Re: configure.ac and Dolfin.h

[c.]

On 2 Mar 2014, at 07:58, c. <address@hidden> wrote:

> 
> On 1 Mar 2014, at 15:56, c. <address@hidden> wrote:
> 
>> 
>> On 1 Mar 2014, at 15:31, Juan Pablo Carbajal <address@hidden> wrote:
>>>> 
>>>> 
>>>> Why not instead (or in addition to that) use the output of pkg-config?
>>>> This is the standard way to detect flags to be added when
>>>> compiling/linking against a library.
>>>> 
>>>> On my Debian unstable system, the eigen3 include directory is included
>>>> in the output of "pkg-config --cflags dolfin".
>>>> 
>>>> --
>>>> .''`.    Sébastien Villemot
>>>> : :' :    Debian Developer
>>>> `. `'     http://www.dynare.org/sebastien
>>>> `-      GPG Key: 4096R/381A7594
>>>> 
>>> 
>>> Sebastien,
>>> 
>>> Because I do not know how to do that. Autotools and friends are not
>>> the easiest tools to learn how to use...
>>> If you have an example that shows what you mean, then I would be happy
>>> to fix the code.
>> 
>> I can do that, I'll prepare a patch, but nontheless it's good to be able
>> to manually tell configure where libraries are, so I will leave your option 
>> too.
>> 
>> c.
> 
> Actually, 
> 
> Now that I think better about it, while I COULD, prepare this patch, working
> on this sounds like a nice little project for a would-be GSoC student willing 
> to work on fem-fenics.
> 
> So, Eugenio, would you like to give it a try yourself?
> You can find some interesting information to use as a starting point for 
> autotools+pkg
> config here:
> 
> https://www.flameeyes.eu/autotools-mythbuster/pkgconfig/index.html

Also, 
Octave itself uses pkg-config to discover configuration options for some of its 
dependencies
like freetype or Qt, so you can find usage examples for the PKG_CHECK_MODULES 
macro in Octave's
own configure.ac:

http://hg.savannah.gnu.org/hgweb/octave/file/f958e8cd6348/configure.ac

Feel free to ask if you need more directions.

> HTH,
> c.