1 {-# OPTIONS_GHC -XNoImplicitPrelude #-}
2 -----------------------------------------------------------------------------
4 -- Module : GHC.IO.Encoding.Iconv
5 -- Copyright : (c) The University of Glasgow, 2008-2009
6 -- License : see libraries/base/LICENSE
8 -- Maintainer : libraries@haskell.org
9 -- Stability : internal
10 -- Portability : non-portable
12 -- This module provides text encoding/decoding using iconv
14 -----------------------------------------------------------------------------
17 module GHC.IO.Encoding.Iconv (
18 #if !defined(mingw32_HOST_OS)
22 utf16, utf16le, utf16be,
23 utf32, utf32le, utf32be,
29 #include "HsBaseConfig.h"
31 #if !defined(mingw32_HOST_OS)
40 import GHC.IO.Encoding.Types
45 import System.Posix.Internals
48 iconv_trace :: String -> IO ()
52 iconv_trace s = puts s
54 puts :: String -> IO ()
55 puts s = do withCStringLen (s++"\n") $ \(p, len) ->
56 c_write 1 (castPtr p) (fromIntegral len)
61 iconv_trace _ = return ()
65 -- -----------------------------------------------------------------------------
66 -- iconv encoders/decoders
68 {-# NOINLINE latin1 #-}
69 latin1 :: TextEncoding
70 latin1 = unsafePerformIO (mkTextEncoding "Latin1")
74 utf8 = unsafePerformIO (mkTextEncoding "UTF8")
76 {-# NOINLINE utf16 #-}
78 utf16 = unsafePerformIO (mkTextEncoding "UTF16")
80 {-# NOINLINE utf16le #-}
81 utf16le :: TextEncoding
82 utf16le = unsafePerformIO (mkTextEncoding "UTF16LE")
84 {-# NOINLINE utf16be #-}
85 utf16be :: TextEncoding
86 utf16be = unsafePerformIO (mkTextEncoding "UTF16BE")
88 {-# NOINLINE utf32 #-}
90 utf32 = unsafePerformIO (mkTextEncoding "UTF32")
92 {-# NOINLINE utf32le #-}
93 utf32le :: TextEncoding
94 utf32le = unsafePerformIO (mkTextEncoding "UTF32LE")
96 {-# NOINLINE utf32be #-}
97 utf32be :: TextEncoding
98 utf32be = unsafePerformIO (mkTextEncoding "UTF32BE")
100 {-# NOINLINE localeEncoding #-}
101 localeEncoding :: TextEncoding
102 localeEncoding = unsafePerformIO $ do
104 cstr <- c_localeEncoding -- use nl_langinfo(CODESET) to get the encoding
106 r <- peekCString cstr
109 mkTextEncoding "" -- GNU iconv accepts "" to mean the -- locale encoding.
112 -- We hope iconv_t is a storable type. It should be, since it has at least the
113 -- value -1, which is a possible return value from iconv_open.
114 type IConv = CLong -- ToDo: (#type iconv_t)
116 foreign import ccall unsafe "hs_iconv_open"
117 hs_iconv_open :: CString -> CString -> IO IConv
119 foreign import ccall unsafe "hs_iconv_close"
120 hs_iconv_close :: IConv -> IO CInt
122 foreign import ccall unsafe "hs_iconv"
123 hs_iconv :: IConv -> Ptr CString -> Ptr CSize -> Ptr CString -> Ptr CSize
126 foreign import ccall unsafe "localeEncoding"
127 c_localeEncoding :: IO CString
129 haskellChar :: String
130 #ifdef WORDS_BIGENDIAN
131 haskellChar | charSize == 2 = "UTF-16BE"
132 | otherwise = "UTF-32BE"
134 haskellChar | charSize == 2 = "UTF-16LE"
135 | otherwise = "UTF-32LE"
139 char_shift | charSize == 2 = 1
142 mkTextEncoding :: String -> IO TextEncoding
143 mkTextEncoding charset = do
144 return (TextEncoding {
145 mkTextDecoder = newIConv charset haskellChar iconvDecode,
146 mkTextEncoder = newIConv haskellChar charset iconvEncode})
148 newIConv :: String -> String
149 -> (IConv -> Buffer a -> Buffer b -> IO (Buffer a, Buffer b))
150 -> IO (BufferCodec a b ())
151 newIConv from to fn =
152 withCString from $ \ from_str ->
153 withCString to $ \ to_str -> do
154 iconvt <- throwErrnoIfMinus1 "mkTextEncoding" $ hs_iconv_open to_str from_str
155 let iclose = throwErrnoIfMinus1_ "Iconv.close" $ hs_iconv_close iconvt
159 -- iconv doesn't supply a way to save/restore the state
160 getState = return (),
161 setState = const $ return ()
164 iconvDecode :: IConv -> Buffer Word8 -> Buffer CharBufElem
165 -> IO (Buffer Word8, Buffer CharBufElem)
166 iconvDecode iconv_t ibuf obuf = iconvRecode iconv_t ibuf 0 obuf char_shift
168 iconvEncode :: IConv -> Buffer CharBufElem -> Buffer Word8
169 -> IO (Buffer CharBufElem, Buffer Word8)
170 iconvEncode iconv_t ibuf obuf = iconvRecode iconv_t ibuf char_shift obuf 0
172 iconvRecode :: IConv -> Buffer a -> Int -> Buffer b -> Int
173 -> IO (Buffer a, Buffer b)
175 input@Buffer{ bufRaw=iraw, bufL=ir, bufR=iw, bufSize=_ } iscale
176 output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow, bufSize=os } oscale
178 iconv_trace ("haskelChar=" ++ show haskellChar)
179 iconv_trace ("iconvRecode before, input=" ++ show (summaryBuffer input))
180 iconv_trace ("iconvRecode before, output=" ++ show (summaryBuffer output))
181 withRawBuffer iraw $ \ piraw -> do
182 withRawBuffer oraw $ \ poraw -> do
183 with (piraw `plusPtr` (ir `shiftL` iscale)) $ \ p_inbuf -> do
184 with (poraw `plusPtr` (ow `shiftL` oscale)) $ \ p_outbuf -> do
185 with (fromIntegral ((iw-ir) `shiftL` iscale)) $ \ p_inleft -> do
186 with (fromIntegral ((os-ow) `shiftL` oscale)) $ \ p_outleft -> do
187 res <- hs_iconv iconv_t p_inbuf p_inleft p_outbuf p_outleft
188 new_inleft <- peek p_inleft
189 new_outleft <- peek p_outleft
191 new_inleft' = fromIntegral new_inleft `shiftR` iscale
192 new_outleft' = fromIntegral new_outleft `shiftR` oscale
194 | new_inleft == 0 = input { bufL = 0, bufR = 0 }
195 | otherwise = input { bufL = iw - new_inleft' }
196 new_output = output{ bufR = os - new_outleft' }
197 iconv_trace ("iconv res=" ++ show res)
198 iconv_trace ("iconvRecode after, input=" ++ show (summaryBuffer new_input))
199 iconv_trace ("iconvRecode after, output=" ++ show (summaryBuffer new_output))
201 then do -- all input translated
202 return (new_input, new_output)
207 || (e == e2BIG || e == eILSEQ) && new_inleft' /= (iw-ir) -> do
208 iconv_trace ("iconv ignoring error: " ++ show (errnoToIOError "iconv" e Nothing Nothing))
209 -- Output overflow is relatively harmless, unless
210 -- we made no progress at all.
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 throwErrno "iconvRecoder"
225 -- illegal sequence, or some other error
227 #endif /* !mingw32_HOST_OS */