[patch] Fix gdb.cp/gdb2495.exp regression with gcc-4.7

[Jan Kratochvil]

On Mon, 02 Jan 2012 15:44:02 +0100, Pedro Alves wrote:
> I see.  That '_Unwind_IsSignalFrame(context)' is there to cancel out
> the '- 1' for signal frames.  Ideally, the same treatment would be
> applied for gdb's dummy frame, perhaps by having gdb itself change
> `context->flags' making libunwind treat it as a signal frame.  I
> have no idea whether that's feasible.  Oh well.

It needs to be universal, at least for both libgcc and libunwind, via the
_Unwind_* API.

And this signal frame indication (such as 'S' in .eh_frame CIE augmentation)
would need to be present in the frame for the called code.  The caller frame
<function called from gdb> is already too late, that one gets already wrongly
unwound.

I do not find it feasible myself.


Thanks,
Jan