Necessity of both KokkosKernels_ENABLED_COMPONENTS and KokkosKernels_ENABLE_...?

[cwpearson]

We have this guy:

• KokkosKernels_ENABLED_COMPONENTS

And also these guys:

• KokkosKernels_ENABLE_ALL_COMPONENTS
• KokkosKernels_ENABLE_BATCHED
• KokkosKernels_ENABLE_BLAS
• KokkosKernels_ENABLE_LAPACK
• KokkosKernels_ENABLE_SPARSE
• KokkosKernels_ENABLE_GRAPH
• KokkosKernels_ENABLE_ODE

[cwpearson]

I think KokkosKernels_ENABLED_COMPONENTS is just used in kokkoskernels_tribits.cmake to check if all the components requested by Trilinos (?) are inside this variable.

It probably makes more sense for this code to be reworked to check the KokkosKernels_ENABLE family of options instead, and drop KokkosKernels_ENABLED_COMPONENTS entirely?

[cwpearson]

Any insight re the Trilinos integration @ndellingwood?

[ndellingwood]

@cwpearson so the options were originally named as you posted (i.e. KokkosKernels_ENABLE_BLAS etc), but in Trilinos builds there was some TriBITs variable naming and interaction that overlapped with the KokkosKernels naming but occurred prior to processing of the KokkosKernels_ENABLE_{Component} macros, in particular this resulted in enable of KokkosKernels_ENABLE_BLAS specifically which broke with the cmake logic with the way individually enabled processed components were enabled - basically the default with Trilinos was that BLAS was enabled and no other component

[ndellingwood]

Here is cross-reference to the PR with the renaming of the options to workaround the overload/naming collision with TriBITS: #1641

[ndellingwood]

@cwpearson my first read of the question may have been a misinterpretation - you're talking specifically about KokkosKernels_ENABLED_COMPONENTS and not the individual options e.g. KokkosKernels_ENABLE_COMPONENT_BLAS ?
If you'd prefer to remove KokkosKernels_ENABLED_COMPONENTS, but ensure the cmake logic with Trilinos builds holds such that the default behavior is that all components are enabled unless specific individual options are provided, please do so 👍

[ndellingwood]

Documentation-wise, we do need to update https://github.com/kokkos/kokkos-kernels/wiki/Building#component-options for the individual components