Re: [Cocci] coccinelle: Convert comma to semicolons (was Re: [PATCH] checkpatch: Add test for comma use that should be semicolon)

From: Joe Perches
Date: Sat Aug 22 2020 - 01:30:47 EST


On Fri, 2020-08-21 at 23:35 -0400, Valdis Klētnieks wrote:
> On Fri, 21 Aug 2020 18:08:08 -0700, Joe Perches said:
> > (forwarding on to kernel-janitors/mentees and kernelnewbies)
> >
> > Just fyi for anyone that cares:
> >
> > A janitorial task for someone might be to use Julia's coccinelle
> > script below to convert the existing instances of commas that
> > separate statements into semicolons.
>
> Note that you need to *really* check for possible changes in semantics.
> It's *usually* OK to do that, but sometimes it's not...
>
> for (i=0; i++, last++; !last) {
>
> changing that comma to a ; will break the compile. In other cases, it can
> introduce subtle bugs.

True enough for a general statement, though the coccinelle
script Julia provided does not change a single instance of
for loop expressions with commas.

As far as I can tell, no logic defect is introduced by the
script at all.