[PATCH 2/4] Don't use arm_regmap and arm_num_regs in arm_fill_gregset and arm_store_gregset

[PATCH 2/4] Don't use arm_regmap and arm_num_regs in arm_fill_gregset and arm_store_gregset

[Yao Qi]

In order to align with arm-linux-nat.c counterparts, we don't use
arm_num_regs and arm_regmap in functions arm_fill_gregset and
arm_store_gregset.  Instead, we use register numbers.  With this
patch applied, arm_fill_gregset and arm_store_gregset don't need
arm_num_regs and arm_regmap, and they will be moved to a separate
file shared for both arm and aarch64 in the following patch series.

gdb/gdbserver:

2015-07-28  Yao Qi  <yao.qi@linaro.org>

	* linux-arm-low.c: Include arch/arm.h.
	(arm_fill_gregset): Don't use arm_num_regs and arm_regmap.
	(arm_store_gregset): Likewise.
---
 gdb/gdbserver/linux-arm-low.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/gdb/gdbserver/linux-arm-low.c b/gdb/gdbserver/linux-arm-low.c
index 14c96a3..0a34379 100644
--- a/gdb/gdbserver/linux-arm-low.c
+++ b/gdb/gdbserver/linux-arm-low.c
@@ -18,6 +18,7 @@
 
 #include "server.h"
 #include "linux-low.h"
+#include "arch/arm.h"
 
 /* Don't include elf.h if linux/elf.h got included by gdb_proc_service.h.
    On Bionic elf.h and linux/elf.h have conflicting definitions.  */
@@ -154,10 +155,12 @@ static void
 arm_fill_gregset (struct regcache *regcache, void *buf)
 {
   int i;
+  uint32_t *regs = buf;
 
-  for (i = 0; i < arm_num_regs; i++)
-    if (arm_regmap[i] != -1)
-      collect_register (regcache, i, ((char *) buf) + arm_regmap[i]);
+  for (i = ARM_A1_REGNUM; i <= ARM_PC_REGNUM; i++)
+    collect_register (regcache, i, &regs[i]);
+
+  collect_register (regcache, ARM_PS_REGNUM, &regs[16]);
 }
 
 static void
@@ -165,13 +168,16 @@ arm_store_gregset (struct regcache *regcache, const void *buf)
 {
   int i;
   char zerobuf[8];
+  const uint32_t *regs = buf;
 
   memset (zerobuf, 0, 8);
-  for (i = 0; i < arm_num_regs; i++)
-    if (arm_regmap[i] != -1)
-      supply_register (regcache, i, ((char *) buf) + arm_regmap[i]);
-    else
-      supply_register (regcache, i, zerobuf);
+  for (i = ARM_A1_REGNUM; i <= ARM_PC_REGNUM; i++)
+    supply_register (regcache, i, &regs[i]);
+
+  for (; i < ARM_PS_REGNUM; i++)
+    supply_register (regcache, i, zerobuf);
+
+  supply_register (regcache, ARM_PS_REGNUM, &regs[16]);
 }
 
 static void
-- 
1.9.1

[RFC 1/4] Move ARM register numbers enum to arch/arm.h

[Yao Qi]

This patch moves ARM register numbers enum to arch/arm.h, so that it
can used by GDBserver too.

This patch is a RFC because it creates a new directory gdb/arch in which
arch-specific or target-specific files are placed.

gdb:

2015-07-28  Yao Qi  <yao.qi@linaro.org>

	* arm-tdep.h (enum gdb_regnum): Move it to ...
	* arch/arm.h: ... here.  New file.
	* Makefile.in (HFILES_NO_SRCDIR): Add arch/arm.h.
---
 gdb/Makefile.in |  2 +-
 gdb/arch/arm.h  | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 gdb/arm-tdep.h  | 39 +-----------------------------------
 3 files changed, 63 insertions(+), 39 deletions(-)
 create mode 100644 gdb/arch/arm.h

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index e7fefd9..4080ba4 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -983,7 +983,7 @@ common/common-debug.h common/cleanups.h common/gdb_setjmp.h \
 common/common-exceptions.h target/target.h common/symbol.h \
 common/common-regcache.h fbsd-tdep.h nat/linux-personality.h \
 common/fileio.h nat/x86-linux.h nat/x86-linux-dregs.h \
-nat/linux-namespaces.h
+nat/linux-namespaces.h arch/arm.h
 
 # Header files that already have srcdir in them, or which are in objdir.
 
diff --git a/gdb/arch/arm.h b/gdb/arch/arm.h
new file mode 100644
index 0000000..e0eed60
--- /dev/null
+++ b/gdb/arch/arm.h
@@ -0,0 +1,61 @@
+/* Common target dependent code for GDB on ARM systems.
+   Copyright (C) 2002-2015 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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/>.  */
+
+#ifndef ARM_H
+#define ARM_H
+
+/* Register numbers of various important registers.  */
+
+enum gdb_regnum {
+  ARM_A1_REGNUM = 0,		/* first integer-like argument */
+  ARM_A4_REGNUM = 3,		/* last integer-like argument */
+  ARM_AP_REGNUM = 11,
+  ARM_IP_REGNUM = 12,
+  ARM_SP_REGNUM = 13,		/* Contains address of top of stack */
+  ARM_LR_REGNUM = 14,		/* address to return to from a function call */
+  ARM_PC_REGNUM = 15,		/* Contains program counter */
+  ARM_F0_REGNUM = 16,		/* first floating point register */
+  ARM_F3_REGNUM = 19,		/* last floating point argument register */
+  ARM_F7_REGNUM = 23, 		/* last floating point register */
+  ARM_FPS_REGNUM = 24,		/* floating point status register */
+  ARM_PS_REGNUM = 25,		/* Contains processor status */
+  ARM_WR0_REGNUM,		/* WMMX data registers.  */
+  ARM_WR15_REGNUM = ARM_WR0_REGNUM + 15,
+  ARM_WC0_REGNUM,		/* WMMX control registers.  */
+  ARM_WCSSF_REGNUM = ARM_WC0_REGNUM + 2,
+  ARM_WCASF_REGNUM = ARM_WC0_REGNUM + 3,
+  ARM_WC7_REGNUM = ARM_WC0_REGNUM + 7,
+  ARM_WCGR0_REGNUM,		/* WMMX general purpose registers.  */
+  ARM_WCGR3_REGNUM = ARM_WCGR0_REGNUM + 3,
+  ARM_WCGR7_REGNUM = ARM_WCGR0_REGNUM + 7,
+  ARM_D0_REGNUM,		/* VFP double-precision registers.  */
+  ARM_D31_REGNUM = ARM_D0_REGNUM + 31,
+  ARM_FPSCR_REGNUM,
+
+  ARM_NUM_REGS,
+
+  /* Other useful registers.  */
+  ARM_FP_REGNUM = 11,		/* Frame register in ARM code, if used.  */
+  THUMB_FP_REGNUM = 7,		/* Frame register in Thumb code, if used.  */
+  ARM_NUM_ARG_REGS = 4, 
+  ARM_LAST_ARG_REGNUM = ARM_A4_REGNUM,
+  ARM_NUM_FP_ARG_REGS = 4,
+  ARM_LAST_FP_ARG_REGNUM = ARM_F3_REGNUM
+};
+
+#endif
diff --git a/gdb/arm-tdep.h b/gdb/arm-tdep.h
index f81679a..3e06f79 100644
--- a/gdb/arm-tdep.h
+++ b/gdb/arm-tdep.h
@@ -24,44 +24,7 @@ struct gdbarch;
 struct regset;
 struct address_space;
 
-/* Register numbers of various important registers.  */
-
-enum gdb_regnum {
-  ARM_A1_REGNUM = 0,		/* first integer-like argument */
-  ARM_A4_REGNUM = 3,		/* last integer-like argument */
-  ARM_AP_REGNUM = 11,
-  ARM_IP_REGNUM = 12,
-  ARM_SP_REGNUM = 13,		/* Contains address of top of stack */
-  ARM_LR_REGNUM = 14,		/* address to return to from a function call */
-  ARM_PC_REGNUM = 15,		/* Contains program counter */
-  ARM_F0_REGNUM = 16,		/* first floating point register */
-  ARM_F3_REGNUM = 19,		/* last floating point argument register */
-  ARM_F7_REGNUM = 23, 		/* last floating point register */
-  ARM_FPS_REGNUM = 24,		/* floating point status register */
-  ARM_PS_REGNUM = 25,		/* Contains processor status */
-  ARM_WR0_REGNUM,		/* WMMX data registers.  */
-  ARM_WR15_REGNUM = ARM_WR0_REGNUM + 15,
-  ARM_WC0_REGNUM,		/* WMMX control registers.  */
-  ARM_WCSSF_REGNUM = ARM_WC0_REGNUM + 2,
-  ARM_WCASF_REGNUM = ARM_WC0_REGNUM + 3,
-  ARM_WC7_REGNUM = ARM_WC0_REGNUM + 7,
-  ARM_WCGR0_REGNUM,		/* WMMX general purpose registers.  */
-  ARM_WCGR3_REGNUM = ARM_WCGR0_REGNUM + 3,
-  ARM_WCGR7_REGNUM = ARM_WCGR0_REGNUM + 7,
-  ARM_D0_REGNUM,		/* VFP double-precision registers.  */
-  ARM_D31_REGNUM = ARM_D0_REGNUM + 31,
-  ARM_FPSCR_REGNUM,
-
-  ARM_NUM_REGS,
-
-  /* Other useful registers.  */
-  ARM_FP_REGNUM = 11,		/* Frame register in ARM code, if used.  */
-  THUMB_FP_REGNUM = 7,		/* Frame register in Thumb code, if used.  */
-  ARM_NUM_ARG_REGS = 4, 
-  ARM_LAST_ARG_REGNUM = ARM_A4_REGNUM,
-  ARM_NUM_FP_ARG_REGS = 4,
-  ARM_LAST_FP_ARG_REGNUM = ARM_F3_REGNUM
-};
+#include "arch/arm.h"
 
 /* Size of integer registers.  */
 #define INT_REGISTER_SIZE		4
-- 
1.9.1

[PATCH 3/4] Use regcache->tdesc instead of arm_hwcap

[Yao Qi]

arm_hwcap is a global variable, and we should avoid using it as much
as we can.  Instead of checking arm_hwcap, we can check whether
regcache->tdesc is a certain kind of target description.  This is
what this patch does.

gdb/gdbserver:

2015-07-28  Yao Qi  <yao.qi@linaro.org>

	* linux-arm-low.c (arm_fill_wmmxregset): Don't use arm_hwcap.
	Use regcache->tdesc instead.
	(arm_store_wmmxregset): Likewise.
	(arm_fill_vfpregset): Likewise.
	(arm_store_vfpregset): Likewise.
---
 gdb/gdbserver/linux-arm-low.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/gdb/gdbserver/linux-arm-low.c b/gdb/gdbserver/linux-arm-low.c
index 0a34379..02a1c08 100644
--- a/gdb/gdbserver/linux-arm-low.c
+++ b/gdb/gdbserver/linux-arm-low.c
@@ -185,7 +185,7 @@ arm_fill_wmmxregset (struct regcache *regcache, void *buf)
 {
   int i;
 
-  if (!(arm_hwcap & HWCAP_IWMMXT))
+  if (regcache->tdesc != tdesc_arm_with_iwmmxt)
     return;
 
   for (i = 0; i < 16; i++)
@@ -202,7 +202,7 @@ arm_store_wmmxregset (struct regcache *regcache, const void *buf)
 {
   int i;
 
-  if (!(arm_hwcap & HWCAP_IWMMXT))
+  if (regcache->tdesc != tdesc_arm_with_iwmmxt)
     return;
 
   for (i = 0; i < 16; i++)
@@ -219,13 +219,13 @@ arm_fill_vfpregset (struct regcache *regcache, void *buf)
 {
   int i, num, base;
 
-  if (!(arm_hwcap & HWCAP_VFP))
-    return;
-
-  if ((arm_hwcap & (HWCAP_VFPv3 | HWCAP_VFPv3D16)) == HWCAP_VFPv3)
+  if (regcache->tdesc == tdesc_arm_with_neon
+      || regcache->tdesc == tdesc_arm_with_vfpv3)
     num = 32;
-  else
+  else if (regcache->tdesc == tdesc_arm_with_vfpv2)
     num = 16;
+  else
+    return;
 
   base = find_regno (regcache->tdesc, "d0");
   for (i = 0; i < num; i++)
@@ -239,13 +239,13 @@ arm_store_vfpregset (struct regcache *regcache, const void *buf)
 {
   int i, num, base;
 
-  if (!(arm_hwcap & HWCAP_VFP))
-    return;
-
-  if ((arm_hwcap & (HWCAP_VFPv3 | HWCAP_VFPv3D16)) == HWCAP_VFPv3)
+  if (regcache->tdesc == tdesc_arm_with_neon
+      || regcache->tdesc == tdesc_arm_with_vfpv3)
     num = 32;
-  else
+  else if (regcache->tdesc == tdesc_arm_with_vfpv2)
     num = 16;
+  else
+    return;
 
   base = find_regno (regcache->tdesc, "d0");
   for (i = 0; i < num; i++)
-- 
1.9.1

[PATCH 4/4] Remove global variable arm_hwcap

[Yao Qi]

After previous patch, we don't need global variable arm_hwcap.  This
patch is to remove it.

gdb/gdbserver:

2015-07-28  Yao Qi  <yao.qi@linaro.org>

	* linux-arm-low.c (arm_hwcap): Remove it.
	(arm_read_description): New local variable arm_hwcap.  Don't
	set arm_hwcap to zero.
---
 gdb/gdbserver/linux-arm-low.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/gdb/gdbserver/linux-arm-low.c b/gdb/gdbserver/linux-arm-low.c
index 02a1c08..3c5956b 100644
--- a/gdb/gdbserver/linux-arm-low.c
+++ b/gdb/gdbserver/linux-arm-low.c
@@ -117,8 +117,6 @@ struct arch_lwp_info
   CORE_ADDR stopped_data_address;
 };
 
-static unsigned long arm_hwcap;
-
 /* These are in <asm/elf.h> in current kernels.  */
 #define HWCAP_VFP       64
 #define HWCAP_IWMMXT    512
@@ -844,11 +842,11 @@ static const struct target_desc *
 arm_read_description (void)
 {
   int pid = lwpid_of (current_thread);
+  unsigned long arm_hwcap = 0;
 
   /* Query hardware watchpoint/breakpoint capabilities.  */
   arm_linux_init_hwbp_cap (pid);
 
-  arm_hwcap = 0;
   if (arm_get_hwcap (&arm_hwcap) == 0)
     return tdesc_arm;
 
@@ -875,10 +873,8 @@ arm_read_description (void)
       buf = xmalloc (32 * 8 + 4);
       if (ptrace (PTRACE_GETVFPREGS, pid, 0, buf) < 0
 	  && errno == EIO)
-	{
-	  arm_hwcap = 0;
-	  result = tdesc_arm;
-	}
+	result = tdesc_arm;
+
       free (buf);
 
       return result;
-- 
1.9.1

[PATCH 0/4] GDBserver linux-arm-low.c cleanup

[Yao Qi]

This patch series is to clean up gdbserver/linux-arm-low.c, as a
preparation for the aarch64 multi-arch debugging gdbserver patches.

All of them are tested on panda board (vfpv3) and qemu system mode
(vfpv2).

*** BLURB HERE ***

Yao Qi (4):
  Move ARM register numbers enum to arch/arm.h
  Don't use arm_regmap and arm_num_regs in arm_fill_gregset and
    arm_store_gregset
  Use regcache->tdesc instead of arm_hwcap
  Remove global variable arm_hwcap

 gdb/Makefile.in               |  2 +-
 gdb/arch/arm.h                | 61 +++++++++++++++++++++++++++++++++++++++++++
 gdb/arm-tdep.h                | 39 +--------------------------
 gdb/gdbserver/linux-arm-low.c | 56 ++++++++++++++++++++-------------------
 4 files changed, 92 insertions(+), 66 deletions(-)
 create mode 100644 gdb/arch/arm.h

-- 
1.9.1

Re: [PATCH 0/4] GDBserver linux-arm-low.c cleanup

[Yao Qi]

Yao Qi <qiyaoltc@gmail.com> writes:

> This patch series is to clean up gdbserver/linux-arm-low.c, as a
> preparation for the aarch64 multi-arch debugging gdbserver patches.
>
> All of them are tested on panda board (vfpv3) and qemu system mode
> (vfpv2).

I pushed them in.

-- 
Yao (齐尧)