Re: cc-vars.el

[Stefan Monnier]

> I still don't understand how what I did affected this, but then I
> didn't try to use cc-mode in the bootstrapped result.  However, I
> strongly agree with rms.  I didn't realize cc-mode was doing that, but
> I'm sure it shouldn't.
> 
> I've previously fixed Gnus and W3 to avoid special compilation
> mechanisms like that.  Apart from being probably unsuitable for
> installing in Emacs, they actually hid bugs.  There are typically
> still some compilation warnings if you do portability stuff cleanly,
> but they're not usually excessive.  Changes to the compiler would
> help, e.g. to avoid warnings from
> 
>  (unless (fboundp 'fred)
>    (define fred ...))
> 
> A change for that I once suggested greatly reduced the noise and I
> don't think it's a big issue to re-write a few things to forms such a
> compiler check would be documented to recognize.
> 
> I see a comment in cc-bytecomp implying that compilation is supposed
> to produce byte code that's portable between Emacs and XEmacs, but
> that's a lost cause.  They are (now) basically incompatible,
> e.g. XEmacs byte code can crash Emacs if you force it to be loaded.
> This means that the compiler can reasonably eliminate code conditional
> on `(featurep 'xemacs)', for instance, reducing spurious warnings
> again and perhaps improving efficiency in a few cases.
> 
> I also think it's unwise to try to support ancient versions of
> (X)Emacs.  That just makes life difficult and takes resources that
> could be put into improvements for current versions, especially taking
> advantage of new features.
> 
> Sorry if that sounds like just a gripe, but it's from a fair amount of
> experience. :-/

(with-aol-mode Me too!)


        Stefan