Tool to analyze size of ELF sections and symbol

You can use nm and size to get the size of functions and ELF sections.

To get the size of the functions (and objects with static storage duration):

$ nm --print-size --size-sort --radix=d tst.o

The second column shows the size in decimal of function and objects.

To get the size of the sections:

$ size -A -d tst.o

The second column shows the size in decimal of the sections.

The readelf utility is handy for displaying a variety of section information, including section sizes, e.g.:

arm-none-eabi-readelf -e foo.o

If you're interested in the run-time memory footprint, you can ignore the sections that do not have the 'A' (allocate) flag set.