From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:48764) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TPGpp-0004mq-3i for qemu-devel@nongnu.org; Fri, 19 Oct 2012 13:58:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TPGpo-0003iw-19 for qemu-devel@nongnu.org; Fri, 19 Oct 2012 13:58:13 -0400 Received: from mail-ie0-f173.google.com ([209.85.223.173]:46055) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TPGpn-0003ih-Sh for qemu-devel@nongnu.org; Fri, 19 Oct 2012 13:58:11 -0400 Received: by mail-ie0-f173.google.com with SMTP id 17so1011315iea.4 for ; Fri, 19 Oct 2012 10:58:11 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1350654863-26048-1-git-send-email-peter.maydell@linaro.org> References: <1350654863-26048-1-git-send-email-peter.maydell@linaro.org> From: Blue Swirl Date: Fri, 19 Oct 2012 17:57:51 +0000 Message-ID: Content-Type: text/plain; charset=UTF-8 Subject: Re: [Qemu-devel] [PATCH] Makefile: Forbid out-of-tree build from a source tree that has been built in List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: qemu-devel@nongnu.org, patches@linaro.org On Fri, Oct 19, 2012 at 1:54 PM, Peter Maydell wrote: > If we try to do an out-of-tree build but the source tree we're building from > has been used in the past for an in-tree build then things will go > confusingly wrong. Specifically, some parts of the build process will pull > in generated files from the old in-tree build (because SRC_PATH is on > the vpath). Diagnose this situation so we can produce a useful error > message and tell the user how to fix it (run distclean in the source tree). > > Signed-off-by: Peter Maydell OK, but maybe we should deprecate in-tree build and warn if it is detected. > --- > I got bitten by this again the other day so I figured it was worth > adding a molly-guard. The check is not perfect (it won't notice if > you did a distclean but didn't delete the *-softmmu &c directories, > for instance) but it should catch most cases of this user error. > > Makefile | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/Makefile b/Makefile > index a9c22bf..5094a08 100644 > --- a/Makefile > +++ b/Makefile > @@ -8,6 +8,17 @@ ifneq ($(wildcard config-host.mak),) > # Put the all: rule here so that config-host.mak can contain dependencies. > all: > include config-host.mak > + > +# Check that we're not trying to do an out-of-tree build from > +# a tree that's been used for an in-tree build. > +ifneq ($(realpath $(SRC_PATH)),$(realpath .)) > +ifneq ($(wildcard $(SRC_PATH)/config-host.mak),) > +$(error This is an out of tree build but your source tree ($(SRC_PATH)) \ > +seems to have been used for an in-tree build. You can fix this by running \ > +"make distclean && rm -rf *-linux-user *-softmmu" in your source tree) > +endif > +endif > + > include $(SRC_PATH)/rules.mak > config-host.mak: $(SRC_PATH)/configure > @echo $@ is out-of-date, running configure > -- > 1.7.9.5 > >