Re: gcc warn when pointers not checked non-null before de-referencing.

[Segher Boessenkool <segher@kernel.crashing.org>]

On Sat, Jul 03, 2021 at 03:14:21PM +0100, Jonny Grant wrote:
> We'd rather have stability and logging of errors than a core dump. Especially on embedded systems that need to guarantee safety. It's easy enough to check for NULL and check the bounds of buffers etc before using. Asserts would trigger in a debug build.

There *is* no generic way you can sanely and even safely handle null
pointer dereferences at all.  You *have to* separately write code for
every place you want to do something special with null pointers (or any
other special case for that matter).

In case you are talking about a system with an event loop (or similar),
where you can just abort the task you are doing, and get back to waiting
for more work to do: you can just catch *all* fatal errors (which a null
dereference normally is), log it, and go back to the main loop.  But
even then the null dereference could be caused by something that is not
yet fixed.  If you are lucky other tasks can still be done.   OTOH,
perhaps just as often nothing will work anymore.

In any case, there is nothing the compiler can do for you here.  If
programming were a mechanical job, we wouldn't need all those pesky
programmers :-)


Segher