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 SMRep
import MachOp
#endif
-import OccName
import Name
+import OccName
import TcType
-import ForeignCall
import DynFlags
import Outputable
import SrcLoc
import Bag
+import Unique
+import FastString
\end{code}
\begin{code}
tcFImport :: ForeignDecl Name -> TcM (Id, ForeignDecl Id)
tcFImport fo@(ForeignImport (L loc nm) hs_ty imp_decl)
- = addErrCtxt (foreignDeclCtxt fo) $
- tcHsSigType (ForSigCtxt nm) hs_ty `thenM` \ 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.
-- Use a LocalId to obey the invariant that locally-defined
-- things are LocalIds. However, it does not need zonking,
-- (so TcHsSyn.zonkForeignExports ignores it).
- in
- tcCheckFIType sig_ty arg_tys res_ty imp_decl `thenM` \ imp_decl' ->
+
+ 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
- returnM (id, ForeignImport (L loc id) undefined imp_decl')
+ return (id, ForeignImport (L loc id) undefined imp_decl')
\end{code}
------------ Checking types for foreign import ----------------------
\begin{code}
-tcCheckFIType _ arg_tys res_ty (DNImport spec)
- = checkCg checkDotnet `thenM_`
- getDOpts `thenM` \ dflags ->
- checkForeignArgs (isFFIDotnetTy dflags) arg_tys `thenM_`
- checkForeignRes True{-non IO ok-} (isFFIDotnetTy dflags) res_ty `thenM_`
- let (DNCallSpec isStatic kind _ _ _ _) = spec in
- (case kind of
+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 -> returnM ()
- _ -> returnM ()) `thenM_`
- returnM (DNImport (withDNTypes spec (map toDNType arg_tys) (toDNType res_ty)))
+ | otherwise -> return ()
+ _ -> return ()
+ return (DNImport (withDNTypes spec (map toDNType arg_tys) (toDNType res_ty)))
-tcCheckFIType sig_ty arg_tys res_ty idecl@(CImport _ _ _ _ (CLabel _))
- = checkCg checkCOrAsm `thenM_`
- check (isFFILabelTy sig_ty) (illegalForeignTyErr empty sig_ty) `thenM_`
+tcCheckFIType sig_ty arg_tys res_ty idecl@(CImport _ _ _ _ (CLabel _)) = do
+ checkCg checkCOrAsm
+ check (isFFILabelTy sig_ty) (illegalForeignTyErr empty sig_ty)
return idecl
-tcCheckFIType sig_ty arg_tys res_ty idecl@(CImport cconv _ _ _ CWrapper)
- = -- Foreign wrapper (former f.e.d.)
+tcCheckFIType sig_ty arg_tys res_ty idecl@(CImport cconv _ _ _ 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
-- as ft -> IO Addr is accepted, too. The use of the latter two forms
-- is DEPRECATED, though.
- checkCg checkCOrAsmOrInterp `thenM_`
- checkCConv cconv `thenM_`
- (case arg_tys of
- [arg1_ty] -> checkForeignArgs isFFIExternalTy arg1_tys `thenM_`
- checkForeignRes nonIOok isFFIExportResultTy res1_ty `thenM_`
- checkForeignRes mustBeIO isFFIDynResultTy res_ty `thenM_`
- checkFEDArgs arg1_tys
- where
- (arg1_tys, res1_ty) = tcSplitFunTys arg1_ty
- other -> addErrTc (illegalForeignTyErr empty sig_ty) ) `thenM_`
+ checkCg checkCOrAsmOrInterp
+ checkCConv cconv
+ case arg_tys of
+ [arg1_ty] -> do checkForeignArgs isFFIExternalTy arg1_tys
+ checkForeignRes nonIOok isFFIExportResultTy res1_ty
+ checkForeignRes mustBeIO isFFIDynResultTy res_ty
+ checkFEDArgs arg1_tys
+ where
+ (arg1_tys, res1_ty) = tcSplitFunTys arg1_ty
+ other -> addErrTc (illegalForeignTyErr empty sig_ty)
return idecl
tcCheckFIType sig_ty arg_tys res_ty idecl@(CImport cconv safety _ _ (CFunction target))
- | isDynamicTarget target -- Foreign import dynamic
- = checkCg checkCOrAsmOrInterp `thenM_`
- checkCConv cconv `thenM_`
- case arg_tys of -- The first arg must be Ptr, FunPtr, or Addr
- [] ->
- check False (illegalForeignTyErr empty sig_ty) `thenM_`
- return idecl
- (arg1_ty:arg_tys) ->
- getDOpts `thenM` \ dflags ->
- check (isFFIDynArgumentTy arg1_ty)
- (illegalForeignTyErr argument arg1_ty) `thenM_`
- checkForeignArgs (isFFIArgumentTy dflags safety) arg_tys `thenM_`
- checkForeignRes nonIOok (isFFIImportResultTy dflags) res_ty `thenM_`
- return idecl
- | otherwise -- Normal foreign import
- = checkCg (checkCOrAsmOrDotNetOrInterp) `thenM_`
- checkCConv cconv `thenM_`
- checkCTarget target `thenM_`
- getDOpts `thenM` \ dflags ->
- checkForeignArgs (isFFIArgumentTy dflags safety) arg_tys `thenM_`
- checkForeignRes nonIOok (isFFIImportResultTy dflags) res_ty `thenM_`
- return idecl
+ | isDynamicTarget target = do -- Foreign import dynamic
+ checkCg checkCOrAsmOrInterp
+ checkCConv cconv
+ case arg_tys of -- The first arg must be Ptr, FunPtr, or Addr
+ [] -> do
+ check False (illegalForeignTyErr empty sig_ty)
+ return idecl
+ (arg1_ty:arg_tys) -> do
+ dflags <- getDOpts
+ check (isFFIDynArgumentTy arg1_ty)
+ (illegalForeignTyErr argument arg1_ty)
+ checkForeignArgs (isFFIArgumentTy dflags safety) arg_tys
+ checkForeignRes nonIOok (isFFIImportResultTy dflags) res_ty
+ return idecl
+ | otherwise = do -- Normal foreign import
+ checkCg (checkCOrAsmOrDotNetOrInterp)
+ checkCConv cconv
+ checkCTarget target
+ dflags <- getDOpts
+ checkForeignArgs (isFFIArgumentTy dflags safety) arg_tys
+ checkForeignRes nonIOok (isFFIImportResultTy dflags) res_ty
+ return idecl
-- This makes a convenient place to check
-- that the C identifier is valid for C
-checkCTarget (StaticTarget str)
- = checkCg checkCOrAsmOrDotNetOrInterp `thenM_`
+checkCTarget (StaticTarget str) = do
+ checkCg checkCOrAsmOrDotNetOrInterp
check (isCLabelString str) (badCName str)
\end{code}
integral_args = sum [ (machRepByteWidth . 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")
+ err = ptext (sLit "On Alpha, I can only handle 32 bytes of non-floating-point arguments to foreign export dynamic")
#else
-checkFEDArgs arg_tys = returnM ()
+checkFEDArgs arg_tys = return ()
#endif
\end{code}
tcForeignExports decls
= foldlM combine (emptyLHsBinds, []) (filter isForeignExport decls)
where
- combine (binds, fs) fe =
- wrapLocSndM tcFExport fe `thenM` \ (b, f) ->
- returnM (b `consBag` binds, f:fs)
+ combine (binds, fs) fe = do
+ (b, f) <- wrapLocSndM tcFExport fe
+ return (b `consBag` binds, f:fs)
tcFExport :: ForeignDecl Name -> TcM (LHsBind Id, ForeignDecl Id)
tcFExport fo@(ForeignExport (L loc nm) hs_ty spec) =
- addErrCtxt (foreignDeclCtxt fo) $
+ addErrCtxt (foreignDeclCtxt fo) $ do
- tcHsSigType (ForSigCtxt nm) hs_ty `thenM` \ sig_ty ->
- tcPolyExpr (nlHsVar nm) sig_ty `thenM` \ rhs ->
+ sig_ty <- tcHsSigType (ForSigCtxt nm) hs_ty
+ rhs <- tcPolyExpr (nlHsVar nm) sig_ty
- tcCheckFEType sig_ty spec `thenM_`
+ tcCheckFEType sig_ty spec
-- we're exporting a function, but at a type possibly more
-- constrained than its declared/inferred type. Hence the need
-- to create a local binding which will call the exported function
-- at a particular type (and, maybe, overloading).
- newUnique `thenM` \ uniq ->
- getModule `thenM` \ mod ->
+ uniq <- newUnique
+ mod <- getModule
let
- gnm = mkExternalName uniq mod (mkForeignExportOcc (getOccName nm))
- (srcSpanStart loc)
+ -- 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)
- in
- returnM (bind, ForeignExport (L loc id) undefined spec)
+
+ return (bind, ForeignExport (L loc id) undefined spec)
\end{code}
------------ Checking argument types for foreign export ----------------------
\begin{code}
-tcCheckFEType sig_ty (CExport (CExportStatic str _))
- = check (isCLabelString str) (badCName str) `thenM_`
- checkForeignArgs isFFIExternalTy arg_tys `thenM_`
+tcCheckFEType sig_ty (CExport (CExportStatic str _)) = do
+ check (isCLabelString str) (badCName str)
+ checkForeignArgs isFFIExternalTy arg_tys
checkForeignRes nonIOok isFFIExportResultTy res_ty
where
-- Drop the foralls before inspecting n
------------ Checking argument types for foreign import ----------------------
checkForeignArgs :: (Type -> Bool) -> [Type] -> TcM ()
checkForeignArgs pred tys
- = mappM go tys `thenM_`
- returnM ()
+ = mapM_ go tys
where
go ty = check (pred ty) (illegalForeignTyErr argument ty)
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 (io, res_ty, _) <- tcSplitIOType_maybe ty,
pred_res_ty res_ty
- = returnM ()
+ = return ()
| otherwise
= check (non_io_result_ok && pred_res_ty ty)
checkCOrAsmOrDotNetOrInterp other
= Just (text "requires interpreted, C or native code generation")
-checkCg check
- = getDOpts `thenM` \ dflags ->
- let target = hscTarget dflags in
+checkCg check = do
+ dflags <- getDOpts
+ let target = hscTarget dflags
case target of
- HscNothing -> returnM ()
+ HscNothing -> return ()
otherwise ->
case check target of
- Nothing -> returnM ()
+ Nothing -> return ()
Just err -> addErrTc (text "Illegal foreign declaration:" <+> err)
\end{code}
\begin{code}
check :: Bool -> Message -> TcM ()
-check True _ = returnM ()
+check True _ = return ()
check _ the_err = addErrTc the_err
illegalForeignTyErr arg_or_res ty
- = hang (hsep [ptext SLIT("Unacceptable"), arg_or_res,
- ptext SLIT("type in foreign declaration:")])
+ = 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
badCName :: CLabelString -> Message
badCName target
- = sep [quotes (ppr target) <+> ptext SLIT("is not a valid C identifier")]
+ = sep [quotes (ppr target) <+> ptext (sLit "is not a valid C identifier")]
foreignDeclCtxt fo
- = hang (ptext SLIT("When checking declaration:"))
+ = hang (ptext (sLit "When checking declaration:"))
4 (ppr fo)
illegalDNMethodSig
- = ptext SLIT("'This pointer' expected as last argument")
+ = ptext (sLit "'This pointer' expected as last argument")
\end{code}