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 )
127 import Data.Maybe ( isNothing )
130 import FastString ( mkFastString )
131 import Util ( sortLe )
132 import Bag ( unionBags, snocBag, emptyBag, unitBag, unionManyBags )
134 import Data.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_pkg = thisPackage (hsc_dflags hsc_env) ;
159 this_mod = case maybe_mod of
160 Nothing -> mAIN -- 'module M where' is omitted
161 Just (L _ mod) -> mkModule this_pkg mod } ;
164 initTc hsc_env hsc_src this_mod $
167 -- Deal with imports;
168 rn_imports <- rnImports import_decls ;
169 (rdr_env, imports) <- mkRdrEnvAndImports rn_imports ;
171 let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
172 ; dep_mods = imp_dep_mods imports
174 -- We want instance declarations from all home-package
175 -- modules below this one, including boot modules, except
176 -- ourselves. The 'except ourselves' is so that we don't
177 -- get the instances from this module's hs-boot file
178 ; want_instances :: ModuleName -> Bool
179 ; want_instances mod = mod `elemUFM` dep_mods
180 && mod /= moduleName this_mod
181 ; home_insts = hptInstances hsc_env want_instances
184 -- Record boot-file info in the EPS, so that it's
185 -- visible to loadHiBootInterface in tcRnSrcDecls,
186 -- and any other incrementally-performed imports
187 updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
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 (hsc_dflags hsc_env) 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
261 %************************************************************************
263 Type-checking external-core modules
265 %************************************************************************
268 tcRnExtCore :: HscEnv
270 -> IO (Messages, Maybe ModGuts)
271 -- Nothing => some error occurred
273 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
274 -- The decls are IfaceDecls; all names are original names
275 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
277 initTc hsc_env ExtCoreFile this_mod $ do {
279 let { ldecls = map noLoc decls } ;
281 -- Deal with the type declarations; first bring their stuff
282 -- into scope, then rname them, then type check them
283 tcg_env <- importsFromLocalDecls (mkFakeGroup ldecls) ;
285 setGblEnv tcg_env $ do {
287 rn_decls <- rnTyClDecls ldecls ;
290 -- Dump trace of renaming part
291 rnDump (ppr rn_decls) ;
293 -- Typecheck them all together so that
294 -- any mutually recursive types are done right
295 tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails rn_decls) ;
296 -- Make the new type env available to stuff slurped from interface files
298 setGblEnv tcg_env $ do {
300 -- Now the core bindings
301 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
305 bndrs = bindersOfBinds core_binds ;
306 my_exports = mkNameSet (map idName bndrs) ;
307 -- ToDo: export the data types also?
309 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
311 mod_guts = ModGuts { mg_module = this_mod,
313 mg_usages = [], -- ToDo: compute usage
314 mg_dir_imps = [], -- ??
315 mg_deps = noDependencies, -- ??
316 mg_exports = my_exports,
317 mg_types = final_type_env,
318 mg_insts = tcg_insts tcg_env,
320 mg_binds = core_binds,
323 mg_rdr_env = emptyGlobalRdrEnv,
324 mg_fix_env = emptyFixityEnv,
325 mg_deprecs = NoDeprecs,
329 tcCoreDump mod_guts ;
334 mkFakeGroup decls -- Rather clumsy; lots of unused fields
335 = emptyRdrGroup { hs_tyclds = decls }
339 %************************************************************************
341 Type-checking the top level of a module
343 %************************************************************************
346 tcRnSrcDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
347 -- Returns the variables free in the decls
348 -- Reason: solely to report unused imports and bindings
350 = do { -- Load the hi-boot interface for this module, if any
351 -- We do this now so that the boot_names can be passed
352 -- to tcTyAndClassDecls, because the boot_names are
353 -- automatically considered to be loop breakers
355 boot_iface <- tcHiBootIface mod ;
357 -- Do all the declarations
358 (tc_envs, lie) <- getLIE (tc_rn_src_decls boot_iface decls) ;
360 -- tcSimplifyTop deals with constant or ambiguous InstIds.
361 -- How could there be ambiguous ones? They can only arise if a
362 -- top-level decl falls under the monomorphism
363 -- restriction, and no subsequent decl instantiates its
364 -- type. (Usually, ambiguous type variables are resolved
365 -- during the generalisation step.)
366 traceTc (text "Tc8") ;
367 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
368 -- Setting the global env exposes the instances to tcSimplifyTop
369 -- Setting the local env exposes the local Ids to tcSimplifyTop,
370 -- so that we get better error messages (monomorphism restriction)
372 -- Backsubstitution. This must be done last.
373 -- Even tcSimplifyTop may do some unification.
374 traceTc (text "Tc9") ;
375 let { (tcg_env, _) = tc_envs ;
376 TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
377 tcg_rules = rules, tcg_fords = fords } = tcg_env } ;
380 (bind_ids, binds', fords', rules') <- zonkTopDecls (binds `unionBags` inst_binds)
383 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
384 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
387 tcg_fords = fords' } } ;
389 -- Make the new type env available to stuff slurped from interface files
390 writeMutVar (tcg_type_env_var tcg_env) final_type_env ;
392 -- Compare the hi-boot iface (if any) with the real thing
393 dfun_binds <- checkHiBootIface tcg_env' boot_iface ;
395 return (tcg_env' { tcg_binds = tcg_binds tcg_env' `unionBags` dfun_binds })
398 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
399 -- Loops around dealing with each top level inter-splice group
400 -- in turn, until it's dealt with the entire module
401 tc_rn_src_decls boot_details ds
402 = do { let { (first_group, group_tail) = findSplice ds } ;
403 -- If ds is [] we get ([], Nothing)
405 -- Type check the decls up to, but not including, the first splice
406 tc_envs@(tcg_env,tcl_env) <- tcRnGroup boot_details first_group ;
408 -- Bale out if errors; for example, error recovery when checking
409 -- the RHS of 'main' can mean that 'main' is not in the envt for
410 -- the subsequent checkMain test
415 -- If there is no splice, we're nearly done
417 Nothing -> do { -- Last thing: check for `main'
418 tcg_env <- checkMain ;
419 return (tcg_env, tcl_env)
422 -- If there's a splice, we must carry on
423 Just (SpliceDecl splice_expr, rest_ds) -> do {
425 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
428 -- Rename the splice expression, and get its supporting decls
429 (rn_splice_expr, splice_fvs) <- rnLExpr splice_expr ;
430 failIfErrsM ; -- Don't typecheck if renaming failed
431 rnDump (ppr rn_splice_expr) ;
433 -- Execute the splice
434 spliced_decls <- tcSpliceDecls rn_splice_expr ;
436 -- Glue them on the front of the remaining decls and loop
437 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
438 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
443 %************************************************************************
445 Compiling hs-boot source files, and
446 comparing the hi-boot interface with the real thing
448 %************************************************************************
451 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
452 tcRnHsBootDecls decls
453 = do { let { (first_group, group_tail) = findSplice decls }
456 Just stuff -> spliceInHsBootErr stuff
459 -- Rename the declarations
460 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
461 ; setGblEnv tcg_env $ do {
463 -- Todo: check no foreign decls, no rules, no default decls
465 -- Typecheck type/class decls
466 ; traceTc (text "Tc2")
467 ; let tycl_decls = hs_tyclds rn_group
468 ; tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails tycl_decls)
469 ; setGblEnv tcg_env $ do {
471 -- Typecheck instance decls
472 ; traceTc (text "Tc3")
473 ; (tcg_env, inst_infos, _binds) <- tcInstDecls1 tycl_decls (hs_instds rn_group)
474 ; setGblEnv tcg_env $ do {
476 -- Typecheck value declarations
477 ; traceTc (text "Tc5")
478 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
481 -- No simplification or zonking to do
482 ; traceTc (text "Tc7a")
483 ; gbl_env <- getGblEnv
485 -- Make the final type-env
486 -- Include the dfun_ids so that their type sigs get
487 -- are written into the interface file
488 ; let { type_env0 = tcg_type_env gbl_env
489 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
490 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
491 ; dfun_ids = map iDFunId inst_infos }
492 ; return (gbl_env { tcg_type_env = type_env2 })
495 spliceInHsBootErr (SpliceDecl (L loc _), _)
496 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
499 Once we've typechecked the body of the module, we want to compare what
500 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
503 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM (LHsBinds Id)
504 -- Compare the hi-boot file for this module (if there is one)
505 -- with the type environment we've just come up with
506 -- In the common case where there is no hi-boot file, the list
507 -- of boot_names is empty.
509 -- The bindings we return give bindings for the dfuns defined in the
510 -- hs-boot file, such as $fbEqT = $fEqT
513 (TcGblEnv { tcg_insts = local_insts, tcg_type_env = local_type_env })
514 (ModDetails { md_insts = boot_insts, md_types = boot_type_env })
515 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts)) ;
516 ; mapM_ check_one (typeEnvElts boot_type_env)
517 ; dfun_binds <- mapM check_inst boot_insts
518 ; return (unionManyBags dfun_binds) }
523 | Just real_thing <- lookupTypeEnv local_type_env name
524 = do { let boot_decl = tyThingToIfaceDecl ext_nm boot_thing
525 real_decl = tyThingToIfaceDecl ext_nm real_thing
526 ; checkTc (checkBootDecl boot_decl real_decl)
527 (bootMisMatch boot_thing boot_decl real_decl) }
528 -- The easiest way to check compatibility is to convert to
529 -- iface syntax, where we already have good comparison functions
531 = addErrTc (missingBootThing boot_thing)
533 name = getName boot_thing
535 ext_nm name = ExtPkg (nameModule name) (nameOccName name)
536 -- Just enough to compare; no versions etc needed
538 no_check name = isWiredInName name -- No checking for wired-in names. In particular,
539 -- 'error' is handled by a rather gross hack
540 -- (see comments in GHC.Err.hs-boot)
541 || name `elem` dfun_names
542 || isImplicitName name -- Has a parent, which we'll check
544 dfun_names = map getName boot_insts
547 = case [dfun | inst <- local_insts,
548 let dfun = instanceDFunId inst,
549 idType dfun `tcEqType` boot_inst_ty ] of
550 [] -> do { addErrTc (instMisMatch boot_inst); return emptyBag }
551 (dfun:_) -> return (unitBag $ noLoc $ VarBind local_boot_dfun (nlHsVar dfun))
553 boot_dfun = instanceDFunId boot_inst
554 boot_inst_ty = idType boot_dfun
555 local_boot_dfun = mkExportedLocalId (idName boot_dfun) boot_inst_ty
558 missingBootThing thing
559 = ppr thing <+> ptext SLIT("is defined in the hs-boot file, but not in the module")
560 bootMisMatch thing boot_decl real_decl
561 = ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file")
564 2 (ptext SLIT("is defined in the hs-boot file, but not in the module"))
568 %************************************************************************
570 Type-checking the top level of a module
572 %************************************************************************
574 tcRnGroup takes a bunch of top-level source-code declarations, and
576 * gets supporting declarations from interface files
579 * and augments the TcGblEnv with the results
581 In Template Haskell it may be called repeatedly for each group of
582 declarations. It expects there to be an incoming TcGblEnv in the
583 monad; it augments it and returns the new TcGblEnv.
586 tcRnGroup :: ModDetails -> HsGroup RdrName -> TcM (TcGblEnv, TcLclEnv)
587 -- Returns the variables free in the decls, for unused-binding reporting
588 tcRnGroup boot_details decls
589 = do { -- Rename the declarations
590 (tcg_env, rn_decls) <- rnTopSrcDecls decls ;
591 setGblEnv tcg_env $ do {
593 -- Typecheck the declarations
594 tcTopSrcDecls boot_details rn_decls
597 ------------------------------------------------
598 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
600 = do { -- Bring top level binders into scope
601 tcg_env <- importsFromLocalDecls group ;
602 setGblEnv tcg_env $ do {
604 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
606 -- Rename the source decls
607 (tcg_env, rn_decls) <- rnSrcDecls group ;
610 -- save the renamed syntax, if we want it
612 | Just grp <- tcg_rn_decls tcg_env
613 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
617 -- Dump trace of renaming part
618 rnDump (ppr rn_decls) ;
620 return (tcg_env', rn_decls)
623 ------------------------------------------------
624 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
625 tcTopSrcDecls boot_details
626 (HsGroup { hs_tyclds = tycl_decls,
627 hs_instds = inst_decls,
628 hs_fords = foreign_decls,
629 hs_defds = default_decls,
630 hs_ruleds = rule_decls,
631 hs_valds = val_binds })
632 = do { -- Type-check the type and class decls, and all imported decls
633 -- The latter come in via tycl_decls
634 traceTc (text "Tc2") ;
636 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
637 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
638 -- an error we'd better stop now, to avoid a cascade
640 -- Make these type and class decls available to stuff slurped from interface files
641 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
644 setGblEnv tcg_env $ do {
645 -- Source-language instances, including derivings,
646 -- and import the supporting declarations
647 traceTc (text "Tc3") ;
648 (tcg_env, inst_infos, deriv_binds) <- tcInstDecls1 tycl_decls inst_decls ;
649 setGblEnv tcg_env $ do {
651 -- Foreign import declarations next. No zonking necessary
652 -- here; we can tuck them straight into the global environment.
653 traceTc (text "Tc4") ;
654 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
655 tcExtendGlobalValEnv fi_ids $ do {
657 -- Default declarations
658 traceTc (text "Tc4a") ;
659 default_tys <- tcDefaults default_decls ;
660 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
662 -- Value declarations next
663 -- We also typecheck any extra binds that came out
664 -- of the "deriving" process (deriv_binds)
665 traceTc (text "Tc5") ;
666 (tc_val_binds, tcl_env) <- tcTopBinds (val_binds `plusHsValBinds` deriv_binds) ;
667 setLclTypeEnv tcl_env $ do {
669 -- Second pass over class and instance declarations,
670 traceTc (text "Tc6") ;
671 (inst_binds, tcl_env) <- tcInstDecls2 tycl_decls inst_infos ;
672 showLIE (text "after instDecls2") ;
675 -- They need to be zonked, so we return them
676 traceTc (text "Tc7") ;
677 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
680 rules <- tcRules rule_decls ;
683 traceTc (text "Tc7a") ;
684 tcg_env <- getGblEnv ;
685 let { all_binds = tc_val_binds `unionBags`
686 inst_binds `unionBags`
689 -- Extend the GblEnv with the (as yet un-zonked)
690 -- bindings, rules, foreign decls
691 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
692 tcg_rules = tcg_rules tcg_env ++ rules,
693 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
694 return (tcg_env', tcl_env)
699 %************************************************************************
703 %************************************************************************
706 checkMain :: TcM TcGblEnv
707 -- If we are in module Main, check that 'main' is defined.
709 = do { ghc_mode <- getGhcMode ;
710 tcg_env <- getGblEnv ;
712 let { main_mod = mainModIs dflags ;
713 main_fn = case mainFunIs dflags of {
714 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn)) ;
715 Nothing -> main_RDR_Unqual } } ;
717 check_main ghc_mode tcg_env main_mod main_fn
721 check_main ghc_mode tcg_env main_mod main_fn
723 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
727 = addErrCtxt mainCtxt $
728 do { mb_main <- lookupSrcOcc_maybe main_fn
729 -- Check that 'main' is in scope
730 -- It might be imported from another module!
732 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
736 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
737 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
738 -- :Main.main :: IO () = runMainIO main
740 ; (main_expr, ty) <- setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
743 -- The function that the RTS invokes is always :Main.main,
744 -- which we call root_main_id.
745 -- (Because GHC allows the user to have a module not called
746 -- Main as the main module, we can't rely on the main function
747 -- being called "Main.main". That's why root_main_id has a fixed
749 -- We also make root_main_id an implicit Id, by making main_name
750 -- its parent (hence (Just main_name)). That has the effect
751 -- of preventing its type and unfolding from getting out into
752 -- the interface file. Otherwise we can end up with two defns
753 -- for 'main' in the interface file!
755 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
756 (mkVarOccFS FSLIT("main"))
757 (Just main_name) (getSrcLoc main_name)
758 ; root_main_id = mkExportedLocalId root_main_name ty
759 ; main_bind = noLoc (VarBind root_main_id main_expr) }
761 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
763 tcg_dus = tcg_dus tcg_env
764 `plusDU` usesOnly (unitFV main_name)
765 -- Record the use of 'main', so that we don't
766 -- complain about it being defined but not used
770 mod = tcg_mod tcg_env
772 complain_no_main | ghc_mode == Interactive = return ()
773 | otherwise = failWithTc noMainMsg
774 -- In interactive mode, don't worry about the absence of 'main'
775 -- In other modes, fail altogether, so that we don't go on
776 -- and complain a second time when processing the export list.
778 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
779 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
780 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
783 %*********************************************************
787 %*********************************************************
791 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
792 setInteractiveContext hsc_env icxt thing_inside
794 -- Initialise the tcg_inst_env with instances
795 -- from all home modules. This mimics the more selective
796 -- call to hptInstances in tcRnModule
797 dfuns = hptInstances hsc_env (\mod -> True)
799 updGblEnv (\env -> env {
800 tcg_rdr_env = ic_rn_gbl_env icxt,
801 tcg_type_env = ic_type_env icxt,
802 tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
804 updLclEnv (\env -> env { tcl_rdr = ic_rn_local_env icxt }) $
806 do { traceTc (text "setIC" <+> ppr (ic_type_env icxt))
813 -> InteractiveContext
815 -> IO (Maybe (InteractiveContext, [Name], LHsExpr Id))
816 -- The returned [Name] is the same as the input except for
817 -- ExprStmt, in which case the returned [Name] is [itName]
819 -- The returned TypecheckedHsExpr is of type IO [ () ],
820 -- a list of the bound values, coerced to ().
822 tcRnStmt hsc_env ictxt rdr_stmt
823 = initTcPrintErrors hsc_env iNTERACTIVE $
824 setInteractiveContext hsc_env ictxt $ do {
826 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
827 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
828 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
831 -- The real work is done here
832 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
833 zonked_expr <- zonkTopLExpr tc_expr ;
834 zonked_ids <- zonkTopBndrs bound_ids ;
836 -- None of the Ids should be of unboxed type, because we
837 -- cast them all to HValues in the end!
838 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
840 traceTc (text "tcs 1") ;
841 let { -- (a) Make all the bound ids "global" ids, now that
842 -- they're notionally top-level bindings. This is
843 -- important: otherwise when we come to compile an expression
844 -- using these ids later, the byte code generator will consider
845 -- the occurrences to be free rather than global.
847 -- (b) Tidy their types; this is important, because :info may
848 -- ask to look at them, and :info expects the things it looks
849 -- up to have tidy types
850 global_ids = map globaliseAndTidy zonked_ids ;
852 -- Update the interactive context
853 rn_env = ic_rn_local_env ictxt ;
854 type_env = ic_type_env ictxt ;
856 bound_names = map idName global_ids ;
857 new_rn_env = extendLocalRdrEnv rn_env bound_names ;
859 -- Remove any shadowed bindings from the type_env;
860 -- they are inaccessible but might, I suppose, cause
861 -- a space leak if we leave them there
862 shadowed = [ n | name <- bound_names,
863 let rdr_name = mkRdrUnqual (nameOccName name),
864 Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ;
866 filtered_type_env = delListFromNameEnv type_env shadowed ;
867 new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ;
869 new_ic = ictxt { ic_rn_local_env = new_rn_env,
870 ic_type_env = new_type_env }
873 dumpOptTcRn Opt_D_dump_tc
874 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
875 text "Typechecked expr" <+> ppr zonked_expr]) ;
877 returnM (new_ic, bound_names, zonked_expr)
880 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
881 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
883 globaliseAndTidy :: Id -> Id
885 -- Give the Id a Global Name, and tidy its type
886 = setIdType (globaliseId VanillaGlobal id) tidy_type
888 tidy_type = tidyTopType (idType id)
891 Here is the grand plan, implemented in tcUserStmt
893 What you type The IO [HValue] that hscStmt returns
894 ------------- ------------------------------------
895 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
898 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
901 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
902 [NB: result not printed] bindings: [it]
904 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
905 result showable) bindings: [it]
907 expr (of non-IO type,
908 result not showable) ==> error
912 ---------------------------
913 type PlanResult = ([Id], LHsExpr Id)
914 type Plan = TcM PlanResult
916 runPlans :: [Plan] -> TcM PlanResult
917 -- Try the plans in order. If one fails (by raising an exn), try the next.
918 -- If one succeeds, take it.
919 runPlans [] = panic "runPlans"
921 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
924 mkPlan :: LStmt Name -> TcM PlanResult
925 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
926 = do { uniq <- newUnique -- is treated very specially
927 ; let fresh_it = itName uniq
928 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
929 matches = [mkMatch [] expr emptyLocalBinds]
930 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
931 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
932 (HsVar bindIOName) noSyntaxExpr
933 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
934 (HsVar thenIOName) placeHolderType
937 -- [it <- e; print it] but not if it::()
939 -- [let it = e; print it]
940 ; runPlans [ -- Plan A
941 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
942 ; it_ty <- zonkTcType (idType it_id)
943 ; ifM (isUnitTy it_ty) failM
946 -- Plan B; a naked bind statment
947 tcGhciStmts [bind_stmt],
949 -- Plan C; check that the let-binding is typeable all by itself.
950 -- If not, fail; if so, try to print it.
951 -- The two-step process avoids getting two errors: one from
952 -- the expression itself, and one from the 'print it' part
953 -- This two-step story is very clunky, alas
954 do { checkNoErrs (tcGhciStmts [let_stmt])
955 --- checkNoErrs defeats the error recovery of let-bindings
956 ; tcGhciStmts [let_stmt, print_it] }
959 mkPlan stmt@(L loc (BindStmt {}))
960 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
961 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
962 (HsVar thenIOName) placeHolderType
964 -- [stmt; print v] but not if v::()
966 ; runPlans [do { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
967 ; v_ty <- zonkTcType (idType v_id)
968 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
976 ---------------------------
977 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
979 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
980 ret_id <- tcLookupId returnIOName ; -- return @ IO
982 io_ty = mkTyConApp ioTyCon [] ;
983 ret_ty = mkListTy unitTy ;
984 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
986 names = map unLoc (collectLStmtsBinders stmts) ;
988 -- mk_return builds the expression
989 -- returnIO @ [()] [coerce () x, .., coerce () z]
991 -- Despite the inconvenience of building the type applications etc,
992 -- this *has* to be done in type-annotated post-typecheck form
993 -- because we are going to return a list of *polymorphic* values
994 -- coerced to type (). If we built a *source* stmt
995 -- return [coerce x, ..., coerce z]
996 -- then the type checker would instantiate x..z, and we wouldn't
997 -- get their *polymorphic* values. (And we'd get ambiguity errs
998 -- if they were overloaded, since they aren't applied to anything.)
999 mk_return ids = nlHsApp (noLoc $ TyApp (nlHsVar ret_id) [ret_ty])
1000 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1001 mk_item id = nlHsApp (noLoc $ TyApp (nlHsVar unsafeCoerceId) [idType id, unitTy])
1005 -- OK, we're ready to typecheck the stmts
1006 traceTc (text "tcs 2") ;
1007 ((tc_stmts, ids), lie) <- getLIE $
1008 tcStmts DoExpr (tcDoStmt io_ty) stmts io_ret_ty $ \ _ ->
1009 mappM tcLookupId names ;
1010 -- Look up the names right in the middle,
1011 -- where they will all be in scope
1013 -- Simplify the context
1014 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1015 -- checkNoErrs ensures that the plan fails if context redn fails
1017 return (ids, mkHsDictLet const_binds $
1018 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1023 tcRnExpr just finds the type of an expression
1027 -> InteractiveContext
1030 tcRnExpr hsc_env ictxt rdr_expr
1031 = initTcPrintErrors hsc_env iNTERACTIVE $
1032 setInteractiveContext hsc_env ictxt $ do {
1034 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1037 -- Now typecheck the expression;
1038 -- it might have a rank-2 type (e.g. :t runST)
1039 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1040 ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1041 tcSimplifyInteractive lie_top ;
1042 qtvs' <- mappM zonkQuantifiedTyVar qtvs ;
1044 let { all_expr_ty = mkForAllTys qtvs' $
1045 mkFunTys (map idType dict_ids) $
1047 zonkTcType all_expr_ty
1050 smpl_doc = ptext SLIT("main expression")
1053 tcRnType just finds the kind of a type
1057 -> InteractiveContext
1060 tcRnType hsc_env ictxt rdr_type
1061 = initTcPrintErrors hsc_env iNTERACTIVE $
1062 setInteractiveContext hsc_env ictxt $ do {
1064 rn_type <- rnLHsType doc rdr_type ;
1067 -- Now kind-check the type
1068 (ty', kind) <- kcHsType rn_type ;
1072 doc = ptext SLIT("In GHCi input")
1078 %************************************************************************
1080 More GHCi stuff, to do with browsing and getting info
1082 %************************************************************************
1086 -- ASSUMES that the module is either in the HomePackageTable or is
1087 -- a package module with an interface on disk. If neither of these is
1088 -- true, then the result will be an error indicating the interface
1089 -- could not be found.
1090 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe NameSet)
1091 getModuleExports hsc_env mod
1092 = initTc hsc_env HsSrcFile iNTERACTIVE (tcGetModuleExports mod)
1094 tcGetModuleExports :: Module -> TcM NameSet
1095 tcGetModuleExports mod = do
1096 let doc = ptext SLIT("context for compiling statements")
1097 iface <- initIfaceTcRn $ loadSysInterface doc mod
1098 loadOrphanModules (dep_orphs (mi_deps iface))
1099 -- Load any orphan-module interfaces,
1100 -- so their instances are visible
1101 ifaceExportNames (mi_exports iface)
1103 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1104 tcRnLookupRdrName hsc_env rdr_name
1105 = initTcPrintErrors hsc_env iNTERACTIVE $
1106 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1107 lookup_rdr_name rdr_name
1109 lookup_rdr_name rdr_name = do {
1110 -- If the identifier is a constructor (begins with an
1111 -- upper-case letter), then we need to consider both
1112 -- constructor and type class identifiers.
1113 let { rdr_names = dataTcOccs rdr_name } ;
1115 -- results :: [Either Messages Name]
1116 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1118 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1119 -- The successful lookups will be (Just name)
1120 let { (warns_s, good_names) = unzip [ (msgs, name)
1121 | (msgs, Just name) <- results] ;
1122 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1124 -- Fail if nothing good happened, else add warnings
1125 if null good_names then
1126 -- No lookup succeeded, so
1127 -- pick the first error message and report it
1128 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1129 -- while the other is "X is not in scope",
1130 -- we definitely want the former; but we might pick the latter
1131 do { addMessages (head errs_s) ; failM }
1132 else -- Add deprecation warnings
1133 mapM_ addMessages warns_s ;
1139 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1140 tcRnLookupName hsc_env name
1141 = initTcPrintErrors hsc_env iNTERACTIVE $
1142 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1146 tcRnGetInfo :: HscEnv
1148 -> IO (Maybe (TyThing, Fixity, [Instance]))
1150 -- Used to implemnent :info in GHCi
1152 -- Look up a RdrName and return all the TyThings it might be
1153 -- A capitalised RdrName is given to us in the DataName namespace,
1154 -- but we want to treat it as *both* a data constructor
1155 -- *and* as a type or class constructor;
1156 -- hence the call to dataTcOccs, and we return up to two results
1157 tcRnGetInfo hsc_env name
1158 = initTcPrintErrors hsc_env iNTERACTIVE $
1159 let ictxt = hsc_IC hsc_env in
1160 setInteractiveContext hsc_env ictxt $ do
1162 -- Load the interface for all unqualified types and classes
1163 -- That way we will find all the instance declarations
1164 -- (Packages have not orphan modules, and we assume that
1165 -- in the home package all relevant modules are loaded.)
1166 loadUnqualIfaces ictxt
1168 thing <- tcLookupGlobal name
1169 fixity <- lookupFixityRn name
1170 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1171 return (thing, fixity, ispecs)
1174 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1175 -- Filter the instances by the ones whose tycons (or clases resp)
1176 -- are in scope unqualified. Otherwise we list a whole lot too many!
1177 lookupInsts print_unqual (AClass cls)
1178 = do { inst_envs <- tcGetInstEnvs
1180 | ispec <- classInstances inst_envs cls
1181 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1183 lookupInsts print_unqual (ATyCon tc)
1184 = do { eps <- getEps -- Load all instances for all classes that are
1185 -- in the type environment (which are all the ones
1186 -- we've seen in any interface file so far)
1187 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1189 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1190 , let dfun = instanceDFunId ispec
1192 , plausibleDFun print_unqual dfun ] }
1194 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1195 tc_name = tyConName tc
1197 lookupInsts print_unqual other = return []
1199 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1200 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1202 ok name | isBuiltInSyntax name = True
1203 | isExternalName name =
1204 isNothing $ fst print_unqual (nameModule name)
1208 loadUnqualIfaces :: InteractiveContext -> TcM ()
1209 -- Load the home module for everything that is in scope unqualified
1210 -- This is so that we can accurately report the instances for
1212 loadUnqualIfaces ictxt
1214 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1216 unqual_mods = [ nameModule name
1217 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1218 let name = gre_name gre,
1219 not (isInternalName name),
1220 isTcOcc (nameOccName name), -- Types and classes only
1221 unQualOK gre ] -- In scope unqualified
1222 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1226 %************************************************************************
1230 %************************************************************************
1233 rnDump :: SDoc -> TcRn ()
1234 -- Dump, with a banner, if -ddump-rn
1235 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1237 tcDump :: TcGblEnv -> TcRn ()
1239 = do { dflags <- getDOpts ;
1241 -- Dump short output if -ddump-types or -ddump-tc
1242 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1243 (dumpTcRn short_dump) ;
1245 -- Dump bindings if -ddump-tc
1246 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1249 short_dump = pprTcGblEnv env
1250 full_dump = pprLHsBinds (tcg_binds env)
1251 -- NB: foreign x-d's have undefined's in their types;
1252 -- hence can't show the tc_fords
1255 = do { dflags <- getDOpts ;
1256 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1257 (dumpTcRn (pprModGuts mod_guts)) ;
1259 -- Dump bindings if -ddump-tc
1260 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1262 full_dump = pprCoreBindings (mg_binds mod_guts)
1264 -- It's unpleasant having both pprModGuts and pprModDetails here
1265 pprTcGblEnv :: TcGblEnv -> SDoc
1266 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1267 tcg_insts = dfun_ids,
1269 tcg_imports = imports })
1270 = vcat [ ppr_types dfun_ids type_env
1271 , ppr_insts dfun_ids
1272 , vcat (map ppr rules)
1273 , ppr_gen_tycons (typeEnvTyCons type_env)
1274 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1275 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1277 pprModGuts :: ModGuts -> SDoc
1278 pprModGuts (ModGuts { mg_types = type_env,
1280 = vcat [ ppr_types [] type_env,
1284 ppr_types :: [Instance] -> TypeEnv -> SDoc
1285 ppr_types ispecs type_env
1286 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1288 dfun_ids = map instanceDFunId ispecs
1289 ids = [id | id <- typeEnvIds type_env, want_sig id]
1290 want_sig id | opt_PprStyle_Debug = True
1291 | otherwise = isLocalId id &&
1292 isExternalName (idName id) &&
1293 not (id `elem` dfun_ids)
1294 -- isLocalId ignores data constructors, records selectors etc.
1295 -- The isExternalName ignores local dictionary and method bindings
1296 -- that the type checker has invented. Top-level user-defined things
1297 -- have External names.
1299 ppr_insts :: [Instance] -> SDoc
1300 ppr_insts [] = empty
1301 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1303 ppr_sigs :: [Var] -> SDoc
1305 -- Print type signatures; sort by OccName
1306 = vcat (map ppr_sig (sortLe le_sig ids))
1308 le_sig id1 id2 = getOccName id1 <= getOccName id2
1309 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1311 ppr_rules :: [CoreRule] -> SDoc
1312 ppr_rules [] = empty
1313 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1314 nest 4 (pprRules rs),
1317 ppr_gen_tycons [] = empty
1318 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1319 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]