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"
116 %************************************************************************
118 Typecheck and rename a module
120 %************************************************************************
126 -> Bool -- True <=> save renamed syntax
127 -> Located (HsModule RdrName)
128 -> IO (Messages, Maybe TcGblEnv)
130 tcRnModule hsc_env hsc_src save_rn_syntax
131 (L loc (HsModule maybe_mod export_ies
132 import_decls local_decls mod_deprec
133 module_info maybe_doc))
134 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
136 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
137 this_mod = case maybe_mod of
138 Nothing -> mAIN -- 'module M where' is omitted
139 Just (L _ mod) -> mkModule this_pkg mod } ;
142 initTc hsc_env hsc_src save_rn_syntax this_mod $
144 do { -- Deal with imports;
145 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
146 setGblEnv tcg_env $ do {
148 -- Load the hi-boot interface for this module, if any
149 -- We do this now so that the boot_names can be passed
150 -- to tcTyAndClassDecls, because the boot_names are
151 -- automatically considered to be loop breakers
153 -- Do this *after* tcRnImports, so that we know whether
154 -- a module that we import imports us; and hence whether to
155 -- look for a hi-boot file
156 boot_iface <- tcHiBootIface hsc_src this_mod ;
158 -- Rename and type check the declarations
159 traceRn (text "rn1a") ;
160 tcg_env <- if isHsBoot hsc_src then
161 tcRnHsBootDecls local_decls
163 tcRnSrcDecls boot_iface local_decls ;
164 setGblEnv tcg_env $ do {
166 -- Report the use of any deprecated things
167 -- We do this *before* processsing the export list so
168 -- that we don't bleat about re-exporting a deprecated
169 -- thing (especially via 'module Foo' export item)
170 -- That is, only uses in the *body* of the module are complained about
171 traceRn (text "rn3") ;
172 failIfErrsM ; -- finishWarnings crashes sometimes
173 -- as a result of typechecker repairs (e.g. unboundNames)
174 tcg_env <- finishWarnings (hsc_dflags hsc_env) mod_deprec tcg_env ;
176 -- Process the export list
177 traceRn (text "rn4a: before exports");
178 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
179 traceRn (text "rn4b: after exportss") ;
181 -- Compare the hi-boot iface (if any) with the real thing
182 -- Must be done after processing the exports
183 tcg_env <- checkHiBootIface tcg_env boot_iface ;
185 -- The new type env is already available to stuff slurped from
186 -- interface files, via TcEnv.updateGlobalTypeEnv
187 -- It's important that this includes the stuff in checkHiBootIface,
188 -- because the latter might add new bindings for boot_dfuns,
189 -- which may be mentioned in imported unfoldings
191 -- Rename the Haddock documentation
192 tcg_env <- rnHaddock module_info maybe_doc tcg_env ;
194 -- Report unused names
195 reportUnusedNames export_ies tcg_env ;
197 -- Dump output and return
204 %************************************************************************
208 %************************************************************************
211 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
212 tcRnImports hsc_env this_mod import_decls
213 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
215 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
216 ; dep_mods = imp_dep_mods imports
218 -- We want instance declarations from all home-package
219 -- modules below this one, including boot modules, except
220 -- ourselves. The 'except ourselves' is so that we don't
221 -- get the instances from this module's hs-boot file
222 ; want_instances :: ModuleName -> Bool
223 ; want_instances mod = mod `elemUFM` dep_mods
224 && mod /= moduleName this_mod
225 ; (home_insts, home_fam_insts) = hptInstances hsc_env
229 -- Record boot-file info in the EPS, so that it's
230 -- visible to loadHiBootInterface in tcRnSrcDecls,
231 -- and any other incrementally-performed imports
232 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
234 -- Update the gbl env
235 ; updGblEnv ( \ gbl ->
237 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
238 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
239 tcg_rn_imports = rn_imports,
240 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
241 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
246 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
247 -- Fail if there are any errors so far
248 -- The error printing (if needed) takes advantage
249 -- of the tcg_env we have now set
250 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
253 -- Load any orphan-module and family instance-module
254 -- interfaces, so that their rules and instance decls will be
256 ; loadOrphanModules (imp_orphs imports) False
257 ; loadOrphanModules (imp_finsts imports) True
259 -- Check type-familily consistency
260 ; traceRn (text "rn1: checking family instance consistency")
261 ; let { dir_imp_mods = moduleEnvKeys
264 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
270 %************************************************************************
272 Type-checking external-core modules
274 %************************************************************************
277 tcRnExtCore :: HscEnv
279 -> IO (Messages, Maybe ModGuts)
280 -- Nothing => some error occurred
282 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
283 -- The decls are IfaceDecls; all names are original names
284 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
286 initTc hsc_env ExtCoreFile False this_mod $ do {
288 let { ldecls = map noLoc decls } ;
290 -- bring the type and class decls into scope
291 -- ToDo: check that this doesn't need to extract the val binds.
292 -- It seems that only the type and class decls need to be in scope below because
293 -- (a) tcTyAndClassDecls doesn't need the val binds, and
294 -- (b) tcExtCoreBindings doesn't need anything
295 -- (in fact, it might not even need to be in the scope of
296 -- this tcg_env at all)
297 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
298 tc_envs <- extendGlobalRdrEnvRn avails emptyFsEnv {- no fixity decls -} ;
300 setEnvs tc_envs $ do {
302 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
304 -- Dump trace of renaming part
305 rnDump (ppr rn_decls) ;
307 -- Typecheck them all together so that
308 -- any mutually recursive types are done right
309 -- Just discard the auxiliary bindings; they are generated
310 -- only for Haskell source code, and should already be in Core
311 (tcg_env, _aux_binds) <- tcTyAndClassDecls emptyModDetails rn_decls ;
313 setGblEnv tcg_env $ do {
314 -- Make the new type env available to stuff slurped from interface files
316 -- Now the core bindings
317 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
321 bndrs = bindersOfBinds core_binds ;
322 my_exports = map (Avail . idName) bndrs ;
323 -- ToDo: export the data types also?
326 extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
328 mod_guts = ModGuts { mg_module = this_mod,
330 mg_used_names = emptyNameSet, -- ToDo: compute usage
331 mg_dir_imps = emptyModuleEnv, -- ??
332 mg_deps = noDependencies, -- ??
333 mg_exports = my_exports,
334 mg_types = final_type_env,
335 mg_insts = tcg_insts tcg_env,
336 mg_fam_insts = tcg_fam_insts tcg_env,
337 mg_inst_env = tcg_inst_env tcg_env,
338 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
340 mg_binds = core_binds,
343 mg_rdr_env = emptyGlobalRdrEnv,
344 mg_fix_env = emptyFixityEnv,
345 mg_warns = NoWarnings,
346 mg_foreign = NoStubs,
347 mg_hpc_info = emptyHpcInfo False,
348 mg_modBreaks = emptyModBreaks,
349 mg_vect_info = noVectInfo
352 tcCoreDump mod_guts ;
357 mkFakeGroup decls -- Rather clumsy; lots of unused fields
358 = emptyRdrGroup { hs_tyclds = decls }
362 %************************************************************************
364 Type-checking the top level of a module
366 %************************************************************************
369 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
370 -- Returns the variables free in the decls
371 -- Reason: solely to report unused imports and bindings
372 tcRnSrcDecls boot_iface decls
373 = do { -- Do all the declarations
374 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
376 -- Finish simplifying class constraints
378 -- tcSimplifyTop deals with constant or ambiguous InstIds.
379 -- How could there be ambiguous ones? They can only arise if a
380 -- top-level decl falls under the monomorphism restriction
381 -- and no subsequent decl instantiates its type.
383 -- We do this after checkMain, so that we use the type info
384 -- thaat checkMain adds
386 -- We do it with both global and local env in scope:
387 -- * the global env exposes the instances to tcSimplifyTop
388 -- * the local env exposes the local Ids to tcSimplifyTop,
389 -- so that we get better error messages (monomorphism restriction)
390 traceTc (text "Tc8") ;
391 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
393 -- Backsubstitution. This must be done last.
394 -- Even tcSimplifyTop may do some unification.
395 traceTc (text "Tc9") ;
396 let { (tcg_env, _) = tc_envs
397 ; TcGblEnv { tcg_type_env = type_env,
400 tcg_fords = fords } = tcg_env
401 ; all_binds = binds `unionBags` inst_binds } ;
403 failIfErrsM ; -- Don't zonk if there have been errors
404 -- It's a waste of time; and we may get debug warnings
405 -- about strangely-typed TyCons!
407 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
410 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
411 ; tcg_env' = tcg_env { tcg_binds = binds',
413 tcg_fords = fords' } } ;
415 setGlobalTypeEnv tcg_env' final_type_env
418 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
419 -- Loops around dealing with each top level inter-splice group
420 -- in turn, until it's dealt with the entire module
421 tc_rn_src_decls boot_details ds
422 = do { let { (first_group, group_tail) = findSplice ds } ;
423 -- If ds is [] we get ([], Nothing)
425 -- Deal with decls up to, but not including, the first splice
426 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
427 -- rnTopSrcDecls fails if there are any errors
429 (tcg_env, tcl_env) <- setGblEnv tcg_env $
430 tcTopSrcDecls boot_details rn_decls ;
432 -- If there is no splice, we're nearly done
433 setEnvs (tcg_env, tcl_env) $
435 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
436 return (tcg_env, tcl_env)
439 -- If there's a splice, we must carry on
440 Just (SpliceDecl splice_expr, rest_ds) -> do {
442 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
445 -- Rename the splice expression, and get its supporting decls
446 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
447 -- checkNoErrs: don't typecheck if renaming failed
448 rnDump (ppr rn_splice_expr) ;
450 -- Execute the splice
451 spliced_decls <- tcSpliceDecls rn_splice_expr ;
453 -- Glue them on the front of the remaining decls and loop
454 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
455 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
460 %************************************************************************
462 Compiling hs-boot source files, and
463 comparing the hi-boot interface with the real thing
465 %************************************************************************
468 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
469 tcRnHsBootDecls decls
470 = do { let { (first_group, group_tail) = findSplice decls }
473 Just stuff -> spliceInHsBootErr stuff
476 -- Rename the declarations
477 ; (tcg_env, HsGroup {
478 hs_tyclds = tycl_decls,
479 hs_instds = inst_decls,
480 hs_derivds = deriv_decls,
482 hs_defds = _, -- Todo: check no foreign decls, no rules,
483 hs_ruleds = _, -- no default decls and no annotation decls
485 hs_valds = val_binds }) <- rnTopSrcDecls first_group
486 ; setGblEnv tcg_env $ do {
489 -- Typecheck type/class decls
490 ; traceTc (text "Tc2")
491 ; (tcg_env, aux_binds) <- tcTyAndClassDecls emptyModDetails tycl_decls
492 ; setGblEnv tcg_env $ do {
494 -- Typecheck instance decls
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_env1 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_env2
526 spliceInHsBootErr (SpliceDecl (L loc _), _)
527 = addErrAt loc (ptext (sLit "Splices are not allowed in hs-boot files"))
530 Once we've typechecked the body of the module, we want to compare what
531 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
534 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
535 -- Compare the hi-boot file for this module (if there is one)
536 -- with the type environment we've just come up with
537 -- In the common case where there is no hi-boot file, the list
538 -- of boot_names is empty.
540 -- The bindings we return give bindings for the dfuns defined in the
541 -- hs-boot file, such as $fbEqT = $fEqT
544 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
545 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
546 tcg_type_env = local_type_env, tcg_exports = local_exports })
547 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
548 md_types = boot_type_env, md_exports = boot_exports })
549 | isHsBoot hs_src -- Current module is already a hs-boot file!
553 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
556 -- Check the exports of the boot module, one by one
557 ; mapM_ check_export boot_exports
559 -- Check for no family instances
560 ; unless (null boot_fam_insts) $
561 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
562 "instances in boot files yet...")
563 -- FIXME: Why? The actual comparison is not hard, but what would
564 -- be the equivalent to the dfun bindings returned for class
565 -- instances? We can't easily equate tycons...
567 -- Check instance declarations
568 ; mb_dfun_prs <- mapM check_inst boot_insts
569 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
570 final_type_env = extendTypeEnvWithIds local_type_env boot_dfuns
571 dfun_prs = catMaybes mb_dfun_prs
572 boot_dfuns = map fst dfun_prs
573 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
574 | (boot_dfun, dfun) <- dfun_prs ]
577 ; setGlobalTypeEnv tcg_env' final_type_env }
579 check_export boot_avail -- boot_avail is exported by the boot iface
580 | name `elem` dfun_names = return ()
581 | isWiredInName name = return () -- No checking for wired-in names. In particular,
582 -- 'error' is handled by a rather gross hack
583 -- (see comments in GHC.Err.hs-boot)
585 -- Check that the actual module exports the same thing
586 | not (null missing_names)
587 = addErrAt (nameSrcSpan (head missing_names))
588 (missingBootThing (head missing_names) "exported by")
590 -- If the boot module does not *define* the thing, we are done
591 -- (it simply re-exports it, and names match, so nothing further to do)
592 | isNothing mb_boot_thing = return ()
594 -- Check that the actual module also defines the thing, and
595 -- then compare the definitions
596 | Just real_thing <- lookupTypeEnv local_type_env name,
597 Just boot_thing <- mb_boot_thing
598 = when (not (checkBootDecl boot_thing real_thing))
599 $ addErrAt (nameSrcSpan (getName boot_thing))
600 (let boot_decl = tyThingToIfaceDecl
601 (fromJust mb_boot_thing)
602 real_decl = tyThingToIfaceDecl real_thing
603 in bootMisMatch real_thing boot_decl real_decl)
606 = addErrTc (missingBootThing name "defined in")
608 name = availName boot_avail
609 mb_boot_thing = lookupTypeEnv boot_type_env name
610 missing_names = case lookupNameEnv local_export_env name of
612 Just avail -> availNames boot_avail `minusList` availNames avail
614 dfun_names = map getName boot_insts
616 local_export_env :: NameEnv AvailInfo
617 local_export_env = availsToNameEnv local_exports
619 check_inst :: Instance -> TcM (Maybe (Id, Id))
620 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
622 = case [dfun | inst <- local_insts,
623 let dfun = instanceDFunId inst,
624 idType dfun `tcEqType` boot_inst_ty ] of
625 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
626 (dfun:_) -> return (Just (local_boot_dfun, dfun))
628 boot_dfun = instanceDFunId boot_inst
629 boot_inst_ty = idType boot_dfun
630 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
633 -- This has to compare the TyThing from the .hi-boot file to the TyThing
634 -- in the current source file. We must be careful to allow alpha-renaming
635 -- where appropriate, and also the boot declaration is allowed to omit
636 -- constructors and class methods.
638 -- See rnfail055 for a good test of this stuff.
640 checkBootDecl :: TyThing -> TyThing -> Bool
642 checkBootDecl (AnId id1) (AnId id2)
644 (idType id1 `tcEqType` idType id2)
646 checkBootDecl (ATyCon tc1) (ATyCon tc2)
647 = checkBootTyCon tc1 tc2
649 checkBootDecl (AClass c1) (AClass c2)
651 (clas_tyvars1, clas_fds1, sc_theta1, _, ats1, op_stuff1)
652 = classExtraBigSig c1
653 (clas_tyvars2, clas_fds2, sc_theta2, _, ats2, op_stuff2)
654 = classExtraBigSig c2
656 env0 = mkRnEnv2 emptyInScopeSet
657 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
659 eqSig (id1, def_meth1) (id2, def_meth2)
660 = idName id1 == idName id2 &&
661 tcEqTypeX env op_ty1 op_ty2
663 (_, rho_ty1) = splitForAllTys (idType id1)
664 op_ty1 = funResultTy rho_ty1
665 (_, rho_ty2) = splitForAllTys (idType id2)
666 op_ty2 = funResultTy rho_ty2
668 eqFD (as1,bs1) (as2,bs2) =
669 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
670 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
672 same_kind tv1 tv2 = eqKind (tyVarKind tv1) (tyVarKind tv2)
674 eqListBy same_kind clas_tyvars1 clas_tyvars2 &&
675 -- Checks kind of class
676 eqListBy eqFD clas_fds1 clas_fds2 &&
677 (null sc_theta1 && null op_stuff1 && null ats1
678 || -- Above tests for an "abstract" class
679 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
680 eqListBy eqSig op_stuff1 op_stuff2 &&
681 eqListBy checkBootTyCon ats1 ats2)
683 checkBootDecl (ADataCon dc1) (ADataCon dc2)
684 = pprPanic "checkBootDecl" (ppr dc1)
686 checkBootDecl _ _ = False -- probably shouldn't happen
689 checkBootTyCon :: TyCon -> TyCon -> Bool
690 checkBootTyCon tc1 tc2
691 | not (eqKind (tyConKind tc1) (tyConKind tc2))
692 = False -- First off, check the kind
694 | isSynTyCon tc1 && isSynTyCon tc2
696 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
697 env = rnBndrs2 env0 tvs1 tvs2
699 eqSynRhs (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
700 = tcEqTypeX env k1 k2
701 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
702 = tcEqTypeX env t1 t2
704 equalLength tvs1 tvs2 &&
705 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
707 | isAlgTyCon tc1 && isAlgTyCon tc2
709 eqKind (tyConKind tc1) (tyConKind tc2) &&
710 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2) &&
711 eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
713 | isForeignTyCon tc1 && isForeignTyCon tc2
714 = eqKind (tyConKind tc1) (tyConKind tc2) &&
715 tyConExtName tc1 == tyConExtName tc2
717 env0 = mkRnEnv2 emptyInScopeSet
719 eqAlgRhs AbstractTyCon _ = True
720 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
721 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
722 eqListBy eqCon (data_cons tc1) (data_cons tc2)
723 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
724 eqCon (data_con tc1) (data_con tc2)
728 = dataConName c1 == dataConName c2
729 && dataConIsInfix c1 == dataConIsInfix c2
730 && dataConStrictMarks c1 == dataConStrictMarks c2
731 && dataConFieldLabels c1 == dataConFieldLabels c2
732 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
733 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
734 env = rnBndrs2 env0 tvs1 tvs2
736 equalLength tvs1 tvs2 &&
737 eqListBy (tcEqPredX env)
738 (dataConEqTheta c1 ++ dataConDictTheta c1)
739 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
740 eqListBy (tcEqTypeX env)
741 (dataConOrigArgTys c1)
742 (dataConOrigArgTys c2)
745 missingBootThing thing what
746 = ppr thing <+> ptext (sLit "is exported by the hs-boot file, but not")
747 <+> text what <+> ptext (sLit "the module")
749 bootMisMatch thing boot_decl real_decl
750 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
751 ptext (sLit "Main module:") <+> ppr real_decl,
752 ptext (sLit "Boot file: ") <+> ppr boot_decl]
756 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
760 %************************************************************************
762 Type-checking the top level of a module
764 %************************************************************************
766 tcRnGroup takes a bunch of top-level source-code declarations, and
768 * gets supporting declarations from interface files
771 * and augments the TcGblEnv with the results
773 In Template Haskell it may be called repeatedly for each group of
774 declarations. It expects there to be an incoming TcGblEnv in the
775 monad; it augments it and returns the new TcGblEnv.
778 ------------------------------------------------
779 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
780 -- Fails if there are any errors
782 = do { -- Rename the source decls
783 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
785 -- save the renamed syntax, if we want it
787 | Just grp <- tcg_rn_decls tcg_env
788 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
792 -- Dump trace of renaming part
793 rnDump (ppr rn_decls) ;
795 return (tcg_env', rn_decls)
798 ------------------------------------------------
799 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
800 tcTopSrcDecls boot_details
801 (HsGroup { hs_tyclds = tycl_decls,
802 hs_instds = inst_decls,
803 hs_derivds = deriv_decls,
804 hs_fords = foreign_decls,
805 hs_defds = default_decls,
806 hs_annds = annotation_decls,
807 hs_ruleds = rule_decls,
808 hs_valds = val_binds })
809 = do { -- Type-check the type and class decls, and all imported decls
810 -- The latter come in via tycl_decls
811 traceTc (text "Tc2") ;
813 (tcg_env, aux_binds) <- tcTyAndClassDecls boot_details tycl_decls ;
814 -- If there are any errors, tcTyAndClassDecls fails here
816 setGblEnv tcg_env $ do {
817 -- Source-language instances, including derivings,
818 -- and import the supporting declarations
819 traceTc (text "Tc3") ;
820 (tcg_env, inst_infos, deriv_binds)
821 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
822 setGblEnv tcg_env $ do {
824 -- Foreign import declarations next.
825 traceTc (text "Tc4") ;
826 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
827 tcExtendGlobalValEnv fi_ids $ do {
829 -- Default declarations
830 traceTc (text "Tc4a") ;
831 default_tys <- tcDefaults default_decls ;
832 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
834 -- Now GHC-generated derived bindings, generics, and selectors
835 -- Do not generate warnings from compiler-generated code;
836 -- hence the use of discardWarnings
837 (tc_aux_binds, tcl_env) <- discardWarnings (tcTopBinds aux_binds) ;
838 (tc_deriv_binds, tcl_env) <- setLclTypeEnv tcl_env $
839 discardWarnings (tcTopBinds deriv_binds) ;
841 -- Value declarations next
842 traceTc (text "Tc5") ;
843 (tc_val_binds, tcl_env) <- setLclTypeEnv tcl_env $
844 tcTopBinds val_binds;
846 -- Second pass over class and instance declarations,
847 traceTc (text "Tc6") ;
848 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $
849 tcInstDecls2 tycl_decls inst_infos ;
850 showLIE (text "after instDecls2") ;
852 setLclTypeEnv tcl_env $ do { -- Environment doesn't change now
855 traceTc (text "Tc7") ;
856 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
859 annotations <- tcAnnotations annotation_decls ;
862 rules <- tcRules rule_decls ;
865 traceTc (text "Tc7a") ;
866 tcg_env <- getGblEnv ;
867 let { all_binds = tc_val_binds `unionBags`
868 tc_deriv_binds `unionBags`
869 tc_aux_binds `unionBags`
870 inst_binds `unionBags`
873 -- Extend the GblEnv with the (as yet un-zonked)
874 -- bindings, rules, foreign decls
875 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
876 tcg_rules = tcg_rules tcg_env ++ rules,
877 tcg_anns = tcg_anns tcg_env ++ annotations,
878 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
879 return (tcg_env', tcl_env)
884 %************************************************************************
888 %************************************************************************
891 checkMain :: TcM TcGblEnv
892 -- If we are in module Main, check that 'main' is defined.
894 = do { tcg_env <- getGblEnv ;
896 check_main dflags tcg_env
899 check_main dflags tcg_env
901 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
905 = do { mb_main <- lookupGlobalOccRn_maybe main_fn
906 -- Check that 'main' is in scope
907 -- It might be imported from another module!
909 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
914 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
915 ; let loc = srcLocSpan (getSrcLoc main_name)
916 ; ioTyCon <- tcLookupTyCon ioTyConName
917 ; (main_expr, res_ty)
918 <- addErrCtxt mainCtxt $
919 withBox liftedTypeKind $ \res_ty ->
920 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
922 -- See Note [Root-main Id]
923 -- Construct the binding
924 -- :Main.main :: IO res_ty = runMainIO res_ty main
925 ; run_main_id <- tcLookupId runMainIOName
926 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
927 (mkVarOccFS (fsLit "main"))
928 (getSrcSpan main_name)
929 ; root_main_id = Id.mkExportedLocalId root_main_name
930 (mkTyConApp ioTyCon [res_ty])
931 ; co = mkWpTyApps [res_ty]
932 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
933 ; main_bind = noLoc (VarBind root_main_id rhs) }
935 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
937 tcg_dus = tcg_dus tcg_env
938 `plusDU` usesOnly (unitFV main_name)
939 -- Record the use of 'main', so that we don't
940 -- complain about it being defined but not used
944 mod = tcg_mod tcg_env
945 main_mod = mainModIs dflags
946 main_fn = getMainFun dflags
948 complain_no_main | ghcLink dflags == LinkInMemory = return ()
949 | otherwise = failWithTc noMainMsg
950 -- In interactive mode, don't worry about the absence of 'main'
951 -- In other modes, fail altogether, so that we don't go on
952 -- and complain a second time when processing the export list.
954 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
955 noMainMsg = ptext (sLit "The") <+> pp_main_fn
956 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
957 pp_main_fn | main_fn == main_RDR_Unqual = ptext (sLit "function") <+> quotes (ppr main_fn)
958 | otherwise = ptext (sLit "main function") <+> quotes (ppr main_fn)
960 -- | Get the unqualified name of the function to use as the \"main\" for the main module.
961 -- Either returns the default name or the one configured on the command line with -main-is
962 getMainFun :: DynFlags -> RdrName
963 getMainFun dflags = case (mainFunIs dflags) of
964 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
965 Nothing -> main_RDR_Unqual
970 The function that the RTS invokes is always :Main.main, which we call
971 root_main_id. (Because GHC allows the user to have a module not
972 called Main as the main module, we can't rely on the main function
973 being called "Main.main". That's why root_main_id has a fixed module
976 This is unusual: it's a LocalId whose Name has a Module from another
977 module. Tiresomely, we must filter it out again in MkIface, les we
978 get two defns for 'main' in the interface file!
981 %*********************************************************
985 %*********************************************************
989 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
990 setInteractiveContext hsc_env icxt thing_inside
991 = let -- Initialise the tcg_inst_env with instances from all home modules.
992 -- This mimics the more selective call to hptInstances in tcRnModule.
993 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
995 updGblEnv (\env -> env {
996 tcg_rdr_env = ic_rn_gbl_env icxt,
997 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
998 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
1002 tcExtendGhciEnv (ic_tmp_ids icxt) $
1003 -- tcExtendGhciEnv does lots:
1004 -- - it extends the local type env (tcl_env) with the given Ids,
1005 -- - it extends the local rdr env (tcl_rdr) with the Names from
1007 -- - it adds the free tyvars of the Ids to the tcl_tyvars
1010 -- later ids in ic_tmp_ids must shadow earlier ones with the same
1011 -- OccName, and tcExtendIdEnv implements this behaviour.
1013 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
1020 -> InteractiveContext
1022 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1023 -- The returned [Id] is the list of new Ids bound by
1024 -- this statement. It can be used to extend the
1025 -- InteractiveContext via extendInteractiveContext.
1027 -- The returned TypecheckedHsExpr is of type IO [ () ],
1028 -- a list of the bound values, coerced to ().
1030 tcRnStmt hsc_env ictxt rdr_stmt
1031 = initTcPrintErrors hsc_env iNTERACTIVE $
1032 setInteractiveContext hsc_env ictxt $ do {
1034 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1035 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
1036 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1038 rnDump (ppr rn_stmt) ;
1040 -- The real work is done here
1041 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1042 zonked_expr <- zonkTopLExpr tc_expr ;
1043 zonked_ids <- zonkTopBndrs bound_ids ;
1045 -- None of the Ids should be of unboxed type, because we
1046 -- cast them all to HValues in the end!
1047 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1049 traceTc (text "tcs 1") ;
1050 let { global_ids = map globaliseAndTidyId zonked_ids } ;
1051 -- Note [Interactively-bound Ids in GHCi]
1053 {- ---------------------------------------------
1054 At one stage I removed any shadowed bindings from the type_env;
1055 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1056 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1058 Prelude> let f n = n * 2 :: Int
1059 Prelude> fName <- runQ [| f |]
1060 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1062 Prelude> let f n = n * 3 :: Int
1063 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1064 In the last line we use 'fName', which resolves to the *first* 'f'
1065 in scope. If we delete it from the type env, GHCi crashes because
1066 it doesn't expect that.
1068 Hence this code is commented out
1070 -------------------------------------------------- -}
1072 dumpOptTcRn Opt_D_dump_tc
1073 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1074 text "Typechecked expr" <+> ppr zonked_expr]) ;
1076 return (global_ids, zonked_expr)
1079 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1080 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1083 Note [Interactively-bound Ids in GHCi]
1084 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1085 The Ids bound by previous Stmts in Template Haskell are currently
1087 b) with an Internal Name (not External)
1088 c) and a tidied type
1090 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1091 compile an expression using these ids later, the byte code
1092 generator will consider the occurrences to be free rather than
1095 (b) They retain their Internal names becuase we don't have a suitable
1096 Module to name them with. We could revisit this choice.
1098 (c) Their types are tidied. This is important, because :info may ask
1099 to look at them, and :info expects the things it looks up to have
1103 --------------------------------------------------------------------------
1104 Typechecking Stmts in GHCi
1106 Here is the grand plan, implemented in tcUserStmt
1108 What you type The IO [HValue] that hscStmt returns
1109 ------------- ------------------------------------
1110 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1113 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1116 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1117 [NB: result not printed] bindings: [it]
1119 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1120 result showable) bindings: [it]
1122 expr (of non-IO type,
1123 result not showable) ==> error
1127 ---------------------------
1128 type PlanResult = ([Id], LHsExpr Id)
1129 type Plan = TcM PlanResult
1131 runPlans :: [Plan] -> TcM PlanResult
1132 -- Try the plans in order. If one fails (by raising an exn), try the next.
1133 -- If one succeeds, take it.
1134 runPlans [] = panic "runPlans"
1136 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1138 --------------------
1139 mkPlan :: LStmt Name -> TcM PlanResult
1140 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1141 = do { uniq <- newUnique -- is treated very specially
1142 ; let fresh_it = itName uniq
1143 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1144 matches = [mkMatch [] expr emptyLocalBinds]
1145 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1146 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1147 (HsVar bindIOName) noSyntaxExpr
1148 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1149 (HsVar thenIOName) placeHolderType
1152 -- [it <- e; print it] but not if it::()
1154 -- [let it = e; print it]
1155 ; runPlans [ -- Plan A
1156 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1157 ; it_ty <- zonkTcType (idType it_id)
1158 ; when (isUnitTy it_ty) failM
1161 -- Plan B; a naked bind statment
1162 tcGhciStmts [bind_stmt],
1164 -- Plan C; check that the let-binding is typeable all by itself.
1165 -- If not, fail; if so, try to print it.
1166 -- The two-step process avoids getting two errors: one from
1167 -- the expression itself, and one from the 'print it' part
1168 -- This two-step story is very clunky, alas
1169 do { checkNoErrs (tcGhciStmts [let_stmt])
1170 --- checkNoErrs defeats the error recovery of let-bindings
1171 ; tcGhciStmts [let_stmt, print_it] }
1174 mkPlan stmt@(L loc (BindStmt {}))
1175 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1176 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1177 (HsVar thenIOName) placeHolderType
1179 ; print_bind_result <- doptM Opt_PrintBindResult
1180 ; let print_plan = do
1181 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1182 ; v_ty <- zonkTcType (idType v_id)
1183 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1187 -- [stmt; print v] but not if v::()
1189 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1190 [tcGhciStmts [stmt]])
1194 = tcGhciStmts [stmt]
1196 ---------------------------
1197 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1199 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1200 ret_id <- tcLookupId returnIOName ; -- return @ IO
1202 ret_ty = mkListTy unitTy ;
1203 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1204 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1206 names = map unLoc (collectLStmtsBinders stmts) ;
1208 -- mk_return builds the expression
1209 -- returnIO @ [()] [coerce () x, .., coerce () z]
1211 -- Despite the inconvenience of building the type applications etc,
1212 -- this *has* to be done in type-annotated post-typecheck form
1213 -- because we are going to return a list of *polymorphic* values
1214 -- coerced to type (). If we built a *source* stmt
1215 -- return [coerce x, ..., coerce z]
1216 -- then the type checker would instantiate x..z, and we wouldn't
1217 -- get their *polymorphic* values. (And we'd get ambiguity errs
1218 -- if they were overloaded, since they aren't applied to anything.)
1219 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1220 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1221 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1225 -- OK, we're ready to typecheck the stmts
1226 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1227 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1228 mapM tcLookupId names ;
1229 -- Look up the names right in the middle,
1230 -- where they will all be in scope
1232 -- Simplify the context
1233 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1234 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1235 -- checkNoErrs ensures that the plan fails if context redn fails
1237 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1238 return (ids, mkHsDictLet const_binds $
1239 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1244 tcRnExpr just finds the type of an expression
1248 -> InteractiveContext
1250 -> IO (Messages, Maybe Type)
1251 tcRnExpr hsc_env ictxt rdr_expr
1252 = initTcPrintErrors hsc_env iNTERACTIVE $
1253 setInteractiveContext hsc_env ictxt $ do {
1255 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1258 -- Now typecheck the expression;
1259 -- it might have a rank-2 type (e.g. :t runST)
1260 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1261 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1262 tcSimplifyInteractive lie_top ;
1264 let { all_expr_ty = mkForAllTys qtvs $
1265 mkFunTys (map (idType . instToId) dict_insts) $
1267 zonkTcType all_expr_ty
1270 smpl_doc = ptext (sLit "main expression")
1273 tcRnType just finds the kind of a type
1277 -> InteractiveContext
1279 -> IO (Messages, Maybe Kind)
1280 tcRnType hsc_env ictxt rdr_type
1281 = initTcPrintErrors hsc_env iNTERACTIVE $
1282 setInteractiveContext hsc_env ictxt $ do {
1284 rn_type <- rnLHsType doc rdr_type ;
1287 -- Now kind-check the type
1288 (ty', kind) <- kcLHsType rn_type ;
1292 doc = ptext (sLit "In GHCi input")
1298 %************************************************************************
1300 More GHCi stuff, to do with browsing and getting info
1302 %************************************************************************
1306 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1307 -- a package module with an interface on disk. If neither of these is
1308 -- true, then the result will be an error indicating the interface
1309 -- could not be found.
1310 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1311 getModuleExports hsc_env mod
1314 checkMods = ic_toplev_scope ic ++ ic_exports ic
1316 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1318 -- Get the export avail info and also load all orphan and family-instance
1319 -- modules. Finally, check that the family instances of all modules in the
1320 -- interactive context are consistent (these modules are in the second
1322 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1323 tcGetModuleExports mod directlyImpMods
1324 = do { let doc = ptext (sLit "context for compiling statements")
1325 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1327 -- Load any orphan-module and family instance-module
1328 -- interfaces, so their instances are visible.
1329 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1330 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1332 -- Check that the family instances of all directly loaded
1333 -- modules are consistent.
1334 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1336 ; ifaceExportNames (mi_exports iface)
1339 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1340 tcRnLookupRdrName hsc_env rdr_name
1341 = initTcPrintErrors hsc_env iNTERACTIVE $
1342 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1343 lookup_rdr_name rdr_name
1345 lookup_rdr_name rdr_name = do {
1346 -- If the identifier is a constructor (begins with an
1347 -- upper-case letter), then we need to consider both
1348 -- constructor and type class identifiers.
1349 let { rdr_names = dataTcOccs rdr_name } ;
1351 -- results :: [Either Messages Name]
1352 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1354 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1355 -- The successful lookups will be (Just name)
1356 let { (warns_s, good_names) = unzip [ (msgs, name)
1357 | (msgs, Just name) <- results] ;
1358 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1360 -- Fail if nothing good happened, else add warnings
1361 if null good_names then
1362 -- No lookup succeeded, so
1363 -- pick the first error message and report it
1364 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1365 -- while the other is "X is not in scope",
1366 -- we definitely want the former; but we might pick the latter
1367 do { addMessages (head errs_s) ; failM }
1368 else -- Add deprecation warnings
1369 mapM_ addMessages warns_s ;
1374 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1375 tcRnLookupName hsc_env name
1376 = initTcPrintErrors hsc_env iNTERACTIVE $
1377 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1378 tcRnLookupName' name
1380 -- To look up a name we have to look in the local environment (tcl_lcl)
1381 -- as well as the global environment, which is what tcLookup does.
1382 -- But we also want a TyThing, so we have to convert:
1384 tcRnLookupName' :: Name -> TcRn TyThing
1385 tcRnLookupName' name = do
1386 tcthing <- tcLookup name
1388 AGlobal thing -> return thing
1389 ATcId{tct_id=id} -> return (AnId id)
1390 _ -> panic "tcRnLookupName'"
1392 tcRnGetInfo :: HscEnv
1394 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1396 -- Used to implemnent :info in GHCi
1398 -- Look up a RdrName and return all the TyThings it might be
1399 -- A capitalised RdrName is given to us in the DataName namespace,
1400 -- but we want to treat it as *both* a data constructor
1401 -- *and* as a type or class constructor;
1402 -- hence the call to dataTcOccs, and we return up to two results
1403 tcRnGetInfo hsc_env name
1404 = initTcPrintErrors hsc_env iNTERACTIVE $
1405 let ictxt = hsc_IC hsc_env in
1406 setInteractiveContext hsc_env ictxt $ do
1408 -- Load the interface for all unqualified types and classes
1409 -- That way we will find all the instance declarations
1410 -- (Packages have not orphan modules, and we assume that
1411 -- in the home package all relevant modules are loaded.)
1412 loadUnqualIfaces ictxt
1414 thing <- tcRnLookupName' name
1415 fixity <- lookupFixityRn name
1416 ispecs <- lookupInsts thing
1417 return (thing, fixity, ispecs)
1419 lookupInsts :: TyThing -> TcM [Instance]
1420 lookupInsts (AClass cls)
1421 = do { inst_envs <- tcGetInstEnvs
1422 ; return (classInstances inst_envs cls) }
1424 lookupInsts (ATyCon tc)
1425 = do { eps <- getEps -- Load all instances for all classes that are
1426 -- in the type environment (which are all the ones
1427 -- we've seen in any interface file so far)
1428 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1430 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1431 , let dfun = instanceDFunId ispec
1434 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1435 tc_name = tyConName tc
1437 lookupInsts other = return []
1439 loadUnqualIfaces :: InteractiveContext -> TcM ()
1440 -- Load the home module for everything that is in scope unqualified
1441 -- This is so that we can accurately report the instances for
1443 loadUnqualIfaces ictxt
1445 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1447 unqual_mods = [ nameModule name
1448 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1449 let name = gre_name gre,
1450 not (isInternalName name),
1451 isTcOcc (nameOccName name), -- Types and classes only
1452 unQualOK gre ] -- In scope unqualified
1453 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1457 %************************************************************************
1461 %************************************************************************
1464 rnDump :: SDoc -> TcRn ()
1465 -- Dump, with a banner, if -ddump-rn
1466 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1468 tcDump :: TcGblEnv -> TcRn ()
1470 = do { dflags <- getDOpts ;
1472 -- Dump short output if -ddump-types or -ddump-tc
1473 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1474 (dumpTcRn short_dump) ;
1476 -- Dump bindings if -ddump-tc
1477 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1480 short_dump = pprTcGblEnv env
1481 full_dump = pprLHsBinds (tcg_binds env)
1482 -- NB: foreign x-d's have undefined's in their types;
1483 -- hence can't show the tc_fords
1486 = do { dflags <- getDOpts ;
1487 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1488 (dumpTcRn (pprModGuts mod_guts)) ;
1490 -- Dump bindings if -ddump-tc
1491 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1493 full_dump = pprCoreBindings (mg_binds mod_guts)
1495 -- It's unpleasant having both pprModGuts and pprModDetails here
1496 pprTcGblEnv :: TcGblEnv -> SDoc
1497 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1499 tcg_fam_insts = fam_insts,
1501 tcg_imports = imports })
1502 = vcat [ ppr_types insts type_env
1503 , ppr_tycons fam_insts type_env
1505 , ppr_fam_insts fam_insts
1506 , vcat (map ppr rules)
1507 , ppr_gen_tycons (typeEnvTyCons type_env)
1508 , ptext (sLit "Dependent modules:") <+>
1509 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1510 , ptext (sLit "Dependent packages:") <+>
1511 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1512 where -- The two uses of sortBy are just to reduce unnecessary
1513 -- wobbling in testsuite output
1514 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1515 = (mod_name1 `stableModuleNameCmp` mod_name2)
1517 (is_boot1 `compare` is_boot2)
1519 pprModGuts :: ModGuts -> SDoc
1520 pprModGuts (ModGuts { mg_types = type_env,
1522 = vcat [ ppr_types [] type_env,
1525 ppr_types :: [Instance] -> TypeEnv -> SDoc
1526 ppr_types insts type_env
1527 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1529 dfun_ids = map instanceDFunId insts
1530 ids = [id | id <- typeEnvIds type_env, want_sig id]
1531 want_sig id | opt_PprStyle_Debug = True
1532 | otherwise = isLocalId id &&
1533 isExternalName (idName id) &&
1534 not (id `elem` dfun_ids)
1535 -- isLocalId ignores data constructors, records selectors etc.
1536 -- The isExternalName ignores local dictionary and method bindings
1537 -- that the type checker has invented. Top-level user-defined things
1538 -- have External names.
1540 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1541 ppr_tycons fam_insts type_env
1542 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1544 fi_tycons = map famInstTyCon fam_insts
1545 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1546 want_tycon tycon | opt_PprStyle_Debug = True
1547 | otherwise = not (isImplicitTyCon tycon) &&
1548 isExternalName (tyConName tycon) &&
1549 not (tycon `elem` fi_tycons)
1551 ppr_insts :: [Instance] -> SDoc
1552 ppr_insts [] = empty
1553 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1555 ppr_fam_insts :: [FamInst] -> SDoc
1556 ppr_fam_insts [] = empty
1557 ppr_fam_insts fam_insts =
1558 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1560 ppr_sigs :: [Var] -> SDoc
1562 -- Print type signatures; sort by OccName
1563 = vcat (map ppr_sig (sortLe le_sig ids))
1565 le_sig id1 id2 = getOccName id1 <= getOccName id2
1566 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1568 ppr_tydecls :: [TyCon] -> SDoc
1570 -- Print type constructor info; sort by OccName
1571 = vcat (map ppr_tycon (sortLe le_sig tycons))
1573 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1575 | isCoercionTyCon tycon = ptext (sLit "coercion") <+> ppr tycon
1576 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1578 ppr_rules :: [CoreRule] -> SDoc
1579 ppr_rules [] = empty
1580 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1581 nest 4 (pprRules rs),
1584 ppr_gen_tycons [] = empty
1585 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1586 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]