Re: [PATCH 2/2] mdadm.c: fix compile error "switch condition has boolean value"

[Gioh Kim]

On Thu, Mar 30, 2017 at 08:38:35AM +1100, NeilBrown wrote:
> On Thu, Mar 30 2017, jes.sorensen@xxxxxxxxx wrote:
> 
> > Gioh Kim <gi-oh.kim@xxxxxxxxxxxxxxxx> writes:
> >> Remove a boolean expression in switch condition
> >> to prevent compile error of some compilers.
> >
> > Please be specific, which compile is unable to handle this?
> >
> >> Signed-off-by: Gioh Kim <gi-oh.kim@xxxxxxxxxxxxxxxx>
> >> ---
> >>  mdadm.c | 6 +++---
> >>  1 file changed, 3 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/mdadm.c b/mdadm.c
> >> index 08ddcab..a98a051 100644
> >> --- a/mdadm.c
> >> +++ b/mdadm.c
> >> @@ -1905,11 +1905,11 @@ static int misc_list(struct mddev_dev *devlist,
> >>  			rv |= SetAction(dv->devname, c->action);
> >>  			continue;
> >>  		}
> >> -		switch(dv->devname[0] == '/') {
> >> -			case 0:
> >> +		switch(dv->devname[0]) {
> >> +			default:
> >>  				mdfd = open_dev(dv->devname);
> >>  				if (mdfd >= 0) break;
> >> -			case 1:
> >> +			case '/':
> >>  				mdfd = open_mddev(dv->devname, 1);  
> >>  		}
> >>  		if (mdfd>=0) {
> >
> > While I agree the original code is ugly, I am not convinced your
> > replacement is a lot prettier.
> >
> 
> Maybe
> 
> 		if (dv->devname[0] == '/' ||
> 		    (mdfd = open_dev(dv->devname)) < 0)
> 				mdfd = open_mddev(dv->devname, 1);
> 
> ??
> NeilBrown

Yes, the initial version I thought was:

if (dev->devname[0] != '/')
    mdfd = open_dev(dv->devname);
if (dev->devname[0] == '/' || mdfd < 0)
    mdfd = open_mddev(dv->devname, 1);

But I thought you have a reason to use switch-case expression,
so I kept switch-case.
If you agree, I'll send v2 patch using if-expression.

-- 
Best regards,
Gi-Oh Kim
TEL: 0176 2697 8962