From: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
To: Bart Van Assche <bvanassche@acm.org>
Cc: Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org,
Damien Le Moal <damien.lemoal@opensource.wdc.com>,
Naohiro Aota <naohiro.aota@wdc.com>,
Johannes Thumshirn <jth@kernel.org>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Steven Rostedt <rostedt@goodmis.org>,
linux-sparse@vger.kernel.org
Subject: Re: [PATCH 51/51] fs/zonefs: Fix sparse warnings in tracing code
Date: Sun, 26 Jun 2022 11:58:14 +0200 [thread overview]
Message-ID: <20220626095814.7wtma47w4sph7dha@mail> (raw)
In-Reply-To: <3eed7994-8de2-324d-c373-b6f4289a2734@acm.org>
On Sat, Jun 25, 2022 at 05:44:54PM -0700, Bart Van Assche wrote:
> On 6/25/22 02:23, Christoph Hellwig wrote:
> > On Fri, Jun 24, 2022 at 12:57:56PM -0700, Bart Van Assche wrote:
> > > BTW, I discovered the code in the tracing infrastructure
> > > that makes sparse unhappy:
> > >
> > > #define is_signed_type(type) (((type)(-1)) < (type)1)
> > >
> > > Sparse reports four warnings for that expression if 'type' is a bitwise
> > > type. Two of these warnings can be suppressed by changing 'type' into
> > > '__force type'. I have not yet found a way to suppress all the sparse
> > > warnings triggered by the is_signed_type() macro for bitwise types.
Yes, __bitwise is quite strict and only support the bitwise operations
(&, |, ^ and).
> > Yeah, that is a bit of a mess. Rasmus, Steven - any good idea how
> > we can make the trace even macros fit for sparse? Maybe just drop the
> > is_signed_type check for __CHECKER__ ?
I would strongly advise against this:
-) the macro is sued elsewhere too (for overflow checking)
-) sparse wouldn't check anymore the same code as the one seen by the
compiler
What about I would add to sparse something to strip away the bitwise/
recover the underlying type? Something like __unbitwiseof() or
__underlying_typeof() (some better name is needed)?
Implementing directly what's needed here, something like __is_signed_type()
would be possible too but is a bit too specialized and so much less useful.
-- Luc Van Oostenryck
next parent reply other threads:[~2022-06-26 9:58 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220623180528.3595304-1-bvanassche@acm.org>
[not found] ` <20220623180528.3595304-52-bvanassche@acm.org>
[not found] ` <20220624045613.GA4505@lst.de>
[not found] ` <aa044f61-46f0-5f21-9b17-a1bb1ff9c471@acm.org>
[not found] ` <20220625092349.GA23530@lst.de>
[not found] ` <3eed7994-8de2-324d-c373-b6f4289a2734@acm.org>
2022-06-26 9:58 ` Luc Van Oostenryck [this message]
2022-06-26 15:42 ` [PATCH 51/51] fs/zonefs: Fix sparse warnings in tracing code Bart Van Assche
2022-06-26 16:24 ` Luc Van Oostenryck
2022-06-26 16:33 ` Linus Torvalds
2022-06-26 16:50 ` Linus Torvalds
2022-06-26 20:10 ` Luc Van Oostenryck
2022-06-26 19:44 ` Luc Van Oostenryck
2022-06-27 19:05 ` [PATCH 0/5] allow -1 and compares in bitwise types Luc Van Oostenryck
2022-06-27 19:05 ` [PATCH 1/5] bitwise: add testcases Luc Van Oostenryck
2022-06-27 19:05 ` [PATCH 2/5] bitwise: accept all ones as non-restricted value Luc Van Oostenryck
2022-06-27 23:32 ` Ramsay Jones
2022-06-27 19:05 ` [PATCH 3/5] bitwise: allow compares for bitwise types Luc Van Oostenryck
2022-06-27 19:20 ` Linus Torvalds
2022-06-27 23:34 ` Ramsay Jones
2022-06-27 19:05 ` [PATCH 4/5] bitwise: do not remove the signedness of " Luc Van Oostenryck
2022-06-27 19:05 ` [PATCH 5/5] bitwise: early expansion of simple constants Luc Van Oostenryck
2022-06-27 19:14 ` [PATCH 0/5] allow -1 and compares in bitwise types Linus Torvalds
2022-06-27 19:15 ` Bart Van Assche
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220626095814.7wtma47w4sph7dha@mail \
--to=luc.vanoostenryck@gmail.com \
--cc=axboe@kernel.dk \
--cc=bvanassche@acm.org \
--cc=damien.lemoal@opensource.wdc.com \
--cc=hch@lst.de \
--cc=jth@kernel.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-sparse@vger.kernel.org \
--cc=linux@rasmusvillemoes.dk \
--cc=naohiro.aota@wdc.com \
--cc=rostedt@goodmis.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).