module checks to see if a foreign declaration has got a legal type.
\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 TcForeign
(
tcForeignImports
import TcRnMonad
import TcHsType
import TcExpr
+import TcEnv
import ForeignCall
import ErrUtils
#if alpha_TARGET_ARCH
import Type
import SMRep
-import MachOp
#endif
import Name
-import OccName
import TcType
import DynFlags
import Outputable
import SrcLoc
import Bag
-import Unique
import FastString
\end{code}
tcFImport :: ForeignDecl Name -> TcM (Id, ForeignDecl Id)
tcFImport fo@(ForeignImport (L loc nm) hs_ty imp_decl)
- = addErrCtxt (foreignDeclCtxt fo) $ do
- sig_ty <- tcHsSigType (ForSigCtxt nm) hs_ty
- let
- -- drop the foralls before inspecting the structure
- -- of the foreign type.
- (_, t_ty) = tcSplitForAllTys sig_ty
- (arg_tys, res_ty) = tcSplitFunTys t_ty
- id = mkLocalId nm sig_ty
+ = addErrCtxt (foreignDeclCtxt fo) $
+ do { sig_ty <- tcHsSigType (ForSigCtxt nm) hs_ty
+ ; let
+ -- Drop the foralls before inspecting the
+ -- structure of the foreign type.
+ (_, t_ty) = tcSplitForAllTys sig_ty
+ (arg_tys, res_ty) = tcSplitFunTys t_ty
+ id = mkLocalId nm sig_ty
-- Use a LocalId to obey the invariant that locally-defined
-- things are LocalIds. However, it does not need zonking,
-- (so TcHsSyn.zonkForeignExports ignores it).
- imp_decl' <- tcCheckFIType sig_ty arg_tys res_ty imp_decl
- -- can't use sig_ty here because it :: Type and we need HsType Id
- -- hence the undefined
- return (id, ForeignImport (L loc id) undefined imp_decl')
+ ; imp_decl' <- tcCheckFIType sig_ty arg_tys res_ty imp_decl
+ -- Can't use sig_ty here because sig_ty :: Type and
+ -- we need HsType Id hence the undefined
+ ; return (id, ForeignImport (L loc id) undefined imp_decl') }
+tcFImport d = pprPanic "tcFImport" (ppr d)
\end{code}
------------ Checking types for foreign import ----------------------
\begin{code}
-tcCheckFIType _ arg_tys res_ty (DNImport spec) = do
- checkCg checkDotnet
- dflags <- getDOpts
- checkForeignArgs (isFFIDotnetTy dflags) arg_tys
- checkForeignRes True{-non IO ok-} (isFFIDotnetTy dflags) res_ty
- let (DNCallSpec isStatic kind _ _ _ _) = spec
- case kind of
- DNMethod | not isStatic ->
- case arg_tys of
- [] -> addErrTc illegalDNMethodSig
- _
- | not (isFFIDotnetObjTy (last arg_tys)) -> addErrTc illegalDNMethodSig
- | otherwise -> return ()
- _ -> return ()
- return (DNImport (withDNTypes spec (map toDNType arg_tys) (toDNType res_ty)))
-
-tcCheckFIType sig_ty arg_tys res_ty idecl@(CImport _ _ _ _ (CLabel _)) = do
- checkCg checkCOrAsm
- check (isFFILabelTy sig_ty) (illegalForeignTyErr empty sig_ty)
- return idecl
+tcCheckFIType :: Type -> [Type] -> Type -> ForeignImport -> TcM ForeignImport
-tcCheckFIType sig_ty arg_tys res_ty idecl@(CImport cconv _ _ _ CWrapper) = do
+tcCheckFIType sig_ty arg_tys res_ty idecl@(CImport _ safety _ (CLabel _))
+ = ASSERT( null arg_tys )
+ do { checkCg checkCOrAsmOrInterp
+ ; checkSafety safety
+ ; check (isFFILabelTy res_ty) (illegalForeignTyErr empty sig_ty)
+ ; return idecl } -- NB check res_ty not sig_ty!
+ -- In case sig_ty is (forall a. ForeignPtr a)
+
+tcCheckFIType sig_ty arg_tys res_ty idecl@(CImport cconv safety _ CWrapper) = do
-- Foreign wrapper (former f.e.d.)
-- The type must be of the form ft -> IO (FunPtr ft), where ft is a
-- valid foreign type. For legacy reasons ft -> IO (Ptr ft) as well
-- is DEPRECATED, though.
checkCg checkCOrAsmOrInterp
checkCConv cconv
+ checkSafety safety
case arg_tys of
[arg1_ty] -> do checkForeignArgs isFFIExternalTy arg1_tys
checkForeignRes nonIOok isFFIExportResultTy res1_ty
checkFEDArgs arg1_tys
where
(arg1_tys, res1_ty) = tcSplitFunTys arg1_ty
- other -> addErrTc (illegalForeignTyErr empty sig_ty)
+ _ -> addErrTc (illegalForeignTyErr empty sig_ty)
return idecl
-tcCheckFIType sig_ty arg_tys res_ty idecl@(CImport cconv safety _ _ (CFunction target))
+tcCheckFIType sig_ty arg_tys res_ty idecl@(CImport cconv safety _ (CFunction target))
| isDynamicTarget target = do -- Foreign import dynamic
checkCg checkCOrAsmOrInterp
checkCConv cconv
+ checkSafety safety
case arg_tys of -- The first arg must be Ptr, FunPtr, or Addr
[] -> do
check False (illegalForeignTyErr empty sig_ty)
checkForeignArgs (isFFIArgumentTy dflags safety) arg_tys
checkForeignRes nonIOok (isFFIImportResultTy dflags) res_ty
return idecl
+ | cconv == PrimCallConv = do
+ dflags <- getDOpts
+ check (dopt Opt_GHCForeignImportPrim dflags)
+ (text "Use -XGHCForeignImportPrim to allow `foreign import prim'.")
+ checkCg (checkCOrAsmOrDotNetOrInterp)
+ checkCTarget target
+ check (playSafe safety)
+ (text "The safe/unsafe annotation should not be used with `foreign import prim'.")
+ checkForeignArgs (isFFIPrimArgumentTy dflags) arg_tys
+ -- prim import result is more liberal, allows (#,,#)
+ checkForeignRes nonIOok (isFFIPrimResultTy dflags) res_ty
+ return idecl
| otherwise = do -- Normal foreign import
checkCg (checkCOrAsmOrDotNetOrInterp)
checkCConv cconv
+ checkSafety safety
checkCTarget target
dflags <- getDOpts
checkForeignArgs (isFFIArgumentTy dflags safety) arg_tys
checkForeignRes nonIOok (isFFIImportResultTy dflags) res_ty
+ checkMissingAmpersand dflags arg_tys res_ty
return idecl
+
-- This makes a convenient place to check
-- that the C identifier is valid for C
-checkCTarget (StaticTarget str) = do
+checkCTarget :: CCallTarget -> TcM ()
+checkCTarget (StaticTarget str _) = do
checkCg checkCOrAsmOrDotNetOrInterp
check (isCLabelString str) (badCName str)
+
+checkCTarget DynamicTarget = panic "checkCTarget DynamicTarget"
+
+
+checkMissingAmpersand :: DynFlags -> [Type] -> Type -> TcM ()
+checkMissingAmpersand dflags arg_tys res_ty
+ | null arg_tys && isFunPtrTy res_ty &&
+ dopt Opt_WarnDodgyForeignImports dflags
+ = addWarn (ptext (sLit "possible missing & in foreign import of FunPtr"))
+ | otherwise
+ = return ()
\end{code}
On an Alpha, with foreign export dynamic, due to a giant hack when
\begin{code}
#include "nativeGen/NCG.h"
+
+checkFEDArgs :: [Type] -> TcM ()
#if alpha_TARGET_ARCH
checkFEDArgs arg_tys
= check (integral_args <= 32) err
where
- integral_args = sum [ (machRepByteWidth . argMachRep . primRepToCgRep) prim_rep
+ integral_args = sum [ (widthInBytes . argMachRep . primRepToCgRep) prim_rep
| prim_rep <- map typePrimRep arg_tys,
primRepHint prim_rep /= FloatHint ]
err = ptext (sLit "On Alpha, I can only handle 32 bytes of non-floating-point arguments to foreign export dynamic")
#else
-checkFEDArgs arg_tys = return ()
+checkFEDArgs _ = return ()
#endif
\end{code}
-- to create a local binding which will call the exported function
-- at a particular type (and, maybe, overloading).
- uniq <- newUnique
- mod <- getModule
- let
- -- We need to give a name to the new top-level binding that
- -- is *stable* (i.e. the compiler won't change it later),
- -- because this name will be referred to by the C code stub.
- -- Furthermore, the name must be unique (see #1533). If the
- -- same function is foreign-exported multiple times, the
- -- top-level bindings generated must not have the same name.
- -- Hence we create an External name (doesn't change), and we
- -- append a Unique to the string right here.
- uniq_str = showSDoc (pprUnique uniq)
- occ = mkVarOcc (occNameString (getOccName nm) ++ '_' : uniq_str)
- gnm = mkExternalName uniq mod (mkForeignExportOcc occ) loc
- id = mkExportedLocalId gnm sig_ty
- bind = L loc (VarBind id rhs)
-
- return (bind, ForeignExport (L loc id) undefined spec)
+
+ -- We need to give a name to the new top-level binding that
+ -- is *stable* (i.e. the compiler won't change it later),
+ -- because this name will be referred to by the C code stub.
+ id <- mkStableIdFromName nm sig_ty loc mkForeignExportOcc
+ return (mkVarBind id rhs, ForeignExport (L loc id) undefined spec)
+tcFExport d = pprPanic "tcFExport" (ppr d)
\end{code}
------------ Checking argument types for foreign export ----------------------
\begin{code}
-tcCheckFEType sig_ty (CExport (CExportStatic str _)) = do
+tcCheckFEType :: Type -> ForeignExport -> TcM ()
+tcCheckFEType sig_ty (CExport (CExportStatic str cconv)) = do
+ checkCg checkCOrAsm
check (isCLabelString str) (badCName str)
+ checkCConv cconv
checkForeignArgs isFFIExternalTy arg_tys
checkForeignRes nonIOok isFFIExportResultTy res_ty
where
--
checkForeignRes :: Bool -> (Type -> Bool) -> Type -> TcM ()
+nonIOok, mustBeIO :: Bool
nonIOok = True
mustBeIO = False
checkForeignRes non_io_result_ok pred_res_ty ty
-- (IO t) is ok, and so is any newtype wrapping thereof
- | Just (io, res_ty, _) <- tcSplitIOType_maybe ty,
+ | Just (_, res_ty, _) <- tcSplitIOType_maybe ty,
pred_res_ty res_ty
= return ()
\end{code}
\begin{code}
-#if defined(mingw32_TARGET_OS)
-checkDotnet HscC = Nothing
-checkDotnet _ = Just (text "requires C code generation (-fvia-C)")
-#else
-checkDotnet other = Just (text "requires .NET support (-filx or win32)")
-#endif
-
+checkCOrAsm :: HscTarget -> Maybe SDoc
checkCOrAsm HscC = Nothing
checkCOrAsm HscAsm = Nothing
-checkCOrAsm other
+checkCOrAsm _
= Just (text "requires via-C or native code generation (-fvia-C)")
+checkCOrAsmOrInterp :: HscTarget -> Maybe SDoc
checkCOrAsmOrInterp HscC = Nothing
checkCOrAsmOrInterp HscAsm = Nothing
checkCOrAsmOrInterp HscInterpreted = Nothing
-checkCOrAsmOrInterp other
+checkCOrAsmOrInterp _
= Just (text "requires interpreted, C or native code generation")
+checkCOrAsmOrDotNetOrInterp :: HscTarget -> Maybe SDoc
checkCOrAsmOrDotNetOrInterp HscC = Nothing
checkCOrAsmOrDotNetOrInterp HscAsm = Nothing
checkCOrAsmOrDotNetOrInterp HscInterpreted = Nothing
-checkCOrAsmOrDotNetOrInterp other
+checkCOrAsmOrDotNetOrInterp _
= Just (text "requires interpreted, C or native code generation")
+checkCg :: (HscTarget -> Maybe SDoc) -> TcM ()
checkCg check = do
dflags <- getDOpts
let target = hscTarget dflags
case target of
HscNothing -> return ()
- otherwise ->
+ _ ->
case check target of
Nothing -> return ()
Just err -> addErrTc (text "Illegal foreign declaration:" <+> err)
#if i386_TARGET_ARCH
checkCConv StdCallConv = return ()
#else
-checkCConv StdCallConv = addErrTc (text "calling convention not supported on this architecture: stdcall")
+checkCConv StdCallConv = addErrTc (text "calling convention not supported on this platform: stdcall")
#endif
+checkCConv PrimCallConv = addErrTc (text "The `prim' calling convention can only be used with `foreign import'")
+checkCConv CmmCallConv = panic "checkCConv CmmCallConv"
+\end{code}
+
+Deprecated "threadsafe" calls
+
+\begin{code}
+checkSafety :: Safety -> TcM ()
+checkSafety (PlaySafe True) = addWarn (text "The `threadsafe' foreign import style is deprecated. Use `safe' instead.")
+checkSafety _ = return ()
\end{code}
Warnings
check True _ = return ()
check _ the_err = addErrTc the_err
+illegalForeignTyErr :: SDoc -> Type -> SDoc
illegalForeignTyErr arg_or_res ty
= hang (hsep [ptext (sLit "Unacceptable"), arg_or_res,
ptext (sLit "type in foreign declaration:")])
4 (hsep [ppr ty])
-- Used for 'arg_or_res' argument to illegalForeignTyErr
+argument, result :: SDoc
argument = text "argument"
result = text "result"
badCName target
= sep [quotes (ppr target) <+> ptext (sLit "is not a valid C identifier")]
+foreignDeclCtxt :: ForeignDecl Name -> SDoc
foreignDeclCtxt fo
= hang (ptext (sLit "When checking declaration:"))
4 (ppr fo)
-
-illegalDNMethodSig
- = ptext (sLit "'This pointer' expected as last argument")
-
\end{code}