Re: Automake 1.15 + subdir-objects using $(top_srcdir) in *_SOURCES

[Bert Wesarg]

Hi,

On Tue, Aug 18, 2015 at 10:08 AM, Tom Ghyselinck
<address@hidden> wrote:
> Hi all,
>
> I just upgraded to automake-1.15.
>
> I got a warning about future incompatibilities:
>     src/Makefile.am:205: warning: source file 
> 'StackControllers/AbstractController.cpp' is in a subdirectory,
>     src/Makefile.am:205: 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.
>
> We use "<subdir>/<source_file>.cpp" in some "*_SOURCES" entries in our
> "Makefile.am" files.
>
> Since I don't like warnings, I followed the suggestion and added the "s
> ubdir-objects" option in our configure.ac.
>
> Now, in one of our Makefile.am we are using
>     gtest_SOURCES = $(top_srcdir)/src/globaloptions.cpp ...
>
> We build our project in /tmp/build.
> When trying to execute "make clean" for our project, we get the error:
>     Making clean in testing
>     make[2]: Entering directory '/tmp/build/src/testing'
>     Makefile:1193: /path/to/source/src/.deps/gtest-globaloptions.Po: No such 
> file or directory
>     make[2]: *** No rule to make target 
> '/path/to/source/src/.deps/gtest-globaloptions.Po'.  Stop.
>     make[2]: Leaving directory '/tmp/build/src/testing'
>     Makefile:1513: recipe for target 'clean-recursive' failed
>
> Is this a known issue?
> Or is it incorrect to use "$(top_srcdir)" in the "*_SOURCES" directive
> when using the "subdirs-objects" option?
>
> We would like to keep using the "$(top_srcdir)" since the subdirs where
> the Makefile.am using this resides may move around in the project
> directory tree.
>
> Can anyone explain what is going wrong or how we should update this to
> keep this working?
>
> Thank you in advance!

I would say you hit two bugs already fixed after the release of 1.15.

http://debbugs.gnu.org/13928

Bert

>
> With best regards,
> Tom.
>