From the top of elf32_arm_merge_eabi_attributes:
if (!elf_known_obj_attributes_proc (obfd)[0].i)
{
/* This is the first object. Copy the attributes. */
_bfd_elf_copy_obj_attributes (ibfd, obfd);
/* Use the Tag_null value to indicate the attributes have been
initialized. */
elf_known_obj_attributes_proc (obfd)[0].i = 1;
return TRUE;
}
This means that we don't warn about unknown attributes if they're in
the very first file, and if every file has the unknown attribute with
the same value - or does not have it at all - then the output file
will include it. But if the first file doesn't have it and a later
file does, it'll be warned about and dropped.
Do we need to run through the full merging process for the first
file too?