Re: RFA: dwarfout.c - emit DW_AT_LOCATION for global registervariables

[Andreas Jaeger <aj at suse dot de>]

Kevin Buettner <kevinb at redhat dot com> writes:

> I recently learned of a dwarf2 related bug in which insufficient
> debugging information is being generated for global declarations such
> as the following:
>
>     register void *current asm("$23");
>
> As I understand it, this tells gcc to user register 23 for the
> ``void *'' variable named "current".
>
> ``readelf -w'' shows that the following dwarf2 debug info is being
> generated for this variable:
>
>  <1><d13>: Abbrev Number: 3 (DW_TAG_variable)
>      DW_AT_name        : (indirect string, offset: 0x990): current 
>      DW_AT_decl_file   : 2 
>      DW_AT_decl_line   : 4 
>      DW_AT_type        : <d1e> 
>
> When I use the patch appended below, I see the same info as above
> along with the DW_AT_location attribute needed by a debugger to
> find the variable:
>
>      DW_AT_location    : 1 byte block: 67 	(DW_OP_reg23; )
> Prior to posting the patch (below) to this list, I asked for opinions
> regarding this patch from a few folks who are much more knowledgable
> about gcc than myself.  Jason Merrill responded that it looks good.

Please follow the GCC patch submission guidelines that mean that you
should bootstrap and regression test your patch on at least one
platform and state in your email where you've done so.  If you've done
the tests, just tell us - and if not, please do and tell us
afterwards;-).

Isn't this something that should go also into GCC 3.3?  Or is it only
relevant for GCC mainline?

Andreas
-- 
 Andreas Jaeger
  SuSE Labs aj at suse dot de
   private aj at arthur dot inka dot de
    http://www.suse.de/~aj