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, buildClass,
23 mkAbstractTyConRhs, mkDataTyConRhs, mkNewTyConRhs )
25 import TcType ( hoistForAllTys ) -- TEMPORARY HACK
26 import Type ( liftedTypeKind, splitTyConApp, mkSynTy, mkTyConApp,
27 mkTyVarTys, ThetaType,
28 mkGenTyConApp ) -- Don't remove this... see mkIfTcApp
29 import TypeRep ( Type(..), PredType(..) )
30 import TyCon ( TyCon, tyConName, isSynTyCon )
31 import HscTypes ( ExternalPackageState(..),
32 TyThing(..), tyThingClass, tyThingTyCon,
33 ModIface(..), ModDetails(..), HomeModInfo(..),
34 emptyModDetails, lookupTypeEnv, lookupType, typeEnvIds )
35 import InstEnv ( Instance(..), mkImportedInstance )
37 import CoreUtils ( exprType )
39 import CoreLint ( lintUnfolding )
40 import WorkWrap ( mkWrapper )
41 import Id ( Id, mkVanillaGlobal, mkLocalId )
42 import MkId ( mkFCallId )
43 import IdInfo ( IdInfo, CafInfo(..), WorkerInfo(..),
44 setUnfoldingInfoLazily, setAllStrictnessInfo, setWorkerInfo,
45 setArityInfo, setInlinePragInfo, setCafInfo,
46 vanillaIdInfo, newStrictnessInfo )
47 import Class ( Class )
48 import TyCon ( tyConDataCons, isTupleTyCon, mkForeignTyCon )
49 import DataCon ( DataCon, dataConWorkId, dataConTyVars, dataConInstArgTys, isVanillaDataCon )
50 import TysWiredIn ( tupleCon, tupleTyCon, listTyCon, intTyCon, boolTyCon, charTyCon, parrTyCon )
51 import Var ( TyVar, mkTyVar, tyVarKind )
52 import Name ( Name, nameModule, nameIsLocalOrFrom, isWiredInName,
53 wiredInNameTyThing_maybe, nameParent )
55 import OccName ( OccName )
56 import Module ( Module, lookupModuleEnv )
57 import UniqSupply ( initUs_ )
59 import ErrUtils ( Message )
60 import Maybes ( MaybeErr(..) )
61 import SrcLoc ( noSrcLoc )
62 import Util ( zipWithEqual, dropList, equalLength )
63 import DynFlags ( DynFlag(..), isOneShot )
72 An IfaceDecl is populated with RdrNames, and these are not renamed to
73 Names before typechecking, because there should be no scope errors etc.
75 -- For (b) consider: f = $(...h....)
76 -- where h is imported, and calls f via an hi-boot file.
77 -- This is bad! But it is not seen as a staging error, because h
78 -- is indeed imported. We don't want the type-checker to black-hole
79 -- when simplifying and compiling the splice!
81 -- Simple solution: discard any unfolding that mentions a variable
82 -- bound in this module (and hence not yet processed).
83 -- The discarding happens when forkM finds a type error.
85 %************************************************************************
87 %* tcImportDecl is the key function for "faulting in" *
90 %************************************************************************
92 The main idea is this. We are chugging along type-checking source code, and
93 find a reference to GHC.Base.map. We call tcLookupGlobal, which doesn't find
94 it in the EPS type envt. So it
96 2 gets the decl for GHC.Base.map
97 3 typechecks it via tcIfaceDecl
98 4 and adds it to the type env in the EPS
100 Note that DURING STEP 4, we may find that map's type mentions a type
101 constructor that also
103 Notice that for imported things we read the current version from the EPS
104 mutable variable. This is important in situations like
106 where the code that e1 expands to might import some defns that
107 also turn out to be needed by the code that e2 expands to.
110 tcImportDecl :: Name -> TcM TyThing
111 -- Entry point for *source-code* uses of importDecl
113 | Just thing <- wiredInNameTyThing_maybe name
114 = do { initIfaceTcRn (loadWiredInHomeIface name)
117 = do { traceIf (text "tcImportDecl" <+> ppr name)
118 ; mb_thing <- initIfaceTcRn (importDecl name)
120 Succeeded thing -> return thing
121 Failed err -> failWithTc err }
123 checkWiredInTyCon :: TyCon -> TcM ()
124 -- Ensure that the home module of the TyCon (and hence its instances)
125 -- are loaded. It might not be a wired-in tycon (see the calls in TcUnify),
126 -- in which case this is a no-op.
128 | not (isWiredInName tc_name)
131 = do { mod <- getModule
132 ; if nameIsLocalOrFrom mod tc_name then
133 -- Don't look for (non-existent) Float.hi when
134 -- compiling Float.lhs, which mentions Float of course
136 else -- A bit yukky to call initIfaceTcRn here
137 initIfaceTcRn (loadWiredInHomeIface tc_name)
140 tc_name = tyConName tc
142 importDecl :: Name -> IfM lcl (MaybeErr Message TyThing)
143 -- Get the TyThing for this Name from an interface file
144 -- It's not a wired-in thing -- the caller caught that
146 = ASSERT( not (isWiredInName name) )
149 -- Load the interface, which should populate the PTE
150 ; mb_iface <- loadInterface nd_doc (nameModule name) ImportBySystem
152 Failed err_msg -> return (Failed err_msg) ;
153 Succeeded iface -> do
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") <+> ppr (nameParent name))
164 2 (vcat [ptext SLIT("Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
165 ptext SLIT("Use -ddump-if-trace to get an idea of which file caused the error")])
168 %************************************************************************
170 Type-checking a complete interface
172 %************************************************************************
174 Suppose we discover we don't need to recompile. Then we must type
175 check the old interface file. This is a bit different to the
176 incremental type checking we do as we suck in interface files. Instead
177 we do things similarly as when we are typechecking source decls: we
178 bring into scope the type envt for the interface all at once, using a
179 knot. Remember, the decls aren't necessarily in dependency order --
180 and even if they were, the type decls might be mutually recursive.
183 typecheckIface :: ModIface -- Get the decls from here
184 -> TcRnIf gbl lcl ModDetails
186 = initIfaceTc iface $ \ tc_env_var -> do
187 -- The tc_env_var is freshly allocated, private to
188 -- type-checking this particular interface
189 { -- Get the right set of decls and rules. If we are compiling without -O
190 -- we discard pragmas before typechecking, so that we don't "see"
191 -- information that we shouldn't. From a versioning point of view
192 -- It's not actually *wrong* to do so, but in fact GHCi is unable
193 -- to handle unboxed tuples, so it must not see unfoldings.
194 ignore_prags <- doptM Opt_IgnoreInterfacePragmas
196 -- Load & typecheck the decls
197 ; decl_things <- loadDecls ignore_prags (mi_decls iface)
199 ; let type_env = mkNameEnv decl_things
200 ; writeMutVar tc_env_var type_env
202 -- Now do those rules and instances
203 ; let { rules | ignore_prags = []
204 | otherwise = mi_rules iface
205 ; dfuns = mi_insts iface
207 ; dfuns <- mapM tcIfaceInst dfuns
208 ; rules <- mapM tcIfaceRule rules
211 ; exports <- ifaceExportNames (mi_exports iface)
214 ; return (ModDetails { md_types = type_env,
217 md_exports = exports })
222 %************************************************************************
224 Type and class declarations
226 %************************************************************************
229 tcHiBootIface :: Module -> TcRn ModDetails
230 -- Load the hi-boot iface for the module being compiled,
231 -- if it indeed exists in the transitive closure of imports
232 -- Return the ModDetails, empty if no hi-boot iface
234 = do { traceIf (text "loadHiBootInterface" <+> ppr mod)
236 ; mode <- getGhciMode
237 ; if not (isOneShot mode)
238 -- In --make and interactive mode, if this module has an hs-boot file
239 -- we'll have compiled it already, and it'll be in the HPT
241 -- We check wheher the interface is a *boot* interface.
242 -- It can happen (when using GHC from Visual Studio) that we
243 -- compile a module in TypecheckOnly mode, with a stable,
244 -- fully-populated HPT. In that case the boot interface isn't there
245 -- (it's been replaced by the mother module) so we can't check it.
246 -- And that's fine, because if M's ModInfo is in the HPT, then
247 -- it's been compiled once, and we don't need to check the boot iface
248 then do { hpt <- getHpt
249 ; case lookupModuleEnv hpt mod of
250 Just info | mi_boot (hm_iface info)
251 -> return (hm_details info)
252 other -> return emptyModDetails }
255 -- OK, so we're in one-shot mode.
256 -- In that case, we're read all the direct imports by now,
257 -- so eps_is_boot will record if any of our imports mention us by
258 -- way of hi-boot file
260 ; case lookupModuleEnv (eps_is_boot eps) mod of {
261 Nothing -> return emptyModDetails ; -- The typical case
263 Just (_, False) -> failWithTc moduleLoop ;
264 -- Someone below us imported us!
265 -- This is a loop with no hi-boot in the way
267 Just (mod, True) -> -- There's a hi-boot interface below us
269 do { read_result <- findAndReadIface
270 True -- Explicit import?
274 ; case read_result of
275 Failed err -> failWithTc (elaborate err)
276 Succeeded (iface, _path) -> typecheckIface iface
279 need = ptext SLIT("Need the hi-boot interface for") <+> ppr mod
280 <+> ptext SLIT("to compare against the Real Thing")
282 moduleLoop = ptext SLIT("Circular imports: module") <+> quotes (ppr mod)
283 <+> ptext SLIT("depends on itself")
285 elaborate err = hang (ptext SLIT("Could not find hi-boot interface for") <+>
286 quotes (ppr mod) <> colon) 4 err
290 %************************************************************************
292 Type and class declarations
294 %************************************************************************
296 When typechecking a data type decl, we *lazily* (via forkM) typecheck
297 the constructor argument types. This is in the hope that we may never
298 poke on those argument types, and hence may never need to load the
299 interface files for types mentioned in the arg types.
302 data Foo.S = MkS Baz.T
303 Mabye we can get away without even loading the interface for Baz!
305 This is not just a performance thing. Suppose we have
306 data Foo.S = MkS Baz.T
307 data Baz.T = MkT Foo.S
308 (in different interface files, of course).
309 Now, first we load and typecheck Foo.S, and add it to the type envt.
310 If we do explore MkS's argument, we'll load and typecheck Baz.T.
311 If we explore MkT's argument we'll find Foo.S already in the envt.
313 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
314 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
315 which isn't done yet.
317 All very cunning. However, there is a rather subtle gotcha which bit
318 me when developing this stuff. When we typecheck the decl for S, we
319 extend the type envt with S, MkS, and all its implicit Ids. Suppose
320 (a bug, but it happened) that the list of implicit Ids depended in
321 turn on the constructor arg types. Then the following sequence of
323 * we build a thunk <t> for the constructor arg tys
324 * we build a thunk for the extended type environment (depends on <t>)
325 * we write the extended type envt into the global EPS mutvar
327 Now we look something up in the type envt
329 * which reads the global type envt out of the global EPS mutvar
330 * but that depends in turn on <t>
332 It's subtle, because, it'd work fine if we typechecked the constructor args
333 eagerly -- they don't need the extended type envt. They just get the extended
334 type envt by accident, because they look at it later.
336 What this means is that the implicitTyThings MUST NOT DEPEND on any of
341 tcIfaceDecl :: IfaceDecl -> IfL TyThing
343 tcIfaceDecl (IfaceId {ifName = occ_name, ifType = iface_type, ifIdInfo = info})
344 = do { name <- lookupIfaceTop occ_name
345 ; ty <- tcIfaceType iface_type
346 ; info <- tcIdInfo name ty info
347 ; return (AnId (mkVanillaGlobal name ty info)) }
349 tcIfaceDecl (IfaceData {ifName = occ_name,
353 ifVrcs = arg_vrcs, ifRec = is_rec,
354 ifGeneric = want_generic })
355 = do { tc_name <- lookupIfaceTop occ_name
356 ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
358 { tycon <- fixM ( \ tycon -> do
359 { stupid_theta <- tcIfaceCtxt ctxt
360 ; cons <- tcIfaceDataCons tycon tyvars rdr_cons
361 ; buildAlgTyCon tc_name tyvars stupid_theta
362 cons arg_vrcs is_rec want_generic
364 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
365 ; return (ATyCon tycon)
368 tcIfaceDecl (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
369 ifSynRhs = rdr_rhs_ty, ifVrcs = arg_vrcs})
370 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
371 { tc_name <- lookupIfaceTop occ_name
372 ; rhs_ty <- tcIfaceType rdr_rhs_ty
373 ; return (ATyCon (buildSynTyCon tc_name tyvars rhs_ty arg_vrcs))
376 tcIfaceDecl (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name, ifTyVars = tv_bndrs,
377 ifFDs = rdr_fds, ifSigs = rdr_sigs,
378 ifVrcs = tc_vrcs, ifRec = tc_isrec })
379 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
380 { cls_name <- lookupIfaceTop occ_name
381 ; ctxt <- tcIfaceCtxt rdr_ctxt
382 ; sigs <- mappM tc_sig rdr_sigs
383 ; fds <- mappM tc_fd rdr_fds
384 ; cls <- buildClass cls_name tyvars ctxt fds sigs tc_isrec tc_vrcs
385 ; return (AClass cls) }
387 tc_sig (IfaceClassOp occ dm rdr_ty)
388 = do { op_name <- lookupIfaceTop occ
389 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
390 -- Must be done lazily for just the same reason as the
391 -- context of a data decl: the type sig might mention the
392 -- class being defined
393 ; return (op_name, dm, op_ty) }
395 mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
397 tc_fd (tvs1, tvs2) = do { tvs1' <- mappM tcIfaceTyVar tvs1
398 ; tvs2' <- mappM tcIfaceTyVar tvs2
399 ; return (tvs1', tvs2') }
401 tcIfaceDecl (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
402 = do { name <- lookupIfaceTop rdr_name
403 ; return (ATyCon (mkForeignTyCon name ext_name
404 liftedTypeKind 0 [])) }
406 tcIfaceDataCons tycon tc_tyvars if_cons
408 IfAbstractTyCon -> return mkAbstractTyConRhs
409 IfDataTyCon cons -> do { data_cons <- mappM tc_con_decl cons
410 ; return (mkDataTyConRhs data_cons) }
411 IfNewTyCon con -> do { data_con <- tc_con_decl con
412 ; return (mkNewTyConRhs tycon data_con) }
414 tc_con_decl (IfVanillaCon { ifConOcc = occ, ifConInfix = is_infix, ifConArgTys = args,
415 ifConStricts = stricts, ifConFields = field_lbls})
416 = do { name <- lookupIfaceTop occ
417 -- Read the argument types, but lazily to avoid faulting in
418 -- the component types unless they are really needed
419 ; arg_tys <- forkM (mk_doc name) (mappM tcIfaceType args)
420 ; lbl_names <- mappM lookupIfaceTop field_lbls
421 ; buildDataCon name is_infix True {- Vanilla -}
423 tc_tyvars [] arg_tys tycon
424 (mkTyVarTys tc_tyvars) -- Vanilla => we know result tys
427 tc_con_decl (IfGadtCon { ifConTyVars = con_tvs,
428 ifConOcc = occ, ifConCtxt = ctxt,
429 ifConArgTys = args, ifConResTys = ress,
430 ifConStricts = stricts})
431 = bindIfaceTyVars con_tvs $ \ con_tyvars -> do
432 { name <- lookupIfaceTop occ
433 ; theta <- tcIfaceCtxt ctxt -- Laziness seems not worth the bother here
434 -- At one stage I thought that this context checking *had*
435 -- to be lazy, because of possible mutual recursion between the
436 -- type and the classe:
438 -- class Real a where { toRat :: a -> Ratio Integer }
439 -- data (Real a) => Ratio a = ...
440 -- But now I think that the laziness in checking class ops breaks
441 -- the loop, so no laziness needed
443 -- Read the argument types, but lazily to avoid faulting in
444 -- the component types unless they are really needed
445 ; arg_tys <- forkM (mk_doc name) (mappM tcIfaceType args)
446 ; res_tys <- forkM (mk_doc name) (mappM tcIfaceType ress)
448 ; buildDataCon name False {- Not infix -} False {- Not vanilla -}
449 stricts [{- No fields -}]
451 arg_tys tycon res_tys
453 mk_doc con_name = ptext SLIT("Constructor") <+> ppr con_name
457 %************************************************************************
461 %************************************************************************
464 tcIfaceInst :: IfaceInst -> IfL Instance
465 tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
466 ifInstCls = cls, ifInstTys = mb_tcs,
468 = do { dfun <- forkM (ptext SLIT("Dict fun") <+> ppr dfun_occ) $
469 tcIfaceExtId (LocalTop dfun_occ)
470 ; cls' <- lookupIfaceExt cls
471 ; mb_tcs' <- mapM do_tc mb_tcs
472 ; return (mkImportedInstance cls' mb_tcs' orph dfun oflag) }
474 do_tc Nothing = return Nothing
475 do_tc (Just tc) = do { tc' <- lookupIfaceTc tc; return (Just tc') }
479 %************************************************************************
483 %************************************************************************
485 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
486 are in the type environment. However, remember that typechecking a Rule may
487 (as a side effect) augment the type envt, and so we may need to iterate the process.
490 tcIfaceRule :: IfaceRule -> IfL CoreRule
491 tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,
492 ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs,
494 = do { fn' <- lookupIfaceExt fn
495 ; ~(bndrs', args', rhs') <-
496 -- Typecheck the payload lazily, in the hope it'll never be looked at
497 forkM (ptext SLIT("Rule") <+> ftext name) $
498 bindIfaceBndrs bndrs $ \ bndrs' ->
499 do { args' <- mappM tcIfaceExpr args
500 ; rhs' <- tcIfaceExpr rhs
501 ; return (bndrs', args', rhs') }
502 ; mb_tcs <- mapM ifTopFreeName args
503 ; returnM (Rule { ru_name = name, ru_fn = fn', ru_act = act,
504 ru_bndrs = bndrs', ru_args = args',
505 ru_rhs = rhs', ru_orph = orph,
507 ru_local = isLocalIfaceExtName fn }) }
509 -- This function *must* mirror exactly what Rules.topFreeName does
510 -- We could have stored the ru_rough field in the iface file
511 -- but that would be redundant, I think.
512 -- The only wrinkle is that we must not be deceived by
513 -- type syononyms at the top of a type arg. Since
514 -- we can't tell at this point, we are careful not
515 -- to write them out in coreRuleToIfaceRule
516 ifTopFreeName :: IfaceExpr -> IfL (Maybe Name)
517 ifTopFreeName (IfaceType (IfaceTyConApp tc _ ))
518 = do { n <- lookupIfaceTc tc
520 ifTopFreeName (IfaceApp f a) = ifTopFreeName f
521 ifTopFreeName (IfaceExt ext) = do { n <- lookupIfaceExt ext
523 ifTopFreeName other = return Nothing
527 %************************************************************************
531 %************************************************************************
534 tcIfaceType :: IfaceType -> IfL Type
535 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
536 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
537 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
538 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkIfTcApp tc' ts') }
539 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
540 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
542 tcIfaceTypes tys = mapM tcIfaceType tys
544 mkIfTcApp :: TyCon -> [Type] -> Type
545 -- In interface files we retain type synonyms (for brevity and better error
546 -- messages), but type synonyms can expand into non-hoisted types (ones with
547 -- foralls to the right of an arrow), so we must be careful to hoist them here.
548 -- This hack should go away when we get rid of hoisting.
549 -- Then we should go back to mkGenTyConApp or something like it
551 -- Nov 05: the type is now hoisted before being put into an interface file
552 mkIfTcApp tc tys = mkTyConApp tc tys
553 -- | isSynTyCon tc = hoistForAllTys (mkSynTy tc tys)
554 -- | otherwise = mkTyConApp tc tys
556 -----------------------------------------
557 tcIfacePredType :: IfacePredType -> IfL PredType
558 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
559 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
561 -----------------------------------------
562 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
563 tcIfaceCtxt sts = mappM tcIfacePredType sts
567 %************************************************************************
571 %************************************************************************
574 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
575 tcIfaceExpr (IfaceType ty)
576 = tcIfaceType ty `thenM` \ ty' ->
579 tcIfaceExpr (IfaceLcl name)
580 = tcIfaceLclId name `thenM` \ id ->
583 tcIfaceExpr (IfaceExt gbl)
584 = tcIfaceExtId gbl `thenM` \ id ->
587 tcIfaceExpr (IfaceLit lit)
590 tcIfaceExpr (IfaceFCall cc ty)
591 = tcIfaceType ty `thenM` \ ty' ->
592 newUnique `thenM` \ u ->
593 returnM (Var (mkFCallId u cc ty'))
595 tcIfaceExpr (IfaceTuple boxity args)
596 = mappM tcIfaceExpr args `thenM` \ args' ->
598 -- Put the missing type arguments back in
599 con_args = map (Type . exprType) args' ++ args'
601 returnM (mkApps (Var con_id) con_args)
604 con_id = dataConWorkId (tupleCon boxity arity)
607 tcIfaceExpr (IfaceLam bndr body)
608 = bindIfaceBndr bndr $ \ bndr' ->
609 tcIfaceExpr body `thenM` \ body' ->
610 returnM (Lam bndr' body')
612 tcIfaceExpr (IfaceApp fun arg)
613 = tcIfaceExpr fun `thenM` \ fun' ->
614 tcIfaceExpr arg `thenM` \ arg' ->
615 returnM (App fun' arg')
617 tcIfaceExpr (IfaceCase scrut case_bndr ty alts)
618 = tcIfaceExpr scrut `thenM` \ scrut' ->
619 newIfaceName case_bndr `thenM` \ case_bndr_name ->
621 scrut_ty = exprType scrut'
622 case_bndr' = mkLocalId case_bndr_name scrut_ty
623 tc_app = splitTyConApp scrut_ty
624 -- NB: Won't always succeed (polymoprhic case)
625 -- but won't be demanded in those cases
626 -- NB: not tcSplitTyConApp; we are looking at Core here
627 -- look through non-rec newtypes to find the tycon that
628 -- corresponds to the datacon in this case alternative
630 extendIfaceIdEnv [case_bndr'] $
631 mappM (tcIfaceAlt tc_app) alts `thenM` \ alts' ->
632 tcIfaceType ty `thenM` \ ty' ->
633 returnM (Case scrut' case_bndr' ty' alts')
635 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body)
636 = tcIfaceExpr rhs `thenM` \ rhs' ->
637 bindIfaceId bndr $ \ bndr' ->
638 tcIfaceExpr body `thenM` \ body' ->
639 returnM (Let (NonRec bndr' rhs') body')
641 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
642 = bindIfaceIds bndrs $ \ bndrs' ->
643 mappM tcIfaceExpr rhss `thenM` \ rhss' ->
644 tcIfaceExpr body `thenM` \ body' ->
645 returnM (Let (Rec (bndrs' `zip` rhss')) body')
647 (bndrs, rhss) = unzip pairs
649 tcIfaceExpr (IfaceNote note expr)
650 = tcIfaceExpr expr `thenM` \ expr' ->
652 IfaceCoerce to_ty -> tcIfaceType to_ty `thenM` \ to_ty' ->
653 returnM (Note (Coerce to_ty'
654 (exprType expr')) expr')
655 IfaceInlineCall -> returnM (Note InlineCall expr')
656 IfaceInlineMe -> returnM (Note InlineMe expr')
657 IfaceSCC cc -> returnM (Note (SCC cc) expr')
658 IfaceCoreNote n -> returnM (Note (CoreNote n) expr')
660 -------------------------
661 tcIfaceAlt _ (IfaceDefault, names, rhs)
662 = ASSERT( null names )
663 tcIfaceExpr rhs `thenM` \ rhs' ->
664 returnM (DEFAULT, [], rhs')
666 tcIfaceAlt _ (IfaceLitAlt lit, names, rhs)
667 = ASSERT( null names )
668 tcIfaceExpr rhs `thenM` \ rhs' ->
669 returnM (LitAlt lit, [], rhs')
671 -- A case alternative is made quite a bit more complicated
672 -- by the fact that we omit type annotations because we can
673 -- work them out. True enough, but its not that easy!
674 tcIfaceAlt (tycon, inst_tys) (IfaceDataAlt data_occ, arg_occs, rhs)
675 = do { let tycon_mod = nameModule (tyConName tycon)
676 ; con <- tcIfaceDataCon (ExtPkg tycon_mod data_occ)
677 ; ASSERT2( con `elem` tyConDataCons tycon,
678 ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon) )
680 if isVanillaDataCon con then
681 tcVanillaAlt con inst_tys arg_occs rhs
684 arg_names <- newIfaceNames arg_occs
685 ; let tyvars = [ mkTyVar name (tyVarKind tv)
686 | (name,tv) <- arg_names `zip` dataConTyVars con]
687 arg_tys = dataConInstArgTys con (mkTyVarTys tyvars)
688 id_names = dropList tyvars arg_names
689 arg_ids = ASSERT2( equalLength id_names arg_tys,
690 ppr (con, arg_names, rhs) $$ ppr tyvars $$ ppr arg_tys )
691 zipWith mkLocalId id_names arg_tys
693 ; rhs' <- extendIfaceTyVarEnv tyvars $
694 extendIfaceIdEnv arg_ids $
696 ; return (DataAlt con, tyvars ++ arg_ids, rhs') }}
698 tcIfaceAlt (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
699 = ASSERT( isTupleTyCon tycon )
700 do { let [data_con] = tyConDataCons tycon
701 ; tcVanillaAlt data_con inst_tys arg_occs rhs }
703 tcVanillaAlt data_con inst_tys arg_occs rhs
704 = do { arg_names <- newIfaceNames arg_occs
705 ; let arg_tys = dataConInstArgTys data_con inst_tys
706 ; let arg_ids = ASSERT2( equalLength arg_names arg_tys,
707 ppr data_con <+> ppr inst_tys <+> ppr arg_occs $$ ppr rhs )
708 zipWith mkLocalId arg_names arg_tys
709 ; rhs' <- extendIfaceIdEnv arg_ids (tcIfaceExpr rhs)
710 ; returnM (DataAlt data_con, arg_ids, rhs') }
715 tcExtCoreBindings :: [IfaceBinding] -> IfL [CoreBind] -- Used for external core
716 tcExtCoreBindings [] = return []
717 tcExtCoreBindings (b:bs) = do_one b (tcExtCoreBindings bs)
719 do_one :: IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
720 do_one (IfaceNonRec bndr rhs) thing_inside
721 = do { rhs' <- tcIfaceExpr rhs
722 ; bndr' <- newExtCoreBndr bndr
723 ; extendIfaceIdEnv [bndr'] $ do
724 { core_binds <- thing_inside
725 ; return (NonRec bndr' rhs' : core_binds) }}
727 do_one (IfaceRec pairs) thing_inside
728 = do { bndrs' <- mappM newExtCoreBndr bndrs
729 ; extendIfaceIdEnv bndrs' $ do
730 { rhss' <- mappM tcIfaceExpr rhss
731 ; core_binds <- thing_inside
732 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
734 (bndrs,rhss) = unzip pairs
738 %************************************************************************
742 %************************************************************************
745 tcIdInfo :: Name -> Type -> IfaceIdInfo -> IfL IdInfo
746 tcIdInfo name ty NoInfo = return vanillaIdInfo
747 tcIdInfo name ty (HasInfo info) = foldlM tcPrag init_info info
749 -- Set the CgInfo to something sensible but uninformative before
750 -- we start; default assumption is that it has CAFs
751 init_info = vanillaIdInfo
753 tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
754 tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
755 tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
757 -- The next two are lazy, so they don't transitively suck stuff in
758 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
759 tcPrag info (HsUnfold inline_prag expr)
760 = tcPragExpr name expr `thenM` \ maybe_expr' ->
762 -- maybe_expr' doesn't get looked at if the unfolding
763 -- is never inspected; so the typecheck doesn't even happen
764 unfold_info = case maybe_expr' of
765 Nothing -> noUnfolding
766 Just expr' -> mkTopUnfolding expr'
768 returnM (info `setUnfoldingInfoLazily` unfold_info
769 `setInlinePragInfo` inline_prag)
773 tcWorkerInfo ty info wkr arity
774 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId wkr)
776 -- We return without testing maybe_wkr_id, but as soon as info is
777 -- looked at we will test it. That's ok, because its outside the
778 -- knot; and there seems no big reason to further defer the
779 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
780 -- over the unfolding until it's actually used does seem worth while.)
781 ; us <- newUniqueSupply
783 ; returnM (case mb_wkr_id of
785 Just wkr_id -> add_wkr_info us wkr_id info) }
787 doc = text "Worker for" <+> ppr wkr
788 add_wkr_info us wkr_id info
789 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
790 `setWorkerInfo` HasWorker wkr_id arity
792 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
794 -- We are relying here on strictness info always appearing
795 -- before worker info, fingers crossed ....
796 strict_sig = case newStrictnessInfo info of
798 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr)
801 For unfoldings we try to do the job lazily, so that we never type check
802 an unfolding that isn't going to be looked at.
805 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
808 tcIfaceExpr expr `thenM` \ core_expr' ->
810 -- Check for type consistency in the unfolding
811 ifOptM Opt_DoCoreLinting (
812 get_in_scope_ids `thenM` \ in_scope ->
813 case lintUnfolding noSrcLoc in_scope core_expr' of
814 Nothing -> returnM ()
815 Just fail_msg -> pprPanic "Iface Lint failure" (doc <+> fail_msg)
820 doc = text "Unfolding of" <+> ppr name
821 get_in_scope_ids -- Urgh; but just for linting
823 do { env <- getGblEnv
824 ; case if_rec_types env of {
825 Nothing -> return [] ;
826 Just (_, get_env) -> do
827 { type_env <- get_env
828 ; return (typeEnvIds type_env) }}}
833 %************************************************************************
835 Getting from Names to TyThings
837 %************************************************************************
840 tcIfaceGlobal :: Name -> IfL TyThing
842 | Just thing <- wiredInNameTyThing_maybe name
843 -- Wired-in things include TyCons, DataCons, and Ids
844 = do { loadWiredInHomeIface name; return thing }
845 -- Even though we are in an interface file, we want to make
846 -- sure its instances are loaded (imagine f :: Double -> Double)
847 -- and its RULES are loaded too
849 = do { (eps,hpt) <- getEpsAndHpt
850 ; case lookupType hpt (eps_PTE eps) name of {
851 Just thing -> return thing ;
855 ; case if_rec_types env of {
856 Just (mod, get_type_env)
857 | nameIsLocalOrFrom mod name
858 -> do -- It's defined in the module being compiled
859 { type_env <- setLclEnv () get_type_env -- yuk
860 ; case lookupNameEnv type_env name of
861 Just thing -> return thing
862 Nothing -> pprPanic "tcIfaceGlobal (local): not found:"
863 (ppr name $$ ppr type_env) }
867 { mb_thing <- importDecl name -- It's imported; go get it
869 Failed err -> failIfM err
870 Succeeded thing -> return thing
873 tcIfaceTyCon :: IfaceTyCon -> IfL TyCon
874 tcIfaceTyCon IfaceIntTc = tcWiredInTyCon intTyCon
875 tcIfaceTyCon IfaceBoolTc = tcWiredInTyCon boolTyCon
876 tcIfaceTyCon IfaceCharTc = tcWiredInTyCon charTyCon
877 tcIfaceTyCon IfaceListTc = tcWiredInTyCon listTyCon
878 tcIfaceTyCon IfacePArrTc = tcWiredInTyCon parrTyCon
879 tcIfaceTyCon (IfaceTupTc bx ar) = tcWiredInTyCon (tupleTyCon bx ar)
880 tcIfaceTyCon (IfaceTc ext_nm) = do { name <- lookupIfaceExt ext_nm
881 ; thing <- tcIfaceGlobal name
882 ; return (check_tc (tyThingTyCon thing)) }
885 check_tc tc = case toIfaceTyCon (error "urk") tc of
887 other -> pprTrace "check_tc" (ppr tc) tc
892 -- Even though we are in an interface file, we want to make
893 -- sure the instances and RULES of this tycon are loaded
894 -- Imagine: f :: Double -> Double
895 tcWiredInTyCon :: TyCon -> IfL TyCon
896 tcWiredInTyCon tc = do { loadWiredInHomeIface (tyConName tc)
899 tcIfaceClass :: IfaceExtName -> IfL Class
900 tcIfaceClass rdr_name = do { name <- lookupIfaceExt rdr_name
901 ; thing <- tcIfaceGlobal name
902 ; return (tyThingClass thing) }
904 tcIfaceDataCon :: IfaceExtName -> IfL DataCon
905 tcIfaceDataCon gbl = do { name <- lookupIfaceExt gbl
906 ; thing <- tcIfaceGlobal name
908 ADataCon dc -> return dc
909 other -> pprPanic "tcIfaceExtDC" (ppr gbl $$ ppr name$$ ppr thing) }
911 tcIfaceExtId :: IfaceExtName -> IfL Id
912 tcIfaceExtId gbl = do { name <- lookupIfaceExt gbl
913 ; thing <- tcIfaceGlobal name
916 other -> pprPanic "tcIfaceExtId" (ppr gbl $$ ppr name$$ ppr thing) }
919 %************************************************************************
923 %************************************************************************
926 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
927 bindIfaceBndr (IfaceIdBndr bndr) thing_inside
928 = bindIfaceId bndr thing_inside
929 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
930 = bindIfaceTyVar bndr thing_inside
932 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
933 bindIfaceBndrs [] thing_inside = thing_inside []
934 bindIfaceBndrs (b:bs) thing_inside
935 = bindIfaceBndr b $ \ b' ->
936 bindIfaceBndrs bs $ \ bs' ->
937 thing_inside (b':bs')
939 -----------------------
940 bindIfaceId :: (OccName, IfaceType) -> (Id -> IfL a) -> IfL a
941 bindIfaceId (occ, ty) thing_inside
942 = do { name <- newIfaceName occ
943 ; ty' <- tcIfaceType ty
944 ; let { id = mkLocalId name ty' }
945 ; extendIfaceIdEnv [id] (thing_inside id) }
947 bindIfaceIds :: [(OccName, IfaceType)] -> ([Id] -> IfL a) -> IfL a
948 bindIfaceIds bndrs thing_inside
949 = do { names <- newIfaceNames occs
950 ; tys' <- mappM tcIfaceType tys
951 ; let { ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys' }
952 ; extendIfaceIdEnv ids (thing_inside ids) }
954 (occs,tys) = unzip bndrs
957 -----------------------
958 newExtCoreBndr :: (OccName, IfaceType) -> IfL Id
959 newExtCoreBndr (occ, ty)
960 = do { mod <- getIfModule
961 ; name <- newGlobalBinder mod occ Nothing noSrcLoc
962 ; ty' <- tcIfaceType ty
963 ; return (mkLocalId name ty') }
965 -----------------------
966 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
967 bindIfaceTyVar (occ,kind) thing_inside
968 = do { name <- newIfaceName occ
969 ; let tyvar = mk_iface_tyvar name kind
970 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
972 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
973 bindIfaceTyVars bndrs thing_inside
974 = do { names <- newIfaceNames occs
975 ; let tyvars = zipWith mk_iface_tyvar names kinds
976 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
978 (occs,kinds) = unzip bndrs
980 mk_iface_tyvar name kind = mkTyVar name kind