DPDK patches and discussions
 help / color / mirror / Atom feed
From: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
To: Thomas Monjalon <thomas@monjalon.net>
Cc: dev@dpdk.org, bruce.richardson@intel.com, bluca@debian.org,
	olivier.matz@6wind.com, thierry.herbelot@6wind.com,
	Gabriel Ganne <gabriel.ganne@6wind.com>,
	stable@dpdk.org, Harry van Haaren <harry.van.haaren@intel.com>,
	Luca Boccassi <luca.boccassi@gmail.com>,
	Keith Wiles <keith.wiles@intel.com>,
Subject: Re: [dpdk-dev] [PATCH v5] build: remove redundant libpcap link
Date: Thu, 15 Apr 2021 00:02:45 +0300	[thread overview]
Message-ID: <20210415000245.0b1d45c1@sovereign> (raw)
In-Reply-To: <3119483.LeJDoi8FaI@thomas>

2021-04-14 11:41 (UTC+0200), Thomas Monjalon:
> 09/04/2021 14:25, Thomas Monjalon:
> > From: Gabriel Ganne <gabriel.ganne@6wind.com>
> > 
> > The pcap PMD and the librte_port both declare their dependency to libpcap
> > with a line "ext_deps += pcap_dep".
> > Then meson automatically adds this dependency to the pkg-config file
> > in the "Requires.private" section for static builds.
> > 
> > The additional update of dpdk_extra_ldflags was adding the dependency
> > in the "Libs.private" section of the pkg-config, that is unnecessary.
> > 
> > Fixes: efd5d1a8d8dd ("drivers/net: build some vdev PMDs with meson")
> > Fixes: 268fa581b1ff ("port: fix pcap support with meson")
> > Cc: stable@dpdk.org
> > 
> > Signed-off-by: Gabriel Ganne <gabriel.ganne@6wind.com>
> > Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> > ---
> > I have a doubt whether this option is really always useless.
> > In the case of an old pcap (<1.9) without pkg-config support,
> > and with the minimum meson supported (0.47.1),
> > are we sure the generated pkg-config file will include -lpcap?  
> Any volunteer to test please?

Ubuntu 16.04, Meson 0.47.1, libpcap 1.7.4-2ubuntu0.1, after the patch
libdpdk.pc contains:

	Libs.private: -lpcap -lpcap -lpcap -lpcap -lpcap -lpcap -lpcap -lpcap
	-lpcap -lpcap [...DPDK libraries...]

Note that -lpcap comes _before_ DPDK libraries that require it.
As a consequence, this doesn't link with unresolved libpcap symbols:

	gcc test.c `pkg-config --static --cflags --libs libdpdk`

Before the patch -lpcap was _after_ DPDK libraries,
link succeeded (there was also _one_ -lpcap before DPDK libraries).

Meson 0.55.1 places -lpcap _after_ DPDK libraries,
link succeeds both before and after the patch.

Conclusion: this patch really breaks .pc file for older meson.
If it can't be merged, dependent patches for net/pcap on Windows
can be easily adjusted to work without it.

  reply	other threads:[~2021-04-14 21:02 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-22 14:07 [dpdk-dev] [PATCH v2 2/3] meson: use threads dependency as provided by meson Gabriel Ganne
2021-03-22 14:07 ` [dpdk-dev] [PATCH v2 3/3] meson: remove unnecessary explicit link to libpcap Gabriel Ganne
2021-04-09  8:39   ` [dpdk-dev] [PATCH v4] " Gabriel Ganne
2021-04-09 12:25     ` [dpdk-dev] [PATCH v5] build: remove redundant libpcap link Thomas Monjalon
2021-04-14  9:41       ` Thomas Monjalon
2021-04-14 21:02         ` Dmitry Kozlyuk [this message]
2021-04-14 21:10           ` Thomas Monjalon
2023-07-16 17:19             ` Stephen Hemminger
2023-07-16 17:21     ` [dpdk-dev] [PATCH v4] meson: remove unnecessary explicit link to libpcap Stephen Hemminger
2021-03-22 16:04 ` [dpdk-dev] [PATCH v2 2/3] meson: use threads dependency as provided by meson Nick Connolly
2021-03-22 22:18   ` Dmitry Kozlyuk
2021-03-23 13:35     ` Nick Connolly
2021-03-23 21:21       ` Dmitry Kozlyuk
2021-03-23 22:17         ` Nick Connolly
2021-03-24  6:35           ` Gabriel Ganne

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:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210415000245.0b1d45c1@sovereign \
    --to=dmitry.kozliuk@gmail.com \
    --cc=bluca@debian.org \
    --cc=bruce.richardson@intel.com \
    --cc=david.marchand@redhat.com \
    --cc=dev@dpdk.org \
    --cc=gabriel.ganne@6wind.com \
    --cc=harry.van.haaren@intel.com \
    --cc=keith.wiles@intel.com \
    --cc=luca.boccassi@gmail.com \
    --cc=olivier.matz@6wind.com \
    --cc=stable@dpdk.org \
    --cc=thierry.herbelot@6wind.com \
    --cc=thomas@monjalon.net \


* 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).