missing symbols in libstdc++.so.6 built from the 4.9 branch

[Hans-Peter Nilsson]

On Tue, 1 Jul 2014, Jonathan Wakely wrote:

> On 1 July 2014 20:58, John David Anglin wrote:
> > On 1-Jul-14, at 5:32 AM, Jonathan Wakely wrote:
> >
> >> On 1 July 2014 09:40, Matthias Klose wrote:
> >>>
> >>> - HPPA (build log [2]), is missing all the future_base symbols and
> >>>   exception_ptr13exception symbols, current_exception and
> >>>   rethrow_exception.

Apparently the cheat mentioned below didn't fully work. :)

> >> This implies ATOMIC_INT_LOCK_FREE <= 1 for that target. Our future and
> >> exception_ptr implementations rely on usable atomics.
> >
> >
> > ARM and HPPA use kernel assisted libraries for atomic support.  Not exactly
> > lock free, but possibly good enough...
> >
> > Currently, c-cppbuiltin.c doesn't provide proper defines for this support.
> > We
> > currently define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4, etc, in
> > pa-linux.h.

I thought that was cheating!  1/2 :)

>  I'll experiment with defining ATOMIC_INT_LOCK_FREE there.
>
> It should already be defined,

Yes, if the proper insn patterns are in place, those macros are
automatically defined.  They aren't if library functions are
called, regardless of lock-freelessness of those functions.

brgds, H-P