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, tcIfaceAnnotations, tcIfaceGlobal, tcExtCoreBindings
15 #include "HsVersions.h"
42 import TysPrim ( anyTyConOfKind )
43 import BasicTypes ( Arity, nonRuleLoopBreaker )
48 import OccurAnal ( occurAnalyseExpr )
49 import Demand ( isBottomingSig )
71 An IfaceDecl is populated with RdrNames, and these are not renamed to
72 Names before typechecking, because there should be no scope errors etc.
74 -- For (b) consider: f = \$(...h....)
75 -- where h is imported, and calls f via an hi-boot file.
76 -- This is bad! But it is not seen as a staging error, because h
77 -- is indeed imported. We don't want the type-checker to black-hole
78 -- when simplifying and compiling the splice!
80 -- Simple solution: discard any unfolding that mentions a variable
81 -- bound in this module (and hence not yet processed).
82 -- The discarding happens when forkM finds a type error.
84 %************************************************************************
86 %* tcImportDecl is the key function for "faulting in" *
89 %************************************************************************
91 The main idea is this. We are chugging along type-checking source code, and
92 find a reference to GHC.Base.map. We call tcLookupGlobal, which doesn't find
93 it in the EPS type envt. So it
95 2 gets the decl for GHC.Base.map
96 3 typechecks it via tcIfaceDecl
97 4 and adds it to the type env in the EPS
99 Note that DURING STEP 4, we may find that map's type mentions a type
100 constructor that also
102 Notice that for imported things we read the current version from the EPS
103 mutable variable. This is important in situations like
105 where the code that e1 expands to might import some defns that
106 also turn out to be needed by the code that e2 expands to.
109 tcImportDecl :: Name -> TcM TyThing
110 -- Entry point for *source-code* uses of importDecl
112 | Just thing <- wiredInNameTyThing_maybe name
113 = do { when (needWiredInHomeIface thing)
114 (initIfaceTcRn (loadWiredInHomeIface name))
115 -- See Note [Loading instances for wired-in things]
118 = do { traceIf (text "tcImportDecl" <+> ppr name)
119 ; mb_thing <- initIfaceTcRn (importDecl name)
121 Succeeded thing -> return thing
122 Failed err -> failWithTc err }
124 importDecl :: Name -> IfM lcl (MaybeErr Message TyThing)
125 -- Get the TyThing for this Name from an interface file
126 -- It's not a wired-in thing -- the caller caught that
128 = ASSERT( not (isWiredInName name) )
131 -- Load the interface, which should populate the PTE
132 ; mb_iface <- ASSERT2( isExternalName name, ppr name )
133 loadInterface nd_doc (nameModule name) ImportBySystem
135 Failed err_msg -> return (Failed err_msg) ;
138 -- Now look it up again; this time we should find it
140 ; case lookupTypeEnv (eps_PTE eps) name of
141 Just thing -> return (Succeeded thing)
142 Nothing -> return (Failed not_found_msg)
145 nd_doc = ptext (sLit "Need decl for") <+> ppr name
146 not_found_msg = hang (ptext (sLit "Can't find interface-file declaration for") <+>
147 pprNameSpace (occNameSpace (nameOccName name)) <+> (ppr (nameOccName name)))
148 2 (vcat [ptext (sLit "Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
149 ptext (sLit "Use -ddump-if-trace to get an idea of which file caused the error")])
152 %************************************************************************
154 Checks for wired-in things
156 %************************************************************************
158 Note [Loading instances for wired-in things]
159 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
160 We need to make sure that we have at least *read* the interface files
161 for any module with an instance decl or RULE that we might want.
163 * If the instance decl is an orphan, we have a whole separate mechanism
166 * If the instance decl not an orphan, then the act of looking at the
167 TyCon or Class will force in the defining module for the
168 TyCon/Class, and hence the instance decl
170 * BUT, if the TyCon is a wired-in TyCon, we don't really need its interface;
171 but we must make sure we read its interface in case it has instances or
172 rules. That is what LoadIface.loadWiredInHomeInterface does. It's called
173 from TcIface.{tcImportDecl, checkWiredInTyCon, ifCheckWiredInThing}
175 * HOWEVER, only do this for TyCons. There are no wired-in Classes. There
176 are some wired-in Ids, but we don't want to load their interfaces. For
177 example, Control.Exception.Base.recSelError is wired in, but that module
178 is compiled late in the base library, and we don't want to force it to
179 load before it's been compiled!
181 All of this is done by the type checker. The renamer plays no role.
182 (It used to, but no longer.)
186 checkWiredInTyCon :: TyCon -> TcM ()
187 -- Ensure that the home module of the TyCon (and hence its instances)
188 -- are loaded. See Note [Loading instances for wired-in things]
189 -- It might not be a wired-in tycon (see the calls in TcUnify),
190 -- in which case this is a no-op.
192 | not (isWiredInName tc_name)
195 = do { mod <- getModule
196 ; ASSERT( isExternalName tc_name )
197 when (mod /= nameModule tc_name)
198 (initIfaceTcRn (loadWiredInHomeIface tc_name))
199 -- Don't look for (non-existent) Float.hi when
200 -- compiling Float.lhs, which mentions Float of course
201 -- A bit yukky to call initIfaceTcRn here
204 tc_name = tyConName tc
206 ifCheckWiredInThing :: TyThing -> IfL ()
207 -- Even though we are in an interface file, we want to make
208 -- sure the instances of a wired-in thing are loaded (imagine f :: Double -> Double)
209 -- Ditto want to ensure that RULES are loaded too
210 -- See Note [Loading instances for wired-in things]
211 ifCheckWiredInThing thing
212 = do { mod <- getIfModule
213 -- Check whether we are typechecking the interface for this
214 -- very module. E.g when compiling the base library in --make mode
215 -- we may typecheck GHC.Base.hi. At that point, GHC.Base is not in
216 -- the HPT, so without the test we'll demand-load it into the PIT!
217 -- C.f. the same test in checkWiredInTyCon above
218 ; let name = getName thing
219 ; ASSERT2( isExternalName name, ppr name )
220 when (needWiredInHomeIface thing && mod /= nameModule name)
221 (loadWiredInHomeIface name) }
223 needWiredInHomeIface :: TyThing -> Bool
224 -- Only for TyCons; see Note [Loading instances for wired-in things]
225 needWiredInHomeIface (ATyCon {}) = True
226 needWiredInHomeIface _ = False
229 %************************************************************************
231 Type-checking a complete interface
233 %************************************************************************
235 Suppose we discover we don't need to recompile. Then we must type
236 check the old interface file. This is a bit different to the
237 incremental type checking we do as we suck in interface files. Instead
238 we do things similarly as when we are typechecking source decls: we
239 bring into scope the type envt for the interface all at once, using a
240 knot. Remember, the decls aren't necessarily in dependency order --
241 and even if they were, the type decls might be mutually recursive.
244 typecheckIface :: ModIface -- Get the decls from here
245 -> TcRnIf gbl lcl ModDetails
247 = initIfaceTc iface $ \ tc_env_var -> do
248 -- The tc_env_var is freshly allocated, private to
249 -- type-checking this particular interface
250 { -- Get the right set of decls and rules. If we are compiling without -O
251 -- we discard pragmas before typechecking, so that we don't "see"
252 -- information that we shouldn't. From a versioning point of view
253 -- It's not actually *wrong* to do so, but in fact GHCi is unable
254 -- to handle unboxed tuples, so it must not see unfoldings.
255 ignore_prags <- doptM Opt_IgnoreInterfacePragmas
257 -- Typecheck the decls. This is done lazily, so that the knot-tying
258 -- within this single module work out right. In the If monad there is
259 -- no global envt for the current interface; instead, the knot is tied
260 -- through the if_rec_types field of IfGblEnv
261 ; names_w_things <- loadDecls ignore_prags (mi_decls iface)
262 ; let type_env = mkNameEnv names_w_things
263 ; writeMutVar tc_env_var type_env
265 -- Now do those rules, instances and annotations
266 ; insts <- mapM tcIfaceInst (mi_insts iface)
267 ; fam_insts <- mapM tcIfaceFamInst (mi_fam_insts iface)
268 ; rules <- tcIfaceRules ignore_prags (mi_rules iface)
269 ; anns <- tcIfaceAnnotations (mi_anns iface)
271 -- Vectorisation information
272 ; vect_info <- tcIfaceVectInfo (mi_module iface) type_env
276 ; exports <- ifaceExportNames (mi_exports iface)
279 ; traceIf (vcat [text "Finished typechecking interface for" <+> ppr (mi_module iface),
280 text "Type envt:" <+> ppr type_env])
281 ; return $ ModDetails { md_types = type_env
283 , md_fam_insts = fam_insts
286 , md_vect_info = vect_info
287 , md_exports = exports
293 %************************************************************************
295 Type and class declarations
297 %************************************************************************
300 tcHiBootIface :: HscSource -> Module -> TcRn ModDetails
301 -- Load the hi-boot iface for the module being compiled,
302 -- if it indeed exists in the transitive closure of imports
303 -- Return the ModDetails, empty if no hi-boot iface
304 tcHiBootIface hsc_src mod
305 | isHsBoot hsc_src -- Already compiling a hs-boot file
306 = return emptyModDetails
308 = do { traceIf (text "loadHiBootInterface" <+> ppr mod)
311 ; if not (isOneShot mode)
312 -- In --make and interactive mode, if this module has an hs-boot file
313 -- we'll have compiled it already, and it'll be in the HPT
315 -- We check wheher the interface is a *boot* interface.
316 -- It can happen (when using GHC from Visual Studio) that we
317 -- compile a module in TypecheckOnly mode, with a stable,
318 -- fully-populated HPT. In that case the boot interface isn't there
319 -- (it's been replaced by the mother module) so we can't check it.
320 -- And that's fine, because if M's ModInfo is in the HPT, then
321 -- it's been compiled once, and we don't need to check the boot iface
322 then do { hpt <- getHpt
323 ; case lookupUFM hpt (moduleName mod) of
324 Just info | mi_boot (hm_iface info)
325 -> return (hm_details info)
326 _ -> return emptyModDetails }
329 -- OK, so we're in one-shot mode.
330 -- In that case, we're read all the direct imports by now,
331 -- so eps_is_boot will record if any of our imports mention us by
332 -- way of hi-boot file
334 ; case lookupUFM (eps_is_boot eps) (moduleName mod) of {
335 Nothing -> return emptyModDetails ; -- The typical case
337 Just (_, False) -> failWithTc moduleLoop ;
338 -- Someone below us imported us!
339 -- This is a loop with no hi-boot in the way
341 Just (_mod, True) -> -- There's a hi-boot interface below us
343 do { read_result <- findAndReadIface
347 ; case read_result of
348 Failed err -> failWithTc (elaborate err)
349 Succeeded (iface, _path) -> typecheckIface iface
352 need = ptext (sLit "Need the hi-boot interface for") <+> ppr mod
353 <+> ptext (sLit "to compare against the Real Thing")
355 moduleLoop = ptext (sLit "Circular imports: module") <+> quotes (ppr mod)
356 <+> ptext (sLit "depends on itself")
358 elaborate err = hang (ptext (sLit "Could not find hi-boot interface for") <+>
359 quotes (ppr mod) <> colon) 4 err
363 %************************************************************************
365 Type and class declarations
367 %************************************************************************
369 When typechecking a data type decl, we *lazily* (via forkM) typecheck
370 the constructor argument types. This is in the hope that we may never
371 poke on those argument types, and hence may never need to load the
372 interface files for types mentioned in the arg types.
375 data Foo.S = MkS Baz.T
376 Mabye we can get away without even loading the interface for Baz!
378 This is not just a performance thing. Suppose we have
379 data Foo.S = MkS Baz.T
380 data Baz.T = MkT Foo.S
381 (in different interface files, of course).
382 Now, first we load and typecheck Foo.S, and add it to the type envt.
383 If we do explore MkS's argument, we'll load and typecheck Baz.T.
384 If we explore MkT's argument we'll find Foo.S already in the envt.
386 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
387 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
388 which isn't done yet.
390 All very cunning. However, there is a rather subtle gotcha which bit
391 me when developing this stuff. When we typecheck the decl for S, we
392 extend the type envt with S, MkS, and all its implicit Ids. Suppose
393 (a bug, but it happened) that the list of implicit Ids depended in
394 turn on the constructor arg types. Then the following sequence of
396 * we build a thunk <t> for the constructor arg tys
397 * we build a thunk for the extended type environment (depends on <t>)
398 * we write the extended type envt into the global EPS mutvar
400 Now we look something up in the type envt
402 * which reads the global type envt out of the global EPS mutvar
403 * but that depends in turn on <t>
405 It's subtle, because, it'd work fine if we typechecked the constructor args
406 eagerly -- they don't need the extended type envt. They just get the extended
407 type envt by accident, because they look at it later.
409 What this means is that the implicitTyThings MUST NOT DEPEND on any of
414 tcIfaceDecl :: Bool -- True <=> discard IdInfo on IfaceId bindings
417 tcIfaceDecl = tc_iface_decl NoParentTyCon
419 tc_iface_decl :: TyConParent -- For nested declarations
420 -> Bool -- True <=> discard IdInfo on IfaceId bindings
423 tc_iface_decl _ ignore_prags (IfaceId {ifName = occ_name, ifType = iface_type,
424 ifIdDetails = details, ifIdInfo = info})
425 = do { name <- lookupIfaceTop occ_name
426 ; ty <- tcIfaceType iface_type
427 ; details <- tcIdDetails ty details
428 ; info <- tcIdInfo ignore_prags name ty info
429 ; return (AnId (mkGlobalId details name ty info)) }
431 tc_iface_decl parent _ (IfaceData {ifName = occ_name,
433 ifCtxt = ctxt, ifGadtSyntax = gadt_syn,
436 ifFamInst = mb_family })
437 = bindIfaceTyVars_AT tv_bndrs $ \ tyvars -> do
438 { tc_name <- lookupIfaceTop occ_name
439 ; tycon <- fixM ( \ tycon -> do
440 { stupid_theta <- tcIfaceCtxt ctxt
441 ; cons <- tcIfaceDataCons tc_name tycon tyvars rdr_cons
442 ; mb_fam_inst <- tcFamInst mb_family
443 ; buildAlgTyCon tc_name tyvars stupid_theta cons is_rec
444 gadt_syn parent mb_fam_inst
446 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
447 ; return (ATyCon tycon) }
449 tc_iface_decl parent _ (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
450 ifSynRhs = mb_rhs_ty,
451 ifSynKind = kind, ifFamInst = mb_family})
452 = bindIfaceTyVars_AT tv_bndrs $ \ tyvars -> do
453 { tc_name <- lookupIfaceTop occ_name
454 ; rhs_kind <- tcIfaceType kind -- Note [Synonym kind loop]
455 ; rhs <- forkM (mk_doc tc_name) $
457 ; fam_info <- tcFamInst mb_family
458 ; tycon <- buildSynTyCon tc_name tyvars rhs rhs_kind parent fam_info
459 ; return (ATyCon tycon)
462 mk_doc n = ptext (sLit "Type syonym") <+> ppr n
463 tc_syn_rhs Nothing = return SynFamilyTyCon
464 tc_syn_rhs (Just ty) = do { rhs_ty <- tcIfaceType ty
465 ; return (SynonymTyCon rhs_ty) }
467 tc_iface_decl _parent ignore_prags
468 (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name,
469 ifTyVars = tv_bndrs, ifFDs = rdr_fds,
470 ifATs = rdr_ats, ifSigs = rdr_sigs,
472 -- ToDo: in hs-boot files we should really treat abstract classes specially,
473 -- as we do abstract tycons
474 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
475 { cls_name <- lookupIfaceTop occ_name
476 ; ctxt <- tcIfaceCtxt rdr_ctxt
477 ; sigs <- mapM tc_sig rdr_sigs
478 ; fds <- mapM tc_fd rdr_fds
479 ; cls <- fixM $ \ cls -> do
480 { ats <- mapM (tc_iface_decl (AssocFamilyTyCon cls) ignore_prags) rdr_ats
481 ; buildClass ignore_prags cls_name tyvars ctxt fds ats sigs tc_isrec }
482 ; return (AClass cls) }
484 tc_sig (IfaceClassOp occ dm rdr_ty)
485 = do { op_name <- lookupIfaceTop occ
486 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
487 -- Must be done lazily for just the same reason as the
488 -- type of a data con; to avoid sucking in types that
489 -- it mentions unless it's necessray to do so
490 ; return (op_name, dm, op_ty) }
492 mk_doc op_name op_ty = ptext (sLit "Class op") <+> sep [ppr op_name, ppr op_ty]
494 tc_fd (tvs1, tvs2) = do { tvs1' <- mapM tcIfaceTyVar tvs1
495 ; tvs2' <- mapM tcIfaceTyVar tvs2
496 ; return (tvs1', tvs2') }
498 tc_iface_decl _ _ (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
499 = do { name <- lookupIfaceTop rdr_name
500 ; return (ATyCon (mkForeignTyCon name ext_name
503 tcFamInst :: Maybe (IfaceTyCon, [IfaceType]) -> IfL (Maybe (TyCon, [Type]))
504 tcFamInst Nothing = return Nothing
505 tcFamInst (Just (fam, tys)) = do { famTyCon <- tcIfaceTyCon fam
506 ; insttys <- mapM tcIfaceType tys
507 ; return $ Just (famTyCon, insttys) }
509 tcIfaceDataCons :: Name -> TyCon -> [TyVar] -> IfaceConDecls -> IfL AlgTyConRhs
510 tcIfaceDataCons tycon_name tycon _ if_cons
512 IfAbstractTyCon -> return mkAbstractTyConRhs
513 IfOpenDataTyCon -> return DataFamilyTyCon
514 IfDataTyCon cons -> do { data_cons <- mapM tc_con_decl cons
515 ; return (mkDataTyConRhs data_cons) }
516 IfNewTyCon con -> do { data_con <- tc_con_decl con
517 ; mkNewTyConRhs tycon_name tycon data_con }
519 tc_con_decl (IfCon { ifConInfix = is_infix,
520 ifConUnivTvs = univ_tvs, ifConExTvs = ex_tvs,
521 ifConOcc = occ, ifConCtxt = ctxt, ifConEqSpec = spec,
522 ifConArgTys = args, ifConFields = field_lbls,
523 ifConStricts = stricts})
524 = bindIfaceTyVars univ_tvs $ \ univ_tyvars -> do
525 bindIfaceTyVars ex_tvs $ \ ex_tyvars -> do
526 { name <- lookupIfaceTop occ
527 ; eq_spec <- tcIfaceEqSpec spec
528 ; theta <- tcIfaceCtxt ctxt -- Laziness seems not worth the bother here
529 -- At one stage I thought that this context checking *had*
530 -- to be lazy, because of possible mutual recursion between the
531 -- type and the classe:
533 -- class Real a where { toRat :: a -> Ratio Integer }
534 -- data (Real a) => Ratio a = ...
535 -- But now I think that the laziness in checking class ops breaks
536 -- the loop, so no laziness needed
538 -- Read the argument types, but lazily to avoid faulting in
539 -- the component types unless they are really needed
540 ; arg_tys <- forkM (mk_doc name) (mapM tcIfaceType args)
541 ; lbl_names <- mapM lookupIfaceTop field_lbls
543 -- Remember, tycon is the representation tycon
544 ; let orig_res_ty = mkFamilyTyConApp tycon
545 (substTyVars (mkTopTvSubst eq_spec) univ_tyvars)
547 ; buildDataCon name is_infix {- Not infix -}
549 univ_tyvars ex_tyvars
551 arg_tys orig_res_ty tycon
553 mk_doc con_name = ptext (sLit "Constructor") <+> ppr con_name
555 tcIfaceEqSpec :: [(OccName, IfaceType)] -> IfL [(TyVar, Type)]
559 do_item (occ, if_ty) = do { tv <- tcIfaceTyVar (occNameFS occ)
560 ; ty <- tcIfaceType if_ty
564 Note [Synonym kind loop]
565 ~~~~~~~~~~~~~~~~~~~~~~~~
566 Notice that we eagerly grab the *kind* from the interface file, but
567 build a forkM thunk for the *rhs* (and family stuff). To see why,
568 consider this (Trac #2412)
570 M.hs: module M where { import X; data T = MkT S }
571 X.hs: module X where { import {-# SOURCE #-} M; type S = T }
572 M.hs-boot: module M where { data T }
574 When kind-checking M.hs we need S's kind. But we do not want to
575 find S's kind from (typeKind S-rhs), because we don't want to look at
576 S-rhs yet! Since S is imported from X.hi, S gets just one chance to
577 be defined, and we must not do that until we've finished with M.T.
579 Solution: record S's kind in the interface file; now we can safely
582 %************************************************************************
586 %************************************************************************
589 tcIfaceInst :: IfaceInst -> IfL Instance
590 tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
591 ifInstCls = cls, ifInstTys = mb_tcs })
592 = do { dfun <- forkM (ptext (sLit "Dict fun") <+> ppr dfun_occ) $
593 tcIfaceExtId dfun_occ
594 ; let mb_tcs' = map (fmap ifaceTyConName) mb_tcs
595 ; return (mkImportedInstance cls mb_tcs' dfun oflag) }
597 tcIfaceFamInst :: IfaceFamInst -> IfL FamInst
598 tcIfaceFamInst (IfaceFamInst { ifFamInstTyCon = tycon,
599 ifFamInstFam = fam, ifFamInstTys = mb_tcs })
600 -- { tycon' <- forkM (ptext (sLit "Inst tycon") <+> ppr tycon) $
601 -- the above line doesn't work, but this below does => CPP in Haskell = evil!
602 = do tycon' <- forkM (text ("Inst tycon") <+> ppr tycon) $
604 let mb_tcs' = map (fmap ifaceTyConName) mb_tcs
605 return (mkImportedFamInst fam mb_tcs' tycon')
609 %************************************************************************
613 %************************************************************************
615 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
616 are in the type environment. However, remember that typechecking a Rule may
617 (as a side effect) augment the type envt, and so we may need to iterate the process.
620 tcIfaceRules :: Bool -- True <=> ignore rules
623 tcIfaceRules ignore_prags if_rules
624 | ignore_prags = return []
625 | otherwise = mapM tcIfaceRule if_rules
627 tcIfaceRule :: IfaceRule -> IfL CoreRule
628 tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,
629 ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs,
631 = do { ~(bndrs', args', rhs') <-
632 -- Typecheck the payload lazily, in the hope it'll never be looked at
633 forkM (ptext (sLit "Rule") <+> ftext name) $
634 bindIfaceBndrs bndrs $ \ bndrs' ->
635 do { args' <- mapM tcIfaceExpr args
636 ; rhs' <- tcIfaceExpr rhs
637 ; return (bndrs', args', rhs') }
638 ; let mb_tcs = map ifTopFreeName args
639 ; return (Rule { ru_name = name, ru_fn = fn, ru_act = act,
640 ru_bndrs = bndrs', ru_args = args',
641 ru_rhs = occurAnalyseExpr rhs',
644 ru_local = False }) } -- An imported RULE is never for a local Id
645 -- or, even if it is (module loop, perhaps)
646 -- we'll just leave it in the non-local set
648 -- This function *must* mirror exactly what Rules.topFreeName does
649 -- We could have stored the ru_rough field in the iface file
650 -- but that would be redundant, I think.
651 -- The only wrinkle is that we must not be deceived by
652 -- type syononyms at the top of a type arg. Since
653 -- we can't tell at this point, we are careful not
654 -- to write them out in coreRuleToIfaceRule
655 ifTopFreeName :: IfaceExpr -> Maybe Name
656 ifTopFreeName (IfaceType (IfaceTyConApp tc _ )) = Just (ifaceTyConName tc)
657 ifTopFreeName (IfaceApp f _) = ifTopFreeName f
658 ifTopFreeName (IfaceExt n) = Just n
659 ifTopFreeName _ = Nothing
663 %************************************************************************
667 %************************************************************************
670 tcIfaceAnnotations :: [IfaceAnnotation] -> IfL [Annotation]
671 tcIfaceAnnotations = mapM tcIfaceAnnotation
673 tcIfaceAnnotation :: IfaceAnnotation -> IfL Annotation
674 tcIfaceAnnotation (IfaceAnnotation target serialized) = do
675 target' <- tcIfaceAnnTarget target
676 return $ Annotation {
677 ann_target = target',
678 ann_value = serialized
681 tcIfaceAnnTarget :: IfaceAnnTarget -> IfL (AnnTarget Name)
682 tcIfaceAnnTarget (NamedTarget occ) = do
683 name <- lookupIfaceTop occ
684 return $ NamedTarget name
685 tcIfaceAnnTarget (ModuleTarget mod) = do
686 return $ ModuleTarget mod
691 %************************************************************************
693 Vectorisation information
695 %************************************************************************
698 tcIfaceVectInfo :: Module -> TypeEnv -> IfaceVectInfo -> IfL VectInfo
699 tcIfaceVectInfo mod typeEnv (IfaceVectInfo
700 { ifaceVectInfoVar = vars
701 , ifaceVectInfoTyCon = tycons
702 , ifaceVectInfoTyConReuse = tyconsReuse
704 = do { vVars <- mapM vectVarMapping vars
705 ; tyConRes1 <- mapM vectTyConMapping tycons
706 ; tyConRes2 <- mapM vectTyConReuseMapping tyconsReuse
707 ; let (vTyCons, vDataCons, vPAs, vIsos) = unzip4 (tyConRes1 ++ tyConRes2)
709 { vectInfoVar = mkVarEnv vVars
710 , vectInfoTyCon = mkNameEnv vTyCons
711 , vectInfoDataCon = mkNameEnv (concat vDataCons)
712 , vectInfoPADFun = mkNameEnv vPAs
713 , vectInfoIso = mkNameEnv vIsos
718 = do { vName <- lookupOrig mod (mkVectOcc (nameOccName name))
719 ; let { var = lookupVar name
720 ; vVar = lookupVar vName
722 ; return (var, (var, vVar))
724 vectTyConMapping name
725 = do { vName <- lookupOrig mod (mkVectTyConOcc (nameOccName name))
726 ; paName <- lookupOrig mod (mkPADFunOcc (nameOccName name))
727 ; isoName <- lookupOrig mod (mkVectIsoOcc (nameOccName name))
728 ; let { tycon = lookupTyCon name
729 ; vTycon = lookupTyCon vName
730 ; paTycon = lookupVar paName
731 ; isoTycon = lookupVar isoName
733 ; vDataCons <- mapM vectDataConMapping (tyConDataCons tycon)
734 ; return ((name, (tycon, vTycon)), -- (T, T_v)
735 vDataCons, -- list of (Ci, Ci_v)
736 (vName, (vTycon, paTycon)), -- (T_v, paT)
737 (name, (tycon, isoTycon))) -- (T, isoT)
739 vectTyConReuseMapping name
740 = do { paName <- lookupOrig mod (mkPADFunOcc (nameOccName name))
741 ; isoName <- lookupOrig mod (mkVectIsoOcc (nameOccName name))
742 ; let { tycon = lookupTyCon name
743 ; paTycon = lookupVar paName
744 ; isoTycon = lookupVar isoName
745 ; vDataCons = [ (dataConName dc, (dc, dc))
746 | dc <- tyConDataCons tycon]
748 ; return ((name, (tycon, tycon)), -- (T, T)
749 vDataCons, -- list of (Ci, Ci)
750 (name, (tycon, paTycon)), -- (T, paT)
751 (name, (tycon, isoTycon))) -- (T, isoT)
753 vectDataConMapping datacon
754 = do { let name = dataConName datacon
755 ; vName <- lookupOrig mod (mkVectDataConOcc (nameOccName name))
756 ; let vDataCon = lookupDataCon vName
757 ; return (name, (datacon, vDataCon))
760 lookupVar name = case lookupTypeEnv typeEnv name of
761 Just (AnId var) -> var
763 panic "TcIface.tcIfaceVectInfo: not an id"
765 panic "TcIface.tcIfaceVectInfo: unknown name"
766 lookupTyCon name = case lookupTypeEnv typeEnv name of
767 Just (ATyCon tc) -> tc
769 panic "TcIface.tcIfaceVectInfo: not a tycon"
771 panic "TcIface.tcIfaceVectInfo: unknown name"
772 lookupDataCon name = case lookupTypeEnv typeEnv name of
773 Just (ADataCon dc) -> dc
775 panic "TcIface.tcIfaceVectInfo: not a datacon"
777 panic "TcIface.tcIfaceVectInfo: unknown name"
780 %************************************************************************
784 %************************************************************************
787 tcIfaceType :: IfaceType -> IfL Type
788 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
789 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
790 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
791 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkTyConApp tc' ts') }
792 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
793 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePred tcIfaceType st; return (PredTy st') }
794 tcIfaceType t@(IfaceCoConApp {}) = pprPanic "tcIfaceType" (ppr t)
796 tcIfaceTypes :: [IfaceType] -> IfL [Type]
797 tcIfaceTypes tys = mapM tcIfaceType tys
799 -----------------------------------------
800 tcIfacePred :: (IfaceType -> IfL a) -> IfacePredType -> IfL (Pred a)
801 tcIfacePred tc (IfaceClassP cls ts)
802 = do { cls' <- tcIfaceClass cls; ts' <- mapM tc ts; return (ClassP cls' ts') }
803 tcIfacePred tc (IfaceIParam ip t)
804 = do { ip' <- newIPName ip; t' <- tc t; return (IParam ip' t') }
805 tcIfacePred tc (IfaceEqPred t1 t2)
806 = do { t1' <- tc t1; t2' <- tc t2; return (EqPred t1' t2') }
808 -----------------------------------------
809 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
810 tcIfaceCtxt sts = mapM (tcIfacePred tcIfaceType) sts
813 %************************************************************************
817 %************************************************************************
820 tcIfaceCo :: IfaceType -> IfL Coercion
821 tcIfaceCo (IfaceTyVar n) = mkCoVarCo <$> tcIfaceCoVar n
822 tcIfaceCo (IfaceAppTy t1 t2) = mkAppCo <$> tcIfaceCo t1 <*> tcIfaceCo t2
823 tcIfaceCo (IfaceFunTy t1 t2) = mkFunCo <$> tcIfaceCo t1 <*> tcIfaceCo t2
824 tcIfaceCo (IfaceTyConApp tc ts) = mkTyConAppCo <$> tcIfaceTyCon tc <*> mapM tcIfaceCo ts
825 tcIfaceCo (IfaceCoConApp tc ts) = tcIfaceCoApp tc ts
826 tcIfaceCo (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' ->
827 mkForAllCo tv' <$> tcIfaceCo t
828 -- tcIfaceCo (IfacePredTy co) = mkPredCo <$> tcIfacePred tcIfaceCo co
829 tcIfaceCo (IfacePredTy _) = panic "tcIfaceCo"
831 tcIfaceCoApp :: IfaceCoCon -> [IfaceType] -> IfL Coercion
832 tcIfaceCoApp IfaceReflCo [t] = Refl <$> tcIfaceType t
833 tcIfaceCoApp (IfaceCoAx n) ts = AxiomInstCo <$> tcIfaceCoAxiom n <*> mapM tcIfaceCo ts
834 tcIfaceCoApp IfaceUnsafeCo [t1,t2] = UnsafeCo <$> tcIfaceType t1 <*> tcIfaceType t2
835 tcIfaceCoApp IfaceSymCo [t] = SymCo <$> tcIfaceCo t
836 tcIfaceCoApp IfaceTransCo [t1,t2] = TransCo <$> tcIfaceCo t1 <*> tcIfaceCo t2
837 tcIfaceCoApp IfaceInstCo [t1,t2] = InstCo <$> tcIfaceCo t1 <*> tcIfaceType t2
838 tcIfaceCoApp (IfaceNthCo d) [t] = NthCo d <$> tcIfaceCo t
839 tcIfaceCoApp cc ts = pprPanic "toIfaceCoApp" (ppr cc <+> ppr ts)
841 tcIfaceCoVar :: FastString -> IfL CoVar
842 tcIfaceCoVar = tcIfaceLclId
846 %************************************************************************
850 %************************************************************************
853 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
854 tcIfaceExpr (IfaceType ty)
855 = Type <$> tcIfaceType ty
857 tcIfaceExpr (IfaceCo co)
858 = Coercion <$> tcIfaceCo co
860 tcIfaceExpr (IfaceCast expr co)
861 = Cast <$> tcIfaceExpr expr <*> tcIfaceCo co
863 tcIfaceExpr (IfaceLcl name)
864 = Var <$> tcIfaceLclId name
866 tcIfaceExpr (IfaceTick modName tickNo)
867 = Var <$> tcIfaceTick modName tickNo
869 tcIfaceExpr (IfaceExt gbl)
870 = Var <$> tcIfaceExtId gbl
872 tcIfaceExpr (IfaceLit lit)
875 tcIfaceExpr (IfaceFCall cc ty) = do
876 ty' <- tcIfaceType ty
878 return (Var (mkFCallId u cc ty'))
880 tcIfaceExpr (IfaceTuple boxity args) = do
881 args' <- mapM tcIfaceExpr args
882 -- Put the missing type arguments back in
883 let con_args = map (Type . exprType) args' ++ args'
884 return (mkApps (Var con_id) con_args)
887 con_id = dataConWorkId (tupleCon boxity arity)
890 tcIfaceExpr (IfaceLam bndr body)
891 = bindIfaceBndr bndr $ \bndr' ->
892 Lam bndr' <$> tcIfaceExpr body
894 tcIfaceExpr (IfaceApp fun arg)
895 = App <$> tcIfaceExpr fun <*> tcIfaceExpr arg
897 tcIfaceExpr (IfaceCase scrut case_bndr alts) = do
898 scrut' <- tcIfaceExpr scrut
899 case_bndr_name <- newIfaceName (mkVarOccFS case_bndr)
901 scrut_ty = exprType scrut'
902 case_bndr' = mkLocalId case_bndr_name scrut_ty
903 tc_app = splitTyConApp scrut_ty
904 -- NB: Won't always succeed (polymoprhic case)
905 -- but won't be demanded in those cases
906 -- NB: not tcSplitTyConApp; we are looking at Core here
907 -- look through non-rec newtypes to find the tycon that
908 -- corresponds to the datacon in this case alternative
910 extendIfaceIdEnv [case_bndr'] $ do
911 alts' <- mapM (tcIfaceAlt scrut' tc_app) alts
912 return (Case scrut' case_bndr' (coreAltsType alts') alts')
914 tcIfaceExpr (IfaceLet (IfaceNonRec (IfLetBndr fs ty info) rhs) body)
915 = do { name <- newIfaceName (mkVarOccFS fs)
916 ; ty' <- tcIfaceType ty
917 ; id_info <- tcIdInfo False {- Don't ignore prags; we are inside one! -}
919 ; let id = mkLocalIdWithInfo name ty' id_info
920 ; rhs' <- tcIfaceExpr rhs
921 ; body' <- extendIfaceIdEnv [id] (tcIfaceExpr body)
922 ; return (Let (NonRec id rhs') body') }
924 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
925 = do { ids <- mapM tc_rec_bndr (map fst pairs)
926 ; extendIfaceIdEnv ids $ do
927 { pairs' <- zipWithM tc_pair pairs ids
928 ; body' <- tcIfaceExpr body
929 ; return (Let (Rec pairs') body') } }
931 tc_rec_bndr (IfLetBndr fs ty _)
932 = do { name <- newIfaceName (mkVarOccFS fs)
933 ; ty' <- tcIfaceType ty
934 ; return (mkLocalId name ty') }
935 tc_pair (IfLetBndr _ _ info, rhs) id
936 = do { rhs' <- tcIfaceExpr rhs
937 ; id_info <- tcIdInfo False {- Don't ignore prags; we are inside one! -}
938 (idName id) (idType id) info
939 ; return (setIdInfo id id_info, rhs') }
941 tcIfaceExpr (IfaceNote note expr) = do
942 expr' <- tcIfaceExpr expr
944 IfaceSCC cc -> return (Note (SCC cc) expr')
945 IfaceCoreNote n -> return (Note (CoreNote n) expr')
947 -------------------------
948 tcIfaceAlt :: CoreExpr -> (TyCon, [Type])
949 -> (IfaceConAlt, [FastString], IfaceExpr)
950 -> IfL (AltCon, [TyVar], CoreExpr)
951 tcIfaceAlt _ _ (IfaceDefault, names, rhs)
952 = ASSERT( null names ) do
953 rhs' <- tcIfaceExpr rhs
954 return (DEFAULT, [], rhs')
956 tcIfaceAlt _ _ (IfaceLitAlt lit, names, rhs)
957 = ASSERT( null names ) do
958 rhs' <- tcIfaceExpr rhs
959 return (LitAlt lit, [], rhs')
961 -- A case alternative is made quite a bit more complicated
962 -- by the fact that we omit type annotations because we can
963 -- work them out. True enough, but its not that easy!
964 tcIfaceAlt scrut (tycon, inst_tys) (IfaceDataAlt data_occ, arg_strs, rhs)
965 = do { con <- tcIfaceDataCon data_occ
966 ; when (debugIsOn && not (con `elem` tyConDataCons tycon))
967 (failIfM (ppr scrut $$ ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon)))
968 ; tcIfaceDataAlt con inst_tys arg_strs rhs }
970 tcIfaceAlt _ (tycon, inst_tys) (IfaceTupleAlt _boxity, arg_occs, rhs)
971 = ASSERT2( isTupleTyCon tycon, ppr tycon )
972 do { let [data_con] = tyConDataCons tycon
973 ; tcIfaceDataAlt data_con inst_tys arg_occs rhs }
975 tcIfaceDataAlt :: DataCon -> [Type] -> [FastString] -> IfaceExpr
976 -> IfL (AltCon, [TyVar], CoreExpr)
977 tcIfaceDataAlt con inst_tys arg_strs rhs
978 = do { us <- newUniqueSupply
979 ; let uniqs = uniqsFromSupply us
980 ; let (ex_tvs, arg_ids)
981 = dataConRepFSInstPat arg_strs uniqs con inst_tys
983 ; rhs' <- extendIfaceTyVarEnv ex_tvs $
984 extendIfaceIdEnv arg_ids $
986 ; return (DataAlt con, ex_tvs ++ arg_ids, rhs') }
991 tcExtCoreBindings :: [IfaceBinding] -> IfL [CoreBind] -- Used for external core
992 tcExtCoreBindings [] = return []
993 tcExtCoreBindings (b:bs) = do_one b (tcExtCoreBindings bs)
995 do_one :: IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
996 do_one (IfaceNonRec bndr rhs) thing_inside
997 = do { rhs' <- tcIfaceExpr rhs
998 ; bndr' <- newExtCoreBndr bndr
999 ; extendIfaceIdEnv [bndr'] $ do
1000 { core_binds <- thing_inside
1001 ; return (NonRec bndr' rhs' : core_binds) }}
1003 do_one (IfaceRec pairs) thing_inside
1004 = do { bndrs' <- mapM newExtCoreBndr bndrs
1005 ; extendIfaceIdEnv bndrs' $ do
1006 { rhss' <- mapM tcIfaceExpr rhss
1007 ; core_binds <- thing_inside
1008 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
1010 (bndrs,rhss) = unzip pairs
1014 %************************************************************************
1018 %************************************************************************
1021 tcIdDetails :: Type -> IfaceIdDetails -> IfL IdDetails
1022 tcIdDetails _ IfVanillaId = return VanillaId
1023 tcIdDetails ty (IfDFunId ns)
1024 = return (DFunId ns (isNewTyCon (classTyCon cls)))
1026 (_, _, cls, _) = tcSplitDFunTy ty
1028 tcIdDetails _ (IfRecSelId tc naughty)
1029 = do { tc' <- tcIfaceTyCon tc
1030 ; return (RecSelId { sel_tycon = tc', sel_naughty = naughty }) }
1032 tcIdInfo :: Bool -> Name -> Type -> IfaceIdInfo -> IfL IdInfo
1033 tcIdInfo ignore_prags name ty info
1034 | ignore_prags = return vanillaIdInfo
1035 | otherwise = case info of
1036 NoInfo -> return vanillaIdInfo
1037 HasInfo info -> foldlM tcPrag init_info info
1039 -- Set the CgInfo to something sensible but uninformative before
1040 -- we start; default assumption is that it has CAFs
1041 init_info = vanillaIdInfo
1043 tcPrag :: IdInfo -> IfaceInfoItem -> IfL IdInfo
1044 tcPrag info HsNoCafRefs = return (info `setCafInfo` NoCafRefs)
1045 tcPrag info (HsArity arity) = return (info `setArityInfo` arity)
1046 tcPrag info (HsStrictness str) = return (info `setStrictnessInfo` Just str)
1047 tcPrag info (HsInline prag) = return (info `setInlinePragInfo` prag)
1049 -- The next two are lazy, so they don't transitively suck stuff in
1050 tcPrag info (HsUnfold lb if_unf)
1051 = do { unf <- tcUnfolding name ty info if_unf
1052 ; let info1 | lb = info `setOccInfo` nonRuleLoopBreaker
1054 ; return (info1 `setUnfoldingInfoLazily` unf) }
1058 tcUnfolding :: Name -> Type -> IdInfo -> IfaceUnfolding -> IfL Unfolding
1059 tcUnfolding name _ info (IfCoreUnfold stable if_expr)
1060 = do { mb_expr <- tcPragExpr name if_expr
1061 ; let unf_src = if stable then InlineStable else InlineRhs
1062 ; return (case mb_expr of
1063 Nothing -> NoUnfolding
1064 Just expr -> mkUnfolding unf_src
1065 True {- Top level -}
1066 is_bottoming expr) }
1068 -- Strictness should occur before unfolding!
1069 is_bottoming = case strictnessInfo info of
1070 Just sig -> isBottomingSig sig
1073 tcUnfolding name _ _ (IfCompulsory if_expr)
1074 = do { mb_expr <- tcPragExpr name if_expr
1075 ; return (case mb_expr of
1076 Nothing -> NoUnfolding
1077 Just expr -> mkCompulsoryUnfolding expr) }
1079 tcUnfolding name _ _ (IfInlineRule arity unsat_ok boring_ok if_expr)
1080 = do { mb_expr <- tcPragExpr name if_expr
1081 ; return (case mb_expr of
1082 Nothing -> NoUnfolding
1083 Just expr -> mkCoreUnfolding InlineStable True expr arity
1084 (UnfWhen unsat_ok boring_ok))
1087 tcUnfolding name dfun_ty _ (IfDFunUnfold ops)
1088 = do { mb_ops1 <- forkM_maybe doc $ mapM tc_arg ops
1089 ; return (case mb_ops1 of
1090 Nothing -> noUnfolding
1091 Just ops1 -> mkDFunUnfolding dfun_ty ops1) }
1093 doc = text "Class ops for dfun" <+> ppr name
1094 tc_arg (DFunPolyArg e) = do { e' <- tcIfaceExpr e; return (DFunPolyArg e') }
1095 tc_arg (DFunConstArg e) = do { e' <- tcIfaceExpr e; return (DFunConstArg e') }
1096 tc_arg (DFunLamArg i) = return (DFunLamArg i)
1098 tcUnfolding name ty info (IfExtWrapper arity wkr)
1099 = tcIfaceWrapper name ty info arity (tcIfaceExtId wkr)
1100 tcUnfolding name ty info (IfLclWrapper arity wkr)
1101 = tcIfaceWrapper name ty info arity (tcIfaceLclId wkr)
1104 tcIfaceWrapper :: Name -> Type -> IdInfo -> Arity -> IfL Id -> IfL Unfolding
1105 tcIfaceWrapper name ty info arity get_worker
1106 = do { mb_wkr_id <- forkM_maybe doc get_worker
1107 ; us <- newUniqueSupply
1108 ; return (case mb_wkr_id of
1109 Nothing -> noUnfolding
1110 Just wkr_id -> make_inline_rule wkr_id us) }
1112 doc = text "Worker for" <+> ppr name
1114 make_inline_rule wkr_id us
1115 = mkWwInlineRule wkr_id
1116 (initUs_ us (mkWrapper ty strict_sig) wkr_id)
1119 -- Again we rely here on strictness info always appearing
1121 strict_sig = case strictnessInfo info of
1123 Nothing -> pprPanic "Worker info but no strictness for" (ppr name)
1126 For unfoldings we try to do the job lazily, so that we never type check
1127 an unfolding that isn't going to be looked at.
1130 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
1131 tcPragExpr name expr
1132 = forkM_maybe doc $ do
1133 core_expr' <- tcIfaceExpr expr
1135 -- Check for type consistency in the unfolding
1136 ifDOptM Opt_DoCoreLinting $ do
1137 in_scope <- get_in_scope
1138 case lintUnfolding noSrcLoc in_scope core_expr' of
1139 Nothing -> return ()
1140 Just fail_msg -> do { mod <- getIfModule
1141 ; pprPanic "Iface Lint failure"
1142 (vcat [ ptext (sLit "In interface for") <+> ppr mod
1143 , hang doc 2 fail_msg
1144 , ppr name <+> equals <+> ppr core_expr'
1145 , ptext (sLit "Iface expr =") <+> ppr expr ]) }
1148 doc = text "Unfolding of" <+> ppr name
1150 get_in_scope :: IfL [Var] -- Totally disgusting; but just for linting
1152 = do { (gbl_env, lcl_env) <- getEnvs
1153 ; rec_ids <- case if_rec_types gbl_env of
1154 Nothing -> return []
1155 Just (_, get_env) -> do
1156 { type_env <- setLclEnv () get_env
1157 ; return (typeEnvIds type_env) }
1158 ; return (varEnvElts (if_tv_env lcl_env) ++
1159 varEnvElts (if_id_env lcl_env) ++
1165 %************************************************************************
1167 Getting from Names to TyThings
1169 %************************************************************************
1172 tcIfaceGlobal :: Name -> IfL TyThing
1174 | Just thing <- wiredInNameTyThing_maybe name
1175 -- Wired-in things include TyCons, DataCons, and Ids
1176 = do { ifCheckWiredInThing thing; return thing }
1178 = do { env <- getGblEnv
1179 ; case if_rec_types env of { -- Note [Tying the knot]
1180 Just (mod, get_type_env)
1181 | nameIsLocalOrFrom mod name
1182 -> do -- It's defined in the module being compiled
1183 { type_env <- setLclEnv () get_type_env -- yuk
1184 ; case lookupNameEnv type_env name of
1185 Just thing -> return thing
1186 Nothing -> pprPanic "tcIfaceGlobal (local): not found:"
1187 (ppr name $$ ppr type_env) }
1191 { hsc_env <- getTopEnv
1192 ; mb_thing <- liftIO (lookupTypeHscEnv hsc_env name)
1193 ; case mb_thing of {
1194 Just thing -> return thing ;
1197 { mb_thing <- importDecl name -- It's imported; go get it
1199 Failed err -> failIfM err
1200 Succeeded thing -> return thing
1203 -- Note [Tying the knot]
1204 -- ~~~~~~~~~~~~~~~~~~~~~
1205 -- The if_rec_types field is used in two situations:
1207 -- a) Compiling M.hs, which indiretly imports Foo.hi, which mentions M.T
1208 -- Then we look up M.T in M's type environment, which is splatted into if_rec_types
1209 -- after we've built M's type envt.
1211 -- b) In ghc --make, during the upsweep, we encounter M.hs, whose interface M.hi
1212 -- is up to date. So we call typecheckIface on M.hi. This splats M.T into
1213 -- if_rec_types so that the (lazily typechecked) decls see all the other decls
1215 -- In case (b) it's important to do the if_rec_types check *before* looking in the HPT
1216 -- Because if M.hs also has M.hs-boot, M.T will *already be* in the HPT, but in its
1217 -- emasculated form (e.g. lacking data constructors).
1219 tcIfaceTyCon :: IfaceTyCon -> IfL TyCon
1220 tcIfaceTyCon IfaceIntTc = tcWiredInTyCon intTyCon
1221 tcIfaceTyCon IfaceBoolTc = tcWiredInTyCon boolTyCon
1222 tcIfaceTyCon IfaceCharTc = tcWiredInTyCon charTyCon
1223 tcIfaceTyCon IfaceListTc = tcWiredInTyCon listTyCon
1224 tcIfaceTyCon IfacePArrTc = tcWiredInTyCon parrTyCon
1225 tcIfaceTyCon (IfaceTupTc bx ar) = tcWiredInTyCon (tupleTyCon bx ar)
1226 tcIfaceTyCon (IfaceAnyTc kind) = do { tc_kind <- tcIfaceType kind
1227 ; tcWiredInTyCon (anyTyConOfKind tc_kind) }
1228 tcIfaceTyCon (IfaceTc name) = do { thing <- tcIfaceGlobal name
1229 ; return (check_tc (tyThingTyCon thing)) }
1232 | debugIsOn = case toIfaceTyCon tc of
1234 _ -> pprTrace "check_tc" (ppr tc) tc
1236 -- we should be okay just returning Kind constructors without extra loading
1237 tcIfaceTyCon IfaceLiftedTypeKindTc = return liftedTypeKindTyCon
1238 tcIfaceTyCon IfaceOpenTypeKindTc = return openTypeKindTyCon
1239 tcIfaceTyCon IfaceUnliftedTypeKindTc = return unliftedTypeKindTyCon
1240 tcIfaceTyCon IfaceArgTypeKindTc = return argTypeKindTyCon
1241 tcIfaceTyCon IfaceUbxTupleKindTc = return ubxTupleKindTyCon
1243 -- Even though we are in an interface file, we want to make
1244 -- sure the instances and RULES of this tycon are loaded
1245 -- Imagine: f :: Double -> Double
1246 tcWiredInTyCon :: TyCon -> IfL TyCon
1247 tcWiredInTyCon tc = do { ifCheckWiredInThing (ATyCon tc)
1250 tcIfaceClass :: Name -> IfL Class
1251 tcIfaceClass name = do { thing <- tcIfaceGlobal name
1252 ; return (tyThingClass thing) }
1254 tcIfaceCoAxiom :: Name -> IfL CoAxiom
1255 tcIfaceCoAxiom name = do { thing <- tcIfaceGlobal name
1256 ; return (tyThingCoAxiom thing) }
1258 tcIfaceDataCon :: Name -> IfL DataCon
1259 tcIfaceDataCon name = do { thing <- tcIfaceGlobal name
1261 ADataCon dc -> return dc
1262 _ -> pprPanic "tcIfaceExtDC" (ppr name$$ ppr thing) }
1264 tcIfaceExtId :: Name -> IfL Id
1265 tcIfaceExtId name = do { thing <- tcIfaceGlobal name
1267 AnId id -> return id
1268 _ -> pprPanic "tcIfaceExtId" (ppr name$$ ppr thing) }
1271 %************************************************************************
1275 %************************************************************************
1278 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
1279 bindIfaceBndr (IfaceIdBndr (fs, ty)) thing_inside
1280 = do { name <- newIfaceName (mkVarOccFS fs)
1281 ; ty' <- tcIfaceType ty
1282 ; let id = mkLocalId name ty'
1283 ; extendIfaceIdEnv [id] (thing_inside id) }
1284 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
1285 = bindIfaceTyVar bndr thing_inside
1287 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
1288 bindIfaceBndrs [] thing_inside = thing_inside []
1289 bindIfaceBndrs (b:bs) thing_inside
1290 = bindIfaceBndr b $ \ b' ->
1291 bindIfaceBndrs bs $ \ bs' ->
1292 thing_inside (b':bs')
1294 -----------------------
1295 newExtCoreBndr :: IfaceLetBndr -> IfL Id
1296 newExtCoreBndr (IfLetBndr var ty _) -- Ignoring IdInfo for now
1297 = do { mod <- getIfModule
1298 ; name <- newGlobalBinder mod (mkVarOccFS var) noSrcSpan
1299 ; ty' <- tcIfaceType ty
1300 ; return (mkLocalId name ty') }
1302 -----------------------
1303 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
1304 bindIfaceTyVar (occ,kind) thing_inside
1305 = do { name <- newIfaceName (mkTyVarOccFS occ)
1306 ; tyvar <- mk_iface_tyvar name kind
1307 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
1309 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
1310 bindIfaceTyVars bndrs thing_inside
1311 = do { names <- newIfaceNames (map mkTyVarOccFS occs)
1312 ; tyvars <- zipWithM mk_iface_tyvar names kinds
1313 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
1315 (occs,kinds) = unzip bndrs
1317 mk_iface_tyvar :: Name -> IfaceKind -> IfL TyVar
1318 mk_iface_tyvar name ifKind
1319 = do { kind <- tcIfaceType ifKind
1320 ; if isCoercionKind kind then
1321 return (Var.mkCoVar name kind)
1323 return (Var.mkTyVar name kind) }
1325 bindIfaceTyVars_AT :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
1326 -- Used for type variable in nested associated data/type declarations
1327 -- where some of the type variables are already in scope
1328 -- class C a where { data T a b }
1329 -- Here 'a' is in scope when we look at the 'data T'
1330 bindIfaceTyVars_AT [] thing_inside
1332 bindIfaceTyVars_AT (b@(tv_occ,_) : bs) thing_inside
1333 = bindIfaceTyVars_AT bs $ \ bs' ->
1334 do { mb_tv <- lookupIfaceTyVar tv_occ
1336 Just b' -> thing_inside (b':bs')
1337 Nothing -> bindIfaceTyVar b $ \ b' ->
1338 thing_inside (b':bs') }