Re: [Qemu-devel] [PATCH 15/16] os-posix: cleanup: Replace perror with error_report

[Daniel P . Berrangé]

On Tue, Apr 24, 2018 at 03:53:48PM +0100, Ian Jackson wrote:
> Philippe Mathieu-Daudé writes ("Re: [Qemu-devel] [PATCH 15/16] os-posix: 
> cleanup: Replace perror with error_report"):
> > On 04/19/2018 01:45 PM, Ian Jackson wrote:
> > > -        perror("mlockall");
> > > +        error_report("mlockall: %s", strerror(errno));
> > >      }
> > >  
> > >      return ret;
> > 
> > Thinking loudly, maybe we can refactor as error_report_errno(const char
> > *desc)...
> 
> git-grep 'error_report.*errno' shows a lot of call sites that do
> something more exciting than const char *desc would support.
> 
> I think the right approach would be
> 
>  - static void vreport(report_type type, const char *fmt, va_list ap)
>  + static void vreport(report_type type, int errnoval, const char *fmt, 
> va_list ap)
> ...
>  +     if (errnoval >= 0) {
>  +         error_printf(": %s", strerror(errnoval);
>  +     }
> 
> and then add both
>   error_report_errno
>   error_vreport_errno
> with the obvious semantics.

That would be nice, because then we can make these two functions actually
use strerror_r() instead of strerror(), for thread safety on all platforms.

Regards,
Daniel
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