From: David Marchand <david.marchand@redhat.com>
To: Bruce Richardson <bruce.richardson@intel.com>
Cc: Reshma Pattan <reshma.pattan@intel.com>, dev <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH] mk: disable warning with gcc 9 on Fedora 30
Date: Thu, 2 May 2019 15:30:51 +0200 [thread overview]
Message-ID: <CAJFAV8wbOQ3jYZqnsKFwHKrAvrJp0qQu6o-x=tvRcWAX--qqxg@mail.gmail.com> (raw)
In-Reply-To: <20190502132630.GD1980@bricha3-MOBL.ger.corp.intel.com>
On Thu, May 2, 2019 at 3:26 PM Bruce Richardson <bruce.richardson@intel.com>
wrote:
> On Thu, May 02, 2019 at 12:07:17PM +0200, David Marchand wrote:
> > On Thu, May 2, 2019 at 11:33 AM Reshma Pattan <reshma.pattan@intel.com>
> > wrote:
> >
> > > gcc 9 on Fedora 30 gives an error
> > > "taking address of packed member may result in an
> > > unaligned pointer value" warnings.
> > >
> > > For clang builds this warning is already disabled,
> > > so disable "-Waddress-of-packed-member" for gcc builds
> > > also.
> > >
> > > Snippet of build error:
> > > ...lib/librte_eal/linux/eal/eal_memalloc.c: In function
> ‘alloc_seg_walk’:
> > > ...lib/librte_eal/linux/eal/eal_memalloc.c:768:12: error: taking
> address
> > > of packed member of ‘struct rte_mem_config’ may result in an unaligned
> > > pointer value [-Werror=address-of-packed-member]
> > > 768 | cur_msl = &mcfg->memsegs[msl_idx];
> > > | ^~~~~~~~~~~~~~~~~~~~~~~
> > >
> > > Signed-off-by: Reshma Pattan <reshma.pattan@intel.com>
> > > ---
> > > mk/toolchain/gcc/rte.vars.mk | 3 +++
> > > 1 file changed, 3 insertions(+)
> > >
> > > diff --git a/mk/toolchain/gcc/rte.vars.mk b/mk/toolchain/gcc/
> rte.vars.mk
> > > index d8b99faf6..b852fcfd7 100644
> > > --- a/mk/toolchain/gcc/rte.vars.mk
> > > +++ b/mk/toolchain/gcc/rte.vars.mk
> > > @@ -87,5 +87,8 @@ WERROR_FLAGS += -Wimplicit-fallthrough=2
> > > WERROR_FLAGS += -Wno-format-truncation
> > > endif
> > >
> > > +# disable packed member unalign warnings
> > > +WERROR_FLAGS += -Wno-address-of-packed-member
> > > +
> > > export CC AS AR LD OBJCOPY OBJDUMP STRIP READELF
> > > export TOOLCHAIN_CFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS
> > > --
> > > 2.21.0
> > >
> > >
> > Not the best approach to me...
> >
> Agreed, but this fix does seem reasonable since we already disable this
> warning
> for clang.
>
> > Let me install a fedora 30 and have a look.
> Hopefully you can come up with a better fix, but I think we need something
> soon for 19.05, so this patch may be needed as a stop-gap fix.
>
Hiding this warning, we will never fix the places that could be fixed (and
I found some where the packed attribute makes no sense to me).
I'd prefer at least a -Wno-error=address-of-packed-member
--
David Marchand
next prev parent reply other threads:[~2019-05-02 13:31 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-02 9:33 Reshma Pattan
2019-05-02 9:33 ` Reshma Pattan
2019-05-02 10:07 ` David Marchand
2019-05-02 10:07 ` David Marchand
2019-05-02 13:26 ` Bruce Richardson
2019-05-02 13:26 ` Bruce Richardson
2019-05-02 13:30 ` David Marchand [this message]
2019-05-02 13:30 ` David Marchand
2019-05-02 13:35 ` Pattan, Reshma
2019-05-02 13:35 ` Pattan, Reshma
2019-05-02 14:13 ` [dpdk-dev] [PATCH v2] mk: report address of packed member as warning Reshma Pattan
2019-05-02 14:13 ` Reshma Pattan
2019-05-02 14:24 ` David Marchand
2019-05-02 14:24 ` David Marchand
2019-05-02 14:41 ` Bruce Richardson
2019-05-02 14:41 ` Bruce Richardson
2019-05-02 14:48 ` David Marchand
2019-05-02 14:48 ` David Marchand
2019-05-02 15:53 ` Burakov, Anatoly
2019-05-02 15:53 ` Burakov, Anatoly
2019-05-02 18:54 ` Stephen Hemminger
2019-05-02 18:54 ` Stephen Hemminger
2019-05-03 7:56 ` Burakov, Anatoly
2019-05-03 7:56 ` Burakov, Anatoly
2019-05-02 15:00 ` [dpdk-dev] [PATCH] mk: disable warning with gcc 9 on Fedora 30 David Marchand
2019-05-02 15:00 ` David Marchand
2019-05-02 15:56 ` Thomas Monjalon
2019-05-02 15:56 ` Thomas Monjalon
2019-05-03 16:01 ` Jerin Jacob Kollanukkaran
2019-05-03 16:01 ` Jerin Jacob Kollanukkaran
2019-05-03 16:25 ` Bruce Richardson
2019-05-03 16:25 ` Bruce Richardson
2019-05-03 16:28 ` Richardson, Bruce
2019-05-03 16:28 ` Richardson, Bruce
2019-05-03 17:24 ` [dpdk-dev] [EXT] " Jerin Jacob Kollanukkaran
2019-05-03 17:24 ` Jerin Jacob Kollanukkaran
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='CAJFAV8wbOQ3jYZqnsKFwHKrAvrJp0qQu6o-x=tvRcWAX--qqxg@mail.gmail.com' \
--to=david.marchand@redhat.com \
--cc=bruce.richardson@intel.com \
--cc=dev@dpdk.org \
--cc=reshma.pattan@intel.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 NNTP newsgroup(s).