1403 not (tycon `elem` fi_tycons)
1405 ppr_insts :: [Instance] -> SDoc
1406 ppr_insts [] = empty
1407 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1409 ppr_fam_insts :: [FamInst] -> SDoc
1410 ppr_fam_insts [] = empty
1411 ppr_fam_insts fam_insts =
1412 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1414 ppr_sigs :: [Var] -> SDoc
1416 -- Print type signatures; sort by OccName
1417 = vcat (map ppr_sig (sortLe le_sig ids))
1419 le_sig id1 id2 = getOccName id1 <= getOccName id2
1420 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1422 ppr_tydecls :: [TyCon] -> SDoc
1424 -- Print type constructor info; sort by OccName
1425 = vcat (map ppr_tycon (sortLe le_sig tycons))
1427 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1429 | isCoercionTyCon tycon = ptext (sLit "coercion") <+> ppr tycon
1430 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1432 ppr_rules :: [CoreRule] -> SDoc
1433 ppr_rules [] = empty
1434 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1435 nest 4 (pprRules rs),
1438 ppr_gen_tycons [] = empty
1439 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1440 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]