Add installation testing option

[jjwilke]

Allows easier testing Jenkins of Kokkos installations.

• Sets all tests to link to alias Kokkos::kokkos
• Calls find_package(Kokkos) instead of building Kokkos when option is set

[crtrott]

I tested this with a CUDA build.

[jjwilke]

I guess this is okay (it works). We could have also done -DKokkos_ROOT=...

[masterleinad]

The enabled tests depend on the backends enabled here, don't they? Hence, these should match.

[masterleinad]

I think I'm fine with this once the CI configuration is fixed.
It might also be a good idea to hide this some more from the user by making it an internal variable.

[masterleinad]

What this is doing effectively is to disable compiling the library and just run the tests.
Hence, I would rather name it DISABLE_COMPILING or similar and make sure Kokkos_ENABLE_TESTS=ON.

[crtrott]

Ok it doesn't look like this fully works. The config is doing something in between where it doesn't get the enabled spaces from the installed version. It would work if I would just give matching options for the second configure but do we want that?

[jjwilke]

@masterleinad Yeah, we should probaly just make it an internal variable.
@crtrott We would need to make the configurations match. We could make this more sophisticated (and also test kokkos_check), but that's probably overkill for now.

[crtrott]

So I tried something where I stuck the check just before KOKKOS_SETUP_BUILD_ENVIRONMENT in the main CMakeLists:

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4ec1bac..24fde2a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -151,6 +151,17 @@ INCLUDE(${KOKKOS_SRC_PATH}/cmake/kokkos_check_env.cmake)
 #
 KOKKOS_OPTION(INSTALL_TESTING OFF BOOL "Whether to build tests and examples against installation")

+# Short circuit all the rest of the processing if we just build tests against installed Kokkos
+IF(KOKKOS_INSTALL_TESTING)
+  SET(KOKKOS_ENABLE_TESTS ON)
+  KOKKOS_PACKAGE_DECL()
+  FIND_PACKAGE(Kokkos REQUIRED)
+  add_subdirectory(core)
+  add_subdirectory(containers)
+  add_subdirectory(algorithms)
+ELSE()
+
+
 # The build environment setup goes in the following steps
 # 1) Check all the enable options. This includes checking Kokkos_DEVICES
 # 2) Check the compiler ID (type and version)
@@ -279,3 +290,6 @@ IF (HAS_PARENT)
     SET_PROPERTY(GLOBAL PROPERTY Kokkos_ENABLE_${DEV} ON)
   ENDFOREACH()
 ENDIF()
+
+# End for not INSTALL_TESTING
+ENDIF()

And that seems to work properly. You only need to set compiler and Kokkos_INSTALL_TESTING and everything else comes from the installed Kokkos instead of first trying to do a configuration of Kokkos and overwriting those settings via a find package.

[masterleinad]

Creating a separate directory with

cmake_minimum_required(VERSION 3.10)
project(KokkosTestInstall CXX)

find_package(Kokkos 3.1 REQUIRED QUIET)

SET(PACKAGE_NAME KOKKOS)
SET(KOKKOS_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/..)
SET(KOKKOS_ENABLE_TESTS ON)
SET(KOKKOS_INSTALL_TESTING ON)

include(${PROJECT_SOURCE_DIR}/../cmake/fake_tribits.cmake)
include(${PROJECT_SOURCE_DIR}/../cmake/kokkos_tribits.cmake)

ADD_SUBDIRECTORY(${PROJECT_SOURCE_DIR}/../core/ core)
ADD_SUBDIRECTORY(${PROJECT_SOURCE_DIR}/../algorithms algorithms)
ADD_SUBDIRECTORY(${PROJECT_SOURCE_DIR}/../containers containers)

would an alternative to be sure to not mess with the configuration of the found package.

[jjwilke]

I pushed a refactor that combines all the recent feedback (I think).

• It receives the configuration from the imported package
• It skips any local configuration
• It uses an internal cache variable for the configuration

I kept the name Kokkos_INSTALL_TESTING. This seems a more accurate description than DISABLE_COMPILING?

[crtrott]

Yeah this looks good. Let me push again the Jenkins config file change I added which got nuked by your force push :-)

[masterleinad]

I kept the name Kokkos_INSTALL_TESTING. This seems a more accurate description than DISABLE_COMPILING?

Now, Kokkos_INSTALL_TESTING implies Kokkos_ENABLE_TESTS which it didn't before IIRC. The name is fine with me then.
I'm a bit torn between handling all the configuration stuff in CMakeLists.txt and having a separate project (which is probably closer to what a user would have). Anyway, if both of you are in favor of doing it inline, that's OK.

[crtrott]

I think this is fine. I am also happy with the Kokkos_INSTALL_TESTING directly implying Kokkos_ENABLE_TESTS. That INSTALL_TESTING option anyway implies doing something completely different.

[crtrott]

And the install test worked in Jenkins. Great!