New set/show testing framework (gdb.base/settings.exp)

This commit adds new representative commands for all types of settings
commands supported by gdb (enum var_types), and then uses them to
exercise settings parsing and completion.

  (gdb) maint test-settings s[TAB]
  set   show

  (gdb) maint test-settings set [TAB]
  auto-boolean         integer              uinteger
  boolean              optional-filename    zinteger
  enum                 string               zuinteger
  filename             string-noescape      zuinteger-unlimited

  (gdb) maint test-settings set enum [TAB]
  xxx  yyy  zzz

  etc.

This is basically unit testing, except that it goes fully via GDB.  It
must be done this way in order to exercise TAB completion properly,
which must go via readline.

gdb/ChangeLog:
2019-06-13  Pedro Alves  <palves@redhat.com>

	* Makefile.in (COMMON_SFILES): Add maint-test-settings.c.
	* NEWS: Mention maint test-settings KIND.
	* maint-test-settings.c: New file.

gdb/doc/ChangeLog:
2019-06-13  Pedro Alves  <palves@redhat.com>

	* gdb.texinfo (Maintenance Commands): Document "maint
	test-settings" commands.

gdb/testsuite/ChangeLog:
2019-06-13  Pedro Alves  <palves@redhat.com>

	* gdb.base/settings.c: New file.
	* gdb.base/settings.exp: New file.

1 files changed, 257 insertions, 0 deletions

diff --git a/gdb/maint-test-settings.c b/gdb/maint-test-settings.c
new file mode 100644
index 0000000..fa13519
--- /dev/null
+++ b/gdb/maint-test-settings.c
@@ -0,0 +1,257 @@
+/* Support for GDB maintenance commands.
+
+   Copyright (C) 2019 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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/>.  */
+
+
+#include "defs.h"
+#include "gdbcmd.h"
+
+/* Command list for "maint test-settings".  */
+static cmd_list_element *maintenance_test_settings_list;
+
+/* Command list for "maint test-settings set/show".  */
+static cmd_list_element *maintenance_test_settings_set_list;
+static cmd_list_element *maintenance_test_settings_show_list;
+
+/* The "maintenance test-options" prefix command.  */
+
+static void
+maintenance_test_settings_cmd (const char *arg, int from_tty)
+{
+  printf_unfiltered
+    (_("\"maintenance test-settings\" must be followed "
+       "by the name of a subcommand.\n"));
+  help_list (maintenance_test_settings_list, "maintenance test-settings ",
+	     all_commands, gdb_stdout);
+}
+
+/* The "maintenance test-options set" prefix command.  */
+
+static void
+maintenance_test_settings_set_cmd (const char *args, int from_tty)
+{
+  printf_unfiltered (_("\"maintenance test-settings set\" must be followed "
+		       "by the name of a set command.\n"));
+  help_list (maintenance_test_settings_set_list,
+	     "maintenance test-settings set ",
+	     all_commands, gdb_stdout);
+}
+
+/* The "maintenance test-options show" prefix command.  */
+
+static void
+maintenance_test_settings_show_cmd (const char *args, int from_tty)
+{
+  cmd_show_list (maintenance_test_settings_show_list, from_tty, "");
+}
+
+/* Control variables for all the "maintenance test-options set/show
+   xxx" commands.  */
+
+static int maintenance_test_settings_boolean;
+
+static auto_boolean maintenance_test_settings_auto_boolean = AUTO_BOOLEAN_AUTO;
+
+static unsigned int maintenance_test_settings_uinteger;
+
+static int maintenance_test_settings_integer;
+
+static int maintenance_test_settings_zinteger;
+
+static unsigned int maintenance_test_settings_zuinteger;
+
+static int maintenance_test_settings_zuinteger_unlimited;
+
+static char *maintenance_test_settings_string;
+
+static char *maintenance_test_settings_string_noescape;
+
+static char *maintenance_test_settings_optional_filename;
+
+static char *maintenance_test_settings_filename;
+
+static const char *maintenance_test_settings_enum;
+
+/* Enum values for the "maintenance test-settings set/show boolean"
+   commands.  */
+static const char *const maintenance_test_settings_enums[] = {
+  "xxx", "yyy", "zzz", nullptr
+};
+
+/* The "maintenance test-options show xxx" commands.  */
+
+static void
+maintenance_test_settings_show_value_cmd
+  (struct ui_file *file, int from_tty,
+   struct cmd_list_element *c, const char *value)
+{
+  fprintf_filtered (file, (("%s\n")), value);
+}
+
+
+void
+_initialize_maint_test_settings (void)
+{
+  add_prefix_cmd ("test-settings", no_class,
+		  maintenance_test_settings_cmd,
+		  _("\
+Generic command for testing the settings infrastructure."),
+		  &maintenance_test_settings_list,
+		  "maintenance test-settings ", 0,
+		  &maintenancelist);
+
+  add_prefix_cmd ("set", class_maintenance,
+		  maintenance_test_settings_set_cmd, _("\
+Set GDB internal variables used for set/show command infrastructure testing."),
+		  &maintenance_test_settings_set_list,
+		  "maintenance test-settings set ",
+		  0/*allow-unknown*/,
+		  &maintenance_test_settings_list);
+
+  add_prefix_cmd ("show", class_maintenance,
+		  maintenance_test_settings_show_cmd, _("\
+Show GDB internal variables used for set/show command infrastructure testing."),
+		  &maintenance_test_settings_show_list,
+		  "maintenance test-settings show ",
+		  0/*allow-unknown*/,
+		  &maintenance_test_settings_list);
+
+  add_setshow_boolean_cmd ("boolean", class_maintenance,
+			   &maintenance_test_settings_boolean, _("\
+command used for internal testing"), _("\
+command used for internal testing"),
+			   nullptr, /* help_doc */
+			   nullptr, /* set_cmd */
+			   maintenance_test_settings_show_value_cmd,
+			   &maintenance_test_settings_set_list,
+			   &maintenance_test_settings_show_list);
+
+  add_setshow_auto_boolean_cmd ("auto-boolean", class_maintenance,
+				&maintenance_test_settings_auto_boolean, _("\
+command used for internal testing"), _("\
+command used for internal testing"),
+				nullptr, /* help_doc */
+				nullptr, /* set_cmd */
+				maintenance_test_settings_show_value_cmd,
+				&maintenance_test_settings_set_list,
+				&maintenance_test_settings_show_list);
+
+  add_setshow_uinteger_cmd ("uinteger", class_maintenance,
+			   &maintenance_test_settings_uinteger, _("\
+command used for internal testing"), _("\
+command used for internal testing"),
+			   nullptr, /* help_doc */
+			   nullptr, /* set_cmd */
+			   maintenance_test_settings_show_value_cmd,
+			   &maintenance_test_settings_set_list,
+			   &maintenance_test_settings_show_list);
+
+  add_setshow_integer_cmd ("integer", class_maintenance,
+			   &maintenance_test_settings_integer, _("\
+command used for internal testing"), _("\
+command used for internal testing"),
+			   nullptr, /* help_doc */
+			   nullptr, /* set_cmd */
+			   maintenance_test_settings_show_value_cmd,
+			   &maintenance_test_settings_set_list,
+			   &maintenance_test_settings_show_list);
+
+  add_setshow_string_cmd ("string", class_maintenance,
+     &maintenance_test_settings_string, _("\
+command used for internal testing"), _("\
+command used for internal testing"),
+     nullptr, /* help_doc */
+     nullptr, /* set_cmd */
+     maintenance_test_settings_show_value_cmd,
+     &maintenance_test_settings_set_list,
+     &maintenance_test_settings_show_list);
+
+  add_setshow_string_noescape_cmd
+    ("string-noescape", class_maintenance,
+     &maintenance_test_settings_string_noescape, _("\
+command used for internal testing"), _("\
+command used for internal testing"),
+     nullptr, /* help_doc */
+     nullptr, /* set_cmd */
+     maintenance_test_settings_show_value_cmd,
+     &maintenance_test_settings_set_list,
+     &maintenance_test_settings_show_list);
+
+  add_setshow_optional_filename_cmd
+    ("optional-filename", class_maintenance,
+     &maintenance_test_settings_optional_filename, _("\
+command used for internal testing"), _("\
+command used for internal testing"),
+     nullptr, /* help_doc */
+     nullptr, /* set_cmd */
+     maintenance_test_settings_show_value_cmd,
+     &maintenance_test_settings_set_list,
+     &maintenance_test_settings_show_list);
+
+  add_setshow_filename_cmd ("filename", class_maintenance,
+			    &maintenance_test_settings_filename, _("\
+command used for internal testing"), _("\
+command used for internal testing"),
+			    nullptr, /* help_doc */
+			    nullptr, /* set_cmd */
+			    maintenance_test_settings_show_value_cmd,
+			    &maintenance_test_settings_set_list,
+			    &maintenance_test_settings_show_list);
+
+  add_setshow_zinteger_cmd ("zinteger", class_maintenance,
+			    &maintenance_test_settings_zinteger, _("\
+command used for internal testing"), _("\
+command used for internal testing"),
+			    nullptr, /* help_doc */
+			    nullptr, /* set_cmd */
+			    maintenance_test_settings_show_value_cmd,
+			    &maintenance_test_settings_set_list,
+			    &maintenance_test_settings_show_list);
+
+  add_setshow_zuinteger_cmd ("zuinteger", class_maintenance,
+			     &maintenance_test_settings_zuinteger, _("\
+command used for internal testing"), _("\
+command used for internal testing"),
+			     nullptr, /* help_doc */
+			     nullptr, /* set_cmd */
+			     maintenance_test_settings_show_value_cmd,
+			     &maintenance_test_settings_set_list,
+			     &maintenance_test_settings_show_list);
+
+  add_setshow_zuinteger_unlimited_cmd
+    ("zuinteger-unlimited", class_maintenance,
+     &maintenance_test_settings_zuinteger_unlimited, _("\
+command used for internal testing"), _("\
+command used for internal testing"),
+     nullptr, /* help_doc */
+     nullptr, /* set_cmd */
+     maintenance_test_settings_show_value_cmd,
+     &maintenance_test_settings_set_list,
+     &maintenance_test_settings_show_list);
+
+  add_setshow_enum_cmd ("enum", class_maintenance,
+			maintenance_test_settings_enums,
+			&maintenance_test_settings_enum, _("\
+command used for internal testing"), _("\
+command used for internal testing"),
+			nullptr, /* help_doc */
+			nullptr, /* set_cmd */
+			maintenance_test_settings_show_value_cmd,
+			&maintenance_test_settings_set_list,
+			&maintenance_test_settings_show_list);
+}