Hello Peter, * Peter Johansson wrote on Sat, Feb 12, 2011 at 09:56:41PM CET: > I got bitten by how VPATH builds work and wondered if there is a > good way to avoid getting bitten again.
Not an easy question. > I have an Automake snippet (see below) that creates a file, > `.revision', with current revision number and from this is a C > header file `revision.h' created. Then to test that things work as > I'd like I have target similar to distcheck that essentially does > > svn export $(srcdir) _exported > cd _exported > ./bootstrap > mkdir _build > cd _build > ../configure > make > make check > > When doing that here I get the following error: > > revision=$(cat ../.revision) \ > && sed "s|@SVN_REVISION@|$revision|g" < ../svn_revision.h.in \ > > svn_revision.h-t && mv svn_revision.h-t svn_revision.h > cat: ../.revision: No such file or directory > > and when I look into why there is no `../.revision' and I try > > make `../.revision' I get > make: `../../.revision' is up to date. > > That is make finds the file in my original working copy and not in > my current structure. Is there a good way to avoid this to happen? I'd try to ensure the VPATH structure of your "distcheck" is different from the one above that. I.e,. either use two levels of _build/_build or have the upper build directory be a sibling, rather than a subdir, of the source tree. > --- Makefile.am --- > > EXTRA_DIST = .revision svn_revision.h.in I'd use $(srcdir)/.revision here. That helps non-GNU makes understand that it's the same thing that there is a rule for below. But please see 'info Autoconf "VPATH and Make"' for all the problems VPATH can make (sorry for the pun). > BUILT_SOURCES = $(srcdir)/.revision $(builddir)/svn_revision.h > > if HAVE_SVN_WC > YAT_SVN_REVISION_FORCE: > $(srcdir)/.revision: YAT_SVN_REVISION_FORCE > @$(SVNVERSION) $(srcdir) > $@-t \ > && $(MOVE_IF_CHANGE) $@-t $@ I would prepend all lines of a rule with a TAB, not just those not following a backslash-escaped newline. I'm actually not totally sure whether that was for portability to non-Posix make or so automake would parse things reliably. > else > ## this is needed in 'svn export' build > $(srcdir)/.revision: > echo "" > $@ I don't see why you should need this rule here. The .revision file is distributed, so it should already exist. At most I'd add a stub target $(srcdir)/.revision: here. Maybe I'm missing something? > endif > $(builddir)/svn_revision.h: $(srcdir)/svn_revision.h.in $(srcdir)/.revision > revision=$$(cat $(srcdir)/.revision) \ > && sed "s|@SVN_REVISION@|$$revision|g" < $(srcdir)/svn_revision.h.in \ > > $@-t && mv $@-t $@ Hope that helps. Cheers, Ralf
