Alignment of special common variables

[Galit Heller]

Hi,

Our port for NS CR16C defines special common variable sections, in a manner
similar to MIPS's .scommon, using hook functions such as
elf_backend_add_symbol_hook.

We noticed that these special common variables aren't aligned correctly in the
output, and, specifically -with -sort-common, they aren't sorted correctly,
and traced the reason to the following test in elflink.h
function elf_bfd_link_add_symbols:

      /* Set the alignment of a common symbol.  */
      if (isym->st_shndx == SHN_COMMON
          && h->root.type == bfd_link_hash_common)
        {
          unsigned int align;

          align = bfd_log2 (isym->st_value);
          if (align > old_alignment
              /* Permit an alignment power of zero if an alignment of one
                 is specified and no other alignments have been specified.  */
              || (isym->st_value == 1 && old_alignment == 0))
            h->root.u.c.p->alignment_power = align;
          else
            h->root.u.c.p->alignment_power = old_alignment;
        }

Since the section index of these variables is a processor specific section
index, and not SHN_COMMON, the condition isn't true, and thus the special
common variables' alignment isn't set correctly (instead it's set to the
size, by _bfd_generic_link_add_one_symbol).

Has anyone experienced this problem on a platform which supports special
common sections, and has a suggestion how to work around this ?

Regards,
Galit.