From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Jes Sorensen <jes.sorensen@gmail.com>, Kalle Valo <kvalo@codeaurora.org>
Cc: Joe Perches <joe@perches.com>,
Ulrich Kunitz <kune@deine-taler.de>,
"David S. Miller" <davem@davemloft.net>,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH][next] zd1211rw/zd_usb.h: Replace zero-length array with flexible-array member
Date: Tue, 10 Mar 2020 17:36:39 -0500 [thread overview]
Message-ID: <948ec681-c4ee-3479-8d8b-5aa1e358ec04@embeddedor.com> (raw)
In-Reply-To: <9700b2c9-1029-60b0-c5d2-684bdcede354@gmail.com>
On 3/10/20 5:34 PM, Jes Sorensen wrote:
> On 3/10/20 6:31 PM, Gustavo A. R. Silva wrote:
>>
>>
>> On 3/10/20 5:20 PM, Jes Sorensen wrote:
>>> On 3/10/20 6:13 PM, Gustavo A. R. Silva wrote:
>>>>
>>>>
>>>> On 3/10/20 5:07 PM, Jes Sorensen wrote:
>>>>> As I stated in my previous answer, this seems more code churn than an
>>>>> actual fix. If this is a real problem, shouldn't the work be put into
>>>>> fixing the compiler to handle foo[0] instead? It seems that is where the
>>>>> real value would be.
>>>>
>>>> Yeah. But, unfortunately, I'm not a compiler guy, so I'm not able to fix the
>>>> compiler as you suggest. And I honestly don't see what is so annoying/disturbing
>>>> about applying a patch that removes the 0 from foo[0] when it brings benefit
>>>> to the whole codebase.
>>>
>>> My point is that it adds what seems like unnecessary churn, which is not
>>> a benefit, and it doesn't improve the generated code.
>>>
>>
>> As an example of one of the benefits of this is that the compiler won't trigger
>> a warning in the following case:
>>
>> struct boo {
>> int stuff;
>> struct foo array[0];
>> int morestuff;
>> };
>>
>> The result of the code above is an undefined behavior.
>>
>> On the other hand in the case below, the compiles does trigger a warning:
>>
>> struct boo {
>> int stuff;
>> struct foo array[];
>> int morestuff;
>> };
>
> Right, this just underlines my prior argument, that this should be fixed
> in the compiler.
>
In the meantime it's not at all harmful to do something about it in the codebase.
Thanks
--
Gustavo
next prev parent reply other threads:[~2020-03-10 22:37 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-05 11:12 Gustavo A. R. Silva
2020-03-05 14:50 ` Kalle Valo
2020-03-05 15:20 ` Joe Perches
2020-03-05 16:10 ` Kalle Valo
2020-03-05 18:28 ` Gustavo A. R. Silva
2020-03-10 13:56 ` Kalle Valo
2020-03-10 21:52 ` Gustavo A. R. Silva
2020-03-10 22:07 ` Jes Sorensen
2020-03-10 22:13 ` Gustavo A. R. Silva
2020-03-10 22:15 ` Joe Perches
2020-03-10 22:21 ` Gustavo A. R. Silva
2020-03-10 22:28 ` Joe Perches
2020-03-10 22:33 ` Jes Sorensen
2020-03-10 22:41 ` Joe Perches
2020-03-10 22:46 ` Gustavo A. R. Silva
2020-03-10 22:33 ` Gustavo A. R. Silva
2020-03-10 22:20 ` Jes Sorensen
2020-03-10 22:31 ` Gustavo A. R. Silva
2020-03-10 22:34 ` Jes Sorensen
2020-03-10 22:36 ` Gustavo A. R. Silva [this message]
2020-03-23 16:46 ` Kalle Valo
2020-03-23 17:14 ` [PATCH][next] zd1211rw: " Kalle Valo
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=948ec681-c4ee-3479-8d8b-5aa1e358ec04@embeddedor.com \
--to=gustavo@embeddedor.com \
--cc=davem@davemloft.net \
--cc=jes.sorensen@gmail.com \
--cc=joe@perches.com \
--cc=keescook@chromium.org \
--cc=kune@deine-taler.de \
--cc=kvalo@codeaurora.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-wireless@vger.kernel.org \
--cc=netdev@vger.kernel.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
all inboxes | Powered by JetHome®