refactor(cmake): split CMakeLists into modules (#1587)

cmake/targets/common.cmake

@@ -0,0 +1,35 @@
+# common target definitions
+# this file will also load platform specific macros
+
+add_executable(sunshine ${SUNSHINE_TARGET_FILES})
+
+# platform specific target definitions
+if(WIN32)
+    include(${CMAKE_MODULE_PATH}/targets/windows.cmake)
+elseif(UNIX)
+    include(${CMAKE_MODULE_PATH}/targets/unix.cmake)
+
+    if(APPLE)
+        include(${CMAKE_MODULE_PATH}/targets/macos.cmake)
+    else()
+        include(${CMAKE_MODULE_PATH}/targets/linux.cmake)
+    endif()
+endif()
+
+# todo - is this necessary? ... for anything except linux?
+if(NOT DEFINED CMAKE_CUDA_STANDARD)
+    set(CMAKE_CUDA_STANDARD 17)
+    set(CMAKE_CUDA_STANDARD_REQUIRED ON)
+endif()
+
+target_link_libraries(sunshine ${SUNSHINE_EXTERNAL_LIBRARIES} ${EXTRA_LIBS})
+target_compile_definitions(sunshine PUBLIC ${SUNSHINE_DEFINITIONS})
+set_target_properties(sunshine PROPERTIES CXX_STANDARD 17
+        VERSION ${PROJECT_VERSION}
+        SOVERSION ${PROJECT_VERSION_MAJOR})
+
+foreach(flag IN LISTS SUNSHINE_COMPILE_OPTIONS)
+    list(APPEND SUNSHINE_COMPILE_OPTIONS_CUDA "$<$<COMPILE_LANGUAGE:CUDA>:--compiler-options=${flag}>")
+endforeach()
+
+target_compile_options(sunshine PRIVATE $<$<COMPILE_LANGUAGE:CXX>:${SUNSHINE_COMPILE_OPTIONS}>;$<$<COMPILE_LANGUAGE:CUDA>:${SUNSHINE_COMPILE_OPTIONS_CUDA};-std=c++17>)  # cmake-lint: disable=C0301