devtool: categorise and order subcommands in help output
The listing of subcommands in the --help output for devtool was starting
to get difficult to follow, with commands appearing in no particular
order (due to some being in separate modules and the order of those
modules being parsed). Logically grouping the subcommands as well as
being able to exercise some control over the order of the subcommands
and groups would help, if we do so without losing the dynamic nature of
the list (i.e. that it comes from the plugins). Argparse provides no
built-in way to handle this and really, really makes it a pain to add,
but with some subclassing and hacking it's now possible, and can be
extended by any plugin as desired.
To put a subcommand into a group, all you need to do is specify a group=
parameter in the call to subparsers.add_parser(). you can also specify
an order= parameter to make the subcommand sort higher or lower in the
list (higher order numbers appear first, so use negative numbers to
force items to the end if that's what you want). To add a new group, use
subparsers.add_subparser_group(), supplying the name, description and
optionally an order number for the group itself (again, higher numbers
appear first).
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
