[PATCH 3/3] gdb: add the 'set/show suppress-notification-cli' command

[Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>]

GDB already has a flag to suppress printing notification events, such
as thread and inferior context switches, on the CLI.  This is used
internally when executing commands.  Make the flag available to the
user via a new command.  This is expected to be useful in scripts.
---
 gdb/NEWS                                      |  5 +++
 gdb/cli/cli-cmds.c                            | 35 +++++++++++++++++++
 .../gdb.base/cli-suppress-notification.c      | 22 ++++++++++++
 .../gdb.base/cli-suppress-notification.exp    | 33 +++++++++++++++++
 4 files changed, 95 insertions(+)
 create mode 100644 gdb/testsuite/gdb.base/cli-suppress-notification.c
 create mode 100644 gdb/testsuite/gdb.base/cli-suppress-notification.exp

diff --git a/gdb/NEWS b/gdb/NEWS
index eeca1d39b10..76c9738bf03 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -39,6 +39,11 @@ set logging enabled on|off
 show logging enabled
   These commands set or show whether logging is enabled or disabled.
 
+maint set suppress-notification-cli (on|off)
+maint show suppress-notification-cli
+  This controls whether printing the notification events is suppressed
+  for CLI.
+
 * Changed commands
 
 maint packet
diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
index 3fe47940076..5ad0a29052c 100644
--- a/gdb/cli/cli-cmds.c
+++ b/gdb/cli/cli-cmds.c
@@ -192,6 +192,11 @@ static const char *const script_ext_enums[] = {
 
 static const char *script_ext_mode = script_ext_soft;
 \f
+
+/* User-controllable flag to suppress event notification on CLI.  */
+
+static bool user_wants_cli_suppress_notification = false;
+
 /* Utility used everywhere when at least one argument is needed and
    none is supplied.  */
 
@@ -2123,6 +2128,24 @@ show_max_user_call_depth (struct ui_file *file, int from_tty,
 		    value);
 }
 
+static void
+maint_show_suppress_notification_cli (ui_file *file, int from_tty,
+				      cmd_list_element *c, const char *value)
+{
+  fprintf_filtered (file, _("Suppression of printing CLI notification events "
+			    "is %s.\n"), value);
+}
+
+static void
+maint_set_suppress_notification_cli (const char *args, int from_tty,
+				     cmd_list_element *c)
+{
+  cli_suppress_notification.user_selected_context
+    = user_wants_cli_suppress_notification;
+  cli_suppress_notification.normal_stop
+    = user_wants_cli_suppress_notification;
+}
+
 /* Returns the cmd_list_element in SHOWLIST corresponding to the first
    argument of ARGV, which must contain one single value.
    Throws an error if no value provided, or value not correct.
@@ -2720,6 +2743,18 @@ Make \"wLapPeu\" an alias of 2 nested \"with\":\n\
 
   set_cmd_completer_handle_brkchars (c, alias_command_completer);
 
+  add_setshow_boolean_cmd ("suppress-notification-cli", no_class,
+			   &user_wants_cli_suppress_notification,
+			   _("\
+Set whether printing notification events on CLI is suppressed."), _("\
+Show whether printing notification events on CLI is suppressed."), _("\
+When on, printing notification events (such as inferior/thread switch)\n\
+on CLI is suppressed."),
+			   maint_set_suppress_notification_cli,
+			   maint_show_suppress_notification_cli,
+			   &maintenance_set_cmdlist,
+			   &maintenance_show_cmdlist);
+
   const char *source_help_text = xstrprintf (_("\
 Read commands from a file named FILE.\n\
 \n\
diff --git a/gdb/testsuite/gdb.base/cli-suppress-notification.c b/gdb/testsuite/gdb.base/cli-suppress-notification.c
new file mode 100644
index 00000000000..d5142fed2ca
--- /dev/null
+++ b/gdb/testsuite/gdb.base/cli-suppress-notification.c
@@ -0,0 +1,22 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2020-2021 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+int
+main ()
+{
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.base/cli-suppress-notification.exp b/gdb/testsuite/gdb.base/cli-suppress-notification.exp
new file mode 100644
index 00000000000..97fc83eb94a
--- /dev/null
+++ b/gdb/testsuite/gdb.base/cli-suppress-notification.exp
@@ -0,0 +1,33 @@
+# Copyright 2020-2021 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Test the cli-suppress-notification command.
+
+standard_testfile
+
+if {[prepare_for_testing "failed to prepare" ${binfile} ${srcfile}]} {
+    return
+}
+
+if {![runto_main]} {
+    return
+}
+
+gdb_test "inferior 1" ".*Switching to inferior 1 .* to thread 1 .*" \
+    "not suppressed"
+
+gdb_test_no_output "maint set suppress-notification-cli on"
+
+gdb_test_no_output "inferior 1" "suppressed"
-- 
2.33.1

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