fix nanopb_generate

components/nanopb/functions.cmake

@@ -1,19 +1,23 @@
+set(NANOPB_PLUGIN "${CMAKE_CURRENT_LIST_DIR}/nanopb/generator/protoc-gen-nanopb")
+
 function(nanopb_generate PROTO_FILE PB_OUT HDR_VAR SRC_VAR)
     get_filename_component(PROTO_FILE_NAME ${PROTO_FILE} NAME_WE)
     get_filename_component(PROTO_FILE_PATH ${PROTO_FILE} ABSOLUTE BASE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
     get_filename_component(PROTO_FILE_DIR ${PROTO_FILE_PATH} DIRECTORY)
     set(PROTO_HDR "${PB_OUT}/${PROTO_FILE_NAME}.pb.h")
     set(PROTO_SRC "${PB_OUT}/${PROTO_FILE_NAME}.pb.c")
-    list(APPEND "${HDR_VAR}" ${PROTO_HDR})
-    list(APPEND "${SRC_VAR}" ${PROTO_SRC})
+    set(${HDR_VAR} ${${HDR_VAR}} ${PROTO_HDR} PARENT_SCOPE)
+    set(${SRC_VAR} ${${SRC_VAR}} ${PROTO_SRC} PARENT_SCOPE)
     if(NOT CMAKE_SCRIPT_MODE_FILE)
         add_custom_command(OUTPUT ${PROTO_HDR} ${PROTO_SRC} 
             COMMAND protoc 
-                --plugin=protoc-gen-nanopb=${CMAKE_CURRENT_LIST_DIR}/nanopb/generator/protoc-gen-nanopb 
+                --plugin=protoc-gen-nanopb=${NANOPB_PLUGIN}
                 --nanopb_out=${PB_OUT}
                 --proto_path ${PROTO_FILE_DIR}
                 ${PROTO_FILE_PATH}
-            DEPENDS ${PROTO_FILE_PATH})
+            DEPENDS ${PROTO_FILE_PATH}
+            COMMENT "Generating nanopb sources for ${PROTO_FILE}")
+        set_property(SOURCE ${PROTO_HDR} ${PROTO_SRC} PROPERTY GENERATED TRUE)
     endif()
     list(APPEND ADDITIONAL_MAKE_CLEAN_FILES ${PROTO_HDR} ${PROTO_SRC})
 endfunction()