CMakeLists.txt: configure and install cmake config file

* GFDLGTracersConfig.cmake.in: use find_dependency instead of find_package
See https://cmake.org/cmake/help/latest/module/CMakeFindDependencyMacro.html

Author: dougiesquire

CMakeLists.txt

@@ -10,6 +10,7 @@ project(GFDLGTracers
 )
 
 include(GNUInstallDirs)
+include(CMakePackageConfigHelpers)
 
 if(NOT CMAKE_BUILD_TYPE MATCHES "^(Debug|Release|RelWithDebInfo|MinSizeRel)$")
   message(STATUS "Setting build type to 'Relwithdebinfo' as none was specified.")
@@ -115,6 +116,16 @@ install(EXPORT GFDLGTracersTargets
   DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/GFDLGTracers
 )
 
+configure_package_config_file(
+  cmake/GFDLGTracersConfig.cmake.in
+  "${CMAKE_CURRENT_BINARY_DIR}/GFDLGTracersConfig.cmake"
+  INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/GFDLGTracers
+)
+
+install(FILES ${CMAKE_CURRENT_BINARY_DIR}/GFDLGTracersConfig.cmake
+  DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/GFDLGTracers
+)
+
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/GFDLGTracers.pc.in
                ${CMAKE_CURRENT_BINARY_DIR}/GFDLGTracers.pc @ONLY)
 

cmake/GFDLGTracersConfig.cmake.in

@@ -0,0 +1,25 @@
+# Copyright ACCESS-NRI and contributors. See the top-level LICENSE file for details.
+
+@PACKAGE_INIT@
+
+if(NOT GFDLGTracers_FIND_QUIETLY)
+  message(STATUS "Found GFDLGTracers: ${PACKAGE_PREFIX_DIR}")
+endif()
+
+include(CMakeFindDependencyMacro)
+
+# Request components
+set(_required_components ${GFDLGTracers_FIND_COMPONENTS})
+
+find_dependency(MPI REQUIRED COMPONENTS Fortran)
+find_dependency(fms COMPONENTS R8 REQUIRED)
+find_dependency(PkgConfig REQUIRED)
+pkg_check_modules(MOCSY REQUIRED IMPORTED_TARGET "mocsy")
+
+# Run the normal Targets.cmake
+list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR})
+include("${CMAKE_CURRENT_LIST_DIR}/GFDLGTracersTargets.cmake")
+list(REMOVE_ITEM CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR})
+
+# Check the requested components are valid
+check_required_components(_required_components)