Re: substitution vs expansion in Makefile.am

[John Calcote]

NOTE: I routinely build in non-source directories because I can keep
separate sets of configure options.

Bob, server/Makefile's VPATH only contains the expansion of
@top_srcdir@/server, which in this case is ../../server. This means
that make won't be able to find any sources listed that exist in
directories other than ../../server. So I think I HAVE to use
$(top_srcdir)/common/mySleep.c, don't I, as it's in a different source
directory? Note that I'm not using a path on registrar.c - it's found
in the server directory. Also note that this is a unit test build, so
I'm grabbing files from the common directory to add to my unit test.
Perhaps I should be using the common convenience library rather than
the common source files directly, but sometimes I need different
compiler options for the test objects.

Ralf, I should think that using @top_srcdir@ in a SOURCES list would
be better than $(top_srcdir) because it will be replaced by hard path
info in the final Makefile. On the other hand, since automake converts
Makefile.am to Makefile.in before autoconf gets around to replacing
the variable with path info...

>  >   registrarTest_SOURCES = registrar.c\
>  >      @top_srcdir@/common/mySleep.c

>  You should always use the Makefile form in Makefiles.  You should
>  always use relative paths in the source tree (from the Makefile
>  location) to refer to source files from your package (i.e. don't use
>  @top_srcdir@).  If your package is built in some other directory,
>  VPATH will be used to tell make where to look for the source files.