2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
5 \section[TcModule]{Typechecking a whole module}
10 tcRnStmt, tcRnExpr, tcRnType,
22 #include "HsVersions.h"
26 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
90 import {- Kind parts of -} Type
99 import Control.Monad ( unless )
100 import Data.Maybe ( isJust )
101 import Foreign.Ptr ( Ptr )
107 %************************************************************************
109 Typecheck and rename a module
111 %************************************************************************
117 -> Bool -- True <=> save renamed syntax
118 -> Located (HsModule RdrName)
119 -> IO (Messages, Maybe TcGblEnv)
121 tcRnModule hsc_env hsc_src save_rn_syntax
122 (L loc (HsModule maybe_mod export_ies
123 import_decls local_decls mod_deprec _
124 module_info maybe_doc))
125 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
127 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
128 this_mod = case maybe_mod of
129 Nothing -> mAIN -- 'module M where' is omitted
130 Just (L _ mod) -> mkModule this_pkg mod } ;
133 initTc hsc_env hsc_src save_rn_syntax this_mod $
135 do { -- Deal with imports;
136 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
137 setGblEnv tcg_env $ do {
139 -- Load the hi-boot interface for this module, if any
140 -- We do this now so that the boot_names can be passed
141 -- to tcTyAndClassDecls, because the boot_names are
142 -- automatically considered to be loop breakers
144 -- Do this *after* tcRnImports, so that we know whether
145 -- a module that we import imports us; and hence whether to
146 -- look for a hi-boot file
147 boot_iface <- tcHiBootIface hsc_src this_mod ;
149 -- Rename and type check the declarations
150 traceRn (text "rn1a") ;
151 tcg_env <- if isHsBoot hsc_src then
152 tcRnHsBootDecls local_decls
154 tcRnSrcDecls boot_iface local_decls ;
155 setGblEnv tcg_env $ do {
157 -- Report the use of any deprecated things
158 -- We do this *before* processsing the export list so
159 -- that we don't bleat about re-exporting a deprecated
160 -- thing (especially via 'module Foo' export item)
161 -- That is, only uses in the *body* of the module are complained about
162 traceRn (text "rn3") ;
163 failIfErrsM ; -- finishDeprecations crashes sometimes
164 -- as a result of typechecker repairs (e.g. unboundNames)
165 tcg_env <- finishDeprecations (hsc_dflags hsc_env) mod_deprec tcg_env ;
167 -- Process the export list
168 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
169 traceRn (text "rn4") ;
171 -- Compare the hi-boot iface (if any) with the real thing
172 -- Must be done after processing the exports
173 tcg_env <- checkHiBootIface tcg_env boot_iface ;
175 -- Make the new type env available to stuff slurped from interface files
176 -- Must do this after checkHiBootIface, because the latter might add new
177 -- bindings for boot_dfuns, which may be mentioned in imported unfoldings
178 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
180 -- Rename the Haddock documentation
181 tcg_env <- rnHaddock module_info maybe_doc tcg_env ;
183 -- Report unused names
184 reportUnusedNames export_ies tcg_env ;
186 -- Dump output and return
193 %************************************************************************
197 %************************************************************************
200 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
201 tcRnImports hsc_env this_mod import_decls
202 = do { (rn_imports, rdr_env, imports) <- rnImports import_decls ;
204 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
205 ; dep_mods = imp_dep_mods imports
207 -- We want instance declarations from all home-package
208 -- modules below this one, including boot modules, except
209 -- ourselves. The 'except ourselves' is so that we don't
210 -- get the instances from this module's hs-boot file
211 ; want_instances :: ModuleName -> Bool
212 ; want_instances mod = mod `elemUFM` dep_mods
213 && mod /= moduleName this_mod
214 ; home_insts = hptInstances hsc_env want_instances
217 -- Record boot-file info in the EPS, so that it's
218 -- visible to loadHiBootInterface in tcRnSrcDecls,
219 -- and any other incrementally-performed imports
220 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
222 -- Update the gbl env
223 ; updGblEnv ( \ gbl ->
224 gbl { tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
225 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
226 tcg_rn_imports = fmap (const rn_imports) (tcg_rn_imports gbl),
227 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts
230 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
231 -- Fail if there are any errors so far
232 -- The error printing (if needed) takes advantage
233 -- of the tcg_env we have now set
234 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
237 -- Load any orphan-module and family instance-module
238 -- interfaces, so that their rules and instance decls will be
240 ; loadOrphanModules (imp_orphs imports) False
241 ; loadOrphanModules (imp_finsts imports) True
243 -- Check type-familily consistency
244 ; traceRn (text "rn1: checking family instance consistency")
245 ; let { dir_imp_mods = map (\ (mod, _, _) -> mod)
249 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
255 %************************************************************************
257 Type-checking external-core modules
259 %************************************************************************
262 tcRnExtCore :: HscEnv
264 -> IO (Messages, Maybe ModGuts)
265 -- Nothing => some error occurred
267 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
268 -- The decls are IfaceDecls; all names are original names
269 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
271 initTc hsc_env ExtCoreFile False this_mod $ do {
273 let { ldecls = map noLoc decls } ;
275 -- Deal with the type declarations; first bring their stuff
276 -- into scope, then rname them, then type check them
277 tcg_env <- importsFromLocalDecls (mkFakeGroup ldecls) ;
279 setGblEnv tcg_env $ do {
281 rn_decls <- rnTyClDecls ldecls ;
284 -- Dump trace of renaming part
285 rnDump (ppr rn_decls) ;
287 -- Typecheck them all together so that
288 -- any mutually recursive types are done right
289 tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails rn_decls) ;
290 -- Make the new type env available to stuff slurped from interface files
292 setGblEnv tcg_env $ do {
294 -- Now the core bindings
295 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
299 bndrs = bindersOfBinds core_binds ;
300 my_exports = map (Avail . idName) bndrs ;
301 -- ToDo: export the data types also?
303 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
305 mod_guts = ModGuts { mg_module = this_mod,
307 mg_usages = [], -- ToDo: compute usage
308 mg_dir_imps = [], -- ??
309 mg_deps = noDependencies, -- ??
310 mg_exports = my_exports,
311 mg_types = final_type_env,
312 mg_insts = tcg_insts tcg_env,
313 mg_fam_insts = tcg_fam_insts tcg_env,
314 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
316 mg_binds = core_binds,
319 mg_rdr_env = emptyGlobalRdrEnv,
320 mg_fix_env = emptyFixityEnv,
321 mg_deprecs = NoDeprecs,
322 mg_foreign = NoStubs,
323 mg_hpc_info = noHpcInfo,
324 mg_modBreaks = emptyModBreaks
327 tcCoreDump mod_guts ;
332 mkFakeGroup decls -- Rather clumsy; lots of unused fields
333 = emptyRdrGroup { hs_tyclds = decls }
337 %************************************************************************
339 Type-checking the top level of a module
341 %************************************************************************
344 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
345 -- Returns the variables free in the decls
346 -- Reason: solely to report unused imports and bindings
347 tcRnSrcDecls boot_iface decls
348 = do { -- Do all the declarations
349 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
351 -- Finish simplifying class constraints
353 -- tcSimplifyTop deals with constant or ambiguous InstIds.
354 -- How could there be ambiguous ones? They can only arise if a
355 -- top-level decl falls under the monomorphism restriction
356 -- and no subsequent decl instantiates its type.
358 -- We do this after checkMain, so that we use the type info
359 -- thaat checkMain adds
361 -- We do it with both global and local env in scope:
362 -- * the global env exposes the instances to tcSimplifyTop
363 -- * the local env exposes the local Ids to tcSimplifyTop,
364 -- so that we get better error messages (monomorphism restriction)
365 traceTc (text "Tc8") ;
366 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
368 -- Backsubstitution. This must be done last.
369 -- Even tcSimplifyTop may do some unification.
370 traceTc (text "Tc9") ;
371 let { (tcg_env, _) = tc_envs
372 ; TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
373 tcg_rules = rules, tcg_fords = fords } = tcg_env
374 ; all_binds = binds `unionBags` inst_binds } ;
376 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
378 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
379 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
382 tcg_fords = fords' } } ;
384 return (tcg_env' { tcg_binds = tcg_binds tcg_env' })
387 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
388 -- Loops around dealing with each top level inter-splice group
389 -- in turn, until it's dealt with the entire module
390 tc_rn_src_decls boot_details ds
391 = do { let { (first_group, group_tail) = findSplice ds } ;
392 -- If ds is [] we get ([], Nothing)
394 -- Deal with decls up to, but not including, the first splice
395 (tcg_env, rn_decls) <- checkNoErrs $ rnTopSrcDecls first_group ;
396 -- checkNoErrs: stop if renaming fails
398 (tcg_env, tcl_env) <- setGblEnv tcg_env $
399 tcTopSrcDecls boot_details rn_decls ;
401 -- If there is no splice, we're nearly done
402 setEnvs (tcg_env, tcl_env) $
404 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
405 return (tcg_env, tcl_env)
408 -- If there's a splice, we must carry on
409 Just (SpliceDecl splice_expr, rest_ds) -> do {
411 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
414 -- Rename the splice expression, and get its supporting decls
415 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
416 -- checkNoErrs: don't typecheck if renaming failed
417 rnDump (ppr rn_splice_expr) ;
419 -- Execute the splice
420 spliced_decls <- tcSpliceDecls rn_splice_expr ;
422 -- Glue them on the front of the remaining decls and loop
423 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
424 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
429 %************************************************************************
431 Compiling hs-boot source files, and
432 comparing the hi-boot interface with the real thing
434 %************************************************************************
437 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
438 tcRnHsBootDecls decls
439 = do { let { (first_group, group_tail) = findSplice decls }
442 Just stuff -> spliceInHsBootErr stuff
445 -- Rename the declarations
446 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
447 ; setGblEnv tcg_env $ do {
449 -- Todo: check no foreign decls, no rules, no default decls
451 -- Typecheck type/class decls
452 ; traceTc (text "Tc2")
453 ; let tycl_decls = hs_tyclds rn_group
454 ; tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails tycl_decls)
455 ; setGblEnv tcg_env $ do {
457 -- Typecheck instance decls
458 ; traceTc (text "Tc3")
459 ; (tcg_env, inst_infos, _deriv_binds)
460 <- tcInstDecls1 tycl_decls (hs_instds rn_group) (hs_derivds rn_group)
461 ; setGblEnv tcg_env $ do {
463 -- Typecheck value declarations
464 ; traceTc (text "Tc5")
465 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
468 -- No simplification or zonking to do
469 ; traceTc (text "Tc7a")
470 ; gbl_env <- getGblEnv
472 -- Make the final type-env
473 -- Include the dfun_ids so that their type sigs
474 -- are written into the interface file
475 ; let { type_env0 = tcg_type_env gbl_env
476 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
477 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
478 ; dfun_ids = map iDFunId inst_infos }
479 ; return (gbl_env { tcg_type_env = type_env2 })
482 spliceInHsBootErr (SpliceDecl (L loc _), _)
483 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
486 Once we've typechecked the body of the module, we want to compare what
487 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
490 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
491 -- Compare the hi-boot file for this module (if there is one)
492 -- with the type environment we've just come up with
493 -- In the common case where there is no hi-boot file, the list
494 -- of boot_names is empty.
496 -- The bindings we return give bindings for the dfuns defined in the
497 -- hs-boot file, such as $fbEqT = $fEqT
500 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
501 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
502 tcg_type_env = local_type_env, tcg_exports = local_exports })
503 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
504 md_types = boot_type_env, md_exports = boot_exports })
505 | isHsBoot hs_src -- Current module is already a hs-boot file!
509 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
512 -- Check the exports of the boot module, one by one
513 ; mapM_ check_export boot_exports
515 -- Check instance declarations
516 ; mb_dfun_prs <- mapM check_inst boot_insts
517 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds,
518 tcg_type_env = extendTypeEnvWithIds local_type_env boot_dfuns }
519 dfun_prs = catMaybes mb_dfun_prs
520 boot_dfuns = map fst dfun_prs
521 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
522 | (boot_dfun, dfun) <- dfun_prs ]
524 -- Check for no family instances
525 ; unless (null boot_fam_insts) $
526 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
527 "instances in boot files yet...")
528 -- FIXME: Why? The actual comparison is not hard, but what would
529 -- be the equivalent to the dfun bindings returned for class
530 -- instances? We can't easily equate tycons...
534 check_export boot_avail -- boot_avail is exported by the boot iface
535 | name `elem` dfun_names = return ()
536 | isWiredInName name = return () -- No checking for wired-in names. In particular,
537 -- 'error' is handled by a rather gross hack
538 -- (see comments in GHC.Err.hs-boot)
540 -- Check that the actual module exports the same thing
541 | not (null missing_names)
542 = addErrTc (missingBootThing (head missing_names) "exported by")
544 -- If the boot module does not *define* the thing, we are done
545 -- (it simply re-exports it, and names match, so nothing further to do)
546 | isNothing mb_boot_thing = return ()
548 -- Check that the actual module also defines the thing, and
549 -- then compare the definitions
550 | Just real_thing <- lookupTypeEnv local_type_env name
551 = do { let boot_decl = tyThingToIfaceDecl (fromJust mb_boot_thing)
552 real_decl = tyThingToIfaceDecl real_thing
553 ; checkTc (checkBootDecl boot_decl real_decl)
554 (bootMisMatch real_thing boot_decl real_decl) }
555 -- The easiest way to check compatibility is to convert to
556 -- iface syntax, where we already have good comparison functions
559 = addErrTc (missingBootThing name "defined in")
561 name = availName boot_avail
562 mb_boot_thing = lookupTypeEnv boot_type_env name
563 missing_names = case lookupNameEnv local_export_env name of
565 Just avail -> availNames boot_avail `minusList` availNames avail
567 dfun_names = map getName boot_insts
569 local_export_env :: NameEnv AvailInfo
570 local_export_env = availsToNameEnv local_exports
572 check_inst :: Instance -> TcM (Maybe (Id, Id))
573 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
575 = case [dfun | inst <- local_insts,
576 let dfun = instanceDFunId inst,
577 idType dfun `tcEqType` boot_inst_ty ] of
578 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
579 (dfun:_) -> return (Just (local_boot_dfun, dfun))
581 boot_dfun = instanceDFunId boot_inst
582 boot_inst_ty = idType boot_dfun
583 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
587 missingBootThing thing what
588 = ppr thing <+> ptext SLIT("is exported by the hs-boot file, but not")
589 <+> text what <+> ptext SLIT("the module")
591 bootMisMatch thing boot_decl real_decl
592 = vcat [ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file"),
593 ptext SLIT("Main module:") <+> ppr real_decl,
594 ptext SLIT("Boot file: ") <+> ppr boot_decl]
598 2 (ptext SLIT("is defined in the hs-boot file, but not in the module itself"))
602 %************************************************************************
604 Type-checking the top level of a module
606 %************************************************************************
608 tcRnGroup takes a bunch of top-level source-code declarations, and
610 * gets supporting declarations from interface files
613 * and augments the TcGblEnv with the results
615 In Template Haskell it may be called repeatedly for each group of
616 declarations. It expects there to be an incoming TcGblEnv in the
617 monad; it augments it and returns the new TcGblEnv.
620 ------------------------------------------------
621 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
623 = do { -- Bring top level binders into scope
624 tcg_env <- importsFromLocalDecls group ;
625 setGblEnv tcg_env $ do {
627 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
629 -- Rename the source decls
630 (tcg_env, rn_decls) <- rnSrcDecls group ;
633 -- save the renamed syntax, if we want it
635 | Just grp <- tcg_rn_decls tcg_env
636 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
640 -- Dump trace of renaming part
641 rnDump (ppr rn_decls) ;
643 return (tcg_env', rn_decls)
646 ------------------------------------------------
647 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
648 tcTopSrcDecls boot_details
649 (HsGroup { hs_tyclds = tycl_decls,
650 hs_instds = inst_decls,
651 hs_derivds = deriv_decls,
652 hs_fords = foreign_decls,
653 hs_defds = default_decls,
654 hs_ruleds = rule_decls,
655 hs_valds = val_binds })
656 = do { -- Type-check the type and class decls, and all imported decls
657 -- The latter come in via tycl_decls
658 traceTc (text "Tc2") ;
660 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
661 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
662 -- an error we'd better stop now, to avoid a cascade
664 -- Make these type and class decls available to stuff slurped from interface files
665 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
668 setGblEnv tcg_env $ do {
669 -- Source-language instances, including derivings,
670 -- and import the supporting declarations
671 traceTc (text "Tc3") ;
672 (tcg_env, inst_infos, deriv_binds)
673 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
674 setGblEnv tcg_env $ do {
676 -- Foreign import declarations next. No zonking necessary
677 -- here; we can tuck them straight into the global environment.
678 traceTc (text "Tc4") ;
679 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
680 tcExtendGlobalValEnv fi_ids $ do {
682 -- Default declarations
683 traceTc (text "Tc4a") ;
684 default_tys <- tcDefaults default_decls ;
685 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
687 -- Value declarations next
688 -- We also typecheck any extra binds that came out
689 -- of the "deriving" process (deriv_binds)
690 traceTc (text "Tc5") ;
691 (tc_val_binds, tcl_env) <- tcTopBinds (val_binds `plusHsValBinds` deriv_binds) ;
692 setLclTypeEnv tcl_env $ do {
694 -- Second pass over class and instance declarations,
695 traceTc (text "Tc6") ;
696 (inst_binds, tcl_env) <- tcInstDecls2 tycl_decls inst_infos ;
697 showLIE (text "after instDecls2") ;
700 -- They need to be zonked, so we return them
701 traceTc (text "Tc7") ;
702 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
705 rules <- tcRules rule_decls ;
708 traceTc (text "Tc7a") ;
709 tcg_env <- getGblEnv ;
710 let { all_binds = tc_val_binds `unionBags`
711 inst_binds `unionBags`
714 -- Extend the GblEnv with the (as yet un-zonked)
715 -- bindings, rules, foreign decls
716 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
717 tcg_rules = tcg_rules tcg_env ++ rules,
718 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
719 return (tcg_env', tcl_env)
724 %************************************************************************
728 %************************************************************************
731 checkMain :: TcM TcGblEnv
732 -- If we are in module Main, check that 'main' is defined.
734 = do { tcg_env <- getGblEnv ;
736 let { main_mod = mainModIs dflags ;
737 main_fn = case mainFunIs dflags of {
738 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn)) ;
739 Nothing -> main_RDR_Unqual } } ;
741 check_main dflags tcg_env main_mod main_fn
745 check_main dflags tcg_env main_mod main_fn
747 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
751 = addErrCtxt mainCtxt $
752 do { mb_main <- lookupSrcOcc_maybe main_fn
753 -- Check that 'main' is in scope
754 -- It might be imported from another module!
756 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
760 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
761 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
762 -- :Main.main :: IO () = runMainIO main
764 ; (main_expr, ty) <- setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
767 -- See Note [Root-main Id]
768 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
769 (mkVarOccFS FSLIT("main"))
770 (getSrcLoc main_name)
771 ; root_main_id = Id.mkExportedLocalId root_main_name ty
772 ; main_bind = noLoc (VarBind root_main_id main_expr) }
774 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
776 tcg_dus = tcg_dus tcg_env
777 `plusDU` usesOnly (unitFV main_name)
778 -- Record the use of 'main', so that we don't
779 -- complain about it being defined but not used
783 mod = tcg_mod tcg_env
785 complain_no_main | ghcLink dflags == LinkInMemory = return ()
786 | otherwise = failWithTc noMainMsg
787 -- In interactive mode, don't worry about the absence of 'main'
788 -- In other modes, fail altogether, so that we don't go on
789 -- and complain a second time when processing the export list.
791 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
792 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
793 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
798 The function that the RTS invokes is always :Main.main, which we call
799 root_main_id. (Because GHC allows the user to have a module not
800 called Main as the main module, we can't rely on the main function
801 being called "Main.main". That's why root_main_id has a fixed module
804 This is unusual: it's a LocalId whose Name has a Module from another
805 module. Tiresomely, we must filter it out again in MkIface, les we
806 get two defns for 'main' in the interface file!
809 %*********************************************************
813 %*********************************************************
817 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
818 setInteractiveContext hsc_env icxt thing_inside
820 -- Initialise the tcg_inst_env with instances
821 -- from all home modules. This mimics the more selective
822 -- call to hptInstances in tcRnModule
823 dfuns = hptInstances hsc_env (\mod -> True)
825 updGblEnv (\env -> env {
826 tcg_rdr_env = ic_rn_gbl_env icxt,
827 tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
830 tcExtendIdEnv (typeEnvIds (ic_type_env icxt)) $
831 -- tcExtendIdEnv does lots:
832 -- - it extends the local type env (tcl_env) with the given Ids,
833 -- - it extends the local rdr env (tcl_rdr) with the Names from
835 -- - it adds the free tyvars of the Ids to the tcl_tyvars
838 -- We should have no Ids with the same name in the
839 -- ic_type_env, otherwise we'll end up with shadowing in the
840 -- tcl_rdr, and it's random which one will be in scope.
842 do { traceTc (text "setIC" <+> ppr (ic_type_env icxt))
849 -> InteractiveContext
851 -> IO (Maybe (InteractiveContext, [Name], LHsExpr Id))
852 -- The returned [Name] is the same as the input except for
853 -- ExprStmt, in which case the returned [Name] is [itName]
855 -- The returned TypecheckedHsExpr is of type IO [ () ],
856 -- a list of the bound values, coerced to ().
858 tcRnStmt hsc_env ictxt rdr_stmt
859 = initTcPrintErrors hsc_env iNTERACTIVE $
860 setInteractiveContext hsc_env ictxt $ do {
862 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
863 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
864 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
867 -- The real work is done here
868 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
869 zonked_expr <- zonkTopLExpr tc_expr ;
870 zonked_ids <- zonkTopBndrs bound_ids ;
872 -- None of the Ids should be of unboxed type, because we
873 -- cast them all to HValues in the end!
874 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
876 traceTc (text "tcs 1") ;
877 let { -- (a) Make all the bound ids "global" ids, now that
878 -- they're notionally top-level bindings. This is
879 -- important: otherwise when we come to compile an expression
880 -- using these ids later, the byte code generator will consider
881 -- the occurrences to be free rather than global.
883 -- (b) Tidy their types; this is important, because :info may
884 -- ask to look at them, and :info expects the things it looks
885 -- up to have tidy types
886 global_ids = map globaliseAndTidy zonked_ids ;
888 bound_names = map idName global_ids ;
890 {- ---------------------------------------------
891 At one stage I removed any shadowed bindings from the type_env;
892 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
893 However, with Template Haskell they aren't necessarily inaccessible. Consider this
895 Prelude> let f n = n * 2 :: Int
896 Prelude> fName <- runQ [| f |]
897 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
899 Prelude> let f n = n * 3 :: Int
900 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
901 In the last line we use 'fName', which resolves to the *first* 'f'
902 in scope. If we delete it from the type env, GHCi crashes because
903 it doesn't expect that.
905 Hence this code is commented out
907 -------------------------------------------------- -}
909 new_ic = extendInteractiveContext ictxt global_ids emptyVarSet ;
912 dumpOptTcRn Opt_D_dump_tc
913 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
914 text "Typechecked expr" <+> ppr zonked_expr]) ;
916 returnM (new_ic, bound_names, zonked_expr)
919 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
920 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
922 globaliseAndTidy :: Id -> Id
924 -- Give the Id a Global Name, and tidy its type
925 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
927 tidy_type = tidyTopType (idType id)
930 Here is the grand plan, implemented in tcUserStmt
932 What you type The IO [HValue] that hscStmt returns
933 ------------- ------------------------------------
934 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
937 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
940 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
941 [NB: result not printed] bindings: [it]
943 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
944 result showable) bindings: [it]
946 expr (of non-IO type,
947 result not showable) ==> error
951 ---------------------------
952 type PlanResult = ([Id], LHsExpr Id)
953 type Plan = TcM PlanResult
955 runPlans :: [Plan] -> TcM PlanResult
956 -- Try the plans in order. If one fails (by raising an exn), try the next.
957 -- If one succeeds, take it.
958 runPlans [] = panic "runPlans"
960 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
963 mkPlan :: LStmt Name -> TcM PlanResult
964 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
965 = do { uniq <- newUnique -- is treated very specially
966 ; let fresh_it = itName uniq
967 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
968 matches = [mkMatch [] expr emptyLocalBinds]
969 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
970 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
971 (HsVar bindIOName) noSyntaxExpr
972 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
973 (HsVar thenIOName) placeHolderType
976 -- [it <- e; print it] but not if it::()
978 -- [let it = e; print it]
979 ; runPlans [ -- Plan A
980 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
981 ; it_ty <- zonkTcType (idType it_id)
982 ; ifM (isUnitTy it_ty) failM
985 -- Plan B; a naked bind statment
986 tcGhciStmts [bind_stmt],
988 -- Plan C; check that the let-binding is typeable all by itself.
989 -- If not, fail; if so, try to print it.
990 -- The two-step process avoids getting two errors: one from
991 -- the expression itself, and one from the 'print it' part
992 -- This two-step story is very clunky, alas
993 do { checkNoErrs (tcGhciStmts [let_stmt])
994 --- checkNoErrs defeats the error recovery of let-bindings
995 ; tcGhciStmts [let_stmt, print_it] }
998 mkPlan stmt@(L loc (BindStmt {}))
999 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1000 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1001 (HsVar thenIOName) placeHolderType
1003 ; print_bind_result <- doptM Opt_PrintBindResult
1004 ; let print_plan = do
1005 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1006 ; v_ty <- zonkTcType (idType v_id)
1007 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
1011 -- [stmt; print v] but not if v::()
1013 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1014 [tcGhciStmts [stmt]])
1018 = tcGhciStmts [stmt]
1020 ---------------------------
1021 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1023 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1024 ret_id <- tcLookupId returnIOName ; -- return @ IO
1026 io_ty = mkTyConApp ioTyCon [] ;
1027 ret_ty = mkListTy unitTy ;
1028 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1029 tc_io_stmts stmts = tcStmts DoExpr (tcDoStmt io_ty) stmts
1030 (emptyRefinement, io_ret_ty) ;
1032 names = map unLoc (collectLStmtsBinders stmts) ;
1034 -- mk_return builds the expression
1035 -- returnIO @ [()] [coerce () x, .., coerce () z]
1037 -- Despite the inconvenience of building the type applications etc,
1038 -- this *has* to be done in type-annotated post-typecheck form
1039 -- because we are going to return a list of *polymorphic* values
1040 -- coerced to type (). If we built a *source* stmt
1041 -- return [coerce x, ..., coerce z]
1042 -- then the type checker would instantiate x..z, and we wouldn't
1043 -- get their *polymorphic* values. (And we'd get ambiguity errs
1044 -- if they were overloaded, since they aren't applied to anything.)
1045 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1046 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1047 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1051 -- OK, we're ready to typecheck the stmts
1052 traceTc (text "tcs 2") ;
1053 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1054 mappM tcLookupId names ;
1055 -- Look up the names right in the middle,
1056 -- where they will all be in scope
1058 -- Simplify the context
1059 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1060 -- checkNoErrs ensures that the plan fails if context redn fails
1062 return (ids, mkHsDictLet const_binds $
1063 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1068 tcRnExpr just finds the type of an expression
1072 -> InteractiveContext
1075 tcRnExpr hsc_env ictxt rdr_expr
1076 = initTcPrintErrors hsc_env iNTERACTIVE $
1077 setInteractiveContext hsc_env ictxt $ do {
1079 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1082 -- Now typecheck the expression;
1083 -- it might have a rank-2 type (e.g. :t runST)
1084 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1085 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1086 tcSimplifyInteractive lie_top ;
1088 let { all_expr_ty = mkForAllTys qtvs $
1089 mkFunTys (map (idType . instToId) dict_insts) $
1091 zonkTcType all_expr_ty
1094 smpl_doc = ptext SLIT("main expression")
1097 tcRnType just finds the kind of a type
1101 -> InteractiveContext
1104 tcRnType hsc_env ictxt rdr_type
1105 = initTcPrintErrors hsc_env iNTERACTIVE $
1106 setInteractiveContext hsc_env ictxt $ do {
1108 rn_type <- rnLHsType doc rdr_type ;
1111 -- Now kind-check the type
1112 (ty', kind) <- kcHsType rn_type ;
1116 doc = ptext SLIT("In GHCi input")
1122 %************************************************************************
1124 More GHCi stuff, to do with browsing and getting info
1126 %************************************************************************
1130 -- ASSUMES that the module is either in the HomePackageTable or is
1131 -- a package module with an interface on disk. If neither of these is
1132 -- true, then the result will be an error indicating the interface
1133 -- could not be found.
1134 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1135 getModuleExports hsc_env mod
1138 checkMods = ic_toplev_scope ic ++ ic_exports ic
1140 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1142 -- Get the export avail info and also load all orphan and family-instance
1143 -- modules. Finally, check that the family instances of all modules in the
1144 -- interactive context are consistent (these modules are in the second
1146 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1147 tcGetModuleExports mod directlyImpMods
1148 = do { let doc = ptext SLIT("context for compiling statements")
1149 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1151 -- Load any orphan-module and family instance-module
1152 -- interfaces, so their instances are visible.
1153 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1154 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1156 -- Check that the family instances of all directly loaded
1157 -- modules are consistent.
1158 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1160 ; ifaceExportNames (mi_exports iface)
1163 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1164 tcRnLookupRdrName hsc_env rdr_name
1165 = initTcPrintErrors hsc_env iNTERACTIVE $
1166 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1167 lookup_rdr_name rdr_name
1169 lookup_rdr_name rdr_name = do {
1170 -- If the identifier is a constructor (begins with an
1171 -- upper-case letter), then we need to consider both
1172 -- constructor and type class identifiers.
1173 let { rdr_names = dataTcOccs rdr_name } ;
1175 -- results :: [Either Messages Name]
1176 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1178 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1179 -- The successful lookups will be (Just name)
1180 let { (warns_s, good_names) = unzip [ (msgs, name)
1181 | (msgs, Just name) <- results] ;
1182 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1184 -- Fail if nothing good happened, else add warnings
1185 if null good_names then
1186 -- No lookup succeeded, so
1187 -- pick the first error message and report it
1188 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1189 -- while the other is "X is not in scope",
1190 -- we definitely want the former; but we might pick the latter
1191 do { addMessages (head errs_s) ; failM }
1192 else -- Add deprecation warnings
1193 mapM_ addMessages warns_s ;
1198 tcRnRecoverDataCon :: HscEnv -> Ptr () -> IO (Maybe DataCon)
1199 tcRnRecoverDataCon hsc_env ptr
1200 = initTcPrintErrors hsc_env iNTERACTIVE $
1201 setInteractiveContext hsc_env (hsc_IC hsc_env) $ do
1202 name <- dataConInfoPtrToName ptr
1203 tcLookupDataCon name
1205 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1206 tcRnLookupName hsc_env name
1207 = initTcPrintErrors hsc_env iNTERACTIVE $
1208 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1209 tcRnLookupName' name
1211 -- To look up a name we have to look in the local environment (tcl_lcl)
1212 -- as well as the global environment, which is what tcLookup does.
1213 -- But we also want a TyThing, so we have to convert:
1215 tcRnLookupName' :: Name -> TcRn TyThing
1216 tcRnLookupName' name = do
1217 tcthing <- tcLookup name
1219 AGlobal thing -> return thing
1220 ATcId{tct_id=id} -> return (AnId id)
1221 _ -> panic "tcRnLookupName'"
1223 tcRnGetInfo :: HscEnv
1225 -> IO (Maybe (TyThing, Fixity, [Instance]))
1227 -- Used to implemnent :info in GHCi
1229 -- Look up a RdrName and return all the TyThings it might be
1230 -- A capitalised RdrName is given to us in the DataName namespace,
1231 -- but we want to treat it as *both* a data constructor
1232 -- *and* as a type or class constructor;
1233 -- hence the call to dataTcOccs, and we return up to two results
1234 tcRnGetInfo hsc_env name
1235 = initTcPrintErrors hsc_env iNTERACTIVE $
1236 let ictxt = hsc_IC hsc_env in
1237 setInteractiveContext hsc_env ictxt $ do
1239 -- Load the interface for all unqualified types and classes
1240 -- That way we will find all the instance declarations
1241 -- (Packages have not orphan modules, and we assume that
1242 -- in the home package all relevant modules are loaded.)
1243 loadUnqualIfaces ictxt
1245 thing <- tcRnLookupName' name
1246 fixity <- lookupFixityRn name
1247 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1248 return (thing, fixity, ispecs)
1250 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1251 -- Filter the instances by the ones whose tycons (or clases resp)
1252 -- are in scope unqualified. Otherwise we list a whole lot too many!
1253 lookupInsts print_unqual (AClass cls)
1254 = do { inst_envs <- tcGetInstEnvs
1256 | ispec <- classInstances inst_envs cls
1257 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1259 lookupInsts print_unqual (ATyCon tc)
1260 = do { eps <- getEps -- Load all instances for all classes that are
1261 -- in the type environment (which are all the ones
1262 -- we've seen in any interface file so far)
1263 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1265 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1266 , let dfun = instanceDFunId ispec
1268 , plausibleDFun print_unqual dfun ] }
1270 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1271 tc_name = tyConName tc
1273 lookupInsts print_unqual other = return []
1275 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1276 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1278 ok name | isBuiltInSyntax name = True
1279 | isExternalName name =
1280 isNothing $ fst print_unqual (nameModule name)
1284 loadUnqualIfaces :: InteractiveContext -> TcM ()
1285 -- Load the home module for everything that is in scope unqualified
1286 -- This is so that we can accurately report the instances for
1288 loadUnqualIfaces ictxt
1290 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1292 unqual_mods = [ nameModule name
1293 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1294 let name = gre_name gre,
1295 not (isInternalName name),
1296 isTcOcc (nameOccName name), -- Types and classes only
1297 unQualOK gre ] -- In scope unqualified
1298 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1302 %************************************************************************
1306 %************************************************************************
1309 rnDump :: SDoc -> TcRn ()
1310 -- Dump, with a banner, if -ddump-rn
1311 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1313 tcDump :: TcGblEnv -> TcRn ()
1315 = do { dflags <- getDOpts ;
1317 -- Dump short output if -ddump-types or -ddump-tc
1318 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1319 (dumpTcRn short_dump) ;
1321 -- Dump bindings if -ddump-tc
1322 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1325 short_dump = pprTcGblEnv env
1326 full_dump = pprLHsBinds (tcg_binds env)
1327 -- NB: foreign x-d's have undefined's in their types;
1328 -- hence can't show the tc_fords
1331 = do { dflags <- getDOpts ;
1332 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1333 (dumpTcRn (pprModGuts mod_guts)) ;
1335 -- Dump bindings if -ddump-tc
1336 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1338 full_dump = pprCoreBindings (mg_binds mod_guts)
1340 -- It's unpleasant having both pprModGuts and pprModDetails here
1341 pprTcGblEnv :: TcGblEnv -> SDoc
1342 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1344 tcg_fam_insts = fam_insts,
1346 tcg_imports = imports })
1347 = vcat [ ppr_types insts type_env
1348 , ppr_tycons fam_insts type_env
1350 , ppr_fam_insts fam_insts
1351 , vcat (map ppr rules)
1352 , ppr_gen_tycons (typeEnvTyCons type_env)
1353 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1354 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1356 pprModGuts :: ModGuts -> SDoc
1357 pprModGuts (ModGuts { mg_types = type_env,
1359 = vcat [ ppr_types [] type_env,
1362 ppr_types :: [Instance] -> TypeEnv -> SDoc
1363 ppr_types insts type_env
1364 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1366 dfun_ids = map instanceDFunId insts
1367 ids = [id | id <- typeEnvIds type_env, want_sig id]
1368 want_sig id | opt_PprStyle_Debug = True
1369 | otherwise = isLocalId id &&
1370 isExternalName (idName id) &&
1371 not (id `elem` dfun_ids)
1372 -- isLocalId ignores data constructors, records selectors etc.
1373 -- The isExternalName ignores local dictionary and method bindings
1374 -- that the type checker has invented. Top-level user-defined things
1375 -- have External names.
1377 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1378 ppr_tycons fam_insts type_env
1379 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1381 fi_tycons = map famInstTyCon fam_insts
1382 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1383 want_tycon tycon | opt_PprStyle_Debug = True
1384 | otherwise = not (isImplicitTyCon tycon) &&
1385 isExternalName (tyConName tycon) &&
1386 not (tycon `elem` fi_tycons)
1388 ppr_insts :: [Instance] -> SDoc
1389 ppr_insts [] = empty
1390 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1392 ppr_fam_insts :: [FamInst] -> SDoc
1393 ppr_fam_insts [] = empty
1394 ppr_fam_insts fam_insts =
1395 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1397 ppr_sigs :: [Var] -> SDoc
1399 -- Print type signatures; sort by OccName
1400 = vcat (map ppr_sig (sortLe le_sig ids))
1402 le_sig id1 id2 = getOccName id1 <= getOccName id2
1403 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1405 ppr_tydecls :: [TyCon] -> SDoc
1407 -- Print type constructor info; sort by OccName
1408 = vcat (map ppr_tycon (sortLe le_sig tycons))
1410 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1412 | isCoercionTyCon tycon = ptext SLIT("coercion") <+> ppr tycon
1413 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1415 ppr_rules :: [CoreRule] -> SDoc
1416 ppr_rules [] = empty
1417 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1418 nest 4 (pprRules rs),
1421 ppr_gen_tycons [] = empty
1422 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1423 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]