Generate .map file.

[Cierpliwy]

Add an option to the main target to generate .map file for the project.

[gudnimg]

I do it like this in my project:

I am using CMake 3.19.4 and cannot guarantee this will work back to CMake 3.14.

function(nrf5_target target)
    # .... some code above
        # Generate linker map file
        target_linker_map(${target})
    # .... some code below
endfunction()

function(target_linker_map target)
    set(GEN_MAP_FILE "-Wl,-Map,")
    get_target_property(map_dir ${target} BINARY_DIR) # Read which folder target is defined
    target_link_options(${target} PRIVATE ${GEN_MAP_FILE}${map_dir}/${target}.map) # place .map file is same folder as target

    # allow ninja clean command to remove file
    set_target_properties(${target} PROPERTIES
        ADDITIONAL_CLEAN_FILES ${target}.map)
endfunction()