2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
5 \section[TcModule]{Typechecking a whole module}
9 -- The above warning supression flag is a temporary kludge.
10 -- While working on this module you are encouraged to remove it and fix
11 -- any warnings in the module. See
12 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
17 tcRnStmt, tcRnExpr, tcRnType,
30 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
59 import TcUnify ( withBox )
85 import Data.List ( sortBy )
97 import {- Kind parts of -} Type
99 import Foreign.Ptr( Ptr )
100 import TidyPgm ( globaliseAndTidyId )
109 import Data.Maybe ( isJust )
111 #include "HsVersions.h"
116 %************************************************************************
118 Typecheck and rename a module
120 %************************************************************************
126 -> Bool -- True <=> save renamed syntax
127 -> Located (HsModule RdrName)
128 -> IO (Messages, Maybe TcGblEnv)
130 tcRnModule hsc_env hsc_src save_rn_syntax
131 (L loc (HsModule maybe_mod export_ies
132 import_decls local_decls mod_deprec
133 module_info maybe_doc))
134 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
136 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
137 this_mod = case maybe_mod of
138 Nothing -> mAIN -- 'module M where' is omitted
139 Just (L _ mod) -> mkModule this_pkg mod } ;
142 initTc hsc_env hsc_src save_rn_syntax this_mod $
144 do { -- Deal with imports;
145 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
146 setGblEnv tcg_env $ do {
148 -- Load the hi-boot interface for this module, if any
149 -- We do this now so that the boot_names can be passed
150 -- to tcTyAndClassDecls, because the boot_names are
151 -- automatically considered to be loop breakers
153 -- Do this *after* tcRnImports, so that we know whether
154 -- a module that we import imports us; and hence whether to
155 -- look for a hi-boot file
156 boot_iface <- tcHiBootIface hsc_src this_mod ;
158 -- Rename and type check the declarations
159 traceRn (text "rn1a") ;
160 tcg_env <- if isHsBoot hsc_src then
161 tcRnHsBootDecls local_decls
163 tcRnSrcDecls boot_iface local_decls ;
164 setGblEnv tcg_env $ do {
166 -- Report the use of any deprecated things
167 -- We do this *before* processsing the export list so
168 -- that we don't bleat about re-exporting a deprecated
169 -- thing (especially via 'module Foo' export item)
170 -- That is, only uses in the *body* of the module are complained about
171 traceRn (text "rn3") ;
172 failIfErrsM ; -- finishWarnings crashes sometimes
173 -- as a result of typechecker repairs (e.g. unboundNames)
174 tcg_env <- finishWarnings (hsc_dflags hsc_env) mod_deprec tcg_env ;
176 -- Process the export list
177 traceRn (text "rn4a: before exports");
178 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
179 traceRn (text "rn4b: after exportss") ;
181 -- Compare the hi-boot iface (if any) with the real thing
182 -- Must be done after processing the exports
183 tcg_env <- checkHiBootIface tcg_env boot_iface ;
185 -- The new type env is already available to stuff slurped from
186 -- interface files, via TcEnv.updateGlobalTypeEnv
187 -- It's important that this includes the stuff in checkHiBootIface,
188 -- because the latter might add new bindings for boot_dfuns,
189 -- which may be mentioned in imported unfoldings
191 -- Rename the Haddock documentation
192 tcg_env <- rnHaddock module_info maybe_doc tcg_env ;
194 -- Report unused names
195 reportUnusedNames export_ies tcg_env ;
197 -- Dump output and return
204 %************************************************************************
208 %************************************************************************
211 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
212 tcRnImports hsc_env this_mod import_decls
213 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
215 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
216 ; dep_mods = imp_dep_mods imports
218 -- We want instance declarations from all home-package
219 -- modules below this one, including boot modules, except
220 -- ourselves. The 'except ourselves' is so that we don't
221 -- get the instances from this module's hs-boot file
222 ; want_instances :: ModuleName -> Bool
223 ; want_instances mod = mod `elemUFM` dep_mods
224 && mod /= moduleName this_mod
225 ; (home_insts, home_fam_insts) = hptInstances hsc_env
229 -- Record boot-file info in the EPS, so that it's
230 -- visible to loadHiBootInterface in tcRnSrcDecls,
231 -- and any other incrementally-performed imports
232 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
234 -- Update the gbl env
235 ; updGblEnv ( \ gbl ->
237 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
238 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
239 tcg_rn_imports = fmap (const rn_imports) (tcg_rn_imports gbl),
240 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
241 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
246 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
247 -- Fail if there are any errors so far
248 -- The error printing (if needed) takes advantage
249 -- of the tcg_env we have now set
250 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
253 -- Load any orphan-module and family instance-module
254 -- interfaces, so that their rules and instance decls will be
256 ; loadOrphanModules (imp_orphs imports) False
257 ; loadOrphanModules (imp_finsts imports) True
259 -- Check type-familily consistency
260 ; traceRn (text "rn1: checking family instance consistency")
261 ; let { dir_imp_mods = moduleEnvKeys
264 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
270 %************************************************************************
272 Type-checking external-core modules
274 %************************************************************************
277 tcRnExtCore :: HscEnv
279 -> IO (Messages, Maybe ModGuts)
280 -- Nothing => some error occurred
282 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
283 -- The decls are IfaceDecls; all names are original names
284 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
286 initTc hsc_env ExtCoreFile False this_mod $ do {
288 let { ldecls = map noLoc decls } ;
290 -- bring the type and class decls into scope
291 -- ToDo: check that this doesn't need to extract the val binds.
292 -- It seems that only the type and class decls need to be in scope below because
293 -- (a) tcTyAndClassDecls doesn't need the val binds, and
294 -- (b) tcExtCoreBindings doesn't need anything
295 -- (in fact, it might not even need to be in the scope of
296 -- this tcg_env at all)
297 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
298 tc_envs <- extendGlobalRdrEnvRn avails emptyFsEnv {- no fixity decls -} ;
300 setEnvs tc_envs $ do {
302 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
304 -- Dump trace of renaming part
305 rnDump (ppr rn_decls) ;
307 -- Typecheck them all together so that
308 -- any mutually recursive types are done right
309 -- Just discard the auxiliary bindings; they are generated
310 -- only for Haskell source code, and should already be in Core
311 (tcg_env, _aux_binds) <- tcTyAndClassDecls emptyModDetails rn_decls ;
313 setGblEnv tcg_env $ do {
314 -- Make the new type env available to stuff slurped from interface files
316 -- Now the core bindings
317 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
321 bndrs = bindersOfBinds core_binds ;
322 my_exports = map (Avail . idName) bndrs ;
323 -- ToDo: export the data types also?
326 extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
328 mod_guts = ModGuts { mg_module = this_mod,
330 mg_used_names = emptyNameSet, -- ToDo: compute usage
331 mg_dir_imps = emptyModuleEnv, -- ??
332 mg_deps = noDependencies, -- ??
333 mg_exports = my_exports,
334 mg_types = final_type_env,
335 mg_insts = tcg_insts tcg_env,
336 mg_fam_insts = tcg_fam_insts tcg_env,
337 mg_inst_env = tcg_inst_env tcg_env,
338 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
340 mg_binds = core_binds,
343 mg_rdr_env = emptyGlobalRdrEnv,
344 mg_fix_env = emptyFixityEnv,
345 mg_warns = NoWarnings,
346 mg_foreign = NoStubs,
347 mg_hpc_info = emptyHpcInfo False,
348 mg_modBreaks = emptyModBreaks,
349 mg_vect_info = noVectInfo
352 tcCoreDump mod_guts ;
357 mkFakeGroup decls -- Rather clumsy; lots of unused fields
358 = emptyRdrGroup { hs_tyclds = decls }
362 %************************************************************************
364 Type-checking the top level of a module
366 %************************************************************************
369 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
370 -- Returns the variables free in the decls
371 -- Reason: solely to report unused imports and bindings
372 tcRnSrcDecls boot_iface decls
373 = do { -- Do all the declarations
374 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
376 -- Finish simplifying class constraints
378 -- tcSimplifyTop deals with constant or ambiguous InstIds.
379 -- How could there be ambiguous ones? They can only arise if a
380 -- top-level decl falls under the monomorphism restriction
381 -- and no subsequent decl instantiates its type.
383 -- We do this after checkMain, so that we use the type info
384 -- thaat checkMain adds
386 -- We do it with both global and local env in scope:
387 -- * the global env exposes the instances to tcSimplifyTop
388 -- * the local env exposes the local Ids to tcSimplifyTop,
389 -- so that we get better error messages (monomorphism restriction)
390 traceTc (text "Tc8") ;
391 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
393 -- Backsubstitution. This must be done last.
394 -- Even tcSimplifyTop may do some unification.
395 traceTc (text "Tc9") ;
396 let { (tcg_env, _) = tc_envs
397 ; TcGblEnv { tcg_type_env = type_env,
400 tcg_fords = fords } = tcg_env
401 ; all_binds = binds `unionBags` inst_binds } ;
403 failIfErrsM ; -- Don't zonk if there have been errors
404 -- It's a waste of time; and we may get debug warnings
405 -- about strangely-typed TyCons!
407 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
410 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
411 ; tcg_env' = tcg_env { tcg_binds = binds',
413 tcg_fords = fords' } } ;
415 setGlobalTypeEnv tcg_env' final_type_env
418 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
419 -- Loops around dealing with each top level inter-splice group
420 -- in turn, until it's dealt with the entire module
421 tc_rn_src_decls boot_details ds
422 = do { let { (first_group, group_tail) = findSplice ds } ;
423 -- If ds is [] we get ([], Nothing)
425 -- Deal with decls up to, but not including, the first splice
426 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
427 -- rnTopSrcDecls fails if there are any errors
429 (tcg_env, tcl_env) <- setGblEnv tcg_env $
430 tcTopSrcDecls boot_details rn_decls ;
432 -- If there is no splice, we're nearly done
433 setEnvs (tcg_env, tcl_env) $
435 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
436 return (tcg_env, tcl_env)
439 -- If there's a splice, we must carry on
440 Just (SpliceDecl splice_expr, rest_ds) -> do {
442 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
445 -- Rename the splice expression, and get its supporting decls
446 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
447 -- checkNoErrs: don't typecheck if renaming failed
448 rnDump (ppr rn_splice_expr) ;
450 -- Execute the splice
451 spliced_decls <- tcSpliceDecls rn_splice_expr ;
453 -- Glue them on the front of the remaining decls and loop
454 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
455 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
460 %************************************************************************
462 Compiling hs-boot source files, and
463 comparing the hi-boot interface with the real thing
465 %************************************************************************
468 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
469 tcRnHsBootDecls decls
470 = do { let { (first_group, group_tail) = findSplice decls }
473 Just stuff -> spliceInHsBootErr stuff
476 -- Rename the declarations
477 ; (tcg_env, HsGroup {
478 hs_tyclds = tycl_decls,
479 hs_instds = inst_decls,
480 hs_derivds = deriv_decls,
482 hs_defds = _, -- Todo: check no foreign decls, no rules,
483 hs_ruleds = _, -- no default decls and no annotation decls
485 hs_valds = val_binds }) <- rnTopSrcDecls first_group
486 ; setGblEnv tcg_env $ do {
489 -- Typecheck type/class decls
490 ; traceTc (text "Tc2")
491 ; (tcg_env, aux_binds) <- tcTyAndClassDecls emptyModDetails tycl_decls
492 ; setGblEnv tcg_env $ do {
494 -- Typecheck instance decls
495 ; traceTc (text "Tc3")
496 ; (tcg_env, inst_infos, _deriv_binds)
497 <- tcInstDecls1 tycl_decls inst_decls deriv_decls
498 ; setGblEnv tcg_env $ do {
500 -- Typecheck value declarations
501 ; traceTc (text "Tc5")
502 ; val_ids <- tcHsBootSigs val_binds
505 -- No simplification or zonking to do
506 ; traceTc (text "Tc7a")
507 ; gbl_env <- getGblEnv
509 -- Make the final type-env
510 -- Include the dfun_ids so that their type sigs
511 -- are written into the interface file.
512 -- And similarly the aux_ids from aux_binds
513 ; let { type_env0 = tcg_type_env gbl_env
514 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
515 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
516 ; type_env3 = extendTypeEnvWithIds type_env1 aux_ids
517 ; dfun_ids = map iDFunId inst_infos
518 ; aux_ids = case aux_binds of
519 ValBindsOut _ sigs -> [id | L _ (IdSig id) <- sigs]
520 _ -> panic "tcRnHsBoodDecls"
523 ; setGlobalTypeEnv gbl_env type_env2
526 spliceInHsBootErr (SpliceDecl (L loc _), _)
527 = addErrAt loc (ptext (sLit "Splices are not allowed in hs-boot files"))
530 Once we've typechecked the body of the module, we want to compare what
531 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
534 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
535 -- Compare the hi-boot file for this module (if there is one)
536 -- with the type environment we've just come up with
537 -- In the common case where there is no hi-boot file, the list
538 -- of boot_names is empty.
540 -- The bindings we return give bindings for the dfuns defined in the
541 -- hs-boot file, such as $fbEqT = $fEqT
544 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
545 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
546 tcg_type_env = local_type_env, tcg_exports = local_exports })
547 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
548 md_types = boot_type_env, md_exports = boot_exports })
549 | isHsBoot hs_src -- Current module is already a hs-boot file!
553 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
556 -- Check the exports of the boot module, one by one
557 ; mapM_ check_export boot_exports
559 -- Check for no family instances
560 ; unless (null boot_fam_insts) $
561 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
562 "instances in boot files yet...")
563 -- FIXME: Why? The actual comparison is not hard, but what would
564 -- be the equivalent to the dfun bindings returned for class
565 -- instances? We can't easily equate tycons...
567 -- Check instance declarations
568 ; mb_dfun_prs <- mapM check_inst boot_insts
569 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
570 final_type_env = extendTypeEnvWithIds local_type_env boot_dfuns
571 dfun_prs = catMaybes mb_dfun_prs
572 boot_dfuns = map fst dfun_prs
573 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
574 | (boot_dfun, dfun) <- dfun_prs ]
577 ; setGlobalTypeEnv tcg_env' final_type_env }
579 check_export boot_avail -- boot_avail is exported by the boot iface
580 | name `elem` dfun_names = return ()
581 | isWiredInName name = return () -- No checking for wired-in names. In particular,
582 -- 'error' is handled by a rather gross hack
583 -- (see comments in GHC.Err.hs-boot)
585 -- Check that the actual module exports the same thing
586 | not (null missing_names)
587 = addErrAt (nameSrcSpan (head missing_names))
588 (missingBootThing (head missing_names) "exported by")
590 -- If the boot module does not *define* the thing, we are done
591 -- (it simply re-exports it, and names match, so nothing further to do)
592 | isNothing mb_boot_thing = return ()
594 -- Check that the actual module also defines the thing, and
595 -- then compare the definitions
596 | Just real_thing <- lookupTypeEnv local_type_env name,
597 Just boot_thing <- mb_boot_thing
598 = when (not (checkBootDecl boot_thing real_thing))
599 $ addErrAt (nameSrcSpan (getName boot_thing))
600 (let boot_decl = tyThingToIfaceDecl
601 (fromJust mb_boot_thing)
602 real_decl = tyThingToIfaceDecl real_thing
603 in bootMisMatch real_thing boot_decl real_decl)
606 = addErrTc (missingBootThing name "defined in")
608 name = availName boot_avail
609 mb_boot_thing = lookupTypeEnv boot_type_env name
610 missing_names = case lookupNameEnv local_export_env name of
612 Just avail -> availNames boot_avail `minusList` availNames avail
614 dfun_names = map getName boot_insts
616 local_export_env :: NameEnv AvailInfo
617 local_export_env = availsToNameEnv local_exports
619 check_inst :: Instance -> TcM (Maybe (Id, Id))
620 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
622 = case [dfun | inst <- local_insts,
623 let dfun = instanceDFunId inst,
624 idType dfun `tcEqType` boot_inst_ty ] of
625 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
626 (dfun:_) -> return (Just (local_boot_dfun, dfun))
628 boot_dfun = instanceDFunId boot_inst
629 boot_inst_ty = idType boot_dfun
630 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
633 -- This has to compare the TyThing from the .hi-boot file to the TyThing
634 -- in the current source file. We must be careful to allow alpha-renaming
635 -- where appropriate, and also the boot declaration is allowed to omit
636 -- constructors and class methods.
638 -- See rnfail055 for a good test of this stuff.
640 checkBootDecl :: TyThing -> TyThing -> Bool
642 checkBootDecl (AnId id1) (AnId id2)
644 (idType id1 `tcEqType` idType id2)
646 checkBootDecl (ATyCon tc1) (ATyCon tc2)
647 | isSynTyCon tc1 && isSynTyCon tc2
649 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
650 env = rnBndrs2 env0 tvs1 tvs2
652 eqSynRhs (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
653 = tcEqTypeX env k1 k2
654 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
655 = tcEqTypeX env t1 t2
657 equalLength tvs1 tvs2 &&
658 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
660 | isAlgTyCon tc1 && isAlgTyCon tc2
662 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2)
663 && eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
665 | isForeignTyCon tc1 && isForeignTyCon tc2
666 = tyConExtName tc1 == tyConExtName tc2
668 env0 = mkRnEnv2 emptyInScopeSet
670 eqAlgRhs AbstractTyCon _ = True
671 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
672 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
673 eqListBy eqCon (data_cons tc1) (data_cons tc2)
674 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
675 eqCon (data_con tc1) (data_con tc2)
679 = dataConName c1 == dataConName c2
680 && dataConIsInfix c1 == dataConIsInfix c2
681 && dataConStrictMarks c1 == dataConStrictMarks c2
682 && dataConFieldLabels c1 == dataConFieldLabels c2
683 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
684 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
685 env = rnBndrs2 env0 tvs1 tvs2
687 equalLength tvs1 tvs2 &&
688 eqListBy (tcEqPredX env)
689 (dataConEqTheta c1 ++ dataConDictTheta c1)
690 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
691 eqListBy (tcEqTypeX env)
692 (dataConOrigArgTys c1)
693 (dataConOrigArgTys c2)
695 checkBootDecl (AClass c1) (AClass c2)
697 (clas_tyvars1, clas_fds1, sc_theta1, _, _, op_stuff1)
698 = classExtraBigSig c1
699 (clas_tyvars2, clas_fds2, sc_theta2, _, _, op_stuff2)
700 = classExtraBigSig c2
702 env0 = mkRnEnv2 emptyInScopeSet
703 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
705 eqSig (id1, def_meth1) (id2, def_meth2)
706 = idName id1 == idName id2 &&
707 tcEqTypeX env op_ty1 op_ty2
709 (_, rho_ty1) = splitForAllTys (idType id1)
710 op_ty1 = funResultTy rho_ty1
711 (_, rho_ty2) = splitForAllTys (idType id2)
712 op_ty2 = funResultTy rho_ty2
714 eqFD (as1,bs1) (as2,bs2) =
715 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
716 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
718 equalLength clas_tyvars1 clas_tyvars2 &&
719 eqListBy eqFD clas_fds1 clas_fds2 &&
720 (null sc_theta1 && null op_stuff1
722 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
723 eqListBy eqSig op_stuff1 op_stuff2)
725 checkBootDecl (ADataCon dc1) (ADataCon dc2)
726 = pprPanic "checkBootDecl" (ppr dc1)
728 checkBootDecl _ _ = False -- probably shouldn't happen
731 missingBootThing thing what
732 = ppr thing <+> ptext (sLit "is exported by the hs-boot file, but not")
733 <+> text what <+> ptext (sLit "the module")
735 bootMisMatch thing boot_decl real_decl
736 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
737 ptext (sLit "Main module:") <+> ppr real_decl,
738 ptext (sLit "Boot file: ") <+> ppr boot_decl]
742 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
746 %************************************************************************
748 Type-checking the top level of a module
750 %************************************************************************
752 tcRnGroup takes a bunch of top-level source-code declarations, and
754 * gets supporting declarations from interface files
757 * and augments the TcGblEnv with the results
759 In Template Haskell it may be called repeatedly for each group of
760 declarations. It expects there to be an incoming TcGblEnv in the
761 monad; it augments it and returns the new TcGblEnv.
764 ------------------------------------------------
765 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
766 -- Fails if there are any errors
768 = do { -- Rename the source decls
769 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
771 -- save the renamed syntax, if we want it
773 | Just grp <- tcg_rn_decls tcg_env
774 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
778 -- Dump trace of renaming part
779 rnDump (ppr rn_decls) ;
781 return (tcg_env', rn_decls)
784 ------------------------------------------------
785 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
786 tcTopSrcDecls boot_details
787 (HsGroup { hs_tyclds = tycl_decls,
788 hs_instds = inst_decls,
789 hs_derivds = deriv_decls,
790 hs_fords = foreign_decls,
791 hs_defds = default_decls,
792 hs_annds = annotation_decls,
793 hs_ruleds = rule_decls,
794 hs_valds = val_binds })
795 = do { -- Type-check the type and class decls, and all imported decls
796 -- The latter come in via tycl_decls
797 traceTc (text "Tc2") ;
799 (tcg_env, aux_binds) <- tcTyAndClassDecls boot_details tycl_decls ;
800 -- If there are any errors, tcTyAndClassDecls fails here
802 setGblEnv tcg_env $ do {
803 -- Source-language instances, including derivings,
804 -- and import the supporting declarations
805 traceTc (text "Tc3") ;
806 (tcg_env, inst_infos, deriv_binds)
807 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
808 setGblEnv tcg_env $ do {
810 -- Foreign import declarations next.
811 traceTc (text "Tc4") ;
812 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
813 tcExtendGlobalValEnv fi_ids $ do {
815 -- Default declarations
816 traceTc (text "Tc4a") ;
817 default_tys <- tcDefaults default_decls ;
818 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
820 -- Now GHC-generated derived bindings, generics, and selectors
821 -- Do not generate warnings from compiler-generated code;
822 -- hence the use of discardWarnings
823 (tc_aux_binds, tcl_env) <- discardWarnings (tcTopBinds aux_binds) ;
824 (tc_deriv_binds, tcl_env) <- setLclTypeEnv tcl_env $
825 discardWarnings (tcTopBinds deriv_binds) ;
827 -- Value declarations next
828 traceTc (text "Tc5") ;
829 (tc_val_binds, tcl_env) <- setLclTypeEnv tcl_env $
830 tcTopBinds val_binds;
832 -- Second pass over class and instance declarations,
833 traceTc (text "Tc6") ;
834 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $
835 tcInstDecls2 tycl_decls inst_infos ;
836 showLIE (text "after instDecls2") ;
838 setLclTypeEnv tcl_env $ do { -- Environment doesn't change now
841 traceTc (text "Tc7") ;
842 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
845 annotations <- tcAnnotations annotation_decls ;
848 rules <- tcRules rule_decls ;
851 traceTc (text "Tc7a") ;
852 tcg_env <- getGblEnv ;
853 let { all_binds = tc_val_binds `unionBags`
854 tc_deriv_binds `unionBags`
855 tc_aux_binds `unionBags`
856 inst_binds `unionBags`
859 -- Extend the GblEnv with the (as yet un-zonked)
860 -- bindings, rules, foreign decls
861 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
862 tcg_rules = tcg_rules tcg_env ++ rules,
863 tcg_anns = tcg_anns tcg_env ++ annotations,
864 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
865 return (tcg_env', tcl_env)
870 %************************************************************************
874 %************************************************************************
877 checkMain :: TcM TcGblEnv
878 -- If we are in module Main, check that 'main' is defined.
880 = do { tcg_env <- getGblEnv ;
882 check_main dflags tcg_env
885 check_main dflags tcg_env
887 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
891 = do { mb_main <- lookupGlobalOccRn_maybe main_fn
892 -- Check that 'main' is in scope
893 -- It might be imported from another module!
895 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
900 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
901 ; let loc = srcLocSpan (getSrcLoc main_name)
902 ; ioTyCon <- tcLookupTyCon ioTyConName
903 ; (main_expr, res_ty)
904 <- addErrCtxt mainCtxt $
905 withBox liftedTypeKind $ \res_ty ->
906 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
908 -- See Note [Root-main Id]
909 -- Construct the binding
910 -- :Main.main :: IO res_ty = runMainIO res_ty main
911 ; run_main_id <- tcLookupId runMainIOName
912 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
913 (mkVarOccFS (fsLit "main"))
914 (getSrcSpan main_name)
915 ; root_main_id = Id.mkExportedLocalId root_main_name
916 (mkTyConApp ioTyCon [res_ty])
917 ; co = mkWpTyApps [res_ty]
918 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
919 ; main_bind = noLoc (VarBind root_main_id rhs) }
921 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
923 tcg_dus = tcg_dus tcg_env
924 `plusDU` usesOnly (unitFV main_name)
925 -- Record the use of 'main', so that we don't
926 -- complain about it being defined but not used
930 mod = tcg_mod tcg_env
931 main_mod = mainModIs dflags
932 main_fn = getMainFun dflags
934 complain_no_main | ghcLink dflags == LinkInMemory = return ()
935 | otherwise = failWithTc noMainMsg
936 -- In interactive mode, don't worry about the absence of 'main'
937 -- In other modes, fail altogether, so that we don't go on
938 -- and complain a second time when processing the export list.
940 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
941 noMainMsg = ptext (sLit "The") <+> pp_main_fn
942 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
943 pp_main_fn | main_fn == main_RDR_Unqual = ptext (sLit "function") <+> quotes (ppr main_fn)
944 | otherwise = ptext (sLit "main function") <+> quotes (ppr main_fn)
946 -- | Get the unqualified name of the function to use as the \"main\" for the main module.
947 -- Either returns the default name or the one configured on the command line with -main-is
948 getMainFun :: DynFlags -> RdrName
949 getMainFun dflags = case (mainFunIs dflags) of
950 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
951 Nothing -> main_RDR_Unqual
956 The function that the RTS invokes is always :Main.main, which we call
957 root_main_id. (Because GHC allows the user to have a module not
958 called Main as the main module, we can't rely on the main function
959 being called "Main.main". That's why root_main_id has a fixed module
962 This is unusual: it's a LocalId whose Name has a Module from another
963 module. Tiresomely, we must filter it out again in MkIface, les we
964 get two defns for 'main' in the interface file!
967 %*********************************************************
971 %*********************************************************
975 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
976 setInteractiveContext hsc_env icxt thing_inside
977 = let -- Initialise the tcg_inst_env with instances from all home modules.
978 -- This mimics the more selective call to hptInstances in tcRnModule.
979 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
981 updGblEnv (\env -> env {
982 tcg_rdr_env = ic_rn_gbl_env icxt,
983 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
984 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
988 tcExtendGhciEnv (ic_tmp_ids icxt) $
989 -- tcExtendGhciEnv does lots:
990 -- - it extends the local type env (tcl_env) with the given Ids,
991 -- - it extends the local rdr env (tcl_rdr) with the Names from
993 -- - it adds the free tyvars of the Ids to the tcl_tyvars
996 -- later ids in ic_tmp_ids must shadow earlier ones with the same
997 -- OccName, and tcExtendIdEnv implements this behaviour.
999 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
1006 -> InteractiveContext
1008 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1009 -- The returned [Id] is the list of new Ids bound by
1010 -- this statement. It can be used to extend the
1011 -- InteractiveContext via extendInteractiveContext.
1013 -- The returned TypecheckedHsExpr is of type IO [ () ],
1014 -- a list of the bound values, coerced to ().
1016 tcRnStmt hsc_env ictxt rdr_stmt
1017 = initTcPrintErrors hsc_env iNTERACTIVE $
1018 setInteractiveContext hsc_env ictxt $ do {
1020 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1021 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
1022 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1024 rnDump (ppr rn_stmt) ;
1026 -- The real work is done here
1027 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1028 zonked_expr <- zonkTopLExpr tc_expr ;
1029 zonked_ids <- zonkTopBndrs bound_ids ;
1031 -- None of the Ids should be of unboxed type, because we
1032 -- cast them all to HValues in the end!
1033 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1035 traceTc (text "tcs 1") ;
1036 let { global_ids = map globaliseAndTidyId zonked_ids } ;
1037 -- Note [Interactively-bound Ids in GHCi]
1039 {- ---------------------------------------------
1040 At one stage I removed any shadowed bindings from the type_env;
1041 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1042 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1044 Prelude> let f n = n * 2 :: Int
1045 Prelude> fName <- runQ [| f |]
1046 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1048 Prelude> let f n = n * 3 :: Int
1049 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1050 In the last line we use 'fName', which resolves to the *first* 'f'
1051 in scope. If we delete it from the type env, GHCi crashes because
1052 it doesn't expect that.
1054 Hence this code is commented out
1056 -------------------------------------------------- -}
1058 dumpOptTcRn Opt_D_dump_tc
1059 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1060 text "Typechecked expr" <+> ppr zonked_expr]) ;
1062 return (global_ids, zonked_expr)
1065 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1066 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1069 Note [Interactively-bound Ids in GHCi]
1070 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1071 The Ids bound by previous Stmts in Template Haskell are currently
1073 b) with an Internal Name (not External)
1074 c) and a tidied type
1076 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1077 compile an expression using these ids later, the byte code
1078 generator will consider the occurrences to be free rather than
1081 (b) They retain their Internal names becuase we don't have a suitable
1082 Module to name them with. We could revisit this choice.
1084 (c) Their types are tidied. This is important, because :info may ask
1085 to look at them, and :info expects the things it looks up to have
1089 --------------------------------------------------------------------------
1090 Typechecking Stmts in GHCi
1092 Here is the grand plan, implemented in tcUserStmt
1094 What you type The IO [HValue] that hscStmt returns
1095 ------------- ------------------------------------
1096 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1099 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1102 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1103 [NB: result not printed] bindings: [it]
1105 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1106 result showable) bindings: [it]
1108 expr (of non-IO type,
1109 result not showable) ==> error
1113 ---------------------------
1114 type PlanResult = ([Id], LHsExpr Id)
1115 type Plan = TcM PlanResult
1117 runPlans :: [Plan] -> TcM PlanResult
1118 -- Try the plans in order. If one fails (by raising an exn), try the next.
1119 -- If one succeeds, take it.
1120 runPlans [] = panic "runPlans"
1122 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1124 --------------------
1125 mkPlan :: LStmt Name -> TcM PlanResult
1126 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1127 = do { uniq <- newUnique -- is treated very specially
1128 ; let fresh_it = itName uniq
1129 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1130 matches = [mkMatch [] expr emptyLocalBinds]
1131 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1132 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1133 (HsVar bindIOName) noSyntaxExpr
1134 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1135 (HsVar thenIOName) placeHolderType
1138 -- [it <- e; print it] but not if it::()
1140 -- [let it = e; print it]
1141 ; runPlans [ -- Plan A
1142 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1143 ; it_ty <- zonkTcType (idType it_id)
1144 ; when (isUnitTy it_ty) failM
1147 -- Plan B; a naked bind statment
1148 tcGhciStmts [bind_stmt],
1150 -- Plan C; check that the let-binding is typeable all by itself.
1151 -- If not, fail; if so, try to print it.
1152 -- The two-step process avoids getting two errors: one from
1153 -- the expression itself, and one from the 'print it' part
1154 -- This two-step story is very clunky, alas
1155 do { checkNoErrs (tcGhciStmts [let_stmt])
1156 --- checkNoErrs defeats the error recovery of let-bindings
1157 ; tcGhciStmts [let_stmt, print_it] }
1160 mkPlan stmt@(L loc (BindStmt {}))
1161 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1162 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1163 (HsVar thenIOName) placeHolderType
1165 ; print_bind_result <- doptM Opt_PrintBindResult
1166 ; let print_plan = do
1167 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1168 ; v_ty <- zonkTcType (idType v_id)
1169 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1173 -- [stmt; print v] but not if v::()
1175 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1176 [tcGhciStmts [stmt]])
1180 = tcGhciStmts [stmt]
1182 ---------------------------
1183 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1185 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1186 ret_id <- tcLookupId returnIOName ; -- return @ IO
1188 ret_ty = mkListTy unitTy ;
1189 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1190 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1192 names = map unLoc (collectLStmtsBinders stmts) ;
1194 -- mk_return builds the expression
1195 -- returnIO @ [()] [coerce () x, .., coerce () z]
1197 -- Despite the inconvenience of building the type applications etc,
1198 -- this *has* to be done in type-annotated post-typecheck form
1199 -- because we are going to return a list of *polymorphic* values
1200 -- coerced to type (). If we built a *source* stmt
1201 -- return [coerce x, ..., coerce z]
1202 -- then the type checker would instantiate x..z, and we wouldn't
1203 -- get their *polymorphic* values. (And we'd get ambiguity errs
1204 -- if they were overloaded, since they aren't applied to anything.)
1205 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1206 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1207 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1211 -- OK, we're ready to typecheck the stmts
1212 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1213 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1214 mapM tcLookupId names ;
1215 -- Look up the names right in the middle,
1216 -- where they will all be in scope
1218 -- Simplify the context
1219 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1220 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1221 -- checkNoErrs ensures that the plan fails if context redn fails
1223 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1224 return (ids, mkHsDictLet const_binds $
1225 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1230 tcRnExpr just finds the type of an expression
1234 -> InteractiveContext
1236 -> IO (Messages, Maybe Type)
1237 tcRnExpr hsc_env ictxt rdr_expr
1238 = initTcPrintErrors hsc_env iNTERACTIVE $
1239 setInteractiveContext hsc_env ictxt $ do {
1241 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1244 -- Now typecheck the expression;
1245 -- it might have a rank-2 type (e.g. :t runST)
1246 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1247 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1248 tcSimplifyInteractive lie_top ;
1250 let { all_expr_ty = mkForAllTys qtvs $
1251 mkFunTys (map (idType . instToId) dict_insts) $
1253 zonkTcType all_expr_ty
1256 smpl_doc = ptext (sLit "main expression")
1259 tcRnType just finds the kind of a type
1263 -> InteractiveContext
1265 -> IO (Messages, Maybe Kind)
1266 tcRnType hsc_env ictxt rdr_type
1267 = initTcPrintErrors hsc_env iNTERACTIVE $
1268 setInteractiveContext hsc_env ictxt $ do {
1270 rn_type <- rnLHsType doc rdr_type ;
1273 -- Now kind-check the type
1274 (ty', kind) <- kcLHsType rn_type ;
1278 doc = ptext (sLit "In GHCi input")
1284 %************************************************************************
1286 More GHCi stuff, to do with browsing and getting info
1288 %************************************************************************
1292 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1293 -- a package module with an interface on disk. If neither of these is
1294 -- true, then the result will be an error indicating the interface
1295 -- could not be found.
1296 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1297 getModuleExports hsc_env mod
1300 checkMods = ic_toplev_scope ic ++ ic_exports ic
1302 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1304 -- Get the export avail info and also load all orphan and family-instance
1305 -- modules. Finally, check that the family instances of all modules in the
1306 -- interactive context are consistent (these modules are in the second
1308 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1309 tcGetModuleExports mod directlyImpMods
1310 = do { let doc = ptext (sLit "context for compiling statements")
1311 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1313 -- Load any orphan-module and family instance-module
1314 -- interfaces, so their instances are visible.
1315 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1316 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1318 -- Check that the family instances of all directly loaded
1319 -- modules are consistent.
1320 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1322 ; ifaceExportNames (mi_exports iface)
1325 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1326 tcRnLookupRdrName hsc_env rdr_name
1327 = initTcPrintErrors hsc_env iNTERACTIVE $
1328 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1329 lookup_rdr_name rdr_name
1331 lookup_rdr_name rdr_name = do {
1332 -- If the identifier is a constructor (begins with an
1333 -- upper-case letter), then we need to consider both
1334 -- constructor and type class identifiers.
1335 let { rdr_names = dataTcOccs rdr_name } ;
1337 -- results :: [Either Messages Name]
1338 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1340 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1341 -- The successful lookups will be (Just name)
1342 let { (warns_s, good_names) = unzip [ (msgs, name)
1343 | (msgs, Just name) <- results] ;
1344 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1346 -- Fail if nothing good happened, else add warnings
1347 if null good_names then
1348 -- No lookup succeeded, so
1349 -- pick the first error message and report it
1350 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1351 -- while the other is "X is not in scope",
1352 -- we definitely want the former; but we might pick the latter
1353 do { addMessages (head errs_s) ; failM }
1354 else -- Add deprecation warnings
1355 mapM_ addMessages warns_s ;
1360 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1361 tcRnLookupName hsc_env name
1362 = initTcPrintErrors hsc_env iNTERACTIVE $
1363 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1364 tcRnLookupName' name
1366 -- To look up a name we have to look in the local environment (tcl_lcl)
1367 -- as well as the global environment, which is what tcLookup does.
1368 -- But we also want a TyThing, so we have to convert:
1370 tcRnLookupName' :: Name -> TcRn TyThing
1371 tcRnLookupName' name = do
1372 tcthing <- tcLookup name
1374 AGlobal thing -> return thing
1375 ATcId{tct_id=id} -> return (AnId id)
1376 _ -> panic "tcRnLookupName'"
1378 tcRnGetInfo :: HscEnv
1380 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1382 -- Used to implemnent :info in GHCi
1384 -- Look up a RdrName and return all the TyThings it might be
1385 -- A capitalised RdrName is given to us in the DataName namespace,
1386 -- but we want to treat it as *both* a data constructor
1387 -- *and* as a type or class constructor;
1388 -- hence the call to dataTcOccs, and we return up to two results
1389 tcRnGetInfo hsc_env name
1390 = initTcPrintErrors hsc_env iNTERACTIVE $
1391 let ictxt = hsc_IC hsc_env in
1392 setInteractiveContext hsc_env ictxt $ do
1394 -- Load the interface for all unqualified types and classes
1395 -- That way we will find all the instance declarations
1396 -- (Packages have not orphan modules, and we assume that
1397 -- in the home package all relevant modules are loaded.)
1398 loadUnqualIfaces ictxt
1400 thing <- tcRnLookupName' name
1401 fixity <- lookupFixityRn name
1402 ispecs <- lookupInsts thing
1403 return (thing, fixity, ispecs)
1405 lookupInsts :: TyThing -> TcM [Instance]
1406 lookupInsts (AClass cls)
1407 = do { inst_envs <- tcGetInstEnvs
1408 ; return (classInstances inst_envs cls) }
1410 lookupInsts (ATyCon tc)
1411 = do { eps <- getEps -- Load all instances for all classes that are
1412 -- in the type environment (which are all the ones
1413 -- we've seen in any interface file so far)
1414 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1416 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1417 , let dfun = instanceDFunId ispec
1420 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1421 tc_name = tyConName tc
1423 lookupInsts other = return []
1425 loadUnqualIfaces :: InteractiveContext -> TcM ()
1426 -- Load the home module for everything that is in scope unqualified
1427 -- This is so that we can accurately report the instances for
1429 loadUnqualIfaces ictxt
1431 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1433 unqual_mods = [ nameModule name
1434 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1435 let name = gre_name gre,
1436 not (isInternalName name),
1437 isTcOcc (nameOccName name), -- Types and classes only
1438 unQualOK gre ] -- In scope unqualified
1439 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1443 %************************************************************************
1447 %************************************************************************
1450 rnDump :: SDoc -> TcRn ()
1451 -- Dump, with a banner, if -ddump-rn
1452 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1454 tcDump :: TcGblEnv -> TcRn ()
1456 = do { dflags <- getDOpts ;
1458 -- Dump short output if -ddump-types or -ddump-tc
1459 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1460 (dumpTcRn short_dump) ;
1462 -- Dump bindings if -ddump-tc
1463 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1466 short_dump = pprTcGblEnv env
1467 full_dump = pprLHsBinds (tcg_binds env)
1468 -- NB: foreign x-d's have undefined's in their types;
1469 -- hence can't show the tc_fords
1472 = do { dflags <- getDOpts ;
1473 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1474 (dumpTcRn (pprModGuts mod_guts)) ;
1476 -- Dump bindings if -ddump-tc
1477 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1479 full_dump = pprCoreBindings (mg_binds mod_guts)
1481 -- It's unpleasant having both pprModGuts and pprModDetails here
1482 pprTcGblEnv :: TcGblEnv -> SDoc
1483 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1485 tcg_fam_insts = fam_insts,
1487 tcg_imports = imports })
1488 = vcat [ ppr_types insts type_env
1489 , ppr_tycons fam_insts type_env
1491 , ppr_fam_insts fam_insts
1492 , vcat (map ppr rules)
1493 , ppr_gen_tycons (typeEnvTyCons type_env)
1494 , ptext (sLit "Dependent modules:") <+>
1495 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1496 , ptext (sLit "Dependent packages:") <+>
1497 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1498 where -- The two uses of sortBy are just to reduce unnecessary
1499 -- wobbling in testsuite output
1500 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1501 = (mod_name1 `stableModuleNameCmp` mod_name2)
1503 (is_boot1 `compare` is_boot2)
1505 pprModGuts :: ModGuts -> SDoc
1506 pprModGuts (ModGuts { mg_types = type_env,
1508 = vcat [ ppr_types [] type_env,
1511 ppr_types :: [Instance] -> TypeEnv -> SDoc
1512 ppr_types insts type_env
1513 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1515 dfun_ids = map instanceDFunId insts
1516 ids = [id | id <- typeEnvIds type_env, want_sig id]
1517 want_sig id | opt_PprStyle_Debug = True
1518 | otherwise = isLocalId id &&
1519 isExternalName (idName id) &&
1520 not (id `elem` dfun_ids)
1521 -- isLocalId ignores data constructors, records selectors etc.
1522 -- The isExternalName ignores local dictionary and method bindings
1523 -- that the type checker has invented. Top-level user-defined things
1524 -- have External names.
1526 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1527 ppr_tycons fam_insts type_env
1528 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1530 fi_tycons = map famInstTyCon fam_insts
1531 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1532 want_tycon tycon | opt_PprStyle_Debug = True
1533 | otherwise = not (isImplicitTyCon tycon) &&
1534 isExternalName (tyConName tycon) &&
1535 not (tycon `elem` fi_tycons)
1537 ppr_insts :: [Instance] -> SDoc
1538 ppr_insts [] = empty
1539 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1541 ppr_fam_insts :: [FamInst] -> SDoc
1542 ppr_fam_insts [] = empty
1543 ppr_fam_insts fam_insts =
1544 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1546 ppr_sigs :: [Var] -> SDoc
1548 -- Print type signatures; sort by OccName
1549 = vcat (map ppr_sig (sortLe le_sig ids))
1551 le_sig id1 id2 = getOccName id1 <= getOccName id2
1552 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1554 ppr_tydecls :: [TyCon] -> SDoc
1556 -- Print type constructor info; sort by OccName
1557 = vcat (map ppr_tycon (sortLe le_sig tycons))
1559 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1561 | isCoercionTyCon tycon = ptext (sLit "coercion") <+> ppr tycon
1562 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1564 ppr_rules :: [CoreRule] -> SDoc
1565 ppr_rules [] = empty
1566 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1567 nest 4 (pprRules rs),
1570 ppr_gen_tycons [] = empty
1571 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1572 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]