In configure.ac:
LIBCXX_INIT
In Makefile.am:
@LIBCXX_AM@ # Followed by macro calls: $(call OPTIONS_GEN,cliopts.H,cliopts.xml) # ...
After the single line containing @LIBCXX_AM@,
invoke the OPTIONS_GEN macro to create the
make rules.
The “LIBCXX_INIT”
autoconf
macro sets LIBCXX_AM to the include statement
that pulls in libcxx.mk.
libcxx.mk does a rudimentary check
if AUTOMAKE is set. If so, it automatically
generates a make distclean rule to remove
all targets generated by the macros. The
LIBCXX_CLEANFILES variable
accumulates the list of targets produced by all macro invocations,
and may be utilized by non-automake makefiles for similar purposes.
Additionally, all .xml dependencies get added
to EXTRA_DIST. Any assignments to
EXTRA_DIST in Makefile.am
must occur before inclusion of libcxx.mk.
It is permitted to use += to add to
EXTRA_DIST after the inclusion of
libcxx.mk.