Re: [gentoo-user] Re: Upgrading gcc: both 4.4 and 4.5 needed?

[Willie Wong]

On Thu, Nov 17, 2011 at 07:41:21PM +0000, James wrote:
> > Now, why can't the USE descriptions be like the kernel option
> > descriptions and have something like what Pandu wrote included?
>
> I added this to root's  .bashrc a long time ago:
>
> # USE flag settings hack by Ciaran McCreesh:
> explainuseflag(){ sed -ne "s,^\([^ ]*:\)\?$1 - ,,p" $(portageq
> portdir)/profiles/use.{,local.}desc; }
> alias ef="explainuseflag"
>
>
> Then simply use the alias for a quick check to learn about all the different
> uses of a given flag:
>
> 'ef graphite'
>
> # ef graphite
> Enable support for non-Roman fonts via media-gfx/graphite2
> Enable support for non-Roman fonts via media-gfx/graphite2
> Add support for the framework for loop optimizations based on a polyhedral
> intermediate representation
>
> Then drill down into the a specific package's use flag meaning, using the
> aforementioned 'equery u' delineated by Albert.

You people seem to miss my point. I know perfectly well how to find 
the USE descriptions. It is just that the USE description, in this 
case (as in many others) isn't terribly useful. 

"Add support for the framework for loop optimizations based on a 
polyhedral intermediate representation" means absolutely gibberish to
me.

But if one were to add an additional one or two lines a la Pandu, 
about how it is supposed to make " gcc-4.5.3 use a newer method to 
detect parallelism, thus (potentially) makes programs compiled by gcc 
to have better multithreaded performance" and perhaps even a Kernel 
help page style "It is mostly stable. If unsure, say Yes."

It would be ever so much more helpful for people who would like to
find out what new flags do before deciding whether or not to follow
the default recommended by the devs which are set into the profile.

(I'm not saying this type of hand holding is necessary for all flags:
"enable support for non-Roman fonts via media-gfx/graphite2" is 
perfectly understandable, as are most other flags about features a 
"user" is likely to interact with. But for some of the more "system" 
type flags (see also that python/perl flag business from the recent 
months), I think the USE descriptions can stand some improvement.)

W

-- 
Willie W. Wong                                     wwong@××××××××××××××.edu
Data aequatione quotcunque fluentes quantitae involvente fluxiones invenire 
         et vice versa   ~~~  I. Newton