Re: "%m" formatting code and "syslog like"

[Roy Marples <roy%marples.name@localhost>]

On 31/08/2018 13:29, Martin Husemann wrote:
> On Fri, Aug 31, 2018 at 01:23:51PM +0100, Roy Marples wrote:
> > This allows dhcpcd to be compiled with full warnings, but I've disabled the
> > check for specific functions. This is actually self defeating as it's just
> > the kind of function the warnings are for, but as best I can tell it's
> > impossible to have your own logging function unless you either live with the
> > warnings or disable them - neither is a good solution really.
>
> Why would this not work?
>
> You do your own logging function and mark it __printflike, then avoid
> all (non portable) %m format strings by replacing them with %s and
> strerror().

None of the calls use %m or any non portable printf extensions.
It is my own logging function.

The function is currently marked as __printflike.
If I re-enable the warning gcc warns me that it should be marked as 
__sysloglike .... because it calls syslog. If I change it to 
__sysloglike then it warns me that it should be __printflike because it 
also uses vfprintf.

Feel free to write a patch or fix gcc. I've spent more time on this than 
I care already, so just happy to disbable the check.

Roy