OpenEuphoria

Re: Strange machine-level exception

• Posted by CChris <christian.cuvier at agriculture.gouv.fr> Jun 18, 2007
• 574 views

I just peeked at the code in be_runtime.c. I haven't coded in C for a couple
years, yet something looks wrong to me - but again, *I* might be quite wrong just
as well.

Line 4654 says: "bv = *(++bp);", assuming ++bp can be read always. If the end of
the sequence is being reached, one would expect *(++bp) to be NOVALUE. Aren't
there cases (under Windows) where this might not be true, resulting in a bad read
ptr error?  Or perhaps it is Windows that catches the error and DOS/Linux don't
care.

Additionally, I wondered, reading lines 4633-4638, whether
else if (bv == NOVALUE) {
    break;
}
else if (compare(a, bv) == 0) {  /* not INT-INT case */
    return bp - (object_ptr)b->base;
}

shouldn't read
else {
    if (bv == NOVALUE) 
        break;
    else if (compare(a, bv) == 0)   /* not INT-INT case */
        return bp - (object_ptr)b->base;
}

instead. Perhaps the two are equivalent, but at least the logic is clearer in
the second form.

CChris