[Bug bootstrap/39316] [lto] revision 144454 - Configure should check for elf support (similar to gmp/mpfr/PPL/CLooG)

["zadeck at naturalbridge dot com" <gcc-bugzilla@gcc.gnu.org>]

------- Comment #4 from zadeck at naturalbridge dot com  2009-10-03 23:57 -------
Richard, 

the problem is that at least for the linux world there are two elf
implementations that while they claim to be compatible are distinctly different
on the inside.  LTO, for better or worse, needs to use features that are not
necessarily part of the "standard" elf, for some definition of standard.

unlike gmp and mpfr, where there has always been 1 open source version, elf was
reverse engineered for linux from the sun version at least twice, each with its
own warts.   It has not helped anything that suse and redhat seem to have
chosen to distribute different implementations.   this led to a fair amount of
confusion when mark mitchell and i started working on lto because codesourcery
generally runs redhat and naturalbridge runs suse.  We were always breaking the
code on the others machines.

i think that iant "solved" this problem for gold by just writing his own elf
library rather than relying on what was installed which is what lto does.  
Aside from going down that road, we are most likely screwed because lto needs
stuff out of the mainstream elf.

I hope that this clarifies some of your issues here.

kenny


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39316