Re: [PATCH 1/3] Add sp_regnum_from_eax and pc_regnum_from_eax

[Mark Kettenis <mark dot kettenis at xs4all dot nl>]

> Date: Thu, 21 Jun 2012 11:14:52 -0700
> From: "H.J. Lu" <hongjiu.lu@intel.com>
> 
> Hi,
> 
> Here are the first of the last 3 patches for x32 support in GDB.  This
> patch maps $pc to $eip and $sp to $esp for x32.  OK to install?

The pseudo register handling code is getting too complex :(.  I feel
that hiding the set_gdbarch_pc_regnum() and set_gdbarch_sp_regnum()
calls in i386-tdep.c isn't the right approach.  But I haven't found a
better one yet :(.

> ---
> 	* amd64-tdep.c (amd64_x32_init_abi): Set sp_regnum_from_eax to
> 	AMD64_RSP_REGNUM and pc_regnum_from_eax to AMD64_RIP_REGNUM.
> 
> 	* i386-tdep.c (i386_gdbarch_init): Initialize sp_regnum_from_eax
> 	and pc_regnum_from_eax to -1.  Update SP regnum from
> 	sp_regnum_from_eax and PC regnum from pc_regnum_from_eax if
> 	needed.
> 
> 	* i386-tdep.h (gdbarch_tdep): Add sp_regnum_from_eax and
> 	pc_regnum_from_eax.
> 
> ---
>  gdb/amd64-tdep.c |    3 +++
>  gdb/i386-tdep.c  |   11 +++++++++++
>  gdb/i386-tdep.h  |    8 ++++++++
>  3 files changed, 22 insertions(+), 0 deletions(-)
> 
> diff --git a/gdb/amd64-tdep.c b/gdb/amd64-tdep.c
> index 8ae1142..5424926 100644
> --- a/gdb/amd64-tdep.c
> +++ b/gdb/amd64-tdep.c
> @@ -2946,6 +2946,9 @@ amd64_x32_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
>      tdesc = tdesc_x32;
>    tdep->tdesc = tdesc;
>  
> +  tdep->sp_regnum_from_eax = AMD64_RSP_REGNUM;
> +  tdep->pc_regnum_from_eax = AMD64_RIP_REGNUM;
> +
>    tdep->num_dword_regs = 17;
>    set_tdesc_pseudo_register_type (gdbarch, amd64_x32_pseudo_register_type);
>  
> diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
> index fd5969d..6a02906 100644
> --- a/gdb/i386-tdep.c
> +++ b/gdb/i386-tdep.c
> @@ -7805,6 +7805,9 @@ i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
>    tdep->num_mmx_regs = 8;
>    tdep->num_ymm_regs = 0;
>  
> +  tdep->sp_regnum_from_eax = -1;
> +  tdep->pc_regnum_from_eax = -1;
> +
>    tdesc_data = tdesc_data_alloc ();
>  
>    set_gdbarch_relocate_instruction (gdbarch, i386_relocate_instruction);
> @@ -7849,6 +7852,14 @@ i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
>        /* Support dword pseudo-register if it hasn't been disabled.  */
>        tdep->eax_regnum = ymm0_regnum;
>        ymm0_regnum += tdep->num_dword_regs;
> +      if (tdep->sp_regnum_from_eax != -1)
> +	set_gdbarch_sp_regnum (gdbarch,
> +			       (tdep->eax_regnum
> +				+ tdep->sp_regnum_from_eax));
> +      if (tdep->pc_regnum_from_eax != -1)
> +	set_gdbarch_pc_regnum (gdbarch,
> +			       (tdep->eax_regnum
> +				+ tdep->pc_regnum_from_eax));
>      }
>    else
>      tdep->eax_regnum = -1;
> diff --git a/gdb/i386-tdep.h b/gdb/i386-tdep.h
> index 5f233f5..76afdce 100644
> --- a/gdb/i386-tdep.h
> +++ b/gdb/i386-tdep.h
> @@ -149,6 +149,14 @@ struct gdbarch_tdep
>       of pseudo dword register support.  */
>    int eax_regnum;
>  
> +  /* Register number for SP, relative to %eax.  Set this to -1 to
> +     indicate the absence of pseudo SP register support.  */
> +  int sp_regnum_from_eax;
> +
> +  /* Register number for PC, relative to %eax.  Set this to -1 to
> +     indicate the absence of pseudo PC register support.  */
> +  int pc_regnum_from_eax;
> +
>    /* Number of core registers.  */
>    int num_core_regs;
>  
> -- 
> 1.7.6.5
> 
>