2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[TcIfaceSig]{Type checking of type signatures in interface files}
8 tcImportDecl, checkWiredInTyCon, tcHiBootIface, typecheckIface,
9 tcIfaceDecl, tcIfaceInst, tcIfaceRule, tcIfaceGlobal,
13 #include "HsVersions.h"
16 import LoadIface ( loadInterface, loadWiredInHomeIface,
17 loadDecls, findAndReadIface )
18 import IfaceEnv ( lookupIfaceTop, lookupIfaceExt, newGlobalBinder,
19 extendIfaceIdEnv, extendIfaceTyVarEnv, newIPName,
20 tcIfaceTyVar, tcIfaceLclId, lookupIfaceTc,
21 newIfaceName, newIfaceNames, ifaceExportNames )
22 import BuildTyCl ( buildSynTyCon, buildAlgTyCon, buildDataCon,
24 mkAbstractTyConRhs, mkOpenDataTyConRhs,
25 mkOpenNewTyConRhs, mkDataTyConRhs, mkNewTyConRhs )
27 import Type ( liftedTypeKind, splitTyConApp, mkTyConApp,
28 liftedTypeKindTyCon, unliftedTypeKindTyCon,
29 openTypeKindTyCon, argTypeKindTyCon,
30 ubxTupleKindTyCon, ThetaType )
31 import TypeRep ( Type(..), PredType(..) )
32 import TyCon ( TyCon, tyConName, SynTyConRhs(..), setTyConArgPoss )
33 import HscTypes ( ExternalPackageState(..),
34 TyThing(..), tyThingClass, tyThingTyCon,
35 ModIface(..), ModDetails(..), HomeModInfo(..),
36 emptyModDetails, lookupTypeEnv, lookupType,
37 typeEnvIds, mkDetailsFamInstCache )
38 import InstEnv ( Instance(..), mkImportedInstance )
40 import CoreUtils ( exprType, dataConRepFSInstPat )
42 import CoreLint ( lintUnfolding )
43 import WorkWrap ( mkWrapper )
44 import Id ( Id, mkVanillaGlobal, mkLocalId )
45 import MkId ( mkFCallId )
46 import IdInfo ( IdInfo, CafInfo(..), WorkerInfo(..),
47 setUnfoldingInfoLazily, setAllStrictnessInfo, setWorkerInfo,
48 setArityInfo, setInlinePragInfo, setCafInfo,
49 vanillaIdInfo, newStrictnessInfo )
50 import Class ( Class )
51 import TyCon ( tyConDataCons, isTupleTyCon, mkForeignTyCon )
52 import DataCon ( DataCon, dataConWorkId )
53 import TysWiredIn ( tupleCon, tupleTyCon, listTyCon, intTyCon, boolTyCon, charTyCon, parrTyCon )
54 import Var ( TyVar, mkTyVar )
55 import Name ( Name, nameModule, nameIsLocalOrFrom, isWiredInName,
56 nameOccName, wiredInNameTyThing_maybe )
58 import OccName ( OccName, mkVarOccFS, mkTyVarOcc, occNameSpace,
59 pprNameSpace, occNameFS )
60 import FastString ( FastString )
61 import Module ( Module, moduleName )
62 import UniqFM ( lookupUFM )
63 import UniqSupply ( initUs_, uniqsFromSupply )
65 import ErrUtils ( Message )
66 import Maybes ( MaybeErr(..) )
67 import SrcLoc ( noSrcLoc )
68 import Util ( zipWithEqual, equalLength )
69 import DynFlags ( DynFlag(..), isOneShot )
71 import List ( elemIndex)
72 import Maybe ( catMaybes )
81 An IfaceDecl is populated with RdrNames, and these are not renamed to
82 Names before typechecking, because there should be no scope errors etc.
84 -- For (b) consider: f = $(...h....)
85 -- where h is imported, and calls f via an hi-boot file.
86 -- This is bad! But it is not seen as a staging error, because h
87 -- is indeed imported. We don't want the type-checker to black-hole
88 -- when simplifying and compiling the splice!
90 -- Simple solution: discard any unfolding that mentions a variable
91 -- bound in this module (and hence not yet processed).
92 -- The discarding happens when forkM finds a type error.
94 %************************************************************************
96 %* tcImportDecl is the key function for "faulting in" *
99 %************************************************************************
101 The main idea is this. We are chugging along type-checking source code, and
102 find a reference to GHC.Base.map. We call tcLookupGlobal, which doesn't find
103 it in the EPS type envt. So it
105 2 gets the decl for GHC.Base.map
106 3 typechecks it via tcIfaceDecl
107 4 and adds it to the type env in the EPS
109 Note that DURING STEP 4, we may find that map's type mentions a type
110 constructor that also
112 Notice that for imported things we read the current version from the EPS
113 mutable variable. This is important in situations like
115 where the code that e1 expands to might import some defns that
116 also turn out to be needed by the code that e2 expands to.
119 tcImportDecl :: Name -> TcM TyThing
120 -- Entry point for *source-code* uses of importDecl
122 | Just thing <- wiredInNameTyThing_maybe name
123 = do { initIfaceTcRn (loadWiredInHomeIface name)
126 = do { traceIf (text "tcImportDecl" <+> ppr name)
127 ; mb_thing <- initIfaceTcRn (importDecl name)
129 Succeeded thing -> return thing
130 Failed err -> failWithTc err }
132 checkWiredInTyCon :: TyCon -> TcM ()
133 -- Ensure that the home module of the TyCon (and hence its instances)
134 -- are loaded. It might not be a wired-in tycon (see the calls in TcUnify),
135 -- in which case this is a no-op.
137 | not (isWiredInName tc_name)
140 = do { mod <- getModule
141 ; if nameIsLocalOrFrom mod tc_name then
142 -- Don't look for (non-existent) Float.hi when
143 -- compiling Float.lhs, which mentions Float of course
145 else -- A bit yukky to call initIfaceTcRn here
146 initIfaceTcRn (loadWiredInHomeIface tc_name)
149 tc_name = tyConName tc
151 importDecl :: Name -> IfM lcl (MaybeErr Message TyThing)
152 -- Get the TyThing for this Name from an interface file
153 -- It's not a wired-in thing -- the caller caught that
155 = ASSERT( not (isWiredInName name) )
158 -- Load the interface, which should populate the PTE
159 ; mb_iface <- loadInterface nd_doc (nameModule name) ImportBySystem
161 Failed err_msg -> return (Failed err_msg) ;
162 Succeeded iface -> do
164 -- Now look it up again; this time we should find it
166 ; case lookupTypeEnv (eps_PTE eps) name of
167 Just thing -> return (Succeeded thing)
168 Nothing -> return (Failed not_found_msg)
171 nd_doc = ptext SLIT("Need decl for") <+> ppr name
172 not_found_msg = hang (ptext SLIT("Can't find interface-file declaration for") <+>
173 pprNameSpace (occNameSpace (nameOccName name)) <+> ppr name)
174 2 (vcat [ptext SLIT("Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
175 ptext SLIT("Use -ddump-if-trace to get an idea of which file caused the error")])
178 %************************************************************************
180 Type-checking a complete interface
182 %************************************************************************
184 Suppose we discover we don't need to recompile. Then we must type
185 check the old interface file. This is a bit different to the
186 incremental type checking we do as we suck in interface files. Instead
187 we do things similarly as when we are typechecking source decls: we
188 bring into scope the type envt for the interface all at once, using a
189 knot. Remember, the decls aren't necessarily in dependency order --
190 and even if they were, the type decls might be mutually recursive.
193 typecheckIface :: ModIface -- Get the decls from here
194 -> TcRnIf gbl lcl ModDetails
196 = initIfaceTc iface $ \ tc_env_var -> do
197 -- The tc_env_var is freshly allocated, private to
198 -- type-checking this particular interface
199 { -- Get the right set of decls and rules. If we are compiling without -O
200 -- we discard pragmas before typechecking, so that we don't "see"
201 -- information that we shouldn't. From a versioning point of view
202 -- It's not actually *wrong* to do so, but in fact GHCi is unable
203 -- to handle unboxed tuples, so it must not see unfoldings.
204 ignore_prags <- doptM Opt_IgnoreInterfacePragmas
206 -- Load & typecheck the decls
207 ; decl_things <- loadDecls ignore_prags (mi_decls iface)
209 ; let type_env = mkNameEnv decl_things
210 ; writeMutVar tc_env_var type_env
212 -- Now do those rules and instances
213 ; let { rules | ignore_prags = []
214 | otherwise = mi_rules iface
215 ; dfuns = mi_insts iface
217 ; dfuns <- mapM tcIfaceInst dfuns
218 ; rules <- mapM tcIfaceRule rules
221 ; exports <- ifaceExportNames (mi_exports iface)
224 ; return $ ModDetails { md_types = type_env
226 , md_fam_insts = mkDetailsFamInstCache type_env
228 , md_exports = exports
234 %************************************************************************
236 Type and class declarations
238 %************************************************************************
241 tcHiBootIface :: Module -> TcRn ModDetails
242 -- Load the hi-boot iface for the module being compiled,
243 -- if it indeed exists in the transitive closure of imports
244 -- Return the ModDetails, empty if no hi-boot iface
246 = do { traceIf (text "loadHiBootInterface" <+> ppr mod)
249 ; if not (isOneShot mode)
250 -- In --make and interactive mode, if this module has an hs-boot file
251 -- we'll have compiled it already, and it'll be in the HPT
253 -- We check wheher the interface is a *boot* interface.
254 -- It can happen (when using GHC from Visual Studio) that we
255 -- compile a module in TypecheckOnly mode, with a stable,
256 -- fully-populated HPT. In that case the boot interface isn't there
257 -- (it's been replaced by the mother module) so we can't check it.
258 -- And that's fine, because if M's ModInfo is in the HPT, then
259 -- it's been compiled once, and we don't need to check the boot iface
260 then do { hpt <- getHpt
261 ; case lookupUFM hpt (moduleName mod) of
262 Just info | mi_boot (hm_iface info)
263 -> return (hm_details info)
264 other -> return emptyModDetails }
267 -- OK, so we're in one-shot mode.
268 -- In that case, we're read all the direct imports by now,
269 -- so eps_is_boot will record if any of our imports mention us by
270 -- way of hi-boot file
272 ; case lookupUFM (eps_is_boot eps) (moduleName mod) of {
273 Nothing -> return emptyModDetails ; -- The typical case
275 Just (_, False) -> failWithTc moduleLoop ;
276 -- Someone below us imported us!
277 -- This is a loop with no hi-boot in the way
279 Just (_mod, True) -> -- There's a hi-boot interface below us
281 do { read_result <- findAndReadIface
285 ; case read_result of
286 Failed err -> failWithTc (elaborate err)
287 Succeeded (iface, _path) -> typecheckIface iface
290 need = ptext SLIT("Need the hi-boot interface for") <+> ppr mod
291 <+> ptext SLIT("to compare against the Real Thing")
293 moduleLoop = ptext SLIT("Circular imports: module") <+> quotes (ppr mod)
294 <+> ptext SLIT("depends on itself")
296 elaborate err = hang (ptext SLIT("Could not find hi-boot interface for") <+>
297 quotes (ppr mod) <> colon) 4 err
301 %************************************************************************
303 Type and class declarations
305 %************************************************************************
307 When typechecking a data type decl, we *lazily* (via forkM) typecheck
308 the constructor argument types. This is in the hope that we may never
309 poke on those argument types, and hence may never need to load the
310 interface files for types mentioned in the arg types.
313 data Foo.S = MkS Baz.T
314 Mabye we can get away without even loading the interface for Baz!
316 This is not just a performance thing. Suppose we have
317 data Foo.S = MkS Baz.T
318 data Baz.T = MkT Foo.S
319 (in different interface files, of course).
320 Now, first we load and typecheck Foo.S, and add it to the type envt.
321 If we do explore MkS's argument, we'll load and typecheck Baz.T.
322 If we explore MkT's argument we'll find Foo.S already in the envt.
324 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
325 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
326 which isn't done yet.
328 All very cunning. However, there is a rather subtle gotcha which bit
329 me when developing this stuff. When we typecheck the decl for S, we
330 extend the type envt with S, MkS, and all its implicit Ids. Suppose
331 (a bug, but it happened) that the list of implicit Ids depended in
332 turn on the constructor arg types. Then the following sequence of
334 * we build a thunk <t> for the constructor arg tys
335 * we build a thunk for the extended type environment (depends on <t>)
336 * we write the extended type envt into the global EPS mutvar
338 Now we look something up in the type envt
340 * which reads the global type envt out of the global EPS mutvar
341 * but that depends in turn on <t>
343 It's subtle, because, it'd work fine if we typechecked the constructor args
344 eagerly -- they don't need the extended type envt. They just get the extended
345 type envt by accident, because they look at it later.
347 What this means is that the implicitTyThings MUST NOT DEPEND on any of
352 tcIfaceDecl :: IfaceDecl -> IfL TyThing
354 tcIfaceDecl (IfaceId {ifName = occ_name, ifType = iface_type, ifIdInfo = info})
355 = do { name <- lookupIfaceTop occ_name
356 ; ty <- tcIfaceType iface_type
357 ; info <- tcIdInfo name ty info
358 ; return (AnId (mkVanillaGlobal name ty info)) }
360 tcIfaceDecl (IfaceData {ifName = occ_name,
362 ifCtxt = ctxt, ifGadtSyntax = gadt_syn,
365 ifGeneric = want_generic,
366 ifFamInst = mb_family })
367 = do { tc_name <- lookupIfaceTop occ_name
368 ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
370 { tycon <- fixM ( \ tycon -> do
371 { stupid_theta <- tcIfaceCtxt ctxt
374 Nothing -> return Nothing
375 Just (IfaceFamInst { ifFamInstTyCon = fam
378 do { famTyCon <- tcIfaceTyCon fam
379 ; insttys <- mapM tcIfaceType tys
380 ; return $ Just (famTyCon, insttys)
382 ; cons <- tcIfaceDataCons tc_name tycon tyvars rdr_cons
383 ; buildAlgTyCon tc_name tyvars stupid_theta
384 cons is_rec want_generic gadt_syn famInst
386 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
387 ; return (ATyCon tycon)
390 tcIfaceDecl (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
391 ifOpenSyn = isOpen, ifSynRhs = rdr_rhs_ty})
392 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
393 { tc_name <- lookupIfaceTop occ_name
394 ; rhs_tyki <- tcIfaceType rdr_rhs_ty
395 ; let rhs = if isOpen then OpenSynTyCon rhs_tyki
396 else SynonymTyCon rhs_tyki
397 ; return (ATyCon (buildSynTyCon tc_name tyvars rhs))
400 tcIfaceDecl (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name,
401 ifTyVars = tv_bndrs, ifFDs = rdr_fds,
402 ifATs = rdr_ats, ifSigs = rdr_sigs,
404 -- ToDo: in hs-boot files we should really treat abstract classes specially,
405 -- as we do abstract tycons
406 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
407 { cls_name <- lookupIfaceTop occ_name
408 ; ctxt <- tcIfaceCtxt rdr_ctxt
409 ; sigs <- mappM tc_sig rdr_sigs
410 ; fds <- mappM tc_fd rdr_fds
411 ; ats' <- mappM tcIfaceDecl rdr_ats
412 ; let ats = zipWith setTyThingPoss ats' (map ifTyVars rdr_ats)
413 ; cls <- buildClass cls_name tyvars ctxt fds ats sigs tc_isrec
414 ; return (AClass cls) }
416 tc_sig (IfaceClassOp occ dm rdr_ty)
417 = do { op_name <- lookupIfaceTop occ
418 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
419 -- Must be done lazily for just the same reason as the
420 -- context of a data decl: the type sig might mention the
421 -- class being defined
422 ; return (op_name, dm, op_ty) }
424 mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
426 tc_fd (tvs1, tvs2) = do { tvs1' <- mappM tcIfaceTyVar tvs1
427 ; tvs2' <- mappM tcIfaceTyVar tvs2
428 ; return (tvs1', tvs2') }
430 -- For each AT argument compute the position of the corresponding class
431 -- parameter in the class head. This will later serve as a permutation
432 -- vector when checking the validity of instance declarations.
433 setTyThingPoss (ATyCon tycon) atTyVars =
434 let classTyVars = map fst tv_bndrs
436 . map ((`elemIndex` classTyVars) . fst)
438 -- There will be no Nothing, as we already passed renaming
440 ATyCon (setTyConArgPoss tycon poss)
441 setTyThingPoss _ _ = panic "TcIface.setTyThingPoss"
443 tcIfaceDecl (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
444 = do { name <- lookupIfaceTop rdr_name
445 ; return (ATyCon (mkForeignTyCon name ext_name
448 tcIfaceDataCons tycon_name tycon tc_tyvars if_cons
450 IfAbstractTyCon -> return mkAbstractTyConRhs
451 IfOpenDataTyCon -> return mkOpenDataTyConRhs
452 IfOpenNewTyCon -> return mkOpenNewTyConRhs
453 IfDataTyCon cons -> do { data_cons <- mappM tc_con_decl cons
454 ; return (mkDataTyConRhs data_cons) }
455 IfNewTyCon con -> do { data_con <- tc_con_decl con
456 ; mkNewTyConRhs tycon_name tycon data_con }
458 tc_con_decl (IfCon { ifConInfix = is_infix,
459 ifConUnivTvs = univ_tvs, ifConExTvs = ex_tvs,
460 ifConOcc = occ, ifConCtxt = ctxt, ifConEqSpec = spec,
461 ifConArgTys = args, ifConFields = field_lbls,
462 ifConStricts = stricts})
463 = bindIfaceTyVars univ_tvs $ \ univ_tyvars -> do
464 bindIfaceTyVars ex_tvs $ \ ex_tyvars -> do
465 { name <- lookupIfaceTop occ
466 ; eq_spec <- tcIfaceEqSpec spec
467 ; theta <- tcIfaceCtxt ctxt -- Laziness seems not worth the bother here
468 -- At one stage I thought that this context checking *had*
469 -- to be lazy, because of possible mutual recursion between the
470 -- type and the classe:
472 -- class Real a where { toRat :: a -> Ratio Integer }
473 -- data (Real a) => Ratio a = ...
474 -- But now I think that the laziness in checking class ops breaks
475 -- the loop, so no laziness needed
477 -- Read the argument types, but lazily to avoid faulting in
478 -- the component types unless they are really needed
479 ; arg_tys <- forkM (mk_doc name) (mappM tcIfaceType args)
480 ; lbl_names <- mappM lookupIfaceTop field_lbls
482 ; buildDataCon name is_infix {- Not infix -}
484 univ_tyvars ex_tyvars
488 mk_doc con_name = ptext SLIT("Constructor") <+> ppr con_name
493 do_item (occ, if_ty) = do { tv <- tcIfaceTyVar (occNameFS occ)
494 ; ty <- tcIfaceType if_ty
499 %************************************************************************
503 %************************************************************************
506 tcIfaceInst :: IfaceInst -> IfL Instance
507 tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
508 ifInstCls = cls, ifInstTys = mb_tcs,
510 = do { dfun <- forkM (ptext SLIT("Dict fun") <+> ppr dfun_occ) $
511 tcIfaceExtId (LocalTop dfun_occ)
512 ; cls' <- lookupIfaceExt cls
513 ; mb_tcs' <- mapM do_tc mb_tcs
514 ; return (mkImportedInstance cls' mb_tcs' orph dfun oflag) }
516 do_tc Nothing = return Nothing
517 do_tc (Just tc) = do { tc' <- lookupIfaceTc tc; return (Just tc') }
521 %************************************************************************
525 %************************************************************************
527 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
528 are in the type environment. However, remember that typechecking a Rule may
529 (as a side effect) augment the type envt, and so we may need to iterate the process.
532 tcIfaceRule :: IfaceRule -> IfL CoreRule
533 tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,
534 ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs,
536 = do { fn' <- lookupIfaceExt fn
537 ; ~(bndrs', args', rhs') <-
538 -- Typecheck the payload lazily, in the hope it'll never be looked at
539 forkM (ptext SLIT("Rule") <+> ftext name) $
540 bindIfaceBndrs bndrs $ \ bndrs' ->
541 do { args' <- mappM tcIfaceExpr args
542 ; rhs' <- tcIfaceExpr rhs
543 ; return (bndrs', args', rhs') }
544 ; mb_tcs <- mapM ifTopFreeName args
545 ; returnM (Rule { ru_name = name, ru_fn = fn', ru_act = act,
546 ru_bndrs = bndrs', ru_args = args',
547 ru_rhs = rhs', ru_orph = orph,
549 ru_local = isLocalIfaceExtName fn }) }
551 -- This function *must* mirror exactly what Rules.topFreeName does
552 -- We could have stored the ru_rough field in the iface file
553 -- but that would be redundant, I think.
554 -- The only wrinkle is that we must not be deceived by
555 -- type syononyms at the top of a type arg. Since
556 -- we can't tell at this point, we are careful not
557 -- to write them out in coreRuleToIfaceRule
558 ifTopFreeName :: IfaceExpr -> IfL (Maybe Name)
559 ifTopFreeName (IfaceType (IfaceTyConApp tc _ ))
560 = do { n <- lookupIfaceTc tc
562 ifTopFreeName (IfaceApp f a) = ifTopFreeName f
563 ifTopFreeName (IfaceExt ext) = do { n <- lookupIfaceExt ext
565 ifTopFreeName other = return Nothing
569 %************************************************************************
573 %************************************************************************
576 tcIfaceType :: IfaceType -> IfL Type
577 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
578 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
579 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
580 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkTyConApp tc' ts') }
581 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
582 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
584 tcIfaceTypes tys = mapM tcIfaceType tys
586 -----------------------------------------
587 tcIfacePredType :: IfacePredType -> IfL PredType
588 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
589 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
590 tcIfacePredType (IfaceEqPred t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (EqPred t1' t2') }
592 -----------------------------------------
593 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
594 tcIfaceCtxt sts = mappM tcIfacePredType sts
598 %************************************************************************
602 %************************************************************************
605 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
606 tcIfaceExpr (IfaceType ty)
607 = tcIfaceType ty `thenM` \ ty' ->
610 tcIfaceExpr (IfaceLcl name)
611 = tcIfaceLclId name `thenM` \ id ->
614 tcIfaceExpr (IfaceExt gbl)
615 = tcIfaceExtId gbl `thenM` \ id ->
618 tcIfaceExpr (IfaceLit lit)
621 tcIfaceExpr (IfaceFCall cc ty)
622 = tcIfaceType ty `thenM` \ ty' ->
623 newUnique `thenM` \ u ->
624 returnM (Var (mkFCallId u cc ty'))
626 tcIfaceExpr (IfaceTuple boxity args)
627 = mappM tcIfaceExpr args `thenM` \ args' ->
629 -- Put the missing type arguments back in
630 con_args = map (Type . exprType) args' ++ args'
632 returnM (mkApps (Var con_id) con_args)
635 con_id = dataConWorkId (tupleCon boxity arity)
638 tcIfaceExpr (IfaceLam bndr body)
639 = bindIfaceBndr bndr $ \ bndr' ->
640 tcIfaceExpr body `thenM` \ body' ->
641 returnM (Lam bndr' body')
643 tcIfaceExpr (IfaceApp fun arg)
644 = tcIfaceExpr fun `thenM` \ fun' ->
645 tcIfaceExpr arg `thenM` \ arg' ->
646 returnM (App fun' arg')
648 tcIfaceExpr (IfaceCase scrut case_bndr ty alts)
649 = tcIfaceExpr scrut `thenM` \ scrut' ->
650 newIfaceName (mkVarOccFS case_bndr) `thenM` \ case_bndr_name ->
652 scrut_ty = exprType scrut'
653 case_bndr' = mkLocalId case_bndr_name scrut_ty
654 tc_app = splitTyConApp scrut_ty
655 -- NB: Won't always succeed (polymoprhic case)
656 -- but won't be demanded in those cases
657 -- NB: not tcSplitTyConApp; we are looking at Core here
658 -- look through non-rec newtypes to find the tycon that
659 -- corresponds to the datacon in this case alternative
661 extendIfaceIdEnv [case_bndr'] $
662 mappM (tcIfaceAlt tc_app) alts `thenM` \ alts' ->
663 tcIfaceType ty `thenM` \ ty' ->
664 returnM (Case scrut' case_bndr' ty' alts')
666 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body)
667 = tcIfaceExpr rhs `thenM` \ rhs' ->
668 bindIfaceId bndr $ \ bndr' ->
669 tcIfaceExpr body `thenM` \ body' ->
670 returnM (Let (NonRec bndr' rhs') body')
672 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
673 = bindIfaceIds bndrs $ \ bndrs' ->
674 mappM tcIfaceExpr rhss `thenM` \ rhss' ->
675 tcIfaceExpr body `thenM` \ body' ->
676 returnM (Let (Rec (bndrs' `zip` rhss')) body')
678 (bndrs, rhss) = unzip pairs
680 tcIfaceExpr (IfaceCast expr co) = do
681 expr' <- tcIfaceExpr expr
682 co' <- tcIfaceType co
683 returnM (Cast expr' co')
685 tcIfaceExpr (IfaceNote note expr)
686 = tcIfaceExpr expr `thenM` \ expr' ->
688 IfaceInlineMe -> returnM (Note InlineMe expr')
689 IfaceSCC cc -> returnM (Note (SCC cc) expr')
690 IfaceCoreNote n -> returnM (Note (CoreNote n) 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 { let tycon_mod = nameModule (tyConName tycon)
708 ; con <- tcIfaceDataCon (ExtPkg tycon_mod data_occ)
709 ; ASSERT2( con `elem` tyConDataCons tycon,
710 ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon) )
711 tcIfaceDataAlt con inst_tys arg_strs rhs }
713 tcIfaceAlt (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
714 = ASSERT( isTupleTyCon tycon )
715 do { let [data_con] = tyConDataCons tycon
716 ; tcIfaceDataAlt data_con inst_tys arg_occs rhs }
718 tcIfaceDataAlt con inst_tys arg_strs rhs
719 = do { us <- newUniqueSupply
720 ; let uniqs = uniqsFromSupply us
721 ; let (ex_tvs, co_tvs, arg_ids)
722 = dataConRepFSInstPat arg_strs uniqs con inst_tys
723 all_tvs = ex_tvs ++ co_tvs
725 ; rhs' <- extendIfaceTyVarEnv all_tvs $
726 extendIfaceIdEnv arg_ids $
728 ; return (DataAlt con, all_tvs ++ arg_ids, rhs') }
733 tcExtCoreBindings :: [IfaceBinding] -> IfL [CoreBind] -- Used for external core
734 tcExtCoreBindings [] = return []
735 tcExtCoreBindings (b:bs) = do_one b (tcExtCoreBindings bs)
737 do_one :: IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
738 do_one (IfaceNonRec bndr rhs) thing_inside
739 = do { rhs' <- tcIfaceExpr rhs
740 ; bndr' <- newExtCoreBndr bndr
741 ; extendIfaceIdEnv [bndr'] $ do
742 { core_binds <- thing_inside
743 ; return (NonRec bndr' rhs' : core_binds) }}
745 do_one (IfaceRec pairs) thing_inside
746 = do { bndrs' <- mappM newExtCoreBndr bndrs
747 ; extendIfaceIdEnv bndrs' $ do
748 { rhss' <- mappM tcIfaceExpr rhss
749 ; core_binds <- thing_inside
750 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
752 (bndrs,rhss) = unzip pairs
756 %************************************************************************
760 %************************************************************************
763 tcIdInfo :: Name -> Type -> IfaceIdInfo -> IfL IdInfo
764 tcIdInfo name ty NoInfo = return vanillaIdInfo
765 tcIdInfo name ty (HasInfo info) = foldlM tcPrag init_info info
767 -- Set the CgInfo to something sensible but uninformative before
768 -- we start; default assumption is that it has CAFs
769 init_info = vanillaIdInfo
771 tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
772 tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
773 tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
775 -- The next two are lazy, so they don't transitively suck stuff in
776 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
777 tcPrag info (HsInline inline_prag) = returnM (info `setInlinePragInfo` inline_prag)
778 tcPrag info (HsUnfold expr)
779 = tcPragExpr name expr `thenM` \ maybe_expr' ->
781 -- maybe_expr' doesn't get looked at if the unfolding
782 -- is never inspected; so the typecheck doesn't even happen
783 unfold_info = case maybe_expr' of
784 Nothing -> noUnfolding
785 Just expr' -> mkTopUnfolding expr'
787 returnM (info `setUnfoldingInfoLazily` unfold_info)
791 tcWorkerInfo ty info wkr arity
792 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId wkr)
794 -- We return without testing maybe_wkr_id, but as soon as info is
795 -- looked at we will test it. That's ok, because its outside the
796 -- knot; and there seems no big reason to further defer the
797 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
798 -- over the unfolding until it's actually used does seem worth while.)
799 ; us <- newUniqueSupply
801 ; returnM (case mb_wkr_id of
803 Just wkr_id -> add_wkr_info us wkr_id info) }
805 doc = text "Worker for" <+> ppr wkr
806 add_wkr_info us wkr_id info
807 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
808 `setWorkerInfo` HasWorker wkr_id arity
810 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
812 -- We are relying here on strictness info always appearing
813 -- before worker info, fingers crossed ....
814 strict_sig = case newStrictnessInfo info of
816 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr)
819 For unfoldings we try to do the job lazily, so that we never type check
820 an unfolding that isn't going to be looked at.
823 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
826 tcIfaceExpr expr `thenM` \ core_expr' ->
828 -- Check for type consistency in the unfolding
829 ifOptM Opt_DoCoreLinting (
830 get_in_scope_ids `thenM` \ in_scope ->
831 case lintUnfolding noSrcLoc in_scope core_expr' of
832 Nothing -> returnM ()
833 Just fail_msg -> pprPanic "Iface Lint failure" (doc <+> fail_msg)
838 doc = text "Unfolding of" <+> ppr name
839 get_in_scope_ids -- Urgh; but just for linting
841 do { env <- getGblEnv
842 ; case if_rec_types env of {
843 Nothing -> return [] ;
844 Just (_, get_env) -> do
845 { type_env <- get_env
846 ; return (typeEnvIds type_env) }}}
851 %************************************************************************
853 Getting from Names to TyThings
855 %************************************************************************
858 tcIfaceGlobal :: Name -> IfL TyThing
860 | Just thing <- wiredInNameTyThing_maybe name
861 -- Wired-in things include TyCons, DataCons, and Ids
862 = do { loadWiredInHomeIface name; return thing }
863 -- Even though we are in an interface file, we want to make
864 -- sure its instances are loaded (imagine f :: Double -> Double)
865 -- and its RULES are loaded too
867 = do { (eps,hpt) <- getEpsAndHpt
869 ; case lookupType dflags hpt (eps_PTE eps) name of {
870 Just thing -> return thing ;
874 ; case if_rec_types env of {
875 Just (mod, get_type_env)
876 | nameIsLocalOrFrom mod name
877 -> do -- It's defined in the module being compiled
878 { type_env <- setLclEnv () get_type_env -- yuk
879 ; case lookupNameEnv type_env name of
880 Just thing -> return thing
881 Nothing -> pprPanic "tcIfaceGlobal (local): not found:"
882 (ppr name $$ ppr type_env) }
886 { mb_thing <- importDecl name -- It's imported; go get it
888 Failed err -> failIfM err
889 Succeeded thing -> return thing
892 tcIfaceTyCon :: IfaceTyCon -> IfL TyCon
893 tcIfaceTyCon IfaceIntTc = tcWiredInTyCon intTyCon
894 tcIfaceTyCon IfaceBoolTc = tcWiredInTyCon boolTyCon
895 tcIfaceTyCon IfaceCharTc = tcWiredInTyCon charTyCon
896 tcIfaceTyCon IfaceListTc = tcWiredInTyCon listTyCon
897 tcIfaceTyCon IfacePArrTc = tcWiredInTyCon parrTyCon
898 tcIfaceTyCon (IfaceTupTc bx ar) = tcWiredInTyCon (tupleTyCon bx ar)
899 tcIfaceTyCon (IfaceTc ext_nm) = do { name <- lookupIfaceExt ext_nm
900 ; thing <- tcIfaceGlobal name
901 ; return (check_tc (tyThingTyCon thing)) }
904 check_tc tc = case toIfaceTyCon (error "urk") tc of
906 other -> pprTrace "check_tc" (ppr tc) tc
910 -- we should be okay just returning Kind constructors without extra loading
911 tcIfaceTyCon IfaceLiftedTypeKindTc = return liftedTypeKindTyCon
912 tcIfaceTyCon IfaceOpenTypeKindTc = return openTypeKindTyCon
913 tcIfaceTyCon IfaceUnliftedTypeKindTc = return unliftedTypeKindTyCon
914 tcIfaceTyCon IfaceArgTypeKindTc = return argTypeKindTyCon
915 tcIfaceTyCon IfaceUbxTupleKindTc = return ubxTupleKindTyCon
917 -- Even though we are in an interface file, we want to make
918 -- sure the instances and RULES of this tycon are loaded
919 -- Imagine: f :: Double -> Double
920 tcWiredInTyCon :: TyCon -> IfL TyCon
921 tcWiredInTyCon tc = do { loadWiredInHomeIface (tyConName tc)
924 tcIfaceClass :: IfaceExtName -> IfL Class
925 tcIfaceClass rdr_name = do { name <- lookupIfaceExt rdr_name
926 ; thing <- tcIfaceGlobal name
927 ; return (tyThingClass thing) }
929 tcIfaceDataCon :: IfaceExtName -> IfL DataCon
930 tcIfaceDataCon gbl = do { name <- lookupIfaceExt gbl
931 ; thing <- tcIfaceGlobal name
933 ADataCon dc -> return dc
934 other -> pprPanic "tcIfaceExtDC" (ppr gbl $$ ppr name$$ ppr thing) }
936 tcIfaceExtId :: IfaceExtName -> IfL Id
937 tcIfaceExtId gbl = do { name <- lookupIfaceExt gbl
938 ; thing <- tcIfaceGlobal name
941 other -> pprPanic "tcIfaceExtId" (ppr gbl $$ ppr name$$ ppr thing) }
944 %************************************************************************
948 %************************************************************************
951 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
952 bindIfaceBndr (IfaceIdBndr bndr) thing_inside
953 = bindIfaceId bndr thing_inside
954 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
955 = bindIfaceTyVar bndr thing_inside
957 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
958 bindIfaceBndrs [] thing_inside = thing_inside []
959 bindIfaceBndrs (b:bs) thing_inside
960 = bindIfaceBndr b $ \ b' ->
961 bindIfaceBndrs bs $ \ bs' ->
962 thing_inside (b':bs')
964 -----------------------
965 bindIfaceId :: IfaceIdBndr -> (Id -> IfL a) -> IfL a
966 bindIfaceId (occ, ty) thing_inside
967 = do { name <- newIfaceName (mkVarOccFS occ)
968 ; ty' <- tcIfaceType ty
969 ; let { id = mkLocalId name ty' }
970 ; extendIfaceIdEnv [id] (thing_inside id) }
972 bindIfaceIds :: [IfaceIdBndr] -> ([Id] -> IfL a) -> IfL a
973 bindIfaceIds bndrs thing_inside
974 = do { names <- newIfaceNames (map mkVarOccFS occs)
975 ; tys' <- mappM tcIfaceType tys
976 ; let { ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys' }
977 ; extendIfaceIdEnv ids (thing_inside ids) }
979 (occs,tys) = unzip bndrs
982 -----------------------
983 newExtCoreBndr :: IfaceIdBndr -> IfL Id
984 newExtCoreBndr (var, ty)
985 = do { mod <- getIfModule
986 ; name <- newGlobalBinder mod (mkVarOccFS var) Nothing noSrcLoc
987 ; ty' <- tcIfaceType ty
988 ; return (mkLocalId name ty') }
990 -----------------------
991 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
992 bindIfaceTyVar (occ,kind) thing_inside
993 = do { name <- newIfaceName (mkTyVarOcc occ)
994 ; tyvar <- mk_iface_tyvar name kind
995 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
997 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
998 bindIfaceTyVars bndrs thing_inside
999 = do { names <- newIfaceNames (map mkTyVarOcc occs)
1000 ; tyvars <- zipWithM mk_iface_tyvar names kinds
1001 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
1003 (occs,kinds) = unzip bndrs
1005 mk_iface_tyvar :: Name -> IfaceKind -> IfL TyVar
1006 mk_iface_tyvar name ifKind = do { kind <- tcIfaceType ifKind
1007 ; return (mkTyVar name kind)