On 7/27/17 2:46 PM, Jonathan M Davis via Digitalmars-d wrote:
However, one issue that has been brought up from time to time and AFAIK has
never really been addressed is that apparently if an object is large enough,
when you access one of its members when the pointer is null, you won't get a
segfault (I think that it was something like if the object was greater than
a page in size). So, as I understand it, ludicrously large objects _could_
result in @safety problems with null pointers. This would not happen in
normal code, but it can happen. And if we want @safe to make the guarantees
that it claims, we really should either disallow such objects or insert null
checks for them. For smaller objects though, what's the point? It buys us
nothing if the hardware is already doing it, and the only hardware that
wouldn't do it should be too old to matter at this point.
Yes: https://issues.dlang.org/show_bug.cgi?id=5176
There is a way to "fix" this: any time you access an object field that
goes outside the page size, do a null check on the base pointer.
-Steve
