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 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
174 traceRn (text "rn4") ;
176 -- Compare the hi-boot iface (if any) with the real thing
177 -- Must be done after processing the exports
178 tcg_env <- checkHiBootIface tcg_env boot_iface ;
180 -- Make the new type env available to stuff slurped from interface files
181 -- Must do this after checkHiBootIface, because the latter might add new
182 -- bindings for boot_dfuns, which may be mentioned in imported unfoldings
183 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
185 -- Rename the Haddock documentation
186 tcg_env <- rnHaddock module_info maybe_doc tcg_env ;
188 -- Report unused names
189 reportUnusedNames export_ies tcg_env ;
191 -- Dump output and return
198 %************************************************************************
202 %************************************************************************
205 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
206 tcRnImports hsc_env this_mod import_decls
207 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
209 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
210 ; dep_mods = imp_dep_mods imports
212 -- We want instance declarations from all home-package
213 -- modules below this one, including boot modules, except
214 -- ourselves. The 'except ourselves' is so that we don't
215 -- get the instances from this module's hs-boot file
216 ; want_instances :: ModuleName -> Bool
217 ; want_instances mod = mod `elemUFM` dep_mods
218 && mod /= moduleName this_mod
219 ; (home_insts, home_fam_insts) = hptInstances hsc_env
223 -- Record boot-file info in the EPS, so that it's
224 -- visible to loadHiBootInterface in tcRnSrcDecls,
225 -- and any other incrementally-performed imports
226 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
228 -- Update the gbl env
229 ; updGblEnv ( \ gbl ->
231 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
232 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
233 tcg_rn_imports = fmap (const rn_imports) (tcg_rn_imports gbl),
234 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
235 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
240 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
241 -- Fail if there are any errors so far
242 -- The error printing (if needed) takes advantage
243 -- of the tcg_env we have now set
244 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
247 -- Load any orphan-module and family instance-module
248 -- interfaces, so that their rules and instance decls will be
250 ; loadOrphanModules (imp_orphs imports) False
251 ; loadOrphanModules (imp_finsts imports) True
253 -- Check type-familily consistency
254 ; traceRn (text "rn1: checking family instance consistency")
255 ; let { dir_imp_mods = map (\ (mod, _) -> mod)
259 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
265 %************************************************************************
267 Type-checking external-core modules
269 %************************************************************************
272 tcRnExtCore :: HscEnv
274 -> IO (Messages, Maybe ModGuts)
275 -- Nothing => some error occurred
277 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
278 -- The decls are IfaceDecls; all names are original names
279 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
281 initTc hsc_env ExtCoreFile False this_mod $ do {
283 let { ldecls = map noLoc decls } ;
285 -- Deal with the type declarations; first bring their stuff
286 -- into scope, then rname them, then type check them
287 tcg_env <- importsFromLocalDecls (mkFakeGroup ldecls) ;
289 setGblEnv tcg_env $ do {
291 rn_decls <- rnTyClDecls ldecls ;
294 -- Dump trace of renaming part
295 rnDump (ppr rn_decls) ;
297 -- Typecheck them all together so that
298 -- any mutually recursive types are done right
299 tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails rn_decls) ;
300 -- Make the new type env available to stuff slurped from interface files
302 setGblEnv tcg_env $ do {
304 -- Now the core bindings
305 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
309 bndrs = bindersOfBinds core_binds ;
310 my_exports = map (Avail . idName) bndrs ;
311 -- ToDo: export the data types also?
313 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
315 mod_guts = ModGuts { mg_module = this_mod,
317 mg_usages = [], -- ToDo: compute usage
318 mg_dir_imps = [], -- ??
319 mg_deps = noDependencies, -- ??
320 mg_exports = my_exports,
321 mg_types = final_type_env,
322 mg_insts = tcg_insts tcg_env,
323 mg_fam_insts = tcg_fam_insts tcg_env,
324 mg_inst_env = tcg_inst_env tcg_env,
325 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
327 mg_binds = core_binds,
330 mg_rdr_env = emptyGlobalRdrEnv,
331 mg_fix_env = emptyFixityEnv,
332 mg_deprecs = NoDeprecs,
333 mg_foreign = NoStubs,
334 mg_hpc_info = emptyHpcInfo False,
335 mg_modBreaks = emptyModBreaks,
336 mg_vect_info = noVectInfo
339 tcCoreDump mod_guts ;
344 mkFakeGroup decls -- Rather clumsy; lots of unused fields
345 = emptyRdrGroup { hs_tyclds = decls }
349 %************************************************************************
351 Type-checking the top level of a module
353 %************************************************************************
356 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
357 -- Returns the variables free in the decls
358 -- Reason: solely to report unused imports and bindings
359 tcRnSrcDecls boot_iface decls
360 = do { -- Do all the declarations
361 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
363 -- Finish simplifying class constraints
365 -- tcSimplifyTop deals with constant or ambiguous InstIds.
366 -- How could there be ambiguous ones? They can only arise if a
367 -- top-level decl falls under the monomorphism restriction
368 -- and no subsequent decl instantiates its type.
370 -- We do this after checkMain, so that we use the type info
371 -- thaat checkMain adds
373 -- We do it with both global and local env in scope:
374 -- * the global env exposes the instances to tcSimplifyTop
375 -- * the local env exposes the local Ids to tcSimplifyTop,
376 -- so that we get better error messages (monomorphism restriction)
377 traceTc (text "Tc8") ;
378 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
380 -- Backsubstitution. This must be done last.
381 -- Even tcSimplifyTop may do some unification.
382 traceTc (text "Tc9") ;
383 let { (tcg_env, _) = tc_envs
384 ; TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
385 tcg_rules = rules, tcg_fords = fords } = tcg_env
386 ; all_binds = binds `unionBags` inst_binds } ;
388 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
390 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
391 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
394 tcg_fords = fords' } } ;
396 return (tcg_env' { tcg_binds = tcg_binds tcg_env' })
399 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
400 -- Loops around dealing with each top level inter-splice group
401 -- in turn, until it's dealt with the entire module
402 tc_rn_src_decls boot_details ds
403 = do { let { (first_group, group_tail) = findSplice ds } ;
404 -- If ds is [] we get ([], Nothing)
406 -- Deal with decls up to, but not including, the first splice
407 (tcg_env, rn_decls) <- checkNoErrs $ rnTopSrcDecls first_group ;
408 -- checkNoErrs: stop if renaming fails
410 (tcg_env, tcl_env) <- setGblEnv tcg_env $
411 tcTopSrcDecls boot_details rn_decls ;
413 -- If there is no splice, we're nearly done
414 setEnvs (tcg_env, tcl_env) $
416 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
417 return (tcg_env, tcl_env)
420 -- If there's a splice, we must carry on
421 Just (SpliceDecl splice_expr, rest_ds) -> do {
423 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
426 -- Rename the splice expression, and get its supporting decls
427 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
428 -- checkNoErrs: don't typecheck if renaming failed
429 rnDump (ppr rn_splice_expr) ;
431 -- Execute the splice
432 spliced_decls <- tcSpliceDecls rn_splice_expr ;
434 -- Glue them on the front of the remaining decls and loop
435 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
436 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
441 %************************************************************************
443 Compiling hs-boot source files, and
444 comparing the hi-boot interface with the real thing
446 %************************************************************************
449 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
450 tcRnHsBootDecls decls
451 = do { let { (first_group, group_tail) = findSplice decls }
454 Just stuff -> spliceInHsBootErr stuff
457 -- Rename the declarations
458 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
459 ; setGblEnv tcg_env $ do {
461 -- Todo: check no foreign decls, no rules, no default decls
463 -- Typecheck type/class decls
464 ; traceTc (text "Tc2")
465 ; let tycl_decls = hs_tyclds rn_group
466 ; tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails tycl_decls)
467 ; setGblEnv tcg_env $ do {
469 -- Typecheck instance decls
470 ; traceTc (text "Tc3")
471 ; (tcg_env, inst_infos, _deriv_binds)
472 <- tcInstDecls1 tycl_decls (hs_instds rn_group) (hs_derivds rn_group)
473 ; setGblEnv tcg_env $ do {
475 -- Typecheck value declarations
476 ; traceTc (text "Tc5")
477 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
480 -- No simplification or zonking to do
481 ; traceTc (text "Tc7a")
482 ; gbl_env <- getGblEnv
484 -- Make the final type-env
485 -- Include the dfun_ids so that their type sigs
486 -- are written into the interface file
487 ; let { type_env0 = tcg_type_env gbl_env
488 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
489 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
490 ; dfun_ids = map iDFunId inst_infos }
491 ; return (gbl_env { tcg_type_env = type_env2 })
494 spliceInHsBootErr (SpliceDecl (L loc _), _)
495 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
498 Once we've typechecked the body of the module, we want to compare what
499 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
502 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
503 -- Compare the hi-boot file for this module (if there is one)
504 -- with the type environment we've just come up with
505 -- In the common case where there is no hi-boot file, the list
506 -- of boot_names is empty.
508 -- The bindings we return give bindings for the dfuns defined in the
509 -- hs-boot file, such as $fbEqT = $fEqT
512 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
513 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
514 tcg_type_env = local_type_env, tcg_exports = local_exports })
515 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
516 md_types = boot_type_env, md_exports = boot_exports })
517 | isHsBoot hs_src -- Current module is already a hs-boot file!
521 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
524 -- Check the exports of the boot module, one by one
525 ; mapM_ check_export boot_exports
527 -- Check instance declarations
528 ; mb_dfun_prs <- mapM check_inst boot_insts
529 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds,
530 tcg_type_env = extendTypeEnvWithIds local_type_env boot_dfuns }
531 dfun_prs = catMaybes mb_dfun_prs
532 boot_dfuns = map fst dfun_prs
533 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
534 | (boot_dfun, dfun) <- dfun_prs ]
536 -- Check for no family instances
537 ; unless (null boot_fam_insts) $
538 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
539 "instances in boot files yet...")
540 -- FIXME: Why? The actual comparison is not hard, but what would
541 -- be the equivalent to the dfun bindings returned for class
542 -- instances? We can't easily equate tycons...
546 check_export boot_avail -- boot_avail is exported by the boot iface
547 | name `elem` dfun_names = return ()
548 | isWiredInName name = return () -- No checking for wired-in names. In particular,
549 -- 'error' is handled by a rather gross hack
550 -- (see comments in GHC.Err.hs-boot)
552 -- Check that the actual module exports the same thing
553 | not (null missing_names)
554 = addErrTc (missingBootThing (head missing_names) "exported by")
556 -- If the boot module does not *define* the thing, we are done
557 -- (it simply re-exports it, and names match, so nothing further to do)
558 | isNothing mb_boot_thing = return ()
560 -- Check that the actual module also defines the thing, and
561 -- then compare the definitions
562 | Just real_thing <- lookupTypeEnv local_type_env name
563 = do { let boot_decl = tyThingToIfaceDecl (fromJust mb_boot_thing)
564 real_decl = tyThingToIfaceDecl real_thing
565 ; checkTc (checkBootDecl boot_decl real_decl)
566 (bootMisMatch real_thing boot_decl real_decl) }
567 -- The easiest way to check compatibility is to convert to
568 -- iface syntax, where we already have good comparison functions
571 = addErrTc (missingBootThing name "defined in")
573 name = availName boot_avail
574 mb_boot_thing = lookupTypeEnv boot_type_env name
575 missing_names = case lookupNameEnv local_export_env name of
577 Just avail -> availNames boot_avail `minusList` availNames avail
579 dfun_names = map getName boot_insts
581 local_export_env :: NameEnv AvailInfo
582 local_export_env = availsToNameEnv local_exports
584 check_inst :: Instance -> TcM (Maybe (Id, Id))
585 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
587 = case [dfun | inst <- local_insts,
588 let dfun = instanceDFunId inst,
589 idType dfun `tcEqType` boot_inst_ty ] of
590 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
591 (dfun:_) -> return (Just (local_boot_dfun, dfun))
593 boot_dfun = instanceDFunId boot_inst
594 boot_inst_ty = idType boot_dfun
595 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
599 missingBootThing thing what
600 = ppr thing <+> ptext SLIT("is exported by the hs-boot file, but not")
601 <+> text what <+> ptext SLIT("the module")
603 bootMisMatch thing boot_decl real_decl
604 = vcat [ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file"),
605 ptext SLIT("Main module:") <+> ppr real_decl,
606 ptext SLIT("Boot file: ") <+> ppr boot_decl]
610 2 (ptext SLIT("is defined in the hs-boot file, but not in the module itself"))
614 %************************************************************************
616 Type-checking the top level of a module
618 %************************************************************************
620 tcRnGroup takes a bunch of top-level source-code declarations, and
622 * gets supporting declarations from interface files
625 * and augments the TcGblEnv with the results
627 In Template Haskell it may be called repeatedly for each group of
628 declarations. It expects there to be an incoming TcGblEnv in the
629 monad; it augments it and returns the new TcGblEnv.
632 ------------------------------------------------
633 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
635 = do { -- Bring top level binders into scope
636 tcg_env <- importsFromLocalDecls group ;
637 setGblEnv tcg_env $ do {
639 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
641 -- Rename the source decls
642 (tcg_env, rn_decls) <- rnSrcDecls group ;
645 -- save the renamed syntax, if we want it
647 | Just grp <- tcg_rn_decls tcg_env
648 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
652 -- Dump trace of renaming part
653 rnDump (ppr rn_decls) ;
655 return (tcg_env', rn_decls)
658 ------------------------------------------------
659 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
660 tcTopSrcDecls boot_details
661 (HsGroup { hs_tyclds = tycl_decls,
662 hs_instds = inst_decls,
663 hs_derivds = deriv_decls,
664 hs_fords = foreign_decls,
665 hs_defds = default_decls,
666 hs_ruleds = rule_decls,
667 hs_valds = val_binds })
668 = do { -- Type-check the type and class decls, and all imported decls
669 -- The latter come in via tycl_decls
670 traceTc (text "Tc2") ;
672 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
673 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
674 -- an error we'd better stop now, to avoid a cascade
676 -- Make these type and class decls available to stuff slurped from interface files
677 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
680 setGblEnv tcg_env $ do {
681 -- Source-language instances, including derivings,
682 -- and import the supporting declarations
683 traceTc (text "Tc3") ;
684 (tcg_env, inst_infos, deriv_binds)
685 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
686 setGblEnv tcg_env $ do {
688 -- Foreign import declarations next. No zonking necessary
689 -- here; we can tuck them straight into the global environment.
690 traceTc (text "Tc4") ;
691 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
692 tcExtendGlobalValEnv fi_ids $ do {
694 -- Default declarations
695 traceTc (text "Tc4a") ;
696 default_tys <- tcDefaults default_decls ;
697 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
699 -- Value declarations next
700 -- We also typecheck any extra binds that came out
701 -- of the "deriving" process (deriv_binds)
702 traceTc (text "Tc5") ;
703 (tc_val_binds, tcl_env) <- tcTopBinds val_binds ;
704 setLclTypeEnv tcl_env $ do {
706 -- Now GHC-generated derived bindings and generics.
707 -- Do not generate warnings from compiler-generated code.
708 (tc_deriv_binds, tcl_env) <- discardWarnings $
709 tcTopBinds deriv_binds ;
711 -- Second pass over class and instance declarations,
712 traceTc (text "Tc6") ;
713 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $ tcInstDecls2 tycl_decls inst_infos ;
714 showLIE (text "after instDecls2") ;
717 -- They need to be zonked, so we return them
718 traceTc (text "Tc7") ;
719 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
722 rules <- tcRules rule_decls ;
725 traceTc (text "Tc7a") ;
726 tcg_env <- getGblEnv ;
727 let { all_binds = tc_val_binds `unionBags`
728 tc_deriv_binds `unionBags`
729 inst_binds `unionBags`
732 -- Extend the GblEnv with the (as yet un-zonked)
733 -- bindings, rules, foreign decls
734 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
735 tcg_rules = tcg_rules tcg_env ++ rules,
736 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
737 return (tcg_env', tcl_env)
742 %************************************************************************
746 %************************************************************************
749 checkMain :: TcM TcGblEnv
750 -- If we are in module Main, check that 'main' is defined.
752 = do { tcg_env <- getGblEnv ;
754 check_main dflags tcg_env
757 check_main dflags tcg_env
759 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
763 = do { mb_main <- lookupSrcOcc_maybe main_fn
764 -- Check that 'main' is in scope
765 -- It might be imported from another module!
767 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
772 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
773 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
774 -- :Main.main :: IO () = runMainIO main
776 ; (main_expr, ty) <- addErrCtxt mainCtxt $
777 setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
780 -- See Note [Root-main Id]
781 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
782 (mkVarOccFS FSLIT("main"))
783 (getSrcSpan main_name)
784 ; root_main_id = Id.mkExportedLocalId root_main_name ty
785 ; main_bind = noLoc (VarBind root_main_id main_expr) }
787 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
789 tcg_dus = tcg_dus tcg_env
790 `plusDU` usesOnly (unitFV main_name)
791 -- Record the use of 'main', so that we don't
792 -- complain about it being defined but not used
796 mod = tcg_mod tcg_env
797 main_mod = mainModIs dflags
798 main_is_flag = mainFunIs dflags
800 main_fn = case main_is_flag of
801 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
802 Nothing -> main_RDR_Unqual
804 complain_no_main | ghcLink dflags == LinkInMemory = return ()
805 | otherwise = failWithTc noMainMsg
806 -- In interactive mode, don't worry about the absence of 'main'
807 -- In other modes, fail altogether, so that we don't go on
808 -- and complain a second time when processing the export list.
810 mainCtxt = ptext SLIT("When checking the type of the") <+> pp_main_fn
811 noMainMsg = ptext SLIT("The") <+> pp_main_fn
812 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
813 pp_main_fn | isJust main_is_flag = ptext SLIT("main function") <+> quotes (ppr main_fn)
814 | otherwise = ptext SLIT("function") <+> quotes (ppr main_fn)
819 The function that the RTS invokes is always :Main.main, which we call
820 root_main_id. (Because GHC allows the user to have a module not
821 called Main as the main module, we can't rely on the main function
822 being called "Main.main". That's why root_main_id has a fixed module
825 This is unusual: it's a LocalId whose Name has a Module from another
826 module. Tiresomely, we must filter it out again in MkIface, les we
827 get two defns for 'main' in the interface file!
830 %*********************************************************
834 %*********************************************************
838 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
839 setInteractiveContext hsc_env icxt thing_inside
840 = let -- Initialise the tcg_inst_env with instances from all home modules.
841 -- This mimics the more selective call to hptInstances in tcRnModule.
842 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
844 updGblEnv (\env -> env {
845 tcg_rdr_env = ic_rn_gbl_env icxt,
846 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
847 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
851 tcExtendGhciEnv (ic_tmp_ids icxt) $
852 -- tcExtendGhciEnv does lots:
853 -- - it extends the local type env (tcl_env) with the given Ids,
854 -- - it extends the local rdr env (tcl_rdr) with the Names from
856 -- - it adds the free tyvars of the Ids to the tcl_tyvars
859 -- later ids in ic_tmp_ids must shadow earlier ones with the same
860 -- OccName, and tcExtendIdEnv implements this behaviour.
862 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
869 -> InteractiveContext
871 -> IO (Maybe ([Id], LHsExpr Id))
872 -- The returned [Id] is the list of new Ids bound by
873 -- this statement. It can be used to extend the
874 -- InteractiveContext via extendInteractiveContext.
876 -- The returned TypecheckedHsExpr is of type IO [ () ],
877 -- a list of the bound values, coerced to ().
879 tcRnStmt hsc_env ictxt rdr_stmt
880 = initTcPrintErrors hsc_env iNTERACTIVE $
881 setInteractiveContext hsc_env ictxt $ do {
883 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
884 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
885 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
887 rnDump (ppr rn_stmt) ;
889 -- The real work is done here
890 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
891 zonked_expr <- zonkTopLExpr tc_expr ;
892 zonked_ids <- zonkTopBndrs bound_ids ;
894 -- None of the Ids should be of unboxed type, because we
895 -- cast them all to HValues in the end!
896 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
898 traceTc (text "tcs 1") ;
899 let { -- (a) Make all the bound ids "global" ids, now that
900 -- they're notionally top-level bindings. This is
901 -- important: otherwise when we come to compile an expression
902 -- using these ids later, the byte code generator will consider
903 -- the occurrences to be free rather than global.
905 -- (b) Tidy their types; this is important, because :info may
906 -- ask to look at them, and :info expects the things it looks
907 -- up to have tidy types
908 global_ids = map globaliseAndTidy zonked_ids ;
910 {- ---------------------------------------------
911 At one stage I removed any shadowed bindings from the type_env;
912 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
913 However, with Template Haskell they aren't necessarily inaccessible. Consider this
915 Prelude> let f n = n * 2 :: Int
916 Prelude> fName <- runQ [| f |]
917 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
919 Prelude> let f n = n * 3 :: Int
920 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
921 In the last line we use 'fName', which resolves to the *first* 'f'
922 in scope. If we delete it from the type env, GHCi crashes because
923 it doesn't expect that.
925 Hence this code is commented out
927 -------------------------------------------------- -}
930 dumpOptTcRn Opt_D_dump_tc
931 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
932 text "Typechecked expr" <+> ppr zonked_expr]) ;
934 returnM (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
942 -- Give the Id a Global Name, and tidy its type
943 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
945 tidy_type = tidyTopType (idType id)
948 Here is the grand plan, implemented in tcUserStmt
950 What you type The IO [HValue] that hscStmt returns
951 ------------- ------------------------------------
952 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
955 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
958 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
959 [NB: result not printed] bindings: [it]
961 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
962 result showable) bindings: [it]
964 expr (of non-IO type,
965 result not showable) ==> error
969 ---------------------------
970 type PlanResult = ([Id], LHsExpr Id)
971 type Plan = TcM PlanResult
973 runPlans :: [Plan] -> TcM PlanResult
974 -- Try the plans in order. If one fails (by raising an exn), try the next.
975 -- If one succeeds, take it.
976 runPlans [] = panic "runPlans"
978 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
981 mkPlan :: LStmt Name -> TcM PlanResult
982 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
983 = do { uniq <- newUnique -- is treated very specially
984 ; let fresh_it = itName uniq
985 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
986 matches = [mkMatch [] expr emptyLocalBinds]
987 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
988 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
989 (HsVar bindIOName) noSyntaxExpr
990 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
991 (HsVar thenIOName) placeHolderType
994 -- [it <- e; print it] but not if it::()
996 -- [let it = e; print it]
997 ; runPlans [ -- Plan A
998 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
999 ; it_ty <- zonkTcType (idType it_id)
1000 ; ifM (isUnitTy it_ty) failM
1003 -- Plan B; a naked bind statment
1004 tcGhciStmts [bind_stmt],
1006 -- Plan C; check that the let-binding is typeable all by itself.
1007 -- If not, fail; if so, try to print it.
1008 -- The two-step process avoids getting two errors: one from
1009 -- the expression itself, and one from the 'print it' part
1010 -- This two-step story is very clunky, alas
1011 do { checkNoErrs (tcGhciStmts [let_stmt])
1012 --- checkNoErrs defeats the error recovery of let-bindings
1013 ; tcGhciStmts [let_stmt, print_it] }
1016 mkPlan stmt@(L loc (BindStmt {}))
1017 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1018 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1019 (HsVar thenIOName) placeHolderType
1021 ; print_bind_result <- doptM Opt_PrintBindResult
1022 ; let print_plan = do
1023 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1024 ; v_ty <- zonkTcType (idType v_id)
1025 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
1029 -- [stmt; print v] but not if v::()
1031 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1032 [tcGhciStmts [stmt]])
1036 = tcGhciStmts [stmt]
1038 ---------------------------
1039 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1041 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1042 ret_id <- tcLookupId returnIOName ; -- return @ IO
1044 io_ty = mkTyConApp ioTyCon [] ;
1045 ret_ty = mkListTy unitTy ;
1046 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1047 tc_io_stmts stmts = tcStmts DoExpr (tcDoStmt io_ty) stmts
1048 (emptyRefinement, io_ret_ty) ;
1050 names = map unLoc (collectLStmtsBinders stmts) ;
1052 -- mk_return builds the expression
1053 -- returnIO @ [()] [coerce () x, .., coerce () z]
1055 -- Despite the inconvenience of building the type applications etc,
1056 -- this *has* to be done in type-annotated post-typecheck form
1057 -- because we are going to return a list of *polymorphic* values
1058 -- coerced to type (). If we built a *source* stmt
1059 -- return [coerce x, ..., coerce z]
1060 -- then the type checker would instantiate x..z, and we wouldn't
1061 -- get their *polymorphic* values. (And we'd get ambiguity errs
1062 -- if they were overloaded, since they aren't applied to anything.)
1063 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1064 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1065 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1069 -- OK, we're ready to typecheck the stmts
1070 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1071 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1072 mappM tcLookupId names ;
1073 -- Look up the names right in the middle,
1074 -- where they will all be in scope
1076 -- Simplify the context
1077 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1078 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1079 -- checkNoErrs ensures that the plan fails if context redn fails
1081 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1082 return (ids, mkHsDictLet const_binds $
1083 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1088 tcRnExpr just finds the type of an expression
1092 -> InteractiveContext
1095 tcRnExpr hsc_env ictxt rdr_expr
1096 = initTcPrintErrors hsc_env iNTERACTIVE $
1097 setInteractiveContext hsc_env ictxt $ do {
1099 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1102 -- Now typecheck the expression;
1103 -- it might have a rank-2 type (e.g. :t runST)
1104 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1105 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1106 tcSimplifyInteractive lie_top ;
1108 let { all_expr_ty = mkForAllTys qtvs $
1109 mkFunTys (map (idType . instToId) dict_insts) $
1111 zonkTcType all_expr_ty
1114 smpl_doc = ptext SLIT("main expression")
1117 tcRnType just finds the kind of a type
1121 -> InteractiveContext
1124 tcRnType hsc_env ictxt rdr_type
1125 = initTcPrintErrors hsc_env iNTERACTIVE $
1126 setInteractiveContext hsc_env ictxt $ do {
1128 rn_type <- rnLHsType doc rdr_type ;
1131 -- Now kind-check the type
1132 (ty', kind) <- kcHsType rn_type ;
1136 doc = ptext SLIT("In GHCi input")
1142 %************************************************************************
1144 More GHCi stuff, to do with browsing and getting info
1146 %************************************************************************
1150 -- ASSUMES that the module is either in the HomePackageTable or is
1151 -- a package module with an interface on disk. If neither of these is
1152 -- true, then the result will be an error indicating the interface
1153 -- could not be found.
1154 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1155 getModuleExports hsc_env mod
1158 checkMods = ic_toplev_scope ic ++ ic_exports ic
1160 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1162 -- Get the export avail info and also load all orphan and family-instance
1163 -- modules. Finally, check that the family instances of all modules in the
1164 -- interactive context are consistent (these modules are in the second
1166 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1167 tcGetModuleExports mod directlyImpMods
1168 = do { let doc = ptext SLIT("context for compiling statements")
1169 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1171 -- Load any orphan-module and family instance-module
1172 -- interfaces, so their instances are visible.
1173 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1174 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1176 -- Check that the family instances of all directly loaded
1177 -- modules are consistent.
1178 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1180 ; ifaceExportNames (mi_exports iface)
1183 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1184 tcRnLookupRdrName hsc_env rdr_name
1185 = initTcPrintErrors hsc_env iNTERACTIVE $
1186 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1187 lookup_rdr_name rdr_name
1189 lookup_rdr_name rdr_name = do {
1190 -- If the identifier is a constructor (begins with an
1191 -- upper-case letter), then we need to consider both
1192 -- constructor and type class identifiers.
1193 let { rdr_names = dataTcOccs rdr_name } ;
1195 -- results :: [Either Messages Name]
1196 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1198 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1199 -- The successful lookups will be (Just name)
1200 let { (warns_s, good_names) = unzip [ (msgs, name)
1201 | (msgs, Just name) <- results] ;
1202 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1204 -- Fail if nothing good happened, else add warnings
1205 if null good_names then
1206 -- No lookup succeeded, so
1207 -- pick the first error message and report it
1208 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1209 -- while the other is "X is not in scope",
1210 -- we definitely want the former; but we might pick the latter
1211 do { addMessages (head errs_s) ; failM }
1212 else -- Add deprecation warnings
1213 mapM_ addMessages warns_s ;
1218 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1219 tcRnLookupName hsc_env name
1220 = initTcPrintErrors hsc_env iNTERACTIVE $
1221 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1222 tcRnLookupName' name
1224 -- To look up a name we have to look in the local environment (tcl_lcl)
1225 -- as well as the global environment, which is what tcLookup does.
1226 -- But we also want a TyThing, so we have to convert:
1228 tcRnLookupName' :: Name -> TcRn TyThing
1229 tcRnLookupName' name = do
1230 tcthing <- tcLookup name
1232 AGlobal thing -> return thing
1233 ATcId{tct_id=id} -> return (AnId id)
1234 _ -> panic "tcRnLookupName'"
1236 tcRnGetInfo :: HscEnv
1238 -> IO (Maybe (TyThing, Fixity, [Instance]))
1240 -- Used to implemnent :info in GHCi
1242 -- Look up a RdrName and return all the TyThings it might be
1243 -- A capitalised RdrName is given to us in the DataName namespace,
1244 -- but we want to treat it as *both* a data constructor
1245 -- *and* as a type or class constructor;
1246 -- hence the call to dataTcOccs, and we return up to two results
1247 tcRnGetInfo hsc_env name
1248 = initTcPrintErrors hsc_env iNTERACTIVE $
1249 let ictxt = hsc_IC hsc_env in
1250 setInteractiveContext hsc_env ictxt $ do
1252 -- Load the interface for all unqualified types and classes
1253 -- That way we will find all the instance declarations
1254 -- (Packages have not orphan modules, and we assume that
1255 -- in the home package all relevant modules are loaded.)
1256 loadUnqualIfaces ictxt
1258 thing <- tcRnLookupName' name
1259 fixity <- lookupFixityRn name
1260 ispecs <- lookupInsts thing
1261 return (thing, fixity, ispecs)
1263 lookupInsts :: TyThing -> TcM [Instance]
1264 lookupInsts (AClass cls)
1265 = do { inst_envs <- tcGetInstEnvs
1266 ; return (classInstances inst_envs cls) }
1268 lookupInsts (ATyCon tc)
1269 = do { eps <- getEps -- Load all instances for all classes that are
1270 -- in the type environment (which are all the ones
1271 -- we've seen in any interface file so far)
1272 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1274 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1275 , let dfun = instanceDFunId ispec
1278 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1279 tc_name = tyConName tc
1281 lookupInsts other = return []
1283 loadUnqualIfaces :: InteractiveContext -> TcM ()
1284 -- Load the home module for everything that is in scope unqualified
1285 -- This is so that we can accurately report the instances for
1287 loadUnqualIfaces ictxt
1289 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1291 unqual_mods = [ nameModule name
1292 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1293 let name = gre_name gre,
1294 not (isInternalName name),
1295 isTcOcc (nameOccName name), -- Types and classes only
1296 unQualOK gre ] -- In scope unqualified
1297 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1301 %************************************************************************
1305 %************************************************************************
1308 rnDump :: SDoc -> TcRn ()
1309 -- Dump, with a banner, if -ddump-rn
1310 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1312 tcDump :: TcGblEnv -> TcRn ()
1314 = do { dflags <- getDOpts ;
1316 -- Dump short output if -ddump-types or -ddump-tc
1317 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1318 (dumpTcRn short_dump) ;
1320 -- Dump bindings if -ddump-tc
1321 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1324 short_dump = pprTcGblEnv env
1325 full_dump = pprLHsBinds (tcg_binds env)
1326 -- NB: foreign x-d's have undefined's in their types;
1327 -- hence can't show the tc_fords
1330 = do { dflags <- getDOpts ;
1331 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1332 (dumpTcRn (pprModGuts mod_guts)) ;
1334 -- Dump bindings if -ddump-tc
1335 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1337 full_dump = pprCoreBindings (mg_binds mod_guts)
1339 -- It's unpleasant having both pprModGuts and pprModDetails here
1340 pprTcGblEnv :: TcGblEnv -> SDoc
1341 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1343 tcg_fam_insts = fam_insts,
1345 tcg_imports = imports })
1346 = vcat [ ppr_types insts type_env
1347 , ppr_tycons fam_insts type_env
1349 , ppr_fam_insts fam_insts
1350 , vcat (map ppr rules)
1351 , ppr_gen_tycons (typeEnvTyCons type_env)
1352 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1353 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1355 pprModGuts :: ModGuts -> SDoc
1356 pprModGuts (ModGuts { mg_types = type_env,
1358 = vcat [ ppr_types [] type_env,
1361 ppr_types :: [Instance] -> TypeEnv -> SDoc
1362 ppr_types insts type_env
1363 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1365 dfun_ids = map instanceDFunId insts
1366 ids = [id | id <- typeEnvIds type_env, want_sig id]
1367 want_sig id | opt_PprStyle_Debug = True
1368 | otherwise = isLocalId id &&
1369 isExternalName (idName id) &&
1370 not (id `elem` dfun_ids)
1371 -- isLocalId ignores data constructors, records selectors etc.
1372 -- The isExternalName ignores local dictionary and method bindings
1373 -- that the type checker has invented. Top-level user-defined things
1374 -- have External names.
1376 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1377 ppr_tycons fam_insts type_env
1378 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1380 fi_tycons = map famInstTyCon fam_insts
1381 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1382 want_tycon tycon | opt_PprStyle_Debug = True
1383 | otherwise = not (isImplicitTyCon tycon) &&
1384 isExternalName (tyConName tycon) &&
1385 not (tycon `elem` fi_tycons)
1387 ppr_insts :: [Instance] -> SDoc
1388 ppr_insts [] = empty
1389 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1391 ppr_fam_insts :: [FamInst] -> SDoc
1392 ppr_fam_insts [] = empty
1393 ppr_fam_insts fam_insts =
1394 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1396 ppr_sigs :: [Var] -> SDoc
1398 -- Print type signatures; sort by OccName
1399 = vcat (map ppr_sig (sortLe le_sig ids))
1401 le_sig id1 id2 = getOccName id1 <= getOccName id2
1402 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1404 ppr_tydecls :: [TyCon] -> SDoc
1406 -- Print type constructor info; sort by OccName
1407 = vcat (map ppr_tycon (sortLe le_sig tycons))
1409 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1411 | isCoercionTyCon tycon = ptext SLIT("coercion") <+> ppr tycon
1412 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1414 ppr_rules :: [CoreRule] -> SDoc
1415 ppr_rules [] = empty
1416 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1417 nest 4 (pprRules rs),
1420 ppr_gen_tycons [] = empty
1421 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1422 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]