2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
5 \section[TcModule]{Typechecking a whole module}
10 tcRnStmt, tcRnExpr, tcRnType,
22 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
51 import TcUnify ( withBox )
76 import Data.List ( sortBy )
87 import TidyPgm ( globaliseAndTidyId )
88 import TcType ( isUnitTy, isTauTy, tyClsNamesOfDFunHead )
89 import TysWiredIn ( unitTy, mkListTy )
99 #include "HsVersions.h"
102 %************************************************************************
104 Typecheck and rename a module
106 %************************************************************************
112 -> Bool -- True <=> save renamed syntax
113 -> Located (HsModule RdrName)
114 -> IO (Messages, Maybe TcGblEnv)
116 tcRnModule hsc_env hsc_src save_rn_syntax
117 (L loc (HsModule maybe_mod export_ies
118 import_decls local_decls mod_deprec
120 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
122 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
123 this_mod = case maybe_mod of
124 Nothing -> mAIN -- 'module M where' is omitted
125 Just (L _ mod) -> mkModule this_pkg mod } ;
128 initTc hsc_env hsc_src save_rn_syntax this_mod $
130 do { -- Deal with imports;
131 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
132 setGblEnv tcg_env $ do {
134 -- Load the hi-boot interface for this module, if any
135 -- We do this now so that the boot_names can be passed
136 -- to tcTyAndClassDecls, because the boot_names are
137 -- automatically considered to be loop breakers
139 -- Do this *after* tcRnImports, so that we know whether
140 -- a module that we import imports us; and hence whether to
141 -- look for a hi-boot file
142 boot_iface <- tcHiBootIface hsc_src this_mod ;
144 -- Rename and type check the declarations
145 traceRn (text "rn1a") ;
146 tcg_env <- if isHsBoot hsc_src then
147 tcRnHsBootDecls local_decls
149 tcRnSrcDecls boot_iface local_decls ;
150 setGblEnv tcg_env $ do {
152 -- Report the use of any deprecated things
153 -- We do this *before* processsing the export list so
154 -- that we don't bleat about re-exporting a deprecated
155 -- thing (especially via 'module Foo' export item)
156 -- That is, only uses in the *body* of the module are complained about
157 traceRn (text "rn3") ;
158 failIfErrsM ; -- finishWarnings crashes sometimes
159 -- as a result of typechecker repairs (e.g. unboundNames)
160 tcg_env <- finishWarnings (hsc_dflags hsc_env) mod_deprec tcg_env ;
162 -- Process the export list
163 traceRn (text "rn4a: before exports");
164 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
165 traceRn (text "rn4b: after exportss") ;
167 -- Check that main is exported (must be after rnExports)
168 checkMainExported tcg_env ;
170 -- Compare the hi-boot iface (if any) with the real thing
171 -- Must be done after processing the exports
172 tcg_env <- checkHiBootIface tcg_env boot_iface ;
174 -- The new type env is already available to stuff slurped from
175 -- interface files, via TcEnv.updateGlobalTypeEnv
176 -- It's important that this includes the stuff in checkHiBootIface,
177 -- because the latter might add new bindings for boot_dfuns,
178 -- which may be mentioned in imported unfoldings
180 -- Don't need to rename the Haddock documentation,
181 -- it's not parsed by GHC anymore.
182 tcg_env <- return (tcg_env { tcg_doc_hdr = maybe_doc_hdr }) ;
184 -- Report unused names
185 reportUnusedNames export_ies tcg_env ;
187 -- Dump output and return
194 %************************************************************************
198 %************************************************************************
201 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
202 tcRnImports hsc_env this_mod import_decls
203 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
205 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
206 ; dep_mods = imp_dep_mods imports
208 -- We want instance declarations from all home-package
209 -- modules below this one, including boot modules, except
210 -- ourselves. The 'except ourselves' is so that we don't
211 -- get the instances from this module's hs-boot file
212 ; want_instances :: ModuleName -> Bool
213 ; want_instances mod = mod `elemUFM` dep_mods
214 && mod /= moduleName this_mod
215 ; (home_insts, home_fam_insts) = hptInstances hsc_env
219 -- Record boot-file info in the EPS, so that it's
220 -- visible to loadHiBootInterface in tcRnSrcDecls,
221 -- and any other incrementally-performed imports
222 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
224 -- Update the gbl env
225 ; updGblEnv ( \ gbl ->
227 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
228 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
229 tcg_rn_imports = rn_imports,
230 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
231 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
236 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
237 -- Fail if there are any errors so far
238 -- The error printing (if needed) takes advantage
239 -- of the tcg_env we have now set
240 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
243 -- Load any orphan-module and family instance-module
244 -- interfaces, so that their rules and instance decls will be
246 ; loadOrphanModules (imp_orphs imports) False
247 ; loadOrphanModules (imp_finsts imports) True
249 -- Check type-familily consistency
250 ; traceRn (text "rn1: checking family instance consistency")
251 ; let { dir_imp_mods = moduleEnvKeys
254 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
260 %************************************************************************
262 Type-checking external-core modules
264 %************************************************************************
267 tcRnExtCore :: HscEnv
269 -> IO (Messages, Maybe ModGuts)
270 -- Nothing => some error occurred
272 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
273 -- The decls are IfaceDecls; all names are original names
274 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
276 initTc hsc_env ExtCoreFile False this_mod $ do {
278 let { ldecls = map noLoc decls } ;
280 -- bring the type and class decls into scope
281 -- ToDo: check that this doesn't need to extract the val binds.
282 -- It seems that only the type and class decls need to be in scope below because
283 -- (a) tcTyAndClassDecls doesn't need the val binds, and
284 -- (b) tcExtCoreBindings doesn't need anything
285 -- (in fact, it might not even need to be in the scope of
286 -- this tcg_env at all)
287 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
288 tc_envs <- extendGlobalRdrEnvRn avails emptyFsEnv {- no fixity decls -} ;
290 setEnvs tc_envs $ do {
292 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
294 -- Dump trace of renaming part
295 rnDump (ppr rn_decls) ;
297 -- Typecheck them all together so that
298 -- any mutually recursive types are done right
299 -- Just discard the auxiliary bindings; they are generated
300 -- only for Haskell source code, and should already be in Core
301 (tcg_env, _aux_binds) <- tcTyAndClassDecls emptyModDetails rn_decls ;
303 setGblEnv tcg_env $ do {
304 -- Make the new type env available to stuff slurped from interface files
306 -- Now the core bindings
307 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
311 bndrs = bindersOfBinds core_binds ;
312 my_exports = map (Avail . idName) bndrs ;
313 -- ToDo: export the data types also?
316 extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
318 mod_guts = ModGuts { mg_module = this_mod,
320 mg_used_names = emptyNameSet, -- ToDo: compute usage
321 mg_dir_imps = emptyModuleEnv, -- ??
322 mg_deps = noDependencies, -- ??
323 mg_exports = my_exports,
324 mg_types = final_type_env,
325 mg_insts = tcg_insts tcg_env,
326 mg_fam_insts = tcg_fam_insts tcg_env,
327 mg_inst_env = tcg_inst_env tcg_env,
328 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
331 mg_binds = core_binds,
334 mg_rdr_env = emptyGlobalRdrEnv,
335 mg_fix_env = emptyFixityEnv,
336 mg_warns = NoWarnings,
337 mg_foreign = NoStubs,
338 mg_hpc_info = emptyHpcInfo False,
339 mg_modBreaks = emptyModBreaks,
340 mg_vect_info = noVectInfo
343 tcCoreDump mod_guts ;
348 mkFakeGroup :: [LTyClDecl a] -> HsGroup a
349 mkFakeGroup decls -- Rather clumsy; lots of unused fields
350 = emptyRdrGroup { hs_tyclds = decls }
354 %************************************************************************
356 Type-checking the top level of a module
358 %************************************************************************
361 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
362 -- Returns the variables free in the decls
363 -- Reason: solely to report unused imports and bindings
364 tcRnSrcDecls boot_iface decls
365 = do { -- Do all the declarations
366 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
368 -- Finish simplifying class constraints
370 -- tcSimplifyTop deals with constant or ambiguous InstIds.
371 -- How could there be ambiguous ones? They can only arise if a
372 -- top-level decl falls under the monomorphism restriction
373 -- and no subsequent decl instantiates its type.
375 -- We do this after checkMain, so that we use the type info
376 -- thaat checkMain adds
378 -- We do it with both global and local env in scope:
379 -- * the global env exposes the instances to tcSimplifyTop
380 -- * the local env exposes the local Ids to tcSimplifyTop,
381 -- so that we get better error messages (monomorphism restriction)
382 traceTc (text "Tc8") ;
383 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
385 -- Backsubstitution. This must be done last.
386 -- Even tcSimplifyTop may do some unification.
387 traceTc (text "Tc9") ;
388 let { (tcg_env, _) = tc_envs
389 ; TcGblEnv { tcg_type_env = type_env,
392 tcg_fords = fords } = tcg_env
393 ; all_binds = binds `unionBags` inst_binds } ;
395 failIfErrsM ; -- Don't zonk if there have been errors
396 -- It's a waste of time; and we may get debug warnings
397 -- about strangely-typed TyCons!
399 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
402 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
403 ; tcg_env' = tcg_env { tcg_binds = binds',
405 tcg_fords = fords' } } ;
407 setGlobalTypeEnv tcg_env' final_type_env
410 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
411 -- Loops around dealing with each top level inter-splice group
412 -- in turn, until it's dealt with the entire module
413 tc_rn_src_decls boot_details ds
414 = do { let { (first_group, group_tail) = findSplice ds } ;
415 -- If ds is [] we get ([], Nothing)
417 -- Deal with decls up to, but not including, the first splice
418 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
419 -- rnTopSrcDecls fails if there are any errors
421 (tcg_env, tcl_env) <- setGblEnv tcg_env $
422 tcTopSrcDecls boot_details rn_decls ;
424 -- If there is no splice, we're nearly done
425 setEnvs (tcg_env, tcl_env) $
427 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
428 return (tcg_env, tcl_env)
432 -- There shouldn't be a splice
433 Just (SpliceDecl {}, _) -> do {
434 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
436 -- If there's a splice, we must carry on
437 Just (SpliceDecl splice_expr, rest_ds) -> do {
439 -- Rename the splice expression, and get its supporting decls
440 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
441 -- checkNoErrs: don't typecheck if renaming failed
442 rnDump (ppr rn_splice_expr) ;
444 -- Execute the splice
445 spliced_decls <- tcSpliceDecls rn_splice_expr ;
447 -- Glue them on the front of the remaining decls and loop
448 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
449 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
454 %************************************************************************
456 Compiling hs-boot source files, and
457 comparing the hi-boot interface with the real thing
459 %************************************************************************
462 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
463 tcRnHsBootDecls decls
464 = do { let { (first_group, group_tail) = findSplice decls }
466 -- Rename the declarations
467 ; (tcg_env, HsGroup {
468 hs_tyclds = tycl_decls,
469 hs_instds = inst_decls,
470 hs_derivds = deriv_decls,
471 hs_fords = for_decls,
472 hs_defds = def_decls,
473 hs_ruleds = rule_decls,
475 hs_valds = val_binds }) <- rnTopSrcDecls first_group
476 ; setGblEnv tcg_env $ do {
479 -- Check for illegal declarations
481 Just (SpliceDecl d, _) -> badBootDecl "splice" d
483 ; mapM_ (badBootDecl "foreign") for_decls
484 ; mapM_ (badBootDecl "default") def_decls
485 ; mapM_ (badBootDecl "rule") rule_decls
487 -- Typecheck type/class decls
488 ; traceTc (text "Tc2")
489 ; (tcg_env, aux_binds) <- tcTyAndClassDecls emptyModDetails tycl_decls
490 ; setGblEnv tcg_env $ do {
492 -- Typecheck instance decls
493 -- Family instance declarations are rejected here
494 ; traceTc (text "Tc3")
495 ; (tcg_env, inst_infos, _deriv_binds)
496 <- tcInstDecls1 tycl_decls inst_decls deriv_decls
497 ; setGblEnv tcg_env $ do {
499 -- Typecheck value declarations
500 ; traceTc (text "Tc5")
501 ; val_ids <- tcHsBootSigs val_binds
504 -- No simplification or zonking to do
505 ; traceTc (text "Tc7a")
506 ; gbl_env <- getGblEnv
508 -- Make the final type-env
509 -- Include the dfun_ids so that their type sigs
510 -- are written into the interface file.
511 -- And similarly the aux_ids from aux_binds
512 ; let { type_env0 = tcg_type_env gbl_env
513 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
514 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
515 ; type_env3 = extendTypeEnvWithIds type_env2 aux_ids
516 ; dfun_ids = map iDFunId inst_infos
517 ; aux_ids = case aux_binds of
518 ValBindsOut _ sigs -> [id | L _ (IdSig id) <- sigs]
519 _ -> panic "tcRnHsBoodDecls"
522 ; setGlobalTypeEnv gbl_env type_env3
525 badBootDecl :: String -> Located decl -> TcM ()
526 badBootDecl what (L loc _)
527 = addErrAt loc (char 'A' <+> text what
528 <+> ptext (sLit "declaration is not (currently) allowed in a hs-boot file"))
531 Once we've typechecked the body of the module, we want to compare what
532 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
535 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
536 -- Compare the hi-boot file for this module (if there is one)
537 -- with the type environment we've just come up with
538 -- In the common case where there is no hi-boot file, the list
539 -- of boot_names is empty.
541 -- The bindings we return give bindings for the dfuns defined in the
542 -- hs-boot file, such as $fbEqT = $fEqT
545 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
546 tcg_insts = local_insts,
547 tcg_type_env = local_type_env, tcg_exports = local_exports })
548 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
549 md_types = boot_type_env, md_exports = boot_exports })
550 | isHsBoot hs_src -- Current module is already a hs-boot file!
554 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
557 -- Check the exports of the boot module, one by one
558 ; mapM_ check_export boot_exports
560 -- Check for no family instances
561 ; unless (null boot_fam_insts) $
562 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
563 "instances in boot files yet...")
564 -- FIXME: Why? The actual comparison is not hard, but what would
565 -- be the equivalent to the dfun bindings returned for class
566 -- instances? We can't easily equate tycons...
568 -- Check instance declarations
569 ; mb_dfun_prs <- mapM check_inst boot_insts
570 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds,
571 tcg_type_env = extendTypeEnvWithIds local_type_env boot_dfuns }
572 dfun_prs = catMaybes mb_dfun_prs
573 boot_dfuns = map fst dfun_prs
574 dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun)
575 | (boot_dfun, dfun) <- dfun_prs ]
580 check_export boot_avail -- boot_avail is exported by the boot iface
581 | name `elem` dfun_names = return ()
582 | isWiredInName name = return () -- No checking for wired-in names. In particular,
583 -- 'error' is handled by a rather gross hack
584 -- (see comments in GHC.Err.hs-boot)
586 -- Check that the actual module exports the same thing
587 | not (null missing_names)
588 = addErrAt (nameSrcSpan (head missing_names))
589 (missingBootThing (head missing_names) "exported by")
591 -- If the boot module does not *define* the thing, we are done
592 -- (it simply re-exports it, and names match, so nothing further to do)
593 | isNothing mb_boot_thing = return ()
595 -- Check that the actual module also defines the thing, and
596 -- then compare the definitions
597 | Just real_thing <- lookupTypeEnv local_type_env name,
598 Just boot_thing <- mb_boot_thing
599 = when (not (checkBootDecl boot_thing real_thing))
600 $ addErrAt (nameSrcSpan (getName boot_thing))
601 (let boot_decl = tyThingToIfaceDecl
602 (fromJust mb_boot_thing)
603 real_decl = tyThingToIfaceDecl real_thing
604 in bootMisMatch real_thing boot_decl real_decl)
607 = addErrTc (missingBootThing name "defined in")
609 name = availName boot_avail
610 mb_boot_thing = lookupTypeEnv boot_type_env name
611 missing_names = case lookupNameEnv local_export_env name of
613 Just avail -> availNames boot_avail `minusList` availNames avail
615 dfun_names = map getName boot_insts
617 local_export_env :: NameEnv AvailInfo
618 local_export_env = availsToNameEnv local_exports
620 check_inst :: Instance -> TcM (Maybe (Id, Id))
621 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
623 = case [dfun | inst <- local_insts,
624 let dfun = instanceDFunId inst,
625 idType dfun `tcEqType` boot_inst_ty ] of
626 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
627 (dfun:_) -> return (Just (local_boot_dfun, dfun))
629 boot_dfun = instanceDFunId boot_inst
630 boot_inst_ty = idType boot_dfun
631 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
634 -- This has to compare the TyThing from the .hi-boot file to the TyThing
635 -- in the current source file. We must be careful to allow alpha-renaming
636 -- where appropriate, and also the boot declaration is allowed to omit
637 -- constructors and class methods.
639 -- See rnfail055 for a good test of this stuff.
641 checkBootDecl :: TyThing -> TyThing -> Bool
643 checkBootDecl (AnId id1) (AnId id2)
645 (idType id1 `tcEqType` idType id2)
647 checkBootDecl (ATyCon tc1) (ATyCon tc2)
648 = checkBootTyCon tc1 tc2
650 checkBootDecl (AClass c1) (AClass c2)
652 (clas_tyvars1, clas_fds1, sc_theta1, _, ats1, op_stuff1)
653 = classExtraBigSig c1
654 (clas_tyvars2, clas_fds2, sc_theta2, _, ats2, op_stuff2)
655 = classExtraBigSig c2
657 env0 = mkRnEnv2 emptyInScopeSet
658 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
660 eqSig (id1, def_meth1) (id2, def_meth2)
661 = idName id1 == idName id2 &&
662 tcEqTypeX env op_ty1 op_ty2 &&
663 def_meth1 == def_meth2
665 (_, rho_ty1) = splitForAllTys (idType id1)
666 op_ty1 = funResultTy rho_ty1
667 (_, rho_ty2) = splitForAllTys (idType id2)
668 op_ty2 = funResultTy rho_ty2
670 eqFD (as1,bs1) (as2,bs2) =
671 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
672 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
674 same_kind tv1 tv2 = eqKind (tyVarKind tv1) (tyVarKind tv2)
676 eqListBy same_kind clas_tyvars1 clas_tyvars2 &&
677 -- Checks kind of class
678 eqListBy eqFD clas_fds1 clas_fds2 &&
679 (null sc_theta1 && null op_stuff1 && null ats1
680 || -- Above tests for an "abstract" class
681 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
682 eqListBy eqSig op_stuff1 op_stuff2 &&
683 eqListBy checkBootTyCon ats1 ats2)
685 checkBootDecl (ADataCon dc1) (ADataCon _)
686 = pprPanic "checkBootDecl" (ppr dc1)
688 checkBootDecl _ _ = False -- probably shouldn't happen
691 checkBootTyCon :: TyCon -> TyCon -> Bool
692 checkBootTyCon tc1 tc2
693 | not (eqKind (tyConKind tc1) (tyConKind tc2))
694 = False -- First off, check the kind
696 | isSynTyCon tc1 && isSynTyCon tc2
698 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
699 env = rnBndrs2 env0 tvs1 tvs2
701 eqSynRhs (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
702 = tcEqTypeX env k1 k2
703 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
704 = tcEqTypeX env t1 t2
707 equalLength tvs1 tvs2 &&
708 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
710 | isAlgTyCon tc1 && isAlgTyCon tc2
712 eqKind (tyConKind tc1) (tyConKind tc2) &&
713 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2) &&
714 eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
716 | isForeignTyCon tc1 && isForeignTyCon tc2
717 = eqKind (tyConKind tc1) (tyConKind tc2) &&
718 tyConExtName tc1 == tyConExtName tc2
722 env0 = mkRnEnv2 emptyInScopeSet
724 eqAlgRhs AbstractTyCon _ = True
725 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
726 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
727 eqListBy eqCon (data_cons tc1) (data_cons tc2)
728 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
729 eqCon (data_con tc1) (data_con tc2)
733 = dataConName c1 == dataConName c2
734 && dataConIsInfix c1 == dataConIsInfix c2
735 && dataConStrictMarks c1 == dataConStrictMarks c2
736 && dataConFieldLabels c1 == dataConFieldLabels c2
737 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
738 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
739 env = rnBndrs2 env0 tvs1 tvs2
741 equalLength tvs1 tvs2 &&
742 eqListBy (tcEqPredX env)
743 (dataConEqTheta c1 ++ dataConDictTheta c1)
744 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
745 eqListBy (tcEqTypeX env)
746 (dataConOrigArgTys c1)
747 (dataConOrigArgTys c2)
750 missingBootThing :: Name -> String -> SDoc
751 missingBootThing name what
752 = ppr name <+> ptext (sLit "is exported by the hs-boot file, but not")
753 <+> text what <+> ptext (sLit "the module")
755 bootMisMatch :: TyThing -> IfaceDecl -> IfaceDecl -> SDoc
756 bootMisMatch thing boot_decl real_decl
757 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
758 ptext (sLit "Main module:") <+> ppr real_decl,
759 ptext (sLit "Boot file: ") <+> ppr boot_decl]
761 instMisMatch :: Instance -> SDoc
764 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
768 %************************************************************************
770 Type-checking the top level of a module
772 %************************************************************************
774 tcRnGroup takes a bunch of top-level source-code declarations, and
776 * gets supporting declarations from interface files
779 * and augments the TcGblEnv with the results
781 In Template Haskell it may be called repeatedly for each group of
782 declarations. It expects there to be an incoming TcGblEnv in the
783 monad; it augments it and returns the new TcGblEnv.
786 ------------------------------------------------
787 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
788 -- Fails if there are any errors
790 = do { -- Rename the source decls
791 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
793 -- save the renamed syntax, if we want it
795 | Just grp <- tcg_rn_decls tcg_env
796 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
800 -- Dump trace of renaming part
801 rnDump (ppr rn_decls) ;
803 return (tcg_env', rn_decls)
806 ------------------------------------------------
807 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
808 tcTopSrcDecls boot_details
809 (HsGroup { hs_tyclds = tycl_decls,
810 hs_instds = inst_decls,
811 hs_derivds = deriv_decls,
812 hs_fords = foreign_decls,
813 hs_defds = default_decls,
814 hs_annds = annotation_decls,
815 hs_ruleds = rule_decls,
816 hs_valds = val_binds })
817 = do { -- Type-check the type and class decls, and all imported decls
818 -- The latter come in via tycl_decls
819 traceTc (text "Tc2") ;
821 (tcg_env, aux_binds) <- tcTyAndClassDecls boot_details tycl_decls ;
822 -- If there are any errors, tcTyAndClassDecls fails here
824 setGblEnv tcg_env $ do {
825 -- Source-language instances, including derivings,
826 -- and import the supporting declarations
827 traceTc (text "Tc3") ;
828 (tcg_env, inst_infos, deriv_binds)
829 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
830 setGblEnv tcg_env $ do {
832 -- Foreign import declarations next.
833 traceTc (text "Tc4") ;
834 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
835 tcExtendGlobalValEnv fi_ids $ do {
837 -- Default declarations
838 traceTc (text "Tc4a") ;
839 default_tys <- tcDefaults default_decls ;
840 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
842 -- Now GHC-generated derived bindings, generics, and selectors
843 -- Do not generate warnings from compiler-generated code;
844 -- hence the use of discardWarnings
845 (tc_aux_binds, tcl_env) <- discardWarnings (tcTopBinds aux_binds) ;
846 (tc_deriv_binds, tcl_env) <- setLclTypeEnv tcl_env $
847 discardWarnings (tcTopBinds deriv_binds) ;
849 -- Value declarations next
850 traceTc (text "Tc5") ;
851 (tc_val_binds, tcl_env) <- setLclTypeEnv tcl_env $
852 tcTopBinds val_binds;
854 -- Second pass over class and instance declarations,
855 traceTc (text "Tc6") ;
856 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $
857 tcInstDecls2 tycl_decls inst_infos ;
858 showLIE (text "after instDecls2") ;
860 setLclTypeEnv tcl_env $ do { -- Environment doesn't change now
863 traceTc (text "Tc7") ;
864 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
867 annotations <- tcAnnotations annotation_decls ;
870 rules <- tcRules rule_decls ;
873 traceTc (text "Tc7a") ;
874 tcg_env <- getGblEnv ;
875 let { all_binds = tc_val_binds `unionBags`
876 tc_deriv_binds `unionBags`
877 tc_aux_binds `unionBags`
878 inst_binds `unionBags`
881 -- Extend the GblEnv with the (as yet un-zonked)
882 -- bindings, rules, foreign decls
883 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
884 tcg_rules = tcg_rules tcg_env ++ rules,
885 tcg_anns = tcg_anns tcg_env ++ annotations,
886 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
887 return (tcg_env', tcl_env)
892 %************************************************************************
896 %************************************************************************
899 checkMain :: TcM TcGblEnv
900 -- If we are in module Main, check that 'main' is defined.
902 = do { tcg_env <- getGblEnv ;
904 check_main dflags tcg_env
907 check_main :: DynFlags -> TcGblEnv -> TcM TcGblEnv
908 check_main dflags tcg_env
910 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
914 = do { mb_main <- lookupGlobalOccRn_maybe main_fn
915 -- Check that 'main' is in scope
916 -- It might be imported from another module!
918 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
923 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
924 ; let loc = srcLocSpan (getSrcLoc main_name)
925 ; ioTyCon <- tcLookupTyCon ioTyConName
926 ; (main_expr, res_ty)
927 <- addErrCtxt mainCtxt $
928 withBox liftedTypeKind $ \res_ty ->
929 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
931 -- See Note [Root-main Id]
932 -- Construct the binding
933 -- :Main.main :: IO res_ty = runMainIO res_ty main
934 ; run_main_id <- tcLookupId runMainIOName
935 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
936 (mkVarOccFS (fsLit "main"))
937 (getSrcSpan main_name)
938 ; root_main_id = Id.mkExportedLocalId root_main_name
939 (mkTyConApp ioTyCon [res_ty])
940 ; co = mkWpTyApps [res_ty]
941 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
942 ; main_bind = mkVarBind root_main_id rhs }
944 ; return (tcg_env { tcg_main = Just main_name,
945 tcg_binds = tcg_binds tcg_env
947 tcg_dus = tcg_dus tcg_env
948 `plusDU` usesOnly (unitFV main_name)
949 -- Record the use of 'main', so that we don't
950 -- complain about it being defined but not used
954 mod = tcg_mod tcg_env
955 main_mod = mainModIs dflags
956 main_fn = getMainFun dflags
958 complain_no_main | ghcLink dflags == LinkInMemory = return ()
959 | otherwise = failWithTc noMainMsg
960 -- In interactive mode, don't worry about the absence of 'main'
961 -- In other modes, fail altogether, so that we don't go on
962 -- and complain a second time when processing the export list.
964 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
965 noMainMsg = ptext (sLit "The") <+> pp_main_fn
966 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
967 pp_main_fn = ppMainFn main_fn
969 ppMainFn :: RdrName -> SDoc
971 | main_fn == main_RDR_Unqual
972 = ptext (sLit "function") <+> quotes (ppr main_fn)
974 = ptext (sLit "main function") <+> quotes (ppr main_fn)
976 -- | Get the unqualified name of the function to use as the \"main\" for the main module.
977 -- Either returns the default name or the one configured on the command line with -main-is
978 getMainFun :: DynFlags -> RdrName
979 getMainFun dflags = case (mainFunIs dflags) of
980 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
981 Nothing -> main_RDR_Unqual
983 checkMainExported :: TcGblEnv -> TcM ()
984 checkMainExported tcg_env = do
986 case tcg_main tcg_env of
987 Nothing -> return () -- not the main module
989 let main_mod = mainModIs dflags
990 checkTc (main_name `elem` concatMap availNames (tcg_exports tcg_env)) $
991 ptext (sLit "The") <+> ppMainFn (nameRdrName main_name) <+>
992 ptext (sLit "is not exported by module") <+> quotes (ppr main_mod)
997 The function that the RTS invokes is always :Main.main, which we call
998 root_main_id. (Because GHC allows the user to have a module not
999 called Main as the main module, we can't rely on the main function
1000 being called "Main.main". That's why root_main_id has a fixed module
1003 This is unusual: it's a LocalId whose Name has a Module from another
1004 module. Tiresomely, we must filter it out again in MkIface, les we
1005 get two defns for 'main' in the interface file!
1008 %*********************************************************
1012 %*********************************************************
1016 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
1017 setInteractiveContext hsc_env icxt thing_inside
1018 = let -- Initialise the tcg_inst_env with instances from all home modules.
1019 -- This mimics the more selective call to hptInstances in tcRnModule.
1020 (home_insts, home_fam_insts) = hptInstances hsc_env (\_ -> True)
1022 updGblEnv (\env -> env {
1023 tcg_rdr_env = ic_rn_gbl_env icxt,
1024 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
1025 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
1029 tcExtendGhciEnv (ic_tmp_ids icxt) $
1030 -- tcExtendGhciEnv does lots:
1031 -- - it extends the local type env (tcl_env) with the given Ids,
1032 -- - it extends the local rdr env (tcl_rdr) with the Names from
1034 -- - it adds the free tyvars of the Ids to the tcl_tyvars
1037 -- later ids in ic_tmp_ids must shadow earlier ones with the same
1038 -- OccName, and tcExtendIdEnv implements this behaviour.
1040 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
1047 -> InteractiveContext
1049 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1050 -- The returned [Id] is the list of new Ids bound by
1051 -- this statement. It can be used to extend the
1052 -- InteractiveContext via extendInteractiveContext.
1054 -- The returned TypecheckedHsExpr is of type IO [ () ],
1055 -- a list of the bound values, coerced to ().
1057 tcRnStmt hsc_env ictxt rdr_stmt
1058 = initTcPrintErrors hsc_env iNTERACTIVE $
1059 setInteractiveContext hsc_env ictxt $ do {
1061 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1062 (([rn_stmt], _), fvs) <- rnStmts GhciStmt [rdr_stmt] (return ((), emptyFVs)) ;
1063 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1065 rnDump (ppr rn_stmt) ;
1067 -- The real work is done here
1068 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1069 zonked_expr <- zonkTopLExpr tc_expr ;
1070 zonked_ids <- zonkTopBndrs bound_ids ;
1072 -- None of the Ids should be of unboxed type, because we
1073 -- cast them all to HValues in the end!
1074 mapM_ bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1076 traceTc (text "tcs 1") ;
1077 let { global_ids = map globaliseAndTidyId zonked_ids } ;
1078 -- Note [Interactively-bound Ids in GHCi]
1080 {- ---------------------------------------------
1081 At one stage I removed any shadowed bindings from the type_env;
1082 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1083 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1085 Prelude> let f n = n * 2 :: Int
1086 Prelude> fName <- runQ [| f |]
1087 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1089 Prelude> let f n = n * 3 :: Int
1090 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1091 In the last line we use 'fName', which resolves to the *first* 'f'
1092 in scope. If we delete it from the type env, GHCi crashes because
1093 it doesn't expect that.
1095 Hence this code is commented out
1097 -------------------------------------------------- -}
1099 dumpOptTcRn Opt_D_dump_tc
1100 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1101 text "Typechecked expr" <+> ppr zonked_expr]) ;
1103 return (global_ids, zonked_expr)
1106 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1107 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1110 Note [Interactively-bound Ids in GHCi]
1111 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1112 The Ids bound by previous Stmts in Template Haskell are currently
1114 b) with an Internal Name (not External)
1115 c) and a tidied type
1117 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1118 compile an expression using these ids later, the byte code
1119 generator will consider the occurrences to be free rather than
1122 (b) They retain their Internal names becuase we don't have a suitable
1123 Module to name them with. We could revisit this choice.
1125 (c) Their types are tidied. This is important, because :info may ask
1126 to look at them, and :info expects the things it looks up to have
1130 --------------------------------------------------------------------------
1131 Typechecking Stmts in GHCi
1133 Here is the grand plan, implemented in tcUserStmt
1135 What you type The IO [HValue] that hscStmt returns
1136 ------------- ------------------------------------
1137 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1140 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1143 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1144 [NB: result not printed] bindings: [it]
1146 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1147 result showable) bindings: [it]
1149 expr (of non-IO type,
1150 result not showable) ==> error
1154 ---------------------------
1155 type PlanResult = ([Id], LHsExpr Id)
1156 type Plan = TcM PlanResult
1158 runPlans :: [Plan] -> TcM PlanResult
1159 -- Try the plans in order. If one fails (by raising an exn), try the next.
1160 -- If one succeeds, take it.
1161 runPlans [] = panic "runPlans"
1163 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1165 --------------------
1166 mkPlan :: LStmt Name -> TcM PlanResult
1167 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1168 = do { uniq <- newUnique -- is treated very specially
1169 ; let fresh_it = itName uniq
1170 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1171 matches = [mkMatch [] expr emptyLocalBinds]
1172 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1173 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1174 (HsVar bindIOName) noSyntaxExpr
1175 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1176 (HsVar thenIOName) placeHolderType
1179 -- [it <- e; print it] but not if it::()
1181 -- [let it = e; print it]
1182 ; runPlans [ -- Plan A
1183 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1184 ; it_ty <- zonkTcType (idType it_id)
1185 ; when (isUnitTy it_ty) failM
1188 -- Plan B; a naked bind statment
1189 tcGhciStmts [bind_stmt],
1191 -- Plan C; check that the let-binding is typeable all by itself.
1192 -- If not, fail; if so, try to print it.
1193 -- The two-step process avoids getting two errors: one from
1194 -- the expression itself, and one from the 'print it' part
1195 -- This two-step story is very clunky, alas
1196 do { _ <- checkNoErrs (tcGhciStmts [let_stmt])
1197 --- checkNoErrs defeats the error recovery of let-bindings
1198 ; tcGhciStmts [let_stmt, print_it] }
1201 mkPlan stmt@(L loc (BindStmt {}))
1202 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1203 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1204 (HsVar thenIOName) placeHolderType
1206 ; print_bind_result <- doptM Opt_PrintBindResult
1207 ; let print_plan = do
1208 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1209 ; v_ty <- zonkTcType (idType v_id)
1210 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1214 -- [stmt; print v] but not if v::()
1216 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1217 [tcGhciStmts [stmt]])
1221 = tcGhciStmts [stmt]
1223 ---------------------------
1224 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1226 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1227 ret_id <- tcLookupId returnIOName ; -- return @ IO
1229 ret_ty = mkListTy unitTy ;
1230 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1231 tc_io_stmts stmts = tcStmts GhciStmt tcDoStmt stmts io_ret_ty ;
1233 names = map unLoc (collectLStmtsBinders stmts) ;
1235 -- mk_return builds the expression
1236 -- returnIO @ [()] [coerce () x, .., coerce () z]
1238 -- Despite the inconvenience of building the type applications etc,
1239 -- this *has* to be done in type-annotated post-typecheck form
1240 -- because we are going to return a list of *polymorphic* values
1241 -- coerced to type (). If we built a *source* stmt
1242 -- return [coerce x, ..., coerce z]
1243 -- then the type checker would instantiate x..z, and we wouldn't
1244 -- get their *polymorphic* values. (And we'd get ambiguity errs
1245 -- if they were overloaded, since they aren't applied to anything.)
1246 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1247 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1248 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1252 -- OK, we're ready to typecheck the stmts
1253 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1254 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1255 mapM tcLookupId names ;
1256 -- Look up the names right in the middle,
1257 -- where they will all be in scope
1259 -- Simplify the context
1260 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1261 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1262 -- checkNoErrs ensures that the plan fails if context redn fails
1264 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1265 return (ids, mkHsDictLet const_binds $
1266 noLoc (HsDo GhciStmt tc_stmts (mk_return ids) io_ret_ty))
1271 tcRnExpr just finds the type of an expression
1275 -> InteractiveContext
1277 -> IO (Messages, Maybe Type)
1278 tcRnExpr hsc_env ictxt rdr_expr
1279 = initTcPrintErrors hsc_env iNTERACTIVE $
1280 setInteractiveContext hsc_env ictxt $ do {
1282 (rn_expr, _fvs) <- rnLExpr rdr_expr ;
1285 -- Now typecheck the expression;
1286 -- it might have a rank-2 type (e.g. :t runST)
1287 ((_tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1288 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1289 _ <- tcSimplifyInteractive lie_top ; -- Ignore the dicionary bindings
1291 let { all_expr_ty = mkForAllTys qtvs $
1292 mkFunTys (map (idType . instToId) dict_insts) $
1294 zonkTcType all_expr_ty
1297 smpl_doc = ptext (sLit "main expression")
1300 tcRnType just finds the kind of a type
1304 -> InteractiveContext
1306 -> IO (Messages, Maybe Kind)
1307 tcRnType hsc_env ictxt rdr_type
1308 = initTcPrintErrors hsc_env iNTERACTIVE $
1309 setInteractiveContext hsc_env ictxt $ do {
1311 rn_type <- rnLHsType doc rdr_type ;
1314 -- Now kind-check the type
1315 (_ty', kind) <- kcLHsType rn_type ;
1319 doc = ptext (sLit "In GHCi input")
1325 %************************************************************************
1327 More GHCi stuff, to do with browsing and getting info
1329 %************************************************************************
1333 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1334 -- a package module with an interface on disk. If neither of these is
1335 -- true, then the result will be an error indicating the interface
1336 -- could not be found.
1337 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1338 getModuleExports hsc_env mod
1341 checkMods = ic_toplev_scope ic ++ ic_exports ic
1343 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1345 -- Get the export avail info and also load all orphan and family-instance
1346 -- modules. Finally, check that the family instances of all modules in the
1347 -- interactive context are consistent (these modules are in the second
1349 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1350 tcGetModuleExports mod directlyImpMods
1351 = do { let doc = ptext (sLit "context for compiling statements")
1352 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1354 -- Load any orphan-module and family instance-module
1355 -- interfaces, so their instances are visible.
1356 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1357 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1359 -- Check that the family instances of all directly loaded
1360 -- modules are consistent.
1361 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1363 ; ifaceExportNames (mi_exports iface)
1366 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1367 tcRnLookupRdrName hsc_env rdr_name
1368 = initTcPrintErrors hsc_env iNTERACTIVE $
1369 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1370 lookup_rdr_name rdr_name
1372 lookup_rdr_name :: RdrName -> TcM [Name]
1373 lookup_rdr_name rdr_name = do {
1374 -- If the identifier is a constructor (begins with an
1375 -- upper-case letter), then we need to consider both
1376 -- constructor and type class identifiers.
1377 let { rdr_names = dataTcOccs rdr_name } ;
1379 -- results :: [Either Messages Name]
1380 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1382 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1383 -- The successful lookups will be (Just name)
1384 let { (warns_s, good_names) = unzip [ (msgs, name)
1385 | (msgs, Just name) <- results] ;
1386 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1388 -- Fail if nothing good happened, else add warnings
1389 if null good_names then
1390 -- No lookup succeeded, so
1391 -- pick the first error message and report it
1392 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1393 -- while the other is "X is not in scope",
1394 -- we definitely want the former; but we might pick the latter
1395 do { addMessages (head errs_s) ; failM }
1396 else -- Add deprecation warnings
1397 mapM_ addMessages warns_s ;
1402 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1403 tcRnLookupName hsc_env name
1404 = initTcPrintErrors hsc_env iNTERACTIVE $
1405 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1406 tcRnLookupName' name
1408 -- To look up a name we have to look in the local environment (tcl_lcl)
1409 -- as well as the global environment, which is what tcLookup does.
1410 -- But we also want a TyThing, so we have to convert:
1412 tcRnLookupName' :: Name -> TcRn TyThing
1413 tcRnLookupName' name = do
1414 tcthing <- tcLookup name
1416 AGlobal thing -> return thing
1417 ATcId{tct_id=id} -> return (AnId id)
1418 _ -> panic "tcRnLookupName'"
1420 tcRnGetInfo :: HscEnv
1422 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1424 -- Used to implement :info in GHCi
1426 -- Look up a RdrName and return all the TyThings it might be
1427 -- A capitalised RdrName is given to us in the DataName namespace,
1428 -- but we want to treat it as *both* a data constructor
1429 -- *and* as a type or class constructor;
1430 -- hence the call to dataTcOccs, and we return up to two results
1431 tcRnGetInfo hsc_env name
1432 = initTcPrintErrors hsc_env iNTERACTIVE $
1433 let ictxt = hsc_IC hsc_env in
1434 setInteractiveContext hsc_env ictxt $ do
1436 -- Load the interface for all unqualified types and classes
1437 -- That way we will find all the instance declarations
1438 -- (Packages have not orphan modules, and we assume that
1439 -- in the home package all relevant modules are loaded.)
1440 loadUnqualIfaces ictxt
1442 thing <- tcRnLookupName' name
1443 fixity <- lookupFixityRn name
1444 ispecs <- lookupInsts thing
1445 return (thing, fixity, ispecs)
1447 lookupInsts :: TyThing -> TcM [Instance]
1448 lookupInsts (AClass cls)
1449 = do { inst_envs <- tcGetInstEnvs
1450 ; return (classInstances inst_envs cls) }
1452 lookupInsts (ATyCon tc)
1453 = do { (pkg_ie, home_ie) <- tcGetInstEnvs
1454 -- Load all instances for all classes that are
1455 -- in the type environment (which are all the ones
1456 -- we've seen in any interface file so far)
1457 ; return [ ispec -- Search all
1458 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1459 , let dfun = instanceDFunId ispec
1462 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1463 tc_name = tyConName tc
1465 lookupInsts _ = return []
1467 loadUnqualIfaces :: InteractiveContext -> TcM ()
1468 -- Load the home module for everything that is in scope unqualified
1469 -- This is so that we can accurately report the instances for
1471 loadUnqualIfaces ictxt
1473 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1475 unqual_mods = [ nameModule name
1476 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1477 let name = gre_name gre,
1478 not (isInternalName name),
1479 isTcOcc (nameOccName name), -- Types and classes only
1480 unQualOK gre ] -- In scope unqualified
1481 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1485 %************************************************************************
1489 %************************************************************************
1492 rnDump :: SDoc -> TcRn ()
1493 -- Dump, with a banner, if -ddump-rn
1494 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1496 tcDump :: TcGblEnv -> TcRn ()
1498 = do { dflags <- getDOpts ;
1500 -- Dump short output if -ddump-types or -ddump-tc
1501 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1502 (dumpTcRn short_dump) ;
1504 -- Dump bindings if -ddump-tc
1505 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1508 short_dump = pprTcGblEnv env
1509 full_dump = pprLHsBinds (tcg_binds env)
1510 -- NB: foreign x-d's have undefined's in their types;
1511 -- hence can't show the tc_fords
1513 tcCoreDump :: ModGuts -> TcM ()
1515 = do { dflags <- getDOpts ;
1516 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1517 (dumpTcRn (pprModGuts mod_guts)) ;
1519 -- Dump bindings if -ddump-tc
1520 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1522 full_dump = pprCoreBindings (mg_binds mod_guts)
1524 -- It's unpleasant having both pprModGuts and pprModDetails here
1525 pprTcGblEnv :: TcGblEnv -> SDoc
1526 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1528 tcg_fam_insts = fam_insts,
1530 tcg_imports = imports })
1531 = vcat [ ppr_types insts type_env
1532 , ppr_tycons fam_insts type_env
1534 , ppr_fam_insts fam_insts
1535 , vcat (map ppr rules)
1536 , ppr_gen_tycons (typeEnvTyCons type_env)
1537 , ptext (sLit "Dependent modules:") <+>
1538 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1539 , ptext (sLit "Dependent packages:") <+>
1540 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1541 where -- The two uses of sortBy are just to reduce unnecessary
1542 -- wobbling in testsuite output
1543 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1544 = (mod_name1 `stableModuleNameCmp` mod_name2)
1546 (is_boot1 `compare` is_boot2)
1548 pprModGuts :: ModGuts -> SDoc
1549 pprModGuts (ModGuts { mg_types = type_env,
1551 = vcat [ ppr_types [] type_env,
1554 ppr_types :: [Instance] -> TypeEnv -> SDoc
1555 ppr_types insts type_env
1556 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1558 dfun_ids = map instanceDFunId insts
1559 ids = [id | id <- typeEnvIds type_env, want_sig id]
1560 want_sig id | opt_PprStyle_Debug = True
1561 | otherwise = isLocalId id &&
1562 isExternalName (idName id) &&
1563 not (id `elem` dfun_ids)
1564 -- isLocalId ignores data constructors, records selectors etc.
1565 -- The isExternalName ignores local dictionary and method bindings
1566 -- that the type checker has invented. Top-level user-defined things
1567 -- have External names.
1569 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1570 ppr_tycons fam_insts type_env
1571 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1573 fi_tycons = map famInstTyCon fam_insts
1574 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1575 want_tycon tycon | opt_PprStyle_Debug = True
1576 | otherwise = not (isImplicitTyCon tycon) &&
1577 isExternalName (tyConName tycon) &&
1578 not (tycon `elem` fi_tycons)
1580 ppr_insts :: [Instance] -> SDoc
1581 ppr_insts [] = empty
1582 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1584 ppr_fam_insts :: [FamInst] -> SDoc
1585 ppr_fam_insts [] = empty
1586 ppr_fam_insts fam_insts =
1587 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1589 ppr_sigs :: [Var] -> SDoc
1591 -- Print type signatures; sort by OccName
1592 = vcat (map ppr_sig (sortLe le_sig ids))
1594 le_sig id1 id2 = getOccName id1 <= getOccName id2
1595 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1597 ppr_tydecls :: [TyCon] -> SDoc
1599 -- Print type constructor info; sort by OccName
1600 = vcat (map ppr_tycon (sortLe le_sig tycons))
1602 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1604 | isCoercionTyCon tycon
1605 = sep [ptext (sLit "coercion") <+> ppr tycon <+> ppr tvs
1606 , nest 2 (dcolon <+> pprEqPred (coercionKind (mkTyConApp tycon (mkTyVarTys tvs))))]
1607 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1609 tvs = take (tyConArity tycon) alphaTyVars
1611 ppr_rules :: [CoreRule] -> SDoc
1612 ppr_rules [] = empty
1613 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1614 nest 4 (pprRules rs),
1617 ppr_gen_tycons :: [TyCon] -> SDoc
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)))]