Without looking at the actual final linked image to see everything and
what is linked in you are dancing in the dark.
Previously you said you did this, but now it sounds like you haven't.
The gcc tool set comes with a set of binutils. There is a tool "objdump" to look at .elf files
The avr-gcc tool package that comes with the IDE comes with the gcc binutils.
In that package, objdump is called "avr-objdump"
I recommend using that with the -S and -h options.
--- bill