c2hs-0.28.2: src/C2HS/Gen/Bind.hs
{-# LANGUAGE CPP #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
-- C->Haskell Compiler: binding generator
--
-- Copyright (c) [1999..2003] Manuel M T Chakravarty
--
-- This file is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; either version 2 of the License, or
-- (at your option) any later version.
--
-- This file is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU General Public License for more details.
--
--- Description ---------------------------------------------------------------
--
-- Language: Haskell 98
--
-- Module implementing the expansion of the binding hooks.
--
-- * If there is an error in one binding hook, it is skipped and the next one
-- is processed (to collect as many errors as possible). However, if at
-- least one error occured, the expansion of binding hooks ends in a fatal
-- exception.
--
-- * `CST' exceptions are used to back off a binding hook as soon as an error
-- is encountered while it is processed.
--
-- Mapping of C types to Haskell FFI types:
-- ----------------------------------------
--
-- The following defines the mapping for basic types. If the type specifer
-- is missing, it is taken to be `int'. In the following, elements enclosed
-- in square brackets are optional.
--
-- void -> ()
-- char -> CChar
-- unsigned char -> CUChar
-- signed char -> CShort
-- signed -> CInt
-- [signed] int -> CInt
-- [signed] short [int] -> CSInt
-- [signed] long [int] -> CLong
-- [signed] long long [int] -> CLLong
-- unsigned [int] -> CUInt
-- unsigned short [int] -> CUShort
-- unsigned long [int] -> CULong
-- unsigned long long [int] -> CULLong
-- float -> CFloat
-- double -> CDouble
-- long double -> CLDouble
-- bool -> CBool
-- enum ... -> CInt
-- struct ... -> ** error **
-- union ... -> ** error **
--
-- Plain structures or unions (ie, if not the base type of a pointer type)
-- are not supported at the moment (the underlying FFI does not support them
-- directly). Named types (ie, in C type names defined using `typedef') are
-- traced back to their original definitions. Pointer types are mapped
-- to `Ptr a' or `FunPtr a' depending on whether they point to a functional.
-- Values obtained from bit fields are represented by `CInt' or `CUInt'
-- depending on whether they are signed.
--
-- We obtain the size and alignment constraints for all primitive types of C
-- from `CInfo', which obtains it from the Haskell 98 FFI. In the alignment
-- computations involving bit fields, we assume that the alignment
-- constraints for bitfields (wrt to non-bitfield members) is always the same
-- as for `int' irrespective of the size of the bitfield. This seems to be
-- implicitly guaranteed by K&R A8.3, but it is not entirely clear.
--
-- Identifier lookup:
-- ------------------
--
-- We allow to identify enumerations and structures by the names of `typedef'
-- types aliased to them.
--
-- * enumerations: It is first checked whether there is a tag with the given
-- identifier; if such a tag does not exist, the definition of a typedef
-- with the same name is taken if it exists.
-- * structs/unions: like enumerations
--
-- We generally use `shadow' lookups. When an identifier cannot be found,
-- we check whether - according to the prefix set by the context hook -
-- another identifier casts a shadow that matches. If so, that identifier is
-- taken instead of the original one.
--
--- ToDo ----------------------------------------------------------------------
--
-- * A function prototype that uses a defined type on its left hand side may
-- declare a function, while that is not obvious from the declaration
-- itself (without also considering the `typedef'). Calls to such
-- functions are currently rejected, which is a BUG.
--
-- * context hook must preceded all but the import hooks
--
-- * The use of `++' in the recursive definition of the routines generating
-- `Enum' instances is not particularly efficient.
--
-- * Some operands are missing in `applyBin' - unfortunately, Haskell does
-- not have standard bit operations. Some constructs are also missing
-- from `evalConstCExpr'. Haskell 98 FFI standardises `Bits'; use that.
--
module C2HS.Gen.Bind (expandHooks)
where
import Prelude hiding (exp, lookup)
import qualified Prelude
-- standard libraries
import Data.Char (toLower, isSpace)
import Data.Function (on)
import Data.IORef (IORef, newIORef, readIORef, writeIORef)
import System.IO.Unsafe (unsafePerformIO)
import System.IO (withFile, hPutStrLn, IOMode(..))
import System.Exit (ExitCode(..))
import System.Directory (removeFile)
import System.Process (readProcessWithExitCode, system)
import Data.List (deleteBy, groupBy, sortBy, intersperse, find, nubBy,
intercalate, isPrefixOf, isInfixOf, foldl')
import Data.Map (lookup)
import Data.Maybe (isNothing, isJust, fromJust, fromMaybe)
import Data.Bits ((.|.), (.&.))
import Control.Arrow (second)
import Control.Monad (when, unless, liftM, mapAndUnzipM, zipWithM, forM)
import Data.Ord (comparing)
import qualified Foreign.Storable as Storable (Storable(alignment),
Storable(sizeOf))
import Foreign (Ptr, FunPtr)
import Foreign.C
-- Language.C / compiler toolkit
import Language.C.Data.Position
import Language.C.Data.Ident
import Language.C.Pretty
import Text.PrettyPrint.HughesPJ (render)
import Data.Errors
import C2HS.Config (PlatformSpec(..))
import C2HS.State (getSwitch)
import C2HS.Switches (platformSB)
-- C->Haskell
import C2HS.State (CST, errorsPresent, showErrors, fatal,
SwitchBoard(..), Traces(..), putTraceStr)
import C2HS.C
-- friends
import C2HS.CHS (CHSModule(..), CHSFrag(..), CHSHook(..), CHSParm(..),
CHSMarsh, CHSArg(..), CHSAccess(..), CHSAPath(..),
CHSTypedefInfo, Direction(..), CHSPlusParmType(..),
CHSPtrType(..), showCHSParm, apathToIdent, apathRootIdent)
import C2HS.C.Info (CPrimType(..))
import C2HS.Gen.Monad (TransFun, transTabToTransFun, HsObject(..), GB,
GBState(..), Wrapper(..),
initialGBState, setContext, getPrefix, getReplacementPrefix,
delayCode, getDelayedCode, ptrMapsTo, queryPtr, objIs,
sizeIs, querySize, queryClass, queryPointer,
mergeMaps, dumpMaps, queryEnum, isEnum,
queryTypedef, isC2HSTypedef,
queryDefaultMarsh, isDefaultMarsh, addWrapper, getWrappers,
addHsDependency, getHsDependencies)
-- Module import alias.
imp :: String
imp = "C2HSImp"
impm :: String -> String
impm s = imp ++ "." ++ s
-- default marshallers
-- -------------------
-- FIXME:
-- - we might have a dynamically extended table in the monad if needed (we
-- could marshall enums this way and also save the 'id' marshallers for
-- pointers defined via (newtype) pointer hooks)
-- - the checks for the Haskell types are quite kludgy
stringIn :: String
stringIn = "\\s f -> " ++ impm "withCStringLen" ++ " s " ++
"(\\(p, n) -> f (p, fromIntegral n))"
-- | determine the default "in" marshaller for the given Haskell and C types
--
lookupDftMarshIn :: String -> [ExtType] -> GB CHSMarsh
lookupDftMarshIn "Bool" [PrimET pt] | isIntegralCPrimType pt = do
addHsDependency "Foreign.Marshal.Utils"
return $ Just (Left cFromBoolIde, CHSValArg)
lookupDftMarshIn hsTy [PrimET pt] | isIntegralHsType hsTy
&&isIntegralCPrimType pt =
return $ Just (Left cIntConvIde, CHSValArg)
lookupDftMarshIn hsTy [PrimET pt] | isFloatHsType hsTy
&&isFloatCPrimType pt =
return $ Just (Left cFloatConvIde, CHSValArg)
lookupDftMarshIn "Char" [PrimET CCharPT] = do
addHsDependency "Foreign.C.String"
return $ Just (Left castCharToCCharIde, CHSValArg)
lookupDftMarshIn "Char" [PrimET CUCharPT] = do
addHsDependency "Foreign.C.String"
return $ Just (Left castCharToCUCharIde, CHSValArg)
lookupDftMarshIn "Char" [PrimET CSCharPT] = do
addHsDependency "Foreign.C.String"
return $ Just (Left castCharToCSCharIde, CHSValArg)
lookupDftMarshIn "String" [PtrET (PrimET CCharPT)] = do
addHsDependency "Foreign.C.String"
return $ Just (Left withCStringIde, CHSIOArg)
lookupDftMarshIn "CString" [PtrET (PrimET CCharPT)] =
return $ Just (Right "flip ($)", CHSIOArg)
lookupDftMarshIn "String" [PtrET (PrimET CCharPT), PrimET pt]
| isIntegralCPrimType pt = do
addHsDependency "Foreign.C.String"
return $ Just (Right stringIn , CHSIOArg)
lookupDftMarshIn hsTy [PtrET (PrimET pt)]
| isIntegralHsType hsTy && isIntegralCPrimType pt = do
addHsDependency "Foreign.Marshal.Utils"
return $ Just (Right $ impm "with" ++ " . fromIntegral", CHSIOArg)
lookupDftMarshIn hsTy [PtrET (PrimET pt)]
| isFloatHsType hsTy && isFloatCPrimType pt = do
addHsDependency "Foreign.Marshal.Utils"
return $ Just (Right $ impm "with" ++ " . realToFrac", CHSIOArg)
lookupDftMarshIn "Bool" [PtrET (PrimET pt)]
| isIntegralCPrimType pt = do
addHsDependency "Foreign.Marshal.Utils"
return $ Just (Right $ impm "with" ++ " . fromBool", CHSIOArg)
lookupDftMarshIn hsTy [PtrET UnitET] | "Ptr " `isPrefixOf` hsTy =
return $ Just (Left idIde, CHSValArg)
lookupDftMarshIn hsTy [PrimET (CAliasedPT tds hsAlias _)] = do
mm <- queryDefaultMarsh $ (In, tds, False)
case mm of
Nothing -> if hsTy == hsAlias
then return $ Just (Left idIde, CHSValArg)
else return Nothing
Just m -> return $ Just m
lookupDftMarshIn hsTy [PtrET (PrimET (CAliasedPT tds hsAlias _pt))] = do
mm <- queryDefaultMarsh $ (In, tds, True)
case mm of
Nothing -> if hsTy == hsAlias
then return $ Just (Left idIde, CHSValArg)
else return Nothing
Just m -> return $ Just m
-- Default case deals with:
lookupDftMarshIn hsty _ = do
om <- readCT objmap
isenum <- queryEnum hsty
case (isenum, (internalIdent hsty) `lookup` om) of
-- 1. enumeration hooks
(True, Nothing) ->
return $ Just (Right "fromIntegral . fromEnum", CHSValArg)
-- 2. naked and newtype pointer hooks
(False, Just (Pointer CHSPtr _)) ->
return $ Just (Left idIde, CHSValArg)
-- 3. foreign pointer hooks
(False, Just (Pointer (CHSForeignPtr _) False)) -> do
addHsDependency "Foreign.ForeignPtr"
return $ Just (Left withForeignPtrIde, CHSIOArg)
-- 4. foreign newtype pointer hooks
(False, Just (Pointer (CHSForeignPtr _) True)) ->
return $ Just (Right $ "with" ++ hsty, CHSIOArg)
_ -> return Nothing
-- FIXME: handle array-list conversion
-- | determine the default "out" marshaller for the given Haskell and C types
--
lookupDftMarshOut :: String -> [ExtType] -> GB CHSMarsh
lookupDftMarshOut "()" _ =
return $ Just (Left voidIde, CHSVoidArg)
lookupDftMarshOut hsTy [IOET cTy] = lookupDftMarshOut hsTy [cTy]
lookupDftMarshOut "Bool" [PrimET pt] | isIntegralCPrimType pt = do
addHsDependency "Foreign.Marshal.Utils"
return $ Just (Left cToBoolIde, CHSValArg)
lookupDftMarshOut hsTy [PrimET pt] | isIntegralHsType hsTy
&& isIntegralCPrimType pt =
return $ Just (Left cIntConvIde, CHSValArg)
lookupDftMarshOut hsTy [PrimET pt] | isFloatHsType hsTy
&& isFloatCPrimType pt =
return $ Just (Left cFloatConvIde, CHSValArg)
lookupDftMarshOut "Char" [PrimET CCharPT] = do
addHsDependency "Foreign.C.String"
return $ Just (Left castCCharToCharIde, CHSValArg)
lookupDftMarshOut "Char" [PrimET CUCharPT] = do
addHsDependency "Foreign.C.String"
return $ Just (Left castCUCharToCharIde, CHSValArg)
lookupDftMarshOut "Char" [PrimET CSCharPT] = do
addHsDependency "Foreign.C.String"
return $ Just (Left castCSCharToCharIde, CHSValArg)
lookupDftMarshOut "String" [PtrET (PrimET CCharPT)] = do
addHsDependency "Foreign.C.String"
return $ Just (Left peekCStringIde, CHSIOArg)
lookupDftMarshOut "CString" [PtrET (PrimET CCharPT)] =
return $ Just (Left returnIde, CHSIOArg)
lookupDftMarshOut "String" [PtrET (PrimET CCharPT), PrimET pt]
| isIntegralCPrimType pt = do
addHsDependency "Foreign.C.String"
return $ Just (Right $ "\\(s, n) -> " ++ impm "peekCStringLen" ++
" (s, fromIntegral n)",
CHSIOArg)
lookupDftMarshOut hsTy [PtrET UnitET] | "Ptr " `isPrefixOf` hsTy =
return $ Just (Left idIde, CHSValArg)
lookupDftMarshOut hsTy [PrimET (CAliasedPT tds hsAlias _)] = do
mm <- queryDefaultMarsh $ (Out, tds, False)
case mm of
Nothing -> if hsTy == hsAlias
then return $ Just (Left idIde, CHSValArg)
else return Nothing
Just m -> return $ Just m
lookupDftMarshOut hsTy [PtrET (PrimET (CAliasedPT tds hsAlias _pt))] = do
mm <- queryDefaultMarsh $ (Out, tds, True)
case mm of
Nothing -> if hsTy == hsAlias
then return $ Just (Left idIde, CHSValArg)
else return Nothing
Just m -> return $ Just m
lookupDftMarshOut hsty _ = do
om <- readCT objmap
isenum <- queryEnum hsty
res <- case (isenum, (internalIdent hsty) `lookup` om) of
-- 1. enumeration hooks
(True, Nothing) -> return $ Just (Right "toEnum . fromIntegral", CHSValArg)
-- 2. naked and newtype pointer hooks
(False, Just (Pointer CHSPtr _)) -> return $ Just (Left idIde, CHSValArg)
-- 3. foreign pointer hooks
(False, Just (Pointer (CHSForeignPtr Nothing) False)) -> do
addHsDependency "Foreign.ForeignPtr"
return $ Just (Left newForeignPtr_Ide, CHSIOArg)
(False, Just (Pointer (CHSForeignPtr (Just fin)) False)) -> do
code <- newForeignPtrCode fin
return $ Just (Right $ code, CHSIOArg)
-- 4. foreign newtype pointer hooks
(False, Just (Pointer (CHSForeignPtr Nothing) True)) -> do
addHsDependency "Foreign.ForeignPtr"
return $ Just (Right $ "\\x -> " ++ impm "newForeignPtr_ x >>= " ++
" (return . " ++ hsty ++ ")",
CHSIOArg)
(False, Just (Pointer (CHSForeignPtr (Just fin)) True)) -> do
code <- newForeignPtrCode fin
return $ Just (Right $ "\\x -> " ++ code ++ " x >>= (return . " ++
hsty ++ ")", CHSIOArg)
_ -> return Nothing
return res
-- FIXME: add combination, such as "peek" plus "cIntConv" etc
-- FIXME: handle array-list conversion
newForeignPtrCode :: (Ident, Maybe Ident) -> GB String
newForeignPtrCode (cide, ohside) = do
(_, cide') <- findFunObj cide True
let fin = (identToString cide') `maybe` identToString $ ohside
addHsDependency "Foreign.ForeignPtr"
return $ impm "newForeignPtr" ++ " " ++ fin
-- | check for integral Haskell types
--
isIntegralHsType :: String -> Bool
isIntegralHsType "Int" = True
isIntegralHsType "Int8" = True
isIntegralHsType "Int16" = True
isIntegralHsType "Int32" = True
isIntegralHsType "Int64" = True
isIntegralHsType "Word8" = True
isIntegralHsType "Word16" = True
isIntegralHsType "Word32" = True
isIntegralHsType "Word64" = True
isIntegralHsType "CShort" = True
isIntegralHsType "CUShort" = True
isIntegralHsType "CInt" = True
isIntegralHsType "CUInt" = True
isIntegralHsType "CLong" = True
isIntegralHsType "CULong" = True
isIntegralHsType _ = False
-- | check for floating Haskell types
--
isFloatHsType :: String -> Bool
isFloatHsType "Float" = True
isFloatHsType "Double" = True
isFloatHsType "CFloat" = True
isFloatHsType "CDouble" = True
isFloatHsType _ = False
isVariadic :: ExtType -> Bool
isVariadic (FunET s t) = any isVariadic [s,t]
isVariadic (IOET t) = isVariadic t
isVariadic (PtrET t) = isVariadic t
isVariadic (VarFunET _) = True
isVariadic _ = False
-- | check for integral C types
--
-- * For marshalling purposes C char's are integral types (see also types
-- classes for which the FFI guarantees instances for 'CChar', 'CSChar', and
-- 'CUChar')
--
isIntegralCPrimType :: CPrimType -> Bool
isIntegralCPrimType = (`elem` [CCharPT, CSCharPT, CIntPT, CShortPT, CLongPT,
CLLongPT, CUIntPT, CUCharPT, CUShortPT,
CULongPT, CULLongPT, CBoolPT])
-- | check for floating C types
--
isFloatCPrimType :: CPrimType -> Bool
isFloatCPrimType = (`elem` [CFloatPT, CDoublePT, CLDoublePT])
-- | standard conversions
--
voidIde, cFromBoolIde, cToBoolIde, cIntConvIde, cFloatConvIde,
withCStringIde, peekCStringIde, idIde,
newForeignPtr_Ide, withForeignPtrIde, returnIde,
castCharToCCharIde, castCharToCUCharIde, castCharToCSCharIde,
castCCharToCharIde, castCUCharToCharIde, castCSCharToCharIde :: Ident
voidIde = internalIdent $ impm "void" -- never appears in the output
cFromBoolIde = internalIdent $ impm "fromBool"
cToBoolIde = internalIdent $ impm "toBool"
cIntConvIde = internalIdent "fromIntegral"
cFloatConvIde = internalIdent "realToFrac"
withCStringIde = internalIdent $ impm "withCString"
peekCStringIde = internalIdent $ impm "peekCString"
idIde = internalIdent "id"
newForeignPtr_Ide = internalIdent $ impm "newForeignPtr_"
withForeignPtrIde = internalIdent $ impm "withForeignPtr"
returnIde = internalIdent "return"
castCharToCCharIde = internalIdent $ impm "castCharToCChar"
castCharToCUCharIde = internalIdent $ impm "castCharToCUChar"
castCharToCSCharIde = internalIdent $ impm "castCharToCSChar"
castCCharToCharIde = internalIdent $ impm "castCCharToChar"
castCUCharToCharIde = internalIdent $ impm "castCUCharToChar"
castCSCharToCharIde = internalIdent $ impm "castCSCharToChar"
-- expansion of binding hooks
-- --------------------------
-- | given a C header file and a binding file, expand all hooks in the binding
-- file using the C header information
--
-- * together with the module, returns the contents of the .chi file
--
-- * if any error (not warnings) is encountered, a fatal error is raised.
--
-- * also returns all warning messages encountered (last component of result)
--
expandHooks :: AttrC -> CHSModule ->
CST s (CHSModule, String, [Wrapper], String)
expandHooks ac mod' = do
(_, res) <- runCT (expandModule mod') ac initialGBState
return res
expandModule :: CHSModule -> GB (CHSModule, String, [Wrapper], String)
expandModule (CHSModule mfrags) =
do
-- expand hooks
--
traceInfoExpand
frags' <- expandFrags mfrags
hsdeps <- getHsDependencies
let frags'' = addImports frags' hsdeps
delayedFrags <- getDelayedCode
-- get .chi dump
--
chi <- dumpMaps
-- check for errors and finalise
--
errs <- errorsPresent
if errs
then do
traceInfoErr
errmsgs <- showErrors
fatal ("Errors during expansion of binding hooks:\n\n" -- fatal error
++ errmsgs)
else do
traceInfoOK
warnmsgs <- showErrors
wraps <- getWrappers
return (CHSModule (frags'' ++ delayedFrags), chi, wraps, warnmsgs)
where
traceInfoExpand = putTraceStr tracePhasesSW
("...expanding binding hooks...\n")
traceInfoErr = putTraceStr tracePhasesSW
("...error(s) detected.\n")
traceInfoOK = putTraceStr tracePhasesSW
("...successfully completed.\n")
-- | add import declarations for modules required internally by C2HS
--
addImports :: [CHSFrag] -> [String] -> [CHSFrag]
addImports fs imps = before ++ impfrags ++ after
where impfrags = sp ++ concatMap impfrag imps ++ sp
sp = [CHSVerb "\n" imppos]
impfrag i =
[CHSVerb ("import qualified " ++ i ++ " as " ++ imp) imppos,
CHSVerb "\n" imppos]
(before, after) = doSplit 0 Nothing False [] fs
imppos = posOf $ last before
-- Find the appropriate location to put the import
-- declarations. This relies heavily on the details of the
-- CHS parser to deal with Haskell comments, but a simple
-- approach like this seems to be a better idea than using
-- haskell-src-exts or something like that, mostly because
-- none of the Haskell parsing packages deal with *all* GHC
-- extensions. The approach taken here isn't pretty, but it
-- seems to work.
doSplit :: Int -> Maybe Int -> Bool ->
[CHSFrag] -> [CHSFrag] -> ([CHSFrag], [CHSFrag])
doSplit _ Nothing _ _ [] = (fs, [])
doSplit _ (Just ln) _ _ [] = splitAt (ln-1) fs
doSplit 0 mln wh acc (f@(CHSVerb s pos) : fs')
| "--" `isPrefixOf` s = doSplit 0 mln wh (f:acc) fs'
| s == "{-" = doSplit 1 mln wh (f:acc) fs'
| wh && "where" `isInfixOf` s = (reverse (f:acc), fs')
| "module" `isPrefixOf` (dropWhile isSpace s) =
if (" where" `isInfixOf` s || ")where" `isInfixOf` s)
then (reverse (f:acc), fs')
else doSplit 0 mln True (f:acc) fs'
| otherwise = if null (dropWhile isSpace s) || isJust mln
then doSplit 0 mln wh (f:acc) fs'
else doSplit 0 mln' wh (f:acc) fs'
where mln' | isSourcePos pos = Just $ posRow pos
| otherwise = Nothing
doSplit cdep mln wh acc (f@(CHSVerb s _) : fs')
| s == "-}" = doSplit (cdep-1) mln wh (f:acc) fs'
| s == "{-" = doSplit (cdep+1) mln wh (f:acc) fs'
| otherwise = doSplit cdep mln wh (f:acc) fs'
doSplit cdep mln wh acc (f:fs') = doSplit cdep mln wh (f:acc) fs'
expandFrags :: [CHSFrag] -> GB [CHSFrag]
expandFrags = liftM concat . mapM expandFrag
expandFrag :: CHSFrag -> GB [CHSFrag]
expandFrag verb@(CHSVerb _ _ ) = return [verb]
expandFrag line@(CHSLine _ ) = return [line]
expandFrag (CHSHook h pos) =
do
code <- expandHook h pos
return [CHSVerb code builtinPos]
`ifCTExc` return [CHSVerb "** ERROR **" builtinPos]
expandFrag (CHSCPP s _ _) =
interr $ "GenBind.expandFrag: Left over CHSCPP!\n---\n" ++ s ++ "\n---"
expandFrag (CHSC s _ ) =
interr $ "GenBind.expandFrag: Left over CHSC!\n---\n" ++ s ++ "\n---"
expandFrag (CHSCond alts dft) =
do
traceInfoCond
select alts
where
select [] = do
traceInfoDft dft
expandFrags (maybe [] id dft)
select ((ide, cfrags):alts') = do
oobj <- findTag ide
traceInfoVal ide oobj
if isNothing oobj
then
select alts'
else -- found right alternative
expandFrags cfrags
--
traceInfoCond = traceGenBind "** CPP conditional:\n"
traceInfoVal ide oobj = traceGenBind $ identToString ide ++ " is " ++
(if isNothing oobj then "not " else "") ++
"defined.\n"
traceInfoDft dft' = if isNothing dft'
then
return ()
else
traceGenBind "Choosing else branch.\n"
expandHook :: CHSHook -> Position -> GB String
expandHook (CHSImport qual ide chi _) _ =
do
mergeMaps chi
return $
"import " ++ (if qual then "qualified " else "") ++ identToString ide
expandHook (CHSContext olib oprefix orepprefix _) _ =
do
setContext olib oprefix orepprefix -- enter context information
-- use the prefix on name spaces
when (isJust oprefix) $
applyPrefixToNameSpaces (fromJust oprefix) (maybe "" id orepprefix)
return ""
expandHook (CHSNonGNU _) _ = return ""
expandHook (CHSType ide pos) _ =
do
traceInfoType
decl <- findAndChaseDecl ide False True -- no indirection, but shadows
ty <- extractSimpleType False pos decl
traceInfoDump (render $ pretty decl) ty
when (isVariadic ty) (variadicErr pos (posOf decl))
addExtTypeDependency ty
return $ "(" ++ showExtType ty ++ ")"
where
traceInfoType = traceGenBind "** Type hook:\n"
traceInfoDump decl ty = traceGenBind $
"Declaration\n" ++ show decl ++ "\ntranslates to\n"
++ showExtType ty ++ "\n"
expandHook (CHSAlignof ide _) _ =
do
traceInfoAlignof
decl <- findAndChaseDeclOrTag ide False True -- no indirection, but shadows
checkForIncomplete decl
(_, align) <- sizeAlignOf decl
traceInfoDump (render $ pretty decl) align
return $ show align
where
traceInfoAlignof = traceGenBind "** alignment hook:\n"
traceInfoDump decl align = traceGenBind $
"Alignment of declaration\n" ++ show decl ++ "\nis "
++ show align ++ "\n"
expandHook (CHSSizeof ide _) _ =
do
traceInfoSizeof
decl <- findAndChaseDeclOrTag ide False True -- no indirection, but shadows
checkForIncomplete decl
(sz, _) <- sizeAlignOf decl
traceInfoDump (render $ pretty decl) sz
return $ show (padBits sz)
where
traceInfoSizeof = traceGenBind "** Sizeof hook:\n"
traceInfoDump decl sz = traceGenBind $
"Size of declaration\n" ++ show decl ++ "\nis "
++ show (padBits sz) ++ "\n"
expandHook (CHSEnumDefine _ _ _ _) _ =
interr $ "Binding generation error : enum define hooks " ++
"should be eliminated via preprocessing "
expandHook (CHSEnum cide oalias chsTrans emit oprefix orepprefix derive pos) _ =
do
-- get the corresponding C declaration
--
enum <- lookupEnum cide True -- smart lookup incl error handling
--
-- convert the translation table and generate data type definition code
--
gprefix <- getPrefix
let pfx = case oprefix of
Nothing -> gprefix
Just pref -> pref
grepprefix <- getReplacementPrefix
let reppfx = case orepprefix of
Nothing -> grepprefix
Just pref -> pref
let trans = transTabToTransFun pfx reppfx chsTrans
hide = identToString . fromMaybe cide $ oalias
enumDef enum hide trans emit (map identToString derive) pos
expandHook hook@(CHSCall isPure isUns (CHSRoot _ ide) oalias pos) _ =
do
traceEnter
-- get the corresponding C declaration; raises error if not found or not a
-- function; we use shadow identifiers, so the returned identifier is used
-- afterwards instead of the original one
--
(ObjCO cdecl, ide') <- findFunObj ide True
let ideLexeme = identToString ide' -- orignl name might have been a shadow
hsLexeme = ideLexeme `maybe` identToString $ oalias
cdecl' = ide' `simplifyDecl` cdecl
ty <- extractFunType pos cdecl' Nothing
let args = concat [ " x" ++ show n | n <- [1..numArgs ty] ]
callImport hook isUns [] ideLexeme hsLexeme cdecl' Nothing pos
when isPure $ addHsDependency "System.IO.Unsafe"
case (isPure, length args) of
(False, _) -> return hsLexeme
(True, 0) -> return $ "(" ++ impm "unsafePerformIO" ++
" " ++ hsLexeme ++ ")"
(True, _) -> return $ "(\\" ++ args ++ " -> " ++
impm "unsafePerformIO" ++ " (" ++
hsLexeme ++ args ++ "))"
where
traceEnter = traceGenBind $
"** Call hook for `" ++ identToString ide ++ "':\n"
expandHook hook@(CHSCall isPure isUns apath oalias pos) _ =
do
traceEnter
(decl, offsets) <- accessPath apath
ptrTy <- extractSimpleType False pos decl
ty <- case ptrTy of
PtrET f@(FunET _ _) -> return f
_ -> funPtrExpectedErr pos
traceValueType ty
set_get <- setGet pos CHSGet offsets Nothing ptrTy Nothing
-- get the corresponding C declaration; raises error if not found or not a
-- function; we use shadow identifiers, so the returned identifier is used
-- afterwards instead of the original one
--
-- (ObjCO cdecl, ide) <- findFunObj ide True
let ideLexeme = identToString $ apathToIdent apath
hsLexeme = ideLexeme `maybe` identToString $ oalias
-- cdecl' = ide `simplifyDecl` cdecl
args = concat [ " x" ++ show n | n <- [1..numArgs ty] ]
callImportDyn hook isUns ideLexeme hsLexeme decl ty pos
let res = "(\\o" ++ args ++ " -> " ++ set_get ++ " o >>= \\f -> "
++ hsLexeme ++ " f" ++ args ++ ")"
if isPure
then do
addHsDependency "System.IO.Unsafe"
return $ "(" ++ impm "unsafePerformIO" ++ " " ++ res ++ ")"
else return res
where
traceEnter = traceGenBind $
"** Indirect call hook for `" ++
identToString (apathToIdent apath) ++ "':\n"
traceValueType et = traceGenBind $
"Type of accessed value: " ++ showExtType et ++ "\n"
expandHook (CHSFun isPure isUns _ inVarTypes (CHSRoot _ ide)
oalias ctxt parms parm pos) hkpos =
do
traceEnter
traceGenBind $ "ide = '" ++ show ide ++ "'\n"
traceGenBind $ "inVarTypes = " ++ show inVarTypes ++ "\n"
-- get the corresponding C declaration; raises error if not found or not a
-- function; we use shadow identifiers, so the returned identifier is used
-- afterwards instead of the original one
--
(ObjCO cdecl, cide) <- findFunObj ide True
let ideLexeme = identToString ide -- orignal name might have been a shadow
hsLexeme = ideLexeme `maybe` identToString $ oalias
fiLexeme = hsLexeme ++ "'_" -- Urgh - probably unqiue...
fiIde = internalIdent fiLexeme
cdecl' = cide `simplifyDecl` cdecl
callHook = CHSCall isPure isUns (CHSRoot False cide) (Just fiIde) pos
isWrapped (CHSParm _ _ twovals _ w _ _)
| twovals = [w, w]
| otherwise = [w]
isWrapped _ = [False]
wrapped = Just $ concatMap isWrapped parms
varTypes <- convertVarTypes hsLexeme pos inVarTypes
callImport callHook isUns varTypes (identToString cide)
fiLexeme cdecl' wrapped pos
extTy <- extractFunType pos cdecl' wrapped
funDef isPure hsLexeme fiLexeme extTy varTypes
ctxt parms parm Nothing pos hkpos
where
traceEnter = traceGenBind $
"** Fun hook for `" ++ identToString ide ++ "':\n"
expandHook (CHSFun isPure isUns _ _ apath oalias ctxt parms parm pos) hkpos =
do
traceEnter
(decl, offsets) <- accessPath apath
ptrTy <- extractSimpleType False pos decl
ty <- case ptrTy of
PtrET f@(FunET _ _) -> return f
_ -> funPtrExpectedErr pos
traceValueType ty
-- get the corresponding C declaration; raises error if not found or not a
-- function; we use shadow identifiers, so the returned identifier is used
-- afterwards instead of the original one
--
-- (ObjCO cdecl, cide) <- findFunObj ide True
let ideLexeme = identToString $ apathToIdent apath
hsLexeme = ideLexeme `maybe` identToString $ oalias
fiLexeme = hsLexeme ++ "'_" -- Urgh - probably unqiue...
fiIde = internalIdent fiLexeme
-- cdecl' = cide `simplifyDecl` cdecl
-- args = concat [ " x" ++ show n | n <- [1..numArgs ty] ]
callHook = CHSCall isPure isUns apath (Just fiIde) pos
callImportDyn callHook isUns ideLexeme fiLexeme decl ty pos
set_get <- setGet pos CHSGet offsets Nothing ptrTy Nothing
funDef isPure hsLexeme fiLexeme (FunET ptrTy $ purify ty) []
ctxt parms parm (Just set_get) pos hkpos
where
-- remove IO from the result type of a function ExtType. necessary
-- due to an unexpected interaction with the way funDef works
purify (FunET a b) = FunET a (purify b)
purify (IOET b) = b
purify a = a
traceEnter = traceGenBind $
"** Fun hook for `" ++ identToString (apathToIdent apath) ++ "':\n"
traceValueType et = traceGenBind $
"Type of accessed value: " ++ showExtType et ++ "\n"
expandHook (CHSField access path pos) _ =
do
traceInfoField
traceGenBind $ "path = " ++ show path ++ "\n"
onewtype <- apathNewtypeName path
traceGenBind $ "onewtype = " ++ show onewtype ++ "\n"
(decl, offsets) <- accessPath path
traceDepth offsets
ty <- extractSimpleType False pos decl
traceValueType ty
setGet pos access offsets (isArrDecl decl) ty onewtype
where
accessString = case access of
CHSGet -> "Get"
CHSSet -> "Set"
traceInfoField = traceGenBind $ "** " ++ accessString ++ " hook:\n"
traceDepth offsets = traceGenBind $ "Depth of access path: "
++ show (length offsets) ++ "\n"
traceValueType et = traceGenBind $
"Type of accessed value: " ++ showExtType et ++ "\n"
expandHook (CHSOffsetof path pos) _ =
do
traceGenBind $ "** offsetof hook:\n"
(decl, offsets) <- accessPath path
traceGenBind $ "Depth of access path: " ++ show (length offsets) ++ "\n"
checkType decl offsets >>= \ offset -> return $ "(" ++ show offset ++ ")"
where
checkType decl [BitSize offset _] =
extractCompType True True False decl >>= \ compTy ->
case compTy of
(VarFunET _) -> variadicErr pos pos
(IOET _) ->
interr "GenBind.expandHook(CHSOffsetOf): Illegal type!"
(UnitET ) -> voidFieldErr pos
(DefinedET _ _) -> return offset
(PrimET (CUFieldPT _)) -> offsetBitfieldErr pos
(PrimET (CSFieldPT _)) -> offsetBitfieldErr pos
_ -> return offset
checkType _ _ = offsetDerefErr pos
expandHook hook@(CHSPointer isStar cName oalias ptrKind isNewtype oRefType emit
pos) _ =
do
traceInfoPointer
let hsIde = fromMaybe cName oalias
hsName = identToString hsIde
hsIde `objIs` Pointer ptrKind isNewtype -- register Haskell object
decl <- findAndChaseDeclOrTag cName False True
(sz, _) <- sizeAlignOfPtr decl
hsIde `sizeIs` (padBits sz)
--
-- we check for a typedef declaration or tag (struct, union, or enum)
--
declOrTag <- lookupDeclOrTag cName True
case declOrTag of
Left cdecl -> do -- found a typedef declaration
cNameFull <- case declaredName cdecl of
Just ide -> return ide
Nothing -> interr
"GenBind.expandHook: Where is the name?"
cNameFull `refersToNewDef` ObjCD (TypeCO cdecl)
-- assoc needed for chasing
traceInfoCName "declaration" cNameFull
unless (isStar || isPtrDecl cdecl) $
ptrExpectedErr (posOf cName)
(hsType, isFun) <-
case oRefType of
[] -> do
cDecl <- chaseDecl cNameFull (not isStar)
et <- extractPtrType cDecl
traceInfoPtrType et
let et' = adjustPtr isStar et
when (isVariadic et')
(variadicErr pos (posOf cDecl))
addExtTypeDependency et'
return (showExtType et', isFunExtType et')
hsType -> return (identsToString hsType, False)
-- FIXME: it is not possible to determine whether `hsType'
-- is a function; we would need to extend the syntax to
-- allow `... -> fun HSTYPE' to explicitly mark function
-- types if this ever becomes important
traceInfoHsType hsName hsType
doFinalizer hook ptrKind (if isNewtype then hsName else "()")
pointerDef isStar cNameFull hsName ptrKind isNewtype hsType isFun emit
Right tag -> do -- found a tag definition
let cNameFull = tagName tag
traceInfoCName "tag definition" cNameFull
unless isStar $ -- tags need an explicit `*'
ptrExpectedErr (posOf cName)
let hsType = case oRefType of
[] -> "()"
hsType' -> identsToString hsType'
traceInfoHsType hsName hsType
doFinalizer hook ptrKind (if isNewtype then hsName else "()")
pointerDef isStar cNameFull hsName ptrKind isNewtype hsType False emit
where
-- remove a pointer level if the first argument is `False'
--
adjustPtr True et = et
adjustPtr False (PtrET et) = et
adjustPtr False (DefinedET _ _) =
interr "GenBind.adjustPtr: Can't adjust defined type"
adjustPtr _ _ =
interr "GenBind.adjustPtr: Where is the Ptr?"
--
traceInfoPointer = traceGenBind "** Pointer hook:\n"
traceInfoPtrType et = traceGenBind $
"extracted ptr type is `" ++ showExtType et ++ "'\n"
traceInfoHsType name ty = traceGenBind $
"associated with Haskell entity `" ++ name ++ "'\nhaving type " ++ ty
++ "\n"
traceInfoCName kind ide = traceGenBind $
"found C " ++ kind ++ " for `" ++ identToString ide ++ "'\n"
identsToString :: [Ident] -> String
identsToString = intercalate " " . map identToString
expandHook (CHSClass oclassIde classIde typeIde pos) _ =
do
traceInfoClass
classIde `objIs` Class (fmap identToString oclassIde)
(identToString typeIde) -- register Haskell object
superClasses <- collectClasses oclassIde
Pointer ptrType isNewtype <- queryPointer typeIde
when (ptrType == CHSStablePtr) $
illegalStablePtrErr pos
classDef pos (identToString classIde) (identToString typeIde)
ptrType isNewtype superClasses
where
-- compile a list of all super classes (the direct super class first)
--
collectClasses :: Maybe Ident -> GB [(String, String, HsObject)]
collectClasses Nothing = return []
collectClasses (Just ide) =
do
Class oclassIde' typeIde' <- queryClass ide
ptr <- queryPointer (internalIdent typeIde')
classes <- collectClasses (fmap internalIdent oclassIde')
return $ (identToString ide, typeIde', ptr) : classes
--
traceInfoClass = traceGenBind $ "** Class hook:\n"
expandHook (CHSConst cIde _) _ =
do
traceGenBind "** Constant hook:\n"
Just (ObjCO cdecl) <- findObj cIde
let (Just ini) = initDeclr cdecl
return . show . pretty $ ini
expandHook (CHSTypedef cIde hsIde pos) _ =
do
traceGenBind $ "** Typedef hook: " ++ identToString cIde ++
" -> " ++ identToString hsIde ++ "\n"
let def = "__c2hs_typedef__" ++
identToString cIde ++ "__" ++ identToString hsIde
Just (ObjCO cdecl) <- findObj $ internalIdent def
st <- extractCompType True True False cdecl
et <- case st of
PrimET e -> return e
_ -> typeDefaultErr pos
cIde `isC2HSTypedef` (hsIde, et)
return ""
expandHook (CHSDefault dir hsTy cTy cPtr marsh pos) _ =
do
traceGenBind $ "** Default hook: " ++ hsTy ++ " [" ++ cTy ++
(if cPtr then " *" else "") ++ "]\n"
mtypedef <- queryTypedef $ internalIdent cTy
case mtypedef of
Nothing -> typeDefaultErr pos
Just (tdide, _) -> do
let def = "__c2hs_typedef__" ++ cTy ++ "__" ++ identToString tdide
Just (ObjCO cdecl) <- findObj $ internalIdent def
st <- extractCompType True True False cdecl
case st of
PrimET _ -> do
(dir, cTy, cPtr) `isDefaultMarsh` marsh
return ""
_ -> typeDefaultErr pos
apathNewtypeName :: CHSAPath -> GB (Maybe Ident)
apathNewtypeName path = do
let ide = apathRootIdent path
pm <- readCT ptrmap
case (True, ide) `lookup` pm of
Nothing -> return Nothing
Just (hsty, _) -> do
om <- readCT objmap
let hside = internalIdent hsty
case hside `lookup` om of
Just (Pointer _ True) -> return (Just hside)
_ -> return Nothing
-- | produce code for an enumeration
--
-- * an extra instance declaration is required when any of the enumeration
-- constants is explicitly assigned a value in its definition
--
-- * the translation function strips prefixes where possible (different
-- enumerators maye have different prefixes)
--
enumDef :: CEnum -> String -> TransFun -> Bool -> [String] -> Position
-> GB String
enumDef (CEnum _ Nothing _ _) _ _ _ _ pos = undefEnumErr pos
enumDef (CEnum _ (Just list) _ _) hident trans emit userDerive _ =
do
(list', enumAuto) <- evalTagVals list
let enumVals = map (\(Just i, e) -> (i, e)) $ filter (isJust . fst) $
fixTags [(trans ide, cexpr) | (ide, cexpr) <- list']
defHead = enumHead hident
defBody = enumBody (length defHead - 2) enumVals
dataDef = if emit then defHead ++ defBody else ""
inst = makeDerives
(if enumAuto then "Enum" : userDerive else userDerive) ++
"\n" ++
if enumAuto
then ""
else enumInst hident enumVals
isEnum hident
return $ dataDef ++ inst
where
evalTagVals = liftM (second and . unzip) . mapM (uncurry evalTag)
evalTag ide Nothing = return ((ide, Nothing), True)
evalTag ide (Just exp) = do
val <- evalConstCExpr exp
case val of
IntResult v -> return ((ide, Just v), False)
FloatResult _ -> illegalConstExprErr (posOf exp) "a float result"
makeDerives [] = ""
makeDerives dList = "\n deriving (" ++ intercalate "," dList ++ ")"
-- Fix implicit tag values
fixTags = go 0
where
go _ [] = []
go n ((ide, exp):rest) =
let val = case exp of
Nothing -> n
Just m -> m
in (ide, val) : go (val+1) rest
-- | Haskell code for the head of an enumeration definition
--
enumHead :: String -> String
enumHead ident = "data " ++ ident ++ " = "
-- | Haskell code for the body of an enumeration definition
--
enumBody :: Int -> [(String, Integer)] -> String
enumBody indent ides = constrs
where
constrs = intercalate separator . map fst $ sortBy (comparing snd) ides
separator = "\n" ++ replicate indent ' ' ++ "| "
-- | Num instance for C Integers
-- We should preserve type flags and repr if possible
instance Num CInteger where
fromInteger = cInteger
(+) a b = cInteger (getCInteger a + getCInteger b)
(*) a b = cInteger (getCInteger a * getCInteger b)
(-) a b = cInteger (getCInteger a - getCInteger b)
abs a = cInteger (abs $ getCInteger a)
signum a = cInteger (signum $ getCInteger a)
-- | Haskell code for an instance declaration for 'Enum'
--
-- * the expression of all explicitly specified tag values already have to be
-- in normal form, ie, to be an int constant
--
-- * enumerations start at 0 and whenever an explicit value is specified,
-- following tags are assigned values continuing from the explicitly
-- specified one
--
enumInst :: String -> [(String, Integer)] -> String
enumInst ident list' = intercalate "\n"
[ "instance Enum " ++ wrap ident ++ " where"
, succDef
, predDef
, enumFromToDef
, enumFromDef
, fromDef
, toDef
]
where
wrap s = if ' ' `elem` s then "(" ++ s ++ ")" else s
concatFor = flip concatMap
-- List of _all values_ (including aliases) and their associated tags
list = sortBy (comparing snd) list'
-- List of values without aliases and their associated tags
toList = stripAliases list
-- Generate explicit tags for all values:
succDef = let idents = map fst toList
aliases = map (map fst) $ groupBy ((==) `on` snd) list
defs = concat $ zipWith
(\is s -> concatFor is $ \i -> " succ " ++ i
++ " = " ++ s ++ "\n")
aliases
(tail idents)
lasts = concatFor (last aliases) $ \i ->
" succ " ++ i ++ " = error \""
++ ident ++ ".succ: " ++ i ++
" has no successor\"\n"
in defs ++ lasts
predDef = let idents = map fst toList
aliases = map (map fst) $ groupBy ((==) `on` snd) list
defs = concat $ zipWith
(\is s -> concatFor is $ \i -> " pred " ++ i
++ " = " ++ s ++ "\n")
(tail aliases)
idents
firsts = concatFor (head aliases) $ \i ->
" pred " ++ i ++ " = error \""
++ ident ++ ".pred: " ++ i ++
" has no predecessor\"\n"
in defs ++ firsts
enumFromToDef = intercalate "\n"
[ " enumFromTo from to = go from"
, " where"
, " end = fromEnum to"
, " go v = case compare (fromEnum v) end of"
, " LT -> v : go (succ v)"
, " EQ -> [v]"
, " GT -> []"
, ""
]
enumFromDef = let lastIdent = fst $ last list
in " enumFrom from = enumFromTo from " ++ lastIdent ++ "\n"
fromDef = concatFor list (\(ide, val) -> " fromEnum " ++ ide ++ " = "
++ show' val ++ "\n")
toDef = (concatFor toList (\(ide, val) -> " toEnum " ++ show' val ++ " = "
++ ide ++ "\n"))
-- Default case:
++ " toEnum unmatched = error (\"" ++ ident
++ ".toEnum: Cannot match \" ++ show unmatched)\n"
show' x = if x < 0 then "(" ++ show x ++ ")" else show x
stripAliases :: [(String, Integer)] -> [(String, Integer)]
stripAliases = nubBy ((==) `on` snd)
-- | generate a foreign import declaration that is put into the delayed code
--
-- * the C declaration is a simplified declaration of the function that we
-- want to import into Haskell land
--
callImport :: CHSHook -> Bool -> [ExtType] -> String ->
String -> CDecl -> Maybe [Bool] -> Position -> GB ()
callImport hook isUns varTypes ideLexeme hsLexeme cdecl owrapped pos =
do
-- compute the external type from the declaration, and delay the foreign
-- export declaration
--
extType <- extractFunType pos cdecl owrapped
header <- getSwitch headerSB
let bools@(boolres, boolargs) = boolArgs extType
needwrapper1 = boolres || or boolargs
(needwrapper2, wraps) = case owrapped of
Nothing -> (False, replicate (numArgs extType) False)
Just ws -> if or ws
then (True, ws)
else (False, replicate (numArgs extType) False)
ide = if needwrapper1 || needwrapper2
then "__c2hs_wrapped__" ++ ideLexeme
else ideLexeme
addExtTypeDependency extType
delayCode hook (foreignImport (extractCallingConvention cdecl)
header ide hsLexeme isUns extType varTypes)
when (needwrapper1 || needwrapper2) $
addWrapper ide ideLexeme cdecl wraps bools pos
traceFunType extType
where
traceFunType et = traceGenBind $
"Imported function type: " ++ showExtType et ++ "\n"
callImportDyn :: CHSHook -> Bool -> String -> String -> CDecl -> ExtType
-> Position -> GB ()
callImportDyn hook isUns ideLexeme hsLexeme cdecl ty pos =
do
-- compute the external type from the declaration, and delay the foreign
-- export declaration
--
when (isVariadic ty) (variadicErr pos (posOf cdecl))
addExtTypeDependency ty
delayCode hook (foreignImportDyn (extractCallingConvention cdecl)
ideLexeme hsLexeme isUns ty)
traceFunType ty
where
traceFunType et = traceGenBind $
"Imported function type: " ++ showExtType et ++ "\n"
-- | Haskell code for the foreign import declaration needed by a call hook
--
foreignImport :: CallingConvention -> String -> String -> String -> Bool ->
ExtType -> [ExtType] -> String
foreignImport cconv header ident hsIdent isUnsafe ty vas =
"foreign import " ++ showCallingConvention cconv ++ " " ++ safety
++ " " ++ show entity ++
"\n " ++ hsIdent ++ " :: " ++ showExtFunType ty vas ++ "\n"
where
safety = if isUnsafe then "unsafe" else "safe"
entity | null header = ident
| otherwise = header ++ " " ++ ident
-- | Haskell code for the foreign import dynamic declaration needed by
-- a call hook
--
foreignImportDyn :: CallingConvention -> String -> String -> Bool ->
ExtType -> String
foreignImportDyn cconv _ident hsIdent isUnsafe ty =
"foreign import " ++ showCallingConvention cconv ++ " " ++ safety
++ " \"dynamic\"\n " ++
hsIdent ++ " :: " ++ impm "FunPtr" ++ "( " ++
showExtType ty ++ " ) -> " ++ showExtType ty ++ "\n"
where
safety = if isUnsafe then "unsafe" else "safe"
-- | produce a Haskell function definition for a fun hook
--
-- * FIXME: There's an ugly special case in here: to support dynamic fun hooks
-- I had to add a special second marshaller for the first argument,
-- which, if present, is inserted just before the function call. This
-- is probably not the most elegant solution, it's just the only one I
-- can up with at the moment. If present, this special marshaller is
-- an io action (like 'peek' and unlike 'with'). -- US
funDef :: Bool -- pure function?
-> String -- name of the new Haskell function
-> String -- Haskell name of the foreign imported C function
-> ExtType -- simplified declaration of the C function
-> [ExtType] -- simplified declaration of the C function
-> Maybe String -- type context of the new Haskell function
-> [CHSParm] -- parameter marshalling description
-> CHSParm -- result marshalling description
-> Maybe String -- optional additional marshaller for first arg
-> Position -- source location of the hook
-> Position -- source location of the start of the hook
-> GB String -- Haskell code in text form
funDef isPure hsLexeme fiLexeme extTy varExtTys octxt parms
parm@(CHSParm _ hsParmTy _ _ _ _ _) marsh2 pos hkpos =
do
when (countPlus parms > 1 || isPlus parm) $ illegalPlusErr pos
(parms', parm') <- addDftMarshaller pos parms parm extTy varExtTys
traceMarsh parms' parm'
marshs <- zipWithM marshArg [1..] parms'
let
sig = hsLexeme ++ " :: " ++ funTy parms' parm' ++ "\n"
funArgs = [funArg | (funArg, _, _, _, _) <- marshs, funArg /= ""]
marshIns = [marshIn | (_, marshIn, _, _, _) <- marshs]
callArgs = [callArg | (_, _, cs, _, _) <- marshs, callArg <- cs]
marshOuts = [marshOut | (_, _, _, marshOut, _) <- marshs, marshOut /= ""]
retArgs = [retArg | (_, _, _, _, retArg) <- marshs, retArg /= ""]
funHead = hsLexeme ++ join funArgs ++ " =\n" ++
if isPure
then " " ++ impm "unsafePerformIO" ++ " $\n"
else ""
call = " " ++ fiLexeme ++ joinCallArgs ++ case parm of
CHSParm _ "()" _ Nothing _ _ _ -> " >>\n"
_ ->
if countPlus parms == 1
then " >>\n" else " >>= \\res ->\n"
joinCallArgs = case marsh2 of
Nothing -> join callArgs
Just _ -> join ("b1'" : drop 1 callArgs)
mkMarsh2 = case marsh2 of
Nothing -> ""
Just m -> " " ++ m ++ " " ++
join (take 1 callArgs) ++
" >>= \\b1' ->\n"
marshRes = if countPlus parms == 1
then ""
else case parm' of
CHSParm _ _ _twoCVal (Just (_, CHSVoidArg)) _ _ _ -> ""
CHSParm _ _ _twoCVal (Just (omBody, CHSIOVoidArg)) _ _ _ ->
" " ++ marshBody omBody ++ " res >> \n"
CHSParm _ _ _twoCVal (Just (omBody, CHSIOArg)) _ _ _ ->
" " ++ marshBody omBody ++ " res >>= \\res' ->\n"
CHSParm _ _ _twoCVal (Just (omBody, CHSValArg)) _ _ _ ->
" let {res' = " ++ marshBody omBody ++ " res} in\n"
CHSParm _ _ _ Nothing _ _ _ ->
interr "GenBind.funDef: marshRes: no default?"
marshBody (Left ide) = identToString ide
marshBody (Right str) = "(" ++ str ++ ")"
retArgs' = case parm' of
CHSParm _ _ _ (Just (_, CHSVoidArg)) _ _ _ -> retArgs
CHSParm _ _ _ (Just (_, CHSIOVoidArg)) _ _ _ -> retArgs
_ ->
if countPlus parms == 0 then "res'":retArgs else retArgs
ret = "(" ++ concat (intersperse ", " retArgs') ++ ")"
funBody = joinLines marshIns ++
mkMarsh2 ++
call ++
marshRes ++
joinLines marshOuts ++
" return " ++ ret
pad code = let padding = replicate (posColumn hkpos - 1) ' '
(l:ls) = lines code
in unlines $ l : map (padding ++) ls
when isPure $ addHsDependency "System.IO.Unsafe"
return $ pad $ sig ++ funHead ++ funBody
where
countPlus :: [CHSParm] -> Int
countPlus = sum . map (\p -> if isPlus p then 1 else 0)
isPlus (CHSPlusParm _) = True
isPlus _ = False
join = concatMap (' ':)
joinLines = concatMap (\s -> " " ++ s ++ "\n")
--
-- construct the function type
--
-- * specified types appear in the argument and result only if their "in"
-- and "out" marshaller, respectively, is not the `void' marshaller
--
funTy parms' parm' =
let
showComment str = if null str
then ""
else " --" ++ str ++ "\n"
ctxt = case octxt of
Nothing -> ""
Just ctxtStr -> ctxtStr ++ " => "
argTys = ["(" ++ ty ++ ")" ++ showComment c |
CHSParm im ty _ _ _ _ c <- parms', notVoid im]
resTys = ["(" ++ ty ++ ")" |
CHSParm _ ty _ om _ _ _ <- parm':parms', notVoid om]
resTup = let
comment = case parm' of
CHSParm _ _ _ _ _ _ c -> c
(lp, rp) = if isPure && length resTys == 1
then ("", "")
else ("(", ")")
io = if isPure then "" else "IO "
in
io ++ lp ++ concat (intersperse ", " resTys) ++ rp ++
showComment comment
in
ctxt ++ concat (intersperse " -> " (argTys ++ [resTup]))
where
notVoid Nothing
= interr "GenBind.funDef: No default marshaller?"
notVoid (Just (_, kind)) = kind /= CHSVoidArg && kind /= CHSIOVoidArg
--
-- for an argument marshaller, generate all "in" and "out" marshalling
-- code fragments
--
marshArg i (CHSParm (Just (imBody, imArgKind)) _ twoCVal
(Just (omBody, omArgKind)) _ _ _ ) = do
let
a = "a" ++ show (i :: Int)
imStr = marshBody imBody
imApp = imStr ++ " " ++ a
funArg = if imArgKind == CHSVoidArg then "" else a
inBndr = if twoCVal
then "(" ++ a ++ "'1, " ++ a ++ "'2)"
else a ++ "'"
marshIn = case imArgKind of
CHSVoidArg -> imStr ++ " $ \\" ++ inBndr ++ " -> "
CHSIOArg -> imApp ++ " $ \\" ++ inBndr ++ " -> "
CHSValArg -> "let {" ++ inBndr ++ " = " ++
imApp ++ "} in "
callArgs = if twoCVal
then [a ++ "'1 ", a ++ "'2"]
else [a ++ "'"]
omApp = marshBody omBody ++ " " ++ join callArgs
outBndr = a ++ "''"
marshOut = case omArgKind of
CHSVoidArg -> ""
CHSIOVoidArg -> omApp ++ ">>"
CHSIOArg -> omApp ++ ">>= \\" ++ outBndr ++ " -> "
CHSValArg -> "let {" ++ outBndr ++ " = " ++
omApp ++ "} in "
retArg = if omArgKind == CHSVoidArg || omArgKind == CHSIOVoidArg
then "" else outBndr
marshBody (Left ide) = identToString ide
marshBody (Right str) = "(" ++ str ++ ")"
return (funArg, marshIn, callArgs, marshOut, retArg)
marshArg i (CHSPlusParm ptype) = do
szstr <- case ptype of
CHSPlusBare -> do
msize <- querySize $ internalIdent hsParmTy
case msize of
Nothing -> interr "Missing size for \"+\" parameter allocation!"
Just sz -> return $ show sz
CHSPlusS -> return $ "(sizeOf (undefined :: " ++ hsParmTy ++ "))"
CHSPlusNum sz -> return $ show sz
let a = "a" ++ show (i :: Int)
bdr1 = a ++ "'"
bdr2 = a ++ "''"
marshIn = impm "mallocForeignPtrBytes" ++ " " ++ szstr ++
" >>= \\" ++ bdr2 ++
" -> " ++ impm "withForeignPtr" ++ " " ++ bdr2 ++
" $ \\" ++ bdr1 ++ " -> "
addHsDependency "Foreign.ForeignPtr"
return ("", marshIn, [bdr1], "", hsParmTy ++ " " ++ bdr2)
marshArg _ _ = interr "GenBind.funDef: Missing default?"
--
traceMarsh parms' parm' = traceGenBind $
"Marshalling specification including defaults: \n" ++
showParms (parms' ++ [parm']) "\n"
where
showParms [] = id
showParms (parm'':parms'') = showString " "
. showCHSParm parm''
. showChar '\n'
. showParms parms''
-- | add default marshallers for "in" and "out" marshalling
--
addDftMarshaller :: Position -> [CHSParm] -> CHSParm -> ExtType -> [ExtType]
-> GB ([CHSParm], CHSParm)
addDftMarshaller pos parms parm extTy varExTys = do
let (resTy, argTys) = splitFunTy extTy varExTys
parm' <- checkResMarsh parm resTy
parms' <- addDft parms argTys
return (parms', parm')
where
-- the result marshalling may not use an "in" marshaller and can only have
-- one C value
--
-- * a default marshaller maybe used for "out" marshalling
--
checkResMarsh (CHSParm (Just _) _ _ _ _ pos' _) _ =
resMarshIllegalInErr pos'
checkResMarsh (CHSParm _ _ True _ _ pos' _) _ =
resMarshIllegalTwoCValErr pos'
checkResMarsh (CHSParm _ ty _ omMarsh _ pos' c) cTy = do
imMarsh' <- addDftVoid Nothing
omMarsh' <- addDftOut pos' omMarsh ty [cTy]
return (CHSParm imMarsh' ty False omMarsh' False pos' c)
--
splitFunTy (FunET UnitET ty) vts = splitFunTy ty vts
splitFunTy (FunET ty1 ty2) vts = let (resTy, argTys) = splitFunTy ty2 vts
in (resTy, ty1:argTys)
splitFunTy (VarFunET ty2) vts = let (resTy, argTys) = splitFunTy ty2 []
in (resTy, argTys ++ vts)
splitFunTy resTy _ = (resTy, [])
--
-- match Haskell with C arguments (and results)
--
addDft (p@(CHSPlusParm _):parms'') (_:cTys) = do
parms' <- addDft parms'' cTys
return (p : parms')
addDft ((CHSParm imMarsh hsTy False omMarsh _ p c):parms'') (cTy:cTys) = do
imMarsh' <- addDftIn p imMarsh hsTy [cTy]
omMarsh' <- addDftVoid omMarsh
parms' <- addDft parms'' cTys
return (CHSParm imMarsh' hsTy False omMarsh' False p c : parms')
addDft ((CHSParm imMarsh hsTy True omMarsh _ p c):parms'') (ct1:ct2:cts) =
do
imMarsh' <- addDftIn p imMarsh hsTy [ct1, ct2]
omMarsh' <- addDftVoid omMarsh
parms' <- addDft parms'' cts
return (CHSParm imMarsh' hsTy True omMarsh' False p c : parms')
addDft [] [] = return []
addDft (CHSPlusParm _:_) [] =
marshArgMismatchErr pos "This parameter is in excess of the C arguments."
addDft (CHSParm _ _ _ _ _ pos' _:_) [] =
marshArgMismatchErr pos' "This parameter is in excess of the C arguments."
addDft (CHSParm _ _ True _ _ pos' _:_) [_] =
marshArgMismatchErr pos' "This parameter is in excess of the C arguments."
addDft [] (_:_) =
marshArgMismatchErr pos "Parameter marshallers are missing."
--
addDftIn _ imMarsh@(Just (_, _)) _ _ = return imMarsh
addDftIn pos' _imMarsh@Nothing hsTy cts = do
marsh <- lookupDftMarshIn hsTy cts
when (isNothing marsh) $ noDftMarshErr pos' "\"in\"" hsTy cts
return marsh
--
addDftOut _ omMarsh@(Just (_, _)) _ _ = return omMarsh
addDftOut pos' _omMarsh@Nothing hsTy cts = do
marsh <- lookupDftMarshOut hsTy cts
when (isNothing marsh) $ noDftMarshErr pos' "\"out\"" hsTy cts
return marsh
--
-- add void marshaller if no explict one is given
--
addDftVoid marsh@(Just (_, _)) = return marsh
addDftVoid Nothing = return $ Just (Left (internalIdent "void"), CHSVoidArg)
-- | compute from an access path, the declarator finally accessed and the index
-- path required for the access
--
-- * each element in the index path specifies dereferencing an address and the
-- offset to be added to the address before dereferencing
--
-- * the returned declaration is already normalised (ie, alias have been
-- expanded)
--
-- * it may appear as if `t.m' and `t->m' should have different access paths,
-- as the latter specifies one more dereferencing; this is certainly true in
-- C, but it doesn't apply here, as `t.m' is merely provided for the
-- convenience of the interface writer - it is strictly speaking an
-- impossible access paths, as in Haskell we always have a pointer to a
-- structure, we can never have the structure as a value itself
--
accessPath :: CHSAPath -> GB (CDecl, [BitSize])
accessPath (CHSRoot _ ide) = -- t
do
decl <- findAndChaseDecl ide False True
return (ide `simplifyDecl` decl, [BitSize 0 0])
accessPath (CHSDeref (CHSRoot _ ide) _) = -- *t
do
decl <- findAndChaseDecl ide True True
return (ide `simplifyDecl` decl, [BitSize 0 0])
accessPath (CHSRef (CHSRoot str ide1) ide2) = -- t.m
do
su <- lookupStructUnion ide1 str True
(offset, decl') <- refStruct su ide2
adecl <- replaceByAlias decl'
return (adecl, [offset])
accessPath (CHSRef (CHSDeref (CHSRoot str ide1) _) ide2) = -- t->m
do
su <- lookupStructUnion ide1 str True
(offset, decl') <- refStruct su ide2
adecl <- replaceByAlias decl'
return (adecl, [offset])
accessPath (CHSRef path ide) = -- a.m
do
(decl, offset:offsets) <- accessPath path
assertPrimDeclr ide decl
su <- structFromDecl (posOf ide) decl
(addOffset, decl') <- refStruct su ide
adecl <- replaceByAlias decl'
return (adecl, offset `addBitSize` addOffset : offsets)
where
assertPrimDeclr ide' (CDecl _ [declr] _) =
case declr of
(Just (CDeclr _ [] _ _ _), _, _) -> return ()
_ -> structExpectedErr ide'
accessPath (CHSDeref path _pos) = -- *a
do
(decl, offsets) <- accessPath path
decl' <- derefOrErr decl
adecl <- replaceByAlias decl'
return (adecl, BitSize 0 0 : offsets)
where
derefOrErr (CDecl specs [(Just declr, oinit, oexpr)] at) =
do
declr' <- derefDeclr declr
return $ CDecl specs [(Just declr', oinit, oexpr)] at
derefDeclr (CDeclr oid (CPtrDeclr _ _: derived') asm ats n) =
return $ CDeclr oid derived' asm ats n
derefDeclr (CDeclr _oid _unexp_deriv _ _ n) = ptrExpectedErr (posOf n)
-- | replaces a decleration by its alias if any
--
-- * the alias inherits any field size specification that the original
-- declaration may have
--
-- * declaration must have exactly one declarator
--
replaceByAlias :: CDecl -> GB CDecl
replaceByAlias cdecl@(CDecl _ [(_, _, sz)] _at) =
do
ocdecl <- checkForAlias cdecl
case ocdecl of
Nothing -> return cdecl
Just (CDecl specs [(declr, init', _)] at) -> -- form of an alias
return $ CDecl specs [(declr, init', sz)] at
-- | given a structure declaration and member name, compute the offset of the
-- member in the structure and the declaration of the referenced member
--
refStruct :: CStructUnion -> Ident -> GB (BitSize, CDecl)
refStruct su ide =
do
-- get the list of fields and check for our selector
--
let (fields, tag) = structMembers su
(pre, post) = span (not . flip declNamed ide) fields
when (null post) $
unknownFieldErr (posOf su) ide
--
-- get sizes of preceding fields and the result type (`pre' are all
-- declarators preceding `ide' and the first declarator in `post' defines
-- `ide')
--
let decl = head post
offset <- case tag of
CStructTag -> offsetInStruct pre decl tag
CUnionTag -> return $ BitSize 0 0
return (offset, decl)
-- | does the given declarator define the given name?
--
declNamed :: CDecl -> Ident -> Bool
(CDecl _ [(Nothing , _, _)] _) `declNamed` _ = False
(CDecl _ [(Just declr, _, _)] _) `declNamed` ide = declr `declrNamed` ide
cdecl@(CDecl _ [] _) `declNamed` _ =
errorAtPos (posOf cdecl) ["GenBind.declNamed: Abstract declarator in structure!"]
cdecl `declNamed` _ =
errorAtPos (posOf cdecl) ["GenBind.declNamed: More than one declarator!"]
-- | Haskell code for writing to or reading from a struct
--
setGet :: Position -> CHSAccess -> [BitSize] -> Maybe Int ->
ExtType -> Maybe Ident -> GB String
setGet pos access offsets arrSize ty onewtype =
do
let pre = case (access, onewtype) of
(CHSSet, Nothing) -> "(\\ptr val -> do {"
(CHSGet, Nothing) -> "(\\ptr -> do {"
(CHSSet, Just ide) ->
"(\\(" ++ identToString ide ++ " ptr) val -> do {"
(CHSGet, Just ide) ->
"(\\(" ++ identToString ide ++ " ptr) -> do {"
body <- setGetBody (reverse offsets)
return $ pre ++ body ++ "})"
where
setGetBody [BitSize offset bitOffset] =
do
bf <- checkType ty
case bf of
Nothing -> case access of -- not a bitfield
CHSGet -> peekOp offset ty arrSize
CHSSet -> pokeOp offset ty "val" arrSize
--FIXME: must take `bitfieldDirection' into account
Just (_, bs) -> case access of -- a bitfield
CHSGet -> do
op <- peekOp offset ty arrSize
addHsDependency "Data.Bits"
addHsDependency "Foreign.C.Types"
return $ "val <- " ++ op ++ extractBitfield
CHSSet -> do
op <- peekOp offset ty arrSize
op2 <- pokeOp offset ty "val'" arrSize
addHsDependency "Data.Bits"
addHsDependency "Foreign.C.Types"
return $ "org <- " ++ op ++ insertBitfield
++ op2
where
-- we have to be careful here to ensure proper sign extension;
-- in particular, shifting right followed by anding a mask is
-- *not* sufficient; instead, we exploit in the following that
-- `shiftR' performs sign extension
--
extractBitfield = "; return $ (val `" ++ impm "shiftL" ++ "` ("
++ bitsPerField ++ " - "
++ show (bs + bitOffset) ++ ")) `"
++ impm "shiftR" ++ "` ("
++ bitsPerField ++ " - " ++ show bs
++ ")"
bitsPerField = show $ size CIntPT * 8
--
insertBitfield = "; let {val' = (org " ++ impm ".&." ++ " "
++ middleMask ++ ") " ++ impm ".|."
++ " (val `" ++ impm "shiftL" ++ "` "
++ show bitOffset ++ ")}; "
middleMask = "fromIntegral (((maxBound::" ++ impm "CUInt"
++ ") `" ++ impm "shiftL" ++ "` "
++ show bs ++ ") `" ++ impm "rotateL" ++ "` "
++ show bitOffset ++ ")"
setGetBody (BitSize offset 0 : offsetsrem) =
do
code <- setGetBody offsetsrem
addHsDependency "Foreign.Storable"
return $ "ptr <- " ++ impm "peekByteOff" ++ " ptr "
++ show offset ++ "; " ++ code
setGetBody (BitSize _ _ : _ ) =
derefBitfieldErr pos
--
-- check that the type can be marshalled and compute extra operations for
-- bitfields
--
checkType (VarFunET _ ) = variadicErr pos pos
checkType (IOET _ ) = errorAtPos pos ["GenBind.setGet: Illegal \
\type!"]
checkType (UnitET ) = voidFieldErr pos
checkType (DefinedET _ _ ) = return Nothing-- can't check further
checkType (PrimET (CUFieldPT bs)) = return $ Just (False, bs)
checkType (PrimET (CSFieldPT bs)) = return $ Just (True , bs)
checkType _ = return Nothing
--
peekOp off (PrimET CBoolPT) Nothing = do
addHsDependency "Foreign.Marshal.Utils"
addHsDependency "Foreign.C.Types"
addHsDependency "Foreign.Storable"
return $ impm "toBool" ++ " `fmap` (" ++ impm "peekByteOff"
++ " ptr " ++ show off ++ " :: IO " ++ impm "CInt" ++ ")"
peekOp off t Nothing = do
addHsDependency "Foreign.Storable"
addExtTypeDependency t
return $ impm "peekByteOff" ++ " ptr " ++ show off
++ " :: IO " ++ showExtType t
peekOp off t (Just _) = do
addHsDependency "Foreign.Ptr"
addExtTypeDependency t
return $ "return $ ptr `" ++ impm "plusPtr" ++ "` " ++ show off ++
" :: IO " ++ showExtType t
pokeOp off (PrimET CBoolPT) var Nothing = do
addHsDependency "Foreign.Marshal.Utils"
addHsDependency "Foreign.C.Types"
addHsDependency "Foreign.Storable"
return $ impm "pokeByteOff" ++ " ptr " ++ show off
++ " (" ++ impm "fromBool" ++ " " ++
var ++ " :: " ++ impm "CInt" ++ ")"
pokeOp off t var Nothing = do
addHsDependency "Foreign.Storable"
addExtTypeDependency t
return $ impm "pokeByteOff" ++ " ptr " ++ show off ++ " (" ++ var ++ " :: " ++
showExtType t ++ ")"
pokeOp off t var (Just sz) = do
addHsDependency "Foreign.Ptr"
addHsDependency "Foreign.Marshal.Array"
addExtTypeDependency t
return $ impm "copyArray" ++ " (ptr `" ++ impm "plusPtr" ++ "` "
++ show off ++ ") (" ++
var ++ " :: " ++ showExtType t ++ ") " ++ show sz
-- | generate the type definition for a pointer hook and enter the required type
-- mapping into the 'ptrmap'
--
pointerDef :: Bool -- explicit `*' in pointer hook
-> Ident -- full C name
-> String -- Haskell name
-> CHSPtrType -- kind of the pointer
-> Bool -- explicit newtype tag
-> String -- Haskell type expression of pointer argument
-> Bool -- do we have a pointer to a function?
-> Bool -- shall we emit code?
-> GB String
pointerDef isStar cNameFull hsName ptrKind isNewtype hsType isFun emit =
do
let ptrArg = if isNewtype
then hsName -- abstract type
else hsType -- concrete type
ptrCon = case ptrKind of
CHSPtr | isFun -> impm "FunPtr"
_ -> impm $ show ptrKind
ptrType = ptrCon ++ " (" ++ ptrArg ++ ")"
thePtr = (isStar, cNameFull)
case ptrKind of
CHSPtr -> addHsDependency "Foreign.Ptr"
CHSForeignPtr _ -> do
addHsDependency "Foreign.ForeignPtr"
addHsDependency "Foreign.Ptr"
CHSStablePtr -> addHsDependency "Foreign.StablePtr"
case ptrKind of
CHSForeignPtr _ -> do
thePtr `ptrMapsTo` (impm "Ptr (" ++ ptrArg ++ ")",
impm "Ptr (" ++ ptrArg ++ ")")
_ -> thePtr `ptrMapsTo` (hsName, hsName)
return $
case (emit, isNewtype) of
(False, _) -> "" -- suppress code generation
(True , True) ->
"newtype " ++ hsName ++ " = " ++ hsName ++ " (" ++ ptrType ++ ")" ++
withForeignFun
(True , False) ->
"type " ++ hsName ++ " = " ++ ptrType
where
-- if we have a foreign pointer wrapped into a newtype, provide a
-- safe unwrapping function automatically
--
withForeignFun
| isForeign ptrKind =
"\nwith" ++ hsName ++ " :: " ++
hsName ++ " -> (" ++ impm "Ptr" ++ " " ++ hsName
++ " -> IO b) -> IO b" ++
"\n" ++ "with" ++ hsName ++ " (" ++ hsName ++
" fptr) = " ++ impm "withForeignPtr" ++ " fptr"
| otherwise = ""
isForeign (CHSForeignPtr _) = True
isForeign _ = False
-- | generate a foreign pointer finalizer import declaration that is
-- put into the delayed code
--
doFinalizer :: CHSHook -> CHSPtrType -> String -> GB ()
doFinalizer hook (CHSForeignPtr (Just (cide, ohside))) ptrHsIde = do
(ObjCO cdecl, cide') <- findFunObj cide True
let finCIde = identToString cide'
finHsIde = finCIde `maybe` identToString $ ohside
cdecl' = cide' `simplifyDecl` cdecl
header <- getSwitch headerSB
addHsDependency "Foreign.ForeignPtr"
delayCode hook (finalizerImport (extractCallingConvention cdecl')
header finCIde finHsIde ptrHsIde)
traceFunType ptrHsIde
where
traceFunType et = traceGenBind $
"Imported finalizer function type: " ++ et ++ "\n"
doFinalizer _ _ _ = return ()
-- | Haskell code for the foreign import declaration needed by foreign
-- pointer finalizers.
--
finalizerImport :: CallingConvention -> String -> String -> String ->
String -> String
finalizerImport cconv header ident hsIdent hsPtrName =
"foreign import " ++ showCallingConvention cconv ++ " " ++ show entity ++
"\n " ++ hsIdent ++ " :: " ++ impm "FinalizerPtr" ++ " " ++ hsPtrName ++ "\n"
where
entity | null header = "&" ++ ident
| otherwise = header ++ " &" ++ ident
-- | generate the class and instance definitions for a class hook
--
-- * the pointer type must not be a stable pointer
--
-- * the first super class (if present) must be the direct superclass
--
-- * all Haskell objects in the superclass list must be pointer objects
--
classDef :: Position -- for error messages
-> String -- class name
-> String -- pointer type name
-> CHSPtrType -- type of the pointer
-> Bool -- is a newtype?
-> [(String, String, HsObject)] -- superclasses
-> GB String
classDef pos className typeName ptrType isNewtype superClasses =
do
let
toMethodName = case typeName of
"" -> errorAtPos pos ["GenBind.classDef: Illegal identifier!"]
c:cs -> toLower c : cs
fromMethodName = "from" ++ typeName
classDefContext = case superClasses of
[] -> ""
(superName, _, _):_ -> superName ++ " p => "
classDefStr =
"class " ++ classDefContext ++ className ++ " p where\n"
++ " " ++ toMethodName ++ " :: p -> " ++ typeName ++ "\n"
++ " " ++ fromMethodName ++ " :: " ++ typeName ++ " -> p\n"
instDef =
"instance " ++ className ++ " " ++ typeName ++ " where\n"
++ " " ++ toMethodName ++ " = id\n"
++ " " ++ fromMethodName ++ " = id\n"
instDefs <- castInstDefs superClasses
return $ classDefStr ++ instDefs ++ instDef
where
castInstDefs [] = return ""
castInstDefs ((superName, ptrName, Pointer ptrType' isNewtype'):classes) =
do
unless (ptrType == ptrType') $
pointerTypeMismatchErr pos className superName
let toMethodName = case ptrName of
"" -> errorAtPos pos ["GenBind.classDef: Illegal identifier - 2!"]
c:cs -> toLower c : cs
fromMethodName = "from" ++ ptrName
castFun = impm $ "cast" ++ show ptrType
typeConstr = if isNewtype then typeName ++ " " else ""
superConstr = if isNewtype' then ptrName ++ " " else ""
instDef =
"instance " ++ superName ++ " " ++ typeName ++ " where\n"
++ " " ++ toMethodName ++ " (" ++ typeConstr ++ "p) = "
++ superConstr ++ "(" ++ castFun ++ " p)\n"
++ " " ++ fromMethodName ++ " (" ++ superConstr ++ "p) = "
++ typeConstr ++ "(" ++ castFun ++ " p)\n"
addHsDependency "Foreign.Ptr"
instDefs <- castInstDefs classes
return $ instDef ++ instDefs
-- C code computations
-- -------------------
-- | the result of a constant expression
--
data ConstResult = IntResult Integer
| FloatResult Float
-- | types that may occur in foreign declarations, ie, Haskell land types
--
-- * we reprsent C functions with no arguments (ie, the ANSI C `void'
-- argument) by `FunET UnitET res' rather than just `res' internally,
-- although the latter representation is finally emitted into the binding
-- file; this is because we need to know which types are functions (in
-- particular, to distinguish between `Ptr a' and `FunPtr a')
--
-- * aliased types (`DefinedET') are represented by a string plus their C
-- declaration; the latter is for functions interpreting the following
-- structure; an aliased type is always a pointer type that is contained in
-- the pointer map (and got there either from a .chi or from a pointer hook
-- in the same module)
--
-- * the representation for pointers does not distinguish between normal,
-- function, foreign, and stable pointers; function pointers are identified
-- by their argument and foreign and stable pointers are only used
-- indirectly, by referring to type names introduced by a `pointer' hook
--
data ExtType = FunET ExtType ExtType -- function
| IOET ExtType -- operation with side effect
| PtrET ExtType -- typed pointer
| DefinedET CDecl String -- aliased type
| PrimET CPrimType -- basic C type
| UnitET -- void
| VarFunET ExtType -- variadic function
| SUET CStructUnion -- structure or union
deriving Show
instance Eq ExtType where
(FunET t1 t2) == (FunET t1' t2') = t1 == t1' && t2 == t2'
(IOET t ) == (IOET t' ) = t == t'
(PtrET t ) == (PtrET t' ) = t == t'
(DefinedET _ s ) == (DefinedET _ s' ) = s == s'
(PrimET t ) == (PrimET t' ) = t == t'
(VarFunET t ) == (VarFunET t' ) = t == t'
(SUET (CStruct _ i _ _ _)) == (SUET (CStruct _ i' _ _ _)) = i == i'
UnitET == UnitET = True
-- | check whether an external type denotes a function type
--
isFunExtType :: ExtType -> Bool
isFunExtType (FunET _ _) = True
isFunExtType (VarFunET _ ) = True
isFunExtType (IOET _ ) = True
isFunExtType _ = False
numArgs :: ExtType -> Int
numArgs (FunET UnitET f) = numArgs f
numArgs (FunET _ f) = 1 + numArgs f
numArgs _ = 0
boolArgs :: ExtType -> (Bool, [Bool])
boolArgs (FunET a rest@(FunET _ _)) =
let (res, as) = boolArgs rest in (res, boolArg a : as)
boolArgs (FunET a (IOET res) ) = boolArgs (FunET a res)
boolArgs (FunET a (PrimET CBoolPT)) = (True, [boolArg a])
boolArgs (FunET a _ ) = (False, [boolArg a])
boolArgs _ = (False, [])
boolArg :: ExtType -> Bool
boolArg (PrimET CBoolPT) = True
boolArg _ = False
-- | pretty print an external type
--
-- * a previous version of this function attempted to not print unnecessary
-- brackets; this however doesn't work consistently due to `DefinedET'; so,
-- we give up on the idea (preferring simplicity)
--
showExtType :: ExtType -> String
showExtType (FunET UnitET res) = showExtType res
showExtType (FunET arg res) = "(" ++ showExtType arg ++ " -> "
++ showExtType res ++ ")"
showExtType (VarFunET res) = "( ... -> " ++ showExtType res ++ ")"
showExtType (IOET t) = "(IO " ++ showExtType t ++ ")"
showExtType (PtrET t) = let ptrCon = if isFunExtType t
then impm "FunPtr"
else impm "Ptr"
in
"(" ++ ptrCon ++ " " ++ showExtType t
++ ")"
showExtType (DefinedET _ str) = "(" ++ str ++ ")"
showExtType (PrimET CPtrPT) = "(" ++ impm "Ptr" ++ " ())"
showExtType (PrimET CFunPtrPT) = "(" ++ impm "FunPtr" ++ " ())"
showExtType (PrimET CCharPT) = impm "CChar"
showExtType (PrimET CUCharPT) = impm "CUChar"
showExtType (PrimET CSCharPT) = impm "CSChar"
showExtType (PrimET CIntPT) = impm "CInt"
showExtType (PrimET CShortPT) = impm "CShort"
showExtType (PrimET CLongPT) = impm "CLong"
showExtType (PrimET CLLongPT) = impm "CLLong"
showExtType (PrimET CUIntPT) = impm "CUInt"
showExtType (PrimET CUShortPT) = impm "CUShort"
showExtType (PrimET CULongPT) = impm "CULong"
showExtType (PrimET CULLongPT) = impm "CULLong"
showExtType (PrimET CFloatPT) = impm "CFloat"
showExtType (PrimET CDoublePT) = impm "CDouble"
showExtType (PrimET CLDoublePT) = impm "CLDouble"
showExtType (PrimET CBoolPT) = impm "CInt{-bool-}"
showExtType (PrimET (CSFieldPT bs)) = impm "CInt{-:" ++ show bs ++ "-}"
showExtType (PrimET (CUFieldPT bs)) = impm "CUInt{-:" ++ show bs ++ "-}"
showExtType (PrimET (CAliasedPT _ hs _)) = hs
showExtType UnitET = "()"
showExtType (SUET _) = "(" ++ impm "Ptr" ++ " ())"
addExtTypeDependency :: ExtType -> GB ()
addExtTypeDependency (FunET UnitET res) = addExtTypeDependency res
addExtTypeDependency (FunET arg res) = do
addExtTypeDependency arg
addExtTypeDependency res
addExtTypeDependency (VarFunET res) = addExtTypeDependency res
addExtTypeDependency (IOET t) = addExtTypeDependency t
addExtTypeDependency (PtrET t) = do
addHsDependency "Foreign.Ptr"
addExtTypeDependency t
addExtTypeDependency (PrimET CPtrPT) = addHsDependency "Foreign.Ptr"
addExtTypeDependency (PrimET CFunPtrPT) = addHsDependency "Foreign.Ptr"
addExtTypeDependency (PrimET (CAliasedPT _ _ _)) = return ()
addExtTypeDependency (PrimET _) = addHsDependency "Foreign.C.Types"
addExtTypeDependency (SUET _) = addHsDependency "Foreign.Ptr"
addExtTypeDependency _ = return ()
showExtFunType :: ExtType -> [ExtType] -> String
showExtFunType (FunET UnitET res) _ = showExtType res
showExtFunType (FunET arg res) vas =
"(" ++ showExtType arg ++ " -> " ++ showExtFunType res vas ++ ")"
showExtFunType (VarFunET res) [] = showExtFunType res []
showExtFunType t@(VarFunET _) (va:vas) =
"(" ++ showExtType va ++ " -> " ++ showExtFunType t vas ++ ")"
showExtFunType (IOET t) vas = "(IO " ++ showExtFunType t vas ++ ")"
showExtFunType t _ = showExtType t
-- | compute the type of the C function declared by the given C object
--
-- * the identifier specifies in which of the declarators we are interested
--
-- * the function result is wrapped into an 'IO' type
--
-- * the caller has to guarantee that the object does indeed refer to a
-- function
--
extractFunType :: Position -> CDecl -> Maybe [Bool] -> GB ExtType
extractFunType pos cdecl wrapped =
do
-- remove all declarators except that of the function we are processing;
-- then, extract the functions arguments and result type (also check that
-- the function is not variadic); finally, compute the external type for
-- the result
--
let (args, resultDecl, variadic) = funResultAndArgs cdecl
preResultType <- extractSimpleType True pos resultDecl
--
-- we can now add the 'IO' monad if this is no pure function
--
let protoResultType = IOET preResultType
let resultType = if variadic
then VarFunET protoResultType
else protoResultType
--
-- compute function arguments and create a function type (a function
-- prototype with `void' as its single argument declares a nullary
-- function)
--
let wrap = case wrapped of
Just w -> w ++ repeat False
Nothing -> repeat False
argTypes <- zipWithM (extractCompType False True) wrap args
return $ foldr FunET resultType argTypes
-- | compute a non-struct/union type from the given declaration
--
-- * the declaration may have at most one declarator
--
extractSimpleType :: Bool -> Position -> CDecl -> GB ExtType
extractSimpleType isResult _ cdecl = extractCompType isResult True False cdecl
-- | compute a Haskell type for a type referenced in a C pointer type
--
-- * the declaration may have at most one declarator
--
-- * unknown struct/union types are mapped to '()'
--
-- * do *not* take aliases into account
--
-- * NB: this is by definition not a result type
--
extractPtrType :: CDecl -> GB ExtType
extractPtrType cdecl = do
ct <- extractCompType False False False cdecl
case ct of
SUET _ -> return UnitET
_ -> return ct
-- | compute a Haskell type from the given C declaration, where C functions are
-- represented by function pointers
--
-- * the declaration may have at most one declarator
--
-- * typedef'ed types are chased
--
-- * the first argument specifies whether the type specifies the result of a
-- function (this is only applicable to direct results and not to type
-- parameters for pointers that are a result)
--
-- * takes the pointer map into account
--
-- * IMPORTANT NOTE: `sizeAlignOf' relies on `DefinedET' only being produced
-- for pointer types; if this ever changes, we need to
-- handle `DefinedET's differently. The problem is that
-- entries in the pointer map currently prevent
-- `extractCompType' from looking further "into" the
-- definition of that pointer.
--
extractCompType :: Bool -> Bool -> Bool -> CDecl -> GB ExtType
extractCompType isResult usePtrAliases isPtr cdecl@(CDecl specs' declrs ats) =
if length declrs > 1
then errorAtPos (posOf cdecl) ["GenBind.extractCompType: Too many declarators!"]
else case declrs of
[(Just declr, _, sz)] | isPtr || isPtrDeclr declr -> ptrType declr
| isFunDeclr declr -> funType
| otherwise -> aliasOrSpecType sz
_ -> aliasOrSpecType Nothing
where
-- handle explicit pointer types
--
ptrType declr = do
tracePtrType
let declrs' = if isPtr -- remove indirection
then declr
else dropPtrDeclr declr
cdecl' = CDecl specs' [(Just declrs', Nothing, Nothing)] ats
oalias = checkForOneAliasName cdecl' -- is only an alias remaining?
osu = checkForOneCUName cdecl'
oname = if oalias == Nothing then osu else oalias
oHsRepr <- case oname of
Nothing -> return $ Nothing
Just ide -> queryPtr (True, ide)
case oHsRepr of
Just repr | usePtrAliases -> ptrAlias repr -- got an alias
_ -> do -- no alias => recurs
ct <- extractCompType False usePtrAliases False cdecl'
return $ case ct of
SUET _ -> PtrET UnitET
_ -> PtrET ct
--
-- handle explicit function types
--
-- FIXME: we currently regard any functions as being impure (ie, being IO
-- functions); is this ever going to be a problem?
--
funType = do
traceFunType
-- ??? IS Nothing OK HERE?
extractFunType (posOf cdecl) cdecl Nothing
makeAliasedCompType :: Ident -> CHSTypedefInfo -> GB ExtType
makeAliasedCompType cIde (hsIde, et) = do
return $ PrimET $
CAliasedPT (identToString cIde) (identToString hsIde) et
--
-- handle all types, which are not obviously pointers or functions
--
aliasOrSpecType :: Maybe CExpr -> GB ExtType
aliasOrSpecType sz = do
traceAliasOrSpecType sz
case checkForOneAliasName cdecl of
Nothing -> specType (posOf cdecl) specs' sz
Just ide -> do -- this is a typedef alias
oDefault <- queryTypedef ide
case oDefault of
Just tdefault -> makeAliasedCompType ide tdefault
Nothing -> do
traceAlias ide
oHsRepr <- queryPtr (False, ide) -- check for pointer hook alias
case oHsRepr of
Just repr | usePtrAliases
-> ptrAlias repr -- found a pointer hook alias
_ -> do -- skip current alias (only one)
cdecl' <- getDeclOf ide
let CDecl specs [(declr, init', _)] at =
ide `simplifyDecl` cdecl'
sdecl = CDecl specs [(declr, init', sz)] at
-- propagate `sz' down (slightly kludgy)
extractCompType isResult usePtrAliases False sdecl
--
-- compute the result for a pointer alias
--
ptrAlias (repr1, repr2) =
return $ DefinedET cdecl (if isResult then repr2 else repr1)
--
tracePtrType = traceGenBind $ "extractCompType: explicit pointer type\n"
traceFunType = traceGenBind $ "extractCompType: explicit function type\n"
traceAliasOrSpecType Nothing = traceGenBind $
"extractCompType: checking for alias\n"
traceAliasOrSpecType (Just _) = traceGenBind $
"extractCompType: checking for alias of bitfield\n"
traceAlias ide = traceGenBind $
"extractCompType: found an alias called `" ++ identToString ide ++ "'\n"
-- | C to Haskell type mapping described in the DOCU section
--
typeMap :: [([CTypeSpec], ExtType)]
typeMap = [([void] , UnitET ),
([char] , PrimET CCharPT ),
([unsigned, char] , PrimET CUCharPT ),
([signed, char] , PrimET CSCharPT ),
([signed] , PrimET CIntPT ),
([int] , PrimET CIntPT ),
([signed, int] , PrimET CIntPT ),
([short] , PrimET CShortPT ),
([short, int] , PrimET CShortPT ),
([signed, short] , PrimET CShortPT ),
([signed, short, int] , PrimET CShortPT ),
([long] , PrimET CLongPT ),
([long, int] , PrimET CLongPT ),
([signed, long] , PrimET CLongPT ),
([signed, long, int] , PrimET CLongPT ),
([long, long] , PrimET CLLongPT ),
([long, long, int] , PrimET CLLongPT ),
([signed, long, long] , PrimET CLLongPT ),
([signed, long, long, int] , PrimET CLLongPT ),
([unsigned] , PrimET CUIntPT ),
([unsigned, int] , PrimET CUIntPT ),
([unsigned, short] , PrimET CUShortPT ),
([unsigned, short, int] , PrimET CUShortPT ),
([unsigned, long] , PrimET CULongPT ),
([unsigned, long, int] , PrimET CULongPT ),
([unsigned, long, long] , PrimET CULLongPT ),
([unsigned, long, long, int] , PrimET CULLongPT ),
([float] , PrimET CFloatPT ),
([double] , PrimET CDoublePT ),
([bool] , PrimET CBoolPT ),
([long, double] , PrimET CLDoublePT),
([enum] , PrimET CIntPT )]
where
void = CVoidType undefined
char = CCharType undefined
short = CShortType undefined
int = CIntType undefined
long = CLongType undefined
float = CFloatType undefined
double = CDoubleType undefined
bool = CBoolType undefined
signed = CSignedType undefined
unsigned = CUnsigType undefined
enum = CEnumType undefined undefined
convertVarTypes :: String -> Position -> [String] -> GB [ExtType]
convertVarTypes base pos ts = do
let vaIdent i = internalIdent $ "__c2hs__vararg__" ++ base ++ "_" ++ show i
ides = map vaIdent [0..length ts - 1]
doone ide = do
Just (ObjCO cdecl) <- findObj ide
return cdecl
cdecls <- mapM doone ides
forM cdecls $ \cdecl -> do
st <- extractCompType True True False cdecl
case st of
SUET _ -> variadicTypeErr pos
_ -> return st
-- | compute the complex (external) type determined by a list of type specifiers
--
-- * may not be called for a specifier that defines a typedef alias
--
specType :: Position -> [CDeclSpec] -> Maybe CExpr -> GB ExtType
specType cpos specs'' osize =
let tspecs = [ts | CTypeSpec ts <- specs'']
in case lookupTSpec tspecs typeMap of
Just et | isUnsupportedType et -> unsupportedTypeSpecErr cpos
| isNothing osize -> return et -- not a bitfield
| otherwise -> bitfieldSpec tspecs et osize -- bitfield
Nothing ->
case tspecs of
[CSUType cu _] -> return $ SUET cu -- struct or union
[CEnumType _ _] -> return $ PrimET CIntPT -- enum
[CTypeDef _ _] -> errorAtPos cpos ["GenBind.specType: Illegal typedef alias!"]
_ -> illegalTypeSpecErr cpos
where
lookupTSpec = lookupBy matches
--
-- can't be a bitfield (yet)
isUnsupportedType (PrimET et) = et /= CBoolPT && size et == 0
isUnsupportedType _ = False
--
-- check whether two type specifier lists denote the same type; handles
-- types like `long long' correctly, as `deleteBy' removes only the first
-- occurrence of the given element
--
matches :: [CTypeSpec] -> [CTypeSpec] -> Bool
[] `matches` [] = True
[] `matches` (_:_) = False
(spec:specs) `matches` specs'
| any (eqSpec spec) specs' = specs `matches` deleteBy eqSpec spec specs'
| otherwise = False
--
eqSpec (CVoidType _) (CVoidType _) = True
eqSpec (CCharType _) (CCharType _) = True
eqSpec (CShortType _) (CShortType _) = True
eqSpec (CIntType _) (CIntType _) = True
eqSpec (CLongType _) (CLongType _) = True
eqSpec (CFloatType _) (CFloatType _) = True
eqSpec (CDoubleType _) (CDoubleType _) = True
eqSpec (CBoolType _) (CBoolType _) = True
eqSpec (CSignedType _) (CSignedType _) = True
eqSpec (CUnsigType _) (CUnsigType _) = True
eqSpec (CSUType _ _) (CSUType _ _) = True
eqSpec (CEnumType _ _) (CEnumType _ _) = True
eqSpec (CTypeDef _ _) (CTypeDef _ _) = True
eqSpec _ _ = False
--
bitfieldSpec :: [CTypeSpec] -> ExtType -> Maybe CExpr -> GB ExtType
bitfieldSpec tspecs et (Just sizeExpr) = -- never called with 'Nothing'
do
PlatformSpec {bitfieldIntSignedPS = bitfieldIntSigned} <- getPlatform
let pos = posOf sizeExpr
sizeResult <- evalConstCExpr sizeExpr
case sizeResult of
FloatResult _ -> illegalConstExprErr pos "a float result"
IntResult size' -> do
let sz = fromInteger size'
case et of
PrimET CUIntPT -> returnCT $ CUFieldPT sz
PrimET CIntPT
| [signed] `matches` tspecs
|| [signed, int] `matches` tspecs -> returnCT $ CSFieldPT sz
| [int] `matches` tspecs ->
returnCT $ if bitfieldIntSigned then CSFieldPT sz
else CUFieldPT sz
_ -> illegalFieldSizeErr pos
where
returnCT = return . PrimET
--
int = CIntType undefined
signed = CSignedType undefined
-- handle calling convention
-- -------------------------
data CallingConvention = StdCallConv
| CCallConv
deriving (Eq)
-- | determine the calling convention for the provided decl
extractCallingConvention :: CDecl -> CallingConvention
extractCallingConvention cdecl
| hasStdCallAttr cdecl = StdCallConv
| otherwise = CCallConv
where
isStdCallAttr (CAttr x _ _) = identToString x == "stdcall"
|| identToString x == "__stdcall__"
hasStdCallAttr = any isStdCallAttr . funAttrs
funAttrs (CDecl specs declrs _) =
let (_,attrs',_,_,_,_) = partitionDeclSpecs specs
in attrs' ++ funEndAttrs declrs ++ funPtrAttrs declrs
-- attrs after the function name, e.g. void foo() __attribute__((...));
funEndAttrs [(Just ((CDeclr _ (CFunDeclr _ _ _ : _) _ attrs _)), _, _)] =
attrs
funEndAttrs _ = []
-- attrs appearing within the declarator of a function pointer. As an
-- example:
-- typedef int (__stdcall *fp)();
funPtrAttrs [(Just ((CDeclr _ (CPtrDeclr _ _ :
CFunDeclr _ attrs _ : _) _ _ _)), _, _)] =
attrs
funPtrAttrs _ = []
-- | generate the necessary parameter for "foreign import" for the
-- provided calling convention
showCallingConvention :: CallingConvention -> String
showCallingConvention StdCallConv = "stdcall"
showCallingConvention CCallConv = "ccall"
-- offset and size computations
-- ----------------------------
-- | precise size representation
--
-- * this is a pair of a number of octets and a number of bits
--
-- * if the number of bits is nonzero, the octet component is aligned by the
-- alignment constraint for 'CIntPT' (important for accessing bitfields with
-- more than 8 bits)
--
data BitSize = BitSize Int Int
deriving (Eq, Show)
-- | ordering relation compares in terms of required storage units
--
instance Ord BitSize where
bs1@(BitSize o1 b1) < bs2@(BitSize o2 b2) =
padBits bs1 < padBits bs2 || (o1 == o2 && b1 < b2)
bs1 <= bs2 = bs1 < bs2 || bs1 == bs2
-- the <= instance is needed for Ord's compare functions, which is used in
-- the defaults for all other members
-- | add two bit size values
--
addBitSize :: BitSize -> BitSize -> BitSize
addBitSize (BitSize o1 b1) (BitSize o2 b2) =
BitSize (o1 + o2 + overflow * size CIntPT) rest
where
bitsPerBitfield = size CIntPT * 8
(overflow, rest) = (b1 + b2) `divMod` bitsPerBitfield
-- | multiply a bit size by a constant (gives size of an array)
--
-- * not sure if this makes sense if the number of bits is non-zero.
--
scaleBitSize :: Int -> BitSize -> BitSize
scaleBitSize n (BitSize o1 b1) = BitSize (n * o1 + overflow) rest
where
bitsPerBitfield = size CIntPT * 8
(overflow, rest) = (n * b1) `divMod` bitsPerBitfield
-- | pad any storage unit that is partially used by a bitfield
--
padBits :: BitSize -> Int
padBits (BitSize o 0) = o
padBits (BitSize o _) = o + size CIntPT
-- | compute the offset of the declarator in the second argument when it is
-- preceded by the declarators in the first argument
--
offsetInStruct :: [CDecl] -> CDecl -> CStructTag -> GB BitSize
offsetInStruct [] _ _ = return $ BitSize 0 0
offsetInStruct decls decl tag =
do
PlatformSpec {bitfieldAlignmentPS = bitfieldAlignment} <- getPlatform
(offset, _) <- sizeAlignOfStruct decls tag
(_, align) <- sizeAlignOf decl
return $ alignOffset offset align bitfieldAlignment
-- | compute the size and alignment (no padding at the end) of a set of
-- declarators from a struct
--
sizeAlignOfStruct :: [CDecl] -> CStructTag -> GB (BitSize, Int)
sizeAlignOfStruct [] _ = return (BitSize 0 0, 1)
sizeAlignOfStruct decls CStructTag =
do
PlatformSpec {bitfieldAlignmentPS = bitfieldAlignment} <- getPlatform
(offset, preAlign) <- sizeAlignOfStruct (init decls) CStructTag
(sz, align) <- sizeAlignOf (last decls)
let sizeOfStruct = alignOffset offset align bitfieldAlignment
`addBitSize` sz
align' = if align > 0 then align else bitfieldAlignment
alignOfStruct = preAlign `max` align'
return (sizeOfStruct, alignOfStruct)
sizeAlignOfStruct decls CUnionTag =
do
PlatformSpec {bitfieldAlignmentPS = bitfieldAlignment} <- getPlatform
(sizes, aligns) <- mapAndUnzipM sizeAlignOf decls
let aligns' = [if align > 0 then align else bitfieldAlignment
| align <- aligns]
return (maximum sizes, maximum aligns')
-- | compute the size and alignment of the declarators forming a struct
-- including any end-of-struct padding that is needed to make the struct ``tile
-- in an array'' (K&R A7.4.8)
--
sizeAlignOfStructPad :: [CDecl] -> CStructTag -> GB (BitSize, Int)
sizeAlignOfStructPad decls tag =
do
(sz, align) <- sizeAlignOfStruct decls tag
let b = size CIntPT
return (alignOffset sz (align `max` b) b, align)
-- | compute the size and alignment constraint of a given C declaration
--
sizeAlignOf :: CDecl -> GB (BitSize, Int)
sizeAlignOfPtr :: CDecl -> GB (BitSize, Int)
sizeAlignOfBase :: Bool -> CDecl -> GB (BitSize, Int)
sizeAlignOfSingle :: Bool -> CDecl -> GB (BitSize, Int)
--
-- * we make use of the assertion that 'extractCompType' can only return a
-- 'DefinedET' when the declaration is a pointer declaration
-- * for arrays, alignment is the same as for the base type and the size
-- is the size of the base type multiplied by the number of elements.
-- FIXME: I'm not sure whether anything of this is guaranteed by ISO C
-- and I have no idea what happens when an array-of-bitfield is
-- declared. At this time I don't care. -- U.S. 05/2006
--
sizeAlignOf = sizeAlignOfBase False
sizeAlignOfPtr = sizeAlignOfBase True
sizeAlignOfBase _ (CDecl dclspec
[(Just (CDeclr oide (CArrDeclr _ (CArrSize _ lexpr) _ :
derived') _asm _ats n), init', expr)]
attr) =
do
(bitsize, align) <-
sizeAlignOf (CDecl dclspec
[(Just (CDeclr oide derived' Nothing [] n), init', expr)]
attr)
IntResult len <- evalConstCExpr lexpr
return (fromIntegral len `scaleBitSize` bitsize, align)
sizeAlignOfBase _ cdecl@(CDecl _ [(Just (CDeclr _ (CArrDeclr _ (CNoArrSize _) _ :
_) _ _ _), _init, _expr)] _) =
errorAtPos (posOf cdecl) ["GenBind.sizeAlignOf: array of undeclared size."]
sizeAlignOfBase ptr cdecl = do
traceAliasCheck
case checkForOneAliasName cdecl of
Nothing -> sizeAlignOfSingle ptr cdecl
Just ide -> do -- this is a typedef alias
traceAlias ide
cdecl' <- getDeclOf ide
let CDecl specs [(declr, init', _)] at = ide `simplifyDecl` cdecl'
sdecl = CDecl specs [(declr, init', Nothing)] at
sizeAlignOf sdecl
where
traceAliasCheck = traceGenBind $ "extractCompType: checking for alias\n"
traceAlias ide = traceGenBind $
"extractCompType: found an alias called `" ++ identToString ide ++ "'\n"
checkForIncomplete :: CDecl -> GB ()
checkForIncomplete cdecl = do
ct <- extractCompType False False False cdecl
case ct of
SUET su -> do
let (fields, _) = structMembers su
ide = structName su
if (not . null $ fields) || isNothing ide
then return ()
else do -- get the real...
tag' <- findTag (fromJust ide) -- ...definition
case tag' of
Just (StructUnionCT (CStruct _ _ Nothing _ _)) ->
incompleteTypeErr $ posOf cdecl
_ -> return ()
_ -> return ()
sizeAlignOfSingle ptr cdecl = do
ct <- extractCompType False False False cdecl
case ct of
FunET _ _ -> do
align <- alignment CFunPtrPT
return (bitSize CFunPtrPT, align)
VarFunET _ -> do
align <- alignment CFunPtrPT
return (bitSize CFunPtrPT, align)
IOET _ -> errorAtPos (posOf cdecl) ["GenBind.sizeof: Illegal IO type!"]
PtrET t
| isFunExtType t -> do
align <- alignment CFunPtrPT
return (bitSize CFunPtrPT, align)
| otherwise -> do
align <- alignment CPtrPT
return (bitSize CPtrPT, align)
DefinedET _ _ ->
errorAtPos (posOf cdecl) ["GenBind.sizeAlignOf: Should never get a defined type"]
PrimET pt -> do
align <- alignment pt
return (bitSize pt, align)
UnitET -> if ptr
then do
align <- alignment CPtrPT
return (bitSize CPtrPT, align)
else voidFieldErr (posOf cdecl)
SUET su -> do
let (fields, tag) = structMembers su
fields' <- let ide = structName su
in if (not . null $ fields) || isNothing ide
then return fields
else do -- get the real...
tag' <- findTag (fromJust ide) -- ...definition
case tag' of
Just (StructUnionCT su') -> return
(fst . structMembers $ su')
_ -> return fields
sizeAlignOfStructPad fields' tag
where
bitSize et | sz < 0 = BitSize 0 (-sz) -- size is in bits
| otherwise = BitSize sz 0
where
sz = size et
-- | apply the given alignment constraint at the given offset
--
-- * if the alignment constraint is negative or zero, it is the alignment
-- constraint for a bitfield
--
-- * the third argument gives the platform-specific bitfield alignment
--
alignOffset :: BitSize -> Int -> Int -> BitSize
alignOffset offset@(BitSize octetOffset bitOffset) align bitfieldAlignment
| align > 0 && bitOffset /= 0 = -- close bitfield first
alignOffset (BitSize (octetOffset + (bitOffset + 7) `div` 8) 0) align
bitfieldAlignment
| align > 0 && bitOffset == 0 = -- no bitfields involved
BitSize (((octetOffset - 1) `div` align + 1) * align) 0
| bitOffset == 0 -- start a bitfield
|| overflowingBitfield = -- .. or overflowing bitfield
alignOffset offset bitfieldAlignment bitfieldAlignment
| otherwise = -- stays in current bitfield
offset
where
bitsPerBitfield = size CIntPT * 8
overflowingBitfield = bitOffset - align > bitsPerBitfield
-- note, `align' is negative
-- constant folding
-- ----------------
-- | evaluate a constant expression
--
-- FIXME: this is a bit too simplistic, as the range of expression allowed as
-- constant expression varies depending on the context in which the
-- constant expression occurs
--
evalConstCExpr :: CExpr -> GB ConstResult
evalConstCExpr (CComma _ at) =
illegalConstExprErr (posOf at) "a comma expression"
evalConstCExpr (CAssign _ _ _ at) =
illegalConstExprErr (posOf at) "an assignment"
evalConstCExpr (CCond b (Just t) e _) =
do
bv <- evalConstCExpr b
case bv of
IntResult bvi -> if bvi /= 0 then evalConstCExpr t else evalConstCExpr e
FloatResult _ -> illegalConstExprErr (posOf b) "a float result"
evalConstCExpr (CBinary op lhs rhs at) =
do
lhsVal <- evalConstCExpr lhs
rhsVal <- evalConstCExpr rhs
let (lhsVal', rhsVal') = usualArithConv lhsVal rhsVal
applyBin (posOf at) op lhsVal' rhsVal'
evalConstCExpr c@(CCast _ _ _) =
evalCCast c
evalConstCExpr (CUnary op arg at) =
do
argVal <- evalConstCExpr arg
applyUnary (posOf at) op argVal
evalConstCExpr (CSizeofExpr _ _) =
todo "GenBind.evalConstCExpr: sizeof not implemented yet."
evalConstCExpr (CSizeofType decl _) =
do
(sz, _) <- sizeAlignOf decl
return $ IntResult (fromIntegral . padBits $ sz)
evalConstCExpr (CAlignofExpr _ _) =
todo "GenBind.evalConstCExpr: alignof (GNU C extension) not implemented yet."
evalConstCExpr (CAlignofType decl _) =
do
(_, align) <- sizeAlignOf decl
return $ IntResult (fromIntegral align)
evalConstCExpr (CIndex _ _ at) =
illegalConstExprErr (posOf at) "array indexing"
evalConstCExpr (CCall _ _ at) =
illegalConstExprErr (posOf at) "function call"
evalConstCExpr (CMember _ _ _ at) =
illegalConstExprErr (posOf at) "a . or -> operator"
evalConstCExpr cdecl@(CVar ide''' at) =
do
(cobj, _) <- findValueObj ide''' False
case cobj of
EnumCO ide'' (CEnum _ (Just enumrs) _ _) ->
liftM IntResult $ enumTagValue ide'' enumrs 0
_ ->
todo $ "GenBind.evalConstCExpr: variable names not implemented yet " ++
show (posOf at)
where
-- FIXME: this is not very nice; instead, CTrav should have some support
-- for determining enum tag values (but then, constant folding needs
-- to be moved to CTrav, too)
--
-- Compute the tag value for `ide' defined in the given enumerator list
--
enumTagValue _ [] _ =
errorAtPos (posOf cdecl) ["GenBind.enumTagValue: enumerator not in declaration"]
enumTagValue ide ((ide', oexpr):enumrs) val =
do
val' <- case oexpr of
Nothing -> return val
Just exp ->
do
val' <- evalConstCExpr exp
case val' of
IntResult val'' -> return val''
FloatResult _ ->
illegalConstExprErr (posOf exp) "a float result"
if ide == ide'
then -- found the right enumerator
return val'
else -- continue down the enumerator list
enumTagValue ide enumrs (val' + 1)
evalConstCExpr (CConst c) = evalCConst c
evalCCast :: CExpr -> GB ConstResult
evalCCast (CCast decl expr _) = do
compType <- extractCompType False False False decl
evalCCast' compType (getConstInt expr)
where
getConstInt (CConst (CIntConst (CInteger i _ _) _)) = i
getConstInt _ = todo $ "GenBind.evalCCast: Casts are implemented " ++
"only for integral constants"
evalCCast' :: ExtType -> Integer -> GB ConstResult
evalCCast' (PrimET primType) i
| isIntegralCPrimType primType = return $ IntResult i
evalCCast' _ _ = todo $ "GenBind.evalCCast': Only integral trivial " ++
"casts are implemented"
evalCConst :: CConst -> GB ConstResult
evalCConst (CIntConst i _ ) = return $ IntResult (getCInteger i)
evalCConst (CCharConst c@(C2HS.C.CChar _ _) _ ) =
return $ IntResult (getCCharAsInt c)
evalCConst (CCharConst (CChars cs _) _ ) = return $ IntResult (foldl' add 0 cs)
where add tot ch = tot * 0x100 + fromIntegral (fromEnum ch)
evalCConst (CFloatConst _ _ ) =
todo "GenBind.evalCConst: Float conversion from literal misses."
evalCConst (CStrConst _ at) =
illegalConstExprErr (posOf at) "a string constant"
usualArithConv :: ConstResult -> ConstResult -> (ConstResult, ConstResult)
usualArithConv lhs@(FloatResult _) rhs = (lhs, toFloat rhs)
usualArithConv lhs rhs@(FloatResult _) = (toFloat lhs, rhs)
usualArithConv lhs rhs = (lhs, rhs)
toFloat :: ConstResult -> ConstResult
toFloat x@(FloatResult _) = x
toFloat (IntResult i) = FloatResult . fromIntegral $ i
applyBin :: Position
-> CBinaryOp
-> ConstResult
-> ConstResult
-> GB ConstResult
applyBin _ CMulOp (IntResult x)
(IntResult y) = return $ IntResult (x * y)
applyBin _ CMulOp (FloatResult x)
(FloatResult y) = return $ FloatResult (x * y)
applyBin _ CDivOp (IntResult x)
(IntResult y) = return $ IntResult (x `div` y)
applyBin _ CDivOp (FloatResult x)
(FloatResult y) = return $ FloatResult (x / y)
applyBin _ CRmdOp (IntResult x)
(IntResult y) = return$ IntResult (x `mod` y)
applyBin cpos CRmdOp (FloatResult _)
(FloatResult _) =
illegalConstExprErr cpos "a % operator applied to a float"
applyBin _ CAddOp (IntResult x)
(IntResult y) = return $ IntResult (x + y)
applyBin _ CAddOp (FloatResult x)
(FloatResult y) = return $ FloatResult (x + y)
applyBin _ CSubOp (IntResult x)
(IntResult y) = return $ IntResult (x - y)
applyBin _ CSubOp (FloatResult x)
(FloatResult y) = return $ FloatResult (x - y)
applyBin _ CShlOp (IntResult x)
(IntResult y) = return $ IntResult (x * 2^y)
applyBin cpos CShlOp (FloatResult _)
(FloatResult _) =
illegalConstExprErr cpos "a << operator applied to a float"
applyBin _ CShrOp (IntResult x)
(IntResult y) = return $ IntResult (x `div` 2^y)
applyBin cpos CShrOp (FloatResult _)
(FloatResult _) =
illegalConstExprErr cpos "a >> operator applied to a float"
applyBin _ COrOp (IntResult x)
(IntResult y) = return $ IntResult (x .|. y)
applyBin _ CAndOp (IntResult x)
(IntResult y) = return $ IntResult (x .&. y)
applyBin pos _ (IntResult _)
(IntResult _) =
todo $ "GenBind.applyBin: Not yet implemented operator in constant expression. " ++ show pos
applyBin pos _ (FloatResult _)
(FloatResult _) =
todo $ "GenBind.applyBin: Not yet implemented operator in constant expression. " ++ show pos
applyBin pos _ _ _ =
errorAtPos pos ["GenBind.applyBinOp: Illegal combination!"]
applyUnary :: Position -> CUnaryOp -> ConstResult -> GB ConstResult
applyUnary cpos CPreIncOp _ =
illegalConstExprErr cpos "a ++ operator"
applyUnary cpos CPreDecOp _ =
illegalConstExprErr cpos "a -- operator"
applyUnary cpos CPostIncOp _ =
illegalConstExprErr cpos "a ++ operator"
applyUnary cpos CPostDecOp _ =
illegalConstExprErr cpos "a -- operator"
applyUnary cpos CAdrOp _ =
illegalConstExprErr cpos "a & operator"
applyUnary cpos CIndOp _ =
illegalConstExprErr cpos "a * operator"
applyUnary _ CPlusOp arg = return arg
applyUnary _ CMinOp (IntResult x) = return (IntResult (-x))
applyUnary _ CMinOp (FloatResult x) = return (FloatResult (-x))
applyUnary pos CCompOp _ =
todo $ "GenBind.applyUnary: ~ not yet implemented. " ++ show pos
applyUnary _ CNegOp (IntResult x) =
let r = toInteger . fromEnum $ (x == 0)
in return (IntResult r)
applyUnary cpos CNegOp (FloatResult _) =
illegalConstExprErr cpos "! applied to a float"
-- auxilliary functions
-- --------------------
-- | print trace message
--
traceGenBind :: String -> GB ()
traceGenBind = putTraceStr traceGenBindSW
-- | generic lookup
--
lookupBy :: (a -> a -> Bool) -> a -> [(a, b)] -> Maybe b
lookupBy eq x = fmap snd . find (eq x . fst)
-- error messages
-- --------------
unknownFieldErr :: Position -> Ident -> GB a
unknownFieldErr cpos ide =
raiseErrorCTExc (posOf ide)
["Unknown member name!",
"The structure has no member called `" ++ identToString ide
++ "'. The structure is defined at",
show cpos ++ "."]
illegalTypeSpecErr :: Position -> GB a
illegalTypeSpecErr cpos =
raiseErrorCTExc cpos
["Illegal type!",
"The type specifiers of this declaration do not form a " ++
"legal ANSI C(89) type."
]
unsupportedTypeSpecErr :: Position -> GB a
unsupportedTypeSpecErr cpos =
raiseErrorCTExc cpos
["Unsupported type!",
"The type specifier of this declaration is not supported by your " ++
"combination of C compiler and Haskell compiler."
]
variadicErr :: Position -> Position -> GB a
variadicErr pos cpos =
raiseErrorCTExc pos
["Variadic function!",
"Calling variadic functions is not supported by the FFI; the function",
"is defined at " ++ show cpos ++ "."]
variadicTypeErr :: Position -> GB a
variadicTypeErr pos =
raiseErrorCTExc pos
["Variadic function argument type!",
"Calling variadic functions is only supported for simple C types"]
typeDefaultErr :: Position -> GB a
typeDefaultErr pos =
raiseErrorCTExc pos
["Internal type default error!",
"Something went wrong."]
illegalPlusErr :: Position -> GB a
illegalPlusErr pos =
raiseErrorCTExc pos
["Illegal plus parameter!",
"The special parameter `+' may only be used in a single input " ++
"parameter position in a function hook"]
illegalConstExprErr :: Position -> String -> GB a
illegalConstExprErr cpos hint =
raiseErrorCTExc cpos ["Illegal constant expression!",
"Encountered " ++ hint ++ " in a constant expression,",
"which ANSI C89 does not permit."]
voidFieldErr :: Position -> GB a
voidFieldErr cpos =
raiseErrorCTExc cpos ["Void field in struct!",
"Attempt to access a structure field of type void."]
structExpectedErr :: Ident -> GB a
structExpectedErr ide =
raiseErrorCTExc (posOf ide)
["Expected a structure or union!",
"Attempt to access member `" ++ identToString ide ++ "' in something not",
"a structure or union."]
ptrExpectedErr :: Position -> GB a
ptrExpectedErr pos =
raiseErrorCTExc pos
["Expected a pointer object!",
"Attempt to dereference a non-pointer object or to use it in a " ++
"`pointer' hook."]
funPtrExpectedErr :: Position -> GB a
funPtrExpectedErr pos =
raiseErrorCTExc pos
["Expected a pointer-to-function object!",
"Attempt to use a non-pointer object in a `call' or `fun' hook."]
illegalStablePtrErr :: Position -> GB a
illegalStablePtrErr pos =
raiseErrorCTExc pos
["Illegal use of a stable pointer!",
"Class hooks cannot be used for stable pointers."]
pointerTypeMismatchErr :: Position -> String -> String -> GB a
pointerTypeMismatchErr pos className superName =
raiseErrorCTExc pos
["Pointer type mismatch!",
"The pointer of the class hook for `" ++ className
++ "' is of a different kind",
"than that of the class hook for `" ++ superName ++ "'; this is illegal",
"as the latter is defined to be an (indirect) superclass of the former."]
illegalFieldSizeErr :: Position -> GB a
illegalFieldSizeErr cpos =
raiseErrorCTExc cpos
["Illegal field size!",
"Only signed and unsigned `int' types may have a size annotation."]
derefBitfieldErr :: Position -> GB a
derefBitfieldErr pos =
raiseErrorCTExc pos
["Illegal dereferencing of a bit field!",
"Bit fields cannot be dereferenced."]
offsetBitfieldErr :: Position -> GB a
offsetBitfieldErr pos =
raiseErrorCTExc pos ["Illegal offset of a bit field!",
"Bit fields do not necessarily lie " ++
"on a whole-byte boundary."]
offsetDerefErr :: Position -> GB a
offsetDerefErr pos =
raiseErrorCTExc pos ["Disallowed offset of using a dereference!",
"While calculable, it would almost certainly " ++
"be confusing to give the offset from the " ++
"beginning of a not-obviously-related struct"]
resMarshIllegalInErr :: Position -> GB a
resMarshIllegalInErr pos =
raiseErrorCTExc pos
["Malformed result marshalling!",
"An \"in\" marshaller is not allowed for the function result type.",
"Note that \"out\" marshallers are specified *after* the type, like:",
" {# fun ... -> `MyType' mkMyType #} "]
resMarshIllegalTwoCValErr :: Position -> GB a
resMarshIllegalTwoCValErr pos =
raiseErrorCTExc pos
["Malformed result marshalling!",
"Two C values (i.e., the `&' symbol) are not allowed for the result."]
marshArgMismatchErr :: Position -> String -> GB a
marshArgMismatchErr pos reason =
raiseErrorCTExc pos
["Function arity mismatch!",
reason]
noDftMarshErr :: Position -> String -> String -> [ExtType] -> GB a
noDftMarshErr pos inOut hsTy cTys =
raiseErrorCTExc pos
["Missing " ++ inOut ++ " marshaller!",
"There is no default marshaller for this combination of Haskell and " ++
"C type:",
"Haskell type: " ++ hsTy,
"C type : " ++ concat (intersperse " " (map showExtType cTys))]
undefEnumErr :: Position -> GB a
undefEnumErr pos = raiseErrorCTExc pos ["Incomplete enum type!"]
incompleteTypeErr :: Position -> GB a
incompleteTypeErr pos =
raiseErrorCTExc pos
["Illegal use of incomplete type!",
"Expected a fully defined structure or union tag; instead found incomplete type."]
-- | size of primitive type of C
--
-- * negative size implies that it is a bit, not an octet size
--
size :: CPrimType -> Int
size CPtrPT = Storable.sizeOf (undefined :: Ptr ())
size CFunPtrPT = Storable.sizeOf (undefined :: FunPtr ())
size CCharPT = 1
size CUCharPT = 1
size CSCharPT = 1
size CIntPT = Storable.sizeOf (undefined :: CInt)
size CShortPT = Storable.sizeOf (undefined :: CShort)
size CLongPT = Storable.sizeOf (undefined :: CLong)
size CLLongPT = Storable.sizeOf (undefined :: CLLong)
size CUIntPT = Storable.sizeOf (undefined :: CUInt)
size CUShortPT = Storable.sizeOf (undefined :: CUShort)
size CULongPT = Storable.sizeOf (undefined :: CULong)
size CULLongPT = Storable.sizeOf (undefined :: CLLong)
size CFloatPT = Storable.sizeOf (undefined :: Foreign.C.CFloat)
size CDoublePT = Storable.sizeOf (undefined :: CDouble)
#if MIN_VERSION_base(4,2,0)
size CLDoublePT = 0 --marks it as an unsupported type, see 'specType'
#else
size CLDoublePT = Storable.sizeOf (undefined :: CLDouble)
#endif
size CBoolPT = cBoolSize
size (CSFieldPT bs) = -bs
size (CUFieldPT bs) = -bs
size (CAliasedPT _ _ pt) = size pt
-- | alignment of C's primitive types
--
-- * more precisely, the padding put before the type's member starts when the
-- preceding component is a char
--
alignment :: CPrimType -> GB Int
alignment CPtrPT = return $ Storable.alignment (undefined :: Ptr ())
alignment CFunPtrPT = return $ Storable.alignment (undefined :: FunPtr ())
alignment CCharPT = return $ 1
alignment CUCharPT = return $ 1
alignment CSCharPT = return $ 1
alignment CIntPT = return $ Storable.alignment (undefined :: CInt)
alignment CShortPT = return $ Storable.alignment (undefined :: CShort)
alignment CLongPT = return $ Storable.alignment (undefined :: CLong)
alignment CLLongPT = return $ Storable.alignment (undefined :: CLLong)
alignment CUIntPT = return $ Storable.alignment (undefined :: CUInt)
alignment CUShortPT = return $ Storable.alignment (undefined :: CUShort)
alignment CULongPT = return $ Storable.alignment (undefined :: CULong)
alignment CULLongPT = return $ Storable.alignment (undefined :: CULLong)
alignment CFloatPT =
return $ Storable.alignment (undefined :: Foreign.C.CFloat)
alignment CDoublePT = return $ Storable.alignment (undefined :: CDouble)
#if MIN_VERSION_base(4,2,0)
alignment CLDoublePT = interr "Info.alignment: CLDouble not supported"
#else
alignment CLDoublePT = return $ Storable.alignment (undefined :: CLDouble)
#endif
alignment CBoolPT = return cBoolSize
alignment (CSFieldPT bs) = fieldAlignment bs
alignment (CUFieldPT bs) = fieldAlignment bs
alignment (CAliasedPT _ _ pt) = alignment pt
-- | alignment constraint for a C bitfield
--
-- * gets the bitfield size (in bits) as an argument
--
-- * alignments constraints smaller or equal to zero are reserved for bitfield
-- alignments
--
-- * bitfields of size 0 always trigger padding; thus, they get the maximal
-- size
--
-- * if bitfields whose size exceeds the space that is still available in a
-- partially filled storage unit trigger padding, the size of a storage unit
-- is provided as the alignment constraint; otherwise, it is 0 (meaning it
-- definitely starts at the current position)
--
-- * here, alignment constraint /= 0 are somewhat subtle; they mean that is
-- the given number of bits doesn't fit in what's left in the current
-- storage unit, alignment to the start of the next storage unit has to be
-- triggered
--
fieldAlignment :: Int -> GB Int
fieldAlignment 0 = return $ - (size CIntPT - 1)
fieldAlignment bs =
do
PlatformSpec {bitfieldPaddingPS = bitfieldPadding} <- getPlatform
return $ if bitfieldPadding then - bs else 0
-- | obtain platform from switchboard
--
getPlatform :: GB PlatformSpec
getPlatform = getSwitch platformSB
-- All this is slightly horrible, but it's the only way to find the
-- size of the C99 _Bool type which is needed for marshalling
-- structures containing C 'bool' values. (Marshalling of 'bool'
-- function arguments and return values can be done by passing them
-- through the FFI as C 'int', but calculating offsets into structures
-- requires knowledge of the size of the type, which isn't provided by
-- the Haskell FFI.)
{-# NOINLINE cBoolSizeRef #-}
cBoolSizeRef :: IORef (Maybe Int)
cBoolSizeRef = unsafePerformIO $ newIORef Nothing
findBoolSize :: IO Int
findBoolSize = do
withFile "c2hs__bool_size.c" WriteMode $ \h -> do
hPutStrLn h "#include <stdio.h>"
hPutStrLn h $ "int main(int argc, char *argv[]) " ++
"{ printf(\"%u\\n\", sizeof(_Bool)); return 0; }"
gcccode <- system $ cCompiler ++ " -o c2hs__bool_size c2hs__bool_size.c"
when (gcccode /= ExitSuccess) $
error "Failed to compile 'bool' size test program!"
(code, stdout, _) <- readProcessWithExitCode "./c2hs__bool_size" [] ""
when (code /= ExitSuccess) $
error "Failed to run 'bool' size test program!"
let sz = read stdout :: Int
removeFile "c2hs__bool_size.c"
removeFile "c2hs__bool_size"
return sz
cBoolSize :: Int
cBoolSize = unsafePerformIO $ do
msz <- readIORef cBoolSizeRef
case msz of
Just sz -> return sz
Nothing -> do
sz <- findBoolSize
writeIORef cBoolSizeRef $ Just sz
return sz
{-# NOINLINE cCompilerRef #-}
cCompilerRef :: IORef (Maybe String)
cCompilerRef = unsafePerformIO $ newIORef Nothing
cCompiler :: String
cCompiler = unsafePerformIO $ do
mcc <- readIORef cCompilerRef
case mcc of
Just cc -> return cc
Nothing -> do
(code, stdout, _) <- readProcessWithExitCode "ghc" ["--info"] ""
when (code /= ExitSuccess) $
error "Failed to determine C compiler from 'ghc --info'!"
let vals = read stdout :: [(String, String)]
case Prelude.lookup "C compiler command" vals of
Nothing -> error "Failed to determine C compiler from 'ghc --info'!"
Just cc -> do
writeIORef cCompilerRef $ Just cc
return cc