2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
5 \section[TcModule]{Typechecking a whole module}
9 -- The above warning supression flag is a temporary kludge.
10 -- While working on this module you are encouraged to remove it and fix
11 -- any warnings in the module. See
12 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
17 tcRnStmt, tcRnExpr, tcRnType,
30 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
59 import TcUnify ( withBox )
85 import Data.List ( sortBy )
97 import {- Kind parts of -} Type
99 import Foreign.Ptr( Ptr )
108 import Data.Maybe ( isJust )
110 #include "HsVersions.h"
115 %************************************************************************
117 Typecheck and rename a module
119 %************************************************************************
125 -> Bool -- True <=> save renamed syntax
126 -> Located (HsModule RdrName)
127 -> IO (Messages, Maybe TcGblEnv)
129 tcRnModule hsc_env hsc_src save_rn_syntax
130 (L loc (HsModule maybe_mod export_ies
131 import_decls local_decls mod_deprec
132 module_info maybe_doc))
133 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
135 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
136 this_mod = case maybe_mod of
137 Nothing -> mAIN -- 'module M where' is omitted
138 Just (L _ mod) -> mkModule this_pkg mod } ;
141 initTc hsc_env hsc_src save_rn_syntax this_mod $
143 do { -- Deal with imports;
144 tcg_env <- tcRnImports hsc_env this_mod import_decls ;
145 setGblEnv tcg_env $ do {
147 -- Load the hi-boot interface for this module, if any
148 -- We do this now so that the boot_names can be passed
149 -- to tcTyAndClassDecls, because the boot_names are
150 -- automatically considered to be loop breakers
152 -- Do this *after* tcRnImports, so that we know whether
153 -- a module that we import imports us; and hence whether to
154 -- look for a hi-boot file
155 boot_iface <- tcHiBootIface hsc_src this_mod ;
157 -- Rename and type check the declarations
158 traceRn (text "rn1a") ;
159 tcg_env <- if isHsBoot hsc_src then
160 tcRnHsBootDecls local_decls
162 tcRnSrcDecls boot_iface local_decls ;
163 setGblEnv tcg_env $ do {
165 -- Report the use of any deprecated things
166 -- We do this *before* processsing the export list so
167 -- that we don't bleat about re-exporting a deprecated
168 -- thing (especially via 'module Foo' export item)
169 -- That is, only uses in the *body* of the module are complained about
170 traceRn (text "rn3") ;
171 failIfErrsM ; -- finishWarnings crashes sometimes
172 -- as a result of typechecker repairs (e.g. unboundNames)
173 tcg_env <- finishWarnings (hsc_dflags hsc_env) mod_deprec tcg_env ;
175 -- Process the export list
176 traceRn (text "rn4a: before exports");
177 tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ;
178 traceRn (text "rn4b: after exportss") ;
180 -- Compare the hi-boot iface (if any) with the real thing
181 -- Must be done after processing the exports
182 tcg_env <- checkHiBootIface tcg_env boot_iface ;
184 -- The new type env is already available to stuff slurped from
185 -- interface files, via TcEnv.updateGlobalTypeEnv
186 -- It's important that this includes the stuff in checkHiBootIface,
187 -- because the latter might add new bindings for boot_dfuns,
188 -- which may be mentioned in imported unfoldings
190 -- Rename the Haddock documentation
191 tcg_env <- rnHaddock module_info maybe_doc tcg_env ;
193 -- Report unused names
194 reportUnusedNames export_ies tcg_env ;
196 -- Dump output and return
203 %************************************************************************
207 %************************************************************************
210 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
211 tcRnImports hsc_env this_mod import_decls
212 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
214 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
215 ; dep_mods = imp_dep_mods imports
217 -- We want instance declarations from all home-package
218 -- modules below this one, including boot modules, except
219 -- ourselves. The 'except ourselves' is so that we don't
220 -- get the instances from this module's hs-boot file
221 ; want_instances :: ModuleName -> Bool
222 ; want_instances mod = mod `elemUFM` dep_mods
223 && mod /= moduleName this_mod
224 ; (home_insts, home_fam_insts) = hptInstances hsc_env
228 -- Record boot-file info in the EPS, so that it's
229 -- visible to loadHiBootInterface in tcRnSrcDecls,
230 -- and any other incrementally-performed imports
231 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
233 -- Update the gbl env
234 ; updGblEnv ( \ gbl ->
236 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
237 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
238 tcg_rn_imports = fmap (const rn_imports) (tcg_rn_imports gbl),
239 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
240 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
245 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
246 -- Fail if there are any errors so far
247 -- The error printing (if needed) takes advantage
248 -- of the tcg_env we have now set
249 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
252 -- Load any orphan-module and family instance-module
253 -- interfaces, so that their rules and instance decls will be
255 ; loadOrphanModules (imp_orphs imports) False
256 ; loadOrphanModules (imp_finsts imports) True
258 -- Check type-familily consistency
259 ; traceRn (text "rn1: checking family instance consistency")
260 ; let { dir_imp_mods = moduleEnvKeys
263 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
269 %************************************************************************
271 Type-checking external-core modules
273 %************************************************************************
276 tcRnExtCore :: HscEnv
278 -> IO (Messages, Maybe ModGuts)
279 -- Nothing => some error occurred
281 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
282 -- The decls are IfaceDecls; all names are original names
283 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
285 initTc hsc_env ExtCoreFile False this_mod $ do {
287 let { ldecls = map noLoc decls } ;
289 -- bring the type and class decls into scope
290 -- ToDo: check that this doesn't need to extract the val binds.
291 -- It seems that only the type and class decls need to be in scope below because
292 -- (a) tcTyAndClassDecls doesn't need the val binds, and
293 -- (b) tcExtCoreBindings doesn't need anything
294 -- (in fact, it might not even need to be in the scope of
295 -- this tcg_env at all)
296 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
297 tc_envs <- extendGlobalRdrEnvRn avails emptyFsEnv {- no fixity decls -} ;
299 setEnvs tc_envs $ do {
301 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
303 -- Dump trace of renaming part
304 rnDump (ppr rn_decls) ;
306 -- Typecheck them all together so that
307 -- any mutually recursive types are done right
308 tcg_env <- tcTyAndClassDecls emptyModDetails rn_decls ;
309 -- Make the new type env available to stuff slurped from interface files
311 setGblEnv tcg_env $ do {
313 -- Now the core bindings
314 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
318 bndrs = bindersOfBinds core_binds ;
319 my_exports = map (Avail . idName) bndrs ;
320 -- ToDo: export the data types also?
322 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
324 mod_guts = ModGuts { mg_module = this_mod,
326 mg_used_names = emptyNameSet, -- ToDo: compute usage
327 mg_dir_imps = emptyModuleEnv, -- ??
328 mg_deps = noDependencies, -- ??
329 mg_exports = my_exports,
330 mg_types = final_type_env,
331 mg_insts = tcg_insts tcg_env,
332 mg_fam_insts = tcg_fam_insts tcg_env,
333 mg_inst_env = tcg_inst_env tcg_env,
334 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
336 mg_binds = core_binds,
339 mg_rdr_env = emptyGlobalRdrEnv,
340 mg_fix_env = emptyFixityEnv,
341 mg_warns = NoWarnings,
342 mg_foreign = NoStubs,
343 mg_hpc_info = emptyHpcInfo False,
344 mg_modBreaks = emptyModBreaks,
345 mg_vect_info = noVectInfo
348 tcCoreDump mod_guts ;
353 mkFakeGroup decls -- Rather clumsy; lots of unused fields
354 = emptyRdrGroup { hs_tyclds = decls }
358 %************************************************************************
360 Type-checking the top level of a module
362 %************************************************************************
365 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
366 -- Returns the variables free in the decls
367 -- Reason: solely to report unused imports and bindings
368 tcRnSrcDecls boot_iface decls
369 = do { -- Do all the declarations
370 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
372 -- Finish simplifying class constraints
374 -- tcSimplifyTop deals with constant or ambiguous InstIds.
375 -- How could there be ambiguous ones? They can only arise if a
376 -- top-level decl falls under the monomorphism restriction
377 -- and no subsequent decl instantiates its type.
379 -- We do this after checkMain, so that we use the type info
380 -- thaat checkMain adds
382 -- We do it with both global and local env in scope:
383 -- * the global env exposes the instances to tcSimplifyTop
384 -- * the local env exposes the local Ids to tcSimplifyTop,
385 -- so that we get better error messages (monomorphism restriction)
386 traceTc (text "Tc8") ;
387 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
389 -- Backsubstitution. This must be done last.
390 -- Even tcSimplifyTop may do some unification.
391 traceTc (text "Tc9") ;
392 let { (tcg_env, _) = tc_envs
393 ; TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
394 tcg_rules = rules, tcg_fords = fords } = tcg_env
395 ; all_binds = binds `unionBags` inst_binds } ;
397 failIfErrsM ; -- Don't zonk if there have been errors
398 -- It's a waste of time; and we may get debug warnings
399 -- about strangely-typed TyCons!
401 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
404 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
405 ; tcg_env' = tcg_env { tcg_binds = binds',
407 tcg_fords = fords' } } ;
409 setGlobalTypeEnv tcg_env' final_type_env
412 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
413 -- Loops around dealing with each top level inter-splice group
414 -- in turn, until it's dealt with the entire module
415 tc_rn_src_decls boot_details ds
416 = do { let { (first_group, group_tail) = findSplice ds } ;
417 -- If ds is [] we get ([], Nothing)
419 -- Deal with decls up to, but not including, the first splice
420 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
421 -- rnTopSrcDecls fails if there are any errors
423 (tcg_env, tcl_env) <- setGblEnv tcg_env $
424 tcTopSrcDecls boot_details rn_decls ;
426 -- If there is no splice, we're nearly done
427 setEnvs (tcg_env, tcl_env) $
429 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
430 return (tcg_env, tcl_env)
433 -- If there's a splice, we must carry on
434 Just (SpliceDecl splice_expr, rest_ds) -> do {
436 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
439 -- Rename the splice expression, and get its supporting decls
440 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
441 -- checkNoErrs: don't typecheck if renaming failed
442 rnDump (ppr rn_splice_expr) ;
444 -- Execute the splice
445 spliced_decls <- tcSpliceDecls rn_splice_expr ;
447 -- Glue them on the front of the remaining decls and loop
448 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
449 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
454 %************************************************************************
456 Compiling hs-boot source files, and
457 comparing the hi-boot interface with the real thing
459 %************************************************************************
462 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
463 tcRnHsBootDecls decls
464 = do { let { (first_group, group_tail) = findSplice decls }
467 Just stuff -> spliceInHsBootErr stuff
470 -- Rename the declarations
471 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
472 ; setGblEnv tcg_env $ do {
474 -- Todo: check no foreign decls, no rules, no default decls
476 -- Typecheck type/class decls
477 ; traceTc (text "Tc2")
478 ; let tycl_decls = hs_tyclds rn_group
479 ; tcg_env <- tcTyAndClassDecls emptyModDetails tycl_decls
480 ; setGblEnv tcg_env $ do {
482 -- Typecheck instance decls
483 ; traceTc (text "Tc3")
484 ; (tcg_env, inst_infos, _deriv_binds)
485 <- tcInstDecls1 tycl_decls (hs_instds rn_group) (hs_derivds rn_group)
486 ; setGblEnv tcg_env $ do {
488 -- Typecheck value declarations
489 ; traceTc (text "Tc5")
490 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
493 -- No simplification or zonking to do
494 ; traceTc (text "Tc7a")
495 ; gbl_env <- getGblEnv
497 -- Make the final type-env
498 -- Include the dfun_ids so that their type sigs
499 -- are written into the interface file
500 ; let { type_env0 = tcg_type_env gbl_env
501 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
502 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
503 ; dfun_ids = map iDFunId inst_infos }
504 ; setGlobalTypeEnv gbl_env type_env2
507 spliceInHsBootErr (SpliceDecl (L loc _), _)
508 = addErrAt loc (ptext (sLit "Splices are not allowed in hs-boot files"))
511 Once we've typechecked the body of the module, we want to compare what
512 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
515 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
516 -- Compare the hi-boot file for this module (if there is one)
517 -- with the type environment we've just come up with
518 -- In the common case where there is no hi-boot file, the list
519 -- of boot_names is empty.
521 -- The bindings we return give bindings for the dfuns defined in the
522 -- hs-boot file, such as $fbEqT = $fEqT
525 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
526 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
527 tcg_type_env = local_type_env, tcg_exports = local_exports })
528 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
529 md_types = boot_type_env, md_exports = boot_exports })
530 | isHsBoot hs_src -- Current module is already a hs-boot file!
534 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
537 -- Check the exports of the boot module, one by one
538 ; mapM_ check_export boot_exports
540 -- Check for no family instances
541 ; unless (null boot_fam_insts) $
542 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
543 "instances in boot files yet...")
544 -- FIXME: Why? The actual comparison is not hard, but what would
545 -- be the equivalent to the dfun bindings returned for class
546 -- instances? We can't easily equate tycons...
548 -- Check instance declarations
549 ; mb_dfun_prs <- mapM check_inst boot_insts
550 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
551 final_type_env = extendTypeEnvWithIds local_type_env boot_dfuns
552 dfun_prs = catMaybes mb_dfun_prs
553 boot_dfuns = map fst dfun_prs
554 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
555 | (boot_dfun, dfun) <- dfun_prs ]
558 ; setGlobalTypeEnv tcg_env' final_type_env }
560 check_export boot_avail -- boot_avail is exported by the boot iface
561 | name `elem` dfun_names = return ()
562 | isWiredInName name = return () -- No checking for wired-in names. In particular,
563 -- 'error' is handled by a rather gross hack
564 -- (see comments in GHC.Err.hs-boot)
566 -- Check that the actual module exports the same thing
567 | not (null missing_names)
568 = addErrAt (nameSrcSpan (head missing_names))
569 (missingBootThing (head missing_names) "exported by")
571 -- If the boot module does not *define* the thing, we are done
572 -- (it simply re-exports it, and names match, so nothing further to do)
573 | isNothing mb_boot_thing = return ()
575 -- Check that the actual module also defines the thing, and
576 -- then compare the definitions
577 | Just real_thing <- lookupTypeEnv local_type_env name,
578 Just boot_thing <- mb_boot_thing
579 = when (not (checkBootDecl boot_thing real_thing))
580 $ addErrAt (nameSrcSpan (getName boot_thing))
581 (let boot_decl = tyThingToIfaceDecl
582 (fromJust mb_boot_thing)
583 real_decl = tyThingToIfaceDecl real_thing
584 in bootMisMatch real_thing boot_decl real_decl)
587 = addErrTc (missingBootThing name "defined in")
589 name = availName boot_avail
590 mb_boot_thing = lookupTypeEnv boot_type_env name
591 missing_names = case lookupNameEnv local_export_env name of
593 Just avail -> availNames boot_avail `minusList` availNames avail
595 dfun_names = map getName boot_insts
597 local_export_env :: NameEnv AvailInfo
598 local_export_env = availsToNameEnv local_exports
600 check_inst :: Instance -> TcM (Maybe (Id, Id))
601 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
603 = case [dfun | inst <- local_insts,
604 let dfun = instanceDFunId inst,
605 idType dfun `tcEqType` boot_inst_ty ] of
606 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
607 (dfun:_) -> return (Just (local_boot_dfun, dfun))
609 boot_dfun = instanceDFunId boot_inst
610 boot_inst_ty = idType boot_dfun
611 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
614 -- This has to compare the TyThing from the .hi-boot file to the TyThing
615 -- in the current source file. We must be careful to allow alpha-renaming
616 -- where appropriate, and also the boot declaration is allowed to omit
617 -- constructors and class methods.
619 -- See rnfail055 for a good test of this stuff.
621 checkBootDecl :: TyThing -> TyThing -> Bool
623 checkBootDecl (AnId id1) (AnId id2)
625 (idType id1 `tcEqType` idType id2)
627 checkBootDecl (ATyCon tc1) (ATyCon tc2)
628 | isSynTyCon tc1 && isSynTyCon tc2
630 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
631 env = rnBndrs2 env0 tvs1 tvs2
633 eqSynRhs (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
634 = tcEqTypeX env k1 k2
635 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
636 = tcEqTypeX env t1 t2
638 equalLength tvs1 tvs2 &&
639 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
641 | isAlgTyCon tc1 && isAlgTyCon tc2
643 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2)
644 && eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
646 | isForeignTyCon tc1 && isForeignTyCon tc2
647 = tyConExtName tc1 == tyConExtName tc2
649 env0 = mkRnEnv2 emptyInScopeSet
651 eqAlgRhs AbstractTyCon _ = True
652 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
653 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
654 eqListBy eqCon (data_cons tc1) (data_cons tc2)
655 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
656 eqCon (data_con tc1) (data_con tc2)
660 = dataConName c1 == dataConName c2
661 && dataConIsInfix c1 == dataConIsInfix c2
662 && dataConStrictMarks c1 == dataConStrictMarks c2
663 && dataConFieldLabels c1 == dataConFieldLabels c2
664 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
665 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
666 env = rnBndrs2 env0 tvs1 tvs2
668 equalLength tvs1 tvs2 &&
669 eqListBy (tcEqPredX env)
670 (dataConEqTheta c1 ++ dataConDictTheta c1)
671 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
672 eqListBy (tcEqTypeX env)
673 (dataConOrigArgTys c1)
674 (dataConOrigArgTys c2)
676 checkBootDecl (AClass c1) (AClass c2)
678 (clas_tyvars1, clas_fds1, sc_theta1, _, _, op_stuff1)
679 = classExtraBigSig c1
680 (clas_tyvars2, clas_fds2, sc_theta2, _, _, op_stuff2)
681 = classExtraBigSig c2
683 env0 = mkRnEnv2 emptyInScopeSet
684 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
686 eqSig (id1, def_meth1) (id2, def_meth2)
687 = idName id1 == idName id2 &&
688 tcEqTypeX env op_ty1 op_ty2
690 (_, rho_ty1) = splitForAllTys (idType id1)
691 op_ty1 = funResultTy rho_ty1
692 (_, rho_ty2) = splitForAllTys (idType id2)
693 op_ty2 = funResultTy rho_ty2
695 eqFD (as1,bs1) (as2,bs2) =
696 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
697 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
699 equalLength clas_tyvars1 clas_tyvars2 &&
700 eqListBy eqFD clas_fds1 clas_fds2 &&
701 (null sc_theta1 && null op_stuff1
703 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
704 eqListBy eqSig op_stuff1 op_stuff2)
706 checkBootDecl (ADataCon dc1) (ADataCon dc2)
707 = pprPanic "checkBootDecl" (ppr dc1)
709 checkBootDecl _ _ = False -- probably shouldn't happen
712 missingBootThing thing what
713 = ppr thing <+> ptext (sLit "is exported by the hs-boot file, but not")
714 <+> text what <+> ptext (sLit "the module")
716 bootMisMatch thing boot_decl real_decl
717 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
718 ptext (sLit "Main module:") <+> ppr real_decl,
719 ptext (sLit "Boot file: ") <+> ppr boot_decl]
723 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
727 %************************************************************************
729 Type-checking the top level of a module
731 %************************************************************************
733 tcRnGroup takes a bunch of top-level source-code declarations, and
735 * gets supporting declarations from interface files
738 * and augments the TcGblEnv with the results
740 In Template Haskell it may be called repeatedly for each group of
741 declarations. It expects there to be an incoming TcGblEnv in the
742 monad; it augments it and returns the new TcGblEnv.
745 ------------------------------------------------
746 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
747 -- Fails if there are any errors
749 = do { -- Rename the source decls
750 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls group ;
752 -- save the renamed syntax, if we want it
754 | Just grp <- tcg_rn_decls tcg_env
755 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
759 -- Dump trace of renaming part
760 rnDump (ppr rn_decls) ;
762 return (tcg_env', rn_decls)
765 ------------------------------------------------
766 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
767 tcTopSrcDecls boot_details
768 (HsGroup { hs_tyclds = tycl_decls,
769 hs_instds = inst_decls,
770 hs_derivds = deriv_decls,
771 hs_fords = foreign_decls,
772 hs_defds = default_decls,
773 hs_ruleds = rule_decls,
774 hs_valds = val_binds })
775 = do { -- Type-check the type and class decls, and all imported decls
776 -- The latter come in via tycl_decls
777 traceTc (text "Tc2") ;
779 tcg_env <- tcTyAndClassDecls boot_details tycl_decls ;
780 -- If there are any errors, tcTyAndClassDecls fails here
782 setGblEnv tcg_env $ do {
783 -- Source-language instances, including derivings,
784 -- and import the supporting declarations
785 traceTc (text "Tc3") ;
786 (tcg_env, inst_infos, deriv_binds)
787 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
788 setGblEnv tcg_env $ do {
790 -- Foreign import declarations next. No zonking necessary
791 -- here; we can tuck them straight into the global environment.
792 traceTc (text "Tc4") ;
793 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
794 tcExtendGlobalValEnv fi_ids $ do {
796 -- Default declarations
797 traceTc (text "Tc4a") ;
798 default_tys <- tcDefaults default_decls ;
799 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
801 -- Value declarations next
802 -- We also typecheck any extra binds that came out
803 -- of the "deriving" process (deriv_binds)
804 traceTc (text "Tc5") ;
805 (tc_val_binds, tcl_env) <- tcTopBinds val_binds ;
806 setLclTypeEnv tcl_env $ do {
808 -- Now GHC-generated derived bindings and generics.
809 -- Do not generate warnings from compiler-generated code.
810 (tc_deriv_binds, tcl_env) <- discardWarnings $
811 tcTopBinds deriv_binds ;
813 -- Second pass over class and instance declarations,
814 traceTc (text "Tc6") ;
815 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $ tcInstDecls2 tycl_decls inst_infos ;
816 showLIE (text "after instDecls2") ;
819 -- They need to be zonked, so we return them
820 traceTc (text "Tc7") ;
821 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
824 rules <- tcRules rule_decls ;
827 traceTc (text "Tc7a") ;
828 tcg_env <- getGblEnv ;
829 let { all_binds = tc_val_binds `unionBags`
830 tc_deriv_binds `unionBags`
831 inst_binds `unionBags`
834 -- Extend the GblEnv with the (as yet un-zonked)
835 -- bindings, rules, foreign decls
836 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
837 tcg_rules = tcg_rules tcg_env ++ rules,
838 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
839 return (tcg_env', tcl_env)
844 %************************************************************************
848 %************************************************************************
851 checkMain :: TcM TcGblEnv
852 -- If we are in module Main, check that 'main' is defined.
854 = do { tcg_env <- getGblEnv ;
856 check_main dflags tcg_env
859 check_main dflags tcg_env
861 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
865 = do { mb_main <- lookupSrcOcc_maybe main_fn
866 -- Check that 'main' is in scope
867 -- It might be imported from another module!
869 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
874 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
875 ; let loc = srcLocSpan (getSrcLoc main_name)
876 ; ioTyCon <- tcLookupTyCon ioTyConName
877 ; (main_expr, res_ty)
878 <- addErrCtxt mainCtxt $
879 withBox liftedTypeKind $ \res_ty ->
880 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
882 -- See Note [Root-main Id]
883 -- Construct the binding
884 -- :Main.main :: IO res_ty = runMainIO res_ty main
885 ; run_main_id <- tcLookupId runMainIOName
886 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
887 (mkVarOccFS (fsLit "main"))
888 (getSrcSpan main_name)
889 ; root_main_id = Id.mkExportedLocalId root_main_name
890 (mkTyConApp ioTyCon [res_ty])
891 ; co = mkWpTyApps [res_ty]
892 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
893 ; main_bind = noLoc (VarBind root_main_id rhs) }
895 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
897 tcg_dus = tcg_dus tcg_env
898 `plusDU` usesOnly (unitFV main_name)
899 -- Record the use of 'main', so that we don't
900 -- complain about it being defined but not used
904 mod = tcg_mod tcg_env
905 main_mod = mainModIs dflags
906 main_fn = getMainFun dflags
908 complain_no_main | ghcLink dflags == LinkInMemory = return ()
909 | otherwise = failWithTc noMainMsg
910 -- In interactive mode, don't worry about the absence of 'main'
911 -- In other modes, fail altogether, so that we don't go on
912 -- and complain a second time when processing the export list.
914 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
915 noMainMsg = ptext (sLit "The") <+> pp_main_fn
916 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
917 pp_main_fn | main_fn == main_RDR_Unqual = ptext (sLit "function") <+> quotes (ppr main_fn)
918 | otherwise = ptext (sLit "main function") <+> quotes (ppr main_fn)
924 The function that the RTS invokes is always :Main.main, which we call
925 root_main_id. (Because GHC allows the user to have a module not
926 called Main as the main module, we can't rely on the main function
927 being called "Main.main". That's why root_main_id has a fixed module
930 This is unusual: it's a LocalId whose Name has a Module from another
931 module. Tiresomely, we must filter it out again in MkIface, les we
932 get two defns for 'main' in the interface file!
935 %*********************************************************
939 %*********************************************************
943 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
944 setInteractiveContext hsc_env icxt thing_inside
945 = let -- Initialise the tcg_inst_env with instances from all home modules.
946 -- This mimics the more selective call to hptInstances in tcRnModule.
947 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
949 updGblEnv (\env -> env {
950 tcg_rdr_env = ic_rn_gbl_env icxt,
951 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
952 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
956 tcExtendGhciEnv (ic_tmp_ids icxt) $
957 -- tcExtendGhciEnv does lots:
958 -- - it extends the local type env (tcl_env) with the given Ids,
959 -- - it extends the local rdr env (tcl_rdr) with the Names from
961 -- - it adds the free tyvars of the Ids to the tcl_tyvars
964 -- later ids in ic_tmp_ids must shadow earlier ones with the same
965 -- OccName, and tcExtendIdEnv implements this behaviour.
967 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
974 -> InteractiveContext
976 -> IO (Messages, Maybe ([Id], LHsExpr Id))
977 -- The returned [Id] is the list of new Ids bound by
978 -- this statement. It can be used to extend the
979 -- InteractiveContext via extendInteractiveContext.
981 -- The returned TypecheckedHsExpr is of type IO [ () ],
982 -- a list of the bound values, coerced to ().
984 tcRnStmt hsc_env ictxt rdr_stmt
985 = initTcPrintErrors hsc_env iNTERACTIVE $
986 setInteractiveContext hsc_env ictxt $ do {
988 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
989 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
990 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
992 rnDump (ppr rn_stmt) ;
994 -- The real work is done here
995 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
996 zonked_expr <- zonkTopLExpr tc_expr ;
997 zonked_ids <- zonkTopBndrs bound_ids ;
999 -- None of the Ids should be of unboxed type, because we
1000 -- cast them all to HValues in the end!
1001 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1003 traceTc (text "tcs 1") ;
1004 let { global_ids = map globaliseAndTidy zonked_ids } ;
1006 {- ---------------------------------------------
1007 At one stage I removed any shadowed bindings from the type_env;
1008 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1009 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1011 Prelude> let f n = n * 2 :: Int
1012 Prelude> fName <- runQ [| f |]
1013 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1015 Prelude> let f n = n * 3 :: Int
1016 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1017 In the last line we use 'fName', which resolves to the *first* 'f'
1018 in scope. If we delete it from the type env, GHCi crashes because
1019 it doesn't expect that.
1021 Hence this code is commented out
1023 -------------------------------------------------- -}
1025 dumpOptTcRn Opt_D_dump_tc
1026 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1027 text "Typechecked expr" <+> ppr zonked_expr]) ;
1029 return (global_ids, zonked_expr)
1032 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1033 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1035 globaliseAndTidy :: Id -> Id
1036 globaliseAndTidy id -- Note [Interactively-bound Ids in GHCi]
1037 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
1039 tidy_type = tidyTopType (idType id)
1042 Note [Interactively-bound Ids in GHCi]
1043 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1044 The Ids bound by previous Stmts in Template Haskell are currently
1046 b) with an Internal Name (not External)
1047 c) and a tidied type
1049 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1050 compile an expression using these ids later, the byte code
1051 generator will consider the occurrences to be free rather than
1054 (b) They retain their Internal names becuase we don't have a suitable
1055 Module to name them with. We could revisit this choice.
1057 (c) Their types are tidied. This is important, because :info may ask
1058 to look at them, and :info expects the things it looks up to have
1062 --------------------------------------------------------------------------
1063 Typechecking Stmts in GHCi
1065 Here is the grand plan, implemented in tcUserStmt
1067 What you type The IO [HValue] that hscStmt returns
1068 ------------- ------------------------------------
1069 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1072 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1075 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1076 [NB: result not printed] bindings: [it]
1078 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1079 result showable) bindings: [it]
1081 expr (of non-IO type,
1082 result not showable) ==> error
1086 ---------------------------
1087 type PlanResult = ([Id], LHsExpr Id)
1088 type Plan = TcM PlanResult
1090 runPlans :: [Plan] -> TcM PlanResult
1091 -- Try the plans in order. If one fails (by raising an exn), try the next.
1092 -- If one succeeds, take it.
1093 runPlans [] = panic "runPlans"
1095 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1097 --------------------
1098 mkPlan :: LStmt Name -> TcM PlanResult
1099 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1100 = do { uniq <- newUnique -- is treated very specially
1101 ; let fresh_it = itName uniq
1102 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1103 matches = [mkMatch [] expr emptyLocalBinds]
1104 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1105 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1106 (HsVar bindIOName) noSyntaxExpr
1107 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1108 (HsVar thenIOName) placeHolderType
1111 -- [it <- e; print it] but not if it::()
1113 -- [let it = e; print it]
1114 ; runPlans [ -- Plan A
1115 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1116 ; it_ty <- zonkTcType (idType it_id)
1117 ; when (isUnitTy it_ty) failM
1120 -- Plan B; a naked bind statment
1121 tcGhciStmts [bind_stmt],
1123 -- Plan C; check that the let-binding is typeable all by itself.
1124 -- If not, fail; if so, try to print it.
1125 -- The two-step process avoids getting two errors: one from
1126 -- the expression itself, and one from the 'print it' part
1127 -- This two-step story is very clunky, alas
1128 do { checkNoErrs (tcGhciStmts [let_stmt])
1129 --- checkNoErrs defeats the error recovery of let-bindings
1130 ; tcGhciStmts [let_stmt, print_it] }
1133 mkPlan stmt@(L loc (BindStmt {}))
1134 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1135 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1136 (HsVar thenIOName) placeHolderType
1138 ; print_bind_result <- doptM Opt_PrintBindResult
1139 ; let print_plan = do
1140 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1141 ; v_ty <- zonkTcType (idType v_id)
1142 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1146 -- [stmt; print v] but not if v::()
1148 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1149 [tcGhciStmts [stmt]])
1153 = tcGhciStmts [stmt]
1155 ---------------------------
1156 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1158 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1159 ret_id <- tcLookupId returnIOName ; -- return @ IO
1161 ret_ty = mkListTy unitTy ;
1162 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1163 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1165 names = map unLoc (collectLStmtsBinders stmts) ;
1167 -- mk_return builds the expression
1168 -- returnIO @ [()] [coerce () x, .., coerce () z]
1170 -- Despite the inconvenience of building the type applications etc,
1171 -- this *has* to be done in type-annotated post-typecheck form
1172 -- because we are going to return a list of *polymorphic* values
1173 -- coerced to type (). If we built a *source* stmt
1174 -- return [coerce x, ..., coerce z]
1175 -- then the type checker would instantiate x..z, and we wouldn't
1176 -- get their *polymorphic* values. (And we'd get ambiguity errs
1177 -- if they were overloaded, since they aren't applied to anything.)
1178 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1179 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1180 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1184 -- OK, we're ready to typecheck the stmts
1185 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1186 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1187 mapM tcLookupId names ;
1188 -- Look up the names right in the middle,
1189 -- where they will all be in scope
1191 -- Simplify the context
1192 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1193 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1194 -- checkNoErrs ensures that the plan fails if context redn fails
1196 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1197 return (ids, mkHsDictLet const_binds $
1198 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1203 tcRnExpr just finds the type of an expression
1207 -> InteractiveContext
1209 -> IO (Messages, Maybe Type)
1210 tcRnExpr hsc_env ictxt rdr_expr
1211 = initTcPrintErrors hsc_env iNTERACTIVE $
1212 setInteractiveContext hsc_env ictxt $ do {
1214 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1217 -- Now typecheck the expression;
1218 -- it might have a rank-2 type (e.g. :t runST)
1219 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1220 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1221 tcSimplifyInteractive lie_top ;
1223 let { all_expr_ty = mkForAllTys qtvs $
1224 mkFunTys (map (idType . instToId) dict_insts) $
1226 zonkTcType all_expr_ty
1229 smpl_doc = ptext (sLit "main expression")
1232 tcRnType just finds the kind of a type
1236 -> InteractiveContext
1238 -> IO (Messages, Maybe Kind)
1239 tcRnType hsc_env ictxt rdr_type
1240 = initTcPrintErrors hsc_env iNTERACTIVE $
1241 setInteractiveContext hsc_env ictxt $ do {
1243 rn_type <- rnLHsType doc rdr_type ;
1246 -- Now kind-check the type
1247 (ty', kind) <- kcHsType rn_type ;
1251 doc = ptext (sLit "In GHCi input")
1257 %************************************************************************
1259 More GHCi stuff, to do with browsing and getting info
1261 %************************************************************************
1265 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
1266 -- a package module with an interface on disk. If neither of these is
1267 -- true, then the result will be an error indicating the interface
1268 -- could not be found.
1269 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1270 getModuleExports hsc_env mod
1273 checkMods = ic_toplev_scope ic ++ ic_exports ic
1275 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1277 -- Get the export avail info and also load all orphan and family-instance
1278 -- modules. Finally, check that the family instances of all modules in the
1279 -- interactive context are consistent (these modules are in the second
1281 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1282 tcGetModuleExports mod directlyImpMods
1283 = do { let doc = ptext (sLit "context for compiling statements")
1284 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1286 -- Load any orphan-module and family instance-module
1287 -- interfaces, so their instances are visible.
1288 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1289 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1291 -- Check that the family instances of all directly loaded
1292 -- modules are consistent.
1293 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1295 ; ifaceExportNames (mi_exports iface)
1298 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name])
1299 tcRnLookupRdrName hsc_env rdr_name
1300 = initTcPrintErrors hsc_env iNTERACTIVE $
1301 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1302 lookup_rdr_name rdr_name
1304 lookup_rdr_name rdr_name = do {
1305 -- If the identifier is a constructor (begins with an
1306 -- upper-case letter), then we need to consider both
1307 -- constructor and type class identifiers.
1308 let { rdr_names = dataTcOccs rdr_name } ;
1310 -- results :: [Either Messages Name]
1311 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1313 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1314 -- The successful lookups will be (Just name)
1315 let { (warns_s, good_names) = unzip [ (msgs, name)
1316 | (msgs, Just name) <- results] ;
1317 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1319 -- Fail if nothing good happened, else add warnings
1320 if null good_names then
1321 -- No lookup succeeded, so
1322 -- pick the first error message and report it
1323 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1324 -- while the other is "X is not in scope",
1325 -- we definitely want the former; but we might pick the latter
1326 do { addMessages (head errs_s) ; failM }
1327 else -- Add deprecation warnings
1328 mapM_ addMessages warns_s ;
1333 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
1334 tcRnLookupName hsc_env name
1335 = initTcPrintErrors hsc_env iNTERACTIVE $
1336 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1337 tcRnLookupName' name
1339 -- To look up a name we have to look in the local environment (tcl_lcl)
1340 -- as well as the global environment, which is what tcLookup does.
1341 -- But we also want a TyThing, so we have to convert:
1343 tcRnLookupName' :: Name -> TcRn TyThing
1344 tcRnLookupName' name = do
1345 tcthing <- tcLookup name
1347 AGlobal thing -> return thing
1348 ATcId{tct_id=id} -> return (AnId id)
1349 _ -> panic "tcRnLookupName'"
1351 tcRnGetInfo :: HscEnv
1353 -> IO (Messages, Maybe (TyThing, Fixity, [Instance]))
1355 -- Used to implemnent :info in GHCi
1357 -- Look up a RdrName and return all the TyThings it might be
1358 -- A capitalised RdrName is given to us in the DataName namespace,
1359 -- but we want to treat it as *both* a data constructor
1360 -- *and* as a type or class constructor;
1361 -- hence the call to dataTcOccs, and we return up to two results
1362 tcRnGetInfo hsc_env name
1363 = initTcPrintErrors hsc_env iNTERACTIVE $
1364 let ictxt = hsc_IC hsc_env in
1365 setInteractiveContext hsc_env ictxt $ do
1367 -- Load the interface for all unqualified types and classes
1368 -- That way we will find all the instance declarations
1369 -- (Packages have not orphan modules, and we assume that
1370 -- in the home package all relevant modules are loaded.)
1371 loadUnqualIfaces ictxt
1373 thing <- tcRnLookupName' name
1374 fixity <- lookupFixityRn name
1375 ispecs <- lookupInsts thing
1376 return (thing, fixity, ispecs)
1378 lookupInsts :: TyThing -> TcM [Instance]
1379 lookupInsts (AClass cls)
1380 = do { inst_envs <- tcGetInstEnvs
1381 ; return (classInstances inst_envs cls) }
1383 lookupInsts (ATyCon tc)
1384 = do { eps <- getEps -- Load all instances for all classes that are
1385 -- in the type environment (which are all the ones
1386 -- we've seen in any interface file so far)
1387 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1389 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1390 , let dfun = instanceDFunId ispec
1393 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1394 tc_name = tyConName tc
1396 lookupInsts other = return []
1398 loadUnqualIfaces :: InteractiveContext -> TcM ()
1399 -- Load the home module for everything that is in scope unqualified
1400 -- This is so that we can accurately report the instances for
1402 loadUnqualIfaces ictxt
1404 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1406 unqual_mods = [ nameModule name
1407 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1408 let name = gre_name gre,
1409 not (isInternalName name),
1410 isTcOcc (nameOccName name), -- Types and classes only
1411 unQualOK gre ] -- In scope unqualified
1412 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1416 %************************************************************************
1420 %************************************************************************
1423 rnDump :: SDoc -> TcRn ()
1424 -- Dump, with a banner, if -ddump-rn
1425 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1427 tcDump :: TcGblEnv -> TcRn ()
1429 = do { dflags <- getDOpts ;
1431 -- Dump short output if -ddump-types or -ddump-tc
1432 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1433 (dumpTcRn short_dump) ;
1435 -- Dump bindings if -ddump-tc
1436 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1439 short_dump = pprTcGblEnv env
1440 full_dump = pprLHsBinds (tcg_binds env)
1441 -- NB: foreign x-d's have undefined's in their types;
1442 -- hence can't show the tc_fords
1445 = do { dflags <- getDOpts ;
1446 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1447 (dumpTcRn (pprModGuts mod_guts)) ;
1449 -- Dump bindings if -ddump-tc
1450 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1452 full_dump = pprCoreBindings (mg_binds mod_guts)
1454 -- It's unpleasant having both pprModGuts and pprModDetails here
1455 pprTcGblEnv :: TcGblEnv -> SDoc
1456 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1458 tcg_fam_insts = fam_insts,
1460 tcg_imports = imports })
1461 = vcat [ ppr_types insts type_env
1462 , ppr_tycons fam_insts type_env
1464 , ppr_fam_insts fam_insts
1465 , vcat (map ppr rules)
1466 , ppr_gen_tycons (typeEnvTyCons type_env)
1467 , ptext (sLit "Dependent modules:") <+>
1468 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1469 , ptext (sLit "Dependent packages:") <+>
1470 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1471 where -- The two uses of sortBy are just to reduce unnecessary
1472 -- wobbling in testsuite output
1473 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1474 = (mod_name1 `stableModuleNameCmp` mod_name2)
1476 (is_boot1 `compare` is_boot2)
1478 pprModGuts :: ModGuts -> SDoc
1479 pprModGuts (ModGuts { mg_types = type_env,
1481 = vcat [ ppr_types [] type_env,
1484 ppr_types :: [Instance] -> TypeEnv -> SDoc
1485 ppr_types insts type_env
1486 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1488 dfun_ids = map instanceDFunId insts
1489 ids = [id | id <- typeEnvIds type_env, want_sig id]
1490 want_sig id | opt_PprStyle_Debug = True
1491 | otherwise = isLocalId id &&
1492 isExternalName (idName id) &&
1493 not (id `elem` dfun_ids)
1494 -- isLocalId ignores data constructors, records selectors etc.
1495 -- The isExternalName ignores local dictionary and method bindings
1496 -- that the type checker has invented. Top-level user-defined things
1497 -- have External names.
1499 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1500 ppr_tycons fam_insts type_env
1501 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1503 fi_tycons = map famInstTyCon fam_insts
1504 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1505 want_tycon tycon | opt_PprStyle_Debug = True
1506 | otherwise = not (isImplicitTyCon tycon) &&
1507 isExternalName (tyConName tycon) &&
1508 not (tycon `elem` fi_tycons)
1510 ppr_insts :: [Instance] -> SDoc
1511 ppr_insts [] = empty
1512 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1514 ppr_fam_insts :: [FamInst] -> SDoc
1515 ppr_fam_insts [] = empty
1516 ppr_fam_insts fam_insts =
1517 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1519 ppr_sigs :: [Var] -> SDoc
1521 -- Print type signatures; sort by OccName
1522 = vcat (map ppr_sig (sortLe le_sig ids))
1524 le_sig id1 id2 = getOccName id1 <= getOccName id2
1525 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1527 ppr_tydecls :: [TyCon] -> SDoc
1529 -- Print type constructor info; sort by OccName
1530 = vcat (map ppr_tycon (sortLe le_sig tycons))
1532 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1534 | isCoercionTyCon tycon = ptext (sLit "coercion") <+> ppr tycon
1535 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1537 ppr_rules :: [CoreRule] -> SDoc
1538 ppr_rules [] = empty
1539 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1540 nest 4 (pprRules rs),
1543 ppr_gen_tycons [] = empty
1544 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1545 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]