2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
5 \section[TcModule]{Typechecking a whole module}
9 -- The above warning supression flag is a temporary kludge.
10 -- While working on this module you are encouraged to remove it and fix
11 -- any warnings in the module. See
12 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
17 tcRnStmt, tcRnExpr, tcRnType,
30 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
59 import TcUnify ( withBox )
85 import Data.List ( sortBy )
97 import {- Kind parts of -} Type
99 import Foreign.Ptr( Ptr )
100 import TidyPgm ( globaliseAndTidyId )
109 import Data.Maybe ( isJust )
111 #include "HsVersions.h"
114 %************************************************************************
116 Typecheck and rename a module
118 %************************************************************************
124 -> Bool -- True <=> save renamed syntax
125 -> Located (HsModule RdrName)
126 -> IO (Messages, Maybe TcGblEnv)
128 tcRnModule hsc_env hsc_src save_rn_syntax
129 (L loc (HsModule maybe_mod export_ies
130 import_decls local_decls mod_deprec
132 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
134 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
135 this_mod = case maybe_mod of
136 Nothing -> mAIN -- 'module M where' is omitted
137 Just (L _ mod) -> mkModule this_pkg mod } ;
140 initTc hsc_env hsc_src save_rn_syntax this_mod $
142 do { -- Deal with imports;
143 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
144 setGblEnv tcg_env $ do {
146 -- Load the hi-boot interface for this module, if any
147 -- We do this now so that the boot_names can be passed
148 -- to tcTyAndClassDecls, because the boot_names are
149 -- automatically considered to be loop breakers
151 -- Do this *after* tcRnImports, so that we know whether
152 -- a module that we import imports us; and hence whether to
153 -- look for a hi-boot file
154 boot_iface <- tcHiBootIface hsc_src this_mod ;
156 -- Rename and type check the declarations
157 traceRn (text "rn1a") ;
158 tcg_env <- if isHsBoot hsc_src then
159 tcRnHsBootDecls local_decls
161 tcRnSrcDecls boot_iface local_decls ;
162 setGblEnv tcg_env $ do {
164 -- Report the use of any deprecated things
165 -- We do this *before* processsing the export list so
166 -- that we don't bleat about re-exporting a deprecated
167 -- thing (especially via 'module Foo' export item)
168 -- That is, only uses in the *body* of the module are complained about
169 traceRn (text "rn3") ;
170 failIfErrsM ; -- finishWarnings crashes sometimes
171 -- as a result of typechecker repairs (e.g. unboundNames)
172 tcg_env <- finishWarnings (hsc_dflags hsc_env) mod_deprec tcg_env ;
174 -- Process the export list
175 traceRn (text "rn4a: before exports");
176 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
177 traceRn (text "rn4b: after exportss") ;
179 -- Compare the hi-boot iface (if any) with the real thing
180 -- Must be done after processing the exports
181 tcg_env <- checkHiBootIface tcg_env boot_iface ;
183 -- The new type env is already available to stuff slurped from
184 -- interface files, via TcEnv.updateGlobalTypeEnv
185 -- It's important that this includes the stuff in checkHiBootIface,
186 -- because the latter might add new bindings for boot_dfuns,
187 -- which may be mentioned in imported unfoldings
189 -- Don't need to rename the Haddock documentation,
190 -- it's not parsed by GHC anymore.
191 tcg_env <- return (tcg_env { tcg_doc_hdr = maybe_doc_hdr }) ;
193 -- Report unused names
194 reportUnusedNames export_ies tcg_env ;
196 -- Dump output and return
203 %************************************************************************
207 %************************************************************************
210 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
211 tcRnImports hsc_env this_mod import_decls
212 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
214 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
215 ; dep_mods = imp_dep_mods imports
217 -- We want instance declarations from all home-package
218 -- modules below this one, including boot modules, except
219 -- ourselves. The 'except ourselves' is so that we don't
220 -- get the instances from this module's hs-boot file
221 ; want_instances :: ModuleName -> Bool
222 ; want_instances mod = mod `elemUFM` dep_mods
223 && mod /= moduleName this_mod
224 ; (home_insts, home_fam_insts) = hptInstances hsc_env
228 -- Record boot-file info in the EPS, so that it's
229 -- visible to loadHiBootInterface in tcRnSrcDecls,
230 -- and any other incrementally-performed imports
231 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
233 -- Update the gbl env
234 ; updGblEnv ( \ gbl ->
236 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
237 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
238 tcg_rn_imports = rn_imports,
239 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
240 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
245 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
246 -- Fail if there are any errors so far
247 -- The error printing (if needed) takes advantage
248 -- of the tcg_env we have now set
249 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
252 -- Load any orphan-module and family instance-module
253 -- interfaces, so that their rules and instance decls will be
255 ; loadOrphanModules (imp_orphs imports) False
256 ; loadOrphanModules (imp_finsts imports) True
258 -- Check type-familily consistency
259 ; traceRn (text "rn1: checking family instance consistency")
260 ; let { dir_imp_mods = moduleEnvKeys
263 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
269 %************************************************************************
271 Type-checking external-core modules
273 %************************************************************************
276 tcRnExtCore :: HscEnv
278 -> IO (Messages, Maybe ModGuts)
279 -- Nothing => some error occurred
281 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
282 -- The decls are IfaceDecls; all names are original names
283 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
285 initTc hsc_env ExtCoreFile False this_mod $ do {
287 let { ldecls = map noLoc decls } ;
289 -- bring the type and class decls into scope
290 -- ToDo: check that this doesn't need to extract the val binds.
291 -- It seems that only the type and class decls need to be in scope below because
292 -- (a) tcTyAndClassDecls doesn't need the val binds, and
293 -- (b) tcExtCoreBindings doesn't need anything
294 -- (in fact, it might not even need to be in the scope of
295 -- this tcg_env at all)
296 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
297 tc_envs <- extendGlobalRdrEnvRn avails emptyFsEnv {- no fixity decls -} ;
299 setEnvs tc_envs $ do {
301 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
303 -- Dump trace of renaming part
304 rnDump (ppr rn_decls) ;
306 -- Typecheck them all together so that
307 -- any mutually recursive types are done right
308 -- Just discard the auxiliary bindings; they are generated
309 -- only for Haskell source code, and should already be in Core
310 (tcg_env, _aux_binds) <- tcTyAndClassDecls emptyModDetails rn_decls ;
312 setGblEnv tcg_env $ do {
313 -- Make the new type env available to stuff slurped from interface files
315 -- Now the core bindings
316 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
320 bndrs = bindersOfBinds core_binds ;
321 my_exports = map (Avail . idName) bndrs ;
322 -- ToDo: export the data types also?
325 extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
327 mod_guts = ModGuts { mg_module = this_mod,
329 mg_used_names = emptyNameSet, -- ToDo: compute usage
330 mg_dir_imps = emptyModuleEnv, -- ??
331 mg_deps = noDependencies, -- ??
332 mg_exports = my_exports,
333 mg_types = final_type_env,
334 mg_insts = tcg_insts tcg_env,
335 mg_fam_insts = tcg_fam_insts tcg_env,
336 mg_inst_env = tcg_inst_env tcg_env,
337 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
339 mg_binds = core_binds,
342 mg_rdr_env = emptyGlobalRdrEnv,
343 mg_fix_env = emptyFixityEnv,
344 mg_warns = NoWarnings,
345 mg_foreign = NoStubs,
346 mg_hpc_info = emptyHpcInfo False,
347 mg_modBreaks = emptyModBreaks,
348 mg_vect_info = noVectInfo
351 tcCoreDump mod_guts ;
356 mkFakeGroup decls -- Rather clumsy; lots of unused fields
357 = emptyRdrGroup { hs_tyclds = decls }
361 %************************************************************************
363 Type-checking the top level of a module
365 %************************************************************************
368 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
369 -- Returns the variables free in the decls
370 -- Reason: solely to report unused imports and bindings
371 tcRnSrcDecls boot_iface decls
372 = do { -- Do all the declarations
373 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
375 -- Finish simplifying class constraints
377 -- tcSimplifyTop deals with constant or ambiguous InstIds.
378 -- How could there be ambiguous ones? They can only arise if a
379 -- top-level decl falls under the monomorphism restriction
380 -- and no subsequent decl instantiates its type.
382 -- We do this after checkMain, so that we use the type info
383 -- thaat checkMain adds
385 -- We do it with both global and local env in scope:
386 -- * the global env exposes the instances to tcSimplifyTop
387 -- * the local env exposes the local Ids to tcSimplifyTop,
388 -- so that we get better error messages (monomorphism restriction)
389 traceTc (text "Tc8") ;
390 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
392 -- Backsubstitution. This must be done last.
393 -- Even tcSimplifyTop may do some unification.
394 traceTc (text "Tc9") ;
395 let { (tcg_env, _) = tc_envs
396 ; TcGblEnv { tcg_type_env = type_env,
399 tcg_fords = fords } = tcg_env
400 ; all_binds = binds `unionBags` inst_binds } ;
402 failIfErrsM ; -- Don't zonk if there have been errors
403 -- It's a waste of time; and we may get debug warnings
404 -- about strangely-typed TyCons!
406 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
409 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
410 ; tcg_env' = tcg_env { tcg_binds = binds',
412 tcg_fords = fords' } } ;
414 setGlobalTypeEnv tcg_env' final_type_env
417 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
418 -- Loops around dealing with each top level inter-splice group
419 -- in turn, until it's dealt with the entire module
420 tc_rn_src_decls boot_details ds
421 = do { let { (first_group, group_tail) = findSplice ds } ;
422 -- If ds is [] we get ([], Nothing)
424 -- Deal with decls up to, but not including, the first splice
425 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
426 -- rnTopSrcDecls fails if there are any errors
428 (tcg_env, tcl_env) <- setGblEnv tcg_env $
429 tcTopSrcDecls boot_details rn_decls ;
431 -- If there is no splice, we're nearly done
432 setEnvs (tcg_env, tcl_env) $
434 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
435 return (tcg_env, tcl_env)
438 -- If there's a splice, we must carry on
439 Just (SpliceDecl splice_expr, rest_ds) -> do {
441 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
444 -- Rename the splice expression, and get its supporting decls
445 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
446 -- checkNoErrs: don't typecheck if renaming failed
447 rnDump (ppr rn_splice_expr) ;
449 -- Execute the splice
450 spliced_decls <- tcSpliceDecls rn_splice_expr ;
452 -- Glue them on the front of the remaining decls and loop
453 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
454 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
459 %************************************************************************
461 Compiling hs-boot source files, and
462 comparing the hi-boot interface with the real thing
464 %************************************************************************
467 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
468 tcRnHsBootDecls decls
469 = do { let { (first_group, group_tail) = findSplice decls }
472 Just stuff -> spliceInHsBootErr stuff
475 -- Rename the declarations
476 ; (tcg_env, HsGroup {
477 hs_tyclds = tycl_decls,
478 hs_instds = inst_decls,
479 hs_derivds = deriv_decls,
481 hs_defds = _, -- Todo: check no foreign decls, no rules,
482 hs_ruleds = _, -- no default decls and no annotation decls
484 hs_valds = val_binds }) <- rnTopSrcDecls first_group
485 ; setGblEnv tcg_env $ do {
488 -- Typecheck type/class decls
489 ; traceTc (text "Tc2")
490 ; (tcg_env, aux_binds) <- tcTyAndClassDecls emptyModDetails tycl_decls
491 ; setGblEnv tcg_env $ do {
493 -- Typecheck instance decls
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_env1 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_env2
525 spliceInHsBootErr (SpliceDecl (L loc _), _)
526 = addErrAt loc (ptext (sLit "Splices are not allowed in hs-boot files"))
529 Once we've typechecked the body of the module, we want to compare what
530 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
533 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
534 -- Compare the hi-boot file for this module (if there is one)
535 -- with the type environment we've just come up with
536 -- In the common case where there is no hi-boot file, the list
537 -- of boot_names is empty.
539 -- The bindings we return give bindings for the dfuns defined in the
540 -- hs-boot file, such as $fbEqT = $fEqT
543 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
544 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
545 tcg_type_env = local_type_env, tcg_exports = local_exports })
546 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
547 md_types = boot_type_env, md_exports = boot_exports })
548 | isHsBoot hs_src -- Current module is already a hs-boot file!
552 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
555 -- Check the exports of the boot module, one by one
556 ; mapM_ check_export boot_exports
558 -- Check instance declarations
559 ; mb_dfun_prs <- mapM check_inst boot_insts
560 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds,
561 tcg_type_env = extendTypeEnvWithIds local_type_env boot_dfuns }
562 dfun_prs = catMaybes mb_dfun_prs
563 boot_dfuns = map fst dfun_prs
564 dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun)
565 | (boot_dfun, dfun) <- dfun_prs ]
567 -- Check for no family instances
568 ; unless (null boot_fam_insts) $
569 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
570 "instances in boot files yet...")
571 -- FIXME: Why? The actual comparison is not hard, but what would
572 -- be the equivalent to the dfun bindings returned for class
573 -- instances? We can't easily equate tycons...
575 -- Check instance declarations
576 ; mb_dfun_prs <- mapM check_inst boot_insts
577 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
578 final_type_env = extendTypeEnvWithIds local_type_env boot_dfuns
579 dfun_prs = catMaybes mb_dfun_prs
580 boot_dfuns = map fst dfun_prs
581 dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun)
582 | (boot_dfun, dfun) <- dfun_prs ]
585 ; setGlobalTypeEnv tcg_env' final_type_env }
587 check_export boot_avail -- boot_avail is exported by the boot iface
588 | name `elem` dfun_names = return ()
589 | isWiredInName name = return () -- No checking for wired-in names. In particular,
590 -- 'error' is handled by a rather gross hack
591 -- (see comments in GHC.Err.hs-boot)
593 -- Check that the actual module exports the same thing
594 | not (null missing_names)
595 = addErrAt (nameSrcSpan (head missing_names))
596 (missingBootThing (head missing_names) "exported by")
598 -- If the boot module does not *define* the thing, we are done
599 -- (it simply re-exports it, and names match, so nothing further to do)
600 | isNothing mb_boot_thing = return ()
602 -- Check that the actual module also defines the thing, and
603 -- then compare the definitions
604 | Just real_thing <- lookupTypeEnv local_type_env name,
605 Just boot_thing <- mb_boot_thing
606 = when (not (checkBootDecl boot_thing real_thing))
607 $ addErrAt (nameSrcSpan (getName boot_thing))
608 (let boot_decl = tyThingToIfaceDecl
609 (fromJust mb_boot_thing)
610 real_decl = tyThingToIfaceDecl real_thing
611 in bootMisMatch real_thing boot_decl real_decl)
614 = addErrTc (missingBootThing name "defined in")
616 name = availName boot_avail
617 mb_boot_thing = lookupTypeEnv boot_type_env name
618 missing_names = case lookupNameEnv local_export_env name of
620 Just avail -> availNames boot_avail `minusList` availNames avail
622 dfun_names = map getName boot_insts
624 local_export_env :: NameEnv AvailInfo
625 local_export_env = availsToNameEnv local_exports
627 check_inst :: Instance -> TcM (Maybe (Id, Id))
628 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
630 = case [dfun | inst <- local_insts,
631 let dfun = instanceDFunId inst,
632 idType dfun `tcEqType` boot_inst_ty ] of
633 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
634 (dfun:_) -> return (Just (local_boot_dfun, dfun))
636 boot_dfun = instanceDFunId boot_inst
637 boot_inst_ty = idType boot_dfun
638 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
641 -- This has to compare the TyThing from the .hi-boot file to the TyThing
642 -- in the current source file. We must be careful to allow alpha-renaming
643 -- where appropriate, and also the boot declaration is allowed to omit
644 -- constructors and class methods.
646 -- See rnfail055 for a good test of this stuff.
648 checkBootDecl :: TyThing -> TyThing -> Bool
650 checkBootDecl (AnId id1) (AnId id2)
652 (idType id1 `tcEqType` idType id2)
654 checkBootDecl (ATyCon tc1) (ATyCon tc2)
655 = checkBootTyCon tc1 tc2
657 checkBootDecl (AClass c1) (AClass c2)
659 (clas_tyvars1, clas_fds1, sc_theta1, _, ats1, op_stuff1)
660 = classExtraBigSig c1
661 (clas_tyvars2, clas_fds2, sc_theta2, _, ats2, op_stuff2)
662 = classExtraBigSig c2
664 env0 = mkRnEnv2 emptyInScopeSet
665 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
667 eqSig (id1, def_meth1) (id2, def_meth2)
668 = idName id1 == idName id2 &&
669 tcEqTypeX env op_ty1 op_ty2
671 (_, rho_ty1) = splitForAllTys (idType id1)
672 op_ty1 = funResultTy rho_ty1
673 (_, rho_ty2) = splitForAllTys (idType id2)
674 op_ty2 = funResultTy rho_ty2
676 eqFD (as1,bs1) (as2,bs2) =
677 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
678 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
680 same_kind tv1 tv2 = eqKind (tyVarKind tv1) (tyVarKind tv2)
682 eqListBy same_kind clas_tyvars1 clas_tyvars2 &&
683 -- Checks kind of class
684 eqListBy eqFD clas_fds1 clas_fds2 &&
685 (null sc_theta1 && null op_stuff1 && null ats1
686 || -- Above tests for an "abstract" class
687 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
688 eqListBy eqSig op_stuff1 op_stuff2 &&
689 eqListBy checkBootTyCon ats1 ats2)
691 checkBootDecl (ADataCon dc1) (ADataCon dc2)
692 = pprPanic "checkBootDecl" (ppr dc1)
694 checkBootDecl _ _ = False -- probably shouldn't happen
697 checkBootTyCon :: TyCon -> TyCon -> Bool
698 checkBootTyCon tc1 tc2
699 | not (eqKind (tyConKind tc1) (tyConKind tc2))
700 = False -- First off, check the kind
702 | isSynTyCon tc1 && isSynTyCon tc2
704 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
705 env = rnBndrs2 env0 tvs1 tvs2
707 eqSynRhs (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
708 = tcEqTypeX env k1 k2
709 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
710 = tcEqTypeX env t1 t2
712 equalLength tvs1 tvs2 &&
713 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
715 | isAlgTyCon tc1 && isAlgTyCon tc2
717 eqKind (tyConKind tc1) (tyConKind tc2) &&
718 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2) &&
719 eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
721 | isForeignTyCon tc1 && isForeignTyCon tc2
722 = eqKind (tyConKind tc1) (tyConKind tc2) &&
723 tyConExtName tc1 == tyConExtName tc2
725 env0 = mkRnEnv2 emptyInScopeSet
727 eqAlgRhs AbstractTyCon _ = True
728 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
729 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
730 eqListBy eqCon (data_cons tc1) (data_cons tc2)
731 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
732 eqCon (data_con tc1) (data_con tc2)
736 = dataConName c1 == dataConName c2
737 && dataConIsInfix c1 == dataConIsInfix c2
738 && dataConStrictMarks c1 == dataConStrictMarks c2
739 && dataConFieldLabels c1 == dataConFieldLabels c2
740 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
741 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
742 env = rnBndrs2 env0 tvs1 tvs2
744 equalLength tvs1 tvs2 &&
745 eqListBy (tcEqPredX env)
746 (dataConEqTheta c1 ++ dataConDictTheta c1)
747 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
748 eqListBy (tcEqTypeX env)
749 (dataConOrigArgTys c1)
750 (dataConOrigArgTys c2)
753 missingBootThing thing what
754 = ppr thing <+> ptext (sLit "is exported by the hs-boot file, but not")
755 <+> text what <+> ptext (sLit "the module")
757 bootMisMatch thing boot_decl real_decl
758 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
759 ptext (sLit "Main module:") <+> ppr real_decl,
760 ptext (sLit "Boot file: ") <+> ppr boot_decl]
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 dflags tcg_env
909 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
913 = do { mb_main <- lookupGlobalOccRn_maybe main_fn
914 -- Check that 'main' is in scope
915 -- It might be imported from another module!
917 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
922 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
923 ; let loc = srcLocSpan (getSrcLoc main_name)
924 ; ioTyCon <- tcLookupTyCon ioTyConName
925 ; (main_expr, res_ty)
926 <- addErrCtxt mainCtxt $
927 withBox liftedTypeKind $ \res_ty ->
928 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
930 -- See Note [Root-main Id]
931 -- Construct the binding
932 -- :Main.main :: IO res_ty = runMainIO res_ty main
933 ; run_main_id <- tcLookupId runMainIOName
934 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
935 (mkVarOccFS (fsLit "main"))
936 (getSrcSpan main_name)
937 ; root_main_id = Id.mkExportedLocalId root_main_name
938 (mkTyConApp ioTyCon [res_ty])
939 ; co = mkWpTyApps [res_ty]
940 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
941 ; main_bind = mkVarBind root_main_id rhs }
943 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
945 tcg_dus = tcg_dus tcg_env
946 `plusDU` usesOnly (unitFV main_name)
947 -- Record the use of 'main', so that we don't
948 -- complain about it being defined but not used
952 mod = tcg_mod tcg_env
953 main_mod = mainModIs dflags
954 main_fn = getMainFun dflags
956 complain_no_main | ghcLink dflags == LinkInMemory = return ()
957 | otherwise = failWithTc noMainMsg
958 -- In interactive mode, don't worry about the absence of 'main'
959 -- In other modes, fail altogether, so that we don't go on
960 -- and complain a second time when processing the export list.
962 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
963 noMainMsg = ptext (sLit "The") <+> pp_main_fn
964 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
965 pp_main_fn | main_fn == main_RDR_Unqual = ptext (sLit "function") <+> quotes (ppr main_fn)
966 | otherwise = ptext (sLit "main function") <+> quotes (ppr main_fn)
968 -- | Get the unqualified name of the function to use as the \"main\" for the main module.
969 -- Either returns the default name or the one configured on the command line with -main-is
970 getMainFun :: DynFlags -> RdrName
971 getMainFun dflags = case (mainFunIs dflags) of
972 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
973 Nothing -> main_RDR_Unqual
978 The function that the RTS invokes is always :Main.main, which we call
979 root_main_id. (Because GHC allows the user to have a module not
980 called Main as the main module, we can't rely on the main function
981 being called "Main.main". That's why root_main_id has a fixed module
984 This is unusual: it's a LocalId whose Name has a Module from another
985 module. Tiresomely, we must filter it out again in MkIface, les we
986 get two defns for 'main' in the interface file!
989 %*********************************************************
993 %*********************************************************
997 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
998 setInteractiveContext hsc_env icxt thing_inside
999 = let -- Initialise the tcg_inst_env with instances from all home modules.
1000 -- This mimics the more selective call to hptInstances in tcRnModule.
1001 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
1003 updGblEnv (\env -> env {
1004 tcg_rdr_env = ic_rn_gbl_env icxt,
1005 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
1006 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
1010 tcExtendGhciEnv (ic_tmp_ids icxt) $
1011 -- tcExtendGhciEnv does lots:
1012 -- - it extends the local type env (tcl_env) with the given Ids,
1013 -- - it extends the local rdr env (tcl_rdr) with the Names from
1015 -- - it adds the free tyvars of the Ids to the tcl_tyvars
1018 -- later ids in ic_tmp_ids must shadow earlier ones with the same
1019 -- OccName, and tcExtendIdEnv implements this behaviour.
1021 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
1028 -> InteractiveContext
1030 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1031 -- The returned [Id] is the list of new Ids bound by
1032 -- this statement. It can be used to extend the
1033 -- InteractiveContext via extendInteractiveContext.
1035 -- The returned TypecheckedHsExpr is of type IO [ () ],
1036 -- a list of the bound values, coerced to ().
1038 tcRnStmt hsc_env ictxt rdr_stmt
1039 = initTcPrintErrors hsc_env iNTERACTIVE $
1040 setInteractiveContext hsc_env ictxt $ do {
1042 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1043 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
1044 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1046 rnDump (ppr rn_stmt) ;
1048 -- The real work is done here
1049 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1050 zonked_expr <- zonkTopLExpr tc_expr ;
1051 zonked_ids <- zonkTopBndrs bound_ids ;
1053 -- None of the Ids should be of unboxed type, because we
1054 -- cast them all to HValues in the end!
1055 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1057 traceTc (text "tcs 1") ;
1058 let { global_ids = map globaliseAndTidyId zonked_ids } ;
1059 -- Note [Interactively-bound Ids in GHCi]
1061 {- ---------------------------------------------
1062 At one stage I removed any shadowed bindings from the type_env;
1063 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1064 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1066 Prelude> let f n = n * 2 :: Int
1067 Prelude> fName <- runQ [| f |]
1068 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1070 Prelude> let f n = n * 3 :: Int
1071 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1072 In the last line we use 'fName', which resolves to the *first* 'f'
1073 in scope. If we delete it from the type env, GHCi crashes because
1074 it doesn't expect that.
1076 Hence this code is commented out
1078 -------------------------------------------------- -}
1080 dumpOptTcRn Opt_D_dump_tc
1081 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1082 text "Typechecked expr" <+> ppr zonked_expr]) ;
1084 return (global_ids, zonked_expr)
1087 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1088 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1091 Note [Interactively-bound Ids in GHCi]
1092 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1093 The Ids bound by previous Stmts in Template Haskell are currently
1095 b) with an Internal Name (not External)
1096 c) and a tidied type
1098 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1099 compile an expression using these ids later, the byte code
1100 generator will consider the occurrences to be free rather than
1103 (b) They retain their Internal names becuase we don't have a suitable
1104 Module to name them with. We could revisit this choice.
1106 (c) Their types are tidied. This is important, because :info may ask
1107 to look at them, and :info expects the things it looks up to have
1111 --------------------------------------------------------------------------
1112 Typechecking Stmts in GHCi
1114 Here is the grand plan, implemented in tcUserStmt
1116 What you type The IO [HValue] that hscStmt returns
1117 ------------- ------------------------------------
1118 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1121 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1124 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1125 [NB: result not printed] bindings: [it]
1127 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1128 result showable) bindings: [it]
1130 expr (of non-IO type,
1131 result not showable) ==> error
1135 ---------------------------
1136 type PlanResult = ([Id], LHsExpr Id)
1137 type Plan = TcM PlanResult
1139 runPlans :: [Plan] -> TcM PlanResult
1140 -- Try the plans in order. If one fails (by raising an exn), try the next.
1141 -- If one succeeds, take it.
1142 runPlans [] = panic "runPlans"
1144 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1146 --------------------
1147 mkPlan :: LStmt Name -> TcM PlanResult
1148 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1149 = do { uniq <- newUnique -- is treated very specially
1150 ; let fresh_it = itName uniq
1151 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1152 matches = [mkMatch [] expr emptyLocalBinds]
1153 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1154 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1155 (HsVar bindIOName) noSyntaxExpr
1156 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1157 (HsVar thenIOName) placeHolderType
1160 -- [it <- e; print it] but not if it::()
1162 -- [let it = e; print it]
1163 ; runPlans [ -- Plan A
1164 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1165 ; it_ty <- zonkTcType (idType it_id)
1166 ; when (isUnitTy it_ty) failM
1169 -- Plan B; a naked bind statment
1170 tcGhciStmts [bind_stmt],
1172 -- Plan C; check that the let-binding is typeable all by itself.
1173 -- If not, fail; if so, try to print it.
1174 -- The two-step process avoids getting two errors: one from
1175 -- the expression itself, and one from the 'print it' part
1176 -- This two-step story is very clunky, alas
1177 do { checkNoErrs (tcGhciStmts [let_stmt])
1178 --- checkNoErrs defeats the error recovery of let-bindings
1179 ; tcGhciStmts [let_stmt, print_it] }
1182 mkPlan stmt@(L loc (BindStmt {}))
1183 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1184 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1185 (HsVar thenIOName) placeHolderType
1187 ; print_bind_result <- doptM Opt_PrintBindResult
1188 ; let print_plan = do
1189 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1190 ; v_ty <- zonkTcType (idType v_id)
1191 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1195 -- [stmt; print v] but not if v::()
1197 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1198 [tcGhciStmts [stmt]])
1202 = tcGhciStmts [stmt]
1204 ---------------------------
1205 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1207 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1208 ret_id <- tcLookupId returnIOName ; -- return @ IO
1210 ret_ty = mkListTy unitTy ;
1211 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1212 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1214 names = map unLoc (collectLStmtsBinders stmts) ;
1216 -- mk_return builds the expression
1217 -- returnIO @ [()] [coerce () x, .., coerce () z]
1219 -- Despite the inconvenience of building the type applications etc,
1220 -- this *has* to be done in type-annotated post-typecheck form
1221 -- because we are going to return a list of *polymorphic* values
1222 -- coerced to type (). If we built a *source* stmt
1223 -- return [coerce x, ..., coerce z]
1224 -- then the type checker would instantiate x..z, and we wouldn't
1225 -- get their *polymorphic* values. (And we'd get ambiguity errs
1226 -- if they were overloaded, since they aren't applied to anything.)
1227 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1228 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1229 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1233 -- OK, we're ready to typecheck the stmts
1234 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1235 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1236 mapM tcLookupId names ;
1237 -- Look up the names right in the middle,
1238 -- where they will all be in scope
1240 -- Simplify the context
1241 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1242 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1243 -- checkNoErrs ensures that the plan fails if context redn fails
1245 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1246 return (ids, mkHsDictLet const_binds $
1247 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1252 tcRnExpr just finds the type of an expression
1256 -> InteractiveContext
1258 -> IO (Messages, Maybe Type)
1259 tcRnExpr hsc_env ictxt rdr_expr
1260 = initTcPrintErrors hsc_env iNTERACTIVE $
1261 setInteractiveContext hsc_env ictxt $ do {
1263 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1266 -- Now typecheck the expression;
1267 -- it might have a rank-2 type (e.g. :t runST)
1268 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1269 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1270 tcSimplifyInteractive lie_top ;
1272 let { all_expr_ty = mkForAllTys qtvs $
1273 mkFunTys (map (idType . instToId) dict_insts) $
1275 zonkTcType all_expr_ty
1278 smpl_doc = ptext (sLit "main expression")
1281 tcRnType just finds the kind of a type
1285 -> InteractiveContext
1287 -> IO (Messages, Maybe Kind)
1288 tcRnType hsc_env ictxt rdr_type
1289 = initTcPrintErrors hsc_env iNTERACTIVE $
1290 setInteractiveContext hsc_env ictxt $ do {
1292 rn_type <- rnLHsType doc rdr_type ;
1295 -- Now kind-check the type
1296 (ty', kind) <- kcLHsType rn_type ;
1300 doc = ptext (sLit "In GHCi input")
1306 %************************************************************************
1308 More GHCi stuff, to do with browsing and getting info
1310 %************************************************************************
1314 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1315 -- a package module with an interface on disk. If neither of these is
1316 -- true, then the result will be an error indicating the interface
1317 -- could not be found.
1318 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1319 getModuleExports hsc_env mod
1322 checkMods = ic_toplev_scope ic ++ ic_exports ic
1324 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1326 -- Get the export avail info and also load all orphan and family-instance
1327 -- modules. Finally, check that the family instances of all modules in the
1328 -- interactive context are consistent (these modules are in the second
1330 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1331 tcGetModuleExports mod directlyImpMods
1332 = do { let doc = ptext (sLit "context for compiling statements")
1333 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1335 -- Load any orphan-module and family instance-module
1336 -- interfaces, so their instances are visible.
1337 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1338 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1340 -- Check that the family instances of all directly loaded
1341 -- modules are consistent.
1342 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1344 ; ifaceExportNames (mi_exports iface)
1347 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1348 tcRnLookupRdrName hsc_env rdr_name
1349 = initTcPrintErrors hsc_env iNTERACTIVE $
1350 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1351 lookup_rdr_name rdr_name
1353 lookup_rdr_name rdr_name = do {
1354 -- If the identifier is a constructor (begins with an
1355 -- upper-case letter), then we need to consider both
1356 -- constructor and type class identifiers.
1357 let { rdr_names = dataTcOccs rdr_name } ;
1359 -- results :: [Either Messages Name]
1360 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1362 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1363 -- The successful lookups will be (Just name)
1364 let { (warns_s, good_names) = unzip [ (msgs, name)
1365 | (msgs, Just name) <- results] ;
1366 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1368 -- Fail if nothing good happened, else add warnings
1369 if null good_names then
1370 -- No lookup succeeded, so
1371 -- pick the first error message and report it
1372 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1373 -- while the other is "X is not in scope",
1374 -- we definitely want the former; but we might pick the latter
1375 do { addMessages (head errs_s) ; failM }
1376 else -- Add deprecation warnings
1377 mapM_ addMessages warns_s ;
1382 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1383 tcRnLookupName hsc_env name
1384 = initTcPrintErrors hsc_env iNTERACTIVE $
1385 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1386 tcRnLookupName' name
1388 -- To look up a name we have to look in the local environment (tcl_lcl)
1389 -- as well as the global environment, which is what tcLookup does.
1390 -- But we also want a TyThing, so we have to convert:
1392 tcRnLookupName' :: Name -> TcRn TyThing
1393 tcRnLookupName' name = do
1394 tcthing <- tcLookup name
1396 AGlobal thing -> return thing
1397 ATcId{tct_id=id} -> return (AnId id)
1398 _ -> panic "tcRnLookupName'"
1400 tcRnGetInfo :: HscEnv
1402 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1404 -- Used to implement :info in GHCi
1406 -- Look up a RdrName and return all the TyThings it might be
1407 -- A capitalised RdrName is given to us in the DataName namespace,
1408 -- but we want to treat it as *both* a data constructor
1409 -- *and* as a type or class constructor;
1410 -- hence the call to dataTcOccs, and we return up to two results
1411 tcRnGetInfo hsc_env name
1412 = initTcPrintErrors hsc_env iNTERACTIVE $
1413 let ictxt = hsc_IC hsc_env in
1414 setInteractiveContext hsc_env ictxt $ do
1416 -- Load the interface for all unqualified types and classes
1417 -- That way we will find all the instance declarations
1418 -- (Packages have not orphan modules, and we assume that
1419 -- in the home package all relevant modules are loaded.)
1420 loadUnqualIfaces ictxt
1422 thing <- tcRnLookupName' name
1423 fixity <- lookupFixityRn name
1424 ispecs <- lookupInsts thing
1425 return (thing, fixity, ispecs)
1427 lookupInsts :: TyThing -> TcM [Instance]
1428 lookupInsts (AClass cls)
1429 = do { inst_envs <- tcGetInstEnvs
1430 ; return (classInstances inst_envs cls) }
1432 lookupInsts (ATyCon tc)
1433 = do { eps <- getEps -- Load all instances for all classes that are
1434 -- in the type environment (which are all the ones
1435 -- we've seen in any interface file so far)
1436 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1438 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1439 , let dfun = instanceDFunId ispec
1442 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1443 tc_name = tyConName tc
1445 lookupInsts other = return []
1447 loadUnqualIfaces :: InteractiveContext -> TcM ()
1448 -- Load the home module for everything that is in scope unqualified
1449 -- This is so that we can accurately report the instances for
1451 loadUnqualIfaces ictxt
1453 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1455 unqual_mods = [ nameModule name
1456 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1457 let name = gre_name gre,
1458 not (isInternalName name),
1459 isTcOcc (nameOccName name), -- Types and classes only
1460 unQualOK gre ] -- In scope unqualified
1461 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1465 %************************************************************************
1469 %************************************************************************
1472 rnDump :: SDoc -> TcRn ()
1473 -- Dump, with a banner, if -ddump-rn
1474 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1476 tcDump :: TcGblEnv -> TcRn ()
1478 = do { dflags <- getDOpts ;
1480 -- Dump short output if -ddump-types or -ddump-tc
1481 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1482 (dumpTcRn short_dump) ;
1484 -- Dump bindings if -ddump-tc
1485 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1488 short_dump = pprTcGblEnv env
1489 full_dump = pprLHsBinds (tcg_binds env)
1490 -- NB: foreign x-d's have undefined's in their types;
1491 -- hence can't show the tc_fords
1494 = do { dflags <- getDOpts ;
1495 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1496 (dumpTcRn (pprModGuts mod_guts)) ;
1498 -- Dump bindings if -ddump-tc
1499 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1501 full_dump = pprCoreBindings (mg_binds mod_guts)
1503 -- It's unpleasant having both pprModGuts and pprModDetails here
1504 pprTcGblEnv :: TcGblEnv -> SDoc
1505 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1507 tcg_fam_insts = fam_insts,
1509 tcg_imports = imports })
1510 = vcat [ ppr_types insts type_env
1511 , ppr_tycons fam_insts type_env
1513 , ppr_fam_insts fam_insts
1514 , vcat (map ppr rules)
1515 , ppr_gen_tycons (typeEnvTyCons type_env)
1516 , ptext (sLit "Dependent modules:") <+>
1517 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1518 , ptext (sLit "Dependent packages:") <+>
1519 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1520 where -- The two uses of sortBy are just to reduce unnecessary
1521 -- wobbling in testsuite output
1522 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1523 = (mod_name1 `stableModuleNameCmp` mod_name2)
1525 (is_boot1 `compare` is_boot2)
1527 pprModGuts :: ModGuts -> SDoc
1528 pprModGuts (ModGuts { mg_types = type_env,
1530 = vcat [ ppr_types [] type_env,
1533 ppr_types :: [Instance] -> TypeEnv -> SDoc
1534 ppr_types insts type_env
1535 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1537 dfun_ids = map instanceDFunId insts
1538 ids = [id | id <- typeEnvIds type_env, want_sig id]
1539 want_sig id | opt_PprStyle_Debug = True
1540 | otherwise = isLocalId id &&
1541 isExternalName (idName id) &&
1542 not (id `elem` dfun_ids)
1543 -- isLocalId ignores data constructors, records selectors etc.
1544 -- The isExternalName ignores local dictionary and method bindings
1545 -- that the type checker has invented. Top-level user-defined things
1546 -- have External names.
1548 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1549 ppr_tycons fam_insts type_env
1550 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1552 fi_tycons = map famInstTyCon fam_insts
1553 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1554 want_tycon tycon | opt_PprStyle_Debug = True
1555 | otherwise = not (isImplicitTyCon tycon) &&
1556 isExternalName (tyConName tycon) &&
1557 not (tycon `elem` fi_tycons)
1559 ppr_insts :: [Instance] -> SDoc
1560 ppr_insts [] = empty
1561 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1563 ppr_fam_insts :: [FamInst] -> SDoc
1564 ppr_fam_insts [] = empty
1565 ppr_fam_insts fam_insts =
1566 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1568 ppr_sigs :: [Var] -> SDoc
1570 -- Print type signatures; sort by OccName
1571 = vcat (map ppr_sig (sortLe le_sig ids))
1573 le_sig id1 id2 = getOccName id1 <= getOccName id2
1574 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1576 ppr_tydecls :: [TyCon] -> SDoc
1578 -- Print type constructor info; sort by OccName
1579 = vcat (map ppr_tycon (sortLe le_sig tycons))
1581 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1583 | isCoercionTyCon tycon = ptext (sLit "coercion") <+> ppr tycon
1584 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1586 ppr_rules :: [CoreRule] -> SDoc
1587 ppr_rules [] = empty
1588 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1589 nest 4 (pprRules rs),
1592 ppr_gen_tycons [] = empty
1593 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1594 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]