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, plusOccEnv )
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, isInternalName )
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 = plusOccEnv (tcg_rdr_env gbl) 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 let { liftM2' fn a b = do a' <- a; b' <- b; return (fn a' b') } ;
234 exports <- mkExportNameSet (isJust maybe_mod) (liftM2' (,) rn_exports export_ies) ;
236 -- Check whether the entire module is deprecated
237 -- This happens only once per module
238 let { mod_deprecs = checkModDeprec mod_deprec } ;
240 -- Add exports and deprecations to envt
241 let { final_env = tcg_env { tcg_exports = exports,
242 tcg_rn_exports = if save_rn_syntax then
245 tcg_dus = tcg_dus tcg_env `plusDU` usesOnly exports,
246 tcg_deprecs = tcg_deprecs tcg_env `plusDeprecs`
248 -- A module deprecation over-rides the earlier ones
251 -- Report unused names
252 reportUnusedNames export_ies final_env ;
254 -- Dump output and return
260 -- The program is not allowed to contain two modules with the same
261 -- name, and we check for that here. It could happen if the home package
262 -- contains a module that is also present in an external package, for example.
263 checkConflicts imports this_mod and_then = do
266 dep_mods = this_mod : map fst (moduleEnvElts (imp_dep_mods imports))
267 -- don't forget to include the current module!
269 mb_dep_pkgs = checkForPackageConflicts
270 dflags dep_mods (imp_dep_pkgs imports)
276 updGblEnv (\gbl -> gbl{ tcg_home_mods = mkHomeModules dep_mods })
281 %************************************************************************
283 Type-checking external-core modules
285 %************************************************************************
288 tcRnExtCore :: HscEnv
290 -> IO (Messages, Maybe ModGuts)
291 -- Nothing => some error occurred
293 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
294 -- The decls are IfaceDecls; all names are original names
295 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
297 initTc hsc_env ExtCoreFile this_mod $ do {
299 let { ldecls = map noLoc decls } ;
301 -- Deal with the type declarations; first bring their stuff
302 -- into scope, then rname them, then type check them
303 tcg_env <- importsFromLocalDecls (mkFakeGroup ldecls) ;
305 setGblEnv tcg_env $ do {
307 rn_decls <- rnTyClDecls ldecls ;
310 -- Dump trace of renaming part
311 rnDump (ppr rn_decls) ;
313 -- Typecheck them all together so that
314 -- any mutually recursive types are done right
315 tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails rn_decls) ;
316 -- Make the new type env available to stuff slurped from interface files
318 setGblEnv tcg_env $ do {
320 -- Now the core bindings
321 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
325 bndrs = bindersOfBinds core_binds ;
326 my_exports = mkNameSet (map idName bndrs) ;
327 -- ToDo: export the data types also?
329 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
331 mod_guts = ModGuts { mg_module = this_mod,
333 mg_usages = [], -- ToDo: compute usage
334 mg_dir_imps = [], -- ??
335 mg_deps = noDependencies, -- ??
336 mg_home_mods = mkHomeModules [], -- ?? wrong!!
337 mg_exports = my_exports,
338 mg_types = final_type_env,
339 mg_insts = tcg_insts tcg_env,
341 mg_binds = core_binds,
344 mg_rdr_env = emptyGlobalRdrEnv,
345 mg_fix_env = emptyFixityEnv,
346 mg_deprecs = NoDeprecs,
350 tcCoreDump mod_guts ;
355 mkFakeGroup decls -- Rather clumsy; lots of unused fields
356 = emptyRdrGroup { hs_tyclds = decls }
360 %************************************************************************
362 Type-checking the top level of a module
364 %************************************************************************
367 tcRnSrcDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
368 -- Returns the variables free in the decls
369 -- Reason: solely to report unused imports and bindings
371 = do { -- Load the hi-boot interface for this module, if any
372 -- We do this now so that the boot_names can be passed
373 -- to tcTyAndClassDecls, because the boot_names are
374 -- automatically considered to be loop breakers
376 boot_iface <- tcHiBootIface mod ;
378 -- Do all the declarations
379 (tc_envs, lie) <- getLIE (tc_rn_src_decls boot_iface decls) ;
381 -- tcSimplifyTop deals with constant or ambiguous InstIds.
382 -- How could there be ambiguous ones? They can only arise if a
383 -- top-level decl falls under the monomorphism
384 -- restriction, and no subsequent decl instantiates its
385 -- type. (Usually, ambiguous type variables are resolved
386 -- during the generalisation step.)
387 traceTc (text "Tc8") ;
388 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
389 -- Setting the global env exposes the instances to tcSimplifyTop
390 -- Setting the local env exposes the local Ids to tcSimplifyTop,
391 -- so that we get better error messages (monomorphism restriction)
393 -- Backsubstitution. This must be done last.
394 -- Even tcSimplifyTop may do some unification.
395 traceTc (text "Tc9") ;
396 let { (tcg_env, _) = tc_envs ;
397 TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
398 tcg_rules = rules, tcg_fords = fords } = tcg_env } ;
401 (bind_ids, binds', fords', rules') <- zonkTopDecls (binds `unionBags` inst_binds)
404 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
405 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
408 tcg_fords = fords' } } ;
410 -- Make the new type env available to stuff slurped from interface files
411 writeMutVar (tcg_type_env_var tcg_env) final_type_env ;
413 -- Compare the hi-boot iface (if any) with the real thing
414 dfun_binds <- checkHiBootIface tcg_env' boot_iface ;
416 return (tcg_env' { tcg_binds = tcg_binds tcg_env' `unionBags` dfun_binds })
419 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
420 -- Loops around dealing with each top level inter-splice group
421 -- in turn, until it's dealt with the entire module
422 tc_rn_src_decls boot_details ds
423 = do { let { (first_group, group_tail) = findSplice ds } ;
424 -- If ds is [] we get ([], Nothing)
426 -- Type check the decls up to, but not including, the first splice
427 tc_envs@(tcg_env,tcl_env) <- tcRnGroup boot_details first_group ;
429 -- Bale out if errors; for example, error recovery when checking
430 -- the RHS of 'main' can mean that 'main' is not in the envt for
431 -- the subsequent checkMain test
436 -- If there is no splice, we're nearly done
438 Nothing -> do { -- Last thing: check for `main'
439 tcg_env <- checkMain ;
440 return (tcg_env, tcl_env)
443 -- If there's a splice, we must carry on
444 Just (SpliceDecl splice_expr, rest_ds) -> do {
446 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
449 -- Rename the splice expression, and get its supporting decls
450 (rn_splice_expr, splice_fvs) <- rnLExpr splice_expr ;
451 failIfErrsM ; -- Don't typecheck if renaming failed
453 -- Execute the splice
454 spliced_decls <- tcSpliceDecls rn_splice_expr ;
456 -- Glue them on the front of the remaining decls and loop
457 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
458 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
463 %************************************************************************
465 Compiling hs-boot source files, and
466 comparing the hi-boot interface with the real thing
468 %************************************************************************
471 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
472 tcRnHsBootDecls decls
473 = do { let { (first_group, group_tail) = findSplice decls }
476 Just stuff -> spliceInHsBootErr stuff
479 -- Rename the declarations
480 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
481 ; setGblEnv tcg_env $ do {
483 -- Todo: check no foreign decls, no rules, no default decls
485 -- Typecheck type/class decls
486 ; traceTc (text "Tc2")
487 ; let tycl_decls = hs_tyclds rn_group
488 ; tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails tycl_decls)
489 ; setGblEnv tcg_env $ do {
491 -- Typecheck instance decls
492 ; traceTc (text "Tc3")
493 ; (tcg_env, inst_infos, _binds) <- tcInstDecls1 tycl_decls (hs_instds rn_group)
494 ; setGblEnv tcg_env $ do {
496 -- Typecheck value declarations
497 ; traceTc (text "Tc5")
498 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
501 -- No simplification or zonking to do
502 ; traceTc (text "Tc7a")
503 ; gbl_env <- getGblEnv
505 -- Make the final type-env
506 -- Include the dfun_ids so that their type sigs get
507 -- are written into the interface file
508 ; let { type_env0 = tcg_type_env gbl_env
509 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
510 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
511 ; dfun_ids = map iDFunId inst_infos }
512 ; return (gbl_env { tcg_type_env = type_env2 })
515 spliceInHsBootErr (SpliceDecl (L loc _), _)
516 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
519 Once we've typechecked the body of the module, we want to compare what
520 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
523 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM (LHsBinds Id)
524 -- Compare the hi-boot file for this module (if there is one)
525 -- with the type environment we've just come up with
526 -- In the common case where there is no hi-boot file, the list
527 -- of boot_names is empty.
529 -- The bindings we return give bindings for the dfuns defined in the
530 -- hs-boot file, such as $fbEqT = $fEqT
533 (TcGblEnv { tcg_insts = local_insts, tcg_type_env = local_type_env })
534 (ModDetails { md_insts = boot_insts, md_types = boot_type_env })
535 = do { mapM_ check_one (typeEnvElts boot_type_env)
536 ; dfun_binds <- mapM check_inst boot_insts
537 ; return (unionManyBags dfun_binds) }
543 = case lookupTypeEnv local_type_env name of
544 Nothing -> addErrTc (missingBootThing boot_thing)
545 Just real_thing -> check_thing boot_thing real_thing
547 name = getName boot_thing
549 no_check name = isWiredInName name -- No checking for wired-in names. In particular,
550 -- 'error' is handled by a rather gross hack
551 -- (see comments in GHC.Err.hs-boot)
552 || name `elem` dfun_names
553 dfun_names = map getName boot_insts
556 = case [dfun | inst <- local_insts,
557 let dfun = instanceDFunId inst,
558 idType dfun `tcEqType` boot_inst_ty ] of
559 [] -> do { addErrTc (instMisMatch boot_inst); return emptyBag }
560 (dfun:_) -> return (unitBag $ noLoc $ VarBind local_boot_dfun (nlHsVar dfun))
562 boot_dfun = instanceDFunId boot_inst
563 boot_inst_ty = idType boot_dfun
564 local_boot_dfun = mkExportedLocalId (idName boot_dfun) boot_inst_ty
567 check_thing (ATyCon boot_tc) (ATyCon real_tc)
568 | isSynTyCon boot_tc && isSynTyCon real_tc,
569 defn1 `tcEqType` substTyWith tvs2 (mkTyVarTys tvs1) defn2
572 | tyConKind boot_tc == tyConKind real_tc
575 (tvs1, defn1) = synTyConDefn boot_tc
576 (tvs2, defn2) = synTyConDefn boot_tc
578 check_thing (AnId boot_id) (AnId real_id)
579 | idType boot_id `tcEqType` idType real_id
582 check_thing (ADataCon dc1) (ADataCon dc2)
583 | idType (dataConWrapId dc1) `tcEqType` idType (dataConWrapId dc2)
586 -- Can't declare a class in a hi-boot file
588 check_thing boot_thing real_thing -- Default case; failure
589 = addErrAt (srcLocSpan (getSrcLoc real_thing))
590 (bootMisMatch real_thing)
593 missingBootThing thing
594 = ppr thing <+> ptext SLIT("is defined in the hs-boot file, but not in the module")
596 = ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file")
599 2 (ptext SLIT("is defined in the hs-boot file, but not in the module"))
603 %************************************************************************
605 Type-checking the top level of a module
607 %************************************************************************
609 tcRnGroup takes a bunch of top-level source-code declarations, and
611 * gets supporting declarations from interface files
614 * and augments the TcGblEnv with the results
616 In Template Haskell it may be called repeatedly for each group of
617 declarations. It expects there to be an incoming TcGblEnv in the
618 monad; it augments it and returns the new TcGblEnv.
621 tcRnGroup :: ModDetails -> HsGroup RdrName -> TcM (TcGblEnv, TcLclEnv)
622 -- Returns the variables free in the decls, for unused-binding reporting
623 tcRnGroup boot_details decls
624 = do { -- Rename the declarations
625 (tcg_env, rn_decls) <- rnTopSrcDecls decls ;
626 setGblEnv tcg_env $ do {
628 -- Typecheck the declarations
629 tcTopSrcDecls boot_details rn_decls
632 ------------------------------------------------
633 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
635 = do { -- Bring top level binders into scope
636 tcg_env <- importsFromLocalDecls group ;
637 setGblEnv tcg_env $ do {
639 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
641 -- Rename the source decls
642 (tcg_env, rn_decls) <- rnSrcDecls group ;
645 -- save the renamed syntax, if we want it
647 | Just grp <- tcg_rn_decls tcg_env
648 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
652 -- Dump trace of renaming part
653 rnDump (ppr rn_decls) ;
655 return (tcg_env', rn_decls)
658 ------------------------------------------------
659 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
660 tcTopSrcDecls boot_details
661 (HsGroup { hs_tyclds = tycl_decls,
662 hs_instds = inst_decls,
663 hs_fords = foreign_decls,
664 hs_defds = default_decls,
665 hs_ruleds = rule_decls,
666 hs_valds = val_binds })
667 = do { -- Type-check the type and class decls, and all imported decls
668 -- The latter come in via tycl_decls
669 traceTc (text "Tc2") ;
671 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
672 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
673 -- an error we'd better stop now, to avoid a cascade
675 -- Make these type and class decls available to stuff slurped from interface files
676 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
679 setGblEnv tcg_env $ do {
680 -- Source-language instances, including derivings,
681 -- and import the supporting declarations
682 traceTc (text "Tc3") ;
683 (tcg_env, inst_infos, deriv_binds) <- tcInstDecls1 tycl_decls inst_decls ;
684 setGblEnv tcg_env $ do {
686 -- Foreign import declarations next. No zonking necessary
687 -- here; we can tuck them straight into the global environment.
688 traceTc (text "Tc4") ;
689 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
690 tcExtendGlobalValEnv fi_ids $ do {
692 -- Default declarations
693 traceTc (text "Tc4a") ;
694 default_tys <- tcDefaults default_decls ;
695 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
697 -- Value declarations next
698 -- We also typecheck any extra binds that came out
699 -- of the "deriving" process (deriv_binds)
700 traceTc (text "Tc5") ;
701 (tc_val_binds, tcl_env) <- tcTopBinds (val_binds `plusHsValBinds` deriv_binds) ;
702 setLclTypeEnv tcl_env $ do {
704 -- Second pass over class and instance declarations,
705 traceTc (text "Tc6") ;
706 (inst_binds, tcl_env) <- tcInstDecls2 tycl_decls inst_infos ;
707 showLIE (text "after instDecls2") ;
710 -- They need to be zonked, so we return them
711 traceTc (text "Tc7") ;
712 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
715 rules <- tcRules rule_decls ;
718 traceTc (text "Tc7a") ;
719 tcg_env <- getGblEnv ;
720 let { all_binds = tc_val_binds `unionBags`
721 inst_binds `unionBags`
724 -- Extend the GblEnv with the (as yet un-zonked)
725 -- bindings, rules, foreign decls
726 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
727 tcg_rules = tcg_rules tcg_env ++ rules,
728 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
729 return (tcg_env', tcl_env)
734 %************************************************************************
738 %************************************************************************
741 checkMain :: TcM TcGblEnv
742 -- If we are in module Main, check that 'main' is defined.
744 = do { ghc_mode <- getGhcMode ;
745 tcg_env <- getGblEnv ;
747 let { main_mod = mainModIs dflags ;
748 main_fn = case mainFunIs dflags of {
749 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn)) ;
750 Nothing -> main_RDR_Unqual } } ;
752 check_main ghc_mode tcg_env main_mod main_fn
756 check_main ghc_mode tcg_env main_mod main_fn
758 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
762 = addErrCtxt mainCtxt $
763 do { mb_main <- lookupSrcOcc_maybe main_fn
764 -- Check that 'main' is in scope
765 -- It might be imported from another module!
767 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
771 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
772 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
773 -- :Main.main :: IO () = runMainIO main
775 ; (main_expr, ty) <- setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
778 -- The function that the RTS invokes is always :Main.main,
779 -- which we call root_main_id.
780 -- (Because GHC allows the user to have a module not called
781 -- Main as the main module, we can't rely on the main function
782 -- being called "Main.main". That's why root_main_id has a fixed
784 -- We also make root_main_id an implicit Id, by making main_name
785 -- its parent (hence (Just main_name)). That has the effect
786 -- of preventing its type and unfolding from getting out into
787 -- the interface file. Otherwise we can end up with two defns
788 -- for 'main' in the interface file!
790 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
791 (mkVarOccFS FSLIT("main"))
792 (Just main_name) (getSrcLoc main_name)
793 ; root_main_id = mkExportedLocalId root_main_name ty
794 ; main_bind = noLoc (VarBind root_main_id main_expr) }
796 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
798 tcg_dus = tcg_dus tcg_env
799 `plusDU` usesOnly (unitFV main_name)
800 -- Record the use of 'main', so that we don't
801 -- complain about it being defined but not used
805 mod = tcg_mod tcg_env
807 complain_no_main | ghc_mode == Interactive = return ()
808 | otherwise = failWithTc noMainMsg
809 -- In interactive mode, don't worry about the absence of 'main'
810 -- In other modes, fail altogether, so that we don't go on
811 -- and complain a second time when processing the export list.
813 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
814 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
815 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
818 %*********************************************************
822 %*********************************************************
826 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
827 setInteractiveContext hsc_env icxt thing_inside
829 -- Initialise the tcg_inst_env with instances
830 -- from all home modules. This mimics the more selective
831 -- call to hptInstances in tcRnModule
832 dfuns = hptInstances hsc_env (\mod -> True)
834 updGblEnv (\env -> env {
835 tcg_rdr_env = ic_rn_gbl_env icxt,
836 tcg_type_env = ic_type_env icxt,
837 tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
839 updLclEnv (\env -> env { tcl_rdr = ic_rn_local_env icxt }) $
841 do { traceTc (text "setIC" <+> ppr (ic_type_env icxt))
848 -> InteractiveContext
850 -> IO (Maybe (InteractiveContext, [Name], LHsExpr Id))
851 -- The returned [Name] is the same as the input except for
852 -- ExprStmt, in which case the returned [Name] is [itName]
854 -- The returned TypecheckedHsExpr is of type IO [ () ],
855 -- a list of the bound values, coerced to ().
857 tcRnStmt hsc_env ictxt rdr_stmt
858 = initTcPrintErrors hsc_env iNTERACTIVE $
859 setInteractiveContext hsc_env ictxt $ do {
861 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
862 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
863 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
866 -- The real work is done here
867 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
868 zonked_expr <- zonkTopLExpr tc_expr ;
869 zonked_ids <- zonkTopBndrs bound_ids ;
871 -- None of the Ids should be of unboxed type, because we
872 -- cast them all to HValues in the end!
873 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
875 traceTc (text "tcs 1") ;
876 let { -- (a) Make all the bound ids "global" ids, now that
877 -- they're notionally top-level bindings. This is
878 -- important: otherwise when we come to compile an expression
879 -- using these ids later, the byte code generator will consider
880 -- the occurrences to be free rather than global.
882 -- (b) Tidy their types; this is important, because :info may
883 -- ask to look at them, and :info expects the things it looks
884 -- up to have tidy types
885 global_ids = map globaliseAndTidy zonked_ids ;
887 -- Update the interactive context
888 rn_env = ic_rn_local_env ictxt ;
889 type_env = ic_type_env ictxt ;
891 bound_names = map idName global_ids ;
892 new_rn_env = extendLocalRdrEnv rn_env bound_names ;
894 -- Remove any shadowed bindings from the type_env;
895 -- they are inaccessible but might, I suppose, cause
896 -- a space leak if we leave them there
897 shadowed = [ n | name <- bound_names,
898 let rdr_name = mkRdrUnqual (nameOccName name),
899 Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ;
901 filtered_type_env = delListFromNameEnv type_env shadowed ;
902 new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ;
904 new_ic = ictxt { ic_rn_local_env = new_rn_env,
905 ic_type_env = new_type_env }
908 dumpOptTcRn Opt_D_dump_tc
909 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
910 text "Typechecked expr" <+> ppr zonked_expr]) ;
912 returnM (new_ic, bound_names, zonked_expr)
915 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
916 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
918 globaliseAndTidy :: Id -> Id
920 -- Give the Id a Global Name, and tidy its type
921 = setIdType (globaliseId VanillaGlobal id) tidy_type
923 tidy_type = tidyTopType (idType id)
926 Here is the grand plan, implemented in tcUserStmt
928 What you type The IO [HValue] that hscStmt returns
929 ------------- ------------------------------------
930 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
933 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
936 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
937 [NB: result not printed] bindings: [it]
939 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
940 result showable) bindings: [it]
942 expr (of non-IO type,
943 result not showable) ==> error
947 ---------------------------
948 type PlanResult = ([Id], LHsExpr Id)
949 type Plan = TcM PlanResult
951 runPlans :: [Plan] -> TcM PlanResult
952 -- Try the plans in order. If one fails (by raising an exn), try the next.
953 -- If one succeeds, take it.
954 runPlans [] = panic "runPlans"
956 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
959 mkPlan :: LStmt Name -> TcM PlanResult
960 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
961 = do { uniq <- newUnique -- is treated very specially
962 ; let fresh_it = itName uniq
963 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
964 matches = [mkMatch [] expr emptyLocalBinds]
965 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
966 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
967 (HsVar bindIOName) noSyntaxExpr
968 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
969 (HsVar thenIOName) placeHolderType
972 -- [it <- e; print it] but not if it::()
974 -- [let it = e; print it]
975 ; runPlans [ -- Plan A
976 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
977 ; it_ty <- zonkTcType (idType it_id)
978 ; ifM (isUnitTy it_ty) failM
981 -- Plan B; a naked bind statment
982 tcGhciStmts [bind_stmt],
984 -- Plan C; check that the let-binding is typeable all by itself.
985 -- If not, fail; if so, try to print it.
986 -- The two-step process avoids getting two errors: one from
987 -- the expression itself, and one from the 'print it' part
988 -- This two-step story is very clunky, alas
989 do { checkNoErrs (tcGhciStmts [let_stmt])
990 --- checkNoErrs defeats the error recovery of let-bindings
991 ; tcGhciStmts [let_stmt, print_it] }
994 mkPlan stmt@(L loc (BindStmt {}))
995 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
996 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
997 (HsVar thenIOName) placeHolderType
999 -- [stmt; print v] but not if v::()
1001 ; runPlans [do { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
1002 ; v_ty <- zonkTcType (idType v_id)
1003 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
1009 = tcGhciStmts [stmt]
1011 ---------------------------
1012 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
1014 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
1015 ret_id <- tcLookupId returnIOName ; -- return @ IO
1017 io_ty = mkTyConApp ioTyCon [] ;
1018 ret_ty = mkListTy unitTy ;
1019 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
1021 names = map unLoc (collectLStmtsBinders stmts) ;
1023 -- mk_return builds the expression
1024 -- returnIO @ [()] [coerce () x, .., coerce () z]
1026 -- Despite the inconvenience of building the type applications etc,
1027 -- this *has* to be done in type-annotated post-typecheck form
1028 -- because we are going to return a list of *polymorphic* values
1029 -- coerced to type (). If we built a *source* stmt
1030 -- return [coerce x, ..., coerce z]
1031 -- then the type checker would instantiate x..z, and we wouldn't
1032 -- get their *polymorphic* values. (And we'd get ambiguity errs
1033 -- if they were overloaded, since they aren't applied to anything.)
1034 mk_return ids = nlHsApp (noLoc $ TyApp (nlHsVar ret_id) [ret_ty])
1035 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1036 mk_item id = nlHsApp (noLoc $ TyApp (nlHsVar unsafeCoerceId) [idType id, unitTy])
1040 -- OK, we're ready to typecheck the stmts
1041 traceTc (text "tcs 2") ;
1042 ((tc_stmts, ids), lie) <- getLIE $
1043 tcStmts DoExpr (tcDoStmt io_ty) stmts io_ret_ty $ \ _ ->
1044 mappM tcLookupId names ;
1045 -- Look up the names right in the middle,
1046 -- where they will all be in scope
1048 -- Simplify the context
1049 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1050 -- checkNoErrs ensures that the plan fails if context redn fails
1052 return (ids, mkHsDictLet const_binds $
1053 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1058 tcRnExpr just finds the type of an expression
1062 -> InteractiveContext
1065 tcRnExpr hsc_env ictxt rdr_expr
1066 = initTcPrintErrors hsc_env iNTERACTIVE $
1067 setInteractiveContext hsc_env ictxt $ do {
1069 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1072 -- Now typecheck the expression;
1073 -- it might have a rank-2 type (e.g. :t runST)
1074 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1075 ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1076 tcSimplifyInteractive lie_top ;
1077 qtvs' <- mappM zonkQuantifiedTyVar qtvs ;
1079 let { all_expr_ty = mkForAllTys qtvs' $
1080 mkFunTys (map idType dict_ids) $
1082 zonkTcType all_expr_ty
1085 smpl_doc = ptext SLIT("main expression")
1088 tcRnType just finds the kind of a type
1092 -> InteractiveContext
1095 tcRnType hsc_env ictxt rdr_type
1096 = initTcPrintErrors hsc_env iNTERACTIVE $
1097 setInteractiveContext hsc_env ictxt $ do {
1099 rn_type <- rnLHsType doc rdr_type ;
1102 -- Now kind-check the type
1103 (ty', kind) <- kcHsType rn_type ;
1107 doc = ptext SLIT("In GHCi input")
1113 %************************************************************************
1115 More GHCi stuff, to do with browsing and getting info
1117 %************************************************************************
1121 -- ASSUMES that the module is either in the HomePackageTable or is
1122 -- a package module with an interface on disk. If neither of these is
1123 -- true, then the result will be an error indicating the interface
1124 -- could not be found.
1125 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe NameSet)
1126 getModuleExports hsc_env mod
1127 = initTc hsc_env HsSrcFile iNTERACTIVE (tcGetModuleExports mod)
1129 tcGetModuleExports :: Module -> TcM NameSet
1130 tcGetModuleExports mod = do
1131 iface <- load_iface mod
1132 loadOrphanModules (dep_orphs (mi_deps iface))
1133 -- Load any orphan-module interfaces,
1134 -- so their instances are visible
1135 ifaceExportNames (mi_exports iface)
1137 load_iface mod = loadSrcInterface doc mod False {- Not boot iface -}
1139 doc = ptext SLIT("context for compiling statements")
1142 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1143 tcRnLookupRdrName hsc_env rdr_name
1144 = initTcPrintErrors hsc_env iNTERACTIVE $
1145 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1146 lookup_rdr_name rdr_name
1148 lookup_rdr_name rdr_name = do {
1149 -- If the identifier is a constructor (begins with an
1150 -- upper-case letter), then we need to consider both
1151 -- constructor and type class identifiers.
1152 let { rdr_names = dataTcOccs rdr_name } ;
1154 -- results :: [Either Messages Name]
1155 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1157 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1158 -- The successful lookups will be (Just name)
1159 let { (warns_s, good_names) = unzip [ (msgs, name)
1160 | (msgs, Just name) <- results] ;
1161 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1163 -- Fail if nothing good happened, else add warnings
1164 if null good_names then
1165 -- No lookup succeeded, so
1166 -- pick the first error message and report it
1167 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1168 -- while the other is "X is not in scope",
1169 -- we definitely want the former; but we might pick the latter
1170 do { addMessages (head errs_s) ; failM }
1171 else -- Add deprecation warnings
1172 mapM_ addMessages warns_s ;
1178 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1179 tcRnLookupName hsc_env name
1180 = initTcPrintErrors hsc_env iNTERACTIVE $
1181 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1185 tcRnGetInfo :: HscEnv
1187 -> IO (Maybe (TyThing, Fixity, [Instance]))
1189 -- Used to implemnent :info in GHCi
1191 -- Look up a RdrName and return all the TyThings it might be
1192 -- A capitalised RdrName is given to us in the DataName namespace,
1193 -- but we want to treat it as *both* a data constructor
1194 -- *and* as a type or class constructor;
1195 -- hence the call to dataTcOccs, and we return up to two results
1196 tcRnGetInfo hsc_env name
1197 = initTcPrintErrors hsc_env iNTERACTIVE $
1198 let ictxt = hsc_IC hsc_env in
1199 setInteractiveContext hsc_env ictxt $ do
1201 -- Load the interface for all unqualified types and classes
1202 -- That way we will find all the instance declarations
1203 -- (Packages have not orphan modules, and we assume that
1204 -- in the home package all relevant modules are loaded.)
1205 loadUnqualIfaces ictxt
1207 thing <- tcLookupGlobal name
1208 fixity <- lookupFixityRn name
1209 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1210 return (thing, fixity, ispecs)
1213 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1214 -- Filter the instances by the ones whose tycons (or clases resp)
1215 -- are in scope unqualified. Otherwise we list a whole lot too many!
1216 lookupInsts print_unqual (AClass cls)
1217 = do { inst_envs <- tcGetInstEnvs
1219 | ispec <- classInstances inst_envs cls
1220 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1222 lookupInsts print_unqual (ATyCon tc)
1223 = do { eps <- getEps -- Load all instances for all classes that are
1224 -- in the type environment (which are all the ones
1225 -- we've seen in any interface file so far)
1226 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1228 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1229 , let dfun = instanceDFunId ispec
1231 , plausibleDFun print_unqual dfun ] }
1233 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1234 tc_name = tyConName tc
1236 lookupInsts print_unqual other = return []
1238 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1239 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1241 ok name | isBuiltInSyntax name = True
1242 | isExternalName name = print_unqual (nameModule name) (nameOccName name)
1245 loadUnqualIfaces :: InteractiveContext -> TcM ()
1246 -- Load the home module for everything that is in scope unqualified
1247 -- This is so that we can accurately report the instances for
1249 loadUnqualIfaces ictxt
1251 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1253 unqual_mods = [ nameModule name
1254 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1255 let name = gre_name gre,
1256 not (isInternalName name),
1257 isTcOcc (nameOccName name), -- Types and classes only
1258 unQualOK gre ] -- In scope unqualified
1259 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1263 %************************************************************************
1267 %************************************************************************
1270 rnDump :: SDoc -> TcRn ()
1271 -- Dump, with a banner, if -ddump-rn
1272 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1274 tcDump :: TcGblEnv -> TcRn ()
1276 = do { dflags <- getDOpts ;
1278 -- Dump short output if -ddump-types or -ddump-tc
1279 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1280 (dumpTcRn short_dump) ;
1282 -- Dump bindings if -ddump-tc
1283 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1286 short_dump = pprTcGblEnv env
1287 full_dump = pprLHsBinds (tcg_binds env)
1288 -- NB: foreign x-d's have undefined's in their types;
1289 -- hence can't show the tc_fords
1292 = do { dflags <- getDOpts ;
1293 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1294 (dumpTcRn (pprModGuts mod_guts)) ;
1296 -- Dump bindings if -ddump-tc
1297 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1299 full_dump = pprCoreBindings (mg_binds mod_guts)
1301 -- It's unpleasant having both pprModGuts and pprModDetails here
1302 pprTcGblEnv :: TcGblEnv -> SDoc
1303 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1304 tcg_insts = dfun_ids,
1306 tcg_imports = imports })
1307 = vcat [ ppr_types dfun_ids type_env
1308 , ppr_insts dfun_ids
1309 , vcat (map ppr rules)
1310 , ppr_gen_tycons (typeEnvTyCons type_env)
1311 , ptext SLIT("Dependent modules:") <+> ppr (moduleEnvElts (imp_dep_mods imports))
1312 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1314 pprModGuts :: ModGuts -> SDoc
1315 pprModGuts (ModGuts { mg_types = type_env,
1317 = vcat [ ppr_types [] type_env,
1321 ppr_types :: [Instance] -> TypeEnv -> SDoc
1322 ppr_types ispecs type_env
1323 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1325 dfun_ids = map instanceDFunId ispecs
1326 ids = [id | id <- typeEnvIds type_env, want_sig id]
1327 want_sig id | opt_PprStyle_Debug = True
1328 | otherwise = isLocalId id &&
1329 isExternalName (idName id) &&
1330 not (id `elem` dfun_ids)
1331 -- isLocalId ignores data constructors, records selectors etc.
1332 -- The isExternalName ignores local dictionary and method bindings
1333 -- that the type checker has invented. Top-level user-defined things
1334 -- have External names.
1336 ppr_insts :: [Instance] -> SDoc
1337 ppr_insts [] = empty
1338 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1340 ppr_sigs :: [Var] -> SDoc
1342 -- Print type signatures; sort by OccName
1343 = vcat (map ppr_sig (sortLe le_sig ids))
1345 le_sig id1 id2 = getOccName id1 <= getOccName id2
1346 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1348 ppr_rules :: [CoreRule] -> SDoc
1349 ppr_rules [] = empty
1350 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1351 nest 4 (pprRules rs),
1354 ppr_gen_tycons [] = empty
1355 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1356 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]