+++ /dev/null
-%
-% (c) The AQUA Project, Glasgow University, 1998
-%
-\section[DsCCall]{Desugaring \tr{foreign} declarations}
-
-Expanding out @foreign import@ and @foreign export@ declarations.
-
-\begin{code}
-module DsForeign ( dsForeigns ) where
-
-#include "HsVersions.h"
-import TcRnMonad -- temp
-
-import CoreSyn
-
-import DsCCall ( dsCCall, mkFCall, boxResult, unboxArg, resultWrapper )
-import DsMonad
-
-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 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
-\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}
-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 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.
-
-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
- -> 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
- 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}
-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) ->
-
- 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) ->
-
- 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)
-
-unsafe_call (CCall (CCallSpec _ _ safety)) = playSafe safety
-unsafe_call (DNCall _) = False
-\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
- into.)
-
-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@'.
-
-\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
- -- 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
-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 dynamic f :: (Addr -> Int -> IO Int) -> IO Addr
-
--- 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 =
- 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
--- first argument.
-\end{verbatim}
-
-\begin{code}
-dsFExportDynamic :: 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 = mkFastString (unpackFS (zEncodeFS (moduleFS mod_name)) ++ "_" ++ toCName fe_id)
- in
- newSysLocalDs arg_ty `thenDs` \ cback ->
- dsLookupGlobalId newStablePtrName `thenDs` \ newStablePtrId ->
- dsLookupTyCon stablePtrTyConName `thenDs` \ stable_ptr_tycon ->
- let
- 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
- 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
- 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
-
- 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)
-
- 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{Generating @foreign export@ stubs}
-%
-%*
-
-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}
-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
- -- 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
-
--- 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)
-
-mkHObj :: Type -> SDoc
-mkHObj t = text "rts_mk" <> text (showFFIType t)
-
-unpackHObj :: Type -> SDoc
-unpackHObj t = text "rts_get" <> text (showFFIType t)
-
-showStgType :: Type -> SDoc
-showStgType t = text "Hs" <> text (showFFIType t)
-
-showFFIType :: Type -> String
-showFFIType t = getOccString (getName tc)
- where
- 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}
projects / ghc-hetmet.git / blobdiff