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 )
25 import RdrHsSyn ( findSplice, main_RDR_Unqual )
27 import PrelNames ( runIOName, rootMainName, mAIN_Name )
28 import RdrName ( RdrName, mkRdrUnqual, emptyGlobalRdrEnv,
30 import TcHsSyn ( zonkTopDecls )
31 import TcExpr ( tcInferRho )
33 import TcType ( tidyTopType )
34 import Inst ( showLIE )
35 import TcBinds ( tcTopBinds )
36 import TcDefaults ( tcDefaults )
37 import TcEnv ( tcExtendGlobalValEnv, tcLookupGlobal )
38 import TcRules ( tcRules )
39 import TcForeign ( tcForeignImports, tcForeignExports )
40 import TcInstDcls ( tcInstDecls1, tcInstDecls2 )
41 import TcIface ( tcExtCoreBindings )
42 import TcSimplify ( tcSimplifyTop )
43 import TcTyClsDecls ( tcTyAndClassDecls )
44 import LoadIface ( loadOrphanModules )
45 import RnNames ( importsFromLocalDecls, rnImports, exportsFromAvail,
47 import RnEnv ( lookupSrcOcc_maybe )
48 import RnSource ( rnSrcDecls, rnTyClDecls, checkModDeprec )
49 import PprCore ( pprIdRules, pprCoreBindings )
50 import CoreSyn ( IdCoreRule, bindersOfBinds )
51 import ErrUtils ( mkDumpDoc, showPass )
52 import Id ( mkLocalId, isLocalId, idName, idType, setIdLocalExported )
54 import Module ( mkHomeModule, mkModuleName, moduleName, moduleEnvElts )
55 import OccName ( mkVarOcc )
56 import Name ( Name, isExternalName, getSrcLoc, getOccName )
58 import TyCon ( tyConHasGenerics )
59 import SrcLoc ( srcLocSpan, Located(..), noLoc, unLoc )
61 import HscTypes ( ModGuts(..), HscEnv(..),
62 GhciMode(..), noDependencies,
63 Deprecs( NoDeprecs ), plusDeprecs,
64 GenAvailInfo(Avail), availsToNameSet, availName,
65 ForeignStubs(NoStubs), TypeEnv, typeEnvTyCons,
66 extendTypeEnvWithIds, typeEnvIds, typeEnvTyCons,
70 import HsSyn ( HsStmtContext(..),
72 collectStmtsBinders, mkSimpleMatch, placeHolderType )
73 import RdrName ( GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..),
74 Provenance(..), ImportSpec(..),
75 lookupLocalRdrEnv, extendLocalRdrEnv )
76 import RnSource ( addTcgDUs )
77 import TcHsSyn ( mkHsLet, zonkTopLExpr, zonkTopBndrs )
78 import TcExpr ( tcCheckRho )
79 import TcMType ( zonkTcType )
80 import TcMatches ( tcStmtsAndThen, TcStmtCtxt(..) )
81 import TcSimplify ( tcSimplifyInteractive, tcSimplifyInfer )
82 import TcType ( Type, mkForAllTys, mkFunTys, mkTyConApp, tyVarsOfType )
83 import TcEnv ( tcLookupTyCon, tcLookupId )
84 import TyCon ( DataConDetails(..) )
85 import Inst ( tcStdSyntaxName )
86 import RnExpr ( rnStmts, rnLExpr )
87 import RnNames ( exportsToAvails )
88 import LoadIface ( loadSrcInterface )
89 import IfaceSyn ( IfaceDecl(..), IfaceClassOp(..), IfaceConDecl(..), IfaceExtName(..),
91 import RnEnv ( lookupOccRn, dataTcOccs, lookupFixityRn )
92 import Id ( Id, isImplicitId )
93 import MkId ( unsafeCoerceId )
94 import TysWiredIn ( mkListTy, unitTy )
95 import IdInfo ( GlobalIdDetails(..) )
96 import SrcLoc ( interactiveSrcLoc )
97 import Var ( setGlobalIdDetails )
98 import Name ( nameOccName, nameModuleName )
99 import NameEnv ( delListFromNameEnv )
100 import PrelNames ( iNTERACTIVE, ioTyConName, printName, monadNames, itName, returnIOName )
101 import Module ( ModuleName, lookupModuleEnvByName )
102 import HscTypes ( InteractiveContext(..),
103 HomeModInfo(..), typeEnvElts,
104 TyThing(..), availNames, icPrintUnqual,
105 ModIface(..), ModDetails(..) )
106 import BasicTypes ( RecFlag(..), Fixity )
107 import Panic ( ghcError, GhcException(..) )
110 import FastString ( mkFastString )
111 import Util ( sortLt )
112 import Bag ( unionBags, snocBag, unitBag )
114 import Maybe ( isJust )
119 %************************************************************************
121 Typecheck and rename a module
123 %************************************************************************
128 -> Located (HsModule RdrName)
129 -> IO (Maybe TcGblEnv)
131 tcRnModule hsc_env (L loc (HsModule maybe_mod exports
132 import_decls local_decls mod_deprec))
133 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
135 let { this_mod = case maybe_mod of
136 Nothing -> mkHomeModule mAIN_Name
137 -- 'module M where' is omitted
138 Just (L _ mod) -> mod } ;
141 initTc hsc_env this_mod $
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 (isJust 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], LHsExpr Id))
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 :: LStmt Name -> TcM ([Id], LHsExpr Id)
294 tcUserStmt (L _ (ExprStmt expr _))
295 = newUnique `thenM` \ uniq ->
297 fresh_it = itName uniq
298 the_bind = noLoc $ FunBind (noLoc fresh_it) False
299 [ mkSimpleMatch [] expr placeHolderType ]
301 tryTcLIE_ (do { -- Try this if the other fails
302 traceTc (text "tcs 1b") ;
304 nlLetStmt [HsBindGroup (unitBag the_bind) [] NonRecursive],
305 nlExprStmt (nlHsApp (nlHsVar printName)
308 (do { -- Try this first
309 traceTc (text "tcs 1a") ;
310 tc_stmts [nlBindStmt (nlVarPat fresh_it) expr] })
312 tcUserStmt stmt = tc_stmts [stmt]
314 ---------------------------
316 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
318 ret_ty = mkListTy unitTy ;
319 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
321 names = map unLoc (collectStmtsBinders stmts) ;
323 stmt_ctxt = SC { sc_what = DoExpr,
325 sc_body = check_body,
328 check_rhs rhs rhs_ty = tcCheckRho rhs (mkTyConApp ioTyCon [rhs_ty]) ;
329 check_body body = tcCheckRho body io_ret_ty ;
331 -- mk_return builds the expression
332 -- returnIO @ [()] [coerce () x, .., coerce () z]
334 -- Despite the inconvenience of building the type applications etc,
335 -- this *has* to be done in type-annotated post-typecheck form
336 -- because we are going to return a list of *polymorphic* values
337 -- coerced to type (). If we built a *source* stmt
338 -- return [coerce x, ..., coerce z]
339 -- then the type checker would instantiate x..z, and we wouldn't
340 -- get their *polymorphic* values. (And we'd get ambiguity errs
341 -- if they were overloaded, since they aren't applied to anything.)
342 mk_return ret_id ids = nlHsApp (noLoc $ TyApp (nlHsVar ret_id) [ret_ty])
343 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
344 mk_item id = nlHsApp (noLoc $ TyApp (nlHsVar unsafeCoerceId) [idType id, unitTy])
347 io_ty = mkTyConApp ioTyCon []
350 -- OK, we're ready to typecheck the stmts
351 traceTc (text "tcs 2") ;
352 ((ids, tc_expr), lie) <- getLIE $ do {
353 (ids, tc_stmts) <- tcStmtsAndThen combine stmt_ctxt stmts $
355 -- Look up the names right in the middle,
356 -- where they will all be in scope
357 ids <- mappM tcLookupId names ;
358 ret_id <- tcLookupId returnIOName ; -- return @ IO
359 return (ids, [nlResultStmt (mk_return ret_id ids)]) } ;
361 io_ids <- mappM (tcStdSyntaxName DoOrigin io_ty) monadNames ;
362 return (ids, noLoc (HsDo DoExpr tc_stmts io_ids io_ret_ty))
365 -- Simplify the context right here, so that we fail
366 -- if there aren't enough instances. Notably, when we see
368 -- we use recoverTc_ to try it <- e
369 -- and then let it = e
370 -- It's the simplify step that rejects the first.
371 traceTc (text "tcs 3") ;
372 const_binds <- tcSimplifyInteractive lie ;
374 -- Build result expression and zonk it
375 let { expr = mkHsLet const_binds tc_expr } ;
376 zonked_expr <- zonkTopLExpr expr ;
377 zonked_ids <- zonkTopBndrs ids ;
379 return (zonked_ids, zonked_expr)
382 combine stmt (ids, stmts) = (ids, stmt:stmts)
386 tcRnExpr just finds the type of an expression
390 -> InteractiveContext
393 tcRnExpr hsc_env ictxt rdr_expr
394 = initTc hsc_env iNTERACTIVE $
395 setInteractiveContext ictxt $ do {
397 (rn_expr, fvs) <- rnLExpr rdr_expr ;
400 -- Now typecheck the expression;
401 -- it might have a rank-2 type (e.g. :t runST)
402 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
403 ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
404 tcSimplifyInteractive lie_top ;
406 let { all_expr_ty = mkForAllTys qtvs $
407 mkFunTys (map idType dict_ids) $
409 zonkTcType all_expr_ty
412 smpl_doc = ptext SLIT("main expression")
418 -> InteractiveContext
420 -> IO (Maybe [(IfaceDecl, Fixity)])
421 -- Look up a RdrName and return all the TyThings it might be
422 -- A capitalised RdrName is given to us in the DataName namespace,
423 -- but we want to treat it as *both* a data constructor
424 -- *and* as a type or class constructor;
425 -- hence the call to dataTcOccs, and we return up to two results
426 tcRnThing hsc_env ictxt rdr_name
427 = initTc hsc_env iNTERACTIVE $
428 setInteractiveContext ictxt $ do {
430 -- If the identifier is a constructor (begins with an
431 -- upper-case letter), then we need to consider both
432 -- constructor and type class identifiers.
433 let { rdr_names = dataTcOccs rdr_name } ;
435 -- results :: [(Messages, Maybe Name)]
436 results <- mapM (tryTc . lookupOccRn) rdr_names ;
438 -- The successful lookups will be (Just name)
439 let { (warns_s, good_names) = unzip [ (msgs, name)
440 | (msgs, Just name) <- results] ;
441 errs_s = [msgs | (msgs, Nothing) <- results] } ;
443 -- Fail if nothing good happened, else add warnings
444 if null good_names then
445 -- No lookup succeeded, so
446 -- pick the first error message and report it
447 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
448 -- while the other is "X is not in scope",
449 -- we definitely want the former; but we might pick the latter
450 do { addMessages (head errs_s) ; failM }
451 else -- Add deprecation warnings
452 mapM_ addMessages warns_s ;
454 -- And lookup up the entities
455 mapM do_one good_names
458 do_one name = do { thing <- tcLookupGlobal name
459 ; fixity <- lookupFixityRn name
460 ; return (toIfaceDecl ictxt thing, fixity) }
462 toIfaceDecl :: InteractiveContext -> TyThing -> IfaceDecl
463 toIfaceDecl ictxt thing
464 = tyThingToIfaceDecl True {- Discard IdInfo -} ext_nm thing
466 unqual = icPrintUnqual ictxt
467 ext_nm n | unqual n = LocalTop (nameOccName n) -- What a hack
468 | otherwise = ExtPkg (nameModuleName n) (nameOccName n)
473 setInteractiveContext :: InteractiveContext -> TcRn a -> TcRn a
474 setInteractiveContext icxt thing_inside
475 = traceTc (text "setIC" <+> ppr (ic_type_env icxt)) `thenM_`
476 (updGblEnv (\env -> env {tcg_rdr_env = ic_rn_gbl_env icxt,
477 tcg_type_env = ic_type_env icxt}) $
478 updLclEnv (\env -> env {tcl_rdr = ic_rn_local_env icxt}) $
483 %************************************************************************
485 Type-checking external-core modules
487 %************************************************************************
490 tcRnExtCore :: HscEnv
492 -> IO (Maybe ModGuts)
493 -- Nothing => some error occurred
495 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
496 -- The decls are IfaceDecls; all names are original names
497 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
499 initTc hsc_env this_mod $ do {
501 let { ldecls = map noLoc decls } ;
503 -- Deal with the type declarations; first bring their stuff
504 -- into scope, then rname them, then type check them
505 (rdr_env, imports) <- importsFromLocalDecls (mkFakeGroup ldecls) ;
507 updGblEnv (\gbl -> gbl { tcg_rdr_env = rdr_env `plusGlobalRdrEnv` tcg_rdr_env gbl,
508 tcg_imports = imports `plusImportAvails` tcg_imports gbl })
511 rn_decls <- rnTyClDecls ldecls ;
514 -- Dump trace of renaming part
515 rnDump (ppr rn_decls) ;
517 -- Typecheck them all together so that
518 -- any mutually recursive types are done right
519 tcg_env <- checkNoErrs (tcTyAndClassDecls rn_decls) ;
520 -- Make the new type env available to stuff slurped from interface files
522 setGblEnv tcg_env $ do {
524 -- Now the core bindings
525 core_binds <- initIfaceExtCore (tcExtCoreBindings this_mod src_binds) ;
529 bndrs = bindersOfBinds core_binds ;
530 my_exports = map (Avail . idName) bndrs ;
531 -- ToDo: export the data types also?
533 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
535 mod_guts = ModGuts { mg_module = this_mod,
536 mg_usages = [], -- ToDo: compute usage
537 mg_dir_imps = [], -- ??
538 mg_deps = noDependencies, -- ??
539 mg_exports = my_exports,
540 mg_types = final_type_env,
541 mg_insts = tcg_insts tcg_env,
543 mg_binds = core_binds,
546 mg_rdr_env = emptyGlobalRdrEnv,
547 mg_fix_env = emptyFixityEnv,
548 mg_deprecs = NoDeprecs,
552 tcCoreDump mod_guts ;
557 mkFakeGroup decls -- Rather clumsy; lots of unused fields
558 = HsGroup { hs_tyclds = decls, -- This is the one we want
559 hs_valds = [], hs_fords = [],
560 hs_instds = [], hs_fixds = [], hs_depds = [],
561 hs_ruleds = [], hs_defds = [] }
565 %************************************************************************
567 Type-checking the top level of a module
569 %************************************************************************
572 tcRnSrcDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
573 -- Returns the variables free in the decls
574 -- Reason: solely to report unused imports and bindings
576 = do { -- Do all the declarations
577 (tc_envs, lie) <- getLIE (tc_rn_src_decls decls) ;
579 -- tcSimplifyTop deals with constant or ambiguous InstIds.
580 -- How could there be ambiguous ones? They can only arise if a
581 -- top-level decl falls under the monomorphism
582 -- restriction, and no subsequent decl instantiates its
583 -- type. (Usually, ambiguous type variables are resolved
584 -- during the generalisation step.)
585 traceTc (text "Tc8") ;
586 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
587 -- Setting the global env exposes the instances to tcSimplifyTop
588 -- Setting the local env exposes the local Ids to tcSimplifyTop,
589 -- so that we get better error messages (monomorphism restriction)
591 -- Backsubstitution. This must be done last.
592 -- Even tcSimplifyTop may do some unification.
593 traceTc (text "Tc9") ;
594 let { (tcg_env, _) = tc_envs ;
595 TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
596 tcg_rules = rules, tcg_fords = fords } = tcg_env } ;
598 (bind_ids, binds', fords', rules') <- zonkTopDecls (binds `unionBags` inst_binds)
601 let { final_type_env = extendTypeEnvWithIds type_env bind_ids } ;
603 -- Make the new type env available to stuff slurped from interface files
604 writeMutVar (tcg_type_env_var tcg_env) final_type_env ;
606 return (tcg_env { tcg_type_env = final_type_env,
607 tcg_binds = binds', tcg_rules = rules', tcg_fords = fords' })
610 tc_rn_src_decls :: [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
611 -- Loops around dealing with each top level inter-splice group
612 -- in turn, until it's dealt with the entire module
614 = do { let { (first_group, group_tail) = findSplice ds } ;
615 -- If ds is [] we get ([], Nothing)
617 -- Type check the decls up to, but not including, the first splice
618 tc_envs@(tcg_env,tcl_env) <- tcRnGroup first_group ;
620 -- Bale out if errors; for example, error recovery when checking
621 -- the RHS of 'main' can mean that 'main' is not in the envt for
622 -- the subsequent checkMain test
627 -- If there is no splice, we're nearly done
629 Nothing -> do { -- Last thing: check for `main'
630 tcg_env <- checkMain ;
631 return (tcg_env, tcl_env)
634 -- If there's a splice, we must carry on
635 Just (SpliceDecl splice_expr, rest_ds) -> do {
637 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
640 -- Rename the splice expression, and get its supporting decls
641 (rn_splice_expr, splice_fvs) <- rnLExpr splice_expr ;
642 failIfErrsM ; -- Don't typecheck if renaming failed
644 -- Execute the splice
645 spliced_decls <- tcSpliceDecls rn_splice_expr ;
647 -- Glue them on the front of the remaining decls and loop
648 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
649 tc_rn_src_decls (spliced_decls ++ rest_ds)
655 %************************************************************************
657 Type-checking the top level of a module
659 %************************************************************************
661 tcRnGroup takes a bunch of top-level source-code declarations, and
663 * gets supporting declarations from interface files
666 * and augments the TcGblEnv with the results
668 In Template Haskell it may be called repeatedly for each group of
669 declarations. It expects there to be an incoming TcGblEnv in the
670 monad; it augments it and returns the new TcGblEnv.
673 tcRnGroup :: HsGroup RdrName -> TcM (TcGblEnv, TcLclEnv)
674 -- Returns the variables free in the decls, for unused-binding reporting
676 = do { -- Rename the declarations
677 (tcg_env, rn_decls) <- rnTopSrcDecls decls ;
678 setGblEnv tcg_env $ do {
680 -- Typecheck the declarations
681 tcTopSrcDecls rn_decls
684 ------------------------------------------------
685 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
687 = do { -- Bring top level binders into scope
688 (rdr_env, imports) <- importsFromLocalDecls group ;
689 updGblEnv (\gbl -> gbl { tcg_rdr_env = rdr_env `plusGlobalRdrEnv` tcg_rdr_env gbl,
690 tcg_imports = imports `plusImportAvails` tcg_imports gbl })
693 traceRn (ptext SLIT("rnTopSrcDecls") <+> ppr rdr_env) ;
694 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
696 -- Rename the source decls
697 (tcg_env, rn_decls) <- rnSrcDecls group ;
700 -- Dump trace of renaming part
701 rnDump (ppr rn_decls) ;
703 return (tcg_env, rn_decls)
706 ------------------------------------------------
707 tcTopSrcDecls :: HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
709 (HsGroup { hs_tyclds = tycl_decls,
710 hs_instds = inst_decls,
711 hs_fords = foreign_decls,
712 hs_defds = default_decls,
713 hs_ruleds = rule_decls,
714 hs_valds = val_binds })
715 = do { -- Type-check the type and class decls, and all imported decls
716 -- The latter come in via tycl_decls
717 traceTc (text "Tc2") ;
719 tcg_env <- checkNoErrs (tcTyAndClassDecls tycl_decls) ;
720 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
721 -- an error we'd better stop now, to avoid a cascade
723 -- Make these type and class decls available to stuff slurped from interface files
724 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
727 setGblEnv tcg_env $ do {
728 -- Source-language instances, including derivings,
729 -- and import the supporting declarations
730 traceTc (text "Tc3") ;
731 (tcg_env, inst_infos, deriv_binds) <- tcInstDecls1 tycl_decls inst_decls ;
732 setGblEnv tcg_env $ do {
734 -- Foreign import declarations next. No zonking necessary
735 -- here; we can tuck them straight into the global environment.
736 traceTc (text "Tc4") ;
737 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
738 tcExtendGlobalValEnv fi_ids $ do {
740 -- Default declarations
741 traceTc (text "Tc4a") ;
742 default_tys <- tcDefaults default_decls ;
743 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
745 -- Value declarations next
746 -- We also typecheck any extra binds that came out
747 -- of the "deriving" process (deriv_binds)
748 traceTc (text "Tc5") ;
749 (tc_val_binds, lcl_env) <- tcTopBinds (val_binds ++ deriv_binds) ;
750 setLclTypeEnv lcl_env $ do {
752 -- Second pass over class and instance declarations,
753 traceTc (text "Tc6") ;
754 (tcl_env, inst_binds) <- tcInstDecls2 tycl_decls inst_infos ;
755 showLIE (text "after instDecls2") ;
758 -- They need to be zonked, so we return them
759 traceTc (text "Tc7") ;
760 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
763 rules <- tcRules rule_decls ;
766 traceTc (text "Tc7a") ;
767 tcg_env <- getGblEnv ;
768 let { all_binds = tc_val_binds `unionBags`
769 inst_binds `unionBags`
772 -- Extend the GblEnv with the (as yet un-zonked)
773 -- bindings, rules, foreign decls
774 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
775 tcg_rules = tcg_rules tcg_env ++ rules,
776 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
777 return (tcg_env', lcl_env)
782 %*********************************************************
784 mkGlobalContext: make up an interactive context
786 Used for initialising the lexical environment
787 of the interactive read-eval-print loop
789 %*********************************************************
793 mkExportEnv :: HscEnv -> [ModuleName] -- Expose these modules' exports only
796 mkExportEnv hsc_env exports
797 = do { mb_envs <- initTc hsc_env iNTERACTIVE $
798 mappM getModuleExports exports
800 Just envs -> return (foldr plusGlobalRdrEnv emptyGlobalRdrEnv envs)
801 Nothing -> return emptyGlobalRdrEnv
802 -- Some error; initTc will have printed it
805 getModuleExports :: ModuleName -> TcM GlobalRdrEnv
807 = do { iface <- load_iface mod
808 ; avails <- exportsToAvails (mi_exports iface)
809 ; let { gres = [ GRE { gre_name = name, gre_prov = vanillaProv mod,
810 gre_deprec = mi_dep_fn iface name }
811 | avail <- avails, name <- availNames avail ] }
812 ; returnM (mkGlobalRdrEnv gres) }
814 vanillaProv :: ModuleName -> Provenance
815 -- We're building a GlobalRdrEnv as if the user imported
816 -- all the specified modules into the global interactive module
817 vanillaProv mod = Imported [ImportSpec mod mod False
818 (srcLocSpan interactiveSrcLoc)] False
824 -> InteractiveContext
825 -> ModuleName -- Module to inspect
826 -> Bool -- Grab just the exports, or the whole toplev
827 -> IO (Maybe [IfaceDecl])
829 getModuleContents hsc_env ictxt mod exports_only
830 = initTc hsc_env iNTERACTIVE (get_mod_contents exports_only)
832 get_mod_contents exports_only
833 | not exports_only -- We want the whole top-level type env
834 -- so it had better be a home module
836 ; case lookupModuleEnvByName hpt mod of
837 Just mod_info -> return (map (toIfaceDecl ictxt) $
840 md_types (hm_details mod_info))
841 Nothing -> ghcError (ProgramError (showSDoc (noRdrEnvErr mod)))
842 -- This is a system error; the module should be in the HPT
845 | otherwise -- Want the exports only
846 = do { iface <- load_iface mod
847 ; avails <- exportsToAvails (mi_exports iface)
848 ; mappM get_decl avails
852 = do { thing <- tcLookupGlobal (availName avail)
853 ; return (filter_decl (availOccs avail) (toIfaceDecl ictxt thing)) }
855 ---------------------
856 filter_decl occs decl@(IfaceClass {ifSigs = sigs})
857 = decl { ifSigs = filter (keep_sig occs) sigs }
858 filter_decl occs decl@(IfaceData {ifCons = DataCons cons})
859 = decl { ifCons = DataCons (filter (keep_con occs) cons) }
860 filter_decl occs decl
863 keep_sig occs (IfaceClassOp occ _ _) = occ `elem` occs
864 keep_con occs (IfaceConDecl occ _ _ _ _ _) = occ `elem` occs
866 availOccs avail = map nameOccName (availNames avail)
868 wantToSee (AnId id) = not (isImplicitId id)
869 wantToSee (ADataCon _) = False -- They'll come via their TyCon
872 ---------------------
873 load_iface mod = loadSrcInterface doc mod False {- Not boot iface -}
875 doc = ptext SLIT("context for compiling statements")
877 ---------------------
878 noRdrEnvErr mod = ptext SLIT("No top-level environment available for module")
883 %************************************************************************
887 %************************************************************************
891 = do { ghci_mode <- getGhciMode ;
892 tcg_env <- getGblEnv ;
894 mb_main_mod <- readMutVar v_MainModIs ;
895 mb_main_fn <- readMutVar v_MainFunIs ;
896 let { main_mod = case mb_main_mod of {
897 Just mod -> mkModuleName mod ;
898 Nothing -> mAIN_Name } ;
899 main_fn = case mb_main_fn of {
900 Just fn -> mkRdrUnqual (mkVarOcc (mkFastString fn)) ;
901 Nothing -> main_RDR_Unqual } } ;
903 check_main ghci_mode tcg_env main_mod main_fn
907 check_main ghci_mode tcg_env main_mod main_fn
908 -- If we are in module Main, check that 'main' is defined.
909 -- It may be imported from another module!
911 -- ToDo: We have to return the main_name separately, because it's a
912 -- bona fide 'use', and should be recorded as such, but the others
915 -- Blimey: a whole page of code to do this...
916 | mod_name /= main_mod
920 = addErrCtxt mainCtxt $
921 do { mb_main <- lookupSrcOcc_maybe main_fn
922 -- Check that 'main' is in scope
923 -- It might be imported from another module!
925 Nothing -> do { complain_no_main
928 { let { rhs = nlHsApp (nlHsVar runIOName) (nlHsVar main_name) }
929 -- :Main.main :: IO () = runIO main
931 ; (main_expr, ty) <- addSrcSpan (srcLocSpan (getSrcLoc main_name)) $
934 ; let { root_main_id = setIdLocalExported (mkLocalId rootMainName ty) ;
935 main_bind = noLoc (VarBind root_main_id main_expr) }
937 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
939 tcg_dus = tcg_dus tcg_env
940 `plusDU` usesOnly (unitFV main_name)
944 mod_name = moduleName (tcg_mod tcg_env)
946 complain_no_main | ghci_mode == Interactive = return ()
947 | otherwise = failWithTc noMainMsg
948 -- In interactive mode, don't worry about the absence of 'main'
949 -- In other modes, fail altogether, so that we don't go on
950 -- and complain a second time when processing the export list.
952 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
953 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
954 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
958 %************************************************************************
962 %************************************************************************
965 rnDump :: SDoc -> TcRn ()
966 -- Dump, with a banner, if -ddump-rn
967 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
969 tcDump :: TcGblEnv -> TcRn ()
971 = do { dflags <- getDOpts ;
973 -- Dump short output if -ddump-types or -ddump-tc
974 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
975 (dumpTcRn short_dump) ;
977 -- Dump bindings if -ddump-tc
978 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
981 short_dump = pprTcGblEnv env
982 full_dump = ppr (tcg_binds env)
983 -- NB: foreign x-d's have undefined's in their types;
984 -- hence can't show the tc_fords
987 = do { dflags <- getDOpts ;
988 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
989 (dumpTcRn (pprModGuts mod_guts)) ;
991 -- Dump bindings if -ddump-tc
992 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
994 full_dump = pprCoreBindings (mg_binds mod_guts)
996 -- It's unpleasant having both pprModGuts and pprModDetails here
997 pprTcGblEnv :: TcGblEnv -> SDoc
998 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
999 tcg_insts = dfun_ids,
1001 tcg_imports = imports })
1002 = vcat [ ppr_types dfun_ids type_env
1003 , ppr_insts dfun_ids
1004 , vcat (map ppr rules)
1005 , ppr_gen_tycons (typeEnvTyCons type_env)
1006 , ptext SLIT("Dependent modules:") <+> ppr (moduleEnvElts (imp_dep_mods imports))
1007 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1009 pprModGuts :: ModGuts -> SDoc
1010 pprModGuts (ModGuts { mg_types = type_env,
1012 = vcat [ ppr_types [] type_env,
1016 ppr_types :: [Var] -> TypeEnv -> SDoc
1017 ppr_types dfun_ids type_env
1018 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1020 ids = [id | id <- typeEnvIds type_env, want_sig id]
1021 want_sig id | opt_PprStyle_Debug = True
1022 | otherwise = isLocalId id &&
1023 isExternalName (idName id) &&
1024 not (id `elem` dfun_ids)
1025 -- isLocalId ignores data constructors, records selectors etc.
1026 -- The isExternalName ignores local dictionary and method bindings
1027 -- that the type checker has invented. Top-level user-defined things
1028 -- have External names.
1030 ppr_insts :: [Var] -> SDoc
1031 ppr_insts [] = empty
1032 ppr_insts dfun_ids = text "INSTANCES" $$ nest 4 (ppr_sigs dfun_ids)
1034 ppr_sigs :: [Var] -> SDoc
1036 -- Print type signatures; sort by OccName
1037 = vcat (map ppr_sig (sortLt lt_sig ids))
1039 lt_sig id1 id2 = getOccName id1 < getOccName id2
1040 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1042 ppr_rules :: [IdCoreRule] -> SDoc
1043 ppr_rules [] = empty
1044 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1045 nest 4 (pprIdRules rs),
1048 ppr_gen_tycons [] = empty
1049 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1050 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]