makes setup_target function more robust when being called in other CMakeLists.txt files

CMakeLists.txt

@@ -47,22 +47,22 @@ function(setup_target TARGET)
 
   add_executable(${TARGET})
   target_sources(${TARGET} PRIVATE
-    port/picolibc/port.c
+    ${CMAKE_SOURCE_DIR}/port/picolibc/port.c
-    port/moonlight/bootup.c
+    ${CMAKE_SOURCE_DIR}/port/moonlight/bootup.c
-    port/moonlight/board.c
+    ${CMAKE_SOURCE_DIR}/port/moonlight/board.c
-    port/moonlight/trap_non_vectored.c
+    ${CMAKE_SOURCE_DIR}/port/moonlight/trap_non_vectored.c
-    port/moonlight/exception.c
+    ${CMAKE_SOURCE_DIR}/port/moonlight/exception.c
-    port/moonlight/vector_table.c
+    ${CMAKE_SOURCE_DIR}/port/moonlight/vector_table.c
   )
   if("netxduo" IN_LIST ST_LIBRARIES)
-    target_sources(${TARGET} PRIVATE port/moonlight/mnrs_network_driver.c)
+    target_sources(${TARGET} PRIVATE ${CMAKE_SOURCE_DIR}/port/moonlight/mnrs_network_driver.c)
   endif()
 
   if(ST_SOURCES)
     target_sources(${TARGET} PRIVATE ${ST_SOURCES})
   endif()
 
-  target_include_directories(${TARGET} PRIVATE port/moonlight src)
+  target_include_directories(${TARGET} PRIVATE ${CMAKE_SOURCE_DIR}/port/moonlight ${CMAKE_SOURCE_DIR}/src)
   target_compile_options(${TARGET} PRIVATE
     -ffreestanding
     -fno-builtin
@@ -72,7 +72,7 @@ function(setup_target TARGET)
   if(NX_DEBUG)
     target_compile_definitions(${TARGET} PRIVATE NX_DEBUG NX_DEBUG_PACKET)
   endif()
-  target_link_directories(${TARGET} PRIVATE src) # needed for linker script includes
+  target_link_directories(${TARGET} PRIVATE ${CMAKE_SOURCE_DIR}/src) # needed for linker script includes
   target_link_options(${TARGET} PRIVATE
     -nostartfiles
     -nostdlib