add function stm32_print_size_of_target

cmake/stm32/common.cmake

@@ -42,6 +42,12 @@ find_program(CMAKE_SIZE NAMES ${STM32_TARGET_TRIPLET}-size PATHS ${TOOLCHAIN_BIN
 find_program(CMAKE_DEBUGGER NAMES ${STM32_TARGET_TRIPLET}-gdb PATHS ${TOOLCHAIN_BIN_PATH} NO_DEFAULT_PATH)
 find_program(CMAKE_CPPFILT NAMES ${STM32_TARGET_TRIPLET}-c++filt PATHS ${TOOLCHAIN_BIN_PATH} NO_DEFAULT_PATH)
 
+FUNCTION(stm32_print_size_of_target TARGET)
+    # this target is always considered out of date so size will always be displayed on build
+    ADD_CUSTOM_TARGET(${TARGET}_size ALL COMMAND ${CMAKE_SIZE} ${TARGET}${CMAKE_EXECUTABLE_SUFFIX_C}
+                                                        DEPENDS ${TARGET}${CMAKE_EXECUTABLE_SUFFIX_C})
+ENDFUNCTION()
+
 function(stm32_get_chip_type FAMILY DEVICE TYPE)
     set(INDEX 0)
     foreach(C_TYPE ${STM32_${FAMILY}_TYPES})