2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
5 \section[TcModule]{Typechecking a whole module}
10 tcRnStmt, tcRnExpr, tcRnType,
22 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
50 import TcUnify ( withBox )
75 import Data.List ( sortBy )
86 import TidyPgm ( globaliseAndTidyId )
87 import TcType ( isUnitTy, isTauTy, tyClsNamesOfDFunHead )
88 import TysWiredIn ( unitTy, mkListTy )
98 #include "HsVersions.h"
101 %************************************************************************
103 Typecheck and rename a module
105 %************************************************************************
111 -> Bool -- True <=> save renamed syntax
112 -> Located (HsModule RdrName)
113 -> IO (Messages, Maybe TcGblEnv)
115 tcRnModule hsc_env hsc_src save_rn_syntax
116 (L loc (HsModule maybe_mod export_ies
117 import_decls local_decls mod_deprec
119 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
121 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
122 this_mod = case maybe_mod of
123 Nothing -> mAIN -- 'module M where' is omitted
124 Just (L _ mod) -> mkModule this_pkg mod } ;
127 initTc hsc_env hsc_src save_rn_syntax this_mod $
129 do { -- Deal with imports;
130 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
131 setGblEnv tcg_env $ do {
133 -- Load the hi-boot interface for this module, if any
134 -- We do this now so that the boot_names can be passed
135 -- to tcTyAndClassDecls, because the boot_names are
136 -- automatically considered to be loop breakers
138 -- Do this *after* tcRnImports, so that we know whether
139 -- a module that we import imports us; and hence whether to
140 -- look for a hi-boot file
141 boot_iface <- tcHiBootIface hsc_src this_mod ;
143 -- Rename and type check the declarations
144 traceRn (text "rn1a") ;
145 tcg_env <- if isHsBoot hsc_src then
146 tcRnHsBootDecls local_decls
148 tcRnSrcDecls boot_iface local_decls ;
149 setGblEnv tcg_env $ do {
151 -- Report the use of any deprecated things
152 -- We do this *before* processsing the export list so
153 -- that we don't bleat about re-exporting a deprecated
154 -- thing (especially via 'module Foo' export item)
155 -- That is, only uses in the *body* of the module are complained about
156 traceRn (text "rn3") ;
157 failIfErrsM ; -- finishWarnings crashes sometimes
158 -- as a result of typechecker repairs (e.g. unboundNames)
159 tcg_env <- finishWarnings (hsc_dflags hsc_env) mod_deprec tcg_env ;
161 -- Process the export list
162 traceRn (text "rn4a: before exports");
163 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
164 traceRn (text "rn4b: after exportss") ;
166 -- Check that main is exported (must be after rnExports)
167 checkMainExported tcg_env ;
169 -- Compare the hi-boot iface (if any) with the real thing
170 -- Must be done after processing the exports
171 tcg_env <- checkHiBootIface tcg_env boot_iface ;
173 -- The new type env is already available to stuff slurped from
174 -- interface files, via TcEnv.updateGlobalTypeEnv
175 -- It's important that this includes the stuff in checkHiBootIface,
176 -- because the latter might add new bindings for boot_dfuns,
177 -- which may be mentioned in imported unfoldings
179 -- Don't need to rename the Haddock documentation,
180 -- it's not parsed by GHC anymore.
181 tcg_env <- return (tcg_env { tcg_doc_hdr = maybe_doc_hdr }) ;
183 -- Report unused names
184 reportUnusedNames export_ies tcg_env ;
186 -- Dump output and return
193 %************************************************************************
197 %************************************************************************
200 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
201 tcRnImports hsc_env this_mod import_decls
202 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
204 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
205 ; dep_mods = imp_dep_mods imports
207 -- We want instance declarations from all home-package
208 -- modules below this one, including boot modules, except
209 -- ourselves. The 'except ourselves' is so that we don't
210 -- get the instances from this module's hs-boot file
211 ; want_instances :: ModuleName -> Bool
212 ; want_instances mod = mod `elemUFM` dep_mods
213 && mod /= moduleName this_mod
214 ; (home_insts, home_fam_insts) = hptInstances hsc_env
218 -- Record boot-file info in the EPS, so that it's
219 -- visible to loadHiBootInterface in tcRnSrcDecls,
220 -- and any other incrementally-performed imports
221 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
223 -- Update the gbl env
224 ; updGblEnv ( \ gbl ->
226 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
227 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
228 tcg_rn_imports = rn_imports,
229 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
230 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
235 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
236 -- Fail if there are any errors so far
237 -- The error printing (if needed) takes advantage
238 -- of the tcg_env we have now set
239 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
242 -- Load any orphan-module and family instance-module
243 -- interfaces, so that their rules and instance decls will be
245 ; loadOrphanModules (imp_orphs imports) False
246 ; loadOrphanModules (imp_finsts imports) True
248 -- Check type-familily consistency
249 ; traceRn (text "rn1: checking family instance consistency")
250 ; let { dir_imp_mods = moduleEnvKeys
253 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
259 %************************************************************************
261 Type-checking external-core modules
263 %************************************************************************
266 tcRnExtCore :: HscEnv
268 -> IO (Messages, Maybe ModGuts)
269 -- Nothing => some error occurred
271 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
272 -- The decls are IfaceDecls; all names are original names
273 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
275 initTc hsc_env ExtCoreFile False this_mod $ do {
277 let { ldecls = map noLoc decls } ;
279 -- bring the type and class decls into scope
280 -- ToDo: check that this doesn't need to extract the val binds.
281 -- It seems that only the type and class decls need to be in scope below because
282 -- (a) tcTyAndClassDecls doesn't need the val binds, and
283 -- (b) tcExtCoreBindings doesn't need anything
284 -- (in fact, it might not even need to be in the scope of
285 -- this tcg_env at all)
286 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
287 tc_envs <- extendGlobalRdrEnvRn avails emptyFsEnv {- no fixity decls -} ;
289 setEnvs tc_envs $ do {
291 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
293 -- Dump trace of renaming part
294 rnDump (ppr rn_decls) ;
296 -- Typecheck them all together so that
297 -- any mutually recursive types are done right
298 -- Just discard the auxiliary bindings; they are generated
299 -- only for Haskell source code, and should already be in Core
300 (tcg_env, _aux_binds) <- tcTyAndClassDecls emptyModDetails rn_decls ;
302 setGblEnv tcg_env $ do {
303 -- Make the new type env available to stuff slurped from interface files
305 -- Now the core bindings
306 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
310 bndrs = bindersOfBinds core_binds ;
311 my_exports = map (Avail . idName) bndrs ;
312 -- ToDo: export the data types also?
315 extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
317 mod_guts = ModGuts { mg_module = this_mod,
319 mg_used_names = emptyNameSet, -- ToDo: compute usage
320 mg_dir_imps = emptyModuleEnv, -- ??
321 mg_deps = noDependencies, -- ??
322 mg_exports = my_exports,
323 mg_types = final_type_env,
324 mg_insts = tcg_insts tcg_env,
325 mg_fam_insts = tcg_fam_insts tcg_env,
326 mg_inst_env = tcg_inst_env tcg_env,
327 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
330 mg_binds = core_binds,
333 mg_rdr_env = emptyGlobalRdrEnv,
334 mg_fix_env = emptyFixityEnv,
335 mg_warns = NoWarnings,
336 mg_foreign = NoStubs,
337 mg_hpc_info = emptyHpcInfo False,
338 mg_modBreaks = emptyModBreaks,
339 mg_vect_info = noVectInfo
342 tcCoreDump mod_guts ;
347 mkFakeGroup :: [LTyClDecl a] -> HsGroup a
348 mkFakeGroup decls -- Rather clumsy; lots of unused fields
349 = emptyRdrGroup { hs_tyclds = decls }
353 %************************************************************************
355 Type-checking the top level of a module
357 %************************************************************************
360 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
361 -- Returns the variables free in the decls
362 -- Reason: solely to report unused imports and bindings
363 tcRnSrcDecls boot_iface decls
364 = do { -- Do all the declarations
365 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
367 -- Finish simplifying class constraints
369 -- tcSimplifyTop deals with constant or ambiguous InstIds.
370 -- How could there be ambiguous ones? They can only arise if a
371 -- top-level decl falls under the monomorphism restriction
372 -- and no subsequent decl instantiates its type.
374 -- We do this after checkMain, so that we use the type info
375 -- thaat checkMain adds
377 -- We do it with both global and local env in scope:
378 -- * the global env exposes the instances to tcSimplifyTop
379 -- * the local env exposes the local Ids to tcSimplifyTop,
380 -- so that we get better error messages (monomorphism restriction)
381 traceTc (text "Tc8") ;
382 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
384 -- Backsubstitution. This must be done last.
385 -- Even tcSimplifyTop may do some unification.
386 traceTc (text "Tc9") ;
387 let { (tcg_env, _) = tc_envs
388 ; TcGblEnv { tcg_type_env = type_env,
391 tcg_fords = fords } = tcg_env
392 ; all_binds = binds `unionBags` inst_binds } ;
394 failIfErrsM ; -- Don't zonk if there have been errors
395 -- It's a waste of time; and we may get debug warnings
396 -- about strangely-typed TyCons!
398 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
401 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
402 ; tcg_env' = tcg_env { tcg_binds = binds',
404 tcg_fords = fords' } } ;
406 setGlobalTypeEnv tcg_env' final_type_env
409 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
410 -- Loops around dealing with each top level inter-splice group
411 -- in turn, until it's dealt with the entire module
412 tc_rn_src_decls boot_details ds
413 = do { (first_group, group_tail) <- findSplice ds ;
414 -- If ds is [] we get ([], Nothing)
416 -- Deal with decls up to, but not including, the first splice
417 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
418 -- rnTopSrcDecls fails if there are any errors
420 (tcg_env, tcl_env) <- setGblEnv tcg_env $
421 tcTopSrcDecls boot_details rn_decls ;
423 -- If there is no splice, we're nearly done
424 setEnvs (tcg_env, tcl_env) $
426 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
427 return (tcg_env, tcl_env)
431 -- There shouldn't be a splice
432 Just (SpliceDecl {}, _) -> do {
433 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
435 -- If there's a splice, we must carry on
436 Just (SpliceDecl splice_expr _, rest_ds) -> do {
438 -- Rename the splice expression, and get its supporting decls
439 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
440 -- checkNoErrs: don't typecheck if renaming failed
441 rnDump (ppr rn_splice_expr) ;
443 -- Execute the splice
444 spliced_decls <- tcSpliceDecls rn_splice_expr ;
446 -- Glue them on the front of the remaining decls and loop
447 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
448 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
453 %************************************************************************
455 Compiling hs-boot source files, and
456 comparing the hi-boot interface with the real thing
458 %************************************************************************
461 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
462 tcRnHsBootDecls decls
463 = do { (first_group, group_tail) <- findSplice decls
465 -- Rename the declarations
466 ; (tcg_env, HsGroup {
467 hs_tyclds = tycl_decls,
468 hs_instds = inst_decls,
469 hs_derivds = deriv_decls,
470 hs_fords = for_decls,
471 hs_defds = def_decls,
472 hs_ruleds = rule_decls,
474 hs_valds = val_binds }) <- rnTopSrcDecls first_group
475 ; setGblEnv tcg_env $ do {
478 -- Check for illegal declarations
480 Just (SpliceDecl d _, _) -> badBootDecl "splice" d
482 ; mapM_ (badBootDecl "foreign") for_decls
483 ; mapM_ (badBootDecl "default") def_decls
484 ; mapM_ (badBootDecl "rule") rule_decls
486 -- Typecheck type/class decls
487 ; traceTc (text "Tc2")
488 ; (tcg_env, aux_binds) <- tcTyAndClassDecls emptyModDetails tycl_decls
489 ; setGblEnv tcg_env $ do {
491 -- Typecheck instance decls
492 -- Family instance declarations are rejected here
493 ; traceTc (text "Tc3")
494 ; (tcg_env, inst_infos, _deriv_binds)
495 <- tcInstDecls1 tycl_decls inst_decls deriv_decls
496 ; setGblEnv tcg_env $ do {
498 -- Typecheck value declarations
499 ; traceTc (text "Tc5")
500 ; val_ids <- tcHsBootSigs val_binds
503 -- No simplification or zonking to do
504 ; traceTc (text "Tc7a")
505 ; gbl_env <- getGblEnv
507 -- Make the final type-env
508 -- Include the dfun_ids so that their type sigs
509 -- are written into the interface file.
510 -- And similarly the aux_ids from aux_binds
511 ; let { type_env0 = tcg_type_env gbl_env
512 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
513 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
514 ; type_env3 = extendTypeEnvWithIds type_env2 aux_ids
515 ; dfun_ids = map iDFunId inst_infos
516 ; aux_ids = case aux_binds of
517 ValBindsOut _ sigs -> [id | L _ (IdSig id) <- sigs]
518 _ -> panic "tcRnHsBoodDecls"
521 ; setGlobalTypeEnv gbl_env type_env3
524 badBootDecl :: String -> Located decl -> TcM ()
525 badBootDecl what (L loc _)
526 = addErrAt loc (char 'A' <+> text what
527 <+> ptext (sLit "declaration is not (currently) allowed in a hs-boot file"))
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,
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 dfun_prs = catMaybes mb_dfun_prs
570 boot_dfuns = map fst dfun_prs
571 dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun)
572 | (boot_dfun, dfun) <- dfun_prs ]
573 type_env' = extendTypeEnvWithIds local_type_env boot_dfuns
574 tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
577 ; setGlobalTypeEnv tcg_env' type_env' }
578 -- Update the global type env *including* the knot-tied one
579 -- so that if the source module reads in an interface unfolding
580 -- mentioning one of the dfuns from the boot module, then it
581 -- can "see" that boot dfun. See Trac #4003
583 check_export boot_avail -- boot_avail is exported by the boot iface
584 | name `elem` dfun_names = return ()
585 | isWiredInName name = return () -- No checking for wired-in names. In particular,
586 -- 'error' is handled by a rather gross hack
587 -- (see comments in GHC.Err.hs-boot)
589 -- Check that the actual module exports the same thing
590 | not (null missing_names)
591 = addErrAt (nameSrcSpan (head missing_names))
592 (missingBootThing (head missing_names) "exported by")
594 -- If the boot module does not *define* the thing, we are done
595 -- (it simply re-exports it, and names match, so nothing further to do)
596 | isNothing mb_boot_thing = return ()
598 -- Check that the actual module also defines the thing, and
599 -- then compare the definitions
600 | Just real_thing <- lookupTypeEnv local_type_env name,
601 Just boot_thing <- mb_boot_thing
602 = when (not (checkBootDecl boot_thing real_thing))
603 $ addErrAt (nameSrcSpan (getName boot_thing))
604 (let boot_decl = tyThingToIfaceDecl
605 (fromJust mb_boot_thing)
606 real_decl = tyThingToIfaceDecl real_thing
607 in bootMisMatch real_thing boot_decl real_decl)
610 = addErrTc (missingBootThing name "defined in")
612 name = availName boot_avail
613 mb_boot_thing = lookupTypeEnv boot_type_env name
614 missing_names = case lookupNameEnv local_export_env name of
616 Just avail -> availNames boot_avail `minusList` availNames avail
618 dfun_names = map getName boot_insts
620 local_export_env :: NameEnv AvailInfo
621 local_export_env = availsToNameEnv local_exports
623 check_inst :: Instance -> TcM (Maybe (Id, Id))
624 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
626 = case [dfun | inst <- local_insts,
627 let dfun = instanceDFunId inst,
628 idType dfun `tcEqType` boot_inst_ty ] of
629 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
630 (dfun:_) -> return (Just (local_boot_dfun, dfun))
632 boot_dfun = instanceDFunId boot_inst
633 boot_inst_ty = idType boot_dfun
634 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
637 -- This has to compare the TyThing from the .hi-boot file to the TyThing
638 -- in the current source file. We must be careful to allow alpha-renaming
639 -- where appropriate, and also the boot declaration is allowed to omit
640 -- constructors and class methods.
642 -- See rnfail055 for a good test of this stuff.
644 checkBootDecl :: TyThing -> TyThing -> Bool
646 checkBootDecl (AnId id1) (AnId id2)
648 (idType id1 `tcEqType` idType id2)
650 checkBootDecl (ATyCon tc1) (ATyCon tc2)
651 = checkBootTyCon tc1 tc2
653 checkBootDecl (AClass c1) (AClass c2)
655 (clas_tyvars1, clas_fds1, sc_theta1, _, ats1, op_stuff1)
656 = classExtraBigSig c1
657 (clas_tyvars2, clas_fds2, sc_theta2, _, ats2, op_stuff2)
658 = classExtraBigSig c2
660 env0 = mkRnEnv2 emptyInScopeSet
661 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
663 eqSig (id1, def_meth1) (id2, def_meth2)
664 = idName id1 == idName id2 &&
665 tcEqTypeX env op_ty1 op_ty2 &&
666 def_meth1 == def_meth2
668 (_, rho_ty1) = splitForAllTys (idType id1)
669 op_ty1 = funResultTy rho_ty1
670 (_, rho_ty2) = splitForAllTys (idType id2)
671 op_ty2 = funResultTy rho_ty2
673 eqFD (as1,bs1) (as2,bs2) =
674 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
675 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
677 same_kind tv1 tv2 = eqKind (tyVarKind tv1) (tyVarKind tv2)
679 eqListBy same_kind clas_tyvars1 clas_tyvars2 &&
680 -- Checks kind of class
681 eqListBy eqFD clas_fds1 clas_fds2 &&
682 (null sc_theta1 && null op_stuff1 && null ats1
683 || -- Above tests for an "abstract" class
684 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
685 eqListBy eqSig op_stuff1 op_stuff2 &&
686 eqListBy checkBootTyCon ats1 ats2)
688 checkBootDecl (ADataCon dc1) (ADataCon _)
689 = pprPanic "checkBootDecl" (ppr dc1)
691 checkBootDecl _ _ = False -- probably shouldn't happen
694 checkBootTyCon :: TyCon -> TyCon -> Bool
695 checkBootTyCon tc1 tc2
696 | not (eqKind (tyConKind tc1) (tyConKind tc2))
697 = False -- First off, check the kind
699 | isSynTyCon tc1 && isSynTyCon tc2
701 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
702 env = rnBndrs2 env0 tvs1 tvs2
704 eqSynRhs (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
705 = tcEqTypeX env k1 k2
706 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
707 = tcEqTypeX env t1 t2
710 equalLength tvs1 tvs2 &&
711 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
713 | isAlgTyCon tc1 && isAlgTyCon tc2
715 eqKind (tyConKind tc1) (tyConKind tc2) &&
716 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2) &&
717 eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
719 | isForeignTyCon tc1 && isForeignTyCon tc2
720 = eqKind (tyConKind tc1) (tyConKind tc2) &&
721 tyConExtName tc1 == tyConExtName tc2
725 env0 = mkRnEnv2 emptyInScopeSet
727 eqAlgRhs AbstractTyCon _ = True
728 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
729 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
730 eqListBy eqCon (data_cons tc1) (data_cons tc2)
731 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
732 eqCon (data_con tc1) (data_con tc2)
736 = dataConName c1 == dataConName c2
737 && dataConIsInfix c1 == dataConIsInfix c2
738 && dataConStrictMarks c1 == dataConStrictMarks c2
739 && dataConFieldLabels c1 == dataConFieldLabels c2
740 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
741 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
742 env = rnBndrs2 env0 tvs1 tvs2
744 equalLength tvs1 tvs2 &&
745 eqListBy (tcEqPredX env)
746 (dataConEqTheta c1 ++ dataConDictTheta c1)
747 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
748 eqListBy (tcEqTypeX env)
749 (dataConOrigArgTys c1)
750 (dataConOrigArgTys c2)
753 missingBootThing :: Name -> String -> SDoc
754 missingBootThing name what
755 = ppr name <+> ptext (sLit "is exported by the hs-boot file, but not")
756 <+> text what <+> ptext (sLit "the module")
758 bootMisMatch :: TyThing -> IfaceDecl -> IfaceDecl -> SDoc
759 bootMisMatch thing boot_decl real_decl
760 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
761 ptext (sLit "Main module:") <+> ppr real_decl,
762 ptext (sLit "Boot file: ") <+> ppr boot_decl]
764 instMisMatch :: Instance -> SDoc
767 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
771 %************************************************************************
773 Type-checking the top level of a module
775 %************************************************************************
777 tcRnGroup takes a bunch of top-level source-code declarations, and
779 * gets supporting declarations from interface files
782 * and augments the TcGblEnv with the results
784 In Template Haskell it may be called repeatedly for each group of
785 declarations. It expects there to be an incoming TcGblEnv in the
786 monad; it augments it and returns the new TcGblEnv.
789 ------------------------------------------------
790 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
791 -- Fails if there are any errors
793 = do { -- Rename the source decls
794 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
796 -- save the renamed syntax, if we want it
798 | Just grp <- tcg_rn_decls tcg_env
799 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
803 -- Dump trace of renaming part
804 rnDump (ppr rn_decls) ;
806 return (tcg_env', rn_decls)
809 ------------------------------------------------
810 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
811 tcTopSrcDecls boot_details
812 (HsGroup { hs_tyclds = tycl_decls,
813 hs_instds = inst_decls,
814 hs_derivds = deriv_decls,
815 hs_fords = foreign_decls,
816 hs_defds = default_decls,
817 hs_annds = annotation_decls,
818 hs_ruleds = rule_decls,
819 hs_valds = val_binds })
820 = do { -- Type-check the type and class decls, and all imported decls
821 -- The latter come in via tycl_decls
822 traceTc (text "Tc2") ;
824 (tcg_env, aux_binds) <- tcTyAndClassDecls boot_details tycl_decls ;
825 -- If there are any errors, tcTyAndClassDecls fails here
827 setGblEnv tcg_env $ do {
828 -- Source-language instances, including derivings,
829 -- and import the supporting declarations
830 traceTc (text "Tc3") ;
831 (tcg_env, inst_infos, deriv_binds)
832 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
833 setGblEnv tcg_env $ do {
835 -- Foreign import declarations next.
836 traceTc (text "Tc4") ;
837 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
838 tcExtendGlobalValEnv fi_ids $ do {
840 -- Default declarations
841 traceTc (text "Tc4a") ;
842 default_tys <- tcDefaults default_decls ;
843 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
845 -- Now GHC-generated derived bindings, generics, and selectors
846 -- Do not generate warnings from compiler-generated code;
847 -- hence the use of discardWarnings
848 (tc_aux_binds, tcl_env) <- discardWarnings (tcTopBinds aux_binds) ;
849 (tc_deriv_binds, tcl_env) <- setLclTypeEnv tcl_env $
850 discardWarnings (tcTopBinds deriv_binds) ;
852 -- Value declarations next
853 traceTc (text "Tc5") ;
854 (tc_val_binds, tcl_env) <- setLclTypeEnv tcl_env $
855 tcTopBinds val_binds;
857 -- Second pass over class and instance declarations,
858 traceTc (text "Tc6") ;
859 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $
860 tcInstDecls2 tycl_decls inst_infos ;
861 showLIE (text "after instDecls2") ;
863 setLclTypeEnv tcl_env $ do { -- Environment doesn't change now
866 traceTc (text "Tc7") ;
867 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
870 annotations <- tcAnnotations annotation_decls ;
873 rules <- tcRules rule_decls ;
876 traceTc (text "Tc7a") ;
877 tcg_env <- getGblEnv ;
878 let { all_binds = tc_val_binds `unionBags`
879 tc_deriv_binds `unionBags`
880 tc_aux_binds `unionBags`
881 inst_binds `unionBags`
884 -- Extend the GblEnv with the (as yet un-zonked)
885 -- bindings, rules, foreign decls
886 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
887 tcg_rules = tcg_rules tcg_env ++ rules,
888 tcg_anns = tcg_anns tcg_env ++ annotations,
889 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
890 return (tcg_env', tcl_env)
895 %************************************************************************
899 %************************************************************************
902 checkMain :: TcM TcGblEnv
903 -- If we are in module Main, check that 'main' is defined.
905 = do { tcg_env <- getGblEnv ;
907 check_main dflags tcg_env
910 check_main :: DynFlags -> TcGblEnv -> TcM TcGblEnv
911 check_main dflags tcg_env
913 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
917 = do { mb_main <- lookupGlobalOccRn_maybe main_fn
918 -- Check that 'main' is in scope
919 -- It might be imported from another module!
921 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
926 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
927 ; let loc = srcLocSpan (getSrcLoc main_name)
928 ; ioTyCon <- tcLookupTyCon ioTyConName
929 ; (main_expr, res_ty)
930 <- addErrCtxt mainCtxt $
931 withBox liftedTypeKind $ \res_ty ->
932 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
934 -- See Note [Root-main Id]
935 -- Construct the binding
936 -- :Main.main :: IO res_ty = runMainIO res_ty main
937 ; run_main_id <- tcLookupId runMainIOName
938 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
939 (mkVarOccFS (fsLit "main"))
940 (getSrcSpan main_name)
941 ; root_main_id = Id.mkExportedLocalId root_main_name
942 (mkTyConApp ioTyCon [res_ty])
943 ; co = mkWpTyApps [res_ty]
944 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
945 ; main_bind = mkVarBind root_main_id rhs }
947 ; return (tcg_env { tcg_main = Just main_name,
948 tcg_binds = tcg_binds tcg_env
950 tcg_dus = tcg_dus tcg_env
951 `plusDU` usesOnly (unitFV main_name)
952 -- Record the use of 'main', so that we don't
953 -- complain about it being defined but not used
957 mod = tcg_mod tcg_env
958 main_mod = mainModIs dflags
959 main_fn = getMainFun dflags
961 complain_no_main | ghcLink dflags == LinkInMemory = return ()
962 | otherwise = failWithTc noMainMsg
963 -- In interactive mode, don't worry about the absence of 'main'
964 -- In other modes, fail altogether, so that we don't go on
965 -- and complain a second time when processing the export list.
967 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
968 noMainMsg = ptext (sLit "The") <+> pp_main_fn
969 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
970 pp_main_fn = ppMainFn main_fn
972 ppMainFn :: RdrName -> SDoc
974 | main_fn == main_RDR_Unqual
975 = ptext (sLit "function") <+> quotes (ppr main_fn)
977 = ptext (sLit "main function") <+> quotes (ppr main_fn)
979 -- | Get the unqualified name of the function to use as the \"main\" for the main module.
980 -- Either returns the default name or the one configured on the command line with -main-is
981 getMainFun :: DynFlags -> RdrName
982 getMainFun dflags = case (mainFunIs dflags) of
983 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
984 Nothing -> main_RDR_Unqual
986 checkMainExported :: TcGblEnv -> TcM ()
987 checkMainExported tcg_env = do
989 case tcg_main tcg_env of
990 Nothing -> return () -- not the main module
992 let main_mod = mainModIs dflags
993 checkTc (main_name `elem` concatMap availNames (tcg_exports tcg_env)) $
994 ptext (sLit "The") <+> ppMainFn (nameRdrName main_name) <+>
995 ptext (sLit "is not exported by module") <+> quotes (ppr main_mod)
1000 The function that the RTS invokes is always :Main.main, which we call
1001 root_main_id. (Because GHC allows the user to have a module not
1002 called Main as the main module, we can't rely on the main function
1003 being called "Main.main". That's why root_main_id has a fixed module
1006 This is unusual: it's a LocalId whose Name has a Module from another
1007 module. Tiresomely, we must filter it out again in MkIface, les we
1008 get two defns for 'main' in the interface file!
1011 %*********************************************************
1015 %*********************************************************
1019 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
1020 setInteractiveContext hsc_env icxt thing_inside
1021 = let -- Initialise the tcg_inst_env with instances from all home modules.
1022 -- This mimics the more selective call to hptInstances in tcRnModule.
1023 (home_insts, home_fam_insts) = hptInstances hsc_env (\_ -> True)
1025 updGblEnv (\env -> env {
1026 tcg_rdr_env = ic_rn_gbl_env icxt,
1027 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
1028 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
1032 tcExtendGhciEnv (ic_tmp_ids icxt) $
1033 -- tcExtendGhciEnv does lots:
1034 -- - it extends the local type env (tcl_env) with the given Ids,
1035 -- - it extends the local rdr env (tcl_rdr) with the Names from
1037 -- - it adds the free tyvars of the Ids to the tcl_tyvars
1040 -- later ids in ic_tmp_ids must shadow earlier ones with the same
1041 -- OccName, and tcExtendIdEnv implements this behaviour.
1043 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
1050 -> InteractiveContext
1052 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1053 -- The returned [Id] is the list of new Ids bound by
1054 -- this statement. It can be used to extend the
1055 -- InteractiveContext via extendInteractiveContext.
1057 -- The returned TypecheckedHsExpr is of type IO [ () ],
1058 -- a list of the bound values, coerced to ().
1060 tcRnStmt hsc_env ictxt rdr_stmt
1061 = initTcPrintErrors hsc_env iNTERACTIVE $
1062 setInteractiveContext hsc_env ictxt $ do {
1064 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1065 (([rn_stmt], _), fvs) <- rnStmts GhciStmt [rdr_stmt] (return ((), emptyFVs)) ;
1066 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1068 rnDump (ppr rn_stmt) ;
1070 -- The real work is done here
1071 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1072 zonked_expr <- zonkTopLExpr tc_expr ;
1073 zonked_ids <- zonkTopBndrs bound_ids ;
1075 -- None of the Ids should be of unboxed type, because we
1076 -- cast them all to HValues in the end!
1077 mapM_ bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1079 traceTc (text "tcs 1") ;
1080 let { global_ids = map globaliseAndTidyId zonked_ids } ;
1081 -- Note [Interactively-bound Ids in GHCi]
1083 {- ---------------------------------------------
1084 At one stage I removed any shadowed bindings from the type_env;
1085 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1086 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1088 Prelude> let f n = n * 2 :: Int
1089 Prelude> fName <- runQ [| f |]
1090 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1092 Prelude> let f n = n * 3 :: Int
1093 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1094 In the last line we use 'fName', which resolves to the *first* 'f'
1095 in scope. If we delete it from the type env, GHCi crashes because
1096 it doesn't expect that.
1098 Hence this code is commented out
1100 -------------------------------------------------- -}
1102 dumpOptTcRn Opt_D_dump_tc
1103 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1104 text "Typechecked expr" <+> ppr zonked_expr]) ;
1106 return (global_ids, zonked_expr)
1109 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1110 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1113 Note [Interactively-bound Ids in GHCi]
1114 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1115 The Ids bound by previous Stmts in Template Haskell are currently
1117 b) with an Internal Name (not External)
1118 c) and a tidied type
1120 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1121 compile an expression using these ids later, the byte code
1122 generator will consider the occurrences to be free rather than
1125 (b) They retain their Internal names becuase we don't have a suitable
1126 Module to name them with. We could revisit this choice.
1128 (c) Their types are tidied. This is important, because :info may ask
1129 to look at them, and :info expects the things it looks up to have
1133 --------------------------------------------------------------------------
1134 Typechecking Stmts in GHCi
1136 Here is the grand plan, implemented in tcUserStmt
1138 What you type The IO [HValue] that hscStmt returns
1139 ------------- ------------------------------------
1140 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1143 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1146 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1147 [NB: result not printed] bindings: [it]
1149 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1150 result showable) bindings: [it]
1152 expr (of non-IO type,
1153 result not showable) ==> error
1157 ---------------------------
1158 type PlanResult = ([Id], LHsExpr Id)
1159 type Plan = TcM PlanResult
1161 runPlans :: [Plan] -> TcM PlanResult
1162 -- Try the plans in order. If one fails (by raising an exn), try the next.
1163 -- If one succeeds, take it.
1164 runPlans [] = panic "runPlans"
1166 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1168 --------------------
1169 mkPlan :: LStmt Name -> TcM PlanResult
1170 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1171 = do { uniq <- newUnique -- is treated very specially
1172 ; let fresh_it = itName uniq
1173 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1174 matches = [mkMatch [] expr emptyLocalBinds]
1175 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1176 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1177 (HsVar bindIOName) noSyntaxExpr
1178 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1179 (HsVar thenIOName) placeHolderType
1182 -- [it <- e; print it] but not if it::()
1184 -- [let it = e; print it]
1185 ; runPlans [ -- Plan A
1186 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1187 ; it_ty <- zonkTcType (idType it_id)
1188 ; when (isUnitTy it_ty) failM
1191 -- Plan B; a naked bind statment
1192 tcGhciStmts [bind_stmt],
1194 -- Plan C; check that the let-binding is typeable all by itself.
1195 -- If not, fail; if so, try to print it.
1196 -- The two-step process avoids getting two errors: one from
1197 -- the expression itself, and one from the 'print it' part
1198 -- This two-step story is very clunky, alas
1199 do { _ <- checkNoErrs (tcGhciStmts [let_stmt])
1200 --- checkNoErrs defeats the error recovery of let-bindings
1201 ; tcGhciStmts [let_stmt, print_it] }
1204 mkPlan stmt@(L loc (BindStmt {}))
1205 | [v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1206 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1207 (HsVar thenIOName) placeHolderType
1209 ; print_bind_result <- doptM Opt_PrintBindResult
1210 ; let print_plan = do
1211 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1212 ; v_ty <- zonkTcType (idType v_id)
1213 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1217 -- [stmt; print v] but not if v::()
1219 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1220 [tcGhciStmts [stmt]])
1224 = tcGhciStmts [stmt]
1226 ---------------------------
1227 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1229 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1230 ret_id <- tcLookupId returnIOName ; -- return @ IO
1232 ret_ty = mkListTy unitTy ;
1233 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1234 tc_io_stmts stmts = tcStmts GhciStmt tcDoStmt stmts io_ret_ty ;
1236 names = collectLStmtsBinders stmts ;
1238 -- mk_return builds the expression
1239 -- returnIO @ [()] [coerce () x, .., coerce () z]
1241 -- Despite the inconvenience of building the type applications etc,
1242 -- this *has* to be done in type-annotated post-typecheck form
1243 -- because we are going to return a list of *polymorphic* values
1244 -- coerced to type (). If we built a *source* stmt
1245 -- return [coerce x, ..., coerce z]
1246 -- then the type checker would instantiate x..z, and we wouldn't
1247 -- get their *polymorphic* values. (And we'd get ambiguity errs
1248 -- if they were overloaded, since they aren't applied to anything.)
1249 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1250 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1251 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1255 -- OK, we're ready to typecheck the stmts
1256 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1257 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1258 mapM tcLookupId names ;
1259 -- Look up the names right in the middle,
1260 -- where they will all be in scope
1262 -- Simplify the context
1263 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1264 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1265 -- checkNoErrs ensures that the plan fails if context redn fails
1267 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1268 return (ids, mkHsDictLet const_binds $
1269 noLoc (HsDo GhciStmt tc_stmts (mk_return ids) io_ret_ty))
1274 tcRnExpr just finds the type of an expression
1278 -> InteractiveContext
1280 -> IO (Messages, Maybe Type)
1281 tcRnExpr hsc_env ictxt rdr_expr
1282 = initTcPrintErrors hsc_env iNTERACTIVE $
1283 setInteractiveContext hsc_env ictxt $ do {
1285 (rn_expr, _fvs) <- rnLExpr rdr_expr ;
1288 -- Now typecheck the expression;
1289 -- it might have a rank-2 type (e.g. :t runST)
1290 ((_tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1291 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1292 _ <- tcSimplifyInteractive lie_top ; -- Ignore the dicionary bindings
1294 let { all_expr_ty = mkForAllTys qtvs $
1295 mkFunTys (map (idType . instToId) dict_insts) $
1297 zonkTcType all_expr_ty
1300 smpl_doc = ptext (sLit "main expression")
1303 tcRnType just finds the kind of a type
1307 -> InteractiveContext
1309 -> IO (Messages, Maybe Kind)
1310 tcRnType hsc_env ictxt rdr_type
1311 = initTcPrintErrors hsc_env iNTERACTIVE $
1312 setInteractiveContext hsc_env ictxt $ do {
1314 rn_type <- rnLHsType doc rdr_type ;
1317 -- Now kind-check the type
1318 (_ty', kind) <- kcLHsType rn_type ;
1322 doc = ptext (sLit "In GHCi input")
1328 %************************************************************************
1330 More GHCi stuff, to do with browsing and getting info
1332 %************************************************************************
1336 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1337 -- a package module with an interface on disk. If neither of these is
1338 -- true, then the result will be an error indicating the interface
1339 -- could not be found.
1340 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1341 getModuleExports hsc_env mod
1344 checkMods = ic_toplev_scope ic ++ ic_exports ic
1346 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1348 -- Get the export avail info and also load all orphan and family-instance
1349 -- modules. Finally, check that the family instances of all modules in the
1350 -- interactive context are consistent (these modules are in the second
1352 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1353 tcGetModuleExports mod directlyImpMods
1354 = do { let doc = ptext (sLit "context for compiling statements")
1355 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1357 -- Load any orphan-module and family instance-module
1358 -- interfaces, so their instances are visible.
1359 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1360 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1362 -- Check that the family instances of all directly loaded
1363 -- modules are consistent.
1364 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1366 ; ifaceExportNames (mi_exports iface)
1369 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1370 tcRnLookupRdrName hsc_env rdr_name
1371 = initTcPrintErrors hsc_env iNTERACTIVE $
1372 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1373 lookup_rdr_name rdr_name
1375 lookup_rdr_name :: RdrName -> TcM [Name]
1376 lookup_rdr_name rdr_name = do {
1377 -- If the identifier is a constructor (begins with an
1378 -- upper-case letter), then we need to consider both
1379 -- constructor and type class identifiers.
1380 let { rdr_names = dataTcOccs rdr_name } ;
1382 -- results :: [Either Messages Name]
1383 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1385 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1386 -- The successful lookups will be (Just name)
1387 let { (warns_s, good_names) = unzip [ (msgs, name)
1388 | (msgs, Just name) <- results] ;
1389 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1391 -- Fail if nothing good happened, else add warnings
1392 if null good_names then
1393 -- No lookup succeeded, so
1394 -- pick the first error message and report it
1395 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1396 -- while the other is "X is not in scope",
1397 -- we definitely want the former; but we might pick the latter
1398 do { addMessages (head errs_s) ; failM }
1399 else -- Add deprecation warnings
1400 mapM_ addMessages warns_s ;
1405 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1406 tcRnLookupName hsc_env name
1407 = initTcPrintErrors hsc_env iNTERACTIVE $
1408 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1409 tcRnLookupName' name
1411 -- To look up a name we have to look in the local environment (tcl_lcl)
1412 -- as well as the global environment, which is what tcLookup does.
1413 -- But we also want a TyThing, so we have to convert:
1415 tcRnLookupName' :: Name -> TcRn TyThing
1416 tcRnLookupName' name = do
1417 tcthing <- tcLookup name
1419 AGlobal thing -> return thing
1420 ATcId{tct_id=id} -> return (AnId id)
1421 _ -> panic "tcRnLookupName'"
1423 tcRnGetInfo :: HscEnv
1425 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1427 -- Used to implement :info in GHCi
1429 -- Look up a RdrName and return all the TyThings it might be
1430 -- A capitalised RdrName is given to us in the DataName namespace,
1431 -- but we want to treat it as *both* a data constructor
1432 -- *and* as a type or class constructor;
1433 -- hence the call to dataTcOccs, and we return up to two results
1434 tcRnGetInfo hsc_env name
1435 = initTcPrintErrors hsc_env iNTERACTIVE $
1436 let ictxt = hsc_IC hsc_env in
1437 setInteractiveContext hsc_env ictxt $ do
1439 -- Load the interface for all unqualified types and classes
1440 -- That way we will find all the instance declarations
1441 -- (Packages have not orphan modules, and we assume that
1442 -- in the home package all relevant modules are loaded.)
1443 loadUnqualIfaces ictxt
1445 thing <- tcRnLookupName' name
1446 fixity <- lookupFixityRn name
1447 ispecs <- lookupInsts thing
1448 return (thing, fixity, ispecs)
1450 lookupInsts :: TyThing -> TcM [Instance]
1451 lookupInsts (AClass cls)
1452 = do { inst_envs <- tcGetInstEnvs
1453 ; return (classInstances inst_envs cls) }
1455 lookupInsts (ATyCon tc)
1456 = do { (pkg_ie, home_ie) <- tcGetInstEnvs
1457 -- Load all instances for all classes that are
1458 -- in the type environment (which are all the ones
1459 -- we've seen in any interface file so far)
1460 ; return [ ispec -- Search all
1461 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1462 , let dfun = instanceDFunId ispec
1465 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1466 tc_name = tyConName tc
1468 lookupInsts _ = return []
1470 loadUnqualIfaces :: InteractiveContext -> TcM ()
1471 -- Load the home module for everything that is in scope unqualified
1472 -- This is so that we can accurately report the instances for
1474 loadUnqualIfaces ictxt
1476 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1478 unqual_mods = [ nameModule name
1479 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1480 let name = gre_name gre,
1481 not (isInternalName name),
1482 isTcOcc (nameOccName name), -- Types and classes only
1483 unQualOK gre ] -- In scope unqualified
1484 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1488 %************************************************************************
1492 %************************************************************************
1495 rnDump :: SDoc -> TcRn ()
1496 -- Dump, with a banner, if -ddump-rn
1497 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1499 tcDump :: TcGblEnv -> TcRn ()
1501 = do { dflags <- getDOpts ;
1503 -- Dump short output if -ddump-types or -ddump-tc
1504 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1505 (dumpTcRn short_dump) ;
1507 -- Dump bindings if -ddump-tc
1508 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1511 short_dump = pprTcGblEnv env
1512 full_dump = pprLHsBinds (tcg_binds env)
1513 -- NB: foreign x-d's have undefined's in their types;
1514 -- hence can't show the tc_fords
1516 tcCoreDump :: ModGuts -> TcM ()
1518 = do { dflags <- getDOpts ;
1519 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1520 (dumpTcRn (pprModGuts mod_guts)) ;
1522 -- Dump bindings if -ddump-tc
1523 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1525 full_dump = pprCoreBindings (mg_binds mod_guts)
1527 -- It's unpleasant having both pprModGuts and pprModDetails here
1528 pprTcGblEnv :: TcGblEnv -> SDoc
1529 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1531 tcg_fam_insts = fam_insts,
1533 tcg_imports = imports })
1534 = vcat [ ppr_types insts type_env
1535 , ppr_tycons fam_insts type_env
1537 , ppr_fam_insts fam_insts
1538 , vcat (map ppr rules)
1539 , ppr_gen_tycons (typeEnvTyCons type_env)
1540 , ptext (sLit "Dependent modules:") <+>
1541 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1542 , ptext (sLit "Dependent packages:") <+>
1543 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1544 where -- The two uses of sortBy are just to reduce unnecessary
1545 -- wobbling in testsuite output
1546 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1547 = (mod_name1 `stableModuleNameCmp` mod_name2)
1549 (is_boot1 `compare` is_boot2)
1551 pprModGuts :: ModGuts -> SDoc
1552 pprModGuts (ModGuts { mg_types = type_env,
1554 = vcat [ ppr_types [] type_env,
1557 ppr_types :: [Instance] -> TypeEnv -> SDoc
1558 ppr_types insts type_env
1559 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1561 dfun_ids = map instanceDFunId insts
1562 ids = [id | id <- typeEnvIds type_env, want_sig id]
1563 want_sig id | opt_PprStyle_Debug = True
1564 | otherwise = isLocalId id &&
1565 isExternalName (idName id) &&
1566 not (id `elem` dfun_ids)
1567 -- isLocalId ignores data constructors, records selectors etc.
1568 -- The isExternalName ignores local dictionary and method bindings
1569 -- that the type checker has invented. Top-level user-defined things
1570 -- have External names.
1572 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1573 ppr_tycons fam_insts type_env
1574 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1576 fi_tycons = map famInstTyCon fam_insts
1577 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1578 want_tycon tycon | opt_PprStyle_Debug = True
1579 | otherwise = not (isImplicitTyCon tycon) &&
1580 isExternalName (tyConName tycon) &&
1581 not (tycon `elem` fi_tycons)
1583 ppr_insts :: [Instance] -> SDoc
1584 ppr_insts [] = empty
1585 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1587 ppr_fam_insts :: [FamInst] -> SDoc
1588 ppr_fam_insts [] = empty
1589 ppr_fam_insts fam_insts =
1590 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1592 ppr_sigs :: [Var] -> SDoc
1594 -- Print type signatures; sort by OccName
1595 = vcat (map ppr_sig (sortLe le_sig ids))
1597 le_sig id1 id2 = getOccName id1 <= getOccName id2
1598 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1600 ppr_tydecls :: [TyCon] -> SDoc
1602 -- Print type constructor info; sort by OccName
1603 = vcat (map ppr_tycon (sortLe le_sig tycons))
1605 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1607 | isCoercionTyCon tycon
1608 = sep [ptext (sLit "coercion") <+> ppr tycon <+> ppr tvs
1609 , nest 2 (dcolon <+> pprEqPred (coercionKind (mkTyConApp tycon (mkTyVarTys tvs))))]
1610 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1612 tvs = take (tyConArity tycon) alphaTyVars
1614 ppr_rules :: [CoreRule] -> SDoc
1615 ppr_rules [] = empty
1616 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1617 nest 4 (pprRules rs),
1620 ppr_gen_tycons :: [TyCon] -> SDoc
1621 ppr_gen_tycons [] = empty
1622 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1623 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]