[Bug middle-end/71224] Looping over local copy of aggregate invokes undefined behavior -Waggressive-loop-optimizations

[ibuclaw at gdcproject dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71224

--- Comment #1 from Iain Buclaw <ibuclaw at gdcproject dot org> ---
Oh, and also happens if I move the pointer + length adjustment into the loop.

---
void setlength(Array* pthis, size_t nlength)
{
    Array aggr = {.length=pthis->length, .ptr=pthis->ptr};

    for (size_t key = 0; key < aggr.length - nlength; key++)
        aggr.ptr[key + nlength] = 1;
}
---