On 03/01/2013 07:30 PM, Pedro Alves wrote
> I do agree that trying to find the end of the prologue of a plt stub is futile.  We know plt stubs
> aren't "normal" functions, and don't have prologues.
>
> But, I do think the prologue analyzer still has a problem.  You should see this
> same issue with any small normal function (with no debug info) that happens to
> end up close enough to the end of its section.

   I agree, but normally there will be crtn* files which will placed 
after the noraml
function, so that the distance to the section with different alignment, 
for example .eh_frame_hdr,
will be long enough to prevent this happen.

>
> I suggest limiting the end address of the analysis with something like
> in tilegx_skip_prologue
>
> + /* Don't straddle a section boundary.  */
> + s = find_pc_section (start_pc);
> + end_pc = start_pc + 8 * TILEGX_BUNDLE_SIZE_IN_BYTES;
> + if (s != NULL)
> +   end_pc = min (end_pc, obj_section_endaddr (s));
>
>    return tilegx_analyze_prologue (gdbarch,
> 				  start_pc,
> -				  start_pc + 8 * TILEGX_BUNDLE_SIZE_IN_BYTES,
> +				  end_pc,
>
> and also, make tilegx_analyze_prologue never touch memory
> over end_addr.  It doesn't seem to take that care currently?
    I think this fix make sense, and tilegx_analyze_prologue has glitch, 
it will ignore "end_pc" to some extent.
  the prefetch buffer in tilegx_analyze_prologue should consider the end_pc.

    I have tested the new patch by rerun dejagnu, please review, thanks.

    gdb/ChangeLog:

         * tilegx-tdep.c (tilegx_analyze_prologue): Improve the evaluation
         of "instbuf_size".
         (tilegx_skip_prologue): Improve the evaluation of the end address
         for prologue analyze.

-- 
Regards,
Jiong. Wang
Tilera Corporation.