Suppose I want all my source files to be placed under $(top_srcdir)/include/name/space/name, and therefore want something like the results of AM_CPPFLAGS = -I$(top_srcdir)/include in all my gcc invocations. One way I've found, which seems to work is to create a $(top_srcdir)/Makefile.project with the AM_CPPFLAGS line, then include $(top_srcdir)/Makefile.project in all the Makefile.am instances. The only drawback to this is that I need to be sure the line is in all the Makefile.ams. It's not that big of a deal if I'm maintaining by hand, but if I use a tool that manages my Autotools configuration, it may not cooperate. I've read that it's not a good idea to change the CPPFLAGS variable itself, as might be done with autoconf AC_SUBST (VARIABLE, [VALUE]). Is there a way to accomplish this without messing with each Makefile.am? -- Regards, Steven