Re: libcc_s.so and libc.so curcular dependency on FreeBSD

[Richard Henderson <rth at redhat dot com>]

On Mon, Apr 02, 2007 at 10:54:12PM -0400, Alexander Kabaev wrote:
> This creates a dependency cycle that I need to break. The simplest way
> to go appears to follow Linux's lead and eliminate the need for shared
> modules to have explicit frame into registration calls at startup and
> allow exception handling code to locate necessary info with the help of
> dynamic loader using dl_iterate_phdr call.

Yes, this is absolutely the best option, for a number of reasons.
I wish more of the free operating systems would use this method.

> I also noticed that on Linux glibc implements some of the libgcc
> symbols, namely _Unwind_Find_FDE and __register_frame_info_bases family
> of functions. I wonder why it is done and if I missed something obvious
> here.

Someone incorporated these functions into Linux libc.so quite a long
time ago, trying to solve the same problem that eventually led us to
create the shared libgcc.  Unfortunately, this leads to a binary 
compatibility problem when trying to remove them, so now they're
mostly stubs that defer to the libgcc implementation.


r~