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Re: [wiget@pld.org.pl] libc/3237: symbol __udivdi3, version GLIBC_2.0 not defined in file libc.so.6 with link time reference
On Monday 15 April 2002 11:52, Jakub Jelinek wrote:
> On Mon, Apr 15, 2002 at 11:42:52AM +0200, Franz Sirl wrote:
> > With gcc-2.95 this pulls in __umoddi3 and __udivdi3 from libgcc.a (and in
> > 2.95 these symbols are not tagged with .hidden) and then re-exports them
> > (which seems to be a perfectly normal thing for ld to do, if I'm
> > interpreting the docs correctly).
> >
> > With gcc-3.1 these symbols are tagged with .hidden in libgcc.a and thus
> > ld does not re-export them.
> >
> > Does this sound like a correct analysis? What shall we do here? Add the
> > libgcc symbols to glibc as Jakub suggested or change the way gcc-3.1
> > builds libgcc.a?
>
> This was a latent problem on all arches which did not export these
> routines from libc. Programs/libraries could just stop working if a library
> they depended on was upgraded/recompiled and did not need some
> of those routines internally any more (like e.g. if gcc optimized out some
> division or modulo).
> .hidden was added to libgcc.a specifically so that this problem won't be
> with us forever. If the routines aren't added as non-default version
> to libc, it just means there is a binary compatibility thick line between
> pre-gcc3.1 and gcc3.1+ shared libraries and since gcc3.1+ compiled
> shared libraries this problem won't occur ever again.
> My personal choice would be to add those as non-default versions to libc
> on arches with large enough installed base (especially ppc and ia64),
> though the decision is on Ulrich.
So, in case Uli agrees, what do I have to do to make it work? I've collected a
list of 14 libgcc symbols that ended up being re-exported from a shared lib:
T __ashldi3
T __ashrdi3
T __cmpdi2
T __divdi3
T __fixdfdi
T __fixsfdi
T __fixunsdfdi
T __fixunssfdi
T __floatdidf
T __floatdisf
T __moddi3
T __ucmpdi2
T __udivdi3
T __umoddi3
Where do I put them? Do I have to add code somewhere? Or pull in code from
libgcc.a?
Franz.