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 mkRdrEnvAndImports, mkExportNameSet,
57 reportUnusedNames, reportDeprecations )
58 import RnEnv ( lookupSrcOcc_maybe )
59 import RnSource ( rnSrcDecls, rnTyClDecls, checkModDeprec )
60 import PprCore ( pprRules, pprCoreBindings )
61 import CoreSyn ( CoreRule, bindersOfBinds )
62 import DataCon ( dataConWrapId )
63 import ErrUtils ( Messages, mkDumpDoc, showPass )
64 import Id ( Id, mkExportedLocalId, isLocalId, idName, idType )
66 import Module ( Module, ModuleEnv, moduleEnvElts, elemModuleEnv )
67 import OccName ( mkVarOccFS )
68 import Name ( Name, NamedThing(..), isExternalName, getSrcLoc, isWiredInName,
71 import TyCon ( tyConHasGenerics, isSynTyCon, synTyConDefn, tyConKind )
72 import SrcLoc ( srcLocSpan, Located(..), noLoc )
73 import DriverPhases ( HscSource(..), isHsBoot )
74 import HscTypes ( ModGuts(..), ModDetails(..), emptyModDetails,
75 HscEnv(..), ExternalPackageState(..),
76 IsBootInterface, noDependencies,
77 Deprecs( NoDeprecs ), plusDeprecs,
78 ForeignStubs(NoStubs), TyThing(..),
79 TypeEnv, lookupTypeEnv, hptInstances,
80 extendTypeEnvWithIds, typeEnvIds, typeEnvTyCons, typeEnvElts,
86 import HsSyn ( HsStmtContext(..), Stmt(..), HsExpr(..),
87 HsLocalBinds(..), HsValBinds(..),
88 LStmt, LHsExpr, LHsType, mkMatch, emptyLocalBinds,
89 collectLStmtsBinders, collectLStmtBinders, nlVarPat,
90 mkFunBind, placeHolderType, noSyntaxExpr )
91 import RdrName ( GlobalRdrElt(..), globalRdrEnvElts,
92 unQualOK, lookupLocalRdrEnv, extendLocalRdrEnv )
93 import RnSource ( addTcgDUs )
94 import TcHsSyn ( mkHsDictLet, zonkTopLExpr, zonkTopBndrs )
95 import TcHsType ( kcHsType )
96 import TcMType ( zonkTcType, zonkQuantifiedTyVar )
97 import TcMatches ( tcStmts, tcDoStmt )
98 import TcSimplify ( tcSimplifyInteractive, tcSimplifyInfer )
99 import TcType ( Type, mkForAllTys, mkFunTys, mkTyConApp, tyVarsOfType, isTauTy,
100 isUnLiftedType, tyClsNamesOfDFunHead, tyClsNamesOfType, isUnitTy )
101 import TcEnv ( tcLookupTyCon, tcLookupId, tcLookupGlobal )
102 import RnTypes ( rnLHsType )
103 import Inst ( tcGetInstEnvs )
104 import InstEnv ( classInstances, instEnvElts )
105 import RnExpr ( rnStmts, rnLExpr )
106 import LoadIface ( loadSrcInterface, loadSysInterface )
107 import IfaceEnv ( ifaceExportNames )
108 import Module ( moduleSetElts, mkModuleSet )
109 import RnEnv ( lookupOccRn, dataTcOccs, lookupFixityRn )
110 import Id ( setIdType )
111 import MkId ( unsafeCoerceId )
112 import TyCon ( tyConName )
113 import TysWiredIn ( mkListTy, unitTy )
114 import IdInfo ( GlobalIdDetails(..) )
116 import Var ( globaliseId )
117 import Name ( nameOccName, nameModule, isBuiltInSyntax )
118 import OccName ( isTcOcc )
119 import NameEnv ( delListFromNameEnv )
120 import PrelNames ( iNTERACTIVE, ioTyConName, printName, itName,
121 bindIOName, thenIOName, returnIOName )
122 import HscTypes ( InteractiveContext(..),
123 ModIface(..), icPrintUnqual,
125 import BasicTypes ( Fixity, RecFlag(..) )
126 import SrcLoc ( unLoc )
129 import FastString ( mkFastString )
130 import Maybes ( MaybeErr(..) )
131 import Util ( sortLe )
132 import Bag ( unionBags, snocBag, emptyBag, unitBag, unionManyBags )
134 import Maybe ( isJust )
139 %************************************************************************
141 Typecheck and rename a module
143 %************************************************************************
149 -> Bool -- True <=> save renamed syntax
150 -> Located (HsModule RdrName)
151 -> IO (Messages, Maybe TcGblEnv)
153 tcRnModule hsc_env hsc_src save_rn_syntax
154 (L loc (HsModule maybe_mod export_ies
155 import_decls local_decls mod_deprec))
156 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
158 let { this_mod = case maybe_mod of
159 Nothing -> mAIN -- 'module M where' is omitted
160 Just (L _ mod) -> mod } ; -- The normal case
162 initTc hsc_env hsc_src this_mod $
165 -- Deal with imports;
166 rn_imports <- rnImports import_decls ;
167 (rdr_env, imports) <- mkRdrEnvAndImports rn_imports ;
169 let { dep_mods :: ModuleEnv (Module, IsBootInterface)
170 ; dep_mods = imp_dep_mods imports
172 -- We want instance declarations from all home-package
173 -- modules below this one, including boot modules, except
174 -- ourselves. The 'except ourselves' is so that we don't
175 -- get the instances from this module's hs-boot file
176 ; want_instances :: Module -> Bool
177 ; want_instances mod = mod `elemModuleEnv` dep_mods
179 ; home_insts = hptInstances hsc_env want_instances
182 -- Record boot-file info in the EPS, so that it's
183 -- visible to loadHiBootInterface in tcRnSrcDecls,
184 -- and any other incrementally-performed imports
185 updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
187 checkConflicts imports this_mod $ do {
189 -- Update the gbl env
191 gbl { tcg_rdr_env = rdr_env,
192 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
193 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
194 tcg_rn_imports = if save_rn_syntax then
198 tcg_rn_decls = if save_rn_syntax then
204 traceRn (text "rn1" <+> ppr (imp_dep_mods imports)) ;
205 -- Fail if there are any errors so far
206 -- The error printing (if needed) takes advantage
207 -- of the tcg_env we have now set
210 -- Load any orphan-module interfaces, so that
211 -- their rules and instance decls will be found
212 loadOrphanModules (imp_orphs imports) ;
214 traceRn (text "rn1a") ;
215 -- Rename and type check the declarations
216 tcg_env <- if isHsBoot hsc_src then
217 tcRnHsBootDecls local_decls
219 tcRnSrcDecls local_decls ;
220 setGblEnv tcg_env $ do {
222 traceRn (text "rn3") ;
224 -- Report the use of any deprecated things
225 -- We do this before processsing the export list so
226 -- that we don't bleat about re-exporting a deprecated
227 -- thing (especially via 'module Foo' export item)
228 -- Only uses in the body of the module are complained about
229 reportDeprecations tcg_env ;
231 -- Process the export list
232 rn_exports <- rnExports export_ies ;
233 exports <- mkExportNameSet (isJust maybe_mod) rn_exports ;
235 -- Check whether the entire module is deprecated
236 -- This happens only once per module
237 let { mod_deprecs = checkModDeprec mod_deprec } ;
239 -- Add exports and deprecations to envt
240 let { final_env = tcg_env { tcg_exports = exports,
241 tcg_rn_exports = if save_rn_syntax then
244 tcg_dus = tcg_dus tcg_env `plusDU` usesOnly exports,
245 tcg_deprecs = tcg_deprecs tcg_env `plusDeprecs`
247 -- A module deprecation over-rides the earlier ones
250 -- Report unused names
251 reportUnusedNames export_ies final_env ;
253 -- Dump output and return
259 -- The program is not allowed to contain two modules with the same
260 -- name, and we check for that here. It could happen if the home package
261 -- contains a module that is also present in an external package, for example.
262 checkConflicts imports this_mod and_then = do
265 dep_mods = this_mod : map fst (moduleEnvElts (imp_dep_mods imports))
266 -- don't forget to include the current module!
268 mb_dep_pkgs = checkForPackageConflicts
269 dflags dep_mods (imp_dep_pkgs imports)
275 updGblEnv (\gbl -> gbl{ tcg_home_mods = mkHomeModules dep_mods })
280 %************************************************************************
282 Type-checking external-core modules
284 %************************************************************************
287 tcRnExtCore :: HscEnv
289 -> IO (Messages, Maybe ModGuts)
290 -- Nothing => some error occurred
292 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
293 -- The decls are IfaceDecls; all names are original names
294 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
296 initTc hsc_env ExtCoreFile this_mod $ do {
298 let { ldecls = map noLoc decls } ;
300 -- Deal with the type declarations; first bring their stuff
301 -- into scope, then rname them, then type check them
302 tcg_env <- importsFromLocalDecls (mkFakeGroup ldecls) ;
304 setGblEnv tcg_env $ do {
306 rn_decls <- rnTyClDecls ldecls ;
309 -- Dump trace of renaming part
310 rnDump (ppr rn_decls) ;
312 -- Typecheck them all together so that
313 -- any mutually recursive types are done right
314 tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails rn_decls) ;
315 -- Make the new type env available to stuff slurped from interface files
317 setGblEnv tcg_env $ do {
319 -- Now the core bindings
320 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
324 bndrs = bindersOfBinds core_binds ;
325 my_exports = mkNameSet (map idName bndrs) ;
326 -- ToDo: export the data types also?
328 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
330 mod_guts = ModGuts { mg_module = this_mod,
332 mg_usages = [], -- ToDo: compute usage
333 mg_dir_imps = [], -- ??
334 mg_deps = noDependencies, -- ??
335 mg_home_mods = mkHomeModules [], -- ?? wrong!!
336 mg_exports = my_exports,
337 mg_types = final_type_env,
338 mg_insts = tcg_insts tcg_env,
340 mg_binds = core_binds,
343 mg_rdr_env = emptyGlobalRdrEnv,
344 mg_fix_env = emptyFixityEnv,
345 mg_deprecs = NoDeprecs,
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 :: [LHsDecl RdrName] -> TcM TcGblEnv
367 -- Returns the variables free in the decls
368 -- Reason: solely to report unused imports and bindings
370 = do { -- Load the hi-boot interface for this module, if any
371 -- We do this now so that the boot_names can be passed
372 -- to tcTyAndClassDecls, because the boot_names are
373 -- automatically considered to be loop breakers
375 boot_iface <- tcHiBootIface mod ;
377 -- Do all the declarations
378 (tc_envs, lie) <- getLIE (tc_rn_src_decls boot_iface decls) ;
380 -- tcSimplifyTop deals with constant or ambiguous InstIds.
381 -- How could there be ambiguous ones? They can only arise if a
382 -- top-level decl falls under the monomorphism
383 -- restriction, and no subsequent decl instantiates its
384 -- type. (Usually, ambiguous type variables are resolved
385 -- during the generalisation step.)
386 traceTc (text "Tc8") ;
387 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
388 -- Setting the global env exposes the instances to tcSimplifyTop
389 -- Setting the local env exposes the local Ids to tcSimplifyTop,
390 -- so that we get better error messages (monomorphism restriction)
392 -- Backsubstitution. This must be done last.
393 -- Even tcSimplifyTop may do some unification.
394 traceTc (text "Tc9") ;
395 let { (tcg_env, _) = tc_envs ;
396 TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
397 tcg_rules = rules, tcg_fords = fords } = tcg_env } ;
400 (bind_ids, binds', fords', rules') <- zonkTopDecls (binds `unionBags` inst_binds)
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 -- Make the new type env available to stuff slurped from interface files
410 writeMutVar (tcg_type_env_var tcg_env) final_type_env ;
412 -- Compare the hi-boot iface (if any) with the real thing
413 dfun_binds <- checkHiBootIface tcg_env' boot_iface ;
415 return (tcg_env' { tcg_binds = tcg_binds tcg_env' `unionBags` dfun_binds })
418 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
419 -- Loops around dealing with each top level inter-splice group
420 -- in turn, until it's dealt with the entire module
421 tc_rn_src_decls boot_details ds
422 = do { let { (first_group, group_tail) = findSplice ds } ;
423 -- If ds is [] we get ([], Nothing)
425 -- Type check the decls up to, but not including, the first splice
426 tc_envs@(tcg_env,tcl_env) <- tcRnGroup boot_details first_group ;
428 -- Bale out if errors; for example, error recovery when checking
429 -- the RHS of 'main' can mean that 'main' is not in the envt for
430 -- the subsequent checkMain test
435 -- If there is no splice, we're nearly done
437 Nothing -> do { -- Last thing: check for `main'
438 tcg_env <- checkMain ;
439 return (tcg_env, tcl_env)
442 -- If there's a splice, we must carry on
443 Just (SpliceDecl splice_expr, rest_ds) -> do {
445 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
448 -- Rename the splice expression, and get its supporting decls
449 (rn_splice_expr, splice_fvs) <- rnLExpr splice_expr ;
450 failIfErrsM ; -- Don't typecheck if renaming failed
452 -- Execute the splice
453 spliced_decls <- tcSpliceDecls rn_splice_expr ;
455 -- Glue them on the front of the remaining decls and loop
456 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
457 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
462 %************************************************************************
464 Compiling hs-boot source files, and
465 comparing the hi-boot interface with the real thing
467 %************************************************************************
470 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
471 tcRnHsBootDecls decls
472 = do { let { (first_group, group_tail) = findSplice decls }
475 Just stuff -> spliceInHsBootErr stuff
478 -- Rename the declarations
479 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
480 ; setGblEnv tcg_env $ do {
482 -- Todo: check no foreign decls, no rules, no default decls
484 -- Typecheck type/class decls
485 ; traceTc (text "Tc2")
486 ; let tycl_decls = hs_tyclds rn_group
487 ; tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails tycl_decls)
488 ; setGblEnv tcg_env $ do {
490 -- Typecheck instance decls
491 ; traceTc (text "Tc3")
492 ; (tcg_env, inst_infos, _binds) <- tcInstDecls1 tycl_decls (hs_instds rn_group)
493 ; setGblEnv tcg_env $ do {
495 -- Typecheck value declarations
496 ; traceTc (text "Tc5")
497 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
500 -- No simplification or zonking to do
501 ; traceTc (text "Tc7a")
502 ; gbl_env <- getGblEnv
504 -- Make the final type-env
505 -- Include the dfun_ids so that their type sigs get
506 -- are written into the interface file
507 ; let { type_env0 = tcg_type_env gbl_env
508 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
509 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
510 ; dfun_ids = map iDFunId inst_infos }
511 ; return (gbl_env { tcg_type_env = type_env2 })
514 spliceInHsBootErr (SpliceDecl (L loc _), _)
515 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
518 Once we've typechecked the body of the module, we want to compare what
519 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
522 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM (LHsBinds Id)
523 -- Compare the hi-boot file for this module (if there is one)
524 -- with the type environment we've just come up with
525 -- In the common case where there is no hi-boot file, the list
526 -- of boot_names is empty.
528 -- The bindings we return give bindings for the dfuns defined in the
529 -- hs-boot file, such as $fbEqT = $fEqT
532 (TcGblEnv { tcg_insts = local_insts, tcg_type_env = local_type_env })
533 (ModDetails { md_insts = boot_insts, md_types = boot_type_env })
534 = do { mapM_ check_one (typeEnvElts boot_type_env)
535 ; dfun_binds <- mapM check_inst boot_insts
536 ; return (unionManyBags dfun_binds) }
542 = case lookupTypeEnv local_type_env name of
543 Nothing -> addErrTc (missingBootThing boot_thing)
544 Just real_thing -> check_thing boot_thing real_thing
546 name = getName boot_thing
548 no_check name = isWiredInName name -- No checking for wired-in names. In particular,
549 -- 'error' is handled by a rather gross hack
550 -- (see comments in GHC.Err.hs-boot)
551 || name `elem` dfun_names
552 dfun_names = map getName boot_insts
555 = case [dfun | inst <- local_insts,
556 let dfun = instanceDFunId inst,
557 idType dfun `tcEqType` boot_inst_ty ] of
558 [] -> do { addErrTc (instMisMatch boot_inst); return emptyBag }
559 (dfun:_) -> return (unitBag $ noLoc $ VarBind local_boot_dfun (nlHsVar dfun))
561 boot_dfun = instanceDFunId boot_inst
562 boot_inst_ty = idType boot_dfun
563 local_boot_dfun = mkExportedLocalId (idName boot_dfun) boot_inst_ty
566 check_thing (ATyCon boot_tc) (ATyCon real_tc)
567 | isSynTyCon boot_tc && isSynTyCon real_tc,
568 defn1 `tcEqType` substTyWith tvs2 (mkTyVarTys tvs1) defn2
571 | tyConKind boot_tc == tyConKind real_tc
574 (tvs1, defn1) = synTyConDefn boot_tc
575 (tvs2, defn2) = synTyConDefn boot_tc
577 check_thing (AnId boot_id) (AnId real_id)
578 | idType boot_id `tcEqType` idType real_id
581 check_thing (ADataCon dc1) (ADataCon dc2)
582 | idType (dataConWrapId dc1) `tcEqType` idType (dataConWrapId dc2)
585 -- Can't declare a class in a hi-boot file
587 check_thing boot_thing real_thing -- Default case; failure
588 = addErrAt (srcLocSpan (getSrcLoc real_thing))
589 (bootMisMatch real_thing)
592 missingBootThing thing
593 = ppr thing <+> ptext SLIT("is defined in the hs-boot file, but not in the module")
595 = ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file")
598 2 (ptext SLIT("is defined in the hs-boot file, but not in the module"))
602 %************************************************************************
604 Type-checking the top level of a module
606 %************************************************************************
608 tcRnGroup takes a bunch of top-level source-code declarations, and
610 * gets supporting declarations from interface files
613 * and augments the TcGblEnv with the results
615 In Template Haskell it may be called repeatedly for each group of
616 declarations. It expects there to be an incoming TcGblEnv in the
617 monad; it augments it and returns the new TcGblEnv.
620 tcRnGroup :: ModDetails -> HsGroup RdrName -> TcM (TcGblEnv, TcLclEnv)
621 -- Returns the variables free in the decls, for unused-binding reporting
622 tcRnGroup boot_details decls
623 = do { -- Rename the declarations
624 (tcg_env, rn_decls) <- rnTopSrcDecls decls ;
625 setGblEnv tcg_env $ do {
627 -- Typecheck the declarations
628 tcTopSrcDecls boot_details rn_decls
631 ------------------------------------------------
632 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
634 = do { -- Bring top level binders into scope
635 tcg_env <- importsFromLocalDecls group ;
636 setGblEnv tcg_env $ do {
638 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
640 -- Rename the source decls
641 (tcg_env, rn_decls) <- rnSrcDecls group ;
644 -- save the renamed syntax, if we want it
646 | Just grp <- tcg_rn_decls tcg_env
647 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
651 -- Dump trace of renaming part
652 rnDump (ppr rn_decls) ;
654 return (tcg_env', rn_decls)
657 ------------------------------------------------
658 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
659 tcTopSrcDecls boot_details
660 (HsGroup { hs_tyclds = tycl_decls,
661 hs_instds = inst_decls,
662 hs_fords = foreign_decls,
663 hs_defds = default_decls,
664 hs_ruleds = rule_decls,
665 hs_valds = val_binds })
666 = do { -- Type-check the type and class decls, and all imported decls
667 -- The latter come in via tycl_decls
668 traceTc (text "Tc2") ;
670 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
671 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
672 -- an error we'd better stop now, to avoid a cascade
674 -- Make these type and class decls available to stuff slurped from interface files
675 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
678 setGblEnv tcg_env $ do {
679 -- Source-language instances, including derivings,
680 -- and import the supporting declarations
681 traceTc (text "Tc3") ;
682 (tcg_env, inst_infos, deriv_binds) <- tcInstDecls1 tycl_decls inst_decls ;
683 setGblEnv tcg_env $ do {
685 -- Foreign import declarations next. No zonking necessary
686 -- here; we can tuck them straight into the global environment.
687 traceTc (text "Tc4") ;
688 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
689 tcExtendGlobalValEnv fi_ids $ do {
691 -- Default declarations
692 traceTc (text "Tc4a") ;
693 default_tys <- tcDefaults default_decls ;
694 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
696 -- Value declarations next
697 -- We also typecheck any extra binds that came out
698 -- of the "deriving" process (deriv_binds)
699 traceTc (text "Tc5") ;
700 (tc_val_binds, tcl_env) <- tcTopBinds (val_binds `plusHsValBinds` deriv_binds) ;
701 setLclTypeEnv tcl_env $ do {
703 -- Second pass over class and instance declarations,
704 traceTc (text "Tc6") ;
705 (inst_binds, tcl_env) <- tcInstDecls2 tycl_decls inst_infos ;
706 showLIE (text "after instDecls2") ;
709 -- They need to be zonked, so we return them
710 traceTc (text "Tc7") ;
711 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
714 rules <- tcRules rule_decls ;
717 traceTc (text "Tc7a") ;
718 tcg_env <- getGblEnv ;
719 let { all_binds = tc_val_binds `unionBags`
720 inst_binds `unionBags`
723 -- Extend the GblEnv with the (as yet un-zonked)
724 -- bindings, rules, foreign decls
725 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
726 tcg_rules = tcg_rules tcg_env ++ rules,
727 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
728 return (tcg_env', tcl_env)
733 %************************************************************************
737 %************************************************************************
740 checkMain :: TcM TcGblEnv
741 -- If we are in module Main, check that 'main' is defined.
743 = do { ghci_mode <- getGhciMode ;
744 tcg_env <- getGblEnv ;
746 let { main_mod = mainModIs dflags ;
747 main_fn = case mainFunIs dflags of {
748 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn)) ;
749 Nothing -> main_RDR_Unqual } } ;
751 check_main ghci_mode tcg_env main_mod main_fn
755 check_main ghci_mode tcg_env main_mod main_fn
757 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
761 = addErrCtxt mainCtxt $
762 do { mb_main <- lookupSrcOcc_maybe main_fn
763 -- Check that 'main' is in scope
764 -- It might be imported from another module!
766 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
770 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
771 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
772 -- :Main.main :: IO () = runMainIO main
774 ; (main_expr, ty) <- setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
777 -- The function that the RTS invokes is always :Main.main,
778 -- which we call root_main_id.
779 -- (Because GHC allows the user to have a module not called
780 -- Main as the main module, we can't rely on the main function
781 -- being called "Main.main". That's why root_main_id has a fixed
783 -- We also make root_main_id an implicit Id, by making main_name
784 -- its parent (hence (Just main_name)). That has the effect
785 -- of preventing its type and unfolding from getting out into
786 -- the interface file. Otherwise we can end up with two defns
787 -- for 'main' in the interface file!
789 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
790 (mkVarOccFS FSLIT("main"))
791 (Just main_name) (getSrcLoc main_name)
792 ; root_main_id = mkExportedLocalId root_main_name ty
793 ; main_bind = noLoc (VarBind root_main_id main_expr) }
795 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
797 tcg_dus = tcg_dus tcg_env
798 `plusDU` usesOnly (unitFV main_name)
799 -- Record the use of 'main', so that we don't
800 -- complain about it being defined but not used
804 mod = tcg_mod tcg_env
806 complain_no_main | ghci_mode == Interactive = return ()
807 | otherwise = failWithTc noMainMsg
808 -- In interactive mode, don't worry about the absence of 'main'
809 -- In other modes, fail altogether, so that we don't go on
810 -- and complain a second time when processing the export list.
812 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
813 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
814 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
817 %*********************************************************
821 %*********************************************************
825 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
826 setInteractiveContext hsc_env icxt thing_inside
828 -- Initialise the tcg_inst_env with instances
829 -- from all home modules. This mimics the more selective
830 -- call to hptInstances in tcRnModule
831 dfuns = hptInstances hsc_env (\mod -> True)
833 updGblEnv (\env -> env {
834 tcg_rdr_env = ic_rn_gbl_env icxt,
835 tcg_type_env = ic_type_env icxt,
836 tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
838 updLclEnv (\env -> env { tcl_rdr = ic_rn_local_env icxt }) $
840 do { traceTc (text "setIC" <+> ppr (ic_type_env icxt))
847 -> InteractiveContext
849 -> IO (Maybe (InteractiveContext, [Name], LHsExpr Id))
850 -- The returned [Name] is the same as the input except for
851 -- ExprStmt, in which case the returned [Name] is [itName]
853 -- The returned TypecheckedHsExpr is of type IO [ () ],
854 -- a list of the bound values, coerced to ().
856 tcRnStmt hsc_env ictxt rdr_stmt
857 = initTcPrintErrors hsc_env iNTERACTIVE $
858 setInteractiveContext hsc_env ictxt $ do {
860 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
861 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
862 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
865 -- The real work is done here
866 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
867 zonked_expr <- zonkTopLExpr tc_expr ;
868 zonked_ids <- zonkTopBndrs bound_ids ;
870 -- None of the Ids should be of unboxed type, because we
871 -- cast them all to HValues in the end!
872 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
874 traceTc (text "tcs 1") ;
875 let { -- (a) Make all the bound ids "global" ids, now that
876 -- they're notionally top-level bindings. This is
877 -- important: otherwise when we come to compile an expression
878 -- using these ids later, the byte code generator will consider
879 -- the occurrences to be free rather than global.
881 -- (b) Tidy their types; this is important, because :info may
882 -- ask to look at them, and :info expects the things it looks
883 -- up to have tidy types
884 global_ids = map globaliseAndTidy zonked_ids ;
886 -- Update the interactive context
887 rn_env = ic_rn_local_env ictxt ;
888 type_env = ic_type_env ictxt ;
890 bound_names = map idName global_ids ;
891 new_rn_env = extendLocalRdrEnv rn_env bound_names ;
893 -- Remove any shadowed bindings from the type_env;
894 -- they are inaccessible but might, I suppose, cause
895 -- a space leak if we leave them there
896 shadowed = [ n | name <- bound_names,
897 let rdr_name = mkRdrUnqual (nameOccName name),
898 Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ;
900 filtered_type_env = delListFromNameEnv type_env shadowed ;
901 new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ;
903 new_ic = ictxt { ic_rn_local_env = new_rn_env,
904 ic_type_env = new_type_env }
907 dumpOptTcRn Opt_D_dump_tc
908 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
909 text "Typechecked expr" <+> ppr zonked_expr]) ;
911 returnM (new_ic, bound_names, zonked_expr)
914 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
915 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
917 globaliseAndTidy :: Id -> Id
919 -- Give the Id a Global Name, and tidy its type
920 = setIdType (globaliseId VanillaGlobal id) tidy_type
922 tidy_type = tidyTopType (idType id)
925 Here is the grand plan, implemented in tcUserStmt
927 What you type The IO [HValue] that hscStmt returns
928 ------------- ------------------------------------
929 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
932 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
935 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
936 [NB: result not printed] bindings: [it]
938 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
939 result showable) bindings: [it]
941 expr (of non-IO type,
942 result not showable) ==> error
946 ---------------------------
947 type PlanResult = ([Id], LHsExpr Id)
948 type Plan = TcM PlanResult
950 runPlans :: [Plan] -> TcM PlanResult
951 -- Try the plans in order. If one fails (by raising an exn), try the next.
952 -- If one succeeds, take it.
953 runPlans [] = panic "runPlans"
955 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
958 mkPlan :: LStmt Name -> TcM PlanResult
959 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
960 = do { uniq <- newUnique -- is treated very specially
961 ; let fresh_it = itName uniq
962 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
963 matches = [mkMatch [] expr emptyLocalBinds]
964 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
965 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
966 (HsVar bindIOName) noSyntaxExpr
967 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
968 (HsVar thenIOName) placeHolderType
971 -- [it <- e; print it] but not if it::()
973 -- [let it = e; print it]
974 ; runPlans [ -- Plan A
975 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
976 ; it_ty <- zonkTcType (idType it_id)
977 ; ifM (isUnitTy it_ty) failM
980 -- Plan B; a naked bind statment
981 tcGhciStmts [bind_stmt],
983 -- Plan C; check that the let-binding is typeable all by itself.
984 -- If not, fail; if so, try to print it.
985 -- The two-step process avoids getting two errors: one from
986 -- the expression itself, and one from the 'print it' part
987 -- This two-step story is very clunky, alas
988 do { checkNoErrs (tcGhciStmts [let_stmt])
989 --- checkNoErrs defeats the error recovery of let-bindings
990 ; tcGhciStmts [let_stmt, print_it] }
993 mkPlan stmt@(L loc (BindStmt {}))
994 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
995 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
996 (HsVar thenIOName) placeHolderType
998 -- [stmt; print v] but not if v::()
1000 ; runPlans [do { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1001 ; v_ty <- zonkTcType (idType v_id)
1002 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
1008 = tcGhciStmts [stmt]
1010 ---------------------------
1011 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1013 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1014 ret_id <- tcLookupId returnIOName ; -- return @ IO
1016 io_ty = mkTyConApp ioTyCon [] ;
1017 ret_ty = mkListTy unitTy ;
1018 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1020 names = map unLoc (collectLStmtsBinders stmts) ;
1022 -- mk_return builds the expression
1023 -- returnIO @ [()] [coerce () x, .., coerce () z]
1025 -- Despite the inconvenience of building the type applications etc,
1026 -- this *has* to be done in type-annotated post-typecheck form
1027 -- because we are going to return a list of *polymorphic* values
1028 -- coerced to type (). If we built a *source* stmt
1029 -- return [coerce x, ..., coerce z]
1030 -- then the type checker would instantiate x..z, and we wouldn't
1031 -- get their *polymorphic* values. (And we'd get ambiguity errs
1032 -- if they were overloaded, since they aren't applied to anything.)
1033 mk_return ids = nlHsApp (noLoc $ TyApp (nlHsVar ret_id) [ret_ty])
1034 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1035 mk_item id = nlHsApp (noLoc $ TyApp (nlHsVar unsafeCoerceId) [idType id, unitTy])
1039 -- OK, we're ready to typecheck the stmts
1040 traceTc (text "tcs 2") ;
1041 ((tc_stmts, ids), lie) <- getLIE $
1042 tcStmts DoExpr (tcDoStmt io_ty) stmts io_ret_ty $ \ _ ->
1043 mappM tcLookupId names ;
1044 -- Look up the names right in the middle,
1045 -- where they will all be in scope
1047 -- Simplify the context
1048 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1049 -- checkNoErrs ensures that the plan fails if context redn fails
1051 return (ids, mkHsDictLet const_binds $
1052 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1057 tcRnExpr just finds the type of an expression
1061 -> InteractiveContext
1064 tcRnExpr hsc_env ictxt rdr_expr
1065 = initTcPrintErrors hsc_env iNTERACTIVE $
1066 setInteractiveContext hsc_env ictxt $ do {
1068 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1071 -- Now typecheck the expression;
1072 -- it might have a rank-2 type (e.g. :t runST)
1073 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1074 ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1075 tcSimplifyInteractive lie_top ;
1076 qtvs' <- mappM zonkQuantifiedTyVar qtvs ;
1078 let { all_expr_ty = mkForAllTys qtvs' $
1079 mkFunTys (map idType dict_ids) $
1081 zonkTcType all_expr_ty
1084 smpl_doc = ptext SLIT("main expression")
1087 tcRnType just finds the kind of a type
1091 -> InteractiveContext
1094 tcRnType hsc_env ictxt rdr_type
1095 = initTcPrintErrors hsc_env iNTERACTIVE $
1096 setInteractiveContext hsc_env ictxt $ do {
1098 rn_type <- rnLHsType doc rdr_type ;
1101 -- Now kind-check the type
1102 (ty', kind) <- kcHsType rn_type ;
1106 doc = ptext SLIT("In GHCi input")
1112 %************************************************************************
1114 More GHCi stuff, to do with browsing and getting info
1116 %************************************************************************
1120 -- ASSUMES that the module is either in the HomePackageTable or is
1121 -- a package module with an interface on disk. If neither of these is
1122 -- true, then the result will be an error indicating the interface
1123 -- could not be found.
1124 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe NameSet)
1125 getModuleExports hsc_env mod
1126 = initTc hsc_env HsSrcFile iNTERACTIVE (tcGetModuleExports mod)
1128 tcGetModuleExports :: Module -> TcM NameSet
1129 tcGetModuleExports mod = do
1130 iface <- load_iface mod
1131 loadOrphanModules (dep_orphs (mi_deps iface))
1132 -- Load any orphan-module interfaces,
1133 -- so their instances are visible
1134 ifaceExportNames (mi_exports iface)
1136 load_iface mod = loadSrcInterface doc mod False {- Not boot iface -}
1138 doc = ptext SLIT("context for compiling statements")
1141 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1142 tcRnLookupRdrName hsc_env rdr_name
1143 = initTcPrintErrors hsc_env iNTERACTIVE $
1144 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1145 lookup_rdr_name rdr_name
1147 lookup_rdr_name rdr_name = do {
1148 -- If the identifier is a constructor (begins with an
1149 -- upper-case letter), then we need to consider both
1150 -- constructor and type class identifiers.
1151 let { rdr_names = dataTcOccs rdr_name } ;
1153 -- results :: [Either Messages Name]
1154 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1156 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1157 -- The successful lookups will be (Just name)
1158 let { (warns_s, good_names) = unzip [ (msgs, name)
1159 | (msgs, Just name) <- results] ;
1160 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1162 -- Fail if nothing good happened, else add warnings
1163 if null good_names then
1164 -- No lookup succeeded, so
1165 -- pick the first error message and report it
1166 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1167 -- while the other is "X is not in scope",
1168 -- we definitely want the former; but we might pick the latter
1169 do { addMessages (head errs_s) ; failM }
1170 else -- Add deprecation warnings
1171 mapM_ addMessages warns_s ;
1177 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1178 tcRnLookupName hsc_env name
1179 = initTcPrintErrors hsc_env iNTERACTIVE $
1180 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1184 tcRnGetInfo :: HscEnv
1186 -> IO (Maybe (TyThing, Fixity, [Instance]))
1188 -- Used to implemnent :info in GHCi
1190 -- Look up a RdrName and return all the TyThings it might be
1191 -- A capitalised RdrName is given to us in the DataName namespace,
1192 -- but we want to treat it as *both* a data constructor
1193 -- *and* as a type or class constructor;
1194 -- hence the call to dataTcOccs, and we return up to two results
1195 tcRnGetInfo hsc_env name
1196 = initTcPrintErrors hsc_env iNTERACTIVE $
1197 let ictxt = hsc_IC hsc_env in
1198 setInteractiveContext hsc_env ictxt $ do
1200 -- Load the interface for all unqualified types and classes
1201 -- That way we will find all the instance declarations
1202 -- (Packages have not orphan modules, and we assume that
1203 -- in the home package all relevant modules are loaded.)
1204 loadUnqualIfaces ictxt
1206 thing <- tcLookupGlobal name
1207 fixity <- lookupFixityRn name
1208 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1209 return (thing, fixity, ispecs)
1212 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1213 -- Filter the instances by the ones whose tycons (or clases resp)
1214 -- are in scope unqualified. Otherwise we list a whole lot too many!
1215 lookupInsts print_unqual (AClass cls)
1216 = do { inst_envs <- tcGetInstEnvs
1218 | ispec <- classInstances inst_envs cls
1219 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1221 lookupInsts print_unqual (ATyCon tc)
1222 = do { eps <- getEps -- Load all instances for all classes that are
1223 -- in the type environment (which are all the ones
1224 -- we've seen in any interface file so far)
1225 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1227 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1228 , let dfun = instanceDFunId ispec
1230 , plausibleDFun print_unqual dfun ] }
1232 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1233 tc_name = tyConName tc
1235 lookupInsts print_unqual other = return []
1237 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1238 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1240 ok name | isBuiltInSyntax name = True
1241 | isExternalName name = print_unqual (nameModule name) (nameOccName name)
1244 loadUnqualIfaces :: InteractiveContext -> TcM ()
1245 -- Load the home module for everything that is in scope unqualified
1246 -- This is so that we can accurately report the instances for
1248 loadUnqualIfaces ictxt
1250 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1252 unqual_mods = [ nameModule name
1253 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1254 let name = gre_name gre,
1255 isTcOcc (nameOccName name), -- Types and classes only
1256 unQualOK gre ] -- In scope unqualified
1257 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1261 %************************************************************************
1265 %************************************************************************
1268 rnDump :: SDoc -> TcRn ()
1269 -- Dump, with a banner, if -ddump-rn
1270 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1272 tcDump :: TcGblEnv -> TcRn ()
1274 = do { dflags <- getDOpts ;
1276 -- Dump short output if -ddump-types or -ddump-tc
1277 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1278 (dumpTcRn short_dump) ;
1280 -- Dump bindings if -ddump-tc
1281 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1284 short_dump = pprTcGblEnv env
1285 full_dump = pprLHsBinds (tcg_binds env)
1286 -- NB: foreign x-d's have undefined's in their types;
1287 -- hence can't show the tc_fords
1290 = do { dflags <- getDOpts ;
1291 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1292 (dumpTcRn (pprModGuts mod_guts)) ;
1294 -- Dump bindings if -ddump-tc
1295 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1297 full_dump = pprCoreBindings (mg_binds mod_guts)
1299 -- It's unpleasant having both pprModGuts and pprModDetails here
1300 pprTcGblEnv :: TcGblEnv -> SDoc
1301 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1302 tcg_insts = dfun_ids,
1304 tcg_imports = imports })
1305 = vcat [ ppr_types dfun_ids type_env
1306 , ppr_insts dfun_ids
1307 , vcat (map ppr rules)
1308 , ppr_gen_tycons (typeEnvTyCons type_env)
1309 , ptext SLIT("Dependent modules:") <+> ppr (moduleEnvElts (imp_dep_mods imports))
1310 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1312 pprModGuts :: ModGuts -> SDoc
1313 pprModGuts (ModGuts { mg_types = type_env,
1315 = vcat [ ppr_types [] type_env,
1319 ppr_types :: [Instance] -> TypeEnv -> SDoc
1320 ppr_types ispecs type_env
1321 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1323 dfun_ids = map instanceDFunId ispecs
1324 ids = [id | id <- typeEnvIds type_env, want_sig id]
1325 want_sig id | opt_PprStyle_Debug = True
1326 | otherwise = isLocalId id &&
1327 isExternalName (idName id) &&
1328 not (id `elem` dfun_ids)
1329 -- isLocalId ignores data constructors, records selectors etc.
1330 -- The isExternalName ignores local dictionary and method bindings
1331 -- that the type checker has invented. Top-level user-defined things
1332 -- have External names.
1334 ppr_insts :: [Instance] -> SDoc
1335 ppr_insts [] = empty
1336 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1338 ppr_sigs :: [Var] -> SDoc
1340 -- Print type signatures; sort by OccName
1341 = vcat (map ppr_sig (sortLe le_sig ids))
1343 le_sig id1 id2 = getOccName id1 <= getOccName id2
1344 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1346 ppr_rules :: [CoreRule] -> SDoc
1347 ppr_rules [] = empty
1348 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1349 nest 4 (pprRules rs),
1352 ppr_gen_tycons [] = empty
1353 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1354 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]