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 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 )
35 import CoreUtils ( exprType )
37 import CoreLint ( lintUnfolding )
38 import WorkWrap ( mkWrapper )
39 import Id ( Id, mkVanillaGlobal, mkLocalId )
40 import MkId ( mkFCallId )
41 import IdInfo ( IdInfo, CafInfo(..), WorkerInfo(..),
42 setUnfoldingInfoLazily, setAllStrictnessInfo, setWorkerInfo,
43 setArityInfo, setInlinePragInfo, setCafInfo,
44 vanillaIdInfo, newStrictnessInfo )
45 import Class ( Class )
46 import TyCon ( tyConDataCons, isTupleTyCon, mkForeignTyCon )
47 import DataCon ( DataCon, dataConWorkId, dataConTyVars, dataConInstArgTys, isVanillaDataCon )
48 import TysWiredIn ( tupleCon, tupleTyCon, listTyCon, intTyCon, boolTyCon, charTyCon, parrTyCon )
49 import Var ( TyVar, mkTyVar, tyVarKind )
50 import Name ( Name, nameModule, nameIsLocalOrFrom, isWiredInName,
51 wiredInNameTyThing_maybe, nameParent )
53 import OccName ( OccName )
54 import Module ( Module, lookupModuleEnv )
55 import UniqSupply ( initUs_ )
57 import ErrUtils ( Message )
58 import Maybes ( MaybeErr(..) )
59 import SrcLoc ( noSrcLoc )
60 import Util ( zipWithEqual, dropList, equalLength )
61 import DynFlags ( DynFlag(..), isOneShot )
70 An IfaceDecl is populated with RdrNames, and these are not renamed to
71 Names before typechecking, because there should be no scope errors etc.
73 -- For (b) consider: f = $(...h....)
74 -- where h is imported, and calls f via an hi-boot file.
75 -- This is bad! But it is not seen as a staging error, because h
76 -- is indeed imported. We don't want the type-checker to black-hole
77 -- when simplifying and compiling the splice!
79 -- Simple solution: discard any unfolding that mentions a variable
80 -- bound in this module (and hence not yet processed).
81 -- The discarding happens when forkM finds a type error.
83 %************************************************************************
85 %* tcImportDecl is the key function for "faulting in" *
88 %************************************************************************
90 The main idea is this. We are chugging along type-checking source code, and
91 find a reference to GHC.Base.map. We call tcLookupGlobal, which doesn't find
92 it in the EPS type envt. So it
94 2 gets the decl for GHC.Base.map
95 3 typechecks it via tcIfaceDecl
96 4 and adds it to the type env in the EPS
98 Note that DURING STEP 4, we may find that map's type mentions a type
101 Notice that for imported things we read the current version from the EPS
102 mutable variable. This is important in situations like
104 where the code that e1 expands to might import some defns that
105 also turn out to be needed by the code that e2 expands to.
108 tcImportDecl :: Name -> TcM TyThing
109 -- Entry point for *source-code* uses of importDecl
111 | Just thing <- wiredInNameTyThing_maybe name
112 = do { initIfaceTcRn (loadWiredInHomeIface name)
115 = do { traceIf (text "tcImportDecl" <+> ppr name)
116 ; mb_thing <- initIfaceTcRn (importDecl name)
118 Succeeded thing -> return thing
119 Failed err -> failWithTc err }
121 checkWiredInTyCon :: TyCon -> TcM ()
122 -- Ensure that the home module of the TyCon (and hence its instances)
123 -- are loaded. It might not be a wired-in tycon (see the calls in TcUnify),
124 -- in which case this is a no-op.
126 | not (isWiredInName tc_name)
129 = do { mod <- getModule
130 ; if nameIsLocalOrFrom mod tc_name then
131 -- Don't look for (non-existent) Float.hi when
132 -- compiling Float.lhs, which mentions Float of course
134 else -- A bit yukky to call initIfaceTcRn here
135 initIfaceTcRn (loadWiredInHomeIface tc_name)
138 tc_name = tyConName tc
140 importDecl :: Name -> IfM lcl (MaybeErr Message TyThing)
141 -- Get the TyThing for this Name from an interface file
142 -- It's not a wired-in thing -- the caller caught that
144 = ASSERT( not (isWiredInName name) )
147 -- Load the interface, which should populate the PTE
148 ; mb_iface <- loadInterface nd_doc (nameModule name) ImportBySystem
150 Failed err_msg -> return (Failed err_msg) ;
151 Succeeded iface -> do
153 -- Now look it up again; this time we should find it
155 ; case lookupTypeEnv (eps_PTE eps) name of
156 Just thing -> return (Succeeded thing)
157 Nothing -> return (Failed not_found_msg)
160 nd_doc = ptext SLIT("Need decl for") <+> ppr name
161 not_found_msg = hang (ptext SLIT("Can't find interface-file declaration for") <+> ppr (nameParent name))
162 2 (vcat [ptext SLIT("Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
163 ptext SLIT("Use -ddump-if-trace to get an idea of which file caused the error")])
166 %************************************************************************
168 Type-checking a complete interface
170 %************************************************************************
172 Suppose we discover we don't need to recompile. Then we must type
173 check the old interface file. This is a bit different to the
174 incremental type checking we do as we suck in interface files. Instead
175 we do things similarly as when we are typechecking source decls: we
176 bring into scope the type envt for the interface all at once, using a
177 knot. Remember, the decls aren't necessarily in dependency order --
178 and even if they were, the type decls might be mutually recursive.
181 typecheckIface :: ModIface -- Get the decls from here
182 -> TcRnIf gbl lcl ModDetails
184 = initIfaceTc iface $ \ tc_env_var -> do
185 -- The tc_env_var is freshly allocated, private to
186 -- type-checking this particular interface
187 { -- Get the right set of decls and rules. If we are compiling without -O
188 -- we discard pragmas before typechecking, so that we don't "see"
189 -- information that we shouldn't. From a versioning point of view
190 -- It's not actually *wrong* to do so, but in fact GHCi is unable
191 -- to handle unboxed tuples, so it must not see unfoldings.
192 ignore_prags <- doptM Opt_IgnoreInterfacePragmas
194 -- Load & typecheck the decls
195 ; decl_things <- loadDecls ignore_prags (mi_decls iface)
197 ; let type_env = mkNameEnv decl_things
198 ; writeMutVar tc_env_var type_env
200 -- Now do those rules and instances
201 ; let { rules | ignore_prags = []
202 | otherwise = mi_rules iface
203 ; dfuns = mi_insts iface
205 ; dfuns <- mapM tcIfaceInst dfuns
206 ; rules <- mapM tcIfaceRule rules
209 ; exports <- ifaceExportNames (mi_exports iface)
212 ; return (ModDetails { md_types = type_env,
215 md_exports = exports })
220 %************************************************************************
222 Type and class declarations
224 %************************************************************************
227 tcHiBootIface :: Module -> TcRn ModDetails
228 -- Load the hi-boot iface for the module being compiled,
229 -- if it indeed exists in the transitive closure of imports
230 -- Return the ModDetails, empty if no hi-boot iface
232 = do { traceIf (text "loadHiBootInterface" <+> ppr mod)
234 ; mode <- getGhciMode
235 ; if not (isOneShot mode)
236 -- In --make and interactive mode, if this module has an hs-boot file
237 -- we'll have compiled it already, and it'll be in the HPT
239 -- We check wheher the interface is a *boot* interface.
240 -- It can happen (when using GHC from Visual Studio) that we
241 -- compile a module in TypecheckOnly mode, with a stable,
242 -- fully-populated HPT. In that case the boot interface isn't there
243 -- (it's been replaced by the mother module) so we can't check it.
244 -- And that's fine, because if M's ModInfo is in the HPT, then
245 -- it's been compiled once, and we don't need to check the boot iface
246 then do { hpt <- getHpt
247 ; case lookupModuleEnv hpt mod of
248 Just info | mi_boot (hm_iface info)
249 -> return (hm_details info)
250 other -> return emptyModDetails }
253 -- OK, so we're in one-shot mode.
254 -- In that case, we're read all the direct imports by now,
255 -- so eps_is_boot will record if any of our imports mention us by
256 -- way of hi-boot file
258 ; case lookupModuleEnv (eps_is_boot eps) mod of {
259 Nothing -> return emptyModDetails ; -- The typical case
261 Just (_, False) -> failWithTc moduleLoop ;
262 -- Someone below us imported us!
263 -- This is a loop with no hi-boot in the way
265 Just (mod, True) -> -- There's a hi-boot interface below us
267 do { read_result <- findAndReadIface
268 True -- Explicit import?
272 ; case read_result of
273 Failed err -> failWithTc (elaborate err)
274 Succeeded (iface, _path) -> typecheckIface iface
277 need = ptext SLIT("Need the hi-boot interface for") <+> ppr mod
278 <+> ptext SLIT("to compare against the Real Thing")
280 moduleLoop = ptext SLIT("Circular imports: module") <+> quotes (ppr mod)
281 <+> ptext SLIT("depends on itself")
283 elaborate err = hang (ptext SLIT("Could not find hi-boot interface for") <+>
284 quotes (ppr mod) <> colon) 4 err
288 %************************************************************************
290 Type and class declarations
292 %************************************************************************
294 When typechecking a data type decl, we *lazily* (via forkM) typecheck
295 the constructor argument types. This is in the hope that we may never
296 poke on those argument types, and hence may never need to load the
297 interface files for types mentioned in the arg types.
300 data Foo.S = MkS Baz.T
301 Mabye we can get away without even loading the interface for Baz!
303 This is not just a performance thing. Suppose we have
304 data Foo.S = MkS Baz.T
305 data Baz.T = MkT Foo.S
306 (in different interface files, of course).
307 Now, first we load and typecheck Foo.S, and add it to the type envt.
308 If we do explore MkS's argument, we'll load and typecheck Baz.T.
309 If we explore MkT's argument we'll find Foo.S already in the envt.
311 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
312 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
313 which isn't done yet.
315 All very cunning. However, there is a rather subtle gotcha which bit
316 me when developing this stuff. When we typecheck the decl for S, we
317 extend the type envt with S, MkS, and all its implicit Ids. Suppose
318 (a bug, but it happened) that the list of implicit Ids depended in
319 turn on the constructor arg types. Then the following sequence of
321 * we build a thunk <t> for the constructor arg tys
322 * we build a thunk for the extended type environment (depends on <t>)
323 * we write the extended type envt into the global EPS mutvar
325 Now we look something up in the type envt
327 * which reads the global type envt out of the global EPS mutvar
328 * but that depends in turn on <t>
330 It's subtle, because, it'd work fine if we typechecked the constructor args
331 eagerly -- they don't need the extended type envt. They just get the extended
332 type envt by accident, because they look at it later.
334 What this means is that the implicitTyThings MUST NOT DEPEND on any of
339 tcIfaceDecl :: IfaceDecl -> IfL TyThing
341 tcIfaceDecl (IfaceId {ifName = occ_name, ifType = iface_type, ifIdInfo = info})
342 = do { name <- lookupIfaceTop occ_name
343 ; ty <- tcIfaceType iface_type
344 ; info <- tcIdInfo name ty info
345 ; return (AnId (mkVanillaGlobal name ty info)) }
347 tcIfaceDecl (IfaceData {ifName = occ_name,
351 ifVrcs = arg_vrcs, ifRec = is_rec,
352 ifGeneric = want_generic })
353 = do { tc_name <- lookupIfaceTop occ_name
354 ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
356 { tycon <- fixM ( \ tycon -> do
357 { stupid_theta <- tcIfaceCtxt ctxt
358 ; cons <- tcIfaceDataCons tycon tyvars rdr_cons
359 ; buildAlgTyCon tc_name tyvars stupid_theta
360 cons arg_vrcs is_rec want_generic
362 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
363 ; return (ATyCon tycon)
366 tcIfaceDecl (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
367 ifSynRhs = rdr_rhs_ty, ifVrcs = arg_vrcs})
368 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
369 { tc_name <- lookupIfaceTop occ_name
370 ; rhs_ty <- tcIfaceType rdr_rhs_ty
371 ; return (ATyCon (buildSynTyCon tc_name tyvars rhs_ty arg_vrcs))
374 tcIfaceDecl (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name, ifTyVars = tv_bndrs,
375 ifFDs = rdr_fds, ifSigs = rdr_sigs,
376 ifVrcs = tc_vrcs, ifRec = tc_isrec })
377 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
378 { cls_name <- lookupIfaceTop occ_name
379 ; ctxt <- tcIfaceCtxt rdr_ctxt
380 ; sigs <- mappM tc_sig rdr_sigs
381 ; fds <- mappM tc_fd rdr_fds
382 ; cls <- buildClass cls_name tyvars ctxt fds sigs tc_isrec tc_vrcs
383 ; return (AClass cls) }
385 tc_sig (IfaceClassOp occ dm rdr_ty)
386 = do { op_name <- lookupIfaceTop occ
387 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
388 -- Must be done lazily for just the same reason as the
389 -- context of a data decl: the type sig might mention the
390 -- class being defined
391 ; return (op_name, dm, op_ty) }
393 mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
395 tc_fd (tvs1, tvs2) = do { tvs1' <- mappM tcIfaceTyVar tvs1
396 ; tvs2' <- mappM tcIfaceTyVar tvs2
397 ; return (tvs1', tvs2') }
399 tcIfaceDecl (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
400 = do { name <- lookupIfaceTop rdr_name
401 ; return (ATyCon (mkForeignTyCon name ext_name
402 liftedTypeKind 0 [])) }
404 tcIfaceDataCons tycon tc_tyvars if_cons
406 IfAbstractTyCon -> return mkAbstractTyConRhs
407 IfDataTyCon cons -> do { data_cons <- mappM tc_con_decl cons
408 ; return (mkDataTyConRhs data_cons) }
409 IfNewTyCon con -> do { data_con <- tc_con_decl con
410 ; return (mkNewTyConRhs tycon data_con) }
412 tc_con_decl (IfVanillaCon { ifConOcc = occ, ifConInfix = is_infix, ifConArgTys = args,
413 ifConStricts = stricts, ifConFields = field_lbls})
414 = do { name <- lookupIfaceTop occ
415 -- Read the argument types, but lazily to avoid faulting in
416 -- the component types unless they are really needed
417 ; arg_tys <- forkM (mk_doc name) (mappM tcIfaceType args)
418 ; lbl_names <- mappM lookupIfaceTop field_lbls
419 ; buildDataCon name is_infix True {- Vanilla -}
421 tc_tyvars [] arg_tys tycon
422 (mkTyVarTys tc_tyvars) -- Vanilla => we know result tys
425 tc_con_decl (IfGadtCon { ifConTyVars = con_tvs,
426 ifConOcc = occ, ifConCtxt = ctxt,
427 ifConArgTys = args, ifConResTys = ress,
428 ifConStricts = stricts})
429 = bindIfaceTyVars con_tvs $ \ con_tyvars -> do
430 { name <- lookupIfaceTop occ
431 ; theta <- tcIfaceCtxt ctxt -- Laziness seems not worth the bother here
432 -- At one stage I thought that this context checking *had*
433 -- to be lazy, because of possible mutual recursion between the
434 -- type and the classe:
436 -- class Real a where { toRat :: a -> Ratio Integer }
437 -- data (Real a) => Ratio a = ...
438 -- But now I think that the laziness in checking class ops breaks
439 -- the loop, so no laziness needed
441 -- Read the argument types, but lazily to avoid faulting in
442 -- the component types unless they are really needed
443 ; arg_tys <- forkM (mk_doc name) (mappM tcIfaceType args)
444 ; res_tys <- forkM (mk_doc name) (mappM tcIfaceType ress)
446 ; buildDataCon name False {- Not infix -} False {- Not vanilla -}
447 stricts [{- No fields -}]
449 arg_tys tycon res_tys
451 mk_doc con_name = ptext SLIT("Constructor") <+> ppr con_name
455 %************************************************************************
459 %************************************************************************
462 tcIfaceInst :: IfaceInst -> IfL Instance
463 tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
464 ifInstCls = cls, ifInstTys = mb_tcs,
466 = do { dfun <- forkM (ptext SLIT("Dict fun") <+> ppr dfun_occ) $
467 tcIfaceExtId (LocalTop dfun_occ)
468 ; cls' <- lookupIfaceExt cls
469 ; mb_tcs' <- mapM do_tc mb_tcs
470 ; return (mkImportedInstance cls' mb_tcs' orph dfun oflag) }
472 do_tc Nothing = return Nothing
473 do_tc (Just tc) = do { tc' <- lookupIfaceTc tc; return (Just tc') }
477 %************************************************************************
481 %************************************************************************
483 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
484 are in the type environment. However, remember that typechecking a Rule may
485 (as a side effect) augment the type envt, and so we may need to iterate the process.
488 tcIfaceRule :: IfaceRule -> IfL CoreRule
489 tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,
490 ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs,
492 = do { fn' <- lookupIfaceExt fn
493 ; ~(bndrs', args', rhs') <-
494 -- Typecheck the payload lazily, in the hope it'll never be looked at
495 forkM (ptext SLIT("Rule") <+> ftext name) $
496 bindIfaceBndrs bndrs $ \ bndrs' ->
497 do { args' <- mappM tcIfaceExpr args
498 ; rhs' <- tcIfaceExpr rhs
499 ; return (bndrs', args', rhs') }
500 ; mb_tcs <- mapM ifTopFreeName args
501 ; returnM (Rule { ru_name = name, ru_fn = fn', ru_act = act,
502 ru_bndrs = bndrs', ru_args = args',
503 ru_rhs = rhs', ru_orph = orph,
505 ru_local = isLocalIfaceExtName fn }) }
507 -- This function *must* mirror exactly what Rules.topFreeName does
508 -- We could have stored the ru_rough field in the iface file
509 -- but that would be redundant, I think.
510 -- The only wrinkle is that we must not be deceived by
511 -- type syononyms at the top of a type arg. Since
512 -- we can't tell at this point, we are careful not
513 -- to write them out in coreRuleToIfaceRule
514 ifTopFreeName :: IfaceExpr -> IfL (Maybe Name)
515 ifTopFreeName (IfaceType (IfaceTyConApp tc _ ))
516 = do { n <- lookupIfaceTc tc
518 ifTopFreeName (IfaceApp f a) = ifTopFreeName f
519 ifTopFreeName (IfaceExt ext) = do { n <- lookupIfaceExt ext
521 ifTopFreeName other = return Nothing
525 %************************************************************************
529 %************************************************************************
532 tcIfaceType :: IfaceType -> IfL Type
533 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
534 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
535 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
536 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkTyConApp tc' ts') }
537 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
538 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
540 tcIfaceTypes tys = mapM tcIfaceType tys
542 -----------------------------------------
543 tcIfacePredType :: IfacePredType -> IfL PredType
544 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
545 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
547 -----------------------------------------
548 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
549 tcIfaceCtxt sts = mappM tcIfacePredType sts
553 %************************************************************************
557 %************************************************************************
560 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
561 tcIfaceExpr (IfaceType ty)
562 = tcIfaceType ty `thenM` \ ty' ->
565 tcIfaceExpr (IfaceLcl name)
566 = tcIfaceLclId name `thenM` \ id ->
569 tcIfaceExpr (IfaceExt gbl)
570 = tcIfaceExtId gbl `thenM` \ id ->
573 tcIfaceExpr (IfaceLit lit)
576 tcIfaceExpr (IfaceFCall cc ty)
577 = tcIfaceType ty `thenM` \ ty' ->
578 newUnique `thenM` \ u ->
579 returnM (Var (mkFCallId u cc ty'))
581 tcIfaceExpr (IfaceTuple boxity args)
582 = mappM tcIfaceExpr args `thenM` \ args' ->
584 -- Put the missing type arguments back in
585 con_args = map (Type . exprType) args' ++ args'
587 returnM (mkApps (Var con_id) con_args)
590 con_id = dataConWorkId (tupleCon boxity arity)
593 tcIfaceExpr (IfaceLam bndr body)
594 = bindIfaceBndr bndr $ \ bndr' ->
595 tcIfaceExpr body `thenM` \ body' ->
596 returnM (Lam bndr' body')
598 tcIfaceExpr (IfaceApp fun arg)
599 = tcIfaceExpr fun `thenM` \ fun' ->
600 tcIfaceExpr arg `thenM` \ arg' ->
601 returnM (App fun' arg')
603 tcIfaceExpr (IfaceCase scrut case_bndr ty alts)
604 = tcIfaceExpr scrut `thenM` \ scrut' ->
605 newIfaceName case_bndr `thenM` \ case_bndr_name ->
607 scrut_ty = exprType scrut'
608 case_bndr' = mkLocalId case_bndr_name scrut_ty
609 tc_app = splitTyConApp scrut_ty
610 -- NB: Won't always succeed (polymoprhic case)
611 -- but won't be demanded in those cases
612 -- NB: not tcSplitTyConApp; we are looking at Core here
613 -- look through non-rec newtypes to find the tycon that
614 -- corresponds to the datacon in this case alternative
616 extendIfaceIdEnv [case_bndr'] $
617 mappM (tcIfaceAlt tc_app) alts `thenM` \ alts' ->
618 tcIfaceType ty `thenM` \ ty' ->
619 returnM (Case scrut' case_bndr' ty' alts')
621 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body)
622 = tcIfaceExpr rhs `thenM` \ rhs' ->
623 bindIfaceId bndr $ \ bndr' ->
624 tcIfaceExpr body `thenM` \ body' ->
625 returnM (Let (NonRec bndr' rhs') body')
627 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
628 = bindIfaceIds bndrs $ \ bndrs' ->
629 mappM tcIfaceExpr rhss `thenM` \ rhss' ->
630 tcIfaceExpr body `thenM` \ body' ->
631 returnM (Let (Rec (bndrs' `zip` rhss')) body')
633 (bndrs, rhss) = unzip pairs
635 tcIfaceExpr (IfaceNote note expr)
636 = tcIfaceExpr expr `thenM` \ expr' ->
638 IfaceCoerce to_ty -> tcIfaceType to_ty `thenM` \ to_ty' ->
639 returnM (Note (Coerce to_ty'
640 (exprType expr')) expr')
641 IfaceInlineCall -> returnM (Note InlineCall expr')
642 IfaceInlineMe -> returnM (Note InlineMe expr')
643 IfaceSCC cc -> returnM (Note (SCC cc) expr')
644 IfaceCoreNote n -> returnM (Note (CoreNote n) expr')
646 -------------------------
647 tcIfaceAlt _ (IfaceDefault, names, rhs)
648 = ASSERT( null names )
649 tcIfaceExpr rhs `thenM` \ rhs' ->
650 returnM (DEFAULT, [], rhs')
652 tcIfaceAlt _ (IfaceLitAlt lit, names, rhs)
653 = ASSERT( null names )
654 tcIfaceExpr rhs `thenM` \ rhs' ->
655 returnM (LitAlt lit, [], rhs')
657 -- A case alternative is made quite a bit more complicated
658 -- by the fact that we omit type annotations because we can
659 -- work them out. True enough, but its not that easy!
660 tcIfaceAlt (tycon, inst_tys) (IfaceDataAlt data_occ, arg_occs, rhs)
661 = do { let tycon_mod = nameModule (tyConName tycon)
662 ; con <- tcIfaceDataCon (ExtPkg tycon_mod data_occ)
663 ; ASSERT2( con `elem` tyConDataCons tycon,
664 ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon) )
666 if isVanillaDataCon con then
667 tcVanillaAlt con inst_tys arg_occs rhs
670 arg_names <- newIfaceNames arg_occs
671 ; let tyvars = [ mkTyVar name (tyVarKind tv)
672 | (name,tv) <- arg_names `zip` dataConTyVars con]
673 arg_tys = dataConInstArgTys con (mkTyVarTys tyvars)
674 id_names = dropList tyvars arg_names
675 arg_ids = ASSERT2( equalLength id_names arg_tys,
676 ppr (con, arg_names, rhs) $$ ppr tyvars $$ ppr arg_tys )
677 zipWith mkLocalId id_names arg_tys
679 ; rhs' <- extendIfaceTyVarEnv tyvars $
680 extendIfaceIdEnv arg_ids $
682 ; return (DataAlt con, tyvars ++ arg_ids, rhs') }}
684 tcIfaceAlt (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
685 = ASSERT( isTupleTyCon tycon )
686 do { let [data_con] = tyConDataCons tycon
687 ; tcVanillaAlt data_con inst_tys arg_occs rhs }
689 tcVanillaAlt data_con inst_tys arg_occs rhs
690 = do { arg_names <- newIfaceNames arg_occs
691 ; let arg_tys = dataConInstArgTys data_con inst_tys
692 ; let arg_ids = ASSERT2( equalLength arg_names arg_tys,
693 ppr data_con <+> ppr inst_tys <+> ppr arg_occs $$ ppr rhs )
694 zipWith mkLocalId arg_names arg_tys
695 ; rhs' <- extendIfaceIdEnv arg_ids (tcIfaceExpr rhs)
696 ; returnM (DataAlt data_con, arg_ids, rhs') }
701 tcExtCoreBindings :: [IfaceBinding] -> IfL [CoreBind] -- Used for external core
702 tcExtCoreBindings [] = return []
703 tcExtCoreBindings (b:bs) = do_one b (tcExtCoreBindings bs)
705 do_one :: IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
706 do_one (IfaceNonRec bndr rhs) thing_inside
707 = do { rhs' <- tcIfaceExpr rhs
708 ; bndr' <- newExtCoreBndr bndr
709 ; extendIfaceIdEnv [bndr'] $ do
710 { core_binds <- thing_inside
711 ; return (NonRec bndr' rhs' : core_binds) }}
713 do_one (IfaceRec pairs) thing_inside
714 = do { bndrs' <- mappM newExtCoreBndr bndrs
715 ; extendIfaceIdEnv bndrs' $ do
716 { rhss' <- mappM tcIfaceExpr rhss
717 ; core_binds <- thing_inside
718 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
720 (bndrs,rhss) = unzip pairs
724 %************************************************************************
728 %************************************************************************
731 tcIdInfo :: Name -> Type -> IfaceIdInfo -> IfL IdInfo
732 tcIdInfo name ty NoInfo = return vanillaIdInfo
733 tcIdInfo name ty (HasInfo info) = foldlM tcPrag init_info info
735 -- Set the CgInfo to something sensible but uninformative before
736 -- we start; default assumption is that it has CAFs
737 init_info = vanillaIdInfo
739 tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
740 tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
741 tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
743 -- The next two are lazy, so they don't transitively suck stuff in
744 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
745 tcPrag info (HsUnfold inline_prag expr)
746 = tcPragExpr name expr `thenM` \ maybe_expr' ->
748 -- maybe_expr' doesn't get looked at if the unfolding
749 -- is never inspected; so the typecheck doesn't even happen
750 unfold_info = case maybe_expr' of
751 Nothing -> noUnfolding
752 Just expr' -> mkTopUnfolding expr'
754 returnM (info `setUnfoldingInfoLazily` unfold_info
755 `setInlinePragInfo` inline_prag)
759 tcWorkerInfo ty info wkr arity
760 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId wkr)
762 -- We return without testing maybe_wkr_id, but as soon as info is
763 -- looked at we will test it. That's ok, because its outside the
764 -- knot; and there seems no big reason to further defer the
765 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
766 -- over the unfolding until it's actually used does seem worth while.)
767 ; us <- newUniqueSupply
769 ; returnM (case mb_wkr_id of
771 Just wkr_id -> add_wkr_info us wkr_id info) }
773 doc = text "Worker for" <+> ppr wkr
774 add_wkr_info us wkr_id info
775 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
776 `setWorkerInfo` HasWorker wkr_id arity
778 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
780 -- We are relying here on strictness info always appearing
781 -- before worker info, fingers crossed ....
782 strict_sig = case newStrictnessInfo info of
784 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr)
787 For unfoldings we try to do the job lazily, so that we never type check
788 an unfolding that isn't going to be looked at.
791 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
794 tcIfaceExpr expr `thenM` \ core_expr' ->
796 -- Check for type consistency in the unfolding
797 ifOptM Opt_DoCoreLinting (
798 get_in_scope_ids `thenM` \ in_scope ->
799 case lintUnfolding noSrcLoc in_scope core_expr' of
800 Nothing -> returnM ()
801 Just fail_msg -> pprPanic "Iface Lint failure" (doc <+> fail_msg)
806 doc = text "Unfolding of" <+> ppr name
807 get_in_scope_ids -- Urgh; but just for linting
809 do { env <- getGblEnv
810 ; case if_rec_types env of {
811 Nothing -> return [] ;
812 Just (_, get_env) -> do
813 { type_env <- get_env
814 ; return (typeEnvIds type_env) }}}
819 %************************************************************************
821 Getting from Names to TyThings
823 %************************************************************************
826 tcIfaceGlobal :: Name -> IfL TyThing
828 | Just thing <- wiredInNameTyThing_maybe name
829 -- Wired-in things include TyCons, DataCons, and Ids
830 = do { loadWiredInHomeIface name; return thing }
831 -- Even though we are in an interface file, we want to make
832 -- sure its instances are loaded (imagine f :: Double -> Double)
833 -- and its RULES are loaded too
835 = do { (eps,hpt) <- getEpsAndHpt
836 ; case lookupType hpt (eps_PTE eps) name of {
837 Just thing -> return thing ;
841 ; case if_rec_types env of {
842 Just (mod, get_type_env)
843 | nameIsLocalOrFrom mod name
844 -> do -- It's defined in the module being compiled
845 { type_env <- setLclEnv () get_type_env -- yuk
846 ; case lookupNameEnv type_env name of
847 Just thing -> return thing
848 Nothing -> pprPanic "tcIfaceGlobal (local): not found:"
849 (ppr name $$ ppr type_env) }
853 { mb_thing <- importDecl name -- It's imported; go get it
855 Failed err -> failIfM err
856 Succeeded thing -> return thing
859 tcIfaceTyCon :: IfaceTyCon -> IfL TyCon
860 tcIfaceTyCon IfaceIntTc = tcWiredInTyCon intTyCon
861 tcIfaceTyCon IfaceBoolTc = tcWiredInTyCon boolTyCon
862 tcIfaceTyCon IfaceCharTc = tcWiredInTyCon charTyCon
863 tcIfaceTyCon IfaceListTc = tcWiredInTyCon listTyCon
864 tcIfaceTyCon IfacePArrTc = tcWiredInTyCon parrTyCon
865 tcIfaceTyCon (IfaceTupTc bx ar) = tcWiredInTyCon (tupleTyCon bx ar)
866 tcIfaceTyCon (IfaceTc ext_nm) = do { name <- lookupIfaceExt ext_nm
867 ; thing <- tcIfaceGlobal name
868 ; return (check_tc (tyThingTyCon thing)) }
871 check_tc tc = case toIfaceTyCon (error "urk") tc of
873 other -> pprTrace "check_tc" (ppr tc) tc
878 -- Even though we are in an interface file, we want to make
879 -- sure the instances and RULES of this tycon are loaded
880 -- Imagine: f :: Double -> Double
881 tcWiredInTyCon :: TyCon -> IfL TyCon
882 tcWiredInTyCon tc = do { loadWiredInHomeIface (tyConName tc)
885 tcIfaceClass :: IfaceExtName -> IfL Class
886 tcIfaceClass rdr_name = do { name <- lookupIfaceExt rdr_name
887 ; thing <- tcIfaceGlobal name
888 ; return (tyThingClass thing) }
890 tcIfaceDataCon :: IfaceExtName -> IfL DataCon
891 tcIfaceDataCon gbl = do { name <- lookupIfaceExt gbl
892 ; thing <- tcIfaceGlobal name
894 ADataCon dc -> return dc
895 other -> pprPanic "tcIfaceExtDC" (ppr gbl $$ ppr name$$ ppr thing) }
897 tcIfaceExtId :: IfaceExtName -> IfL Id
898 tcIfaceExtId gbl = do { name <- lookupIfaceExt gbl
899 ; thing <- tcIfaceGlobal name
902 other -> pprPanic "tcIfaceExtId" (ppr gbl $$ ppr name$$ ppr thing) }
905 %************************************************************************
909 %************************************************************************
912 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
913 bindIfaceBndr (IfaceIdBndr bndr) thing_inside
914 = bindIfaceId bndr thing_inside
915 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
916 = bindIfaceTyVar bndr thing_inside
918 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
919 bindIfaceBndrs [] thing_inside = thing_inside []
920 bindIfaceBndrs (b:bs) thing_inside
921 = bindIfaceBndr b $ \ b' ->
922 bindIfaceBndrs bs $ \ bs' ->
923 thing_inside (b':bs')
925 -----------------------
926 bindIfaceId :: (OccName, IfaceType) -> (Id -> IfL a) -> IfL a
927 bindIfaceId (occ, ty) thing_inside
928 = do { name <- newIfaceName occ
929 ; ty' <- tcIfaceType ty
930 ; let { id = mkLocalId name ty' }
931 ; extendIfaceIdEnv [id] (thing_inside id) }
933 bindIfaceIds :: [(OccName, IfaceType)] -> ([Id] -> IfL a) -> IfL a
934 bindIfaceIds bndrs thing_inside
935 = do { names <- newIfaceNames occs
936 ; tys' <- mappM tcIfaceType tys
937 ; let { ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys' }
938 ; extendIfaceIdEnv ids (thing_inside ids) }
940 (occs,tys) = unzip bndrs
943 -----------------------
944 newExtCoreBndr :: (OccName, IfaceType) -> IfL Id
945 newExtCoreBndr (occ, ty)
946 = do { mod <- getIfModule
947 ; name <- newGlobalBinder mod occ Nothing noSrcLoc
948 ; ty' <- tcIfaceType ty
949 ; return (mkLocalId name ty') }
951 -----------------------
952 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
953 bindIfaceTyVar (occ,kind) thing_inside
954 = do { name <- newIfaceName occ
955 ; let tyvar = mk_iface_tyvar name kind
956 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
958 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
959 bindIfaceTyVars bndrs thing_inside
960 = do { names <- newIfaceNames occs
961 ; let tyvars = zipWith mk_iface_tyvar names kinds
962 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
964 (occs,kinds) = unzip bndrs
966 mk_iface_tyvar name kind = mkTyVar name kind