Warning for different pointer signedness

[Andrew Pinski]

On Dec 20, 2004, at 3:47 PM, Paul Schlie wrote:

>> From: Andrew Pinski <pinskia@physics.uc.edu>
>> Wrong, wrong, wrong, the change only moved a warning from -pedantic
>> to always on, in fact some compilers reject the code as it is invalid 
>> c.
>>
>> -- Pinski
>
> Which seems odd given (signed xxx *) and (unsigned xxx *) will always 
> be
> guaranteed to be pointers to the exact same size and aligned storage 
> units;
> (therefore at best, seems like a mistake to consider them incompatible
> objects for the purpose of comparison, as no possible ambiguity 
> exists).

The warning is only there for an implicit conversions nothing else, if 
you
add a cast it will not warn.  Well this is what the C standard say so
you are wrong again.

6.3.2.3 describes the conversions.  Again this is invalid C (and C++ in
fact) so a warning is correct.

The only implicit conversion for pointers in C is to and from void*.

-- Pinski