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Message-ID: <ZFIe7dLEncWN5YaQ@codewreck.org> Date: Wed, 3 May 2023 17:44:29 +0900 From: Dominique Martinet <asmadeus@...ewreck.org> To: Christian Schoenebeck <linux_oss@...debyte.com> Cc: Eric Van Hensbergen <ericvh@...il.com>, Latchesar Ionkov <lucho@...kov.net>, "David S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, Simon Horman <simon.horman@...igine.com>, v9fs@...ts.linux.dev, linux-kernel@...r.kernel.org, netdev@...r.kernel.org Subject: Re: [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
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