From: Ryan Roberts <ryan.roberts@arm.com>
To: John Hubbard <jhubbard@nvidia.com>, Shuah Khan <shuah@kernel.org>
Cc: "Andrew Morton" <akpm@linux-foundation.org>,
"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>,
"Maciej Wieczor-Retman" <maciej.wieczor-retman@intel.com>,
"Christian Brauner" <brauner@kernel.org>,
"Muhammad Usama Anjum" <usama.anjum@collabora.com>,
"Alexey Gladkov" <legion@kernel.org>,
"Valentin Obst" <kernel@valentinobst.de>,
linux-kselftest@vger.kernel.org,
LKML <linux-kernel@vger.kernel.org>,
llvm@lists.linux.dev
Subject: Re: [PATCH 1/2] selftests/openat2: fix clang build failures: -static-libasan, LOCAL_HDRS
Date: Tue, 7 May 2024 17:56:39 +0100 [thread overview]
Message-ID: <1f8711d2-8505-4685-9e0f-180bdc709381@arm.com> (raw)
In-Reply-To: <c1ff82e6-4d6a-4680-925f-5f0226ba32c4@nvidia.com>
On 07/05/2024 17:47, John Hubbard wrote:
> On 5/7/24 9:34 AM, Ryan Roberts wrote:
>> On 07/05/2024 17:19, John Hubbard wrote:
>>> On 5/7/24 12:45 AM, Ryan Roberts wrote:
>>>> On 04/05/2024 05:43, John Hubbard wrote:
>>> ...
>>>> Hi John,
>>>>
>>>> I sent out a similar fix a couple of weeks ago, see [1]. I don't think it got
>>>> picked up though. It takes a slightly different approach, explicitly adding
>>>> -static-libsan (note no 'a') for clang, instead of relying on its default.
>>>>
>>>> And it just drops helpers.h from the makefile altogether, on the assumption
>>>> that
>>>> it was a mistake; its just a header and shouldn't be compiled directly. I'm not
>>>> exactly sure what the benefit of adding it to LOCAL_HDRS is?
>>>
>>> Ah no, you must not drop headers.h. That's a mistake itself, because
>>> LOCAL_HDRS adds a Make dependency; that's its purpose. If you touch
>>> helpers.h it should cause a rebuild, which won't happen if you remove it
>>> from LOCAL_HDRS.
>>
>> Ahh. I was under the impression that the compiler was configured to output the
>> list of dependencies for make to track (something like -M, from memory ?). Since
>> helpers.h is included from helpers.c I assumed it would be tracked like this - I
>> guess its not that simple?
>
> This can be done, but it is not automatic with GNU Make. You have to explicitly
> run gcc -M, capture the output in a dependencies list, and track it. Which the
> Kbuild system does, but kselftest does not.
Understood - thanks for the lesson!
>
> After just now sweeping through kselftest to fix up the clang build, I see a
> lot of mistaken or partial use of the kselftest build's Make variables, because
> people naturally reason based on what they know about Kbuild, and it doesn't
> always translate. And LOCAL_HDRS might need some more documentation too.
> I'll keep thinking about how to clarify this, I have a couple early ideas.
>
>>
>> Anyway, on the basis that LOCAL_HDRS is the right way to do this, let's go with
>> your version and drop mine:
>>
>> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
>>
>
> Thanks for the review!
>
> thanks,
next prev parent reply other threads:[~2024-05-07 16:56 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-04 4:43 [PATCH 1/2] selftests/openat2: fix clang build failures: -static-libasan, LOCAL_HDRS John Hubbard
2024-05-04 4:43 ` [PATCH 2/2] selftests/fchmodat2: fix clang build failure due to -static-libasan John Hubbard
2024-05-07 7:45 ` [PATCH 1/2] selftests/openat2: fix clang build failures: -static-libasan, LOCAL_HDRS Ryan Roberts
2024-05-07 16:19 ` John Hubbard
2024-05-07 16:34 ` Ryan Roberts
2024-05-07 16:47 ` John Hubbard
2024-05-07 16:56 ` Ryan Roberts [this message]
2024-05-10 11:52 ` Ryan Roberts
2024-05-10 17:56 ` John Hubbard
2024-05-10 18:22 ` John Hubbard
2024-05-11 17:19 ` Ryan Roberts
2024-05-30 3:58 ` Muhammad Usama Anjum
2024-05-30 4:35 ` John Hubbard
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=1f8711d2-8505-4685-9e0f-180bdc709381@arm.com \
--to=ryan.roberts@arm.com \
--cc=akpm@linux-foundation.org \
--cc=brauner@kernel.org \
--cc=ilpo.jarvinen@linux.intel.com \
--cc=jhubbard@nvidia.com \
--cc=kernel@valentinobst.de \
--cc=legion@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=llvm@lists.linux.dev \
--cc=maciej.wieczor-retman@intel.com \
--cc=shuah@kernel.org \
--cc=usama.anjum@collabora.com \
/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).