Header files that must be installed are specified by the
HEADERS family of variables. Headers can be installed in
includedir, oldincludedir, pkgincludedir or any
other directory you may have defined (see The Uniform Naming Scheme). For instance,
include_HEADERS = foo.h bar/bar.h
will install the two files as $(includedir)/foo.h and $(includedir)/bar.h.
The nobase_ prefix is also supported:
nobase_include_HEADERS = foo.h bar/bar.h
will install the two files as $(includedir)/foo.h and $(includedir)/bar/bar.h (see An Alternative Approach to Subdirectories).
Usually, only header files that accompany installed libraries need to
be installed. Headers used by programs or convenience libraries are
not installed. The noinst_HEADERS variable can be used for
such headers. However, when the header belongs to a single
convenience library or program, we recommend listing it in the
program’s or library’s _SOURCES variable (see Defining program sources) instead of in noinst_HEADERS. This is clearer for
the Makefile.am reader. noinst_HEADERS would be the
right variable to use in a directory containing only headers and no
associated library or program.
All header files must be listed somewhere; in a _SOURCES
variable or in a _HEADERS variable. Missing ones will not
appear in the distribution.
For header files that are built and must not be distributed, use the
nodist_ prefix as in nodist_include_HEADERS or
nodist_prog_SOURCES. If these generated headers are needed
during the build, you must also ensure they exist before they are
used (see Built Sources).