Re: [PATCH v2 1/4] keyval: Parse help options

[Markus Armbruster]

Kevin Wolf <kwolf@redhat.com> writes:

> Am 30.09.2020 um 15:35 hat Eric Blake geschrieben:
>> On 9/30/20 7:45 AM, Kevin Wolf wrote:
>> > This adds a new parameter 'help' to keyval_parse() that enables parsing
>> > of help options. If NULL is passed, the function behaves the same as
>> > before. But if a bool pointer is given, it contains the information
>> > whether an option "help" without value was given (which would otherwise
>> > either result in an error or be interpreted as the value for an implied
>> > key).
>> > 
>> > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
[...]
>> > +++ b/util/keyval.c
>> > @@ -166,7 +166,7 @@ static QObject *keyval_parse_put(QDict *cur,
>> >   * On failure, return NULL.
>> >   */
>> >  static const char *keyval_parse_one(QDict *qdict, const char *params,
>> > -                                    const char *implied_key,
>> > +                                    const char *implied_key, bool *help,
>> >                                      Error **errp)
>> >  {
>> >      const char *key, *key_end, *s, *end;
>> > @@ -238,13 +238,20 @@ static const char *keyval_parse_one(QDict *qdict, 
>> > const char *params,
>> >      if (key == implied_key) {
>> >          assert(!*s);
>> >          s = params;
>> > +    } else if (*s == '=') {
>> > +        s++;
>> >      } else {
>> > -        if (*s != '=') {
>> > +        if (help && !strncmp(key, "help", s - key)) {
>> 
>> Should this use is_help_option() to also accept "?", or are we okay
>> demanding exactly "help"?
>
> The comment for is_help_option() calls "?" deprecated, so I think we
> don't want to enable it in a new parser.

Valid point.

But do we really want comparisons for "help" inline everywhere we want
to check for non-deprecated help requests?  Would a common helper
function be better?

On the deprecation of "?": the comment is more than eight years old
(commit c8057f951d6).  We didn't have a deprecation process back then,
but we did purge '?' from the documentation.  Can we finally drop it?
I'm going to ask that in a new thread.

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