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)
238 (liftM2' (,) rn_exports export_ies) ;
240 -- Check whether the entire module is deprecated
241 -- This happens only once per module
242 let { mod_deprecs = checkModDeprec mod_deprec } ;
244 -- Add exports and deprecations to envt
245 let { final_env = tcg_env { tcg_exports = exports,
246 tcg_rn_exports = if save_rn_syntax then
249 tcg_dus = tcg_dus tcg_env `plusDU` usesOnly exports,
250 tcg_deprecs = tcg_deprecs tcg_env `plusDeprecs`
252 -- A module deprecation over-rides the earlier ones
255 -- Report unused names
256 reportUnusedNames export_ies final_env ;
258 -- Dump output and return
265 %************************************************************************
267 Type-checking external-core modules
269 %************************************************************************
272 tcRnExtCore :: HscEnv
274 -> IO (Messages, Maybe ModGuts)
275 -- Nothing => some error occurred
277 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
278 -- The decls are IfaceDecls; all names are original names
279 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
281 initTc hsc_env ExtCoreFile this_mod $ do {
283 let { ldecls = map noLoc decls } ;
285 -- Deal with the type declarations; first bring their stuff
286 -- into scope, then rname them, then type check them
287 tcg_env <- importsFromLocalDecls (mkFakeGroup ldecls) ;
289 setGblEnv tcg_env $ do {
291 rn_decls <- rnTyClDecls ldecls ;
294 -- Dump trace of renaming part
295 rnDump (ppr rn_decls) ;
297 -- Typecheck them all together so that
298 -- any mutually recursive types are done right
299 tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails rn_decls) ;
300 -- Make the new type env available to stuff slurped from interface files
302 setGblEnv tcg_env $ do {
304 -- Now the core bindings
305 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
309 bndrs = bindersOfBinds core_binds ;
310 my_exports = mkNameSet (map idName bndrs) ;
311 -- ToDo: export the data types also?
313 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
315 mod_guts = ModGuts { mg_module = this_mod,
317 mg_usages = [], -- ToDo: compute usage
318 mg_dir_imps = [], -- ??
319 mg_deps = noDependencies, -- ??
320 mg_exports = my_exports,
321 mg_types = final_type_env,
322 mg_insts = tcg_insts tcg_env,
324 mg_binds = core_binds,
327 mg_rdr_env = emptyGlobalRdrEnv,
328 mg_fix_env = emptyFixityEnv,
329 mg_deprecs = NoDeprecs,
333 tcCoreDump mod_guts ;
338 mkFakeGroup decls -- Rather clumsy; lots of unused fields
339 = emptyRdrGroup { hs_tyclds = decls }
343 %************************************************************************
345 Type-checking the top level of a module
347 %************************************************************************
350 tcRnSrcDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
351 -- Returns the variables free in the decls
352 -- Reason: solely to report unused imports and bindings
354 = do { -- Load the hi-boot interface for this module, if any
355 -- We do this now so that the boot_names can be passed
356 -- to tcTyAndClassDecls, because the boot_names are
357 -- automatically considered to be loop breakers
359 boot_iface <- tcHiBootIface mod ;
361 -- Do all the declarations
362 (tc_envs, lie) <- getLIE (tc_rn_src_decls boot_iface decls) ;
364 -- tcSimplifyTop deals with constant or ambiguous InstIds.
365 -- How could there be ambiguous ones? They can only arise if a
366 -- top-level decl falls under the monomorphism
367 -- restriction, and no subsequent decl instantiates its
368 -- type. (Usually, ambiguous type variables are resolved
369 -- during the generalisation step.)
370 traceTc (text "Tc8") ;
371 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
372 -- Setting the global env exposes the instances to tcSimplifyTop
373 -- Setting the local env exposes the local Ids to tcSimplifyTop,
374 -- so that we get better error messages (monomorphism restriction)
376 -- Backsubstitution. This must be done last.
377 -- Even tcSimplifyTop may do some unification.
378 traceTc (text "Tc9") ;
379 let { (tcg_env, _) = tc_envs ;
380 TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
381 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)
477 <- tcInstDecls1 tycl_decls (hs_instds rn_group) (hs_derivds rn_group)
478 ; setGblEnv tcg_env $ do {
480 -- Typecheck value declarations
481 ; traceTc (text "Tc5")
482 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
485 -- No simplification or zonking to do
486 ; traceTc (text "Tc7a")
487 ; gbl_env <- getGblEnv
489 -- Make the final type-env
490 -- Include the dfun_ids so that their type sigs get
491 -- are written into the interface file
492 ; let { type_env0 = tcg_type_env gbl_env
493 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
494 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
495 ; dfun_ids = map iDFunId inst_infos }
496 ; return (gbl_env { tcg_type_env = type_env2 })
499 spliceInHsBootErr (SpliceDecl (L loc _), _)
500 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
503 Once we've typechecked the body of the module, we want to compare what
504 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
507 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM (LHsBinds Id)
508 -- Compare the hi-boot file for this module (if there is one)
509 -- with the type environment we've just come up with
510 -- In the common case where there is no hi-boot file, the list
511 -- of boot_names is empty.
513 -- The bindings we return give bindings for the dfuns defined in the
514 -- hs-boot file, such as $fbEqT = $fEqT
517 (TcGblEnv { tcg_insts = local_insts, tcg_type_env = local_type_env })
518 (ModDetails { md_insts = boot_insts, md_types = boot_type_env })
519 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts)) ;
520 ; mapM_ check_one (typeEnvElts boot_type_env)
521 ; dfun_binds <- mapM check_inst boot_insts
522 ; return (unionManyBags dfun_binds) }
527 | Just real_thing <- lookupTypeEnv local_type_env name
528 = do { let boot_decl = tyThingToIfaceDecl ext_nm boot_thing
529 real_decl = tyThingToIfaceDecl ext_nm real_thing
530 ; checkTc (checkBootDecl boot_decl real_decl)
531 (bootMisMatch boot_thing boot_decl real_decl) }
532 -- The easiest way to check compatibility is to convert to
533 -- iface syntax, where we already have good comparison functions
535 = addErrTc (missingBootThing boot_thing)
537 name = getName boot_thing
539 ext_nm name = ExtPkg (nameModule name) (nameOccName name)
540 -- Just enough to compare; no versions etc needed
542 no_check name = isWiredInName name -- No checking for wired-in names. In particular,
543 -- 'error' is handled by a rather gross hack
544 -- (see comments in GHC.Err.hs-boot)
545 || name `elem` dfun_names
546 || isImplicitName name -- Has a parent, which we'll check
548 dfun_names = map getName boot_insts
551 = case [dfun | inst <- local_insts,
552 let dfun = instanceDFunId inst,
553 idType dfun `tcEqType` boot_inst_ty ] of
554 [] -> do { addErrTc (instMisMatch boot_inst); return emptyBag }
555 (dfun:_) -> return (unitBag $ noLoc $ VarBind local_boot_dfun (nlHsVar dfun))
557 boot_dfun = instanceDFunId boot_inst
558 boot_inst_ty = idType boot_dfun
559 local_boot_dfun = mkExportedLocalId (idName boot_dfun) boot_inst_ty
562 missingBootThing thing
563 = ppr thing <+> ptext SLIT("is defined in the hs-boot file, but not in the module")
564 bootMisMatch thing boot_decl real_decl
565 = ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file")
566 $+$ (ppr boot_decl) $+$ (ppr real_decl)
569 2 (ptext SLIT("is defined in the hs-boot file, but not in the module"))
573 %************************************************************************
575 Type-checking the top level of a module
577 %************************************************************************
579 tcRnGroup takes a bunch of top-level source-code declarations, and
581 * gets supporting declarations from interface files
584 * and augments the TcGblEnv with the results
586 In Template Haskell it may be called repeatedly for each group of
587 declarations. It expects there to be an incoming TcGblEnv in the
588 monad; it augments it and returns the new TcGblEnv.
591 tcRnGroup :: ModDetails -> HsGroup RdrName -> TcM (TcGblEnv, TcLclEnv)
592 -- Returns the variables free in the decls, for unused-binding reporting
593 tcRnGroup boot_details decls
594 = do { -- Rename the declarations
595 (tcg_env, rn_decls) <- rnTopSrcDecls decls ;
596 setGblEnv tcg_env $ do {
598 -- Typecheck the declarations
599 tcTopSrcDecls boot_details rn_decls
602 ------------------------------------------------
603 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
605 = do { -- Bring top level binders into scope
606 tcg_env <- importsFromLocalDecls group ;
607 setGblEnv tcg_env $ do {
609 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
611 -- Rename the source decls
612 (tcg_env, rn_decls) <- rnSrcDecls group ;
615 -- save the renamed syntax, if we want it
617 | Just grp <- tcg_rn_decls tcg_env
618 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
622 -- Dump trace of renaming part
623 rnDump (ppr rn_decls) ;
625 return (tcg_env', rn_decls)
628 ------------------------------------------------
629 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
630 tcTopSrcDecls boot_details
631 (HsGroup { hs_tyclds = tycl_decls,
632 hs_instds = inst_decls,
633 hs_derivds = deriv_decls,
634 hs_fords = foreign_decls,
635 hs_defds = default_decls,
636 hs_ruleds = rule_decls,
637 hs_valds = val_binds })
638 = do { -- Type-check the type and class decls, and all imported decls
639 -- The latter come in via tycl_decls
640 traceTc (text "Tc2") ;
642 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
643 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
644 -- an error we'd better stop now, to avoid a cascade
646 -- Make these type and class decls available to stuff slurped from interface files
647 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
650 setGblEnv tcg_env $ do {
651 -- Source-language instances, including derivings,
652 -- and import the supporting declarations
653 traceTc (text "Tc3") ;
654 (tcg_env, inst_infos, deriv_binds)
655 <- tcInstDecls1 tycl_decls inst_decls deriv_decls;
656 setGblEnv tcg_env $ do {
658 -- Foreign import declarations next. No zonking necessary
659 -- here; we can tuck them straight into the global environment.
660 traceTc (text "Tc4") ;
661 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
662 tcExtendGlobalValEnv fi_ids $ do {
664 -- Default declarations
665 traceTc (text "Tc4a") ;
666 default_tys <- tcDefaults default_decls ;
667 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
669 -- Value declarations next
670 -- We also typecheck any extra binds that came out
671 -- of the "deriving" process (deriv_binds)
672 traceTc (text "Tc5") ;
673 (tc_val_binds, tcl_env) <- tcTopBinds (val_binds `plusHsValBinds` deriv_binds) ;
674 setLclTypeEnv tcl_env $ do {
676 -- Second pass over class and instance declarations,
677 traceTc (text "Tc6") ;
678 (inst_binds, tcl_env) <- tcInstDecls2 tycl_decls inst_infos ;
679 showLIE (text "after instDecls2") ;
682 -- They need to be zonked, so we return them
683 traceTc (text "Tc7") ;
684 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
687 rules <- tcRules rule_decls ;
690 traceTc (text "Tc7a") ;
691 tcg_env <- getGblEnv ;
692 let { all_binds = tc_val_binds `unionBags`
693 inst_binds `unionBags`
696 -- Extend the GblEnv with the (as yet un-zonked)
697 -- bindings, rules, foreign decls
698 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
699 tcg_rules = tcg_rules tcg_env ++ rules,
700 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
701 return (tcg_env', tcl_env)
706 %************************************************************************
710 %************************************************************************
713 checkMain :: TcM TcGblEnv
714 -- If we are in module Main, check that 'main' is defined.
716 = do { ghc_mode <- getGhcMode ;
717 tcg_env <- getGblEnv ;
719 let { main_mod = mainModIs dflags ;
720 main_fn = case mainFunIs dflags of {
721 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn)) ;
722 Nothing -> main_RDR_Unqual } } ;
724 check_main ghc_mode tcg_env main_mod main_fn
728 check_main ghc_mode tcg_env main_mod main_fn
730 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
734 = addErrCtxt mainCtxt $
735 do { mb_main <- lookupSrcOcc_maybe main_fn
736 -- Check that 'main' is in scope
737 -- It might be imported from another module!
739 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
743 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
744 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
745 -- :Main.main :: IO () = runMainIO main
747 ; (main_expr, ty) <- setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
750 -- The function that the RTS invokes is always :Main.main,
751 -- which we call root_main_id.
752 -- (Because GHC allows the user to have a module not called
753 -- Main as the main module, we can't rely on the main function
754 -- being called "Main.main". That's why root_main_id has a fixed
756 -- We also make root_main_id an implicit Id, by making main_name
757 -- its parent (hence (Just main_name)). That has the effect
758 -- of preventing its type and unfolding from getting out into
759 -- the interface file. Otherwise we can end up with two defns
760 -- for 'main' in the interface file!
762 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
763 (mkVarOccFS FSLIT("main"))
764 (Just main_name) (getSrcLoc main_name)
765 ; root_main_id = mkExportedLocalId root_main_name ty
766 ; main_bind = noLoc (VarBind root_main_id main_expr) }
768 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
770 tcg_dus = tcg_dus tcg_env
771 `plusDU` usesOnly (unitFV main_name)
772 -- Record the use of 'main', so that we don't
773 -- complain about it being defined but not used
777 mod = tcg_mod tcg_env
779 complain_no_main | ghc_mode == Interactive = return ()
780 | otherwise = failWithTc noMainMsg
781 -- In interactive mode, don't worry about the absence of 'main'
782 -- In other modes, fail altogether, so that we don't go on
783 -- and complain a second time when processing the export list.
785 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
786 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
787 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
790 %*********************************************************
794 %*********************************************************
798 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
799 setInteractiveContext hsc_env icxt thing_inside
801 -- Initialise the tcg_inst_env with instances
802 -- from all home modules. This mimics the more selective
803 -- call to hptInstances in tcRnModule
804 dfuns = hptInstances hsc_env (\mod -> True)
806 updGblEnv (\env -> env {
807 tcg_rdr_env = ic_rn_gbl_env icxt,
808 tcg_type_env = ic_type_env icxt,
809 tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
811 updLclEnv (\env -> env { tcl_rdr = ic_rn_local_env icxt }) $
813 do { traceTc (text "setIC" <+> ppr (ic_type_env icxt))
820 -> InteractiveContext
822 -> IO (Maybe (InteractiveContext, [Name], LHsExpr Id))
823 -- The returned [Name] is the same as the input except for
824 -- ExprStmt, in which case the returned [Name] is [itName]
826 -- The returned TypecheckedHsExpr is of type IO [ () ],
827 -- a list of the bound values, coerced to ().
829 tcRnStmt hsc_env ictxt rdr_stmt
830 = initTcPrintErrors hsc_env iNTERACTIVE $
831 setInteractiveContext hsc_env ictxt $ do {
833 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
834 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
835 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
838 -- The real work is done here
839 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
840 zonked_expr <- zonkTopLExpr tc_expr ;
841 zonked_ids <- zonkTopBndrs bound_ids ;
843 -- None of the Ids should be of unboxed type, because we
844 -- cast them all to HValues in the end!
845 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
847 traceTc (text "tcs 1") ;
848 let { -- (a) Make all the bound ids "global" ids, now that
849 -- they're notionally top-level bindings. This is
850 -- important: otherwise when we come to compile an expression
851 -- using these ids later, the byte code generator will consider
852 -- the occurrences to be free rather than global.
854 -- (b) Tidy their types; this is important, because :info may
855 -- ask to look at them, and :info expects the things it looks
856 -- up to have tidy types
857 global_ids = map globaliseAndTidy zonked_ids ;
859 -- Update the interactive context
860 rn_env = ic_rn_local_env ictxt ;
861 type_env = ic_type_env ictxt ;
863 bound_names = map idName global_ids ;
864 new_rn_env = extendLocalRdrEnv rn_env bound_names ;
866 -- Remove any shadowed bindings from the type_env;
867 -- they are inaccessible but might, I suppose, cause
868 -- a space leak if we leave them there
869 shadowed = [ n | name <- bound_names,
870 let rdr_name = mkRdrUnqual (nameOccName name),
871 Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ;
873 filtered_type_env = delListFromNameEnv type_env shadowed ;
874 new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ;
876 new_ic = ictxt { ic_rn_local_env = new_rn_env,
877 ic_type_env = new_type_env }
880 dumpOptTcRn Opt_D_dump_tc
881 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
882 text "Typechecked expr" <+> ppr zonked_expr]) ;
884 returnM (new_ic, bound_names, zonked_expr)
887 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
888 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
890 globaliseAndTidy :: Id -> Id
892 -- Give the Id a Global Name, and tidy its type
893 = setIdType (globaliseId VanillaGlobal id) tidy_type
895 tidy_type = tidyTopType (idType id)
898 Here is the grand plan, implemented in tcUserStmt
900 What you type The IO [HValue] that hscStmt returns
901 ------------- ------------------------------------
902 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
905 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
908 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
909 [NB: result not printed] bindings: [it]
911 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
912 result showable) bindings: [it]
914 expr (of non-IO type,
915 result not showable) ==> error
919 ---------------------------
920 type PlanResult = ([Id], LHsExpr Id)
921 type Plan = TcM PlanResult
923 runPlans :: [Plan] -> TcM PlanResult
924 -- Try the plans in order. If one fails (by raising an exn), try the next.
925 -- If one succeeds, take it.
926 runPlans [] = panic "runPlans"
928 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
931 mkPlan :: LStmt Name -> TcM PlanResult
932 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
933 = do { uniq <- newUnique -- is treated very specially
934 ; let fresh_it = itName uniq
935 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
936 matches = [mkMatch [] expr emptyLocalBinds]
937 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
938 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
939 (HsVar bindIOName) noSyntaxExpr
940 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
941 (HsVar thenIOName) placeHolderType
944 -- [it <- e; print it] but not if it::()
946 -- [let it = e; print it]
947 ; runPlans [ -- Plan A
948 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
949 ; it_ty <- zonkTcType (idType it_id)
950 ; ifM (isUnitTy it_ty) failM
953 -- Plan B; a naked bind statment
954 tcGhciStmts [bind_stmt],
956 -- Plan C; check that the let-binding is typeable all by itself.
957 -- If not, fail; if so, try to print it.
958 -- The two-step process avoids getting two errors: one from
959 -- the expression itself, and one from the 'print it' part
960 -- This two-step story is very clunky, alas
961 do { checkNoErrs (tcGhciStmts [let_stmt])
962 --- checkNoErrs defeats the error recovery of let-bindings
963 ; tcGhciStmts [let_stmt, print_it] }
966 mkPlan stmt@(L loc (BindStmt {}))
967 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
968 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
969 (HsVar thenIOName) placeHolderType
971 ; print_bind_result <- doptM Opt_PrintBindResult
972 ; let print_plan = do
973 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
974 ; v_ty <- zonkTcType (idType v_id)
975 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
979 -- [stmt; print v] but not if v::()
981 ; runPlans ((if print_bind_result then [print_plan] else []) ++
982 [tcGhciStmts [stmt]])
988 ---------------------------
989 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
991 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
992 ret_id <- tcLookupId returnIOName ; -- return @ IO
994 io_ty = mkTyConApp ioTyCon [] ;
995 ret_ty = mkListTy unitTy ;
996 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
997 tc_io_stmts stmts = tcStmts DoExpr (tcDoStmt io_ty) stmts
998 (emptyRefinement, io_ret_ty) ;
1000 names = map unLoc (collectLStmtsBinders stmts) ;
1002 -- mk_return builds the expression
1003 -- returnIO @ [()] [coerce () x, .., coerce () z]
1005 -- Despite the inconvenience of building the type applications etc,
1006 -- this *has* to be done in type-annotated post-typecheck form
1007 -- because we are going to return a list of *polymorphic* values
1008 -- coerced to type (). If we built a *source* stmt
1009 -- return [coerce x, ..., coerce z]
1010 -- then the type checker would instantiate x..z, and we wouldn't
1011 -- get their *polymorphic* values. (And we'd get ambiguity errs
1012 -- if they were overloaded, since they aren't applied to anything.)
1013 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1014 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1015 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1019 -- OK, we're ready to typecheck the stmts
1020 traceTc (text "tcs 2") ;
1021 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1022 mappM tcLookupId names ;
1023 -- Look up the names right in the middle,
1024 -- where they will all be in scope
1026 -- Simplify the context
1027 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1028 -- checkNoErrs ensures that the plan fails if context redn fails
1030 return (ids, mkHsDictLet const_binds $
1031 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1036 tcRnExpr just finds the type of an expression
1040 -> InteractiveContext
1043 tcRnExpr hsc_env ictxt rdr_expr
1044 = initTcPrintErrors hsc_env iNTERACTIVE $
1045 setInteractiveContext hsc_env ictxt $ do {
1047 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1050 -- Now typecheck the expression;
1051 -- it might have a rank-2 type (e.g. :t runST)
1052 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1053 ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1054 tcSimplifyInteractive lie_top ;
1055 qtvs' <- mappM zonkQuantifiedTyVar qtvs ;
1057 let { all_expr_ty = mkForAllTys qtvs' $
1058 mkFunTys (map idType dict_ids) $
1060 zonkTcType all_expr_ty
1063 smpl_doc = ptext SLIT("main expression")
1066 tcRnType just finds the kind of a type
1070 -> InteractiveContext
1073 tcRnType hsc_env ictxt rdr_type
1074 = initTcPrintErrors hsc_env iNTERACTIVE $
1075 setInteractiveContext hsc_env ictxt $ do {
1077 rn_type <- rnLHsType doc rdr_type ;
1080 -- Now kind-check the type
1081 (ty', kind) <- kcHsType rn_type ;
1085 doc = ptext SLIT("In GHCi input")
1091 %************************************************************************
1093 More GHCi stuff, to do with browsing and getting info
1095 %************************************************************************
1099 -- ASSUMES that the module is either in the HomePackageTable or is
1100 -- a package module with an interface on disk. If neither of these is
1101 -- true, then the result will be an error indicating the interface
1102 -- could not be found.
1103 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe NameSet)
1104 getModuleExports hsc_env mod
1105 = initTc hsc_env HsSrcFile iNTERACTIVE (tcGetModuleExports mod)
1107 tcGetModuleExports :: Module -> TcM NameSet
1108 tcGetModuleExports mod = do
1109 let doc = ptext SLIT("context for compiling statements")
1110 iface <- initIfaceTcRn $ loadSysInterface doc mod
1111 loadOrphanModules (dep_orphs (mi_deps iface))
1112 -- Load any orphan-module interfaces,
1113 -- so their instances are visible
1114 ifaceExportNames (mi_exports iface)
1116 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1117 tcRnLookupRdrName hsc_env rdr_name
1118 = initTcPrintErrors hsc_env iNTERACTIVE $
1119 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1120 lookup_rdr_name rdr_name
1122 lookup_rdr_name rdr_name = do {
1123 -- If the identifier is a constructor (begins with an
1124 -- upper-case letter), then we need to consider both
1125 -- constructor and type class identifiers.
1126 let { rdr_names = dataTcOccs rdr_name } ;
1128 -- results :: [Either Messages Name]
1129 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1131 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1132 -- The successful lookups will be (Just name)
1133 let { (warns_s, good_names) = unzip [ (msgs, name)
1134 | (msgs, Just name) <- results] ;
1135 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1137 -- Fail if nothing good happened, else add warnings
1138 if null good_names then
1139 -- No lookup succeeded, so
1140 -- pick the first error message and report it
1141 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1142 -- while the other is "X is not in scope",
1143 -- we definitely want the former; but we might pick the latter
1144 do { addMessages (head errs_s) ; failM }
1145 else -- Add deprecation warnings
1146 mapM_ addMessages warns_s ;
1152 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1153 tcRnLookupName hsc_env name
1154 = initTcPrintErrors hsc_env iNTERACTIVE $
1155 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1159 tcRnGetInfo :: HscEnv
1161 -> IO (Maybe (TyThing, Fixity, [Instance]))
1163 -- Used to implemnent :info in GHCi
1165 -- Look up a RdrName and return all the TyThings it might be
1166 -- A capitalised RdrName is given to us in the DataName namespace,
1167 -- but we want to treat it as *both* a data constructor
1168 -- *and* as a type or class constructor;
1169 -- hence the call to dataTcOccs, and we return up to two results
1170 tcRnGetInfo hsc_env name
1171 = initTcPrintErrors hsc_env iNTERACTIVE $
1172 let ictxt = hsc_IC hsc_env in
1173 setInteractiveContext hsc_env ictxt $ do
1175 -- Load the interface for all unqualified types and classes
1176 -- That way we will find all the instance declarations
1177 -- (Packages have not orphan modules, and we assume that
1178 -- in the home package all relevant modules are loaded.)
1179 loadUnqualIfaces ictxt
1181 thing <- tcLookupGlobal name
1182 fixity <- lookupFixityRn name
1183 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1184 return (thing, fixity, ispecs)
1187 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1188 -- Filter the instances by the ones whose tycons (or clases resp)
1189 -- are in scope unqualified. Otherwise we list a whole lot too many!
1190 lookupInsts print_unqual (AClass cls)
1191 = do { inst_envs <- tcGetInstEnvs
1193 | ispec <- classInstances inst_envs cls
1194 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1196 lookupInsts print_unqual (ATyCon tc)
1197 = do { eps <- getEps -- Load all instances for all classes that are
1198 -- in the type environment (which are all the ones
1199 -- we've seen in any interface file so far)
1200 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1202 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1203 , let dfun = instanceDFunId ispec
1205 , plausibleDFun print_unqual dfun ] }
1207 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1208 tc_name = tyConName tc
1210 lookupInsts print_unqual other = return []
1212 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1213 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1215 ok name | isBuiltInSyntax name = True
1216 | isExternalName name =
1217 isNothing $ fst print_unqual (nameModule name)
1221 loadUnqualIfaces :: InteractiveContext -> TcM ()
1222 -- Load the home module for everything that is in scope unqualified
1223 -- This is so that we can accurately report the instances for
1225 loadUnqualIfaces ictxt
1227 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1229 unqual_mods = [ nameModule name
1230 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1231 let name = gre_name gre,
1232 not (isInternalName name),
1233 isTcOcc (nameOccName name), -- Types and classes only
1234 unQualOK gre ] -- In scope unqualified
1235 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1239 %************************************************************************
1243 %************************************************************************
1246 rnDump :: SDoc -> TcRn ()
1247 -- Dump, with a banner, if -ddump-rn
1248 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1250 tcDump :: TcGblEnv -> TcRn ()
1252 = do { dflags <- getDOpts ;
1254 -- Dump short output if -ddump-types or -ddump-tc
1255 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1256 (dumpTcRn short_dump) ;
1258 -- Dump bindings if -ddump-tc
1259 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1262 short_dump = pprTcGblEnv env
1263 full_dump = pprLHsBinds (tcg_binds env)
1264 -- NB: foreign x-d's have undefined's in their types;
1265 -- hence can't show the tc_fords
1268 = do { dflags <- getDOpts ;
1269 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1270 (dumpTcRn (pprModGuts mod_guts)) ;
1272 -- Dump bindings if -ddump-tc
1273 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1275 full_dump = pprCoreBindings (mg_binds mod_guts)
1277 -- It's unpleasant having both pprModGuts and pprModDetails here
1278 pprTcGblEnv :: TcGblEnv -> SDoc
1279 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1280 tcg_insts = dfun_ids,
1282 tcg_imports = imports })
1283 = vcat [ ppr_types dfun_ids type_env
1284 , ppr_insts dfun_ids
1285 , vcat (map ppr rules)
1286 , ppr_gen_tycons (typeEnvTyCons type_env)
1287 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1288 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1290 pprModGuts :: ModGuts -> SDoc
1291 pprModGuts (ModGuts { mg_types = type_env,
1293 = vcat [ ppr_types [] type_env,
1297 ppr_types :: [Instance] -> TypeEnv -> SDoc
1298 ppr_types ispecs type_env
1299 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1301 dfun_ids = map instanceDFunId ispecs
1302 ids = [id | id <- typeEnvIds type_env, want_sig id]
1303 want_sig id | opt_PprStyle_Debug = True
1304 | otherwise = isLocalId id &&
1305 isExternalName (idName id) &&
1306 not (id `elem` dfun_ids)
1307 -- isLocalId ignores data constructors, records selectors etc.
1308 -- The isExternalName ignores local dictionary and method bindings
1309 -- that the type checker has invented. Top-level user-defined things
1310 -- have External names.
1312 ppr_insts :: [Instance] -> SDoc
1313 ppr_insts [] = empty
1314 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1316 ppr_sigs :: [Var] -> SDoc
1318 -- Print type signatures; sort by OccName
1319 = vcat (map ppr_sig (sortLe le_sig ids))
1321 le_sig id1 id2 = getOccName id1 <= getOccName id2
1322 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1324 ppr_rules :: [CoreRule] -> SDoc
1325 ppr_rules [] = empty
1326 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1327 nest 4 (pprRules rs),
1330 ppr_gen_tycons [] = empty
1331 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1332 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]