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 tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds,
570 tcg_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 [ mkVarBind boot_dfun (nlHsVar dfun)
574 | (boot_dfun, dfun) <- dfun_prs ]
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 &&
662 def_meth1 == def_meth2
664 (_, rho_ty1) = splitForAllTys (idType id1)
665 op_ty1 = funResultTy rho_ty1
666 (_, rho_ty2) = splitForAllTys (idType id2)
667 op_ty2 = funResultTy rho_ty2
669 eqFD (as1,bs1) (as2,bs2) =
670 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
671 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
673 same_kind tv1 tv2 = eqKind (tyVarKind tv1) (tyVarKind tv2)
675 eqListBy same_kind clas_tyvars1 clas_tyvars2 &&
676 -- Checks kind of class
677 eqListBy eqFD clas_fds1 clas_fds2 &&
678 (null sc_theta1 && null op_stuff1 && null ats1
679 || -- Above tests for an "abstract" class
680 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
681 eqListBy eqSig op_stuff1 op_stuff2 &&
682 eqListBy checkBootTyCon ats1 ats2)
684 checkBootDecl (ADataCon dc1) (ADataCon _)
685 = pprPanic "checkBootDecl" (ppr dc1)
687 checkBootDecl _ _ = False -- probably shouldn't happen
690 checkBootTyCon :: TyCon -> TyCon -> Bool
691 checkBootTyCon tc1 tc2
692 | not (eqKind (tyConKind tc1) (tyConKind tc2))
693 = False -- First off, check the kind
695 | isSynTyCon tc1 && isSynTyCon tc2
697 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
698 env = rnBndrs2 env0 tvs1 tvs2
700 eqSynRhs (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
701 = tcEqTypeX env k1 k2
702 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
703 = tcEqTypeX env t1 t2
706 equalLength tvs1 tvs2 &&
707 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
709 | isAlgTyCon tc1 && isAlgTyCon tc2
711 eqKind (tyConKind tc1) (tyConKind tc2) &&
712 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2) &&
713 eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
715 | isForeignTyCon tc1 && isForeignTyCon tc2
716 = eqKind (tyConKind tc1) (tyConKind tc2) &&
717 tyConExtName tc1 == tyConExtName tc2
721 env0 = mkRnEnv2 emptyInScopeSet
723 eqAlgRhs AbstractTyCon _ = True
724 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
725 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
726 eqListBy eqCon (data_cons tc1) (data_cons tc2)
727 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
728 eqCon (data_con tc1) (data_con tc2)
732 = dataConName c1 == dataConName c2
733 && dataConIsInfix c1 == dataConIsInfix c2
734 && dataConStrictMarks c1 == dataConStrictMarks c2
735 && dataConFieldLabels c1 == dataConFieldLabels c2
736 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
737 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
738 env = rnBndrs2 env0 tvs1 tvs2
740 equalLength tvs1 tvs2 &&
741 eqListBy (tcEqPredX env)
742 (dataConEqTheta c1 ++ dataConDictTheta c1)
743 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
744 eqListBy (tcEqTypeX env)
745 (dataConOrigArgTys c1)
746 (dataConOrigArgTys c2)
749 missingBootThing :: Name -> String -> SDoc
750 missingBootThing name what
751 = ppr name <+> ptext (sLit "is exported by the hs-boot file, but not")
752 <+> text what <+> ptext (sLit "the module")
754 bootMisMatch :: TyThing -> IfaceDecl -> IfaceDecl -> SDoc
755 bootMisMatch thing boot_decl real_decl
756 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
757 ptext (sLit "Main module:") <+> ppr real_decl,
758 ptext (sLit "Boot file: ") <+> ppr boot_decl]
760 instMisMatch :: Instance -> SDoc
763 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
767 %************************************************************************
769 Type-checking the top level of a module
771 %************************************************************************
773 tcRnGroup takes a bunch of top-level source-code declarations, and
775 * gets supporting declarations from interface files
778 * and augments the TcGblEnv with the results
780 In Template Haskell it may be called repeatedly for each group of
781 declarations. It expects there to be an incoming TcGblEnv in the
782 monad; it augments it and returns the new TcGblEnv.
785 ------------------------------------------------
786 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
787 -- Fails if there are any errors
789 = do { -- Rename the source decls
790 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
792 -- save the renamed syntax, if we want it
794 | Just grp <- tcg_rn_decls tcg_env
795 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
799 -- Dump trace of renaming part
800 rnDump (ppr rn_decls) ;
802 return (tcg_env', rn_decls)
805 ------------------------------------------------
806 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
807 tcTopSrcDecls boot_details
808 (HsGroup { hs_tyclds = tycl_decls,
809 hs_instds = inst_decls,
810 hs_derivds = deriv_decls,
811 hs_fords = foreign_decls,
812 hs_defds = default_decls,
813 hs_annds = annotation_decls,
814 hs_ruleds = rule_decls,
815 hs_valds = val_binds })
816 = do { -- Type-check the type and class decls, and all imported decls
817 -- The latter come in via tycl_decls
818 traceTc (text "Tc2") ;
820 (tcg_env, aux_binds) <- tcTyAndClassDecls boot_details tycl_decls ;
821 -- If there are any errors, tcTyAndClassDecls fails here
823 setGblEnv tcg_env $ do {
824 -- Source-language instances, including derivings,
825 -- and import the supporting declarations
826 traceTc (text "Tc3") ;
827 (tcg_env, inst_infos, deriv_binds)
828 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
829 setGblEnv tcg_env $ do {
831 -- Foreign import declarations next.
832 traceTc (text "Tc4") ;
833 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
834 tcExtendGlobalValEnv fi_ids $ do {
836 -- Default declarations
837 traceTc (text "Tc4a") ;
838 default_tys <- tcDefaults default_decls ;
839 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
841 -- Now GHC-generated derived bindings, generics, and selectors
842 -- Do not generate warnings from compiler-generated code;
843 -- hence the use of discardWarnings
844 (tc_aux_binds, tcl_env) <- discardWarnings (tcTopBinds aux_binds) ;
845 (tc_deriv_binds, tcl_env) <- setLclTypeEnv tcl_env $
846 discardWarnings (tcTopBinds deriv_binds) ;
848 -- Value declarations next
849 traceTc (text "Tc5") ;
850 (tc_val_binds, tcl_env) <- setLclTypeEnv tcl_env $
851 tcTopBinds val_binds;
853 -- Second pass over class and instance declarations,
854 traceTc (text "Tc6") ;
855 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $
856 tcInstDecls2 tycl_decls inst_infos ;
857 showLIE (text "after instDecls2") ;
859 setLclTypeEnv tcl_env $ do { -- Environment doesn't change now
862 traceTc (text "Tc7") ;
863 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
866 annotations <- tcAnnotations annotation_decls ;
869 rules <- tcRules rule_decls ;
872 traceTc (text "Tc7a") ;
873 tcg_env <- getGblEnv ;
874 let { all_binds = tc_val_binds `unionBags`
875 tc_deriv_binds `unionBags`
876 tc_aux_binds `unionBags`
877 inst_binds `unionBags`
880 -- Extend the GblEnv with the (as yet un-zonked)
881 -- bindings, rules, foreign decls
882 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
883 tcg_rules = tcg_rules tcg_env ++ rules,
884 tcg_anns = tcg_anns tcg_env ++ annotations,
885 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
886 return (tcg_env', tcl_env)
891 %************************************************************************
895 %************************************************************************
898 checkMain :: TcM TcGblEnv
899 -- If we are in module Main, check that 'main' is defined.
901 = do { tcg_env <- getGblEnv ;
903 check_main dflags tcg_env
906 check_main :: DynFlags -> TcGblEnv -> TcM TcGblEnv
907 check_main dflags tcg_env
909 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
913 = do { mb_main <- lookupGlobalOccRn_maybe main_fn
914 -- Check that 'main' is in scope
915 -- It might be imported from another module!
917 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
922 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
923 ; let loc = srcLocSpan (getSrcLoc main_name)
924 ; ioTyCon <- tcLookupTyCon ioTyConName
925 ; (main_expr, res_ty)
926 <- addErrCtxt mainCtxt $
927 withBox liftedTypeKind $ \res_ty ->
928 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
930 -- See Note [Root-main Id]
931 -- Construct the binding
932 -- :Main.main :: IO res_ty = runMainIO res_ty main
933 ; run_main_id <- tcLookupId runMainIOName
934 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
935 (mkVarOccFS (fsLit "main"))
936 (getSrcSpan main_name)
937 ; root_main_id = Id.mkExportedLocalId root_main_name
938 (mkTyConApp ioTyCon [res_ty])
939 ; co = mkWpTyApps [res_ty]
940 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
941 ; main_bind = mkVarBind root_main_id rhs }
943 ; return (tcg_env { tcg_main = Just main_name,
944 tcg_binds = tcg_binds tcg_env
946 tcg_dus = tcg_dus tcg_env
947 `plusDU` usesOnly (unitFV main_name)
948 -- Record the use of 'main', so that we don't
949 -- complain about it being defined but not used
953 mod = tcg_mod tcg_env
954 main_mod = mainModIs dflags
955 main_fn = getMainFun dflags
957 complain_no_main | ghcLink dflags == LinkInMemory = return ()
958 | otherwise = failWithTc noMainMsg
959 -- In interactive mode, don't worry about the absence of 'main'
960 -- In other modes, fail altogether, so that we don't go on
961 -- and complain a second time when processing the export list.
963 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
964 noMainMsg = ptext (sLit "The") <+> pp_main_fn
965 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
966 pp_main_fn = ppMainFn main_fn
968 ppMainFn :: RdrName -> SDoc
970 | main_fn == main_RDR_Unqual
971 = ptext (sLit "function") <+> quotes (ppr main_fn)
973 = ptext (sLit "main function") <+> quotes (ppr main_fn)
975 -- | Get the unqualified name of the function to use as the \"main\" for the main module.
976 -- Either returns the default name or the one configured on the command line with -main-is
977 getMainFun :: DynFlags -> RdrName
978 getMainFun dflags = case (mainFunIs dflags) of
979 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
980 Nothing -> main_RDR_Unqual
982 checkMainExported :: TcGblEnv -> TcM ()
983 checkMainExported tcg_env = do
985 case tcg_main tcg_env of
986 Nothing -> return () -- not the main module
988 let main_mod = mainModIs dflags
989 checkTc (main_name `elem` concatMap availNames (tcg_exports tcg_env)) $
990 ptext (sLit "The") <+> ppMainFn (nameRdrName main_name) <+>
991 ptext (sLit "is not exported by module") <+> quotes (ppr main_mod)
996 The function that the RTS invokes is always :Main.main, which we call
997 root_main_id. (Because GHC allows the user to have a module not
998 called Main as the main module, we can't rely on the main function
999 being called "Main.main". That's why root_main_id has a fixed module
1002 This is unusual: it's a LocalId whose Name has a Module from another
1003 module. Tiresomely, we must filter it out again in MkIface, les we
1004 get two defns for 'main' in the interface file!
1007 %*********************************************************
1011 %*********************************************************
1015 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
1016 setInteractiveContext hsc_env icxt thing_inside
1017 = let -- Initialise the tcg_inst_env with instances from all home modules.
1018 -- This mimics the more selective call to hptInstances in tcRnModule.
1019 (home_insts, home_fam_insts) = hptInstances hsc_env (\_ -> True)
1021 updGblEnv (\env -> env {
1022 tcg_rdr_env = ic_rn_gbl_env icxt,
1023 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
1024 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
1028 tcExtendGhciEnv (ic_tmp_ids icxt) $
1029 -- tcExtendGhciEnv does lots:
1030 -- - it extends the local type env (tcl_env) with the given Ids,
1031 -- - it extends the local rdr env (tcl_rdr) with the Names from
1033 -- - it adds the free tyvars of the Ids to the tcl_tyvars
1036 -- later ids in ic_tmp_ids must shadow earlier ones with the same
1037 -- OccName, and tcExtendIdEnv implements this behaviour.
1039 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
1046 -> InteractiveContext
1048 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1049 -- The returned [Id] is the list of new Ids bound by
1050 -- this statement. It can be used to extend the
1051 -- InteractiveContext via extendInteractiveContext.
1053 -- The returned TypecheckedHsExpr is of type IO [ () ],
1054 -- a list of the bound values, coerced to ().
1056 tcRnStmt hsc_env ictxt rdr_stmt
1057 = initTcPrintErrors hsc_env iNTERACTIVE $
1058 setInteractiveContext hsc_env ictxt $ do {
1060 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1061 (([rn_stmt], _), fvs) <- rnStmts GhciStmt [rdr_stmt] (return ((), emptyFVs)) ;
1062 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1064 rnDump (ppr rn_stmt) ;
1066 -- The real work is done here
1067 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1068 zonked_expr <- zonkTopLExpr tc_expr ;
1069 zonked_ids <- zonkTopBndrs bound_ids ;
1071 -- None of the Ids should be of unboxed type, because we
1072 -- cast them all to HValues in the end!
1073 mapM_ bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1075 traceTc (text "tcs 1") ;
1076 let { global_ids = map globaliseAndTidyId zonked_ids } ;
1077 -- Note [Interactively-bound Ids in GHCi]
1079 {- ---------------------------------------------
1080 At one stage I removed any shadowed bindings from the type_env;
1081 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1082 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1084 Prelude> let f n = n * 2 :: Int
1085 Prelude> fName <- runQ [| f |]
1086 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1088 Prelude> let f n = n * 3 :: Int
1089 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1090 In the last line we use 'fName', which resolves to the *first* 'f'
1091 in scope. If we delete it from the type env, GHCi crashes because
1092 it doesn't expect that.
1094 Hence this code is commented out
1096 -------------------------------------------------- -}
1098 dumpOptTcRn Opt_D_dump_tc
1099 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1100 text "Typechecked expr" <+> ppr zonked_expr]) ;
1102 return (global_ids, zonked_expr)
1105 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1106 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1109 Note [Interactively-bound Ids in GHCi]
1110 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1111 The Ids bound by previous Stmts in Template Haskell are currently
1113 b) with an Internal Name (not External)
1114 c) and a tidied type
1116 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1117 compile an expression using these ids later, the byte code
1118 generator will consider the occurrences to be free rather than
1121 (b) They retain their Internal names becuase we don't have a suitable
1122 Module to name them with. We could revisit this choice.
1124 (c) Their types are tidied. This is important, because :info may ask
1125 to look at them, and :info expects the things it looks up to have
1129 --------------------------------------------------------------------------
1130 Typechecking Stmts in GHCi
1132 Here is the grand plan, implemented in tcUserStmt
1134 What you type The IO [HValue] that hscStmt returns
1135 ------------- ------------------------------------
1136 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1139 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1142 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1143 [NB: result not printed] bindings: [it]
1145 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1146 result showable) bindings: [it]
1148 expr (of non-IO type,
1149 result not showable) ==> error
1153 ---------------------------
1154 type PlanResult = ([Id], LHsExpr Id)
1155 type Plan = TcM PlanResult
1157 runPlans :: [Plan] -> TcM PlanResult
1158 -- Try the plans in order. If one fails (by raising an exn), try the next.
1159 -- If one succeeds, take it.
1160 runPlans [] = panic "runPlans"
1162 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1164 --------------------
1165 mkPlan :: LStmt Name -> TcM PlanResult
1166 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1167 = do { uniq <- newUnique -- is treated very specially
1168 ; let fresh_it = itName uniq
1169 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1170 matches = [mkMatch [] expr emptyLocalBinds]
1171 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1172 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1173 (HsVar bindIOName) noSyntaxExpr
1174 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1175 (HsVar thenIOName) placeHolderType
1178 -- [it <- e; print it] but not if it::()
1180 -- [let it = e; print it]
1181 ; runPlans [ -- Plan A
1182 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1183 ; it_ty <- zonkTcType (idType it_id)
1184 ; when (isUnitTy it_ty) failM
1187 -- Plan B; a naked bind statment
1188 tcGhciStmts [bind_stmt],
1190 -- Plan C; check that the let-binding is typeable all by itself.
1191 -- If not, fail; if so, try to print it.
1192 -- The two-step process avoids getting two errors: one from
1193 -- the expression itself, and one from the 'print it' part
1194 -- This two-step story is very clunky, alas
1195 do { _ <- checkNoErrs (tcGhciStmts [let_stmt])
1196 --- checkNoErrs defeats the error recovery of let-bindings
1197 ; tcGhciStmts [let_stmt, print_it] }
1200 mkPlan stmt@(L loc (BindStmt {}))
1201 | [v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1202 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1203 (HsVar thenIOName) placeHolderType
1205 ; print_bind_result <- doptM Opt_PrintBindResult
1206 ; let print_plan = do
1207 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1208 ; v_ty <- zonkTcType (idType v_id)
1209 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1213 -- [stmt; print v] but not if v::()
1215 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1216 [tcGhciStmts [stmt]])
1220 = tcGhciStmts [stmt]
1222 ---------------------------
1223 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1225 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1226 ret_id <- tcLookupId returnIOName ; -- return @ IO
1228 ret_ty = mkListTy unitTy ;
1229 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1230 tc_io_stmts stmts = tcStmts GhciStmt tcDoStmt stmts io_ret_ty ;
1232 names = collectLStmtsBinders stmts ;
1234 -- mk_return builds the expression
1235 -- returnIO @ [()] [coerce () x, .., coerce () z]
1237 -- Despite the inconvenience of building the type applications etc,
1238 -- this *has* to be done in type-annotated post-typecheck form
1239 -- because we are going to return a list of *polymorphic* values
1240 -- coerced to type (). If we built a *source* stmt
1241 -- return [coerce x, ..., coerce z]
1242 -- then the type checker would instantiate x..z, and we wouldn't
1243 -- get their *polymorphic* values. (And we'd get ambiguity errs
1244 -- if they were overloaded, since they aren't applied to anything.)
1245 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1246 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1247 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1251 -- OK, we're ready to typecheck the stmts
1252 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1253 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1254 mapM tcLookupId names ;
1255 -- Look up the names right in the middle,
1256 -- where they will all be in scope
1258 -- Simplify the context
1259 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1260 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1261 -- checkNoErrs ensures that the plan fails if context redn fails
1263 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1264 return (ids, mkHsDictLet const_binds $
1265 noLoc (HsDo GhciStmt tc_stmts (mk_return ids) io_ret_ty))
1270 tcRnExpr just finds the type of an expression
1274 -> InteractiveContext
1276 -> IO (Messages, Maybe Type)
1277 tcRnExpr hsc_env ictxt rdr_expr
1278 = initTcPrintErrors hsc_env iNTERACTIVE $
1279 setInteractiveContext hsc_env ictxt $ do {
1281 (rn_expr, _fvs) <- rnLExpr rdr_expr ;
1284 -- Now typecheck the expression;
1285 -- it might have a rank-2 type (e.g. :t runST)
1286 ((_tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1287 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1288 _ <- tcSimplifyInteractive lie_top ; -- Ignore the dicionary bindings
1290 let { all_expr_ty = mkForAllTys qtvs $
1291 mkFunTys (map (idType . instToId) dict_insts) $
1293 zonkTcType all_expr_ty
1296 smpl_doc = ptext (sLit "main expression")
1299 tcRnType just finds the kind of a type
1303 -> InteractiveContext
1305 -> IO (Messages, Maybe Kind)
1306 tcRnType hsc_env ictxt rdr_type
1307 = initTcPrintErrors hsc_env iNTERACTIVE $
1308 setInteractiveContext hsc_env ictxt $ do {
1310 rn_type <- rnLHsType doc rdr_type ;
1313 -- Now kind-check the type
1314 (_ty', kind) <- kcLHsType rn_type ;
1318 doc = ptext (sLit "In GHCi input")
1324 %************************************************************************
1326 More GHCi stuff, to do with browsing and getting info
1328 %************************************************************************
1332 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1333 -- a package module with an interface on disk. If neither of these is
1334 -- true, then the result will be an error indicating the interface
1335 -- could not be found.
1336 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1337 getModuleExports hsc_env mod
1340 checkMods = ic_toplev_scope ic ++ ic_exports ic
1342 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1344 -- Get the export avail info and also load all orphan and family-instance
1345 -- modules. Finally, check that the family instances of all modules in the
1346 -- interactive context are consistent (these modules are in the second
1348 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1349 tcGetModuleExports mod directlyImpMods
1350 = do { let doc = ptext (sLit "context for compiling statements")
1351 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1353 -- Load any orphan-module and family instance-module
1354 -- interfaces, so their instances are visible.
1355 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1356 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1358 -- Check that the family instances of all directly loaded
1359 -- modules are consistent.
1360 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1362 ; ifaceExportNames (mi_exports iface)
1365 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1366 tcRnLookupRdrName hsc_env rdr_name
1367 = initTcPrintErrors hsc_env iNTERACTIVE $
1368 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1369 lookup_rdr_name rdr_name
1371 lookup_rdr_name :: RdrName -> TcM [Name]
1372 lookup_rdr_name rdr_name = do {
1373 -- If the identifier is a constructor (begins with an
1374 -- upper-case letter), then we need to consider both
1375 -- constructor and type class identifiers.
1376 let { rdr_names = dataTcOccs rdr_name } ;
1378 -- results :: [Either Messages Name]
1379 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1381 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1382 -- The successful lookups will be (Just name)
1383 let { (warns_s, good_names) = unzip [ (msgs, name)
1384 | (msgs, Just name) <- results] ;
1385 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1387 -- Fail if nothing good happened, else add warnings
1388 if null good_names then
1389 -- No lookup succeeded, so
1390 -- pick the first error message and report it
1391 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1392 -- while the other is "X is not in scope",
1393 -- we definitely want the former; but we might pick the latter
1394 do { addMessages (head errs_s) ; failM }
1395 else -- Add deprecation warnings
1396 mapM_ addMessages warns_s ;
1401 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1402 tcRnLookupName hsc_env name
1403 = initTcPrintErrors hsc_env iNTERACTIVE $
1404 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1405 tcRnLookupName' name
1407 -- To look up a name we have to look in the local environment (tcl_lcl)
1408 -- as well as the global environment, which is what tcLookup does.
1409 -- But we also want a TyThing, so we have to convert:
1411 tcRnLookupName' :: Name -> TcRn TyThing
1412 tcRnLookupName' name = do
1413 tcthing <- tcLookup name
1415 AGlobal thing -> return thing
1416 ATcId{tct_id=id} -> return (AnId id)
1417 _ -> panic "tcRnLookupName'"
1419 tcRnGetInfo :: HscEnv
1421 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1423 -- Used to implement :info in GHCi
1425 -- Look up a RdrName and return all the TyThings it might be
1426 -- A capitalised RdrName is given to us in the DataName namespace,
1427 -- but we want to treat it as *both* a data constructor
1428 -- *and* as a type or class constructor;
1429 -- hence the call to dataTcOccs, and we return up to two results
1430 tcRnGetInfo hsc_env name
1431 = initTcPrintErrors hsc_env iNTERACTIVE $
1432 let ictxt = hsc_IC hsc_env in
1433 setInteractiveContext hsc_env ictxt $ do
1435 -- Load the interface for all unqualified types and classes
1436 -- That way we will find all the instance declarations
1437 -- (Packages have not orphan modules, and we assume that
1438 -- in the home package all relevant modules are loaded.)
1439 loadUnqualIfaces ictxt
1441 thing <- tcRnLookupName' name
1442 fixity <- lookupFixityRn name
1443 ispecs <- lookupInsts thing
1444 return (thing, fixity, ispecs)
1446 lookupInsts :: TyThing -> TcM [Instance]
1447 lookupInsts (AClass cls)
1448 = do { inst_envs <- tcGetInstEnvs
1449 ; return (classInstances inst_envs cls) }
1451 lookupInsts (ATyCon tc)
1452 = do { (pkg_ie, home_ie) <- tcGetInstEnvs
1453 -- Load all instances for all classes that are
1454 -- in the type environment (which are all the ones
1455 -- we've seen in any interface file so far)
1456 ; return [ ispec -- Search all
1457 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1458 , let dfun = instanceDFunId ispec
1461 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1462 tc_name = tyConName tc
1464 lookupInsts _ = return []
1466 loadUnqualIfaces :: InteractiveContext -> TcM ()
1467 -- Load the home module for everything that is in scope unqualified
1468 -- This is so that we can accurately report the instances for
1470 loadUnqualIfaces ictxt
1472 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1474 unqual_mods = [ nameModule name
1475 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1476 let name = gre_name gre,
1477 not (isInternalName name),
1478 isTcOcc (nameOccName name), -- Types and classes only
1479 unQualOK gre ] -- In scope unqualified
1480 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1484 %************************************************************************
1488 %************************************************************************
1491 rnDump :: SDoc -> TcRn ()
1492 -- Dump, with a banner, if -ddump-rn
1493 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1495 tcDump :: TcGblEnv -> TcRn ()
1497 = do { dflags <- getDOpts ;
1499 -- Dump short output if -ddump-types or -ddump-tc
1500 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1501 (dumpTcRn short_dump) ;
1503 -- Dump bindings if -ddump-tc
1504 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1507 short_dump = pprTcGblEnv env
1508 full_dump = pprLHsBinds (tcg_binds env)
1509 -- NB: foreign x-d's have undefined's in their types;
1510 -- hence can't show the tc_fords
1512 tcCoreDump :: ModGuts -> TcM ()
1514 = do { dflags <- getDOpts ;
1515 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1516 (dumpTcRn (pprModGuts mod_guts)) ;
1518 -- Dump bindings if -ddump-tc
1519 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1521 full_dump = pprCoreBindings (mg_binds mod_guts)
1523 -- It's unpleasant having both pprModGuts and pprModDetails here
1524 pprTcGblEnv :: TcGblEnv -> SDoc
1525 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1527 tcg_fam_insts = fam_insts,
1529 tcg_imports = imports })
1530 = vcat [ ppr_types insts type_env
1531 , ppr_tycons fam_insts type_env
1533 , ppr_fam_insts fam_insts
1534 , vcat (map ppr rules)
1535 , ppr_gen_tycons (typeEnvTyCons type_env)
1536 , ptext (sLit "Dependent modules:") <+>
1537 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1538 , ptext (sLit "Dependent packages:") <+>
1539 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1540 where -- The two uses of sortBy are just to reduce unnecessary
1541 -- wobbling in testsuite output
1542 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1543 = (mod_name1 `stableModuleNameCmp` mod_name2)
1545 (is_boot1 `compare` is_boot2)
1547 pprModGuts :: ModGuts -> SDoc
1548 pprModGuts (ModGuts { mg_types = type_env,
1550 = vcat [ ppr_types [] type_env,
1553 ppr_types :: [Instance] -> TypeEnv -> SDoc
1554 ppr_types insts type_env
1555 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1557 dfun_ids = map instanceDFunId insts
1558 ids = [id | id <- typeEnvIds type_env, want_sig id]
1559 want_sig id | opt_PprStyle_Debug = True
1560 | otherwise = isLocalId id &&
1561 isExternalName (idName id) &&
1562 not (id `elem` dfun_ids)
1563 -- isLocalId ignores data constructors, records selectors etc.
1564 -- The isExternalName ignores local dictionary and method bindings
1565 -- that the type checker has invented. Top-level user-defined things
1566 -- have External names.
1568 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1569 ppr_tycons fam_insts type_env
1570 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1572 fi_tycons = map famInstTyCon fam_insts
1573 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1574 want_tycon tycon | opt_PprStyle_Debug = True
1575 | otherwise = not (isImplicitTyCon tycon) &&
1576 isExternalName (tyConName tycon) &&
1577 not (tycon `elem` fi_tycons)
1579 ppr_insts :: [Instance] -> SDoc
1580 ppr_insts [] = empty
1581 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1583 ppr_fam_insts :: [FamInst] -> SDoc
1584 ppr_fam_insts [] = empty
1585 ppr_fam_insts fam_insts =
1586 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1588 ppr_sigs :: [Var] -> SDoc
1590 -- Print type signatures; sort by OccName
1591 = vcat (map ppr_sig (sortLe le_sig ids))
1593 le_sig id1 id2 = getOccName id1 <= getOccName id2
1594 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1596 ppr_tydecls :: [TyCon] -> SDoc
1598 -- Print type constructor info; sort by OccName
1599 = vcat (map ppr_tycon (sortLe le_sig tycons))
1601 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1603 | isCoercionTyCon tycon
1604 = sep [ptext (sLit "coercion") <+> ppr tycon <+> ppr tvs
1605 , nest 2 (dcolon <+> pprEqPred (coercionKind (mkTyConApp tycon (mkTyVarTys tvs))))]
1606 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1608 tvs = take (tyConArity tycon) alphaTyVars
1610 ppr_rules :: [CoreRule] -> SDoc
1611 ppr_rules [] = empty
1612 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1613 nest 4 (pprRules rs),
1616 ppr_gen_tycons :: [TyCon] -> SDoc
1617 ppr_gen_tycons [] = empty
1618 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1619 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]