[10/30] gdb: add interp::on_user_selected_context_changed method

diff --git a/gdb/cli/cli-interp.c b/gdb/cli/cli-interp.c
index ffb40729fc61..6a175f7baa13 100644
--- a/gdb/cli/cli-interp.c
+++ b/gdb/cli/cli-interp.c
@@ -67,15 +67,6 @@  cli_interp::cli_interp (const char *name)
 /* Suppress notification struct.  */
 struct cli_suppress_notification cli_suppress_notification;
 
-/* Returns the INTERP's data cast as cli_interp_base if INTERP is a
-   console-like interpreter, and returns NULL otherwise.  */
-
-static cli_interp_base *
-as_cli_interp_base (interp *interp)
-{
-  return dynamic_cast<cli_interp_base *> (interp);
-}
-
 /* See cli-interp.h.
 
    Breakpoint hits should always be mirrored to a console.  Deciding
@@ -164,10 +155,8 @@  cli_interp_base::on_command_error ()
   display_gdb_prompt (NULL);
 }
 
-/* Observer for the user_selected_context_changed notification.  */
-
-static void
-cli_base_on_user_selected_context_changed (user_selected_what selection)
+void
+cli_interp_base::on_user_selected_context_changed (user_selected_what selection)
 {
   /* This event is suppressed.  */
   if (cli_suppress_notification.user_selected_context)
@@ -175,19 +164,12 @@  cli_base_on_user_selected_context_changed (user_selected_what selection)
 
   thread_info *tp = inferior_ptid != null_ptid ? inferior_thread () : nullptr;
 
-  SWITCH_THRU_ALL_UIS ()
-    {
-      cli_interp_base *cli = as_cli_interp_base (top_level_interpreter ());
-      if (cli == nullptr)
-	continue;
-
-      if (selection & USER_SELECTED_INFERIOR)
-	print_selected_inferior (cli->interp_ui_out ());
+  if (selection & USER_SELECTED_INFERIOR)
+    print_selected_inferior (this->interp_ui_out ());
 
-      if (tp != nullptr
-	  && ((selection & (USER_SELECTED_THREAD | USER_SELECTED_FRAME))))
-	print_selected_thread_frame (cli->interp_ui_out (), selection);
-    }
+  if (tp != nullptr
+      && ((selection & (USER_SELECTED_THREAD | USER_SELECTED_FRAME))))
+    print_selected_thread_frame (this->interp_ui_out (), selection);
 }
 
 /* pre_command_loop implementation.  */
@@ -347,8 +329,4 @@  void
 _initialize_cli_interp ()
 {
   interp_factory_register (INTERP_CONSOLE, cli_interp_factory);
-
-  /* Note these all work for both the CLI and TUI interpreters.  */
-  gdb::observers::user_selected_context_changed.attach
-    (cli_base_on_user_selected_context_changed, "cli-interp-base");
 }
diff --git a/gdb/cli/cli-interp.h b/gdb/cli/cli-interp.h
index 5020b2bc6ef4..a1a20b678942 100644
--- a/gdb/cli/cli-interp.h
+++ b/gdb/cli/cli-interp.h
@@ -40,6 +40,7 @@  class cli_interp_base : public interp
   void on_no_history () override;
   void on_sync_execution_done () override;
   void on_command_error () override;
+  void on_user_selected_context_changed (user_selected_what selection) override;
 
 private:
   struct saved_output_files
diff --git a/gdb/inferior.c b/gdb/inferior.c
index fd451c87e709..8962b6401e34 100644
--- a/gdb/inferior.c
+++ b/gdb/inferior.c
@@ -745,7 +745,7 @@  inferior_command (const char *args, int from_tty)
 	      switch_to_thread (tp);
 	    }
 
-	  gdb::observers::user_selected_context_changed.notify
+	  notify_user_selected_context_changed
 	    (USER_SELECTED_INFERIOR
 	     | USER_SELECTED_THREAD
 	     | USER_SELECTED_FRAME);
@@ -754,7 +754,7 @@  inferior_command (const char *args, int from_tty)
 	{
 	  switch_to_inferior_no_thread (inf);
 
-	  gdb::observers::user_selected_context_changed.notify
+	  notify_user_selected_context_changed
 	    (USER_SELECTED_INFERIOR);
 	}
     }
diff --git a/gdb/infrun.c b/gdb/infrun.c
index 8d648cf04f0a..aa2d34aa6b35 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -6282,6 +6282,14 @@  notify_normal_stop (bpstat *bs, int print_frame)
   gdb::observers::normal_stop.notify (bs, print_frame);
 }
 
+/* See infrun.h.  */
+
+void notify_user_selected_context_changed (user_selected_what selection)
+{
+  interps_notify_user_selected_context_changed (selection);
+  gdb::observers::user_selected_context_changed.notify (selection);
+}
+
 /* Come here when the program has stopped with a signal.  */
 
 static void
diff --git a/gdb/infrun.h b/gdb/infrun.h
index cbafc3ea4407..a343d27f72de 100644
--- a/gdb/infrun.h
+++ b/gdb/infrun.h
@@ -218,6 +218,9 @@  extern void notify_signal_received (gdb_signal sig);
    normally.  */
 extern void notify_normal_stop (bpstat *bs, int print_frame);
 
+/* Notify interpreters and observers that the user focus has changed.  */
+extern void notify_user_selected_context_changed (user_selected_what selection);
+
 /* Several print_*_reason helper functions to print why the inferior
    has stopped to the passed in UIOUT.  */
 
diff --git a/gdb/interps.c b/gdb/interps.c
index 885bfc36ec70..55abcb3c6e40 100644
--- a/gdb/interps.c
+++ b/gdb/interps.c
@@ -438,6 +438,14 @@  interps_notify_exited (int status)
   interps_notify (&interp::on_exited, status);
 }
 
+/* See interps.h.  */
+
+void
+interps_notify_user_selected_context_changed (user_selected_what selection)
+{
+  interps_notify (&interp::on_user_selected_context_changed, selection);
+}
+
 /* This just adds the "interpreter-exec" command.  */
 void _initialize_interpreter ();
 void
diff --git a/gdb/interps.h b/gdb/interps.h
index 53d951b8d637..4706c9bb63e7 100644
--- a/gdb/interps.h
+++ b/gdb/interps.h
@@ -110,6 +110,10 @@  class interp : public intrusive_list_node<interp>
      command on this interpreter.  */
   virtual void on_command_error () {}
 
+  /* Notify the interpreter that the user focus has changed.  */
+  virtual void on_user_selected_context_changed (user_selected_what selection)
+    {}
+
 private:
   /* The memory for this is static, it comes from literal strings (e.g. "cli").  */
   const char *m_name;
@@ -217,6 +221,10 @@  extern void interps_notify_no_history ();
    status STATUS.  */
 extern void interps_notify_exited (int status);
 
+/* Notify all interpreters that the user focus has changed.  */
+extern void interps_notify_user_selected_context_changed
+  (user_selected_what selection);
+
 /* well-known interpreters */
 #define INTERP_CONSOLE		"console"
 #define INTERP_MI2             "mi2"
diff --git a/gdb/mi/mi-interp.c b/gdb/mi/mi-interp.c
index 45160571ce98..ab8c3efbb128 100644
--- a/gdb/mi/mi-interp.c
+++ b/gdb/mi/mi-interp.c
@@ -1086,60 +1086,40 @@  mi_memory_changed (struct inferior *inferior, CORE_ADDR memaddr,
     }
 }
 
-/* Emit an event when the selection context (inferior, thread, frame)
-   changed.  */
-
-static void
-mi_user_selected_context_changed (user_selected_what selection)
+void
+mi_interp::on_user_selected_context_changed (user_selected_what selection)
 {
-  struct thread_info *tp;
-
   /* Don't send an event if we're responding to an MI command.  */
   if (mi_suppress_notification.user_selected_context)
     return;
 
-  if (inferior_ptid != null_ptid)
-    tp = inferior_thread ();
-  else
-    tp = NULL;
+  thread_info *tp = inferior_ptid != null_ptid ? inferior_thread () : nullptr;
+  ui_out *mi_uiout = this->interp_ui_out ();
+  ui_out_redirect_pop redirect_popper (mi_uiout, this->event_channel);
 
-  SWITCH_THRU_ALL_UIS ()
-    {
-      struct mi_interp *mi = as_mi_interp (top_level_interpreter ());
-      struct ui_out *mi_uiout;
+  target_terminal::scoped_restore_terminal_state term_state;
+  target_terminal::ours_for_output ();
 
-      if (mi == NULL)
-	continue;
+  if (selection & USER_SELECTED_INFERIOR)
+    print_selected_inferior (this->cli_uiout);
 
-      mi_uiout = top_level_interpreter ()->interp_ui_out ();
-
-      ui_out_redirect_pop redirect_popper (mi_uiout, mi->event_channel);
-
-      target_terminal::scoped_restore_terminal_state term_state;
-      target_terminal::ours_for_output ();
+  if (tp != NULL
+      && (selection & (USER_SELECTED_THREAD | USER_SELECTED_FRAME)))
+    {
+      print_selected_thread_frame (this->cli_uiout, selection);
 
-      if (selection & USER_SELECTED_INFERIOR)
-	print_selected_inferior (mi->cli_uiout);
+      gdb_printf (this->event_channel, "thread-selected,id=\"%d\"",
+		  tp->global_num);
 
-      if (tp != NULL
-	  && (selection & (USER_SELECTED_THREAD | USER_SELECTED_FRAME)))
+      if (tp->state != THREAD_RUNNING)
 	{
-	  print_selected_thread_frame (mi->cli_uiout, selection);
-
-	  gdb_printf (mi->event_channel,
-		      "thread-selected,id=\"%d\"",
-		      tp->global_num);
-
-	  if (tp->state != THREAD_RUNNING)
-	    {
-	      if (has_stack_frames ())
-		print_stack_frame_to_uiout (mi_uiout, get_selected_frame (NULL),
-					    1, SRC_AND_LOC, 1);
-	    }
+	  if (has_stack_frames ())
+	    print_stack_frame_to_uiout (mi_uiout, get_selected_frame (NULL),
+					1, SRC_AND_LOC, 1);
 	}
-
-      gdb_flush (mi->event_channel);
     }
+
+  gdb_flush (this->event_channel);
 }
 
 ui_out *
@@ -1233,6 +1213,4 @@  _initialize_mi_interp ()
   gdb::observers::command_param_changed.attach (mi_command_param_changed,
 						"mi-interp");
   gdb::observers::memory_changed.attach (mi_memory_changed, "mi-interp");
-  gdb::observers::user_selected_context_changed.attach
-    (mi_user_selected_context_changed, "mi-interp");
 }
diff --git a/gdb/mi/mi-interp.h b/gdb/mi/mi-interp.h
index 08edaceb99cd..430c61dbbf0a 100644
--- a/gdb/mi/mi-interp.h
+++ b/gdb/mi/mi-interp.h
@@ -49,6 +49,7 @@  class mi_interp final : public interp
   void on_no_history () override;
   void on_sync_execution_done () override;
   void on_command_error () override;
+  void on_user_selected_context_changed (user_selected_what selection) override;
 
   /* MI's output channels */
   mi_console_file *out;
diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c
index 1be5d3becfcf..29bd236ef711 100644
--- a/gdb/mi/mi-main.c
+++ b/gdb/mi/mi-main.c
@@ -2107,7 +2107,7 @@  mi_cmd_execute (struct mi_parse *parse)
 
   if (!parse->cmd->preserve_user_selected_context ()
       && current_user_selected_context.has_changed ())
-    gdb::observers::user_selected_context_changed.notify
+    interps_notify_user_selected_context_changed
       (USER_SELECTED_THREAD | USER_SELECTED_FRAME);
 }
 
diff --git a/gdb/stack.c b/gdb/stack.c
index b1b25aa1c7e1..474f1ce5b879 100644
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -1837,7 +1837,7 @@  select_frame_command_core (frame_info_ptr fi, bool ignored)
   frame_info_ptr prev_frame = get_selected_frame ();
   select_frame (fi);
   if (get_selected_frame () != prev_frame)
-    gdb::observers::user_selected_context_changed.notify (USER_SELECTED_FRAME);
+    notify_user_selected_context_changed (USER_SELECTED_FRAME);
 }
 
 /* The core of all the "frame" sub-commands.  Select frame FI, and if this
@@ -1850,7 +1850,7 @@  frame_command_core (frame_info_ptr fi, bool ignored)
   frame_info_ptr prev_frame = get_selected_frame ();
   select_frame (fi);
   if (get_selected_frame () != prev_frame)
-    gdb::observers::user_selected_context_changed.notify (USER_SELECTED_FRAME);
+    notify_user_selected_context_changed (USER_SELECTED_FRAME);
   else
     print_selected_thread_frame (current_uiout, USER_SELECTED_FRAME);
 }
@@ -2650,7 +2650,7 @@  static void
 up_command (const char *count_exp, int from_tty)
 {
   up_silently_base (count_exp);
-  gdb::observers::user_selected_context_changed.notify (USER_SELECTED_FRAME);
+  notify_user_selected_context_changed (USER_SELECTED_FRAME);
 }
 
 /* Select the frame down one or COUNT_EXP stack levels from the previously
@@ -2689,7 +2689,7 @@  static void
 down_command (const char *count_exp, int from_tty)
 {
   down_silently_base (count_exp);
-  gdb::observers::user_selected_context_changed.notify (USER_SELECTED_FRAME);
+  notify_user_selected_context_changed (USER_SELECTED_FRAME);
 }
 
 void
diff --git a/gdb/thread.c b/gdb/thread.c
index e9432f945e09..13db9f8747ea 100644
--- a/gdb/thread.c
+++ b/gdb/thread.c
@@ -1846,10 +1846,8 @@  thread_command (const char *tidstr, int from_tty)
 				       | USER_SELECTED_FRAME);
 	}
       else
-	{
-	  gdb::observers::user_selected_context_changed.notify
-	    (USER_SELECTED_THREAD | USER_SELECTED_FRAME);
-	}
+	notify_user_selected_context_changed
+	  (USER_SELECTED_THREAD | USER_SELECTED_FRAME);
     }
 }