gdb: add breakpoint::first_loc methods

Add convenience first_loc methods to struct breakpoint (const and
non-const overloads).  A subsequent patch changes the list of locations
to be an intrusive_list and makes the actual list private, so these
spots would need to change from:

    b->loc

to something ugly like:

    *b->locations ().begin ()

That would make the code much heavier and not readable.  There is a
surprisingly big number of places that access the first location of
breakpoints.  Whether this is correct, or these spots fail to consider
the possibility of multi-location breakpoints, I don't know.  But
anyhow, I think that using this instead:

 b->first_loc ()

conveys the intention better than the other two forms.

Change-Id: Ibbefe3e4ca6cdfe570351fe7e2725f2ce11d1e95
Reviewed-By: Andrew Burgess <aburgess@redhat.com>

1 files changed, 6 insertions, 5 deletions

diff --git a/gdb/infrun.c b/gdb/infrun.c
index efe2c00..a9e2a24 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -950,14 +950,14 @@ follow_inferior_reset_breakpoints (void)
   if (tp->control.step_resume_breakpoint)
     {
       breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
-      tp->control.step_resume_breakpoint->loc->enabled = 1;
+      tp->control.step_resume_breakpoint->first_loc ().enabled = 1;
     }
 
   /* Treat exception_resume breakpoints like step_resume breakpoints.  */
   if (tp->control.exception_resume_breakpoint)
     {
       breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
-      tp->control.exception_resume_breakpoint->loc->enabled = 1;
+      tp->control.exception_resume_breakpoint->first_loc ().enabled = 1;
     }
 
   /* Reinsert all breakpoints in the child.  The user may have set
@@ -2551,7 +2551,8 @@ resume_1 (enum gdb_signal sig)
 		 user breakpoints at PC to trigger (again) when this
 		 hits.  */
 	      insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
-	      gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
+	      gdb_assert (tp->control.step_resume_breakpoint->first_loc ()
+			  .permanent);
 
 	      tp->step_after_step_resume_breakpoint = step;
 	    }
@@ -7008,9 +7009,9 @@ process_event_stop_test (struct execution_control_state *ecs)
 	= ecs->event_thread->control.step_resume_breakpoint;
 
       if (sr_bp != nullptr
-	  && sr_bp->loc->permanent
+	  && sr_bp->first_loc ().permanent
 	  && sr_bp->type == bp_hp_step_resume
-	  && sr_bp->loc->address == ecs->event_thread->prev_pc)
+	  && sr_bp->first_loc ().address == ecs->event_thread->prev_pc)
 	{
 	  infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
 	  delete_step_resume_breakpoint (ecs->event_thread);