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 ( orphNamesOfDFunHead )
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, _fvs) <- 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) <- captureConstraints $ 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,
401 tcg_imp_specs = imp_specs,
403 tcg_fords = fords } = tcg_env
404 ; all_ev_binds = cur_ev_binds `unionBags` new_ev_binds } ;
406 (bind_ids, ev_binds', binds', fords', imp_specs', rules')
407 <- zonkTopDecls all_ev_binds binds sig_ns rules imp_specs fords ;
409 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
410 ; tcg_env' = tcg_env { tcg_binds = binds',
411 tcg_ev_binds = ev_binds',
412 tcg_imp_specs = imp_specs',
414 tcg_fords = fords' } } ;
416 setGlobalTypeEnv tcg_env' final_type_env
419 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
420 -- Loops around dealing with each top level inter-splice group
421 -- in turn, until it's dealt with the entire module
422 tc_rn_src_decls boot_details ds
423 = do { (first_group, group_tail) <- findSplice ds ;
424 -- If ds is [] we get ([], Nothing)
426 -- Deal with decls up to, but not including, the first splice
427 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
428 -- rnTopSrcDecls fails if there are any errors
430 (tcg_env, tcl_env) <- setGblEnv tcg_env $
431 tcTopSrcDecls boot_details rn_decls ;
433 -- If there is no splice, we're nearly done
434 setEnvs (tcg_env, tcl_env) $
436 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
437 return (tcg_env, tcl_env)
441 -- There shouldn't be a splice
442 Just (SpliceDecl {}, _) -> do {
443 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
445 -- If there's a splice, we must carry on
446 Just (SpliceDecl splice_expr _, rest_ds) -> do {
448 -- Rename the splice expression, and get its supporting decls
449 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
450 -- checkNoErrs: don't typecheck if renaming failed
451 rnDump (ppr rn_splice_expr) ;
453 -- Execute the splice
454 spliced_decls <- tcSpliceDecls rn_splice_expr ;
456 -- Glue them on the front of the remaining decls and loop
457 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
458 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
463 %************************************************************************
465 Compiling hs-boot source files, and
466 comparing the hi-boot interface with the real thing
468 %************************************************************************
471 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
472 tcRnHsBootDecls decls
473 = do { (first_group, group_tail) <- findSplice decls
475 -- Rename the declarations
476 ; (tcg_env, HsGroup {
477 hs_tyclds = tycl_decls,
478 hs_instds = inst_decls,
479 hs_derivds = deriv_decls,
480 hs_fords = for_decls,
481 hs_defds = def_decls,
482 hs_ruleds = rule_decls,
484 hs_valds = val_binds }) <- rnTopSrcDecls first_group
485 ; (gbl_env, lie) <- captureConstraints $ setGblEnv tcg_env $ do {
488 -- Check for illegal declarations
490 Just (SpliceDecl d _, _) -> badBootDecl "splice" d
492 ; mapM_ (badBootDecl "foreign") for_decls
493 ; mapM_ (badBootDecl "default") def_decls
494 ; mapM_ (badBootDecl "rule") rule_decls
496 -- Typecheck type/class decls
497 ; traceTc "Tc2" empty
498 ; (tcg_env, aux_binds, dm_ids)
499 <- tcTyAndClassDecls emptyModDetails tycl_decls
500 ; setGblEnv tcg_env $
501 tcExtendIdEnv dm_ids $ do {
503 -- Typecheck instance decls
504 -- Family instance declarations are rejected here
505 ; traceTc "Tc3" empty
506 ; (tcg_env, inst_infos, _deriv_binds)
507 <- tcInstDecls1 (concat tycl_decls) inst_decls deriv_decls
509 ; setGblEnv tcg_env $ do {
511 -- Typecheck value declarations
512 ; traceTc "Tc5" empty
513 ; val_ids <- tcHsBootSigs val_binds
516 -- No simplification or zonking to do
517 ; traceTc "Tc7a" empty
518 ; gbl_env <- getGblEnv
520 -- Make the final type-env
521 -- Include the dfun_ids so that their type sigs
522 -- are written into the interface file.
523 -- And similarly the aux_ids from aux_binds
524 ; let { type_env0 = tcg_type_env gbl_env
525 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
526 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
527 ; type_env3 = extendTypeEnvWithIds type_env2 aux_ids
528 ; dfun_ids = map iDFunId inst_infos
529 ; aux_ids = case aux_binds of
530 ValBindsOut _ sigs -> [id | L _ (IdSig id) <- sigs]
531 _ -> panic "tcRnHsBoodDecls"
534 ; setGlobalTypeEnv gbl_env type_env3
536 ; traceTc "boot" (ppr lie); return gbl_env }
538 badBootDecl :: String -> Located decl -> TcM ()
539 badBootDecl what (L loc _)
540 = addErrAt loc (char 'A' <+> text what
541 <+> ptext (sLit "declaration is not (currently) allowed in a hs-boot file"))
544 Once we've typechecked the body of the module, we want to compare what
545 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
548 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
549 -- Compare the hi-boot file for this module (if there is one)
550 -- with the type environment we've just come up with
551 -- In the common case where there is no hi-boot file, the list
552 -- of boot_names is empty.
554 -- The bindings we return give bindings for the dfuns defined in the
555 -- hs-boot file, such as $fbEqT = $fEqT
558 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
559 tcg_insts = local_insts,
560 tcg_type_env = local_type_env, tcg_exports = local_exports })
561 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
562 md_types = boot_type_env, md_exports = boot_exports })
563 | isHsBoot hs_src -- Current module is already a hs-boot file!
567 = do { traceTc "checkHiBootIface" $ vcat
568 [ ppr boot_type_env, ppr boot_insts, ppr boot_exports]
570 -- Check the exports of the boot module, one by one
571 ; mapM_ check_export boot_exports
573 -- Check for no family instances
574 ; unless (null boot_fam_insts) $
575 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
576 "instances in boot files yet...")
577 -- FIXME: Why? The actual comparison is not hard, but what would
578 -- be the equivalent to the dfun bindings returned for class
579 -- instances? We can't easily equate tycons...
581 -- Check instance declarations
582 ; mb_dfun_prs <- mapM check_inst boot_insts
583 ; let dfun_prs = catMaybes mb_dfun_prs
584 boot_dfuns = map fst dfun_prs
585 dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun)
586 | (boot_dfun, dfun) <- dfun_prs ]
587 type_env' = extendTypeEnvWithIds local_type_env boot_dfuns
588 tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
591 ; setGlobalTypeEnv tcg_env' type_env' }
592 -- Update the global type env *including* the knot-tied one
593 -- so that if the source module reads in an interface unfolding
594 -- mentioning one of the dfuns from the boot module, then it
595 -- can "see" that boot dfun. See Trac #4003
597 check_export boot_avail -- boot_avail is exported by the boot iface
598 | name `elem` dfun_names = return ()
599 | isWiredInName name = return () -- No checking for wired-in names. In particular,
600 -- 'error' is handled by a rather gross hack
601 -- (see comments in GHC.Err.hs-boot)
603 -- Check that the actual module exports the same thing
604 | not (null missing_names)
605 = addErrAt (nameSrcSpan (head missing_names))
606 (missingBootThing (head missing_names) "exported by")
608 -- If the boot module does not *define* the thing, we are done
609 -- (it simply re-exports it, and names match, so nothing further to do)
610 | isNothing mb_boot_thing = return ()
612 -- Check that the actual module also defines the thing, and
613 -- then compare the definitions
614 | Just real_thing <- lookupTypeEnv local_type_env name,
615 Just boot_thing <- mb_boot_thing
616 = when (not (checkBootDecl boot_thing real_thing))
617 $ addErrAt (nameSrcSpan (getName boot_thing))
618 (let boot_decl = tyThingToIfaceDecl
619 (fromJust mb_boot_thing)
620 real_decl = tyThingToIfaceDecl real_thing
621 in bootMisMatch real_thing boot_decl real_decl)
624 = addErrTc (missingBootThing name "defined in")
626 name = availName boot_avail
627 mb_boot_thing = lookupTypeEnv boot_type_env name
628 missing_names = case lookupNameEnv local_export_env name of
630 Just avail -> availNames boot_avail `minusList` availNames avail
632 dfun_names = map getName boot_insts
634 local_export_env :: NameEnv AvailInfo
635 local_export_env = availsToNameEnv local_exports
637 check_inst :: Instance -> TcM (Maybe (Id, Id))
638 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
640 = case [dfun | inst <- local_insts,
641 let dfun = instanceDFunId inst,
642 idType dfun `tcEqType` boot_inst_ty ] of
643 [] -> do { traceTc "check_inst" (vcat [ text "local_insts" <+> vcat (map (ppr . idType . instanceDFunId) local_insts)
644 , text "boot_inst" <+> ppr boot_inst
645 , text "boot_inst_ty" <+> ppr boot_inst_ty
647 ; addErrTc (instMisMatch boot_inst); return Nothing }
648 (dfun:_) -> return (Just (local_boot_dfun, dfun))
650 boot_dfun = instanceDFunId boot_inst
651 boot_inst_ty = idType boot_dfun
652 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
655 -- This has to compare the TyThing from the .hi-boot file to the TyThing
656 -- in the current source file. We must be careful to allow alpha-renaming
657 -- where appropriate, and also the boot declaration is allowed to omit
658 -- constructors and class methods.
660 -- See rnfail055 for a good test of this stuff.
662 checkBootDecl :: TyThing -> TyThing -> Bool
664 checkBootDecl (AnId id1) (AnId id2)
666 (idType id1 `tcEqType` idType id2)
668 checkBootDecl (ATyCon tc1) (ATyCon tc2)
669 = checkBootTyCon tc1 tc2
671 checkBootDecl (AClass c1) (AClass c2)
673 (clas_tyvars1, clas_fds1, sc_theta1, _, ats1, op_stuff1)
674 = classExtraBigSig c1
675 (clas_tyvars2, clas_fds2, sc_theta2, _, ats2, op_stuff2)
676 = classExtraBigSig c2
678 env0 = mkRnEnv2 emptyInScopeSet
679 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
681 eqSig (id1, def_meth1) (id2, def_meth2)
682 = idName id1 == idName id2 &&
683 tcEqTypeX env op_ty1 op_ty2 &&
684 def_meth1 == def_meth2
686 (_, rho_ty1) = splitForAllTys (idType id1)
687 op_ty1 = funResultTy rho_ty1
688 (_, rho_ty2) = splitForAllTys (idType id2)
689 op_ty2 = funResultTy rho_ty2
691 eqFD (as1,bs1) (as2,bs2) =
692 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
693 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
695 same_kind tv1 tv2 = eqKind (tyVarKind tv1) (tyVarKind tv2)
697 eqListBy same_kind clas_tyvars1 clas_tyvars2 &&
698 -- Checks kind of class
699 eqListBy eqFD clas_fds1 clas_fds2 &&
700 (null sc_theta1 && null op_stuff1 && null ats1
701 || -- Above tests for an "abstract" class
702 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
703 eqListBy eqSig op_stuff1 op_stuff2 &&
704 eqListBy checkBootTyCon ats1 ats2)
706 checkBootDecl (ADataCon dc1) (ADataCon _)
707 = pprPanic "checkBootDecl" (ppr dc1)
709 checkBootDecl _ _ = False -- probably shouldn't happen
712 checkBootTyCon :: TyCon -> TyCon -> Bool
713 checkBootTyCon tc1 tc2
714 | not (eqKind (tyConKind tc1) (tyConKind tc2))
715 = False -- First off, check the kind
717 | isSynTyCon tc1 && isSynTyCon tc2
719 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
720 env = rnBndrs2 env0 tvs1 tvs2
722 eqSynRhs SynFamilyTyCon SynFamilyTyCon
724 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
725 = tcEqTypeX env t1 t2
728 equalLength tvs1 tvs2 &&
729 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
731 | isAlgTyCon tc1 && isAlgTyCon tc2
733 eqKind (tyConKind tc1) (tyConKind tc2) &&
734 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2) &&
735 eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
737 | isForeignTyCon tc1 && isForeignTyCon tc2
738 = eqKind (tyConKind tc1) (tyConKind tc2) &&
739 tyConExtName tc1 == tyConExtName tc2
743 env0 = mkRnEnv2 emptyInScopeSet
745 eqAlgRhs AbstractTyCon _ = True
746 eqAlgRhs DataFamilyTyCon{} DataFamilyTyCon{} = True
747 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
748 eqListBy eqCon (data_cons tc1) (data_cons tc2)
749 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
750 eqCon (data_con tc1) (data_con tc2)
754 = dataConName c1 == dataConName c2
755 && dataConIsInfix c1 == dataConIsInfix c2
756 && dataConStrictMarks c1 == dataConStrictMarks c2
757 && dataConFieldLabels c1 == dataConFieldLabels c2
758 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
759 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
760 env = rnBndrs2 env0 tvs1 tvs2
762 equalLength tvs1 tvs2 &&
763 eqListBy (tcEqPredX env)
764 (dataConEqTheta c1 ++ dataConDictTheta c1)
765 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
766 eqListBy (tcEqTypeX env)
767 (dataConOrigArgTys c1)
768 (dataConOrigArgTys c2)
771 missingBootThing :: Name -> String -> SDoc
772 missingBootThing name what
773 = ppr name <+> ptext (sLit "is exported by the hs-boot file, but not")
774 <+> text what <+> ptext (sLit "the module")
776 bootMisMatch :: TyThing -> IfaceDecl -> IfaceDecl -> SDoc
777 bootMisMatch thing boot_decl real_decl
778 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
779 ptext (sLit "Main module:") <+> ppr real_decl,
780 ptext (sLit "Boot file: ") <+> ppr boot_decl]
782 instMisMatch :: Instance -> SDoc
785 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
789 %************************************************************************
791 Type-checking the top level of a module
793 %************************************************************************
795 tcRnGroup takes a bunch of top-level source-code declarations, and
797 * gets supporting declarations from interface files
800 * and augments the TcGblEnv with the results
802 In Template Haskell it may be called repeatedly for each group of
803 declarations. It expects there to be an incoming TcGblEnv in the
804 monad; it augments it and returns the new TcGblEnv.
807 ------------------------------------------------
808 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
809 -- Fails if there are any errors
811 = do { -- Rename the source decls
812 traceTc "rn12" empty ;
813 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
814 traceTc "rn13" empty ;
816 -- save the renamed syntax, if we want it
818 | Just grp <- tcg_rn_decls tcg_env
819 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
823 -- Dump trace of renaming part
824 rnDump (ppr rn_decls) ;
826 return (tcg_env', rn_decls)
829 ------------------------------------------------
830 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
831 tcTopSrcDecls boot_details
832 (HsGroup { hs_tyclds = tycl_decls,
833 hs_instds = inst_decls,
834 hs_derivds = deriv_decls,
835 hs_fords = foreign_decls,
836 hs_defds = default_decls,
837 hs_annds = annotation_decls,
838 hs_ruleds = rule_decls,
839 hs_valds = val_binds })
840 = do { -- Type-check the type and class decls, and all imported decls
841 -- The latter come in via tycl_decls
842 traceTc "Tc2" empty ;
844 (tcg_env, aux_binds, dm_ids) <- tcTyAndClassDecls boot_details tycl_decls ;
845 -- If there are any errors, tcTyAndClassDecls fails here
848 tcExtendIdEnv dm_ids $ do {
850 -- Source-language instances, including derivings,
851 -- and import the supporting declarations
852 traceTc "Tc3" empty ;
853 (tcg_env, inst_infos, deriv_binds)
854 <- tcInstDecls1 (concat tycl_decls) inst_decls deriv_decls;
855 setGblEnv tcg_env $ do {
857 -- Foreign import declarations next.
858 traceTc "Tc4" empty ;
859 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
860 tcExtendGlobalValEnv fi_ids $ do {
862 -- Default declarations
863 traceTc "Tc4a" empty ;
864 default_tys <- tcDefaults default_decls ;
865 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
867 -- Now GHC-generated derived bindings, generics, and selectors
868 -- Do not generate warnings from compiler-generated code;
869 -- hence the use of discardWarnings
870 (tc_aux_binds, specs1, tcl_env) <- discardWarnings (tcTopBinds aux_binds) ;
871 (tc_deriv_binds, specs2, tcl_env) <- setLclTypeEnv tcl_env $
872 discardWarnings (tcTopBinds deriv_binds) ;
874 -- Value declarations next
875 traceTc "Tc5" empty ;
876 (tc_val_binds, specs3, tcl_env) <- setLclTypeEnv tcl_env $
877 tcTopBinds val_binds;
879 setLclTypeEnv tcl_env $ do { -- Environment doesn't change now
881 -- Second pass over class and instance declarations,
882 traceTc "Tc6" empty ;
883 inst_binds <- tcInstDecls2 (concat tycl_decls) inst_infos ;
886 traceTc "Tc7" empty ;
887 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
890 annotations <- tcAnnotations annotation_decls ;
893 rules <- tcRules rule_decls ;
896 traceTc "Tc7a" empty ;
897 tcg_env <- getGblEnv ;
898 let { all_binds = tc_val_binds `unionBags`
899 tc_deriv_binds `unionBags`
900 tc_aux_binds `unionBags`
901 inst_binds `unionBags`
904 ; sig_names = mkNameSet (collectHsValBinders val_binds)
905 `minusNameSet` getTypeSigNames val_binds
907 -- Extend the GblEnv with the (as yet un-zonked)
908 -- bindings, rules, foreign decls
909 ; tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds
910 , tcg_imp_specs = tcg_imp_specs tcg_env ++ specs1 ++ specs2 ++ specs3
911 , tcg_sigs = tcg_sigs tcg_env `unionNameSets` sig_names
912 , tcg_rules = tcg_rules tcg_env ++ rules
913 , tcg_anns = tcg_anns tcg_env ++ annotations
914 , tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
915 return (tcg_env', tcl_env)
920 %************************************************************************
924 %************************************************************************
927 checkMain :: TcM TcGblEnv
928 -- If we are in module Main, check that 'main' is defined.
930 = do { tcg_env <- getGblEnv ;
932 check_main dflags tcg_env
935 check_main :: DynFlags -> TcGblEnv -> TcM TcGblEnv
936 check_main dflags tcg_env
938 = traceTc "checkMain not" (ppr main_mod <+> ppr mod) >>
942 = do { mb_main <- lookupGlobalOccRn_maybe main_fn
943 -- Check that 'main' is in scope
944 -- It might be imported from another module!
946 Nothing -> do { traceTc "checkMain fail" (ppr main_mod <+> ppr main_fn)
951 { traceTc "checkMain found" (ppr main_mod <+> ppr main_fn)
952 ; let loc = srcLocSpan (getSrcLoc main_name)
953 ; ioTyCon <- tcLookupTyCon ioTyConName
954 ; res_ty <- newFlexiTyVarTy liftedTypeKind
956 <- addErrCtxt mainCtxt $
957 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
959 -- See Note [Root-main Id]
960 -- Construct the binding
961 -- :Main.main :: IO res_ty = runMainIO res_ty main
962 ; run_main_id <- tcLookupId runMainIOName
963 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
964 (mkVarOccFS (fsLit "main"))
965 (getSrcSpan main_name)
966 ; root_main_id = Id.mkExportedLocalId root_main_name
967 (mkTyConApp ioTyCon [res_ty])
968 ; co = mkWpTyApps [res_ty]
969 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
970 ; main_bind = mkVarBind root_main_id rhs }
972 ; return (tcg_env { tcg_main = Just main_name,
973 tcg_binds = tcg_binds tcg_env
975 tcg_dus = tcg_dus tcg_env
976 `plusDU` usesOnly (unitFV main_name)
977 -- Record the use of 'main', so that we don't
978 -- complain about it being defined but not used
982 mod = tcg_mod tcg_env
983 main_mod = mainModIs dflags
984 main_fn = getMainFun dflags
986 complain_no_main | ghcLink dflags == LinkInMemory = return ()
987 | otherwise = failWithTc noMainMsg
988 -- In interactive mode, don't worry about the absence of 'main'
989 -- In other modes, fail altogether, so that we don't go on
990 -- and complain a second time when processing the export list.
992 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
993 noMainMsg = ptext (sLit "The") <+> pp_main_fn
994 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
995 pp_main_fn = ppMainFn main_fn
997 ppMainFn :: RdrName -> SDoc
999 | main_fn == main_RDR_Unqual
1000 = ptext (sLit "function") <+> quotes (ppr main_fn)
1002 = ptext (sLit "main function") <+> quotes (ppr main_fn)
1004 -- | Get the unqualified name of the function to use as the \"main\" for the main module.
1005 -- Either returns the default name or the one configured on the command line with -main-is
1006 getMainFun :: DynFlags -> RdrName
1007 getMainFun dflags = case (mainFunIs dflags) of
1008 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
1009 Nothing -> main_RDR_Unqual
1011 checkMainExported :: TcGblEnv -> TcM ()
1012 checkMainExported tcg_env = do
1014 case tcg_main tcg_env of
1015 Nothing -> return () -- not the main module
1016 Just main_name -> do
1017 let main_mod = mainModIs dflags
1018 checkTc (main_name `elem` concatMap availNames (tcg_exports tcg_env)) $
1019 ptext (sLit "The") <+> ppMainFn (nameRdrName main_name) <+>
1020 ptext (sLit "is not exported by module") <+> quotes (ppr main_mod)
1025 The function that the RTS invokes is always :Main.main, which we call
1026 root_main_id. (Because GHC allows the user to have a module not
1027 called Main as the main module, we can't rely on the main function
1028 being called "Main.main". That's why root_main_id has a fixed module
1031 This is unusual: it's a LocalId whose Name has a Module from another
1032 module. Tiresomely, we must filter it out again in MkIface, les we
1033 get two defns for 'main' in the interface file!
1036 %*********************************************************
1040 %*********************************************************
1043 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
1044 setInteractiveContext hsc_env icxt thing_inside
1045 = let -- Initialise the tcg_inst_env with instances from all home modules.
1046 -- This mimics the more selective call to hptInstances in tcRnModule.
1047 (home_insts, home_fam_insts) = hptInstances hsc_env (\_ -> True)
1049 updGblEnv (\env -> env {
1050 tcg_rdr_env = ic_rn_gbl_env icxt,
1051 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
1052 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
1056 tcExtendGhciEnv (ic_tmp_ids icxt) $
1057 -- tcExtendGhciEnv does lots:
1058 -- - it extends the local type env (tcl_env) with the given Ids,
1059 -- - it extends the local rdr env (tcl_rdr) with the Names from
1061 -- - it adds the free tyvars of the Ids to the tcl_tyvars
1064 -- later ids in ic_tmp_ids must shadow earlier ones with the same
1065 -- OccName, and tcExtendIdEnv implements this behaviour.
1067 do { traceTc "setIC" (ppr (ic_tmp_ids icxt))
1075 -> InteractiveContext
1077 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1078 -- The returned [Id] is the list of new Ids bound by
1079 -- this statement. It can be used to extend the
1080 -- InteractiveContext via extendInteractiveContext.
1082 -- The returned TypecheckedHsExpr is of type IO [ () ],
1083 -- a list of the bound values, coerced to ().
1085 tcRnStmt hsc_env ictxt rdr_stmt
1086 = initTcPrintErrors hsc_env iNTERACTIVE $
1087 setInteractiveContext hsc_env ictxt $ do {
1089 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1090 (([rn_stmt], _), fvs) <- rnStmts GhciStmt [rdr_stmt] $ \_ ->
1091 return ((), emptyFVs) ;
1092 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1094 rnDump (ppr rn_stmt) ;
1096 -- The real work is done here
1097 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1098 zonked_expr <- zonkTopLExpr tc_expr ;
1099 zonked_ids <- zonkTopBndrs bound_ids ;
1101 -- None of the Ids should be of unboxed type, because we
1102 -- cast them all to HValues in the end!
1103 mapM_ bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1105 traceTc "tcs 1" empty ;
1106 let { global_ids = map globaliseAndTidyId zonked_ids } ;
1107 -- Note [Interactively-bound Ids in GHCi]
1109 {- ---------------------------------------------
1110 At one stage I removed any shadowed bindings from the type_env;
1111 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1112 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1114 Prelude> let f n = n * 2 :: Int
1115 Prelude> fName <- runQ [| f |]
1116 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1118 Prelude> let f n = n * 3 :: Int
1119 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1120 In the last line we use 'fName', which resolves to the *first* 'f'
1121 in scope. If we delete it from the type env, GHCi crashes because
1122 it doesn't expect that.
1124 Hence this code is commented out
1126 -------------------------------------------------- -}
1128 dumpOptTcRn Opt_D_dump_tc
1129 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1130 text "Typechecked expr" <+> ppr zonked_expr]) ;
1132 return (global_ids, zonked_expr)
1135 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1136 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1139 Note [Interactively-bound Ids in GHCi]
1140 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1141 The Ids bound by previous Stmts in Template Haskell are currently
1143 b) with an Internal Name (not External)
1144 c) and a tidied type
1146 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1147 compile an expression using these ids later, the byte code
1148 generator will consider the occurrences to be free rather than
1151 (b) They retain their Internal names becuase we don't have a suitable
1152 Module to name them with. We could revisit this choice.
1154 (c) Their types are tidied. This is important, because :info may ask
1155 to look at them, and :info expects the things it looks up to have
1159 --------------------------------------------------------------------------
1160 Typechecking Stmts in GHCi
1162 Here is the grand plan, implemented in tcUserStmt
1164 What you type The IO [HValue] that hscStmt returns
1165 ------------- ------------------------------------
1166 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1169 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1172 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1173 [NB: result not printed] bindings: [it]
1175 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1176 result showable) bindings: [it]
1178 expr (of non-IO type,
1179 result not showable) ==> error
1183 ---------------------------
1184 type PlanResult = ([Id], LHsExpr Id)
1185 type Plan = TcM PlanResult
1187 runPlans :: [Plan] -> TcM PlanResult
1188 -- Try the plans in order. If one fails (by raising an exn), try the next.
1189 -- If one succeeds, take it.
1190 runPlans [] = panic "runPlans"
1192 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1194 --------------------
1195 mkPlan :: LStmt Name -> TcM PlanResult
1196 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1197 = do { uniq <- newUnique -- is treated very specially
1198 ; let fresh_it = itName uniq
1199 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1200 matches = [mkMatch [] expr emptyLocalBinds]
1201 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1202 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1203 (HsVar bindIOName) noSyntaxExpr
1204 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1205 (HsVar thenIOName) placeHolderType
1208 -- [it <- e; print it] but not if it::()
1210 -- [let it = e; print it]
1211 ; runPlans [ -- Plan A
1212 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1213 ; it_ty <- zonkTcType (idType it_id)
1214 ; when (isUnitTy it_ty) failM
1217 -- Plan B; a naked bind statment
1218 tcGhciStmts [bind_stmt],
1220 -- Plan C; check that the let-binding is typeable all by itself.
1221 -- If not, fail; if so, try to print it.
1222 -- The two-step process avoids getting two errors: one from
1223 -- the expression itself, and one from the 'print it' part
1224 -- This two-step story is very clunky, alas
1225 do { _ <- checkNoErrs (tcGhciStmts [let_stmt])
1226 --- checkNoErrs defeats the error recovery of let-bindings
1227 ; tcGhciStmts [let_stmt, print_it] }
1230 mkPlan stmt@(L loc (BindStmt {}))
1231 | [v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1232 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1233 (HsVar thenIOName) placeHolderType
1235 ; print_bind_result <- doptM Opt_PrintBindResult
1236 ; let print_plan = do
1237 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1238 ; v_ty <- zonkTcType (idType v_id)
1239 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1243 -- [stmt; print v] but not if v::()
1245 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1246 [tcGhciStmts [stmt]])
1250 = tcGhciStmts [stmt]
1252 ---------------------------
1253 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1255 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1256 ret_id <- tcLookupId returnIOName ; -- return @ IO
1258 ret_ty = mkListTy unitTy ;
1259 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1260 tc_io_stmts stmts = tcStmts GhciStmt tcDoStmt stmts io_ret_ty ;
1262 names = collectLStmtsBinders stmts ;
1264 -- mk_return builds the expression
1265 -- returnIO @ [()] [coerce () x, .., coerce () z]
1267 -- Despite the inconvenience of building the type applications etc,
1268 -- this *has* to be done in type-annotated post-typecheck form
1269 -- because we are going to return a list of *polymorphic* values
1270 -- coerced to type (). If we built a *source* stmt
1271 -- return [coerce x, ..., coerce z]
1272 -- then the type checker would instantiate x..z, and we wouldn't
1273 -- get their *polymorphic* values. (And we'd get ambiguity errs
1274 -- if they were overloaded, since they aren't applied to anything.)
1275 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1276 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1277 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1281 -- OK, we're ready to typecheck the stmts
1282 traceTc "TcRnDriver.tcGhciStmts: tc stmts" empty ;
1283 ((tc_stmts, ids), lie) <- captureConstraints $ tc_io_stmts stmts $ \ _ ->
1284 mapM tcLookupId names ;
1285 -- Look up the names right in the middle,
1286 -- where they will all be in scope
1288 -- Simplify the context
1289 traceTc "TcRnDriver.tcGhciStmts: simplify ctxt" empty ;
1290 const_binds <- checkNoErrs (simplifyInteractive lie) ;
1291 -- checkNoErrs ensures that the plan fails if context redn fails
1293 traceTc "TcRnDriver.tcGhciStmts: done" empty ;
1294 return (ids, mkHsDictLet (EvBinds const_binds) $
1295 noLoc (HsDo GhciStmt tc_stmts (mk_return ids) io_ret_ty))
1300 tcRnExpr just finds the type of an expression
1304 -> InteractiveContext
1306 -> IO (Messages, Maybe Type)
1307 tcRnExpr hsc_env ictxt rdr_expr
1308 = initTcPrintErrors hsc_env iNTERACTIVE $
1309 setInteractiveContext hsc_env ictxt $ do {
1311 (rn_expr, _fvs) <- rnLExpr rdr_expr ;
1314 -- Now typecheck the expression;
1315 -- it might have a rank-2 type (e.g. :t runST)
1318 let { fresh_it = itName uniq } ;
1319 ((_tc_expr, res_ty), lie) <- captureConstraints (tcInferRho rn_expr) ;
1320 ((qtvs, dicts, _), lie_top) <- captureConstraints $
1321 simplifyInfer TopLevel
1322 False {- No MR for now -}
1323 [(fresh_it, res_ty)]
1326 _ <- simplifyInteractive lie_top ; -- Ignore the dicionary bindings
1328 let { all_expr_ty = mkForAllTys qtvs (mkPiTypes dicts res_ty) } ;
1329 zonkTcType all_expr_ty
1333 tcRnType just finds the kind of a type
1337 -> InteractiveContext
1339 -> IO (Messages, Maybe Kind)
1340 tcRnType hsc_env ictxt rdr_type
1341 = initTcPrintErrors hsc_env iNTERACTIVE $
1342 setInteractiveContext hsc_env ictxt $ do {
1344 rn_type <- rnLHsType doc rdr_type ;
1347 -- Now kind-check the type
1348 (_ty', kind) <- kcLHsType rn_type ;
1352 doc = ptext (sLit "In GHCi input")
1358 %************************************************************************
1360 More GHCi stuff, to do with browsing and getting info
1362 %************************************************************************
1366 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1367 -- a package module with an interface on disk. If neither of these is
1368 -- true, then the result will be an error indicating the interface
1369 -- could not be found.
1370 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1371 getModuleExports hsc_env mod
1374 checkMods = ic_toplev_scope ic ++ map fst (ic_exports ic)
1376 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1378 -- Get the export avail info and also load all orphan and family-instance
1379 -- modules. Finally, check that the family instances of all modules in the
1380 -- interactive context are consistent (these modules are in the second
1382 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1383 tcGetModuleExports mod directlyImpMods
1384 = do { let doc = ptext (sLit "context for compiling statements")
1385 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1387 -- Load any orphan-module and family instance-module
1388 -- interfaces, so their instances are visible.
1389 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1390 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1392 -- Check that the family instances of all directly loaded
1393 -- modules are consistent.
1394 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1396 ; ifaceExportNames (mi_exports iface)
1399 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1400 tcRnLookupRdrName hsc_env rdr_name
1401 = initTcPrintErrors hsc_env iNTERACTIVE $
1402 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1403 lookup_rdr_name rdr_name
1405 lookup_rdr_name :: RdrName -> TcM [Name]
1406 lookup_rdr_name rdr_name = do {
1407 -- If the identifier is a constructor (begins with an
1408 -- upper-case letter), then we need to consider both
1409 -- constructor and type class identifiers.
1410 let { rdr_names = dataTcOccs rdr_name } ;
1412 -- results :: [Either Messages Name]
1413 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1415 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1416 -- The successful lookups will be (Just name)
1417 let { (warns_s, good_names) = unzip [ (msgs, name)
1418 | (msgs, Just name) <- results] ;
1419 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1421 -- Fail if nothing good happened, else add warnings
1422 if null good_names then
1423 -- No lookup succeeded, so
1424 -- pick the first error message and report it
1425 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1426 -- while the other is "X is not in scope",
1427 -- we definitely want the former; but we might pick the latter
1428 do { addMessages (head errs_s) ; failM }
1429 else -- Add deprecation warnings
1430 mapM_ addMessages warns_s ;
1436 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1437 tcRnLookupName hsc_env name
1438 = initTcPrintErrors hsc_env iNTERACTIVE $
1439 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1440 tcRnLookupName' name
1442 -- To look up a name we have to look in the local environment (tcl_lcl)
1443 -- as well as the global environment, which is what tcLookup does.
1444 -- But we also want a TyThing, so we have to convert:
1446 tcRnLookupName' :: Name -> TcRn TyThing
1447 tcRnLookupName' name = do
1448 tcthing <- tcLookup name
1450 AGlobal thing -> return thing
1451 ATcId{tct_id=id} -> return (AnId id)
1452 _ -> panic "tcRnLookupName'"
1454 tcRnGetInfo :: HscEnv
1456 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1458 -- Used to implement :info in GHCi
1460 -- Look up a RdrName and return all the TyThings it might be
1461 -- A capitalised RdrName is given to us in the DataName namespace,
1462 -- but we want to treat it as *both* a data constructor
1463 -- *and* as a type or class constructor;
1464 -- hence the call to dataTcOccs, and we return up to two results
1465 tcRnGetInfo hsc_env name
1466 = initTcPrintErrors hsc_env iNTERACTIVE $
1467 tcRnGetInfo' hsc_env name
1469 tcRnGetInfo' :: HscEnv
1471 -> TcRn (TyThing, Fixity, [Instance])
1472 tcRnGetInfo' hsc_env name
1473 = let ictxt = hsc_IC hsc_env in
1474 setInteractiveContext hsc_env ictxt $ do
1476 -- Load the interface for all unqualified types and classes
1477 -- That way we will find all the instance declarations
1478 -- (Packages have not orphan modules, and we assume that
1479 -- in the home package all relevant modules are loaded.)
1480 loadUnqualIfaces ictxt
1482 thing <- tcRnLookupName' name
1483 fixity <- lookupFixityRn name
1484 ispecs <- lookupInsts thing
1485 return (thing, fixity, ispecs)
1487 lookupInsts :: TyThing -> TcM [Instance]
1488 lookupInsts (AClass cls)
1489 = do { inst_envs <- tcGetInstEnvs
1490 ; return (classInstances inst_envs cls) }
1492 lookupInsts (ATyCon tc)
1493 = do { (pkg_ie, home_ie) <- tcGetInstEnvs
1494 -- Load all instances for all classes that are
1495 -- in the type environment (which are all the ones
1496 -- we've seen in any interface file so far)
1497 ; return [ ispec -- Search all
1498 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1499 , let dfun = instanceDFunId ispec
1502 relevant df = tc_name `elemNameSet` orphNamesOfDFunHead (idType df)
1503 tc_name = tyConName tc
1505 lookupInsts _ = return []
1507 loadUnqualIfaces :: InteractiveContext -> TcM ()
1508 -- Load the home module for everything that is in scope unqualified
1509 -- This is so that we can accurately report the instances for
1511 loadUnqualIfaces ictxt
1513 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1515 unqual_mods = [ nameModule name
1516 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1517 let name = gre_name gre,
1518 not (isInternalName name),
1519 isTcOcc (nameOccName name), -- Types and classes only
1520 unQualOK gre ] -- In scope unqualified
1521 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1524 %************************************************************************
1528 %************************************************************************
1531 rnDump :: SDoc -> TcRn ()
1532 -- Dump, with a banner, if -ddump-rn
1533 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1535 tcDump :: TcGblEnv -> TcRn ()
1537 = do { dflags <- getDOpts ;
1539 -- Dump short output if -ddump-types or -ddump-tc
1540 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1541 (dumpTcRn short_dump) ;
1543 -- Dump bindings if -ddump-tc
1544 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1547 short_dump = pprTcGblEnv env
1548 full_dump = pprLHsBinds (tcg_binds env)
1549 -- NB: foreign x-d's have undefined's in their types;
1550 -- hence can't show the tc_fords
1552 tcCoreDump :: ModGuts -> TcM ()
1554 = do { dflags <- getDOpts ;
1555 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1556 (dumpTcRn (pprModGuts mod_guts)) ;
1558 -- Dump bindings if -ddump-tc
1559 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1561 full_dump = pprCoreBindings (mg_binds mod_guts)
1563 -- It's unpleasant having both pprModGuts and pprModDetails here
1564 pprTcGblEnv :: TcGblEnv -> SDoc
1565 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1567 tcg_fam_insts = fam_insts,
1569 tcg_imports = imports })
1570 = vcat [ ppr_types insts type_env
1571 , ppr_tycons fam_insts type_env
1573 , ppr_fam_insts fam_insts
1574 , vcat (map ppr rules)
1575 , ppr_gen_tycons (typeEnvTyCons type_env)
1576 , ptext (sLit "Dependent modules:") <+>
1577 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1578 , ptext (sLit "Dependent packages:") <+>
1579 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1580 where -- The two uses of sortBy are just to reduce unnecessary
1581 -- wobbling in testsuite output
1582 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1583 = (mod_name1 `stableModuleNameCmp` mod_name2)
1585 (is_boot1 `compare` is_boot2)
1587 pprModGuts :: ModGuts -> SDoc
1588 pprModGuts (ModGuts { mg_types = type_env,
1590 = vcat [ ppr_types [] type_env,
1593 ppr_types :: [Instance] -> TypeEnv -> SDoc
1594 ppr_types insts type_env
1595 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1597 dfun_ids = map instanceDFunId insts
1598 ids = [id | id <- typeEnvIds type_env, want_sig id]
1599 want_sig id | opt_PprStyle_Debug = True
1600 | otherwise = isLocalId id &&
1601 isExternalName (idName id) &&
1602 not (id `elem` dfun_ids)
1603 -- isLocalId ignores data constructors, records selectors etc.
1604 -- The isExternalName ignores local dictionary and method bindings
1605 -- that the type checker has invented. Top-level user-defined things
1606 -- have External names.
1608 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1609 ppr_tycons fam_insts type_env
1610 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1612 fi_tycons = map famInstTyCon fam_insts
1613 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1614 want_tycon tycon | opt_PprStyle_Debug = True
1615 | otherwise = not (isImplicitTyCon tycon) &&
1616 isExternalName (tyConName tycon) &&
1617 not (tycon `elem` fi_tycons)
1619 ppr_insts :: [Instance] -> SDoc
1620 ppr_insts [] = empty
1621 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1623 ppr_fam_insts :: [FamInst] -> SDoc
1624 ppr_fam_insts [] = empty
1625 ppr_fam_insts fam_insts =
1626 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1628 ppr_sigs :: [Var] -> SDoc
1630 -- Print type signatures; sort by OccName
1631 = vcat (map ppr_sig (sortLe le_sig ids))
1633 le_sig id1 id2 = getOccName id1 <= getOccName id2
1634 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1636 ppr_tydecls :: [TyCon] -> SDoc
1638 -- Print type constructor info; sort by OccName
1639 = vcat (map ppr_tycon (sortLe le_sig tycons))
1641 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1643 | isCoercionTyCon tycon
1644 = sep [ptext (sLit "coercion") <+> ppr tycon <+> ppr tvs
1645 , nest 2 (dcolon <+> pprEqPred (coercionKind (mkTyConApp tycon (mkTyVarTys tvs))))]
1646 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1648 tvs = take (tyConArity tycon) alphaTyVars
1650 ppr_rules :: [CoreRule] -> SDoc
1651 ppr_rules [] = empty
1652 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1653 nest 2 (pprRules rs),
1656 ppr_gen_tycons :: [TyCon] -> SDoc
1657 ppr_gen_tycons [] = empty
1658 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1659 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]