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 )
109 import Data.Maybe ( isJust )
111 #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
133 module_info maybe_doc))
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 -- Rename the Haddock documentation
192 tcg_env <- rnHaddock module_info maybe_doc tcg_env ;
194 -- Report unused names
195 reportUnusedNames export_ies tcg_env ;
197 -- Dump output and return
204 %************************************************************************
208 %************************************************************************
211 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
212 tcRnImports hsc_env this_mod import_decls
213 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
215 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
216 ; dep_mods = imp_dep_mods imports
218 -- We want instance declarations from all home-package
219 -- modules below this one, including boot modules, except
220 -- ourselves. The 'except ourselves' is so that we don't
221 -- get the instances from this module's hs-boot file
222 ; want_instances :: ModuleName -> Bool
223 ; want_instances mod = mod `elemUFM` dep_mods
224 && mod /= moduleName this_mod
225 ; (home_insts, home_fam_insts) = hptInstances hsc_env
229 -- Record boot-file info in the EPS, so that it's
230 -- visible to loadHiBootInterface in tcRnSrcDecls,
231 -- and any other incrementally-performed imports
232 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
234 -- Update the gbl env
235 ; updGblEnv ( \ gbl ->
237 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
238 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
239 tcg_rn_imports = fmap (const rn_imports) (tcg_rn_imports gbl),
240 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
241 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
246 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
247 -- Fail if there are any errors so far
248 -- The error printing (if needed) takes advantage
249 -- of the tcg_env we have now set
250 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
253 -- Load any orphan-module and family instance-module
254 -- interfaces, so that their rules and instance decls will be
256 ; loadOrphanModules (imp_orphs imports) False
257 ; loadOrphanModules (imp_finsts imports) True
259 -- Check type-familily consistency
260 ; traceRn (text "rn1: checking family instance consistency")
261 ; let { dir_imp_mods = moduleEnvKeys
264 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
270 %************************************************************************
272 Type-checking external-core modules
274 %************************************************************************
277 tcRnExtCore :: HscEnv
279 -> IO (Messages, Maybe ModGuts)
280 -- Nothing => some error occurred
282 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
283 -- The decls are IfaceDecls; all names are original names
284 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
286 initTc hsc_env ExtCoreFile False this_mod $ do {
288 let { ldecls = map noLoc decls } ;
290 -- bring the type and class decls into scope
291 -- ToDo: check that this doesn't need to extract the val binds.
292 -- It seems that only the type and class decls need to be in scope below because
293 -- (a) tcTyAndClassDecls doesn't need the val binds, and
294 -- (b) tcExtCoreBindings doesn't need anything
295 -- (in fact, it might not even need to be in the scope of
296 -- this tcg_env at all)
297 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
298 tc_envs <- extendGlobalRdrEnvRn avails emptyFsEnv {- no fixity decls -} ;
300 setEnvs tc_envs $ do {
302 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
304 -- Dump trace of renaming part
305 rnDump (ppr rn_decls) ;
307 -- Typecheck them all together so that
308 -- any mutually recursive types are done right
309 tcg_env <- tcTyAndClassDecls emptyModDetails rn_decls ;
310 -- Make the new type env available to stuff slurped from interface files
312 setGblEnv tcg_env $ do {
314 -- Now the core bindings
315 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
319 bndrs = bindersOfBinds core_binds ;
320 my_exports = map (Avail . idName) bndrs ;
321 -- ToDo: export the data types also?
324 extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
326 mod_guts = ModGuts { mg_module = this_mod,
328 mg_used_names = emptyNameSet, -- ToDo: compute usage
329 mg_dir_imps = emptyModuleEnv, -- ??
330 mg_deps = noDependencies, -- ??
331 mg_exports = my_exports,
332 mg_types = final_type_env,
333 mg_insts = tcg_insts tcg_env,
334 mg_fam_insts = tcg_fam_insts tcg_env,
335 mg_inst_env = tcg_inst_env tcg_env,
336 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
338 mg_binds = core_binds,
341 mg_rdr_env = emptyGlobalRdrEnv,
342 mg_fix_env = emptyFixityEnv,
343 mg_warns = NoWarnings,
344 mg_foreign = NoStubs,
345 mg_hpc_info = emptyHpcInfo False,
346 mg_modBreaks = emptyModBreaks,
347 mg_vect_info = noVectInfo
350 tcCoreDump mod_guts ;
355 mkFakeGroup decls -- Rather clumsy; lots of unused fields
356 = emptyRdrGroup { hs_tyclds = decls }
360 %************************************************************************
362 Type-checking the top level of a module
364 %************************************************************************
367 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
368 -- Returns the variables free in the decls
369 -- Reason: solely to report unused imports and bindings
370 tcRnSrcDecls boot_iface decls
371 = do { -- Do all the declarations
372 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
374 -- Finish simplifying class constraints
376 -- tcSimplifyTop deals with constant or ambiguous InstIds.
377 -- How could there be ambiguous ones? They can only arise if a
378 -- top-level decl falls under the monomorphism restriction
379 -- and no subsequent decl instantiates its type.
381 -- We do this after checkMain, so that we use the type info
382 -- thaat checkMain adds
384 -- We do it with both global and local env in scope:
385 -- * the global env exposes the instances to tcSimplifyTop
386 -- * the local env exposes the local Ids to tcSimplifyTop,
387 -- so that we get better error messages (monomorphism restriction)
388 traceTc (text "Tc8") ;
389 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
391 -- Backsubstitution. This must be done last.
392 -- Even tcSimplifyTop may do some unification.
393 traceTc (text "Tc9") ;
394 let { (tcg_env, _) = tc_envs
395 ; TcGblEnv { tcg_type_env = type_env,
398 tcg_fords = fords } = tcg_env
399 ; all_binds = binds `unionBags` inst_binds } ;
401 failIfErrsM ; -- Don't zonk if there have been errors
402 -- It's a waste of time; and we may get debug warnings
403 -- about strangely-typed TyCons!
405 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
408 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
409 ; tcg_env' = tcg_env { tcg_binds = binds',
411 tcg_fords = fords' } } ;
413 setGlobalTypeEnv tcg_env' final_type_env
416 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
417 -- Loops around dealing with each top level inter-splice group
418 -- in turn, until it's dealt with the entire module
419 tc_rn_src_decls boot_details ds
420 = do { let { (first_group, group_tail) = findSplice ds } ;
421 -- If ds is [] we get ([], Nothing)
423 -- Deal with decls up to, but not including, the first splice
424 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
425 -- rnTopSrcDecls fails if there are any errors
427 (tcg_env, tcl_env) <- setGblEnv tcg_env $
428 tcTopSrcDecls boot_details rn_decls ;
430 -- If there is no splice, we're nearly done
431 setEnvs (tcg_env, tcl_env) $
433 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
434 return (tcg_env, tcl_env)
437 -- If there's a splice, we must carry on
438 Just (SpliceDecl splice_expr, rest_ds) -> do {
440 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
443 -- Rename the splice expression, and get its supporting decls
444 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
445 -- checkNoErrs: don't typecheck if renaming failed
446 rnDump (ppr rn_splice_expr) ;
448 -- Execute the splice
449 spliced_decls <- tcSpliceDecls rn_splice_expr ;
451 -- Glue them on the front of the remaining decls and loop
452 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
453 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
458 %************************************************************************
460 Compiling hs-boot source files, and
461 comparing the hi-boot interface with the real thing
463 %************************************************************************
466 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
467 tcRnHsBootDecls decls
468 = do { let { (first_group, group_tail) = findSplice decls }
471 Just stuff -> spliceInHsBootErr stuff
474 -- Rename the declarations
475 ; (tcg_env, HsGroup {
476 hs_tyclds = tycl_decls,
477 hs_instds = inst_decls,
478 hs_derivds = deriv_decls,
480 hs_defds = _, -- Todo: check no foreign decls, no rules,
481 hs_ruleds = _, -- no default decls and no annotation decls
483 hs_valds = val_binds }) <- rnTopSrcDecls first_group
484 ; setGblEnv tcg_env $ do {
487 -- Typecheck type/class decls
488 ; traceTc (text "Tc2")
489 ; tcg_env <- tcTyAndClassDecls emptyModDetails tycl_decls
490 ; setGblEnv tcg_env $ do {
492 -- Typecheck instance decls
493 ; traceTc (text "Tc3")
494 ; (tcg_env, inst_infos, _deriv_binds)
495 <- tcInstDecls1 tycl_decls inst_decls deriv_decls
496 ; setGblEnv tcg_env $ do {
498 -- Typecheck value declarations
499 ; traceTc (text "Tc5")
500 ; val_ids <- tcHsBootSigs val_binds
503 -- No simplification or zonking to do
504 ; traceTc (text "Tc7a")
505 ; gbl_env <- getGblEnv
507 -- Make the final type-env
508 -- Include the dfun_ids so that their type sigs
509 -- are written into the interface file
510 ; let { type_env0 = tcg_type_env gbl_env
511 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
512 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
513 ; dfun_ids = map iDFunId inst_infos }
514 ; setGlobalTypeEnv gbl_env type_env2
517 spliceInHsBootErr (SpliceDecl (L loc _), _)
518 = addErrAt loc (ptext (sLit "Splices are not allowed in hs-boot files"))
521 Once we've typechecked the body of the module, we want to compare what
522 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
525 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
526 -- Compare the hi-boot file for this module (if there is one)
527 -- with the type environment we've just come up with
528 -- In the common case where there is no hi-boot file, the list
529 -- of boot_names is empty.
531 -- The bindings we return give bindings for the dfuns defined in the
532 -- hs-boot file, such as $fbEqT = $fEqT
535 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
536 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
537 tcg_type_env = local_type_env, tcg_exports = local_exports })
538 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
539 md_types = boot_type_env, md_exports = boot_exports })
540 | isHsBoot hs_src -- Current module is already a hs-boot file!
544 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
547 -- Check the exports of the boot module, one by one
548 ; mapM_ check_export boot_exports
550 -- Check instance declarations
551 ; mb_dfun_prs <- mapM check_inst boot_insts
552 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds,
553 tcg_type_env = extendTypeEnvWithIds local_type_env boot_dfuns }
554 dfun_prs = catMaybes mb_dfun_prs
555 boot_dfuns = map fst dfun_prs
556 dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun)
557 | (boot_dfun, dfun) <- dfun_prs ]
559 -- Check for no family instances
560 ; unless (null boot_fam_insts) $
561 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
562 "instances in boot files yet...")
563 -- FIXME: Why? The actual comparison is not hard, but what would
564 -- be the equivalent to the dfun bindings returned for class
565 -- instances? We can't easily equate tycons...
567 -- Check instance declarations
568 ; mb_dfun_prs <- mapM check_inst boot_insts
569 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
570 final_type_env = extendTypeEnvWithIds local_type_env boot_dfuns
571 dfun_prs = catMaybes mb_dfun_prs
572 boot_dfuns = map fst dfun_prs
573 dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun)
574 | (boot_dfun, dfun) <- dfun_prs ]
577 ; setGlobalTypeEnv tcg_env' final_type_env }
579 check_export boot_avail -- boot_avail is exported by the boot iface
580 | name `elem` dfun_names = return ()
581 | isWiredInName name = return () -- No checking for wired-in names. In particular,
582 -- 'error' is handled by a rather gross hack
583 -- (see comments in GHC.Err.hs-boot)
585 -- Check that the actual module exports the same thing
586 | not (null missing_names)
587 = addErrAt (nameSrcSpan (head missing_names))
588 (missingBootThing (head missing_names) "exported by")
590 -- If the boot module does not *define* the thing, we are done
591 -- (it simply re-exports it, and names match, so nothing further to do)
592 | isNothing mb_boot_thing = return ()
594 -- Check that the actual module also defines the thing, and
595 -- then compare the definitions
596 | Just real_thing <- lookupTypeEnv local_type_env name,
597 Just boot_thing <- mb_boot_thing
598 = when (not (checkBootDecl boot_thing real_thing))
599 $ addErrAt (nameSrcSpan (getName boot_thing))
600 (let boot_decl = tyThingToIfaceDecl
601 (fromJust mb_boot_thing)
602 real_decl = tyThingToIfaceDecl real_thing
603 in bootMisMatch real_thing boot_decl real_decl)
606 = addErrTc (missingBootThing name "defined in")
608 name = availName boot_avail
609 mb_boot_thing = lookupTypeEnv boot_type_env name
610 missing_names = case lookupNameEnv local_export_env name of
612 Just avail -> availNames boot_avail `minusList` availNames avail
614 dfun_names = map getName boot_insts
616 local_export_env :: NameEnv AvailInfo
617 local_export_env = availsToNameEnv local_exports
619 check_inst :: Instance -> TcM (Maybe (Id, Id))
620 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
622 = case [dfun | inst <- local_insts,
623 let dfun = instanceDFunId inst,
624 idType dfun `tcEqType` boot_inst_ty ] of
625 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
626 (dfun:_) -> return (Just (local_boot_dfun, dfun))
628 boot_dfun = instanceDFunId boot_inst
629 boot_inst_ty = idType boot_dfun
630 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
633 -- This has to compare the TyThing from the .hi-boot file to the TyThing
634 -- in the current source file. We must be careful to allow alpha-renaming
635 -- where appropriate, and also the boot declaration is allowed to omit
636 -- constructors and class methods.
638 -- See rnfail055 for a good test of this stuff.
640 checkBootDecl :: TyThing -> TyThing -> Bool
642 checkBootDecl (AnId id1) (AnId id2)
644 (idType id1 `tcEqType` idType id2)
646 checkBootDecl (ATyCon tc1) (ATyCon tc2)
647 | isSynTyCon tc1 && isSynTyCon tc2
649 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
650 env = rnBndrs2 env0 tvs1 tvs2
652 eqSynRhs (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
653 = tcEqTypeX env k1 k2
654 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
655 = tcEqTypeX env t1 t2
657 equalLength tvs1 tvs2 &&
658 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
660 | isAlgTyCon tc1 && isAlgTyCon tc2
662 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2)
663 && eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
665 | isForeignTyCon tc1 && isForeignTyCon tc2
666 = tyConExtName tc1 == tyConExtName tc2
668 env0 = mkRnEnv2 emptyInScopeSet
670 eqAlgRhs AbstractTyCon _ = True
671 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
672 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
673 eqListBy eqCon (data_cons tc1) (data_cons tc2)
674 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
675 eqCon (data_con tc1) (data_con tc2)
679 = dataConName c1 == dataConName c2
680 && dataConIsInfix c1 == dataConIsInfix c2
681 && dataConStrictMarks c1 == dataConStrictMarks c2
682 && dataConFieldLabels c1 == dataConFieldLabels c2
683 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
684 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
685 env = rnBndrs2 env0 tvs1 tvs2
687 equalLength tvs1 tvs2 &&
688 eqListBy (tcEqPredX env)
689 (dataConEqTheta c1 ++ dataConDictTheta c1)
690 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
691 eqListBy (tcEqTypeX env)
692 (dataConOrigArgTys c1)
693 (dataConOrigArgTys c2)
695 checkBootDecl (AClass c1) (AClass c2)
697 (clas_tyvars1, clas_fds1, sc_theta1, _, _, op_stuff1)
698 = classExtraBigSig c1
699 (clas_tyvars2, clas_fds2, sc_theta2, _, _, op_stuff2)
700 = classExtraBigSig c2
702 env0 = mkRnEnv2 emptyInScopeSet
703 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
705 eqSig (id1, def_meth1) (id2, def_meth2)
706 = idName id1 == idName id2 &&
707 tcEqTypeX env op_ty1 op_ty2
709 (_, rho_ty1) = splitForAllTys (idType id1)
710 op_ty1 = funResultTy rho_ty1
711 (_, rho_ty2) = splitForAllTys (idType id2)
712 op_ty2 = funResultTy rho_ty2
714 eqFD (as1,bs1) (as2,bs2) =
715 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
716 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
718 equalLength clas_tyvars1 clas_tyvars2 &&
719 eqListBy eqFD clas_fds1 clas_fds2 &&
720 (null sc_theta1 && null op_stuff1
722 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
723 eqListBy eqSig op_stuff1 op_stuff2)
725 checkBootDecl (ADataCon dc1) (ADataCon dc2)
726 = pprPanic "checkBootDecl" (ppr dc1)
728 checkBootDecl _ _ = False -- probably shouldn't happen
731 missingBootThing thing what
732 = ppr thing <+> ptext (sLit "is exported by the hs-boot file, but not")
733 <+> text what <+> ptext (sLit "the module")
735 bootMisMatch thing boot_decl real_decl
736 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
737 ptext (sLit "Main module:") <+> ppr real_decl,
738 ptext (sLit "Boot file: ") <+> ppr boot_decl]
742 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
746 %************************************************************************
748 Type-checking the top level of a module
750 %************************************************************************
752 tcRnGroup takes a bunch of top-level source-code declarations, and
754 * gets supporting declarations from interface files
757 * and augments the TcGblEnv with the results
759 In Template Haskell it may be called repeatedly for each group of
760 declarations. It expects there to be an incoming TcGblEnv in the
761 monad; it augments it and returns the new TcGblEnv.
764 ------------------------------------------------
765 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
766 -- Fails if there are any errors
768 = do { -- Rename the source decls
769 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
771 -- save the renamed syntax, if we want it
773 | Just grp <- tcg_rn_decls tcg_env
774 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
778 -- Dump trace of renaming part
779 rnDump (ppr rn_decls) ;
781 return (tcg_env', rn_decls)
784 ------------------------------------------------
785 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
786 tcTopSrcDecls boot_details
787 (HsGroup { hs_tyclds = tycl_decls,
788 hs_instds = inst_decls,
789 hs_derivds = deriv_decls,
790 hs_fords = foreign_decls,
791 hs_defds = default_decls,
792 hs_annds = annotation_decls,
793 hs_ruleds = rule_decls,
794 hs_valds = val_binds })
795 = do { -- Type-check the type and class decls, and all imported decls
796 -- The latter come in via tycl_decls
797 traceTc (text "Tc2") ;
799 tcg_env <- tcTyAndClassDecls boot_details tycl_decls ;
800 -- If there are any errors, tcTyAndClassDecls fails here
802 setGblEnv tcg_env $ do {
803 -- Source-language instances, including derivings,
804 -- and import the supporting declarations
805 traceTc (text "Tc3") ;
806 (tcg_env, inst_infos, deriv_binds)
807 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
808 setGblEnv tcg_env $ do {
810 -- Foreign import declarations next. No zonking necessary
811 -- here; we can tuck them straight into the global environment.
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 -- Value declarations next
822 -- We also typecheck any extra binds that came out
823 -- of the "deriving" process (deriv_binds)
824 traceTc (text "Tc5") ;
825 (tc_val_binds, tcl_env) <- tcTopBinds val_binds ;
826 setLclTypeEnv tcl_env $ do {
828 -- Now GHC-generated derived bindings and generics.
829 -- Do not generate warnings from compiler-generated code.
830 (tc_deriv_binds, tcl_env) <- discardWarnings $
831 tcTopBinds deriv_binds ;
833 -- Second pass over class and instance declarations,
834 traceTc (text "Tc6") ;
835 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $ tcInstDecls2 tycl_decls inst_infos ;
836 showLIE (text "after instDecls2") ;
839 -- They need to be zonked, so we return them
840 traceTc (text "Tc7") ;
841 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
844 annotations <- tcAnnotations annotation_decls ;
847 rules <- tcRules rule_decls ;
850 traceTc (text "Tc7a") ;
851 tcg_env <- getGblEnv ;
852 let { all_binds = tc_val_binds `unionBags`
853 tc_deriv_binds `unionBags`
854 inst_binds `unionBags`
857 -- Extend the GblEnv with the (as yet un-zonked)
858 -- bindings, rules, foreign decls
859 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
860 tcg_rules = tcg_rules tcg_env ++ rules,
861 tcg_anns = tcg_anns tcg_env ++ annotations,
862 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
863 return (tcg_env', tcl_env)
868 %************************************************************************
872 %************************************************************************
875 checkMain :: TcM TcGblEnv
876 -- If we are in module Main, check that 'main' is defined.
878 = do { tcg_env <- getGblEnv ;
880 check_main dflags tcg_env
883 check_main dflags tcg_env
885 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
889 = do { mb_main <- lookupSrcOcc_maybe main_fn
890 -- Check that 'main' is in scope
891 -- It might be imported from another module!
893 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
898 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
899 ; let loc = srcLocSpan (getSrcLoc main_name)
900 ; ioTyCon <- tcLookupTyCon ioTyConName
901 ; (main_expr, res_ty)
902 <- addErrCtxt mainCtxt $
903 withBox liftedTypeKind $ \res_ty ->
904 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
906 -- See Note [Root-main Id]
907 -- Construct the binding
908 -- :Main.main :: IO res_ty = runMainIO res_ty main
909 ; run_main_id <- tcLookupId runMainIOName
910 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
911 (mkVarOccFS (fsLit "main"))
912 (getSrcSpan main_name)
913 ; root_main_id = Id.mkExportedLocalId root_main_name
914 (mkTyConApp ioTyCon [res_ty])
915 ; co = mkWpTyApps [res_ty]
916 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
917 ; main_bind = mkVarBind root_main_id rhs }
919 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
921 tcg_dus = tcg_dus tcg_env
922 `plusDU` usesOnly (unitFV main_name)
923 -- Record the use of 'main', so that we don't
924 -- complain about it being defined but not used
928 mod = tcg_mod tcg_env
929 main_mod = mainModIs dflags
930 main_fn = getMainFun dflags
932 complain_no_main | ghcLink dflags == LinkInMemory = return ()
933 | otherwise = failWithTc noMainMsg
934 -- In interactive mode, don't worry about the absence of 'main'
935 -- In other modes, fail altogether, so that we don't go on
936 -- and complain a second time when processing the export list.
938 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
939 noMainMsg = ptext (sLit "The") <+> pp_main_fn
940 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
941 pp_main_fn | main_fn == main_RDR_Unqual = ptext (sLit "function") <+> quotes (ppr main_fn)
942 | otherwise = ptext (sLit "main function") <+> quotes (ppr main_fn)
948 The function that the RTS invokes is always :Main.main, which we call
949 root_main_id. (Because GHC allows the user to have a module not
950 called Main as the main module, we can't rely on the main function
951 being called "Main.main". That's why root_main_id has a fixed module
954 This is unusual: it's a LocalId whose Name has a Module from another
955 module. Tiresomely, we must filter it out again in MkIface, les we
956 get two defns for 'main' in the interface file!
959 %*********************************************************
963 %*********************************************************
967 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
968 setInteractiveContext hsc_env icxt thing_inside
969 = let -- Initialise the tcg_inst_env with instances from all home modules.
970 -- This mimics the more selective call to hptInstances in tcRnModule.
971 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
973 updGblEnv (\env -> env {
974 tcg_rdr_env = ic_rn_gbl_env icxt,
975 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
976 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
980 tcExtendGhciEnv (ic_tmp_ids icxt) $
981 -- tcExtendGhciEnv does lots:
982 -- - it extends the local type env (tcl_env) with the given Ids,
983 -- - it extends the local rdr env (tcl_rdr) with the Names from
985 -- - it adds the free tyvars of the Ids to the tcl_tyvars
988 -- later ids in ic_tmp_ids must shadow earlier ones with the same
989 -- OccName, and tcExtendIdEnv implements this behaviour.
991 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
998 -> InteractiveContext
1000 -> IO (Messages, Maybe ([Id], LHsExpr Id))
1001 -- The returned [Id] is the list of new Ids bound by
1002 -- this statement. It can be used to extend the
1003 -- InteractiveContext via extendInteractiveContext.
1005 -- The returned TypecheckedHsExpr is of type IO [ () ],
1006 -- a list of the bound values, coerced to ().
1008 tcRnStmt hsc_env ictxt rdr_stmt
1009 = initTcPrintErrors hsc_env iNTERACTIVE $
1010 setInteractiveContext hsc_env ictxt $ do {
1012 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1013 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
1014 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1016 rnDump (ppr rn_stmt) ;
1018 -- The real work is done here
1019 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1020 zonked_expr <- zonkTopLExpr tc_expr ;
1021 zonked_ids <- zonkTopBndrs bound_ids ;
1023 -- None of the Ids should be of unboxed type, because we
1024 -- cast them all to HValues in the end!
1025 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1027 traceTc (text "tcs 1") ;
1028 let { global_ids = map globaliseAndTidy zonked_ids } ;
1030 {- ---------------------------------------------
1031 At one stage I removed any shadowed bindings from the type_env;
1032 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1033 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1035 Prelude> let f n = n * 2 :: Int
1036 Prelude> fName <- runQ [| f |]
1037 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1039 Prelude> let f n = n * 3 :: Int
1040 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1041 In the last line we use 'fName', which resolves to the *first* 'f'
1042 in scope. If we delete it from the type env, GHCi crashes because
1043 it doesn't expect that.
1045 Hence this code is commented out
1047 -------------------------------------------------- -}
1049 dumpOptTcRn Opt_D_dump_tc
1050 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1051 text "Typechecked expr" <+> ppr zonked_expr]) ;
1053 return (global_ids, zonked_expr)
1056 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1057 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1059 globaliseAndTidy :: Id -> Id
1060 globaliseAndTidy id -- Note [Interactively-bound Ids in GHCi]
1061 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
1063 tidy_type = tidyTopType (idType id)
1066 Note [Interactively-bound Ids in GHCi]
1067 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1068 The Ids bound by previous Stmts in Template Haskell are currently
1070 b) with an Internal Name (not External)
1071 c) and a tidied type
1073 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1074 compile an expression using these ids later, the byte code
1075 generator will consider the occurrences to be free rather than
1078 (b) They retain their Internal names becuase we don't have a suitable
1079 Module to name them with. We could revisit this choice.
1081 (c) Their types are tidied. This is important, because :info may ask
1082 to look at them, and :info expects the things it looks up to have
1086 --------------------------------------------------------------------------
1087 Typechecking Stmts in GHCi
1089 Here is the grand plan, implemented in tcUserStmt
1091 What you type The IO [HValue] that hscStmt returns
1092 ------------- ------------------------------------
1093 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1096 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1099 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1100 [NB: result not printed] bindings: [it]
1102 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1103 result showable) bindings: [it]
1105 expr (of non-IO type,
1106 result not showable) ==> error
1110 ---------------------------
1111 type PlanResult = ([Id], LHsExpr Id)
1112 type Plan = TcM PlanResult
1114 runPlans :: [Plan] -> TcM PlanResult
1115 -- Try the plans in order. If one fails (by raising an exn), try the next.
1116 -- If one succeeds, take it.
1117 runPlans [] = panic "runPlans"
1119 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1121 --------------------
1122 mkPlan :: LStmt Name -> TcM PlanResult
1123 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1124 = do { uniq <- newUnique -- is treated very specially
1125 ; let fresh_it = itName uniq
1126 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1127 matches = [mkMatch [] expr emptyLocalBinds]
1128 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1129 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1130 (HsVar bindIOName) noSyntaxExpr
1131 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1132 (HsVar thenIOName) placeHolderType
1135 -- [it <- e; print it] but not if it::()
1137 -- [let it = e; print it]
1138 ; runPlans [ -- Plan A
1139 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1140 ; it_ty <- zonkTcType (idType it_id)
1141 ; when (isUnitTy it_ty) failM
1144 -- Plan B; a naked bind statment
1145 tcGhciStmts [bind_stmt],
1147 -- Plan C; check that the let-binding is typeable all by itself.
1148 -- If not, fail; if so, try to print it.
1149 -- The two-step process avoids getting two errors: one from
1150 -- the expression itself, and one from the 'print it' part
1151 -- This two-step story is very clunky, alas
1152 do { checkNoErrs (tcGhciStmts [let_stmt])
1153 --- checkNoErrs defeats the error recovery of let-bindings
1154 ; tcGhciStmts [let_stmt, print_it] }
1157 mkPlan stmt@(L loc (BindStmt {}))
1158 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1159 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1160 (HsVar thenIOName) placeHolderType
1162 ; print_bind_result <- doptM Opt_PrintBindResult
1163 ; let print_plan = do
1164 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1165 ; v_ty <- zonkTcType (idType v_id)
1166 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1170 -- [stmt; print v] but not if v::()
1172 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1173 [tcGhciStmts [stmt]])
1177 = tcGhciStmts [stmt]
1179 ---------------------------
1180 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1182 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1183 ret_id <- tcLookupId returnIOName ; -- return @ IO
1185 ret_ty = mkListTy unitTy ;
1186 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1187 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1189 names = map unLoc (collectLStmtsBinders stmts) ;
1191 -- mk_return builds the expression
1192 -- returnIO @ [()] [coerce () x, .., coerce () z]
1194 -- Despite the inconvenience of building the type applications etc,
1195 -- this *has* to be done in type-annotated post-typecheck form
1196 -- because we are going to return a list of *polymorphic* values
1197 -- coerced to type (). If we built a *source* stmt
1198 -- return [coerce x, ..., coerce z]
1199 -- then the type checker would instantiate x..z, and we wouldn't
1200 -- get their *polymorphic* values. (And we'd get ambiguity errs
1201 -- if they were overloaded, since they aren't applied to anything.)
1202 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1203 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1204 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1208 -- OK, we're ready to typecheck the stmts
1209 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1210 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1211 mapM tcLookupId names ;
1212 -- Look up the names right in the middle,
1213 -- where they will all be in scope
1215 -- Simplify the context
1216 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1217 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1218 -- checkNoErrs ensures that the plan fails if context redn fails
1220 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1221 return (ids, mkHsDictLet const_binds $
1222 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1227 tcRnExpr just finds the type of an expression
1231 -> InteractiveContext
1233 -> IO (Messages, Maybe Type)
1234 tcRnExpr hsc_env ictxt rdr_expr
1235 = initTcPrintErrors hsc_env iNTERACTIVE $
1236 setInteractiveContext hsc_env ictxt $ do {
1238 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1241 -- Now typecheck the expression;
1242 -- it might have a rank-2 type (e.g. :t runST)
1243 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1244 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1245 tcSimplifyInteractive lie_top ;
1247 let { all_expr_ty = mkForAllTys qtvs $
1248 mkFunTys (map (idType . instToId) dict_insts) $
1250 zonkTcType all_expr_ty
1253 smpl_doc = ptext (sLit "main expression")
1256 tcRnType just finds the kind of a type
1260 -> InteractiveContext
1262 -> IO (Messages, Maybe Kind)
1263 tcRnType hsc_env ictxt rdr_type
1264 = initTcPrintErrors hsc_env iNTERACTIVE $
1265 setInteractiveContext hsc_env ictxt $ do {
1267 rn_type <- rnLHsType doc rdr_type ;
1270 -- Now kind-check the type
1271 (ty', kind) <- kcHsType rn_type ;
1275 doc = ptext (sLit "In GHCi input")
1281 %************************************************************************
1283 More GHCi stuff, to do with browsing and getting info
1285 %************************************************************************
1289 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1290 -- a package module with an interface on disk. If neither of these is
1291 -- true, then the result will be an error indicating the interface
1292 -- could not be found.
1293 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1294 getModuleExports hsc_env mod
1297 checkMods = ic_toplev_scope ic ++ ic_exports ic
1299 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1301 -- Get the export avail info and also load all orphan and family-instance
1302 -- modules. Finally, check that the family instances of all modules in the
1303 -- interactive context are consistent (these modules are in the second
1305 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1306 tcGetModuleExports mod directlyImpMods
1307 = do { let doc = ptext (sLit "context for compiling statements")
1308 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1310 -- Load any orphan-module and family instance-module
1311 -- interfaces, so their instances are visible.
1312 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1313 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1315 -- Check that the family instances of all directly loaded
1316 -- modules are consistent.
1317 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1319 ; ifaceExportNames (mi_exports iface)
1322 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1323 tcRnLookupRdrName hsc_env rdr_name
1324 = initTcPrintErrors hsc_env iNTERACTIVE $
1325 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1326 lookup_rdr_name rdr_name
1328 lookup_rdr_name rdr_name = do {
1329 -- If the identifier is a constructor (begins with an
1330 -- upper-case letter), then we need to consider both
1331 -- constructor and type class identifiers.
1332 let { rdr_names = dataTcOccs rdr_name } ;
1334 -- results :: [Either Messages Name]
1335 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1337 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1338 -- The successful lookups will be (Just name)
1339 let { (warns_s, good_names) = unzip [ (msgs, name)
1340 | (msgs, Just name) <- results] ;
1341 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1343 -- Fail if nothing good happened, else add warnings
1344 if null good_names then
1345 -- No lookup succeeded, so
1346 -- pick the first error message and report it
1347 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1348 -- while the other is "X is not in scope",
1349 -- we definitely want the former; but we might pick the latter
1350 do { addMessages (head errs_s) ; failM }
1351 else -- Add deprecation warnings
1352 mapM_ addMessages warns_s ;
1357 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1358 tcRnLookupName hsc_env name
1359 = initTcPrintErrors hsc_env iNTERACTIVE $
1360 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1361 tcRnLookupName' name
1363 -- To look up a name we have to look in the local environment (tcl_lcl)
1364 -- as well as the global environment, which is what tcLookup does.
1365 -- But we also want a TyThing, so we have to convert:
1367 tcRnLookupName' :: Name -> TcRn TyThing
1368 tcRnLookupName' name = do
1369 tcthing <- tcLookup name
1371 AGlobal thing -> return thing
1372 ATcId{tct_id=id} -> return (AnId id)
1373 _ -> panic "tcRnLookupName'"
1375 tcRnGetInfo :: HscEnv
1377 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1379 -- Used to implemnent :info in GHCi
1381 -- Look up a RdrName and return all the TyThings it might be
1382 -- A capitalised RdrName is given to us in the DataName namespace,
1383 -- but we want to treat it as *both* a data constructor
1384 -- *and* as a type or class constructor;
1385 -- hence the call to dataTcOccs, and we return up to two results
1386 tcRnGetInfo hsc_env name
1387 = initTcPrintErrors hsc_env iNTERACTIVE $
1388 let ictxt = hsc_IC hsc_env in
1389 setInteractiveContext hsc_env ictxt $ do
1391 -- Load the interface for all unqualified types and classes
1392 -- That way we will find all the instance declarations
1393 -- (Packages have not orphan modules, and we assume that
1394 -- in the home package all relevant modules are loaded.)
1395 loadUnqualIfaces ictxt
1397 thing <- tcRnLookupName' name
1398 fixity <- lookupFixityRn name
1399 ispecs <- lookupInsts thing
1400 return (thing, fixity, ispecs)
1402 lookupInsts :: TyThing -> TcM [Instance]
1403 lookupInsts (AClass cls)
1404 = do { inst_envs <- tcGetInstEnvs
1405 ; return (classInstances inst_envs cls) }
1407 lookupInsts (ATyCon tc)
1408 = do { eps <- getEps -- Load all instances for all classes that are
1409 -- in the type environment (which are all the ones
1410 -- we've seen in any interface file so far)
1411 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1413 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1414 , let dfun = instanceDFunId ispec
1417 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1418 tc_name = tyConName tc
1420 lookupInsts other = return []
1422 loadUnqualIfaces :: InteractiveContext -> TcM ()
1423 -- Load the home module for everything that is in scope unqualified
1424 -- This is so that we can accurately report the instances for
1426 loadUnqualIfaces ictxt
1428 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1430 unqual_mods = [ nameModule name
1431 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1432 let name = gre_name gre,
1433 not (isInternalName name),
1434 isTcOcc (nameOccName name), -- Types and classes only
1435 unQualOK gre ] -- In scope unqualified
1436 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1440 %************************************************************************
1444 %************************************************************************
1447 rnDump :: SDoc -> TcRn ()
1448 -- Dump, with a banner, if -ddump-rn
1449 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1451 tcDump :: TcGblEnv -> TcRn ()
1453 = do { dflags <- getDOpts ;
1455 -- Dump short output if -ddump-types or -ddump-tc
1456 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1457 (dumpTcRn short_dump) ;
1459 -- Dump bindings if -ddump-tc
1460 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1463 short_dump = pprTcGblEnv env
1464 full_dump = pprLHsBinds (tcg_binds env)
1465 -- NB: foreign x-d's have undefined's in their types;
1466 -- hence can't show the tc_fords
1469 = do { dflags <- getDOpts ;
1470 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1471 (dumpTcRn (pprModGuts mod_guts)) ;
1473 -- Dump bindings if -ddump-tc
1474 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1476 full_dump = pprCoreBindings (mg_binds mod_guts)
1478 -- It's unpleasant having both pprModGuts and pprModDetails here
1479 pprTcGblEnv :: TcGblEnv -> SDoc
1480 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1482 tcg_fam_insts = fam_insts,
1484 tcg_imports = imports })
1485 = vcat [ ppr_types insts type_env
1486 , ppr_tycons fam_insts type_env
1488 , ppr_fam_insts fam_insts
1489 , vcat (map ppr rules)
1490 , ppr_gen_tycons (typeEnvTyCons type_env)
1491 , ptext (sLit "Dependent modules:") <+>
1492 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1493 , ptext (sLit "Dependent packages:") <+>
1494 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1495 where -- The two uses of sortBy are just to reduce unnecessary
1496 -- wobbling in testsuite output
1497 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1498 = (mod_name1 `stableModuleNameCmp` mod_name2)
1500 (is_boot1 `compare` is_boot2)
1502 pprModGuts :: ModGuts -> SDoc
1503 pprModGuts (ModGuts { mg_types = type_env,
1505 = vcat [ ppr_types [] type_env,
1508 ppr_types :: [Instance] -> TypeEnv -> SDoc
1509 ppr_types insts type_env
1510 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1512 dfun_ids = map instanceDFunId insts
1513 ids = [id | id <- typeEnvIds type_env, want_sig id]
1514 want_sig id | opt_PprStyle_Debug = True
1515 | otherwise = isLocalId id &&
1516 isExternalName (idName id) &&
1517 not (id `elem` dfun_ids)
1518 -- isLocalId ignores data constructors, records selectors etc.
1519 -- The isExternalName ignores local dictionary and method bindings
1520 -- that the type checker has invented. Top-level user-defined things
1521 -- have External names.
1523 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1524 ppr_tycons fam_insts type_env
1525 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1527 fi_tycons = map famInstTyCon fam_insts
1528 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1529 want_tycon tycon | opt_PprStyle_Debug = True
1530 | otherwise = not (isImplicitTyCon tycon) &&
1531 isExternalName (tyConName tycon) &&
1532 not (tycon `elem` fi_tycons)
1534 ppr_insts :: [Instance] -> SDoc
1535 ppr_insts [] = empty
1536 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1538 ppr_fam_insts :: [FamInst] -> SDoc
1539 ppr_fam_insts [] = empty
1540 ppr_fam_insts fam_insts =
1541 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1543 ppr_sigs :: [Var] -> SDoc
1545 -- Print type signatures; sort by OccName
1546 = vcat (map ppr_sig (sortLe le_sig ids))
1548 le_sig id1 id2 = getOccName id1 <= getOccName id2
1549 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1551 ppr_tydecls :: [TyCon] -> SDoc
1553 -- Print type constructor info; sort by OccName
1554 = vcat (map ppr_tycon (sortLe le_sig tycons))
1556 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1558 | isCoercionTyCon tycon = ptext (sLit "coercion") <+> ppr tycon
1559 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1561 ppr_rules :: [CoreRule] -> SDoc
1562 ppr_rules [] = empty
1563 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1564 nest 4 (pprRules rs),
1567 ppr_gen_tycons [] = empty
1568 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1569 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]