Re: [patch rfc] Per-frame frame-base

[Daniel Jacobowitz <drow@mvista.com>]

On Wed, Mar 26, 2003 at 04:51:13PM -0500, Andrew Cagney wrote:
> >On Wed, Mar 26, 2003 at 03:37:22PM -0500, Andrew Cagney wrote:
> >
> >>The implementation is very much modeled on the frame-unwind code.  Debug 
> >>readers are expected to register their own high level frame-base handler.
> >
> >
> >So what will the process for getting a dwarf2-debug-info frame
> >registered look like?
> 
> The current interface is identical to frame-unwind.
> 
> >How will we figure out that this function has
> >dwarf2 debug info?  It's not trivial... we don't have that information
> >around any more on a per-PC basis.
> 
> Ask the frame's function's symbol or block.

Symbols don't currently have this information, nor do blocks.

> You mean:
> 
> ``Assuming that .., return the base address of the parameters''
> 
> Which may be different to the address of the first parameter since, even 
> the first parameter's location may be specified as an offset from that 
> base?  Ok.

Right.  DW_OP_fbreg is used for both parameters and locals without
distinction; generally at 0 offset is something like the return
address or frame chain.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer