Re: regarding transparent data ranges (in tracepoint support)

[Daniel Jacobowitz <drow at mvista dot com>]

On Wed, Nov 19, 2003 at 08:25:37AM -0800, ankit thukral wrote:
> 
> --- Jim Blandy <jimb@redhat.com> wrote:
> > 
> > ankit thukral <ankit_plug@yahoo.com> writes:
> > 
> > > hi all,
> > >      i read about the transparent data ranges and
> > > learned that data in these ranges are not supposed
> > to
> > > be collected by the remote stub since they belong
> > to
> > > read-only segment of the debuggee.my problem is :
> > a
> > > TSTART would start the debuggee and it may so
> > happen
> > > that the debuggee finishes executing.at this
> > point,if
> > > the GDB requests for some data in the transparent
> > data
> > > range,then how can the remote stub provide it with
> > one
> > > since the debuggee has exited ?
> > 
> > If the target is a gdbserver, then it would need to
> > read the bytes
> > from the executable file.  This is easy to do with
> > BFD, but if I
> > remember right, gdbserver doesn't use BFD at the
> > moment; not sure how
> > to get around that.
> > 
> > If the target is an embedded system, then presumably
> > the transparent
> > data ranges correspond to ROM regions, so the data
> > is still there.
> 
> 
> 
>   how about setting a (internal) breakpoint in the
> debuggee which would prevent it from exiting even
> though it has finished executing main(),and then
> entertain GDB requests for the transparent (or
> read-only) memory regions by reading from the memory
> of the debuggee???

That would work (but be wasteful).  At least on Linux, you could read
/proc/pid/maps to find what ranges correspond to where in what file,
and save that information.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer