gdb: add interp::on_no_history method

Same as previous patches, but for no_history.

Change-Id: I06930fe7cb4082138c6c5496c5118fe4951c10da

gdb/cli/cli-interp.c

@@ -146,19 +146,10 @@ cli_interp_base::on_exited (int status)
   print_exited_reason (this->interp_ui_out (), status);
 }
 
-/* Observer for the no_history notification.  */
-
-static void
-cli_base_on_no_history ()
+void
+cli_interp_base::on_no_history ()
 {
-  SWITCH_THRU_ALL_UIS ()
-    {
-      cli_interp_base *cli = as_cli_interp_base (top_level_interpreter ());
-      if (cli == nullptr)
-	continue;
-
-      print_no_history_reason (cli->interp_ui_out ());
-    }
+  print_no_history_reason (this->interp_ui_out ());
 }
 
 /* Observer for the sync_execution_done notification.  */
@@ -370,7 +361,6 @@ _initialize_cli_interp ()
   interp_factory_register (INTERP_CONSOLE, cli_interp_factory);
 
   /* Note these all work for both the CLI and TUI interpreters.  */
-  gdb::observers::no_history.attach (cli_base_on_no_history, "cli-interp-base");
   gdb::observers::sync_execution_done.attach (cli_base_on_sync_execution_done,
 					      "cli-interp-base");
   gdb::observers::command_error.attach (cli_base_on_command_error,

gdb/cli/cli-interp.h

@@ -37,6 +37,7 @@ public:
   void on_signal_exited (gdb_signal sig) override;
   void on_normal_stop (bpstat *bs, int print_frame) override;
   void on_exited (int status) override;
+  void on_no_history () override;
 
 private:
   struct saved_output_files

gdb/infrun.c

@@ -6039,7 +6039,7 @@ handle_inferior_event (struct execution_control_state *ecs)
       if (handle_stop_requested (ecs))
 	return;
 
-      gdb::observers::no_history.notify ();
+      interps_notify_no_history ();
       stop_waiting (ecs);
       return;
     }

gdb/interps.c

@@ -416,6 +416,14 @@ interps_notify_signal_exited (gdb_signal sig)
 
 /* See interps.h.  */
 
+void
+interps_notify_no_history ()
+{
+  interps_notify (&interp::on_no_history);
+}
+
+/* See interps.h.  */
+
 void
 interps_notify_normal_stop (bpstat *bs, int print_frame)
 {

gdb/interps.h

@@ -98,6 +98,10 @@ public:
      status STATUS.  */
   virtual void on_exited (int status) {}
 
+  /* Notify the interpreter that the current inferior has stopped reverse
+     execution because there is no more history.  */
+  virtual void on_no_history () {}
+
 private:
   /* The memory for this is static, it comes from literal strings (e.g. "cli").  */
   const char *m_name;
@@ -197,6 +201,10 @@ extern void interps_notify_signal_exited (gdb_signal sig);
 /* Notify all interpreters that the current inferior has stopped normally.  */
 extern void interps_notify_normal_stop (bpstat *bs, int print_frame);
 
+/* Notify all interpreters that the current inferior has stopped reverse
+   execution because there is no more history.  */
+extern void interps_notify_no_history ();
+
 /* Notify all interpreters that the current inferior has exited normally with
    status STATUS.  */
 extern void interps_notify_exited (int status);

gdb/mi/mi-interp.c

@@ -60,8 +60,6 @@ static int mi_interp_query_hook (const char *ctlstr, va_list ap)
 static void mi_insert_notify_hooks (void);
 static void mi_remove_notify_hooks (void);
 
-static void mi_on_no_history (void);
-
 static void mi_new_thread (struct thread_info *t);
 static void mi_thread_exit (struct thread_info *t, int silent);
 static void mi_record_changed (struct inferior*, int, const char *,
@@ -497,26 +495,6 @@ mi_inferior_removed (struct inferior *inf)
     }
 }
 
-/* Return the MI interpreter, if it is active -- either because it's
-   the top-level interpreter or the interpreter executing the current
-   command.  Returns NULL if the MI interpreter is not being used.  */
-
-static struct mi_interp *
-find_mi_interp (void)
-{
-  struct mi_interp *mi;
-
-  mi = as_mi_interp (top_level_interpreter ());
-  if (mi != NULL)
-    return mi;
-
-  mi = as_mi_interp (command_interp ());
-  if (mi != NULL)
-    return mi;
-
-  return NULL;
-}
-
 /* Observers for several run control events that print why the
    inferior has stopped to both the MI event channel and to the MI
    console.  If the MI interpreter is not active, print nothing.  */
@@ -542,21 +520,11 @@ mi_interp::on_exited (int status)
   print_exited_reason (this->cli_uiout, status);
 }
 
-/* Observer for the no_history notification.  */
-
-static void
-mi_on_no_history (void)
+void
+mi_interp::on_no_history ()
 {
-  SWITCH_THRU_ALL_UIS ()
-    {
-      struct mi_interp *mi = find_mi_interp ();
-
-      if (mi == NULL)
-	continue;
-
-      print_no_history_reason (mi->mi_uiout);
-      print_no_history_reason (mi->cli_uiout);
-    }
+  print_no_history_reason (this->mi_uiout);
+  print_no_history_reason (this->cli_uiout);
 }
 
 void
@@ -1253,7 +1221,6 @@ _initialize_mi_interp ()
   interp_factory_register (INTERP_MI4, mi_interp_factory);
   interp_factory_register (INTERP_MI, mi_interp_factory);
 
-  gdb::observers::no_history.attach (mi_on_no_history, "mi-interp");
   gdb::observers::new_thread.attach (mi_new_thread, "mi-interp");
   gdb::observers::thread_exit.attach (mi_thread_exit, "mi-interp");
   gdb::observers::inferior_added.attach (mi_inferior_added, "mi-interp");

gdb/mi/mi-interp.h

@@ -46,6 +46,7 @@ public:
   void on_signal_exited (gdb_signal sig) override;
   void on_normal_stop (struct bpstat *bs, int print_frame) override;
   void on_exited (int status) override;
+  void on_no_history () override;
 
   /* MI's output channels */
   mi_console_file *out;

gdb/observable.c

@@ -34,7 +34,6 @@ bool observer_debug = false;
 
 DEFINE_OBSERVABLE (normal_stop);
 DEFINE_OBSERVABLE (signal_received);
-DEFINE_OBSERVABLE (no_history);
 DEFINE_OBSERVABLE (sync_execution_done);
 DEFINE_OBSERVABLE (command_error);
 DEFINE_OBSERVABLE (target_changed);

gdb/observable.h

@@ -57,9 +57,6 @@ extern observable<struct bpstat */* bs */, int /* print_frame */> normal_stop;
 /* The inferior was stopped by a signal.  */
 extern observable<enum gdb_signal /* siggnal */> signal_received;
 
-/* Reverse execution: target ran out of history info.  */
-extern observable<> no_history;
-
 /* A synchronous command finished.  */
 extern observable<> sync_execution_done;