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 ( moduleToPackageConfig, mkPackageId, package,
31 import HsSyn ( HsModule(..), HsExtCore(..), HsGroup(..), LHsDecl,
32 SpliceDecl(..), HsBind(..), LHsBinds,
33 emptyGroup, appendGroups,
34 nlHsApp, nlHsVar, pprLHsBinds )
35 import RdrHsSyn ( findSplice )
37 import PrelNames ( runMainIOName, rootMainName, mAIN,
39 import RdrName ( RdrName, mkRdrUnqual, emptyGlobalRdrEnv )
40 import TcHsSyn ( zonkTopDecls )
41 import TcExpr ( tcInferRho )
43 import TcType ( tidyTopType, tcEqType, mkTyVarTys, substTyWith )
44 import Inst ( showLIE )
45 import InstEnv ( extendInstEnvList, Instance, pprInstances, instanceDFunId )
46 import TcBinds ( tcTopBinds, tcHsBootSigs )
47 import TcDefaults ( tcDefaults )
48 import TcEnv ( tcExtendGlobalValEnv, iDFunId )
49 import TcRules ( tcRules )
50 import TcForeign ( tcForeignImports, tcForeignExports )
51 import TcInstDcls ( tcInstDecls1, tcInstDecls2 )
52 import TcIface ( tcExtCoreBindings, tcHiBootIface )
53 import TcSimplify ( tcSimplifyTop )
54 import TcTyClsDecls ( tcTyAndClassDecls )
55 import LoadIface ( loadOrphanModules )
56 import RnNames ( importsFromLocalDecls, rnImports, rnExports,
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, mkModule, moduleEnvElts, elemModuleEnv )
67 import OccName ( mkVarOcc )
68 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(..), HsBindGroup(..),
86 LStmt, LHsExpr, LHsType, mkVarBind,
87 collectLStmtsBinders, collectLStmtBinders, nlVarPat,
88 placeHolderType, noSyntaxExpr )
89 import RdrName ( GlobalRdrElt(..), globalRdrEnvElts,
90 unQualOK, lookupLocalRdrEnv, extendLocalRdrEnv )
91 import RnSource ( addTcgDUs )
92 import TcHsSyn ( mkHsLet, zonkTopLExpr, zonkTopBndrs )
93 import TcHsType ( kcHsType )
94 import TcMType ( zonkTcType, zonkQuantifiedTyVar )
95 import TcMatches ( tcStmts, tcDoStmt )
96 import TcSimplify ( tcSimplifyInteractive, tcSimplifyInfer )
97 import TcType ( Type, mkForAllTys, mkFunTys, mkTyConApp, tyVarsOfType, isTauTy,
98 isUnLiftedType, tyClsNamesOfDFunHead, tyClsNamesOfType, isUnitTy )
99 import TcEnv ( tcLookupTyCon, tcLookupId, tcLookupGlobal )
100 import RnTypes ( rnLHsType )
101 import Inst ( tcGetInstEnvs )
102 import InstEnv ( classInstances, instEnvElts )
103 import RnExpr ( rnStmts, rnLExpr )
104 import LoadIface ( loadSrcInterface, loadSysInterface )
105 import IfaceEnv ( ifaceExportNames )
106 import Module ( moduleSetElts, mkModuleSet )
107 import RnEnv ( lookupOccRn, dataTcOccs, lookupFixityRn )
108 import Id ( setIdType )
109 import MkId ( unsafeCoerceId )
110 import TyCon ( tyConName )
111 import TysWiredIn ( mkListTy, unitTy )
112 import IdInfo ( GlobalIdDetails(..) )
114 import Var ( globaliseId )
115 import Name ( nameOccName, nameModule, isBuiltInSyntax )
116 import OccName ( isTcOcc )
117 import NameEnv ( delListFromNameEnv )
118 import PrelNames ( iNTERACTIVE, ioTyConName, printName, itName,
119 bindIOName, thenIOName, returnIOName )
120 import HscTypes ( InteractiveContext(..),
121 ModIface(..), icPrintUnqual,
123 import BasicTypes ( RecFlag(..), Fixity )
124 import SrcLoc ( unLoc, noSrcSpan )
127 import FastString ( mkFastString )
128 import Util ( sortLe )
129 import Bag ( unionBags, snocBag, emptyBag, unitBag, unionManyBags )
131 import Maybe ( isJust )
136 %************************************************************************
138 Typecheck and rename a module
140 %************************************************************************
146 -> Bool -- True <=> save renamed syntax
147 -> Located (HsModule RdrName)
148 -> IO (Messages, Maybe TcGblEnv)
150 tcRnModule hsc_env hsc_src save_rn_decls
151 (L loc (HsModule maybe_mod export_ies
152 import_decls local_decls mod_deprec))
153 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
155 let { this_mod = case maybe_mod of
156 Nothing -> mAIN -- 'module M where' is omitted
157 Just (L _ mod) -> mod } ; -- The normal case
159 initTc hsc_env hsc_src this_mod $
162 checkForPackageModule (hsc_dflags hsc_env) 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 -- Update the gbl env
187 gbl { tcg_rdr_env = rdr_env,
188 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
189 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
190 tcg_rn_decls = if save_rn_decls then
196 traceRn (text "rn1" <+> ppr (imp_dep_mods imports)) ;
197 -- Fail if there are any errors so far
198 -- The error printing (if needed) takes advantage
199 -- of the tcg_env we have now set
202 -- Load any orphan-module interfaces, so that
203 -- their rules and instance decls will be found
204 loadOrphanModules (imp_orphs imports) ;
206 traceRn (text "rn1a") ;
207 -- Rename and type check the declarations
208 tcg_env <- if isHsBoot hsc_src then
209 tcRnHsBootDecls local_decls
211 tcRnSrcDecls local_decls ;
212 setGblEnv tcg_env $ do {
214 traceRn (text "rn3") ;
216 -- Report the use of any deprecated things
217 -- We do this before processsing the export list so
218 -- that we don't bleat about re-exporting a deprecated
219 -- thing (especially via 'module Foo' export item)
220 -- Only uses in the body of the module are complained about
221 reportDeprecations tcg_env ;
223 -- Process the export list
224 exports <- rnExports (isJust maybe_mod) export_ies ;
226 -- Check whether the entire module is deprecated
227 -- This happens only once per module
228 let { mod_deprecs = checkModDeprec mod_deprec } ;
230 -- Add exports and deprecations to envt
231 let { final_env = tcg_env { tcg_exports = exports,
232 tcg_dus = tcg_dus tcg_env `plusDU` usesOnly exports,
233 tcg_deprecs = tcg_deprecs tcg_env `plusDeprecs`
235 -- A module deprecation over-rides the earlier ones
238 -- Report unused names
239 reportUnusedNames export_ies final_env ;
241 -- Dump output and return
246 -- This is really a sanity check that the user has given -package-name
247 -- if necessary. -package-name is only necessary when the package database
248 -- already contains the current package, because then we can't tell
249 -- whether a given module is in the current package or not, without knowing
250 -- the name of the current package.
251 checkForPackageModule dflags this_mod
252 | not (isHomeModule dflags this_mod),
253 Just (pkg,_) <- moduleToPackageConfig dflags this_mod =
255 ppr_pkg = ppr (mkPackageId (package pkg))
257 addErr (ptext SLIT("Module") <+> quotes (ppr this_mod) <+>
258 ptext SLIT("is a member of package") <+> ppr_pkg <> char '.' $$
259 ptext SLIT("To compile this module, please use -ignore-package") <+> ppr_pkg <> char '.')
260 | otherwise = return ()
264 %************************************************************************
266 Type-checking external-core modules
268 %************************************************************************
271 tcRnExtCore :: HscEnv
273 -> IO (Messages, Maybe ModGuts)
274 -- Nothing => some error occurred
276 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
277 -- The decls are IfaceDecls; all names are original names
278 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
280 initTc hsc_env ExtCoreFile this_mod $ do {
282 let { ldecls = map noLoc decls } ;
284 -- Deal with the type declarations; first bring their stuff
285 -- into scope, then rname them, then type check them
286 tcg_env <- importsFromLocalDecls (mkFakeGroup ldecls) ;
288 setGblEnv tcg_env $ do {
290 rn_decls <- rnTyClDecls ldecls ;
293 -- Dump trace of renaming part
294 rnDump (ppr rn_decls) ;
296 -- Typecheck them all together so that
297 -- any mutually recursive types are done right
298 tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails rn_decls) ;
299 -- Make the new type env available to stuff slurped from interface files
301 setGblEnv tcg_env $ do {
303 -- Now the core bindings
304 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
308 bndrs = bindersOfBinds core_binds ;
309 my_exports = mkNameSet (map idName bndrs) ;
310 -- ToDo: export the data types also?
312 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
314 mod_guts = ModGuts { mg_module = this_mod,
316 mg_usages = [], -- ToDo: compute usage
317 mg_dir_imps = [], -- ??
318 mg_deps = noDependencies, -- ??
319 mg_exports = my_exports,
320 mg_types = final_type_env,
321 mg_insts = tcg_insts tcg_env,
323 mg_binds = core_binds,
326 mg_rdr_env = emptyGlobalRdrEnv,
327 mg_fix_env = emptyFixityEnv,
328 mg_deprecs = NoDeprecs,
332 tcCoreDump mod_guts ;
337 mkFakeGroup decls -- Rather clumsy; lots of unused fields
338 = HsGroup { hs_tyclds = decls, -- This is the one we want
339 hs_valds = [], hs_fords = [],
340 hs_instds = [], hs_fixds = [], hs_depds = [],
341 hs_ruleds = [], hs_defds = [] }
345 %************************************************************************
347 Type-checking the top level of a module
349 %************************************************************************
352 tcRnSrcDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
353 -- Returns the variables free in the decls
354 -- Reason: solely to report unused imports and bindings
356 = do { -- Load the hi-boot interface for this module, if any
357 -- We do this now so that the boot_names can be passed
358 -- to tcTyAndClassDecls, because the boot_names are
359 -- automatically considered to be loop breakers
361 boot_iface <- tcHiBootIface mod ;
363 -- Do all the declarations
364 (tc_envs, lie) <- getLIE (tc_rn_src_decls boot_iface decls) ;
366 -- tcSimplifyTop deals with constant or ambiguous InstIds.
367 -- How could there be ambiguous ones? They can only arise if a
368 -- top-level decl falls under the monomorphism
369 -- restriction, and no subsequent decl instantiates its
370 -- type. (Usually, ambiguous type variables are resolved
371 -- during the generalisation step.)
372 traceTc (text "Tc8") ;
373 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
374 -- Setting the global env exposes the instances to tcSimplifyTop
375 -- Setting the local env exposes the local Ids to tcSimplifyTop,
376 -- so that we get better error messages (monomorphism restriction)
378 -- Backsubstitution. This must be done last.
379 -- Even tcSimplifyTop may do some unification.
380 traceTc (text "Tc9") ;
381 let { (tcg_env, _) = tc_envs ;
382 TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
383 tcg_rules = rules, tcg_fords = fords } = tcg_env } ;
385 (bind_ids, binds', fords', rules') <- zonkTopDecls (binds `unionBags` inst_binds)
388 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
389 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
392 tcg_fords = fords' } } ;
394 -- Make the new type env available to stuff slurped from interface files
395 writeMutVar (tcg_type_env_var tcg_env) final_type_env ;
397 -- Compare the hi-boot iface (if any) with the real thing
398 dfun_binds <- checkHiBootIface tcg_env' boot_iface ;
400 return (tcg_env' { tcg_binds = tcg_binds tcg_env' `unionBags` dfun_binds })
403 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
404 -- Loops around dealing with each top level inter-splice group
405 -- in turn, until it's dealt with the entire module
406 tc_rn_src_decls boot_details ds
407 = do { let { (first_group, group_tail) = findSplice ds } ;
408 -- If ds is [] we get ([], Nothing)
410 -- Type check the decls up to, but not including, the first splice
411 tc_envs@(tcg_env,tcl_env) <- tcRnGroup boot_details first_group ;
413 -- Bale out if errors; for example, error recovery when checking
414 -- the RHS of 'main' can mean that 'main' is not in the envt for
415 -- the subsequent checkMain test
420 -- If there is no splice, we're nearly done
422 Nothing -> do { -- Last thing: check for `main'
423 tcg_env <- checkMain ;
424 return (tcg_env, tcl_env)
427 -- If there's a splice, we must carry on
428 Just (SpliceDecl splice_expr, rest_ds) -> do {
430 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
433 -- Rename the splice expression, and get its supporting decls
434 (rn_splice_expr, splice_fvs) <- rnLExpr splice_expr ;
435 failIfErrsM ; -- Don't typecheck if renaming failed
437 -- Execute the splice
438 spliced_decls <- tcSpliceDecls rn_splice_expr ;
440 -- Glue them on the front of the remaining decls and loop
441 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
442 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
447 %************************************************************************
449 Compiling hs-boot source files, and
450 comparing the hi-boot interface with the real thing
452 %************************************************************************
455 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
456 tcRnHsBootDecls decls
457 = do { let { (first_group, group_tail) = findSplice decls }
460 Just stuff -> spliceInHsBootErr stuff
463 -- Rename the declarations
464 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
465 ; setGblEnv tcg_env $ do {
467 -- Todo: check no foreign decls, no rules, no default decls
469 -- Typecheck type/class decls
470 ; traceTc (text "Tc2")
471 ; let tycl_decls = hs_tyclds rn_group
472 ; tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails tycl_decls)
473 ; setGblEnv tcg_env $ do {
475 -- Typecheck instance decls
476 ; traceTc (text "Tc3")
477 ; (tcg_env, inst_infos, _binds) <- tcInstDecls1 tycl_decls (hs_instds rn_group)
478 ; setGblEnv tcg_env $ do {
480 -- Typecheck value declarations
481 ; traceTc (text "Tc5")
482 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
485 -- No simplification or zonking to do
486 ; traceTc (text "Tc7a")
487 ; gbl_env <- getGblEnv
489 -- Make the final type-env
490 -- Include the dfun_ids so that their type sigs get
491 -- are written into the interface file
492 ; let { type_env0 = tcg_type_env gbl_env
493 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
494 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
495 ; dfun_ids = map iDFunId inst_infos }
496 ; return (gbl_env { tcg_type_env = type_env2 })
499 spliceInHsBootErr (SpliceDecl (L loc _), _)
500 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
503 Once we've typechecked the body of the module, we want to compare what
504 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
507 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM (LHsBinds Id)
508 -- Compare the hi-boot file for this module (if there is one)
509 -- with the type environment we've just come up with
510 -- In the common case where there is no hi-boot file, the list
511 -- of boot_names is empty.
513 -- The bindings we return give bindings for the dfuns defined in the
514 -- hs-boot file, such as $fbEqT = $fEqT
517 (TcGblEnv { tcg_insts = local_insts, tcg_type_env = local_type_env })
518 (ModDetails { md_insts = boot_insts, md_types = boot_type_env })
519 = do { mapM_ check_one (typeEnvElts boot_type_env)
520 ; dfun_binds <- mapM check_inst boot_insts
521 ; return (unionManyBags dfun_binds) }
527 = case lookupTypeEnv local_type_env name of
528 Nothing -> addErrTc (missingBootThing boot_thing)
529 Just real_thing -> check_thing boot_thing real_thing
531 name = getName boot_thing
533 no_check name = isWiredInName name -- No checking for wired-in names. In particular,
534 -- 'error' is handled by a rather gross hack
535 -- (see comments in GHC.Err.hs-boot)
536 || name `elem` dfun_names
537 dfun_names = map getName boot_insts
540 = case [dfun | inst <- local_insts,
541 let dfun = instanceDFunId inst,
542 idType dfun `tcEqType` boot_inst_ty ] of
543 [] -> do { addErrTc (instMisMatch boot_inst); return emptyBag }
544 (dfun:_) -> return (unitBag $ noLoc $ VarBind local_boot_dfun (nlHsVar dfun))
546 boot_dfun = instanceDFunId boot_inst
547 boot_inst_ty = idType boot_dfun
548 local_boot_dfun = mkExportedLocalId (idName boot_dfun) boot_inst_ty
551 check_thing (ATyCon boot_tc) (ATyCon real_tc)
552 | isSynTyCon boot_tc && isSynTyCon real_tc,
553 defn1 `tcEqType` substTyWith tvs2 (mkTyVarTys tvs1) defn2
556 | tyConKind boot_tc == tyConKind real_tc
559 (tvs1, defn1) = getSynTyConDefn boot_tc
560 (tvs2, defn2) = getSynTyConDefn boot_tc
562 check_thing (AnId boot_id) (AnId real_id)
563 | idType boot_id `tcEqType` idType real_id
566 check_thing (ADataCon dc1) (ADataCon dc2)
567 | idType (dataConWrapId dc1) `tcEqType` idType (dataConWrapId dc2)
570 -- Can't declare a class in a hi-boot file
572 check_thing boot_thing real_thing -- Default case; failure
573 = addErrAt (srcLocSpan (getSrcLoc real_thing))
574 (bootMisMatch real_thing)
577 missingBootThing thing
578 = ppr thing <+> ptext SLIT("is defined in the hs-boot file, but not in the module")
580 = ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file")
583 2 (ptext SLIT("is defined in the hs-boot file, but not in the module"))
587 %************************************************************************
589 Type-checking the top level of a module
591 %************************************************************************
593 tcRnGroup takes a bunch of top-level source-code declarations, and
595 * gets supporting declarations from interface files
598 * and augments the TcGblEnv with the results
600 In Template Haskell it may be called repeatedly for each group of
601 declarations. It expects there to be an incoming TcGblEnv in the
602 monad; it augments it and returns the new TcGblEnv.
605 tcRnGroup :: ModDetails -> HsGroup RdrName -> TcM (TcGblEnv, TcLclEnv)
606 -- Returns the variables free in the decls, for unused-binding reporting
607 tcRnGroup boot_details decls
608 = do { -- Rename the declarations
609 (tcg_env, rn_decls) <- rnTopSrcDecls decls ;
610 setGblEnv tcg_env $ do {
612 -- Typecheck the declarations
613 tcTopSrcDecls boot_details rn_decls
616 ------------------------------------------------
617 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
619 = do { -- Bring top level binders into scope
620 tcg_env <- importsFromLocalDecls group ;
621 setGblEnv tcg_env $ do {
623 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
625 -- Rename the source decls
626 (tcg_env, rn_decls) <- rnSrcDecls group ;
629 -- save the renamed syntax, if we want it
631 | Just grp <- tcg_rn_decls tcg_env
632 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
636 -- Dump trace of renaming part
637 rnDump (ppr rn_decls) ;
639 return (tcg_env', rn_decls)
642 ------------------------------------------------
643 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
644 tcTopSrcDecls boot_details
645 (HsGroup { hs_tyclds = tycl_decls,
646 hs_instds = inst_decls,
647 hs_fords = foreign_decls,
648 hs_defds = default_decls,
649 hs_ruleds = rule_decls,
650 hs_valds = val_binds })
651 = do { -- Type-check the type and class decls, and all imported decls
652 -- The latter come in via tycl_decls
653 traceTc (text "Tc2") ;
655 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
656 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
657 -- an error we'd better stop now, to avoid a cascade
659 -- Make these type and class decls available to stuff slurped from interface files
660 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
663 setGblEnv tcg_env $ do {
664 -- Source-language instances, including derivings,
665 -- and import the supporting declarations
666 traceTc (text "Tc3") ;
667 (tcg_env, inst_infos, deriv_binds) <- tcInstDecls1 tycl_decls inst_decls ;
668 setGblEnv tcg_env $ do {
670 -- Foreign import declarations next. No zonking necessary
671 -- here; we can tuck them straight into the global environment.
672 traceTc (text "Tc4") ;
673 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
674 tcExtendGlobalValEnv fi_ids $ do {
676 -- Default declarations
677 traceTc (text "Tc4a") ;
678 default_tys <- tcDefaults default_decls ;
679 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
681 -- Value declarations next
682 -- We also typecheck any extra binds that came out
683 -- of the "deriving" process (deriv_binds)
684 traceTc (text "Tc5") ;
685 (tc_val_binds, tcl_env) <- tcTopBinds (val_binds ++ deriv_binds) ;
686 setLclTypeEnv tcl_env $ do {
688 -- Second pass over class and instance declarations,
689 traceTc (text "Tc6") ;
690 (inst_binds, tcl_env) <- tcInstDecls2 tycl_decls inst_infos ;
691 showLIE (text "after instDecls2") ;
694 -- They need to be zonked, so we return them
695 traceTc (text "Tc7") ;
696 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
699 rules <- tcRules rule_decls ;
702 traceTc (text "Tc7a") ;
703 tcg_env <- getGblEnv ;
704 let { all_binds = tc_val_binds `unionBags`
705 inst_binds `unionBags`
708 -- Extend the GblEnv with the (as yet un-zonked)
709 -- bindings, rules, foreign decls
710 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
711 tcg_rules = tcg_rules tcg_env ++ rules,
712 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
713 return (tcg_env', tcl_env)
718 %************************************************************************
722 %************************************************************************
725 checkMain :: TcM TcGblEnv
726 -- If we are in module Main, check that 'main' is defined.
728 = do { ghci_mode <- getGhciMode ;
729 tcg_env <- getGblEnv ;
731 let { main_mod = case mainModIs dflags of {
732 Just mod -> mkModule mod ;
734 main_fn = case mainFunIs dflags of {
735 Just fn -> mkRdrUnqual (mkVarOcc (mkFastString fn)) ;
736 Nothing -> main_RDR_Unqual } } ;
738 check_main ghci_mode tcg_env main_mod main_fn
742 check_main ghci_mode tcg_env main_mod main_fn
744 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
748 = addErrCtxt mainCtxt $
749 do { mb_main <- lookupSrcOcc_maybe main_fn
750 -- Check that 'main' is in scope
751 -- It might be imported from another module!
753 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
757 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
758 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
759 -- :Main.main :: IO () = runMainIO main
761 ; (main_expr, ty) <- setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
764 ; let { root_main_id = mkExportedLocalId rootMainName ty ;
765 main_bind = noLoc (VarBind root_main_id main_expr) }
767 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
769 tcg_dus = tcg_dus tcg_env
770 `plusDU` usesOnly (unitFV main_name)
771 -- Record the use of 'main', so that we don't
772 -- complain about it being defined but not used
776 mod = tcg_mod tcg_env
778 complain_no_main | ghci_mode == Interactive = return ()
779 | otherwise = failWithTc noMainMsg
780 -- In interactive mode, don't worry about the absence of 'main'
781 -- In other modes, fail altogether, so that we don't go on
782 -- and complain a second time when processing the export list.
784 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
785 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
786 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
789 %*********************************************************
793 %*********************************************************
797 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
798 setInteractiveContext hsc_env icxt thing_inside
800 -- Initialise the tcg_inst_env with instances
801 -- from all home modules. This mimics the more selective
802 -- call to hptInstances in tcRnModule
803 dfuns = hptInstances hsc_env (\mod -> True)
805 updGblEnv (\env -> env {
806 tcg_rdr_env = ic_rn_gbl_env icxt,
807 tcg_type_env = ic_type_env icxt,
808 tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
810 updLclEnv (\env -> env { tcl_rdr = ic_rn_local_env icxt }) $
812 do { traceTc (text "setIC" <+> ppr (ic_type_env icxt))
819 -> InteractiveContext
821 -> IO (Maybe (InteractiveContext, [Name], LHsExpr Id))
822 -- The returned [Name] is the same as the input except for
823 -- ExprStmt, in which case the returned [Name] is [itName]
825 -- The returned TypecheckedHsExpr is of type IO [ () ],
826 -- a list of the bound values, coerced to ().
828 tcRnStmt hsc_env ictxt rdr_stmt
829 = initTcPrintErrors hsc_env iNTERACTIVE $
830 setInteractiveContext hsc_env ictxt $ do {
832 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
833 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
834 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
837 -- The real work is done here
838 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
839 zonked_expr <- zonkTopLExpr tc_expr ;
840 zonked_ids <- zonkTopBndrs bound_ids ;
842 -- None of the Ids should be of unboxed type, because we
843 -- cast them all to HValues in the end!
844 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
846 traceTc (text "tcs 1") ;
847 let { -- (a) Make all the bound ids "global" ids, now that
848 -- they're notionally top-level bindings. This is
849 -- important: otherwise when we come to compile an expression
850 -- using these ids later, the byte code generator will consider
851 -- the occurrences to be free rather than global.
853 -- (b) Tidy their types; this is important, because :info may
854 -- ask to look at them, and :info expects the things it looks
855 -- up to have tidy types
856 global_ids = map globaliseAndTidy zonked_ids ;
858 -- Update the interactive context
859 rn_env = ic_rn_local_env ictxt ;
860 type_env = ic_type_env ictxt ;
862 bound_names = map idName global_ids ;
863 new_rn_env = extendLocalRdrEnv rn_env bound_names ;
865 -- Remove any shadowed bindings from the type_env;
866 -- they are inaccessible but might, I suppose, cause
867 -- a space leak if we leave them there
868 shadowed = [ n | name <- bound_names,
869 let rdr_name = mkRdrUnqual (nameOccName name),
870 Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ;
872 filtered_type_env = delListFromNameEnv type_env shadowed ;
873 new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ;
875 new_ic = ictxt { ic_rn_local_env = new_rn_env,
876 ic_type_env = new_type_env }
879 dumpOptTcRn Opt_D_dump_tc
880 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
881 text "Typechecked expr" <+> ppr zonked_expr]) ;
883 returnM (new_ic, bound_names, zonked_expr)
886 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
887 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
889 globaliseAndTidy :: Id -> Id
891 -- Give the Id a Global Name, and tidy its type
892 = setIdType (globaliseId VanillaGlobal id) tidy_type
894 tidy_type = tidyTopType (idType id)
897 Here is the grand plan, implemented in tcUserStmt
899 What you type The IO [HValue] that hscStmt returns
900 ------------- ------------------------------------
901 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
904 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
907 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
908 [NB: result not printed] bindings: [it]
910 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
911 result showable) bindings: [it]
913 expr (of non-IO type,
914 result not showable) ==> error
918 ---------------------------
919 type PlanResult = ([Id], LHsExpr Id)
920 type Plan = TcM PlanResult
922 runPlans :: [Plan] -> TcM PlanResult
923 -- Try the plans in order. If one fails (by raising an exn), try the next.
924 -- If one succeeds, take it.
925 runPlans [] = panic "runPlans"
927 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
930 mkPlan :: LStmt Name -> TcM PlanResult
931 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
932 = do { uniq <- newUnique -- is treated very specially
933 ; let fresh_it = itName uniq
934 the_bind = mkVarBind noSrcSpan fresh_it expr
935 let_stmt = L loc $ LetStmt [HsBindGroup (unitBag the_bind) [] NonRecursive]
936 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
937 (HsVar bindIOName) noSyntaxExpr
938 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
939 (HsVar thenIOName) placeHolderType
942 -- [it <- e; print it] but not if it::()
944 -- [let it = e; print it]
945 ; runPlans [ -- Plan A
946 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
947 ; it_ty <- zonkTcType (idType it_id)
948 ; ifM (isUnitTy it_ty) failM
951 -- Plan B; a naked bind statment
952 tcGhciStmts [bind_stmt],
954 -- Plan C; check that the let-binding is typeable all by itself.
955 -- If not, fail; if so, try to print it.
956 -- The two-step process avoids getting two errors: one from
957 -- the expression itself, and one from the 'print it' part
958 -- This two-step story is very clunky, alas
959 do { checkNoErrs (tcGhciStmts [let_stmt])
960 --- checkNoErrs defeats the error recovery of let-bindings
961 ; tcGhciStmts [let_stmt, print_it] }
964 mkPlan stmt@(L loc (BindStmt {}))
965 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
966 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
967 (HsVar thenIOName) placeHolderType
969 -- [stmt; print v] but not if v::()
971 ; runPlans [do { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
972 ; v_ty <- zonkTcType (idType v_id)
973 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
981 ---------------------------
982 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
984 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
985 ret_id <- tcLookupId returnIOName ; -- return @ IO
987 io_ty = mkTyConApp ioTyCon [] ;
988 ret_ty = mkListTy unitTy ;
989 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
991 names = map unLoc (collectLStmtsBinders stmts) ;
993 -- mk_return builds the expression
994 -- returnIO @ [()] [coerce () x, .., coerce () z]
996 -- Despite the inconvenience of building the type applications etc,
997 -- this *has* to be done in type-annotated post-typecheck form
998 -- because we are going to return a list of *polymorphic* values
999 -- coerced to type (). If we built a *source* stmt
1000 -- return [coerce x, ..., coerce z]
1001 -- then the type checker would instantiate x..z, and we wouldn't
1002 -- get their *polymorphic* values. (And we'd get ambiguity errs
1003 -- if they were overloaded, since they aren't applied to anything.)
1004 mk_return ids = nlHsApp (noLoc $ TyApp (nlHsVar ret_id) [ret_ty])
1005 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1006 mk_item id = nlHsApp (noLoc $ TyApp (nlHsVar unsafeCoerceId) [idType id, unitTy])
1010 -- OK, we're ready to typecheck the stmts
1011 traceTc (text "tcs 2") ;
1012 ((tc_stmts, ids), lie) <- getLIE $
1013 tcStmts DoExpr (tcDoStmt io_ty io_ret_ty) stmts $
1014 mappM tcLookupId names ;
1015 -- Look up the names right in the middle,
1016 -- where they will all be in scope
1018 -- Simplify the context
1019 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1020 -- checkNoErrs ensures that the plan fails if context redn fails
1022 return (ids, mkHsLet const_binds $
1023 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1028 tcRnExpr just finds the type of an expression
1032 -> InteractiveContext
1035 tcRnExpr hsc_env ictxt rdr_expr
1036 = initTcPrintErrors hsc_env iNTERACTIVE $
1037 setInteractiveContext hsc_env ictxt $ do {
1039 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1042 -- Now typecheck the expression;
1043 -- it might have a rank-2 type (e.g. :t runST)
1044 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1045 ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1046 tcSimplifyInteractive lie_top ;
1047 qtvs' <- mappM zonkQuantifiedTyVar qtvs ;
1049 let { all_expr_ty = mkForAllTys qtvs' $
1050 mkFunTys (map idType dict_ids) $
1052 zonkTcType all_expr_ty
1055 smpl_doc = ptext SLIT("main expression")
1058 tcRnType just finds the kind of a type
1062 -> InteractiveContext
1065 tcRnType hsc_env ictxt rdr_type
1066 = initTcPrintErrors hsc_env iNTERACTIVE $
1067 setInteractiveContext hsc_env ictxt $ do {
1069 rn_type <- rnLHsType doc rdr_type ;
1072 -- Now kind-check the type
1073 (ty', kind) <- kcHsType rn_type ;
1077 doc = ptext SLIT("In GHCi input")
1083 %************************************************************************
1085 More GHCi stuff, to do with browsing and getting info
1087 %************************************************************************
1091 -- ASSUMES that the module is either in the HomePackageTable or is
1092 -- a package module with an interface on disk. If neither of these is
1093 -- true, then the result will be an error indicating the interface
1094 -- could not be found.
1095 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe NameSet)
1096 getModuleExports hsc_env mod
1097 = initTc hsc_env HsSrcFile iNTERACTIVE (tcGetModuleExports mod)
1099 tcGetModuleExports :: Module -> TcM NameSet
1100 tcGetModuleExports mod = do
1101 iface <- load_iface mod
1102 loadOrphanModules (dep_orphs (mi_deps iface))
1103 -- Load any orphan-module interfaces,
1104 -- so their instances are visible
1105 ifaceExportNames (mi_exports iface)
1107 load_iface mod = loadSrcInterface doc mod False {- Not boot iface -}
1109 doc = ptext SLIT("context for compiling statements")
1112 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1113 tcRnLookupRdrName hsc_env rdr_name
1114 = initTcPrintErrors hsc_env iNTERACTIVE $
1115 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1116 lookup_rdr_name rdr_name
1118 lookup_rdr_name rdr_name = do {
1119 -- If the identifier is a constructor (begins with an
1120 -- upper-case letter), then we need to consider both
1121 -- constructor and type class identifiers.
1122 let { rdr_names = dataTcOccs rdr_name } ;
1124 -- results :: [Either Messages Name]
1125 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1127 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1128 -- The successful lookups will be (Just name)
1129 let { (warns_s, good_names) = unzip [ (msgs, name)
1130 | (msgs, Just name) <- results] ;
1131 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1133 -- Fail if nothing good happened, else add warnings
1134 if null good_names then
1135 -- No lookup succeeded, so
1136 -- pick the first error message and report it
1137 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1138 -- while the other is "X is not in scope",
1139 -- we definitely want the former; but we might pick the latter
1140 do { addMessages (head errs_s) ; failM }
1141 else -- Add deprecation warnings
1142 mapM_ addMessages warns_s ;
1148 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1149 tcRnLookupName hsc_env name
1150 = initTcPrintErrors hsc_env iNTERACTIVE $
1151 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1155 tcRnGetInfo :: HscEnv
1157 -> IO (Maybe (TyThing, Fixity, [Instance]))
1159 -- Used to implemnent :info in GHCi
1161 -- Look up a RdrName and return all the TyThings it might be
1162 -- A capitalised RdrName is given to us in the DataName namespace,
1163 -- but we want to treat it as *both* a data constructor
1164 -- *and* as a type or class constructor;
1165 -- hence the call to dataTcOccs, and we return up to two results
1166 tcRnGetInfo hsc_env name
1167 = initTcPrintErrors hsc_env iNTERACTIVE $
1168 let ictxt = hsc_IC hsc_env in
1169 setInteractiveContext hsc_env ictxt $ do
1171 -- Load the interface for all unqualified types and classes
1172 -- That way we will find all the instance declarations
1173 -- (Packages have not orphan modules, and we assume that
1174 -- in the home package all relevant modules are loaded.)
1175 loadUnqualIfaces ictxt
1177 thing <- tcLookupGlobal name
1178 fixity <- lookupFixityRn name
1179 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1180 return (thing, fixity, ispecs)
1183 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1184 -- Filter the instances by the ones whose tycons (or clases resp)
1185 -- are in scope unqualified. Otherwise we list a whole lot too many!
1186 lookupInsts print_unqual (AClass cls)
1187 = do { inst_envs <- tcGetInstEnvs
1189 | ispec <- classInstances inst_envs cls
1190 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1192 lookupInsts print_unqual (ATyCon tc)
1193 = do { eps <- getEps -- Load all instances for all classes that are
1194 -- in the type environment (which are all the ones
1195 -- we've seen in any interface file so far)
1196 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1198 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1199 , let dfun = instanceDFunId ispec
1201 , plausibleDFun print_unqual dfun ] }
1203 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1204 tc_name = tyConName tc
1206 lookupInsts print_unqual other = return []
1208 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1209 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1211 ok name | isBuiltInSyntax name = True
1212 | isExternalName name = print_unqual (nameModule name) (nameOccName name)
1215 loadUnqualIfaces :: InteractiveContext -> TcM ()
1216 -- Load the home module for everything that is in scope unqualified
1217 -- This is so that we can accurately report the instances for
1219 loadUnqualIfaces ictxt
1221 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1223 unqual_mods = [ nameModule name
1224 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1225 let name = gre_name gre,
1226 isTcOcc (nameOccName name), -- Types and classes only
1227 unQualOK gre ] -- In scope unqualified
1228 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1232 %************************************************************************
1236 %************************************************************************
1239 rnDump :: SDoc -> TcRn ()
1240 -- Dump, with a banner, if -ddump-rn
1241 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1243 tcDump :: TcGblEnv -> TcRn ()
1245 = do { dflags <- getDOpts ;
1247 -- Dump short output if -ddump-types or -ddump-tc
1248 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1249 (dumpTcRn short_dump) ;
1251 -- Dump bindings if -ddump-tc
1252 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1255 short_dump = pprTcGblEnv env
1256 full_dump = pprLHsBinds (tcg_binds env)
1257 -- NB: foreign x-d's have undefined's in their types;
1258 -- hence can't show the tc_fords
1261 = do { dflags <- getDOpts ;
1262 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1263 (dumpTcRn (pprModGuts mod_guts)) ;
1265 -- Dump bindings if -ddump-tc
1266 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1268 full_dump = pprCoreBindings (mg_binds mod_guts)
1270 -- It's unpleasant having both pprModGuts and pprModDetails here
1271 pprTcGblEnv :: TcGblEnv -> SDoc
1272 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1273 tcg_insts = dfun_ids,
1275 tcg_imports = imports })
1276 = vcat [ ppr_types dfun_ids type_env
1277 , ppr_insts dfun_ids
1278 , vcat (map ppr rules)
1279 , ppr_gen_tycons (typeEnvTyCons type_env)
1280 , ptext SLIT("Dependent modules:") <+> ppr (moduleEnvElts (imp_dep_mods imports))
1281 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1283 pprModGuts :: ModGuts -> SDoc
1284 pprModGuts (ModGuts { mg_types = type_env,
1286 = vcat [ ppr_types [] type_env,
1290 ppr_types :: [Instance] -> TypeEnv -> SDoc
1291 ppr_types ispecs type_env
1292 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1294 dfun_ids = map instanceDFunId ispecs
1295 ids = [id | id <- typeEnvIds type_env, want_sig id]
1296 want_sig id | opt_PprStyle_Debug = True
1297 | otherwise = isLocalId id &&
1298 isExternalName (idName id) &&
1299 not (id `elem` dfun_ids)
1300 -- isLocalId ignores data constructors, records selectors etc.
1301 -- The isExternalName ignores local dictionary and method bindings
1302 -- that the type checker has invented. Top-level user-defined things
1303 -- have External names.
1305 ppr_insts :: [Instance] -> SDoc
1306 ppr_insts [] = empty
1307 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1309 ppr_sigs :: [Var] -> SDoc
1311 -- Print type signatures; sort by OccName
1312 = vcat (map ppr_sig (sortLe le_sig ids))
1314 le_sig id1 id2 = getOccName id1 <= getOccName id2
1315 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1317 ppr_rules :: [CoreRule] -> SDoc
1318 ppr_rules [] = empty
1319 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1320 nest 4 (pprRules rs),
1323 ppr_gen_tycons [] = empty
1324 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1325 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]