ARM: the keil still include unused functions

Hi: i try use keil version 5 build a project, like flash algorithm, a set of functions run in RAM, control by SWD, provide access SoC peripheral. it will use STM32 cube, and it build as lib, set "One ELF Section per Function", "Read-Only Position Independent","Read-Write Position Independent" in C/C++ table, "Make RW Sections Position Independent" , "Make RO Sections Position Independent"