Re: [PATCH] Fix for gdb.base/pc-fp.exp.

["Ulrich Weigand" <uweigand@de.ibm.com>]

Carl Love wrote:

> That said, the code "set_gdbarch_deprecated_fp_regnum
> (gdbarch, PPC_R0_REGNUM + 1);" sets up register r1 as the frame pointer.
> Register r1 is no longer used to hold the frame pointer on Power.  By
> removing the fp definition for Power in GDB, it causes GDB to fall back
> to the call get_frame_base_address (frame) which returns the correct value
> depending on the specific senario but most of the time is the DWARF
> canonical frame address.

That's true.  In fact, the one place that really cares about the value
returned via $fp is varobj.c:find_frame_addr_in_frame_chain, since you're
supposed to use the value of $fp to identify a frame for MI routines.
And there we explicitly assume that this value matches the value returned
by get_frame_base_address.

> 2016-08-22  Carl Love  <cel@us.ibm.com>
> 
> 	* rs6000-tdep.c (rs6000_gdbarch_init): Remove deprecated call set_gdbarch_deprecated_fp_regnum()
> 	from Power architecture initialization function.

Please watch the 80-char line length limit, which holds for the ChangeLog
as well.  In fact, the text can be shortened anyway: "deprecated" is
redundant (included in the function name), and likewise is "from Power
architecture initialization function" (you already specified which
function --rs6000_gdbarch_init-- you're modifying).  I'd suggest:

 	* rs6000-tdep.c (rs6000_gdbarch_init): Remove call to
	set_gdbarch_deprecated_fp_regnum.

Patch is OK.

Thanks,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU/Linux compilers and toolchain
  Ulrich.Weigand@de.ibm.com