3 , ForeignFunctionInterface
4 , NondecreasingIndentation
7 -----------------------------------------------------------------------------
9 -- Module : GHC.IO.Encoding.Iconv
10 -- Copyright : (c) The University of Glasgow, 2008-2009
11 -- License : see libraries/base/LICENSE
13 -- Maintainer : libraries@haskell.org
14 -- Stability : internal
15 -- Portability : non-portable
17 -- This module provides text encoding/decoding using iconv
19 -----------------------------------------------------------------------------
22 module GHC.IO.Encoding.Iconv (
23 #if !defined(mingw32_HOST_OS)
27 utf16, utf16le, utf16be,
28 utf32, utf32le, utf32be,
34 #include "HsBaseConfig.h"
36 #if !defined(mingw32_HOST_OS)
38 import Foreign hiding (unsafePerformIO)
43 import GHC.IO.Encoding.Types
44 import GHC.List (span)
48 import System.IO.Unsafe (unsafePerformIO)
49 import System.Posix.Internals
54 iconv_trace :: String -> IO ()
56 | c_DEBUG_DUMP = puts s
57 | otherwise = return ()
59 puts :: String -> IO ()
60 puts s = do _ <- withCStringLen (s ++ "\n") $ \(p, len) ->
61 c_write 1 (castPtr p) (fromIntegral len)
64 -- -----------------------------------------------------------------------------
65 -- iconv encoders/decoders
67 {-# NOINLINE latin1 #-}
68 latin1 :: TextEncoding
69 latin1 = unsafePerformIO (mkTextEncoding "Latin1")
73 utf8 = unsafePerformIO (mkTextEncoding "UTF8")
75 {-# NOINLINE utf16 #-}
77 utf16 = unsafePerformIO (mkTextEncoding "UTF16")
79 {-# NOINLINE utf16le #-}
80 utf16le :: TextEncoding
81 utf16le = unsafePerformIO (mkTextEncoding "UTF16LE")
83 {-# NOINLINE utf16be #-}
84 utf16be :: TextEncoding
85 utf16be = unsafePerformIO (mkTextEncoding "UTF16BE")
87 {-# NOINLINE utf32 #-}
89 utf32 = unsafePerformIO (mkTextEncoding "UTF32")
91 {-# NOINLINE utf32le #-}
92 utf32le :: TextEncoding
93 utf32le = unsafePerformIO (mkTextEncoding "UTF32LE")
95 {-# NOINLINE utf32be #-}
96 utf32be :: TextEncoding
97 utf32be = unsafePerformIO (mkTextEncoding "UTF32BE")
99 {-# NOINLINE localeEncoding #-}
100 localeEncoding :: TextEncoding
101 localeEncoding = unsafePerformIO $ do
102 -- Use locale_charset() or nl_langinfo(CODESET) to get the encoding
103 -- if we have either of them.
104 cstr <- c_localeEncoding
105 r <- peekCString cstr
108 -- We hope iconv_t is a storable type. It should be, since it has at least the
109 -- value -1, which is a possible return value from iconv_open.
110 type IConv = CLong -- ToDo: (#type iconv_t)
112 foreign import ccall unsafe "hs_iconv_open"
113 hs_iconv_open :: CString -> CString -> IO IConv
115 foreign import ccall unsafe "hs_iconv_close"
116 hs_iconv_close :: IConv -> IO CInt
118 foreign import ccall unsafe "hs_iconv"
119 hs_iconv :: IConv -> Ptr CString -> Ptr CSize -> Ptr CString -> Ptr CSize
122 foreign import ccall unsafe "localeEncoding"
123 c_localeEncoding :: IO CString
125 haskellChar :: String
126 #ifdef WORDS_BIGENDIAN
127 haskellChar | charSize == 2 = "UTF-16BE"
128 | otherwise = "UTF-32BE"
130 haskellChar | charSize == 2 = "UTF-16LE"
131 | otherwise = "UTF-32LE"
135 char_shift | charSize == 2 = 1
138 mkTextEncoding :: String -> IO TextEncoding
139 mkTextEncoding charset = do
140 return (TextEncoding {
141 textEncodingName = charset,
142 mkTextDecoder = newIConv raw_charset (haskellChar ++ suffix) (iconvDecode cfm),
143 mkTextEncoder = newIConv haskellChar charset (iconvEncode cfm)})
145 -- An annoying feature of GNU iconv is that the //PREFIXES only take
146 -- effect when they appear on the tocode parameter to iconv_open:
147 (raw_charset, suffix) = span (/= '/') charset
149 newIConv :: String -> String
150 -> (IConv -> Buffer a -> Buffer b -> IO (Buffer a, Buffer b))
151 -> IO (BufferCodec a b ())
152 newIConv from to fn =
153 withCString from $ \ from_str ->
154 withCString to $ \ to_str -> do
155 iconvt <- throwErrnoIfMinus1 "mkTextEncoding" $ hs_iconv_open to_str from_str
156 let iclose = throwErrnoIfMinus1_ "Iconv.close" $ hs_iconv_close iconvt
160 -- iconv doesn't supply a way to save/restore the state
161 getState = return (),
162 setState = const $ return ()
165 iconvDecode :: IConv -> Buffer Word8 -> Buffer CharBufElem
166 -> IO (Buffer Word8, Buffer CharBufElem)
167 iconvDecode iconv_t ibuf obuf = iconvRecode iconv_t ibuf 0 obuf char_shift
169 iconvEncode :: IConv -> Buffer CharBufElem -> Buffer Word8
170 -> IO (Buffer CharBufElem, Buffer Word8)
171 iconvEncode iconv_t ibuf obuf = iconvRecode iconv_t ibuf char_shift obuf 0
173 iconvRecode :: IConv -> Buffer a -> Int -> Buffer b -> Int
174 -> IO (Buffer a, Buffer b)
176 input@Buffer{ bufRaw=iraw, bufL=ir, bufR=iw, bufSize=_ } iscale
177 output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow, bufSize=os } oscale
179 iconv_trace ("haskelChar=" ++ show haskellChar)
180 iconv_trace ("iconvRecode before, input=" ++ show (summaryBuffer input))
181 iconv_trace ("iconvRecode before, output=" ++ show (summaryBuffer output))
182 withRawBuffer iraw $ \ piraw -> do
183 withRawBuffer oraw $ \ poraw -> do
184 with (piraw `plusPtr` (ir `shiftL` iscale)) $ \ p_inbuf -> do
185 with (poraw `plusPtr` (ow `shiftL` oscale)) $ \ p_outbuf -> do
186 with (fromIntegral ((iw-ir) `shiftL` iscale)) $ \ p_inleft -> do
187 with (fromIntegral ((os-ow) `shiftL` oscale)) $ \ p_outleft -> do
188 res <- hs_iconv iconv_t p_inbuf p_inleft p_outbuf p_outleft
189 new_inleft <- peek p_inleft
190 new_outleft <- peek p_outleft
192 new_inleft' = fromIntegral new_inleft `shiftR` iscale
193 new_outleft' = fromIntegral new_outleft `shiftR` oscale
195 | new_inleft == 0 = input { bufL = 0, bufR = 0 }
196 | otherwise = input { bufL = iw - new_inleft' }
197 new_output = output{ bufR = os - new_outleft' }
198 iconv_trace ("iconv res=" ++ show res)
199 iconv_trace ("iconvRecode after, input=" ++ show (summaryBuffer new_input))
200 iconv_trace ("iconvRecode after, output=" ++ show (summaryBuffer new_output))
202 then do -- all input translated
203 return (new_input, new_output)
207 e | e == eINVAL || e == e2BIG
208 || e == eILSEQ && new_inleft' /= (iw-ir) -> do
209 iconv_trace ("iconv ignoring error: " ++ show (errnoToIOError "iconv" e Nothing Nothing))
210 -- Output overflow is harmless
212 -- Similarly, we ignore EILSEQ unless we converted no
213 -- characters. Sometimes iconv reports EILSEQ for a
214 -- character in the input even when there is no room
215 -- in the output; in this case we might be about to
216 -- change the encoding anyway, so the following bytes
217 -- could very well be in a different encoding.
218 -- This also helps with pinpointing EILSEQ errors: we
219 -- don't report it until the rest of the characters in
220 -- the buffer have been drained.
221 return (new_input, new_output)
224 iconv_trace ("iconv returned error: " ++ show (errnoToIOError "iconv" e Nothing Nothing))
225 throwErrno "iconvRecoder"
226 -- illegal sequence, or some other error
228 #endif /* !mingw32_HOST_OS */