From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:50072 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751562AbcABL7y (ORCPT ); Sat, 2 Jan 2016 06:59:54 -0500 Subject: Re: [PATCH] [RFC] um: define and use HAVE_LIBPCAP/HAVE_LIBVDEPLUG References: <1451701909-24430-1-git-send-email-vegard.nossum@oracle.com> <5687B7EA.9090605@nod.at> From: Vegard Nossum Message-ID: <5687BBAA.3020101@oracle.com> Date: Sat, 2 Jan 2016 12:59:38 +0100 MIME-Version: 1.0 In-Reply-To: <5687B7EA.9090605@nod.at> Content-Type: text/plain; charset=iso-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Richard Weinberger Cc: user-mode-linux-devel@lists.sourceforge.net, linux-kbuild@vger.kernel.org On 01/02/2016 12:43 PM, Richard Weinberger wrote: > Am 02.01.2016 um 03:31 schrieb Vegard Nossum: >> If you don't have libpcap or libvdeplug installed, you will get build >> failures when compiling certain files: >> >> arch/um/drivers/vde_user.c:8:24: fatal error: libvdeplug.h: No such file or directory >> #include >> >> arch/um/drivers/pcap_user.c:7:18: fatal error: pcap.h: No such file or directory >> #include >> >> This patch adds a basic pre-build check and defines the kconfig variables >> HAVE_LIBPCAP and HAVE_LIBVDEPLUG depending on the result. >> >> There is a basic disadvantage to this scheme, namely that the user may >> never see the options that rely on these libraries if they are not >> installed. As a trade-off, we add a brand new option, MISSING_LIBRARIES >> (defaulting to 'y'), which allows those options to be visible (and >> selectable) anyway. >> >> [Note: I find this useful personally as I ran into the above build >> failures when playing around with UML -- so take this more as a >> suggestion on how things MAY be done better than a real patch.] > > Why can't you build with UML_NET_VDE=n and UML_NET_PCAP=n > or install the missing libs? > To me the patch reads like a lazy approach to make allyesconfig somehow build. :-) > > If one selects VDE or PCAP (either manually or via allyesconfig) and the libs are > missing the build has to fail. Everything else will introduce nasty side effects > like having different builds with the same config and packagers will cry. Yeah, fair enough. Vegard