Re: [PATCH] staging: greybus: eclose macro in a do - while loop

[Menna Mahmoud]

On ١١‏/٣‏/٢٠٢٣ ١٦:٣٦, Julia Lawall wrote:
> Menna,
>
> There is a typo in the subject line.
>
> On Sat, 11 Mar 2023, Menna Mahmoud wrote:
>
> > " ERROR: Macros with multiple statements should be enclosed in a do -
> > while loop"
> >
> > Reported by checkpath.
> >
> > do loop with the conditional expression set to a constant
> > value of zero (0).This creates a loop that
> > will execute exactly one time.This is a coding idiom that
> > allows a multi-line macro to be used anywhere
> > that a single statement can be used.
> >
> > So, enclose `gb_loopback_stats_attrs` macro in do - while (0) to
> > fix checkpath error
> The log message should focus on what is done and why.  The checkpatch
> warning text and the fact that the problem was detected using checkpatch
> is useful, but less, so it should come last, not first.
>
> Here, what is done is to enclose a sequence of statements in a macro
> definition in a do-while loop with a test expression 0.
>
> The reason why is to make it safe to use the sequence anywhere a single
> statement can be used.
>
> A period at the end of a sentence should be followed by some whitespace
> before starting the next sentence.
>
> julia


got it, thank you.


Menna

> > Signed-off-by: Menna Mahmoud <eng.mennamahmoud.mm@xxxxxxxxx>
> > ---
> >   drivers/staging/greybus/loopback.c | 10 ++++++----
> >   1 file changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c
> > index 1a61fce98056..e86d50638cb5 100644
> > --- a/drivers/staging/greybus/loopback.c
> > +++ b/drivers/staging/greybus/loopback.c
> > @@ -162,10 +162,12 @@ static ssize_t name##_avg_show(struct device *dev,		\
> >   }									\
> >   static DEVICE_ATTR_RO(name##_avg)
> >
> > -#define gb_loopback_stats_attrs(field)				\
> > -	gb_loopback_ro_stats_attr(field, min, u);		\
> > -	gb_loopback_ro_stats_attr(field, max, u);		\
> > -	gb_loopback_ro_avg_attr(field)
> > +#define gb_loopback_stats_attrs(field)					\
> > +	do { \
> > +		gb_loopback_ro_stats_attr(field, min, u);		\
> > +		gb_loopback_ro_stats_attr(field, max, u);		\
> > +		gb_loopback_ro_avg_attr(field);				\
> > +	} while (0)
> >
> >   #define gb_loopback_attr(field, type)					\
> >   static ssize_t field##_show(struct device *dev,				\
> > --
> > 2.34.1