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 HsSyn ( HsModule(..), HsExtCore(..), HsGroup(..), LHsDecl,
30 SpliceDecl(..), HsBind(..), LHsBinds,
31 emptyRdrGroup, emptyRnGroup, appendGroups, plusHsValBinds,
32 nlHsApp, nlHsVar, pprLHsBinds )
33 import RdrHsSyn ( findSplice )
35 import PrelNames ( runMainIOName, rootMainKey, rOOT_MAIN, mAIN,
37 import RdrName ( RdrName, mkRdrUnqual, emptyGlobalRdrEnv )
38 import TcHsSyn ( zonkTopDecls )
39 import TcExpr ( tcInferRho )
41 import TcType ( tidyTopType, tcEqType )
42 import Inst ( showLIE )
43 import InstEnv ( extendInstEnvList, Instance, pprInstances, instanceDFunId )
44 import TcBinds ( tcTopBinds, tcHsBootSigs )
45 import TcDefaults ( tcDefaults )
46 import TcEnv ( tcExtendGlobalValEnv, iDFunId )
47 import TcRules ( tcRules )
48 import TcForeign ( tcForeignImports, tcForeignExports )
49 import TcInstDcls ( tcInstDecls1, tcInstDecls2 )
50 import TcIface ( tcExtCoreBindings, tcHiBootIface )
51 import IfaceSyn ( checkBootDecl, tyThingToIfaceDecl, IfaceExtName(..) )
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 ErrUtils ( Messages, mkDumpDoc, showPass )
63 import Id ( Id, mkExportedLocalId, isLocalId, idName, idType )
66 import UniqFM ( elemUFM, eltsUFM )
67 import OccName ( mkVarOccFS, plusOccEnv )
68 import Name ( Name, NamedThing(..), isExternalName, getSrcLoc, isWiredInName,
69 nameModule, nameOccName, isImplicitName, mkExternalName )
71 import TyCon ( tyConHasGenerics )
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),
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 TypeRep ( TyThing(..) )
103 import RnTypes ( rnLHsType )
104 import Inst ( tcGetInstEnvs )
105 import InstEnv ( classInstances, instEnvElts )
106 import RnExpr ( rnStmts, rnLExpr )
107 import LoadIface ( loadSysInterface )
108 import IfaceEnv ( ifaceExportNames )
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 ( 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 Util ( sortLe )
131 import Bag ( unionBags, snocBag, emptyBag, unitBag, unionManyBags )
133 import Data.Maybe ( isJust, isNothing )
138 %************************************************************************
140 Typecheck and rename a module
142 %************************************************************************
148 -> Bool -- True <=> save renamed syntax
149 -> Located (HsModule RdrName)
150 -> IO (Messages, Maybe TcGblEnv)
152 tcRnModule hsc_env hsc_src save_rn_syntax
153 (L loc (HsModule maybe_mod export_ies
154 import_decls local_decls mod_deprec))
155 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
157 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
158 this_mod = case maybe_mod of
159 Nothing -> mAIN -- 'module M where' is omitted
160 Just (L _ mod) -> mkModule this_pkg mod } ;
163 initTc hsc_env hsc_src this_mod $
166 -- Deal with imports;
167 rn_imports <- rnImports import_decls ;
168 (rdr_env, imports) <- mkRdrEnvAndImports rn_imports ;
170 let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
171 ; dep_mods = imp_dep_mods imports
173 -- We want instance declarations from all home-package
174 -- modules below this one, including boot modules, except
175 -- ourselves. The 'except ourselves' is so that we don't
176 -- get the instances from this module's hs-boot file
177 ; want_instances :: ModuleName -> Bool
178 ; want_instances mod = mod `elemUFM` dep_mods
179 && mod /= moduleName this_mod
180 ; home_insts = hptInstances hsc_env want_instances
183 -- Record boot-file info in the EPS, so that it's
184 -- visible to loadHiBootInterface in tcRnSrcDecls,
185 -- and any other incrementally-performed imports
186 updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
188 -- Update the gbl env
190 gbl { tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
191 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
192 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
193 tcg_rn_imports = if save_rn_syntax then
197 tcg_rn_decls = if save_rn_syntax then
203 traceRn (text "rn1" <+> ppr (imp_dep_mods imports)) ;
204 -- Fail if there are any errors so far
205 -- The error printing (if needed) takes advantage
206 -- of the tcg_env we have now set
209 -- Load any orphan-module interfaces, so that
210 -- their rules and instance decls will be found
211 loadOrphanModules (imp_orphs imports) ;
213 traceRn (text "rn1a") ;
214 -- Rename and type check the declarations
215 tcg_env <- if isHsBoot hsc_src then
216 tcRnHsBootDecls local_decls
218 tcRnSrcDecls local_decls ;
219 setGblEnv tcg_env $ do {
221 traceRn (text "rn3") ;
223 -- Report the use of any deprecated things
224 -- We do this before processsing the export list so
225 -- that we don't bleat about re-exporting a deprecated
226 -- thing (especially via 'module Foo' export item)
227 -- Only uses in the body of the module are complained about
228 reportDeprecations (hsc_dflags hsc_env) tcg_env ;
230 -- Process the export list
231 rn_exports <- rnExports export_ies ;
232 let { liftM2' fn a b = do a' <- a; b' <- b; return (fn a' b') } ;
233 exports <- mkExportNameSet (isJust maybe_mod) (liftM2' (,) rn_exports export_ies) ;
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
260 %************************************************************************
262 Type-checking external-core modules
264 %************************************************************************
267 tcRnExtCore :: HscEnv
269 -> IO (Messages, Maybe ModGuts)
270 -- Nothing => some error occurred
272 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
273 -- The decls are IfaceDecls; all names are original names
274 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
276 initTc hsc_env ExtCoreFile this_mod $ do {
278 let { ldecls = map noLoc decls } ;
280 -- Deal with the type declarations; first bring their stuff
281 -- into scope, then rname them, then type check them
282 tcg_env <- importsFromLocalDecls (mkFakeGroup ldecls) ;
284 setGblEnv tcg_env $ do {
286 rn_decls <- rnTyClDecls ldecls ;
289 -- Dump trace of renaming part
290 rnDump (ppr rn_decls) ;
292 -- Typecheck them all together so that
293 -- any mutually recursive types are done right
294 tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails rn_decls) ;
295 -- Make the new type env available to stuff slurped from interface files
297 setGblEnv tcg_env $ do {
299 -- Now the core bindings
300 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
304 bndrs = bindersOfBinds core_binds ;
305 my_exports = mkNameSet (map idName bndrs) ;
306 -- ToDo: export the data types also?
308 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
310 mod_guts = ModGuts { mg_module = this_mod,
312 mg_usages = [], -- ToDo: compute usage
313 mg_dir_imps = [], -- ??
314 mg_deps = noDependencies, -- ??
315 mg_exports = my_exports,
316 mg_types = final_type_env,
317 mg_insts = tcg_insts tcg_env,
319 mg_binds = core_binds,
322 mg_rdr_env = emptyGlobalRdrEnv,
323 mg_fix_env = emptyFixityEnv,
324 mg_deprecs = NoDeprecs,
328 tcCoreDump mod_guts ;
333 mkFakeGroup decls -- Rather clumsy; lots of unused fields
334 = emptyRdrGroup { hs_tyclds = decls }
338 %************************************************************************
340 Type-checking the top level of a module
342 %************************************************************************
345 tcRnSrcDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
346 -- Returns the variables free in the decls
347 -- Reason: solely to report unused imports and bindings
349 = do { -- Load the hi-boot interface for this module, if any
350 -- We do this now so that the boot_names can be passed
351 -- to tcTyAndClassDecls, because the boot_names are
352 -- automatically considered to be loop breakers
354 boot_iface <- tcHiBootIface mod ;
356 -- Do all the declarations
357 (tc_envs, lie) <- getLIE (tc_rn_src_decls boot_iface decls) ;
359 -- tcSimplifyTop deals with constant or ambiguous InstIds.
360 -- How could there be ambiguous ones? They can only arise if a
361 -- top-level decl falls under the monomorphism
362 -- restriction, and no subsequent decl instantiates its
363 -- type. (Usually, ambiguous type variables are resolved
364 -- during the generalisation step.)
365 traceTc (text "Tc8") ;
366 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
367 -- Setting the global env exposes the instances to tcSimplifyTop
368 -- Setting the local env exposes the local Ids to tcSimplifyTop,
369 -- so that we get better error messages (monomorphism restriction)
371 -- Backsubstitution. This must be done last.
372 -- Even tcSimplifyTop may do some unification.
373 traceTc (text "Tc9") ;
374 let { (tcg_env, _) = tc_envs ;
375 TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
376 tcg_rules = rules, tcg_fords = fords } = tcg_env } ;
379 (bind_ids, binds', fords', rules') <- zonkTopDecls (binds `unionBags` inst_binds)
382 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
383 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
386 tcg_fords = fords' } } ;
388 -- Make the new type env available to stuff slurped from interface files
389 writeMutVar (tcg_type_env_var tcg_env) final_type_env ;
391 -- Compare the hi-boot iface (if any) with the real thing
392 dfun_binds <- checkHiBootIface tcg_env' boot_iface ;
394 return (tcg_env' { tcg_binds = tcg_binds tcg_env' `unionBags` dfun_binds })
397 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
398 -- Loops around dealing with each top level inter-splice group
399 -- in turn, until it's dealt with the entire module
400 tc_rn_src_decls boot_details ds
401 = do { let { (first_group, group_tail) = findSplice ds } ;
402 -- If ds is [] we get ([], Nothing)
404 -- Type check the decls up to, but not including, the first splice
405 tc_envs@(tcg_env,tcl_env) <- tcRnGroup boot_details first_group ;
407 -- Bale out if errors; for example, error recovery when checking
408 -- the RHS of 'main' can mean that 'main' is not in the envt for
409 -- the subsequent checkMain test
414 -- If there is no splice, we're nearly done
416 Nothing -> do { -- Last thing: check for `main'
417 tcg_env <- checkMain ;
418 return (tcg_env, tcl_env)
421 -- If there's a splice, we must carry on
422 Just (SpliceDecl splice_expr, rest_ds) -> do {
424 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
427 -- Rename the splice expression, and get its supporting decls
428 (rn_splice_expr, splice_fvs) <- rnLExpr splice_expr ;
429 failIfErrsM ; -- Don't typecheck if renaming failed
431 -- Execute the splice
432 spliced_decls <- tcSpliceDecls rn_splice_expr ;
434 -- Glue them on the front of the remaining decls and loop
435 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
436 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
441 %************************************************************************
443 Compiling hs-boot source files, and
444 comparing the hi-boot interface with the real thing
446 %************************************************************************
449 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
450 tcRnHsBootDecls decls
451 = do { let { (first_group, group_tail) = findSplice decls }
454 Just stuff -> spliceInHsBootErr stuff
457 -- Rename the declarations
458 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
459 ; setGblEnv tcg_env $ do {
461 -- Todo: check no foreign decls, no rules, no default decls
463 -- Typecheck type/class decls
464 ; traceTc (text "Tc2")
465 ; let tycl_decls = hs_tyclds rn_group
466 ; tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails tycl_decls)
467 ; setGblEnv tcg_env $ do {
469 -- Typecheck instance decls
470 ; traceTc (text "Tc3")
471 ; (tcg_env, inst_infos, _binds) <- tcInstDecls1 tycl_decls (hs_instds rn_group)
472 ; setGblEnv tcg_env $ do {
474 -- Typecheck value declarations
475 ; traceTc (text "Tc5")
476 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
479 -- No simplification or zonking to do
480 ; traceTc (text "Tc7a")
481 ; gbl_env <- getGblEnv
483 -- Make the final type-env
484 -- Include the dfun_ids so that their type sigs get
485 -- are written into the interface file
486 ; let { type_env0 = tcg_type_env gbl_env
487 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
488 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
489 ; dfun_ids = map iDFunId inst_infos }
490 ; return (gbl_env { tcg_type_env = type_env2 })
493 spliceInHsBootErr (SpliceDecl (L loc _), _)
494 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
497 Once we've typechecked the body of the module, we want to compare what
498 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
501 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM (LHsBinds Id)
502 -- Compare the hi-boot file for this module (if there is one)
503 -- with the type environment we've just come up with
504 -- In the common case where there is no hi-boot file, the list
505 -- of boot_names is empty.
507 -- The bindings we return give bindings for the dfuns defined in the
508 -- hs-boot file, such as $fbEqT = $fEqT
511 (TcGblEnv { tcg_insts = local_insts, tcg_type_env = local_type_env })
512 (ModDetails { md_insts = boot_insts, md_types = boot_type_env })
513 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts)) ;
514 ; mapM_ check_one (typeEnvElts boot_type_env)
515 ; dfun_binds <- mapM check_inst boot_insts
516 ; return (unionManyBags dfun_binds) }
521 | Just real_thing <- lookupTypeEnv local_type_env name
522 = do { let boot_decl = tyThingToIfaceDecl ext_nm boot_thing
523 real_decl = tyThingToIfaceDecl ext_nm real_thing
524 ; checkTc (checkBootDecl boot_decl real_decl)
525 (bootMisMatch boot_thing boot_decl real_decl) }
526 -- The easiest way to check compatibility is to convert to
527 -- iface syntax, where we already have good comparison functions
529 = addErrTc (missingBootThing boot_thing)
531 name = getName boot_thing
533 ext_nm name = ExtPkg (nameModule name) (nameOccName name)
534 -- Just enough to compare; no versions etc needed
536 no_check name = isWiredInName name -- No checking for wired-in names. In particular,
537 -- 'error' is handled by a rather gross hack
538 -- (see comments in GHC.Err.hs-boot)
539 || name `elem` dfun_names
540 || isImplicitName name -- Has a parent, which we'll check
542 dfun_names = map getName boot_insts
545 = case [dfun | inst <- local_insts,
546 let dfun = instanceDFunId inst,
547 idType dfun `tcEqType` boot_inst_ty ] of
548 [] -> do { addErrTc (instMisMatch boot_inst); return emptyBag }
549 (dfun:_) -> return (unitBag $ noLoc $ VarBind local_boot_dfun (nlHsVar dfun))
551 boot_dfun = instanceDFunId boot_inst
552 boot_inst_ty = idType boot_dfun
553 local_boot_dfun = mkExportedLocalId (idName boot_dfun) boot_inst_ty
556 missingBootThing thing
557 = ppr thing <+> ptext SLIT("is defined in the hs-boot file, but not in the module")
558 bootMisMatch thing boot_decl real_decl
559 = ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file")
562 2 (ptext SLIT("is defined in the hs-boot file, but not in the module"))
566 %************************************************************************
568 Type-checking the top level of a module
570 %************************************************************************
572 tcRnGroup takes a bunch of top-level source-code declarations, and
574 * gets supporting declarations from interface files
577 * and augments the TcGblEnv with the results
579 In Template Haskell it may be called repeatedly for each group of
580 declarations. It expects there to be an incoming TcGblEnv in the
581 monad; it augments it and returns the new TcGblEnv.
584 tcRnGroup :: ModDetails -> HsGroup RdrName -> TcM (TcGblEnv, TcLclEnv)
585 -- Returns the variables free in the decls, for unused-binding reporting
586 tcRnGroup boot_details decls
587 = do { -- Rename the declarations
588 (tcg_env, rn_decls) <- rnTopSrcDecls decls ;
589 setGblEnv tcg_env $ do {
591 -- Typecheck the declarations
592 tcTopSrcDecls boot_details rn_decls
595 ------------------------------------------------
596 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
598 = do { -- Bring top level binders into scope
599 tcg_env <- importsFromLocalDecls group ;
600 setGblEnv tcg_env $ do {
602 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
604 -- Rename the source decls
605 (tcg_env, rn_decls) <- rnSrcDecls group ;
608 -- save the renamed syntax, if we want it
610 | Just grp <- tcg_rn_decls tcg_env
611 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
615 -- Dump trace of renaming part
616 rnDump (ppr rn_decls) ;
618 return (tcg_env', rn_decls)
621 ------------------------------------------------
622 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
623 tcTopSrcDecls boot_details
624 (HsGroup { hs_tyclds = tycl_decls,
625 hs_instds = inst_decls,
626 hs_fords = foreign_decls,
627 hs_defds = default_decls,
628 hs_ruleds = rule_decls,
629 hs_valds = val_binds })
630 = do { -- Type-check the type and class decls, and all imported decls
631 -- The latter come in via tycl_decls
632 traceTc (text "Tc2") ;
634 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
635 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
636 -- an error we'd better stop now, to avoid a cascade
638 -- Make these type and class decls available to stuff slurped from interface files
639 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
642 setGblEnv tcg_env $ do {
643 -- Source-language instances, including derivings,
644 -- and import the supporting declarations
645 traceTc (text "Tc3") ;
646 (tcg_env, inst_infos, deriv_binds) <- tcInstDecls1 tycl_decls inst_decls ;
647 setGblEnv tcg_env $ do {
649 -- Foreign import declarations next. No zonking necessary
650 -- here; we can tuck them straight into the global environment.
651 traceTc (text "Tc4") ;
652 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
653 tcExtendGlobalValEnv fi_ids $ do {
655 -- Default declarations
656 traceTc (text "Tc4a") ;
657 default_tys <- tcDefaults default_decls ;
658 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
660 -- Value declarations next
661 -- We also typecheck any extra binds that came out
662 -- of the "deriving" process (deriv_binds)
663 traceTc (text "Tc5") ;
664 (tc_val_binds, tcl_env) <- tcTopBinds (val_binds `plusHsValBinds` deriv_binds) ;
665 setLclTypeEnv tcl_env $ do {
667 -- Second pass over class and instance declarations,
668 traceTc (text "Tc6") ;
669 (inst_binds, tcl_env) <- tcInstDecls2 tycl_decls inst_infos ;
670 showLIE (text "after instDecls2") ;
673 -- They need to be zonked, so we return them
674 traceTc (text "Tc7") ;
675 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
678 rules <- tcRules rule_decls ;
681 traceTc (text "Tc7a") ;
682 tcg_env <- getGblEnv ;
683 let { all_binds = tc_val_binds `unionBags`
684 inst_binds `unionBags`
687 -- Extend the GblEnv with the (as yet un-zonked)
688 -- bindings, rules, foreign decls
689 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
690 tcg_rules = tcg_rules tcg_env ++ rules,
691 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
692 return (tcg_env', tcl_env)
697 %************************************************************************
701 %************************************************************************
704 checkMain :: TcM TcGblEnv
705 -- If we are in module Main, check that 'main' is defined.
707 = do { ghc_mode <- getGhcMode ;
708 tcg_env <- getGblEnv ;
710 let { main_mod = mainModIs dflags ;
711 main_fn = case mainFunIs dflags of {
712 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn)) ;
713 Nothing -> main_RDR_Unqual } } ;
715 check_main ghc_mode tcg_env main_mod main_fn
719 check_main ghc_mode tcg_env main_mod main_fn
721 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
725 = addErrCtxt mainCtxt $
726 do { mb_main <- lookupSrcOcc_maybe main_fn
727 -- Check that 'main' is in scope
728 -- It might be imported from another module!
730 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
734 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
735 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
736 -- :Main.main :: IO () = runMainIO main
738 ; (main_expr, ty) <- setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
741 -- The function that the RTS invokes is always :Main.main,
742 -- which we call root_main_id.
743 -- (Because GHC allows the user to have a module not called
744 -- Main as the main module, we can't rely on the main function
745 -- being called "Main.main". That's why root_main_id has a fixed
747 -- We also make root_main_id an implicit Id, by making main_name
748 -- its parent (hence (Just main_name)). That has the effect
749 -- of preventing its type and unfolding from getting out into
750 -- the interface file. Otherwise we can end up with two defns
751 -- for 'main' in the interface file!
753 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
754 (mkVarOccFS FSLIT("main"))
755 (Just main_name) (getSrcLoc main_name)
756 ; root_main_id = mkExportedLocalId root_main_name ty
757 ; main_bind = noLoc (VarBind root_main_id main_expr) }
759 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
761 tcg_dus = tcg_dus tcg_env
762 `plusDU` usesOnly (unitFV main_name)
763 -- Record the use of 'main', so that we don't
764 -- complain about it being defined but not used
768 mod = tcg_mod tcg_env
770 complain_no_main | ghc_mode == Interactive = return ()
771 | otherwise = failWithTc noMainMsg
772 -- In interactive mode, don't worry about the absence of 'main'
773 -- In other modes, fail altogether, so that we don't go on
774 -- and complain a second time when processing the export list.
776 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
777 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
778 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
781 %*********************************************************
785 %*********************************************************
789 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
790 setInteractiveContext hsc_env icxt thing_inside
792 -- Initialise the tcg_inst_env with instances
793 -- from all home modules. This mimics the more selective
794 -- call to hptInstances in tcRnModule
795 dfuns = hptInstances hsc_env (\mod -> True)
797 updGblEnv (\env -> env {
798 tcg_rdr_env = ic_rn_gbl_env icxt,
799 tcg_type_env = ic_type_env icxt,
800 tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
802 updLclEnv (\env -> env { tcl_rdr = ic_rn_local_env icxt }) $
804 do { traceTc (text "setIC" <+> ppr (ic_type_env icxt))
811 -> InteractiveContext
813 -> IO (Maybe (InteractiveContext, [Name], LHsExpr Id))
814 -- The returned [Name] is the same as the input except for
815 -- ExprStmt, in which case the returned [Name] is [itName]
817 -- The returned TypecheckedHsExpr is of type IO [ () ],
818 -- a list of the bound values, coerced to ().
820 tcRnStmt hsc_env ictxt rdr_stmt
821 = initTcPrintErrors hsc_env iNTERACTIVE $
822 setInteractiveContext hsc_env ictxt $ do {
824 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
825 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
826 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
829 -- The real work is done here
830 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
831 zonked_expr <- zonkTopLExpr tc_expr ;
832 zonked_ids <- zonkTopBndrs bound_ids ;
834 -- None of the Ids should be of unboxed type, because we
835 -- cast them all to HValues in the end!
836 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
838 traceTc (text "tcs 1") ;
839 let { -- (a) Make all the bound ids "global" ids, now that
840 -- they're notionally top-level bindings. This is
841 -- important: otherwise when we come to compile an expression
842 -- using these ids later, the byte code generator will consider
843 -- the occurrences to be free rather than global.
845 -- (b) Tidy their types; this is important, because :info may
846 -- ask to look at them, and :info expects the things it looks
847 -- up to have tidy types
848 global_ids = map globaliseAndTidy zonked_ids ;
850 -- Update the interactive context
851 rn_env = ic_rn_local_env ictxt ;
852 type_env = ic_type_env ictxt ;
854 bound_names = map idName global_ids ;
855 new_rn_env = extendLocalRdrEnv rn_env bound_names ;
857 -- Remove any shadowed bindings from the type_env;
858 -- they are inaccessible but might, I suppose, cause
859 -- a space leak if we leave them there
860 shadowed = [ n | name <- bound_names,
861 let rdr_name = mkRdrUnqual (nameOccName name),
862 Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ;
864 filtered_type_env = delListFromNameEnv type_env shadowed ;
865 new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ;
867 new_ic = ictxt { ic_rn_local_env = new_rn_env,
868 ic_type_env = new_type_env }
871 dumpOptTcRn Opt_D_dump_tc
872 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
873 text "Typechecked expr" <+> ppr zonked_expr]) ;
875 returnM (new_ic, bound_names, zonked_expr)
878 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
879 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
881 globaliseAndTidy :: Id -> Id
883 -- Give the Id a Global Name, and tidy its type
884 = setIdType (globaliseId VanillaGlobal id) tidy_type
886 tidy_type = tidyTopType (idType id)
889 Here is the grand plan, implemented in tcUserStmt
891 What you type The IO [HValue] that hscStmt returns
892 ------------- ------------------------------------
893 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
896 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
899 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
900 [NB: result not printed] bindings: [it]
902 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
903 result showable) bindings: [it]
905 expr (of non-IO type,
906 result not showable) ==> error
910 ---------------------------
911 type PlanResult = ([Id], LHsExpr Id)
912 type Plan = TcM PlanResult
914 runPlans :: [Plan] -> TcM PlanResult
915 -- Try the plans in order. If one fails (by raising an exn), try the next.
916 -- If one succeeds, take it.
917 runPlans [] = panic "runPlans"
919 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
922 mkPlan :: LStmt Name -> TcM PlanResult
923 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
924 = do { uniq <- newUnique -- is treated very specially
925 ; let fresh_it = itName uniq
926 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
927 matches = [mkMatch [] expr emptyLocalBinds]
928 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
929 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
930 (HsVar bindIOName) noSyntaxExpr
931 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
932 (HsVar thenIOName) placeHolderType
935 -- [it <- e; print it] but not if it::()
937 -- [let it = e; print it]
938 ; runPlans [ -- Plan A
939 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
940 ; it_ty <- zonkTcType (idType it_id)
941 ; ifM (isUnitTy it_ty) failM
944 -- Plan B; a naked bind statment
945 tcGhciStmts [bind_stmt],
947 -- Plan C; check that the let-binding is typeable all by itself.
948 -- If not, fail; if so, try to print it.
949 -- The two-step process avoids getting two errors: one from
950 -- the expression itself, and one from the 'print it' part
951 -- This two-step story is very clunky, alas
952 do { checkNoErrs (tcGhciStmts [let_stmt])
953 --- checkNoErrs defeats the error recovery of let-bindings
954 ; tcGhciStmts [let_stmt, print_it] }
957 mkPlan stmt@(L loc (BindStmt {}))
958 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
959 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
960 (HsVar thenIOName) placeHolderType
962 -- [stmt; print v] but not if v::()
964 ; runPlans [do { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
965 ; v_ty <- zonkTcType (idType v_id)
966 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
974 ---------------------------
975 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
977 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
978 ret_id <- tcLookupId returnIOName ; -- return @ IO
980 io_ty = mkTyConApp ioTyCon [] ;
981 ret_ty = mkListTy unitTy ;
982 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
984 names = map unLoc (collectLStmtsBinders stmts) ;
986 -- mk_return builds the expression
987 -- returnIO @ [()] [coerce () x, .., coerce () z]
989 -- Despite the inconvenience of building the type applications etc,
990 -- this *has* to be done in type-annotated post-typecheck form
991 -- because we are going to return a list of *polymorphic* values
992 -- coerced to type (). If we built a *source* stmt
993 -- return [coerce x, ..., coerce z]
994 -- then the type checker would instantiate x..z, and we wouldn't
995 -- get their *polymorphic* values. (And we'd get ambiguity errs
996 -- if they were overloaded, since they aren't applied to anything.)
997 mk_return ids = nlHsApp (noLoc $ TyApp (nlHsVar ret_id) [ret_ty])
998 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
999 mk_item id = nlHsApp (noLoc $ TyApp (nlHsVar unsafeCoerceId) [idType id, unitTy])
1003 -- OK, we're ready to typecheck the stmts
1004 traceTc (text "tcs 2") ;
1005 ((tc_stmts, ids), lie) <- getLIE $
1006 tcStmts DoExpr (tcDoStmt io_ty) stmts io_ret_ty $ \ _ ->
1007 mappM tcLookupId names ;
1008 -- Look up the names right in the middle,
1009 -- where they will all be in scope
1011 -- Simplify the context
1012 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1013 -- checkNoErrs ensures that the plan fails if context redn fails
1015 return (ids, mkHsDictLet const_binds $
1016 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1021 tcRnExpr just finds the type of an expression
1025 -> InteractiveContext
1028 tcRnExpr hsc_env ictxt rdr_expr
1029 = initTcPrintErrors hsc_env iNTERACTIVE $
1030 setInteractiveContext hsc_env ictxt $ do {
1032 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1035 -- Now typecheck the expression;
1036 -- it might have a rank-2 type (e.g. :t runST)
1037 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1038 ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1039 tcSimplifyInteractive lie_top ;
1040 qtvs' <- mappM zonkQuantifiedTyVar qtvs ;
1042 let { all_expr_ty = mkForAllTys qtvs' $
1043 mkFunTys (map idType dict_ids) $
1045 zonkTcType all_expr_ty
1048 smpl_doc = ptext SLIT("main expression")
1051 tcRnType just finds the kind of a type
1055 -> InteractiveContext
1058 tcRnType hsc_env ictxt rdr_type
1059 = initTcPrintErrors hsc_env iNTERACTIVE $
1060 setInteractiveContext hsc_env ictxt $ do {
1062 rn_type <- rnLHsType doc rdr_type ;
1065 -- Now kind-check the type
1066 (ty', kind) <- kcHsType rn_type ;
1070 doc = ptext SLIT("In GHCi input")
1076 %************************************************************************
1078 More GHCi stuff, to do with browsing and getting info
1080 %************************************************************************
1084 -- ASSUMES that the module is either in the HomePackageTable or is
1085 -- a package module with an interface on disk. If neither of these is
1086 -- true, then the result will be an error indicating the interface
1087 -- could not be found.
1088 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe NameSet)
1089 getModuleExports hsc_env mod
1090 = initTc hsc_env HsSrcFile iNTERACTIVE (tcGetModuleExports mod)
1092 tcGetModuleExports :: Module -> TcM NameSet
1093 tcGetModuleExports mod = do
1094 let doc = ptext SLIT("context for compiling statements")
1095 iface <- initIfaceTcRn $ loadSysInterface doc mod
1096 loadOrphanModules (dep_orphs (mi_deps iface))
1097 -- Load any orphan-module interfaces,
1098 -- so their instances are visible
1099 ifaceExportNames (mi_exports iface)
1101 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1102 tcRnLookupRdrName hsc_env rdr_name
1103 = initTcPrintErrors hsc_env iNTERACTIVE $
1104 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1105 lookup_rdr_name rdr_name
1107 lookup_rdr_name rdr_name = do {
1108 -- If the identifier is a constructor (begins with an
1109 -- upper-case letter), then we need to consider both
1110 -- constructor and type class identifiers.
1111 let { rdr_names = dataTcOccs rdr_name } ;
1113 -- results :: [Either Messages Name]
1114 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1116 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1117 -- The successful lookups will be (Just name)
1118 let { (warns_s, good_names) = unzip [ (msgs, name)
1119 | (msgs, Just name) <- results] ;
1120 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1122 -- Fail if nothing good happened, else add warnings
1123 if null good_names then
1124 -- No lookup succeeded, so
1125 -- pick the first error message and report it
1126 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1127 -- while the other is "X is not in scope",
1128 -- we definitely want the former; but we might pick the latter
1129 do { addMessages (head errs_s) ; failM }
1130 else -- Add deprecation warnings
1131 mapM_ addMessages warns_s ;
1137 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1138 tcRnLookupName hsc_env name
1139 = initTcPrintErrors hsc_env iNTERACTIVE $
1140 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1144 tcRnGetInfo :: HscEnv
1146 -> IO (Maybe (TyThing, Fixity, [Instance]))
1148 -- Used to implemnent :info in GHCi
1150 -- Look up a RdrName and return all the TyThings it might be
1151 -- A capitalised RdrName is given to us in the DataName namespace,
1152 -- but we want to treat it as *both* a data constructor
1153 -- *and* as a type or class constructor;
1154 -- hence the call to dataTcOccs, and we return up to two results
1155 tcRnGetInfo hsc_env name
1156 = initTcPrintErrors hsc_env iNTERACTIVE $
1157 let ictxt = hsc_IC hsc_env in
1158 setInteractiveContext hsc_env ictxt $ do
1160 -- Load the interface for all unqualified types and classes
1161 -- That way we will find all the instance declarations
1162 -- (Packages have not orphan modules, and we assume that
1163 -- in the home package all relevant modules are loaded.)
1164 loadUnqualIfaces ictxt
1166 thing <- tcLookupGlobal name
1167 fixity <- lookupFixityRn name
1168 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1169 return (thing, fixity, ispecs)
1172 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1173 -- Filter the instances by the ones whose tycons (or clases resp)
1174 -- are in scope unqualified. Otherwise we list a whole lot too many!
1175 lookupInsts print_unqual (AClass cls)
1176 = do { inst_envs <- tcGetInstEnvs
1178 | ispec <- classInstances inst_envs cls
1179 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1181 lookupInsts print_unqual (ATyCon tc)
1182 = do { eps <- getEps -- Load all instances for all classes that are
1183 -- in the type environment (which are all the ones
1184 -- we've seen in any interface file so far)
1185 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1187 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1188 , let dfun = instanceDFunId ispec
1190 , plausibleDFun print_unqual dfun ] }
1192 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1193 tc_name = tyConName tc
1195 lookupInsts print_unqual other = return []
1197 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1198 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1200 ok name | isBuiltInSyntax name = True
1201 | isExternalName name =
1202 isNothing $ fst print_unqual (nameModule name)
1206 loadUnqualIfaces :: InteractiveContext -> TcM ()
1207 -- Load the home module for everything that is in scope unqualified
1208 -- This is so that we can accurately report the instances for
1210 loadUnqualIfaces ictxt
1212 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1214 unqual_mods = [ nameModule name
1215 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1216 let name = gre_name gre,
1217 not (isInternalName name),
1218 isTcOcc (nameOccName name), -- Types and classes only
1219 unQualOK gre ] -- In scope unqualified
1220 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1224 %************************************************************************
1228 %************************************************************************
1231 rnDump :: SDoc -> TcRn ()
1232 -- Dump, with a banner, if -ddump-rn
1233 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1235 tcDump :: TcGblEnv -> TcRn ()
1237 = do { dflags <- getDOpts ;
1239 -- Dump short output if -ddump-types or -ddump-tc
1240 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1241 (dumpTcRn short_dump) ;
1243 -- Dump bindings if -ddump-tc
1244 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1247 short_dump = pprTcGblEnv env
1248 full_dump = pprLHsBinds (tcg_binds env)
1249 -- NB: foreign x-d's have undefined's in their types;
1250 -- hence can't show the tc_fords
1253 = do { dflags <- getDOpts ;
1254 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1255 (dumpTcRn (pprModGuts mod_guts)) ;
1257 -- Dump bindings if -ddump-tc
1258 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1260 full_dump = pprCoreBindings (mg_binds mod_guts)
1262 -- It's unpleasant having both pprModGuts and pprModDetails here
1263 pprTcGblEnv :: TcGblEnv -> SDoc
1264 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1265 tcg_insts = dfun_ids,
1267 tcg_imports = imports })
1268 = vcat [ ppr_types dfun_ids type_env
1269 , ppr_insts dfun_ids
1270 , vcat (map ppr rules)
1271 , ppr_gen_tycons (typeEnvTyCons type_env)
1272 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1273 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1275 pprModGuts :: ModGuts -> SDoc
1276 pprModGuts (ModGuts { mg_types = type_env,
1278 = vcat [ ppr_types [] type_env,
1282 ppr_types :: [Instance] -> TypeEnv -> SDoc
1283 ppr_types ispecs type_env
1284 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1286 dfun_ids = map instanceDFunId ispecs
1287 ids = [id | id <- typeEnvIds type_env, want_sig id]
1288 want_sig id | opt_PprStyle_Debug = True
1289 | otherwise = isLocalId id &&
1290 isExternalName (idName id) &&
1291 not (id `elem` dfun_ids)
1292 -- isLocalId ignores data constructors, records selectors etc.
1293 -- The isExternalName ignores local dictionary and method bindings
1294 -- that the type checker has invented. Top-level user-defined things
1295 -- have External names.
1297 ppr_insts :: [Instance] -> SDoc
1298 ppr_insts [] = empty
1299 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1301 ppr_sigs :: [Var] -> SDoc
1303 -- Print type signatures; sort by OccName
1304 = vcat (map ppr_sig (sortLe le_sig ids))
1306 le_sig id1 id2 = getOccName id1 <= getOccName id2
1307 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1309 ppr_rules :: [CoreRule] -> SDoc
1310 ppr_rules [] = empty
1311 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1312 nest 4 (pprRules rs),
1315 ppr_gen_tycons [] = empty
1316 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1317 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]