+/* "Observer mode" is somewhat like a more extreme version of
+ non-stop, in which all GDB operations that might affect the
+ target's execution have been disabled. */
+
+static int non_stop_1 = 0;
+
+int observer_mode = 0;
+static int observer_mode_1 = 0;
+
+static void
+set_observer_mode (char *args, int from_tty,
+ struct cmd_list_element *c)
+{
+ extern int pagination_enabled;
+
+ if (target_has_execution)
+ {
+ observer_mode_1 = observer_mode;
+ error (_("Cannot change this setting while the inferior is running."));
+ }
+
+ observer_mode = observer_mode_1;
+
+ may_write_registers = !observer_mode;
+ may_write_memory = !observer_mode;
+ may_insert_breakpoints = !observer_mode;
+ may_insert_tracepoints = !observer_mode;
+ /* We can insert fast tracepoints in or out of observer mode,
+ but enable them if we're going into this mode. */
+ if (observer_mode)
+ may_insert_fast_tracepoints = 1;
+ may_stop = !observer_mode;
+ update_target_permissions ();
+
+ /* Going *into* observer mode we must force non-stop, then
+ going out we leave it that way. */
+ if (observer_mode)
+ {
+ target_async_permitted = 1;
+ pagination_enabled = 0;
+ non_stop = non_stop_1 = 1;
+ }
+
+ if (from_tty)
+ printf_filtered (_("Observer mode is now %s.\n"),
+ (observer_mode ? "on" : "off"));
+}
+
+static void
+show_observer_mode (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("Observer mode is %s.\n"), value);
+}
+
+/* This updates the value of observer mode based on changes in
+ permissions. Note that we are deliberately ignoring the values of
+ may-write-registers and may-write-memory, since the user may have
+ reason to enable these during a session, for instance to turn on a
+ debugging-related global. */
+
+void
+update_observer_mode (void)
+{
+ int newval;
+
+ newval = (!may_insert_breakpoints
+ && !may_insert_tracepoints
+ && may_insert_fast_tracepoints
+ && !may_stop
+ && non_stop);
+
+ /* Let the user know if things change. */
+ if (newval != observer_mode)
+ printf_filtered (_("Observer mode is now %s.\n"),
+ (newval ? "on" : "off"));
+
+ observer_mode = observer_mode_1 = newval;
+}