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

["Daniel P. Berrangé" <berrange@redhat.com>]

On Tue, Apr 24, 2018 at 10:43:09AM -0500, Eric Blake wrote:
> On 04/24/2018 10:40 AM, Eric Blake wrote:
> > On 04/24/2018 10:18 AM, Daniel P. Berrangé wrote:
> > 
> >>>  - 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.
> > 
> > Except that strerror_r() is a bear to use portably, given that glibc's
> > default declaration differs from the POSIX requirement (you can force
> > glibc to give you the POSIX version, but doing so causes you to lose
> > access to many other useful extensions).  It's rather telling that 'git
> > grep strerror_r' currently comes up empty.
> 
> That said, glib's g_strerror() may be suitable for this purpose,
> although we are currently using it only in tests/ivshmem-test.c.

Yes, that uses strerror_r internally, or strerror_s on Windows:

https://gitlab.gnome.org/GNOME/glib/blob/master/glib/gstrfuncs.c#L1236


Regards,
Daniel
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