c2hsc-0.1.0: Main.hs
module Main where
import Control.Applicative
import Control.Monad hiding (sequence)
import Control.Monad.Trans.State
import Data.Char
import Data.Foldable
import Data.List hiding (concat)
import qualified Data.Map as M
import Data.Maybe
import Data.Traversable
import Language.C.Data.Ident
import Language.C.Data.InputStream
import Language.C.Data.Node
import Language.C.Data.Position
import Language.C.Parser
import Language.C.Pretty
import Language.C.Syntax.AST
import Language.C.System.GCC
import Language.C.System.Preprocess
import Prelude hiding (concat, sequence)
import System.Directory
import System.Environment
import System.FilePath
import System.IO
import Text.PrettyPrint as P
import Text.StringTemplate
------------------------------ IMPURE FUNCTIONS ------------------------------
-- Parsing of C headers begins with finding gcc so we can run the
-- preprocessor.
main :: IO ()
main = do
gccExe <- findExecutable "gcc"
case gccExe of
Nothing -> error "Cannot find 'gcc' executable on the PATH"
Just gccPath -> getArgs >>= parseFile gccPath
-- Once gcc is found, setup to parse the C file by running the preprocessor.
-- Then, identify the input file absolutely so we know which declarations to
-- print out at the end.
parseFile :: FilePath -> [String] -> IO ()
parseFile gccPath args = do
fileName <- canonicalizePath $ last args
result <- runPreprocessor (newGCC gccPath)
(rawCppArgs (tail . init $ args) fileName)
case result of
Left err -> error $ "Failed to run cpp: " ++ show err
Right stream -> do
let HscOutput hscs helpercs _ =
execState (parseCFile stream fileName (initPos fileName))
newHscState
writeProducts (head args) fileName hscs helpercs
-- Write out the gathered data
writeProducts :: String -> FilePath -> [String] -> [String] -> IO ()
writeProducts libName fileName hscs helpercs = do
let tmpl = unlines [ "#include <bindings.dsl.h>"
, "#include <git2.h>"
, "module $libName$.$cFileName$ where"
, "#strict_import"
, "" ]
vars = [ ("libName", libName)
, ("cFileName", cap) ]
code = newSTMP tmpl
base = dropExtension . takeFileName $ fileName
cap = capitalize base
let target = cap ++ ".hsc"
handle <- openFile target WriteMode
hPutStrLn handle $ toString $ setManyAttrib vars code
-- Sniff through the file again, but looking only for local #include's
contents <- readFile fileName
let includes = filter ("#include \"" `isPrefixOf`) (lines contents)
for_ includes $ \inc ->
hPutStrLn handle $ "import "
++ libName ++ "."
++ (capitalize . takeWhile (/= '.') . drop 10 $ inc)
traverse_ (hPutStrLn handle) hscs
hClose handle
putStrLn $ "Wrote " ++ target
when (length helpercs > 0) $ do
let targetc = cap ++ ".hsc.helper.c"
handlec <- openFile targetc WriteMode
hPutStrLn handlec "#include <bindings.cmacros.h>"
traverse_ (hPutStrLn handlec) includes
hPutStrLn handlec ""
traverse_ (hPutStrLn handlec) helpercs
hClose handlec
putStrLn $ "Wrote " ++ targetc
where capitalize [] = []
capitalize (x:xs) = toTitle x : xs
------------------------------- PURE FUNCTIONS -------------------------------
-- Rather than writing to the .hsc and .hsc.helper.c files directly from the
-- IO monad, they are collected in an HscOutput value in the State monad. The
-- actual writing is done by writeProducts. This keeps all the code below
-- pure, and since the data sets involved are relatively small, performance is
-- not a critical issue.
type TypeMap = M.Map String String
data HscOutput = HscOutput [String] [String] TypeMap
type Output = State HscOutput
newHscState :: HscOutput
newHscState = HscOutput [] [] M.empty
appendHsc :: String -> Output ()
appendHsc hsc = do
HscOutput hscs xs types <- get
put $ HscOutput (hscs ++ [hsc]) xs types
appendHelper :: String -> Output ()
appendHelper helperc = do
HscOutput xs helpercs types <- get
put $ HscOutput xs (helpercs ++ [helperc]) types
defineType :: String -> String -> Output ()
defineType key value = do
HscOutput xs ys types <- get
put $ HscOutput xs ys (M.insert key value types)
lookupType :: String -> Output (Maybe String)
lookupType key = do
HscOutput _ _ types <- get
return $ M.lookup key types
-- Now we are ready to parse the C code from the preprocessed input stream,
-- located in the given file and starting at the specified position. The
-- result of a parse is a list of global declarations, so filter the list down
-- to those occurring in the target file, and then print the declarations in
-- Bindings-DSL format.
parseCFile :: InputStream -> FilePath -> Position -> Output ()
parseCFile stream fileName pos =
case parseC stream pos of
Left err -> error $ "Failed to compile: " ++ show err
Right (CTranslUnit decls _) -> generateHsc decls
where
generateHsc :: [CExtDecl] -> Output ()
generateHsc = traverse_ (appendNode fileName)
declInFile :: FilePath -> CExtDecl -> Bool
declInFile fileName = (fileName ==) . infoFile . declInfo
infoFile :: NodeInfo -> String
infoFile = posFile . posOfNode
declInfo :: CExtDecl -> NodeInfo
declInfo (CDeclExt (CDecl _ _ info)) = info
declInfo (CFDefExt (CFunDef _ _ _ _ info)) = info
declInfo (CAsmExt _ info) = info
-- These are the top-level printing routines. We are only interested in
-- declarations and function defitions (which almost always means inline
-- functions if the target file is a header file).
--
-- We will end up printing the following constructs:
--
-- - Structure definitions
-- - Opaque types (i.e., forward declarations of pointer type)
-- - Enums
-- - Extern Functions
-- - Inline Functions
appendNode :: FilePath -> CExtDecl -> Output ()
appendNode fp dx@(CDeclExt (CDecl declSpecs items _)) =
for_ items $ \(declrtr, _, _) -> do
for_ (splitDecl declrtr) $ \(d, ddrs, name) ->
case ddrs of
CFunDeclr (Right (_, _)) _ _ : _ ->
when (declInFile fp dx) $
appendFunc "#ccall" declSpecs d
_ -> do
when (declInFile fp dx) $ do
appendHsc $ "{- " ++ P.render (pretty dx) ++ " -}"
appendType declSpecs name
-- If the type is a typedef, record the equivalence so we can look
-- it up later
case head declSpecs of
CStorageSpec (CTypedef _) -> do
-- jww (2012-09-04): Types which are typedefs of functions
-- pointers are not working, since declSpecTypeName only gives
-- the function return type, not the function type
dname <- declSpecTypeName declSpecs
case dname of
"" -> return ()
_ -> defineType name dname
_ -> return ()
where splitDecl declrtr = do
-- Take advantage of the Maybe monad to save us some effort
d@(CDeclr ident ddrs _ _ _) <- declrtr
(Ident name _ _) <- ident
return (d, ddrs, name)
appendNode fp dx@(CFDefExt (CFunDef declSpecs declrtr _ _ _)) =
-- Assume functions defined in headers are inline functions
when (declInFile fp dx) $ do
appendFunc "#cinline" declSpecs declrtr
case declrtr of
(CDeclr ident ddrs _ _ _) ->
for_ ident $ \(Ident name _ _) ->
case head ddrs of
(CFunDeclr (Right (decls, _)) _ _) -> do
let argsList =
concat . intersperse ", " . map (P.render . pretty) $ decls
retType <- derDeclrTypeName' True declSpecs (tail ddrs)
if retType /= ""
then appendHelper $ "BC_INLINE" ++ show (length decls)
++ "(" ++ name ++ ", " ++ argsList
++ ", " ++ retType ++ ")"
else appendHelper $ "BC_INLINE" ++ show (length decls)
++ "VOID(" ++ name ++ ", " ++ argsList ++ ")"
_ -> return ()
appendNode _ (CAsmExt _ _) = return ()
-- Print out a function as #ccall or #cinline. The syntax is the same for
-- both externs and inlines, except that we want to do extra work for inline
-- and create a helper file with some additional macros.
appendFunc :: String -> [CDeclarationSpecifier a] -> CDeclarator a -> Output ()
appendFunc marker declSpecs (CDeclr ident ddrs _ _ _) = do
retType <- derDeclrTypeName declSpecs (tail ddrs)
argTypes <- sequence $ getArgTypes (head ddrs)
let name' = nameFromIdent ident
tmpl = "$marker$ $name$ , $argTypes;separator=' -> '$ -> IO ($retType$)"
code = newSTMP tmpl
-- I have to this separately since argTypes :: [String]
code' = setAttribute "argTypes" argTypes code
vars = [ ("marker", marker)
, ("name", name')
, ("retType", retType) ]
appendHsc $ toString $ setManyAttrib vars code'
where
getArgTypes (CFunDeclr (Right (decls, _)) _ _) = map cdeclTypeName decls
getArgTypes _ = []
nameFromIdent :: Maybe Ident -> String
nameFromIdent name = case name of
Just (Ident n _ _) -> n
_ -> "<no name>"
appendType :: [CDeclarationSpecifier a] -> String -> Output ()
appendType declSpecs declrName = traverse_ appendType' declSpecs
where
appendType' (CTypeSpec (CSUType (CStruct _ ident decls _ _) _)) = do
let name' = identName ident
when (isNothing decls) $
appendHsc $ "#opaque_t " ++ name'
for_ decls $ \xs -> do
appendHsc $ "#starttype " ++ name'
for_ xs $ \x ->
for_ (cdeclName x) $ \declName -> do
tname <- cdeclTypeName x
appendHsc $ "#field " ++ declName ++ " , " ++ tname
appendHsc "#stoptype"
appendType' (CTypeSpec (CEnumType (CEnum ident defs _ _) _)) = do
let name' = identName ident
appendHsc $ "#integral_t " ++ name'
for_ defs $ \ds ->
for_ ds $ \((Ident name _ _), _) -> do
appendHsc $ "#num " ++ name
appendType' _ = return ()
identName ident = case ident of
Nothing -> declrName
Just (Ident name _ _) -> name
-- The remainder of this file is some hairy code for turning various
-- constructs into Bindings-DSL type names, such as turning "int ** foo" into
-- the type name "Ptr (Ptr CInt)".
data Signedness = None | Signed | Unsigned deriving (Eq, Show, Enum)
cdeclName :: CDeclaration a -> Maybe String
cdeclName (CDecl _ more _) =
case more of
(Just (CDeclr (Just (Ident name _ _)) _ _ _ _), _, _) : _ -> Just name
_ -> Nothing
cdeclTypeName :: CDeclaration a -> Output String
cdeclTypeName (CDecl declSpecs more _) =
case more of
(Just x, _, _) : _ -> declrTypeName declSpecs x
_ -> declSpecTypeName declSpecs
declSpecTypeName :: [CDeclarationSpecifier a] -> Output String
declSpecTypeName = flip derDeclrTypeName []
declrTypeName :: [CDeclarationSpecifier a] -> CDeclarator a -> Output String
declrTypeName declSpecs (CDeclr _ ddrs _ _ _) = derDeclrTypeName declSpecs ddrs
derDeclrTypeName :: [CDeclarationSpecifier a] -> [CDerivedDeclarator a]
-> Output String
derDeclrTypeName = derDeclrTypeName' False
derDeclrTypeName' :: Bool -> [CDeclarationSpecifier a] -> [CDerivedDeclarator a]
-> Output String
derDeclrTypeName' cStyle declSpecs ddrs =
applyPointers <$> fullTypeName' None declSpecs <*> pure ddrs
where
fullTypeName' :: Signedness -> [CDeclarationSpecifier a] -> Output String
fullTypeName' _ [] = return ""
fullTypeName' s (x:xs) =
case x of
CTypeSpec (CSignedType _) -> fullTypeName' Signed xs
CTypeSpec (CUnsigType _) -> fullTypeName' Unsigned xs
CTypeSpec tspec -> if cStyle
then cTypeName tspec s
else typeName tspec s
_ -> fullTypeName' s xs
applyPointers :: String -> [CDerivedDeclarator a] -> String
applyPointers baseType [] = baseType
applyPointers baseType (x:[]) =
case x of
CPtrDeclr _ _ ->
if cStyle
then if baseType == ""
then "void *"
else baseType ++ " *"
else if baseType == ""
then "Ptr ()"
else "Ptr " ++ baseType
_ -> ""
applyPointers baseType (x:xs) =
case x of
CPtrDeclr _ _ ->
if cStyle
then applyPointers baseType xs ++ " *"
else "Ptr (" ++ applyPointers baseType xs ++ ")"
_ -> ""
-- Simple translation from C types to Foreign.C.Types types. We represent
-- Void as the empty string so that returning void becomes IO (), and passing
-- a void star becomes Ptr ().
typeName :: CTypeSpecifier a -> Signedness -> Output String
typeName (CVoidType _) _ = return $ ""
typeName (CFloatType _) _ = return $ "CFloat"
typeName (CDoubleType _) _ = return $ "CDouble"
typeName (CBoolType _) _ = return $ "CInt"
typeName (CCharType _) s = case s of
Signed -> return $ "CSChar"
Unsigned -> return $ "CUChar"
_ -> return $ "CChar"
typeName (CShortType _) s = case s of
Signed -> return $ "CShort"
Unsigned -> return $ "CUShort"
_ -> return $ "CShort"
typeName (CIntType _) s = case s of
Signed -> return $ "CInt"
Unsigned -> return $ "CUInt"
_ -> return $ "CInt"
typeName (CLongType _) s = case s of
Signed -> return $ "CLong"
Unsigned -> return $ "CULong"
_ -> return $ "CLong"
typeName (CTypeDef (Ident name _ _) _) _ = do
definition <- lookupType name
return $ fromMaybe ("<" ++ name ++ ">") definition
typeName (CComplexType _) _ = return $ ""
typeName (CSUType _ _) _ = return $ ""
typeName (CEnumType _ _) _ = return $ ""
typeName (CTypeOfExpr _ _) _ = return $ ""
typeName (CTypeOfType _ _) _ = return $ ""
typeName _ _ = return $ ""
-- Translation from C back to C. Needed because there's no good way to pretty
-- print a function's return type (including pointers on the declarator) in
-- language-c.
cTypeName :: CTypeSpecifier a -> Signedness -> Output String
cTypeName (CVoidType _) _ = return $ ""
cTypeName (CFloatType _) _ = return $ "float"
cTypeName (CDoubleType _) _ = return $ "double"
cTypeName (CBoolType _) _ = return $ "int"
cTypeName (CCharType _) s = case s of
Signed -> return $ "signed char"
Unsigned -> return $ "unsigned char"
_ -> return $ "char"
cTypeName (CShortType _) s = case s of
Signed -> return $ "signed short"
Unsigned -> return $ "unsigned short"
_ -> return $ "hort"
cTypeName (CIntType _) s = case s of
Signed -> return $ "signed int"
Unsigned -> return $ "unsigned int"
_ -> return $ "int"
cTypeName (CLongType _) s = case s of
Signed -> return $ "signed long"
Unsigned -> return $ "unsigned long"
_ -> return $ "long"
cTypeName (CTypeDef (Ident name _ _) _) _ = do
definition <- lookupType name
return $ fromMaybe name definition
cTypeName (CComplexType _) _ = return $ ""
cTypeName (CSUType _ _) _ = return $ ""
cTypeName (CEnumType _ _) _ = return $ ""
cTypeName (CTypeOfExpr _ _) _ = return $ ""
cTypeName (CTypeOfType _ _) _ = return $ ""
cTypeName _ _ = return $ ""
-- parseFile "/usr/bin/gcc" ["-U__BLOCKS__", "/Users/johnw/src/hlibgit2/libgit2/include/git2/types.h"]
-- c2hsc.hs