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 )
86 import Data.List ( sortBy )
98 import {- Kind parts of -} Type
100 import Foreign.Ptr( Ptr )
101 import TidyPgm ( globaliseAndTidyId )
110 import Data.Maybe ( isJust )
112 #include "HsVersions.h"
117 %************************************************************************
119 Typecheck and rename a module
121 %************************************************************************
127 -> Bool -- True <=> save renamed syntax
128 -> Located (HsModule RdrName)
129 -> IO (Messages, Maybe TcGblEnv)
131 tcRnModule hsc_env hsc_src save_rn_syntax
132 (L loc (HsModule maybe_mod export_ies
133 import_decls local_decls mod_deprec
134 module_info maybe_doc))
135 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
137 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
138 this_mod = case maybe_mod of
139 Nothing -> mAIN -- 'module M where' is omitted
140 Just (L _ mod) -> mkModule this_pkg mod } ;
143 initTc hsc_env hsc_src save_rn_syntax this_mod $
145 do { -- Deal with imports;
146 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
147 setGblEnv tcg_env $ do {
149 -- Load the hi-boot interface for this module, if any
150 -- We do this now so that the boot_names can be passed
151 -- to tcTyAndClassDecls, because the boot_names are
152 -- automatically considered to be loop breakers
154 -- Do this *after* tcRnImports, so that we know whether
155 -- a module that we import imports us; and hence whether to
156 -- look for a hi-boot file
157 boot_iface <- tcHiBootIface hsc_src this_mod ;
159 -- Rename and type check the declarations
160 traceRn (text "rn1a") ;
161 tcg_env <- if isHsBoot hsc_src then
162 tcRnHsBootDecls local_decls
164 tcRnSrcDecls boot_iface local_decls ;
165 setGblEnv tcg_env $ do {
167 -- Report the use of any deprecated things
168 -- We do this *before* processsing the export list so
169 -- that we don't bleat about re-exporting a deprecated
170 -- thing (especially via 'module Foo' export item)
171 -- That is, only uses in the *body* of the module are complained about
172 traceRn (text "rn3") ;
173 failIfErrsM ; -- finishWarnings crashes sometimes
174 -- as a result of typechecker repairs (e.g. unboundNames)
175 tcg_env <- finishWarnings (hsc_dflags hsc_env) mod_deprec tcg_env ;
177 -- Process the export list
178 traceRn (text "rn4a: before exports");
179 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
180 traceRn (text "rn4b: after exportss") ;
182 -- Compare the hi-boot iface (if any) with the real thing
183 -- Must be done after processing the exports
184 tcg_env <- checkHiBootIface tcg_env boot_iface ;
186 -- The new type env is already available to stuff slurped from
187 -- interface files, via TcEnv.updateGlobalTypeEnv
188 -- It's important that this includes the stuff in checkHiBootIface,
189 -- because the latter might add new bindings for boot_dfuns,
190 -- which may be mentioned in imported unfoldings
192 -- Rename the Haddock documentation
193 tcg_env <- rnHaddock module_info maybe_doc tcg_env ;
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 = fmap (const rn_imports) (tcg_rn_imports gbl),
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 for no family instances
561 ; unless (null boot_fam_insts) $
562 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
563 "instances in boot files yet...")
564 -- FIXME: Why? The actual comparison is not hard, but what would
565 -- be the equivalent to the dfun bindings returned for class
566 -- instances? We can't easily equate tycons...
568 -- Check instance declarations
569 ; mb_dfun_prs <- mapM check_inst boot_insts
570 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
571 final_type_env = extendTypeEnvWithIds local_type_env boot_dfuns
572 dfun_prs = catMaybes mb_dfun_prs
573 boot_dfuns = map fst dfun_prs
574 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
575 | (boot_dfun, dfun) <- dfun_prs ]
578 ; setGlobalTypeEnv tcg_env' final_type_env }
580 check_export boot_avail -- boot_avail is exported by the boot iface
581 | name `elem` dfun_names = return ()
582 | isWiredInName name = return () -- No checking for wired-in names. In particular,
583 -- 'error' is handled by a rather gross hack
584 -- (see comments in GHC.Err.hs-boot)
586 -- Check that the actual module exports the same thing
587 | not (null missing_names)
588 = addErrAt (nameSrcSpan (head missing_names))
589 (missingBootThing (head missing_names) "exported by")
591 -- If the boot module does not *define* the thing, we are done
592 -- (it simply re-exports it, and names match, so nothing further to do)
593 | isNothing mb_boot_thing = return ()
595 -- Check that the actual module also defines the thing, and
596 -- then compare the definitions
597 | Just real_thing <- lookupTypeEnv local_type_env name,
598 Just boot_thing <- mb_boot_thing
599 = when (not (checkBootDecl boot_thing real_thing))
600 $ addErrAt (nameSrcSpan (getName boot_thing))
601 (let boot_decl = tyThingToIfaceDecl
602 (fromJust mb_boot_thing)
603 real_decl = tyThingToIfaceDecl real_thing
604 in bootMisMatch real_thing boot_decl real_decl)
607 = addErrTc (missingBootThing name "defined in")
609 name = availName boot_avail
610 mb_boot_thing = lookupTypeEnv boot_type_env name
611 missing_names = case lookupNameEnv local_export_env name of
613 Just avail -> availNames boot_avail `minusList` availNames avail
615 dfun_names = map getName boot_insts
617 local_export_env :: NameEnv AvailInfo
618 local_export_env = availsToNameEnv local_exports
620 check_inst :: Instance -> TcM (Maybe (Id, Id))
621 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
623 = case [dfun | inst <- local_insts,
624 let dfun = instanceDFunId inst,
625 idType dfun `tcEqType` boot_inst_ty ] of
626 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
627 (dfun:_) -> return (Just (local_boot_dfun, dfun))
629 boot_dfun = instanceDFunId boot_inst
630 boot_inst_ty = idType boot_dfun
631 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
634 -- This has to compare the TyThing from the .hi-boot file to the TyThing
635 -- in the current source file. We must be careful to allow alpha-renaming
636 -- where appropriate, and also the boot declaration is allowed to omit
637 -- constructors and class methods.
639 -- See rnfail055 for a good test of this stuff.
641 checkBootDecl :: TyThing -> TyThing -> Bool
643 checkBootDecl (AnId id1) (AnId id2)
645 (idType id1 `tcEqType` idType id2)
647 checkBootDecl (ATyCon tc1) (ATyCon tc2)
648 | isSynTyCon tc1 && isSynTyCon tc2
650 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
651 env = rnBndrs2 env0 tvs1 tvs2
653 eqSynRhs (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
654 = tcEqTypeX env k1 k2
655 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
656 = tcEqTypeX env t1 t2
658 equalLength tvs1 tvs2 &&
659 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
661 | isAlgTyCon tc1 && isAlgTyCon tc2
663 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2)
664 && eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
666 | isForeignTyCon tc1 && isForeignTyCon tc2
667 = tyConExtName tc1 == tyConExtName tc2
669 env0 = mkRnEnv2 emptyInScopeSet
671 eqAlgRhs AbstractTyCon _ = True
672 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
673 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
674 eqListBy eqCon (data_cons tc1) (data_cons tc2)
675 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
676 eqCon (data_con tc1) (data_con tc2)
680 = dataConName c1 == dataConName c2
681 && dataConIsInfix c1 == dataConIsInfix c2
682 && dataConStrictMarks c1 == dataConStrictMarks c2
683 && dataConFieldLabels c1 == dataConFieldLabels c2
684 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
685 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
686 env = rnBndrs2 env0 tvs1 tvs2
688 equalLength tvs1 tvs2 &&
689 eqListBy (tcEqPredX env)
690 (dataConEqTheta c1 ++ dataConDictTheta c1)
691 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
692 eqListBy (tcEqTypeX env)
693 (dataConOrigArgTys c1)
694 (dataConOrigArgTys c2)
696 checkBootDecl (AClass c1) (AClass c2)
698 (clas_tyvars1, clas_fds1, sc_theta1, _, _, op_stuff1)
699 = classExtraBigSig c1
700 (clas_tyvars2, clas_fds2, sc_theta2, _, _, op_stuff2)
701 = classExtraBigSig c2
703 env0 = mkRnEnv2 emptyInScopeSet
704 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
706 eqSig (id1, def_meth1) (id2, def_meth2)
707 = idName id1 == idName id2 &&
708 tcEqTypeX env op_ty1 op_ty2
710 (_, rho_ty1) = splitForAllTys (idType id1)
711 op_ty1 = funResultTy rho_ty1
712 (_, rho_ty2) = splitForAllTys (idType id2)
713 op_ty2 = funResultTy rho_ty2
715 eqFD (as1,bs1) (as2,bs2) =
716 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
717 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
719 equalLength clas_tyvars1 clas_tyvars2 &&
720 eqListBy eqFD clas_fds1 clas_fds2 &&
721 (null sc_theta1 && null op_stuff1
723 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
724 eqListBy eqSig op_stuff1 op_stuff2)
726 checkBootDecl (ADataCon dc1) (ADataCon dc2)
727 = pprPanic "checkBootDecl" (ppr dc1)
729 checkBootDecl _ _ = False -- probably shouldn't happen
732 missingBootThing thing what
733 = ppr thing <+> ptext (sLit "is exported by the hs-boot file, but not")
734 <+> text what <+> ptext (sLit "the module")
736 bootMisMatch thing boot_decl real_decl
737 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
738 ptext (sLit "Main module:") <+> ppr real_decl,
739 ptext (sLit "Boot file: ") <+> ppr boot_decl]
743 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
747 %************************************************************************
749 Type-checking the top level of a module
751 %************************************************************************
753 tcRnGroup takes a bunch of top-level source-code declarations, and
755 * gets supporting declarations from interface files
758 * and augments the TcGblEnv with the results
760 In Template Haskell it may be called repeatedly for each group of
761 declarations. It expects there to be an incoming TcGblEnv in the
762 monad; it augments it and returns the new TcGblEnv.
765 ------------------------------------------------
766 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
767 -- Fails if there are any errors
769 = do { -- Rename the source decls
770 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
772 -- save the renamed syntax, if we want it
774 | Just grp <- tcg_rn_decls tcg_env
775 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
779 -- Dump trace of renaming part
780 rnDump (ppr rn_decls) ;
782 return (tcg_env', rn_decls)
785 ------------------------------------------------
786 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
787 tcTopSrcDecls boot_details
788 (HsGroup { hs_tyclds = tycl_decls,
789 hs_instds = inst_decls,
790 hs_derivds = deriv_decls,
791 hs_fords = foreign_decls,
792 hs_defds = default_decls,
793 hs_annds = annotation_decls,
794 hs_ruleds = rule_decls,
795 hs_valds = val_binds })
796 = do { -- Type-check the type and class decls, and all imported decls
797 -- The latter come in via tycl_decls
798 traceTc (text "Tc2") ;
800 (tcg_env, aux_binds) <- tcTyAndClassDecls boot_details tycl_decls ;
801 -- If there are any errors, tcTyAndClassDecls fails here
803 setGblEnv tcg_env $ do {
804 -- Source-language instances, including derivings,
805 -- and import the supporting declarations
806 traceTc (text "Tc3") ;
807 (tcg_env, inst_infos, deriv_binds)
808 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
809 setGblEnv tcg_env $ do {
811 -- Foreign import declarations next.
812 traceTc (text "Tc4") ;
813 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
814 tcExtendGlobalValEnv fi_ids $ do {
816 -- Default declarations
817 traceTc (text "Tc4a") ;
818 default_tys <- tcDefaults default_decls ;
819 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
821 -- Now GHC-generated derived bindings, generics, and selectors
822 -- Do not generate warnings from compiler-generated code;
823 -- hence the use of discardWarnings
824 (tc_aux_binds, tcl_env) <- discardWarnings (tcTopBinds aux_binds) ;
825 (tc_deriv_binds, tcl_env) <- setLclTypeEnv tcl_env $
826 discardWarnings (tcTopBinds deriv_binds) ;
828 -- Value declarations next
829 traceTc (text "Tc5") ;
830 (tc_val_binds, tcl_env) <- setLclTypeEnv tcl_env $
831 tcTopBinds val_binds;
833 -- Second pass over class and instance declarations,
834 traceTc (text "Tc6") ;
835 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $
836 tcInstDecls2 tycl_decls inst_infos ;
837 showLIE (text "after instDecls2") ;
839 setLclTypeEnv tcl_env $ do { -- Environment doesn't change now
842 traceTc (text "Tc7") ;
843 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
846 annotations <- tcAnnotations annotation_decls ;
849 rules <- tcRules rule_decls ;
852 traceTc (text "Tc7a") ;
853 tcg_env <- getGblEnv ;
854 let { all_binds = tc_val_binds `unionBags`
855 tc_deriv_binds `unionBags`
856 tc_aux_binds `unionBags`
857 inst_binds `unionBags`
860 -- Extend the GblEnv with the (as yet un-zonked)
861 -- bindings, rules, foreign decls
862 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
863 tcg_rules = tcg_rules tcg_env ++ rules,
864 tcg_anns = tcg_anns tcg_env ++ annotations,
865 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
866 return (tcg_env', tcl_env)
871 %************************************************************************
875 %************************************************************************
878 checkMain :: TcM TcGblEnv
879 -- If we are in module Main, check that 'main' is defined.
881 = do { tcg_env <- getGblEnv ;
883 check_main dflags tcg_env
886 check_main dflags tcg_env
888 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
892 = do { mb_main <- lookupGlobalOccRn_maybe main_fn
893 -- Check that 'main' is in scope
894 -- It might be imported from another module!
896 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
901 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
902 ; let loc = srcLocSpan (getSrcLoc main_name)
903 ; ioTyCon <- tcLookupTyCon ioTyConName
904 ; (main_expr, res_ty)
905 <- addErrCtxt mainCtxt $
906 withBox liftedTypeKind $ \res_ty ->
907 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
909 -- See Note [Root-main Id]
910 -- Construct the binding
911 -- :Main.main :: IO res_ty = runMainIO res_ty main
912 ; run_main_id <- tcLookupId runMainIOName
913 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
914 (mkVarOccFS (fsLit "main"))
915 (getSrcSpan main_name)
916 ; root_main_id = Id.mkExportedLocalId root_main_name
917 (mkTyConApp ioTyCon [res_ty])
918 ; co = mkWpTyApps [res_ty]
919 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
920 ; main_bind = noLoc (VarBind root_main_id rhs) }
922 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
924 tcg_dus = tcg_dus tcg_env
925 `plusDU` usesOnly (unitFV main_name)
926 -- Record the use of 'main', so that we don't
927 -- complain about it being defined but not used
931 mod = tcg_mod tcg_env
932 main_mod = mainModIs dflags
933 main_fn = getMainFun dflags
935 complain_no_main | ghcLink dflags == LinkInMemory = return ()
936 | otherwise = failWithTc noMainMsg
937 -- In interactive mode, don't worry about the absence of 'main'
938 -- In other modes, fail altogether, so that we don't go on
939 -- and complain a second time when processing the export list.
941 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
942 noMainMsg = ptext (sLit "The") <+> pp_main_fn
943 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
944 pp_main_fn | main_fn == main_RDR_Unqual = ptext (sLit "function") <+> quotes (ppr main_fn)
945 | otherwise = ptext (sLit "main function") <+> quotes (ppr main_fn)
951 The function that the RTS invokes is always :Main.main, which we call
952 root_main_id. (Because GHC allows the user to have a module not
953 called Main as the main module, we can't rely on the main function
954 being called "Main.main". That's why root_main_id has a fixed module
957 This is unusual: it's a LocalId whose Name has a Module from another
958 module. Tiresomely, we must filter it out again in MkIface, les we
959 get two defns for 'main' in the interface file!
962 %*********************************************************
966 %*********************************************************
970 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
971 setInteractiveContext hsc_env icxt thing_inside
972 = let -- Initialise the tcg_inst_env with instances from all home modules.
973 -- This mimics the more selective call to hptInstances in tcRnModule.
974 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
976 updGblEnv (\env -> env {
977 tcg_rdr_env = ic_rn_gbl_env icxt,
978 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
979 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
983 tcExtendGhciEnv (ic_tmp_ids icxt) $
984 -- tcExtendGhciEnv does lots:
985 -- - it extends the local type env (tcl_env) with the given Ids,
986 -- - it extends the local rdr env (tcl_rdr) with the Names from
988 -- - it adds the free tyvars of the Ids to the tcl_tyvars
991 -- later ids in ic_tmp_ids must shadow earlier ones with the same
992 -- OccName, and tcExtendIdEnv implements this behaviour.
994 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
1001 -> InteractiveContext
1003 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1004 -- The returned [Id] is the list of new Ids bound by
1005 -- this statement. It can be used to extend the
1006 -- InteractiveContext via extendInteractiveContext.
1008 -- The returned TypecheckedHsExpr is of type IO [ () ],
1009 -- a list of the bound values, coerced to ().
1011 tcRnStmt hsc_env ictxt rdr_stmt
1012 = initTcPrintErrors hsc_env iNTERACTIVE $
1013 setInteractiveContext hsc_env ictxt $ do {
1015 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1016 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
1017 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1019 rnDump (ppr rn_stmt) ;
1021 -- The real work is done here
1022 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1023 zonked_expr <- zonkTopLExpr tc_expr ;
1024 zonked_ids <- zonkTopBndrs bound_ids ;
1026 -- None of the Ids should be of unboxed type, because we
1027 -- cast them all to HValues in the end!
1028 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1030 traceTc (text "tcs 1") ;
1031 let { global_ids = map globaliseAndTidyId zonked_ids } ;
1032 -- Note [Interactively-bound Ids in GHCi]
1034 {- ---------------------------------------------
1035 At one stage I removed any shadowed bindings from the type_env;
1036 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1037 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1039 Prelude> let f n = n * 2 :: Int
1040 Prelude> fName <- runQ [| f |]
1041 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1043 Prelude> let f n = n * 3 :: Int
1044 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1045 In the last line we use 'fName', which resolves to the *first* 'f'
1046 in scope. If we delete it from the type env, GHCi crashes because
1047 it doesn't expect that.
1049 Hence this code is commented out
1051 -------------------------------------------------- -}
1053 dumpOptTcRn Opt_D_dump_tc
1054 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1055 text "Typechecked expr" <+> ppr zonked_expr]) ;
1057 return (global_ids, zonked_expr)
1060 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1061 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1064 Note [Interactively-bound Ids in GHCi]
1065 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1066 The Ids bound by previous Stmts in Template Haskell are currently
1068 b) with an Internal Name (not External)
1069 c) and a tidied type
1071 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1072 compile an expression using these ids later, the byte code
1073 generator will consider the occurrences to be free rather than
1076 (b) They retain their Internal names becuase we don't have a suitable
1077 Module to name them with. We could revisit this choice.
1079 (c) Their types are tidied. This is important, because :info may ask
1080 to look at them, and :info expects the things it looks up to have
1084 --------------------------------------------------------------------------
1085 Typechecking Stmts in GHCi
1087 Here is the grand plan, implemented in tcUserStmt
1089 What you type The IO [HValue] that hscStmt returns
1090 ------------- ------------------------------------
1091 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1094 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1097 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1098 [NB: result not printed] bindings: [it]
1100 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1101 result showable) bindings: [it]
1103 expr (of non-IO type,
1104 result not showable) ==> error
1108 ---------------------------
1109 type PlanResult = ([Id], LHsExpr Id)
1110 type Plan = TcM PlanResult
1112 runPlans :: [Plan] -> TcM PlanResult
1113 -- Try the plans in order. If one fails (by raising an exn), try the next.
1114 -- If one succeeds, take it.
1115 runPlans [] = panic "runPlans"
1117 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1119 --------------------
1120 mkPlan :: LStmt Name -> TcM PlanResult
1121 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1122 = do { uniq <- newUnique -- is treated very specially
1123 ; let fresh_it = itName uniq
1124 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1125 matches = [mkMatch [] expr emptyLocalBinds]
1126 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1127 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1128 (HsVar bindIOName) noSyntaxExpr
1129 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1130 (HsVar thenIOName) placeHolderType
1133 -- [it <- e; print it] but not if it::()
1135 -- [let it = e; print it]
1136 ; runPlans [ -- Plan A
1137 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1138 ; it_ty <- zonkTcType (idType it_id)
1139 ; when (isUnitTy it_ty) failM
1142 -- Plan B; a naked bind statment
1143 tcGhciStmts [bind_stmt],
1145 -- Plan C; check that the let-binding is typeable all by itself.
1146 -- If not, fail; if so, try to print it.
1147 -- The two-step process avoids getting two errors: one from
1148 -- the expression itself, and one from the 'print it' part
1149 -- This two-step story is very clunky, alas
1150 do { checkNoErrs (tcGhciStmts [let_stmt])
1151 --- checkNoErrs defeats the error recovery of let-bindings
1152 ; tcGhciStmts [let_stmt, print_it] }
1155 mkPlan stmt@(L loc (BindStmt {}))
1156 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1157 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1158 (HsVar thenIOName) placeHolderType
1160 ; print_bind_result <- doptM Opt_PrintBindResult
1161 ; let print_plan = do
1162 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1163 ; v_ty <- zonkTcType (idType v_id)
1164 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1168 -- [stmt; print v] but not if v::()
1170 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1171 [tcGhciStmts [stmt]])
1175 = tcGhciStmts [stmt]
1177 ---------------------------
1178 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1180 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1181 ret_id <- tcLookupId returnIOName ; -- return @ IO
1183 ret_ty = mkListTy unitTy ;
1184 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1185 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1187 names = map unLoc (collectLStmtsBinders stmts) ;
1189 -- mk_return builds the expression
1190 -- returnIO @ [()] [coerce () x, .., coerce () z]
1192 -- Despite the inconvenience of building the type applications etc,
1193 -- this *has* to be done in type-annotated post-typecheck form
1194 -- because we are going to return a list of *polymorphic* values
1195 -- coerced to type (). If we built a *source* stmt
1196 -- return [coerce x, ..., coerce z]
1197 -- then the type checker would instantiate x..z, and we wouldn't
1198 -- get their *polymorphic* values. (And we'd get ambiguity errs
1199 -- if they were overloaded, since they aren't applied to anything.)
1200 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1201 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1202 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1206 -- OK, we're ready to typecheck the stmts
1207 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1208 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1209 mapM tcLookupId names ;
1210 -- Look up the names right in the middle,
1211 -- where they will all be in scope
1213 -- Simplify the context
1214 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1215 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1216 -- checkNoErrs ensures that the plan fails if context redn fails
1218 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1219 return (ids, mkHsDictLet const_binds $
1220 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1225 tcRnExpr just finds the type of an expression
1229 -> InteractiveContext
1231 -> IO (Messages, Maybe Type)
1232 tcRnExpr hsc_env ictxt rdr_expr
1233 = initTcPrintErrors hsc_env iNTERACTIVE $
1234 setInteractiveContext hsc_env ictxt $ do {
1236 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1239 -- Now typecheck the expression;
1240 -- it might have a rank-2 type (e.g. :t runST)
1241 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1242 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1243 tcSimplifyInteractive lie_top ;
1245 let { all_expr_ty = mkForAllTys qtvs $
1246 mkFunTys (map (idType . instToId) dict_insts) $
1248 zonkTcType all_expr_ty
1251 smpl_doc = ptext (sLit "main expression")
1254 tcRnType just finds the kind of a type
1258 -> InteractiveContext
1260 -> IO (Messages, Maybe Kind)
1261 tcRnType hsc_env ictxt rdr_type
1262 = initTcPrintErrors hsc_env iNTERACTIVE $
1263 setInteractiveContext hsc_env ictxt $ do {
1265 rn_type <- rnLHsType doc rdr_type ;
1268 -- Now kind-check the type
1269 (ty', kind) <- kcHsType rn_type ;
1273 doc = ptext (sLit "In GHCi input")
1279 %************************************************************************
1281 More GHCi stuff, to do with browsing and getting info
1283 %************************************************************************
1287 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1288 -- a package module with an interface on disk. If neither of these is
1289 -- true, then the result will be an error indicating the interface
1290 -- could not be found.
1291 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1292 getModuleExports hsc_env mod
1295 checkMods = ic_toplev_scope ic ++ ic_exports ic
1297 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1299 -- Get the export avail info and also load all orphan and family-instance
1300 -- modules. Finally, check that the family instances of all modules in the
1301 -- interactive context are consistent (these modules are in the second
1303 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1304 tcGetModuleExports mod directlyImpMods
1305 = do { let doc = ptext (sLit "context for compiling statements")
1306 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1308 -- Load any orphan-module and family instance-module
1309 -- interfaces, so their instances are visible.
1310 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1311 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1313 -- Check that the family instances of all directly loaded
1314 -- modules are consistent.
1315 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1317 ; ifaceExportNames (mi_exports iface)
1320 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1321 tcRnLookupRdrName hsc_env rdr_name
1322 = initTcPrintErrors hsc_env iNTERACTIVE $
1323 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1324 lookup_rdr_name rdr_name
1326 lookup_rdr_name rdr_name = do {
1327 -- If the identifier is a constructor (begins with an
1328 -- upper-case letter), then we need to consider both
1329 -- constructor and type class identifiers.
1330 let { rdr_names = dataTcOccs rdr_name } ;
1332 -- results :: [Either Messages Name]
1333 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1335 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1336 -- The successful lookups will be (Just name)
1337 let { (warns_s, good_names) = unzip [ (msgs, name)
1338 | (msgs, Just name) <- results] ;
1339 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1341 -- Fail if nothing good happened, else add warnings
1342 if null good_names then
1343 -- No lookup succeeded, so
1344 -- pick the first error message and report it
1345 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1346 -- while the other is "X is not in scope",
1347 -- we definitely want the former; but we might pick the latter
1348 do { addMessages (head errs_s) ; failM }
1349 else -- Add deprecation warnings
1350 mapM_ addMessages warns_s ;
1355 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1356 tcRnLookupName hsc_env name
1357 = initTcPrintErrors hsc_env iNTERACTIVE $
1358 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1359 tcRnLookupName' name
1361 -- To look up a name we have to look in the local environment (tcl_lcl)
1362 -- as well as the global environment, which is what tcLookup does.
1363 -- But we also want a TyThing, so we have to convert:
1365 tcRnLookupName' :: Name -> TcRn TyThing
1366 tcRnLookupName' name = do
1367 tcthing <- tcLookup name
1369 AGlobal thing -> return thing
1370 ATcId{tct_id=id} -> return (AnId id)
1371 _ -> panic "tcRnLookupName'"
1373 tcRnGetInfo :: HscEnv
1375 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1377 -- Used to implemnent :info in GHCi
1379 -- Look up a RdrName and return all the TyThings it might be
1380 -- A capitalised RdrName is given to us in the DataName namespace,
1381 -- but we want to treat it as *both* a data constructor
1382 -- *and* as a type or class constructor;
1383 -- hence the call to dataTcOccs, and we return up to two results
1384 tcRnGetInfo hsc_env name
1385 = initTcPrintErrors hsc_env iNTERACTIVE $
1386 let ictxt = hsc_IC hsc_env in
1387 setInteractiveContext hsc_env ictxt $ do
1389 -- Load the interface for all unqualified types and classes
1390 -- That way we will find all the instance declarations
1391 -- (Packages have not orphan modules, and we assume that
1392 -- in the home package all relevant modules are loaded.)
1393 loadUnqualIfaces ictxt
1395 thing <- tcRnLookupName' name
1396 fixity <- lookupFixityRn name
1397 ispecs <- lookupInsts thing
1398 return (thing, fixity, ispecs)
1400 lookupInsts :: TyThing -> TcM [Instance]
1401 lookupInsts (AClass cls)
1402 = do { inst_envs <- tcGetInstEnvs
1403 ; return (classInstances inst_envs cls) }
1405 lookupInsts (ATyCon tc)
1406 = do { eps <- getEps -- Load all instances for all classes that are
1407 -- in the type environment (which are all the ones
1408 -- we've seen in any interface file so far)
1409 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1411 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1412 , let dfun = instanceDFunId ispec
1415 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1416 tc_name = tyConName tc
1418 lookupInsts other = return []
1420 loadUnqualIfaces :: InteractiveContext -> TcM ()
1421 -- Load the home module for everything that is in scope unqualified
1422 -- This is so that we can accurately report the instances for
1424 loadUnqualIfaces ictxt
1426 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1428 unqual_mods = [ nameModule name
1429 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1430 let name = gre_name gre,
1431 not (isInternalName name),
1432 isTcOcc (nameOccName name), -- Types and classes only
1433 unQualOK gre ] -- In scope unqualified
1434 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1438 %************************************************************************
1442 %************************************************************************
1445 rnDump :: SDoc -> TcRn ()
1446 -- Dump, with a banner, if -ddump-rn
1447 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1449 tcDump :: TcGblEnv -> TcRn ()
1451 = do { dflags <- getDOpts ;
1453 -- Dump short output if -ddump-types or -ddump-tc
1454 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1455 (dumpTcRn short_dump) ;
1457 -- Dump bindings if -ddump-tc
1458 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1461 short_dump = pprTcGblEnv env
1462 full_dump = pprLHsBinds (tcg_binds env)
1463 -- NB: foreign x-d's have undefined's in their types;
1464 -- hence can't show the tc_fords
1467 = do { dflags <- getDOpts ;
1468 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1469 (dumpTcRn (pprModGuts mod_guts)) ;
1471 -- Dump bindings if -ddump-tc
1472 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1474 full_dump = pprCoreBindings (mg_binds mod_guts)
1476 -- It's unpleasant having both pprModGuts and pprModDetails here
1477 pprTcGblEnv :: TcGblEnv -> SDoc
1478 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1480 tcg_fam_insts = fam_insts,
1482 tcg_imports = imports })
1483 = vcat [ ppr_types insts type_env
1484 , ppr_tycons fam_insts type_env
1486 , ppr_fam_insts fam_insts
1487 , vcat (map ppr rules)
1488 , ppr_gen_tycons (typeEnvTyCons type_env)
1489 , ptext (sLit "Dependent modules:") <+>
1490 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1491 , ptext (sLit "Dependent packages:") <+>
1492 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1493 where -- The two uses of sortBy are just to reduce unnecessary
1494 -- wobbling in testsuite output
1495 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1496 = (mod_name1 `stableModuleNameCmp` mod_name2)
1498 (is_boot1 `compare` is_boot2)
1500 pprModGuts :: ModGuts -> SDoc
1501 pprModGuts (ModGuts { mg_types = type_env,
1503 = vcat [ ppr_types [] type_env,
1506 ppr_types :: [Instance] -> TypeEnv -> SDoc
1507 ppr_types insts type_env
1508 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1510 dfun_ids = map instanceDFunId insts
1511 ids = [id | id <- typeEnvIds type_env, want_sig id]
1512 want_sig id | opt_PprStyle_Debug = True
1513 | otherwise = isLocalId id &&
1514 isExternalName (idName id) &&
1515 not (id `elem` dfun_ids)
1516 -- isLocalId ignores data constructors, records selectors etc.
1517 -- The isExternalName ignores local dictionary and method bindings
1518 -- that the type checker has invented. Top-level user-defined things
1519 -- have External names.
1521 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1522 ppr_tycons fam_insts type_env
1523 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1525 fi_tycons = map famInstTyCon fam_insts
1526 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1527 want_tycon tycon | opt_PprStyle_Debug = True
1528 | otherwise = not (isImplicitTyCon tycon) &&
1529 isExternalName (tyConName tycon) &&
1530 not (tycon `elem` fi_tycons)
1532 ppr_insts :: [Instance] -> SDoc
1533 ppr_insts [] = empty
1534 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1536 ppr_fam_insts :: [FamInst] -> SDoc
1537 ppr_fam_insts [] = empty
1538 ppr_fam_insts fam_insts =
1539 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1541 ppr_sigs :: [Var] -> SDoc
1543 -- Print type signatures; sort by OccName
1544 = vcat (map ppr_sig (sortLe le_sig ids))
1546 le_sig id1 id2 = getOccName id1 <= getOccName id2
1547 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1549 ppr_tydecls :: [TyCon] -> SDoc
1551 -- Print type constructor info; sort by OccName
1552 = vcat (map ppr_tycon (sortLe le_sig tycons))
1554 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1556 | isCoercionTyCon tycon = ptext (sLit "coercion") <+> ppr tycon
1557 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1559 ppr_rules :: [CoreRule] -> SDoc
1560 ppr_rules [] = empty
1561 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1562 nest 4 (pprRules rs),
1565 ppr_gen_tycons [] = empty
1566 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1567 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]