gsctool: refactor command line arguments processing

There are a couple of issues with command line processing code:

  - command line options must be listed in two different places if we
    want to allow both short and long forms of the same argument

  - help text for commands is included in yet another place in the code

Indeed, from the libc getopt_long() point of view the long options
table and short options string are completely unrelated: the function
scans the command line arguments vector for -x[x[y]] or --word command
line options style and looks up either short_opts or long_opts
depending on the encountered command line token's style.

The standard way to cross reference long options table and the short
options string is to put the short option character in the long option
table's entries .val field. This is how it is done in gsctool.

What this means is that as long as all short command options are
referenced in the long_opts table, the short command option string
could be generated based no the long_opts table.

The help text and long_opts table would still remain separate and
require manual syncing.

To help with that problem this patch introduces a container structure,
which includes both long option contents and the help text for each
command line option.

This allows to build the long_opts table and then the short_opts
string on the fly, based on the contents of the single table, and also
generated the --help output, ensuring consistency of all
representations.

BRANCH=none
BUG=none
TEST=as follows:

   - temporarily added debug code to print out the generated short
     option string, got the following:

  aBbcd:fF:hIikLMmn:O:oPpR:rS:stUuVvw

    which is extended to include previously omitted 'f':

  aBbcd:F:fhIikLMmn:O:oPpR:rS:stUuVvw

  - verified that 'gsctool -h' outputs before and after this patch are
    the same apart from including help text for -B

  - verified that it is still possible to update a Cr50

  - verified --board_id/-i command with various optional parameter
    representations.

Change-Id: Ie8d409c6c8866247323cee93ce5b9bfbe22046fa
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1617077
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Andrey Pronin <apronin@chromium.org>

0 files changed, 0 insertions, 0 deletions