broken automatic deps for prefixed object files?

[Markus Werle]

Hi!

In order to resolve name clashes for object files, some of the object files
in my Makefile.am obtain a prefix by using the CPPFLAGS trick

some_exectuable_CPPFLAGS = $(AM_CPPFLAGS)


This works fine so far, but unfortunately there seems to be something
wrong with the .deps files (or an error elsewhere):

They only mention the original filename.o not the
some_executable-filename.o, so the package ain't rebuilt when files change.

Is this a bug or do I have to provide further information to  the Makefile.am?

OTOH
Is there a way to resolve the name clashes without the CPPFLAGS trick,
e.g. let automake put object files in per-executable directories?
Using AM_INIT_AUTOMAKE([subdir-objects]) fails for source files
from external directories: then the dependencies are searched in the external 
source
tree, not in the build tree. Any idea what went wrong?

Thanks,


Markus