gdb/

* cli/cli-decode.c (set_cmd_prefix): New.
	(lookup_cmd_for_prefixlist): New.
	(add_prefix_cmd): Call set_cmd_prefix and update field 'prefix'
	of each cmd_list_element in *prefixlist.
	(add_setshow_cmd_full): set_cmd_prefix.
	(add_alias_cmd): Likewise.
	* cli/cli-decode.h (struct cmd_list_element) <prefix>: New field.
	Declare 'auto_boolean_enums'.
	* cli/cli-setshow.c: Include "observer.h".
	(notify_command_param_changed_p): New.
	(add_setshow_auto_boolean_cmd): Move auto_boolean_enums out.
	Remove 'static'.
	(do_setshow_command): Split it to ...
	(do_set_command, do_show_command): ... them.  New.
	(do_set_command): Call observer_notify_command_param_changed if
	notify_command_param_changed_p returns true.
	(cmd_show_list): Caller update.
	* auto-load.c (set_auto_load_cmd): Likewise.
	* remote.c (show_remote_cmd): Likewise.
	* cli/cli-setshow.h: Update declarations.
	* top.c (execute_command): Call do_set_command and do_show_command.

	* NEWS: Mention new MI notification.
	* mi/mi-interp.c: Declare mi_command_param_changed.
	(mi_interpreter_init): Attach mi_command_param_changed to
	observer command_param_changed.
	(mi_command_param_changed): New.
	Remove mi_suppress_breakpoint_notifications.
	Define global variable mi_suppress_notification.
	(mi_breakpoint_created): Update.
	(mi_breakpoint_deleted): Likewise.
	(mi_breakpoint_modified): Likewise.
	* mi/mi-main.c (mi_cmd_execute): Likewise.  Check command
	'gdb-set' and set mi_suppress_notification.
	* mi/mi-main.h: (mi_suppress_notification): New struct.

gdb/doc/

	* observer.texi: New observer command_param_changed.
	* gdb.texinfo (GDB/MI Async Records): Doc for '=cmd-param-changed'.

gdb/testsuite/

	* gdb.mi/mi-cmd-param-changed.exp: New.
	* gdb.mi/mi-cli.exp: Update for MI notification "=cmd-param-changed".
	* gdb.mi/mi-var-rtti.exp, gdb.mi/mi2-cli.exp: Likewise.
	* gdb.mi/mi2-prompt.exp: Likewise.

gdb/cli/cli-decode.c

@@ -52,6 +52,53 @@ static struct cmd_list_element *find_cmd (char *command,
 
 static void help_all (struct ui_file *stream);
 
+/* Look up a command whose 'prefixlist' is KEY.  Return the command if found,
+   otherwise return NULL.  */
+
+static struct cmd_list_element *
+lookup_cmd_for_prefixlist (struct cmd_list_element **key,
+			   struct cmd_list_element *list)
+{
+  struct cmd_list_element *p = NULL;
+
+  for (p = list; p != NULL; p = p->next)
+    {
+      struct cmd_list_element *q;
+
+      if (p->prefixlist == NULL)
+	continue;
+      else if (p->prefixlist == key)
+	return p;
+
+      q = lookup_cmd_for_prefixlist (key, *(p->prefixlist));
+      if (q != NULL)
+	return q;
+    }
+
+  return NULL;
+}
+
+static void
+set_cmd_prefix (struct cmd_list_element *c, struct cmd_list_element **list)
+{
+  struct cmd_list_element *p;
+
+  /* Check to see if *LIST contains any element other than C.  */
+  for (p = *list; p != NULL; p = p->next)
+    if (p != c)
+      break;
+
+  if (p == NULL)
+    {
+      /* *SET_LIST only contains SET.  */
+      p = lookup_cmd_for_prefixlist (list, setlist);
+
+      c->prefix = p ? (p->cmd_pointer ? p->cmd_pointer : p) : p;
+    }
+  else
+    c->prefix = p->prefix;
+}
+
 static void
 print_help_for_command (struct cmd_list_element *c, char *prefix, int recurse,
 			struct ui_file *stream);
@@ -193,6 +240,7 @@ add_cmd (char *name, enum command_class class, void (*fun) (char *, int),
   c->prefixlist = NULL;
   c->prefixname = NULL;
   c->allow_unknown = 0;
+  c->prefix = NULL;
   c->abbrev_flag = 0;
   set_cmd_completer (c, make_symbol_completion_list_fn);
   c->destroyer = NULL;
@@ -268,6 +316,8 @@ add_alias_cmd (char *name, char *oldname, enum command_class class,
   c->cmd_pointer = old;
   c->alias_chain = old->aliases;
   old->aliases = c;
+
+  set_cmd_prefix (c, list);
   return c;
 }
 
@@ -284,10 +334,21 @@ add_prefix_cmd (char *name, enum command_class class,
 		struct cmd_list_element **list)
 {
   struct cmd_list_element *c = add_cmd (name, class, fun, doc, list);
+  struct cmd_list_element *p;
 
   c->prefixlist = prefixlist;
   c->prefixname = prefixname;
   c->allow_unknown = allow_unknown;
+
+  if (list == &cmdlist)
+    c->prefix = NULL;
+  else
+    set_cmd_prefix (c, list);
+
+  /* Update the field 'prefix' of each cmd_list_element in *PREFIXLIST.  */
+  for (p = *prefixlist; p != NULL; p = p->next)
+    p->prefix = c;
+
   return c;
 }
 
@@ -392,6 +453,9 @@ add_setshow_cmd_full (char *name,
 			     full_set_doc, set_list);
   if (set_func != NULL)
     set_cmd_sfunc (set, set_func);
+
+  set_cmd_prefix (set, set_list);
+
   show = add_set_or_show_cmd (name, show_cmd, class, var_type, var,
 			      full_show_doc, show_list);
   show->show_value_func = show_func;
@@ -430,6 +494,8 @@ add_setshow_enum_cmd (char *name,
   c->enums = enumlist;
 }
 
+const char * const auto_boolean_enums[] = { "on", "off", "auto", NULL };
+
 /* Add an auto-boolean command named NAME to both the set and show
    command list lists.  CLASS is as in add_cmd.  VAR is address of the
    variable which will contain the value.  DOC is the documentation
@@ -445,7 +511,6 @@ add_setshow_auto_boolean_cmd (char *name,
 			      struct cmd_list_element **set_list,
 			      struct cmd_list_element **show_list)
 {
-  static const char *auto_boolean_enums[] = { "on", "off", "auto", NULL };
   struct cmd_list_element *c;
 
   add_setshow_cmd_full (name, class, var_auto_boolean, var,