From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 54671A0350; Wed, 1 Jul 2020 16:42:39 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id AF0C81D16D; Wed, 1 Jul 2020 16:42:38 +0200 (CEST) Received: from wout5-smtp.messagingengine.com (wout5-smtp.messagingengine.com [64.147.123.21]) by dpdk.org (Postfix) with ESMTP id 513B31C224 for ; Wed, 1 Jul 2020 16:42:37 +0200 (CEST) Received: from compute7.internal (compute7.nyi.internal [10.202.2.47]) by mailout.west.internal (Postfix) with ESMTP id DCAB144A; Wed, 1 Jul 2020 10:42:35 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute7.internal (MEProxy); Wed, 01 Jul 2020 10:42:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding:content-type; s=fm1; bh= EMOwUHAmjb3HVxxpHKzLD01YNUPebMtd920Is43dCWk=; b=qBBZAUMXgGRsDuBL 1iwaUj0GB1Qa917df5TR1WNExPIyC0iGiQgfeYwPbmXXxXBS+xvsQpfQsUP9i/VG boZ1hvZybPipmSyhZcQJKukLHzu2gg8SwqBD+Hr1E6CTKl7IbBRdcUhPa9veNIHN esc8orENFnNqne2m+x25ZkawmORMGXqRrSVzLM8bx4FweXdteUk4CGkFWsee24yp Gr68ZW4oIkOH/1XbVae+qCMGI/86MM1uxEU56/UMT2ngsygHAAgIEsn7kx+ccW5K ZluLZcmDpvB0+xQAmhX6OBStCmf6lln9La8CVHM9/HUTMeYzvktsOuizD1JC4fdm JyeDqw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm3; bh=EMOwUHAmjb3HVxxpHKzLD01YNUPebMtd920Is43dC Wk=; b=YCqOM32tvUaK3pU5SGL+e8+J8VQJGTFO3arDWDwwAmrVnADDPgetXKXmq JPhGcaD9K/BwIyNWb24KaAVKUvtJIAFf42cn72kvrBjM1/289OVcnTvIW7ic9CEV afshM2RXYr+umn5Epc7IMEuOfGjCH4BQZ/uaDVXKCUTUUP8SXyToJwATfyK5Y47u dYs1UscBWzdBYNyn5NLN0i8XgqLjc6nl8t270CD+cDRPkMyQoELbs4S+RDSYJMp5 xiJjwmmWCzuyuH8np9FxlbBjhmJQgf60IMl2WY2oufpGFrsiJUvVB8vBBv8pWZJs tQ1N9wfuap+CpAHb9lAHfNveqIi/Q== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduiedrtddvgdekudcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefhvffufffkjghfggfgtgesthfuredttddtvdenucfhrhhomhepvfhhohhmrghs ucfoohhnjhgrlhhonhcuoehthhhomhgrshesmhhonhhjrghlohhnrdhnvghtqeenucggtf frrghtthgvrhhnpedugefgvdefudfftdefgeelgffhueekgfffhfeujedtteeutdejueei iedvffegheenucfkphepjeejrddufeegrddvtdefrddukeegnecuvehluhhsthgvrhfuih iivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepthhhohhmrghssehmohhnjhgrlhho nhdrnhgvth X-ME-Proxy: Received: from xps.localnet (184.203.134.77.rev.sfr.net [77.134.203.184]) by mail.messagingengine.com (Postfix) with ESMTPA id 3CE3E328005A; Wed, 1 Jul 2020 10:42:34 -0400 (EDT) From: Thomas Monjalon To: Bruce Richardson Cc: dev@dpdk.org, david.marchand@redhat.com, ktraynor@redhat.com, bluca@debian.org, sunil.pai.g@intel.com Date: Wed, 01 Jul 2020 16:42:33 +0200 Message-ID: <7587667.Wdl7rU7Jnr@thomas> In-Reply-To: <20200630141433.818517-6-bruce.richardson@intel.com> References: <20200429100831.398-1-bruce.richardson@intel.com> <20200630141433.818517-1-bruce.richardson@intel.com> <20200630141433.818517-6-bruce.richardson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [dpdk-dev] [PATCH v3 5/7] build/pkg-config: output driver libs first for static build X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 30/06/2020 16:14, Bruce Richardson: > When calling pkg-config --static --libs, pkg-config will always output the > regular libs first, and then the extra libs from libraries.private field, s/libraries.private/Libs.private/ > since the assumption is that those are additional dependencies for building > statically that the .a files depend upon. > > However, for DPDK, we only link the driver files for static builds, and > those need to come *before* the regular libraries. To get this result, we > need two pkgconfig files for DPDK, one for the shared libs, and a second > for the static libs and drivers, which depends upon the first. Using a > dependency means that the shared libs are printed only after the > libraries.private field rather than before. s/libraries.private/Libs.private/ > Without this patch, the linking works in DPDK because in all cases we > specify the libraries after the drivers in the Libs.private line, ensuring > that the references to the libs from the drivers can be resolved. The > current output is therefore of the form, "(shared)libs, drivers, > (static)libs", while after this patch the output is, "drivers, > (static)libs, (shared)libs". The former case will not work if we use the > --whole-archive flag on the static libs as it will lead to duplicate > definitions due to some references having been previously resolved from the > shared libraries. By ensuring the shared libraries come last in the link > link, this issue does not occur, as duplicate references when linking the > shared libs will be ignored. > > Signed-off-by: Bruce Richardson > Acked-by: Luca Boccassi > Acked-by: Sunil Pai G > --- > +# When calling pkg-config --static --libs, pkg-config will always output the > +# regular libs first, and then the extra libs from libraries.private field, > +# since the assumption is that those are additional dependencies for building > +# statically that the .a files depend upon. However, for DPDK, we only link > +# the driver files for static builds, and those need to come *before* the > +# regular libraries. To get this result, we need two pkgconfig files for DPDK, > +# one for the shared libs, and a second for the static libs and drivers, which > +# depends upon the first. Using a dependency means that the shared libs are > +# printed only after the libraries.private field rather than before. This is not obvious. In order to avoid messing it up in future, I suggest this longer reword: # When calling pkg-config --static --libs, pkg-config will always output the # regular libs first, and then the extra libs from Libs.private field, # since the assumption is that those are additional dependencies for building # statically that the .a files depend upon. The output order of .pc fields is: # Cflags Libs Libs.private Requires Requires.private # The fields Requires* are for package names. # The flags of the DPDK libraries must be defined in Libs* fields. # However, the DPDK drivers are linked only in static builds (Libs.private), # and those need to come *before* the regular libraries (Libs field). # This requirement is satisfied by moving the regular libs in a separate file # included in the field Requires (after Libs.private). # Another requirement is to allow linking dependencies as shared libraries, # while linking static DPDK libraries and drivers. It is satisfied by # listing the static files in Libs.private with the explicit syntax -l:libfoo.a. # As a consequence, the regular DPDK libraries are already listed as static # in the field Libs.private. The second occurences of DPDK libraries, # included from Requires and used for shared library linkage case, # are skipped in the case of static linkage thanks to the flag --as-needed. # Link order summary: # libdpdk.Libs.private: whole-archive(static drivers/libs), drivers deps flags # libdpdk.Requires: libdpdk-libs package # libdpdk-libs.Libs: as-needed(shared libs) # libdpdk-libs.Libs.private: libs deps flags # libdpdk.pc.Requires.private: deps packages If you agree, I could change this comment while merging. I would add my Signed-off ;)