[PING] Fix for prologue processing on PowerPC

  Hi Pedro,

Thank you for your review and patience. I'm really grateful.

Can someone commit this patch?

Thanks,

Nikola
  

Looks good to me. Just two details for the testsuite changelog,
the filenames in the entry don't match the actual filenames, and there's
a space between the "*" and the entries.

I tested the patch with ppc64le and ppc32, and it works. No regressions.

Thanks!
Pedro

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

> Hi Pedro,
>
> Thank you for your review and patience. I'm really grateful.
>
> Can someone commit this patch?
>
> Thanks,
>
> Nikola
> From 4b32b0441739d7daa931b13029f1c8215a4b1f4e Mon Sep 17 00:00:00 2001
> From: Prica <nprica@rt-rk.com>
> Date: Thu, 11 Jan 2018 14:49:15 +0100
> Subject: [PATCH] Fix for prologue processing on PowerPc
>
> One of conditions in skip_prologue() was never visited if there was mflr
> instruction that moves the link register to a register different thant r0.
> This condition expects non shifted value of `lr_reg`. Previously offset
> of link register was never saved for registers different than r0.
>
> gdb/ChangeLog:
>
> 2018-01-27 Nikola Prica  <nikola.prica@rt-rk.com>
>
>         *rs6000-tdep.c (skip_prologue): Remove shifting for lr_reg and
>          assign shifted lr_reg to fdata->lr_register when lr_reg is set.
>
> gdb/testsuite/ChangeLog:
>
> 2018-01-27 Nikola Prica  <nikola.prica@rt-rk.com>
>
>         *gdb.arch/ppc-prologue-frame.s: New file.
>         *gdb.arch/ppc-prologue-frame.c: Likewise.
>         *gdb.arch/ppr-prologue-frame.exp: Likewise.
> ---
>  gdb/rs6000-tdep.c                                 |  4 +--
>  gdb/testsuite/gdb.arch/powerpc-prologue-frame.S   | 35 +++++++++++++++++++
>  gdb/testsuite/gdb.arch/powerpc-prologue-frame.c   | 28 ++++++++++++++++
>  gdb/testsuite/gdb.arch/powerpc-prologue-frame.exp | 41 +++++++++++++++++++++++
>  4 files changed, 106 insertions(+), 2 deletions(-)
>  create mode 100644 gdb/testsuite/gdb.arch/powerpc-prologue-frame.S
>  create mode 100644 gdb/testsuite/gdb.arch/powerpc-prologue-frame.c
>  create mode 100644 gdb/testsuite/gdb.arch/powerpc-prologue-frame.exp
>
> diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c
> index e5a265d..da5182e 100644
> --- a/gdb/rs6000-tdep.c
> +++ b/gdb/rs6000-tdep.c
> @@ -1654,7 +1654,7 @@ 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;
> +	    lr_reg = (op & 0x03e00000);
>            if (lr_reg == 0)
>              r0_contains_arg = 0;
>  	  continue;
> @@ -2180,7 +2180,7 @@ 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;
> +    fdata->lr_register = lr_reg >> 21;
>
>    fdata->offset = -fdata->offset;
>    return last_prologue_pc;
> diff --git a/gdb/testsuite/gdb.arch/powerpc-prologue-frame.S b/gdb/testsuite/gdb.arch/powerpc-prologue-frame.S
> new file mode 100644
> index 0000000..e30ca23
> --- /dev/null
> +++ b/gdb/testsuite/gdb.arch/powerpc-prologue-frame.S
> @@ -0,0 +1,35 @@
> +/* This test is part of GDB, the GNU debugger.
> +
> +   Copyright 2018 Free Software Foundation, Inc.
> +
> +   This program is free software; you can redistribute it and/or modify
> +   it under the terms of the GNU General Public License as published by
> +   the Free Software Foundation; either version 3 of the License, or
> +   (at your option) any later version.
> +
> +   This program is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +   GNU General Public License for more details.
> +
> +   You should have received a copy of the GNU General Public License
> +   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
> +
> +#include <ppc-asm.h>
> +
> +FUNC_START(foo)
> +	stwu 1,-32(1)
> +	mflr 3
> +	stw 3,36(1)
> +	stw 31,28(1)
> +	mr 31,1
> +	bl bar
> +	mr 9,3
> +	mr 3,9
> +	addi 11,31,32
> +	lwz 0,4(11)
> +	mtlr 0
> +	lwz 31,-4(11)
> +	mr 1,11
> +	blr
> +FUNC_END(foo)
> diff --git a/gdb/testsuite/gdb.arch/powerpc-prologue-frame.c b/gdb/testsuite/gdb.arch/powerpc-prologue-frame.c
> new file mode 100644
> index 0000000..8cab6f2
> --- /dev/null
> +++ b/gdb/testsuite/gdb.arch/powerpc-prologue-frame.c
> @@ -0,0 +1,28 @@
> +/* This test is part of GDB, the GNU debugger.
> +
> +   Copyright 2018 Free Software Foundation, Inc.
> +
> +   This program is free software; you can redistribute it and/or modify
> +   it under the terms of the GNU General Public License as published by
> +   the Free Software Foundation; either version 3 of the License, or
> +   (at your option) any later version.
> +
> +   This program is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +   GNU General Public License for more details.
> +
> +   You should have received a copy of the GNU General Public License
> +   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
> +
> +int bar()
> +{
> +  return 0;
> +}
> +
> +int foo();
> +
> +int main(void)
> +{
> +  return foo();
> +}
> diff --git a/gdb/testsuite/gdb.arch/powerpc-prologue-frame.exp b/gdb/testsuite/gdb.arch/powerpc-prologue-frame.exp
> new file mode 100644
> index 0000000..d26314b
> --- /dev/null
> +++ b/gdb/testsuite/gdb.arch/powerpc-prologue-frame.exp
> @@ -0,0 +1,41 @@
> +# Copyright 2018 Free Software Foundation, Inc.
> +
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 3 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program.  If not, see <http://www.gnu.org/licenses/>
> +
> +if {![istarget "powerpc-*-*"] } {
> +    verbose "Skipping powerpc back trace test."
> +    return
> +}
> +
> +standard_testfile .c .S
> +set binfile [standard_output_file ${testfile}]
> +
> +if {[gdb_compile \
> +      [list ${srcdir}/${subdir}/$srcfile ${srcdir}/${subdir}/$srcfile2] \
> +      "${binfile}" executable {}] != ""} {
> +    untested "failed to build $binfile"
> +    return -1
> +}
> +
> +
> +clean_restart ${binfile}
> +
> +if ![runto bar] {
> +  untested "could not run to bar"
> +  return -1
> +}
> +
> +gdb_test "bt" \
> +         "#0\[ \t\]*$hex in bar.*\r\n#1\[ \t\]*$hex in foo.*\r\n#2\[ \t\]*$hex in main.*" \
> +         "Backtrace to the main frame"
> -- 
> 2.7.4