Re: [libvirt] [PATCH 1/4] build: avoid $(srcdir) in *_SOURCES

Trying to enable automake's subdir-objects option resulted in the creation of literal directories such as src/$(srcdir)/remote/. I traced this to the fact that we had used a literal $(srcdir) in a location that later fed an automake *_SOURCES variable. This has also been reported as an automake bug: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=13928 but it's better to fix our code than to wait for an automake fix. Some things to remember that affect VPATH builds, and where an in-tree build is blissfully unaware of the issues: if a VPATH build fails to find a file that was used as a prereq of any other target, then the rule for that file will expand $@ to prefer the current build dir (bad because a VPATH build on a fresh checkout will then stick $@ in the current directory instead of the desired srcdir); conversely, if a VPATH build finds the file in srcdir but decides it needs to be rebuilt, then the rule for that file will expand $@ to include the directory where it was found out-of-date (bad for an explicit listing of $(srcdir)/$@ because an incremental VPATH build will then expand srcdir twice). As we want these files to go into srcdir unconditionally, we have to massage or avoid $@ for any recipe that involves one of these files. Therefore, this patch removes all uses of $(srcdir) from any generated file name that later feeds a *_SOURCES variable, and then rewrites all the recipes to generate those files to hard-code their creation into srcdir without the use of $@. * src/Makefile.am (REMOTE_DRIVER_GENERATED): Drop $(srcdir); VPATH builds know how to find the files, and automake subdir-objects fails with it in place. (LXC_MONITOR_PROTOCOL_GENERATED, (LXC_MONITOR_GENERATED) (ACCESS_DRIVER_GENERATED, LOCK_PROTOCOL_GENERATED): Likewise. (*_client_bodies.h): Hard-code rules to write into srcdir, as VPATH tries to build $@ locally if missing. (util/virkeymaps.h): Likewise. (lxc/lxc_monitor_dispatch.h): Likewise. (access/viraccessapi*): Likewise. (locking/lock_daemon_dispatch_stubs.h): Likewise. * daemon/Makeflie.am (DAEMON_GENERATED, remote_dispatch.h): Likewise. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; fixup DAEMON_GENERATED --- daemon/Makefile.am | 23 ++++++----- src/Makefile.am | 109 ++++++++++++++++++++++++++++++----------------------- 2 files changed, 74 insertions(+), 58 deletions(-) diff --git a/daemon/Makefile.am b/daemon/Makefile.am index 90689f8..e0b8744 100644 --- a/daemon/Makefile.am +++ b/daemon/Makefile.am @@ -29,10 +29,10 @@ INCLUDES = \ CLEANFILES = -DAEMON_GENERATED = \ - $(srcdir)/remote_dispatch.h \ - $(srcdir)/lxc_dispatch.h \ - $(srcdir)/qemu_dispatch.h \ +DAEMON_GENERATED = \ + remote_dispatch.h \ + lxc_dispatch.h \ + qemu_dispatch.h \ $(NULL) DAEMON_SOURCES = \ @@ -75,20 +75,23 @@ REMOTE_PROTOCOL = $(top_srcdir)/src/remote/remote_protocol.x LXC_PROTOCOL = $(top_srcdir)/src/remote/lxc_protocol.x QEMU_PROTOCOL = $(top_srcdir)/src/remote/qemu_protocol.x -$(srcdir)/remote_dispatch.h: $(srcdir)/../src/rpc/gendispatch.pl \ +remote_dispatch.h: $(srcdir)/../src/rpc/gendispatch.pl \ $(REMOTE_PROTOCOL) $(AM_V_GEN)$(PERL) -w $(srcdir)/../src/rpc/gendispatch.pl \ - --mode=server remote REMOTE $(REMOTE_PROTOCOL) > $@ + --mode=server remote REMOTE $(REMOTE_PROTOCOL) \ + > $(srcdir)/remote_dispatch.h

$(srcdir)/$@