Re: Problem with location lists and variables on stack

[Daniel Berlin <dberlin at dberlin dot org>]

> > Daniel Berlin has already written support for GCC to generate location
> > list for DW_AT_frame_base.
> > DW_AT_frame_base is a location list as any other (actually only the
> > offsets relatively to original stack pointer at function start are 
> > needed).
> > GDB then uses this location list to adjust offsets of other variables
> > addressed using stack pointer.
> > With Daniel Jacobowitz's fix for GDB it works :-)
> > i.e. you can see correct values for variables located on stack
> > even when stack pointer changes because of push, pop, etc.
> >
> > Current GCC patch can be downloaded from:
> > http://artax.karlin.mff.cuni.cz/~zlomj9am/download/vt-main.patch
> >
> > (because currently GCC is in stage 2 it has to wait until GCC is in 
> > stage 1)
>
> I suppose this is true, but it's really unfortunate.

I'm not so sure it's true.

This isn't a major change, really and it's only going to make things 
better (We didn't use to support -O2 -g at all, really, and now we can. 
 There can't be any regressions from an unsupported state to a 
supported one).  It's also not an optimization pass, so the risk is 
relatively low.

> --
> Daniel Jacobowitz
> MontaVista Software                         Debian GNU/Linux Developer