import DsCCall ( dsCCall, mkFCall, boxResult, unboxArg, resultWrapper )
import DsMonad
-import HsSyn ( ExtName(..), ForeignDecl(..), isDynamicExtName, ForKind(..) )
-import HsDecls ( extNameStatic )
+import HsSyn ( ForeignDecl(..), FoExport(..), FoImport(..) )
import TcHsSyn ( TypecheckedForeignDecl )
import CoreUtils ( exprType, mkInlineMe )
import Id ( Id, idType, idName, mkVanillaGlobal, mkSysLocal,
)
import ForeignCall ( ForeignCall(..), CCallSpec(..),
Safety(..), playSafe,
- CCallTarget(..), dynamicTarget,
+ CExportSpec(..),
CCallConv(..), ccallConvToInt
)
+import CStrings ( CLabelString )
import TysWiredIn ( unitTy, addrTy, stablePtrTyCon )
import TysPrim ( addrPrimTy )
import PrelNames ( hasKey, ioTyConKey, deRefStablePtrName, newStablePtrName,
, SDoc -- C stubs to use when calling
-- "foreign exported" functions.
)
-dsForeigns mod_name fos = foldlDs combine ([], [], empty, empty) fos
+dsForeigns mod_name fos
+ = foldlDs combine ([], [], empty, empty) fos
where
- combine (acc_feb, acc_f, 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` \ bs ->
- returnDs (acc_feb, bs ++ acc_f, acc_h, acc_c)
- | isForeignLabel =
- dsFLabel i (idType i) ext_nm `thenDs` \ b ->
- returnDs (acc_feb, b:acc_f, acc_h, acc_c)
- | isDynamicExtName ext_nm =
- dsFExportDynamic i (idType i) mod_name ext_nm cconv `thenDs` \ (feb,bs,h,c) ->
- returnDs (feb:acc_feb, bs ++ acc_f, h $$ acc_h, c $$ acc_c)
-
- | otherwise = -- foreign export
- dsFExport i (idType i) mod_name ext_nm cconv False `thenDs` \ (feb,fe,h,c) ->
- returnDs (feb:acc_feb, fe:acc_f, h $$ acc_h, c $$ acc_c)
- where
- isForeignImport =
- case imp_exp of
- FoImport _ -> True
- _ -> False
-
- isForeignLabel =
- case imp_exp of
- FoLabel -> True
- _ -> False
-
- FoImport uns = imp_exp
+ combine (acc_feb, acc_f, acc_h, acc_c) (ForeignImport id _ spec _)
+ = dsFImport mod_name id spec `thenDs` \ (bs, h, c) ->
+ returnDs (acc_feb, bs ++ acc_f, h $$ acc_h, c $$ acc_c)
+
+ combine (acc_feb, acc_f, acc_h, acc_c) (ForeignExport id _ (CExport (CExportStatic ext_nm cconv)) _)
+ = dsFExport mod_name id (idType id) ext_nm cconv False `thenDs` \ (feb, b, h, c) ->
+ returnDs (feb:acc_feb, b : acc_f, h $$ acc_h, c $$ acc_c)
\end{code}
+
+%************************************************************************
+%* *
+\subsection{Foreign import}
+%* *
+%************************************************************************
+
Desugaring foreign imports is just the matter of creating a binding
that on its RHS unboxes its arguments, performs the external call
(using the @CCallOp@ primop), before boxing the result up and returning it.
\begin{code}
-dsFImport :: Id
- -> Type -- Type of foreign import.
- -> Safety -- Whether can re-enter the Haskell RTS, do GC etc
- -> ExtName
- -> CCallConv
- -> DsM [Binding]
-dsFImport fn_id ty safety ext_name cconv
+dsFImport :: Module
+ -> Id
+ -> FoImport
+ -> DsM ([Binding], SDoc, SDoc)
+dsFImport mod_name lbl_id (LblImport ext_nm)
+ = ASSERT(fromJust res_ty == addrPrimTy) -- typechecker ensures this
+ returnDs ([(lbl_id, rhs)], empty, empty)
+ where
+ (res_ty, fo_rhs) = resultWrapper (idType lbl_id)
+ rhs = fo_rhs (mkLit (MachLabel ext_nm))
+
+dsFImport mod_name fn_id (CImport spec) = dsFCall mod_name fn_id (CCall spec)
+dsFImport mod_name fn_id (DNImport spec) = dsFCall mod_name fn_id (DNCall spec)
+dsFImport mod_name fn_id (CDynImport cconv) = dsFExportDynamic mod_name fn_id cconv
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{Foreign calls}
+%* *
+%************************************************************************
+
+\begin{code}
+dsFCall mod_Name fn_id fcall
= let
+ ty = idType fn_id
(tvs, fun_ty) = splitForAllTys ty
(arg_tys, io_res_ty) = splitFunTys fun_ty
in
-- These are the ids we pass to boxResult, which are used to decide
-- whether to touch# an argument after the call (used to keep
-- ForeignObj#s live across a 'safe' foreign import).
- maybe_arg_ids | playSafe safety = work_arg_ids
- | otherwise = []
+ maybe_arg_ids | unsafe_call fcall = work_arg_ids
+ | otherwise = []
in
boxResult maybe_arg_ids io_res_ty `thenDs` \ (ccall_result_ty, res_wrapper) ->
getUniqueDs `thenDs` \ ccall_uniq ->
getUniqueDs `thenDs` \ work_uniq ->
let
- lbl = case ext_name of
- Dynamic -> dynamicTarget
- ExtName fs _ -> StaticTarget fs
-
-- Build the worker
worker_ty = mkForAllTys tvs (mkFunTys (map idType work_arg_ids) ccall_result_ty)
- the_ccall = CCall (CCallSpec lbl cconv safety False)
- the_ccall_app = mkFCall ccall_uniq the_ccall val_args ccall_result_ty
+ the_ccall_app = mkFCall ccall_uniq fcall val_args ccall_result_ty
work_rhs = mkLams tvs (mkLams work_arg_ids the_ccall_app)
work_id = mkSysLocal SLIT("$wccall") work_uniq worker_ty
wrapper_body = foldr ($) (res_wrapper work_app) arg_wrappers
wrap_rhs = mkInlineMe (mkLams (tvs ++ args) wrapper_body)
in
- returnDs [(work_id, work_rhs), (fn_id, wrap_rhs)]
+ returnDs ([(work_id, work_rhs), (fn_id, wrap_rhs)], empty, empty)
+
+unsafe_call (CCall (CCallSpec _ _ safety)) = playSafe safety
+unsafe_call (DNCall _) = False
\end{code}
-Foreign labels
-\begin{code}
-dsFLabel :: Id -> Type -> ExtName -> DsM Binding
-dsFLabel nm ty ext_name =
- ASSERT(fromJust res_ty == addrPrimTy) -- typechecker ensures this
- returnDs (nm, fo_rhs (mkLit (MachLabel enm)))
- where
- (res_ty, fo_rhs) = resultWrapper ty
- enm = extNameStatic ext_name
-\end{code}
+%************************************************************************
+%* *
+\subsection{Foreign export}
+%* *
+%************************************************************************
The function that does most of the work for `@foreign export@' declarations.
(see below for the boilerplate code a `@foreign export@' declaration expands
the user-written Haskell function `@M.foo@'.
\begin{code}
-dsFExport :: Id
- -> Type -- Type of foreign export.
- -> Module
- -> ExtName
+dsFExport :: Module
+ -> Id -- Either the exported Id,
+ -- or the foreign-export-dynamic constructor
+ -> Type -- The type of the thing callable from C
+ -> CLabelString -- The name to export to C land
-> CCallConv
- -> Bool -- True => invoke IO action that's hanging off
- -- the first argument's stable pointer
+ -> Bool -- True => foreign export dynamic
+ -- so invoke IO action that's hanging off
+ -- the first argument's stable pointer
-> DsM ( Id -- The foreign-exported Id
, Binding
, SDoc
, SDoc
)
-dsFExport fn_id ty mod_name ext_name cconv isDyn
+dsFExport mod_name fn_id ty 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)
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
+ ext_name f_helper_glob
+ wrapper_arg_tys res_ty cconv isDyn
in
returnDs (f_helper_glob, (f_helper_glob, the_body), h_stub, c_stub)
where
- (tvs,sans_foralls) = splitForAllTys ty
- (fe_arg_tys', orig_res_ty) = splitFunTys sans_foralls
+ (tvs,sans_foralls) = splitForAllTys ty
+ (fe_arg_tys', orig_res_ty) = splitFunTys sans_foralls
- (_, stbl_ptr_ty') = splitForAllTys stbl_ptr_ty
- (_, stbl_ptr_to_ty) = splitAppTy stbl_ptr_ty'
+ (_, 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'
\end{verbatim}
\begin{code}
-dsFExportDynamic :: Id
- -> Type -- Type of foreign export.
- -> Module
- -> ExtName
+dsFExportDynamic :: Module
+ -> Id
-> CCallConv
- -> DsM (Id, [Binding], SDoc, SDoc)
-dsFExportDynamic i ty mod_name ext_name cconv =
- newSysLocalDs ty `thenDs` \ fe_id ->
+ -> DsM ([Binding], SDoc, SDoc)
+dsFExportDynamic mod_name id cconv
+ = newSysLocalDs ty `thenDs` \ fe_id ->
let
-- hack: need to get at the name of the C stub we're about to generate.
- fe_nm = moduleUserString mod_name ++ "_" ++ toCName fe_id
- fe_ext_name = ExtName (_PK_ fe_nm) Nothing
+ fe_nm = _PK_ (moduleUserString mod_name ++ "_" ++ toCName fe_id)
in
- dsFExport i export_ty mod_name fe_ext_name cconv True
- `thenDs` \ (feb, fe, h_code, c_code) ->
- newSysLocalDs arg_ty `thenDs` \ cback ->
- dsLookupGlobalValue newStablePtrName `thenDs` \ newStablePtrId ->
+ dsFExport mod_name id export_ty fe_nm cconv True `thenDs` \ (feb, fe, h_code, c_code) ->
+ newSysLocalDs arg_ty `thenDs` \ cback ->
+ dsLookupGlobalValue newStablePtrName `thenDs` \ newStablePtrId ->
let
mk_stbl_ptr_app = mkApps (Var newStablePtrId) [ Type arg_ty, Var cback ]
in
-}
adj_args = [ mkIntLitInt (ccallConvToInt cconv)
, Var stbl_value
- , mkLit (MachLabel (_PK_ fe_nm))
+ , mkLit (MachLabel fe_nm)
]
-- name of external entry point providing these services.
-- (probably in the RTS.)
io_app = mkLams tvs $
mkLams [cback] $
stbl_app ccall_io_adj res_ty
- fed = (i `setInlinePragma` neverInlinePrag, io_app)
+ fed = (id `setInlinePragma` neverInlinePrag, io_app)
-- Never inline the f.e.d. function, because the litlit
-- might not be in scope in other modules.
in
- returnDs (feb, [fed, fe], h_code, c_code)
+ returnDs ([fed, fe], h_code, c_code)
where
+ ty = idType id
(tvs,sans_foralls) = splitForAllTys ty
([arg_ty], io_res_ty) = splitFunTys sans_foralls
Just (ioTyCon, [res_ty]) = splitTyConApp_maybe io_res_ty
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