Re: generalized lvalues -- patch outline

[Ian Lance Taylor <ian@wasabisystems.com>]

"Joseph S. Myers" <joseph@codesourcery.com> writes:

> On Wed, 24 Nov 2004, Eric Botcazou wrote:
> 
> > http://www.kerneltraffic.org/kernel-traffic/kt20041009_276.html#3
> > 
> > <but Willy Tarreau replied, "Tell that to gcc developpers who constantly break 
> > compatibility between versions. I even have userland programs which do not 
> > compile anymore with gcc-3.3 and which I don't even know how to 
> > 'fix' (workaround ?).">
> 
> If 3.3 is the problem version, lvalue casts aren't the issue; they are 
> still present in 3.3.  (The backporting of the deprecation which was put 
> in 3.3.4 is something I would consider dubious: though backporting a 
> deprecation may be tempting and give users more warning, it also might 
> break code that was working with that release series, which really should 
> be avoided within a release series once it has first had a release: 
> upgrading from a.b.c to a.b.c+1 should always be safe even with code using 
> a feature that is going to go away.)

Given that lvalue casts were actually removed after the 3.4 series,
and given that, whether you like it or not, they are in fact widely
used, I think that it was absolutely essential to get the warning into
3.3.4, so that people would have a chance to fix their bug before it
completely breaks.  I certainly agree that the warning should have
been in 3.3.0, or that the removal should have been pushed into 4.1.

Ian