CMakeLists.txt

cmake_minimum_required (VERSION 3.14)

if (NOT DEFINED PROJECT_NAME)
  set(CPRNC_STANDALONE TRUE)
endif()

project (cprnc Fortran C)
include (CheckFunctionExists)
include (ExternalProject)

#===== Local modules =====
list (APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake)

#==============================================================================
#  DEFINE THE TARGET
#==============================================================================

set (CPRNC_Fortran_SRCS cprnc.F90  filestruct.F90  prec.F90  utils.F90)

set (CPRNC_GenF90_SRCS compare_vars_mod.F90)


set (CPRNC_Fortran_MODS ${CMAKE_CURRENT_BINARY_DIR}/compare_vars_mod.mod
                        ${CMAKE_CURRENT_BINARY_DIR}/filestruct.mod
                        ${CMAKE_CURRENT_BINARY_DIR}/prec.mod)

set(CMAKE_POSITION_INDEPENDENT_CODE ON)

# Compiler-specific compile options
if ("${CMAKE_Fortran_COMPILER_ID}" STREQUAL "GNU")
  set (CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -ffree-line-length-none")
endif()

if (CMAKE_BUILD_TYPE STREQUAL "DEBUG")
  set (CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -O0 -g")
endif()

#==============================================================================
#  DEFINE THE DEPENDENCIES
#==============================================================================

#===== genf90 =====
if (DEFINED GENF90_PATH)
  # If GENF90_PATH is defined, the target may also already be defined
  if (NOT TARGET genf90)
    add_custom_target(genf90
      DEPENDS ${GENF90_PATH}/genf90.pl)
  endif()
else ()
  ExternalProject_Add (genf90
    PREFIX ${CMAKE_CURRENT_BINARY_DIR}/genf90
    GIT_REPOSITORY https://github.com/PARALLELIO/genf90
    GIT_TAG genf90_200608
    UPDATE_COMMAND ""
    CONFIGURE_COMMAND ""
    BUILD_COMMAND ""
    INSTALL_COMMAND "")
  ExternalProject_Get_Property (genf90 SOURCE_DIR)
  set (GENF90_PATH ${SOURCE_DIR})
  unset (SOURCE_DIR)
endif ()


file(COPY  ${CMAKE_CURRENT_SOURCE_DIR}/run_tests
     DESTINATION ${CMAKE_CURRENT_BINARY_DIR})

execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${CMAKE_CURRENT_SOURCE_DIR}/test_inputs ${CMAKE_CURRENT_BINARY_DIR}/test_inputs)

#===== Fortran Source Generation with GenF90 =====
foreach (SRC_FILE IN LISTS CPRNC_GenF90_SRCS)
  add_custom_command (OUTPUT ${SRC_FILE}
    COMMAND ${GENF90_PATH}/genf90.pl
    ${CMAKE_CURRENT_SOURCE_DIR}/${SRC_FILE}.in > ${SRC_FILE}
    DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/${SRC_FILE}.in genf90)
endforeach ()

# Try to find NetCDF dependency. Try standard find_package first.
find_package(NetCDF QUIET COMPONENTS C Fortran)
if (NetCDF_C_FOUND AND NetCDF_Fortran_FOUND)
  if(TARGET NetCDF::NetCDF_Fortran)
    set(CPRNC_NETCDF_FORTRAN_LIB NetCDF::NetCDF_Fortran)
    set(CPRNC_NETCDF_C_LIB       NetCDF::NetCDF_C)
  else()
    # We used an old-school find netcdf module. Make the target here
    add_library(netcdf_cprnc INTERFACE)
    target_link_libraries(netcdf_cprnc INTERFACE ${NetCDF_Fortran_LIBRARIES};${NetCDF_C_LIBRARIES})
    target_include_directories(netcdf_cprnc INTERFACE ${NetCDF_Fortran_INCLUDE_DIRS};${NetCDF_C_INCLUDE_DIRS})
    set(CPRNC_NETCDF_FORTRAN_LIB netcdf_cprnc)
  endif()
else ()
  # If netcdf is not installed as a CMake pkg, the find_package above will fail,
  # but netcdf may still be installed in the <PackageName>_ROOT folders
  find_library(NetCDF_C_LIBRARIES netcdf HINTS ${NetCDF_C_ROOT} PATH_SUFFIXES lib lib64)
  find_library(NetCDF_Fortran_LIBRARIES netcdff HINTS ${NetCDF_Fortran_ROOT} PATH_SUFFIXES lib lib64)
  find_path(NetCDF_C_INCLUDE_DIRS netcdf.h HINTS ${NetCDF_C_ROOT} PATH_SUFFIXES include)
  find_path(NetCDF_Fortran_INCLUDE_DIRS netcdf.mod HINTS ${NetCDF_Fortran_ROOT} PATH_SUFFIXES include)

  if (NetCDF_C_LIBRARIES AND NetCDF_Fortran_LIBRARIES AND
      NetCDF_C_INCLUDE_DIRS AND NetCDF_Fortran_INCLUDE_DIRS)
    add_library(netcdf_cprnc INTERFACE)
    target_link_libraries(netcdf_cprnc INTERFACE ${NetCDF_Fortran_LIBRARIES};${NetCDF_C_LIBRARIES})
    target_include_directories(netcdf_cprnc INTERFACE ${NetCDF_Fortran_INCLUDE_DIRS};${NetCDF_C_INCLUDE_DIRS})
    set(CPRNC_NETCDF_FORTRAN_LIB netcdf_cprnc)
  else()
    message(STATUS "NetCDF was not found, falling back on pkg-config")
    find_package(PkgConfig REQUIRED)

    #===== NetCDF =====
    pkg_check_modules(NetCDF REQUIRED IMPORTED_TARGET netcdf)

    #===== NetCDF-Fortran =====
    pkg_check_modules(NetCDF_Fortran REQUIRED IMPORTED_TARGET netcdf-fortran)

    set(CPRNC_NETCDF_FORTRAN_LIB PkgConfig::NetCDF_Fortran)
    set(CPRNC_NETCDF_C_LIB       PkgConfig::NetCDF)
  endif()
endif()

add_executable (cprnc ${CPRNC_Fortran_SRCS} ${CPRNC_GenF90_SRCS})
target_include_directories(cprnc PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

add_dependencies (cprnc genf90)

# Always use -fPIC
set_property(TARGET cprnc PROPERTY POSITION_INDEPENDENT_CODE ON)
target_link_libraries (cprnc
    PUBLIC ${CPRNC_NETCDF_FORTRAN_LIB} ${CPRNC_NETCDF_C_LIB})

# We do not want cprnc injecting ctests into parent projects
if (CPRNC_STANDALONE)
  enable_testing()
  add_test(NAME run_tests COMMAND run_tests -outdir tmp)
endif()

#==============================================================================
#  DEFINE THE INSTALL
#==============================================================================

# Executable
install (TARGETS cprnc DESTINATION bin)