2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[TcModule]{Typechecking a whole module}
9 mkExportEnv, getModuleContents, tcRnStmt, tcRnThing, tcRnExpr,
16 #include "HsVersions.h"
19 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
22 import CmdLineOpts ( DynFlag(..), opt_PprStyle_Debug, dopt )
23 import DriverState ( v_MainModIs, v_MainFunIs )
24 import HsSyn ( HsModule(..), HsBinds(..), MonoBinds(..), HsExpr(..),
25 HsGroup(..), SpliceDecl(..), HsExtCore(..),
28 import RdrHsSyn ( RdrNameHsModule, RdrNameHsDecl,
29 findSplice, main_RDR_Unqual )
31 import PrelNames ( runIOName, rootMainName, mAIN_Name )
32 import RdrName ( RdrName, mkRdrUnqual, emptyGlobalRdrEnv,
34 import TcHsSyn ( zonkTopDecls )
35 import TcExpr ( tcInferRho )
37 import TcType ( tidyTopType )
38 import Inst ( showLIE )
39 import TcBinds ( tcTopBinds )
40 import TcDefaults ( tcDefaults )
41 import TcEnv ( tcExtendGlobalValEnv, tcLookupGlobal )
42 import TcRules ( tcRules )
43 import TcForeign ( tcForeignImports, tcForeignExports )
44 import TcInstDcls ( tcInstDecls1, tcInstDecls2 )
45 import TcIface ( tcExtCoreBindings )
46 import TcSimplify ( tcSimplifyTop )
47 import TcTyClsDecls ( tcTyAndClassDecls )
48 import LoadIface ( loadOrphanModules )
49 import RnNames ( importsFromLocalDecls, rnImports, exportsFromAvail,
51 import RnEnv ( lookupSrcOcc_maybe )
52 import RnSource ( rnSrcDecls, rnTyClDecls, checkModDeprec )
53 import PprCore ( pprIdRules, pprCoreBindings )
54 import CoreSyn ( IdCoreRule, bindersOfBinds )
55 import ErrUtils ( mkDumpDoc, showPass )
56 import Id ( mkLocalId, isLocalId, idName, idType, setIdLocalExported )
58 import Module ( mkHomeModule, mkModuleName, moduleName, moduleEnvElts )
59 import OccName ( mkVarOcc )
60 import Name ( Name, isExternalName, getSrcLoc, getOccName )
62 import TyCon ( tyConHasGenerics )
64 import HscTypes ( ModIface, ModDetails(..), ModGuts(..),
65 HscEnv(..), ModIface(..), ModDetails(..),
66 GhciMode(..), noDependencies,
67 Deprecs( NoDeprecs ), plusDeprecs,
68 GenAvailInfo(Avail), availsToNameSet, availName,
69 ForeignStubs(NoStubs), TypeEnv, typeEnvTyCons,
70 extendTypeEnvWithIds, typeEnvIds, typeEnvTyCons,
74 import HsSyn ( HsStmtContext(..),
75 Stmt(..), Pat(VarPat),
76 collectStmtsBinders, mkSimpleMatch, placeHolderType )
77 import RdrHsSyn ( RdrNameHsExpr, RdrNameStmt )
78 import RdrName ( GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..),
79 Provenance(..), ImportSpec(..),
80 lookupLocalRdrEnv, extendLocalRdrEnv )
81 import RnHsSyn ( RenamedStmt )
82 import RnSource ( addTcgDUs )
83 import TcHsSyn ( TypecheckedHsExpr, mkHsLet, zonkTopExpr, zonkTopBndrs )
84 import TcExpr ( tcCheckRho )
85 import TcMType ( zonkTcType )
86 import TcMatches ( tcStmtsAndThen, TcStmtCtxt(..) )
87 import TcSimplify ( tcSimplifyInteractive, tcSimplifyInfer )
88 import TcType ( Type, mkForAllTys, mkFunTys, mkTyConApp, tyVarsOfType )
89 import TcEnv ( tcLookupTyCon, tcLookupId )
90 import TyCon ( DataConDetails(..) )
91 import Inst ( tcStdSyntaxName )
92 import RnExpr ( rnStmts, rnExpr )
93 import RnNames ( exportsToAvails )
94 import LoadIface ( loadSrcInterface )
95 import IfaceSyn ( IfaceDecl(..), IfaceClassOp(..), IfaceConDecl(..), IfaceExtName(..),
97 import IfaceEnv ( tcIfaceGlobal )
98 import RnEnv ( lookupOccRn, dataTcOccs, lookupFixityRn )
99 import Id ( Id, isImplicitId )
100 import MkId ( unsafeCoerceId )
101 import TysWiredIn ( mkListTy, unitTy )
102 import IdInfo ( GlobalIdDetails(..) )
103 import SrcLoc ( interactiveSrcLoc )
104 import Var ( setGlobalIdDetails )
105 import Name ( nameOccName, nameModuleName )
106 import NameEnv ( delListFromNameEnv )
107 import PrelNames ( iNTERACTIVE, ioTyConName, printName, monadNames, itName, returnIOName )
108 import Module ( ModuleName, lookupModuleEnvByName )
109 import HscTypes ( InteractiveContext(..),
110 HomeModInfo(..), typeEnvElts,
111 TyThing(..), availNames, icPrintUnqual )
112 import BasicTypes ( RecFlag(..), Fixity )
113 import Panic ( ghcError, GhcException(..) )
116 import FastString ( mkFastString )
117 import Util ( sortLt )
122 %************************************************************************
124 Typecheck and rename a module
126 %************************************************************************
132 -> IO (Maybe TcGblEnv)
135 (HsModule maybe_mod exports import_decls local_decls mod_deprec loc)
136 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
138 let { this_mod = case maybe_mod of
139 Nothing -> mkHomeModule mAIN_Name -- 'module M where' is omitted
140 Just mod -> mod } ; -- The normal case
142 initTc hsc_env this_mod $ addSrcLoc loc $
143 do { -- Deal with imports; sets tcg_rdr_env, tcg_imports
144 (rdr_env, imports) <- rnImports import_decls ;
145 updGblEnv ( \ gbl -> gbl { tcg_rdr_env = rdr_env,
146 tcg_imports = tcg_imports gbl `plusImportAvails` imports })
148 traceRn (text "rn1" <+> ppr (imp_dep_mods imports)) ;
149 -- Fail if there are any errors so far
150 -- The error printing (if needed) takes advantage
151 -- of the tcg_env we have now set
154 -- Load any orphan-module interfaces, so that
155 -- their rules and instance decls will be found
156 loadOrphanModules (imp_orphs imports) ;
158 traceRn (text "rn1a") ;
159 -- Rename and type check the declarations
160 tcg_env <- tcRnSrcDecls local_decls ;
161 setGblEnv tcg_env $ do {
163 traceRn (text "rn3") ;
165 -- Process the export list
166 export_avails <- exportsFromAvail maybe_mod exports ;
168 -- Get any supporting decls for the exports that have not already
169 -- been sucked in for the declarations in the body of the module.
170 -- (This can happen if something is imported only to be re-exported.)
172 -- Importing these supporting declarations is required
173 -- *only* to gether usage information
174 -- (see comments with MkIface.mkImportInfo for why)
175 -- We don't need the results, but sucking them in may side-effect
176 -- the ExternalPackageState, apart from recording usage
177 mappM (tcLookupGlobal . availName) export_avails ;
179 -- Check whether the entire module is deprecated
180 -- This happens only once per module
181 let { mod_deprecs = checkModDeprec mod_deprec } ;
183 -- Add exports and deprecations to envt
184 let { export_fvs = availsToNameSet export_avails ;
185 final_env = tcg_env { tcg_exports = export_avails,
186 tcg_dus = tcg_dus tcg_env `plusDU` usesOnly export_fvs,
187 tcg_deprecs = tcg_deprecs tcg_env `plusDeprecs`
189 -- A module deprecation over-rides the earlier ones
192 -- Report unused names
193 reportUnusedNames final_env ;
195 -- Dump output and return
202 %************************************************************************
204 The interactive interface
206 %************************************************************************
211 -> InteractiveContext
213 -> IO (Maybe (InteractiveContext, [Name], TypecheckedHsExpr))
214 -- The returned [Name] is the same as the input except for
215 -- ExprStmt, in which case the returned [Name] is [itName]
217 -- The returned TypecheckedHsExpr is of type IO [ () ],
218 -- a list of the bound values, coerced to ().
220 tcRnStmt hsc_env ictxt rdr_stmt
221 = initTc hsc_env iNTERACTIVE $
222 setInteractiveContext ictxt $ do {
224 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
225 ([rn_stmt], fvs) <- rnStmts DoExpr [rdr_stmt] ;
226 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
229 -- The real work is done here
230 (bound_ids, tc_expr) <- tcUserStmt rn_stmt ;
232 traceTc (text "tcs 1") ;
233 let { -- Make all the bound ids "global" ids, now that
234 -- they're notionally top-level bindings. This is
235 -- important: otherwise when we come to compile an expression
236 -- using these ids later, the byte code generator will consider
237 -- the occurrences to be free rather than global.
238 global_ids = map globaliseId bound_ids ;
239 globaliseId id = setGlobalIdDetails id VanillaGlobal ;
241 -- Update the interactive context
242 rn_env = ic_rn_local_env ictxt ;
243 type_env = ic_type_env ictxt ;
245 bound_names = map idName global_ids ;
246 new_rn_env = extendLocalRdrEnv rn_env bound_names ;
248 -- Remove any shadowed bindings from the type_env;
249 -- they are inaccessible but might, I suppose, cause
250 -- a space leak if we leave them there
251 shadowed = [ n | name <- bound_names,
252 let rdr_name = mkRdrUnqual (nameOccName name),
253 Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ;
255 filtered_type_env = delListFromNameEnv type_env shadowed ;
256 new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ;
258 new_ic = ictxt { ic_rn_local_env = new_rn_env,
259 ic_type_env = new_type_env }
262 dumpOptTcRn Opt_D_dump_tc
263 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
264 text "Typechecked expr" <+> ppr tc_expr]) ;
266 returnM (new_ic, bound_names, tc_expr)
271 Here is the grand plan, implemented in tcUserStmt
273 What you type The IO [HValue] that hscStmt returns
274 ------------- ------------------------------------
275 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
278 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
281 expr (of IO type) ==> expr >>= \ v -> return [coerce HVal v]
282 [NB: result not printed] bindings: [it]
284 expr (of non-IO type, ==> let v = expr in print v >> return [coerce HVal v]
285 result showable) bindings: [it]
287 expr (of non-IO type,
288 result not showable) ==> error
292 ---------------------------
293 tcUserStmt :: RenamedStmt -> TcM ([Id], TypecheckedHsExpr)
294 tcUserStmt (ExprStmt expr _ loc)
295 = newUnique `thenM` \ uniq ->
297 fresh_it = itName uniq
298 the_bind = FunMonoBind fresh_it False
299 [ mkSimpleMatch [] expr placeHolderType loc ] loc
301 tryTcLIE_ (do { -- Try this if the other fails
302 traceTc (text "tcs 1b") ;
304 LetStmt (MonoBind the_bind [] NonRecursive),
305 ExprStmt (HsApp (HsVar printName) (HsVar fresh_it))
306 placeHolderType loc] })
307 (do { -- Try this first
308 traceTc (text "tcs 1a") ;
309 tc_stmts [BindStmt (VarPat fresh_it) expr loc] })
311 tcUserStmt stmt = tc_stmts [stmt]
313 ---------------------------
315 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
317 ret_ty = mkListTy unitTy ;
318 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
320 names = collectStmtsBinders stmts ;
322 stmt_ctxt = SC { sc_what = DoExpr,
324 sc_body = check_body,
327 check_rhs rhs rhs_ty = tcCheckRho rhs (mkTyConApp ioTyCon [rhs_ty]) ;
328 check_body body = tcCheckRho body io_ret_ty ;
330 -- mk_return builds the expression
331 -- returnIO @ [()] [coerce () x, .., coerce () z]
333 -- Despite the inconvenience of building the type applications etc,
334 -- this *has* to be done in type-annotated post-typecheck form
335 -- because we are going to return a list of *polymorphic* values
336 -- coerced to type (). If we built a *source* stmt
337 -- return [coerce x, ..., coerce z]
338 -- then the type checker would instantiate x..z, and we wouldn't
339 -- get their *polymorphic* values. (And we'd get ambiguity errs
340 -- if they were overloaded, since they aren't applied to anything.)
341 mk_return ret_id ids = HsApp (TyApp (HsVar ret_id) [ret_ty])
342 (ExplicitList unitTy (map mk_item ids)) ;
343 mk_item id = HsApp (TyApp (HsVar unsafeCoerceId) [idType id, unitTy])
346 io_ty = mkTyConApp ioTyCon []
349 -- OK, we're ready to typecheck the stmts
350 traceTc (text "tcs 2") ;
351 ((ids, tc_expr), lie) <- getLIE $ do {
352 (ids, tc_stmts) <- tcStmtsAndThen combine stmt_ctxt stmts $
354 -- Look up the names right in the middle,
355 -- where they will all be in scope
356 ids <- mappM tcLookupId names ;
357 ret_id <- tcLookupId returnIOName ; -- return @ IO
358 return (ids, [ResultStmt (mk_return ret_id ids) interactiveSrcLoc]) } ;
360 io_ids <- mappM (tcStdSyntaxName DoOrigin io_ty) monadNames ;
361 return (ids, HsDo DoExpr tc_stmts io_ids io_ret_ty interactiveSrcLoc)
364 -- Simplify the context right here, so that we fail
365 -- if there aren't enough instances. Notably, when we see
367 -- we use recoverTc_ to try it <- e
368 -- and then let it = e
369 -- It's the simplify step that rejects the first.
370 traceTc (text "tcs 3") ;
371 const_binds <- tcSimplifyInteractive lie ;
373 -- Build result expression and zonk it
374 let { expr = mkHsLet const_binds tc_expr } ;
375 zonked_expr <- zonkTopExpr expr ;
376 zonked_ids <- zonkTopBndrs ids ;
378 return (zonked_ids, zonked_expr)
381 combine stmt (ids, stmts) = (ids, stmt:stmts)
385 tcRnExpr just finds the type of an expression
389 -> InteractiveContext
392 tcRnExpr hsc_env ictxt rdr_expr
393 = initTc hsc_env iNTERACTIVE $
394 setInteractiveContext ictxt $ do {
396 (rn_expr, fvs) <- rnExpr rdr_expr ;
399 -- Now typecheck the expression;
400 -- it might have a rank-2 type (e.g. :t runST)
401 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
402 ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
403 tcSimplifyInteractive lie_top ;
405 let { all_expr_ty = mkForAllTys qtvs $
406 mkFunTys (map idType dict_ids) $
408 zonkTcType all_expr_ty
411 smpl_doc = ptext SLIT("main expression")
417 -> InteractiveContext
419 -> IO (Maybe [(IfaceDecl, Fixity)])
420 -- Look up a RdrName and return all the TyThings it might be
421 -- A capitalised RdrName is given to us in the DataName namespace,
422 -- but we want to treat it as *both* a data constructor
423 -- *and* as a type or class constructor;
424 -- hence the call to dataTcOccs, and we return up to two results
425 tcRnThing hsc_env ictxt rdr_name
426 = initTc hsc_env iNTERACTIVE $
427 setInteractiveContext ictxt $ do {
429 -- If the identifier is a constructor (begins with an
430 -- upper-case letter), then we need to consider both
431 -- constructor and type class identifiers.
432 let { rdr_names = dataTcOccs rdr_name } ;
434 -- results :: [(Messages, Maybe Name)]
435 results <- mapM (tryTc . lookupOccRn) rdr_names ;
437 -- The successful lookups will be (Just name)
438 let { (warns_s, good_names) = unzip [ (msgs, name)
439 | (msgs, Just name) <- results] ;
440 errs_s = [msgs | (msgs, Nothing) <- results] } ;
442 -- Fail if nothing good happened, else add warnings
443 if null good_names then
444 -- No lookup succeeded, so
445 -- pick the first error message and report it
446 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
447 -- while the other is "X is not in scope",
448 -- we definitely want the former; but we might pick the latter
449 do { addMessages (head errs_s) ; failM }
450 else -- Add deprecation warnings
451 mapM_ addMessages warns_s ;
453 -- And lookup up the entities
454 mapM do_one good_names
457 do_one name = do { thing <- tcLookupGlobal name
458 ; fixity <- lookupFixityRn name
459 ; return (toIfaceDecl ictxt thing, fixity) }
461 toIfaceDecl :: InteractiveContext -> TyThing -> IfaceDecl
462 toIfaceDecl ictxt thing
463 = tyThingToIfaceDecl True {- Discard IdInfo -} ext_nm thing
465 unqual = icPrintUnqual ictxt
466 ext_nm n | unqual n = LocalTop (nameOccName n) -- What a hack
467 | otherwise = ExtPkg (nameModuleName n) (nameOccName n)
472 setInteractiveContext :: InteractiveContext -> TcRn a -> TcRn a
473 setInteractiveContext icxt thing_inside
474 = traceTc (text "setIC" <+> ppr (ic_type_env icxt)) `thenM_`
475 (updGblEnv (\env -> env {tcg_rdr_env = ic_rn_gbl_env icxt,
476 tcg_type_env = ic_type_env icxt}) $
477 updLclEnv (\env -> env {tcl_rdr = ic_rn_local_env icxt}) $
482 %************************************************************************
484 Type-checking external-core modules
486 %************************************************************************
489 tcRnExtCore :: HscEnv
491 -> IO (Maybe ModGuts)
492 -- Nothing => some error occurred
494 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
495 -- The decls are IfaceDecls; all names are original names
496 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
498 initTc hsc_env this_mod $ do {
500 -- Deal with the type declarations; first bring their stuff
501 -- into scope, then rname them, then type check them
502 (rdr_env, imports) <- importsFromLocalDecls (mkFakeGroup decls) ;
504 updGblEnv (\gbl -> gbl { tcg_rdr_env = rdr_env `plusGlobalRdrEnv` tcg_rdr_env gbl,
505 tcg_imports = imports `plusImportAvails` tcg_imports gbl })
508 rn_decls <- rnTyClDecls decls ;
511 -- Dump trace of renaming part
512 rnDump (ppr rn_decls) ;
514 -- Typecheck them all together so that
515 -- any mutually recursive types are done right
516 tcg_env <- checkNoErrs (tcTyAndClassDecls rn_decls) ;
517 -- Make the new type env available to stuff slurped from interface files
519 setGblEnv tcg_env $ do {
521 -- Now the core bindings
522 core_binds <- initIfaceExtCore (tcExtCoreBindings this_mod src_binds) ;
526 bndrs = bindersOfBinds core_binds ;
527 my_exports = map (Avail . idName) bndrs ;
528 -- ToDo: export the data types also?
530 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
532 mod_guts = ModGuts { mg_module = this_mod,
533 mg_usages = [], -- ToDo: compute usage
534 mg_dir_imps = [], -- ??
535 mg_deps = noDependencies, -- ??
536 mg_exports = my_exports,
537 mg_types = final_type_env,
538 mg_insts = tcg_insts tcg_env,
540 mg_binds = core_binds,
543 mg_rdr_env = emptyGlobalRdrEnv,
544 mg_fix_env = emptyFixityEnv,
545 mg_deprecs = NoDeprecs,
549 tcCoreDump mod_guts ;
554 mkFakeGroup decls -- Rather clumsy; lots of unused fields
555 = HsGroup { hs_tyclds = decls, -- This is the one we want
556 hs_valds = EmptyBinds, hs_fords = [],
557 hs_instds = [], hs_fixds = [], hs_depds = [],
558 hs_ruleds = [], hs_defds = [] }
562 %************************************************************************
564 Type-checking the top level of a module
566 %************************************************************************
569 tcRnSrcDecls :: [RdrNameHsDecl] -> TcM TcGblEnv
570 -- Returns the variables free in the decls
571 -- Reason: solely to report unused imports and bindings
573 = do { -- Do all the declarations
574 (tc_envs, lie) <- getLIE (tc_rn_src_decls decls) ;
576 -- tcSimplifyTop deals with constant or ambiguous InstIds.
577 -- How could there be ambiguous ones? They can only arise if a
578 -- top-level decl falls under the monomorphism
579 -- restriction, and no subsequent decl instantiates its
580 -- type. (Usually, ambiguous type variables are resolved
581 -- during the generalisation step.)
582 traceTc (text "Tc8") ;
583 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
584 -- Setting the global env exposes the instances to tcSimplifyTop
585 -- Setting the local env exposes the local Ids to tcSimplifyTop,
586 -- so that we get better error messages (monomorphism restriction)
588 -- Backsubstitution. This must be done last.
589 -- Even tcSimplifyTop may do some unification.
590 traceTc (text "Tc9") ;
591 let { (tcg_env, _) = tc_envs ;
592 TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
593 tcg_rules = rules, tcg_fords = fords } = tcg_env } ;
595 (bind_ids, binds', fords', rules') <- zonkTopDecls (binds `andMonoBinds` inst_binds)
598 let { final_type_env = extendTypeEnvWithIds type_env bind_ids } ;
600 -- Make the new type env available to stuff slurped from interface files
601 writeMutVar (tcg_type_env_var tcg_env) final_type_env ;
603 return (tcg_env { tcg_type_env = final_type_env,
604 tcg_binds = binds', tcg_rules = rules', tcg_fords = fords' })
607 tc_rn_src_decls :: [RdrNameHsDecl] -> TcM (TcGblEnv, TcLclEnv)
608 -- Loops around dealing with each top level inter-splice group
609 -- in turn, until it's dealt with the entire module
611 = do { let { (first_group, group_tail) = findSplice ds } ;
612 -- If ds is [] we get ([], Nothing)
614 -- Type check the decls up to, but not including, the first splice
615 tc_envs@(tcg_env,tcl_env) <- tcRnGroup first_group ;
617 -- Bale out if errors; for example, error recovery when checking
618 -- the RHS of 'main' can mean that 'main' is not in the envt for
619 -- the subsequent checkMain test
624 -- If there is no splice, we're nearly done
626 Nothing -> do { -- Last thing: check for `main'
627 tcg_env <- checkMain ;
628 return (tcg_env, tcl_env)
631 -- If there's a splice, we must carry on
632 Just (SpliceDecl splice_expr splice_loc, rest_ds) -> do {
634 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
637 -- Rename the splice expression, and get its supporting decls
638 (rn_splice_expr, splice_fvs) <- addSrcLoc splice_loc $
640 failIfErrsM ; -- Don't typecheck if renaming failed
642 -- Execute the splice
643 spliced_decls <- tcSpliceDecls rn_splice_expr ;
645 -- Glue them on the front of the remaining decls and loop
646 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
647 tc_rn_src_decls (spliced_decls ++ rest_ds)
653 %************************************************************************
655 Type-checking the top level of a module
657 %************************************************************************
659 tcRnGroup takes a bunch of top-level source-code declarations, and
661 * gets supporting declarations from interface files
664 * and augments the TcGblEnv with the results
666 In Template Haskell it may be called repeatedly for each group of
667 declarations. It expects there to be an incoming TcGblEnv in the
668 monad; it augments it and returns the new TcGblEnv.
671 tcRnGroup :: HsGroup RdrName -> TcM (TcGblEnv, TcLclEnv)
672 -- Returns the variables free in the decls, for unused-binding reporting
674 = do { -- Rename the declarations
675 (tcg_env, rn_decls) <- rnTopSrcDecls decls ;
676 setGblEnv tcg_env $ do {
678 -- Typecheck the declarations
679 tcTopSrcDecls rn_decls
682 ------------------------------------------------
683 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
685 = do { -- Bring top level binders into scope
686 (rdr_env, imports) <- importsFromLocalDecls group ;
687 updGblEnv (\gbl -> gbl { tcg_rdr_env = rdr_env `plusGlobalRdrEnv` tcg_rdr_env gbl,
688 tcg_imports = imports `plusImportAvails` tcg_imports gbl })
691 traceRn (ptext SLIT("rnTopSrcDecls") <+> ppr rdr_env) ;
692 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
694 -- Rename the source decls
695 (tcg_env, rn_decls) <- rnSrcDecls group ;
698 -- Dump trace of renaming part
699 rnDump (ppr rn_decls) ;
701 return (tcg_env, rn_decls)
704 ------------------------------------------------
705 tcTopSrcDecls :: HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
707 (HsGroup { hs_tyclds = tycl_decls,
708 hs_instds = inst_decls,
709 hs_fords = foreign_decls,
710 hs_defds = default_decls,
711 hs_ruleds = rule_decls,
712 hs_valds = val_binds })
713 = do { -- Type-check the type and class decls, and all imported decls
714 -- The latter come in via tycl_decls
715 traceTc (text "Tc2") ;
717 tcg_env <- checkNoErrs (tcTyAndClassDecls tycl_decls) ;
718 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
719 -- an error we'd better stop now, to avoid a cascade
721 -- Make these type and class decls available to stuff slurped from interface files
722 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
725 setGblEnv tcg_env $ do {
726 -- Source-language instances, including derivings,
727 -- and import the supporting declarations
728 traceTc (text "Tc3") ;
729 (tcg_env, inst_infos, deriv_binds) <- tcInstDecls1 tycl_decls inst_decls ;
730 setGblEnv tcg_env $ do {
732 -- Foreign import declarations next. No zonking necessary
733 -- here; we can tuck them straight into the global environment.
734 traceTc (text "Tc4") ;
735 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
736 tcExtendGlobalValEnv fi_ids $ do {
738 -- Default declarations
739 traceTc (text "Tc4a") ;
740 default_tys <- tcDefaults default_decls ;
741 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
743 -- Value declarations next
744 -- We also typecheck any extra binds that came out
745 -- of the "deriving" process (deriv_binds)
746 traceTc (text "Tc5") ;
747 (tc_val_binds, lcl_env) <- tcTopBinds (val_binds `ThenBinds` deriv_binds) ;
748 setLclTypeEnv lcl_env $ do {
750 -- Second pass over class and instance declarations,
751 traceTc (text "Tc6") ;
752 (tcl_env, inst_binds) <- tcInstDecls2 tycl_decls inst_infos ;
753 showLIE (text "after instDecls2") ;
756 -- They need to be zonked, so we return them
757 traceTc (text "Tc7") ;
758 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
761 rules <- tcRules rule_decls ;
764 traceTc (text "Tc7a") ;
765 tcg_env <- getGblEnv ;
766 let { all_binds = tc_val_binds `AndMonoBinds`
767 inst_binds `AndMonoBinds`
770 -- Extend the GblEnv with the (as yet un-zonked)
771 -- bindings, rules, foreign decls
772 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `andMonoBinds` all_binds,
773 tcg_rules = tcg_rules tcg_env ++ rules,
774 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
775 return (tcg_env', lcl_env)
780 %*********************************************************
782 mkGlobalContext: make up an interactive context
784 Used for initialising the lexical environment
785 of the interactive read-eval-print loop
787 %*********************************************************
791 mkExportEnv :: HscEnv -> [ModuleName] -- Expose these modules' exports only
794 mkExportEnv hsc_env exports
795 = do { mb_envs <- initTc hsc_env iNTERACTIVE $
796 mappM getModuleExports exports
798 Just envs -> return (foldr plusGlobalRdrEnv emptyGlobalRdrEnv envs)
799 Nothing -> return emptyGlobalRdrEnv
800 -- Some error; initTc will have printed it
803 getModuleExports :: ModuleName -> TcM GlobalRdrEnv
805 = do { iface <- load_iface mod
806 ; avails <- exportsToAvails (mi_exports iface)
807 ; let { gres = [ GRE { gre_name = name, gre_prov = vanillaProv mod,
808 gre_deprec = mi_dep_fn iface name }
809 | avail <- avails, name <- availNames avail ] }
810 ; returnM (mkGlobalRdrEnv gres) }
812 vanillaProv :: ModuleName -> Provenance
813 -- We're building a GlobalRdrEnv as if the user imported
814 -- all the specified modules into the global interactive module
815 vanillaProv mod = Imported [ImportSpec mod mod False interactiveSrcLoc] False
821 -> InteractiveContext
822 -> ModuleName -- Module to inspect
823 -> Bool -- Grab just the exports, or the whole toplev
824 -> IO (Maybe [IfaceDecl])
826 getModuleContents hsc_env ictxt mod exports_only
827 = initTc hsc_env iNTERACTIVE (get_mod_contents exports_only)
829 get_mod_contents exports_only
830 | not exports_only -- We want the whole top-level type env
831 -- so it had better be a home module
833 ; case lookupModuleEnvByName hpt mod of
834 Just mod_info -> return (map (toIfaceDecl ictxt) $
837 md_types (hm_details mod_info))
838 Nothing -> ghcError (ProgramError (showSDoc (noRdrEnvErr mod)))
839 -- This is a system error; the module should be in the HPT
842 | otherwise -- Want the exports only
843 = do { iface <- load_iface mod
844 ; avails <- exportsToAvails (mi_exports iface)
845 ; mappM get_decl avails
849 = do { thing <- tcLookupGlobal (availName avail)
850 ; return (filter_decl (availOccs avail) (toIfaceDecl ictxt thing)) }
852 ---------------------
853 filter_decl occs decl@(IfaceClass {ifSigs = sigs})
854 = decl { ifSigs = filter (keep_sig occs) sigs }
855 filter_decl occs decl@(IfaceData {ifCons = DataCons cons})
856 = decl { ifCons = DataCons (filter (keep_con occs) cons) }
857 filter_decl occs decl
860 keep_sig occs (IfaceClassOp occ _ _) = occ `elem` occs
861 keep_con occs (IfaceConDecl occ _ _ _ _ _) = occ `elem` occs
863 availOccs avail = map nameOccName (availNames avail)
865 wantToSee (AnId id) = not (isImplicitId id)
866 wantToSee (ADataCon _) = False -- They'll come via their TyCon
869 ---------------------
870 load_iface mod = loadSrcInterface doc mod False {- Not boot iface -}
872 doc = ptext SLIT("context for compiling statements")
874 ---------------------
875 noRdrEnvErr mod = ptext SLIT("No top-level environment available for module")
880 %************************************************************************
884 %************************************************************************
888 = do { ghci_mode <- getGhciMode ;
889 tcg_env <- getGblEnv ;
891 mb_main_mod <- readMutVar v_MainModIs ;
892 mb_main_fn <- readMutVar v_MainFunIs ;
893 let { main_mod = case mb_main_mod of {
894 Just mod -> mkModuleName mod ;
895 Nothing -> mAIN_Name } ;
896 main_fn = case mb_main_fn of {
897 Just fn -> mkRdrUnqual (mkVarOcc (mkFastString fn)) ;
898 Nothing -> main_RDR_Unqual } } ;
900 check_main ghci_mode tcg_env main_mod main_fn
904 check_main ghci_mode tcg_env main_mod main_fn
905 -- If we are in module Main, check that 'main' is defined.
906 -- It may be imported from another module!
908 -- ToDo: We have to return the main_name separately, because it's a
909 -- bona fide 'use', and should be recorded as such, but the others
912 -- Blimey: a whole page of code to do this...
913 | mod_name /= main_mod
917 = addErrCtxt mainCtxt $
918 do { mb_main <- lookupSrcOcc_maybe main_fn
919 -- Check that 'main' is in scope
920 -- It might be imported from another module!
922 Nothing -> do { complain_no_main
925 { let { rhs = HsApp (HsVar runIOName) (HsVar main_name) }
926 -- :Main.main :: IO () = runIO main
928 ; (main_expr, ty) <- addSrcLoc (getSrcLoc main_name) $
931 ; let { root_main_id = setIdLocalExported (mkLocalId rootMainName ty) ;
932 main_bind = VarMonoBind root_main_id main_expr }
934 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
935 `andMonoBinds` main_bind,
936 tcg_dus = tcg_dus tcg_env
937 `plusDU` usesOnly (unitFV main_name)
941 mod_name = moduleName (tcg_mod tcg_env)
943 complain_no_main | ghci_mode == Interactive = return ()
944 | otherwise = failWithTc noMainMsg
945 -- In interactive mode, don't worry about the absence of 'main'
946 -- In other modes, fail altogether, so that we don't go on
947 -- and complain a second time when processing the export list.
949 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
950 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
951 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
955 %************************************************************************
959 %************************************************************************
962 rnDump :: SDoc -> TcRn ()
963 -- Dump, with a banner, if -ddump-rn
964 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
966 tcDump :: TcGblEnv -> TcRn ()
968 = do { dflags <- getDOpts ;
970 -- Dump short output if -ddump-types or -ddump-tc
971 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
972 (dumpTcRn short_dump) ;
974 -- Dump bindings if -ddump-tc
975 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
978 short_dump = pprTcGblEnv env
979 full_dump = ppr (tcg_binds env)
980 -- NB: foreign x-d's have undefined's in their types;
981 -- hence can't show the tc_fords
984 = do { dflags <- getDOpts ;
985 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
986 (dumpTcRn (pprModGuts mod_guts)) ;
988 -- Dump bindings if -ddump-tc
989 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
991 full_dump = pprCoreBindings (mg_binds mod_guts)
993 -- It's unpleasant having both pprModGuts and pprModDetails here
994 pprTcGblEnv :: TcGblEnv -> SDoc
995 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
996 tcg_insts = dfun_ids,
998 tcg_imports = imports })
999 = vcat [ ppr_types dfun_ids type_env
1000 , ppr_insts dfun_ids
1001 , vcat (map ppr rules)
1002 , ppr_gen_tycons (typeEnvTyCons type_env)
1003 , ptext SLIT("Dependent modules:") <+> ppr (moduleEnvElts (imp_dep_mods imports))
1004 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1006 pprModGuts :: ModGuts -> SDoc
1007 pprModGuts (ModGuts { mg_types = type_env,
1009 = vcat [ ppr_types [] type_env,
1013 ppr_types :: [Var] -> TypeEnv -> SDoc
1014 ppr_types dfun_ids type_env
1015 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1017 ids = [id | id <- typeEnvIds type_env, want_sig id]
1018 want_sig id | opt_PprStyle_Debug = True
1019 | otherwise = isLocalId id &&
1020 isExternalName (idName id) &&
1021 not (id `elem` dfun_ids)
1022 -- isLocalId ignores data constructors, records selectors etc.
1023 -- The isExternalName ignores local dictionary and method bindings
1024 -- that the type checker has invented. Top-level user-defined things
1025 -- have External names.
1027 ppr_insts :: [Var] -> SDoc
1028 ppr_insts [] = empty
1029 ppr_insts dfun_ids = text "INSTANCES" $$ nest 4 (ppr_sigs dfun_ids)
1031 ppr_sigs :: [Var] -> SDoc
1033 -- Print type signatures; sort by OccName
1034 = vcat (map ppr_sig (sortLt lt_sig ids))
1036 lt_sig id1 id2 = getOccName id1 < getOccName id2
1037 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1039 ppr_rules :: [IdCoreRule] -> SDoc
1040 ppr_rules [] = empty
1041 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1042 nest 4 (pprIdRules rs),
1045 ppr_gen_tycons [] = empty
1046 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1047 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]