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 )
61 import TcUnify ( withBox )
95 import {- Kind parts of -} Type
97 import Foreign.Ptr( Ptr )
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 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
294 tc_envs <- extendGlobalRdrEnvRn False avails
295 emptyFsEnv {- no fixity decls -} ;
297 setEnvs tc_envs $ do {
299 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
301 -- Dump trace of renaming part
302 rnDump (ppr rn_decls) ;
304 -- Typecheck them all together so that
305 -- any mutually recursive types are done right
306 tcg_env <- tcTyAndClassDecls emptyModDetails rn_decls ;
307 -- Make the new type env available to stuff slurped from interface files
309 setGblEnv tcg_env $ do {
311 -- Now the core bindings
312 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
316 bndrs = bindersOfBinds core_binds ;
317 my_exports = map (Avail . idName) bndrs ;
318 -- ToDo: export the data types also?
320 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
322 mod_guts = ModGuts { mg_module = this_mod,
324 mg_used_names = emptyNameSet, -- ToDo: compute usage
325 mg_dir_imps = emptyModuleEnv, -- ??
326 mg_deps = noDependencies, -- ??
327 mg_exports = my_exports,
328 mg_types = final_type_env,
329 mg_insts = tcg_insts tcg_env,
330 mg_fam_insts = tcg_fam_insts tcg_env,
331 mg_inst_env = tcg_inst_env tcg_env,
332 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
334 mg_binds = core_binds,
337 mg_rdr_env = emptyGlobalRdrEnv,
338 mg_fix_env = emptyFixityEnv,
339 mg_deprecs = NoDeprecs,
340 mg_foreign = NoStubs,
341 mg_hpc_info = emptyHpcInfo False,
342 mg_modBreaks = emptyModBreaks,
343 mg_vect_info = noVectInfo
346 tcCoreDump mod_guts ;
351 mkFakeGroup decls -- Rather clumsy; lots of unused fields
352 = emptyRdrGroup { hs_tyclds = decls }
356 %************************************************************************
358 Type-checking the top level of a module
360 %************************************************************************
363 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
364 -- Returns the variables free in the decls
365 -- Reason: solely to report unused imports and bindings
366 tcRnSrcDecls boot_iface decls
367 = do { -- Do all the declarations
368 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
370 -- Finish simplifying class constraints
372 -- tcSimplifyTop deals with constant or ambiguous InstIds.
373 -- How could there be ambiguous ones? They can only arise if a
374 -- top-level decl falls under the monomorphism restriction
375 -- and no subsequent decl instantiates its type.
377 -- We do this after checkMain, so that we use the type info
378 -- thaat checkMain adds
380 -- We do it with both global and local env in scope:
381 -- * the global env exposes the instances to tcSimplifyTop
382 -- * the local env exposes the local Ids to tcSimplifyTop,
383 -- so that we get better error messages (monomorphism restriction)
384 traceTc (text "Tc8") ;
385 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
387 -- Backsubstitution. This must be done last.
388 -- Even tcSimplifyTop may do some unification.
389 traceTc (text "Tc9") ;
390 let { (tcg_env, _) = tc_envs
391 ; TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
392 tcg_rules = rules, tcg_fords = fords } = tcg_env
393 ; all_binds = binds `unionBags` inst_binds } ;
395 failIfErrsM ; -- Don't zonk if there have been errors
396 -- It's a waste of time; and we may get debug warnings
397 -- about strangely-typed TyCons!
399 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
401 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
402 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
405 tcg_fords = fords' } } ;
407 return (tcg_env' { tcg_binds = tcg_binds tcg_env' })
410 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
411 -- Loops around dealing with each top level inter-splice group
412 -- in turn, until it's dealt with the entire module
413 tc_rn_src_decls boot_details ds
414 = do { let { (first_group, group_tail) = findSplice ds } ;
415 -- If ds is [] we get ([], Nothing)
417 -- Deal with decls up to, but not including, the first splice
418 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
419 -- rnTopSrcDecls fails if there are any errors
421 (tcg_env, tcl_env) <- setGblEnv tcg_env $
422 tcTopSrcDecls boot_details rn_decls ;
424 -- If there is no splice, we're nearly done
425 setEnvs (tcg_env, tcl_env) $
427 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
428 return (tcg_env, tcl_env)
431 -- If there's a splice, we must carry on
432 Just (SpliceDecl splice_expr, rest_ds) -> do {
434 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
437 -- Rename the splice expression, and get its supporting decls
438 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
439 -- checkNoErrs: don't typecheck if renaming failed
440 rnDump (ppr rn_splice_expr) ;
442 -- Execute the splice
443 spliced_decls <- tcSpliceDecls rn_splice_expr ;
445 -- Glue them on the front of the remaining decls and loop
446 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
447 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
452 %************************************************************************
454 Compiling hs-boot source files, and
455 comparing the hi-boot interface with the real thing
457 %************************************************************************
460 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
461 tcRnHsBootDecls decls
462 = do { let { (first_group, group_tail) = findSplice decls }
465 Just stuff -> spliceInHsBootErr stuff
468 -- Rename the declarations
469 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
470 ; setGblEnv tcg_env $ do {
472 -- Todo: check no foreign decls, no rules, no default decls
474 -- Typecheck type/class decls
475 ; traceTc (text "Tc2")
476 ; let tycl_decls = hs_tyclds rn_group
477 ; tcg_env <- tcTyAndClassDecls emptyModDetails tycl_decls
478 ; setGblEnv tcg_env $ do {
480 -- Typecheck instance decls
481 ; traceTc (text "Tc3")
482 ; (tcg_env, inst_infos, _deriv_binds)
483 <- tcInstDecls1 tycl_decls (hs_instds rn_group) (hs_derivds rn_group)
484 ; setGblEnv tcg_env $ do {
486 -- Typecheck value declarations
487 ; traceTc (text "Tc5")
488 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
491 -- No simplification or zonking to do
492 ; traceTc (text "Tc7a")
493 ; gbl_env <- getGblEnv
495 -- Make the final type-env
496 -- Include the dfun_ids so that their type sigs
497 -- are written into the interface file
498 ; let { type_env0 = tcg_type_env gbl_env
499 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
500 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
501 ; dfun_ids = map iDFunId inst_infos }
502 ; return (gbl_env { tcg_type_env = type_env2 })
505 spliceInHsBootErr (SpliceDecl (L loc _), _)
506 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
509 Once we've typechecked the body of the module, we want to compare what
510 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
513 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
514 -- Compare the hi-boot file for this module (if there is one)
515 -- with the type environment we've just come up with
516 -- In the common case where there is no hi-boot file, the list
517 -- of boot_names is empty.
519 -- The bindings we return give bindings for the dfuns defined in the
520 -- hs-boot file, such as $fbEqT = $fEqT
523 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
524 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
525 tcg_type_env = local_type_env, tcg_exports = local_exports })
526 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
527 md_types = boot_type_env, md_exports = boot_exports })
528 | isHsBoot hs_src -- Current module is already a hs-boot file!
532 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
535 -- Check the exports of the boot module, one by one
536 ; mapM_ check_export boot_exports
538 -- Check instance declarations
539 ; mb_dfun_prs <- mapM check_inst boot_insts
540 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds,
541 tcg_type_env = extendTypeEnvWithIds local_type_env boot_dfuns }
542 dfun_prs = catMaybes mb_dfun_prs
543 boot_dfuns = map fst dfun_prs
544 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
545 | (boot_dfun, dfun) <- dfun_prs ]
547 -- Check for no family instances
548 ; unless (null boot_fam_insts) $
549 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
550 "instances in boot files yet...")
551 -- FIXME: Why? The actual comparison is not hard, but what would
552 -- be the equivalent to the dfun bindings returned for class
553 -- instances? We can't easily equate tycons...
557 check_export boot_avail -- boot_avail is exported by the boot iface
558 | name `elem` dfun_names = return ()
559 | isWiredInName name = return () -- No checking for wired-in names. In particular,
560 -- 'error' is handled by a rather gross hack
561 -- (see comments in GHC.Err.hs-boot)
563 -- Check that the actual module exports the same thing
564 | not (null missing_names)
565 = addErrTc (missingBootThing (head missing_names) "exported by")
567 -- If the boot module does not *define* the thing, we are done
568 -- (it simply re-exports it, and names match, so nothing further to do)
569 | isNothing mb_boot_thing = return ()
571 -- Check that the actual module also defines the thing, and
572 -- then compare the definitions
573 | Just real_thing <- lookupTypeEnv local_type_env name
574 = do { let boot_decl = tyThingToIfaceDecl (fromJust mb_boot_thing)
575 real_decl = tyThingToIfaceDecl real_thing
576 ; checkTc (checkBootDecl boot_decl real_decl)
577 (bootMisMatch real_thing boot_decl real_decl) }
578 -- The easiest way to check compatibility is to convert to
579 -- iface syntax, where we already have good comparison functions
582 = addErrTc (missingBootThing name "defined in")
584 name = availName boot_avail
585 mb_boot_thing = lookupTypeEnv boot_type_env name
586 missing_names = case lookupNameEnv local_export_env name of
588 Just avail -> availNames boot_avail `minusList` availNames avail
590 dfun_names = map getName boot_insts
592 local_export_env :: NameEnv AvailInfo
593 local_export_env = availsToNameEnv local_exports
595 check_inst :: Instance -> TcM (Maybe (Id, Id))
596 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
598 = case [dfun | inst <- local_insts,
599 let dfun = instanceDFunId inst,
600 idType dfun `tcEqType` boot_inst_ty ] of
601 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
602 (dfun:_) -> return (Just (local_boot_dfun, dfun))
604 boot_dfun = instanceDFunId boot_inst
605 boot_inst_ty = idType boot_dfun
606 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
610 missingBootThing thing what
611 = ppr thing <+> ptext SLIT("is exported by the hs-boot file, but not")
612 <+> text what <+> ptext SLIT("the module")
614 bootMisMatch thing boot_decl real_decl
615 = vcat [ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file"),
616 ptext SLIT("Main module:") <+> ppr real_decl,
617 ptext SLIT("Boot file: ") <+> ppr boot_decl]
621 2 (ptext SLIT("is defined in the hs-boot file, but not in the module itself"))
625 %************************************************************************
627 Type-checking the top level of a module
629 %************************************************************************
631 tcRnGroup takes a bunch of top-level source-code declarations, and
633 * gets supporting declarations from interface files
636 * and augments the TcGblEnv with the results
638 In Template Haskell it may be called repeatedly for each group of
639 declarations. It expects there to be an incoming TcGblEnv in the
640 monad; it augments it and returns the new TcGblEnv.
643 ------------------------------------------------
644 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
645 -- Fails if there are any errors
647 = do { -- Rename the source decls (with no shadowing; error on duplicates)
648 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls False group ;
650 -- save the renamed syntax, if we want it
652 | Just grp <- tcg_rn_decls tcg_env
653 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
657 -- Dump trace of renaming part
658 rnDump (ppr rn_decls) ;
660 return (tcg_env', rn_decls)
663 ------------------------------------------------
664 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
665 tcTopSrcDecls boot_details
666 (HsGroup { hs_tyclds = tycl_decls,
667 hs_instds = inst_decls,
668 hs_derivds = deriv_decls,
669 hs_fords = foreign_decls,
670 hs_defds = default_decls,
671 hs_ruleds = rule_decls,
672 hs_valds = val_binds })
673 = do { -- Type-check the type and class decls, and all imported decls
674 -- The latter come in via tycl_decls
675 traceTc (text "Tc2") ;
677 tcg_env <- tcTyAndClassDecls boot_details tycl_decls ;
678 -- If there are any errors, tcTyAndClassDecls fails here
680 -- Make these type and class decls available to stuff slurped from interface files
681 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
684 setGblEnv tcg_env $ do {
685 -- Source-language instances, including derivings,
686 -- and import the supporting declarations
687 traceTc (text "Tc3") ;
688 (tcg_env, inst_infos, deriv_binds)
689 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
690 setGblEnv tcg_env $ do {
692 -- Foreign import declarations next. No zonking necessary
693 -- here; we can tuck them straight into the global environment.
694 traceTc (text "Tc4") ;
695 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
696 tcExtendGlobalValEnv fi_ids $ do {
698 -- Default declarations
699 traceTc (text "Tc4a") ;
700 default_tys <- tcDefaults default_decls ;
701 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
703 -- Value declarations next
704 -- We also typecheck any extra binds that came out
705 -- of the "deriving" process (deriv_binds)
706 traceTc (text "Tc5") ;
707 (tc_val_binds, tcl_env) <- tcTopBinds val_binds ;
708 setLclTypeEnv tcl_env $ do {
710 -- Now GHC-generated derived bindings and generics.
711 -- Do not generate warnings from compiler-generated code.
712 (tc_deriv_binds, tcl_env) <- discardWarnings $
713 tcTopBinds deriv_binds ;
715 -- Second pass over class and instance declarations,
716 traceTc (text "Tc6") ;
717 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $ tcInstDecls2 tycl_decls inst_infos ;
718 showLIE (text "after instDecls2") ;
721 -- They need to be zonked, so we return them
722 traceTc (text "Tc7") ;
723 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
726 rules <- tcRules rule_decls ;
729 traceTc (text "Tc7a") ;
730 tcg_env <- getGblEnv ;
731 let { all_binds = tc_val_binds `unionBags`
732 tc_deriv_binds `unionBags`
733 inst_binds `unionBags`
736 -- Extend the GblEnv with the (as yet un-zonked)
737 -- bindings, rules, foreign decls
738 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
739 tcg_rules = tcg_rules tcg_env ++ rules,
740 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
741 return (tcg_env', tcl_env)
746 %************************************************************************
750 %************************************************************************
753 checkMain :: TcM TcGblEnv
754 -- If we are in module Main, check that 'main' is defined.
756 = do { tcg_env <- getGblEnv ;
758 check_main dflags tcg_env
761 check_main dflags tcg_env
763 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
767 = do { mb_main <- lookupSrcOcc_maybe main_fn
768 -- Check that 'main' is in scope
769 -- It might be imported from another module!
771 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
776 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
777 ; let loc = srcLocSpan (getSrcLoc main_name)
778 ; ioTyCon <- tcLookupTyCon ioTyConName
779 ; (main_expr, res_ty)
780 <- addErrCtxt mainCtxt $
781 withBox liftedTypeKind $ \res_ty ->
782 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
784 -- See Note [Root-main Id]
785 -- Construct the binding
786 -- :Main.main :: IO res_ty = runMainIO res_ty main
787 ; run_main_id <- tcLookupId runMainIOName
788 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
789 (mkVarOccFS FSLIT("main"))
790 (getSrcSpan main_name)
791 ; root_main_id = Id.mkExportedLocalId root_main_name
792 (mkTyConApp ioTyCon [res_ty])
793 ; co = mkWpTyApps [res_ty]
794 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
795 ; main_bind = noLoc (VarBind root_main_id rhs) }
797 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
799 tcg_dus = tcg_dus tcg_env
800 `plusDU` usesOnly (unitFV main_name)
801 -- Record the use of 'main', so that we don't
802 -- complain about it being defined but not used
806 mod = tcg_mod tcg_env
807 main_mod = mainModIs dflags
808 main_is_flag = mainFunIs dflags
810 main_fn = case main_is_flag of
811 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
812 Nothing -> main_RDR_Unqual
814 complain_no_main | ghcLink dflags == LinkInMemory = return ()
815 | otherwise = failWithTc noMainMsg
816 -- In interactive mode, don't worry about the absence of 'main'
817 -- In other modes, fail altogether, so that we don't go on
818 -- and complain a second time when processing the export list.
820 mainCtxt = ptext SLIT("When checking the type of the") <+> pp_main_fn
821 noMainMsg = ptext SLIT("The") <+> pp_main_fn
822 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
823 pp_main_fn | isJust main_is_flag = ptext SLIT("main function") <+> quotes (ppr main_fn)
824 | otherwise = ptext SLIT("function") <+> quotes (ppr main_fn)
829 The function that the RTS invokes is always :Main.main, which we call
830 root_main_id. (Because GHC allows the user to have a module not
831 called Main as the main module, we can't rely on the main function
832 being called "Main.main". That's why root_main_id has a fixed module
835 This is unusual: it's a LocalId whose Name has a Module from another
836 module. Tiresomely, we must filter it out again in MkIface, les we
837 get two defns for 'main' in the interface file!
840 %*********************************************************
844 %*********************************************************
848 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
849 setInteractiveContext hsc_env icxt thing_inside
850 = let -- Initialise the tcg_inst_env with instances from all home modules.
851 -- This mimics the more selective call to hptInstances in tcRnModule.
852 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
854 updGblEnv (\env -> env {
855 tcg_rdr_env = ic_rn_gbl_env icxt,
856 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
857 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
861 tcExtendGhciEnv (ic_tmp_ids icxt) $
862 -- tcExtendGhciEnv does lots:
863 -- - it extends the local type env (tcl_env) with the given Ids,
864 -- - it extends the local rdr env (tcl_rdr) with the Names from
866 -- - it adds the free tyvars of the Ids to the tcl_tyvars
869 -- later ids in ic_tmp_ids must shadow earlier ones with the same
870 -- OccName, and tcExtendIdEnv implements this behaviour.
872 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
879 -> InteractiveContext
881 -> IO (Maybe ([Id], LHsExpr Id))
882 -- The returned [Id] is the list of new Ids bound by
883 -- this statement. It can be used to extend the
884 -- InteractiveContext via extendInteractiveContext.
886 -- The returned TypecheckedHsExpr is of type IO [ () ],
887 -- a list of the bound values, coerced to ().
889 tcRnStmt hsc_env ictxt rdr_stmt
890 = initTcPrintErrors hsc_env iNTERACTIVE $
891 setInteractiveContext hsc_env ictxt $ do {
893 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
894 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
895 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
897 rnDump (ppr rn_stmt) ;
899 -- The real work is done here
900 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
901 zonked_expr <- zonkTopLExpr tc_expr ;
902 zonked_ids <- zonkTopBndrs bound_ids ;
904 -- None of the Ids should be of unboxed type, because we
905 -- cast them all to HValues in the end!
906 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
908 traceTc (text "tcs 1") ;
909 let { global_ids = map globaliseAndTidy zonked_ids } ;
911 {- ---------------------------------------------
912 At one stage I removed any shadowed bindings from the type_env;
913 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
914 However, with Template Haskell they aren't necessarily inaccessible. Consider this
916 Prelude> let f n = n * 2 :: Int
917 Prelude> fName <- runQ [| f |]
918 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
920 Prelude> let f n = n * 3 :: Int
921 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
922 In the last line we use 'fName', which resolves to the *first* 'f'
923 in scope. If we delete it from the type env, GHCi crashes because
924 it doesn't expect that.
926 Hence this code is commented out
928 -------------------------------------------------- -}
930 dumpOptTcRn Opt_D_dump_tc
931 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
932 text "Typechecked expr" <+> ppr zonked_expr]) ;
934 return (global_ids, zonked_expr)
937 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
938 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
940 globaliseAndTidy :: Id -> Id
941 globaliseAndTidy id -- Note [Interactively-bound Ids in GHCi]
942 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
944 tidy_type = tidyTopType (idType id)
947 Note [Interactively-bound Ids in GHCi]
948 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
949 The Ids bound by previous Stmts in Template Haskell are currently
951 b) with an Internal Name (not External)
954 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
955 compile an expression using these ids later, the byte code
956 generator will consider the occurrences to be free rather than
959 (b) They retain their Internal names becuase we don't have a suitable
960 Module to name them with. We could revisit this choice.
962 (c) Their types are tidied. This is important, because :info may ask
963 to look at them, and :info expects the things it looks up to have
967 --------------------------------------------------------------------------
968 Typechecking Stmts in GHCi
970 Here is the grand plan, implemented in tcUserStmt
972 What you type The IO [HValue] that hscStmt returns
973 ------------- ------------------------------------
974 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
977 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
980 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
981 [NB: result not printed] bindings: [it]
983 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
984 result showable) bindings: [it]
986 expr (of non-IO type,
987 result not showable) ==> error
991 ---------------------------
992 type PlanResult = ([Id], LHsExpr Id)
993 type Plan = TcM PlanResult
995 runPlans :: [Plan] -> TcM PlanResult
996 -- Try the plans in order. If one fails (by raising an exn), try the next.
997 -- If one succeeds, take it.
998 runPlans [] = panic "runPlans"
1000 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1002 --------------------
1003 mkPlan :: LStmt Name -> TcM PlanResult
1004 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1005 = do { uniq <- newUnique -- is treated very specially
1006 ; let fresh_it = itName uniq
1007 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1008 matches = [mkMatch [] expr emptyLocalBinds]
1009 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1010 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1011 (HsVar bindIOName) noSyntaxExpr
1012 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1013 (HsVar thenIOName) placeHolderType
1016 -- [it <- e; print it] but not if it::()
1018 -- [let it = e; print it]
1019 ; runPlans [ -- Plan A
1020 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1021 ; it_ty <- zonkTcType (idType it_id)
1022 ; when (isUnitTy it_ty) failM
1025 -- Plan B; a naked bind statment
1026 tcGhciStmts [bind_stmt],
1028 -- Plan C; check that the let-binding is typeable all by itself.
1029 -- If not, fail; if so, try to print it.
1030 -- The two-step process avoids getting two errors: one from
1031 -- the expression itself, and one from the 'print it' part
1032 -- This two-step story is very clunky, alas
1033 do { checkNoErrs (tcGhciStmts [let_stmt])
1034 --- checkNoErrs defeats the error recovery of let-bindings
1035 ; tcGhciStmts [let_stmt, print_it] }
1038 mkPlan stmt@(L loc (BindStmt {}))
1039 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1040 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1041 (HsVar thenIOName) placeHolderType
1043 ; print_bind_result <- doptM Opt_PrintBindResult
1044 ; let print_plan = do
1045 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1046 ; v_ty <- zonkTcType (idType v_id)
1047 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1051 -- [stmt; print v] but not if v::()
1053 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1054 [tcGhciStmts [stmt]])
1058 = tcGhciStmts [stmt]
1060 ---------------------------
1061 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1063 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1064 ret_id <- tcLookupId returnIOName ; -- return @ IO
1066 ret_ty = mkListTy unitTy ;
1067 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1068 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1070 names = map unLoc (collectLStmtsBinders stmts) ;
1072 -- mk_return builds the expression
1073 -- returnIO @ [()] [coerce () x, .., coerce () z]
1075 -- Despite the inconvenience of building the type applications etc,
1076 -- this *has* to be done in type-annotated post-typecheck form
1077 -- because we are going to return a list of *polymorphic* values
1078 -- coerced to type (). If we built a *source* stmt
1079 -- return [coerce x, ..., coerce z]
1080 -- then the type checker would instantiate x..z, and we wouldn't
1081 -- get their *polymorphic* values. (And we'd get ambiguity errs
1082 -- if they were overloaded, since they aren't applied to anything.)
1083 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1084 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1085 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1089 -- OK, we're ready to typecheck the stmts
1090 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1091 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1092 mapM tcLookupId names ;
1093 -- Look up the names right in the middle,
1094 -- where they will all be in scope
1096 -- Simplify the context
1097 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1098 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1099 -- checkNoErrs ensures that the plan fails if context redn fails
1101 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1102 return (ids, mkHsDictLet const_binds $
1103 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1108 tcRnExpr just finds the type of an expression
1112 -> InteractiveContext
1115 tcRnExpr hsc_env ictxt rdr_expr
1116 = initTcPrintErrors hsc_env iNTERACTIVE $
1117 setInteractiveContext hsc_env ictxt $ do {
1119 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1122 -- Now typecheck the expression;
1123 -- it might have a rank-2 type (e.g. :t runST)
1124 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1125 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1126 tcSimplifyInteractive lie_top ;
1128 let { all_expr_ty = mkForAllTys qtvs $
1129 mkFunTys (map (idType . instToId) dict_insts) $
1131 zonkTcType all_expr_ty
1134 smpl_doc = ptext SLIT("main expression")
1137 tcRnType just finds the kind of a type
1141 -> InteractiveContext
1144 tcRnType hsc_env ictxt rdr_type
1145 = initTcPrintErrors hsc_env iNTERACTIVE $
1146 setInteractiveContext hsc_env ictxt $ do {
1148 rn_type <- rnLHsType doc rdr_type ;
1151 -- Now kind-check the type
1152 (ty', kind) <- kcHsType rn_type ;
1156 doc = ptext SLIT("In GHCi input")
1162 %************************************************************************
1164 More GHCi stuff, to do with browsing and getting info
1166 %************************************************************************
1170 -- ASSUMES that the module is either in the HomePackageTable or is
1171 -- a package module with an interface on disk. If neither of these is
1172 -- true, then the result will be an error indicating the interface
1173 -- could not be found.
1174 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1175 getModuleExports hsc_env mod
1178 checkMods = ic_toplev_scope ic ++ ic_exports ic
1180 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1182 -- Get the export avail info and also load all orphan and family-instance
1183 -- modules. Finally, check that the family instances of all modules in the
1184 -- interactive context are consistent (these modules are in the second
1186 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1187 tcGetModuleExports mod directlyImpMods
1188 = do { let doc = ptext SLIT("context for compiling statements")
1189 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1191 -- Load any orphan-module and family instance-module
1192 -- interfaces, so their instances are visible.
1193 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1194 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1196 -- Check that the family instances of all directly loaded
1197 -- modules are consistent.
1198 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1200 ; ifaceExportNames (mi_exports iface)
1203 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1204 tcRnLookupRdrName hsc_env rdr_name
1205 = initTcPrintErrors hsc_env iNTERACTIVE $
1206 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1207 lookup_rdr_name rdr_name
1209 lookup_rdr_name rdr_name = do {
1210 -- If the identifier is a constructor (begins with an
1211 -- upper-case letter), then we need to consider both
1212 -- constructor and type class identifiers.
1213 let { rdr_names = dataTcOccs rdr_name } ;
1215 -- results :: [Either Messages Name]
1216 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1218 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1219 -- The successful lookups will be (Just name)
1220 let { (warns_s, good_names) = unzip [ (msgs, name)
1221 | (msgs, Just name) <- results] ;
1222 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1224 -- Fail if nothing good happened, else add warnings
1225 if null good_names then
1226 -- No lookup succeeded, so
1227 -- pick the first error message and report it
1228 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1229 -- while the other is "X is not in scope",
1230 -- we definitely want the former; but we might pick the latter
1231 do { addMessages (head errs_s) ; failM }
1232 else -- Add deprecation warnings
1233 mapM_ addMessages warns_s ;
1238 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1239 tcRnLookupName hsc_env name
1240 = initTcPrintErrors hsc_env iNTERACTIVE $
1241 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1242 tcRnLookupName' name
1244 -- To look up a name we have to look in the local environment (tcl_lcl)
1245 -- as well as the global environment, which is what tcLookup does.
1246 -- But we also want a TyThing, so we have to convert:
1248 tcRnLookupName' :: Name -> TcRn TyThing
1249 tcRnLookupName' name = do
1250 tcthing <- tcLookup name
1252 AGlobal thing -> return thing
1253 ATcId{tct_id=id} -> return (AnId id)
1254 _ -> panic "tcRnLookupName'"
1256 tcRnGetInfo :: HscEnv
1258 -> IO (Maybe (TyThing, Fixity, [Instance]))
1260 -- Used to implemnent :info in GHCi
1262 -- Look up a RdrName and return all the TyThings it might be
1263 -- A capitalised RdrName is given to us in the DataName namespace,
1264 -- but we want to treat it as *both* a data constructor
1265 -- *and* as a type or class constructor;
1266 -- hence the call to dataTcOccs, and we return up to two results
1267 tcRnGetInfo hsc_env name
1268 = initTcPrintErrors hsc_env iNTERACTIVE $
1269 let ictxt = hsc_IC hsc_env in
1270 setInteractiveContext hsc_env ictxt $ do
1272 -- Load the interface for all unqualified types and classes
1273 -- That way we will find all the instance declarations
1274 -- (Packages have not orphan modules, and we assume that
1275 -- in the home package all relevant modules are loaded.)
1276 loadUnqualIfaces ictxt
1278 thing <- tcRnLookupName' name
1279 fixity <- lookupFixityRn name
1280 ispecs <- lookupInsts thing
1281 return (thing, fixity, ispecs)
1283 lookupInsts :: TyThing -> TcM [Instance]
1284 lookupInsts (AClass cls)
1285 = do { inst_envs <- tcGetInstEnvs
1286 ; return (classInstances inst_envs cls) }
1288 lookupInsts (ATyCon tc)
1289 = do { eps <- getEps -- Load all instances for all classes that are
1290 -- in the type environment (which are all the ones
1291 -- we've seen in any interface file so far)
1292 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1294 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1295 , let dfun = instanceDFunId ispec
1298 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1299 tc_name = tyConName tc
1301 lookupInsts other = return []
1303 loadUnqualIfaces :: InteractiveContext -> TcM ()
1304 -- Load the home module for everything that is in scope unqualified
1305 -- This is so that we can accurately report the instances for
1307 loadUnqualIfaces ictxt
1309 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1311 unqual_mods = [ nameModule name
1312 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1313 let name = gre_name gre,
1314 not (isInternalName name),
1315 isTcOcc (nameOccName name), -- Types and classes only
1316 unQualOK gre ] -- In scope unqualified
1317 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1321 %************************************************************************
1325 %************************************************************************
1328 rnDump :: SDoc -> TcRn ()
1329 -- Dump, with a banner, if -ddump-rn
1330 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1332 tcDump :: TcGblEnv -> TcRn ()
1334 = do { dflags <- getDOpts ;
1336 -- Dump short output if -ddump-types or -ddump-tc
1337 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1338 (dumpTcRn short_dump) ;
1340 -- Dump bindings if -ddump-tc
1341 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1344 short_dump = pprTcGblEnv env
1345 full_dump = pprLHsBinds (tcg_binds env)
1346 -- NB: foreign x-d's have undefined's in their types;
1347 -- hence can't show the tc_fords
1350 = do { dflags <- getDOpts ;
1351 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1352 (dumpTcRn (pprModGuts mod_guts)) ;
1354 -- Dump bindings if -ddump-tc
1355 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1357 full_dump = pprCoreBindings (mg_binds mod_guts)
1359 -- It's unpleasant having both pprModGuts and pprModDetails here
1360 pprTcGblEnv :: TcGblEnv -> SDoc
1361 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1363 tcg_fam_insts = fam_insts,
1365 tcg_imports = imports })
1366 = vcat [ ppr_types insts type_env
1367 , ppr_tycons fam_insts type_env
1369 , ppr_fam_insts fam_insts
1370 , vcat (map ppr rules)
1371 , ppr_gen_tycons (typeEnvTyCons type_env)
1372 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1373 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1375 pprModGuts :: ModGuts -> SDoc
1376 pprModGuts (ModGuts { mg_types = type_env,
1378 = vcat [ ppr_types [] type_env,
1381 ppr_types :: [Instance] -> TypeEnv -> SDoc
1382 ppr_types insts type_env
1383 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1385 dfun_ids = map instanceDFunId insts
1386 ids = [id | id <- typeEnvIds type_env, want_sig id]
1387 want_sig id | opt_PprStyle_Debug = True
1388 | otherwise = isLocalId id &&
1389 isExternalName (idName id) &&
1390 not (id `elem` dfun_ids)
1391 -- isLocalId ignores data constructors, records selectors etc.
1392 -- The isExternalName ignores local dictionary and method bindings
1393 -- that the type checker has invented. Top-level user-defined things
1394 -- have External names.
1396 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1397 ppr_tycons fam_insts type_env
1398 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1400 fi_tycons = map famInstTyCon fam_insts
1401 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1402 want_tycon tycon | opt_PprStyle_Debug = True
1403 | otherwise = not (isImplicitTyCon tycon) &&
1404 isExternalName (tyConName tycon) &&
1405 not (tycon `elem` fi_tycons)
1407 ppr_insts :: [Instance] -> SDoc
1408 ppr_insts [] = empty
1409 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1411 ppr_fam_insts :: [FamInst] -> SDoc
1412 ppr_fam_insts [] = empty
1413 ppr_fam_insts fam_insts =
1414 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1416 ppr_sigs :: [Var] -> SDoc
1418 -- Print type signatures; sort by OccName
1419 = vcat (map ppr_sig (sortLe le_sig ids))
1421 le_sig id1 id2 = getOccName id1 <= getOccName id2
1422 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1424 ppr_tydecls :: [TyCon] -> SDoc
1426 -- Print type constructor info; sort by OccName
1427 = vcat (map ppr_tycon (sortLe le_sig tycons))
1429 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1431 | isCoercionTyCon tycon = ptext SLIT("coercion") <+> ppr tycon
1432 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1434 ppr_rules :: [CoreRule] -> SDoc
1435 ppr_rules [] = empty
1436 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1437 nest 4 (pprRules rs),
1440 ppr_gen_tycons [] = empty
1441 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1442 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]