2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[TcIfaceSig]{Type checking of type signatures in interface files}
8 tcImportDecl, typecheckIface,
9 tcIfaceKind, loadImportedInsts, loadImportedRules,
12 #include "HsVersions.h"
15 import LoadIface ( loadHomeInterface, predInstGates )
16 import IfaceEnv ( lookupIfaceTop, newGlobalBinder, lookupOrig,
17 extendIfaceIdEnv, extendIfaceTyVarEnv, newIPName,
18 tcIfaceTyVar, tcIfaceTyCon, tcIfaceClass, tcIfaceExtId,
19 tcIfaceDataCon, tcIfaceLclId,
20 newIfaceName, newIfaceNames )
21 import BuildTyCl ( buildSynTyCon, buildAlgTyCon, buildDataCon, buildClass )
23 import Type ( Kind, openTypeKind, liftedTypeKind,
24 unliftedTypeKind, mkArrowKind, splitTyConApp,
25 mkTyVarTys, mkGenTyConApp, mkTyVarTys, ThetaType )
26 import TypeRep ( Type(..), PredType(..) )
27 import TyCon ( TyCon, tyConName )
28 import HscTypes ( ExternalPackageState(..), PackageInstEnv, PackageRuleBase,
29 HscEnv, TyThing(..), implicitTyThings, typeEnvIds,
30 ModIface(..), ModDetails(..), InstPool, Dependencies(..),
31 TypeEnv, mkTypeEnv, extendTypeEnvList, lookupTypeEnv,
32 DeclPool, RulePool, Pool(..), Gated, addRuleToPool )
33 import InstEnv ( extendInstEnv )
35 import PprCore ( pprIdRules )
36 import Rules ( extendRuleBaseList )
37 import CoreUtils ( exprType )
39 import CoreLint ( lintUnfolding )
40 import WorkWrap ( mkWrapper )
41 import InstEnv ( DFunId )
42 import Id ( Id, mkVanillaGlobal, mkLocalId )
43 import MkId ( mkFCallId )
44 import IdInfo ( IdInfo, CafInfo(..), WorkerInfo(..),
45 setUnfoldingInfoLazily, setAllStrictnessInfo, setWorkerInfo,
46 setArityInfo, setInlinePragInfo, setCafInfo,
47 vanillaIdInfo, newStrictnessInfo )
48 import Class ( Class )
49 import TyCon ( DataConDetails(..), tyConDataCons, tyConTyVars, isTupleTyCon, mkForeignTyCon )
50 import DataCon ( dataConWorkId, dataConExistentialTyVars, dataConArgTys )
51 import TysWiredIn ( tupleCon )
52 import Var ( TyVar, mkTyVar, tyVarKind )
53 import Name ( Name, NamedThing(..), nameModuleName, nameModule, nameOccName,
54 isWiredInName, wiredInNameTyThing_maybe, nameParent )
56 import OccName ( OccName )
57 import Module ( Module, ModuleName, moduleName )
58 import UniqSupply ( initUs_ )
60 import SrcLoc ( noSrcLoc )
61 import Util ( zipWithEqual, dropList, equalLength )
62 import Maybes ( expectJust )
63 import CmdLineOpts ( DynFlag(..) )
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 -> IfG TyThing
111 -- Get the TyThing for this Name from an interface file
114 -- Make sure the interface is loaded
115 ; let { nd_doc = ptext SLIT("Need decl for") <+> ppr name }
116 ; traceIf (nd_doc <+> char '{') -- Brace matches the later message
117 ; loadHomeInterface nd_doc name
119 -- Get the real name of the thing, with a correct nameParent field.
120 -- Before the interface is loaded, we may have a non-committal 'Nothing'
121 -- in the namePareent field (made up by IfaceEnv.lookupOrig), but
122 -- loading the interface updates the name cache.
123 -- We need the right nameParent field in getThing
124 ; real_name <- lookupOrig (nameModuleName name) (nameOccName name)
126 -- Get the decl out of the EPS
127 ; main_thing <- ASSERT( real_name == name ) -- Unique should not change!
130 -- Record the import in the type env,
131 -- slurp any rules it allows in
132 ; recordImportOf main_thing
134 ; let { extra | getName main_thing == real_name = empty
135 | otherwise = brackets (ptext SLIT("when seeking") <+> ppr real_name) }
136 ; traceIf (ptext SLIT(" ...imported decl for") <+> ppr main_thing <+> extra <+> char '}')
139 -- Look up the wanted Name in the type envt; it might be
140 -- one of the subordinate members of the input thing
141 ; if real_name == getName main_thing
142 then return main_thing
145 ; return (expectJust "tcImportDecl" $
146 lookupTypeEnv (eps_PTE eps) real_name) }}
148 recordImportOf :: TyThing -> IfG ()
149 -- Update the EPS to record the import of the Thing
150 -- (a) augment the type environment; this is done even for wired-in
151 -- things, so that we don't go through this rigmarole a second time
152 -- (b) slurp in any rules to maintain the invariant that any rule
153 -- whose gates are all in the type envt, is in eps_rule_base
156 = do { new_things <- updateEps (\ eps ->
157 let { new_things = thing : implicitTyThings thing
158 ; new_type_env = extendTypeEnvList (eps_PTE eps) new_things
159 -- NB: opportunity for a very subtle loop here!
160 -- If working out what the implicitTyThings are involves poking
161 -- any of the fork'd thunks in 'thing', then here's what happens
162 -- * recordImportOf succeed, extending type-env with a thunk
163 -- * the next guy to pull on type-env forces the thunk
164 -- * which pokes the suspended forks
165 -- * which, to execute, need to consult type-env (to check
166 -- entirely unrelated types, perhaps)
168 in (eps { eps_PTE = new_type_env }, new_things)
170 ; traceIf (text "tcImport: extend type env" <+> ppr new_things)
173 getThing :: Name -> IfG TyThing
174 -- Find and typecheck the thing; the Name might be a "subordinate name"
175 -- of the "main thing" (e.g. the constructor of a data type declaration)
176 -- The Thing we return is the parent "main thing"
179 | Just thing <- wiredInNameTyThing_maybe name
182 | otherwise = do -- The normal case, not wired in
183 { -- Get the decl from the pool
184 decl <- updateEps (\ eps ->
186 (decls', decl) = selectDecl (eps_decls eps) name
188 (eps { eps_decls = decls' }, decl))
191 -- Side-effects EPS by faulting in any needed decls
192 -- (via nested calls to tcImportDecl)
193 ; initIfaceLcl (nameModuleName name) (tcIfaceDecl decl) }
196 selectDecl :: DeclPool -> Name -> (DeclPool, IfaceDecl)
197 -- Use nameParent to get the parent name of the thing
198 selectDecl (Pool decls_map n_in n_out) name
199 = (Pool decls' n_in (n_out+1), decl)
201 main_name = nameParent name
202 decl = case lookupNameEnv decls_map main_name of
203 Nothing -> pprPanic "selectDecl" (ppr main_name <+> ppr name) ;
206 decls' = delFromNameEnv decls_map main_name
209 %************************************************************************
213 %************************************************************************
216 typecheckIface :: ModIface -> IfG ModDetails
217 -- Used when we decide not to recompile, but intead to use the
218 -- interface to construct the type environment for the module
220 = initIfaceLcl (moduleName (mi_module iface)) $
221 do { ty_things <- mapM (tcIfaceDecl . snd) (mi_decls iface)
222 ; rules <- mapM tcIfaceRule (mi_rules iface)
223 ; dfuns <- mapM tcIfaceInst (mi_insts iface)
224 ; return (ModDetails { md_types = mkTypeEnv ty_things,
226 md_rules = rules }) }
230 %************************************************************************
232 Type and class declarations
234 %************************************************************************
236 When typechecking a data type decl, we *lazily* (via forkM) typecheck
237 the constructor argument types. This is in the hope that we may never
238 poke on those argument types, and hence may never need to load the
239 interface files for types mentioned in the arg types.
242 data Foo.S = MkS Baz.T
243 Mabye we can get away without even loading the interface for Baz!
245 This is not just a performance thing. Suppose we have
246 data Foo.S = MkS Baz.T
247 data Baz.T = MkT Foo.S
248 (in different interface files, of course).
249 Now, first we load and typecheck Foo.S, and add it to the type envt.
250 If we do explore MkS's argument, we'll load and typecheck Baz.T.
251 If we explore MkT's argument we'll find Foo.S already in the envt.
253 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
254 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
255 which isn't done yet.
257 All very cunning. However, there is a rather subtle gotcha which bit
258 me when developing this stuff. When we typecheck the decl for S, we
259 extend the type envt with S, MkS, and all its implicit Ids. Suppose
260 (a bug, but it happened) that the list of implicit Ids depended in
261 turn on the constructor arg types. Then the following sequence of
263 * we build a thunk <t> for the constructor arg tys
264 * we build a thunk for the extended type environment (depends on <t>)
265 * we write the extended type envt into the global EPS mutvar
267 Now we look something up in the type envt
269 * which reads the global type envt out of the global EPS mutvar
270 * but that depends in turn on <t>
272 It's subtle, because, it'd work fine if we typechecked the constructor args
273 eagerly -- they don't need the extended type envt. They just get the extended
274 type envt by accident, because they look at it later.
276 What this means is that the implicitTyThings MUST NOT DEPEND on any of
281 tcIfaceDecl :: IfaceDecl -> IfL TyThing
283 tcIfaceDecl (IfaceId {ifName = occ_name, ifType = iface_type, ifIdInfo = info})
284 = do { name <- lookupIfaceTop occ_name
285 ; ty <- tcIfaceType iface_type
286 ; info <- tcIdInfo name ty info
287 ; return (AnId (mkVanillaGlobal name ty info)) }
289 tcIfaceDecl (IfaceData {ifND = new_or_data, ifName = occ_name,
290 ifTyVars = tv_bndrs, ifCtxt = rdr_ctxt,
292 ifVrcs = arg_vrcs, ifRec = is_rec,
293 ifGeneric = want_generic })
294 = do { tc_name <- lookupIfaceTop occ_name
295 ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
297 { traceIf (text "tcIfaceDecl" <+> ppr rdr_ctxt)
299 ; ctxt <- forkM (ptext SLIT("Ctxt of data decl") <+> ppr tc_name) $
301 -- The reason for laziness here is to postpone
302 -- looking at the context, because the class may not
303 -- be in the type envt yet. E.g.
304 -- class Real a where { toRat :: a -> Ratio Integer }
305 -- data (Real a) => Ratio a = ...
306 -- We suck in the decl for Real, and type check it, which sucks
307 -- in the data type Ratio; but we must postpone typechecking the
310 ; tycon <- fixM ( \ tycon -> do
311 { cons <- tcIfaceDataCons tycon tyvars ctxt rdr_cons
312 ; tycon <- buildAlgTyCon new_or_data tc_name tyvars ctxt cons
313 arg_vrcs is_rec want_generic
316 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
317 ; return (ATyCon tycon)
320 tcIfaceDecl (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
321 ifSynRhs = rdr_rhs_ty, ifVrcs = arg_vrcs})
322 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
323 { tc_name <- lookupIfaceTop occ_name
324 ; rhs_ty <- tcIfaceType rdr_rhs_ty
325 ; return (ATyCon (buildSynTyCon tc_name tyvars rhs_ty arg_vrcs))
328 tcIfaceDecl (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name, ifTyVars = tv_bndrs,
329 ifFDs = rdr_fds, ifSigs = rdr_sigs,
330 ifVrcs = tc_vrcs, ifRec = tc_isrec })
331 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
332 { cls_name <- lookupIfaceTop occ_name
333 ; ctxt <- tcIfaceCtxt rdr_ctxt
334 ; sigs <- mappM tc_sig rdr_sigs
335 ; fds <- mappM tc_fd rdr_fds
336 ; cls <- buildClass cls_name tyvars ctxt fds sigs tc_isrec tc_vrcs
337 ; return (AClass cls) }
339 tc_sig (IfaceClassOp occ dm rdr_ty)
340 = do { op_name <- lookupIfaceTop occ
341 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
342 -- Must be done lazily for just the same reason as the
343 -- context of a data decl: the type sig might mention the
344 -- class being defined
345 ; return (op_name, dm, op_ty) }
347 mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
349 tc_fd (tvs1, tvs2) = do { tvs1' <- mappM tcIfaceTyVar tvs1
350 ; tvs2' <- mappM tcIfaceTyVar tvs2
351 ; return (tvs1', tvs2') }
353 tcIfaceDecl (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
354 = do { name <- lookupIfaceTop rdr_name
355 ; return (ATyCon (mkForeignTyCon name ext_name
356 liftedTypeKind 0 [])) }
358 tcIfaceDataCons tycon tyvars ctxt Unknown
361 tcIfaceDataCons tycon tyvars ctxt (DataCons cs)
362 = mappM tc_con_decl cs `thenM` \ data_cons ->
363 returnM (DataCons data_cons)
365 tc_con_decl (IfaceConDecl occ ex_tvs ex_ctxt args stricts field_lbls)
366 = bindIfaceTyVars ex_tvs $ \ ex_tyvars -> do
367 { name <- lookupIfaceTop occ
368 ; ex_theta <- tcIfaceCtxt ex_ctxt -- Laziness seems not worth the bother here
370 -- Read the argument types, but lazily to avoid faulting in
371 -- the component types unless they are really needed
372 ; arg_tys <- forkM (mk_doc name args) (mappM tcIfaceType args) ;
374 ; lbl_names <- mappM lookupIfaceTop field_lbls
376 ; buildDataCon name stricts lbl_names
377 tyvars ctxt ex_tyvars ex_theta
380 mk_doc con_name args = ptext SLIT("Constructor") <+> sep [ppr con_name, ppr args]
384 %************************************************************************
388 %************************************************************************
390 The gating story for instance declarations
391 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
392 When we are looking for a dict (C t1..tn), we slurp in instance decls for
394 mention at least one of the type constructors
395 at the roots of t1..tn
397 Why "at least one" rather than "all"? Because functional dependencies
398 complicate the picture. Consider
399 class C a b | a->b where ...
400 instance C Foo Baz where ...
401 Here, the gates are really only C and Foo, *not* Baz.
402 That is, if C and Foo are visible, even if Baz isn't, we must
403 slurp the decl, even if Baz is thus far completely unknown to the
406 Why "roots of the types"? Reason is overlap. For example, suppose there
407 are interfaces in the pool for
411 Then, if we are trying to resolve (C Int x), we need (a)
412 if we are trying to resolve (C x [y]), we need *both* (b) and (c),
413 even though T is not involved yet, so that we spot the overlap.
416 loadImportedInsts :: Class -> [Type] -> TcM PackageInstEnv
417 loadImportedInsts cls tys
418 = do { -- Get interfaces for wired-in things, such as Integer
419 -- Any non-wired-in tycons will already be loaded, else
420 -- we couldn't have them in the Type
421 ; this_mod <- getModule
422 ; let { (cls_gate, tc_gates) = predInstGates cls tys
423 ; imp_wi n = isWiredInName n && this_mod /= nameModule n
424 ; wired_tcs = filter imp_wi tc_gates }
425 -- Wired-in tycons not from this module. The "this-module"
426 -- test bites only when compiling Base etc, because loadHomeInterface
427 -- barfs if it's asked to load a non-existent interface
428 ; if null wired_tcs then returnM ()
429 else initIfaceTcRn (mapM_ (loadHomeInterface wired_doc) wired_tcs)
431 ; eps_var <- getEpsVar
432 ; eps <- readMutVar eps_var
434 -- Suck in the instances
435 ; let { (inst_pool', iface_insts)
436 = selectInsts (eps_insts eps) cls_gate tc_gates }
438 -- Empty => finish up rapidly, without writing to eps
439 ; if null iface_insts then
440 return (eps_inst_env eps)
442 { writeMutVar eps_var (eps {eps_insts = inst_pool'})
444 -- Typecheck the new instances
445 ; dfuns <- initIfaceTcRn (mappM tc_inst iface_insts)
447 -- And put them in the package instance environment
448 ; updateEps ( \ eps ->
450 inst_env' = foldl extendInstEnv (eps_inst_env eps) dfuns
452 (eps { eps_inst_env = inst_env' }, inst_env')
455 wired_doc = ptext SLIT("Need home inteface for wired-in thing")
457 tc_inst (mod, inst) = initIfaceLcl mod (tcIfaceInst inst)
459 tcIfaceInst :: IfaceInst -> IfL DFunId
460 tcIfaceInst (IfaceInst { ifDFun = dfun_occ })
461 = tcIfaceExtId (LocalTop dfun_occ)
463 selectInsts :: InstPool -> Name -> [Name] -> (InstPool, [(ModuleName, IfaceInst)])
464 selectInsts pool@(Pool insts n_in n_out) cls tycons
465 = (Pool insts' n_in (n_out + length iface_insts), iface_insts)
467 (insts', iface_insts)
468 = case lookupNameEnv insts cls of {
469 Nothing -> (insts, []) ;
472 case foldl choose ([],[]) gated_insts of {
473 (_, []) -> (insts, []) ; -- None picked
474 (gated_insts', iface_insts') ->
476 (extendNameEnv insts cls gated_insts', iface_insts') }}
478 -- Reverses the gated decls, but that doesn't matter
479 choose (gis, decls) (gates, decl)
480 | any (`elem` tycons) gates = (gis, decl:decls)
481 | otherwise = ((gates,decl) : gis, decls)
484 %************************************************************************
488 %************************************************************************
490 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
491 are in the type environment. However, remember that typechecking a Rule may
492 (as a side effect) augment the type envt, and so we may need to iterate the process.
495 loadImportedRules :: HscEnv -> Dependencies -> IO PackageRuleBase
496 loadImportedRules hsc_env deps
497 = initIfaceIO hsc_env deps $ do
499 if_rules <- updateEps (\ eps ->
500 let { (new_pool, if_rules) = selectRules (eps_rules eps) (eps_PTE eps) }
501 in (eps { eps_rules = new_pool }, if_rules) )
503 ; let tc_rule (mod, rule) = initIfaceLcl mod (tcIfaceRule rule)
504 ; core_rules <- mapM tc_rule if_rules
507 ; traceIf (ptext SLIT("Importing rules:") <+> pprIdRules core_rules)
509 -- Update the rule base and return it
510 ; updateEps (\ eps ->
511 let { new_rule_base = extendRuleBaseList (eps_rule_base eps) core_rules }
512 in (eps { eps_rule_base = new_rule_base }, new_rule_base)
515 -- Strictly speaking, at this point we should go round again, since
516 -- typechecking one set of rules may bring in new things which enable
517 -- some more rules to come in. But we call loadImportedRules several
518 -- times anyway, so I'm going to be lazy and ignore this.
522 selectRules :: RulePool -> TypeEnv -> (RulePool, [(ModuleName, IfaceRule)])
523 -- Not terribly efficient. Look at each rule in the pool to see if
524 -- all its gates are in the type env. If so, take it out of the pool.
525 -- If not, trim its gates for next time.
526 selectRules (Pool rules n_in n_out) type_env
527 = (Pool rules' n_in (n_out + length if_rules), if_rules)
529 (rules', if_rules) = foldl do_one ([], []) rules
531 do_one (pool, if_rules) (gates, rule)
532 | null gates' = (pool, rule:if_rules)
533 | otherwise = ((gates',rule) : pool, if_rules)
535 gates' = filter (`elemNameEnv` type_env) gates
538 tcIfaceRule :: IfaceRule -> IfL IdCoreRule
539 tcIfaceRule (IfaceRule {ifRuleName = rule_name, ifActivation = act, ifRuleBndrs = bndrs,
540 ifRuleHead = fn_rdr, ifRuleArgs = args, ifRuleRhs = rhs })
541 = bindIfaceBndrs bndrs $ \ bndrs' ->
542 do { fn <- tcIfaceExtId fn_rdr
543 ; args' <- mappM tcIfaceExpr args
544 ; rhs' <- tcIfaceExpr rhs
545 ; returnM (fn, (Rule rule_name act bndrs' args' rhs')) }
547 tcIfaceRule (IfaceBuiltinRule fn_rdr core_rule)
548 = do { fn <- tcIfaceExtId fn_rdr
549 ; returnM (fn, core_rule) }
553 %************************************************************************
557 %************************************************************************
560 tcIfaceKind :: IfaceKind -> Kind
561 tcIfaceKind IfaceOpenTypeKind = openTypeKind
562 tcIfaceKind IfaceLiftedTypeKind = liftedTypeKind
563 tcIfaceKind IfaceUnliftedTypeKind = unliftedTypeKind
564 tcIfaceKind (IfaceFunKind k1 k2) = mkArrowKind (tcIfaceKind k1) (tcIfaceKind k2)
566 -----------------------------------------
567 tcIfaceType :: IfaceType -> IfL Type
568 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
569 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
570 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
571 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkGenTyConApp tc' ts') }
572 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
573 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
575 tcIfaceTypes tys = mapM tcIfaceType tys
577 -----------------------------------------
578 tcIfacePredType :: IfacePredType -> IfL PredType
579 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
580 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
582 -----------------------------------------
583 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
584 tcIfaceCtxt sts = mappM tcIfacePredType sts
588 %************************************************************************
592 %************************************************************************
595 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
596 tcIfaceExpr (IfaceType ty)
597 = tcIfaceType ty `thenM` \ ty' ->
600 tcIfaceExpr (IfaceLcl name)
601 = tcIfaceLclId name `thenM` \ id ->
604 tcIfaceExpr (IfaceExt gbl)
605 = tcIfaceExtId gbl `thenM` \ id ->
608 tcIfaceExpr (IfaceLit lit)
611 tcIfaceExpr (IfaceFCall cc ty)
612 = tcIfaceType ty `thenM` \ ty' ->
613 newUnique `thenM` \ u ->
614 returnM (Var (mkFCallId u cc ty'))
616 tcIfaceExpr (IfaceTuple boxity args)
617 = mappM tcIfaceExpr args `thenM` \ args' ->
619 -- Put the missing type arguments back in
620 con_args = map (Type . exprType) args' ++ args'
622 returnM (mkApps (Var con_id) con_args)
625 con_id = dataConWorkId (tupleCon boxity arity)
628 tcIfaceExpr (IfaceLam bndr body)
629 = bindIfaceBndr bndr $ \ bndr' ->
630 tcIfaceExpr body `thenM` \ body' ->
631 returnM (Lam bndr' body')
633 tcIfaceExpr (IfaceApp fun arg)
634 = tcIfaceExpr fun `thenM` \ fun' ->
635 tcIfaceExpr arg `thenM` \ arg' ->
636 returnM (App fun' arg')
638 tcIfaceExpr (IfaceCase scrut case_bndr alts)
639 = tcIfaceExpr scrut `thenM` \ scrut' ->
640 newIfaceName case_bndr `thenM` \ case_bndr_name ->
642 scrut_ty = exprType scrut'
643 case_bndr' = mkLocalId case_bndr_name scrut_ty
644 tc_app = splitTyConApp scrut_ty
645 -- NB: Won't always succeed (polymoprhic case)
646 -- but won't be demanded in those cases
647 -- NB: not tcSplitTyConApp; we are looking at Core here
648 -- look through non-rec newtypes to find the tycon that
649 -- corresponds to the datacon in this case alternative
651 extendIfaceIdEnv [case_bndr'] $
652 mappM (tcIfaceAlt tc_app) alts `thenM` \ alts' ->
653 returnM (Case scrut' case_bndr' alts')
655 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body)
656 = tcIfaceExpr rhs `thenM` \ rhs' ->
657 bindIfaceId bndr $ \ bndr' ->
658 tcIfaceExpr body `thenM` \ body' ->
659 returnM (Let (NonRec bndr' rhs') body')
661 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
662 = bindIfaceIds bndrs $ \ bndrs' ->
663 mappM tcIfaceExpr rhss `thenM` \ rhss' ->
664 tcIfaceExpr body `thenM` \ body' ->
665 returnM (Let (Rec (bndrs' `zip` rhss')) body')
667 (bndrs, rhss) = unzip pairs
669 tcIfaceExpr (IfaceNote note expr)
670 = tcIfaceExpr expr `thenM` \ expr' ->
672 IfaceCoerce to_ty -> tcIfaceType to_ty `thenM` \ to_ty' ->
673 returnM (Note (Coerce to_ty'
674 (exprType expr')) expr')
675 IfaceInlineCall -> returnM (Note InlineCall expr')
676 IfaceInlineMe -> returnM (Note InlineMe expr')
677 IfaceSCC cc -> returnM (Note (SCC cc) expr')
678 IfaceCoreNote n -> returnM (Note (CoreNote n) expr')
680 -------------------------
681 tcIfaceAlt _ (IfaceDefault, names, rhs)
682 = ASSERT( null names )
683 tcIfaceExpr rhs `thenM` \ rhs' ->
684 returnM (DEFAULT, [], rhs')
686 tcIfaceAlt _ (IfaceLitAlt lit, names, rhs)
687 = ASSERT( null names )
688 tcIfaceExpr rhs `thenM` \ rhs' ->
689 returnM (LitAlt lit, [], rhs')
691 -- A case alternative is made quite a bit more complicated
692 -- by the fact that we omit type annotations because we can
693 -- work them out. True enough, but its not that easy!
694 tcIfaceAlt (tycon, inst_tys) (IfaceDataAlt data_occ, arg_occs, rhs)
696 tycon_mod = nameModuleName (tyConName tycon)
698 tcIfaceDataCon (ExtPkg tycon_mod data_occ) `thenM` \ con ->
699 newIfaceNames arg_occs `thenM` \ arg_names ->
701 ex_tyvars = dataConExistentialTyVars con
702 main_tyvars = tyConTyVars tycon
703 ex_tyvars' = [mkTyVar name (tyVarKind tv) | (name,tv) <- arg_names `zip` ex_tyvars]
704 ex_tys' = mkTyVarTys ex_tyvars'
705 arg_tys = dataConArgTys con (inst_tys ++ ex_tys')
706 id_names = dropList ex_tyvars arg_names
709 | not (equalLength id_names arg_tys)
710 = pprPanic "tcIfaceAlts" (ppr (con, arg_names, rhs) $$
711 (ppr main_tyvars <+> ppr ex_tyvars) $$
715 = zipWithEqual "tcIfaceAlts" mkLocalId id_names arg_tys
717 ASSERT2( con `elem` tyConDataCons tycon && equalLength inst_tys main_tyvars,
718 ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon) $$ ppr arg_tys $$ ppr main_tyvars )
719 extendIfaceTyVarEnv ex_tyvars' $
720 extendIfaceIdEnv arg_ids $
721 tcIfaceExpr rhs `thenM` \ rhs' ->
722 returnM (DataAlt con, ex_tyvars' ++ arg_ids, rhs')
724 tcIfaceAlt (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
725 = newIfaceNames arg_occs `thenM` \ arg_names ->
727 [con] = tyConDataCons tycon
728 arg_ids = zipWithEqual "tcIfaceAlts" mkLocalId arg_names inst_tys
730 ASSERT( isTupleTyCon tycon )
731 extendIfaceIdEnv arg_ids $
732 tcIfaceExpr rhs `thenM` \ rhs' ->
733 returnM (DataAlt con, arg_ids, rhs')
738 tcExtCoreBindings :: Module -> [IfaceBinding] -> IfL [CoreBind] -- Used for external core
739 tcExtCoreBindings mod [] = return []
740 tcExtCoreBindings mod (b:bs) = do_one mod b (tcExtCoreBindings mod bs)
742 do_one :: Module -> IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
743 do_one mod (IfaceNonRec bndr rhs) thing_inside
744 = do { rhs' <- tcIfaceExpr rhs
745 ; bndr' <- newExtCoreBndr mod bndr
746 ; extendIfaceIdEnv [bndr'] $ do
747 { core_binds <- thing_inside
748 ; return (NonRec bndr' rhs' : core_binds) }}
750 do_one mod (IfaceRec pairs) thing_inside
751 = do { bndrs' <- mappM (newExtCoreBndr mod) bndrs
752 ; extendIfaceIdEnv bndrs' $ do
753 { rhss' <- mappM tcIfaceExpr rhss
754 ; core_binds <- thing_inside
755 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
757 (bndrs,rhss) = unzip pairs
761 %************************************************************************
765 %************************************************************************
768 tcIdInfo name ty NoInfo = return vanillaIdInfo
769 tcIdInfo name ty DiscardedInfo = return vanillaIdInfo
770 tcIdInfo name ty (HasInfo iface_info)
771 = foldlM tcPrag init_info iface_info
773 -- Set the CgInfo to something sensible but uninformative before
774 -- we start; default assumption is that it has CAFs
775 init_info = vanillaIdInfo
777 tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
778 tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
779 tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
781 -- The next two are lazy, so they don't transitively suck stuff in
782 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
783 tcPrag info (HsUnfold inline_prag expr)
784 = tcPragExpr name expr `thenM` \ maybe_expr' ->
786 -- maybe_expr' doesn't get looked at if the unfolding
787 -- is never inspected; so the typecheck doesn't even happen
788 unfold_info = case maybe_expr' of
789 Nothing -> noUnfolding
790 Just expr' -> mkTopUnfolding expr'
792 returnM (info `setUnfoldingInfoLazily` unfold_info
793 `setInlinePragInfo` inline_prag)
797 tcWorkerInfo ty info wkr_name arity
798 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId (LocalTop wkr_name))
800 -- We return without testing maybe_wkr_id, but as soon as info is
801 -- looked at we will test it. That's ok, because its outside the
802 -- knot; and there seems no big reason to further defer the
803 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
804 -- over the unfolding until it's actually used does seem worth while.)
805 ; us <- newUniqueSupply
807 ; returnM (case mb_wkr_id of
809 Just wkr_id -> add_wkr_info us wkr_id info) }
811 doc = text "Worker for" <+> ppr wkr_name
812 add_wkr_info us wkr_id info
813 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
814 `setWorkerInfo` HasWorker wkr_id arity
816 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
818 -- We are relying here on strictness info always appearing
819 -- before worker info, fingers crossed ....
820 strict_sig = case newStrictnessInfo info of
822 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr_name)
825 For unfoldings we try to do the job lazily, so that we never type check
826 an unfolding that isn't going to be looked at.
829 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
832 tcIfaceExpr expr `thenM` \ core_expr' ->
834 -- Check for type consistency in the unfolding
835 ifOptM Opt_DoCoreLinting (
836 get_in_scope_ids `thenM` \ in_scope ->
837 case lintUnfolding noSrcLoc in_scope core_expr' of
838 Nothing -> returnM ()
839 Just fail_msg -> pprPanic "Iface Lint failure" (doc <+> fail_msg)
844 doc = text "Unfolding of" <+> ppr name
845 get_in_scope_ids -- Urgh; but just for linting
847 do { env <- getGblEnv
848 ; case if_rec_types env of {
849 Nothing -> return [] ;
850 Just (_, get_env) -> do
851 { type_env <- get_env
852 ; return (typeEnvIds type_env) }}}
857 %************************************************************************
861 %************************************************************************
864 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
865 bindIfaceBndr (IfaceIdBndr bndr) thing_inside
866 = bindIfaceId bndr thing_inside
867 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
868 = bindIfaceTyVar bndr thing_inside
870 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
871 bindIfaceBndrs [] thing_inside = thing_inside []
872 bindIfaceBndrs (b:bs) thing_inside
873 = bindIfaceBndr b $ \ b' ->
874 bindIfaceBndrs bs $ \ bs' ->
875 thing_inside (b':bs')
877 -----------------------
878 bindIfaceId :: (OccName, IfaceType) -> (Id -> IfL a) -> IfL a
879 bindIfaceId (occ, ty) thing_inside
880 = do { name <- newIfaceName occ
881 ; ty' <- tcIfaceType ty
882 ; let { id = mkLocalId name ty' }
883 ; extendIfaceIdEnv [id] (thing_inside id) }
885 bindIfaceIds :: [(OccName, IfaceType)] -> ([Id] -> IfL a) -> IfL a
886 bindIfaceIds bndrs thing_inside
887 = do { names <- newIfaceNames occs
888 ; tys' <- mappM tcIfaceType tys
889 ; let { ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys' }
890 ; extendIfaceIdEnv ids (thing_inside ids) }
892 (occs,tys) = unzip bndrs
895 -----------------------
896 newExtCoreBndr :: Module -> (OccName, IfaceType) -> IfL Id
897 newExtCoreBndr mod (occ, ty)
898 = do { name <- newGlobalBinder mod occ Nothing noSrcLoc
899 ; ty' <- tcIfaceType ty
900 ; return (mkLocalId name ty') }
902 -----------------------
903 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
904 bindIfaceTyVar (occ,kind) thing_inside
905 = do { name <- newIfaceName occ
906 ; let tyvar = mk_iface_tyvar name kind
907 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
909 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
910 bindIfaceTyVars bndrs thing_inside
911 = do { names <- newIfaceNames occs
912 ; let tyvars = zipWith mk_iface_tyvar names kinds
913 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
915 (occs,kinds) = unzip bndrs
917 mk_iface_tyvar name kind = mkTyVar name (tcIfaceKind kind)