lkml.org 
[lkml]   [2023]   [May]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2 5/5] 9p: remove dead stores (variable set again without being read)
Christian Schoenebeck wrote on Wed, May 03, 2023 at 10:22:46AM +0200:
> On Wednesday, May 3, 2023 9:49:29 AM CEST Dominique Martinet wrote:
> > The 9p code for some reason used to initialize variables outside of the
> > declaration, e.g. instead of just initializing the variable like this:
> >
> > int retval = 0
> >
> > We would be doing this:
> >
> > int retval;
> > retval = 0;
>
> OK, but AFAICS this patch would simply remove all initializations. I would
> expect at least a default initialization at variable declaration instead.

Yes, clang doesn't seem to complain about 'int reval = 0' so the patch
can just be updated to do that instead; I just removed them because the
sheer number made it faster to do that.
Happy to drop this last patch for now and rework it when time permits.

> > This is perfectly fine and the compiler will just optimize dead stores
> > anyway, but scan-build seems to think this is a problem and there are
> > many of these warnings making the output of scan-build full of such
> > warnings:
> > fs/9p/vfs_inode.c:916:2: warning: Value stored to 'retval' is never read [deadcode.DeadStores]
> > retval = 0;
> > ^ ~
>
> Honestly I don't see much value in this warning. Can't we just disable this
> warning for 9p code or is this just controllable for the entire project?

Dead stores in itself is a useful warning, it's what found the real bug
where return value was lost in patch 1 of this series, I don't think we
should just disable the warning.

--
Dominique Martinet | Asmadeus

\
 
 \ /
  Last update: 2023-05-03 10:45    [W:0.057 / U:0.472 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site