Re: How to find out which modules have brought in a particular module

[Pádraig Brady]

On 19/10/15 21:21, Gavin Smith wrote:
> I'm interested in reducing the number of checks done in a configure
> script: one way could be to make more use of conditional dependencies
> between modules. gnulib-tool --add-import lists the modules which were
> used and which were brought in as dependencies. However, there are
> some things I'd like to do that I couldn't find options for. One is to
> see which modules brought in a module. The way I was doing this was by
> going into the "gnulib/modules" directory in the Gnulib checkout and
> grepping for the name of the module. It would be nice to be able to
> get this information automatically, and in a way that takes into
> account indirect dependencies. Maybe there should be an option for
> gnulib-tool that can list the modules that have been brought in, and
> for each of them, list the modules that have been explicitly asked for
> that depend on the module, directly or indirectly, and also list the
> modules that depend on the module conditionally.
> 
> For example I wondered why the checks for the unistd module were being
> run. I found that getopt-posix had a dependency on it. I edited the
> module file to make this a conditional dependency, reran gnulib-tool
> --add-import, ran "make configure" to remake the configure script: but
> when I ran "configure" again, the tests were still run. I expected
> that there was another module also depending on unistd, but it wasn't
> immediately obvious which one, because several modules that could have
> been imported depended on unistd. That's as far as I got investigating
> the matter. Is there an easier way to investigate this kind of thing,
> that I've been missing? Or would gnulib-tool benefit from the extra
> functionality I've suggested?

There was some work on displaying a graph previously.
http://lists.gnu.org/archive/html/bug-gnulib/2011-03/msg00276.html
Something like this is worth adding I think.

cheers,
Pádraig