gdb: introduce "set index-cache enabled", deprecate "set index-cache on/off"

The "set index-cache" command is used at the same time as a prefix
command (prefix for "set index-cache directory", for example), and a
boolean setting for turning the index-cache on and off.  Even though I
did introduce that, I now don't think it's a good idea to do something
non-standard like this.

First, there's no dedicated CLI command to show whether the index-cache
is enabled, so it has to be custom output in the "show index-cache
handler".  Also, it means there's no good way a MI frontend can find out
if the index-cache is enabled.  "-gdb-show index-cache" doesn't show it
in the MI output record:

    (gdb) interpreter-exec mi "-gdb-show index-cache"
    ~"\n"
    ~"The index cache is currently disabled.\n"
    ^done,showlist={option={name="directory",value="/home/simark/.cache/gdb"}}

Fix this by introducing "set/show index-cache enabled on/off", regular
boolean setting commands.  Keep commands "set index-cache on" and "set
index-cache off" as deprecated aliases of "set index-cache enabled",
with respectively the default arguments "on" and "off".

Update tests using "set index-cache on/off" to use the new command.
Update the regexps in gdb.base/maint.exp to figure out whether the
index-cache is enabled or not.  Update the doc to mention the new
commands.

Change-Id: I7d5aaaf7fd22bf47bd03e0023ef4fbb4023b37b3

1 files changed, 41 insertions, 10 deletions

diff --git a/gdb/dwarf2/index-cache.c b/gdb/dwarf2/index-cache.c
index f439b37..06c27db 100644
--- a/gdb/dwarf2/index-cache.c
+++ b/gdb/dwarf2/index-cache.c
@@ -22,6 +22,7 @@
 
 #include "build-id.h"
 #include "cli/cli-cmds.h"
+#include "cli/cli-decode.h"
 #include "command.h"
 #include "gdbsupport/scoped_mmap.h"
 #include "gdbsupport/pathstuff.h"
@@ -267,20 +268,32 @@ show_index_cache_command (const char *arg, int from_tty)
      global_index_cache.enabled () ? _("enabled") : _("disabled"));
 }
 
-/* "set index-cache on" handler.  */
+/* "set/show index-cache enabled" set callback.  */
 
 static void
-set_index_cache_on_command (const char *arg, int from_tty)
+set_index_cache_enabled_command (bool value)
 {
-  global_index_cache.enable ();
+  if (value)
+    global_index_cache.enable ();
+  else
+    global_index_cache.disable ();
+}
+
+/* "set/show index-cache enabled" get callback.  */
+
+static bool
+get_index_cache_enabled_command ()
+{
+  return global_index_cache.enabled ();
 }
 
-/* "set index-cache off" handler.  */
+/* "set/show index-cache enabled" show callback.  */
 
 static void
-set_index_cache_off_command (const char *arg, int from_tty)
+show_index_cache_enabled_command (ui_file *stream, int from_tty,
+				  cmd_list_element *cmd, const char *value)
 {
-  global_index_cache.disable ();
+  fprintf_filtered (stream, _("The index cache is %s.\n"), value);
 }
 
 /* "set index-cache directory" handler.  */
@@ -342,13 +355,31 @@ _initialize_index_cache ()
 		  _("Show index-cache options."), &show_index_cache_prefix_list,
 		  false, &showlist);
 
+  /* set/show index-cache enabled */
+  set_show_commands setshow_index_cache_enabled_cmds
+    = add_setshow_boolean_cmd ("enabled", class_files,
+			       _("Enable the index cache."),
+			       _("Show whether the index cache is enabled."),
+			       _("help doc"),
+			       set_index_cache_enabled_command,
+			       get_index_cache_enabled_command,
+			       show_index_cache_enabled_command,
+			       &set_index_cache_prefix_list,
+			       &show_index_cache_prefix_list);
+
   /* set index-cache on */
-  add_cmd ("on", class_files, set_index_cache_on_command,
-	   _("Enable the index cache."), &set_index_cache_prefix_list);
+  cmd_list_element *set_index_cache_on_cmd
+    = add_alias_cmd ("on", setshow_index_cache_enabled_cmds.set, class_files,
+		     false, &set_index_cache_prefix_list);
+  deprecate_cmd (set_index_cache_on_cmd, "set index-cache enabled on");
+  set_index_cache_on_cmd->default_args = "on";
 
   /* set index-cache off */
-  add_cmd ("off", class_files, set_index_cache_off_command,
-	   _("Disable the index cache."), &set_index_cache_prefix_list);
+  cmd_list_element *set_index_cache_off_cmd
+    = add_alias_cmd ("off", setshow_index_cache_enabled_cmds.set, class_files,
+		     false, &set_index_cache_prefix_list);
+  deprecate_cmd (set_index_cache_off_cmd, "set index-cache enabled off");
+  set_index_cache_off_cmd->default_args = "off";
 
   /* set index-cache directory */
   add_setshow_filename_cmd ("directory", class_files, &index_cache_directory,