More C type errors by default for GCC 14

[Florian Weimer]

* Jakub Jelinek:

> On Tue, May 16, 2023 at 01:39:26PM +0300, Alexander Monakov wrote:
>> 
>> On Tue, 16 May 2023, Florian Weimer wrote:
>> 
>> > > (FWIW: no, this should not be an error, a warning is fine, and I actually 
>> > > think the current state of it not being in Wall is the right thing as 
>> > > well)
>> 
>> (this is mixed up, -Wpointer-sign is in fact enabled by -Wall)
>> 
>> > I don't understand why we do not warn by default and warn with -Wall.  I
>> > would expect this to be either a documented extension (no warning with
>> > -Wall), or a warning by default (because it's a conformance issue).  Is
>> > there any conformance issue that is treated in the same way?
>> 
>> Another one is -Wpointer-arith (pointer arithmetic on 'void *').
>
> That is a documented GNU extension, so we shouldn't increase severity of
> the diagnostics from the current state.

Right, it's also widely used, and harmless for void *.  For function
pointers, it's much more dubious, and not meaningful at all for some
targets.

Thanks,
Florian