2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[TcModule]{Typechecking a whole module}
9 tcRnStmt, tcRnExpr, tcRnType,
20 #include "HsVersions.h"
24 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
27 import DynFlags ( DynFlag(..), DynFlags(..), dopt, GhcMode(..) )
28 import StaticFlags ( opt_PprStyle_Debug )
29 import Packages ( checkForPackageConflicts, mkHomeModules )
30 import HsSyn ( HsModule(..), HsExtCore(..), HsGroup(..), LHsDecl,
31 SpliceDecl(..), HsBind(..), LHsBinds,
32 emptyRdrGroup, emptyRnGroup, appendGroups, plusHsValBinds,
33 nlHsApp, nlHsVar, pprLHsBinds )
34 import RdrHsSyn ( findSplice )
36 import PrelNames ( runMainIOName, rootMainKey, rOOT_MAIN, mAIN,
38 import RdrName ( RdrName, mkRdrUnqual, emptyGlobalRdrEnv )
39 import TcHsSyn ( zonkTopDecls )
40 import TcExpr ( tcInferRho )
42 import TcType ( tidyTopType, tcEqType, mkTyVarTys, substTyWith )
43 import Inst ( showLIE )
44 import InstEnv ( extendInstEnvList, Instance, pprInstances, instanceDFunId )
45 import TcBinds ( tcTopBinds, tcHsBootSigs )
46 import TcDefaults ( tcDefaults )
47 import TcEnv ( tcExtendGlobalValEnv, iDFunId )
48 import TcRules ( tcRules )
49 import TcForeign ( tcForeignImports, tcForeignExports )
50 import TcInstDcls ( tcInstDecls1, tcInstDecls2 )
51 import TcIface ( tcExtCoreBindings, tcHiBootIface )
52 import TcSimplify ( tcSimplifyTop )
53 import TcTyClsDecls ( tcTyAndClassDecls )
54 import LoadIface ( loadOrphanModules )
55 import RnNames ( importsFromLocalDecls, rnImports, rnExports,
56 reportUnusedNames, reportDeprecations )
57 import RnEnv ( lookupSrcOcc_maybe )
58 import RnSource ( rnSrcDecls, rnTyClDecls, checkModDeprec )
59 import PprCore ( pprRules, pprCoreBindings )
60 import CoreSyn ( CoreRule, bindersOfBinds )
61 import DataCon ( dataConWrapId )
62 import ErrUtils ( Messages, mkDumpDoc, showPass )
63 import Id ( Id, mkExportedLocalId, isLocalId, idName, idType )
65 import Module ( Module, ModuleEnv, mkModule, moduleEnvElts, elemModuleEnv )
66 import OccName ( mkVarOcc, mkOccFS, varName )
67 import Name ( Name, NamedThing(..), isExternalName, getSrcLoc, isWiredInName,
70 import TyCon ( tyConHasGenerics, isSynTyCon, getSynTyConDefn, tyConKind )
71 import SrcLoc ( srcLocSpan, Located(..), noLoc )
72 import DriverPhases ( HscSource(..), isHsBoot )
73 import HscTypes ( ModGuts(..), ModDetails(..), emptyModDetails,
74 HscEnv(..), ExternalPackageState(..),
75 IsBootInterface, noDependencies,
76 Deprecs( NoDeprecs ), plusDeprecs,
77 ForeignStubs(NoStubs), TyThing(..),
78 TypeEnv, lookupTypeEnv, hptInstances,
79 extendTypeEnvWithIds, typeEnvIds, typeEnvTyCons, typeEnvElts,
85 import HsSyn ( HsStmtContext(..), Stmt(..), HsExpr(..),
86 HsLocalBinds(..), HsValBinds(..),
87 LStmt, LHsExpr, LHsType, mkMatchGroup, mkMatch, emptyLocalBinds,
88 collectLStmtsBinders, collectLStmtBinders, nlVarPat,
89 placeHolderType, noSyntaxExpr )
90 import RdrName ( GlobalRdrElt(..), globalRdrEnvElts,
91 unQualOK, lookupLocalRdrEnv, extendLocalRdrEnv )
92 import RnSource ( addTcgDUs )
93 import TcHsSyn ( mkHsDictLet, zonkTopLExpr, zonkTopBndrs )
94 import TcHsType ( kcHsType )
95 import TcMType ( zonkTcType, zonkQuantifiedTyVar )
96 import TcMatches ( tcStmts, tcDoStmt )
97 import TcSimplify ( tcSimplifyInteractive, tcSimplifyInfer )
98 import TcType ( Type, mkForAllTys, mkFunTys, mkTyConApp, tyVarsOfType, isTauTy,
99 isUnLiftedType, tyClsNamesOfDFunHead, tyClsNamesOfType, isUnitTy )
100 import TcEnv ( tcLookupTyCon, tcLookupId, tcLookupGlobal )
101 import RnTypes ( rnLHsType )
102 import Inst ( tcGetInstEnvs )
103 import InstEnv ( classInstances, instEnvElts )
104 import RnExpr ( rnStmts, rnLExpr )
105 import LoadIface ( loadSrcInterface, loadSysInterface )
106 import IfaceEnv ( ifaceExportNames )
107 import Module ( moduleSetElts, mkModuleSet )
108 import RnEnv ( lookupOccRn, dataTcOccs, lookupFixityRn )
109 import Id ( setIdType )
110 import MkId ( unsafeCoerceId )
111 import TyCon ( tyConName )
112 import TysWiredIn ( mkListTy, unitTy )
113 import IdInfo ( GlobalIdDetails(..) )
115 import Var ( globaliseId )
116 import Name ( nameOccName, nameModule, isBuiltInSyntax )
117 import OccName ( isTcOcc )
118 import NameEnv ( delListFromNameEnv )
119 import PrelNames ( iNTERACTIVE, ioTyConName, printName, itName,
120 bindIOName, thenIOName, returnIOName )
121 import HscTypes ( InteractiveContext(..),
122 ModIface(..), icPrintUnqual,
124 import BasicTypes ( Fixity )
125 import SrcLoc ( unLoc )
128 import FastString ( mkFastString )
129 import Maybes ( MaybeErr(..) )
130 import Util ( sortLe )
131 import Bag ( unionBags, snocBag, emptyBag, unitBag, unionManyBags )
133 import Maybe ( isJust )
138 %************************************************************************
140 Typecheck and rename a module
142 %************************************************************************
148 -> Bool -- True <=> save renamed syntax
149 -> Located (HsModule RdrName)
150 -> IO (Messages, Maybe TcGblEnv)
152 tcRnModule hsc_env hsc_src save_rn_decls
153 (L loc (HsModule maybe_mod export_ies
154 import_decls local_decls mod_deprec))
155 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
157 let { this_mod = case maybe_mod of
158 Nothing -> mAIN -- 'module M where' is omitted
159 Just (L _ mod) -> mod } ; -- The normal case
161 initTc hsc_env hsc_src this_mod $
164 -- Deal with imports; sets tcg_rdr_env, tcg_imports
165 (rdr_env, imports) <- rnImports import_decls ;
167 let { dep_mods :: ModuleEnv (Module, IsBootInterface)
168 ; dep_mods = imp_dep_mods imports
170 -- We want instance declarations from all home-package
171 -- modules below this one, including boot modules, except
172 -- ourselves. The 'except ourselves' is so that we don't
173 -- get the instances from this module's hs-boot file
174 ; want_instances :: Module -> Bool
175 ; want_instances mod = mod `elemModuleEnv` dep_mods
177 ; home_insts = hptInstances hsc_env want_instances
180 -- Record boot-file info in the EPS, so that it's
181 -- visible to loadHiBootInterface in tcRnSrcDecls,
182 -- and any other incrementally-performed imports
183 updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
185 checkConflicts imports this_mod $ do {
187 -- Update the gbl env
189 gbl { tcg_rdr_env = rdr_env,
190 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
191 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
192 tcg_rn_decls = if save_rn_decls then
198 traceRn (text "rn1" <+> ppr (imp_dep_mods imports)) ;
199 -- Fail if there are any errors so far
200 -- The error printing (if needed) takes advantage
201 -- of the tcg_env we have now set
204 -- Load any orphan-module interfaces, so that
205 -- their rules and instance decls will be found
206 loadOrphanModules (imp_orphs imports) ;
208 traceRn (text "rn1a") ;
209 -- Rename and type check the declarations
210 tcg_env <- if isHsBoot hsc_src then
211 tcRnHsBootDecls local_decls
213 tcRnSrcDecls local_decls ;
214 setGblEnv tcg_env $ do {
216 traceRn (text "rn3") ;
218 -- Report the use of any deprecated things
219 -- We do this before processsing the export list so
220 -- that we don't bleat about re-exporting a deprecated
221 -- thing (especially via 'module Foo' export item)
222 -- Only uses in the body of the module are complained about
223 reportDeprecations tcg_env ;
225 -- Process the export list
226 exports <- rnExports (isJust maybe_mod) export_ies ;
228 -- Check whether the entire module is deprecated
229 -- This happens only once per module
230 let { mod_deprecs = checkModDeprec mod_deprec } ;
232 -- Add exports and deprecations to envt
233 let { final_env = tcg_env { tcg_exports = exports,
234 tcg_dus = tcg_dus tcg_env `plusDU` usesOnly exports,
235 tcg_deprecs = tcg_deprecs tcg_env `plusDeprecs`
237 -- A module deprecation over-rides the earlier ones
240 -- Report unused names
241 reportUnusedNames export_ies final_env ;
243 -- Dump output and return
249 -- The program is not allowed to contain two modules with the same
250 -- name, and we check for that here. It could happen if the home package
251 -- contains a module that is also present in an external package, for example.
252 checkConflicts imports this_mod and_then = do
255 dep_mods = this_mod : map fst (moduleEnvElts (imp_dep_mods imports))
256 -- don't forget to include the current module!
258 mb_dep_pkgs = checkForPackageConflicts
259 dflags dep_mods (imp_dep_pkgs imports)
265 updGblEnv (\gbl -> gbl{ tcg_home_mods = mkHomeModules dep_mods })
270 %************************************************************************
272 Type-checking external-core modules
274 %************************************************************************
277 tcRnExtCore :: HscEnv
279 -> IO (Messages, Maybe ModGuts)
280 -- Nothing => some error occurred
282 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
283 -- The decls are IfaceDecls; all names are original names
284 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
286 initTc hsc_env ExtCoreFile this_mod $ do {
288 let { ldecls = map noLoc decls } ;
290 -- Deal with the type declarations; first bring their stuff
291 -- into scope, then rname them, then type check them
292 tcg_env <- importsFromLocalDecls (mkFakeGroup ldecls) ;
294 setGblEnv tcg_env $ do {
296 rn_decls <- rnTyClDecls ldecls ;
299 -- Dump trace of renaming part
300 rnDump (ppr rn_decls) ;
302 -- Typecheck them all together so that
303 -- any mutually recursive types are done right
304 tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails rn_decls) ;
305 -- Make the new type env available to stuff slurped from interface files
307 setGblEnv tcg_env $ do {
309 -- Now the core bindings
310 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
314 bndrs = bindersOfBinds core_binds ;
315 my_exports = mkNameSet (map idName bndrs) ;
316 -- ToDo: export the data types also?
318 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
320 mod_guts = ModGuts { mg_module = this_mod,
322 mg_usages = [], -- ToDo: compute usage
323 mg_dir_imps = [], -- ??
324 mg_deps = noDependencies, -- ??
325 mg_home_mods = mkHomeModules [], -- ?? wrong!!
326 mg_exports = my_exports,
327 mg_types = final_type_env,
328 mg_insts = tcg_insts tcg_env,
330 mg_binds = core_binds,
333 mg_rdr_env = emptyGlobalRdrEnv,
334 mg_fix_env = emptyFixityEnv,
335 mg_deprecs = NoDeprecs,
339 tcCoreDump mod_guts ;
344 mkFakeGroup decls -- Rather clumsy; lots of unused fields
345 = emptyRdrGroup { hs_tyclds = decls }
349 %************************************************************************
351 Type-checking the top level of a module
353 %************************************************************************
356 tcRnSrcDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
357 -- Returns the variables free in the decls
358 -- Reason: solely to report unused imports and bindings
360 = do { -- Load the hi-boot interface for this module, if any
361 -- We do this now so that the boot_names can be passed
362 -- to tcTyAndClassDecls, because the boot_names are
363 -- automatically considered to be loop breakers
365 boot_iface <- tcHiBootIface mod ;
367 -- Do all the declarations
368 (tc_envs, lie) <- getLIE (tc_rn_src_decls boot_iface decls) ;
370 -- tcSimplifyTop deals with constant or ambiguous InstIds.
371 -- How could there be ambiguous ones? They can only arise if a
372 -- top-level decl falls under the monomorphism
373 -- restriction, and no subsequent decl instantiates its
374 -- type. (Usually, ambiguous type variables are resolved
375 -- during the generalisation step.)
376 traceTc (text "Tc8") ;
377 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
378 -- Setting the global env exposes the instances to tcSimplifyTop
379 -- Setting the local env exposes the local Ids to tcSimplifyTop,
380 -- so that we get better error messages (monomorphism restriction)
382 -- Backsubstitution. This must be done last.
383 -- Even tcSimplifyTop may do some unification.
384 traceTc (text "Tc9") ;
385 let { (tcg_env, _) = tc_envs ;
386 TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
387 tcg_rules = rules, tcg_fords = fords } = tcg_env } ;
389 (bind_ids, binds', fords', rules') <- zonkTopDecls (binds `unionBags` inst_binds)
392 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
393 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
396 tcg_fords = fords' } } ;
398 -- Make the new type env available to stuff slurped from interface files
399 writeMutVar (tcg_type_env_var tcg_env) final_type_env ;
401 -- Compare the hi-boot iface (if any) with the real thing
402 dfun_binds <- checkHiBootIface tcg_env' boot_iface ;
404 return (tcg_env' { tcg_binds = tcg_binds tcg_env' `unionBags` dfun_binds })
407 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
408 -- Loops around dealing with each top level inter-splice group
409 -- in turn, until it's dealt with the entire module
410 tc_rn_src_decls boot_details ds
411 = do { let { (first_group, group_tail) = findSplice ds } ;
412 -- If ds is [] we get ([], Nothing)
414 -- Type check the decls up to, but not including, the first splice
415 tc_envs@(tcg_env,tcl_env) <- tcRnGroup boot_details first_group ;
417 -- Bale out if errors; for example, error recovery when checking
418 -- the RHS of 'main' can mean that 'main' is not in the envt for
419 -- the subsequent checkMain test
424 -- If there is no splice, we're nearly done
426 Nothing -> do { -- Last thing: check for `main'
427 tcg_env <- checkMain ;
428 return (tcg_env, tcl_env)
431 -- If there's a splice, we must carry on
432 Just (SpliceDecl splice_expr, rest_ds) -> do {
434 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
437 -- Rename the splice expression, and get its supporting decls
438 (rn_splice_expr, splice_fvs) <- rnLExpr splice_expr ;
439 failIfErrsM ; -- Don't typecheck if renaming failed
441 -- Execute the splice
442 spliced_decls <- tcSpliceDecls rn_splice_expr ;
444 -- Glue them on the front of the remaining decls and loop
445 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
446 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
451 %************************************************************************
453 Compiling hs-boot source files, and
454 comparing the hi-boot interface with the real thing
456 %************************************************************************
459 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
460 tcRnHsBootDecls decls
461 = do { let { (first_group, group_tail) = findSplice decls }
464 Just stuff -> spliceInHsBootErr stuff
467 -- Rename the declarations
468 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
469 ; setGblEnv tcg_env $ do {
471 -- Todo: check no foreign decls, no rules, no default decls
473 -- Typecheck type/class decls
474 ; traceTc (text "Tc2")
475 ; let tycl_decls = hs_tyclds rn_group
476 ; tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails tycl_decls)
477 ; setGblEnv tcg_env $ do {
479 -- Typecheck instance decls
480 ; traceTc (text "Tc3")
481 ; (tcg_env, inst_infos, _binds) <- tcInstDecls1 tycl_decls (hs_instds rn_group)
482 ; setGblEnv tcg_env $ do {
484 -- Typecheck value declarations
485 ; traceTc (text "Tc5")
486 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
489 -- No simplification or zonking to do
490 ; traceTc (text "Tc7a")
491 ; gbl_env <- getGblEnv
493 -- Make the final type-env
494 -- Include the dfun_ids so that their type sigs get
495 -- are written into the interface file
496 ; let { type_env0 = tcg_type_env gbl_env
497 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
498 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
499 ; dfun_ids = map iDFunId inst_infos }
500 ; return (gbl_env { tcg_type_env = type_env2 })
503 spliceInHsBootErr (SpliceDecl (L loc _), _)
504 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
507 Once we've typechecked the body of the module, we want to compare what
508 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
511 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM (LHsBinds Id)
512 -- Compare the hi-boot file for this module (if there is one)
513 -- with the type environment we've just come up with
514 -- In the common case where there is no hi-boot file, the list
515 -- of boot_names is empty.
517 -- The bindings we return give bindings for the dfuns defined in the
518 -- hs-boot file, such as $fbEqT = $fEqT
521 (TcGblEnv { tcg_insts = local_insts, tcg_type_env = local_type_env })
522 (ModDetails { md_insts = boot_insts, md_types = boot_type_env })
523 = do { mapM_ check_one (typeEnvElts boot_type_env)
524 ; dfun_binds <- mapM check_inst boot_insts
525 ; return (unionManyBags dfun_binds) }
531 = case lookupTypeEnv local_type_env name of
532 Nothing -> addErrTc (missingBootThing boot_thing)
533 Just real_thing -> check_thing boot_thing real_thing
535 name = getName boot_thing
537 no_check name = isWiredInName name -- No checking for wired-in names. In particular,
538 -- 'error' is handled by a rather gross hack
539 -- (see comments in GHC.Err.hs-boot)
540 || name `elem` dfun_names
541 dfun_names = map getName boot_insts
544 = case [dfun | inst <- local_insts,
545 let dfun = instanceDFunId inst,
546 idType dfun `tcEqType` boot_inst_ty ] of
547 [] -> do { addErrTc (instMisMatch boot_inst); return emptyBag }
548 (dfun:_) -> return (unitBag $ noLoc $ VarBind local_boot_dfun (nlHsVar dfun))
550 boot_dfun = instanceDFunId boot_inst
551 boot_inst_ty = idType boot_dfun
552 local_boot_dfun = mkExportedLocalId (idName boot_dfun) boot_inst_ty
555 check_thing (ATyCon boot_tc) (ATyCon real_tc)
556 | isSynTyCon boot_tc && isSynTyCon real_tc,
557 defn1 `tcEqType` substTyWith tvs2 (mkTyVarTys tvs1) defn2
560 | tyConKind boot_tc == tyConKind real_tc
563 (tvs1, defn1) = getSynTyConDefn boot_tc
564 (tvs2, defn2) = getSynTyConDefn boot_tc
566 check_thing (AnId boot_id) (AnId real_id)
567 | idType boot_id `tcEqType` idType real_id
570 check_thing (ADataCon dc1) (ADataCon dc2)
571 | idType (dataConWrapId dc1) `tcEqType` idType (dataConWrapId dc2)
574 -- Can't declare a class in a hi-boot file
576 check_thing boot_thing real_thing -- Default case; failure
577 = addErrAt (srcLocSpan (getSrcLoc real_thing))
578 (bootMisMatch real_thing)
581 missingBootThing thing
582 = ppr thing <+> ptext SLIT("is defined in the hs-boot file, but not in the module")
584 = ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file")
587 2 (ptext SLIT("is defined in the hs-boot file, but not in the module"))
591 %************************************************************************
593 Type-checking the top level of a module
595 %************************************************************************
597 tcRnGroup takes a bunch of top-level source-code declarations, and
599 * gets supporting declarations from interface files
602 * and augments the TcGblEnv with the results
604 In Template Haskell it may be called repeatedly for each group of
605 declarations. It expects there to be an incoming TcGblEnv in the
606 monad; it augments it and returns the new TcGblEnv.
609 tcRnGroup :: ModDetails -> HsGroup RdrName -> TcM (TcGblEnv, TcLclEnv)
610 -- Returns the variables free in the decls, for unused-binding reporting
611 tcRnGroup boot_details decls
612 = do { -- Rename the declarations
613 (tcg_env, rn_decls) <- rnTopSrcDecls decls ;
614 setGblEnv tcg_env $ do {
616 -- Typecheck the declarations
617 tcTopSrcDecls boot_details rn_decls
620 ------------------------------------------------
621 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
623 = do { -- Bring top level binders into scope
624 tcg_env <- importsFromLocalDecls group ;
625 setGblEnv tcg_env $ do {
627 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
629 -- Rename the source decls
630 (tcg_env, rn_decls) <- rnSrcDecls group ;
633 -- save the renamed syntax, if we want it
635 | Just grp <- tcg_rn_decls tcg_env
636 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
640 -- Dump trace of renaming part
641 rnDump (ppr rn_decls) ;
643 return (tcg_env', rn_decls)
646 ------------------------------------------------
647 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
648 tcTopSrcDecls boot_details
649 (HsGroup { hs_tyclds = tycl_decls,
650 hs_instds = inst_decls,
651 hs_fords = foreign_decls,
652 hs_defds = default_decls,
653 hs_ruleds = rule_decls,
654 hs_valds = val_binds })
655 = do { -- Type-check the type and class decls, and all imported decls
656 -- The latter come in via tycl_decls
657 traceTc (text "Tc2") ;
659 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
660 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
661 -- an error we'd better stop now, to avoid a cascade
663 -- Make these type and class decls available to stuff slurped from interface files
664 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
667 setGblEnv tcg_env $ do {
668 -- Source-language instances, including derivings,
669 -- and import the supporting declarations
670 traceTc (text "Tc3") ;
671 (tcg_env, inst_infos, deriv_binds) <- tcInstDecls1 tycl_decls inst_decls ;
672 setGblEnv tcg_env $ do {
674 -- Foreign import declarations next. No zonking necessary
675 -- here; we can tuck them straight into the global environment.
676 traceTc (text "Tc4") ;
677 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
678 tcExtendGlobalValEnv fi_ids $ do {
680 -- Default declarations
681 traceTc (text "Tc4a") ;
682 default_tys <- tcDefaults default_decls ;
683 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
685 -- Value declarations next
686 -- We also typecheck any extra binds that came out
687 -- of the "deriving" process (deriv_binds)
688 traceTc (text "Tc5") ;
689 (tc_val_binds, tcl_env) <- tcTopBinds (val_binds `plusHsValBinds` deriv_binds) ;
690 setLclTypeEnv tcl_env $ do {
692 -- Second pass over class and instance declarations,
693 traceTc (text "Tc6") ;
694 (inst_binds, tcl_env) <- tcInstDecls2 tycl_decls inst_infos ;
695 showLIE (text "after instDecls2") ;
698 -- They need to be zonked, so we return them
699 traceTc (text "Tc7") ;
700 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
703 rules <- tcRules rule_decls ;
706 traceTc (text "Tc7a") ;
707 tcg_env <- getGblEnv ;
708 let { all_binds = tc_val_binds `unionBags`
709 inst_binds `unionBags`
712 -- Extend the GblEnv with the (as yet un-zonked)
713 -- bindings, rules, foreign decls
714 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
715 tcg_rules = tcg_rules tcg_env ++ rules,
716 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
717 return (tcg_env', tcl_env)
722 %************************************************************************
726 %************************************************************************
729 checkMain :: TcM TcGblEnv
730 -- If we are in module Main, check that 'main' is defined.
732 = do { ghci_mode <- getGhciMode ;
733 tcg_env <- getGblEnv ;
735 let { main_mod = case mainModIs dflags of {
736 Just mod -> mkModule mod ;
738 main_fn = case mainFunIs dflags of {
739 Just fn -> mkRdrUnqual (mkVarOcc (mkFastString fn)) ;
740 Nothing -> main_RDR_Unqual } } ;
742 check_main ghci_mode tcg_env main_mod main_fn
746 check_main ghci_mode tcg_env main_mod main_fn
748 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
752 = addErrCtxt mainCtxt $
753 do { mb_main <- lookupSrcOcc_maybe main_fn
754 -- Check that 'main' is in scope
755 -- It might be imported from another module!
757 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
761 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
762 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
763 -- :Main.main :: IO () = runMainIO main
765 ; (main_expr, ty) <- setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
768 -- The function that the RTS invokes is always :Main.main,
769 -- which we call root_main_id.
770 -- (Because GHC allows the user to have a module not called
771 -- Main as the main module, we can't rely on the main function
772 -- being called "Main.main". That's why root_main_id has a fixed
774 -- We also make root_main_id an implicit Id, by making main_name
775 -- its parent (hence (Just main_name)). That has the effect
776 -- of preventing its type and unfolding from getting out into
777 -- the interface file. Otherwise we can end up with two defns
778 -- for 'main' in the interface file!
780 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
781 (mkOccFS varName FSLIT("main"))
782 (Just main_name) (getSrcLoc main_name)
783 ; root_main_id = mkExportedLocalId root_main_name ty
784 ; main_bind = noLoc (VarBind root_main_id main_expr) }
786 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
788 tcg_dus = tcg_dus tcg_env
789 `plusDU` usesOnly (unitFV main_name)
790 -- Record the use of 'main', so that we don't
791 -- complain about it being defined but not used
795 mod = tcg_mod tcg_env
797 complain_no_main | ghci_mode == Interactive = return ()
798 | otherwise = failWithTc noMainMsg
799 -- In interactive mode, don't worry about the absence of 'main'
800 -- In other modes, fail altogether, so that we don't go on
801 -- and complain a second time when processing the export list.
803 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
804 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
805 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
808 %*********************************************************
812 %*********************************************************
816 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
817 setInteractiveContext hsc_env icxt thing_inside
819 -- Initialise the tcg_inst_env with instances
820 -- from all home modules. This mimics the more selective
821 -- call to hptInstances in tcRnModule
822 dfuns = hptInstances hsc_env (\mod -> True)
824 updGblEnv (\env -> env {
825 tcg_rdr_env = ic_rn_gbl_env icxt,
826 tcg_type_env = ic_type_env icxt,
827 tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
829 updLclEnv (\env -> env { tcl_rdr = ic_rn_local_env icxt }) $
831 do { traceTc (text "setIC" <+> ppr (ic_type_env icxt))
838 -> InteractiveContext
840 -> IO (Maybe (InteractiveContext, [Name], LHsExpr Id))
841 -- The returned [Name] is the same as the input except for
842 -- ExprStmt, in which case the returned [Name] is [itName]
844 -- The returned TypecheckedHsExpr is of type IO [ () ],
845 -- a list of the bound values, coerced to ().
847 tcRnStmt hsc_env ictxt rdr_stmt
848 = initTcPrintErrors hsc_env iNTERACTIVE $
849 setInteractiveContext hsc_env ictxt $ do {
851 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
852 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
853 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
856 -- The real work is done here
857 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
858 zonked_expr <- zonkTopLExpr tc_expr ;
859 zonked_ids <- zonkTopBndrs bound_ids ;
861 -- None of the Ids should be of unboxed type, because we
862 -- cast them all to HValues in the end!
863 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
865 traceTc (text "tcs 1") ;
866 let { -- (a) Make all the bound ids "global" ids, now that
867 -- they're notionally top-level bindings. This is
868 -- important: otherwise when we come to compile an expression
869 -- using these ids later, the byte code generator will consider
870 -- the occurrences to be free rather than global.
872 -- (b) Tidy their types; this is important, because :info may
873 -- ask to look at them, and :info expects the things it looks
874 -- up to have tidy types
875 global_ids = map globaliseAndTidy zonked_ids ;
877 -- Update the interactive context
878 rn_env = ic_rn_local_env ictxt ;
879 type_env = ic_type_env ictxt ;
881 bound_names = map idName global_ids ;
882 new_rn_env = extendLocalRdrEnv rn_env bound_names ;
884 -- Remove any shadowed bindings from the type_env;
885 -- they are inaccessible but might, I suppose, cause
886 -- a space leak if we leave them there
887 shadowed = [ n | name <- bound_names,
888 let rdr_name = mkRdrUnqual (nameOccName name),
889 Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ;
891 filtered_type_env = delListFromNameEnv type_env shadowed ;
892 new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ;
894 new_ic = ictxt { ic_rn_local_env = new_rn_env,
895 ic_type_env = new_type_env }
898 dumpOptTcRn Opt_D_dump_tc
899 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
900 text "Typechecked expr" <+> ppr zonked_expr]) ;
902 returnM (new_ic, bound_names, zonked_expr)
905 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
906 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
908 globaliseAndTidy :: Id -> Id
910 -- Give the Id a Global Name, and tidy its type
911 = setIdType (globaliseId VanillaGlobal id) tidy_type
913 tidy_type = tidyTopType (idType id)
916 Here is the grand plan, implemented in tcUserStmt
918 What you type The IO [HValue] that hscStmt returns
919 ------------- ------------------------------------
920 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
923 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
926 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
927 [NB: result not printed] bindings: [it]
929 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
930 result showable) bindings: [it]
932 expr (of non-IO type,
933 result not showable) ==> error
937 ---------------------------
938 type PlanResult = ([Id], LHsExpr Id)
939 type Plan = TcM PlanResult
941 runPlans :: [Plan] -> TcM PlanResult
942 -- Try the plans in order. If one fails (by raising an exn), try the next.
943 -- If one succeeds, take it.
944 runPlans [] = panic "runPlans"
946 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
949 mkPlan :: LStmt Name -> TcM PlanResult
950 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
951 = do { uniq <- newUnique -- is treated very specially
952 ; let fresh_it = itName uniq
953 the_bind = L loc $ FunBind (L loc fresh_it) False matches emptyNameSet
954 matches = mkMatchGroup [mkMatch [] expr emptyLocalBinds]
955 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsIn (unitBag the_bind) []))
956 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
957 (HsVar bindIOName) noSyntaxExpr
958 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
959 (HsVar thenIOName) placeHolderType
962 -- [it <- e; print it] but not if it::()
964 -- [let it = e; print it]
965 ; runPlans [ -- Plan A
966 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
967 ; it_ty <- zonkTcType (idType it_id)
968 ; ifM (isUnitTy it_ty) failM
971 -- Plan B; a naked bind statment
972 tcGhciStmts [bind_stmt],
974 -- Plan C; check that the let-binding is typeable all by itself.
975 -- If not, fail; if so, try to print it.
976 -- The two-step process avoids getting two errors: one from
977 -- the expression itself, and one from the 'print it' part
978 -- This two-step story is very clunky, alas
979 do { checkNoErrs (tcGhciStmts [let_stmt])
980 --- checkNoErrs defeats the error recovery of let-bindings
981 ; tcGhciStmts [let_stmt, print_it] }
984 mkPlan stmt@(L loc (BindStmt {}))
985 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
986 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
987 (HsVar thenIOName) placeHolderType
989 -- [stmt; print v] but not if v::()
991 ; runPlans [do { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
992 ; v_ty <- zonkTcType (idType v_id)
993 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
1001 ---------------------------
1002 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1004 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1005 ret_id <- tcLookupId returnIOName ; -- return @ IO
1007 io_ty = mkTyConApp ioTyCon [] ;
1008 ret_ty = mkListTy unitTy ;
1009 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1011 names = map unLoc (collectLStmtsBinders stmts) ;
1013 -- mk_return builds the expression
1014 -- returnIO @ [()] [coerce () x, .., coerce () z]
1016 -- Despite the inconvenience of building the type applications etc,
1017 -- this *has* to be done in type-annotated post-typecheck form
1018 -- because we are going to return a list of *polymorphic* values
1019 -- coerced to type (). If we built a *source* stmt
1020 -- return [coerce x, ..., coerce z]
1021 -- then the type checker would instantiate x..z, and we wouldn't
1022 -- get their *polymorphic* values. (And we'd get ambiguity errs
1023 -- if they were overloaded, since they aren't applied to anything.)
1024 mk_return ids = nlHsApp (noLoc $ TyApp (nlHsVar ret_id) [ret_ty])
1025 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1026 mk_item id = nlHsApp (noLoc $ TyApp (nlHsVar unsafeCoerceId) [idType id, unitTy])
1030 -- OK, we're ready to typecheck the stmts
1031 traceTc (text "tcs 2") ;
1032 ((tc_stmts, ids), lie) <- getLIE $
1033 tcStmts DoExpr (tcDoStmt io_ty io_ret_ty) stmts $
1034 mappM tcLookupId names ;
1035 -- Look up the names right in the middle,
1036 -- where they will all be in scope
1038 -- Simplify the context
1039 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1040 -- checkNoErrs ensures that the plan fails if context redn fails
1042 return (ids, mkHsDictLet const_binds $
1043 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1048 tcRnExpr just finds the type of an expression
1052 -> InteractiveContext
1055 tcRnExpr hsc_env ictxt rdr_expr
1056 = initTcPrintErrors hsc_env iNTERACTIVE $
1057 setInteractiveContext hsc_env ictxt $ do {
1059 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1062 -- Now typecheck the expression;
1063 -- it might have a rank-2 type (e.g. :t runST)
1064 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1065 ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1066 tcSimplifyInteractive lie_top ;
1067 qtvs' <- mappM zonkQuantifiedTyVar qtvs ;
1069 let { all_expr_ty = mkForAllTys qtvs' $
1070 mkFunTys (map idType dict_ids) $
1072 zonkTcType all_expr_ty
1075 smpl_doc = ptext SLIT("main expression")
1078 tcRnType just finds the kind of a type
1082 -> InteractiveContext
1085 tcRnType hsc_env ictxt rdr_type
1086 = initTcPrintErrors hsc_env iNTERACTIVE $
1087 setInteractiveContext hsc_env ictxt $ do {
1089 rn_type <- rnLHsType doc rdr_type ;
1092 -- Now kind-check the type
1093 (ty', kind) <- kcHsType rn_type ;
1097 doc = ptext SLIT("In GHCi input")
1103 %************************************************************************
1105 More GHCi stuff, to do with browsing and getting info
1107 %************************************************************************
1111 -- ASSUMES that the module is either in the HomePackageTable or is
1112 -- a package module with an interface on disk. If neither of these is
1113 -- true, then the result will be an error indicating the interface
1114 -- could not be found.
1115 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe NameSet)
1116 getModuleExports hsc_env mod
1117 = initTc hsc_env HsSrcFile iNTERACTIVE (tcGetModuleExports mod)
1119 tcGetModuleExports :: Module -> TcM NameSet
1120 tcGetModuleExports mod = do
1121 iface <- load_iface mod
1122 loadOrphanModules (dep_orphs (mi_deps iface))
1123 -- Load any orphan-module interfaces,
1124 -- so their instances are visible
1125 ifaceExportNames (mi_exports iface)
1127 load_iface mod = loadSrcInterface doc mod False {- Not boot iface -}
1129 doc = ptext SLIT("context for compiling statements")
1132 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1133 tcRnLookupRdrName hsc_env rdr_name
1134 = initTcPrintErrors hsc_env iNTERACTIVE $
1135 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1136 lookup_rdr_name rdr_name
1138 lookup_rdr_name rdr_name = do {
1139 -- If the identifier is a constructor (begins with an
1140 -- upper-case letter), then we need to consider both
1141 -- constructor and type class identifiers.
1142 let { rdr_names = dataTcOccs rdr_name } ;
1144 -- results :: [Either Messages Name]
1145 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1147 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1148 -- The successful lookups will be (Just name)
1149 let { (warns_s, good_names) = unzip [ (msgs, name)
1150 | (msgs, Just name) <- results] ;
1151 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1153 -- Fail if nothing good happened, else add warnings
1154 if null good_names then
1155 -- No lookup succeeded, so
1156 -- pick the first error message and report it
1157 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1158 -- while the other is "X is not in scope",
1159 -- we definitely want the former; but we might pick the latter
1160 do { addMessages (head errs_s) ; failM }
1161 else -- Add deprecation warnings
1162 mapM_ addMessages warns_s ;
1168 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1169 tcRnLookupName hsc_env name
1170 = initTcPrintErrors hsc_env iNTERACTIVE $
1171 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1175 tcRnGetInfo :: HscEnv
1177 -> IO (Maybe (TyThing, Fixity, [Instance]))
1179 -- Used to implemnent :info in GHCi
1181 -- Look up a RdrName and return all the TyThings it might be
1182 -- A capitalised RdrName is given to us in the DataName namespace,
1183 -- but we want to treat it as *both* a data constructor
1184 -- *and* as a type or class constructor;
1185 -- hence the call to dataTcOccs, and we return up to two results
1186 tcRnGetInfo hsc_env name
1187 = initTcPrintErrors hsc_env iNTERACTIVE $
1188 let ictxt = hsc_IC hsc_env in
1189 setInteractiveContext hsc_env ictxt $ do
1191 -- Load the interface for all unqualified types and classes
1192 -- That way we will find all the instance declarations
1193 -- (Packages have not orphan modules, and we assume that
1194 -- in the home package all relevant modules are loaded.)
1195 loadUnqualIfaces ictxt
1197 thing <- tcLookupGlobal name
1198 fixity <- lookupFixityRn name
1199 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1200 return (thing, fixity, ispecs)
1203 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1204 -- Filter the instances by the ones whose tycons (or clases resp)
1205 -- are in scope unqualified. Otherwise we list a whole lot too many!
1206 lookupInsts print_unqual (AClass cls)
1207 = do { inst_envs <- tcGetInstEnvs
1209 | ispec <- classInstances inst_envs cls
1210 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1212 lookupInsts print_unqual (ATyCon tc)
1213 = do { eps <- getEps -- Load all instances for all classes that are
1214 -- in the type environment (which are all the ones
1215 -- we've seen in any interface file so far)
1216 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1218 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1219 , let dfun = instanceDFunId ispec
1221 , plausibleDFun print_unqual dfun ] }
1223 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1224 tc_name = tyConName tc
1226 lookupInsts print_unqual other = return []
1228 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1229 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1231 ok name | isBuiltInSyntax name = True
1232 | isExternalName name = print_unqual (nameModule name) (nameOccName name)
1235 loadUnqualIfaces :: InteractiveContext -> TcM ()
1236 -- Load the home module for everything that is in scope unqualified
1237 -- This is so that we can accurately report the instances for
1239 loadUnqualIfaces ictxt
1241 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1243 unqual_mods = [ nameModule name
1244 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1245 let name = gre_name gre,
1246 isTcOcc (nameOccName name), -- Types and classes only
1247 unQualOK gre ] -- In scope unqualified
1248 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1252 %************************************************************************
1256 %************************************************************************
1259 rnDump :: SDoc -> TcRn ()
1260 -- Dump, with a banner, if -ddump-rn
1261 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1263 tcDump :: TcGblEnv -> TcRn ()
1265 = do { dflags <- getDOpts ;
1267 -- Dump short output if -ddump-types or -ddump-tc
1268 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1269 (dumpTcRn short_dump) ;
1271 -- Dump bindings if -ddump-tc
1272 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1275 short_dump = pprTcGblEnv env
1276 full_dump = pprLHsBinds (tcg_binds env)
1277 -- NB: foreign x-d's have undefined's in their types;
1278 -- hence can't show the tc_fords
1281 = do { dflags <- getDOpts ;
1282 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1283 (dumpTcRn (pprModGuts mod_guts)) ;
1285 -- Dump bindings if -ddump-tc
1286 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1288 full_dump = pprCoreBindings (mg_binds mod_guts)
1290 -- It's unpleasant having both pprModGuts and pprModDetails here
1291 pprTcGblEnv :: TcGblEnv -> SDoc
1292 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1293 tcg_insts = dfun_ids,
1295 tcg_imports = imports })
1296 = vcat [ ppr_types dfun_ids type_env
1297 , ppr_insts dfun_ids
1298 , vcat (map ppr rules)
1299 , ppr_gen_tycons (typeEnvTyCons type_env)
1300 , ptext SLIT("Dependent modules:") <+> ppr (moduleEnvElts (imp_dep_mods imports))
1301 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1303 pprModGuts :: ModGuts -> SDoc
1304 pprModGuts (ModGuts { mg_types = type_env,
1306 = vcat [ ppr_types [] type_env,
1310 ppr_types :: [Instance] -> TypeEnv -> SDoc
1311 ppr_types ispecs type_env
1312 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1314 dfun_ids = map instanceDFunId ispecs
1315 ids = [id | id <- typeEnvIds type_env, want_sig id]
1316 want_sig id | opt_PprStyle_Debug = True
1317 | otherwise = isLocalId id &&
1318 isExternalName (idName id) &&
1319 not (id `elem` dfun_ids)
1320 -- isLocalId ignores data constructors, records selectors etc.
1321 -- The isExternalName ignores local dictionary and method bindings
1322 -- that the type checker has invented. Top-level user-defined things
1323 -- have External names.
1325 ppr_insts :: [Instance] -> SDoc
1326 ppr_insts [] = empty
1327 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1329 ppr_sigs :: [Var] -> SDoc
1331 -- Print type signatures; sort by OccName
1332 = vcat (map ppr_sig (sortLe le_sig ids))
1334 le_sig id1 id2 = getOccName id1 <= getOccName id2
1335 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1337 ppr_rules :: [CoreRule] -> SDoc
1338 ppr_rules [] = empty
1339 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1340 nest 4 (pprRules rs),
1343 ppr_gen_tycons [] = empty
1344 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1345 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]