examples use externalproject

Author: scivision

Examples/CMakeLists.txt

@@ -1,13 +1,18 @@
 cmake_minimum_required(VERSION 3.19...3.22)
 
 project(nc4fortranExample
-LANGUAGES Fortran
+LANGUAGES C Fortran
 )
 
 include(CTest)
 
+if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
+  set(CMAKE_INSTALL_PREFIX ${CMAKE_BINARY_DIR} CACHE PATH "Install top-level directory" FORCE)
+endif()
 
-find_package(nc4fortran CONFIG REQUIRED)
+list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/../cmake/Modules)
+
+include(${PROJECT_SOURCE_DIR}/../cmake/nc4fortran.cmake)
 
 # --- Fortran interface for examples
 add_library(fortran_interface fortran_interface.f90)

cmake/nc4fortran.cmake

@@ -0,0 +1,60 @@
+include(ExternalProject)
+
+if(NOT nc4fortran_external)
+  find_package(nc4fortran CONFIG)
+
+  if(nc4fortran_FOUND)
+    message(STATUS: "nc4fortran found: ${nc4fortran_DIR}")
+    return()
+  endif()
+endif()
+
+set(nc4fortran_external true CACHE BOOL "Build nc4fortran")
+
+find_package(NetCDF REQUIRED COMPONENTS Fortran)
+
+if(NOT nc4fortran_ROOT)
+  set(nc4fortran_ROOT ${CMAKE_INSTALL_PREFIX})
+endif()
+
+set(nc4fortran_INCLUDE_DIRS ${nc4fortran_ROOT}/include)
+
+if(BUILD_SHARED_LIBS)
+  set(nc4fortran_LIBRARIES ${nc4fortran_ROOT}/lib/${CMAKE_SHARED_LIBRARY_PREFIX}nc4fortran${CMAKE_SHARED_LIBRARY_SUFFIX})
+else()
+  set(nc4fortran_LIBRARIES ${nc4fortran_ROOT}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}nc4fortran${CMAKE_STATIC_LIBRARY_SUFFIX})
+endif()
+
+set(nc4fortran_cmake_args
+-DCMAKE_INSTALL_PREFIX=${nc4fortran_ROOT}
+-DBUILD_SHARED_LIBS:BOOL=${BUILD_SHARED_LIBS}
+-DCMAKE_BUILD_TYPE=Release
+-DBUILD_TESTING:BOOL=false
+-Dautobuild:BOOL=false
+-DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
+-DCMAKE_Fortran_COMPILER=${CMAKE_Fortran_COMPILER}
+)
+
+ExternalProject_Add(NC4FORTRAN
+SOURCE_DIR ${CMAKE_CURRENT_LIST_DIR}/..
+CMAKE_ARGS ${nc4fortran_cmake_args}
+CMAKE_GENERATOR ${EXTPROJ_GENERATOR}
+BUILD_BYPRODUCTS ${nc4fortran_LIBRARIES}
+INACTIVITY_TIMEOUT 15
+CONFIGURE_HANDLED_BY_BUILD ON
+)
+
+file(MAKE_DIRECTORY ${nc4fortran_INCLUDE_DIRS})
+
+if(BUILD_SHARED_LIBS)
+  add_library(nc4fortran::nc4fortran SHARED IMPORTED)
+else()
+  add_library(nc4fortran::nc4fortran STATIC IMPORTED)
+endif()
+
+set_target_properties(nc4fortran::nc4fortran PROPERTIES IMPORTED_LOCATION ${nc4fortran_LIBRARIES})
+target_include_directories(nc4fortran::nc4fortran INTERFACE ${nc4fortran_INCLUDE_DIRS})
+target_link_libraries(nc4fortran::nc4fortran INTERFACE NetCDF::NetCDF_Fortran)
+
+# race condition for linking without this
+add_dependencies(nc4fortran::nc4fortran NC4FORTRAN)