Re: [PATCH v4 4/5] perf config: Add a option 'list-all' to perf-config

[Namhyung Kim <namhyung@kernel.org>]

On Sat, Aug 08, 2015 at 06:50:59PM +0900, Taewoong Song wrote:
> >>>  	OPT_GROUP("Action"),
> >>>  	OPT_BIT('l', "list", &actions,
> >>>  		"show current config variables", ACTION_LIST),
> >>> +	OPT_BIT('a', "list-all", &actions,
> >>> +		"show current and all possible config variables with default values", ACTION_LIST_ALL),
> >> Why did you use OPT_BIT?  Do you want to support multiple 'actions' at
> >> the same time?  I'd rather support just one action, but I won't insist
> >> it strongly..  Anyway, setting bits will confuse the switch statement
> >> in the cmd_config().
> >> 
> >> Thanks,
> >> Namhyung
> >> 
> > I don't understand why setting bits will confuse the switch statement.
> > Is the reason about readability of source code ?
> > 
> > But I searched for other parse-option which can be replaced.
> > Is it better to use OPT_SET_INT instead of OPT_BIT ?
> > 
> 
> I modified source code to use OPT_SET_UINT
> but the problem is happened. I declared "enum actions” to use OPT_SET_UINT like this.
> 
> enum actions {
>     ACTION_LIST,
>     ACTION_LIST_ALL,
>     ACTION_REMOVE
> } actions;
> 
> But default value of actions” variable is 0 and ACTION_LIST is also 0
> so when ‘get’ or ’set’ feature is used, ‘default:' of the switch statement in cmd_config() can’t reached
> because of default value of ‘actions’ variable is 0.

I don't know what's the problem.  You could either set default value
to -1 or make ACTION_LIST start from 1.

Thanks,
Namhyung