Re: GNU Automake 1.14 released

[Bert Wesarg]

Hi,

On Fri, Jun 21, 2013 at 2:01 PM, Stefano Lattarini
<address@hidden> wrote:
> We are pleased to announce the GNU Automake 1.14 minor release.
>
>
>   - The next major Automake version (2.0) will unconditionally activate
>     the 'subdir-objects' option.  In order to smooth out the transition,
>     we now give a warning (in the category 'unsupported') whenever a
>     source file is present in a subdirectory but the 'subdir-object' is
>     not enabled.  For example, the following usage will trigger such a
>     warning:
>
>         bin_PROGRAMS = sub/foo
>         sub_foo_SOURCES = sub/main.c sub/bar.c
>

we don't understand how this warning should 'smooth' the transition to
post-1.14 in our project.

Here is our situation:

We have a source file which needs to be compiled twice. But with
different compilers. Thus we can't use per-target flags and we use two
separate Makefile.am files for this. Because the compilation rules are
nearly identical, we use a Makefile.common.inc.am file which will be
included by both Makefile.am's. Here is the directory layout (the
complete reduced testcase is attached):

src/foo.c
src/Makefile.am
src/Makefile.common.inc.am
src/second/Makefile.am

The src/Makefile.am looks like:

---- 8< src/Makefile.am 8< ---
SUBDIRS = second

MY_SRCDIR=.
include Makefile.common.inc.am

bin_PROGRAMS=foo
foo_SOURCES=$(FOO_COMMONSOURCES)
---- >8 src/Makefile.am >8 ---

---- 8< src/second/Makefile.am 8< ---
CC=$(top_srcdir)/bin/wrapper

MY_SRCDIR=..
include ../Makefile.common.inc.am

bin_PROGRAMS=foo-wrapped
foo_wrapped_SOURCES=$(FOO_COMMONSOURCES)
---- >8 src/second/Makefile.am >8 ---

---- 8< src/Makefile.common.inc.am 8< ---
FOO_COMMONSOURCES = $(MY_SRCDIR)/foo.c
---- >8 src/Makefile.common.inc.am >8 ---

This works with automake 1.13.4 as expected. Now, with automake 1.14
we get the newly introduced warning mentioned above in the release
statements. Now enabling subdir-objects is not yet an option for us,
because we use variables in the _SOURCES list and bug 13928 [1] hits
us.

So what would be the best transition in this situation? We don't want
to remove the Makefile.common.inc.am to avoid the resulting redundancy
in the two Makefile.am files. We also can't use the newly introduced
%reldir%, because it also throws the warning, and also want to
maintain compatibly with pre-1.14 automake.

Any guidance is more than welcomed.

Kind Regards,
Matthias Jurenz & Bert Wesarg

[1] http://debbugs.gnu.org/cgi/bugreport.cgi?bug=13928

foo-subdir-objects-warnings.tar.gz
Description: GNU Zip compressed data