Allow Kokkos Comm as an external Trilinos package

[cwpearson]

Add the machinery TriBITS needs to treat Kokkos Comm as a Trilinos package.

• Trilinos build instructions in docs
• (optional, non-blocking) Trilinos integration PR test

The idea is you will be able to link kokkos-comm into the Trilinos packages directory

ln -s $(realpath kokkos-comm) $(realpath Trilinos)/packages/kokkos-comm

And configure Trilinos with

  -DTPL_ENABLE_MPI=ON \
  -DTrilinos_ENABLE_KokkosComm=ON \

I am definitely not a TriBITS expert.

Patch needed on top of Trilinos f532ad8d3c49fa5143138b365bf04473b4ab2a27

diff --git a/PackagesList.cmake b/PackagesList.cmake
index 948854bb8f3..d66e66843a1 100644
--- a/PackagesList.cmake
+++ b/PackagesList.cmake
@@ -26,6 +26,7 @@ TRIBITS_REPOSITORY_DEFINE_PACKAGES(
   Shards                packages/shards                   PT
   Triutils              packages/triutils                 ST
   EpetraExt             packages/epetraext                ST
+  KokkosComm            packages/kokkos-comm              EX
   Tpetra                packages/tpetra                   PT
   TrilinosSS            packages/common/auxiliarySoftware/SuiteSparse PT # Auxiliary software.
   Domi                  packages/domi                     PT
@@ -121,6 +122,7 @@ TRIBITS_ALLOW_MISSING_EXTERNAL_PACKAGES(xSDKTrilinos)
 TRIBITS_ALLOW_MISSING_EXTERNAL_PACKAGES(SGM)
 TRIBITS_ALLOW_MISSING_EXTERNAL_PACKAGES(UMR)
 TRIBITS_ALLOW_MISSING_EXTERNAL_PACKAGES(TrilinosLinearSolvers)
+TRIBITS_ALLOW_MISSING_EXTERNAL_PACKAGES(KokkosComm)
 
 # TRILFRAME-500
 TRIBITS_ALLOW_MISSING_EXTERNAL_PACKAGES(Rythmos)    # 27115 targets
diff --git a/packages/tpetra/CMakeLists.txt b/packages/tpetra/CMakeLists.txt
index c71af6269c2..cd2f3997dc2 100644
--- a/packages/tpetra/CMakeLists.txt
+++ b/packages/tpetra/CMakeLists.txt
@@ -816,6 +816,21 @@ IF (NOT DEFINED ${PACKAGE_NAME}_ENABLE_mpi_advance)
 ENDIF ()
 ASSERT_DEFINED (${PACKAGE_NAME}_ENABLE_mpi_advance)
 
+# ============================================================
+# Kokkos Comm
+# ============================================================
+
+IF (NOT DEFINED ${PACKAGE_NAME}_ENABLE_KokkosComm)
+  IF (DEFINED TpetraCore_ENABLE_KokkosComm)
+    SET (${PACKAGE_NAME}_ENABLE_KokkosComm "${TpetraCore_ENABLE_KokkosComm}")
+  ELSEIF (DEFINED TPL_ENABLE_KokkosComm)
+    SET (${PACKAGE_NAME}_ENABLE_KokkosComm "${TPL_ENABLE_KokkosComm}")
+  ELSE ()
+    SET (${PACKAGE_NAME}_ENABLE_KokkosComm OFF)
+  ENDIF ()
+ENDIF ()
+ASSERT_DEFINED (${PACKAGE_NAME}_ENABLE_KokkosComm)
+
 # ============================================================
 # Scalar types
 # ============================================================
diff --git a/packages/tpetra/core/cmake/Dependencies.cmake b/packages/tpetra/core/cmake/Dependencies.cmake
index 7f483312feb..26ab5564275 100644
--- a/packages/tpetra/core/cmake/Dependencies.cmake
+++ b/packages/tpetra/core/cmake/Dependencies.cmake
@@ -1,5 +1,5 @@
 TRIBITS_PACKAGE_DEFINE_DEPENDENCIES(
   LIB_REQUIRED_PACKAGES Teuchos Kokkos TeuchosKokkosCompat TeuchosKokkosComm KokkosKernels
-  LIB_OPTIONAL_PACKAGES Epetra TpetraTSQR TeuchosNumerics
+  LIB_OPTIONAL_PACKAGES Epetra TpetraTSQR TeuchosNumerics KokkosComm
   LIB_OPTIONAL_TPLS MPI CUDA QD quadmath mpi_advance
 )
diff --git a/packages/tpetra/core/cmake/TpetraCore_config.h.in b/packages/tpetra/core/cmake/TpetraCore_config.h.in
index f2980a394ff..a66977670f3 100644
--- a/packages/tpetra/core/cmake/TpetraCore_config.h.in
+++ b/packages/tpetra/core/cmake/TpetraCore_config.h.in
@@ -34,6 +34,9 @@
 /* Determine if we have the mpi_advance TPL */
 #cmakedefine HAVE_TPETRACORE_MPI_ADVANCE
 
+/* Determine if we have the KokkosComm TPL */
+#cmakedefine HAVE_TPETRACORE_KOKKOSCOMM
+
 /* Determine if we have QD */
 #cmakedefine HAVE_TPETRACORE_QD
 #ifdef HAVE_TPETRACORE_QD
diff --git a/packages/tpetra/core/test/CMakeLists.txt b/packages/tpetra/core/test/CMakeLists.txt
index a53e978403c..3ae1934874f 100644
--- a/packages/tpetra/core/test/CMakeLists.txt
+++ b/packages/tpetra/core/test/CMakeLists.txt
@@ -22,6 +22,7 @@ ADD_SUBDIRECTORIES(
   ImportExport
   ImportExport2
   inout
+  KokkosComm
   LinearProblem
   Map
   MatrixMatrix
diff --git a/packages/tpetra/core/test/KokkosComm/CMakeLists.txt b/packages/tpetra/core/test/KokkosComm/CMakeLists.txt
new file mode 100644
index 00000000000..6e55de9b502
--- /dev/null
+++ b/packages/tpetra/core/test/KokkosComm/CMakeLists.txt
@@ -0,0 +1,11 @@
+TRIBITS_SET_AND_INC_DIRS(DIR ${CMAKE_CURRENT_SOURCE_DIR})
+
+IF (${PACKAGE_NAME}_ENABLE_KokkosComm)
+
+  TRIBITS_ADD_EXECUTABLE_AND_TEST(
+    KokkosComm_include
+    SOURCES
+      KokkosComm_include.cpp
+    STANDARD_PASS_OUTPUT
+    )
+ENDIF()
\ No newline at end of file
diff --git a/packages/tpetra/core/test/KokkosComm/KokkosComm_include.cpp b/packages/tpetra/core/test/KokkosComm/KokkosComm_include.cpp
new file mode 100644
index 00000000000..d9d90e9a717
--- /dev/null
+++ b/packages/tpetra/core/test/KokkosComm/KokkosComm_include.cpp
@@ -0,0 +1,15 @@
+// @HEADER
+// *****************************************************************************
+//          Tpetra: Templated Linear Algebra Services Package
+//
+// Copyright 2008 NTESS and the Tpetra contributors.
+// SPDX-License-Identifier: BSD-3-Clause
+// *****************************************************************************
+// @HEADER
+
+#include <KokkosComm/KokkosComm.hpp>
+
+int main(int argc, char* argv[])
+{
+  return 0;
+}
\ No newline at end of file

[nicoleavans]

Everything looks good to me as discussed prior, though it's important to point out I'm unfamiliar with tribits.

[cwpearson]

@nicoleavans could you please try following along with the instructions this PR adds to the docs in combination with trilinos/Trilinos#14135 and see if it seems to work together for you?

[cedricchevalier19]

Looks OK.

[cedricchevalier19]

Suggested change

	# install(
	# TARGETS KokkosComm_all_libs
	# EXPORT KokkosCommTargets
	# COMPONENT KokkosComm
	# )

[dssgabriel]

Apart from the COMPONENT KokkosComm lines, this section looks to be duplicated from the one below (lines 146-154). I can't seem to highlight the full line range in this comment.