11.3 Using libtoolize

Having made the necessary editions in `configure.in' and `Makefile.am', all that remains is to add the Libtool infrastructure to your project.

First of all you must ensure that the correct definitions for the new macros you use in `configure.in' are added to `aclocal.m4', See section C. Generated File Dependencies. At the moment, the safest way to do this is to copy `libtool.m4' from the installed libtool to `acinclude.m4' in the toplevel source directory of your package. This is to ensure that when your package ships, there will be no mismatch errors between the M4 macros you provided in the version of libtool you built the distribution with, versus the version of the Libtool installation in another developer's environment. In a future release, libtool will check that the macros in aclocal.m4 are from the same Libtool distribution as the generated libtool script.

$ cp /usr/share/libtool/libtool.m4 ./acinclude.m4 $ aclocal

By naming the file `acinclude.m4' you ensure that aclocal can see it and will use macros from it, and that automake will add it to the distribution when you create the tarball.

Next, you should run libtoolize, which adds some files to your distribution that are required by the macros from `libtool.m4'. In particular, you will get `ltconfig'(20) and `ltmain.sh' which are used to create a custom libtool script on the installer's machine.

If you do not yet have them, libtoolize will also add `config.guess' and `config.sub' to your distribution. Sometimes you don't need to run libtoolize manually, since automake will run it for you when it sees the changes you have made to `configure.in', as follows:

$ automake --add-missing automake: configure.in: installing ./install-sh automake: configure.in: installing ./mkinstalldirs automake: configure.in: installing ./missing configure.in: 8: required file ./ltconfig not found

The error message in the last line is an aberration. If it were consistent with the other lines, it would say:

automake: configure.in: installing ./ltconfig automake: configure.in: installing ./ltmain.sh automake: configure.in: installing ./config.guess automake: configure.in: installing ./config.sub

But the effect is the same, and the files are correctly added to the distribution despite the misleading message.

Before you release a distribution of your project, it is wise to get the latest versions of `config.guess' and `config.sub' from the GNU site(21), since they may be newer than the versions automatically added by libtoolize and automake. Note that automake --add-missing will give you its own version of these two files if `AC_PROG_LIBTOOL' is not used in the project `configure.in', but will give you the versions shipped with libtool if that macro is present!