[Bug target/48108] lto should be containerized in a single mach-o section on darwin

["howarth at nitro dot med.uc.edu" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48108

--- Comment #17 from Jack Howarth <howarth at nitro dot med.uc.edu> 2011-08-05 18:52:05 UTC ---
(In reply to comment #12)
> (In reply to comment #11)
> > Created attachment 24397 [details]
> > Iain's work in progress for LTO containerization
> 
> Sorry that I can't commit any time to GCC right now.
> 
> The main outstanding issue with this patch is that the intermediate files
> created by GCC are still unbounded in the number of sections. 
> 
> So long as the only consumer of those files is GCC, no problem (since the
> arrangement has been made to ensure that relocatable sections come first).
> 
> However, those intermediate files are still technically 'wrong' and therefore
> the writer should be updated to do the same encapsulation.  Once that is done
> there will be no need to retain the ability to recognize GCC vs 'normal'
> objects.

Should we really be so hung up on the intermediate file issue? After all, why
would anyone try to use object files generated with -flto with a compiler that
doesn't support -flto. I would argue that this prevents users from accidentally
disabling the -flto in that case (where they erroneously use a non-LTO aware
compiler). This could simply be marked as a TODO.