kokkos · cwpearson · Jun 17, 2025 · Jun 18, 2025 · Jun 18, 2025 · Jun 18, 2025
diff --git a/.github/workflows/linux-trilinos.yaml b/.github/workflows/linux-trilinos.yaml
@@ -0,0 +1,59 @@
+name: Linux-Trilinos-Integration
+
+# only run most recent workflow in branch
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+on:
+  pull_request:
+    paths-ignore:
+    - README.md
+    - 'docs/**'
+    types: [ opened, reopened, synchronize ]
+
+jobs:
+  Develop-OpenMPI:
+    continue-on-error: true # failure won't fail the workflow
+    env:
+      TRILINOS_BUILD: ${{ github.workspace }}/trilinos-build
+      TRILINOS_INSTALL: ${{ github.workspace }}/trilinos-install
+      COMM_SRC: ${{ github.workspace }}
+    runs-on: ubuntu-latest
+    timeout-minutes: 40 # Trilinos build takes ~20 minutes
+    steps:
+      - name: Install MPI
+        run: |
+          sudo apt-get update && sudo apt-get install -y libopenmpi-dev openmpi-bin cmake
+          which mpirun
+          mpirun --version
+          which mpicxx
+          mpicxx --version
+      - name: Install openblas
+        run: sudo apt-get install libopenblas-dev
+      - name: Check out repository code
+        uses: actions/checkout@v4
+      - name: Check out Trilinos
+        uses: actions/checkout@v4
+        with:
+          repository: trilinos/Trilinos
+          fetch-depth: 1
+          ref: develop # FIXME: master, once master has support
+          path: trilinos
+      - name: symlink kokkos-comm
+        run: |
+          ln -s "${{ github.workspace }}" trilinos/packages/kokkos-comm
+      - name: Configure Trilinos
+        run: >
+          cmake -S trilinos -B "$TRILINOS_BUILD" \
+            -DCMAKE_INSTALL_PREFIX="$TRILINOS_INSTALL" \
+            -DTPL_ENABLE_MPI=ON \
+            -DTrilinos_ENABLE_KokkosComm=ON \
+            -DTrilinos_ENABLE_Tpetra=ON \
+              -DTpetra_ENABLE_TESTS=ON
+      - name: Build Trilinos
+        run: cmake --build "$TRILINOS_BUILD" --parallel $(nproc)
+      - name: Test Exists
+        run: "[ -f \"$TRILINOS_BUILD/packages/tpetra/core/test/KokkosComm/TpetraCore_KokkosComm_include.exe\" ] || exit 1"
+      - name: Install Trilinos
+        run: cmake --build "$TRILINOS_BUILD" --target install
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -14,20 +14,48 @@
 #
 #@HEADER
 
+# Support two different build modes: 
+#   Standalone
+#   As a Trilinos package
+if(COMMAND TRIBITS_PACKAGE_DECL)
+  set(KOKKOSCOMM_HAS_TRILINOS ON CACHE BOOL "")
+else()
+  SET(KOKKOSCOMM_HAS_TRILINOS OFF CACHE BOOL "")
+endif()
+message(STATUS "KOKKOSCOMM_HAS_TRILINOS: ${KOKKOSCOMM_HAS_TRILINOS}")
+
 # 3.9: MPI::MPI_CXX
 # 3.12: CMAKE_PROJECT_VERSION_MAJOR
 # 3.15: PUBLIC_HEADER files for interface libraries
 # 3.23: FILE_SETs for easy export of header-only libraries
 cmake_minimum_required(VERSION 3.23)
 
-project(
-  KokkosComm
-  LANGUAGES
-    CXX
-  VERSION 0.2.0
-  DESCRIPTION "Experimental MPI interfaces (and more!) for the Kokkos C++ Performance Portability Programming ecosystem"
-  HOMEPAGE_URL "https://kokkos.org/kokkos-comm/"
-)
+set(KOKKOSCOMM_VERSION_MAJOR 0 CACHE STRING "" FORCE)
+set(KOKKOSCOMM_VERSION_MINOR 2 CACHE STRING "" FORCE)
+set(KOKKOSCOMM_VERSION_PATCH 0 CACHE STRING "" FORCE)
+set(KOKKOSCOMM_VERSION_STRING "${KOKKOSCOMM_VERSION_MAJOR}.${KOKKOSCOMM_VERSION_MINOR}.${KOKKOSCOMM_VERSION_PATCH}" CACHE STRING "" FORCE)
+
+SET(PACKAGE_NAME KokkosComm)
+SET(${PACKAGE_NAME}_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
+SET(${PACKAGE_NAME}_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
+
+if (KOKKOSCOMM_HAS_TRILINOS)
+  tribits_package(KokkosComm)
+
+  SET(PACKAGE_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
+  STRING(TOUPPER ${PACKAGE_NAME} PACKAGE_NAME_UC)
+
+else()
+  project(
+    KokkosComm
+    LANGUAGES
+      CXX
+    VERSION "${KOKKOSCOMM_VERSION_STRING}"
+    DESCRIPTION "Experimental MPI interfaces (and more!) for the Kokkos C++ Performance Portability Programming ecosystem"
+    HOMEPAGE_URL "https://kokkos.org/kokkos-comm/"
+  )
+endif()
+
 
 include(cmake/mpi-vendor.cmake)
 
@@ -40,10 +68,24 @@ set(KOKKOSCOMM_ENABLE_PERFTESTS ${KokkosComm_ENABLE_PERFTESTS} CACHE BOOL "" FOR
 set(KOKKOSCOMM_ENABLE_TESTS ${KokkosComm_ENABLE_TESTS} CACHE BOOL "" FORCE)
 set(KOKKOSCOMM_ENABLE_MPI ${KokkosComm_ENABLE_MPI} CACHE BOOL "" FORCE)
 
-find_package(Kokkos REQUIRED)
-if(KOKKOSCOMM_ENABLE_MPI)
-  find_package(MPI REQUIRED)
+if (KOKKOSCOMM_HAS_TRILINOS)
+  if (TPL_ENABLE_MPI)
+    if (NOT KOKKOSCOMM_ENABLE_MPI)
+      message(WARNING "TPL_ENABLE_MPI is set. Overriding KOKKOSCOMM_ENABLE_MPI to ON")
+      set(KOKKOSCOMM_ENABLE_MPI ON CACHE BOOL "" FORCE)
+    endif()
+  endif()
 endif()
+
+if (KOKKOSCOMM_HAS_TRILINOS)
+  # Trilinos will "find" Kokkos and MPI
+else()
+  find_package(Kokkos REQUIRED)
+  if(KOKKOSCOMM_ENABLE_MPI)
+    find_package(MPI REQUIRED)
+  endif()
+endif()
+
 kokkoscomm_set_mpi_vendor_variables()
 
 add_subdirectory(src/KokkosComm)
@@ -61,41 +103,45 @@ include(CMakePackageConfigHelpers)
 include(GNUInstallDirs)
 
 # Generate version config header
-set(KOKKOSCOMM_VERSION_MAJOR ${CMAKE_PROJECT_VERSION_MAJOR} CACHE STRING "" FORCE)
-set(KOKKOSCOMM_VERSION_MINOR ${CMAKE_PROJECT_VERSION_MINOR} CACHE STRING "" FORCE)
-set(KOKKOSCOMM_VERSION_PATCH ${CMAKE_PROJECT_VERSION_PATCH} CACHE STRING "" FORCE)
+
 configure_file(
-  ${PROJECT_SOURCE_DIR}/cmake/KokkosComm_config.hpp.in
-  ${PROJECT_BINARY_DIR}/src/KokkosComm/config.hpp
+  ${CMAKE_CURRENT_SOURCE_DIR}/cmake/KokkosComm_config.hpp.in
+  ${CMAKE_CURRENT_BINARY_DIR}/src/KokkosComm/config.hpp
   @ONLY
 )
 
-# Generate package config file
-configure_package_config_file(
-  ${PROJECT_SOURCE_DIR}/cmake/Config.cmake.in
-  ${PROJECT_BINARY_DIR}/cmake/KokkosComm/KokkosCommConfig.cmake
-  INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/KokkosComm
-  NO_SET_AND_CHECK_MACRO
-  NO_CHECK_REQUIRED_COMPONENTS_MACRO
-)
+# required by TriBITS
+if (KOKKOSCOMM_HAS_TRILINOS)
+  tribits_package_postprocess()
+else()
+  # Generate package config file
+  configure_package_config_file(
+    ${CMAKE_CURRENT_SOURCE_DIR}/cmake/Config.cmake.in
+    ${CMAKE_CURRENT_BINARY_DIR}/cmake/KokkosComm/KokkosCommConfig.cmake
+    INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/KokkosComm
+    NO_SET_AND_CHECK_MACRO
+    NO_CHECK_REQUIRED_COMPONENTS_MACRO
+  )
 
-# Generate package version file
-write_basic_package_version_file(
-  ${PROJECT_BINARY_DIR}/cmake/KokkosComm/KokkosCommVersion.cmake
-  COMPATIBILITY SameMajorVersion
-  ARCH_INDEPENDENT # KokkosComm is a header-only library
-)
+  # Generate package version file
+  write_basic_package_version_file(
+    ${CMAKE_CURRENT_BINARY_DIR}/cmake/KokkosComm/KokkosCommVersion.cmake
+    VERSION "${KOKKOSCOMM_VERSION_STRING}"
+    COMPATIBILITY SameMajorVersion
+    ARCH_INDEPENDENT # KokkosComm is a header-only library
+  )
 
-# Install CMake package files
-install(
-  FILES
-    ${PROJECT_BINARY_DIR}/cmake/KokkosComm/KokkosCommConfig.cmake
-    ${PROJECT_BINARY_DIR}/cmake/KokkosComm/KokkosCommVersion.cmake
-  DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/KokkosComm
-)
-install(
-  EXPORT KokkosCommTargets
-  FILE KokkosCommTargets.cmake
-  NAMESPACE KokkosComm::
-  DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/KokkosComm
-)
+  # Install CMake package files
+  install(
+    FILES
+      ${PROJECT_BINARY_DIR}/cmake/KokkosComm/KokkosCommConfig.cmake
+      ${PROJECT_BINARY_DIR}/cmake/KokkosComm/KokkosCommVersion.cmake
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/KokkosComm
+  )
+  install(
+    EXPORT KokkosCommTargets
+    FILE KokkosCommTargets.cmake
+    NAMESPACE KokkosComm::
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/KokkosComm
+  )
+endif()
diff --git a/cmake/Dependencies.cmake b/cmake/Dependencies.cmake
@@ -0,0 +1,13 @@
+# for Trilinos TriBITS build system
+
+set(LIB_REQUIRED_DEP_PACKAGES Kokkos) # we require Kokkos
+set(LIB_OPTIONAL_DEP_PACKAGES)
+
+set(TEST_REQUIRED_DEP_PACKAGES)
+set(TEST_OPTIONAL_DEP_PACKAGES)
+
+set(LIB_REQUIRED_DEP_TPLS)
+set(LIB_OPTIONAL_DEP_TPLS MPI) # Optionally require MPI
+
+set(TEST_REQUIRED_DEP_TPLS)
+set(TEST_OPTIONAL_DEP_TPLS)
diff --git a/docs/dev/trilinos.rst b/docs/dev/trilinos.rst
@@ -0,0 +1,31 @@
+******************************
+As a Trilinos external package
+******************************
+
+Kokkos Comm can be used as an external package in Trilinos as of https://github.com/trilinos/Trilinos/pull/14135.
+
+.. code-block:: console
+
+  # acquire trilinos
+  git clone https://github.com/trilinos/Trilinos.git
+
+  # symlink kokkos-comm source into Trilinos
+  ln -s kokkos-comm trilinos/packages/kokkos-comm
+
+  # Build Trilinos
+  cmake -S trilinos -B "$TRILINOS_BUILD" \
+    -DCMAKE_INSTALL_PREFIX="$TRILINOS_INSTALL" \
+    -DTPL_ENABLE_MPI=ON \
+    -DTrilinos_ENABLE_KokkosComm=ON \
+    -DTrilinos_ENABLE_Tpetra=ON \
+      -DTpetra_ENABLE_TESTS=ON
+
+Look for something like the following in the Trilinos configure output:
+
+.. code-block:: text
+
+  ...
+  Final set of enabled top-level packages:  Kokkos Teuchos KokkosKernels KokkosComm Tpetra 5
+  ...
+  Final set of enabled external packages/TPLs:  MPI BLAS LAPACK DLlib 4
+  ...
diff --git a/docs/index.rst b/docs/index.rst
@@ -48,6 +48,7 @@ Documentation Content
    dev/testing
    dev/mpi
    dev/docs
+   dev/trilinos
 
 
 Indices and tables