Eigen warnings with gcc 4.7.2 and above

[mparsani]

Compiling the kernel with gcc 4.7.2 and above leads to many warnings related to eigen, e.g.
/scratch/home0/pmatteo/research/workspace/codes/coolfluid3/kernel/include/Eigen/src/Core/DenseBase.h: In instantiation of ‘class Eigen::DenseBase<Eigen::Matrix<double, 2, 12> >’:
/scratch/home0/pmatteo/research/workspace/codes/coolfluid3/kernel/include/Eigen/src/Core/MatrixBase.h:61:34: required from ‘class Eigen::MatrixBase<Eigen::Matrix<double, 2, 12> >’
/scratch/home0/pmatteo/research/workspace/codes/coolfluid3/kernel/include/Eigen/src/Core/PlainObjectBase.h:52:7: required from ‘class Eigen::PlainObjectBase<Eigen::Matrix<double, 2, 12> >’
/scratch/home0/pmatteo/research/workspace/codes/coolfluid3/kernel/include/Eigen/src/Core/Matrix.h:140:7: required from ‘class Eigen::Matrix<double, 2, 12>’
/scratch/home0/pmatteo/research/workspace/codes/coolfluid3/kernel/cf3/mesh/Integrators/GaussImplementation.hpp:317:3: required from here
/scratch/home0/pmatteo/research/workspace/codes/coolfluid3/kernel/include/Eigen/src/Core/DenseBase.h:103:10: warning: enumeral mismatch in conditional expression: ‘Eigen::internal::size_at_compile_time<2, 12>::’ vs ‘Eigen::internal::traits<Eigen::Matrix<double, 2, 12> >::’ [-Wenum-compare]

It seems it is an Eigen's issue which has been fixed in the 3.1.1 version (http://listengine.tuxfamily.org/lists.tuxfamily.org/eigen/2012/10/msg00066.html)
Is there any drawback if Eiegn will be updated in kernel?

[mparsani]

I have looked a little bit Eigen 3.1.3. New header files have been added and few others have been removed. It seems everything compile if I update it but I let the cf3 experts to do it properly. :-)

[barche]

A while ago I added code to detect the system Eigen: https://github.com/coolfluid/coolfluid3/blob/master/cmake/DetectSoftware.cmake#L5

I would propose to remove the current Eigen code from the tree at some point. Note that just installing eigen in your deps root (the install script does it) should fix the problem, since system Eigen takes precedence over the version we supply.

[mparsani]

Hi Bart, thank you for your feedback. I have used cookup.pl and yes, most of the warning are gone.
Maybe a naive question: is there any specific reason to have Eigen in the kernel and not like all other dependencies? Is it because the framework is tied up around it?

[barche]

I think at the time there were problems with some versions of Eigen, and the Eigen website also recommended including it in the source. Neither of those seem to apply now, so I'd just recommend to use the latest version that you can get.

[wdeconinck]

Could we then just remove Eigen from the cf3 sources...

I wouldn't mind.

[tlmquintino]

Yeah, I second that. Lets just remove them from the cf3 sources.