Re: [Qemu-devel] [PATCH] linux-user: fix convertion of flock/flock64 l_type field

[Eric Blake]

On 05/08/2018 12:08 PM, Max Filippov wrote:
> On Tue, May 8, 2018 at 9:36 AM, Laurent Vivier <address@hidden> wrote:

In the subject, s/convertion/conversion/

> > As l_type values (F_RDLCK, F_WRLCK, F_UNLCK, F_EXLCK, F_SHLCK)
> > are not bitmasks, we can't use target_to_host_bitmask() and
> > host_to_target_bitmask() to convert them.
> >
> > Introduce target_to_host_flock() and host_to_target_flock()
> > to convert values between host and target.

> > +static unsigned int host_to_target_flock(unsigned int type)
> > +{
> > +    switch (type) {
> > +#define TRANSTBL_CONVERT(a) case a: return TARGET_##a;
> > +    TRANSTBL_CONVERT(F_RDLCK)
> > +    TRANSTBL_CONVERT(F_WRLCK)
> > +    TRANSTBL_CONVERT(F_UNLCK)
> > +    TRANSTBL_CONVERT(F_EXLCK)
> > +    TRANSTBL_CONVERT(F_SHLCK)
> > +#undef  TRANSTBL_CONVERT
> > +    }
> > +    return type;
> > +}
>
> There's a duplication. Wouldn't it be better if it was done like the following:
>
> #define FLOCK_TRANSTBL \
>      switch (type) {
>      TRANSTBL_CONVERT(F_RDLCK) \

If you do this, I'd lean towards omitting the trailing ; from 
TRANSTBL_CONVERT() and sticking it in FLOCK_TRANSTBL instead (it looks 
weird to see a statement-like macro called without a ';').

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org