Crash.hs:
------------------------------------------------------------------------
import FFI
import Monad
stringToInteger:: Addr -> IO (StablePtr Integer)
stringToInteger a = addrToString a >>= makeStablePtr . read
integerToString:: StablePtr Integer -> IO Addr
integerToString sp = deRefStablePtr sp >>= stringToAddr . show
addrToString:: Addr -> IO String
addrToString a = do
c <- peek a
if c == '\0'
then return []
else liftM (c:) $ addrToString (a `plusAddr` 1)
stringToAddr:: String -> IO Addr
stringToAddr s = do
let s' = s++"\0"
a <- malloc (length s')
zipWithM (pokeElemOff a) [0..] s'
return a
mul:: StablePtr Integer -> StablePtr Integer -> IO (StablePtr Integer)
mul a b = do
a' <- deRefStablePtr a
b' <- deRefStablePtr b
makeStablePtr (a' * b')
foreign import "test" main :: IO ()
foreign export stringToInteger :: Addr -> IO (StablePtr Integer)
foreign export integerToString :: StablePtr Integer -> IO Addr
foreign export mul :: StablePtr Integer
-> StablePtr Integer
-> IO (StablePtr Integer)
------------------------------------------------------------------------
crash.c:
------------------------------------------------------------------------
#include <Rts.h>
#include "Crash_stub.h"
void test (void)
{
StgStablePtr a = stringToInteger ("1000000000000000000000000000001");
StgStablePtr b = stringToInteger ("1000000000000000000000000000002");
StgStablePtr c = mul (a, b);
printf ("%s\n", integerToString (c));
a = stringToInteger ("1000000000000000000000000000003");
b = stringToInteger ("1000000000000000000000000000004");
c = mul (a, b);
printf ("%s\n", integerToString (c));
}
------------------------------------------------------------------------
$ ghc -fglasgow-exts -c Crash.hs
$ ghc -c crash.c
$ ghc -fglasgow-exts Crash.o Crash_stub.o crash.o -o crash
$ ./crash
1000000000000000000000000000003000000000000000000000000000002
zsh: segmentation fault ./crash
$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 4.06
With related examples I also get "ARR_WORDS object entered!".
Change two definitions:
stringToInteger a = do s <- addrToString a; makeStablePtr (read s)
integerToString sp = do i <- deRefStablePtr sp; stringToAddr (show i)
--
__("< Marcin Kowalczyk * [EMAIL PROTECTED] http://qrczak.ids.net.pl/
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