On 5/12/23 19:52, Florian Weimer wrote:
> * Florian Weimer:
>
>> In summary, all these seems to be good candidates for errors by default:
>>
>> * int-conversion as errors (already raised separately
>> * -Wint-conversion for ?:
>> * parameter names in non-prototype function declarations
>> * the union wait function pointer compatibility kludge
>> * return-with-out-value for non-void functions
>> * -Wincomatible-pointer-types warning for ?: (but no error yet, see below)
> I think we have another problem.
>
> We do not warn by default for:
>
>    int x;
>    unsigned *p;
>
>    p = &x;
>
> Isn't that a conformance issue because the pointers are incompatible,
> requiring a diagnostic?
>
> Furthermore, Unlike the char case, this tends to introduce
> strict-aliasing violations, so there is a good reason to treat this
> variant as an error (even if we would only warn for char * and
> unsigned char *).

Isn't this allowed by the standard ? 6.5.7. Expressions states:
 > An object shall have its stored value accessed only by an lvalue 
expression that has one of thefollowing types:[...] - a type that is the 
signed or unsigned type corresponding to the effective type of the object