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 ;
369 -- Finish simplifying class constraints
371 -- simplifyTop deals with constant or ambiguous InstIds.
372 -- How could there be ambiguous ones? They can only arise if a
373 -- top-level decl falls under the monomorphism restriction
374 -- and no subsequent decl instantiates its type.
376 -- We do this after checkMain, so that we use the type info
377 -- thaat checkMain adds
379 -- We do it with both global and local env in scope:
380 -- * the global env exposes the instances to simplifyTop
381 -- * the local env exposes the local Ids to simplifyTop,
382 -- so that we get better error messages (monomorphism restriction)
383 traceTc "Tc8" empty ;
384 new_ev_binds <- setEnvs tc_envs (simplifyTop lie) ;
386 -- Backsubstitution. This must be done last.
387 -- Even simplifyTop may do some unification.
388 traceTc "Tc9" empty ;
389 let { (tcg_env, _) = tc_envs
390 ; TcGblEnv { tcg_type_env = type_env,
392 tcg_ev_binds = cur_ev_binds,
394 tcg_fords = fords } = tcg_env } ;
396 failIfErrsM ; -- Don't zonk if there have been errors
397 -- It's a waste of time; and we may get debug warnings
398 -- about strangely-typed TyCons!
400 let { all_ev_binds = cur_ev_binds `unionBags` new_ev_binds } ;
401 (bind_ids, ev_binds', binds', fords', rules')
402 <- zonkTopDecls all_ev_binds binds rules fords ;
405 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
406 ; tcg_env' = tcg_env { tcg_binds = binds',
407 tcg_ev_binds = ev_binds',
409 tcg_fords = fords' } } ;
411 setGlobalTypeEnv tcg_env' final_type_env
414 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
415 -- Loops around dealing with each top level inter-splice group
416 -- in turn, until it's dealt with the entire module
417 tc_rn_src_decls boot_details ds
418 = do { (first_group, group_tail) <- findSplice ds ;
419 -- If ds is [] we get ([], Nothing)
421 -- Deal with decls up to, but not including, the first splice
422 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
423 -- rnTopSrcDecls fails if there are any errors
425 (tcg_env, tcl_env) <- setGblEnv tcg_env $
426 tcTopSrcDecls boot_details rn_decls ;
428 -- If there is no splice, we're nearly done
429 setEnvs (tcg_env, tcl_env) $
431 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
432 return (tcg_env, tcl_env)
436 -- There shouldn't be a splice
437 Just (SpliceDecl {}, _) -> do {
438 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
440 -- If there's a splice, we must carry on
441 Just (SpliceDecl splice_expr _, rest_ds) -> do {
443 -- Rename the splice expression, and get its supporting decls
444 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
445 -- checkNoErrs: don't typecheck if renaming failed
446 rnDump (ppr rn_splice_expr) ;
448 -- Execute the splice
449 spliced_decls <- tcSpliceDecls rn_splice_expr ;
451 -- Glue them on the front of the remaining decls and loop
452 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
453 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
458 %************************************************************************
460 Compiling hs-boot source files, and
461 comparing the hi-boot interface with the real thing
463 %************************************************************************
466 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
467 tcRnHsBootDecls decls
468 = do { (first_group, group_tail) <- findSplice decls
470 -- Rename the declarations
471 ; (tcg_env, HsGroup {
472 hs_tyclds = tycl_decls,
473 hs_instds = inst_decls,
474 hs_derivds = deriv_decls,
475 hs_fords = for_decls,
476 hs_defds = def_decls,
477 hs_ruleds = rule_decls,
479 hs_valds = val_binds }) <- rnTopSrcDecls first_group
480 ; (gbl_env, lie) <- getConstraints $ setGblEnv tcg_env $ do {
483 -- Check for illegal declarations
485 Just (SpliceDecl d _, _) -> badBootDecl "splice" d
487 ; mapM_ (badBootDecl "foreign") for_decls
488 ; mapM_ (badBootDecl "default") def_decls
489 ; mapM_ (badBootDecl "rule") rule_decls
491 -- Typecheck type/class decls
492 ; traceTc "Tc2" empty
493 ; (tcg_env, aux_binds, dm_ids)
494 <- tcTyAndClassDecls emptyModDetails tycl_decls
495 ; setGblEnv tcg_env $
496 tcExtendIdEnv dm_ids $ do {
498 -- Typecheck instance decls
499 -- Family instance declarations are rejected here
500 ; traceTc "Tc3" empty
501 ; (tcg_env, inst_infos, _deriv_binds)
502 <- tcInstDecls1 tycl_decls inst_decls deriv_decls
503 ; setGblEnv tcg_env $ do {
505 -- Typecheck value declarations
506 ; traceTc "Tc5" empty
507 ; val_ids <- tcHsBootSigs val_binds
510 -- No simplification or zonking to do
511 ; traceTc "Tc7a" empty
512 ; gbl_env <- getGblEnv
514 -- Make the final type-env
515 -- Include the dfun_ids so that their type sigs
516 -- are written into the interface file.
517 -- And similarly the aux_ids from aux_binds
518 ; let { type_env0 = tcg_type_env gbl_env
519 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
520 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
521 ; type_env3 = extendTypeEnvWithIds type_env2 aux_ids
522 ; dfun_ids = map iDFunId inst_infos
523 ; aux_ids = case aux_binds of
524 ValBindsOut _ sigs -> [id | L _ (IdSig id) <- sigs]
525 _ -> panic "tcRnHsBoodDecls"
528 ; setGlobalTypeEnv gbl_env type_env3
530 ; traceTc "boot" (ppr lie); return gbl_env }
532 badBootDecl :: String -> Located decl -> TcM ()
533 badBootDecl what (L loc _)
534 = addErrAt loc (char 'A' <+> text what
535 <+> ptext (sLit "declaration is not (currently) allowed in a hs-boot file"))
538 Once we've typechecked the body of the module, we want to compare what
539 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
542 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
543 -- Compare the hi-boot file for this module (if there is one)
544 -- with the type environment we've just come up with
545 -- In the common case where there is no hi-boot file, the list
546 -- of boot_names is empty.
548 -- The bindings we return give bindings for the dfuns defined in the
549 -- hs-boot file, such as $fbEqT = $fEqT
552 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
553 tcg_insts = local_insts,
554 tcg_type_env = local_type_env, tcg_exports = local_exports })
555 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
556 md_types = boot_type_env, md_exports = boot_exports })
557 | isHsBoot hs_src -- Current module is already a hs-boot file!
561 = do { traceTc "checkHiBootIface" $ vcat
562 [ ppr boot_type_env, ppr boot_insts, ppr boot_exports]
564 -- Check the exports of the boot module, one by one
565 ; mapM_ check_export boot_exports
567 -- Check for no family instances
568 ; unless (null boot_fam_insts) $
569 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
570 "instances in boot files yet...")
571 -- FIXME: Why? The actual comparison is not hard, but what would
572 -- be the equivalent to the dfun bindings returned for class
573 -- instances? We can't easily equate tycons...
575 -- Check instance declarations
576 ; mb_dfun_prs <- mapM check_inst boot_insts
577 ; let dfun_prs = catMaybes mb_dfun_prs
578 boot_dfuns = map fst dfun_prs
579 dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun)
580 | (boot_dfun, dfun) <- dfun_prs ]
581 type_env' = extendTypeEnvWithIds local_type_env boot_dfuns
582 tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
585 ; setGlobalTypeEnv tcg_env' type_env' }
586 -- Update the global type env *including* the knot-tied one
587 -- so that if the source module reads in an interface unfolding
588 -- mentioning one of the dfuns from the boot module, then it
589 -- can "see" that boot dfun. See Trac #4003
591 check_export boot_avail -- boot_avail is exported by the boot iface
592 | name `elem` dfun_names = return ()
593 | isWiredInName name = return () -- No checking for wired-in names. In particular,
594 -- 'error' is handled by a rather gross hack
595 -- (see comments in GHC.Err.hs-boot)
597 -- Check that the actual module exports the same thing
598 | not (null missing_names)
599 = addErrAt (nameSrcSpan (head missing_names))
600 (missingBootThing (head missing_names) "exported by")
602 -- If the boot module does not *define* the thing, we are done
603 -- (it simply re-exports it, and names match, so nothing further to do)
604 | isNothing mb_boot_thing = return ()
606 -- Check that the actual module also defines the thing, and
607 -- then compare the definitions
608 | Just real_thing <- lookupTypeEnv local_type_env name,
609 Just boot_thing <- mb_boot_thing
610 = when (not (checkBootDecl boot_thing real_thing))
611 $ addErrAt (nameSrcSpan (getName boot_thing))
612 (let boot_decl = tyThingToIfaceDecl
613 (fromJust mb_boot_thing)
614 real_decl = tyThingToIfaceDecl real_thing
615 in bootMisMatch real_thing boot_decl real_decl)
618 = addErrTc (missingBootThing name "defined in")
620 name = availName boot_avail
621 mb_boot_thing = lookupTypeEnv boot_type_env name
622 missing_names = case lookupNameEnv local_export_env name of
624 Just avail -> availNames boot_avail `minusList` availNames avail
626 dfun_names = map getName boot_insts
628 local_export_env :: NameEnv AvailInfo
629 local_export_env = availsToNameEnv local_exports
631 check_inst :: Instance -> TcM (Maybe (Id, Id))
632 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
634 = case [dfun | inst <- local_insts,
635 let dfun = instanceDFunId inst,
636 idType dfun `tcEqType` boot_inst_ty ] of
637 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
638 (dfun:_) -> return (Just (local_boot_dfun, dfun))
640 boot_dfun = instanceDFunId boot_inst
641 boot_inst_ty = idType boot_dfun
642 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
645 -- This has to compare the TyThing from the .hi-boot file to the TyThing
646 -- in the current source file. We must be careful to allow alpha-renaming
647 -- where appropriate, and also the boot declaration is allowed to omit
648 -- constructors and class methods.
650 -- See rnfail055 for a good test of this stuff.
652 checkBootDecl :: TyThing -> TyThing -> Bool
654 checkBootDecl (AnId id1) (AnId id2)
656 (idType id1 `tcEqType` idType id2)
658 checkBootDecl (ATyCon tc1) (ATyCon tc2)
659 = checkBootTyCon tc1 tc2
661 checkBootDecl (AClass c1) (AClass c2)
663 (clas_tyvars1, clas_fds1, sc_theta1, _, ats1, op_stuff1)
664 = classExtraBigSig c1
665 (clas_tyvars2, clas_fds2, sc_theta2, _, ats2, op_stuff2)
666 = classExtraBigSig c2
668 env0 = mkRnEnv2 emptyInScopeSet
669 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
671 eqSig (id1, def_meth1) (id2, def_meth2)
672 = idName id1 == idName id2 &&
673 tcEqTypeX env op_ty1 op_ty2 &&
674 def_meth1 == def_meth2
676 (_, rho_ty1) = splitForAllTys (idType id1)
677 op_ty1 = funResultTy rho_ty1
678 (_, rho_ty2) = splitForAllTys (idType id2)
679 op_ty2 = funResultTy rho_ty2
681 eqFD (as1,bs1) (as2,bs2) =
682 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
683 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
685 same_kind tv1 tv2 = eqKind (tyVarKind tv1) (tyVarKind tv2)
687 eqListBy same_kind clas_tyvars1 clas_tyvars2 &&
688 -- Checks kind of class
689 eqListBy eqFD clas_fds1 clas_fds2 &&
690 (null sc_theta1 && null op_stuff1 && null ats1
691 || -- Above tests for an "abstract" class
692 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
693 eqListBy eqSig op_stuff1 op_stuff2 &&
694 eqListBy checkBootTyCon ats1 ats2)
696 checkBootDecl (ADataCon dc1) (ADataCon _)
697 = pprPanic "checkBootDecl" (ppr dc1)
699 checkBootDecl _ _ = False -- probably shouldn't happen
702 checkBootTyCon :: TyCon -> TyCon -> Bool
703 checkBootTyCon tc1 tc2
704 | not (eqKind (tyConKind tc1) (tyConKind tc2))
705 = False -- First off, check the kind
707 | isSynTyCon tc1 && isSynTyCon tc2
709 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
710 env = rnBndrs2 env0 tvs1 tvs2
712 eqSynRhs SynFamilyTyCon SynFamilyTyCon
714 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
715 = tcEqTypeX env t1 t2
718 equalLength tvs1 tvs2 &&
719 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
721 | isAlgTyCon tc1 && isAlgTyCon tc2
723 eqKind (tyConKind tc1) (tyConKind tc2) &&
724 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2) &&
725 eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
727 | isForeignTyCon tc1 && isForeignTyCon tc2
728 = eqKind (tyConKind tc1) (tyConKind tc2) &&
729 tyConExtName tc1 == tyConExtName tc2
733 env0 = mkRnEnv2 emptyInScopeSet
735 eqAlgRhs AbstractTyCon _ = True
736 eqAlgRhs DataFamilyTyCon{} DataFamilyTyCon{} = True
737 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
738 eqListBy eqCon (data_cons tc1) (data_cons tc2)
739 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
740 eqCon (data_con tc1) (data_con tc2)
744 = dataConName c1 == dataConName c2
745 && dataConIsInfix c1 == dataConIsInfix c2
746 && dataConStrictMarks c1 == dataConStrictMarks c2
747 && dataConFieldLabels c1 == dataConFieldLabels c2
748 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
749 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
750 env = rnBndrs2 env0 tvs1 tvs2
752 equalLength tvs1 tvs2 &&
753 eqListBy (tcEqPredX env)
754 (dataConEqTheta c1 ++ dataConDictTheta c1)
755 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
756 eqListBy (tcEqTypeX env)
757 (dataConOrigArgTys c1)
758 (dataConOrigArgTys c2)
761 missingBootThing :: Name -> String -> SDoc
762 missingBootThing name what
763 = ppr name <+> ptext (sLit "is exported by the hs-boot file, but not")
764 <+> text what <+> ptext (sLit "the module")
766 bootMisMatch :: TyThing -> IfaceDecl -> IfaceDecl -> SDoc
767 bootMisMatch thing boot_decl real_decl
768 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
769 ptext (sLit "Main module:") <+> ppr real_decl,
770 ptext (sLit "Boot file: ") <+> ppr boot_decl]
772 instMisMatch :: Instance -> SDoc
775 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
779 %************************************************************************
781 Type-checking the top level of a module
783 %************************************************************************
785 tcRnGroup takes a bunch of top-level source-code declarations, and
787 * gets supporting declarations from interface files
790 * and augments the TcGblEnv with the results
792 In Template Haskell it may be called repeatedly for each group of
793 declarations. It expects there to be an incoming TcGblEnv in the
794 monad; it augments it and returns the new TcGblEnv.
797 ------------------------------------------------
798 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
799 -- Fails if there are any errors
801 = do { -- Rename the source decls
802 traceTc "rn12" empty ;
803 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
804 traceTc "rn13" empty ;
806 -- save the renamed syntax, if we want it
808 | Just grp <- tcg_rn_decls tcg_env
809 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
813 -- Dump trace of renaming part
814 rnDump (ppr rn_decls) ;
816 return (tcg_env', rn_decls)
819 ------------------------------------------------
820 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
821 tcTopSrcDecls boot_details
822 (HsGroup { hs_tyclds = tycl_decls,
823 hs_instds = inst_decls,
824 hs_derivds = deriv_decls,
825 hs_fords = foreign_decls,
826 hs_defds = default_decls,
827 hs_annds = annotation_decls,
828 hs_ruleds = rule_decls,
829 hs_valds = val_binds })
830 = do { -- Type-check the type and class decls, and all imported decls
831 -- The latter come in via tycl_decls
832 traceTc "Tc2" empty ;
834 (tcg_env, aux_binds, dm_ids) <- tcTyAndClassDecls boot_details tycl_decls ;
835 -- If there are any errors, tcTyAndClassDecls fails here
838 tcExtendIdEnv dm_ids $ do {
840 -- Source-language instances, including derivings,
841 -- and import the supporting declarations
842 traceTc "Tc3" empty ;
843 (tcg_env, inst_infos, deriv_binds)
844 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
845 setGblEnv tcg_env $ do {
847 -- Foreign import declarations next.
848 traceTc "Tc4" empty ;
849 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
850 tcExtendGlobalValEnv fi_ids $ do {
852 -- Default declarations
853 traceTc "Tc4a" empty ;
854 default_tys <- tcDefaults default_decls ;
855 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
857 -- Now GHC-generated derived bindings, generics, and selectors
858 -- Do not generate warnings from compiler-generated code;
859 -- hence the use of discardWarnings
860 (tc_aux_binds, tcl_env) <- discardWarnings (tcTopBinds aux_binds) ;
861 (tc_deriv_binds, tcl_env) <- setLclTypeEnv tcl_env $
862 discardWarnings (tcTopBinds deriv_binds) ;
864 -- Value declarations next
865 traceTc "Tc5" empty ;
866 (tc_val_binds, tcl_env) <- setLclTypeEnv tcl_env $
867 tcTopBinds val_binds;
869 setLclTypeEnv tcl_env $ do { -- Environment doesn't change now
871 -- Second pass over class and instance declarations,
872 traceTc "Tc6" empty ;
873 inst_binds <- tcInstDecls2 tycl_decls inst_infos ;
876 traceTc "Tc7" empty ;
877 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
880 annotations <- tcAnnotations annotation_decls ;
883 rules <- tcRules rule_decls ;
886 traceTc "Tc7a" empty ;
887 tcg_env <- getGblEnv ;
888 let { all_binds = tc_val_binds `unionBags`
889 tc_deriv_binds `unionBags`
890 tc_aux_binds `unionBags`
891 inst_binds `unionBags`
894 -- Extend the GblEnv with the (as yet un-zonked)
895 -- bindings, rules, foreign decls
896 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
897 tcg_rules = tcg_rules tcg_env ++ rules,
898 tcg_anns = tcg_anns tcg_env ++ annotations,
899 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
900 return (tcg_env', tcl_env)
905 %************************************************************************
909 %************************************************************************
912 checkMain :: TcM TcGblEnv
913 -- If we are in module Main, check that 'main' is defined.
915 = do { tcg_env <- getGblEnv ;
917 check_main dflags tcg_env
920 check_main :: DynFlags -> TcGblEnv -> TcM TcGblEnv
921 check_main dflags tcg_env
923 = traceTc "checkMain not" (ppr main_mod <+> ppr mod) >>
927 = do { mb_main <- lookupGlobalOccRn_maybe main_fn
928 -- Check that 'main' is in scope
929 -- It might be imported from another module!
931 Nothing -> do { traceTc "checkMain fail" (ppr main_mod <+> ppr main_fn)
936 { traceTc "checkMain found" (ppr main_mod <+> ppr main_fn)
937 ; let loc = srcLocSpan (getSrcLoc main_name)
938 ; ioTyCon <- tcLookupTyCon ioTyConName
939 ; res_ty <- newFlexiTyVarTy liftedTypeKind
941 <- addErrCtxt mainCtxt $
942 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
944 -- See Note [Root-main Id]
945 -- Construct the binding
946 -- :Main.main :: IO res_ty = runMainIO res_ty main
947 ; run_main_id <- tcLookupId runMainIOName
948 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
949 (mkVarOccFS (fsLit "main"))
950 (getSrcSpan main_name)
951 ; root_main_id = Id.mkExportedLocalId root_main_name
952 (mkTyConApp ioTyCon [res_ty])
953 ; co = mkWpTyApps [res_ty]
954 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
955 ; main_bind = mkVarBind root_main_id rhs }
957 ; return (tcg_env { tcg_main = Just main_name,
958 tcg_binds = tcg_binds tcg_env
960 tcg_dus = tcg_dus tcg_env
961 `plusDU` usesOnly (unitFV main_name)
962 -- Record the use of 'main', so that we don't
963 -- complain about it being defined but not used
967 mod = tcg_mod tcg_env
968 main_mod = mainModIs dflags
969 main_fn = getMainFun dflags
971 complain_no_main | ghcLink dflags == LinkInMemory = return ()
972 | otherwise = failWithTc noMainMsg
973 -- In interactive mode, don't worry about the absence of 'main'
974 -- In other modes, fail altogether, so that we don't go on
975 -- and complain a second time when processing the export list.
977 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
978 noMainMsg = ptext (sLit "The") <+> pp_main_fn
979 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
980 pp_main_fn = ppMainFn main_fn
982 ppMainFn :: RdrName -> SDoc
984 | main_fn == main_RDR_Unqual
985 = ptext (sLit "function") <+> quotes (ppr main_fn)
987 = ptext (sLit "main function") <+> quotes (ppr main_fn)
989 -- | Get the unqualified name of the function to use as the \"main\" for the main module.
990 -- Either returns the default name or the one configured on the command line with -main-is
991 getMainFun :: DynFlags -> RdrName
992 getMainFun dflags = case (mainFunIs dflags) of
993 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
994 Nothing -> main_RDR_Unqual
996 checkMainExported :: TcGblEnv -> TcM ()
997 checkMainExported tcg_env = do
999 case tcg_main tcg_env of
1000 Nothing -> return () -- not the main module
1001 Just main_name -> do
1002 let main_mod = mainModIs dflags
1003 checkTc (main_name `elem` concatMap availNames (tcg_exports tcg_env)) $
1004 ptext (sLit "The") <+> ppMainFn (nameRdrName main_name) <+>
1005 ptext (sLit "is not exported by module") <+> quotes (ppr main_mod)
1010 The function that the RTS invokes is always :Main.main, which we call
1011 root_main_id. (Because GHC allows the user to have a module not
1012 called Main as the main module, we can't rely on the main function
1013 being called "Main.main". That's why root_main_id has a fixed module
1016 This is unusual: it's a LocalId whose Name has a Module from another
1017 module. Tiresomely, we must filter it out again in MkIface, les we
1018 get two defns for 'main' in the interface file!
1021 %*********************************************************
1025 %*********************************************************
1028 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
1029 setInteractiveContext hsc_env icxt thing_inside
1030 = let -- Initialise the tcg_inst_env with instances from all home modules.
1031 -- This mimics the more selective call to hptInstances in tcRnModule.
1032 (home_insts, home_fam_insts) = hptInstances hsc_env (\_ -> True)
1034 updGblEnv (\env -> env {
1035 tcg_rdr_env = ic_rn_gbl_env icxt,
1036 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
1037 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
1041 tcExtendGhciEnv (ic_tmp_ids icxt) $
1042 -- tcExtendGhciEnv does lots:
1043 -- - it extends the local type env (tcl_env) with the given Ids,
1044 -- - it extends the local rdr env (tcl_rdr) with the Names from
1046 -- - it adds the free tyvars of the Ids to the tcl_tyvars
1049 -- later ids in ic_tmp_ids must shadow earlier ones with the same
1050 -- OccName, and tcExtendIdEnv implements this behaviour.
1052 do { traceTc "setIC" (ppr (ic_tmp_ids icxt))
1060 -> InteractiveContext
1062 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1063 -- The returned [Id] is the list of new Ids bound by
1064 -- this statement. It can be used to extend the
1065 -- InteractiveContext via extendInteractiveContext.
1067 -- The returned TypecheckedHsExpr is of type IO [ () ],
1068 -- a list of the bound values, coerced to ().
1070 tcRnStmt hsc_env ictxt rdr_stmt
1071 = initTcPrintErrors hsc_env iNTERACTIVE $
1072 setInteractiveContext hsc_env ictxt $ do {
1074 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1075 (([rn_stmt], _), fvs) <- rnStmts GhciStmt [rdr_stmt] (return ((), emptyFVs)) ;
1076 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1078 rnDump (ppr rn_stmt) ;
1080 -- The real work is done here
1081 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1082 zonked_expr <- zonkTopLExpr tc_expr ;
1083 zonked_ids <- zonkTopBndrs bound_ids ;
1085 -- None of the Ids should be of unboxed type, because we
1086 -- cast them all to HValues in the end!
1087 mapM_ bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1089 traceTc "tcs 1" empty ;
1090 let { global_ids = map globaliseAndTidyId zonked_ids } ;
1091 -- Note [Interactively-bound Ids in GHCi]
1093 {- ---------------------------------------------
1094 At one stage I removed any shadowed bindings from the type_env;
1095 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1096 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1098 Prelude> let f n = n * 2 :: Int
1099 Prelude> fName <- runQ [| f |]
1100 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1102 Prelude> let f n = n * 3 :: Int
1103 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1104 In the last line we use 'fName', which resolves to the *first* 'f'
1105 in scope. If we delete it from the type env, GHCi crashes because
1106 it doesn't expect that.
1108 Hence this code is commented out
1110 -------------------------------------------------- -}
1112 dumpOptTcRn Opt_D_dump_tc
1113 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1114 text "Typechecked expr" <+> ppr zonked_expr]) ;
1116 return (global_ids, zonked_expr)
1119 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1120 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1123 Note [Interactively-bound Ids in GHCi]
1124 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1125 The Ids bound by previous Stmts in Template Haskell are currently
1127 b) with an Internal Name (not External)
1128 c) and a tidied type
1130 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1131 compile an expression using these ids later, the byte code
1132 generator will consider the occurrences to be free rather than
1135 (b) They retain their Internal names becuase we don't have a suitable
1136 Module to name them with. We could revisit this choice.
1138 (c) Their types are tidied. This is important, because :info may ask
1139 to look at them, and :info expects the things it looks up to have
1143 --------------------------------------------------------------------------
1144 Typechecking Stmts in GHCi
1146 Here is the grand plan, implemented in tcUserStmt
1148 What you type The IO [HValue] that hscStmt returns
1149 ------------- ------------------------------------
1150 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1153 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1156 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1157 [NB: result not printed] bindings: [it]
1159 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1160 result showable) bindings: [it]
1162 expr (of non-IO type,
1163 result not showable) ==> error
1167 ---------------------------
1168 type PlanResult = ([Id], LHsExpr Id)
1169 type Plan = TcM PlanResult
1171 runPlans :: [Plan] -> TcM PlanResult
1172 -- Try the plans in order. If one fails (by raising an exn), try the next.
1173 -- If one succeeds, take it.
1174 runPlans [] = panic "runPlans"
1176 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1178 --------------------
1179 mkPlan :: LStmt Name -> TcM PlanResult
1180 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1181 = do { uniq <- newUnique -- is treated very specially
1182 ; let fresh_it = itName uniq
1183 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1184 matches = [mkMatch [] expr emptyLocalBinds]
1185 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1186 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1187 (HsVar bindIOName) noSyntaxExpr
1188 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1189 (HsVar thenIOName) placeHolderType
1192 -- [it <- e; print it] but not if it::()
1194 -- [let it = e; print it]
1195 ; runPlans [ -- Plan A
1196 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1197 ; it_ty <- zonkTcType (idType it_id)
1198 ; when (isUnitTy it_ty) failM
1201 -- Plan B; a naked bind statment
1202 tcGhciStmts [bind_stmt],
1204 -- Plan C; check that the let-binding is typeable all by itself.
1205 -- If not, fail; if so, try to print it.
1206 -- The two-step process avoids getting two errors: one from
1207 -- the expression itself, and one from the 'print it' part
1208 -- This two-step story is very clunky, alas
1209 do { _ <- checkNoErrs (tcGhciStmts [let_stmt])
1210 --- checkNoErrs defeats the error recovery of let-bindings
1211 ; tcGhciStmts [let_stmt, print_it] }
1214 mkPlan stmt@(L loc (BindStmt {}))
1215 | [v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1216 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1217 (HsVar thenIOName) placeHolderType
1219 ; print_bind_result <- doptM Opt_PrintBindResult
1220 ; let print_plan = do
1221 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1222 ; v_ty <- zonkTcType (idType v_id)
1223 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1227 -- [stmt; print v] but not if v::()
1229 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1230 [tcGhciStmts [stmt]])
1234 = tcGhciStmts [stmt]
1236 ---------------------------
1237 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1239 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1240 ret_id <- tcLookupId returnIOName ; -- return @ IO
1242 ret_ty = mkListTy unitTy ;
1243 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1244 tc_io_stmts stmts = tcStmts GhciStmt tcDoStmt stmts io_ret_ty ;
1246 names = collectLStmtsBinders stmts ;
1248 -- mk_return builds the expression
1249 -- returnIO @ [()] [coerce () x, .., coerce () z]
1251 -- Despite the inconvenience of building the type applications etc,
1252 -- this *has* to be done in type-annotated post-typecheck form
1253 -- because we are going to return a list of *polymorphic* values
1254 -- coerced to type (). If we built a *source* stmt
1255 -- return [coerce x, ..., coerce z]
1256 -- then the type checker would instantiate x..z, and we wouldn't
1257 -- get their *polymorphic* values. (And we'd get ambiguity errs
1258 -- if they were overloaded, since they aren't applied to anything.)
1259 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1260 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1261 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1265 -- OK, we're ready to typecheck the stmts
1266 traceTc "TcRnDriver.tcGhciStmts: tc stmts" empty ;
1267 ((tc_stmts, ids), lie) <- getConstraints $ tc_io_stmts stmts $ \ _ ->
1268 mapM tcLookupId names ;
1269 -- Look up the names right in the middle,
1270 -- where they will all be in scope
1272 -- Simplify the context
1273 traceTc "TcRnDriver.tcGhciStmts: simplify ctxt" empty ;
1274 const_binds <- checkNoErrs (simplifyInteractive lie) ;
1275 -- checkNoErrs ensures that the plan fails if context redn fails
1277 traceTc "TcRnDriver.tcGhciStmts: done" empty ;
1278 return (ids, mkHsDictLet (EvBinds const_binds) $
1279 noLoc (HsDo GhciStmt tc_stmts (mk_return ids) io_ret_ty))
1284 tcRnExpr just finds the type of an expression
1288 -> InteractiveContext
1290 -> IO (Messages, Maybe Type)
1291 tcRnExpr hsc_env ictxt rdr_expr
1292 = initTcPrintErrors hsc_env iNTERACTIVE $
1293 setInteractiveContext hsc_env ictxt $ do {
1295 (rn_expr, _fvs) <- rnLExpr rdr_expr ;
1298 -- Now typecheck the expression;
1299 -- it might have a rank-2 type (e.g. :t runST)
1300 ((_tc_expr, res_ty), lie) <- getConstraints (tcInferRho rn_expr) ;
1301 ((qtvs, dicts, _), lie_top) <- getConstraints (simplifyInfer False {- No MR for now -}
1302 (tyVarsOfType res_ty) lie) ;
1303 _ <- simplifyInteractive lie_top ; -- Ignore the dicionary bindings
1305 let { all_expr_ty = mkForAllTys qtvs (mkPiTypes dicts res_ty) } ;
1306 zonkTcType all_expr_ty
1310 tcRnType just finds the kind of a type
1314 -> InteractiveContext
1316 -> IO (Messages, Maybe Kind)
1317 tcRnType hsc_env ictxt rdr_type
1318 = initTcPrintErrors hsc_env iNTERACTIVE $
1319 setInteractiveContext hsc_env ictxt $ do {
1321 rn_type <- rnLHsType doc rdr_type ;
1324 -- Now kind-check the type
1325 (_ty', kind) <- kcLHsType rn_type ;
1329 doc = ptext (sLit "In GHCi input")
1335 %************************************************************************
1337 More GHCi stuff, to do with browsing and getting info
1339 %************************************************************************
1343 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1344 -- a package module with an interface on disk. If neither of these is
1345 -- true, then the result will be an error indicating the interface
1346 -- could not be found.
1347 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1348 getModuleExports hsc_env mod
1351 checkMods = ic_toplev_scope ic ++ map fst (ic_exports ic)
1353 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1355 -- Get the export avail info and also load all orphan and family-instance
1356 -- modules. Finally, check that the family instances of all modules in the
1357 -- interactive context are consistent (these modules are in the second
1359 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1360 tcGetModuleExports mod directlyImpMods
1361 = do { let doc = ptext (sLit "context for compiling statements")
1362 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1364 -- Load any orphan-module and family instance-module
1365 -- interfaces, so their instances are visible.
1366 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1367 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1369 -- Check that the family instances of all directly loaded
1370 -- modules are consistent.
1371 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1373 ; ifaceExportNames (mi_exports iface)
1376 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1377 tcRnLookupRdrName hsc_env rdr_name
1378 = initTcPrintErrors hsc_env iNTERACTIVE $
1379 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1380 lookup_rdr_name rdr_name
1382 lookup_rdr_name :: RdrName -> TcM [Name]
1383 lookup_rdr_name rdr_name = do {
1384 -- If the identifier is a constructor (begins with an
1385 -- upper-case letter), then we need to consider both
1386 -- constructor and type class identifiers.
1387 let { rdr_names = dataTcOccs rdr_name } ;
1389 -- results :: [Either Messages Name]
1390 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1392 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1393 -- The successful lookups will be (Just name)
1394 let { (warns_s, good_names) = unzip [ (msgs, name)
1395 | (msgs, Just name) <- results] ;
1396 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1398 -- Fail if nothing good happened, else add warnings
1399 if null good_names then
1400 -- No lookup succeeded, so
1401 -- pick the first error message and report it
1402 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1403 -- while the other is "X is not in scope",
1404 -- we definitely want the former; but we might pick the latter
1405 do { addMessages (head errs_s) ; failM }
1406 else -- Add deprecation warnings
1407 mapM_ addMessages warns_s ;
1413 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1414 tcRnLookupName hsc_env name
1415 = initTcPrintErrors hsc_env iNTERACTIVE $
1416 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1417 tcRnLookupName' name
1419 -- To look up a name we have to look in the local environment (tcl_lcl)
1420 -- as well as the global environment, which is what tcLookup does.
1421 -- But we also want a TyThing, so we have to convert:
1423 tcRnLookupName' :: Name -> TcRn TyThing
1424 tcRnLookupName' name = do
1425 tcthing <- tcLookup name
1427 AGlobal thing -> return thing
1428 ATcId{tct_id=id} -> return (AnId id)
1429 _ -> panic "tcRnLookupName'"
1431 tcRnGetInfo :: HscEnv
1433 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1435 -- Used to implement :info in GHCi
1437 -- Look up a RdrName and return all the TyThings it might be
1438 -- A capitalised RdrName is given to us in the DataName namespace,
1439 -- but we want to treat it as *both* a data constructor
1440 -- *and* as a type or class constructor;
1441 -- hence the call to dataTcOccs, and we return up to two results
1442 tcRnGetInfo hsc_env name
1443 = initTcPrintErrors hsc_env iNTERACTIVE $
1444 tcRnGetInfo' hsc_env name
1446 tcRnGetInfo' :: HscEnv
1448 -> TcRn (TyThing, Fixity, [Instance])
1449 tcRnGetInfo' hsc_env name
1450 = let ictxt = hsc_IC hsc_env in
1451 setInteractiveContext hsc_env ictxt $ do
1453 -- Load the interface for all unqualified types and classes
1454 -- That way we will find all the instance declarations
1455 -- (Packages have not orphan modules, and we assume that
1456 -- in the home package all relevant modules are loaded.)
1457 loadUnqualIfaces ictxt
1459 thing <- tcRnLookupName' name
1460 fixity <- lookupFixityRn name
1461 ispecs <- lookupInsts thing
1462 return (thing, fixity, ispecs)
1464 lookupInsts :: TyThing -> TcM [Instance]
1465 lookupInsts (AClass cls)
1466 = do { inst_envs <- tcGetInstEnvs
1467 ; return (classInstances inst_envs cls) }
1469 lookupInsts (ATyCon tc)
1470 = do { (pkg_ie, home_ie) <- tcGetInstEnvs
1471 -- Load all instances for all classes that are
1472 -- in the type environment (which are all the ones
1473 -- we've seen in any interface file so far)
1474 ; return [ ispec -- Search all
1475 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1476 , let dfun = instanceDFunId ispec
1479 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1480 tc_name = tyConName tc
1482 lookupInsts _ = return []
1484 loadUnqualIfaces :: InteractiveContext -> TcM ()
1485 -- Load the home module for everything that is in scope unqualified
1486 -- This is so that we can accurately report the instances for
1488 loadUnqualIfaces ictxt
1490 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1492 unqual_mods = [ nameModule name
1493 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1494 let name = gre_name gre,
1495 not (isInternalName name),
1496 isTcOcc (nameOccName name), -- Types and classes only
1497 unQualOK gre ] -- In scope unqualified
1498 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1501 %************************************************************************
1505 %************************************************************************
1508 rnDump :: SDoc -> TcRn ()
1509 -- Dump, with a banner, if -ddump-rn
1510 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1512 tcDump :: TcGblEnv -> TcRn ()
1514 = do { dflags <- getDOpts ;
1516 -- Dump short output if -ddump-types or -ddump-tc
1517 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1518 (dumpTcRn short_dump) ;
1520 -- Dump bindings if -ddump-tc
1521 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1524 short_dump = pprTcGblEnv env
1525 full_dump = pprLHsBinds (tcg_binds env)
1526 -- NB: foreign x-d's have undefined's in their types;
1527 -- hence can't show the tc_fords
1529 tcCoreDump :: ModGuts -> TcM ()
1531 = do { dflags <- getDOpts ;
1532 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1533 (dumpTcRn (pprModGuts mod_guts)) ;
1535 -- Dump bindings if -ddump-tc
1536 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1538 full_dump = pprCoreBindings (mg_binds mod_guts)
1540 -- It's unpleasant having both pprModGuts and pprModDetails here
1541 pprTcGblEnv :: TcGblEnv -> SDoc
1542 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1544 tcg_fam_insts = fam_insts,
1546 tcg_imports = imports })
1547 = vcat [ ppr_types insts type_env
1548 , ppr_tycons fam_insts type_env
1550 , ppr_fam_insts fam_insts
1551 , vcat (map ppr rules)
1552 , ppr_gen_tycons (typeEnvTyCons type_env)
1553 , ptext (sLit "Dependent modules:") <+>
1554 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1555 , ptext (sLit "Dependent packages:") <+>
1556 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1557 where -- The two uses of sortBy are just to reduce unnecessary
1558 -- wobbling in testsuite output
1559 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1560 = (mod_name1 `stableModuleNameCmp` mod_name2)
1562 (is_boot1 `compare` is_boot2)
1564 pprModGuts :: ModGuts -> SDoc
1565 pprModGuts (ModGuts { mg_types = type_env,
1567 = vcat [ ppr_types [] type_env,
1570 ppr_types :: [Instance] -> TypeEnv -> SDoc
1571 ppr_types insts type_env
1572 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1574 dfun_ids = map instanceDFunId insts
1575 ids = [id | id <- typeEnvIds type_env, want_sig id]
1576 want_sig id | opt_PprStyle_Debug = True
1577 | otherwise = isLocalId id &&
1578 isExternalName (idName id) &&
1579 not (id `elem` dfun_ids)
1580 -- isLocalId ignores data constructors, records selectors etc.
1581 -- The isExternalName ignores local dictionary and method bindings
1582 -- that the type checker has invented. Top-level user-defined things
1583 -- have External names.
1585 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1586 ppr_tycons fam_insts type_env
1587 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1589 fi_tycons = map famInstTyCon fam_insts
1590 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1591 want_tycon tycon | opt_PprStyle_Debug = True
1592 | otherwise = not (isImplicitTyCon tycon) &&
1593 isExternalName (tyConName tycon) &&
1594 not (tycon `elem` fi_tycons)
1596 ppr_insts :: [Instance] -> SDoc
1597 ppr_insts [] = empty
1598 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1600 ppr_fam_insts :: [FamInst] -> SDoc
1601 ppr_fam_insts [] = empty
1602 ppr_fam_insts fam_insts =
1603 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1605 ppr_sigs :: [Var] -> SDoc
1607 -- Print type signatures; sort by OccName
1608 = vcat (map ppr_sig (sortLe le_sig ids))
1610 le_sig id1 id2 = getOccName id1 <= getOccName id2
1611 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1613 ppr_tydecls :: [TyCon] -> SDoc
1615 -- Print type constructor info; sort by OccName
1616 = vcat (map ppr_tycon (sortLe le_sig tycons))
1618 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1620 | isCoercionTyCon tycon
1621 = sep [ptext (sLit "coercion") <+> ppr tycon <+> ppr tvs
1622 , nest 2 (dcolon <+> pprEqPred (coercionKind (mkTyConApp tycon (mkTyVarTys tvs))))]
1623 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1625 tvs = take (tyConArity tycon) alphaTyVars
1627 ppr_rules :: [CoreRule] -> SDoc
1628 ppr_rules [] = empty
1629 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1630 nest 2 (pprRules rs),
1633 ppr_gen_tycons :: [TyCon] -> SDoc
1634 ppr_gen_tycons [] = empty
1635 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1636 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]