ghc-internal-9.1001.0: src/GHC/Internal/IO/Encoding/UTF8.hs
{-# LANGUAGE Trustworthy #-}
{-# LANGUAGE NoImplicitPrelude
, BangPatterns
, NondecreasingIndentation
, MagicHash
, UnboxedTuples
#-}
{-# OPTIONS_GHC -funbox-strict-fields #-}
-----------------------------------------------------------------------------
-- |
-- Module : GHC.Internal.IO.Encoding.UTF8
-- Copyright : (c) The University of Glasgow, 2009
-- License : see libraries/base/LICENSE
--
-- Maintainer : libraries@haskell.org
-- Stability : internal
-- Portability : non-portable
--
-- UTF-8 Codec for the IO library
--
-- This is one of several UTF-8 implementations provided by GHC; see Note
-- [GHC's many UTF-8 implementations] in "GHC.Encoding.UTF8" for an
-- overview.
--
-- Portions Copyright : (c) Tom Harper 2008-2009,
-- (c) Bryan O'Sullivan 2009,
-- (c) Duncan Coutts 2009
--
-----------------------------------------------------------------------------
module GHC.Internal.IO.Encoding.UTF8 (
utf8, mkUTF8,
utf8_bom, mkUTF8_bom
) where
import GHC.Internal.Base
import GHC.Internal.Real
import GHC.Internal.Num
import GHC.Internal.IORef
-- import GHC.Internal.IO
import GHC.Internal.IO.Buffer
import GHC.Internal.IO.Encoding.Failure
import GHC.Internal.IO.Encoding.Types
import GHC.Internal.Word
import GHC.Internal.Data.Bits
utf8 :: TextEncoding
utf8 = mkUTF8 ErrorOnCodingFailure
-- | @since base-4.4.0.0
mkUTF8 :: CodingFailureMode -> TextEncoding
mkUTF8 cfm = TextEncoding { textEncodingName = "UTF-8",
mkTextDecoder = utf8_DF cfm,
mkTextEncoder = utf8_EF cfm }
utf8_DF :: CodingFailureMode -> IO (TextDecoder ())
utf8_DF cfm =
return (BufferCodec# {
encode# = utf8_decode,
recover# = recoverDecode# cfm,
close# = return (),
getState# = return (),
setState# = const $ return ()
})
utf8_EF :: CodingFailureMode -> IO (TextEncoder ())
utf8_EF cfm =
return (BufferCodec# {
encode# = utf8_encode,
recover# = recoverEncode# cfm,
close# = return (),
getState# = return (),
setState# = const $ return ()
})
utf8_bom :: TextEncoding
utf8_bom = mkUTF8_bom ErrorOnCodingFailure
mkUTF8_bom :: CodingFailureMode -> TextEncoding
mkUTF8_bom cfm = TextEncoding { textEncodingName = "UTF-8BOM",
mkTextDecoder = utf8_bom_DF cfm,
mkTextEncoder = utf8_bom_EF cfm }
utf8_bom_DF :: CodingFailureMode -> IO (TextDecoder Bool)
utf8_bom_DF cfm = do
ref <- newIORef True
return (BufferCodec# {
encode# = utf8_bom_decode ref,
recover# = recoverDecode# cfm,
close# = return (),
getState# = readIORef ref,
setState# = writeIORef ref
})
utf8_bom_EF :: CodingFailureMode -> IO (TextEncoder Bool)
utf8_bom_EF cfm = do
ref <- newIORef True
return (BufferCodec# {
encode# = utf8_bom_encode ref,
recover# = recoverEncode# cfm,
close# = return (),
getState# = readIORef ref,
setState# = writeIORef ref
})
utf8_bom_decode :: IORef Bool -> DecodeBuffer#
utf8_bom_decode ref
input@Buffer{ bufRaw=iraw, bufL=ir, bufR=iw, bufSize=_ }
output
st0
= do
let !(# st1, first #) = unIO (readIORef ref) st0
if not first
then utf8_decode input output st1
else do
let no_bom = let !(# st', () #) = unIO (writeIORef ref False) st1 in utf8_decode input output st'
if iw - ir < 1 then (# st1,InputUnderflow,input,output #) else do
let !(# st2, c0 #) = unIO (readWord8Buf iraw ir) st1
if (c0 /= bom0) then no_bom else do
if iw - ir < 2 then (# st2,InputUnderflow,input,output #) else do
let !(# st3, c1 #) = unIO (readWord8Buf iraw (ir+1)) st2
if (c1 /= bom1) then no_bom else do
if iw - ir < 3 then (# st3,InputUnderflow,input,output #) else do
let !(# st4, c2 #) = unIO (readWord8Buf iraw (ir+2)) st3
if (c2 /= bom2) then no_bom else do
-- found a BOM, ignore it and carry on
let !(# st5, () #) = unIO (writeIORef ref False) st4
utf8_decode input{ bufL = ir + 3 } output st5
utf8_bom_encode :: IORef Bool -> EncodeBuffer#
utf8_bom_encode ref input
output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow, bufSize=os }
st0
= do
let !(# st1, b #) = unIO (readIORef ref) st0
if not b then utf8_encode input output st1
else if os - ow < 3
then (# st1,OutputUnderflow,input,output #)
else do
let !(# st2, () #) = unIO (writeIORef ref False) st1
!(# st3, () #) = unIO (writeWord8Buf oraw ow bom0) st2
!(# st4, () #) = unIO (writeWord8Buf oraw (ow+1) bom1) st3
!(# st5, () #) = unIO (writeWord8Buf oraw (ow+2) bom2) st4
utf8_encode input output{ bufR = ow+3 } st5
bom0, bom1, bom2 :: Word8
bom0 = 0xef
bom1 = 0xbb
bom2 = 0xbf
utf8_decode :: DecodeBuffer#
utf8_decode
input@Buffer{ bufRaw=iraw, bufL=ir0, bufR=iw, bufSize=_ }
output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow0, bufSize=os }
st
= let
loop :: Int -> Int -> DecodingBuffer#
loop !ir !ow st0
| ow >= os = done OutputUnderflow ir ow st0
| ir >= iw = done InputUnderflow ir ow st0
| otherwise = do
let !(# st1, c0 #) = unIO (readWord8Buf iraw ir) st0
case c0 of
_ | c0 <= 0x7f -> do
let !(# st2, ow' #) = unIO (writeCharBuf oraw ow (unsafeChr (fromIntegral c0))) st1
loop (ir+1) ow' st2
| c0 >= 0xc0 && c0 <= 0xc1 -> invalid st1 -- Overlong forms
| c0 >= 0xc2 && c0 <= 0xdf ->
if iw - ir < 2 then done InputUnderflow ir ow st1 else do
let !(# st2, c1 #) = unIO (readWord8Buf iraw (ir+1)) st1
if (c1 < 0x80 || c1 >= 0xc0) then invalid st2 else do
let !(# st3, ow' #) = unIO (writeCharBuf oraw ow (chr2 c0 c1)) st2
loop (ir+2) ow' st3
| c0 >= 0xe0 && c0 <= 0xef ->
case iw - ir of
1 -> done InputUnderflow ir ow st1
2 -> do -- check for an error even when we don't have
-- the full sequence yet (#3341)
let !(# st2, c1 #) = unIO (readWord8Buf iraw (ir+1)) st1
if not (validate3 c0 c1 0x80)
then invalid st2 else done InputUnderflow ir ow st2
_ -> do
let !(# st2, c1 #) = unIO (readWord8Buf iraw (ir+1)) st1
let !(# st3, c2 #) = unIO (readWord8Buf iraw (ir+2)) st2
if not (validate3 c0 c1 c2) then invalid st3 else do
let !(# st4, ow' #) = unIO (writeCharBuf oraw ow (chr3 c0 c1 c2)) st3
loop (ir+3) ow' st4
| c0 >= 0xf0 ->
case iw - ir of
1 -> done InputUnderflow ir ow st1
2 -> do -- check for an error even when we don't have
-- the full sequence yet (#3341)
let !(# st2, c1 #) = unIO (readWord8Buf iraw (ir+1)) st1
if not (validate4 c0 c1 0x80 0x80)
then invalid st2 else done InputUnderflow ir ow st2
3 -> do
let !(# st2, c1 #) = unIO (readWord8Buf iraw (ir+1)) st1
!(# st3, c2 #) = unIO (readWord8Buf iraw (ir+2)) st2
if not (validate4 c0 c1 c2 0x80)
then invalid st3 else done InputUnderflow ir ow st3
_ -> do
let !(# st2, c1 #) = unIO (readWord8Buf iraw (ir+1)) st1
!(# st3, c2 #) = unIO (readWord8Buf iraw (ir+2)) st2
!(# st4, c3 #) = unIO (readWord8Buf iraw (ir+3)) st3
if not (validate4 c0 c1 c2 c3) then invalid st4 else do
let !(# st5, ow' #) = unIO (writeCharBuf oraw ow (chr4 c0 c1 c2 c3)) st4
loop (ir+4) ow' st5
| otherwise ->
invalid st1
where
invalid :: DecodingBuffer#
invalid st' = done InvalidSequence ir ow st'
-- lambda-lifted, to avoid thunks being built in the inner-loop:
{-# NOINLINE done #-}
done :: CodingProgress -> Int -> Int -> DecodingBuffer#
done why !ir !ow st' =
let !ri = if ir == iw then input{ bufL = 0, bufR = 0} else input{ bufL = ir }
!ro = output { bufR = ow }
in (# st', why, ri, ro #)
in
loop ir0 ow0 st
utf8_encode :: EncodeBuffer#
utf8_encode
input@Buffer{ bufRaw=iraw, bufL=ir0, bufR=iw, bufSize=_ }
output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow0, bufSize=os }
st
= let
{-# NOINLINE done #-}
done :: CodingProgress -> Int -> Int -> EncodingBuffer#
done why !ir !ow st' =
let !ri = if ir == iw then input{ bufL = 0, bufR = 0 } else input{ bufL = ir }
!ro = output{ bufR = ow }
in (# st', why, ri, ro #)
loop :: Int -> Int -> EncodingBuffer#
loop !ir !ow st0
| ow >= os = done OutputUnderflow ir ow st0
| ir >= iw = done InputUnderflow ir ow st0
| otherwise = do
let !(# st1, (c,ir') #) = unIO (readCharBuf iraw ir) st0
case ord c of
x | x <= 0x7F -> do
let !(# st2, () #) = unIO (writeWord8Buf oraw ow (fromIntegral x)) st1
loop ir' (ow+1) st2
| x <= 0x07FF ->
if os - ow < 2 then done OutputUnderflow ir ow st1 else do
let (c1,c2) = ord2 c
!(# st2, () #) = unIO (writeWord8Buf oraw ow c1) st1
!(# st3, () #) = unIO (writeWord8Buf oraw (ow+1) c2) st2
loop ir' (ow+2) st3
| x <= 0xFFFF -> if isSurrogate c then done InvalidSequence ir ow st1 else do
if os - ow < 3 then done OutputUnderflow ir ow st1 else do
let (c1,c2,c3) = ord3 c
!(# st2, () #) = unIO (writeWord8Buf oraw ow c1) st1
!(# st3, () #) = unIO (writeWord8Buf oraw (ow+1) c2) st2
!(# st4, () #) = unIO (writeWord8Buf oraw (ow+2) c3) st3
loop ir' (ow+3) st4
| otherwise -> do
if os - ow < 4 then done OutputUnderflow ir ow st1 else do
let (c1,c2,c3,c4) = ord4 c
!(# st2, () #) = unIO (writeWord8Buf oraw ow c1) st1
!(# st3, () #) = unIO (writeWord8Buf oraw (ow+1) c2) st2
!(# st4, () #) = unIO (writeWord8Buf oraw (ow+2) c3) st3
!(# st5, () #) = unIO (writeWord8Buf oraw (ow+3) c4) st4
loop ir' (ow+4) st5
in
loop ir0 ow0 st
-- -----------------------------------------------------------------------------
-- UTF-8 primitives, lifted from Data.Text.Fusion.Utf8
ord2 :: Char -> (Word8,Word8)
ord2 c = assert (n >= 0x80 && n <= 0x07ff) (x1,x2)
where
n = ord c
x1 = fromIntegral $ (n `shiftR` 6) + 0xC0
x2 = fromIntegral $ (n .&. 0x3F) + 0x80
ord3 :: Char -> (Word8,Word8,Word8)
ord3 c = assert (n >= 0x0800 && n <= 0xffff) (x1,x2,x3)
where
n = ord c
x1 = fromIntegral $ (n `shiftR` 12) + 0xE0
x2 = fromIntegral $ ((n `shiftR` 6) .&. 0x3F) + 0x80
x3 = fromIntegral $ (n .&. 0x3F) + 0x80
ord4 :: Char -> (Word8,Word8,Word8,Word8)
ord4 c = assert (n >= 0x10000) (x1,x2,x3,x4)
where
n = ord c
x1 = fromIntegral $ (n `shiftR` 18) + 0xF0
x2 = fromIntegral $ ((n `shiftR` 12) .&. 0x3F) + 0x80
x3 = fromIntegral $ ((n `shiftR` 6) .&. 0x3F) + 0x80
x4 = fromIntegral $ (n .&. 0x3F) + 0x80
chr2 :: Word8 -> Word8 -> Char
chr2 (W8# x1#) (W8# x2#) = C# (chr# (z1# +# z2#))
where
!y1# = word2Int# (word8ToWord# x1#)
!y2# = word2Int# (word8ToWord# x2#)
!z1# = uncheckedIShiftL# (y1# -# 0xC0#) 6#
!z2# = y2# -# 0x80#
{-# INLINE chr2 #-}
chr3 :: Word8 -> Word8 -> Word8 -> Char
chr3 (W8# x1#) (W8# x2#) (W8# x3#) = C# (chr# (z1# +# z2# +# z3#))
where
!y1# = word2Int# (word8ToWord# x1#)
!y2# = word2Int# (word8ToWord# x2#)
!y3# = word2Int# (word8ToWord# x3#)
!z1# = uncheckedIShiftL# (y1# -# 0xE0#) 12#
!z2# = uncheckedIShiftL# (y2# -# 0x80#) 6#
!z3# = y3# -# 0x80#
{-# INLINE chr3 #-}
chr4 :: Word8 -> Word8 -> Word8 -> Word8 -> Char
chr4 (W8# x1#) (W8# x2#) (W8# x3#) (W8# x4#) =
C# (chr# (z1# +# z2# +# z3# +# z4#))
where
!y1# = word2Int# (word8ToWord# x1#)
!y2# = word2Int# (word8ToWord# x2#)
!y3# = word2Int# (word8ToWord# x3#)
!y4# = word2Int# (word8ToWord# x4#)
!z1# = uncheckedIShiftL# (y1# -# 0xF0#) 18#
!z2# = uncheckedIShiftL# (y2# -# 0x80#) 12#
!z3# = uncheckedIShiftL# (y3# -# 0x80#) 6#
!z4# = y4# -# 0x80#
{-# INLINE chr4 #-}
between :: Word8 -- ^ byte to check
-> Word8 -- ^ lower bound
-> Word8 -- ^ upper bound
-> Bool
between x y z = x >= y && x <= z
{-# INLINE between #-}
validate3 :: Word8 -> Word8 -> Word8 -> Bool
{-# INLINE validate3 #-}
validate3 x1 x2 x3 = validate3_1 ||
validate3_2 ||
validate3_3 ||
validate3_4
where
validate3_1 = (x1 == 0xE0) &&
between x2 0xA0 0xBF &&
between x3 0x80 0xBF
validate3_2 = between x1 0xE1 0xEC &&
between x2 0x80 0xBF &&
between x3 0x80 0xBF
validate3_3 = x1 == 0xED &&
between x2 0x80 0x9F &&
between x3 0x80 0xBF
validate3_4 = between x1 0xEE 0xEF &&
between x2 0x80 0xBF &&
between x3 0x80 0xBF
validate4 :: Word8 -> Word8 -> Word8 -> Word8 -> Bool
{-# INLINE validate4 #-}
validate4 x1 x2 x3 x4 = validate4_1 ||
validate4_2 ||
validate4_3
where
validate4_1 = x1 == 0xF0 &&
between x2 0x90 0xBF &&
between x3 0x80 0xBF &&
between x4 0x80 0xBF
validate4_2 = between x1 0xF1 0xF3 &&
between x2 0x80 0xBF &&
between x3 0x80 0xBF &&
between x4 0x80 0xBF
validate4_3 = x1 == 0xF4 &&
between x2 0x80 0x8F &&
between x3 0x80 0xBF &&
between x4 0x80 0xBF