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, tcIfaceGlobal,
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)
203 ; exports <- ifaceExportNames (mi_exports iface)
206 ; traceIf (vcat [text "Finished typechecking interface for" <+> ppr (mi_module iface),
207 text "Type envt:" <+> ppr type_env])
208 ; return $ ModDetails { md_types = type_env
210 , md_fam_insts = fam_insts
212 , md_exports = exports
218 %************************************************************************
220 Type and class declarations
222 %************************************************************************
225 tcHiBootIface :: Module -> TcRn ModDetails
226 -- Load the hi-boot iface for the module being compiled,
227 -- if it indeed exists in the transitive closure of imports
228 -- Return the ModDetails, empty if no hi-boot iface
230 = do { traceIf (text "loadHiBootInterface" <+> ppr mod)
233 ; if not (isOneShot mode)
234 -- In --make and interactive mode, if this module has an hs-boot file
235 -- we'll have compiled it already, and it'll be in the HPT
237 -- We check wheher the interface is a *boot* interface.
238 -- It can happen (when using GHC from Visual Studio) that we
239 -- compile a module in TypecheckOnly mode, with a stable,
240 -- fully-populated HPT. In that case the boot interface isn't there
241 -- (it's been replaced by the mother module) so we can't check it.
242 -- And that's fine, because if M's ModInfo is in the HPT, then
243 -- it's been compiled once, and we don't need to check the boot iface
244 then do { hpt <- getHpt
245 ; case lookupUFM hpt (moduleName mod) of
246 Just info | mi_boot (hm_iface info)
247 -> return (hm_details info)
248 other -> return emptyModDetails }
251 -- OK, so we're in one-shot mode.
252 -- In that case, we're read all the direct imports by now,
253 -- so eps_is_boot will record if any of our imports mention us by
254 -- way of hi-boot file
256 ; case lookupUFM (eps_is_boot eps) (moduleName mod) of {
257 Nothing -> return emptyModDetails ; -- The typical case
259 Just (_, False) -> failWithTc moduleLoop ;
260 -- Someone below us imported us!
261 -- This is a loop with no hi-boot in the way
263 Just (_mod, True) -> -- There's a hi-boot interface below us
265 do { read_result <- findAndReadIface
269 ; case read_result of
270 Failed err -> failWithTc (elaborate err)
271 Succeeded (iface, _path) -> typecheckIface iface
274 need = ptext SLIT("Need the hi-boot interface for") <+> ppr mod
275 <+> ptext SLIT("to compare against the Real Thing")
277 moduleLoop = ptext SLIT("Circular imports: module") <+> quotes (ppr mod)
278 <+> ptext SLIT("depends on itself")
280 elaborate err = hang (ptext SLIT("Could not find hi-boot interface for") <+>
281 quotes (ppr mod) <> colon) 4 err
285 %************************************************************************
287 Type and class declarations
289 %************************************************************************
291 When typechecking a data type decl, we *lazily* (via forkM) typecheck
292 the constructor argument types. This is in the hope that we may never
293 poke on those argument types, and hence may never need to load the
294 interface files for types mentioned in the arg types.
297 data Foo.S = MkS Baz.T
298 Mabye we can get away without even loading the interface for Baz!
300 This is not just a performance thing. Suppose we have
301 data Foo.S = MkS Baz.T
302 data Baz.T = MkT Foo.S
303 (in different interface files, of course).
304 Now, first we load and typecheck Foo.S, and add it to the type envt.
305 If we do explore MkS's argument, we'll load and typecheck Baz.T.
306 If we explore MkT's argument we'll find Foo.S already in the envt.
308 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
309 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
310 which isn't done yet.
312 All very cunning. However, there is a rather subtle gotcha which bit
313 me when developing this stuff. When we typecheck the decl for S, we
314 extend the type envt with S, MkS, and all its implicit Ids. Suppose
315 (a bug, but it happened) that the list of implicit Ids depended in
316 turn on the constructor arg types. Then the following sequence of
318 * we build a thunk <t> for the constructor arg tys
319 * we build a thunk for the extended type environment (depends on <t>)
320 * we write the extended type envt into the global EPS mutvar
322 Now we look something up in the type envt
324 * which reads the global type envt out of the global EPS mutvar
325 * but that depends in turn on <t>
327 It's subtle, because, it'd work fine if we typechecked the constructor args
328 eagerly -- they don't need the extended type envt. They just get the extended
329 type envt by accident, because they look at it later.
331 What this means is that the implicitTyThings MUST NOT DEPEND on any of
336 tcIfaceDecl :: Bool -- True <=> discard IdInfo on IfaceId bindings
340 tcIfaceDecl ignore_prags (IfaceId {ifName = occ_name, ifType = iface_type, ifIdInfo = info})
341 = do { name <- lookupIfaceTop occ_name
342 ; ty <- tcIfaceType iface_type
343 ; info <- tcIdInfo ignore_prags name ty info
344 ; return (AnId (mkVanillaGlobal name ty info)) }
346 tcIfaceDecl ignore_prags
347 (IfaceData {ifName = occ_name,
349 ifCtxt = ctxt, ifGadtSyntax = gadt_syn,
352 ifGeneric = want_generic,
353 ifFamInst = mb_family })
354 = do { tc_name <- lookupIfaceTop occ_name
355 ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
357 { tycon <- fixM ( \ tycon -> do
358 { stupid_theta <- tcIfaceCtxt ctxt
361 Nothing -> return Nothing
363 do { famTyCon <- tcIfaceTyCon fam
364 ; insttys <- mapM tcIfaceType tys
365 ; return $ Just (famTyCon, insttys)
367 ; cons <- tcIfaceDataCons tc_name tycon tyvars rdr_cons
368 ; buildAlgTyCon tc_name tyvars stupid_theta
369 cons is_rec want_generic gadt_syn famInst
371 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
372 ; return (ATyCon tycon)
375 tcIfaceDecl ignore_prags
376 (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
377 ifOpenSyn = isOpen, ifSynRhs = rdr_rhs_ty})
378 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
379 { tc_name <- lookupIfaceTop occ_name
380 ; rhs_tyki <- tcIfaceType rdr_rhs_ty
381 ; let rhs = if isOpen then OpenSynTyCon rhs_tyki
382 else SynonymTyCon rhs_tyki
383 ; return (ATyCon (buildSynTyCon tc_name tyvars rhs))
386 tcIfaceDecl ignore_prags
387 (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name,
388 ifTyVars = tv_bndrs, ifFDs = rdr_fds,
389 ifATs = rdr_ats, ifSigs = rdr_sigs,
391 -- ToDo: in hs-boot files we should really treat abstract classes specially,
392 -- as we do abstract tycons
393 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
394 { cls_name <- lookupIfaceTop occ_name
395 ; ctxt <- tcIfaceCtxt rdr_ctxt
396 ; sigs <- mappM tc_sig rdr_sigs
397 ; fds <- mappM tc_fd rdr_fds
398 ; ats' <- mappM (tcIfaceDecl ignore_prags) rdr_ats
399 ; let ats = zipWith setTyThingPoss ats' (map ifTyVars rdr_ats)
400 ; cls <- buildClass cls_name tyvars ctxt fds ats sigs tc_isrec
401 ; return (AClass cls) }
403 tc_sig (IfaceClassOp occ dm rdr_ty)
404 = do { op_name <- lookupIfaceTop occ
405 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
406 -- Must be done lazily for just the same reason as the
407 -- context of a data decl: the type sig might mention the
408 -- class being defined
409 ; return (op_name, dm, op_ty) }
411 mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
413 tc_fd (tvs1, tvs2) = do { tvs1' <- mappM tcIfaceTyVar tvs1
414 ; tvs2' <- mappM tcIfaceTyVar tvs2
415 ; return (tvs1', tvs2') }
417 -- For each AT argument compute the position of the corresponding class
418 -- parameter in the class head. This will later serve as a permutation
419 -- vector when checking the validity of instance declarations.
420 setTyThingPoss (ATyCon tycon) atTyVars =
421 let classTyVars = map fst tv_bndrs
423 . map ((`elemIndex` classTyVars) . fst)
425 -- There will be no Nothing, as we already passed renaming
427 ATyCon (setTyConArgPoss tycon poss)
428 setTyThingPoss _ _ = panic "TcIface.setTyThingPoss"
430 tcIfaceDecl ignore_prags (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
431 = do { name <- lookupIfaceTop rdr_name
432 ; return (ATyCon (mkForeignTyCon name ext_name
435 tcIfaceDataCons tycon_name tycon tc_tyvars if_cons
437 IfAbstractTyCon -> return mkAbstractTyConRhs
438 IfOpenDataTyCon -> return mkOpenDataTyConRhs
439 IfOpenNewTyCon -> return mkOpenNewTyConRhs
440 IfDataTyCon cons -> do { data_cons <- mappM tc_con_decl cons
441 ; return (mkDataTyConRhs data_cons) }
442 IfNewTyCon con -> do { data_con <- tc_con_decl con
443 ; mkNewTyConRhs tycon_name tycon data_con }
445 tc_con_decl (IfCon { ifConInfix = is_infix,
446 ifConUnivTvs = univ_tvs, ifConExTvs = ex_tvs,
447 ifConOcc = occ, ifConCtxt = ctxt, ifConEqSpec = spec,
448 ifConArgTys = args, ifConFields = field_lbls,
449 ifConStricts = stricts})
450 = bindIfaceTyVars univ_tvs $ \ univ_tyvars -> do
451 bindIfaceTyVars ex_tvs $ \ ex_tyvars -> do
452 { name <- lookupIfaceTop occ
453 ; eq_spec <- tcIfaceEqSpec spec
454 ; theta <- tcIfaceCtxt ctxt -- Laziness seems not worth the bother here
455 -- At one stage I thought that this context checking *had*
456 -- to be lazy, because of possible mutual recursion between the
457 -- type and the classe:
459 -- class Real a where { toRat :: a -> Ratio Integer }
460 -- data (Real a) => Ratio a = ...
461 -- But now I think that the laziness in checking class ops breaks
462 -- the loop, so no laziness needed
464 -- Read the argument types, but lazily to avoid faulting in
465 -- the component types unless they are really needed
466 ; arg_tys <- forkM (mk_doc name) (mappM tcIfaceType args)
467 ; lbl_names <- mappM lookupIfaceTop field_lbls
469 ; buildDataCon name is_infix {- Not infix -}
471 univ_tyvars ex_tyvars
475 mk_doc con_name = ptext SLIT("Constructor") <+> ppr con_name
480 do_item (occ, if_ty) = do { tv <- tcIfaceTyVar (occNameFS occ)
481 ; ty <- tcIfaceType if_ty
486 %************************************************************************
490 %************************************************************************
493 tcIfaceInst :: IfaceInst -> IfL Instance
494 tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
495 ifInstCls = cls, ifInstTys = mb_tcs,
497 = do { dfun <- forkM (ptext SLIT("Dict fun") <+> ppr dfun_occ) $
498 tcIfaceExtId dfun_occ
499 ; let mb_tcs' = map (fmap ifaceTyConName) mb_tcs
500 ; return (mkImportedInstance cls mb_tcs' orph dfun oflag) }
502 tcIfaceFamInst :: IfaceFamInst -> IfL FamInst
503 tcIfaceFamInst (IfaceFamInst { ifFamInstTyCon = tycon,
504 ifFamInstFam = fam, ifFamInstTys = mb_tcs })
505 -- = do { tycon' <- forkM (ptext SLIT("Inst tycon") <+> ppr tycon) $
506 -- ^^^this line doesn't work, but vvv this does => CPP in Haskell = evil!
507 = do { tycon' <- forkM (text ("Inst tycon") <+> ppr tycon) $
509 ; let mb_tcs' = map (fmap ifaceTyConName) mb_tcs
510 ; return (mkImportedFamInst fam mb_tcs' tycon') }
514 %************************************************************************
518 %************************************************************************
520 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
521 are in the type environment. However, remember that typechecking a Rule may
522 (as a side effect) augment the type envt, and so we may need to iterate the process.
525 tcIfaceRules :: Bool -- True <=> ignore rules
528 tcIfaceRules ignore_prags if_rules
529 | ignore_prags = return []
530 | otherwise = mapM tcIfaceRule if_rules
532 tcIfaceRule :: IfaceRule -> IfL CoreRule
533 tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,
534 ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs,
536 = do { ~(bndrs', args', rhs') <-
537 -- Typecheck the payload lazily, in the hope it'll never be looked at
538 forkM (ptext SLIT("Rule") <+> ftext name) $
539 bindIfaceBndrs bndrs $ \ bndrs' ->
540 do { args' <- mappM tcIfaceExpr args
541 ; rhs' <- tcIfaceExpr rhs
542 ; return (bndrs', args', rhs') }
543 ; let mb_tcs = map ifTopFreeName args
545 ; let this_module = if_mod lcl
546 ; returnM (Rule { ru_name = name, ru_fn = fn, ru_act = act,
547 ru_bndrs = bndrs', ru_args = args',
548 ru_rhs = rhs', ru_orph = orph,
550 ru_local = nameModule fn == this_module }) }
552 -- This function *must* mirror exactly what Rules.topFreeName does
553 -- We could have stored the ru_rough field in the iface file
554 -- but that would be redundant, I think.
555 -- The only wrinkle is that we must not be deceived by
556 -- type syononyms at the top of a type arg. Since
557 -- we can't tell at this point, we are careful not
558 -- to write them out in coreRuleToIfaceRule
559 ifTopFreeName :: IfaceExpr -> Maybe Name
560 ifTopFreeName (IfaceType (IfaceTyConApp tc _ )) = Just (ifaceTyConName tc)
561 ifTopFreeName (IfaceApp f a) = ifTopFreeName f
562 ifTopFreeName (IfaceExt n) = Just n
563 ifTopFreeName other = Nothing
567 %************************************************************************
571 %************************************************************************
574 tcIfaceType :: IfaceType -> IfL Type
575 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
576 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
577 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
578 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkTyConApp tc' ts') }
579 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
580 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
582 tcIfaceTypes tys = mapM tcIfaceType tys
584 -----------------------------------------
585 tcIfacePredType :: IfacePredType -> IfL PredType
586 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
587 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
588 tcIfacePredType (IfaceEqPred t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (EqPred t1' t2') }
590 -----------------------------------------
591 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
592 tcIfaceCtxt sts = mappM tcIfacePredType sts
596 %************************************************************************
600 %************************************************************************
603 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
604 tcIfaceExpr (IfaceType ty)
605 = tcIfaceType ty `thenM` \ ty' ->
608 tcIfaceExpr (IfaceLcl name)
609 = tcIfaceLclId name `thenM` \ id ->
612 tcIfaceExpr (IfaceExt gbl)
613 = tcIfaceExtId gbl `thenM` \ id ->
616 tcIfaceExpr (IfaceLit lit)
619 tcIfaceExpr (IfaceFCall cc ty)
620 = tcIfaceType ty `thenM` \ ty' ->
621 newUnique `thenM` \ u ->
622 returnM (Var (mkFCallId u cc ty'))
624 tcIfaceExpr (IfaceTuple boxity args)
625 = mappM tcIfaceExpr args `thenM` \ args' ->
627 -- Put the missing type arguments back in
628 con_args = map (Type . exprType) args' ++ args'
630 returnM (mkApps (Var con_id) con_args)
633 con_id = dataConWorkId (tupleCon boxity arity)
636 tcIfaceExpr (IfaceLam bndr body)
637 = bindIfaceBndr bndr $ \ bndr' ->
638 tcIfaceExpr body `thenM` \ body' ->
639 returnM (Lam bndr' body')
641 tcIfaceExpr (IfaceApp fun arg)
642 = tcIfaceExpr fun `thenM` \ fun' ->
643 tcIfaceExpr arg `thenM` \ arg' ->
644 returnM (App fun' arg')
646 tcIfaceExpr (IfaceCase scrut case_bndr ty alts)
647 = tcIfaceExpr scrut `thenM` \ scrut' ->
648 newIfaceName (mkVarOccFS case_bndr) `thenM` \ case_bndr_name ->
650 scrut_ty = exprType scrut'
651 case_bndr' = mkLocalId case_bndr_name scrut_ty
652 tc_app = splitTyConApp scrut_ty
653 -- NB: Won't always succeed (polymoprhic case)
654 -- but won't be demanded in those cases
655 -- NB: not tcSplitTyConApp; we are looking at Core here
656 -- look through non-rec newtypes to find the tycon that
657 -- corresponds to the datacon in this case alternative
659 extendIfaceIdEnv [case_bndr'] $
660 mappM (tcIfaceAlt tc_app) alts `thenM` \ alts' ->
661 tcIfaceType ty `thenM` \ ty' ->
662 returnM (Case scrut' case_bndr' ty' alts')
664 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body)
665 = tcIfaceExpr rhs `thenM` \ rhs' ->
666 bindIfaceId bndr $ \ bndr' ->
667 tcIfaceExpr body `thenM` \ body' ->
668 returnM (Let (NonRec bndr' rhs') body')
670 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
671 = bindIfaceIds bndrs $ \ bndrs' ->
672 mappM tcIfaceExpr rhss `thenM` \ rhss' ->
673 tcIfaceExpr body `thenM` \ body' ->
674 returnM (Let (Rec (bndrs' `zip` rhss')) body')
676 (bndrs, rhss) = unzip pairs
678 tcIfaceExpr (IfaceCast expr co) = do
679 expr' <- tcIfaceExpr expr
680 co' <- tcIfaceType co
681 returnM (Cast expr' co')
683 tcIfaceExpr (IfaceNote note expr)
684 = tcIfaceExpr expr `thenM` \ expr' ->
686 IfaceInlineMe -> returnM (Note InlineMe expr')
687 IfaceSCC cc -> returnM (Note (SCC cc) expr')
688 IfaceCoreNote n -> returnM (Note (CoreNote n) expr')
689 IfaceTickBox m n -> returnM (Note (TickBox m n) expr')
690 IfaceBinaryTickBox m t e -> returnM (Note (BinaryTickBox m t e) expr')
692 -------------------------
693 tcIfaceAlt _ (IfaceDefault, names, rhs)
694 = ASSERT( null names )
695 tcIfaceExpr rhs `thenM` \ rhs' ->
696 returnM (DEFAULT, [], rhs')
698 tcIfaceAlt _ (IfaceLitAlt lit, names, rhs)
699 = ASSERT( null names )
700 tcIfaceExpr rhs `thenM` \ rhs' ->
701 returnM (LitAlt lit, [], rhs')
703 -- A case alternative is made quite a bit more complicated
704 -- by the fact that we omit type annotations because we can
705 -- work them out. True enough, but its not that easy!
706 tcIfaceAlt (tycon, inst_tys) (IfaceDataAlt data_occ, arg_strs, rhs)
707 = do { con <- tcIfaceDataCon data_occ
708 ; ASSERT2( con `elem` tyConDataCons tycon,
709 ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon) )
710 tcIfaceDataAlt con inst_tys arg_strs rhs }
712 tcIfaceAlt (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
713 = ASSERT( isTupleTyCon tycon )
714 do { let [data_con] = tyConDataCons tycon
715 ; tcIfaceDataAlt data_con inst_tys arg_occs rhs }
717 tcIfaceDataAlt con inst_tys arg_strs rhs
718 = do { us <- newUniqueSupply
719 ; let uniqs = uniqsFromSupply us
720 ; let (ex_tvs, co_tvs, arg_ids)
721 = dataConRepFSInstPat arg_strs uniqs con inst_tys
722 all_tvs = ex_tvs ++ co_tvs
724 ; rhs' <- extendIfaceTyVarEnv all_tvs $
725 extendIfaceIdEnv arg_ids $
727 ; return (DataAlt con, all_tvs ++ arg_ids, rhs') }
732 tcExtCoreBindings :: [IfaceBinding] -> IfL [CoreBind] -- Used for external core
733 tcExtCoreBindings [] = return []
734 tcExtCoreBindings (b:bs) = do_one b (tcExtCoreBindings bs)
736 do_one :: IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
737 do_one (IfaceNonRec bndr rhs) thing_inside
738 = do { rhs' <- tcIfaceExpr rhs
739 ; bndr' <- newExtCoreBndr bndr
740 ; extendIfaceIdEnv [bndr'] $ do
741 { core_binds <- thing_inside
742 ; return (NonRec bndr' rhs' : core_binds) }}
744 do_one (IfaceRec pairs) thing_inside
745 = do { bndrs' <- mappM newExtCoreBndr bndrs
746 ; extendIfaceIdEnv bndrs' $ do
747 { rhss' <- mappM tcIfaceExpr rhss
748 ; core_binds <- thing_inside
749 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
751 (bndrs,rhss) = unzip pairs
755 %************************************************************************
759 %************************************************************************
762 tcIdInfo :: Bool -> Name -> Type -> IfaceIdInfo -> IfL IdInfo
763 tcIdInfo ignore_prags name ty info
764 | ignore_prags = return vanillaIdInfo
765 | otherwise = case info of
766 NoInfo -> return vanillaIdInfo
767 HasInfo info -> foldlM tcPrag init_info info
769 -- Set the CgInfo to something sensible but uninformative before
770 -- we start; default assumption is that it has CAFs
771 init_info = vanillaIdInfo
773 tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
774 tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
775 tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
777 -- The next two are lazy, so they don't transitively suck stuff in
778 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
779 tcPrag info (HsInline inline_prag) = returnM (info `setInlinePragInfo` inline_prag)
780 tcPrag info (HsUnfold expr)
781 = tcPragExpr name expr `thenM` \ maybe_expr' ->
783 -- maybe_expr' doesn't get looked at if the unfolding
784 -- is never inspected; so the typecheck doesn't even happen
785 unfold_info = case maybe_expr' of
786 Nothing -> noUnfolding
787 Just expr' -> mkTopUnfolding expr'
789 returnM (info `setUnfoldingInfoLazily` unfold_info)
793 tcWorkerInfo ty info wkr arity
794 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId wkr)
796 -- We return without testing maybe_wkr_id, but as soon as info is
797 -- looked at we will test it. That's ok, because its outside the
798 -- knot; and there seems no big reason to further defer the
799 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
800 -- over the unfolding until it's actually used does seem worth while.)
801 ; us <- newUniqueSupply
803 ; returnM (case mb_wkr_id of
805 Just wkr_id -> add_wkr_info us wkr_id info) }
807 doc = text "Worker for" <+> ppr wkr
808 add_wkr_info us wkr_id info
809 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
810 `setWorkerInfo` HasWorker wkr_id arity
812 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
814 -- We are relying here on strictness info always appearing
815 -- before worker info, fingers crossed ....
816 strict_sig = case newStrictnessInfo info of
818 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr)
821 For unfoldings we try to do the job lazily, so that we never type check
822 an unfolding that isn't going to be looked at.
825 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
828 tcIfaceExpr expr `thenM` \ core_expr' ->
830 -- Check for type consistency in the unfolding
831 ifOptM Opt_DoCoreLinting (
832 get_in_scope_ids `thenM` \ in_scope ->
833 case lintUnfolding noSrcLoc in_scope core_expr' of
834 Nothing -> returnM ()
835 Just fail_msg -> pprPanic "Iface Lint failure" (hang doc 2 fail_msg)
840 doc = text "Unfolding of" <+> ppr name
841 get_in_scope_ids -- Urgh; but just for linting
843 do { env <- getGblEnv
844 ; case if_rec_types env of {
845 Nothing -> return [] ;
846 Just (_, get_env) -> do
847 { type_env <- get_env
848 ; return (typeEnvIds type_env) }}}
853 %************************************************************************
855 Getting from Names to TyThings
857 %************************************************************************
860 tcIfaceGlobal :: Name -> IfL TyThing
862 | Just thing <- wiredInNameTyThing_maybe name
863 -- Wired-in things include TyCons, DataCons, and Ids
864 = do { ifCheckWiredInThing name; return thing }
866 = do { (eps,hpt) <- getEpsAndHpt
868 ; case lookupType dflags hpt (eps_PTE eps) name of {
869 Just thing -> return thing ;
873 ; case if_rec_types env of {
874 Just (mod, get_type_env)
875 | nameIsLocalOrFrom mod name
876 -> do -- It's defined in the module being compiled
877 { type_env <- setLclEnv () get_type_env -- yuk
878 ; case lookupNameEnv type_env name of
879 Just thing -> return thing
880 Nothing -> pprPanic "tcIfaceGlobal (local): not found:"
881 (ppr name $$ ppr type_env) }
885 { mb_thing <- importDecl name -- It's imported; go get it
887 Failed err -> failIfM err
888 Succeeded thing -> return thing
891 ifCheckWiredInThing :: Name -> IfL ()
892 -- Even though we are in an interface file, we want to make
893 -- sure the instances of a wired-in thing are loaded (imagine f :: Double -> Double)
894 -- Ditto want to ensure that RULES are loaded too
895 ifCheckWiredInThing name
896 = do { mod <- getIfModule
897 -- Check whether we are typechecking the interface for this
898 -- very module. E.g when compiling the base library in --make mode
899 -- we may typecheck GHC.Base.hi. At that point, GHC.Base is not in
900 -- the HPT, so without the test we'll demand-load it into the PIT!
901 -- C.f. the same test in checkWiredInTyCon above
902 ; unless (mod == nameModule name)
903 (loadWiredInHomeIface name) }
905 tcIfaceTyCon :: IfaceTyCon -> IfL TyCon
906 tcIfaceTyCon IfaceIntTc = tcWiredInTyCon intTyCon
907 tcIfaceTyCon IfaceBoolTc = tcWiredInTyCon boolTyCon
908 tcIfaceTyCon IfaceCharTc = tcWiredInTyCon charTyCon
909 tcIfaceTyCon IfaceListTc = tcWiredInTyCon listTyCon
910 tcIfaceTyCon IfacePArrTc = tcWiredInTyCon parrTyCon
911 tcIfaceTyCon (IfaceTupTc bx ar) = tcWiredInTyCon (tupleTyCon bx ar)
912 tcIfaceTyCon (IfaceTc name) = do { thing <- tcIfaceGlobal name
913 ; return (check_tc (tyThingTyCon thing)) }
916 check_tc tc = case toIfaceTyCon tc of
918 other -> pprTrace "check_tc" (ppr tc) tc
922 -- we should be okay just returning Kind constructors without extra loading
923 tcIfaceTyCon IfaceLiftedTypeKindTc = return liftedTypeKindTyCon
924 tcIfaceTyCon IfaceOpenTypeKindTc = return openTypeKindTyCon
925 tcIfaceTyCon IfaceUnliftedTypeKindTc = return unliftedTypeKindTyCon
926 tcIfaceTyCon IfaceArgTypeKindTc = return argTypeKindTyCon
927 tcIfaceTyCon IfaceUbxTupleKindTc = return ubxTupleKindTyCon
929 -- Even though we are in an interface file, we want to make
930 -- sure the instances and RULES of this tycon are loaded
931 -- Imagine: f :: Double -> Double
932 tcWiredInTyCon :: TyCon -> IfL TyCon
933 tcWiredInTyCon tc = do { ifCheckWiredInThing (tyConName tc)
936 tcIfaceClass :: Name -> IfL Class
937 tcIfaceClass name = do { thing <- tcIfaceGlobal name
938 ; return (tyThingClass thing) }
940 tcIfaceDataCon :: Name -> IfL DataCon
941 tcIfaceDataCon name = do { thing <- tcIfaceGlobal name
943 ADataCon dc -> return dc
944 other -> pprPanic "tcIfaceExtDC" (ppr name$$ ppr thing) }
946 tcIfaceExtId :: Name -> IfL Id
947 tcIfaceExtId name = do { thing <- tcIfaceGlobal name
950 other -> pprPanic "tcIfaceExtId" (ppr name$$ ppr thing) }
953 %************************************************************************
957 %************************************************************************
960 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
961 bindIfaceBndr (IfaceIdBndr bndr) thing_inside
962 = bindIfaceId bndr thing_inside
963 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
964 = bindIfaceTyVar bndr thing_inside
966 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
967 bindIfaceBndrs [] thing_inside = thing_inside []
968 bindIfaceBndrs (b:bs) thing_inside
969 = bindIfaceBndr b $ \ b' ->
970 bindIfaceBndrs bs $ \ bs' ->
971 thing_inside (b':bs')
973 -----------------------
974 bindIfaceId :: IfaceIdBndr -> (Id -> IfL a) -> IfL a
975 bindIfaceId (occ, ty) thing_inside
976 = do { name <- newIfaceName (mkVarOccFS occ)
977 ; ty' <- tcIfaceType ty
978 ; let { id = mkLocalId name ty' }
979 ; extendIfaceIdEnv [id] (thing_inside id) }
981 bindIfaceIds :: [IfaceIdBndr] -> ([Id] -> IfL a) -> IfL a
982 bindIfaceIds bndrs thing_inside
983 = do { names <- newIfaceNames (map mkVarOccFS occs)
984 ; tys' <- mappM tcIfaceType tys
985 ; let { ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys' }
986 ; extendIfaceIdEnv ids (thing_inside ids) }
988 (occs,tys) = unzip bndrs
991 -----------------------
992 newExtCoreBndr :: IfaceIdBndr -> IfL Id
993 newExtCoreBndr (var, ty)
994 = do { mod <- getIfModule
995 ; name <- newGlobalBinder mod (mkVarOccFS var) noSrcLoc
996 ; ty' <- tcIfaceType ty
997 ; return (mkLocalId name ty') }
999 -----------------------
1000 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
1001 bindIfaceTyVar (occ,kind) thing_inside
1002 = do { name <- newIfaceName (mkTyVarOcc occ)
1003 ; tyvar <- mk_iface_tyvar name kind
1004 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
1006 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
1007 bindIfaceTyVars bndrs thing_inside
1008 = do { names <- newIfaceNames (map mkTyVarOcc occs)
1009 ; tyvars <- TcRnMonad.zipWithM mk_iface_tyvar names kinds
1010 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
1012 (occs,kinds) = unzip bndrs
1014 mk_iface_tyvar :: Name -> IfaceKind -> IfL TyVar
1015 mk_iface_tyvar name ifKind
1016 = do { kind <- tcIfaceType ifKind
1017 ; if isCoercionKind kind then
1018 return (Var.mkCoVar name kind)
1020 return (Var.mkTyVar name kind) }