autocon and sub-packages

[Sébastien Hinderer]

Dear all,

I am one of the maintainers of Coccinelle[1], a tool written in the
Objective Caml[2] language.

The tool is distributed with the libraries it depends on (they are
provided as bundles).

For each dependency, coccinelle's configure script checks whether the
library is already installed. If not, the system is prepared to use the
bundled version.

Then when one runs make, all the bundles that are required are
uncompressed, configure is called for them and they are built, afterwards
the tool itself is built.

This approach does not seem very satisfactory to me. For a start, I find
it cumbersome to provide the dependencies as bundles but I'm not the
person making the decisions. However, any opinion or pointer about
software bundling their dependencies, pros and cons and the techniques
used to do so would be warmly appreciated.

Then, assuming we continue to bundle the dependencies, it seems to me
that it would be more coherent to have the configure script of each
required bundle run by the tool's main configure script. I am aware of
the AC_CONFIG_SUBDIRS macro, but this seems a bit limited to me. For
instance it means that the sub-package's configure may find a different
compiler to use than the one found by the main conigure, which is not
good.

One other issue is that we bundle the dependencies as .tar.gz archives
and we would like to be able to extract the archives only for those
dependencies that will really be needed (because they are not already
installed on the system). Can this be achieved somehow with autoconf?

Thanks a lot for any feedback!

Sébastien.