8.2 Defining New Object Attributes
If you want to define a new gnu object attribute, here are the places you
will need to modify.  New attributes should be discussed on the binutils
mailing list.
     
- This manual, which is the official register of attributes. 
 - The header for your architecture include/elf, to define the tag. 
 - The bfd support file for your architecture, to merge the attribute
and issue any appropriate link warnings. 
 - Test cases in ld/testsuite for merging and link warnings. 
 - binutils/readelf.c to display your attribute. 
 - GCC, if you want the compiler to mark the attribute automatically.