[Bug lto/49992] lto-bootstrap reveals duplicate symbols on x86_64-apple-darwin11

["iains at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49992

--- Comment #28 from Iain Sandoe <iains at gcc dot gnu.org> 2011-08-09 17:41:25 UTC ---
(In reply to comment #27)
> So, the fix is trivial but you guys are wondering in the weeds.  Make the
> symbols unique and be done with it, that, or remove one of them.  You are
> getting hung up on darwin -c stuff, ignore that, that's not the bug, even if
> bugs do exist in that area.

well, the fix @comment 6 does that - but, in this instance, it's not a complete
solution.

basically, on darwin >= 10 the presence of the ___gnu_lto_v1 causes the first
item in a library to be loaded - this does not occur on darwin 9 (regardless of
whether ___gnu_lto_v1 is listed in the archive toc).

so, it's a "regression" or at least an alteration in the behavior of ld.

whilst we have wandered around a bit - that was because there are two issues:

1. duplicate implementations of the diagnostics (comment 6 should fix)

2. random issues caused by archive members being loaded when ___gnu_lto_v1 is
present in the toc.

my question is about whether there is a reason to include ___gnu_lto_v1 in the
toc on Darwin (i.e. why was the -c added - the ChangeLog doesn't identify a PR
or reason other than  to make it like other ranlibs).