2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
5 \section[TcModule]{Typechecking a whole module}
9 -- The above warning supression flag is a temporary kludge.
10 -- While working on this module you are encouraged to remove it and fix
11 -- any warnings in the module. See
12 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
17 tcRnStmt, tcRnExpr, tcRnType,
30 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
59 import TcUnify ( withBox )
85 import Data.List ( sortBy )
97 import {- Kind parts of -} Type
99 import Foreign.Ptr( Ptr )
100 import TidyPgm ( globaliseAndTidyId )
109 import Data.Maybe ( isJust )
111 #include "HsVersions.h"
114 %************************************************************************
116 Typecheck and rename a module
118 %************************************************************************
124 -> Bool -- True <=> save renamed syntax
125 -> Located (HsModule RdrName)
126 -> IO (Messages, Maybe TcGblEnv)
128 tcRnModule hsc_env hsc_src save_rn_syntax
129 (L loc (HsModule maybe_mod export_ies
130 import_decls local_decls mod_deprec
132 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
134 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
135 this_mod = case maybe_mod of
136 Nothing -> mAIN -- 'module M where' is omitted
137 Just (L _ mod) -> mkModule this_pkg mod } ;
140 initTc hsc_env hsc_src save_rn_syntax this_mod $
142 do { -- Deal with imports;
143 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
144 setGblEnv tcg_env $ do {
146 -- Load the hi-boot interface for this module, if any
147 -- We do this now so that the boot_names can be passed
148 -- to tcTyAndClassDecls, because the boot_names are
149 -- automatically considered to be loop breakers
151 -- Do this *after* tcRnImports, so that we know whether
152 -- a module that we import imports us; and hence whether to
153 -- look for a hi-boot file
154 boot_iface <- tcHiBootIface hsc_src this_mod ;
156 -- Rename and type check the declarations
157 traceRn (text "rn1a") ;
158 tcg_env <- if isHsBoot hsc_src then
159 tcRnHsBootDecls local_decls
161 tcRnSrcDecls boot_iface local_decls ;
162 setGblEnv tcg_env $ do {
164 -- Report the use of any deprecated things
165 -- We do this *before* processsing the export list so
166 -- that we don't bleat about re-exporting a deprecated
167 -- thing (especially via 'module Foo' export item)
168 -- That is, only uses in the *body* of the module are complained about
169 traceRn (text "rn3") ;
170 failIfErrsM ; -- finishWarnings crashes sometimes
171 -- as a result of typechecker repairs (e.g. unboundNames)
172 tcg_env <- finishWarnings (hsc_dflags hsc_env) mod_deprec tcg_env ;
174 -- Process the export list
175 traceRn (text "rn4a: before exports");
176 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
177 traceRn (text "rn4b: after exportss") ;
179 -- Compare the hi-boot iface (if any) with the real thing
180 -- Must be done after processing the exports
181 tcg_env <- checkHiBootIface tcg_env boot_iface ;
183 -- The new type env is already available to stuff slurped from
184 -- interface files, via TcEnv.updateGlobalTypeEnv
185 -- It's important that this includes the stuff in checkHiBootIface,
186 -- because the latter might add new bindings for boot_dfuns,
187 -- which may be mentioned in imported unfoldings
189 -- Don't need to rename the Haddock documentation,
190 -- it's not parsed by GHC anymore.
191 tcg_env <- return (tcg_env { tcg_doc_hdr = maybe_doc_hdr }) ;
193 -- Report unused names
194 reportUnusedNames export_ies tcg_env ;
196 -- Dump output and return
203 %************************************************************************
207 %************************************************************************
210 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
211 tcRnImports hsc_env this_mod import_decls
212 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
214 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
215 ; dep_mods = imp_dep_mods imports
217 -- We want instance declarations from all home-package
218 -- modules below this one, including boot modules, except
219 -- ourselves. The 'except ourselves' is so that we don't
220 -- get the instances from this module's hs-boot file
221 ; want_instances :: ModuleName -> Bool
222 ; want_instances mod = mod `elemUFM` dep_mods
223 && mod /= moduleName this_mod
224 ; (home_insts, home_fam_insts) = hptInstances hsc_env
228 -- Record boot-file info in the EPS, so that it's
229 -- visible to loadHiBootInterface in tcRnSrcDecls,
230 -- and any other incrementally-performed imports
231 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
233 -- Update the gbl env
234 ; updGblEnv ( \ gbl ->
236 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
237 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
238 tcg_rn_imports = rn_imports,
239 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
240 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
245 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
246 -- Fail if there are any errors so far
247 -- The error printing (if needed) takes advantage
248 -- of the tcg_env we have now set
249 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
252 -- Load any orphan-module and family instance-module
253 -- interfaces, so that their rules and instance decls will be
255 ; loadOrphanModules (imp_orphs imports) False
256 ; loadOrphanModules (imp_finsts imports) True
258 -- Check type-familily consistency
259 ; traceRn (text "rn1: checking family instance consistency")
260 ; let { dir_imp_mods = moduleEnvKeys
263 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
269 %************************************************************************
271 Type-checking external-core modules
273 %************************************************************************
276 tcRnExtCore :: HscEnv
278 -> IO (Messages, Maybe ModGuts)
279 -- Nothing => some error occurred
281 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
282 -- The decls are IfaceDecls; all names are original names
283 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
285 initTc hsc_env ExtCoreFile False this_mod $ do {
287 let { ldecls = map noLoc decls } ;
289 -- bring the type and class decls into scope
290 -- ToDo: check that this doesn't need to extract the val binds.
291 -- It seems that only the type and class decls need to be in scope below because
292 -- (a) tcTyAndClassDecls doesn't need the val binds, and
293 -- (b) tcExtCoreBindings doesn't need anything
294 -- (in fact, it might not even need to be in the scope of
295 -- this tcg_env at all)
296 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
297 tc_envs <- extendGlobalRdrEnvRn avails emptyFsEnv {- no fixity decls -} ;
299 setEnvs tc_envs $ do {
301 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
303 -- Dump trace of renaming part
304 rnDump (ppr rn_decls) ;
306 -- Typecheck them all together so that
307 -- any mutually recursive types are done right
308 -- Just discard the auxiliary bindings; they are generated
309 -- only for Haskell source code, and should already be in Core
310 (tcg_env, _aux_binds) <- tcTyAndClassDecls emptyModDetails rn_decls ;
312 setGblEnv tcg_env $ do {
313 -- Make the new type env available to stuff slurped from interface files
315 -- Now the core bindings
316 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
320 bndrs = bindersOfBinds core_binds ;
321 my_exports = map (Avail . idName) bndrs ;
322 -- ToDo: export the data types also?
325 extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
327 mod_guts = ModGuts { mg_module = this_mod,
329 mg_used_names = emptyNameSet, -- ToDo: compute usage
330 mg_dir_imps = emptyModuleEnv, -- ??
331 mg_deps = noDependencies, -- ??
332 mg_exports = my_exports,
333 mg_types = final_type_env,
334 mg_insts = tcg_insts tcg_env,
335 mg_fam_insts = tcg_fam_insts tcg_env,
336 mg_inst_env = tcg_inst_env tcg_env,
337 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
339 mg_binds = core_binds,
342 mg_rdr_env = emptyGlobalRdrEnv,
343 mg_fix_env = emptyFixityEnv,
344 mg_warns = NoWarnings,
345 mg_foreign = NoStubs,
346 mg_hpc_info = emptyHpcInfo False,
347 mg_modBreaks = emptyModBreaks,
348 mg_vect_info = noVectInfo
351 tcCoreDump mod_guts ;
356 mkFakeGroup decls -- Rather clumsy; lots of unused fields
357 = emptyRdrGroup { hs_tyclds = decls }
361 %************************************************************************
363 Type-checking the top level of a module
365 %************************************************************************
368 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
369 -- Returns the variables free in the decls
370 -- Reason: solely to report unused imports and bindings
371 tcRnSrcDecls boot_iface decls
372 = do { -- Do all the declarations
373 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
375 -- Finish simplifying class constraints
377 -- tcSimplifyTop deals with constant or ambiguous InstIds.
378 -- How could there be ambiguous ones? They can only arise if a
379 -- top-level decl falls under the monomorphism restriction
380 -- and no subsequent decl instantiates its type.
382 -- We do this after checkMain, so that we use the type info
383 -- thaat checkMain adds
385 -- We do it with both global and local env in scope:
386 -- * the global env exposes the instances to tcSimplifyTop
387 -- * the local env exposes the local Ids to tcSimplifyTop,
388 -- so that we get better error messages (monomorphism restriction)
389 traceTc (text "Tc8") ;
390 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
392 -- Backsubstitution. This must be done last.
393 -- Even tcSimplifyTop may do some unification.
394 traceTc (text "Tc9") ;
395 let { (tcg_env, _) = tc_envs
396 ; TcGblEnv { tcg_type_env = type_env,
399 tcg_fords = fords } = tcg_env
400 ; all_binds = binds `unionBags` inst_binds } ;
402 failIfErrsM ; -- Don't zonk if there have been errors
403 -- It's a waste of time; and we may get debug warnings
404 -- about strangely-typed TyCons!
406 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
409 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
410 ; tcg_env' = tcg_env { tcg_binds = binds',
412 tcg_fords = fords' } } ;
414 setGlobalTypeEnv tcg_env' final_type_env
417 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
418 -- Loops around dealing with each top level inter-splice group
419 -- in turn, until it's dealt with the entire module
420 tc_rn_src_decls boot_details ds
421 = do { let { (first_group, group_tail) = findSplice ds } ;
422 -- If ds is [] we get ([], Nothing)
424 -- Deal with decls up to, but not including, the first splice
425 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
426 -- rnTopSrcDecls fails if there are any errors
428 (tcg_env, tcl_env) <- setGblEnv tcg_env $
429 tcTopSrcDecls boot_details rn_decls ;
431 -- If there is no splice, we're nearly done
432 setEnvs (tcg_env, tcl_env) $
434 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
435 return (tcg_env, tcl_env)
438 -- If there's a splice, we must carry on
439 Just (SpliceDecl splice_expr, rest_ds) -> do {
441 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
444 -- Rename the splice expression, and get its supporting decls
445 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
446 -- checkNoErrs: don't typecheck if renaming failed
447 rnDump (ppr rn_splice_expr) ;
449 -- Execute the splice
450 spliced_decls <- tcSpliceDecls rn_splice_expr ;
452 -- Glue them on the front of the remaining decls and loop
453 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
454 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
459 %************************************************************************
461 Compiling hs-boot source files, and
462 comparing the hi-boot interface with the real thing
464 %************************************************************************
467 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
468 tcRnHsBootDecls decls
469 = do { let { (first_group, group_tail) = findSplice decls }
472 Just stuff -> spliceInHsBootErr stuff
475 -- Rename the declarations
476 ; (tcg_env, HsGroup {
477 hs_tyclds = tycl_decls,
478 hs_instds = inst_decls,
479 hs_derivds = deriv_decls,
481 hs_defds = _, -- Todo: check no foreign decls, no rules,
482 hs_ruleds = _, -- no default decls and no annotation decls
484 hs_valds = val_binds }) <- rnTopSrcDecls first_group
485 ; setGblEnv tcg_env $ do {
488 -- Typecheck type/class decls
489 ; traceTc (text "Tc2")
490 ; (tcg_env, aux_binds) <- tcTyAndClassDecls emptyModDetails tycl_decls
491 ; setGblEnv tcg_env $ do {
493 -- Typecheck instance decls
494 ; traceTc (text "Tc3")
495 ; (tcg_env, inst_infos, _deriv_binds)
496 <- tcInstDecls1 tycl_decls inst_decls deriv_decls
497 ; setGblEnv tcg_env $ do {
499 -- Typecheck value declarations
500 ; traceTc (text "Tc5")
501 ; val_ids <- tcHsBootSigs val_binds
504 -- No simplification or zonking to do
505 ; traceTc (text "Tc7a")
506 ; gbl_env <- getGblEnv
508 -- Make the final type-env
509 -- Include the dfun_ids so that their type sigs
510 -- are written into the interface file.
511 -- And similarly the aux_ids from aux_binds
512 ; let { type_env0 = tcg_type_env gbl_env
513 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
514 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
515 ; type_env3 = extendTypeEnvWithIds type_env1 aux_ids
516 ; dfun_ids = map iDFunId inst_infos
517 ; aux_ids = case aux_binds of
518 ValBindsOut _ sigs -> [id | L _ (IdSig id) <- sigs]
519 _ -> panic "tcRnHsBoodDecls"
522 ; setGlobalTypeEnv gbl_env type_env2
525 spliceInHsBootErr (SpliceDecl (L loc _), _)
526 = addErrAt loc (ptext (sLit "Splices are not allowed in hs-boot files"))
529 Once we've typechecked the body of the module, we want to compare what
530 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
533 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
534 -- Compare the hi-boot file for this module (if there is one)
535 -- with the type environment we've just come up with
536 -- In the common case where there is no hi-boot file, the list
537 -- of boot_names is empty.
539 -- The bindings we return give bindings for the dfuns defined in the
540 -- hs-boot file, such as $fbEqT = $fEqT
543 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
544 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
545 tcg_type_env = local_type_env, tcg_exports = local_exports })
546 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
547 md_types = boot_type_env, md_exports = boot_exports })
548 | isHsBoot hs_src -- Current module is already a hs-boot file!
552 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
555 -- Check the exports of the boot module, one by one
556 ; mapM_ check_export boot_exports
558 -- Check for no family instances
559 ; unless (null boot_fam_insts) $
560 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
561 "instances in boot files yet...")
562 -- FIXME: Why? The actual comparison is not hard, but what would
563 -- be the equivalent to the dfun bindings returned for class
564 -- instances? We can't easily equate tycons...
566 -- Check instance declarations
567 ; mb_dfun_prs <- mapM check_inst boot_insts
568 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
569 final_type_env = extendTypeEnvWithIds local_type_env boot_dfuns
570 dfun_prs = catMaybes mb_dfun_prs
571 boot_dfuns = map fst dfun_prs
572 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
573 | (boot_dfun, dfun) <- dfun_prs ]
576 ; setGlobalTypeEnv tcg_env' final_type_env }
578 check_export boot_avail -- boot_avail is exported by the boot iface
579 | name `elem` dfun_names = return ()
580 | isWiredInName name = return () -- No checking for wired-in names. In particular,
581 -- 'error' is handled by a rather gross hack
582 -- (see comments in GHC.Err.hs-boot)
584 -- Check that the actual module exports the same thing
585 | not (null missing_names)
586 = addErrAt (nameSrcSpan (head missing_names))
587 (missingBootThing (head missing_names) "exported by")
589 -- If the boot module does not *define* the thing, we are done
590 -- (it simply re-exports it, and names match, so nothing further to do)
591 | isNothing mb_boot_thing = return ()
593 -- Check that the actual module also defines the thing, and
594 -- then compare the definitions
595 | Just real_thing <- lookupTypeEnv local_type_env name,
596 Just boot_thing <- mb_boot_thing
597 = when (not (checkBootDecl boot_thing real_thing))
598 $ addErrAt (nameSrcSpan (getName boot_thing))
599 (let boot_decl = tyThingToIfaceDecl
600 (fromJust mb_boot_thing)
601 real_decl = tyThingToIfaceDecl real_thing
602 in bootMisMatch real_thing boot_decl real_decl)
605 = addErrTc (missingBootThing name "defined in")
607 name = availName boot_avail
608 mb_boot_thing = lookupTypeEnv boot_type_env name
609 missing_names = case lookupNameEnv local_export_env name of
611 Just avail -> availNames boot_avail `minusList` availNames avail
613 dfun_names = map getName boot_insts
615 local_export_env :: NameEnv AvailInfo
616 local_export_env = availsToNameEnv local_exports
618 check_inst :: Instance -> TcM (Maybe (Id, Id))
619 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
621 = case [dfun | inst <- local_insts,
622 let dfun = instanceDFunId inst,
623 idType dfun `tcEqType` boot_inst_ty ] of
624 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
625 (dfun:_) -> return (Just (local_boot_dfun, dfun))
627 boot_dfun = instanceDFunId boot_inst
628 boot_inst_ty = idType boot_dfun
629 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
632 -- This has to compare the TyThing from the .hi-boot file to the TyThing
633 -- in the current source file. We must be careful to allow alpha-renaming
634 -- where appropriate, and also the boot declaration is allowed to omit
635 -- constructors and class methods.
637 -- See rnfail055 for a good test of this stuff.
639 checkBootDecl :: TyThing -> TyThing -> Bool
641 checkBootDecl (AnId id1) (AnId id2)
643 (idType id1 `tcEqType` idType id2)
645 checkBootDecl (ATyCon tc1) (ATyCon tc2)
646 = checkBootTyCon tc1 tc2
648 checkBootDecl (AClass c1) (AClass c2)
650 (clas_tyvars1, clas_fds1, sc_theta1, _, ats1, op_stuff1)
651 = classExtraBigSig c1
652 (clas_tyvars2, clas_fds2, sc_theta2, _, ats2, op_stuff2)
653 = classExtraBigSig c2
655 env0 = mkRnEnv2 emptyInScopeSet
656 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
658 eqSig (id1, def_meth1) (id2, def_meth2)
659 = idName id1 == idName id2 &&
660 tcEqTypeX env op_ty1 op_ty2
662 (_, rho_ty1) = splitForAllTys (idType id1)
663 op_ty1 = funResultTy rho_ty1
664 (_, rho_ty2) = splitForAllTys (idType id2)
665 op_ty2 = funResultTy rho_ty2
667 eqFD (as1,bs1) (as2,bs2) =
668 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
669 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
671 same_kind tv1 tv2 = eqKind (tyVarKind tv1) (tyVarKind tv2)
673 eqListBy same_kind clas_tyvars1 clas_tyvars2 &&
674 -- Checks kind of class
675 eqListBy eqFD clas_fds1 clas_fds2 &&
676 (null sc_theta1 && null op_stuff1 && null ats1
677 || -- Above tests for an "abstract" class
678 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
679 eqListBy eqSig op_stuff1 op_stuff2 &&
680 eqListBy checkBootTyCon ats1 ats2)
682 checkBootDecl (ADataCon dc1) (ADataCon dc2)
683 = pprPanic "checkBootDecl" (ppr dc1)
685 checkBootDecl _ _ = False -- probably shouldn't happen
688 checkBootTyCon :: TyCon -> TyCon -> Bool
689 checkBootTyCon tc1 tc2
690 | not (eqKind (tyConKind tc1) (tyConKind tc2))
691 = False -- First off, check the kind
693 | isSynTyCon tc1 && isSynTyCon tc2
695 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
696 env = rnBndrs2 env0 tvs1 tvs2
698 eqSynRhs (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
699 = tcEqTypeX env k1 k2
700 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
701 = tcEqTypeX env t1 t2
703 equalLength tvs1 tvs2 &&
704 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
706 | isAlgTyCon tc1 && isAlgTyCon tc2
708 eqKind (tyConKind tc1) (tyConKind tc2) &&
709 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2) &&
710 eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
712 | isForeignTyCon tc1 && isForeignTyCon tc2
713 = eqKind (tyConKind tc1) (tyConKind tc2) &&
714 tyConExtName tc1 == tyConExtName tc2
716 env0 = mkRnEnv2 emptyInScopeSet
718 eqAlgRhs AbstractTyCon _ = True
719 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
720 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
721 eqListBy eqCon (data_cons tc1) (data_cons tc2)
722 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
723 eqCon (data_con tc1) (data_con tc2)
727 = dataConName c1 == dataConName c2
728 && dataConIsInfix c1 == dataConIsInfix c2
729 && dataConStrictMarks c1 == dataConStrictMarks c2
730 && dataConFieldLabels c1 == dataConFieldLabels c2
731 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
732 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
733 env = rnBndrs2 env0 tvs1 tvs2
735 equalLength tvs1 tvs2 &&
736 eqListBy (tcEqPredX env)
737 (dataConEqTheta c1 ++ dataConDictTheta c1)
738 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
739 eqListBy (tcEqTypeX env)
740 (dataConOrigArgTys c1)
741 (dataConOrigArgTys c2)
744 missingBootThing thing what
745 = ppr thing <+> ptext (sLit "is exported by the hs-boot file, but not")
746 <+> text what <+> ptext (sLit "the module")
748 bootMisMatch thing boot_decl real_decl
749 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
750 ptext (sLit "Main module:") <+> ppr real_decl,
751 ptext (sLit "Boot file: ") <+> ppr boot_decl]
755 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
759 %************************************************************************
761 Type-checking the top level of a module
763 %************************************************************************
765 tcRnGroup takes a bunch of top-level source-code declarations, and
767 * gets supporting declarations from interface files
770 * and augments the TcGblEnv with the results
772 In Template Haskell it may be called repeatedly for each group of
773 declarations. It expects there to be an incoming TcGblEnv in the
774 monad; it augments it and returns the new TcGblEnv.
777 ------------------------------------------------
778 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
779 -- Fails if there are any errors
781 = do { -- Rename the source decls
782 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
784 -- save the renamed syntax, if we want it
786 | Just grp <- tcg_rn_decls tcg_env
787 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
791 -- Dump trace of renaming part
792 rnDump (ppr rn_decls) ;
794 return (tcg_env', rn_decls)
797 ------------------------------------------------
798 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
799 tcTopSrcDecls boot_details
800 (HsGroup { hs_tyclds = tycl_decls,
801 hs_instds = inst_decls,
802 hs_derivds = deriv_decls,
803 hs_fords = foreign_decls,
804 hs_defds = default_decls,
805 hs_annds = annotation_decls,
806 hs_ruleds = rule_decls,
807 hs_valds = val_binds })
808 = do { -- Type-check the type and class decls, and all imported decls
809 -- The latter come in via tycl_decls
810 traceTc (text "Tc2") ;
812 (tcg_env, aux_binds) <- tcTyAndClassDecls boot_details tycl_decls ;
813 -- If there are any errors, tcTyAndClassDecls fails here
815 setGblEnv tcg_env $ do {
816 -- Source-language instances, including derivings,
817 -- and import the supporting declarations
818 traceTc (text "Tc3") ;
819 (tcg_env, inst_infos, deriv_binds)
820 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
821 setGblEnv tcg_env $ do {
823 -- Foreign import declarations next.
824 traceTc (text "Tc4") ;
825 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
826 tcExtendGlobalValEnv fi_ids $ do {
828 -- Default declarations
829 traceTc (text "Tc4a") ;
830 default_tys <- tcDefaults default_decls ;
831 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
833 -- Now GHC-generated derived bindings, generics, and selectors
834 -- Do not generate warnings from compiler-generated code;
835 -- hence the use of discardWarnings
836 (tc_aux_binds, tcl_env) <- discardWarnings (tcTopBinds aux_binds) ;
837 (tc_deriv_binds, tcl_env) <- setLclTypeEnv tcl_env $
838 discardWarnings (tcTopBinds deriv_binds) ;
840 -- Value declarations next
841 traceTc (text "Tc5") ;
842 (tc_val_binds, tcl_env) <- setLclTypeEnv tcl_env $
843 tcTopBinds val_binds;
845 -- Second pass over class and instance declarations,
846 traceTc (text "Tc6") ;
847 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $
848 tcInstDecls2 tycl_decls inst_infos ;
849 showLIE (text "after instDecls2") ;
851 setLclTypeEnv tcl_env $ do { -- Environment doesn't change now
854 traceTc (text "Tc7") ;
855 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
858 annotations <- tcAnnotations annotation_decls ;
861 rules <- tcRules rule_decls ;
864 traceTc (text "Tc7a") ;
865 tcg_env <- getGblEnv ;
866 let { all_binds = tc_val_binds `unionBags`
867 tc_deriv_binds `unionBags`
868 tc_aux_binds `unionBags`
869 inst_binds `unionBags`
872 -- Extend the GblEnv with the (as yet un-zonked)
873 -- bindings, rules, foreign decls
874 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
875 tcg_rules = tcg_rules tcg_env ++ rules,
876 tcg_anns = tcg_anns tcg_env ++ annotations,
877 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
878 return (tcg_env', tcl_env)
883 %************************************************************************
887 %************************************************************************
890 checkMain :: TcM TcGblEnv
891 -- If we are in module Main, check that 'main' is defined.
893 = do { tcg_env <- getGblEnv ;
895 check_main dflags tcg_env
898 check_main dflags tcg_env
900 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
904 = do { mb_main <- lookupGlobalOccRn_maybe main_fn
905 -- Check that 'main' is in scope
906 -- It might be imported from another module!
908 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
913 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
914 ; let loc = srcLocSpan (getSrcLoc main_name)
915 ; ioTyCon <- tcLookupTyCon ioTyConName
916 ; (main_expr, res_ty)
917 <- addErrCtxt mainCtxt $
918 withBox liftedTypeKind $ \res_ty ->
919 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
921 -- See Note [Root-main Id]
922 -- Construct the binding
923 -- :Main.main :: IO res_ty = runMainIO res_ty main
924 ; run_main_id <- tcLookupId runMainIOName
925 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
926 (mkVarOccFS (fsLit "main"))
927 (getSrcSpan main_name)
928 ; root_main_id = Id.mkExportedLocalId root_main_name
929 (mkTyConApp ioTyCon [res_ty])
930 ; co = mkWpTyApps [res_ty]
931 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
932 ; main_bind = noLoc (VarBind root_main_id rhs) }
934 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
936 tcg_dus = tcg_dus tcg_env
937 `plusDU` usesOnly (unitFV main_name)
938 -- Record the use of 'main', so that we don't
939 -- complain about it being defined but not used
943 mod = tcg_mod tcg_env
944 main_mod = mainModIs dflags
945 main_fn = getMainFun dflags
947 complain_no_main | ghcLink dflags == LinkInMemory = return ()
948 | otherwise = failWithTc noMainMsg
949 -- In interactive mode, don't worry about the absence of 'main'
950 -- In other modes, fail altogether, so that we don't go on
951 -- and complain a second time when processing the export list.
953 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
954 noMainMsg = ptext (sLit "The") <+> pp_main_fn
955 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
956 pp_main_fn | main_fn == main_RDR_Unqual = ptext (sLit "function") <+> quotes (ppr main_fn)
957 | otherwise = ptext (sLit "main function") <+> quotes (ppr main_fn)
959 -- | Get the unqualified name of the function to use as the \"main\" for the main module.
960 -- Either returns the default name or the one configured on the command line with -main-is
961 getMainFun :: DynFlags -> RdrName
962 getMainFun dflags = case (mainFunIs dflags) of
963 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
964 Nothing -> main_RDR_Unqual
969 The function that the RTS invokes is always :Main.main, which we call
970 root_main_id. (Because GHC allows the user to have a module not
971 called Main as the main module, we can't rely on the main function
972 being called "Main.main". That's why root_main_id has a fixed module
975 This is unusual: it's a LocalId whose Name has a Module from another
976 module. Tiresomely, we must filter it out again in MkIface, les we
977 get two defns for 'main' in the interface file!
980 %*********************************************************
984 %*********************************************************
988 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
989 setInteractiveContext hsc_env icxt thing_inside
990 = let -- Initialise the tcg_inst_env with instances from all home modules.
991 -- This mimics the more selective call to hptInstances in tcRnModule.
992 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
994 updGblEnv (\env -> env {
995 tcg_rdr_env = ic_rn_gbl_env icxt,
996 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
997 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
1001 tcExtendGhciEnv (ic_tmp_ids icxt) $
1002 -- tcExtendGhciEnv does lots:
1003 -- - it extends the local type env (tcl_env) with the given Ids,
1004 -- - it extends the local rdr env (tcl_rdr) with the Names from
1006 -- - it adds the free tyvars of the Ids to the tcl_tyvars
1009 -- later ids in ic_tmp_ids must shadow earlier ones with the same
1010 -- OccName, and tcExtendIdEnv implements this behaviour.
1012 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
1019 -> InteractiveContext
1021 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1022 -- The returned [Id] is the list of new Ids bound by
1023 -- this statement. It can be used to extend the
1024 -- InteractiveContext via extendInteractiveContext.
1026 -- The returned TypecheckedHsExpr is of type IO [ () ],
1027 -- a list of the bound values, coerced to ().
1029 tcRnStmt hsc_env ictxt rdr_stmt
1030 = initTcPrintErrors hsc_env iNTERACTIVE $
1031 setInteractiveContext hsc_env ictxt $ do {
1033 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1034 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
1035 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1037 rnDump (ppr rn_stmt) ;
1039 -- The real work is done here
1040 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1041 zonked_expr <- zonkTopLExpr tc_expr ;
1042 zonked_ids <- zonkTopBndrs bound_ids ;
1044 -- None of the Ids should be of unboxed type, because we
1045 -- cast them all to HValues in the end!
1046 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1048 traceTc (text "tcs 1") ;
1049 let { global_ids = map globaliseAndTidyId zonked_ids } ;
1050 -- Note [Interactively-bound Ids in GHCi]
1052 {- ---------------------------------------------
1053 At one stage I removed any shadowed bindings from the type_env;
1054 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1055 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1057 Prelude> let f n = n * 2 :: Int
1058 Prelude> fName <- runQ [| f |]
1059 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1061 Prelude> let f n = n * 3 :: Int
1062 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1063 In the last line we use 'fName', which resolves to the *first* 'f'
1064 in scope. If we delete it from the type env, GHCi crashes because
1065 it doesn't expect that.
1067 Hence this code is commented out
1069 -------------------------------------------------- -}
1071 dumpOptTcRn Opt_D_dump_tc
1072 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1073 text "Typechecked expr" <+> ppr zonked_expr]) ;
1075 return (global_ids, zonked_expr)
1078 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1079 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1082 Note [Interactively-bound Ids in GHCi]
1083 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1084 The Ids bound by previous Stmts in Template Haskell are currently
1086 b) with an Internal Name (not External)
1087 c) and a tidied type
1089 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1090 compile an expression using these ids later, the byte code
1091 generator will consider the occurrences to be free rather than
1094 (b) They retain their Internal names becuase we don't have a suitable
1095 Module to name them with. We could revisit this choice.
1097 (c) Their types are tidied. This is important, because :info may ask
1098 to look at them, and :info expects the things it looks up to have
1102 --------------------------------------------------------------------------
1103 Typechecking Stmts in GHCi
1105 Here is the grand plan, implemented in tcUserStmt
1107 What you type The IO [HValue] that hscStmt returns
1108 ------------- ------------------------------------
1109 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1112 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1115 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1116 [NB: result not printed] bindings: [it]
1118 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1119 result showable) bindings: [it]
1121 expr (of non-IO type,
1122 result not showable) ==> error
1126 ---------------------------
1127 type PlanResult = ([Id], LHsExpr Id)
1128 type Plan = TcM PlanResult
1130 runPlans :: [Plan] -> TcM PlanResult
1131 -- Try the plans in order. If one fails (by raising an exn), try the next.
1132 -- If one succeeds, take it.
1133 runPlans [] = panic "runPlans"
1135 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1137 --------------------
1138 mkPlan :: LStmt Name -> TcM PlanResult
1139 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1140 = do { uniq <- newUnique -- is treated very specially
1141 ; let fresh_it = itName uniq
1142 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1143 matches = [mkMatch [] expr emptyLocalBinds]
1144 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1145 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1146 (HsVar bindIOName) noSyntaxExpr
1147 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1148 (HsVar thenIOName) placeHolderType
1151 -- [it <- e; print it] but not if it::()
1153 -- [let it = e; print it]
1154 ; runPlans [ -- Plan A
1155 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1156 ; it_ty <- zonkTcType (idType it_id)
1157 ; when (isUnitTy it_ty) failM
1160 -- Plan B; a naked bind statment
1161 tcGhciStmts [bind_stmt],
1163 -- Plan C; check that the let-binding is typeable all by itself.
1164 -- If not, fail; if so, try to print it.
1165 -- The two-step process avoids getting two errors: one from
1166 -- the expression itself, and one from the 'print it' part
1167 -- This two-step story is very clunky, alas
1168 do { checkNoErrs (tcGhciStmts [let_stmt])
1169 --- checkNoErrs defeats the error recovery of let-bindings
1170 ; tcGhciStmts [let_stmt, print_it] }
1173 mkPlan stmt@(L loc (BindStmt {}))
1174 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1175 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1176 (HsVar thenIOName) placeHolderType
1178 ; print_bind_result <- doptM Opt_PrintBindResult
1179 ; let print_plan = do
1180 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1181 ; v_ty <- zonkTcType (idType v_id)
1182 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1186 -- [stmt; print v] but not if v::()
1188 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1189 [tcGhciStmts [stmt]])
1193 = tcGhciStmts [stmt]
1195 ---------------------------
1196 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1198 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1199 ret_id <- tcLookupId returnIOName ; -- return @ IO
1201 ret_ty = mkListTy unitTy ;
1202 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1203 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1205 names = map unLoc (collectLStmtsBinders stmts) ;
1207 -- mk_return builds the expression
1208 -- returnIO @ [()] [coerce () x, .., coerce () z]
1210 -- Despite the inconvenience of building the type applications etc,
1211 -- this *has* to be done in type-annotated post-typecheck form
1212 -- because we are going to return a list of *polymorphic* values
1213 -- coerced to type (). If we built a *source* stmt
1214 -- return [coerce x, ..., coerce z]
1215 -- then the type checker would instantiate x..z, and we wouldn't
1216 -- get their *polymorphic* values. (And we'd get ambiguity errs
1217 -- if they were overloaded, since they aren't applied to anything.)
1218 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1219 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1220 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1224 -- OK, we're ready to typecheck the stmts
1225 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1226 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1227 mapM tcLookupId names ;
1228 -- Look up the names right in the middle,
1229 -- where they will all be in scope
1231 -- Simplify the context
1232 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1233 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1234 -- checkNoErrs ensures that the plan fails if context redn fails
1236 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1237 return (ids, mkHsDictLet const_binds $
1238 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1243 tcRnExpr just finds the type of an expression
1247 -> InteractiveContext
1249 -> IO (Messages, Maybe Type)
1250 tcRnExpr hsc_env ictxt rdr_expr
1251 = initTcPrintErrors hsc_env iNTERACTIVE $
1252 setInteractiveContext hsc_env ictxt $ do {
1254 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1257 -- Now typecheck the expression;
1258 -- it might have a rank-2 type (e.g. :t runST)
1259 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1260 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1261 tcSimplifyInteractive lie_top ;
1263 let { all_expr_ty = mkForAllTys qtvs $
1264 mkFunTys (map (idType . instToId) dict_insts) $
1266 zonkTcType all_expr_ty
1269 smpl_doc = ptext (sLit "main expression")
1272 tcRnType just finds the kind of a type
1276 -> InteractiveContext
1278 -> IO (Messages, Maybe Kind)
1279 tcRnType hsc_env ictxt rdr_type
1280 = initTcPrintErrors hsc_env iNTERACTIVE $
1281 setInteractiveContext hsc_env ictxt $ do {
1283 rn_type <- rnLHsType doc rdr_type ;
1286 -- Now kind-check the type
1287 (ty', kind) <- kcLHsType rn_type ;
1291 doc = ptext (sLit "In GHCi input")
1297 %************************************************************************
1299 More GHCi stuff, to do with browsing and getting info
1301 %************************************************************************
1305 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1306 -- a package module with an interface on disk. If neither of these is
1307 -- true, then the result will be an error indicating the interface
1308 -- could not be found.
1309 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1310 getModuleExports hsc_env mod
1313 checkMods = ic_toplev_scope ic ++ ic_exports ic
1315 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1317 -- Get the export avail info and also load all orphan and family-instance
1318 -- modules. Finally, check that the family instances of all modules in the
1319 -- interactive context are consistent (these modules are in the second
1321 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1322 tcGetModuleExports mod directlyImpMods
1323 = do { let doc = ptext (sLit "context for compiling statements")
1324 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1326 -- Load any orphan-module and family instance-module
1327 -- interfaces, so their instances are visible.
1328 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1329 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1331 -- Check that the family instances of all directly loaded
1332 -- modules are consistent.
1333 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1335 ; ifaceExportNames (mi_exports iface)
1338 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1339 tcRnLookupRdrName hsc_env rdr_name
1340 = initTcPrintErrors hsc_env iNTERACTIVE $
1341 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1342 lookup_rdr_name rdr_name
1344 lookup_rdr_name rdr_name = do {
1345 -- If the identifier is a constructor (begins with an
1346 -- upper-case letter), then we need to consider both
1347 -- constructor and type class identifiers.
1348 let { rdr_names = dataTcOccs rdr_name } ;
1350 -- results :: [Either Messages Name]
1351 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1353 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1354 -- The successful lookups will be (Just name)
1355 let { (warns_s, good_names) = unzip [ (msgs, name)
1356 | (msgs, Just name) <- results] ;
1357 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1359 -- Fail if nothing good happened, else add warnings
1360 if null good_names then
1361 -- No lookup succeeded, so
1362 -- pick the first error message and report it
1363 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1364 -- while the other is "X is not in scope",
1365 -- we definitely want the former; but we might pick the latter
1366 do { addMessages (head errs_s) ; failM }
1367 else -- Add deprecation warnings
1368 mapM_ addMessages warns_s ;
1373 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1374 tcRnLookupName hsc_env name
1375 = initTcPrintErrors hsc_env iNTERACTIVE $
1376 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1377 tcRnLookupName' name
1379 -- To look up a name we have to look in the local environment (tcl_lcl)
1380 -- as well as the global environment, which is what tcLookup does.
1381 -- But we also want a TyThing, so we have to convert:
1383 tcRnLookupName' :: Name -> TcRn TyThing
1384 tcRnLookupName' name = do
1385 tcthing <- tcLookup name
1387 AGlobal thing -> return thing
1388 ATcId{tct_id=id} -> return (AnId id)
1389 _ -> panic "tcRnLookupName'"
1391 tcRnGetInfo :: HscEnv
1393 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1395 -- Used to implemnent :info in GHCi
1397 -- Look up a RdrName and return all the TyThings it might be
1398 -- A capitalised RdrName is given to us in the DataName namespace,
1399 -- but we want to treat it as *both* a data constructor
1400 -- *and* as a type or class constructor;
1401 -- hence the call to dataTcOccs, and we return up to two results
1402 tcRnGetInfo hsc_env name
1403 = initTcPrintErrors hsc_env iNTERACTIVE $
1404 let ictxt = hsc_IC hsc_env in
1405 setInteractiveContext hsc_env ictxt $ do
1407 -- Load the interface for all unqualified types and classes
1408 -- That way we will find all the instance declarations
1409 -- (Packages have not orphan modules, and we assume that
1410 -- in the home package all relevant modules are loaded.)
1411 loadUnqualIfaces ictxt
1413 thing <- tcRnLookupName' name
1414 fixity <- lookupFixityRn name
1415 ispecs <- lookupInsts thing
1416 return (thing, fixity, ispecs)
1418 lookupInsts :: TyThing -> TcM [Instance]
1419 lookupInsts (AClass cls)
1420 = do { inst_envs <- tcGetInstEnvs
1421 ; return (classInstances inst_envs cls) }
1423 lookupInsts (ATyCon tc)
1424 = do { eps <- getEps -- Load all instances for all classes that are
1425 -- in the type environment (which are all the ones
1426 -- we've seen in any interface file so far)
1427 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1429 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1430 , let dfun = instanceDFunId ispec
1433 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1434 tc_name = tyConName tc
1436 lookupInsts other = return []
1438 loadUnqualIfaces :: InteractiveContext -> TcM ()
1439 -- Load the home module for everything that is in scope unqualified
1440 -- This is so that we can accurately report the instances for
1442 loadUnqualIfaces ictxt
1444 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1446 unqual_mods = [ nameModule name
1447 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1448 let name = gre_name gre,
1449 not (isInternalName name),
1450 isTcOcc (nameOccName name), -- Types and classes only
1451 unQualOK gre ] -- In scope unqualified
1452 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1456 %************************************************************************
1460 %************************************************************************
1463 rnDump :: SDoc -> TcRn ()
1464 -- Dump, with a banner, if -ddump-rn
1465 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1467 tcDump :: TcGblEnv -> TcRn ()
1469 = do { dflags <- getDOpts ;
1471 -- Dump short output if -ddump-types or -ddump-tc
1472 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1473 (dumpTcRn short_dump) ;
1475 -- Dump bindings if -ddump-tc
1476 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1479 short_dump = pprTcGblEnv env
1480 full_dump = pprLHsBinds (tcg_binds env)
1481 -- NB: foreign x-d's have undefined's in their types;
1482 -- hence can't show the tc_fords
1485 = do { dflags <- getDOpts ;
1486 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1487 (dumpTcRn (pprModGuts mod_guts)) ;
1489 -- Dump bindings if -ddump-tc
1490 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1492 full_dump = pprCoreBindings (mg_binds mod_guts)
1494 -- It's unpleasant having both pprModGuts and pprModDetails here
1495 pprTcGblEnv :: TcGblEnv -> SDoc
1496 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1498 tcg_fam_insts = fam_insts,
1500 tcg_imports = imports })
1501 = vcat [ ppr_types insts type_env
1502 , ppr_tycons fam_insts type_env
1504 , ppr_fam_insts fam_insts
1505 , vcat (map ppr rules)
1506 , ppr_gen_tycons (typeEnvTyCons type_env)
1507 , ptext (sLit "Dependent modules:") <+>
1508 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1509 , ptext (sLit "Dependent packages:") <+>
1510 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1511 where -- The two uses of sortBy are just to reduce unnecessary
1512 -- wobbling in testsuite output
1513 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1514 = (mod_name1 `stableModuleNameCmp` mod_name2)
1516 (is_boot1 `compare` is_boot2)
1518 pprModGuts :: ModGuts -> SDoc
1519 pprModGuts (ModGuts { mg_types = type_env,
1521 = vcat [ ppr_types [] type_env,
1524 ppr_types :: [Instance] -> TypeEnv -> SDoc
1525 ppr_types insts type_env
1526 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1528 dfun_ids = map instanceDFunId insts
1529 ids = [id | id <- typeEnvIds type_env, want_sig id]
1530 want_sig id | opt_PprStyle_Debug = True
1531 | otherwise = isLocalId id &&
1532 isExternalName (idName id) &&
1533 not (id `elem` dfun_ids)
1534 -- isLocalId ignores data constructors, records selectors etc.
1535 -- The isExternalName ignores local dictionary and method bindings
1536 -- that the type checker has invented. Top-level user-defined things
1537 -- have External names.
1539 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1540 ppr_tycons fam_insts type_env
1541 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1543 fi_tycons = map famInstTyCon fam_insts
1544 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1545 want_tycon tycon | opt_PprStyle_Debug = True
1546 | otherwise = not (isImplicitTyCon tycon) &&
1547 isExternalName (tyConName tycon) &&
1548 not (tycon `elem` fi_tycons)
1550 ppr_insts :: [Instance] -> SDoc
1551 ppr_insts [] = empty
1552 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1554 ppr_fam_insts :: [FamInst] -> SDoc
1555 ppr_fam_insts [] = empty
1556 ppr_fam_insts fam_insts =
1557 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1559 ppr_sigs :: [Var] -> SDoc
1561 -- Print type signatures; sort by OccName
1562 = vcat (map ppr_sig (sortLe le_sig ids))
1564 le_sig id1 id2 = getOccName id1 <= getOccName id2
1565 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1567 ppr_tydecls :: [TyCon] -> SDoc
1569 -- Print type constructor info; sort by OccName
1570 = vcat (map ppr_tycon (sortLe le_sig tycons))
1572 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1574 | isCoercionTyCon tycon = ptext (sLit "coercion") <+> ppr tycon
1575 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1577 ppr_rules :: [CoreRule] -> SDoc
1578 ppr_rules [] = empty
1579 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1580 nest 4 (pprRules rs),
1583 ppr_gen_tycons [] = empty
1584 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1585 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]