From: "Morten Brørup" <mb@smartsharesystems.com>
To: "Tyler Retzlaff" <roretzla@linux.microsoft.com>,
"Bruce Richardson" <bruce.richardson@intel.com>
Cc: "Stephen Hemminger" <stephen@networkplumber.org>, <dev@dpdk.org>
Subject: RE: [RFC 0/2] Eliminate zero length arrays in DPDK
Date: Thu, 24 Feb 2022 22:51:31 +0100 [thread overview]
Message-ID: <98CBD80474FA8B44BF855DF32C47DC35D86EF2@smartserver.smartshare.dk> (raw)
In-Reply-To: <20220217074139.GA1815@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net>
> From: Tyler Retzlaff [mailto:roretzla@linux.microsoft.com]
> Sent: Thursday, 17 February 2022 08.42
>
> On Wed, Feb 16, 2022 at 10:10:01AM +0000, Bruce Richardson wrote:
> > On Wed, Feb 16, 2022 at 11:05:09AM +0100, Morten Brørup wrote:
> > > > From: Bruce Richardson [mailto:bruce.richardson@intel.com]
> > > > Sent: Wednesday, 16 February 2022 10.33
> > > >
> > > > On Tue, Feb 15, 2022 at 03:00:56PM -0800, Stephen Hemminger
> wrote:
> > > > > Yet another case of applying Linux kernel best practices
> > > > > to DPDK. Flexible arrays are supported by Clang, GCC and
> > > > > Microsoft compilers (part of C99).
> > > > >
> > > > Do we need to start explicitly stating that DPDK uses C99
> features, and
> > > > adding -std=c99 to our build flags? Are we also requiring that
> > > > applications
> > > > are compiled with c99 features to use this (I would hope that
> they are,
> > > > but
> > > > I'm not sure we can mandate it).
> > >
> > > No to -std=c99. It's >= C99 for applications; we should not prevent
> them from using a newer C standard.
> >
> > Yes. For build flags, I was referring only to having it in the cflags
> for the
> > build of DPDK itself, not for apps. We definitely need to minimise
> the
> > build flags we expose to apps.
> >
> > >
> > > Adding a note about the C standard version to the DPDK requirements
> > > documentation would be very nice. It only mentions a certain
> compiler
> > > version required. But I think that documenting the detailed build
> and
> > > runtime requirements (and why they are that way) is another task.
> > >
> > Sure, we should do that. I am just wanting to be sure that if we
> specify a
> > minimum of C99, we won't get complaints back from those with legacy
> > codebasees which only support C89/C90. I am therefore wondering if we
> need
> > to have our public headers C90-compliant?
>
> this seems to be the real question. what "minimum" C standard should be
> documented as required to consume dpdk. we can obviously use any
> standard
> we wish to build/provide binaries. similarly we ought to document a
> minimum C++ standard for consumption.
>
> i would advocate for C99 however before setting that in stone it is
> fair
> to ask if there are any consumers using < C99.
>
> we may also want to consider that the minimum required may differ
> depending on the platform/port. though most differences in public
> interface
> i would hope could be trivially abstracted though.
>
> ty
Just read that the Linux kernel is moving towards C11, or at minimum C99, for version 5.18:
https://lwn.net/SubscriberLink/885941/01fdc39df2ecc25f/
Let's be bold and push for the same for DPDK! :-)
-Morten
next prev parent reply other threads:[~2022-02-24 21:51 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-15 23:00 Stephen Hemminger
2022-02-15 23:00 ` [RFC 1/2] devtools: add script to check for zero length array Stephen Hemminger
2022-02-15 23:00 ` [RFC 2/2] treewide: replace zero-length array with flex array Stephen Hemminger
2022-02-16 9:27 ` [RFC 0/2] Eliminate zero length arrays in DPDK Morten Brørup
2022-02-16 9:33 ` Bruce Richardson
2022-02-16 10:05 ` Morten Brørup
2022-02-16 10:10 ` Bruce Richardson
2022-02-17 7:41 ` Tyler Retzlaff
2022-02-24 21:51 ` Morten Brørup [this message]
2022-02-24 23:03 ` Stephen Hemminger
2022-02-16 18:56 ` Stephen Hemminger
2022-02-17 8:09 ` Tyler Retzlaff
2022-02-16 10:39 Morten Brørup
2022-02-17 8:32 ` Tyler Retzlaff
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