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 MkIface ( tyThingToIfaceDecl )
52 import IfaceSyn ( checkBootDecl, IfaceExtName(..) )
53 import TcSimplify ( tcSimplifyTop )
54 import TcTyClsDecls ( tcTyAndClassDecls )
55 import LoadIface ( loadOrphanModules )
56 import RnNames ( importsFromLocalDecls, rnImports, rnExports,
57 mkRdrEnvAndImports, mkExportNameSet,
58 reportUnusedNames, reportDeprecations )
59 import RnEnv ( lookupSrcOcc_maybe )
60 import RnSource ( rnSrcDecls, rnTyClDecls, checkModDeprec )
61 import PprCore ( pprRules, pprCoreBindings )
62 import CoreSyn ( CoreRule, bindersOfBinds )
63 import ErrUtils ( Messages, mkDumpDoc, showPass )
64 import Id ( Id, mkExportedLocalId, isLocalId, idName, idType )
67 import UniqFM ( elemUFM, eltsUFM )
68 import OccName ( mkVarOccFS, plusOccEnv )
69 import Name ( Name, NamedThing(..), isExternalName, getSrcLoc, isWiredInName,
70 nameModule, nameOccName, isImplicitName, mkExternalName )
72 import TyCon ( tyConHasGenerics )
73 import SrcLoc ( srcLocSpan, Located(..), noLoc )
74 import DriverPhases ( HscSource(..), isHsBoot )
75 import HscTypes ( ModGuts(..), ModDetails(..), emptyModDetails,
76 HscEnv(..), ExternalPackageState(..),
77 IsBootInterface, noDependencies,
78 Deprecs( NoDeprecs ), plusDeprecs,
79 ForeignStubs(NoStubs),
80 TypeEnv, lookupTypeEnv, hptInstances,
81 extendTypeEnvWithIds, typeEnvIds, typeEnvTyCons, typeEnvElts,
87 import HsSyn ( HsStmtContext(..), Stmt(..), HsExpr(..),
88 HsLocalBinds(..), HsValBinds(..),
89 LStmt, LHsExpr, LHsType, mkMatch, emptyLocalBinds,
90 collectLStmtsBinders, collectLStmtBinders, nlVarPat,
91 mkFunBind, placeHolderType, noSyntaxExpr, nlHsTyApp )
92 import RdrName ( GlobalRdrElt(..), globalRdrEnvElts,
93 unQualOK, lookupLocalRdrEnv, extendLocalRdrEnv )
94 import RnSource ( addTcgDUs )
95 import TcHsSyn ( mkHsDictLet, zonkTopLExpr, zonkTopBndrs )
96 import TcHsType ( kcHsType )
97 import TcMType ( zonkTcType, zonkQuantifiedTyVar )
98 import TcMatches ( tcStmts, tcDoStmt )
99 import TcSimplify ( tcSimplifyInteractive, tcSimplifyInfer )
100 import TcGadt ( emptyRefinement )
101 import TcType ( Type, mkForAllTys, mkFunTys, mkTyConApp, tyVarsOfType, isTauTy,
102 isUnLiftedType, tyClsNamesOfDFunHead, tyClsNamesOfType, isUnitTy )
103 import TcEnv ( tcLookupTyCon, tcLookupId, tcLookupGlobal )
104 import TypeRep ( TyThing(..) )
105 import RnTypes ( rnLHsType )
106 import Inst ( tcGetInstEnvs )
107 import InstEnv ( classInstances, instEnvElts )
108 import RnExpr ( rnStmts, rnLExpr )
109 import LoadIface ( loadSysInterface )
110 import IfaceEnv ( ifaceExportNames )
111 import RnEnv ( lookupOccRn, dataTcOccs, lookupFixityRn )
112 import Id ( setIdType )
113 import MkId ( unsafeCoerceId )
114 import TyCon ( tyConName )
115 import TysWiredIn ( mkListTy, unitTy )
116 import IdInfo ( GlobalIdDetails(..) )
117 import {- Kind parts of -} Type ( Kind )
118 import Var ( globaliseId )
119 import Name ( isBuiltInSyntax, isInternalName )
120 import OccName ( isTcOcc )
121 import NameEnv ( delListFromNameEnv )
122 import PrelNames ( iNTERACTIVE, ioTyConName, printName, itName,
123 bindIOName, thenIOName, returnIOName )
124 import HscTypes ( InteractiveContext(..),
125 ModIface(..), icPrintUnqual,
127 import BasicTypes ( Fixity, RecFlag(..) )
128 import SrcLoc ( unLoc )
129 import Data.Maybe ( isNothing )
132 import FastString ( mkFastString )
133 import Util ( sortLe )
134 import Bag ( unionBags, snocBag, emptyBag, unitBag, unionManyBags )
136 import Data.Maybe ( isJust )
141 %************************************************************************
143 Typecheck and rename a module
145 %************************************************************************
151 -> Bool -- True <=> save renamed syntax
152 -> Located (HsModule RdrName)
153 -> IO (Messages, Maybe TcGblEnv)
155 tcRnModule hsc_env hsc_src save_rn_syntax
156 (L loc (HsModule maybe_mod export_ies
157 import_decls local_decls mod_deprec))
158 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
160 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
161 this_mod = case maybe_mod of
162 Nothing -> mAIN -- 'module M where' is omitted
163 Just (L _ mod) -> mkModule this_pkg mod } ;
166 initTc hsc_env hsc_src this_mod $
169 -- Deal with imports;
170 rn_imports <- rnImports import_decls ;
171 (rdr_env, imports) <- mkRdrEnvAndImports rn_imports ;
173 let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
174 ; dep_mods = imp_dep_mods imports
176 -- We want instance declarations from all home-package
177 -- modules below this one, including boot modules, except
178 -- ourselves. The 'except ourselves' is so that we don't
179 -- get the instances from this module's hs-boot file
180 ; want_instances :: ModuleName -> Bool
181 ; want_instances mod = mod `elemUFM` dep_mods
182 && mod /= moduleName this_mod
183 ; home_insts = hptInstances hsc_env want_instances
186 -- Record boot-file info in the EPS, so that it's
187 -- visible to loadHiBootInterface in tcRnSrcDecls,
188 -- and any other incrementally-performed imports
189 updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
191 -- Update the gbl env
193 gbl { tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
194 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
195 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
196 tcg_rn_imports = if save_rn_syntax then
200 tcg_rn_decls = if save_rn_syntax then
206 traceRn (text "rn1" <+> ppr (imp_dep_mods imports)) ;
207 -- Fail if there are any errors so far
208 -- The error printing (if needed) takes advantage
209 -- of the tcg_env we have now set
212 -- Load any orphan-module interfaces, so that
213 -- their rules and instance decls will be found
214 loadOrphanModules (imp_orphs imports) ;
216 traceRn (text "rn1a") ;
217 -- Rename and type check the declarations
218 tcg_env <- if isHsBoot hsc_src then
219 tcRnHsBootDecls local_decls
221 tcRnSrcDecls local_decls ;
222 setGblEnv tcg_env $ do {
224 traceRn (text "rn3") ;
226 -- Report the use of any deprecated things
227 -- We do this before processsing the export list so
228 -- that we don't bleat about re-exporting a deprecated
229 -- thing (especially via 'module Foo' export item)
230 -- Only uses in the body of the module are complained about
231 reportDeprecations (hsc_dflags hsc_env) tcg_env ;
233 -- Process the export list
234 rn_exports <- rnExports export_ies ;
235 let { liftM2' fn a b = do a' <- a; b' <- b; return (fn a' b') } ;
236 exports <- mkExportNameSet (isJust maybe_mod) (liftM2' (,) rn_exports export_ies) ;
238 -- Check whether the entire module is deprecated
239 -- This happens only once per module
240 let { mod_deprecs = checkModDeprec mod_deprec } ;
242 -- Add exports and deprecations to envt
243 let { final_env = tcg_env { tcg_exports = exports,
244 tcg_rn_exports = if save_rn_syntax then
247 tcg_dus = tcg_dus tcg_env `plusDU` usesOnly exports,
248 tcg_deprecs = tcg_deprecs tcg_env `plusDeprecs`
250 -- A module deprecation over-rides the earlier ones
253 -- Report unused names
254 reportUnusedNames export_ies final_env ;
256 -- Dump output and return
263 %************************************************************************
265 Type-checking external-core modules
267 %************************************************************************
270 tcRnExtCore :: HscEnv
272 -> IO (Messages, Maybe ModGuts)
273 -- Nothing => some error occurred
275 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
276 -- The decls are IfaceDecls; all names are original names
277 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
279 initTc hsc_env ExtCoreFile this_mod $ do {
281 let { ldecls = map noLoc decls } ;
283 -- Deal with the type declarations; first bring their stuff
284 -- into scope, then rname them, then type check them
285 tcg_env <- importsFromLocalDecls (mkFakeGroup ldecls) ;
287 setGblEnv tcg_env $ do {
289 rn_decls <- rnTyClDecls ldecls ;
292 -- Dump trace of renaming part
293 rnDump (ppr rn_decls) ;
295 -- Typecheck them all together so that
296 -- any mutually recursive types are done right
297 tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails rn_decls) ;
298 -- Make the new type env available to stuff slurped from interface files
300 setGblEnv tcg_env $ do {
302 -- Now the core bindings
303 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
307 bndrs = bindersOfBinds core_binds ;
308 my_exports = mkNameSet (map idName bndrs) ;
309 -- ToDo: export the data types also?
311 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
313 mod_guts = ModGuts { mg_module = this_mod,
315 mg_usages = [], -- ToDo: compute usage
316 mg_dir_imps = [], -- ??
317 mg_deps = noDependencies, -- ??
318 mg_exports = my_exports,
319 mg_types = final_type_env,
320 mg_insts = tcg_insts tcg_env,
322 mg_binds = core_binds,
325 mg_rdr_env = emptyGlobalRdrEnv,
326 mg_fix_env = emptyFixityEnv,
327 mg_deprecs = NoDeprecs,
331 tcCoreDump mod_guts ;
336 mkFakeGroup decls -- Rather clumsy; lots of unused fields
337 = emptyRdrGroup { hs_tyclds = decls }
341 %************************************************************************
343 Type-checking the top level of a module
345 %************************************************************************
348 tcRnSrcDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
349 -- Returns the variables free in the decls
350 -- Reason: solely to report unused imports and bindings
352 = do { -- Load the hi-boot interface for this module, if any
353 -- We do this now so that the boot_names can be passed
354 -- to tcTyAndClassDecls, because the boot_names are
355 -- automatically considered to be loop breakers
357 boot_iface <- tcHiBootIface mod ;
359 -- Do all the declarations
360 (tc_envs, lie) <- getLIE (tc_rn_src_decls boot_iface decls) ;
362 -- tcSimplifyTop deals with constant or ambiguous InstIds.
363 -- How could there be ambiguous ones? They can only arise if a
364 -- top-level decl falls under the monomorphism
365 -- restriction, and no subsequent decl instantiates its
366 -- type. (Usually, ambiguous type variables are resolved
367 -- during the generalisation step.)
368 traceTc (text "Tc8") ;
369 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
370 -- Setting the global env exposes the instances to tcSimplifyTop
371 -- Setting the local env exposes the local Ids to tcSimplifyTop,
372 -- so that we get better error messages (monomorphism restriction)
374 -- Backsubstitution. This must be done last.
375 -- Even tcSimplifyTop may do some unification.
376 traceTc (text "Tc9") ;
377 let { (tcg_env, _) = tc_envs ;
378 TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
379 tcg_rules = rules, tcg_fords = fords } = tcg_env } ;
382 (bind_ids, binds', fords', rules') <- zonkTopDecls (binds `unionBags` inst_binds)
385 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
386 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
389 tcg_fords = fords' } } ;
391 -- Make the new type env available to stuff slurped from interface files
392 writeMutVar (tcg_type_env_var tcg_env) final_type_env ;
394 -- Compare the hi-boot iface (if any) with the real thing
395 dfun_binds <- checkHiBootIface tcg_env' boot_iface ;
397 return (tcg_env' { tcg_binds = tcg_binds tcg_env' `unionBags` dfun_binds })
400 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
401 -- Loops around dealing with each top level inter-splice group
402 -- in turn, until it's dealt with the entire module
403 tc_rn_src_decls boot_details ds
404 = do { let { (first_group, group_tail) = findSplice ds } ;
405 -- If ds is [] we get ([], Nothing)
407 -- Type check the decls up to, but not including, the first splice
408 tc_envs@(tcg_env,tcl_env) <- tcRnGroup boot_details first_group ;
410 -- Bale out if errors; for example, error recovery when checking
411 -- the RHS of 'main' can mean that 'main' is not in the envt for
412 -- the subsequent checkMain test
417 -- If there is no splice, we're nearly done
419 Nothing -> do { -- Last thing: check for `main'
420 tcg_env <- checkMain ;
421 return (tcg_env, tcl_env)
424 -- If there's a splice, we must carry on
425 Just (SpliceDecl splice_expr, rest_ds) -> do {
427 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
430 -- Rename the splice expression, and get its supporting decls
431 (rn_splice_expr, splice_fvs) <- rnLExpr splice_expr ;
432 failIfErrsM ; -- Don't typecheck if renaming failed
433 rnDump (ppr rn_splice_expr) ;
435 -- Execute the splice
436 spliced_decls <- tcSpliceDecls rn_splice_expr ;
438 -- Glue them on the front of the remaining decls and loop
439 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
440 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
445 %************************************************************************
447 Compiling hs-boot source files, and
448 comparing the hi-boot interface with the real thing
450 %************************************************************************
453 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
454 tcRnHsBootDecls decls
455 = do { let { (first_group, group_tail) = findSplice decls }
458 Just stuff -> spliceInHsBootErr stuff
461 -- Rename the declarations
462 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
463 ; setGblEnv tcg_env $ do {
465 -- Todo: check no foreign decls, no rules, no default decls
467 -- Typecheck type/class decls
468 ; traceTc (text "Tc2")
469 ; let tycl_decls = hs_tyclds rn_group
470 ; tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails tycl_decls)
471 ; setGblEnv tcg_env $ do {
473 -- Typecheck instance decls
474 ; traceTc (text "Tc3")
475 ; (tcg_env, inst_infos, _binds) <- tcInstDecls1 tycl_decls (hs_instds rn_group)
476 ; setGblEnv tcg_env $ do {
478 -- Typecheck value declarations
479 ; traceTc (text "Tc5")
480 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
483 -- No simplification or zonking to do
484 ; traceTc (text "Tc7a")
485 ; gbl_env <- getGblEnv
487 -- Make the final type-env
488 -- Include the dfun_ids so that their type sigs get
489 -- are written into the interface file
490 ; let { type_env0 = tcg_type_env gbl_env
491 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
492 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
493 ; dfun_ids = map iDFunId inst_infos }
494 ; return (gbl_env { tcg_type_env = type_env2 })
497 spliceInHsBootErr (SpliceDecl (L loc _), _)
498 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
501 Once we've typechecked the body of the module, we want to compare what
502 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
505 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM (LHsBinds Id)
506 -- Compare the hi-boot file for this module (if there is one)
507 -- with the type environment we've just come up with
508 -- In the common case where there is no hi-boot file, the list
509 -- of boot_names is empty.
511 -- The bindings we return give bindings for the dfuns defined in the
512 -- hs-boot file, such as $fbEqT = $fEqT
515 (TcGblEnv { tcg_insts = local_insts, tcg_type_env = local_type_env })
516 (ModDetails { md_insts = boot_insts, md_types = boot_type_env })
517 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts)) ;
518 ; mapM_ check_one (typeEnvElts boot_type_env)
519 ; dfun_binds <- mapM check_inst boot_insts
520 ; return (unionManyBags dfun_binds) }
525 | Just real_thing <- lookupTypeEnv local_type_env name
526 = do { let boot_decl = tyThingToIfaceDecl ext_nm boot_thing
527 real_decl = tyThingToIfaceDecl ext_nm real_thing
528 ; checkTc (checkBootDecl boot_decl real_decl)
529 (bootMisMatch boot_thing boot_decl real_decl) }
530 -- The easiest way to check compatibility is to convert to
531 -- iface syntax, where we already have good comparison functions
533 = addErrTc (missingBootThing boot_thing)
535 name = getName boot_thing
537 ext_nm name = ExtPkg (nameModule name) (nameOccName name)
538 -- Just enough to compare; no versions etc needed
540 no_check name = isWiredInName name -- No checking for wired-in names. In particular,
541 -- 'error' is handled by a rather gross hack
542 -- (see comments in GHC.Err.hs-boot)
543 || name `elem` dfun_names
544 || isImplicitName name -- Has a parent, which we'll check
546 dfun_names = map getName boot_insts
549 = case [dfun | inst <- local_insts,
550 let dfun = instanceDFunId inst,
551 idType dfun `tcEqType` boot_inst_ty ] of
552 [] -> do { addErrTc (instMisMatch boot_inst); return emptyBag }
553 (dfun:_) -> return (unitBag $ noLoc $ VarBind local_boot_dfun (nlHsVar dfun))
555 boot_dfun = instanceDFunId boot_inst
556 boot_inst_ty = idType boot_dfun
557 local_boot_dfun = mkExportedLocalId (idName boot_dfun) boot_inst_ty
560 missingBootThing thing
561 = ppr thing <+> ptext SLIT("is defined in the hs-boot file, but not in the module")
562 bootMisMatch thing boot_decl real_decl
563 = ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file")
566 2 (ptext SLIT("is defined in the hs-boot file, but not in the module"))
570 %************************************************************************
572 Type-checking the top level of a module
574 %************************************************************************
576 tcRnGroup takes a bunch of top-level source-code declarations, and
578 * gets supporting declarations from interface files
581 * and augments the TcGblEnv with the results
583 In Template Haskell it may be called repeatedly for each group of
584 declarations. It expects there to be an incoming TcGblEnv in the
585 monad; it augments it and returns the new TcGblEnv.
588 tcRnGroup :: ModDetails -> HsGroup RdrName -> TcM (TcGblEnv, TcLclEnv)
589 -- Returns the variables free in the decls, for unused-binding reporting
590 tcRnGroup boot_details decls
591 = do { -- Rename the declarations
592 (tcg_env, rn_decls) <- rnTopSrcDecls decls ;
593 setGblEnv tcg_env $ do {
595 -- Typecheck the declarations
596 tcTopSrcDecls boot_details rn_decls
599 ------------------------------------------------
600 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
602 = do { -- Bring top level binders into scope
603 tcg_env <- importsFromLocalDecls group ;
604 setGblEnv tcg_env $ do {
606 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
608 -- Rename the source decls
609 (tcg_env, rn_decls) <- rnSrcDecls group ;
612 -- save the renamed syntax, if we want it
614 | Just grp <- tcg_rn_decls tcg_env
615 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
619 -- Dump trace of renaming part
620 rnDump (ppr rn_decls) ;
622 return (tcg_env', rn_decls)
625 ------------------------------------------------
626 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
627 tcTopSrcDecls boot_details
628 (HsGroup { hs_tyclds = tycl_decls,
629 hs_instds = inst_decls,
630 hs_fords = foreign_decls,
631 hs_defds = default_decls,
632 hs_ruleds = rule_decls,
633 hs_valds = val_binds })
634 = do { -- Type-check the type and class decls, and all imported decls
635 -- The latter come in via tycl_decls
636 traceTc (text "Tc2") ;
638 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
639 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
640 -- an error we'd better stop now, to avoid a cascade
642 -- Make these type and class decls available to stuff slurped from interface files
643 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
646 setGblEnv tcg_env $ do {
647 -- Source-language instances, including derivings,
648 -- and import the supporting declarations
649 traceTc (text "Tc3") ;
650 (tcg_env, inst_infos, deriv_binds) <- tcInstDecls1 tycl_decls inst_decls ;
651 setGblEnv tcg_env $ do {
653 -- Foreign import declarations next. No zonking necessary
654 -- here; we can tuck them straight into the global environment.
655 traceTc (text "Tc4") ;
656 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
657 tcExtendGlobalValEnv fi_ids $ do {
659 -- Default declarations
660 traceTc (text "Tc4a") ;
661 default_tys <- tcDefaults default_decls ;
662 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
664 -- Value declarations next
665 -- We also typecheck any extra binds that came out
666 -- of the "deriving" process (deriv_binds)
667 traceTc (text "Tc5") ;
668 (tc_val_binds, tcl_env) <- tcTopBinds (val_binds `plusHsValBinds` deriv_binds) ;
669 setLclTypeEnv tcl_env $ do {
671 -- Second pass over class and instance declarations,
672 traceTc (text "Tc6") ;
673 (inst_binds, tcl_env) <- tcInstDecls2 tycl_decls inst_infos ;
674 showLIE (text "after instDecls2") ;
677 -- They need to be zonked, so we return them
678 traceTc (text "Tc7") ;
679 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
682 rules <- tcRules rule_decls ;
685 traceTc (text "Tc7a") ;
686 tcg_env <- getGblEnv ;
687 let { all_binds = tc_val_binds `unionBags`
688 inst_binds `unionBags`
691 -- Extend the GblEnv with the (as yet un-zonked)
692 -- bindings, rules, foreign decls
693 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
694 tcg_rules = tcg_rules tcg_env ++ rules,
695 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
696 return (tcg_env', tcl_env)
701 %************************************************************************
705 %************************************************************************
708 checkMain :: TcM TcGblEnv
709 -- If we are in module Main, check that 'main' is defined.
711 = do { ghc_mode <- getGhcMode ;
712 tcg_env <- getGblEnv ;
714 let { main_mod = mainModIs dflags ;
715 main_fn = case mainFunIs dflags of {
716 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn)) ;
717 Nothing -> main_RDR_Unqual } } ;
719 check_main ghc_mode tcg_env main_mod main_fn
723 check_main ghc_mode tcg_env main_mod main_fn
725 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
729 = addErrCtxt mainCtxt $
730 do { mb_main <- lookupSrcOcc_maybe main_fn
731 -- Check that 'main' is in scope
732 -- It might be imported from another module!
734 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
738 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
739 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
740 -- :Main.main :: IO () = runMainIO main
742 ; (main_expr, ty) <- setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
745 -- The function that the RTS invokes is always :Main.main,
746 -- which we call root_main_id.
747 -- (Because GHC allows the user to have a module not called
748 -- Main as the main module, we can't rely on the main function
749 -- being called "Main.main". That's why root_main_id has a fixed
751 -- We also make root_main_id an implicit Id, by making main_name
752 -- its parent (hence (Just main_name)). That has the effect
753 -- of preventing its type and unfolding from getting out into
754 -- the interface file. Otherwise we can end up with two defns
755 -- for 'main' in the interface file!
757 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
758 (mkVarOccFS FSLIT("main"))
759 (Just main_name) (getSrcLoc main_name)
760 ; root_main_id = mkExportedLocalId root_main_name ty
761 ; main_bind = noLoc (VarBind root_main_id main_expr) }
763 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
765 tcg_dus = tcg_dus tcg_env
766 `plusDU` usesOnly (unitFV main_name)
767 -- Record the use of 'main', so that we don't
768 -- complain about it being defined but not used
772 mod = tcg_mod tcg_env
774 complain_no_main | ghc_mode == Interactive = return ()
775 | otherwise = failWithTc noMainMsg
776 -- In interactive mode, don't worry about the absence of 'main'
777 -- In other modes, fail altogether, so that we don't go on
778 -- and complain a second time when processing the export list.
780 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
781 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
782 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
785 %*********************************************************
789 %*********************************************************
793 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
794 setInteractiveContext hsc_env icxt thing_inside
796 -- Initialise the tcg_inst_env with instances
797 -- from all home modules. This mimics the more selective
798 -- call to hptInstances in tcRnModule
799 dfuns = hptInstances hsc_env (\mod -> True)
801 updGblEnv (\env -> env {
802 tcg_rdr_env = ic_rn_gbl_env icxt,
803 tcg_type_env = ic_type_env icxt,
804 tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
806 updLclEnv (\env -> env { tcl_rdr = ic_rn_local_env icxt }) $
808 do { traceTc (text "setIC" <+> ppr (ic_type_env icxt))
815 -> InteractiveContext
817 -> IO (Maybe (InteractiveContext, [Name], LHsExpr Id))
818 -- The returned [Name] is the same as the input except for
819 -- ExprStmt, in which case the returned [Name] is [itName]
821 -- The returned TypecheckedHsExpr is of type IO [ () ],
822 -- a list of the bound values, coerced to ().
824 tcRnStmt hsc_env ictxt rdr_stmt
825 = initTcPrintErrors hsc_env iNTERACTIVE $
826 setInteractiveContext hsc_env ictxt $ do {
828 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
829 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
830 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
833 -- The real work is done here
834 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
835 zonked_expr <- zonkTopLExpr tc_expr ;
836 zonked_ids <- zonkTopBndrs bound_ids ;
838 -- None of the Ids should be of unboxed type, because we
839 -- cast them all to HValues in the end!
840 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
842 traceTc (text "tcs 1") ;
843 let { -- (a) Make all the bound ids "global" ids, now that
844 -- they're notionally top-level bindings. This is
845 -- important: otherwise when we come to compile an expression
846 -- using these ids later, the byte code generator will consider
847 -- the occurrences to be free rather than global.
849 -- (b) Tidy their types; this is important, because :info may
850 -- ask to look at them, and :info expects the things it looks
851 -- up to have tidy types
852 global_ids = map globaliseAndTidy zonked_ids ;
854 -- Update the interactive context
855 rn_env = ic_rn_local_env ictxt ;
856 type_env = ic_type_env ictxt ;
858 bound_names = map idName global_ids ;
859 new_rn_env = extendLocalRdrEnv rn_env bound_names ;
861 -- Remove any shadowed bindings from the type_env;
862 -- they are inaccessible but might, I suppose, cause
863 -- a space leak if we leave them there
864 shadowed = [ n | name <- bound_names,
865 let rdr_name = mkRdrUnqual (nameOccName name),
866 Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ;
868 filtered_type_env = delListFromNameEnv type_env shadowed ;
869 new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ;
871 new_ic = ictxt { ic_rn_local_env = new_rn_env,
872 ic_type_env = new_type_env }
875 dumpOptTcRn Opt_D_dump_tc
876 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
877 text "Typechecked expr" <+> ppr zonked_expr]) ;
879 returnM (new_ic, bound_names, zonked_expr)
882 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
883 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
885 globaliseAndTidy :: Id -> Id
887 -- Give the Id a Global Name, and tidy its type
888 = setIdType (globaliseId VanillaGlobal id) tidy_type
890 tidy_type = tidyTopType (idType id)
893 Here is the grand plan, implemented in tcUserStmt
895 What you type The IO [HValue] that hscStmt returns
896 ------------- ------------------------------------
897 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
900 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
903 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
904 [NB: result not printed] bindings: [it]
906 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
907 result showable) bindings: [it]
909 expr (of non-IO type,
910 result not showable) ==> error
914 ---------------------------
915 type PlanResult = ([Id], LHsExpr Id)
916 type Plan = TcM PlanResult
918 runPlans :: [Plan] -> TcM PlanResult
919 -- Try the plans in order. If one fails (by raising an exn), try the next.
920 -- If one succeeds, take it.
921 runPlans [] = panic "runPlans"
923 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
926 mkPlan :: LStmt Name -> TcM PlanResult
927 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
928 = do { uniq <- newUnique -- is treated very specially
929 ; let fresh_it = itName uniq
930 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
931 matches = [mkMatch [] expr emptyLocalBinds]
932 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
933 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
934 (HsVar bindIOName) noSyntaxExpr
935 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
936 (HsVar thenIOName) placeHolderType
939 -- [it <- e; print it] but not if it::()
941 -- [let it = e; print it]
942 ; runPlans [ -- Plan A
943 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
944 ; it_ty <- zonkTcType (idType it_id)
945 ; ifM (isUnitTy it_ty) failM
948 -- Plan B; a naked bind statment
949 tcGhciStmts [bind_stmt],
951 -- Plan C; check that the let-binding is typeable all by itself.
952 -- If not, fail; if so, try to print it.
953 -- The two-step process avoids getting two errors: one from
954 -- the expression itself, and one from the 'print it' part
955 -- This two-step story is very clunky, alas
956 do { checkNoErrs (tcGhciStmts [let_stmt])
957 --- checkNoErrs defeats the error recovery of let-bindings
958 ; tcGhciStmts [let_stmt, print_it] }
961 mkPlan stmt@(L loc (BindStmt {}))
962 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
963 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
964 (HsVar thenIOName) placeHolderType
966 -- [stmt; print v] but not if v::()
968 ; runPlans [do { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
969 ; v_ty <- zonkTcType (idType v_id)
970 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
978 ---------------------------
979 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
981 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
982 ret_id <- tcLookupId returnIOName ; -- return @ IO
984 io_ty = mkTyConApp ioTyCon [] ;
985 ret_ty = mkListTy unitTy ;
986 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
987 tc_io_stmts stmts = tcStmts DoExpr (tcDoStmt io_ty) stmts
988 (emptyRefinement, io_ret_ty) ;
990 names = map unLoc (collectLStmtsBinders stmts) ;
992 -- mk_return builds the expression
993 -- returnIO @ [()] [coerce () x, .., coerce () z]
995 -- Despite the inconvenience of building the type applications etc,
996 -- this *has* to be done in type-annotated post-typecheck form
997 -- because we are going to return a list of *polymorphic* values
998 -- coerced to type (). If we built a *source* stmt
999 -- return [coerce x, ..., coerce z]
1000 -- then the type checker would instantiate x..z, and we wouldn't
1001 -- get their *polymorphic* values. (And we'd get ambiguity errs
1002 -- if they were overloaded, since they aren't applied to anything.)
1003 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1004 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1005 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1009 -- OK, we're ready to typecheck the stmts
1010 traceTc (text "tcs 2") ;
1011 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1012 mappM tcLookupId names ;
1013 -- Look up the names right in the middle,
1014 -- where they will all be in scope
1016 -- Simplify the context
1017 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1018 -- checkNoErrs ensures that the plan fails if context redn fails
1020 return (ids, mkHsDictLet const_binds $
1021 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1026 tcRnExpr just finds the type of an expression
1030 -> InteractiveContext
1033 tcRnExpr hsc_env ictxt rdr_expr
1034 = initTcPrintErrors hsc_env iNTERACTIVE $
1035 setInteractiveContext hsc_env ictxt $ do {
1037 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1040 -- Now typecheck the expression;
1041 -- it might have a rank-2 type (e.g. :t runST)
1042 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1043 ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1044 tcSimplifyInteractive lie_top ;
1045 qtvs' <- mappM zonkQuantifiedTyVar qtvs ;
1047 let { all_expr_ty = mkForAllTys qtvs' $
1048 mkFunTys (map idType dict_ids) $
1050 zonkTcType all_expr_ty
1053 smpl_doc = ptext SLIT("main expression")
1056 tcRnType just finds the kind of a type
1060 -> InteractiveContext
1063 tcRnType hsc_env ictxt rdr_type
1064 = initTcPrintErrors hsc_env iNTERACTIVE $
1065 setInteractiveContext hsc_env ictxt $ do {
1067 rn_type <- rnLHsType doc rdr_type ;
1070 -- Now kind-check the type
1071 (ty', kind) <- kcHsType rn_type ;
1075 doc = ptext SLIT("In GHCi input")
1081 %************************************************************************
1083 More GHCi stuff, to do with browsing and getting info
1085 %************************************************************************
1089 -- ASSUMES that the module is either in the HomePackageTable or is
1090 -- a package module with an interface on disk. If neither of these is
1091 -- true, then the result will be an error indicating the interface
1092 -- could not be found.
1093 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe NameSet)
1094 getModuleExports hsc_env mod
1095 = initTc hsc_env HsSrcFile iNTERACTIVE (tcGetModuleExports mod)
1097 tcGetModuleExports :: Module -> TcM NameSet
1098 tcGetModuleExports mod = do
1099 let doc = ptext SLIT("context for compiling statements")
1100 iface <- initIfaceTcRn $ loadSysInterface doc mod
1101 loadOrphanModules (dep_orphs (mi_deps iface))
1102 -- Load any orphan-module interfaces,
1103 -- so their instances are visible
1104 ifaceExportNames (mi_exports iface)
1106 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1107 tcRnLookupRdrName hsc_env rdr_name
1108 = initTcPrintErrors hsc_env iNTERACTIVE $
1109 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1110 lookup_rdr_name rdr_name
1112 lookup_rdr_name rdr_name = do {
1113 -- If the identifier is a constructor (begins with an
1114 -- upper-case letter), then we need to consider both
1115 -- constructor and type class identifiers.
1116 let { rdr_names = dataTcOccs rdr_name } ;
1118 -- results :: [Either Messages Name]
1119 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1121 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1122 -- The successful lookups will be (Just name)
1123 let { (warns_s, good_names) = unzip [ (msgs, name)
1124 | (msgs, Just name) <- results] ;
1125 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1127 -- Fail if nothing good happened, else add warnings
1128 if null good_names then
1129 -- No lookup succeeded, so
1130 -- pick the first error message and report it
1131 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1132 -- while the other is "X is not in scope",
1133 -- we definitely want the former; but we might pick the latter
1134 do { addMessages (head errs_s) ; failM }
1135 else -- Add deprecation warnings
1136 mapM_ addMessages warns_s ;
1142 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1143 tcRnLookupName hsc_env name
1144 = initTcPrintErrors hsc_env iNTERACTIVE $
1145 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1149 tcRnGetInfo :: HscEnv
1151 -> IO (Maybe (TyThing, Fixity, [Instance]))
1153 -- Used to implemnent :info in GHCi
1155 -- Look up a RdrName and return all the TyThings it might be
1156 -- A capitalised RdrName is given to us in the DataName namespace,
1157 -- but we want to treat it as *both* a data constructor
1158 -- *and* as a type or class constructor;
1159 -- hence the call to dataTcOccs, and we return up to two results
1160 tcRnGetInfo hsc_env name
1161 = initTcPrintErrors hsc_env iNTERACTIVE $
1162 let ictxt = hsc_IC hsc_env in
1163 setInteractiveContext hsc_env ictxt $ do
1165 -- Load the interface for all unqualified types and classes
1166 -- That way we will find all the instance declarations
1167 -- (Packages have not orphan modules, and we assume that
1168 -- in the home package all relevant modules are loaded.)
1169 loadUnqualIfaces ictxt
1171 thing <- tcLookupGlobal name
1172 fixity <- lookupFixityRn name
1173 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1174 return (thing, fixity, ispecs)
1177 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1178 -- Filter the instances by the ones whose tycons (or clases resp)
1179 -- are in scope unqualified. Otherwise we list a whole lot too many!
1180 lookupInsts print_unqual (AClass cls)
1181 = do { inst_envs <- tcGetInstEnvs
1183 | ispec <- classInstances inst_envs cls
1184 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1186 lookupInsts print_unqual (ATyCon tc)
1187 = do { eps <- getEps -- Load all instances for all classes that are
1188 -- in the type environment (which are all the ones
1189 -- we've seen in any interface file so far)
1190 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1192 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1193 , let dfun = instanceDFunId ispec
1195 , plausibleDFun print_unqual dfun ] }
1197 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1198 tc_name = tyConName tc
1200 lookupInsts print_unqual other = return []
1202 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1203 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1205 ok name | isBuiltInSyntax name = True
1206 | isExternalName name =
1207 isNothing $ fst print_unqual (nameModule name)
1211 loadUnqualIfaces :: InteractiveContext -> TcM ()
1212 -- Load the home module for everything that is in scope unqualified
1213 -- This is so that we can accurately report the instances for
1215 loadUnqualIfaces ictxt
1217 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1219 unqual_mods = [ nameModule name
1220 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1221 let name = gre_name gre,
1222 not (isInternalName name),
1223 isTcOcc (nameOccName name), -- Types and classes only
1224 unQualOK gre ] -- In scope unqualified
1225 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1229 %************************************************************************
1233 %************************************************************************
1236 rnDump :: SDoc -> TcRn ()
1237 -- Dump, with a banner, if -ddump-rn
1238 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1240 tcDump :: TcGblEnv -> TcRn ()
1242 = do { dflags <- getDOpts ;
1244 -- Dump short output if -ddump-types or -ddump-tc
1245 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1246 (dumpTcRn short_dump) ;
1248 -- Dump bindings if -ddump-tc
1249 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1252 short_dump = pprTcGblEnv env
1253 full_dump = pprLHsBinds (tcg_binds env)
1254 -- NB: foreign x-d's have undefined's in their types;
1255 -- hence can't show the tc_fords
1258 = do { dflags <- getDOpts ;
1259 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1260 (dumpTcRn (pprModGuts mod_guts)) ;
1262 -- Dump bindings if -ddump-tc
1263 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1265 full_dump = pprCoreBindings (mg_binds mod_guts)
1267 -- It's unpleasant having both pprModGuts and pprModDetails here
1268 pprTcGblEnv :: TcGblEnv -> SDoc
1269 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1270 tcg_insts = dfun_ids,
1272 tcg_imports = imports })
1273 = vcat [ ppr_types dfun_ids type_env
1274 , ppr_insts dfun_ids
1275 , vcat (map ppr rules)
1276 , ppr_gen_tycons (typeEnvTyCons type_env)
1277 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1278 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1280 pprModGuts :: ModGuts -> SDoc
1281 pprModGuts (ModGuts { mg_types = type_env,
1283 = vcat [ ppr_types [] type_env,
1287 ppr_types :: [Instance] -> TypeEnv -> SDoc
1288 ppr_types ispecs type_env
1289 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1291 dfun_ids = map instanceDFunId ispecs
1292 ids = [id | id <- typeEnvIds type_env, want_sig id]
1293 want_sig id | opt_PprStyle_Debug = True
1294 | otherwise = isLocalId id &&
1295 isExternalName (idName id) &&
1296 not (id `elem` dfun_ids)
1297 -- isLocalId ignores data constructors, records selectors etc.
1298 -- The isExternalName ignores local dictionary and method bindings
1299 -- that the type checker has invented. Top-level user-defined things
1300 -- have External names.
1302 ppr_insts :: [Instance] -> SDoc
1303 ppr_insts [] = empty
1304 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1306 ppr_sigs :: [Var] -> SDoc
1308 -- Print type signatures; sort by OccName
1309 = vcat (map ppr_sig (sortLe le_sig ids))
1311 le_sig id1 id2 = getOccName id1 <= getOccName id2
1312 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1314 ppr_rules :: [CoreRule] -> SDoc
1315 ppr_rules [] = empty
1316 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1317 nest 4 (pprRules rs),
1320 ppr_gen_tycons [] = empty
1321 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1322 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]