gdbserver/linux-low: turn 'supports_hardware_single_step' into a method

All the linux low targets except arm define the
'supports_hardware_single_step' op to return true.  Hence, we override
the method to return true in linux_process_target, and remove the
definitions in all the linux low targets but arm.

gdbserver/ChangeLog:
2020-04-02  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>

	Remove the 'supports_hardware_single_step' linux target op and
	override the process_stratum_target's op definition in
	linux_process_target to return true.

	* linux-low.h (struct linux_target_ops): Remove the op.
	(class linux_process_target) <finish_step_over>
	<maybe_hw_step>: Declare.
	* linux-low.cc (can_hardware_single_step): Remove.
	(maybe_hw_step): Turn into...
	(linux_process_target::maybe_hw_step): ...this.
	(finish_step_over): Turn into...
	(linux_process_target::finish_step_over): ...this.
	(linux_process_target::supports_hardware_single_step): Update
	to return true.

	Update the callers below.

	(linux_process_target::single_step)
	(linux_process_target::resume_one_lwp_throw)

	* linux-arm-low.cc (class arm_target)
	<supports_hardware_single_step>: Declare.
	(arm_supports_hardware_single_step): Turn into...
	(arm_target::supports_hardware_single_step): ...this.
	(the_low_target): Remove the op field.
	* linux-x86-low.cc (x86_supports_hardware_single_step): Remove.
	(the_low_target): Remove the op field.
	* linux-aarch64-low.cc (aarch64_supports_hardware_single_step):
	Remove.
	(the_low_target): Remove the op field.
	* linux-bfin-low.cc (bfin_supports_hardware_single_step): Remove.
	(the_low_target): Remove the op field.
	* linux-crisv32-low.cc (cris_supports_hardware_single_step): Remove.
	(the_low_target): Remove the op field.
	* linux-m32r-low.cc (m32r_supports_hardware_single_step): Remove.
	(the_low_target): Remove the op field.
	* linux-m68k-low.cc (m68k_supports_hardware_single_step): Remove.
	(the_low_target): Remove the op field.
	* linux-ppc-low.cc (ppc_supports_hardware_single_step): Remove.
	(the_low_target): Remove the op field.
	* linux-s390-low.cc (s390_supports_hardware_single_step): Remove.
	(the_low_target): Remove the op field.
	* linux-sh-low.cc (sh_supports_hardware_single_step): Remove.
	(the_low_target): Remove the op field.
	* linux-tic6x-low.cc (tic6x_supports_hardware_single_step): Remove.
	(the_low_target): Remove the op field.
	* linux-tile-low.cc (tile_supports_hardware_single_step): Remove.
	(the_low_target): Remove the op field.
	* linux-xtensa-low.cc (xtensa_supports_hardware_single_step):
	Remove.
	(the_low_target): Remove the op field.

1 files changed, 9 insertions, 3 deletions

diff --git a/gdbserver/linux-low.h b/gdbserver/linux-low.h
index 86a563a..0182be1 100644
--- a/gdbserver/linux-low.h
+++ b/gdbserver/linux-low.h
@@ -131,9 +131,6 @@ struct lwp_info;
 
 struct linux_target_ops
 {
-  /* See target.h.  */
-  int (*supports_hardware_single_step) (void);
-
   /* Fill *SYSNO with the syscall nr trapped.  Only to be called when
      inferior is stopped due to SYSCALL_SIGTRAP.  */
   void (*get_syscall_trapinfo) (struct regcache *regcache, int *sysno);
@@ -401,6 +398,12 @@ private:
      events.  */
   void complete_ongoing_step_over ();
 
+  /* Finish a step-over.  Reinsert the breakpoint we had uninserted in
+     start_step_over, if still there, and delete any single-step
+     breakpoints we've set, on non hardware single-step targets.
+     Return true if step over finished.  */
+  bool finish_step_over (lwp_info *lwp);
+
   /* When we finish a step-over, set threads running again.  If there's
      another thread that may need a step-over, now's the time to start
      it.  Eventually, we'll move all threads past their breakpoints.  */
@@ -519,6 +522,9 @@ private:
      or can't single step.  */
   int single_step (lwp_info* lwp);
 
+  /* Return true if THREAD is doing hardware single step.  */
+  bool maybe_hw_step (thread_info *thread);
+
   /* Install breakpoints for software single stepping.  */
   void install_software_single_step_breakpoints (lwp_info *lwp);