Re: Platform-specific symbols in cus-start.el

[Eli Zaretskii <eliz@gnu.org>]

> Cc: emacs-devel@gnu.org
> From: David Reitter <david.reitter@gmail.com>
> Date: Sat, 21 Mar 2009 08:53:54 -0400
> 
> Related to this, is the kludge below found in nsterm.m appropriate, or  
> should cus-start be fixed?
> 
> 
>    /* these are unsupported but we need the declarations to avoid whining
>       messages from cus-start.el */
>    DEFVAR_BOOL ("x-use-underline-position-properties",
> 	       &x_use_underline_position_properties,
>       doc: /* NOT SUPPORTED UNDER NS.
> *Non-nil means make use of UNDERLINE_POSITION font properties.
> A value of nil means ignore them.  If you encounter fonts with bogus
> UNDERLINE_POSITION font properties, for example 7x13 on XFree prior
> to 4.1, set this to nil.
> 
> NOTE: Not supported on Mac yet.  */);
>    x_use_underline_position_properties = 0;

We could add an extra `cond' clause where it filters out symbols
native to other platforms, and then you could remove this DEFVAR_BOOL.
But, as Stefan points out, it's probably not worth the hassle to do
that for the sake of a single obscure variable, unless we think users
might be fooled to think that the existence of the variable means the
feature is supported.