2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[TcModule]{Typechecking a whole module}
9 mkGlobalContext, getModuleContents,
11 tcRnModule, checkOldIface,
12 importSupportingDecls, tcTopSrcDecls,
13 tcRnIface, tcRnExtCore, tcRnStmt, tcRnExpr, tcRnThing
16 #include "HsVersions.h"
19 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
20 import DsMeta ( qTyConName )
23 import CmdLineOpts ( DynFlag(..), opt_PprStyle_Debug, dopt )
24 import HsSyn ( HsModule(..), HsBinds(..), MonoBinds(..), HsExpr(..),
25 Stmt(..), Pat(VarPat), HsStmtContext(..), RuleDecl(..),
26 HsGroup(..), SpliceDecl(..),
27 mkSimpleMatch, placeHolderType, toHsType, andMonoBinds,
28 isSrcRule, collectStmtsBinders
30 import RdrHsSyn ( RdrNameHsModule, RdrNameHsDecl, RdrNameStmt, RdrNameHsExpr,
31 emptyGroup, mkGroup, findSplice, addImpDecls )
33 import PrelNames ( iNTERACTIVE, ioTyConName, printName,
34 returnIOName, bindIOName, failIOName, thenIOName, runIOName,
35 dollarMainName, itName, mAIN_Name
37 import MkId ( unsafeCoerceId )
38 import RdrName ( RdrName, getRdrName, mkUnqual, mkRdrUnqual,
39 lookupRdrEnv, elemRdrEnv )
41 import RnHsSyn ( RenamedStmt, RenamedTyClDecl,
42 ruleDeclFVs, instDeclFVs, tyClDeclFVs )
43 import TcHsSyn ( TypecheckedHsExpr, TypecheckedRuleDecl,
44 zonkTopBinds, zonkTopDecls, mkHsLet,
45 zonkTopExpr, zonkTopBndrs
48 import TcExpr ( tcExpr_id )
50 import TcMType ( newTyVarTy, zonkTcType )
51 import TcType ( Type, liftedTypeKind,
52 tyVarsOfType, tcFunResultTy,
53 mkForAllTys, mkFunTys, mkTyConApp, tcSplitForAllTys
55 import TcMatches ( tcStmtsAndThen )
56 import Inst ( showLIE )
57 import TcBinds ( tcTopBinds )
58 import TcClassDcl ( tcClassDecls2 )
59 import TcDefaults ( tcDefaults )
60 import TcEnv ( RecTcGblEnv,
63 tcExtendInstEnv, tcExtendRules,
64 tcLookupTyCon, tcLookupGlobal,
67 import TcRules ( tcRules )
68 import TcForeign ( tcForeignImports, tcForeignExports )
69 import TcIfaceSig ( tcInterfaceSigs, tcCoreBinds )
70 import TcInstDcls ( tcInstDecls1, tcIfaceInstDecls, tcInstDecls2 )
71 import TcSimplify ( tcSimplifyTop, tcSimplifyInfer )
72 import TcTyClsDecls ( tcTyAndClassDecls )
74 import RnNames ( rnImports, exportsFromAvail, reportUnusedNames )
75 import RnIfaces ( slurpImpDecls, checkVersions, RecompileRequired, outOfDate )
76 import RnHiFiles ( readIface, loadOldIface )
77 import RnEnv ( lookupSrcName, lookupOccRn, plusGlobalRdrEnv,
78 ubiquitousNames, implicitModuleFVs, implicitStmtFVs, dataTcOccs )
79 import RnExpr ( rnStmts, rnExpr )
80 import RnNames ( importsFromLocalDecls )
81 import RnSource ( rnSrcDecls, checkModDeprec, rnStats )
83 import OccName ( varName )
84 import CoreUnfold ( unfoldingTemplate )
85 import CoreSyn ( IdCoreRule, Bind(..) )
86 import PprCore ( pprIdRules, pprCoreBindings )
87 import TysWiredIn ( mkListTy, unitTy )
88 import ErrUtils ( mkDumpDoc, showPass )
89 import Id ( Id, mkLocalId, isLocalId, idName, idType, idUnfolding, setIdLocalExported )
90 import IdInfo ( GlobalIdDetails(..) )
91 import Var ( Var, setGlobalIdDetails )
92 import Module ( Module, moduleName, moduleUserString, moduleEnvElts )
93 import Name ( Name, isExternalName, getSrcLoc, nameOccName )
94 import NameEnv ( delListFromNameEnv )
96 import TyCon ( tyConGenInfo )
97 import BasicTypes ( EP(..), RecFlag(..) )
98 import SrcLoc ( noSrcLoc )
100 import HscTypes ( PersistentCompilerState(..), InteractiveContext(..),
101 ModIface, ModDetails(..), ModGuts(..),
103 ModIface(..), ModDetails(..), IfaceDecls(..),
104 GhciMode(..), noDependencies,
105 Deprecations(..), plusDeprecs,
107 GenAvailInfo(Avail), availsToNameSet,
109 TypeEnv, TyThing, typeEnvTyCons,
110 extendTypeEnvWithIds, typeEnvIds, typeEnvTyCons,
111 extendLocalRdrEnv, emptyFixityEnv
114 import RdrName ( rdrEnvElts )
115 import RnHiFiles ( loadInterface )
116 import RnEnv ( mkGlobalRdrEnv )
117 import HscTypes ( GlobalRdrElt(..), GlobalRdrEnv, ImportReason(..), Provenance(..),
121 import Maybe ( catMaybes )
122 import Panic ( showException )
123 import List ( partition )
124 import Util ( sortLt )
129 %************************************************************************
131 Typecheck and rename a module
133 %************************************************************************
137 tcRnModule :: HscEnv -> PersistentCompilerState
139 -> IO (PersistentCompilerState, Maybe TcGblEnv)
141 tcRnModule hsc_env pcs
142 (HsModule this_mod _ exports import_decls local_decls mod_deprec loc)
143 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
145 initTc hsc_env pcs this_mod $ addSrcLoc loc $
146 do { -- Deal with imports; sets tcg_rdr_env, tcg_imports
147 (rdr_env, imports) <- rnImports import_decls ;
148 updGblEnv ( \ gbl -> gbl { tcg_rdr_env = rdr_env,
149 tcg_imports = tcg_imports gbl `plusImportAvails` imports })
151 traceRn (text "rn1" <+> ppr (imp_dep_mods imports)) ;
152 -- Fail if there are any errors so far
153 -- The error printing (if needed) takes advantage
154 -- of the tcg_env we have now set
157 traceRn (text "rn1a") ;
158 -- Rename and type check the declarations
159 (tcg_env, src_fvs) <- tcRnSrcDecls local_decls ;
160 setGblEnv tcg_env $ do {
161 traceRn (text "rn2") ;
164 (tcg_env, main_fvs) <- checkMain ;
165 setGblEnv tcg_env $ do {
167 traceRn (text "rn3") ;
168 -- Check whether the entire module is deprecated
169 -- This happens only once per module
170 -- Returns the full new deprecations; a module deprecation
171 -- over-rides the earlier ones
172 let { mod_deprecs = checkModDeprec mod_deprec } ;
173 updGblEnv (\gbl -> gbl { tcg_deprecs = tcg_deprecs gbl `plusDeprecs` mod_deprecs })
176 -- Process the export list
177 export_avails <- exportsFromAvail exports ;
178 updGblEnv (\gbl -> gbl { tcg_exports = export_avails })
181 -- Get the supporting decls for the exports
182 -- This is important *only* to gether usage information
183 -- (see comments with MkIface.mkImportInfo for why)
184 -- For OneShot compilation we could just throw away the decls
185 -- but for Batch or Interactive we must put them in the type
186 -- envt because they've been removed from the holding pen
187 let { export_fvs = availsToNameSet export_avails } ;
188 tcg_env <- importSupportingDecls export_fvs ;
189 setGblEnv tcg_env $ do {
191 -- Report unused names
192 let { used_fvs = src_fvs `plusFV` main_fvs `plusFV` export_fvs } ;
193 reportUnusedNames tcg_env used_fvs ;
195 -- Dump output and return
202 %*********************************************************
204 \subsection{Closing up the interface decls}
206 %*********************************************************
208 Suppose we discover we don't need to recompile. Then we start from the
209 IfaceDecls in the ModIface, and fluff them up by sucking in all the decls they need.
213 -> PersistentCompilerState
214 -> ModIface -- Get the decls from here
215 -> IO (PersistentCompilerState, Maybe ModDetails)
216 -- Nothing <=> errors happened
217 tcRnIface hsc_env pcs
218 (ModIface {mi_module = mod, mi_decls = iface_decls})
219 = initTc hsc_env pcs mod $ do {
221 -- Get the supporting decls, and typecheck them all together
222 -- so that any mutually recursive types are done right
223 extra_decls <- slurpImpDecls needed ;
224 env <- typecheckIfaceDecls (group `addImpDecls` extra_decls) ;
226 returnM (ModDetails { md_types = tcg_type_env env,
227 md_insts = tcg_insts env,
228 md_rules = hsCoreRules (tcg_rules env)
229 -- All the rules from an interface are of the IfaceRuleOut form
232 rule_decls = dcl_rules iface_decls
233 inst_decls = dcl_insts iface_decls
234 tycl_decls = dcl_tycl iface_decls
235 group = emptyGroup { hs_ruleds = rule_decls,
236 hs_instds = inst_decls,
237 hs_tyclds = tycl_decls }
238 needed = unionManyNameSets (map ruleDeclFVs rule_decls) `unionNameSets`
239 unionManyNameSets (map instDeclFVs inst_decls) `unionNameSets`
240 unionManyNameSets (map tyClDeclFVs tycl_decls) `unionNameSets`
242 -- Data type decls with record selectors,
243 -- which may appear in the decls, need unpackCString
244 -- and friends. It's easier to just grab them right now.
246 hsCoreRules :: [TypecheckedRuleDecl] -> [IdCoreRule]
247 -- All post-typechecking Iface rules have the form IfaceRuleOut
248 hsCoreRules rules = [(id,rule) | IfaceRuleOut id rule <- rules]
252 %************************************************************************
254 The interactive interface
256 %************************************************************************
259 tcRnStmt :: HscEnv -> PersistentCompilerState
260 -> InteractiveContext
262 -> IO (PersistentCompilerState,
263 Maybe (InteractiveContext, [Name], TypecheckedHsExpr))
264 -- The returned [Id] is the same as the input except for
265 -- ExprStmt, in which case the returned [Name] is [itName]
267 tcRnStmt hsc_env pcs ictxt rdr_stmt
268 = initTc hsc_env pcs iNTERACTIVE $
269 setInteractiveContext ictxt $ do {
271 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
272 ([rn_stmt], fvs) <- initRnInteractive ictxt
273 (rnStmts DoExpr [rdr_stmt]) ;
274 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
277 -- Suck in the supporting declarations and typecheck them
278 tcg_env <- importSupportingDecls (fvs `plusFV` implicitStmtFVs fvs) ;
279 -- NB: an earlier version deleted (rdrEnvElts local_env) from
280 -- the fvs. But (a) that isn't necessary, because previously
281 -- bound things in the local_env will be in the TypeEnv, and
282 -- the renamer doesn't re-slurp such things, and
283 -- (b) it's WRONG to delete them. Consider in GHCi:
284 -- Mod> let x = e :: T
285 -- Mod> let y = x + 3
286 -- We need to pass 'x' among the fvs to slurpImpDecls, so that
287 -- the latter can see that T is a gate, and hence import the Num T
288 -- instance decl. (See the InTypEnv case in RnIfaces.slurpSourceRefs.)
289 setGblEnv tcg_env $ do {
291 -- The real work is done here
292 ((bound_ids, tc_expr), lie) <- getLIE (tcUserStmt rn_stmt) ;
294 traceTc (text "tcs 1") ;
295 let { -- Make all the bound ids "global" ids, now that
296 -- they're notionally top-level bindings. This is
297 -- important: otherwise when we come to compile an expression
298 -- using these ids later, the byte code generator will consider
299 -- the occurrences to be free rather than global.
300 global_ids = map globaliseId bound_ids ;
301 globaliseId id = setGlobalIdDetails id VanillaGlobal ;
303 -- Update the interactive context
304 rn_env = ic_rn_local_env ictxt ;
305 type_env = ic_type_env ictxt ;
307 bound_names = map idName global_ids ;
308 new_rn_env = extendLocalRdrEnv rn_env bound_names ;
310 -- Remove any shadowed bindings from the type_env;
311 -- they are inaccessible but might, I suppose, cause
312 -- a space leak if we leave them there
313 shadowed = [ n | name <- bound_names,
314 let rdr_name = mkRdrUnqual (nameOccName name),
315 Just n <- [lookupRdrEnv rn_env rdr_name] ] ;
317 filtered_type_env = delListFromNameEnv type_env shadowed ;
318 new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ;
320 new_ic = ictxt { ic_rn_local_env = new_rn_env,
321 ic_type_env = new_type_env }
324 dumpOptTcRn Opt_D_dump_tc
325 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
326 text "Typechecked expr" <+> ppr tc_expr]) ;
328 returnM (new_ic, bound_names, tc_expr)
333 Here is the grand plan, implemented in tcUserStmt
335 What you type The IO [HValue] that hscStmt returns
336 ------------- ------------------------------------
337 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
340 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
343 expr (of IO type) ==> expr >>= \ v -> return [coerce HVal v]
344 [NB: result not printed] bindings: [it]
346 expr (of non-IO type, ==> let v = expr in print v >> return [coerce HVal v]
347 result showable) bindings: [it]
349 expr (of non-IO type,
350 result not showable) ==> error
354 ---------------------------
355 tcUserStmt :: RenamedStmt -> TcM ([Id], TypecheckedHsExpr)
356 tcUserStmt (ExprStmt expr _ loc)
357 = newUnique `thenM` \ uniq ->
359 fresh_it = itName uniq
360 the_bind = FunMonoBind fresh_it False
361 [ mkSimpleMatch [] expr placeHolderType loc ] loc
363 tryTcLIE_ (do { -- Try this if the other fails
364 traceTc (text "tcs 1b") ;
366 LetStmt (MonoBind the_bind [] NonRecursive),
367 ExprStmt (HsApp (HsVar printName) (HsVar fresh_it))
368 placeHolderType loc] })
369 (do { -- Try this first
370 traceTc (text "tcs 1a") ;
371 tc_stmts [BindStmt (VarPat fresh_it) expr loc] })
373 tcUserStmt stmt = tc_stmts [stmt]
375 ---------------------------
377 = do { io_ids <- mappM tcLookupId
378 [returnIOName, failIOName, bindIOName, thenIOName] ;
379 ioTyCon <- tcLookupTyCon ioTyConName ;
380 res_ty <- newTyVarTy liftedTypeKind ;
382 names = collectStmtsBinders stmts ;
383 return_id = head io_ids ; -- Rather gruesome
385 io_ty = (\ ty -> mkTyConApp ioTyCon [ty], res_ty) ;
387 -- mk_return builds the expression
388 -- returnIO @ [()] [coerce () x, .., coerce () z]
389 mk_return ids = HsApp (TyApp (HsVar return_id) [mkListTy unitTy])
390 (ExplicitList unitTy (map mk_item ids)) ;
392 mk_item id = HsApp (TyApp (HsVar unsafeCoerceId) [idType id, unitTy])
395 -- OK, we're ready to typecheck the stmts
396 traceTc (text "tcs 2") ;
397 ((ids, tc_stmts), lie) <-
398 getLIE $ tcStmtsAndThen combine DoExpr io_ty stmts $
400 -- Look up the names right in the middle,
401 -- where they will all be in scope
402 ids <- mappM tcLookupId names ;
403 return (ids, [ResultStmt (mk_return ids) noSrcLoc])
406 -- Simplify the context right here, so that we fail
407 -- if there aren't enough instances. Notably, when we see
409 -- we use recoverTc_ to try it <- e
410 -- and then let it = e
411 -- It's the simplify step that rejects the first.
412 traceTc (text "tcs 3") ;
413 const_binds <- tcSimplifyTop lie ;
415 -- Build result expression and zonk it
416 let { expr = mkHsLet const_binds $
417 HsDo DoExpr tc_stmts io_ids
418 (mkTyConApp ioTyCon [mkListTy unitTy]) noSrcLoc } ;
419 zonked_expr <- zonkTopExpr expr ;
420 zonked_ids <- zonkTopBndrs ids ;
422 return (zonked_ids, zonked_expr)
425 combine stmt (ids, stmts) = (ids, stmt:stmts)
429 tcRnExpr just finds the type of an expression
432 tcRnExpr :: HscEnv -> PersistentCompilerState
433 -> InteractiveContext
435 -> IO (PersistentCompilerState, Maybe Type)
436 tcRnExpr hsc_env pcs ictxt rdr_expr
437 = initTc hsc_env pcs iNTERACTIVE $
438 setInteractiveContext ictxt $ do {
440 (rn_expr, fvs) <- initRnInteractive ictxt (rnExpr rdr_expr) ;
443 -- Suck in the supporting declarations and typecheck them
444 tcg_env <- importSupportingDecls (fvs `plusFV` ubiquitousNames) ;
445 setGblEnv tcg_env $ do {
447 -- Now typecheck the expression;
448 -- it might have a rank-2 type (e.g. :t runST)
449 -- Hence the hole type (c.f. TcExpr.tcExpr_id)
450 ((tc_expr, res_ty), lie) <- getLIE (tcExpr_id rn_expr) ;
451 ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
452 tcSimplifyTop lie_top ;
454 let { all_expr_ty = mkForAllTys qtvs $
455 mkFunTys (map idType dict_ids) $
457 zonkTcType all_expr_ty
460 smpl_doc = ptext SLIT("main expression")
465 tcRnThing :: HscEnv -> PersistentCompilerState
466 -> InteractiveContext
468 -> IO (PersistentCompilerState, Maybe [TyThing])
469 -- Look up a RdrName and return all the TyThings it might be
470 -- We treat a capitalised RdrName as both a data constructor
471 -- and as a type or class constructor; hence we return up to two results
472 tcRnThing hsc_env pcs ictxt rdr_name
473 = initTc hsc_env pcs iNTERACTIVE $
474 setInteractiveContext ictxt $ do {
476 -- If the identifier is a constructor (begins with an
477 -- upper-case letter), then we need to consider both
478 -- constructor and type class identifiers.
479 let { rdr_names = dataTcOccs rdr_name } ;
481 (msgs_s, mb_names) <- initRnInteractive ictxt
482 (mapAndUnzipM (tryTc . lookupOccRn) rdr_names) ;
483 let { names = catMaybes mb_names } ;
486 do { addMessages (head msgs_s) ; failM }
489 -- Add deprecation warnings
490 mapM_ addMessages msgs_s ;
492 -- Slurp in the supporting declarations
493 tcg_env <- importSupportingDecls (mkFVs names) ;
494 setGblEnv tcg_env $ do {
496 -- And lookup up the entities
497 mapM tcLookupGlobal names
503 setInteractiveContext :: InteractiveContext -> TcRn m a -> TcRn m a
504 setInteractiveContext icxt thing_inside
505 = traceTc (text "setIC" <+> ppr (ic_type_env icxt)) `thenM_`
506 updGblEnv (\ env -> env { tcg_rdr_env = ic_rn_gbl_env icxt,
507 tcg_type_env = ic_type_env icxt })
510 initRnInteractive :: InteractiveContext -> RnM a -> TcM a
511 -- Set the local RdrEnv from the interactive context
512 initRnInteractive ictxt rn_thing
513 = initRn CmdLineMode $
514 setLocalRdrEnv (ic_rn_local_env ictxt) $
518 %************************************************************************
520 Type-checking external-core modules
522 %************************************************************************
525 tcRnExtCore :: HscEnv -> PersistentCompilerState
527 -> IO (PersistentCompilerState, Maybe ModGuts)
528 -- Nothing => some error occurred
530 tcRnExtCore hsc_env pcs
531 (HsModule this_mod _ _ _ local_decls _ loc)
532 -- Rename the (Core) module. It's a bit like an interface
533 -- file: all names are original names
534 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
536 initTc hsc_env pcs this_mod $ addSrcLoc loc $ do {
538 -- Rename the source, only in interface mode.
539 -- rnSrcDecls handles fixity decls etc too, which won't occur
540 -- but that doesn't matter
541 let { local_group = mkGroup local_decls } ;
542 (_, rn_local_decls, fvs) <- initRn (InterfaceMode this_mod)
543 (rnSrcDecls local_group) ;
546 -- Get the supporting decls, and typecheck them all together
547 -- so that any mutually recursive types are done right
548 extra_decls <- slurpImpDecls fvs ;
549 tcg_env <- typecheckIfaceDecls (rn_local_decls `addImpDecls` extra_decls) ;
550 setGblEnv tcg_env $ do {
552 -- Now the core bindings
553 core_prs <- tcCoreBinds (hs_coreds rn_local_decls) ;
554 tcExtendGlobalValEnv (map fst core_prs) $ do {
558 bndrs = map fst core_prs ;
559 my_exports = map (Avail . idName) bndrs ;
560 -- ToDo: export the data types also?
562 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
564 mod_guts = ModGuts { mg_module = this_mod,
565 mg_usages = [], -- ToDo: compute usage
566 mg_dir_imps = [], -- ??
567 mg_deps = noDependencies, -- ??
568 mg_exports = my_exports,
569 mg_types = final_type_env,
570 mg_insts = tcg_insts tcg_env,
571 mg_rules = hsCoreRules (tcg_rules tcg_env),
572 mg_binds = [Rec core_prs],
575 mg_rdr_env = emptyGlobalRdrEnv,
576 mg_fix_env = emptyFixityEnv,
577 mg_deprecs = NoDeprecs,
581 tcCoreDump mod_guts ;
588 %************************************************************************
590 Type-checking the top level of a module
592 %************************************************************************
595 tcRnSrcDecls :: [RdrNameHsDecl] -> TcM (TcGblEnv, FreeVars)
596 -- Returns the variables free in the decls
597 -- Reason: solely to report unused imports and bindings
598 tcRnSrcDecls [] = do { tcg_env <- getGblEnv ; return (tcg_env, emptyFVs) }
600 = do { let { (first_group, group_tail) = findSplice ds } ;
602 -- Type check the decls up to, but not including, the first splice
603 (tcg_env, src_fvs1) <- tcRnGroup first_group ;
605 -- If there is no splice, we're done
607 Nothing -> return (tcg_env, src_fvs1)
608 Just (SpliceDecl splice_expr splice_loc, rest_ds) -> do {
610 setGblEnv tcg_env $ do {
613 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
615 -- Rename the splice expression, and get its supporting decls
616 (rn_splice_expr, fvs) <- initRn SourceMode $
617 addSrcLoc splice_loc $
619 tcg_env <- importSupportingDecls (fvs `addOneFV` qTyConName) ;
620 setGblEnv tcg_env $ do {
622 -- Execute the splice
623 spliced_decls <- tcSpliceDecls rn_splice_expr ;
625 -- Glue them on the front of the remaining decls and loop
626 (tcg_env, src_fvs2) <- tcRnSrcDecls (spliced_decls ++ rest_ds) ;
628 return (tcg_env, src_fvs1 `plusFV` src_fvs2)
635 %************************************************************************
637 Type-checking the top level of a module
639 %************************************************************************
641 tcRnGroup takes a bunch of top-level source-code declarations, and
643 * gets supporting declarations from interface files
646 * and augments the TcGblEnv with the results
648 In Template Haskell it may be called repeatedly for each group of
649 declarations. It expects there to be an incoming TcGblEnv in the
650 monad; it augments it and returns the new TcGblEnv.
653 tcRnGroup :: HsGroup RdrName -> TcM (TcGblEnv, FreeVars)
654 -- Returns the variables free in the decls
656 = do { -- Rename the declarations
657 (tcg_env, rn_decls, src_fvs) <- rnTopSrcDecls decls ;
658 setGblEnv tcg_env $ do {
660 -- Typecheck the declarations
661 tcg_env <- tcTopSrcDecls rn_decls ;
662 return (tcg_env, src_fvs)
665 ------------------------------------------------
666 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name, FreeVars)
668 = do { -- Bring top level binders into scope
669 (rdr_env, imports) <- importsFromLocalDecls group ;
670 updGblEnv (\gbl -> gbl { tcg_rdr_env = rdr_env `plusGlobalRdrEnv`
672 tcg_imports = imports `plusImportAvails`
676 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
678 -- Rename the source decls
679 (tcg_env, rn_src_decls, src_fvs) <- initRn SourceMode (rnSrcDecls group) ;
680 setGblEnv tcg_env $ do {
684 -- Import consquential imports
685 rn_imp_decls <- slurpImpDecls (src_fvs `plusFV` implicitModuleFVs src_fvs) ;
686 let { rn_decls = rn_src_decls `addImpDecls` rn_imp_decls } ;
688 -- Dump trace of renaming part
689 rnDump (ppr rn_decls) ;
690 rnStats rn_imp_decls ;
692 return (tcg_env, rn_decls, src_fvs)
695 ------------------------------------------------
696 tcTopSrcDecls :: HsGroup Name -> TcM TcGblEnv
697 tcTopSrcDecls rn_decls
698 = fixM (\ unf_env -> do {
699 -- Loop back the final environment, including the fully zonked
700 -- versions of bindings from this module. In the presence of mutual
701 -- recursion, interface type signatures may mention variables defined
702 -- in this module, which is why the knot is so big
705 ((tcg_env, binds, rules, fords), lie) <- getLIE (
706 tc_src_decls unf_env rn_decls
709 -- tcSimplifyTop deals with constant or ambiguous InstIds.
710 -- How could there be ambiguous ones? They can only arise if a
711 -- top-level decl falls under the monomorphism
712 -- restriction, and no subsequent decl instantiates its
713 -- type. (Usually, ambiguous type variables are resolved
714 -- during the generalisation step.)
715 traceTc (text "Tc8") ;
716 inst_binds <- setGblEnv tcg_env (tcSimplifyTop lie) ;
717 -- The setGblEnv exposes the instances to tcSimplifyTop
719 -- Backsubstitution. This must be done last.
720 -- Even tcSimplifyTop may do some unification.
721 traceTc (text "Tc9") ;
722 (ids, binds', fords', rules') <- zonkTopDecls (binds `andMonoBinds` inst_binds)
725 let { tcg_env' = tcg_env { tcg_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) ids,
726 tcg_binds = tcg_binds tcg_env `andMonoBinds` binds',
727 tcg_rules = tcg_rules tcg_env ++ rules',
728 tcg_fords = tcg_fords tcg_env ++ fords' } } ;
734 (HsGroup { hs_tyclds = tycl_decls,
735 hs_instds = inst_decls,
736 hs_fords = foreign_decls,
737 hs_defds = default_decls,
738 hs_ruleds = rule_decls,
739 hs_valds = val_binds })
740 = do { -- Type-check the type and class decls, and all imported decls
741 traceTc (text "Tc2") ;
742 tcg_env <- tcTyClDecls unf_env tycl_decls ;
743 setGblEnv tcg_env $ do {
745 -- Source-language instances, including derivings,
746 -- and import the supporting declarations
747 traceTc (text "Tc3") ;
748 (tcg_env, inst_infos, deriv_binds, fvs) <- tcInstDecls1 tycl_decls inst_decls ;
749 setGblEnv tcg_env $ do {
750 tcg_env <- importSupportingDecls fvs ;
751 setGblEnv tcg_env $ do {
753 -- Foreign import declarations next. No zonking necessary
754 -- here; we can tuck them straight into the global environment.
755 traceTc (text "Tc4") ;
756 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
757 tcExtendGlobalValEnv fi_ids $
758 updGblEnv (\gbl -> gbl { tcg_fords = tcg_fords gbl ++ fi_decls })
761 -- Default declarations
762 traceTc (text "Tc4a") ;
763 default_tys <- tcDefaults default_decls ;
764 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
766 -- Value declarations next
767 -- We also typecheck any extra binds that came out
768 -- of the "deriving" process
769 traceTc (text "Tc5") ;
770 (tc_val_binds, lcl_env) <- tcTopBinds (val_binds `ThenBinds` deriv_binds) ;
771 setLclTypeEnv lcl_env $ do {
773 -- Second pass over class and instance declarations,
774 -- plus rules and foreign exports, to generate bindings
775 traceTc (text "Tc6") ;
776 (cls_dm_binds, dm_ids) <- tcClassDecls2 tycl_decls ;
777 tcExtendGlobalValEnv dm_ids $ do {
778 inst_binds <- tcInstDecls2 inst_infos ;
779 showLIE "after instDecls2" ;
782 -- They need to be zonked, so we return them
783 traceTc (text "Tc7") ;
784 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
787 -- Need to partition them because the source rules
788 -- must be zonked before adding them to tcg_rules
789 -- NB: built-in rules come in as IfaceRuleOut's, and
790 -- get added to tcg_rules right here by tcExtendRules
791 rules <- tcRules rule_decls ;
792 let { (src_rules, iface_rules) = partition isSrcRule rules } ;
793 tcExtendRules iface_rules $ do {
796 tcg_env <- getGblEnv ;
797 let { all_binds = tc_val_binds `AndMonoBinds`
798 inst_binds `AndMonoBinds`
799 cls_dm_binds `AndMonoBinds`
802 return (tcg_env, all_binds, src_rules, foe_decls)
807 tcTyClDecls :: RecTcGblEnv
811 -- tcTyClDecls deals with
812 -- type and class decls (some source, some imported)
813 -- interface signatures (checked lazily)
815 -- It returns the TcGblEnv for this module, and side-effects the
816 -- persistent compiler state to reflect the things imported from
819 tcTyClDecls unf_env tycl_decls
820 -- (unf_env :: RecTcGblEnv) is used for type-checking interface pragmas
821 -- which is done lazily [ie failure just drops the pragma
822 -- without having any global-failure effect].
825 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
826 -- an error we'd better stop now, to avoid a cascade
828 traceTc (text "TyCl1") `thenM_`
829 tcTyAndClassDecls tycl_decls `thenM` \ tycl_things ->
830 tcExtendGlobalEnv tycl_things $
832 -- Interface type signatures
833 -- We tie a knot so that the Ids read out of interfaces are in scope
834 -- when we read their pragmas.
835 -- What we rely on is that pragmas are typechecked lazily; if
836 -- any type errors are found (ie there's an inconsistency)
837 -- we silently discard the pragma
838 traceTc (text "TyCl2") `thenM_`
839 tcInterfaceSigs unf_env tycl_decls `thenM` \ sig_ids ->
840 tcExtendGlobalValEnv sig_ids $
842 getGblEnv -- Return the TcLocals environment
847 %************************************************************************
849 Load the old interface file for this module (unless
850 we have it aleady), and check whether it is up to date
853 %************************************************************************
856 checkOldIface :: HscEnv
857 -> PersistentCompilerState
859 -> FilePath -- Where the interface file is
860 -> Bool -- Source unchanged
861 -> Maybe ModIface -- Old interface from compilation manager, if any
862 -> IO (PersistentCompilerState, Maybe (RecompileRequired, Maybe ModIface))
863 -- Nothing <=> errors happened
865 checkOldIface hsc_env pcs mod iface_path source_unchanged maybe_iface
866 = do { showPass (hsc_dflags hsc_env)
867 ("Checking old interface for " ++ moduleUserString mod) ;
869 initTc hsc_env pcs mod
870 (check_old_iface iface_path source_unchanged maybe_iface)
873 check_old_iface iface_path source_unchanged maybe_iface
874 = -- CHECK WHETHER THE SOURCE HAS CHANGED
875 ifM (not source_unchanged)
876 (traceHiDiffs (nest 4 (text "Source file changed or recompilation check turned off")))
879 -- If the source has changed and we're in interactive mode, avoid reading
880 -- an interface; just return the one we might have been supplied with.
881 getGhciMode `thenM` \ ghci_mode ->
882 if (ghci_mode == Interactive) && not source_unchanged then
883 returnM (outOfDate, maybe_iface)
887 Just old_iface -> -- Use the one we already have
888 checkVersions source_unchanged old_iface `thenM` \ recomp ->
889 returnM (recomp, Just old_iface)
891 Nothing -- Try and read it from a file
892 -> getModule `thenM` \ this_mod ->
893 readIface this_mod iface_path False `thenM` \ read_result ->
895 Left err -> -- Old interface file not found, or garbled; give up
897 text "Cannot read old interface file:"
898 $$ nest 4 (text (showException err))) `thenM_`
899 returnM (outOfDate, Nothing)
901 Right parsed_iface ->
902 initRn (InterfaceMode this_mod)
903 (loadOldIface parsed_iface) `thenM` \ m_iface ->
904 checkVersions source_unchanged m_iface `thenM` \ recomp ->
905 returnM (recomp, Just m_iface)
909 %************************************************************************
911 Type-check and rename supporting declarations
912 This is used to deal with the free vars of a splice,
913 or derived code: slurp in the necessary declarations,
914 typecheck them, and add them to the EPS
916 %************************************************************************
919 importSupportingDecls :: FreeVars -> TcM TcGblEnv
920 -- Completely deal with the supporting imports needed
921 -- by the specified free-var set
922 importSupportingDecls fvs
923 = do { traceRn (text "Import supporting decls for" <+> ppr (nameSetToList fvs)) ;
924 decls <- slurpImpDecls fvs ;
925 traceRn (text "...namely:" <+> vcat (map ppr decls)) ;
926 typecheckIfaceDecls (mkGroup decls) }
928 typecheckIfaceDecls :: HsGroup Name -> TcM TcGblEnv
929 -- The decls are all interface-file declarations
930 -- Usually they are all from other modules, but when we are reading
931 -- this module's interface from a file, it's possible that some of
932 -- them are for the module being compiled.
933 -- That is why the tcExtendX functions need to do partitioning.
935 -- If all the decls are from other modules, the returned TcGblEnv
936 -- will have an empty tc_genv, but its tc_inst_env and tc_ist
937 -- caches may have been augmented.
938 typecheckIfaceDecls (HsGroup { hs_tyclds = tycl_decls,
939 hs_instds = inst_decls,
940 hs_ruleds = rule_decls })
941 = do { -- Typecheck the type, class, and interface-sig decls
942 tcg_env <- fixM (\ unf_env -> tcTyClDecls unf_env tycl_decls) ;
943 setGblEnv tcg_env $ do {
945 -- Typecheck the instance decls, and rules
946 -- Note that imported dictionary functions are already
947 -- in scope from the preceding tcTyClDecls
948 tcIfaceInstDecls inst_decls `thenM` \ dfuns ->
949 tcExtendInstEnv dfuns $
950 tcRules rule_decls `thenM` \ rules ->
951 tcExtendRules rules $
953 getGblEnv -- Return the environment
959 %*********************************************************
961 mkGlobalContext: make up an interactive context
963 Used for initialising the lexical environment
964 of the interactive read-eval-print loop
966 %*********************************************************
971 :: HscEnv -> PersistentCompilerState
972 -> [Module] -- Expose these modules' top-level scope
973 -> [Module] -- Expose these modules' exports only
974 -> IO (PersistentCompilerState, Maybe GlobalRdrEnv)
976 mkGlobalContext hsc_env pcs toplevs exports
977 = initTc hsc_env pcs iNTERACTIVE $ do {
979 toplev_envs <- mappM getTopLevScope toplevs ;
980 export_envs <- mappM getModuleExports exports ;
981 returnM (foldr plusGlobalRdrEnv emptyGlobalRdrEnv
982 (toplev_envs ++ export_envs))
985 getTopLevScope :: Module -> TcRn m GlobalRdrEnv
987 = do { iface <- loadInterface contextDoc (moduleName mod) (ImportByUser False) ;
988 case mi_globals iface of
989 Nothing -> panic "getTopLevScope"
990 Just env -> returnM env }
992 getModuleExports :: Module -> TcRn m GlobalRdrEnv
994 = do { iface <- loadInterface contextDoc (moduleName mod) (ImportByUser False) ;
995 returnM (foldl add emptyGlobalRdrEnv (mi_exports iface)) }
997 prov_fn n = NonLocalDef ImplicitImport
999 = plusGlobalRdrEnv env (mkGlobalRdrEnv mod True prov_fn avails NoDeprecs)
1001 contextDoc = text "context for compiling statements"
1007 -> PersistentCompilerState -- IN: persistent compiler state
1008 -> Module -- module to inspect
1009 -> Bool -- grab just the exports, or the whole toplev
1010 -> IO (PersistentCompilerState, Maybe [TyThing])
1012 getModuleContents hsc_env pcs mod exports_only
1013 = initTc hsc_env pcs iNTERACTIVE $ do {
1015 -- Load the interface if necessary (a home module will certainly
1016 -- alraedy be loaded, but a package module might not be)
1017 iface <- loadInterface contextDoc (moduleName mod) (ImportByUser False) ;
1019 let { export_names = availsToNameSet export_avails ;
1020 export_avails = [ avail | (mn, avails) <- mi_exports iface,
1021 avail <- avails ] } ;
1023 all_names <- if exports_only then
1025 else case mi_globals iface of {
1027 return (get_locals rdr_env) ;
1029 Nothing -> do { addErr (noRdrEnvErr mod) ;
1030 return export_names } } ;
1031 -- Invariant; we only have (not exports_only)
1032 -- for a home module so it must already be in the HIT
1033 -- So the Nothing case is a bug
1035 env <- importSupportingDecls all_names ;
1036 setGblEnv env (mappM tcLookupGlobal (nameSetToList all_names))
1039 -- Grab all the things from the global env that are locally def'd
1040 get_locals rdr_env = mkNameSet [ gre_name gre
1041 | elts <- rdrEnvElts rdr_env,
1044 -- Make a set because a name is often in the envt in
1045 -- both qualified and unqualified forms
1047 noRdrEnvErr mod = ptext SLIT("No top-level environment available for module")
1048 <+> quotes (ppr mod)
1052 %************************************************************************
1056 %************************************************************************
1060 = do { ghci_mode <- getGhciMode ;
1061 tcg_env <- getGblEnv ;
1062 check_main ghci_mode tcg_env
1065 check_main ghci_mode tcg_env
1066 -- If we are in module Main, check that 'main' is defined.
1067 -- It may be imported from another module, in which case
1068 -- we have to drag in its.
1070 -- Also form the definition
1071 -- $main = runIO main
1072 -- so we need to slurp in runIO too.
1074 -- ToDo: We have to return the main_name separately, because it's a
1075 -- bona fide 'use', and should be recorded as such, but the others
1078 -- Blimey: a whole page of code to do this...
1080 | mod_name /= mAIN_Name
1081 = return (tcg_env, emptyFVs)
1083 | not (main_RDR_Unqual `elemRdrEnv` rdr_env)
1084 = do { complain_no_main; return (tcg_env, emptyFVs) }
1087 = do { -- Check that 'main' is in scope
1088 -- It might be imported from another module!
1089 main_name <- lookupSrcName main_RDR_Unqual ;
1092 tcg_env <- importSupportingDecls (unitFV runIOName) ;
1093 setGblEnv tcg_env $ do {
1095 -- $main :: IO () = runIO main
1096 let { rhs = HsApp (HsVar runIOName) (HsVar main_name) } ;
1098 (main_bind, top_lie) <- getLIE (
1099 addSrcLoc (getSrcLoc main_name) $
1100 addErrCtxt mainCtxt $ do {
1101 (main_expr, ty) <- tcExpr_id rhs ;
1102 let { dollar_main_id = setIdLocalExported (mkLocalId dollarMainName ty) } ;
1103 return (VarMonoBind dollar_main_id main_expr)
1106 inst_binds <- tcSimplifyTop top_lie ;
1108 (ids, binds') <- zonkTopBinds (main_bind `andMonoBinds` inst_binds) ;
1110 let { tcg_env' = tcg_env {
1111 tcg_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) ids,
1112 tcg_binds = tcg_binds tcg_env `andMonoBinds` binds' } } ;
1114 return (tcg_env', unitFV main_name)
1117 mod_name = moduleName (tcg_mod tcg_env)
1118 rdr_env = tcg_rdr_env tcg_env
1120 main_RDR_Unqual :: RdrName
1121 main_RDR_Unqual = mkUnqual varName FSLIT("main")
1122 -- Don't get a RdrName from PrelNames.mainName, because
1123 -- nameRdrNamegets an Orig RdrName, and we want a Qual or Unqual one.
1124 -- An Unqual one will do just fine
1126 complain_no_main | ghci_mode == Interactive = return ()
1127 | otherwise = addErr noMainMsg
1128 -- In interactive mode, don't worry about the absence of 'main'
1130 mainCtxt = ptext SLIT("When checking the type of 'main'")
1131 noMainMsg = ptext SLIT("No 'main' defined in module Main")
1135 %************************************************************************
1139 %************************************************************************
1142 rnDump :: SDoc -> TcRn m ()
1143 -- Dump, with a banner, if -ddump-rn
1144 rnDump doc = dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc)
1146 tcDump :: TcGblEnv -> TcRn m ()
1148 = do { dflags <- getDOpts ;
1150 -- Dump short output if -ddump-types or -ddump-tc
1151 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1152 (dumpTcRn short_dump) ;
1154 -- Dump bindings if -ddump-tc
1155 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1158 short_dump = pprTcGblEnv env
1159 full_dump = ppr (tcg_binds env)
1160 -- NB: foreign x-d's have undefined's in their types;
1161 -- hence can't show the tc_fords
1164 = do { dflags <- getDOpts ;
1165 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1166 (dumpTcRn (pprModGuts mod_guts)) ;
1168 -- Dump bindings if -ddump-tc
1169 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1171 full_dump = pprCoreBindings (mg_binds mod_guts)
1173 -- It's unpleasant having both pprModGuts and pprModDetails here
1174 pprTcGblEnv :: TcGblEnv -> SDoc
1175 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1176 tcg_insts = dfun_ids,
1178 tcg_imports = imports })
1179 = vcat [ ppr_types dfun_ids type_env
1180 , ppr_insts dfun_ids
1181 , vcat (map ppr rules)
1182 , ppr_gen_tycons (typeEnvTyCons type_env)
1183 , ppr (moduleEnvElts (imp_dep_mods imports))
1184 , ppr (imp_dep_pkgs imports)]
1186 pprModGuts :: ModGuts -> SDoc
1187 pprModGuts (ModGuts { mg_types = type_env,
1189 = vcat [ ppr_types [] type_env,
1193 ppr_types :: [Var] -> TypeEnv -> SDoc
1194 ppr_types dfun_ids type_env
1195 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1197 ids = [id | id <- typeEnvIds type_env, want_sig id]
1198 want_sig id | opt_PprStyle_Debug = True
1199 | otherwise = isLocalId id &&
1200 isExternalName (idName id) &&
1201 not (id `elem` dfun_ids)
1202 -- isLocalId ignores data constructors, records selectors etc.
1203 -- The isExternalName ignores local dictionary and method bindings
1204 -- that the type checker has invented. Top-level user-defined things
1205 -- have External names.
1207 ppr_insts :: [Var] -> SDoc
1208 ppr_insts [] = empty
1209 ppr_insts dfun_ids = text "INSTANCES" $$ nest 4 (ppr_sigs dfun_ids)
1211 ppr_sigs :: [Var] -> SDoc
1213 -- Print type signatures
1214 -- Convert to HsType so that we get source-language style printing
1215 -- And sort by RdrName
1216 = vcat $ map ppr_sig $ sortLt lt_sig $
1217 [ (getRdrName id, toHsType (idType id))
1220 lt_sig (n1,_) (n2,_) = n1 < n2
1221 ppr_sig (n,t) = ppr n <+> dcolon <+> ppr t
1224 ppr_rules :: [IdCoreRule] -> SDoc
1225 ppr_rules [] = empty
1226 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1227 nest 4 (pprIdRules rs),
1230 ppr_gen_tycons [] = empty
1231 ppr_gen_tycons tcs = vcat [ptext SLIT("{-# Generic type constructor details"),
1232 vcat (map ppr_gen_tycon tcs),
1236 -- x&y are now Id's, not CoreExpr's
1238 | Just ep <- tyConGenInfo tycon
1239 = (ppr tycon <> colon) $$ nest 4 (ppr_ep ep)
1241 | otherwise = ppr tycon <> colon <+> ptext SLIT("Not derivable")
1244 = vcat [ ptext SLIT("Rep type:") <+> ppr (tcFunResultTy from_tau),
1245 ptext SLIT("From:") <+> ppr (unfoldingTemplate (idUnfolding from)),
1246 ptext SLIT("To:") <+> ppr (unfoldingTemplate (idUnfolding to))
1249 (_,from_tau) = tcSplitForAllTys (idType from)