Define optional targets as components

Author: tpadioleau

cmake/DDCConfig.cmake.in

@@ -7,9 +7,6 @@
 include(CMakeFindDependencyMacro)
 
 set(DDC_BUILD_DOUBLE_PRECISION @DDC_BUILD_DOUBLE_PRECISION@)
-set(DDC_BUILD_KERNELS_FFT @DDC_BUILD_KERNELS_FFT@)
-set(DDC_BUILD_KERNELS_SPLINES @DDC_BUILD_KERNELS_SPLINES@)
-set(DDC_BUILD_PDI_WRAPPER @DDC_BUILD_PDI_WRAPPER@)
 
 find_package(Kokkos 4.4...4.5)
 
@@ -40,4 +37,10 @@ foreach(target core fft pdi splines)
    endif()
 endforeach()
 
+foreach(target_component fft pdi splines)
+   if(TARGET DDC::impl::ddc_${target_component})
+      set(DDC_${target_component}_FOUND TRUE)
+   endif()
+endforeach()
+
 check_required_components(DDC)

install_test/CMakeLists.txt

@@ -5,13 +5,13 @@
 cmake_minimum_required(VERSION 3.22)
 project(test-installed-ddc LANGUAGES CXX)
 
-find_package(DDC REQUIRED)
+find_package(DDC REQUIRED COMPONENTS fft pdi splines)
 
 message("DDC options:")
 message("DDC_BUILD_DOUBLE_PRECISION=${DDC_BUILD_DOUBLE_PRECISION}")
-message("DDC_BUILD_KERNELS_FFT=${DDC_BUILD_KERNELS_FFT}")
-message("DDC_BUILD_KERNELS_SPLINES=${DDC_BUILD_KERNELS_SPLINES}")
-message("DDC_BUILD_PDI_WRAPPER=${DDC_BUILD_PDI_WRAPPER}")
+message("DDC_fft_FOUND=${DDC_fft_FOUND}")
+message("DDC_splines_FOUND=${DDC_splines_FOUND}")
+message("DDC_pdi_FOUND=${DDC_pdi_FOUND}")
 
 add_executable(main main.cpp)
 target_link_libraries(main PRIVATE DDC::core DDC::fft DDC::pdi DDC::splines)