PATCH: Add MaskNeeded property to option handling

[Joseph S. Myers]

On Sun, 25 Mar 2012, H.J. Lu wrote:

> Hi Joseph,
> 
> I need to support InverseMask(XXX) in options without the corresponding
> Mask(XXX) since XXX is never set directly via a command line option. This
> patch adds a MaskNeeded property which turns InverseMask(XXX) into
> the inverse version of Mask(XXX), which allocates a unique bit and defines
> the same set of macros as Mask(XXX).  Does it look OK?

I'd have thought that either Mask or InverseMask with a given mask name 
(or a standalone target mask record) should cause allocation (only once, 
no matter how many options use the same mask name), and MaskExists should 
be removed, rather than adding MaskNeeded - if I understood correctly the 
purpose for which you are adding MaskNeeded.

-- 
Joseph S. Myers
joseph@codesourcery.com