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?
323 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
325 mod_guts = ModGuts { mg_module = this_mod,
327 mg_used_names = emptyNameSet, -- ToDo: compute usage
328 mg_dir_imps = emptyModuleEnv, -- ??
329 mg_deps = noDependencies, -- ??
330 mg_exports = my_exports,
331 mg_types = final_type_env,
332 mg_insts = tcg_insts tcg_env,
333 mg_fam_insts = tcg_fam_insts tcg_env,
334 mg_inst_env = tcg_inst_env tcg_env,
335 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
337 mg_binds = core_binds,
340 mg_rdr_env = emptyGlobalRdrEnv,
341 mg_fix_env = emptyFixityEnv,
342 mg_warns = NoWarnings,
343 mg_foreign = NoStubs,
344 mg_hpc_info = emptyHpcInfo False,
345 mg_modBreaks = emptyModBreaks,
346 mg_vect_info = noVectInfo
349 tcCoreDump mod_guts ;
354 mkFakeGroup decls -- Rather clumsy; lots of unused fields
355 = emptyRdrGroup { hs_tyclds = decls }
359 %************************************************************************
361 Type-checking the top level of a module
363 %************************************************************************
366 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
367 -- Returns the variables free in the decls
368 -- Reason: solely to report unused imports and bindings
369 tcRnSrcDecls boot_iface decls
370 = do { -- Do all the declarations
371 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
373 -- Finish simplifying class constraints
375 -- tcSimplifyTop deals with constant or ambiguous InstIds.
376 -- How could there be ambiguous ones? They can only arise if a
377 -- top-level decl falls under the monomorphism restriction
378 -- and no subsequent decl instantiates its type.
380 -- We do this after checkMain, so that we use the type info
381 -- thaat checkMain adds
383 -- We do it with both global and local env in scope:
384 -- * the global env exposes the instances to tcSimplifyTop
385 -- * the local env exposes the local Ids to tcSimplifyTop,
386 -- so that we get better error messages (monomorphism restriction)
387 traceTc (text "Tc8") ;
388 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
390 -- Backsubstitution. This must be done last.
391 -- Even tcSimplifyTop may do some unification.
392 traceTc (text "Tc9") ;
393 let { (tcg_env, _) = tc_envs
394 ; TcGblEnv { tcg_type_env = type_env,
397 tcg_fords = fords } = tcg_env
398 ; all_binds = binds `unionBags` inst_binds } ;
400 failIfErrsM ; -- Don't zonk if there have been errors
401 -- It's a waste of time; and we may get debug warnings
402 -- about strangely-typed TyCons!
404 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
407 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
408 ; tcg_env' = tcg_env { tcg_binds = binds',
410 tcg_fords = fords' } } ;
412 setGlobalTypeEnv tcg_env' final_type_env
415 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
416 -- Loops around dealing with each top level inter-splice group
417 -- in turn, until it's dealt with the entire module
418 tc_rn_src_decls boot_details ds
419 = do { let { (first_group, group_tail) = findSplice ds } ;
420 -- If ds is [] we get ([], Nothing)
422 -- Deal with decls up to, but not including, the first splice
423 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
424 -- rnTopSrcDecls fails if there are any errors
426 (tcg_env, tcl_env) <- setGblEnv tcg_env $
427 tcTopSrcDecls boot_details rn_decls ;
429 -- If there is no splice, we're nearly done
430 setEnvs (tcg_env, tcl_env) $
432 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
433 return (tcg_env, tcl_env)
436 -- If there's a splice, we must carry on
437 Just (SpliceDecl splice_expr, rest_ds) -> do {
439 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
442 -- Rename the splice expression, and get its supporting decls
443 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
444 -- checkNoErrs: don't typecheck if renaming failed
445 rnDump (ppr rn_splice_expr) ;
447 -- Execute the splice
448 spliced_decls <- tcSpliceDecls rn_splice_expr ;
450 -- Glue them on the front of the remaining decls and loop
451 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
452 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
457 %************************************************************************
459 Compiling hs-boot source files, and
460 comparing the hi-boot interface with the real thing
462 %************************************************************************
465 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
466 tcRnHsBootDecls decls
467 = do { let { (first_group, group_tail) = findSplice decls }
470 Just stuff -> spliceInHsBootErr stuff
473 -- Rename the declarations
474 ; (tcg_env, HsGroup {
475 hs_tyclds = tycl_decls,
476 hs_instds = inst_decls,
477 hs_derivds = deriv_decls,
479 hs_defds = _, -- Todo: check no foreign decls, no rules,
480 hs_ruleds = _, -- no default decls and no annotation decls
482 hs_valds = val_binds }) <- rnTopSrcDecls first_group
483 ; setGblEnv tcg_env $ do {
486 -- Typecheck type/class decls
487 ; traceTc (text "Tc2")
488 ; tcg_env <- tcTyAndClassDecls emptyModDetails tycl_decls
489 ; setGblEnv tcg_env $ do {
491 -- Typecheck instance decls
492 ; traceTc (text "Tc3")
493 ; (tcg_env, inst_infos, _deriv_binds)
494 <- tcInstDecls1 tycl_decls inst_decls deriv_decls
495 ; setGblEnv tcg_env $ do {
497 -- Typecheck value declarations
498 ; traceTc (text "Tc5")
499 ; val_ids <- tcHsBootSigs val_binds
502 -- No simplification or zonking to do
503 ; traceTc (text "Tc7a")
504 ; gbl_env <- getGblEnv
506 -- Make the final type-env
507 -- Include the dfun_ids so that their type sigs
508 -- are written into the interface file
509 ; let { type_env0 = tcg_type_env gbl_env
510 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
511 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
512 ; dfun_ids = map iDFunId inst_infos }
513 ; setGlobalTypeEnv gbl_env type_env2
516 spliceInHsBootErr (SpliceDecl (L loc _), _)
517 = addErrAt loc (ptext (sLit "Splices are not allowed in hs-boot files"))
520 Once we've typechecked the body of the module, we want to compare what
521 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
524 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
525 -- Compare the hi-boot file for this module (if there is one)
526 -- with the type environment we've just come up with
527 -- In the common case where there is no hi-boot file, the list
528 -- of boot_names is empty.
530 -- The bindings we return give bindings for the dfuns defined in the
531 -- hs-boot file, such as $fbEqT = $fEqT
534 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
535 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
536 tcg_type_env = local_type_env, tcg_exports = local_exports })
537 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
538 md_types = boot_type_env, md_exports = boot_exports })
539 | isHsBoot hs_src -- Current module is already a hs-boot file!
543 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
546 -- Check the exports of the boot module, one by one
547 ; mapM_ check_export boot_exports
549 -- Check for no family instances
550 ; unless (null boot_fam_insts) $
551 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
552 "instances in boot files yet...")
553 -- FIXME: Why? The actual comparison is not hard, but what would
554 -- be the equivalent to the dfun bindings returned for class
555 -- instances? We can't easily equate tycons...
557 -- Check instance declarations
558 ; mb_dfun_prs <- mapM check_inst boot_insts
559 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
560 final_type_env = extendTypeEnvWithIds local_type_env boot_dfuns
561 dfun_prs = catMaybes mb_dfun_prs
562 boot_dfuns = map fst dfun_prs
563 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
564 | (boot_dfun, dfun) <- dfun_prs ]
567 ; setGlobalTypeEnv tcg_env' final_type_env }
569 check_export boot_avail -- boot_avail is exported by the boot iface
570 | name `elem` dfun_names = return ()
571 | isWiredInName name = return () -- No checking for wired-in names. In particular,
572 -- 'error' is handled by a rather gross hack
573 -- (see comments in GHC.Err.hs-boot)
575 -- Check that the actual module exports the same thing
576 | not (null missing_names)
577 = addErrAt (nameSrcSpan (head missing_names))
578 (missingBootThing (head missing_names) "exported by")
580 -- If the boot module does not *define* the thing, we are done
581 -- (it simply re-exports it, and names match, so nothing further to do)
582 | isNothing mb_boot_thing = return ()
584 -- Check that the actual module also defines the thing, and
585 -- then compare the definitions
586 | Just real_thing <- lookupTypeEnv local_type_env name,
587 Just boot_thing <- mb_boot_thing
588 = when (not (checkBootDecl boot_thing real_thing))
589 $ addErrAt (nameSrcSpan (getName boot_thing))
590 (let boot_decl = tyThingToIfaceDecl
591 (fromJust mb_boot_thing)
592 real_decl = tyThingToIfaceDecl real_thing
593 in bootMisMatch real_thing boot_decl real_decl)
596 = addErrTc (missingBootThing name "defined in")
598 name = availName boot_avail
599 mb_boot_thing = lookupTypeEnv boot_type_env name
600 missing_names = case lookupNameEnv local_export_env name of
602 Just avail -> availNames boot_avail `minusList` availNames avail
604 dfun_names = map getName boot_insts
606 local_export_env :: NameEnv AvailInfo
607 local_export_env = availsToNameEnv local_exports
609 check_inst :: Instance -> TcM (Maybe (Id, Id))
610 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
612 = case [dfun | inst <- local_insts,
613 let dfun = instanceDFunId inst,
614 idType dfun `tcEqType` boot_inst_ty ] of
615 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
616 (dfun:_) -> return (Just (local_boot_dfun, dfun))
618 boot_dfun = instanceDFunId boot_inst
619 boot_inst_ty = idType boot_dfun
620 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
623 -- This has to compare the TyThing from the .hi-boot file to the TyThing
624 -- in the current source file. We must be careful to allow alpha-renaming
625 -- where appropriate, and also the boot declaration is allowed to omit
626 -- constructors and class methods.
628 -- See rnfail055 for a good test of this stuff.
630 checkBootDecl :: TyThing -> TyThing -> Bool
632 checkBootDecl (AnId id1) (AnId id2)
634 (idType id1 `tcEqType` idType id2)
636 checkBootDecl (ATyCon tc1) (ATyCon tc2)
637 | isSynTyCon tc1 && isSynTyCon tc2
639 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
640 env = rnBndrs2 env0 tvs1 tvs2
642 eqSynRhs (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
643 = tcEqTypeX env k1 k2
644 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
645 = tcEqTypeX env t1 t2
647 equalLength tvs1 tvs2 &&
648 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
650 | isAlgTyCon tc1 && isAlgTyCon tc2
652 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2)
653 && eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
655 | isForeignTyCon tc1 && isForeignTyCon tc2
656 = tyConExtName tc1 == tyConExtName tc2
658 env0 = mkRnEnv2 emptyInScopeSet
660 eqAlgRhs AbstractTyCon _ = True
661 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
662 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
663 eqListBy eqCon (data_cons tc1) (data_cons tc2)
664 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
665 eqCon (data_con tc1) (data_con tc2)
669 = dataConName c1 == dataConName c2
670 && dataConIsInfix c1 == dataConIsInfix c2
671 && dataConStrictMarks c1 == dataConStrictMarks c2
672 && dataConFieldLabels c1 == dataConFieldLabels c2
673 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
674 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
675 env = rnBndrs2 env0 tvs1 tvs2
677 equalLength tvs1 tvs2 &&
678 eqListBy (tcEqPredX env)
679 (dataConEqTheta c1 ++ dataConDictTheta c1)
680 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
681 eqListBy (tcEqTypeX env)
682 (dataConOrigArgTys c1)
683 (dataConOrigArgTys c2)
685 checkBootDecl (AClass c1) (AClass c2)
687 (clas_tyvars1, clas_fds1, sc_theta1, _, _, op_stuff1)
688 = classExtraBigSig c1
689 (clas_tyvars2, clas_fds2, sc_theta2, _, _, op_stuff2)
690 = classExtraBigSig c2
692 env0 = mkRnEnv2 emptyInScopeSet
693 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
695 eqSig (id1, def_meth1) (id2, def_meth2)
696 = idName id1 == idName id2 &&
697 tcEqTypeX env op_ty1 op_ty2
699 (_, rho_ty1) = splitForAllTys (idType id1)
700 op_ty1 = funResultTy rho_ty1
701 (_, rho_ty2) = splitForAllTys (idType id2)
702 op_ty2 = funResultTy rho_ty2
704 eqFD (as1,bs1) (as2,bs2) =
705 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
706 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
708 equalLength clas_tyvars1 clas_tyvars2 &&
709 eqListBy eqFD clas_fds1 clas_fds2 &&
710 (null sc_theta1 && null op_stuff1
712 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
713 eqListBy eqSig op_stuff1 op_stuff2)
715 checkBootDecl (ADataCon dc1) (ADataCon dc2)
716 = pprPanic "checkBootDecl" (ppr dc1)
718 checkBootDecl _ _ = False -- probably shouldn't happen
721 missingBootThing thing what
722 = ppr thing <+> ptext (sLit "is exported by the hs-boot file, but not")
723 <+> text what <+> ptext (sLit "the module")
725 bootMisMatch thing boot_decl real_decl
726 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
727 ptext (sLit "Main module:") <+> ppr real_decl,
728 ptext (sLit "Boot file: ") <+> ppr boot_decl]
732 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
736 %************************************************************************
738 Type-checking the top level of a module
740 %************************************************************************
742 tcRnGroup takes a bunch of top-level source-code declarations, and
744 * gets supporting declarations from interface files
747 * and augments the TcGblEnv with the results
749 In Template Haskell it may be called repeatedly for each group of
750 declarations. It expects there to be an incoming TcGblEnv in the
751 monad; it augments it and returns the new TcGblEnv.
754 ------------------------------------------------
755 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
756 -- Fails if there are any errors
758 = do { -- Rename the source decls
759 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
761 -- save the renamed syntax, if we want it
763 | Just grp <- tcg_rn_decls tcg_env
764 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
768 -- Dump trace of renaming part
769 rnDump (ppr rn_decls) ;
771 return (tcg_env', rn_decls)
774 ------------------------------------------------
775 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
776 tcTopSrcDecls boot_details
777 (HsGroup { hs_tyclds = tycl_decls,
778 hs_instds = inst_decls,
779 hs_derivds = deriv_decls,
780 hs_fords = foreign_decls,
781 hs_defds = default_decls,
782 hs_annds = annotation_decls,
783 hs_ruleds = rule_decls,
784 hs_valds = val_binds })
785 = do { -- Type-check the type and class decls, and all imported decls
786 -- The latter come in via tycl_decls
787 traceTc (text "Tc2") ;
789 tcg_env <- tcTyAndClassDecls boot_details tycl_decls ;
790 -- If there are any errors, tcTyAndClassDecls fails here
792 setGblEnv tcg_env $ do {
793 -- Source-language instances, including derivings,
794 -- and import the supporting declarations
795 traceTc (text "Tc3") ;
796 (tcg_env, inst_infos, deriv_binds)
797 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
798 setGblEnv tcg_env $ do {
800 -- Foreign import declarations next. No zonking necessary
801 -- here; we can tuck them straight into the global environment.
802 traceTc (text "Tc4") ;
803 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
804 tcExtendGlobalValEnv fi_ids $ do {
806 -- Default declarations
807 traceTc (text "Tc4a") ;
808 default_tys <- tcDefaults default_decls ;
809 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
811 -- Value declarations next
812 -- We also typecheck any extra binds that came out
813 -- of the "deriving" process (deriv_binds)
814 traceTc (text "Tc5") ;
815 (tc_val_binds, tcl_env) <- tcTopBinds val_binds ;
816 setLclTypeEnv tcl_env $ do {
818 -- Now GHC-generated derived bindings and generics.
819 -- Do not generate warnings from compiler-generated code.
820 (tc_deriv_binds, tcl_env) <- discardWarnings $
821 tcTopBinds deriv_binds ;
823 -- Second pass over class and instance declarations,
824 traceTc (text "Tc6") ;
825 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $ tcInstDecls2 tycl_decls inst_infos ;
826 showLIE (text "after instDecls2") ;
829 -- They need to be zonked, so we return them
830 traceTc (text "Tc7") ;
831 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
834 annotations <- tcAnnotations annotation_decls ;
837 rules <- tcRules rule_decls ;
840 traceTc (text "Tc7a") ;
841 tcg_env <- getGblEnv ;
842 let { all_binds = tc_val_binds `unionBags`
843 tc_deriv_binds `unionBags`
844 inst_binds `unionBags`
847 -- Extend the GblEnv with the (as yet un-zonked)
848 -- bindings, rules, foreign decls
849 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
850 tcg_rules = tcg_rules tcg_env ++ rules,
851 tcg_anns = tcg_anns tcg_env ++ annotations,
852 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
853 return (tcg_env', tcl_env)
858 %************************************************************************
862 %************************************************************************
865 checkMain :: TcM TcGblEnv
866 -- If we are in module Main, check that 'main' is defined.
868 = do { tcg_env <- getGblEnv ;
870 check_main dflags tcg_env
873 check_main dflags tcg_env
875 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
879 = do { mb_main <- lookupSrcOcc_maybe main_fn
880 -- Check that 'main' is in scope
881 -- It might be imported from another module!
883 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
888 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
889 ; let loc = srcLocSpan (getSrcLoc main_name)
890 ; ioTyCon <- tcLookupTyCon ioTyConName
891 ; (main_expr, res_ty)
892 <- addErrCtxt mainCtxt $
893 withBox liftedTypeKind $ \res_ty ->
894 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
896 -- See Note [Root-main Id]
897 -- Construct the binding
898 -- :Main.main :: IO res_ty = runMainIO res_ty main
899 ; run_main_id <- tcLookupId runMainIOName
900 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
901 (mkVarOccFS (fsLit "main"))
902 (getSrcSpan main_name)
903 ; root_main_id = Id.mkExportedLocalId root_main_name
904 (mkTyConApp ioTyCon [res_ty])
905 ; co = mkWpTyApps [res_ty]
906 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
907 ; main_bind = noLoc (VarBind root_main_id rhs) }
909 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
911 tcg_dus = tcg_dus tcg_env
912 `plusDU` usesOnly (unitFV main_name)
913 -- Record the use of 'main', so that we don't
914 -- complain about it being defined but not used
918 mod = tcg_mod tcg_env
919 main_mod = mainModIs dflags
920 main_fn = getMainFun dflags
922 complain_no_main | ghcLink dflags == LinkInMemory = return ()
923 | otherwise = failWithTc noMainMsg
924 -- In interactive mode, don't worry about the absence of 'main'
925 -- In other modes, fail altogether, so that we don't go on
926 -- and complain a second time when processing the export list.
928 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
929 noMainMsg = ptext (sLit "The") <+> pp_main_fn
930 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
931 pp_main_fn | main_fn == main_RDR_Unqual = ptext (sLit "function") <+> quotes (ppr main_fn)
932 | otherwise = ptext (sLit "main function") <+> quotes (ppr main_fn)
938 The function that the RTS invokes is always :Main.main, which we call
939 root_main_id. (Because GHC allows the user to have a module not
940 called Main as the main module, we can't rely on the main function
941 being called "Main.main". That's why root_main_id has a fixed module
944 This is unusual: it's a LocalId whose Name has a Module from another
945 module. Tiresomely, we must filter it out again in MkIface, les we
946 get two defns for 'main' in the interface file!
949 %*********************************************************
953 %*********************************************************
957 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
958 setInteractiveContext hsc_env icxt thing_inside
959 = let -- Initialise the tcg_inst_env with instances from all home modules.
960 -- This mimics the more selective call to hptInstances in tcRnModule.
961 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
963 updGblEnv (\env -> env {
964 tcg_rdr_env = ic_rn_gbl_env icxt,
965 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
966 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
970 tcExtendGhciEnv (ic_tmp_ids icxt) $
971 -- tcExtendGhciEnv does lots:
972 -- - it extends the local type env (tcl_env) with the given Ids,
973 -- - it extends the local rdr env (tcl_rdr) with the Names from
975 -- - it adds the free tyvars of the Ids to the tcl_tyvars
978 -- later ids in ic_tmp_ids must shadow earlier ones with the same
979 -- OccName, and tcExtendIdEnv implements this behaviour.
981 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
988 -> InteractiveContext
990 -> IO (Messages, Maybe ([Id], LHsExpr Id))
991 -- The returned [Id] is the list of new Ids bound by
992 -- this statement. It can be used to extend the
993 -- InteractiveContext via extendInteractiveContext.
995 -- The returned TypecheckedHsExpr is of type IO [ () ],
996 -- a list of the bound values, coerced to ().
998 tcRnStmt hsc_env ictxt rdr_stmt
999 = initTcPrintErrors hsc_env iNTERACTIVE $
1000 setInteractiveContext hsc_env ictxt $ do {
1002 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
1003 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
1004 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
1006 rnDump (ppr rn_stmt) ;
1008 -- The real work is done here
1009 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1010 zonked_expr <- zonkTopLExpr tc_expr ;
1011 zonked_ids <- zonkTopBndrs bound_ids ;
1013 -- None of the Ids should be of unboxed type, because we
1014 -- cast them all to HValues in the end!
1015 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1017 traceTc (text "tcs 1") ;
1018 let { global_ids = map globaliseAndTidy zonked_ids } ;
1020 {- ---------------------------------------------
1021 At one stage I removed any shadowed bindings from the type_env;
1022 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1023 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1025 Prelude> let f n = n * 2 :: Int
1026 Prelude> fName <- runQ [| f |]
1027 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1029 Prelude> let f n = n * 3 :: Int
1030 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1031 In the last line we use 'fName', which resolves to the *first* 'f'
1032 in scope. If we delete it from the type env, GHCi crashes because
1033 it doesn't expect that.
1035 Hence this code is commented out
1037 -------------------------------------------------- -}
1039 dumpOptTcRn Opt_D_dump_tc
1040 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1041 text "Typechecked expr" <+> ppr zonked_expr]) ;
1043 return (global_ids, zonked_expr)
1046 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1047 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1049 globaliseAndTidy :: Id -> Id
1050 globaliseAndTidy id -- Note [Interactively-bound Ids in GHCi]
1051 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
1053 tidy_type = tidyTopType (idType id)
1056 Note [Interactively-bound Ids in GHCi]
1057 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1058 The Ids bound by previous Stmts in Template Haskell are currently
1060 b) with an Internal Name (not External)
1061 c) and a tidied type
1063 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1064 compile an expression using these ids later, the byte code
1065 generator will consider the occurrences to be free rather than
1068 (b) They retain their Internal names becuase we don't have a suitable
1069 Module to name them with. We could revisit this choice.
1071 (c) Their types are tidied. This is important, because :info may ask
1072 to look at them, and :info expects the things it looks up to have
1076 --------------------------------------------------------------------------
1077 Typechecking Stmts in GHCi
1079 Here is the grand plan, implemented in tcUserStmt
1081 What you type The IO [HValue] that hscStmt returns
1082 ------------- ------------------------------------
1083 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1086 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1089 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1090 [NB: result not printed] bindings: [it]
1092 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1093 result showable) bindings: [it]
1095 expr (of non-IO type,
1096 result not showable) ==> error
1100 ---------------------------
1101 type PlanResult = ([Id], LHsExpr Id)
1102 type Plan = TcM PlanResult
1104 runPlans :: [Plan] -> TcM PlanResult
1105 -- Try the plans in order. If one fails (by raising an exn), try the next.
1106 -- If one succeeds, take it.
1107 runPlans [] = panic "runPlans"
1109 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1111 --------------------
1112 mkPlan :: LStmt Name -> TcM PlanResult
1113 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1114 = do { uniq <- newUnique -- is treated very specially
1115 ; let fresh_it = itName uniq
1116 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1117 matches = [mkMatch [] expr emptyLocalBinds]
1118 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1119 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1120 (HsVar bindIOName) noSyntaxExpr
1121 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1122 (HsVar thenIOName) placeHolderType
1125 -- [it <- e; print it] but not if it::()
1127 -- [let it = e; print it]
1128 ; runPlans [ -- Plan A
1129 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1130 ; it_ty <- zonkTcType (idType it_id)
1131 ; when (isUnitTy it_ty) failM
1134 -- Plan B; a naked bind statment
1135 tcGhciStmts [bind_stmt],
1137 -- Plan C; check that the let-binding is typeable all by itself.
1138 -- If not, fail; if so, try to print it.
1139 -- The two-step process avoids getting two errors: one from
1140 -- the expression itself, and one from the 'print it' part
1141 -- This two-step story is very clunky, alas
1142 do { checkNoErrs (tcGhciStmts [let_stmt])
1143 --- checkNoErrs defeats the error recovery of let-bindings
1144 ; tcGhciStmts [let_stmt, print_it] }
1147 mkPlan stmt@(L loc (BindStmt {}))
1148 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1149 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1150 (HsVar thenIOName) placeHolderType
1152 ; print_bind_result <- doptM Opt_PrintBindResult
1153 ; let print_plan = do
1154 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1155 ; v_ty <- zonkTcType (idType v_id)
1156 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1160 -- [stmt; print v] but not if v::()
1162 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1163 [tcGhciStmts [stmt]])
1167 = tcGhciStmts [stmt]
1169 ---------------------------
1170 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1172 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1173 ret_id <- tcLookupId returnIOName ; -- return @ IO
1175 ret_ty = mkListTy unitTy ;
1176 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1177 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1179 names = map unLoc (collectLStmtsBinders stmts) ;
1181 -- mk_return builds the expression
1182 -- returnIO @ [()] [coerce () x, .., coerce () z]
1184 -- Despite the inconvenience of building the type applications etc,
1185 -- this *has* to be done in type-annotated post-typecheck form
1186 -- because we are going to return a list of *polymorphic* values
1187 -- coerced to type (). If we built a *source* stmt
1188 -- return [coerce x, ..., coerce z]
1189 -- then the type checker would instantiate x..z, and we wouldn't
1190 -- get their *polymorphic* values. (And we'd get ambiguity errs
1191 -- if they were overloaded, since they aren't applied to anything.)
1192 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1193 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1194 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1198 -- OK, we're ready to typecheck the stmts
1199 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1200 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1201 mapM tcLookupId names ;
1202 -- Look up the names right in the middle,
1203 -- where they will all be in scope
1205 -- Simplify the context
1206 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1207 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1208 -- checkNoErrs ensures that the plan fails if context redn fails
1210 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1211 return (ids, mkHsDictLet const_binds $
1212 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1217 tcRnExpr just finds the type of an expression
1221 -> InteractiveContext
1223 -> IO (Messages, Maybe Type)
1224 tcRnExpr hsc_env ictxt rdr_expr
1225 = initTcPrintErrors hsc_env iNTERACTIVE $
1226 setInteractiveContext hsc_env ictxt $ do {
1228 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1231 -- Now typecheck the expression;
1232 -- it might have a rank-2 type (e.g. :t runST)
1233 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1234 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1235 tcSimplifyInteractive lie_top ;
1237 let { all_expr_ty = mkForAllTys qtvs $
1238 mkFunTys (map (idType . instToId) dict_insts) $
1240 zonkTcType all_expr_ty
1243 smpl_doc = ptext (sLit "main expression")
1246 tcRnType just finds the kind of a type
1250 -> InteractiveContext
1252 -> IO (Messages, Maybe Kind)
1253 tcRnType hsc_env ictxt rdr_type
1254 = initTcPrintErrors hsc_env iNTERACTIVE $
1255 setInteractiveContext hsc_env ictxt $ do {
1257 rn_type <- rnLHsType doc rdr_type ;
1260 -- Now kind-check the type
1261 (ty', kind) <- kcHsType rn_type ;
1265 doc = ptext (sLit "In GHCi input")
1271 %************************************************************************
1273 More GHCi stuff, to do with browsing and getting info
1275 %************************************************************************
1279 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1280 -- a package module with an interface on disk. If neither of these is
1281 -- true, then the result will be an error indicating the interface
1282 -- could not be found.
1283 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1284 getModuleExports hsc_env mod
1287 checkMods = ic_toplev_scope ic ++ ic_exports ic
1289 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1291 -- Get the export avail info and also load all orphan and family-instance
1292 -- modules. Finally, check that the family instances of all modules in the
1293 -- interactive context are consistent (these modules are in the second
1295 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1296 tcGetModuleExports mod directlyImpMods
1297 = do { let doc = ptext (sLit "context for compiling statements")
1298 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1300 -- Load any orphan-module and family instance-module
1301 -- interfaces, so their instances are visible.
1302 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1303 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1305 -- Check that the family instances of all directly loaded
1306 -- modules are consistent.
1307 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1309 ; ifaceExportNames (mi_exports iface)
1312 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1313 tcRnLookupRdrName hsc_env rdr_name
1314 = initTcPrintErrors hsc_env iNTERACTIVE $
1315 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1316 lookup_rdr_name rdr_name
1318 lookup_rdr_name rdr_name = do {
1319 -- If the identifier is a constructor (begins with an
1320 -- upper-case letter), then we need to consider both
1321 -- constructor and type class identifiers.
1322 let { rdr_names = dataTcOccs rdr_name } ;
1324 -- results :: [Either Messages Name]
1325 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1327 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1328 -- The successful lookups will be (Just name)
1329 let { (warns_s, good_names) = unzip [ (msgs, name)
1330 | (msgs, Just name) <- results] ;
1331 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1333 -- Fail if nothing good happened, else add warnings
1334 if null good_names then
1335 -- No lookup succeeded, so
1336 -- pick the first error message and report it
1337 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1338 -- while the other is "X is not in scope",
1339 -- we definitely want the former; but we might pick the latter
1340 do { addMessages (head errs_s) ; failM }
1341 else -- Add deprecation warnings
1342 mapM_ addMessages warns_s ;
1347 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1348 tcRnLookupName hsc_env name
1349 = initTcPrintErrors hsc_env iNTERACTIVE $
1350 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1351 tcRnLookupName' name
1353 -- To look up a name we have to look in the local environment (tcl_lcl)
1354 -- as well as the global environment, which is what tcLookup does.
1355 -- But we also want a TyThing, so we have to convert:
1357 tcRnLookupName' :: Name -> TcRn TyThing
1358 tcRnLookupName' name = do
1359 tcthing <- tcLookup name
1361 AGlobal thing -> return thing
1362 ATcId{tct_id=id} -> return (AnId id)
1363 _ -> panic "tcRnLookupName'"
1365 tcRnGetInfo :: HscEnv
1367 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1369 -- Used to implemnent :info in GHCi
1371 -- Look up a RdrName and return all the TyThings it might be
1372 -- A capitalised RdrName is given to us in the DataName namespace,
1373 -- but we want to treat it as *both* a data constructor
1374 -- *and* as a type or class constructor;
1375 -- hence the call to dataTcOccs, and we return up to two results
1376 tcRnGetInfo hsc_env name
1377 = initTcPrintErrors hsc_env iNTERACTIVE $
1378 let ictxt = hsc_IC hsc_env in
1379 setInteractiveContext hsc_env ictxt $ do
1381 -- Load the interface for all unqualified types and classes
1382 -- That way we will find all the instance declarations
1383 -- (Packages have not orphan modules, and we assume that
1384 -- in the home package all relevant modules are loaded.)
1385 loadUnqualIfaces ictxt
1387 thing <- tcRnLookupName' name
1388 fixity <- lookupFixityRn name
1389 ispecs <- lookupInsts thing
1390 return (thing, fixity, ispecs)
1392 lookupInsts :: TyThing -> TcM [Instance]
1393 lookupInsts (AClass cls)
1394 = do { inst_envs <- tcGetInstEnvs
1395 ; return (classInstances inst_envs cls) }
1397 lookupInsts (ATyCon tc)
1398 = do { eps <- getEps -- Load all instances for all classes that are
1399 -- in the type environment (which are all the ones
1400 -- we've seen in any interface file so far)
1401 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1403 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1404 , let dfun = instanceDFunId ispec
1407 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1408 tc_name = tyConName tc
1410 lookupInsts other = return []
1412 loadUnqualIfaces :: InteractiveContext -> TcM ()
1413 -- Load the home module for everything that is in scope unqualified
1414 -- This is so that we can accurately report the instances for
1416 loadUnqualIfaces ictxt
1418 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1420 unqual_mods = [ nameModule name
1421 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1422 let name = gre_name gre,
1423 not (isInternalName name),
1424 isTcOcc (nameOccName name), -- Types and classes only
1425 unQualOK gre ] -- In scope unqualified
1426 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1430 %************************************************************************
1434 %************************************************************************
1437 rnDump :: SDoc -> TcRn ()
1438 -- Dump, with a banner, if -ddump-rn
1439 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1441 tcDump :: TcGblEnv -> TcRn ()
1443 = do { dflags <- getDOpts ;
1445 -- Dump short output if -ddump-types or -ddump-tc
1446 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1447 (dumpTcRn short_dump) ;
1449 -- Dump bindings if -ddump-tc
1450 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1453 short_dump = pprTcGblEnv env
1454 full_dump = pprLHsBinds (tcg_binds env)
1455 -- NB: foreign x-d's have undefined's in their types;
1456 -- hence can't show the tc_fords
1459 = do { dflags <- getDOpts ;
1460 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1461 (dumpTcRn (pprModGuts mod_guts)) ;
1463 -- Dump bindings if -ddump-tc
1464 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1466 full_dump = pprCoreBindings (mg_binds mod_guts)
1468 -- It's unpleasant having both pprModGuts and pprModDetails here
1469 pprTcGblEnv :: TcGblEnv -> SDoc
1470 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1472 tcg_fam_insts = fam_insts,
1474 tcg_imports = imports })
1475 = vcat [ ppr_types insts type_env
1476 , ppr_tycons fam_insts type_env
1478 , ppr_fam_insts fam_insts
1479 , vcat (map ppr rules)
1480 , ppr_gen_tycons (typeEnvTyCons type_env)
1481 , ptext (sLit "Dependent modules:") <+>
1482 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1483 , ptext (sLit "Dependent packages:") <+>
1484 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1485 where -- The two uses of sortBy are just to reduce unnecessary
1486 -- wobbling in testsuite output
1487 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1488 = (mod_name1 `stableModuleNameCmp` mod_name2)
1490 (is_boot1 `compare` is_boot2)
1492 pprModGuts :: ModGuts -> SDoc
1493 pprModGuts (ModGuts { mg_types = type_env,
1495 = vcat [ ppr_types [] type_env,
1498 ppr_types :: [Instance] -> TypeEnv -> SDoc
1499 ppr_types insts type_env
1500 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1502 dfun_ids = map instanceDFunId insts
1503 ids = [id | id <- typeEnvIds type_env, want_sig id]
1504 want_sig id | opt_PprStyle_Debug = True
1505 | otherwise = isLocalId id &&
1506 isExternalName (idName id) &&
1507 not (id `elem` dfun_ids)
1508 -- isLocalId ignores data constructors, records selectors etc.
1509 -- The isExternalName ignores local dictionary and method bindings
1510 -- that the type checker has invented. Top-level user-defined things
1511 -- have External names.
1513 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1514 ppr_tycons fam_insts type_env
1515 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1517 fi_tycons = map famInstTyCon fam_insts
1518 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1519 want_tycon tycon | opt_PprStyle_Debug = True
1520 | otherwise = not (isImplicitTyCon tycon) &&
1521 isExternalName (tyConName tycon) &&
1522 not (tycon `elem` fi_tycons)
1524 ppr_insts :: [Instance] -> SDoc
1525 ppr_insts [] = empty
1526 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1528 ppr_fam_insts :: [FamInst] -> SDoc
1529 ppr_fam_insts [] = empty
1530 ppr_fam_insts fam_insts =
1531 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1533 ppr_sigs :: [Var] -> SDoc
1535 -- Print type signatures; sort by OccName
1536 = vcat (map ppr_sig (sortLe le_sig ids))
1538 le_sig id1 id2 = getOccName id1 <= getOccName id2
1539 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1541 ppr_tydecls :: [TyCon] -> SDoc
1543 -- Print type constructor info; sort by OccName
1544 = vcat (map ppr_tycon (sortLe le_sig tycons))
1546 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1548 | isCoercionTyCon tycon = ptext (sLit "coercion") <+> ppr tycon
1549 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1551 ppr_rules :: [CoreRule] -> SDoc
1552 ppr_rules [] = empty
1553 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1554 nest 4 (pprRules rs),
1557 ppr_gen_tycons [] = empty
1558 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1559 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]