6.2 Building a library

Building a library is much like building a program. In this case, the name of the primary is ‘LIBRARIES’. Libraries can be installed in libdir or pkglibdir.

Each ‘_LIBRARIES’ variable is a list of the base names of libraries to be built. For instance to create a library named libcpio.a, but not install it, you would write:

noinst_LIBRARIES = cpio

The sources that go into a library are determined exactly as they are for programs, via the ‘_SOURCES’ variables. Note that programs and libraries share a namespace, so one cannot have a program (lob) and a library (liblob.a) with the same name in one directory.

Extra objects can be added to a library using the ‘library_LIBADD’ variable. This should be used for objects determined by configure. Again from cpio:

cpio_LIBADD = @LIBOBJS@ @ALLOCA@

Note that Automake explicitly recognizes the use of @LIBOBJS@ and @ALLOCA@ in the above example, and uses this information, plus the list of LIBOBJS files derived from configure.in to automatically include the appropriate source files in the distribution (see What Goes in a Distribution). These source files are also automatically handled in the dependency-tracking scheme, see See Automatic dependency tracking.