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 )
89 import {- Kind parts of -} Type
98 import Control.Monad ( unless )
99 import Data.Maybe ( isJust )
100 import Foreign.Ptr ( Ptr )
106 %************************************************************************
108 Typecheck and rename a module
110 %************************************************************************
116 -> Bool -- True <=> save renamed syntax
117 -> Located (HsModule RdrName)
118 -> IO (Messages, Maybe TcGblEnv)
120 tcRnModule hsc_env hsc_src save_rn_syntax
121 (L loc (HsModule maybe_mod export_ies
122 import_decls local_decls mod_deprec _
123 module_info maybe_doc))
124 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
126 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
127 this_mod = case maybe_mod of
128 Nothing -> mAIN -- 'module M where' is omitted
129 Just (L _ mod) -> mkModule this_pkg mod } ;
132 initTc hsc_env hsc_src save_rn_syntax this_mod $
134 do { -- Deal with imports;
135 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
136 setGblEnv tcg_env $ do {
138 -- Load the hi-boot interface for this module, if any
139 -- We do this now so that the boot_names can be passed
140 -- to tcTyAndClassDecls, because the boot_names are
141 -- automatically considered to be loop breakers
143 -- Do this *after* tcRnImports, so that we know whether
144 -- a module that we import imports us; and hence whether to
145 -- look for a hi-boot file
146 boot_iface <- tcHiBootIface hsc_src this_mod ;
148 -- Rename and type check the declarations
149 traceRn (text "rn1a") ;
150 tcg_env <- if isHsBoot hsc_src then
151 tcRnHsBootDecls local_decls
153 tcRnSrcDecls boot_iface local_decls ;
154 setGblEnv tcg_env $ do {
156 -- Report the use of any deprecated things
157 -- We do this *before* processsing the export list so
158 -- that we don't bleat about re-exporting a deprecated
159 -- thing (especially via 'module Foo' export item)
160 -- That is, only uses in the *body* of the module are complained about
161 traceRn (text "rn3") ;
162 failIfErrsM ; -- finishDeprecations crashes sometimes
163 -- as a result of typechecker repairs (e.g. unboundNames)
164 tcg_env <- finishDeprecations (hsc_dflags hsc_env) mod_deprec tcg_env ;
166 -- Process the export list
167 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
168 traceRn (text "rn4") ;
170 -- Compare the hi-boot iface (if any) with the real thing
171 -- Must be done after processing the exports
172 tcg_env <- checkHiBootIface tcg_env boot_iface ;
174 -- Make the new type env available to stuff slurped from interface files
175 -- Must do this after checkHiBootIface, because the latter might add new
176 -- bindings for boot_dfuns, which may be mentioned in imported unfoldings
177 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
179 -- Rename the Haddock documentation
180 tcg_env <- rnHaddock module_info maybe_doc tcg_env ;
182 -- Report unused names
183 reportUnusedNames export_ies tcg_env ;
185 -- Dump output and return
192 %************************************************************************
196 %************************************************************************
199 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
200 tcRnImports hsc_env this_mod import_decls
201 = do { (rn_imports, rdr_env, imports) <- rnImports import_decls ;
203 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
204 ; dep_mods = imp_dep_mods imports
206 -- We want instance declarations from all home-package
207 -- modules below this one, including boot modules, except
208 -- ourselves. The 'except ourselves' is so that we don't
209 -- get the instances from this module's hs-boot file
210 ; want_instances :: ModuleName -> Bool
211 ; want_instances mod = mod `elemUFM` dep_mods
212 && mod /= moduleName this_mod
213 ; home_insts = hptInstances hsc_env want_instances
216 -- Record boot-file info in the EPS, so that it's
217 -- visible to loadHiBootInterface in tcRnSrcDecls,
218 -- and any other incrementally-performed imports
219 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
221 -- Update the gbl env
222 ; updGblEnv ( \ gbl ->
223 gbl { tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
224 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
225 tcg_rn_imports = fmap (const rn_imports) (tcg_rn_imports gbl),
226 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts
229 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
230 -- Fail if there are any errors so far
231 -- The error printing (if needed) takes advantage
232 -- of the tcg_env we have now set
233 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
236 -- Load any orphan-module and family instance-module
237 -- interfaces, so that their rules and instance decls will be
239 ; loadOrphanModules (imp_orphs imports) False
240 ; loadOrphanModules (imp_finsts imports) True
242 -- Check type-familily consistency
243 ; traceRn (text "rn1: checking family instance consistency")
244 ; let { dir_imp_mods = map (\ (mod, _, _) -> mod)
248 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
254 %************************************************************************
256 Type-checking external-core modules
258 %************************************************************************
261 tcRnExtCore :: HscEnv
263 -> IO (Messages, Maybe ModGuts)
264 -- Nothing => some error occurred
266 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
267 -- The decls are IfaceDecls; all names are original names
268 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
270 initTc hsc_env ExtCoreFile False this_mod $ do {
272 let { ldecls = map noLoc decls } ;
274 -- Deal with the type declarations; first bring their stuff
275 -- into scope, then rname them, then type check them
276 tcg_env <- importsFromLocalDecls (mkFakeGroup ldecls) ;
278 setGblEnv tcg_env $ do {
280 rn_decls <- rnTyClDecls ldecls ;
283 -- Dump trace of renaming part
284 rnDump (ppr rn_decls) ;
286 -- Typecheck them all together so that
287 -- any mutually recursive types are done right
288 tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails rn_decls) ;
289 -- Make the new type env available to stuff slurped from interface files
291 setGblEnv tcg_env $ do {
293 -- Now the core bindings
294 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
298 bndrs = bindersOfBinds core_binds ;
299 my_exports = map (Avail . idName) bndrs ;
300 -- ToDo: export the data types also?
302 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
304 mod_guts = ModGuts { mg_module = this_mod,
306 mg_usages = [], -- ToDo: compute usage
307 mg_dir_imps = [], -- ??
308 mg_deps = noDependencies, -- ??
309 mg_exports = my_exports,
310 mg_types = final_type_env,
311 mg_insts = tcg_insts tcg_env,
312 mg_fam_insts = tcg_fam_insts tcg_env,
313 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
315 mg_binds = core_binds,
318 mg_rdr_env = emptyGlobalRdrEnv,
319 mg_fix_env = emptyFixityEnv,
320 mg_deprecs = NoDeprecs,
321 mg_foreign = NoStubs,
322 mg_hpc_info = noHpcInfo,
323 mg_modBreaks = emptyModBreaks
326 tcCoreDump mod_guts ;
331 mkFakeGroup decls -- Rather clumsy; lots of unused fields
332 = emptyRdrGroup { hs_tyclds = decls }
336 %************************************************************************
338 Type-checking the top level of a module
340 %************************************************************************
343 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
344 -- Returns the variables free in the decls
345 -- Reason: solely to report unused imports and bindings
346 tcRnSrcDecls boot_iface decls
347 = do { -- Do all the declarations
348 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
350 -- Finish simplifying class constraints
352 -- tcSimplifyTop deals with constant or ambiguous InstIds.
353 -- How could there be ambiguous ones? They can only arise if a
354 -- top-level decl falls under the monomorphism restriction
355 -- and no subsequent decl instantiates its type.
357 -- We do this after checkMain, so that we use the type info
358 -- thaat checkMain adds
360 -- We do it with both global and local env in scope:
361 -- * the global env exposes the instances to tcSimplifyTop
362 -- * the local env exposes the local Ids to tcSimplifyTop,
363 -- so that we get better error messages (monomorphism restriction)
364 traceTc (text "Tc8") ;
365 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
367 -- Backsubstitution. This must be done last.
368 -- Even tcSimplifyTop may do some unification.
369 traceTc (text "Tc9") ;
370 let { (tcg_env, _) = tc_envs
371 ; TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
372 tcg_rules = rules, tcg_fords = fords } = tcg_env
373 ; all_binds = binds `unionBags` inst_binds } ;
375 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
377 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
378 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
381 tcg_fords = fords' } } ;
383 return (tcg_env' { tcg_binds = tcg_binds tcg_env' })
386 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
387 -- Loops around dealing with each top level inter-splice group
388 -- in turn, until it's dealt with the entire module
389 tc_rn_src_decls boot_details ds
390 = do { let { (first_group, group_tail) = findSplice ds } ;
391 -- If ds is [] we get ([], Nothing)
393 -- Deal with decls up to, but not including, the first splice
394 (tcg_env, rn_decls) <- checkNoErrs $ rnTopSrcDecls first_group ;
395 -- checkNoErrs: stop if renaming fails
397 (tcg_env, tcl_env) <- setGblEnv tcg_env $
398 tcTopSrcDecls boot_details rn_decls ;
400 -- If there is no splice, we're nearly done
401 setEnvs (tcg_env, tcl_env) $
403 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
404 return (tcg_env, tcl_env)
407 -- If there's a splice, we must carry on
408 Just (SpliceDecl splice_expr, rest_ds) -> do {
410 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
413 -- Rename the splice expression, and get its supporting decls
414 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
415 -- checkNoErrs: don't typecheck if renaming failed
416 rnDump (ppr rn_splice_expr) ;
418 -- Execute the splice
419 spliced_decls <- tcSpliceDecls rn_splice_expr ;
421 -- Glue them on the front of the remaining decls and loop
422 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
423 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
428 %************************************************************************
430 Compiling hs-boot source files, and
431 comparing the hi-boot interface with the real thing
433 %************************************************************************
436 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
437 tcRnHsBootDecls decls
438 = do { let { (first_group, group_tail) = findSplice decls }
441 Just stuff -> spliceInHsBootErr stuff
444 -- Rename the declarations
445 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
446 ; setGblEnv tcg_env $ do {
448 -- Todo: check no foreign decls, no rules, no default decls
450 -- Typecheck type/class decls
451 ; traceTc (text "Tc2")
452 ; let tycl_decls = hs_tyclds rn_group
453 ; tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails tycl_decls)
454 ; setGblEnv tcg_env $ do {
456 -- Typecheck instance decls
457 ; traceTc (text "Tc3")
458 ; (tcg_env, inst_infos, _deriv_binds)
459 <- tcInstDecls1 tycl_decls (hs_instds rn_group) (hs_derivds rn_group)
460 ; setGblEnv tcg_env $ do {
462 -- Typecheck value declarations
463 ; traceTc (text "Tc5")
464 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
467 -- No simplification or zonking to do
468 ; traceTc (text "Tc7a")
469 ; gbl_env <- getGblEnv
471 -- Make the final type-env
472 -- Include the dfun_ids so that their type sigs
473 -- are written into the interface file
474 ; let { type_env0 = tcg_type_env gbl_env
475 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
476 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
477 ; dfun_ids = map iDFunId inst_infos }
478 ; return (gbl_env { tcg_type_env = type_env2 })
481 spliceInHsBootErr (SpliceDecl (L loc _), _)
482 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
485 Once we've typechecked the body of the module, we want to compare what
486 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
489 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
490 -- Compare the hi-boot file for this module (if there is one)
491 -- with the type environment we've just come up with
492 -- In the common case where there is no hi-boot file, the list
493 -- of boot_names is empty.
495 -- The bindings we return give bindings for the dfuns defined in the
496 -- hs-boot file, such as $fbEqT = $fEqT
499 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
500 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
501 tcg_type_env = local_type_env, tcg_exports = local_exports })
502 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
503 md_types = boot_type_env, md_exports = boot_exports })
504 | isHsBoot hs_src -- Current module is already a hs-boot file!
508 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
511 -- Check the exports of the boot module, one by one
512 ; mapM_ check_export boot_exports
514 -- Check instance declarations
515 ; mb_dfun_prs <- mapM check_inst boot_insts
516 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds,
517 tcg_type_env = extendTypeEnvWithIds local_type_env boot_dfuns }
518 dfun_prs = catMaybes mb_dfun_prs
519 boot_dfuns = map fst dfun_prs
520 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
521 | (boot_dfun, dfun) <- dfun_prs ]
523 -- Check for no family instances
524 ; unless (null boot_fam_insts) $
525 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
526 "instances in boot files yet...")
527 -- FIXME: Why? The actual comparison is not hard, but what would
528 -- be the equivalent to the dfun bindings returned for class
529 -- instances? We can't easily equate tycons...
533 check_export boot_avail -- boot_avail is exported by the boot iface
534 | name `elem` dfun_names = return ()
535 | isWiredInName name = return () -- No checking for wired-in names. In particular,
536 -- 'error' is handled by a rather gross hack
537 -- (see comments in GHC.Err.hs-boot)
539 -- Check that the actual module exports the same thing
540 | not (null missing_names)
541 = addErrTc (missingBootThing (head missing_names) "exported by")
543 -- If the boot module does not *define* the thing, we are done
544 -- (it simply re-exports it, and names match, so nothing further to do)
545 | isNothing mb_boot_thing = return ()
547 -- Check that the actual module also defines the thing, and
548 -- then compare the definitions
549 | Just real_thing <- lookupTypeEnv local_type_env name
550 = do { let boot_decl = tyThingToIfaceDecl (fromJust mb_boot_thing)
551 real_decl = tyThingToIfaceDecl real_thing
552 ; checkTc (checkBootDecl boot_decl real_decl)
553 (bootMisMatch real_thing boot_decl real_decl) }
554 -- The easiest way to check compatibility is to convert to
555 -- iface syntax, where we already have good comparison functions
558 = addErrTc (missingBootThing name "defined in")
560 name = availName boot_avail
561 mb_boot_thing = lookupTypeEnv boot_type_env name
562 missing_names = case lookupNameEnv local_export_env name of
564 Just avail -> availNames boot_avail `minusList` availNames avail
566 dfun_names = map getName boot_insts
568 local_export_env :: NameEnv AvailInfo
569 local_export_env = availsToNameEnv local_exports
571 check_inst :: Instance -> TcM (Maybe (Id, Id))
572 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
574 = case [dfun | inst <- local_insts,
575 let dfun = instanceDFunId inst,
576 idType dfun `tcEqType` boot_inst_ty ] of
577 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
578 (dfun:_) -> return (Just (local_boot_dfun, dfun))
580 boot_dfun = instanceDFunId boot_inst
581 boot_inst_ty = idType boot_dfun
582 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
586 missingBootThing thing what
587 = ppr thing <+> ptext SLIT("is exported by the hs-boot file, but not")
588 <+> text what <+> ptext SLIT("the module")
590 bootMisMatch thing boot_decl real_decl
591 = vcat [ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file"),
592 ptext SLIT("Main module:") <+> ppr real_decl,
593 ptext SLIT("Boot file: ") <+> ppr boot_decl]
597 2 (ptext SLIT("is defined in the hs-boot file, but not in the module itself"))
601 %************************************************************************
603 Type-checking the top level of a module
605 %************************************************************************
607 tcRnGroup takes a bunch of top-level source-code declarations, and
609 * gets supporting declarations from interface files
612 * and augments the TcGblEnv with the results
614 In Template Haskell it may be called repeatedly for each group of
615 declarations. It expects there to be an incoming TcGblEnv in the
616 monad; it augments it and returns the new TcGblEnv.
619 ------------------------------------------------
620 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
622 = do { -- Bring top level binders into scope
623 tcg_env <- importsFromLocalDecls group ;
624 setGblEnv tcg_env $ do {
626 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
628 -- Rename the source decls
629 (tcg_env, rn_decls) <- rnSrcDecls group ;
632 -- save the renamed syntax, if we want it
634 | Just grp <- tcg_rn_decls tcg_env
635 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
639 -- Dump trace of renaming part
640 rnDump (ppr rn_decls) ;
642 return (tcg_env', rn_decls)
645 ------------------------------------------------
646 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
647 tcTopSrcDecls boot_details
648 (HsGroup { hs_tyclds = tycl_decls,
649 hs_instds = inst_decls,
650 hs_derivds = deriv_decls,
651 hs_fords = foreign_decls,
652 hs_defds = default_decls,
653 hs_ruleds = rule_decls,
654 hs_valds = val_binds })
655 = do { -- Type-check the type and class decls, and all imported decls
656 -- The latter come in via tycl_decls
657 traceTc (text "Tc2") ;
659 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
660 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
661 -- an error we'd better stop now, to avoid a cascade
663 -- Make these type and class decls available to stuff slurped from interface files
664 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
667 setGblEnv tcg_env $ do {
668 -- Source-language instances, including derivings,
669 -- and import the supporting declarations
670 traceTc (text "Tc3") ;
671 (tcg_env, inst_infos, deriv_binds)
672 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
673 setGblEnv tcg_env $ do {
675 -- Foreign import declarations next. No zonking necessary
676 -- here; we can tuck them straight into the global environment.
677 traceTc (text "Tc4") ;
678 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
679 tcExtendGlobalValEnv fi_ids $ do {
681 -- Default declarations
682 traceTc (text "Tc4a") ;
683 default_tys <- tcDefaults default_decls ;
684 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
686 -- Value declarations next
687 -- We also typecheck any extra binds that came out
688 -- of the "deriving" process (deriv_binds)
689 traceTc (text "Tc5") ;
690 (tc_val_binds, tcl_env) <- tcTopBinds val_binds ;
691 setLclTypeEnv tcl_env $ do {
693 -- Now GHC-generated derived bindings and generics
694 -- Do not generate warnings from compiler-generated code
695 (tc_deriv_binds, tcl_env) <- discardWarnings $ setOptM Opt_GlasgowExts $
696 tcTopBinds deriv_binds ;
698 -- Second pass over class and instance declarations,
699 traceTc (text "Tc6") ;
700 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $ tcInstDecls2 tycl_decls inst_infos ;
701 showLIE (text "after instDecls2") ;
704 -- They need to be zonked, so we return them
705 traceTc (text "Tc7") ;
706 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
709 rules <- tcRules rule_decls ;
712 traceTc (text "Tc7a") ;
713 tcg_env <- getGblEnv ;
714 let { all_binds = tc_val_binds `unionBags`
715 tc_deriv_binds `unionBags`
716 inst_binds `unionBags`
719 -- Extend the GblEnv with the (as yet un-zonked)
720 -- bindings, rules, foreign decls
721 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
722 tcg_rules = tcg_rules tcg_env ++ rules,
723 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
724 return (tcg_env', tcl_env)
729 %************************************************************************
733 %************************************************************************
736 checkMain :: TcM TcGblEnv
737 -- If we are in module Main, check that 'main' is defined.
739 = do { tcg_env <- getGblEnv ;
741 let { main_mod = mainModIs dflags ;
742 main_fn = case mainFunIs dflags of {
743 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn)) ;
744 Nothing -> main_RDR_Unqual } } ;
746 check_main dflags tcg_env main_mod main_fn
750 check_main dflags tcg_env main_mod main_fn
752 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
756 = addErrCtxt mainCtxt $
757 do { mb_main <- lookupSrcOcc_maybe main_fn
758 -- Check that 'main' is in scope
759 -- It might be imported from another module!
761 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
765 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
766 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
767 -- :Main.main :: IO () = runMainIO main
769 ; (main_expr, ty) <- setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
772 -- See Note [Root-main Id]
773 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
774 (mkVarOccFS FSLIT("main"))
775 (getSrcLoc main_name)
776 ; root_main_id = Id.mkExportedLocalId root_main_name ty
777 ; main_bind = noLoc (VarBind root_main_id main_expr) }
779 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
781 tcg_dus = tcg_dus tcg_env
782 `plusDU` usesOnly (unitFV main_name)
783 -- Record the use of 'main', so that we don't
784 -- complain about it being defined but not used
788 mod = tcg_mod tcg_env
790 complain_no_main | ghcLink dflags == LinkInMemory = return ()
791 | otherwise = failWithTc noMainMsg
792 -- In interactive mode, don't worry about the absence of 'main'
793 -- In other modes, fail altogether, so that we don't go on
794 -- and complain a second time when processing the export list.
796 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
797 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
798 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
803 The function that the RTS invokes is always :Main.main, which we call
804 root_main_id. (Because GHC allows the user to have a module not
805 called Main as the main module, we can't rely on the main function
806 being called "Main.main". That's why root_main_id has a fixed module
809 This is unusual: it's a LocalId whose Name has a Module from another
810 module. Tiresomely, we must filter it out again in MkIface, les we
811 get two defns for 'main' in the interface file!
814 %*********************************************************
818 %*********************************************************
822 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
823 setInteractiveContext hsc_env icxt thing_inside
825 -- Initialise the tcg_inst_env with instances
826 -- from all home modules. This mimics the more selective
827 -- call to hptInstances in tcRnModule
828 dfuns = hptInstances hsc_env (\mod -> True)
830 updGblEnv (\env -> env {
831 tcg_rdr_env = ic_rn_gbl_env icxt,
832 tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
835 tcExtendIdEnv (reverse (ic_tmp_ids icxt)) $
836 -- tcExtendIdEnv does lots:
837 -- - it extends the local type env (tcl_env) with the given Ids,
838 -- - it extends the local rdr env (tcl_rdr) with the Names from
840 -- - it adds the free tyvars of the Ids to the tcl_tyvars
843 -- earlier ids in ic_tmp_ids must shadow later ones with the same
844 -- OccName, but tcExtendIdEnv has the opposite behaviour, hence the
847 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
854 -> InteractiveContext
856 -> IO (Maybe ([Id], LHsExpr Id))
857 -- The returned [Id] is the list of new Ids bound by
858 -- this statement. It can be used to extend the
859 -- InteractiveContext via extendInteractiveContext.
861 -- The returned TypecheckedHsExpr is of type IO [ () ],
862 -- a list of the bound values, coerced to ().
864 tcRnStmt hsc_env ictxt rdr_stmt
865 = initTcPrintErrors hsc_env iNTERACTIVE $
866 setInteractiveContext hsc_env ictxt $ do {
868 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
869 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
870 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
873 -- The real work is done here
874 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
875 zonked_expr <- zonkTopLExpr tc_expr ;
876 zonked_ids <- zonkTopBndrs bound_ids ;
878 -- None of the Ids should be of unboxed type, because we
879 -- cast them all to HValues in the end!
880 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
882 traceTc (text "tcs 1") ;
883 let { -- (a) Make all the bound ids "global" ids, now that
884 -- they're notionally top-level bindings. This is
885 -- important: otherwise when we come to compile an expression
886 -- using these ids later, the byte code generator will consider
887 -- the occurrences to be free rather than global.
889 -- (b) Tidy their types; this is important, because :info may
890 -- ask to look at them, and :info expects the things it looks
891 -- up to have tidy types
892 global_ids = map globaliseAndTidy zonked_ids ;
894 {- ---------------------------------------------
895 At one stage I removed any shadowed bindings from the type_env;
896 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
897 However, with Template Haskell they aren't necessarily inaccessible. Consider this
899 Prelude> let f n = n * 2 :: Int
900 Prelude> fName <- runQ [| f |]
901 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
903 Prelude> let f n = n * 3 :: Int
904 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
905 In the last line we use 'fName', which resolves to the *first* 'f'
906 in scope. If we delete it from the type env, GHCi crashes because
907 it doesn't expect that.
909 Hence this code is commented out
911 -------------------------------------------------- -}
914 dumpOptTcRn Opt_D_dump_tc
915 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
916 text "Typechecked expr" <+> ppr zonked_expr]) ;
918 returnM (global_ids, zonked_expr)
921 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
922 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
924 globaliseAndTidy :: Id -> Id
926 -- Give the Id a Global Name, and tidy its type
927 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
929 tidy_type = tidyTopType (idType id)
932 Here is the grand plan, implemented in tcUserStmt
934 What you type The IO [HValue] that hscStmt returns
935 ------------- ------------------------------------
936 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
939 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
942 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
943 [NB: result not printed] bindings: [it]
945 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
946 result showable) bindings: [it]
948 expr (of non-IO type,
949 result not showable) ==> error
953 ---------------------------
954 type PlanResult = ([Id], LHsExpr Id)
955 type Plan = TcM PlanResult
957 runPlans :: [Plan] -> TcM PlanResult
958 -- Try the plans in order. If one fails (by raising an exn), try the next.
959 -- If one succeeds, take it.
960 runPlans [] = panic "runPlans"
962 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
965 mkPlan :: LStmt Name -> TcM PlanResult
966 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
967 = do { uniq <- newUnique -- is treated very specially
968 ; let fresh_it = itName uniq
969 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
970 matches = [mkMatch [] expr emptyLocalBinds]
971 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
972 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
973 (HsVar bindIOName) noSyntaxExpr
974 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
975 (HsVar thenIOName) placeHolderType
978 -- [it <- e; print it] but not if it::()
980 -- [let it = e; print it]
981 ; runPlans [ -- Plan A
982 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
983 ; it_ty <- zonkTcType (idType it_id)
984 ; ifM (isUnitTy it_ty) failM
987 -- Plan B; a naked bind statment
988 tcGhciStmts [bind_stmt],
990 -- Plan C; check that the let-binding is typeable all by itself.
991 -- If not, fail; if so, try to print it.
992 -- The two-step process avoids getting two errors: one from
993 -- the expression itself, and one from the 'print it' part
994 -- This two-step story is very clunky, alas
995 do { checkNoErrs (tcGhciStmts [let_stmt])
996 --- checkNoErrs defeats the error recovery of let-bindings
997 ; tcGhciStmts [let_stmt, print_it] }
1000 mkPlan stmt@(L loc (BindStmt {}))
1001 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1002 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1003 (HsVar thenIOName) placeHolderType
1005 ; print_bind_result <- doptM Opt_PrintBindResult
1006 ; let print_plan = do
1007 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1008 ; v_ty <- zonkTcType (idType v_id)
1009 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
1013 -- [stmt; print v] but not if v::()
1015 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1016 [tcGhciStmts [stmt]])
1020 = tcGhciStmts [stmt]
1022 ---------------------------
1023 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1025 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1026 ret_id <- tcLookupId returnIOName ; -- return @ IO
1028 io_ty = mkTyConApp ioTyCon [] ;
1029 ret_ty = mkListTy unitTy ;
1030 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1031 tc_io_stmts stmts = tcStmts DoExpr (tcDoStmt io_ty) stmts
1032 (emptyRefinement, io_ret_ty) ;
1034 names = map unLoc (collectLStmtsBinders stmts) ;
1036 -- mk_return builds the expression
1037 -- returnIO @ [()] [coerce () x, .., coerce () z]
1039 -- Despite the inconvenience of building the type applications etc,
1040 -- this *has* to be done in type-annotated post-typecheck form
1041 -- because we are going to return a list of *polymorphic* values
1042 -- coerced to type (). If we built a *source* stmt
1043 -- return [coerce x, ..., coerce z]
1044 -- then the type checker would instantiate x..z, and we wouldn't
1045 -- get their *polymorphic* values. (And we'd get ambiguity errs
1046 -- if they were overloaded, since they aren't applied to anything.)
1047 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1048 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1049 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1053 -- OK, we're ready to typecheck the stmts
1054 traceTc (text "tcs 2") ;
1055 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1056 mappM tcLookupId names ;
1057 -- Look up the names right in the middle,
1058 -- where they will all be in scope
1060 -- Simplify the context
1061 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1062 -- checkNoErrs ensures that the plan fails if context redn fails
1064 return (ids, mkHsDictLet const_binds $
1065 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1070 tcRnExpr just finds the type of an expression
1074 -> InteractiveContext
1077 tcRnExpr hsc_env ictxt rdr_expr
1078 = initTcPrintErrors hsc_env iNTERACTIVE $
1079 setInteractiveContext hsc_env ictxt $ do {
1081 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1084 -- Now typecheck the expression;
1085 -- it might have a rank-2 type (e.g. :t runST)
1086 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1087 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1088 tcSimplifyInteractive lie_top ;
1090 let { all_expr_ty = mkForAllTys qtvs $
1091 mkFunTys (map (idType . instToId) dict_insts) $
1093 zonkTcType all_expr_ty
1096 smpl_doc = ptext SLIT("main expression")
1099 tcRnType just finds the kind of a type
1103 -> InteractiveContext
1106 tcRnType hsc_env ictxt rdr_type
1107 = initTcPrintErrors hsc_env iNTERACTIVE $
1108 setInteractiveContext hsc_env ictxt $ do {
1110 rn_type <- rnLHsType doc rdr_type ;
1113 -- Now kind-check the type
1114 (ty', kind) <- kcHsType rn_type ;
1118 doc = ptext SLIT("In GHCi input")
1124 %************************************************************************
1126 More GHCi stuff, to do with browsing and getting info
1128 %************************************************************************
1132 -- ASSUMES that the module is either in the HomePackageTable or is
1133 -- a package module with an interface on disk. If neither of these is
1134 -- true, then the result will be an error indicating the interface
1135 -- could not be found.
1136 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1137 getModuleExports hsc_env mod
1140 checkMods = ic_toplev_scope ic ++ ic_exports ic
1142 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1144 -- Get the export avail info and also load all orphan and family-instance
1145 -- modules. Finally, check that the family instances of all modules in the
1146 -- interactive context are consistent (these modules are in the second
1148 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1149 tcGetModuleExports mod directlyImpMods
1150 = do { let doc = ptext SLIT("context for compiling statements")
1151 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1153 -- Load any orphan-module and family instance-module
1154 -- interfaces, so their instances are visible.
1155 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1156 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1158 -- Check that the family instances of all directly loaded
1159 -- modules are consistent.
1160 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1162 ; ifaceExportNames (mi_exports iface)
1165 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1166 tcRnLookupRdrName hsc_env rdr_name
1167 = initTcPrintErrors hsc_env iNTERACTIVE $
1168 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1169 lookup_rdr_name rdr_name
1171 lookup_rdr_name rdr_name = do {
1172 -- If the identifier is a constructor (begins with an
1173 -- upper-case letter), then we need to consider both
1174 -- constructor and type class identifiers.
1175 let { rdr_names = dataTcOccs rdr_name } ;
1177 -- results :: [Either Messages Name]
1178 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1180 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1181 -- The successful lookups will be (Just name)
1182 let { (warns_s, good_names) = unzip [ (msgs, name)
1183 | (msgs, Just name) <- results] ;
1184 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1186 -- Fail if nothing good happened, else add warnings
1187 if null good_names then
1188 -- No lookup succeeded, so
1189 -- pick the first error message and report it
1190 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1191 -- while the other is "X is not in scope",
1192 -- we definitely want the former; but we might pick the latter
1193 do { addMessages (head errs_s) ; failM }
1194 else -- Add deprecation warnings
1195 mapM_ addMessages warns_s ;
1200 tcRnRecoverDataCon :: HscEnv -> Ptr () -> IO (Maybe DataCon)
1201 tcRnRecoverDataCon hsc_env ptr
1202 = initTcPrintErrors hsc_env iNTERACTIVE $
1203 setInteractiveContext hsc_env (hsc_IC hsc_env) $ do
1204 name <- dataConInfoPtrToName ptr
1205 tcLookupDataCon name
1207 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1208 tcRnLookupName hsc_env name
1209 = initTcPrintErrors hsc_env iNTERACTIVE $
1210 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1211 tcRnLookupName' name
1213 -- To look up a name we have to look in the local environment (tcl_lcl)
1214 -- as well as the global environment, which is what tcLookup does.
1215 -- But we also want a TyThing, so we have to convert:
1217 tcRnLookupName' :: Name -> TcRn TyThing
1218 tcRnLookupName' name = do
1219 tcthing <- tcLookup name
1221 AGlobal thing -> return thing
1222 ATcId{tct_id=id} -> return (AnId id)
1223 _ -> panic "tcRnLookupName'"
1225 tcRnGetInfo :: HscEnv
1227 -> IO (Maybe (TyThing, Fixity, [Instance]))
1229 -- Used to implemnent :info in GHCi
1231 -- Look up a RdrName and return all the TyThings it might be
1232 -- A capitalised RdrName is given to us in the DataName namespace,
1233 -- but we want to treat it as *both* a data constructor
1234 -- *and* as a type or class constructor;
1235 -- hence the call to dataTcOccs, and we return up to two results
1236 tcRnGetInfo hsc_env name
1237 = initTcPrintErrors hsc_env iNTERACTIVE $
1238 let ictxt = hsc_IC hsc_env in
1239 setInteractiveContext hsc_env ictxt $ do
1241 -- Load the interface for all unqualified types and classes
1242 -- That way we will find all the instance declarations
1243 -- (Packages have not orphan modules, and we assume that
1244 -- in the home package all relevant modules are loaded.)
1245 loadUnqualIfaces ictxt
1247 thing <- tcRnLookupName' name
1248 fixity <- lookupFixityRn name
1249 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1250 return (thing, fixity, ispecs)
1252 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1253 -- Filter the instances by the ones whose tycons (or clases resp)
1254 -- are in scope unqualified. Otherwise we list a whole lot too many!
1255 lookupInsts print_unqual (AClass cls)
1256 = do { inst_envs <- tcGetInstEnvs
1258 | ispec <- classInstances inst_envs cls
1259 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1261 lookupInsts print_unqual (ATyCon tc)
1262 = do { eps <- getEps -- Load all instances for all classes that are
1263 -- in the type environment (which are all the ones
1264 -- we've seen in any interface file so far)
1265 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1267 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1268 , let dfun = instanceDFunId ispec
1270 , plausibleDFun print_unqual dfun ] }
1272 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1273 tc_name = tyConName tc
1275 lookupInsts print_unqual other = return []
1277 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1278 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1280 ok name | isBuiltInSyntax name = True
1281 | isExternalName name =
1282 isNothing $ fst print_unqual (nameModule name)
1286 loadUnqualIfaces :: InteractiveContext -> TcM ()
1287 -- Load the home module for everything that is in scope unqualified
1288 -- This is so that we can accurately report the instances for
1290 loadUnqualIfaces ictxt
1292 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1294 unqual_mods = [ nameModule name
1295 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1296 let name = gre_name gre,
1297 not (isInternalName name),
1298 isTcOcc (nameOccName name), -- Types and classes only
1299 unQualOK gre ] -- In scope unqualified
1300 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1304 %************************************************************************
1308 %************************************************************************
1311 rnDump :: SDoc -> TcRn ()
1312 -- Dump, with a banner, if -ddump-rn
1313 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1315 tcDump :: TcGblEnv -> TcRn ()
1317 = do { dflags <- getDOpts ;
1319 -- Dump short output if -ddump-types or -ddump-tc
1320 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1321 (dumpTcRn short_dump) ;
1323 -- Dump bindings if -ddump-tc
1324 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1327 short_dump = pprTcGblEnv env
1328 full_dump = pprLHsBinds (tcg_binds env)
1329 -- NB: foreign x-d's have undefined's in their types;
1330 -- hence can't show the tc_fords
1333 = do { dflags <- getDOpts ;
1334 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1335 (dumpTcRn (pprModGuts mod_guts)) ;
1337 -- Dump bindings if -ddump-tc
1338 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1340 full_dump = pprCoreBindings (mg_binds mod_guts)
1342 -- It's unpleasant having both pprModGuts and pprModDetails here
1343 pprTcGblEnv :: TcGblEnv -> SDoc
1344 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1346 tcg_fam_insts = fam_insts,
1348 tcg_imports = imports })
1349 = vcat [ ppr_types insts type_env
1350 , ppr_tycons fam_insts type_env
1352 , ppr_fam_insts fam_insts
1353 , vcat (map ppr rules)
1354 , ppr_gen_tycons (typeEnvTyCons type_env)
1355 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1356 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1358 pprModGuts :: ModGuts -> SDoc
1359 pprModGuts (ModGuts { mg_types = type_env,
1361 = vcat [ ppr_types [] type_env,
1364 ppr_types :: [Instance] -> TypeEnv -> SDoc
1365 ppr_types insts type_env
1366 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1368 dfun_ids = map instanceDFunId insts
1369 ids = [id | id <- typeEnvIds type_env, want_sig id]
1370 want_sig id | opt_PprStyle_Debug = True
1371 | otherwise = isLocalId id &&
1372 isExternalName (idName id) &&
1373 not (id `elem` dfun_ids)
1374 -- isLocalId ignores data constructors, records selectors etc.
1375 -- The isExternalName ignores local dictionary and method bindings
1376 -- that the type checker has invented. Top-level user-defined things
1377 -- have External names.
1379 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1380 ppr_tycons fam_insts type_env
1381 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1383 fi_tycons = map famInstTyCon fam_insts
1384 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1385 want_tycon tycon | opt_PprStyle_Debug = True
1386 | otherwise = not (isImplicitTyCon tycon) &&
1387 isExternalName (tyConName tycon) &&
1388 not (tycon `elem` fi_tycons)
1390 ppr_insts :: [Instance] -> SDoc
1391 ppr_insts [] = empty
1392 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1394 ppr_fam_insts :: [FamInst] -> SDoc
1395 ppr_fam_insts [] = empty
1396 ppr_fam_insts fam_insts =
1397 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1399 ppr_sigs :: [Var] -> SDoc
1401 -- Print type signatures; sort by OccName
1402 = vcat (map ppr_sig (sortLe le_sig ids))
1404 le_sig id1 id2 = getOccName id1 <= getOccName id2
1405 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1407 ppr_tydecls :: [TyCon] -> SDoc
1409 -- Print type constructor info; sort by OccName
1410 = vcat (map ppr_tycon (sortLe le_sig tycons))
1412 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1414 | isCoercionTyCon tycon = ptext SLIT("coercion") <+> ppr tycon
1415 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1417 ppr_rules :: [CoreRule] -> SDoc
1418 ppr_rules [] = empty
1419 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1420 nest 4 (pprRules rs),
1423 ppr_gen_tycons [] = empty
1424 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1425 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]