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e0700ba44c
String-like settings (var_string, var_filename, var_optional_filename, var_string_noescape) currently take a pointer to a `char *` storage variable (typically global) that holds the setting's value. I'd like to "mordernize" this by changing them to use an std::string for storage. An obvious reason is that string operations on std::string are often easier to write than with C strings. And they avoid having to do any manual memory management. Another interesting reason is that, with `char *`, nullptr and an empty string often both have the same meaning of "no value". String settings are initially nullptr (unless initialized otherwise). But when doing "set foo" (where `foo` is a string setting), the setting now points to an empty string. For example, solib_search_path is nullptr at startup, but points to an empty string after doing "set solib-search-path". This leads to some code that needs to check for both to check for "no value". Or some code that converts back and forth between NULL and "" when getting or setting the value. I find this very error-prone, because it is very easy to forget one or the other. With std::string, we at least know that the variable is not "NULL". There is only one way of representing an empty string setting, that is with an empty string. I was wondering whether the distinction between NULL and "" would be important for some setting, but it doesn't seem so. If that ever happens, it would be more C++-y and self-descriptive to use optional<string> anyway. Actually, there's one spot where this distinction mattered, it's in init_history, for the test gdb.base/gdbinit-history.exp. init_history sets the history filename to the default ".gdb_history" if it sees that the setting was never set - if history_filename is nullptr. If history_filename is an empty string, it means the setting was explicitly cleared, so it leaves it as-is. With the change to std::string, this distinction doesn't exist anymore. This can be fixed by moving the code that chooses a good default value for history_filename to _initialize_top. This is ran before -ex commands are processed, so an -ex command can then clear that value if needed (what gdb.base/gdbinit-history.exp tests). Another small improvement, in my opinion is that we can now easily give string parameters initial values, by simply initializing the global variables, instead of xstrdup-ing it in the _initialize function. In Python and Guile, when registering a string-like parameter, we allocate (with new) an std::string that is owned by the param_smob (in Guile) and the parmpy_object (in Python) objects. This patch started by changing all relevant add_setshow_* commands to take an `std::string *` instead of a `char **` and fixing everything that failed to build. That includes of course all string setting variable and their uses. string_option_def now uses an std::string also, because there's a connection between options and settings (see add_setshow_cmds_for_options). The add_path function in source.c is really complex and twisted, I'd rather not try to change it to work on an std::string right now. Instead, I added an overload that copies the std:string to a `char *` and back. This means more copying, but this is not used in a hot path at all, so I think it is acceptable. Change-Id: I92c50a1bdd8307141cdbacb388248e4e4fc08c93 Co-authored-by: Lancelot SIX <lsix@lancelotsix.com>
226 lines
7.7 KiB
C
226 lines
7.7 KiB
C
/* Maintenance commands for testing the settings framework.
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Copyright (C) 2019-2021 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "gdbcmd.h"
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/* Command list for "maint set test-settings". */
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static cmd_list_element *maintenance_set_test_settings_list;
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/* Command list for "maint show test-settings". */
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static cmd_list_element *maintenance_show_test_settings_list;
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/* Control variables for all the "maintenance set/show test-settings
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xxx" commands. */
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static bool maintenance_test_settings_boolean;
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static auto_boolean maintenance_test_settings_auto_boolean = AUTO_BOOLEAN_AUTO;
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static unsigned int maintenance_test_settings_uinteger;
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static int maintenance_test_settings_integer;
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static int maintenance_test_settings_zinteger;
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static unsigned int maintenance_test_settings_zuinteger;
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static int maintenance_test_settings_zuinteger_unlimited;
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static std::string maintenance_test_settings_string;
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static std::string maintenance_test_settings_string_noescape;
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static std::string maintenance_test_settings_optional_filename;
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static std::string maintenance_test_settings_filename;
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/* Enum values for the "maintenance set/show test-settings boolean"
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commands. */
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static const char maintenance_test_settings_xxx[] = "xxx";
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static const char maintenance_test_settings_yyy[] = "yyy";
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static const char maintenance_test_settings_zzz[] = "zzz";
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static const char *const maintenance_test_settings_enums[] = {
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maintenance_test_settings_xxx,
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maintenance_test_settings_yyy,
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maintenance_test_settings_zzz,
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nullptr
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};
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static const char *maintenance_test_settings_enum
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= maintenance_test_settings_xxx;
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/* The "maintenance show test-settings xxx" commands. */
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static void
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maintenance_show_test_settings_value_cmd
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(struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file, (("%s\n")), value);
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}
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void _initialize_maint_test_settings ();
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void
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_initialize_maint_test_settings ()
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{
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maintenance_test_settings_filename = xstrdup ("/foo/bar");
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add_basic_prefix_cmd ("test-settings", class_maintenance,
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_("\
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Set GDB internal variables used for set/show command infrastructure testing."),
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&maintenance_set_test_settings_list,
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0/*allow-unknown*/,
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&maintenance_set_cmdlist);
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add_show_prefix_cmd ("test-settings", class_maintenance,
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_("\
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Show GDB internal variables used for set/show command infrastructure testing."),
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&maintenance_show_test_settings_list,
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0/*allow-unknown*/,
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&maintenance_show_cmdlist);
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add_setshow_boolean_cmd ("boolean", class_maintenance,
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&maintenance_test_settings_boolean, _("\
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command used for internal testing."), _("\
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command used for internal testing."),
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nullptr, /* help_doc */
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nullptr, /* set_cmd */
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maintenance_show_test_settings_value_cmd,
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&maintenance_set_test_settings_list,
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&maintenance_show_test_settings_list);
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add_setshow_auto_boolean_cmd ("auto-boolean", class_maintenance,
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&maintenance_test_settings_auto_boolean, _("\
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command used for internal testing."), _("\
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command used for internal testing."),
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nullptr, /* help_doc */
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nullptr, /* set_cmd */
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maintenance_show_test_settings_value_cmd,
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&maintenance_set_test_settings_list,
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&maintenance_show_test_settings_list);
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add_setshow_uinteger_cmd ("uinteger", class_maintenance,
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&maintenance_test_settings_uinteger, _("\
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command used for internal testing."), _("\
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command used for internal testing."),
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nullptr, /* help_doc */
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nullptr, /* set_cmd */
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maintenance_show_test_settings_value_cmd,
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&maintenance_set_test_settings_list,
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&maintenance_show_test_settings_list);
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add_setshow_integer_cmd ("integer", class_maintenance,
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&maintenance_test_settings_integer, _("\
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command used for internal testing."), _("\
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command used for internal testing."),
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nullptr, /* help_doc */
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nullptr, /* set_cmd */
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maintenance_show_test_settings_value_cmd,
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&maintenance_set_test_settings_list,
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&maintenance_show_test_settings_list);
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add_setshow_string_cmd ("string", class_maintenance,
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&maintenance_test_settings_string, _("\
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command used for internal testing."), _("\
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command used for internal testing."),
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nullptr, /* help_doc */
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nullptr, /* set_cmd */
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maintenance_show_test_settings_value_cmd,
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&maintenance_set_test_settings_list,
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&maintenance_show_test_settings_list);
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add_setshow_string_noescape_cmd
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("string-noescape", class_maintenance,
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&maintenance_test_settings_string_noescape, _("\
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command used for internal testing."), _("\
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command used for internal testing."),
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nullptr, /* help_doc */
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nullptr, /* set_cmd */
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maintenance_show_test_settings_value_cmd,
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&maintenance_set_test_settings_list,
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&maintenance_show_test_settings_list);
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add_setshow_optional_filename_cmd
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("optional-filename", class_maintenance,
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&maintenance_test_settings_optional_filename, _("\
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command used for internal testing."), _("\
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command used for internal testing."),
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nullptr, /* help_doc */
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nullptr, /* set_cmd */
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maintenance_show_test_settings_value_cmd,
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&maintenance_set_test_settings_list,
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&maintenance_show_test_settings_list);
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add_setshow_filename_cmd ("filename", class_maintenance,
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&maintenance_test_settings_filename, _("\
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command used for internal testing."), _("\
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command used for internal testing."),
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nullptr, /* help_doc */
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nullptr, /* set_cmd */
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maintenance_show_test_settings_value_cmd,
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&maintenance_set_test_settings_list,
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&maintenance_show_test_settings_list);
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add_setshow_zinteger_cmd ("zinteger", class_maintenance,
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&maintenance_test_settings_zinteger, _("\
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command used for internal testing."), _("\
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command used for internal testing."),
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nullptr, /* help_doc */
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nullptr, /* set_cmd */
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maintenance_show_test_settings_value_cmd,
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&maintenance_set_test_settings_list,
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&maintenance_show_test_settings_list);
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add_setshow_zuinteger_cmd ("zuinteger", class_maintenance,
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&maintenance_test_settings_zuinteger, _("\
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command used for internal testing."), _("\
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command used for internal testing."),
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nullptr, /* help_doc */
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nullptr, /* set_cmd */
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maintenance_show_test_settings_value_cmd,
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&maintenance_set_test_settings_list,
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&maintenance_show_test_settings_list);
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add_setshow_zuinteger_unlimited_cmd
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("zuinteger-unlimited", class_maintenance,
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&maintenance_test_settings_zuinteger_unlimited, _("\
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command used for internal testing."), _("\
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command used for internal testing."),
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nullptr, /* help_doc */
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nullptr, /* set_cmd */
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maintenance_show_test_settings_value_cmd,
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&maintenance_set_test_settings_list,
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&maintenance_show_test_settings_list);
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add_setshow_enum_cmd ("enum", class_maintenance,
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maintenance_test_settings_enums,
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&maintenance_test_settings_enum, _("\
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command used for internal testing."), _("\
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command used for internal testing."),
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nullptr, /* help_doc */
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nullptr, /* set_cmd */
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maintenance_show_test_settings_value_cmd,
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&maintenance_set_test_settings_list,
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&maintenance_show_test_settings_list);
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}
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