%
% (c) The AQUA Project, Glasgow University, 1994-1998
%
-\section[DsCCall]{Desugaring \tr{_ccall_}s and \tr{_casm_}s}
+\section[DsCCall]{Desugaring C calls}
\begin{code}
module DsCCall
#include "HsVersions.h"
+
import CoreSyn
import DsMonad
-import CoreUtils ( exprType )
-import Id ( Id, mkWildId, idType )
+import CoreUtils ( exprType, mkCoerce2 )
+import Id ( Id, mkWildId )
import MkId ( mkFCallId, realWorldPrimId, mkPrimOpId )
import Maybes ( maybeToBool )
import ForeignCall ( ForeignCall(..), CCallSpec(..), CCallTarget(..), Safety, CCallConv(..) )
import DataCon ( splitProductType_maybe, dataConSourceArity, dataConWrapId )
import ForeignCall ( ForeignCall, CCallTarget(..) )
-import TcType ( Type, isUnLiftedType, mkFunTys, mkFunTy,
+import TcType ( tcSplitTyConApp_maybe )
+import Type ( Type, isUnLiftedType, mkFunTys, mkFunTy,
tyVarsOfType, mkForAllTys, mkTyConApp,
- isBoolTy, isUnitTy, isPrimitiveType,
- tcSplitTyConApp_maybe
+ isPrimitiveType, splitTyConApp_maybe,
+ splitRecNewType_maybe, splitForAllTy_maybe,
+ isUnboxedTupleType
)
-import Type ( repType, eqType ) -- Sees the representation type
-import PrimOp ( PrimOp(TouchOp) )
-import TysPrim ( realWorldStatePrimTy,
+
+import PrimOp ( PrimOp(..) )
+import TysPrim ( realWorldStatePrimTy, intPrimTy,
byteArrayPrimTyCon, mutableByteArrayPrimTyCon,
- intPrimTy, foreignObjPrimTy
+ addrPrimTy
)
-import TyCon ( tyConDataCons )
+import TyCon ( TyCon, tyConDataCons, tyConName )
import TysWiredIn ( unitDataConId,
unboxedSingletonDataCon, unboxedPairDataCon,
unboxedSingletonTyCon, unboxedPairTyCon,
trueDataCon, falseDataCon,
- trueDataConId, falseDataConId
+ trueDataConId, falseDataConId,
+ listTyCon, charTyCon,
+ tupleTyCon, tupleCon
)
+import BasicTypes ( Boxity(..) )
import Literal ( mkMachInt )
import CStrings ( CLabelString )
-import PrelNames ( Unique, hasKey, ioTyConKey )
+import PrelNames ( Unique, hasKey, ioTyConKey, boolTyConKey, unitTyConKey,
+ int8TyConKey, int16TyConKey, int32TyConKey,
+ word8TyConKey, word16TyConKey, word32TyConKey
+ -- dotnet interop
+ , marshalStringName, unmarshalStringName
+ , marshalObjectName, unmarshalObjectName
+ , objectTyConName
+ )
import VarSet ( varSetElems )
+import Constants ( wORD_SIZE)
import Outputable
+
+#ifdef DEBUG
+import TypeRep
+#endif
+
\end{code}
Desugaring of @ccall@s consists of adding some state manipulation,
dsCCall :: CLabelString -- C routine to invoke
-> [CoreExpr] -- Arguments (desugared)
-> Safety -- Safety of the call
- -> Bool -- True <=> really a "_casm_"
-> Type -- Type of the result: IO t
-> DsM CoreExpr
-dsCCall lbl args may_gc is_asm result_ty
- = mapAndUnzipDs unboxArg args `thenDs` \ (unboxed_args, arg_wrappers) ->
- boxResult [] ({-repType-} result_ty) `thenDs` \ (ccall_result_ty, res_wrapper) ->
- getUniqueDs `thenDs` \ uniq ->
+dsCCall lbl args may_gc result_ty
+ = mapAndUnzipDs unboxArg args `thenDs` \ (unboxed_args, arg_wrappers) ->
+ boxResult [] id Nothing result_ty `thenDs` \ (ccall_result_ty, res_wrapper) ->
+ newUnique `thenDs` \ uniq ->
let
- target | is_asm = CasmTarget lbl
- | otherwise = StaticTarget lbl
+ target = StaticTarget lbl
the_fcall = CCall (CCallSpec target CCallConv may_gc)
the_prim_app = mkFCall uniq the_fcall unboxed_args ccall_result_ty
in
| isPrimitiveType arg_ty
= returnDs (arg, \body -> body)
+ -- Recursive newtypes
+ | Just rep_ty <- splitRecNewType_maybe arg_ty
+ = unboxArg (mkCoerce2 rep_ty arg_ty arg)
+
-- Booleans
- | isBoolTy arg_ty
+ | Just (tc,_) <- splitTyConApp_maybe arg_ty,
+ tc `hasKey` boolTyConKey
= newSysLocalDs intPrimTy `thenDs` \ prim_arg ->
returnDs (Var prim_arg,
\ body -> Case (Case arg (mkWildId arg_ty)
[(DEFAULT,[],body)])
-- Data types with a single constructor, which has a single, primitive-typed arg
- -- This deals with Int, Float etc
+ -- This deals with Int, Float etc; also Ptr, ForeignPtr
| is_product_type && data_con_arity == 1
- = ASSERT(isUnLiftedType data_con_arg_ty1 ) -- Typechecker ensures this
+ = ASSERT2(isUnLiftedType data_con_arg_ty1, pprType arg_ty)
+ -- Typechecker ensures this
newSysLocalDs arg_ty `thenDs` \ case_bndr ->
newSysLocalDs data_con_arg_ty1 `thenDs` \ prim_arg ->
returnDs (Var prim_arg,
\ body -> Case arg case_bndr [(DataAlt data_con,vars,body)]
)
+ | Just (tc, [arg_ty]) <- splitTyConApp_maybe arg_ty,
+ tc == listTyCon,
+ Just (cc,[]) <- splitTyConApp_maybe arg_ty,
+ cc == charTyCon
+ -- String; dotnet only
+ = dsLookupGlobalId marshalStringName `thenDs` \ unpack_id ->
+ newSysLocalDs addrPrimTy `thenDs` \ prim_string ->
+ returnDs (Var prim_string,
+ \ body ->
+ let
+ io_ty = exprType body
+ (Just (_,[io_arg])) = tcSplitTyConApp_maybe io_ty
+ in
+ mkApps (Var unpack_id)
+ [ Type io_arg
+ , arg
+ , Lam prim_string body
+ ])
+ | Just (tc, [arg_ty]) <- splitTyConApp_maybe arg_ty,
+ tyConName tc == objectTyConName
+ -- Object; dotnet only
+ = dsLookupGlobalId marshalObjectName `thenDs` \ unpack_id ->
+ newSysLocalDs addrPrimTy `thenDs` \ prim_obj ->
+ returnDs (Var prim_obj,
+ \ body ->
+ let
+ io_ty = exprType body
+ (Just (_,[io_arg])) = tcSplitTyConApp_maybe io_ty
+ in
+ mkApps (Var unpack_id)
+ [ Type io_arg
+ , arg
+ , Lam prim_obj body
+ ])
+
| otherwise
- = getSrcLocDs `thenDs` \ l ->
+ = getSrcSpanDs `thenDs` \ l ->
pprPanic "unboxArg: " (ppr l <+> ppr arg_ty)
where
- arg_ty = repType (exprType arg)
- -- The repType looks through any newtype or
- -- implicit-parameter wrappings on the argument;
- -- this is necessary, because isBoolTy (in particular) does not.
-
+ arg_ty = exprType arg
maybe_product_type = splitProductType_maybe arg_ty
is_product_type = maybeToBool maybe_product_type
Just (_, _, data_con, data_con_arg_tys) = maybe_product_type
(data_con_arg_ty1 : _) = data_con_arg_tys
(_ : _ : data_con_arg_ty3 : _) = data_con_arg_tys
- maybe_arg3_tycon = tcSplitTyConApp_maybe data_con_arg_ty3
+ maybe_arg3_tycon = splitTyConApp_maybe data_con_arg_ty3
Just (arg3_tycon,_) = maybe_arg3_tycon
\end{code}
\begin{code}
-boxResult :: [Id] -> Type -> DsM (Type, CoreExpr -> CoreExpr)
+boxResult :: [Id]
+ -> ((Maybe Type, CoreExpr -> CoreExpr) -> (Maybe Type, CoreExpr -> CoreExpr))
+ -> Maybe Id
+ -> Type
+ -> DsM (Type, CoreExpr -> CoreExpr)
-- Takes the result of the user-level ccall:
-- either (IO t),
-- the result type will be
-- State# RealWorld -> (# State# RealWorld #)
--- Here is where we arrange that ForeignPtrs which are passed to a 'safe'
--- foreign import don't get finalized until the call returns. For each
--- argument of type ForeignObj# we arrange to touch# the argument after
--- the call. The arg_ids passed in are the Ids passed to the actual ccall.
-
-boxResult arg_ids result_ty
+boxResult arg_ids augment mbTopCon result_ty
= case tcSplitTyConApp_maybe result_ty of
-- This split absolutely has to be a tcSplit, because we must
-- see the IO type; and it's a newtype which is transparent to splitTyConApp.
-- The result is IO t, so wrap the result in an IO constructor
Just (io_tycon, [io_res_ty]) | io_tycon `hasKey` ioTyConKey
- -> mk_alt return_result
- (resultWrapper io_res_ty) `thenDs` \ (ccall_res_ty, the_alt) ->
- newSysLocalDs realWorldStatePrimTy `thenDs` \ state_id ->
+ -> resultWrapper io_res_ty `thenDs` \ res ->
+ let aug_res = augment res
+ extra_result_tys =
+ case aug_res of
+ (Just ty,_)
+ | isUnboxedTupleType ty ->
+ let (Just (_, ls)) = splitTyConApp_maybe ty in tail ls
+ _ -> []
+ in
+ mk_alt (return_result extra_result_tys) aug_res
+ `thenDs` \ (ccall_res_ty, the_alt) ->
+ newSysLocalDs realWorldStatePrimTy `thenDs` \ state_id ->
let
io_data_con = head (tyConDataCons io_tycon)
+ toIOCon =
+ case mbTopCon of
+ Nothing -> dataConWrapId io_data_con
+ Just x -> x
wrap = \ the_call ->
- mkApps (Var (dataConWrapId io_data_con))
+ mkApps (Var toIOCon)
[ Type io_res_ty,
Lam state_id $
Case (App the_call (Var state_id))
in
returnDs (realWorldStatePrimTy `mkFunTy` ccall_res_ty, wrap)
where
- return_result state ans = mkConApp unboxedPairDataCon
- [Type realWorldStatePrimTy, Type io_res_ty,
- state, ans]
-
+ return_result ts state anss
+ = mkConApp (tupleCon Unboxed (2 + length ts))
+ (Type realWorldStatePrimTy : Type io_res_ty : map Type ts ++
+ state : anss)
-- It isn't, so do unsafePerformIO
-- It's not conveniently available, so we inline it
- other -> mk_alt return_result
- (resultWrapper result_ty) `thenDs` \ (ccall_res_ty, the_alt) ->
+ other -> resultWrapper result_ty `thenDs` \ res ->
+ mk_alt return_result (augment res) `thenDs` \ (ccall_res_ty, the_alt) ->
let
wrap = \ the_call -> Case (App the_call (Var realWorldPrimId))
(mkWildId ccall_res_ty)
in
returnDs (realWorldStatePrimTy `mkFunTy` ccall_res_ty, wrap)
where
- return_result state ans = ans
+ return_result state [ans] = ans
+ return_result _ _ = panic "return_result: expected single result"
where
mk_alt return_result (Nothing, wrap_result)
= -- The ccall returns ()
- let
- rhs_fun state_id = return_result (Var state_id)
- (wrap_result (panic "boxResult"))
- in
newSysLocalDs realWorldStatePrimTy `thenDs` \ state_id ->
- mkTouches arg_ids state_id rhs_fun `thenDs` \ the_rhs ->
let
+ the_rhs = return_result (Var state_id)
+ [wrap_result (panic "boxResult")]
+
ccall_res_ty = mkTyConApp unboxedSingletonTyCon [realWorldStatePrimTy]
the_alt = (DataAlt unboxedSingletonDataCon, [state_id], the_rhs)
in
returnDs (ccall_res_ty, the_alt)
mk_alt return_result (Just prim_res_ty, wrap_result)
- = -- The ccall returns a non-() value
- newSysLocalDs prim_res_ty `thenDs` \ result_id ->
+ -- The ccall returns a non-() value
+ | isUnboxedTupleType prim_res_ty
+ = let
+ Just (_, ls) = splitTyConApp_maybe prim_res_ty
+ arity = 1 + length ls
+ in
+ mappM newSysLocalDs ls `thenDs` \ args_ids@(result_id:as) ->
+ newSysLocalDs realWorldStatePrimTy `thenDs` \ state_id ->
let
- rhs_fun state_id = return_result (Var state_id)
- (wrap_result (Var result_id))
+ the_rhs = return_result (Var state_id)
+ (wrap_result (Var result_id) : map Var as)
+ ccall_res_ty = mkTyConApp (tupleTyCon Unboxed arity)
+ (realWorldStatePrimTy : ls)
+ the_alt = ( DataAlt (tupleCon Unboxed arity)
+ , (state_id : args_ids)
+ , the_rhs
+ )
in
+ returnDs (ccall_res_ty, the_alt)
+ | otherwise
+ = newSysLocalDs prim_res_ty `thenDs` \ result_id ->
newSysLocalDs realWorldStatePrimTy `thenDs` \ state_id ->
- mkTouches arg_ids state_id rhs_fun `thenDs` \ the_rhs ->
let
+ the_rhs = return_result (Var state_id)
+ [wrap_result (Var result_id)]
+
ccall_res_ty = mkTyConApp unboxedPairTyCon [realWorldStatePrimTy, prim_res_ty]
the_alt = (DataAlt unboxedPairDataCon, [state_id, result_id], the_rhs)
in
returnDs (ccall_res_ty, the_alt)
-touchzh = mkPrimOpId TouchOp
-
-mkTouches [] s cont = returnDs (cont s)
-mkTouches (v:vs) s cont
- | not (idType v `eqType` foreignObjPrimTy) = mkTouches vs s cont
- | otherwise = newSysLocalDs realWorldStatePrimTy `thenDs` \s' ->
- mkTouches vs s' cont `thenDs` \ rest ->
- returnDs (Case (mkApps (Var touchzh) [Type foreignObjPrimTy,
- Var v, Var s]) s'
- [(DEFAULT, [], rest)])
resultWrapper :: Type
- -> (Maybe Type, -- Type of the expected result, if any
- CoreExpr -> CoreExpr) -- Wrapper for the result
+ -> DsM (Maybe Type, -- Type of the expected result, if any
+ CoreExpr -> CoreExpr) -- Wrapper for the result
resultWrapper result_ty
-- Base case 1: primitive types
- | isPrimitiveType result_ty_rep
- = (Just result_ty, \e -> e)
+ | isPrimitiveType result_ty
+ = returnDs (Just result_ty, \e -> e)
-- Base case 2: the unit type ()
- | isUnitTy result_ty_rep
- = (Nothing, \e -> Var unitDataConId)
-
- -- Base case 3: the boolean type ()
- | isBoolTy result_ty_rep
- = (Just intPrimTy, \e -> Case e (mkWildId intPrimTy)
- [(DEFAULT ,[],Var trueDataConId ),
- (LitAlt (mkMachInt 0),[],Var falseDataConId)])
+ | Just (tc,_) <- maybe_tc_app, tc `hasKey` unitTyConKey
+ = returnDs (Nothing, \e -> Var unitDataConId)
+
+ -- Base case 3: the boolean type
+ | Just (tc,_) <- maybe_tc_app, tc `hasKey` boolTyConKey
+ = returnDs
+ (Just intPrimTy, \e -> Case e (mkWildId intPrimTy)
+ [(DEFAULT ,[],Var trueDataConId ),
+ (LitAlt (mkMachInt 0),[],Var falseDataConId)])
+
+ -- Recursive newtypes
+ | Just rep_ty <- splitRecNewType_maybe result_ty
+ = resultWrapper rep_ty `thenDs` \ (maybe_ty, wrapper) ->
+ returnDs (maybe_ty, \e -> mkCoerce2 result_ty rep_ty (wrapper e))
+
+ -- The type might contain foralls (eg. for dummy type arguments,
+ -- referring to 'Ptr a' is legal).
+ | Just (tyvar, rest) <- splitForAllTy_maybe result_ty
+ = resultWrapper rest `thenDs` \ (maybe_ty, wrapper) ->
+ returnDs (maybe_ty, \e -> Lam tyvar (wrapper e))
-- Data types with a single constructor, which has a single arg
- | Just (_, tycon_arg_tys, data_con, data_con_arg_tys) <- splitProductType_maybe result_ty_rep,
+ -- This includes types like Ptr and ForeignPtr
+ | Just (tycon, tycon_arg_tys, data_con, data_con_arg_tys) <- splitProductType_maybe result_ty,
dataConSourceArity data_con == 1
= let
- (maybe_ty, wrapper) = resultWrapper unwrapped_res_ty
(unwrapped_res_ty : _) = data_con_arg_tys
+ narrow_wrapper = maybeNarrow tycon
in
- (maybe_ty, \e -> mkApps (Var (dataConWrapId data_con))
- (map Type tycon_arg_tys ++ [wrapper e]))
+ resultWrapper unwrapped_res_ty `thenDs` \ (maybe_ty, wrapper) ->
+ returnDs
+ (maybe_ty, \e -> mkApps (Var (dataConWrapId data_con))
+ (map Type tycon_arg_tys ++ [wrapper (narrow_wrapper e)]))
+
+ -- Strings; 'dotnet' only.
+ | Just (tc, [arg_ty]) <- maybe_tc_app, tc == listTyCon,
+ Just (cc,[]) <- splitTyConApp_maybe arg_ty, cc == charTyCon
+ = dsLookupGlobalId unmarshalStringName `thenDs` \ pack_id ->
+ returnDs (Just addrPrimTy,
+ \ e -> App (Var pack_id) e)
+
+ -- Objects; 'dotnet' only.
+ | Just (tc, [arg_ty]) <- maybe_tc_app,
+ tyConName tc == objectTyConName
+ = dsLookupGlobalId unmarshalObjectName `thenDs` \ pack_id ->
+ returnDs (Just addrPrimTy,
+ \ e -> App (Var pack_id) e)
| otherwise
= pprPanic "resultWrapper" (ppr result_ty)
where
- result_ty_rep = repType result_ty -- Look through any newtypes/implicit parameters
+ maybe_tc_app = splitTyConApp_maybe result_ty
+
+-- When the result of a foreign call is smaller than the word size, we
+-- need to sign- or zero-extend the result up to the word size. The C
+-- standard appears to say that this is the responsibility of the
+-- caller, not the callee.
+
+maybeNarrow :: TyCon -> (CoreExpr -> CoreExpr)
+maybeNarrow tycon
+ | tycon `hasKey` int8TyConKey = \e -> App (Var (mkPrimOpId Narrow8IntOp)) e
+ | tycon `hasKey` int16TyConKey = \e -> App (Var (mkPrimOpId Narrow16IntOp)) e
+ | tycon `hasKey` int32TyConKey
+ && wORD_SIZE > 4 = \e -> App (Var (mkPrimOpId Narrow32IntOp)) e
+
+ | tycon `hasKey` word8TyConKey = \e -> App (Var (mkPrimOpId Narrow8WordOp)) e
+ | tycon `hasKey` word16TyConKey = \e -> App (Var (mkPrimOpId Narrow16WordOp)) e
+ | tycon `hasKey` word32TyConKey
+ && wORD_SIZE > 4 = \e -> App (Var (mkPrimOpId Narrow32WordOp)) e
+ | otherwise = id
\end{code}