Re: [PING][PATCH] Fix for prologue processing on PowerPC

[Pedro Franco de Carvalho <pedromfc@linux.vnet.ibm.com>]

Nikola Prica <nikola.prica@rt-rk.com> writes:

> Hi Pedro,
>
> I've just seen that changed version of patch was not attached.
>
> Best regards,
>
> Nikola Prica
> From 3564cd3be620bb39ca615919148fa0d949284d35 Mon Sep 17 00:00:00 2001
> From: Prica <nprica@rt-rk.com>
> Date: Thu, 9 Nov 2017 13:10:48 +0100
> Subject: [PATCH] Fix for prologue processing on PowerPC
>
>   One of conditions in skip_prologue() is never visited because it
>   expects non shifted `lr_reg`. That condition is supposed to set PC
>   offset. When body of this condition is visited PC offset is set and
>   there will be no need to look for it in next frames nor to use frame
>   unwind directives.
>
>   gdb/ChangeLog:
>   	*rs6000-tdep.c (skip_prologue): Remove shifting for lr_reg
>   	and assign shifted lr_reg to fdata->lr_register when lr_reg is
>   	set. If iteration do not hit lim_pc lr_register is set as -1.
> ---
>  gdb/rs6000-tdep.c | 13 ++++++++-----
>  1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c
> index 6c44995..6f05ef5 100644
> --- a/gdb/rs6000-tdep.c
> +++ b/gdb/rs6000-tdep.c
> @@ -1655,9 +1655,12 @@ skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc, CORE_ADDR lim_pc,
>  	     remember just the first one, but skip over additional
>  	     ones.  */
>  	  if (lr_reg == -1)
> -	    lr_reg = (op & 0x03e00000) >> 21;
> -          if (lr_reg == 0)
> -            r0_contains_arg = 0;
> +      {
> +        lr_reg = (op & 0x03e00000);
> +        fdata->lr_register = lr_reg >> 21;
> +        if (lr_reg == 0)
> +          r0_contains_arg = 0;
> +      }
>  	  continue;
>  	}
>        else if ((op & 0xfc1fffff) == 0x7c000026)
> @@ -2180,8 +2183,8 @@ skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc, CORE_ADDR lim_pc,
>      }
>  #endif /* 0 */
>
> -  if (pc == lim_pc && lr_reg >= 0)
> -    fdata->lr_register = lr_reg;
> +  if (pc != lim_pc)
> +    fdata->lr_register = -1;
>
>    fdata->offset = -fdata->offset;
>    return last_prologue_pc;
> -- 
> 2.7.4