https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66523
Iain Sandoe <iains at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2015-07-07
Ever confirmed|0 |1
--- Comment #8 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Iain Sandoe from comment #7)
> (In reply to m...@gcc.gnu.org from comment #6)
> > Another proposal, any symbol with an 'L.*' spelling should be not so marked,
> > as these can never be used this way. Seems like we should have a predicate
> > to call before marking something as no dead strip and it should get rid of
> > all of them, including L.* symbols.
>
> that's pretty much what my comment says - however, what I want to check
> (when I get a spare ns) is whether ObjC should be emitting "l_xxx" symbols
> for these (i.e. linker-only-visible, but not preserved). If someone else
> has time to look before me, then fine :)
So, I had a look at what Apple gcc-4.2.1 and current TOT clang produce.
gcc-4.2.1 is silent about preservation.
clang puts the relevant stuff into sections marked as "no_dead_strip" (but
doesn't mark the individual symbols).
For LTO to work we need to mark these items as non-strippable, because that
happens in a way that won't see that the containing section is "no_dead_strip".
Thus, for now, I think that the patch I have in my Q is OK.
(as a follow-on, I think to revise the section headers to ensure that they
contain "no_dead_strip", but that needs to be checked to be compatible with the
range of ld64 variants we use).
The current patch does what Mike has suggested above - rejects symbols starting
with L* as no_dead_strip.
Any other opinions (or shall I post/apply the patch)?
