From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55572) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZUcqv-0001sB-2w for qemu-devel@nongnu.org; Wed, 26 Aug 2015 11:43:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZUcqt-0004YL-MK for qemu-devel@nongnu.org; Wed, 26 Aug 2015 11:43:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54137) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZUcqt-0004YH-Hg for qemu-devel@nongnu.org; Wed, 26 Aug 2015 11:43:03 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id 38C1A8CF63 for ; Wed, 26 Aug 2015 15:43:03 +0000 (UTC) Date: Wed, 26 Aug 2015 16:42:59 +0100 From: "Daniel P. Berrange" Message-ID: <20150826154259.GO21787@redhat.com> References: <1440601524-30316-1-git-send-email-berrange@redhat.com> <1440601524-30316-3-git-send-email-berrange@redhat.com> <55DDDA73.8020507@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <55DDDA73.8020507@redhat.com> Subject: Re: [Qemu-devel] [PATCH v5 2/9] make: ensure all members of libqemuutil.a are linked Reply-To: "Daniel P. Berrange" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: Paolo Bonzini , qemu-devel@nongnu.org, Gerd Hoffmann On Wed, Aug 26, 2015 at 09:25:39AM -0600, Eric Blake wrote: > On 08/26/2015 09:05 AM, Daniel P. Berrange wrote: > > The libqemuutil.a archive may contain QOM objects which are > > only indirectly referenced via __attribute__((constructor)) > > annotations. Despite the constructor annotation the linker > > will think these objects are unused by the executable and > > so drop them when linking, to the system emulator. As a > > result the objects in question will be missing from QOM. > > > > Using the -Wl,--whole-archive flag instructs the linker > > to pull in everything in libqemuutil.a regardless of > > whether it thinks it is used or not. > > > > Signed-off-by: Daniel P. Berrange > > --- > > Makefile.target | 7 ++++++- > > 1 file changed, 6 insertions(+), 1 deletion(-) > > > > diff --git a/Makefile.target b/Makefile.target > > index 3e7aafd..5b08f0f 100644 > > --- a/Makefile.target > > +++ b/Makefile.target > > @@ -180,8 +180,13 @@ all-obj-$(CONFIG_SOFTMMU) += $(block-obj-y) > > $(QEMU_PROG_BUILD): config-devices.mak > > > > # build either PROG or PROGW > > +# We must use --whole-archive with libqemuutil.a otherwise the > > +# linker will drop any objects from the archive which are only > > +# indirectly referenced via __attribute__(constructor) annotations > > $(QEMU_PROG_BUILD): $(all-obj-y) ../libqemuutil.a ../libqemustub.a > > - $(call LINK, $(filter-out %.mak, $^)) > > + $(call LINK, $(filter-out %.mak, $(sort $(all-obj-y)))) \ > > Why the added $(sort)? Should that be a separate patch? $(all-obj-y) has some .o's listed multiple times. $^ removes duplicates, avoiding this problem, but if we use $(all-obj-y) we must now remove duplicates ourselves. $(sort) removes duplicates and AFAICT, there's no built-in make function that can remove duplicates without sorting. > > > + -Wl,--whole-archive ../libqemuutil.a -Wl,--no-whole-archive \ > > + ../libqemustub.a > > Otherwise makes sense to me. > Reviewed-by: Eric Blake Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|