[Bug c/53072] automatically set Init() only if option was not set in some other way

["joseph at codesourcery dot com" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53072

--- Comment #1 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2012-04-24 13:59:10 UTC ---
On Sun, 22 Apr 2012, manu at gcc dot gnu.org wrote:

> The infrastructure to detect whether options have been set explicitly seems to
> be there, but it is not clear how to use it to fix the above problem.

My notion is that the _set information should move from being a boolean to 
recording the "distance" of the option that set some field from that field 
(it might be set by an option that directly corresponds to the field, or 
by one indirectly implying it, or a default if no relevant option is given 
at all).  Distance is in the sense of appendix 1 of 
<http://gcc.gnu.org/ml/gcc/2010-01/msg00063.html>.

This is explicitly not a detailed design; anyone implementing it would 
need to flesh out the details.