[CMake] Parsing cmake command line parameters

[Bill Hoffman]

Rodolfo Schulz de Lima wrote:
> Alexander Neundorf escreveu:
>> If you can find some spare time, there is a command argument parser in 
>> CMake/Source/kwsys/, which is used e.g. by cpack, but not (yet) by 
>> cmake. Using this in cmake is the first step in getting better support 
>> for custom command line parameters. A patch would be very welcome.
>> Currently I don't have the time.
> 
> I think I'll have some spare time to do this on this weekend, I'd be 
> glad to help if there's enough coordination to avoid unnecessary work 
> duplication.
> 
>> Second idea: maybe it would already help if the command line arguments 
>> to cmake would be available via a special cmake variable.
>> Is there anything which speaks against this, Bill ?
> 
> IMHO, we should differentiate between --enable/--disable and 
> --with/--without,  like it is on autotools' configure. The former used 
> to enable/disable features, the other to compile with/without some 
> external library.
> 
> There's also the ubiquitous --prefix that should be mapped to 
> CMAKE_INSTALL_PREFIX, and the others that commonly appear when we 
> execute 'configure --help'.
> 
> It should be nice to have a framework to facilitate working with 
> enable/disable and with/without. The other common arguments that maps to 
> cmake variables should be set up by default.
> 

The real problem with the command line arguments is how to gather them 
up for a project.   I really have yet figured out a clean way to do 
that.  People will want access to all options in the project, but I 
don't see a way to do that...

-Bill