[cfe-dev] CommandLine: using cl::Positional with enum

[Vane, Edwin]

You might try asking the llvm-dev mailing list too since the command line library is a part of LLVM.

In any case, if I understand your description it sounds like you're trying to implement a 'subcommand'-like interface (like svn, git, etc). I'm not sure how I'd do that with the command-line library but I suspect it'll require some extension to support this kind of thing.

> -----Original Message-----
> From: cfe-dev-bounces at cs.uiuc.edu [mailto:cfe-dev-bounces at cs.uiuc.edu] On
> Behalf Of Pedro Delgado Perez
> Sent: Saturday, May 04, 2013 12:44 PM
> To: cfe-dev at cs.uiuc.edu
> Subject: [cfe-dev] CommandLine: using cl::Positional with enum
> 
> Hi,
> 
> I've been trying to code through CommandLine the options I want my tool
> accepts, but I find find quite impossible to achieve robustly what I need .
> 
> Look, I want the tool accepts a list of arguments in a particular order. For this
> goal, I know the cl::Positional flag. But, the problem is that the first argument
> must be one of a set of options. In my case, only the three next commands are
> possible:
> myTool option1
> myTool option2  arg1  arg2
> myTool option3  arg1
> 
> and I don't want a different order is possible, for instance, this is not permitted:
> myTool arg2 option2 arg1
> 
> So, I thought about using an enum for this first argument:
> 
> 
> enum OptLevel{
> option1, option2, option3
> };
> cl::opt<OptLevel> OptionsLevel(cl::Positional, cl::desc("Choose one of these
> options:"), cl::values( clEnumVal(option1, "..."), clEnumVal(option2, "..."),
> clEnumVal(option3, "..."),
>   clEnumValEnd),
> );
> 
> 
> After that, the rest of arguments are also particular of the option selected as the
> first argument, i.e, the rest of arguments are related with the first one. So I
> thought I could independently parse these arguments with:
> 
> cl::list<std::string>  Argv (cl::ConsumeAfter, cl::desc("<program arguments>..."));
> 
> But, doing this when I run:
> 
> myTool option1 file.cpp --
> 
> I got the next error:
> "error - this positional option will never be matched, because it does not Require
> a value and a cl::ConsumeAfter option is active!"
> 
> So, I modify "OptionsLevelOptionsLevel" including the cl::Required flagThe error
> is now:
> "option: does not allow a value! option1 specified.
> option: must be specified at least once!
> option: must be specified at least once!
> option: must be specified at least once!"
> 
> Then, I decided to use cl::PositionalEatsArgs instead of cl::ConsumeAfter. Then,
> this is the result:
> "option: does not allow a value! option1 specified."
> 
> But, this time, the program continues. However, if I run "myTool option3 arg1
> file.cpp --" it gives me a different problem:
> "warning: ../build/arg1: 'linker' input unused
> error: unable to handle compilation, expected exactly one compiler job in ' '"
> 
> But the program still goes on.
> 
> Is there a way to accomplish what I have explained? I don't want those errors
> and warnings.
> 
> Thanks,
> 
> Pedro.
> 
> 
>