diff options
Diffstat (limited to 'libraries/base/GHC')
| -rw-r--r-- | libraries/base/GHC/IO/Encoding.hs | 14 | ||||
| -rw-r--r-- | libraries/base/GHC/TopHandler.hs | 29 |
2 files changed, 41 insertions, 2 deletions
diff --git a/libraries/base/GHC/IO/Encoding.hs b/libraries/base/GHC/IO/Encoding.hs index 31683b4e68..014b61b8b0 100644 --- a/libraries/base/GHC/IO/Encoding.hs +++ b/libraries/base/GHC/IO/Encoding.hs @@ -235,7 +235,14 @@ mkTextEncoding e = case mb_coding_failure_mode of _ -> Nothing mkTextEncoding' :: CodingFailureMode -> String -> IO TextEncoding -mkTextEncoding' cfm enc = case [toUpper c | c <- enc, c /= '-'] of +mkTextEncoding' cfm enc + -- First, specifically match on ASCII encodings directly using + -- several possible aliases (specified by RFC 1345 & co), which + -- allows us to handle ASCII conversions without iconv at all (see + -- trac #10298). + | any (== enc) ansiEncNames = return (UTF8.mkUTF8 cfm) + -- Otherwise, handle other encoding needs via iconv. + | otherwise = case [toUpper c | c <- enc, c /= '-'] of "UTF8" -> return $ UTF8.mkUTF8 cfm "UTF16" -> return $ UTF16.mkUTF16 cfm "UTF16LE" -> return $ UTF16.mkUTF16le cfm @@ -249,6 +256,11 @@ mkTextEncoding' cfm enc = case [toUpper c | c <- enc, c /= '-'] of #else _ -> Iconv.mkIconvEncoding cfm enc #endif + where + ansiEncNames = -- ASCII aliases + [ "ANSI_X3.4-1968", "iso-ir-6", "ANSI_X3.4-1986", "ISO_646.irv:1991" + , "US-ASCII", "us", "IBM367", "cp367", "csASCII", "ASCII", "ISO646-US" + ] latin1_encode :: CharBuffer -> Buffer Word8 -> IO (CharBuffer, Buffer Word8) latin1_encode input output = fmap (\(_why,input',output') -> (input',output')) $ Latin1.latin1_encode input output -- unchecked, used for char8 diff --git a/libraries/base/GHC/TopHandler.hs b/libraries/base/GHC/TopHandler.hs index d7c00384e4..e725196cdf 100644 --- a/libraries/base/GHC/TopHandler.hs +++ b/libraries/base/GHC/TopHandler.hs @@ -157,13 +157,40 @@ real_handler exit se = do Just (ExitFailure n) -> exit n -- EPIPE errors received for stdout are ignored (#2699) - _ -> case fromException se of + _ -> catch (case fromException se of Just IOError{ ioe_type = ResourceVanished, ioe_errno = Just ioe, ioe_handle = Just hdl } | Errno ioe == ePIPE, hdl == stdout -> exit 0 _ -> do reportError se exit 1 + ) (disasterHandler exit) -- See Note [Disaster with iconv] + +-- don't use errorBelch() directly, because we cannot call varargs functions +-- using the FFI. +foreign import ccall unsafe "HsBase.h errorBelch2" + errorBelch :: CString -> CString -> IO () + +disasterHandler :: (Int -> IO a) -> IOError -> IO a +disasterHandler exit _ = + withCAString "%s" $ \fmt -> + withCAString msgStr $ \msg -> + errorBelch fmt msg >> exit 1 + where msgStr = "encountered an exception while trying to report an exception" + +{- Note [Disaster with iconv] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +When using iconv, it's possible for things like iconv_open to fail in +restricted environments (like an initram or restricted container), but +when this happens the error raised inevitably calls `peekCString`, +which depends on the users locale, which depends on using +`iconv_open`... which causes an infinite loop. + +This occurrence is also known as tickets #10298 and #7695. So to work +around it we just set _another_ error handler and bail directly by +calling the RTS, without iconv at all. +-} -- try to flush stdout/stderr, but don't worry if we fail |