#source: undef.s
#ld: -r
#readelf: -s

Symbol table '.symtab' contains .* entries:
 +Num: +Value +Size Type +Bind +Vis +Ndx +Name
#...
 +[0-9]+: [0-9a-fA-F]* +0 +NOTYPE +GLOBAL +PROTECTED +UND protected
#pass