import CoreSyn
-import DsCCall ( dsCCall, boxResult, unboxArg, wrapUnboxedValue )
+import DsCCall ( dsCCall, mkCCall, boxResult, unboxArg )
import DsMonad
import DsUtils
-import HsSyn ( ExtName(..), ForeignDecl(..), isDynamic, ForKind(..) )
+import HsSyn ( ExtName(..), ForeignDecl(..), isDynamicExtName, ForKind(..) )
+import HsDecls ( extNameStatic )
import CallConv
import TcHsSyn ( TypecheckedForeignDecl )
-import CoreUtils ( coreExprType )
-import Const ( Con(..), mkMachInt )
-import DataCon ( DataCon, dataConId )
-import Id ( Id, idType, idName, mkWildId, mkVanillaId )
-import Const ( Literal(..) )
-import Module ( Module )
+import CoreUtils ( exprType, mkInlineMe )
+import DataCon ( DataCon, dataConWrapId )
+import Id ( Id, idType, idName, mkWildId, mkVanillaId, mkSysLocal,
+ setInlinePragma )
+import IdInfo ( neverInlinePrag )
+import MkId ( mkWorkerId )
+import Literal ( Literal(..) )
+import Module ( Module, moduleUserString )
import Name ( mkGlobalName, nameModule, nameOccName, getOccString,
mkForeignExportOcc, isLocalName,
NamedThing(..), Provenance(..), ExportFlag(..)
)
-import PrelInfo ( deRefStablePtr_NAME, bindIO_NAME, makeStablePtr_NAME, realWorldPrimId )
-import Type ( splitAlgTyConApp_maybe,
+import Type ( unUsgTy, repType,
splitTyConApp_maybe, splitFunTys, splitForAllTys,
Type, mkFunTys, mkForAllTys, mkTyConApp,
- mkTyVarTy, mkFunTy, splitAppTy
+ mkTyVarTy, mkFunTy, splitAppTy, applyTy, funResultTy
)
-import PrimOp ( PrimOp(..) )
+import PprType ( {- instance Outputable Type -} )
+import PrimOp ( PrimOp(..), CCall(..), CCallTarget(..), dynamicTarget )
import Var ( TyVar )
import TysPrim ( realWorldStatePrimTy, addrPrimTy )
-import TysWiredIn ( unitTyCon, addrTy, stablePtrTyCon,
- unboxedTupleCon, addrDataCon
+import TysWiredIn ( unitTy, addrTy, stablePtrTyCon,
+ addrDataCon
)
-import Unique
+import Unique ( Uniquable(..), hasKey,
+ ioTyConKey, deRefStablePtrIdKey, returnIOIdKey,
+ bindIOIdKey, makeStablePtrIdKey
+ )
+import Maybes ( maybeToBool )
import Outputable
\end{code}
where
combine (acc_fi, acc_fe, acc_h, acc_c) fo@(ForeignDecl i imp_exp _ ext_nm cconv _)
| isForeignImport = -- foreign import (dynamic)?
- dsFImport i (idType i) uns ext_nm cconv `thenDs` \ b ->
- returnDs (b:acc_fi, acc_fe, acc_h, acc_c)
+ dsFImport i (idType i) uns ext_nm cconv `thenDs` \ bs ->
+ returnDs (bs ++ acc_fi, acc_fe, acc_h, acc_c)
| isForeignLabel =
dsFLabel i ext_nm `thenDs` \ b ->
returnDs (b:acc_fi, acc_fe, acc_h, acc_c)
- | isDynamic ext_nm =
+ | isDynamicExtName ext_nm =
dsFExportDynamic i (idType i) mod_name ext_nm cconv `thenDs` \ (fi,fe,h,c) ->
returnDs (fi:acc_fi, fe:acc_fe, h $$ acc_h, c $$ acc_c)
that on its RHS unboxes its arguments, performs the external call
(using the @CCallOp@ primop), before boxing the result up and returning it.
+However, we create a worker/wrapper pair, thus:
+
+ foreign import f :: Int -> IO Int
+==>
+ f x = IO ( \s -> case x of { I# x# ->
+ case fw s x# of { (# s1, y# #) ->
+ (# s1, I# y# #)}})
+
+ fw s x# = ccall f s x#
+
+The strictness/CPR analyser won't do this automatically because it doesn't look
+inside returned tuples; but inlining this wrapper is a Really Good Idea
+because it exposes the boxing to the call site.
+
+
\begin{code}
dsFImport :: Id
-> Type -- Type of foreign import.
-> Bool -- True <=> might cause Haskell GC
-> ExtName
-> CallConv
- -> DsM CoreBind
-dsFImport nm ty may_not_gc ext_name cconv =
- newSysLocalDs realWorldStatePrimTy `thenDs` \ old_s ->
- splitForeignTyDs ty `thenDs` \ (tvs, args, mbIoDataCon, io_res_ty) ->
- let
- the_state_arg
- | is_io_action = old_s
- | otherwise = realWorldPrimId
-
- arg_exprs = map (Var) args
-
- is_io_action =
- case mbIoDataCon of
- Nothing -> False
- _ -> True
+ -> DsM [CoreBind]
+dsFImport fn_id ty may_not_gc ext_name cconv
+ = let
+ (tvs, fun_ty) = splitForAllTys ty
+ (arg_tys, io_res_ty) = splitFunTys fun_ty
in
- mapAndUnzipDs unboxArg arg_exprs `thenDs` \ (unboxed_args, arg_wrappers) ->
- (if not is_io_action then
- newSysLocalDs realWorldStatePrimTy `thenDs` \ state_tok ->
- wrapUnboxedValue io_res_ty `thenDs` \ (ccall_result_ty, v, res_v) ->
- returnDs ( ccall_result_ty
- , \ prim_app -> Case prim_app (mkWildId ccall_result_ty)
- [(DataCon (unboxedTupleCon 2), [state_tok, v], res_v)])
- else
- boxResult io_res_ty) `thenDs` \ (final_result_ty, res_wrapper) ->
- (case ext_name of
- Dynamic -> getUniqueDs `thenDs` \ u ->
- returnDs (Right u)
- ExtName fs _ -> returnDs (Left fs)) `thenDs` \ lbl ->
- let
- val_args = Var the_state_arg : unboxed_args
- final_args = Type inst_ty : val_args
-
- -- A CCallOp has type (forall a. a), so we must instantiate
- -- it at the full type, including the state argument
- inst_ty = mkFunTys (map coreExprType val_args) final_result_ty
-
- the_ccall_op = CCallOp lbl False (not may_not_gc) cconv
-
- the_prim_app = mkPrimApp the_ccall_op (final_args :: [CoreArg])
+ newSysLocalsDs arg_tys `thenDs` \ args ->
+ mapAndUnzipDs unboxArg (map Var args) `thenDs` \ (val_args, arg_wrappers) ->
+ boxResult io_res_ty `thenDs` \ (ccall_result_ty, res_wrapper) ->
- body = foldr ($) (res_wrapper the_prim_app) arg_wrappers
-
- the_body
- | not is_io_action = body
- | otherwise = Lam old_s body
- in
- newSysLocalDs (coreExprType the_body) `thenDs` \ ds ->
+ getUniqueDs `thenDs` \ ccall_uniq ->
+ getUniqueDs `thenDs` \ work_uniq ->
let
- io_app =
- case mbIoDataCon of
- Nothing -> Var ds
- Just ioDataCon ->
- mkApps (Var (dataConId ioDataCon))
- [Type io_res_ty, Var ds]
-
- fo_rhs = mkLams (tvs ++ args)
- (mkDsLet (NonRec ds (the_body::CoreExpr)) io_app)
+ lbl = case ext_name of
+ Dynamic -> dynamicTarget
+ ExtName fs _ -> StaticTarget fs
+
+ -- Build the worker
+ work_arg_ids = [v | Var v <- val_args] -- All guaranteed to be vars
+ worker_ty = mkForAllTys tvs (mkFunTys (map idType work_arg_ids) ccall_result_ty)
+ the_ccall = CCall lbl False (not may_not_gc) cconv
+ the_ccall_app = mkCCall ccall_uniq the_ccall val_args ccall_result_ty
+ work_rhs = mkLams tvs (mkLams work_arg_ids the_ccall_app)
+ work_id = mkSysLocal SLIT("$wccall") work_uniq worker_ty
+
+ -- Build the wrapper
+ work_app = mkApps (mkVarApps (Var work_id) tvs) val_args
+ wrapper_body = foldr ($) (res_wrapper work_app) arg_wrappers
+ wrap_rhs = mkInlineMe (mkLams (tvs ++ args) wrapper_body)
in
- returnDs (NonRec nm fo_rhs)
+ returnDs [NonRec fn_id wrap_rhs, NonRec work_id work_rhs]
\end{code}
-Given the type of a foreign import declaration, split it up into
-its constituent parts.
-
-\begin{code}
-splitForeignTyDs :: Type -> DsM ([TyVar], [Id], Maybe DataCon, Type)
-splitForeignTyDs ty =
- newSysLocalsDs arg_tys `thenDs` \ ds_args ->
- case splitAlgTyConApp_maybe res_ty of
- Just (_,(io_res_ty:_),(ioCon:_)) -> -- .... -> IO t
- returnDs (tvs, ds_args, Just ioCon, io_res_ty)
- _ -> -- .... -> t
- returnDs (tvs, ds_args, Nothing, res_ty)
- where
- (arg_tys, res_ty) = splitFunTys sans_foralls
- (tvs, sans_foralls) = splitForAllTys ty
-
-\end{code}
-
-foreign labels
+Foreign labels
\begin{code}
dsFLabel :: Id -> ExtName -> DsM CoreBind
dsFLabel nm ext_name = returnDs (NonRec nm fo_rhs)
where
- fo_rhs = mkConApp addrDataCon [mkLit (MachLitLit enm addrPrimTy)]
- enm =
- case ext_name of
- ExtName f _ -> f
- Dynamic -> panic "dsFLabel: Dynamic - shouldn't ever happen."
-
+ fo_rhs = mkConApp addrDataCon [mkLit (MachLitLit addr addrPrimTy)]
+ enm = extNameStatic ext_name
+ addr = SLIT("(&") _APPEND_ enm _APPEND_ SLIT(")")
\end{code}
The function that does most of the work for `@foreign export@' declarations.
, SDoc
, SDoc
)
-dsFExport i ty mod_name ext_name cconv isDyn =
- getUniqueDs `thenDs` \ uniq ->
- getSrcLocDs `thenDs` \ src_loc ->
- let
- f_helper_glob = mkVanillaId helper_name helper_ty
- where
- name = idName i
- mod
- | isLocalName name = mod_name
- | otherwise = nameModule name
-
- occ = mkForeignExportOcc (nameOccName name)
- prov = LocalDef src_loc Exported
- helper_name = mkGlobalName uniq mod occ prov
- in
- newSysLocalsDs fe_arg_tys `thenDs` \ fe_args ->
+dsFExport fn_id ty mod_name ext_name cconv isDyn
+ = -- BUILD THE returnIO WRAPPER, if necessary
+ -- Look at the result type of the exported function, orig_res_ty
+ -- If it's IO t, return (\x.x, IO t, t)
+ -- If it's plain t, return (\x.returnIO x, IO t, t)
+ (case splitTyConApp_maybe orig_res_ty of
+ Just (ioTyCon, [res_ty])
+ -> ASSERT( ioTyCon `hasKey` ioTyConKey )
+ -- The function already returns IO t
+ returnDs (\body -> body, orig_res_ty, res_ty)
+
+ other -> -- The function returns t, so wrap the call in returnIO
+ dsLookupGlobalValue returnIOIdKey `thenDs` \ retIOId ->
+ returnDs (\body -> mkApps (Var retIOId) [Type orig_res_ty, body],
+ funResultTy (applyTy (idType retIOId) orig_res_ty),
+ -- We don't have ioTyCon conveniently to hand
+ orig_res_ty)
+
+ ) `thenDs` \ (return_io_wrapper, -- Either identity or returnIO
+ io_res_ty, -- IO t
+ res_ty) -> -- t
+
+
+ -- BUILD THE deRefStablePtr WRAPPER, if necessary
(if isDyn then
newSysLocalDs stbl_ptr_ty `thenDs` \ stbl_ptr ->
newSysLocalDs stbl_ptr_to_ty `thenDs` \ stbl_value ->
- dsLookupGlobalValue deRefStablePtr_NAME `thenDs` \ deRefStablePtrId ->
+ dsLookupGlobalValue deRefStablePtrIdKey `thenDs` \ deRefStablePtrId ->
+ dsLookupGlobalValue bindIOIdKey `thenDs` \ bindIOId ->
let
the_deref_app = mkApps (Var deRefStablePtrId)
[ Type stbl_ptr_to_ty, Var stbl_ptr ]
- in
- newSysLocalDs (coreExprType the_deref_app) `thenDs` \ x_deref_app ->
- dsLookupGlobalValue bindIO_NAME `thenDs` \ bindIOId ->
- newSysLocalDs (mkFunTy stbl_ptr_to_ty
- (mkTyConApp ioTyCon [res_ty])) `thenDs` \ x_cont ->
- let
- stbl_app = \ cont ->
- bindNonRec x_cont (mkLams [stbl_value] cont) $
- bindNonRec x_deref_app the_deref_app
- (mkApps (Var bindIOId)
- [ Type stbl_ptr_to_ty
- , Type res_ty
- , Var x_deref_app
- , Var x_cont])
+
+ stbl_app cont = mkApps (Var bindIOId)
+ [ Type stbl_ptr_to_ty
+ , Type res_ty
+ , the_deref_app
+ , mkLams [stbl_value] cont]
in
returnDs (stbl_value, stbl_app, stbl_ptr)
else
- returnDs (i,
+ returnDs (fn_id,
\ body -> body,
panic "stbl_ptr" -- should never be touched.
)) `thenDs` \ (i, getFun_wrapper, stbl_ptr) ->
- let
- wrapper_args
- | isDyn = stbl_ptr:fe_args
- | otherwise = fe_args
- wrapper_arg_tys
- | isDyn = stbl_ptr_ty:helper_arg_tys
- | otherwise = helper_arg_tys
- the_app =
- getFun_wrapper $
- mkApps (Var i) (map (Type . mkTyVarTy) tvs ++ map Var fe_args)
- in
- getModuleAndGroupDs `thenDs` \ (mod,_) ->
+ -- BUILD THE HELPER
+ getModuleDs `thenDs` \ mod ->
getUniqueDs `thenDs` \ uniq ->
+ getSrcLocDs `thenDs` \ src_loc ->
+ newSysLocalsDs fe_arg_tys `thenDs` \ fe_args ->
let
- the_body = mkLams (tvs ++ wrapper_args) the_app
+ wrapper_args | isDyn = stbl_ptr:fe_args
+ | otherwise = fe_args
+
+ wrapper_arg_tys | isDyn = stbl_ptr_ty:fe_arg_tys
+ | otherwise = fe_arg_tys
+
+ helper_ty = mkForAllTys tvs $
+ mkFunTys wrapper_arg_tys io_res_ty
+
+ f_helper_glob = mkVanillaId helper_name helper_ty
+ where
+ name = idName fn_id
+ mod
+ | isLocalName name = mod_name
+ | otherwise = nameModule name
- c_nm =
- case ext_name of
- ExtName fs _ -> fs
- Dynamic -> panic "dsFExport: Dynamic - shouldn't ever happen."
+ occ = mkForeignExportOcc (nameOccName name)
+ prov = LocalDef src_loc Exported
+ helper_name = mkGlobalName uniq mod occ prov
- (h_stub, c_stub) = fexportEntry c_nm f_helper_glob
- wrapper_arg_tys the_result_ty cconv isDyn
+ the_app = getFun_wrapper (return_io_wrapper (mkVarApps (Var i) (tvs ++ fe_args)))
+ the_body = mkLams (tvs ++ wrapper_args) the_app
+ c_nm = extNameStatic ext_name
+
+ (h_stub, c_stub) = fexportEntry (moduleUserString mod)
+ c_nm f_helper_glob
+ wrapper_arg_tys res_ty cconv isDyn
in
returnDs (NonRec f_helper_glob the_body, h_stub, c_stub)
where
-
(tvs,sans_foralls) = splitForAllTys ty
- (fe_arg_tys', io_res) = splitFunTys sans_foralls
-
-
- Just (ioTyCon, [res_ty]) = splitTyConApp_maybe io_res
+ (fe_arg_tys', orig_res_ty) = splitFunTys sans_foralls
(_, stbl_ptr_ty') = splitForAllTys stbl_ptr_ty
(_, stbl_ptr_to_ty) = splitAppTy stbl_ptr_ty'
- fe_arg_tys
- | isDyn = tail fe_arg_tys'
- | otherwise = fe_arg_tys'
-
- (stbl_ptr_ty, helper_arg_tys) =
- case fe_arg_tys' of
- (x:xs) | isDyn -> (x,xs)
- ls -> (error "stbl_ptr_ty", ls)
-
- helper_ty =
- mkForAllTys tvs $
- mkFunTys arg_tys io_res
- where
- arg_tys
- | isDyn = stbl_ptr_ty : helper_arg_tys
- | otherwise = helper_arg_tys
-
- the_result_ty =
- case splitTyConApp_maybe io_res of
- Just (_,[res_ty]) ->
- case splitTyConApp_maybe res_ty of
- Just (tc,_) | getUnique tc /= getUnique unitTyCon -> Just res_ty
- _ -> Nothing
- _ -> Nothing
-
+ fe_arg_tys | isDyn = tail fe_arg_tys'
+ | otherwise = fe_arg_tys'
+
+ stbl_ptr_ty | isDyn = head fe_arg_tys'
+ | otherwise = error "stbl_ptr_ty"
\end{code}
@foreign export dynamic@ lets you dress up Haskell IO actions
as a C function pointer). Useful for callbacks and stuff.
\begin{verbatim}
-foreign export stdcall f :: (Addr -> Int -> IO Int) -> IO Addr
+foreign export dynamic f :: (Addr -> Int -> IO Int) -> IO Addr
--- Haskell-visible constructor, which is generated from the
--- above:
+-- Haskell-visible constructor, which is generated from the above:
+-- SUP: No check for NULL from createAdjustor anymore???
f :: (Addr -> Int -> IO Int) -> IO Addr
-f cback = IO ( \ s1# ->
- case makeStablePtr# cback s1# of { StateAndStablePtr# s2# sp# ->
- case _ccall_ "mkAdjustor" sp# ``f_helper'' s2# of
- StateAndAddr# s3# a# ->
- case addr2Int# a# of
- 0# -> IOfail s# err
- _ ->
- let
- a :: Addr
- a = A# a#
- in
- IOok s3# a)
+f cback =
+ bindIO (makeStablePtr cback)
+ (\StablePtr sp# -> IO (\s1# ->
+ case _ccall_ createAdjustor cconv sp# ``f_helper'' s1# of
+ (# s2#, a# #) -> (# s2#, A# a# #)))
foreign export "f_helper" f_helper :: StablePtr (Addr -> Int -> IO Int) -> Addr -> Int -> IO Int
-- `special' foreign export that invokes the closure pointed to by the
newSysLocalDs ty `thenDs` \ fe_id ->
let
-- hack: need to get at the name of the C stub we're about to generate.
- fe_nm = toCName fe_id
+ fe_nm = moduleUserString mod_name ++ "_" ++ toCName fe_id
fe_ext_name = ExtName (_PK_ fe_nm) Nothing
in
dsFExport i export_ty mod_name fe_ext_name cconv True
`thenDs` \ (fe@(NonRec fe_helper fe_expr), h_code, c_code) ->
- newSysLocalDs arg_ty `thenDs` \ cback ->
- dsLookupGlobalValue makeStablePtr_NAME `thenDs` \ makeStablePtrId ->
+ newSysLocalDs arg_ty `thenDs` \ cback ->
+ dsLookupGlobalValue makeStablePtrIdKey `thenDs` \ makeStablePtrId ->
let
mk_stbl_ptr_app = mkApps (Var makeStablePtrId) [ Type arg_ty, Var cback ]
- mk_stbl_ptr_app_ty = coreExprType mk_stbl_ptr_app
in
- newSysLocalDs mk_stbl_ptr_app_ty `thenDs` \ x_mk_stbl_ptr_app ->
- dsLookupGlobalValue bindIO_NAME `thenDs` \ bindIOId ->
+ dsLookupGlobalValue bindIOIdKey `thenDs` \ bindIOId ->
newSysLocalDs (mkTyConApp stablePtrTyCon [arg_ty]) `thenDs` \ stbl_value ->
let
- stbl_app = \ x_cont cont ret_ty ->
- bindNonRec x_cont cont $
- bindNonRec x_mk_stbl_ptr_app mk_stbl_ptr_app $
- (mkApps (Var bindIOId)
- [ Type (mkTyConApp stablePtrTyCon [arg_ty])
- , Type ret_ty
- , Var x_mk_stbl_ptr_app
- , Var x_cont
- ])
+ stbl_app cont ret_ty
+ = mkApps (Var bindIOId)
+ [ Type (mkTyConApp stablePtrTyCon [arg_ty])
+ , Type ret_ty
+ , mk_stbl_ptr_app
+ , cont
+ ]
{-
The arguments to the external function which will
to be entered using an external calling convention
(stdcall, ccall).
-}
- adj_args = [ mkLit (mkMachInt (fromInt (callConvToInt cconv)))
+ adj_args = [ mkIntLitInt (callConvToInt cconv)
, Var stbl_value
, mkLit (MachLitLit (_PK_ fe_nm) addrPrimTy)
]
-- (probably in the RTS.)
adjustor = SLIT("createAdjustor")
in
- dsCCall adjustor adj_args False False addrTy `thenDs` \ ccall_adj ->
- let ccall_adj_ty = coreExprType ccall_adj
+ dsCCall adjustor adj_args False False ioAddrTy `thenDs` \ ccall_adj ->
+ let ccall_adj_ty = exprType ccall_adj
+ ccall_io_adj = mkLams [stbl_value] $
+ Note (Coerce io_res_ty (unUsgTy ccall_adj_ty))
+ ccall_adj
in
- newSysLocalDs ccall_adj_ty `thenDs` \ x_ccall_adj ->
- let ccall_io_adj =
- mkLams [stbl_value] $
- bindNonRec x_ccall_adj ccall_adj $
- Note (Coerce (mkTyConApp ioTyCon [res_ty]) ccall_adj_ty)
- (Var x_ccall_adj)
- in
- newSysLocalDs (coreExprType ccall_io_adj) `thenDs` \ x_ccall_io_adj ->
let io_app = mkLams tvs $
mkLams [cback] $
- stbl_app x_ccall_io_adj ccall_io_adj addrTy
+ stbl_app ccall_io_adj addrTy
in
- returnDs (NonRec i io_app, fe, h_code, c_code)
+ -- Never inline the f.e.d. function, because the litlit might not be in scope
+ -- in other modules.
+ returnDs (NonRec (i `setInlinePragma` neverInlinePrag) io_app, fe, h_code, c_code)
where
(tvs,sans_foralls) = splitForAllTys ty
- ([arg_ty], io_res) = splitFunTys sans_foralls
+ ([arg_ty], io_res_ty) = splitFunTys sans_foralls
- Just (ioTyCon, [res_ty]) = splitTyConApp_maybe io_res
+ Just (ioTyCon, [res_ty]) = splitTyConApp_maybe io_res_ty
export_ty = mkFunTy (mkTyConApp stablePtrTyCon [arg_ty]) arg_ty
+ ioAddrTy :: Type -- IO Addr
+ ioAddrTy = mkTyConApp ioTyCon [addrTy]
+
toCName :: Id -> String
toCName i = showSDoc (pprCode CStyle (ppr (idName i)))
-
\end{code}
%*
using the hugs/ghc rts invocation API.
\begin{code}
-fexportEntry :: FAST_STRING
+fexportEntry :: String
+ -> FAST_STRING
-> Id
-> [Type]
- -> Maybe Type
+ -> Type
-> CallConv
-> Bool
-> (SDoc, SDoc)
-fexportEntry c_nm helper args res cc isDyn = (header_bits, c_bits)
+fexportEntry mod_nm c_nm helper args res_ty cc isDyn = (header_bits, c_bits)
where
-- name of the (Haskell) helper function generated by the desugarer.
h_nm = ppr helper <> text "_closure"
-- create the application + perform it.
, text "rc=rts_evalIO" <>
parens (foldl appArg (text "(StgClosure*)&" <> h_nm) (zip args c_args) <> comma <> text "&ret") <> semi
- , returnResult
+ , text "rts_checkSchedStatus" <> parens (doubleQuotes (ptext c_nm)
+ <> comma <> text "rc") <> semi
+ , text "return" <> return_what <> semi
, rbrace
]
cParamTypes = map showStgType real_args
- cResType =
- case res of
- Nothing -> text "void"
- Just t -> showStgType t
+ res_ty_is_unit = res_ty == unitTy
+
+ cResType | res_ty_is_unit = text "void"
+ | otherwise = showStgType res_ty
pprCconv
| cc == cCallConv = empty
mkExtern ty nm = text "extern" <+> ty <+> nm <> semi
- returnResult =
- text "rts_checkSchedStatus" <>
- parens (doubleQuotes (ptext c_nm) <> comma <> text "rc") <> semi $$
- (case res of
- Nothing -> text "return"
- Just _ -> text "return" <> parens (res_name)) <> semi
-
- res_name =
- case res of
- Nothing -> empty
- Just t -> unpackHObj t <> parens (text "ret")
+ return_what | res_ty_is_unit = empty
+ | otherwise = parens (unpackHObj res_ty <> parens (text "ret"))
c_args = mkCArgNames 0 args
showFFIType :: Type -> String
showFFIType t = getOccString (getName tc)
where
- tc = case splitTyConApp_maybe t of
+ tc = case splitTyConApp_maybe (repType t) of
Just (tc,_) -> tc
Nothing -> pprPanic "showFFIType" (ppr t)
\end{code}