\begin{code}
module DsForeign ( dsForeigns ) where
-
#include "HsVersions.h"
+import TcRnMonad -- temp
import CoreSyn
-import DsCCall ( getIoOkDataCon, boxResult, unboxArg,
- can'tSeeDataConsPanic
- )
+import DsCCall ( dsCCall, mkFCall, boxResult, unboxArg, resultWrapper )
import DsMonad
-import DsUtils
-
-import HsSyn ( ExtName(..), ForeignDecl(..), isDynamic )
-import CallConv
-import TcHsSyn ( maybeBoxedPrimType, TypecheckedForeignDecl )
-import CoreUtils ( coreExprType )
-import Id ( Id, dataConArgTys, idType, idName,
- mkVanillaId, dataConRawArgTys,
- dataConTyCon, mkIdVisible
- )
-import IdInfo ( noIdInfo )
-import Literal ( Literal(..), mkMachInt )
-import Maybes ( maybeToBool )
-import Name ( nameString, occNameString, nameOccName, nameUnique )
-import PrelVals ( packStringForCId, eRROR_ID )
-import PrimOp ( PrimOp(..) )
-import Type ( isUnpointedType, splitAlgTyConApp_maybe,
- splitTyConApp_maybe, splitFunTys, splitForAllTys,
- Type, mkFunTys, applyTy, mkForAllTys, mkTyConApp,
- typePrimRep, mkTyVarTy, mkFunTy, splitAppTy
- )
-import PrimRep ( showPrimRepToUser, PrimRep(..) )
-import TyVar ( TyVar )
-import TyCon ( tyConDataCons )
-import TysPrim ( byteArrayPrimTy, realWorldStatePrimTy,
- byteArrayPrimTyCon, mutableByteArrayPrimTyCon,
- realWorldTy, addrPrimTy, mkStablePtrPrimTy,
- intPrimTy
+
+import HsSyn ( ForeignDecl(..), ForeignExport(..), LForeignDecl,
+ ForeignImport(..), CImportSpec(..) )
+import DataCon ( splitProductType_maybe )
+#ifdef DEBUG
+import DataCon ( dataConSourceArity )
+import Type ( isUnLiftedType )
+#endif
+import MachOp ( machRepByteWidth, MachRep(..) )
+import SMRep ( argMachRep, typeCgRep )
+import CoreUtils ( exprType, mkInlineMe )
+import Id ( Id, idType, idName, mkSysLocal, setInlinePragma )
+import Literal ( Literal(..), mkStringLit )
+import Module ( moduleFS )
+import Name ( getOccString, NamedThing(..) )
+import Type ( repType, coreEqType )
+import TcType ( Type, mkFunTys, mkForAllTys, mkTyConApp,
+ mkFunTy, tcSplitTyConApp_maybe,
+ tcSplitForAllTys, tcSplitFunTys, tcTyConAppArgs,
)
-import TysWiredIn ( getStatePairingConInfo,
- unitDataCon, stringTy,
- realWorldStateTy, stateDataCon,
- isFFIArgumentTy, unitTy,
- addrTy, stablePtrTyCon,
- stateAndPtrPrimDataCon
+
+import BasicTypes ( Boxity(..) )
+import HscTypes ( ForeignStubs(..) )
+import ForeignCall ( ForeignCall(..), CCallSpec(..),
+ Safety(..), playSafe,
+ CExportSpec(..), CLabelString,
+ CCallConv(..), ccallConvToInt,
+ ccallConvAttribute
)
+import TysWiredIn ( unitTy, tupleTyCon )
+import TysPrim ( addrPrimTy, mkStablePtrPrimTy, alphaTy )
+import PrelNames ( hasKey, ioTyConKey, stablePtrTyConName, newStablePtrName, bindIOName,
+ checkDotnetResName )
+import BasicTypes ( Activation( NeverActive ) )
+import SrcLoc ( Located(..), unLoc )
import Outputable
+import Maybe ( fromJust, isNothing )
+import FastString
\end{code}
Desugaring of @foreign@ declarations is naturally split up into
parts, an @import@ and an @export@ part. A @foreign import@
-declaration
-
+declaration
+\begin{verbatim}
foreign import cc nm f :: prim_args -> IO prim_res
-
+\end{verbatim}
is the same as
-
+\begin{verbatim}
f :: prim_args -> IO prim_res
f a1 ... an = _ccall_ nm cc a1 ... an
-
+\end{verbatim}
so we reuse the desugaring code in @DsCCall@ to deal with these.
\begin{code}
-dsForeigns :: [TypecheckedForeignDecl]
- -> DsM ( [CoreBinding] -- desugared foreign imports
- , [CoreBinding] -- helper functions for foreign exports
- , SDoc -- auxilliary code to emit into .hc file
- , SDoc -- Header file prototypes for "foreign exported" functions.
- , SDoc -- C stubs to use when calling "foreign exported" funs.
- )
-dsForeigns fos = foldlDs combine ([],[],empty,empty,empty) fos
+type Binding = (Id, CoreExpr) -- No rec/nonrec structure;
+ -- the occurrence analyser will sort it all out
+
+dsForeigns :: [LForeignDecl Id]
+ -> DsM (ForeignStubs, [Binding])
+dsForeigns []
+ = returnDs (NoStubs, [])
+dsForeigns fos
+ = foldlDs combine (ForeignStubs empty empty [] [], []) fos
where
- combine (acc_fi, acc_fe, acc_hc, acc_h, acc_c) fo@(ForeignDecl i imp_exp _ ext_nm cconv _)
- | isForeignImport =
- dsFImport i (idType i) uns ext_nm cconv `thenDs` \ b ->
- returnDs (b:acc_fi, acc_fe, acc_hc, acc_h, acc_c)
- | isDynamic ext_nm =
- dsFExportDynamic i (idType i) ext_nm cconv `thenDs` \ (fi,fe,hc,h,c) ->
- returnDs (fi:acc_fi, fe:acc_fe, hc $$ acc_hc, h $$ acc_h, c $$ acc_c)
- | otherwise =
- dsFExport i (idType i) ext_nm cconv False `thenDs` \ (fe,hc,h,c) ->
- returnDs (acc_fi, fe:acc_fe, hc $$ acc_hc, h $$ acc_h, c $$ acc_c)
-
- where
- isForeignImport = maybeToBool imp_exp
- (Just uns) = imp_exp
-
+ combine stubs (L loc decl) = putSrcSpanDs loc (combine1 stubs decl)
+
+ combine1 (ForeignStubs acc_h acc_c acc_hdrs acc_feb, acc_f)
+ (ForeignImport id _ spec depr)
+ = traceIf (text "fi start" <+> ppr id) `thenDs` \ _ ->
+ dsFImport (unLoc id) spec `thenDs` \ (bs, h, c, mbhd) ->
+ warnDepr depr `thenDs` \ _ ->
+ traceIf (text "fi end" <+> ppr id) `thenDs` \ _ ->
+ returnDs (ForeignStubs (h $$ acc_h)
+ (c $$ acc_c)
+ (addH mbhd acc_hdrs)
+ acc_feb,
+ bs ++ acc_f)
+
+ combine1 (ForeignStubs acc_h acc_c acc_hdrs acc_feb, acc_f)
+ (ForeignExport (L _ id) _ (CExport (CExportStatic ext_nm cconv)) depr)
+ = dsFExport id (idType id)
+ ext_nm cconv False `thenDs` \(h, c, _, _) ->
+ warnDepr depr `thenDs` \_ ->
+ returnDs (ForeignStubs (h $$ acc_h) (c $$ acc_c) acc_hdrs (id:acc_feb),
+ acc_f)
+
+ addH Nothing ls = ls
+ addH (Just e) ls
+ | e `elem` ls = ls
+ | otherwise = e:ls
+
+ warnDepr False = returnDs ()
+ warnDepr True = dsWarn msg
+ where
+ msg = ptext SLIT("foreign declaration uses deprecated non-standard syntax")
\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.
+(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 CoreBinding
-dsFImport nm ty may_not_gc ext_name cconv =
- newSysLocalDs realWorldStatePrimTy `thenDs` \ old_s ->
- mkArgs ty `thenDs` \ (tvs, args, io_res_ty) ->
- mapAndUnzipDs unboxArg args `thenDs` \ (unboxed_args, arg_wrappers) ->
- let
- final_args = Var old_s : unboxed_args
- (ioOkDataCon, ioDataCon, result_ty) = getIoOkDataCon io_res_ty
- in
- boxResult ioOkDataCon result_ty `thenDs` \ (final_result_ty, res_wrapper) ->
- let
- label =
- case ext_name of
- Dynamic -> Nothing
- ExtName fs _ -> Just fs
-
- the_ccall_op = CCallOp label False (not may_not_gc) cconv
- (map coreExprType final_args)
- final_result_ty
- in
- mkPrimDs the_ccall_op (map VarArg final_args) `thenDs` \ the_prim_app ->
- let
- the_body = mkValLam [old_s]
- (foldr ($) (res_wrapper the_prim_app) arg_wrappers)
- in
- newSysLocalDs (coreExprType the_body) `thenDs` \ ds ->
- let
- io_app = mkValApp (mkTyApp (Var ioDataCon) [result_ty]) [VarArg ds]
- fo_rhs = mkTyLam tvs $
- mkValLam (map (\ (Var x) -> x) args)
- (mkCoLetAny (NonRec ds the_body) io_app)
- in
- returnDs (NonRec nm fo_rhs)
-
-mkArgs :: Type -> DsM ([TyVar], [CoreExpr], Type)
-mkArgs ty =
- case splitFunTys sans_foralls of
- (arg_tys, res_ty) ->
- newSysLocalsDs arg_tys `thenDs` \ ds_args ->
- returnDs (tvs, map Var ds_args, res_ty)
+ -> ForeignImport
+ -> DsM ([Binding], SDoc, SDoc, Maybe FastString)
+dsFImport id (CImport cconv safety header lib spec)
+ = dsCImport id spec cconv safety no_hdrs `thenDs` \(ids, h, c) ->
+ returnDs (ids, h, c, if no_hdrs then Nothing else Just header)
where
- (tvs, sans_foralls) = splitForAllTys ty
-
+ no_hdrs = nullFS header
+
+ -- FIXME: the `lib' field is needed for .NET ILX generation when invoking
+ -- routines that are external to the .NET runtime, but GHC doesn't
+ -- support such calls yet; if `nullFastString lib', the value was not given
+dsFImport id (DNImport spec)
+ = dsFCall id (DNCall spec) True {- No headers -} `thenDs` \(ids, h, c) ->
+ returnDs (ids, h, c, Nothing)
+
+dsCImport :: Id
+ -> CImportSpec
+ -> CCallConv
+ -> Safety
+ -> Bool -- True <=> no headers in the f.i decl
+ -> DsM ([Binding], SDoc, SDoc)
+dsCImport id (CLabel cid) _ _ no_hdrs
+ = resultWrapper (idType id) `thenDs` \ (resTy, foRhs) ->
+ ASSERT(fromJust resTy `coreEqType` addrPrimTy) -- typechecker ensures this
+ let rhs = foRhs (mkLit (MachLabel cid Nothing)) in
+ returnDs ([(setImpInline no_hdrs id, rhs)], empty, empty)
+dsCImport id (CFunction target) cconv safety no_hdrs
+ = dsFCall id (CCall (CCallSpec target cconv safety)) no_hdrs
+dsCImport id CWrapper cconv _ _
+ = dsFExportDynamic id cconv
+
+setImpInline :: Bool -- True <=> No #include headers
+ -- in the foreign import declaration
+ -> Id -> Id
+-- If there is a #include header in the foreign import
+-- we make the worker non-inlinable, because we currently
+-- don't keep the #include stuff in the CCallId, and hence
+-- it won't be visible in the importing module, which can be
+-- fatal.
+-- (The #include stuff is just collected from the foreign import
+-- decls in a module.)
+-- If you want to do cross-module inlining of the c-calls themselves,
+-- put the #include stuff in the package spec, not the foreign
+-- import decl.
+setImpInline True id = id
+setImpInline False id = id `setInlinePragma` NeverActive
\end{code}
+
+%************************************************************************
+%* *
+\subsection{Foreign calls}
+%* *
+%************************************************************************
+
\begin{code}
-dsFExport :: Id
- -> Type -- Type of foreign export.
- -> ExtName
- -> CallConv
- -> Bool -- True => invoke IO action that's hanging off
- -- the first argument's stable pointer
- -> DsM (CoreBinding, SDoc, SDoc, SDoc)
-dsFExport i ty ext_name cconv isDyn =
- newSysLocalDs realWorldStatePrimTy `thenDs` \ s1 ->
- newSysLocalDs realWorldStatePrimTy `thenDs` \ s3 ->
- newSysLocalDs helper_ty `thenDs` \ f_helper ->
- newSysLocalsDs helper_arg_tys `thenDs` \ helper_args ->
- newSysLocalDs res_ty `thenDs` \ v1 ->
- unboxResult the_prim_result_ty res_ty s3 v1 `thenDs` \ (state_and_prim_ty, unpack_result) ->
- zipWithDs boxArg fe_arg_tys helper_args `thenDs` \ stuff ->
- (if isDyn then
- newSysLocalDs realWorldStatePrimTy `thenDs` \ s11 ->
- newSysLocalDs stbl_ptr_ty `thenDs` \ stbl_ptr ->
- newSysLocalDs stbl_ptr_to_ty `thenDs` \ f ->
- mkPrimDs DeRefStablePtrOp
- [TyArg stbl_ptr_to_ty,
- VarArg (Var stbl_ptr),
- VarArg (Var s1)] `thenDs` \ the_deref_app ->
- let
- stbl_app = \ cont ->
- Case the_deref_app
- (AlgAlts [(stateAndPtrPrimDataCon, [s11, f], cont)]
- NoDefault)
- in
- returnDs (f, stbl_app, s11, stbl_ptr)
- else
- returnDs (i,
- \ body -> body,
- s1,
- panic "stbl_ptr" -- should never be touched.
- )) `thenDs` \ (i, getFun_wrapper, s2, stbl_ptr) ->
- let
- (boxed_args, arg_wrappers) = unzip stuff
+dsFCall fn_id fcall no_hdrs
+ = let
+ ty = idType fn_id
+ (tvs, fun_ty) = tcSplitForAllTys ty
+ (arg_tys, io_res_ty) = tcSplitFunTys fun_ty
+ -- Must use tcSplit* functions because we want to
+ -- see that (IO t) in the corner
+ in
+ newSysLocalsDs arg_tys `thenDs` \ args ->
+ mapAndUnzipDs unboxArg (map Var args) `thenDs` \ (val_args, arg_wrappers) ->
- wrapper_args
- | isDyn = stbl_ptr:helper_args
- | otherwise = helper_args
+ let
+ work_arg_ids = [v | Var v <- val_args] -- All guaranteed to be vars
+
+ forDotnet =
+ case fcall of
+ DNCall{} -> True
+ _ -> False
+
+ topConDs
+ | forDotnet =
+ dsLookupGlobalId checkDotnetResName `thenDs` \ check_id ->
+ return (Just check_id)
+ | otherwise = return Nothing
+
+ augmentResultDs
+ | forDotnet =
+ newSysLocalDs addrPrimTy `thenDs` \ err_res ->
+ returnDs (\ (mb_res_ty, resWrap) ->
+ case mb_res_ty of
+ Nothing -> (Just (mkTyConApp (tupleTyCon Unboxed 1)
+ [ addrPrimTy ]),
+ resWrap)
+ Just x -> (Just (mkTyConApp (tupleTyCon Unboxed 2)
+ [ x, addrPrimTy ]),
+ resWrap))
+ | otherwise = returnDs id
+ in
+ augmentResultDs `thenDs` \ augment ->
+ topConDs `thenDs` \ topCon ->
+ boxResult augment topCon io_res_ty `thenDs` \ (ccall_result_ty, res_wrapper) ->
- wrapper_arg_tys
- | isDyn = stbl_ptr_ty:helper_arg_tys
- | otherwise = helper_arg_tys
+ newUnique `thenDs` \ ccall_uniq ->
+ newUnique `thenDs` \ work_uniq ->
+ let
+ -- Build the worker
+ worker_ty = mkForAllTys tvs (mkFunTys (map idType work_arg_ids) 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 = setImpInline no_hdrs $ -- See comments with setImpInline
+ mkSysLocal FSLIT("$wccall") work_uniq worker_ty
+
+ -- Build the wrapper
+ work_app = mkApps (mkVarApps (Var work_id) tvs) val_args
+ wrapper_body = foldr ($) (res_wrapper work_app) arg_wrappers
+ wrap_rhs = mkInlineMe (mkLams (tvs ++ args) wrapper_body)
+ in
+ returnDs ([(work_id, work_rhs), (fn_id, wrap_rhs)], empty, empty)
- fe_app = mkGenApp (Var i) (map (TyArg . mkTyVarTy) tvs ++ map VarArg boxed_args)
- the_app =
- getFun_wrapper $
- mkValApp (Note (Coerce io_result_ty io_res) fe_app)
- [VarArg s2]
- in
- newFailLocalDs (coreExprType the_app) `thenDs` \ wild ->
- getModuleAndGroupDs `thenDs` \ (mod,_) ->
- getUniqueDs `thenDs` \ uniq ->
- let
+unsafe_call (CCall (CCallSpec _ _ safety)) = playSafe safety
+unsafe_call (DNCall _) = False
+\end{code}
- the_body =
- mkTyLam tvs $
- mkValLam wrapper_args $
- mkValLam [s1] $
- foldr ($) (perform_and_unpack) arg_wrappers
- perform_and_unpack =
- Case the_app (AlgAlts [(ioOkDataCon, [s3, v1], unpack_result)]
- (BindDefault wild err))
+%************************************************************************
+%* *
+\subsection{Foreign export}
+%* *
+%************************************************************************
- c_nm =
- case ext_name of
- ExtName fs _ -> fs
+The function that does most of the work for `@foreign export@' declarations.
+(see below for the boilerplate code a `@foreign export@' declaration expands
+ into.)
- full_msg = "Exception caught: " ++ _UNPK_ (nameString (idName i))
- msg = NoRepStr (_PK_ full_msg)
- err = mkApp (Var eRROR_ID) [state_and_prim_ty] [LitArg msg]
+For each `@foreign export foo@' in a module M we generate:
+\begin{itemize}
+\item a C function `@foo@', which calls
+\item a Haskell stub `@M.$ffoo@', which calls
+\end{itemize}
+the user-written Haskell function `@M.foo@'.
- f_helper_glob = (mkIdVisible mod uniq f_helper)
- (hc_stub, h_stub, c_stub) = fexportEntry c_nm f_helper_glob wrapper_arg_tys the_prim_result_ty cconv
+\begin{code}
+dsFExport :: 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 => foreign export dynamic
+ -- so invoke IO action that's hanging off
+ -- the first argument's stable pointer
+ -> DsM ( SDoc -- contents of Module_stub.h
+ , SDoc -- contents of Module_stub.c
+ , [MachRep] -- primitive arguments expected by stub function
+ , Int -- size of args to stub function
+ )
+
+dsFExport fn_id ty ext_name cconv isDyn
+ =
+ let
+ (_tvs,sans_foralls) = tcSplitForAllTys ty
+ (fe_arg_tys', orig_res_ty) = tcSplitFunTys sans_foralls
+ -- We must use tcSplits here, because we want to see
+ -- the (IO t) in the corner of the type!
+ fe_arg_tys | isDyn = tail fe_arg_tys'
+ | otherwise = fe_arg_tys'
in
- returnDs (NonRec f_helper_glob the_body, hc_stub, h_stub, c_stub)
- where
- (tvs,sans_foralls) = splitForAllTys ty
- (fe_arg_tys', io_res) = splitFunTys sans_foralls
- (ioOkDataCon, ioDataCon, res_ty) = getIoOkDataCon io_res
-
- maybe_data_type = splitAlgTyConApp_maybe res_ty
- Just (tycon, tycon_arg_tys, data_cons) = maybe_data_type
- (the_data_con : other_data_cons) = data_cons
-
- data_con_arg_tys = dataConArgTys the_data_con tycon_arg_tys
- (prim_result_ty : other_args_tys) = data_con_arg_tys
-
- ioDataConTy = idType ioDataCon
- (io_tvs, ioDataConTy') = splitForAllTys ioDataConTy
- ([arg_ty], _) = splitFunTys ioDataConTy'
- io_result_ty = applyTy (mkForAllTys io_tvs arg_ty) res_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'
-
- (stbl_ptr_ty, helper_arg_tys) =
- case (map unboxTy fe_arg_tys') of
- (x:xs) | isDyn -> (x,xs)
- ls -> (error "stbl_ptr_ty", ls)
-
- helper_ty =
- mkForAllTys tvs $
- mkFunTys (arg_tys ++ [realWorldStatePrimTy])
- state_and_prim_ty
- where
- arg_tys
- | isDyn = stbl_ptr_ty : helper_arg_tys
- | otherwise = helper_arg_tys
-
- the_prim_result_ty
- | null data_con_arg_tys = Nothing
- | otherwise = Just prim_result_ty
-
- state_and_prim_ty
- | (null other_data_cons) &&
- (null data_con_arg_tys) = realWorldStateTy
- | otherwise = snd (getStatePairingConInfo (unboxTy res_ty))
+ -- Look at the result type of the exported function, orig_res_ty
+ -- If it's IO t, return (t, True)
+ -- If it's plain t, return (t, False)
+ (case tcSplitTyConApp_maybe orig_res_ty of
+ -- We must use tcSplit here so that we see the (IO t) in
+ -- the type. [IO t is transparent to plain splitTyConApp.]
+
+ Just (ioTyCon, [res_ty])
+ -> ASSERT( ioTyCon `hasKey` ioTyConKey )
+ -- The function already returns IO t
+ returnDs (res_ty, True)
+
+ other -> -- The function returns t
+ returnDs (orig_res_ty, False)
+ )
+ `thenDs` \ (res_ty, -- t
+ is_IO_res_ty) -> -- Bool
+ returnDs $
+ mkFExportCBits ext_name
+ (if isDyn then Nothing else Just fn_id)
+ fe_arg_tys res_ty is_IO_res_ty cconv
\end{code}
-"foreign export dynamic" lets you dress up Haskell IO actions
+@foreign export dynamic@ lets you dress up Haskell IO actions
of some fixed type behind an externally callable interface (i.e.,
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 (newStablePtr 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
\begin{code}
dsFExportDynamic :: Id
- -> Type -- Type of foreign export.
- -> ExtName
- -> CallConv
- -> DsM (CoreBinding, CoreBinding, SDoc, SDoc, SDoc)
-dsFExportDynamic i ty ext_name cconv =
- newSysLocalDs ty `thenDs` \ fe_id ->
+ -> CCallConv
+ -> DsM ([Binding], SDoc, SDoc)
+dsFExportDynamic id cconv
+ = newSysLocalDs ty `thenDs` \ fe_id ->
+ getModuleDs `thenDs` \ mod_name ->
let
-- hack: need to get at the name of the C stub we're about to generate.
- fe_nm = toCName fe_id
- fe_ext_name = ExtName (_PK_ fe_nm) Nothing
+ fe_nm = mkFastString (unpackFS (zEncodeFS (moduleFS mod_name)) ++ "_" ++ toCName fe_id)
in
- dsFExport i export_ty fe_ext_name cconv True `thenDs` \ (fe@(NonRec fe_helper fe_expr), hc_code, h_code, c_code) ->
- newSysLocalDs realWorldStatePrimTy `thenDs` \ s1 ->
- newSysLocalDs realWorldStatePrimTy `thenDs` \ s2 ->
- newSysLocalDs realWorldStatePrimTy `thenDs` \ s3 ->
- newSysLocalDs arg_ty `thenDs` \ cback_arg ->
- newSysLocalDs arg_ty `thenDs` \ cback ->
- newSysLocalDs (mkStablePtrPrimTy arg_ty) `thenDs` \ stbl ->
- newSysLocalDs addrPrimTy `thenDs` \ addrPrim ->
- newSysLocalDs addrTy `thenDs` \ addr ->
- mkPrimDs MakeStablePtrOp [TyArg arg_ty,
- VarArg (Var cback),
- VarArg (Var s1)] `thenDs` \ mkStablePtr_app ->
- mkPrimDs Addr2IntOp [VarArg (Var addrPrim)] `thenDs` \ the_addr2Int_app ->
- boxArg addrTy addrPrim `thenDs` \ (addr_result, addrPrim_wrapper) ->
+ newSysLocalDs arg_ty `thenDs` \ cback ->
+ dsLookupGlobalId newStablePtrName `thenDs` \ newStablePtrId ->
+ dsLookupTyCon stablePtrTyConName `thenDs` \ stable_ptr_tycon ->
let
- (stateAndStablePtrPrimDataCon, _) = getStatePairingConInfo (mkStablePtrPrimTy arg_ty)
- (stateAndAddrPrimDataCon, stateAndAddrPrimTy) = getStatePairingConInfo addrPrimTy
-
- cc
- | cconv == stdCallConv = 1
- | otherwise = 0
-
- ccall_args = [Var s2, Lit (mkMachInt cc),
- Var stbl,
- Lit (MachLitLit (_PK_ fe_nm) AddrRep)]
-
- label = Just SLIT("createAdjustor")
- the_ccall_op = CCallOp label False False{-won't GC-} cCallConv
- (map coreExprType ccall_args)
- stateAndAddrPrimTy
+ mk_stbl_ptr_app = mkApps (Var newStablePtrId) [ Type arg_ty, Var cback ]
+ stable_ptr_ty = mkTyConApp stable_ptr_tycon [arg_ty]
+ export_ty = mkFunTy stable_ptr_ty arg_ty
in
- mkPrimDs the_ccall_op (map VarArg ccall_args) `thenDs` \ the_ccall_app ->
- mkConDs ioOkDataCon
- [TyArg res_ty, VarArg (Var s3), VarArg (Var addr_result)]
- `thenDs` \ ioOkApp ->
- newSysLocalDs intPrimTy `thenDs` \ default_val ->
+ dsLookupGlobalId bindIOName `thenDs` \ bindIOId ->
+ newSysLocalDs stable_ptr_ty `thenDs` \ stbl_value ->
+ dsFExport id export_ty fe_nm cconv True
+ `thenDs` \ (h_code, c_code, arg_reps, args_size) ->
let
- the_mkStablePtr = \ cont ->
- Case mkStablePtr_app
- (AlgAlts [(stateAndStablePtrPrimDataCon, [s2, stbl], cont)]
- NoDefault)
-
- the_ccall = \ cont ->
- Case the_ccall_app
- (AlgAlts [(stateAndAddrPrimDataCon, [s3, addrPrim], cont)]
- NoDefault)
- the_addr2Int = \ cont ->
- Case the_addr2Int_app
- (PrimAlts [(mkMachInt 0, io_fail)]
- (BindDefault default_val cont))
-
- io_fail = mkApp (Var eRROR_ID) [coreExprType wrap_res] [LitArg msg]
- full_msg = "Exception caught: " ++ _UNPK_ (nameString (idName i))
- msg = NoRepStr (_PK_ full_msg)
-
- wrap_res = addrPrim_wrapper ioOkApp
- the_body =
- mkTyLam tvs $
- mkValLam [cback,s1] $
- the_mkStablePtr $
- the_ccall $
- the_addr2Int wrap_res
-
- in
- newSysLocalDs (coreExprType the_body) `thenDs` \ ds ->
- newSysLocalDs (mkFunTy realWorldStatePrimTy
- (coreExprType ioOkApp)) `thenDs` \ ap ->
- let
- io_app = mkValApp (mkTyApp (Var ioDataCon) [res_ty]) [VarArg ap]
- io_action =
- mkTyLam tvs $
- mkValLam [cback_arg] $
- mkCoLetAny (NonRec ds the_body) $
- mkCoLetAny (NonRec ap (mkValApp (mkTyApp (Var ds) (map mkTyVarTy tvs)) [VarArg cback_arg])) $
- io_app
- in
- returnDs (NonRec i io_action, fe, hc_code, h_code, c_code)
- where
- (tvs,sans_foralls) = splitForAllTys ty
- ([arg_ty], io_res) = splitFunTys sans_foralls
- (ioOkDataCon, ioDataCon, res_ty) = getIoOkDataCon io_res
+ stbl_app cont ret_ty = mkApps (Var bindIOId)
+ [ Type stable_ptr_ty
+ , Type ret_ty
+ , mk_stbl_ptr_app
+ , cont
+ ]
+ {-
+ The arguments to the external function which will
+ create a little bit of (template) code on the fly
+ for allowing the (stable pointed) Haskell closure
+ to be entered using an external calling convention
+ (stdcall, ccall).
+ -}
+ adj_args = [ mkIntLitInt (ccallConvToInt cconv)
+ , Var stbl_value
+ , mkLit (MachLabel fe_nm mb_sz_args)
+ , mkLit (mkStringLit arg_type_info)
+ ]
+ -- name of external entry point providing these services.
+ -- (probably in the RTS.)
+ adjustor = FSLIT("createAdjustor")
+
+ arg_type_info = map repCharCode arg_reps
+ repCharCode F32 = 'f'
+ repCharCode F64 = 'd'
+ repCharCode I64 = 'l'
+ repCharCode _ = 'i'
+
+ -- Determine the number of bytes of arguments to the stub function,
+ -- so that we can attach the '@N' suffix to its label if it is a
+ -- stdcall on Windows.
+ mb_sz_args = case cconv of
+ StdCallConv -> Just args_size
+ _ -> Nothing
- ioDataConTy = idType ioDataCon
- (io_tvs, ioDataConTy') = splitForAllTys ioDataConTy
--- ([arg_ty], _) = splitFunTys ioDataConTy'
- io_result_ty = applyTy (mkForAllTys io_tvs arg_ty) res_ty
+ in
+ dsCCall adjustor adj_args PlayRisky io_res_ty `thenDs` \ ccall_adj ->
+ -- PlayRisky: the adjustor doesn't allocate in the Haskell heap or do a callback
+ let ccall_adj_ty = exprType ccall_adj
+ ccall_io_adj = mkLams [stbl_value] $
+ Note (Coerce io_res_ty ccall_adj_ty)
+ ccall_adj
+ io_app = mkLams tvs $
+ mkLams [cback] $
+ stbl_app ccall_io_adj res_ty
+ fed = (id `setInlinePragma` NeverActive, io_app)
+ -- Never inline the f.e.d. function, because the litlit
+ -- might not be in scope in other modules.
+ in
+ returnDs ([fed], h_code, c_code)
- export_ty = mkFunTy (mkTyConApp stablePtrTyCon [arg_ty]) arg_ty
+ where
+ ty = idType id
+ (tvs,sans_foralls) = tcSplitForAllTys ty
+ ([arg_ty], io_res_ty) = tcSplitFunTys sans_foralls
+ [res_ty] = tcTyConAppArgs io_res_ty
+ -- Must use tcSplit* to see the (IO t), which is a newtype
toCName :: Id -> String
toCName i = showSDoc (pprCode CStyle (ppr (idName i)))
-
-\end{code}
-
-%*
-%
-\subsection{Helper functions}
-%
-%*
-
-@boxArg@ boxes up an argument in preparation for calling
-a function that maybe expects a boxed version of it, i.e.,
-
-\begin{verbatim}
-boxArg Addr a# ==> let ds_foo :: Addr ; ds_foo = A# a# in f ...ds_foo..
-\end{verbatim}
-
-\begin{code}
-boxArg :: Type -- Expected type after possible boxing of arg.
- -> Id -- The (unboxed) argument
- -> DsM (Id, -- To pass as the actual, boxed argument
- CoreExpr -> CoreExpr -- Wrapper to box the arg
- )
-boxArg box_ty prim_arg
- | isUnpointedType box_ty = returnDs (prim_arg, \body -> body)
- -- Data types with a single constructor,
- -- which has a single, primitive-typed arg
- | otherwise
- = newSysLocalDs box_ty `thenDs` \ box_arg ->
- returnDs ( box_arg
- , Let (NonRec box_arg (mkCon box_data_con tys_applied [VarArg prim_arg]))
- )
- where
- maybe_boxed_prim_arg_ty = maybeBoxedPrimType box_ty
- (Just (_,tys_applied,_)) = splitAlgTyConApp_maybe box_ty
- (Just (box_data_con, _)) = maybe_boxed_prim_arg_ty
-\end{code}
-
-@foreign export@ed functions may return a value back to the outside world.
-@unboxResult@ takes care of converting from the (boxed) value that the
-exported action returns to the (unboxed) value that is returned across
-the border.
-
-\begin{code}
-unboxResult :: Maybe Type -- the (unboxed) type we want to return (along with the state token)
- -- Nothing => no result, just the state token.
- -> Type -- the (boxed) type we have in our hand.
- -> Id -- the state token
- -> Id -- boxed arg
- -> DsM (Type, -- type of returned expression.
- CoreExpr) -- expr that unboxes result and returns state+unboxed result.
-
-unboxResult mb_res_uboxed_ty res_ty new_s v_boxed
- | not (maybeToBool mb_res_uboxed_ty)
- = -- no result, just return state token
- mkConDs stateDataCon [ TyArg realWorldTy
- , VarArg (Var new_s)] `thenDs` \ the_st ->
- returnDs (realWorldStateTy, the_st)
-
- | null data_cons
- -- oops! can't see the data constructors
- = can'tSeeDataConsPanic "result" res_ty
-
- | (maybeToBool maybe_data_type) && -- Data type
- (null other_data_cons) && -- - with one constructor,
- isUnpointedType res_uboxed_ty -- - and of primitive type.
- -- (Glasgow extension)
- =
- newSysLocalDs res_uboxed_ty `thenDs` \ v_unboxed ->
- mkConDs state_and_prim_datacon
- ((TyArg realWorldTy):map (TyArg ) tycon_arg_tys ++
- [ VarArg (Var new_s)
- , VarArg (Var v_unboxed)]) `thenDs` \ the_result ->
- let
- the_alt = (the_data_con, [v_unboxed], the_result)
- in
- returnDs (state_and_prim_ty,
- Case (Var v_boxed) (AlgAlts [the_alt] NoDefault))
-
- | otherwise
- = pprPanic "unboxResult: " (ppr res_ty)
- where
- (Just res_uboxed_ty) = mb_res_uboxed_ty
-
- maybe_data_type = splitAlgTyConApp_maybe res_ty
- Just (tycon, tycon_arg_tys, data_cons) = maybe_data_type
- (the_data_con : other_data_cons) = data_cons
-
- (state_and_prim_datacon, state_and_prim_ty) = getStatePairingConInfo res_uboxed_ty
-
-\end{code}
-
-Returned the unboxed type of a (primitive) type:
-
-\begin{code}
-unboxTy :: Type -> Type
-unboxTy ty
- | isUnpointedType ty || (ty == unitTy) = ty
- | otherwise =
- ASSERT( isFFIArgumentTy ty ) -- legal arg types subsume result types.
- case splitTyConApp_maybe ty of
- Just (tyc,ts) ->
- case (tyConDataCons tyc) of
- [dc] -> case (dataConArgTys dc ts) of
- [ubox] -> ubox
- -- HACK: for the array types, the prim type is
- -- the second tycon arg.
- [_,ubox] -> ubox
- _ -> pprPanic "unboxTy: " (ppr ty)
- _ -> pprPanic "unboxTy: " (ppr ty)
- _ -> pprPanic "unboxTy: " (ppr ty)
-
\end{code}
%*
%
%*
-[Severe hack to get @foreign export@ off the ground:]
-
-For each @foreign export@ function, a C stub together with a @.hc@ stub
-is generated. The C stub enters the .hc stub, setting up the passing of
-parameters from C land to STG land through the use of global variables
-(don't worry, this just a temporary solution!). Ditto for the result.
-
-[
-The generation of .hc code will go once the transition is
-made over to the new rts. Hence the hack, instead of extending
-AbsCSyn to cope with the .hc code generated.
-]
+For each @foreign export@ function, a C stub function is generated.
+The C stub constructs the application of the exported Haskell function
+using the hugs/ghc rts invocation API.
\begin{code}
-fexportEntry :: FAST_STRING -> Id -> [Type] -> Maybe Type -> CallConv -> (SDoc, SDoc, SDoc)
-fexportEntry c_nm helper args res cc =
- ( paramArea $$ stopTemplate $$ startTemplate $$ vtblTemplate, h_code, c_code )
+mkFExportCBits :: FastString
+ -> Maybe Id -- Just==static, Nothing==dynamic
+ -> [Type]
+ -> Type
+ -> Bool -- True <=> returns an IO type
+ -> CCallConv
+ -> (SDoc,
+ SDoc,
+ [MachRep], -- the argument reps
+ Int -- total size of arguments
+ )
+mkFExportCBits c_nm maybe_target arg_htys res_hty is_IO_res_ty cc
+ = (header_bits, c_bits,
+ [rep | (_,_,_,rep) <- arg_info], -- just the real args
+ sum [ machRepByteWidth rep | (_,_,_,rep) <- aug_arg_info] -- all the args
+ )
where
- (h_code, c_code) = mkCStub c_nm h_stub_nm args res cc
+ -- list the arguments to the C function
+ arg_info :: [(SDoc, -- arg name
+ SDoc, -- C type
+ Type, -- Haskell type
+ MachRep)] -- the MachRep
+ arg_info = [ (text ('a':show n), showStgType ty, ty,
+ typeMachRep (getPrimTyOf ty))
+ | (ty,n) <- zip arg_htys [1..] ]
+
+ -- add some auxiliary args; the stable ptr in the wrapper case, and
+ -- a slot for the dummy return address in the wrapper + ccall case
+ aug_arg_info
+ | isNothing maybe_target = stable_ptr_arg : insertRetAddr cc arg_info
+ | otherwise = arg_info
+
+ stable_ptr_arg =
+ (text "the_stableptr", text "StgStablePtr", undefined,
+ typeMachRep (mkStablePtrPrimTy alphaTy))
+
+ -- stuff to do with the return type of the C function
+ res_hty_is_unit = res_hty `coreEqType` unitTy -- Look through any newtypes
+
+ cResType | res_hty_is_unit = text "void"
+ | otherwise = showStgType res_hty
+
+ -- Now we can cook up the prototype for the exported function.
+ pprCconv = case cc of
+ CCallConv -> empty
+ StdCallConv -> text (ccallConvAttribute cc)
+
+ header_bits = ptext SLIT("extern") <+> fun_proto <> semi
+
+ fun_proto = cResType <+> pprCconv <+> ftext c_nm <>
+ parens (hsep (punctuate comma (map (\(nm,ty,_,_) -> ty <+> nm)
+ aug_arg_info)))
+
+ -- the target which will form the root of what we ask rts_evalIO to run
+ the_cfun
+ = case maybe_target of
+ Nothing -> text "(StgClosure*)deRefStablePtr(the_stableptr)"
+ Just hs_fn -> char '&' <> ppr hs_fn <> text "_closure"
+
+ cap = text "cap" <> comma
+
+ -- the expression we give to rts_evalIO
+ expr_to_run
+ = foldl appArg the_cfun arg_info -- NOT aug_arg_info
+ where
+ appArg acc (arg_cname, _, arg_hty, _)
+ = text "rts_apply"
+ <> parens (cap <> acc <> comma <> mkHObj arg_hty <> parens (cap <> arg_cname))
+
+ -- various other bits for inside the fn
+ declareResult = text "HaskellObj ret;"
+ declareCResult | res_hty_is_unit = empty
+ | otherwise = cResType <+> text "cret;"
+
+ assignCResult | res_hty_is_unit = empty
+ | otherwise =
+ text "cret=" <> unpackHObj res_hty <> parens (text "ret") <> semi
+
+ -- an extern decl for the fn being called
+ extern_decl
+ = case maybe_target of
+ Nothing -> empty
+ Just hs_fn -> text "extern StgClosure " <> ppr hs_fn <> text "_closure" <> semi
+
+
+ -- Initialise foreign exports by registering a stable pointer from an
+ -- __attribute__((constructor)) function.
+ -- The alternative is to do this from stginit functions generated in
+ -- codeGen/CodeGen.lhs; however, stginit functions have a negative impact
+ -- on binary sizes and link times because the static linker will think that
+ -- all modules that are imported directly or indirectly are actually used by
+ -- the program.
+ -- (this is bad for big umbrella modules like Graphics.Rendering.OpenGL)
+
+ initialiser
+ = case maybe_target of
+ Nothing -> empty
+ Just hs_fn ->
+ vcat
+ [ text "static void stginit_export_" <> ppr hs_fn
+ <> text "() __attribute__((constructor));"
+ , text "static void stginit_export_" <> ppr hs_fn <> text "()"
+ , braces (text "getStablePtr"
+ <> parens (text "(StgPtr) &" <> ppr hs_fn <> text "_closure")
+ <> semi)
+ ]
+
+ -- finally, the whole darn thing
+ c_bits =
+ space $$
+ extern_decl $$
+ fun_proto $$
+ vcat
+ [ lbrace
+ , text "Capability *cap;"
+ , declareResult
+ , declareCResult
+ , text "cap = rts_lock();"
+ -- create the application + perform it.
+ , text "cap=rts_evalIO" <> parens (
+ cap <>
+ text "rts_apply" <> parens (
+ cap <>
+ text "(HaskellObj)"
+ <> text (if is_IO_res_ty
+ then "runIO_closure"
+ else "runNonIO_closure")
+ <> comma
+ <> expr_to_run
+ ) <+> comma
+ <> text "&ret"
+ ) <> semi
+ , text "rts_checkSchedStatus" <> parens (doubleQuotes (ftext c_nm)
+ <> comma <> text "cap") <> semi
+ , assignCResult
+ , text "rts_unlock(cap);"
+ , if res_hty_is_unit then empty
+ else text "return cret;"
+ , rbrace
+ ] $$
+ initialiser
- paramArea =
- vcat (zipWith declVar ( res_ty : param_tys ) ( res_name : param_names ) )
+-- NB. the calculation here isn't strictly speaking correct.
+-- We have a primitive Haskell type (eg. Int#, Double#), and
+-- we want to know the size, when passed on the C stack, of
+-- the associated C type (eg. HsInt, HsDouble). We don't have
+-- this information to hand, but we know what GHC's conventions
+-- are for passing around the primitive Haskell types, so we
+-- use that instead. I hope the two coincide --SDM
+typeMachRep ty = argMachRep (typeCgRep ty)
- -- name of the (Haskell) helper function generated by the desugarer.
- h_nm = ppr helper
- h_stub_nm = text foreign_export_prefix <> h_nm
- closure = h_nm <> text "_closure"
+mkHObj :: Type -> SDoc
+mkHObj t = text "rts_mk" <> text (showFFIType t)
- param_names = zipWith (\ i _ -> h_stub_nm <> text ('_':show i)) [1..] args
- param_tys = map (ppr.typePrimRep) args
+unpackHObj :: Type -> SDoc
+unpackHObj t = text "rts_get" <> text (showFFIType t)
- (res_name, res_ty) =
- case res of
- Nothing -> (empty, empty)
- Just t -> (h_stub_nm <> text "_res", ppr (typePrimRep t))
+showStgType :: Type -> SDoc
+showStgType t = text "Hs" <> text (showFFIType t)
- startTemplate =
- vcat
- [ text "extern realWorldZh_closure;"
- , ptext SLIT("STGFUN") <> parens (h_stub_nm)
- , lbrace
- , ptext SLIT("FUNBEGIN;")
- , text "RestoreAllStgRegs();"
- , stackCheck param_names
- , pushRetReg
- , pushCont
- , pushRealWorld
- , vcat (map pushArg (reverse param_names))
- , text "Node=" <> closure <> semi
- , text "ENT_VIA_NODE();" -- ticky count
- , text "InfoPtr=(D_)(INFO_PTR(Node));"
- , text "JMP_(ENTRY_CODE(InfoPtr));"
- , text "FUNEND;"
- , rbrace
- ]
-
- stopTemplate =
- vcat
- [ ptext SLIT("STGFUN") <> parens (text "stop" <> h_stub_nm <> text "DirectReturn")
- , lbrace
- , ptext SLIT("FUNBEGIN;")
- , assignResult
- , popRetReg
- , text "#if defined(__STG_GCC_REGS__)"
- , text "SaveAllStgRegs();"
- , text "#else"
- , text "SAVE_Hp = Hp;"
- , text "SAVE_HpLim = HpLim;"
- , text "#endif"
- , text "JMP_(miniInterpretEnd);"
- , text "FUNEND;"
- , rbrace
- ]
-
- vtblTemplate =
- vcat
- [ text "const W_ vtbl_" <> h_stub_nm <> text "[] = {"
- , vcat (punctuate comma (replicate 8 dir_ret))
- , text "};"
- ]
- where
- dir_ret = text "(W_)stop" <> h_stub_nm <> text "DirectReturn"
-
- assignResult =
- case res of
- Nothing -> empty
- Just _ -> res_name <> equals <> text "R3.i;" -- wrong
-
- pushRetReg =
- text "SpB -= BREL(1);" $$
- text "*SpB = (W_)RetReg;"
-
- popRetReg =
- text "RetReg=(StgRetAddr)*SpB;" $$
- text "SpB += BREL(1);"
-
- pushCont =
- text "RetReg=(StgRetAddr)UNVEC(stop" <> h_stub_nm <>
- text "DirectReturn,vtbl_" <> h_stub_nm <> text ");"
-
- pushRealWorld =
- text "SpB -= BREL(1);" $$
- text "*SpB = (W_)realWorldZh_closure;"
-
-
- pushArg nm =
- text "SpB -= BREL(1);" $$
- text "*SpB = (W_)" <> nm <> semi
-
- stackCheck args =
- text "STK_CHK(LivenessReg,0," <> sz <> text ",0,0,0,0);"
- where
- sz = parens $
- hsep $ punctuate (text " + ") (text "1":(map sizer args))
-
- sizer x = text "BYTES_TO_STGWORDS" <> parens (text "sizeof" <> parens x)
-
-foreign_export_prefix :: String
-foreign_export_prefix = "__fexp_"
-
-mkCStub :: FAST_STRING -> SDoc -> [Type] -> Maybe Type -> CallConv -> (SDoc, SDoc)
-mkCStub c_nm h_stub_nm args res cc =
- ( hsep [ ptext SLIT("extern")
- , cResType
- , pprCconv
- , ptext c_nm
- , parens (hsep (punctuate comma (zipWith (<+>) stubParamTypes stubArgs)))
- , semi
- ]
- , vcat
- [ externDecls
- , cResType
- , pprCconv
- , ptext c_nm <> parens (hsep (punctuate comma stubArgs))
- , vcat (zipWith declVar stubParamTypes stubArgs)
- , lbrace
- , vcat (zipWith assignArgs param_names c_args)
- , text "miniInterpret" <> parens (parens (text "StgFunPtr") <> h_stub_nm) <> semi
- , returnResult
- , rbrace
- ]
- )
+showFFIType :: Type -> String
+showFFIType t = getOccString (getName tc)
where
- -- tedious hack to let us deal with caller-cleans-up-stack
- -- discipline that the C calling convention uses.
- stubParamTypes
- | cc == cCallConv = ptext SLIT("void*") : cParamTypes
- | otherwise = cParamTypes
- stubArgs
- | cc == cCallConv = ptext SLIT("_a0") : c_args
- | otherwise = c_args
-
- param_names = zipWith (\ i _ -> h_stub_nm <> text ('_':show i)) [1..] args
- cParamTypes = map (text.showPrimRepToUser.typePrimRep) args
- (cResType, cResDecl) =
- case res of
- Nothing -> (text "void", empty)
- Just t -> (text (showPrimRepToUser (typePrimRep t)),
- text "extern" <+> cResType <+> res_name <> semi)
-
- pprCconv
- | cc == cCallConv = empty
- | otherwise = pprCallConv cc
-
- externDecls =
- vcat (zipWith mkExtern cParamTypes param_names) $$
- cResDecl $$
- text "extern void" <+> h_stub_nm <> text "();"
-
- mkExtern ty nm = text "extern" <+> ty <+> nm <> semi
-
- c_args = zipWith (\ _ n -> text ('a':show n)) args [0..]
-
- assignArgs p_nm c_arg = p_nm <+> equals <+> c_arg <> semi
-
- returnResult =
- case res of
- Nothing -> empty
- Just _ -> text "return" <+> res_name <> semi
-
- (res_name, res_ty) =
- case res of
- Nothing -> (empty, empty)
- Just t -> (h_stub_nm <> text "_res", ppr (typePrimRep t))
-
-declVar :: SDoc -> SDoc -> SDoc
-declVar ty var = ty <+> var <> semi
-
+ tc = case tcSplitTyConApp_maybe (repType t) of
+ Just (tc,_) -> tc
+ Nothing -> pprPanic "showFFIType" (ppr t)
+
+#if !defined(x86_64_TARGET_ARCH)
+insertRetAddr CCallConv args = ret_addr_arg : args
+insertRetAddr _ args = args
+#else
+-- On x86_64 we insert the return address after the 6th
+-- integer argument, because this is the point at which we
+-- need to flush a register argument to the stack (See rts/Adjustor.c for
+-- details).
+insertRetAddr CCallConv args = go 0 args
+ where go 6 args = ret_addr_arg : args
+ go n (arg@(_,_,_,rep):args)
+ | I64 <- rep = arg : go (n+1) args
+ | otherwise = arg : go n args
+ go n [] = []
+insertRetAddr _ args = args
+#endif
+
+ret_addr_arg = (text "original_return_addr", text "void*", undefined,
+ typeMachRep addrPrimTy)
+
+-- This function returns the primitive type associated with the boxed
+-- type argument to a foreign export (eg. Int ==> Int#). It assumes
+-- that all the types we are interested in have a single constructor
+-- with a single primitive-typed argument, which is true for all of the legal
+-- foreign export argument types (see TcType.legalFEArgTyCon).
+getPrimTyOf :: Type -> Type
+getPrimTyOf ty =
+ case splitProductType_maybe (repType ty) of
+ Just (_, _, data_con, [prim_ty]) ->
+ ASSERT(dataConSourceArity data_con == 1)
+ ASSERT2(isUnLiftedType prim_ty, ppr prim_ty)
+ prim_ty
+ _other -> pprPanic "DsForeign.getPrimTyOf" (ppr ty)
\end{code}
-
-When exporting
-
- f :: Int -> Int -> Int -> IO Int
-
-we'll emit the following stuff into the .hc file
-
-\begin{pseudocode}
-StgInt __f_param_1;
-StgInt __f_param_2;
-StgInt __f_param_3;
-StgInt __f_res;
-
-STGFUN(ds_f)
-{
- FUNBEGIN;
- RestoreAllStgRegs();
- STK_CHK(LivenessReg,0/*A*/,(SIZE_IN_WORDS(StgInt) +
- SIZE_IN_WORDS(StgInt) +
- SIZE_IN_WORDS(StgInt) + 1)/*B*/, 0, 0, 0/*prim*/, 0/*re-enter*/);
- RetReg = (StgRetAddr) UNVEC(stopds_fDirectReturn,vtbl_stopds_f);
- SpB -= BREL(1);
- *SpB = (W_)__f_param_3;
- SpB -= BREL(1);
- *SpB = (W_)__f_param_2;
- SpB -= BREL(1);
- *SpB = (W_)__f_param_1;
-
- SpB -= BREL(1);
- *SpB = (W_) realWorldZh_closure;
-
- Node = ds_f_helper_closure;
- ENT_VIA_NODE();
- InfoPtr=(D_)(INFO_PTR(Node));
- JMP_(ENTRY_CODE(InfoPtr));
- FUNEND;
-}
-
-STGFUN(stop_ds_fDirectReturn)
-{
- FUNBEGIN;
- __f_res=R1.i;
- SaveAllStgRegs();
- RESUME(miniInterpretEnd);
- FUNEND;
-}
-
-const W_ vtbl_stopds_f[] = {
- (W_) stopds_fDirectReturn,
- (W_) stopds_fDirectReturn,
- (W_) stopds_fDirectReturn,
- (W_) stopds_fDirectReturn,
- (W_) stopds_fDirectReturn,
- (W_) stopds_fDirectReturn,
- (W_) stopds_fDirectReturn,
- (W_) stopds_fDirectReturn
-};
-
-\end{pseudocode}
-
-and a C stub
-
-\begin{pseudocode}
-extern StgInt __f_param_1;
-extern StgInt __f_param_2;
-extern StgInt __f_param_3;
-extern StgInt __f_res;
-
-extern void ds_f();
-extern void miniInterpret(StgAddr);
-
-int
-f(a1,a2,a3)
-int a1;
-int a2;
-int a3;
-{
- __f_param_1=a1;
- __f_param_2=a2;
- __f_param_3=a3;
- miniInterpret((StgAddr)ds_f);
- return (__f_res);
-}
-
-\end{pseudocode}
projects / ghc-hetmet.git / blobdiff