GCC 4.0 [Re: FreeBSD 6 is coming too fast]

[Scott Long]

Miguel Mendez wrote:
> On Mon, 25 Apr 2005 07:42:54 -0600
> Scott Long <scottl at samsco.org> wrote:
> 
> 
>>>According to gcc-4.0 release notes, compilation speed for C++ was
>>>dramatically increased, up to 25% IIRC.  I think 4.0 is good
>>>candidate for merging into HEAD.
> 
> 
>>Is this work that you plan on doing for us?  
> 
> 
> Definitely not for 6.0, and I usually avoid .0 releases on critical
> software, but nonetheless it would interesting setting a tinderbox,
> launch a buildworld process with gcc40 and see where/if it breaks. I
> have a spare k6-2 box I could setup for that task.
> 
> 
>>What about the deprecated language constructs in 4.0?
> 
> 
> According to http://gcc.gnu.org/gcc-4.0/changes.html, some of the
> deprecated constructs are not even valid C, so I see this as an
> opportunity to fix buggy code. 
> 
> 
>>What about the lack of exposure that it's
>>had outside of the FSF and Apple development circles?
> 
> 
> Exactly the reason why testing will be beneficial. The more tested the
> product on FreeBSD the more robust it will be when it's time to get it
> into the tree.
> 
> Cheers,

Well, I'd caution against jumping into GCC 4.0 just because of the
claims of 25% speed improvement.  That's about the single worst reason
to do it.  But if you're interested in moving the technology forward,
I'd happily encourage you.  The changed language constructs are the big
problem (extern struct foo bar[]; is no longer valid) since you not only
need to sweep the FreeBSD tree for them, you also need to sweep the
ports tree.  I have mixed feeling on the value of GCC making sloppy
language extentions available for years and then suddenly revoking them,
and I know others that have been affected by 4.0 aren't terribly happy
either.

Scott