Re: fix "too much information" bug w/ "info vector" on PowerPC

Paul Gilliam
2005-08-31T20:26:17Z

On Tuesday 30 August 2005 14:42, Jim Blandy wrote:
> - Could you also add comments above the definitions of
> tdep->ppc_vr0_regnum and tdep->ppc_ev0_regnum in ppc-tdep.h?
> Perhaps such comments could have prevented the bugs's appearance in
> the first place.

Here is the new patch with comments added/chanded in ppc-tdep.h

If I hear no objections, I'll commit this tomorrow.

-=# Paul #=-

2005-08-30 Paul Gilliam <pgilliam@us.ibm.com>

* ppc-tdep.h: better explanation of using -1 for nonexistant registers
* rs6000-tdep.c (rs6000_register_reggroup_p): don't assume that
tdep->ppc_vr0_regnum or tdep->ppc_ev0_regnum are not -1

Index: ppc-tdep.h
===================================================================
RCS file: /cvs/src/src/gdb/ppc-tdep.h,v
retrieving revision 1.46
diff -c -3 -p -r1.46 ppc-tdep.h
*** ppc-tdep.h 25 May 2005 03:12:13 -0000 1.46
--- ppc-tdep.h 31 Aug 2005 20:06:35 -0000
*************** struct gdbarch_tdep
*** 152,177 ****
int ppc_ctr_regnum; /* Count register */
int ppc_xer_regnum; /* Integer exception register */

! /* On PPC and RS6000 variants that have no floating-point
! registers, the next two members will be -1. */
int ppc_fp0_regnum; /* floating-point register 0 */
! int ppc_fpscr_regnum; /* Floating point status and condition
! register */

! int ppc_sr0_regnum; /* segment register 0, or -1 on
! variants that have no segment
! registers. */

int ppc_mq_regnum; /* Multiply/Divide extension register */
int ppc_vr0_regnum; /* First AltiVec register */
int ppc_vrsave_regnum; /* Last AltiVec register */
int ppc_ev0_upper_regnum; /* First GPR upper half register */
int ppc_ev0_regnum; /* First ev register */
int ppc_ev31_regnum; /* Last ev register */
int ppc_acc_regnum; /* SPE 'acc' register */
int ppc_spefscr_regnum; /* SPE 'spefscr' register */
! int lr_frame_offset; /* Offset to ABI specific location where
! link register is saved. */

/* An array of integers, such that sim_regno[I] is the simulator
register number for GDB register number I, or -1 if the
--- 152,184 ----
int ppc_ctr_regnum; /* Count register */
int ppc_xer_regnum; /* Integer exception register */

! /* Not all PPC and RS6000 variants will have the registers
! represented below. A -1 is used to indicate that the register
! is not present in this variant. */
!
! /* Floating-point registers. */
int ppc_fp0_regnum; /* floating-point register 0 */
! int ppc_fpscr_regnum; /* fp status and condition register */

! /* Segment registers */
! int ppc_sr0_regnum; /* segment register 0 */

+ /* Used in some older Power architectures. */
int ppc_mq_regnum; /* Multiply/Divide extension register */
+
+ /* Altivec registers */
int ppc_vr0_regnum; /* First AltiVec register */
int ppc_vrsave_regnum; /* Last AltiVec register */
int ppc_ev0_upper_regnum; /* First GPR upper half register */
+
+ /* SPE registers. */
int ppc_ev0_regnum; /* First ev register */
int ppc_ev31_regnum; /* Last ev register */
int ppc_acc_regnum; /* SPE 'acc' register */
int ppc_spefscr_regnum; /* SPE 'spefscr' register */
!
! /* Offset to ABI specific location where link register is saved. */
! int lr_frame_offset;

/* An array of integers, such that sim_regno[I] is the simulator
register number for GDB register number I, or -1 if the
Index: rs6000-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/rs6000-tdep.c,v
retrieving revision 1.241
diff -c -3 -p -r1.241 rs6000-tdep.c
*** rs6000-tdep.c 25 May 2005 03:12:13 -0000 1.241
--- rs6000-tdep.c 31 Aug 2005 20:06:35 -0000
*************** rs6000_register_reggroup_p (struct gdbar
*** 1882,1890 ****
if (group == float_reggroup)
return float_p;

! vector_p = ((regnum >= tdep->ppc_vr0_regnum
&& regnum < tdep->ppc_vr0_regnum + 32)
! || (regnum >= tdep->ppc_ev0_regnum
&& regnum < tdep->ppc_ev0_regnum + 32)
|| regnum == tdep->ppc_vrsave_regnum
|| regnum == tdep->ppc_acc_regnum
--- 1882,1892 ----
if (group == float_reggroup)
return float_p;

! vector_p = ((tdep->ppc_vr0_regnum >= 0
! && regnum >= tdep->ppc_vr0_regnum
&& regnum < tdep->ppc_vr0_regnum + 32)
! || (tdep->ppc_ev0_regnum >= 0
! && regnum >= tdep->ppc_ev0_regnum
&& regnum < tdep->ppc_ev0_regnum + 32)
|| regnum == tdep->ppc_vrsave_regnum
|| regnum == tdep->ppc_acc_regnum