[gdb/cli] Add "set logging enabled", deprecate "set logging on/off"

Before commit 3b6acaee895 "Update more calls to add_prefix_cmd" we had the
following output for "show logging file":
...
$ gdb -q -batch -ex "set trace-commands on" \
    -ex "set logging off" \
    -ex "show logging file" \
    -ex "set logging on" \
    -ex "show logging file"
+set logging off
+show logging file
Future logs will be written to gdb.txt.
+set logging on
+show logging file
Currently logging to "gdb.txt".
...

After that commit we have instead:
...
+set logging off
+show logging file
The current logfile is "gdb.txt".
+set logging on
+show logging file
The current logfile is "gdb.txt".
...

Before the commit, whether logging is enabled or not can be deduced from the
output of the command.  After the commit, the message is unified and it's no
longer clear whether logging is enabled or not.

Fix this by:
- adding a new command "show logging enabled"
- adding a corresponding new command "set logging enabled on/off"
- making the commands "set logging on/off" deprecated aliases of the
  "set logging enabled on/off" command.

Update the docs and testsuite to use "set logging enabled".  Mention the new
and deprecated commands in NEWS.

Tested on x86_64-linux.

1 files changed, 54 insertions, 4 deletions

diff --git a/gdb/cli/cli-logging.c b/gdb/cli/cli-logging.c
index 8efefa0..82be849 100644
--- a/gdb/cli/cli-logging.c
+++ b/gdb/cli/cli-logging.c
@@ -22,6 +22,7 @@
 #include "ui-out.h"
 #include "interps.h"
 #include "cli/cli-style.h"
+#include "cli/cli-decode.h"
 
 static char *saved_filename;
 
@@ -163,18 +164,42 @@ set_logging_off (const char *args, int from_tty)
   saved_filename = NULL;
 }
 
+static bool logging_enabled;
+
+static void
+set_logging_enabled (const char *args,
+		     int from_tty, struct cmd_list_element *c)
+{
+  if (logging_enabled)
+    set_logging_on (args, from_tty);
+  else
+    set_logging_off (args, from_tty);
+}
+
+static void
+show_logging_enabled (struct ui_file *file, int from_tty,
+		       struct cmd_list_element *c, const char *value)
+{
+  if (logging_enabled)
+    printf_unfiltered (_("Logging is enabled.\n"));
+  else
+    printf_unfiltered (_("Logging is disabled.\n"));
+}
+
 void _initialize_cli_logging ();
 void
 _initialize_cli_logging ()
 {
   static struct cmd_list_element *set_logging_cmdlist, *show_logging_cmdlist;
 
+  /* Set/show logging.  */
   add_setshow_prefix_cmd ("logging", class_support,
 			  _("Set logging options."),
 			  _("Show logging options."),
 			  &set_logging_cmdlist, &show_logging_cmdlist,
 			  &setlist, &showlist);
 
+  /* Set/show logging overwrite.  */
   add_setshow_boolean_cmd ("overwrite", class_support, &logging_overwrite, _("\
 Set whether logging overwrites or appends to the log file."), _("\
 Show whether logging overwrites or appends to the log file."), _("\
@@ -182,6 +207,8 @@ If set, logging overwrites the log file."),
 			   set_logging_overwrite,
 			   show_logging_overwrite,
 			   &set_logging_cmdlist, &show_logging_cmdlist);
+
+  /* Set/show logging redirect.  */
   add_setshow_boolean_cmd ("redirect", class_support, &logging_redirect, _("\
 Set the logging output mode."), _("\
 Show the logging output mode."), _("\
@@ -190,6 +217,8 @@ If redirect is on, output will go only to the log file."),
 			   set_logging_redirect,
 			   show_logging_redirect,
 			   &set_logging_cmdlist, &show_logging_cmdlist);
+
+  /* Set/show logging debugredirect.  */
   add_setshow_boolean_cmd ("debugredirect", class_support,
 			   &debug_redirect, _("\
 Set the logging debug output mode."), _("\
@@ -200,6 +229,7 @@ If debug redirect is on, debug will go only to the log file."),
 			   show_logging_redirect,
 			   &set_logging_cmdlist, &show_logging_cmdlist);
 
+  /* Set/show logging file.  */
   add_setshow_filename_cmd ("file", class_support, &logging_filename, _("\
 Set the current logfile."), _("\
 Show the current logfile."), _("\
@@ -207,8 +237,28 @@ The logfile is used when directing GDB's output."),
 			    NULL,
 			    show_logging_filename,
 			    &set_logging_cmdlist, &show_logging_cmdlist);
-  add_cmd ("on", class_support, set_logging_on,
-	   _("Enable logging."), &set_logging_cmdlist);
-  add_cmd ("off", class_support, set_logging_off,
-	   _("Disable logging."), &set_logging_cmdlist);
+
+  /* Set/show logging enabled.  */
+  set_show_commands setshow_logging_enabled_cmds
+    = add_setshow_boolean_cmd ("enabled", class_support, &logging_enabled,
+			       _("Enable logging."),
+			       _("Show whether logging is enabled."),
+			       _("When on, enable logging."),
+			       set_logging_enabled,
+			       show_logging_enabled,
+			       &set_logging_cmdlist, &show_logging_cmdlist);
+
+  /* Set logging on, deprecated alias.  */
+  cmd_list_element *set_logging_on_cmd
+    = add_alias_cmd ("on", setshow_logging_enabled_cmds.set, class_support,
+		     false, &set_logging_cmdlist);
+  deprecate_cmd (set_logging_on_cmd, "set logging enabled on");
+  set_logging_on_cmd->default_args = "on";
+
+  /* Set logging off, deprecated alias.  */
+  cmd_list_element *set_logging_off_cmd
+    = add_alias_cmd ("off", setshow_logging_enabled_cmds.set, class_support,
+		     false, &set_logging_cmdlist);
+  deprecate_cmd (set_logging_off_cmd, "set logging enabled off");
+  set_logging_off_cmd->default_args = "off";
 }