Re: type based aliasing again

[Andi Kleen <ak AT muc.de>]

craig@jcb-sc.com writes:

> >What you repeatedly miss is that there are many many more
> >people that use gcc as the "free software install tool" than there are 
> >who actually write programs. 
> 
> What you, and others, repeatedly miss is that GCC is a compiler,
> not a free-software install tool.
> 
> If I wanted to work on a free-software install tool, I'd work on RPM
> or something like that.

Just reading the GCC installation document proves you wrong on this one
(GCC definitely uses itself as a free-software install tool). Lots of
other software does too. For example it is the standard installation
method of GNU software as distributed on ftp.gnu.org.

Just ignoring that common use of the compiler just does not serve the
user base, nor I think the GNU project, well.

> If you think the problem is so bad, then go and fix *it* in all the
> code you think is too "stable and trusted" to be permitted to fail
> due to its own bugs.  Do not make GCC worse by having it paper over
> the problem for any amount of time.  That does a long-term disservice
> to users.  I refuse to participate in pandering to users' short-term
> wants by threatening our ability to meet their long-term *needs*.

Because fixing it often needs major data structure changes (overlap ->
explicit union), which are often just impossible to submit into a
stable code freezed production release mainteance tree. Because of
gcc's lack of anonymous unions in C it usually requires changes to
every user of that possible overlapped data structure, it is not possible
to encapsulate it.

If I tried to tell Jeff to change all users of e.g. tree or rtx in
the stable freezed gcc branch to fix some obscure[1] bug caused by
behaviour change in third party software he would laugh me out of the list.

-Andi

[1] Obscure as in "Joe Programmer never heard of it before"

-- 
This is like TV. I don't like TV.