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 False avails
298 emptyFsEnv {- no fixity decls -} ;
300 setEnvs tc_envs $ do {
302 rn_decls <- checkNoErrs $ rnTyClDecls ldecls ;
304 -- Dump trace of renaming part
305 rnDump (ppr rn_decls) ;
307 -- Typecheck them all together so that
308 -- any mutually recursive types are done right
309 tcg_env <- tcTyAndClassDecls emptyModDetails rn_decls ;
310 -- Make the new type env available to stuff slurped from interface files
312 setGblEnv tcg_env $ do {
314 -- Now the core bindings
315 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
319 bndrs = bindersOfBinds core_binds ;
320 my_exports = map (Avail . idName) bndrs ;
321 -- ToDo: export the data types also?
323 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
325 mod_guts = ModGuts { mg_module = this_mod,
327 mg_used_names = emptyNameSet, -- ToDo: compute usage
328 mg_dir_imps = emptyModuleEnv, -- ??
329 mg_deps = noDependencies, -- ??
330 mg_exports = my_exports,
331 mg_types = final_type_env,
332 mg_insts = tcg_insts tcg_env,
333 mg_fam_insts = tcg_fam_insts tcg_env,
334 mg_inst_env = tcg_inst_env tcg_env,
335 mg_fam_inst_env = tcg_fam_inst_env tcg_env,
337 mg_binds = core_binds,
340 mg_rdr_env = emptyGlobalRdrEnv,
341 mg_fix_env = emptyFixityEnv,
342 mg_warns = NoWarnings,
343 mg_foreign = NoStubs,
344 mg_hpc_info = emptyHpcInfo False,
345 mg_modBreaks = emptyModBreaks,
346 mg_vect_info = noVectInfo
349 tcCoreDump mod_guts ;
354 mkFakeGroup decls -- Rather clumsy; lots of unused fields
355 = emptyRdrGroup { hs_tyclds = decls }
359 %************************************************************************
361 Type-checking the top level of a module
363 %************************************************************************
366 tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv
367 -- Returns the variables free in the decls
368 -- Reason: solely to report unused imports and bindings
369 tcRnSrcDecls boot_iface decls
370 = do { -- Do all the declarations
371 (tc_envs, lie) <- getLIE $ tc_rn_src_decls boot_iface decls ;
373 -- Finish simplifying class constraints
375 -- tcSimplifyTop deals with constant or ambiguous InstIds.
376 -- How could there be ambiguous ones? They can only arise if a
377 -- top-level decl falls under the monomorphism restriction
378 -- and no subsequent decl instantiates its type.
380 -- We do this after checkMain, so that we use the type info
381 -- thaat checkMain adds
383 -- We do it with both global and local env in scope:
384 -- * the global env exposes the instances to tcSimplifyTop
385 -- * the local env exposes the local Ids to tcSimplifyTop,
386 -- so that we get better error messages (monomorphism restriction)
387 traceTc (text "Tc8") ;
388 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
390 -- Backsubstitution. This must be done last.
391 -- Even tcSimplifyTop may do some unification.
392 traceTc (text "Tc9") ;
393 let { (tcg_env, _) = tc_envs
394 ; TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
395 tcg_rules = rules, tcg_fords = fords } = tcg_env
396 ; all_binds = binds `unionBags` inst_binds } ;
398 failIfErrsM ; -- Don't zonk if there have been errors
399 -- It's a waste of time; and we may get debug warnings
400 -- about strangely-typed TyCons!
402 (bind_ids, binds', fords', rules') <- zonkTopDecls all_binds rules fords ;
405 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
406 ; tcg_env' = tcg_env { tcg_binds = binds',
408 tcg_fords = fords' } } ;
410 setGlobalTypeEnv tcg_env' final_type_env
413 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
414 -- Loops around dealing with each top level inter-splice group
415 -- in turn, until it's dealt with the entire module
416 tc_rn_src_decls boot_details ds
417 = do { let { (first_group, group_tail) = findSplice ds } ;
418 -- If ds is [] we get ([], Nothing)
420 -- Deal with decls up to, but not including, the first splice
421 (tcg_env, rn_decls) <- rnTopSrcDecls first_group ;
422 -- rnTopSrcDecls fails if there are any errors
424 (tcg_env, tcl_env) <- setGblEnv tcg_env $
425 tcTopSrcDecls boot_details rn_decls ;
427 -- If there is no splice, we're nearly done
428 setEnvs (tcg_env, tcl_env) $
430 Nothing -> do { tcg_env <- checkMain ; -- Check for `main'
431 return (tcg_env, tcl_env)
434 -- If there's a splice, we must carry on
435 Just (SpliceDecl splice_expr, rest_ds) -> do {
437 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
440 -- Rename the splice expression, and get its supporting decls
441 (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ;
442 -- checkNoErrs: don't typecheck if renaming failed
443 rnDump (ppr rn_splice_expr) ;
445 -- Execute the splice
446 spliced_decls <- tcSpliceDecls rn_splice_expr ;
448 -- Glue them on the front of the remaining decls and loop
449 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
450 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
455 %************************************************************************
457 Compiling hs-boot source files, and
458 comparing the hi-boot interface with the real thing
460 %************************************************************************
463 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
464 tcRnHsBootDecls decls
465 = do { let { (first_group, group_tail) = findSplice decls }
468 Just stuff -> spliceInHsBootErr stuff
471 -- Rename the declarations
472 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
473 ; setGblEnv tcg_env $ do {
475 -- Todo: check no foreign decls, no rules, no default decls
477 -- Typecheck type/class decls
478 ; traceTc (text "Tc2")
479 ; let tycl_decls = hs_tyclds rn_group
480 ; tcg_env <- tcTyAndClassDecls emptyModDetails tycl_decls
481 ; setGblEnv tcg_env $ do {
483 -- Typecheck instance decls
484 ; traceTc (text "Tc3")
485 ; (tcg_env, inst_infos, _deriv_binds)
486 <- tcInstDecls1 tycl_decls (hs_instds rn_group) (hs_derivds rn_group)
487 ; setGblEnv tcg_env $ do {
489 -- Typecheck value declarations
490 ; traceTc (text "Tc5")
491 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
494 -- No simplification or zonking to do
495 ; traceTc (text "Tc7a")
496 ; gbl_env <- getGblEnv
498 -- Make the final type-env
499 -- Include the dfun_ids so that their type sigs
500 -- are written into the interface file
501 ; let { type_env0 = tcg_type_env gbl_env
502 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
503 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
504 ; dfun_ids = map iDFunId inst_infos }
505 ; setGlobalTypeEnv gbl_env type_env2
508 spliceInHsBootErr (SpliceDecl (L loc _), _)
509 = addErrAt loc (ptext (sLit "Splices are not allowed in hs-boot files"))
512 Once we've typechecked the body of the module, we want to compare what
513 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
516 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv
517 -- Compare the hi-boot file for this module (if there is one)
518 -- with the type environment we've just come up with
519 -- In the common case where there is no hi-boot file, the list
520 -- of boot_names is empty.
522 -- The bindings we return give bindings for the dfuns defined in the
523 -- hs-boot file, such as $fbEqT = $fEqT
526 tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds,
527 tcg_insts = local_insts, tcg_fam_insts = local_fam_insts,
528 tcg_type_env = local_type_env, tcg_exports = local_exports })
529 (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts,
530 md_types = boot_type_env, md_exports = boot_exports })
531 | isHsBoot hs_src -- Current module is already a hs-boot file!
535 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts $$
538 -- Check the exports of the boot module, one by one
539 ; mapM_ check_export boot_exports
541 -- Check for no family instances
542 ; unless (null boot_fam_insts) $
543 panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++
544 "instances in boot files yet...")
545 -- FIXME: Why? The actual comparison is not hard, but what would
546 -- be the equivalent to the dfun bindings returned for class
547 -- instances? We can't easily equate tycons...
549 -- Check instance declarations
550 ; mb_dfun_prs <- mapM check_inst boot_insts
551 ; let tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds }
552 final_type_env = extendTypeEnvWithIds local_type_env boot_dfuns
553 dfun_prs = catMaybes mb_dfun_prs
554 boot_dfuns = map fst dfun_prs
555 dfun_binds = listToBag [ noLoc $ VarBind boot_dfun (nlHsVar dfun)
556 | (boot_dfun, dfun) <- dfun_prs ]
559 ; setGlobalTypeEnv tcg_env' final_type_env }
561 check_export boot_avail -- boot_avail is exported by the boot iface
562 | name `elem` dfun_names = return ()
563 | isWiredInName name = return () -- No checking for wired-in names. In particular,
564 -- 'error' is handled by a rather gross hack
565 -- (see comments in GHC.Err.hs-boot)
567 -- Check that the actual module exports the same thing
568 | not (null missing_names)
569 = addErrAt (nameSrcSpan (head missing_names))
570 (missingBootThing (head missing_names) "exported by")
572 -- If the boot module does not *define* the thing, we are done
573 -- (it simply re-exports it, and names match, so nothing further to do)
574 | isNothing mb_boot_thing = return ()
576 -- Check that the actual module also defines the thing, and
577 -- then compare the definitions
578 | Just real_thing <- lookupTypeEnv local_type_env name,
579 Just boot_thing <- mb_boot_thing
580 = when (not (checkBootDecl boot_thing real_thing))
581 $ addErrAt (nameSrcSpan (getName boot_thing))
582 (let boot_decl = tyThingToIfaceDecl
583 (fromJust mb_boot_thing)
584 real_decl = tyThingToIfaceDecl real_thing
585 in bootMisMatch real_thing boot_decl real_decl)
588 = addErrTc (missingBootThing name "defined in")
590 name = availName boot_avail
591 mb_boot_thing = lookupTypeEnv boot_type_env name
592 missing_names = case lookupNameEnv local_export_env name of
594 Just avail -> availNames boot_avail `minusList` availNames avail
596 dfun_names = map getName boot_insts
598 local_export_env :: NameEnv AvailInfo
599 local_export_env = availsToNameEnv local_exports
601 check_inst :: Instance -> TcM (Maybe (Id, Id))
602 -- Returns a pair of the boot dfun in terms of the equivalent real dfun
604 = case [dfun | inst <- local_insts,
605 let dfun = instanceDFunId inst,
606 idType dfun `tcEqType` boot_inst_ty ] of
607 [] -> do { addErrTc (instMisMatch boot_inst); return Nothing }
608 (dfun:_) -> return (Just (local_boot_dfun, dfun))
610 boot_dfun = instanceDFunId boot_inst
611 boot_inst_ty = idType boot_dfun
612 local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty
615 -- This has to compare the TyThing from the .hi-boot file to the TyThing
616 -- in the current source file. We must be careful to allow alpha-renaming
617 -- where appropriate, and also the boot declaration is allowed to omit
618 -- constructors and class methods.
620 -- See rnfail055 for a good test of this stuff.
622 checkBootDecl :: TyThing -> TyThing -> Bool
624 checkBootDecl (AnId id1) (AnId id2)
626 (idType id1 `tcEqType` idType id2)
628 checkBootDecl (ATyCon tc1) (ATyCon tc2)
629 | isSynTyCon tc1 && isSynTyCon tc2
631 let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2
632 env = rnBndrs2 env0 tvs1 tvs2
634 eqSynRhs (OpenSynTyCon k1 _) (OpenSynTyCon k2 _)
635 = tcEqTypeX env k1 k2
636 eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2)
637 = tcEqTypeX env t1 t2
639 equalLength tvs1 tvs2 &&
640 eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2)
642 | isAlgTyCon tc1 && isAlgTyCon tc2
644 eqListBy tcEqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2)
645 && eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2)
647 | isForeignTyCon tc1 && isForeignTyCon tc2
648 = tyConExtName tc1 == tyConExtName tc2
650 env0 = mkRnEnv2 emptyInScopeSet
652 eqAlgRhs AbstractTyCon _ = True
653 eqAlgRhs OpenTyCon{} OpenTyCon{} = True
654 eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} =
655 eqListBy eqCon (data_cons tc1) (data_cons tc2)
656 eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} =
657 eqCon (data_con tc1) (data_con tc2)
661 = dataConName c1 == dataConName c2
662 && dataConIsInfix c1 == dataConIsInfix c2
663 && dataConStrictMarks c1 == dataConStrictMarks c2
664 && dataConFieldLabels c1 == dataConFieldLabels c2
665 && let tvs1 = dataConUnivTyVars c1 ++ dataConExTyVars c1
666 tvs2 = dataConUnivTyVars c2 ++ dataConExTyVars c2
667 env = rnBndrs2 env0 tvs1 tvs2
669 equalLength tvs1 tvs2 &&
670 eqListBy (tcEqPredX env)
671 (dataConEqTheta c1 ++ dataConDictTheta c1)
672 (dataConEqTheta c2 ++ dataConDictTheta c2) &&
673 eqListBy (tcEqTypeX env)
674 (dataConOrigArgTys c1)
675 (dataConOrigArgTys c2)
677 checkBootDecl (AClass c1) (AClass c2)
679 (clas_tyvars1, clas_fds1, sc_theta1, _, _, op_stuff1)
680 = classExtraBigSig c1
681 (clas_tyvars2, clas_fds2, sc_theta2, _, _, op_stuff2)
682 = classExtraBigSig c2
684 env0 = mkRnEnv2 emptyInScopeSet
685 env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
687 eqSig (id1, def_meth1) (id2, def_meth2)
688 = idName id1 == idName id2 &&
689 tcEqTypeX env op_ty1 op_ty2
691 (_, rho_ty1) = splitForAllTys (idType id1)
692 op_ty1 = funResultTy rho_ty1
693 (_, rho_ty2) = splitForAllTys (idType id2)
694 op_ty2 = funResultTy rho_ty2
696 eqFD (as1,bs1) (as2,bs2) =
697 eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
698 eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
700 equalLength clas_tyvars1 clas_tyvars2 &&
701 eqListBy eqFD clas_fds1 clas_fds2 &&
702 (null sc_theta1 && null op_stuff1
704 eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
705 eqListBy eqSig op_stuff1 op_stuff2)
707 checkBootDecl (ADataCon dc1) (ADataCon dc2)
708 = pprPanic "checkBootDecl" (ppr dc1)
710 checkBootDecl _ _ = False -- probably shouldn't happen
713 missingBootThing thing what
714 = ppr thing <+> ptext (sLit "is exported by the hs-boot file, but not")
715 <+> text what <+> ptext (sLit "the module")
717 bootMisMatch thing boot_decl real_decl
718 = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"),
719 ptext (sLit "Main module:") <+> ppr real_decl,
720 ptext (sLit "Boot file: ") <+> ppr boot_decl]
724 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself"))
728 %************************************************************************
730 Type-checking the top level of a module
732 %************************************************************************
734 tcRnGroup takes a bunch of top-level source-code declarations, and
736 * gets supporting declarations from interface files
739 * and augments the TcGblEnv with the results
741 In Template Haskell it may be called repeatedly for each group of
742 declarations. It expects there to be an incoming TcGblEnv in the
743 monad; it augments it and returns the new TcGblEnv.
746 ------------------------------------------------
747 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
748 -- Fails if there are any errors
750 = do { -- Rename the source decls (with no shadowing; error on duplicates)
751 (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls False group ;
753 -- save the renamed syntax, if we want it
755 | Just grp <- tcg_rn_decls tcg_env
756 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
760 -- Dump trace of renaming part
761 rnDump (ppr rn_decls) ;
763 return (tcg_env', rn_decls)
766 ------------------------------------------------
767 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
768 tcTopSrcDecls boot_details
769 (HsGroup { hs_tyclds = tycl_decls,
770 hs_instds = inst_decls,
771 hs_derivds = deriv_decls,
772 hs_fords = foreign_decls,
773 hs_defds = default_decls,
774 hs_ruleds = rule_decls,
775 hs_valds = val_binds })
776 = do { -- Type-check the type and class decls, and all imported decls
777 -- The latter come in via tycl_decls
778 traceTc (text "Tc2") ;
780 tcg_env <- tcTyAndClassDecls boot_details tycl_decls ;
781 -- If there are any errors, tcTyAndClassDecls fails here
783 setGblEnv tcg_env $ do {
784 -- Source-language instances, including derivings,
785 -- and import the supporting declarations
786 traceTc (text "Tc3") ;
787 (tcg_env, inst_infos, deriv_binds)
788 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
789 setGblEnv tcg_env $ do {
791 -- Foreign import declarations next. No zonking necessary
792 -- here; we can tuck them straight into the global environment.
793 traceTc (text "Tc4") ;
794 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
795 tcExtendGlobalValEnv fi_ids $ do {
797 -- Default declarations
798 traceTc (text "Tc4a") ;
799 default_tys <- tcDefaults default_decls ;
800 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
802 -- Value declarations next
803 -- We also typecheck any extra binds that came out
804 -- of the "deriving" process (deriv_binds)
805 traceTc (text "Tc5") ;
806 (tc_val_binds, tcl_env) <- tcTopBinds val_binds ;
807 setLclTypeEnv tcl_env $ do {
809 -- Now GHC-generated derived bindings and generics.
810 -- Do not generate warnings from compiler-generated code.
811 (tc_deriv_binds, tcl_env) <- discardWarnings $
812 tcTopBinds deriv_binds ;
814 -- Second pass over class and instance declarations,
815 traceTc (text "Tc6") ;
816 (inst_binds, tcl_env) <- setLclTypeEnv tcl_env $ tcInstDecls2 tycl_decls inst_infos ;
817 showLIE (text "after instDecls2") ;
820 -- They need to be zonked, so we return them
821 traceTc (text "Tc7") ;
822 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
825 rules <- tcRules rule_decls ;
828 traceTc (text "Tc7a") ;
829 tcg_env <- getGblEnv ;
830 let { all_binds = tc_val_binds `unionBags`
831 tc_deriv_binds `unionBags`
832 inst_binds `unionBags`
835 -- Extend the GblEnv with the (as yet un-zonked)
836 -- bindings, rules, foreign decls
837 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
838 tcg_rules = tcg_rules tcg_env ++ rules,
839 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
840 return (tcg_env', tcl_env)
845 %************************************************************************
849 %************************************************************************
852 checkMain :: TcM TcGblEnv
853 -- If we are in module Main, check that 'main' is defined.
855 = do { tcg_env <- getGblEnv ;
857 check_main dflags tcg_env
860 check_main dflags tcg_env
862 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
866 = do { mb_main <- lookupSrcOcc_maybe main_fn
867 -- Check that 'main' is in scope
868 -- It might be imported from another module!
870 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
875 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
876 ; let loc = srcLocSpan (getSrcLoc main_name)
877 ; ioTyCon <- tcLookupTyCon ioTyConName
878 ; (main_expr, res_ty)
879 <- addErrCtxt mainCtxt $
880 withBox liftedTypeKind $ \res_ty ->
881 tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty])
883 -- See Note [Root-main Id]
884 -- Construct the binding
885 -- :Main.main :: IO res_ty = runMainIO res_ty main
886 ; run_main_id <- tcLookupId runMainIOName
887 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
888 (mkVarOccFS (fsLit "main"))
889 (getSrcSpan main_name)
890 ; root_main_id = Id.mkExportedLocalId root_main_name
891 (mkTyConApp ioTyCon [res_ty])
892 ; co = mkWpTyApps [res_ty]
893 ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr
894 ; main_bind = noLoc (VarBind root_main_id rhs) }
896 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
898 tcg_dus = tcg_dus tcg_env
899 `plusDU` usesOnly (unitFV main_name)
900 -- Record the use of 'main', so that we don't
901 -- complain about it being defined but not used
905 mod = tcg_mod tcg_env
906 main_mod = mainModIs dflags
907 main_fn = getMainFun dflags
909 complain_no_main | ghcLink dflags == LinkInMemory = return ()
910 | otherwise = failWithTc noMainMsg
911 -- In interactive mode, don't worry about the absence of 'main'
912 -- In other modes, fail altogether, so that we don't go on
913 -- and complain a second time when processing the export list.
915 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
916 noMainMsg = ptext (sLit "The") <+> pp_main_fn
917 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
918 pp_main_fn | main_fn == main_RDR_Unqual = ptext (sLit "function") <+> quotes (ppr main_fn)
919 | otherwise = ptext (sLit "main function") <+> quotes (ppr main_fn)
925 The function that the RTS invokes is always :Main.main, which we call
926 root_main_id. (Because GHC allows the user to have a module not
927 called Main as the main module, we can't rely on the main function
928 being called "Main.main". That's why root_main_id has a fixed module
931 This is unusual: it's a LocalId whose Name has a Module from another
932 module. Tiresomely, we must filter it out again in MkIface, les we
933 get two defns for 'main' in the interface file!
936 %*********************************************************
940 %*********************************************************
944 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
945 setInteractiveContext hsc_env icxt thing_inside
946 = let -- Initialise the tcg_inst_env with instances from all home modules.
947 -- This mimics the more selective call to hptInstances in tcRnModule.
948 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
950 updGblEnv (\env -> env {
951 tcg_rdr_env = ic_rn_gbl_env icxt,
952 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
953 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
957 tcExtendGhciEnv (ic_tmp_ids icxt) $
958 -- tcExtendGhciEnv does lots:
959 -- - it extends the local type env (tcl_env) with the given Ids,
960 -- - it extends the local rdr env (tcl_rdr) with the Names from
962 -- - it adds the free tyvars of the Ids to the tcl_tyvars
965 -- later ids in ic_tmp_ids must shadow earlier ones with the same
966 -- OccName, and tcExtendIdEnv implements this behaviour.
968 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
975 -> InteractiveContext
977 -> IO (Maybe ([Id], LHsExpr Id))
978 -- The returned [Id] is the list of new Ids bound by
979 -- this statement. It can be used to extend the
980 -- InteractiveContext via extendInteractiveContext.
982 -- The returned TypecheckedHsExpr is of type IO [ () ],
983 -- a list of the bound values, coerced to ().
985 tcRnStmt hsc_env ictxt rdr_stmt
986 = initTcPrintErrors hsc_env iNTERACTIVE $
987 setInteractiveContext hsc_env ictxt $ do {
989 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
990 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
991 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
993 rnDump (ppr rn_stmt) ;
995 -- The real work is done here
996 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
997 zonked_expr <- zonkTopLExpr tc_expr ;
998 zonked_ids <- zonkTopBndrs bound_ids ;
1000 -- None of the Ids should be of unboxed type, because we
1001 -- cast them all to HValues in the end!
1002 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1004 traceTc (text "tcs 1") ;
1005 let { global_ids = map globaliseAndTidy zonked_ids } ;
1007 {- ---------------------------------------------
1008 At one stage I removed any shadowed bindings from the type_env;
1009 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1010 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1012 Prelude> let f n = n * 2 :: Int
1013 Prelude> fName <- runQ [| f |]
1014 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1016 Prelude> let f n = n * 3 :: Int
1017 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1018 In the last line we use 'fName', which resolves to the *first* 'f'
1019 in scope. If we delete it from the type env, GHCi crashes because
1020 it doesn't expect that.
1022 Hence this code is commented out
1024 -------------------------------------------------- -}
1026 dumpOptTcRn Opt_D_dump_tc
1027 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1028 text "Typechecked expr" <+> ppr zonked_expr]) ;
1030 return (global_ids, zonked_expr)
1033 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1034 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1036 globaliseAndTidy :: Id -> Id
1037 globaliseAndTidy id -- Note [Interactively-bound Ids in GHCi]
1038 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
1040 tidy_type = tidyTopType (idType id)
1043 Note [Interactively-bound Ids in GHCi]
1044 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1045 The Ids bound by previous Stmts in Template Haskell are currently
1047 b) with an Internal Name (not External)
1048 c) and a tidied type
1050 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1051 compile an expression using these ids later, the byte code
1052 generator will consider the occurrences to be free rather than
1055 (b) They retain their Internal names becuase we don't have a suitable
1056 Module to name them with. We could revisit this choice.
1058 (c) Their types are tidied. This is important, because :info may ask
1059 to look at them, and :info expects the things it looks up to have
1063 --------------------------------------------------------------------------
1064 Typechecking Stmts in GHCi
1066 Here is the grand plan, implemented in tcUserStmt
1068 What you type The IO [HValue] that hscStmt returns
1069 ------------- ------------------------------------
1070 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1073 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1076 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1077 [NB: result not printed] bindings: [it]
1079 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1080 result showable) bindings: [it]
1082 expr (of non-IO type,
1083 result not showable) ==> error
1087 ---------------------------
1088 type PlanResult = ([Id], LHsExpr Id)
1089 type Plan = TcM PlanResult
1091 runPlans :: [Plan] -> TcM PlanResult
1092 -- Try the plans in order. If one fails (by raising an exn), try the next.
1093 -- If one succeeds, take it.
1094 runPlans [] = panic "runPlans"
1096 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1098 --------------------
1099 mkPlan :: LStmt Name -> TcM PlanResult
1100 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1101 = do { uniq <- newUnique -- is treated very specially
1102 ; let fresh_it = itName uniq
1103 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1104 matches = [mkMatch [] expr emptyLocalBinds]
1105 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1106 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1107 (HsVar bindIOName) noSyntaxExpr
1108 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1109 (HsVar thenIOName) placeHolderType
1112 -- [it <- e; print it] but not if it::()
1114 -- [let it = e; print it]
1115 ; runPlans [ -- Plan A
1116 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1117 ; it_ty <- zonkTcType (idType it_id)
1118 ; when (isUnitTy it_ty) failM
1121 -- Plan B; a naked bind statment
1122 tcGhciStmts [bind_stmt],
1124 -- Plan C; check that the let-binding is typeable all by itself.
1125 -- If not, fail; if so, try to print it.
1126 -- The two-step process avoids getting two errors: one from
1127 -- the expression itself, and one from the 'print it' part
1128 -- This two-step story is very clunky, alas
1129 do { checkNoErrs (tcGhciStmts [let_stmt])
1130 --- checkNoErrs defeats the error recovery of let-bindings
1131 ; tcGhciStmts [let_stmt, print_it] }
1134 mkPlan stmt@(L loc (BindStmt {}))
1135 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1136 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1137 (HsVar thenIOName) placeHolderType
1139 ; print_bind_result <- doptM Opt_PrintBindResult
1140 ; let print_plan = do
1141 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1142 ; v_ty <- zonkTcType (idType v_id)
1143 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1147 -- [stmt; print v] but not if v::()
1149 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1150 [tcGhciStmts [stmt]])
1154 = tcGhciStmts [stmt]
1156 ---------------------------
1157 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1159 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1160 ret_id <- tcLookupId returnIOName ; -- return @ IO
1162 ret_ty = mkListTy unitTy ;
1163 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1164 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1166 names = map unLoc (collectLStmtsBinders stmts) ;
1168 -- mk_return builds the expression
1169 -- returnIO @ [()] [coerce () x, .., coerce () z]
1171 -- Despite the inconvenience of building the type applications etc,
1172 -- this *has* to be done in type-annotated post-typecheck form
1173 -- because we are going to return a list of *polymorphic* values
1174 -- coerced to type (). If we built a *source* stmt
1175 -- return [coerce x, ..., coerce z]
1176 -- then the type checker would instantiate x..z, and we wouldn't
1177 -- get their *polymorphic* values. (And we'd get ambiguity errs
1178 -- if they were overloaded, since they aren't applied to anything.)
1179 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1180 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1181 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1185 -- OK, we're ready to typecheck the stmts
1186 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1187 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1188 mapM tcLookupId names ;
1189 -- Look up the names right in the middle,
1190 -- where they will all be in scope
1192 -- Simplify the context
1193 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1194 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1195 -- checkNoErrs ensures that the plan fails if context redn fails
1197 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1198 return (ids, mkHsDictLet const_binds $
1199 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1204 tcRnExpr just finds the type of an expression
1208 -> InteractiveContext
1211 tcRnExpr hsc_env ictxt rdr_expr
1212 = initTcPrintErrors hsc_env iNTERACTIVE $
1213 setInteractiveContext hsc_env ictxt $ do {
1215 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1218 -- Now typecheck the expression;
1219 -- it might have a rank-2 type (e.g. :t runST)
1220 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1221 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1222 tcSimplifyInteractive lie_top ;
1224 let { all_expr_ty = mkForAllTys qtvs $
1225 mkFunTys (map (idType . instToId) dict_insts) $
1227 zonkTcType all_expr_ty
1230 smpl_doc = ptext (sLit "main expression")
1233 tcRnType just finds the kind of a type
1237 -> InteractiveContext
1240 tcRnType hsc_env ictxt rdr_type
1241 = initTcPrintErrors hsc_env iNTERACTIVE $
1242 setInteractiveContext hsc_env ictxt $ do {
1244 rn_type <- rnLHsType doc rdr_type ;
1247 -- Now kind-check the type
1248 (ty', kind) <- kcHsType rn_type ;
1252 doc = ptext (sLit "In GHCi input")
1258 %************************************************************************
1260 More GHCi stuff, to do with browsing and getting info
1262 %************************************************************************
1266 -- ASSUMES that the module is either in the HomePackageTable or is
1267 -- a package module with an interface on disk. If neither of these is
1268 -- true, then the result will be an error indicating the interface
1269 -- could not be found.
1270 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1271 getModuleExports hsc_env mod
1274 checkMods = ic_toplev_scope ic ++ ic_exports ic
1276 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1278 -- Get the export avail info and also load all orphan and family-instance
1279 -- modules. Finally, check that the family instances of all modules in the
1280 -- interactive context are consistent (these modules are in the second
1282 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1283 tcGetModuleExports mod directlyImpMods
1284 = do { let doc = ptext (sLit "context for compiling statements")
1285 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1287 -- Load any orphan-module and family instance-module
1288 -- interfaces, so their instances are visible.
1289 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1290 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1292 -- Check that the family instances of all directly loaded
1293 -- modules are consistent.
1294 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1296 ; ifaceExportNames (mi_exports iface)
1299 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1300 tcRnLookupRdrName hsc_env rdr_name
1301 = initTcPrintErrors hsc_env iNTERACTIVE $
1302 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1303 lookup_rdr_name rdr_name
1305 lookup_rdr_name rdr_name = do {
1306 -- If the identifier is a constructor (begins with an
1307 -- upper-case letter), then we need to consider both
1308 -- constructor and type class identifiers.
1309 let { rdr_names = dataTcOccs rdr_name } ;
1311 -- results :: [Either Messages Name]
1312 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1314 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1315 -- The successful lookups will be (Just name)
1316 let { (warns_s, good_names) = unzip [ (msgs, name)
1317 | (msgs, Just name) <- results] ;
1318 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1320 -- Fail if nothing good happened, else add warnings
1321 if null good_names then
1322 -- No lookup succeeded, so
1323 -- pick the first error message and report it
1324 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1325 -- while the other is "X is not in scope",
1326 -- we definitely want the former; but we might pick the latter
1327 do { addMessages (head errs_s) ; failM }
1328 else -- Add deprecation warnings
1329 mapM_ addMessages warns_s ;
1334 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1335 tcRnLookupName hsc_env name
1336 = initTcPrintErrors hsc_env iNTERACTIVE $
1337 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1338 tcRnLookupName' name
1340 -- To look up a name we have to look in the local environment (tcl_lcl)
1341 -- as well as the global environment, which is what tcLookup does.
1342 -- But we also want a TyThing, so we have to convert:
1344 tcRnLookupName' :: Name -> TcRn TyThing
1345 tcRnLookupName' name = do
1346 tcthing <- tcLookup name
1348 AGlobal thing -> return thing
1349 ATcId{tct_id=id} -> return (AnId id)
1350 _ -> panic "tcRnLookupName'"
1352 tcRnGetInfo :: HscEnv
1354 -> IO (Maybe (TyThing, Fixity, [Instance]))
1356 -- Used to implemnent :info in GHCi
1358 -- Look up a RdrName and return all the TyThings it might be
1359 -- A capitalised RdrName is given to us in the DataName namespace,
1360 -- but we want to treat it as *both* a data constructor
1361 -- *and* as a type or class constructor;
1362 -- hence the call to dataTcOccs, and we return up to two results
1363 tcRnGetInfo hsc_env name
1364 = initTcPrintErrors hsc_env iNTERACTIVE $
1365 let ictxt = hsc_IC hsc_env in
1366 setInteractiveContext hsc_env ictxt $ do
1368 -- Load the interface for all unqualified types and classes
1369 -- That way we will find all the instance declarations
1370 -- (Packages have not orphan modules, and we assume that
1371 -- in the home package all relevant modules are loaded.)
1372 loadUnqualIfaces ictxt
1374 thing <- tcRnLookupName' name
1375 fixity <- lookupFixityRn name
1376 ispecs <- lookupInsts thing
1377 return (thing, fixity, ispecs)
1379 lookupInsts :: TyThing -> TcM [Instance]
1380 lookupInsts (AClass cls)
1381 = do { inst_envs <- tcGetInstEnvs
1382 ; return (classInstances inst_envs cls) }
1384 lookupInsts (ATyCon tc)
1385 = do { eps <- getEps -- Load all instances for all classes that are
1386 -- in the type environment (which are all the ones
1387 -- we've seen in any interface file so far)
1388 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1390 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1391 , let dfun = instanceDFunId ispec
1394 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1395 tc_name = tyConName tc
1397 lookupInsts other = return []
1399 loadUnqualIfaces :: InteractiveContext -> TcM ()
1400 -- Load the home module for everything that is in scope unqualified
1401 -- This is so that we can accurately report the instances for
1403 loadUnqualIfaces ictxt
1405 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1407 unqual_mods = [ nameModule name
1408 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1409 let name = gre_name gre,
1410 not (isInternalName name),
1411 isTcOcc (nameOccName name), -- Types and classes only
1412 unQualOK gre ] -- In scope unqualified
1413 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1417 %************************************************************************
1421 %************************************************************************
1424 rnDump :: SDoc -> TcRn ()
1425 -- Dump, with a banner, if -ddump-rn
1426 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1428 tcDump :: TcGblEnv -> TcRn ()
1430 = do { dflags <- getDOpts ;
1432 -- Dump short output if -ddump-types or -ddump-tc
1433 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1434 (dumpTcRn short_dump) ;
1436 -- Dump bindings if -ddump-tc
1437 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1440 short_dump = pprTcGblEnv env
1441 full_dump = pprLHsBinds (tcg_binds env)
1442 -- NB: foreign x-d's have undefined's in their types;
1443 -- hence can't show the tc_fords
1446 = do { dflags <- getDOpts ;
1447 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1448 (dumpTcRn (pprModGuts mod_guts)) ;
1450 -- Dump bindings if -ddump-tc
1451 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1453 full_dump = pprCoreBindings (mg_binds mod_guts)
1455 -- It's unpleasant having both pprModGuts and pprModDetails here
1456 pprTcGblEnv :: TcGblEnv -> SDoc
1457 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1459 tcg_fam_insts = fam_insts,
1461 tcg_imports = imports })
1462 = vcat [ ppr_types insts type_env
1463 , ppr_tycons fam_insts type_env
1465 , ppr_fam_insts fam_insts
1466 , vcat (map ppr rules)
1467 , ppr_gen_tycons (typeEnvTyCons type_env)
1468 , ptext (sLit "Dependent modules:") <+>
1469 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1470 , ptext (sLit "Dependent packages:") <+>
1471 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1472 where -- The two uses of sortBy are just to reduce unnecessary
1473 -- wobbling in testsuite output
1474 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1475 = (mod_name1 `stableModuleNameCmp` mod_name2)
1477 (is_boot1 `compare` is_boot2)
1479 pprModGuts :: ModGuts -> SDoc
1480 pprModGuts (ModGuts { mg_types = type_env,
1482 = vcat [ ppr_types [] type_env,
1485 ppr_types :: [Instance] -> TypeEnv -> SDoc
1486 ppr_types insts type_env
1487 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1489 dfun_ids = map instanceDFunId insts
1490 ids = [id | id <- typeEnvIds type_env, want_sig id]
1491 want_sig id | opt_PprStyle_Debug = True
1492 | otherwise = isLocalId id &&
1493 isExternalName (idName id) &&
1494 not (id `elem` dfun_ids)
1495 -- isLocalId ignores data constructors, records selectors etc.
1496 -- The isExternalName ignores local dictionary and method bindings
1497 -- that the type checker has invented. Top-level user-defined things
1498 -- have External names.
1500 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1501 ppr_tycons fam_insts type_env
1502 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1504 fi_tycons = map famInstTyCon fam_insts
1505 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1506 want_tycon tycon | opt_PprStyle_Debug = True
1507 | otherwise = not (isImplicitTyCon tycon) &&
1508 isExternalName (tyConName tycon) &&
1509 not (tycon `elem` fi_tycons)
1511 ppr_insts :: [Instance] -> SDoc
1512 ppr_insts [] = empty
1513 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1515 ppr_fam_insts :: [FamInst] -> SDoc
1516 ppr_fam_insts [] = empty
1517 ppr_fam_insts fam_insts =
1518 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1520 ppr_sigs :: [Var] -> SDoc
1522 -- Print type signatures; sort by OccName
1523 = vcat (map ppr_sig (sortLe le_sig ids))
1525 le_sig id1 id2 = getOccName id1 <= getOccName id2
1526 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1528 ppr_tydecls :: [TyCon] -> SDoc
1530 -- Print type constructor info; sort by OccName
1531 = vcat (map ppr_tycon (sortLe le_sig tycons))
1533 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1535 | isCoercionTyCon tycon = ptext (sLit "coercion") <+> ppr tycon
1536 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1538 ppr_rules :: [CoreRule] -> SDoc
1539 ppr_rules [] = empty
1540 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1541 nest 4 (pprRules rs),
1544 ppr_gen_tycons [] = empty
1545 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1546 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]