record: signal a record goto stop to front-ends

The "record goto" command does not indicate the stop to front-ends.  Instead,
it prints the new location directly.

Add a function to signal a normal stop to observers and have them print the new
location.  This function temporarily switches to the stopped thread.

We use the TARGET_WAITKIND_NO_RESUMED wait status for this purpose.  This should
result in a stop notification without giving a stop reason.  We could also
invent a new wait status but this doesn't seem necessary at this point.

Signed-off-by: Markus Metzger  <markus.t.metzger@intel.com>

gdb/
	* record.h (record_signal_goto_stop): New.
	* record.c (record_signal_goto_stop): New.

Change-Id: I0b196be68779f9e81abca78df5bc39e917023581

gdb/record.c

@@ -342,6 +342,27 @@ cmd_record_save (char *args, int from_tty)
 
 /* See record.h.  */
 
+void
+record_signal_goto_stop (struct thread_info *tp)
+{
+  struct target_waitstatus ws;
+  struct cleanup *cleanup;
+
+  clear_proceed_status_thread (tp);
+
+  cleanup = make_cleanup_restore_current_thread ();
+  switch_to_thread (tp->ptid);
+
+  ws.kind = TARGET_WAITKIND_NO_RESUMED;
+  set_last_target_status (tp->ptid, ws);
+
+  observer_notify_normal_stop (NULL, 1);
+
+  do_cleanups (cleanup);
+}
+
+/* See record.h.  */
+
 void
 record_goto (const char *arg)
 {

gdb/record.h

@@ -91,4 +91,7 @@ extern struct target_ops *find_record_target (void);
    it does anything.  */
 extern void record_preopen (void);
 
+/* Signal a record-goto stop of TP to front-ends.  */
+extern void record_signal_goto_stop (struct thread_info *tp);
+
 #endif /* _RECORD_H_ */