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 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
50 import TcUnify ( withBox )
76 import Data.List ( sortBy )
87 import TidyPgm ( globaliseAndTidyId )
88 import TysWiredIn ( unitTy, mkListTy )
98 #include "HsVersions.h"
101 %************************************************************************
103 Typecheck and rename a module
105 %************************************************************************
111 -> Bool -- True <=> save renamed syntax
112 -> Located (HsModule RdrName)
113 -> IO (Messages, Maybe TcGblEnv)
115 tcRnModule hsc_env hsc_src save_rn_syntax
116 (L loc (HsModule maybe_mod export_ies
117 import_decls local_decls mod_deprec
119 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
121 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
122 this_mod = case maybe_mod of
123 Nothing -> mAIN -- 'module M where' is omitted
124 Just (L _ mod) -> mkModule this_pkg mod } ;
127 initTc hsc_env hsc_src save_rn_syntax this_mod $
129 do { -- Deal with imports;
130 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
131 setGblEnv tcg_env $ do {
133 -- Load the hi-boot interface for this module, if any
134 -- We do this now so that the boot_names can be passed
135 -- to tcTyAndClassDecls, because the boot_names are
136 -- automatically considered to be loop breakers
138 -- Do this *after* tcRnImports, so that we know whether
139 -- a module that we import imports us; and hence whether to
140 -- look for a hi-boot file
141 boot_iface <- tcHiBootIface hsc_src this_mod ;
143 -- Rename and type check the declarations
144 traceRn (text "rn1a") ;
145 tcg_env <- if isHsBoot hsc_src then
146 tcRnHsBootDecls local_decls
148 tcRnSrcDecls boot_iface local_decls ;
149 setGblEnv tcg_env $ do {
151 -- Report the use of any deprecated things
152 -- We do this *before* processsing the export list so
153 -- that we don't bleat about re-exporting a deprecated
154 -- thing (especially via 'module Foo' export item)
155 -- That is, only uses in the *body* of the module are complained about
156 traceRn (text "rn3") ;
157 failIfErrsM ; -- finishWarnings crashes sometimes
158 -- as a result of typechecker repairs (e.g. unboundNames)
159 tcg_env <- finishWarnings (hsc_dflags hsc_env) mod_deprec tcg_env ;
161 -- Process the export list
162 traceRn (text "rn4a: before exports");
163 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
164 traceRn (text "rn4b: after exportss") ;
166 -- Check that main is exported (must be after rnExports)
167 checkMainExported tcg_env ;
169 -- Compare the hi-boot iface (if any) with the real thing
170 -- Must be done after processing the exports
171 tcg_env <- checkHiBootIface tcg_env boot_iface ;
173 -- The new type env is already available to stuff slurped from
174 -- interface files, via TcEnv.updateGlobalTypeEnv
175 -- It's important that this includes the stuff in checkHiBootIface,
176 -- because the latter might add new bindings for boot_dfuns,
177 -- which may be mentioned in imported unfoldings
179 -- Don't need to rename the Haddock documentation,
180 -- it's not parsed by GHC anymore.
181 tcg_env <- return (tcg_env { tcg_doc_hdr = maybe_doc_hdr }) ;
183 -- Report unused names
184 reportUnusedNames export_ies tcg_env ;
186 -- Dump output and return
193 %************************************************************************
197 %************************************************************************
200 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
201 tcRnImports hsc_env this_mod import_decls
202 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
204 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
205 ; dep_mods = imp_dep_mods imports
207 -- We want instance declarations from all home-package
208 -- modules below this one, including boot modules, except
209 -- ourselves. The 'except ourselves' is so that we don't
210 -- get the instances from this module's hs-boot file
211 ; want_instances :: ModuleName -> Bool
212 ; want_instances mod = mod `elemUFM` dep_mods
213 && mod /= moduleName this_mod
214 ; (home_insts, home_fam_insts) = hptInstances hsc_env
218 -- Record boot-file info in the EPS, so that it's
219 -- visible to loadHiBootInterface in tcRnSrcDecls,
220 -- and any other incrementally-performed imports
221 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
223 -- Update the gbl env
224 ; updGblEnv ( \ gbl ->
226 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
227 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
228 tcg_rn_imports = rn_imports,
229 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
230 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
235 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
236 -- Fail if there are any errors so far
237 -- The error printing (if needed) takes advantage
238 -- of the tcg_env we have now set
239 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
242 -- Load any orphan-module and family instance-module
243 -- interfaces, so that their rules and instance decls will be
245 ; loadOrphanModules (imp_orphs imports) False
246 ; loadOrphanModules (imp_finsts imports) True
248 -- Check type-familily consistency
249 ; traceRn (text "rn1: checking family instance consistency")
250 ; let { dir_imp_mods = moduleEnvKeys
253 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
259 %************************************************************************
261 Type-checking external-core modules
263 %************************************************************************
266 tcRnExtCore :: HscEnv
268 -> IO (Messages, Maybe ModGuts)
269 -- Nothing => some error occurred
271 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
272 -- The decls are IfaceDecls; all names are original names
273 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
275 initTc hsc_env ExtCoreFile False this_mod $ do {
277 let { ldecls = map noLoc decls } ;
279 -- bring the type and class decls into scope
280 -- ToDo: check that this doesn't need to extract the val binds.
281 -- It seems that only the type and class decls need to be in scope below because
282 -- (a) tcTyAndClassDecls doesn't need the val binds, and
283 -- (b) tcExtCoreBindings doesn't need anything
284 -- (in fact, it might not even need to be in the scope of
285 -- this tcg_env at all)
286 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
287 tc_envs <- extendGlobalRdrEnvRn avails emptyFsEnv {- no fixity decls -} ;
289 setEnvs tc_envs $ do {
291 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
293 -- Dump trace of renaming part
294 rnDump (ppr rn_decls) ;
296 -- Typecheck them all together so that
297 -- any mutually recursive types are done right
298 -- Just discard the auxiliary bindings; they are generated
299 -- only for Haskell source code, and should already be in Core
300 (tcg_env, _aux_binds, _dm_ids) <- tcTyAndClassDecls emptyModDetails rn_decls ;
302 setGblEnv tcg_env $ do {
303 -- Make the new type env available to stuff slurped from interface files
305 -- Now the core bindings
306 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
310 bndrs = bindersOfBinds core_binds ;
311 my_exports = map (Avail . idName) bndrs ;
312 -- ToDo: export the data types also?
315 extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
317 mod_guts = ModGuts { mg_module = this_mod,
319 mg_used_names = emptyNameSet, -- ToDo: compute usage
320 mg_dir_imps = emptyModuleEnv, -- ??
321 mg_deps = noDependencies, -- ??
322 mg_exports = my_exports,
323 mg_types = final_type_env,
324 mg_insts = tcg_insts tcg_env,
325 mg_fam_insts = tcg_fam_insts tcg_env,
326 mg_inst_env = tcg_inst_env tcg_env,
327 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
330 mg_binds = core_binds,
333 mg_rdr_env = emptyGlobalRdrEnv,
334 mg_fix_env = emptyFixityEnv,
335 mg_warns = NoWarnings,
336 mg_foreign = NoStubs,
337 mg_hpc_info = emptyHpcInfo False,
338 mg_modBreaks = emptyModBreaks,
339 mg_vect_info = noVectInfo
342 tcCoreDump mod_guts ;
347 mkFakeGroup :: [LTyClDecl a] -> HsGroup a
348 mkFakeGroup decls -- Rather clumsy; lots of unused fields
349 = emptyRdrGroup { hs_tyclds = decls }
353 %************************************************************************
355 Type-checking the top level of a module
357 %************************************************************************
360 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
361 -- Returns the variables free in the decls
362 -- Reason: solely to report unused imports and bindings
363 tcRnSrcDecls boot_iface decls
364 = do { -- Do all the declarations
365 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
367 -- Finish simplifying class constraints
369 -- tcSimplifyTop deals with constant or ambiguous InstIds.
370 -- How could there be ambiguous ones? They can only arise if a
371 -- top-level decl falls under the monomorphism restriction
372 -- and no subsequent decl instantiates its type.
374 -- We do this after checkMain, so that we use the type info
375 -- thaat checkMain adds
377 -- We do it with both global and local env in scope:
378 -- * the global env exposes the instances to tcSimplifyTop
379 -- * the local env exposes the local Ids to tcSimplifyTop,
380 -- so that we get better error messages (monomorphism restriction)
381 traceTc (text "Tc8") ;
382 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
384 -- Backsubstitution. This must be done last.
385 -- Even tcSimplifyTop may do some unification.
386 traceTc (text "Tc9") ;
387 let { (tcg_env, _) = tc_envs
388 ; TcGblEnv { tcg_type_env = type_env,
391 tcg_fords = fords } = tcg_env
392 ; all_binds = binds `unionBags` inst_binds } ;
394 failIfErrsM ; -- Don't zonk if there have been errors
395 -- It's a waste of time; and we may get debug warnings
396 -- about strangely-typed TyCons!
398 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
401 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
402 ; tcg_env' = tcg_env { tcg_binds = binds',
404 tcg_fords = fords' } } ;
406 setGlobalTypeEnv tcg_env' final_type_env
409 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
410 -- Loops around dealing with each top level inter-splice group
411 -- in turn, until it's dealt with the entire module
412 tc_rn_src_decls boot_details ds
413 = do { (first_group, group_tail) <- findSplice ds ;
414 -- If ds is [] we get ([], Nothing)
416 -- Deal with decls up to, but not including, the first splice
417 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
418 -- rnTopSrcDecls fails if there are any errors
420 (tcg_env, tcl_env) <- setGblEnv tcg_env $
421 tcTopSrcDecls boot_details rn_decls ;
423 -- If there is no splice, we're nearly done
424 setEnvs (tcg_env, tcl_env) $
426 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
427 return (tcg_env, tcl_env)
431 -- There shouldn't be a splice
432 Just (SpliceDecl {}, _) -> do {
433 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
435 -- If there's a splice, we must carry on
436 Just (SpliceDecl splice_expr _, rest_ds) -> do {
438 -- Rename the splice expression, and get its supporting decls
439 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
440 -- checkNoErrs: don't typecheck if renaming failed
441 rnDump (ppr rn_splice_expr) ;
443 -- Execute the splice
444 spliced_decls <- tcSpliceDecls rn_splice_expr ;
446 -- Glue them on the front of the remaining decls and loop
447 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
448 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
453 %************************************************************************
455 Compiling hs-boot source files, and
456 comparing the hi-boot interface with the real thing
458 %************************************************************************
461 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
462 tcRnHsBootDecls decls
463 = do { (first_group, group_tail) <- findSplice decls
465 -- Rename the declarations
466 ; (tcg_env, HsGroup {
467 hs_tyclds = tycl_decls,
468 hs_instds = inst_decls,
469 hs_derivds = deriv_decls,
470 hs_fords = for_decls,
471 hs_defds = def_decls,
472 hs_ruleds = rule_decls,
474 hs_valds = val_binds }) <- rnTopSrcDecls first_group
475 ; setGblEnv tcg_env $ do {
478 -- Check for illegal declarations
480 Just (SpliceDecl d _, _) -> badBootDecl "splice" d
482 ; mapM_ (badBootDecl "foreign") for_decls
483 ; mapM_ (badBootDecl "default") def_decls
484 ; mapM_ (badBootDecl "rule") rule_decls
486 -- Typecheck type/class decls
487 ; traceTc (text "Tc2")
488 ; (tcg_env, aux_binds, dm_ids)
489 <- tcTyAndClassDecls emptyModDetails tycl_decls
490 ; setGblEnv tcg_env $
491 tcExtendIdEnv dm_ids $ do {
493 -- Typecheck instance decls
494 -- Family instance declarations are rejected here
495 ; traceTc (text "Tc3")
496 ; (tcg_env, inst_infos, _deriv_binds)
497 <- tcInstDecls1 tycl_decls inst_decls deriv_decls
498 ; setGblEnv tcg_env $ do {
500 -- Typecheck value declarations
501 ; traceTc (text "Tc5")
502 ; val_ids <- tcHsBootSigs val_binds
505 -- No simplification or zonking to do
506 ; traceTc (text "Tc7a")
507 ; gbl_env <- getGblEnv
509 -- Make the final type-env
510 -- Include the dfun_ids so that their type sigs
511 -- are written into the interface file.
512 -- And similarly the aux_ids from aux_binds
513 ; let { type_env0 = tcg_type_env gbl_env
514 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
515 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
516 ; type_env3 = extendTypeEnvWithIds type_env2 aux_ids
517 ; dfun_ids = map iDFunId inst_infos
518 ; aux_ids = case aux_binds of
519 ValBindsOut _ sigs -> [id | L _ (IdSig id) <- sigs]
520 _ -> panic "tcRnHsBoodDecls"
523 ; setGlobalTypeEnv gbl_env type_env3
526 badBootDecl :: String -> Located decl -> TcM ()
527 badBootDecl what (L loc _)
528 = addErrAt loc (char 'A' <+> text what
529 <+> ptext (sLit "declaration is not (currently) allowed in a hs-boot file"))
532 Once we've typechecked the body of the module, we want to compare what
533 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
536 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
537 -- Compare the hi-boot file for this module (if there is one)
538 -- with the type environment we've just come up with
539 -- In the common case where there is no hi-boot file, the list
540 -- of boot_names is empty.
542 -- The bindings we return give bindings for the dfuns defined in the
543 -- hs-boot file, such as $fbEqT = $fEqT
546 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
547 tcg_insts = local_insts,
548 tcg_type_env = local_type_env, tcg_exports = local_exports })
549 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
550 md_types = boot_type_env, md_exports = boot_exports })
551 | isHsBoot hs_src -- Current module is already a hs-boot file!
555 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
558 -- Check the exports of the boot module, one by one
559 ; mapM_ check_export boot_exports
561 -- Check for no family instances
562 ; unless (null boot_fam_insts) $
563 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
564 "instances in boot files yet...")
565 -- FIXME: Why? The actual comparison is not hard, but what would
566 -- be the equivalent to the dfun bindings returned for class
567 -- instances? We can't easily equate tycons...
569 -- Check instance declarations
570 ; mb_dfun_prs <- mapM check_inst boot_insts
571 ; let dfun_prs = catMaybes mb_dfun_prs
572 boot_dfuns = map fst dfun_prs
573 dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun)
574 | (boot_dfun, dfun) <- dfun_prs ]
575 type_env' = extendTypeEnvWithIds local_type_env boot_dfuns
576 tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
579 ; setGlobalTypeEnv tcg_env' type_env' }
580 -- Update the global type env *including* the knot-tied one
581 -- so that if the source module reads in an interface unfolding
582 -- mentioning one of the dfuns from the boot module, then it
583 -- can "see" that boot dfun. See Trac #4003
585 check_export boot_avail -- boot_avail is exported by the boot iface
586 | name `elem` dfun_names = return ()
587 | isWiredInName name = return () -- No checking for wired-in names. In particular,
588 -- 'error' is handled by a rather gross hack
589 -- (see comments in GHC.Err.hs-boot)
591 -- Check that the actual module exports the same thing
592 | not (null missing_names)
593 = addErrAt (nameSrcSpan (head missing_names))
594 (missingBootThing (head missing_names) "exported by")
596 -- If the boot module does not *define* the thing, we are done
597 -- (it simply re-exports it, and names match, so nothing further to do)
598 | isNothing mb_boot_thing = return ()
600 -- Check that the actual module also defines the thing, and
601 -- then compare the definitions
602 | Just real_thing <- lookupTypeEnv local_type_env name,
603 Just boot_thing <- mb_boot_thing
604 = when (not (checkBootDecl boot_thing real_thing))
605 $ addErrAt (nameSrcSpan (getName boot_thing))
606 (let boot_decl = tyThingToIfaceDecl
607 (fromJust mb_boot_thing)
608 real_decl = tyThingToIfaceDecl real_thing
609 in bootMisMatch real_thing boot_decl real_decl)
612 = addErrTc (missingBootThing name "defined in")
614 name = availName boot_avail
615 mb_boot_thing = lookupTypeEnv boot_type_env name
616 missing_names = case lookupNameEnv local_export_env name of
618 Just avail -> availNames boot_avail `minusList` availNames avail
620 dfun_names = map getName boot_insts
622 local_export_env :: NameEnv AvailInfo
623 local_export_env = availsToNameEnv local_exports
625 check_inst :: Instance -> TcM (Maybe (Id, Id))
626 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
628 = case [dfun | inst <- local_insts,
629 let dfun = instanceDFunId inst,
630 idType dfun `tcEqType` boot_inst_ty ] of
631 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
632 (dfun:_) -> return (Just (local_boot_dfun, dfun))
634 boot_dfun = instanceDFunId boot_inst
635 boot_inst_ty = idType boot_dfun
636 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
639 -- This has to compare the TyThing from the .hi-boot file to the TyThing
640 -- in the current source file. We must be careful to allow alpha-renaming
641 -- where appropriate, and also the boot declaration is allowed to omit
642 -- constructors and class methods.
644 -- See rnfail055 for a good test of this stuff.
646 checkBootDecl :: TyThing -> TyThing -> Bool
648 checkBootDecl (AnId id1) (AnId id2)
650 (idType id1 `tcEqType` idType id2)
652 checkBootDecl (ATyCon tc1) (ATyCon tc2)
653 = checkBootTyCon tc1 tc2
655 checkBootDecl (AClass c1) (AClass c2)
657 (clas_tyvars1, clas_fds1, sc_theta1, _, ats1, op_stuff1)
658 = classExtraBigSig c1
659 (clas_tyvars2, clas_fds2, sc_theta2, _, ats2, op_stuff2)
660 = classExtraBigSig c2
662 env0 = mkRnEnv2 emptyInScopeSet
663 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
665 eqSig (id1, def_meth1) (id2, def_meth2)
666 = idName id1 == idName id2 &&
667 tcEqTypeX env op_ty1 op_ty2 &&
668 def_meth1 == def_meth2
670 (_, rho_ty1) = splitForAllTys (idType id1)
671 op_ty1 = funResultTy rho_ty1
672 (_, rho_ty2) = splitForAllTys (idType id2)
673 op_ty2 = funResultTy rho_ty2
675 eqFD (as1,bs1) (as2,bs2) =
676 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
677 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
679 same_kind tv1 tv2 = eqKind (tyVarKind tv1) (tyVarKind tv2)
681 eqListBy same_kind clas_tyvars1 clas_tyvars2 &&
682 -- Checks kind of class
683 eqListBy eqFD clas_fds1 clas_fds2 &&
684 (null sc_theta1 && null op_stuff1 && null ats1
685 || -- Above tests for an "abstract" class
686 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
687 eqListBy eqSig op_stuff1 op_stuff2 &&
688 eqListBy checkBootTyCon ats1 ats2)
690 checkBootDecl (ADataCon dc1) (ADataCon _)
691 = pprPanic "checkBootDecl" (ppr dc1)
693 checkBootDecl _ _ = False -- probably shouldn't happen
696 checkBootTyCon :: TyCon -> TyCon -> Bool
697 checkBootTyCon tc1 tc2
698 | not (eqKind (tyConKind tc1) (tyConKind tc2))
699 = False -- First off, check the kind
701 | isSynTyCon tc1 && isSynTyCon tc2
703 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
704 env = rnBndrs2 env0 tvs1 tvs2
706 eqSynRhs (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
707 = tcEqTypeX env k1 k2
708 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
709 = tcEqTypeX env t1 t2
712 equalLength tvs1 tvs2 &&
713 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
715 | isAlgTyCon tc1 && isAlgTyCon tc2
717 eqKind (tyConKind tc1) (tyConKind tc2) &&
718 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2) &&
719 eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
721 | isForeignTyCon tc1 && isForeignTyCon tc2
722 = eqKind (tyConKind tc1) (tyConKind tc2) &&
723 tyConExtName tc1 == tyConExtName tc2
727 env0 = mkRnEnv2 emptyInScopeSet
729 eqAlgRhs AbstractTyCon _ = True
730 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
731 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
732 eqListBy eqCon (data_cons tc1) (data_cons tc2)
733 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
734 eqCon (data_con tc1) (data_con tc2)
738 = dataConName c1 == dataConName c2
739 && dataConIsInfix c1 == dataConIsInfix c2
740 && dataConStrictMarks c1 == dataConStrictMarks c2
741 && dataConFieldLabels c1 == dataConFieldLabels c2
742 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
743 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
744 env = rnBndrs2 env0 tvs1 tvs2
746 equalLength tvs1 tvs2 &&
747 eqListBy (tcEqPredX env)
748 (dataConEqTheta c1 ++ dataConDictTheta c1)
749 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
750 eqListBy (tcEqTypeX env)
751 (dataConOrigArgTys c1)
752 (dataConOrigArgTys c2)
755 missingBootThing :: Name -> String -> SDoc
756 missingBootThing name what
757 = ppr name <+> ptext (sLit "is exported by the hs-boot file, but not")
758 <+> text what <+> ptext (sLit "the module")
760 bootMisMatch :: TyThing -> IfaceDecl -> IfaceDecl -> SDoc
761 bootMisMatch thing boot_decl real_decl
762 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
763 ptext (sLit "Main module:") <+> ppr real_decl,
764 ptext (sLit "Boot file: ") <+> ppr boot_decl]
766 instMisMatch :: Instance -> SDoc
769 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
773 %************************************************************************
775 Type-checking the top level of a module
777 %************************************************************************
779 tcRnGroup takes a bunch of top-level source-code declarations, and
781 * gets supporting declarations from interface files
784 * and augments the TcGblEnv with the results
786 In Template Haskell it may be called repeatedly for each group of
787 declarations. It expects there to be an incoming TcGblEnv in the
788 monad; it augments it and returns the new TcGblEnv.
791 ------------------------------------------------
792 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
793 -- Fails if there are any errors
795 = do { -- Rename the source decls
796 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
798 -- save the renamed syntax, if we want it
800 | Just grp <- tcg_rn_decls tcg_env
801 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
805 -- Dump trace of renaming part
806 rnDump (ppr rn_decls) ;
808 return (tcg_env', rn_decls)
811 ------------------------------------------------
812 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
813 tcTopSrcDecls boot_details
814 (HsGroup { hs_tyclds = tycl_decls,
815 hs_instds = inst_decls,
816 hs_derivds = deriv_decls,
817 hs_fords = foreign_decls,
818 hs_defds = default_decls,
819 hs_annds = annotation_decls,
820 hs_ruleds = rule_decls,
821 hs_valds = val_binds })
822 = do { -- Type-check the type and class decls, and all imported decls
823 -- The latter come in via tycl_decls
824 traceTc (text "Tc2") ;
826 (tcg_env, aux_binds, dm_ids) <- tcTyAndClassDecls boot_details tycl_decls ;
827 -- If there are any errors, tcTyAndClassDecls fails here
830 tcExtendIdEnv dm_ids $ do {
832 -- Source-language instances, including derivings,
833 -- and import the supporting declarations
834 traceTc (text "Tc3") ;
835 (tcg_env, inst_infos, deriv_binds)
836 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
837 setGblEnv tcg_env $ do {
839 -- Foreign import declarations next.
840 traceTc (text "Tc4") ;
841 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
842 tcExtendGlobalValEnv fi_ids $ do {
844 -- Default declarations
845 traceTc (text "Tc4a") ;
846 default_tys <- tcDefaults default_decls ;
847 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
849 -- Now GHC-generated derived bindings, generics, and selectors
850 -- Do not generate warnings from compiler-generated code;
851 -- hence the use of discardWarnings
852 (tc_aux_binds, tcl_env) <- discardWarnings (tcTopBinds aux_binds) ;
853 (tc_deriv_binds, tcl_env) <- setLclTypeEnv tcl_env $
854 discardWarnings (tcTopBinds deriv_binds) ;
856 -- Value declarations next
857 traceTc (text "Tc5") ;
858 (tc_val_binds, tcl_env) <- setLclTypeEnv tcl_env $
859 tcTopBinds val_binds;
861 setLclTypeEnv tcl_env $ do { -- Environment doesn't change now
863 -- Second pass over class and instance declarations,
864 traceTc (text "Tc6") ;
865 inst_binds <- tcInstDecls2 tycl_decls inst_infos ;
866 showLIE (text "after instDecls2") ;
869 traceTc (text "Tc7") ;
870 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
873 annotations <- tcAnnotations annotation_decls ;
876 rules <- tcRules rule_decls ;
879 traceTc (text "Tc7a") ;
880 tcg_env <- getGblEnv ;
881 let { all_binds = tc_val_binds `unionBags`
882 tc_deriv_binds `unionBags`
883 tc_aux_binds `unionBags`
884 inst_binds `unionBags`
887 -- Extend the GblEnv with the (as yet un-zonked)
888 -- bindings, rules, foreign decls
889 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
890 tcg_rules = tcg_rules tcg_env ++ rules,
891 tcg_anns = tcg_anns tcg_env ++ annotations,
892 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
893 return (tcg_env', tcl_env)
898 %************************************************************************
902 %************************************************************************
905 checkMain :: TcM TcGblEnv
906 -- If we are in module Main, check that 'main' is defined.
908 = do { tcg_env <- getGblEnv ;
910 check_main dflags tcg_env
913 check_main :: DynFlags -> TcGblEnv -> TcM TcGblEnv
914 check_main dflags tcg_env
916 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
920 = do { mb_main <- lookupGlobalOccRn_maybe main_fn
921 -- Check that 'main' is in scope
922 -- It might be imported from another module!
924 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
929 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
930 ; let loc = srcLocSpan (getSrcLoc main_name)
931 ; ioTyCon <- tcLookupTyCon ioTyConName
932 ; (main_expr, res_ty)
933 <- addErrCtxt mainCtxt $
934 withBox liftedTypeKind $ \res_ty ->
935 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
937 -- See Note [Root-main Id]
938 -- Construct the binding
939 -- :Main.main :: IO res_ty = runMainIO res_ty main
940 ; run_main_id <- tcLookupId runMainIOName
941 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
942 (mkVarOccFS (fsLit "main"))
943 (getSrcSpan main_name)
944 ; root_main_id = Id.mkExportedLocalId root_main_name
945 (mkTyConApp ioTyCon [res_ty])
946 ; co = mkWpTyApps [res_ty]
947 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
948 ; main_bind = mkVarBind root_main_id rhs }
950 ; return (tcg_env { tcg_main = Just main_name,
951 tcg_binds = tcg_binds tcg_env
953 tcg_dus = tcg_dus tcg_env
954 `plusDU` usesOnly (unitFV main_name)
955 -- Record the use of 'main', so that we don't
956 -- complain about it being defined but not used
960 mod = tcg_mod tcg_env
961 main_mod = mainModIs dflags
962 main_fn = getMainFun dflags
964 complain_no_main | ghcLink dflags == LinkInMemory = return ()
965 | otherwise = failWithTc noMainMsg
966 -- In interactive mode, don't worry about the absence of 'main'
967 -- In other modes, fail altogether, so that we don't go on
968 -- and complain a second time when processing the export list.
970 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
971 noMainMsg = ptext (sLit "The") <+> pp_main_fn
972 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
973 pp_main_fn = ppMainFn main_fn
975 ppMainFn :: RdrName -> SDoc
977 | main_fn == main_RDR_Unqual
978 = ptext (sLit "function") <+> quotes (ppr main_fn)
980 = ptext (sLit "main function") <+> quotes (ppr main_fn)
982 -- | Get the unqualified name of the function to use as the \"main\" for the main module.
983 -- Either returns the default name or the one configured on the command line with -main-is
984 getMainFun :: DynFlags -> RdrName
985 getMainFun dflags = case (mainFunIs dflags) of
986 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
987 Nothing -> main_RDR_Unqual
989 checkMainExported :: TcGblEnv -> TcM ()
990 checkMainExported tcg_env = do
992 case tcg_main tcg_env of
993 Nothing -> return () -- not the main module
995 let main_mod = mainModIs dflags
996 checkTc (main_name `elem` concatMap availNames (tcg_exports tcg_env)) $
997 ptext (sLit "The") <+> ppMainFn (nameRdrName main_name) <+>
998 ptext (sLit "is not exported by module") <+> quotes (ppr main_mod)
1003 The function that the RTS invokes is always :Main.main, which we call
1004 root_main_id. (Because GHC allows the user to have a module not
1005 called Main as the main module, we can't rely on the main function
1006 being called "Main.main". That's why root_main_id has a fixed module
1009 This is unusual: it's a LocalId whose Name has a Module from another
1010 module. Tiresomely, we must filter it out again in MkIface, les we
1011 get two defns for 'main' in the interface file!
1014 %*********************************************************
1018 %*********************************************************
1021 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
1022 setInteractiveContext hsc_env icxt thing_inside
1023 = let -- Initialise the tcg_inst_env with instances from all home modules.
1024 -- This mimics the more selective call to hptInstances in tcRnModule.
1025 (home_insts, home_fam_insts) = hptInstances hsc_env (\_ -> True)
1027 updGblEnv (\env -> env {
1028 tcg_rdr_env = ic_rn_gbl_env icxt,
1029 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
1030 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
1034 tcExtendGhciEnv (ic_tmp_ids icxt) $
1035 -- tcExtendGhciEnv does lots:
1036 -- - it extends the local type env (tcl_env) with the given Ids,
1037 -- - it extends the local rdr env (tcl_rdr) with the Names from
1039 -- - it adds the free tyvars of the Ids to the tcl_tyvars
1042 -- later ids in ic_tmp_ids must shadow earlier ones with the same
1043 -- OccName, and tcExtendIdEnv implements this behaviour.
1045 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
1053 -> InteractiveContext
1055 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1056 -- The returned [Id] is the list of new Ids bound by
1057 -- this statement. It can be used to extend the
1058 -- InteractiveContext via extendInteractiveContext.
1060 -- The returned TypecheckedHsExpr is of type IO [ () ],
1061 -- a list of the bound values, coerced to ().
1063 tcRnStmt hsc_env ictxt rdr_stmt
1064 = initTcPrintErrors hsc_env iNTERACTIVE $
1065 setInteractiveContext hsc_env ictxt $ do {
1067 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1068 (([rn_stmt], _), fvs) <- rnStmts GhciStmt [rdr_stmt] (return ((), emptyFVs)) ;
1069 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1071 rnDump (ppr rn_stmt) ;
1073 -- The real work is done here
1074 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1075 zonked_expr <- zonkTopLExpr tc_expr ;
1076 zonked_ids <- zonkTopBndrs bound_ids ;
1078 -- None of the Ids should be of unboxed type, because we
1079 -- cast them all to HValues in the end!
1080 mapM_ bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1082 traceTc (text "tcs 1") ;
1083 let { global_ids = map globaliseAndTidyId zonked_ids } ;
1084 -- Note [Interactively-bound Ids in GHCi]
1086 {- ---------------------------------------------
1087 At one stage I removed any shadowed bindings from the type_env;
1088 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1089 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1091 Prelude> let f n = n * 2 :: Int
1092 Prelude> fName <- runQ [| f |]
1093 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1095 Prelude> let f n = n * 3 :: Int
1096 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1097 In the last line we use 'fName', which resolves to the *first* 'f'
1098 in scope. If we delete it from the type env, GHCi crashes because
1099 it doesn't expect that.
1101 Hence this code is commented out
1103 -------------------------------------------------- -}
1105 dumpOptTcRn Opt_D_dump_tc
1106 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1107 text "Typechecked expr" <+> ppr zonked_expr]) ;
1109 return (global_ids, zonked_expr)
1112 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1113 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1116 Note [Interactively-bound Ids in GHCi]
1117 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1118 The Ids bound by previous Stmts in Template Haskell are currently
1120 b) with an Internal Name (not External)
1121 c) and a tidied type
1123 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1124 compile an expression using these ids later, the byte code
1125 generator will consider the occurrences to be free rather than
1128 (b) They retain their Internal names becuase we don't have a suitable
1129 Module to name them with. We could revisit this choice.
1131 (c) Their types are tidied. This is important, because :info may ask
1132 to look at them, and :info expects the things it looks up to have
1136 --------------------------------------------------------------------------
1137 Typechecking Stmts in GHCi
1139 Here is the grand plan, implemented in tcUserStmt
1141 What you type The IO [HValue] that hscStmt returns
1142 ------------- ------------------------------------
1143 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1146 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1149 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1150 [NB: result not printed] bindings: [it]
1152 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1153 result showable) bindings: [it]
1155 expr (of non-IO type,
1156 result not showable) ==> error
1160 ---------------------------
1161 type PlanResult = ([Id], LHsExpr Id)
1162 type Plan = TcM PlanResult
1164 runPlans :: [Plan] -> TcM PlanResult
1165 -- Try the plans in order. If one fails (by raising an exn), try the next.
1166 -- If one succeeds, take it.
1167 runPlans [] = panic "runPlans"
1169 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1171 --------------------
1172 mkPlan :: LStmt Name -> TcM PlanResult
1173 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1174 = do { uniq <- newUnique -- is treated very specially
1175 ; let fresh_it = itName uniq
1176 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1177 matches = [mkMatch [] expr emptyLocalBinds]
1178 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1179 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1180 (HsVar bindIOName) noSyntaxExpr
1181 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1182 (HsVar thenIOName) placeHolderType
1185 -- [it <- e; print it] but not if it::()
1187 -- [let it = e; print it]
1188 ; runPlans [ -- Plan A
1189 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1190 ; it_ty <- zonkTcType (idType it_id)
1191 ; when (isUnitTy it_ty) failM
1194 -- Plan B; a naked bind statment
1195 tcGhciStmts [bind_stmt],
1197 -- Plan C; check that the let-binding is typeable all by itself.
1198 -- If not, fail; if so, try to print it.
1199 -- The two-step process avoids getting two errors: one from
1200 -- the expression itself, and one from the 'print it' part
1201 -- This two-step story is very clunky, alas
1202 do { _ <- checkNoErrs (tcGhciStmts [let_stmt])
1203 --- checkNoErrs defeats the error recovery of let-bindings
1204 ; tcGhciStmts [let_stmt, print_it] }
1207 mkPlan stmt@(L loc (BindStmt {}))
1208 | [v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1209 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1210 (HsVar thenIOName) placeHolderType
1212 ; print_bind_result <- doptM Opt_PrintBindResult
1213 ; let print_plan = do
1214 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1215 ; v_ty <- zonkTcType (idType v_id)
1216 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1220 -- [stmt; print v] but not if v::()
1222 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1223 [tcGhciStmts [stmt]])
1227 = tcGhciStmts [stmt]
1229 ---------------------------
1230 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1232 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1233 ret_id <- tcLookupId returnIOName ; -- return @ IO
1235 ret_ty = mkListTy unitTy ;
1236 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1237 tc_io_stmts stmts = tcStmts GhciStmt tcDoStmt stmts io_ret_ty ;
1239 names = collectLStmtsBinders stmts ;
1241 -- mk_return builds the expression
1242 -- returnIO @ [()] [coerce () x, .., coerce () z]
1244 -- Despite the inconvenience of building the type applications etc,
1245 -- this *has* to be done in type-annotated post-typecheck form
1246 -- because we are going to return a list of *polymorphic* values
1247 -- coerced to type (). If we built a *source* stmt
1248 -- return [coerce x, ..., coerce z]
1249 -- then the type checker would instantiate x..z, and we wouldn't
1250 -- get their *polymorphic* values. (And we'd get ambiguity errs
1251 -- if they were overloaded, since they aren't applied to anything.)
1252 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1253 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1254 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1258 -- OK, we're ready to typecheck the stmts
1259 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1260 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1261 mapM tcLookupId names ;
1262 -- Look up the names right in the middle,
1263 -- where they will all be in scope
1265 -- Simplify the context
1266 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1267 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1268 -- checkNoErrs ensures that the plan fails if context redn fails
1270 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1271 return (ids, mkHsDictLet const_binds $
1272 noLoc (HsDo GhciStmt tc_stmts (mk_return ids) io_ret_ty))
1277 tcRnExpr just finds the type of an expression
1281 -> InteractiveContext
1283 -> IO (Messages, Maybe Type)
1284 tcRnExpr hsc_env ictxt rdr_expr
1285 = initTcPrintErrors hsc_env iNTERACTIVE $
1286 setInteractiveContext hsc_env ictxt $ do {
1288 (rn_expr, _fvs) <- rnLExpr rdr_expr ;
1291 -- Now typecheck the expression;
1292 -- it might have a rank-2 type (e.g. :t runST)
1293 ((_tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1294 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1295 _ <- tcSimplifyInteractive lie_top ; -- Ignore the dicionary bindings
1297 let { all_expr_ty = mkForAllTys qtvs $
1298 mkFunTys (map (idType . instToId) dict_insts) $
1300 zonkTcType all_expr_ty
1303 smpl_doc = ptext (sLit "main expression")
1306 tcRnType just finds the kind of a type
1310 -> InteractiveContext
1312 -> IO (Messages, Maybe Kind)
1313 tcRnType hsc_env ictxt rdr_type
1314 = initTcPrintErrors hsc_env iNTERACTIVE $
1315 setInteractiveContext hsc_env ictxt $ do {
1317 rn_type <- rnLHsType doc rdr_type ;
1320 -- Now kind-check the type
1321 (_ty', kind) <- kcLHsType rn_type ;
1325 doc = ptext (sLit "In GHCi input")
1331 %************************************************************************
1333 More GHCi stuff, to do with browsing and getting info
1335 %************************************************************************
1339 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1340 -- a package module with an interface on disk. If neither of these is
1341 -- true, then the result will be an error indicating the interface
1342 -- could not be found.
1343 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1344 getModuleExports hsc_env mod
1347 checkMods = ic_toplev_scope ic ++ map fst (ic_exports ic)
1349 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1351 -- Get the export avail info and also load all orphan and family-instance
1352 -- modules. Finally, check that the family instances of all modules in the
1353 -- interactive context are consistent (these modules are in the second
1355 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1356 tcGetModuleExports mod directlyImpMods
1357 = do { let doc = ptext (sLit "context for compiling statements")
1358 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1360 -- Load any orphan-module and family instance-module
1361 -- interfaces, so their instances are visible.
1362 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1363 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1365 -- Check that the family instances of all directly loaded
1366 -- modules are consistent.
1367 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1369 ; ifaceExportNames (mi_exports iface)
1372 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1373 tcRnLookupRdrName hsc_env rdr_name
1374 = initTcPrintErrors hsc_env iNTERACTIVE $
1375 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1376 lookup_rdr_name rdr_name
1378 lookup_rdr_name :: RdrName -> TcM [Name]
1379 lookup_rdr_name rdr_name = do {
1380 -- If the identifier is a constructor (begins with an
1381 -- upper-case letter), then we need to consider both
1382 -- constructor and type class identifiers.
1383 let { rdr_names = dataTcOccs rdr_name } ;
1385 -- results :: [Either Messages Name]
1386 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1388 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1389 -- The successful lookups will be (Just name)
1390 let { (warns_s, good_names) = unzip [ (msgs, name)
1391 | (msgs, Just name) <- results] ;
1392 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1394 -- Fail if nothing good happened, else add warnings
1395 if null good_names then
1396 -- No lookup succeeded, so
1397 -- pick the first error message and report it
1398 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1399 -- while the other is "X is not in scope",
1400 -- we definitely want the former; but we might pick the latter
1401 do { addMessages (head errs_s) ; failM }
1402 else -- Add deprecation warnings
1403 mapM_ addMessages warns_s ;
1409 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1410 tcRnLookupName hsc_env name
1411 = initTcPrintErrors hsc_env iNTERACTIVE $
1412 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1413 tcRnLookupName' name
1415 -- To look up a name we have to look in the local environment (tcl_lcl)
1416 -- as well as the global environment, which is what tcLookup does.
1417 -- But we also want a TyThing, so we have to convert:
1419 tcRnLookupName' :: Name -> TcRn TyThing
1420 tcRnLookupName' name = do
1421 tcthing <- tcLookup name
1423 AGlobal thing -> return thing
1424 ATcId{tct_id=id} -> return (AnId id)
1425 _ -> panic "tcRnLookupName'"
1427 tcRnGetInfo :: HscEnv
1429 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1431 -- Used to implement :info in GHCi
1433 -- Look up a RdrName and return all the TyThings it might be
1434 -- A capitalised RdrName is given to us in the DataName namespace,
1435 -- but we want to treat it as *both* a data constructor
1436 -- *and* as a type or class constructor;
1437 -- hence the call to dataTcOccs, and we return up to two results
1438 tcRnGetInfo hsc_env name
1439 = initTcPrintErrors hsc_env iNTERACTIVE $
1440 tcRnGetInfo' hsc_env name
1442 tcRnGetInfo' :: HscEnv
1444 -> TcRn (TyThing, Fixity, [Instance])
1445 tcRnGetInfo' hsc_env name
1446 = let ictxt = hsc_IC hsc_env in
1447 setInteractiveContext hsc_env ictxt $ do
1449 -- Load the interface for all unqualified types and classes
1450 -- That way we will find all the instance declarations
1451 -- (Packages have not orphan modules, and we assume that
1452 -- in the home package all relevant modules are loaded.)
1453 loadUnqualIfaces ictxt
1455 thing <- tcRnLookupName' name
1456 fixity <- lookupFixityRn name
1457 ispecs <- lookupInsts thing
1458 return (thing, fixity, ispecs)
1460 lookupInsts :: TyThing -> TcM [Instance]
1461 lookupInsts (AClass cls)
1462 = do { inst_envs <- tcGetInstEnvs
1463 ; return (classInstances inst_envs cls) }
1465 lookupInsts (ATyCon tc)
1466 = do { (pkg_ie, home_ie) <- tcGetInstEnvs
1467 -- Load all instances for all classes that are
1468 -- in the type environment (which are all the ones
1469 -- we've seen in any interface file so far)
1470 ; return [ ispec -- Search all
1471 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1472 , let dfun = instanceDFunId ispec
1475 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1476 tc_name = tyConName tc
1478 lookupInsts _ = return []
1480 loadUnqualIfaces :: InteractiveContext -> TcM ()
1481 -- Load the home module for everything that is in scope unqualified
1482 -- This is so that we can accurately report the instances for
1484 loadUnqualIfaces ictxt
1486 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1488 unqual_mods = [ nameModule name
1489 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1490 let name = gre_name gre,
1491 not (isInternalName name),
1492 isTcOcc (nameOccName name), -- Types and classes only
1493 unQualOK gre ] -- In scope unqualified
1494 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1497 %************************************************************************
1501 %************************************************************************
1504 rnDump :: SDoc -> TcRn ()
1505 -- Dump, with a banner, if -ddump-rn
1506 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1508 tcDump :: TcGblEnv -> TcRn ()
1510 = do { dflags <- getDOpts ;
1512 -- Dump short output if -ddump-types or -ddump-tc
1513 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1514 (dumpTcRn short_dump) ;
1516 -- Dump bindings if -ddump-tc
1517 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1520 short_dump = pprTcGblEnv env
1521 full_dump = pprLHsBinds (tcg_binds env)
1522 -- NB: foreign x-d's have undefined's in their types;
1523 -- hence can't show the tc_fords
1525 tcCoreDump :: ModGuts -> TcM ()
1527 = do { dflags <- getDOpts ;
1528 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1529 (dumpTcRn (pprModGuts mod_guts)) ;
1531 -- Dump bindings if -ddump-tc
1532 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1534 full_dump = pprCoreBindings (mg_binds mod_guts)
1536 -- It's unpleasant having both pprModGuts and pprModDetails here
1537 pprTcGblEnv :: TcGblEnv -> SDoc
1538 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1540 tcg_fam_insts = fam_insts,
1542 tcg_imports = imports })
1543 = vcat [ ppr_types insts type_env
1544 , ppr_tycons fam_insts type_env
1546 , ppr_fam_insts fam_insts
1547 , vcat (map ppr rules)
1548 , ppr_gen_tycons (typeEnvTyCons type_env)
1549 , ptext (sLit "Dependent modules:") <+>
1550 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1551 , ptext (sLit "Dependent packages:") <+>
1552 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1553 where -- The two uses of sortBy are just to reduce unnecessary
1554 -- wobbling in testsuite output
1555 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1556 = (mod_name1 `stableModuleNameCmp` mod_name2)
1558 (is_boot1 `compare` is_boot2)
1560 pprModGuts :: ModGuts -> SDoc
1561 pprModGuts (ModGuts { mg_types = type_env,
1563 = vcat [ ppr_types [] type_env,
1566 ppr_types :: [Instance] -> TypeEnv -> SDoc
1567 ppr_types insts type_env
1568 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1570 dfun_ids = map instanceDFunId insts
1571 ids = [id | id <- typeEnvIds type_env, want_sig id]
1572 want_sig id | opt_PprStyle_Debug = True
1573 | otherwise = isLocalId id &&
1574 isExternalName (idName id) &&
1575 not (id `elem` dfun_ids)
1576 -- isLocalId ignores data constructors, records selectors etc.
1577 -- The isExternalName ignores local dictionary and method bindings
1578 -- that the type checker has invented. Top-level user-defined things
1579 -- have External names.
1581 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1582 ppr_tycons fam_insts type_env
1583 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1585 fi_tycons = map famInstTyCon fam_insts
1586 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1587 want_tycon tycon | opt_PprStyle_Debug = True
1588 | otherwise = not (isImplicitTyCon tycon) &&
1589 isExternalName (tyConName tycon) &&
1590 not (tycon `elem` fi_tycons)
1592 ppr_insts :: [Instance] -> SDoc
1593 ppr_insts [] = empty
1594 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1596 ppr_fam_insts :: [FamInst] -> SDoc
1597 ppr_fam_insts [] = empty
1598 ppr_fam_insts fam_insts =
1599 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1601 ppr_sigs :: [Var] -> SDoc
1603 -- Print type signatures; sort by OccName
1604 = vcat (map ppr_sig (sortLe le_sig ids))
1606 le_sig id1 id2 = getOccName id1 <= getOccName id2
1607 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1609 ppr_tydecls :: [TyCon] -> SDoc
1611 -- Print type constructor info; sort by OccName
1612 = vcat (map ppr_tycon (sortLe le_sig tycons))
1614 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1616 | isCoercionTyCon tycon
1617 = sep [ptext (sLit "coercion") <+> ppr tycon <+> ppr tvs
1618 , nest 2 (dcolon <+> pprEqPred (coercionKind (mkTyConApp tycon (mkTyVarTys tvs))))]
1619 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1621 tvs = take (tyConArity tycon) alphaTyVars
1623 ppr_rules :: [CoreRule] -> SDoc
1624 ppr_rules [] = empty
1625 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1626 nest 4 (pprRules rs),
1629 ppr_gen_tycons :: [TyCon] -> SDoc
1630 ppr_gen_tycons [] = empty
1631 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1632 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]