Re: Segmentation Fault with Octave MXE under Windows

[Daniel J Sebald]

On 06/04/2014 04:31 AM, ijourneaux wrote:
> This is the bug report associated with this topic.
>
> https://savannah.gnu.org/bugs/?41699<https://savannah.gnu.org/bugs/?41699>
>
> I tried navigating up the backtrace to see where the problem was
> originating. The segfault goes through
>
> symbol_table::erase_scope (local_scope);
>
> which has a "// FIXME: this is really playing with fire." at line 236.
> Useful info or just a red herring?

Not sure.  local_scope is assigned the value "sid" which is passed into 
the routine.  If the procedure is that octave_user_function assumes 
control and cleanup of the function table for that scope, then it's 
fine.  But if some other part of the code is still using those parts of 
the function table then it is a problem.  Cleanup should be done 
elsewhere.  erase_scope() in symtab.h ensures the scope is local.

The comment isn't very helpful because it doesn't provide a hint why 
it's playing with fire.  The only other problem I could see if the local 
function in question is the function itself due to some type of 
recursive call, but I doubt that.

Try commenting out the line in question:

    // FIXME: this is really playing with fire.
//    symbol_table::erase_scope (local_scope);    //Line 236

That's not a solution, but if it doesn't fix the segfault, then the 
likelihood is that isn't the problem in this case.

Dan