Replace most calls to help_list and cmd_show_list

Currently there are many prefix commands that do nothing but call
either help_list or cmd_show_list.  I happened to notice that one such
call, for "set print type", used the wrong command list parameter,
causing incorrect output.

Rather than fix this bug in isolation, I decided to eliminate this
possibility by adding two new ways to add prefix commands, which
simply route the call to help_list or cmd_show_list, as appropriate.
This makes it impossible for a mismatch to occur.

In some cases, a bit of output was removed; however, I don't think
this output in general was very useful.  It seemed redundant with
what's already printed by help_list.  A representative example is this
hunk, removed from ada-lang.c:

-  printf_unfiltered (_(\
-"\"set ada\" must be followed by the name of a setting.\n"));

This simplified the CLI style set/show commands quite a bit, and
allowed the deletion of a macro.

This also cleans up some unusual code in windows-tdep.c.

Tested on x86-64 Fedora 30.  Note that I have no way to build the
go32-nat.c change.

gdb/ChangeLog
2020-04-17  Tom Tromey  <tromey@adacore.com>

	* auto-load.c (show_auto_load_cmd): Remove.
	(auto_load_show_cmdlist_get): Use add_show_prefix_cmd.
	* arc-tdep.c (_initialize_arc_tdep): Use add_show_prefix_cmd.
	(maintenance_print_arc_command): Remove.
	* tui/tui-win.c (tui_command): Remove.
	(tui_get_cmd_list): Use add_basic_prefix_cmd.
	* tui/tui-layout.c (tui_layout_command): Remove.
	(_initialize_tui_layout): Use add_basic_prefix_cmd.
	* python/python.c (user_set_python, user_show_python): Remove.
	(_initialize_python): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* guile/guile.c (set_guile_command, show_guile_command): Remove.
	(install_gdb_commands): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	(info_guile_command): Remove.
	* dwarf2/read.c (set_dwarf_cmd, show_dwarf_cmd): Remove.
	(_initialize_dwarf2_read): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* cli/cli-style.h (class cli_style_option) <add_setshow_commands>:
	Remove do_set and do_show parameters.
	* cli/cli-style.c (set_style, show_style): Remove.
	(_initialize_cli_style): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	(cli_style_option::add_setshow_commands): Remove do_set and
	do_show parameters.
	(cli_style_option::add_setshow_commands): Use
	add_basic_prefix_cmd, add_show_prefix_cmd.
	(STYLE_ADD_SETSHOW_COMMANDS): Remove macro.
	(set_style_name): Remove.
	* cli/cli-dump.c (dump_command, append_command): Remove.
	(srec_dump_command, ihex_dump_command, verilog_dump_command)
	(tekhex_dump_command, binary_dump_command)
	(binary_append_command): Remove.
	(_initialize_cli_dump): Use add_basic_prefix_cmd.
	* windows-tdep.c (w32_prefix_command_valid): Remove global.
	(init_w32_command_list): Remove; move into ...
	(_initialize_windows_tdep): ... here.  Use add_basic_prefix_cmd.
	* valprint.c (set_print, show_print, set_print_raw)
	(show_print_raw): Remove.
	(_initialize_valprint): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* typeprint.c (set_print_type, show_print_type): Remove.
	(_initialize_typeprint): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* record.c (set_record_command, show_record_command): Remove.
	(_initialize_record): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* cli/cli-cmds.c (_initialize_cli_cmds): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	(info_command, show_command, set_debug, show_debug): Remove.
	* top.h (set_history, show_history): Don't declare.
	* top.c (set_history, show_history): Remove.
	* target-descriptions.c (set_tdesc_cmd, show_tdesc_cmd)
	(unset_tdesc_cmd): Remove.
	(_initialize_target_descriptions): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* symtab.c (info_module_command): Remove.
	(_initialize_symtab): Use add_basic_prefix_cmd.
	* symfile.c (overlay_command): Remove.
	(_initialize_symfile): Use add_basic_prefix_cmd.
	* sparc64-tdep.c (info_adi_command): Remove.
	(_initialize_sparc64_adi_tdep): Use add_basic_prefix_cmd.
	* sh-tdep.c (show_sh_command, set_sh_command): Remove.
	(_initialize_sh_tdep): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* serial.c (serial_set_cmd, serial_show_cmd): Remove.
	(_initialize_serial): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* ser-tcp.c (set_tcp_cmd, show_tcp_cmd): Remove.
	(_initialize_ser_tcp): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* rs6000-tdep.c (set_powerpc_command, show_powerpc_command)
	(_initialize_rs6000_tdep): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* riscv-tdep.c (show_riscv_command, set_riscv_command)
	(show_debug_riscv_command, set_debug_riscv_command): Remove.
	(_initialize_riscv_tdep): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* remote.c (remote_command, set_remote_cmd): Remove.
	(_initialize_remote): Use add_basic_prefix_cmd.
	* record-full.c (set_record_full_command)
	(show_record_full_command): Remove.
	(_initialize_record_full): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* record-btrace.c (cmd_set_record_btrace)
	(cmd_show_record_btrace, cmd_set_record_btrace_bts)
	(cmd_show_record_btrace_bts, cmd_set_record_btrace_pt)
	(cmd_show_record_btrace_pt): Remove.
	(_initialize_record_btrace): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* ravenscar-thread.c (set_ravenscar_command)
	(show_ravenscar_command): Remove.
	(_initialize_ravenscar): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* mips-tdep.c (show_mips_command, set_mips_command)
	(_initialize_mips_tdep): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* maint.c (maintenance_command, maintenance_info_command)
	(maintenance_check_command, maintenance_print_command)
	(maintenance_set_cmd, maintenance_show_cmd): Remove.
	(_initialize_maint_cmds): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	(show_per_command_cmd): Remove.
	* maint-test-settings.c (maintenance_set_test_settings_cmd):
	Remove.
	(maintenance_show_test_settings_cmd): Remove.
	(_initialize_maint_test_settings): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* maint-test-options.c (maintenance_test_options_command):
	Remove.
	(_initialize_maint_test_options): Use add_basic_prefix_cmd.
	* macrocmd.c (macro_command): Remove
	(_initialize_macrocmd): Use add_basic_prefix_cmd.
	* language.c (set_check, show_check): Remove.
	(_initialize_language): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* infcmd.c (unset_command): Remove.
	(_initialize_infcmd): Use add_basic_prefix_cmd.
	* i386-tdep.c (set_mpx_cmd, show_mpx_cmd): Remove.
	(_initialize_i386_tdep): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* go32-nat.c (go32_info_dos_command): Remove.
	(_initialize_go32_nat): Use add_basic_prefix_cmd.
	* cli/cli-decode.c (do_prefix_cmd, add_basic_prefix_cmd)
	(do_show_prefix_cmd, add_show_prefix_cmd): New functions.
	* frame.c (set_backtrace_cmd, show_backtrace_cmd): Remove.
	(_initialize_frame): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* dcache.c (set_dcache_command, show_dcache_command): Remove.
	(_initialize_dcache): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* cp-support.c (maint_cplus_command): Remove.
	(_initialize_cp_support): Use add_basic_prefix_cmd.
	* btrace.c (maint_btrace_cmd, maint_btrace_set_cmd)
	(maint_btrace_show_cmd, maint_btrace_pt_set_cmd)
	(maint_btrace_pt_show_cmd, _initialize_btrace): Use
	add_basic_prefix_cmd, add_show_prefix_cmd.
	* breakpoint.c (save_command): Remove.
	(_initialize_breakpoint): Use add_basic_prefix_cmd.
	* arm-tdep.c (set_arm_command, show_arm_command): Remove.
	(_initialize_arm_tdep): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* ada-lang.c (maint_set_ada_cmd, maint_show_ada_cmd)
	(set_ada_command, show_ada_command): Remove.
	(_initialize_ada_language): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* command.h (add_basic_prefix_cmd, add_show_prefix_cmd): Declare.

gdb/testsuite/ChangeLog
2020-04-17  Tom Tromey  <tromey@adacore.com>

	* gdb.cp/maint.exp (test_help): Simplify multiple_help_body.
	Update tests.
	* gdb.btrace/cpu.exp: Update tests.
	* gdb.base/maint.exp: Update tests.
	* gdb.base/default.exp: Update tests.
	* gdb.base/completion.exp: Update tests.

1 files changed, 18 insertions, 51 deletions

diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
index 6f32441..f717851 100644
--- a/gdb/cli/cli-cmds.c
+++ b/gdb/cli/cli-cmds.c
@@ -191,26 +191,6 @@ error_no_arg (const char *why)
   error (_("Argument required (%s)."), why);
 }
 
-/* The "info" command is defined as a prefix, with allow_unknown = 0.
-   Therefore, its own definition is called only for "info" with no
-   args.  */
-
-static void
-info_command (const char *arg, int from_tty)
-{
-  printf_unfiltered (_("\"info\" must be followed by "
-		       "the name of an info command.\n"));
-  help_list (infolist, "info ", all_commands, gdb_stdout);
-}
-
-/* The "show" command with no arguments shows all the settings.  */
-
-static void
-show_command (const char *arg, int from_tty)
-{
-  cmd_show_list (showlist, from_tty, "");
-}
-
 /* See cli/cli-cmds.h.  */
 
 void
@@ -1852,20 +1832,6 @@ filter_sals (std::vector<symtab_and_line> &sals)
   sals.erase (from, sals.end ());
 }
 
-static void
-set_debug (const char *arg, int from_tty)
-{
-  printf_unfiltered (_("\"set debug\" must be followed by "
-		       "the name of a debug subcommand.\n"));
-  help_list (setdebuglist, "set debug ", all_commands, gdb_stdout);
-}
-
-static void
-show_debug (const char *args, int from_tty)
-{
-  cmd_show_list (showdebuglist, from_tty, "");
-}
-
 void
 init_cmd_lists (void)
 {
@@ -2208,12 +2174,12 @@ Show verbosity."), NULL,
 			   show_info_verbose,
 			   &setlist, &showlist);
 
-  add_prefix_cmd ("history", class_support, set_history,
-		  _("Generic command for setting command history parameters."),
-		  &sethistlist, "set history ", 0, &setlist);
-  add_prefix_cmd ("history", class_support, show_history,
-		  _("Generic command for showing command history parameters."),
-		  &showhistlist, "show history ", 0, &showlist);
+  add_basic_prefix_cmd ("history", class_support, _("\
+Generic command for setting command history parameters."),
+			&sethistlist, "set history ", 0, &setlist);
+  add_show_prefix_cmd ("history", class_support, _("\
+Generic command for showing command history parameters."),
+		       &showhistlist, "show history ", 0, &showlist);
 
   add_setshow_boolean_cmd ("expansion", no_class, &history_expansion_p, _("\
 Set history expansion on command input."), _("\
@@ -2223,20 +2189,21 @@ Without an argument, history expansion is enabled."),
 			   show_history_expansion_p,
 			   &sethistlist, &showhistlist);
 
-  add_prefix_cmd ("info", class_info, info_command, _("\
+  add_basic_prefix_cmd ("info", class_info, _("\
 Generic command for showing things about the program being debugged."),
-		  &infolist, "info ", 0, &cmdlist);
+			&infolist, "info ", 0, &cmdlist);
   add_com_alias ("i", "info", class_info, 1);
   add_com_alias ("inf", "info", class_info, 1);
 
   add_com ("complete", class_obscure, complete_command,
 	   _("List the completions for the rest of the line as a command."));
 
-  add_prefix_cmd ("show", class_info, show_command, _("\
+  add_show_prefix_cmd ("show", class_info, _("\
 Generic command for showing things about the debugger."),
-		  &showlist, "show ", 0, &cmdlist);
+		       &showlist, "show ", 0, &cmdlist);
   /* Another way to get at the same thing.  */
-  add_info ("set", show_command, _("Show all GDB settings."));
+  add_show_prefix_cmd ("set", class_info, _("Show all GDB settings."),
+		       &showlist, "info set ", 0, &infolist);
 
   c = add_com ("with", class_vars, with_command, _("\
 Temporarily set SETTING to VALUE, run COMMAND, and restore SETTING.\n\
@@ -2324,13 +2291,13 @@ from the target."),
 				       show_remote_timeout,
 				       &setlist, &showlist);
 
-  add_prefix_cmd ("debug", no_class, set_debug,
-		  _("Generic command for setting gdb debugging flags."),
-		  &setdebuglist, "set debug ", 0, &setlist);
+  add_basic_prefix_cmd ("debug", no_class,
+			_("Generic command for setting gdb debugging flags."),
+			&setdebuglist, "set debug ", 0, &setlist);
 
-  add_prefix_cmd ("debug", no_class, show_debug,
-		  _("Generic command for showing gdb debugging flags."),
-		  &showdebuglist, "show debug ", 0, &showlist);
+  add_show_prefix_cmd ("debug", no_class,
+		       _("Generic command for showing gdb debugging flags."),
+		       &showdebuglist, "show debug ", 0, &showlist);
 
   c = add_com ("shell", class_support, shell_command, _("\
 Execute the rest of the line as a shell command.\n\