Re: Passing configure time settings to sub-packages.

[Ralf Wildenhues]

Hello Craig,

* Craig Sanders wrote on Mon, Oct 01, 2007 at 01:06:56PM CEST:
> 
> Directory ~/simple/subpackage also contains a configure.ac file. To
> try and help explain my original question, say ~/simple/configure.ac
> checked for the presence of the Boost threading library on the host
> system. If it found it, it could store the result in a variable.
> However, say ~/simple/subpackage/configure.ac also needed to check for
> the Boost threading library. Rather than searching for the library
> again, is there any way that the result can be passed across to the
> configure.ac (actually configure) script in the sub-package from the
> configure script in the package?

One possibility is to just put the test for Boost in both configure
scripts, and store the result in a cached variable, see
<http://www.gnu.org/software/autoconf/manual/html_node/Caching-Results.html>.

That way, the sub configure script will not re-run the test but use the
cached result if a cache file is used, but also the sub package is still
completely usable if used standalone.

Hope that helps.

Cheers,
Ralf