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 TyCon ( isOpenTyCon )
39 import TcHsSyn ( zonkTopDecls )
40 import TcExpr ( tcInferRho )
42 import TcType ( tidyTopType, tcEqType )
43 import Inst ( showLIE )
44 import InstEnv ( extendInstEnvList, Instance, pprInstances, instanceDFunId )
45 import TcBinds ( tcTopBinds, tcHsBootSigs )
46 import TcDefaults ( tcDefaults )
47 import TcEnv ( tcExtendGlobalValEnv, iDFunId )
48 import TcRules ( tcRules )
49 import TcForeign ( tcForeignImports, tcForeignExports )
50 import TcInstDcls ( tcInstDecls1, tcInstDecls2 )
51 import TcIface ( tcExtCoreBindings, tcHiBootIface )
52 import MkIface ( tyThingToIfaceDecl )
53 import IfaceSyn ( checkBootDecl, IfaceExtName(..) )
54 import TcSimplify ( tcSimplifyTop )
55 import TcTyClsDecls ( tcTyAndClassDecls )
56 import LoadIface ( loadOrphanModules )
57 import RnNames ( importsFromLocalDecls, rnImports, rnExports,
58 mkRdrEnvAndImports, mkExportNameSet,
59 reportUnusedNames, reportDeprecations )
60 import RnEnv ( lookupSrcOcc_maybe )
61 import RnSource ( rnSrcDecls, rnTyClDecls, checkModDeprec )
62 import PprCore ( pprRules, pprCoreBindings )
63 import CoreSyn ( CoreRule, bindersOfBinds )
64 import ErrUtils ( Messages, mkDumpDoc, showPass )
65 import Id ( Id, mkExportedLocalId, isLocalId, idName, idType )
68 import UniqFM ( elemUFM, eltsUFM )
69 import OccName ( mkVarOccFS, plusOccEnv )
70 import Name ( Name, NamedThing(..), isExternalName, getSrcLoc, isWiredInName,
71 nameModule, nameOccName, isImplicitName, mkExternalName )
73 import TyCon ( tyConHasGenerics )
74 import SrcLoc ( srcLocSpan, Located(..), noLoc )
75 import DriverPhases ( HscSource(..), isHsBoot )
76 import HscTypes ( ModGuts(..), ModDetails(..), emptyModDetails,
77 HscEnv(..), ExternalPackageState(..),
78 IsBootInterface, noDependencies,
79 Deprecs( NoDeprecs ), plusDeprecs,
80 ForeignStubs(NoStubs),
81 TypeEnv, lookupTypeEnv, hptInstances,
82 extendTypeEnvWithIds, typeEnvIds, typeEnvTyCons, typeEnvElts,
88 import HsSyn ( HsStmtContext(..), Stmt(..), HsExpr(..),
89 HsLocalBinds(..), HsValBinds(..),
90 LStmt, LHsExpr, LHsType, mkMatch, emptyLocalBinds,
91 collectLStmtsBinders, collectLStmtBinders, nlVarPat,
92 mkFunBind, placeHolderType, noSyntaxExpr, nlHsTyApp )
93 import RdrName ( GlobalRdrElt(..), globalRdrEnvElts,
94 unQualOK, lookupLocalRdrEnv, extendLocalRdrEnv )
95 import RnSource ( addTcgDUs )
96 import TcHsSyn ( mkHsDictLet, zonkTopLExpr, zonkTopBndrs )
97 import TcHsType ( kcHsType )
98 import TcMType ( zonkTcType, zonkQuantifiedTyVar )
99 import TcMatches ( tcStmts, tcDoStmt )
100 import TcSimplify ( tcSimplifyInteractive, tcSimplifyInfer )
101 import TcGadt ( emptyRefinement )
102 import TcType ( Type, mkForAllTys, mkFunTys, mkTyConApp, tyVarsOfType, isTauTy,
103 isUnLiftedType, tyClsNamesOfDFunHead, tyClsNamesOfType, isUnitTy )
104 import TcEnv ( tcLookupTyCon, tcLookupId, tcLookupGlobal )
105 import TypeRep ( TyThing(..) )
106 import RnTypes ( rnLHsType )
107 import Inst ( tcGetInstEnvs )
108 import InstEnv ( classInstances, instEnvElts )
109 import RnExpr ( rnStmts, rnLExpr )
110 import LoadIface ( loadSysInterface )
111 import IfaceEnv ( ifaceExportNames )
112 import RnEnv ( lookupOccRn, dataTcOccs, lookupFixityRn )
113 import Id ( setIdType )
114 import MkId ( unsafeCoerceId )
115 import TyCon ( tyConName )
116 import TysWiredIn ( mkListTy, unitTy )
117 import IdInfo ( GlobalIdDetails(..) )
118 import {- Kind parts of -} Type ( Kind )
119 import Var ( globaliseId )
120 import Name ( isBuiltInSyntax, isInternalName )
121 import OccName ( isTcOcc )
122 import NameEnv ( delListFromNameEnv )
123 import PrelNames ( iNTERACTIVE, ioTyConName, printName, itName,
124 bindIOName, thenIOName, returnIOName )
125 import HscTypes ( InteractiveContext(..),
126 ModIface(..), icPrintUnqual,
128 import BasicTypes ( Fixity, RecFlag(..) )
129 import SrcLoc ( unLoc )
130 import Data.Maybe ( isNothing )
133 import FastString ( mkFastString )
134 import Util ( sortLe )
135 import Bag ( unionBags, snocBag, emptyBag, unitBag, unionManyBags )
137 import Data.Maybe ( isJust )
142 %************************************************************************
144 Typecheck and rename a module
146 %************************************************************************
152 -> Bool -- True <=> save renamed syntax
153 -> Located (HsModule RdrName)
154 -> IO (Messages, Maybe TcGblEnv)
156 tcRnModule hsc_env hsc_src save_rn_syntax
157 (L loc (HsModule maybe_mod export_ies
158 import_decls local_decls mod_deprec))
159 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
161 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
162 this_mod = case maybe_mod of
163 Nothing -> mAIN -- 'module M where' is omitted
164 Just (L _ mod) -> mkModule this_pkg mod } ;
167 initTc hsc_env hsc_src this_mod $
170 -- Deal with imports;
171 rn_imports <- rnImports import_decls ;
172 (rdr_env, imports) <- mkRdrEnvAndImports rn_imports ;
174 let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
175 ; dep_mods = imp_dep_mods imports
177 -- We want instance declarations from all home-package
178 -- modules below this one, including boot modules, except
179 -- ourselves. The 'except ourselves' is so that we don't
180 -- get the instances from this module's hs-boot file
181 ; want_instances :: ModuleName -> Bool
182 ; want_instances mod = mod `elemUFM` dep_mods
183 && mod /= moduleName this_mod
184 ; home_insts = hptInstances hsc_env want_instances
187 -- Record boot-file info in the EPS, so that it's
188 -- visible to loadHiBootInterface in tcRnSrcDecls,
189 -- and any other incrementally-performed imports
190 updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
192 -- Update the gbl env
194 gbl { tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
195 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
196 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
197 tcg_rn_imports = if save_rn_syntax then
201 tcg_rn_decls = if save_rn_syntax then
207 traceRn (text "rn1" <+> ppr (imp_dep_mods imports)) ;
208 -- Fail if there are any errors so far
209 -- The error printing (if needed) takes advantage
210 -- of the tcg_env we have now set
213 -- Load any orphan-module interfaces, so that
214 -- their rules and instance decls will be found
215 loadOrphanModules (imp_orphs imports) ;
217 traceRn (text "rn1a") ;
218 -- Rename and type check the declarations
219 tcg_env <- if isHsBoot hsc_src then
220 tcRnHsBootDecls local_decls
222 tcRnSrcDecls local_decls ;
223 setGblEnv tcg_env $ do {
225 traceRn (text "rn3") ;
227 -- Report the use of any deprecated things
228 -- We do this before processsing the export list so
229 -- that we don't bleat about re-exporting a deprecated
230 -- thing (especially via 'module Foo' export item)
231 -- Only uses in the body of the module are complained about
232 reportDeprecations (hsc_dflags hsc_env) tcg_env ;
234 -- Process the export list
235 rn_exports <- rnExports export_ies ;
236 let { liftM2' fn a b = do a' <- a; b' <- b; return (fn a' b') } ;
237 exports <- mkExportNameSet (isJust maybe_mod) (liftM2' (,) rn_exports export_ies) ;
239 -- Check whether the entire module is deprecated
240 -- This happens only once per module
241 let { mod_deprecs = checkModDeprec mod_deprec } ;
243 -- Add exports and deprecations to envt
244 let { final_env = tcg_env { tcg_exports = exports,
245 tcg_rn_exports = if save_rn_syntax then
248 tcg_dus = tcg_dus tcg_env `plusDU` usesOnly exports,
249 tcg_deprecs = tcg_deprecs tcg_env `plusDeprecs`
251 -- A module deprecation over-rides the earlier ones
254 -- Report unused names
255 reportUnusedNames export_ies final_env ;
257 -- Dump output and 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 = emptyRdrGroup { hs_tyclds = decls }
342 %************************************************************************
344 Type-checking the top level of a module
346 %************************************************************************
349 tcRnSrcDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
350 -- Returns the variables free in the decls
351 -- Reason: solely to report unused imports and bindings
353 = do { -- Load the hi-boot interface for this module, if any
354 -- We do this now so that the boot_names can be passed
355 -- to tcTyAndClassDecls, because the boot_names are
356 -- automatically considered to be loop breakers
358 boot_iface <- tcHiBootIface mod ;
360 -- Do all the declarations
361 (tc_envs, lie) <- getLIE (tc_rn_src_decls boot_iface decls) ;
363 -- tcSimplifyTop deals with constant or ambiguous InstIds.
364 -- How could there be ambiguous ones? They can only arise if a
365 -- top-level decl falls under the monomorphism
366 -- restriction, and no subsequent decl instantiates its
367 -- type. (Usually, ambiguous type variables are resolved
368 -- during the generalisation step.)
369 traceTc (text "Tc8") ;
370 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
371 -- Setting the global env exposes the instances to tcSimplifyTop
372 -- Setting the local env exposes the local Ids to tcSimplifyTop,
373 -- so that we get better error messages (monomorphism restriction)
375 -- Backsubstitution. This must be done last.
376 -- Even tcSimplifyTop may do some unification.
377 traceTc (text "Tc9") ;
378 let { (tcg_env, _) = tc_envs ;
379 TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
380 tcg_rules = rules, tcg_fords = fords } = tcg_env } ;
383 (bind_ids, binds', fords', rules') <- zonkTopDecls (binds `unionBags` inst_binds)
386 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
387 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
390 tcg_fords = fords' } } ;
392 -- Make the new type env available to stuff slurped from interface files
393 writeMutVar (tcg_type_env_var tcg_env) final_type_env ;
395 -- Compare the hi-boot iface (if any) with the real thing
396 dfun_binds <- checkHiBootIface tcg_env' boot_iface ;
398 return (tcg_env' { tcg_binds = tcg_binds tcg_env' `unionBags` dfun_binds })
401 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
402 -- Loops around dealing with each top level inter-splice group
403 -- in turn, until it's dealt with the entire module
404 tc_rn_src_decls boot_details ds
405 = do { let { (first_group, group_tail) = findSplice ds } ;
406 -- If ds is [] we get ([], Nothing)
408 -- Type check the decls up to, but not including, the first splice
409 tc_envs@(tcg_env,tcl_env) <- tcRnGroup boot_details first_group ;
411 -- Bale out if errors; for example, error recovery when checking
412 -- the RHS of 'main' can mean that 'main' is not in the envt for
413 -- the subsequent checkMain test
418 -- If there is no splice, we're nearly done
420 Nothing -> do { -- Last thing: check for `main'
421 tcg_env <- checkMain ;
422 return (tcg_env, tcl_env)
425 -- If there's a splice, we must carry on
426 Just (SpliceDecl splice_expr, rest_ds) -> do {
428 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
431 -- Rename the splice expression, and get its supporting decls
432 (rn_splice_expr, splice_fvs) <- rnLExpr splice_expr ;
433 failIfErrsM ; -- Don't typecheck if renaming failed
434 rnDump (ppr rn_splice_expr) ;
436 -- Execute the splice
437 spliced_decls <- tcSpliceDecls rn_splice_expr ;
439 -- Glue them on the front of the remaining decls and loop
440 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
441 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
446 %************************************************************************
448 Compiling hs-boot source files, and
449 comparing the hi-boot interface with the real thing
451 %************************************************************************
454 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
455 tcRnHsBootDecls decls
456 = do { let { (first_group, group_tail) = findSplice decls }
459 Just stuff -> spliceInHsBootErr stuff
462 -- Rename the declarations
463 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
464 ; setGblEnv tcg_env $ do {
466 -- Todo: check no foreign decls, no rules, no default decls
468 -- Typecheck type/class decls
469 ; traceTc (text "Tc2")
470 ; let tycl_decls = hs_tyclds rn_group
471 ; tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails tycl_decls)
472 ; setGblEnv tcg_env $ do {
474 -- Typecheck instance decls
475 ; traceTc (text "Tc3")
476 ; (tcg_env, inst_infos, _binds) <- tcInstDecls1 tycl_decls (hs_instds rn_group)
477 ; setGblEnv tcg_env $ do {
479 -- Typecheck value declarations
480 ; traceTc (text "Tc5")
481 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
484 -- No simplification or zonking to do
485 ; traceTc (text "Tc7a")
486 ; gbl_env <- getGblEnv
488 -- Make the final type-env
489 -- Include the dfun_ids so that their type sigs get
490 -- are written into the interface file
491 ; let { type_env0 = tcg_type_env gbl_env
492 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
493 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
494 ; dfun_ids = map iDFunId inst_infos }
495 ; return (gbl_env { tcg_type_env = type_env2 })
498 spliceInHsBootErr (SpliceDecl (L loc _), _)
499 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
502 Once we've typechecked the body of the module, we want to compare what
503 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
506 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM (LHsBinds Id)
507 -- Compare the hi-boot file for this module (if there is one)
508 -- with the type environment we've just come up with
509 -- In the common case where there is no hi-boot file, the list
510 -- of boot_names is empty.
512 -- The bindings we return give bindings for the dfuns defined in the
513 -- hs-boot file, such as $fbEqT = $fEqT
516 (TcGblEnv { tcg_insts = local_insts, tcg_type_env = local_type_env })
517 (ModDetails { md_insts = boot_insts, md_types = boot_type_env })
518 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts)) ;
519 ; mapM_ check_one (typeEnvElts boot_type_env)
520 ; dfun_binds <- mapM check_inst boot_insts
521 ; return (unionManyBags dfun_binds) }
526 | Just real_thing <- lookupTypeEnv local_type_env name
527 = do { let boot_decl = tyThingToIfaceDecl ext_nm boot_thing
528 real_decl = tyThingToIfaceDecl ext_nm real_thing
529 ; checkTc (checkBootDecl boot_decl real_decl)
530 (bootMisMatch boot_thing boot_decl real_decl) }
531 -- The easiest way to check compatibility is to convert to
532 -- iface syntax, where we already have good comparison functions
534 = addErrTc (missingBootThing boot_thing)
536 name = getName boot_thing
538 ext_nm name = ExtPkg (nameModule name) (nameOccName name)
539 -- Just enough to compare; no versions etc needed
541 no_check name = isWiredInName name -- No checking for wired-in names. In particular,
542 -- 'error' is handled by a rather gross hack
543 -- (see comments in GHC.Err.hs-boot)
544 || name `elem` dfun_names
545 || isImplicitName name -- Has a parent, which we'll check
547 dfun_names = map getName boot_insts
550 = case [dfun | inst <- local_insts,
551 let dfun = instanceDFunId inst,
552 idType dfun `tcEqType` boot_inst_ty ] of
553 [] -> do { addErrTc (instMisMatch boot_inst); return emptyBag }
554 (dfun:_) -> return (unitBag $ noLoc $ VarBind local_boot_dfun (nlHsVar dfun))
556 boot_dfun = instanceDFunId boot_inst
557 boot_inst_ty = idType boot_dfun
558 local_boot_dfun = mkExportedLocalId (idName boot_dfun) boot_inst_ty
561 missingBootThing thing
562 = ppr thing <+> ptext SLIT("is defined in the hs-boot file, but not in the module")
563 bootMisMatch thing boot_decl real_decl
564 = ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file")
567 2 (ptext SLIT("is defined in the hs-boot file, but not in the module"))
571 %************************************************************************
573 Type-checking the top level of a module
575 %************************************************************************
577 tcRnGroup takes a bunch of top-level source-code declarations, and
579 * gets supporting declarations from interface files
582 * and augments the TcGblEnv with the results
584 In Template Haskell it may be called repeatedly for each group of
585 declarations. It expects there to be an incoming TcGblEnv in the
586 monad; it augments it and returns the new TcGblEnv.
589 tcRnGroup :: ModDetails -> HsGroup RdrName -> TcM (TcGblEnv, TcLclEnv)
590 -- Returns the variables free in the decls, for unused-binding reporting
591 tcRnGroup boot_details decls
592 = do { -- Rename the declarations
593 (tcg_env, rn_decls) <- rnTopSrcDecls decls ;
594 setGblEnv tcg_env $ do {
596 -- Typecheck the declarations
597 tcTopSrcDecls boot_details rn_decls
600 ------------------------------------------------
601 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
603 = do { -- Bring top level binders into scope
604 tcg_env <- importsFromLocalDecls group ;
605 setGblEnv tcg_env $ do {
607 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
609 -- Rename the source decls
610 (tcg_env, rn_decls) <- rnSrcDecls group ;
613 -- save the renamed syntax, if we want it
615 | Just grp <- tcg_rn_decls tcg_env
616 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
620 -- Dump trace of renaming part
621 rnDump (ppr rn_decls) ;
623 return (tcg_env', rn_decls)
626 ------------------------------------------------
627 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
628 tcTopSrcDecls boot_details
629 (HsGroup { hs_tyclds = tycl_decls,
630 hs_instds = inst_decls,
631 hs_fords = foreign_decls,
632 hs_defds = default_decls,
633 hs_ruleds = rule_decls,
634 hs_valds = val_binds })
635 = do { -- Type-check the type and class decls, and all imported decls
636 -- The latter come in via tycl_decls
637 traceTc (text "Tc2") ;
639 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
640 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
641 -- an error we'd better stop now, to avoid a cascade
643 -- Make these type and class decls available to stuff slurped from interface files
644 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
647 setGblEnv tcg_env $ do {
648 -- Source-language instances, including derivings,
649 -- and import the supporting declarations
650 traceTc (text "Tc3") ;
651 (tcg_env, inst_infos, deriv_binds) <- tcInstDecls1 tycl_decls inst_decls ;
652 setGblEnv tcg_env $ do {
654 -- Foreign import declarations next. No zonking necessary
655 -- here; we can tuck them straight into the global environment.
656 traceTc (text "Tc4") ;
657 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
658 tcExtendGlobalValEnv fi_ids $ do {
660 -- Default declarations
661 traceTc (text "Tc4a") ;
662 default_tys <- tcDefaults default_decls ;
663 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
665 -- Value declarations next
666 -- We also typecheck any extra binds that came out
667 -- of the "deriving" process (deriv_binds)
668 traceTc (text "Tc5") ;
669 (tc_val_binds, tcl_env) <- tcTopBinds (val_binds `plusHsValBinds` deriv_binds) ;
670 setLclTypeEnv tcl_env $ do {
672 -- Second pass over class and instance declarations,
673 traceTc (text "Tc6") ;
674 (inst_binds, tcl_env) <- tcInstDecls2 tycl_decls inst_infos ;
675 showLIE (text "after instDecls2") ;
678 -- They need to be zonked, so we return them
679 traceTc (text "Tc7") ;
680 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
683 rules <- tcRules rule_decls ;
686 traceTc (text "Tc7a") ;
687 tcg_env <- getGblEnv ;
688 let { all_binds = tc_val_binds `unionBags`
689 inst_binds `unionBags`
692 -- Extend the GblEnv with the (as yet un-zonked)
693 -- bindings, rules, foreign decls
694 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
695 tcg_rules = tcg_rules tcg_env ++ rules,
696 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
697 return (tcg_env', tcl_env)
702 %************************************************************************
706 %************************************************************************
709 checkMain :: TcM TcGblEnv
710 -- If we are in module Main, check that 'main' is defined.
712 = do { ghc_mode <- getGhcMode ;
713 tcg_env <- getGblEnv ;
715 let { main_mod = mainModIs dflags ;
716 main_fn = case mainFunIs dflags of {
717 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn)) ;
718 Nothing -> main_RDR_Unqual } } ;
720 check_main ghc_mode tcg_env main_mod main_fn
724 check_main ghc_mode tcg_env main_mod main_fn
726 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
730 = addErrCtxt mainCtxt $
731 do { mb_main <- lookupSrcOcc_maybe main_fn
732 -- Check that 'main' is in scope
733 -- It might be imported from another module!
735 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
739 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
740 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
741 -- :Main.main :: IO () = runMainIO main
743 ; (main_expr, ty) <- setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
746 -- The function that the RTS invokes is always :Main.main,
747 -- which we call root_main_id.
748 -- (Because GHC allows the user to have a module not called
749 -- Main as the main module, we can't rely on the main function
750 -- being called "Main.main". That's why root_main_id has a fixed
752 -- We also make root_main_id an implicit Id, by making main_name
753 -- its parent (hence (Just main_name)). That has the effect
754 -- of preventing its type and unfolding from getting out into
755 -- the interface file. Otherwise we can end up with two defns
756 -- for 'main' in the interface file!
758 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
759 (mkVarOccFS FSLIT("main"))
760 (Just main_name) (getSrcLoc main_name)
761 ; root_main_id = mkExportedLocalId root_main_name ty
762 ; main_bind = noLoc (VarBind root_main_id main_expr) }
764 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
766 tcg_dus = tcg_dus tcg_env
767 `plusDU` usesOnly (unitFV main_name)
768 -- Record the use of 'main', so that we don't
769 -- complain about it being defined but not used
773 mod = tcg_mod tcg_env
775 complain_no_main | ghc_mode == Interactive = return ()
776 | otherwise = failWithTc noMainMsg
777 -- In interactive mode, don't worry about the absence of 'main'
778 -- In other modes, fail altogether, so that we don't go on
779 -- and complain a second time when processing the export list.
781 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
782 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
783 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
786 %*********************************************************
790 %*********************************************************
794 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
795 setInteractiveContext hsc_env icxt thing_inside
797 -- Initialise the tcg_inst_env with instances
798 -- from all home modules. This mimics the more selective
799 -- call to hptInstances in tcRnModule
800 dfuns = hptInstances hsc_env (\mod -> True)
802 updGblEnv (\env -> env {
803 tcg_rdr_env = ic_rn_gbl_env icxt,
804 tcg_type_env = ic_type_env icxt,
805 tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
807 updLclEnv (\env -> env { tcl_rdr = ic_rn_local_env icxt }) $
809 do { traceTc (text "setIC" <+> ppr (ic_type_env icxt))
816 -> InteractiveContext
818 -> IO (Maybe (InteractiveContext, [Name], LHsExpr Id))
819 -- The returned [Name] is the same as the input except for
820 -- ExprStmt, in which case the returned [Name] is [itName]
822 -- The returned TypecheckedHsExpr is of type IO [ () ],
823 -- a list of the bound values, coerced to ().
825 tcRnStmt hsc_env ictxt rdr_stmt
826 = initTcPrintErrors hsc_env iNTERACTIVE $
827 setInteractiveContext hsc_env ictxt $ do {
829 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
830 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
831 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
834 -- The real work is done here
835 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
836 zonked_expr <- zonkTopLExpr tc_expr ;
837 zonked_ids <- zonkTopBndrs bound_ids ;
839 -- None of the Ids should be of unboxed type, because we
840 -- cast them all to HValues in the end!
841 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
843 traceTc (text "tcs 1") ;
844 let { -- (a) Make all the bound ids "global" ids, now that
845 -- they're notionally top-level bindings. This is
846 -- important: otherwise when we come to compile an expression
847 -- using these ids later, the byte code generator will consider
848 -- the occurrences to be free rather than global.
850 -- (b) Tidy their types; this is important, because :info may
851 -- ask to look at them, and :info expects the things it looks
852 -- up to have tidy types
853 global_ids = map globaliseAndTidy zonked_ids ;
855 -- Update the interactive context
856 rn_env = ic_rn_local_env ictxt ;
857 type_env = ic_type_env ictxt ;
859 bound_names = map idName global_ids ;
860 new_rn_env = extendLocalRdrEnv rn_env bound_names ;
862 -- Remove any shadowed bindings from the type_env;
863 -- they are inaccessible but might, I suppose, cause
864 -- a space leak if we leave them there
865 shadowed = [ n | name <- bound_names,
866 let rdr_name = mkRdrUnqual (nameOccName name),
867 Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ;
869 filtered_type_env = delListFromNameEnv type_env shadowed ;
870 new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ;
872 new_ic = ictxt { ic_rn_local_env = new_rn_env,
873 ic_type_env = new_type_env }
876 dumpOptTcRn Opt_D_dump_tc
877 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
878 text "Typechecked expr" <+> ppr zonked_expr]) ;
880 returnM (new_ic, bound_names, zonked_expr)
883 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
884 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
886 globaliseAndTidy :: Id -> Id
888 -- Give the Id a Global Name, and tidy its type
889 = setIdType (globaliseId VanillaGlobal id) tidy_type
891 tidy_type = tidyTopType (idType id)
894 Here is the grand plan, implemented in tcUserStmt
896 What you type The IO [HValue] that hscStmt returns
897 ------------- ------------------------------------
898 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
901 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
904 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
905 [NB: result not printed] bindings: [it]
907 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
908 result showable) bindings: [it]
910 expr (of non-IO type,
911 result not showable) ==> error
915 ---------------------------
916 type PlanResult = ([Id], LHsExpr Id)
917 type Plan = TcM PlanResult
919 runPlans :: [Plan] -> TcM PlanResult
920 -- Try the plans in order. If one fails (by raising an exn), try the next.
921 -- If one succeeds, take it.
922 runPlans [] = panic "runPlans"
924 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
927 mkPlan :: LStmt Name -> TcM PlanResult
928 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
929 = do { uniq <- newUnique -- is treated very specially
930 ; let fresh_it = itName uniq
931 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
932 matches = [mkMatch [] expr emptyLocalBinds]
933 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
934 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
935 (HsVar bindIOName) noSyntaxExpr
936 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
937 (HsVar thenIOName) placeHolderType
940 -- [it <- e; print it] but not if it::()
942 -- [let it = e; print it]
943 ; runPlans [ -- Plan A
944 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
945 ; it_ty <- zonkTcType (idType it_id)
946 ; ifM (isUnitTy it_ty) failM
949 -- Plan B; a naked bind statment
950 tcGhciStmts [bind_stmt],
952 -- Plan C; check that the let-binding is typeable all by itself.
953 -- If not, fail; if so, try to print it.
954 -- The two-step process avoids getting two errors: one from
955 -- the expression itself, and one from the 'print it' part
956 -- This two-step story is very clunky, alas
957 do { checkNoErrs (tcGhciStmts [let_stmt])
958 --- checkNoErrs defeats the error recovery of let-bindings
959 ; tcGhciStmts [let_stmt, print_it] }
962 mkPlan stmt@(L loc (BindStmt {}))
963 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
964 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
965 (HsVar thenIOName) placeHolderType
967 -- [stmt; print v] but not if v::()
969 ; runPlans [do { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
970 ; v_ty <- zonkTcType (idType v_id)
971 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
979 ---------------------------
980 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
982 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
983 ret_id <- tcLookupId returnIOName ; -- return @ IO
985 io_ty = mkTyConApp ioTyCon [] ;
986 ret_ty = mkListTy unitTy ;
987 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
988 tc_io_stmts stmts = tcStmts DoExpr (tcDoStmt io_ty) stmts
989 (emptyRefinement, io_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 (nlHsTyApp ret_id [ret_ty])
1005 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1006 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1010 -- OK, we're ready to typecheck the stmts
1011 traceTc (text "tcs 2") ;
1012 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1013 mappM tcLookupId names ;
1014 -- Look up the names right in the middle,
1015 -- where they will all be in scope
1017 -- Simplify the context
1018 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1019 -- checkNoErrs ensures that the plan fails if context redn fails
1021 return (ids, mkHsDictLet const_binds $
1022 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1027 tcRnExpr just finds the type of an expression
1031 -> InteractiveContext
1034 tcRnExpr hsc_env ictxt rdr_expr
1035 = initTcPrintErrors hsc_env iNTERACTIVE $
1036 setInteractiveContext hsc_env ictxt $ do {
1038 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1041 -- Now typecheck the expression;
1042 -- it might have a rank-2 type (e.g. :t runST)
1043 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1044 ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1045 tcSimplifyInteractive lie_top ;
1046 qtvs' <- mappM zonkQuantifiedTyVar qtvs ;
1048 let { all_expr_ty = mkForAllTys qtvs' $
1049 mkFunTys (map idType dict_ids) $
1051 zonkTcType all_expr_ty
1054 smpl_doc = ptext SLIT("main expression")
1057 tcRnType just finds the kind of a type
1061 -> InteractiveContext
1064 tcRnType hsc_env ictxt rdr_type
1065 = initTcPrintErrors hsc_env iNTERACTIVE $
1066 setInteractiveContext hsc_env ictxt $ do {
1068 rn_type <- rnLHsType doc rdr_type ;
1071 -- Now kind-check the type
1072 (ty', kind) <- kcHsType rn_type ;
1076 doc = ptext SLIT("In GHCi input")
1082 %************************************************************************
1084 More GHCi stuff, to do with browsing and getting info
1086 %************************************************************************
1090 -- ASSUMES that the module is either in the HomePackageTable or is
1091 -- a package module with an interface on disk. If neither of these is
1092 -- true, then the result will be an error indicating the interface
1093 -- could not be found.
1094 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe NameSet)
1095 getModuleExports hsc_env mod
1096 = initTc hsc_env HsSrcFile iNTERACTIVE (tcGetModuleExports mod)
1098 tcGetModuleExports :: Module -> TcM NameSet
1099 tcGetModuleExports mod = do
1100 let doc = ptext SLIT("context for compiling statements")
1101 iface <- initIfaceTcRn $ loadSysInterface doc 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 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1108 tcRnLookupRdrName hsc_env rdr_name
1109 = initTcPrintErrors hsc_env iNTERACTIVE $
1110 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1111 lookup_rdr_name rdr_name
1113 lookup_rdr_name rdr_name = do {
1114 -- If the identifier is a constructor (begins with an
1115 -- upper-case letter), then we need to consider both
1116 -- constructor and type class identifiers.
1117 let { rdr_names = dataTcOccs rdr_name } ;
1119 -- results :: [Either Messages Name]
1120 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1122 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1123 -- The successful lookups will be (Just name)
1124 let { (warns_s, good_names) = unzip [ (msgs, name)
1125 | (msgs, Just name) <- results] ;
1126 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1128 -- Fail if nothing good happened, else add warnings
1129 if null good_names then
1130 -- No lookup succeeded, so
1131 -- pick the first error message and report it
1132 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1133 -- while the other is "X is not in scope",
1134 -- we definitely want the former; but we might pick the latter
1135 do { addMessages (head errs_s) ; failM }
1136 else -- Add deprecation warnings
1137 mapM_ addMessages warns_s ;
1143 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1144 tcRnLookupName hsc_env name
1145 = initTcPrintErrors hsc_env iNTERACTIVE $
1146 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1150 tcRnGetInfo :: HscEnv
1152 -> IO (Maybe (TyThing, Fixity, [Instance]))
1154 -- Used to implemnent :info in GHCi
1156 -- Look up a RdrName and return all the TyThings it might be
1157 -- A capitalised RdrName is given to us in the DataName namespace,
1158 -- but we want to treat it as *both* a data constructor
1159 -- *and* as a type or class constructor;
1160 -- hence the call to dataTcOccs, and we return up to two results
1161 tcRnGetInfo hsc_env name
1162 = initTcPrintErrors hsc_env iNTERACTIVE $
1163 let ictxt = hsc_IC hsc_env in
1164 setInteractiveContext hsc_env ictxt $ do
1166 -- Load the interface for all unqualified types and classes
1167 -- That way we will find all the instance declarations
1168 -- (Packages have not orphan modules, and we assume that
1169 -- in the home package all relevant modules are loaded.)
1170 loadUnqualIfaces ictxt
1172 thing <- tcLookupGlobal name
1173 fixity <- lookupFixityRn name
1174 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1175 return (thing, fixity, ispecs)
1178 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1179 -- Filter the instances by the ones whose tycons (or clases resp)
1180 -- are in scope unqualified. Otherwise we list a whole lot too many!
1181 lookupInsts print_unqual (AClass cls)
1182 = do { inst_envs <- tcGetInstEnvs
1184 | ispec <- classInstances inst_envs cls
1185 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1187 lookupInsts print_unqual (ATyCon tc)
1188 = do { eps <- getEps -- Load all instances for all classes that are
1189 -- in the type environment (which are all the ones
1190 -- we've seen in any interface file so far)
1191 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1193 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1194 , let dfun = instanceDFunId ispec
1196 , plausibleDFun print_unqual dfun ] }
1198 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1199 tc_name = tyConName tc
1201 lookupInsts print_unqual other = return []
1203 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1204 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1206 ok name | isBuiltInSyntax name = True
1207 | isExternalName name =
1208 isNothing $ fst print_unqual (nameModule name)
1212 loadUnqualIfaces :: InteractiveContext -> TcM ()
1213 -- Load the home module for everything that is in scope unqualified
1214 -- This is so that we can accurately report the instances for
1216 loadUnqualIfaces ictxt
1218 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1220 unqual_mods = [ nameModule name
1221 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1222 let name = gre_name gre,
1223 not (isInternalName name),
1224 isTcOcc (nameOccName name), -- Types and classes only
1225 unQualOK gre ] -- In scope unqualified
1226 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1230 %************************************************************************
1234 %************************************************************************
1237 rnDump :: SDoc -> TcRn ()
1238 -- Dump, with a banner, if -ddump-rn
1239 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1241 tcDump :: TcGblEnv -> TcRn ()
1243 = do { dflags <- getDOpts ;
1245 -- Dump short output if -ddump-types or -ddump-tc
1246 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1247 (dumpTcRn short_dump) ;
1249 -- Dump bindings if -ddump-tc
1250 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1253 short_dump = pprTcGblEnv env
1254 full_dump = pprLHsBinds (tcg_binds env)
1255 -- NB: foreign x-d's have undefined's in their types;
1256 -- hence can't show the tc_fords
1259 = do { dflags <- getDOpts ;
1260 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1261 (dumpTcRn (pprModGuts mod_guts)) ;
1263 -- Dump bindings if -ddump-tc
1264 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1266 full_dump = pprCoreBindings (mg_binds mod_guts)
1268 -- It's unpleasant having both pprModGuts and pprModDetails here
1269 pprTcGblEnv :: TcGblEnv -> SDoc
1270 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1271 tcg_insts = dfun_ids,
1273 tcg_imports = imports })
1274 = vcat [ ppr_types dfun_ids type_env
1275 , ppr_insts dfun_ids
1276 , vcat (map ppr rules)
1277 , ppr_gen_tycons (typeEnvTyCons type_env)
1278 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1279 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1281 pprModGuts :: ModGuts -> SDoc
1282 pprModGuts (ModGuts { mg_types = type_env,
1284 = vcat [ ppr_types [] type_env,
1288 ppr_types :: [Instance] -> TypeEnv -> SDoc
1289 ppr_types ispecs type_env
1290 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1292 dfun_ids = map instanceDFunId ispecs
1293 ids = [id | id <- typeEnvIds type_env, want_sig id]
1294 want_sig id | opt_PprStyle_Debug = True
1295 | otherwise = isLocalId id &&
1296 isExternalName (idName id) &&
1297 not (id `elem` dfun_ids)
1298 -- isLocalId ignores data constructors, records selectors etc.
1299 -- The isExternalName ignores local dictionary and method bindings
1300 -- that the type checker has invented. Top-level user-defined things
1301 -- have External names.
1303 ppr_insts :: [Instance] -> SDoc
1304 ppr_insts [] = empty
1305 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1307 ppr_sigs :: [Var] -> SDoc
1309 -- Print type signatures; sort by OccName
1310 = vcat (map ppr_sig (sortLe le_sig ids))
1312 le_sig id1 id2 = getOccName id1 <= getOccName id2
1313 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1315 ppr_rules :: [CoreRule] -> SDoc
1316 ppr_rules [] = empty
1317 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1318 nest 4 (pprRules rs),
1321 ppr_gen_tycons [] = empty
1322 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1323 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]