8.3.2 Building Libtool Libraries

Automake uses libtool to build libraries declared with the LTLIBRARIES primary. Each _LTLIBRARIES variable is a list of libtool libraries to build. For instance, to create a libtool library named ‘libgettext.la’, and install it in libdir, write:

lib_LTLIBRARIES = libgettext.la
libgettext_la_SOURCES = gettext.c gettext.h …

Automake predefines the variable pkglibdir, so you can use pkglib_LTLIBRARIES to install libraries in ‘$(libdir)/@PACKAGE@/’.

If ‘gettext.h’ is a public header file that needs to be installed in order for people to use the library, it should be declared using a _HEADERS variable, not in libgettext_la_SOURCES. Headers listed in the latter should be internal headers that are not part of the public interface.

lib_LTLIBRARIES = libgettext.la
libgettext_la_SOURCES = gettext.c …
include_HEADERS = gettext.h …

A package can build and install such a library along with other programs that use it. This dependency should be specified using LDADD. The following example builds a program named ‘hello’ that is linked with ‘libgettext.la’.

lib_LTLIBRARIES = libgettext.la
libgettext_la_SOURCES = gettext.c …

bin_PROGRAMS = hello
hello_SOURCES = hello.c …
hello_LDADD = libgettext.la

Whether ‘hello’ is statically or dynamically linked with ‘libgettext.la’ is not yet known: this will depend on the configuration of libtool and the capabilities of the host.