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 )
39 import TcType ( tidyTopType )
75 import TcType ( tyClsNamesOfDFunHead )
76 import Inst ( tcGetInstEnvs )
77 import Data.List ( sortBy )
80 import TcType ( isUnitTy, isTauTy )
81 import CoreUtils( mkPiTypes )
89 import TidyPgm ( globaliseAndTidyId )
90 import TysWiredIn ( unitTy, mkListTy )
100 #include "HsVersions.h"
103 %************************************************************************
105 Typecheck and rename a module
107 %************************************************************************
113 -> Bool -- True <=> save renamed syntax
114 -> Located (HsModule RdrName)
115 -> IO (Messages, Maybe TcGblEnv)
117 tcRnModule hsc_env hsc_src save_rn_syntax
118 (L loc (HsModule maybe_mod export_ies
119 import_decls local_decls mod_deprec
121 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
123 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
124 this_mod = case maybe_mod of
125 Nothing -> mAIN -- 'module M where' is omitted
126 Just (L _ mod) -> mkModule this_pkg mod } ;
129 initTc hsc_env hsc_src save_rn_syntax this_mod $
131 do { -- Deal with imports;
132 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
133 setGblEnv tcg_env $ do {
135 -- Load the hi-boot interface for this module, if any
136 -- We do this now so that the boot_names can be passed
137 -- to tcTyAndClassDecls, because the boot_names are
138 -- automatically considered to be loop breakers
140 -- Do this *after* tcRnImports, so that we know whether
141 -- a module that we import imports us; and hence whether to
142 -- look for a hi-boot file
143 boot_iface <- tcHiBootIface hsc_src this_mod ;
145 -- Rename and type check the declarations
146 traceRn (text "rn1a") ;
147 tcg_env <- if isHsBoot hsc_src then
148 tcRnHsBootDecls local_decls
150 tcRnSrcDecls boot_iface local_decls ;
151 setGblEnv tcg_env $ do {
153 -- Report the use of any deprecated things
154 -- We do this *before* processsing the export list so
155 -- that we don't bleat about re-exporting a deprecated
156 -- thing (especially via 'module Foo' export item)
157 -- That is, only uses in the *body* of the module are complained about
158 traceRn (text "rn3") ;
159 failIfErrsM ; -- finishWarnings crashes sometimes
160 -- as a result of typechecker repairs (e.g. unboundNames)
161 tcg_env <- finishWarnings (hsc_dflags hsc_env) mod_deprec tcg_env ;
163 -- Process the export list
164 traceRn (text "rn4a: before exports");
165 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
166 traceRn (text "rn4b: after exportss") ;
168 -- Check that main is exported (must be after rnExports)
169 checkMainExported tcg_env ;
171 -- Compare the hi-boot iface (if any) with the real thing
172 -- Must be done after processing the exports
173 tcg_env <- checkHiBootIface tcg_env boot_iface ;
175 -- The new type env is already available to stuff slurped from
176 -- interface files, via TcEnv.updateGlobalTypeEnv
177 -- It's important that this includes the stuff in checkHiBootIface,
178 -- because the latter might add new bindings for boot_dfuns,
179 -- which may be mentioned in imported unfoldings
181 -- Don't need to rename the Haddock documentation,
182 -- it's not parsed by GHC anymore.
183 tcg_env <- return (tcg_env { tcg_doc_hdr = maybe_doc_hdr }) ;
185 -- Report unused names
186 reportUnusedNames export_ies tcg_env ;
188 -- Dump output and return
195 %************************************************************************
199 %************************************************************************
202 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
203 tcRnImports hsc_env this_mod import_decls
204 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
206 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
207 ; dep_mods = imp_dep_mods imports
209 -- We want instance declarations from all home-package
210 -- modules below this one, including boot modules, except
211 -- ourselves. The 'except ourselves' is so that we don't
212 -- get the instances from this module's hs-boot file
213 ; want_instances :: ModuleName -> Bool
214 ; want_instances mod = mod `elemUFM` dep_mods
215 && mod /= moduleName this_mod
216 ; (home_insts, home_fam_insts) = hptInstances hsc_env
220 -- Record boot-file info in the EPS, so that it's
221 -- visible to loadHiBootInterface in tcRnSrcDecls,
222 -- and any other incrementally-performed imports
223 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
225 -- Update the gbl env
226 ; updGblEnv ( \ gbl ->
228 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
229 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
230 tcg_rn_imports = rn_imports,
231 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
232 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
237 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
238 -- Fail if there are any errors so far
239 -- The error printing (if needed) takes advantage
240 -- of the tcg_env we have now set
241 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
244 -- Load any orphan-module and family instance-module
245 -- interfaces, so that their rules and instance decls will be
247 ; loadOrphanModules (imp_orphs imports) False
248 ; loadOrphanModules (imp_finsts imports) True
250 -- Check type-familily consistency
251 ; traceRn (text "rn1: checking family instance consistency")
252 ; let { dir_imp_mods = moduleEnvKeys
255 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
261 %************************************************************************
263 Type-checking external-core modules
265 %************************************************************************
268 tcRnExtCore :: HscEnv
270 -> IO (Messages, Maybe ModGuts)
271 -- Nothing => some error occurred
273 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
274 -- The decls are IfaceDecls; all names are original names
275 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
277 initTc hsc_env ExtCoreFile False this_mod $ do {
279 let { ldecls = map noLoc decls } ;
281 -- bring the type and class decls into scope
282 -- ToDo: check that this doesn't need to extract the val binds.
283 -- It seems that only the type and class decls need to be in scope below because
284 -- (a) tcTyAndClassDecls doesn't need the val binds, and
285 -- (b) tcExtCoreBindings doesn't need anything
286 -- (in fact, it might not even need to be in the scope of
287 -- this tcg_env at all)
288 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
289 tc_envs <- extendGlobalRdrEnvRn avails emptyFsEnv {- no fixity decls -} ;
291 setEnvs tc_envs $ do {
293 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
295 -- Dump trace of renaming part
296 rnDump (ppr rn_decls) ;
298 -- Typecheck them all together so that
299 -- any mutually recursive types are done right
300 -- Just discard the auxiliary bindings; they are generated
301 -- only for Haskell source code, and should already be in Core
302 (tcg_env, _aux_binds, _dm_ids) <- tcTyAndClassDecls emptyModDetails rn_decls ;
304 setGblEnv tcg_env $ do {
305 -- Make the new type env available to stuff slurped from interface files
307 -- Now the core bindings
308 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
312 bndrs = bindersOfBinds core_binds ;
313 my_exports = map (Avail . idName) bndrs ;
314 -- ToDo: export the data types also?
317 extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
319 mod_guts = ModGuts { mg_module = this_mod,
321 mg_used_names = emptyNameSet, -- ToDo: compute usage
322 mg_dir_imps = emptyModuleEnv, -- ??
323 mg_deps = noDependencies, -- ??
324 mg_exports = my_exports,
325 mg_types = final_type_env,
326 mg_insts = tcg_insts tcg_env,
327 mg_fam_insts = tcg_fam_insts tcg_env,
328 mg_inst_env = tcg_inst_env tcg_env,
329 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
332 mg_binds = core_binds,
335 mg_rdr_env = emptyGlobalRdrEnv,
336 mg_fix_env = emptyFixityEnv,
337 mg_warns = NoWarnings,
338 mg_foreign = NoStubs,
339 mg_hpc_info = emptyHpcInfo False,
340 mg_modBreaks = emptyModBreaks,
341 mg_vect_info = noVectInfo
344 tcCoreDump mod_guts ;
349 mkFakeGroup :: [LTyClDecl a] -> HsGroup a
350 mkFakeGroup decls -- Rather clumsy; lots of unused fields
351 = emptyRdrGroup { hs_tyclds = decls }
355 %************************************************************************
357 Type-checking the top level of a module
359 %************************************************************************
362 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
363 -- Returns the variables free in the decls
364 -- Reason: solely to report unused imports and bindings
365 tcRnSrcDecls boot_iface decls
366 = do { -- Do all the declarations
367 (tc_envs, lie) <- getConstraints $ tc_rn_src_decls boot_iface decls ;
368 ; traceTc "Tc8" empty ;
372 -- Finish simplifying class constraints
374 -- simplifyTop deals with constant or ambiguous InstIds.
375 -- How could there be ambiguous ones? They can only arise if a
376 -- top-level decl falls under the monomorphism restriction
377 -- and no subsequent decl instantiates its type.
379 -- We do this after checkMain, so that we use the type info
380 -- thaat checkMain adds
382 -- We do it with both global and local env in scope:
383 -- * the global env exposes the instances to simplifyTop
384 -- * the local env exposes the local Ids to simplifyTop,
385 -- so that we get better error messages (monomorphism restriction)
386 new_ev_binds <- simplifyTop lie ;
387 traceTc "Tc9" empty ;
389 failIfErrsM ; -- Don't zonk if there have been errors
390 -- It's a waste of time; and we may get debug warnings
391 -- about strangely-typed TyCons!
393 -- Zonk the final code. This must be done last.
394 -- Even simplifyTop may do some unification.
395 -- This pass also warns about missing type signatures
396 let { (tcg_env, _) = tc_envs
397 ; TcGblEnv { tcg_type_env = type_env,
400 tcg_ev_binds = cur_ev_binds,
402 tcg_fords = fords } = tcg_env
403 ; all_ev_binds = cur_ev_binds `unionBags` new_ev_binds } ;
405 (bind_ids, ev_binds', binds', fords', rules')
406 <- zonkTopDecls all_ev_binds binds sig_ns rules fords ;
408 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
409 ; tcg_env' = tcg_env { tcg_binds = binds',
410 tcg_ev_binds = ev_binds',
412 tcg_fords = fords' } } ;
414 setGlobalTypeEnv tcg_env' final_type_env
417 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
418 -- Loops around dealing with each top level inter-splice group
419 -- in turn, until it's dealt with the entire module
420 tc_rn_src_decls boot_details ds
421 = do { (first_group, group_tail) <- findSplice ds ;
422 -- If ds is [] we get ([], Nothing)
424 -- Deal with decls up to, but not including, the first splice
425 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
426 -- rnTopSrcDecls fails if there are any errors
428 (tcg_env, tcl_env) <- setGblEnv tcg_env $
429 tcTopSrcDecls boot_details rn_decls ;
431 -- If there is no splice, we're nearly done
432 setEnvs (tcg_env, tcl_env) $
434 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
435 return (tcg_env, tcl_env)
439 -- There shouldn't be a splice
440 Just (SpliceDecl {}, _) -> do {
441 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
443 -- If there's a splice, we must carry on
444 Just (SpliceDecl splice_expr _, rest_ds) -> do {
446 -- Rename the splice expression, and get its supporting decls
447 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
448 -- checkNoErrs: don't typecheck if renaming failed
449 rnDump (ppr rn_splice_expr) ;
451 -- Execute the splice
452 spliced_decls <- tcSpliceDecls rn_splice_expr ;
454 -- Glue them on the front of the remaining decls and loop
455 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
456 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
461 %************************************************************************
463 Compiling hs-boot source files, and
464 comparing the hi-boot interface with the real thing
466 %************************************************************************
469 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
470 tcRnHsBootDecls decls
471 = do { (first_group, group_tail) <- findSplice decls
473 -- Rename the declarations
474 ; (tcg_env, HsGroup {
475 hs_tyclds = tycl_decls,
476 hs_instds = inst_decls,
477 hs_derivds = deriv_decls,
478 hs_fords = for_decls,
479 hs_defds = def_decls,
480 hs_ruleds = rule_decls,
482 hs_valds = val_binds }) <- rnTopSrcDecls first_group
483 ; (gbl_env, lie) <- getConstraints $ setGblEnv tcg_env $ do {
486 -- Check for illegal declarations
488 Just (SpliceDecl d _, _) -> badBootDecl "splice" d
490 ; mapM_ (badBootDecl "foreign") for_decls
491 ; mapM_ (badBootDecl "default") def_decls
492 ; mapM_ (badBootDecl "rule") rule_decls
494 -- Typecheck type/class decls
495 ; traceTc "Tc2" empty
496 ; (tcg_env, aux_binds, dm_ids)
497 <- tcTyAndClassDecls emptyModDetails tycl_decls
498 ; setGblEnv tcg_env $
499 tcExtendIdEnv dm_ids $ do {
501 -- Typecheck instance decls
502 -- Family instance declarations are rejected here
503 ; traceTc "Tc3" empty
504 ; (tcg_env, inst_infos, _deriv_binds)
505 <- tcInstDecls1 tycl_decls inst_decls deriv_decls
506 ; setGblEnv tcg_env $ do {
508 -- Typecheck value declarations
509 ; traceTc "Tc5" empty
510 ; val_ids <- tcHsBootSigs val_binds
513 -- No simplification or zonking to do
514 ; traceTc "Tc7a" empty
515 ; gbl_env <- getGblEnv
517 -- Make the final type-env
518 -- Include the dfun_ids so that their type sigs
519 -- are written into the interface file.
520 -- And similarly the aux_ids from aux_binds
521 ; let { type_env0 = tcg_type_env gbl_env
522 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
523 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
524 ; type_env3 = extendTypeEnvWithIds type_env2 aux_ids
525 ; dfun_ids = map iDFunId inst_infos
526 ; aux_ids = case aux_binds of
527 ValBindsOut _ sigs -> [id | L _ (IdSig id) <- sigs]
528 _ -> panic "tcRnHsBoodDecls"
531 ; setGlobalTypeEnv gbl_env type_env3
533 ; traceTc "boot" (ppr lie); return gbl_env }
535 badBootDecl :: String -> Located decl -> TcM ()
536 badBootDecl what (L loc _)
537 = addErrAt loc (char 'A' <+> text what
538 <+> ptext (sLit "declaration is not (currently) allowed in a hs-boot file"))
541 Once we've typechecked the body of the module, we want to compare what
542 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
545 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
546 -- Compare the hi-boot file for this module (if there is one)
547 -- with the type environment we've just come up with
548 -- In the common case where there is no hi-boot file, the list
549 -- of boot_names is empty.
551 -- The bindings we return give bindings for the dfuns defined in the
552 -- hs-boot file, such as $fbEqT = $fEqT
555 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
556 tcg_insts = local_insts,
557 tcg_type_env = local_type_env, tcg_exports = local_exports })
558 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
559 md_types = boot_type_env, md_exports = boot_exports })
560 | isHsBoot hs_src -- Current module is already a hs-boot file!
564 = do { traceTc "checkHiBootIface" $ vcat
565 [ ppr boot_type_env, ppr boot_insts, ppr boot_exports]
567 -- Check the exports of the boot module, one by one
568 ; mapM_ check_export boot_exports
570 -- Check for no family instances
571 ; unless (null boot_fam_insts) $
572 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
573 "instances in boot files yet...")
574 -- FIXME: Why? The actual comparison is not hard, but what would
575 -- be the equivalent to the dfun bindings returned for class
576 -- instances? We can't easily equate tycons...
578 -- Check instance declarations
579 ; mb_dfun_prs <- mapM check_inst boot_insts
580 ; let dfun_prs = catMaybes mb_dfun_prs
581 boot_dfuns = map fst dfun_prs
582 dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun)
583 | (boot_dfun, dfun) <- dfun_prs ]
584 type_env' = extendTypeEnvWithIds local_type_env boot_dfuns
585 tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
588 ; setGlobalTypeEnv tcg_env' type_env' }
589 -- Update the global type env *including* the knot-tied one
590 -- so that if the source module reads in an interface unfolding
591 -- mentioning one of the dfuns from the boot module, then it
592 -- can "see" that boot dfun. See Trac #4003
594 check_export boot_avail -- boot_avail is exported by the boot iface
595 | name `elem` dfun_names = return ()
596 | isWiredInName name = return () -- No checking for wired-in names. In particular,
597 -- 'error' is handled by a rather gross hack
598 -- (see comments in GHC.Err.hs-boot)
600 -- Check that the actual module exports the same thing
601 | not (null missing_names)
602 = addErrAt (nameSrcSpan (head missing_names))
603 (missingBootThing (head missing_names) "exported by")
605 -- If the boot module does not *define* the thing, we are done
606 -- (it simply re-exports it, and names match, so nothing further to do)
607 | isNothing mb_boot_thing = return ()
609 -- Check that the actual module also defines the thing, and
610 -- then compare the definitions
611 | Just real_thing <- lookupTypeEnv local_type_env name,
612 Just boot_thing <- mb_boot_thing
613 = when (not (checkBootDecl boot_thing real_thing))
614 $ addErrAt (nameSrcSpan (getName boot_thing))
615 (let boot_decl = tyThingToIfaceDecl
616 (fromJust mb_boot_thing)
617 real_decl = tyThingToIfaceDecl real_thing
618 in bootMisMatch real_thing boot_decl real_decl)
621 = addErrTc (missingBootThing name "defined in")
623 name = availName boot_avail
624 mb_boot_thing = lookupTypeEnv boot_type_env name
625 missing_names = case lookupNameEnv local_export_env name of
627 Just avail -> availNames boot_avail `minusList` availNames avail
629 dfun_names = map getName boot_insts
631 local_export_env :: NameEnv AvailInfo
632 local_export_env = availsToNameEnv local_exports
634 check_inst :: Instance -> TcM (Maybe (Id, Id))
635 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
637 = case [dfun | inst <- local_insts,
638 let dfun = instanceDFunId inst,
639 idType dfun `tcEqType` boot_inst_ty ] of
640 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
641 (dfun:_) -> return (Just (local_boot_dfun, dfun))
643 boot_dfun = instanceDFunId boot_inst
644 boot_inst_ty = idType boot_dfun
645 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
648 -- This has to compare the TyThing from the .hi-boot file to the TyThing
649 -- in the current source file. We must be careful to allow alpha-renaming
650 -- where appropriate, and also the boot declaration is allowed to omit
651 -- constructors and class methods.
653 -- See rnfail055 for a good test of this stuff.
655 checkBootDecl :: TyThing -> TyThing -> Bool
657 checkBootDecl (AnId id1) (AnId id2)
659 (idType id1 `tcEqType` idType id2)
661 checkBootDecl (ATyCon tc1) (ATyCon tc2)
662 = checkBootTyCon tc1 tc2
664 checkBootDecl (AClass c1) (AClass c2)
666 (clas_tyvars1, clas_fds1, sc_theta1, _, ats1, op_stuff1)
667 = classExtraBigSig c1
668 (clas_tyvars2, clas_fds2, sc_theta2, _, ats2, op_stuff2)
669 = classExtraBigSig c2
671 env0 = mkRnEnv2 emptyInScopeSet
672 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
674 eqSig (id1, def_meth1) (id2, def_meth2)
675 = idName id1 == idName id2 &&
676 tcEqTypeX env op_ty1 op_ty2 &&
677 def_meth1 == def_meth2
679 (_, rho_ty1) = splitForAllTys (idType id1)
680 op_ty1 = funResultTy rho_ty1
681 (_, rho_ty2) = splitForAllTys (idType id2)
682 op_ty2 = funResultTy rho_ty2
684 eqFD (as1,bs1) (as2,bs2) =
685 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
686 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
688 same_kind tv1 tv2 = eqKind (tyVarKind tv1) (tyVarKind tv2)
690 eqListBy same_kind clas_tyvars1 clas_tyvars2 &&
691 -- Checks kind of class
692 eqListBy eqFD clas_fds1 clas_fds2 &&
693 (null sc_theta1 && null op_stuff1 && null ats1
694 || -- Above tests for an "abstract" class
695 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
696 eqListBy eqSig op_stuff1 op_stuff2 &&
697 eqListBy checkBootTyCon ats1 ats2)
699 checkBootDecl (ADataCon dc1) (ADataCon _)
700 = pprPanic "checkBootDecl" (ppr dc1)
702 checkBootDecl _ _ = False -- probably shouldn't happen
705 checkBootTyCon :: TyCon -> TyCon -> Bool
706 checkBootTyCon tc1 tc2
707 | not (eqKind (tyConKind tc1) (tyConKind tc2))
708 = False -- First off, check the kind
710 | isSynTyCon tc1 && isSynTyCon tc2
712 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
713 env = rnBndrs2 env0 tvs1 tvs2
715 eqSynRhs SynFamilyTyCon SynFamilyTyCon
717 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
718 = tcEqTypeX env t1 t2
721 equalLength tvs1 tvs2 &&
722 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
724 | isAlgTyCon tc1 && isAlgTyCon tc2
726 eqKind (tyConKind tc1) (tyConKind tc2) &&
727 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2) &&
728 eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
730 | isForeignTyCon tc1 && isForeignTyCon tc2
731 = eqKind (tyConKind tc1) (tyConKind tc2) &&
732 tyConExtName tc1 == tyConExtName tc2
736 env0 = mkRnEnv2 emptyInScopeSet
738 eqAlgRhs AbstractTyCon _ = True
739 eqAlgRhs DataFamilyTyCon{} DataFamilyTyCon{} = True
740 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
741 eqListBy eqCon (data_cons tc1) (data_cons tc2)
742 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
743 eqCon (data_con tc1) (data_con tc2)
747 = dataConName c1 == dataConName c2
748 && dataConIsInfix c1 == dataConIsInfix c2
749 && dataConStrictMarks c1 == dataConStrictMarks c2
750 && dataConFieldLabels c1 == dataConFieldLabels c2
751 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
752 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
753 env = rnBndrs2 env0 tvs1 tvs2
755 equalLength tvs1 tvs2 &&
756 eqListBy (tcEqPredX env)
757 (dataConEqTheta c1 ++ dataConDictTheta c1)
758 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
759 eqListBy (tcEqTypeX env)
760 (dataConOrigArgTys c1)
761 (dataConOrigArgTys c2)
764 missingBootThing :: Name -> String -> SDoc
765 missingBootThing name what
766 = ppr name <+> ptext (sLit "is exported by the hs-boot file, but not")
767 <+> text what <+> ptext (sLit "the module")
769 bootMisMatch :: TyThing -> IfaceDecl -> IfaceDecl -> SDoc
770 bootMisMatch thing boot_decl real_decl
771 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
772 ptext (sLit "Main module:") <+> ppr real_decl,
773 ptext (sLit "Boot file: ") <+> ppr boot_decl]
775 instMisMatch :: Instance -> SDoc
778 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
782 %************************************************************************
784 Type-checking the top level of a module
786 %************************************************************************
788 tcRnGroup takes a bunch of top-level source-code declarations, and
790 * gets supporting declarations from interface files
793 * and augments the TcGblEnv with the results
795 In Template Haskell it may be called repeatedly for each group of
796 declarations. It expects there to be an incoming TcGblEnv in the
797 monad; it augments it and returns the new TcGblEnv.
800 ------------------------------------------------
801 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
802 -- Fails if there are any errors
804 = do { -- Rename the source decls
805 traceTc "rn12" empty ;
806 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
807 traceTc "rn13" empty ;
809 -- save the renamed syntax, if we want it
811 | Just grp <- tcg_rn_decls tcg_env
812 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
816 -- Dump trace of renaming part
817 rnDump (ppr rn_decls) ;
819 return (tcg_env', rn_decls)
822 ------------------------------------------------
823 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
824 tcTopSrcDecls boot_details
825 (HsGroup { hs_tyclds = tycl_decls,
826 hs_instds = inst_decls,
827 hs_derivds = deriv_decls,
828 hs_fords = foreign_decls,
829 hs_defds = default_decls,
830 hs_annds = annotation_decls,
831 hs_ruleds = rule_decls,
832 hs_valds = val_binds })
833 = do { -- Type-check the type and class decls, and all imported decls
834 -- The latter come in via tycl_decls
835 traceTc "Tc2" empty ;
837 (tcg_env, aux_binds, dm_ids) <- tcTyAndClassDecls boot_details tycl_decls ;
838 -- If there are any errors, tcTyAndClassDecls fails here
841 tcExtendIdEnv dm_ids $ do {
843 -- Source-language instances, including derivings,
844 -- and import the supporting declarations
845 traceTc "Tc3" empty ;
846 (tcg_env, inst_infos, deriv_binds)
847 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
848 setGblEnv tcg_env $ do {
850 -- Foreign import declarations next.
851 traceTc "Tc4" empty ;
852 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
853 tcExtendGlobalValEnv fi_ids $ do {
855 -- Default declarations
856 traceTc "Tc4a" empty ;
857 default_tys <- tcDefaults default_decls ;
858 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
860 -- Now GHC-generated derived bindings, generics, and selectors
861 -- Do not generate warnings from compiler-generated code;
862 -- hence the use of discardWarnings
863 (tc_aux_binds, tcl_env) <- discardWarnings (tcTopBinds aux_binds) ;
864 (tc_deriv_binds, tcl_env) <- setLclTypeEnv tcl_env $
865 discardWarnings (tcTopBinds deriv_binds) ;
867 -- Value declarations next
868 traceTc "Tc5" empty ;
869 (tc_val_binds, tcl_env) <- setLclTypeEnv tcl_env $
870 tcTopBinds val_binds;
872 setLclTypeEnv tcl_env $ do { -- Environment doesn't change now
874 -- Second pass over class and instance declarations,
875 traceTc "Tc6" empty ;
876 inst_binds <- tcInstDecls2 tycl_decls inst_infos ;
879 traceTc "Tc7" empty ;
880 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
883 annotations <- tcAnnotations annotation_decls ;
886 rules <- tcRules rule_decls ;
889 traceTc "Tc7a" empty ;
890 tcg_env <- getGblEnv ;
891 let { all_binds = tc_val_binds `unionBags`
892 tc_deriv_binds `unionBags`
893 tc_aux_binds `unionBags`
894 inst_binds `unionBags`
897 ; sig_names = mkNameSet (collectHsValBinders val_binds)
898 `minusNameSet` getTypeSigNames val_binds
900 -- Extend the GblEnv with the (as yet un-zonked)
901 -- bindings, rules, foreign decls
902 ; tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds
903 , tcg_sigs = tcg_sigs tcg_env `unionNameSets` sig_names
904 , tcg_rules = tcg_rules tcg_env ++ rules
905 , tcg_anns = tcg_anns tcg_env ++ annotations
906 , tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
907 return (tcg_env', tcl_env)
912 %************************************************************************
916 %************************************************************************
919 checkMain :: TcM TcGblEnv
920 -- If we are in module Main, check that 'main' is defined.
922 = do { tcg_env <- getGblEnv ;
924 check_main dflags tcg_env
927 check_main :: DynFlags -> TcGblEnv -> TcM TcGblEnv
928 check_main dflags tcg_env
930 = traceTc "checkMain not" (ppr main_mod <+> ppr mod) >>
934 = do { mb_main <- lookupGlobalOccRn_maybe main_fn
935 -- Check that 'main' is in scope
936 -- It might be imported from another module!
938 Nothing -> do { traceTc "checkMain fail" (ppr main_mod <+> ppr main_fn)
943 { traceTc "checkMain found" (ppr main_mod <+> ppr main_fn)
944 ; let loc = srcLocSpan (getSrcLoc main_name)
945 ; ioTyCon <- tcLookupTyCon ioTyConName
946 ; res_ty <- newFlexiTyVarTy liftedTypeKind
948 <- addErrCtxt mainCtxt $
949 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
951 -- See Note [Root-main Id]
952 -- Construct the binding
953 -- :Main.main :: IO res_ty = runMainIO res_ty main
954 ; run_main_id <- tcLookupId runMainIOName
955 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
956 (mkVarOccFS (fsLit "main"))
957 (getSrcSpan main_name)
958 ; root_main_id = Id.mkExportedLocalId root_main_name
959 (mkTyConApp ioTyCon [res_ty])
960 ; co = mkWpTyApps [res_ty]
961 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
962 ; main_bind = mkVarBind root_main_id rhs }
964 ; return (tcg_env { tcg_main = Just main_name,
965 tcg_binds = tcg_binds tcg_env
967 tcg_dus = tcg_dus tcg_env
968 `plusDU` usesOnly (unitFV main_name)
969 -- Record the use of 'main', so that we don't
970 -- complain about it being defined but not used
974 mod = tcg_mod tcg_env
975 main_mod = mainModIs dflags
976 main_fn = getMainFun dflags
978 complain_no_main | ghcLink dflags == LinkInMemory = return ()
979 | otherwise = failWithTc noMainMsg
980 -- In interactive mode, don't worry about the absence of 'main'
981 -- In other modes, fail altogether, so that we don't go on
982 -- and complain a second time when processing the export list.
984 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
985 noMainMsg = ptext (sLit "The") <+> pp_main_fn
986 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
987 pp_main_fn = ppMainFn main_fn
989 ppMainFn :: RdrName -> SDoc
991 | main_fn == main_RDR_Unqual
992 = ptext (sLit "function") <+> quotes (ppr main_fn)
994 = ptext (sLit "main function") <+> quotes (ppr main_fn)
996 -- | Get the unqualified name of the function to use as the \"main\" for the main module.
997 -- Either returns the default name or the one configured on the command line with -main-is
998 getMainFun :: DynFlags -> RdrName
999 getMainFun dflags = case (mainFunIs dflags) of
1000 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
1001 Nothing -> main_RDR_Unqual
1003 checkMainExported :: TcGblEnv -> TcM ()
1004 checkMainExported tcg_env = do
1006 case tcg_main tcg_env of
1007 Nothing -> return () -- not the main module
1008 Just main_name -> do
1009 let main_mod = mainModIs dflags
1010 checkTc (main_name `elem` concatMap availNames (tcg_exports tcg_env)) $
1011 ptext (sLit "The") <+> ppMainFn (nameRdrName main_name) <+>
1012 ptext (sLit "is not exported by module") <+> quotes (ppr main_mod)
1017 The function that the RTS invokes is always :Main.main, which we call
1018 root_main_id. (Because GHC allows the user to have a module not
1019 called Main as the main module, we can't rely on the main function
1020 being called "Main.main". That's why root_main_id has a fixed module
1023 This is unusual: it's a LocalId whose Name has a Module from another
1024 module. Tiresomely, we must filter it out again in MkIface, les we
1025 get two defns for 'main' in the interface file!
1028 %*********************************************************
1032 %*********************************************************
1035 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
1036 setInteractiveContext hsc_env icxt thing_inside
1037 = let -- Initialise the tcg_inst_env with instances from all home modules.
1038 -- This mimics the more selective call to hptInstances in tcRnModule.
1039 (home_insts, home_fam_insts) = hptInstances hsc_env (\_ -> True)
1041 updGblEnv (\env -> env {
1042 tcg_rdr_env = ic_rn_gbl_env icxt,
1043 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
1044 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
1048 tcExtendGhciEnv (ic_tmp_ids icxt) $
1049 -- tcExtendGhciEnv does lots:
1050 -- - it extends the local type env (tcl_env) with the given Ids,
1051 -- - it extends the local rdr env (tcl_rdr) with the Names from
1053 -- - it adds the free tyvars of the Ids to the tcl_tyvars
1056 -- later ids in ic_tmp_ids must shadow earlier ones with the same
1057 -- OccName, and tcExtendIdEnv implements this behaviour.
1059 do { traceTc "setIC" (ppr (ic_tmp_ids icxt))
1067 -> InteractiveContext
1069 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1070 -- The returned [Id] is the list of new Ids bound by
1071 -- this statement. It can be used to extend the
1072 -- InteractiveContext via extendInteractiveContext.
1074 -- The returned TypecheckedHsExpr is of type IO [ () ],
1075 -- a list of the bound values, coerced to ().
1077 tcRnStmt hsc_env ictxt rdr_stmt
1078 = initTcPrintErrors hsc_env iNTERACTIVE $
1079 setInteractiveContext hsc_env ictxt $ do {
1081 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1082 (([rn_stmt], _), fvs) <- rnStmts GhciStmt [rdr_stmt] (return ((), emptyFVs)) ;
1083 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1085 rnDump (ppr rn_stmt) ;
1087 -- The real work is done here
1088 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1089 zonked_expr <- zonkTopLExpr tc_expr ;
1090 zonked_ids <- zonkTopBndrs bound_ids ;
1092 -- None of the Ids should be of unboxed type, because we
1093 -- cast them all to HValues in the end!
1094 mapM_ bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1096 traceTc "tcs 1" empty ;
1097 let { global_ids = map globaliseAndTidyId zonked_ids } ;
1098 -- Note [Interactively-bound Ids in GHCi]
1100 {- ---------------------------------------------
1101 At one stage I removed any shadowed bindings from the type_env;
1102 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1103 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1105 Prelude> let f n = n * 2 :: Int
1106 Prelude> fName <- runQ [| f |]
1107 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1109 Prelude> let f n = n * 3 :: Int
1110 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1111 In the last line we use 'fName', which resolves to the *first* 'f'
1112 in scope. If we delete it from the type env, GHCi crashes because
1113 it doesn't expect that.
1115 Hence this code is commented out
1117 -------------------------------------------------- -}
1119 dumpOptTcRn Opt_D_dump_tc
1120 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1121 text "Typechecked expr" <+> ppr zonked_expr]) ;
1123 return (global_ids, zonked_expr)
1126 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1127 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1130 Note [Interactively-bound Ids in GHCi]
1131 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1132 The Ids bound by previous Stmts in Template Haskell are currently
1134 b) with an Internal Name (not External)
1135 c) and a tidied type
1137 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1138 compile an expression using these ids later, the byte code
1139 generator will consider the occurrences to be free rather than
1142 (b) They retain their Internal names becuase we don't have a suitable
1143 Module to name them with. We could revisit this choice.
1145 (c) Their types are tidied. This is important, because :info may ask
1146 to look at them, and :info expects the things it looks up to have
1150 --------------------------------------------------------------------------
1151 Typechecking Stmts in GHCi
1153 Here is the grand plan, implemented in tcUserStmt
1155 What you type The IO [HValue] that hscStmt returns
1156 ------------- ------------------------------------
1157 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1160 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1163 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1164 [NB: result not printed] bindings: [it]
1166 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1167 result showable) bindings: [it]
1169 expr (of non-IO type,
1170 result not showable) ==> error
1174 ---------------------------
1175 type PlanResult = ([Id], LHsExpr Id)
1176 type Plan = TcM PlanResult
1178 runPlans :: [Plan] -> TcM PlanResult
1179 -- Try the plans in order. If one fails (by raising an exn), try the next.
1180 -- If one succeeds, take it.
1181 runPlans [] = panic "runPlans"
1183 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1185 --------------------
1186 mkPlan :: LStmt Name -> TcM PlanResult
1187 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1188 = do { uniq <- newUnique -- is treated very specially
1189 ; let fresh_it = itName uniq
1190 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1191 matches = [mkMatch [] expr emptyLocalBinds]
1192 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1193 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1194 (HsVar bindIOName) noSyntaxExpr
1195 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1196 (HsVar thenIOName) placeHolderType
1199 -- [it <- e; print it] but not if it::()
1201 -- [let it = e; print it]
1202 ; runPlans [ -- Plan A
1203 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1204 ; it_ty <- zonkTcType (idType it_id)
1205 ; when (isUnitTy it_ty) failM
1208 -- Plan B; a naked bind statment
1209 tcGhciStmts [bind_stmt],
1211 -- Plan C; check that the let-binding is typeable all by itself.
1212 -- If not, fail; if so, try to print it.
1213 -- The two-step process avoids getting two errors: one from
1214 -- the expression itself, and one from the 'print it' part
1215 -- This two-step story is very clunky, alas
1216 do { _ <- checkNoErrs (tcGhciStmts [let_stmt])
1217 --- checkNoErrs defeats the error recovery of let-bindings
1218 ; tcGhciStmts [let_stmt, print_it] }
1221 mkPlan stmt@(L loc (BindStmt {}))
1222 | [v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1223 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1224 (HsVar thenIOName) placeHolderType
1226 ; print_bind_result <- doptM Opt_PrintBindResult
1227 ; let print_plan = do
1228 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1229 ; v_ty <- zonkTcType (idType v_id)
1230 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1234 -- [stmt; print v] but not if v::()
1236 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1237 [tcGhciStmts [stmt]])
1241 = tcGhciStmts [stmt]
1243 ---------------------------
1244 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1246 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1247 ret_id <- tcLookupId returnIOName ; -- return @ IO
1249 ret_ty = mkListTy unitTy ;
1250 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1251 tc_io_stmts stmts = tcStmts GhciStmt tcDoStmt stmts io_ret_ty ;
1253 names = collectLStmtsBinders stmts ;
1255 -- mk_return builds the expression
1256 -- returnIO @ [()] [coerce () x, .., coerce () z]
1258 -- Despite the inconvenience of building the type applications etc,
1259 -- this *has* to be done in type-annotated post-typecheck form
1260 -- because we are going to return a list of *polymorphic* values
1261 -- coerced to type (). If we built a *source* stmt
1262 -- return [coerce x, ..., coerce z]
1263 -- then the type checker would instantiate x..z, and we wouldn't
1264 -- get their *polymorphic* values. (And we'd get ambiguity errs
1265 -- if they were overloaded, since they aren't applied to anything.)
1266 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1267 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1268 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1272 -- OK, we're ready to typecheck the stmts
1273 traceTc "TcRnDriver.tcGhciStmts: tc stmts" empty ;
1274 ((tc_stmts, ids), lie) <- getConstraints $ tc_io_stmts stmts $ \ _ ->
1275 mapM tcLookupId names ;
1276 -- Look up the names right in the middle,
1277 -- where they will all be in scope
1279 -- Simplify the context
1280 traceTc "TcRnDriver.tcGhciStmts: simplify ctxt" empty ;
1281 const_binds <- checkNoErrs (simplifyInteractive lie) ;
1282 -- checkNoErrs ensures that the plan fails if context redn fails
1284 traceTc "TcRnDriver.tcGhciStmts: done" empty ;
1285 return (ids, mkHsDictLet (EvBinds const_binds) $
1286 noLoc (HsDo GhciStmt tc_stmts (mk_return ids) io_ret_ty))
1291 tcRnExpr just finds the type of an expression
1295 -> InteractiveContext
1297 -> IO (Messages, Maybe Type)
1298 tcRnExpr hsc_env ictxt rdr_expr
1299 = initTcPrintErrors hsc_env iNTERACTIVE $
1300 setInteractiveContext hsc_env ictxt $ do {
1302 (rn_expr, _fvs) <- rnLExpr rdr_expr ;
1305 -- Now typecheck the expression;
1306 -- it might have a rank-2 type (e.g. :t runST)
1307 ((_tc_expr, res_ty), lie) <- getConstraints (tcInferRho rn_expr) ;
1308 ((qtvs, dicts, _), lie_top) <- getConstraints (simplifyInfer False {- No MR for now -}
1309 (tyVarsOfType res_ty) lie) ;
1310 _ <- simplifyInteractive lie_top ; -- Ignore the dicionary bindings
1312 let { all_expr_ty = mkForAllTys qtvs (mkPiTypes dicts res_ty) } ;
1313 zonkTcType all_expr_ty
1317 tcRnType just finds the kind of a type
1321 -> InteractiveContext
1323 -> IO (Messages, Maybe Kind)
1324 tcRnType hsc_env ictxt rdr_type
1325 = initTcPrintErrors hsc_env iNTERACTIVE $
1326 setInteractiveContext hsc_env ictxt $ do {
1328 rn_type <- rnLHsType doc rdr_type ;
1331 -- Now kind-check the type
1332 (_ty', kind) <- kcLHsType rn_type ;
1336 doc = ptext (sLit "In GHCi input")
1342 %************************************************************************
1344 More GHCi stuff, to do with browsing and getting info
1346 %************************************************************************
1350 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1351 -- a package module with an interface on disk. If neither of these is
1352 -- true, then the result will be an error indicating the interface
1353 -- could not be found.
1354 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1355 getModuleExports hsc_env mod
1358 checkMods = ic_toplev_scope ic ++ map fst (ic_exports ic)
1360 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1362 -- Get the export avail info and also load all orphan and family-instance
1363 -- modules. Finally, check that the family instances of all modules in the
1364 -- interactive context are consistent (these modules are in the second
1366 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1367 tcGetModuleExports mod directlyImpMods
1368 = do { let doc = ptext (sLit "context for compiling statements")
1369 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1371 -- Load any orphan-module and family instance-module
1372 -- interfaces, so their instances are visible.
1373 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1374 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1376 -- Check that the family instances of all directly loaded
1377 -- modules are consistent.
1378 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1380 ; ifaceExportNames (mi_exports iface)
1383 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1384 tcRnLookupRdrName hsc_env rdr_name
1385 = initTcPrintErrors hsc_env iNTERACTIVE $
1386 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1387 lookup_rdr_name rdr_name
1389 lookup_rdr_name :: RdrName -> TcM [Name]
1390 lookup_rdr_name rdr_name = do {
1391 -- If the identifier is a constructor (begins with an
1392 -- upper-case letter), then we need to consider both
1393 -- constructor and type class identifiers.
1394 let { rdr_names = dataTcOccs rdr_name } ;
1396 -- results :: [Either Messages Name]
1397 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1399 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1400 -- The successful lookups will be (Just name)
1401 let { (warns_s, good_names) = unzip [ (msgs, name)
1402 | (msgs, Just name) <- results] ;
1403 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1405 -- Fail if nothing good happened, else add warnings
1406 if null good_names then
1407 -- No lookup succeeded, so
1408 -- pick the first error message and report it
1409 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1410 -- while the other is "X is not in scope",
1411 -- we definitely want the former; but we might pick the latter
1412 do { addMessages (head errs_s) ; failM }
1413 else -- Add deprecation warnings
1414 mapM_ addMessages warns_s ;
1420 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1421 tcRnLookupName hsc_env name
1422 = initTcPrintErrors hsc_env iNTERACTIVE $
1423 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1424 tcRnLookupName' name
1426 -- To look up a name we have to look in the local environment (tcl_lcl)
1427 -- as well as the global environment, which is what tcLookup does.
1428 -- But we also want a TyThing, so we have to convert:
1430 tcRnLookupName' :: Name -> TcRn TyThing
1431 tcRnLookupName' name = do
1432 tcthing <- tcLookup name
1434 AGlobal thing -> return thing
1435 ATcId{tct_id=id} -> return (AnId id)
1436 _ -> panic "tcRnLookupName'"
1438 tcRnGetInfo :: HscEnv
1440 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1442 -- Used to implement :info in GHCi
1444 -- Look up a RdrName and return all the TyThings it might be
1445 -- A capitalised RdrName is given to us in the DataName namespace,
1446 -- but we want to treat it as *both* a data constructor
1447 -- *and* as a type or class constructor;
1448 -- hence the call to dataTcOccs, and we return up to two results
1449 tcRnGetInfo hsc_env name
1450 = initTcPrintErrors hsc_env iNTERACTIVE $
1451 tcRnGetInfo' hsc_env name
1453 tcRnGetInfo' :: HscEnv
1455 -> TcRn (TyThing, Fixity, [Instance])
1456 tcRnGetInfo' hsc_env name
1457 = let ictxt = hsc_IC hsc_env in
1458 setInteractiveContext hsc_env ictxt $ do
1460 -- Load the interface for all unqualified types and classes
1461 -- That way we will find all the instance declarations
1462 -- (Packages have not orphan modules, and we assume that
1463 -- in the home package all relevant modules are loaded.)
1464 loadUnqualIfaces ictxt
1466 thing <- tcRnLookupName' name
1467 fixity <- lookupFixityRn name
1468 ispecs <- lookupInsts thing
1469 return (thing, fixity, ispecs)
1471 lookupInsts :: TyThing -> TcM [Instance]
1472 lookupInsts (AClass cls)
1473 = do { inst_envs <- tcGetInstEnvs
1474 ; return (classInstances inst_envs cls) }
1476 lookupInsts (ATyCon tc)
1477 = do { (pkg_ie, home_ie) <- tcGetInstEnvs
1478 -- Load all instances for all classes that are
1479 -- in the type environment (which are all the ones
1480 -- we've seen in any interface file so far)
1481 ; return [ ispec -- Search all
1482 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1483 , let dfun = instanceDFunId ispec
1486 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1487 tc_name = tyConName tc
1489 lookupInsts _ = return []
1491 loadUnqualIfaces :: InteractiveContext -> TcM ()
1492 -- Load the home module for everything that is in scope unqualified
1493 -- This is so that we can accurately report the instances for
1495 loadUnqualIfaces ictxt
1497 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1499 unqual_mods = [ nameModule name
1500 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1501 let name = gre_name gre,
1502 not (isInternalName name),
1503 isTcOcc (nameOccName name), -- Types and classes only
1504 unQualOK gre ] -- In scope unqualified
1505 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1508 %************************************************************************
1512 %************************************************************************
1515 rnDump :: SDoc -> TcRn ()
1516 -- Dump, with a banner, if -ddump-rn
1517 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1519 tcDump :: TcGblEnv -> TcRn ()
1521 = do { dflags <- getDOpts ;
1523 -- Dump short output if -ddump-types or -ddump-tc
1524 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1525 (dumpTcRn short_dump) ;
1527 -- Dump bindings if -ddump-tc
1528 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1531 short_dump = pprTcGblEnv env
1532 full_dump = pprLHsBinds (tcg_binds env)
1533 -- NB: foreign x-d's have undefined's in their types;
1534 -- hence can't show the tc_fords
1536 tcCoreDump :: ModGuts -> TcM ()
1538 = do { dflags <- getDOpts ;
1539 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1540 (dumpTcRn (pprModGuts mod_guts)) ;
1542 -- Dump bindings if -ddump-tc
1543 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1545 full_dump = pprCoreBindings (mg_binds mod_guts)
1547 -- It's unpleasant having both pprModGuts and pprModDetails here
1548 pprTcGblEnv :: TcGblEnv -> SDoc
1549 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1551 tcg_fam_insts = fam_insts,
1553 tcg_imports = imports })
1554 = vcat [ ppr_types insts type_env
1555 , ppr_tycons fam_insts type_env
1557 , ppr_fam_insts fam_insts
1558 , vcat (map ppr rules)
1559 , ppr_gen_tycons (typeEnvTyCons type_env)
1560 , ptext (sLit "Dependent modules:") <+>
1561 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1562 , ptext (sLit "Dependent packages:") <+>
1563 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1564 where -- The two uses of sortBy are just to reduce unnecessary
1565 -- wobbling in testsuite output
1566 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1567 = (mod_name1 `stableModuleNameCmp` mod_name2)
1569 (is_boot1 `compare` is_boot2)
1571 pprModGuts :: ModGuts -> SDoc
1572 pprModGuts (ModGuts { mg_types = type_env,
1574 = vcat [ ppr_types [] type_env,
1577 ppr_types :: [Instance] -> TypeEnv -> SDoc
1578 ppr_types insts type_env
1579 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1581 dfun_ids = map instanceDFunId insts
1582 ids = [id | id <- typeEnvIds type_env, want_sig id]
1583 want_sig id | opt_PprStyle_Debug = True
1584 | otherwise = isLocalId id &&
1585 isExternalName (idName id) &&
1586 not (id `elem` dfun_ids)
1587 -- isLocalId ignores data constructors, records selectors etc.
1588 -- The isExternalName ignores local dictionary and method bindings
1589 -- that the type checker has invented. Top-level user-defined things
1590 -- have External names.
1592 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1593 ppr_tycons fam_insts type_env
1594 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1596 fi_tycons = map famInstTyCon fam_insts
1597 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1598 want_tycon tycon | opt_PprStyle_Debug = True
1599 | otherwise = not (isImplicitTyCon tycon) &&
1600 isExternalName (tyConName tycon) &&
1601 not (tycon `elem` fi_tycons)
1603 ppr_insts :: [Instance] -> SDoc
1604 ppr_insts [] = empty
1605 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1607 ppr_fam_insts :: [FamInst] -> SDoc
1608 ppr_fam_insts [] = empty
1609 ppr_fam_insts fam_insts =
1610 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1612 ppr_sigs :: [Var] -> SDoc
1614 -- Print type signatures; sort by OccName
1615 = vcat (map ppr_sig (sortLe le_sig ids))
1617 le_sig id1 id2 = getOccName id1 <= getOccName id2
1618 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1620 ppr_tydecls :: [TyCon] -> SDoc
1622 -- Print type constructor info; sort by OccName
1623 = vcat (map ppr_tycon (sortLe le_sig tycons))
1625 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1627 | isCoercionTyCon tycon
1628 = sep [ptext (sLit "coercion") <+> ppr tycon <+> ppr tvs
1629 , nest 2 (dcolon <+> pprEqPred (coercionKind (mkTyConApp tycon (mkTyVarTys tvs))))]
1630 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1632 tvs = take (tyConArity tycon) alphaTyVars
1634 ppr_rules :: [CoreRule] -> SDoc
1635 ppr_rules [] = empty
1636 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1637 nest 2 (pprRules rs),
1640 ppr_gen_tycons :: [TyCon] -> SDoc
1641 ppr_gen_tycons [] = empty
1642 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1643 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]