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Development version of plumed 2
https://www.plumed.org
GNU Lesser General Public License v3.0
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Configure: Throw an error instead of a warning when ArrayFire cannot be used? #660

Open RemiLacroix-IDRIS opened 3 years ago

RemiLacroix-IDRIS commented 3 years ago

Hi,

We run into some issues lately because we missed that ArrayFire couldn't be used at configure and only discovered that much later.

$ ./configure ... --enable-af_cpu=no --enable-af_cuda=yes --enable-af_ocl=no
...
checking arrayfire.h usability... yes
checking arrayfire.h presence... yes
checking for arrayfire.h... yes
checking for library containing af_is_double... no
configure: WARNING: cannot enable __PLUMED_HAS_ARRAYFIRE
...

We would have thought that when explicitly using one of the --enable-af_* options the configure script would throw an error instead of a warning.

Is there any reason to keep this as a warning?

Best regards, Rémi

GiovanniBussi commented 3 years ago

Hi, thanks for this feedback.

The underlying logic is that a feature can either be enabled (with --enable-feature) or disabled (with --disable-feature). By default, some are enabled (e.g. MPI) and some are disabled (e.g. arrayfire).

Having that enabled features result in an error if the needed libraries are not present would result in undesired errors for features that are on by default when the corresponding libraries are not present.

The only solution that comes to my mind would be to have a third value, e.g. yes/no/ifavailable, and use ifavailable as a default instead of yes. In this manner, explicitly requested features could lead to a failure if the corresponding library is not present.

What do you think?

Giovanni

RemiLacroix-IDRIS commented 3 years ago

Hi,

The only solution that comes to my mind would be to have a third value, e.g. yes/no/ifavailable, and use ifavailable as a default instead of yes. In this manner, explicitly requested features could lead to a failure if the corresponding library is not present.

That would work perfectly.

Another solution would be to have an new option in the configure script to switch from a warning mode to an error mode, something like --fail-on-missing-libs.

Rémi

carlocamilloni commented 3 years ago

I like Giovanni suggestions of using three if available for default options