%
+% (c) The University of Glasgow 2006
% (c) The AQUA Project, Glasgow University, 1994-1998
%
-\section[DsCCall]{Desugaring C calls}
+
+Desugaring foreign calls
\begin{code}
module DsCCall
import DsMonad
-import CoreUtils ( exprType, coreAltType, mkCoerce2 )
-import Id ( Id, mkWildId )
-import MkId ( mkFCallId, realWorldPrimId, mkPrimOpId )
-import Maybes ( maybeToBool )
-import ForeignCall ( ForeignCall(..), CCallSpec(..), CCallTarget(..), Safety,
- CCallConv(..), CLabelString )
-import DataCon ( splitProductType_maybe, dataConSourceArity, dataConWrapId )
-
-import TcType ( tcSplitTyConApp_maybe )
-import Type ( Type, isUnLiftedType, mkFunTys, mkFunTy,
- tyVarsOfType, mkForAllTys, mkTyConApp,
- isPrimitiveType, splitTyConApp_maybe,
- splitRecNewType_maybe, splitForAllTy_maybe,
- isUnboxedTupleType
- )
-
-import PrimOp ( PrimOp(..) )
-import TysPrim ( realWorldStatePrimTy, intPrimTy,
- byteArrayPrimTyCon, mutableByteArrayPrimTyCon,
- addrPrimTy
- )
-import TyCon ( TyCon, tyConDataCons, tyConName )
-import TysWiredIn ( unitDataConId,
- unboxedSingletonDataCon, unboxedPairDataCon,
- unboxedSingletonTyCon, unboxedPairTyCon,
- trueDataCon, falseDataCon,
- trueDataConId, falseDataConId,
- listTyCon, charTyCon, boolTy,
- tupleTyCon, tupleCon
- )
-import BasicTypes ( Boxity(..) )
-import Literal ( mkMachInt )
-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 CoreUtils
+import Id
+import MkId
+import Maybes
+import ForeignCall
+import DataCon
+
+import TcType
+import Type
+import Coercion
+import PrimOp
+import TysPrim
+import TyCon
+import TysWiredIn
+import BasicTypes
+import Literal
+import PrelNames
+import VarSet
+import Constants
import Outputable
#ifdef DEBUG
-> [CoreExpr] -- Arguments (desugared)
-> Safety -- Safety of the call
-> Type -- Type of the result: IO t
- -> DsM CoreExpr
+ -> DsM CoreExpr -- Result, of type ???
dsCCall lbl args may_gc result_ty
= mapAndUnzipDs unboxArg args `thenDs` \ (unboxed_args, arg_wrappers) ->
= returnDs (arg, \body -> body)
-- Recursive newtypes
- | Just rep_ty <- splitRecNewType_maybe arg_ty
- = unboxArg (mkCoerce2 rep_ty arg_ty arg)
+ | Just(rep_ty, co) <- splitNewTypeRepCo_maybe arg_ty
+ = unboxArg (mkCoerce co arg)
-- Booleans
| Just (tc,_) <- splitTyConApp_maybe arg_ty,
\ body ->
let
io_ty = exprType body
- (Just (_,[io_arg])) = tcSplitTyConApp_maybe io_ty
+ Just (_,io_arg) = tcSplitIOType_maybe io_ty
in
mkApps (Var unpack_id)
[ Type io_arg
\ body ->
let
io_ty = exprType body
- (Just (_,[io_arg])) = tcSplitTyConApp_maybe io_ty
+ Just (_,io_arg) = tcSplitIOType_maybe io_ty
in
mkApps (Var unpack_id)
[ Type io_arg
-- where t' is the unwrapped form of t. If t is simply (), then
-- the result type will be
-- State# RealWorld -> (# State# RealWorld #)
+--
+-- The gruesome 'augment' and 'mbTopCon' are to do with .NET foreign calls
+-- It looks a mess: I wonder if it could be refactored.
+
+boxResult augment mbTopCon result_ty
+ | Just (io_tycon, io_res_ty) <- tcSplitIOType_maybe result_ty
+ -- isIOType_maybe handles the case where the type is a
+ -- simple wrapping of IO. E.g.
+ -- newtype Wrap a = W (IO a)
+ -- No coercion necessay because its a non-recursive newtype
+ -- (If we wanted to handle a *recursive* newtype too, we'd need
+ -- another case, and a coercion.)
+ = -- The result is IO t, so wrap the result in an IO constructor
+
+ 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
+ _ -> []
+
+ return_result state anss
+ = mkConApp (tupleCon Unboxed (2 + length extra_result_tys))
+ (map Type (realWorldStatePrimTy : io_res_ty : extra_result_tys)
+ ++ (state : anss))
+ in
+ mk_alt return_result 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 toIOCon)
+ [ Type io_res_ty,
+ Lam state_id $
+ Case (App the_call (Var state_id))
+ (mkWildId ccall_res_ty)
+ (coreAltType the_alt)
+ [the_alt]
+ ]
+ in
+ returnDs (realWorldStatePrimTy `mkFunTy` ccall_res_ty, wrap)
boxResult 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
- -> 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 toIOCon)
- [ Type io_res_ty,
- Lam state_id $
- Case (App the_call (Var state_id))
- (mkWildId ccall_res_ty)
- (coreAltType the_alt)
- [the_alt]
- ]
- in
- returnDs (realWorldStatePrimTy `mkFunTy` ccall_res_ty, wrap)
- where
- 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 isn't IO, so do unsafePerformIO
-- It's not conveniently available, so we inline it
- 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))
+ 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)
(coreAltType the_alt)
[the_alt]
- in
- returnDs (realWorldStatePrimTy `mkFunTy` ccall_res_ty, wrap)
- where
- return_result state [ans] = ans
- return_result _ _ = panic "return_result: expected single result"
+ in
+ returnDs (realWorldStatePrimTy `mkFunTy` ccall_res_ty, wrap)
where
- mk_alt return_result (Nothing, wrap_result)
- = -- The ccall returns ()
+ return_result state [ans] = ans
+ return_result _ _ = panic "return_result: expected single result"
+
+
+mk_alt return_result (Nothing, wrap_result)
+ = -- The ccall returns ()
newSysLocalDs realWorldStatePrimTy `thenDs` \ state_id ->
let
the_rhs = return_result (Var state_id)
in
returnDs (ccall_res_ty, the_alt)
- mk_alt return_result (Just prim_res_ty, wrap_result)
+mk_alt return_result (Just prim_res_ty, wrap_result)
-- 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
- 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 ->
- let
- the_rhs = return_result (Var state_id)
- [wrap_result (Var result_id)]
+ | 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
+ 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)
- 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)
+ | otherwise
+ = newSysLocalDs prim_res_ty `thenDs` \ result_id ->
+ newSysLocalDs realWorldStatePrimTy `thenDs` \ state_id ->
+ 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)
resultWrapper :: Type
(LitAlt (mkMachInt 0),[],Var falseDataConId)])
-- Recursive newtypes
- | Just rep_ty <- splitRecNewType_maybe result_ty
+ | Just (rep_ty, co) <- splitNewTypeRepCo_maybe result_ty
= resultWrapper rep_ty `thenDs` \ (maybe_ty, wrapper) ->
- returnDs (maybe_ty, \e -> mkCoerce2 result_ty rep_ty (wrapper e))
+ returnDs (maybe_ty, \e -> mkCoerce (mkSymCoercion co) (wrapper e))
-- The type might contain foralls (eg. for dummy type arguments,
-- referring to 'Ptr a' is legal).
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