2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
5 \section[TcModule]{Typechecking a whole module}
9 -- The above warning supression flag is a temporary kludge.
10 -- While working on this module you are encouraged to remove it and fix
11 -- any warnings in the module. See
12 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
17 tcRnStmt, tcRnExpr, tcRnType,
30 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
60 import TcUnify ( withBox )
87 import Data.List ( sortBy )
99 import {- Kind parts of -} Type
101 import Foreign.Ptr( Ptr )
102 import TidyPgm ( globaliseAndTidyId )
111 import Data.Maybe ( isJust )
113 #include "HsVersions.h"
116 %************************************************************************
118 Typecheck and rename a module
120 %************************************************************************
126 -> Bool -- True <=> save renamed syntax
127 -> Located (HsModule RdrName)
128 -> IO (Messages, Maybe TcGblEnv)
130 tcRnModule hsc_env hsc_src save_rn_syntax
131 (L loc (HsModule maybe_mod export_ies
132 import_decls local_decls mod_deprec
134 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
136 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
137 this_mod = case maybe_mod of
138 Nothing -> mAIN -- 'module M where' is omitted
139 Just (L _ mod) -> mkModule this_pkg mod } ;
142 initTc hsc_env hsc_src save_rn_syntax this_mod $
144 do { -- Deal with imports;
145 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
146 setGblEnv tcg_env $ do {
148 -- Load the hi-boot interface for this module, if any
149 -- We do this now so that the boot_names can be passed
150 -- to tcTyAndClassDecls, because the boot_names are
151 -- automatically considered to be loop breakers
153 -- Do this *after* tcRnImports, so that we know whether
154 -- a module that we import imports us; and hence whether to
155 -- look for a hi-boot file
156 boot_iface <- tcHiBootIface hsc_src this_mod ;
158 -- Rename and type check the declarations
159 traceRn (text "rn1a") ;
160 tcg_env <- if isHsBoot hsc_src then
161 tcRnHsBootDecls local_decls
163 tcRnSrcDecls boot_iface local_decls ;
164 setGblEnv tcg_env $ do {
166 -- Report the use of any deprecated things
167 -- We do this *before* processsing the export list so
168 -- that we don't bleat about re-exporting a deprecated
169 -- thing (especially via 'module Foo' export item)
170 -- That is, only uses in the *body* of the module are complained about
171 traceRn (text "rn3") ;
172 failIfErrsM ; -- finishWarnings crashes sometimes
173 -- as a result of typechecker repairs (e.g. unboundNames)
174 tcg_env <- finishWarnings (hsc_dflags hsc_env) mod_deprec tcg_env ;
176 -- Process the export list
177 traceRn (text "rn4a: before exports");
178 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
179 traceRn (text "rn4b: after exportss") ;
181 -- Compare the hi-boot iface (if any) with the real thing
182 -- Must be done after processing the exports
183 tcg_env <- checkHiBootIface tcg_env boot_iface ;
185 -- The new type env is already available to stuff slurped from
186 -- interface files, via TcEnv.updateGlobalTypeEnv
187 -- It's important that this includes the stuff in checkHiBootIface,
188 -- because the latter might add new bindings for boot_dfuns,
189 -- which may be mentioned in imported unfoldings
191 -- Don't need to rename the Haddock documentation,
192 -- it's not parsed by GHC anymore.
193 tcg_env <- return (tcg_env { tcg_doc_hdr = maybe_doc_hdr }) ;
195 -- Report unused names
196 reportUnusedNames export_ies tcg_env ;
198 -- Dump output and return
205 %************************************************************************
209 %************************************************************************
212 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
213 tcRnImports hsc_env this_mod import_decls
214 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
216 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
217 ; dep_mods = imp_dep_mods imports
219 -- We want instance declarations from all home-package
220 -- modules below this one, including boot modules, except
221 -- ourselves. The 'except ourselves' is so that we don't
222 -- get the instances from this module's hs-boot file
223 ; want_instances :: ModuleName -> Bool
224 ; want_instances mod = mod `elemUFM` dep_mods
225 && mod /= moduleName this_mod
226 ; (home_insts, home_fam_insts) = hptInstances hsc_env
230 -- Record boot-file info in the EPS, so that it's
231 -- visible to loadHiBootInterface in tcRnSrcDecls,
232 -- and any other incrementally-performed imports
233 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
235 -- Update the gbl env
236 ; updGblEnv ( \ gbl ->
238 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
239 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
240 tcg_rn_imports = rn_imports,
241 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
242 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
247 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
248 -- Fail if there are any errors so far
249 -- The error printing (if needed) takes advantage
250 -- of the tcg_env we have now set
251 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
254 -- Load any orphan-module and family instance-module
255 -- interfaces, so that their rules and instance decls will be
257 ; loadOrphanModules (imp_orphs imports) False
258 ; loadOrphanModules (imp_finsts imports) True
260 -- Check type-familily consistency
261 ; traceRn (text "rn1: checking family instance consistency")
262 ; let { dir_imp_mods = moduleEnvKeys
265 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
271 %************************************************************************
273 Type-checking external-core modules
275 %************************************************************************
278 tcRnExtCore :: HscEnv
280 -> IO (Messages, Maybe ModGuts)
281 -- Nothing => some error occurred
283 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
284 -- The decls are IfaceDecls; all names are original names
285 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
287 initTc hsc_env ExtCoreFile False this_mod $ do {
289 let { ldecls = map noLoc decls } ;
291 -- bring the type and class decls into scope
292 -- ToDo: check that this doesn't need to extract the val binds.
293 -- It seems that only the type and class decls need to be in scope below because
294 -- (a) tcTyAndClassDecls doesn't need the val binds, and
295 -- (b) tcExtCoreBindings doesn't need anything
296 -- (in fact, it might not even need to be in the scope of
297 -- this tcg_env at all)
298 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
299 tc_envs <- extendGlobalRdrEnvRn avails emptyFsEnv {- no fixity decls -} ;
301 setEnvs tc_envs $ do {
303 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
305 -- Dump trace of renaming part
306 rnDump (ppr rn_decls) ;
308 -- Typecheck them all together so that
309 -- any mutually recursive types are done right
310 -- Just discard the auxiliary bindings; they are generated
311 -- only for Haskell source code, and should already be in Core
312 (tcg_env, _aux_binds) <- tcTyAndClassDecls emptyModDetails rn_decls ;
314 setGblEnv tcg_env $ do {
315 -- Make the new type env available to stuff slurped from interface files
317 -- Now the core bindings
318 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
322 bndrs = bindersOfBinds core_binds ;
323 my_exports = map (Avail . idName) bndrs ;
324 -- ToDo: export the data types also?
327 extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
329 mod_guts = ModGuts { mg_module = this_mod,
331 mg_used_names = emptyNameSet, -- ToDo: compute usage
332 mg_dir_imps = emptyModuleEnv, -- ??
333 mg_deps = noDependencies, -- ??
334 mg_exports = my_exports,
335 mg_types = final_type_env,
336 mg_insts = tcg_insts tcg_env,
337 mg_fam_insts = tcg_fam_insts tcg_env,
338 mg_inst_env = tcg_inst_env tcg_env,
339 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
341 mg_binds = core_binds,
344 mg_rdr_env = emptyGlobalRdrEnv,
345 mg_fix_env = emptyFixityEnv,
346 mg_warns = NoWarnings,
347 mg_foreign = NoStubs,
348 mg_hpc_info = emptyHpcInfo False,
349 mg_modBreaks = emptyModBreaks,
350 mg_vect_info = noVectInfo
353 tcCoreDump mod_guts ;
358 mkFakeGroup decls -- Rather clumsy; lots of unused fields
359 = emptyRdrGroup { hs_tyclds = decls }
363 %************************************************************************
365 Type-checking the top level of a module
367 %************************************************************************
370 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
371 -- Returns the variables free in the decls
372 -- Reason: solely to report unused imports and bindings
373 tcRnSrcDecls boot_iface decls
374 = do { -- Do all the declarations
375 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
377 -- Finish simplifying class constraints
379 -- tcSimplifyTop deals with constant or ambiguous InstIds.
380 -- How could there be ambiguous ones? They can only arise if a
381 -- top-level decl falls under the monomorphism restriction
382 -- and no subsequent decl instantiates its type.
384 -- We do this after checkMain, so that we use the type info
385 -- thaat checkMain adds
387 -- We do it with both global and local env in scope:
388 -- * the global env exposes the instances to tcSimplifyTop
389 -- * the local env exposes the local Ids to tcSimplifyTop,
390 -- so that we get better error messages (monomorphism restriction)
391 traceTc (text "Tc8") ;
392 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
394 -- Backsubstitution. This must be done last.
395 -- Even tcSimplifyTop may do some unification.
396 traceTc (text "Tc9") ;
397 let { (tcg_env, _) = tc_envs
398 ; TcGblEnv { tcg_type_env = type_env,
401 tcg_fords = fords } = tcg_env
402 ; all_binds = binds `unionBags` inst_binds } ;
404 failIfErrsM ; -- Don't zonk if there have been errors
405 -- It's a waste of time; and we may get debug warnings
406 -- about strangely-typed TyCons!
408 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
411 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
412 ; tcg_env' = tcg_env { tcg_binds = binds',
414 tcg_fords = fords' } } ;
416 setGlobalTypeEnv tcg_env' final_type_env
419 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
420 -- Loops around dealing with each top level inter-splice group
421 -- in turn, until it's dealt with the entire module
422 tc_rn_src_decls boot_details ds
423 = do { let { (first_group, group_tail) = findSplice ds } ;
424 -- If ds is [] we get ([], Nothing)
426 -- Deal with decls up to, but not including, the first splice
427 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
428 -- rnTopSrcDecls fails if there are any errors
430 (tcg_env, tcl_env) <- setGblEnv tcg_env $
431 tcTopSrcDecls boot_details rn_decls ;
433 -- If there is no splice, we're nearly done
434 setEnvs (tcg_env, tcl_env) $
436 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
437 return (tcg_env, tcl_env)
440 -- If there's a splice, we must carry on
441 Just (SpliceDecl splice_expr, rest_ds) -> do {
443 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
446 -- Rename the splice expression, and get its supporting decls
447 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
448 -- checkNoErrs: don't typecheck if renaming failed
449 rnDump (ppr rn_splice_expr) ;
451 -- Execute the splice
452 spliced_decls <- tcSpliceDecls rn_splice_expr ;
454 -- Glue them on the front of the remaining decls and loop
455 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
456 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
461 %************************************************************************
463 Compiling hs-boot source files, and
464 comparing the hi-boot interface with the real thing
466 %************************************************************************
469 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
470 tcRnHsBootDecls decls
471 = do { let { (first_group, group_tail) = findSplice decls }
474 Just stuff -> spliceInHsBootErr stuff
477 -- Rename the declarations
478 ; (tcg_env, HsGroup {
479 hs_tyclds = tycl_decls,
480 hs_instds = inst_decls,
481 hs_derivds = deriv_decls,
483 hs_defds = _, -- Todo: check no foreign decls, no rules,
484 hs_ruleds = _, -- no default decls and no annotation decls
486 hs_valds = val_binds }) <- rnTopSrcDecls first_group
487 ; setGblEnv tcg_env $ do {
490 -- Typecheck type/class decls
491 ; traceTc (text "Tc2")
492 ; (tcg_env, aux_binds) <- tcTyAndClassDecls emptyModDetails tycl_decls
493 ; setGblEnv tcg_env $ do {
495 -- Typecheck instance decls
496 ; traceTc (text "Tc3")
497 ; (tcg_env, inst_infos, _deriv_binds)
498 <- tcInstDecls1 tycl_decls inst_decls deriv_decls
499 ; setGblEnv tcg_env $ do {
501 -- Typecheck value declarations
502 ; traceTc (text "Tc5")
503 ; val_ids <- tcHsBootSigs val_binds
506 -- No simplification or zonking to do
507 ; traceTc (text "Tc7a")
508 ; gbl_env <- getGblEnv
510 -- Make the final type-env
511 -- Include the dfun_ids so that their type sigs
512 -- are written into the interface file.
513 -- And similarly the aux_ids from aux_binds
514 ; let { type_env0 = tcg_type_env gbl_env
515 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
516 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
517 ; type_env3 = extendTypeEnvWithIds type_env1 aux_ids
518 ; dfun_ids = map iDFunId inst_infos
519 ; aux_ids = case aux_binds of
520 ValBindsOut _ sigs -> [id | L _ (IdSig id) <- sigs]
521 _ -> panic "tcRnHsBoodDecls"
524 ; setGlobalTypeEnv gbl_env type_env2
527 spliceInHsBootErr (SpliceDecl (L loc _), _)
528 = addErrAt loc (ptext (sLit "Splices are not allowed in hs-boot files"))
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, tcg_fam_insts = local_fam_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 instance declarations
561 ; mb_dfun_prs <- mapM check_inst boot_insts
562 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds,
563 tcg_type_env = extendTypeEnvWithIds local_type_env boot_dfuns }
564 dfun_prs = catMaybes mb_dfun_prs
565 boot_dfuns = map fst dfun_prs
566 dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun)
567 | (boot_dfun, dfun) <- dfun_prs ]
569 -- Check for no family instances
570 ; unless (null boot_fam_insts) $
571 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
572 "instances in boot files yet...")
573 -- FIXME: Why? The actual comparison is not hard, but what would
574 -- be the equivalent to the dfun bindings returned for class
575 -- instances? We can't easily equate tycons...
577 -- Check instance declarations
578 ; mb_dfun_prs <- mapM check_inst boot_insts
579 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
580 final_type_env = extendTypeEnvWithIds local_type_env boot_dfuns
581 dfun_prs = catMaybes mb_dfun_prs
582 boot_dfuns = map fst dfun_prs
583 dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun)
584 | (boot_dfun, dfun) <- dfun_prs ]
587 ; setGlobalTypeEnv tcg_env' final_type_env }
589 check_export boot_avail -- boot_avail is exported by the boot iface
590 | name `elem` dfun_names = return ()
591 | isWiredInName name = return () -- No checking for wired-in names. In particular,
592 -- 'error' is handled by a rather gross hack
593 -- (see comments in GHC.Err.hs-boot)
595 -- Check that the actual module exports the same thing
596 | not (null missing_names)
597 = addErrAt (nameSrcSpan (head missing_names))
598 (missingBootThing (head missing_names) "exported by")
600 -- If the boot module does not *define* the thing, we are done
601 -- (it simply re-exports it, and names match, so nothing further to do)
602 | isNothing mb_boot_thing = return ()
604 -- Check that the actual module also defines the thing, and
605 -- then compare the definitions
606 | Just real_thing <- lookupTypeEnv local_type_env name,
607 Just boot_thing <- mb_boot_thing
608 = when (not (checkBootDecl boot_thing real_thing))
609 $ addErrAt (nameSrcSpan (getName boot_thing))
610 (let boot_decl = tyThingToIfaceDecl
611 (fromJust mb_boot_thing)
612 real_decl = tyThingToIfaceDecl real_thing
613 in bootMisMatch real_thing boot_decl real_decl)
616 = addErrTc (missingBootThing name "defined in")
618 name = availName boot_avail
619 mb_boot_thing = lookupTypeEnv boot_type_env name
620 missing_names = case lookupNameEnv local_export_env name of
622 Just avail -> availNames boot_avail `minusList` availNames avail
624 dfun_names = map getName boot_insts
626 local_export_env :: NameEnv AvailInfo
627 local_export_env = availsToNameEnv local_exports
629 check_inst :: Instance -> TcM (Maybe (Id, Id))
630 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
632 = case [dfun | inst <- local_insts,
633 let dfun = instanceDFunId inst,
634 idType dfun `tcEqType` boot_inst_ty ] of
635 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
636 (dfun:_) -> return (Just (local_boot_dfun, dfun))
638 boot_dfun = instanceDFunId boot_inst
639 boot_inst_ty = idType boot_dfun
640 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
643 -- This has to compare the TyThing from the .hi-boot file to the TyThing
644 -- in the current source file. We must be careful to allow alpha-renaming
645 -- where appropriate, and also the boot declaration is allowed to omit
646 -- constructors and class methods.
648 -- See rnfail055 for a good test of this stuff.
650 checkBootDecl :: TyThing -> TyThing -> Bool
652 checkBootDecl (AnId id1) (AnId id2)
654 (idType id1 `tcEqType` idType id2)
656 checkBootDecl (ATyCon tc1) (ATyCon tc2)
657 = checkBootTyCon tc1 tc2
659 checkBootDecl (AClass c1) (AClass c2)
661 (clas_tyvars1, clas_fds1, sc_theta1, _, ats1, op_stuff1)
662 = classExtraBigSig c1
663 (clas_tyvars2, clas_fds2, sc_theta2, _, ats2, op_stuff2)
664 = classExtraBigSig c2
666 env0 = mkRnEnv2 emptyInScopeSet
667 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
669 eqSig (id1, def_meth1) (id2, def_meth2)
670 = idName id1 == idName id2 &&
671 tcEqTypeX env op_ty1 op_ty2
673 (_, rho_ty1) = splitForAllTys (idType id1)
674 op_ty1 = funResultTy rho_ty1
675 (_, rho_ty2) = splitForAllTys (idType id2)
676 op_ty2 = funResultTy rho_ty2
678 eqFD (as1,bs1) (as2,bs2) =
679 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
680 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
682 same_kind tv1 tv2 = eqKind (tyVarKind tv1) (tyVarKind tv2)
684 eqListBy same_kind clas_tyvars1 clas_tyvars2 &&
685 -- Checks kind of class
686 eqListBy eqFD clas_fds1 clas_fds2 &&
687 (null sc_theta1 && null op_stuff1 && null ats1
688 || -- Above tests for an "abstract" class
689 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
690 eqListBy eqSig op_stuff1 op_stuff2 &&
691 eqListBy checkBootTyCon ats1 ats2)
693 checkBootDecl (ADataCon dc1) (ADataCon dc2)
694 = pprPanic "checkBootDecl" (ppr dc1)
696 checkBootDecl _ _ = False -- probably shouldn't happen
699 checkBootTyCon :: TyCon -> TyCon -> Bool
700 checkBootTyCon tc1 tc2
701 | not (eqKind (tyConKind tc1) (tyConKind tc2))
702 = False -- First off, check the kind
704 | isSynTyCon tc1 && isSynTyCon tc2
706 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
707 env = rnBndrs2 env0 tvs1 tvs2
709 eqSynRhs (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
710 = tcEqTypeX env k1 k2
711 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
712 = tcEqTypeX env t1 t2
714 equalLength tvs1 tvs2 &&
715 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
717 | isAlgTyCon tc1 && isAlgTyCon tc2
719 eqKind (tyConKind tc1) (tyConKind tc2) &&
720 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2) &&
721 eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
723 | isForeignTyCon tc1 && isForeignTyCon tc2
724 = eqKind (tyConKind tc1) (tyConKind tc2) &&
725 tyConExtName tc1 == tyConExtName tc2
727 env0 = mkRnEnv2 emptyInScopeSet
729 eqAlgRhs AbstractTyCon _ = True
730 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
731 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
732 eqListBy eqCon (data_cons tc1) (data_cons tc2)
733 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
734 eqCon (data_con tc1) (data_con tc2)
738 = dataConName c1 == dataConName c2
739 && dataConIsInfix c1 == dataConIsInfix c2
740 && dataConStrictMarks c1 == dataConStrictMarks c2
741 && dataConFieldLabels c1 == dataConFieldLabels c2
742 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
743 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
744 env = rnBndrs2 env0 tvs1 tvs2
746 equalLength tvs1 tvs2 &&
747 eqListBy (tcEqPredX env)
748 (dataConEqTheta c1 ++ dataConDictTheta c1)
749 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
750 eqListBy (tcEqTypeX env)
751 (dataConOrigArgTys c1)
752 (dataConOrigArgTys c2)
755 missingBootThing thing what
756 = ppr thing <+> ptext (sLit "is exported by the hs-boot file, but not")
757 <+> text what <+> ptext (sLit "the module")
759 bootMisMatch thing boot_decl real_decl
760 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
761 ptext (sLit "Main module:") <+> ppr real_decl,
762 ptext (sLit "Boot file: ") <+> ppr boot_decl]
766 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
770 %************************************************************************
772 Type-checking the top level of a module
774 %************************************************************************
776 tcRnGroup takes a bunch of top-level source-code declarations, and
778 * gets supporting declarations from interface files
781 * and augments the TcGblEnv with the results
783 In Template Haskell it may be called repeatedly for each group of
784 declarations. It expects there to be an incoming TcGblEnv in the
785 monad; it augments it and returns the new TcGblEnv.
788 ------------------------------------------------
789 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
790 -- Fails if there are any errors
792 = do { -- Rename the source decls
793 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
795 -- save the renamed syntax, if we want it
797 | Just grp <- tcg_rn_decls tcg_env
798 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
802 -- Dump trace of renaming part
803 rnDump (ppr rn_decls) ;
805 return (tcg_env', rn_decls)
808 ------------------------------------------------
809 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
810 tcTopSrcDecls boot_details
811 (HsGroup { hs_tyclds = tycl_decls,
812 hs_instds = inst_decls,
813 hs_derivds = deriv_decls,
814 hs_fords = foreign_decls,
815 hs_defds = default_decls,
816 hs_annds = annotation_decls,
817 hs_ruleds = rule_decls,
818 hs_valds = val_binds })
819 = do { -- Type-check the type and class decls, and all imported decls
820 -- The latter come in via tycl_decls
821 traceTc (text "Tc2") ;
823 (tcg_env, aux_binds) <- tcTyAndClassDecls boot_details tycl_decls ;
824 -- If there are any errors, tcTyAndClassDecls fails here
826 setGblEnv tcg_env $ do {
827 -- Source-language instances, including derivings,
828 -- and import the supporting declarations
829 traceTc (text "Tc3") ;
830 (tcg_env, inst_infos, deriv_binds)
831 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
832 setGblEnv tcg_env $ do {
834 -- Foreign import declarations next.
835 traceTc (text "Tc4") ;
836 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
837 tcExtendGlobalValEnv fi_ids $ do {
839 -- Default declarations
840 traceTc (text "Tc4a") ;
841 default_tys <- tcDefaults default_decls ;
842 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
844 -- Now GHC-generated derived bindings, generics, and selectors
845 -- Do not generate warnings from compiler-generated code;
846 -- hence the use of discardWarnings
847 (tc_aux_binds, tcl_env) <- discardWarnings (tcTopBinds aux_binds) ;
848 (tc_deriv_binds, tcl_env) <- setLclTypeEnv tcl_env $
849 discardWarnings (tcTopBinds deriv_binds) ;
851 -- Value declarations next
852 traceTc (text "Tc5") ;
853 (tc_val_binds, tcl_env) <- setLclTypeEnv tcl_env $
854 tcTopBinds val_binds;
856 -- Second pass over class and instance declarations,
857 traceTc (text "Tc6") ;
858 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $
859 tcInstDecls2 tycl_decls inst_infos ;
860 showLIE (text "after instDecls2") ;
862 setLclTypeEnv tcl_env $ do { -- Environment doesn't change now
865 traceTc (text "Tc7") ;
866 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
869 annotations <- tcAnnotations annotation_decls ;
872 rules <- tcRules rule_decls ;
875 traceTc (text "Tc7a") ;
876 tcg_env <- getGblEnv ;
877 let { all_binds = tc_val_binds `unionBags`
878 tc_deriv_binds `unionBags`
879 tc_aux_binds `unionBags`
880 inst_binds `unionBags`
883 -- Extend the GblEnv with the (as yet un-zonked)
884 -- bindings, rules, foreign decls
885 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
886 tcg_rules = tcg_rules tcg_env ++ rules,
887 tcg_anns = tcg_anns tcg_env ++ annotations,
888 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
889 return (tcg_env', tcl_env)
894 %************************************************************************
898 %************************************************************************
901 checkMain :: TcM TcGblEnv
902 -- If we are in module Main, check that 'main' is defined.
904 = do { tcg_env <- getGblEnv ;
906 check_main dflags tcg_env
909 check_main dflags tcg_env
911 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
915 = do { mb_main <- lookupGlobalOccRn_maybe main_fn
916 -- Check that 'main' is in scope
917 -- It might be imported from another module!
919 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
924 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
925 ; let loc = srcLocSpan (getSrcLoc main_name)
926 ; ioTyCon <- tcLookupTyCon ioTyConName
927 ; (main_expr, res_ty)
928 <- addErrCtxt mainCtxt $
929 withBox liftedTypeKind $ \res_ty ->
930 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
932 -- See Note [Root-main Id]
933 -- Construct the binding
934 -- :Main.main :: IO res_ty = runMainIO res_ty main
935 ; run_main_id <- tcLookupId runMainIOName
936 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
937 (mkVarOccFS (fsLit "main"))
938 (getSrcSpan main_name)
939 ; root_main_id = Id.mkExportedLocalId root_main_name
940 (mkTyConApp ioTyCon [res_ty])
941 ; co = mkWpTyApps [res_ty]
942 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
943 ; main_bind = mkVarBind root_main_id rhs }
945 ; return (tcg_env { 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 | main_fn == main_RDR_Unqual = ptext (sLit "function") <+> quotes (ppr main_fn)
968 | otherwise = ptext (sLit "main function") <+> quotes (ppr main_fn)
970 -- | Get the unqualified name of the function to use as the \"main\" for the main module.
971 -- Either returns the default name or the one configured on the command line with -main-is
972 getMainFun :: DynFlags -> RdrName
973 getMainFun dflags = case (mainFunIs dflags) of
974 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
975 Nothing -> main_RDR_Unqual
980 The function that the RTS invokes is always :Main.main, which we call
981 root_main_id. (Because GHC allows the user to have a module not
982 called Main as the main module, we can't rely on the main function
983 being called "Main.main". That's why root_main_id has a fixed module
986 This is unusual: it's a LocalId whose Name has a Module from another
987 module. Tiresomely, we must filter it out again in MkIface, les we
988 get two defns for 'main' in the interface file!
991 %*********************************************************
995 %*********************************************************
999 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
1000 setInteractiveContext hsc_env icxt thing_inside
1001 = let -- Initialise the tcg_inst_env with instances from all home modules.
1002 -- This mimics the more selective call to hptInstances in tcRnModule.
1003 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
1005 updGblEnv (\env -> env {
1006 tcg_rdr_env = ic_rn_gbl_env icxt,
1007 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
1008 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
1012 tcExtendGhciEnv (ic_tmp_ids icxt) $
1013 -- tcExtendGhciEnv does lots:
1014 -- - it extends the local type env (tcl_env) with the given Ids,
1015 -- - it extends the local rdr env (tcl_rdr) with the Names from
1017 -- - it adds the free tyvars of the Ids to the tcl_tyvars
1020 -- later ids in ic_tmp_ids must shadow earlier ones with the same
1021 -- OccName, and tcExtendIdEnv implements this behaviour.
1023 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
1030 -> InteractiveContext
1032 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1033 -- The returned [Id] is the list of new Ids bound by
1034 -- this statement. It can be used to extend the
1035 -- InteractiveContext via extendInteractiveContext.
1037 -- The returned TypecheckedHsExpr is of type IO [ () ],
1038 -- a list of the bound values, coerced to ().
1040 tcRnStmt hsc_env ictxt rdr_stmt
1041 = initTcPrintErrors hsc_env iNTERACTIVE $
1042 setInteractiveContext hsc_env ictxt $ do {
1044 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1045 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
1046 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1048 rnDump (ppr rn_stmt) ;
1050 -- The real work is done here
1051 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1052 zonked_expr <- zonkTopLExpr tc_expr ;
1053 zonked_ids <- zonkTopBndrs bound_ids ;
1055 -- None of the Ids should be of unboxed type, because we
1056 -- cast them all to HValues in the end!
1057 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1059 traceTc (text "tcs 1") ;
1060 let { global_ids = map globaliseAndTidyId zonked_ids } ;
1061 -- Note [Interactively-bound Ids in GHCi]
1063 {- ---------------------------------------------
1064 At one stage I removed any shadowed bindings from the type_env;
1065 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1066 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1068 Prelude> let f n = n * 2 :: Int
1069 Prelude> fName <- runQ [| f |]
1070 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1072 Prelude> let f n = n * 3 :: Int
1073 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1074 In the last line we use 'fName', which resolves to the *first* 'f'
1075 in scope. If we delete it from the type env, GHCi crashes because
1076 it doesn't expect that.
1078 Hence this code is commented out
1080 -------------------------------------------------- -}
1082 dumpOptTcRn Opt_D_dump_tc
1083 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1084 text "Typechecked expr" <+> ppr zonked_expr]) ;
1086 return (global_ids, zonked_expr)
1089 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1090 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1093 Note [Interactively-bound Ids in GHCi]
1094 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1095 The Ids bound by previous Stmts in Template Haskell are currently
1097 b) with an Internal Name (not External)
1098 c) and a tidied type
1100 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1101 compile an expression using these ids later, the byte code
1102 generator will consider the occurrences to be free rather than
1105 (b) They retain their Internal names becuase we don't have a suitable
1106 Module to name them with. We could revisit this choice.
1108 (c) Their types are tidied. This is important, because :info may ask
1109 to look at them, and :info expects the things it looks up to have
1113 --------------------------------------------------------------------------
1114 Typechecking Stmts in GHCi
1116 Here is the grand plan, implemented in tcUserStmt
1118 What you type The IO [HValue] that hscStmt returns
1119 ------------- ------------------------------------
1120 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1123 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1126 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1127 [NB: result not printed] bindings: [it]
1129 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1130 result showable) bindings: [it]
1132 expr (of non-IO type,
1133 result not showable) ==> error
1137 ---------------------------
1138 type PlanResult = ([Id], LHsExpr Id)
1139 type Plan = TcM PlanResult
1141 runPlans :: [Plan] -> TcM PlanResult
1142 -- Try the plans in order. If one fails (by raising an exn), try the next.
1143 -- If one succeeds, take it.
1144 runPlans [] = panic "runPlans"
1146 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1148 --------------------
1149 mkPlan :: LStmt Name -> TcM PlanResult
1150 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1151 = do { uniq <- newUnique -- is treated very specially
1152 ; let fresh_it = itName uniq
1153 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1154 matches = [mkMatch [] expr emptyLocalBinds]
1155 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1156 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1157 (HsVar bindIOName) noSyntaxExpr
1158 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1159 (HsVar thenIOName) placeHolderType
1162 -- [it <- e; print it] but not if it::()
1164 -- [let it = e; print it]
1165 ; runPlans [ -- Plan A
1166 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1167 ; it_ty <- zonkTcType (idType it_id)
1168 ; when (isUnitTy it_ty) failM
1171 -- Plan B; a naked bind statment
1172 tcGhciStmts [bind_stmt],
1174 -- Plan C; check that the let-binding is typeable all by itself.
1175 -- If not, fail; if so, try to print it.
1176 -- The two-step process avoids getting two errors: one from
1177 -- the expression itself, and one from the 'print it' part
1178 -- This two-step story is very clunky, alas
1179 do { checkNoErrs (tcGhciStmts [let_stmt])
1180 --- checkNoErrs defeats the error recovery of let-bindings
1181 ; tcGhciStmts [let_stmt, print_it] }
1184 mkPlan stmt@(L loc (BindStmt {}))
1185 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1186 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1187 (HsVar thenIOName) placeHolderType
1189 ; print_bind_result <- doptM Opt_PrintBindResult
1190 ; let print_plan = do
1191 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1192 ; v_ty <- zonkTcType (idType v_id)
1193 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1197 -- [stmt; print v] but not if v::()
1199 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1200 [tcGhciStmts [stmt]])
1204 = tcGhciStmts [stmt]
1206 ---------------------------
1207 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1209 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1210 ret_id <- tcLookupId returnIOName ; -- return @ IO
1212 ret_ty = mkListTy unitTy ;
1213 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1214 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1216 names = map unLoc (collectLStmtsBinders stmts) ;
1218 -- mk_return builds the expression
1219 -- returnIO @ [()] [coerce () x, .., coerce () z]
1221 -- Despite the inconvenience of building the type applications etc,
1222 -- this *has* to be done in type-annotated post-typecheck form
1223 -- because we are going to return a list of *polymorphic* values
1224 -- coerced to type (). If we built a *source* stmt
1225 -- return [coerce x, ..., coerce z]
1226 -- then the type checker would instantiate x..z, and we wouldn't
1227 -- get their *polymorphic* values. (And we'd get ambiguity errs
1228 -- if they were overloaded, since they aren't applied to anything.)
1229 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1230 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1231 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1235 -- OK, we're ready to typecheck the stmts
1236 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1237 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1238 mapM tcLookupId names ;
1239 -- Look up the names right in the middle,
1240 -- where they will all be in scope
1242 -- Simplify the context
1243 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1244 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1245 -- checkNoErrs ensures that the plan fails if context redn fails
1247 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1248 return (ids, mkHsDictLet const_binds $
1249 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1254 tcRnExpr just finds the type of an expression
1258 -> InteractiveContext
1260 -> IO (Messages, Maybe Type)
1261 tcRnExpr hsc_env ictxt rdr_expr
1262 = initTcPrintErrors hsc_env iNTERACTIVE $
1263 setInteractiveContext hsc_env ictxt $ do {
1265 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1268 -- Now typecheck the expression;
1269 -- it might have a rank-2 type (e.g. :t runST)
1270 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1271 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1272 tcSimplifyInteractive lie_top ;
1274 let { all_expr_ty = mkForAllTys qtvs $
1275 mkFunTys (map (idType . instToId) dict_insts) $
1277 zonkTcType all_expr_ty
1280 smpl_doc = ptext (sLit "main expression")
1283 tcRnType just finds the kind of a type
1287 -> InteractiveContext
1289 -> IO (Messages, Maybe Kind)
1290 tcRnType hsc_env ictxt rdr_type
1291 = initTcPrintErrors hsc_env iNTERACTIVE $
1292 setInteractiveContext hsc_env ictxt $ do {
1294 rn_type <- rnLHsType doc rdr_type ;
1297 -- Now kind-check the type
1298 (ty', kind) <- kcLHsType rn_type ;
1302 doc = ptext (sLit "In GHCi input")
1308 %************************************************************************
1310 More GHCi stuff, to do with browsing and getting info
1312 %************************************************************************
1316 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1317 -- a package module with an interface on disk. If neither of these is
1318 -- true, then the result will be an error indicating the interface
1319 -- could not be found.
1320 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1321 getModuleExports hsc_env mod
1324 checkMods = ic_toplev_scope ic ++ ic_exports ic
1326 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1328 -- Get the export avail info and also load all orphan and family-instance
1329 -- modules. Finally, check that the family instances of all modules in the
1330 -- interactive context are consistent (these modules are in the second
1332 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1333 tcGetModuleExports mod directlyImpMods
1334 = do { let doc = ptext (sLit "context for compiling statements")
1335 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1337 -- Load any orphan-module and family instance-module
1338 -- interfaces, so their instances are visible.
1339 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1340 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1342 -- Check that the family instances of all directly loaded
1343 -- modules are consistent.
1344 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1346 ; ifaceExportNames (mi_exports iface)
1349 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1350 tcRnLookupRdrName hsc_env rdr_name
1351 = initTcPrintErrors hsc_env iNTERACTIVE $
1352 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1353 lookup_rdr_name rdr_name
1355 lookup_rdr_name rdr_name = do {
1356 -- If the identifier is a constructor (begins with an
1357 -- upper-case letter), then we need to consider both
1358 -- constructor and type class identifiers.
1359 let { rdr_names = dataTcOccs rdr_name } ;
1361 -- results :: [Either Messages Name]
1362 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1364 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1365 -- The successful lookups will be (Just name)
1366 let { (warns_s, good_names) = unzip [ (msgs, name)
1367 | (msgs, Just name) <- results] ;
1368 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1370 -- Fail if nothing good happened, else add warnings
1371 if null good_names then
1372 -- No lookup succeeded, so
1373 -- pick the first error message and report it
1374 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1375 -- while the other is "X is not in scope",
1376 -- we definitely want the former; but we might pick the latter
1377 do { addMessages (head errs_s) ; failM }
1378 else -- Add deprecation warnings
1379 mapM_ addMessages warns_s ;
1384 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1385 tcRnLookupName hsc_env name
1386 = initTcPrintErrors hsc_env iNTERACTIVE $
1387 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1388 tcRnLookupName' name
1390 -- To look up a name we have to look in the local environment (tcl_lcl)
1391 -- as well as the global environment, which is what tcLookup does.
1392 -- But we also want a TyThing, so we have to convert:
1394 tcRnLookupName' :: Name -> TcRn TyThing
1395 tcRnLookupName' name = do
1396 tcthing <- tcLookup name
1398 AGlobal thing -> return thing
1399 ATcId{tct_id=id} -> return (AnId id)
1400 _ -> panic "tcRnLookupName'"
1402 tcRnGetInfo :: HscEnv
1404 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1406 -- Used to implement :info in GHCi
1408 -- Look up a RdrName and return all the TyThings it might be
1409 -- A capitalised RdrName is given to us in the DataName namespace,
1410 -- but we want to treat it as *both* a data constructor
1411 -- *and* as a type or class constructor;
1412 -- hence the call to dataTcOccs, and we return up to two results
1413 tcRnGetInfo hsc_env name
1414 = initTcPrintErrors hsc_env iNTERACTIVE $
1415 let ictxt = hsc_IC hsc_env in
1416 setInteractiveContext hsc_env ictxt $ do
1418 -- Load the interface for all unqualified types and classes
1419 -- That way we will find all the instance declarations
1420 -- (Packages have not orphan modules, and we assume that
1421 -- in the home package all relevant modules are loaded.)
1422 loadUnqualIfaces ictxt
1424 thing <- tcRnLookupName' name
1425 fixity <- lookupFixityRn name
1426 ispecs <- lookupInsts thing
1427 return (thing, fixity, ispecs)
1429 lookupInsts :: TyThing -> TcM [Instance]
1430 lookupInsts (AClass cls)
1431 = do { inst_envs <- tcGetInstEnvs
1432 ; return (classInstances inst_envs cls) }
1434 lookupInsts (ATyCon tc)
1435 = do { eps <- getEps -- Load all instances for all classes that are
1436 -- in the type environment (which are all the ones
1437 -- we've seen in any interface file so far)
1438 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1440 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1441 , let dfun = instanceDFunId ispec
1444 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1445 tc_name = tyConName tc
1447 lookupInsts other = return []
1449 loadUnqualIfaces :: InteractiveContext -> TcM ()
1450 -- Load the home module for everything that is in scope unqualified
1451 -- This is so that we can accurately report the instances for
1453 loadUnqualIfaces ictxt
1455 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1457 unqual_mods = [ nameModule name
1458 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1459 let name = gre_name gre,
1460 not (isInternalName name),
1461 isTcOcc (nameOccName name), -- Types and classes only
1462 unQualOK gre ] -- In scope unqualified
1463 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1467 %************************************************************************
1471 %************************************************************************
1474 rnDump :: SDoc -> TcRn ()
1475 -- Dump, with a banner, if -ddump-rn
1476 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1478 tcDump :: TcGblEnv -> TcRn ()
1480 = do { dflags <- getDOpts ;
1482 -- Dump short output if -ddump-types or -ddump-tc
1483 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1484 (dumpTcRn short_dump) ;
1486 -- Dump bindings if -ddump-tc
1487 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1490 short_dump = pprTcGblEnv env
1491 full_dump = pprLHsBinds (tcg_binds env)
1492 -- NB: foreign x-d's have undefined's in their types;
1493 -- hence can't show the tc_fords
1496 = do { dflags <- getDOpts ;
1497 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1498 (dumpTcRn (pprModGuts mod_guts)) ;
1500 -- Dump bindings if -ddump-tc
1501 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1503 full_dump = pprCoreBindings (mg_binds mod_guts)
1505 -- It's unpleasant having both pprModGuts and pprModDetails here
1506 pprTcGblEnv :: TcGblEnv -> SDoc
1507 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1509 tcg_fam_insts = fam_insts,
1511 tcg_imports = imports })
1512 = vcat [ ppr_types insts type_env
1513 , ppr_tycons fam_insts type_env
1515 , ppr_fam_insts fam_insts
1516 , vcat (map ppr rules)
1517 , ppr_gen_tycons (typeEnvTyCons type_env)
1518 , ptext (sLit "Dependent modules:") <+>
1519 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1520 , ptext (sLit "Dependent packages:") <+>
1521 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1522 where -- The two uses of sortBy are just to reduce unnecessary
1523 -- wobbling in testsuite output
1524 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1525 = (mod_name1 `stableModuleNameCmp` mod_name2)
1527 (is_boot1 `compare` is_boot2)
1529 pprModGuts :: ModGuts -> SDoc
1530 pprModGuts (ModGuts { mg_types = type_env,
1532 = vcat [ ppr_types [] type_env,
1535 ppr_types :: [Instance] -> TypeEnv -> SDoc
1536 ppr_types insts type_env
1537 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1539 dfun_ids = map instanceDFunId insts
1540 ids = [id | id <- typeEnvIds type_env, want_sig id]
1541 want_sig id | opt_PprStyle_Debug = True
1542 | otherwise = isLocalId id &&
1543 isExternalName (idName id) &&
1544 not (id `elem` dfun_ids)
1545 -- isLocalId ignores data constructors, records selectors etc.
1546 -- The isExternalName ignores local dictionary and method bindings
1547 -- that the type checker has invented. Top-level user-defined things
1548 -- have External names.
1550 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1551 ppr_tycons fam_insts type_env
1552 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1554 fi_tycons = map famInstTyCon fam_insts
1555 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1556 want_tycon tycon | opt_PprStyle_Debug = True
1557 | otherwise = not (isImplicitTyCon tycon) &&
1558 isExternalName (tyConName tycon) &&
1559 not (tycon `elem` fi_tycons)
1561 ppr_insts :: [Instance] -> SDoc
1562 ppr_insts [] = empty
1563 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1565 ppr_fam_insts :: [FamInst] -> SDoc
1566 ppr_fam_insts [] = empty
1567 ppr_fam_insts fam_insts =
1568 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1570 ppr_sigs :: [Var] -> SDoc
1572 -- Print type signatures; sort by OccName
1573 = vcat (map ppr_sig (sortLe le_sig ids))
1575 le_sig id1 id2 = getOccName id1 <= getOccName id2
1576 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1578 ppr_tydecls :: [TyCon] -> SDoc
1580 -- Print type constructor info; sort by OccName
1581 = vcat (map ppr_tycon (sortLe le_sig tycons))
1583 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1585 | isCoercionTyCon tycon
1586 = sep [ptext (sLit "coercion") <+> ppr tycon <+> ppr tvs
1587 , nest 2 (dcolon <+> pprEqPred (coercionKind (mkTyConApp tycon (mkTyVarTys tvs))))]
1588 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1590 tvs = take (tyConArity tycon) alphaTyVars
1592 ppr_rules :: [CoreRule] -> SDoc
1593 ppr_rules [] = empty
1594 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1595 nest 4 (pprRules rs),
1598 ppr_gen_tycons [] = empty
1599 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1600 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]