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 -- Make the new type env available to stuff slurped from interface files
185 -- Must do this after checkHiBootIface, because the latter might add new
186 -- bindings for boot_dfuns, which may be mentioned in imported unfoldings
187 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
189 -- Rename the Haddock documentation
190 tcg_env <- rnHaddock module_info maybe_doc tcg_env ;
192 -- Report unused names
193 reportUnusedNames export_ies tcg_env ;
195 -- Dump output and return
202 %************************************************************************
206 %************************************************************************
209 tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv
210 tcRnImports hsc_env this_mod import_decls
211 = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ;
213 ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
214 ; dep_mods = imp_dep_mods imports
216 -- We want instance declarations from all home-package
217 -- modules below this one, including boot modules, except
218 -- ourselves. The 'except ourselves' is so that we don't
219 -- get the instances from this module's hs-boot file
220 ; want_instances :: ModuleName -> Bool
221 ; want_instances mod = mod `elemUFM` dep_mods
222 && mod /= moduleName this_mod
223 ; (home_insts, home_fam_insts) = hptInstances hsc_env
227 -- Record boot-file info in the EPS, so that it's
228 -- visible to loadHiBootInterface in tcRnSrcDecls,
229 -- and any other incrementally-performed imports
230 ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
232 -- Update the gbl env
233 ; updGblEnv ( \ gbl ->
235 tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
236 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
237 tcg_rn_imports = fmap (const rn_imports) (tcg_rn_imports gbl),
238 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
239 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl)
244 ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports))
245 -- Fail if there are any errors so far
246 -- The error printing (if needed) takes advantage
247 -- of the tcg_env we have now set
248 -- ; traceIf (text "rdr_env: " <+> ppr rdr_env)
251 -- Load any orphan-module and family instance-module
252 -- interfaces, so that their rules and instance decls will be
254 ; loadOrphanModules (imp_orphs imports) False
255 ; loadOrphanModules (imp_finsts imports) True
257 -- Check type-familily consistency
258 ; traceRn (text "rn1: checking family instance consistency")
259 ; let { dir_imp_mods = moduleEnvKeys
262 ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ;
268 %************************************************************************
270 Type-checking external-core modules
272 %************************************************************************
275 tcRnExtCore :: HscEnv
277 -> IO (Messages, Maybe ModGuts)
278 -- Nothing => some error occurred
280 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
281 -- The decls are IfaceDecls; all names are original names
282 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
284 initTc hsc_env ExtCoreFile False this_mod $ do {
286 let { ldecls = map noLoc decls } ;
288 -- bring the type and class decls into scope
289 -- ToDo: check that this doesn't need to extract the val binds.
290 -- It seems that only the type and class decls need to be in scope below because
291 -- (a) tcTyAndClassDecls doesn't need the val binds, and
292 -- (b) tcExtCoreBindings doesn't need anything
293 -- (in fact, it might not even need to be in the scope of
294 -- this tcg_env at all)
295 avails <- getLocalNonValBinders (mkFakeGroup ldecls) ;
296 tc_envs <- extendGlobalRdrEnvRn False avails
297 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 ;
403 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
404 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
407 tcg_fords = fords' } } ;
409 return (tcg_env' { tcg_binds = tcg_binds tcg_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 ; return (gbl_env { tcg_type_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 instance declarations
541 ; mb_dfun_prs <- mapM check_inst boot_insts
542 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds,
543 tcg_type_env = extendTypeEnvWithIds local_type_env boot_dfuns }
544 dfun_prs = catMaybes mb_dfun_prs
545 boot_dfuns = map fst dfun_prs
546 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
547 | (boot_dfun, dfun) <- dfun_prs ]
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...
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 (with no shadowing; error on duplicates)
750 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls False 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 -- Make these type and class decls available to stuff slurped from interface files
783 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
786 setGblEnv tcg_env $ do {
787 -- Source-language instances, including derivings,
788 -- and import the supporting declarations
789 traceTc (text "Tc3") ;
790 (tcg_env, inst_infos, deriv_binds)
791 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
792 setGblEnv tcg_env $ do {
794 -- Foreign import declarations next. No zonking necessary
795 -- here; we can tuck them straight into the global environment.
796 traceTc (text "Tc4") ;
797 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
798 tcExtendGlobalValEnv fi_ids $ do {
800 -- Default declarations
801 traceTc (text "Tc4a") ;
802 default_tys <- tcDefaults default_decls ;
803 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
805 -- Value declarations next
806 -- We also typecheck any extra binds that came out
807 -- of the "deriving" process (deriv_binds)
808 traceTc (text "Tc5") ;
809 (tc_val_binds, tcl_env) <- tcTopBinds val_binds ;
810 setLclTypeEnv tcl_env $ do {
812 -- Now GHC-generated derived bindings and generics.
813 -- Do not generate warnings from compiler-generated code.
814 (tc_deriv_binds, tcl_env) <- discardWarnings $
815 tcTopBinds deriv_binds ;
817 -- Second pass over class and instance declarations,
818 traceTc (text "Tc6") ;
819 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $ tcInstDecls2 tycl_decls inst_infos ;
820 showLIE (text "after instDecls2") ;
823 -- They need to be zonked, so we return them
824 traceTc (text "Tc7") ;
825 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
828 rules <- tcRules rule_decls ;
831 traceTc (text "Tc7a") ;
832 tcg_env <- getGblEnv ;
833 let { all_binds = tc_val_binds `unionBags`
834 tc_deriv_binds `unionBags`
835 inst_binds `unionBags`
838 -- Extend the GblEnv with the (as yet un-zonked)
839 -- bindings, rules, foreign decls
840 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
841 tcg_rules = tcg_rules tcg_env ++ rules,
842 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
843 return (tcg_env', tcl_env)
848 %************************************************************************
852 %************************************************************************
855 checkMain :: TcM TcGblEnv
856 -- If we are in module Main, check that 'main' is defined.
858 = do { tcg_env <- getGblEnv ;
860 check_main dflags tcg_env
863 check_main dflags tcg_env
865 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
869 = do { mb_main <- lookupSrcOcc_maybe main_fn
870 -- Check that 'main' is in scope
871 -- It might be imported from another module!
873 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
878 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
879 ; let loc = srcLocSpan (getSrcLoc main_name)
880 ; ioTyCon <- tcLookupTyCon ioTyConName
881 ; (main_expr, res_ty)
882 <- addErrCtxt mainCtxt $
883 withBox liftedTypeKind $ \res_ty ->
884 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
886 -- See Note [Root-main Id]
887 -- Construct the binding
888 -- :Main.main :: IO res_ty = runMainIO res_ty main
889 ; run_main_id <- tcLookupId runMainIOName
890 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
891 (mkVarOccFS (fsLit "main"))
892 (getSrcSpan main_name)
893 ; root_main_id = Id.mkExportedLocalId root_main_name
894 (mkTyConApp ioTyCon [res_ty])
895 ; co = mkWpTyApps [res_ty]
896 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
897 ; main_bind = noLoc (VarBind root_main_id rhs) }
899 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
901 tcg_dus = tcg_dus tcg_env
902 `plusDU` usesOnly (unitFV main_name)
903 -- Record the use of 'main', so that we don't
904 -- complain about it being defined but not used
908 mod = tcg_mod tcg_env
909 main_mod = mainModIs dflags
910 main_fn = getMainFun dflags
912 complain_no_main | ghcLink dflags == LinkInMemory = return ()
913 | otherwise = failWithTc noMainMsg
914 -- In interactive mode, don't worry about the absence of 'main'
915 -- In other modes, fail altogether, so that we don't go on
916 -- and complain a second time when processing the export list.
918 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
919 noMainMsg = ptext (sLit "The") <+> pp_main_fn
920 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
921 pp_main_fn | main_fn == main_RDR_Unqual = ptext (sLit "function") <+> quotes (ppr main_fn)
922 | otherwise = ptext (sLit "main function") <+> quotes (ppr main_fn)
928 The function that the RTS invokes is always :Main.main, which we call
929 root_main_id. (Because GHC allows the user to have a module not
930 called Main as the main module, we can't rely on the main function
931 being called "Main.main". That's why root_main_id has a fixed module
934 This is unusual: it's a LocalId whose Name has a Module from another
935 module. Tiresomely, we must filter it out again in MkIface, les we
936 get two defns for 'main' in the interface file!
939 %*********************************************************
943 %*********************************************************
947 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
948 setInteractiveContext hsc_env icxt thing_inside
949 = let -- Initialise the tcg_inst_env with instances from all home modules.
950 -- This mimics the more selective call to hptInstances in tcRnModule.
951 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
953 updGblEnv (\env -> env {
954 tcg_rdr_env = ic_rn_gbl_env icxt,
955 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
956 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
960 tcExtendGhciEnv (ic_tmp_ids icxt) $
961 -- tcExtendGhciEnv does lots:
962 -- - it extends the local type env (tcl_env) with the given Ids,
963 -- - it extends the local rdr env (tcl_rdr) with the Names from
965 -- - it adds the free tyvars of the Ids to the tcl_tyvars
968 -- later ids in ic_tmp_ids must shadow earlier ones with the same
969 -- OccName, and tcExtendIdEnv implements this behaviour.
971 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
978 -> InteractiveContext
980 -> IO (Maybe ([Id], LHsExpr Id))
981 -- The returned [Id] is the list of new Ids bound by
982 -- this statement. It can be used to extend the
983 -- InteractiveContext via extendInteractiveContext.
985 -- The returned TypecheckedHsExpr is of type IO [ () ],
986 -- a list of the bound values, coerced to ().
988 tcRnStmt hsc_env ictxt rdr_stmt
989 = initTcPrintErrors hsc_env iNTERACTIVE $
990 setInteractiveContext hsc_env ictxt $ do {
992 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
993 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
994 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
996 rnDump (ppr rn_stmt) ;
998 -- The real work is done here
999 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1000 zonked_expr <- zonkTopLExpr tc_expr ;
1001 zonked_ids <- zonkTopBndrs bound_ids ;
1003 -- None of the Ids should be of unboxed type, because we
1004 -- cast them all to HValues in the end!
1005 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1007 traceTc (text "tcs 1") ;
1008 let { global_ids = map globaliseAndTidy zonked_ids } ;
1010 {- ---------------------------------------------
1011 At one stage I removed any shadowed bindings from the type_env;
1012 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1013 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1015 Prelude> let f n = n * 2 :: Int
1016 Prelude> fName <- runQ [| f |]
1017 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1019 Prelude> let f n = n * 3 :: Int
1020 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1021 In the last line we use 'fName', which resolves to the *first* 'f'
1022 in scope. If we delete it from the type env, GHCi crashes because
1023 it doesn't expect that.
1025 Hence this code is commented out
1027 -------------------------------------------------- -}
1029 dumpOptTcRn Opt_D_dump_tc
1030 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1031 text "Typechecked expr" <+> ppr zonked_expr]) ;
1033 return (global_ids, zonked_expr)
1036 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1037 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1039 globaliseAndTidy :: Id -> Id
1040 globaliseAndTidy id -- Note [Interactively-bound Ids in GHCi]
1041 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
1043 tidy_type = tidyTopType (idType id)
1046 Note [Interactively-bound Ids in GHCi]
1047 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1048 The Ids bound by previous Stmts in Template Haskell are currently
1050 b) with an Internal Name (not External)
1051 c) and a tidied type
1053 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1054 compile an expression using these ids later, the byte code
1055 generator will consider the occurrences to be free rather than
1058 (b) They retain their Internal names becuase we don't have a suitable
1059 Module to name them with. We could revisit this choice.
1061 (c) Their types are tidied. This is important, because :info may ask
1062 to look at them, and :info expects the things it looks up to have
1066 --------------------------------------------------------------------------
1067 Typechecking Stmts in GHCi
1069 Here is the grand plan, implemented in tcUserStmt
1071 What you type The IO [HValue] that hscStmt returns
1072 ------------- ------------------------------------
1073 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1076 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1079 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1080 [NB: result not printed] bindings: [it]
1082 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1083 result showable) bindings: [it]
1085 expr (of non-IO type,
1086 result not showable) ==> error
1090 ---------------------------
1091 type PlanResult = ([Id], LHsExpr Id)
1092 type Plan = TcM PlanResult
1094 runPlans :: [Plan] -> TcM PlanResult
1095 -- Try the plans in order. If one fails (by raising an exn), try the next.
1096 -- If one succeeds, take it.
1097 runPlans [] = panic "runPlans"
1099 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1101 --------------------
1102 mkPlan :: LStmt Name -> TcM PlanResult
1103 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1104 = do { uniq <- newUnique -- is treated very specially
1105 ; let fresh_it = itName uniq
1106 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1107 matches = [mkMatch [] expr emptyLocalBinds]
1108 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1109 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1110 (HsVar bindIOName) noSyntaxExpr
1111 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1112 (HsVar thenIOName) placeHolderType
1115 -- [it <- e; print it] but not if it::()
1117 -- [let it = e; print it]
1118 ; runPlans [ -- Plan A
1119 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1120 ; it_ty <- zonkTcType (idType it_id)
1121 ; when (isUnitTy it_ty) failM
1124 -- Plan B; a naked bind statment
1125 tcGhciStmts [bind_stmt],
1127 -- Plan C; check that the let-binding is typeable all by itself.
1128 -- If not, fail; if so, try to print it.
1129 -- The two-step process avoids getting two errors: one from
1130 -- the expression itself, and one from the 'print it' part
1131 -- This two-step story is very clunky, alas
1132 do { checkNoErrs (tcGhciStmts [let_stmt])
1133 --- checkNoErrs defeats the error recovery of let-bindings
1134 ; tcGhciStmts [let_stmt, print_it] }
1137 mkPlan stmt@(L loc (BindStmt {}))
1138 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1139 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1140 (HsVar thenIOName) placeHolderType
1142 ; print_bind_result <- doptM Opt_PrintBindResult
1143 ; let print_plan = do
1144 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1145 ; v_ty <- zonkTcType (idType v_id)
1146 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1150 -- [stmt; print v] but not if v::()
1152 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1153 [tcGhciStmts [stmt]])
1157 = tcGhciStmts [stmt]
1159 ---------------------------
1160 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1162 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1163 ret_id <- tcLookupId returnIOName ; -- return @ IO
1165 ret_ty = mkListTy unitTy ;
1166 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1167 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1169 names = map unLoc (collectLStmtsBinders stmts) ;
1171 -- mk_return builds the expression
1172 -- returnIO @ [()] [coerce () x, .., coerce () z]
1174 -- Despite the inconvenience of building the type applications etc,
1175 -- this *has* to be done in type-annotated post-typecheck form
1176 -- because we are going to return a list of *polymorphic* values
1177 -- coerced to type (). If we built a *source* stmt
1178 -- return [coerce x, ..., coerce z]
1179 -- then the type checker would instantiate x..z, and we wouldn't
1180 -- get their *polymorphic* values. (And we'd get ambiguity errs
1181 -- if they were overloaded, since they aren't applied to anything.)
1182 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1183 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1184 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1188 -- OK, we're ready to typecheck the stmts
1189 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1190 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1191 mapM tcLookupId names ;
1192 -- Look up the names right in the middle,
1193 -- where they will all be in scope
1195 -- Simplify the context
1196 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1197 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1198 -- checkNoErrs ensures that the plan fails if context redn fails
1200 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1201 return (ids, mkHsDictLet const_binds $
1202 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1207 tcRnExpr just finds the type of an expression
1211 -> InteractiveContext
1214 tcRnExpr hsc_env ictxt rdr_expr
1215 = initTcPrintErrors hsc_env iNTERACTIVE $
1216 setInteractiveContext hsc_env ictxt $ do {
1218 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1221 -- Now typecheck the expression;
1222 -- it might have a rank-2 type (e.g. :t runST)
1223 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1224 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1225 tcSimplifyInteractive lie_top ;
1227 let { all_expr_ty = mkForAllTys qtvs $
1228 mkFunTys (map (idType . instToId) dict_insts) $
1230 zonkTcType all_expr_ty
1233 smpl_doc = ptext (sLit "main expression")
1236 tcRnType just finds the kind of a type
1240 -> InteractiveContext
1243 tcRnType hsc_env ictxt rdr_type
1244 = initTcPrintErrors hsc_env iNTERACTIVE $
1245 setInteractiveContext hsc_env ictxt $ do {
1247 rn_type <- rnLHsType doc rdr_type ;
1250 -- Now kind-check the type
1251 (ty', kind) <- kcHsType rn_type ;
1255 doc = ptext (sLit "In GHCi input")
1261 %************************************************************************
1263 More GHCi stuff, to do with browsing and getting info
1265 %************************************************************************
1269 -- ASSUMES that the module is either in the HomePackageTable or is
1270 -- a package module with an interface on disk. If neither of these is
1271 -- true, then the result will be an error indicating the interface
1272 -- could not be found.
1273 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1274 getModuleExports hsc_env mod
1277 checkMods = ic_toplev_scope ic ++ ic_exports ic
1279 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1281 -- Get the export avail info and also load all orphan and family-instance
1282 -- modules. Finally, check that the family instances of all modules in the
1283 -- interactive context are consistent (these modules are in the second
1285 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1286 tcGetModuleExports mod directlyImpMods
1287 = do { let doc = ptext (sLit "context for compiling statements")
1288 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1290 -- Load any orphan-module and family instance-module
1291 -- interfaces, so their instances are visible.
1292 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1293 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1295 -- Check that the family instances of all directly loaded
1296 -- modules are consistent.
1297 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1299 ; ifaceExportNames (mi_exports iface)
1302 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1303 tcRnLookupRdrName hsc_env rdr_name
1304 = initTcPrintErrors hsc_env iNTERACTIVE $
1305 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1306 lookup_rdr_name rdr_name
1308 lookup_rdr_name rdr_name = do {
1309 -- If the identifier is a constructor (begins with an
1310 -- upper-case letter), then we need to consider both
1311 -- constructor and type class identifiers.
1312 let { rdr_names = dataTcOccs rdr_name } ;
1314 -- results :: [Either Messages Name]
1315 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1317 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1318 -- The successful lookups will be (Just name)
1319 let { (warns_s, good_names) = unzip [ (msgs, name)
1320 | (msgs, Just name) <- results] ;
1321 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1323 -- Fail if nothing good happened, else add warnings
1324 if null good_names then
1325 -- No lookup succeeded, so
1326 -- pick the first error message and report it
1327 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1328 -- while the other is "X is not in scope",
1329 -- we definitely want the former; but we might pick the latter
1330 do { addMessages (head errs_s) ; failM }
1331 else -- Add deprecation warnings
1332 mapM_ addMessages warns_s ;
1337 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1338 tcRnLookupName hsc_env name
1339 = initTcPrintErrors hsc_env iNTERACTIVE $
1340 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1341 tcRnLookupName' name
1343 -- To look up a name we have to look in the local environment (tcl_lcl)
1344 -- as well as the global environment, which is what tcLookup does.
1345 -- But we also want a TyThing, so we have to convert:
1347 tcRnLookupName' :: Name -> TcRn TyThing
1348 tcRnLookupName' name = do
1349 tcthing <- tcLookup name
1351 AGlobal thing -> return thing
1352 ATcId{tct_id=id} -> return (AnId id)
1353 _ -> panic "tcRnLookupName'"
1355 tcRnGetInfo :: HscEnv
1357 -> IO (Maybe (TyThing, Fixity, [Instance]))
1359 -- Used to implemnent :info in GHCi
1361 -- Look up a RdrName and return all the TyThings it might be
1362 -- A capitalised RdrName is given to us in the DataName namespace,
1363 -- but we want to treat it as *both* a data constructor
1364 -- *and* as a type or class constructor;
1365 -- hence the call to dataTcOccs, and we return up to two results
1366 tcRnGetInfo hsc_env name
1367 = initTcPrintErrors hsc_env iNTERACTIVE $
1368 let ictxt = hsc_IC hsc_env in
1369 setInteractiveContext hsc_env ictxt $ do
1371 -- Load the interface for all unqualified types and classes
1372 -- That way we will find all the instance declarations
1373 -- (Packages have not orphan modules, and we assume that
1374 -- in the home package all relevant modules are loaded.)
1375 loadUnqualIfaces ictxt
1377 thing <- tcRnLookupName' name
1378 fixity <- lookupFixityRn name
1379 ispecs <- lookupInsts thing
1380 return (thing, fixity, ispecs)
1382 lookupInsts :: TyThing -> TcM [Instance]
1383 lookupInsts (AClass cls)
1384 = do { inst_envs <- tcGetInstEnvs
1385 ; return (classInstances inst_envs cls) }
1387 lookupInsts (ATyCon tc)
1388 = do { eps <- getEps -- Load all instances for all classes that are
1389 -- in the type environment (which are all the ones
1390 -- we've seen in any interface file so far)
1391 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1393 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1394 , let dfun = instanceDFunId ispec
1397 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1398 tc_name = tyConName tc
1400 lookupInsts other = return []
1402 loadUnqualIfaces :: InteractiveContext -> TcM ()
1403 -- Load the home module for everything that is in scope unqualified
1404 -- This is so that we can accurately report the instances for
1406 loadUnqualIfaces ictxt
1408 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1410 unqual_mods = [ nameModule name
1411 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1412 let name = gre_name gre,
1413 not (isInternalName name),
1414 isTcOcc (nameOccName name), -- Types and classes only
1415 unQualOK gre ] -- In scope unqualified
1416 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1420 %************************************************************************
1424 %************************************************************************
1427 rnDump :: SDoc -> TcRn ()
1428 -- Dump, with a banner, if -ddump-rn
1429 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1431 tcDump :: TcGblEnv -> TcRn ()
1433 = do { dflags <- getDOpts ;
1435 -- Dump short output if -ddump-types or -ddump-tc
1436 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1437 (dumpTcRn short_dump) ;
1439 -- Dump bindings if -ddump-tc
1440 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1443 short_dump = pprTcGblEnv env
1444 full_dump = pprLHsBinds (tcg_binds env)
1445 -- NB: foreign x-d's have undefined's in their types;
1446 -- hence can't show the tc_fords
1449 = do { dflags <- getDOpts ;
1450 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1451 (dumpTcRn (pprModGuts mod_guts)) ;
1453 -- Dump bindings if -ddump-tc
1454 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1456 full_dump = pprCoreBindings (mg_binds mod_guts)
1458 -- It's unpleasant having both pprModGuts and pprModDetails here
1459 pprTcGblEnv :: TcGblEnv -> SDoc
1460 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1462 tcg_fam_insts = fam_insts,
1464 tcg_imports = imports })
1465 = vcat [ ppr_types insts type_env
1466 , ppr_tycons fam_insts type_env
1468 , ppr_fam_insts fam_insts
1469 , vcat (map ppr rules)
1470 , ppr_gen_tycons (typeEnvTyCons type_env)
1471 , ptext (sLit "Dependent modules:") <+>
1472 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1473 , ptext (sLit "Dependent packages:") <+>
1474 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1475 where -- The two uses of sortBy are just to reduce unnecessary
1476 -- wobbling in testsuite output
1477 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1478 = (mod_name1 `stableModuleNameCmp` mod_name2)
1480 (is_boot1 `compare` is_boot2)
1482 pprModGuts :: ModGuts -> SDoc
1483 pprModGuts (ModGuts { mg_types = type_env,
1485 = vcat [ ppr_types [] type_env,
1488 ppr_types :: [Instance] -> TypeEnv -> SDoc
1489 ppr_types insts type_env
1490 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1492 dfun_ids = map instanceDFunId insts
1493 ids = [id | id <- typeEnvIds type_env, want_sig id]
1494 want_sig id | opt_PprStyle_Debug = True
1495 | otherwise = isLocalId id &&
1496 isExternalName (idName id) &&
1497 not (id `elem` dfun_ids)
1498 -- isLocalId ignores data constructors, records selectors etc.
1499 -- The isExternalName ignores local dictionary and method bindings
1500 -- that the type checker has invented. Top-level user-defined things
1501 -- have External names.
1503 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1504 ppr_tycons fam_insts type_env
1505 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1507 fi_tycons = map famInstTyCon fam_insts
1508 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1509 want_tycon tycon | opt_PprStyle_Debug = True
1510 | otherwise = not (isImplicitTyCon tycon) &&
1511 isExternalName (tyConName tycon) &&
1512 not (tycon `elem` fi_tycons)
1514 ppr_insts :: [Instance] -> SDoc
1515 ppr_insts [] = empty
1516 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1518 ppr_fam_insts :: [FamInst] -> SDoc
1519 ppr_fam_insts [] = empty
1520 ppr_fam_insts fam_insts =
1521 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1523 ppr_sigs :: [Var] -> SDoc
1525 -- Print type signatures; sort by OccName
1526 = vcat (map ppr_sig (sortLe le_sig ids))
1528 le_sig id1 id2 = getOccName id1 <= getOccName id2
1529 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1531 ppr_tydecls :: [TyCon] -> SDoc
1533 -- Print type constructor info; sort by OccName
1534 = vcat (map ppr_tycon (sortLe le_sig tycons))
1536 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1538 | isCoercionTyCon tycon = ptext (sLit "coercion") <+> ppr tycon
1539 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1541 ppr_rules :: [CoreRule] -> SDoc
1542 ppr_rules [] = empty
1543 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1544 nest 4 (pprRules rs),
1547 ppr_gen_tycons [] = empty
1548 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1549 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]