[Haskell-cafe] Re: Trying to figure out a segfault caused by haskeline.

31 Mar 2010

      Hi,

Nobody seems to have any idea what is happening yet. Though thanks for
trying dagit (forgot to add haskell-cafe to my repliess to him).

Quick update incase it helps, compiling with profiling and running with the
-xc option results in,

Main.CAF:runInputT_rOASegmentation fault

I'm still working on it but could it be the configuration file? thats the
thing the haskeline accesses files for right?

On Mon, Mar 29, 2010 at 8:28 PM, ryan winkelmaier wrote:
...
Hey everyone,
I'm looking for help with a seg fault that takes out both my ghci and darcs
as well as anything that uses haskeline. A bug on the haskeline trac hasn't
gotten any response so I figured I might as well figure this out myself and
get ghci up and running again.
Using the test program below I get the same segmentation fault, so I run it
using gdb and get the following,
Program received signal SIGSEGV, Segmentation fault.
0x000000000053fdce in base_ForeignziCziString_zdwa_info ()
My knowledge of this is very limited from here on out so here is what I was
able to get together.
On the 20th call of base_ForeignziCziString_zdwa_info
r14 is 0 so
0x000000000053fdce <+22>:    movsbq (%r14),%rax
produces the segfault.
From what I understand this is happening in the Foreign.C.String module but
thats as much as I know.
Anyone have advice on where to go next?
System info:
Distribution: gentoo amd64
Ghc version: currently 6.12.1 (though the segfault happends on any of the
ones with haskeline)
Haskeline version: 0.6.2.2
Here is the test program
----------------------------------------------------------------------------------------------------
module Main where
import System.Console.Haskeline
import System.Environment
{--
Testing the line-input functions and their interaction with ctrl-c signals.
Usage:
./Test          (line input)
./Test chars    (character input)
--}
mySettings :: Settings IO
mySettings = defaultSettings {historyFile = Just "myhist"}
main :: IO ()
main = do
        args <- getArgs
        let inputFunc = case args of
                ["chars"] -> fmap (fmap (\c -> [c])) . getInputChar
                _ -> getInputLine
        runInputT mySettings $ withInterrupt $ loop inputFunc 0
    where
        loop inputFunc n = do
            minput <-  handleInterrupt (return (Just "Caught interrupted"))
                        $ inputFunc (show n ++ ":")
            case minput of
                Nothing -> return ()
                Just "quit" -> return ()
                Just "q" -> return ()
                Just s -> do
                            outputStrLn ("line " ++ show n ++ ":" ++ s)
                            loop inputFunc (n+1)
------------------------------------------------------------------------------------------------------------------------
Syfran