Accessing to a nested array causes segmentation fault

[uenoB]

When I write a parallel sorting program, I found that the following code causes segmentation fault both on my mac and linux.

fun copy a b e d j =
    if e < b then ()
    else let val v = Array.sub (Array.sub (a, 0), b)
         in Array.update (Array.sub (d, 0), j, v);
            copy a (b+1) e d (j+1)
         end

fun sort a b e =
    if e <= b then () else
    let val q = Int.quot (b + e, 2)
    in sort a b q;
       sort a (q+1) e;
       copy a b e a b
    end

val a = Array.array (1, Array.array (1024, 0))
val _ = sort a 0 1023

I checked out the repository and compiled the compiler as follows:

git clone https://github.com/ManticoreProject/manticore.git
git checkout 757fbcc4d   # to make clear which revision I used
autoconf -Iconfig
autoheader -Iconfig
./configure --prefix=$PWD/dest
mkdir -p dest/bin dest/lib
make install

I saved the above code in bug.pml and executed it as follows:

$ dest/bin/pmlc -o bug bug.pml
$ ./bug
Segmentation fault

[JohnReppy]

This code is not a parallel program in Manticore. The Array structure is just provided for sequential testing/benchmarking purposes (strictly speaking, it shouldn't even exist, since Manticore does not expose imperative features to the user).

We will take a look into what causes the crash when we get a chance.