Add option to install dynamic library?

[RemiLehe]

Would it make sense to add an option to install openPMD-api as a dynamic library? (instead of a static library)

The main use case would be using openPMD-api in a REPL setting, with cling.
My understanding is that cling can only load dynamic libraries.

[ax3l]

Hi Rémi,

you can install dynamic libraries just by passing -DBUILD_SHARED_LIBS=ON to the cmake call. In CMake, the default for libraries is just static so I didn't change it and expose it with the typical control flags.

https://openpmd-api.readthedocs.io/en/0.8.0-alpha/dev/buildoptions.html#shared-or-static

Please note that you can either build a shared or a static lib at a time.

I will add a +shared variant to spack as well:
spack/spack#10847

I will probably change the default to shared in CMake itself for all install methods (this way).

My understanding is that cling can only load dynamic libraries.

Yes, for a JIT shared linking is the most logical and in cling the supported way: https://root-forum.cern.ch/t/jit-and-libraries/20309/11

[RemiLehe]

Great that there is the option -DBUILD_SHARED_LIBS=ON!
Sorry that I missed it!

[ax3l]

No problem, I will probably change the default to shared in the future as well (so one has to explicitly request static libs with -DBUILD_SHARED_LIBS=OFF).
Noted in #505

[ax3l]

I also updated the conda-forge recipe, so that it will install shared libraries by default as well: conda-forge/openpmd-api-feedstock#25

In case the PR works, this will take some hours to land.