I am working on the C project e-antic  which also contains a (header
only) C++ interface. Most of the tests are written in C but the ones
testing the C++ interface are of course in C++. I am facing difficulties
to make it work properly.
The current automake setup is as follows
- /Makefile.am: for the C code compilation and the C test programs
- /e-antic/test/Makefile.am: for the C++ test programs
First of all, I would be happier with only one Makefile.am but I am not
sure it is easily feasible. Secondly, when running "make check" in VPATH
builds the C++ test programs fail to find the header files (it works
fine when the source tree and the build tree is the same). The relevant
instructions in /e-antic/test/Makefile.am are
AM_CPPFLAGS = -I../..
LDADD = ../../libeantic.la
and I believe that they are wrong. Though I was not able to fix them.