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 ; -- finishDeprecations crashes sometimes
172 -- as a result of typechecker repairs (e.g. unboundNames)
173 tcg_env <- finishDeprecations (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_deprecs = NoDeprecs,
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_is_flag = mainFunIs dflags
912 main_fn = case main_is_flag of
913 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
914 Nothing -> main_RDR_Unqual
916 complain_no_main | ghcLink dflags == LinkInMemory = return ()
917 | otherwise = failWithTc noMainMsg
918 -- In interactive mode, don't worry about the absence of 'main'
919 -- In other modes, fail altogether, so that we don't go on
920 -- and complain a second time when processing the export list.
922 mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn
923 noMainMsg = ptext (sLit "The") <+> pp_main_fn
924 <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod)
925 pp_main_fn | isJust main_is_flag = ptext (sLit "main function") <+> quotes (ppr main_fn)
926 | otherwise = ptext (sLit "function") <+> quotes (ppr main_fn)
931 The function that the RTS invokes is always :Main.main, which we call
932 root_main_id. (Because GHC allows the user to have a module not
933 called Main as the main module, we can't rely on the main function
934 being called "Main.main". That's why root_main_id has a fixed module
937 This is unusual: it's a LocalId whose Name has a Module from another
938 module. Tiresomely, we must filter it out again in MkIface, les we
939 get two defns for 'main' in the interface file!
942 %*********************************************************
946 %*********************************************************
950 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
951 setInteractiveContext hsc_env icxt thing_inside
952 = let -- Initialise the tcg_inst_env with instances from all home modules.
953 -- This mimics the more selective call to hptInstances in tcRnModule.
954 (home_insts, home_fam_insts) = hptInstances hsc_env (\mod -> True)
956 updGblEnv (\env -> env {
957 tcg_rdr_env = ic_rn_gbl_env icxt,
958 tcg_inst_env = extendInstEnvList (tcg_inst_env env) home_insts,
959 tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env env)
963 tcExtendGhciEnv (ic_tmp_ids icxt) $
964 -- tcExtendGhciEnv does lots:
965 -- - it extends the local type env (tcl_env) with the given Ids,
966 -- - it extends the local rdr env (tcl_rdr) with the Names from
968 -- - it adds the free tyvars of the Ids to the tcl_tyvars
971 -- later ids in ic_tmp_ids must shadow earlier ones with the same
972 -- OccName, and tcExtendIdEnv implements this behaviour.
974 do { traceTc (text "setIC" <+> ppr (ic_tmp_ids icxt))
981 -> InteractiveContext
983 -> IO (Maybe ([Id], LHsExpr Id))
984 -- The returned [Id] is the list of new Ids bound by
985 -- this statement. It can be used to extend the
986 -- InteractiveContext via extendInteractiveContext.
988 -- The returned TypecheckedHsExpr is of type IO [ () ],
989 -- a list of the bound values, coerced to ().
991 tcRnStmt hsc_env ictxt rdr_stmt
992 = initTcPrintErrors hsc_env iNTERACTIVE $
993 setInteractiveContext hsc_env ictxt $ do {
995 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
996 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
997 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
999 rnDump (ppr rn_stmt) ;
1001 -- The real work is done here
1002 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
1003 zonked_expr <- zonkTopLExpr tc_expr ;
1004 zonked_ids <- zonkTopBndrs bound_ids ;
1006 -- None of the Ids should be of unboxed type, because we
1007 -- cast them all to HValues in the end!
1008 mapM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
1010 traceTc (text "tcs 1") ;
1011 let { global_ids = map globaliseAndTidy zonked_ids } ;
1013 {- ---------------------------------------------
1014 At one stage I removed any shadowed bindings from the type_env;
1015 they are inaccessible but might, I suppose, cause a space leak if we leave them there.
1016 However, with Template Haskell they aren't necessarily inaccessible. Consider this
1018 Prelude> let f n = n * 2 :: Int
1019 Prelude> fName <- runQ [| f |]
1020 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1022 Prelude> let f n = n * 3 :: Int
1023 Prelude> $(return $ AppE fName (LitE (IntegerL 7)))
1024 In the last line we use 'fName', which resolves to the *first* 'f'
1025 in scope. If we delete it from the type env, GHCi crashes because
1026 it doesn't expect that.
1028 Hence this code is commented out
1030 -------------------------------------------------- -}
1032 dumpOptTcRn Opt_D_dump_tc
1033 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
1034 text "Typechecked expr" <+> ppr zonked_expr]) ;
1036 return (global_ids, zonked_expr)
1039 bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"),
1040 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
1042 globaliseAndTidy :: Id -> Id
1043 globaliseAndTidy id -- Note [Interactively-bound Ids in GHCi]
1044 = Id.setIdType (globaliseId VanillaGlobal id) tidy_type
1046 tidy_type = tidyTopType (idType id)
1049 Note [Interactively-bound Ids in GHCi]
1050 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1051 The Ids bound by previous Stmts in Template Haskell are currently
1053 b) with an Internal Name (not External)
1054 c) and a tidied type
1056 (a) They must be GlobalIds (not LocalIds) otherwise when we come to
1057 compile an expression using these ids later, the byte code
1058 generator will consider the occurrences to be free rather than
1061 (b) They retain their Internal names becuase we don't have a suitable
1062 Module to name them with. We could revisit this choice.
1064 (c) Their types are tidied. This is important, because :info may ask
1065 to look at them, and :info expects the things it looks up to have
1069 --------------------------------------------------------------------------
1070 Typechecking Stmts in GHCi
1072 Here is the grand plan, implemented in tcUserStmt
1074 What you type The IO [HValue] that hscStmt returns
1075 ------------- ------------------------------------
1076 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
1079 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
1082 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
1083 [NB: result not printed] bindings: [it]
1085 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
1086 result showable) bindings: [it]
1088 expr (of non-IO type,
1089 result not showable) ==> error
1093 ---------------------------
1094 type PlanResult = ([Id], LHsExpr Id)
1095 type Plan = TcM PlanResult
1097 runPlans :: [Plan] -> TcM PlanResult
1098 -- Try the plans in order. If one fails (by raising an exn), try the next.
1099 -- If one succeeds, take it.
1100 runPlans [] = panic "runPlans"
1102 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
1104 --------------------
1105 mkPlan :: LStmt Name -> TcM PlanResult
1106 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
1107 = do { uniq <- newUnique -- is treated very specially
1108 ; let fresh_it = itName uniq
1109 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
1110 matches = [mkMatch [] expr emptyLocalBinds]
1111 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
1112 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
1113 (HsVar bindIOName) noSyntaxExpr
1114 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
1115 (HsVar thenIOName) placeHolderType
1118 -- [it <- e; print it] but not if it::()
1120 -- [let it = e; print it]
1121 ; runPlans [ -- Plan A
1122 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
1123 ; it_ty <- zonkTcType (idType it_id)
1124 ; when (isUnitTy it_ty) failM
1127 -- Plan B; a naked bind statment
1128 tcGhciStmts [bind_stmt],
1130 -- Plan C; check that the let-binding is typeable all by itself.
1131 -- If not, fail; if so, try to print it.
1132 -- The two-step process avoids getting two errors: one from
1133 -- the expression itself, and one from the 'print it' part
1134 -- This two-step story is very clunky, alas
1135 do { checkNoErrs (tcGhciStmts [let_stmt])
1136 --- checkNoErrs defeats the error recovery of let-bindings
1137 ; tcGhciStmts [let_stmt, print_it] }
1140 mkPlan stmt@(L loc (BindStmt {}))
1141 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
1142 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
1143 (HsVar thenIOName) placeHolderType
1145 ; print_bind_result <- doptM Opt_PrintBindResult
1146 ; let print_plan = do
1147 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1148 ; v_ty <- zonkTcType (idType v_id)
1149 ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM
1153 -- [stmt; print v] but not if v::()
1155 ; runPlans ((if print_bind_result then [print_plan] else []) ++
1156 [tcGhciStmts [stmt]])
1160 = tcGhciStmts [stmt]
1162 ---------------------------
1163 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1165 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1166 ret_id <- tcLookupId returnIOName ; -- return @ IO
1168 ret_ty = mkListTy unitTy ;
1169 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1170 tc_io_stmts stmts = tcStmts DoExpr tcDoStmt stmts io_ret_ty ;
1172 names = map unLoc (collectLStmtsBinders stmts) ;
1174 -- mk_return builds the expression
1175 -- returnIO @ [()] [coerce () x, .., coerce () z]
1177 -- Despite the inconvenience of building the type applications etc,
1178 -- this *has* to be done in type-annotated post-typecheck form
1179 -- because we are going to return a list of *polymorphic* values
1180 -- coerced to type (). If we built a *source* stmt
1181 -- return [coerce x, ..., coerce z]
1182 -- then the type checker would instantiate x..z, and we wouldn't
1183 -- get their *polymorphic* values. (And we'd get ambiguity errs
1184 -- if they were overloaded, since they aren't applied to anything.)
1185 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1186 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1187 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1191 -- OK, we're ready to typecheck the stmts
1192 traceTc (text "TcRnDriver.tcGhciStmts: tc stmts") ;
1193 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1194 mapM tcLookupId names ;
1195 -- Look up the names right in the middle,
1196 -- where they will all be in scope
1198 -- Simplify the context
1199 traceTc (text "TcRnDriver.tcGhciStmts: simplify ctxt") ;
1200 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1201 -- checkNoErrs ensures that the plan fails if context redn fails
1203 traceTc (text "TcRnDriver.tcGhciStmts: done") ;
1204 return (ids, mkHsDictLet const_binds $
1205 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1210 tcRnExpr just finds the type of an expression
1214 -> InteractiveContext
1217 tcRnExpr hsc_env ictxt rdr_expr
1218 = initTcPrintErrors hsc_env iNTERACTIVE $
1219 setInteractiveContext hsc_env ictxt $ do {
1221 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1224 -- Now typecheck the expression;
1225 -- it might have a rank-2 type (e.g. :t runST)
1226 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1227 ((qtvs, dict_insts, _), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1228 tcSimplifyInteractive lie_top ;
1230 let { all_expr_ty = mkForAllTys qtvs $
1231 mkFunTys (map (idType . instToId) dict_insts) $
1233 zonkTcType all_expr_ty
1236 smpl_doc = ptext (sLit "main expression")
1239 tcRnType just finds the kind of a type
1243 -> InteractiveContext
1246 tcRnType hsc_env ictxt rdr_type
1247 = initTcPrintErrors hsc_env iNTERACTIVE $
1248 setInteractiveContext hsc_env ictxt $ do {
1250 rn_type <- rnLHsType doc rdr_type ;
1253 -- Now kind-check the type
1254 (ty', kind) <- kcHsType rn_type ;
1258 doc = ptext (sLit "In GHCi input")
1264 %************************************************************************
1266 More GHCi stuff, to do with browsing and getting info
1268 %************************************************************************
1272 -- ASSUMES that the module is either in the HomePackageTable or is
1273 -- a package module with an interface on disk. If neither of these is
1274 -- true, then the result will be an error indicating the interface
1275 -- could not be found.
1276 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe [AvailInfo])
1277 getModuleExports hsc_env mod
1280 checkMods = ic_toplev_scope ic ++ ic_exports ic
1282 initTc hsc_env HsSrcFile False iNTERACTIVE (tcGetModuleExports mod checkMods)
1284 -- Get the export avail info and also load all orphan and family-instance
1285 -- modules. Finally, check that the family instances of all modules in the
1286 -- interactive context are consistent (these modules are in the second
1288 tcGetModuleExports :: Module -> [Module] -> TcM [AvailInfo]
1289 tcGetModuleExports mod directlyImpMods
1290 = do { let doc = ptext (sLit "context for compiling statements")
1291 ; iface <- initIfaceTcRn $ loadSysInterface doc mod
1293 -- Load any orphan-module and family instance-module
1294 -- interfaces, so their instances are visible.
1295 ; loadOrphanModules (dep_orphs (mi_deps iface)) False
1296 ; loadOrphanModules (dep_finsts (mi_deps iface)) True
1298 -- Check that the family instances of all directly loaded
1299 -- modules are consistent.
1300 ; checkFamInstConsistency (dep_finsts (mi_deps iface)) directlyImpMods
1302 ; ifaceExportNames (mi_exports iface)
1305 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1306 tcRnLookupRdrName hsc_env rdr_name
1307 = initTcPrintErrors hsc_env iNTERACTIVE $
1308 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1309 lookup_rdr_name rdr_name
1311 lookup_rdr_name rdr_name = do {
1312 -- If the identifier is a constructor (begins with an
1313 -- upper-case letter), then we need to consider both
1314 -- constructor and type class identifiers.
1315 let { rdr_names = dataTcOccs rdr_name } ;
1317 -- results :: [Either Messages Name]
1318 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1320 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1321 -- The successful lookups will be (Just name)
1322 let { (warns_s, good_names) = unzip [ (msgs, name)
1323 | (msgs, Just name) <- results] ;
1324 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1326 -- Fail if nothing good happened, else add warnings
1327 if null good_names then
1328 -- No lookup succeeded, so
1329 -- pick the first error message and report it
1330 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1331 -- while the other is "X is not in scope",
1332 -- we definitely want the former; but we might pick the latter
1333 do { addMessages (head errs_s) ; failM }
1334 else -- Add deprecation warnings
1335 mapM_ addMessages warns_s ;
1340 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1341 tcRnLookupName hsc_env name
1342 = initTcPrintErrors hsc_env iNTERACTIVE $
1343 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1344 tcRnLookupName' name
1346 -- To look up a name we have to look in the local environment (tcl_lcl)
1347 -- as well as the global environment, which is what tcLookup does.
1348 -- But we also want a TyThing, so we have to convert:
1350 tcRnLookupName' :: Name -> TcRn TyThing
1351 tcRnLookupName' name = do
1352 tcthing <- tcLookup name
1354 AGlobal thing -> return thing
1355 ATcId{tct_id=id} -> return (AnId id)
1356 _ -> panic "tcRnLookupName'"
1358 tcRnGetInfo :: HscEnv
1360 -> IO (Maybe (TyThing, Fixity, [Instance]))
1362 -- Used to implemnent :info in GHCi
1364 -- Look up a RdrName and return all the TyThings it might be
1365 -- A capitalised RdrName is given to us in the DataName namespace,
1366 -- but we want to treat it as *both* a data constructor
1367 -- *and* as a type or class constructor;
1368 -- hence the call to dataTcOccs, and we return up to two results
1369 tcRnGetInfo hsc_env name
1370 = initTcPrintErrors hsc_env iNTERACTIVE $
1371 let ictxt = hsc_IC hsc_env in
1372 setInteractiveContext hsc_env ictxt $ do
1374 -- Load the interface for all unqualified types and classes
1375 -- That way we will find all the instance declarations
1376 -- (Packages have not orphan modules, and we assume that
1377 -- in the home package all relevant modules are loaded.)
1378 loadUnqualIfaces ictxt
1380 thing <- tcRnLookupName' name
1381 fixity <- lookupFixityRn name
1382 ispecs <- lookupInsts thing
1383 return (thing, fixity, ispecs)
1385 lookupInsts :: TyThing -> TcM [Instance]
1386 lookupInsts (AClass cls)
1387 = do { inst_envs <- tcGetInstEnvs
1388 ; return (classInstances inst_envs cls) }
1390 lookupInsts (ATyCon tc)
1391 = do { eps <- getEps -- Load all instances for all classes that are
1392 -- in the type environment (which are all the ones
1393 -- we've seen in any interface file so far)
1394 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1396 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1397 , let dfun = instanceDFunId ispec
1400 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1401 tc_name = tyConName tc
1403 lookupInsts other = return []
1405 loadUnqualIfaces :: InteractiveContext -> TcM ()
1406 -- Load the home module for everything that is in scope unqualified
1407 -- This is so that we can accurately report the instances for
1409 loadUnqualIfaces ictxt
1411 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1413 unqual_mods = [ nameModule name
1414 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1415 let name = gre_name gre,
1416 not (isInternalName name),
1417 isTcOcc (nameOccName name), -- Types and classes only
1418 unQualOK gre ] -- In scope unqualified
1419 doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified")
1423 %************************************************************************
1427 %************************************************************************
1430 rnDump :: SDoc -> TcRn ()
1431 -- Dump, with a banner, if -ddump-rn
1432 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1434 tcDump :: TcGblEnv -> TcRn ()
1436 = do { dflags <- getDOpts ;
1438 -- Dump short output if -ddump-types or -ddump-tc
1439 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1440 (dumpTcRn short_dump) ;
1442 -- Dump bindings if -ddump-tc
1443 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1446 short_dump = pprTcGblEnv env
1447 full_dump = pprLHsBinds (tcg_binds env)
1448 -- NB: foreign x-d's have undefined's in their types;
1449 -- hence can't show the tc_fords
1452 = do { dflags <- getDOpts ;
1453 when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1454 (dumpTcRn (pprModGuts mod_guts)) ;
1456 -- Dump bindings if -ddump-tc
1457 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1459 full_dump = pprCoreBindings (mg_binds mod_guts)
1461 -- It's unpleasant having both pprModGuts and pprModDetails here
1462 pprTcGblEnv :: TcGblEnv -> SDoc
1463 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1465 tcg_fam_insts = fam_insts,
1467 tcg_imports = imports })
1468 = vcat [ ppr_types insts type_env
1469 , ppr_tycons fam_insts type_env
1471 , ppr_fam_insts fam_insts
1472 , vcat (map ppr rules)
1473 , ppr_gen_tycons (typeEnvTyCons type_env)
1474 , ptext (sLit "Dependent modules:") <+>
1475 ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports))
1476 , ptext (sLit "Dependent packages:") <+>
1477 ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)]
1478 where -- The two uses of sortBy are just to reduce unnecessary
1479 -- wobbling in testsuite output
1480 cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2)
1481 = (mod_name1 `stableModuleNameCmp` mod_name2)
1483 (is_boot1 `compare` is_boot2)
1485 pprModGuts :: ModGuts -> SDoc
1486 pprModGuts (ModGuts { mg_types = type_env,
1488 = vcat [ ppr_types [] type_env,
1491 ppr_types :: [Instance] -> TypeEnv -> SDoc
1492 ppr_types insts type_env
1493 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1495 dfun_ids = map instanceDFunId insts
1496 ids = [id | id <- typeEnvIds type_env, want_sig id]
1497 want_sig id | opt_PprStyle_Debug = True
1498 | otherwise = isLocalId id &&
1499 isExternalName (idName id) &&
1500 not (id `elem` dfun_ids)
1501 -- isLocalId ignores data constructors, records selectors etc.
1502 -- The isExternalName ignores local dictionary and method bindings
1503 -- that the type checker has invented. Top-level user-defined things
1504 -- have External names.
1506 ppr_tycons :: [FamInst] -> TypeEnv -> SDoc
1507 ppr_tycons fam_insts type_env
1508 = text "TYPE CONSTRUCTORS" $$ nest 4 (ppr_tydecls tycons)
1510 fi_tycons = map famInstTyCon fam_insts
1511 tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon]
1512 want_tycon tycon | opt_PprStyle_Debug = True
1513 | otherwise = not (isImplicitTyCon tycon) &&
1514 isExternalName (tyConName tycon) &&
1515 not (tycon `elem` fi_tycons)
1517 ppr_insts :: [Instance] -> SDoc
1518 ppr_insts [] = empty
1519 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1521 ppr_fam_insts :: [FamInst] -> SDoc
1522 ppr_fam_insts [] = empty
1523 ppr_fam_insts fam_insts =
1524 text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts)
1526 ppr_sigs :: [Var] -> SDoc
1528 -- Print type signatures; sort by OccName
1529 = vcat (map ppr_sig (sortLe le_sig ids))
1531 le_sig id1 id2 = getOccName id1 <= getOccName id2
1532 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1534 ppr_tydecls :: [TyCon] -> SDoc
1536 -- Print type constructor info; sort by OccName
1537 = vcat (map ppr_tycon (sortLe le_sig tycons))
1539 le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2
1541 | isCoercionTyCon tycon = ptext (sLit "coercion") <+> ppr tycon
1542 | otherwise = ppr (tyThingToIfaceDecl (ATyCon tycon))
1544 ppr_rules :: [CoreRule] -> SDoc
1545 ppr_rules [] = empty
1546 ppr_rules rs = vcat [ptext (sLit "{-# RULES"),
1547 nest 4 (pprRules rs),
1550 ppr_gen_tycons [] = empty
1551 ppr_gen_tycons tcs = vcat [ptext (sLit "Tycons with generics:"),
1552 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]