modularize cvmix as cmake module

cmake/BuildCVMix.cmake

@@ -0,0 +1,189 @@
+# BuildCVMix.cmake
+# External project build for CVMix library
+# Follows the pattern of BuildNetCDF.cmake for consistency
+
+include(ExternalProject)
+include(GNUInstallDirs)
+
+# Set installation prefix for built CVMix library
+set(CVMIX_INSTALL_PREFIX ${CMAKE_BINARY_DIR}/external/cvmix)
+
+# Create directories early so CMake doesn't complain about non-existent paths
+file(MAKE_DIRECTORY ${CVMIX_INSTALL_PREFIX})
+file(MAKE_DIRECTORY ${CVMIX_INSTALL_PREFIX}/lib)
+file(MAKE_DIRECTORY ${CVMIX_INSTALL_PREFIX}/include)
+file(MAKE_DIRECTORY ${CVMIX_INSTALL_PREFIX}/include/cvmix)
+
+# CVMix git repository and version
+set(CVMIX_GIT_REPOSITORY "https://github.com/CVMix/CVMix-src.git")
+set(CVMIX_GIT_TAG "v1.0.0")  # Can be made configurable via cache variable
+
+# CRITICAL: Set common cmake args for CVMix build
+# CVMix must be compiled with compatible Fortran flags to link properly with FESOM2
+set(CVMIX_CMAKE_ARGS
+    -DCMAKE_INSTALL_PREFIX=${CVMIX_INSTALL_PREFIX}
+    -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
+    -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
+    -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
+    -DCMAKE_Fortran_COMPILER=${CMAKE_Fortran_COMPILER}
+    -DCMAKE_Fortran_MODULE_DIRECTORY=${CVMIX_INSTALL_PREFIX}/include
+    -DCMAKE_INSTALL_LIBDIR=lib
+    -DCMAKE_POSITION_INDEPENDENT_CODE=ON
+)
+
+# Pass CMAKE_Fortran_FLAGS to CVMix if set
+# This ensures CVMix is compiled with the same flags as FESOM2 (e.g., -fdefault-real-8, -r8)
+if(CMAKE_Fortran_FLAGS)
+    list(APPEND CVMIX_CMAKE_ARGS
+        "-DCMAKE_Fortran_FLAGS=${CMAKE_Fortran_FLAGS}"
+    )
+    message(STATUS "CVMix will be built with CMAKE_Fortran_FLAGS: ${CMAKE_Fortran_FLAGS}")
+endif()
+
+# Pass build-type-specific flags if they exist
+if(CMAKE_Fortran_FLAGS_RELEASE AND CMAKE_BUILD_TYPE MATCHES "Release")
+    list(APPEND CVMIX_CMAKE_ARGS
+        "-DCMAKE_Fortran_FLAGS_RELEASE=${CMAKE_Fortran_FLAGS_RELEASE}"
+    )
+endif()
+
+if(CMAKE_Fortran_FLAGS_DEBUG AND CMAKE_BUILD_TYPE MATCHES "Debug")
+    list(APPEND CVMIX_CMAKE_ARGS
+        "-DCMAKE_Fortran_FLAGS_DEBUG=${CMAKE_Fortran_FLAGS_DEBUG}"
+    )
+endif()
+
+# Intel compiler: Ensure critical real/integer kind flags are passed
+# FESOM2 uses -r8 (8-byte reals) and -i4 (4-byte integers) for Intel
+if(CMAKE_Fortran_COMPILER_ID MATCHES "Intel")
+    # Check if -r8 or similar flags are in CMAKE_Fortran_FLAGS
+    # If not explicitly set, add them to ensure compatibility
+    string(FIND "${CMAKE_Fortran_FLAGS}" "-r8" has_r8)
+    string(FIND "${CMAKE_Fortran_FLAGS}" "-real-size" has_real_size)
+
+    if(has_r8 EQUAL -1 AND has_real_size EQUAL -1)
+        # Add Intel-specific flags for real/integer kinds if not already present
+        set(CVMIX_EXTRA_FLAGS "${CMAKE_Fortran_FLAGS} -r8 -i4")
+        list(APPEND CVMIX_CMAKE_ARGS
+            "-DCMAKE_Fortran_FLAGS=${CVMIX_EXTRA_FLAGS}"
+        )
+        message(STATUS "CVMix (Intel): Adding -r8 -i4 flags for real/integer kind compatibility")
+    endif()
+endif()
+
+# GNU compiler: Ensure critical real/double kind flags are passed
+# FESOM2 uses -fdefault-real-8 -fdefault-double-8 for GNU
+if(CMAKE_Fortran_COMPILER_ID MATCHES "GNU")
+    string(FIND "${CMAKE_Fortran_FLAGS}" "-fdefault-real-8" has_real8)
+
+    if(has_real8 EQUAL -1)
+        # Add GNU-specific flags for real/double kinds if not already present
+        set(CVMIX_EXTRA_FLAGS "${CMAKE_Fortran_FLAGS} -fdefault-real-8 -fdefault-double-8")
+        list(APPEND CVMIX_CMAKE_ARGS
+            "-DCMAKE_Fortran_FLAGS=${CVMIX_EXTRA_FLAGS}"
+        )
+        message(STATUS "CVMix (GNU): Adding -fdefault-real-8 -fdefault-double-8 flags for kind compatibility")
+    endif()
+endif()
+
+# Cray compiler: Ensure critical real kind flags are passed
+# FESOM2 uses -s real64 for Cray
+if(CMAKE_Fortran_COMPILER_ID MATCHES "Cray")
+    string(FIND "${CMAKE_Fortran_FLAGS}" "-s real64" has_real64)
+
+    if(has_real64 EQUAL -1)
+        set(CVMIX_EXTRA_FLAGS "${CMAKE_Fortran_FLAGS} -s real64")
+        list(APPEND CVMIX_CMAKE_ARGS
+            "-DCMAKE_Fortran_FLAGS=${CVMIX_EXTRA_FLAGS}"
+        )
+        message(STATUS "CVMix (Cray): Adding -s real64 flag for real kind compatibility")
+    endif()
+endif()
+
+# NVIDIA/PGI compiler: Ensure critical real kind flags are passed
+if(CMAKE_Fortran_COMPILER_ID MATCHES "NVHPC|PGI")
+    string(FIND "${CMAKE_Fortran_FLAGS}" "-r8" has_r8)
+
+    if(has_r8 EQUAL -1)
+        set(CVMIX_EXTRA_FLAGS "${CMAKE_Fortran_FLAGS} -r8")
+        list(APPEND CVMIX_CMAKE_ARGS
+            "-DCMAKE_Fortran_FLAGS=${CVMIX_EXTRA_FLAGS}"
+        )
+        message(STATUS "CVMix (NVHPC): Adding -r8 flag for real kind compatibility")
+    endif()
+endif()
+
+# Build CVMix library using ExternalProject
+ExternalProject_Add(cvmix-build
+    GIT_REPOSITORY ${CVMIX_GIT_REPOSITORY}
+    GIT_TAG ${CVMIX_GIT_TAG}
+    GIT_SHALLOW TRUE
+    PREFIX ${CMAKE_BINARY_DIR}/external/cvmix-src
+    CMAKE_ARGS ${CVMIX_CMAKE_ARGS}
+    CMAKE_CACHE_ARGS
+        -DCMAKE_Fortran_COMPILER:FILEPATH=${CMAKE_Fortran_COMPILER}
+        -DCMAKE_C_COMPILER:FILEPATH=${CMAKE_C_COMPILER}
+        -DCMAKE_CXX_COMPILER:FILEPATH=${CMAKE_CXX_COMPILER}
+    BUILD_ALWAYS OFF
+    UPDATE_DISCONNECTED TRUE
+    INSTALL_COMMAND ${CMAKE_COMMAND} --build . --target install
+    LOG_DOWNLOAD OFF
+    LOG_CONFIGURE OFF
+    LOG_BUILD OFF
+    LOG_INSTALL OFF
+    USES_TERMINAL_DOWNLOAD ON
+    USES_TERMINAL_CONFIGURE ON
+    USES_TERMINAL_BUILD ON
+    USES_TERMINAL_INSTALL ON
+    STEP_TARGETS configure build install
+)
+
+# Create proper imported target for the built CVMix library
+# This ensures proper dependency propagation
+add_library(CVMix::cvmix STATIC IMPORTED GLOBAL)
+set_target_properties(CVMix::cvmix PROPERTIES
+    IMPORTED_LOCATION ${CVMIX_INSTALL_PREFIX}/lib/libcvmix.a
+    INTERFACE_INCLUDE_DIRECTORIES ${CVMIX_INSTALL_PREFIX}/include/cvmix
+)
+add_dependencies(CVMix::cvmix cvmix-build)
+
+# Set the CVMix variables that will be used by src/CMakeLists.txt
+set(CVMIX_FOUND TRUE CACHE BOOL "CVMix library found" FORCE)
+set(CVMIX_ROOT ${CVMIX_INSTALL_PREFIX} CACHE PATH "CVMix installation root" FORCE)
+set(CVMIX_LIBRARY CVMix::cvmix CACHE STRING "CVMix library target" FORCE)
+set(CVMIX_INCLUDE_DIR ${CVMIX_INSTALL_PREFIX}/include/cvmix CACHE PATH "CVMix include directory" FORCE)
+
+# Create progress monitoring targets
+add_custom_target(cvmix-progress
+    COMMAND ${CMAKE_COMMAND} -E echo "=== Starting CVMix build ==="
+    COMMAND ${CMAKE_COMMAND} -E echo "    Repository: ${CVMIX_GIT_REPOSITORY}"
+    COMMAND ${CMAKE_COMMAND} -E echo "    Version: ${CVMIX_GIT_TAG}"
+    COMMAND ${CMAKE_COMMAND} -E echo "    Compiler: ${CMAKE_Fortran_COMPILER_ID} ${CMAKE_Fortran_COMPILER}"
+    COMMAND ${CMAKE_COMMAND} -E echo "    Build type: ${CMAKE_BUILD_TYPE}"
+    COMMAND ${CMAKE_COMMAND} -E echo "    Installing to: ${CVMIX_INSTALL_PREFIX}"
+    VERBATIM
+)
+
+add_dependencies(cvmix-build-configure cvmix-progress)
+
+# Create a convenience target
+add_custom_target(build_cvmix DEPENDS cvmix-build)
+
+# Add completion message
+add_custom_target(cvmix-complete
+    COMMAND ${CMAKE_COMMAND} -E echo "=== CVMix build complete! ==="
+    COMMAND ${CMAKE_COMMAND} -E echo "    Library: ${CVMIX_INSTALL_PREFIX}/lib/libcvmix.a"
+    COMMAND ${CMAKE_COMMAND} -E echo "    Modules: ${CVMIX_INSTALL_PREFIX}/include/"
+    VERBATIM
+)
+add_dependencies(cvmix-complete cvmix-build)
+add_dependencies(build_cvmix cvmix-complete)
+
+message(STATUS "CVMix will be built from source using ExternalProject")
+message(STATUS "  Version: ${CVMIX_GIT_TAG}")
+message(STATUS "  Installation prefix: ${CVMIX_INSTALL_PREFIX}")
+message(STATUS "  Fortran compiler: ${CMAKE_Fortran_COMPILER_ID}")
+message(STATUS "  Build type: ${CMAKE_BUILD_TYPE}")
+if(CMAKE_Fortran_FLAGS)
+    message(STATUS "  Fortran flags: ${CMAKE_Fortran_FLAGS}")
+endif()

src/CMakeLists.txt

@@ -196,65 +196,36 @@ target_include_directories(${PROJECT_NAME} PUBLIC $<BUILD_INTERFACE:${CMAKE_Fort
 target_include_directories(${PROJECT_NAME} PUBLIC $<INSTALL_INTERFACE:module/fesom>)
 target_link_libraries(${PROJECT_NAME} PRIVATE MPI::MPI_Fortran)
 
-# build CVMix library if CVMIX is ON
-if (CVMIX)
+# Build and link CVMix library if CVMIX option is enabled
+# CVMix is built here in src/ so it can use the same compiler flags as fesom target
+if(CVMIX)
    message(STATUS "CVMIX: ${CVMIX}")
-
-   # read CVMix install and src directories from the download script, so that there
-   # is only one place where they are defined
-   execute_process(COMMAND bash ${src_home}/cvmix_driver/download_cvmix.sh --print-src_dir
-                   OUTPUT_VARIABLE CVMIX_DIR_src OUTPUT_STRIP_TRAILING_WHITESPACE)
-   execute_process(COMMAND bash ${src_home}/cvmix_driver/download_cvmix.sh --print-prefix
-                   OUTPUT_VARIABLE CVMIX_DIR_install OUTPUT_STRIP_TRAILING_WHITESPACE)  
-
-   # set default CVMix installation path
-   set(CVMIX_ROOT "${src_home}/cvmix_driver/${CVMIX_DIR_install}_${CMAKE_Fortran_COMPILER_ID}") 
-   message(STATUS "set default CVMIX_ROOT=${CVMIX_ROOT}")
-
-   # Where library is located --> fix in download_cvmix.sh that it as always installed 
-   # in /lib and not in /lib64
-   set(CVMIX_LIB "${CVMIX_ROOT}/lib/libcvmix.a")
-
-   # Create parent directory early so CMake does not fail on missing include paths
-   file(MAKE_DIRECTORY ${CVMIX_ROOT})
-   file(MAKE_DIRECTORY ${CVMIX_ROOT}/include/cvmix)
-
-   # Collect CVMix source files so that CMake knows what changes triggers a 
-   # possible rebuild of the CVMix library
-   file(GLOB_RECURSE CVMIX_SOURCES
-         "${src_home}/cvmix_driver/${CVMIX_DIR_src}/src/*.F90"
-         "${src_home}/cvmix_driver/${CVMIX_DIR_src}/src/*/*.F90")
-
-   # Add script dependency (rebuild if script changes)
-   set(CVMIX_DOWNLOAD "${src_home}/cvmix_driver/download_cvmix.sh")
-
-   # Custom command: build CVMix if not yet built
-   add_custom_command(
-         OUTPUT ${CVMIX_LIB}
-         COMMAND bash ${src_home}/cvmix_driver/download_cvmix.sh --prefix ${CVMIX_ROOT}
-         WORKING_DIRECTORY ${src_home}/cvmix_driver
-         DEPENDS ${CVMIX_SOURCES} ${CVMIX_DOWNLOAD} # trigger rebuild if source or download script change
-         COMMENT "Downloading and building CVMix into ${CVMIX_ROOT}"
-         VERBATIM)
-
-   # check if ${CVMIX_ROOT}/lib/libcvmix.a exist or not, only if it does not 
-   # exist build library
-   add_custom_target(cvmix_autobuild DEPENDS ${CVMIX_LIB})
-
-   # build cvmix external libray
-   add_library(cvmix_external STATIC IMPORTED GLOBAL)
-   set_target_properties(cvmix_external PROPERTIES
-         IMPORTED_LOCATION ${CVMIX_LIB}
-         INTERFACE_INCLUDE_DIRECTORIES "${CVMIX_ROOT}/include/cvmix")
-
-   # cvmix_autobuild is a custom target that runs your download_cvmix.sh script 
-   # and produces libcvmix.a. cvmix_external is an imported library, meaning CMake 
-   # doesn’t build it — it just points to an existing file (libcvmix.a).
-   add_dependencies(cvmix_external  cvmix_autobuild)
-
-   # Link CVMix library to fesom, build chain becomes: fesom → cvmix_external → cvmix_autobuild
-   target_link_libraries(${PROJECT_NAME} PRIVATE cvmix_external)
-
+
+   # Build CVMix using ExternalProject with same flags as fesom
+   include(ExternalProject)
+   include(${CMAKE_CURRENT_LIST_DIR}/../cmake/BuildCVMix.cmake)
+
+   # CVMix variables are set by BuildCVMix.cmake
+   # CVMIX_LIBRARY contains the imported target CVMix::cvmix
+   # CVMIX_INCLUDE_DIR contains the module directory
+
+   if(NOT TARGET CVMix::cvmix)
+      message(FATAL_ERROR "CVMix target not found. BuildCVMix.cmake should have created it.")
+   endif()
+
+   # Add CVMix module directory to include path
+   # This allows FESOM2's cvmix_driver wrapper files to find CVMix modules
+   target_include_directories(${PROJECT_NAME} PRIVATE ${CVMIX_INCLUDE_DIR})
+
+   # Link CVMix library to fesom
+   target_link_libraries(${PROJECT_NAME} PRIVATE CVMix::cvmix)
+
+   # Ensure CVMix is built before fesom
+   add_dependencies(${PROJECT_NAME} cvmix-build)
+
+   message(STATUS "CVMix library target: ${CVMIX_LIBRARY}")
+   message(STATUS "CVMix include directory: ${CVMIX_INCLUDE_DIR}")
+
 endif()
 
 set_target_properties(${PROJECT_NAME} PROPERTIES LINKER_LANGUAGE Fortran)