Ralf Wildenhues kindly provided me with 4 out of the 5 critical pieces of information that I needed:
> --- configure.ac --- > AM_INIT_AUTOMAKE([1.9 subdir-objects]) 1. subdir-objects to build x/y/z.o from x/y/z.c instead of just z.o see the last paragraph describing 'maude_SOURCES' in the manual at: http://sources.redhat.com/automake/automake.html#Program-and-Library-Variables > --- Makefile.am --- > lib_LIBRARIES = > bin_PROGRAMS = > include lib1/Makefile.am > include lib2/Makefile.am > include app1/Makefile.am > include app2/Makefile.am 2. initialise variables in Makefile.am, and then add actual values to them in the */Makefile.am 3. include */Makefile.am to create one big Makefile, instead of using AC_CONFIG_FILES([Makefile lib1/Makefile ...]) in autoconf.ac which generates completely separate Makefiles > --- app2/Makefile.am --- > bin_PROGRAMS += app2/app2 > app2_app2_SOURCES = app2/main.cpp > app2_app2_LDADD = lib2/lib2.a > > --- lib2/Makefile.am --- > lib_LIBRARIES += lib2/lib2.a > lib2_lib2_a_SOURCES = lib2/file-in-lib2.cpp 4. provide the correct magic {directory, /, _} combinations to match the correct targets in different directories. And the last critical point? 5. I had tried every combination I could think of to build lib2/lib2.a and then link it into app2 but I always got an undefined reference. But this was down to a major 'thinko' on my part so I wasn't also linking against lib1/lib1.a. I've been going in circles trying to solve the wrong problem :-( Talk about not being able to see the wood for the trees! Thank you for your help. I do believe I have the foundation I need. Cheers Duncan
