Make single-step breakpoints be per-thread

This patch finally makes each thread have its own set of single-step
breakpoints.  This paves the way to have multiple threads software
single-stepping, though this patch doesn't flip that switch on yet.
That'll be done on a subsequent patch.

gdb/
2014-10-15  Pedro Alves  <palves@redhat.com>

	* breakpoint.c (single_step_breakpoints): Delete global.
	(insert_single_step_breakpoint): Adjust to store the breakpoint
	pointer in the current thread.
	(single_step_breakpoints_inserted, remove_single_step_breakpoints)
	(cancel_single_step_breakpoints): Delete functions.
	(breakpoint_has_location_inserted_here): Make extern.
	(single_step_breakpoint_inserted_here_p): Adjust to walk the
	breakpoint list.
	* breakpoint.h (breakpoint_has_location_inserted_here): New
	declaration.
	(single_step_breakpoints_inserted, remove_single_step_breakpoints)
	(cancel_single_step_breakpoints): Remove declarations.
	* gdbthread.h (struct thread_control_state)
	<single_step_breakpoints>: New field.
	(delete_single_step_breakpoints)
	(thread_has_single_step_breakpoints_set)
	(thread_has_single_step_breakpoint_here): New declarations.
	* infrun.c (follow_exec): Also clear the single-step breakpoints.
	(singlestep_breakpoints_inserted_p, singlestep_ptid)
	(singlestep_pc): Delete globals.
	(infrun_thread_ptid_changed): Remove references to removed
	globals.
	(resume_cleanups): Delete the current thread's single-step
	breakpoints.
	(maybe_software_singlestep): Remove references to removed globals.
	(resume): Adjust to use thread_has_single_step_breakpoints_set and
	delete_single_step_breakpoints.
	(init_wait_for_inferior): Remove references to removed globals.
	(delete_thread_infrun_breakpoints): Delete the thread's
	single-step breakpoints too.
	(delete_just_stopped_threads_infrun_breakpoints): Don't delete
	single-step breakpoints here.
	(delete_stopped_threads_single_step_breakpoints): New function.
	(adjust_pc_after_break): Adjust to use
	thread_has_single_step_breakpoints_set.
	(handle_inferior_event): Remove references to removed globals.
	Use delete_stopped_threads_single_step_breakpoints.
	(handle_signal_stop): Adjust to per-thread single-step
	breakpoints.  Swap test order to do cheaper tests first.
	(switch_back_to_stepped_thread): Extend debug output.  Remove
	references to removed globals.
	* record-full.c (record_full_wait_1): Adjust to per-thread
	single-step breakpoints.
	* thread.c (delete_single_step_breakpoints)
	(thread_has_single_step_breakpoints_set)
	(thread_has_single_step_breakpoint_here): New functions.
	(clear_thread_inferior_resources): Also delete the thread's
	single-step breakpoints.

1 files changed, 31 insertions, 0 deletions

diff --git a/gdb/thread.c b/gdb/thread.c
index 82c6760..5a1d2e3 100644
--- a/gdb/thread.c
+++ b/gdb/thread.c
@@ -117,6 +117,15 @@ delete_exception_resume_breakpoint (struct thread_info *tp)
     delete_thread_breakpoint (&tp->control.exception_resume_breakpoint);
 }
 
+/* See gdbthread.h.  */
+
+void
+delete_single_step_breakpoints (struct thread_info *tp)
+{
+  if (tp != NULL)
+    delete_thread_breakpoint (&tp->control.single_step_breakpoints);
+}
+
 /* Delete the breakpoint pointed at by BP_P at the next stop, if
    there's one.  */
 
@@ -130,6 +139,27 @@ delete_at_next_stop (struct breakpoint **bp)
     }
 }
 
+/* See gdbthread.h.  */
+
+int
+thread_has_single_step_breakpoints_set (struct thread_info *tp)
+{
+  return tp->control.single_step_breakpoints != NULL;
+}
+
+/* See gdbthread.h.  */
+
+int
+thread_has_single_step_breakpoint_here (struct thread_info *tp,
+					struct address_space *aspace,
+					CORE_ADDR addr)
+{
+  struct breakpoint *ss_bps = tp->control.single_step_breakpoints;
+
+  return (ss_bps != NULL
+	  && breakpoint_has_location_inserted_here (ss_bps, aspace, addr));
+}
+
 static void
 clear_thread_inferior_resources (struct thread_info *tp)
 {
@@ -139,6 +169,7 @@ clear_thread_inferior_resources (struct thread_info *tp)
      be stopped at the moment.  */
   delete_at_next_stop (&tp->control.step_resume_breakpoint);
   delete_at_next_stop (&tp->control.exception_resume_breakpoint);
+  delete_at_next_stop (&tp->control.single_step_breakpoints);
 
   delete_longjmp_breakpoint_at_next_stop (tp->num);