From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50039) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1co6eX-00032Z-Ij for qemu-devel@nongnu.org; Wed, 15 Mar 2017 06:59:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1co6eW-0005WU-Ie for qemu-devel@nongnu.org; Wed, 15 Mar 2017 06:59:37 -0400 Date: Wed, 15 Mar 2017 10:59:24 +0000 From: "Daniel P. Berrange" Message-ID: <20170315105924.GH7770@redhat.com> Reply-To: "Daniel P. Berrange" References: <20170310031521.630-1-eblake@redhat.com> <033881fe-b3d3-2c3a-48fc-c08691f2c9cb@redhat.com> <19efa7dc-fa97-410f-df4d-3962453dcd8e@redhat.com> <20170315101835.GF8147@stefanha-x1.localdomain> <20170315102644.GF7770@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20170315102644.GF7770@redhat.com> Subject: Re: [Qemu-devel] [PATCH for-2.9] mirror: Fix backwards mirror_yield parameters List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: kwolf@redhat.com, qemu-block@nongnu.org, Jeff Cody , qemu-devel@nongnu.org, Max Reitz On Wed, Mar 15, 2017 at 10:26:44AM +0000, Daniel P. Berrange wrote: > On Wed, Mar 15, 2017 at 06:18:35PM +0800, Stefan Hajnoczi wrote: > > On Fri, Mar 10, 2017 at 02:49:22PM -0600, Eric Blake wrote: > > > And here's where I'm stuck: the makefiles are broken. Touching > > > scripts/tracetool/format/h.py does NOT cause tracetool to be re-run by a > > > mere 'make'; I've had to resort to 'make -B block/trace.h-timestamp' to > > > get things to rebuild. And this is in spite of the fact that h.py > > > _should_ be getting listed in $(tracetool-y) by trace/Makefile.objs, and > > > $(tracetool-y) is listed as a dependency of %/trace.h-timestamp in the > > > top-level Makefile. I would appreciate anyone with advice or an idea on > > > how to patch Makefile to get the dependency working without me having to > > > manually kick it. > > > > Also CCing Daniel Berrange. He recently touched the tracing Makefiles > > and may have ideas. > > I've been looking at this and I'm damned if I understand what's broken. > All the required dependancies look to be expressed in the Makefile > > %/trace.h: %/trace.h-timestamp > %/trace.h-timestamp: $(SRC_PATH)/%/trace-events $(tracetool-y) > > and $(tracetool-y) expands to the list of source files > > tracetool-y = $(SRC_PATH)/scripts/tracetool.py > tracetool-y += $(shell find $(SRC_PATH)/scripts/tracetool -name "*.py") > > > If I do 'touch hw/net/trace-events', then hw/net/trace.h gets rebuilt, > but if do 'touch scripts/tracetool.py' it doesn't get built. So somehow > make seems to be dropping the $(tracetool-y) deps despite being listed > against the %/trace-h-timestamp file, and despite earlier deps on > trace-events being honoured Oh this is a fun one. While the $(tracetool-y) variable *is* defined at the time the build rules execute, it is *not* defined at the time make evaluates dependancies, so it expanded to be empty ! I copied you on the easy fix Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://entangle-photo.org -o- http://search.cpan.org/~danberr/ :|