Hi Justin,
On 2/2/2010 6:39 PM, Justin Seyster wrote:
I'm pretty sure that making the framework a convenience library is my
ideal solution: the plug-in author will be able to distribute a single
shared object without any non-standard dependencies. However, I read
that Automake does not allow installing a convenience library. I
verified that a regular static library (not specified with
noinst_LTLIBRARIES) definitely does not work: the resulting .a file is
not position independent and won't link into a plug-in. I don't want
to use noinst_LTLIBRARIES, though, for the simple reason that I want
to be able to install the library!
A convenience library is so named because it provides the convenient
effect of encapsulating a set of code that multiple products can link to
within a package. That's it's only purpose - to bundle up code that can
then be linked into multiple products within your package. Hence, it's
not intended to be consumed outside of your package.
You're correct in understanding that a non-libtool (*_LIBRARY) product
is a non-PIC static library, and you are also correct in understanding
that they can't be linked into a shared library for this reason.
You can build installed LTLIBRARIES as shared libraries, static
libraries, or both, and you can configure the default in your
configure.ac file, but unfortunately, I haven't found a way to make this
default apply only to a subset of the installed LTLIBRARIES built within
a package. It appears to be all or nothing. Furthermore, it's just a
default. The user can always override your defaults with command line
options to configure. Personally, I think it would be a nice enhancement
to Automake to allow you to specify that you want specifically to build
an installed static (only) LTLIBRARY that can then be linked into a
shared library in another package. The Libtool manual states that
there's no good reason for doing this, but you and I have both
encountered situations when we want to do just this.
For the reasons outlined above, automake doesn't allow you to build a
convenience library and install it. The only way to build a convenience
(PIC-based static only) library is to use the "noinst" prefix. But
libtool can be used to manually install a convenience library, so you
could use libtool to do this in an install-exec-local rule in the
Makefile.am file that builds (for instance) libhello.a (untested):
install-exec-local:
libtool --mode=install ./install-sh -c libhello.a
$(DESTDIR)$(lib)/libhello.a
This example came from the libtool manual (modified slightly for
Automake context).
Regards,
John
