Add the target_ops needed for software breakpoints in GDBServer.

This patch is in preparation for software breakpoints on ARM linux.  It
refactors breakpoint and breakpoint_len into breakpoint_kind_from_pc and
sw_breakpoint_from kind to prepare the case where we have multiple types of
breakpoints.

Kind is the type of breakpoint (hardware or software) to be inserted, usually it
is the lenght of the software breakpoint but can be something else depending on
the target.

This patch introduces the linux_target_ops breakpoint_kind_from_pc and
sw_breakpoint_from_kind.

breakpoint_kind_from_pc returns the breakpoint kind and adjusts the PC to the
real memory location in case a flag was present in the PC. E.g the instruction
mode on ARM.

sw_breakpoint_from_kind returns the software breakpoint for this kind as a
string of bytes, the length of the breakpoint is adjusted for the breakpoint's
size in memory.

For targets that have only one kind of breakpoint, the default value 0 is
returned by linux_breakpoint_kind_from_pc so that not all targets need to
implement the breakpoint_kind_from_pc operation.

No regressions, tested on Ubuntu 14.04 on ARMv7 and x86
With gdbserver-{native,extended} / { -marm -mthumb }

Also since the target_ops have been changed compilation was tested on
affected archs namely : aarch64, arm, bfin, cris, crisv32, m32r,
m68k, mips, nios2, ppc, s390, sparc, tic6x, tile, x86, steins.

Not tested : sh

gdb/gdbserver/ChangeLog:

	* linux-aarch64-low.c (aarch64_sw_breakpoint_from_kind): New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.
	* linux-arm-low.c (arm_breakpoint_kind_from_pc): New function.
	(arm_sw_breakpoint_from_kind): New function.
	* linux-bfin-low.c (bfin_sw_breakpoint_from_kind): New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.
	* linux-cris-low.c (cris_sw_breakpoint_from_kind): New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.
	* linux-crisv32-low.c (cris_sw_breakpoint_from_kind): New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.
	* linux-low.c (linux_wait_1): Call breakpoint_kind_from_pc
	and sw_breakpoint_from_kind to increment the pc.
	(linux_breakpoint_kind_from_pc): New function.
	(linux_sw_breakpoint_from_kind): New function.
	(struct target_ops) <sw_breakpoint_from_kind>: Initialize field.
	(initialize_low): Call breakpoint_kind_from_pc and
	sw_breakpoint_from_kind to replace breakpoint_data/len.
	* linux-low.h (struct linux_target_ops) <breakpoint_kind_from_pc>:
	New field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Likewise.
	* linux-m32r-low.c (m32r_sw_breakpoint_from_kind): New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.
	* linux-m68k-low.c (m68k_sw_breakpoint_from_kind): New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.
	* linux-mips-low.c (mips_sw_breakpoint_from_kind): New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.
	* linux-nios2-low.c (nios2_sw_breakpoint_from_kind): New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.
	* linux-ppc-low.c (ppc_sw_breakpoint_from_kind): New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.
	* linux-s390-low.c (s390_sw_breakpoint_from_kind): New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.
	* linux-sh-low.c (sh_sw_breakpoint_from_kind): New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.
	* linux-sparc-low.c (sparc_sw_breakpoint_from_kind): New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.
	* linux-tic6x-low.c (tic6x_sw_breakpoint_from_kind): New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.
	* linux-tile-low.c (tile_sw_breakpoint_from_kind): New function.
	* linux-x86-low.c (x86_sw_breakpoint_from_kind): New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.
	* linux-xtensa-low.c (xtensa_sw_breakpoint_from_kind) New function.
	(struct linux_target_ops) <breakpoint>: Remove.
	(struct linux_target_ops) <breakpoint_len>: Remove.
	(struct linux_target_ops) <breakpoint_kind_from_pc>: Initialize field.
	(struct linux_target_ops) <sw_breakpoint_from_kind>: Initialize field.

1 files changed, 12 insertions, 3 deletions

diff --git a/gdb/gdbserver/linux-xtensa-low.c b/gdb/gdbserver/linux-xtensa-low.c
index debe467..fa6f418 100644
--- a/gdb/gdbserver/linux-xtensa-low.c
+++ b/gdb/gdbserver/linux-xtensa-low.c
@@ -151,9 +151,18 @@ static struct regset_info xtensa_regsets[] = {
 #define XTENSA_BREAKPOINT {0x2d,0xf0}
 #endif
 
-static const unsigned char xtensa_breakpoint[] = XTENSA_BREAKPOINT;
+static const gdb_byte xtensa_breakpoint[] = XTENSA_BREAKPOINT;
 #define xtensa_breakpoint_len 2
 
+/* Implementation of linux_target_ops method "sw_breakpoint_from_kind".  */
+
+static const gdb_byte *
+xtensa_sw_breakpoint_from_kind (int kind, int *size)
+{
+  *size = xtensa_breakpoint_len;
+  return xtensa_breakpoint;
+}
+
 static CORE_ADDR
 xtensa_get_pc (struct regcache *regcache)
 {
@@ -234,8 +243,8 @@ struct linux_target_ops the_low_target = {
   NULL, /* fetch_register */
   xtensa_get_pc,
   xtensa_set_pc,
-  xtensa_breakpoint,
-  xtensa_breakpoint_len,
+  NULL, /* breakpoint_kind_from_pc */
+  xtensa_sw_breakpoint_from_kind,
   NULL,
   0,
   xtensa_breakpoint_at,