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 (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 -- later ids in ic_tmp_ids must shadow earlier ones with the same
844 -- OccName, and tcExtendIdEnv implements this behaviour.
846 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
853 -> InteractiveContext
855 -> IO (Maybe ([Id], LHsExpr Id))
856 -- The returned [Id] is the list of new Ids bound by
857 -- this statement. It can be used to extend the
858 -- InteractiveContext via extendInteractiveContext.
860 -- The returned TypecheckedHsExpr is of type IO [ () ],
861 -- a list of the bound values, coerced to ().
863 tcRnStmt hsc_env ictxt rdr_stmt
864 = initTcPrintErrors hsc_env iNTERACTIVE $
865 setInteractiveContext hsc_env ictxt $ do {
867 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
868 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
869 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
872 -- The real work is done here
873 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
874 zonked_expr <- zonkTopLExpr tc_expr ;
875 zonked_ids <- zonkTopBndrs bound_ids ;
877 -- None of the Ids should be of unboxed type, because we
878 -- cast them all to HValues in the end!
879 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
881 traceTc (text "tcs 1") ;
882 let { -- (a) Make all the bound ids "global" ids, now that
883 -- they're notionally top-level bindings. This is
884 -- important: otherwise when we come to compile an expression
885 -- using these ids later, the byte code generator will consider
886 -- the occurrences to be free rather than global.
888 -- (b) Tidy their types; this is important, because :info may
889 -- ask to look at them, and :info expects the things it looks
890 -- up to have tidy types
891 global_ids = map globaliseAndTidy zonked_ids ;
893 {- ---------------------------------------------
894 At one stage I removed any shadowed bindings from the type_env;
895 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
896 However, with Template Haskell they aren't necessarily inaccessible. Consider this
898 Prelude> let f n = n * 2 :: Int
899 Prelude> fName <- runQ [| f |]
900 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
902 Prelude> let f n = n * 3 :: Int
903 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
904 In the last line we use 'fName', which resolves to the *first* 'f'
905 in scope. If we delete it from the type env, GHCi crashes because
906 it doesn't expect that.
908 Hence this code is commented out
910 -------------------------------------------------- -}
913 dumpOptTcRn Opt_D_dump_tc
914 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
915 text "Typechecked expr" <+> ppr zonked_expr]) ;
917 returnM (global_ids, zonked_expr)
920 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
921 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
923 globaliseAndTidy :: Id -> Id
925 -- Give the Id a Global Name, and tidy its type
926 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
928 tidy_type = tidyTopType (idType id)
931 Here is the grand plan, implemented in tcUserStmt
933 What you type The IO [HValue] that hscStmt returns
934 ------------- ------------------------------------
935 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
938 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
941 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
942 [NB: result not printed] bindings: [it]
944 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
945 result showable) bindings: [it]
947 expr (of non-IO type,
948 result not showable) ==> error
952 ---------------------------
953 type PlanResult = ([Id], LHsExpr Id)
954 type Plan = TcM PlanResult
956 runPlans :: [Plan] -> TcM PlanResult
957 -- Try the plans in order. If one fails (by raising an exn), try the next.
958 -- If one succeeds, take it.
959 runPlans [] = panic "runPlans"
961 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
964 mkPlan :: LStmt Name -> TcM PlanResult
965 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
966 = do { uniq <- newUnique -- is treated very specially
967 ; let fresh_it = itName uniq
968 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
969 matches = [mkMatch [] expr emptyLocalBinds]
970 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
971 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
972 (HsVar bindIOName) noSyntaxExpr
973 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
974 (HsVar thenIOName) placeHolderType
977 -- [it <- e; print it] but not if it::()
979 -- [let it = e; print it]
980 ; runPlans [ -- Plan A
981 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
982 ; it_ty <- zonkTcType (idType it_id)
983 ; ifM (isUnitTy it_ty) failM
986 -- Plan B; a naked bind statment
987 tcGhciStmts [bind_stmt],
989 -- Plan C; check that the let-binding is typeable all by itself.
990 -- If not, fail; if so, try to print it.
991 -- The two-step process avoids getting two errors: one from
992 -- the expression itself, and one from the 'print it' part
993 -- This two-step story is very clunky, alas
994 do { checkNoErrs (tcGhciStmts [let_stmt])
995 --- checkNoErrs defeats the error recovery of let-bindings
996 ; tcGhciStmts [let_stmt, print_it] }
999 mkPlan stmt@(L loc (BindStmt {}))
1000 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1001 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1002 (HsVar thenIOName) placeHolderType
1004 ; print_bind_result <- doptM Opt_PrintBindResult
1005 ; let print_plan = do
1006 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1007 ; v_ty <- zonkTcType (idType v_id)
1008 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
1012 -- [stmt; print v] but not if v::()
1014 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1015 [tcGhciStmts [stmt]])
1019 = tcGhciStmts [stmt]
1021 ---------------------------
1022 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1024 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1025 ret_id <- tcLookupId returnIOName ; -- return @ IO
1027 io_ty = mkTyConApp ioTyCon [] ;
1028 ret_ty = mkListTy unitTy ;
1029 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1030 tc_io_stmts stmts = tcStmts DoExpr (tcDoStmt io_ty) stmts
1031 (emptyRefinement, io_ret_ty) ;
1033 names = map unLoc (collectLStmtsBinders stmts) ;
1035 -- mk_return builds the expression
1036 -- returnIO @ [()] [coerce () x, .., coerce () z]
1038 -- Despite the inconvenience of building the type applications etc,
1039 -- this *has* to be done in type-annotated post-typecheck form
1040 -- because we are going to return a list of *polymorphic* values
1041 -- coerced to type (). If we built a *source* stmt
1042 -- return [coerce x, ..., coerce z]
1043 -- then the type checker would instantiate x..z, and we wouldn't
1044 -- get their *polymorphic* values. (And we'd get ambiguity errs
1045 -- if they were overloaded, since they aren't applied to anything.)
1046 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1047 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1048 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1052 -- OK, we're ready to typecheck the stmts
1053 traceTc (text "tcs 2") ;
1054 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1055 mappM tcLookupId names ;
1056 -- Look up the names right in the middle,
1057 -- where they will all be in scope
1059 -- Simplify the context
1060 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1061 -- checkNoErrs ensures that the plan fails if context redn fails
1063 return (ids, mkHsDictLet const_binds $
1064 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1069 tcRnExpr just finds the type of an expression
1073 -> InteractiveContext
1076 tcRnExpr hsc_env ictxt rdr_expr
1077 = initTcPrintErrors hsc_env iNTERACTIVE $
1078 setInteractiveContext hsc_env ictxt $ do {
1080 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1083 -- Now typecheck the expression;
1084 -- it might have a rank-2 type (e.g. :t runST)
1085 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1086 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1087 tcSimplifyInteractive lie_top ;
1089 let { all_expr_ty = mkForAllTys qtvs $
1090 mkFunTys (map (idType . instToId) dict_insts) $
1092 zonkTcType all_expr_ty
1095 smpl_doc = ptext SLIT("main expression")
1098 tcRnType just finds the kind of a type
1102 -> InteractiveContext
1105 tcRnType hsc_env ictxt rdr_type
1106 = initTcPrintErrors hsc_env iNTERACTIVE $
1107 setInteractiveContext hsc_env ictxt $ do {
1109 rn_type <- rnLHsType doc rdr_type ;
1112 -- Now kind-check the type
1113 (ty', kind) <- kcHsType rn_type ;
1117 doc = ptext SLIT("In GHCi input")
1123 %************************************************************************
1125 More GHCi stuff, to do with browsing and getting info
1127 %************************************************************************
1131 -- ASSUMES that the module is either in the HomePackageTable or is
1132 -- a package module with an interface on disk. If neither of these is
1133 -- true, then the result will be an error indicating the interface
1134 -- could not be found.
1135 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1136 getModuleExports hsc_env mod
1139 checkMods = ic_toplev_scope ic ++ ic_exports ic
1141 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1143 -- Get the export avail info and also load all orphan and family-instance
1144 -- modules. Finally, check that the family instances of all modules in the
1145 -- interactive context are consistent (these modules are in the second
1147 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1148 tcGetModuleExports mod directlyImpMods
1149 = do { let doc = ptext SLIT("context for compiling statements")
1150 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1152 -- Load any orphan-module and family instance-module
1153 -- interfaces, so their instances are visible.
1154 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1155 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1157 -- Check that the family instances of all directly loaded
1158 -- modules are consistent.
1159 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1161 ; ifaceExportNames (mi_exports iface)
1164 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1165 tcRnLookupRdrName hsc_env rdr_name
1166 = initTcPrintErrors hsc_env iNTERACTIVE $
1167 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1168 lookup_rdr_name rdr_name
1170 lookup_rdr_name rdr_name = do {
1171 -- If the identifier is a constructor (begins with an
1172 -- upper-case letter), then we need to consider both
1173 -- constructor and type class identifiers.
1174 let { rdr_names = dataTcOccs rdr_name } ;
1176 -- results :: [Either Messages Name]
1177 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1179 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1180 -- The successful lookups will be (Just name)
1181 let { (warns_s, good_names) = unzip [ (msgs, name)
1182 | (msgs, Just name) <- results] ;
1183 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1185 -- Fail if nothing good happened, else add warnings
1186 if null good_names then
1187 -- No lookup succeeded, so
1188 -- pick the first error message and report it
1189 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1190 -- while the other is "X is not in scope",
1191 -- we definitely want the former; but we might pick the latter
1192 do { addMessages (head errs_s) ; failM }
1193 else -- Add deprecation warnings
1194 mapM_ addMessages warns_s ;
1199 tcRnRecoverDataCon :: HscEnv -> Ptr () -> IO (Maybe DataCon)
1200 tcRnRecoverDataCon hsc_env ptr
1201 = initTcPrintErrors hsc_env iNTERACTIVE $
1202 setInteractiveContext hsc_env (hsc_IC hsc_env) $ do
1203 name <- dataConInfoPtrToName ptr
1204 tcLookupDataCon name
1206 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1207 tcRnLookupName hsc_env name
1208 = initTcPrintErrors hsc_env iNTERACTIVE $
1209 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1210 tcRnLookupName' name
1212 -- To look up a name we have to look in the local environment (tcl_lcl)
1213 -- as well as the global environment, which is what tcLookup does.
1214 -- But we also want a TyThing, so we have to convert:
1216 tcRnLookupName' :: Name -> TcRn TyThing
1217 tcRnLookupName' name = do
1218 tcthing <- tcLookup name
1220 AGlobal thing -> return thing
1221 ATcId{tct_id=id} -> return (AnId id)
1222 _ -> panic "tcRnLookupName'"
1224 tcRnGetInfo :: HscEnv
1226 -> IO (Maybe (TyThing, Fixity, [Instance]))
1228 -- Used to implemnent :info in GHCi
1230 -- Look up a RdrName and return all the TyThings it might be
1231 -- A capitalised RdrName is given to us in the DataName namespace,
1232 -- but we want to treat it as *both* a data constructor
1233 -- *and* as a type or class constructor;
1234 -- hence the call to dataTcOccs, and we return up to two results
1235 tcRnGetInfo hsc_env name
1236 = initTcPrintErrors hsc_env iNTERACTIVE $
1237 let ictxt = hsc_IC hsc_env in
1238 setInteractiveContext hsc_env ictxt $ do
1240 -- Load the interface for all unqualified types and classes
1241 -- That way we will find all the instance declarations
1242 -- (Packages have not orphan modules, and we assume that
1243 -- in the home package all relevant modules are loaded.)
1244 loadUnqualIfaces ictxt
1246 thing <- tcRnLookupName' name
1247 fixity <- lookupFixityRn name
1248 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1249 return (thing, fixity, ispecs)
1251 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1252 -- Filter the instances by the ones whose tycons (or clases resp)
1253 -- are in scope unqualified. Otherwise we list a whole lot too many!
1254 lookupInsts print_unqual (AClass cls)
1255 = do { inst_envs <- tcGetInstEnvs
1257 | ispec <- classInstances inst_envs cls
1258 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1260 lookupInsts print_unqual (ATyCon tc)
1261 = do { eps <- getEps -- Load all instances for all classes that are
1262 -- in the type environment (which are all the ones
1263 -- we've seen in any interface file so far)
1264 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1266 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1267 , let dfun = instanceDFunId ispec
1269 , plausibleDFun print_unqual dfun ] }
1271 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1272 tc_name = tyConName tc
1274 lookupInsts print_unqual other = return []
1276 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1277 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1279 ok name | isBuiltInSyntax name = True
1280 | isExternalName name =
1281 isNothing $ fst print_unqual (nameModule name)
1285 loadUnqualIfaces :: InteractiveContext -> TcM ()
1286 -- Load the home module for everything that is in scope unqualified
1287 -- This is so that we can accurately report the instances for
1289 loadUnqualIfaces ictxt
1291 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1293 unqual_mods = [ nameModule name
1294 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1295 let name = gre_name gre,
1296 not (isInternalName name),
1297 isTcOcc (nameOccName name), -- Types and classes only
1298 unQualOK gre ] -- In scope unqualified
1299 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1303 %************************************************************************
1307 %************************************************************************
1310 rnDump :: SDoc -> TcRn ()
1311 -- Dump, with a banner, if -ddump-rn
1312 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1314 tcDump :: TcGblEnv -> TcRn ()
1316 = do { dflags <- getDOpts ;
1318 -- Dump short output if -ddump-types or -ddump-tc
1319 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1320 (dumpTcRn short_dump) ;
1322 -- Dump bindings if -ddump-tc
1323 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1326 short_dump = pprTcGblEnv env
1327 full_dump = pprLHsBinds (tcg_binds env)
1328 -- NB: foreign x-d's have undefined's in their types;
1329 -- hence can't show the tc_fords
1332 = do { dflags <- getDOpts ;
1333 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1334 (dumpTcRn (pprModGuts mod_guts)) ;
1336 -- Dump bindings if -ddump-tc
1337 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1339 full_dump = pprCoreBindings (mg_binds mod_guts)
1341 -- It's unpleasant having both pprModGuts and pprModDetails here
1342 pprTcGblEnv :: TcGblEnv -> SDoc
1343 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1345 tcg_fam_insts = fam_insts,
1347 tcg_imports = imports })
1348 = vcat [ ppr_types insts type_env
1349 , ppr_tycons fam_insts type_env
1351 , ppr_fam_insts fam_insts
1352 , vcat (map ppr rules)
1353 , ppr_gen_tycons (typeEnvTyCons type_env)
1354 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1355 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1357 pprModGuts :: ModGuts -> SDoc
1358 pprModGuts (ModGuts { mg_types = type_env,
1360 = vcat [ ppr_types [] type_env,
1363 ppr_types :: [Instance] -> TypeEnv -> SDoc
1364 ppr_types insts type_env
1365 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1367 dfun_ids = map instanceDFunId insts
1368 ids = [id | id <- typeEnvIds type_env, want_sig id]
1369 want_sig id | opt_PprStyle_Debug = True
1370 | otherwise = isLocalId id &&
1371 isExternalName (idName id) &&
1372 not (id `elem` dfun_ids)
1373 -- isLocalId ignores data constructors, records selectors etc.
1374 -- The isExternalName ignores local dictionary and method bindings
1375 -- that the type checker has invented. Top-level user-defined things
1376 -- have External names.
1378 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1379 ppr_tycons fam_insts type_env
1380 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1382 fi_tycons = map famInstTyCon fam_insts
1383 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1384 want_tycon tycon | opt_PprStyle_Debug = True
1385 | otherwise = not (isImplicitTyCon tycon) &&
1386 isExternalName (tyConName tycon) &&
1387 not (tycon `elem` fi_tycons)
1389 ppr_insts :: [Instance] -> SDoc
1390 ppr_insts [] = empty
1391 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1393 ppr_fam_insts :: [FamInst] -> SDoc
1394 ppr_fam_insts [] = empty
1395 ppr_fam_insts fam_insts =
1396 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1398 ppr_sigs :: [Var] -> SDoc
1400 -- Print type signatures; sort by OccName
1401 = vcat (map ppr_sig (sortLe le_sig ids))
1403 le_sig id1 id2 = getOccName id1 <= getOccName id2
1404 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1406 ppr_tydecls :: [TyCon] -> SDoc
1408 -- Print type constructor info; sort by OccName
1409 = vcat (map ppr_tycon (sortLe le_sig tycons))
1411 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1413 | isCoercionTyCon tycon = ptext SLIT("coercion") <+> ppr tycon
1414 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1416 ppr_rules :: [CoreRule] -> SDoc
1417 ppr_rules [] = empty
1418 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1419 nest 4 (pprRules rs),
1422 ppr_gen_tycons [] = empty
1423 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1424 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]