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 )
95 import {- Kind parts of -} Type
97 import Foreign.Ptr( Ptr )
105 import Control.Monad ( unless )
106 import Data.Maybe ( isJust )
112 %************************************************************************
114 Typecheck and rename a module
116 %************************************************************************
122 -> Bool -- True <=> save renamed syntax
123 -> Located (HsModule RdrName)
124 -> IO (Messages, Maybe TcGblEnv)
126 tcRnModule hsc_env hsc_src save_rn_syntax
127 (L loc (HsModule maybe_mod export_ies
128 import_decls local_decls mod_deprec
129 module_info maybe_doc))
130 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
132 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
133 this_mod = case maybe_mod of
134 Nothing -> mAIN -- 'module M where' is omitted
135 Just (L _ mod) -> mkModule this_pkg mod } ;
138 initTc hsc_env hsc_src save_rn_syntax this_mod $
140 do { -- Deal with imports;
141 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
142 setGblEnv tcg_env $ do {
144 -- Load the hi-boot interface for this module, if any
145 -- We do this now so that the boot_names can be passed
146 -- to tcTyAndClassDecls, because the boot_names are
147 -- automatically considered to be loop breakers
149 -- Do this *after* tcRnImports, so that we know whether
150 -- a module that we import imports us; and hence whether to
151 -- look for a hi-boot file
152 boot_iface <- tcHiBootIface hsc_src this_mod ;
154 -- Rename and type check the declarations
155 traceRn (text "rn1a") ;
156 tcg_env <- if isHsBoot hsc_src then
157 tcRnHsBootDecls local_decls
159 tcRnSrcDecls boot_iface local_decls ;
160 setGblEnv tcg_env $ do {
162 -- Report the use of any deprecated things
163 -- We do this *before* processsing the export list so
164 -- that we don't bleat about re-exporting a deprecated
165 -- thing (especially via 'module Foo' export item)
166 -- That is, only uses in the *body* of the module are complained about
167 traceRn (text "rn3") ;
168 failIfErrsM ; -- finishDeprecations crashes sometimes
169 -- as a result of typechecker repairs (e.g. unboundNames)
170 tcg_env <- finishDeprecations (hsc_dflags hsc_env) mod_deprec tcg_env ;
172 -- Process the export list
173 traceRn (text "rn4a: before exports");
174 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
175 traceRn (text "rn4b: after exportss") ;
177 -- Compare the hi-boot iface (if any) with the real thing
178 -- Must be done after processing the exports
179 tcg_env <- checkHiBootIface tcg_env boot_iface ;
181 -- Make the new type env available to stuff slurped from interface files
182 -- Must do this after checkHiBootIface, because the latter might add new
183 -- bindings for boot_dfuns, which may be mentioned in imported unfoldings
184 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
186 -- Rename the Haddock documentation
187 tcg_env <- rnHaddock module_info maybe_doc tcg_env ;
189 -- Report unused names
190 reportUnusedNames export_ies tcg_env ;
192 -- Dump output and return
199 %************************************************************************
203 %************************************************************************
206 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
207 tcRnImports hsc_env this_mod import_decls
208 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
210 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
211 ; dep_mods = imp_dep_mods imports
213 -- We want instance declarations from all home-package
214 -- modules below this one, including boot modules, except
215 -- ourselves. The 'except ourselves' is so that we don't
216 -- get the instances from this module's hs-boot file
217 ; want_instances :: ModuleName -> Bool
218 ; want_instances mod = mod `elemUFM` dep_mods
219 && mod /= moduleName this_mod
220 ; (home_insts, home_fam_insts) = hptInstances hsc_env
224 -- Record boot-file info in the EPS, so that it's
225 -- visible to loadHiBootInterface in tcRnSrcDecls,
226 -- and any other incrementally-performed imports
227 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
229 -- Update the gbl env
230 ; updGblEnv ( \ gbl ->
232 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
233 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
234 tcg_rn_imports = fmap (const rn_imports) (tcg_rn_imports gbl),
235 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
236 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
241 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
242 -- Fail if there are any errors so far
243 -- The error printing (if needed) takes advantage
244 -- of the tcg_env we have now set
245 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
248 -- Load any orphan-module and family instance-module
249 -- interfaces, so that their rules and instance decls will be
251 ; loadOrphanModules (imp_orphs imports) False
252 ; loadOrphanModules (imp_finsts imports) True
254 -- Check type-familily consistency
255 ; traceRn (text "rn1: checking family instance consistency")
256 ; let { dir_imp_mods = map (\ (mod, _) -> mod)
260 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
266 %************************************************************************
268 Type-checking external-core modules
270 %************************************************************************
273 tcRnExtCore :: HscEnv
275 -> IO (Messages, Maybe ModGuts)
276 -- Nothing => some error occurred
278 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
279 -- The decls are IfaceDecls; all names are original names
280 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
282 initTc hsc_env ExtCoreFile False this_mod $ do {
284 let { ldecls = map noLoc decls } ;
286 -- bring the type and class decls into scope
287 -- ToDo: check that this doesn't need to extract the val binds.
288 -- It seems that only the type and class decls need to be in scope below because
289 -- (a) tcTyAndClassDecls doesn't need the val binds, and
290 -- (b) tcExtCoreBindings doesn't need anything
291 -- (in fact, it might not even need to be in the scope of
292 -- this tcg_env at all)
293 tcg_env <- importsFromLocalDecls False (mkFakeGroup ldecls)
294 emptyUFM {- no fixity decls -} ;
296 setGblEnv tcg_env $ do {
298 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
300 -- Dump trace of renaming part
301 rnDump (ppr rn_decls) ;
303 -- Typecheck them all together so that
304 -- any mutually recursive types are done right
305 tcg_env <- tcTyAndClassDecls emptyModDetails rn_decls ;
306 -- Make the new type env available to stuff slurped from interface files
308 setGblEnv tcg_env $ do {
310 -- Now the core bindings
311 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
315 bndrs = bindersOfBinds core_binds ;
316 my_exports = map (Avail . idName) bndrs ;
317 -- ToDo: export the data types also?
319 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
321 mod_guts = ModGuts { mg_module = this_mod,
323 mg_usages = [], -- ToDo: compute usage
324 mg_dir_imps = [], -- ??
325 mg_deps = noDependencies, -- ??
326 mg_exports = my_exports,
327 mg_types = final_type_env,
328 mg_insts = tcg_insts tcg_env,
329 mg_fam_insts = tcg_fam_insts tcg_env,
330 mg_inst_env = tcg_inst_env tcg_env,
331 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
333 mg_binds = core_binds,
336 mg_rdr_env = emptyGlobalRdrEnv,
337 mg_fix_env = emptyFixityEnv,
338 mg_deprecs = NoDeprecs,
339 mg_foreign = NoStubs,
340 mg_hpc_info = emptyHpcInfo False,
341 mg_modBreaks = emptyModBreaks,
342 mg_vect_info = noVectInfo
345 tcCoreDump mod_guts ;
350 mkFakeGroup decls -- Rather clumsy; lots of unused fields
351 = emptyRdrGroup { hs_tyclds = decls }
355 %************************************************************************
357 Type-checking the top level of a module
359 %************************************************************************
362 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
363 -- Returns the variables free in the decls
364 -- Reason: solely to report unused imports and bindings
365 tcRnSrcDecls boot_iface decls
366 = do { -- Do all the declarations
367 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
369 -- Finish simplifying class constraints
371 -- tcSimplifyTop deals with constant or ambiguous InstIds.
372 -- How could there be ambiguous ones? They can only arise if a
373 -- top-level decl falls under the monomorphism restriction
374 -- and no subsequent decl instantiates its type.
376 -- We do this after checkMain, so that we use the type info
377 -- thaat checkMain adds
379 -- We do it with both global and local env in scope:
380 -- * the global env exposes the instances to tcSimplifyTop
381 -- * the local env exposes the local Ids to tcSimplifyTop,
382 -- so that we get better error messages (monomorphism restriction)
383 traceTc (text "Tc8") ;
384 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
386 -- Backsubstitution. This must be done last.
387 -- Even tcSimplifyTop may do some unification.
388 traceTc (text "Tc9") ;
389 let { (tcg_env, _) = tc_envs
390 ; TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
391 tcg_rules = rules, tcg_fords = fords } = tcg_env
392 ; all_binds = binds `unionBags` inst_binds } ;
394 failIfErrsM ; -- Don't zonk if there have been errors
395 -- It's a waste of time; and we may get debug warnings
396 -- about strangely-typed TyCons!
398 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
400 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
401 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
404 tcg_fords = fords' } } ;
406 return (tcg_env' { tcg_binds = tcg_binds tcg_env' })
409 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
410 -- Loops around dealing with each top level inter-splice group
411 -- in turn, until it's dealt with the entire module
412 tc_rn_src_decls boot_details ds
413 = do { let { (first_group, group_tail) = findSplice ds } ;
414 -- If ds is [] we get ([], Nothing)
416 -- Deal with decls up to, but not including, the first splice
417 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
418 -- rnTopSrcDecls fails if there are any errors
420 (tcg_env, tcl_env) <- setGblEnv tcg_env $
421 tcTopSrcDecls boot_details rn_decls ;
423 -- If there is no splice, we're nearly done
424 setEnvs (tcg_env, tcl_env) $
426 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
427 return (tcg_env, tcl_env)
430 -- If there's a splice, we must carry on
431 Just (SpliceDecl splice_expr, rest_ds) -> do {
433 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
436 -- Rename the splice expression, and get its supporting decls
437 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
438 -- checkNoErrs: don't typecheck if renaming failed
439 rnDump (ppr rn_splice_expr) ;
441 -- Execute the splice
442 spliced_decls <- tcSpliceDecls rn_splice_expr ;
444 -- Glue them on the front of the remaining decls and loop
445 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
446 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
451 %************************************************************************
453 Compiling hs-boot source files, and
454 comparing the hi-boot interface with the real thing
456 %************************************************************************
459 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
460 tcRnHsBootDecls decls
461 = do { let { (first_group, group_tail) = findSplice decls }
464 Just stuff -> spliceInHsBootErr stuff
467 -- Rename the declarations
468 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
469 ; setGblEnv tcg_env $ do {
471 -- Todo: check no foreign decls, no rules, no default decls
473 -- Typecheck type/class decls
474 ; traceTc (text "Tc2")
475 ; let tycl_decls = hs_tyclds rn_group
476 ; tcg_env <- tcTyAndClassDecls emptyModDetails tycl_decls
477 ; setGblEnv tcg_env $ do {
479 -- Typecheck instance decls
480 ; traceTc (text "Tc3")
481 ; (tcg_env, inst_infos, _deriv_binds)
482 <- tcInstDecls1 tycl_decls (hs_instds rn_group) (hs_derivds rn_group)
483 ; setGblEnv tcg_env $ do {
485 -- Typecheck value declarations
486 ; traceTc (text "Tc5")
487 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
490 -- No simplification or zonking to do
491 ; traceTc (text "Tc7a")
492 ; gbl_env <- getGblEnv
494 -- Make the final type-env
495 -- Include the dfun_ids so that their type sigs
496 -- are written into the interface file
497 ; let { type_env0 = tcg_type_env gbl_env
498 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
499 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
500 ; dfun_ids = map iDFunId inst_infos }
501 ; return (gbl_env { tcg_type_env = type_env2 })
504 spliceInHsBootErr (SpliceDecl (L loc _), _)
505 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
508 Once we've typechecked the body of the module, we want to compare what
509 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
512 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
513 -- Compare the hi-boot file for this module (if there is one)
514 -- with the type environment we've just come up with
515 -- In the common case where there is no hi-boot file, the list
516 -- of boot_names is empty.
518 -- The bindings we return give bindings for the dfuns defined in the
519 -- hs-boot file, such as $fbEqT = $fEqT
522 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
523 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
524 tcg_type_env = local_type_env, tcg_exports = local_exports })
525 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
526 md_types = boot_type_env, md_exports = boot_exports })
527 | isHsBoot hs_src -- Current module is already a hs-boot file!
531 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
534 -- Check the exports of the boot module, one by one
535 ; mapM_ check_export boot_exports
537 -- Check instance declarations
538 ; mb_dfun_prs <- mapM check_inst boot_insts
539 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds,
540 tcg_type_env = extendTypeEnvWithIds local_type_env boot_dfuns }
541 dfun_prs = catMaybes mb_dfun_prs
542 boot_dfuns = map fst dfun_prs
543 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
544 | (boot_dfun, dfun) <- dfun_prs ]
546 -- Check for no family instances
547 ; unless (null boot_fam_insts) $
548 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
549 "instances in boot files yet...")
550 -- FIXME: Why? The actual comparison is not hard, but what would
551 -- be the equivalent to the dfun bindings returned for class
552 -- instances? We can't easily equate tycons...
556 check_export boot_avail -- boot_avail is exported by the boot iface
557 | name `elem` dfun_names = return ()
558 | isWiredInName name = return () -- No checking for wired-in names. In particular,
559 -- 'error' is handled by a rather gross hack
560 -- (see comments in GHC.Err.hs-boot)
562 -- Check that the actual module exports the same thing
563 | not (null missing_names)
564 = addErrTc (missingBootThing (head missing_names) "exported by")
566 -- If the boot module does not *define* the thing, we are done
567 -- (it simply re-exports it, and names match, so nothing further to do)
568 | isNothing mb_boot_thing = return ()
570 -- Check that the actual module also defines the thing, and
571 -- then compare the definitions
572 | Just real_thing <- lookupTypeEnv local_type_env name
573 = do { let boot_decl = tyThingToIfaceDecl (fromJust mb_boot_thing)
574 real_decl = tyThingToIfaceDecl real_thing
575 ; checkTc (checkBootDecl boot_decl real_decl)
576 (bootMisMatch real_thing boot_decl real_decl) }
577 -- The easiest way to check compatibility is to convert to
578 -- iface syntax, where we already have good comparison functions
581 = addErrTc (missingBootThing name "defined in")
583 name = availName boot_avail
584 mb_boot_thing = lookupTypeEnv boot_type_env name
585 missing_names = case lookupNameEnv local_export_env name of
587 Just avail -> availNames boot_avail `minusList` availNames avail
589 dfun_names = map getName boot_insts
591 local_export_env :: NameEnv AvailInfo
592 local_export_env = availsToNameEnv local_exports
594 check_inst :: Instance -> TcM (Maybe (Id, Id))
595 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
597 = case [dfun | inst <- local_insts,
598 let dfun = instanceDFunId inst,
599 idType dfun `tcEqType` boot_inst_ty ] of
600 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
601 (dfun:_) -> return (Just (local_boot_dfun, dfun))
603 boot_dfun = instanceDFunId boot_inst
604 boot_inst_ty = idType boot_dfun
605 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
609 missingBootThing thing what
610 = ppr thing <+> ptext SLIT("is exported by the hs-boot file, but not")
611 <+> text what <+> ptext SLIT("the module")
613 bootMisMatch thing boot_decl real_decl
614 = vcat [ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file"),
615 ptext SLIT("Main module:") <+> ppr real_decl,
616 ptext SLIT("Boot file: ") <+> ppr boot_decl]
620 2 (ptext SLIT("is defined in the hs-boot file, but not in the module itself"))
624 %************************************************************************
626 Type-checking the top level of a module
628 %************************************************************************
630 tcRnGroup takes a bunch of top-level source-code declarations, and
632 * gets supporting declarations from interface files
635 * and augments the TcGblEnv with the results
637 In Template Haskell it may be called repeatedly for each group of
638 declarations. It expects there to be an incoming TcGblEnv in the
639 monad; it augments it and returns the new TcGblEnv.
642 ------------------------------------------------
643 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
644 -- Fails if there are any errors
646 = do { -- Rename the source decls (with no shadowing; error on duplicates)
647 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls False group ;
649 -- save the renamed syntax, if we want it
651 | Just grp <- tcg_rn_decls tcg_env
652 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
656 -- Dump trace of renaming part
657 rnDump (ppr rn_decls) ;
659 return (tcg_env', rn_decls)
662 ------------------------------------------------
663 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
664 tcTopSrcDecls boot_details
665 (HsGroup { hs_tyclds = tycl_decls,
666 hs_instds = inst_decls,
667 hs_derivds = deriv_decls,
668 hs_fords = foreign_decls,
669 hs_defds = default_decls,
670 hs_ruleds = rule_decls,
671 hs_valds = val_binds })
672 = do { -- Type-check the type and class decls, and all imported decls
673 -- The latter come in via tycl_decls
674 traceTc (text "Tc2") ;
676 tcg_env <- tcTyAndClassDecls boot_details tycl_decls ;
677 -- If there are any errors, tcTyAndClassDecls fails here
679 -- Make these type and class decls available to stuff slurped from interface files
680 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
683 setGblEnv tcg_env $ do {
684 -- Source-language instances, including derivings,
685 -- and import the supporting declarations
686 traceTc (text "Tc3") ;
687 (tcg_env, inst_infos, deriv_binds)
688 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
689 setGblEnv tcg_env $ do {
691 -- Foreign import declarations next. No zonking necessary
692 -- here; we can tuck them straight into the global environment.
693 traceTc (text "Tc4") ;
694 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
695 tcExtendGlobalValEnv fi_ids $ do {
697 -- Default declarations
698 traceTc (text "Tc4a") ;
699 default_tys <- tcDefaults default_decls ;
700 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
702 -- Value declarations next
703 -- We also typecheck any extra binds that came out
704 -- of the "deriving" process (deriv_binds)
705 traceTc (text "Tc5") ;
706 (tc_val_binds, tcl_env) <- tcTopBinds val_binds ;
707 setLclTypeEnv tcl_env $ do {
709 -- Now GHC-generated derived bindings and generics.
710 -- Do not generate warnings from compiler-generated code.
711 (tc_deriv_binds, tcl_env) <- discardWarnings $
712 tcTopBinds deriv_binds ;
714 -- Second pass over class and instance declarations,
715 traceTc (text "Tc6") ;
716 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $ tcInstDecls2 tycl_decls inst_infos ;
717 showLIE (text "after instDecls2") ;
720 -- They need to be zonked, so we return them
721 traceTc (text "Tc7") ;
722 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
725 rules <- tcRules rule_decls ;
728 traceTc (text "Tc7a") ;
729 tcg_env <- getGblEnv ;
730 let { all_binds = tc_val_binds `unionBags`
731 tc_deriv_binds `unionBags`
732 inst_binds `unionBags`
735 -- Extend the GblEnv with the (as yet un-zonked)
736 -- bindings, rules, foreign decls
737 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
738 tcg_rules = tcg_rules tcg_env ++ rules,
739 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
740 return (tcg_env', tcl_env)
745 %************************************************************************
749 %************************************************************************
752 checkMain :: TcM TcGblEnv
753 -- If we are in module Main, check that 'main' is defined.
755 = do { tcg_env <- getGblEnv ;
757 check_main dflags tcg_env
760 check_main dflags tcg_env
762 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
766 = do { mb_main <- lookupSrcOcc_maybe main_fn
767 -- Check that 'main' is in scope
768 -- It might be imported from another module!
770 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
775 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
776 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
777 -- :Main.main :: IO () = runMainIO main
779 ; (main_expr, ty) <- addErrCtxt mainCtxt $
780 setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
783 -- See Note [Root-main Id]
784 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
785 (mkVarOccFS FSLIT("main"))
786 (getSrcSpan main_name)
787 ; root_main_id = Id.mkExportedLocalId root_main_name ty
788 ; main_bind = noLoc (VarBind root_main_id main_expr) }
790 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
792 tcg_dus = tcg_dus tcg_env
793 `plusDU` usesOnly (unitFV main_name)
794 -- Record the use of 'main', so that we don't
795 -- complain about it being defined but not used
799 mod = tcg_mod tcg_env
800 main_mod = mainModIs dflags
801 main_is_flag = mainFunIs dflags
803 main_fn = case main_is_flag of
804 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
805 Nothing -> main_RDR_Unqual
807 complain_no_main | ghcLink dflags == LinkInMemory = return ()
808 | otherwise = failWithTc noMainMsg
809 -- In interactive mode, don't worry about the absence of 'main'
810 -- In other modes, fail altogether, so that we don't go on
811 -- and complain a second time when processing the export list.
813 mainCtxt = ptext SLIT("When checking the type of the") <+> pp_main_fn
814 noMainMsg = ptext SLIT("The") <+> pp_main_fn
815 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
816 pp_main_fn | isJust main_is_flag = ptext SLIT("main function") <+> quotes (ppr main_fn)
817 | otherwise = ptext SLIT("function") <+> quotes (ppr main_fn)
822 The function that the RTS invokes is always :Main.main, which we call
823 root_main_id. (Because GHC allows the user to have a module not
824 called Main as the main module, we can't rely on the main function
825 being called "Main.main". That's why root_main_id has a fixed module
828 This is unusual: it's a LocalId whose Name has a Module from another
829 module. Tiresomely, we must filter it out again in MkIface, les we
830 get two defns for 'main' in the interface file!
833 %*********************************************************
837 %*********************************************************
841 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
842 setInteractiveContext hsc_env icxt thing_inside
843 = let -- Initialise the tcg_inst_env with instances from all home modules.
844 -- This mimics the more selective call to hptInstances in tcRnModule.
845 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
847 updGblEnv (\env -> env {
848 tcg_rdr_env = ic_rn_gbl_env icxt,
849 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
850 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
854 tcExtendGhciEnv (ic_tmp_ids icxt) $
855 -- tcExtendGhciEnv does lots:
856 -- - it extends the local type env (tcl_env) with the given Ids,
857 -- - it extends the local rdr env (tcl_rdr) with the Names from
859 -- - it adds the free tyvars of the Ids to the tcl_tyvars
862 -- later ids in ic_tmp_ids must shadow earlier ones with the same
863 -- OccName, and tcExtendIdEnv implements this behaviour.
865 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
872 -> InteractiveContext
874 -> IO (Maybe ([Id], LHsExpr Id))
875 -- The returned [Id] is the list of new Ids bound by
876 -- this statement. It can be used to extend the
877 -- InteractiveContext via extendInteractiveContext.
879 -- The returned TypecheckedHsExpr is of type IO [ () ],
880 -- a list of the bound values, coerced to ().
882 tcRnStmt hsc_env ictxt rdr_stmt
883 = initTcPrintErrors hsc_env iNTERACTIVE $
884 setInteractiveContext hsc_env ictxt $ do {
886 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
887 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
888 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
890 rnDump (ppr rn_stmt) ;
892 -- The real work is done here
893 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
894 zonked_expr <- zonkTopLExpr tc_expr ;
895 zonked_ids <- zonkTopBndrs bound_ids ;
897 -- None of the Ids should be of unboxed type, because we
898 -- cast them all to HValues in the end!
899 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
901 traceTc (text "tcs 1") ;
902 let { -- (a) Make all the bound ids "global" ids, now that
903 -- they're notionally top-level bindings. This is
904 -- important: otherwise when we come to compile an expression
905 -- using these ids later, the byte code generator will consider
906 -- the occurrences to be free rather than global.
908 -- (b) Tidy their types; this is important, because :info may
909 -- ask to look at them, and :info expects the things it looks
910 -- up to have tidy types
911 global_ids = map globaliseAndTidy zonked_ids ;
913 {- ---------------------------------------------
914 At one stage I removed any shadowed bindings from the type_env;
915 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
916 However, with Template Haskell they aren't necessarily inaccessible. Consider this
918 Prelude> let f n = n * 2 :: Int
919 Prelude> fName <- runQ [| f |]
920 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
922 Prelude> let f n = n * 3 :: Int
923 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
924 In the last line we use 'fName', which resolves to the *first* 'f'
925 in scope. If we delete it from the type env, GHCi crashes because
926 it doesn't expect that.
928 Hence this code is commented out
930 -------------------------------------------------- -}
933 dumpOptTcRn Opt_D_dump_tc
934 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
935 text "Typechecked expr" <+> ppr zonked_expr]) ;
937 returnM (global_ids, zonked_expr)
940 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
941 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
943 globaliseAndTidy :: Id -> Id
945 -- Give the Id a Global Name, and tidy its type
946 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
948 tidy_type = tidyTopType (idType id)
951 Here is the grand plan, implemented in tcUserStmt
953 What you type The IO [HValue] that hscStmt returns
954 ------------- ------------------------------------
955 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
958 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
961 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
962 [NB: result not printed] bindings: [it]
964 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
965 result showable) bindings: [it]
967 expr (of non-IO type,
968 result not showable) ==> error
972 ---------------------------
973 type PlanResult = ([Id], LHsExpr Id)
974 type Plan = TcM PlanResult
976 runPlans :: [Plan] -> TcM PlanResult
977 -- Try the plans in order. If one fails (by raising an exn), try the next.
978 -- If one succeeds, take it.
979 runPlans [] = panic "runPlans"
981 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
984 mkPlan :: LStmt Name -> TcM PlanResult
985 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
986 = do { uniq <- newUnique -- is treated very specially
987 ; let fresh_it = itName uniq
988 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
989 matches = [mkMatch [] expr emptyLocalBinds]
990 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
991 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
992 (HsVar bindIOName) noSyntaxExpr
993 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
994 (HsVar thenIOName) placeHolderType
997 -- [it <- e; print it] but not if it::()
999 -- [let it = e; print it]
1000 ; runPlans [ -- Plan A
1001 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1002 ; it_ty <- zonkTcType (idType it_id)
1003 ; ifM (isUnitTy it_ty) failM
1006 -- Plan B; a naked bind statment
1007 tcGhciStmts [bind_stmt],
1009 -- Plan C; check that the let-binding is typeable all by itself.
1010 -- If not, fail; if so, try to print it.
1011 -- The two-step process avoids getting two errors: one from
1012 -- the expression itself, and one from the 'print it' part
1013 -- This two-step story is very clunky, alas
1014 do { checkNoErrs (tcGhciStmts [let_stmt])
1015 --- checkNoErrs defeats the error recovery of let-bindings
1016 ; tcGhciStmts [let_stmt, print_it] }
1019 mkPlan stmt@(L loc (BindStmt {}))
1020 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1021 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1022 (HsVar thenIOName) placeHolderType
1024 ; print_bind_result <- doptM Opt_PrintBindResult
1025 ; let print_plan = do
1026 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1027 ; v_ty <- zonkTcType (idType v_id)
1028 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
1032 -- [stmt; print v] but not if v::()
1034 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1035 [tcGhciStmts [stmt]])
1039 = tcGhciStmts [stmt]
1041 ---------------------------
1042 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1044 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1045 ret_id <- tcLookupId returnIOName ; -- return @ IO
1047 io_ty = mkTyConApp ioTyCon [] ;
1048 ret_ty = mkListTy unitTy ;
1049 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1050 tc_io_stmts stmts = tcStmts DoExpr (tcDoStmt io_ty) stmts
1051 (emptyRefinement, io_ret_ty) ;
1053 names = map unLoc (collectLStmtsBinders stmts) ;
1055 -- mk_return builds the expression
1056 -- returnIO @ [()] [coerce () x, .., coerce () z]
1058 -- Despite the inconvenience of building the type applications etc,
1059 -- this *has* to be done in type-annotated post-typecheck form
1060 -- because we are going to return a list of *polymorphic* values
1061 -- coerced to type (). If we built a *source* stmt
1062 -- return [coerce x, ..., coerce z]
1063 -- then the type checker would instantiate x..z, and we wouldn't
1064 -- get their *polymorphic* values. (And we'd get ambiguity errs
1065 -- if they were overloaded, since they aren't applied to anything.)
1066 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1067 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1068 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1072 -- OK, we're ready to typecheck the stmts
1073 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1074 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1075 mappM tcLookupId names ;
1076 -- Look up the names right in the middle,
1077 -- where they will all be in scope
1079 -- Simplify the context
1080 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1081 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1082 -- checkNoErrs ensures that the plan fails if context redn fails
1084 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1085 return (ids, mkHsDictLet const_binds $
1086 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1091 tcRnExpr just finds the type of an expression
1095 -> InteractiveContext
1098 tcRnExpr hsc_env ictxt rdr_expr
1099 = initTcPrintErrors hsc_env iNTERACTIVE $
1100 setInteractiveContext hsc_env ictxt $ do {
1102 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1105 -- Now typecheck the expression;
1106 -- it might have a rank-2 type (e.g. :t runST)
1107 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1108 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1109 tcSimplifyInteractive lie_top ;
1111 let { all_expr_ty = mkForAllTys qtvs $
1112 mkFunTys (map (idType . instToId) dict_insts) $
1114 zonkTcType all_expr_ty
1117 smpl_doc = ptext SLIT("main expression")
1120 tcRnType just finds the kind of a type
1124 -> InteractiveContext
1127 tcRnType hsc_env ictxt rdr_type
1128 = initTcPrintErrors hsc_env iNTERACTIVE $
1129 setInteractiveContext hsc_env ictxt $ do {
1131 rn_type <- rnLHsType doc rdr_type ;
1134 -- Now kind-check the type
1135 (ty', kind) <- kcHsType rn_type ;
1139 doc = ptext SLIT("In GHCi input")
1145 %************************************************************************
1147 More GHCi stuff, to do with browsing and getting info
1149 %************************************************************************
1153 -- ASSUMES that the module is either in the HomePackageTable or is
1154 -- a package module with an interface on disk. If neither of these is
1155 -- true, then the result will be an error indicating the interface
1156 -- could not be found.
1157 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1158 getModuleExports hsc_env mod
1161 checkMods = ic_toplev_scope ic ++ ic_exports ic
1163 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1165 -- Get the export avail info and also load all orphan and family-instance
1166 -- modules. Finally, check that the family instances of all modules in the
1167 -- interactive context are consistent (these modules are in the second
1169 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1170 tcGetModuleExports mod directlyImpMods
1171 = do { let doc = ptext SLIT("context for compiling statements")
1172 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1174 -- Load any orphan-module and family instance-module
1175 -- interfaces, so their instances are visible.
1176 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1177 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1179 -- Check that the family instances of all directly loaded
1180 -- modules are consistent.
1181 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1183 ; ifaceExportNames (mi_exports iface)
1186 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1187 tcRnLookupRdrName hsc_env rdr_name
1188 = initTcPrintErrors hsc_env iNTERACTIVE $
1189 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1190 lookup_rdr_name rdr_name
1192 lookup_rdr_name rdr_name = do {
1193 -- If the identifier is a constructor (begins with an
1194 -- upper-case letter), then we need to consider both
1195 -- constructor and type class identifiers.
1196 let { rdr_names = dataTcOccs rdr_name } ;
1198 -- results :: [Either Messages Name]
1199 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1201 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1202 -- The successful lookups will be (Just name)
1203 let { (warns_s, good_names) = unzip [ (msgs, name)
1204 | (msgs, Just name) <- results] ;
1205 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1207 -- Fail if nothing good happened, else add warnings
1208 if null good_names then
1209 -- No lookup succeeded, so
1210 -- pick the first error message and report it
1211 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1212 -- while the other is "X is not in scope",
1213 -- we definitely want the former; but we might pick the latter
1214 do { addMessages (head errs_s) ; failM }
1215 else -- Add deprecation warnings
1216 mapM_ addMessages warns_s ;
1221 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1222 tcRnLookupName hsc_env name
1223 = initTcPrintErrors hsc_env iNTERACTIVE $
1224 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1225 tcRnLookupName' name
1227 -- To look up a name we have to look in the local environment (tcl_lcl)
1228 -- as well as the global environment, which is what tcLookup does.
1229 -- But we also want a TyThing, so we have to convert:
1231 tcRnLookupName' :: Name -> TcRn TyThing
1232 tcRnLookupName' name = do
1233 tcthing <- tcLookup name
1235 AGlobal thing -> return thing
1236 ATcId{tct_id=id} -> return (AnId id)
1237 _ -> panic "tcRnLookupName'"
1239 tcRnGetInfo :: HscEnv
1241 -> IO (Maybe (TyThing, Fixity, [Instance]))
1243 -- Used to implemnent :info in GHCi
1245 -- Look up a RdrName and return all the TyThings it might be
1246 -- A capitalised RdrName is given to us in the DataName namespace,
1247 -- but we want to treat it as *both* a data constructor
1248 -- *and* as a type or class constructor;
1249 -- hence the call to dataTcOccs, and we return up to two results
1250 tcRnGetInfo hsc_env name
1251 = initTcPrintErrors hsc_env iNTERACTIVE $
1252 let ictxt = hsc_IC hsc_env in
1253 setInteractiveContext hsc_env ictxt $ do
1255 -- Load the interface for all unqualified types and classes
1256 -- That way we will find all the instance declarations
1257 -- (Packages have not orphan modules, and we assume that
1258 -- in the home package all relevant modules are loaded.)
1259 loadUnqualIfaces ictxt
1261 thing <- tcRnLookupName' name
1262 fixity <- lookupFixityRn name
1263 ispecs <- lookupInsts thing
1264 return (thing, fixity, ispecs)
1266 lookupInsts :: TyThing -> TcM [Instance]
1267 lookupInsts (AClass cls)
1268 = do { inst_envs <- tcGetInstEnvs
1269 ; return (classInstances inst_envs cls) }
1271 lookupInsts (ATyCon tc)
1272 = do { eps <- getEps -- Load all instances for all classes that are
1273 -- in the type environment (which are all the ones
1274 -- we've seen in any interface file so far)
1275 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1277 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1278 , let dfun = instanceDFunId ispec
1281 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1282 tc_name = tyConName tc
1284 lookupInsts other = return []
1286 loadUnqualIfaces :: InteractiveContext -> TcM ()
1287 -- Load the home module for everything that is in scope unqualified
1288 -- This is so that we can accurately report the instances for
1290 loadUnqualIfaces ictxt
1292 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1294 unqual_mods = [ nameModule name
1295 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1296 let name = gre_name gre,
1297 not (isInternalName name),
1298 isTcOcc (nameOccName name), -- Types and classes only
1299 unQualOK gre ] -- In scope unqualified
1300 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1304 %************************************************************************
1308 %************************************************************************
1311 rnDump :: SDoc -> TcRn ()
1312 -- Dump, with a banner, if -ddump-rn
1313 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1315 tcDump :: TcGblEnv -> TcRn ()
1317 = do { dflags <- getDOpts ;
1319 -- Dump short output if -ddump-types or -ddump-tc
1320 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1321 (dumpTcRn short_dump) ;
1323 -- Dump bindings if -ddump-tc
1324 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1327 short_dump = pprTcGblEnv env
1328 full_dump = pprLHsBinds (tcg_binds env)
1329 -- NB: foreign x-d's have undefined's in their types;
1330 -- hence can't show the tc_fords
1333 = do { dflags <- getDOpts ;
1334 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1335 (dumpTcRn (pprModGuts mod_guts)) ;
1337 -- Dump bindings if -ddump-tc
1338 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1340 full_dump = pprCoreBindings (mg_binds mod_guts)
1342 -- It's unpleasant having both pprModGuts and pprModDetails here
1343 pprTcGblEnv :: TcGblEnv -> SDoc
1344 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1346 tcg_fam_insts = fam_insts,
1348 tcg_imports = imports })
1349 = vcat [ ppr_types insts type_env
1350 , ppr_tycons fam_insts type_env
1352 , ppr_fam_insts fam_insts
1353 , vcat (map ppr rules)
1354 , ppr_gen_tycons (typeEnvTyCons type_env)
1355 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1356 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1358 pprModGuts :: ModGuts -> SDoc
1359 pprModGuts (ModGuts { mg_types = type_env,
1361 = vcat [ ppr_types [] type_env,
1364 ppr_types :: [Instance] -> TypeEnv -> SDoc
1365 ppr_types insts type_env
1366 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1368 dfun_ids = map instanceDFunId insts
1369 ids = [id | id <- typeEnvIds type_env, want_sig id]
1370 want_sig id | opt_PprStyle_Debug = True
1371 | otherwise = isLocalId id &&
1372 isExternalName (idName id) &&
1373 not (id `elem` dfun_ids)
1374 -- isLocalId ignores data constructors, records selectors etc.
1375 -- The isExternalName ignores local dictionary and method bindings
1376 -- that the type checker has invented. Top-level user-defined things
1377 -- have External names.
1379 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1380 ppr_tycons fam_insts type_env
1381 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1383 fi_tycons = map famInstTyCon fam_insts
1384 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1385 want_tycon tycon | opt_PprStyle_Debug = True
1386 | otherwise = not (isImplicitTyCon tycon) &&
1387 isExternalName (tyConName tycon) &&
1388 not (tycon `elem` fi_tycons)
1390 ppr_insts :: [Instance] -> SDoc
1391 ppr_insts [] = empty
1392 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1394 ppr_fam_insts :: [FamInst] -> SDoc
1395 ppr_fam_insts [] = empty
1396 ppr_fam_insts fam_insts =
1397 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1399 ppr_sigs :: [Var] -> SDoc
1401 -- Print type signatures; sort by OccName
1402 = vcat (map ppr_sig (sortLe le_sig ids))
1404 le_sig id1 id2 = getOccName id1 <= getOccName id2
1405 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1407 ppr_tydecls :: [TyCon] -> SDoc
1409 -- Print type constructor info; sort by OccName
1410 = vcat (map ppr_tycon (sortLe le_sig tycons))
1412 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1414 | isCoercionTyCon tycon = ptext SLIT("coercion") <+> ppr tycon
1415 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1417 ppr_rules :: [CoreRule] -> SDoc
1418 ppr_rules [] = empty
1419 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1420 nest 4 (pprRules rs),
1423 ppr_gen_tycons [] = empty
1424 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1425 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]