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,
28 #include "HsVersions.h"
32 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
94 import {- Kind parts of -} Type
96 import Foreign.Ptr( Ptr )
105 import Data.Maybe ( isJust )
111 %************************************************************************
113 Typecheck and rename a module
115 %************************************************************************
121 -> Bool -- True <=> save renamed syntax
122 -> Located (HsModule RdrName)
123 -> IO (Messages, Maybe TcGblEnv)
125 tcRnModule hsc_env hsc_src save_rn_syntax
126 (L loc (HsModule maybe_mod export_ies
127 import_decls local_decls mod_deprec
128 module_info maybe_doc))
129 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
131 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
132 this_mod = case maybe_mod of
133 Nothing -> mAIN -- 'module M where' is omitted
134 Just (L _ mod) -> mkModule this_pkg mod } ;
137 initTc hsc_env hsc_src save_rn_syntax this_mod $
139 do { -- Deal with imports;
140 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
141 setGblEnv tcg_env $ do {
143 -- Load the hi-boot interface for this module, if any
144 -- We do this now so that the boot_names can be passed
145 -- to tcTyAndClassDecls, because the boot_names are
146 -- automatically considered to be loop breakers
148 -- Do this *after* tcRnImports, so that we know whether
149 -- a module that we import imports us; and hence whether to
150 -- look for a hi-boot file
151 boot_iface <- tcHiBootIface hsc_src this_mod ;
153 -- Rename and type check the declarations
154 traceRn (text "rn1a") ;
155 tcg_env <- if isHsBoot hsc_src then
156 tcRnHsBootDecls local_decls
158 tcRnSrcDecls boot_iface local_decls ;
159 setGblEnv tcg_env $ do {
161 -- Report the use of any deprecated things
162 -- We do this *before* processsing the export list so
163 -- that we don't bleat about re-exporting a deprecated
164 -- thing (especially via 'module Foo' export item)
165 -- That is, only uses in the *body* of the module are complained about
166 traceRn (text "rn3") ;
167 failIfErrsM ; -- finishDeprecations crashes sometimes
168 -- as a result of typechecker repairs (e.g. unboundNames)
169 tcg_env <- finishDeprecations (hsc_dflags hsc_env) mod_deprec tcg_env ;
171 -- Process the export list
172 traceRn (text "rn4a: before exports");
173 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
174 traceRn (text "rn4b: after exportss") ;
176 -- Compare the hi-boot iface (if any) with the real thing
177 -- Must be done after processing the exports
178 tcg_env <- checkHiBootIface tcg_env boot_iface ;
180 -- Make the new type env available to stuff slurped from interface files
181 -- Must do this after checkHiBootIface, because the latter might add new
182 -- bindings for boot_dfuns, which may be mentioned in imported unfoldings
183 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
185 -- Rename the Haddock documentation
186 tcg_env <- rnHaddock module_info maybe_doc tcg_env ;
188 -- Report unused names
189 reportUnusedNames export_ies tcg_env ;
191 -- Dump output and return
198 %************************************************************************
202 %************************************************************************
205 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
206 tcRnImports hsc_env this_mod import_decls
207 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
209 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
210 ; dep_mods = imp_dep_mods imports
212 -- We want instance declarations from all home-package
213 -- modules below this one, including boot modules, except
214 -- ourselves. The 'except ourselves' is so that we don't
215 -- get the instances from this module's hs-boot file
216 ; want_instances :: ModuleName -> Bool
217 ; want_instances mod = mod `elemUFM` dep_mods
218 && mod /= moduleName this_mod
219 ; (home_insts, home_fam_insts) = hptInstances hsc_env
223 -- Record boot-file info in the EPS, so that it's
224 -- visible to loadHiBootInterface in tcRnSrcDecls,
225 -- and any other incrementally-performed imports
226 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
228 -- Update the gbl env
229 ; updGblEnv ( \ gbl ->
231 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
232 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
233 tcg_rn_imports = fmap (const rn_imports) (tcg_rn_imports gbl),
234 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
235 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
240 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
241 -- Fail if there are any errors so far
242 -- The error printing (if needed) takes advantage
243 -- of the tcg_env we have now set
244 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
247 -- Load any orphan-module and family instance-module
248 -- interfaces, so that their rules and instance decls will be
250 ; loadOrphanModules (imp_orphs imports) False
251 ; loadOrphanModules (imp_finsts imports) True
253 -- Check type-familily consistency
254 ; traceRn (text "rn1: checking family instance consistency")
255 ; let { dir_imp_mods = map (\ (mod, _) -> mod)
259 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
265 %************************************************************************
267 Type-checking external-core modules
269 %************************************************************************
272 tcRnExtCore :: HscEnv
274 -> IO (Messages, Maybe ModGuts)
275 -- Nothing => some error occurred
277 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
278 -- The decls are IfaceDecls; all names are original names
279 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
281 initTc hsc_env ExtCoreFile False this_mod $ do {
283 let { ldecls = map noLoc decls } ;
285 -- bring the type and class decls into scope
286 -- ToDo: check that this doesn't need to extract the val binds.
287 -- It seems that only the type and class decls need to be in scope below because
288 -- (a) tcTyAndClassDecls doesn't need the val binds, and
289 -- (b) tcExtCoreBindings doesn't need anything
290 -- (in fact, it might not even need to be in the scope of
291 -- this tcg_env at all)
292 tcg_env <- importsFromLocalDecls False (mkFakeGroup ldecls)
293 emptyUFM {- no fixity decls -} ;
295 setGblEnv tcg_env $ 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 { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
776 -- :Main.main :: IO () = runMainIO main
778 ; (main_expr, ty) <- addErrCtxt mainCtxt $
779 setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
782 -- See Note [Root-main Id]
783 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
784 (mkVarOccFS FSLIT("main"))
785 (getSrcSpan main_name)
786 ; root_main_id = Id.mkExportedLocalId root_main_name ty
787 ; main_bind = noLoc (VarBind root_main_id main_expr) }
789 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
791 tcg_dus = tcg_dus tcg_env
792 `plusDU` usesOnly (unitFV main_name)
793 -- Record the use of 'main', so that we don't
794 -- complain about it being defined but not used
798 mod = tcg_mod tcg_env
799 main_mod = mainModIs dflags
800 main_is_flag = mainFunIs dflags
802 main_fn = case main_is_flag of
803 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
804 Nothing -> main_RDR_Unqual
806 complain_no_main | ghcLink dflags == LinkInMemory = return ()
807 | otherwise = failWithTc noMainMsg
808 -- In interactive mode, don't worry about the absence of 'main'
809 -- In other modes, fail altogether, so that we don't go on
810 -- and complain a second time when processing the export list.
812 mainCtxt = ptext SLIT("When checking the type of the") <+> pp_main_fn
813 noMainMsg = ptext SLIT("The") <+> pp_main_fn
814 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
815 pp_main_fn | isJust main_is_flag = ptext SLIT("main function") <+> quotes (ppr main_fn)
816 | otherwise = ptext SLIT("function") <+> quotes (ppr main_fn)
821 The function that the RTS invokes is always :Main.main, which we call
822 root_main_id. (Because GHC allows the user to have a module not
823 called Main as the main module, we can't rely on the main function
824 being called "Main.main". That's why root_main_id has a fixed module
827 This is unusual: it's a LocalId whose Name has a Module from another
828 module. Tiresomely, we must filter it out again in MkIface, les we
829 get two defns for 'main' in the interface file!
832 %*********************************************************
836 %*********************************************************
840 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
841 setInteractiveContext hsc_env icxt thing_inside
842 = let -- Initialise the tcg_inst_env with instances from all home modules.
843 -- This mimics the more selective call to hptInstances in tcRnModule.
844 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
846 updGblEnv (\env -> env {
847 tcg_rdr_env = ic_rn_gbl_env icxt,
848 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
849 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
853 tcExtendGhciEnv (ic_tmp_ids icxt) $
854 -- tcExtendGhciEnv does lots:
855 -- - it extends the local type env (tcl_env) with the given Ids,
856 -- - it extends the local rdr env (tcl_rdr) with the Names from
858 -- - it adds the free tyvars of the Ids to the tcl_tyvars
861 -- later ids in ic_tmp_ids must shadow earlier ones with the same
862 -- OccName, and tcExtendIdEnv implements this behaviour.
864 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
871 -> InteractiveContext
873 -> IO (Maybe ([Id], LHsExpr Id))
874 -- The returned [Id] is the list of new Ids bound by
875 -- this statement. It can be used to extend the
876 -- InteractiveContext via extendInteractiveContext.
878 -- The returned TypecheckedHsExpr is of type IO [ () ],
879 -- a list of the bound values, coerced to ().
881 tcRnStmt hsc_env ictxt rdr_stmt
882 = initTcPrintErrors hsc_env iNTERACTIVE $
883 setInteractiveContext hsc_env ictxt $ do {
885 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
886 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
887 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
889 rnDump (ppr rn_stmt) ;
891 -- The real work is done here
892 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
893 zonked_expr <- zonkTopLExpr tc_expr ;
894 zonked_ids <- zonkTopBndrs bound_ids ;
896 -- None of the Ids should be of unboxed type, because we
897 -- cast them all to HValues in the end!
898 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
900 traceTc (text "tcs 1") ;
901 let { global_ids = map globaliseAndTidy zonked_ids } ;
903 {- ---------------------------------------------
904 At one stage I removed any shadowed bindings from the type_env;
905 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
906 However, with Template Haskell they aren't necessarily inaccessible. Consider this
908 Prelude> let f n = n * 2 :: Int
909 Prelude> fName <- runQ [| f |]
910 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
912 Prelude> let f n = n * 3 :: Int
913 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
914 In the last line we use 'fName', which resolves to the *first* 'f'
915 in scope. If we delete it from the type env, GHCi crashes because
916 it doesn't expect that.
918 Hence this code is commented out
920 -------------------------------------------------- -}
922 dumpOptTcRn Opt_D_dump_tc
923 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
924 text "Typechecked expr" <+> ppr zonked_expr]) ;
926 return (global_ids, zonked_expr)
929 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
930 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
932 globaliseAndTidy :: Id -> Id
933 globaliseAndTidy id -- Note [Interactively-bound Ids in GHCi]
934 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
936 tidy_type = tidyTopType (idType id)
939 Note [Interactively-bound Ids in GHCi]
940 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
941 The Ids bound by previous Stmts in Template Haskell are currently
943 b) with an Internal Name (not External)
946 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
947 compile an expression using these ids later, the byte code
948 generator will consider the occurrences to be free rather than
951 (b) They retain their Internal names becuase we don't have a suitable
952 Module to name them with. We could revisit this choice.
954 (c) Their types are tidied. This is important, because :info may ask
955 to look at them, and :info expects the things it looks up to have
959 --------------------------------------------------------------------------
960 Typechecking Stmts in GHCi
962 Here is the grand plan, implemented in tcUserStmt
964 What you type The IO [HValue] that hscStmt returns
965 ------------- ------------------------------------
966 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
969 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
972 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
973 [NB: result not printed] bindings: [it]
975 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
976 result showable) bindings: [it]
978 expr (of non-IO type,
979 result not showable) ==> error
983 ---------------------------
984 type PlanResult = ([Id], LHsExpr Id)
985 type Plan = TcM PlanResult
987 runPlans :: [Plan] -> TcM PlanResult
988 -- Try the plans in order. If one fails (by raising an exn), try the next.
989 -- If one succeeds, take it.
990 runPlans [] = panic "runPlans"
992 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
995 mkPlan :: LStmt Name -> TcM PlanResult
996 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
997 = do { uniq <- newUnique -- is treated very specially
998 ; let fresh_it = itName uniq
999 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1000 matches = [mkMatch [] expr emptyLocalBinds]
1001 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1002 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1003 (HsVar bindIOName) noSyntaxExpr
1004 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1005 (HsVar thenIOName) placeHolderType
1008 -- [it <- e; print it] but not if it::()
1010 -- [let it = e; print it]
1011 ; runPlans [ -- Plan A
1012 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1013 ; it_ty <- zonkTcType (idType it_id)
1014 ; when (isUnitTy it_ty) failM
1017 -- Plan B; a naked bind statment
1018 tcGhciStmts [bind_stmt],
1020 -- Plan C; check that the let-binding is typeable all by itself.
1021 -- If not, fail; if so, try to print it.
1022 -- The two-step process avoids getting two errors: one from
1023 -- the expression itself, and one from the 'print it' part
1024 -- This two-step story is very clunky, alas
1025 do { checkNoErrs (tcGhciStmts [let_stmt])
1026 --- checkNoErrs defeats the error recovery of let-bindings
1027 ; tcGhciStmts [let_stmt, print_it] }
1030 mkPlan stmt@(L loc (BindStmt {}))
1031 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1032 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1033 (HsVar thenIOName) placeHolderType
1035 ; print_bind_result <- doptM Opt_PrintBindResult
1036 ; let print_plan = do
1037 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1038 ; v_ty <- zonkTcType (idType v_id)
1039 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1043 -- [stmt; print v] but not if v::()
1045 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1046 [tcGhciStmts [stmt]])
1050 = tcGhciStmts [stmt]
1052 ---------------------------
1053 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1055 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1056 ret_id <- tcLookupId returnIOName ; -- return @ IO
1058 ret_ty = mkListTy unitTy ;
1059 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1060 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1062 names = map unLoc (collectLStmtsBinders stmts) ;
1064 -- mk_return builds the expression
1065 -- returnIO @ [()] [coerce () x, .., coerce () z]
1067 -- Despite the inconvenience of building the type applications etc,
1068 -- this *has* to be done in type-annotated post-typecheck form
1069 -- because we are going to return a list of *polymorphic* values
1070 -- coerced to type (). If we built a *source* stmt
1071 -- return [coerce x, ..., coerce z]
1072 -- then the type checker would instantiate x..z, and we wouldn't
1073 -- get their *polymorphic* values. (And we'd get ambiguity errs
1074 -- if they were overloaded, since they aren't applied to anything.)
1075 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1076 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1077 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1081 -- OK, we're ready to typecheck the stmts
1082 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1083 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1084 mapM tcLookupId names ;
1085 -- Look up the names right in the middle,
1086 -- where they will all be in scope
1088 -- Simplify the context
1089 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1090 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1091 -- checkNoErrs ensures that the plan fails if context redn fails
1093 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1094 return (ids, mkHsDictLet const_binds $
1095 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1100 tcRnExpr just finds the type of an expression
1104 -> InteractiveContext
1107 tcRnExpr hsc_env ictxt rdr_expr
1108 = initTcPrintErrors hsc_env iNTERACTIVE $
1109 setInteractiveContext hsc_env ictxt $ do {
1111 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1114 -- Now typecheck the expression;
1115 -- it might have a rank-2 type (e.g. :t runST)
1116 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1117 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1118 tcSimplifyInteractive lie_top ;
1120 let { all_expr_ty = mkForAllTys qtvs $
1121 mkFunTys (map (idType . instToId) dict_insts) $
1123 zonkTcType all_expr_ty
1126 smpl_doc = ptext SLIT("main expression")
1129 tcRnType just finds the kind of a type
1133 -> InteractiveContext
1136 tcRnType hsc_env ictxt rdr_type
1137 = initTcPrintErrors hsc_env iNTERACTIVE $
1138 setInteractiveContext hsc_env ictxt $ do {
1140 rn_type <- rnLHsType doc rdr_type ;
1143 -- Now kind-check the type
1144 (ty', kind) <- kcHsType rn_type ;
1148 doc = ptext SLIT("In GHCi input")
1154 %************************************************************************
1156 More GHCi stuff, to do with browsing and getting info
1158 %************************************************************************
1162 -- ASSUMES that the module is either in the HomePackageTable or is
1163 -- a package module with an interface on disk. If neither of these is
1164 -- true, then the result will be an error indicating the interface
1165 -- could not be found.
1166 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1167 getModuleExports hsc_env mod
1170 checkMods = ic_toplev_scope ic ++ ic_exports ic
1172 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1174 -- Get the export avail info and also load all orphan and family-instance
1175 -- modules. Finally, check that the family instances of all modules in the
1176 -- interactive context are consistent (these modules are in the second
1178 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1179 tcGetModuleExports mod directlyImpMods
1180 = do { let doc = ptext SLIT("context for compiling statements")
1181 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1183 -- Load any orphan-module and family instance-module
1184 -- interfaces, so their instances are visible.
1185 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1186 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1188 -- Check that the family instances of all directly loaded
1189 -- modules are consistent.
1190 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1192 ; ifaceExportNames (mi_exports iface)
1195 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1196 tcRnLookupRdrName hsc_env rdr_name
1197 = initTcPrintErrors hsc_env iNTERACTIVE $
1198 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1199 lookup_rdr_name rdr_name
1201 lookup_rdr_name rdr_name = do {
1202 -- If the identifier is a constructor (begins with an
1203 -- upper-case letter), then we need to consider both
1204 -- constructor and type class identifiers.
1205 let { rdr_names = dataTcOccs rdr_name } ;
1207 -- results :: [Either Messages Name]
1208 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1210 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1211 -- The successful lookups will be (Just name)
1212 let { (warns_s, good_names) = unzip [ (msgs, name)
1213 | (msgs, Just name) <- results] ;
1214 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1216 -- Fail if nothing good happened, else add warnings
1217 if null good_names then
1218 -- No lookup succeeded, so
1219 -- pick the first error message and report it
1220 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1221 -- while the other is "X is not in scope",
1222 -- we definitely want the former; but we might pick the latter
1223 do { addMessages (head errs_s) ; failM }
1224 else -- Add deprecation warnings
1225 mapM_ addMessages warns_s ;
1230 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1231 tcRnLookupName hsc_env name
1232 = initTcPrintErrors hsc_env iNTERACTIVE $
1233 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1234 tcRnLookupName' name
1236 -- To look up a name we have to look in the local environment (tcl_lcl)
1237 -- as well as the global environment, which is what tcLookup does.
1238 -- But we also want a TyThing, so we have to convert:
1240 tcRnLookupName' :: Name -> TcRn TyThing
1241 tcRnLookupName' name = do
1242 tcthing <- tcLookup name
1244 AGlobal thing -> return thing
1245 ATcId{tct_id=id} -> return (AnId id)
1246 _ -> panic "tcRnLookupName'"
1248 tcRnGetInfo :: HscEnv
1250 -> IO (Maybe (TyThing, Fixity, [Instance]))
1252 -- Used to implemnent :info in GHCi
1254 -- Look up a RdrName and return all the TyThings it might be
1255 -- A capitalised RdrName is given to us in the DataName namespace,
1256 -- but we want to treat it as *both* a data constructor
1257 -- *and* as a type or class constructor;
1258 -- hence the call to dataTcOccs, and we return up to two results
1259 tcRnGetInfo hsc_env name
1260 = initTcPrintErrors hsc_env iNTERACTIVE $
1261 let ictxt = hsc_IC hsc_env in
1262 setInteractiveContext hsc_env ictxt $ do
1264 -- Load the interface for all unqualified types and classes
1265 -- That way we will find all the instance declarations
1266 -- (Packages have not orphan modules, and we assume that
1267 -- in the home package all relevant modules are loaded.)
1268 loadUnqualIfaces ictxt
1270 thing <- tcRnLookupName' name
1271 fixity <- lookupFixityRn name
1272 ispecs <- lookupInsts thing
1273 return (thing, fixity, ispecs)
1275 lookupInsts :: TyThing -> TcM [Instance]
1276 lookupInsts (AClass cls)
1277 = do { inst_envs <- tcGetInstEnvs
1278 ; return (classInstances inst_envs cls) }
1280 lookupInsts (ATyCon tc)
1281 = do { eps <- getEps -- Load all instances for all classes that are
1282 -- in the type environment (which are all the ones
1283 -- we've seen in any interface file so far)
1284 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1286 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1287 , let dfun = instanceDFunId ispec
1290 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1291 tc_name = tyConName tc
1293 lookupInsts other = return []
1295 loadUnqualIfaces :: InteractiveContext -> TcM ()
1296 -- Load the home module for everything that is in scope unqualified
1297 -- This is so that we can accurately report the instances for
1299 loadUnqualIfaces ictxt
1301 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1303 unqual_mods = [ nameModule name
1304 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1305 let name = gre_name gre,
1306 not (isInternalName name),
1307 isTcOcc (nameOccName name), -- Types and classes only
1308 unQualOK gre ] -- In scope unqualified
1309 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1313 %************************************************************************
1317 %************************************************************************
1320 rnDump :: SDoc -> TcRn ()
1321 -- Dump, with a banner, if -ddump-rn
1322 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1324 tcDump :: TcGblEnv -> TcRn ()
1326 = do { dflags <- getDOpts ;
1328 -- Dump short output if -ddump-types or -ddump-tc
1329 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1330 (dumpTcRn short_dump) ;
1332 -- Dump bindings if -ddump-tc
1333 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1336 short_dump = pprTcGblEnv env
1337 full_dump = pprLHsBinds (tcg_binds env)
1338 -- NB: foreign x-d's have undefined's in their types;
1339 -- hence can't show the tc_fords
1342 = do { dflags <- getDOpts ;
1343 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1344 (dumpTcRn (pprModGuts mod_guts)) ;
1346 -- Dump bindings if -ddump-tc
1347 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1349 full_dump = pprCoreBindings (mg_binds mod_guts)
1351 -- It's unpleasant having both pprModGuts and pprModDetails here
1352 pprTcGblEnv :: TcGblEnv -> SDoc
1353 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1355 tcg_fam_insts = fam_insts,
1357 tcg_imports = imports })
1358 = vcat [ ppr_types insts type_env
1359 , ppr_tycons fam_insts type_env
1361 , ppr_fam_insts fam_insts
1362 , vcat (map ppr rules)
1363 , ppr_gen_tycons (typeEnvTyCons type_env)
1364 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1365 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1367 pprModGuts :: ModGuts -> SDoc
1368 pprModGuts (ModGuts { mg_types = type_env,
1370 = vcat [ ppr_types [] type_env,
1373 ppr_types :: [Instance] -> TypeEnv -> SDoc
1374 ppr_types insts type_env
1375 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1377 dfun_ids = map instanceDFunId insts
1378 ids = [id | id <- typeEnvIds type_env, want_sig id]
1379 want_sig id | opt_PprStyle_Debug = True
1380 | otherwise = isLocalId id &&
1381 isExternalName (idName id) &&
1382 not (id `elem` dfun_ids)
1383 -- isLocalId ignores data constructors, records selectors etc.
1384 -- The isExternalName ignores local dictionary and method bindings
1385 -- that the type checker has invented. Top-level user-defined things
1386 -- have External names.
1388 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1389 ppr_tycons fam_insts type_env
1390 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1392 fi_tycons = map famInstTyCon fam_insts
1393 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1394 want_tycon tycon | opt_PprStyle_Debug = True
1395 | otherwise = not (isImplicitTyCon tycon) &&
1396 isExternalName (tyConName tycon) &&
1397 not (tycon `elem` fi_tycons)
1399 ppr_insts :: [Instance] -> SDoc
1400 ppr_insts [] = empty
1401 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1403 ppr_fam_insts :: [FamInst] -> SDoc
1404 ppr_fam_insts [] = empty
1405 ppr_fam_insts fam_insts =
1406 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1408 ppr_sigs :: [Var] -> SDoc
1410 -- Print type signatures; sort by OccName
1411 = vcat (map ppr_sig (sortLe le_sig ids))
1413 le_sig id1 id2 = getOccName id1 <= getOccName id2
1414 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1416 ppr_tydecls :: [TyCon] -> SDoc
1418 -- Print type constructor info; sort by OccName
1419 = vcat (map ppr_tycon (sortLe le_sig tycons))
1421 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1423 | isCoercionTyCon tycon = ptext SLIT("coercion") <+> ppr tycon
1424 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1426 ppr_rules :: [CoreRule] -> SDoc
1427 ppr_rules [] = empty
1428 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1429 nest 4 (pprRules rs),
1432 ppr_gen_tycons [] = empty
1433 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1434 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]