19. Include

Automake supports an include directive that can be used to include other ‘Makefile’ fragments when automake is run. Note that these fragments are read and interpreted by automake, not by make. As with conditionals, make has no idea that include is in use.

There are two forms of include:

include $(srcdir)/file

Include a fragment that is found relative to the current source directory.

include $(top_srcdir)/file

Include a fragment that is found relative to the top source directory.

Note that if a fragment is included inside a conditional, then the condition applies to the entire contents of that fragment.

Makefile fragments included this way are always distributed because they are needed to rebuild ‘Makefile.in’.