Some get_last_target_status tweaks

- Make get_last_target_status arguments optional.  A following patch
  will add another argument to get_last_target_status (the event's
  target), and passing nullptr when we don't care for some piece of
  info is handier than creating dummy local variables.

- Declare nullify_last_target_wait_ptid in a header, and remove the
  local extern declaration from linux-fork.c.

gdb/ChangeLog:
2020-01-10  Pedro Alves  <palves@redhat.com>

	* break-catch-sig.c (signal_catchpoint_print_it): Don't pass a
	ptid to get_last_target_status.
	* break-catch-syscall.c (print_it_catch_syscall): Don't pass a
	ptid to get_last_target_status.
	* infcmd.c (continue_command): Don't pass a target_waitstatus to
	get_last_target_status.
	(info_program_command): Don't pass a target_waitstatus to
	get_last_target_status.
	* infrun.c (init_wait_for_inferior): Use
	nullify_last_target_wait_ptid.
	(get_last_target_status): Handle nullptr arguments.
	(nullify_last_target_wait_ptid): Clear target_last_waitstatus.
	(print_stop_event): Don't pass a ptid to get_last_target_status.
	(normal_stop): Don't pass a ptid to get_last_target_status.
	* infrun.h (get_last_target_status, set_last_target_status): Move
	comments here and update.
	(nullify_last_target_wait_ptid): Declare.
	* linux-fork.c (fork_load_infrun_state): Remove local extern
	declaration of nullify_last_target_wait_ptid.
	* linux-nat.c (get_detach_signal): Don't pass a target_waitstatus
	to get_last_target_status.

1 files changed, 2 insertions, 7 deletions

diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index aea977f..99823a8 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -851,9 +851,8 @@ continue_command (const char *args, int from_tty)
       else
 	{
 	  ptid_t last_ptid;
-	  struct target_waitstatus ws;
 
-	  get_last_target_status (&last_ptid, &ws);
+	  get_last_target_status (&last_ptid, nullptr);
 	  tp = find_thread_ptid (last_ptid);
 	}
       if (tp != NULL)
@@ -1993,11 +1992,7 @@ info_program_command (const char *args, int from_tty)
   if (non_stop)
     ptid = inferior_ptid;
   else
-    {
-      struct target_waitstatus ws;
-
-      get_last_target_status (&ptid, &ws);
-    }
+    get_last_target_status (&ptid, nullptr);
 
   if (ptid == null_ptid || ptid == minus_one_ptid)
     error (_("No selected thread."));