Re: Autoconfisticating a multi-directory, non-recursive, GNU-make specific project

[Duncan Gibson]

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