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 )
60 import TcUnify ( withBox )
87 import Data.List ( sortBy )
99 import {- Kind parts of -} Type
101 import Foreign.Ptr( Ptr )
102 import TidyPgm ( globaliseAndTidyId )
111 import Data.Maybe ( isJust )
113 #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
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 -- Check that main is exported (must be after rnExports)
182 checkMainExported tcg_env ;
184 -- Compare the hi-boot iface (if any) with the real thing
185 -- Must be done after processing the exports
186 tcg_env <- checkHiBootIface tcg_env boot_iface ;
188 -- The new type env is already available to stuff slurped from
189 -- interface files, via TcEnv.updateGlobalTypeEnv
190 -- It's important that this includes the stuff in checkHiBootIface,
191 -- because the latter might add new bindings for boot_dfuns,
192 -- which may be mentioned in imported unfoldings
194 -- Don't need to rename the Haddock documentation,
195 -- it's not parsed by GHC anymore.
196 tcg_env <- return (tcg_env { tcg_doc_hdr = maybe_doc_hdr }) ;
198 -- Report unused names
199 reportUnusedNames export_ies tcg_env ;
201 -- Dump output and return
208 %************************************************************************
212 %************************************************************************
215 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
216 tcRnImports hsc_env this_mod import_decls
217 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
219 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
220 ; dep_mods = imp_dep_mods imports
222 -- We want instance declarations from all home-package
223 -- modules below this one, including boot modules, except
224 -- ourselves. The 'except ourselves' is so that we don't
225 -- get the instances from this module's hs-boot file
226 ; want_instances :: ModuleName -> Bool
227 ; want_instances mod = mod `elemUFM` dep_mods
228 && mod /= moduleName this_mod
229 ; (home_insts, home_fam_insts) = hptInstances hsc_env
233 -- Record boot-file info in the EPS, so that it's
234 -- visible to loadHiBootInterface in tcRnSrcDecls,
235 -- and any other incrementally-performed imports
236 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
238 -- Update the gbl env
239 ; updGblEnv ( \ gbl ->
241 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
242 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
243 tcg_rn_imports = rn_imports,
244 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
245 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
250 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
251 -- Fail if there are any errors so far
252 -- The error printing (if needed) takes advantage
253 -- of the tcg_env we have now set
254 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
257 -- Load any orphan-module and family instance-module
258 -- interfaces, so that their rules and instance decls will be
260 ; loadOrphanModules (imp_orphs imports) False
261 ; loadOrphanModules (imp_finsts imports) True
263 -- Check type-familily consistency
264 ; traceRn (text "rn1: checking family instance consistency")
265 ; let { dir_imp_mods = moduleEnvKeys
268 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
274 %************************************************************************
276 Type-checking external-core modules
278 %************************************************************************
281 tcRnExtCore :: HscEnv
283 -> IO (Messages, Maybe ModGuts)
284 -- Nothing => some error occurred
286 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
287 -- The decls are IfaceDecls; all names are original names
288 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
290 initTc hsc_env ExtCoreFile False this_mod $ do {
292 let { ldecls = map noLoc decls } ;
294 -- bring the type and class decls into scope
295 -- ToDo: check that this doesn't need to extract the val binds.
296 -- It seems that only the type and class decls need to be in scope below because
297 -- (a) tcTyAndClassDecls doesn't need the val binds, and
298 -- (b) tcExtCoreBindings doesn't need anything
299 -- (in fact, it might not even need to be in the scope of
300 -- this tcg_env at all)
301 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
302 tc_envs <- extendGlobalRdrEnvRn avails emptyFsEnv {- no fixity decls -} ;
304 setEnvs tc_envs $ do {
306 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
308 -- Dump trace of renaming part
309 rnDump (ppr rn_decls) ;
311 -- Typecheck them all together so that
312 -- any mutually recursive types are done right
313 -- Just discard the auxiliary bindings; they are generated
314 -- only for Haskell source code, and should already be in Core
315 (tcg_env, _aux_binds) <- tcTyAndClassDecls emptyModDetails rn_decls ;
317 setGblEnv tcg_env $ do {
318 -- Make the new type env available to stuff slurped from interface files
320 -- Now the core bindings
321 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
325 bndrs = bindersOfBinds core_binds ;
326 my_exports = map (Avail . idName) bndrs ;
327 -- ToDo: export the data types also?
330 extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
332 mod_guts = ModGuts { mg_module = this_mod,
334 mg_used_names = emptyNameSet, -- ToDo: compute usage
335 mg_dir_imps = emptyModuleEnv, -- ??
336 mg_deps = noDependencies, -- ??
337 mg_exports = my_exports,
338 mg_types = final_type_env,
339 mg_insts = tcg_insts tcg_env,
340 mg_fam_insts = tcg_fam_insts tcg_env,
341 mg_inst_env = tcg_inst_env tcg_env,
342 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
344 mg_binds = core_binds,
347 mg_rdr_env = emptyGlobalRdrEnv,
348 mg_fix_env = emptyFixityEnv,
349 mg_warns = NoWarnings,
350 mg_foreign = NoStubs,
351 mg_hpc_info = emptyHpcInfo False,
352 mg_modBreaks = emptyModBreaks,
353 mg_vect_info = noVectInfo
356 tcCoreDump mod_guts ;
361 mkFakeGroup decls -- Rather clumsy; lots of unused fields
362 = emptyRdrGroup { hs_tyclds = decls }
366 %************************************************************************
368 Type-checking the top level of a module
370 %************************************************************************
373 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
374 -- Returns the variables free in the decls
375 -- Reason: solely to report unused imports and bindings
376 tcRnSrcDecls boot_iface decls
377 = do { -- Do all the declarations
378 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
380 -- Finish simplifying class constraints
382 -- tcSimplifyTop deals with constant or ambiguous InstIds.
383 -- How could there be ambiguous ones? They can only arise if a
384 -- top-level decl falls under the monomorphism restriction
385 -- and no subsequent decl instantiates its type.
387 -- We do this after checkMain, so that we use the type info
388 -- thaat checkMain adds
390 -- We do it with both global and local env in scope:
391 -- * the global env exposes the instances to tcSimplifyTop
392 -- * the local env exposes the local Ids to tcSimplifyTop,
393 -- so that we get better error messages (monomorphism restriction)
394 traceTc (text "Tc8") ;
395 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
397 -- Backsubstitution. This must be done last.
398 -- Even tcSimplifyTop may do some unification.
399 traceTc (text "Tc9") ;
400 let { (tcg_env, _) = tc_envs
401 ; TcGblEnv { tcg_type_env = type_env,
404 tcg_fords = fords } = tcg_env
405 ; all_binds = binds `unionBags` inst_binds } ;
407 failIfErrsM ; -- Don't zonk if there have been errors
408 -- It's a waste of time; and we may get debug warnings
409 -- about strangely-typed TyCons!
411 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
414 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
415 ; tcg_env' = tcg_env { tcg_binds = binds',
417 tcg_fords = fords' } } ;
419 setGlobalTypeEnv tcg_env' final_type_env
422 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
423 -- Loops around dealing with each top level inter-splice group
424 -- in turn, until it's dealt with the entire module
425 tc_rn_src_decls boot_details ds
426 = do { let { (first_group, group_tail) = findSplice ds } ;
427 -- If ds is [] we get ([], Nothing)
429 -- Deal with decls up to, but not including, the first splice
430 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
431 -- rnTopSrcDecls fails if there are any errors
433 (tcg_env, tcl_env) <- setGblEnv tcg_env $
434 tcTopSrcDecls boot_details rn_decls ;
436 -- If there is no splice, we're nearly done
437 setEnvs (tcg_env, tcl_env) $
439 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
440 return (tcg_env, tcl_env)
443 -- If there's a splice, we must carry on
444 Just (SpliceDecl splice_expr, rest_ds) -> do {
446 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
449 -- Rename the splice expression, and get its supporting decls
450 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
451 -- checkNoErrs: don't typecheck if renaming failed
452 rnDump (ppr rn_splice_expr) ;
454 -- Execute the splice
455 spliced_decls <- tcSpliceDecls rn_splice_expr ;
457 -- Glue them on the front of the remaining decls and loop
458 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
459 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
464 %************************************************************************
466 Compiling hs-boot source files, and
467 comparing the hi-boot interface with the real thing
469 %************************************************************************
472 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
473 tcRnHsBootDecls decls
474 = do { let { (first_group, group_tail) = findSplice decls }
477 Just stuff -> spliceInHsBootErr stuff
480 -- Rename the declarations
481 ; (tcg_env, HsGroup {
482 hs_tyclds = tycl_decls,
483 hs_instds = inst_decls,
484 hs_derivds = deriv_decls,
486 hs_defds = _, -- Todo: check no foreign decls, no rules,
487 hs_ruleds = _, -- no default decls and no annotation decls
489 hs_valds = val_binds }) <- rnTopSrcDecls first_group
490 ; setGblEnv tcg_env $ do {
493 -- Typecheck type/class decls
494 ; traceTc (text "Tc2")
495 ; (tcg_env, aux_binds) <- tcTyAndClassDecls emptyModDetails tycl_decls
496 ; setGblEnv tcg_env $ do {
498 -- Typecheck instance decls
499 ; traceTc (text "Tc3")
500 ; (tcg_env, inst_infos, _deriv_binds)
501 <- tcInstDecls1 tycl_decls inst_decls deriv_decls
502 ; setGblEnv tcg_env $ do {
504 -- Typecheck value declarations
505 ; traceTc (text "Tc5")
506 ; val_ids <- tcHsBootSigs val_binds
509 -- No simplification or zonking to do
510 ; traceTc (text "Tc7a")
511 ; gbl_env <- getGblEnv
513 -- Make the final type-env
514 -- Include the dfun_ids so that their type sigs
515 -- are written into the interface file.
516 -- And similarly the aux_ids from aux_binds
517 ; let { type_env0 = tcg_type_env gbl_env
518 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
519 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
520 ; type_env3 = extendTypeEnvWithIds type_env1 aux_ids
521 ; dfun_ids = map iDFunId inst_infos
522 ; aux_ids = case aux_binds of
523 ValBindsOut _ sigs -> [id | L _ (IdSig id) <- sigs]
524 _ -> panic "tcRnHsBoodDecls"
527 ; setGlobalTypeEnv gbl_env type_env2
530 spliceInHsBootErr (SpliceDecl (L loc _), _)
531 = addErrAt loc (ptext (sLit "Splices are not allowed in hs-boot files"))
534 Once we've typechecked the body of the module, we want to compare what
535 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
538 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
539 -- Compare the hi-boot file for this module (if there is one)
540 -- with the type environment we've just come up with
541 -- In the common case where there is no hi-boot file, the list
542 -- of boot_names is empty.
544 -- The bindings we return give bindings for the dfuns defined in the
545 -- hs-boot file, such as $fbEqT = $fEqT
548 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
549 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
550 tcg_type_env = local_type_env, tcg_exports = local_exports })
551 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
552 md_types = boot_type_env, md_exports = boot_exports })
553 | isHsBoot hs_src -- Current module is already a hs-boot file!
557 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
560 -- Check the exports of the boot module, one by one
561 ; mapM_ check_export boot_exports
563 -- Check instance declarations
564 ; mb_dfun_prs <- mapM check_inst boot_insts
565 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds,
566 tcg_type_env = extendTypeEnvWithIds local_type_env boot_dfuns }
567 dfun_prs = catMaybes mb_dfun_prs
568 boot_dfuns = map fst dfun_prs
569 dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun)
570 | (boot_dfun, dfun) <- dfun_prs ]
572 -- Check for no family instances
573 ; unless (null boot_fam_insts) $
574 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
575 "instances in boot files yet...")
576 -- FIXME: Why? The actual comparison is not hard, but what would
577 -- be the equivalent to the dfun bindings returned for class
578 -- instances? We can't easily equate tycons...
580 -- Check instance declarations
581 ; mb_dfun_prs <- mapM check_inst boot_insts
582 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
583 final_type_env = extendTypeEnvWithIds local_type_env boot_dfuns
584 dfun_prs = catMaybes mb_dfun_prs
585 boot_dfuns = map fst dfun_prs
586 dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun)
587 | (boot_dfun, dfun) <- dfun_prs ]
590 ; setGlobalTypeEnv tcg_env' final_type_env }
592 check_export boot_avail -- boot_avail is exported by the boot iface
593 | name `elem` dfun_names = return ()
594 | isWiredInName name = return () -- No checking for wired-in names. In particular,
595 -- 'error' is handled by a rather gross hack
596 -- (see comments in GHC.Err.hs-boot)
598 -- Check that the actual module exports the same thing
599 | not (null missing_names)
600 = addErrAt (nameSrcSpan (head missing_names))
601 (missingBootThing (head missing_names) "exported by")
603 -- If the boot module does not *define* the thing, we are done
604 -- (it simply re-exports it, and names match, so nothing further to do)
605 | isNothing mb_boot_thing = return ()
607 -- Check that the actual module also defines the thing, and
608 -- then compare the definitions
609 | Just real_thing <- lookupTypeEnv local_type_env name,
610 Just boot_thing <- mb_boot_thing
611 = when (not (checkBootDecl boot_thing real_thing))
612 $ addErrAt (nameSrcSpan (getName boot_thing))
613 (let boot_decl = tyThingToIfaceDecl
614 (fromJust mb_boot_thing)
615 real_decl = tyThingToIfaceDecl real_thing
616 in bootMisMatch real_thing boot_decl real_decl)
619 = addErrTc (missingBootThing name "defined in")
621 name = availName boot_avail
622 mb_boot_thing = lookupTypeEnv boot_type_env name
623 missing_names = case lookupNameEnv local_export_env name of
625 Just avail -> availNames boot_avail `minusList` availNames avail
627 dfun_names = map getName boot_insts
629 local_export_env :: NameEnv AvailInfo
630 local_export_env = availsToNameEnv local_exports
632 check_inst :: Instance -> TcM (Maybe (Id, Id))
633 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
635 = case [dfun | inst <- local_insts,
636 let dfun = instanceDFunId inst,
637 idType dfun `tcEqType` boot_inst_ty ] of
638 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
639 (dfun:_) -> return (Just (local_boot_dfun, dfun))
641 boot_dfun = instanceDFunId boot_inst
642 boot_inst_ty = idType boot_dfun
643 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
646 -- This has to compare the TyThing from the .hi-boot file to the TyThing
647 -- in the current source file. We must be careful to allow alpha-renaming
648 -- where appropriate, and also the boot declaration is allowed to omit
649 -- constructors and class methods.
651 -- See rnfail055 for a good test of this stuff.
653 checkBootDecl :: TyThing -> TyThing -> Bool
655 checkBootDecl (AnId id1) (AnId id2)
657 (idType id1 `tcEqType` idType id2)
659 checkBootDecl (ATyCon tc1) (ATyCon tc2)
660 = checkBootTyCon tc1 tc2
662 checkBootDecl (AClass c1) (AClass c2)
664 (clas_tyvars1, clas_fds1, sc_theta1, _, ats1, op_stuff1)
665 = classExtraBigSig c1
666 (clas_tyvars2, clas_fds2, sc_theta2, _, ats2, op_stuff2)
667 = classExtraBigSig c2
669 env0 = mkRnEnv2 emptyInScopeSet
670 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
672 eqSig (id1, def_meth1) (id2, def_meth2)
673 = idName id1 == idName id2 &&
674 tcEqTypeX env op_ty1 op_ty2
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 dc2)
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 (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
713 = tcEqTypeX env k1 k2
714 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
715 = tcEqTypeX env t1 t2
717 equalLength tvs1 tvs2 &&
718 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
720 | isAlgTyCon tc1 && isAlgTyCon tc2
722 eqKind (tyConKind tc1) (tyConKind tc2) &&
723 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2) &&
724 eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
726 | isForeignTyCon tc1 && isForeignTyCon tc2
727 = eqKind (tyConKind tc1) (tyConKind tc2) &&
728 tyConExtName tc1 == tyConExtName tc2
730 env0 = mkRnEnv2 emptyInScopeSet
732 eqAlgRhs AbstractTyCon _ = True
733 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
734 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
735 eqListBy eqCon (data_cons tc1) (data_cons tc2)
736 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
737 eqCon (data_con tc1) (data_con tc2)
741 = dataConName c1 == dataConName c2
742 && dataConIsInfix c1 == dataConIsInfix c2
743 && dataConStrictMarks c1 == dataConStrictMarks c2
744 && dataConFieldLabels c1 == dataConFieldLabels c2
745 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
746 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
747 env = rnBndrs2 env0 tvs1 tvs2
749 equalLength tvs1 tvs2 &&
750 eqListBy (tcEqPredX env)
751 (dataConEqTheta c1 ++ dataConDictTheta c1)
752 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
753 eqListBy (tcEqTypeX env)
754 (dataConOrigArgTys c1)
755 (dataConOrigArgTys c2)
758 missingBootThing thing what
759 = ppr thing <+> ptext (sLit "is exported by the hs-boot file, but not")
760 <+> text what <+> ptext (sLit "the module")
762 bootMisMatch thing boot_decl real_decl
763 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
764 ptext (sLit "Main module:") <+> ppr real_decl,
765 ptext (sLit "Boot file: ") <+> ppr boot_decl]
769 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
773 %************************************************************************
775 Type-checking the top level of a module
777 %************************************************************************
779 tcRnGroup takes a bunch of top-level source-code declarations, and
781 * gets supporting declarations from interface files
784 * and augments the TcGblEnv with the results
786 In Template Haskell it may be called repeatedly for each group of
787 declarations. It expects there to be an incoming TcGblEnv in the
788 monad; it augments it and returns the new TcGblEnv.
791 ------------------------------------------------
792 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
793 -- Fails if there are any errors
795 = do { -- Rename the source decls
796 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
798 -- save the renamed syntax, if we want it
800 | Just grp <- tcg_rn_decls tcg_env
801 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
805 -- Dump trace of renaming part
806 rnDump (ppr rn_decls) ;
808 return (tcg_env', rn_decls)
811 ------------------------------------------------
812 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
813 tcTopSrcDecls boot_details
814 (HsGroup { hs_tyclds = tycl_decls,
815 hs_instds = inst_decls,
816 hs_derivds = deriv_decls,
817 hs_fords = foreign_decls,
818 hs_defds = default_decls,
819 hs_annds = annotation_decls,
820 hs_ruleds = rule_decls,
821 hs_valds = val_binds })
822 = do { -- Type-check the type and class decls, and all imported decls
823 -- The latter come in via tycl_decls
824 traceTc (text "Tc2") ;
826 (tcg_env, aux_binds) <- tcTyAndClassDecls boot_details tycl_decls ;
827 -- If there are any errors, tcTyAndClassDecls fails here
829 setGblEnv tcg_env $ do {
830 -- Source-language instances, including derivings,
831 -- and import the supporting declarations
832 traceTc (text "Tc3") ;
833 (tcg_env, inst_infos, deriv_binds)
834 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
835 setGblEnv tcg_env $ do {
837 -- Foreign import declarations next.
838 traceTc (text "Tc4") ;
839 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
840 tcExtendGlobalValEnv fi_ids $ do {
842 -- Default declarations
843 traceTc (text "Tc4a") ;
844 default_tys <- tcDefaults default_decls ;
845 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
847 -- Now GHC-generated derived bindings, generics, and selectors
848 -- Do not generate warnings from compiler-generated code;
849 -- hence the use of discardWarnings
850 (tc_aux_binds, tcl_env) <- discardWarnings (tcTopBinds aux_binds) ;
851 (tc_deriv_binds, tcl_env) <- setLclTypeEnv tcl_env $
852 discardWarnings (tcTopBinds deriv_binds) ;
854 -- Value declarations next
855 traceTc (text "Tc5") ;
856 (tc_val_binds, tcl_env) <- setLclTypeEnv tcl_env $
857 tcTopBinds val_binds;
859 -- Second pass over class and instance declarations,
860 traceTc (text "Tc6") ;
861 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $
862 tcInstDecls2 tycl_decls inst_infos ;
863 showLIE (text "after instDecls2") ;
865 setLclTypeEnv tcl_env $ do { -- Environment doesn't change now
868 traceTc (text "Tc7") ;
869 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
872 annotations <- tcAnnotations annotation_decls ;
875 rules <- tcRules rule_decls ;
878 traceTc (text "Tc7a") ;
879 tcg_env <- getGblEnv ;
880 let { all_binds = tc_val_binds `unionBags`
881 tc_deriv_binds `unionBags`
882 tc_aux_binds `unionBags`
883 inst_binds `unionBags`
886 -- Extend the GblEnv with the (as yet un-zonked)
887 -- bindings, rules, foreign decls
888 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
889 tcg_rules = tcg_rules tcg_env ++ rules,
890 tcg_anns = tcg_anns tcg_env ++ annotations,
891 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
892 return (tcg_env', tcl_env)
897 %************************************************************************
901 %************************************************************************
904 checkMain :: TcM TcGblEnv
905 -- If we are in module Main, check that 'main' is defined.
907 = do { tcg_env <- getGblEnv ;
909 check_main dflags tcg_env
912 check_main dflags tcg_env
914 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
918 = do { mb_main <- lookupGlobalOccRn_maybe main_fn
919 -- Check that 'main' is in scope
920 -- It might be imported from another module!
922 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
927 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
928 ; let loc = srcLocSpan (getSrcLoc main_name)
929 ; ioTyCon <- tcLookupTyCon ioTyConName
930 ; (main_expr, res_ty)
931 <- addErrCtxt mainCtxt $
932 withBox liftedTypeKind $ \res_ty ->
933 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
935 -- See Note [Root-main Id]
936 -- Construct the binding
937 -- :Main.main :: IO res_ty = runMainIO res_ty main
938 ; run_main_id <- tcLookupId runMainIOName
939 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
940 (mkVarOccFS (fsLit "main"))
941 (getSrcSpan main_name)
942 ; root_main_id = Id.mkExportedLocalId root_main_name
943 (mkTyConApp ioTyCon [res_ty])
944 ; co = mkWpTyApps [res_ty]
945 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
946 ; main_bind = mkVarBind root_main_id rhs }
948 ; return (tcg_env { tcg_main = Just main_name,
949 tcg_binds = tcg_binds tcg_env
951 tcg_dus = tcg_dus tcg_env
952 `plusDU` usesOnly (unitFV main_name)
953 -- Record the use of 'main', so that we don't
954 -- complain about it being defined but not used
958 mod = tcg_mod tcg_env
959 main_mod = mainModIs dflags
960 main_fn = getMainFun dflags
962 complain_no_main | ghcLink dflags == LinkInMemory = return ()
963 | otherwise = failWithTc noMainMsg
964 -- In interactive mode, don't worry about the absence of 'main'
965 -- In other modes, fail altogether, so that we don't go on
966 -- and complain a second time when processing the export list.
968 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
969 noMainMsg = ptext (sLit "The") <+> pp_main_fn
970 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
971 pp_main_fn = ppMainFn main_fn
974 | main_fn == main_RDR_Unqual
975 = ptext (sLit "function") <+> quotes (ppr main_fn)
977 = ptext (sLit "main function") <+> quotes (ppr main_fn)
979 -- | Get the unqualified name of the function to use as the \"main\" for the main module.
980 -- Either returns the default name or the one configured on the command line with -main-is
981 getMainFun :: DynFlags -> RdrName
982 getMainFun dflags = case (mainFunIs dflags) of
983 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
984 Nothing -> main_RDR_Unqual
986 checkMainExported :: TcGblEnv -> TcM ()
987 checkMainExported tcg_env = do
989 case tcg_main tcg_env of
990 Nothing -> return () -- not the main module
992 let main_mod = mainModIs dflags
993 checkTc (main_name `elem` concatMap availNames (tcg_exports tcg_env)) $
994 ptext (sLit "The") <+> ppMainFn (nameRdrName main_name) <+>
995 ptext (sLit "is not exported by module") <+> quotes (ppr main_mod)
1000 The function that the RTS invokes is always :Main.main, which we call
1001 root_main_id. (Because GHC allows the user to have a module not
1002 called Main as the main module, we can't rely on the main function
1003 being called "Main.main". That's why root_main_id has a fixed module
1006 This is unusual: it's a LocalId whose Name has a Module from another
1007 module. Tiresomely, we must filter it out again in MkIface, les we
1008 get two defns for 'main' in the interface file!
1011 %*********************************************************
1015 %*********************************************************
1019 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
1020 setInteractiveContext hsc_env icxt thing_inside
1021 = let -- Initialise the tcg_inst_env with instances from all home modules.
1022 -- This mimics the more selective call to hptInstances in tcRnModule.
1023 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
1025 updGblEnv (\env -> env {
1026 tcg_rdr_env = ic_rn_gbl_env icxt,
1027 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
1028 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
1032 tcExtendGhciEnv (ic_tmp_ids icxt) $
1033 -- tcExtendGhciEnv does lots:
1034 -- - it extends the local type env (tcl_env) with the given Ids,
1035 -- - it extends the local rdr env (tcl_rdr) with the Names from
1037 -- - it adds the free tyvars of the Ids to the tcl_tyvars
1040 -- later ids in ic_tmp_ids must shadow earlier ones with the same
1041 -- OccName, and tcExtendIdEnv implements this behaviour.
1043 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
1050 -> InteractiveContext
1052 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1053 -- The returned [Id] is the list of new Ids bound by
1054 -- this statement. It can be used to extend the
1055 -- InteractiveContext via extendInteractiveContext.
1057 -- The returned TypecheckedHsExpr is of type IO [ () ],
1058 -- a list of the bound values, coerced to ().
1060 tcRnStmt hsc_env ictxt rdr_stmt
1061 = initTcPrintErrors hsc_env iNTERACTIVE $
1062 setInteractiveContext hsc_env ictxt $ do {
1064 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1065 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
1066 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1068 rnDump (ppr rn_stmt) ;
1070 -- The real work is done here
1071 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1072 zonked_expr <- zonkTopLExpr tc_expr ;
1073 zonked_ids <- zonkTopBndrs bound_ids ;
1075 -- None of the Ids should be of unboxed type, because we
1076 -- cast them all to HValues in the end!
1077 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1079 traceTc (text "tcs 1") ;
1080 let { global_ids = map globaliseAndTidyId zonked_ids } ;
1081 -- Note [Interactively-bound Ids in GHCi]
1083 {- ---------------------------------------------
1084 At one stage I removed any shadowed bindings from the type_env;
1085 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1086 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1088 Prelude> let f n = n * 2 :: Int
1089 Prelude> fName <- runQ [| f |]
1090 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1092 Prelude> let f n = n * 3 :: Int
1093 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1094 In the last line we use 'fName', which resolves to the *first* 'f'
1095 in scope. If we delete it from the type env, GHCi crashes because
1096 it doesn't expect that.
1098 Hence this code is commented out
1100 -------------------------------------------------- -}
1102 dumpOptTcRn Opt_D_dump_tc
1103 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1104 text "Typechecked expr" <+> ppr zonked_expr]) ;
1106 return (global_ids, zonked_expr)
1109 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1110 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1113 Note [Interactively-bound Ids in GHCi]
1114 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1115 The Ids bound by previous Stmts in Template Haskell are currently
1117 b) with an Internal Name (not External)
1118 c) and a tidied type
1120 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1121 compile an expression using these ids later, the byte code
1122 generator will consider the occurrences to be free rather than
1125 (b) They retain their Internal names becuase we don't have a suitable
1126 Module to name them with. We could revisit this choice.
1128 (c) Their types are tidied. This is important, because :info may ask
1129 to look at them, and :info expects the things it looks up to have
1133 --------------------------------------------------------------------------
1134 Typechecking Stmts in GHCi
1136 Here is the grand plan, implemented in tcUserStmt
1138 What you type The IO [HValue] that hscStmt returns
1139 ------------- ------------------------------------
1140 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1143 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1146 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1147 [NB: result not printed] bindings: [it]
1149 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1150 result showable) bindings: [it]
1152 expr (of non-IO type,
1153 result not showable) ==> error
1157 ---------------------------
1158 type PlanResult = ([Id], LHsExpr Id)
1159 type Plan = TcM PlanResult
1161 runPlans :: [Plan] -> TcM PlanResult
1162 -- Try the plans in order. If one fails (by raising an exn), try the next.
1163 -- If one succeeds, take it.
1164 runPlans [] = panic "runPlans"
1166 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1168 --------------------
1169 mkPlan :: LStmt Name -> TcM PlanResult
1170 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1171 = do { uniq <- newUnique -- is treated very specially
1172 ; let fresh_it = itName uniq
1173 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1174 matches = [mkMatch [] expr emptyLocalBinds]
1175 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1176 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1177 (HsVar bindIOName) noSyntaxExpr
1178 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1179 (HsVar thenIOName) placeHolderType
1182 -- [it <- e; print it] but not if it::()
1184 -- [let it = e; print it]
1185 ; runPlans [ -- Plan A
1186 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1187 ; it_ty <- zonkTcType (idType it_id)
1188 ; when (isUnitTy it_ty) failM
1191 -- Plan B; a naked bind statment
1192 tcGhciStmts [bind_stmt],
1194 -- Plan C; check that the let-binding is typeable all by itself.
1195 -- If not, fail; if so, try to print it.
1196 -- The two-step process avoids getting two errors: one from
1197 -- the expression itself, and one from the 'print it' part
1198 -- This two-step story is very clunky, alas
1199 do { checkNoErrs (tcGhciStmts [let_stmt])
1200 --- checkNoErrs defeats the error recovery of let-bindings
1201 ; tcGhciStmts [let_stmt, print_it] }
1204 mkPlan stmt@(L loc (BindStmt {}))
1205 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1206 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1207 (HsVar thenIOName) placeHolderType
1209 ; print_bind_result <- doptM Opt_PrintBindResult
1210 ; let print_plan = do
1211 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1212 ; v_ty <- zonkTcType (idType v_id)
1213 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1217 -- [stmt; print v] but not if v::()
1219 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1220 [tcGhciStmts [stmt]])
1224 = tcGhciStmts [stmt]
1226 ---------------------------
1227 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1229 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1230 ret_id <- tcLookupId returnIOName ; -- return @ IO
1232 ret_ty = mkListTy unitTy ;
1233 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1234 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1236 names = map unLoc (collectLStmtsBinders stmts) ;
1238 -- mk_return builds the expression
1239 -- returnIO @ [()] [coerce () x, .., coerce () z]
1241 -- Despite the inconvenience of building the type applications etc,
1242 -- this *has* to be done in type-annotated post-typecheck form
1243 -- because we are going to return a list of *polymorphic* values
1244 -- coerced to type (). If we built a *source* stmt
1245 -- return [coerce x, ..., coerce z]
1246 -- then the type checker would instantiate x..z, and we wouldn't
1247 -- get their *polymorphic* values. (And we'd get ambiguity errs
1248 -- if they were overloaded, since they aren't applied to anything.)
1249 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1250 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1251 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1255 -- OK, we're ready to typecheck the stmts
1256 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1257 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1258 mapM tcLookupId names ;
1259 -- Look up the names right in the middle,
1260 -- where they will all be in scope
1262 -- Simplify the context
1263 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1264 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1265 -- checkNoErrs ensures that the plan fails if context redn fails
1267 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1268 return (ids, mkHsDictLet const_binds $
1269 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1274 tcRnExpr just finds the type of an expression
1278 -> InteractiveContext
1280 -> IO (Messages, Maybe Type)
1281 tcRnExpr hsc_env ictxt rdr_expr
1282 = initTcPrintErrors hsc_env iNTERACTIVE $
1283 setInteractiveContext hsc_env ictxt $ do {
1285 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1288 -- Now typecheck the expression;
1289 -- it might have a rank-2 type (e.g. :t runST)
1290 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1291 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1292 tcSimplifyInteractive lie_top ;
1294 let { all_expr_ty = mkForAllTys qtvs $
1295 mkFunTys (map (idType . instToId) dict_insts) $
1297 zonkTcType all_expr_ty
1300 smpl_doc = ptext (sLit "main expression")
1303 tcRnType just finds the kind of a type
1307 -> InteractiveContext
1309 -> IO (Messages, Maybe Kind)
1310 tcRnType hsc_env ictxt rdr_type
1311 = initTcPrintErrors hsc_env iNTERACTIVE $
1312 setInteractiveContext hsc_env ictxt $ do {
1314 rn_type <- rnLHsType doc rdr_type ;
1317 -- Now kind-check the type
1318 (ty', kind) <- kcLHsType rn_type ;
1322 doc = ptext (sLit "In GHCi input")
1328 %************************************************************************
1330 More GHCi stuff, to do with browsing and getting info
1332 %************************************************************************
1336 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1337 -- a package module with an interface on disk. If neither of these is
1338 -- true, then the result will be an error indicating the interface
1339 -- could not be found.
1340 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1341 getModuleExports hsc_env mod
1344 checkMods = ic_toplev_scope ic ++ ic_exports ic
1346 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1348 -- Get the export avail info and also load all orphan and family-instance
1349 -- modules. Finally, check that the family instances of all modules in the
1350 -- interactive context are consistent (these modules are in the second
1352 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1353 tcGetModuleExports mod directlyImpMods
1354 = do { let doc = ptext (sLit "context for compiling statements")
1355 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1357 -- Load any orphan-module and family instance-module
1358 -- interfaces, so their instances are visible.
1359 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1360 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1362 -- Check that the family instances of all directly loaded
1363 -- modules are consistent.
1364 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1366 ; ifaceExportNames (mi_exports iface)
1369 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1370 tcRnLookupRdrName hsc_env rdr_name
1371 = initTcPrintErrors hsc_env iNTERACTIVE $
1372 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1373 lookup_rdr_name rdr_name
1375 lookup_rdr_name rdr_name = do {
1376 -- If the identifier is a constructor (begins with an
1377 -- upper-case letter), then we need to consider both
1378 -- constructor and type class identifiers.
1379 let { rdr_names = dataTcOccs rdr_name } ;
1381 -- results :: [Either Messages Name]
1382 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1384 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1385 -- The successful lookups will be (Just name)
1386 let { (warns_s, good_names) = unzip [ (msgs, name)
1387 | (msgs, Just name) <- results] ;
1388 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1390 -- Fail if nothing good happened, else add warnings
1391 if null good_names then
1392 -- No lookup succeeded, so
1393 -- pick the first error message and report it
1394 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1395 -- while the other is "X is not in scope",
1396 -- we definitely want the former; but we might pick the latter
1397 do { addMessages (head errs_s) ; failM }
1398 else -- Add deprecation warnings
1399 mapM_ addMessages warns_s ;
1404 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1405 tcRnLookupName hsc_env name
1406 = initTcPrintErrors hsc_env iNTERACTIVE $
1407 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1408 tcRnLookupName' name
1410 -- To look up a name we have to look in the local environment (tcl_lcl)
1411 -- as well as the global environment, which is what tcLookup does.
1412 -- But we also want a TyThing, so we have to convert:
1414 tcRnLookupName' :: Name -> TcRn TyThing
1415 tcRnLookupName' name = do
1416 tcthing <- tcLookup name
1418 AGlobal thing -> return thing
1419 ATcId{tct_id=id} -> return (AnId id)
1420 _ -> panic "tcRnLookupName'"
1422 tcRnGetInfo :: HscEnv
1424 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1426 -- Used to implement :info in GHCi
1428 -- Look up a RdrName and return all the TyThings it might be
1429 -- A capitalised RdrName is given to us in the DataName namespace,
1430 -- but we want to treat it as *both* a data constructor
1431 -- *and* as a type or class constructor;
1432 -- hence the call to dataTcOccs, and we return up to two results
1433 tcRnGetInfo hsc_env name
1434 = initTcPrintErrors hsc_env iNTERACTIVE $
1435 let ictxt = hsc_IC hsc_env in
1436 setInteractiveContext hsc_env ictxt $ do
1438 -- Load the interface for all unqualified types and classes
1439 -- That way we will find all the instance declarations
1440 -- (Packages have not orphan modules, and we assume that
1441 -- in the home package all relevant modules are loaded.)
1442 loadUnqualIfaces ictxt
1444 thing <- tcRnLookupName' name
1445 fixity <- lookupFixityRn name
1446 ispecs <- lookupInsts thing
1447 return (thing, fixity, ispecs)
1449 lookupInsts :: TyThing -> TcM [Instance]
1450 lookupInsts (AClass cls)
1451 = do { inst_envs <- tcGetInstEnvs
1452 ; return (classInstances inst_envs cls) }
1454 lookupInsts (ATyCon tc)
1455 = do { eps <- getEps -- Load all instances for all classes that are
1456 -- in the type environment (which are all the ones
1457 -- we've seen in any interface file so far)
1458 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1460 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1461 , let dfun = instanceDFunId ispec
1464 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1465 tc_name = tyConName tc
1467 lookupInsts other = return []
1469 loadUnqualIfaces :: InteractiveContext -> TcM ()
1470 -- Load the home module for everything that is in scope unqualified
1471 -- This is so that we can accurately report the instances for
1473 loadUnqualIfaces ictxt
1475 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1477 unqual_mods = [ nameModule name
1478 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1479 let name = gre_name gre,
1480 not (isInternalName name),
1481 isTcOcc (nameOccName name), -- Types and classes only
1482 unQualOK gre ] -- In scope unqualified
1483 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1487 %************************************************************************
1491 %************************************************************************
1494 rnDump :: SDoc -> TcRn ()
1495 -- Dump, with a banner, if -ddump-rn
1496 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1498 tcDump :: TcGblEnv -> TcRn ()
1500 = do { dflags <- getDOpts ;
1502 -- Dump short output if -ddump-types or -ddump-tc
1503 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1504 (dumpTcRn short_dump) ;
1506 -- Dump bindings if -ddump-tc
1507 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1510 short_dump = pprTcGblEnv env
1511 full_dump = pprLHsBinds (tcg_binds env)
1512 -- NB: foreign x-d's have undefined's in their types;
1513 -- hence can't show the tc_fords
1516 = do { dflags <- getDOpts ;
1517 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1518 (dumpTcRn (pprModGuts mod_guts)) ;
1520 -- Dump bindings if -ddump-tc
1521 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1523 full_dump = pprCoreBindings (mg_binds mod_guts)
1525 -- It's unpleasant having both pprModGuts and pprModDetails here
1526 pprTcGblEnv :: TcGblEnv -> SDoc
1527 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1529 tcg_fam_insts = fam_insts,
1531 tcg_imports = imports })
1532 = vcat [ ppr_types insts type_env
1533 , ppr_tycons fam_insts type_env
1535 , ppr_fam_insts fam_insts
1536 , vcat (map ppr rules)
1537 , ppr_gen_tycons (typeEnvTyCons type_env)
1538 , ptext (sLit "Dependent modules:") <+>
1539 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1540 , ptext (sLit "Dependent packages:") <+>
1541 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1542 where -- The two uses of sortBy are just to reduce unnecessary
1543 -- wobbling in testsuite output
1544 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1545 = (mod_name1 `stableModuleNameCmp` mod_name2)
1547 (is_boot1 `compare` is_boot2)
1549 pprModGuts :: ModGuts -> SDoc
1550 pprModGuts (ModGuts { mg_types = type_env,
1552 = vcat [ ppr_types [] type_env,
1555 ppr_types :: [Instance] -> TypeEnv -> SDoc
1556 ppr_types insts type_env
1557 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1559 dfun_ids = map instanceDFunId insts
1560 ids = [id | id <- typeEnvIds type_env, want_sig id]
1561 want_sig id | opt_PprStyle_Debug = True
1562 | otherwise = isLocalId id &&
1563 isExternalName (idName id) &&
1564 not (id `elem` dfun_ids)
1565 -- isLocalId ignores data constructors, records selectors etc.
1566 -- The isExternalName ignores local dictionary and method bindings
1567 -- that the type checker has invented. Top-level user-defined things
1568 -- have External names.
1570 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1571 ppr_tycons fam_insts type_env
1572 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1574 fi_tycons = map famInstTyCon fam_insts
1575 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1576 want_tycon tycon | opt_PprStyle_Debug = True
1577 | otherwise = not (isImplicitTyCon tycon) &&
1578 isExternalName (tyConName tycon) &&
1579 not (tycon `elem` fi_tycons)
1581 ppr_insts :: [Instance] -> SDoc
1582 ppr_insts [] = empty
1583 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1585 ppr_fam_insts :: [FamInst] -> SDoc
1586 ppr_fam_insts [] = empty
1587 ppr_fam_insts fam_insts =
1588 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1590 ppr_sigs :: [Var] -> SDoc
1592 -- Print type signatures; sort by OccName
1593 = vcat (map ppr_sig (sortLe le_sig ids))
1595 le_sig id1 id2 = getOccName id1 <= getOccName id2
1596 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1598 ppr_tydecls :: [TyCon] -> SDoc
1600 -- Print type constructor info; sort by OccName
1601 = vcat (map ppr_tycon (sortLe le_sig tycons))
1603 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1605 | isCoercionTyCon tycon
1606 = sep [ptext (sLit "coercion") <+> ppr tycon <+> ppr tvs
1607 , nest 2 (dcolon <+> pprEqPred (coercionKind (mkTyConApp tycon (mkTyVarTys tvs))))]
1608 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1610 tvs = take (tyConArity tycon) alphaTyVars
1612 ppr_rules :: [CoreRule] -> SDoc
1613 ppr_rules [] = empty
1614 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1615 nest 4 (pprRules rs),
1618 ppr_gen_tycons [] = empty
1619 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1620 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]