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"
56 import BasicTypes (Arity)
69 An IfaceDecl is populated with RdrNames, and these are not renamed to
70 Names before typechecking, because there should be no scope errors etc.
72 -- For (b) consider: f = \$(...h....)
73 -- where h is imported, and calls f via an hi-boot file.
74 -- This is bad! But it is not seen as a staging error, because h
75 -- is indeed imported. We don't want the type-checker to black-hole
76 -- when simplifying and compiling the splice!
78 -- Simple solution: discard any unfolding that mentions a variable
79 -- bound in this module (and hence not yet processed).
80 -- The discarding happens when forkM finds a type error.
82 %************************************************************************
84 %* tcImportDecl is the key function for "faulting in" *
87 %************************************************************************
89 The main idea is this. We are chugging along type-checking source code, and
90 find a reference to GHC.Base.map. We call tcLookupGlobal, which doesn't find
91 it in the EPS type envt. So it
93 2 gets the decl for GHC.Base.map
94 3 typechecks it via tcIfaceDecl
95 4 and adds it to the type env in the EPS
97 Note that DURING STEP 4, we may find that map's type mentions a type
100 Notice that for imported things we read the current version from the EPS
101 mutable variable. This is important in situations like
103 where the code that e1 expands to might import some defns that
104 also turn out to be needed by the code that e2 expands to.
107 tcImportDecl :: Name -> TcM TyThing
108 -- Entry point for *source-code* uses of importDecl
110 | Just thing <- wiredInNameTyThing_maybe name
111 = do { initIfaceTcRn (loadWiredInHomeIface name)
112 -- See Note [Loading instances] in LoadIface
115 = do { traceIf (text "tcImportDecl" <+> ppr name)
116 ; mb_thing <- initIfaceTcRn (importDecl name)
118 Succeeded thing -> return thing
119 Failed err -> failWithTc err }
121 checkWiredInTyCon :: TyCon -> TcM ()
122 -- Ensure that the home module of the TyCon (and hence its instances)
123 -- are loaded. See See Note [Loading instances] in LoadIface
124 -- It might not be a wired-in tycon (see the calls in TcUnify),
125 -- in which case this is a no-op.
127 | not (isWiredInName tc_name)
130 = do { mod <- getModule
131 ; ASSERT( isExternalName tc_name )
132 unless (mod == nameModule tc_name)
133 (initIfaceTcRn (loadWiredInHomeIface tc_name))
134 -- Don't look for (non-existent) Float.hi when
135 -- compiling Float.lhs, which mentions Float of course
136 -- A bit yukky to call initIfaceTcRn here
139 tc_name = tyConName tc
141 importDecl :: Name -> IfM lcl (MaybeErr Message TyThing)
142 -- Get the TyThing for this Name from an interface file
143 -- It's not a wired-in thing -- the caller caught that
145 = ASSERT( not (isWiredInName name) )
148 -- Load the interface, which should populate the PTE
149 ; mb_iface <- ASSERT2( isExternalName name, ppr name )
150 loadInterface nd_doc (nameModule name) ImportBySystem
152 Failed err_msg -> return (Failed err_msg) ;
155 -- Now look it up again; this time we should find it
157 ; case lookupTypeEnv (eps_PTE eps) name of
158 Just thing -> return (Succeeded thing)
159 Nothing -> return (Failed not_found_msg)
162 nd_doc = ptext (sLit "Need decl for") <+> ppr name
163 not_found_msg = hang (ptext (sLit "Can't find interface-file declaration for") <+>
164 pprNameSpace (occNameSpace (nameOccName name)) <+> ppr name)
165 2 (vcat [ptext (sLit "Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
166 ptext (sLit "Use -ddump-if-trace to get an idea of which file caused the error")])
169 %************************************************************************
171 Type-checking a complete interface
173 %************************************************************************
175 Suppose we discover we don't need to recompile. Then we must type
176 check the old interface file. This is a bit different to the
177 incremental type checking we do as we suck in interface files. Instead
178 we do things similarly as when we are typechecking source decls: we
179 bring into scope the type envt for the interface all at once, using a
180 knot. Remember, the decls aren't necessarily in dependency order --
181 and even if they were, the type decls might be mutually recursive.
184 typecheckIface :: ModIface -- Get the decls from here
185 -> TcRnIf gbl lcl ModDetails
187 = initIfaceTc iface $ \ tc_env_var -> do
188 -- The tc_env_var is freshly allocated, private to
189 -- type-checking this particular interface
190 { -- Get the right set of decls and rules. If we are compiling without -O
191 -- we discard pragmas before typechecking, so that we don't "see"
192 -- information that we shouldn't. From a versioning point of view
193 -- It's not actually *wrong* to do so, but in fact GHCi is unable
194 -- to handle unboxed tuples, so it must not see unfoldings.
195 ignore_prags <- doptM Opt_IgnoreInterfacePragmas
197 -- Typecheck the decls. This is done lazily, so that the knot-tying
198 -- within this single module work out right. In the If monad there is
199 -- no global envt for the current interface; instead, the knot is tied
200 -- through the if_rec_types field of IfGblEnv
201 ; names_w_things <- loadDecls ignore_prags (mi_decls iface)
202 ; let type_env = mkNameEnv names_w_things
203 ; writeMutVar tc_env_var type_env
205 -- Now do those rules, instances and annotations
206 ; insts <- mapM tcIfaceInst (mi_insts iface)
207 ; fam_insts <- mapM tcIfaceFamInst (mi_fam_insts iface)
208 ; rules <- tcIfaceRules ignore_prags (mi_rules iface)
209 ; anns <- tcIfaceAnnotations (mi_anns iface)
211 -- Vectorisation information
212 ; vect_info <- tcIfaceVectInfo (mi_module iface) type_env
216 ; exports <- ifaceExportNames (mi_exports iface)
219 ; traceIf (vcat [text "Finished typechecking interface for" <+> ppr (mi_module iface),
220 text "Type envt:" <+> ppr type_env])
221 ; return $ ModDetails { md_types = type_env
223 , md_fam_insts = fam_insts
226 , md_vect_info = vect_info
227 , md_exports = exports
233 %************************************************************************
235 Type and class declarations
237 %************************************************************************
240 tcHiBootIface :: HscSource -> Module -> TcRn ModDetails
241 -- Load the hi-boot iface for the module being compiled,
242 -- if it indeed exists in the transitive closure of imports
243 -- Return the ModDetails, empty if no hi-boot iface
244 tcHiBootIface hsc_src mod
245 | isHsBoot hsc_src -- Already compiling a hs-boot file
246 = return emptyModDetails
248 = do { traceIf (text "loadHiBootInterface" <+> ppr mod)
251 ; if not (isOneShot mode)
252 -- In --make and interactive mode, if this module has an hs-boot file
253 -- we'll have compiled it already, and it'll be in the HPT
255 -- We check wheher the interface is a *boot* interface.
256 -- It can happen (when using GHC from Visual Studio) that we
257 -- compile a module in TypecheckOnly mode, with a stable,
258 -- fully-populated HPT. In that case the boot interface isn't there
259 -- (it's been replaced by the mother module) so we can't check it.
260 -- And that's fine, because if M's ModInfo is in the HPT, then
261 -- it's been compiled once, and we don't need to check the boot iface
262 then do { hpt <- getHpt
263 ; case lookupUFM hpt (moduleName mod) of
264 Just info | mi_boot (hm_iface info)
265 -> return (hm_details info)
266 _ -> return emptyModDetails }
269 -- OK, so we're in one-shot mode.
270 -- In that case, we're read all the direct imports by now,
271 -- so eps_is_boot will record if any of our imports mention us by
272 -- way of hi-boot file
274 ; case lookupUFM (eps_is_boot eps) (moduleName mod) of {
275 Nothing -> return emptyModDetails ; -- The typical case
277 Just (_, False) -> failWithTc moduleLoop ;
278 -- Someone below us imported us!
279 -- This is a loop with no hi-boot in the way
281 Just (_mod, True) -> -- There's a hi-boot interface below us
283 do { read_result <- findAndReadIface
287 ; case read_result of
288 Failed err -> failWithTc (elaborate err)
289 Succeeded (iface, _path) -> typecheckIface iface
292 need = ptext (sLit "Need the hi-boot interface for") <+> ppr mod
293 <+> ptext (sLit "to compare against the Real Thing")
295 moduleLoop = ptext (sLit "Circular imports: module") <+> quotes (ppr mod)
296 <+> ptext (sLit "depends on itself")
298 elaborate err = hang (ptext (sLit "Could not find hi-boot interface for") <+>
299 quotes (ppr mod) <> colon) 4 err
303 %************************************************************************
305 Type and class declarations
307 %************************************************************************
309 When typechecking a data type decl, we *lazily* (via forkM) typecheck
310 the constructor argument types. This is in the hope that we may never
311 poke on those argument types, and hence may never need to load the
312 interface files for types mentioned in the arg types.
315 data Foo.S = MkS Baz.T
316 Mabye we can get away without even loading the interface for Baz!
318 This is not just a performance thing. Suppose we have
319 data Foo.S = MkS Baz.T
320 data Baz.T = MkT Foo.S
321 (in different interface files, of course).
322 Now, first we load and typecheck Foo.S, and add it to the type envt.
323 If we do explore MkS's argument, we'll load and typecheck Baz.T.
324 If we explore MkT's argument we'll find Foo.S already in the envt.
326 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
327 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
328 which isn't done yet.
330 All very cunning. However, there is a rather subtle gotcha which bit
331 me when developing this stuff. When we typecheck the decl for S, we
332 extend the type envt with S, MkS, and all its implicit Ids. Suppose
333 (a bug, but it happened) that the list of implicit Ids depended in
334 turn on the constructor arg types. Then the following sequence of
336 * we build a thunk <t> for the constructor arg tys
337 * we build a thunk for the extended type environment (depends on <t>)
338 * we write the extended type envt into the global EPS mutvar
340 Now we look something up in the type envt
342 * which reads the global type envt out of the global EPS mutvar
343 * but that depends in turn on <t>
345 It's subtle, because, it'd work fine if we typechecked the constructor args
346 eagerly -- they don't need the extended type envt. They just get the extended
347 type envt by accident, because they look at it later.
349 What this means is that the implicitTyThings MUST NOT DEPEND on any of
354 tcIfaceDecl :: Bool -- True <=> discard IdInfo on IfaceId bindings
358 tcIfaceDecl ignore_prags (IfaceId {ifName = occ_name, ifType = iface_type, ifIdInfo = info})
359 = do { name <- lookupIfaceTop occ_name
360 ; ty <- tcIfaceType iface_type
361 ; info <- tcIdInfo ignore_prags name ty info
362 ; return (AnId (mkVanillaGlobalWithInfo name ty info)) }
364 tcIfaceDecl _ (IfaceData {ifName = occ_name,
366 ifCtxt = ctxt, ifGadtSyntax = gadt_syn,
369 ifGeneric = want_generic,
370 ifFamInst = mb_family })
371 = do { tc_name <- lookupIfaceTop occ_name
372 ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
374 { tycon <- fixM ( \ tycon -> do
375 { stupid_theta <- tcIfaceCtxt ctxt
378 Nothing -> return Nothing
380 do { famTyCon <- tcIfaceTyCon fam
381 ; insttys <- mapM tcIfaceType tys
382 ; return $ Just (famTyCon, insttys)
384 ; cons <- tcIfaceDataCons tc_name tycon tyvars rdr_cons
385 ; buildAlgTyCon tc_name tyvars stupid_theta
386 cons is_rec want_generic gadt_syn famInst
388 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
389 ; return (ATyCon tycon)
392 tcIfaceDecl _ (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
393 ifSynRhs = mb_rhs_ty,
394 ifSynKind = kind, ifFamInst = mb_family})
395 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
396 { tc_name <- lookupIfaceTop occ_name
397 ; rhs_kind <- tcIfaceType kind -- Note [Synonym kind loop]
398 ; ~(rhs, fam) <- forkM (mk_doc tc_name) $
399 do { rhs <- tc_syn_rhs rhs_kind mb_rhs_ty
400 ; fam <- tc_syn_fam mb_family
401 ; return (rhs, fam) }
402 ; tycon <- buildSynTyCon tc_name tyvars rhs rhs_kind fam
403 ; return $ ATyCon tycon
406 mk_doc n = ptext (sLit "Type syonym") <+> ppr n
407 tc_syn_rhs kind Nothing = return (OpenSynTyCon kind Nothing)
408 tc_syn_rhs _ (Just ty) = do { rhs_ty <- tcIfaceType ty
409 ; return (SynonymTyCon rhs_ty) }
412 tc_syn_fam (Just (fam, tys))
413 = do { famTyCon <- tcIfaceTyCon fam
414 ; insttys <- mapM tcIfaceType tys
415 ; return $ Just (famTyCon, insttys) }
417 tcIfaceDecl ignore_prags
418 (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name,
419 ifTyVars = tv_bndrs, ifFDs = rdr_fds,
420 ifATs = rdr_ats, ifSigs = rdr_sigs,
422 -- ToDo: in hs-boot files we should really treat abstract classes specially,
423 -- as we do abstract tycons
424 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
425 { cls_name <- lookupIfaceTop occ_name
426 ; ctxt <- tcIfaceCtxt rdr_ctxt
427 ; sigs <- mapM tc_sig rdr_sigs
428 ; fds <- mapM tc_fd rdr_fds
429 ; ats' <- mapM (tcIfaceDecl ignore_prags) rdr_ats
430 ; let ats = zipWith setTyThingPoss ats' (map ifTyVars rdr_ats)
431 ; cls <- buildClass ignore_prags cls_name tyvars ctxt fds ats sigs tc_isrec
432 ; return (AClass cls) }
434 tc_sig (IfaceClassOp occ dm rdr_ty)
435 = do { op_name <- lookupIfaceTop occ
436 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
437 -- Must be done lazily for just the same reason as the
438 -- type of a data con; to avoid sucking in types that
439 -- it mentions unless it's necessray to do so
440 ; return (op_name, dm, op_ty) }
442 mk_doc op_name op_ty = ptext (sLit "Class op") <+> sep [ppr op_name, ppr op_ty]
444 tc_fd (tvs1, tvs2) = do { tvs1' <- mapM tcIfaceTyVar tvs1
445 ; tvs2' <- mapM tcIfaceTyVar tvs2
446 ; return (tvs1', tvs2') }
448 -- For each AT argument compute the position of the corresponding class
449 -- parameter in the class head. This will later serve as a permutation
450 -- vector when checking the validity of instance declarations.
451 setTyThingPoss (ATyCon tycon) atTyVars =
452 let classTyVars = map fst tv_bndrs
454 . map ((`elemIndex` classTyVars) . fst)
456 -- There will be no Nothing, as we already passed renaming
458 ATyCon (setTyConArgPoss tycon poss)
459 setTyThingPoss _ _ = panic "TcIface.setTyThingPoss"
461 tcIfaceDecl _ (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
462 = do { name <- lookupIfaceTop rdr_name
463 ; return (ATyCon (mkForeignTyCon name ext_name
466 tcIfaceDataCons :: Name -> TyCon -> [TyVar] -> IfaceConDecls -> IfL AlgTyConRhs
467 tcIfaceDataCons tycon_name tycon _ if_cons
469 IfAbstractTyCon -> return mkAbstractTyConRhs
470 IfOpenDataTyCon -> return mkOpenDataTyConRhs
471 IfDataTyCon cons -> do { data_cons <- mapM tc_con_decl cons
472 ; return (mkDataTyConRhs data_cons) }
473 IfNewTyCon con -> do { data_con <- tc_con_decl con
474 ; mkNewTyConRhs tycon_name tycon data_con }
476 tc_con_decl (IfCon { ifConInfix = is_infix,
477 ifConUnivTvs = univ_tvs, ifConExTvs = ex_tvs,
478 ifConOcc = occ, ifConCtxt = ctxt, ifConEqSpec = spec,
479 ifConArgTys = args, ifConFields = field_lbls,
480 ifConStricts = stricts})
481 = bindIfaceTyVars univ_tvs $ \ univ_tyvars -> do
482 bindIfaceTyVars ex_tvs $ \ ex_tyvars -> do
483 { name <- lookupIfaceTop occ
484 ; eq_spec <- tcIfaceEqSpec spec
485 ; theta <- tcIfaceCtxt ctxt -- Laziness seems not worth the bother here
486 -- At one stage I thought that this context checking *had*
487 -- to be lazy, because of possible mutual recursion between the
488 -- type and the classe:
490 -- class Real a where { toRat :: a -> Ratio Integer }
491 -- data (Real a) => Ratio a = ...
492 -- But now I think that the laziness in checking class ops breaks
493 -- the loop, so no laziness needed
495 -- Read the argument types, but lazily to avoid faulting in
496 -- the component types unless they are really needed
497 ; arg_tys <- forkM (mk_doc name) (mapM tcIfaceType args)
498 ; lbl_names <- mapM lookupIfaceTop field_lbls
500 -- Remember, tycon is the representation tycon
501 ; let orig_res_ty = mkFamilyTyConApp tycon
502 (substTyVars (mkTopTvSubst eq_spec) univ_tyvars)
504 ; buildDataCon name is_infix {- Not infix -}
506 univ_tyvars ex_tyvars
508 arg_tys orig_res_ty tycon
510 mk_doc con_name = ptext (sLit "Constructor") <+> ppr con_name
512 tcIfaceEqSpec :: [(OccName, IfaceType)] -> IfL [(TyVar, Type)]
516 do_item (occ, if_ty) = do { tv <- tcIfaceTyVar (occNameFS occ)
517 ; ty <- tcIfaceType if_ty
521 Note [Synonym kind loop]
522 ~~~~~~~~~~~~~~~~~~~~~~~~
523 Notice that we eagerly grab the *kind* from the interface file, but
524 build a forkM thunk for the *rhs* (and family stuff). To see why,
525 consider this (Trac #2412)
527 M.hs: module M where { import X; data T = MkT S }
528 X.hs: module X where { import {-# SOURCE #-} M; type S = T }
529 M.hs-boot: module M where { data T }
531 When kind-checking M.hs we need S's kind. But we do not want to
532 find S's kind from (typeKind S-rhs), because we don't want to look at
533 S-rhs yet! Since S is imported from X.hi, S gets just one chance to
534 be defined, and we must not do that until we've finished with M.T.
536 Solution: record S's kind in the interface file; now we can safely
539 %************************************************************************
543 %************************************************************************
546 tcIfaceInst :: IfaceInst -> IfL Instance
547 tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
548 ifInstCls = cls, ifInstTys = mb_tcs })
549 = do { dfun <- forkM (ptext (sLit "Dict fun") <+> ppr dfun_occ) $
550 tcIfaceExtId dfun_occ
551 ; let mb_tcs' = map (fmap ifaceTyConName) mb_tcs
552 ; return (mkImportedInstance cls mb_tcs' dfun oflag) }
554 tcIfaceFamInst :: IfaceFamInst -> IfL FamInst
555 tcIfaceFamInst (IfaceFamInst { ifFamInstTyCon = tycon,
556 ifFamInstFam = fam, ifFamInstTys = mb_tcs })
557 -- { tycon' <- forkM (ptext (sLit "Inst tycon") <+> ppr tycon) $
558 -- the above line doesn't work, but this below does => CPP in Haskell = evil!
559 = do tycon' <- forkM (text ("Inst tycon") <+> ppr tycon) $
561 let mb_tcs' = map (fmap ifaceTyConName) mb_tcs
562 return (mkImportedFamInst fam mb_tcs' tycon')
566 %************************************************************************
570 %************************************************************************
572 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
573 are in the type environment. However, remember that typechecking a Rule may
574 (as a side effect) augment the type envt, and so we may need to iterate the process.
577 tcIfaceRules :: Bool -- True <=> ignore rules
580 tcIfaceRules ignore_prags if_rules
581 | ignore_prags = return []
582 | otherwise = mapM tcIfaceRule if_rules
584 tcIfaceRule :: IfaceRule -> IfL CoreRule
585 tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,
586 ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs })
587 = do { ~(bndrs', args', rhs') <-
588 -- Typecheck the payload lazily, in the hope it'll never be looked at
589 forkM (ptext (sLit "Rule") <+> ftext name) $
590 bindIfaceBndrs bndrs $ \ bndrs' ->
591 do { args' <- mapM tcIfaceExpr args
592 ; rhs' <- tcIfaceExpr rhs
593 ; return (bndrs', args', rhs') }
594 ; let mb_tcs = map ifTopFreeName args
595 ; return (Rule { ru_name = name, ru_fn = fn, ru_act = act,
596 ru_bndrs = bndrs', ru_args = args',
599 ru_local = False }) } -- An imported RULE is never for a local Id
600 -- or, even if it is (module loop, perhaps)
601 -- we'll just leave it in the non-local set
603 -- This function *must* mirror exactly what Rules.topFreeName does
604 -- We could have stored the ru_rough field in the iface file
605 -- but that would be redundant, I think.
606 -- The only wrinkle is that we must not be deceived by
607 -- type syononyms at the top of a type arg. Since
608 -- we can't tell at this point, we are careful not
609 -- to write them out in coreRuleToIfaceRule
610 ifTopFreeName :: IfaceExpr -> Maybe Name
611 ifTopFreeName (IfaceType (IfaceTyConApp tc _ )) = Just (ifaceTyConName tc)
612 ifTopFreeName (IfaceApp f _) = ifTopFreeName f
613 ifTopFreeName (IfaceExt n) = Just n
614 ifTopFreeName _ = Nothing
618 %************************************************************************
622 %************************************************************************
625 tcIfaceAnnotations :: [IfaceAnnotation] -> IfL [Annotation]
626 tcIfaceAnnotations = mapM tcIfaceAnnotation
628 tcIfaceAnnotation :: IfaceAnnotation -> IfL Annotation
629 tcIfaceAnnotation (IfaceAnnotation target serialized) = do
630 target' <- tcIfaceAnnTarget target
631 return $ Annotation {
632 ann_target = target',
633 ann_value = serialized
636 tcIfaceAnnTarget :: IfaceAnnTarget -> IfL (AnnTarget Name)
637 tcIfaceAnnTarget (NamedTarget occ) = do
638 name <- lookupIfaceTop occ
639 return $ NamedTarget name
640 tcIfaceAnnTarget (ModuleTarget mod) = do
641 return $ ModuleTarget mod
646 %************************************************************************
648 Vectorisation information
650 %************************************************************************
653 tcIfaceVectInfo :: Module -> TypeEnv -> IfaceVectInfo -> IfL VectInfo
654 tcIfaceVectInfo mod typeEnv (IfaceVectInfo
655 { ifaceVectInfoVar = vars
656 , ifaceVectInfoTyCon = tycons
657 , ifaceVectInfoTyConReuse = tyconsReuse
659 = do { vVars <- mapM vectVarMapping vars
660 ; tyConRes1 <- mapM vectTyConMapping tycons
661 ; tyConRes2 <- mapM vectTyConReuseMapping tyconsReuse
662 ; let (vTyCons, vDataCons, vPAs, vIsos) = unzip4 (tyConRes1 ++ tyConRes2)
664 { vectInfoVar = mkVarEnv vVars
665 , vectInfoTyCon = mkNameEnv vTyCons
666 , vectInfoDataCon = mkNameEnv (concat vDataCons)
667 , vectInfoPADFun = mkNameEnv vPAs
668 , vectInfoIso = mkNameEnv vIsos
673 = do { vName <- lookupOrig mod (mkVectOcc (nameOccName name))
674 ; let { var = lookupVar name
675 ; vVar = lookupVar vName
677 ; return (var, (var, vVar))
679 vectTyConMapping name
680 = do { vName <- lookupOrig mod (mkVectTyConOcc (nameOccName name))
681 ; paName <- lookupOrig mod (mkPADFunOcc (nameOccName name))
682 ; isoName <- lookupOrig mod (mkVectIsoOcc (nameOccName name))
683 ; let { tycon = lookupTyCon name
684 ; vTycon = lookupTyCon vName
685 ; paTycon = lookupVar paName
686 ; isoTycon = lookupVar isoName
688 ; vDataCons <- mapM vectDataConMapping (tyConDataCons tycon)
689 ; return ((name, (tycon, vTycon)), -- (T, T_v)
690 vDataCons, -- list of (Ci, Ci_v)
691 (vName, (vTycon, paTycon)), -- (T_v, paT)
692 (name, (tycon, isoTycon))) -- (T, isoT)
694 vectTyConReuseMapping name
695 = do { paName <- lookupOrig mod (mkPADFunOcc (nameOccName name))
696 ; isoName <- lookupOrig mod (mkVectIsoOcc (nameOccName name))
697 ; let { tycon = lookupTyCon name
698 ; paTycon = lookupVar paName
699 ; isoTycon = lookupVar isoName
700 ; vDataCons = [ (dataConName dc, (dc, dc))
701 | dc <- tyConDataCons tycon]
703 ; return ((name, (tycon, tycon)), -- (T, T)
704 vDataCons, -- list of (Ci, Ci)
705 (name, (tycon, paTycon)), -- (T, paT)
706 (name, (tycon, isoTycon))) -- (T, isoT)
708 vectDataConMapping datacon
709 = do { let name = dataConName datacon
710 ; vName <- lookupOrig mod (mkVectDataConOcc (nameOccName name))
711 ; let vDataCon = lookupDataCon vName
712 ; return (name, (datacon, vDataCon))
715 lookupVar name = case lookupTypeEnv typeEnv name of
716 Just (AnId var) -> var
718 panic "TcIface.tcIfaceVectInfo: not an id"
720 panic "TcIface.tcIfaceVectInfo: unknown name"
721 lookupTyCon name = case lookupTypeEnv typeEnv name of
722 Just (ATyCon tc) -> tc
724 panic "TcIface.tcIfaceVectInfo: not a tycon"
726 panic "TcIface.tcIfaceVectInfo: unknown name"
727 lookupDataCon name = case lookupTypeEnv typeEnv name of
728 Just (ADataCon dc) -> dc
730 panic "TcIface.tcIfaceVectInfo: not a datacon"
732 panic "TcIface.tcIfaceVectInfo: unknown name"
735 %************************************************************************
739 %************************************************************************
742 tcIfaceType :: IfaceType -> IfL Type
743 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
744 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
745 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
746 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkTyConApp tc' ts') }
747 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
748 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
750 tcIfaceTypes :: [IfaceType] -> IfL [Type]
751 tcIfaceTypes tys = mapM tcIfaceType tys
753 -----------------------------------------
754 tcIfacePredType :: IfacePredType -> IfL PredType
755 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
756 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
757 tcIfacePredType (IfaceEqPred t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (EqPred t1' t2') }
759 -----------------------------------------
760 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
761 tcIfaceCtxt sts = mapM tcIfacePredType sts
765 %************************************************************************
769 %************************************************************************
772 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
773 tcIfaceExpr (IfaceType ty)
774 = Type <$> tcIfaceType ty
776 tcIfaceExpr (IfaceLcl name)
777 = Var <$> tcIfaceLclId name
779 tcIfaceExpr (IfaceTick modName tickNo)
780 = Var <$> tcIfaceTick modName tickNo
782 tcIfaceExpr (IfaceExt gbl)
783 = Var <$> tcIfaceExtId gbl
785 tcIfaceExpr (IfaceLit lit)
788 tcIfaceExpr (IfaceFCall cc ty) = do
789 ty' <- tcIfaceType ty
791 return (Var (mkFCallId u cc ty'))
793 tcIfaceExpr (IfaceTuple boxity args) = do
794 args' <- mapM tcIfaceExpr args
795 -- Put the missing type arguments back in
796 let con_args = map (Type . exprType) args' ++ args'
797 return (mkApps (Var con_id) con_args)
800 con_id = dataConWorkId (tupleCon boxity arity)
803 tcIfaceExpr (IfaceLam bndr body)
804 = bindIfaceBndr bndr $ \bndr' ->
805 Lam bndr' <$> tcIfaceExpr body
807 tcIfaceExpr (IfaceApp fun arg)
808 = App <$> tcIfaceExpr fun <*> tcIfaceExpr arg
810 tcIfaceExpr (IfaceCase scrut case_bndr ty alts) = do
811 scrut' <- tcIfaceExpr scrut
812 case_bndr_name <- newIfaceName (mkVarOccFS case_bndr)
814 scrut_ty = exprType scrut'
815 case_bndr' = mkLocalId case_bndr_name scrut_ty
816 tc_app = splitTyConApp scrut_ty
817 -- NB: Won't always succeed (polymoprhic case)
818 -- but won't be demanded in those cases
819 -- NB: not tcSplitTyConApp; we are looking at Core here
820 -- look through non-rec newtypes to find the tycon that
821 -- corresponds to the datacon in this case alternative
823 extendIfaceIdEnv [case_bndr'] $ do
824 alts' <- mapM (tcIfaceAlt scrut' tc_app) alts
825 ty' <- tcIfaceType ty
826 return (Case scrut' case_bndr' ty' alts')
828 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body) = do
829 rhs' <- tcIfaceExpr rhs
830 id <- tcIfaceLetBndr bndr
831 body' <- extendIfaceIdEnv [id] (tcIfaceExpr body)
832 return (Let (NonRec id rhs') body')
834 tcIfaceExpr (IfaceLet (IfaceRec pairs) body) = do
835 ids <- mapM tcIfaceLetBndr bndrs
836 extendIfaceIdEnv ids $ do
837 rhss' <- mapM tcIfaceExpr rhss
838 body' <- tcIfaceExpr body
839 return (Let (Rec (ids `zip` rhss')) body')
841 (bndrs, rhss) = unzip pairs
843 tcIfaceExpr (IfaceCast expr co) = do
844 expr' <- tcIfaceExpr expr
845 co' <- tcIfaceType co
846 return (Cast expr' co')
848 tcIfaceExpr (IfaceNote note expr) = do
849 expr' <- tcIfaceExpr expr
851 IfaceInlineMe -> return (Note InlineMe expr')
852 IfaceSCC cc -> return (Note (SCC cc) expr')
853 IfaceCoreNote n -> return (Note (CoreNote n) expr')
855 -------------------------
856 tcIfaceAlt :: CoreExpr -> (TyCon, [Type])
857 -> (IfaceConAlt, [FastString], IfaceExpr)
858 -> IfL (AltCon, [TyVar], CoreExpr)
859 tcIfaceAlt _ _ (IfaceDefault, names, rhs)
860 = ASSERT( null names ) do
861 rhs' <- tcIfaceExpr rhs
862 return (DEFAULT, [], rhs')
864 tcIfaceAlt _ _ (IfaceLitAlt lit, names, rhs)
865 = ASSERT( null names ) do
866 rhs' <- tcIfaceExpr rhs
867 return (LitAlt lit, [], rhs')
869 -- A case alternative is made quite a bit more complicated
870 -- by the fact that we omit type annotations because we can
871 -- work them out. True enough, but its not that easy!
872 tcIfaceAlt scrut (tycon, inst_tys) (IfaceDataAlt data_occ, arg_strs, rhs)
873 = do { con <- tcIfaceDataCon data_occ
874 ; when (debugIsOn && not (con `elem` tyConDataCons tycon))
875 (failIfM (ppr scrut $$ ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon)))
876 ; tcIfaceDataAlt con inst_tys arg_strs rhs }
878 tcIfaceAlt _ (tycon, inst_tys) (IfaceTupleAlt _boxity, arg_occs, rhs)
879 = ASSERT( isTupleTyCon tycon )
880 do { let [data_con] = tyConDataCons tycon
881 ; tcIfaceDataAlt data_con inst_tys arg_occs rhs }
883 tcIfaceDataAlt :: DataCon -> [Type] -> [FastString] -> IfaceExpr
884 -> IfL (AltCon, [TyVar], CoreExpr)
885 tcIfaceDataAlt con inst_tys arg_strs rhs
886 = do { us <- newUniqueSupply
887 ; let uniqs = uniqsFromSupply us
888 ; let (ex_tvs, co_tvs, arg_ids)
889 = dataConRepFSInstPat arg_strs uniqs con inst_tys
890 all_tvs = ex_tvs ++ co_tvs
892 ; rhs' <- extendIfaceTyVarEnv all_tvs $
893 extendIfaceIdEnv arg_ids $
895 ; return (DataAlt con, all_tvs ++ arg_ids, rhs') }
900 tcExtCoreBindings :: [IfaceBinding] -> IfL [CoreBind] -- Used for external core
901 tcExtCoreBindings [] = return []
902 tcExtCoreBindings (b:bs) = do_one b (tcExtCoreBindings bs)
904 do_one :: IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
905 do_one (IfaceNonRec bndr rhs) thing_inside
906 = do { rhs' <- tcIfaceExpr rhs
907 ; bndr' <- newExtCoreBndr bndr
908 ; extendIfaceIdEnv [bndr'] $ do
909 { core_binds <- thing_inside
910 ; return (NonRec bndr' rhs' : core_binds) }}
912 do_one (IfaceRec pairs) thing_inside
913 = do { bndrs' <- mapM newExtCoreBndr bndrs
914 ; extendIfaceIdEnv bndrs' $ do
915 { rhss' <- mapM tcIfaceExpr rhss
916 ; core_binds <- thing_inside
917 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
919 (bndrs,rhss) = unzip pairs
923 %************************************************************************
927 %************************************************************************
930 tcIdInfo :: Bool -> Name -> Type -> IfaceIdInfo -> IfL IdInfo
931 tcIdInfo ignore_prags name ty info
932 | ignore_prags = return vanillaIdInfo
933 | otherwise = case info of
934 NoInfo -> return vanillaIdInfo
935 HasInfo info -> foldlM tcPrag init_info info
937 -- Set the CgInfo to something sensible but uninformative before
938 -- we start; default assumption is that it has CAFs
939 init_info = vanillaIdInfo
941 tcPrag :: IdInfo -> IfaceInfoItem -> IfL IdInfo
942 tcPrag info HsNoCafRefs = return (info `setCafInfo` NoCafRefs)
943 tcPrag info (HsArity arity) = return (info `setArityInfo` arity)
944 tcPrag info (HsStrictness str) = return (info `setAllStrictnessInfo` Just str)
946 -- The next two are lazy, so they don't transitively suck stuff in
947 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
948 tcPrag info (HsInline inline_prag) = return (info `setInlinePragInfo` inline_prag)
949 tcPrag info (HsUnfold expr) = do
950 maybe_expr' <- tcPragExpr name expr
952 -- maybe_expr' doesn't get looked at if the unfolding
953 -- is never inspected; so the typecheck doesn't even happen
954 unfold_info = case maybe_expr' of
955 Nothing -> noUnfolding
956 Just expr' -> mkTopUnfolding expr'
957 return (info `setUnfoldingInfoLazily` unfold_info)
961 tcWorkerInfo :: Type -> IdInfo -> Name -> Arity -> IfL IdInfo
962 tcWorkerInfo ty info wkr arity
963 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId wkr)
965 -- We return without testing maybe_wkr_id, but as soon as info is
966 -- looked at we will test it. That's ok, because its outside the
967 -- knot; and there seems no big reason to further defer the
968 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
969 -- over the unfolding until it's actually used does seem worth while.)
970 ; us <- newUniqueSupply
972 ; return (case mb_wkr_id of
974 Just wkr_id -> add_wkr_info us wkr_id info) }
976 doc = text "Worker for" <+> ppr wkr
977 add_wkr_info us wkr_id info
978 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
979 `setWorkerInfo` HasWorker wkr_id arity
981 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
983 -- We are relying here on strictness info always appearing
984 -- before worker info, fingers crossed ....
985 strict_sig = case newStrictnessInfo info of
987 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr)
990 For unfoldings we try to do the job lazily, so that we never type check
991 an unfolding that isn't going to be looked at.
994 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
996 = forkM_maybe doc $ do
997 core_expr' <- tcIfaceExpr expr
999 -- Check for type consistency in the unfolding
1000 ifOptM Opt_DoCoreLinting $ do
1001 in_scope <- get_in_scope_ids
1002 case lintUnfolding noSrcLoc in_scope core_expr' of
1003 Nothing -> return ()
1004 Just fail_msg -> pprPanic "Iface Lint failure" (hang doc 2 fail_msg)
1008 doc = text "Unfolding of" <+> ppr name
1009 get_in_scope_ids -- Urgh; but just for linting
1011 do { env <- getGblEnv
1012 ; case if_rec_types env of {
1013 Nothing -> return [] ;
1014 Just (_, get_env) -> do
1015 { type_env <- get_env
1016 ; return (typeEnvIds type_env) }}}
1021 %************************************************************************
1023 Getting from Names to TyThings
1025 %************************************************************************
1028 tcIfaceGlobal :: Name -> IfL TyThing
1030 | Just thing <- wiredInNameTyThing_maybe name
1031 -- Wired-in things include TyCons, DataCons, and Ids
1032 = do { ifCheckWiredInThing name; return thing }
1034 = do { env <- getGblEnv
1035 ; case if_rec_types env of { -- Note [Tying the knot]
1036 Just (mod, get_type_env)
1037 | nameIsLocalOrFrom mod name
1038 -> do -- It's defined in the module being compiled
1039 { type_env <- setLclEnv () get_type_env -- yuk
1040 ; case lookupNameEnv type_env name of
1041 Just thing -> return thing
1042 Nothing -> pprPanic "tcIfaceGlobal (local): not found:"
1043 (ppr name $$ ppr type_env) }
1047 { hsc_env <- getTopEnv
1048 ; mb_thing <- liftIO (lookupTypeHscEnv hsc_env name)
1049 ; case mb_thing of {
1050 Just thing -> return thing ;
1053 { mb_thing <- importDecl name -- It's imported; go get it
1055 Failed err -> failIfM err
1056 Succeeded thing -> return thing
1059 -- Note [Tying the knot]
1060 -- ~~~~~~~~~~~~~~~~~~~~~
1061 -- The if_rec_types field is used in two situations:
1063 -- a) Compiling M.hs, which indiretly imports Foo.hi, which mentions M.T
1064 -- Then we look up M.T in M's type environment, which is splatted into if_rec_types
1065 -- after we've built M's type envt.
1067 -- b) In ghc --make, during the upsweep, we encounter M.hs, whose interface M.hi
1068 -- is up to date. So we call typecheckIface on M.hi. This splats M.T into
1069 -- if_rec_types so that the (lazily typechecked) decls see all the other decls
1071 -- In case (b) it's important to do the if_rec_types check *before* looking in the HPT
1072 -- Because if M.hs also has M.hs-boot, M.T will *already be* in the HPT, but in its
1073 -- emasculated form (e.g. lacking data constructors).
1075 ifCheckWiredInThing :: Name -> IfL ()
1076 -- Even though we are in an interface file, we want to make
1077 -- sure the instances of a wired-in thing are loaded (imagine f :: Double -> Double)
1078 -- Ditto want to ensure that RULES are loaded too
1079 -- See Note [Loading instances] in LoadIface
1080 ifCheckWiredInThing name
1081 = do { mod <- getIfModule
1082 -- Check whether we are typechecking the interface for this
1083 -- very module. E.g when compiling the base library in --make mode
1084 -- we may typecheck GHC.Base.hi. At that point, GHC.Base is not in
1085 -- the HPT, so without the test we'll demand-load it into the PIT!
1086 -- C.f. the same test in checkWiredInTyCon above
1087 ; ASSERT2( isExternalName name, ppr name )
1088 unless (mod == nameModule name)
1089 (loadWiredInHomeIface name) }
1091 tcIfaceTyCon :: IfaceTyCon -> IfL TyCon
1092 tcIfaceTyCon IfaceIntTc = tcWiredInTyCon intTyCon
1093 tcIfaceTyCon IfaceBoolTc = tcWiredInTyCon boolTyCon
1094 tcIfaceTyCon IfaceCharTc = tcWiredInTyCon charTyCon
1095 tcIfaceTyCon IfaceListTc = tcWiredInTyCon listTyCon
1096 tcIfaceTyCon IfacePArrTc = tcWiredInTyCon parrTyCon
1097 tcIfaceTyCon (IfaceTupTc bx ar) = tcWiredInTyCon (tupleTyCon bx ar)
1098 tcIfaceTyCon (IfaceTc name) = do { thing <- tcIfaceGlobal name
1099 ; return (check_tc (tyThingTyCon thing)) }
1102 | debugIsOn = case toIfaceTyCon tc of
1104 _ -> pprTrace "check_tc" (ppr tc) tc
1106 -- we should be okay just returning Kind constructors without extra loading
1107 tcIfaceTyCon IfaceLiftedTypeKindTc = return liftedTypeKindTyCon
1108 tcIfaceTyCon IfaceOpenTypeKindTc = return openTypeKindTyCon
1109 tcIfaceTyCon IfaceUnliftedTypeKindTc = return unliftedTypeKindTyCon
1110 tcIfaceTyCon IfaceArgTypeKindTc = return argTypeKindTyCon
1111 tcIfaceTyCon IfaceUbxTupleKindTc = return ubxTupleKindTyCon
1113 -- Even though we are in an interface file, we want to make
1114 -- sure the instances and RULES of this tycon are loaded
1115 -- Imagine: f :: Double -> Double
1116 tcWiredInTyCon :: TyCon -> IfL TyCon
1117 tcWiredInTyCon tc = do { ifCheckWiredInThing (tyConName tc)
1120 tcIfaceClass :: Name -> IfL Class
1121 tcIfaceClass name = do { thing <- tcIfaceGlobal name
1122 ; return (tyThingClass thing) }
1124 tcIfaceDataCon :: Name -> IfL DataCon
1125 tcIfaceDataCon name = do { thing <- tcIfaceGlobal name
1127 ADataCon dc -> return dc
1128 _ -> pprPanic "tcIfaceExtDC" (ppr name$$ ppr thing) }
1130 tcIfaceExtId :: Name -> IfL Id
1131 tcIfaceExtId name = do { thing <- tcIfaceGlobal name
1133 AnId id -> return id
1134 _ -> pprPanic "tcIfaceExtId" (ppr name$$ ppr thing) }
1137 %************************************************************************
1141 %************************************************************************
1144 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
1145 bindIfaceBndr (IfaceIdBndr (fs, ty)) thing_inside
1146 = do { name <- newIfaceName (mkVarOccFS fs)
1147 ; ty' <- tcIfaceType ty
1148 ; let id = mkLocalId name ty'
1149 ; extendIfaceIdEnv [id] (thing_inside id) }
1150 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
1151 = bindIfaceTyVar bndr thing_inside
1153 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
1154 bindIfaceBndrs [] thing_inside = thing_inside []
1155 bindIfaceBndrs (b:bs) thing_inside
1156 = bindIfaceBndr b $ \ b' ->
1157 bindIfaceBndrs bs $ \ bs' ->
1158 thing_inside (b':bs')
1160 -----------------------
1161 tcIfaceLetBndr :: IfaceLetBndr -> IfL Id
1162 tcIfaceLetBndr (IfLetBndr fs ty info)
1163 = do { name <- newIfaceName (mkVarOccFS fs)
1164 ; ty' <- tcIfaceType ty
1166 NoInfo -> return (mkLocalId name ty')
1167 HasInfo i -> return (mkLocalIdWithInfo name ty' (tc_info i)) }
1169 -- Similar to tcIdInfo, but much simpler
1170 tc_info [] = vanillaIdInfo
1171 tc_info (HsInline p : i) = tc_info i `setInlinePragInfo` p
1172 tc_info (HsArity a : i) = tc_info i `setArityInfo` a
1173 tc_info (HsStrictness s : i) = tc_info i `setAllStrictnessInfo` Just s
1174 tc_info (other : i) = pprTrace "tcIfaceLetBndr: discarding unexpected IdInfo"
1175 (ppr other) (tc_info i)
1177 -----------------------
1178 newExtCoreBndr :: IfaceLetBndr -> IfL Id
1179 newExtCoreBndr (IfLetBndr var ty _) -- Ignoring IdInfo for now
1180 = do { mod <- getIfModule
1181 ; name <- newGlobalBinder mod (mkVarOccFS var) noSrcSpan
1182 ; ty' <- tcIfaceType ty
1183 ; return (mkLocalId name ty') }
1185 -----------------------
1186 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
1187 bindIfaceTyVar (occ,kind) thing_inside
1188 = do { name <- newIfaceName (mkTyVarOccFS occ)
1189 ; tyvar <- mk_iface_tyvar name kind
1190 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
1192 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
1193 bindIfaceTyVars bndrs thing_inside
1194 = do { names <- newIfaceNames (map mkTyVarOccFS occs)
1195 ; tyvars <- zipWithM mk_iface_tyvar names kinds
1196 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
1198 (occs,kinds) = unzip bndrs
1200 mk_iface_tyvar :: Name -> IfaceKind -> IfL TyVar
1201 mk_iface_tyvar name ifKind
1202 = do { kind <- tcIfaceType ifKind
1203 ; if isCoercionKind kind then
1204 return (Var.mkCoVar name kind)
1206 return (Var.mkTyVar name kind) }