How to create both -option-name-* and -option-name=* options?

[Brooks Moses]

Dave Korn wrote:
> On 10 November 2006 20:06, Mark Mitchell wrote:
>>Dave Korn wrote:
>>>  It may seem a bit radical, but is there any reason not to modify the
>>>option-parsing machinery so that either '-' or '=' are treated
>>>interchangeably for /all/ options with joined arguments?  That is,
>>>whichever is specified in the .opt file, the parser accepts either?
>>
>>I like that idea.
> 
>   Would it be a suitable solution to just provide a specialised wrapper around
> the two strncmp invocations in find_opt?  It seems ok to me; we only want this
> change to affect comparisons, we call whichever form is listed in the .opts
> file the canonical form and just don't worry if the (canonical) way a flag is
> reported in an error message doesn't quite match when the non-canonical form
> was used on the command line?

I would think that would be suitable, certainly.  Having the error 
message report the canonical form would, to me, just be a beneficial 
small reminder to people to use the canonical form.

>   (I'm not even going to mention the 'limitation' that we are now no longer
> free to create -fFLAG=VALUE and -fFLAG-VALUE options with different meanings!)

But that's already not possible -- that's essentially how I got into 
this problem in the first place.  If one tries to define both of those, 
the declaration of the enumeration-type holding the option flags breaks, 
so you can't do that.

(Well, you could hack that to make it work; define -fFLAG as the option 
name, so that the '-' or '=' is the first character of the argument. 
That will still work, but it's a pain if VALUE is otherwise a UInteger.)

This does raise a point about how the options are compared, though -- to 
be useful, this needs to also handle cases where a Joined option is 
emulated by a "normal" option.  For instance, Fortran's lang.opt 
contains something like:

   -ffixed-line-length-none
   Fortran

   -ffixed-line-length-
   Fortran Joined

We would also want "-ffixed-line-length=none" to be handled 
appropriately, which makes this a bit trickier than just handling the 
last character of Joined options.

Are there any meaningful downsides to just having the option-matcher 
treat all '-' and '=' values in the option name as equivalent?  It would 
mean that we'd also match "-ffixed=line=length-none", for instance, but 
I don't think that causes any real harm.

An alternative would be to specify that an '=' in the name in the .opt 
file will match either '=' or '-' on the command line.  This does 
require that the canonical form be the one with '=' in it, and means 
that things with '-' in them need to be changed in the .opt file to 
accept both, but the benefit is that it can accept pseudo-Joined options 
in either form without accepting all sorts of wierd things with random 
'='s in them.

- Brooks