2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
5 \section[TcModule]{Typechecking a whole module}
10 tcRnStmt, tcRnExpr, tcRnType,
22 #include "HsVersions.h"
26 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
89 import {- Kind parts of -} Type
91 import Foreign.Ptr( Ptr )
99 import Control.Monad ( unless )
100 import Data.Maybe ( isJust )
106 %************************************************************************
108 Typecheck and rename a module
110 %************************************************************************
116 -> Bool -- True <=> save renamed syntax
117 -> Located (HsModule RdrName)
118 -> IO (Messages, Maybe TcGblEnv)
120 tcRnModule hsc_env hsc_src save_rn_syntax
121 (L loc (HsModule maybe_mod export_ies
122 import_decls local_decls mod_deprec _
123 module_info maybe_doc))
124 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
126 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
127 this_mod = case maybe_mod of
128 Nothing -> mAIN -- 'module M where' is omitted
129 Just (L _ mod) -> mkModule this_pkg mod } ;
132 initTc hsc_env hsc_src save_rn_syntax this_mod $
134 do { -- Deal with imports;
135 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
136 setGblEnv tcg_env $ do {
138 -- Load the hi-boot interface for this module, if any
139 -- We do this now so that the boot_names can be passed
140 -- to tcTyAndClassDecls, because the boot_names are
141 -- automatically considered to be loop breakers
143 -- Do this *after* tcRnImports, so that we know whether
144 -- a module that we import imports us; and hence whether to
145 -- look for a hi-boot file
146 boot_iface <- tcHiBootIface hsc_src this_mod ;
148 -- Rename and type check the declarations
149 traceRn (text "rn1a") ;
150 tcg_env <- if isHsBoot hsc_src then
151 tcRnHsBootDecls local_decls
153 tcRnSrcDecls boot_iface local_decls ;
154 setGblEnv tcg_env $ do {
156 -- Report the use of any deprecated things
157 -- We do this *before* processsing the export list so
158 -- that we don't bleat about re-exporting a deprecated
159 -- thing (especially via 'module Foo' export item)
160 -- That is, only uses in the *body* of the module are complained about
161 traceRn (text "rn3") ;
162 failIfErrsM ; -- finishDeprecations crashes sometimes
163 -- as a result of typechecker repairs (e.g. unboundNames)
164 tcg_env <- finishDeprecations (hsc_dflags hsc_env) mod_deprec tcg_env ;
166 -- Process the export list
167 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
168 traceRn (text "rn4") ;
170 -- Compare the hi-boot iface (if any) with the real thing
171 -- Must be done after processing the exports
172 tcg_env <- checkHiBootIface tcg_env boot_iface ;
174 -- Make the new type env available to stuff slurped from interface files
175 -- Must do this after checkHiBootIface, because the latter might add new
176 -- bindings for boot_dfuns, which may be mentioned in imported unfoldings
177 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
179 -- Rename the Haddock documentation
180 tcg_env <- rnHaddock module_info maybe_doc tcg_env ;
182 -- Report unused names
183 reportUnusedNames export_ies tcg_env ;
185 -- Dump output and return
192 %************************************************************************
196 %************************************************************************
199 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
200 tcRnImports hsc_env this_mod import_decls
201 = do { (rn_imports, rdr_env, imports) <- rnImports import_decls ;
203 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
204 ; dep_mods = imp_dep_mods imports
206 -- We want instance declarations from all home-package
207 -- modules below this one, including boot modules, except
208 -- ourselves. The 'except ourselves' is so that we don't
209 -- get the instances from this module's hs-boot file
210 ; want_instances :: ModuleName -> Bool
211 ; want_instances mod = mod `elemUFM` dep_mods
212 && mod /= moduleName this_mod
213 ; (home_insts, home_fam_insts) = hptInstances hsc_env
217 -- Record boot-file info in the EPS, so that it's
218 -- visible to loadHiBootInterface in tcRnSrcDecls,
219 -- and any other incrementally-performed imports
220 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
222 -- Update the gbl env
223 ; updGblEnv ( \ gbl ->
225 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
226 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
227 tcg_rn_imports = fmap (const rn_imports) (tcg_rn_imports gbl),
228 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
229 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
233 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
234 -- Fail if there are any errors so far
235 -- The error printing (if needed) takes advantage
236 -- of the tcg_env we have now set
237 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
240 -- Load any orphan-module and family instance-module
241 -- interfaces, so that their rules and instance decls will be
243 ; loadOrphanModules (imp_orphs imports) False
244 ; loadOrphanModules (imp_finsts imports) True
246 -- Check type-familily consistency
247 ; traceRn (text "rn1: checking family instance consistency")
248 ; let { dir_imp_mods = map (\ (mod, _, _) -> mod)
252 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
258 %************************************************************************
260 Type-checking external-core modules
262 %************************************************************************
265 tcRnExtCore :: HscEnv
267 -> IO (Messages, Maybe ModGuts)
268 -- Nothing => some error occurred
270 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
271 -- The decls are IfaceDecls; all names are original names
272 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
274 initTc hsc_env ExtCoreFile False this_mod $ do {
276 let { ldecls = map noLoc decls } ;
278 -- Deal with the type declarations; first bring their stuff
279 -- into scope, then rname them, then type check them
280 tcg_env <- importsFromLocalDecls (mkFakeGroup ldecls) ;
282 setGblEnv tcg_env $ do {
284 rn_decls <- rnTyClDecls ldecls ;
287 -- Dump trace of renaming part
288 rnDump (ppr rn_decls) ;
290 -- Typecheck them all together so that
291 -- any mutually recursive types are done right
292 tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails rn_decls) ;
293 -- Make the new type env available to stuff slurped from interface files
295 setGblEnv tcg_env $ do {
297 -- Now the core bindings
298 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
302 bndrs = bindersOfBinds core_binds ;
303 my_exports = map (Avail . idName) bndrs ;
304 -- ToDo: export the data types also?
306 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
308 mod_guts = ModGuts { mg_module = this_mod,
310 mg_usages = [], -- ToDo: compute usage
311 mg_dir_imps = [], -- ??
312 mg_deps = noDependencies, -- ??
313 mg_exports = my_exports,
314 mg_types = final_type_env,
315 mg_insts = tcg_insts tcg_env,
316 mg_fam_insts = tcg_fam_insts tcg_env,
317 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
319 mg_binds = core_binds,
322 mg_rdr_env = emptyGlobalRdrEnv,
323 mg_fix_env = emptyFixityEnv,
324 mg_deprecs = NoDeprecs,
325 mg_foreign = NoStubs,
326 mg_hpc_info = noHpcInfo,
327 mg_modBreaks = emptyModBreaks,
328 mg_vect_info = noVectInfo
331 tcCoreDump mod_guts ;
336 mkFakeGroup decls -- Rather clumsy; lots of unused fields
337 = emptyRdrGroup { hs_tyclds = decls }
341 %************************************************************************
343 Type-checking the top level of a module
345 %************************************************************************
348 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
349 -- Returns the variables free in the decls
350 -- Reason: solely to report unused imports and bindings
351 tcRnSrcDecls boot_iface decls
352 = do { -- Do all the declarations
353 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
355 -- Finish simplifying class constraints
357 -- tcSimplifyTop deals with constant or ambiguous InstIds.
358 -- How could there be ambiguous ones? They can only arise if a
359 -- top-level decl falls under the monomorphism restriction
360 -- and no subsequent decl instantiates its type.
362 -- We do this after checkMain, so that we use the type info
363 -- thaat checkMain adds
365 -- We do it with both global and local env in scope:
366 -- * the global env exposes the instances to tcSimplifyTop
367 -- * the local env exposes the local Ids to tcSimplifyTop,
368 -- so that we get better error messages (monomorphism restriction)
369 traceTc (text "Tc8") ;
370 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
372 -- Backsubstitution. This must be done last.
373 -- Even tcSimplifyTop may do some unification.
374 traceTc (text "Tc9") ;
375 let { (tcg_env, _) = tc_envs
376 ; TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
377 tcg_rules = rules, tcg_fords = fords } = tcg_env
378 ; all_binds = binds `unionBags` inst_binds } ;
380 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
382 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
383 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
386 tcg_fords = fords' } } ;
388 return (tcg_env' { tcg_binds = tcg_binds tcg_env' })
391 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
392 -- Loops around dealing with each top level inter-splice group
393 -- in turn, until it's dealt with the entire module
394 tc_rn_src_decls boot_details ds
395 = do { let { (first_group, group_tail) = findSplice ds } ;
396 -- If ds is [] we get ([], Nothing)
398 -- Deal with decls up to, but not including, the first splice
399 (tcg_env, rn_decls) <- checkNoErrs $ rnTopSrcDecls first_group ;
400 -- checkNoErrs: stop if renaming fails
402 (tcg_env, tcl_env) <- setGblEnv tcg_env $
403 tcTopSrcDecls boot_details rn_decls ;
405 -- If there is no splice, we're nearly done
406 setEnvs (tcg_env, tcl_env) $
408 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
409 return (tcg_env, tcl_env)
412 -- If there's a splice, we must carry on
413 Just (SpliceDecl splice_expr, rest_ds) -> do {
415 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
418 -- Rename the splice expression, and get its supporting decls
419 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
420 -- checkNoErrs: don't typecheck if renaming failed
421 rnDump (ppr rn_splice_expr) ;
423 -- Execute the splice
424 spliced_decls <- tcSpliceDecls rn_splice_expr ;
426 -- Glue them on the front of the remaining decls and loop
427 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
428 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
433 %************************************************************************
435 Compiling hs-boot source files, and
436 comparing the hi-boot interface with the real thing
438 %************************************************************************
441 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
442 tcRnHsBootDecls decls
443 = do { let { (first_group, group_tail) = findSplice decls }
446 Just stuff -> spliceInHsBootErr stuff
449 -- Rename the declarations
450 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
451 ; setGblEnv tcg_env $ do {
453 -- Todo: check no foreign decls, no rules, no default decls
455 -- Typecheck type/class decls
456 ; traceTc (text "Tc2")
457 ; let tycl_decls = hs_tyclds rn_group
458 ; tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails tycl_decls)
459 ; setGblEnv tcg_env $ do {
461 -- Typecheck instance decls
462 ; traceTc (text "Tc3")
463 ; (tcg_env, inst_infos, _deriv_binds)
464 <- tcInstDecls1 tycl_decls (hs_instds rn_group) (hs_derivds rn_group)
465 ; setGblEnv tcg_env $ do {
467 -- Typecheck value declarations
468 ; traceTc (text "Tc5")
469 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
472 -- No simplification or zonking to do
473 ; traceTc (text "Tc7a")
474 ; gbl_env <- getGblEnv
476 -- Make the final type-env
477 -- Include the dfun_ids so that their type sigs
478 -- are written into the interface file
479 ; let { type_env0 = tcg_type_env gbl_env
480 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
481 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
482 ; dfun_ids = map iDFunId inst_infos }
483 ; return (gbl_env { tcg_type_env = type_env2 })
486 spliceInHsBootErr (SpliceDecl (L loc _), _)
487 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
490 Once we've typechecked the body of the module, we want to compare what
491 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
494 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
495 -- Compare the hi-boot file for this module (if there is one)
496 -- with the type environment we've just come up with
497 -- In the common case where there is no hi-boot file, the list
498 -- of boot_names is empty.
500 -- The bindings we return give bindings for the dfuns defined in the
501 -- hs-boot file, such as $fbEqT = $fEqT
504 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
505 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
506 tcg_type_env = local_type_env, tcg_exports = local_exports })
507 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
508 md_types = boot_type_env, md_exports = boot_exports })
509 | isHsBoot hs_src -- Current module is already a hs-boot file!
513 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
516 -- Check the exports of the boot module, one by one
517 ; mapM_ check_export boot_exports
519 -- Check instance declarations
520 ; mb_dfun_prs <- mapM check_inst boot_insts
521 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds,
522 tcg_type_env = extendTypeEnvWithIds local_type_env boot_dfuns }
523 dfun_prs = catMaybes mb_dfun_prs
524 boot_dfuns = map fst dfun_prs
525 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
526 | (boot_dfun, dfun) <- dfun_prs ]
528 -- Check for no family instances
529 ; unless (null boot_fam_insts) $
530 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
531 "instances in boot files yet...")
532 -- FIXME: Why? The actual comparison is not hard, but what would
533 -- be the equivalent to the dfun bindings returned for class
534 -- instances? We can't easily equate tycons...
538 check_export boot_avail -- boot_avail is exported by the boot iface
539 | name `elem` dfun_names = return ()
540 | isWiredInName name = return () -- No checking for wired-in names. In particular,
541 -- 'error' is handled by a rather gross hack
542 -- (see comments in GHC.Err.hs-boot)
544 -- Check that the actual module exports the same thing
545 | not (null missing_names)
546 = addErrTc (missingBootThing (head missing_names) "exported by")
548 -- If the boot module does not *define* the thing, we are done
549 -- (it simply re-exports it, and names match, so nothing further to do)
550 | isNothing mb_boot_thing = return ()
552 -- Check that the actual module also defines the thing, and
553 -- then compare the definitions
554 | Just real_thing <- lookupTypeEnv local_type_env name
555 = do { let boot_decl = tyThingToIfaceDecl (fromJust mb_boot_thing)
556 real_decl = tyThingToIfaceDecl real_thing
557 ; checkTc (checkBootDecl boot_decl real_decl)
558 (bootMisMatch real_thing boot_decl real_decl) }
559 -- The easiest way to check compatibility is to convert to
560 -- iface syntax, where we already have good comparison functions
563 = addErrTc (missingBootThing name "defined in")
565 name = availName boot_avail
566 mb_boot_thing = lookupTypeEnv boot_type_env name
567 missing_names = case lookupNameEnv local_export_env name of
569 Just avail -> availNames boot_avail `minusList` availNames avail
571 dfun_names = map getName boot_insts
573 local_export_env :: NameEnv AvailInfo
574 local_export_env = availsToNameEnv local_exports
576 check_inst :: Instance -> TcM (Maybe (Id, Id))
577 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
579 = case [dfun | inst <- local_insts,
580 let dfun = instanceDFunId inst,
581 idType dfun `tcEqType` boot_inst_ty ] of
582 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
583 (dfun:_) -> return (Just (local_boot_dfun, dfun))
585 boot_dfun = instanceDFunId boot_inst
586 boot_inst_ty = idType boot_dfun
587 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
591 missingBootThing thing what
592 = ppr thing <+> ptext SLIT("is exported by the hs-boot file, but not")
593 <+> text what <+> ptext SLIT("the module")
595 bootMisMatch thing boot_decl real_decl
596 = vcat [ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file"),
597 ptext SLIT("Main module:") <+> ppr real_decl,
598 ptext SLIT("Boot file: ") <+> ppr boot_decl]
602 2 (ptext SLIT("is defined in the hs-boot file, but not in the module itself"))
606 %************************************************************************
608 Type-checking the top level of a module
610 %************************************************************************
612 tcRnGroup takes a bunch of top-level source-code declarations, and
614 * gets supporting declarations from interface files
617 * and augments the TcGblEnv with the results
619 In Template Haskell it may be called repeatedly for each group of
620 declarations. It expects there to be an incoming TcGblEnv in the
621 monad; it augments it and returns the new TcGblEnv.
624 ------------------------------------------------
625 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
627 = do { -- Bring top level binders into scope
628 tcg_env <- importsFromLocalDecls group ;
629 setGblEnv tcg_env $ do {
631 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
633 -- Rename the source decls
634 (tcg_env, rn_decls) <- rnSrcDecls group ;
637 -- save the renamed syntax, if we want it
639 | Just grp <- tcg_rn_decls tcg_env
640 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
644 -- Dump trace of renaming part
645 rnDump (ppr rn_decls) ;
647 return (tcg_env', rn_decls)
650 ------------------------------------------------
651 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
652 tcTopSrcDecls boot_details
653 (HsGroup { hs_tyclds = tycl_decls,
654 hs_instds = inst_decls,
655 hs_derivds = deriv_decls,
656 hs_fords = foreign_decls,
657 hs_defds = default_decls,
658 hs_ruleds = rule_decls,
659 hs_valds = val_binds })
660 = do { -- Type-check the type and class decls, and all imported decls
661 -- The latter come in via tycl_decls
662 traceTc (text "Tc2") ;
664 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
665 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
666 -- an error we'd better stop now, to avoid a cascade
668 -- Make these type and class decls available to stuff slurped from interface files
669 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
672 setGblEnv tcg_env $ do {
673 -- Source-language instances, including derivings,
674 -- and import the supporting declarations
675 traceTc (text "Tc3") ;
676 (tcg_env, inst_infos, deriv_binds)
677 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
678 setGblEnv tcg_env $ do {
680 -- Foreign import declarations next. No zonking necessary
681 -- here; we can tuck them straight into the global environment.
682 traceTc (text "Tc4") ;
683 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
684 tcExtendGlobalValEnv fi_ids $ do {
686 -- Default declarations
687 traceTc (text "Tc4a") ;
688 default_tys <- tcDefaults default_decls ;
689 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
691 -- Value declarations next
692 -- We also typecheck any extra binds that came out
693 -- of the "deriving" process (deriv_binds)
694 traceTc (text "Tc5") ;
695 (tc_val_binds, tcl_env) <- tcTopBinds val_binds ;
696 setLclTypeEnv tcl_env $ do {
698 -- Now GHC-generated derived bindings and generics
699 -- Do not generate warnings from compiler-generated code
700 (tc_deriv_binds, tcl_env) <- discardWarnings $ setOptM Opt_GlasgowExts $
701 tcTopBinds deriv_binds ;
703 -- Second pass over class and instance declarations,
704 traceTc (text "Tc6") ;
705 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $ tcInstDecls2 tycl_decls inst_infos ;
706 showLIE (text "after instDecls2") ;
709 -- They need to be zonked, so we return them
710 traceTc (text "Tc7") ;
711 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
714 rules <- tcRules rule_decls ;
717 traceTc (text "Tc7a") ;
718 tcg_env <- getGblEnv ;
719 let { all_binds = tc_val_binds `unionBags`
720 tc_deriv_binds `unionBags`
721 inst_binds `unionBags`
724 -- Extend the GblEnv with the (as yet un-zonked)
725 -- bindings, rules, foreign decls
726 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
727 tcg_rules = tcg_rules tcg_env ++ rules,
728 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
729 return (tcg_env', tcl_env)
734 %************************************************************************
738 %************************************************************************
741 checkMain :: TcM TcGblEnv
742 -- If we are in module Main, check that 'main' is defined.
744 = do { tcg_env <- getGblEnv ;
746 check_main dflags tcg_env
749 check_main dflags tcg_env
751 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
755 = do { mb_main <- lookupSrcOcc_maybe main_fn
756 -- Check that 'main' is in scope
757 -- It might be imported from another module!
759 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
764 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
765 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
766 -- :Main.main :: IO () = runMainIO main
768 ; (main_expr, ty) <- addErrCtxt mainCtxt $
769 setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
772 -- See Note [Root-main Id]
773 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
774 (mkVarOccFS FSLIT("main"))
775 (getSrcSpan main_name)
776 ; root_main_id = Id.mkExportedLocalId root_main_name ty
777 ; main_bind = noLoc (VarBind root_main_id main_expr) }
779 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
781 tcg_dus = tcg_dus tcg_env
782 `plusDU` usesOnly (unitFV main_name)
783 -- Record the use of 'main', so that we don't
784 -- complain about it being defined but not used
788 mod = tcg_mod tcg_env
789 main_mod = mainModIs dflags
790 main_is_flag = mainFunIs dflags
792 main_fn = case main_is_flag of
793 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
794 Nothing -> main_RDR_Unqual
796 complain_no_main | ghcLink dflags == LinkInMemory = return ()
797 | otherwise = failWithTc noMainMsg
798 -- In interactive mode, don't worry about the absence of 'main'
799 -- In other modes, fail altogether, so that we don't go on
800 -- and complain a second time when processing the export list.
802 mainCtxt = ptext SLIT("When checking the type of the") <+> pp_main_fn
803 noMainMsg = ptext SLIT("The") <+> pp_main_fn
804 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
805 pp_main_fn | isJust main_is_flag = ptext SLIT("main function") <+> quotes (ppr main_fn)
806 | otherwise = ptext SLIT("function") <+> quotes (ppr main_fn)
811 The function that the RTS invokes is always :Main.main, which we call
812 root_main_id. (Because GHC allows the user to have a module not
813 called Main as the main module, we can't rely on the main function
814 being called "Main.main". That's why root_main_id has a fixed module
817 This is unusual: it's a LocalId whose Name has a Module from another
818 module. Tiresomely, we must filter it out again in MkIface, les we
819 get two defns for 'main' in the interface file!
822 %*********************************************************
826 %*********************************************************
830 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
831 setInteractiveContext hsc_env icxt thing_inside
833 -- Initialise the tcg_inst_env with instances
834 -- from all home modules. This mimics the more selective
835 -- call to hptInstances in tcRnModule
836 dfuns = fst (hptInstances hsc_env (\mod -> True))
838 updGblEnv (\env -> env {
839 tcg_rdr_env = ic_rn_gbl_env icxt,
840 tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
843 tcExtendGhciEnv (ic_tmp_ids icxt) $
844 -- tcExtendGhciEnv does lots:
845 -- - it extends the local type env (tcl_env) with the given Ids,
846 -- - it extends the local rdr env (tcl_rdr) with the Names from
848 -- - it adds the free tyvars of the Ids to the tcl_tyvars
851 -- later ids in ic_tmp_ids must shadow earlier ones with the same
852 -- OccName, and tcExtendIdEnv implements this behaviour.
854 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
861 -> InteractiveContext
863 -> IO (Maybe ([Id], LHsExpr Id))
864 -- The returned [Id] is the list of new Ids bound by
865 -- this statement. It can be used to extend the
866 -- InteractiveContext via extendInteractiveContext.
868 -- The returned TypecheckedHsExpr is of type IO [ () ],
869 -- a list of the bound values, coerced to ().
871 tcRnStmt hsc_env ictxt rdr_stmt
872 = initTcPrintErrors hsc_env iNTERACTIVE $
873 setInteractiveContext hsc_env ictxt $ do {
875 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
876 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
877 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
880 -- The real work is done here
881 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
882 zonked_expr <- zonkTopLExpr tc_expr ;
883 zonked_ids <- zonkTopBndrs bound_ids ;
885 -- None of the Ids should be of unboxed type, because we
886 -- cast them all to HValues in the end!
887 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
889 traceTc (text "tcs 1") ;
890 let { -- (a) Make all the bound ids "global" ids, now that
891 -- they're notionally top-level bindings. This is
892 -- important: otherwise when we come to compile an expression
893 -- using these ids later, the byte code generator will consider
894 -- the occurrences to be free rather than global.
896 -- (b) Tidy their types; this is important, because :info may
897 -- ask to look at them, and :info expects the things it looks
898 -- up to have tidy types
899 global_ids = map globaliseAndTidy zonked_ids ;
901 {- ---------------------------------------------
902 At one stage I removed any shadowed bindings from the type_env;
903 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
904 However, with Template Haskell they aren't necessarily inaccessible. Consider this
906 Prelude> let f n = n * 2 :: Int
907 Prelude> fName <- runQ [| f |]
908 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
910 Prelude> let f n = n * 3 :: Int
911 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
912 In the last line we use 'fName', which resolves to the *first* 'f'
913 in scope. If we delete it from the type env, GHCi crashes because
914 it doesn't expect that.
916 Hence this code is commented out
918 -------------------------------------------------- -}
921 dumpOptTcRn Opt_D_dump_tc
922 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
923 text "Typechecked expr" <+> ppr zonked_expr]) ;
925 returnM (global_ids, zonked_expr)
928 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
929 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
931 globaliseAndTidy :: Id -> Id
933 -- Give the Id a Global Name, and tidy its type
934 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
936 tidy_type = tidyTopType (idType id)
939 Here is the grand plan, implemented in tcUserStmt
941 What you type The IO [HValue] that hscStmt returns
942 ------------- ------------------------------------
943 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
946 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
949 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
950 [NB: result not printed] bindings: [it]
952 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
953 result showable) bindings: [it]
955 expr (of non-IO type,
956 result not showable) ==> error
960 ---------------------------
961 type PlanResult = ([Id], LHsExpr Id)
962 type Plan = TcM PlanResult
964 runPlans :: [Plan] -> TcM PlanResult
965 -- Try the plans in order. If one fails (by raising an exn), try the next.
966 -- If one succeeds, take it.
967 runPlans [] = panic "runPlans"
969 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
972 mkPlan :: LStmt Name -> TcM PlanResult
973 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
974 = do { uniq <- newUnique -- is treated very specially
975 ; let fresh_it = itName uniq
976 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
977 matches = [mkMatch [] expr emptyLocalBinds]
978 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
979 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
980 (HsVar bindIOName) noSyntaxExpr
981 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
982 (HsVar thenIOName) placeHolderType
985 -- [it <- e; print it] but not if it::()
987 -- [let it = e; print it]
988 ; runPlans [ -- Plan A
989 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
990 ; it_ty <- zonkTcType (idType it_id)
991 ; ifM (isUnitTy it_ty) failM
994 -- Plan B; a naked bind statment
995 tcGhciStmts [bind_stmt],
997 -- Plan C; check that the let-binding is typeable all by itself.
998 -- If not, fail; if so, try to print it.
999 -- The two-step process avoids getting two errors: one from
1000 -- the expression itself, and one from the 'print it' part
1001 -- This two-step story is very clunky, alas
1002 do { checkNoErrs (tcGhciStmts [let_stmt])
1003 --- checkNoErrs defeats the error recovery of let-bindings
1004 ; tcGhciStmts [let_stmt, print_it] }
1007 mkPlan stmt@(L loc (BindStmt {}))
1008 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1009 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1010 (HsVar thenIOName) placeHolderType
1012 ; print_bind_result <- doptM Opt_PrintBindResult
1013 ; let print_plan = do
1014 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1015 ; v_ty <- zonkTcType (idType v_id)
1016 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
1020 -- [stmt; print v] but not if v::()
1022 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1023 [tcGhciStmts [stmt]])
1027 = tcGhciStmts [stmt]
1029 ---------------------------
1030 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1032 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1033 ret_id <- tcLookupId returnIOName ; -- return @ IO
1035 io_ty = mkTyConApp ioTyCon [] ;
1036 ret_ty = mkListTy unitTy ;
1037 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1038 tc_io_stmts stmts = tcStmts DoExpr (tcDoStmt io_ty) stmts
1039 (emptyRefinement, io_ret_ty) ;
1041 names = map unLoc (collectLStmtsBinders stmts) ;
1043 -- mk_return builds the expression
1044 -- returnIO @ [()] [coerce () x, .., coerce () z]
1046 -- Despite the inconvenience of building the type applications etc,
1047 -- this *has* to be done in type-annotated post-typecheck form
1048 -- because we are going to return a list of *polymorphic* values
1049 -- coerced to type (). If we built a *source* stmt
1050 -- return [coerce x, ..., coerce z]
1051 -- then the type checker would instantiate x..z, and we wouldn't
1052 -- get their *polymorphic* values. (And we'd get ambiguity errs
1053 -- if they were overloaded, since they aren't applied to anything.)
1054 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1055 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1056 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1060 -- OK, we're ready to typecheck the stmts
1061 traceTc (text "tcs 2") ;
1062 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1063 mappM tcLookupId names ;
1064 -- Look up the names right in the middle,
1065 -- where they will all be in scope
1067 -- Simplify the context
1068 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1069 -- checkNoErrs ensures that the plan fails if context redn fails
1071 return (ids, mkHsDictLet const_binds $
1072 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1077 tcRnExpr just finds the type of an expression
1081 -> InteractiveContext
1084 tcRnExpr hsc_env ictxt rdr_expr
1085 = initTcPrintErrors hsc_env iNTERACTIVE $
1086 setInteractiveContext hsc_env ictxt $ do {
1088 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1091 -- Now typecheck the expression;
1092 -- it might have a rank-2 type (e.g. :t runST)
1093 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1094 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1095 tcSimplifyInteractive lie_top ;
1097 let { all_expr_ty = mkForAllTys qtvs $
1098 mkFunTys (map (idType . instToId) dict_insts) $
1100 zonkTcType all_expr_ty
1103 smpl_doc = ptext SLIT("main expression")
1106 tcRnType just finds the kind of a type
1110 -> InteractiveContext
1113 tcRnType hsc_env ictxt rdr_type
1114 = initTcPrintErrors hsc_env iNTERACTIVE $
1115 setInteractiveContext hsc_env ictxt $ do {
1117 rn_type <- rnLHsType doc rdr_type ;
1120 -- Now kind-check the type
1121 (ty', kind) <- kcHsType rn_type ;
1125 doc = ptext SLIT("In GHCi input")
1131 %************************************************************************
1133 More GHCi stuff, to do with browsing and getting info
1135 %************************************************************************
1139 -- ASSUMES that the module is either in the HomePackageTable or is
1140 -- a package module with an interface on disk. If neither of these is
1141 -- true, then the result will be an error indicating the interface
1142 -- could not be found.
1143 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1144 getModuleExports hsc_env mod
1147 checkMods = ic_toplev_scope ic ++ ic_exports ic
1149 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1151 -- Get the export avail info and also load all orphan and family-instance
1152 -- modules. Finally, check that the family instances of all modules in the
1153 -- interactive context are consistent (these modules are in the second
1155 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1156 tcGetModuleExports mod directlyImpMods
1157 = do { let doc = ptext SLIT("context for compiling statements")
1158 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1160 -- Load any orphan-module and family instance-module
1161 -- interfaces, so their instances are visible.
1162 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1163 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1165 -- Check that the family instances of all directly loaded
1166 -- modules are consistent.
1167 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1169 ; ifaceExportNames (mi_exports iface)
1172 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1173 tcRnLookupRdrName hsc_env rdr_name
1174 = initTcPrintErrors hsc_env iNTERACTIVE $
1175 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1176 lookup_rdr_name rdr_name
1178 lookup_rdr_name rdr_name = do {
1179 -- If the identifier is a constructor (begins with an
1180 -- upper-case letter), then we need to consider both
1181 -- constructor and type class identifiers.
1182 let { rdr_names = dataTcOccs rdr_name } ;
1184 -- results :: [Either Messages Name]
1185 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1187 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1188 -- The successful lookups will be (Just name)
1189 let { (warns_s, good_names) = unzip [ (msgs, name)
1190 | (msgs, Just name) <- results] ;
1191 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1193 -- Fail if nothing good happened, else add warnings
1194 if null good_names then
1195 -- No lookup succeeded, so
1196 -- pick the first error message and report it
1197 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1198 -- while the other is "X is not in scope",
1199 -- we definitely want the former; but we might pick the latter
1200 do { addMessages (head errs_s) ; failM }
1201 else -- Add deprecation warnings
1202 mapM_ addMessages warns_s ;
1207 tcRnRecoverDataCon :: HscEnv -> Ptr () -> IO (Maybe DataCon)
1208 tcRnRecoverDataCon hsc_env ptr
1209 = initTcPrintErrors hsc_env iNTERACTIVE $
1210 setInteractiveContext hsc_env (hsc_IC hsc_env) $ do
1211 name <- dataConInfoPtrToName ptr
1212 tcLookupDataCon name
1214 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1215 tcRnLookupName hsc_env name
1216 = initTcPrintErrors hsc_env iNTERACTIVE $
1217 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1218 tcRnLookupName' name
1220 -- To look up a name we have to look in the local environment (tcl_lcl)
1221 -- as well as the global environment, which is what tcLookup does.
1222 -- But we also want a TyThing, so we have to convert:
1224 tcRnLookupName' :: Name -> TcRn TyThing
1225 tcRnLookupName' name = do
1226 tcthing <- tcLookup name
1228 AGlobal thing -> return thing
1229 ATcId{tct_id=id} -> return (AnId id)
1230 _ -> panic "tcRnLookupName'"
1232 tcRnGetInfo :: HscEnv
1234 -> IO (Maybe (TyThing, Fixity, [Instance]))
1236 -- Used to implemnent :info in GHCi
1238 -- Look up a RdrName and return all the TyThings it might be
1239 -- A capitalised RdrName is given to us in the DataName namespace,
1240 -- but we want to treat it as *both* a data constructor
1241 -- *and* as a type or class constructor;
1242 -- hence the call to dataTcOccs, and we return up to two results
1243 tcRnGetInfo hsc_env name
1244 = initTcPrintErrors hsc_env iNTERACTIVE $
1245 let ictxt = hsc_IC hsc_env in
1246 setInteractiveContext hsc_env ictxt $ do
1248 -- Load the interface for all unqualified types and classes
1249 -- That way we will find all the instance declarations
1250 -- (Packages have not orphan modules, and we assume that
1251 -- in the home package all relevant modules are loaded.)
1252 loadUnqualIfaces ictxt
1254 thing <- tcRnLookupName' name
1255 fixity <- lookupFixityRn name
1256 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1257 return (thing, fixity, ispecs)
1259 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1260 -- Filter the instances by the ones whose tycons (or clases resp)
1261 -- are in scope unqualified. Otherwise we list a whole lot too many!
1262 lookupInsts print_unqual (AClass cls)
1263 = do { inst_envs <- tcGetInstEnvs
1265 | ispec <- classInstances inst_envs cls
1266 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1268 lookupInsts print_unqual (ATyCon tc)
1269 = do { eps <- getEps -- Load all instances for all classes that are
1270 -- in the type environment (which are all the ones
1271 -- we've seen in any interface file so far)
1272 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1274 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1275 , let dfun = instanceDFunId ispec
1277 , plausibleDFun print_unqual dfun ] }
1279 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1280 tc_name = tyConName tc
1282 lookupInsts print_unqual other = return []
1284 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1285 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1287 ok name | isBuiltInSyntax name = True
1288 | isExternalName name =
1289 isNothing $ fst print_unqual (nameModule name)
1293 loadUnqualIfaces :: InteractiveContext -> TcM ()
1294 -- Load the home module for everything that is in scope unqualified
1295 -- This is so that we can accurately report the instances for
1297 loadUnqualIfaces ictxt
1299 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1301 unqual_mods = [ nameModule name
1302 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1303 let name = gre_name gre,
1304 not (isInternalName name),
1305 isTcOcc (nameOccName name), -- Types and classes only
1306 unQualOK gre ] -- In scope unqualified
1307 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1311 %************************************************************************
1315 %************************************************************************
1318 rnDump :: SDoc -> TcRn ()
1319 -- Dump, with a banner, if -ddump-rn
1320 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1322 tcDump :: TcGblEnv -> TcRn ()
1324 = do { dflags <- getDOpts ;
1326 -- Dump short output if -ddump-types or -ddump-tc
1327 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1328 (dumpTcRn short_dump) ;
1330 -- Dump bindings if -ddump-tc
1331 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1334 short_dump = pprTcGblEnv env
1335 full_dump = pprLHsBinds (tcg_binds env)
1336 -- NB: foreign x-d's have undefined's in their types;
1337 -- hence can't show the tc_fords
1340 = do { dflags <- getDOpts ;
1341 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1342 (dumpTcRn (pprModGuts mod_guts)) ;
1344 -- Dump bindings if -ddump-tc
1345 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1347 full_dump = pprCoreBindings (mg_binds mod_guts)
1349 -- It's unpleasant having both pprModGuts and pprModDetails here
1350 pprTcGblEnv :: TcGblEnv -> SDoc
1351 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1353 tcg_fam_insts = fam_insts,
1355 tcg_imports = imports })
1356 = vcat [ ppr_types insts type_env
1357 , ppr_tycons fam_insts type_env
1359 , ppr_fam_insts fam_insts
1360 , vcat (map ppr rules)
1361 , ppr_gen_tycons (typeEnvTyCons type_env)
1362 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1363 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1365 pprModGuts :: ModGuts -> SDoc
1366 pprModGuts (ModGuts { mg_types = type_env,
1368 = vcat [ ppr_types [] type_env,
1371 ppr_types :: [Instance] -> TypeEnv -> SDoc
1372 ppr_types insts type_env
1373 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1375 dfun_ids = map instanceDFunId insts
1376 ids = [id | id <- typeEnvIds type_env, want_sig id]
1377 want_sig id | opt_PprStyle_Debug = True
1378 | otherwise = isLocalId id &&
1379 isExternalName (idName id) &&
1380 not (id `elem` dfun_ids)
1381 -- isLocalId ignores data constructors, records selectors etc.
1382 -- The isExternalName ignores local dictionary and method bindings
1383 -- that the type checker has invented. Top-level user-defined things
1384 -- have External names.
1386 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1387 ppr_tycons fam_insts type_env
1388 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1390 fi_tycons = map famInstTyCon fam_insts
1391 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1392 want_tycon tycon | opt_PprStyle_Debug = True
1393 | otherwise = not (isImplicitTyCon tycon) &&
1394 isExternalName (tyConName tycon) &&
1395 not (tycon `elem` fi_tycons)
1397 ppr_insts :: [Instance] -> SDoc
1398 ppr_insts [] = empty
1399 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1401 ppr_fam_insts :: [FamInst] -> SDoc
1402 ppr_fam_insts [] = empty
1403 ppr_fam_insts fam_insts =
1404 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1406 ppr_sigs :: [Var] -> SDoc
1408 -- Print type signatures; sort by OccName
1409 = vcat (map ppr_sig (sortLe le_sig ids))
1411 le_sig id1 id2 = getOccName id1 <= getOccName id2
1412 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1414 ppr_tydecls :: [TyCon] -> SDoc
1416 -- Print type constructor info; sort by OccName
1417 = vcat (map ppr_tycon (sortLe le_sig tycons))
1419 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1421 | isCoercionTyCon tycon = ptext SLIT("coercion") <+> ppr tycon
1422 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1424 ppr_rules :: [CoreRule] -> SDoc
1425 ppr_rules [] = empty
1426 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1427 nest 4 (pprRules rs),
1430 ppr_gen_tycons [] = empty
1431 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1432 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]