Re: libgcc_s, Linux, and PT_GNU_EH_FRAME, and binutils

[martin at v dot loewis dot de (Martin v. Loewis)]

Mark Mitchell <mark@codesourcery.com> writes:

> OK; I understand the technical issue.  I should have been more clear;
> how will the "both of them in wide use" part happen?
> 
> The whole point of 3.2 is for all the distributors to have a chance to
> get to a common ABI.  I'd assume they will be able to get together and
> agree on the right set of configure options.  

They certainly will. However, Linux users will build their own gcc 3
installations for existing Linux installations. Those won't be
compatible with what the distributors include in their next
distributions. I believe that there will be many such installations.

> People building their own GCC -- rather than getting stuff from a
> GNU/Linux distributor -- are going to have a harder time.  But, they're
> doing things the hard way; I don't mind that.

My concern is that they don't get an error indication except for the
crash, and it will be often very difficult to analyse what kind of
libgcc_s was in use.

This is especially unfortunate since the problem can be fixed in gcc:
- gcc could make those two ABIs compatible (by deciding at run-time
  whether to invoke __register_frame_info_bases), or
- gcc could you symbol versioning, to make the two versions of libgcc_s
  distinguishable, or
- gcc could refuse to build itself unless that is overridden by the
  user.

Regards,
Martin