%
+% (c) The University of Glasgow 2006
% (c) The AQUA Project, Glasgow University, 1998
%
-\section[DsCCall]{Desugaring \tr{foreign} declarations}
-Expanding out @foreign import@ and @foreign export@ declarations.
+Desugaring foreign declarations (see also DsCCall).
\begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
module DsForeign ( dsForeigns ) where
#include "HsVersions.h"
import CoreSyn
-import DsCCall ( dsCCall, mkFCall, boxResult, unboxArg, resultWrapper )
+import DsCCall
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 ( moduleNameFS, moduleName )
-import Name ( getOccString, NamedThing(..) )
-import Type ( repType, coreEqType )
-import TcType ( Type, mkFunTys, mkForAllTys, mkTyConApp,
- mkFunTy, tcSplitTyConApp_maybe, tcSplitIOType_maybe,
- tcSplitForAllTys, tcSplitFunTys, tcTyConAppArgs,
- isBoolTy
- )
-
-import BasicTypes ( Boxity(..) )
-import HscTypes ( ForeignStubs(..) )
-import ForeignCall ( ForeignCall(..), CCallSpec(..),
- Safety(..),
- CExportSpec(..), CLabelString,
- CCallConv(..), ccallConvToInt,
- ccallConvAttribute
- )
-import TysWiredIn ( unitTy, tupleTyCon )
-import TysPrim ( addrPrimTy, mkStablePtrPrimTy, alphaTy, intPrimTy )
-import PrelNames ( stablePtrTyConName, newStablePtrName, bindIOName,
- checkDotnetResName )
-import BasicTypes ( Activation( NeverActive ) )
-import SrcLoc ( Located(..), unLoc )
+import HsSyn
+import DataCon
+import MachOp
+import SMRep
+import CoreUtils
+import Id
+import Literal
+import Module
+import Name
+import Type
+import Coercion
+import TcType
+
+import HscTypes
+import ForeignCall
+import TysWiredIn
+import TysPrim
+import PrelNames
+import BasicTypes
+import SrcLoc
import Outputable
-import Maybe ( fromJust, isNothing )
import FastString
+import Config
+import Constants
+
+import Data.Maybe
+import Data.List
\end{code}
Desugaring of @foreign@ declarations is naturally split up into
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)
+ = do
+ fives <- mapM do_ldecl fos
+ let
+ (hs, cs, hdrs, idss, bindss) = unzip5 fives
+ fe_ids = concat idss
+ fe_init_code = map foreignExportInitialiser fe_ids
+ --
+ return (ForeignStubs
+ (vcat hs)
+ (vcat cs $$ vcat fe_init_code)
+ (nub (concat hdrs)),
+ (concat bindss))
+ where
+ do_ldecl (L loc decl) = putSrcSpanDs loc (do_decl decl)
+
+ do_decl (ForeignImport id _ spec)
= traceIf (text "fi start" <+> ppr id) `thenDs` \ _ ->
dsFImport (unLoc id) spec `thenDs` \ (bs, h, c, mbhd) ->
traceIf (text "fi end" <+> ppr id) `thenDs` \ _ ->
- returnDs (ForeignStubs (h $$ 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)))
+ returnDs (h, c, maybeToList mbhd, [], bs)
+
+ do_decl (ForeignExport (L _ id) _ (CExport (CExportStatic ext_nm cconv)))
= dsFExport id (idType id)
ext_nm cconv False `thenDs` \(h, c, _, _) ->
- 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
+ returnDs (h, c, [], [id], [])
\end{code}
-- 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
+ , String -- string describing type to pass to createAdj.
, Int -- size of args to stub function
)
-- If it's IO t, return (t, True)
-- If it's plain t, return (t, False)
(case tcSplitIOType_maybe orig_res_ty of
- Just (ioTyCon, res_ty) -> returnDs (res_ty, True)
+ Just (ioTyCon, res_ty, co) -> returnDs (res_ty, True)
-- The function already returns IO t
+ -- ToDo: what about the coercion?
Nothing -> returnDs (orig_res_ty, False)
-- The function returns t
) `thenDs` \ (res_ty, -- t
f cback =
bindIO (newStablePtr cback)
(\StablePtr sp# -> IO (\s1# ->
- case _ccall_ createAdjustor cconv sp# ``f_helper'' s1# of
+ case _ccall_ createAdjustor cconv sp# ``f_helper'' <arg info> s1# of
(# s2#, a# #) -> (# s2#, A# a# #)))
foreign import "&f_helper" f_helper :: FunPtr (StablePtr Fun -> Fun)
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) ->
+ `thenDs` \ (h_code, c_code, typestring, 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
adj_args = [ mkIntLitInt (ccallConvToInt cconv)
, Var stbl_value
, mkLit (MachLabel fe_nm mb_sz_args)
- , mkLit (mkStringLit arg_type_info)
+ , mkLit (mkStringLit typestring)
]
-- 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.
_ -> Nothing
in
- dsCCall adjustor adj_args PlayRisky io_res_ty `thenDs` \ ccall_adj ->
+ dsCCall adjustor adj_args PlayRisky (mkTyConApp io_tc [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
+
+ let io_app = mkLams tvs $
+ Lam cback $
+ mkCoerceI (mkSymCoI co) $
+ mkApps (Var bindIOId)
+ [ Type stable_ptr_ty
+ , Type res_ty
+ , mkApps (Var newStablePtrId) [ Type arg_ty, Var cback ]
+ , Lam stbl_value ccall_adj
+ ]
+
fed = (id `setInlinePragma` NeverActive, io_app)
-- Never inline the f.e.d. function, because the litlit
-- might not be in scope in other modules.
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
+ ty = idType id
+ (tvs,sans_foralls) = tcSplitForAllTys ty
+ ([arg_ty], fn_res_ty) = tcSplitFunTys sans_foralls
+ Just (io_tc, res_ty, co) = tcSplitIOType_maybe fn_res_ty
+ -- Must have an IO type; hence Just
+ -- co : fn_res_ty ~ IO res_ty
toCName :: Id -> String
toCName i = showSDoc (pprCode CStyle (ppr (idName i)))
-> CCallConv
-> (SDoc,
SDoc,
- [MachRep], -- the argument reps
+ String, -- 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
+ = (header_bits, c_bits, type_string,
sum [ machRepByteWidth rep | (_,_,_,rep) <- aug_arg_info] -- all the args
)
where
SDoc, -- C type
Type, -- Haskell type
MachRep)] -- the MachRep
- arg_info = [ (text ('a':show n), showStgType ty, ty,
+ arg_info = [ let stg_type = showStgType ty in
+ (arg_cname n stg_type,
+ stg_type,
+ ty,
typeMachRep (getPrimTyOf ty))
- | (ty,n) <- zip arg_htys [1..] ]
+ | (ty,n) <- zip arg_htys [1::Int ..] ]
+
+ arg_cname n stg_ty
+ | libffi = char '*' <> parens (stg_ty <> char '*') <>
+ ptext SLIT("args") <> brackets (int (n-1))
+ | otherwise = text ('a':show n)
+
+ -- generate a libffi-style stub if this is a "wrapper" and libffi is enabled
+ libffi = cLibFFI && isNothing maybe_target
+
+ type_string
+ -- libffi needs to know the result type too:
+ | libffi = primTyDescChar res_hty : arg_type_string
+ | otherwise = arg_type_string
+
+ arg_type_string = [primTyDescChar ty | (_,_,ty,_) <- arg_info]
+ -- just the real args
-- add some auxiliary args; the stable ptr in the wrapper case, and
-- a slot for the dummy return address in the wrapper + ccall case
header_bits = ptext SLIT("extern") <+> fun_proto <> semi
- fun_proto = cResType <+> pprCconv <+> ftext c_nm <>
+ fun_proto
+ | libffi
+ = ptext SLIT("void") <+> ftext c_nm <>
+ parens (ptext SLIT("void *cif STG_UNUSED, void* resp, void** args, void* the_stableptr"))
+ | otherwise
+ = cResType <+> pprCconv <+> ftext c_nm <>
parens (hsep (punctuate comma (map (\(nm,ty,_,_) -> ty <+> nm)
aug_arg_info)))
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 $$
fun_proto $$
vcat
[ lbrace
- , text "Capability *cap;"
+ , ptext SLIT("Capability *cap;")
, declareResult
, declareCResult
, text "cap = rts_lock();"
-- create the application + perform it.
- , text "cap=rts_evalIO" <> parens (
+ , ptext SLIT("cap=rts_evalIO") <> parens (
cap <>
- text "rts_apply" <> parens (
+ ptext SLIT("rts_apply") <> parens (
cap <>
text "(HaskellObj)"
- <> text (if is_IO_res_ty
- then "runIO_closure"
- else "runNonIO_closure")
+ <> ptext (if is_IO_res_ty
+ then SLIT("runIO_closure")
+ else SLIT("runNonIO_closure"))
<> comma
<> expr_to_run
) <+> comma
<> text "&ret"
) <> semi
- , text "rts_checkSchedStatus" <> parens (doubleQuotes (ftext c_nm)
+ , ptext SLIT("rts_checkSchedStatus") <> parens (doubleQuotes (ftext c_nm)
<> comma <> text "cap") <> semi
, assignCResult
- , text "rts_unlock(cap);"
+ , ptext SLIT("rts_unlock(cap);")
, if res_hty_is_unit then empty
- else text "return cret;"
+ else if libffi
+ then char '*' <> parens (cResType <> char '*') <>
+ ptext SLIT("resp = cret;")
+ else ptext SLIT("return cret;")
, rbrace
- ] $$
- initialiser
+ ]
+
+
+foreignExportInitialiser :: Id -> SDoc
+foreignExportInitialiser hs_fn =
+ -- 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)
+ 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)
+ ]
+
-- NB. the calculation here isn't strictly speaking correct.
-- We have a primitive Haskell type (eg. Int#, Double#), and
_other -> pprPanic "DsForeign.getPrimTyOf" (ppr ty)
where
rep_ty = repType ty
+
+-- represent a primitive type as a Char, for building a string that
+-- described the foreign function type. The types are size-dependent,
+-- e.g. 'W' is a signed 32-bit integer.
+primTyDescChar :: Type -> Char
+primTyDescChar ty
+ | ty `coreEqType` unitTy = 'v'
+ | otherwise
+ = case typePrimRep (getPrimTyOf ty) of
+ IntRep -> signed_word
+ WordRep -> unsigned_word
+ Int64Rep -> 'L'
+ Word64Rep -> 'l'
+ AddrRep -> unsigned_word
+ FloatRep -> 'f'
+ DoubleRep -> 'd'
+ _ -> pprPanic "primTyDescChar" (ppr ty)
+ where
+ (signed_word, unsigned_word)
+ | wORD_SIZE == 4 = ('W','w')
+ | wORD_SIZE == 8 = ('L','l')
+ | otherwise = panic "primTyDescChar"
\end{code}
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