IMP_Ubiq()
+import CmdLineOpts (opt_PprUserLength)
import CoreSyn
import DsMonad
import DsUtils
import CoreUtils ( coreExprType )
-import Id ( dataConArgTys, mkTupleCon )
+import Id ( Id(..), dataConArgTys, dataConTyCon, idType )
import Maybes ( maybeToBool )
-import PprStyle ( PprStyle(..) )
+import Outputable ( PprStyle(..), Outputable(..) )
import PprType ( GenType{-instances-} )
import Pretty
import PrelVals ( packStringForCId )
import PrimOp ( PrimOp(..) )
-import Type ( isPrimType, maybeAppDataTyConExpandingDicts, eqTy, maybeBoxedPrimType )
-import TysPrim ( byteArrayPrimTy, realWorldTy, realWorldStatePrimTy )
+import Type ( isPrimType, maybeAppDataTyConExpandingDicts, maybeAppTyCon,
+ eqTy, maybeBoxedPrimType, SYN_IE(Type), GenType(..),
+ splitFunTy, splitForAllTy, splitAppTys )
+import TyCon ( tyConDataCons )
+import TysPrim ( byteArrayPrimTy, realWorldTy, realWorldStatePrimTy,
+ byteArrayPrimTyCon, mutableByteArrayPrimTyCon )
import TysWiredIn ( getStatePairingConInfo,
- realWorldStateTy, stateDataCon,
- stringTy
+ unitDataCon, stringTy,
+ realWorldStateTy, stateDataCon
)
import Util ( pprPanic, pprError, panic )
+
\end{code}
Desugaring of @ccall@s consists of adding some state manipulation,
-> [CoreExpr] -- Arguments (desugared)
-> Bool -- True <=> might cause Haskell GC
-> Bool -- True <=> really a "_casm_"
- -> Type -- Type of the result (a boxed-prim type)
+ -> Type -- Type of the result (a boxed-prim IO type)
-> DsM CoreExpr
-dsCCall label args may_gc is_asm result_ty
- = newSysLocalDs realWorldStateTy `thenDs` \ old_s ->
+dsCCall label args may_gc is_asm io_result_ty
+ = newSysLocalDs realWorldStatePrimTy `thenDs` \ old_s ->
- mapAndUnzipDs unboxArg (Var old_s : args) `thenDs` \ (final_args, arg_wrappers) ->
+ mapAndUnzipDs unboxArg args `thenDs` \ (unboxed_args, arg_wrappers) ->
+ let
+ final_args = Var old_s : unboxed_args
+ (ioOkDataCon, result_ty) = getIoOkDataCon io_result_ty
+ in
- boxResult result_ty `thenDs` \ (final_result_ty, res_wrapper) ->
+ boxResult ioOkDataCon result_ty `thenDs` \ (final_result_ty, res_wrapper) ->
let
the_ccall_op = CCallOp label is_asm may_gc
\begin{code}
unboxArg :: CoreExpr -- The supplied argument
- -> DsM (CoreExpr, -- To pass as the actual argument
+ -> DsM (CoreExpr, -- To pass as the actual argument
CoreExpr -> CoreExpr -- Wrapper to unbox the arg
)
unboxArg arg
-- Primitive types
-- ADR Question: can this ever be used? None of the PrimTypes are
-- instances of the CCallable class.
+ --
+ -- SOF response:
+ -- Oh yes they are, I've just added them :-) Having _ccall_ and _casm_
+ -- that accept unboxed arguments is a Good Thing if you have a stub generator
+ -- which generates the boiler-plate box-unbox code for you, i.e., it may help
+ -- us nuke this very module :-)
+ --
| isPrimType arg_ty
= returnDs (arg, \body -> body)
-- oops: we can't see the data constructors!!!
= can't_see_datacons_error "argument" arg_ty
- -- Byte-arrays, both mutable and otherwise
- -- (HACKy method -- but we really don't want the TyCons wired-in...) [WDP 94/10]
+ -- Byte-arrays, both mutable and otherwise; hack warning
| is_data_type &&
length data_con_arg_tys == 2 &&
- not (isPrimType data_con_arg_ty1) &&
- isPrimType data_con_arg_ty2
+ maybeToBool maybe_arg2_tycon &&
+ (arg2_tycon == byteArrayPrimTyCon ||
+ arg2_tycon == mutableByteArrayPrimTyCon)
-- and, of course, it is an instance of CCallable
--- ( tycon == byteArrayTyCon ||
--- tycon == mutableByteArrayTyCon )
= newSysLocalsDs data_con_arg_tys `thenDs` \ vars@[ixs_var, arr_cts_var] ->
returnDs (Var arr_cts_var,
\ body -> Case arg (AlgAlts [(the_data_con,vars,body)]
data_con_arg_tys = dataConArgTys the_data_con tycon_arg_tys
(data_con_arg_ty1 : data_con_arg_ty2 : _) = data_con_arg_tys
+ maybe_arg2_tycon = maybeAppTyCon data_con_arg_ty2
+ Just (arg2_tycon,_) = maybe_arg2_tycon
+
can't_see_datacons_error thing ty
= pprError "ERROR: Can't see the data constructor(s) for _ccall_/_casm_ "
- (ppBesides [ppStr thing, ppStr "; type: ", ppr PprForUser ty])
+ (hcat [text thing, text "; type: ", ppr (PprForUser opt_PprUserLength) ty, text "(try compiling with -fno-prune-tydecls ..)\n"])
\end{code}
\begin{code}
-tuple_con_2 = mkTupleCon 2 -- out here to avoid CAF (sigh)
-covar_tuple_con_0 = Var (mkTupleCon 0) -- ditto
-
-boxResult :: Type -- Type of desired result
+boxResult :: Id -- IOok constructor
+ -> Type -- Type of desired result
-> DsM (Type, -- Type of the result of the ccall itself
CoreExpr -> CoreExpr) -- Wrapper for the ccall
- -- to box the result
-boxResult result_ty
+ -- to box the result
+boxResult ioOkDataCon result_ty
| null data_cons
-- oops! can't see the data constructors
= can't_see_datacons_error "result" result_ty
- -- Data types with a single constructor, which has a single, primitive-typed arg
- | (maybeToBool maybe_data_type) && -- Data type
- (null other_data_cons) && -- Just one constr
- not (null data_con_arg_tys) && null other_args_tys && -- Just one arg
- isPrimType the_prim_result_ty -- of primitive type
+ -- Data types with a single constructor,
+ -- which has a single, primitive-typed arg.
+ | (maybeToBool maybe_data_type) && -- Data type
+ (null other_data_cons) && -- Just one constr
+ not (null data_con_arg_tys) && null other_args_tys && -- Just one arg
+ isPrimType the_prim_result_ty -- of primitive type
=
- newSysLocalDs realWorldStatePrimTy `thenDs` \ prim_state_id ->
- newSysLocalDs the_prim_result_ty `thenDs` \ prim_result_id ->
+ newSysLocalDs realWorldStatePrimTy `thenDs` \ prim_state_id ->
+ newSysLocalDs the_prim_result_ty `thenDs` \ prim_result_id ->
- mkConDs stateDataCon [TyArg realWorldTy, VarArg (Var prim_state_id)] `thenDs` \ new_state ->
mkConDs the_data_con (map TyArg tycon_arg_tys ++ [VarArg (Var prim_result_id)]) `thenDs` \ the_result ->
- mkConDs tuple_con_2
- [TyArg result_ty, TyArg realWorldStateTy, VarArg the_result, VarArg new_state]
+ mkConDs ioOkDataCon
+ [TyArg result_ty, VarArg (Var prim_state_id), VarArg the_result]
`thenDs` \ the_pair ->
let
the_alt = (state_and_prim_datacon, [prim_state_id, prim_result_id], the_pair)
=
newSysLocalDs realWorldStatePrimTy `thenDs` \ prim_state_id ->
- mkConDs stateDataCon [TyArg realWorldTy, VarArg (Var prim_state_id)]
- `thenDs` \ new_state ->
- mkConDs tuple_con_2
- [TyArg result_ty, TyArg realWorldStateTy, VarArg covar_tuple_con_0, VarArg new_state]
+ mkConDs ioOkDataCon
+ [TyArg result_ty, VarArg (Var prim_state_id), VarArg (Var unitDataCon)]
`thenDs` \ the_pair ->
let
(state_and_prim_datacon, state_and_prim_ty) = getStatePairingConInfo the_prim_result_ty
\end{code}
+This grimy bit of code is for digging out the IOok constructor from an
+application of the the IO type. The constructor is needed for
+wrapping the result of a _ccall_. The alternative is to wire-in IO,
+which brings a whole heap of junk with it.
+
+If the representation of IO changes, this will probably have to be
+brought in line with the new definition.
+
+newtype IO a = IO (State# RealWorld -> IOResult a)
+
+the constructor IO has type (State# RealWorld -> IOResult a) -> IO a
+
+\begin{code}
+getIoOkDataCon :: Type -> (Id,Type)
+getIoOkDataCon io_result_ty =
+ let
+ AppTy (TyConTy ioTyCon _) result_ty = io_result_ty
+ [ioDataCon] = tyConDataCons ioTyCon
+ ioDataConTy = idType ioDataCon
+ (_,ioDataConTy') = splitForAllTy ioDataConTy
+ ([arg],_) = splitFunTy ioDataConTy'
+ (_,AppTy (TyConTy ioResultTyCon _) _) = splitFunTy arg
+ [ioOkDataCon,ioFailDataCon] = tyConDataCons ioResultTyCon
+ in
+ (ioOkDataCon, result_ty)
+
+\end{code}
+
+Another way to do it, more sensitive:
+
+ case ioDataConTy of
+ ForAll _ (FunTy (FunTy _ (AppTy (TyConTy ioResultTyCon _) _)) _) ->
+ let [ioOkDataCon,ioFailDataCon] = tyConDataCons ioResultTyCon
+ in
+ (ioOkDataCon, result_ty)
+ _ -> pprPanic "getIoOkDataCon: " (ppr PprDebug ioDataConTy)
projects / ghc-hetmet.git / blobdiff