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, refineIfaceIdEnv,
21 newIfaceName, newIfaceNames, ifaceExportNames )
22 import BuildTyCl ( buildSynTyCon, buildAlgTyCon, buildDataCon, buildClass,
23 mkAbstractTyConRhs, mkDataTyConRhs, mkNewTyConRhs )
25 import Type ( liftedTypeKind, splitTyConApp, mkTyConApp,
26 mkTyVarTys, ThetaType )
27 import TypeRep ( Type(..), PredType(..) )
28 import TyCon ( TyCon, tyConName )
29 import HscTypes ( ExternalPackageState(..),
30 TyThing(..), tyThingClass, tyThingTyCon,
31 ModIface(..), ModDetails(..), HomeModInfo(..),
32 emptyModDetails, lookupTypeEnv, lookupType, typeEnvIds )
33 import InstEnv ( Instance(..), mkImportedInstance )
34 import Unify ( coreRefineTys )
36 import CoreUtils ( exprType )
38 import CoreLint ( lintUnfolding )
39 import WorkWrap ( mkWrapper )
40 import Id ( Id, mkVanillaGlobal, mkLocalId )
41 import MkId ( mkFCallId )
42 import IdInfo ( IdInfo, CafInfo(..), WorkerInfo(..),
43 setUnfoldingInfoLazily, setAllStrictnessInfo, setWorkerInfo,
44 setArityInfo, setInlinePragInfo, setCafInfo,
45 vanillaIdInfo, newStrictnessInfo )
46 import Class ( Class )
47 import TyCon ( tyConDataCons, isTupleTyCon, mkForeignTyCon )
48 import DataCon ( DataCon, dataConWorkId, dataConTyVars, dataConInstArgTys, isVanillaDataCon )
49 import TysWiredIn ( tupleCon, tupleTyCon, listTyCon, intTyCon, boolTyCon, charTyCon, parrTyCon )
50 import Var ( TyVar, mkTyVar, tyVarKind )
51 import Name ( Name, nameModule, nameIsLocalOrFrom, isWiredInName,
52 wiredInNameTyThing_maybe, nameParent )
54 import OccName ( OccName, mkVarOccFS, mkTyVarOcc )
55 import FastString ( FastString )
56 import Module ( Module, moduleName )
57 import UniqFM ( lookupUFM )
58 import UniqSupply ( initUs_ )
60 import ErrUtils ( Message )
61 import Maybes ( MaybeErr(..) )
62 import SrcLoc ( noSrcLoc )
63 import Util ( zipWithEqual, equalLength, splitAtList )
64 import DynFlags ( DynFlag(..), isOneShot )
73 An IfaceDecl is populated with RdrNames, and these are not renamed to
74 Names before typechecking, because there should be no scope errors etc.
76 -- For (b) consider: f = $(...h....)
77 -- where h is imported, and calls f via an hi-boot file.
78 -- This is bad! But it is not seen as a staging error, because h
79 -- is indeed imported. We don't want the type-checker to black-hole
80 -- when simplifying and compiling the splice!
82 -- Simple solution: discard any unfolding that mentions a variable
83 -- bound in this module (and hence not yet processed).
84 -- The discarding happens when forkM finds a type error.
86 %************************************************************************
88 %* tcImportDecl is the key function for "faulting in" *
91 %************************************************************************
93 The main idea is this. We are chugging along type-checking source code, and
94 find a reference to GHC.Base.map. We call tcLookupGlobal, which doesn't find
95 it in the EPS type envt. So it
97 2 gets the decl for GHC.Base.map
98 3 typechecks it via tcIfaceDecl
99 4 and adds it to the type env in the EPS
101 Note that DURING STEP 4, we may find that map's type mentions a type
102 constructor that also
104 Notice that for imported things we read the current version from the EPS
105 mutable variable. This is important in situations like
107 where the code that e1 expands to might import some defns that
108 also turn out to be needed by the code that e2 expands to.
111 tcImportDecl :: Name -> TcM TyThing
112 -- Entry point for *source-code* uses of importDecl
114 | Just thing <- wiredInNameTyThing_maybe name
115 = do { initIfaceTcRn (loadWiredInHomeIface name)
118 = do { traceIf (text "tcImportDecl" <+> ppr name)
119 ; mb_thing <- initIfaceTcRn (importDecl name)
121 Succeeded thing -> return thing
122 Failed err -> failWithTc err }
124 checkWiredInTyCon :: TyCon -> TcM ()
125 -- Ensure that the home module of the TyCon (and hence its instances)
126 -- are loaded. It might not be a wired-in tycon (see the calls in TcUnify),
127 -- in which case this is a no-op.
129 | not (isWiredInName tc_name)
132 = do { mod <- getModule
133 ; if nameIsLocalOrFrom mod tc_name then
134 -- Don't look for (non-existent) Float.hi when
135 -- compiling Float.lhs, which mentions Float of course
137 else -- A bit yukky to call initIfaceTcRn here
138 initIfaceTcRn (loadWiredInHomeIface tc_name)
141 tc_name = tyConName tc
143 importDecl :: Name -> IfM lcl (MaybeErr Message TyThing)
144 -- Get the TyThing for this Name from an interface file
145 -- It's not a wired-in thing -- the caller caught that
147 = ASSERT( not (isWiredInName name) )
150 -- Load the interface, which should populate the PTE
151 ; mb_iface <- loadInterface nd_doc (nameModule name) ImportBySystem
153 Failed err_msg -> return (Failed err_msg) ;
154 Succeeded iface -> do
156 -- Now look it up again; this time we should find it
158 ; case lookupTypeEnv (eps_PTE eps) name of
159 Just thing -> return (Succeeded thing)
160 Nothing -> return (Failed not_found_msg)
163 nd_doc = ptext SLIT("Need decl for") <+> ppr name
164 not_found_msg = hang (ptext SLIT("Can't find interface-file declaration for") <+> ppr (nameParent name))
165 2 (vcat [ptext SLIT("Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
166 ptext SLIT("Use -ddump-if-trace to get an idea of which file caused the error")])
169 %************************************************************************
171 Type-checking a complete interface
173 %************************************************************************
175 Suppose we discover we don't need to recompile. Then we must type
176 check the old interface file. This is a bit different to the
177 incremental type checking we do as we suck in interface files. Instead
178 we do things similarly as when we are typechecking source decls: we
179 bring into scope the type envt for the interface all at once, using a
180 knot. Remember, the decls aren't necessarily in dependency order --
181 and even if they were, the type decls might be mutually recursive.
184 typecheckIface :: ModIface -- Get the decls from here
185 -> TcRnIf gbl lcl ModDetails
187 = initIfaceTc iface $ \ tc_env_var -> do
188 -- The tc_env_var is freshly allocated, private to
189 -- type-checking this particular interface
190 { -- Get the right set of decls and rules. If we are compiling without -O
191 -- we discard pragmas before typechecking, so that we don't "see"
192 -- information that we shouldn't. From a versioning point of view
193 -- It's not actually *wrong* to do so, but in fact GHCi is unable
194 -- to handle unboxed tuples, so it must not see unfoldings.
195 ignore_prags <- doptM Opt_IgnoreInterfacePragmas
197 -- Load & typecheck the decls
198 ; decl_things <- loadDecls ignore_prags (mi_decls iface)
200 ; let type_env = mkNameEnv decl_things
201 ; writeMutVar tc_env_var type_env
203 -- Now do those rules and instances
204 ; let { rules | ignore_prags = []
205 | otherwise = mi_rules iface
206 ; dfuns = mi_insts iface
208 ; dfuns <- mapM tcIfaceInst dfuns
209 ; rules <- mapM tcIfaceRule rules
212 ; exports <- ifaceExportNames (mi_exports iface)
215 ; return (ModDetails { md_types = type_env,
218 md_exports = exports })
223 %************************************************************************
225 Type and class declarations
227 %************************************************************************
230 tcHiBootIface :: Module -> TcRn ModDetails
231 -- Load the hi-boot iface for the module being compiled,
232 -- if it indeed exists in the transitive closure of imports
233 -- Return the ModDetails, empty if no hi-boot iface
235 = do { traceIf (text "loadHiBootInterface" <+> ppr mod)
238 ; if not (isOneShot mode)
239 -- In --make and interactive mode, if this module has an hs-boot file
240 -- we'll have compiled it already, and it'll be in the HPT
242 -- We check wheher the interface is a *boot* interface.
243 -- It can happen (when using GHC from Visual Studio) that we
244 -- compile a module in TypecheckOnly mode, with a stable,
245 -- fully-populated HPT. In that case the boot interface isn't there
246 -- (it's been replaced by the mother module) so we can't check it.
247 -- And that's fine, because if M's ModInfo is in the HPT, then
248 -- it's been compiled once, and we don't need to check the boot iface
249 then do { hpt <- getHpt
250 ; case lookupUFM hpt (moduleName mod) of
251 Just info | mi_boot (hm_iface info)
252 -> return (hm_details info)
253 other -> return emptyModDetails }
256 -- OK, so we're in one-shot mode.
257 -- In that case, we're read all the direct imports by now,
258 -- so eps_is_boot will record if any of our imports mention us by
259 -- way of hi-boot file
261 ; case lookupUFM (eps_is_boot eps) (moduleName mod) of {
262 Nothing -> return emptyModDetails ; -- The typical case
264 Just (_, False) -> failWithTc moduleLoop ;
265 -- Someone below us imported us!
266 -- This is a loop with no hi-boot in the way
268 Just (_mod, True) -> -- There's a hi-boot interface below us
270 do { read_result <- findAndReadIface
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 -- ToDo: in hs-boot files we should really treat abstract classes specially,
380 -- as we do abstract tycons
381 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
382 { cls_name <- lookupIfaceTop occ_name
383 ; ctxt <- tcIfaceCtxt rdr_ctxt
384 ; sigs <- mappM tc_sig rdr_sigs
385 ; fds <- mappM tc_fd rdr_fds
386 ; cls <- buildClass cls_name tyvars ctxt fds sigs tc_isrec tc_vrcs
387 ; return (AClass cls) }
389 tc_sig (IfaceClassOp occ dm rdr_ty)
390 = do { op_name <- lookupIfaceTop occ
391 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
392 -- Must be done lazily for just the same reason as the
393 -- context of a data decl: the type sig might mention the
394 -- class being defined
395 ; return (op_name, dm, op_ty) }
397 mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
399 tc_fd (tvs1, tvs2) = do { tvs1' <- mappM tcIfaceTyVar tvs1
400 ; tvs2' <- mappM tcIfaceTyVar tvs2
401 ; return (tvs1', tvs2') }
403 tcIfaceDecl (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
404 = do { name <- lookupIfaceTop rdr_name
405 ; return (ATyCon (mkForeignTyCon name ext_name
406 liftedTypeKind 0 [])) }
408 tcIfaceDataCons tycon tc_tyvars if_cons
410 IfAbstractTyCon -> return mkAbstractTyConRhs
411 IfDataTyCon cons -> do { data_cons <- mappM tc_con_decl cons
412 ; return (mkDataTyConRhs data_cons) }
413 IfNewTyCon con -> do { data_con <- tc_con_decl con
414 ; return (mkNewTyConRhs tycon data_con) }
416 tc_con_decl (IfVanillaCon { ifConOcc = occ, ifConInfix = is_infix, ifConArgTys = args,
417 ifConStricts = stricts, ifConFields = field_lbls})
418 = do { name <- lookupIfaceTop occ
419 -- Read the argument types, but lazily to avoid faulting in
420 -- the component types unless they are really needed
421 ; arg_tys <- forkM (mk_doc name) (mappM tcIfaceType args)
422 ; lbl_names <- mappM lookupIfaceTop field_lbls
423 ; buildDataCon name is_infix True {- Vanilla -}
425 tc_tyvars [] arg_tys tycon
426 (mkTyVarTys tc_tyvars) -- Vanilla => we know result tys
429 tc_con_decl (IfGadtCon { ifConTyVars = con_tvs,
430 ifConOcc = occ, ifConCtxt = ctxt,
431 ifConArgTys = args, ifConResTys = ress,
432 ifConStricts = stricts})
433 = bindIfaceTyVars con_tvs $ \ con_tyvars -> do
434 { name <- lookupIfaceTop occ
435 ; theta <- tcIfaceCtxt ctxt -- Laziness seems not worth the bother here
436 -- At one stage I thought that this context checking *had*
437 -- to be lazy, because of possible mutual recursion between the
438 -- type and the classe:
440 -- class Real a where { toRat :: a -> Ratio Integer }
441 -- data (Real a) => Ratio a = ...
442 -- But now I think that the laziness in checking class ops breaks
443 -- the loop, so no laziness needed
445 -- Read the argument types, but lazily to avoid faulting in
446 -- the component types unless they are really needed
447 ; arg_tys <- forkM (mk_doc name) (mappM tcIfaceType args)
448 ; res_tys <- forkM (mk_doc name) (mappM tcIfaceType ress)
450 ; buildDataCon name False {- Not infix -} False {- Not vanilla -}
451 stricts [{- No fields -}]
453 arg_tys tycon res_tys
455 mk_doc con_name = ptext SLIT("Constructor") <+> ppr con_name
459 %************************************************************************
463 %************************************************************************
466 tcIfaceInst :: IfaceInst -> IfL Instance
467 tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
468 ifInstCls = cls, ifInstTys = mb_tcs,
470 = do { dfun <- forkM (ptext SLIT("Dict fun") <+> ppr dfun_occ) $
471 tcIfaceExtId (LocalTop dfun_occ)
472 ; cls' <- lookupIfaceExt cls
473 ; mb_tcs' <- mapM do_tc mb_tcs
474 ; return (mkImportedInstance cls' mb_tcs' orph dfun oflag) }
476 do_tc Nothing = return Nothing
477 do_tc (Just tc) = do { tc' <- lookupIfaceTc tc; return (Just tc') }
481 %************************************************************************
485 %************************************************************************
487 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
488 are in the type environment. However, remember that typechecking a Rule may
489 (as a side effect) augment the type envt, and so we may need to iterate the process.
492 tcIfaceRule :: IfaceRule -> IfL CoreRule
493 tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,
494 ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs,
496 = do { fn' <- lookupIfaceExt fn
497 ; ~(bndrs', args', rhs') <-
498 -- Typecheck the payload lazily, in the hope it'll never be looked at
499 forkM (ptext SLIT("Rule") <+> ftext name) $
500 bindIfaceBndrs bndrs $ \ bndrs' ->
501 do { args' <- mappM tcIfaceExpr args
502 ; rhs' <- tcIfaceExpr rhs
503 ; return (bndrs', args', rhs') }
504 ; mb_tcs <- mapM ifTopFreeName args
505 ; returnM (Rule { ru_name = name, ru_fn = fn', ru_act = act,
506 ru_bndrs = bndrs', ru_args = args',
507 ru_rhs = rhs', ru_orph = orph,
509 ru_local = isLocalIfaceExtName fn }) }
511 -- This function *must* mirror exactly what Rules.topFreeName does
512 -- We could have stored the ru_rough field in the iface file
513 -- but that would be redundant, I think.
514 -- The only wrinkle is that we must not be deceived by
515 -- type syononyms at the top of a type arg. Since
516 -- we can't tell at this point, we are careful not
517 -- to write them out in coreRuleToIfaceRule
518 ifTopFreeName :: IfaceExpr -> IfL (Maybe Name)
519 ifTopFreeName (IfaceType (IfaceTyConApp tc _ ))
520 = do { n <- lookupIfaceTc tc
522 ifTopFreeName (IfaceApp f a) = ifTopFreeName f
523 ifTopFreeName (IfaceExt ext) = do { n <- lookupIfaceExt ext
525 ifTopFreeName other = return Nothing
529 %************************************************************************
533 %************************************************************************
536 tcIfaceType :: IfaceType -> IfL Type
537 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
538 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
539 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
540 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkTyConApp tc' ts') }
541 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
542 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
544 tcIfaceTypes tys = mapM tcIfaceType tys
546 -----------------------------------------
547 tcIfacePredType :: IfacePredType -> IfL PredType
548 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
549 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
551 -----------------------------------------
552 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
553 tcIfaceCtxt sts = mappM tcIfacePredType sts
557 %************************************************************************
561 %************************************************************************
564 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
565 tcIfaceExpr (IfaceType ty)
566 = tcIfaceType ty `thenM` \ ty' ->
569 tcIfaceExpr (IfaceLcl name)
570 = tcIfaceLclId name `thenM` \ id ->
573 tcIfaceExpr (IfaceExt gbl)
574 = tcIfaceExtId gbl `thenM` \ id ->
577 tcIfaceExpr (IfaceLit lit)
580 tcIfaceExpr (IfaceFCall cc ty)
581 = tcIfaceType ty `thenM` \ ty' ->
582 newUnique `thenM` \ u ->
583 returnM (Var (mkFCallId u cc ty'))
585 tcIfaceExpr (IfaceTuple boxity args)
586 = mappM tcIfaceExpr args `thenM` \ args' ->
588 -- Put the missing type arguments back in
589 con_args = map (Type . exprType) args' ++ args'
591 returnM (mkApps (Var con_id) con_args)
594 con_id = dataConWorkId (tupleCon boxity arity)
597 tcIfaceExpr (IfaceLam bndr body)
598 = bindIfaceBndr bndr $ \ bndr' ->
599 tcIfaceExpr body `thenM` \ body' ->
600 returnM (Lam bndr' body')
602 tcIfaceExpr (IfaceApp fun arg)
603 = tcIfaceExpr fun `thenM` \ fun' ->
604 tcIfaceExpr arg `thenM` \ arg' ->
605 returnM (App fun' arg')
607 tcIfaceExpr (IfaceCase scrut case_bndr ty alts)
608 = tcIfaceExpr scrut `thenM` \ scrut' ->
609 newIfaceName (mkVarOccFS case_bndr) `thenM` \ case_bndr_name ->
611 scrut_ty = exprType scrut'
612 case_bndr' = mkLocalId case_bndr_name scrut_ty
613 tc_app = splitTyConApp scrut_ty
614 -- NB: Won't always succeed (polymoprhic case)
615 -- but won't be demanded in those cases
616 -- NB: not tcSplitTyConApp; we are looking at Core here
617 -- look through non-rec newtypes to find the tycon that
618 -- corresponds to the datacon in this case alternative
620 extendIfaceIdEnv [case_bndr'] $
621 mappM (tcIfaceAlt tc_app) alts `thenM` \ alts' ->
622 tcIfaceType ty `thenM` \ ty' ->
623 returnM (Case scrut' case_bndr' ty' alts')
625 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body)
626 = tcIfaceExpr rhs `thenM` \ rhs' ->
627 bindIfaceId bndr $ \ bndr' ->
628 tcIfaceExpr body `thenM` \ body' ->
629 returnM (Let (NonRec bndr' rhs') body')
631 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
632 = bindIfaceIds bndrs $ \ bndrs' ->
633 mappM tcIfaceExpr rhss `thenM` \ rhss' ->
634 tcIfaceExpr body `thenM` \ body' ->
635 returnM (Let (Rec (bndrs' `zip` rhss')) body')
637 (bndrs, rhss) = unzip pairs
639 tcIfaceExpr (IfaceNote note expr)
640 = tcIfaceExpr expr `thenM` \ expr' ->
642 IfaceCoerce to_ty -> tcIfaceType to_ty `thenM` \ to_ty' ->
643 returnM (Note (Coerce to_ty'
644 (exprType expr')) expr')
645 IfaceInlineMe -> returnM (Note InlineMe expr')
646 IfaceSCC cc -> returnM (Note (SCC cc) expr')
647 IfaceCoreNote n -> returnM (Note (CoreNote n) expr')
649 -------------------------
650 tcIfaceAlt _ (IfaceDefault, names, rhs)
651 = ASSERT( null names )
652 tcIfaceExpr rhs `thenM` \ rhs' ->
653 returnM (DEFAULT, [], rhs')
655 tcIfaceAlt _ (IfaceLitAlt lit, names, rhs)
656 = ASSERT( null names )
657 tcIfaceExpr rhs `thenM` \ rhs' ->
658 returnM (LitAlt lit, [], rhs')
660 -- A case alternative is made quite a bit more complicated
661 -- by the fact that we omit type annotations because we can
662 -- work them out. True enough, but its not that easy!
663 tcIfaceAlt (tycon, inst_tys) (IfaceDataAlt data_occ, arg_strs, rhs)
664 = do { let tycon_mod = nameModule (tyConName tycon)
665 ; con <- tcIfaceDataCon (ExtPkg tycon_mod data_occ)
666 ; ASSERT2( con `elem` tyConDataCons tycon,
667 ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon) )
669 if isVanillaDataCon con then
670 tcVanillaAlt con inst_tys arg_strs rhs
673 let (tyvar_strs, id_strs) = splitAtList (dataConTyVars con) arg_strs
674 ; tyvar_names <- mapM (newIfaceName . mkTyVarOcc) tyvar_strs
675 ; id_names <- mapM (newIfaceName . mkVarOccFS) id_strs
676 ; let tyvars = [ mkTyVar name (tyVarKind tv)
677 | (name,tv) <- tyvar_names `zip` dataConTyVars con ]
678 arg_tys = dataConInstArgTys con (mkTyVarTys tyvars)
679 arg_ids = ASSERT2( equalLength id_names arg_tys,
680 ppr (con, tyvar_names++id_names, rhs) $$ ppr tyvars $$ ppr arg_tys )
681 zipWith mkLocalId id_names arg_tys
683 Just refine = coreRefineTys con tyvars (mkTyConApp tycon inst_tys)
685 ; rhs' <- extendIfaceTyVarEnv tyvars $
686 extendIfaceIdEnv arg_ids $
687 refineIfaceIdEnv refine $
688 -- You might think that we don't need to refine the envt here,
689 -- but we do: \(x::a) -> case y of
690 -- MkT -> case x of { True -> ... }
691 -- In the "case x" we need to know x's type, because we use that
692 -- to find which module to look for "True" in. Sigh.
694 ; return (DataAlt con, tyvars ++ arg_ids, rhs') }}
696 tcIfaceAlt (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
697 = ASSERT( isTupleTyCon tycon )
698 do { let [data_con] = tyConDataCons tycon
699 ; tcVanillaAlt data_con inst_tys arg_occs rhs }
701 tcVanillaAlt data_con inst_tys arg_strs rhs
702 = do { arg_names <- newIfaceNames (map mkVarOccFS arg_strs)
703 ; let arg_tys = dataConInstArgTys data_con inst_tys
704 ; let arg_ids = ASSERT2( equalLength arg_names arg_tys,
705 ppr data_con <+> ppr inst_tys <+> ppr arg_strs $$ ppr rhs )
706 zipWith mkLocalId arg_names arg_tys
707 ; rhs' <- extendIfaceIdEnv arg_ids (tcIfaceExpr rhs)
708 ; returnM (DataAlt data_con, arg_ids, rhs') }
713 tcExtCoreBindings :: [IfaceBinding] -> IfL [CoreBind] -- Used for external core
714 tcExtCoreBindings [] = return []
715 tcExtCoreBindings (b:bs) = do_one b (tcExtCoreBindings bs)
717 do_one :: IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
718 do_one (IfaceNonRec bndr rhs) thing_inside
719 = do { rhs' <- tcIfaceExpr rhs
720 ; bndr' <- newExtCoreBndr bndr
721 ; extendIfaceIdEnv [bndr'] $ do
722 { core_binds <- thing_inside
723 ; return (NonRec bndr' rhs' : core_binds) }}
725 do_one (IfaceRec pairs) thing_inside
726 = do { bndrs' <- mappM newExtCoreBndr bndrs
727 ; extendIfaceIdEnv bndrs' $ do
728 { rhss' <- mappM tcIfaceExpr rhss
729 ; core_binds <- thing_inside
730 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
732 (bndrs,rhss) = unzip pairs
736 %************************************************************************
740 %************************************************************************
743 tcIdInfo :: Name -> Type -> IfaceIdInfo -> IfL IdInfo
744 tcIdInfo name ty NoInfo = return vanillaIdInfo
745 tcIdInfo name ty (HasInfo info) = foldlM tcPrag init_info info
747 -- Set the CgInfo to something sensible but uninformative before
748 -- we start; default assumption is that it has CAFs
749 init_info = vanillaIdInfo
751 tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
752 tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
753 tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
755 -- The next two are lazy, so they don't transitively suck stuff in
756 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
757 tcPrag info (HsInline inline_prag) = returnM (info `setInlinePragInfo` inline_prag)
758 tcPrag info (HsUnfold expr)
759 = tcPragExpr name expr `thenM` \ maybe_expr' ->
761 -- maybe_expr' doesn't get looked at if the unfolding
762 -- is never inspected; so the typecheck doesn't even happen
763 unfold_info = case maybe_expr' of
764 Nothing -> noUnfolding
765 Just expr' -> mkTopUnfolding expr'
767 returnM (info `setUnfoldingInfoLazily` unfold_info)
771 tcWorkerInfo ty info wkr arity
772 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId wkr)
774 -- We return without testing maybe_wkr_id, but as soon as info is
775 -- looked at we will test it. That's ok, because its outside the
776 -- knot; and there seems no big reason to further defer the
777 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
778 -- over the unfolding until it's actually used does seem worth while.)
779 ; us <- newUniqueSupply
781 ; returnM (case mb_wkr_id of
783 Just wkr_id -> add_wkr_info us wkr_id info) }
785 doc = text "Worker for" <+> ppr wkr
786 add_wkr_info us wkr_id info
787 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
788 `setWorkerInfo` HasWorker wkr_id arity
790 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
792 -- We are relying here on strictness info always appearing
793 -- before worker info, fingers crossed ....
794 strict_sig = case newStrictnessInfo info of
796 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr)
799 For unfoldings we try to do the job lazily, so that we never type check
800 an unfolding that isn't going to be looked at.
803 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
806 tcIfaceExpr expr `thenM` \ core_expr' ->
808 -- Check for type consistency in the unfolding
809 ifOptM Opt_DoCoreLinting (
810 get_in_scope_ids `thenM` \ in_scope ->
811 case lintUnfolding noSrcLoc in_scope core_expr' of
812 Nothing -> returnM ()
813 Just fail_msg -> pprPanic "Iface Lint failure" (doc <+> fail_msg)
818 doc = text "Unfolding of" <+> ppr name
819 get_in_scope_ids -- Urgh; but just for linting
821 do { env <- getGblEnv
822 ; case if_rec_types env of {
823 Nothing -> return [] ;
824 Just (_, get_env) -> do
825 { type_env <- get_env
826 ; return (typeEnvIds type_env) }}}
831 %************************************************************************
833 Getting from Names to TyThings
835 %************************************************************************
838 tcIfaceGlobal :: Name -> IfL TyThing
840 | Just thing <- wiredInNameTyThing_maybe name
841 -- Wired-in things include TyCons, DataCons, and Ids
842 = do { loadWiredInHomeIface name; return thing }
843 -- Even though we are in an interface file, we want to make
844 -- sure its instances are loaded (imagine f :: Double -> Double)
845 -- and its RULES are loaded too
847 = do { (eps,hpt) <- getEpsAndHpt
849 ; case lookupType dflags hpt (eps_PTE eps) name of {
850 Just thing -> return thing ;
854 ; case if_rec_types env of {
855 Just (mod, get_type_env)
856 | nameIsLocalOrFrom mod name
857 -> do -- It's defined in the module being compiled
858 { type_env <- setLclEnv () get_type_env -- yuk
859 ; case lookupNameEnv type_env name of
860 Just thing -> return thing
861 Nothing -> pprPanic "tcIfaceGlobal (local): not found:"
862 (ppr name $$ ppr type_env) }
866 { mb_thing <- importDecl name -- It's imported; go get it
868 Failed err -> failIfM err
869 Succeeded thing -> return thing
872 tcIfaceTyCon :: IfaceTyCon -> IfL TyCon
873 tcIfaceTyCon IfaceIntTc = tcWiredInTyCon intTyCon
874 tcIfaceTyCon IfaceBoolTc = tcWiredInTyCon boolTyCon
875 tcIfaceTyCon IfaceCharTc = tcWiredInTyCon charTyCon
876 tcIfaceTyCon IfaceListTc = tcWiredInTyCon listTyCon
877 tcIfaceTyCon IfacePArrTc = tcWiredInTyCon parrTyCon
878 tcIfaceTyCon (IfaceTupTc bx ar) = tcWiredInTyCon (tupleTyCon bx ar)
879 tcIfaceTyCon (IfaceTc ext_nm) = do { name <- lookupIfaceExt ext_nm
880 ; thing <- tcIfaceGlobal name
881 ; return (check_tc (tyThingTyCon thing)) }
884 check_tc tc = case toIfaceTyCon (error "urk") tc of
886 other -> pprTrace "check_tc" (ppr tc) tc
891 -- Even though we are in an interface file, we want to make
892 -- sure the instances and RULES of this tycon are loaded
893 -- Imagine: f :: Double -> Double
894 tcWiredInTyCon :: TyCon -> IfL TyCon
895 tcWiredInTyCon tc = do { loadWiredInHomeIface (tyConName tc)
898 tcIfaceClass :: IfaceExtName -> IfL Class
899 tcIfaceClass rdr_name = do { name <- lookupIfaceExt rdr_name
900 ; thing <- tcIfaceGlobal name
901 ; return (tyThingClass thing) }
903 tcIfaceDataCon :: IfaceExtName -> IfL DataCon
904 tcIfaceDataCon gbl = do { name <- lookupIfaceExt gbl
905 ; thing <- tcIfaceGlobal name
907 ADataCon dc -> return dc
908 other -> pprPanic "tcIfaceExtDC" (ppr gbl $$ ppr name$$ ppr thing) }
910 tcIfaceExtId :: IfaceExtName -> IfL Id
911 tcIfaceExtId gbl = do { name <- lookupIfaceExt gbl
912 ; thing <- tcIfaceGlobal name
915 other -> pprPanic "tcIfaceExtId" (ppr gbl $$ ppr name$$ ppr thing) }
918 %************************************************************************
922 %************************************************************************
925 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
926 bindIfaceBndr (IfaceIdBndr bndr) thing_inside
927 = bindIfaceId bndr thing_inside
928 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
929 = bindIfaceTyVar bndr thing_inside
931 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
932 bindIfaceBndrs [] thing_inside = thing_inside []
933 bindIfaceBndrs (b:bs) thing_inside
934 = bindIfaceBndr b $ \ b' ->
935 bindIfaceBndrs bs $ \ bs' ->
936 thing_inside (b':bs')
938 -----------------------
939 bindIfaceId :: IfaceIdBndr -> (Id -> IfL a) -> IfL a
940 bindIfaceId (occ, ty) thing_inside
941 = do { name <- newIfaceName (mkVarOccFS occ)
942 ; ty' <- tcIfaceType ty
943 ; let { id = mkLocalId name ty' }
944 ; extendIfaceIdEnv [id] (thing_inside id) }
946 bindIfaceIds :: [IfaceIdBndr] -> ([Id] -> IfL a) -> IfL a
947 bindIfaceIds bndrs thing_inside
948 = do { names <- newIfaceNames (map mkVarOccFS occs)
949 ; tys' <- mappM tcIfaceType tys
950 ; let { ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys' }
951 ; extendIfaceIdEnv ids (thing_inside ids) }
953 (occs,tys) = unzip bndrs
956 -----------------------
957 newExtCoreBndr :: IfaceIdBndr -> IfL Id
958 newExtCoreBndr (var, ty)
959 = do { mod <- getIfModule
960 ; name <- newGlobalBinder mod (mkVarOccFS var) Nothing noSrcLoc
961 ; ty' <- tcIfaceType ty
962 ; return (mkLocalId name ty') }
964 -----------------------
965 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
966 bindIfaceTyVar (occ,kind) thing_inside
967 = do { name <- newIfaceName (mkTyVarOcc occ)
968 ; let tyvar = mk_iface_tyvar name kind
969 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
971 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
972 bindIfaceTyVars bndrs thing_inside
973 = do { names <- newIfaceNames (map mkTyVarOcc occs)
974 ; let tyvars = zipWith mk_iface_tyvar names kinds
975 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
977 (occs,kinds) = unzip bndrs
979 mk_iface_tyvar name kind = mkTyVar name kind