Hi,
I'm having trouble understanding what the subdir-objects option does. The
project I'm building [1] prints a warning when building without
subdir-objects:
libgd/Makefile.am:29: warning: source file 'libgd/gd-types-catalog.c' is in
a subdirectory,
libgd/Makefile.am:29: but option 'subdir-objects' is disabled
automake: warning: possible forward-incompatibility.
automake: At least a source file is in a subdirectory, but the
'subdir-objects'
automake: automake option hasn't been enabled. For now, the corresponding
output
automake: object file(s) will be placed in the top-level directory.
However,
automake: this behaviour will change in future Automake versions: they will
automake: unconditionally cause object files to be placed in the same
subdirectory
automake: of the corresponding sources.
automake: You are advised to start using 'subdir-objects' option throughout
your
automake: project, to avoid future incompatibilities.
My understanding (based on [2]) is that subdir-objects changes where the
generated object files are placed, so I tried the following:
git checkout with-subdir-objects
git clean -dfx
./autogen.sh
make
find . > /tmp/with-subdir-objects-tree
git checkout without-subdir-objects
git clean -dfx
./autogen.sh
make
find . > /tmp/without-subdir-objects-tree
diff /tmp/with{,out}-subdir-objects-tree
The diff found 0 different lines, so I guess I'm missing something. What
exactly does subdir-objects do?
Thanks,
Kerrick
[1] The project is gnome-boxes: http://git.gnome.org/gnome-boxes
[2]
http://www.gnu.org/software/automake/manual/html_node/List-of-Automake-options.html#index-subdir_00http://git.gnome.org/gnome-boxes2dobjects<http://www.gnu.org/software/automake/manual/html_node/List-of-Automake-options.html#index-subdir_002dobjects>
