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) <- 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")
565 $+$ (ppr boot_decl) $+$ (ppr real_decl)
568 2 (ptext SLIT("is defined in the hs-boot file, but not in the module"))
572 %************************************************************************
574 Type-checking the top level of a module
576 %************************************************************************
578 tcRnGroup takes a bunch of top-level source-code declarations, and
580 * gets supporting declarations from interface files
583 * and augments the TcGblEnv with the results
585 In Template Haskell it may be called repeatedly for each group of
586 declarations. It expects there to be an incoming TcGblEnv in the
587 monad; it augments it and returns the new TcGblEnv.
590 tcRnGroup :: ModDetails -> HsGroup RdrName -> TcM (TcGblEnv, TcLclEnv)
591 -- Returns the variables free in the decls, for unused-binding reporting
592 tcRnGroup boot_details decls
593 = do { -- Rename the declarations
594 (tcg_env, rn_decls) <- rnTopSrcDecls decls ;
595 setGblEnv tcg_env $ do {
597 -- Typecheck the declarations
598 tcTopSrcDecls boot_details rn_decls
601 ------------------------------------------------
602 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
604 = do { -- Bring top level binders into scope
605 tcg_env <- importsFromLocalDecls group ;
606 setGblEnv tcg_env $ do {
608 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
610 -- Rename the source decls
611 (tcg_env, rn_decls) <- rnSrcDecls group ;
614 -- save the renamed syntax, if we want it
616 | Just grp <- tcg_rn_decls tcg_env
617 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
621 -- Dump trace of renaming part
622 rnDump (ppr rn_decls) ;
624 return (tcg_env', rn_decls)
627 ------------------------------------------------
628 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
629 tcTopSrcDecls boot_details
630 (HsGroup { hs_tyclds = tycl_decls,
631 hs_instds = inst_decls,
632 hs_fords = foreign_decls,
633 hs_defds = default_decls,
634 hs_ruleds = rule_decls,
635 hs_valds = val_binds })
636 = do { -- Type-check the type and class decls, and all imported decls
637 -- The latter come in via tycl_decls
638 traceTc (text "Tc2") ;
640 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
641 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
642 -- an error we'd better stop now, to avoid a cascade
644 -- Make these type and class decls available to stuff slurped from interface files
645 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
648 setGblEnv tcg_env $ do {
649 -- Source-language instances, including derivings,
650 -- and import the supporting declarations
651 traceTc (text "Tc3") ;
652 (tcg_env, inst_infos, deriv_binds) <- tcInstDecls1 tycl_decls inst_decls ;
653 setGblEnv tcg_env $ do {
655 -- Foreign import declarations next. No zonking necessary
656 -- here; we can tuck them straight into the global environment.
657 traceTc (text "Tc4") ;
658 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
659 tcExtendGlobalValEnv fi_ids $ do {
661 -- Default declarations
662 traceTc (text "Tc4a") ;
663 default_tys <- tcDefaults default_decls ;
664 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
666 -- Value declarations next
667 -- We also typecheck any extra binds that came out
668 -- of the "deriving" process (deriv_binds)
669 traceTc (text "Tc5") ;
670 (tc_val_binds, tcl_env) <- tcTopBinds (val_binds `plusHsValBinds` deriv_binds) ;
671 setLclTypeEnv tcl_env $ do {
673 -- Second pass over class and instance declarations,
674 traceTc (text "Tc6") ;
675 (inst_binds, tcl_env) <- tcInstDecls2 tycl_decls inst_infos ;
676 showLIE (text "after instDecls2") ;
679 -- They need to be zonked, so we return them
680 traceTc (text "Tc7") ;
681 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
684 rules <- tcRules rule_decls ;
687 traceTc (text "Tc7a") ;
688 tcg_env <- getGblEnv ;
689 let { all_binds = tc_val_binds `unionBags`
690 inst_binds `unionBags`
693 -- Extend the GblEnv with the (as yet un-zonked)
694 -- bindings, rules, foreign decls
695 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
696 tcg_rules = tcg_rules tcg_env ++ rules,
697 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
698 return (tcg_env', tcl_env)
703 %************************************************************************
707 %************************************************************************
710 checkMain :: TcM TcGblEnv
711 -- If we are in module Main, check that 'main' is defined.
713 = do { ghc_mode <- getGhcMode ;
714 tcg_env <- getGblEnv ;
716 let { main_mod = mainModIs dflags ;
717 main_fn = case mainFunIs dflags of {
718 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn)) ;
719 Nothing -> main_RDR_Unqual } } ;
721 check_main ghc_mode tcg_env main_mod main_fn
725 check_main ghc_mode tcg_env main_mod main_fn
727 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
731 = addErrCtxt mainCtxt $
732 do { mb_main <- lookupSrcOcc_maybe main_fn
733 -- Check that 'main' is in scope
734 -- It might be imported from another module!
736 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
740 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
741 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
742 -- :Main.main :: IO () = runMainIO main
744 ; (main_expr, ty) <- setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
747 -- The function that the RTS invokes is always :Main.main,
748 -- which we call root_main_id.
749 -- (Because GHC allows the user to have a module not called
750 -- Main as the main module, we can't rely on the main function
751 -- being called "Main.main". That's why root_main_id has a fixed
753 -- We also make root_main_id an implicit Id, by making main_name
754 -- its parent (hence (Just main_name)). That has the effect
755 -- of preventing its type and unfolding from getting out into
756 -- the interface file. Otherwise we can end up with two defns
757 -- for 'main' in the interface file!
759 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
760 (mkVarOccFS FSLIT("main"))
761 (Just main_name) (getSrcLoc main_name)
762 ; root_main_id = mkExportedLocalId root_main_name ty
763 ; main_bind = noLoc (VarBind root_main_id main_expr) }
765 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
767 tcg_dus = tcg_dus tcg_env
768 `plusDU` usesOnly (unitFV main_name)
769 -- Record the use of 'main', so that we don't
770 -- complain about it being defined but not used
774 mod = tcg_mod tcg_env
776 complain_no_main | ghc_mode == Interactive = return ()
777 | otherwise = failWithTc noMainMsg
778 -- In interactive mode, don't worry about the absence of 'main'
779 -- In other modes, fail altogether, so that we don't go on
780 -- and complain a second time when processing the export list.
782 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
783 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
784 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
787 %*********************************************************
791 %*********************************************************
795 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
796 setInteractiveContext hsc_env icxt thing_inside
798 -- Initialise the tcg_inst_env with instances
799 -- from all home modules. This mimics the more selective
800 -- call to hptInstances in tcRnModule
801 dfuns = hptInstances hsc_env (\mod -> True)
803 updGblEnv (\env -> env {
804 tcg_rdr_env = ic_rn_gbl_env icxt,
805 tcg_type_env = ic_type_env icxt,
806 tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
808 updLclEnv (\env -> env { tcl_rdr = ic_rn_local_env icxt }) $
810 do { traceTc (text "setIC" <+> ppr (ic_type_env icxt))
817 -> InteractiveContext
819 -> IO (Maybe (InteractiveContext, [Name], LHsExpr Id))
820 -- The returned [Name] is the same as the input except for
821 -- ExprStmt, in which case the returned [Name] is [itName]
823 -- The returned TypecheckedHsExpr is of type IO [ () ],
824 -- a list of the bound values, coerced to ().
826 tcRnStmt hsc_env ictxt rdr_stmt
827 = initTcPrintErrors hsc_env iNTERACTIVE $
828 setInteractiveContext hsc_env ictxt $ do {
830 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
831 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
832 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
835 -- The real work is done here
836 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
837 zonked_expr <- zonkTopLExpr tc_expr ;
838 zonked_ids <- zonkTopBndrs bound_ids ;
840 -- None of the Ids should be of unboxed type, because we
841 -- cast them all to HValues in the end!
842 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
844 traceTc (text "tcs 1") ;
845 let { -- (a) Make all the bound ids "global" ids, now that
846 -- they're notionally top-level bindings. This is
847 -- important: otherwise when we come to compile an expression
848 -- using these ids later, the byte code generator will consider
849 -- the occurrences to be free rather than global.
851 -- (b) Tidy their types; this is important, because :info may
852 -- ask to look at them, and :info expects the things it looks
853 -- up to have tidy types
854 global_ids = map globaliseAndTidy zonked_ids ;
856 -- Update the interactive context
857 rn_env = ic_rn_local_env ictxt ;
858 type_env = ic_type_env ictxt ;
860 bound_names = map idName global_ids ;
861 new_rn_env = extendLocalRdrEnv rn_env bound_names ;
863 -- Remove any shadowed bindings from the type_env;
864 -- they are inaccessible but might, I suppose, cause
865 -- a space leak if we leave them there
866 shadowed = [ n | name <- bound_names,
867 let rdr_name = mkRdrUnqual (nameOccName name),
868 Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ;
870 filtered_type_env = delListFromNameEnv type_env shadowed ;
871 new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ;
873 new_ic = ictxt { ic_rn_local_env = new_rn_env,
874 ic_type_env = new_type_env }
877 dumpOptTcRn Opt_D_dump_tc
878 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
879 text "Typechecked expr" <+> ppr zonked_expr]) ;
881 returnM (new_ic, bound_names, zonked_expr)
884 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
885 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
887 globaliseAndTidy :: Id -> Id
889 -- Give the Id a Global Name, and tidy its type
890 = setIdType (globaliseId VanillaGlobal id) tidy_type
892 tidy_type = tidyTopType (idType id)
895 Here is the grand plan, implemented in tcUserStmt
897 What you type The IO [HValue] that hscStmt returns
898 ------------- ------------------------------------
899 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
902 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
905 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
906 [NB: result not printed] bindings: [it]
908 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
909 result showable) bindings: [it]
911 expr (of non-IO type,
912 result not showable) ==> error
916 ---------------------------
917 type PlanResult = ([Id], LHsExpr Id)
918 type Plan = TcM PlanResult
920 runPlans :: [Plan] -> TcM PlanResult
921 -- Try the plans in order. If one fails (by raising an exn), try the next.
922 -- If one succeeds, take it.
923 runPlans [] = panic "runPlans"
925 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
928 mkPlan :: LStmt Name -> TcM PlanResult
929 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
930 = do { uniq <- newUnique -- is treated very specially
931 ; let fresh_it = itName uniq
932 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
933 matches = [mkMatch [] expr emptyLocalBinds]
934 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
935 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
936 (HsVar bindIOName) noSyntaxExpr
937 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
938 (HsVar thenIOName) placeHolderType
941 -- [it <- e; print it] but not if it::()
943 -- [let it = e; print it]
944 ; runPlans [ -- Plan A
945 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
946 ; it_ty <- zonkTcType (idType it_id)
947 ; ifM (isUnitTy it_ty) failM
950 -- Plan B; a naked bind statment
951 tcGhciStmts [bind_stmt],
953 -- Plan C; check that the let-binding is typeable all by itself.
954 -- If not, fail; if so, try to print it.
955 -- The two-step process avoids getting two errors: one from
956 -- the expression itself, and one from the 'print it' part
957 -- This two-step story is very clunky, alas
958 do { checkNoErrs (tcGhciStmts [let_stmt])
959 --- checkNoErrs defeats the error recovery of let-bindings
960 ; tcGhciStmts [let_stmt, print_it] }
963 mkPlan stmt@(L loc (BindStmt {}))
964 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
965 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
966 (HsVar thenIOName) placeHolderType
968 ; print_bind_result <- doptM Opt_PrintBindResult
969 ; let print_plan = do
970 { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
971 ; v_ty <- zonkTcType (idType v_id)
972 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
976 -- [stmt; print v] but not if v::()
978 ; runPlans ((if print_bind_result then [print_plan] else []) ++
979 [tcGhciStmts [stmt]])
985 ---------------------------
986 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
988 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
989 ret_id <- tcLookupId returnIOName ; -- return @ IO
991 io_ty = mkTyConApp ioTyCon [] ;
992 ret_ty = mkListTy unitTy ;
993 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
994 tc_io_stmts stmts = tcStmts DoExpr (tcDoStmt io_ty) stmts
995 (emptyRefinement, io_ret_ty) ;
997 names = map unLoc (collectLStmtsBinders stmts) ;
999 -- mk_return builds the expression
1000 -- returnIO @ [()] [coerce () x, .., coerce () z]
1002 -- Despite the inconvenience of building the type applications etc,
1003 -- this *has* to be done in type-annotated post-typecheck form
1004 -- because we are going to return a list of *polymorphic* values
1005 -- coerced to type (). If we built a *source* stmt
1006 -- return [coerce x, ..., coerce z]
1007 -- then the type checker would instantiate x..z, and we wouldn't
1008 -- get their *polymorphic* values. (And we'd get ambiguity errs
1009 -- if they were overloaded, since they aren't applied to anything.)
1010 mk_return ids = nlHsApp (nlHsTyApp ret_id [ret_ty])
1011 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1012 mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy])
1016 -- OK, we're ready to typecheck the stmts
1017 traceTc (text "tcs 2") ;
1018 ((tc_stmts, ids), lie) <- getLIE $ tc_io_stmts stmts $ \ _ ->
1019 mappM tcLookupId names ;
1020 -- Look up the names right in the middle,
1021 -- where they will all be in scope
1023 -- Simplify the context
1024 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1025 -- checkNoErrs ensures that the plan fails if context redn fails
1027 return (ids, mkHsDictLet const_binds $
1028 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1033 tcRnExpr just finds the type of an expression
1037 -> InteractiveContext
1040 tcRnExpr hsc_env ictxt rdr_expr
1041 = initTcPrintErrors hsc_env iNTERACTIVE $
1042 setInteractiveContext hsc_env ictxt $ do {
1044 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1047 -- Now typecheck the expression;
1048 -- it might have a rank-2 type (e.g. :t runST)
1049 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1050 ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1051 tcSimplifyInteractive lie_top ;
1052 qtvs' <- mappM zonkQuantifiedTyVar qtvs ;
1054 let { all_expr_ty = mkForAllTys qtvs' $
1055 mkFunTys (map idType dict_ids) $
1057 zonkTcType all_expr_ty
1060 smpl_doc = ptext SLIT("main expression")
1063 tcRnType just finds the kind of a type
1067 -> InteractiveContext
1070 tcRnType hsc_env ictxt rdr_type
1071 = initTcPrintErrors hsc_env iNTERACTIVE $
1072 setInteractiveContext hsc_env ictxt $ do {
1074 rn_type <- rnLHsType doc rdr_type ;
1077 -- Now kind-check the type
1078 (ty', kind) <- kcHsType rn_type ;
1082 doc = ptext SLIT("In GHCi input")
1088 %************************************************************************
1090 More GHCi stuff, to do with browsing and getting info
1092 %************************************************************************
1096 -- ASSUMES that the module is either in the HomePackageTable or is
1097 -- a package module with an interface on disk. If neither of these is
1098 -- true, then the result will be an error indicating the interface
1099 -- could not be found.
1100 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe NameSet)
1101 getModuleExports hsc_env mod
1102 = initTc hsc_env HsSrcFile iNTERACTIVE (tcGetModuleExports mod)
1104 tcGetModuleExports :: Module -> TcM NameSet
1105 tcGetModuleExports mod = do
1106 let doc = ptext SLIT("context for compiling statements")
1107 iface <- initIfaceTcRn $ loadSysInterface doc mod
1108 loadOrphanModules (dep_orphs (mi_deps iface))
1109 -- Load any orphan-module interfaces,
1110 -- so their instances are visible
1111 ifaceExportNames (mi_exports iface)
1113 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1114 tcRnLookupRdrName hsc_env rdr_name
1115 = initTcPrintErrors hsc_env iNTERACTIVE $
1116 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1117 lookup_rdr_name rdr_name
1119 lookup_rdr_name rdr_name = do {
1120 -- If the identifier is a constructor (begins with an
1121 -- upper-case letter), then we need to consider both
1122 -- constructor and type class identifiers.
1123 let { rdr_names = dataTcOccs rdr_name } ;
1125 -- results :: [Either Messages Name]
1126 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1128 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1129 -- The successful lookups will be (Just name)
1130 let { (warns_s, good_names) = unzip [ (msgs, name)
1131 | (msgs, Just name) <- results] ;
1132 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1134 -- Fail if nothing good happened, else add warnings
1135 if null good_names then
1136 -- No lookup succeeded, so
1137 -- pick the first error message and report it
1138 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1139 -- while the other is "X is not in scope",
1140 -- we definitely want the former; but we might pick the latter
1141 do { addMessages (head errs_s) ; failM }
1142 else -- Add deprecation warnings
1143 mapM_ addMessages warns_s ;
1149 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1150 tcRnLookupName hsc_env name
1151 = initTcPrintErrors hsc_env iNTERACTIVE $
1152 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1156 tcRnGetInfo :: HscEnv
1158 -> IO (Maybe (TyThing, Fixity, [Instance]))
1160 -- Used to implemnent :info in GHCi
1162 -- Look up a RdrName and return all the TyThings it might be
1163 -- A capitalised RdrName is given to us in the DataName namespace,
1164 -- but we want to treat it as *both* a data constructor
1165 -- *and* as a type or class constructor;
1166 -- hence the call to dataTcOccs, and we return up to two results
1167 tcRnGetInfo hsc_env name
1168 = initTcPrintErrors hsc_env iNTERACTIVE $
1169 let ictxt = hsc_IC hsc_env in
1170 setInteractiveContext hsc_env ictxt $ do
1172 -- Load the interface for all unqualified types and classes
1173 -- That way we will find all the instance declarations
1174 -- (Packages have not orphan modules, and we assume that
1175 -- in the home package all relevant modules are loaded.)
1176 loadUnqualIfaces ictxt
1178 thing <- tcLookupGlobal name
1179 fixity <- lookupFixityRn name
1180 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1181 return (thing, fixity, ispecs)
1184 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1185 -- Filter the instances by the ones whose tycons (or clases resp)
1186 -- are in scope unqualified. Otherwise we list a whole lot too many!
1187 lookupInsts print_unqual (AClass cls)
1188 = do { inst_envs <- tcGetInstEnvs
1190 | ispec <- classInstances inst_envs cls
1191 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1193 lookupInsts print_unqual (ATyCon tc)
1194 = do { eps <- getEps -- Load all instances for all classes that are
1195 -- in the type environment (which are all the ones
1196 -- we've seen in any interface file so far)
1197 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1199 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1200 , let dfun = instanceDFunId ispec
1202 , plausibleDFun print_unqual dfun ] }
1204 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1205 tc_name = tyConName tc
1207 lookupInsts print_unqual other = return []
1209 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1210 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1212 ok name | isBuiltInSyntax name = True
1213 | isExternalName name =
1214 isNothing $ fst print_unqual (nameModule name)
1218 loadUnqualIfaces :: InteractiveContext -> TcM ()
1219 -- Load the home module for everything that is in scope unqualified
1220 -- This is so that we can accurately report the instances for
1222 loadUnqualIfaces ictxt
1224 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1226 unqual_mods = [ nameModule name
1227 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1228 let name = gre_name gre,
1229 not (isInternalName name),
1230 isTcOcc (nameOccName name), -- Types and classes only
1231 unQualOK gre ] -- In scope unqualified
1232 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1236 %************************************************************************
1240 %************************************************************************
1243 rnDump :: SDoc -> TcRn ()
1244 -- Dump, with a banner, if -ddump-rn
1245 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1247 tcDump :: TcGblEnv -> TcRn ()
1249 = do { dflags <- getDOpts ;
1251 -- Dump short output if -ddump-types or -ddump-tc
1252 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1253 (dumpTcRn short_dump) ;
1255 -- Dump bindings if -ddump-tc
1256 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1259 short_dump = pprTcGblEnv env
1260 full_dump = pprLHsBinds (tcg_binds env)
1261 -- NB: foreign x-d's have undefined's in their types;
1262 -- hence can't show the tc_fords
1265 = do { dflags <- getDOpts ;
1266 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1267 (dumpTcRn (pprModGuts mod_guts)) ;
1269 -- Dump bindings if -ddump-tc
1270 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1272 full_dump = pprCoreBindings (mg_binds mod_guts)
1274 -- It's unpleasant having both pprModGuts and pprModDetails here
1275 pprTcGblEnv :: TcGblEnv -> SDoc
1276 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1277 tcg_insts = dfun_ids,
1279 tcg_imports = imports })
1280 = vcat [ ppr_types dfun_ids type_env
1281 , ppr_insts dfun_ids
1282 , vcat (map ppr rules)
1283 , ppr_gen_tycons (typeEnvTyCons type_env)
1284 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1285 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1287 pprModGuts :: ModGuts -> SDoc
1288 pprModGuts (ModGuts { mg_types = type_env,
1290 = vcat [ ppr_types [] type_env,
1294 ppr_types :: [Instance] -> TypeEnv -> SDoc
1295 ppr_types ispecs type_env
1296 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1298 dfun_ids = map instanceDFunId ispecs
1299 ids = [id | id <- typeEnvIds type_env, want_sig id]
1300 want_sig id | opt_PprStyle_Debug = True
1301 | otherwise = isLocalId id &&
1302 isExternalName (idName id) &&
1303 not (id `elem` dfun_ids)
1304 -- isLocalId ignores data constructors, records selectors etc.
1305 -- The isExternalName ignores local dictionary and method bindings
1306 -- that the type checker has invented. Top-level user-defined things
1307 -- have External names.
1309 ppr_insts :: [Instance] -> SDoc
1310 ppr_insts [] = empty
1311 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1313 ppr_sigs :: [Var] -> SDoc
1315 -- Print type signatures; sort by OccName
1316 = vcat (map ppr_sig (sortLe le_sig ids))
1318 le_sig id1 id2 = getOccName id1 <= getOccName id2
1319 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1321 ppr_rules :: [CoreRule] -> SDoc
1322 ppr_rules [] = empty
1323 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1324 nest 4 (pprRules rs),
1327 ppr_gen_tycons [] = empty
1328 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1329 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]