2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
6 Type checking of type signatures in interface files
10 tcImportDecl, checkWiredInTyCon, tcHiBootIface, typecheckIface,
11 tcIfaceDecl, tcIfaceInst, tcIfaceFamInst, tcIfaceRules,
12 tcIfaceVectInfo, tcIfaceGlobal, tcExtCoreBindings
15 #include "HsVersions.h"
65 An IfaceDecl is populated with RdrNames, and these are not renamed to
66 Names before typechecking, because there should be no scope errors etc.
68 -- For (b) consider: f = $(...h....)
69 -- where h is imported, and calls f via an hi-boot file.
70 -- This is bad! But it is not seen as a staging error, because h
71 -- is indeed imported. We don't want the type-checker to black-hole
72 -- when simplifying and compiling the splice!
74 -- Simple solution: discard any unfolding that mentions a variable
75 -- bound in this module (and hence not yet processed).
76 -- The discarding happens when forkM finds a type error.
78 %************************************************************************
80 %* tcImportDecl is the key function for "faulting in" *
83 %************************************************************************
85 The main idea is this. We are chugging along type-checking source code, and
86 find a reference to GHC.Base.map. We call tcLookupGlobal, which doesn't find
87 it in the EPS type envt. So it
89 2 gets the decl for GHC.Base.map
90 3 typechecks it via tcIfaceDecl
91 4 and adds it to the type env in the EPS
93 Note that DURING STEP 4, we may find that map's type mentions a type
96 Notice that for imported things we read the current version from the EPS
97 mutable variable. This is important in situations like
99 where the code that e1 expands to might import some defns that
100 also turn out to be needed by the code that e2 expands to.
103 tcImportDecl :: Name -> TcM TyThing
104 -- Entry point for *source-code* uses of importDecl
106 | Just thing <- wiredInNameTyThing_maybe name
107 = do { initIfaceTcRn (loadWiredInHomeIface name)
110 = do { traceIf (text "tcImportDecl" <+> ppr name)
111 ; mb_thing <- initIfaceTcRn (importDecl name)
113 Succeeded thing -> return thing
114 Failed err -> failWithTc err }
116 checkWiredInTyCon :: TyCon -> TcM ()
117 -- Ensure that the home module of the TyCon (and hence its instances)
118 -- are loaded. It might not be a wired-in tycon (see the calls in TcUnify),
119 -- in which case this is a no-op.
121 | not (isWiredInName tc_name)
124 = do { mod <- getModule
125 ; unless (mod == nameModule tc_name)
126 (initIfaceTcRn (loadWiredInHomeIface tc_name))
127 -- Don't look for (non-existent) Float.hi when
128 -- compiling Float.lhs, which mentions Float of course
129 -- A bit yukky to call initIfaceTcRn here
132 tc_name = tyConName tc
134 importDecl :: Name -> IfM lcl (MaybeErr Message TyThing)
135 -- Get the TyThing for this Name from an interface file
136 -- It's not a wired-in thing -- the caller caught that
138 = ASSERT( not (isWiredInName name) )
141 -- Load the interface, which should populate the PTE
142 ; mb_iface <- loadInterface nd_doc (nameModule name) ImportBySystem
144 Failed err_msg -> return (Failed err_msg) ;
145 Succeeded iface -> do
147 -- Now look it up again; this time we should find it
149 ; case lookupTypeEnv (eps_PTE eps) name of
150 Just thing -> return (Succeeded thing)
151 Nothing -> return (Failed not_found_msg)
154 nd_doc = ptext SLIT("Need decl for") <+> ppr name
155 not_found_msg = hang (ptext SLIT("Can't find interface-file declaration for") <+>
156 pprNameSpace (occNameSpace (nameOccName name)) <+> ppr name)
157 2 (vcat [ptext SLIT("Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
158 ptext SLIT("Use -ddump-if-trace to get an idea of which file caused the error")])
161 %************************************************************************
163 Type-checking a complete interface
165 %************************************************************************
167 Suppose we discover we don't need to recompile. Then we must type
168 check the old interface file. This is a bit different to the
169 incremental type checking we do as we suck in interface files. Instead
170 we do things similarly as when we are typechecking source decls: we
171 bring into scope the type envt for the interface all at once, using a
172 knot. Remember, the decls aren't necessarily in dependency order --
173 and even if they were, the type decls might be mutually recursive.
176 typecheckIface :: ModIface -- Get the decls from here
177 -> TcRnIf gbl lcl ModDetails
179 = initIfaceTc iface $ \ tc_env_var -> do
180 -- The tc_env_var is freshly allocated, private to
181 -- type-checking this particular interface
182 { -- Get the right set of decls and rules. If we are compiling without -O
183 -- we discard pragmas before typechecking, so that we don't "see"
184 -- information that we shouldn't. From a versioning point of view
185 -- It's not actually *wrong* to do so, but in fact GHCi is unable
186 -- to handle unboxed tuples, so it must not see unfoldings.
187 ignore_prags <- doptM Opt_IgnoreInterfacePragmas
189 -- Typecheck the decls. This is done lazily, so that the knot-tying
190 -- within this single module work out right. In the If monad there is
191 -- no global envt for the current interface; instead, the knot is tied
192 -- through the if_rec_types field of IfGblEnv
193 ; names_w_things <- loadDecls ignore_prags (mi_decls iface)
194 ; let type_env = mkNameEnv names_w_things
195 ; writeMutVar tc_env_var type_env
197 -- Now do those rules and instances
198 ; insts <- mapM tcIfaceInst (mi_insts iface)
199 ; fam_insts <- mapM tcIfaceFamInst (mi_fam_insts iface)
200 ; rules <- tcIfaceRules ignore_prags (mi_rules iface)
202 -- Vectorisation information
203 ; vect_info <- tcIfaceVectInfo (mi_module iface) type_env
207 ; exports <- ifaceExportNames (mi_exports iface)
210 ; traceIf (vcat [text "Finished typechecking interface for" <+> ppr (mi_module iface),
211 text "Type envt:" <+> ppr type_env])
212 ; return $ ModDetails { md_types = type_env
214 , md_fam_insts = fam_insts
216 , md_vect_info = vect_info
217 , md_exports = exports
218 , md_modBreaks = emptyModBreaks
224 %************************************************************************
226 Type and class declarations
228 %************************************************************************
231 tcHiBootIface :: HscSource -> Module -> TcRn ModDetails
232 -- Load the hi-boot iface for the module being compiled,
233 -- if it indeed exists in the transitive closure of imports
234 -- Return the ModDetails, empty if no hi-boot iface
235 tcHiBootIface hsc_src mod
236 | isHsBoot hsc_src -- Already compiling a hs-boot file
237 = return emptyModDetails
239 = do { traceIf (text "loadHiBootInterface" <+> ppr mod)
242 ; if not (isOneShot mode)
243 -- In --make and interactive mode, if this module has an hs-boot file
244 -- we'll have compiled it already, and it'll be in the HPT
246 -- We check wheher the interface is a *boot* interface.
247 -- It can happen (when using GHC from Visual Studio) that we
248 -- compile a module in TypecheckOnly mode, with a stable,
249 -- fully-populated HPT. In that case the boot interface isn't there
250 -- (it's been replaced by the mother module) so we can't check it.
251 -- And that's fine, because if M's ModInfo is in the HPT, then
252 -- it's been compiled once, and we don't need to check the boot iface
253 then do { hpt <- getHpt
254 ; case lookupUFM hpt (moduleName mod) of
255 Just info | mi_boot (hm_iface info)
256 -> return (hm_details info)
257 other -> return emptyModDetails }
260 -- OK, so we're in one-shot mode.
261 -- In that case, we're read all the direct imports by now,
262 -- so eps_is_boot will record if any of our imports mention us by
263 -- way of hi-boot file
265 ; case lookupUFM (eps_is_boot eps) (moduleName mod) of {
266 Nothing -> return emptyModDetails ; -- The typical case
268 Just (_, False) -> failWithTc moduleLoop ;
269 -- Someone below us imported us!
270 -- This is a loop with no hi-boot in the way
272 Just (_mod, True) -> -- There's a hi-boot interface below us
274 do { read_result <- findAndReadIface
278 ; case read_result of
279 Failed err -> failWithTc (elaborate err)
280 Succeeded (iface, _path) -> typecheckIface iface
283 need = ptext SLIT("Need the hi-boot interface for") <+> ppr mod
284 <+> ptext SLIT("to compare against the Real Thing")
286 moduleLoop = ptext SLIT("Circular imports: module") <+> quotes (ppr mod)
287 <+> ptext SLIT("depends on itself")
289 elaborate err = hang (ptext SLIT("Could not find hi-boot interface for") <+>
290 quotes (ppr mod) <> colon) 4 err
294 %************************************************************************
296 Type and class declarations
298 %************************************************************************
300 When typechecking a data type decl, we *lazily* (via forkM) typecheck
301 the constructor argument types. This is in the hope that we may never
302 poke on those argument types, and hence may never need to load the
303 interface files for types mentioned in the arg types.
306 data Foo.S = MkS Baz.T
307 Mabye we can get away without even loading the interface for Baz!
309 This is not just a performance thing. Suppose we have
310 data Foo.S = MkS Baz.T
311 data Baz.T = MkT Foo.S
312 (in different interface files, of course).
313 Now, first we load and typecheck Foo.S, and add it to the type envt.
314 If we do explore MkS's argument, we'll load and typecheck Baz.T.
315 If we explore MkT's argument we'll find Foo.S already in the envt.
317 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
318 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
319 which isn't done yet.
321 All very cunning. However, there is a rather subtle gotcha which bit
322 me when developing this stuff. When we typecheck the decl for S, we
323 extend the type envt with S, MkS, and all its implicit Ids. Suppose
324 (a bug, but it happened) that the list of implicit Ids depended in
325 turn on the constructor arg types. Then the following sequence of
327 * we build a thunk <t> for the constructor arg tys
328 * we build a thunk for the extended type environment (depends on <t>)
329 * we write the extended type envt into the global EPS mutvar
331 Now we look something up in the type envt
333 * which reads the global type envt out of the global EPS mutvar
334 * but that depends in turn on <t>
336 It's subtle, because, it'd work fine if we typechecked the constructor args
337 eagerly -- they don't need the extended type envt. They just get the extended
338 type envt by accident, because they look at it later.
340 What this means is that the implicitTyThings MUST NOT DEPEND on any of
345 tcIfaceDecl :: Bool -- True <=> discard IdInfo on IfaceId bindings
349 tcIfaceDecl ignore_prags (IfaceId {ifName = occ_name, ifType = iface_type, ifIdInfo = info})
350 = do { name <- lookupIfaceTop occ_name
351 ; ty <- tcIfaceType iface_type
352 ; info <- tcIdInfo ignore_prags name ty info
353 ; return (AnId (mkVanillaGlobal name ty info)) }
355 tcIfaceDecl ignore_prags
356 (IfaceData {ifName = occ_name,
358 ifCtxt = ctxt, ifGadtSyntax = gadt_syn,
361 ifGeneric = want_generic,
362 ifFamInst = mb_family })
363 = do { tc_name <- lookupIfaceTop occ_name
364 ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
366 { tycon <- fixM ( \ tycon -> do
367 { stupid_theta <- tcIfaceCtxt ctxt
370 Nothing -> return Nothing
372 do { famTyCon <- tcIfaceTyCon fam
373 ; insttys <- mapM tcIfaceType tys
374 ; return $ Just (famTyCon, insttys)
376 ; cons <- tcIfaceDataCons tc_name tycon tyvars rdr_cons
377 ; buildAlgTyCon tc_name tyvars stupid_theta
378 cons is_rec want_generic gadt_syn famInst
380 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
381 ; return (ATyCon tycon)
384 tcIfaceDecl ignore_prags
385 (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
386 ifOpenSyn = isOpen, ifSynRhs = rdr_rhs_ty,
387 ifFamInst = mb_family})
388 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
389 { tc_name <- lookupIfaceTop occ_name
390 ; rhs_tyki <- tcIfaceType rdr_rhs_ty
391 ; let rhs = if isOpen then OpenSynTyCon rhs_tyki Nothing
392 else SynonymTyCon rhs_tyki
393 ; famInst <- case mb_family of
394 Nothing -> return Nothing
396 do { famTyCon <- tcIfaceTyCon fam
397 ; insttys <- mapM tcIfaceType tys
398 ; return $ Just (famTyCon, insttys)
400 ; tycon <- buildSynTyCon tc_name tyvars rhs famInst
401 ; return $ ATyCon tycon
404 tcIfaceDecl ignore_prags
405 (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name,
406 ifTyVars = tv_bndrs, ifFDs = rdr_fds,
407 ifATs = rdr_ats, ifSigs = rdr_sigs,
409 -- ToDo: in hs-boot files we should really treat abstract classes specially,
410 -- as we do abstract tycons
411 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
412 { cls_name <- lookupIfaceTop occ_name
413 ; ctxt <- tcIfaceCtxt rdr_ctxt
414 ; sigs <- mappM tc_sig rdr_sigs
415 ; fds <- mappM tc_fd rdr_fds
416 ; ats' <- mappM (tcIfaceDecl ignore_prags) rdr_ats
417 ; let ats = zipWith setTyThingPoss ats' (map ifTyVars rdr_ats)
418 ; cls <- buildClass cls_name tyvars ctxt fds ats sigs tc_isrec
419 ; return (AClass cls) }
421 tc_sig (IfaceClassOp occ dm rdr_ty)
422 = do { op_name <- lookupIfaceTop occ
423 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
424 -- Must be done lazily for just the same reason as the
425 -- type of a data con; to avoid sucking in types that
426 -- it mentions unless it's necessray to do so
427 ; return (op_name, dm, op_ty) }
429 mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
431 tc_fd (tvs1, tvs2) = do { tvs1' <- mappM tcIfaceTyVar tvs1
432 ; tvs2' <- mappM tcIfaceTyVar tvs2
433 ; return (tvs1', tvs2') }
435 -- For each AT argument compute the position of the corresponding class
436 -- parameter in the class head. This will later serve as a permutation
437 -- vector when checking the validity of instance declarations.
438 setTyThingPoss (ATyCon tycon) atTyVars =
439 let classTyVars = map fst tv_bndrs
441 . map ((`elemIndex` classTyVars) . fst)
443 -- There will be no Nothing, as we already passed renaming
445 ATyCon (setTyConArgPoss tycon poss)
446 setTyThingPoss _ _ = panic "TcIface.setTyThingPoss"
448 tcIfaceDecl ignore_prags (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
449 = do { name <- lookupIfaceTop rdr_name
450 ; return (ATyCon (mkForeignTyCon name ext_name
453 tcIfaceDataCons tycon_name tycon tc_tyvars if_cons
455 IfAbstractTyCon -> return mkAbstractTyConRhs
456 IfOpenDataTyCon -> return mkOpenDataTyConRhs
457 IfDataTyCon cons -> do { data_cons <- mappM tc_con_decl cons
458 ; return (mkDataTyConRhs data_cons) }
459 IfNewTyCon con -> do { data_con <- tc_con_decl con
460 ; mkNewTyConRhs tycon_name tycon data_con }
462 tc_con_decl (IfCon { ifConInfix = is_infix,
463 ifConUnivTvs = univ_tvs, ifConExTvs = ex_tvs,
464 ifConOcc = occ, ifConCtxt = ctxt, ifConEqSpec = spec,
465 ifConArgTys = args, ifConFields = field_lbls,
466 ifConStricts = stricts})
467 = bindIfaceTyVars univ_tvs $ \ univ_tyvars -> do
468 bindIfaceTyVars ex_tvs $ \ ex_tyvars -> do
469 { name <- lookupIfaceTop occ
470 ; eq_spec <- tcIfaceEqSpec spec
471 ; theta <- tcIfaceCtxt ctxt -- Laziness seems not worth the bother here
472 -- At one stage I thought that this context checking *had*
473 -- to be lazy, because of possible mutual recursion between the
474 -- type and the classe:
476 -- class Real a where { toRat :: a -> Ratio Integer }
477 -- data (Real a) => Ratio a = ...
478 -- But now I think that the laziness in checking class ops breaks
479 -- the loop, so no laziness needed
481 -- Read the argument types, but lazily to avoid faulting in
482 -- the component types unless they are really needed
483 ; arg_tys <- forkM (mk_doc name) (mappM tcIfaceType args)
484 ; lbl_names <- mappM lookupIfaceTop field_lbls
486 ; buildDataCon name is_infix {- Not infix -}
488 univ_tyvars ex_tyvars
492 mk_doc con_name = ptext SLIT("Constructor") <+> ppr con_name
497 do_item (occ, if_ty) = do { tv <- tcIfaceTyVar (occNameFS occ)
498 ; ty <- tcIfaceType if_ty
503 %************************************************************************
507 %************************************************************************
510 tcIfaceInst :: IfaceInst -> IfL Instance
511 tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
512 ifInstCls = cls, ifInstTys = mb_tcs,
514 = do { dfun <- forkM (ptext SLIT("Dict fun") <+> ppr dfun_occ) $
515 tcIfaceExtId dfun_occ
516 ; let mb_tcs' = map (fmap ifaceTyConName) mb_tcs
517 ; return (mkImportedInstance cls mb_tcs' dfun oflag) }
519 tcIfaceFamInst :: IfaceFamInst -> IfL FamInst
520 tcIfaceFamInst (IfaceFamInst { ifFamInstTyCon = tycon,
521 ifFamInstFam = fam, ifFamInstTys = mb_tcs })
522 -- = do { tycon' <- forkM (ptext SLIT("Inst tycon") <+> ppr tycon) $
523 -- ^^^this line doesn't work, but vvv this does => CPP in Haskell = evil!
524 = do { tycon' <- forkM (text ("Inst tycon") <+> ppr tycon) $
526 ; let mb_tcs' = map (fmap ifaceTyConName) mb_tcs
527 ; return (mkImportedFamInst fam mb_tcs' tycon') }
531 %************************************************************************
535 %************************************************************************
537 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
538 are in the type environment. However, remember that typechecking a Rule may
539 (as a side effect) augment the type envt, and so we may need to iterate the process.
542 tcIfaceRules :: Bool -- True <=> ignore rules
545 tcIfaceRules ignore_prags if_rules
546 | ignore_prags = return []
547 | otherwise = mapM tcIfaceRule if_rules
549 tcIfaceRule :: IfaceRule -> IfL CoreRule
550 tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,
551 ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs,
553 = do { ~(bndrs', args', rhs') <-
554 -- Typecheck the payload lazily, in the hope it'll never be looked at
555 forkM (ptext SLIT("Rule") <+> ftext name) $
556 bindIfaceBndrs bndrs $ \ bndrs' ->
557 do { args' <- mappM tcIfaceExpr args
558 ; rhs' <- tcIfaceExpr rhs
559 ; return (bndrs', args', rhs') }
560 ; let mb_tcs = map ifTopFreeName args
562 ; returnM (Rule { ru_name = name, ru_fn = fn, ru_act = act,
563 ru_bndrs = bndrs', ru_args = args',
566 ru_local = False }) } -- An imported RULE is never for a local Id
567 -- or, even if it is (module loop, perhaps)
568 -- we'll just leave it in the non-local set
570 -- This function *must* mirror exactly what Rules.topFreeName does
571 -- We could have stored the ru_rough field in the iface file
572 -- but that would be redundant, I think.
573 -- The only wrinkle is that we must not be deceived by
574 -- type syononyms at the top of a type arg. Since
575 -- we can't tell at this point, we are careful not
576 -- to write them out in coreRuleToIfaceRule
577 ifTopFreeName :: IfaceExpr -> Maybe Name
578 ifTopFreeName (IfaceType (IfaceTyConApp tc _ )) = Just (ifaceTyConName tc)
579 ifTopFreeName (IfaceApp f a) = ifTopFreeName f
580 ifTopFreeName (IfaceExt n) = Just n
581 ifTopFreeName other = Nothing
585 %************************************************************************
587 Vectorisation information
589 %************************************************************************
592 tcIfaceVectInfo :: Module -> TypeEnv -> IfaceVectInfo -> IfL VectInfo
593 tcIfaceVectInfo mod typeEnv (IfaceVectInfo names)
594 = do { ccVars <- mapM ccMapping names
595 ; return $ VectInfo (mkVarEnv ccVars)
599 = do { ccName <- lookupOrig mod (mkCloOcc (nameOccName name))
600 ; let { var = lookup name
601 ; ccVar = lookup ccName
603 ; return (var, (var, ccVar))
605 lookup name = case lookupTypeEnv typeEnv name of
606 Just (AnId var) -> var
608 panic "TcIface.tcIfaceVectInfo: wrong TyThing"
610 panic "TcIface.tcIfaceVectInfo: unknown name"
613 %************************************************************************
617 %************************************************************************
620 tcIfaceType :: IfaceType -> IfL Type
621 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
622 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
623 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
624 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkTyConApp tc' ts') }
625 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
626 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
628 tcIfaceTypes tys = mapM tcIfaceType tys
630 -----------------------------------------
631 tcIfacePredType :: IfacePredType -> IfL PredType
632 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
633 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
634 tcIfacePredType (IfaceEqPred t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (EqPred t1' t2') }
636 -----------------------------------------
637 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
638 tcIfaceCtxt sts = mappM tcIfacePredType sts
642 %************************************************************************
646 %************************************************************************
649 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
650 tcIfaceExpr (IfaceType ty)
651 = tcIfaceType ty `thenM` \ ty' ->
654 tcIfaceExpr (IfaceLcl name)
655 = tcIfaceLclId name `thenM` \ id ->
658 tcIfaceExpr (IfaceExt gbl)
659 = tcIfaceExtId gbl `thenM` \ id ->
662 tcIfaceExpr (IfaceLit lit)
665 tcIfaceExpr (IfaceFCall cc ty)
666 = tcIfaceType ty `thenM` \ ty' ->
667 newUnique `thenM` \ u ->
668 returnM (Var (mkFCallId u cc ty'))
670 tcIfaceExpr (IfaceTuple boxity args)
671 = mappM tcIfaceExpr args `thenM` \ args' ->
673 -- Put the missing type arguments back in
674 con_args = map (Type . exprType) args' ++ args'
676 returnM (mkApps (Var con_id) con_args)
679 con_id = dataConWorkId (tupleCon boxity arity)
682 tcIfaceExpr (IfaceLam bndr body)
683 = bindIfaceBndr bndr $ \ bndr' ->
684 tcIfaceExpr body `thenM` \ body' ->
685 returnM (Lam bndr' body')
687 tcIfaceExpr (IfaceApp fun arg)
688 = tcIfaceExpr fun `thenM` \ fun' ->
689 tcIfaceExpr arg `thenM` \ arg' ->
690 returnM (App fun' arg')
692 tcIfaceExpr (IfaceCase scrut case_bndr ty alts)
693 = tcIfaceExpr scrut `thenM` \ scrut' ->
694 newIfaceName (mkVarOccFS case_bndr) `thenM` \ case_bndr_name ->
696 scrut_ty = exprType scrut'
697 case_bndr' = mkLocalId case_bndr_name scrut_ty
698 tc_app = splitTyConApp scrut_ty
699 -- NB: Won't always succeed (polymoprhic case)
700 -- but won't be demanded in those cases
701 -- NB: not tcSplitTyConApp; we are looking at Core here
702 -- look through non-rec newtypes to find the tycon that
703 -- corresponds to the datacon in this case alternative
705 extendIfaceIdEnv [case_bndr'] $
706 mappM (tcIfaceAlt tc_app) alts `thenM` \ alts' ->
707 tcIfaceType ty `thenM` \ ty' ->
708 returnM (Case scrut' case_bndr' ty' alts')
710 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body)
711 = do { rhs' <- tcIfaceExpr rhs
712 ; id <- tcIfaceLetBndr bndr
713 ; body' <- extendIfaceIdEnv [id] (tcIfaceExpr body)
714 ; return (Let (NonRec id rhs') body') }
716 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
717 = do { ids <- mapM tcIfaceLetBndr bndrs
718 ; extendIfaceIdEnv ids $ do
719 { rhss' <- mapM tcIfaceExpr rhss
720 ; body' <- tcIfaceExpr body
721 ; return (Let (Rec (ids `zip` rhss')) body') } }
723 (bndrs, rhss) = unzip pairs
725 tcIfaceExpr (IfaceCast expr co) = do
726 expr' <- tcIfaceExpr expr
727 co' <- tcIfaceType co
728 returnM (Cast expr' co')
730 tcIfaceExpr (IfaceNote note expr)
731 = tcIfaceExpr expr `thenM` \ expr' ->
733 IfaceInlineMe -> returnM (Note InlineMe expr')
734 IfaceSCC cc -> returnM (Note (SCC cc) expr')
735 IfaceCoreNote n -> returnM (Note (CoreNote n) expr')
737 -------------------------
738 tcIfaceAlt _ (IfaceDefault, names, rhs)
739 = ASSERT( null names )
740 tcIfaceExpr rhs `thenM` \ rhs' ->
741 returnM (DEFAULT, [], rhs')
743 tcIfaceAlt _ (IfaceLitAlt lit, names, rhs)
744 = ASSERT( null names )
745 tcIfaceExpr rhs `thenM` \ rhs' ->
746 returnM (LitAlt lit, [], rhs')
748 -- A case alternative is made quite a bit more complicated
749 -- by the fact that we omit type annotations because we can
750 -- work them out. True enough, but its not that easy!
751 tcIfaceAlt (tycon, inst_tys) (IfaceDataAlt data_occ, arg_strs, rhs)
752 = do { con <- tcIfaceDataCon data_occ
753 ; ASSERT2( con `elem` tyConDataCons tycon,
754 ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon) )
755 tcIfaceDataAlt con inst_tys arg_strs rhs }
757 tcIfaceAlt (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
758 = ASSERT( isTupleTyCon tycon )
759 do { let [data_con] = tyConDataCons tycon
760 ; tcIfaceDataAlt data_con inst_tys arg_occs rhs }
762 tcIfaceDataAlt con inst_tys arg_strs rhs
763 = do { us <- newUniqueSupply
764 ; let uniqs = uniqsFromSupply us
765 ; let (ex_tvs, co_tvs, arg_ids)
766 = dataConRepFSInstPat arg_strs uniqs con inst_tys
767 all_tvs = ex_tvs ++ co_tvs
769 ; rhs' <- extendIfaceTyVarEnv all_tvs $
770 extendIfaceIdEnv arg_ids $
772 ; return (DataAlt con, all_tvs ++ arg_ids, rhs') }
777 tcExtCoreBindings :: [IfaceBinding] -> IfL [CoreBind] -- Used for external core
778 tcExtCoreBindings [] = return []
779 tcExtCoreBindings (b:bs) = do_one b (tcExtCoreBindings bs)
781 do_one :: IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
782 do_one (IfaceNonRec bndr rhs) thing_inside
783 = do { rhs' <- tcIfaceExpr rhs
784 ; bndr' <- newExtCoreBndr bndr
785 ; extendIfaceIdEnv [bndr'] $ do
786 { core_binds <- thing_inside
787 ; return (NonRec bndr' rhs' : core_binds) }}
789 do_one (IfaceRec pairs) thing_inside
790 = do { bndrs' <- mappM newExtCoreBndr bndrs
791 ; extendIfaceIdEnv bndrs' $ do
792 { rhss' <- mappM tcIfaceExpr rhss
793 ; core_binds <- thing_inside
794 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
796 (bndrs,rhss) = unzip pairs
800 %************************************************************************
804 %************************************************************************
807 tcIdInfo :: Bool -> Name -> Type -> IfaceIdInfo -> IfL IdInfo
808 tcIdInfo ignore_prags name ty info
809 | ignore_prags = return vanillaIdInfo
810 | otherwise = case info of
811 NoInfo -> return vanillaIdInfo
812 HasInfo info -> foldlM tcPrag init_info info
814 -- Set the CgInfo to something sensible but uninformative before
815 -- we start; default assumption is that it has CAFs
816 init_info = vanillaIdInfo
818 tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
819 tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
820 tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
822 -- The next two are lazy, so they don't transitively suck stuff in
823 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
824 tcPrag info (HsInline inline_prag) = returnM (info `setInlinePragInfo` inline_prag)
825 tcPrag info (HsUnfold expr)
826 = tcPragExpr name expr `thenM` \ maybe_expr' ->
828 -- maybe_expr' doesn't get looked at if the unfolding
829 -- is never inspected; so the typecheck doesn't even happen
830 unfold_info = case maybe_expr' of
831 Nothing -> noUnfolding
832 Just expr' -> mkTopUnfolding expr'
834 returnM (info `setUnfoldingInfoLazily` unfold_info)
838 tcWorkerInfo ty info wkr arity
839 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId wkr)
841 -- We return without testing maybe_wkr_id, but as soon as info is
842 -- looked at we will test it. That's ok, because its outside the
843 -- knot; and there seems no big reason to further defer the
844 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
845 -- over the unfolding until it's actually used does seem worth while.)
846 ; us <- newUniqueSupply
848 ; returnM (case mb_wkr_id of
850 Just wkr_id -> add_wkr_info us wkr_id info) }
852 doc = text "Worker for" <+> ppr wkr
853 add_wkr_info us wkr_id info
854 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
855 `setWorkerInfo` HasWorker wkr_id arity
857 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
859 -- We are relying here on strictness info always appearing
860 -- before worker info, fingers crossed ....
861 strict_sig = case newStrictnessInfo info of
863 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr)
866 For unfoldings we try to do the job lazily, so that we never type check
867 an unfolding that isn't going to be looked at.
870 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
873 tcIfaceExpr expr `thenM` \ core_expr' ->
875 -- Check for type consistency in the unfolding
876 ifOptM Opt_DoCoreLinting (
877 get_in_scope_ids `thenM` \ in_scope ->
878 case lintUnfolding noSrcLoc in_scope core_expr' of
879 Nothing -> returnM ()
880 Just fail_msg -> pprPanic "Iface Lint failure" (hang doc 2 fail_msg)
885 doc = text "Unfolding of" <+> ppr name
886 get_in_scope_ids -- Urgh; but just for linting
888 do { env <- getGblEnv
889 ; case if_rec_types env of {
890 Nothing -> return [] ;
891 Just (_, get_env) -> do
892 { type_env <- get_env
893 ; return (typeEnvIds type_env) }}}
898 %************************************************************************
900 Getting from Names to TyThings
902 %************************************************************************
905 tcIfaceGlobal :: Name -> IfL TyThing
907 | Just thing <- wiredInNameTyThing_maybe name
908 -- Wired-in things include TyCons, DataCons, and Ids
909 = do { ifCheckWiredInThing name; return thing }
911 = do { (eps,hpt) <- getEpsAndHpt
913 ; case lookupType dflags hpt (eps_PTE eps) name of {
914 Just thing -> return thing ;
918 ; case if_rec_types env of {
919 Just (mod, get_type_env)
920 | nameIsLocalOrFrom mod name
921 -> do -- It's defined in the module being compiled
922 { type_env <- setLclEnv () get_type_env -- yuk
923 ; case lookupNameEnv type_env name of
924 Just thing -> return thing
925 Nothing -> pprPanic "tcIfaceGlobal (local): not found:"
926 (ppr name $$ ppr type_env) }
930 { mb_thing <- importDecl name -- It's imported; go get it
932 Failed err -> failIfM err
933 Succeeded thing -> return thing
936 ifCheckWiredInThing :: Name -> IfL ()
937 -- Even though we are in an interface file, we want to make
938 -- sure the instances of a wired-in thing are loaded (imagine f :: Double -> Double)
939 -- Ditto want to ensure that RULES are loaded too
940 ifCheckWiredInThing name
941 = do { mod <- getIfModule
942 -- Check whether we are typechecking the interface for this
943 -- very module. E.g when compiling the base library in --make mode
944 -- we may typecheck GHC.Base.hi. At that point, GHC.Base is not in
945 -- the HPT, so without the test we'll demand-load it into the PIT!
946 -- C.f. the same test in checkWiredInTyCon above
947 ; unless (mod == nameModule name)
948 (loadWiredInHomeIface name) }
950 tcIfaceTyCon :: IfaceTyCon -> IfL TyCon
951 tcIfaceTyCon IfaceIntTc = tcWiredInTyCon intTyCon
952 tcIfaceTyCon IfaceBoolTc = tcWiredInTyCon boolTyCon
953 tcIfaceTyCon IfaceCharTc = tcWiredInTyCon charTyCon
954 tcIfaceTyCon IfaceListTc = tcWiredInTyCon listTyCon
955 tcIfaceTyCon IfacePArrTc = tcWiredInTyCon parrTyCon
956 tcIfaceTyCon (IfaceTupTc bx ar) = tcWiredInTyCon (tupleTyCon bx ar)
957 tcIfaceTyCon (IfaceTc name) = do { thing <- tcIfaceGlobal name
958 ; return (check_tc (tyThingTyCon thing)) }
961 check_tc tc = case toIfaceTyCon tc of
963 other -> pprTrace "check_tc" (ppr tc) tc
967 -- we should be okay just returning Kind constructors without extra loading
968 tcIfaceTyCon IfaceLiftedTypeKindTc = return liftedTypeKindTyCon
969 tcIfaceTyCon IfaceOpenTypeKindTc = return openTypeKindTyCon
970 tcIfaceTyCon IfaceUnliftedTypeKindTc = return unliftedTypeKindTyCon
971 tcIfaceTyCon IfaceArgTypeKindTc = return argTypeKindTyCon
972 tcIfaceTyCon IfaceUbxTupleKindTc = return ubxTupleKindTyCon
974 -- Even though we are in an interface file, we want to make
975 -- sure the instances and RULES of this tycon are loaded
976 -- Imagine: f :: Double -> Double
977 tcWiredInTyCon :: TyCon -> IfL TyCon
978 tcWiredInTyCon tc = do { ifCheckWiredInThing (tyConName tc)
981 tcIfaceClass :: Name -> IfL Class
982 tcIfaceClass name = do { thing <- tcIfaceGlobal name
983 ; return (tyThingClass thing) }
985 tcIfaceDataCon :: Name -> IfL DataCon
986 tcIfaceDataCon name = do { thing <- tcIfaceGlobal name
988 ADataCon dc -> return dc
989 other -> pprPanic "tcIfaceExtDC" (ppr name$$ ppr thing) }
991 tcIfaceExtId :: Name -> IfL Id
992 tcIfaceExtId name = do { thing <- tcIfaceGlobal name
995 other -> pprPanic "tcIfaceExtId" (ppr name$$ ppr thing) }
998 %************************************************************************
1002 %************************************************************************
1005 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
1006 bindIfaceBndr (IfaceIdBndr (fs, ty)) thing_inside
1007 = do { name <- newIfaceName (mkVarOccFS fs)
1008 ; ty' <- tcIfaceType ty
1009 ; let id = mkLocalId name ty'
1010 ; extendIfaceIdEnv [id] (thing_inside id) }
1011 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
1012 = bindIfaceTyVar bndr thing_inside
1014 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
1015 bindIfaceBndrs [] thing_inside = thing_inside []
1016 bindIfaceBndrs (b:bs) thing_inside
1017 = bindIfaceBndr b $ \ b' ->
1018 bindIfaceBndrs bs $ \ bs' ->
1019 thing_inside (b':bs')
1021 -----------------------
1022 tcIfaceLetBndr (IfLetBndr fs ty info)
1023 = do { name <- newIfaceName (mkVarOccFS fs)
1024 ; ty' <- tcIfaceType ty
1026 NoInfo -> return (mkLocalId name ty')
1027 HasInfo i -> return (mkLocalIdWithInfo name ty' (tc_info i)) }
1029 -- Similar to tcIdInfo, but much simpler
1030 tc_info [] = vanillaIdInfo
1031 tc_info (HsInline p : i) = tc_info i `setInlinePragInfo` p
1032 tc_info (HsArity a : i) = tc_info i `setArityInfo` a
1033 tc_info (HsStrictness s : i) = tc_info i `setAllStrictnessInfo` Just s
1034 tc_info (other : i) = pprTrace "tcIfaceLetBndr: discarding unexpected IdInfo"
1035 (ppr other) (tc_info i)
1037 -----------------------
1038 newExtCoreBndr :: IfaceLetBndr -> IfL Id
1039 newExtCoreBndr (IfLetBndr var ty _) -- Ignoring IdInfo for now
1040 = do { mod <- getIfModule
1041 ; name <- newGlobalBinder mod (mkVarOccFS var) noSrcSpan
1042 ; ty' <- tcIfaceType ty
1043 ; return (mkLocalId name ty') }
1045 -----------------------
1046 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
1047 bindIfaceTyVar (occ,kind) thing_inside
1048 = do { name <- newIfaceName (mkTyVarOcc occ)
1049 ; tyvar <- mk_iface_tyvar name kind
1050 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
1052 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
1053 bindIfaceTyVars bndrs thing_inside
1054 = do { names <- newIfaceNames (map mkTyVarOcc occs)
1055 ; tyvars <- TcRnMonad.zipWithM mk_iface_tyvar names kinds
1056 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
1058 (occs,kinds) = unzip bndrs
1060 mk_iface_tyvar :: Name -> IfaceKind -> IfL TyVar
1061 mk_iface_tyvar name ifKind
1062 = do { kind <- tcIfaceType ifKind
1063 ; if isCoercionKind kind then
1064 return (Var.mkCoVar name kind)
1066 return (Var.mkTyVar name kind) }